Radiation curable vinyl/silicone release coating

• US 5,527,578 A
• Filed: 09/12/1994
• Issued: 06/18/1996
• Est. Priority Date: 03/20/1991
• Status: Expired due to Term

• Current Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Original Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Inventors: Everaerts, Albert I., Mazurek, Mieczyslaw H., Kantner, Steven S.
• Primary Examiner(s): KILIMAN, LESZEK B
• Application Number:
  US08/304,424
• Time in Patent Office: 645 Days
• Field of Search: 428/40, 428/41, 428/42, 428/343, 428/345, 428/355, 428/446, 428/447, 427/54.3, 427/387, 525/474, 525/477, 525/478, 528/21, 528/22, 528/32, 528/38, 528/41, 528/44
• US Class Current: 428/41.8
• CPC Class Codes: C08F 290/068 Polysiloxanes
• CPC Class Codes: C08L 2666/28 Non-macromolecular organic substances
• CPC Class Codes: C09D 183/08 containing silicon bound to organic groups containing atoms other than carbon, hydrogen, and oxygen
• CPC Class Codes: C09J 2483/005 in the release coating
• CPC Class Codes: C09J 7/401 characterised by the release coating composition
• CPC Class Codes: Y10T 428/1476 Release layer
• 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 428/2852 Adhesive compositions
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane

Abstract

The invention relates to a radiation curable release coating composition comprising:

(a) from about 0.05 to about 25 percent by weight of polymer selected from the group consisting of polymers falling within the general formula: ##STR1## and mixtures thereof, wherein: X are monovalent moieties having ethylenic unsaturation which can be the same or different;

Y are divalent linking groups which can be the same or different;

D are monovalent moieties which can be the same or different selected from the group consisting of hydrogen, an alkyl group of 1 to about 10 carbon atoms, aryl, and substituted aryl;

R are divalent hydrocarbon groups which can be the same or different;

R¹ are monovalent moieties which can be the same or different selected from the group consisting of alkyl, substituted alkyl, aryl, and substituted aryl;

R² are monovalent moieties which can be the same or different selected from the group consisting of alkyl, substituted alkyl, aryl, and substituted aryl;

R³ are monovalent moieties which can be the same or different selected from the group consisting of alkyl, substituted alkyl, vinyl, aryl, and substituted aryl;

R⁴ are monovalent moieties which can be the same or different selected from the group consisting of alkyl, substituted alkyl, vinyl, aryl, and substituted aryl; and

n is an integer of about 25 to about 750;

(b) from about 5 to about 60 percent by weight of one or more free radically polymerizable multifunctional vinyl monomers copolymerizable with said polymer; and

(c) from about 25 to about 95 percent by weight of one or more free radically polymerizable monofunctional vinyl monomers copolymerizable with said polymer;

wherein said weight percentages are based upon the total weight of the radiation curable release coating composition.

The invention also relates to substrates coated with the release coating.

Claims

1. A radiation curable release coating composition comprising:

(a) from about 0.05 to about 25 percent by weight of polymer selected from the group consisting of polymers falling within the general formula;

##STR19## and mixtures thereof, wherein;

X are monovalent moieties having ethylenic unsaturation which can be the same or different;

Y are divalent linking groups which can be the same or different;

D are monovalent moieties which can be the same or different selected from the group consisting of hydrogen, an alkyl group of 1 to about 10 carbon atoms, and aryl;

R are divalent hydrocarbon groups which can be the same or different;

R¹ are monovalent moieties which can be the same or different selected from the group consisting of alkyl and aryl;

R² are monovalent moieties which can be the same or different selected from the group consisting of alkyl and aryl;

R³ are monovalent moieties which can be the same or different selected from the group consisting of alkyl, vinyl, and aryl;

R⁴ are monovalent moieties which can be the same or different selected from the group consisting of alkyl, vinyl, and aryl; and

n is an integer of about 25 to about 750;

(b) from about 5 to about 60 percent by weight of one or more multi-functional free radically polymerizable vinyl monomers copolymerizable with said polymer; and

(c) from about 25 to about 95 percent by weight of one or more monofunctional free radically polymerizable vinyl monomers copolymerizable with said polymer;

wherein said weight percentages are based upon the total weight of said radiation curable release coating composition.

2. The composition of claim 1 wherein X comprises ##STR20## wherein R⁵ is selected from the group consisting of hydrogen and --COOH and R⁶ is selected from the group consisting of hydrogen, methyl, and --CH₂ COOH, n is an integer of about 50 to about 270, R is selected from the group consisting of alkylene of one to about 12 carbon atoms, alkylarylene, and arylene, R¹ and R² are independently selected from the group consisting of alkyl of one to about 12 carbon atoms and aryl, R³ and R⁴ are at least 50% methyl wherein any remaining R³ and R⁴ groups are independently selected from the group consisting of alkyl of about 2 to about 12 carbon atoms, vinyl, and aryl, and D is hydrogen.

