NOVKMBER 1, 1911.] 



THE INDIA RUBBER WORLD 



75 



A New Use for Pontianak Resin. 



EVER since the extraction of rubber from Pontianak has as- 

 sumed any commercial importance there have been many 

 attempts to find an outlet for the tons of residual resin 

 that have accumulated. A small market was formed with the 

 manufacturers of roofing papers. There was also an attempt to 

 utilize it in lieu of chicle for chewing gum. It remains for Carle- 

 ton Ellis, however, of Montclair, New Jersey, to adapt it to a use 

 which would appear to be very large. Under date of August 1, 

 1911, Mr. Ellis was granted two patents, the first 999,493 covers 

 the waterproofing of concrete with Pontianak resin. His second 

 patent of the same date, 999,708, which is for a paint or 

 priming for concrete, may have very far-reaching results. To be- 

 gin with, Mr. Ellis is a chemist and an expert on waste resins. 

 He therefore was able to turn the untractable unsaponifiability of 

 Pontianak to good account by producing a paint vehicle which 

 is not attracted by cement alkali. In other words, he gives some- 

 thing so much better and more lasting than linseed oil that its 

 use is assured. His essay on the subject, although addressed to 

 the examiners of the United States Patent Office, is so complete 

 that we quote : 



"Concrete made from Portland cement is ordinarily rather por- 

 ous and lacking in waterproof qualities ; also it has a grayish 

 brown tint as usually prepared which, for certain purposes is not 

 desired. The cement used in the concrete contains a considerable 

 amount of alkali in the form of free lime, or lime in loose com- 

 bination; also potash or soda in basic form. In addition, bodies 

 of a more or less water soluble nature are present and these 

 compounds, under the action of moisture, tend to migrate from 

 the interior of the concrete mass and appear on the surface there- 

 of as a white efflorescence known by the artisan as 'saltpeter' or 

 lime stains. These are very unsightly and often greatly injure 

 the appearance of buildings, such as dwelling houses constructed 

 of solid or monolithic concrete and stucco. Moreover, the sur- 

 face of concrete often undergoes a slight disintegration, known 

 as checking, which renders the surface imsightly, so for these and 

 other reasons, concrete surfaces frequently need to be painted. 



"The basis of ordinary paint, linseed oil, is not adapted for use 

 in the painting of concrete. Linseed oil, being a readily saponifi- 

 able oil, is afTected by the alkalis of the cement and perishes 

 rather rapidly. With the idea of overcoming these difficulties, 

 proposals have been made to treat the surface of the concrete, 

 prior to painting, with an acid, or neutralizing wash, such as aque- 

 ous solutions of hydrochloric and sulfuric acids, zinc sulfate, am- 

 monium carbonate and the like. In addition to the time required 

 to apply such a wash, the work has to be delayed in order to per- 

 mit the water to dry out before the paint is applied and the sur- 

 face of the cement, because of such drastic acid treatment, is 

 oftentimes more or less disintegrated, the bonding of the cement 

 is in a measure destroyed, especially at the surface, leading to 

 scaling and checking. This action is enhanced by the action of 

 frost in winter and may lead to a very great deterioration of the 

 painted surface. Then too, there is always danger that alkalis 

 from the interior of the cement mass may find their way to the 

 surface of the mass and affect the paint coating by saponifying 

 action ; for the neutralizing action of the acid wash is only super- 

 ficial at best, leaving the interior of the cement with its full quota 

 of unneutralized alkali. For this and other reasons linseed oil 

 has not found favor in the painting of concrete. 



"Solutions of ordinary varnish gums, such as Manila or kauri 

 copal in turpentine and other solvents have also been suggested, 

 but these also are saponifiable to a very considerable degree and 

 are open in a large measure to the same objections noted in the 

 case of linseed oil. 



"My invention has to do with paint vehicles which essentially 



are substantially free from binding materials affected by the alka- 

 lis of cement, and comprises the use of resins, or resinous ma- 

 terials extracted from rubber gums and in particular the rubber 

 gum known as jelutong. 



"Different qualities of jelutong are known in the trade, accord- 

 ing to the source from which they are derived, as Palembang 

 (Sumatra), Pontianak (Borneo), Sarawak and the like. Com- 

 mercial jelutong is obtained by coagulating the latex derived from 

 the jelutong tree. Commercial jelutong contains roughly about 

 70 per cent, water, and 30 per cent, solid material, the latter 

 consisting of about one-third rubber and two-thirds resin, so 

 that for about each pound of rubber recovered, about two 

 pounds of resin are obtained. The resin has found but few 

 uses, and has constituted a waste, or by-product of considerable 

 magnitude. 



"The process of deresination as now practiced by the aid of 

 solvents, leaves the resin in the form of a mass of white particles, 

 or friable lumps, usually containing some moisture and the 

 method of treatment for rendering this resin suitable as a basis 

 for concrete paint vehicles, or oils, will shortly be described. 



"Jelutong resin, as for example, Pontianak, is practically un- 

 saponifiable, as I have indicated in U. S. Letters Patent No. 

 900,687 of October 6, 1908. While the resin after melting, is 

 similar in appearance to ordinary colophonium, it is widely 

 different chemically and because of this, unfit for the many uses 

 to which colophonium is adapted. Thus, because of its un- 

 saponifiability, Pontianak rubber resin cannot be used, as is rosin, 

 in the manufacture of soaps, etc. 



"Chute has called attention to the difficulty of utilizing Ponti- 

 anak rubber resin (India Rubber World, July 1, 1909), and has 

 given some data as to the properties of this resin. His data as 

 to the solutions of this resin coincide to a considerable extent 

 with my own observations, except that no mention has been made 

 by Chute of the instability of many of the solutions of resin. 

 When first prepared, clear solutions are readily obtained, as, for 

 example, by melting one part of Pontianak rubber resin and 

 thinning with two parts of petroleum naphtha. Such a clear 

 solution is, however, supersaturated and on keeping for a few 

 weeks or months or even longer, separation of the less soluble 

 portion occurs spontaneously and the former clear solution 

 becomes largely a grayish paste, or solid mass. Most common 

 solvents act in this way as the following tabulation indicates : 

 For example, a clear liquid mixture made from equal parts of 

 Pontianak resin and pine oil, on standing for a considerable 

 period becomes solid; with one part resin and two parts pine 

 oil, it is about one-half solid ; with one part resin and one part 

 each of pine oil and solvent naphtha, nearly solid. Nearly 

 solid products are produced on standing by mixing two parts of 

 Pontianak resin with one part each of pine oil and heavy benzin, 

 two parts of the resin to one part pine oil and two parts of 

 heavy benzin, also two parts resin to two parts each of these 

 solvents give like results. Light benzin (varnish maker's 

 benzin), with pine oil in varying proportions, acts in the same 

 way. Equal parts of the resin and spirits of turpentine solidify 

 as do mixtures composed of three and four parts of turpentine 

 to two parts of resin. Mixtures of turpentine, with light and 

 heavy benzin behave in a similar manner. Mixtures, of pine oil, 

 solvent naphtha and heavy benzin are but little better as solvents. 

 Good quality solvent naphtha alone, is somewhat better. How- 

 ever, two parts of the resin, with one and one-half, two and two 

 and one-half parts of ordinary crude solvent naphtha solidify 

 completely, three parts of solvent naphtha is nearly solid, while 

 three and one-half and four parts of the solvent yield three- 

 quarters solid and one-quarter liquid. Two parts resin to three 



