THE INDIA RUBBER WORLD 



|.\. 



1, 1919. 



Notes on the estimation , of resin and impurity in balata and 

 gutta percha by P. Dekker are abstracted as follows by tlie "Jour- 

 nal of the Society of Chemical Industry," volume 27, 341 A: 



Acetone is the most trustworthy solvent for the extraction 

 of balata and gutta percha. Ether dissolves a part of the gutta 

 or balata and so gives high results, while with alcohol the gutta 

 becomes plastic on account of the higher boiling point of the 

 solvent, and the extraction is thereby rendered incomplete. When 

 balata is extracted with alcohol a portion of the material in- 

 soluble in xylene passes into solution and is included with the 

 resinous matter. 



DEPOLYMERIZATION OF RAW RUBBER. 



The depolymerization of raw rubber as reporied by A. Van 

 Rossem is outlined in abstract as follows by the "Journal of the 

 Society of Chemical Industry," volume 37, 341A: 



When rubber is heated for six hours at 130 degrees C. in a 

 sealed glass tube containing air, it melts to a brown syrup, 

 ■whereas this change is not observed in a vacuum or in hydrogen, 

 nitrogen, or carbon dioxide. With one per cent rubber solutions 

 in xylene, oxidation does not set in until after several hours, 

 commencing first when a certain limit of relative viscosity has 

 been passed. Depolymerization occurs much more rapidly in 

 the presence of oxygen than in that of other gases, oxygen ap- 

 pearing to exert a catalytic effect; the rate of depolymerization 

 depends also on the nature of the solution. 



CHEMICAL AND MECHANICAL-TECHNICAL EXAMINATION 

 OF RUBBER. 



The following abstract from the "Journal of the Society of 

 Chemical Industry," volume 37, 341A, summarizes a contribution 

 by J. G. Fol : 



In order to form a correct judgment on the quality of rubber 

 it is necessary, in addition to making chemical analysis and 

 vulcanization tests, to ascertain whether the various original 

 constituents of the rubber and any substances which have been 

 subsequently incorporated in it, remain in the same relative pro- 

 portions and can be rediscovered by chemical analysis. Pre- 

 liminary experiments have led to the following conclusions : — the 

 resin content remains practically constant throughout the various 

 operations, although a slight decrease may sometimes be observed 

 after vulcanization. The proportion of insoluble constituents is 

 decreased by mechanical working. The protein matter is not 

 quantitatively precipitated by the petroleum method applied for 

 the separation of insoluble substances. When free sulphur is 

 present to the extent of several units per cent, it cannot be 

 oxidized quantitatively by nitric acid. The estimation of fillers 

 by boiling with petroleum yielded low results with the mixture 

 investigated (rubber 50, zinc oxide 62, magnesia 13, sulphur 5), as 

 also did the determination of the ash. The viscosity of the rub- 

 ber is diminished by mechanical working on the washing rolls, 

 and still more by working on hot rolls ; this is attributed to a 

 reduction in the molecular complexity. The indirect method for 

 the estimation of rubber in a vulcanized product gives results 

 which deviate several units per cent from the quantity of rubber 

 actually used. 



YARN TWIST-TESTER. 

 Tests can be made on samples from one inch to 20 inches in 

 length with the latest type twist-tester for yarns. The tension 

 of thread between clamps is always the same, being regulated 

 with small weights. As the yarn is unwound, one turn of the 

 handle loosens ten turns of twist, the left-hand clamp is drawn 

 to the left by small weights holding the yarn taut, and at the 

 same time the take-up is registered on a special scale. The 

 take-up, especially on hard-twisted yarns, is a very important 

 factor in determining the size of the single yarn used in making 

 the ply yarn. The spinning twist can be accurately determined 

 by means of a magnifying glass through which the operator can 

 watch the fibers unwind. A similar apparatus for yam twist 

 testing is also made by Goodbrand & Co., 19 Victoria street, 

 Manchester, England. (Alfred Suter, 200 Fifth avenue, Xew 

 York City.) 



CHEMICAL PATENTS. 

 THE UNITED STATES. 



