CA1284403C - Method of manufacturing a bonded particulate article by reacting a hydrolyzed amylaceous product and a heterocyclic compound - Google Patents
Method of manufacturing a bonded particulate article by reacting a hydrolyzed amylaceous product and a heterocyclic compoundInfo
- Publication number
- CA1284403C CA1284403C CA000522027A CA522027A CA1284403C CA 1284403 C CA1284403 C CA 1284403C CA 000522027 A CA000522027 A CA 000522027A CA 522027 A CA522027 A CA 522027A CA 1284403 C CA1284403 C CA 1284403C
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- Canada
- Prior art keywords
- acid
- mixture
- hydrolyzed
- amylaceous
- article
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
- C08B31/00—Preparation of derivatives of starch
- C08B31/003—Crosslinking of starch
- C08B31/006—Crosslinking of derivatives of starch
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
- B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
- B22C1/20—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents
- B22C1/22—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents of resins or rosins
- B22C1/2233—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents of resins or rosins obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
- B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
- B22C1/20—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents
- B22C1/26—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents of carbohydrates; of distillation residues therefrom
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L97/00—Compositions of lignin-containing materials
- C08L97/02—Lignocellulosic material, e.g. wood, straw or bagasse
Abstract
METHOD OF MANUFACTURING A BONDED PARTICULATE
ARTICULE BY REACTING A HYDROLYZED AMYLACEOUS
PRODUCT AND A HETEROCYCLIC COMPOUND
ABSTRACT
Disclosed herein is a method of manufacturing a bonded particulate article by admixing particulate material with a binder system, the binder system being formed by admixing a polyol comprising a water soluble amylaceous hydrolyzate with a heterocyclic compound comprising the reaction product of glyoxal, urea, and formaldehyde, alone, or in further combination with ethylene glycol, with a solvent, and with an acid effective to control the rate of cross-linking between said polyol and said heterocyclic compound; forming the admixture in a shape and curing the shape to a bonded article.
ARTICULE BY REACTING A HYDROLYZED AMYLACEOUS
PRODUCT AND A HETEROCYCLIC COMPOUND
ABSTRACT
Disclosed herein is a method of manufacturing a bonded particulate article by admixing particulate material with a binder system, the binder system being formed by admixing a polyol comprising a water soluble amylaceous hydrolyzate with a heterocyclic compound comprising the reaction product of glyoxal, urea, and formaldehyde, alone, or in further combination with ethylene glycol, with a solvent, and with an acid effective to control the rate of cross-linking between said polyol and said heterocyclic compound; forming the admixture in a shape and curing the shape to a bonded article.
Description
\
` l~B4403 30,145 MET~OD OF MANUFACTURING A BONDED PARTICULATE
10A2TIC~E BY REACTING A ~YDROLYZED AMYLACEOUS
PRODUCT AND A HETE20CYCLIC COMPO~D
20FIE~D OP THE I~VE~TION
Thi-~ invention relates to a method of manu-facturing a bonded particulate article by admixing a curable binder with particulate material. More par-25 ticularly, this invention relates to composition of a particulate material such as sand or cellulose fiber, with a binder system formed from a polyol comprising a hydrolyzed, gelatinized, y laceous product, a reaction - product of glyosal, urea and formaldehyde, alone, or in 30 further combination with ethylene glycol, a solvent, and an acid catalyst in an amount sufficient to allow the cro~linking reaction between the compounds to proceed.
Articles produced by the procedure have utility as foundry cores and molds and in the production of pressed 35 fiber board.
.
i28~403 BAC~GROUND OF T~E INVENTION
It has long been the practice in both the tex-tile and paper industries to apply starch solutions to S the fibers or various purposes. The ultimate properties of such products have beën improved by crosslinking the starch with polyfunctional compounds, such as glyoxal, and the like. With the advent of heat-hardenable resins such as urea and melamine resins, it became desira~le to 10 mix such resins with the starch to obtain an even more durable finish. Ultimately, heterocyclic reaction pro-ducts of ~i) alpha,beta dicarbonyl compounds, (ii) urea, thiourea or guanidine and (iii) an aldehyde, e.g., for~aldehyde, assumed an important position in the art lS of textile finishing. In Richardson, U.S. 2,661,312, ~or cxample, a stable, curable finish for textlles com-prises 1,3-bls-(hydroxymethyl)-2-~midazoline, starch and tartaric acid. The heterocyclic compound is made, for example, by reacting ethyleneurea with formaldehyde and 20 ha~ two nitrogen-bonded methylol groups which are capa~le of cross-linking the starch, when heated, the rate of cross-linking being promoted by the presence of tartaric acid. I portant state-of-the-art textile finishes also have evolved from such technology. In v. Reibnitz, ~.S.
2S 2,764,573, condensation products of glyoxal and ureas, thioureas or guanidines (glyosal monoureins) are modified by reaction with a}dehydes, e.g., formaldehyde, or aldehydes and an alcohol, and there are produced the corresponding N-substituted alkylol or alkoxyalkyl sub-30 stitutents. The resins are shown to cure, especiallyafter t~e addition of acid hardening catalysts, to waterproof and elastic films. It has subseguently been discovered and is known in the art that the glyoxal monourein and aldehyde condensation products are of 35 great i~ortance when used to treat textiles. In .
~28~03 .
Gagliardi et al, U.S. 3,209,010, it is disclosed that such materials, especially when furthes substituted on the 4- and 5-positions by ether, ester, carbamoyl groups, and the liXe, provide chlorine-resistant finishes on 5 testiles.
The cros~linking of polyhydro~yl compounds, particularly polysaccharides like starch, with multi-functional reagents reactive with hydroxyl groups i5 known outside of the testile field, such as in the 10 manufacture of papcr board from wood and other fibers and foundry molds from sand.
Poundry cores and molds present unique problems.
These are used in making metal castings and are normally prepared from a composition including sand or other re-15 fractory matcrial and a curable or polymerizable bindercoated OA the refractory particles. The purpoJe of this binder coating is to permit the mixture to be hardened aftcr it is first shaped or molded into a desired form.
Shaping o the compo~ition, which usually compr~ses a 20 major amount of sand and a minor amount of binder, is accomplished through ramming, blowing, or otherwise in-troducing the mi~ture into a pattern or core box to thereby ass~ the shape defined by the adjacent sur-face~ of the pattern. Then, by using a catalyst or 25 polymerization accelerator introduced before or after the sand mi~ has been introduced into the pattern, and/or by u~ing he~t, the binder i~ caused to cure, thereby converting the shaped foundry mix into a hard, solsd foundry cor-. Thi5 curing is usually acco~plished 30 either in the orig~al core box, in a gassing chamber, or in a holding pattern. Commonly used binders include such material~ a8 phenolic re~in~, urea-formaldehyde resins, furfural alcohol modified urea-formaldehye resins, furan resins, drying oils and urethane oil3.
Generally ~peaking, two basic techniques exist ~284403 _ 4 in the art for effecting a cure once the sand-binder mixture is shaped. The first of these techniques, the elevated temperature method, involves the use of heat-curable re~in syste~ wherein heat is used to effect hardening of the binder. The second technique is known in the art as the 'no bal~e" or ~cold-setting~ process.
As its name implies, the latter process is carried out at room temperature or slightly above, i.e., 5-50C.
and more often between 15-35C.
Each of these systems has its own set of limi-tations which are well known to those active in the field. Some materials are very energy intensive; some pose significant ha~dling and environmental problems;
some have limited utility because gas evolution from the lS binder during ~etal pouring creates surface defects in the finished l-etal article; and, if the cores are to be baked, green strength additlves mu~t be used 80 that the cores ha~e sufficient strength to be put into and through an oven.
In Cummisford et al., ~.S. 4,013,629; 4,089,691;
4,098,615; and 4,098,859, are disclosed the use of the catalyzed glyosal saccharide systel- in foundry sand core~, cellulose press formed products, adhesives, coat-ing biQders and in many other areas. In Cummisford et 2S al., U.S. 4,158,57~ a water soluble hydrolyzed gelatin-ized amylaceous material is disclosed to be superior to native, conventional cereals as the polyol component in an acidic glyosal binder system. The developments in these patents overc~e many proble~s by controlling the 30 amounts of reactants and catalyst and by selecting the saccharide fra~ the wide range of l-aterials available.
In practice, however, the ultimate products are somewhat deficient in hydrol~tic stability, which limits the use of these binder systems to foundries in which the tempera-35 ture and humidity can be controlled.
`` ~284403 ~ urther representative of the state of the artare Nishikawa et al, U.S. 4,482,654 who coat foundry sand grains with a binder comprised o~ methylolmelamine or alkylated methylolmelamine and a water soluble polyol, S e.g., hydroxymethyl cellulose. Sand molds having a water soluble binder containing sucrose, urea, methylol-melamine or alkylated derivatives and an acidic cross-linking catalyst are disclosed in Japanese Patent Publication 59,185,542, October 22, 1984, Chem. Abs. Vol 10 102:99473r (1985); binders for molding sand consisting of methylolmelamine precondensed with a saccharide are disclosed in erench Patent Publication, April 11, 1980 Chem. Abs. Vol 96:108797m (1982); and glucose mixed with methylated methylolmelamine and used as a binder for 15 foundry sand is described in Japanese Patent Publication 57,124,5~2, August 3, 1982; CS~. Abs. Vol. 98:7323q ~19B3). All such systems show malnly hydrolytic stability problems com~on to the starc~glyoxal system ~entioned above and there still exist~ the need for improved ~0 binder resins.
It has now been discovered, and is the subject of this invention, that binders prepared from hydrolyzed, gelatinized al-ylaceous materials and the condensation products of glyoxal, formaldehyde, urea, and, optionally, 25 ethylene glycol, have remarkably beneficial properties, especially resistance to deterioration by ambient moisture. It is important, especially when using such binders with nonalkaline sands, to include an acid crosslinking catalyst in the composition.
SUMMARY OF T~E INVENTION
According to the present invention there is pcovided a curable composition adapted to produce a 35 shaped bonded particulate article, said composition lZ8~
comprising (i) a particulate material; and, as a binder therefore, (ii) a polyol comprising a hydrolyzed, gela-S tinized a~ylaceou~ material;
(iii) a crosslinker for said polyol (ii) comprising the reaction product of glyoxal, urea and formaldehyde, alone, or in further combination with ethylene glycol; and (iv) an acid catalyst; and tv) a solvent for the binder.
Also contemplated is a method o~ manufacturing a bonded particulate article co~prising the steps of ~ i) admixing particulate material with a bin-15 der syste~, the binder system being formed by admixing apolyol co-prising a hydrolyzed, gelatinized amylaceous material, a cro~sl~nker for sa~d polyol (ii) comprising the reaction product of glyoxal, urea and formaldehyde, alone, or in further combination with ethylene glycol, a 20 sol~ent, and an acid;
(ii) forming the admixture into a shape; and (iii) curing to produce the bonded article.
