Patent GB-937619-A (GB)
Title: Method of producing ceramic articles
IPC: C04B33/13
Filed: 1960-08-22
Abstract: A moulding material for producing ceramic articles consists of a ceramic powder, e.g. 82-90%, such as oxides of Al, Be, Ca, Mg, Te, Th, Ti, Y, Zr, sinterable silicates of aluminium, mullite, sillimanite, clay or mixtures thereof, and a duroplastic or thermosetting synthetic binding agent free from plasticizers, e.g. 18-10%, which decomposes on heating at below the sintering temperature of the ceramic mass, e.g. during firing of the moulded article. Preferred duroplasts are polyesters of reticular structure, e.g. a condensation product of maleic acid and ethylene glycol saturated with styrene, phenoplasts, epoxy resins, aminoplasts, and they may be mixed with benzoylperoxide (a 50% paste), zinc stearate or a cobalt salt solution or mixtures thereof.  To increase the decomposition temperature of the duroplast to preferably just below the sintering temperature of the moulding material, e.g. to 750 DEG C., 10% of allyl methacrylate may be added with or without a perchlorinated aliphatic hydrocarbon and Sb2O3 for making non-inflammable duroplasts. Injection-moulding may be effected. Prior art discloses a moulding material composed of 82-89% ceramic material and 18-11% plastic binding agent comprising 3-7% artificial thermoplastic resin, such as cellulose ethyl resin, 2,5-7% shellac and 3-9% plastifier which evaporates or sublimes below the softening-point of the thermoplasts.  Specified thermoplasts are cellulose-ethyl resin, cellulose-acetate, methyl methacrylate, vinyl derivatives, polyvinyl acetate, polystyrol or polymerization products of the monomers diallyl phthalate, di-allyl carbonate, triallyl cyanurate.  Specified plastifiers are n-butyl-stearate stearic acid, triphenyl-phosphate, phthalic anhydride acid, glycerin, o-cresol, dibutyl-phthalate, triccresyl phosphate or glycerine-tripropionic acid ester.ALSO:A moulding material for producing ceramic articles consists of a ceramic powder e.g. 82-90%, such as oxides of Al, Be, Ca, Mg, Te, Th, Ti, Y, Zr, sinterable silicates of aluminium, mullite, sillimanite, clay or mixtures thereof, and a duroplastic or thermosetting synthetic binding agent free from plasticisers, e.g. 18-10%, which decomposes on heating at below the sintering temperature of the ceramic mass e.g. during firing of the moulded article.  Preferred duroplasts are polyesters of reticular structure, e.g. a condensation product of maleic acid and ethyleneglycol saturated with styrene, phenoplasts, epoxy resins, aminoplasts, and they may be mixed with benzoylperoxide (a 50% paste), zinc stearate or a cobalt salt solution or mixtures thereof.  To increase the decomposition temperature of the duroplast to preferably just below the sintering temperature of the moulding material, e.g. to 750 DEG C. 10% of allyl methacrylate may be added with or without a perchlorinated aliphatic hydrocarbon and Sb2O3 for making non-inflammable duroplasts.  Injection-moulding may be effected. Prior art discloses a moulding material composed of 82-98% ceramic material and 18-11% plastic binding agent comprising 3-7% artificial thermoplastic resin, such as cellulose ethyl resin, 2,5-7% shellac and 3-9% plastifier which evaporates or sublimes below the softening-point of the thermoplasts.  Specified thermoplasts are cellulose-ethyl resin, cellulose-acetate, methyl methacrylate, vinyl derivatives, polyvinyl acetate, polystyrol or polycondensation products of monomers diallyl phthalate, diethylene, glycol, di-allyl coarbonate, triallyl cyanurate. Specified plastifiers are n-butyl-stearate, stearic acid, triphenolphosphate, phthalic anhydric acid, glycerin, o-cresol, dibutyl-phthalate, tricresyl phosphate or glycerine-tripropionic acid ester.