Color-plus-clear composite coating compositions containing alkoxysilane functional polymers
AssigneePPG Industries Ohio, Inc.
InventorsKaren D. Donnelly, Charles M. Kania, Michael A. Mayo, William E. Michael, Shanti Swarup
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Abstract
A storage-stable, curable film-forming composition is provided comprising: (i) a crosslinking agent selected from an aminoplast, a blocked polyisocyanate, and mixtures thereof; and (ii) a hydroxyl functional acrylic polymer further containing a plurality of alkoxysilane groups of the structure: ##STR1## wherein R.sub.1 is hydrogen or methyl, and R.sub.2 is a divalent group. The acrylic polymer is prepared in a solvent medium comprising an alcohol. The curable film-forming composition is suitable for use in color-plus-clear composite coating compositions.
Claims40
A storage-stable, curable film-forming composition comprising:
- (i) a crosslinkig agent selected from an aminoplast, a blocked polyisocyanate, and mixtures thereof;
- and
- (ii) an acrylic polymer containing hydroxyl groups which are reactive with the crosslinking agent and further containing a plurality of alkoxysilane groups of the structure:
- ##STR6## wherein R.sub.1 is hydrogen or methyl, and R.sub.2 is a divalent group containing from about 2 to about 20 carbon atoms;
- said acrylic polymer is prepared in a solvent medium comprising an alcohol;
- said acrylic polymer having a total functionality equivalent weight based on hydroxyl plus alkoxy silane of 325 to 575;
- and when a sample of the film-forming composition has been adjusted with solvent to an initial No. 4 Ford cup viscosity of 25 seconds and is maintained at 48.9.degree. C. for 72 hours, the viscosity of the composition increases no more than 60 seconds.
A multi-component composite coating composition comprising a base coat deposited from a pigmented film-forming composition and a transparent top coat applied over the base coat in which the transparent top coat is deposited from a clear film-forming composition comprising:
- (i) a crosslinking agent selected from an aminoplast, a blocked polyisocyanate, and mixtures thereof;
- and
- (ii) an acrylic polymer containing hydroxyl groups that are reactive with the crosslinking agent and further containing a plurality of alkoxysilane groups of the structure:
- ##STR7## wherein R.sub.1 is hydrogen or methyl, and R.sub.2 is a divalent group containing from about 2 to about 20 carbon atoms;
- and wherein said acrylic polymer is prepared in a solvent medium comprising an alcohol;
- said acrylic polymer having a total functionality equivalent weight based on hydroxyl plus alkoxy silane of 325 to 575;
- and when a sample of the film-forming composition has been adjusted with solvent to an initial No. 4 Ford cup viscosity of 25 seconds and is maintained at 48.9.degree. C. for 72 hours, the viscosity of the composition increases no more than 60 seconds.
A storage-stable, curable film-forming composition comprising:
- (i) a crosslinking agent selected from an aminoplast, a blocked polyisocyanate, and mixtures thereof;
- (ii) an acrylic polymer containing a plurality of alkoxysilane groups of the structure:
- ##STR8## wherein R.sub.1 is hydrogen or methyl, and R.sub.2 is a divalent group containing from about 2 to about 20 carbon atoms;
- and
- (iii) an adjuvant polymer or oligomer containing hydroxyl groups that are reactive with the crosslinking agent;
- and wherein the acrylic polymer of component (ii) is prepared in a solvent medium comprising an alcohol:
- said acrylic poler (ii) and said adjuvant polymer (iii) having a total functionality equivalent weight based on hydroxy plus alkoxy silane of 325 to 575 and when a sample of the film-forming composition has been adjusted with solvent to an intial No. 4 Ford cup viscosity of 25 seconds and is maintained at 48.9.degree. C. for 72 hours, the viscosity the composition increases no more than 60 seconds.
A multi-component composite coating composition comprising a base coat deposited from a pigmented film-forming composition and a transparent top coat applied over the base coat in which the transparent top coat is deposited from a clear film-forming composition comprising:
- (i) a crosslinling agent selected from an aminoplast, a blocked polyisocyanate, and mixtures thereof;
- (ii) an acrylic polymer containing a plurality of alkoxysilane groups of the structure:
- ##STR9## wherein R.sub.1 is hydrogen or methyl, and R.sub.2 is a divalent group containing from about 2 to about 20 carbon atoms;
- and
- (iii) an adjuvant polymer or oligomer containing hydroxyl groups that are reactive with the crosslinling agent;
- and wherein the acrylic polymer of component (ii) is prepared in a solvent medium comprising all alcohol;
- said arcylic polymer (ii) and said adjuvant polymer (iii) having a total functionally equvalent weight based on hydroxyl plus alkoxy silane of 325 to 575 and when a sample of the film-forming composition has been adjusted with solvent to an initial No. 4 Ford cup viscosity of 25 seconds and is maintained at 48.9.degree. C. for 72 hours, the viscosity of the composition increases no more than 60 seconds.
Dependencies are inferred from the claim text.