Claims
- 1. A process for the production of a multicoat finish, including the steps of:
- (1) applying an aqueous, pigmented basecoat to a substrate surface as basecoat,
- (2) forming a polymer film from the coating applied in stage (1),
- (3) applying a transparent topcoat to the basecoat, and subsequently
- (4) baking the basecoat together with the topcoat; wherein the basecoat contains a water-thinnable, uncrosslinked polyacrylate resin prepared by a solution polymerization process consisting essentially of the steps of:
- (I) polymerizing
- (a1) 40 to 90% by weight of a (meth)acrylic acid ester essentially free from carboxyl groups selected from the group consisting of alkyl acrylates, alkyl methacrylates, cycloaliphatic acrylic acid esters, cycloaliphatic methacrylic acid esters, and mixtures thereof,
- (a2) 0 to 45% by weight of an ethylenically unsaturated monomer which contains at least one hydroxyl group per molecule and is essentially free from carboxyl groups, or a mixture of such monomers, and
- (a3) 0 to 40% by weight of an ethylenically unsaturated monomer essentially free from carboxyl groups, which is different from (a 1) and (a2),
- in an organic solvent or mixture of solvents in the presence of at least one polymerization initiator, and
- (II) adding, after at least 80% by weight of the monomers in stage (I) have reacted,
- (b1) 2.5 to 15% by weight of an ethylenically unsaturated monomer containing at least one carboxyl group per molecule, or a mixture of such monomers, and
- (b2) 0 to 60% by weight of an ethylenically unsaturated monomer essentially free from carboxyl groups, or a mixture of such monomers, and continuing the polymerization to obtain the polyacrylate resin, and
- (III) neutralizing, at least partially, the polyacrylate resin and dispersing it in water;
- wherein the sum of (a1), (a2), (a3), (b1), and (b2) is 100% and further wherein the uncrosslinked polyacrylate resin has a hydroxyl value of 0 to 200, an acid value of 20 to 100, a glass transition temperature (T.sub.G) of -40.degree. to +60.degree. C., and a molecular weight of between 2,500 and 20,000.
- 2. The process as claimed in claim 1 wherein the basecoat further contains a metallic pigment or a mixture of metallic pigments.
- 3. The process as claimed in claim 1, wherein polymerization is carried out in stages (I) and (II) at a temperature of 80.degree. to 160.degree. C. in the presence of at least one free radical-forming initiator, the duration of stage (I) is 2 to 8 hours, and the stage (II) addition is carried out over a period of 10 to 90 minutes.
- 4. The process as claimed in claim 1, wherein the stage (II) addition is begun after at least 90% by weight of the monomers added in stage (I) have reacted.
- 5. The process as claimed in claim 1, wherein the basecoat further comprises a resin selected from the group consisting of a water-thinnable polyurethane resin, a water-thinnable polyester resin, a water-thinnable amino resin, and mixtures thereof.
- 6. The process as claimed in claim 1, wherein the basecoat comprises at least one non-metallic pigment and a mixture consisting of
- (A) 10 to 95% by weight of the water-thinnable polyacrylate resin,
- (B) 5 to 50% by weight of an amino resin,
- (C) 0 to 85% by weight of a water-thinnable polyester resin, and
- (D) 0 to 85% by weight of a water-thinnable polyurethane resin,
- the sum of components (A) to (D) being 100%.
- 7. The process as claimed in claim 1, wherein the basecoat comprises a metallic pigment and a mixture consisting of
- (A) 0.1 to 60% by weight of the water-thinnable polyacrylate resin,
- (B) 0 to 50% by weight of an amino resin,
- (C) 0 to 50% by weight of a water-thinnable polyester resin, and
- (D) 10 to 99.9% by weight of a water-thinnable polyurethane resin,
- the sum of components (A) to (D) being 100%.
