Co-overlays, components for photoalignment films, photoalignment films and optical anisotropy elements

Abstract

An object of the present invention is to provide a copolymer that exhibits good solubility in a solvent when used as an optical material and good orientation when used as an optical material, and a composition for an optical alignment film, an optical alignment film, and an optically anisotropic element using the copolymer. 【Solution means】A copolymer (P) having structural units A, B, and C represented by the following formulas (A), (B), and (C), respectively. When the total of the structural units A, B, and C is 100 mol%, the copolymer (P) in which the total of the ratio of the structural unit A and the ratio of the structural unit B is 5 mol% or more and less than 25 mol%. TIFF2026093802000021.tif3865 (R a ~R c is H or a methyl group, L a and L b is a divalent linking group having a hydroxyl group, L c is a divalent linking group having no hydroxyl group, X a is a group containing a structure derived from a predetermined cinnamic acid, X b is a group containing a (meth)acryloyloxy group, X c is a cationic polymerizable group containing oxygen as a ring atom)

Claims

1. A copolymer (P) having a constituent unit A represented by formula (A), a constituent unit B represented by formula (B), and a constituent unit C represented by formula (C), A copolymer (P) in which, when the sum of the constituent units A, B, and C is 100 mol%, the sum of the proportions of constituent unit A and B is 5 mol% or more and less than 25 mol%. 【Chemistry 1】 (In the above formulas (A) to (C), R a ~R c Each of these independently represents either a hydrogen atom or a methyl group. L a and L b Each of these independently represents a divalent linking group having a hydroxyl group. L c This represents a divalent linking group that does not have a hydroxyl group. X a The following equation (X a1 ) or (X a2 It represents the base represented by ), 【Chemistry 2】 (In formula (X a1 ) and (X a2 ), R Xa1 This is a hydrogen atom, a hydroxyl group, or a carbon-1 to carbon-6 alkoxy group which may be substituted with at least one hydrogen atom. R Xa2 This is a hydrogen atom, a halogen, a hydroxyl group, a C1-C6 alkoxy group which may have at least one hydrogen atom substituted, or a C2-C20 hydrocarbon group which may have at least one hydrogen atom substituted, may have at least one ester bond, and may have at least one cyclic structure. * is L a (Represents the connection point with) X b This represents a group containing a (meth)acryloyloxy group, X c (This represents a cationic polymerizable group containing oxygen as a ring atom.)

2. The copolymer (P) according to claim 1, wherein the cationic polymerizable group is at least one selected from epoxy groups and oxetane groups.

3. The aforementioned cationic polymerizable group is defined by the following formula X c1 ~X c5 The copolymer (P) according to claim 1, which is any of the representations shown. 【Transformation 3】 (In the formula, R Xc1 X represents a hydrogen atom, a halogen atom, a methyl group, an ethyl group, or a trifluoromethyl group. However, the above formula X c1 , X c2 , and X c5 Multiple R in Xc1 These may be the same or different. * is L c (Represents the connection point with)

4. Said L a and L b The copolymer (P) according to claim 1 or 2, wherein the copolymer is represented by the following formula. * 1 -L c -X c’ -* 2 (In the formula, X c’ The above X c A cationic polymerizable group containing oxygen as a ring atom opens its ring, * 2 X a or X b This represents a structure that is bonded to it. * 1 (This indicates the binding position on the main chain.)

5. The copolymer (P) according to claim 1 or 2, wherein when the sum of the constituent units A, B, and C is 100 mol%, the proportion of constituent unit A is 5 to 15 mol%, and the proportion of constituent unit B is 1 to 15 mol%.

6. The copolymer (P) according to claim 5, wherein when the sum of the constituent units A, B, and C is 100 mol%, the proportion of constituent unit C is 76 to 94 mol%.

7. A polymer (P') having the aforementioned structural unit C, and lacking the aforementioned structural unit A and the aforementioned structural unit B, The following equation (X a’ Compound A' represented by ) and Compound B' containing a (meth)acryloyloxy group having a hydroxyl group, The copolymer (P) according to claim 1 obtained by reacting the two. 【Chemistry 4】 (In the formula, R Xa1 and R Xa2 The same as above, and R Xa1 and R Xa2 (One of them is a hydroxyl group, and the other is not a hydroxyl group.)

8. A composition for photoalignment films containing the copolymer (P) described in claim 1.

9. Furthermore, the photo-alignment film composition according to claim 8, further containing an organic solvent.

10. Furthermore, the photo-alignment film composition according to claim 8, further comprising an acid generator.

11. A photoalignment film formed using the photoalignment film composition described in claim 8.

12. An optically anisotropic element having a photo-alignment film according to claim 11 and an optically anisotropic layer formed using an optically anisotropic layer-forming composition containing a polymerizable liquid crystal compound.

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