Patented June 17, 1952 2,600,414

UNITED STATES PATENT OFFICE vULCANIZATION OF ACRYLICRESINs William C. Mast, Philadelphia, Chessie E. Reh berg, Glenside, and Charles H. Fisher, Abing ton, Pa., assignors to the United States of AgricultureAmerica as represented by the Secretary of No Drawing. Application August 22, 1947, Serial No. 770,180 . 2 Claims. (CI. 260-63) (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757) 2 This application is made under the act of late, ethyl acrylate and of other normal alkyl March 3, 1883, as amended by the act of April 30, acrylates are soft and flexible: " Furthermore; it 1928, and the invention herein described, if pat is known that useful flexible materials can be ented, may be manufactured and used by or for made by blending alkyl acrylate polymers with the Government of the United States of America, 5 other materials or by incorporating fillers and for governmental purposes without the payment pigments into them. The resulting products, to us of any royalty thereon. however, lack some of the desirable characteris This application is a continuation-in-part of tics found in natural and in certain synthetic our application Serial No. 595,870, filed May 25, rubbers. . r - - - - ... - . . . - -- . . . ------1945, which has matured into Patent No. 2,492,- 0. Acrylic polymers and copolymers having ole 170. finic unsaturation, for instance polymerically This invention relates to synthetic rubbers acrylate, copolymers of acrylic esters with vinyl prepared from alkyl acrylate polymers and co beta-methyl crotonate, or with butadiene and polymers. related dienes yield rubberlike materials. As far In accordance with current practice, the terril 5 as is known, however, synthetic rubbers have not “synthetic rubber' is used herein to designate a been produced hitherto from saturated acrylic synthetic rubberlike material which, at ordinary polymers and copolymers. - if r2: temperature, can be stretched to at least twice A “synthetic rubber,' as previously defined, is its initial length, and will forcibly retract to sub not produced when alkyl acrylate polymers, such stantially its original dimensions within a reason 20 able time thereafter. as polymethyl acrylate and polyethyl acrylate are It is known that Synthetic rubbers can be pro heated with sulfur. We have attempte ani duced by Vulcanization of certain polymeric sub zation by heating such polymers conta stances. As in the treatment of natural rubber, fur and mixtures of such polymers, sulfur, cart vulcanization of these Synthetic polymers is a 25 black, and some of the standard accelerators used process whereby a thermoplastic, -soluble in the vulcanization of natural rubber, withou Substance of limited elasticity and high plastic successful results, and the products soc flow is converted to a highly elastic, insoluble ma-. lack many of the desirable properties found in terial, Substantially free of plastic flow proper vulcanized rubber and vulcanized - . . ties, and relatively insensitive to temperature 30 bers. ------... ', " . . . , , variations. - An object of this invention, accordingly, is to Heretofore the presence of olefinic unsatural produce vulcanized alkyl acrylate polymers hay tion in the polymeric chain was considered neces ing enhanced rubberlike properties and capable sary to render the polymeric material susceptible of being used in place of rubber. Another object of Vulcanization. Thus a number of Synthetic is to prepare alkyl acrylate polymers, which c rubbers are produced by vulcanization of unsat be compounded and milled on standard urated polymers formed either from butadiene rolls and equipment and cure : and related dienes or obtained by copolymeriza standard rubber molds to tion of monomer mixtures comprising at least one diene component. It is known that the polymers of methyl acry 2,600,414 3 4. natural rubber and some of the previously de venient procedure for preparing the copolymers, scribed Synthetic rubbers. A further object is to but these can also be made by solution or mass provide synthetic rubbers which can be made polymerization. Polymerization can be achieved from carbohydrates, an abundant and reproduc by the usual methods including the effect of ible raw material. A still further object is to pro photochemical action or heat polymerization. vide methods for copolymerizing methyl acrylate, Although polymerization can be conducted with ethyl acrylate, and Similar alkyl acrylates With out catalysts or initiators the addition of these various quantities of other monomers including greatly Speeds up the reaction. The presence of Substituted alkyl acrylates, to obtain essentially known polymerization regulators such as dodecyl saturated copolymers which can be vulcanized by 10 mercaptain, acrylonitrile, carbon tetrachloride, certain suitable agents which we have found to hexa-chloro ethane, trichloropropionitrile, or alkyl be effective. Other objects and advantages of Xanthogen disulfides like isopropyl xanthogen di the invention Will appear hereinafter. Sulfide has a beneficial effect, on the process, but We have found that Synthetic rubbers and rub Vulcanizable copolymers suitable for the produc berlike materials can be made by copolymerizing tion of Synthetic rubbers can be made without a mixture of from 80 to 98 percent, by weight, their use. of an alkyl acrylate, which