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 provides a stretched film exhibiting excellent reverse wavelength dispersibility, a circularly polarizing plate, and a display device. The stretched film of an embodiment of the present invention is a stretched film having a slow axis in an in-plane direction, in which the stretched film satisfies a relationship of Formula (A) Re(450)/Re(550)<1.00, and an absorption at a wavelength of 700 to 900 nm in a fast axis direction of the stretched film is larger than an absorption at a wavelength of 700 to 900 nm in a slow axis direction of the stretched film. In Formula (A) Re(450) represents an in-plane retardation of the stretched film at a wavelength of 450 nm and Re(550) represents an in-plane retardation of the stretched film at a wavelength of 550 nm.

The present invention relates to compounds of the formula (I), which are suitable as monomers for preparing thermoplastic resins having beneficial optical properties and which can be used for producing optical devices: where A.sup.1, A.sup.2 are selected from mono- or bicyclic aromatic radicals and mono- or bicyclic heteroaromatic radicals, X represents e.g. a single bond, O, NH, CR.sup.6R.sup.7, Y is e.g. absent or represents a single bond, O, NH, CR.sup.8R.sup.9; R.sup.1, R.sup.2 are hydrogen, a radical Ar′ or a radical R.sup.a; R.sup.3 is Alk, O-Alk′-, O-Alk′-[O-Alk′].sub.0, O—CH.sub.2—Ar—C(O)—, O—C(O)—Ar—C(O)— or O-Alk-C(O)—, where in the last five moieties the left O is bound to A.sup.1 and A.sup.2, respectively, m, n are 0, 1 or 2; o is an integer from 1 to 10; R.sup.4, R.sup.5 are e.g. selected from CN and a radical R.sup.a; R.sup.6, R.sup.8 are e.g. selected from hydrogen, a radical Ar′ and a radical R.sup.a; R.sup.7, R.sup.9 are e.g. selected from hydrogen, C.sub.1-C.sub.4-alkyl and a radical Ar′; R.sup.a is selected from the group consisting of C≡C—R.sup.11 and Ar—C≡C—R.sup.11; R.sup.11 is e.g. selected from hydrogen, methyl, mono- or polycyclic aryl having from 6 to 26 carbon atoms and mono- or polycyclic hetaryl having a total of 5 to 26 atoms, which are ring members, where 1, 2, 3 or 4 of the ring atoms of hetaryl are selected from nitrogen, sulphur and oxygen, while the remainder of these atoms are carbon atoms, where mono- or polycyclic aryl are unsubstituted or substituted; and Ar is e.g. phenylene or naphthylene. The invention also relates to thermoplastic resins comprising a polymerized unit of the compound of formula (I) and to optical devices made of such resins.

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Provided is a synthesis method comprising a first step of producing a carbonate compound from carbon monoxide and an alcohol-based compound at an anode of a first electrochemical cell comprising a cathode and the anode, and a second step of synthesizing a first product by a dealcoholization reaction of the carbonate compound, wherein an alcohol-based compound eliminated in the second step is recycled in the first step.

A copolycarbonate optical article comprises a polycarbonate composition including: a copolycarbonate having: 2 to 60 mol % of phthalimidine carbonate units, 2 to 90 mol % of high heat carbonate units, and optionally 2 to 60 mol % of bisphenol A carbonate units. The copolycarbonate has less than 100 ppm of each of phthalimidine, high heat bisphenol, and bisphenol A monomers, and less than 5 ppm of various ions, and is prepared from monomers each having a purity of at least 99.6%. The polycarbonate composition has a glass transition temperature of 200° C. to and a yellowness index of less than 30.

The present invention relates to an aromatic polycarbonate obtained via the melt transesterification of a diaryl carbonate, a bisphenol and an endcapping agent selected from paracumyl phenol, dicumyl phenol, p-tert-butyl phenol and mixtures of at least two of said endcapping agents, said polycarbonate having a melt volume rate of at least 20 cm.sup.3/10 min (ISO 1133, 300° C., 1.2 kg), a terminal hydroxyl group content of at most 800 ppm by weight, a Fries branching content of at most 1300 ppm by weight and a content of bulky end groups of at least 20 mol % defined as the sum of the mol % of end-groups based on said bisphenol and the mol % of end-groups based on said endcapping agent.

