Acrylic emulsion pressure sensitive adhesive composition including nanometer scale latex particles with monomodal particle size distribution and method of preparing the same

Patent metadata

Field	Value
Publication number	US-9353298-B2
Application number	US-201314413998-A
Country	US
Kind code	B2
Filing date	Oct 8, 2013
Priority date	Oct 9, 2012
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

Disclosed are an acrylic emulsion pressure-sensitive adhesive (PSA) composition and a method of preparing the same. The acrylic emulsion PSA composition with high solid content and high stability includes latex particles in which at least three anionic emulsifiers cover polymer particulates including: a (meth)acrylic acid ester monomer having a C 1 -C 14 alkyl group as a main monomer; at least one monomer selected from the group consisting of a monomer having an allyl ester group, a vinyl ester group, an unsaturated ester group, or a mixture thereof, a cyano group containing monomer, an amine group containing monomer, and a styrenic monomer having a vinyl group, as an auxiliary monomer; a monomer having a carboxyl group and/or a hydroxyl group as a functional monomer; and a crosslinking agent, wherein the latex particles have a nanometer scale average particle diameter and monomodal particle size distribution.

First claim

The invention claimed is:

1. An acrylic emulsion pressure-sensitive adhesive (PSA) composition comprising latex particles in which at least three anionic emulsifiers cover polymer particulates comprising:
a (meth)acrylic acid ester monomer having a C 1 -C 14 alkyl group as a main monomer;
at least one monomer selected from the group consisting of a monomer having an allyl ester group, a vinyl ester group, an unsaturated ester group, or a mixture thereof, a cyano group containing monomer, an amine group containing monomer, and a styrenic monomer having a vinyl group, as an auxiliary monomer;
a monomer having a carboxyl group and/or a hydroxyl group as a functional monomer; and
a crosslinking agent,
wherein the latex particles have a nanometer scale average particle diameter and monomodal particle size distribution.

2. The acrylic emulsion PSA composition according to claim 1 , wherein an agglomerate having a particle diameter of 74 μm or greater is included in an amount of 1000 ppm or less.

3. The acrylic emulsion PSA composition according to claim 1 , wherein the acrylic emulsion PSA composition has a high solid content of 60% or greater.

4. The acrylic emulsion PSA composition according to claim 1 , wherein the acrylic emulsion PSA composition has a viscosity of 500 cps to 1500 cps.

5. The acrylic emulsion PSA composition according to claim 1 , wherein the average particle diameter is 0.1 μm to 0.4 μm.

6. The acrylic emulsion PSA composition according to claim 1 , wherein an amount of the auxiliary monomer is 10 parts by weight to 60 parts by weight based on 100 parts by weight of the main monomer.

7. The acrylic emulsion PSA composition according to claim 1 , wherein an amount of the functional monomer is 1 part by weight to 20 parts by weight based on 100 parts by weight of the main monomer.

8. The acrylic emulsion PSA composition according to claim 1 , wherein an amount of the crosslinking agent is 0.1 parts by weight to 1 part by weight based on 100 parts by weight of the main monomer.

9. The acrylic emulsion PSA composition according to claim 1 , wherein an amount of the at least three anionic emulsifiers is 0.1 parts by weight to 5 parts by weight based on 100 parts by weight of the main monomer.

10. The acrylic emulsion PSA composition according to claim 1 , wherein the (meth)acrylic acid ester monomer having a C 1 -C 14 alkyl group is at least one material selected from the group consisting of methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, isopropyl(meth)acrylate, butyl(meth)acrylate, t-butyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, octyl(meth)acrylate, and lauryl(meth)acrylate.

11. The acrylic emulsion PSA composition according to claim 1 , wherein the group consisting of a monomer having an allyl ester group, a vinyl ester group, an unsaturated ester group, or a mixture thereof, a cyano group containing monomer, an amine group containing monomer, and a styrenic monomer having a vinyl group comprises vinyl acetate, fluorinated nitrile, nitrile chloride, acrylonitrile, methacrylonitrile, acrylamide, styrene, α-methyl styrene, β-methyl styrene, and p-t-butyl styrene.

12. The acrylic emulsion PSA composition according to claim 1 , wherein the monomer having a carboxyl group and/or a hydroxyl group is at least one material selected from the group consisting of maleic anhydride, fumaric acid, crotonic acid, itaconic acid, acrylic acid, methacrylic acid, hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate, hydroxybutyl(meth)acrylate, hydroxyhexyl(meth)acrylate, hydroxyoctyl(meth)acrylate, hydroxylauryl(meth)acrylate, and hydroxypropylglycol(meth)acrylate.

