Method for treating polyester resin system with organic acid to suppress gel-time drift
AssigneeKoppers Company, Inc.
InventorHilda Howell
Life of this patent
Estimating the term…
Abstract
A method is disclosed for treating polyester resin systems to suppress gel-time drift for the useable storage life of the resin system. The method comprises contacting a solution containing a polyester binder with an organic acid either between formulation stages or after formulation of the resin system. Typically useful organic acids include aromatic dicarboxylic acids such as phthalic acid and unsaturated aliphatic dicarboxylic acids such as fumaric acid. Comparative data for gel times of polyester resin system samples treated according to the disclosed method show suppression of gel-time drift to as low as 6 percent of the gel-time drift of counterpart untreated resin system samples.
Claims33
A method for treating a curable polyester resin system to reduce gel-time drift of the resin system, which system comprises unsaturated polymerizable material which includes a polyester binder and, optionally, one or more soluble or insoluble additive components comprising an inhibitor, a promoter, an inert filler, a pigment, a dye, a thixotropic material, a reinforcement material, a flame retardant, a wax, and a lubricant, the method comprising the steps of:
- contacting a polyester binder of the resin system with an unsaturated acid selected from the group consisting of aliphatic mono- or polycarboxylic acid and an aromatic mono- or polycarboxylic acid in an amount and for a period of time effective to suppress gel-time drift for the useable shelf life of the resin system as compared to an untreated counterpart resin system;
- and
- removing undissolved acid from contact with the polyester resin binder.
A method for formulating and treating an unsaturated polyester resin system to provide a curable resin system wherein gel-time drift is reduced relative to an untreated counterpart resin system, which system comprises unsaturated polymerizable material including a polyester binder and one or more soluble or insoluble additive components comprising an inhibitor, a promoter, an inert filler, a pigment, a dye, a thixotropic material, a reinforcement material, a flame retardant, a wax, and a lubricant, the method comprising the steps of:
- (a) adding an unsaturated acid selected from the group consisting of aliphatic mono- or polycarboxylic acid or an aromatic mono- and polycarboxylic acid to a polyester binder dissolved in an unsaturated monomer solution to form a mixture containing the acid in an amount in a range from about 0.05 to about 5 weight percent of the polyester resin system;
- (b) mixing the acid and solution of polyester binder for a period of time in a range from about 0.1 to about 24 hours;
- and
- (c) removing undissolved acid from the mixture;
- whereby gel-time drift over the useful shelf life of the resin system is suppressed as compared to an untreated counterpart resin system.
A method for formulating and treating an unsaturated polyester resin system to provide a curable resin system wherein gel-time drift is reduced relative to an untreated counterpart resin system, comprising the steps of:
- (a) forming a curable, unsaturated polyester resin system by mixing together an unsaturated polyester binder and a copolymerizable monomer, the polyester binder being present in an amount in a range from about 10 to about 99 weight percent of the resin system and the monomer being present in an amount in a range from about one to about 90 weight percent of the resin system;
- (b) adding to the resin system an inhibitor in an amount in a range from about 0.001 to about 0.1 weight percent of the resin system and a promoter in an amount in a range from about 0.01 to about 1 weight percent of the resin system;
- (c) adding to the resin system an unsaturated aliphatic mono-or polycarboxylic acid and an aromatic mono- or polycarboxylic acid in an amount in a range from about 0.5 to about 5 weight percent of the resin system;
- (d) mixing the resin system;
- and
- (e) removing undissolved acid from the resin system;
- whereby gel-time drift is reduced for the useable shelf life of the treated polyester resin system as compared to an untreated counterpart resin system.
Dependencies are inferred from the claim text.