The purpose of the present invention is to provide a high temperature/humidity resistant polycarbonate resin without using bisphenol A as a raw material. The present invention relates to a polycarbonate resin comprising the repeating units of formulas (1), (2) and (3), wherein the content of the repeating unit of formula (3) is 5 mol% to 50 mol%, and the refractive index is 1.570 to 1.600. {In formula (1), R.sub.1 and R.sub.2 each represent a hydrogen atom or a C.sub.1-10 hydrocarbon group.} {In formula (3), n ranges from 0 to 8, and the R symbols are each selected from C.sub.1-3 alkyl groups}. ##STR00001##

A phase difference film and a circularly polarizing film each achieve suppressed coloration when viewed from the front direction, a smaller difference in tint between views from the front direction and the oblique direction, and suppressed image unevenness, where the film is applied to an image display panel, in particular, an organic EL panel; as well as an image display device including the circularly polarizing film. The phase difference film includes optically anisotropic layers A and B, in which a retardation RthA of layer A in the thickness direction at a wavelength of 550 nm is larger than 0, layer A exhibits predetermined optical properties, a retardation RthB of layer B in the thickness direction at a wavelength of 550 nm is smaller than 0, layer B satisfies predetermined optical properties, and the angle formed between a slow axis of the optically anisotropic layers A and B is 90°±10°.

The purpose of the present invention is to provide a thermoplastic resin far an optical lens. In order to enable an optical lens designer to use a variety of lenses, the thermoplastic resin should have a low refractive index, a low Abbe number and a water absorption rate similar to that of a polycarbonate resin. The present invention relates to a thermoplastic resin which contains repeating units represented by formula (1), formula (2) and formula (3) and which has a refractive index of 1.510-1.570. In formula (I), R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently a hydrogen atom or a hydrocarbon group having 1-10 carbon atoms. In formula (3), n is 1-8, R moieties are each independently selected from among a hydrogen atom or an alkyl group having 1-3 carbon atoms, and R.sub.5 and R.sub.6 are each independently a hydrogen atom or a hydrocarbon group having 1-10 carbon atoms.

Provided is a compound represented by General Formula (1)

##STR00001##

in General Formula (1), Ar.sub.1 and Ar.sub.2 independently represent a group selected from the following Formulae,

##STR00002##

The present application provides a polycarbonate resin including structural units (A) represented by general formula (1) and structural units (B) represented by general formula (4).

##STR00001##

(In general formula (1), R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, and R.sub.8 each independently represents a hydrogen atom, etc., and X represents —O—, etc.)

##STR00002##

(In general formula (4), R.sub.z and R.sub.x each independently represents a hydrogen atom or a C1-3 alkyl group, i represents an integer 3-10 and p represents an integer 5-600.)

The present application provides: a polycarbonate resin which has heat resistance and is able to be produced using a starting material that is derived from natural products; and a monomer compound which enables the achievement of this resin. A polycarbonate resin which includes a constituent unit represented by general formula (1); a monomer compound which enables the achievement of this resin; and a polycarbonate resin which includes a constituent unit represented by general formula (1) and a constituent unit represented by general formula (2).

##STR00001##

Provided are a polycarbonate resin and an optical film formed therefrom, having wavelength dispersion characteristics close to the ideal broad bandwidth, excellent durable stability and flexibility, high retardation developability, a low photoelastic constant, and excellent melt processability. The polycarbonate resin comprises a unit (A) represented by the following formula, wherein R.sub.1 and R.sub.2 each independently represent a hydrogen atom, hydrocarbon group having 1 to 10 carbon atoms optionally containing an aromatic group, or a halogen atom, and m and n each independently represent an integer of 0 to 4: ##STR00001##
a unit (B) represented by the following formula, wherein R.sub.3 and R.sub.4 each independently represent a hydrogen atom, hydrocarbon group having 1 to 10 carbon atoms optionally containing an aromatic group, or a halogen atom, R.sub.5 and R.sub.6 each independently represent a hydrocarbon group having 1 to 10 carbon atoms optionally containing an aromatic group, s and t each independently represent an integer of 0 to 4, and p and q each independently represent an integer of 1 or more: ##STR00002##
and a carbonate unit (C) derived from an aliphatic diol compound and/or alicyclic diol compound, wherein the polycarbonate resin satisfies the following expressions (I) and (II): (I) the molar ratio of unit (A) to unit (B), (A)/(B), is 0.2 to 11.0, and (II) the molar ratio of unit (A)+unit (B) to the (A)+unit (B)+unit (C), {(A+B)/(A+B+C)}, is 0.30 to 0.60.

[Problem] An object of the present invention is to provide a thermoplastic resin having high refractive index and low Abbe number and an optical member containing the same.

[Solution] A thermoplastic resin having repeating units represented by the following formula (1):

##STR00001##

wherein Z is a polycyclic aromatic hydrocarbon having three or more benzene rings condensed, each of L.sup.1 and L.sup.2 independently represents a divalent linking group, each of R.sup.1 and R.sup.2 independently represents a hydrogen atom, a halogen atom, or a substituent having 1 to 20 carbon atoms and optionally containing an aromatic group, each of j1 and j2 independently represents an integer of 1 or more, each of m and n independently represents 0 or 1, and W is at least one selected from the group represented by the following formulae (2) and (3):

##STR00002##

wherein X represents a divalent linking group.

A polycarbonate polyester includes residues of following formula (1), formula (2) and formula (3): ##STR00001## in which R.sub.1 is C.sub.2-C.sub.15 hydrocarbon group; R.sub.2 is C.sub.4-C.sub.16 hydrocarbon group; a molar ratio of the residue of the formula (2) to the residue of the formula (1) is in a range of greater than 0.05 to less than 0.8; * represents a linking bond.

The present invention relates to a polycarbonate resin containing, in the molecule, a structure represented by the following formula (1):

##STR00001##

wherein X has a structure represented by any one of the following formulae (2) to (4):

##STR00002##

wherein each of R.sup.1 to R.sup.4 independently represents a hydrogen atom or an organic group having a carbon number of 1 to 30; the organic group may have an arbitrary substituent, and any two or more members of R.sup.1 to R.sup.4 may combine with each other to form a ring, which is excellent in heat resistance, transparency, light resistance, weather resistance and mechanical strength.