Process for coating substrate and an aqueous coating composition based on a cationic binder
AssigneeAkzo N.V.
InventorsChantal H. Guioth, Etienne G. Maze, Jean J. Trescol
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Abstract
A process is provided for coating an electrically conductive substrate with an aqueous coating composition containing a cationic binder wherein the binder is obtained by polymerization of 100 parts by weight of a specified monomer mixture in the presence of 0.5 to 25 parts by weight of a polyurethane having 2-5 acryloyl groups or methacryloyl groups, a molecular weight of 400-7000 and a molecular weight per (meth)acryloyl group of at least 200. The invention also pertains to the aqueous composition as such.
Claims21
A process for coating a substrate, comprising applying to said substrate an aqueous coating composition based on a cationic binder obtained by polymerization of a monomer mixture in the presence of 0.5 to 25 parts by weight of a polyethylenically unsaturated compound per 100 parts by weight of the monomer mixture,
- said monomer mixture consisting of (a) 1-30% by weight of a hydroxy(cyclo)alkyl (meth)acrylate of which the (cyclo)alkyl group contains 2-8 carbon atoms, (b) 4-45% by weight of an amino (meth)acrylate of the formula ##STR3## where at least one of the groups R.sub.1 is an organic group containing 1-12 carbon atoms and the other group R.sub.1 is an organic group containing 1-12 carbon atoms or a hydrogen atom, or the two groups R.sub.1, together with the nitrogen atom attached thereto, form a heterocyclic group, R.sub.2 is a hydrocarbon group containing 2-12 carbon atoms and R.sub.3 is a hydrogen atom or a methyl group, (c) 0-80% by weight of a monovinyl aromatic hydrocabon containing 8-14 carbon atoms, and (d) 0-50% by weight of a different monoethylenically unsaturated monomer containing 2-20 carbon atoms;
- said polyethylenically unsaturated compound being a polyurethane having 2-5 acryloyl groups or methacryloyl groups, a molecular weight of 400-7000 and a molecular weight per (meth)acryloyl group of at least 200;
- amino groups in said binder being at least partially neutralized with an acid.
An aqueous coating composition based on a cationic binder obtained by polymerization of a monomer mixture in the presence of 0.25-25 parts by weight of a polyethylenically unsaturated compound per 100 parts by weight of the monomer mixture,
- said monomer mixture consisting of (a) 1-30% by weight of a hydroxy(cyclo)alkyl (meth)acrylate of which the (cyclo)alkyl group has 2-8 carbon atoms, (b) 4-45% by weight of an amino (meth)acrylate of the formula:
- ##STR4## wherein at least one of the groups R.sub.1 is an organic group having 1-12 carbon atoms and the other group R.sub.1 is an organic group having 1-12 carbon atoms or a hydrogen atom, or the two groups R.sub.1, together with the nitrogen atom attached thereto, form a heterocyclic group, R.sub.2 is a hydrocarbon group containing 2-12 carbon atoms and R.sub.3 is a hydrogen atom or a methyl group, (c) 0-80% by weight of a monovinyl aromatic hydrocarbon containing 8-14 carbon atoms, and (d) 0-50% by weight of a different monoethylenically unsaturated monomer containing 2-20 carbon atoms;
- said polyethylenically unsaturated compound being a polyurethane having 2-5 acryloyl groups or methacryloyl groups, a molecular weight of 400-7000 and a molecular weight per (meth)acryloyl group of at least 200;
- amino groups present in said binder being at leaast partially neutralized with an acid.
Dependencies are inferred from the claim text.