Composition for providing a non-wettable coating, articles coated therewith, and methods for preparing the same

• US 6,506,496 B1
• Filed: 03/29/1995
• Issued: 01/14/2003
• Est. Priority Date: 03/29/1994
• Status: Expired due to Fees

• Current Assignee: Saint-Gobain Glass France (Compagnie De Saint-Gobain)
• Original Assignee: Saint-Gobain Glass France (Compagnie De Saint-Gobain)
• Inventors: Frugier, Dominique, Chartier, Pascal, Leclaire, Yves, Vaneeckhoutte, Philippe, Robert, Anne
• Primary Examiner(s): Moore; Margaret G.
• Application Number:
  US08/412,573
• Time in Patent Office: 2,848 Days
• Field of Search: 528/42 524/858,868,837 428/447 427/387
• US Class Current: 428/447
• CPC Class Codes: C03C 17/30 with silicon-containing compounds
• CPC Class Codes: G02B 1/105 Protective coatings
• CPC Class Codes: G02B 1/14 Protective coatings, e.g. hard coatings
• CPC Class Codes: G02B 1/18 Coatings for keeping optical surfaces clean, e.g. hydrophobic or photo-catalytic films G02B1/16 takes precedence
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane

Abstract

A heat-settable composition for a coating which is hydrophobic, oleophobic and resistant to abrasion, wherein the coating contains a hydrolyzate obtained from a solution of:

one or more epoxidized alkoxysilane having alkoxy groups which are directly linked to the silicon atom;

a hydrolyzable, non-epoxidized silane;

colloidal silica;

a catalyst which promotes cleavage of an epoxy bond; and

at least one fluorinated hydrolyzable alkylsilane; and the use of the heat-settable composition in the preparation of a coated substrate of organic glass or mineral glass material, coated with a coating obtained from the heat-settable composition, with the substrate preferably being a pane (comprised of glass or a polymeric material) or an ophthalmic lens.

Claims

1. A coated substrate comprising a substrate of organic glass or mineral glass material, having a coating which is hydrophobic, oleophobic and resistant to abrasion, wherein the coating is obtained, from a composition comprising a hydrolyzate obtained from a solution, by a method comprising the steps:

hydrolyzing and partially condensing one or more epoxidized alkoxysilanes and a non-epoxidized silane;

adding, separately or simultaneously, colloidal silica and a catalyst; and

adding one or more fluorinated alkylsilanes, present in an amount of from 0.1-6.0 wt % based on total dry matter in the solution, during the hydrolysis or partial condensation of the silanes or during both the hydrolysis and partial condensation of the silanes;

wherein the fluorinated alkylsilane is perfluoroalkylsilane having the formula (I);

2. The coated substrate of claim 1, wherein the perfluoroalkylsilane is a member selected from the group consisting of the perfluoroalkyl alkoxysilanes according to the following formulas:

3. The coated substrate of claim 1, wherein the fluorinated alkylsilane is present in an amount of from 0.1-4.0 wt % based on total dry matter in the solution.

4. The coated substrate of claim 1, wherein the epoxidized alkoxysilane has the formula (II):

 

wherein p is 0 or 1,

r is 0 1, or 2,

s is an integer in the range 1-6,

M represents H or an alkyl group having 1 to 4 C atoms, and

M′ and

M″

represent alkyl groups having 1 to 3 C atoms; and

the non-epoxidized silane has the formula (III);

 

where N and N′

are organic groups connected to the silicon atom by a Si—

C bond, which groups do not comprise any group which reacts with hydrolyzed silanes present in the composition, and

Q and Q′

are hydrolyzable moieties.

5. The coated substrate of claim 1, wherein the epoxidized alkoxysilane is a member selected from the group consisting of:

gamma-glycidoxypropyl-trimethoxysilane;

gamma-glycidoxypropyl-triethoxysilane,

gamma-glycidoxypropyl-methyl-dimethoxysilane, and

gamma-glycidoxypropyl-methyl-diethoxysilane.

6. The coated substrate of claim 1, wherein the non-epoxidized alkoxysilane is a dialkoxysilane wherein the groups N and N′

are each, independently, selected from the group consisting of alkyl groups having 1-10C atoms and aryl groups having 6-10C atoms.

