WO1988007074A1

WO1988007074A1 - Preparation of solutions of metal soaps in amines

Info

Publication number: WO1988007074A1
Application number: PCT/US1988/000554
Authority: WO
Inventors: Edgar N. Nelson; Daniel F. Scully
Original assignee: Mallinckrodt, Inc.
Priority date: 1987-03-16
Filing date: 1988-02-16
Publication date: 1988-09-22
Also published as: AU1488488A

Abstract

There is disclosed an in-situ reaction process for preparing a storage-stable plastics-processing solution including a zinc carboxylate soap dissolved in a plastics-processing amine. The solution is prepared by saponification of a carboxylic acid having about 8 to about 22 carbon atoms with a zinc compound dispersed in the amine.

Description

PREPARATION OF SOLUTIONS OF METAL SOAPS IN AMINES

This invention relates to an in-situ reaction process for preparing a storage-stable plastics-processing solution comprising a zinc carboxylate soap dissolved in a 5 plastics-processing amine.

Plastics-processing solutions containing zinc carboxylate salts dissolved in plastics-processing amines have heretofore been known. See Taylor et al., U.S. Patent 4,519,965, which describes an internal mold release agent

, mixture comprising (a) a zinc carboxylate containing 8 to .24 carbon atoms per carboxylate group and (b) a compatibilizer in an amount sufficient to solubilize the zinc carboxylate. The compatibilizers include nitrogen-containing, isocyanate— reactive, acyclic compounds such as aliphatic polya ines and 5 nitrogen-containing, isocyanate-reactive polymers, preferably polyethers. Compatibilizers preferred therein include polyether polyamines and amine- or hydroxyl-terminated, amine-initiated polyethers (i.e., polyethers obtained by the addition of alkylene oxides such as ethylene oxide and/or _Q propylene oxide to aromatic or aliphatic polyamines, optionally followed by amination). Specific examples set forth therein of nitrogen-containing, isocyanate-reactive polymers are polyoxypropylene diamines (supplied as Jeffamine D-230, Jeffamine D-400 and Jeffamine D-2000 - all from 5 Texaco), polyoxypropylene triamines (supplied as Jeffamine T-403 and Jeffamine T-5000 from Texaco), an ethylene diamine-based polyether polyol (supplied as Multranol 4050 from Mobay) and a toluene diamine-bas,ed polyether polyol (supplied as Multranol 9136 from Mobay). Accord ng to t e patent, t e nterna mo re ease agent mixture is included in a reaction mixture which further includes (I) a polyisocyanate (e.g. a liquid polyisocyanate) , (II) an isocyanate.-reactive polymer (e.g. a high molecular weight polyol), and (III) a chain extender comprising a sterically hindered aromatic diamine. The reaction mixture is processed as a one-shot system by the reaction injection molding ("RIM") process to produce polyurethane elastomer molding.

The patent discloses preparation of the internal mold release mixture by adding the solid zinc carboxylate to the compatibilizer and heating this mixture at elevated temperatures (about 80°-120°C) with continual or occasional stirring until a clear solution is obtained.

The patent specifically exemplifies the mold release agent mixture and its preparation by a "1:1 solution of zinc stearate/polyether polyamine I" prepared by first adding 8 parts of zinc stearate to 8 parts of the polyether polyamine (an approximately 400 MW difunctional primary amine terminated polyether supplied by Texaco as Jeffamine D-400). After two hours in an oven at 100°C with stirring every 15 minutes, the mixture is described therein as a "clear solution which remained clear upon cooling to ambient temperature."

Preparation of the above-described mold release agent solution and other plastics-processing solutions has heretofore required a 2-stage operation, namely (1) preparing a solid metal carboxylate and (2) thereafter dissolving the solid carboxylate in the desired plastics-processing amine. The heretofore known operation has not been entirely satisfactory from suuh standpoints as efficiency and economy. For example, in commercial practice, preparation of metal carboxylates such as zinc carboxylate requires supplying heat to a reaction system to attain elevated temperatures, typically in the range of 80° to 120°C, followed by recovery

5 operations to recover the metal carboxylate as a solid. These operations involve release of heat, which typically is lost, in order to cool and solidify the metal carboxylate. In accordance with the above-cited U.S. Patent 4,519,965, heat is again supplied in heating the mixture of solid carboxylate and

2_0 amine to elevated temperature (80°-120°C) in order to obtain a solution. Stirring is also required in both above-described stages. Thus, duplicative heating and stirring are employed in such two-stage operation, which is accordingly inefficient and costly. Moreover, commercially available metal

_]_5 carboxylates, which are prepared by a variety of processes, vary in a number of respects, including type and amount of impurities, e.g. by-products of the reaction such as amides, esters, other salts and/or water. Such variation may account for observations, made in the course of work leading to this

20 invention, that some commercially available metal carboxylates (including some commercially available zinc stearates) will not form stable solutions upon attempted dissolution thereof in amines, such as polyoxypropylene diamine (e.g. Jeffamine D-400) and polyoxypropylene triamine (Jeffamine T-403).

