US 4,975,474 AGrant
Multi-Component Coating Composition Comprising an Anhydride Containing Polymer, a Glycidyl Component and a Self-Stabilized Dispersion Resin
Issue Date:1990-12-04
•3 Claims
Abstract
A coating composition useful for a finish for automobiles and trucks in which the film forming binder contains reactive binder components of about the composition contains about 0.1-5% by weight; based on the weight of the binder, of a catalyst. (a) 25-94% by weight, based on the weight of the binder, of an acrylic polymer having at least two reactive anhydride groups composed of polymerized monomers of an ethylenically unsaturated anhydride and polymerized monomers from the group consisting of alkyl methacrylate, alkyl acrylate and any mixtures thereof, wherein the alkyl groups have 1-8 carbon atoms and the polymer has a weight average molecular weight of about 2,000-50,000; (b) 5-50% by weight, based on the weight of the binder, of a glycidyl component having at least two reactive glycidyl groups; (c) 1-40% by weight, based on the weight of the binder, of a self-stabilized dispersed resin; and
Metadata
Assignee
- E. I. du Pont de Nemours and Company
Inventors
- Robert J. Barsotti
- Patrick H. Corcoran
Application Information
Application Number:US 4198476
Filing Date:1989-10-11
Priority Date:1988-06-27
Art Unit:153
Classifications
IPC:
C08K 501C08K 510C08L 6302
Field of Search:
523525428400;437;43974;94;108;113;116;117;118;119;207;208;221413
Patent Drawings
This patent does not have any drawings.
Description
EXAMPLE 1
Anhydride Acrylic Polymer
An anhydride acrylic polymer was prepared by charging the following constituents into a reactor with a thermometer, stirrer, dropping funnel, nitrogen induction tube and condensor:
Portion 1 was charged into the reactor, covered with a nitrogen blanket and heated to its reflux temperature (approximately 135.degree. C.). Portion 2 is added dropwise over a 180 minute period. Portion 3 is added simultaneously with portions 2 and 4 over a 180 minute period as 5 minute increment shots of solid itaconic acid followed with washings of xylene. Portion 4 was premixed and added dropwise simultaneously with portions 2 and 3 over a 200 minute period. The resulting composition is then held at reflux until 22 pounds of water per 100 gallon batch size are removed.
The resulting polymer composition had a weight solids content of 64-66% and the polymer had a Gardner-Holdt Viscosity of X-Z2. The polymer had a weight average molecule weight of 3500.
A nonaqueous acrylic resin dispersion was prepared by charging the following constituents into a reaction vessel equipped with a stirrer, a heating source and a reflux condenser;
Portion 1 is charged into the reaction vessel and heated to its reflux temperature Portion 2 is added to the reaction vessel mixed and held at reflux temperature for two minutes. Then portions 3 and 4 are added simultaneously with portions 5 over a 210 minute period to the reaction vessel while maintaining the resulting reaction mixture at its reflux temperature. Then the mixture is held at its reflux temperature for an additional 45 minutes. Portion 6 is added over a 90 minute period while maintaining the reaction mixture at its reflux temperature and then held at this temperature for an additional 90 minutes. Portion 7 is added and excess solvent is stripped off to give a 60% solids acrylic resin dispersion.
A coating composition was prepared by thoroughly blending together the following constituents:
The resulting coating composition was reduced to a spray viscosity of 35 seconds measured with a No. 2 Zahn Cup by adding butyl acetate.
The coating composition was sprayed onto a primed metal panel coated with a waterborne basecoat and cured at 180.degree.-200.degree. F. and provided a clear coat with excellent color, durability, humidity resistance and other film properties. The coating was also sprayed over solvent borne melamine cured basecoat at 240.degree.-295.degree. F. The resulting coating exhibited excellent color, durability, humidity resistance and other film properties.
EXAMPLE 2
An epoxy acrylic polymer was prepared by charging the following constituents into a reactor with a thermometer, stirrer, dropping funnel, nitrogen induction tube and condenser:
Portion 1 was charged into the reactor, covered with a nitrogen blanket and heated to its reflux temperature. Portions 2 and 3 were premixed and added simultaneously and dropwise to the reactor over a 300 minute period while holding the reactor at reflux temperature. Portion 4 was then premixed and added to the reactor over a 30 minute period. The reactor was held at reflux for a 30 minute period.
The resulting polymer composition had a weight solids content of 60% and the polymer had a Gardner-Holdt viscosity of C. The polymer had a weight average molecular weight of 4500.
