Radiation activated addition reaction

• US 4,530,879 A
• Filed: 03/04/1983
• Issued: 07/23/1985
• Est. Priority Date: 03/04/1983
• Status: Expired due to Term

• Current Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Original Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Inventors: Drahnak, Timothy J.
• Primary Examiner(s): Robinson, Ellis P.
• Application Number:
  US06/472,158
• Time in Patent Office: 872 Days
• Field of Search: 528/15, 528/31, 528/32, 526/279, 526/171, 204/159.13, 204/158 R, 204/162 R, 428/447, 428/40-42, 428/352, 428/343, 428/345, 428/354
• US Class Current: 428/352
• CPC Class Codes: C08G 77/38 Polysiloxanes modified by chemical after-treatment C08G77/045 takes precedence
• CPC Class Codes: C08K 5/56 Organo-metallic compounds, i.e. organic compounds containing a metal-to-carbon bond
• CPC Class Codes: C08L 83/04 Polysiloxanes
• CPC Class Codes: Y10T 428/28 Web or sheet containing structurally defined element or component and having an adhesive outermost layer
• CPC Class Codes: Y10T 428/2809 including irradiated or wave energy treated component
• CPC Class Codes: Y10T 428/2839 with release or antistick coating
• CPC Class Codes: Y10T 428/2848 Three or more layers
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane

Abstract

A process for the addition of compounds containing silicon-bonded hydrogen to compounds containing aliphatic unsaturation. The process is activated by actinic radiation and is conducted in the presence of a platinum complex having an ultraviolet displaceable group.

Claims

1. In a hydrosilation process which comprises reacting a composition comprising a compound having aliphatic unsaturation and a compound containing at least one silicon-bonded hydrogen atom and not having more than two hydrogen atoms attached to any one silicon atom, in the presence of a platinum catalyst, the improvement which comprises using as the platinum catalyst, a (η

-diolefin)(σ

-aryl) platinum complex having an ultraviolet displaceable group.

2. The process of claim 1 wherein said reaction is carried out by means of exposing said composition to actinic radiation.

3. The process of claim 2 wherein the platinum complex is represented by the formula:

##STR12## wherein R¹ is an alkadiene that is π

-bonded to platinum, the alkadiene having a straight or branched chain or a cyclic ring, the alkadiene further being unsubstituted or substituted by one or more groups that are inert in a hydrosilation reaction;

R² and R³ are aryl radicals that are σ

-bonded to platinum and are independently selected from monocyclic and polycyclic aryl radicals, said aryl radicals being unsubstituted or substituted by one or more radicals that are inert in a hydrosilation reaction;

R⁴ and R⁵ are independently hydrogen or an ortho-alkenyl radical, said alkenyl radical being in a straight or branched chain or in a 5- or 6-membered ring, the unsaturated bond of the alkenyl radical being in the 2- or 3-position with respect to the σ

-bonded position;

a is zero or one, being zero only when both R⁴ and R⁵ are ortho-alkenyl radicals, and one when either R⁴ or R⁵ is not an ortho-alkenyl radical.

4. The process of claim 3 wherein the platinum complex is selected from the group consisting of

(η

⁴ -1,5-COD)-bis(4-methoxyphenyl)platinum

(η

⁴ -1,5-COD)-bis-(4-trimethylsilylphenyl)platinum

(η

⁴ -1,5-COD)-bis(4-trifluoromethylphenyl)platinum

(η

⁴ -1,5-COD)-bis(3-trifluoromethylphenyl)platinum

(η

⁴ -1,5-COD)-bis(2-trifluoromethylphenyl)platinum

(η

⁴ -1,5-COD)-bis(2,4,6-trifluorophenyl)platinum.

5. The process of claim 1 wherein the composition comprises from 0.1 to 10.0 equivalent weights of the compound having silicon-bonded hydrogen per equivalent weight of the compound having aliphatic unsaturation, and, per 1,000,000 parts by weight of the total composition, from 5 to 1000 parts by weight of the platinum catalyst.

6. The process of claim 1 wherein the compound containing aliphatic unsaturation is a polyorganosiloxane having the general formula:

##STR13## wherein each R⁸ is independently an unhalogenated or halogenated ethylenically-unsaturated radical, an unhalogenated or halogenated alkyl radical or cycloalkyl radical, or a phenyl radical, at least 90% of all R⁸ radicals being methyl radicals, but no more than 10% of all R⁸ radicals being vinyl or propenyl, and at least two of the R⁸ radicals being vinyl or propenyl,

h is a number having a value from about 75 to 250 such that the polyorganovinylsiloxane has a viscosity from about 0.3 to 3 pascal-seconds (300 to 3000 centipoise) at 25°

C., and

g is 0,1,2, or 3.

7. The process of claim 1 wherein the compound containing silicon-bonded hydrogen is a polyorganohydrosiloxane having the general formula:

##STR14## wherein each R¹⁰ is independently an alkyl radical, a cycloalkyl radical, a phenyl radical, a hydroxyalkyl radical, a (polyalkoxy)alkyl radical, or hydrogen, at least two but no more than 50% of all R¹⁰ groups being hydrogen,

m is 0, 1, 2 or 3, and

n is a number having an average value from one to 275 such that when considered with the value of provides a molecular weight to the polyorganohydrosiloxane of between 134 and 20,000.

8. The process of claim 7 wherein the composition comprises from 1 to 40 parts by weight of the polyorganohydrosiloxane, from 60 to 99 parts by weight of the compound having aliphatic unsaturation, and, per 1,000,000 parts by weight of the total composition, from 5 to 1000 parts by weight of the platinum complex.

