Radical curable adhesive composition, and polarizing plate and optical member comprising same

1. A radical-curable adhesive composition comprising:

a (A) radical-polymerizable compound having at least one hydrophilic functional group in the molecule;

a (B) phosphate-based compound having three (meth)acrylic groups in the molecule; and

a (C) radical initiator,

wherein the (B) phosphate-based compound is a compound represented by Chemical Formula I:

wherein R 1 , R 2 and R 3 are each independently a substituted or unsubstituted C 1-10 alkylene group, a substituted or unsubstituted C 4-14 cycloalkylene group, a substituted or unsubstituted C 6-14 arylene group or a combination thereof; R 4 , R 5 and R 6 are each independently hydrogen or a methyl group; and X 1 , X 2 and X 3 are each independently oxygen (O) or nitrogen (N).

2. The radical-curable adhesive composition of claim 1 , comprising:

the (A) radical-polymerizable compound in 40 to 93 parts by weight;

the (B) phosphate-based compound in 1 to 40 parts by weight; and

the (C) radical initiator in 0.5 to 20 parts by weight, with respect to 100 parts by weight of the radical-curable adhesive composition.

3. The radical-curable adhesive composition of claim 1 , wherein the (A) radical-polymerizable compound is a mixture of a (a-1) radical-polymerizable first compound including at least one hydroxyl group and at least one (meth)acrylic group in the molecule; and a (a-2) radical-polymerizable second compound including at least two hydroxyl groups, at least one benzene ring or cyclohexane ring, and at least two (meth)acrylic groups in the molecule.

4. The radical-curable adhesive composition of claim 3 , wherein the (a-1) first compound is one or more types selected from the group consisting of the following [Chemical Formula 1] to [Chemical Formula 21]:

5. The radical-curable adhesive composition of claim 3 , wherein the (a-2) second compound is one or more types selected from the group consisting of the following [Chemical Formula 22] to [Chemical Formula 24]:

6. The radical-curable adhesive composition of claim 1 , further comprising a (D) phosphate-based compound having one or two (meth)acrylic groups in the molecule.

7. The radical-curable adhesive composition of claim 6 , wherein the (D) a phosphate-based compound is included in 5 to 40 parts by weight with respect to 100 parts by weight of the radical-curable adhesive composition.

8. The radical-curable adhesive composition of claim 6 , wherein the (D) phosphate-based compound is one or more types selected from the group consisting of the following [Chemical Formula II] and [Chemical Formula III]:

wherein, in [Chemical Formula II], R 7 and R 8 are each independently a substituted or unsubstituted C 1-10 alkylene group, a substituted or unsubstituted C 4-14 cycloalkylene group, a substituted or unsubstituted C 6-14 arylene group or a combination thereof; R 9 and R 10 are each independently hydrogen or a methyl group; and X 4 and X 5 are each independently oxygen (O) or nitrogen (N); and

in [Chemical Formula III], R 11 is a substituted or unsubstituted C 1-10 alkylene group, a substituted or unsubstituted C 4-14 cycloalkylene group, a substituted or unsubstituted C 6-14 arylene group or a combination thereof; R 12 is hydrogen or a methyl group; X 6 is oxygen (O) or nitrogen (N).

9. The radical-curable adhesive composition of claim 1 , further comprising a (E) multifunctional (meth)acryl-based compound.

10. The radical-curable adhesive composition of claim 9 , wherein the (E) multifunctional (meth)acryl-based compound is included in 5 to 40 parts by weight with respect to 100 parts by weight of the radical-curable adhesive composition.

11. The radical-curable adhesive composition of claim 9 , wherein the (E) multifunctional (meth)acryl-based compound is one or more types selected from the group consisting of compounds represented by the following [Chemical Formula IV] to [Chemical Formula VI]:

wherein, in [Chemical Formula IV], R 13 and R 14 are each independently a (meth)acryloyloxy group or a (meth)acryloyloxyalkyl group;

in [Chemical Formula V], R 15 , R 16 and R 17 are each independently a (meth)acryloyloxy group or a (meth)acryloyloxyalkyl group, and R 18 is a (meth)acryloyloxy group, a (meth)acryloyloxyalkyl group, a hydroxyl group or a substituted or unsubstituted C 1-10 alkyl group; and

in [Chemical Formula VI], R 19 is substituted or unsubstituted C 1-10 alkylene, and R 20 and R 21 are each independently a (meth)acryloyloxy group or a (meth)acryloyloxyalkyl group.

12. The radical-curable adhesive composition of claim 1 , wherein a thickness of an adhesive layer formed by the radical-curable adhesive composition is 10 μm or less.

13. The radical-curable adhesive composition of claim 1 , which has a glass transition temperature of 50° C. or higher after curing.

14. The radical-curable adhesive composition of claim 1 , which has viscosity of 70 cP or less.

15. A polarizing plate comprising:

a polarizer;

an adhesive layer formed on at least one surface of the polarizer; and

a polarizer protective film formed on the adhesive layer;

wherein the adhesive layer is formed using the radical-curable adhesive composition of claim 1 .

16. An optical member comprising:

a display panel; and

a polarizer attached to an external-most surface of the display panel through a medium of an adhesive layer;

wherein the adhesive layer is formed using the radical-curable adhesive composition of claim 1 .