In preferred features, the crosslinker will be of the formulae:
11 ~ C~20H 8 ~ CE120CE12C~201~
: H0 - C - N80-C N ~
/ C ~ O o~ l /C - O
H0 - C ~ ~0-C N
30 8 \ C82H H C820C~2C8208 or a mixture of the foregoing compounds.
Also contemplated is a cold-cast procedure comprising the steps of (i) admixing a particulate material with a ~284403 binder system wherein the latter is formed by admixing a hydro-lyzed, gelatinized amylaceous material with a crosslinker as de-fined above, a solvent and an acid;
~ii) forming the article in a mold;
(iii) removing the article from the mold, and (iv) desolventizing the article.
In a preferred feature the present invention contem-plates a method of manufacturing a foundry core comprising mixing sand and a heat-accelerated curable binder system wherein the binder system is produced by the following steps, the percentages being based on the weight of the sand:
(a) crosslinking 1-3% of hydrolyzed, gelatinized amylaceous material with 0.1-3% of a crosslinker defined by the above formulae ln about 50% aqueous solution; and (b) controlling the rate of reaction by the use of 0.01-1.0% of an acid as a catalyst, said mixture also comprising 0-10%
clay, 0-10% silica flour, 0-10% iron oxide, and 0-2% of a mold release material selected from the group comprising paraffins, other wax, wax emulsion, asphalt emulsion, and wax-asphalt emul-sion.
In a preferred embodiment of the curable composition ofthe invention, particulate matter (i) comprises 80%-99% by weight and the binder comprises from 1%-20% by weight. The amount of polyol (ii) in the binder comprises 20%-55%. The amount of cross-linker (iii) in the binder comprises 3%-60%. The amount of acid (iv) in the binder comprises 0.2%-10% and the amount of solvent in the binder comprises 15%-85%, all percentages being by weight.
., , .~ ~284~
- _ 7a_ 61109-7496 In a further preferred embodiment the amylaceous mate-rial or polyol is the product of a process comprising:
(a~ hydrolyzing a material selected from corn flour, corn meal, corn grits, corn starch, sorghum flour, sorghum meal, sorghum grits, wheat flour, wheat starch or a mixture of any of the foregoing at moistures between 5% and 12% by weight of the humidified material using between 0.1 and 2% by weight acid;
(b) adjusting the pH of the acid hydrolyzed amylaceous mate-rial to between 3 and 6 obtained on a 10% solids water slurry;
(c) gelatinizing the pH adjusted acid hydrolyzed amylaceous material at moisture levels between 15 and 40% and at temperatures of between 212F and 400F;
(d) removing water from the gelatinized product; and (e) comminuting the dried amylaceous mass to a flow.
When preparing a shaped article, in the steps before forming the mixture into a shape, the mixture is preferably within the limits of 15-85% water, 20-55% amylaceous material, 3-60% of heterocyclic compound (crosslinker) and 0.2-10% of an acid.
The invention also provides a method of manufacturing a resinlike material suitable for formed articles with a binder pro-duced by the following steps:
(a) crosslinking a hydrolyzed gelatinized amylaceou~ material with a heterocyclic compound as defined above or a mixture of such compounds in water;
(b) controlling the rate of the crosslinking reaction between the hydrolyzed gelatinized amylaceous material and the hetercyclic , ~
. . .
~ i284403 - 7b- 61109-7496 compound by the use of an acid salt, the method including the steps of;
(c) dissolving or dispersing the acid hydrolyzed gelatinized amylaceous material and the heterocyclic compound in water; and (d) causing the mixture to react by the application of heat.
DETAILED DESCRIPTION OF THE INVENTION
The saccharide-containing material, used as a polyol in this invention is a hydrolyzed-gelatinized amylaceous material.
This material which is disclosed and claimed in the above-mentioned Cummisford Patent, U.S. 4,158,574, has alkaline viscos-ities which are in the range of 10 to 20 seconds using a 1.3 g sample and 15 to 100 seconds using a 5.2 g sample and having cold water solub~e~ of between 50% and 98%. The alkaline viscosity (AV) i~ an approximate, but useful, measure of molecular weight.
It can be obtained by dispersing the ., ' ~. ', ~ 1284403 sample, 1.3 or 5.2 g. in 50 ml of lN xoa. A micro bowl Waring Blendor is suitable for preparing the dispersions.
~he dispersion is allowed to stand 1 minute for de-aira-tion and a 10 cc. aliquot is pipetted into a ~200 Cannon S Penske viscometer immersed in a 40C. water bath. The sample is moved into the ready position in the viscometer and held there for a time sufficient to assure tempera-ture equilibrium of the sample and bath. A total elapsed time of 12 minutes is used, including the one minute of 10 mixing and the 1 minute of de-airation. The time of the sample to flow bet~een the measured marks on the visco-meter is read and recorded as the Alkaline Viscosity at 1.3 or 5.2 g. Cold water solubles (CSW) are determined by a test to be described later.
The amylaceous material is produced by: acid hydroly3is at moistures between 5~ and 12S, a~ i8 ba8ig, using between 0.1~ and 2% acid anhydrous basis; neutral-~zation of the acid hydrolyzed amylaceous material to between p~ 3 and 6 ootained on a 10~ solids water slurry;
20 gelatinization of the neutralized acid hydrolyzed amyla-ceous material at moisture levels between 15% and 40%
and at temperatures of between 212- and 400F.; removal of water from the gelatinized product by allowing re-sidual heat to flash off water and by subjecting it to 2S the action of a drying medium such as air or heat; and/
or commuting the a~ylaceous mass to pellets or flakes;
and comminuting the dried amylaceous mass to a flour.
Further details are provided by the said patent, and a wor~ing procedure is included hereinafter.
The hydrolyzed amylaceous material can be used alone, or in further combination with up to sa~ by weight of a conventional polyol. Such polyols are those which react rapidly with glyoxal monourein-aldehyde condensates and are typically saccharides, such as 35 sugars, starch, starch hydrolyzates, gums, dextrins, and , .
-~284fl~03 g the like, so long as these are water-hydratable or soluble and have available reactive groups for cross-linking. Proteins, especially glyco proteins, also can be used, again with the restriction that these are S reactivé with glyoxal monourein-aldehyde condensates, and, illustratively, these will include collagen protein, and the like. Illustratively, the additional saccharide-containing ~aterial to be used with the hydrolyzed gelatiniz~d a~ylaceous material can be selected from 10 sucrose, ualtose, corn syrup, corn syrup solids, glycoproteins or mixtures of any of the foregoing.
The crosslinking components used in the present invention are reaction products of glyoxal, formaldehyde, urea, alone, or in further combination with ethylene 15 glycol. They are made, in general, by reacting aqueous solution~ of glyoxal and of formaldehyde with urea at a p8 near ncutral or Jl~ghtly on the acid side, e.g., 5 to 7.5, and at a ~u$table temperature, e.g., 40-70C. The mole ratio of reactants generally is one glyoxal: two 20 formaldehyde:one of urea and, if used, : two of ethylene glycol. The progress of the reaction can be followed by a number of methods, but it i~ convenient to measure reduction ~n free formaldehyde content--when this falls below about 1~, the reaction is dee~ed complete. Usually 25 a few hours, e.g., 2-3 hours, is sufficient. Generally a small a~ount of acid, e.g., citric acid or hydrochloric acid, or base, e.g., NaOH, is addec at the end of the reaction to adjust the pa to a~out 3-5. The product is obtained as aA aqueou~ solution, which can be adjusted 30 to a solids content in a covenient range, e.g., 40-50~, for used in the present invention.
~284403 The crosslinkers are compounds of the formulae:
H / C~20 HO - C N
S ¦ / C ~ O and HO - C N
\C~20E~
~ . ~C~20CE~2CE120H
HO - C N
/C - O
~O - C N
C~20CE~2CH20 lS
~ ixtures o~ the coopounds can be used without departing from the scopc of t~e invention. Also, com-positions comprising the dimethylol compound and ethylene glycol in water and optionally partially neutralized 20 citric acid are suitablc.
The preparation of such compounds is accom-plished by means known to those skilled in this art.
Suitable procedures are set forth hereinafter.
The catalyst or accelerator employed is an 2S acidic type catalyst and may be a free inorganic or organic acid, acid salt, alkanolamine salt and the like of the type well known to those in the art. See, for example, Beachem, U.S. 3,304,312. The concent~ation of cataly~t employed can range from about 0.1 to about 25%
30 or higher, based on the weight of the ~olids in the binder, depending on the particular catalyst type employed. Thus, for exa-ple, from between about 0.1%
and about 10~ of a free acid such as sulfuric, hydrochloric, acetic, phosphoric, tartaric, o~alic or 35 the like may be used, while i~ the case of a~onium ~, ::
; ~ ` '`
~;~849~03 chloride amounts of from between 0.5 and 10% can be used. In the case of amine salts, such as alkanolamine galtsr e.g., diethanolamine hydrochloride from about 1 to about 10% are most useful, while with respect to 5 salts such as magne~ium chloride amounts of between about 0.5 and 25% have been successfully employed. In addition to magnesiu~ chloride, zinc nitrate, aluminum chloride and other known conventional metal salts are normally employed in amounts which can correspond to 10 between 0.5 and 25% based on the weight of the solids in the binder composition. Preferred for the invention are LeYis acid salts. These denote a family of metal salts which are electron pair acceptors. They comprise halides, nitrates, sulfates, mixed halides/hydrosides, and the 15 like, of metals such as iron, tin, phosphorus, arsenic, antimony, bismuth, zinc, aluminum, magnesium, boron and the like. Typical cx ples of Lewis acid salts are 3~ SnC14~ PF5~ AgPs, SbPs and BiC13, a8 well as Zn(l~3)2' MgC12~ Mg(N3)2~ A12(So4)3~ x Y
` l~B4403 30,145 MET~OD OF MANUFACTURING A BONDED PARTICULATE
10A2TIC~E BY REACTING A ~YDROLYZED AMYLACEOUS
PRODUCT AND A HETE20CYCLIC COMPO~D
20FIE~D OP THE I~VE~TION
Thi-~ invention relates to a method of manu-facturing a bonded particulate article by admixing a curable binder with particulate material. More par-25 ticularly, this invention relates to composition of a particulate material such as sand or cellulose fiber, with a binder system formed from a polyol comprising a hydrolyzed, gelatinized, y laceous product, a reaction - product of glyosal, urea and formaldehyde, alone, or in 30 further combination with ethylene glycol, a solvent, and an acid catalyst in an amount sufficient to allow the cro~linking reaction between the compounds to proceed.
Articles produced by the procedure have utility as foundry cores and molds and in the production of pressed 35 fiber board.
