Coating composition

• US 6,635,735 B1
• Filed: 12/17/2001
• Issued: 10/21/2003
• Est. Priority Date: 06/16/1999
• Status: Expired due to Fees

• Current Assignee: Nihon Yamamura Glass Company Limited
• Original Assignee: Nihon Yamamura Glass Company Limited
• Inventors: Wakabayashi, Hajimu, Zhang, Zuyi
• Primary Examiner(s): Dawson, Robert
• Assistant Examiner(s): PENG, KUO LIANG
• Application Number:
  US10/009,810
• Time in Patent Office: 673 Days
• Field of Search: 528/12, 528/14, 528/26, 528/32, 528/16, 528/43, 524/588, 524/858, 524/863, 502/171
• US Class Current: 528/14
• CPC Class Codes: C08L 2666/52 Metal-containing compounds
• CPC Class Codes: C08L 2666/54 Inorganic substances
• CPC Class Codes: C09D 183/04 Polysiloxanes

Abstract

A coating composition having (A) an alcohol dispersion which includes silica having the hydrophobic surface and dispersed in an alcohol dispersion medium, the content of silica in a solid substance being 80% by weight or more; (B) a solution including a silicone oligomer which is obtained by a reaction of an alkoxysilane with water and has an average structural unit represented by R¹_nSiO_x/2(OH)_y (OR²⁾_z (R¹ representing an alkyl group, phenyl group or vinyl group, R² representing an alkyl group and n, x, y and z representing numbers satisfying relations: 0.8≦n≦1.7, 2<x<3.2, y>0, z>0 and y+z=4−n−x); and (C) a curing agent. The coating composition exhibits excellent storage stability after the curing agent is added, suppresses aggregation of fine silica particles in spray coating and provides coating films having a high hardness and exhibiting excellent weatherability, water resistance, chemical resistance and adhesion.

Claims

1. A coating composition which comprises:

(A) an alcohol dispersion which comprises silica having a hydrophobic surface and dispersed in an alcohol dispersion medium and has a content of silica in a solid substance of 80% by weight or more;

(B) a solution comprising a silicone oligomer which is obtained by a reaction of an alkoxysilane with water and has an average structural unit represented by;

2. A coating composition according to claim 1, wherein a content of component (A) is 10 to 70% by weight as a solid substance and a content of component (B) is 90 to 30% by weight as a solid substance each based on a total amount of component (A) and component (B) as solid substances and a content of component (C) is 1 to 40 parts by weight per 100 parts by weight of a total amount of component (A) and component (B) as solid substances.

3. A coating composition according to claim 1, wherein the silica having a hydrophobic surface in component (A) is obtained by a reaction of fine silica particles with an organoalkoxysilane or an organohalosilane each having a structure represented by:

4. A coating composition according to claim 1, wherein the silica having a hydrophobic surface in component (A) is obtained by a reaction, in a presence of an amine-based silane coupling agent, of fine silica particles with an organoalkoxysilane having a structure represented by:

5. A coating composition according to claim 1, wherein the silicone oligomer in component (B) is prepared by using a metal chelate compound as a catalyst.

6. A coating composition according to claim 5, wherein a ligand of the metal chelate compound is at least one compound selected from β

-diketones and cyclic polyethers having a large ring, wherein said cyclic polyethers are selected from the group consisting of 18-crown-6-potassium chelate compound salts, 12-crown-4-lithium chelate compound salts and 15-crown-5-sodium chelate compound salts.

7. A coating composition according to claim 1, wherein the silicone oligomer in component (B) is prepared by using, as a self catalyst, a solution comprising a silicon compound which is soluble in a hydrophilic organic solvent and has an average structural unit represented by:

8. A coating composition according to claim 1, wherein component (C) is a solution comprising a complex having a structure represented by:

9. A coating composition according to claim 8, wherein the chelating agent is a β

-diketone.

10. A coating composition according to claim 1, wherein component (C) comprises a compound which is selected from carboxylic acids, alcohols having carbonyl group and alcohols having ether group and has a boiling point of 200°

C. or lower.