US4942065A
Expired / Lapsed
US
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Method for curing silicone coatings on plastic substrates, and curable compositions related thereto
Assignee: SABIC Global Technologies BV
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Filing: 1990-01-16
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Granted: 1990-07-17
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Expires: 2010-01-16
Abstract
Abstract An improved method for forming a protective coating on a plastic substrate is disclosed, comprising the application of a curable coating composition which contains at least one alkyltrialkoxysilane in a water/organic solvent dispersion of the colloidal silica onto the substrate, and then curing the composition at elevated temperatures with an effective amount of a tetrabutylammonium carboxylate catalyst such as tetra-n-butylammonium acetate. This invention also includes improved curable silicone coating compositions containing such a catalyst.
Inventors
- 👤 Arnold Factor
- 👤 Gautam A. Patel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:08
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/16; C08K5/17; C08K5/19; C09; C09D; C09D183/00; C09D183/04
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
104 words
A method for forming a protective coating on a plastic substrate, comprising applying to the substrate a curable coating composition which comprises a dispersion of (I) colloidal silica; (II) at least one alkyltrialkoxysilane; and (III) any reaction products of (I) and (II), in a mixture of water with at least one organic solvent; and curing the coating composition at elevated temperatures with an effective amount of a tetrabutylammonium carboxylate catalyst of the formula ##STR5## wherein R is selected from the group consisting of hydrogen alkyl groups containing about 1 to about 8 carbon atoms, and aromatic groups containing about 6 to 20 carbon atoms.
Claim 2
Independent Claim
104 words
A method for forming a protective coating on a plastic substrate, comprising applying to the substrate a curable coating composition which comprises a dispersion of (I) colloidal silica; (II) at least one alkyltrialkoxysilane; and (III) any reaction products of (I) and (II), in a mixture of water with at least one organic solvent; and curing the coating composition at elevated temperatures with an effective amount of a tetrabutylammonium carboxylate catalyst of the formula ##STR5## wherein R is selected from the group consisting of hydrogen alkyl groups containing about 1 to about 8 carbon atoms, and aromatic groups containing about 6 to 20 carbon atoms.
Claim 3
Dependent Claim
14 words
The method of claim 1 wherein R contains about 1 to 4 carbon atoms.
Claim 4
Dependent Claim
14 words
The method of claim 2 wherein the catalyst is tetra-n-butylammonium acetate or tetra-n-butylammonium formate.
Claim 5
Dependent Claim
25 words
The method of claim 1 wherein the catalyst is employed at a concentration of about 0.1 to about 1.0 weight percent, based on coating solids.
Claim 6
Dependent Claim
24 words
The method of claim 4 the catalyst is employed at a concentration of about 0.3 to about 0.6 weight percent, based on coating solids.
Claim 7
Dependent Claim
34 words
The method of claim 4 curing is carried out by heating the coated substrate at a temperature of from about 80° C. to about 130° C. for about 15 minutes to about 180 minutes.
Claim 8
Dependent Claim
29 words
The method of claim 6 wherein curing is carried out at a temperature of from about 100° C. to 130° C. for about 30 minutes to about 60 minutes.
Claim 9
Dependent Claim
21 words
The method of claim 1 wherein an acrylic primer is on the substrate prior to application of the curable coating composition.
Claim 10
Dependent Claim
32 words
The method of claim 1 wherein the substrate is a material selected from the group consisting of polycarbonate, acrylic, polyphenylene ether, polysulfone, polyimide, polyester, copolyestercarbonate, cellulose acetate, and poly(diethylene glycol bis(allyl carbonate)).
Claim 11
Dependent Claim
30 words
The method of claim 1 wherein the coating composition further includes an effective amount of a silylated ultraviolet light absorber capable of co-reacting with the silane, components in the composition.
Claim 12
Dependent Claim
54 words
The method of claim 1 wherein the coating composition has an alkaline pH and comprises: (A) about 60% to 90% by weight of an alkyltrialkoxysilane; (B) about 10% to 40% by weight solids of colloidal silica in a water/organic solvent dispersion of ammonium-stabilized colloidal silica; and (C) an effective amount of a hydrolysis catalyst.
Claim 13
Dependent Claim
10 words
The method of claim 11 wherein the alkyltrialkoxysilane is methyltrimethoxysilane.
Claim 14
Dependent Claim
18 words
The method of claim 12 wherein the pH of the coating composition is about 7.1 to about 7.8.
Claim 15
Dependent Claim
73 words
The method of claim 1 wherein the coating composition has an alkaline pH and comprises: (A) about 80% to 95% by weight of a mixture of a dialkyldialkoxysilane and an alkyltrialkoxysilane in a weight ratio within the range of about 1:99 to 15:85; (B) about 5% to 20% by weight solids of colloidal silica in a water/organic solvent dispersion of ammonium stabilized colloidal silica; and (C) an effective amount of a hydrolysis catalyst.
Claim 16
Dependent Claim
23 words
The method of claim 14 wherein the colloidal silica has an average particle diameter no greater than about 5 to about 10 millimicrons.
Claim 17
Dependent Claim
15 words
The method of claim 14 wherein the dialkyldialkoxysilane is dimethyldimethoxysilane, and the alkyltrialkoxysilane is methyltrimethoxysilane.
Claim 18
Dependent Claim
22 words
The method of claim 1 wherein the coating composition contains sufficient acid to provide a pH of about 3.0 to about 6.0.
Claim 19
Dependent Claim
65 words
The method of claim 17 wherein the coating composition upon equilibration comprises a dispersion of colloidal silica in a lower aliphatic alcohol/water solution of the partial condensate of a silanol having the formula R'Si(OH) 3 , wherein R' is selected from the group consisting of alkyl groups containing about 1-3 carbon atoms, the vinyl group, the 3,3,3-trifluoropropyl group, the gamma-glycidoxypropyl group, and the gamma-methacryloxypropyl group.
Claim 20
Dependent Claim
12 words
The method of claim 18, wherein the silanol is derived from methyltrimethoxysilane.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-16 | 1994-01-15 | 1994-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-16 | 1998-01-15 | 1998-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-16 | 2002-01-15 | 2002-07-17 | $7700.00 | Window Closed / Lapsed |