Optically transparent UV-protective coatings

• US 4,799,963 A
• Filed: 10/03/1986
• Issued: 01/24/1989
• Est. Priority Date: 10/03/1986
• Status: Expired due to Term

• Current Assignee: PPG Industries Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Incorporated (Nouryon BV)
• Inventors: Lin, Chia-Cheng, Basil, John D., Hunia, Robert M.
• Primary Examiner(s): Morris, Theodore
• Application Number:
  US06/914,857
• Time in Patent Office: 844 Days
• Field of Search: 106/287.12, 106/287.14, 106/287.16, 106/287.24, 106/287.17, 106/287.13, 106/287.18, 106/299
• US Class Current: 106/287.13
• CPC Class Codes: C08L 2666/54 Inorganic substances
• CPC Class Codes: C09D 183/04 Polysiloxanes
• CPC Class Codes: C09D 183/14 in which at least two but not all the silicon atoms are connected by linkages other than oxygen atoms C09D183/10 takes precedence

Abstract

An ultraviolet radiation resistant coating is disclosed comprising cerium oxide in an inorganic oxide matrix formed by the hydrolysis and condensation of an alkoxysilane and/or other metal alkoxide.

Claims

1. An optically transparent coating composition which reduces transmission of ultraviolet radiation consisting essentially of:

a. a partially hydrolyzed alkoxide of the general formula R_x M(OR'"'"')_z-x wherein R is an organic radical, M is selected from the group consisting of silicon, aluminum, titanium, zironium and mixtures thereof, R'"'"' is a low molecular weight alkyl radical, z is the valence of M and x is less than z and may be zero; and

b. colloidal cerium oxide.

2. A composition according to claim 1, wherein said alkoxide comprises the general formula R_x Si(OR'"'"')_4-x and R'"'"' is selected from the group consisting of methyl, ethyl, propyl, and butyl.

3. A composition according to claim 2 wherein R is selected from the group consisting of alkyl, vinyl, phenyl, methoxyethyl, γ

-glycidoxypropyl and γ

-methacryloxypropyl, and x is 1.

4. A composition according to claim 3, wherein said alkoxide comprises methyl triethoxysilane.

5. A composition according to claim 3, wherein said alkoxide comprises γ

-glycidoxypropyl trimethoxysilane.

6. A composition according to claim 1, wherein said cerium oxide comprises colloidal particles in aqueous dispersion.

7. A composition according to claim 6, wherein said particles have an average particle size of less than 10 nanometers.

8. A composition according to claim 1, further comprising silica.

9. A composition according to claim 8, wherein said silica comprises colloidal particles in aqueous dispersion.

10. A composition according to claim 9, wherein said silica particles have an average particle size of 10 to 20 nanometers.

11. A method of preparing an optically transparent ultraviolet resistant coating composition comprising the steps of:

a. at least partially hydrolyzing an alkoxide of the general formula R_x M(OR'"'"')_z-x wherein R is an organic radical, M is selected from the group consisting of silicon, aluminum, titanium, zirconium and mixtures thereof, R'"'"' is a low molecular weight alkyl radical, z is the valence of M and x is less than z and may be zero; and

b. adding to said at least partially hydrolyzed alkoxide a colloidal dispersion of cerium oxide.

12. A method according to claim 11, wherein said alkoxide comprises the general formula R_x Si(OR'"'"')_4-x and R'"'"' is selected from the group consisting of methyl, ethyl, propyl and butyl.

13. A method according to claim 12, wherein R is selected from the group consisting of alkyl, vinyl, phenyl, methoxyethyl, γ

-glycidoxypropyl and γ

-methacryloxypropyl, and x is 1.

14. A method according to claim 13, wherein said alkoxide comprises methyl triethoxysilane.

15. A method according to claim 13, wherein said alkoxide comprises -glycidoxypropyl trimethoxysilane.

16. A method according to claim 11, wherein said cerium oxide comprises colloidal particles in aqueous dispersion.

17. A method according to claim 16, wherein said particles have an average particle size of 5 to 15 microns.

18. A method according to claim 11, further comprising the step of adding silica to said partially hydrolyzed alkoxide.

19. A method according to claim 18, wherein said silica comprises colloidal particles in aqueous dispersion.

20. A method according to claim 19, wherein said silica particles have an average particle size of 10 to 20 microns.