5 Accordingly, there is a substantial need in the art for an improved process for preparing storage-stable plastics-processing solutions of metal carboxylate soaps dissolved in plastics-processing amines. The present invention substantially fulfills such need. DESCRIPTION OF THE INVENTION

This invention provides an in-situ reaction process for preparing a storage-stable plastics-processing solution comprising a zinc carboxylate soap dissolved in a plastics-processing amine, said process comprising

(A) preparing a liquid reaction mixture comprising (a) an amine in liquid or molten state, (b) a zinc compound selected from the group consisting of zinc oxide, zinc hydroxide and zinc carbonate and (c) a carboxylic acid having

10 from about 8 to about 22 carbon atoms, said zinc compound and said carboxylic acid being dispersed throughout said amine,

(B) effecting.reaction of said zinc compound with said carboxylic acid compound in said reaction mixture under saponification reaction conditions comprising (a) the -re temperature of said reaction mixture being from about 70°C to about 120°C, (b) said reaction mixture being continually stirred, thereby preparing (i) a solution in said amine of the zinc carboxylate soap of said carboxylic acid and (ii) water of reaction, and

2o (C) removing a sufficient amount of water such that said solution contains not more than 0.5% by weight water.

DETAILED DESCRIPTION OF THE INVENTION AND OF

THE MANNER AND PROCESS OF MAKING AND USING IT

Surprisingly, the reaction can be effected without using catalysts (such as citric acid) and without including water as a component of the initial reaction mixture.

Moreover, it has unexpectedly been found that the reaction can be carried to substantially complete conversion (e.g. 96% and even 96.5% or more) of the carboxylic acid to zinc carboxylate in relatively short time using at least 0.99 gram-equivalent of zinc compound (e.g. 1 to 1.2 gram-equivalents of zinc oxide) per 1 gram-mole of the carboxylic acid. The extent of reaction can be measured by free fatty acid. For example, a free fatty acid content of 2% (based on the total amount of fatty carboxylic acid included in the reaction mixture) corresponds to 98% conversion of such acid.

As used herein, the term "plastics processing amine" means an amine useful as an additive for plastics and/or as an agent for processing plastics. Amines having molecular weight of at least 230 are useful as antistatic additives for plastics, i.e. when incorporated into plastics (e.g. polyolefins) such amines reduce static electricity of the plastics. Internal mold release agent mixtures described in Taylor et al., U.S. Patent 4,519,965 (incorporated herein by reference), include aliphatic polyamines, polyether polyamines and amine-terminated or hydroxyl-terminated, amine-initiated polyethers as a combatibilizer for a zinc carboxylate component. All such amines are included by the term plastics-processing amine.

As used herein, the term "plastics-processing solution" means a solution comprising a zinc carboxylate soap dissolved in a plastics-processing amine. The solutions are useful as additives for plastics and/or as agents for processing plastics.

Amines suitable for use herein include, for example, _ς aliphatic hydrocarbyl fatty primary amines represented by the formula R H2 where R is a linear or branched, saturated or unsaturated aliphatic hydrocarbyl group having from about 10 to about 18 carbon atoms. Illustrative of these amines are lauryl amine, myristyl amine, palmityl amine, stearyl amine,

10 isostearyl amine and oleyl amine. Mixtures of such primary fatty amines may also be used. Such mixtures include, for example, tallow amine, tall oil amine and coco amine or coconut oil amine. Tallow amine is a mixture of amines derived from tallow acid and normally includes, as principal

■JJ- components: stearyl amine (e.g. 63-65%), palmityl amine (e.g. 33-35%), oleyl amine (e.g. 1% or less) and myristyl amine (e.g. 2% or less). Similarly, tall oil amine is a mixture of amines derived from tall oil acid, while coco amine is a mixture of amines derived from coconut acid (containing o hydrocarbyl chains having principally 10, 12, 14 and 16 carbon atoms) .

Suitable amines also include tertiary amines derived from the foregoing fatty primary amines by alkoxylation 5 thereof with ethylene oxide or propylene oxide to the corresponding N,N-bis-2-hydroxyethyl-R-amines or N,N-bis-2-hydroxypropyl-R-amines, respectively, where R is a hydrocarbyl group as defined above (e.g. lauryl, palmityl, stearyl, oleyl, etc.). These amines are represented by the 0 formula R ( ^)2 where R is as defined above and R¹ is

2-hydroxyethyl or 2-hydroxypropyl. Mixtures of such tertiary amines are also suitable. Such mixtures include, for example, a mixture of tertiary amines derived from a mixture of fatty acids (such as tallow acid, coconut acid, tall oil acid or the like) by high pressure reaction of the mixture of acids with ammonia to prepare the corresponding nitriles, hydrogenation of the nitriles to the corresponding primary amines and ethoxylation or propoxylation of the primary amines with 2 moles of ethylene oxide or propylene oxide per mole of amine. A preferred tertiary amine is N,N-bis-2-hydroxyethyl stearyl amine.

