Adhesion promoters for thiolene adhesive formulations

• US 5,028,661 A
• Filed: 11/27/1989
• Issued: 07/02/1991
• Est. Priority Date: 10/14/1986
• Status: Expired due to Fees

• Current Assignee: Loctite Corporation (Henkel AG & Co KGaA)
• Original Assignee: Loctite Corporation (Henkel AG & Co KGaA)
• Inventors: Jacobine, Anthony F., Glaser, David M., Clark, Paul J.
• Primary Examiner(s): Marquis, Melvyn J.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/443,046
• Time in Patent Office: 582 Days
• Field of Search: 528/364, 528/376, 528/26, 528/190, 528/192, 528/360, 525/189, 525/479, 525/535
• US Class Current: 525/189
• CPC Class Codes: C08G 75/045 from mercapto compounds and unsaturated compounds
• CPC Class Codes: C08G 75/12 Polythioether-ethers C08G75/0245 takes precedence

Abstract

Compounds useful as adhesion promoters for thermally cured thiolene adhesives include a) acrylic or norbornene acid phosphate esters such as ##STR1## b) maleic, acrylic, methacrylic, norbornene dicarboxylic, and fumaric acids and half acid esters and peresters of maleic fumaric and norbornene dicarboxylic acids; and c) norbornene, acrylic or methacrylic silanes having two or three hydrolyzable groups bound to the silicon atom thereof, such as 5-(triacetoxysilyl) norbornene.

The adhesion promoters may be employed as surface primers for conventional thiolene compositions. Alternatively the thiolene compositions themselves may be modified by addition of 0.1 to 10% by weight of the adhesion promoter. Preferred thiolene compositions employ norbornene functional ene ingredients.

Claims

1. In a thiolene composition curable free radically under thermal conditions, the composition comprising a base formulation including a polythiol resin and a polyene resin, the improvement wherein the composition further includes an adhesion promoter compound selected from the group consisting of norbornene acid phosphate esters;

;

norbornene functional silanes having two or three hydrolyzable groups bound to the silicon atom thereof;

maleic, nobornene dicarboxylic and fumaric acids;

half peresters of maleic, fumaric and norbornene dicarboxylic acids; and

half esters of maleic, fumaric and norbornene dicarboxylic acids, in an amount effective to promote adhesion of the cured composition relative to the base composition without said adhesion promoter compound.

2. A composition as in claim 1 wherein the said adhesion promoter comprises a surface primer which has diffused into said thiolene composition after said primer and thiolene compositions have been successively applied to a substrate upon which the substrate is to be cured.

3. A composition as in claim 1 wherein the said adhesion promoter is a component uniformly mixed into said thiolene composition prior to application thereof to a substrate on which the composition is to be cured.

4. A composition as in claim 1 wherein the adhesion promoter compound is selected from the group consisting of:

a) norbornene acid phosphate esters;

b) maleic, norbornene dicarboxylic and fumaric acids and half esters of maleic, fumaric and norbornene dicarboxylic acids; and

c) norbornene functional silanes having two or three hydrolyzable groups bound to the silicon atom thereof, and the composition further includes an effective amount of a free radical initiator selected from the group consisting of peroxy compounds, azonitrile compounds and benzopinacol.

5. A composition as in claim 1 wherein the adhesion promoter is selected from the group consisting of maleic acid, fumaric acid, and norbornene dicarboxylic acid and half esters and half peresters of said acids.

6. A composition as in claim 1 wherein the adhesion promoter is a norbornene acid phosphate ester.

7. A composition as in claim 1 wherein the adhesion promoter is a norbornene functional silane.

8. A composition as in claim 7 wherein the adhesion promoter is 5-(triacetoxysilyl)norbornene.

10. A composition as in claim 6 wherein the adhesion promoter is selected from mono and bis 5-norbornenecarboxyethylphosphate;

mono and bis 5-norbornenecarboxyhexylphosphate; and

5-norbornenemethylphosphate.

11. A composition as in claim 1 wherein the polyene includes a plurality of norbornene groups.

13. A composition as in claim 1 wherein the adhesion promoter is present in an amount of between 0.1% and 10%.

14. A composition as in claim 1 wherein the adhesion promoter is present in an amount of between 0.5% and 5%.

15. A composition as in claim 11 wherein the polyene has the formula:

##STR11## where Q'"'"' is CR⁵, O, S, NR⁵ or SO₂, R⁵ is H or alkyl, n'"'"' is 1-6, and x and y are integers of one or more.

16. A composition as in claim 11 wherein the polythiol is an ester of a polyol and an α

or β

-mercaptocarboxylic acid.

9. A thiolene composition curable free radically under thermal conditions comprising (a) a polythiol resin, (b) a polyene resin having the formula:

space="preserve" listing-type="equation">[A]--(X).sub.n

where A is an n-valent organic or polyorganosiloxane residue, n is an integer of at least 2, and X is a group selected from the class consisting of;

##STR10## f is an integer from 1 to 9;

R is a radical selected from the group consisting of hydrogen, fluorine, chlorine, furyl, thienyl, pyridyl, phenyl and substituted phenyl, benzyl and substituted benzyl, alkyl and substituted alkyl, alkoxy and substituted alkoxy, and cycloalkyl and substituted cycloalkyl, the substituents on the substituted members being selected from the group consisting of nitro, chloro, fluoro, acetoxy, acetamide, phenyl, benzyl, alkyl, alkoxy and cycloalkyl alkyl and alkoxy groups having from one to nine carbon atoms and cycloalkyl groups having from three to eight carbon atoms, at least one of R¹, R², and R³ is a member of the group consisting of vinyl, 1-propenyl and isopropenyl and the remaining R¹, R², and R³ groups are selected from H, lower alkyl and alkoxy, R⁴ is alkyl, R⁵ is H or alkyl, p is 0 or 1, R⁶ is H or alkyl O is CR⁶₂, O, S, NR⁶ or SO₂ and q is an integer from 0 to 10, and (c) an effective amount of an adhesion promoter compound wherein the adhesion promoter compound is a maleic acid monoperester.

12. In a thiolene composition curable free radically under thermal conditions, the composition comprising a base formulation including a polythiol resin and a polyene resin, the improvement wherein the composition further includes an adhesion promoter compound selected from the group consisting of maleic, norbornene dicarboxylic and fumaric acids, half peresters of maleic, fumaric and norbornene dicarboxylic acids, and hydrocarbyl or hydrocarbylether half esters of maleic, fumaric and norbornene dicarboxylic acids in an amount effective to promote adhesion of the cured composition relative to the base composition without said adhesion promoter compound.