November 1, 1918.] 



THE INDIA RUBBER WORLD 



The principal difficulty is to prevent the formation of a film 

 on the upper surface which hinders coagulation of the mass 

 beneath it. This can be done by keeping the upper surface in 

 movement, using the air current to actuate a fan connected to a 

 light wooden rod running the length of the wooden case above 

 the cakes, and having scrapers attached to it that lightly touch 

 the upper surface and keep it in motion. It seems that this 

 evaporation method succeeds very well in a crepe factory and 

 that no complicated installation is necessary. 



The making of "slab" rubber is very simple under proper 

 control of the putrefaction. To do this it is desirable to allow 

 the process to take place in a separate building to prevent all 

 kinds of infection. The upper surface of the cakes should be 

 washed with clean water once every 24 hours. The machines 

 which work up the slabs should also be carefully disinfected. 



The author states that the color of the crepe produced by his 

 method was at first very irregular, but this difficulty has been 

 since almost overcome. Mr. Zuyderhofif intends to enlist the aid 

 of a government experiment station for aid in further developing 

 his process. 



PURITY OF CASTOR OIL. 



The following method for determining the purity of castor 

 oil, reported by "Chemical Abstracts," has been worked out by 

 Chercheffsky. It is based on the critical temperature of solu- 

 tion which is defined as the temperature at which a fat in a 

 suitable solvent becomes turbid when this temperature is above 

 the boiling point of the solvent. The method is as follows : A 

 glass tube ten centimeters long and eight millimeters wide is 

 closed at one end, ten drops of castor oil and 40 drops of ethyl 

 alcohol of 0.8481 specific gravity added, and the tube sealed and 

 attached to a thermometer and placed in a glycerol bath. The 

 bath is then gently heated, using the thermometer as agitator. 

 When a turbidity persists the temperature is read. This is con- 

 stant for every fat. The following table shows results with mix- 

 tures of castor oil and other oils. The critical temperature for 

 castor oil is 66 degrees, and as small an amount as two per cent, 

 of foreign oil raises the critical temperature from three to five 

 degrees. 



Per cent of foreign 



50 



75 



100 



Kind of on. Critical Temperatures. 



Colza 71° 76° 82' 92" 109° 129° 155° 188° 202° 



Peanut 70° 74° 81° 90° 105° 120° 149° 186° 197° 



Cottonseed 71° 74° 81° 89° 97° 104° 138° 161° 172° 



Linseed 69° 74° 79° 85° 94° 105° 129° 152° 163° 



Fish 70° 74° 79° 86° 92° 103° 133° 158° 167° 



SEPARATION OF THE INSOLUBLE MATTER IN CRUDE RUBBER. 



For the separation of the insoluble matter in crude rubber 

 Stevens and Clayton Beadle employ phenetol. \ gram of rubber 

 in small pieces is placed in a test tube with ten cc. of solvent 

 and heated slowly, so as to reach 100 degrees C. in an hour, 

 and 140 degrees C. in the next half hour. During this heating 

 a peculiar odor is given off, resembling that of toasted (broiled) 

 meat. After cooling, the solution is diluted with 100 cc. of 

 benzine and the insoluble matter allowed to settle. It is washed 

 twice by decantation with benzine, transferred on a tared 

 filter, washed again with benzine, then with alcohol and water, 

 and dried. 



CHEMICAL PATENTS. 



THE UNITED STATES. 



TR1'..\TMEXT OF Tires — Tires composed of rubber or rubber- 

 like materials and fiber are placed in open molds in a vul- 

 canizer and entrapped air, gases, and fluids extracted therefrom 

 at an elevated temperature by vacuiim, before closing the molds 

 and vulcanizing. (Raymond B. Price, assignor to Rubber Regen- 

 erating Co., both of New York Citv. United States patent No, 

 1,276,416.) 



Br.\ke Lining and Process of Making. — TTie method con- 

 sists in impregnating a body of fabric with a solution containing 

 asphalt, an oxide of lead, sulphur, and an oxidation accelerator : 

 and then vulcanizing the impregnated fabric under high heat 



and pressure. (William D. Pardoe, assignor to Thermoid 

 Rubber Co., both of Trenton, New Jersey. United States patent 

 No. 1,277,108.) 



THE DOMINION OF CANADA. 