.
i28~403 BAC~GROUND OF T~E INVENTION
It has long been the practice in both the tex-tile and paper industries to apply starch solutions to S the fibers or various purposes. The ultimate properties of such products have beën improved by crosslinking the starch with polyfunctional compounds, such as glyoxal, and the like. With the advent of heat-hardenable resins such as urea and melamine resins, it became desira~le to 10 mix such resins with the starch to obtain an even more durable finish. Ultimately, heterocyclic reaction pro-ducts of ~i) alpha,beta dicarbonyl compounds, (ii) urea, thiourea or guanidine and (iii) an aldehyde, e.g., for~aldehyde, assumed an important position in the art lS of textile finishing. In Richardson, U.S. 2,661,312, ~or cxample, a stable, curable finish for textlles com-prises 1,3-bls-(hydroxymethyl)-2-~midazoline, starch and tartaric acid. The heterocyclic compound is made, for example, by reacting ethyleneurea with formaldehyde and 20 ha~ two nitrogen-bonded methylol groups which are capa~le of cross-linking the starch, when heated, the rate of cross-linking being promoted by the presence of tartaric acid. I portant state-of-the-art textile finishes also have evolved from such technology. In v. Reibnitz, ~.S.
2S 2,764,573, condensation products of glyoxal and ureas, thioureas or guanidines (glyosal monoureins) are modified by reaction with a}dehydes, e.g., formaldehyde, or aldehydes and an alcohol, and there are produced the corresponding N-substituted alkylol or alkoxyalkyl sub-30 stitutents. The resins are shown to cure, especiallyafter t~e addition of acid hardening catalysts, to waterproof and elastic films. It has subseguently been discovered and is known in the art that the glyoxal monourein and aldehyde condensation products are of 35 great i~ortance when used to treat textiles. In .
~28~03 .
Gagliardi et al, U.S. 3,209,010, it is disclosed that such materials, especially when furthes substituted on the 4- and 5-positions by ether, ester, carbamoyl groups, and the liXe, provide chlorine-resistant finishes on 5 testiles.
The cros~linking of polyhydro~yl compounds, particularly polysaccharides like starch, with multi-functional reagents reactive with hydroxyl groups i5 known outside of the testile field, such as in the 10 manufacture of papcr board from wood and other fibers and foundry molds from sand.
Poundry cores and molds present unique problems.
These are used in making metal castings and are normally prepared from a composition including sand or other re-15 fractory matcrial and a curable or polymerizable bindercoated OA the refractory particles. The purpoJe of this binder coating is to permit the mixture to be hardened aftcr it is first shaped or molded into a desired form.
Shaping o the compo~ition, which usually compr~ses a 20 major amount of sand and a minor amount of binder, is accomplished through ramming, blowing, or otherwise in-troducing the mi~ture into a pattern or core box to thereby ass~ the shape defined by the adjacent sur-face~ of the pattern. Then, by using a catalyst or 25 polymerization accelerator introduced before or after the sand mi~ has been introduced into the pattern, and/or by u~ing he~t, the binder i~ caused to cure, thereby converting the shaped foundry mix into a hard, solsd foundry cor-. Thi5 curing is usually acco~plished 30 either in the orig~al core box, in a gassing chamber, or in a holding pattern. Commonly used binders include such material~ a8 phenolic re~in~, urea-formaldehyde resins, furfural alcohol modified urea-formaldehye resins, furan resins, drying oils and urethane oil3.
Generally ~peaking, two basic techniques exist ~284403 _ 4 in the art for effecting a cure once the sand-binder mixture is shaped. The first of these techniques, the elevated temperature method, involves the use of heat-curable re~in syste~ wherein heat is used to effect hardening of the binder. The second technique is known in the art as the 'no bal~e" or ~cold-setting~ process.
As its name implies, the latter process is carried out at room temperature or slightly above, i.e., 5-50C.
and more often between 15-35C.
Each of these systems has its own set of limi-tations which are well known to those active in the field. Some materials are very energy intensive; some pose significant ha~dling and environmental problems;
some have limited utility because gas evolution from the lS binder during ~etal pouring creates surface defects in the finished l-etal article; and, if the cores are to be baked, green strength additlves mu~t be used 80 that the cores ha~e sufficient strength to be put into and through an oven.
In Cummisford et al., ~.S. 4,013,629; 4,089,691;
4,098,615; and 4,098,859, are disclosed the use of the catalyzed glyosal saccharide systel- in foundry sand core~, cellulose press formed products, adhesives, coat-ing biQders and in many other areas. In Cummisford et 2S al., U.S. 4,158,57~ a water soluble hydrolyzed gelatin-ized amylaceous material is disclosed to be superior to native, conventional cereals as the polyol component in an acidic glyosal binder system. The developments in these patents overc~e many proble~s by controlling the 30 amounts of reactants and catalyst and by selecting the saccharide fra~ the wide range of l-aterials available.
In practice, however, the ultimate products are somewhat deficient in hydrol~tic stability, which limits the use of these binder systems to foundries in which the tempera-35 ture and humidity can be controlled.
`` ~284403 ~ urther representative of the state of the artare Nishikawa et al, U.S. 4,482,654 who coat foundry sand grains with a binder comprised o~ methylolmelamine or alkylated methylolmelamine and a water soluble polyol, S e.g., hydroxymethyl cellulose. Sand molds having a water soluble binder containing sucrose, urea, methylol-melamine or alkylated derivatives and an acidic cross-linking catalyst are disclosed in Japanese Patent Publication 59,185,542, October 22, 1984, Chem. Abs. Vol 10 102:99473r (1985); binders for molding sand consisting of methylolmelamine precondensed with a saccharide are disclosed in erench Patent Publication, April 11, 1980 Chem. Abs. Vol 96:108797m (1982); and glucose mixed with methylated methylolmelamine and used as a binder for 15 foundry sand is described in Japanese Patent Publication 57,124,5~2, August 3, 1982; CS~. Abs. Vol. 98:7323q ~19B3). All such systems show malnly hydrolytic stability problems com~on to the starc~glyoxal system ~entioned above and there still exist~ the need for improved ~0 binder resins.
It has now been discovered, and is the subject of this invention, that binders prepared from hydrolyzed, gelatinized al-ylaceous materials and the condensation products of glyoxal, formaldehyde, urea, and, optionally, 25 ethylene glycol, have remarkably beneficial properties, especially resistance to deterioration by ambient moisture. It is important, especially when using such binders with nonalkaline sands, to include an acid crosslinking catalyst in the composition.
SUMMARY OF T~E INVENTION
According to the present invention there is pcovided a curable composition adapted to produce a 35 shaped bonded particulate article, said composition lZ8~
comprising (i) a particulate material; and, as a binder therefore, (ii) a polyol comprising a hydrolyzed, gela-S tinized a~ylaceou~ material;
(iii) a crosslinker for said polyol (ii) comprising the reaction product of glyoxal, urea and formaldehyde, alone, or in further combination with ethylene glycol; and (iv) an acid catalyst; and tv) a solvent for the binder.
Also contemplated is a method o~ manufacturing a bonded particulate article co~prising the steps of ~ i) admixing particulate material with a bin-15 der syste~, the binder system being formed by admixing apolyol co-prising a hydrolyzed, gelatinized amylaceous material, a cro~sl~nker for sa~d polyol (ii) comprising the reaction product of glyoxal, urea and formaldehyde, alone, or in further combination with ethylene glycol, a 20 sol~ent, and an acid;
(ii) forming the admixture into a shape; and (iii) curing to produce the bonded article.
In preferred features, the crosslinker will be of the formulae:
11 ~ C~20H 8 ~ CE120CE12C~201~
: H0 - C - N80-C N ~
/ C ~ O o~ l /C - O
H0 - C ~ ~0-C N
30 8 \ C82H H C820C~2C8208 or a mixture of the foregoing compounds.
Also contemplated is a cold-cast procedure comprising the steps of (i) admixing a particulate material with a ~284403 binder system wherein the latter is formed by admixing a hydro-lyzed, gelatinized amylaceous material with a crosslinker as de-fined above, a solvent and an acid;
~ii) forming the article in a mold;
(iii) removing the article from the mold, and (iv) desolventizing the article.
In a preferred feature the present invention contem-plates a method of manufacturing a foundry core comprising mixing sand and a heat-accelerated curable binder system wherein the binder system is produced by the following steps, the percentages being based on the weight of the sand:
(a) crosslinking 1-3% of hydrolyzed, gelatinized amylaceous material with 0.1-3% of a crosslinker defined by the above formulae ln about 50% aqueous solution; and (b) controlling the rate of reaction by the use of 0.01-1.0% of an acid as a catalyst, said mixture also comprising 0-10%
clay, 0-10% silica flour, 0-10% iron oxide, and 0-2% of a mold release material selected from the group comprising paraffins, other wax, wax emulsion, asphalt emulsion, and wax-asphalt emul-sion.
In a preferred embodiment of the curable composition ofthe invention, particulate matter (i) comprises 80%-99% by weight and the binder comprises from 1%-20% by weight. The amount of polyol (ii) in the binder comprises 20%-55%. The amount of cross-linker (iii) in the binder comprises 3%-60%. The amount of acid (iv) in the binder comprises 0.2%-10% and the amount of solvent in the binder comprises 15%-85%, all percentages being by weight.
., , .~ ~284~
- _ 7a_ 61109-7496 In a further preferred embodiment the amylaceous mate-rial or polyol is the product of a process comprising:
(a~ hydrolyzing a material selected from corn flour, corn meal, corn grits, corn starch, sorghum flour, sorghum meal, sorghum grits, wheat flour, wheat starch or a mixture of any of the foregoing at moistures between 5% and 12% by weight of the humidified material using between 0.1 and 2% by weight acid;
(b) adjusting the pH of the acid hydrolyzed amylaceous mate-rial to between 3 and 6 obtained on a 10% solids water slurry;
(c) gelatinizing the pH adjusted acid hydrolyzed amylaceous material at moisture levels between 15 and 40% and at temperatures of between 212F and 400F;
(d) removing water from the gelatinized product; and (e) comminuting the dried amylaceous mass to a flow.
When preparing a shaped article, in the steps before forming the mixture into a shape, the mixture is preferably within the limits of 15-85% water, 20-55% amylaceous material, 3-60% of heterocyclic compound (crosslinker) and 0.2-10% of an acid.
The invention also provides a method of manufacturing a resinlike material suitable for formed articles with a binder pro-duced by the following steps:
(a) crosslinking a hydrolyzed gelatinized amylaceou~ material with a heterocyclic compound as defined above or a mixture of such compounds in water;
(b) controlling the rate of the crosslinking reaction between the hydrolyzed gelatinized amylaceous material and the hetercyclic , ~
. . .
~ i284403 - 7b- 61109-7496 compound by the use of an acid salt, the method including the steps of;
(c) dissolving or dispersing the acid hydrolyzed gelatinized amylaceous material and the heterocyclic compound in water; and (d) causing the mixture to react by the application of heat.
DETAILED DESCRIPTION OF THE INVENTION
The saccharide-containing material, used as a polyol in this invention is a hydrolyzed-gelatinized amylaceous material.
