Photoalignment materials having improved adhesion

An optical element comprising:

• (i) a substrate;
• and
• (ii) a first at least partial layer on at least a portion of a surface of the substrate, the layer comprising a (co)polymeric material having a structure represented by the formula:
• where:
• each Ma, Mb, and Mc are each independently residues of substituted or unsubstituted acryloyl units, wherein said acryloyl substituents are selected from the group consisting of C1-C4 alkyl, phenyl, —O— and combinations thereof,
• substituted or unsubstituted styrene units,
• substituted or unsubstituted epoxy units,
• substituted or unsubstituted urethane units,
• substituted or unsubstituted polycarboxylic acid,
• substituted or unsubstituted polyol units,
• substituted or unsubstituted polyamine units, or
• substituted or unsubstituted hydroxyalkanoic acid units;
• wherein said substituents are selected from the group consisting of C1-C20 alkyl, C1-C20 alkoxy, C3-C10 cycloalkyl, C1-C20 alkyl(C1-C20)alkoxy, halo(C1-C20)alkyl, heterocyclo(C3-C10)alkyl, haloaryl, halo(C1-C20)alkylaryl, C1-C20 alkylaryl, C1-C20 alkoxyaryl, heteroaryl, aryl(C1-C20)alkyl, and heteroaryl(C1-C20)alkyl;
• La, Lb, and Lc are spacer groups that are each independently a single bond, —(CH2)g—, —(CF2)h—, —Si(Z′)2(CH2)g—, or —(Si(CH3)2O)h—, —N(R)—, —C(R)═C(R)—, —C(R)═N—, —C(R′)2—C(R′)2—, —O—, —C(O)—, —C≡C—, —N═N—, —S—, —S(O)—, —S(O)(O)—, —(O)S(O)O—, —O(O)S(O)O—, straight-chain or branched C1-C24 alkylene residue, arylene, C3-C10 cycloalkylene, or various combinations thereof, wherein Z′ is independently for each occurrence hydrogen, C1-C18 alkyl, C3-C10 cycloalkyl or aryl;
• R is independently for each occurrence Zb, hydrogen, C1-C18 alkyl, C3-C10 cycloalkyl or aryl;
• R′ is independently for each occurrence Zb, C1-C18 alkyl, C3-C10 cycloalkyl or aryl;
• the C1-C24 alkylene residue is mono-substituted by Zb, cyano, or halo, or poly-substituted by Zb or halo;
• “g” is independently for each occurrence 1 to 20, and “h” is a whole number from 1 to 16 inclusive;
• each Za is independently a photochemically active chromophore which is a dimerizable substituted or unsubstituted cinnamate, a dimerizable substituted or unsubstituted coumarin, a cis/trans isomerizable substituted or unsubstituted azo, a photochemically decomposable substituted or unsubstituted polyimide, or a substituted or unsubstituted aromatic ester capable of undergoing a Photo-Fries rearrangement;
• each Zb is independently an adhesion promoter group which is hydroxy, carboxylic acid, anhydride, isocyanato, blocked isocyanato, thioisocyanato, blocked thioisocyanato, thio, organofunctional silane, organofunctional titanate, or organofunctional zirconate, wherein each organofunctional group is independently selected from the group consisting of vinyl, allyl, vinyl-functional hydrocarbon radicals, epoxy-functional hydrocarbon radicals, allyl-functional hydrocarbon radicals, acryloyl-functional hydrocarbon radicals, methacryloyl-functional hydrocarbon radicals, styryl-functional hydrocarbon radicals, mercapto-functional hydrocarbon radicals, and combinations of such organofunctional groups, said hydrocarbon radicals being selected from the group consisting of C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, C1-C20 alkoxy, C1-C20 alkyl(C1-C20)alkoxy, C1-C20 alkoxy(C1-C20)alkyl, aryl, heteroaryl, and combinations of such hydrocarbon radicals;
• provided that when Zb is hydroxy or carboxylic acid, the (co)polymer further comprises at least one other adhesion promoter group;
• each Zc is independently a mesogen structure selected from the group consisting of a rigid straight rod-like liquid crystal group, and a rigid bent rod-like liquid crystal group;
• and
• “x” has a value of 0<x≤1, “y” has a value of 0≤y<1, and “z” has a value of 0≤z<1 where x+y+z=1 and “n” has a value ranging from 10 to 10,000,
• wherein when x=1, then at least one of La and Za is further substituted with at least one Zb adhesion promoter group and when y=0, then at least one of La, Za, Lc and Zc is further substituted with at least one Zb adhesion promoter group;
• and
• (iii) at least a second at least partial layer on a surface of the first at least partial layer, wherein the second at least partial layer comprises at least one liquid crystal material comprising at least one dichroic material and/or at least one photochromic-dichroic material.