13. The acrylic emulsion PSA composition according to claim 1 , wherein the crosslinking agent is at least one material selected from the group consisting of allylmethacylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, hexanediol ethoxylate diacrylate, ethylene glycol dimethacrylate, hexanediol ethoxylate diacrylate, hexanediol propoxylate diacrylate, neopentyl glycol ethoxylate diacrylate, neopentyl glycol propoxylate diacrylate, trimethylpropane ethoxylate triacrylate, trimethylpropane propoxylate triacrylate, pentaerythritol ethoxylate triacrylate, pentaerythritol propoxylate triacrylate, vinyl trimethoxy silane, and divinyl benzene.

14. The acrylic emulsion PSA composition according to claim 1 , wherein the at least three anionic emulsifiers are selected from the group consisting of carboxylates, phosphates, sulfates, succinates, sulfosuccinates, sulfonates, and disulfonates.

15. The acrylic emulsion PSA composition according to claim 14 , wherein the at least three anionic emulsifiers are selected from the group consisting of sodium alkyl sulfate, sodium polyoxyethylene sulfate, sodium lauryl ether sulfate, sodium polyoxyethylene lauryl ether sulfate, sodium lauryl sulfate, sodium alkyl sulfonate, sodium alkyl ether sulfonate, sodium alkylbenzene sulfonate, sodium linear alkylbenzene sulfonate, sodium alpha-olefin sulfonate, sodium alcohol polyoxyethylene ether sulfonate, sodium dioctyl sulfosuccinate, sodium perfluorooctane sulfonate, sodium perfluorobutane sulfonate, alkyl diphenyloxide disulfonate, sodium dioctyl sulfosuccinate (DOSS), sodium alkyl-aryl phosphate, sodium alkyl ether phosphate, and sodium lauroyl sarcosinate.

16. A protective film formed by coating a surface or opposite surfaces of a film with a water-based PSA including the acrylic emulsion PSA composition according to claim 1 .

17. A method of preparing the acrylic emulsion PSA composition according to claim 1 , the method comprising:
preparing an emulsion comprising at least two anionic emulsifiers and water, separate from a process of preparing a pre-emulsion below;
preparing a pre-emulsion by mixing, with water, a (meth)acrylic acid ester monomer having a C 1 -C 14 alkyl group as a main monomer; at least one monomer selected from the group consisting of a monomer having an allyl ester group, a vinyl ester group, an unsaturated ester group, or a mixture thereof, a cyano group containing monomer, an amine group containing monomer, and a styrenic monomer having a vinyl group, as an auxiliary monomer; a monomer having a carboxyl group and/or a hydroxyl group as a functional monomer; a crosslinking agent; and at least two anionic emulsifiers;
adding a polymerization initiator to the emulsion and continuously adding the pre-emulsion and the polymerization initiator in an equal ratio; and
performing heat polymerization of the resulting emulsion of the adding in the presence of a polymerization initiator.

18. The method according to claim 17 , wherein an amount of the at least two anionic emulsifiers used in the preparing of the emulsion is 0.1 parts by weight to 3 parts by weight based on 100 parts by weight of the main monomer.

19. The method according to claim 18 , wherein an amount of the at least two anionic emulsifiers used in the preparing of the pre-emulsion is 2 parts by weight to 6 parts by weight based on 100 parts by weight of the main monomer.

20. The method according to claim 17 , wherein an amount of the polymerization initiator added to the emulsion is 0.001 parts by weight to 0.02 parts by weight based on 100 parts by weight of the main monomer.

21. The method according to claim 17 , wherein an amount of the polymerization initiator added together with the pre-emulsion is 0.1 parts by weight to 0.5 parts by weight based on 100 parts by weight of the main

Assignees

• Lg Chemical Ltd

Inventors

• Ha Jae Woung
• Kim Young-Min
• Han Jung Sup
• Song Kong Ju
• Kim Mi Young
• Lee Kumhyoung

Classifications

• C09J4/00

  Adhesives based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond {; adhesives, based on monomers of macromolecular compounds of groups C09J183/00 - C09J183/16} · CPC title

• C08L2201/52

  Aqueous emulsion or latex, e.g. containing polymers of a glass transition temperature (Tg) below 20°C · CPC title

• C09J7/0217

  Chemistry & Metallurgy · mapped topic

• C09J9/00

  Adhesives characterised by their physical nature or the effects produced, e.g. glue sticks (C09J7/00 takes precedence) · CPC title

• C09J11/06

  organic · CPC title