This material which is disclosed and claimed in the above-mentioned Cummisford Patent, U.S. 4,158,574, has alkaline viscos-ities which are in the range of 10 to 20 seconds using a 1.3 g sample and 15 to 100 seconds using a 5.2 g sample and having cold water solub~e~ of between 50% and 98%. The alkaline viscosity (AV) i~ an approximate, but useful, measure of molecular weight.
It can be obtained by dispersing the ., ' ~. ', ~ 1284403 sample, 1.3 or 5.2 g. in 50 ml of lN xoa. A micro bowl Waring Blendor is suitable for preparing the dispersions.
~he dispersion is allowed to stand 1 minute for de-aira-tion and a 10 cc. aliquot is pipetted into a ~200 Cannon S Penske viscometer immersed in a 40C. water bath. The sample is moved into the ready position in the viscometer and held there for a time sufficient to assure tempera-ture equilibrium of the sample and bath. A total elapsed time of 12 minutes is used, including the one minute of 10 mixing and the 1 minute of de-airation. The time of the sample to flow bet~een the measured marks on the visco-meter is read and recorded as the Alkaline Viscosity at 1.3 or 5.2 g. Cold water solubles (CSW) are determined by a test to be described later.
The amylaceous material is produced by: acid hydroly3is at moistures between 5~ and 12S, a~ i8 ba8ig, using between 0.1~ and 2% acid anhydrous basis; neutral-~zation of the acid hydrolyzed amylaceous material to between p~ 3 and 6 ootained on a 10~ solids water slurry;
20 gelatinization of the neutralized acid hydrolyzed amyla-ceous material at moisture levels between 15% and 40%
and at temperatures of between 212- and 400F.; removal of water from the gelatinized product by allowing re-sidual heat to flash off water and by subjecting it to 2S the action of a drying medium such as air or heat; and/
or commuting the a~ylaceous mass to pellets or flakes;
and comminuting the dried amylaceous mass to a flour.
Further details are provided by the said patent, and a wor~ing procedure is included hereinafter.
The hydrolyzed amylaceous material can be used alone, or in further combination with up to sa~ by weight of a conventional polyol. Such polyols are those which react rapidly with glyoxal monourein-aldehyde condensates and are typically saccharides, such as 35 sugars, starch, starch hydrolyzates, gums, dextrins, and , .
-~284fl~03 g the like, so long as these are water-hydratable or soluble and have available reactive groups for cross-linking. Proteins, especially glyco proteins, also can be used, again with the restriction that these are S reactivé with glyoxal monourein-aldehyde condensates, and, illustratively, these will include collagen protein, and the like. Illustratively, the additional saccharide-containing ~aterial to be used with the hydrolyzed gelatiniz~d a~ylaceous material can be selected from 10 sucrose, ualtose, corn syrup, corn syrup solids, glycoproteins or mixtures of any of the foregoing.
The crosslinking components used in the present invention are reaction products of glyoxal, formaldehyde, urea, alone, or in further combination with ethylene 15 glycol. They are made, in general, by reacting aqueous solution~ of glyoxal and of formaldehyde with urea at a p8 near ncutral or Jl~ghtly on the acid side, e.g., 5 to 7.5, and at a ~u$table temperature, e.g., 40-70C. The mole ratio of reactants generally is one glyoxal: two 20 formaldehyde:one of urea and, if used, : two of ethylene glycol. The progress of the reaction can be followed by a number of methods, but it i~ convenient to measure reduction ~n free formaldehyde content--when this falls below about 1~, the reaction is dee~ed complete. Usually 25 a few hours, e.g., 2-3 hours, is sufficient. Generally a small a~ount of acid, e.g., citric acid or hydrochloric acid, or base, e.g., NaOH, is addec at the end of the reaction to adjust the pa to a~out 3-5. The product is obtained as aA aqueou~ solution, which can be adjusted 30 to a solids content in a covenient range, e.g., 40-50~, for used in the present invention.
~284403 The crosslinkers are compounds of the formulae:
H / C~20 HO - C N
S ¦ / C ~ O and HO - C N
\C~20E~
~ . ~C~20CE~2CE120H
HO - C N
/C - O
~O - C N
C~20CE~2CH20 lS
~ ixtures o~ the coopounds can be used without departing from the scopc of t~e invention. Also, com-positions comprising the dimethylol compound and ethylene glycol in water and optionally partially neutralized 20 citric acid are suitablc.
The preparation of such compounds is accom-plished by means known to those skilled in this art.
Suitable procedures are set forth hereinafter.
The catalyst or accelerator employed is an 2S acidic type catalyst and may be a free inorganic or organic acid, acid salt, alkanolamine salt and the like of the type well known to those in the art. See, for example, Beachem, U.S. 3,304,312. The concent~ation of cataly~t employed can range from about 0.1 to about 25%
30 or higher, based on the weight of the ~olids in the binder, depending on the particular catalyst type employed. Thus, for exa-ple, from between about 0.1%
and about 10~ of a free acid such as sulfuric, hydrochloric, acetic, phosphoric, tartaric, o~alic or 35 the like may be used, while i~ the case of a~onium ~, ::
; ~ ` '`
~;~849~03 chloride amounts of from between 0.5 and 10% can be used. In the case of amine salts, such as alkanolamine galtsr e.g., diethanolamine hydrochloride from about 1 to about 10% are most useful, while with respect to 5 salts such as magne~ium chloride amounts of between about 0.5 and 25% have been successfully employed. In addition to magnesiu~ chloride, zinc nitrate, aluminum chloride and other known conventional metal salts are normally employed in amounts which can correspond to 10 between 0.5 and 25% based on the weight of the solids in the binder composition. Preferred for the invention are LeYis acid salts. These denote a family of metal salts which are electron pair acceptors. They comprise halides, nitrates, sulfates, mixed halides/hydrosides, and the 15 like, of metals such as iron, tin, phosphorus, arsenic, antimony, bismuth, zinc, aluminum, magnesium, boron and the like. Typical cx ples of Lewis acid salts are 3~ SnC14~ PF5~ AgPs, SbPs and BiC13, a8 well as Zn(l~3)2' MgC12~ Mg(N3)2~ A12(So4)3~ x Y
2~ mistures thereof, and the like. Preferred Lewis acid salt catalysts for use herein are zinc nitrate and magnesium nitrate.
In the production of foundry cores, there are a number of different methods for applying heat to the 25 formed cores to bring about a cure of the binder. These include cold forming followed by baking of the cores, forming the cores in heated patterns, sometimes called a hot bo~, and forming the cores in a pattern or box followed by forcing heated air through the core.
This invention can be used in any of the above methods. The advantages of this invention are ~i) the use of aqueous solvents which emit no odors or noxious fu es ~ii) that the binder system presents no air or water pollution hazards, and, especially, ~iii) the 35 hydrolytic stability of the bonded article is very high.
1~:84403 A bonded particulate article manufactured by the method of the present invention may preferably comprise 80~-99% particu-late matter and 1%-20% binder system, with the latter being com-prised of 20%-55% said polyol, said polyol being a saccharide material, 3%-60% of crosslinker, 0.2-10% of an acid and 15-85% of - solvent, by weight. If water is the solvent, part of the content can be contributed by moisture in the sand. Part also can be con-tributed by any solvent in which the crosslinker is contained.
A preferred method of manufacturing a foundry core under the present invention comprises the steps of mixing sand and a heat-accelerated curable binder system wherein the binder system i8 produced by the following steps, weight percentages being based on 100 parts of sand: crosslinking 1%-3% of hydrolyzed, gelatinized matter with 0.1-3% of a crosslinker as above defined in a 25-90%, preferably 40-60%, aqueous solution, controlling the reaction by the use of 0.01%-1%, preferably 0.3-1%, acid as a catalyst using 0%-10% clay, 0%-10% wood flour, 0%-10~ silica flour, 0%-10% iron oxide (as optional fillers), and 0%-3% of a material selected from the group comprising wax, wax emulsion, asphalt emulsion or wax-asphalt emulsion (as optional flow promoters and/or mold releases); and forming the mixture to desired shape and causing it to cure to a hardened state.
Preferred compositions for some processes include a release agent.
This can comprise a mixture of a paraffin solvent alone or including a fatty acid. A useful such composition is a mixture of kerosene and oleic acid in a weight ratio of from about 8:1 to about 1:1. The amount used can vary ~2844~
12a 61109-7496 but preferably is from 0.05 to 2% based on the sand, by weight.
In manufacturing a resinlike material with the present invention the method may include mixing a filler material and a heat-accelerated curable binder system, the binder system having been produced by cross-linking .;
.
, -` ~28~03 a hydrolyzed, gelatinized amylaceous substance with a heterocyclic cros~linker as defined above in the presence of an amount of an acid effective to maintain the reaction at a ~uitable rate during curing. The method of mising 5 can vary, but generally will include the following steps: (i) dissolving or disper~ing the acid, hydrolyzed, gelatinized amylaceous substance and heterocyclic compound in water; and (ii) causing the mixture to react by the application of heat. In one preferred way of operating, 10 prior to application of heat, up to 80% of the weight of the binder sy~tem of fillers, pigments and extenders are dispersed in the ~ystem. Eves re preferred, is to prcmi~ up to 80~ of the weight of the binder syste~ of filler~, pigments and estenders with the a~ylaceous 15 material, then to add the cross linker and the acid in admixture.
Cur~ng o the c~r~ w~ll be at conventional op~rating condition~, e.g., 5-180 ~econds in a hot ~ox, operated at bctween 250-550'P. The core usually will be 20 removed from the form and dried in an oven. Conventional techniques can be used. The core can be post-cured with microwave energy.
If the binder system is used with other fillers to make other ~haped articles, practices entirely conven-25 tional in those arts will be u~ed. Merely by way ofillustration, the crosslinker and the acid can be slurried in warm ~ater with wood fibers. Then hydrolyzed, gela-tinized corn flour can be added and ~lended. Dewatering on a vacuum filter give~ a damp preform which can bc 30 pressed and cured at 230-F for 20 minutes to produce a pressed fiberboard with a hard, glossy surface.
The following procedures are used to prepare materials used in the working examples.
~284~03 PROCEDURE A
A hydrolyzed, gelatinized amylaceous starch is made by the procedure of Example 25 of U.S. 4,158,574.
Eight S00 gm samples of yellow corn flour are blended with 0.2 to 0.4% ~2SO4 and tempered to 18-24%
moisture. After addition of acid and water, the samples are blended for 20 sinutes in a ~obart mixer at low speed. The samples are then processed in a laboratory 10 extruder employing a 220F rear barrel temperature and 280F for the discharge end 1/3 length. The e~truder is run at S0 rpm with a 2:1 compression screw. The extruded samples are cooled to roo~ temperature and ground on a haomermill. The 10~ slurry of the sample gives a p~ of 15 3.5-4.1. The products are then tested for cold water solubles and alkaline viscosities.