Amines suitable for use herein also include N,N' , N'-tris-( 2-hydroxyethyl)-N-R-l ,3-diaminopropane where R is a hydrocarbyl group as defined above (e.g. lauryl, palmityl, stearyl, oleyl, etc.). These amines are represented by the formula (R¹ )2N-CH2CH2CH2-NRR¹ where R is as defined above and R^- is 2-hydroxyethyl or 2-hydroxypropyl. Mixtures of such diaminopropane-based amines are also suitable. Such mixtures may be derived, for example, from tallow acid, coconut acid, tall oil acid or the like in a manner analogous to the above preparation of N, N-bis-2-hydroxyethyl(or hydroxypropyl)-R-amine. In this case, the primary amines obtained from the nitriles are reacted with acrylonitrile to prepare the corresponding amine-acrylonitrile adducts. Thereafter the adducts are hydrogenated to the corresponding diamines, followed by ethoxylation with 3 moles of ethylene oxide per mole of the diamine. The corresponding N,N' ,N'-tris-( 2-hydroxypropyl )-N-R-l ,3-diaminopropanes where R is as defined above are also suitable for use as the amine herein. In the preparation of these compounds, ethylene oxide is replaced by an equimolar amount of propylene oxide.

Suitable amines also include polyoxypropylene diamines having molecular weight from about 200 to about 2000 represented by the formula H2 -CH(CH3 )-CH2 [O-CH2— CH(C_Ϊ3) ]_x-0-CH2-CH(CH3)-NH2 wherein x is a number from 2 to about 35, and mixtures thereof. A line of such mixtures is commercially available from Texaco, Inc. as Jeffamine (D Series) diamines. One such mixture, Jeffamine D-230, has an average val of x of about 2.6 and an average molecular weight ( "MW" ) of abou

230. Also available and suitable herein are the mixtures

Jeffamine D-400 (average value of x. is about 5.6, average MW is about 400) and Jeffamine D-2000 (average value of x. I^s about 33.1 average MW is about 2000).

Suitable amines also include polyoxypropylene triamines having molecular weight (MW) from about 277 to about 5000, e.g. 1,1,1-trimethylolpropane polyoxypropylene triamine ("TPT") havin MW from about 305 to about 5000 or more and mixtures thereof. T TPT compounds and mixtures can be represented by the formula C₂H₅C(CH2Y) (CH2Y' ) (CH2Y") where Y, Y¹ and Y" are independently represented by the formula - [0-CH₂-CH(CH3 ) ]_£L-0-CH2-CH(CH3 )- H2 and 11 is zero or a number from 1 to about 35. One such polyoxypropylene triamine is available from Texaco Inc. as Jeffamine T-403, which has molecular weight of about 403. Another such polyoxypropylene triamine is available from Texaco Inc. as Jeffamine T-5000, having molecular weight of approximately 5000.

Also included among the suitable amines are hydroxyethyl imidazoline derivatives of fatty acids such as (a) l-(2-hydroxyeth l)-2-(aliphatic hydrocarbyl)-2— imidazolines; (b) the corresponding primary amine terminated compounds - i.e. the l-( 2-aminoethyl)-2- (aliphatic hydrocarbyl)-2-imidazolines; and (c) the corresponding tertiary amine imidazoline compounds derivable by alkoxylation of the terminal -NH2 group of the primary amine terminated compounds with ethylene oxide or propylene oxide to replace each H with a 2-hydroxyethyl or 2-hydroxypropyl group. The aliphatic hydrocarbyl group in the imidazoline derivatives is a linear or branched, saturated or unsaturated structure

5 containing from about 9 to about 17 carbon atoms. The

2-aminoethyl groups in compounds (b) and (c) are generically represented by the formula (R^)2 -CH2-CH2- where R^ is H (i.e., a hydrogen atom), a 2-hydroxyethyl group or a 2-hydroxypropyl group. Illustrative of such groups are

■_jQ n-heptadecyl, isoheptadecyl, heptadecenyl, pentadecyl, undecyl and the like. Mixtures of these imidazolines are also suitable. Such mixtures include the 2-hydroxyethyl imidazoline derivatives of mixed fatty acids such as tallow acid, tall oil acid, coconut acid and the like. An _j_ illustrative compound is l-(2-hydroxyethyl)-2-n-heptadeceny1-2-imidazoline.

