Polyvinyl alcohol composition, process for its preparation and its use

Claim 2

Water-soluble, flowable and thermoplastically workable polyvinyl alcohol composition consisting of (a) 60 to 98 percent by weight of a partially solvolyzed graft copolymer of a vinyl ester and a polyethylene glycol having a molecular weight of from 5,000 to 1,000,000, the viscosity of the 4 percent by weight aqueous solution of the partially solvolyzed graft copolymer being of from 3 to 40 mPa.s (measured at a temperature of 20° C.), (b) 2 to 40 percent by weight of water and

Claim 3

(c) 2 to 20 percent by weight of a polyhydric alkanol having a melting point of from 25° to 100° C.

Claim 4

(c) 2 to 20 percent by weight of a polyhydric alkanol having a melting point of from 25° to 100° C.

Claim 5

The polyvinyl alcohol composition of claim 1, wherein the graft copolymer is a graft copolymer of vinyl acetate and a polyethylene glycol, having from 40 to 80 percent by weight of vinyl alcohol units, 5 to 35 percent by weight of vinyl acetate units and 10 to 50 percent by weight of ethylene oxide units.

Claim 6

The polyvinyl alcohol composition of claim 1, wherein the polyhydric alkanol is a branched alkanol having from 4 to 10 carbon atoms and 2, 3 or 4 hydroxyl groups, or a polyethylene glycol.

Claim 7

Process for the manufacture of a water-soluble, flowable and thermoplastically workable polyvinyl alcohol composition, wherein (a) 60 to 98 parts by weight of a granular, partially solvolyzed graft copolymer of a vinyl ester and a polyethylene glycol having a molecular weight of from 5,000 to 1,000,000, the viscosity of the 4 percent by weight aqueous solution of the partially solvolyzed graft copolymer being of from 3 to 40 mPa.s (measured at a temperature of 20° C.), (b) 2 to 40 parts by weight of water and (c) 2 to 20 parts by weight of a polyhydric alkanol having a melting point of from 25° to 100° C. are intensely and homogeneously mixed at a temperature of from 20° to 60° C.

Claim 8

Process for the manufacture of a water-soluble, flowable and thermoplastically workable polyvinyl alcohol composition, wherein (a) 60 to 98 parts by weight of a granular, partially solvolyzed graft copolymer of a vinyl ester and a polyethylene glycol having a molecular weight of from 5,000 to 1,000,000, the viscosity of the 4 percent by weight aqueous solution of the partially solvolyzed graft copolymer being of from 3 to 40 mPa.s (measured at a temperature of 20° C.), (b) 2 to 40 parts by weight of water and (c) 2 to 20 parts by weight of a polyhydric alkanol having a melting point of from 25° to 100° C. are intensely and homogeneously mixed at a temperature of from 20° to 60° C.

Claim 9

The process of claim 4, wherein there is used as partially solvolyzed graft copolymer a granular material at least 70 percent by weight of which being particles having diameters in the range of from 0.2 to 3.5 mm.

Claim 10

Water-soluble, flowable and thermoplastically workable polyvinyl alcohol composition consisting of (a) 30 to 95 percent by weight of a partially solvolyzed graft copolymer of a vinyl ester and a polyethylene glycol having a molecular weight of from 5,000 to 1,000,000, the viscosity of the 4 percent by weight aqueous solution of the partially solvolyzed graft copolymer being from 3 to 40 mPa.s (measured at a temperature of 20° C.), (b) 2 to 40 percent by weight of water, (c) 0 to 20 percent by weight of a polyhydric alkanol having a melting point of from 25° to 100° C. and (d) 3 to 60 percent by weight of a partially solvolyzed polyvinyl ester having an ester number of from 50 to 280 mg KOH/g, the viscosity of the aqueous solution of the partially solvolyzed polyvinyl ester being from 3 to 40 mPa.s (measured at a temperature of 20° C.).

Claim 11

Water-soluble, flowable and thermoplastically workable polyvinyl alcohol composition consisting of (a) 30 to 95 percent by weight of a partially solvolyzed graft copolymer of a vinyl ester and a polyethylene glycol having a molecular weight of from 5,000 to 1,000,000, the viscosity of the 4 percent by weight aqueous solution of the partially solvolyzed graft copolymer being from 3 to 40 mPa.s (measured at a temperature of 20° C.), (b) 2 to 40 percent by weight of water, (c) 0 to 20 percent by weight of a polyhydric alkanol having a melting point of from 25° to 100° C. and (d) 3 to 60 percent by weight of a partially solvolyzed polyvinyl ester having an ester number of from 50 to 280 mg KOH/g, the viscosity of the aqueous solution of the partially solvolyzed polyvinyl ester being from 3 to 40 mPa.s (measured at a temperature of 20° C.).

Claim 12

Process for the manufacture of a water-soluble, flowable and thermoplastically workable polyvinyl alcohol composition, wherein (a) 30 to 95 parts by weight of a granular partially solvolyzed graft copolymer of a vinyl ester and a polyethylene glycol having a molecular weight of from 5,000 to 1,000,000, the viscosity of the 4 percent by weight aqueous solution of the partially solvolyzed graft copolymer being from 3 to 40 mPa.s (measured at a temperature of 20° C.), (b) 2 to 40 parts by weight of water, (c) 2 to 20 parts by weight of a polyhydric alkanol having a melting point of from 25° to 100° C. and (d) 3 to 60 parts by weight of a granular partially solvolyzed polyvinyl ester having an ester number of from 50 to 280 mg KOH/g, the viscosity of the 4 percent by weight aqueous solution of the partially solvolyzed polyvinyl ester being from 3 to 40 mPa.s (measured at a temperature of 20° C.) are intensely and homogeneously mixed with one another at a temperature of from 20° to 60° C.

Claim 13

Process for the manufacture of a water-soluble, flowable and thermoplastically workable polyvinyl alcohol composition, wherein (a) 30 to 95 parts by weight of a granular partially solvolyzed graft copolymer of a vinyl ester and a polyethylene glycol having a molecular weight of from 5,000 to 1,000,000, the viscosity of the 4 percent by weight aqueous solution of the partially solvolyzed graft copolymer being from 3 to 40 mPa.s (measured at a temperature of 20° C.), (b) 2 to 40 parts by weight of water, (c) 2 to 20 parts by weight of a polyhydric alkanol having a melting point of from 25° to 100° C. and (d) 3 to 60 parts by weight of a granular partially solvolyzed polyvinyl ester having an ester number of from 50 to 280 mg KOH/g, the viscosity of the 4 percent by weight aqueous solution of the partially solvolyzed polyvinyl ester being from 3 to 40 mPa.s (measured at a temperature of 20° C.) are intensely and homogeneously mixed with one another at a temperature of from 20° to 60° C.

Claim 14

Method for the preparation of a water-soluble shaped article which comprises using as starting material the polyvinyl alcohol composition according to claims 1 or 6.

Claim 15

Sheet, prepared from the polyvinyl alcohol composition according to claims 1 or 6.