Acrylamido functional disubstituted acetyl aryl ketone photoinitiators

• US 5,506,279 A
• Filed: 05/03/1994
• Issued: 04/09/1996
• Est. Priority Date: 10/13/1993
• Status: Expired due to Term

• Current Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Original Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Inventors: Heilmann, Steven M., Bennett, Greggory S., Chen, Kejian, Winslow, Louis E., Babu, Gaddam N., Smith, Howell K. II
• Primary Examiner(s): CHAPMAN, MARK A
• Application Number:
  US08/237,399
• Time in Patent Office: 707 Days
• Field of Search: 522/34, 522/35, 522/36, 522/904, 560/40, 560/221
• US Class Current: 522/34
• CPC Class Codes: C07C 233/49 having the carbon atom of the carboxamide group bound to a carbon atom of an acyclic unsaturated carbon skeleton
• CPC Class Codes: C07C 233/52 with the substituted hydrocarbon radical bound to the nitrogen atom of the carboxamide group by a carbon atom of a ring other than a six-membered aromatic ring
• CPC Class Codes: C07C 237/22 having nitrogen atoms of amino groups bound to the carbon skeleton of the acid part, further acylated peptides C07K
• CPC Class Codes: C07C 2601/08 the ring being saturated
• CPC Class Codes: C07C 327/28 having sulfur atoms of esterified thiocarboxyl groups bound to carbon atoms of hydrocarbon radicals substituted by singly-bound oxygen atoms
• CPC Class Codes: C07D 295/108 to an acyclic saturated chain
• CPC Class Codes: C08F 2/50 with sensitising agents
• CPC Class Codes: C08F 20/58 containing oxygen in addition to the carbonamido oxygen , e.g. N-methylolacrylamide, N-acryloylmorpholine
• CPC Class Codes: Y10S 522/904 Monomer or polymer contains initiating group

Abstract

The invention provides novel acrylamide functional disubstituted acetyl aryl ketones and a process for their preparation in high yields uncontaminated by difunctional material. The invention further provides photocrosslinkable compositions comprising one or more ethylenically-unsaturated monomers and as photoinitiator the acrylamide functional disubstituted acetyl aryl ketone of the invention. The compositions are useful for the preparation of films and coatings, particularly pressure-sensitive adhesive coatings.

Claims

1. The acrylamide functional disubstituted acetyl aryl ketone compound having the formula:

##STR17## wherein R¹ is hydrogen or methyl;

R² and R³ independently are an alkyl group of 1 to 14 carbon atoms, a cycioalkyl group of 3 to 14 carbon atoms, an aryl group of 5 to 12 ring atoms, an arenyl group having 6 to 16 carbon atoms, the aryl and arenyl groups up to 3 heteroatoms selected from S, N, and nonperoxidic O, or R² and R³ taken together with the carbon atom to which they are joined form a carbocyclic ring of 4 to 12 ring atoms;

W is -O-, -S-, or -NH- or a divalent connecting group joining the carbonyl group of the acrylamidoacetyl functional group to the photosensitive group, P; and

P is a radiation sensitive aryl ketone group capable of Norrish Type I cleavage, said compound being a photoinitiator.

2. The acrylamide functional disubstituted acetyl aryl ketone according to claim 1 wherein W is selected from the class of connecting groups consisting of ##STR18## in which n is a number having a value of one to four, R⁴ is hydrogen or methyl group, X is -O-, -S-, or -NH-, and Y is selected from the group consisting of ##STR19##

3. The acrylamide functional disubstituted acetyl aryl ketone according to claim 1 wherein the radiation sensitive group P has the formula:

##STR20## in which Ar is an arylene group having 6 to 12 carbon atoms that can be substituted by a lower alkyl group having one to six carbon atoms; and

R⁵ is selected from the group consisting of hydrogen, C₁ to C₁₂ alkyl groups, C₁ to C₁₂ alkoxy groups, and phenyl groups;

each R⁶, R⁷, and R⁸ independently are selected from the group consisting of hydroxyl, C₁ to C₁₂ alkyl groups, C₁ to C₁₂ alkoxy groups, di(C₁ to C₁₂) amino groups, and phenyl groups, provided that at least one of R⁶, R⁷ and R⁸ is selected from the group consisting of hydroxyl, C₁ to C₁₂ alkoxy groups, or C₁ to C₁₂ amino groups, or that any two of R⁶, R⁷, R⁸ together is an alkylene group, -(C_p H_2p)-, or an alkylene-dioxy group, -O-(C_p H_2p)-O-, in which p is an integer having a value of two or three, that together with the carbon atoms to which they are attached form a 5- or 6- membered ring, or any two of R⁶, R⁷, and R⁸ taken together with the carbon atom to which they are attached form a carbonyl group, ##STR21## provided that the remaining R⁶, R⁷, or R⁸ is selected from the group consisting of hydroxyl, C₁ to C₁₂ alkoxy groups, C₁ to C₂ amino groups, and aryl groups.

