896 



THE INDIA RUBBER WORLD 



September 1, 1921 



sists of lead sulphate 50 to 53 per cent, lead oxide 41 to 38 

 per cent, with small proportions of lead sulphide, lead sul- 

 phite, and zinc oxide. Zinc-lead oxide contains from 46 to SO 

 per cent of lead sulphate, from 52 to 46 per cent of zinc 

 oxide, and a small quantity of zinc sulphate. No zinc-lead 

 oxide is made at present. Leaded zinc oxide may vary from 

 4 to 20 per cent in lead sulphate, the remainder being zinc 

 oxide with a small proportion of zinc sulphate. 



As there are but two producers of sublimed or basic lead 

 sulphate, the output may not be revealed. The production 

 of litharge in 1918 was 44,102 short tons. 



'Mineral Resources rf the United States, 1918, Part I. 



MANUFACTURE OF RUBBER FROM THE LATEX' 



Crude rubber is made direct from the late.x, either at the plan- 

 tation or elsewhere, eliminating evaporation and smoking. 

 The latex is treated with a preservative mi.xture of very dilute 

 aqueous solution of alkalinized phenol to keep it fluid. Dilute 

 acid sufficient to neutralize the alkalinity of the preservative 

 treatment and acidify the latex is added, whereby nascent phenol 

 is liberated, causing rapid and complete coagulation — the bulk 

 of the impurities originally contained in th^ latex remaining 

 in solution. The coagulum is then subjected to a mechanical 

 dehydrating treatment adapted to disperse any bubbles formed 

 and to expel much of the moisture contained in the coagulum. 

 Subsequently it may be dipped in hot water, rolled into crepe 

 and kneaded until solid, or be pressed into blocks. In this way 

 the bulk of the mother liquor and dissolved impurities remaining 

 in the coagulum are sufficiently expelled without evaporative dry- 

 ing or other treatment preparatory to shipment. 



^British patent No. 159,602. S. C. Davidson, Sirocco Engineering Works. 

 Belfast. 



"AKSEX," A NEW ACCELERATOR 



"Aksel," the new vulcanization accelerator, is a dithiocarbonic 

 compound and is said to be the most active accelerator known 

 at present. Its activity in comparison with thiocarbanilide or 

 hexamethylene tetramine is dependent upon the kind of com- 

 pound used for comparison. In a zinc-crude-rubber compound 

 containing four per cent of sulphur, it is approximately 25 times 

 as active as thiocarbanilide, and five times as active as hexa- 

 methylene tetramine. 



It is a non-poisonous open-chain compound that works well 

 in the lowest grades of reclaimed rubber, and can replace litharge 

 at considerable saving in volume cost. It can be used satisfactorily 

 with litharge, lime, or magnesia, but not with antimony sulphide. 

 It is active in the hot-air cure. 



Rubber samples vulcanized three years ago are said to have 

 aged perfectly although they contained so much Aksel that they 

 were cured in three minutes at 50 pounds of steam. This remark- 

 able aging quality is probably due to the polymerization being 

 carried tc such a degree in the rubber that it is rendered inert to 

 further chemical change. Because of this quality this accelerator 

 is especially useful in improving the aging quality of very low- 

 grade stocks. 



CHEMICAL PATENTS 



THE UNITEID STATES 



PROCESS OF Devulcanizing Rubber consisting in subjecting 

 vulcanized rubber scrap to the action of oxalic acid. — Will- 

 iam Beach Pratt, Wellesley, Massachusetts, assignor to Rondout 

 Rubber Co., East Dedham, Massachusetts. United States patent 

 No. 1,382,669. 



Rubber Article and Method ok Manufacture, which 

 comprises mixing the rubber with a vulcanizing ingredient by 

 a suitable masticating operation and giving it an extended form, 

 then without further mastication dividing the rubber body into 



relatively small lumps, pressing the lumps together into a mass 

 having a form approximating that of the finished article and 

 vulcanizing the article. — William C. Geer, Akron, Ohio, assignor 

 to The B. F, Goodrich Co., New York, N. Y. United States 

 patent No. 1,382,774. 



