Polyurea polyurethane foamed sponge with high wet strength
AssigneeW. R. Grace & Co.
InventorsGlenn E. Fulmer, Conrad Vollmerhausen
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Abstract
An open cell polyurea polyurethane foamed sponge is produced by mixing together a resin and an aqueous pahse. The resin phase consists of a prepolymer made from a hydrophilic oxyalkylene polyol which is capped with isocyanate groups and from about 1-30% by weight of the prepolymer of a polymeric polysocyanate such as a PAPI resin. The aqueous phase contains water, reinforcing fibers, surfactants, a thickening agent and preferably up to 40% by weight of diatomaceous earth. The resulting foam has a reduced volume swell, rapid wet out and improved wet strength.
Claims16
In a foamed sponge made by mixing together
- (a) a resin phase comprising a prepolymer of a hydrophilic oxyalkylene polyol which is capped with isocyanate groups, and
- (b) an aqueous suspension containing fibers and at least one surfactant, the improvement comprising adding to the mixture prior to foam formation
- (i) from about 1-40% by weight of the prepolymer of part (a) of a polymeric polyisocyanate selected from the group consisting of 4,4'-diphenylmethane diisocyanate, and a mixture of 4,4'-diphenylmethane diisocyanate and polymethylene polyphenylisocyanates, said mixture having an average functionality of about 2.0 to 3.0, and
- (ii) from about 0-40% by weight of the aqueous suspension of part (b) of diatomaceous earth,
- whereby an open cell foamed sponge is obtained having a reduced volume swell, rapid wet out and improved wet strength.
In a method of making a foamed sponge by mixing together
- (a) a resin phase comprising a prepolymer of a hydrophilic oxyalkylene polyol which is capped with isocyanate groups, and
- (b) an aqueous suspension containing fibers and at least one surfactant, the improvement comprising adding to the mixture prior to foam formation
- (i) from about 1-40% by weight of the prepolymer of part (a) of a polymeric polyisocyanate selected from the group consisting of 4,4'-diphenylmethane diisocyanate, and a mixture of 4,4'-diphenylmethane diisocyanate and polymethylene polyphenylisocyanates, said mixture having an average functionality of about 2.0 to 3.0, and
- (ii) from about 0-40% by weight of the aqueous suspension of part (b) of diatomaceous earth,
- whereby an open cell foamed sponge is obtained having a reduced volume swell, rapid wet out and improved wet strength.
A method of making a foamed sponge by mixing together
- (a) a resin phase comprising a prepolymer of a hydrophilic oxyalkylene polyol which is capped with isocyanate groups, and from about 1-40% by weight of said prepolymer of a polymeric polyisocyanate selected from the group consisting of 4,4'-diphenylmethane diisocyanate, and a mixture of 4,4'-diphenylmethane diisocyanate and polymethylene polyphenylisocyanates, said mixture having an average functionality of about 2.0 to 3.0, and
- (b) an aqueous suspension comprising water, at least one surfactant, and about 0-40% by weight of diatomaceous earth,
- whereby an open cell foamed sponge is obtained having a reduced volume swell, rapid wet strength and improved wet strength.
Dependencies are inferred from the claim text.