Water whitening-resistant pressure sensitive adhesives

Patent metadata

Field	Value
Publication number	US-9914858-B2
Application number	US-43725306-A
Country	US
Kind code	B2
Filing date	May 19, 2006
Priority date	May 20, 2005
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

Water resistant, acrylic emulsion pressure sensitive adhesive polymers containing particles having a mean “volume-average” particle diameter of greater than about 210 nm for use in label and tape application are provided. The emulsion polymers exhibit an increase in opacity of less than about 10%.

First claim

What is claimed is:

1. A water resistant acrylic pressure sensitive adhesive polymer formed by polymerizing in emulsion a mixture of monomers comprising
at least one alkyl acrylate ester of an alcohol containing 4 to 8 carbon atoms in the alkyl chain;
at least one polar monomer; and
at least one copolymerizable monomer,
wherein the pressure sensitive adhesive polymer as an emulsion polymer has a volume average particle diameter of at least 300 nm as determined by laser light scattering and wherein the pressure sensitive adhesive polymer, when coated and dried to a thickness of up to 1 mil on a clear 2 mil biaxially oriented polypropylene (BOPP) facestock or backing and immersed in water of at least 66° C. for 60 minutes, and then laminated to a clear polyester film of up to 2 mil thickness, exhibits an increase in opacity of less than about 10% as determined with a spectrocolorimeter.

2. The water resistant acrylic polymer of claim 1 wherein the polar monomer comprises a carboxyl group-containing monomer, a hydroxyl group-containing monomer or combinations thereof.

3. The water resistant acrylic polymer of claim 1 wherein the polar monomer comprises a carboxylic acid containing 3 to 5 carbon atoms.

4. The water resistant acrylic polymer of claim 1 wherein the polar monomer is chosen from acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid and combinations of two or more thereof.

5. The water resistant acrylic polymer of claim 1 wherein the polar monomer is chosen from beta-carboxyethyl acrylate, monomethacryloylethyl succinate, monomethacryloylethyl phthalate, polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate and combinations or two or more thereof.

6. The water resistant acrylic polymer of claim 1 wherein the alkyl acrylate ester of an alcohol comprises 2-ethylhexyl acrylate.

7. The water resistant acrylic polymer of claim 1 wherein the copolymerizable monomer comprises at least one styrene or styrene derivative monomer.

8. The water resistant acrylic polymer of claim 7 further comprising methyl methacrylate comonomer.

9. The water resistant acrylic polymer of claim 7 wherein the styrene or styrene derivative is chosen from styrene, tertiary butyl styrene, dimethyl styrene, vinyl toluene and combinations of two or more thereof.

10. The water resistant acrylic polymer of claim 1 wherein the copolymerizable monomer is chosen from methyl methacrylate, ethyl acrylate, methyl acrylate, vinyl acetate and combinations of two or more thereof.

11. The water resistant acrylic polymer of claim 10 wherein the chain transfer agent comprises n-dodecyl mercaptan.

12. The water resistant acrylic polymer of claim 1 wherein polymerization is carried out in the presence of at least one nonionic surfactant.

13. The water resistant acrylic polymer of claim 1 wherein polymerization is carried out in the presence of at least one anionic surfactant.

14. The water resistant acrylic polymer of claim 12 wherein polymerization is further carried out in the presence of at least one anionic surfactant, wherein the weight ratio of nonionic surfactant to anionic surfactant is about 1.5:1 to about 4:1.

15. The water resistant acrylic polymer of claim 12 wherein the nonionic surfactant is chosen from modified fatty alcohol or acid ethoxylate, alkyl phenol ethoxylate, polyoxyethylene alkyl phenol ether, polyoxyethylene alkyl ether, and combinations of two or more thereof.

16. The water resistant acrylic polymer of claim 13 wherein the anionic surfactant is chosen from salts of sulfated nonyl or octyl phenoxy poly(ethyleneoxy) ethanols, alkyl sulfonate, alkyl sulfosuccinate, polyoxyethylene alkyl sulfate, polyoxyethylene alkylaryl sulfate, polyoxyethylene alkyl phenol ether sulfate and combinations of two or more thereof.

