Primer compositions

• US 5,985,371 A
• Filed: 12/04/1997
• Issued: 11/16/1999
• Est. Priority Date: 12/05/1996
• Status: Expired due to Term

• Current Assignee: Shin-Etsu Chemical Company Limited
• Original Assignee: Shin-Etsu Chemical Company Limited
• Inventors: Kondou, Takashi, Fujioka, Kazutoshi
• Primary Examiner(s): Marquis, Melvyn I.
• Assistant Examiner(s): Milstead, Mark W.
• Application Number:
  US08/985,084
• Time in Patent Office: 712 Days
• Field of Search: 427/387, 528/15, 528/17, 528/24, 528/31, 524/265, 524/268, 524/267
• US Class Current: 427/387
• CPC Class Codes: C08L 2666/28 Non-macromolecular organic substances
• CPC Class Codes: C08L 83/00 Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
• CPC Class Codes: C09D 183/04 Polysiloxanes

Abstract

The invention provides a primer composition comprising (I) an organoalkoxysilane or siloxane, (II) an organohydrogensiloxane having an SiH group and an alkoxysilyl group, and (III) an organic titanate. Also provided is a primer composition comprising (A) an alkenyl-containing organopolysiloxane, (B) an organopolysiloxane, (C) an organoalkoxysilane or siloxane, (D) an organohydrogensiloxane having an SiH group and an alkoxysilyl group, (E) a platinum catalyst, (F) an organic titanate, and (G) an organic peroxide. The primer compositions have sufficient adhesion to join thermoset silicone rubber to various substrates.

Claims

1. A primer composition comprising

(I) 100 parts by weight of an organoalkoxysilane or siloxane of the following average compositional formula (1):

space="preserve" listing-type="equation">R.sup.1.sub.a R.sup.2.sub.b (OR.sup.3).sub.c SiO.sub.(4-a-b-c)/2 (1)

wherein R¹ is a substituted or unsubstituted monovalent hydrocarbon group, R² is a monovalent organic group having a functional group, R³ is an unsubstituted or alkoxy-substituted alkyl group, letters a, b and c are numbers satisfying 0≦

a≦

3, 0≦

b≦

3, 0<

c≦

4, and 0<

a+b+c≦

4,

(II) 1 to 500 parts by weight of an alkoxysilyl-containing organohydrogensiloxane of the following average compositional formula (2);

space="preserve" listing-type="equation">H.sub.d R.sup.4.sub.e (XSiR.sup.5.sub.g (OR.sup.6).sub.h).sub.f SiO.sub.(4-d-e-f)/2 (2)

wherein R⁴ and R¹ each are a substituted or unsubstituted monovalent hydrocarbon group, R⁶ is an unsubstituted or alkoxy-substituted alkyl group, X is a substituted or unsubstituted divalent organic group or oxygen atom, letters d, e and f are numbers satisfying 0<

d≦

2, 0≦

e≦

3, 0<

f≦

3, and 0<

d+e+f≦

4, letter g is equal to 0, 1 or 2, letter h is equal to 1, 2 or 3, and g+h=3, and

(III) 0.1 to 500 parts by weight of an organic titanate.

2. The primer composition of claim 1 wherein the alkoxysilyl-containing organohydrogensiloxane (II) is of the following general formula (3) or (4):

##STR17## wherein R⁷, R⁸, R⁹, R¹⁰, and R¹¹ each are a substituted or unsubstituted monovalent hydrocarbon group, Y is a substituted or unsubstituted divalent organic group, R¹² is an unsubstituted or alkoxy-substituted alkyl group, letters k, m, ml, and r are integers satisfying 0<

k≦

20, 0≦

m≦

20, 1≦

m'"'"'≦

20, and 1≦

r≦

20, letter p is equal to 0, 1 or 2, letter q is equal to 1, 2 or 3, and p+q=3.

4. A composition according to claim 1, wherein R¹ is a C_1-10 -monovalent hydrocarbon group.

5. A composition according to claim 1, wherein R¹ is methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclohexyl, phenyl, tolyl, naphthyl, benzyl or phenylethyl, each optionally substituted by halogen or cyano.

6. A composition according to claim 1, wherein R² is R'"'"'--(Z)_x --, where R¹ is a functional group and Z is an alkylene group of 1 to 10 carbon atoms optionally containing an ether linkage, and x is 0 or 1.

7. A composition according to claim 6, wherein the functional group is a vinyl, allyl, propenyl, butenyl, acryl, methacryl, epoxy, amino, aminoalkyl-substituted amino, mercapto or (x-alkoxycarbony group.

8. A composition according to claim 1, wherein R³ is an optionally alkoxy- substituted C_1-4 -alkyl group.

9. A composition according to claim 8, wherein R³ is methyl, ethyl, propyl, butyl, methoxyemthyl, methoxyethyl, ethoxymethyl or ethoxyethyl.

10. A composition according to claim 1, wherein 0≦

a≦

1, 0≦

b ≦

1, 2≦

c≦

4 and 2≦

a+b+c≦

4.