includes alkyl acry The polymerization catalysts or initiators suit lates and alkacrylates such as methyl, ethyl, able for use in the production of the copolymers propyl, butyl, Octyl and other alkyl acrylates and of the present invention are, for example, oxidiz methacrylates, with at least 2 percent of either 20 ing agentS Such as hydrogen peroxide, benzoyl (a) monomers having only one polymerizable peroxide, Sodium perborate, ammonium persul double bond, such as aryl acrylates or methacry fate, urea-peroxide, percarbonates and other sim lates, as for example phenyl and benzyl acrylate, ilar Substances commonly utilized to initiate or phenyl methacrylate and so forth, or (b) mono promote polymerization reactions. mers having only one polymerizable double bond : When copolymerization is conducted in aque and in addition containing at least one halogen OuS emulsion various emulsifying and dispersing atom or a cyano or a ketone group. Compounds agentS can be used to effect dispersion of the of this type which are preferred are methyl vinyl monomers, improve the stability of the emulsion ketone, chloroallyl alcohol, such as 2-chloroally and reduce duration of the reaction. Suitable alcohol, and a chlorine-substituted con 30 agents include: anion active compounds, for ex taining not more than two chlorine atoms, such ample Sulfated compounds like sulfated oils such as 1-chloropropene, 2-chloropropene, and 2,3-di as Sulfated castor oil; Sulfated alcohols; or alkyl chloropropene. Other compounds of this type Sulfates such as sodium tetradecyl sulfate; sul which may be used include for example, chloro fonated compounds, like aliphatic sulfonates, for ethyl acrylate, cyanoethyl acrylate, methyl chlor- 3. example, the Sodium Salt of Sulfonated petroleum acrylate, vinyl bromopropionate, bromopropyl oil; Sulfonates of aromatic compounds which may methacrylate, bromoethyl acrylate, 3-chloro contain alkyl or other aliphatic side chains, for propyl acrylate, 1,3-dichloro-2-propyl acrylate, example, the Sodium salt of alkyl phenoxyethyl bromopropyl acrylate, 2-chloroallyl lactate, vinyl Sulfonate and of Similar aryl-alkyl sulfonates; idenechloride, vinyl chloride, allyl chloride, 2 cation active compounds like cetyl dimethyl chloroallyl pelargonate, 2,3-dichloropropyl acry benzyl annonium chloride and other well known late, di-n-butyl chloromaleate, alpha-chloroacry emulsifying and dispersing agents used either lonitrile, alpha-chlorostyrene, beta-chloroethoxy Singly or in combination in emulsion polymeriza ethyl acrylate, chloromaleic anhydride, dimethyl tion. chloromaleate, di-2-chloroethyl maleate, 2-chlo 45 The polymerizations can be carried out for ex roethyl-vinyl ether, and so forth. The resulting ample in a round-bottomed three-necked, Pyrex copolymers are then compounded with a vulcan glass flask fitted with a thermometer well, a re izing agent and preferably with other compound fiuX Condenser and a stirrer. The monomer mix ing ingredients used in the vulcanization of nat ture is added to water and an emulsifying agent ural rubber, and heated under conditions com 30 in the flask, stirred, and heated to about reflux monly utilized in the production of natural and ing temperature. The desired amount of catalyst Synthetic rubber vulcanizates. The vulcanization is then added either ail at once or by increments. process of this invention yields satisfactory re Heating is applied, if necessary, to maintain Sults when applied to copolymers obtained by gentle refluxing, and the course of the polymer polymerization of monomer mixtures containing 5 5 ization is followed by noting changes in the re an alkyl acrylate and a halogen, cyano- or ketone fluxing temperature. When refluxing ceases in group-containing-comonomer, in the proportion, spite of continued heating (usually at about 90 by Weight, of from 80 to 98 percent of the acry 95 C.) the polymerization is complete. The late to at least 2 percent, by weight, of the halo eimulsion can then be steam distilled to remove gen, cyano- or ketone-group-containing comono. 60 monomers and other volatile materials, is coagul lated by addition of a dilute solution of sodium le. chloride, and the polymeric material washed with Although olefinic unsaturation has usually been water and dried. considered necessary for vulcanization, the co Data on some polymerizations are given here polymers described herein are essentially satu in after in Tables I, X, and XIII. - - rated, but are vulcanizable by the agents and The alkyl acrylate copolymers so obtained can techniques of the present invention. It is ad be converted to synthetic rubbers by the action vantageous to Vulcanize saturated copolymers, of Vulcanizing agents, preferably used in con since cross-linkage usually occurs when unsatu junction with conventional rubber compounding rated copolymers are made by polymerizing such 70 ingredients, under conditions essentially analo monomers as butadiene, isoprene, ally fumarate, gous to those utilized in the production of natural divinylbenzene and the like. and Synthetic rubber Vulcanizates. Copolymerization can be effected by any meth The Vulcanizing agents suitable for use in Od Suitable for the production of alkyl acrylate effecting the vulcanization of the alkyl acrylate copolymers. Emulsion polymerization is a con 75 copolymers of the present invention include the

