HARRY I. FISHER National Research Council, Washington, D. C.
TEE expression, "Rubber plus chemistry" is in typical chemical language. Perhaps I should add to it, "equals what?" Suppose I try to make a real equation of it. Then the "what" becomes a multitude of answers; in fact, as in organic chemistry the equation is seldom simple, since an organic reaction generally leads to many things. That is one reason why it is so interesting. This paper is an attempt to present some of the answers. Rubber minus chemistry was making a little headway in the early part of the last century, 150 years ago. Even as early as 1791 Samuel Peal in England obtained the first known rubber patent, a patent for the waterproofing of fabrics. Also, raw rubber was known for its property of rubbing out pencil marks-whence its name. Kevertheless, it must be remembered that the name, contrary to some statements, evidently had been given it before Priestley in the preface of one of his books (1770) wrote, "I have seen a substance excellently adapted to the purpose of wiping from paper the marks of a black lead pencil." He recommended its use "to those who practice drawing," and told where it could be bought. Katives in South America made rubber overshoes by dipping clay forms into latex. Five hundred pairs mere imported from Brazil into Boston in 1823 and sold. Thomas Hancock in England cut strips of rubber from imported raw rubber shoes and bottles for use in making tobacco pouches and elastic fabric containing threads of rubber. In a patent, "Enrolled August 8, 1820," he describes how he applies his 'Lcaoutchoucspring," that is, elastic fabric, for use "in the wrist of the glove," and "the mouth of pockets, to prevent their contents from falling out when in an inverted position, and to prevent their being easily picked; . . . to braces, instead of wire and other springs, . . . to stockings, to prevent their slipping down the leg; . . . to wigs, fake curls and fronts, to keep them tight on the head"; and for many other purposes. Hancock had plenty of imagination. In order to use up his waste cuttings, it occurred to him that, "if minced up very small, the amount of fresh-cut surface would be greatly increased, and by heat and pressure might possibly unite sufficiently for some purposes." He "thought that a tearing action might do better than simply cutting." The machine he made for this purpose consisted of a spiked roller that revolved in an internally spiked hollow cylinder, which was the forerunner of masticators, because cuttings worked in it "came out a round solid ball." He continues in his "Personal Narrative," "I wish here to re~ ~h t ~ , Address at the ~ ~ the ~ d~ i chemical tory, University of Akron, Ohio, January 18, 1951.
mark that the discovery of this process was unquestionably the origin and commencement of the india-rubber manufacture, properly so called." This was in the summer of 1820. Masticated rubber increased its usefulness a great deal both as solid rubber in sheets, thread, etc., and also by means of solutions. Charles Macintosh in 1823 invented his double-texture garments and shortly Hancock used his solutions similarly. At this same time Hancock obtained a British patent for saturating fabric with rubber latex. In 1828 Johann Nepomuk Reithofer in Vienna took out a patent for making elastic fabric containing rubber thread cut from raw rubber, and in 1829 a similar process led to the founding of the first German factory for making elastic fabric in Finstenvalde near Berlin. In 1833 the Roxbury India Rubber Factory was established in Roxbury, I\lassachusetts, the first company organized in this country, to manufacture clothing, shoes, and other articles. Three years later Edwin M. Chaffee obtained a United States patent for the application of undissolved rubber to cloth and leather and for theprocessingmachinery, whichwas thefrictioncalender. Charles Goodyear, a hardware merchant and an inventor, the son of Amasa Goodyear, a Connecticut hardware merchant and inventor, became interested in rubber, as he tells us in his book, "Gum Elastic," when "he was passing the store of the Roxbury India Rubber Company, in New York, and stopped to make inquiry about life-preservers, with the view of purchasing one." Later he returned with an improved tube for inflating life-preservers, and "being pleased with his success in that, the agent advised him to turn his attention to the improvement of India rubber, and said, in behalf of the company, he would insure a very large compensation to any one who would overcome the great difficulties they met with in the manufacture, which were, great adhesiveness and subsequent decomposition of the goods." Goodyear soon learned of the difficulties encountered by others, especially that "India rubber manufacturers had always been careful to avoid a heat of more than 100 degrees of Fahrenheit in the manufacture of their wares; and in the case of the Macintosh goods, their circulars cautioned customers not to approach too near the fire with them." In his attempts to get rid of the adhesiveness of rubber he became much elated with the combination of rubber and magnesia. The magnesia appeared to dry the rubber just as other substances dry paints. Of especial interest was the fact that the rubwas rubber ~ ~ i whereas ~ ~ berb ~product ~ ~ white ~ manufactured ~ goods were all black. Several years later he wrote, "A 328
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