摘要:
The method of the present invention is a hot-melt polycondensation for an aromatic dihydroxy compound and a dicarbonate in the presence of a basic catalyst, adding sulfur-containing acid compound with a pKa value less than 3 or the derivative thereof, and 5-1,000 ppm of water, and additives as needed for the polycarbonate while the reaction product polycarbonate is still in a molten state, and kneading the material.
摘要:
The present invention relates to a method for preparing copolymeric polycarbonates which comprises melt polycondensing a mixture of an aromatic dihydroxy compound containing an amount of 2-90 mol % of hydroquinone or substituted hydroquinones and a diester carbonate in the presence of a catalyst containing an alkali metal compound or an alkaline earth metal compound in an amount of 1.times.10.sup.-8 to 5.times.10.sup.-6 mole per mole of the total amount of the aromatic dihydroxy compound, then adding an acidic compound to the melt polycondensation product.
摘要:
The present invention provides copolymerized polycarbonates having improved flow and formability, in addition to excellent mechanical properties, heat resistance, transparency, and water resistance obtained by copolymerization of two or more aromatic dihydroxy compounds and a compound capable of reacting with those aromatic dihydroxy compounds to form carbonate linkages, characterized in that, of all the constituent repeating units derived from aromatic dihydroxy compounds, 2-40 mole % are derived from resorcin and/or substituted resorcins.
摘要:
A copolymeric polycarbonate containing repeating constituent units having formula [I] below and repeating constituent units having formula [II] below in a molar ratio of from 98:2 to 40:60. ##STR1## The above-described copolymeric polycarbonates have excellent resistance to chemicals, heat resistance and flame retardancy without compromising the impact resistance and good hues intrinsic to polycarbonates.
摘要:
Object: The present invention was conceived in light of the above-described prior art. The object of this invention is to provide a method for preparing optical-grade polycarbonate compositions, which method is able to prepare with good productivity optical-grade polycarbonate compositions that have not only excellent clarity and water resistance, but also excellent retention stability such as heat stability and hue stability when molten and a low content of inclusions and impurities, and that undergo little heat deterioration.Constitution: The method for preparing optical-grade polycarbonate compositions according to this invention, which method comprises the melt-polycondensation of an aromatic dihydroxy compound and a diester carbonate in the presence of a catalyst, followed by the addition of additives [B] while the polycarbonate [A] obtained as the reaction product is in a molten state, and mixing.In this invention, it is preferable to prepare the optical-grade polycarbonate composition by filtration with a polymer filter following mixing.
摘要:
The present invention relates to a polycarbonate production method. More specifically, it relates to a polycarbonate production method that is capable of preparing polycarbonates which have excellent residence stability such as hue stability and heat stability at the time of molding, and which have particularly outstanding water resistance.
摘要:
Disclosed herein are processes for the production of polycarbonates by melt polycondensation of an aromatic dihydroxy compound and a carbonic acid diester or a diphenyl carbonate compound wherein said polycondensation is carried out in the presence of from 0.05 to 15 mol %, based on 1 mole of the aromatic dihydroxy compound, of a phenol having from 10 to 40 carbon atoms, a carbonic acid diester having from 17 to 50 carbon atoms, or a carbonic acid diester having from 13 to 16 carbon atoms, using a catalyst comprising (a) a nitrogen containing basic compound, (b) from 10.sup.-8 to 10.sup.-3 mole, based on 1 mole of the aromatic dihydroxy compound, of an alkali metal or alkaline earth metal compound, and (c) boric acid or boric ester. Also disclosed is a polycarbonate in which from 5 to 30% of its terminal groups are hydroxy groups and it has a sodium content of not more than 1 ppm and a chlorine content of not more than 20 ppm.
摘要:
Hydrophilic gelled crosslinked polymers comprising as an essential constituent monomer component a (meth)acrylate ester monomer having a fluorine-substituted hydrocarbon group containing at least three fluorine atoms grafted thereto. The fluorine-containing polymers have excellent oxygen permeability, water swellability, wearing comfort and contamination resistance.
摘要:
Hydrophilic gelled crosslinked polymers comprising as an essential constituent monomer component a (meth)acrylate ester monomer having a fluorine-substituted hydrocarbon group containing at least three fluorine atoms grafted thereto. The fluorine-containing polymers have excellent oxygen permeability, water swellability, wearing comfort and contamination resistance.
摘要:
To provide a method with which a polycarbonate can be manufactured efficiently without any pipe clogging or foreign material admixture in the course of the continuous manufacture of a polycarbonate. A continuous method for manufacturing a polycarbonate, characterized in that, in the continuous manufacture of a polycarbonate by transesterification from a dihydroxy compound and a carbonic diester, the crystallization of a polycarbonate lower polycondensate produced in the intermediate stage of a polycondensation reaction whose intrinsic viscosity (IV) measured at 20° C. in methylene chloride is between 0.1 and 0.4 dL/g is suppressed by setting the temperature to be at least 230° C. on the surface of the reactor equipment in contact with the polycarbonate lower polycondensate.
摘要翻译:提供一种在连续制造聚碳酸酯的过程中可以有效地制造聚碳酸酯而没有任何管堵塞或异物混合的方法。一种用于制造聚碳酸酯的连续方法,其特征在于,在连续制造聚碳酸酯 通过二羟基化合物和碳酸二酯的酯交换反应,在二氯甲烷中在20℃下测定的特性粘度(Ⅳ)在二氯甲烷中的缩聚反应的中间阶段产生的聚碳酸酯低缩聚物的结晶为0.1〜0.4dL / g 通过在与聚碳酸酯低缩聚物接触的反应器设备的表面上设定温度至少为230℃来抑制。