- 8. The process as claimed in claim 5, wherein the basecoat comprises a water-thinnable polyester resin obtained by reacting
- (.alpha.) a polyol or a mixture of polyols, consisting of 30 to 100 mol % of aliphatic diols containing at least one .alpha. carbon that is secondary, tertiary, or in a ring system, and
- (.beta.) a member selected from the group consisting of polycarboxylic acids, polycarboxylic anhydrides, and mixtures thereof, wherein component (.beta.) consists of 50 to 100 mol % of aromatic or cycloaliphatic polycarboxylic acids or mixtures thereof, and 15 to 40 mol % of tricarboxylic or tetracarboxylic acids or mixtures thereof, with the caveat that at least two carboxyl groups of the tricarboxylic and tetracarboxylic acids react on statistical average,
- in a molar ratio of components (.alpha.) and (.beta.) of 1.15-2.00:1;
- and further wherein the polyester resin is at least partially neutralized and has a number average molecular weight of 600 to 5000, an acid value of 20 to 70, and a hydroxyl value of 30 to 200.
- 9. The process as claimed in claim 8, wherein the component (.beta.) consists of 50 to 80 mol % of aromatic or cycloaliphatic polycarboxylic acids or mixtures thereof, and 20 to 50 mol % of one or more polymeric fatty acids, wherein the polymeric fatty acids are not cycloaliphatic polycarboxylic acids.
- 10. An aqueous, pigmented paint containing a water-thinnable, uncrosslinked polyacrylate resin prepared by a solution polymerization process consisting essentially of
- (I) polymerizing
- (a1) 40 to 90% by weight of a (meth)acrylic acid ester essentially free from carboxyl groups selected from the group consisting of alkyl acrylates, alkyl methacrylates, cycloaliphatic acrylic acid esters, cycloaliphatic methacrylic acid esters, and mixtures thereof,
- (a2) 0 to 45% by weight of an ethylenically unsaturated monomer which contains at least one hydroxyl group per molecule and is essentially free from carboxyl groups, or a mixture of such monomers, and
- (a3) 0 to 40% by weight of an ethylenically unsaturated monomer essentially free from carboxyl groups, which is different from (a1) and (a2), or a mixture of such monomers,
- in an organic solvent or mixture of solvents in the presence of at least one polymerization initiator, and
- (II) adding, after at least 80% by weight of the monomers in stage (I) have reacted,
- (b 1) 2.5 to 15% by weight of an ethylenically unsaturated monomer containing at least one carboxyl group per molecule, or a mixture of such monomers, and
- (b2) 0 to 60% by weight of an ethylenically unsaturated monomer essentially free from carboxyl groups, or a mixture of such monomers, and continuing the polymerization to obtain the polyacrylate resin, and
- (III) neutralizing, at least partially, the polyacrylate resin and dispersing it in water;
- wherein the sum of (a1), (a2), (a3), (b1) and (b2) is 100% and further wherein the polyacrylate resin has a hydroxyl value of 0 to 200, an acid value of 20 to 100, a glass transition temperature (T.sub.G) of -40.degree. to +60.degree. C., and a molecular weight of between 2,500 and 20,000.
- 11. The paint as claimed in claim 10 wherein the paint further contains a metallic pigment or a mixture of metallic pigments.
- 12. The paint as claimed in claim 10, wherein polymerization is carried out in stages (I) and (II) at a temperature of 80.degree. to 160.degree. C. in the presence of at least one free radical-forming initiator, the duration of stage (I) is 2 to 8 hours, and the stage (II) addition is carried out over a period of 10 to 90 minutes.
- 13. The paint as claimed in claim 10, wherein the stage (II) addition is begun after at least 90% by weight of the monomers added in stage (I) have reacted.
- 14. The paint as claimed in claim 10, wherein the paint further comprises a resin selected from the group consisting of a water-thinnable polyurethane resin, a water-thinnable polyester resin, a water-thinnable amino resin, and mixtures thereof.
- 15. The paint as claimed in claim 10, wherein the paint comprises at least one non-metallic pigment and a mixture consisting of
- (A) 10 to 95% by weight of the water-thinnable polyacrylate resin,
- (B) 5 to 50% by weight of an amino resin,
- (C) 0 to 85% by weight of a water-thinnable polyester resin, and
- (D) 0 to 85% by weight of a water-thinnable polyurethane resin,
- the sum of components (A) to (D) being 100%.
