Mineral-resin matrix

Claim 2

A material for use in the molding or pressing of articles which comprises in admixture a crystallizable glass which is made in a rotary kiln and comprises numerous bubbles and is ground in such a manner that numerous cavities are formed on the surfaces of the particles by cleavage of the bubbles and comprises fractions of relatively fine-grained material having a particle size of up to 250 μm and fractions of coarser particles having a particle size of from 250 to 5000 μm, wherein the particles of the relatively fine-grained material have been subjected to an intimate mixing treatment in the presence of an organic binder thereby to essentially distribute the binder in the form of a coating on the rough surface of the particles of the relatively fine-grained material, and wherein said coated particles are distributed among the coarser particles.

Claim 3

A molding material according to claim 1, wherein the mixing treatment is a ball mill grinding.

Claim 4

A molding material according to claim 1, wherein the organic binder is a thermosetting resin.

Claim 5

A molding material according to claim 3, wherein the binder is selected from the group consisting of phenol formaldehyde resins, epoxy resins, melamine resins, urea formaldehyde resins and urethane resins.

Claim 6

A molding material according to claim 1, wherein the material further contains fibres of mineral, vegetable or synthetic origin.

Claim 7

A molding material according to claim 1, wherein the content of coarser particles amounts to 25 to 75% by weight of the total mixture.

Claim 8

Molded article prepared by subjecting the material according to claim 1 to a molding or pressing in a mold thereby to cause the binder to cure and form with the finer particles a matrix binding together the coarser particles.

Claim 9

Process for the preparation of a material for use in the molding or pressing of articles which comprises (a) grinding a crystallizable glass material which is made in a rotary kilm and comprises numerous bubbles to particles having numerous cavities on its surface by cleavage of the bubbles and comprising fractions of relatively fine-grained material having a particle size of up to 250 μm, and fractions of coarser particles having a particle size of from 250 to 5000 μm (b) subjecting a predetermined amount of said fractions of fine-grained material particles and an organic binder to an intimate mixing treatment thereby to essentially distribute the binder in the form of a coating on the rough surface of the particles, and (c) admixing a predetermined amount of said coarser particles with said coated finer particles thereby to distribute the finer particles among the coarser particles and form a moldable material.

Claim 10

Process for the preparation of a material for use in the molding or pressing of articles which comprises (a) grinding a crystallizable glass material which is made in a rotary kilm and comprises numerous bubbles to particles having numerous cavities on its surface by cleavage of the bubbles and comprising fractions of relatively fine-grained material having a particle size of up to 250 μm, and fractions of coarser particles having a particle size of from 250 to 5000 μm (b) subjecting a predetermined amount of said fractions of fine-grained material particles and an organic binder to an intimate mixing treatment thereby to essentially distribute the binder in the form of a coating on the rough surface of the particles, and (c) admixing a predetermined amount of said coarser particles with said coated finer particles thereby to distribute the finer particles among the coarser particles and form a moldable material.