Patented ‘Jan. 7-, 1947 " _ ‘2,414,065 “ _ UNITED STATES i-PATENT 'orrica» RUBBER HYDROCHLORIDE COMPOSITIONS Win?eld Scott, Akron, Ohio’, assignor to Wing foot Corporation, Wilmington, Deb, a corpora tion of Delaware , ' ' No Drawing. Application August 8, 1942. > Serial No. 454,123 _ 2 Claims. (Cl. 260-735) 1 V . 2 . This invention relates to the stabilization of ' rubber hydrohalides against deterioration by the alicyclic or a'ralkyl. It may also be a heterocyc'lic I alicyclic substituent as in morpholine derivatives, action of light, either direct or diffused. More or other equivalent neutral groups. R1 is any of particularly, it is'directed to the use of nonvola the same substituents as R though it is not nec tile, basic, photochemical inhibitors which may 5 essarily the same as R in the same molecule. R2 be used in_ rubber hydrochloride ‘compositions ' - represents and which improve the stability of the rubber hydrochloride regardless of whether the'rubber ‘ hydrochloride contains an elasticizing material or is.unelasticlzed. - > . a straight ' or branched aliphatic‘ radical as found in the fatty acids. This radical may contain substituents such as hydrox‘yl as would be the case in ricinolelc acid. l0 unsaturated as in oleic acid. R2 may be It can be readily It is known to those familiar with the art that seen that the number of acids that maybe used rubber hydrohalides under certain conditions, is considerable without departing from the spirit especially upon exposure to sunlight, deteriorate of the invention. The following examples illus relatively rapidly, and their useful life is but a trate the preparation of such amides: ‘fraction of what it would be under different con- 15 E l 1 ditions of exposure. The purpose of the present invention is to provide a new class of stabilizers ' which'are useful in both prevention of, deterioration and in the plasticization or elasticiza- ‘ramp 6. ' Fifty-seven and four. tenths parts of' stearic acid and 37.8 ‘parts of tetraethylene pentamine were mixed and heated together in a suitable re- Y tion of rubber hydrohalide ?lms. 20 actor equipped with a condenser and thermome The stabilizers of this invention have extremely ter. At a temperature of 150° C. reaction is ob low vapor pressures so that they can be classed vious. The temperature is raised to about 200° C. as nonvolatile. They, therefore, remain in the and maintained until no more water is obtained rubber hydrochloride ?lm and protect it for a as a distillate. This requires abouttwo-hours. longer time than other stabilizers which are more 25 A. quantitative yield of a waxy solid is obtained. voltaile. It is believed to have the following formula: The elasticizers or plasticizers which have preH,N_(CH,_CHPNH>PCHFCHPNH~C O'_(CH2)M_CH, viously‘been used for increasing the tear strength‘ and to give a softer feel to rubber hydrochloride - Ea: Z‘z amp e h \ ' ?lms have usually been esters of higher fatty 30 The amide formed form equal molarv propor acids, such as butyl stearate, etc. The stabilizers tions of abietic acid and tetraethylene pentamine of this invention are compatible with such elaswas prepared by heating together methyl abietate ticizers and themselves have a de?nite elasticizand tetraethylene pentamine with the removal ing action which permits the use of less of the of methanol. Sixty-three and three tenths grams usual elasticizer or its omission altogether in 35 of methyl abietate and 37.8 of tetraethylene pent order to‘ give a ?lm which is elasticized to the eXamine were heatedfor four hours at 200-215" C. tent desired. A few per cent of one of the sta- bllizers of this invention, as for example 2 to 8 per cent, will give a marked improvement in the sta- or until no more methanol was given off or no ' further loss in weight of the reaction mixture was observed. The ?nal product was a soft, am bility of the ?lm. Up to 15 per cent of an amide 40 ber~colored resin. of this‘invention may_ be used to stabilize the ?lm and to elasticize it. ' The stabilizers or photochemical inhibitors of v _ 'the present invention are amides formed by the reaction of a carboxylic acid with a polyalkylene polyamine with the. elimination of water. Usual ly, one mol of acid will be reacted with one mol of the amine to form the inhibitor of deteriora ' Example 3 _ Capric acid and tetraethylene pentamine read- , r ily react to form an amide by heating together the ‘two materials. Fifty-one and six tenths parts‘ of capric acid and 56.7'parts of tetraethylene' pentamine were heated together at 180-200“ for , tion, but more than one mol of acid may beused one and a half hours, when 5.1 g. of water was in the reaction. 'I'hefollowing equation illus condensed. ‘trates the formation of the amides of this in- ' vention: ' The product is a, viscous liquid ‘that ' Y deposits some crystals on standing. A quantita tive yield was obtained. ' ‘ ‘ Example 4 . Two molar proportions of capric acid ‘react with “ ‘ In the foregoing formulae, R is hydrogen, alkyl, 55 tetraethylene pentamine to give a diamlde of the“ ' 2,414,065 3. gether, as in the examples above, 103.2 parts of capric acid and 56.7 parts of tetraethylene pent Such amines may be made from a mixture of al kylene halides and a mixture of ammonia and primary aliphatic amines. It is not necessary ‘that all amine groups be unsubstituted as in the amine. At 200° C. the calculated amount of wa ter was formed, and the yield of diamide was the oretical. The product is a yellowish, crystalline mush. 4 Although ethylene amines have been disclosed speci?cally, it is possible to use propylene amines or mixed ethylene and proplene amines, etc. . base. This material was prepared by heating 'to . case, for example, of tetraethylene pentamine. ' Example 5 Some must be unsubstituted for reaction with The amide from lauric acid and triethylene 10 acids to form amides. tetramine was prepared by heating these two As illustrative of this invention, there was pre materials together with the removal of water. ' pared a benzene cement, containing rubber hy ‘Heating was continued for one and a half hours at 190-198“ C. The product was made from 50.0 g. of lauric acid and 36.5 g. of triethylene tetra mine and was obtained as a light-colored, low drochloride and butyl stearate in an amount equal to 5 per cent of the weight of the rubber hydro 15 chloride to which the amides prepared accord-v ing to the above examples were added in an melting solid in quantitative yield. Example 6 amount equal to 5 per cent of the weight of the rubber hydrochloride. Films cast from this ce ment all had materially longer life than the simi Myristic acid, 68.4 g. was heated with tri ethylene tetramine, 43.8 g. for two hours at 20 larly prepared ?lm which contained no stabilizer. What I claim is; l80-197° C. During the reaction 5.2 g. of water 1. A rubber hydrochloride ?lm which contains was obtained as a distillate in a heating vtime of as a stabilizer an amide of a monocarboxylic ali two hours. The amide is a light, waxy solid. Other ‘acids ‘may be used than those shown in the foregoing examples; among such would be isobutyric, hexoic, beta-ethyl hexoic, pelargonic', undecylenic; palrnitic, oleic, hydroabietic, lactic, butoxy acetic and phenoxy acetic acids. 25 phatic acid with a polyalkylene polyamine. 2. A rubber hydrochloride ?lm which contains as a stabilizer an amide of a monocarboxylic ali phatic acid with a polyethylene polyamine. - . WINFIELD SCOTT.