GB643964A - Improvements in or relating to the bonding of abrasive bodies by means of synthetic resins - Google Patents

Abstract

An organo-silicon oxide polymer or copolymer is used to bond abrasive grains together in making abrasive articles. The polymers are prepared by the hydrolysis of organosilicon halides or alkoxylates, alone or in admixture with organic orthosilicates, e.g. phenyl orthosilicate, hexa-ethyl di-siliconate; silicon tetra-acrylates, e.g. silicon tetra-formate, tetracetate, tetra-butyrate or disilicon hexaacetate; or silicon halides, e.g. silicon tetrachloride, or disilicon hexa-chloride. Various kinds of hydrocarbon substituent are specified. Polymers substituted by different groups, e.g. methyl and butyl, may be used, or internal plasticization may be effected by using a mixture of a cetyl derivative with, e.g. a methyl derivatives. There may also be used as bonding materials mixtures of organo-silicon oxide polymers with other synthetic resins, e.g. phenol-aldehyde, aniline-aldehyde, acetoneformaldehyde, urea-aldehyde, melamine-aldehyde, alkyd, coumarone, vinyl, styrene, and poly-acrylate resins. For incorporation with urea-aldehyde type resins, e.g. those produced from formaldehyde and urea, thiourea, dicyandiamide, guanidine, alkyl-urea or thiourea, biguanide, or phenyl urea, there may be used organo-silicon acylates of the general formula RxSi(OH)y(OR11)z, where R is a hydrocarbon radical, R11 is an acyl radical, x is a number less than 4, y+z=4-x, or those of the formula RxSi(OR11)4-x. As an alternative, alkyl alkoxy silicons of the formula RxSi(OH)y(OR1)z, o RxSi(OR1)4-x, where x is less than 4, y+z=4-x, and z is not zero may be used. Such silicon derivatives may also be incorporated with resins prepared from aldehydes and amino-triazines, polyamino-triazines, amino-diazines, polyamino-diazines, amino-diazols, and polyaminodiazols. Many such silicon compounds and triazines are specified. Abrasive grains specified are emery, corundum, fused alumina, silicon and other carbides, quartz, glass, diamonds, flint, garnet, carborundum, sandstones, tripoli, and volcanic dusts. They may first be coated with a non-polymerizable liquid silicon derivative before being bonded by the hardenable derivative. The polymers are employed in solution in hexane, benzene, toluene, ethers, esters, alcohols, phenol, cyclohexanol, glycol ethers, and toluene. In examples: (1) a mixture of alumina grit and methyl and butyl silicon hydroxides (obtained by hydrolysis of the corresponding halides) is moulded at 175 DEG C. and 5000 lbs. sq. in. pressure; (2) fused alumina particles are projected on to paper coated with ethyl and butyl silicon hydroxides dissolved in toluene, the coating is dried, and after a second application of solution the paper is heated to cure the binder. Mixed resins are produced by (3) refluxing together dimethylol urea, butanol, and the hydrolysis product of an amyl silicon bromide; (4) refluxing together dimethylol urea, ethyl ethane orthosilicate (C2H5Si (OC2H5)3), butanol, and ethylene glycol monobutyl ether; (5) refluxing together melamine, formaldehyde, amyl alcohol and methanol, distilling off water and methanol, adding the hydrolysis product of an amyl silicon halide and more amyl alcohol and reacting further; (6) procedure as in (5) with urea added to the melamine. The Specification as open to inspection under Sect. 91 comprises also the use of solutions of the organo-silicon polymers and their compositions with other synthetic resins as lacquers, particularly for forming protective coatings on articles or films of cellulose derivatives and synthetic resins, e.g. ethyl cellulose, cellulose acetate, cellulose aceto butyrate, polymethyl methacrylate vinyl acetate/vinyl chloride copolymers, vinyl chloride/vinylidene chloride copolymers, and polystyrene. The silicon polymer is cured on the surface of the plastic by catalysts or by applying radiant heat. A flexible sheet of synthetic resin, and an article of wood, metal or glass coated with synthetic resin, each carrying an outer coating of an organo-silicon polymer are illustrated. There is also described in examples the reaction of Grignard compounds with silicon oxychloride (Si2OCl6) followed by hydrolysis to yield organo-silicon polymers stronger than those prepared from silicon tetrachloride. Other examples describe reacting (17) an ethyl butyl silicon hydroxide, a melamine aldehyde resin and amyl alcohol; (18) ethyl ethane orthosiliconate, melamine - aldehyde resin and butanol; (19) the hydrolysis product of a diethyl silicon halide and acetic anhydride, followed by reaction with a melamine-aldehyde resin in amyl alcohol solution. The subject-matter of Specifications 635,194 and 644,282 are also included. This subject-matter does not appear in the Specification as accepted.ALSO:An organo-silicon halide is prepared by reacting an organo magnesium halide or mixtures thereof, with silicon tetrachloride and may be hydrolysed alone or in admixture with silicon tetrachloride to yield the corresponding hydroxides or their condensation products. Organic radicals mentioned are methyl, n-butyl, n-amyl, and alphyl, aryl, alkynyl, alkenyl, aralkyl, olefinyl, and carbocylic radicals. For use in place of silicon tetrachloride are mentioned disilicon hexa-chloride, disilicon hexa-acetate, hexa-ethyl disiliconate, methyl-, ethyl-, butyl-, and phenyl-orthosilicates, and acylates, e.g. silicon tetraformate, silicon tetra-acetate, and silicon tetrabutyrate. The products of hydrolysis are used as binders for abrasives (see Groups IV (a) and XXIII). The Specification as open to inspection under Sect. 91 comprises also the subject-matter of 635,194. This subject-matter does not appear in the Specification as accepted. p