Abstract: A polycarbonate copolymer contains: 0.1 to 50 mol % of a monomer unit represented by the following formula (1); and a monomer unit represented by the following formula (2). In the polycarbonate copolymer, the content of biphenols having a structure represented by the following formula (3) is 90 mass ppm or less. In the formula, R1 and R2 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a halogen atom. In the formula: R3 and R4 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a halogen atom; and X represents any one of bonding groups represented by —O—, —S—, —SO—, —SO2—, —CO— and 9,9-fluorenylidene group. In the formula, R1 and R2 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a halogen atom.

Abstract: A polycarbonate copolymer contains: 0.1 to 50 mol % of a monomer unit represented by the following formula (1); and a monomer unit represented by the following formula (2). In the polycarbonate copolymer, the content of biphenols having a structure represented by the following formula (3) is 90 mass ppm or less. In the formula, R1 and R2 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a halogen atom. In the formula: R3 and R4 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a halogen atom; and X represents any one of bonding groups represented by —O—, —S—, SO—, —SO2—, —CO— and 9,9-fluorenylidene group. In the formula, R1 and R2 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a halogen atom.

Abstract: A polycarbonate polymer includes: a monomer unit represented by a formula (1A) below; and a monomer unit represented by a formula (2). A haze of a solution that is obtained by dissolving the polycarbonate polymer in THF (tetrahydrofuran) at a concentration of 10 mass % is 5% or less (according to JIS K7105, optical path length of 10 mm). In the formula (1A), R and R? each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms; n1 is an integer in a range of 2 to 4; and n2 is an integer in a range of 25 to 220; and in the formula (2), Ar represents a divalent aromatic group.

Abstract: A polycarbonate copolymer contains: 0.1 to 50 mol % of a monomer unit represented by the following formula (1); and a monomer unit represented by the following formula (2). In the polycarbonate copolymer, the content of biphenols having a structure represented by the following formula (3) is 90 mass ppm or less. In the formula, R1 and R2 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a halogen atom. In the formula: R3 and R4 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a halogen atom; and X represents any one of bonding groups represented by —O—, —S—, —SO—, —SO2—, —CO— and 9,9-fluorenylidene group. In the formula, R1 and R2 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a halogen atom.

Abstract: Provided is an electrophotographic photosensitive body having a photosensitive layer on a conductive base, in which at least the outermost layer thereof contains particles having a double structure composed of a core member and a shell member having a lager rubber hardness than the core member. The electrophotographic photosensitive body has excellent mechanical strength such as wear resistance, abrasion resistance, and scratch resistance as well as excellent electrophotographic characteristics such as cleaning property for a long time period.

Abstract: Provided are a polycarbonate resin which can solve problems present in an electrophotographic photoreceptor and an electrophotographic photoreceptor in which the above polycarbonate resin is used and which is improved in a cleaning property, a lubricity and an abrasion resistance. The polycarbonate resin comprises a repetitive unit represented by the following Formula (1), and the electrophotographic photoreceptor in which a photosensitive layer is provided on a conductive substrate contains the above polycarbonate resin in the above photosensitive layer. In the following Formula (1), R represents an alkyl group having 1 to 3 carbon atoms; n1 is an integer of 2 to 4; and n2 is an integer of 1 to 200.

Abstract: The present invention provides a polythiocarbonate resin containing a repeating unit represented by the following general formula (1), having high transparency, refractive index, and Abbe number and excellent heat resistance and impact resistance, and an optical material using the polythiocarbonate resin. Further, the present invention provides a sulfur-containing compound having an Abbe number of 40 or more, a high refractive index, a high Abbe number, excellent transparency, excellent heat resistance, and the like, obtained by reacting a dithiol compound represented by the following general formula (II) and a diene compound represented by the following general formula (III), and thus containing a repeating unit formed of a structural unit derived from a residue of the dithiol compound and a structural unit derived from a residue of the diene compound.

Abstract: Provided are a polycarbonate resin which can solve problems present in an electrophotographic photoreceptor and an electrophotographic photoreceptor in which the above polycarbonate resin is used and which is improved in a cleaning property, a lubricity and an abrasion resistance. The polycarbonate resin comprises a repetitive unit represented by the following Formula (1), and the electrophotographic photoreceptor in which a photosensitive layer is provided on a conductive substrate contains the above polycarbonate resin in the above photosensitive layer. In the following Formula (1), R represents an alkyl group having 1 to 3 carbon atoms; n1 is an integer of 2 to 4; and n2 is an integer of 1 to 200.

