Pressure-sensitive adhesive composition

1. An adhesive composition comprising:

a) 60 parts by weight or greater of a low T g (meth)acrylate solute copolymer component having a T g of <20° C. comprising

i. C 1 -C 18 (meth)acrylic acid ester monomer units;

ii. acid functional ethylenically unsaturated monomer units;

iii. optionally non-acid functional, ethylenically unsaturated polar monomer units;

iv. optionally vinyl monomer units; and

v. optionally a multifunctional (meth)acrylate, and

b) 5 to 40 parts by weight of a high T g (meth)acrylate copolymer having a M w ≧30 k and a T g of >50° C. comprising:

i. high T g (meth)acrylic acid ester monomer units;

ii) optional acid functional ethylenically unsaturated monomer units;

iii) optional low T g (meth)acrylic acid ester monomer units;

iv) optional non-acid functional, ethylenically unsaturated polar monomer units;

v) optional vinyl monomer units;

the sum of a) and b) being 100 parts by weight; and

c) 0.1 to 20 parts be weight of a hydrogenated hydrocarbon tackifier, based on 100 parts by weight of a), and b);

wherein the tackifier is incompatible with a), and b).

2. The adhesive composition of claim 1 wherein the low T g (meth)acrylate copolymer component comprises syrup copolymer comprising a solute low T g copolymer in solvent monomer(s).

3. The adhesive composition of claim 2 wherein the low T g solute copolymer comprises:

i. 85 to 99.5 parts by weight of an (meth)acrylic acid ester;

ii. 0.5 to 15 parts by weight of an acid functional ethylenically unsaturated monomer;

iii. 0 to 10 parts by weight of a non-acid functional, ethylenically unsaturated polar monomer;

iv. 0 to 5 parts vinyl monomer; and

v. 0 to 5 parts of a multifunctional (meth)acrylate;

based on 100 parts by weight total monomer.

4. The adhesive composition of claim 2 wherein the syrup copolymer comprises up to 30 parts by weight of the solute copolymer in solvent monomers.

5. The adhesive composition of claim 2 wherein the syrup copolymer a) has a viscosity of from 500 to 10,000 cPs at 22° C.

6. The adhesive composition of claim 2 , wherein the a solvent monomer comprises a mixture of:

i) an alkyl (meth)acrylate monomer;

ii) an optional acid-functional ethylenically unsaturated monomer;

iii) an optional non-acid functional polar monomer;

iv) an optional vinyl monomer, and

v) an optional multifunctional (meth)acrylate.

7. The adhesive composition of claim 1 , wherein the low T g (meth)acrylate copolymer component a) comprises solution copolymer comprising a solute low T g copolymer in a solvent.

8. The adhesive composition of claim 1 , wherein the high T g monomer is selected from t-butyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, s-butyl methacrylate, t-butyl methacrylate, stearyl methacrylate, phenyl methacrylate, cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate, benzyl methacrylate, 3,3,5 trimethylcyclohexyl acrylate, cyclohexyl acrylate, N-octyl acrylamide, and propyl methacrylate or combinations thereof.

9. The adhesive composition of claim 1 further comprising d) a crosslinking agent.

10. The adhesive composition of claim 1 wherein the crosslinking agent is a triazine crosslinking agent.

11. The adhesive composition of claim 1 , wherein the (meth)acrylic acid ester monomer units of said low T g copolymer comprises acrylic esters of 2-octanol, citronellol, or dihydrocitronellol.

12. The adhesive composition of claim 1 , wherein the (meth)acrylic acid ester monomer units of said low T g copolymer comprises acrylic esters of 2-alkyl alkanols.

13. The adhesive composition of claim 1 , comprising1 to 15 parts by weight of the hydrogenated hydrocarbon tackifer, relative to 100 parts of the low- and high- T g (co)polymer components.

14. The adhesive composition of claim 1 , comprising 2 to 10 parts by weight of the hydrogenated hydrocarbon tackifer, relative to 100 parts of the low- and high- T g (co)polymer components.

15. An adhesive article comprising a substrate and a coating of the adhesive of claim 1 on a surface thereof.

16. The adhesive article of claim 15 wherein the substrate is a low surface energy substrate.

17. The adhesive composition of claim 1 wherein the low T g solute copolymer comprises:

ia. 65 to 98.5 parts by weight of an (meth)acrylic acid ester monomer;

ib. 1 to 20 parts by weight of high T g (meth)acrylic acid ester monomers;

ii. 0.5 to 15 parts by weight of an acid-functional ethylenically unsaturated monomer;

iii. 0 to 10 parts by weight of a non-acid functional, ethylenically unsaturated polar monomer;

iv. 0 to 5 parts vinyl monomer; and

v. 0 to 5 parts of a multifunctional (meth)acrylate;

based on 100 parts by weight total monomers of the low T g copolymer.