Scale control

Claim 2

The process of claim 1 wherein the surface is non-metallic.

Claim 3

The process of claim 1 where the blocked polyisocyanate has an aromatic nucleus attached to the isocyanate radical.

Claim 4

The process of claim 4 wherein the blocked polyisocyanate is toluene diisocyanate reacted with phenol.

Claim 5

The process of claim 1 wherein the polyether polyol is an alkylene oxide adduct of a trihydric alcohol.

Claim 6

The process of claim 1 wherein the monohydric polyether is represented by the formula R-O---CH2-CHR''-O-----nH wherein R alkyl, aryl, or other radical which is non-reactive with isocyanate functional groups, R'' alkyl and n three to 50.

Claim 7

The process of claim 1 wherein the reaction between the isocyanate radicals and active hydrogens on the polyether polyol and monohydric polyether is catalyzed by the addition of a catalyst.

Claim 8

A process for imparting scale resistance to a surface comprising applying a liquid coating of a resin prepared by the reaction of a monohydric polyether with two equivalents of a conventional diisocyanate and in turn reacting said resin with an excess of a polyether polyol derived from polyhydric alcohols having a hydroxyl functionality of about three or greater which have been polyoxyalkylated so that an average of about two to 50 oxyalkylene groups, -CH2-CHR-O-, where R alkyl, have been added to each hydroxyl group and in turn combining this reacted mixture with a blocked diisocyanate and an inert solvent system in proportions capable of forming a solid coating upon reacting, heating the coating to a temperature sufficient to drive the blocking agent from the isocyanate and, maintaining sufficient heat on the coating to cause the reaction between the isocyanate and the polyol to proceed to completion.

Claim 9

The process of claim 9 wherein the surface is metallic.

Claim 10

The process of claim 9 wherein the surface is non-metallic.

Claim 11

The process of claim 9 where the conventional isocyanate is toluene diisocyanaTe.

Claim 12

The process of claim 9 where the blocked diisocyanate has an aromatic nucleus attached to the isocyanate radical.

Claim 13

The process of claim 13 wherein the blocked polyisocyanate is toluene diisocyanate reacted with phenol.

Claim 14

The process of claim 9 wherein the polyether polyol is an alkylene oxide adduct of a trihydric alcohol.

Claim 15

The process of claim 9 wherein the monohydric polyether is represented by the formula R-O----CH2-CHR''-O----nH wherein R alkyl, aryl, or other radical which is non-reactive with isocyanate functional groups, R'' alkyl and n three to 50.

Claim 16

The process of claim 9 wherein the reaction between the isocyanate radicals and active hydrogens on the polyether polyol and monohydric polyether is catalyzed by the addition of a catalyst.

Claim 17

A process for imparting scale-resistance to substrate surfaces normally susceptible to mineral scale formation when in contact with mineralized water, comprising the steps of: successively applying to said scale-susceptible substrate surfaces a base coat of a curable resin priming material, and partially curing said priming material, applying at least one outer coating of polyurethane resin comprising a blocked isocyanate, a polyether polyol derived from polyhydric alcohols having a hydroxyl functionality of about three or greater which have been polyoxyalkylated so that an average of about two to 50 oxyalkylene groups, -CH2-CHR-O-, where R alkyl, have been added to each hydroxyl group, and a monohydric polyether in proportions capable of forming a solid coating having pendant polyoxyalkylene chains upon reacting together, and subjecting each said coat to an intermediate heat cure, followed by a final heat curing of the coatings such that said coatings possess good adhesion to said substrate, stability of in-service environmental conditions, but without significant loss of the integrity of the pendant polyoxyalkylene chains in said polyurethane resin.