Use of water soluble electrolytes as additives in aqueous dispersions of synthetic materials and an aqueous dispersion of synthetic materials containing a water soluble electrolyte

Claim 2

A stable aqueous dispersion of a polyurethane which yields films having superior water resistance and/or blocking resistance having chemically fixed anionic groups amounting to 1 to 50 milliequivalents per 100 g and not more than 1.0% by weight of ethylene oxide units chemically fixed within polyester chains, which dispersion has a solids content of from 5 to 65% by weight, characterized by containing 0.01 to 3.0% by weight, based on the solids content, of a water soluble organic or inorganic salt other than an external emulsifier.

Claim 3

A process for improving stable aqueous polyurethane dispersions so that films prepared from these dispersions display superior blocking resistance and/or water resistance comprising incorporating a water soluble organic or inorganic salt other than an external emulsifier into the dispersion medium as follows: (a) about 0.01 to 3.0 wt.%, based on solids, when the dispersed polyurethane has a non-ionic hydrophilic group content of 1.0 wt.% or less, and (b) about 0.01 to 0.4 wt.%, based on solids, when the dispersed polyurethane has a non-ionic hydrophilic group content greater than 1 wt.%, wherein the dispersibility of the polyurethane is due to anionic groups, non-ionic hydrophilic groups, external emulsifiers or a combination thereof.

Claim 4

A process for improving stable aqueous polyurethane dispersions so that films prepared from these dispersions display superior blocking resistance and/or water resistance comprising incorporating a water soluble organic or inorganic salt other than an external emulsifier into the dispersion medium as follows: (a) about 0.01 to 3.0 wt.%, based on solids, when the dispersed polyurethane has a non-ionic hydrophilic group content of 1.0 wt.% or less, and (b) about 0.01 to 0.4 wt.%, based on solids, when the dispersed polyurethane has a non-ionic hydrophilic group content greater than 1 wt.%, wherein the dispersibility of the polyurethane is due to anionic groups, non-ionic hydrophilic groups, external emulsifiers or a combination thereof.

Claim 5

The process of claim 2 wherein between about 0.05 and 0.5 wt.% of an organic or inorganic salt containing ##STR2## groups is utilized as component (a).

Claim 6

The process of claim 2 wherein between about 0.05 and 0.5 wt.% of the water soluble salt of a mineral acid is utilized as the organic or inorganic salt in component (a).

Claim 7

A stable aqueous dispersion which yields films having superior water resistance and/or blocking resistance comprising (a) polyurethane having a non-ionic hydrophilic group content of less than 1.0 wt.% based on solids; (b) sufficient anionic or non-ionic hydrophilic groups chemically incorporated into said polyurethane or sufficient external emulsifier to render said dispersion stable; (c) between about 0.01 and 3 wt.%, based on solids, of a water soluble organic or inorganic salt other than an external emulsifier; and (d) sufficient water to act as the continuous phase of said dispersion.

Claim 8

A stable aqueous dispersion which yields films having superior water resistance and/or blocking resistance comprising (a) polyurethane having a non-ionic hydrophilic group content of less than 1.0 wt.% based on solids; (b) sufficient anionic or non-ionic hydrophilic groups chemically incorporated into said polyurethane or sufficient external emulsifier to render said dispersion stable; (c) between about 0.01 and 3 wt.%, based on solids, of a water soluble organic or inorganic salt other than an external emulsifier; and (d) sufficient water to act as the continuous phase of said dispersion.

Claim 9

The dispersion of claim 5 wherein (a) the organic or inorganic salt is the salt of a mineral acid and an alkaline earth metal, and (b) the water content is between about 95 and 35 wt.%.

Claim 10

A stable aqueous dispersion which yields films having superior water resistance and/or blocking resistance comprising (a) a polyurethane having a non-ionic hydrophilic group content of greater than 1 wt.% based on solids; (b) sufficient anionic or non-ionic hydrophilic groups chemically incorporated into said polyurethane or sufficient external emulsifier to render said dispersion stable; (c) between 0.01 to 0.4 wt.%, based on solids, of a water soluble organic or inorganic salt other than an external emulsifier; and (d) about 35 to 95 wt.% water.

Claim 11

A stable aqueous dispersion which yields films having superior water resistance and/or blocking resistance comprising (a) a polyurethane having a non-ionic hydrophilic group content of greater than 1 wt.% based on solids; (b) sufficient anionic or non-ionic hydrophilic groups chemically incorporated into said polyurethane or sufficient external emulsifier to render said dispersion stable; (c) between 0.01 to 0.4 wt.%, based on solids, of a water soluble organic or inorganic salt other than an external emulsifier; and (d) about 35 to 95 wt.% water.

Claim 12

The dispersion of claim 7 wherein (a) said electrolyte is the salt of a mineral acid and an alkaline earth metal, and (b) the requirement of component (b) is met by providing sufficient anionic or non-ionic hydrophilic groups chemically incorporated into said polyurethane.