Adhesives having improved chemical resistance and curable silicone compositions for preparing the adhesives

1. A method comprising:

(1) applying a composition to a substrate, and

(2) curing the composition;

where the composition is prepared by mixing components comprising

(I) a polyorganosiloxane having an average of at least two unsaturated organic groups per molecule,

where component (I) is free of fluorine atoms;

(II) an organohydrogenpolysiloxane having an average of at least two silicon-bonded hydrogen atoms per molecule,

where component (II) is free of fluorine atoms;

(III) a hydrosilylation catalyst;

(IV) a fluoroorganosilicone having at least one functional group reactive with component (I), component (II), or both;

(V) an unsaturated ester-functional compound comprising

v) a combination thereof; where

in formula i), each R 18 is independently a hydrogen atom, a monovalent hydrocarbon group of 1 to 4 carbon atoms, or CF 3 ,

each R 19 is independently a divalent organic group of 1 to 20 carbon atoms,

each R 20 is independently a hydrogen atom or a monovalent hydrocarbon group of 1 to 20 carbon atoms,

in formula ii), n has an average value of 0 to 2 and m=4−n,

each R 21 is independently a hydroxyl group, or CF 3 ,

each R 22 is independently a hydrogen atom, a monovalent hydrocarbon group of 1 to 4 carbon atoms, or CF 3 ,

each R 23 is independently a hydrogen atom or a monovalent hydrocarbon group of 1 to 20 carbon atoms,

in formula iii), each R 24 is independently a fluoroalkyl group, an epoxy functional group, or a polyether group,

each R 25 is independently anoxygen-bridged monovalent organic group or a carbon-bridged carbonyl group,

with the proviso that at least one of R 24 or R 25 is unsaturated,

in formula iv), each R 26 is independently a monovalent organic group or a hydrogen atom, with the proviso that at least one R 26 is an aliphatically unsaturated monovalent organic group or a hydrogen atom, and

each R 27 is independently an oxygen atom or a divalent organic group; and

(VI) an adhesion promoter.

2. The method of claim 1 , where the substrate comprises an epoxy, a polycarbonate, a poly(butylene terephthalate) resin, a polyamide resin, a blend of polyamide resin with syndiotactic polystyrene, an acrylonitrile-butadiene-styrene, a styrene-modified poly(phenylene oxide), a poly(phenylene sulfide), a vinyl ester, a polyphthalamide, a polyimide, silicon, aluminum, a stainless steel alloy, titanium, copper, nickel, silver, gold, or combinations thereof.

3. The method of claim 1 , where the substrate comprises a metal.

4. The method of claim 1 , where component (I) comprises a polyorganosiloxane of the formula:

(a) R 1 3 SiO(R 1 2 SiO) α (R 1 R 2 SiO) β SiR 1 3 ,

(b) R 3 2 R 4 SiO(R 3 2 SiO) χ (R 3 R 4 SiO) δ SiR 3 2 R 4 , or

(c) a combination thereof, where

α has an average value of 0 to 2000,

β has an average value of 2 to 2000,

each R 1 is independently a monovalent organic group,

each R 2 is independently an unsaturated monovalent organic group,

χ has an average value of 0 to 2000,

δ has an average value of 0 to 2000,

each R 3 is independently a monovalent organic group, and

each R 4 is independently an unsaturated monovalent organic group.

5. The method of claim 1 , where component (I) comprises an MQ resin consisting essentially of R 5 3 SiO 1/2 units and SiO 4/2 units, a TD resin consisting essentially of R 5 SiO 3/2 units and R 5 2 SiO 2/2 units, an MT resin consisting essentially of R 5 3 SiO 1/2 units and R 5 SiO 3/2 units, an MTD resin consisting essentially of R 5 3 SiO 1/2 units, R 5 SiO 3/2 units, and R 5 2 SiO 2/2 units, or a combination thereof, where

each R 5 is a monovalent organic group of 1 to 20 carbon atoms, and

the resin contains an average of 3 to 30 mole percent of unsaturated organic groups.

