Weatherable compositions useful as coatings, method, and articles coated therewith

• US 6,350,521 B1
• Filed: 12/22/1999
• Issued: 02/26/2002
• Est. Priority Date: 12/22/1999
• Status: Expired due to Term

• Current Assignee: SABIC Global Technologies BV (Government of Saudi Arabia)
• Original Assignee: General Electric Company
• Inventors: Gillette, Gregory Ronald, Webb, Karen Kueck, Chen, Mao, Pickett, James Edward
• Primary Examiner(s): Boykin, Terressa M.
• Application Number:
  US09/469,703
• Time in Patent Office: 797 Days
• Field of Search: 428/412, 428/447
• US Class Current: 428/412
• CPC Class Codes: C08J 2433/00 Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Derivatives of such polymers
• CPC Class Codes: C08J 7/0427 with only one layer of a composition containing a polymer binder with more layers C08J7/042
• CPC Class Codes: C08K 5/132 Phenols containing keto groups , e.g. benzophenones
• CPC Class Codes: C08K 5/5419 containing at least one Si—C bond
• CPC Class Codes: Y10T 428/31507 Of polycarbonate

Abstract

Thermoplastic substrates subject to color instability and loss of physical properties resulting from exposure to ultraviolet radiation, such as polycarbonate, are coated with a protective coating comprising at least one thermoplastic acrylic polymer such as poly(methyl methacrylate) in combination with two ultraviolet absorbing compounds: a substituted resorcinol such as 4,6-dibenzoylresorcinol and a silylated substituted resorcinol such as 2-(3-triethoxysilylpropyl)-4,6-dibenzoylresorcinol. The silylated substituted resorcinol is used in a minor proportion effective to improve solubility and compatibility of the substituted resorcinol.

Claims

1. A thermoplastic composition comprising the following and any reaction products thereof:

at least one thermoplastic acrylic polymer in combination with a minor proportion, effective to improve weatherability, of

(A) at least one substituted resorcinol of the formula

 

and

(B) at least one silylated substituted resorcinol of the formula

 

wherein;

each Z is independently an unsubstituted or substituted aromatic radical,

R¹ is hydrogen, a C_1-10 alkyl radical or Z—

C(O)—

,

R² is a divalent C_1-10 aliphatic hydrocarbon radical,

each R³ and R⁴ is independently a C_1-12 alkyl radical, and

n is 0-3;

component B being present in a minor proportion effective to improve solubility and compatibility of component A.

2. The composition according to claim 1 wherein the acrylic polymer is a poly(alkyl acrylate) or poly(alkyl methacrylate).

3. The composition according to claim 2 wherein the acrylic polymer is poly(methyl methacrylate).

4. The composition according to claim 1 wherein each Z is phenyl.

5. The composition according to claim 4 wherein R¹ is hydrogen.

6. The composition according to claim 4 wherein R² is trimethylene.

7. The composition according to claim 6 wherein n is 0.

8. The composition according to claim 7 wherein R⁴ is methyl or ethyl.

9. The composition according to claim 1 further comprising a solvent.

10. The composition according to claim 9 wherein the solvent is an alcohol, hydroxy ether, mixture of an alcohol or hydroxy ether with water, liquid aliphatic or alicyclic hydrocarbon or chlorofluorocarbon.

11. The composition according to claim 10 wherein the solvent is 1-methoxy-2-propanol.

12. The composition according to claim 1 wherein the combination of components A and B is present in the amount of about 25-40% by weight based on total solids, and component B is present in the amount of about 20-40% by weight of combined components A and B.

13. A thermoplastic composition comprising the following and any reaction products thereof:

poly(methyl methacrylate) in combination with (A) 4,6-dibenzoylresorcinol and (B) 2-(3-triethoxysilylpropyl)-4,6-dibenzoylresorcinol;

components A and B combined being present in the amount of about 25-40% by weight based on total solids and component B in the amount of about 20-40% by weight of combined components A and B.

14. An article comprising a thermoplastic substrate and a protective coating thereon, said coating comprising the following and any reaction products thereof:

at least one thermoplastic acrylic polymer in combination with a minor proportion, effective to improve weatherability, of

(A) at least one substituted resorcinol of the formula

 

and

(B) at least one silylated substituted resorcinol of the formula

 

wherein;

each Z is independently an unsubstituted or substituted aromatic radical,

R¹ is hydrogen, a C_1-10 alkyl radical or Z—

C(O)—

,

R² is a divalent C_1-10 aliphatic hydrocarbon radical,

each R³ and R⁴ is independently a C_1-12 alkyl radical, and

n is 0-3;

component B being present in a minor proportion effective to improve solubility and compatibility of component A.

15. The article according to claim 14 wherein the thermoplastic substrate is polycarbonate.

16. The article according to claim 15 wherein the acrylic polymer is poly(methyl methacrylate).

17. The article according to claim 15 wherein each Z is phenyl and R¹ is hydrogen.

18. The article according to claim 17 wherein R² is trimethylene and n is 0.

19. The article according to claim 18 wherein R⁴ is methyl or ethyl.

20. The article according to claim 15 wherein the combination of components A and B is present in the amount of about 25-40% by weight based on total solids, and component B is present in the amount of about 20-40% by weight of combined components A and B.

21. An article comprising a bisphenol A polycarbonate substrate and a protective coating thereon, said coating comprising the following and any reaction products thereof:

poly(methyl methacrylate) in combination with (A) 4,6-dibenzoylresorcinol and (B) 2-(3-triethoxysilylpropyl)-4,6-dibenzoylresorcinol;

components A and B combined being present in the amount of about 25-40% by weight based on total solids and component B in the amount of about 20-40% by weight of combined components A and B.

22. A method to improve the weatherability of an article comprising a thermoplastic substrate which comprises applying a protective coating thereon, said coating comprising the following and any reaction products thereof:

at least one thermoplastic acrylic polymer in combination with a minor proportion, effective to improve weatherability, of

(A) at least one substituted resorcinol of the formula

 

and

(B) at least one silylated substituted resorcinol of the formula

 

wherein;

each Z is independently an unsubstituted or substituted aromatic radical,

R¹ is hydrogen, a C_1-10 alkyl radical or Z—

C(O)—

,

R² is a divalent C_1-10 aliphatic hydrocarbon radical,

each R³ and R⁴ is independently a C_1-12 alkyl radical, and

n is 0-3;

component B being present in a minor proportion effective to improve solubility and compatibility of component A.

23. A method to improve the weatherability of an article comprising a bisphenol A polycarbonate substrate which comprises applying a protective coating thereon, said coating comprising the following and any reaction products thereof:

poly(methyl methacrylate) in combination with (A) 4,6-dibenzoylresorcinol and (B) 2-(3-triethoxysilylpropyl)-4,6-dibenzoylresorcinol;

components A and B combined being present in the amount of about 25-40% by weight based on total solids and component B in the amount of about 20-40% by weight of combined components A and B.