2,600,414 5 6 following classes of vulcanizing agents utilized rolls. The copolymers were tacky and required in the vulcanization of natural rubber and of cer little or no break-down before forming a rolling tain Synthetic rubbers. bank. Large amounts of carbon black could be 1. Sulfur, preferably used in conjunction. With milled into the copolymers. The compounded at least. One Vulcanization accelerator, that is a mixtures Were cured and tested with equipment Substance known to promote the Sulfur Vulcaniza and techniques used in the rubber and the syn tion of natural rubber. Suitable accelerators in thetic rubber industries. The vulvanized prod clude, for example, the following types of rubber uctS (Vulcanizates) were soft, flexible, elastic, vulcanization accelerators: -amines like rubberlike in appearance and feel, insoluble in the butyraldehyde-aniline, -mono 0. hydrocarbon and water, and resistant ethylamine and heptaldehyde-aniline condensa to OXygen, aging and heat. tion products; guanidines like diphenylguanidine; The practice of the invention is not limited thiazoles Such as mercaptobenzothiazole, benzo to the agents shown in the following tables. thiazy disulfide, Zinc benzothiazyl Sulfide, dini For example many emulsifiers can be used in trophenyl benzothiazyl sulfide admixed with di 15 stead of alkyl Sodium sulfate, and various per phenylguanidine, cupric Salt of mercaptobenzo Oxides and per compounds can be used to initiate thiazole, thiuram sulfides like tetramethyl thiu the polymerizations. ram monosulfide and disulfide, or di-N-penta Other esters of acrylic acid in addition to methylene thiuram tetraSulfide; dithiocarban those shown in the foregoing mentioned tables, ates such as N-pentamethylene ammonium pen Which Were used to prepare essentially Saturated tamethylene dithiocarbamate, Selenium diethyl and Vulcanizable alkyl acrylate copolymers in dithiocarbamate, zinc dimethyl- or zine dibutyl clude, Inethyl acrylate, propyl acrylate, butyl dithiocarbamate, 2,4-dinitrophenyl dimethyl di acrylate and other alkyl acrylates. thiocarbamate and cupric diethyldithiocarban Vulcanizates having similar properties were ate, sodium salt of dibutyl dithiocarbanic acid produced by preparing the corresponding copoly and other rubber Vulcanization accelerators like ners and subjecting them to vulcanization using the reaction, product of carbon bisulfide and procedures similar to those shown in the follow methylene dipiperidine, alkyl phenol sulfide, etc. ing tables. 2. Quinone derivatives described in U. S. Pat The discovery that halogen, cyano, ketone ent 2,170,191. Such as quinone dioxime and quinone (-CH2-CO-), and Similar groups can be used dioxime esters of aliphatic and aro; natic acids, instead of olefinic linkages to facilitate vulcaniza such as benzoquinone.. dioxime, which may be tion has broad application. For example, bromine used in combination with Suitable Oxidizing atOinS in a copolymer chain also act as active agents, for example, red lead, or in the form of centers in Vulcanization processes. their oxidation products as exemplified by the t st Reinforcing agents, fillers, accelerators and Vulcanizing agent COmprising polymerized di Similar rubber compounding ingredients can be nitrosobenzene as the active ingredient. added to the copolymers on a rubber mill or any 3. Dinitrobenzene used either Singly or in cora Suitable mixer, or the ingredients can be in bination with litharge. corporated in the emulsion or solution of the co 4. Peroxides, such as-benzoyl peroxide and so polymers. Solutions of the copolymers con forth. taining vulcanizing agents, accelerators and so In addition to the above-listed natural rubbel Oil, are useful as adhesives and rubber cements. vulcanizing agents, the alkyl acrylate copoly This invention is a valuable advance in the mers of the present invention are Vulcanized by art as it extends the known range of synthetic the action of amines and amine-condensation - rubbers, and provides new substitutes for rub products, for example, triethylene tetramine or ber which have in some respects advantages over triethyl trimethylene triamine. When used as natural rubber products. the Sole vulcanizating agent these amines ef Furthermore, the synthetic rubbers described fect rapid vulcanization of the alkyl acrylate co herein can be made almost entirely (through polymers; where used in combination with nat 50 lactic acid as an intermediate) from carbohy ural rubber Vulcanizing agents these amines or drates, an abundant, domestic, and reproducible amine condensation products accelerate the cur raW material. ing process and have a beneficial effect on the Although in the Specific examples illustrative resulting Vulcanizate. of preferred embodiments of our invention, syn . Data on Some Vulcanization procedures are : thetic rubbers are produced by conducting vul shown in Tables II, IV, VI, VIII, XI, XIV, XV canization in the presence of vulcanizing agents and XVII, and the properties of the resulting used in conjunction with vulcanization acceler vulcanizates are shown in Tables III, V, VII, IX, ators or promoters and conventional conpound XII, XV, XVII, and XIX. ing ingredients of natural and synthetic rubber The compounding ingredients listed in Tables 60 Vulcanizates, Such Synthetic rubbers can be ob II, IV, VI, VIII, XI, XIV, XVI, and XVIII include tained in accordance with the method of our in in addition to the aforementioned Vulcanizing Vention by Subjecting the copolymers to vul agents and accelerators other compounding in canization in the presence of only a vulcaniz gredients commonly utilized in the production ing agent. of natural and Synthetic rubber Vulcanizates to In the present Specification and claims the alter the chemical and/or physical properties of term "Vulcanizing agent" is meant to include the finished product. Thus, for example, carbon triethylene tetramine, triethyl trimethylene tri black is used as a reinforcing agent; zinc oxide a nine and equivalent amines and amine conden and in some instances litharge or magnesia, inay Sation products, as well as known rubber vul be added to render certain accelerators fully cailizing agents of the four types listed herein. effective. Stearic acid and similar Softening ...The following examples shown in tabulated agents are used as processing aids. form are illustrative of the invention. In all In preparing the vulcanizates the compounding of these examples, the physical properties of the ingredients were milled into the copolymers on final products were-determined by the procedure a standard rubber mill which had steam-heated of the A. S. T. M. Specification D-412-41. 2,600,414 TABLE Preparation of acrylic resins

