An electrochromic compound represented by the following formula (1) is provided: ##STR00001## where each of R.sub.1 to R.sub.9 and Ar.sub.1 to Ar.sub.6 independently represents one of a hydrogen atom, a halogen atom, a monovalent organic group, a group in which two or more aryl and/or heteroaryl groups are bound to each other via a covalent bond, a group in which two or more aryl and/or heteroaryl groups are condensed with each other to form a ring, and a polymerizable functional group; and at least one of Ar.sub.1 to Ar.sub.6 represents an aryl group, a heteroaryl group, a group in which two or more aryl and/or heteroaryl groups are bound to each other via a covalent bond, or a group in which at least two aryl or heteroaryl groups are condensed with each other to form a ring.

An electrochromic compound represented by the following formula (1) is provided: ##STR00001## where each of R.sub.1 to R.sub.9 and Ar.sub.1 to Ar.sub.6 independently represents one of a hydrogen atom, a halogen atom, a monovalent organic group, a group in which two or more aryl and/or heteroaryl groups are bound to each other via a covalent bond, a group in which two or more aryl and/or heteroaryl groups are condensed with each other to form a ring, and a polymerizable functional group; and at least one of Ar.sub.1 to Ar.sub.6 represents an aryl group, a heteroaryl group, a group in which two or more aryl and/or heteroaryl groups are bound to each other via a covalent bond, or a group in which at least two aryl or heteroaryl groups are condensed with each other to form a ring.

In an embodiment, the present disclosure pertains to a method of changing the glass transition temperature of a polymer. In some embodiments, the polymer includes at least one hydrazone-containing compound. In general, the methods of the present disclosure include one or more of the following steps of: (1) applying light to the polymer; and (2) thereby changing the glass transition temperature of the polymer. In another embodiment, the present disclosure pertains to a polymer having a light-adjustable glass transition temperature. In some embodiments, the polymer includes at least one hydrazone-containing compound.

Provided is a method for producing a dental curable composition, the method includes mixing a polymerizable monomer (A); a spherical filler (B) having an average primary particle diameter within a range of 230 nm to 290 nm; a spherical filler (C) having an average primary particle diameter within a range of 100 nm to 500 nm, the spherical filler having an average primary particle diameter different from that of the spherical filler (B); and a polymerization initiator (D), in which 90% or more in number of the individual particles constituting the spherical filler (B) and the spherical filler (C) are present in a range of 5% from the average primary particle diameter, and the refractive indices of the spherical filler (B) and the spherical filler (C) are larger than the refractive index of a polymer of a polymerizable monomer (A).

Provided is a method for producing a dental curable composition, the method includes mixing a polymerizable monomer (A); a spherical filler (B) having an average primary particle diameter within a range of 230 nm to 290 nm; a spherical filler (C) having an average primary particle diameter within a range of 100 nm to 500 nm, the spherical filler having an average primary particle diameter different from that of the spherical filler (B); and a polymerization initiator (D), in which 90% or more in number of the individual particles constituting the spherical filler (B) and the spherical filler (C) are present in a range of 5% from the average primary particle diameter, and the refractive indices of the spherical filler (B) and the spherical filler (C) are larger than the refractive index of a polymer of a polymerizable monomer (A).

In light of requests to reduce or reverse the wavelength dispersion of the birefringence of a phase-retardation film in order to increase the viewing angle of a liquid crystal display, the present invention provides a polymerizable compound that reduces, for example, the likelihood of crystals precipitating in a polymerizable composition including the polymerizable compound and enables the polymerizable composition to have high preservation stability and a polymerizable composition including the polymerizable compound which reduces the likelihood of inconsistencies being formed in a film-like polymer produced by polymerizing the polymerizable composition. Another object of the present invention is to provide a polymer produced by polymerizing the polymerizable composition and an optically anisotropic body including the polymer.

In light of requests to reduce or reverse the wavelength dispersion of the birefringence of a phase-retardation film in order to increase the viewing angle of a liquid crystal display, the present invention provides a polymerizable compound that reduces, for example, the likelihood of crystals precipitating in a polymerizable composition including the polymerizable compound and enables the polymerizable composition to have high preservation stability and a polymerizable composition including the polymerizable compound which reduces the likelihood of inconsistencies being formed in a film-like polymer produced by polymerizing the polymerizable composition. Another object of the present invention is to provide a polymer produced by polymerizing the polymerizable composition and an optically anisotropic body including the polymer.

The invention provides a polymerizable compound of formula (I), polymerizable composition, polymer, and optically anisotropic article capable of obtaining an optical film having a low melting point, excellent solubility, being manufactured at low cost, and of uniform polarized light conversion across a broad wavelength region. In formula (I): Y.sup.1 to Y.sup.6 are independently a chemical single bond, O, OC(O), C(O)O; G.sup.1 and G.sup.2 are independently a divalent C1-C20 aliphatic group; Z.sup.1 and Z.sup.2 are independently a C2-C10 alkenyl group substituted with a halogen atom; A.sup.x is a C2-C30 organic group that includes at least one aromatic ring of an aromatic hydrocarbon ring or an aromatic hetero ring; A.sup.y is H, a C1-C20 alkyl group, a C2-C20 alkenyl group, a C3-C12 cycloalkyl group; A.sup.1 is a trivalent aromatic group; A.sup.2 and A.sup.3 are independently a divalent C6-C30 aromatic group; and Q.sup.1 is H, or a C1-C6 alkyl group. ##STR00001##

The invention provides a polymerizable compound of formula (I), polymerizable composition, polymer, and optically anisotropic article capable of obtaining an optical film having a low melting point, excellent solubility, being manufactured at low cost, and of uniform polarized light conversion across a broad wavelength region. In formula (I): Y.sup.1 to Y.sup.6 are independently a chemical single bond, O, OC(O), C(O)O; G.sup.1 and G.sup.2 are independently a divalent C1-C20 aliphatic group; Z.sup.1 and Z.sup.2 are independently a C2-C10 alkenyl group substituted with a halogen atom; A.sup.x is a C2-C30 organic group that includes at least one aromatic ring of an aromatic hydrocarbon ring or an aromatic hetero ring; A.sup.y is H, a C1-C20 alkyl group, a C2-C20 alkenyl group, a C3-C12 cycloalkyl group; A.sup.1 is a trivalent aromatic group; A.sup.2 and A.sup.3 are independently a divalent C6-C30 aromatic group; and Q.sup.1 is H, or a C1-C6 alkyl group. ##STR00001##

Provided is a method for producing a dental curable composition, the method includes mixing a polymerizable monomer (A); a spherical filler (B) having an average primary particle diameter within a range of 230 nm to 290 nm; a spherical filler (C) having an average primary particle diameter within a range of 100 nm to 500 nm, the spherical filler having an average primary particle diameter different from that of the spherical filler (B); and a polymerization initiator (D), in which 90% or more in number of the individual particles constituting the spherical filler (B) and the spherical filler (C) are present in a range of 5% from the average primary particle diameter, and the refractive indices of the spherical filler (B) and the spherical filler (C) are larger than the refractive index of a polymer of a polymerizable monomer (A).