The present invention relates to a method for the continuous multi-stage manufacture of an end-capped polycarbonate comprising, i) preparing a monomer mixture in a monomer mixing stage by mixing a bisphenol, a diaryl carbonate and optionally a transesterification catalyst in at least one monomer mixing device, ii) preparing a carbonate oligomer in an oligomerisation stage by reacting said monomer mixture in at least one oligomerisation reactor, iii) preparing the polycarbonate in a polymerisation stage by further reacting the carbonate oligomer of the oligomerisation stage in at least one polymerisation reactor, wherein an end-capping agent different from phenol and having a single phenolic hydroxy group is added to the monomer mixture in the monomer mixing stage and/or to at least one oligomerisation reactor in the oligomerisation stage.

Provided is an aromatic polycarbonate resin composition that exhibits an excellent surface hardness and strength as well as an excellent designability and lightfastness. The aromatic polycarbonate resin composition contains a carbonate structural unit (X) derived from an aromatic dihydroxy compound represented by a prescribed formula (1) and a carbonate structural unit (Y) derived from an aromatic dihydroxy compound represented by a prescribed formula (2) in a proportion of (X)/(Y)=10/90 to 40/60 as a molar ratio, wherein an amount of a cresolic hydroxy group derived from the aromatic dihydroxy compound represented by formula (1) is 60 to 160 ppm.

The objective of the present invention is to provide a method for producing a fluorinated carbonate derivative in a safe and efficient manner. The method for producing a fluorinated carbonate derivative according to the present invention is characterized in comprising irradiating light on a composition containing a C.sub.1-4 halogenated hydrocarbon having one or more kinds of halogen atoms selected from the group consisting of a chlorine atom, a bromine atom and an iodine atom, a fluorine-containing compound having a nucleophilic functional group and a base in the presence of oxygen.

The present invention relates to compounds of the formula (I), which are suitable as monomers for preparing thermoplastic resins having beneficial optical properties and which can be used for producing optical devices. In Formula (I), A.sup.1, A.sup.2 are selected from mono- or bicyclic aromatic radicals and mono- or bicyclic heteroaromatic radicals; X represents e.g. a single bond, O, NH, CR.sup.6R.sup.7; Y is e.g. absent or represents a single bond, O, NH, CR.sup.8R.sup.9; R.sup.1, R.sup.2 are hydrogen, a radical Ar′ or a radical R.sup.a; R.sup.3 is Alk, O-Alk′-, O-Alk′-[O-Alk′].sub.o, O—CH.sub.2—Ar—C(O)—, O—C(O)—Ar—C(O)— or O-Alk-C(O)—, where in the last five moieties the left O is bound to A.sup.1 and A.sup.2, respectively; m, n are 0, 1 or 2; o is an integer from 1 to 10; R.sup.4, R.sup.5 are e.g. selected from CN and a radical R.sup.a; R.sup.6, R.sup.8 are e.g. selected from hydrogen, a radical Ar′ and a radical R.sup.a; R.sup.7, R.sup.9 are e.g. selected from hydrogen, C.sub.1-C.sub.4-alkyl and a radical Ar′; R.sup.a is selected from the group consisting of C≡C—R.sup.11 and Ar—C≡C—R.sup.11; R.sup.11 is e.g. selected from hydrogen, methyl, mono- or polycyclic aryl having from 6 to 26 carbon atoms and mono- or polycyclic hetaryl having a total of 5 to 26 atoms, which are ring members, where 1, 2, 3 or 4 of the ring atoms of hetaryl are selected from nitrogen, sulphur and oxygen, while the remainder of these atoms are carbon atoms, where mono- or polycyclic aryl are unsubstituted or substituted; and Ar is e.g. phenylene or naphthylene. The invention also relates to thermoplastic resins comprising a polymerized unit of the compound of formula (I) and to optical devices made of such resins.

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