Other suitable amines include polyamine-based polyols containing zero, one, two or more alkoxy (e.g., ethoxy and/or propoxy) groups wherein the polyamine is, for example, 0 an aliphatic polyamine (e.g., ethylene diamine), toluene diamine (e.g., 2,6-toluene diamine) or the like. Such polyols containing an alkoxy group are sometimes referred to as "ether polyols" or "alkoxy polyols" while those containing two or more alkoxy groups are sometimes referred to as "polyether 5 polyols" or "polyalkoxy polyols". Included among these compounds are the alkoxylation products, preferably the ethoxylation products and more preferably the propoxylation products, of (a) ethylene diamine, such as N,N,N' ,N'-tetrakis-(2-hydroxypropyl)ethylene diamine, 0 which can be obtained by propoxylation of ethylene diamine by 4 moles of propylene oxide per mole of ethylene diamine, and the corresponding mono- or poly-propoxy compounds obtained by propoxylation of ethylene diamine by 5 or at least 6 moles of propylene oxide, respectively, per mole of ethylene diamine and of (b) toluene diamine, such as

N,N,N' ,N'-tetrakis-(2-hydroxypropyl)toluene diamine, which can be obtained by propoxylation of toluene diamine by 4 moles of propylene oxide per mole of toluene diamine, and the corresponding mono- or poly-propoxy compounds obtained by propoxylation of toluene diamine by 5 or at least 6 moles of propylene oxide, respectively, per mole of toluene diamine.

Carboxylic acids suitable for use herein are aliphatic hydrocarbyl fatty carboxylic acids containing from about 8 to about 22 carbon atoms wherein the hydrocarbyl group is linear or branched, saturated or unsaturated and hydroxyl-substituted or unsubstituted. Illustrative acids are capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, abietic acid, isostearic acid, hydroxystearic acid, neodecanoic acid, oleic acid, linoleic acid, linolenic acid, octanoic acid, 2-ethyl-hexanoic acid, pelargonic acid and compatible mixtures of two or more of the foregoing acids. Such mixtures include, for example, tallow acid, tall oil acid, coconut acid and castor acid. Tallow acid is a mixture of acids derived from tallow and normally includes, as principal components: stearic acid (e.g. 63-65%), palmitic acid (e.g. 33-35%), oleic acid (e.g. 1% or less) and myristic acid (e.g. 2% or less). Similarly, tall oil acid is a mixture of acids derived from tall oil, while coconut acid is a mixture of acids derived from coconut oil (containing hydrocarbyl chains having principally 10, 12, 14 and 16 carbon atoms) and castor acid is a mixture of acids derived from castor oil. Hydrogenated tallow acid comprising a mixture of stearic acid and palmitic acid is commercially available and preferred. I i

The zinc compound may be zinc oxide, zinc hydroxide, zinc carbonate or a mixture of two or more of these compounds. Zinc oxide is preferred.

The liquid reaction mixture can be prepared in any suitable manner. Preferably, while the amine is in the liquid state, the zinc compound in preferably pulverulent form is added thereto with stirring to prepare a liquid dispersion wherein the zinc compound (insoluble in the amine) is dispersed substantially uniformly throughout the liquid amine. As will be apparent to those skilled in the art, the minimum temperature at which the amine is in the liquid state under conditions of thermal equilibrium is the melting point of the amine. If the particular amine is a liquid at room temperature (i.e. 20-25°C), the dispersion can conveniently be formed at such temperature. If the amine is a solid at room temperature, it preferably is liquefied by heating to a temperature of at least its melting point prior to adding the zinc compound.

Next, the resulting liquid dispersion of the zinc compound in the amine is heated to a temperature at least about equal to the melting point of the carboxylic acid to be saponified and, preferably, from about 60°C to about 79°C and, more preferably, from about 70°C to about 79°C.

To the heated dispersion there is added with stirring the carboxylic acid to be saponified. This addition is accompanied by stirring such that the acid is dispersed in the amine dispersion of the zinc compound. Next, with continual stirring the resulting reaction mixture is heated to a temperature of about 80°C to about 120°C, preferably about 80°C to about 110°C and, more preferably, from about 88°C to about 98°C. Such reaction conditions are maintained for a i l period of time such that the ensuing reaction of the zinc compound with the carboxylic acid proceeds to a desired extent, preferably to substantial completion, (i.e. at least 95% conversion of the reactant employed in stoichiometrically limiting amount) . Where stoichiometric equivalent amounts of the reactants are employed, each reactant is employed in such limiting amount.

The acid can be added in solid (e.g. flaked) or liquid form. Preferably, the acid is added in liquid form and more preferably at a temperature at least as high as the temperature of the heated amine dispersion of the zinc compound.

The stoichiometric amount of zinc oxide or other zinc compound is 0.5 gram-mole (i.e., 1.0 gram-equivalent or molar equivalent) of zinc compound per gram-mole of the carboxylic acid. The zinc compound may be added in any suitable amount, e.g. from about 0.95 to about 1.30 gram-equivalents per gram-mole of the carboxylic acid (i.e., an amount from about 5% stoichiometric excess carboxylic acid to about 30% stoichiometric excess zinc compound). As a general preference, the zinc compound is added in an amount from about 1.0 to about 1.3 gram-equivalents per gram-mole of the carboxylic acid.