ExampleSp Acry.hy Cononomer Anaount AcyE. si,Sulfate AmmoniumEersulfate water.'E' Temp.'86 P. Time,hrs' &SEgy late, g. title, g. (Emilisi- (catalyst.g. O Percent fier), g.

Benzyl Acrylate------7.5g O 4.0 0.03 250 8-92 2 90 a- a ------r > - - a - .5 4.0 0.02 250 78-92 44 88.5 BGloroethyl Ac- 7.5 g. 0.0 4.0 0.015 300 78-92 13 90, O ryate. PhenylAcrylate------5.0 g. 0.0 3.0 0.0 150 75-92 56 90.0 My Carbitol Ac- 7.5 g. 0, 0 4.0 0.03 300 80-92 13 93.5 ryate. Bicyanoethyl Ac- 7.5 g. 0.0 4. 0 0.03 300 80-92 126 910 ryuate. 2-Methyl-2-Nitro-i- 7.5 g. 0. 4. ), O2 300 7-92 1% 9. O Propyl Acrylate. - Bes Ioroethyl Ac- 15.0g. 0.0 4.0 0.015 300 82-9 2 88, rylate. Bithloroethyl Ac- 5.0 g. 6.0 3.0 0.12 150 78-9 134 92. rylate. 40 0.045 300 78-9 4-3 9.5 40 0.05 250 85-93 3 89.0

ABLE Vulcaniacation of copolymers of Table I Compounding Formula in Parts per 100 Parts of Copolyner Vulcani Eriple0. 28% Mercapto-Se...afi."recaptO- a. - Red Zinc Stearic Quinone Carbon Iron B thi methyl- Mi iii di peroxideBenzyl behiazole disulfidein (Min.)

20 20 240 1SO 240 2 24 240 24 20 2. 24 20 80 20 2 180 18 12 180 2:0 80 24 120 G

TABLE Physical properties of ulcanicates of Table II

Tensile Elonga Shore A Example No. strength, Hard lbs./sq. in. Per Celt SS

{ 1,410 480 65 ...... --X - - -n - w -a - - - a rar 640 490 45 ? 1,320 260 72 4------1,000 420 53 830 1,040 50 1, 610 400 64 3------870 500 45 1,280 88O 45 960 180 75 i------570 480 42 90 780 50 5------,090 30 55 1,670 450 65 6------50 40 45 1,090 860 ?3 7 470 410 3...... is as a as a m r - a- - - - -a as - - 760 440 4. 1,350 460 56 8------1,050 280 5 1,220 720 42 9 1,80 40 56 ...... was - as w w a -a as saw w w an as a s new 820 560 45 O 1,420 340 O ...... a------war ------war as a 80 520 52 ii------80 640 47 2,600,414 : - 9 10 TABLE IV Vulcaniadition of ethyl acrylate-chloropropyl acrylate copolymers Compounding formulain parts per 100 parts of copolymers Vulcanization Example No.

