US3269968A

US3269968A - Polymerization of unsaturated compounds with aromatized linoleic acid

Info

Publication number: US3269968A
Application number: US196435A
Authority: US
Inventors: Jr Malcolm E Hannah
Original assignee: Tenneco Chemicals Inc
Current assignee: Tenneco Chemicals Inc
Priority date: 1962-05-21
Filing date: 1962-05-21
Publication date: 1966-08-30
Anticipated expiration: 1983-08-30

Description

United States Patent 3,269,968 POLYMERIZATION 0F UNSATURATED COM- POUNDS WITH AROMATIZED LINOLEIC ACID Malcolm E. Hannah, Jr., Pensacola, Fla., assignor, by

mesne assignments, to Tenneco Chemicals Inc., a corporation of Delaware No Drawing. Filed May 21, 1962, Ser. No. 196,435 20 Claims. (Cl. 260-23.7)

This invention relates to an improved process for the emulsion polymerization of water insoluble, unsaturated organic compounds while dispersed in an aqueous medium. More particularly, the present invention relates to the use of a novel emulsifying agent in the emulsion polymerization reaction.

It is well known that unsaturated organic compounds containing the group, CH =C may be polymerized while dispersed in an aqueous medium. A large number of monomeric materials may be polymerized individually or in various combinations to form relatively large linear polymers. Such monomers include the aliphatic conjugated diolefins, or 1,3-butadiene compounds such as butadiene-1,3, 2,3-dimethyl-1,3-butadiene, isoprene, chloroprene, methylchloroprene, bromoprene and the like; the aryl olefins such as styrene, alpha-methyl-styrene, p-methyl alpha-methylstyrene, p-chlorostyrene and the like; as well as acrylic acid, methacrylic acid, methyl acrylate methyl methacrylate, butyl methacrylate, vinyl acetate, vinyl chloride, vinylidene chloride, and other unsaturated compounds of this type. Soaps of fatty acids and rosin acids have been used extensively as emulsifying agents for dispersing the monomeric material in the aqueous medium and forming oil-in-water type emulsion.

In general, the fatty acid soaps which have been used are the potassium or sodium soaps of higher fatty acids containing from 14 to 20 carbon atoms in the molecule such as myristic, palmitic, oleic, or stearic acid or mixtures thereof. The potassium soap of hydrogenated tallow fatty acids has been used extensively. This soap is primarily a mixture of the potassium salts of saturated fatty acids containing 14 to 18 carbon atoms per molecule. The potassium soap of hydrogenated tallow fatty acids does produce a relatively fast polymerization rate. These fatty acid soaps, particularly the hydrogenated tallow fatty acid soaps, are not sufficiently water-soluble and are quite diflicult to remove from the polymerization product which is an undesirable characteristic. The soaps of acids derived from many naturally occurring oils and fats as well as the soap of tall oil fatty acids cannot be used as the acids contain substantial amounts of polyunsaturated fatty acids which seriously interfere with the polymerization reaction. Soaps of polyunsaturated fatty acids slow down the rate of reaction and tend to react with material being polymerized. The presence of polyunsaturated acids in synthetic rubber interferes with curing the rubber.

In accordance with the present invention it has been found that the alkali metal salts of aromatized linoleic acid may be used to advantage as emulsifying agents for the polymerization of the aforesaid unsaturated organic compounds. The aromatized linoleic acid soap may be used alone or in combination with soaps of other fatty acids containing 14 to 20 carbon atoms. An important practical advantage is that tall oil fatty acids, and fatty acid mixtures derived from siccative oils, as well as other fatty acid mixtures containing polyunsaturated acids can be used in the production of soaps for the aqueous polymerization process after aromatization of the linoleic acid and/ or other polyunsaturated acids. The resulting fatty acid mixtures will usually contain at least by weight of the aromatized linoleic acid and at least 2 5% by weight of oleic. The presence of some oleic acid is desirable, however, oleic acid need not be present. The mixture of ice acids should contain less than 5% by weight of polyunsaturated fatty acids which are acids containing more than one carbon to carbon double bond. Soaps of aromatized linoleic acid or mixtures of this acid and other fatty acids may be used to obtain polymerization rates equal to that obtained with hydrogenated tallow fatty acid soaps. In addition the aromatized linoleic acid soaps can be used with rosin soaps as emulsifying agents in the production of synthetic rubber or other copolymers or homopolymers to produce results as good as those obtained with a mixture of hydrogenated tallow fatty acid soap and rosin soap. The rosin soap may be the alkali soap of rosin, either modified or unmodified, or of tall oil rosin acids, preferably, but not necessarily, disproportioned tall oil rosin acids.

