HIGH PERFORMANCE AQUEOUS COATING COMPOSITIONS

• US 20070282046A1
• Filed: 06/04/2007
• Published: 12/06/2007
• Est. Priority Date: 06/02/2006
• Status: Active Grant

• Current Assignee: Swimc, LLC (The Sherwin-Williams Company)
• Original Assignee: Valspar Sourcing, Inc. (Sherwin-Williams Company)
• Inventors: Johnson, Bruce, Wildman, Michael, Killilea, T., Weber, Carl
• Granted Patent: US 7,834,086 B2
• Time in Patent Office: Days
• US Class Current: 524/261
• CPC Class Codes: C08K 5/5415 containing at least one Si—O bond
• CPC Class Codes: C08K 5/5419 containing at least one Si—C bond
• CPC Class Codes: C08K 5/5435 containing oxygen in a ring
• CPC Class Codes: C08L 2312/08 by silane
• CPC Class Codes: C09D 133/02 Homopolymers or copolymers of acids; Metal or ammonium salts thereof
• CPC Class Codes: C09D 133/14 of esters containing halogen, nitrogen, sulfur or oxygen atoms in addition to the carboxy oxygen
• CPC Class Codes: Y10S 525/902 Core-shell
• CPC Class Codes: Y10T 428/31511 Of epoxy ether
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane
• CPC Class Codes: Y10T 428/31855 Of addition polymer from unsaturated monomers

Abstract

This invention relates to coating compositions that include water; a latex polymer and a silane coupling agent. The latex polymer preferably comprises acetoacetoxy functionality, or is a multistage latex, or is an acetoacetoxy functional multistage latex. The silane coupling agent is preferably a functionalized silane coupling agent (more preferably an epoxy-functional silane coupling agent). The compositions may be used to coat a variety of substrates, including wood, cement and fiber cement. Articles having the coating applied thereto are also provided.

Claims

1. A coating composition, comprising:

water;

a multistage latex polymer; and

a silane coupling agent.

2. The composition of claim 1, wherein the multistage latex polymer comprises at least one soft stage having a Tg between about −

65 and 30°

C. and at least one hard stage having a Tg between about 30 and 230°

C.

3. The composition of claim 2, wherein the multistage latex polymer comprises 50 to 90 weight % soft stage polymer morphology having a Tg between about −

5 and 25°

C. and 10 to 50 weight % hard stage polymer morphology having a Tg between about 30 and 105°

C., based on total polymer weight.

4. The composition of claim 2, wherein the multistage latex polymer has a gradient Tg.

5. The composition of claim 1, wherein the composition comprises at least 10 weight % multistage latex polymer, based on total solids of the composition.

6. The composition of claim 1, wherein the multistage latex polymer has acetoacetoxy functionality.

7. The composition of claim 6, wherein the multistage latex polymer is made using from 0.5 to 10 weight % acetoacetoxy functional monomer based on the total weight of the multistage latex polymer.

8. The composition of claim 1, wherein the composition includes less than 10 weight % volatile organic compounds.

9. The composition of claim 1, wherein the composition further comprises a low VOC coalescent in an amount of at least 1 weight %.

10. The composition of claim 1, wherein the composition resists crush when two face-to-face coated embossed substrates are subjected to a pressure of 8 kg/cm².

11. The composition of claim 1, wherein the silane coupling agent has the formula:

R₁Si(R₂)_3-n(OR₃)_n

where n is 1, 2 or 3;

the R₁ group is alkyl, cycloalkyl, phenyl, cycloalkylalkyl, alkenylcycloalkyl, alkenylphenyl, or phenylalkyl, wherein R₁ contains at least one functional group and can optionally include a silane oligomer;

each R₂ group is independently hydrogen, alkyl, cycloalkyl, phenyl, cycloalkylalkyl, alkenylcycloalkyl, alkenylphenyl, phenylalkyl, or a silane oligomer, wherein each R₂ group can optionally include OR₃ groups or a functional group;

each R₃ group is independently hydrogen, alkyl, cycloalkyl, phenyl, cycloalkylalkyl, alkenylcycloalkyl, alkenylphenyl, or phenylalkyl.