.

30 180 -213 50 - 240 ... 298 50 360 .298 75 240 .298 - 30 60 - 298 30 180 . .298 30 300 298 30 300 . . .298 30 ... 300 . . .298 30 240 298 30 -360 .298 240 298

NoTE 1.-Thesignificance: alphabetical characters shown under "the above compounding formula have the following A-Purified mercaptobenzothiazole. B-Zonic oxide, J-Cupric-Quinone salt dioxime... of mercapt Clu-Stearic acid. K-Cupric diethyldithiocarbamate.obenzothiazole. E--CarbonD-Sulfur. black. .L-Polyac (polymerized di-nitrosobenzene). F-Tetramethylthiuram disulfide. N-p-Dinitrobenzene.M-An organic polysulfide (polyethylene polysulfide). G-Anester type plasticizer. O-Litharge. H--Red lead. NoTE2.- The copolymer- was- - made: - ' from 95%P-Finely ethyla crylateground andcalcium 5% 3-chloropropyl carbonate. acrylate. NoTE 3-The compounded mixtures were cured in 4x4 x 0.23 inch molds, NoTE 4.-The copolymer used in the above vulcanizations was prepared from 200 g. of gamma-chloropropyl acrylate, 4,000ml. of ethyl acrylate, 5,000 ml of water, 80 g. of sodium alkylsulfate, 40 g.of the sodium salt of aryl alkylpolyether sulfonate, and 0.035.g. of ammonium persulfate. The polymerization NoTE 5-Thewas carried ester type out atplasticizer about from mentioned 82 to 90°C, under and Gis was a glycol finished di-octoate. in about 3 hours.

TABLE V Physical properties of vulcanieates of Table IV

Tensile Modulus Ultimate Permanenternanen Example No. Strength, at 600 Elongation, Shore A Set at Set (10 Hardiness Break, Permin), Per Product lbs./sq. in. Per Cent Per Cent Cent Cent

i, 210 830 790 956 1, 170 1,080 690 806 1,190 730 -- 690 1822 880 490 880 774 1,530 1, 450 650 994 1,490 660 940 1,400 1,370 1,070 740 1,014 1,440 990 790 1,133 1,460 1, 180 700 1,022 980 370 920 902 . .340 ------* - 560 750 l, 280 1,240 610 780

TABLE VI Vulcanization of halogen-containing acrylic resins Compounding FogliaIFifts per 100 parts of Wulcanization Epple Monomers grams A B C D E J. K. L. Tine, Tep. 24.----...- Ethyl Acrylate...... 190.510 || 2 | 2 | 30 298 25. 2-Bromoethyl Acrylate---- 10... 10 3... 30 298 26-- 3-Chloropropyl Acrylate.- . 100.5 10 2 2 30 298 (EEE3-Chloropropy - Acrylate------" 1801------10 .5" 10 - 2 230 ------298- - - 28------A6:STSite. - - - 38 ---- 10 3 - 30 298 29------(SEEin-Octyl Acrylate----- Acrylate.- --- ... 10 3 - 30 298 30 - (SEF; ;ate ------40 2 2 30 298 81------VV------;Spiege:Acrylate:Ethyl Acrylate-...----...-- 1403. ------103-30 ------298- - - 32. -E&SSyiAcrylate------Acrylate------5 }- 10 2 ---- 30 298 III) Ethyl Acrylate...... 90 K. 83.3 SS 35- 3-chloropropyl Acrylate. 10 {: 8 : 3: 3.

The alphabeti A-Purified mercaptobenzothiazole.characters shown hereunder E-Carbon have black.the following significance: B-Zinc oxide. F-Tetramethylthiuram disulfide. J-Polyac.I-Special furnace reinforcing black. C-Stearic acid. G-Redlead K-Triethylene tetramine. road Sulfur. H.-Quinone dioxime. L-Calcined magnesia. 2,600,414 TABLE WII TABLE X Physical properties of ulcaniaates of Table VIII Physical properties of ulcaniaates of Table VI ------Tense Ultimate Shore 5 Example No. strength, Elongation, A Hard Tensile Ultimate Shore A lbs./sq.in. Per Cent deSS Example No. strength, Elongation, Hardness ------lbs./sq. in. per cent 1,410 490 47

1,390 860 w 43 1,50890 350520 4850 0. ;S E8 1,420 600 53 1,320 860 37 1,550 460 6. 38 £8 i 940 170 88 1,330 650 46 1,150 820 51 1,380 470 58 :38 : i,1,350 540 770700 4746 5 3S S8 1,420 620 43 680 43 1,270 730 47 360 560 50 1,460 830 42 l, 630 540 6. TABLE VII Vulcaniadition of halogen-containing acrylic resins Compounding FoE in Eits per 100 Parts of Wulcanization Ex- polyIn age Monomers Grains 0. A B C D E F G E J K L. Time,min. TempF.