A typical product has a cold water solubles (C~S) of 12.8S, an alkaline viscosity of 20.3 seconds (1.3 g. of sample). After extrusion it has a CWS of 20 84.3% and an alkaline viscosity of 13.6 seconds (1.3 g.
sample).
The method for determining alkaline viscosities has been given above. The procedure for the cold water solubles (CWS) is as follows: A 20g. sample is weighed 25 and added to 480 g. of distilled water in a 600 ml.
beaker. A magnetic stirrer is used to disperse the material with stirring carried out for 5 minutes. (If the sample tends to lump when added to the water, addition is made by sifting the sample into the water Yith stirrer 30 running using a tea strainer.) The slurry is allowed to stand for one hour and then mixed again for 2 minutes.
The slurry is filtered using 18.5 cm. fluted paper (Reeve Angel t802 or equivalent). The first few cc's of ~iltrate are discarded. Ten ml. of the filtrate are 35 placed in a weighed aluminum weighing dish and the dish -~284403 and aliquot weighed. The aliquot is driea at 70C in a circulating air oven for 24t2 hours. The dried residue is weighed and the % solubles calculated.
PROCEDURE B (RP-l) A reaction product comprising glyoxal, urea and foemaldehyde is prepared by the following procedure:
A mi~ture of one mole of glyoxal (as a 40%
10 aqueous solution) and 2 moles of focmaldehyde (as a 44%
aqueous solution) is adusted to a p~ of 6.4-6.5 with sodium bicarbonate~ To this is added one mole of urea and the mixture is heated to 60C ~aintaining the p~ at 6.4-6.5 by fregyent additions of sodium ~icarbonate.
15 When the free formaldehyde content by analysis drops to 1~ the reaction mixture i8 cooled, the p~ adjusted to 3.0 with hydrochloric acid and water i8 added to adjust the solid~ content to 44-45~.
The compound has the formula /c~2o~
~0 C N
\C - O
~0 - C - N
~C~20~
PROCEDURE C-l (RP-2) A reaction proauc~ comprising glyoxal, urea, formaldehyde and et~ylene glycol is prepared by the following procedure:
In a reaction vessel, one mole of glyoxal (40.3~ glyoxal, 4.7~ aqueous solution) is mixed with two ~5 moles of fo~maldehyde (50% formalin aqueous solution), -1~8~
one mole of urea and 1.5 moles of ethylene glycol. The pa of the mixture is adjusted by addition of NaOB to a value in the range of 6 to 7 and is maintained in that range while the mixture is reacted at 60C for three 5 hours. Then about 0.5% by weight of citric acid, based on the weight of the finished product, is added to the mixture and the pH is adjusted to 3.0 by the addition of SO4. The temperature of the mixture is maintained at 60C for one hour, then cooled to about 25C and the p~
10 is finally adjusted to about 4.5 to 5.5 by the addition of NaO~ to make the finished product solution (solids content about 40-50% by weight).
The compound has the for~ula ~ ~ C~2OC~2C~2OH
~O-C - N
~C - O
~O-C N
~I C~20CB2C~1201I
PROC~DUR~ C-2 (RP-2) ;
As an alternate to C-l, the following procedure is suitable:
In a reaction vessel, one mole of glyoxal (40.3% glyoxal, 4.7% formaldehyde a~ueous solution) is mixed with two moles of formaldehyde (50% formalin aqueous solution), and one mole of urea. The pH of the misture is adjusted by the addition of NaO~ to a value in the 30 range of 6 to 7 and is maintained at that range while the mixture is reacted at 60C for three hours. Then 1.5 moles of ethylene glycol is added. Then about 0.5% by weight of ctiric acid, based on the weight of the finished product, is added to the mixture and the p~ is adjusted 35 to 3.0 by addition of H2SO4. The temperature of the -~284403 mixture is maintained at 60C for one hour, tben cooled to about 25C and the p~ is finally adjusted to about 4.5 to 5.5 by addition of NaO~ to make the finished product solution (solids content about 40 to 50% by 5 weight).
DESCRIPTION OF TE~E PREFE~RED EMBODIMENTS
The following Examples illustrate the present 10 invention, but are not intended to limit the claims.
The sand mixes in the examples are made in a Simpson Sand Muller. Silica sand and the polysaccharide of Procedure A are dry blended for 30 to 90 seconds.
Water is added and the system blended for two minutes.
15 An aqueous solution of the nitrogenous heterocyclic crosslinker of Procedures B or C and metal salt as specified is then added and ~he system ~s blended for two minute~. $he Standard A~erican Poundry Society l-inch tensile briquets are the~ prepared by hand ramming into 20 the tensile core boxes. The resulting 1~ thick dog-bone shaped cores are baked at 350F for 30 minutes. Tensile strengt~ is measured after 2 hours using a Detroit Testing ~achine Company Model CST testing machine.
2S E~MPLE 1 Based on 100 parts by weight of sand, 2% of amylaceous starch (cereal), 0.5% of the reaction product (RP-l) of glyoxal, urea and formaldehyde (Procedure B) 30 and 0.03% of zinc nitrate and 2.5% of water are mised, molded, cured and tested.
For comparison purposes, ~ixtures omitting the crosslinker and the ~ewis ac}d salt, and omitting the ~ewis acid salt, respectively, are prepared. The results 35 are as follows:
~28~403 Tensile Example %Cereal ~RP-l** %Zn(N03~2 %~2 Strength (psi) lA* 2 0.0 0.0 2.5 56 lB* 2 0.5 0.0 2.5 63 5 1 2 0.5 0.03 2.5 280 * Control ** Based on solids, 44% in water.
The foregoing results demonstrate the advanta-geous results achieved by the three-component binder system of the present invention.
To further demonstrate the advance in the art provided by the present invention, hydrolytic stability 15 tests were carried out. The test cores in the form of dog bone specimens prepared according to ~xample 1 were made and or compari on purposes ~pecimens prepared according to ~xa~ple 2 of ~.8. 4,0g8,615, which employed glyoxal as a crosslinker were made. Tensile strengths 20 were measured two hours after production and then exposure to 80% relative hu~idity at 80F for 16 hours. The for~ulations used and the results obtained are set forth as follows:
Tensile 2S Stren~th (psi) Esam- ~Cross as 80% R~
ple %Cereal linker %Catalvst %~2 made exPosed 1 2.0 0.5 RP-l 0.03 Zn(N03)2 2-5 280 200 lC~ 2.0 0.6 Glyo~al0.5 NaCl 2.8 274 50 The results show that the present invention provides bonded articles with substantial hYdrolytic stability resistance which permits their use in environ-ments, such as foundrys, with high ambient humidities.
.
~L28~a~03 The procedure of Example 1 is repeated. The amounts of RP-l, Zn(N03)2 and ~2 are the same as used in Example 1 and the hydrolyzed cereal is partially replaced in stages with a conventional cereal. The following results are obtained:
Example % Cereal ~ CC~ Tensile Strenqth (psi) 2 1.88 .12 195 3 1.5 .5 103 15 * Acid ~odified corn ~tarch (~rauJe Milling Co. UAmerikor~ brand).
Substitution of conventional cereals for part of the hydrolysed cereal in E~ample 1 results in a lower 20 core tensile strength. However E~amples 2-3 demonstrate that a conve~tional cereal (CC) can successfully be added in place o ~ome o the hydrolyzed amylaceous ~tarch. Other conventional cereals which can be used include wheat flour, rye starch, and the like.
The procedure of Example 1 i~ repeated with the e~ception that the amount of RP-l is increased.
.
.
128~03 ExamDle % Cereal % RP-l Tensile Strenqth (Psi) 4 2 .60 335 5 5 .2 .65 367 6 2 .75 420 It is seen that tensile strength increases with the level of RP-l.
A core is prepared as in the manner of Example 1 except it is prepared in a hot box and is post-cured in 15 a microwave oven for 30 sec. The core tensile strength i~ 334 p~i, demonstrating the beneficial e~fect of using a m~cro~ave oven.
A sand core is preFared as described in Example 1 except that magnesium nitrate is substituted for zinc nitrate and the reaction product from glyoxal, urea, formaldehyde and ethylene glycol ~RP-2, Procedure C-l) 25 is used in place of RP-l. The resulting tensile strength is 207 psi, demonstrating the beneficial effect of this system. If RP-2 made by the process of Procedure C-2 is used, substantially the same results will be obtained.
: 30 -1284~03 If the following composition is made: 16 g. of RP-l and 4 g. of zinc nitrate in 600 ml. of warm water is formed into a slurry with 80 g. of wood fibers.
Twenty g. of acid modified gelatinized corn flour (Procedure A) is then intimately blended into the fiber 10 slurry to insolubilize the.RP-l. Then if this mixture is de~atered on a vacuum filter there should be produced a preform which can be pressed and cured at about 230~
for 20 minutes into a finished board baving a hard, glossy surface.
:
.
: . 35 12t34~3 The related Canadian application 522,037, filed November 3rd, 1986 being concurrently filed in the name of differ-ent inventive entities discloses and claims compositions and methods using polyols broadly with crosslinkers which are hetero-cyclic compounds containing cyclic carbon-bonded hydroxy groups and having at the same time at least two nitrogen-bonded methylol or hydroxyethoxy methyl groups, as well as others.
Many variations of this invention will suggest them-selves to those skilled in this art in light of the above, detailed description. For example, instead of wood fiber or sand, clay, sawdust, wood chips and wood particles can be used. The hydrolyzed pregelled yellow corn flour can have the pH adjusted with ammonia. Instead of an extruder, gelatinization can be accompli~hed by an expander. Hydrolysi~ of the corn flour can be carried out with HCl instead of ~2S04. Acid modification of the corn flour can be carried out at 150-200F. Instead of nitrogen-bonded methylol groups in the crosslinker, alkoxyalkyl, especially methoxymethyl groups (which evolve alcohol instead of water on reaction with polyols), can be substituted. Instead of water as a solvent, lower alcohols, such as, but not limited to, methanol or ethanol and n-butanol can be used, as well as dioxane, methylene chloride, dimethylformamide and others known in this art; water is preferred. Instead of Lewis acid salts other acids can be used, including Bronsted acids. All such obvious variations are within the full intended scope of the appended claims.
In the production of foundry cores, there are a number of different methods for applying heat to the 25 formed cores to bring about a cure of the binder. These include cold forming followed by baking of the cores, forming the cores in heated patterns, sometimes called a hot bo~, and forming the cores in a pattern or box followed by forcing heated air through the core.
This invention can be used in any of the above methods. The advantages of this invention are ~i) the use of aqueous solvents which emit no odors or noxious fu es ~ii) that the binder system presents no air or water pollution hazards, and, especially, ~iii) the 35 hydrolytic stability of the bonded article is very high.