11. A composition according to claim 1, wherein the organoalkoxysilane (1) is vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β

-methoxyethyoxy)silane, methylvinyldiethoxysilane, allyltrimethoxysilane, γ

-acryloyloxymethyltrimethoxysilane, γ

-methacryloyloxypropyltrimethoxysilane, γ

-glycidyloxypropyltrimethoxysilane, γ

-aminopropyltrimethoxysilane, γ

-aminopropyltriethoxysilane, N-(β

-aminoethyl)-γ

-aminopropyltrimethoxysilane, γ

-mercaptopropyltrimethoxysilane, α

-(ethoxycarbonyl)-ethyltrimethoxysilane, tetramethoxysilane or tetraethoxysilane.

12. A composition according to claim 1, wherein R⁴ and R⁵ are each independently a C_1-10 -monovalent hydrocarbon group.

13. A composition according to claims 1, wherein R⁴ and RW are each independently methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclohexyl, phenyl, tolyl, naphthyl, benzyl or phenylethyl, each optionally substituted by halogen or cyano.

14. A composition according to claim 1, wherein R⁶ is an optionally aLkoxy- substituted C_1-4 -alkyl group.

15. A composition according to claim 1, wherein X is a C_1-10 -divalent organic group or oxygen.

16. A composition according to claim 15, wherein X is a methylene, ethylene, propylene, butylene or phenylene group, optionally substituted by halogen or cyano.

17. A composition according to claim 1, wherein 0≦

d≦

1, 1≦

e≦

2, 0≦

f≦

1,2≦

d+e+f≦

3,g is 0 or 1 and h is2or3.

18. A composition according to claim 2, wherein 0<

m≦

20.

20. A composition according to claim 1, wherein

R¹ is methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclohexyl, phenyl, tolyl, naphthyl, benzyl or phenylethyl, each optionally substituted by halogen or cyano;

R² is R'"'"'--(Z),--, where R¹ is a functional group which is a vinyl, allyl, propenyl, butenyl, acryl, methacryl, epoxy, amino, aminoalkyl-substituted amino, mercapto or α

-alkoxycarbony group; and

Z is an alkylene group of 1 to 10 carbon atoms optionally containing an ether linkage, and x is 0 or 1;

R³ is methyl, ethyl, propyl, butyl, methoxyemthyl, methoxyethyl, ethoxymethyl or ethoxyethyl;

R⁴ and Rs are each independently methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclohexyl, phenyl, tolyl, naphthyl, benzyl or phenylethyl, each optionally substituted by halogen or cyano;

R⁶ is an optionally alkoxy-substituted C_1-4 -alkyl group; and

X is a methylene, ethylene, propylene, butylene or phenylene group, optionally substituted by halogen or cyano.

3. A primer composition comprising

(A) 100 parts by weight of an alkenyl-containing organopolysiloxane of the following average compositional formula (5) having a viscosity of at least 5,000 centistokes at 25°

C.;

space="preserve" listing-type="equation">R.sup.13.sub.i SiO.sub.(4-i)/2 (5)

wherein R¹³ is a substituted or unsubstituted monovalent hydrocarbon group, at least 0.15 mol % of R¹³ is alkenyl, letter i is a positive number satisfying 1.9≦

i≦

2.3,

(B) 5 to 200 parts by weight of an organopolysiloxane of the following average compositional formula (6);

space="preserve" listing-type="equation">R.sup.14.sub.j SiO.sub.(4-j)/2 (6)

wherein R¹⁴ is a substituted or unsubstituted monovalent hydrocarbon group and letter j is a positive number satisfying 0.5≦

j≦

1.8,

(C) 5 to 500 parts by weight of an organoalkoxysilane or siloxane of the following average compositional formula (1);

space="preserve" listing-type="equation">R.sup.1.sub.a R.sup.2.sub.b (OR.sup.3).sub.c SiO.sub.(4-a-b-c)/2 (1)

wherein R¹ is a substituted or unsubstituted monovalent hydrocarbon group, R² is a monovalent organic group having a functional group, R³ is an unsubstituted or alkoxy-substituted alkyl group, letters a, b and c are numbers satisfying 0≦

a≦

3, 0≦

b ≦

3, 0<

c≦

4, and 0<

a+b+c≦

4,

(D) 1 to 500 parts by weight of an organohydrogen- siloxane of the following general formula (3) having an SiH group at a molecular chain end and an alkoxysilyl group in a molecule;

##STR18## wherein R⁷ , R , R⁹, R¹⁰, and R¹¹ each are a substituted or unsubstituted monovalent hydrocarbon group, Y is a substituted or unsubstituted divalent organic group, R¹² is an unsubstituted or alkoxy-substituted alkyl group, letters k and m are integers satisfying 0<

k≦

20 and 0≦

m≦

20, letter E is equal to 0, 1 or 2, letter q is equal to 1, 2 or 3, and p+q=3,

(E) 1 to 100 ppm calculated as platinum metal of a platinum series catalyst,

(F) 0.1 to 100 parts by weight of an organic titanate, and

(G) 0.1 to 5 parts by weight of an organic peroxide.

19. A composition according to claim 3, wherein 0<

m≦

20.