Method for Preparing Adhesive Acrylic Ester Polymer Syrup

• US 20070299226A1
• Filed: 06/01/2006
• Published: 12/27/2007
• Est. Priority Date: 06/01/2005
• Status: Abandoned Application

• Current Assignee: LG Chem Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Choi, Sun-hyuk, Park, Jong-suh, Choi, Jung-Uk
• Application Number:
  US11/666,280
• Publication Number:
  US 20070299226A1
• Time in Patent Office: Days
• US Class Current: 526/218.1
• CPC Class Codes: C08F 2/02 Polymerisation in bulk
• CPC Class Codes: C09J 133/06 of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical

Abstract

The present invention relates to a method for preparing an acrylic ester polymer syrup by bulk polymerization, and more particularly, to a method for preparing an acrylic ester polymer syrup, which comprises the steps of: supplying a monomer solution and an initiator solution to a monomer solution reservoir and an initiator solution reservoir, respectively; supplying the monomer solution and the initiator solution to a complete-mixing type continuous reactor, while maintaining the dissolved oxygen in the monomer solution reservoir and the initiator solution reservoir at 0.0001 to 3 ppm, separately or after mixing prior to the supply; and performing bulk polymerization continuously while maintaining the solution mixture supplied to the continuous reactor at 70 to 150 ° C. and 1 to 10 atm, with a mean residence time of 30 to 240 minutes. In accordance with the present invention, an acrylic ester polymer syrup can be obtained with a degree of polymerization of 20 to 70% at a low polymerization temperature, even with a small amount of initiator. Productivity can be improved by reducing reaction time with the use of an initiator having a short half-life and polymerization can be performed very stably and continuously without gelation.

Claims

1. A method for preparing an acrylic ester polymer syrup using a polymerization apparatus comprising a complete-mixing type continuous reactor, a monomer solution reservoir, and an initiator solution reservoir, which comprises the steps of:

a) supplying a monomer solution and an initiator solution to the monomer solution reservoir and the initiator solution reservoir, respectively;

b) supplying the monomer solution and the initiator solution to the complete-mixing type continuous reactor, while maintaining the dissolved oxygen in the monomer solution reservoir and the initiator solution reservoir at 0.0001 to 3 ppm, separately or after mixing prior to the supply; and

c) performing bulk polymerization continuously while maintaining the solution mixture supplied to the continuous reactor at 70 to 150°

C. and 1 to 10 atm, with a mean residence time of 30 to 240 minutes.

2. The method for preparing an acrylic ester polymer syrup as set forth in claim 1, wherein the monomer solution comprises i) an acrylic ester monomer and ii) a molecular weight controller, and the initiator solution comprises i) an acrylic ester monomer, ii) a molecular weight controller and iii) an initiator having a ten hour half life temperature of 40 to 135°

C.

3. The method for preparing an acrylic ester polymer syrup as set forth in claim 2, wherein the acrylic ester monomer of i) is at least one acrylic ester monomer having a C₁-C₁₂ alkyl group selected from the group consisting of methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate, hexyl(meth)acrylate, isooctyl(meth)acrylate, 2-ethylhexyl(meth)acrylate and isononyl(meth)acrylate.

4. The method for preparing an acrylic ester polymer syrup as set forth in claim 2, wherein the acrylic ester monomer of i) is mixed with a polar acrylic monomer copolymerizable with the acrylic ester monomer.

5. The method for preparing an acrylic ester polymer syrup as set forth in claim 4, wherein the polar acrylic monomer is at least one polar acrylic monomer selected from the group consisting of:

a carboxyl-containing monomer such as (meth)acrylate, maleate and fumarate;

a hydroxy-containing monomer such as hydroxy(meth)acrylate and hydroxy(meth)methylacrylate; and

a nitrogen-containing monomer such as acrylimicle, N-vinylpyrrolidone and N-vinylcaprolactam, and the amount used is 1 to 20 parts by weight per 100 parts by weight of the acrylic ester monomer.

6. The method for preparing an acrylic ester polymer syrup as set forth in claim 2, wherein an unsaturated monomer such as styrene and benzoyl(meth)acrylate is further added to the acrylic ester monomer of i).

7. The method for preparing an acrylic ester polymer syrup as set forth in claim 2, wherein the molecular weight controller of ii) is at least one mercaptan-based chain transfer agent having a thiol (—

SH) group.

8. The method for preparing an acrylic ester polymer syrup as set forth in claim 2, wherein the amount of molecular weight controller of ii) is 0.0001 to 5 wt % per 100 wt % of the total monomers.

9. The method for preparing an acrylic ester polymer syrup as set forth in claim 2, wherein the initiator of iii) is at least one azo-based or peroxide-based initiator having a ten hour half-life temperature of 40 to 135°

C.

10. The method for preparing an acrylic ester polymer syrup as set forth in claim 2, wherein the amount of initiator of iii) is 0.00001 to 1 wt % per 100 wt % of the total monomers.

11. The method for preparing an acrylic ester polymer syrup as set forth in claim 1, wherein the acrylic ester polymer syrup has a final degree of polymerization of 20 to 70%.

12. An adhesive comprising an acrylic ester polymer syrup prepared by the method as set forth in claim 1.