William Howard Taft

“ But after full consideration of all the doubt-giving circumstances we do not think that the attack on Weiss' proof of February 10, 1919, as the date when he first discovered by a completed experiment the successful use of D. P. G. as an accelerator in making rubber, has overcome the evidence given to support it and the presumption of its correctness from the patent itself.
Second. Kratz's discovery-Dr. Kratz had been engaged in the chemistry of rubber and in its manufacture for more than seven years. ”

“ A very old and well known proportion has been 50 parts of rubber, 45 parts of zinc oxide and 5 parts of sulphur and is the one shown in the specification of the patent. The mixture is 'cured' by subjecting it to heat to make the vulcanized rubber of commerce. Platen molds have to be provided for giving the desired form to the rubber vulcanized. Steam has to be supplied for heating the molds and the rubber mix, during the 'cure.' A 'cure' is the successful completion of the chemical union or vulcanization of the rubber with the sulphur. ”

“ Under section 4886, Revised Statutes (35 USCA § 31; Comp. St. § 9430) , a person who claims to have invented any patentable improvement is not to be denied a patent because of any printed publication subsequent to his discovery, unless there was publication or public use or sale more than two years prior to his application. Kratz's article was not printed until less than two years before Weiss' application for a patent in November, 1921, and therefore the paper could not be used as a basis for defense against his patent if his discovery was earlier than the publication. ”

“ It is known that when certain organic substances are added to the rubber mix during the compounding, a catalytic or similar action is produced which causes the rubber or similar gum to unite or react more rapidly and thorougly with sulphur or other vulcanizing agents.' The patentee continues:
'I have discovered that disubstituted guanidines, particularly diphenylguanidine, is particularly effective for this purpose.' (This substance is indicated by the formula given in the patent.) ”

“ Inorganic substances like lime or litharge were originally employed as such, but it was subsequently found that certain organic substances were more powerful or more 'active' as the term is, and they came into more general use. The heat to which the rubber mixed with sulphur is subjected has a deleterious effect upon the substance of the raw rubber, and the longer the heating, the greater the injury. An accelerator, as it lessens the time of the cure, not only increases the output of the equipment used but reduces the danger of deterioration of the product. ”

“ The first is the effect of that part of it devoted to Weiss' discovery and his reduction to practice. The second is that part devoted to Kratz's discovery and his reduction to practice.
First. It is contended by the petitioner that the file wrapper and evidence show that the patent was secured by false evidence and is not entitled to the presumption of validity which ordinarily accompanies the grant. The examiner in the Patent Office three times rejected the Weiss application, the third time by a reference to the Kratz paper. ”

“ He had directed his efforts to the subject of vulcanization almost exclusively, and was intimately familiar with the commercial practice therein. His first work with accelerators was as research chemist in 1913. On April 1, 1914, he went with the Norwalk Company in the capacity of chemist, and in April, 1917, he became chief chemist of the Falls Rubber Company.
In 1916, while with the Norwalk Company, Kratz prepared D. P. G. and demonstrated its utility as a rubber accelerator by making test slabs of vulcanized or cured rubber with its use. ”

“ A composition of matter is reduced to practice when it is completely composed. Walker on Patents, § 141a; Hunter v. Stikeman, 13 App. D. C. 214, 226; Mason v. Hepburn, 13 App. D. C. 86, 92; Lindemeyer v. ”