Document NqOdOZGoX3XpjD6qB7qzYxdy

2,428,200 13 14 tion elements In the practice of the present In material and its resistance to heat decomposi vention. tion or heat depolymerization. The graphs In Figs. 1 and 2 show, among other As Indicated at 12 in Fig. 1, a specimen of things, the percentage of acetone-soluble or un finely divided particles of butadiene-acrylonitrile polymerized monomer fraction or material pres- 8 copolymer synthetic vulcanized rubbery elasto ent in the specimens prior to their being sub prene, vulcanized with five per cent, by weight, jected to the heat tests; the loss in weight in of sulphur, showed a loss of only about 5.26 per terms of per cent in the! specimens tested as cent, by weight, as measured in terms of vola measured by the percentage of acetone-soluble tile material, after having been subjected to a monomer or depolymerized material, and other 10 substantially constant temperature of 260 C. for acetone-soluble material resulting from the heat a period of 19.5 hours. Moreover, as indicated at decomposition of the heat'polymerized oils em ployed In preparing certain of the specimens, due to the heat tests made thereon; the loss in weight 13 in Fig. 1, a specimen of this material Showed a loss of only 0.21 per cent by weight, as meas ured in terms of benzol-soluble material, after In terms of per cent in the specimens tested as 15 having been subjected to a substantially constant measured by the percentage of benzol-soluble temperature of 260 C. for 19.5 hours, thus indi material formed in certain of the specimens and cating the high degree of resistance to heat de resulting from heat decomposition thereof dur composition possessed by this material. ing the heat tests; and the loss in weight in As indicated at 14 in Fig. 1, a specimen of finely terms of per cent in the specimens tested as 20 divided,particles composed essentially of buta ^measured by the percentage of volatile materials diene-acrylonitrile copolyiner vulcanized with five , given off by the specimens during and as a result per cent, by weight, of sulphur contained about of the heat tests. eight per cent by weight, of acetone-soluble or It will be noted, in this connection, that the monomer material, and a specimen of the same percentage of acetone-soluble material which was 25 material showed a loss of about. 6.5 per cent, by present in the specimens tested after they had weight, as measured in terms of loss of volatile been subjected to the heat tests, is a measure of material, after having been subjected to a sub the percentage of monomer fraction or beat de polymerized material, and other products of heat decomposition, in general, present in such sped- 30 stantially constant temperature of 315 C. for a period of one hour, as indicated at 15 in Fig. 1. As indicated at 16 in Fig. 1, a specimen of finely mens after they had been subjected to the heat tests. This test is also a measure of the per centage of the products of heat polymerization and heat decomposition, in general, formed in friction elements containing such materials when said friction elements are subjected to the tem peratures to which such friction elements are subjected in use. Similarly, the percentage of benzol-soluble ma terial present in certain of the specimens, after 35 40 divided particles composed essentially of buta diene-acrylonitrile copolymer type synthetic vul canized rubbery elastoprene, vulcanized with ten per cent, by weight, of sulphur, when tested at atmospheric temperature, contained about 4.58 per cent, by weight, of acetone-soluble or depoly merized material. . A specimen of finely divided particles composed essentially of butadiene-acrylonitrile copolymer compounded with ten per cent, by weight, of sul phur, showed a loss of about 5.60 per cent, by they had been subjected to the heat tests, is a weight, as measured in terms of volatile material, measure of the extent to which such specimens after having been subjected to a substantially tested had undergone heat decomposition during constant temperature of 260 C. for a period of and as a result of the heat tests, and this test 19J> hours, as Indicated at 38 in Fig. 1. is employed as a measure of the extent to which As Indicated at 17 in Fig. 1, a similar specimen the friction-controlling materials referred to in of this materia] after having been subjected to certain of the graphs have undergone heat de- .. a substantially constant temperature of 260 C. terioration or decomposition. for a period of 19.5 hours showed a loss by weight, The percentage of volatile material present in .. as measured in terms of acetone-soluble material, the specimens, after they had been subjected to of only about 0.27 per cent, thereby exhibiting the heat tests, is also a measure of the compara the marked resistance to heat depolymerization tive stability of such materials when used as possessed by this material. friction-controlling agents or ingredients in fric A specimen of finely divided particles composed tion elements, and further indicates the extent SR essentially of butadiene-acrylonitrile copolymer or degree of heat decomposition of the materials tested. type synthetic vulcanized rubbery elastoprene, compounded or vulcanized with ten per cent, by As indicated at 10,- in Fig, 1, a specimen of weight, of sulphur, showed a loss in weight, as finely divided granules or particles composed es measured in terms of benzol-soluble material, of sentially of butadiene-acrylonitrile copolymer ^ only 0.22 per cent, after having been subjected to synthetic vulcanized rubbery elastoprene, vulcan a substantially constant temperature of 260 C. for' ized with five per cent, by weight, of sulphur when tested at atmosphere temperature con a period of 19.5 hours, as indicated at 18 in Fig. 1. As Indicated at 18 in Fig. 1, a similar specimen tained about 4.67 per cent acetone-soluble un of this material when subjected to a substantially polymerized or monomer material. However, as eg constant temperature 0! 315 C. for a period of may likewise be seen by reference to Fig. 1, and one hour, showed a loss of only about 7.6 per cent, as therein indicated at II, a specimen of finely by weight, as measured in terms of loss of vola divided particles or granules of butadiene-acrylo tile material, and, as indicated at 20 in Fig. 1, nitrile copolymer synthetic vulcanized rubbery a similar specimen of the same material showed elastoprene, vulcanized with five per cent, by 70 a loss of only about 7.4 per cent, by weight, as weight, of sulphur, after having been heated for measured In terms of acetone-soluble material, 19.5 hours at a substantially constant tempera when subjected to a substantially constant tem ture of 260 C,, contained only about 0.28 per cent, perature of 315 C. for a period of one hour, by weight, of acetone-soluble or monomer mate thereby further demonstrating the marked re rial, thus indicating the marked stability of this 75 sistance possessed lor this material to beat deteri- 9