87------1,3-Dichloro-2-propyl Acrylate------20 --- 10 3 298 3S------Ethyl Acrylate------80 5 10 2 298 39------3-Bronopropyl Acrylate------14 ... 10 i 3 298 40------Ethyl Acrylate------186 .50 2 298 4. (Spils. Lactate------10 } 10 3 298 ------ESERegists.III '81. 42------(E.OTOpropyi Acrylate------ACryiate.------70 }.5 O 2 298 43------EFA E. ------ag ---- 0 3 298 44------3-Chloropropyly Acrylate------Acrylate------0 }- 0 2 320 45------Ethyl Acrylate------85.5 10 2 2 30 30 298 46------Vinylidene Chloride------15 ---- 10 2 ---- 80 ------30 298 47------3-Chloropropyl Acrylate - - - - 7 ---- 0 3 --- 30 20 298 48------Sec.-Butyl Acrylate------93.5 10 2 2 30 80 298 49------2-Chlorethyl Acrylate- 40.5 10 2 2 3 20 298 50------Ethyl Acrylate------60 ---- 10 3 ---- 30 30 298 51------CE: CHCOOCHCHOCECHCl- 10.5 I0 2 23? 360 298 52------Ethyl Acrylate.------190 ---- 0 3 ---- 30 80 298 1 The alphabetical characters shown hereunder have the following significance: A-Purified mercaptobenzothiazole. E-Carbon black. -Special furnace reinforcing black. B-2inc oxide. F-Tetramethylthiurain disulfide. J-Polyac. C-Stearic acid, G-Redlead. K-Triethylene tetramine. D-Sulfur. H-Quinone dioxime. L-Calcinedaagnesia. TABLE X Preparation of ethyl acrylate-methyl pinyl ketone copolymers

Monomers Emulsifiers - Catalyst Exam- Water, Ammonium Temp. Time Yield No.pie AcrylateEthyl MittyVinyl SodiumA ArylSu- isfit,ts 56' fi CentFer * Ketone, Sulfate, fonate, ptS. pts. otS. ptS. pts.

90 10 0.75 200 0.05 80-90 60 88 95 5 0.75 200 0.005 8-91 60 92 760 40 7.5 10 1,400 0.00 81-9 75 89

TABLE X Vulcanialation of copolymers of Table X

Copolymer Compounding ding FormulaFormul in PartsP Vulcaniza Example Methyl per 100 Parts of Copolymer i tion Time No. Ethyl Win in Erin. at Acrylate, Reft 298 F. tS. pts. p A : B c DEF an 53 90 10 10 10 3 230 ------...- 6. ------90 10 ---- 10 2 -- 30 0.5 2 1 120 53. 95 5 ---- 0 2 ---- 3(10.5 2 l 120 ------95 5 10 10 i 3 230 ------60 55------760 40 ---- 0 2 ---- 300. 5 2 60 1 The alphabetical characters shown hereunder have the following significance: A-Red lead. E-Carbon black. B-2inc oxide. F-Mercaptobenzothiazole. C-Stearic acid. G-Sulfur. D-Quinone dioxine. B-Tetrannethylthiliram disulfide.

13 - 14 TABLE X TABLE XV Physical properties of vulcaniaates of Table XI Physicaly cdt propproperties off sulcanieatess of Table XIV Tensile Elongation. Shore A - 5. Example No. Strength, at Break, Hard Tensile Elongation. Shore A lbs./sq.in. Per Cent ness Example No. Strength, at Break, Hard------lbs./sq.in. Percent SS - 1,190 900. 41 53 { 1,470 300 1,230.1,240 770740 5545 ------1,340 800 1,110. 860. 50 54 1,040 760 960, 920 53 ------1,400 550 1,210. 730 50 ------1,320 50 1,360 300 50 - 1,240 850 50 1,370. 860 4. 430 50 580 59 570 61 660. 60 760 60

TABLE XII Preparation of halogen-containing ethyl acrylate copolymers Epple Aegiate,Ethyl Cononomers pts. AmmoniunilPeriliate, Teap. , thisE. Fait