1~:84403 A bonded particulate article manufactured by the method of the present invention may preferably comprise 80~-99% particu-late matter and 1%-20% binder system, with the latter being com-prised of 20%-55% said polyol, said polyol being a saccharide material, 3%-60% of crosslinker, 0.2-10% of an acid and 15-85% of - solvent, by weight. If water is the solvent, part of the content can be contributed by moisture in the sand. Part also can be con-tributed by any solvent in which the crosslinker is contained.
A preferred method of manufacturing a foundry core under the present invention comprises the steps of mixing sand and a heat-accelerated curable binder system wherein the binder system i8 produced by the following steps, weight percentages being based on 100 parts of sand: crosslinking 1%-3% of hydrolyzed, gelatinized matter with 0.1-3% of a crosslinker as above defined in a 25-90%, preferably 40-60%, aqueous solution, controlling the reaction by the use of 0.01%-1%, preferably 0.3-1%, acid as a catalyst using 0%-10% clay, 0%-10% wood flour, 0%-10~ silica flour, 0%-10% iron oxide (as optional fillers), and 0%-3% of a material selected from the group comprising wax, wax emulsion, asphalt emulsion or wax-asphalt emulsion (as optional flow promoters and/or mold releases); and forming the mixture to desired shape and causing it to cure to a hardened state.
Preferred compositions for some processes include a release agent.
This can comprise a mixture of a paraffin solvent alone or including a fatty acid. A useful such composition is a mixture of kerosene and oleic acid in a weight ratio of from about 8:1 to about 1:1. The amount used can vary ~2844~
12a 61109-7496 but preferably is from 0.05 to 2% based on the sand, by weight.
In manufacturing a resinlike material with the present invention the method may include mixing a filler material and a heat-accelerated curable binder system, the binder system having been produced by cross-linking .;
.
, -` ~28~03 a hydrolyzed, gelatinized amylaceous substance with a heterocyclic cros~linker as defined above in the presence of an amount of an acid effective to maintain the reaction at a ~uitable rate during curing. The method of mising 5 can vary, but generally will include the following steps: (i) dissolving or disper~ing the acid, hydrolyzed, gelatinized amylaceous substance and heterocyclic compound in water; and (ii) causing the mixture to react by the application of heat. In one preferred way of operating, 10 prior to application of heat, up to 80% of the weight of the binder sy~tem of fillers, pigments and extenders are dispersed in the ~ystem. Eves re preferred, is to prcmi~ up to 80~ of the weight of the binder syste~ of filler~, pigments and estenders with the a~ylaceous 15 material, then to add the cross linker and the acid in admixture.
Cur~ng o the c~r~ w~ll be at conventional op~rating condition~, e.g., 5-180 ~econds in a hot ~ox, operated at bctween 250-550'P. The core usually will be 20 removed from the form and dried in an oven. Conventional techniques can be used. The core can be post-cured with microwave energy.
If the binder system is used with other fillers to make other ~haped articles, practices entirely conven-25 tional in those arts will be u~ed. Merely by way ofillustration, the crosslinker and the acid can be slurried in warm ~ater with wood fibers. Then hydrolyzed, gela-tinized corn flour can be added and ~lended. Dewatering on a vacuum filter give~ a damp preform which can bc 30 pressed and cured at 230-F for 20 minutes to produce a pressed fiberboard with a hard, glossy surface.
The following procedures are used to prepare materials used in the working examples.
~284~03 PROCEDURE A
A hydrolyzed, gelatinized amylaceous starch is made by the procedure of Example 25 of U.S. 4,158,574.
Eight S00 gm samples of yellow corn flour are blended with 0.2 to 0.4% ~2SO4 and tempered to 18-24%
moisture. After addition of acid and water, the samples are blended for 20 sinutes in a ~obart mixer at low speed. The samples are then processed in a laboratory 10 extruder employing a 220F rear barrel temperature and 280F for the discharge end 1/3 length. The e~truder is run at S0 rpm with a 2:1 compression screw. The extruded samples are cooled to roo~ temperature and ground on a haomermill. The 10~ slurry of the sample gives a p~ of 15 3.5-4.1. The products are then tested for cold water solubles and alkaline viscosities.
A typical product has a cold water solubles (C~S) of 12.8S, an alkaline viscosity of 20.3 seconds (1.3 g. of sample). After extrusion it has a CWS of 20 84.3% and an alkaline viscosity of 13.6 seconds (1.3 g.
sample).
The method for determining alkaline viscosities has been given above. The procedure for the cold water solubles (CWS) is as follows: A 20g. sample is weighed 25 and added to 480 g. of distilled water in a 600 ml.
beaker. A magnetic stirrer is used to disperse the material with stirring carried out for 5 minutes. (If the sample tends to lump when added to the water, addition is made by sifting the sample into the water Yith stirrer 30 running using a tea strainer.) The slurry is allowed to stand for one hour and then mixed again for 2 minutes.
The slurry is filtered using 18.5 cm. fluted paper (Reeve Angel t802 or equivalent). The first few cc's of ~iltrate are discarded. Ten ml. of the filtrate are 35 placed in a weighed aluminum weighing dish and the dish -~284403 and aliquot weighed. The aliquot is driea at 70C in a circulating air oven for 24t2 hours. The dried residue is weighed and the % solubles calculated.
PROCEDURE B (RP-l) A reaction product comprising glyoxal, urea and foemaldehyde is prepared by the following procedure:
A mi~ture of one mole of glyoxal (as a 40%
10 aqueous solution) and 2 moles of focmaldehyde (as a 44%
aqueous solution) is adusted to a p~ of 6.4-6.5 with sodium bicarbonate~ To this is added one mole of urea and the mixture is heated to 60C ~aintaining the p~ at 6.4-6.5 by fregyent additions of sodium ~icarbonate.
15 When the free formaldehyde content by analysis drops to 1~ the reaction mixture i8 cooled, the p~ adjusted to 3.0 with hydrochloric acid and water i8 added to adjust the solid~ content to 44-45~.
The compound has the formula /c~2o~
~0 C N
\C - O
~0 - C - N
~C~20~
PROCEDURE C-l (RP-2) A reaction proauc~ comprising glyoxal, urea, formaldehyde and et~ylene glycol is prepared by the following procedure:
In a reaction vessel, one mole of glyoxal (40.3~ glyoxal, 4.7~ aqueous solution) is mixed with two ~5 moles of fo~maldehyde (50% formalin aqueous solution), -1~8~
one mole of urea and 1.5 moles of ethylene glycol. The pa of the mixture is adjusted by addition of NaOB to a value in the range of 6 to 7 and is maintained in that range while the mixture is reacted at 60C for three 5 hours. Then about 0.5% by weight of citric acid, based on the weight of the finished product, is added to the mixture and the pH is adjusted to 3.0 by the addition of SO4. The temperature of the mixture is maintained at 60C for one hour, then cooled to about 25C and the p~
10 is finally adjusted to about 4.5 to 5.5 by the addition of NaO~ to make the finished product solution (solids content about 40-50% by weight).
The compound has the for~ula ~ ~ C~2OC~2C~2OH
~O-C - N
~C - O
~O-C N
~I C~20CB2C~1201I
PROC~DUR~ C-2 (RP-2) ;
As an alternate to C-l, the following procedure is suitable:
In a reaction vessel, one mole of glyoxal (40.3% glyoxal, 4.7% formaldehyde a~ueous solution) is mixed with two moles of formaldehyde (50% formalin aqueous solution), and one mole of urea. The pH of the misture is adjusted by the addition of NaO~ to a value in the 30 range of 6 to 7 and is maintained at that range while the mixture is reacted at 60C for three hours. Then 1.5 moles of ethylene glycol is added. Then about 0.5% by weight of ctiric acid, based on the weight of the finished product, is added to the mixture and the p~ is adjusted 35 to 3.0 by addition of H2SO4. The temperature of the -~284403 mixture is maintained at 60C for one hour, tben cooled to about 25C and the p~ is finally adjusted to about 4.5 to 5.5 by addition of NaO~ to make the finished product solution (solids content about 40 to 50% by 5 weight).
DESCRIPTION OF TE~E PREFE~RED EMBODIMENTS
The following Examples illustrate the present 10 invention, but are not intended to limit the claims.
The sand mixes in the examples are made in a Simpson Sand Muller. Silica sand and the polysaccharide of Procedure A are dry blended for 30 to 90 seconds.
Water is added and the system blended for two minutes.
15 An aqueous solution of the nitrogenous heterocyclic crosslinker of Procedures B or C and metal salt as specified is then added and ~he system ~s blended for two minute~. $he Standard A~erican Poundry Society l-inch tensile briquets are the~ prepared by hand ramming into 20 the tensile core boxes. The resulting 1~ thick dog-bone shaped cores are baked at 350F for 30 minutes. Tensile strengt~ is measured after 2 hours using a Detroit Testing ~achine Company Model CST testing machine.
2S E~MPLE 1 Based on 100 parts by weight of sand, 2% of amylaceous starch (cereal), 0.5% of the reaction product (RP-l) of glyoxal, urea and formaldehyde (Procedure B) 30 and 0.03% of zinc nitrate and 2.5% of water are mised, molded, cured and tested.
For comparison purposes, ~ixtures omitting the crosslinker and the ~ewis ac}d salt, and omitting the ~ewis acid salt, respectively, are prepared. The results 35 are as follows:
~28~403 Tensile Example %Cereal ~RP-l** %Zn(N03~2 %~2 Strength (psi) lA* 2 0.0 0.0 2.5 56 lB* 2 0.5 0.0 2.5 63 5 1 2 0.5 0.03 2.5 280 * Control ** Based on solids, 44% in water.
The foregoing results demonstrate the advanta-geous results achieved by the three-component binder system of the present invention.
To further demonstrate the advance in the art provided by the present invention, hydrolytic stability 15 tests were carried out. The test cores in the form of dog bone specimens prepared according to ~xample 1 were made and or compari on purposes ~pecimens prepared according to ~xa~ple 2 of ~.8. 4,0g8,615, which employed glyoxal as a crosslinker were made. Tensile strengths 20 were measured two hours after production and then exposure to 80% relative hu~idity at 80F for 16 hours. The for~ulations used and the results obtained are set forth as follows:
Tensile 2S Stren~th (psi) Esam- ~Cross as 80% R~
ple %Cereal linker %Catalvst %~2 made exPosed 1 2.0 0.5 RP-l 0.03 Zn(N03)2 2-5 280 200 lC~ 2.0 0.6 Glyo~al0.5 NaCl 2.8 274 50 The results show that the present invention provides bonded articles with substantial hYdrolytic stability resistance which permits their use in environ-ments, such as foundrys, with high ambient humidities.
.
~L28~a~03 The procedure of Example 1 is repeated. The amounts of RP-l, Zn(N03)2 and ~2 are the same as used in Example 1 and the hydrolyzed cereal is partially replaced in stages with a conventional cereal. The following results are obtained:
Example % Cereal ~ CC~ Tensile Strenqth (psi) 2 1.88 .12 195 3 1.5 .5 103 15 * Acid ~odified corn ~tarch (~rauJe Milling Co. UAmerikor~ brand).
