Claims
- 1. An aqueous cathodic electrodeposition lacquer coating composition which comprises the following components (A) one or more binders or synthetic amino-epoxy resins containing hydroxyl and amino-groups which can be made soluble or dispersible in water by protonization with acids, and which resins are substantially free of carboxyl groups, (B synthetic (meth)acrylic resin crosslinking reagents which react with binder (A) on baking, and (C) soluble and/or insoluble transesterification and/or esterification catalysts for thermal crosslinking reaction at temperatures about 100.degree. C. wherein:
- (a) comprises from 95to 5% by eight, based on resin solids content of the aggregate of components (A) and (B), of one or more polymeric amino-epoxy resins obtained by reaction of components which contain at least two epoxy groups with components which contain an amino group, or mixtures thereof, wherein the resin or resins,
- (a) have a number average molecular weight (M.sub.n) of from 700 to 10,000, and
- (b) contain from 0 to 21.7.times.10.sup.23 lateral or terminal double bonds per 1000 g, corresponding to a hydrogenation iodine number of from 0 to 90,
- (c) contain primary hydroxyl groups corresponding to a hydroxyl number of from 15 to 150; and
- (d) contain tertiary amino groups corresponding to an amine number of from 30 to 150, and wherein:
- (B) comprises from 5 to 95% by weight, based on the aggregate of components (A) and (B), of a crosslinking agent comprising compounds selected from the group consisting of acrylic or methacrylic acid esters of polyhydroxyl alcohols (meth)acrylamide compounds reacted with hydroxylated compounds, glycidyl (meth)acrylate reaction products with compounds containing carboxyl or primary or secondary amino groups, transesterification products of esters and polyesters of (meth)acrylic acids and polymeric reaction products of isocyanate group containing compounds or prepolymers with hydroxyalkyl (meth)acrylate esters, or mixtures thereof having a number average molecular weight (M.sub.n) of from 170 to 10,000 and containing on average at least 2 terminal or lateral ethylenic double bonds in the acrylic or (meth)acrylic groups of said polymers per molecule and containing less than 1 terminal ester group per molecule capable of transesterification on baking.
- 2. A coating composition as claimed in claim 1, characterized in that component (A) is present in a quantity of from 95 to 40% by weight and component (B) is present in a quantity of from 5 to 60% by weight, said percentages being based on the aggregate resin solid content of components (A) and (B).
- 3. A coating composition as claimed in claim 1, wherein component (B) contains on average at least 2 groups corresponding to the following formula: ##STR3## in which R represents hydrogen or the methyl group, per molecule.
- 4. A coating composition as claimed in claim 1 wherein component (B) contains on average less than 0.5 terminal ester groups capable of transesterification on baking per molecule.
- 5. A coating composition as claimed in claim 4, wherein component (B) contains substantially no terminal ester groups capable of transesterification on baking.
- 6. A coating composition as claimed in claim 1 wherein component (A) has a number average molecular weight (Mn) of from 1500 to 5000.
- 7. A coating composition as claimed in claim 1 wherein component (A) contains primary hydroxyl groups corresponding to a hydroxyl number of from 20 to 180.
- 8. A coating composition as claimed in claim 1 wherein component (A) comprises modified bisphenol-A- and/or bisphenol-F- and/or novolak-epoxy resins.
- 9. A coating composition as claimed in claim 1 wherein component (A) contains primary and/or secondary amino groups corresponding to an amine number of less than 10.
- 10. A coating composition as claimed in claim 1 wherein component (B) has a number average molecular weight (Mn) of from 250 to 6000.
- 11. A method of coating a surface which comprises cathodically depositing a film of a lacquer as described in claim 1 onto electrically conductive surfaces and baking said film at a temperature not exceeding 210.degree. C.
- 12. The method of claim 11, wherein the lacquer film is baked at a temperature not exceeding 190.degree. C.
- 13. The method of claim 11, wherein the lacquer film is baked at a temperature not exceeding 170.degree. C.
Priority Claims (1)
Number |
Date |
Country |
Kind |
3615810 |
May 1986 |
DEX |
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Parent Case Info
This application is a continuation of application Ser. No. 07/378,421, filed Jul. 10, 1989, now abandoned, which is a continuation of application Ser. No. 07/047,700 filed Jul. 10, 1987 now abandoned.
US Referenced Citations (12)
Non-Patent Literature Citations (1)
Entry |
Epoxy Resins and Products--Recent Advances--by M. William Ranney. |
Continuations (2)
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Number |
Date |
Country |
Parent |
378421 |
Jul 1989 |
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Parent |
47700 |
May 1987 |
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