A coating composition was prepared by thoroughly blending together the following constituents:
The resulting coating composition was reduced to a spray viscosity of 31 seconds, measured with a No. 2 Zahn Cup by adding butyl acetate.
The coating composition was sprayed onto a primed metal panel coated with pigmented acrylic lacquer. The composition cured at ambient temperature and provided a film which was hard, glossy and durable.
Claims
We claim:
1. A substrate coated with a layer of a waterborne basecoat and a clearcoat wherein the basecoat and clearcoat are cured at ambient or elevated temperatures and the clearcoat has a composition comprising 20-80% by weight of reactive binder components and 80-20% by weight of an organic liquid carrier; wherein the binder comprises: (a) 25-94% by weight, based on the weight of the binder, of an anhydride acrylic polymer having at least two reactive anhydride groups that consists of polymerized monomers of an ethylenically unsaturated anhydride or an ethylenically unsaturated dicarboxylic acid and polymerized monomers selected from the group consisting of alkyl methacrylate, alkyl acrylate and any mixtures thereof, wherein the alkyl groups have 1-8 carbon atoms and the polymer has a weight average molecular weight of about 2,000-50,000; (b) 5-50% by weight, based on the weight of the binder, of a glycidyl component having at least two reactive glycidyl groups; (c) 1 to 40 % by weight, based on the weight of the binder, of a self stabilized dispersed resin formed by polymerizing in solution the following constituents; (1) an acrylic solution polymer, (2) monomers of alkyl methacrylate or acrylate and hydroxy ethyl acrylate or methacrylate, wherein either the acrylic solution polymer contains post reacted glycidyl methacrylate or acrylate or the monomers additionally contain glycidyl methacrylate or acrylate, and the composition contains about 0.1-5% by weight, based on the weight of the binder, of a catalyst.
2. A substrate coated with a layer of solvent borne melamine crosslinked basecoat and a clearcoat wherein the basecoat and clearcoat are cured at elevated temperatures and the clearcoat has a composition comprising 20-80% by weight of reactive binder components and 80-20% by weight of an organic liquid carrier; wherein the binder comprises: (a) 25-94% by weight, based on the weight of the binder, of an anhydride acrylic polymer having at least two reactive anhydride groups that consists of polymerized monomers of an ethylenically unsaturated anhydride or an ethylenically unsaturated dicarboxylic acid and polymerized monomers selected from the group consisting of alkyl methacrylate, alkyl acrylate and any mixtures thereof, wherein the alkyl groups have 1-8 carbon atoms and the polymer has a weight average molecular weight of about 2,000-50,000; (b) 5-50% by weight, based on the weight of the binder, of a glycidyl component having at least two reactive glycidyl groups; (c) 1 to 40% by weight, based on the weight of the binder, of a self stabilized dispersed resin formed by polymerizing in solution the following constituents; (1) an acrylic solution polymer, (2) monomers of alkyl methacrylate or acrylate and hydroxy ethyl acrylate or methacrylate, wherein either the acrylic solution polymer contains post reacted glycidyl methacrylate or acrylate or the monomers additionally contain glycidyl methacrylate or acrylate, and the composition contains about 0.1-5% by weight, based on the weight of the binder, of a catalyst.
3. A substrate coated with a layer of solvent borne lacquer basecoat and a clearcoat wherein the basecoat and clearcoat are cured at ambient temperatures and the clearcoat has a composition comprising 20-80% by weight of reactive binder components and 80-20% by weight of an organic liquid carrier; wherein the binder comprises: (a) 25-94% by weight, based on the weight of the binder, of an anhydride acrylic polymer having at least two reactive anhydride groups that consists of polymerized monomers of an ethylenically unsaturated anhydride or an ethylenically unsaturated dicarboxylic acid and polymerized monomers selected from the group consisting of alkyl methacrylate, alkyl acrylate and any mixtures thereof, wherein the alkyl groups have 1-8 carbon atoms and the polymer has a weight average molecular weight of about 2,000-50,000; (b) 5-50% by weight, based on the weight of the binder, of a glycidyl component having at least two reactive glycidyl groups; (c) 1 to 40% by weight, based on the weight of the binder, of a self stabilized dispersed resin formed by polymerizing in solution the following constituents; (1) an acrylic solution polymer, (2) monomers of alkyl methacrylate or acrylate and hydroxy ethyl acrylate or methacrylate, wherein either the acrylic solution polymer contains post reacted glycidyl methacrylate or acrylate or the monomers additionally contain glycidyl methacrylate or acrylate, and the composition contains about 0.1-5% by weight, based on the weight of the binder, of a catalyst.