Abstract: A light control plastic lens, a sheet-like light control element, and a production method for light control plastic lenses are provided. More specifically, a light control plastic lens, such as a high index polarizing property and/or a photochromic plastic lens that is made by cast polymerization is provided. Also provided is a sheet-like light control element for use in the production of the lenses, as well as a production method of such light control plastic lenses. The light control plastic lens has a sheet-like light control element including at least a light control sheet. In particular, the light control plastic lens has a sheet-like light control element, a curable resin layer laminated on at least one surface of the sheet-like light control element, and a polymerizable lens resin layer laminated at least on the curable resin layer.

Abstract: A light control plastic lens, a sheet-like light control element, and a production method for light control plastic lenses are provided. More specifically, a light control plastic lens, such as a high index polarizing property and/or a photochromic plastic lens that is made by cast polymerization is provided. Also provided are a sheet-like light control element for use in the production of the lenses, as well as a production method of such light control plastic lenses. The light control plastic lens has a sheet-like light control element including at least a light control sheet. In particular, the light control plast lens the sheet-like light control element, a curable resin layer laminated on at least one surface of the sheet-like light control element, and a polymerizable lens resin layer laminated at least on the curable resin layer.

Abstract: A polycarbonate resin obtainable by reaction of a carbonic acid ester-forming compound with bisphenols consisting essentially of 9,9-bis(4-hydroxy-3-methylphenyl) fluorene and a bisphenol compound(s) having a polysiloxane skeleton, an intrinsic viscosity of said polycarbonate resin being 0.2 to 2.0 dl/g.

Abstract: A polycarbonate resin obtainable by reaction of a carbonic acid ester-forming compound with bisphenols consisting essentially of 9,9-bis (4-hydroxy-3-methylphenyl) fluorene and a bisphenol compound(s) having a polysiloxane skeleton, an intrinsic viscosity of said polycarbonate resin being 0.2 to 2.0 dl/g.

Abstract: A branched polycarbonate resin having a viscosity average molecular weight (Mv) of 15,000 to 45,000, number of dichloromethane insoluble gel like particle with a particle diameter more than 50 &mgr;m being 10 or below per 100 g of the resin, obtained by reacting bisphenol, trihydric or above phenol as branching agent, monohydric phenol as molecular weight modifier and phosgene in the presence of both an alkali aqueous solution and organic solvent to polymerize and a process for producing the same.

Abstract: A process for preparing a polycarbonate which comprises performing a transesterification and a polycondensation reaction with a diarylcarbonate and dihydroxyaryl compound, in a reaction apparatus composed of stainless steel comprising at least 12% by weight of Ni, and at least 22% by weight of Cr, and having Fe as the remaining main component. A polycarbonate which has a good color, is stable to hydrolysis and resistant to heat-yellowing is the resulting product.

Abstract: A polycarbonate resin composition for radiation sterilization, comprising an aromatic polycarbonate resin having structural units derived from a halogenated bisphenol, and a polyalkylene compound selected from poly(alkylene glycol), its ether, silyl ether or ester. Molded articles produced from the composition do not substantially undergo yellowing when exposed to radiation in air or under a substantially oxygen-free atmosphere, and can be advantageously employed in medical appliances.

Abstract: A polycarbonate resin comprising either a structural unit derived from a spiro ring-containing dihydric phenol, or such a structural unit and a structural unit derived from a dihydric phenol, and a process for producing the same. The polycarbonate resin has excellent flowability and moldability, and also improved optical properties (low refractive index, large Abbe number, etc.), and can be advantageously used in various fields, e.g., as a material for molded articles for optical use and other precision molded articles.

Abstract: A process for producing a weather-resistant polycarbonate resin by solution polymerization, of at least one dihydric phenol and phosgene in which a compound represented by formula (I): ##STR1## wherein R.sup.1, R.sup.2, and R.sup.3, each represents a hydrogen atom, a halogen atom, a nitro group, an alkyl group having from 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, or an aryl group having from 6 to 20 carbon atoms; m represents 1 or 2; and n represents an integer of from 1 to 10, is used as a terminator. The polycarbonate resin produced exhibits high weather resistance without suffering from volatilization.

Abstract: This invention provides 2,2-bis[4-(4'-hydroxybenzoyloxy)cyclohexyl]propane represented by the formula: ##STR1## a process for preparing the above compound by a transesterification reaction of 2,2-bis(4-hydroxycyclohexyl)propane with alkyl 4-hydroxybenzoate.