56------90 2-chloropropene.------10 0.045 65-95 165 90 57. 95 2-chloropropene--- - - 5 0.025 64-96 75 92 58 95 (SSEE ------3 0.012 65-90 60 80 ------chloropropylacrylate------2-chloropropene.------3 ------59------92 chloropropylacrylate------4. 0,010 79-90 75 93 SE------i 60------97 chloroallyl2-ClOOOOOele------alcohol------} 0.005 80-89 50 89 61------90 chloroallyl alcohol------. 10 0.015 82-90 60 89 62. 95 chloroallyl alcohol------5 0.008. 81-90 75 ------63- 98 chloroallyl alcohol------2 0.00 80-93 135 87 64- 90 2,3-dichloropropene------0 0.038 76-94 35 93. 65. 95 2,3-dichloropropene------5 0.027 73-96 120 85 66. 80 2-chlorallylpelargonate----- 20 0,040 83-94 90 75 67. 90 2-chlorallyl pelargonate------0 0.020' 81-92 20 90 68------95 dichloro-n-propyl acrylate---. 5 0.003 - 82-93 180 88 In each polymerization 200 parts of water, 1.5 parts of alkylsodium sulfate and 0.5 part arylsodium Sulfonate were used per 100 parts of monomers.

TABLE XIV Vulcaniadition of halogen-containing acrylic copolymers. Compounding Formula in parts per 100 parts Copolymer 1. . Vulcaniza ExampleNo. Copolymer centPer - tion.Minat Time, A B C D. E. F. G E - M 298 F.

69------1. 5 30 70------Ethyl acrylate------90 5 30 7l------2-Chloropropene.------10 1-2 15 120 72------5 60 73------Ethyl acrylate------. 95 5 120 74------2-Chloropropene-- 5 5 120 Ethyl acrylate. 95 21 .. 155 12030 2-Chloropropene 3. 1: 5 20 Chloropropyl acry 2 2 15 30 Ethy acrylate- 92 79 2-Chloropropene- 3 1 : 5 30 60 ------Chloropropyl acrylate--- 4. ------Isoprene.------E;Uhloropropene------acrylate- 9. 80------Chloropropyl acrylate--- 2 I 5 ---- 30 ----...-- 60 Isoprene------E. acrylate- - 9. 81------ChloropropylChloropropelle.------acrylate--- 0.510 || 2 || 2 | 1 |------1 - 5 ---- 30 ------60 Isoprene------Ethyl acrylate- 90. 82------2-Chloropropene------80. 510 2. 2. 1.------5 ---. 30...------30 Chloropropyl acrylate--- 2 1 The alphabetical characters shown hereunder have the following significance: A-Purified mercaptobenzothiazole. E-Tetramethylthiuram disulfide. -Calcined magnesia. B-2inc oxide. F-Redlead. J-Iron oxide. C-Stearic acid. G-Quinone dioxime. K-Carbon black, D-Sulfur. H-Triethylene tetramine, L-Polymerized di-nitroso benzene. M-Magnesium phenyl'stearate. 2,600,414 16 15 TABLE XVI Vulcaniadition of halogen-containing acrylic copolymers

Compounding Formula. Wulcaniza in parts per 100 parts Copolymer i tion Time Epple Copolymer di. in Min. A B C D E F G H I K. at 298°F.

Ethyl Acrylate--- 93 2-chloropropene.--- 3 30 60 Chloropropyi acrylate 4. Ethyl Acrylate 94 2-chloroprene----- 2 30 120 Chloropropyl acry 4. 30 20 Ethyl Acrylate------95 30 20 2-chloropropene------Chloropropyl acrylate------32 30 30 Ethyl Acrylate------97 2-chloropropene------2 30 20 2-chloroallyl alcohol------1. Ethyl Acrylate------90 ------i0 3 ------10 2 5 ---- 30 30 2-chloroallyl alcohol------10 : 0,5 : 0 2 2 ------5 ---- 30 30 - - - - - 10 - 3 ------0 2 5 ---. 30 30 Ethyl Acrylate------95 ----- 10 3 ------10 2 5 ---- 30 120 ---- 30 30 2-chloroallyl alcohol------5 0.5 10 2 2 ------5 30 30 Ethyl AcrylatACTylate------| 5 || 2 | ---- 30 20 95.------E-SSohai ------} 0.5 10 2 2 1 ------5 i he alphabetical characters shown hereunder have the following significance: A-Purified mercaptobenzothiazole. E-Tetramethylthiuran disulfide. I-Calcined inaglesia. B-Zinc oxide. E-Red lead. J-Iron oxide. C-Stearic acid. G-Quinone dioxime. K-Carbon black. D-Sulfur. H-Triethylene tetramine.