The aromatized linoleic acid may be prepared by the aromatization of substantially pure linoleic acid or by aromatization of the linoleic acid when mixed with other fatty acids as is the case with acids derived from oils such as soybean, sunflower, peanut and fish oils, or the like. Tall oil fatty acids may be used to advantage as a starting material. Aromatized linoleic acid is a mixture of acids having a characteristic and strong infrared absorption band in the 13.3 region and having the following structural formula:

in which the sum of x and y is equal to 10 and y is at least 5 and less than 8. The aromatized linoleic acid may be prepared by any suitable process and may be prepared, for example, as described in the article entitled The Aromatization of Linoleic Acid With Palladium Catalyst appearing in The Journal of The American Oil Chemists Society, volume 33, No. 12, December 1956, pages 609 through 614.

The emulsion polymerization of the monomeric material may be carried out with the present soaps in the same manner as when the heretofore known soaps have been used and a batch-type, semi-continuous or continuous process may be used. Generally, various additives Will be used to promote the reaction, control the chain length of the polymer, and produce a polymer having the desired properties. The additives used vary depending upon the monomer being polymerized and other factors. For example, in the copolymerization of butadiene-1,3 and styrene to produce synthetic rubber, the emulsion also may contain, in addition to the soap, a modifying agent such as an alkyl mercaptan, an activator such as an alkali metal pyrophosphate-ferrous salt composition, a peroxide-type catalyst such as diisopropylbenzene hydroperoxide. As is well known additives may be present for other purposes and the above-mentioned additives may be replaced with other compounds.

In the following examples all parts are by Weight. Reference is made in these examples to use of the various soaps as an emulsifier in a synthetic rubber recipe. This basic recipe was as follows:

Parts by weight Preferably, solutions of portions of these ingredients are prepared and then these solutions and the monomer are charged to the reactor in the desired order. In the following examples, an aqueous solution of the soap and potassium chloride was prepared and adjusted to a pH value in the range of 10.5-10.8 with potassium hydroxide. An activator solution was prepared by combining aqueous solutions of the ferrous sulphate and potassium pyrophosphate. The combined solutions were heated to 60 C., held at this temperature for ten minutes and then allowed to cool to room temperature. The mercaptan and the hydroperoxide were dissolved in separate portions of the styrene. The soap solution, the styrene-mercaptan solution, the activator solution, and the butadiene were charged to the reactor in the order named. The reactor contents were agitated for minutes and then the hydroperoxide-styrene solution was added. The timing of the reaction was started at this time and the reactor contents were agitated while maintained at about 41 F. Samples were taken periodically and the percentage conversion of monomers to polymers calculated.

Example 1 Two polymerization runs were made utilizing the ironpyrophosphate recipe previously described. In one run, the soap was the potassium soap of refined tall oil fatty acids in which substantially all of the linoleic acid had been aromatized. These acids had the following characteristics. Analysis was by vapor chromatography.

Acids: Percent Below C18 saturated 0.4 C18 saturated 6.6

C18 one double bond 75.0 C19 saturated 4.3 C18 two double bonds 3.2 Aromatized linoleic acid 10.5

Note: C18 means a fatty acid containing eighteen carbon atoms in the molecule.

Properties Acid number 196 Iodine number 80 Titer, degrees centigrade 28 In the second run the emulsifier was the potassium soap of a commercial grade of oleic acid. In 4% hours the conversion with oleic acid soap as the emulsifier was 45%, whereas, the conversion was 62.5% in the same period with the soap of the fatty acids containing the aromatized linoleic acid.

Example 2 Two polymerization runs were made and in one the soap was the potassium soap of a mixture in equal amounts of disproportioned tall oil rosin and the aromatized tall oil fatty acids of Example 1. In the second run the emulsifier was the potassium soap of a mixture in equal amounts of disproportioned rosin and hydrogenated tallow fatty acids. In the first run containing the soap of aromatized linoleic acid the conversion was 62.9% in 4% hours as compared to a conversion of 59.4% in the second run containing the soap of hydrogenated tallow fatty acid.

