Block-copolymer containing crosslinkable photoinitator groups

Patent metadata

Field	Value
Publication number	US-9670295-B2
Application number	US-201313796771-A
Country	US
Kind code	B2
Filing date	Mar 12, 2013
Priority date	Mar 18, 2011
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

A block-copolymer containing at least two different blocks wherein block A contains (meth)acrylate monomers the copolymer having a glass transition temperature of less than 15° C., block B contains (meth)acrylate monomers the copolymer having a glass transition temperature of more than 25° C. being free of thio-containing substances in the polymer chain, characterized in that one block contains at least one photoinitiator chemically bound to the chain.

First claim

What is claimed is:

1. A block-copolymer containing at least two different blocks wherein block A contains (meth)acrylate monomers and has a glass transition temperature of less than 15° C., block B contains (meth)acrylate monomers and has a glass transition temperature of more than 25° C., which is free from thio-compounds in the polymer chain, one block containing at least one photoinitiator covalently bonded to the chain and block B comprises 4 wt % to 13 wt % tert-butyl (methyl)-acrylate by weight of block-copolymer.

2. A block-copolymer according to claim 1 , wherein the photoinitiator contains a benzoylphenoxy-group or an acetophenone group and further contains a (meth)acrylate group.

3. A block-copolymer according to claim 1 , wherein 1 to 10 photoinitiator groups are contained per polymer chain.

4. A block-copolymer according to claim 1 , wherein the photoinitiator is covalently bonded in block A.

5. A block-copolymer according to claim 1 , wherein the block-copolymer has a molecular weight (MN) of 20000 to 300000 g/mol.

6. A block-copolymer according to claim 1 , wherein block A comprises 98 to 70 wt.-% of the total molecular weight or comprises 70 to 25 wt-% block A.

7. A block-copolymer according to claim 1 , wherein block A and/or block B contains further monomers polymerizable by ATRP, which monomers do not belong to the group of (meth)acrylates and are selected from vinyl ethers, vinyl esters, fumaric acid esters, styrene and its derivatives, and acrylonitrile.

8. A block-copolymer according to claim 1 , wherein one block comprises olefinic, epoxy, OH—, COOH—, phosphate-, phosphonate-, and/or sulfonate groups.

9. A block-copolymer according to claim 1 , wherein the polymer contains up to five blocks, as an AB, ABA or BAB block polymer.

10. A pressure sensitive adhesive containing at least one polymer according to claim 1 , wherein the adhesive is a hot melt adhesive having a viscosity from 10000 mPas to 450000 mPas at 130° C.

11. A pressure sensitive adhesive containing at least one polymer according to claim 1 , wherein the adhesive is a solvent borne adhesive having a viscosity from 200 mPas to 5000 mPas at 25° C.

12. A pressure sensitive adhesive according to claim 10 , wherein the adhesive further comprises at least one of a tackifier, stabilizer, antioxidant, solvent, plasticizer, or radiation reactive compounds.

13. An article comprising a substrate having a layer of the adhesive of claim 10 thereon, wherein the adhesive is present in an amount of 5 to 50 mg/m2.

14. A pressure sensitive adhesive according to claim 13 , wherein the adhesive is crosslinked by electron beam or ultraviolet radiation.

15. The block copolymer of claim 1 manufactured by ATRP.

16. The block copolymer of claim 1 comprising about 8% to about 13% by weight of tert-butyl (methyl)-acrylate.

17. The block copolymer of claim 1 wherein block A comprises ethylhexylacrylate, butylacrylate, methylacrylate and combinations thereof.

18. A block-copolymer containing at least two different blocks wherein block A contains (meth)acrylate monomers and has a glass transition temperature of less than 15° C.; block B is prepared from a mixture of monomers consisting of tert butyl (meth)acrylate and methyl methacarylate and has a glass transition temperature of more than 25° C.; wherein the block-copolymer is free from thio-compounds in the polymer chain and one block contains at least one photoinitiator covalently bonded to the chain.

19. The block-copolymer of claim 18 , wherein block A is prepared from a mixture of monomers consisting of ethyhexylacrylate, n-butylacrylate and methacrylate.

20. The block-copolymer of claim 18 , wherein block A is prepared from a mixture of monomers consisting of 33 wt % to 37 wt % ethyhexylacrylate, 33 wt % to 37 wt % n-butylacrylate and 12 wt % to 14 wt % methacrylate and block B is prepared from a mixture of monomers consisting of 33 wt % to 37 wt % tert butyl (meth)acrylate and 7 wt % to 9 wt % methyl methacarylate.

Assignees

• Henkel Ag & Co Kgaa
• Evonik Roehm Gmbh
• Evonik Roehm Gmbh

Inventors

• Palasz Peter D
• Xenidou Maria
• Van Wijk Kerstin
• Krause Simon
• Hilf Stefan

Classifications

• C09J7/387

  Block-copolymers · CPC title

• C08F2438/01

  Atom Transfer Radical Polymerization [ATRP] or reverse ATRP · CPC title

• C08F22/10 Primary

  Esters · CPC title

• C09J153/00

  Adhesives based on block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Adhesives based on derivatives of such polymers · CPC title

• C09J133/08

  Homopolymers or copolymers of acrylic acid esters · CPC title