6. The method of claim 1 , where component (II) comprises siloxane units selected from HR 6 2 SiO 1/2 , R 6 3 SiO 1/2 , HR 6 SiO 2/2 , R 6 2 SiO 2/2 , R 6 SiO 3/2 , SiO 4/2 , or combinations thereof; where each R 6 is independently selected from monovalent organic groups free of aliphatic unsaturation.

7. The method of claim 1 , where component (II) comprises a compound of the formula:

(a) R 7 3 SiO(R 7 2 SiO) ε (R 7 HSiO) φ SiR 7 3 , or

(b) R 8 2 HSiO(R 8 2 SiO) γ (R 8 HSiO) η SiR 8 2 H,

(c) a combination thereof, where

ε has an average value of 0 to 2000,

φ has an average value of 2 to 2000,

each R 7 is independently a monovalent organic group free of aliphatic unsaturation,

γ has an average value of 0 to 2000,

η has an average value of 0 to 2000, and

each R 8 is independently a monovalent organic group free of aliphatic unsaturation.

8. The method of claim 1 , where component (III) comprises a platinum metal, a rhodium metal, or an organometallic compound.

9. The method of claim 1 , where component (IV) comprises a compound of the formula:

(a) R 9 3 SiO(R 9 2 SiO) τ (R 9 R 10 SiO) φ SiR 9 3 ,

(b) R 11 2 R 12 SiO(R 11 2 SiO) κ (R 11 R 12 SiO) λ SiR 11 2 R 12 ,

(c) F 3 C(CF 2 ) ν R 13 —Si—[O—Si(R 14 ) 2 (R 15 )] 3 ,

(d) a resinous or branched structure consisting essentially of R 15 R 14 2 SiO 1/2 units, CF 3 (CF 2 ) ν R 13 SiO 3/2 units, and optionally SiO 4/2 units, or

(e) a combination thereof; where

ξ has an average value of 0 to 2000,

φ has an average value of 1 to 500,

each R 9 is independently a hydrogen atom or a monovalent organic group, with the proviso that at least one R 9 is a hydrogen atom or an unsaturated monovalent organic group;

each R 10 is independently a fluoro-functional organic group;

κ has an average value of 0 to 2000;

λ has an average value of 0 to 500;

each R 11 is independently a hydrogen atom or a monovalent organic group, with the proviso that at least one R 11 is a hydrogen atom or an unsaturated monovalent organic group;

each R 12 is independently a fluoro-functional organic group;

each R 13 is independently a divalent organic group;

each R 14 is independently a monovalent hydrocarbon group free of aliphatic unsaturation;

ν is 0 to 10; and

each R 15 is independently a hydrogen atom or an unsaturated monovalent organic group.

10. The method of claim 1 , where component (VI) comprises a transition metal chelate, an alkoxysilane, a combination of an alkoxysilane and a hydroxy-functional polyorganosiloxane, or a combination thereof.

11. The method of claim 1 , where component (VI) comprises an unsaturated alkoxysilane, an epoxy-functional alkoxysilane, an epoxy-functional siloxane, or a combination thereof.

12. The method of claim 1 , where component (VI) comprises an alkoxysilane of the formula R 28 μ Si(OR 29 ) (4-μ) , where

μ is 1, 2, or 3,

each R 28 is independently a monovalent organic group, with the proviso that at least one R 28 is an unsaturated organic group or an epoxy-functional group, and

each R 29 is independently an unsubstituted, saturated hydrocarbon group of at least 1 carbon atom.

13. The method of claim 1 , where the composition further comprises (VII) a void reducing agent, (VIII) a pigment, (IX) a filler, (X) a cure modifier, (XI) a rheology modifier, (XII) a spacer, an acid acceptor, an anti-oxidant, a stabilizer, a flame retardant, a flow control additive, a reactive diluent, an anti-settling agent, a silylating agent, a desiccant, a blowing agent, or a combination thereof.

14. The method of claim 1 , where the composition has SiH tot /Vi tot of 1.05 to 5.0.

15. The method of claim 1 , where the method forms a product selected from die attach adhesives, as lid seals, gels and encapsulants.

16. The method of claim 1 , where the composition is applied to more than one substrate in step (1).