658 



THE INDIA RUBBER WORLD 



VULCANIZATION OF CAOUTCHOUC AND ITS 

 REGENERATION. 



Till-', cluiiiical iiivestiKatiuii of the vulcanization ol caoutchouc 

 and the- iiossibility of its regeneration from the vulcanized 

 product is the subject of a paper Uy I. C. Harries in "Berichter," 

 1916 [Vol. 49. |)ages 1196-1201]. In the ordinary hot vulcaniza- 

 tion process with about 10 per cent of sulphur, two distinct stages 

 must be differentiated. The primary action is an absorption 

 l)beiioincnon. since the sulphur can be extracted practically quanti- 

 tatively with a solvent such as acetone, and, moreover, does not 

 pass into the derivatives, such as the hydrochloride, which con- 

 tains only a trace of sulphur, although, unlike the hydrochloride 

 of natural caoutchouc, it is quite soluble in chloroform. On the 

 other hand, a vulcanized caoutchouc which has been kept for a 

 long time in a warm place, contains from 2 to 4 per cent of 

 sulphur, which resists the action of solvents, and it also gives a 

 sulphur-containing hydrochloride. The vulcanization of caout- 

 chouc is accompanied by a change from the metastable form of 

 the natural caoutchouc to a stable form, a change which is ac- 

 companied by the aliove mentiojjed difiference in solubilit\ be- 

 between the hydrochlorides of the natural caoutchouc and of the 

 caoutchouc obtained by desulphurizing the vulcanized product. 

 In chemical structure both forms are apparently identical, al- 

 though the stalile form is more slowly attacked by ozone, and in 

 their solubility relationships they behave very differently. The 

 desulphurized vulcanization product cannot again be satisfactorily 

 vulcanized. This is not due to the extraction by the acetone of 

 a substance which favors the vulcanization, as Harries bad pre- 

 viously supposed, but rather to the fact that a regeneration of 

 the caoutcliouc or reconversion to the metastable form is an 

 essential [.reliminary to revulcanization. Theoretically, the de- 

 vulcanization is liut a secondary consideration. 



Irockss 



LABORATORY APPARATUS. 



AUTOMATIC PIPETTE. 



Ai\ automatic pipette for which Alexander Lowy, of the Com- 

 mercial High School, r.rookljn, New York, has applied for a 

 patent, is shown in the illustration, as relates to the stop-cock, 

 which is the improved patentable feature. The 

 \alve or stop-cock is placed in the tube. 



With suction applied at end of the tube C 

 the liquid is drawn upward through tube H 

 nitil it just passes the graduation level A B. 

 The opening D is then closed air tight by the 

 thumb and tlie cock rotated 90 degrees, clock 

 wise, establishing connection between H and 

 D through passage F C. The thumb is then 

 released and air pressure forces the exact 

 measured volume of liquid from the pipette. 



The advantages are summarized as follows ; 



1. Automatic control of exact measured 

 volume of liquid in the pipette. 



2. Obviates manipulating the exact volume 

 of liquid c.nce it has passed the graduation mark, placed where 

 the stop-cock meets the lower end of the valve of the pipette. 



3. Permits discharge of exact measured \obiino. 



4. Ease of manipulation. 



An instrument of the bydronieter type has been patented 

 by T. Cockerill. Government Technical Schools, Colombo. 

 Ceylon, for use in testing rubber latex. The graduations 

 are marked in addition to or in place of the specific gravity 

 numbers with the quantity of acid per gallon required to 

 coagulate the latex, and also in some cases the number of 

 ounces of rubber per gallon of tlic latex [British patent 

 No. 100.591.1 



CHEMICAL TREATMENT OF RUBBER. 



THE UNITED STATES. 



