Diffraction grating
AssigneeCanon Kabushiki Kaisha
InventorHaruo Tomono
Life of this patent
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Abstract
A diffraction grating is constituted by a substrate and a resin layer having a repetitive pattern formed on the substrate. The resin layer is characterized by showing a Young's modulus at 100.degree. C. which is at least 2% of that at 20.degree. C. The resin layer may be obtained by curing a photocurable resin composition, including: (A) a polyfunctional urethane-modified polyester (meth)acrylate comprising a polyester oligomer and a plurality of (meth)cryloyl groups bonded to the polyester oligomer via a urethane group, and having a number-average molecular weight of at least 700, (B) a polyfunctional (meth)acrylate having a number-average molecular weight of less than 700, (C) a monofunctional (meth)acrylate, and (D) a photopolymerization initiator.
Claims4
A diffraction grating comprising:
- a substrate and a resin layer having a repetitive pattern formed on the substrate, wherein said resin layer comprises a cured product of a photocurable resin composition comprising:
- (i) 25-45 wt. % of (A) a polyfunctional urethane-modified polyester (meth)acrylate comprising a polyester oligomer and a plurality of (meth)acryloyl groups bonded to the polyester oligomer via a urethane group and having a number-average molecular weight of at least 800,
- (ii) 31-70 wt. % of (B) a polyfunctional (meth)acrylate having a number-average molecular weight of less than 650,
- (iii) 5-44 wt. % of (C) a monofunctional (meth) acrylate, and
- (iv) (D) a photopolymerization initiator.
Dependencies are inferred from the claim text.