US 11,787,971 B2
Polarizing plate, image display device comprising same and photocurable composition for polarizing plate protection layer
Mi So Lee, Daejeon (KR); Sanghun Han, Daejeon (KR); and Yoonkyung Kwon, Daejeon (KR)
Assigned to SHANJIN OPTOELECTRONICS (SUZHOU) CO., LTD., Zhangjiagang (CN)
Appl. No. 16/766,141
Filed by SHANJIN OPTOELECTRONICS (SUZHOU) CO., LTD., Zhangjiagang (CN)
PCT Filed Nov. 23, 2018, PCT No. PCT/KR2018/014497
§ 371(c)(1), (2) Date May 21, 2020,
PCT Pub. No. WO2019/103514, PCT Pub. Date May 31, 2019.
Claims priority of application No. 10-2017-0158714 (KR), filed on Nov. 24, 2017.
Prior Publication US 2020/0362194 A1, Nov. 19, 2020
Int. Cl. C09D 163/00 (2006.01); G02B 1/14 (2015.01); C09D 7/40 (2018.01)
CPC C09D 163/00 (2013.01) [C09D 7/40 (2018.01); G02B 1/14 (2015.01)] 8 Claims
OG exemplary drawing
 
1. A polarizing plate comprising:
a polarizer; and
a protective layer in direct contact with at least one surface of the polarizer,
wherein the protective layer is a cured material of a photocurable composition for a polarizing plate protective layer comprising a photopolymerizable compound, and a photocation polymerization initiator; and wherein the photopolymerizable compound is formed from a first epoxy-based compound, a second epoxy-based compound and an oxetane compound, where in the first epoxy-based compound is 3,4-epoxycyclohexylmethyl-3′,4′-epoxycyclohexane carboxylate and the second epoxy-based compound is 1,4-cyclohexyl dimethanol diglycidyl ether, and the oxetane compound is 3-ethyl-3-[(3-ethyloxetan-3-yl)methoxymethyl]oxetane;
the first epoxy-based compound is included in 65 parts by weight with respect to a total 100 parts by weight of the photopolymerizable compound wherein the second epoxy-based compound is included in 20 parts by weight with respect to a total 100 parts by weight of the photopolymerizable compound, and the oxetane compound is included in 15 parts by weight of the photopolymerizable compound;
the photocation polymerization initiator comprises a short wavelength initiator and a long wavelength initiator;
the short wavelength initiator is (4-methylphenyl) [4-(2-methylpropyl)phenyl] iodonium hexafluorophosphate and is included in 2.1 parts by weight and the long wavelength initiator is isopropylthioxanthone and is included in 0.8 parts by weight with respect to a total 100 parts by weight of the photocurable composition for a polarizing plate protective layer;
the photocurable composition for a polarizing plate protective layer has viscosity of greater than or equal to 50 cps and less than or equal to 200 cps at 25° C.; and
the protective layer has storage modulus of 1,500 MPa to 10,000 MPa at 80° C.