M-XKiNT, C.\oi;tcholc-Likk SunsT.\.N-CEs.— The 

 ])rocess consists in ])roducing substances resembling or related 

 to caoutchouc by shaking a butadiene hydrocarbon with an al- 

 kali metal and zinc balls in the presence of carbon dioxide and 

 then, when a dark-colored mass has been obtained, adding a 

 further quantity of butadiene hydrocarbon, and allowing poly- 

 merization to proceed, also in the presence of carbon dioxide. 

 I Henry S. .\. Holt, Ludwigshafen, Germany, assignor to I'.adi- 

 sche Analin & Soda Fabrik. Ludwigshafen. Gernian> United 

 .States patent No. 1,192,310.) 



Tire Filler. A composition comprising raw rubber, 34 

 pounds ; infusorial earth, 14 pounds ; rosin oil, one pint ; flour of 

 sulphur, four pounds ; air slaked lime, four ounces ; carbonate 

 of ammonia, two pounds; baking soda, one pound. [Edward L. 

 Sherbondy, Los .Angeles, California, assignor to Aero-Cushion 

 Tire Co.. San Jose, California. United States patent No. 

 1,193,196.1 



CANADA. 



Ki-xovKRi.vc Rubber. .V process for recoveriuj,' rubber con- 

 tained in rubbered falirics, consisting in treating the fabrics 

 with ethane tetrachloride, heating the fabrics during tliis treat- 

 ment, liltering the resulting mass to remove the fabric, adding 

 water to the filtrate and heating it to drive off the water and 

 solvent. [La Compagnee Generale des Caoutchoucs de Tereben- 

 thine, Paris, France. Canadian patent No. 168,727.] 



VuLC-\N-iz.\TiON AcCELER-^TCR. Accelerating the vulcanization 

 of natural or artificial caoutchouc or caoutchouc-like substances 

 by vulcanizing them in the presence of paranitrosodimethyl- 

 aniline or its homologues. [S. J. Peachey, Mancliester, England. 

 Canadian patent No. 168,806.] 



Pl.v.stic Chlorine Deriv-\tive of C.\outciiouc. Same subject 

 matter as British patent No. 1.894 (1915). (See below). (S. J. 

 Peachy, Manchester, England. Canadian patent No. 168,807.] 



THE UNITED KINGDOM. 



l'i,A-TK Materials. Caoutchouc is treated with chlorine to 

 form a plastic or solid material resembling celluloid or leather. 

 The caoutchouc is first dissolved in carbon tetrachloride, or other 

 solvent which does not react with chlorine, and which is a sol- 

 vent for the product to be obtained, hydrocarbons being excluded. 

 This solution, after treatment with chlorine or with a gaseous 

 mixture containing chlorine, is evaporated or distilled. Ehiring 

 chlorination the solution is jacketed with circulating cold water. 

 In an example. SO grams caoutchouc in 1,250 cc. carbon tetra- 

 chloride are allowed to absorb 100 grams of chlorine. Camphor, 

 mineral Tillers, or pigments may be added. [S. J. Peachey. Brit- 

 ish patent No. 1,894 (1915).] 



Cement fcr Applying Shof Soles and Repairing. — The 

 cement is made by melting together 1 pound gutta percha, yi 

 pound caoutchouc, 2 ounces pitch or liitiimen, 1 ounce shellac. 

 anri 2 ounces mineral oil. |R. M nobbie, Avr. British patent 

 No. 4,771 (1915).] 



SWEDEN. 



RiBBER Substitute. Ordinary isoprcne is polymerized by 

 suitable substances at a temperature not above 374 degrees F. 



I Chemical Fabrik Co. Swedish patent No. 40,471.] 



OTHER CHEMICAL PATENTS. 



THE UNITED STATES. 



Am6nel)iirg-on-the- Rhine, 



du Rhoiie. Fr: 

 Prrcess of m.-iniifarturii,g |,1: 

 of cellulose. Feodor Lelima 



Resinous proiiiicts and metliod of producing same. J. 

 McCoy. Wilkinsburgli. assignor to Westingliouse Ele. 

 Mainifacturing Co.. East Pi!|s|,v,rgli— both in Pennsylv 