Where the solution being prepared employs polyether polyamine (e.g. poloxypropylene diamine of the Jeffamine D

Series or polyoxypropylene triamine of the Jeffamine T Series) as the amine and the solution is intended to be suitable for internal mold release use in a one-shot RIM polyurethane molding process of the type described in Taylor et al. , U.S. Patent 4,519,965, the zinc compound is preferably added in an amount from about 1.001 to about- 1.05 gram-equivalents per mole of the carboxylic acid (i.e. about 0.1-5% stoichiometric excess zinc compound). Such amount of zinc compound results in clear solutions having a good balance of relative freedom from unreacted fatty acid and relative freedom from unreacted zinc compound reactant, where the reaction is carried to substantial completion.

Where the solution being prepared employs tertiary amines such as N,N-bis-2-hydroxy(C2 to C3 alkyl) (Cχo to Cχ8 aliphatic hydrocarbyl) amine (e.g. N,N-bis-2— hydroxyethyl stearyl amine) and the solution is intended to be suitable for use as a combination antistatic agent and lubricating agent in polyolefins or the like, the zinc compound is preferably zinc oxide added in an amount corresponding to from about 10 to about 30% stoichiometric excess. Where the reaction is carried to substantial completion, such amount results in highly suitable zinc carboxylate solutions having essentially no free fatty acid and having effective reinforcing amounts of zinc oxide.

The reaction is preferably continued (by maintaining the reaction conditions, including continual stirring and reaction temperature) for a sufficient period of time such that there is obtained at least 95% conversion of the carboxylic acid, and more preferably at least 97% conversion thereof. Where (as generally preferred) the zinc compound is employed in an amount from the stoichiometric amount to a 5% stoichiometric excess, the resulting solutions typically have increased clarity and storage stability. A reaction time of from about 0.5 hour to about 10 hours or more may be used. Generally, the reaction is substantially complete within 0.5 to 3.5 hours. In the case of polyether polyamines such as Jeffamine D-23Q and Jeffamine T-403 and using zinc oxide with hydrogenated tallow acid containing approximately 65% stearic acid and 35% palmitic acid, reaction can be substantially complete within 0.5 to 1.0 hour.

Completion of the reaction can readily be measured by analyzing the reaction mixture for free fatty acid. In general, the reaction is substantially and adequately complete when the extent of reaction is such that the free fatty acid content has decreased to 4% or less, based on the total weight

10 of the zinc compound and carboxylic acid employed.

The zinc compound and the carboxylic acid may be added in any suitable amounts in preparing the reaction mixture. There are no known lower limits on these amounts.

,_ In general, these amounts are limited on the upper end only by the power required to stir the reaction mixture. However, in order to obviate the need for removing from the resulting solution any amount of zinc carboxylate soap in excess of the amount dissolved in the amine, if necessary it is preferable-

20 to employ reduced upper limits on the zinc compound and the carboxylic acid. Such reduced limits (i.e., reduced below the power-constraint limits where necessary) are the amount of zinc compound and amount of acid corresponding, at approximately 100% conversion of each to the zinc carboxylate

25 soap, to the soap-amine solubility (i.e. the maximum amount of soap which is soluble in the amine) at the reaction temperature employed. If it is desired to cool the resulting solution to a storage or use temperature which is lower than the reaction temperature, the amounts of zinc compound and

30 acid will ordinarily be lower and correspond to the soap-amine solubility at such lower temperature. ι 5 unless an interfering upper limit results from the above-mentioned considerations, the amounts of zinc compound and carboxylic acid preferably correspond to about 10 to 90% soap based on the weight of the resulting solution and more preferably about 20 to 80%.

In a preferred class, the solution contains zinc carboxylate soap in a polyether polyamine selected from the group consisting of polyoxypropylene diamine and polyoxypropylene triamine having molecular weight of about 20 to about 5,000, preferably about 200 to about 3,000 and more preferably about 200 to about 800. In such preferred class, the zinc carboxylate is preferably zinc stearate and, more preferably, a mixture of about 65% zinc stearate and about 35% zinc palmitate, preferably in a soap concentration of about 50% based on the weight of the solution.

Water forms during the carboxylate-forming reaction of zinc compound and carboxylic acid. Where the zinc compound is zinc oxide or zinc carbonate, 1 mole of water is formed per mole of carboxylate soap. Zinc hydroxide results in formation of 2 moles of water per mole of soap. Zinc carbonate additionally results in formation of 1 mole of carbon dioxide per mole of soap. If the reaction is effected with zinc carbonate in a vented system, the carbon dioxide typically is removed by venting from the reaction mixture during the course of the reaction.

