Pressure sensitive adhesive comprising vinylpyrrolidone

• US 6,858,295 B2
• Filed: 12/23/2002
• Issued: 02/22/2005
• Est. Priority Date: 01/22/2002
• Status: Expired due to Fees

• Current Assignee: BASF AG (BASF SE)
• Original Assignee: BASF AG (BASF SE)
• Inventors: Schumacher, Karl-Heinz, Jung, Martin, Diehl, Heiko, Fink, Ralf
• Primary Examiner(s): Nutter, Nathan M.
• Application Number:
  US10/326,391
• Publication Number:
  US 20030153642A1
• Time in Patent Office: 792 Days
• Field of Search: 428/343, 428/355.R, 428/355.EN, 428/355.CN, 156/327, 156/330.9, 156/331.5, 525/217, 525/223
• US Class Current: 428/343
• CPC Class Codes: C08L 2666/10 Homopolymers or copolymers according to C08L39/00 - C08L49/00; Derivatives thereof
• CPC Class Codes: C08L 33/06 of esters containing only carbon, hydrogen and oxygen, which oxygen atoms are present only as part of the carboxyl radical
• CPC Class Codes: C08L 39/06 Homopolymers or copolymers of N-vinyl-pyrrolidones
• 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
• CPC Class Codes: C09J 139/06 Homopolymers or copolymers of N-vinyl-pyrrolidones
• CPC Class Codes: C09J 2203/334 as a label
• 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 428/2852 Adhesive compositions
• CPC Class Codes: Y10T 428/2878 including addition polymer from unsaturated monomer
• CPC Class Codes: Y10T 428/2887 including nitrogen containing polymer [e.g., polyacrylonitrile, polymethacrylonitrile, etc.]

Abstract

A pressure sensitive adhesive comprising a mixture of:

• • a radiation-crosslinkable polymer A) composed of at least 40% by weight of C₁ to C₁₈ alkyl (meth)acrylates, and a polymer B) composed of at least 20% by weight of vinylpyrrolidone and of less than 40% by weight of C₁ to C₁₈ alkyl (meth)acrylates, wherein the fraction of the polymer B) in the mixture is less than 15% by weight, based on the sum of A)+B).

Claims

1. A pressure sensitive adhesive comprising a mixture of:

a radiation-crosslinkable polymer A) composed of at least 40% by weight of C₁ to C₁₈ alkyl (meth)acrylates, and

a polymer B) composed of at least 20% by weight of vinylpyrrolidone and of less than 40% by weight of C₁ to C₁₈ alkyl (meth)acrylates,

wherein the fraction of the polymer B) in the mixture is less than 15% by weight, based on the sum of A)+B).

2. The adhesive as claimed in claim 1, wherein A) is composed of at least 60% by weight of C₁ to C₁₈ alkyl (meth)acrylates.

3. The adhesive as claimed in claim 1, wherein the amount of polymer B) is at least 2% by weight, based on the sum of A)+B).

4. An The adhesive as claimed in claim 1, wherein polymer A) is prepared by emulsion polymerization and is present in the form of an aqueous dispersion.

5. An adhesive as claimed in claim 1, wherein polymer A) is prepared by solution polymerization in an organic solvent.

6. An adhesive as claimed in claim 1, wherein polymers A) and B) have a Fikentscher K value of not more than 80 as determined in a 1% strength solution, in tetrahydrofuran solvent, at 21°

C.

7. An adhesive as claimed in claim 1, comprising a photoinitiator.

8. The adhesive as claimed in claim 7, wherein the photoinitiator is attached to the polymer A).

9. The adhesive as claimed in claim 1, wherein polymer B) is added to the aqueous dispersion of polymer A).

10. The adhesive as claimed in claim 1, wherein polymer B) is added to the organic solution of polymer A) and then the solvent is removed.

11. The adhesive as claimed in claim 1, wherein the amount of water and organic solvents in the adhesive is less than 5 parts by weight per 100 parts by weight of the sum of A) and B).

12. The adhesive as claimed in claim 1, which is a hotmelt adhesive.

13. The adhesive as claimed in claim 1, wherein each of polymer A) and B) is comprised of at least one other monomer selected from the group consisting of vinyl esters of carboxylic acids containing up to 20 carbon atoms, vinylaromatic compounds having up to 20 carbon atoms, ethylenically unsaturated nitriles, vinyl halides, vinyl ethers of alcohols containing from 1 to 10 carbon atoms and 1 or 2 double bonds and mixtures thereof.

14. A method of producing a self-adhesive article, which comprises:

drying the adhesive as claimed in claim 1 as applied to a substrate; and

cross-linking the polymer molecules of the adhesive by exposure to UV light.

15. The method according to claim 14, wherein the self-adhesive article is a label, adhesive tape or film.

16. A self-adhesive article prepared by the method as claimed in claim 14.

17. A self-adhesive article coated with an adhesive as claimed in claim 1.