| 摘要 |
PROBLEM TO BE SOLVED: To provide a curable composition capable of giving a colorless, transparent cured material, that is heat resistant, little in fluctuation of refractive index at a using environment, by controlling dependence of refractive index on temperature and moisture absorption. SOLUTION: The curable composition comprises a specified bis(meth)acrylate, a specified mono(meth)acrylate, and a (meth)acrylate of at least 1,000 number-average molecular weight, has a viscosity of at least 100 mPa s at 50°C, and contains less than 0.5 pt.wt. photopolymerization initiator to 100 pts. wt (meth)acrylate contained in the composition. Rate of curing contraction is less than 10% when the curable composition is cured by heating for 4 hours under vacuum at 150°C after radiating by 10 J/cm<SP>2</SP>luminous energy of 360 nm central wave length. The cured product shows fluctuation of refractive index of from -0.0005 to +0.0005 against 1% weight change by moisture absorption, and a cured product of 2 mm thickness shows yellow degree (YI value) of not more than 10. COPYRIGHT: (C)2008,JPO&INPIT
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