17. The water resistant acrylic polymer of claim 1 wherein the solids content of the emulsion is at least about 55% by weight.

18. The water resistant acrylic polymer of claim 1 wherein the solids content of the emulsion is about 55% to about 70% by weight.

19. The water resistant acrylic polymer of claim 1 wherein the polymer is formed in the presence of at least one water soluble initiator.

20. The water resistant acrylic polymer of claim 19 wherein the initiator is chosen from ammonium persulfate, potassium persulfate, sodium persulfate, azo initiators and combinations of two or more thereof.

21. The water resistant acrylic polymer of claim 7 wherein the mixture of monomers further comprises at least one monomer chosen from methyl methacrylate, ethyl acrylate, methyl acrylate, vinyl acetate and combinations of two or more thereof.

22. The water resistant acrylic polymer of claim 1 wherein the polymer exhibits an opacity increase of less than about 3% as determined by the Hot Water Resistance Test.

23. A water resistant acrylic pressure sensitive adhesive polymer formed by polymerizing in emulsion a mixture of monomers comprising
about 55% to about 98% by weight based on the total weight of monomers of at least one alkyl acrylate ester of an alcohol containing 4 to 8 carbon atoms in the alkyl chain;
about 0.5% to about 5% by weight based on the total weight of monomers of at least one polar monomer; and
about 1% to about 25% by weight based on the total weight of monomers of at least one styrene or styrene derivative copolymerizable monomer,
wherein the pressure sensitive adhesive polymer as an emulsion polymer has a volume average particle diameter of at least 300 nm as determined by laser light scattering and wherein the pressure sensitive adhesive polymer, when coated and dried to a thickness of up to 1 mil on a clear 2 mil biaxially oriented polypropylene (BOPP) facestock or backing and immersed in water of at least 66° C. for 60 minutes, and then laminated to a clear polyester film of up to 2 mil thickness, exhibits an opacity increase of less than about 10% as determined with a spectrocolorimeter.

24. A water resistant acrylic pressure sensitive adhesive polymer formed by polymerizing in emulsion a mixture of monomers comprising
about 50% to about 99% by weight based on the total weight of monomers of at least one alkyl acrylate ester of an alcohol containing 4 to 8 carbon atoms in the alkyl chain;
about 0.5% to about 3% by weight based on the total weight of monomers of at least one polar monomer;
about 5% to about 50% by weight based on the total weight of monomers of at least one copolymerizable monomer selected from methyl methacrylate, ethyl acrylate, methyl acrylate, vinyl acetate, and combinations of two or more thereof,
about 0.01% to about 0.5% by weight of a chain transfer agent;
wherein the pressure sensitive adhesive polymer as an emulsion polymer has a volume average particle diameter of at least 300 nm as determined by laser light scattering and wherein the pressure sensitive adhesive polymer, when coated and dried to a thickness of up to 1 rail on a clear 2 mil biaxially oriented polypropylene (BOPP) facestock or backing and immersed in water of at least 66° C. for 60 minutes, and then laminated to a clear polyester film of up to 2 mil thickness, exhibits an opacity increase of less than about 10% as determined with a spectrocolorimeter.

25. A water resistant acrylic pressure sensitive adhesive polymer formed by polymerizing in emulsion a mix

Assignees

• Bartholomew Eric L
• Lester Christopher L
• Maerki Roger
• Mueller Alfredo
• Yeadon Graham
• Avery Dennison Corp

Inventors

• Bartholomew Eric L
• Lester Christopher L
• Maerki Roger
• Mueller Alfredo
• Yeadon Graham

Classifications

• C09J2203/334

  as a label · CPC title

• C09J133/06 Primary

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

• C08F220/18

  with acrylic or methacrylic acids · CPC title

• Y10T428/31935

  Ester, halide or nitrile of addition polymer · CPC title

• C09J7/0217

  Chemistry & Metallurgy · mapped topic