7. The coated substrate of claim 1, wherein the catalyst is a chelate of aluminum.

8. The coated substrate of claim 1, wherein the solution further comprises a silicon surfactant or a fluorinated surfactant.

9. The coated substrate of claim 1, wherein the composition comprises a hydrolyzate obtained from a solution comprising:

30-50% of one or more epoxidized alkoxysilanes,

30-55% of colloidal silica,

10-20% of a non-epoxidized hydrolyzable silane;

0.1-6.0% of one or more fluorinated hydrolyzable alkylsilanes; and

0.1-5.0% of a catalyst, the percentages given being percentages by weight with respect to the dry matter of the solution.

10. The coated substrate of claim 1, wherein the composition comprises a hydrolyzate obtained from a solution comprising:

35-40% of one or more epoxidized alkoxysilanes;

40-55% of colloidal silica;

10-15% of a non-epoxidized hydrolyzable alkoxysilane,

0.1-4.0% of one or more fluorinated hydrolyzable alkylsilanes; and

0.1-5.0% of a catalyst, the percentages given being percentages by weight with respect to the dry matter of the solution.

11. The coated substrate of claim 1, wherein the composition comprises a hydrolyzate obtained from a solution comprising:

35-40% of glycidoxypropyl-trimethoxysilane;

40-55% of colloidal silica;

10-15% of dimethyldiethoxysilane;

0.1-4% of one or more perfluoroalkyl alkoxysilanes selected from the group consisting of perfluoroalkyl alkoxysilanes according to the following formulas;

12. The coated substrate of claim 1, wherein the substrate is a pane comprised of glass or a polymeric material.

13. A pane according to claim 12, wherein the coating has a thickness in the range 0.1-10.0 micron.

14. The coated substrate according to claim 1, wherein the substrate is an ophthalmic lens.

15. A method of fabricating a substrate pane comprised of glass or polymeric material, and having a coating which is hydrophobic, oleophobic and resistant to abrasion, wherein the method comprises the steps:

preparing at least one of the faces of the substrate thereby eliminating essentially all organic contaminants adsorbed on the surface of the substrate;

contacting the prepared face of the substrate with a solution comprising;

one or more epoxidized alkoxysilanes,

a non-epoxidized hydrolyzable silane, colloidal silica,

a catalyst, and

at least one fluorinated hydrolyzable alkylsilane, present in an amount of from 0.1-6.0 wt % based on a total dry matter in the solution,

wherein the fluorinated alkylsilane is perfluoroalkylsilane having the formula (I);

16. A method according to claim 15, wherein the crosslinking of the gel is brought about by maintaining the gel at a temperature in the range of 60-200°

C. for at least one hour.

17. A method of producing a coating on a substrate which is hydrophobic, oleophobic and resistant to abrasion, wherein the method comprises the steps of forming a composition comprising a hydrolyzate obtained from a solution by:

hydrolyzing and partially condensing one or more epoxidized alkoxysilanes and a nonepoxidized silane;

adding, separately or simultaneously, colloidal silica and a catalyst; and

adding one or more fluorinated alkylsilanes, present in an amount of from 0.1-6.0 wt. % based on total dry matter in the solution, during the hydrolysis or partial condensation of the silanes or during both the hydrolysis and partial condensation of the silanes;

wherein the fluorinated alkylsilane is perfluoroalkylsilane having the formula (1);

18. A method according to claim 17, wherein the hydrolysis of the epoxidized and non-epoxidized silanes is obtained by adding an acidic solution in a stoichiometric amount with respect to the silanol groups of the silanes.

19. A method according to claim 18, wherein the on or more epoxidized alkoxysilanes have the formula (II):

wherein p is 0 or 1,

r is 0, 1, or 2,

s is an integer in the range 1-6,

M represents H or an alkyl group having 1 to 4 C atoms; and

M′ and

M″

represent alkyl groups having 1 to 3 C atoms;

the non-epoxidized alkoxysilane has the formula (II);

 

wherein N and N′

are each, independently, alkyl groups having 1-10 C atoms or aryl groups having 6-10 C atoms, and

Q and Q′

are hydrolyzable moieties.