Radical curable adhesive composition, and polarizing plate and optical member comprising same
The present invention relates to a radical-curable adhesive composition including an acid anhydride-based compound having at least one carbon-carbon unsaturated double bond, a vinyl-based compound having at least one electron donor group, a radical initiator, and a cation generator, wherein the content of the acid anhydride-based compound and the vinyl-based compound is 0.8 to 1.0 by an equivalence ratio of mixing represented by the following Equation (1), and a polarizing plate and an optical member including the radical-curable adhesive composition: Equivalence Ratio of Mixing= M/N, Equation(1): and in Equation (1), M is the number of carbon-carbon unsaturated double bonds capable of participating in polymerization in the molecule including an acid anhydride group included in the acid anhydride-based compound; and N is the number of carbon-carbon unsaturated double bonds capable of participating in polymerization in the molecule included in the vinyl-based compound.
1. A radical-curable adhesive composition comprising:
an acid anhydride-based compound having at least one carbon-carbon unsaturated double bond;
a vinyl-based compound having at least one electron donor group;
a radical initiator; and
a cation generator,
wherein a content of the acid anhydride-based compound and the vinyl-based compound is 0.8 to 1.0 by an equivalence ratio of mixing represented by the following Equation (1):
Equivalence Ratio of Mixing= M/N , and Equation (1):
wherein in Equation (1), M is the number of carbon-carbon unsaturated double bonds capable of participating in polymerization in the molecule including an acid anhydride group included in the acid anhydride-based compound; and N is the number of carbon-carbon unsaturated double bonds capable of participating in polymerization in the molecule included in the vinyl-based compound.
2. The radical-curable adhesive composition of claim 1 , wherein the acid anhydride-based compound includes one or more types of compounds selected from the group consisting of compounds represented by the following [Chemical Formula I] to [Chemical Formula IV]:
wherein, in [Chemical Formula I], R 1 is a (meth)acryloyl group, a (meth)acryloylalkyl group or a (meth)acryloyloxyalkyl group; R 2 is a halogen atom or a C 1˜10 alkyl group; a is an integer of 1 or 2; b is an integer of 0 to 2; and X 1 is a single bond, —O—, —CO—, —COO— or —OCO—;
wherein in [Chemical Formula II], R 3 to R 5 are each independently hydrogen or a halogen atom; or a C 1˜10 alkyl group, a C 4˜14 cycloalkyl group, a C 6˜14 aryl group or a combination thereof;
wherein in [Chemical Formula III], R 6 and R 7 are each independently hydrogen or a halogen atom; or a C 1˜10 alkyl group, a C 4˜14 cycloalkyl group, a C 6˜14 aryl group or a combination thereof; and
wherein in [Chemical Formula IV], R 8 to R 11 are each independently hydrogen or a halogen atom; or a C 1˜10 alkyl group, a C 4˜14 cycloalkyl group, a C 6˜14 aryl group or a combination thereof.
3. The radical-curable adhesive composition of claim 1 , wherein the electron donor group of the vinyl-based compound is a functional group represented by the following [Chemical Formula A] or [Chemical Formula B]:
wherein, in [Chemical Formula A], R 12 is hydrogen or a C 1˜10 alkyl group; and
wherein in [Chemical Formula B], R 13 is hydrogen or a C 1˜10 alkyl group.
4. The radical-curable adhesive composition of claim 1 , wherein the vinyl-based compound is a compound represented by the following [Chemical Formula V]:
wherein, in [Chemical Formula V], R 14 is hydrogen or a C 1˜10 alkyl group; R 15 is a C 1˜10 aliphatic chain, a C 4˜14 aliphatic ring or a C 6˜14 aromatic ring, which has a valency of c, or a combination thereof; c is an integer of 1 to 4; and X 2 is —O— or —OCO—.
5. The radical-curable adhesive composition of claim 1 , further comprising a radical-polymerizable compound represented by the following [Chemical Formula VI]:
wherein, in [Chemical Formula VI], R 16 is an ester group (—COO—), an amide group (—CON—) or a thioate group (—COS—); R 17 is a C 1˜10 alkyl cycloalkyl group or a group, a C 4˜10 combination thereof, and herein, R 17 has at least one hydroxyl substituent in the molecule; and R 18 is hydrogen or a C 1˜10 alkyl group.
6. The radical-curable adhesive composition of claim 5 , comprising:
the acid anhydride-based compound and the vinyl-based compound in 1 to 50 parts by weight;
the radical-polymerizable compound in 40 to 97 parts by weight;
the radical initiator in 1 to 10 parts by weight; and
the cation generator in 1 to 10 parts by weight, with respect to 100 parts by weight of the radical-curable adhesive composition.
7. The radical-curable adhesive composition of claim 1 , which has a glass transition temperature of 60° C. or higher after curing.
8. The radical-curable adhesive composition of claim 1 , which has viscosity of 10 to 200 cP.
9. A polarizing plate comprising:
a polyvinyl alcohol-based polarizer;
an adhesive layer formed on at least one surface of the polarizer; and
a protective film formed on the adhesive layer,
wherein the adhesive layer is formed using the radical-curable adhesive composition of claim 1 .
10. The polarizing plate of claim 9 , wherein the polarizer and the adhesive layer secure adhesive strength through covalent bonding produced as a result of an esterification reaction between a hydroxyl group of the polarizer and an acid anhydride group of the adhesive layer.
11. An optical member comprising:
a display panel; and
a polyvinyl alcohol-based 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 .
12. The optical member of claim 11 , wherein the polarizer and the adhesive layer secure adhesive strength through covalent bonding produced as a result of an esterification reaction between a hydroxyl group of the polarizer and an acid anhydride group of the adhesive layer.