4. The acrylamide functional disubstituted acetyl aryl ketone of claim 3 wherein Ar is selected from the group consisting of phenylene, naphthylenylene, and biphenylene.

5. The acrylamide functional disubstituted acetyl aryl ketone according to claim 1 having at least one of the formulae:

##STR22##

6. A photopolymerizable composition comprising one or more ethylenically-unsaturated monomers and an acrylamide functional disubstituted acetyl aryl ketone photoinitiator according to claim 1.

7. A composition photopolymerizable to a pressure-sensitive adhesive comprising per 100 parts by weight (pbw) of

(1) 60 to 99.95 pbw of one or more acrylic acid esters of monohydric aliphatic alcohols, said alcohols having an average of 4 to 12 carbon atoms;

(2) 0 to 39.95 pbW Of ethylenically-unsaturated monomers whose homopolymer has a glass transition temperature (Tg) greater than 50°

C., and

(3) 0.01 to 10.0 pbw of acrylamide functional disubstituted acetyl aryl ketone photoinitiator as defined in claim 2,

(4) 0 to 5.0 pbw of a polyfunctional acrylate monomer, and

(5) 0 to 5.0 pbw of a thermal or actinic radiation activated source of free radicals, the source being free of ethylenic unsaturation.

8. The composition according to claim 7 wherein said polyfunctional acrylate is hexanediol diacrylate.

9. The composition according to claim 7 wherein said copolymerizable polyunsaturated monomer is present in an amount in the range of 0.01 to 5.0 pbw.

10. The composition according to claim 7 wherein said acrylamide functional disubstituted acetyl aryl photoinitiator is present in an amount in the range of 0.01 to 2.0 weight percent.

11. The polymerized composition according to claim 7.

12. The composition according to claim 11 which has been polymerized using actinic radiation having intensities in the range of 0.1 to 150 mW/cm².

13. A substrate bearing a layer of the polymerized composition according to claim 11.

14. A substrate bearing a layer of the photopolymerizable adhesive composition of claim 7.

15. A process for preparing an acrylamide functional disubstituted acetyl aryl ketone comprising the steps of

(a) providing an admixture of 100 mole percent of a hydroxyl, thiol, or amine functional aryl ketone with from 50 to 150 mole percent of one or more disubstituted alkenyl azlactones;

(b) maintaining the admixture at 0°

C. to 100°

C. for a sufficient time to convert the hydroxyl, thiol, or amine functional aryl ketone to an acrylamide functional disubstituted acetyl aryl ketone as defined in claim 2;

(c) optionally, isolating the resulting acrylamide functional disubstituted acetyl aryl ketone which is a photoinitiator.

16. The process of claim 15 wherein the hydroxy, thiol, or amine functional aryl ketone has the formula H-W-P, wherein W and P are as defined above and the alkenyl azlactone has the formula ##STR23## wherein R¹, R², and R³ are defined above.

17. The process of claim 15, wherein P is ##STR24## wherein R⁶, R⁷, and R⁸ are defined above, and wherein R⁵ is a lower alkyl group of 1 to 6 carbon atoms.

18. The process according to claim 15 further comprising the step of polymerizing said acrylamide functional disubstituted acetyl aryl ketone with at least one ethylenically unsaturated monomer to provide a crosslinked polymer.

19. A pressure sensitive adhesive tape comprising a flexible backing and on at least one surface thereof a layer of the photopolymerized composition according to claim 11.

20. The pressure sensitive adhesive tape according to claim 19 further comprising a layer of a release coating.

21. A roll of tape comprising the pressure sensitive adhesive tape according to claim 20.

22. A laminated article comprising the pressure-sensitive adhesive according to claim 11 applied between two substrates.

23. The laminated article according to claim 22 wherein at least one substrate is nonadherent to the pressure sensitive adhesive.

24. A polymeric photoinitiator comprising units having the formula ##STR25## in which R¹, R², R³, W, and P are the same as defined above;

R⁹ is one or more groups as determined by the identity of the ethylenically-unsaturated monomers in the polymerizable composition; and

a and b are each numbers having a value sufficient to provide to the linear polymer a number average molecular weight of from about 1000 to 5,000,000, the mole ratio, b/(a+b), having a value from about 0.0001 to 0.5.

25. A photopolymerizable composition comprising one or more ethylenically unsaturated monomers and the polymeric photoinitiator having units according to claim 24.

26. The photopolymerizable composition according to claim 25 which is a coatable syrup.

27. A pressure sensitive adhesive composition comprising the polymerized composition according to claim 25.

28. A pressure sensitive adhesive tape comprising a flexible backing and on at least one surface thereof the pressure sensitive adhesive composition according to claim 27.

29. A laminated article comprising the pressure-sensitive adhesive tape according to claim 27 applied to a substrate.

30. A process for preparing the polymeric photoinitiator according to claim 24 comprising the steps of:

a) polymerizing an alkenyl azlactone with a copolymerizable ethylenically unsaturated monomer, and

b) reacting the resulting copolymer with a hydroxy, thiol, or amino group-substituted photoinitiator to yield said polymeric photoinitiator.