Water has a deleterious effect on the stability of the amine solution of zinc carboxylate. However, minor amounts of water may be tolerated. Water is removed to an extent such that water is not present in the solution in an amount more than 0.5% by weight, preferably not more than 0.3% by weight, and, more preferably, not more than 0.1% by weight.

Water can be removed from the reaction vessel during the course of the reaction and/or after the reaction is terminated. Preferably, water is removed after termination of the reaction by subjecting the reaction mixture to a vacuum, preferably at an absolute pressure of 5 pounds per square inch or less.

The resulting solution can be used or stored at the temperature of the reaction system after removal of water (typically 1-5°C below the final reaction temperature.

Alternatively, the solution can be cooled as desired to lower temperature, for example 20-22°C. If the amount of dissolved zinc carboxylate soap exceeds the solubility of the soap at such lower temperature, the excess amount of soap may be separated from the solution, as by centrifuging or filtration. Alternatively, the solution may be cooled only to its soap-saturation temperature and stored at such temperature. In some instances, typically where the melting point of the amine is above room temperature (i.e. 20-22°C) , cooling thereto results in solidifying the solution. Such solidified products may be used as solids, with or without size reduction, or reliquefied prior to use, preferably with stirring to redissolve any soap which may have precipitated.

Free fatty acid can be quantitatively determined by extraction thereof from the reaction mixture with acetone and titrating with sodium hydroxide.

As indicated above, water is unexpectedly not required as a component of the initial reaction mixture. / 7

Surprisingly, the reaction can be effectively carried out using an initial reaction mixture which is substantially free of water, i.e. a reaction mixture not containing more than 1% water, preferably not more than 0.1% water, for example totally free of water.

EXAMPLES

Practice of this invention is further illustrated by the following non-limiting examples. All parts, percents and other amounts throughout this disclosure are by weight unless otherwise indicated.

EXAMPLE 1

Bis-2-hydroxyethyl stearyl amine, 100 grams, having a melting point (M.P.) in the range of 50-55°C was charged to a reaction vessel equipped with an agitator, condenser set downward for distillation and a receiver and adapted for connection to a source of vacuum. The amine was heated to 71-74°C. While maintaining the resulting molten or liquid amine at such temperature, zinc oxide (14.4 grams, 0.178 gram-mole, 0.356 gram-equivalent; insoluble in the amine) was added with stirring. To the resulting substantially opaque liquid dispersion (solid zinc oxide dispersed throughout the molten or liquid amine) was added, with stirring, hydrogenated tallow fatty acid (containing approximately 65% by weight stearic acid and 35% by weight palmitic acid (89.8 grams, 0.325 gram-mole, melting at about 57-61°C). The resulting molten reaction mixture containing about 1.10 gram-equivalents of zinc oxide per gram-mole of the fatty acid was heated to a temperature of 90-97°C with continual stirring for a period of 3.5 hours, during which time the reaction mixture became a clear solution. Vacuum was applied to remove water. (Water forms during the carboxylate-forming reaction of the tallow acid and zinc oxide.) Based on method of preparation, the resulting solution consisted principally of a mixed solute

(zinc stearate and zinc palmitate) dissolved in bis-2-hydroxyethyl stearyl amine.

From the high clarity of the resulting solution, the reaction was judged to be substantially complete, i.e. the solution was judged to be substantially free of unreacted fatty acid.

While cooling to room temperature (approximately 20°C), the solution solidified. The resulting solid mixture was found to have a M.P. of 60°C. The solid was milled to form a white powder. The solution is useful as a combination antistatic agent and lubricating agent in polyolefins such as linear low-density polyethylene. The solution can be incorporated, in liquid or solid form, into polyolefins using well known procedures for mixing solids and/or liquids.

EXAMPLE 2

Polyoxypropylene diamine, a liquid at room temperature (about 20°C) having a molecular weight of approximately 400 (Jeffamine D-400, a primary amine terminated polyether available from Texaco Inc., 615 grams) was charged at 20-25°C to a reaction vessel equipped with an agitator, condenser set downward for distillation and a receiver and adapted for connection to a source of vacuum. At such temperature, zinc oxide (81 grams, 0.995 gram mole, 1.990 gram-equivalents; insoluble in the amine) was added with stirring. After heating the resulting substantially opaque liquid dispersion (solid zinc oxide dispersed throughout the liquid amine) to 160-170°F (about 71-77°C) there was added, with stirring, hydrogenated tallow fatty acid containing approximately 65% by weight stearic acid and 35% by weight palmitic acid (552 grams, 1.998 gram-moles, melting at about 57-61°C). The resulting molten reaction mixture containing about 0.996 gram-equivalent of zinc oxide per gram-mole of the fatty acid was heated to a temperature of 190-210°F (about 88-99°C) with continual stirring for a period of 0.5-1 hour, during which time the reaction mixture became a clear solution. Vacuum was applied to remove water. (Water forms during the carboxylate-forming reaction of the tallow acid and zinc oxide. )

Based on method of preparation, the resulting solution consisted principally of a mixed solute (zinc stearate and zinc palmitate) dissolved in Jeffamine D-400 amine terminated polyether. Analyses showed 1.4% free fatty acid in the solution (based on the weight of the solution) and a melting point of 123-125°C for the carboxylate (typical M.P. of commercial zinc stearate), and, accordingly, the soap constituted about 50% of the solution. Based on the amounts of added fatty acid and free fatty acid, calculation shows approximately 97% conversion of the fatty acid.