TABLE XVII Vulcaniaction of halogen-containing acrylic copolymers Ex- Compounding Formula in parts per 100 parts Copolymer 1 Vulcaniza Per- tion Time ample Copolymer cent in Min. at NO. A B C D E F : G I J K L 298 F.

Ethyl acrylate------90 ------(5.5orgie------1. - - - o - - - - 60

f. Ethyl acrylate------95 ------120 S. 2,3-Dichloropropene.------5 3: - - - - IS 100- 5 ---- 30 ---- 120 101-- 5 ---- 30 ---- 120 l02. 5 30 --- 30 103- Ethyl acrylate------97 15 30 - 20 3. 2,3-Dichloropropene------3 : --- 8 3 60 105. - - - - 60 106-- 15 1 30 --- 30 107------Ethyl lat 80 0.5 ------2 1 ------2 15 ---- 30 ---- 20 yl acrylate------108------SigExpelagonate------3: }------2 I5 30 ---- 30 109.------39thyl acrylate------yeargonate: - - i. } 0.5 10 || 2 || 2 || 1 ||--|--| 1 || 5 - 30. 60 110------(Biisipithyl acrylate------acrylate------53 } 0.5 10 2 2 1 ------1 5 ---- 30 ---- 20

1 The alphabetical characters shown hereunder have the following significance: A-Purified mercaptobenzothiazole. E-Tetramethylthiuram disulfide. I-Calcined magnesia. B-Zinc oxide. F-Red lead. J-Iron oxide. C-Stearic acid. G-Quinone dioxime. K-Carbon black. ulfur. H-Triethylene tetramine. L-Polymerized di-nitroso benzene.

TABLE XVII TABLE XIX Physical properties of vulcaniaates of Physical properties of vulcanigates of Table XVI 60 Table XVIII Tensile Example No. Strength, Elongationat Break, sh ore A Tensile Elongation lbs./sq.in. Per Cent Hardness Example No. Strength, at Break,s Shore A ---

i.S.S.R. "s' Hardness 80 1,100 31 20 1,100 40 83------1,200 730 45 380 900 34 84 1, 280 530 47 20 640 44 85 1,560 230 60 1,030 620 50 S6 1,280 580 49 980 1,100 40 8. 1,200 340 46 1,020 220 59 SS 930 820 5) , 340 450 45 S9. 2,020 10 84 1,160 480 46 90 1,670. 30 S2 1,100 550 44 9. 1,400 160 70 1,410 200 56 92 1,710 270 7. 1,400 500 47 93 1, 220 230 60 1,230 630 39 94 1,420. 70 4) 980 50 57 95------1,165 690 55 430 1,100 43 2,600,414 17 18 Having thus described our invention, we claim: REFERENCES CTED 1. A process of preparing a synthetic rubber comprising compounding a copolymer prepared The following references are of record in the from a mixture containing, as monomeric Com file of this patent: ponents, alkyl acrylate and methyl vinyl ketOne 5 UNITED STATES PATENTs in the proportion of from 80 to 98 percent of Nurnber Name Date acrylate to at least 2 percent of the ketone, with 1,121,134 Rohm ------Dec. 15, 1914 sulfur and heating the compounded mixture to 2,105,361 Nowak ------Jan. 11, 1938 effect vulcanization. 2,324,935 Kalutter et al. ------July 20, 1943 2. A process of preparing a synthetic rubber 0. 2,405,008 Berry et al. ------July 30, 1946 comprising compounding a copolymer prepared 2,416,878 Lindsey et al. ------Mar. 4, 1947 from a mixture containing, as monorilleric com 2,419,221 Kenyon et al. ------Apr. 22, 1947 ponents, alkyl acrylate and methyl vinyl ketone 2,442,330 Fuller ------June 1, 1948 in the proportion of from 80 to 98 percent of 2,451,174 Reuter ------Oct. 12, 1948 acrylate to at least 2 percent of the ketone, with 5 2,492,170 Mast et al. ------Dec. 27, 1949 a vulcanizing agent Selected from the group con sisting of Sulfur and the combination of quinone FOREIGN PATENTS dioxime and red lead, and heating the comr Number Country Date pounded mixture to effect vulcanization. 498,383 Great Britain ------Jan. 3, 1939 WILLIAM. C. MAST. 20 OTHER REFERENCES CHESSIE E. REHBERG. CHARLESH. FISHER. Mast et al.: "Wulcanization of Saturated Acrylic Resins,' article in Ind. Eng. Chem., vol. 36, pages 1022-1027 (November 1944).