CA1274057A

CA1274057A - Quick setting anionic bituminous emulsions

Info

Publication number: CA1274057A
Application number: CA000518197A
Authority: CA
Inventors: Alan Russell
Original assignee: JETCO CHEMICALS Inc
Current assignee: JETCO CHEMICALS Inc
Priority date: 1985-09-16
Filing date: 1986-09-15
Publication date: 1990-09-18
Anticipated expiration: 2007-09-18
Also published as: MX168349B; PH23056A; JPS62121766A; AU579078B2; US4657595A; AU6266086A

Abstract

QUICK SETTING ANIONIC BITUMINOUS EMULSIONS

ABSTRACT

Quick setting anionic bituminous emulsions in which the emulsifier is an alkylbenzenesulfonic acid which has been neu-tralized with specified alkyl or hydroxyalkyl amines.

Description

~2 ~4057 QUICK SETTIN~ ANIONIC BITUMINOUS EMULSIONS

Alan i~ussell FIELD OF_THE INVENTION
The invention pertains to anionic oil-in-water emulsions of bitumen which are useful as pavement sealers, roofing dressings, wood dressings, and the like.
BACKGROUND OF THE INVENTION
The ever-increasing traffic and heavy wear to which pave-ments are exposed, aggravates the need for a rapid and efficient means for sealing the pavement to provide a long wearin~3 surface .
Bituminous emulsions utilizing anionic emulsifiers have been widely used to seal pavemants, but have been deficient in requir-ing a relatively long setting-time before they hardened to a useful surface. These anionic emulsions set by evaporation. Therefore, the time for setting will greatly vary depending on the tempera-ture and humidity, as well as other environmental factors. In addition, the freshly applied emulsions are particularly susceptible to rain. If they have not hardened to a cohesive surface, a rainstorm will rapidly wash away or seriously damage the surface seal. Because of this deficiency of anionic bituminous emulsions, the prior art has sought means to shorten the setting time of such emulsions.
It is also desirable to incorporate synthetic latex polymers into bitum~nous emuls70ns in order to improve the durability of the coating which is produced and to increase the resistance of the coating to the effects of ~emperature.
U.S. Pat. No. 4,t93,816 Ferm, issued Mar. 18, 1980, dis-closes quick-setting anionic bituminous emulsions in which the quick setting property is obtained by adding lime to the emulsion just prior to application to the pavement. The emulsifiers dis-closed In said patent include salts of hydrocarbon sulfonic acids wherein the salt-forming cation ca~l be an alkali metal, ammonium ~.J`;~

~2~

or substitu~ed ammonium ion. The emulsions have a pH above 7 and can contain a synthetic rubber latex.
It is an object of the present invention to provide quick setting anionic bituminous emulsions which do not require the 5 incorporation of an additive just prior to use. It is a further objective of the invention to provide quick setting bituminous emulsions which contain a synthetic rubber latex.
SUMMARY OF THE INVENTION
The present invention is directed to quick-setting bituminous 10 emulsion compositions wherein amine and alkalonamine salts of alkylbenzenesulfonic acids are used as the emulsifiers. Preferred compositions are those wherein the alkanolamine salts are used as - the emulsifier, the pH is from about 2.5 to about 6.9 and whereinthe compositions contain a chloroprene-methacrylic acid synthetic rubber latex.
DETAILED DESCRIPTION ~)F THE INVENTION
In accordance with the present invention it has been found that bituminous emulsion compositions which utilize amine and alkanolamine salts of alkylben2ene sulfonates as the emulsifiers exhibit quick setting properties, and therefore are especially suitable for use as pavement ciressings. It has been found that these emulsions "break" quickly when applied to the pavement surface .
The term "quick setting" as used herein means that the aciueous emulslon will coagulate more than 2% when tested in accordance with the AST~I D-~4, cement mixing test.
Breaking of the emulsion results in migration of the water to the surface of the coating (where it forms into droplets and evaporates) and in setting of the bituminous coating. This is in contrast to typical anionic slow setting bituminous emulsion com-positions which depend upon homogeneous evaporation for removal of water and setting of the coating. Homogeneous evaporation inherently results in slow setting of the coating, especially so under conditions of low temperature and high humidity.
The bituminous emulsion compositions of the present inven-tion comprise:

a) from about 50% to about 70% by weight of a non-coal tar bitumen;
b) from about 0.1~6 to about 3% by weight of an emulsifier which is the amine salt of an alkylbenzene sulfonic acid in which the alky! contains from about 8 to about 16 carbon atoms and wherein the salt-forming amine is selected from amines having the formula:

1~ ' R 2 ~ N - R3 wherein R1 is an aminoalkyl or monohydroxyalkyl radical containing from 1 to about 6 carbon atoms and R~ and R3 are each selected from the group consisting of hydrogen, alkyl, aminoalkyl and monohydroxyalkyl radicais containing from 1 to about 6 carbon atoms; and c) from about 30% to about 50% water.
All percentages and proportions herein are "by weight"
20 unless specified otherwise.
The bitumens used in the compositions herein can be any of the bitumens commonly used in pavement or roofing emulsion dressings. Examples are asphalt, asphalt cut-backs and pitch.
Coal tar bitumens are not suitable for use in the invention. The 25 invention will be illustrated herein, using asphalt.
The emulsifiers used in the compositions of the invention are amine salts of alkylbenezenesulfonic acids, ~

wherein R is an alkyl group (linear or branched) containing from about 8 to about 16 (preferably from about 10 tG about 14) carbon atoms. Th~ neutralizing amlne from whlch the salt i5 formed is a primary, secondary or tertlary amine of the formula:

~,7~ 7 ~2 ~ N - R3 wherein Rl is an` amino alkyl or monohydroxyalkyl radical con-taining from 1 to about 6 carbon atoms and R2 and R3 are each selected from the group consisting of hydrogen, alkyl, aminoalkyl and monohydroxyalkyl radicals containing from 1 to about 6 carbon atoms. Examples o~ the said amines are ethylenediamine, diethylenetriamine, triethylenetetraamine aminoethylpiperazine, aminoethylethanolamine, ethanolamine, methylethanolamine, dieth~
anolamine, triethanolamine, trimethylolamine, dimethylathanolamine.
The amine salts herein are 1: 1 molar ratio salts of alkylbenzene sulfonic acid and amine, i.e., even if the amine contains more than one reactive amino group, the salt is one wherein only one amino group has been reacted with the alkylbenzene sulfonic acid.
This is achieved by using at least one mole of amine per mole of acid when preparing the salt.
The emulsions can be prepared by known techniques for preparing bituminous emulsions, e~g., using a colloid mill.
The emulsions herein should be formulated to have a pH of from about 2 . 5 to about 10 . The pH can be adjusted to any desired level within this range with acid ~e.g., HCIl or base ~ e . ~ ., NaOi~ ) .
A particularly desirable optional component of the emulsion compositions herein is a synthetic latex rubber polymer. The latex po!ymer makes the surface coating produced by the compo-sition less susceptible to temperature extremes, and increases the toughness and tenacity of the coating and may provide resistance to the deterioration caused by oxidation and ultraviolet radiation.
The latex polymers are aqueous suspensions of synthetic rubber. Examples of latex polymers are the following:
1. The family of SBR latices whlch are the emulsion copolymers 3S of styrene and butadiene monomers. Typically, the styrene content varies from ~0~ ta 309~, and the butadiene content - ~;27~57 varies from 70% to 80% and such latices are manufactured in a resin acid soap. There are specific products available from several manufacturers (for example, PolysarR Latex from Polysar Incorporated which contains approximately 30%
water, 5% resin acid soap, and 6596 polymer which is the copolymer of styrene and butadiene in the ratio of 30 to 7û;
and Latex Ultrapave-70R from Textile Rubber ~ Chemical - Co., which contains approximately 3096 water, 5% resin acid soap, and 65% polymer which is the copolymer of styrene and butadiene). These have been widely marketed as additives for paving applications.

2. The Neoprene homopolymer latices which are homopolymers ofchloroprene, usually manufactured in resin acid soaps.
Neoprene latices are particularly useful in paving appli-cations because they are vulcanized by various mechanisms including sulfur and metallic oxides and resist oxidation and solvent action. A typical Neoprene homopolymer contains 40%
to 50% water, 5% to 10~ resin soap and 40% to 55% polymer.
An example is NeopreneR Latex 671 A from E. I . duPont de Nemours ~ Co., Inc.

3. Neoprene latex copolymer which Is a copolymer of chloro-prene and methacrylic acid. A typical product of this type is NeopreneR Latex 115 from duPont Company, which con-tains 50% to 5596 water~ approximately 1% of a nonionic dis-persant, and 44% to 49% polymer which is approximately 95%
chloroprene and 5~ methacrylic acid. This type of latex has available carboxylic acid groups in the polymer structure.
The presence of carboxylic acid structures allows for vul-canization in the presence of bivalent or trivalent metallic ions (Ca++ or Fe+++ as examples) at low temperatures.
However, the presence of these same carboxylic acid struc-tures precludes the use of this latex in a caustic medium.

When latex polymers are used in bituminous emulsion compo-sitions, -they are generally used in concentrations (based on S~j1 weight of latex solids) of less than 2.5% for pavement sealing applications, and more than 2 . 5% for elastic coating applications.
Therefore, depending upon application, the latex content of the emulsions herein may be as little as 0.25% to as high as 70~6 latex solicls by weight of the bituminous emulsion.
When the latex polymer used is the chloroprene-methacrylic acid copolymer previously described, it is preferable that the emulsion be formulated at an acid pH, pre~erably within the range from 2.5 to 6.9, most preferably from about 4.5 to about 5.5.
10 This assures that the acid groups in the copolymer remain in the acid form .
When formul2ting in the acid pH range, it is preferable that the salt-forming amine for the emulsifier be an alkanolamine, i.e., at least one of the R1, R2 and R3 radicals in the salt-forming 15 amine is a hydroxyalkyl group, e.g,, monoethanolamine, methyldi-ethanolamine or triethanolamine. The alkanolamine salts are superior to other amine salts (and metallic salts) of alkylbenzene sulfonates for formulating bituminous emulsion of acid pH.
Typically, the emulsions herein will have particulate materials 20 (aggregates) added to them to form slurries, e.g., slurry seals for pavements. The aggregates provide durability, hardness, etc., to the coating formed with the emulsion composition.
Depending upon the ultima$e use of the slurry, a variety of aggregates may be employed. Suitable materials include rubber 25 buffings, cut fibers, such as those of bagasse, hemp, organic polymeric fibers, made from polypropylene, polyesters, poly-amides, and mineral aggregates, such as gravel, crushed lava, crushed granite, crushed limestone, sand, clay, etc.
The particle size of the aggregate will vary depending upon 30 the particular use. The particles may range from about 1 micron or less to about 1 inch or greater. Mixtures containing a large variation of particle sizes are suitable in particular uses.
However, when mineral aggregates are used in the slurry seals, the particle size will be that within the ranges normally specified 35 for slurry seals. See the Asphalt Handbook, Revised Edition, the Asphalt Institute, College Park, Maryland, Sept. 1~60, pages ~0 5~7 and 216-21~. Normally, the aggregates for slurry seals are of a particle si~e in the range of from about 4 to abou~ 200 mesh, U.S. Standard sieve. Usually, the aggregate will be siliceous or calcareous, illustrated by fine sand, crusher dust, crushed 5 granite, etc.
In slurries, the bitumen emulsion will be present in from about 3 to 150 parts, more usually from about 5 to 100 parts, and preferably from about 10 to 30 parts based on 100 parts of aggregate. In slurry seals for pavements, the emulsion will normally be present in from about 15 to ~5 parts per 100 parts of aggregate. The emulsion will normally have from about 50 to 70 weight percent, more usually from about 55 to 65 weight percent of bitumen. Any of the paving-type asphalts available in com-merce will lend itself as a suitable bitumen. In slurry seals, 15 preferred paving bitumens usually have a penetration at 77~ of from about 40 to 110, The emulsifier will be present in the emulsion at from about 0.1% to 3%, and preferably from about 0.25~ to about 0.75~ by weight of the emulsion. Other additives may also be present, their amounts varying from about 0.05 to 3 weight percer,t of the emulsions. The remainder of the emulsion will be water, varying usually from about 25 to 49.9 weight percent .
Included among the other additives which may be present are bentonite,- alkali metal salts of phenol sulfonate, and, as dis-25 cussed supra, latex polymers.
In preparing slurry seals, conventional slurry seal equipmentmay be used, as exemplified in U.S. Pat. Re. 26,204, Young, granted May 16, 1967. Means are providecl for mixing the bitu-men emulsion and aggregate so as to provide a fairly homogeneous 30 mixture. The mixing normally rec~uires from about 0. 5 to 5 minutes, more usually from about 1 to 3 minutes.
The bituminous emulsions of the inventions can optionally contain from about 0.0025% to about 1% of a surface active cationic quaternary ammonium salt containing at least one 8 to 24 carbon 35 atom alkyl group in its structure. These cationic salts promote 7 4 ~3 5 ~

adhesion to the surfaca to which the emulsion is applied. Exam-ples of suitable cationic surfactants are quaternary ammonium salts corresponding to the forrnulas:
R5 +

_ R7 0 and ~5 R6 ~+
R4 - N ~ ~CH2)n ~ N ~8 2X

_ R7 Rg wherein R" is an alkyl group containing from 8 to about 24 ~pref-erably about 12 to about 22 carbon atoms); R5, R6, R7, R8 and Rg are selected from the group consisting of alkyl and monohy-droxyalkyl radicals containing from 1 to about 3 carbon atoms, n is from 2 to 4 (preferably 3) and X is selected from the group consisting of monovalent radicals consisting of halide, methylsul-fate, nitrate and C1 to C5 carboxylic acid radicals. Specific exampl~s of these quaternary ammonium compounds are stearyltri-methyl ammonium chloride and N-stearyldimethyl-N'-trimethylethyl-enediamine dichloride.
If the emulsion is to be used in a slurry seal composition containing aggregates, it is preferred that these cationic materials, if used, not be formulated into the composition, but rather be dispersed in water and sprayed onto the pavement surface before application of the slurry seal. When spraying the catlonic material onto the pavement an application rate of from about 1 to about 10 g per sq. m of pavement is used.
The invention will be illustrated by the following i xamples.

~t7~35~

g EXAMPLE I
-An asphalt emulsifier compositlon is prepared mixing S0 parts dodecyl benzene sulfonic acid, 10 parts ethylene diamine, 20 parts water, and 20 parts diethylene glycol. The mixture is stirred in 5 a closed reactor which then cooled to remove the exo~herm. The mixture is an easily pourable liquid which can conveniently be used to prepare bituminous emulsions.
EXAMPLE I I
An asphalt emulsifier composition similar to that of Example 10 l l is prepared by substituting 15 parts diethylenetriamine for the 10 parts ethylenediamine used in Example 1, and 15 parts wat&r for the 20 parts water used in Example 1.
EXAMPLE l l I
- An asphalt emulsifier composition similar to that of Example I15 is prepared by substituting 20 parts of a commercially available ethyleneamine by-product which is 40% aminoethylpiperazine and 6096 nonlinear and linear tetramine which consists at least partlally of triethylenetetramine; and substantial amounts of "tris"
tetramine for the 10 parts ethylenediamine used in Example I and substituting 10 parts water for the 20 parts water used in Example 1.
EXAMPLE IV
An asphalt emulsifier composition similar to that of Example I
is prepared by substituting 10 parts monoethanolamine for the 10 25 parts ethylenediamine used in Example 1.
EXAMPLE V
_ An asphalt emulsion is prepared using conventional tech-nology consisting of 62 parts Gulf States AC-20 asphalt and one part of the emulsifier described in Example IV and 37 parts of 30 water. The emulsifier is dissolved Into the water and the solution is adjusted to a pH of approximately 5 . 5 with approximately 0 . 01 part of hydrochloric acid.
EXAMPLE Vl -A conventional slurry seal is prepared In a conventional 35 slurry seal machine consistlng of lQQ parts of type ll Joplin Chat aggregate, 12 parts of water, and 16 parts of the emulsion of ~ ~7~

Example V. Optional ingredients which can be added to this slurry are 0-1 part of a fine mineral filler and 0.05 part of Neoprene Latex 115.
EXAMPLE Vll s A driveway sealer is prepared by mixing approximately 32 parts of the emulsion in Example V with approximately one part of duPont NeopreneR Latex 115, and blending this mixture with appl~oximately 33 parts of graded #16 sieve sand, approximately 33 parts of clay slurry containing approximately 30% M~D Ball Clay, and approximately one part water that may contain up to 50%
tallowtrimethylarnmonium chloride quaternary. In practice, this product is manufactured in a ribbon blender with the ingredients added in the stated order. The mixture becomes a mechanicai suspension of coated aggregate particles upon continued mixing.
I n summary, this invention comprises the manufacture and use in asphalt emulsions of amine salts of alkylbenzene sulfonates where the neutralizing amine is chosen from the family of ethyl-eneamines or alkanolamines.
When the family of alkanolamines is chosen, the result is an asphalt emulsifier which is quick setting (failing the cement mixing test) anionic (producing negatively charged asphalt par-ticles) and acidic thaving a nominal pH of 5.5).
Both families of asphalt emuls3fiers dascribed herein are compatible with latices supplieà with anionic or nonionic soaps as the dispersion agent. But only the ethanolamine family of emul-sifiers is compatible with latices containing carboxylic groups (i.e., chloroprene/acrylic acid copolymers).

Claims

WHAT IS CLAIMED IS:

1. A bituminous emulsion comprising:
(a) from about 50% to about 70% by weight of non-coal tar bitumen;
(b) from about 0.1% to about 3% by weight of an emulsifier which is the amine salt of an alkylbenzene sulfonic acid in which the alkyl contains from about 8 to about 16 carbon atoms and wherein the salt-forming amine is selected from amines having the formula:

wherein R1 is selected from the group consisting of aminoalkyl and monohydroxyalkyl radicals containing from 1 to about 6 carbon atoms and R2 and R3 are each selected from the group consisting of hydrogen, alkyl, aminoalkyl and monohydroxyalkyl radicals containing from 1 to about 6 carbon atoms and wherein the molar ratio of alkylbenzene sulfonic acid to amine in the amine salt is 1:1; and (c) from about 30% to about 50% water, the said composition having a pH of from about 2.5 to about 10.

2. The composition of Claim 1 which additionally comprises from about 0.25% to about 70% of synthetic latex solids.

3. The composition of Claim 2 wherein the synthetic latex is a copolymer of chloroprene and methacrylic acid, wherein at least one of R1, R2 and R3 in the neutralizing amine is a hydroxyalkyl radical and wherein said emulsion has a pH of from about 2.5 to about 6.9.

4. The composition of Claim 1 in the form of an aggregate-containing slurry, the said slurry comprising from about 3 to about 150 parts of the emulsion of Claim 1 per 100 parts of aggregate, the said particulate aggregate having a particle size of from about 1 micron to about 1 inch.

S. The composition of Claim 4 wherein the particulate aggregate is a siliceous or calcareous mineral and has a particle size of from about 4 mesh to about 200 mesh.

6. The composition of Claim 2 in the form of an aggregate-containing slurry, the said slurry comprising from about 3 to about 150 parts of the emulsion of Claim 2 per 100 parts of particulate aggregate, the said particulate aggregate having a particle size of from about 1 micron to about 1 inch.

7. The composition of Claim 6 wherein the particulate aggregate is a siliceous or calcareous mineral and has a particle size of from about 4 mesh to about 200 mesh.

8. The composition of Claim 3 in the form of an aggregate-containing slurry, the said slurry comprising from about 3 to about 150 parts of the emulsion of Claim 3 per 100 parts of aggregate, the said particulate aggregate having a particle size of from about 1 micron to about 1 inch.

9. The composition of Claim 8 wherein the particulate aggregate is a sillceous or calcareous mineral and has a particle size of from about 4 mesh to about 200 mesh.

10. The composition of any of Claims 1, 2 or 3 which additionally contains from about 0.0025% to about 196 of an adhesion promoting agent which is a surface active quaternary ammonium salt having at least one 8 to 24 carbon atom alkyl group in its structure.

11. A method of sealing a pavement surface comprising the steps of:

1. applying to said pavement surface a coating of quat-ernary ammonium surface active agent having at least one 8 to 24 carbon atom alkyl group in its structure, the said coating being applied at a rate so as to provide from about 1 to about 10 grams of quaternary ammonium salt per square meter of pavement surface;
and

2. applying over the coating of Step (1) a coating of an aggregate-containing bituminous emulsion slurry comprising:
A. a bituminous emulsion comprising:
(a) from about 50% to about 70% by weight of non-coal tar bitumen;
(b) from about 0.1% to about 3% by weight of an emulsifier which is the amine salt of an alkyl-benzene sulfonic acid in which the alkyl contains from about 8 to about 16 carbon atoms and wherein the salt-forming amine is selected from amines having the formula:

wherein R1 is selected from the group con-sisting of aminoalkyl and monohydroxyalkyl radicals containing from 1 to about 6 carbon atoms and R2 and R3 are each selected from the group consisting of hydrogen, alkyl, aminoalkyl and monohydroxyalkyl radicals containing from 1 to about 6 carbon atoms and wherein the molar ratio of alkylbenzene sul-fonic acid to amine in the amine salt is 1:1;
and (c) from about 30% to about 50% water B. a particulate aggregate which is a siliceous or calcareous mineral having a particle size of from about 4 mesh to about 200 mesh;
the said slurry containing from about 3 to about 150 parts of A.
per 100 parts B.

RLH/rmj/A12-103