12. The composition of claim 11, wherein the silane coupling agent is an amino-functional or epoxy-functional coupling agent.

13. The composition of claim 12, wherein the epoxy-functional coupling agent is β

-(3,4 epoxycyclohexyl)-ethyltrimethoxysilane, r-glycidoxypropyl-trimethoxysilane, r-glycidoxypropyl-methylidiethoxysilane, glycidoxypropyltrimethoxysilane, γ

-glycidoxypropyltriethoxysilane, glycidoxypropyltriethoxysilane, glycidoxypropylmethyldimethoxysilane, glycidoxypropylmethyldiethoxysilane, epoxycyclohexylethyltrimethoxysilane, a hydrolyzate of the above or a mixture thereof.

14. The composition of claim 1, wherein the silane coupling agent is present in an amount of from 0.25 to 5 weight percent based on the weight of latex polymer.

15. The composition of claim 14, wherein the silane coupling agent is present in an amount of from 0.5 to 2 weight percent based on the weight of latex polymer.

16. The composition of claim 1, wherein the composition is in the form of a sealer for wood or porous substrates.

17. The composition of claim 1, wherein the composition is in the form of a sealer for cementitious substrates.

18. The composition of claim 1, wherein the composition is applied to a cementitious substrate.

19. A coating composition, comprising:

water;

a latex polymer having acetoacetoxy functionality; and

an epoxy-functional silane coupling agent.

20. The composition of claim 19, wherein the latex polymer is made using from 0.5 to 10 weight % acetoacetoxy functional monomer based on the total weight of the latex polymer.

21. The composition of claim 19, wherein the silane coupling agent has the formula:

R₁Si(R₂)_3-n(OR₃)_n,

where n is 1, 2 or 3;

the R₁ group is alkyl, cycloalkyl, phenyl, cycloalkylalkyl, alkenylcycloalkyl, alkenylphenyl, or phenylalkyl, wherein R₁ contains at least one functional group and may optionally include a silane oligomer;

each R₂ group is independently hydrogen, alkyl, cycloalkyl, phenyl, cycloalkylalkyl, alkenylcycloalkyl, alkenylphenyl, phenylalkyl, or a silane oligomer, wherein each R₂ group can optionally include OR₃ groups or a functional group;

each R₃ group is independently hydrogen, alkyl, cycloalkyl, phenyl, cycloalkylalkyl, alkenylcycloalkyl, alkenylphenyl, or phenylalkyl.

22. The composition of claim 19, wherein the epoxy-functional coupling agent is β

-(3,4 epoxycyclohexyl)-ethyltrimethoxysilane, r-glycidoxypropyl-trimethoxysilane, r-glycidoxypropyl-methylidiethoxysilane, glycidoxypropyltrimethoxysilane, γ

-glycidoxypropyltriethoxysilane, glycidoxypropyltriethoxysilane, glycidoxypropylmethyldimethoxysilane, glycidoxypropylmethyldiethoxysilane, epoxycyclohexylethyltrimethoxysilane, a hydrolyzate of the above or a mixture thereof.

23. A method for preparing a coated substrate comprising

providing a cementitious substrate,

coating at least a portion of the substrate with the coating composition comprising water, a multistage latex polymer, and a silane coupling agent;

and allowing the coating to harden.

24. A method for preparing a coated substrate comprising

providing a cementitious substrate,

coating at least a portion of the substrate with the coating composition, comprising water, a latex polymer having acetoacetoxy functionality, and a epoxy-functional silane coupling agent;

and allowing the coating to harden.

25. A coated substrate, comprising:

a cementitious substrate having at least one major surface; and

a coating composition comprising a mixture of water, a multistage latex polymer, and a silane coupling agent,

applied to the major surface.

26. A coated substrate, comprising:

a cementitious substrate having at least one major surface; and

a coating composition comprising a mixture of water, a latex polymer having acetoacetoxy functionality, and an epoxy-functional silane coupling agent,

applied to the major surface.