Example 3 The emulsifier used in this run was the potassium soap of a mixture of fatty acids containing aromatized linoleic acid. The fatty acid mixture prior to aromatiz-ation was a tall oil fatty acid fraction containing 14% unsaponifiable material, about 40% fatty acids similar to pah'nitic acid, and substantial amounts of oleic acid and linoleic acid. The original acid mixture had an acid number of 178 and an iodine value of 95. Aromatization of the linoleic acid reduced the iodine value to 51. A 60% conversion was obtained in 4 hours.

' 4- Example 4 Aqueous solutions containing 3% of the potassium soaps of different fatty acids were prepared and then gradually cooled and the temperature noted at which the soaps deposited on the cooling coils (plate out temperature). Thereafter, the solutions were gradually warmed to determine the temperature at which the soaps redissolved. The following results were obtained:

In the freeze-coagulation latex process oleic acid soaps have been used in the past instead of hydrogenated tallow fatty acid soap as the oleic acid soap redissolves at a lower temperature and can be removed readily from the coagulated rubber by washing. The freeze-coagulation process is used, for example, in the production of neoprene where the polychloroprene latex is coagulated in a film on a freeze drum and the coagulum removed and washed. The soaps of the present invention readily redissolve at low temperatures and can be used in place of oleic acid soaps, with or without rosin soaps, in such a freeze-coagulation process or in any other emulsion polymerization process which is carried out at relatively low temperatures.

I claim:

1. In the production of linear polymers by polymerization of a water insoluble, unsaturated organic compound containing a CH =C group while dispersed in an aqueous medium in the presence of an emulsifying agent under polymerization conditions, the improvement which comprises incorporating in said aqueous medium prior to polymerization as an emulsifying agent an alkali metal salt of aromatized linoleic acid, said alkali metal being selected from the group consisting of sodium and potassium, and said aromatized linoleic acid being represented by the formula:

(CH CH (CH2) yC O OH wherein y represents a whole number of at least 5 and less than 8 and x is equal to 10y.

2. In the production of linear polymers by polymerization of a water insoluble, unsaturated organic compound containing a CH =C group while dispersed in an aqueous medium in the presence of an emulsifying agent under polymerization conditions, the improvement which comprises incorporating in said aqueous medium prior to polymerization as an emulsifying agent an alkali metal salt of a mixture of acids comprising aromatized linoleic acid and fatty acid containing from 14 to 20 carbon atoms, said mixture containing at least 5% by weight of aromatized linoleic acid and being substantially free of polyunsaturated fatty acids, said alkali metal being selected from the group consisting of sodium and potassium, and said aromatized linoleic acid being represented by the formula:

wherein y represents a whole number of at least 5 and less than 8 and x is equal to 10-y.

3. In the production of linear polymers by polymerization of a water insoluble, unsaturated organic compound containing a CH =C group while dispersed in an aqueous medium in the presence of an emulsifying agent under polymerization conditions, the improvement which comprises incorporating in said aqueous medium prior to polymerization as an emulsifying agent an alkali metal salt of a mixture of acids comprising aromatized linoleic acid and fatty acid containing from 14 to 20 carbon atoms, said mixture containing at least 5% by weight of aromatized linoleic acid and at least 25% by weight of oleic acid, said mixture being substantially free of polyunsaturated fatty acids, said alkali metal being selected from the group consisting of sodium and potassium, and said aromatized linoleic acid being represented by the formula:

wherein y represents a whole number of at least 5 and less than 8 and x is equal to y.

4. In the production of linear polymers by polymerization of a water insoluble, unsaturated organic compound containing a CH =C group while dispersed in an aqueous medium in the presence of an emulsifying agent under polymerization conditions, theimprovement which comprises incorporating in said aqueous medium prior to polymerization as an emulsifying agent the potassium salt of aromatized linoleic acid, and said aromatized linoleic acid being represented by the formula:

wherein y represents a whole number of at least 5 and less than 8 and x is equal to 10--y.

5. In the production of linear polymers by polymerization of a water insoluble, unsaturated organic compound containing a CH =C group while dispersed in an aqueous medium in the presence of an emulsifying agent under polymerization conditions, the improvement which comprises incorporating in said aqueous medium prior to polymerization as an emulsifying agent the potassium salt of a mixture of acids comprising aromatized linoleic acid and fatty acid containing from 14 to carbon atoms, said mixture of acids containing at least 5% by weight of aromatized linoleic acid and being substantially free of polyunsaturated fatty acids, and said aromatized linoleic acid being represented by the formula:

wherein y represents a whole number of at least 5 and less than 8 and x is equal to 10y.