Substitution of conventional cereals for part of the hydrolysed cereal in E~ample 1 results in a lower 20 core tensile strength. However E~amples 2-3 demonstrate that a conve~tional cereal (CC) can successfully be added in place o ~ome o the hydrolyzed amylaceous ~tarch. Other conventional cereals which can be used include wheat flour, rye starch, and the like.
The procedure of Example 1 i~ repeated with the e~ception that the amount of RP-l is increased.
.
.
128~03 ExamDle % Cereal % RP-l Tensile Strenqth (Psi) 4 2 .60 335 5 5 .2 .65 367 6 2 .75 420 It is seen that tensile strength increases with the level of RP-l.
A core is prepared as in the manner of Example 1 except it is prepared in a hot box and is post-cured in 15 a microwave oven for 30 sec. The core tensile strength i~ 334 p~i, demonstrating the beneficial e~fect of using a m~cro~ave oven.
A sand core is preFared as described in Example 1 except that magnesium nitrate is substituted for zinc nitrate and the reaction product from glyoxal, urea, formaldehyde and ethylene glycol ~RP-2, Procedure C-l) 25 is used in place of RP-l. The resulting tensile strength is 207 psi, demonstrating the beneficial effect of this system. If RP-2 made by the process of Procedure C-2 is used, substantially the same results will be obtained.
: 30 -1284~03 If the following composition is made: 16 g. of RP-l and 4 g. of zinc nitrate in 600 ml. of warm water is formed into a slurry with 80 g. of wood fibers.
Twenty g. of acid modified gelatinized corn flour (Procedure A) is then intimately blended into the fiber 10 slurry to insolubilize the.RP-l. Then if this mixture is de~atered on a vacuum filter there should be produced a preform which can be pressed and cured at about 230~
for 20 minutes into a finished board baving a hard, glossy surface.
:
.
: . 35 12t34~3 The related Canadian application 522,037, filed November 3rd, 1986 being concurrently filed in the name of differ-ent inventive entities discloses and claims compositions and methods using polyols broadly with crosslinkers which are hetero-cyclic compounds containing cyclic carbon-bonded hydroxy groups and having at the same time at least two nitrogen-bonded methylol or hydroxyethoxy methyl groups, as well as others.
Many variations of this invention will suggest them-selves to those skilled in this art in light of the above, detailed description. For example, instead of wood fiber or sand, clay, sawdust, wood chips and wood particles can be used. The hydrolyzed pregelled yellow corn flour can have the pH adjusted with ammonia. Instead of an extruder, gelatinization can be accompli~hed by an expander. Hydrolysi~ of the corn flour can be carried out with HCl instead of ~2S04. Acid modification of the corn flour can be carried out at 150-200F. Instead of nitrogen-bonded methylol groups in the crosslinker, alkoxyalkyl, especially methoxymethyl groups (which evolve alcohol instead of water on reaction with polyols), can be substituted. Instead of water as a solvent, lower alcohols, such as, but not limited to, methanol or ethanol and n-butanol can be used, as well as dioxane, methylene chloride, dimethylformamide and others known in this art; water is preferred. Instead of Lewis acid salts other acids can be used, including Bronsted acids. All such obvious variations are within the full intended scope of the appended claims.
Claims (35)
1. A curable composition adapted to produce a shaped bonded particulate article, said composition comprising (i) a particulate material; and, as a binder therefor, (ii) a polyol comprising a hydrolyzed, gela-tinized amylaceous material;
(iii) a crosslinker for said polyol (ii) comprising the reaction product of glyoxal, urea and formaldehyde, alone, or in further combination with ethylene glycol;
(iv) an acid catalyst; and (v) a solvent for the binder.
(iii) a crosslinker for said polyol (ii) comprising the reaction product of glyoxal, urea and formaldehyde, alone, or in further combination with ethylene glycol;
(iv) an acid catalyst; and (v) a solvent for the binder.
2. A curable composition as defined in Claim 1 wherein particulate material (i) comprises 80%-99% by weight and said binder comprises from 1%-20% by weight, the amount of polyol (ii) in said binder comprising 20%-55%; the amount of crosslinker (iii) in said binder comprising 3%-60%; the amount of acid (iv) in said binder comprising 0.2%-10% and the amount of solvent (v) in said binder comprising 15%-85%, all percentages being by weight.
3. A curable composition as defined in Claim 1 wherein the particulate material (i) is sand.
4. A curable composition as defined in Claim 1 wherein the polyol (ii) is the product of a process comprising the steps in the following sequence:
(a) hydrolyzing a material selected from corn flour, corn meal, corn grits, corn starch, sorghum flour, sorghum meal, sorghum grits, wheat flour, wheat starch, or a mixture of any of the foregoing at moistures between
(a) hydrolyzing a material selected from corn flour, corn meal, corn grits, corn starch, sorghum flour, sorghum meal, sorghum grits, wheat flour, wheat starch, or a mixture of any of the foregoing at moistures between
5 and 12% by weight of the humidified material using between 0.1 and 2% by weight acid;
(b) adjusting the pH of the acid hydrolyzed amylaceous material to between 3 and 6 obtained on a 10%
solids water slurry:
(c) gelatinizing the pH adjusted acid hydro-lyzed amylaceous material at moisture levels between 15 and 40% and at temperatures of between 212°F and 400°F;
(d) removing water from the gelatinized product; and (e) comminuting the dried amylaceous mass to a flour.
5. A curable composition as defined in Claim 1 wherein said crosslinker (iii) is a compound of the formulae or or a mixture of such compounds.
(b) adjusting the pH of the acid hydrolyzed amylaceous material to between 3 and 6 obtained on a 10%
solids water slurry:
(c) gelatinizing the pH adjusted acid hydro-lyzed amylaceous material at moisture levels between 15 and 40% and at temperatures of between 212°F and 400°F;
(d) removing water from the gelatinized product; and (e) comminuting the dried amylaceous mass to a flour.
5. A curable composition as defined in Claim 1 wherein said crosslinker (iii) is a compound of the formulae or or a mixture of such compounds.
6. A curable composition as defined in Claim 1 wherein said acid is an inorganic acid, an organic acid, a Lewis acid, a Bronsted acid or a metal or non-metal salt which acts as an acid.
7. A curable composition as defined in Claim 1 wherein said solvent is water.
8. A method of manufacturing a bonded particulate article comprising the steps of (i) admixing particulate material with a binder system, the binder system being formed by admixing a polyol comprising a hydrolyzed, gelatinized amylaceous material, a crosslinker for said polyol (ii) comprising the reaction product of glyoxal, urea and formaldehyde, alone, or in further combination with ethylene glycol, a solvent, and an acid;
(ii) forming the admixture into a shape; and (iii) curing to produce the bonded article.
(ii) forming the admixture into a shape; and (iii) curing to produce the bonded article.
9. A method as defined in Claim 8 wherein step (ii) is carried out in a heated mold, and step (iii) is carried out by removing the article from the heated mold and allowing it to cool.
10. A method as defined in Claim 8 wherein said crosslinker is a compound of the formula or 25 or a mixture of such compounds.
11. A method as defined in Claim 8 wherein the solvent is water.
12. A method as defined in Claim 11 wherein the particulate material is sand.
13. A bonded particulate article manufactured by the method of Claim 8 and comprising, before curing, 80%-99% of particulate material and 1%-20% of binder system with the latter being comprised of 20%-55% of said polyol, said polyol being a saccharide material, 3%-60% of crosslinker, 0.2%-10% of an acid, and 15%-85% of solvent, by weight.
14. A bonded particulate article as defined in Claim 13 wherein the particulate material is sand and the bonded article is a foundry core.
15. A method of manufacturing a bonded particulate article comprising the steps of (i) admixing a particulate material with a binder system wherein the latter is formed by admixing a hydrolyzed, gelatinized amylaceous material with a crosslinker for said amylaceous material comprising the reaction product of glyoxal, urea and formaldehyde, alone, or in further combination with ethylene glycol, a solvent, and an acid;
(ii) forming the article in a mold; and (iii) desolventizing the article.
26a 61109-7496
(ii) forming the article in a mold; and (iii) desolventizing the article.
26a 61109-7496
16. A method as defined in Claim 15 wherein the desolventizing is accomplished by the application of heat.
17. A method as defined in Claim 15 wherein the application of heat is accomplished at least in part by use of microwave energy.
18. A method as defined in Claim 15 wherein the solvent is water.
19. A method as defined in Claim 15 wherein said crosslinker is a compound of the formulae or or a mixture of such compounds.
20. A bonded particulate article manufactured by the method of Claim 15 comprising, before desolven-tizing, 80%-99% of particulate material and 1%-20% of binder system, with the latter being comprised of 20%-55%
of hydrolyzed, gelatinized amylaceous material, 3%-60%
of crosslinker, and 0.2%-10% of an acid, and 15-85% of solvent, by weight.
of hydrolyzed, gelatinized amylaceous material, 3%-60%
of crosslinker, and 0.2%-10% of an acid, and 15-85% of solvent, by weight.
21. An article as defined in Claim 20 wherein the particulate material is sand and the article is a foundry core.
22. A method of manufacturing a formed article comprising:
(a) dispersing fillers, extenders and pigments in a hydrolyzed, gelatinized amylaceous material in an amount up to 80%, and adding water to the mixture;
(b) adding a mixture of a heterocyclic compound of the formulae or or a mixture of such compounds, and water;
(c) controlling the rate of the crosslinking reaction between the hydrolyzed, gelatinized amylaceous material and said heterocyclic compound by the use of an acid;
(d) forming the mixture into a shape; and (e) causing the mixture to cure by the application of heat.
(a) dispersing fillers, extenders and pigments in a hydrolyzed, gelatinized amylaceous material in an amount up to 80%, and adding water to the mixture;
(b) adding a mixture of a heterocyclic compound of the formulae or or a mixture of such compounds, and water;
(c) controlling the rate of the crosslinking reaction between the hydrolyzed, gelatinized amylaceous material and said heterocyclic compound by the use of an acid;
(d) forming the mixture into a shape; and (e) causing the mixture to cure by the application of heat.
23. A method as defined in Claim 22 wherein the mixture used in steps (a), (b), and (c) is within the limits of 15-85% water, 20-55% amylaceous material, 3-60% heterocyclic compound and 0.2-10% acid.
24. A method of manufacturing a resinlike material suitable for formed articles with a binder produced by the following steps:
(a) crosslinking a hydrolyzed, gelatinized amylaceous material with a heterocyclic compound of the formula or a mixture of such compounds in water;
(b) controlling the rate of the crosslinking reaction between the hydrolyzed gelatinized amylaceous material and said heterocyclic compound by the use of an acid salt; and said method including the following steps;
(c) dissolving or dispersing the acid, hydrolyzed, gelatin-ized amylaceous material and said heterocyclic compound in water;
and (d) causing the mixture to react by the application of heat.