A liquid crystal cell comprising:

• a first substrate having a first surface;
• a second substrate having a second surface opposite the first surface;
• a first at least partial layer on at least a portion of the first surface facing the second surface;
• a second at least partial layer on at least a portion of the second surface facing the first surface, the first at least partial layer and the second at least partial layer defining a space;
• and
• a liquid crystal material in the space between the first at least partial layer and the second at least partial layer,
• wherein the first at least partial layer and the second at least partial layer are alignment layers and at least one of the first at least partial layer and the second at least partial layer comprises a (co)polymer having a structure represented by the formula:
• where:
• each Ma, Mb, and Mc are each independently residues of substituted or unsubstituted acryloyl units, wherein said acryloyl substituents are selected from the group consisting of C1-C4 alkyl, phenyl, —O— and combinations thereof,
• substituted or unsubstituted styrene units,
• substituted or unsubstituted epoxy units,
• substituted or unsubstituted urethane units,
• substituted or unsubstituted polycarboxylic acid,
• substituted or unsubstituted polyol units,
• substituted or unsubstituted polyamine units, or
• substituted or unsubstituted hydroxyalkanoic acid units;
• wherein said substituents are selected from the group consisting of C1-C20 alkyl, C1-C20 alkoxy, C3-C10 cycloalkyl, C1-C20 alkyl(C1-C20)alkoxy, halo(C1-C20)alkyl, heterocyclo(C3-C10)alkyl, haloaryl, halo(C1-C20)alkylaryl, C1-C20 alkyl aryl, C1-C20 alkoxyaryl, heteroaryl, aryl(C1-C20)alkyl, and heteroaryl(C1-C20)alkyl;
• La, Lb, and Lc are spacer groups that are each independently a single bond, —(CH2)g—, —(CF2)h—, —Si(Z′)2(CH2)g—, or —(Si(CH3)2O)h—, —N(R)—, —C(R)═C(R)—, —C(R)═N—, —C(R′)2—C(R′)2—, —O—, —C(O)—, —C≡C—, —N═N—, —S—, —S(O)—, —S(O)(O)—, —(O)S(O)O—, —O(O)S(O)O—, straight-chain or branched C1-C24 alkylene residue, arylene, C3-C10 cycloalkylene, or various combinations thereof, wherein Z′ is independently for each occurrence hydrogen, C1-C18 alkyl, C3-C10 cycloalkyl or aryl;
• R is independently for each occurrence Zb, hydrogen, C1-C18 alkyl, C3-C10 cycloalkyl or aryl;
• R′ is independently for each occurrence Zb, C1-C18 alkyl, C3-C10 cycloalkyl or aryl;
• the C1-C24 alkylene residue is mono-substituted by Zb, cyano, or halo, or poly-substituted by Zb or halo;
• “g” is independently for each occurrence 1 to 20, and “h” is a whole number from 1 to 16 inclusive;
• each Za is independently a photochemically active chromophore which is a dimerizable substituted or unsubstituted cinnamate, a dimerizable substituted or unsubstituted coumarin, a cis/trans isomerizable substituted or unsubstituted azo, a photochemically decomposable substituted or unsubstituted polyimide, or a substituted or unsubstituted aromatic ester capable of undergoing a Photo-Fries rearrangement;
• each Zb is independently an adhesion promoter group which is hydroxy, carboxylic acid, anhydride, isocyanato, blocked isocyanato, thioisocyanato, blocked thioisocyanato, thio, organofunctional silane, organofunctional titanate, or organofunctional zirconate, or epoxy, wherein each organofunctional group is independently selected from the group consisting of vinyl, allyl, vinyl-functional hydrocarbon radicals, epoxy-functional hydrocarbon radicals, allyl-functional hydrocarbon radicals, acryloyl-functional hydrocarbon radicals, methacryloyl-functional hydrocarbon radicals, styryl-functional hydrocarbon radicals, mercapto-functional hydrocarbon radicals, and combinations of such organofunctional groups, said hydrocarbon radicals being selected from the group consisting of C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, C1-C20 alkoxy, C1-C20 alkyl(C1-C20)alkoxy, C1-C20 alkoxy(C1-C20)alkyl, aryl, heteroaryl, and combinations of such hydrocarbon radicals;
• provided that when Zb is hydroxy or carboxylic acid, the (co)polymer further comprises at least one other adhesion promoter group;
• each Zc is independently a mesogen structure selected from the group consisting of a rigid straight rod-like liquid crystal group, and a rigid bent rod-like liquid crystal group;
• and
• “x” has a value of 0<x≤1, “y” has a value of 0≤y<1, and “z” has a value of 0≤z<1 where x+y+z=1 and “n” has a value ranging from 10 to 10,000,
• wherein when x=1, then at least one of La and Za is further substituted with at least one Zb adhesion promoter group and when y=0, then at least one of La, Za, Lc and Zc is further substituted with at least one Zb adhesion promoter group.