6. In the production of linear polymers by polymerization of a water insoluble, unsaturated organic compound containing a CH =C group while dispersed in an aqueous medium in the presence of an emulsifying agent under polymerization conditions, the improvement which comprises incorporating in said aqueous medium prior to polymerization as an emulsifying agent the potassium salt of a mixture of acids comprising aromatized linoleic acid and fatty acid containing from 14 to 20 carbon atoms, said mixture of acids containing at least 5% by weight of aromatized linoleic acid and at least by weight of oleic acid, said mixture of acids being substantially free of polyunsaturated fatty acids, and said aromatized linoleic acid being represented by the formula:

"(CHzhCH (OH2)yC O OH wherein y represents a whole number of at least 5 and less than 8 and x is equal to 10-3 7. In the production of linear polymers by polymerization of a water insoluble, unsaturated organic compound containing a CH =C group while dispersed in an aqueous medium in the presence of an emulsifying agent under polymerization conditions, the improvement which comprises incorporating in said aqueous medium prior to polymerization as an emulsifying agent the potassium salt of tall oil fatty acids containing at least 5% by weight of aromatized linoleic acid and containing less than 5% by weight of polyunsaturated fatty acids, and said aromatized linoleic acid being represented by the formula:

(CHQXCHa "(CHDyO O OH wherein y represents a whole number of at least 5 and less than 8 and x is equal to 10-y.

8. In the production of linear polymers by polymerization of a water insoluble, unsaturated organic compound containing a CH =C group while dispersed in an aqueous medium in the presence of an emulsifying agent under polymerization conditions, the improvement which comprises incorporating in said aqueous medium prior to polymerization emulsifying agents comprising (1) the alkali metal salt of aromatized linoleic acid, and (2) the alkali metal salt of disproportioned rosin, the alkali metal in each instance being selected from the group consisting of sodium and potassium, and said aromatized linoleic acid being represented by the formula:

9. In the polymerization of monomeric material comprising a butadiene-1,3, compound while dispersed in an aqueous medium in the presence of an emulsifying agent under polymerization conditions to produce synthetic rubber, the improvement which comprises incorporating in said aqueous medium prior to polymerization as an emulsifying agent an alkali metal salt of aromatized linoleic acid, said alkali metal being selected from the group consisting of sodium and potassium, and said aromatized linoleic acid being represented by the formula:

10. In the polymerization of monomeric material comprising a butadiene-1,3 compound while dispersed in an aqueous medium in the presence of an emulsifying agent under polymerization conditions to produce synthetic rubber, the improvement which comprises incorporating in said aqueous medium prior to polymerization as an emulsifying agent an alkali metal salt of a mixture of acids comprising aromatized linoleic acid and fatty acid containing from 14 to 20 carbon atoms, said mixture containing at least 5% by weight of aromatized linoleic acid and being substantially free of polyunsaturated fatty acids, said alkali metal being selected from the group consisting of sodium and potassium, and said aromatized linoleic acid being represented by the formula:

11. In the polymerization of monomeric material comprising a butadiene-1,3 compound while dispersed in an aqueous medium in the presence of an emulsifying agent under polymerization conditions to produce synthetic rubber, the improvement which comprises incorporating in said aqueous medium prior to polymerization as an emulsifying agent the potassium salt of tall oil fatty acids containing at least by weight of aromatized linoleic acid and containing less than 5% by weight of polyunsaturated fatty acids, and said aromatized linoleic acid being represented by the formula:

wherein y represents a whole number of at least 5 and less than 8 and x is equal to -y.

12. In the polymerization of monomeric material comprising a butadiene-l,3 compound while dispersed in an aqueous medium in the presence of an emulsifying agent under polymerization conditions to produce synthetic rubher, the improvement which comprises incorporating in said aqueous medium prior to polymerization emulsifying agents comprising 1) the alkali metal salt of aromatized linoleic acid, and (2) the alkali metal salt of disproportionated rosin, the alkali metal in each instance being selected from the group consisting of sodium and potassium, and said aromatized linoleic acid being represented by the formula:

wherein y represents a whole number of at least 5 and less than 8 and x is equal to 10- 13. In the polymerization of butadiene-1,3 and styrene while dispersed in an aqueous medium in the presence of an emulsifying agent under polymerization conditions to produce synthetic rubber, the improvement which comprises incorporating in said aqueous medium prior to polymerization as an emulsifying agent an alkali metal salt of aromatized linoleic acid, said alkali metal being selected from the group consisting of sodium and potassium, and said aromatized linoleic acid being represented by the formula:

14. In the polymerization of butadiene-l,3 and styrene while dispersed in an aqueous medium in the presence of an emulsifying agent under polymerization conditions to produce synthetic rubber, the improvement which comprises incorporating in said aqueous medium prior to polymerization as an emulsifying agent an alkali metal salt of a mixture of acids comprising aromatized linoleic acid and fatty acid containing from 14 to carbon atoms, said mixture containing at least 5% by weight of aromatized linoleic acid and at least by weight of oleic acid, said mixture being substantially free of polyunsaturated fatty acids, said alkali metal being selected from the group consisting of sodium and potassium, and said aromatized linoleic acid being represented by the formula:

(CHz)xCH "(CHM wherein y represents a whole number of at least 5 and less than 8 and x is equal to 10-y.

16. In the polymerization of butadiene-1,3 and styrene while dispersed in an aqueous medium in the presence of an emulsifying agent under polymerization conditions to produce synthetic rubber, the improvement which comprises incorporating in said aqueous medium prior to polymerization emulsifying agents comprising (1) the alkali metal salt of aromatized linoleic acid, and (2) the alkali metal salt of disproportionated rosin, the alkali metal in each instance being selected from the group consisting of sodium and potassium, and said aromatized linoleic acid being represented by the formula:

17. In the polymerization of chloroprene while dispersed in an aqueous medium in the presence of an emulsifying agent under polymerization conditions to produce polychloroprene, the improvement which comprises incorporating in said aqueous medium prior to polymerization as an emulsifying agent an alkali metal salt of aromatized linoleic acid, said alkali metal being selected from the group consisting of sodium and potassium, and said aromatized linoleic acid being represented by the formula:

wherein y represents a whole number of at least 5 and less than 8 and x is equal to 10- 18. In the polymerization of chloroprene while dispersed in an aqueous medium in the presence of an emulsifying agent under polymerization conditions to produce polychloroprene, the improvement which comprises incorporating in said aqueous medium prior to polymerization as an emulsifying agent an alkali metal salt of a mixture of acids comprising aromatized linoleic acid and fatty acid containing from 14 to 20 carbon atoms, said mixture containing at least 5% by Weight of aromatized linoleic acid and at least 25 by weight of oleic acid, said mixture being substantially free of polyunsaturated fatty acids, said alkali metal being selected from the group consisting of sodium and postassium, and said aromatized linoleic acid being represented by the formula:

(CHDyC O OH wherein y represents a whole number of at least 5 and less than 8 and x is equal to 10-y.

19. In the polymerization of chloroprene while dispersed in an aqueous medium in the presence of an emulsifying agent under polymerization conditions to produce polychloroprene, the improvement which comprises incorporating in said aqueous medium prior to polymerization as an emulsifying agent the potassium salt of tall oil fatty acids containing at least by weight of aromatized linoleic acid and containing less than 5% by weight of polyunsaturated fatty acids, and said aromatized linoleic acid being represented by the formula:

(C 2) x C a um and potassium, and said aromatized linoleic acid being represented by the formula:

References Cited by the Examiner UNITED STATES PATENTS 3/1959 Miller et a1. 26023.7

OTHER REFERENCES Floyd et al.: The Aromatization of Linoleic Acid With Palladium Catalyst, The Journal of the American Oil Chemists Society, vol. 33, No. 12, December 1956, pp. 609-614.

LEON I. BERCOVITZ, Primary Examiner. DONALD E. CZAJA, Examiner.

J. J. KLOCKO, Assistant Examiner.

Claims

1. IN THE PRODUCTION OF LINEAR POLYMERS BY POLYMERIZATION OF A WATER ISOLUBLE, UNSATURATED ORGANIC COMPOUND CONTAINING A CH2=C< GROUP WHILE DISPERSED IN AN AQUEOUS MEDIUM IN THE PRESENCE OF AN EMULSIFYING AGENT UNDER POLYMERIZATION CONDITIONS, THE IMPROVEMENT WHICH COMPRISES INCORPORATING IN SAID AQUEOUS MEDIUM PRIOR TO POLYMERIZATION AS AN EMULSIFYING AGENT AN ALKALI METAL SALT OF AROMATIZED LINOLEIC ACID, SAID ALKALI METAL BEING SELECTED FROM THE GROUP CONSISTING OF SODIUM AND POTASSIUM, AND SAID AROMATIZED LINOLEIC ACID BEING REPRESENTED BY THE FORMULA: