Optically transparent UV-protective coatings

• US 6,264,859 B1
• Filed: 04/14/1993
• Issued: 07/24/2001
• Est. Priority Date: 10/03/1986
• Status: Expired due to Fees

• Current Assignee: PPG Industries Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Inventors: Lin, Chia-Cheng, Basil, John D., Hunia, Robert M.
• Primary Examiner(s): TUCKER, PHILIP C
• Application Number:
  US08/048,866
• Time in Patent Office: 3,023 Days
• Field of Search: 106/287.13, 106/287.14, 106/287.15, 106/287.16, 106/287.18, 252/582, 252/588, 252/589
• US Class Current: 252/588
• 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 organoalkoxysilane and/or other metal alkoxide in combination with the reaction product of cerium oxide and tetraalkylsilicate.

Claims

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

a. a partially hydrolyzed alkoxide comprised of the general formula R_xSi(OR′

)_z-x wherein R is an organic radical and R′

is selected from the group consisting of methyl, ethyl, propyl, and butyl and z is the valence of Si, and x is less than z; and

b. the reaction product of tetraalkylsilicate and cerium oxide formed from combining tetraalkylsilicate and cerium oxide, increasing the pH, and adding water.

2. A composition according to claim 1 wherein R is selected from the group consisting of alkyl, vinyl, phenyl, methoxyethyl, γ

-glycidoxypropyl and γ

-methacryloxypropyl, and x is 1.

3. A composition according to claim 2, wherein said alkoxide comprises methyl triethoxysilane.

4. A composition according to claim 2, wherein said alkoxide comprises γ

-glycidoxypropyl trimethoxysilane.

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

a. a partially hydrolyzed alkoxide of the general formula R_xM(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 except when M is silicon; and

b. the reaction product of tetraalkylsilicate and cerium oxide formed from combining tetraalkylsilicate and cerium oxide, increasing the pH, and adding water, wherein said cerium oxide comprises colloidal particles in aqueous dispersion.

6. A composition according to claim 5, wherein said particles have an average particle size of less than 10 nanometers.

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

a. a partially hydrolyzed alkoxide of the general formula R_xM(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 except when M is silicon;

b. the reaction product of tetraalkylsilicate and cerium oxide formed from combining tetraalkylsilicate and cerium oxide, increasing the pH, and adding water; and

c. silica.

8. A composition according to claim 7, wherein said silica comprises colloidal particles in aqueous dispersion.

9. A composition according to claim 8, wherein said silica particles have an average particle size of 10 to 20 nanometers.