Acrylic polyvinyl acetal films and composition

Patent metadata

Field	Value
Publication number	US-10167386-B2
Application number	US-201615175458-A
Country	US
Kind code	B2
Filing date	Jun 7, 2016
Priority date	Dec 8, 2014
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A film is described comprising a (meth)acrylic polymer and a polyvinyl acetal (e.g. butyral) resin. In some embodiments, the film has a glass transition temperature (i.e. Tg) ranging from 30° C. to 60° C. In some embodiments, the film has a gel content of at least 20% or greater. In some embodiments, the film has an elongation at break of at least 175%. The film typically comprises photoinitiator as a result of the method by which the film was made. The film may be a monolithic film or a layer of a multilayer film.

First claim

What is claimed is:

1. A film comprising at least one layer formed from a film composition comprising:
a (meth)acrylic polymer and polyvinyl acetal resin comprising polymerized units having the following formula

wherein R 1 is hydrogen or a C1-C7 alkyl group; and
at least 10 wt-% of polymerized units of monofunctional alkyl (meth)acrylate monomer having a glass transition temperature (Tg) of less than 0° C.;
wherein the film has a single phase and a glass transition temperature (Tg) in the range of 30° C. to 60° C.

2. The film of claim 1 wherein the film composition comprises no greater than 60 wt-% of polymerized units of monofunctional alkyl (meth)acrylate monomer having a Tg of less than 0° C.

3. The film of claim 1 wherein the monofunctional alkyl (meth)acrylate monomer has a Tg of less than −10° C.

4. The film of claim 1 wherein the film composition comprises a bio-based content of at least 10% of the total carbon content.

5. The film of claim 1 wherein the film composition comprises polymerized units of an alkyl (meth)acrylate monomer having an alkyl group with 8 carbon atoms.

6. The film of claim 1 wherein the film composition further comprises up to 35 wt-% of polymerized units of a monofunctional alkyl (meth)acrylate monomer having a Tg greater than 40° C.

7. The film of claim 1 wherein the film composition further comprises at least 10 wt-% and no greater than 65 wt-% of polymerized units of polar monomers.

8. The film of claim 7 wherein the polar monomers are selected from the group consisting of acid-functional, hydroxyl functional monomers, nitrogen-containing monomers, and combinations thereof.

9. The film of claim 1 wherein the film composition comprises polyvinyl butyral.

10. The film of claim 1 wherein the film composition comprises 5 to 30 wt-% of polyvinyl acetal resin.

11. The film of claim 1 wherein the polyvinyl acetal resin has a polyvinyl alcohol content in the range of 10 to 30 wt-%.

12. The film of claim 1 wherein the polyvinyl acetal resin has a glass transition temperature in the range of 60° C. to 75° C.

13. The film of claim 1 wherein the polyvinyl acetal resin has an average molecular weight (Mw) in the range of 20,000 g/mole to 75,000 g/mole.

14. The film of claim 1 wherein the film composition further comprises polymerized units of a multifunctional crosslinker wherein the crosslinker comprises functional groups selected from (meth)acrylate, alkenyl, and hydroxyl-reactive groups.

15. The film of claim 1 wherein the film composition further comprises additives in an amount no greater than 25 wt-%.

16. The film of claim 1 wherein the film composition further comprises a photoinitiator.

17. The film of claim 1 wherein the film composition comprises no greater than 10 wt-% of polymerized units of methacrylate monomers.

18. The film of claim 1 wherein the (meth)acrylic polymer is a random copolymer.

19. The film of claim 1 wherein the film is a monolithic film.

20. The film of claim 1 wherein the film is a film layer of a multilayer film.

21. The film of claim 20 wherein the multilayer film further comprises a second film layer, the second film layer comprising a (meth)acrylic polymer and polyvinyl acetal resin wherein the second film layer has a Tg of less than 30° C.

22. The film of claim 21 wherein the second film layer is heat bondable.

23. The film of claim 1

wherein the film has a gel content of at least 20%.

24. The film of claim 1 wherein the film has an elongation at break of at least 175%.

25. The film of claim 1 wherein the film has a tensile strength as determined by ASTM D-882-10 at a rate of 300 mm/minute in the range of 10 MPa to 50 MPa.

26. The film of claim 1 wherein the film exhibits a 180 degree peel adhesion to glass of 2 oz/inch or less at a 12 inch/minute peel rate.

Assignees

• 3M Innovative Properties Co

Inventors

• Janoski Jonathan E
• Schultz Anthony F
• Lyon Keith R
• Steelman Ronald S
• Lewandowski Kevin M
• Lipscomb Corinne E
• Hobbs Terry R
• Weikel Arlin L
• Seth Jayshree
• Fansler Duane D
• Abe Hidetoshi

Classifications

• C08L29/14 Primary

  Homopolymers or copolymers of acetals or ketals obtained by polymerisation of unsaturated acetals or ketals or by after-treatment of polymers of unsaturated alcohols · CPC title

• C08L33/06 Primary

  of esters containing only carbon, hydrogen and oxygen, which oxygen atoms are present only as part of the carboxyl radical · CPC title

• B32B2307/54

  Yield strength; Tensile strength · CPC title

• B32B2307/31

  Heat sealable · CPC title

• C09D133/08

  Homopolymers or copolymers of acrylic acid esters · CPC title