- 16. The paint as claimed in claim 10, wherein the paint comprises a metallic pigment and a mixture consisting of
- (A) 0.1 to 60% by weight of the water-thinnable polyacrylate resin,
- (B) 0 to 50% by weight of an amino resin,
- (C) 0 to 50% by weight of a water-thinnable polyester resin, and
- (D) 10 to 99.9% by weight of a water-thinnable polyurethane resin,
- the sum of components (A) to (D) being 100%.
- 17. The paint as claimed in claim 14, wherein the paint comprises a water-thinnable polyester resin obtained by reacting
- (.alpha.) a polyol or a mixture of polyols, consisting of 30 to 100 mol % of aliphatic diols containing at least one .alpha. carbon that is secondary, tertiary, or in a ring system, and
- (.beta.) a member selected from the group consisting of polycarboxylic acids, polycarboxylic anhydrides, and mixtures thereof, wherein component (.beta.) consists of 50 to 100 mol % of aromatic or cycloaliphatic polycarboxylic acids or mixtures thereof, and 15 to 40 mol % of tricarboxylic or tetracarboxylic acids or mixtures thereof, with the caveat that at least two carboxyl groups of the tricarboxylic and tetracarboxylic acids react on statistical average,
- in a molar ratio of components (.alpha.) and (.beta.) of 1.15-2.00:1;
- and further wherein the polyester resin is at least partially neutralized and has a number average molecular weight of 600 to 5000, an acid value of 20 to 70, and a hydroxyl value of 30 to 200.
- 18. The paint as claimed in claim 12, wherein the component (.beta.) consists of 50 to 80 mol % of aromatic or cycloaliphatic polycarboxylic acids or mixtures thereof, and 20 to 50 mol % of one or more polymeric fatty acids, where the polymeric fatty acids are not cycloaliphatic polycarboxylic acids.
- 19. The process as claimed in claim 1, wherein the stage (II) addition is carried out over a period of 10 to 90 minutes.
- 20. The paint as claimed in claim 10, wherein the stage (II) addition is carried out over a period of 10 to 90 minutes.
- 21. A process for the production of a multicoat finish, including the steps of
- (1) applying an aqueous, pigmented basecoat to a substrate surface as basecoat,
- (2) forming a polymer film from the coating applied in stage (1),
- (3) applying a transparent topcoat to the basecoat, and subsequently
- (4) baking the basecoat together with the topcoat;
- wherein the basecoat contains a water-thinnable, uncrosslinked polyacrylate resin prepared by a solution polymerization process consisting essentially of the steps of:
- (I) polymerizing
- (a1) 40 to 80% by weight of a (meth)acrylic acid ester essentially free from carboxyl groups selected from the group consisting of alkyl acrylates, alkyl methacrylates, cycloaliphatic acrylic acid esters, cycloaliphatic methacrylic acid esters, and mixtures thereof,
- (a2) 4 to 34% by weight of an ethylenically unsaturated monomer which contains at least one hydroxyl group per molecule and is essentially free from carboxyl groups, or a mixture of such monomers, and
- (a3) 10 to 30% by weight of an ethylenically unsaturated monomer essentially free from carboxyl groups, which is different from (a1) and (a2),
- in an organic solvent or mixture of solvents in the presence of at least one polymerization initiator, and
- (II) adding, after at least 80% by weight of the monomers in stage (I) have reacted,
- (b1) 2.5 to 15% by weight of an ethylenically unsaturated monomer containing at least one carboxyl group per molecule, or a mixture of such monomers, and
- (b2) 0 to 60% by weight of an ethylenically unsaturated monomer essentially free from carboxyl groups, or a mixture of such monomers, and continuing the polymerization to obtain the polyacrylate resin, and
- (III) neutralizing, at least partially, the polyacrylate resin and dispersing it in water;
- wherein the sum of (a1), (a2), (a3), (b1) and (b2) is 100% and further wherein the uncrosslinked polyacrylate resin has a hydroxyl value of 0 to 200, an acid value of 20 to 100, a glass transition temperature (T.sub.G) of -40.degree. to +60.degree. C., and a molecular weight of between 2,500 and 20,000.