The solution, which was clear, liquid and stable at room temperature, is useful as an internal mold release agent mixture for producing polyurethane elastomer molding by the RIM process (e.g. the process described in Taylor et al., U.S. Patent 4,519,965) .

EXAMPLE

Polyoxypropylene triamine, a liquid at room temperature (about 20°C) having a molecular weight of approximately 400 (Jeffamine T-403, a primary amine terminated polyether available from Texaco Inc., 350 grams), was charged at 20-25°C to a reaction vessel equipped with an agitator, condenser set downward for distillation and a receiver and adapted for connection to a source of vacuum. At such temperature, zinc oxide (69.4 grams, 0.853 gram mole, 1.706 gram-equivalents; insoluble in the amine) was added with stirring. After heating the resulting substantially opaque liquid dispersion (solid zinc oxide dispersed throughout the liquid amine) to 60-80°C there was added, with stirring, hydrogenated tallow fatty acid containing approximately 65% by weight stearic acid and 35% by weight palmitic acid (475.4 grams, 1.721 gram-moles, melting at about 57-61°C). The resulting molten reaction mixture containing about 0.991 gram-equivalent of zinc oxide per gram-mole of the fatty acid was heated to a temperature of 90-98°C with continual stirring for a period of 1 hour, during which time the reaction mixture became a clear solution. Vacuum was applied to remove water. (Water forms during the carboxylate-forming reaction of the tallow acid and zinc oxide.)

Based on method of preparation, the resulting solution consisted principally of a mixed solute (zinc stearate and zinc palmitate) dissolved in Jeffamine T-403 amine terminated polyether. Analysis showed 1.6% free fatty acid in the solution (based on the total weight of the solution and, accordingly, the soap constituted about 60% of the solution. Based on the amounts of added fatty acid and free fatty acid, calculation shows approximately 97% conve-rsion of the fatty acid.

The solution, which was clear, liquid and stable at room temperature, is useful as an internal mold release agent mixture for producing polyurethene -elastomer molding by the

RIM process (e.g. the process described in Taylor et al., U.S.

Patent 4,519,965). The solution was placed in a glass container, which was then sealed with a cap. At the end of 8 weeks, the solution was still clear and free of precipitate, demonstrating its long-term storage stability.

EXAMPLE 4

Jeffamine D-400 polyoxypropylene diamine, a liquid at room temperature (about 20°C) having a molecular weight of approximately 400 (175 grams), and Jeffamine T-403 polyoxypropylene diamine, a liquid at room temperature having a molecular weight of approximately 400 (175 grams), were charged with stirring at 20-25°C to a reaction vessel equipped with an agitator, condenser set downward for distillation and a receiver and adapted for connection to a source of vacuum, thereby forming an amine mixture. At such temperature, zinc oxide (56.6 grams, 0.696 gram-mole, 1.392 gram-equivalents; insoluble in the amine mixture was added with stirring. After heating the resulting substantially opaque liquid dispersion (solid zinc oxide dispersed throughout the liquid amine mixture) to about 170°F (about 77°C) there was added, with stirring, hydrogenated tallow fatty acid containing approximately 65% by weight stearic acid and 35% by weight palmitic acid (387.4 grams, 1.404 gram-moles, melting at about 57-61°C). The resulting molten reaction mixture containing about 0.991 gram-equivalent of zinc oxide per gram-mole of the fatty acid was heated to a temperature of 220°F (about 114°C) with continual stirring for a period of about one hour, during which time the reaction mixture became a clear solution and water condensed on the walls of the vessel. Vacuum was applied to remove water.

Based on method of preparation, the resulting solution consisted principally of a mixed solute (zinc stearate and zinc palmitate) dissolved in a mixed polyoxypropylene diamine solvent (Jeffamine D-400 and Jeffamine T-403) amine terminated polyethers. Analysis showed less than 1.2% free fatty acid in the solution (based on the weight of the solution) and, accordingly, the soap constituted about 55% of the solution. Based on the amounts of added fatty acid and free fatty acid, calculation shows approximately 97% conversion of the fatty acid.

Although the solutions prepared in Examples 1-4 above were not chemically analyzed for the amount of water, if any, contained therein, experience has shown that the amount of water in solutions prepared by the procedures set forth therein is not more than 0.1%.

