摘要 |
<p>546,373. Adhesives. RESINOUS PRODUCTS & CHEMICAL CO. July 3, 1941, No. 8413. Convention date, Aug. 15, 1940. [Class 2 (iii)] An adhesive comprises a solution of a condensate of a bisthioammeline polyalkylene ether described in Specification 541,025 and formaldehyde, together with an acid type catalyst for hardening the condensate, and soluble blood. The bisthioammeline polyalkylene ethers used, have the formula :- wherein A represents a lower alkylene group of two to four carbon atoms, and N is an integer from one to five inclusive, and these may be condensed with the formaldehyde, with or without the addition of one or more other methylol-forming compounds such as urea, thiourea, alkyl ureas, phenyl urea, urethane, formamide, acetamide, aryl sulphonamides, dicyandiamide, phenol or melamine. In conjunction with the formaldehyde, other aldehydes, such as benzaldehyde, acetaldehyde or furfural may be used. Specified hardening catalysts are hydrochloric, phosphoric, acetic, formic, lactic, phthalic, maleic and chloroacetic acids, methylamine hydrochloride, sodium acid sulphate, barium ethyl sulphate, ammonium thiocyanate, ammonium chloride, ammonium sulphate and alum. The " soluble blood " employed is dried or liquid animal blood in which the protein content has not been coagulated, and at least 90 per cent. of which, in the dry form, is soluble or dispersible in water. The stability of the condensate solution may be improved by the addition of an alkaline earth chloride, e.g. calcium chloride or magnesium chloride. A thickening agent, such as starch, walnut shell flour, rye flour or wheat flour, may be added, and other specified optional additions are diatomaceous earth, alpha cellulose floc and wood flour. Examples are given. Specifications 541,025 and 543,256 are referred to.</p> |