Cellulose ether composition for the extrusion of mineral shaped bodies and also a process for the extrusion of mineral shaped bodies using this cellulose ether composition

1. Process for the extrusion of mineral masses, comprising

admixing 0.1 to 6% by weight of a cellulose ether composition which comprises 90.1 to 99.8% by weight of cellulose ether and 0.2 to 9.9% of a superabsorbent polymer selected from the group consisting of partially neutralized and crosslinked polyacrylic acids, (partially) neutralized starch-acrylic acid graft copolymers, (partially) saponified vinyl acetate-acrylic ester copolymers, and polymers of crosslinked cationic monomers, and optionally other additives with a mineral mixture comprising 20 to 100 parts of mineral binder, 0 to 70 parts of aggregates, 0 to 30 parts of lightweight aggregates, 0 to 20 parts of fibres and optionally other additives, and water,

mixing and/or kneading until a homogeneous mass is obtained, and

extruding the mass through a die mouth of an extrusion press, with the proviso that the extruded mineral extrusion mass does not comprise a polyacrylamide.

2. The process of claim 1 , wherein the cellulose ether composition comprises ionic cellulose ethers selected from the group consisting of carboxymethylcellulose, sulphoethylcellulose and salts thereof or comprises a non-ionic cellulose ethers selected from the group consisting of methylcellulose, methyl hydroxyethylcellulose, methyl hydroxypropyl-cellulose, hydroxyethylcellulose, ethyl hydroxyethylcellulose, methyl ethyl hydroxyethylcellulose, methyl hydroxyethyl hydroxybutylcellulose and mixtures thereof.

3. The process of claim 1 , wherein the superabsorbent polymer is crosslinked and swellable but insoluble in water.

4. The process of claim 1 , in which the mineral masses are cement-bonded, gypsum-bonded, dry hydrated lime-bonded, silicate-bonded, fly ash-bonded, clay-bonded or ceramic masses.

5. Process according to claim 1 , further comprising maintaining the temperature of the mass to be extruded at the die mouth from 30 to 65° C.

6. The process of claim 1 wherein the extruded mineral mass comprises

0.1 to 6% by weight of said cellulose ether composition,

20 to 100 parts of a mineral binder,

0 to 70 parts aggregates,

0-30 parts light weight aggregates,

0-20 parts of fibers and water.

7. The process of claim 2 , wherein the superabsorbent polymer comprises a partially neutralized and crosslinked polyacrylic acid.

8. The process of claim 4 wherein the superabsorbent polymer comprises a partially neutralized and crosslinked polyacrylic acid.