High performance aqueous coating compositions

• US 8,658,286 B2
• Filed: 10/15/2010
• Issued: 02/25/2014
• 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: Killilea, T. Howard, Wildman, Michael C., Johnson, Bruce A., Weber, Carl H.
• Primary Examiner(s): SASTRI, SATYA B
• Application Number:
  US12/905,815
• Publication Number:
  US 20110033709A1
• Time in Patent Office: 1,229 Days
• Field of Search: 524/504, 524/560, 524/523, 524/458, 428/500, 428/447, 428/413, 427/387
• US Class Current: 428/500
• 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 coated substrate, comprising:

a cementitious substrate having at least one major surface; and

a coating composition applied to the major surface, the coating composition comprising a mixture of water, a multistage latex polymer having acetoacetoxy functionality, and about 0.25 to about 10 weight % based on the total latex polymer weight of an epoxy-functional silane coupling agent that provides improved resistance to delamination from the substrate when a hardened coating made from the composition is exposed for one hour at 60°

C. to 1,034 kPa pressure from an automotive tire tread section heated to 60°

C.

2. The substrate 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 substrate 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 substrate of claim 1, wherein the multistage latex polymer has a gradient Tg.

5. The substrate of claim 1, wherein the multistage latex polymer was made from 0.5 to 10 weight % acetoacetoxy functional monomer based on the total polymer weight.

6. The substrate of claim 1, wherein the coating composition comprises at least about 10 weight % multistage latex polymer based on total coating composition solids, and about 0.25 to 5 weight % silane coupling agent based on the total latex polymer weight.

7. The substrate of claim 1, wherein the coating composition includes less than 10 weight % volatile organic compounds and at least 1 weight % low VOC coalescent.

8. 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.

10. The substrate of claim 8, wherein the 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.

11. The substrate of claim 8, wherein the latex polymer was made from 0.5 to 10 weight % acetoacetoxy functional monomer based on the total polymer weight.

12. The substrate of claim 8, wherein the coating composition comprises at least about 10 weight % latex polymer based on total coating composition solids, and about 0.25 to 5 weight % silane coupling agent based on the total latex polymer weight.

13. The substrate of claim 8, wherein the coating composition includes less than 10 weight % volatile organic compounds and at least 1 weight % low VOC coalescent.

9. A coated substrate, comprising:

a cementitious substrate having at least one major surface; and

a coating composition applied to the major surface, the coating composition comprising a mixture of water, a latex polymer having acetoacetoxy functionality, and about 0.25 to about 10 weight % based on the total latex polymer weight of an epoxy-functional silane coupling agent that provides improved resistance to delamination from the substrate when a hardened coating made from the composition is exposed for one hour at 60°

C. to 1,034 kPa pressure from an automotive tire tread section heated to 60°

C.

14. A method for preparing a coated substrate comprising

providing a cementitious substrate;

coating at least a portion of the substrate with a coating composition comprising water, a multistage latex polymer having acetoacetoxy functionality, and about 0.25 to about 10 weight % based on the total latex polymer weight of an epoxy-functional silane coupling agent; and

allowing the coating to harden

wherein the silane coupling agent provides improved resistance to delamination from the substrate when the hardened coating is exposed for one hour at 60°

C. to 1,034 kPa pressure from an automotive tire tread section heated to 60°

C.

15. A method for preparing a coated substrate comprising

providing a cementitious substrate;

coating at least a portion of the substrate with a coating composition comprising water, a latex polymer having acetoacetoxy functionality, and about 0.25 to about 10 weight % based on the total latex polymer weight of an epoxy-functional silane coupling agent; and

allowing the coating to harden

wherein the silane coupling agent provides improved resistance to delamination from the substrate when the hardened coating is exposed for one hour at 60°

C. to 1,034 kPa pressure from an automotive tire tread section heated to 60°

C.