Patent
Production of aromatic polycarbonate
Reads0
Chats0
TLDR
In this article, a salicylic ester and chloroformic ester are subjected to a coupling reaction in the presence of a basic compound to form a crude sicylic eater derivative represented by the formula (wherein R 1 is methyl or ethyl; X is a 1-30C alkyl, a 1 -30C alkoxyl, a 6-30 C aryl or the like).Abstract:
PROBLEM TO BE SOLVED: To obtain an aromatic polycarbonate while reducing material cost by recovering the salicylic ester formed as a result of a termination reaction using a salicylic ester derivative or of a polymerization acceleration reaction and using the salicylic ester derivative produced from the recovered product again. SOLUTION: A salicylic ester and chloroformic ester are subjected to a coupling reaction in the presence of a basic compound to form a crude salicylic eater derivative represented by the formula (wherein R 1 is methyl or ethyl; X is a 1-30C alkyl, a 1-30C alkoxyl, a 6-30C aryl or the like), and this crude product is purified to a chlorine content of 1,000 ppm or below and an alkali metal content of 10 ppm or below. An aromatic dihydroxy compound and a carbonic diester are polycondensed in a molten state to form a prepolymer, the salicylic ester derivative as a terminating agent is added to the system and reacted. The salicylic ester is distilled out to form an aromatic polycarbonate. The distilled salicylic ester is recovered and is used to synthesize a salicylic ester derivative. This derivative is used again as a terminating agent. COPYRIGHT: (C)1998,JPOread more
Citations
More filters
Patent
Polyester Compositions Containing Cyclobutanediol Having a Certain Combination of Inherent Viscosity and Moderate Glass Transition Temperature and Articles Made Therefrom
Emmett Dudley Crawford,Thomas Joseph Pecorini,Douglas Stephens Mcwilliams,David Scott Porter,Gary Wayne Connell +4 more
TL;DR: In this article, polyester compositions comprising at least one polyester which comprises terephthalic acid residues, 2,2,4,4tetramethyl-1,3-cyclobutanediol, and 1,4-cyclohexanedimethanol, wherein the inherent viscosity and the Tg of the polyester provides for certain polyester properties.
Patent
A method for manufacturing polycarbonate
TL;DR: In this article, a method for manufacturing polycarbonate with excellent dwell stability (e.g., thermal stability and hue stability) during melting and molding, as well as with a low content of impurities was presented.
Patent
Process for producing aromatic polycarbonate
TL;DR: In this article, a method for handling the by-product phenol yielded in a PC production step is presented. But the method is restricted to a value in a given range, and the water content of the phenol is regulated.
Patent
Aromatic polycarbonate resin composition
Yoshihide Teijin Chemicals Ltd. Hashimoto,Tetsuya Teijin Chemicals Ltd. Aibara,Tomomitsu Teijin Chemicals Ltd. Onizawa +2 more
TL;DR: In this article, an aromatic polycarbonate resin composition having a high molecular weight and less amount of a heterologous structure, retaining good qualities, and excellent in thermal stability, and an improved preparation process thereof.
Patent
Process for producing aromatic polycarbonate
TL;DR: In this paper, an aromatic polycarbonate is subjected to transesterification with an active-hydrogen compound in the presence of a Transesterification catalyst under vacuum conditions, and the reaction product is reacted with a salicylic ester derivative represented by formula (1), wherein X represents methyl or ethyl; and Y represents carbonyl or a divalent functional group represented by (2), wherein Z represents C1-30 alkylene, C6-30 arylene, or C7-30 aralkylene.
References
More filters
Patent
Production of polycarbonate
TL;DR: In this paper, the subject polymer is obtained by dispersing a bisphenol alkali metallic salt hydrate in an organic solvent, phosgenating the resultant dispersion in an anhydrous system, then adding an aqueous medium thereto, dissolving the resultant alkali chloride therein and carrying out polycondensation.
Patent
Rolling mill for shape steel
TL;DR: In this paper, the edger through guide is divided into a front part and a rear part when a shape steel having a web and flange is rolled by a universal mill and an edger mill.