A method of applying a photoalignment material to an optical element comprising:

• applying an at least partial layer of a photoalignment (co)polymer material onto at least a portion of a surface of a substrate;
• forming an attractive bond between one or more adhesion promoter groups on the photoalignment (co)polymer material and a compatible group on the surface of the substrate;
• and
• at least partially aligning at least a first portion of the photoalignment (co)polymer material by exposing the at least partial layer to polarized UV radiation,
• wherein the photoalignment (co)polymer material has a structure represented by the formula:
• where:
• each Ma, Mb, and Mc are each independently residues of substituted or unsubstituted acryloyl units, wherein said acryloyl substituents are selected from the group consisting of C1-C4 alkyl, phenyl, —O— and combinations thereof,
• substituted or unsubstituted styrene units,
• substituted or unsubstituted epoxy units,
• substituted or unsubstituted urethane units,
• substituted or unsubstituted polycarboxylic acid,
• substituted or unsubstituted polyol units,
• substituted or unsubstituted polyamine units, or
• substituted or unsubstituted hydroxyalkanoic acid units;
• wherein said substituents are selected from the group consisting of C1-C20 alkyl, C1-C20 alkoxy, C3-C10 cycloalkyl, C1-C20 alkyl(C1-C20)alkoxy, halo(C1-C20)alkyl, heterocyclo(C3-C10)alkyl, haloaryl, halo(C1-C20)alkylaryl, C1-C20 alkylaryl, C1-C20 alkoxyaryl, heteroaryl, aryl(C1-C20)alkyl, and heteroaryl(C1-C20)alkyl;
• La, Lb, and Lc are spacer groups that are each independently a single bond, —(CH2)g—, —(CF2)h—, —Si(Z′)2(CH2)g—, or —(Si(CH3)2O)h—, —N(R)—, —C(R)═C(R)—, —C(R)═N—, —C(R′)2—C(R′)2—, —O—, —C(O)—, —C≡C—, —N═N—, —S—, —S(O)—, —S(O)(O)—, —(O)S(O)O—, —O(O)S(O)O—, straight-chain or branched C1-C24 alkylene residue, arylene, C3-C10 cycloalkylene, or various combinations thereof, wherein Z′ is independently for each occurrence hydrogen, C1-C18 alkyl, C3-C10 cycloalkyl or aryl;
• R is independently for each occurrence Zb, hydrogen, C1-C18 alkyl, C3-C10 cycloalkyl or aryl;
• R′ is independently for each occurrence Zb, C1-C18 alkyl, C3-C10 cycloalkyl or aryl;
• the C1-C24 alkylene residue is mono-substituted by Zb, cyano, or halo, or poly-substituted by Zb or halo;
• “g” is independently for each occurrence 1 to 20, and “h” is a whole number from 1 to 16 inclusive;
• each Za is independently a photochemically active chromophore which is a dimerizable substituted or unsubstituted cinnamate or substituted or unsubstituted coumarin, a cis/trans isomerizable substituted or unsubstituted azo, a photochemically decomposable substituted or unsubstituted polyimide, or a substituted or unsubstituted aromatic ester capable of undergoing a Photo-Fries rearrangement;
• each Zb is independently an adhesion promoter group which is hydroxy, carboxylic acid, anhydride, isocyanato, blocked isocyanato, thioisocyanato, blocked thioisocyanato, thio, organofunctional silane, organofunctional titanate, or organofunctional zirconate, or epoxy, wherein each organofunctional group is independently selected from the group consisting of vinyl, allyl, vinyl-functional hydrocarbon radicals, epoxy-functional hydrocarbon radicals, allyl-functional hydrocarbon radicals, acryloyl-functional hydrocarbon radicals, methacryloyl-functional hydrocarbon radicals, styryl-functional hydrocarbon radicals, mercapto-functional hydrocarbon radicals, and combinations of such organofunctional groups, said hydrocarbon radicals being selected from the group consisting of C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, C1-C20 alkoxy, C1-C20 alkyl(C1-C20)alkoxy, C1-C20 alkoxy(C1-C20)alkyl, aryl, heteroaryl, and combinations of such hydrocarbon radicals;
• provided that when Zb is hydroxy or carboxylic acid, the (co)polymer further comprises at least one other adhesion promoter group;
• each Zc is independently a mesogen structure selected from the group consisting of a rigid straight rod-like liquid crystal group, and a rigid bent rod-like liquid crystal group, and a rigid disc like liquid crystal group;
• and
• “x” has a value of 0<x≤1, “y” has a value of 0≤y<1, and “z” has a value of 0≤z<1 where x+y+z=1 and “n” has a value ranging from 10 to 10,000,
• wherein when x=1, then at least one of La and Za is further substituted with at least one Zb adhesion promoter group and when y=0, then at least one of La, Za, Lc and Zc is further substituted with at least one Zb adhesion promoter group.