- 22. An aqueous, pigmented paint containing a water-thinnable polyacrylate resin prepared by a solution polymerization process consisting essentially of the steps of:
- (I) polymerizing
- (a1) 40 to 80% by weight of a (meth)acrylic acid ester essentially free from carboxyl groups selected from the group consisting of alkyl acrylates, alkyl methacrylates, cycloaliphatic acrylic acid esters, cycloaliphatic methacrylic acid esters, and mixtures thereof,
- (a2) 4 to 34% by weight of an ethylenically unsaturated monomer which contains at least one hydroxyl group per molecule and is essentially free from carboxyl groups, or a mixture of such monomers, and
- (a3) 10 to 30% by weight of an ethylenically unsaturated monomer essentially free from carboxyl groups, which is different from (a1) and (a2), or a mixture of such monomers,
- in an organic solvent or mixture of solvents in the presence of at least one polymerization initiator, and
- (II) adding, after at least 80% by weight of the monomers in stage (I) have reacted,
- (b1) 2.5 to 15% by weight of an ethylenically unsaturated monomer containing at least one carboxyl group per molecule, or a mixture of such monomers, and
- (b2) 0 to 60% by weight of an ethylenically unsaturated monomer essentially free from carboxyl groups, or a mixture of such monomers, and continuing the polymerization to obtain the polyacrylate resin, and
- (III) neutralizing, at least partially, the polyacrylate resin and dispersing it in water;
- wherein the sum of (a1), (a2), (a3), (b1), and (b2) is 100% and further wherein the uncrosslinked polyacrylate resin has a hydroxyl value of 0 to 200, an acid value of 20 to 100, a glass transition temperature (T.sub.G) of -40.degree. to +60.degree. C., and a molecular weight of between 2,500 and 20,000.
- 23. A process for the production of a multicoat finish according to claim 1, wherein the uncrosslinked polyacrylate resin has a hydroxyl value of 20 to 120, an acid value of 25 to 50, and a glass transition temperature (T.sub.G) of -20.degree. to +40.degree. C.
- 24. The process according to claim 16, wherein the mixture consists of:
- (A) 25 to 70% by weight of the water-thinnable polyacrylate resin,
- (B) 10 to 40% by weight of the amino resin,
- (C) 20 to 60% by weight of the water-thinnable polyester resin, and
- (D) 0 to 40% by weight of the water-thinnable polyurethane resin.
- 25. The process according to claim 7, wherein the mixture consists of:
- (A) 1 to 30% by weight of the water-thinnable polyacrylate resin,
- (B) 5 to 30% by weight of the amino resin,
- (C) 15 to 40% by weight of the water-thinnable polyester resin, and
- (D) 20 to 60% by weight of the water-thinnable polyurethane resin.
- 26. The process as claimed in claim 8, wherein the molar ratio of components (.alpha.) and (.beta.) is 1.2-1.5:1, and further wherein the polyester resin has a number average molecular weight of 800 to 2500, an acid value of 25 to 55, and a hydroxyl value of 45 to 100.
- 27. The paint according to claim 15, wherein the mixture consists of:
- (A) 25 to 70% by weight of the water-thinnable polyacrylate resin,
- (B) 10 to 40% by weight of the amino resin,
- (C) 20 to 60% by weight of the water-thinnable polyester resin, and
- (D) 0 to 40% by weight of the water-thinnable polyurethane resin.
- 28. The paint according to claim 16, wherein the mixture consists of:
- (A) 1 to 30% by weight of the water-thinnable polyacrylate resin,
- (B) 5 to 30% by weight of the amino resin,
- (C) 15 to 40% by weight of the water-thinnable polyester resin, and
- (D) 20 to 60% by weight of the water-thinnable polyurethane resin.
- 29. The paint as claimed in claim 16, wherein the molar ratio of components (.alpha.) and (.beta.) is 1.2-1.5:1, and further wherein the polyester resin has a number average molecular weight of 800 to 2500, an acid value of 25 to 55, and a hydroxyl value of 45 to 100.
Priority Claims (1)
Number |
Date |
Country |
Kind |
40 09 858.3 |
Mar 1990 |
DEX |
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Parent Case Info
This is a continuation of application Ser. No. 07/927,522 filed on Sep. 17, 1992, now abandoned.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4403003 |
Backhouse |
Sep 1983 |
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Continuations (1)
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Number |
Date |
Country |
Parent |
927522 |
Sep 1992 |
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