Patent GB-663599-A (GB)
Title: Organo-silicon modified alkyd resins and a process for their manufacture
IPC: C08G77/00
Filed: 1949-08-26
Abstract: Organo-silicon modified alkyds are made by condensing one or more silanes of the formula RnSiX4-n, wherein R is an alkyl or monocyclic aryl radical, n has an average value from 0.9 to 2.1 and X is a halogen atom or alkoxy group, by contacting with a polyhydric alcohol having from 2 to 4 hydroxy radicals per molecule, in such an amount that the ratio of silane X radicals to alcoholic hydroxyl radicals is from 0.33 to 0.88 and reacting the product so obtained by heating with one or more polycarboxylic p  acids having 2 or 3 carboxyl radicals per molecule or anhydrides thereof, in such an amount that the ratio of the number of acid functional groups to the sum of the number of alcoholic hydroxyl radicals plus the silane X radicals is from 0.06 : 1 to 1.2 : 1. The preferred silanes are: phenylmethyldichlorosilane, phenylmethyldiethoxysilane, phenyltrichlorosilane, diphenyldichlorosilane and dimethyldichlorosilane, with or without unsubstituted silanes, e.g. tetraethoxysilane and tetrachlorosilane, or trisubstituted silanes of the general formula R3SiX, e.g. phenyltrichlorosilane.  Silanes containing higher alkyl radicals, e.g. octadecyl, or monocyclic aryl radicals, e.g. tolyl and xylyl, may be used in place of the methyl or phenyl substituted silanes.  Aliphatic alcohols specified are: glycerine, glycols and 2,2-bis hydroxy-methyl-1,3-propanediol.  The condensation of the silane and alcohol may be effected at temperatures below 0 DEG  C. to above 300 DEG  C., though traces of HCl and H2SO4 hasten the reaction where alkoxysilanes are employed. The esterification with the polycarboxylic acid is preferably effected at temperatures above 100 DEG  C.  The final product is a soluble thermoplastic resin when all three components are difunctional and a thermosetting resin when at least one of the components is at least trifunctional.  The products may be dissolved in aromatic and aliphatic hydrocarbons, ethers, ketones or combinations thereof.  The resins may be modified by fatty acids such as stearic and linoleic acids, hydroxyl-containing oils such as hydrogenated castor oil, organic resins such as alkyd, modified alkyd and polyvinyl acetate, and phenols such as catechol, resorcinol and hydroquinone.  The resins have good compatibility with resins such as polyvinyl acetate, urea-formaldehyde and aryl-sulphonamide-formaldehyde, and may be used for coating electrical conductors, and as paint vehicles and solutions thereof may be used to impregnate and coat base materials.  In examples: (1) a mixture of phenylmethyldiethoxysilane and phenyltriethoxy silane was reacted with glycerine in the presence of concentrated HCl and the resulting product reacted with phthalic anhydride to give a clear, viscous resin soluble in xylene and methyl-ethyl ketone; (2) the product obtained from phenyl-methyldiethoxysilane, glycerine and phthalic anhydride was dissolved in xylene and methyl-ethyl ketone and a cadmium orange pigment and sorbitan mono-oleate polyoxyethylene (wetting agent) added thereto; (3) a resin formed from the reactants of example (1) was modified by azelaic acid; (4) phenyltriethoxysilane was reacted with trimethylene glycol and maleic anhydride; (7) tetrachlorophthalic anhydride was used instead of the phthalic anhydride of example (2); (8) methyl-trichlorosilane was used in addition to the silanes of example (1); (9) phenylmethyldiethoxysilane and silicontetrachloride were reacted with glycerine and phthalic anhydride; phthalic anhydride was reacted with the products of (10) phenyltrichlorosilane and propylene glycol; (11) diphenyldichlorosilane and 2:2-bis-hydroxymethyl-1 : 3-propanediol; (14 and 15) diphenyldichlorosilane and glycerine; (16) dimethyldichlorosilane and propylene glycol; (17) phenylmethyldiethoxysilane, stearic acid and glycerine; and (19) phenyl methyl dichlorosilane, hydrogenated ricinoleic triglyceride and glycerine; the product of phenyltrichlorosilane and propylene glycol was reacted with (12) succinic anhydride and (13) adipic acid; (18) the product of phenylmethyldichlorosilane and propylene glycol was reacted with trimellitic acid. Specification 583,754 is referred to.