Pruiess of Tre.ating Rubber Waste. — The process consists of 

 subjecting waste rubber containing cotton to the action of a re- 

 claiming solution consisting of approximately two per cent by 

 weight of sodium hydroxide, and also containing kerosene and 

 resin in the approximate proportions of five pounds of resin and 

 15 jxjunds of kerosene to 100 pounds of wa.ste rubber, main- 

 taining the temperature of the reclaiming solution at about 300 

 degrees F., and agitating the solution and rubber waste. (John 

 F. Johnston, Barberton, assignor to The Electric Rubber Re- 

 claiming Co., Akron, both in Ohio. United States patent No. 

 1,291,535.) 



I'uTTu.N CoNTAiMXG RuBBER COMPOSITION. — A product prepared 

 from rubber waste containing cotton and comprising reclaimed' 

 rubber containing substantially uniformly distributed cotton fiber 

 which has been subjected to the action of a caustic alkali re- 

 claimed from the cotton in the waste rubber. (John F. Johnston^ 

 Barberton, assignor to The Electric Rubber Reclaiming Co., 

 Akron, both in Ohio. United States patent No. 1,291,536.) 



Process for Vulcaxizixg Rubber and Products. — .\ process 

 for treating rubber or similar material which comprises subjecting 

 the rubber to beta-dinitroanthraquinone. (Willis A. Gibbon, 

 I'liishing, assignor to New York Belting & Packing Co.. New 

 York City — both in Xew York. United States patent No. 

 ;, 291,828.) 



.Adhesive Material. — An adhesive composition for uniting 

 fabric surfaces, consisting of a dextrin, water, and castor oil held 

 in emulsified condition. (-■Mfred E. Jury, New York City, as- 

 signor to National India Rubber Co., Bristol. Rhode Island. 

 United .States patent No. 1.292.333.") 



THE DOMINION OF CANADA. 



Rubber Coagulum. — The process of treating latex or similar 

 material, which comprises subjecting the mass to an hydroxy 

 derivative of a polycyclic member of the benzene series, forming 

 a substance adapted to prevent slime formation and combining a 

 vulcanizing agent with the mass. (The Canadian Consolidated 

 Rubber Co., Limited, Montreal, Quebec, Canada, assignee of Ed- 

 ward Mark Slocum, Medan, Deli, Sumatra, Dutch East Indies. 

 Canadian patent No. 188,135.) 



Rubber Coagulum. — The process of treating a mass of rubber 

 coagulum or similar substance containing a protein and water, by 

 applying to the mass an alcoholic solution of beta-napthol, form- 

 ing on the surface of the mass a semi-permeable membrane of 

 water-insoluble compound of protein and beta-napthol adapted to 

 prevent passage of colloidal nitrogeneous or similar material, and 

 combining a vulcanizing agent with the mass. (The Canadian 

 Consolidated Rubber Co., Limited, Montreal, Quebec, Canada, 

 assignee of Edward Mark Slocum, Medan, Deli, Sumatra, Dutch 

 East Indies. Canadian patent No. 188,136.) 



L.\TEX Product. — A compound rubber mass produced by 

 vacuum evaporation, containing an insolubilized nitrogeneous 

 compound comprising a substance of the benzene series. (The 

 Canadian Consolidated Rubber Co., Limited, Montreal, Quebec, 

 Canada, assignee of Edward Mark Slocum, Medan. Deli. Su- 

 matra, Dutch East Indies. Canadian patent No. 188.137.) 



Brake Lining. — A brake lining consisting of a body of fibrous 

 material impregnated with the product of the vulcanization of 

 asphalt, red lead, and sulphur. (The Thermoid Rubber Co.. as- 

 signee of William Dolton Pardoe — both of Trenton. New Jer- 

 sey. Canadian patent No. 188,392.) 



Tire Filler. — .\ composition of ingredients substantially in 

 the following proportions: soya bean oil, 24 pounds: chloride 

 of sulphur, six pounds; oxide of magnesia, 17H otmces, and 

 \'enetian red, three ounces. (The Universal Tire Filler Co., 

 assignee of Frank A. Hager, both of Portland, Oregon. Cana- 

 dian patent No. 188,448.) 



