Optical member and method of producing the same
Provided is an optical member where at least a layer having polyimide as a main component and a layer having a textured structure arising from a crystal containing aluminum oxide as a main component are stacked in this order. The polyimide includes a silane group in a side chain via an amide bond.
1. An optical member comprising:
a plurality of layers formed on a surface of a substrate, wherein
the plurality of layers includes layer having a textured structure comprising a crystal of aluminum oxide and layer having polyimide; and
the polyimide includes a repeated structure represented by Formula (1) and a structure represented by Formula (2) in a main chain:
wherein, R 1 represents a tetravalent organic group; and R 2 represents a divalent organic group, and
wherein, R 3 represents a tetravalent organic group; R 4 represents a phenylene group or a C1 to C5 alkylene group; R 5 represents a hydrogen atom, a linear or branched alkyl group, or a phenyl group or represents a structure binding to the substrate or another polymer through —Si≡; R 6 represents a hydrogen atom, a linear or branched alkyl group, or a phenyl group; m represents 0 or 1; n represents 1 or 2; m and n satisfy 2m+2n=4; and x represents an integer of 1 to 3,
wherein the molar quantity of the structure represented by Formula (2) contained in the polyimide is 0.002 to 0.05 based on 1 mole of the repeating unit represented by Formula (1) contained in the polyimide.
2. The optical member according to claim 1 , wherein
the polyimide has a structure represented by Formula (3) at a terminal:
wherein, R 7 represents a tetravalent organic group; R 8 represents a methyl group, an ethyl group, or an isopropyl group; R 9 represents a phenylene group or a C1 to C5 alkylene group; R 10 represents a hydrogen atom, a C1 to C5 linear or branched alkyl group, or a phenyl group or represents a structure binding to the substrate or another polymer through —Si≡; R 11 represents a hydrogen atom, a linear or branched alkyl group, or a phenyl group; y represents an integer of 1 to 3; and p represents 0 or 1.
3. The optical member according to claim 1 , wherein
the polyimide has a structure represented by Formula (4) at a terminal:
wherein R 12 represents a tetravalent organic group; R 13 represents a divalent organic group; and R 14 represents a C1 to C3 alkyl group or a fluoroalkyl group.
4. The optical member according to claim 1 , wherein
the layer having polyimide has a thickness of 10 nm or more and 150 nm or less.
5. The optical member according to claim 1 , wherein
the layer having polyimide is in direct contact with the substrate.
6. A photographing optical system comprising the optical member according to claim 1 .
7. An observation optical system comprising the optical member according to claim 1 .
8. A projecting optical system comprising the optical member according to claim 1 .
9. The optical member according to claim 1 , wherein polyimide contains a polyimide structure formed by the repeating structure represented by Formula (1) and the structure represented by Formula (2) as a main component.
10. The optical member according to claim 9 , wherein an amount of a component that is other than the polyimide structure formed by the repeating structure represented by Formula (1) and the structure represented by Formula (2), in an amount of less than 20 parts by weight based on 100 parts by weight of the polyimide structure.
11. The optical member according to claim 1 ,
wherein an imidization ratio of the polyimide is 96% or more and 99.8% or less.
12. The optical member according to claim 1 ,
wherein the layer having a textured structure is formed by treating aluminum oxide in hot water of 40° C. or more and 100° C. or less.