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    • 4. 发明授权
    • Method for conducting solid state polymerization of polycarbonates
    • 聚碳酸酯的固态聚合方法
    • US06248858B1
    • 2001-06-19
    • US09192350
    • 1998-11-16
    • James DayGodavarthi Satyana Varadarajan
    • James DayGodavarthi Satyana Varadarajan
    • C08G6400
    • C08G64/20C08G63/64C08G64/40
    • Polymerization of polycarbonates is performed by first enhancing the crystallinity of a precursor polycarbonate, such as an oligomer, by contact in pellet form with an alkanol in the liquid or vapor state as non-solvent, and then conducting solid state polymerization in a stream of inert gas such as nitrogen. The solid state polymerization operation includes a stage of heating at a constant temperature in the range of about 215-225° C., optionally combined with a first heating stage at a constant temperature in the range of about 180-190° C. The method is adaptable to continuous operation and produces a polycarbonate having a number average molecular weight, as determined by gel permeation chromatography relative to polystyrene, of at least 15,000.
    • 聚碳酸酯的聚合通过首先通过以颗粒形式与液体或蒸气状态的链烷醇作为非溶剂接触来提高前体聚碳酸酯如低聚物的结晶度,然后在惰性气流中进行固态聚合 气体如氮气。 固态聚合操作包括在约215-225℃的恒定温度下加热的阶段,任选地在约180-190℃的恒定温度下与第一加热阶段组合。方法 适用于连续操作,并且通过凝胶渗透色谱法相对于聚苯乙烯产生数均分子量为至少15,000的聚碳酸酯。
    • 7. 发明授权
    • Extrusion method for making polycarbonate
    • 制造聚碳酸酯的挤出方法
    • US06420512B1
    • 2002-07-16
    • US09911439
    • 2001-07-24
    • Patrick Joseph McCloskeyJames DayPaul Michael SmigelskiJohn Lester MaxamJohn Aibangbee Osaheni
    • Patrick Joseph McCloskeyJames DayPaul Michael SmigelskiJohn Lester MaxamJohn Aibangbee Osaheni
    • C08G6400
    • C08G64/307
    • Extrusion of a mixture of an ester-substituted diaryl carbonate, such as bis-methyl salicyl carbonate, a dihydroxy aromatic compound such as bisphenol A and a transesterification catalyst such as tetrabutyl phosphonium acetate (TBPA) affords polycarbonate having a weight average molecular weight of greater than 20,000 Daltons. The extruder is equipped with one or more vacuum vents to remove by-product ester-substituted phenol. Similarly, a precursor polycarbonate having ester-substituted phenoxy endgroups, for example methyl salicyl endgroups, when subjected to extrusion affords a polycarbonate having a significantly increased molecular weight relative to the precursor polycarbonate. The reaction to form a higher molecular weight polycarbonate may be catalyzed by residual transesterification catalyst present in the precursor polycarbonate, or by a combination of any residual catalyst and an additional catalyst such as TBPA introduced in the extrusion step. Fries rearrangement products are not observed in the product polycarbonates.
    • 酯取代的碳酸二芳基酯如碳酸双甲酯,双酚A等二羟基芳族化合物和乙酸四丁基鏻(TBPA)等酯交换催化剂的混合物的挤出,得到重均分子量大的聚碳酸酯 超过20,000道尔顿。 挤出机配备有一个或多个真空通风口以除去副产物酯取代的苯酚。 类似地,具有酯取代的苯氧基端基的前体聚碳酸酯,例如甲基水杨基端基,当进行挤出时,得到相对于前体聚碳酸酯具有显着增加的分子量的聚碳酸酯。 形成较高分子量聚碳酸酯的反应可以通过存在于前体聚碳酸酯中的残留酯交换催化剂,或者通过任何残余催化剂和另外的催化剂如在挤出步骤中引入的TBPA的组合来催化。 在产品聚碳酸酯中没有观察到薯条重排产物。