Abstract Paint is removed from a painted surface by applying to the surface a solution containing an alkali metal hydroxide and a polyacrylate thickening agent having a viscosity which decreases above a predetermined transition pH. The initial pH of the composition is adjusted to just above the transition pH by including a sufficient amount of the hydroxide in the composition so that the composition is readily spreadable. As the pH of the composition falls during use its viscosity increases; thereby becoming more firmly attached to the surface; permitting the composition to remain in contact with the surface for a sufficient time to destroy the adhesion of the paint to the surface. The thickening agent is a cross-linked carboxylated copolymer of acrylic acid and methacrylate.
Inventors
👤 Philip Poels
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-11-05 07:26
CPC Classifications
C; C09; C09D; C09D9/00
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
158 words
A method of stripping paint having free carboxyl groups from a previously painted surface at a single application, which comprises applying to said painted surface a composition comprising an alkali metal hydroxide, a solvent and a polyacrylate thickening agent comprising an aqueous dispersion of from 15 to 45% by weight of a cross-linked carboxylated copolymer of acrylic acid with methacrylate having a pH lower than that of said alkali metal hydroxide in which the viscosity of said agent falls above a predetermined transition pH, said hydroxide being present in said composition in an amount sufficient to adjust the pH of the composition to just above said transition pH, whereby the viscosity of the composition increases as the pH falls in use; and allowing the applied composition to remain in contact with said painted surface for sufficient time to destroy the adhesion of the paint to the painted surface and then rinsing the paint and composition from said substrate.
Claim 2
Independent Claim
158 words
A method of stripping paint having free carboxyl groups from a previously painted surface at a single application, which comprises applying to said painted surface a composition comprising an alkali metal hydroxide, a solvent and a polyacrylate thickening agent comprising an aqueous dispersion of from 15 to 45% by weight of a cross-linked carboxylated copolymer of acrylic acid with methacrylate having a pH lower than that of said alkali metal hydroxide in which the viscosity of said agent falls above a predetermined transition pH, said hydroxide being present in said composition in an amount sufficient to adjust the pH of the composition to just above said transition pH, whereby the viscosity of the composition increases as the pH falls in use; and allowing the applied composition to remain in contact with said painted surface for sufficient time to destroy the adhesion of the paint to the painted surface and then rinsing the paint and composition from said substrate.
Claim 3
Dependent Claim
31 words
A method as claimed in claim 1 wherein the viscous polymeric thickening agent has a Brookfield viscosity at 20 rpm cps at a pH between 7 and 11 of over 3,000.