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##

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##

Techniques regarding post polymerization modifications to polycarbonate polymers via a flow reactor are provided. For example, one or more embodiments described herein can comprise a cyclic carbonate monomer that can be employed to facilitate polymerization of one or more polycarbonate platforms susceptible to post polymerization modification. For instance, one or more embodiments can regard a cyclic carbonate molecular backbone covalently bonded to an aryl halide functional group via in accordance with a chemical structure selected from the group consisting of:

##STR00001##

In the chemical structures, “R.sub.1” can be selected from the group consisting of a hydrogen atom and a functional group comprising a first alkyl group; “L” can represent a linkage group, comprising: a second alkyl group and an end group having at least one member selected from the group consisting of an oxygen atom and a nitrogen atom; and “A” can represent the aryl halide functional group.

A copolycarbonate includes 0.005-0.1 mole percent of sulfur-containing carbonate units derived from a sulfur-containing bisphenol monomer, 2-95 mole percent of high heat carbonate units derived from a high heat aromatic dihydroxy monomer, and 5-98 mole percent of a low heat carbonate units derived from a low heat aromatic monomer, each based on the sum of the moles of the carbonate units; and optionally, thioether carbonyl endcaps of the formula —C(═O)-L-S—R, wherein L is a C.sub.1-12 aliphatic or aromatic linking group and R is a C.sub.1-20 alkyl, C.sub.6-18 aryl, or C.sub.7-24 arylalkylene; wherein the sulfur content of the high heat copolycarbonate in the absence of the thioether endcaps is from 5-20 parts per million by weight.

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.

Provided is a polycarbonate resin which maintains favorable properties as an optical material while having fluidity suitable for molding. Furthermore, provided are an optical lens and an optical film that use the polycarbonate resin. The polycarbonate resin is characterized by comprising a component unit (A) expressed by general formula (1) and a component unit (B) expressed by general formula (2).

##STR00001##

##STR00002##

Provided is a polycarbonate resin which maintains favorable properties as an optical material while having fluidity suitable for molding. Furthermore, provided are an optical lens and an optical film that use the polycarbonate resin. The polycarbonate resin is characterized by comprising a component unit (A) expressed by general formula (1) and a component unit (B) expressed by general formula (2).

##STR00001##

##STR00002##

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.

The present invention relates to a production method of polyalkylene carbonate particles capable of precipitating and separating resin particles from a polyalkylene carbonate suspension obtained through polymerization of an epoxide and carbon dioxide. According to the present invention, the production method is capable of obtaining a polyalkylene carbonate resin having excellent workability with a high yield and a low energy cost while reducing a scale of a facility, a processing time, and a wastewater amount, as compared to conventional methods such as a flash separation method.