(a) crosslinking a hydrolyzed, gelatinized amylaceous material with a heterocyclic compound of the formula or a mixture of such compounds in water;
(b) controlling the rate of the crosslinking reaction between the hydrolyzed gelatinized amylaceous material and said heterocyclic compound by the use of an acid salt; and said method including the following steps;
(c) dissolving or dispersing the acid, hydrolyzed, gelatin-ized amylaceous material and said heterocyclic compound in water;
and (d) causing the mixture to react by the application of heat.
25. A method as defined in Claim 24 wherein prior to the application of heat up to 80% the weight of the binder system of fillers, pigments and extenders are diRpersed in the binder system.
26. A method as defined in Claim 24 wherein up to 80% of the weight of the binder system of fillers, pigments and extenders are pre-mixed with the hydrolyzed, gelatinized amylaceous material and steps (a) and (b) are carried out simultaneously.
27. A method of manufacturing a foundry core comprising mix-ing sand and heat-accelerated curable binder system wherein the binder system is produced by the following steps,the percentages being a percent of sand:
(a) crosslinking about 1-3% of a hydrolyzed gelatinized amylaceous material with about 0.1-3% of a crosslinker comprising a heterocyclic compound of the formula in about a 40 to 60% aqueous solution and (b) controlling the rate of reaction by the use of 0.3-1.0%
of an acid as a catalyst, said mixture also comprising 0-10% clay, 0-10% silica flour, 0-10% iron oxide, and an effective amount of a release agent selected from the group comprising wax, wax emulsion asphalt emulsion, and wax-asphalt emulsion, (c) forming the mixture to desired shape and, (d) causing it to cure to a hardened state.
29a 61109-7496
(a) crosslinking about 1-3% of a hydrolyzed gelatinized amylaceous material with about 0.1-3% of a crosslinker comprising a heterocyclic compound of the formula in about a 40 to 60% aqueous solution and (b) controlling the rate of reaction by the use of 0.3-1.0%
of an acid as a catalyst, said mixture also comprising 0-10% clay, 0-10% silica flour, 0-10% iron oxide, and an effective amount of a release agent selected from the group comprising wax, wax emulsion asphalt emulsion, and wax-asphalt emulsion, (c) forming the mixture to desired shape and, (d) causing it to cure to a hardened state.
29a 61109-7496
28. A method as defined in Claim 27 including the step of curing the core for 5-180 seconds in a hot box at a temperature between 250°-550°F.
29. A method as defined in Claim 28 followed by the step of postcuring the core by microwave energy.
30. A method as defined in Claim 27 wherein the amylaceous material is the product of a process com-prising the steps in the following sequence:
(a) hydrolyzing a material selected from corn flour, corn meal, corn grits, corn starch, sorghum flour, sorghum meal, sorghum grits, wheat flour, wheat starch, or a mixture of any of the foregoing at moistures between 5 and 12% by weight of the humidified material using between 0.1 and 2% by weight acid;
(b) adjusting the pH of the acid hydrolyzed amylaceous material to between 3 and 6 obtained on a 10%
solids water slurry;
(c) gelatinizing the pH adjusted acid hydro-lyzed amylaceous material at moisture levels between 15 and 40% and at temperatures of between 212°F and 400°F;
(d) removing water from the gelatinized product; and (e) comminuting the dried amylaceous mass to a flour.
(a) hydrolyzing a material selected from corn flour, corn meal, corn grits, corn starch, sorghum flour, sorghum meal, sorghum grits, wheat flour, wheat starch, or a mixture of any of the foregoing at moistures between 5 and 12% by weight of the humidified material using between 0.1 and 2% by weight acid;
(b) adjusting the pH of the acid hydrolyzed amylaceous material to between 3 and 6 obtained on a 10%
solids water slurry;
(c) gelatinizing the pH adjusted acid hydro-lyzed amylaceous material at moisture levels between 15 and 40% and at temperatures of between 212°F and 400°F;
(d) removing water from the gelatinized product; and (e) comminuting the dried amylaceous mass to a flour.
31. A method as defined in Claim 27 wherein the acid is selected from acetic acid, hydrochloric acid, sulfuric acid, a zinc salt, a magnesium salt, an aluminum salt or a mixture of any of the foregoing.
32. A method as defined in Claim 31 wherein the acid is zinc nitrate.
33. A method as defined in Claim 31 wherein the acid is magnesium nitrate.
34. A method as defined in Claim 27 which includes the step of removing the core from the form and drying the core.
35. A method as defined in Claim 34 wherein the drying is performed in an oven.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/795,068 | 1985-11-05 | ||
| US06/795,068 US4711669A (en) | 1985-11-05 | 1985-11-05 | Method of manufacturing a bonded particulate article by reacting a hydrolyzed amylaceous product and a heterocyclic compound |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1284403C true CA1284403C (en) | 1991-05-28 |
Family
ID=25164573
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000522027A Expired - Fee Related CA1284403C (en) | 1985-11-05 | 1986-11-03 | Method of manufacturing a bonded particulate article by reacting a hydrolyzed amylaceous product and a heterocyclic compound |
Country Status (10)
| Country | Link |
|---|---|
| US (1) | US4711669A (en) |
| EP (1) | EP0221537A3 (en) |
| JP (1) | JPS62174241A (en) |
| KR (1) | KR870004746A (en) |
| CN (1) | CN1019128B (en) |
| AU (1) | AU588930B2 (en) |
| BR (1) | BR8605433A (en) |
| CA (1) | CA1284403C (en) |
| NO (1) | NO864392L (en) |
| ZA (1) | ZA868413B (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4814012A (en) * | 1985-11-05 | 1989-03-21 | American Cyanamid Company | Method of manufacturing a bonded particulate article by reacting a hydrolyzed amylaceous product and a heterocyclic compound |
| US4705570A (en) * | 1985-11-05 | 1987-11-10 | American Cyanamid Company | Method of manufacturing a bonded particulate article by reacting a polyol and a meterocyclic compound |
| IT1207835B (en) * | 1987-03-04 | 1989-06-01 | Mi Chi Sa Mineraria Chimica Sa | GREEN FORMING LAND ADDITIVE. |
| GB2253170B (en) * | 1991-02-28 | 1994-08-10 | Ae Piston Products | Removable cores for metal castings |
| US5851634A (en) | 1992-08-11 | 1998-12-22 | E. Khashoggi Industries | Hinges for highly inorganically filled composite materials |
| US5580624A (en) | 1992-08-11 | 1996-12-03 | E. Khashoggi Industries | Food and beverage containers made from inorganic aggregates and polysaccharide, protein, or synthetic organic binders, and the methods of manufacturing such containers |
| US5545450A (en) | 1992-08-11 | 1996-08-13 | E. Khashoggi Industries | Molded articles having an inorganically filled organic polymer matrix |
| US5709827A (en) * | 1992-08-11 | 1998-01-20 | E. Khashoggi Industries | Methods for manufacturing articles having a starch-bound cellular matrix |
| US5582670A (en) | 1992-08-11 | 1996-12-10 | E. Khashoggi Industries | Methods for the manufacture of sheets having a highly inorganically filled organic polymer matrix |
| US5506046A (en) | 1992-08-11 | 1996-04-09 | E. Khashoggi Industries | Articles of manufacture fashioned from sheets having a highly inorganically filled organic polymer matrix |
| US5830305A (en) | 1992-08-11 | 1998-11-03 | E. Khashoggi Industries, Llc | Methods of molding articles having an inorganically filled organic polymer matrix |
| US5800647A (en) | 1992-08-11 | 1998-09-01 | E. Khashoggi Industries, Llc | Methods for manufacturing articles from sheets having a highly inorganically filled organic polymer matrix |
| US5928741A (en) | 1992-08-11 | 1999-07-27 | E. Khashoggi Industries, Llc | Laminated articles of manufacture fashioned from sheets having a highly inorganically filled organic polymer matrix |
| US5783126A (en) * | 1992-08-11 | 1998-07-21 | E. Khashoggi Industries | Method for manufacturing articles having inorganically filled, starch-bound cellular matrix |
| US5683772A (en) * | 1992-08-11 | 1997-11-04 | E. Khashoggi Industries | Articles having a starch-bound cellular matrix reinforced with uniformly dispersed fibers |
| US5660903A (en) | 1992-08-11 | 1997-08-26 | E. Khashoggi Industries | Sheets having a highly inorganically filled organic polymer matrix |
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|---|---|---|---|---|
| US2661312A (en) * | 1951-06-14 | 1953-12-01 | Du Pont | Textile finishing composition and method of treating textile materials therewith |
| DE910475C (en) * | 1951-08-17 | 1954-05-03 | Basf Ag | Process for the production of nitrogen-containing condensation products |
| US4013629A (en) * | 1975-02-21 | 1977-03-22 | Krause Milling Company | Art of catalyzing the reaction between a polyol and a polyaldehyde |
| JPS56144841A (en) * | 1980-04-11 | 1981-11-11 | Sintokogio Ltd | Binder for molding sand |
| US4400480A (en) * | 1981-06-01 | 1983-08-23 | National Starch And Chemical Corporation | Process for preparing corrugated paperboard |
| US4705570A (en) * | 1985-11-05 | 1987-11-10 | American Cyanamid Company | Method of manufacturing a bonded particulate article by reacting a polyol and a meterocyclic compound |
-
1985
- 1985-11-05 US US06/795,068 patent/US4711669A/en not_active Expired - Fee Related
-
1986
- 1986-11-03 CA CA000522027A patent/CA1284403C/en not_active Expired - Fee Related
- 1986-11-04 EP EP86115276A patent/EP0221537A3/en not_active Withdrawn
- 1986-11-04 BR BR8605433A patent/BR8605433A/en unknown
- 1986-11-04 NO NO864392A patent/NO864392L/en unknown
- 1986-11-04 ZA ZA868413A patent/ZA868413B/en unknown
- 1986-11-04 KR KR860009288A patent/KR870004746A/en not_active Application Discontinuation
- 1986-11-04 AU AU64803/86A patent/AU588930B2/en not_active Ceased
- 1986-11-05 JP JP61263641A patent/JPS62174241A/en active Pending
- 1986-11-05 CN CN86107618A patent/CN1019128B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| NO864392D0 (en) | 1986-11-04 |
| CN1019128B (en) | 1992-11-18 |
| AU588930B2 (en) | 1989-09-28 |
| AU6480386A (en) | 1987-05-07 |
| BR8605433A (en) | 1987-08-11 |
| US4711669A (en) | 1987-12-08 |
| CN86107618A (en) | 1987-08-12 |
| NO864392L (en) | 1987-05-06 |
| EP0221537A2 (en) | 1987-05-13 |
| JPS62174241A (en) | 1987-07-31 |
| EP0221537A3 (en) | 1988-08-24 |
| ZA868413B (en) | 1987-06-24 |
| KR870004746A (en) | 1987-06-01 |
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