Abstract: An electrostatic image developing toner comprising at least a binder resin and a releasant, wherein the binder resin comprises a petroleum resin and a styrene-based copolymer or styrene-based homopolymer in an amount of 5:5 to 7:3 by weight in terms of the ratio of the petroleum resin:styrene-based copolymer or styrene-based homopolymer and has the maximum molecular weight value (PL) based on the petroleum resin in a range of from 5×102 to 2×103 and the maximum molecular weight value (PH) based on the styrene-based copolymer or styrene-based homopolymer in a range of from 1×105 to 4.5×105 in the chromatogram obtained by measuring the binder resin through gel permeation chromatography and the releasant is a wax having a melt viscosity at 140° C. of 102 mPa/s (cp) or less and is added in an amount of 1 to 7 parts by weight per 100 parts by weight of the toner.

Abstract: An electrostatic image developing toner comprising at least a binder resin and a releasant, wherein the binder resin comprises a petroleum resin and a styrene-based copolymer or styrene-based homopolymer in an amount of 5:5 to 7:3 by weight in terms of the ratio of the petroleum resin:styrene-based copolymer or styrene-based homopolymer and has the maximum molecular weight value (PL) based on the petroleum resin in a range of from 5×102 to 2×103 and the maximum molecular weight value (PH) based on the styrene-based copolymer or styrene-based homopolymer in a range of from 1×105 to 4.5×105 in the chromatogram obtained by measuring the binder resin through gel permeation chromatography and the releasant is a wax having a melt viscosity at 140° C. of 102 mPa/s (cp) or less and is added in an amount of 1 to 7 parts by weight per 100 parts by weight of the toner.

Abstract: The invention is [1] a resin composition comprising a resin obtained by polymerizing cyclopentadiene or the like and a specific styrene resin, [2] a resin composition comprising (a) a polystyrene-type polymer component and (b) a specific petroleum resin-based polymer component, and [3] a toner binder resin for development of an electrostatically charged image comprising (A) a terpene resin or the like and (B) a styrene resin and/or a polyester resin. Further, it is a toner binder resin for development of an electrostatically charged image containing these resin compositions as a main component, and a toner for development of an electrostatically charged image comprising the toner binder resin and a coloring material.

Abstract: The invention is [1] a resin composition comprising a resin obtained by polymerizing cyclopentadiene or the like and a specific styrene resin, [2] a resin composition comprising (a) a polystyrene-type polymer component and (b) a specific petroleum resin-based polymer component, and [3] a toner binder resin for development of an electrostatically charged image comprising (A) a terpene resin or the like and (B) a styrene resin and/or a polyester resin. Further, it is a toner binder resin for development of an electrostatically charged image containing these resin compositions as a main component, and a toner for development of an electrostatically charged image comprising the toner binder resin and a coloring material.

Abstract: A polycarbonate containing repeating units (1) represented by the general formula (1), a polycarbonate molding produced by molding the polycarbonate, and an electrophotographic photoreceptor having a photosensitive layer which has a surface layer containing the polycarbonate: ##STR1## wherein R is an aliphatic unsaturation-free monovalent hydrocarbon group, R.sup.1 is a halogen atom, an alkyl group, an alkoxy group or an aryl group, X is an alkylene group or an alkyleneoxyalkylene group, X' is an alkylene group of 2 or more carbon atoms, an alkyleneoxyalkylene group or oxygen atom, a is an integer of 0 to 4, na is 0 or 1, nb is 1 or 2, nc is 1 or 2, provided na+nb+nc=3, n1, n2, n3 and n4 are 0 or an integer of 1 or more, provided n1+n2+n3+n4 is an integer of 0 to 450.

Abstract: A polycarbonate resin having crosslinking groups selected from among the functional groups mentioned above in the side chains, ends or main chain; a crosslinked polycarbonate resin made from the above resin through crosslinking; and an electrophotographic photoreceptor containing such a resin in its photosensitive layer. In said groups, h is an integer of 0 to 4, R.sup.7 and R.sup.8 are each hydrogen, alkyl or aryl; X', Y' and Z' are each a single bond, --O--, --CO--, --S--, --SO--, --SO.sub.2 -- or alkylene; R.sup.20 and R.sup.21 are each hydrogen, alkyl, cycloalkyl or aryl; R.sup.19 and R.sup.22 are each hydrogen, alkyl, cycloalkyl or aryl; R.sup.23 and R.sup.24 are each hydrogen, halogeno, alkyl, cycloalkyl, alkoxy or aryl; the sum of p and q is an integer of 1 or above; R.sup.25, R.sup.26, R.sup.27 and R.sup.