Multi-block copolymer

Patent metadata

Field	Value
Publication number	US-9315697-B2
Application number	US-201414478430-A
Country	US
Kind code	B2
Filing date	Sep 5, 2014
Priority date	May 2, 2013
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

Provided are a multi-block copolymer, a pressure-sensitive adhesive composition, a method of preparing a multi-block copolymer, a pressure-sensitive adhesive polarizing plate, and a liquid crystal display device. The pressure-sensitive adhesive composition including the multi-block copolymer may have excellent durability regardless of a temperature and/or humidity. In addition, the method of preparing a multi-block copolymer may prepare a multi-block copolymer increased in molecular weight which is structurally controlled with a simple process using a compound containing at least two halogen atoms. Accordingly, when included in a pressure-sensitive adhesive resin, the multi-block copolymer may have excellent cohesive strength in the resin, and a network structure during curing, and thus, when applied to a pressure-sensitive adhesive composition, the multi-block copolymer may be usefully applied to an optical member due to excellent durability regardless of a temperature and humidity.

First claim

What is claimed is:

1. A multi-block copolymer, comprising:
a first block having a glass transition temperature of −10° C. or less;
a second block having a glass transition temperature of 50° C. or more; and
a third block having a glass transition temperature of −10° C. or less,
wherein the multi-block copolymer is a tri-block copolymer in which the first and third blocks are coupled at both ends of the second block,
wherein a crosslinkable functional group is present in the first or third block, and
wherein the first or third block comprises a polymerized unit of 90 to 99.9 parts by weight of an acrylic acid ester monomer and 0.1 to 10 parts by weight of a copolymerizable monomer having the crosslinkable functional group.

2. The multi-block copolymer of claim 1 , wherein the crosslinkable functional groups are comprised in the first and third blocks.

3. The multi-block copolymer of claim 1 , wherein the crosslinkable functional group comprised in the first or third block is at least one selected from the group consisting of a hydroxyl group, a carboxyl group, an isocyanate group and a glycidyl group.

4. The multi-block copolymer of claim 1 , which has a number average molecular weight (Mn) of 160,000 or more.

5. A pressure-sensitive adhesive composition, comprising:
the multi-block copolymer of claim 1 .

6. The pressure-sensitive adhesive composition of claim 5 , further comprising:
a crosslinking agent having at least two functional groups capable of reacting with a crosslinkable functional group.

7. A method of preparing the multi-block copolymer of claim 1 , comprising:
polymerizing a polymerizable monomer in the presence of a catalyst, a ligand capable of coordinate-binding with the catalyst, and an initiator having at least two bonds of Formula 3 in a structure:
C—X  [Formula 3]

where C is a carbon atom, X is selected from the group consisting of a halogen atom, CN, SR 1 , N 3 , S—C(═S)R 2 , and S—C(═S)N(R 3 ) 2 , in which R 1 to R 3 are each independently CN, an aryl having 6 to 20 carbon atoms, an alkyl having 1 to 20 carbon atoms, or an alkylthio having 1 to 20 carbon atoms, and in the case of an N(R 3 ) 2 group, a 5- or 6-membered heterocyclic ring is formed by coupling two R 3 groups, In addition, the R 1 to R 3 may be substituted with at least one halogen.

8. The method of claim 7 , wherein the catalyst is a compound represented by Formula 5:
M n+ X n   [Formula 5]

where M n+ is selected from the group consisting of Cu +1 , Cu +2 , Fe +2 , Fe +3 , Ru +2 , Ru +3 , Cr +2 , Cr +3 , Mo +2 , Mo +3 , W +2 , W +3 , Mn +3 , Mn +4 , Rh +3 , Rh +4 , Re +2 , Re +3 , Co + , Co +2 , V +2 , V +3 , Zn + , Zn +2 , Au + , Au +2 , Ag + and Ag +2 , X is a halogen atom, and n is an integer of 1 to 4 as a formal charge of a metal.

9. The method of claim 8 , wherein the catalyst is Cu(II)Cl 2 , Cu(II)Br 2 , Cu(II)I 2 or a mixture thereof.

10. The method of claim 7 , wherein the catalyst is comprised at 0.001 to 1 part by weight, relative to 100 parts by weight of the polymerizable monomer.

11. The method of claim 7 , wherein the ligand is a ligand having at least one nitrogen, oxygen, phosphorous, or sulfur atom that is coordinated with a catalyst through a σ-bond; or a ligand containing at least two carbon atoms that is coordinated with a catalyst through a π-bond.

12. The method of claim 7 , wherein the initiator having at least two bonds of Formula 3 in the structure is a compound having at least two units represented by Formula 6:
—O—C(O)—(R 13 R 14 )C—X  [Formula 6]

where R 13 and R 14 are hydrogen or an alkyl having 1 to 4 carbon atoms, and X is a halogen atom.

13. The method of claim 7 , wherein the initiator having at least two bonds of Formula 3 in the structure is a compound represented by Formula 7:
X—C(R 13 R 14 )—C(O)—O—Y—O—(O)C—(R 15 R 16 )C—Z  [Formula 7]

where R 13 to R 16 are each independently hydrogen or an alkyl having 1 to 8 carbon atoms, X and Z are each independently a halogen atom, and Y is an alkylene having 1 to 8 carbon atoms.

14. The method of claim 12 , wherein the initiator is ethylene bis(2-bromoisobutyrate), 1,1,1-tris(2-bromoisobutyryloxymethyl)ethane, pentaerythritol tetrakis(2-bromoisobutyrate), dipentaerythritol hexakis(2-bromoisobutyrate), or a mixture thereof.

15. The method of claim 7 , wherein the initiator is comprised at 0.01 to 5 parts by weight, relative to 100 parts by weight of the polymerizable monomer.

16. The method of claim 7 , wherein the polymerizing of the polymerizable monomer comprises:
preparing a macroinitiator by polymerizing a polymerizable monomer in the presence of an initiator, a catalyst, a ligand, and a reducing agent; and
preparing a multi-block copolymer by polymerizing a polymerizable monomer in the presence of the macroinitiator, the catalyst, the ligand, and the reducing agent.

17. The method of claim 16 , wherein the reducing agent is an organic reducing agent or an inorganic reducing agent.

18. A pressure-sensitive adhesive polarizing plate, comprising:
a polarizer; and
a pressure-sensitive adhesive layer present on one or both surfaces of the polarizer, and formed from the pressure-sensitive adhesive composition of claim 5 .

19. A liquid crystal display device, comprising:
the pressure-sensitive adhesive polarizing plate of claim 18 attached to one or both surfaces of a liquid crystal panel.

20. The method of claim 13 , wherein the initiator is ethylene bis(2-bromoisobutyrate), 1,1,1-tris(2-bromoisobutyryloxymethyl)ethane, pentaerythritol tetrakis(2-bromoisobutyrate), dipentaerythritol hexakis(2-bromoisobutyrate), or a mixture thereof.

Assignees

• Lg Chemical Ltd

Inventors

• Kim Su Jeong
• Yoon Jeong Ae
• Lee Min Ki
• Chi Han Na
• Kim No Ma
• Yoon Sung Soo

Classifications

• C09J153/00 Primary

  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

• C09J133/06

  of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical · CPC title

• C08F4/10

  of alkaline earth metals, zinc, cadmium, mercury, copper or silver · CPC title

• C08F299/0464

  Metals or metal containing compounds · CPC title

• G02B5/30

  Polarising elements (light-modulating devices with active elements G02F1/00) · CPC title