3. The composition of claim 1 which further comprises about 0.1 to about 5 weight percent of a free radical initiator based upon the total weight of said radiation curable release coating composition.

4. The composition of claim 1 wherein X comprises ##STR21## Y comprises ##STR22## D═

H;

R comprises --CH₂ CH₂ CH₂ --; and

R¹, R², R³ and R⁴ each comprise --CH₃.

5. The composition of claim 1 wherein X comprises CH₂ ═

CH--;

Y comprises ##STR23## D═

H;

R comprises --CH₂ CH₂ CH₂ --; and

R¹, R², R³ and R⁴ each comprise --CH₃.

6. The composition of claim 1 wherein X comprises CH₂ ═

CH--, Y comprises ##STR24## D═

H, R comprises --CH₂ CH₂ CH₂ --; and

R¹, R², R³ and R⁴ each comprise --CH₃.

7. The composition of claim 1 wherein X comprises ##STR25## Y comprises ##STR26## D═

;

R comprises --CH₂ CH₂ CH₂ --; and

R¹, R², R³ and R⁴ each comprise --CH₃.

8. The composition of claim 1 wherein X comprises ##STR27## Y comprises ##STR28## D═

H;

R comprises --CH₂ CH₂ CH₂ --;

, R¹, R², R³, and R⁴ each comprise --CH₃.

9. The composition of claim 1 wherein said monofunctional free radically polymerizable vinyl monomer is selected from the group consisting of styrene, butyl acrylate, hexyl acrylate, benzyl acrylate, cyclohexyl acrylate, isobornyl acrylate, 2-ethoxyethyl acrylate, isooctyl acrylate, isononyl acrylate, isodecyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, octadecyl acrylate, butyl methacrylate, isobornyl methacrylate, isooctyl methacrylate, tetrahydrofurfuryl acrylate, and mixtures thereof.

10. The composition of claim 1 wherein said monofunctional free radically polymerizable vinyl monomer comprises about 50 to about 100 mole percent acrylic monomer.

11. The composition of claim 1 wherein said monofunctional free radically polymerizable vinyl monomer comprises monomer selected from the group consisting of acrylates of non-tertiary alcohols comprising from about 4 to about 12 carbon atoms.

12. The composition of claim 1 wherein said monofunctional free radically polymerizable vinyl monomer is selected from the group consisting of cyclohexyl acrylate, isobornyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, and mixtures thereof.

13. The composition of claim 1 wherein about 5 to about 15 percent of said monofunctional free radically polymerizable vinyl monomer comprises polar monomer.

14. The composition of claim 1 wherein said multifunctional free radically polymerizable vinyl monomer is selected from the group consisting of divinyl benzene, and acrylates, methacrylates, and beta-acryloxypropionates of 1,6-hexanediol, trimethylolpropane, 1,4-butanediol, triethylene glycol, tetraethylene glycol, pentaerythritol, their ethoxylated and propoxylated analogs, and mixtures thereof.

15. The composition of claim 1 wherein said multifunctional free radically polymerizable monomer is selected from the group consisting of acrylates of 1,6-hexanediol, trimethylolpropane, their ethoxylated and propoxylated analogs, and mixtures thereof.

16. The composition of claim 1 which comprises about 0.2 to about 10 weight percent of said polymer, about 5 to about 35 weight percent of said free radically polymerizable multifunctional vinyl monomer, and from about 55 to about 95 percent by weight of said free radically polymerizable monofunctional vinyl monomer.

17. A sheet coated on at least a portion of at least one major surface thereof with the composition of claim 1.

18. A sheet coated on at least a portion of at least one major surface thereof with the cured composition of claim 1.

19. The composition of claim 1 which further comprises at least one additive selected from the group consisting of flatting agent, pigment, solvent, and conductivity enhancer.

20. The composition of claim 2 wherein n is an integer of about 50 to about 200, R is alkylene of one to about 12 carbon atoms, and R¹, R², R³, and R⁴ are methyl.

21. The composition of claim 3 wherein said free radical initiator is selected from the group consisting of benzoin ethers, benzophenone, derivatives of benzophenone, acetophenone derivatives, camphorquinone, and mixtures thereof.

22. The composition of claim 13 wherein said polar monomer is selected from the group consisting of acrylic acid, N-vinyl pyrrolidone, hydroxyethyl acrylate, methacrylic acid, and mixtures thereof.

23. The composition of claim 16 which comprises about 10 to about 30 weight percent of said free radically polymerizable multifunctional vinyl monomer.

24. The sheet of claim 22 wherein said composition has been coated onto said sheet via an electrospray process prior to curing.