Pigmented Rubber. — Process and material of coating pigment 

 dust on an uncured rubber surface, and vulcanizing it under a 

 superimposed layer of metal such as aluminum in sheet or pow- 

 der form. (The Canadian Consolidated Rubber Co., Limited, 

 Montreal, Quebec, Canada, assignee of Willis .A.. Gibbons, Flush- 

 ing, Long Island, New York. Canadian patent No. 184,218.) 

 THE UNITED KINGDOM. 



Waterpkoofixg Compositions.— For tarpaulins, etc., gum tra- 

 gacanth dissolved in water is mixed with lead acetate or alumi- 

 num sulphate. These salts may be mixed and the clear solution 

 of aluminum acetate be applied to the fabric, or the fabric may 

 be treated with the solutions separately and lead sulphate pre- 

 cipitated in the fibers. For lighter fabrics, gum tragacanth is 

 mixed with soap dissolved in alcohol and then with aluminum 

 sulphate or lead acetate. (J. D. Williams, IS Bodford street, 

 Rhyl, Denbighshire. British patent No. 114,494.) 



India Rubber. — Vacuum treatment for removal of fluids from 

 unvulcanized rubber. (W. J. Mellersh-Jackson, 28 Southampton 

 Buildings, London. [General Rubber Co., 1790 Broadway, New 

 York City, U. S. A.] British patent No. 116,322.) 



India Rubber.— Coagulated rubber, gutta, chicle and like 

 latex is treated with a selection of organic compounds in order 

 to form in the coagulum an insoluble layer to prevent the passage 

 through it of colloidal nitrogenous matter. (W. J. Mellersh- 

 Jackson, 28 Southampton Buildings, London. [General Rubber 

 Co., 1790 Broadway, New York City, U. S. A.] British patent 

 No. 116,323.) 



Latex Treating.— A vacuum process of drying coagulated or 

 uncoagulated latex. (W. J. Mellersh-Jackson, 28 Southampton 

 Buildings, London. [General Rubber Co., 1790 Broadway, New 

 York City, U. S. A.] British patent No. 116,324.) 



India Rubber. — Rubber latex is treated with a member of the 

 benzene series or a derivative thereof, in order to conserve its 

 contained nitrogenous and other constituents and to prevent the 

 formation of slime. For instance, the latex may be treated 

 with 0.2 per cent of beta-naphthol before or after the addition 

 of sulphur, and the product may in addition be given a surface 

 treatment with an alcoholic solution of beta-naphthol. (W. J. 

 Mellersh-Jackson, 28 Southampton Buildings, London. [General 

 Rubber Co., 1790 Broadway, New York City, U. S. A.] British 

 patent No. 116,326.) 



AUSTRALIA. 



Wood-Paving Joint. — A joint of rubber and cork composition, 

 intended to counteract the expansion and contraction of blocks 

 in wood pavements. (W. Stawell and H. C. Nankwell, attor- 

 neys of I. Manchester, Victoria. Australian patent No. 4,879.) 



N' 



OTHER CHEMICAL PATENTS. 



THE UNITED STATES. 



).|0. Method of vulcanizing molded rubber an 

 He.nly and A. A. Frank, Milwaukee, assisnors 

 Rubber Co.. Cudahv— both in Wi; 



1,274,091. Manufactn 

 Canada, 



.273.954. Coating compos 

 sicnor to Ger 



.U9. 



fille 



ard, Toronto. Ont., 



3n. C. P. Townsend. Washington, D. C. as. 

 ■al Bakelite Co., New York City. 



and process. E. B. Respess. New York City. 



Hager, Portland, Ore. 



THE DOMINION~bF CANADA. 



l,S.i.662. Dei'tal rubber compound. C. J. R. Engstrom. Los Angeles, 



Cat, assignee of S. C. Supples. F.ast Orange, N. J. — both in 



the U. S. A. 

 184,217. Vacuum treatment to withdraw fluids from unvulcanized rubber, 



etc. The Canadian Consolidated Rubber Co., Limited. Mon. 



;rca!. Que., Canada, assignee of R, B. Price, New York City, 



CEYLON. 



1,5^7. Improvements in adhesive rubber coni]iositi.Mi. Ctncral Rub- 

 ber Co., New York City, U. S. A. 



1.350. Separating rubber from rubber-containing material. General Rub- 

 ber Co., New York City. V. S. A. 