2,3 BEST MODE CONTEMPLATED

The best mode contemplated for carrying out this invention has been set forth in the above description, for example, by way of setting forth preferred materials and operating conditions, including but not limited to preferred ranges and values of amounts and other non-obvious variables material to successfully practicing the invention in the best way contemplated at the time of executing this patent application or, if sooner, at the time of filing the application.

It is understood that the foregoing detailed description is given merely by way of illustration and that many modifications may be made therein without departing from the spirit or scope of the present invention.

Claims

WHAT IS CLAIMED IS:

1. An in-situ reaction process for preparing a storage-stable plastics-processing solution comprising a zinc carboxylate soap dissolved in a plastics-processing amine, sai process comprising

(A) preparing a liquid reaction mixture comprising (a) an amine in liquid or molten state, (b) a zinc compound selected from the group consisting of zinc oxide, zinc hydroxide and zinc carbonate and (c) a carboxylic acid having from about 8 to about 22 carbon atoms, said zinc compound and 0 said carboxylic acid being dispersed throughout said amine,

(B) effecting reaction of said zinc compound with said carboxylic acid compound in said reaction mixture under saponification reaction conditions comprising (a) the temperature of said reaction mixture being from about 70°C to

-,5 about 120°C, (b) said reaction mixture being continually stirred, thereby preparing (i) a solution in said amine of the zinc carboxylate soap of said carboxylic acid and (ii) water o reaction, and

(C) removing sufficient amount of water such that 2o said solution contains not more than 0.5% by weight water.

2. The process of Claim 1 wherein said temperature is from about 80°C to 110°C.

3. The process of. Claim 2 wherein said temperature is from about 88°C to about 98°C.

4. The process of Claim 1 wherein said reaction mixture is initially substantially free of water.

5. The process of Claim 1 wherein said reaction conditions further include employing a ratio of at least 1 gram-equivalent of said zinc compound per gram-mole of said carboxylic acid.

6. The process of Claim 5 wherein the reaction is effected for a sufficient time such that at least 95% of said acid is converted to said soap.

7. The process of Claim 1 wherein said acid is selected from the group consisting of capric acid, lauric aci myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, abietic acid, isostearic acid, hydroxystearic acid, neodecanoic acid, oleic acid, linoleic acid, linolenic acid, n-octanoic acid, 2-ethyl-hexanoic acid, pelargonic acid and compatible mixtures of two or more of the foregoing acids.

8. The process of Claim 7 wherein said acid comprises stearic acid.

9. The process of Claim 7 wherein said acid is hydrogenated tallow acid comprising a mixture of stearic acid and palmitic acid.

10. The process for Claim 1 wherein said amine is selected from the group consisting of

(a) aliphatic^•.hydrocarbyl fatty primary amines represented by the formula RNH2 where R is a linear or branched, saturated or unsaturated aliphatic hydrocarbyl group having from about 10 to about 18 carbon atoms;

(b) tertiary amines represented by the formula R (R!)2 where R is as defined above and R¹ is 2-hydroxyeth l or 2-hydroxypropyl;

(c) diaminopropane-based diamines represented by the formula (R¹)2 -CH2CH2CH2- RR¹ where R is as defined above and Rl is 2-hydroxyethyl or 2-hydroxypropyl;

(d) polyoxypropylene diamine having molecular weigh from about 200 to about 5,000;

(e) polyoxypropylene triamine having molecular weight from about 200 to about 5,000;

(f) 1-(2-hydroxyeth 1)-2-(aliphatic hydrocarbyl)-2-imidazoline where the aliphatic hydrocarbyl group is a linear or branched, saturated or unsaturated structure containing from about 9 to about 17 carbon atoms;

(g) 1-(2-arαinoethyl)-2-(aliphatic hydrocarbyl)-2-imidazoline where the aliphatic hydrocarbyl group is a linear or branched, saturated or unsaturated structure containing from about 9 to about 17 carbon atoms, an the 2-aminoethyl group has the formula (R2)2 -CH2-CH2^_ where R ± _S H, a 2-hydroxyethyl group or a 2-hydroxypropyl group; and

(h) polyamine-based polyols containing zero, one, two or more alkoxy groups wherein the polyamine is aliphatic polyamine or toluene diamine. Z7

11. The process of Claim 10 wherein said amine is a polyoxypropylene diamine or triamine having molecular weight from about 200 to about 5000.

12. The process of Claim 11 wherein said amine is a mixture of polyoxypropylene diamines having an average molecular weight of about 400.

13. The process of Claim 11 wherein said amine is a mixture of polyoxypropylene triamines having an average molecular weight of about 403.

14. The process of Claim 13 wherein said triamines comprise 1,1,1-trimethylolpropane polyoxypropylene triamine.

15. The process of Claim 10 wherein said amine.is a tertiary amine represented by the formula RN(R )2 where R is as defined above and R! is 2-hydroxyethyl or 2-hydroxypropyl.

16. The process of Claim 15 wherein said tertiary amine is N,N-bis-2-hydroxyethyl stearyl amine.