Paint compositions, method of paint finishing and painted objects

Abstract

To provide a paint composition which contains as essential components (A) a carboxyl group containing resin obtained by the copolymerization of a carboxyl group containing radically polymerizable monomer and other radically polymerizable monomer in which two or more carboxyl groups are included in one molecule and of which the acid value is from 100 to 300 mgKOH / g and the weight average molecular weight is from 2,000 to 30, 000, and wherein from 5 to 50 mass% of structural units based on a lactone compound are included in the resin solid fraction, (B) an epoxy group containing resin where two or more epoxy groups are included in one molecule, (C) ultraviolet absorber and (D) a light stabilizer of which the basicity (pKb) is at least 9, and in which the proportions as a mol ratio of the carboxyl groups of the (A) component and the epoxy groups of the (B) component are within the range from 75 / 25 to 25 / 75, a method of finish paining and the resulting painted objects.

Description

[technical field] [0001] This invention relates to novel paint compositions, methods of paint finishing and the resulting painted objects. More precisely, the present invention relates to paint compositions with which, in the field of motor vehicle painting, it is possible to obtain substantial masking properties with good weather resistance, acid resistance and micro-roughness of the surface to be painted , methods of paint finishing wherein these paint compositions are used, and the resulting painted objects. [Background technique] [0002] In recent years, in the field of automotive painting, there has been a need to provide a paint film having a high weather resistance, acid resistance, and an excellent appearance finish and storage stability that sufficiently withstands cyclic use. A method involving the inclusion of UV absorbers and light stabilizers in the paint film is commonly used to improve weatherability, and in terms of basic hiding properties, shrinks little ...

AI Technical Summary

Problems solved by technology

However, since amino resins are used in these paint compositions, sufficient storage stability cannot be obtained as a liquid type paint

In addition, paint compositions including acrylic polycarboxylic acids, polyepoxides, and antioxidants (for example, Cited Patent 2) and structural units containing carboxyl-containing low lactone-modified hydroxy (meth)acrylates Paint compositions of acrylic polycarboxylic acid resins with polyepoxides (for example, Cited Patent 3) are known, but in these cases, since the reactivity of the acid / epoxy group is not suppressed, it is used as a A liquid type of paint that does not give sufficient storage stability

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