CoMi'osiTiiiN FOR Shoe Soles. A wear-resi.'^ting composition 

 body coniprisinj; several layers of woven fabric impregnated with 

 and maintained in cohesion by rubber cement mixed w'ith pow'- 

 dered iron ore, the fabric material constituting the major portion 

 of the composition. — Henry K. Eckel, Milwaukee, Wisconsin. 

 United States patent No. 1,383,793. 



India Rchber Composition co.mprising a vulcanized mixture 

 of a caoutchouc-like substance and vulcanized fiber. — Arthur 

 Nixon, Manchester, England. United States patent No. 1,384,400. 



the united kingdom 



India Rubber Compositions. Resins are melted with 

 calcium chloride and filtered. About 10 per cent chloride of lime 

 and 2"/^ per cent of calcium chloride are added and the mixture 

 distilled. That which passes over at 160 to 180 degrees C. is 

 separated from the oils passing over at 340 degrees C. These 

 nils are again distilled with addition of 4 to 6 per cent of chlor- 

 ide of lime and the oil chlorinated by a third distillation with 

 10 to 40 per cent chloride of lime. To this product is added 1/6 

 of regenerated rubber previously extracted by ether or alcohol 

 to remove tarry impurities, or 1/12 new rubber to form in 12 to 

 24 liours a pasty mass. Oil from the second distillation is 

 added and the whole is vulcanized as usual. — G. F. de la Rosee, 

 Garmisch-Partenkirchen, Bavaria, Germany. British patent No. 

 164,006. 



Heel and Sole Composition. The following parts by 

 weight: solid tire scrap, 22; heel scrap, 10; black pigment, 3; 

 magnesium oxide, 13 ; sulphur and lime, % each ; reclaimed rub- 

 ber, 7; crude rubber, 4; and floating substitute, 2. This mixing 

 is vulcanized 25 minutes in an ordinary press and cooled five min- 

 utes. — A. A. Crozicr. Cambridge Street Rubber Mills, Bradford 

 Road, Manchester. British patent No. 164,159. 



Thio-Ureas are obtained by interaction OF carbon 

 bisulphide and aliphatic or aromatic amines at temperatures above 

 the boiling point of the bisulphide, and between the melting and 

 boilins; points of the amines. If aniline is used, it may be mixed 

 with 0.25 to 5 per cent or more of sulphur as a catalyst and 

 heated with stirring to 88 to 92 degrees C. while a stream of 

 carbon bisulphide vapor, with or without a little liquid bisulphide, 

 is passed through it. The temperature may be raised slowly to not 

 to exceed 110 to 115 degrees C. The escaping vapor passes 

 through a condenser and an aniline scrubber to remove carbon 

 bisulphide, and the residual hydrogen sulphide may be burned or 

 absorbed in caustic soda. When the reaction has materially 

 slackened, the supply of carbon bisulphide is stopped and the 

 liquid heated to 130 to 135 degrees C. and then run into a churn 

 containing cold water. Steam is passed through the pasty prod- 

 uct to remove free amine, the water is drained off, and the 

 product dried in air or vacuum. The process may be applied to 

 toluidines. xylenes, amino-dimethyl-aniline, amino-cymene, etc. — 

 The Goodyear Tire & Rubber Co., Akron, Ohio, assignee of W. 

 J. Kelly, Akron, Ohio, and C. H. Smith, Edgewood, Maryland. 

 British patent No. 164,326. 



Pl.\stic Compositions. A moldable composition applicable 

 as a substitute for vulcanite, consists of peat, sawdust, or other 

 vegetable fiber, india rubber, gelatine, sulphur, lampblack, shellac, 

 and stearine pitch. — F. L. Schauerman, East Twickenham, Mid- 

 dlesex. British patent No. 164,392. 



GERMANY 



Insulation for Submarine Telephone Cables. Gutta 

 percha partly or completely freed from resin and then mixed with 

 natural or synthetic rubber possesses certain advantages over 



