GB694716A - Silicon containing alkyd resins - Google Patents

Abstract

An organosilicon-modified alkyd resin is made by heating an alkyd resin, in the presence or absence of a solvent, with the hydrolysate of a silane mixture at least 10 mol. per cent of which consists of (a) a silane of the formula RnSiY(4-n), wherein each R is a methyl or ethyl radical, each Y is a hydrolyzable radical and n is 1 or 2, and (b) a silane of the formula <FORM:0694716/IV (a)/1> wherein A is R or Y and T is a cycloaliphatic radical, the molar ratio of (a) to (b) ranging from 9 : 1 to 3 : 7, and from 0 to 10 mol. per cent of the silane mixture consists of silanes having the formula r3SiY, any additional silanes in the mixture consisting of tetrafunctional silanes and silanes of the formula rmSiY(4-m), wherein m is 1 or 2, and n is a primary or secondary alkyl, aralkyl, aryl or alkaryl radical, each having from 1 to 12 carbon atoms, the amount of any such tetrafunctional silanes being insufficient to reduce the average number of hydrocarbon radicals attached to each silicon atom to below 0.6, and the hydrolysate being as little condensed as possible. A list of hydrolysable radicals is given. The preferred alkyds, which may be oil-modified, are made from glycerol, alone or in admixture with other polyhydric alcohols, and aromatic dicarboxylic acids such as naphthalic, phthalic and iso-, tere-, 4-chloro-and tetrachloro-phthalic acids. The hydrolyzate is preferably made by hydrolysing, with an aqueous base or inorganic acid, the silane mixture in a solvent such as benzene, toluene, xylene, hexane, heptane, octane, or diethyl-, ethylpropyl-, dipropyl- or propylbutyl-ether. Titania may be added to the compositions. In examples: (1) a xylene solution of the hydrolysate of a mixture of ethyl- and cyclohexyl-trichlorosilanes is refluxed with a xylene solution of a short oil-length soyabean oil modified glyceryl phthalate; (2, 3) an ether solution of the hydrolysate of (1) is refluxed with xylene and a coconut oil modified glyceryl phthalate; (4) an ether solution of the hydrolysate of methyl- and cyclohexyl-trichlorosilanes is refluxed with the alkyd solution of (1). The weight ratio of the silicon compound, calculated as completely condensed silane hydrolysate, to alkyd resin may be from 1 : 100 to 20 : 1. Tables are given showing comparative tests, e.g. solvent, caustic and heat resistance, of the resins of the invention with other modified alkyds. Specification 583,754 is referred to. The Specification as open to inspection under Sect. 91 describes p also (a) the preparation of alkyds modified (1) by reaction with abietic (dry distilled rosin), capric, lauric, myristic, palmitic, stearic, palmitoleic, oleic, linoleic, linolenic, elasteostearic, rincinoleic and erucic acids or their esters, such as coconut, palmnut, babussu, murmura, palm, rapeseed, mustard seed, olive, peanut, sesame, corn, cottonseed, soyabean, sunflower, walnut, linseed, perilla, castor, tung, oiticica, whale, menhaden, sardine and herring oils, beef, tallow and lard; (2) by replacing part of the glycerol by ethylene-, propylene, dipropylene-, butylene- or any polymethylene- (from trimethyleneto decylene, e.g., decamethylene-) or polyethylene (from diethyleneto nonaethylene-) glycol, pentaerythritol, dipentaerythritol, mixtures of pentaerythritol with its derivatives, mannitol or sorbitol, (3) by using, in addition, itaconic, citraconic, maleic, fumaric, or mesaconic acid, any acid from oxalic, malonic to sebacic, any cyclohexane dicarboxylic acid, diglycollic, dilactic or resorcinol diacetic acid; benzoic, valeric, butyric, caproic or enanthic acid; (b) the preparation of silanols by hydrolysing ethyldichloro-, diethyldifluoro-, ethyltrichloro-, diethyldichloro-, diethyldiethoxy-, diethylchlorethoxy-, ethyltrimethoxy-, ethyltriethoxy, ethylchlorodiethoxy-, ethyltripropoxy-, ethyltri-n-butoxy-, ethyltriisopropoxy-, dimethylfluorochloro-, methyltriethoxy-, methyltri-n-butoxy-, dimethyldiethoxy-, dimethyldi-n-butoxy-, dimethylchloro-n-butoxy-, cyclohexyl-trichloro-, cyclohexylmethyldichloro-, trimethylcyclohexyltrichloro- and p-tertiaryamylcyclohexyltrichloro - silanes. This subject - matter does not appear in the Specification as accepted.ALSO:The Specification as open to inspection under Sect. 91, describes the preparation of cycloaliphatic silanes by reacting in the vapour phase a cycloalkene (e.g. cyclopentene, cyclohexene or any mono-, di- or trialkyl-substituted derivative thereof in which each alkyl radical has from 1 to 5 carbon atoms and the total number of carbon atoms in all the alkyl radicals is not more than 5) and a halosilane having 1 or 2 hydrogen atoms and 2 or 3 other radicals one of which may be ethyl or methyl and the remainder of which are halogens. The reaction is usually effected at 200 DEG to 400 DEG C. and at about 2000 pounds per square inch. The normal methods of making silanes having the hydrolysable radicals amino, acyloxy, alkoxy and aroxy are described. This subject-matter does not appear in the Specification as accepted.