Provided are a novel compound having a fluorene skeleton, and a method for manufacturing the same, the compound having a low palladium content or other content of a specific metal or content of a specific compound in a raw material alcohol, and being excellent in hue or various characteristics (optical characteristics, heat resistance, moldability, and other characteristics) as a raw material or in a resin that uses the raw material. This compound is a mixture of compounds having a fluorene skeleton represented by formula (1) (in formula (1), the rings Z being (same or different) aromatic groups, R.sup.1 and R.sup.2 each independently representing a hydrogen atom, a halogen atom, or a C1-12 hydrocarbon group which may include an aromatic group, Ar.sup.1 and Ar.sup.2 representing C6-10 aromatic groups which may have a substituent, L.sup.1 and L.sup.2 representing alkylene groups, j and k each independently representing an integer of 0 or greater, and m and n each independently representing an integer of 0 to 5), the mixture of compounds having a fluorene skeleton being characterized in that the content of elemental palladium therein satisfies formula (2) ((2): 0≤Pd≤50 ppm), and among the mixture of compounds represented by formula (1), compounds comprising the integers m=1-5 and n=0 are included in a range of 0-5%.

The invention provides an optical lens that can provide small-sized imaging modules. The optical lens of the invention comprises a thermoplastic resin having a refractive index (nD) and Abbe number (ν) satisfying the following mathematical formula (A):

nD≤−0.02×ν+2.040  (A)

(where 1.660<nD).

Provided is an aromatic polycarbonate resin that has not only high fluidity and thin-wall moldability but also excellent hue and transparency. The aromatic polycarbonate resin contains a structural unit derived from an aromatic dihydroxy compound and a carbonate-forming compound. A hydrolysate obtained by hydrolysis of the aromatic polycarbonate resin contains aromatic dihydroxy compounds represented by the following Formulae (2) and (3), and the content of the compound represented by Formula (2) is 250 ppm by mass or less with respect to that of the compound represented by Formula (3), wherein R.sub.1 represents an alkyl group having 1 to 24 carbon atoms; R.sub.2 and R.sub.3 each independently represent a monovalent hydrocarbon group having 1 to 15 carbon atoms; and a and b each independently represent an integer of 0 to 4: ##STR00001##

Provided is an aromatic polycarbonate resin that has not only high fluidity and thin-wall moldability but also excellent hue and transparency. The aromatic polycarbonate resin contains a structural unit derived from an aromatic dihydroxy compound and a carbonate-forming compound. A hydrolysate obtained by hydrolysis of the aromatic polycarbonate resin contains aromatic dihydroxy compounds represented by the following Formulae (2) and (3), and the content of the compound represented by Formula (2) is 250 ppm by mass or less with respect to that of the compound represented by Formula (3), wherein R.sub.1 represents an alkyl group having 1 to 24 carbon atoms; R.sub.2 and R.sub.3 each independently represent a monovalent hydrocarbon group having 1 to 15 carbon atoms; and a and b each independently represent an integer of 0 to 4: ##STR00001##

A polycarbonate resin composition or a copolymer, comprising, as main repeating units, a carbonate unit (a-1) having a fluorene ring in a side chain, a carbonate unit (a-2) represented by the following formula (a-2):

##STR00001##

(wherein W represents an alkylene group having 1 to 20 carbon atoms or a cycloalkylene group having 6 to 20 carbon atoms, R represents a branched or linear-chain alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 6 to 20 carbon atoms optionally having a substituent, and u represents an integer of 0 to 3), and a carbonate unit (a-3) derived from 2,2-bis(4-hydroxyphenyl)propane, wherein 1) a molar ratio of the carbonate unit (a-1) to the carbonate unit (a-2) is from 50/50 to 80/20, and 2) a molar ratio of the total of the carbonate unit (a-1) and the carbonate unit (a-2) to the carbonate unit (a-3) is from 1:99 to 70:30. This polycarbonate resin composition or copolymer has excellent heat resistance, transparency, and bending resistance and has low retardation.

A polycarbonate diol containing a repeating unit represented by the specific formula (A) and a terminal hydroxyl group, wherein more than 0 mol % and not more than 3.0 mol % of the terminals thereof is an oxolane terminal represented by the specific formula (B).

The object of the invention is to provide a shoe press belt which has an excellent strength while the variation in strength among its parts being suppressed, and to provide a method for producing such a shoe press belt. Provided is a shoe press belt for use in a papermaking machine comprising at least one resin layer, wherein the resin layer comprises a polyurethane resin formed by curing an urethane prepolymer having an isocyanate group with a curing agent having an active hydrogen group, wherein the curing agent comprises one or more polycarbonate diol(s) expressed by the following formulae (1) and (2).
HO-A.sub.m-B.sub.n—R.sup.1OH  (1) ##STR00001##

A method of preparing a polycarbonate composition, including: melt polymerizing in a polymerization unit a dihydroxy compound with a diaryl carbonate and removing a stream of color inducing species containing an isopropenyl phenyl-containing group from the polymerization unit, to form a polycarbonate composition, wherein the polycarbonate has a color inducing species containing an isopropenyl phenyl-containing group level below 170 ppm is provided.

The present invention relates to triarylmethane compounds of the formula (I), which suitable as monomers for preparing thermoplastic resins having beneficial optical properties and which can be used for producing optical devices. R.sup.1, R.sup.2 are e.g. hydrogen; Y is an alkylene group having 2, 3 or 4 carbon atoms, Ar is selected from mono- or polycyclic aryl and mono- or polycyclic hetaryl; X.sup.1, X.sup.2, X.sup.3, X.sup.4 are CH, C—R.sup.x or N, provided that in each ring at most two of X.sup.1, X.sup.2, X.sup.3, X.sup.4 are N; R.sup.x is e.g. halogen, CN or CH═CH.sub.2. The invention also relates to thermoplastic resins comprising a polymerized unit of the compound of formula (I). ##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.