Binder for ceramics

Claim 1

A method for producing a sintered ceramic sheet which comprises molding an aqueous slurry composition which contains a sinterable inorganic powder and 1 to 50% by weight of a water-soluble binder based on the weight of the inorganic powder to a sheet-like form, drying the molded slurry to a green sheet and sintering the green sheet by heating, said water-soluble binder comprising a copolymer of: (A) 5 to 45 mol % of acrylic acid, methacrylic acid or mixtures thereof; (B) 1 to 95 mol % of at least one of vinyl compound represented by the formula (I) or (II) ##STR4## wherein R l is a hydrogen atom or a methyl group and R 2 is an alkyl group having 1 to 18 carbon atoms; ##STR5## wherein each of R 3 , R 4 and R 5 is a hydrogen atom, a methyl group or an ethyl group, and the total number of carbon atoms of R 3 , R 4 and (R 5 ) n is a 2 or less and n is an integer of 0 to 2; and (C) 0 to 54 mol % of at least one α,β-unsaturated carboxylate selected from acrylates and methacrylates containing hydroxyl groups represented by the formula (III) ##STR6## wherein R 6 is a hydrogen atom or a methyl group and R 7 is a hydroxy allsyl group having 2 to 4 carbon atoms; at least 85 mol % of carboxyl groups contained in said copolymer being neutralized with a 6 to 9 carbon atom tertiary amine.

Claim 2

A method for producing a sintered ceramic sheet which comprises molding an aqueous slurry composition which contains a sinterable inorganic powder and 1 to 50% by weight of a water-soluble binder based on the weight of the inorganic powder to a sheet-like form, drying the molded slurry to a green sheet and sintering the green sheet by heating, said water-soluble binder comprising a copolymer of: (A) 5 to 45 mol % of acrylic acid, methacrylic acid or mixtures thereof; (B) 1 to 95 mol % of at least one of vinyl compound represented by the formula (I) or (II) ##STR4## wherein R l is a hydrogen atom or a methyl group and R 2 is an alkyl group having 1 to 18 carbon atoms; ##STR5## wherein each of R 3 , R 4 and R 5 is a hydrogen atom, a methyl group or an ethyl group, and the total number of carbon atoms of R 3 , R 4 and (R 5 ) n is a 2 or less and n is an integer of 0 to 2; and (C) 0 to 54 mol % of at least one α,β-unsaturated carboxylate selected from acrylates and methacrylates containing hydroxyl groups represented by the formula (III) ##STR6## wherein R 6 is a hydrogen atom or a methyl group and R 7 is a hydroxy allsyl group having 2 to 4 carbon atoms; at least 85 mol % of carboxyl groups contained in said copolymer being neutralized with a 6 to 9 carbon atom tertiary amine.