9. The process of claim 1 wherein the compound having aliphatic unsaturation is one having olefinic unsaturation.

10. A composition which comprises

(a) a silicon compound containing at least one hydrogen atom attached to silicon per molecule, there being not more than two hydrogen atoms attached to any one silicon atom,

(b) a compound containing aliphatic unsaturation, and

(c) a (η

-diolefin)(σ

-aryl)platinum complex having an ultraviolet displaceable group.

11. The composition of claim 10 wherein the platinum complex is represented by the formula:

##STR15## wherein R¹ is an alkadiene that is π

-bonded to platinum, the alkadiene being a straight or branched chain or a cyclic ring, the alkadiene further being unsubstituted or substituted by one or more groups that are inert in a hydrosilation reaction;

R² and R³ are aryl radicals that are σ

-bonded to platinum and are independently selected from monocyclic and polycyclic aryl radicals said aryl radicals being unsubstituted or substituted by one or more radicals that are inert in a hydrosilation reaction;

R⁴ and R⁵ are independently hydrogen or an ortho-alkenyl radical, said alkenyl radical being in a straight or branched chain or in a ring, the unsaturated bond of the alkenyl radical being in the 2- or 3-position with respect to the σ

-bonded position;

a is zero or one, being zero only when both R⁴ and R⁵ are ortho-alkenyl radicals, and one when either R⁴ or R⁵ is not an ortho-alkenyl radical.

12. The composition of claim 11 wherein the platinum complex is selected from the group consisting of

(η

⁴ -1,5-COD)-bis(4-methoxyphenyl)platinum

(η

⁴ -1,5-COD)-bis(4-trimethylsilylphenyl)platinum

(η

⁴ -1,5-COD)-bis(4-trifluoromethylphenyl)platinum

(η

⁴ -1,5-COD)-bis(3-trifluoromethylphenyl)platinum

(η

⁴ -1,5-COD)-bis(2-trifluoromethylphenyl)platinum

(η

⁴ -1,5-COD)-bis(2,4,6-trifluorophenyl)platinum.

13. The composition of claim 10, said composition comprising from 0.1 to 10.0 equivalent weights of the compound having silicon-bonded hydrogen per equivalent weight of the compound having aliphatic unsaturation, and, per 1,000,000 parts by weight of the total composition, from 5 to 1000 parts by weight of the platinum complex.

14. Radiation curable composition comprising

(a) polyorganohydrosiloxane having the general formula:

##STR16## wherein each R¹⁰ is independently an alkyl radical, a cycloalkyl radical, a phenyl radical, a hydroxyalkyl radical, a (polyalkoxy)alkyl radical or hydrogen, at least two but no more than 50% of all R¹⁰ groups being hydrogen;

m is 0, 1, 2 or 3, and

n is a number having an average value from one to 275 such that when considered with the value of m provides a molecular weight to the polyorganohydrosiloxane of between 134 and 20,000, (b) a polyorganosiloxane having the general formula;

##STR17## wherein each R⁸ is independently an unhalogenated or halogenated ethylenically unsaturated radical;

an unhalogenated or halogenated alkyl radical or cycloalkyl radical, or the phenyl radical, at least 90% of all R⁸ radicals being methyl radicals, but no more than 10% of all R⁸ radicals being vinyl or propenyl, and at least two of the R⁸ radicals being vinyl or propenyl,

h is a number having a value from about 75 to 250 such that the polyorganovinylsiloxane has a viscosity from about 0.3 to 3 pascal-seconds (300 to 3000 centipoise) at 25°

C., and

g is 0,1,2, or 3,

(c) a platinum complex represented by the formula;

##STR18## wherein R¹ is an alkadiene that is π

-bonded to platinum, the alkadiene being a straight or branched chain or a cyclic ring, the alkadiene further being unsubstituted or substituted by one or more groups that are inert in a hydrosilation reaction;

R² and R³ are aryl radicals that are σ

-bonded to platinum and are independently selected from monocyclic and polycyclic aryl radicals, said aryl radicals being unsubstituted or substituted by one or more radicals that are inert in a hydrosilation reaction;

R⁴ and R⁵ are independently hydrogen or an ortho-alkenyl radical, said alkenyl radical being in a straight or branched chain or in a ring, the unsaturated bond of the alkenyl radical being in the 2- or 3-position with respect to the σ

-bonded position;

a is zero or one, being zero only when both R⁴ and R⁵ are ortho-alkenyl radicals, and one when either R⁴ or R⁵ is not an ortho-alkenyl radical.

15. The composition of claim 14, said composition comprising from 60 to 99 parts by weight of the polyorganosiloxane, from about 1 to about 40 parts by weight of the polyorganohydrosiloxane, and, per 1,000,000 parts by weight of the total composition, from 5 to 1000 parts by weight of the platinum complex.

16. The composition of claim 14 wherein the platinum complex is selected from the group consisting of

(η

⁴ -1,5-COD)-bis(4-methoxyphenyl)platinum

(η

⁴ -1,5-COD)-bis(4-trimethylsilylphenyl)platinum

(η

⁴ -1,5-COD)-bis(4-trifluoromethylphenyl)platinum

(η

⁴ -1,5-COD)-bis(3-trifluoromethylphenyl)platinum

(η

⁴ -1,5-COD)-bis(2-trifluoromethylphenyl)platinum

(η

⁴ -1,5-COD)-bis(2,4,6-trifluorophenyl)platinum.

17. A substrate bearing on at least one major surface a layer prepared by applying the composition of claim 14 to said surface and then exposing said composition to actinic radiation.

18. Sheet material provided with a release surface prepared by applying on at least one side of said sheet material the composition of claim 14 and then exposing said composition to actinic radiation, and a layer of normally tacky and pressure-sensitive adhesive bonded firmly to the other side of said sheet material, thereby forming a pressure-sensitive adhesive tape.