Abstract: The invention provides methods and systems for manufacturing low-acid polyalkylene terephthalate, for example, polybutylene terephthalate (PBT). The invention also provides methods and systems for preparing macrocyclic polyester oligomer (MPO) from low-acid polyalkylene terephthalate. Finally, the invention provides methods and systems for preparing MPO via reaction of a diol and a dialkyl ester in an organic solvent to form non-isolated, low-acid polyalkylene terephthalate which undergoes cyclization (depolymerization) to form MPO.

Abstract: The invention provides methods and systems for manufacturing low-acid polyalkylene terephthalate, for example, polybutylene terephthalate (PBT). The invention also provides methods and systems for preparing macrocyclic polyester oligomer (MPO) from low-acid polyalkylene terephthalate. Finally, the invention provides methods and systems for preparing MPO via reaction of a diol and a dialkyl ester in an organic solvent to form non-isolated, low-acid polyalkylene terephthalate which undergoes cyclization (depolymerization) to form MPO.

Abstract: The invention provides methods and systems for manufacturing low-acid polyalkylene terephthalate, for example, polybutylene terephthalate (PBT). The invention also provides methods and systems for preparing macrocyclic polyester oligomer (MPO) from low-acid polyalkylene terephthalate. Finally, the invention provides methods and systems for preparing MPO via reaction of a diol and a dialkyl ester in an organic solvent to form non-isolated, low-acid polyalkylene terephthalate which undergoes cyclization (depolymerization) to form MPO.

Abstract: The invention relates to methods and systems for the use of an oligomer recyclate from a depolymerization product stream. The oligomer byproduct of a polyester depolymerization reaction can be used as a reactant in the formation of a polyester. For example, linear oligomer byproduct can be used as a reactant in a solution polymerization to form a low-acid polyalkylene terephthalate.

Abstract: Macrocyclic oligoesters and compositions comprising macrocyclic oligoesters are prepared from intermediate molecular weight polyesters. In one embodiment, a diol is contacted with a dicarboxylic acid or a dicarboxylate in the presence of a catalyst to produce a composition comprising a hydroxyalkyl-terminated polyester oligomer. The hydroxyalkyl-terminated polyester oligomer is heated to produce a composition comprising an intermediate molecular weight polyester which preferably has a molecular weight between about 20,000 Daltons and about 70,000 Daltons. The intermediate molecular weight polyester is heated and a solvent is added prior to or during the heating process to produce a composition comprising a macrocyclic oligoester. An optional step is to separate the macrocyclic oligoester from the composition comprising the macrocyclic oligoester.

Abstract: Macrocyclic oligoesters and compositions comprising macrocyclic oligoesters are prepared from intermediate molecular weight polyesters. In one embodiment, a diol is contacted with a dicarboxylic acid or a dicarboxylate in the presence of a catalyst to produce a composition comprising a hydroxyalkyl-terminated polyester oligomer. The hydroxyalkyl-terminated polyester oligomer is heated to produce a composition comprising an intermediate molecular weight polyester which preferably has a molecular weight between about 20,000 Daltons and about 70,000 Daltons. The intermediate molecular weight polyester is heated and a solvent is added prior to or during the heating process to produce a composition comprising a macrocyclic oligoester. An optional step is to separate the macrocyclic oligoester from the composition comprising the macrocyclic oligoester.

Abstract: Macrocyclic oligoesters and compositions comprising macrocyclic oligoesters are prepared from intermediate molecular weight polyesters. In one embodiment, a diol is contacted with a dicarboxylic acid or a dicarboxylate in the presence of a catalyst to produce a composition comprising a hydroxyalkyl-terminated polyester oligomer. The hydroxyalkyl-terminated polyester oligomer is heated to produce a composition comprising an intermediate molecular weight polyester which preferably has a molecular weight between about 20,000 Daltons and about 70,000 Daltons. The intermediate molecular weight polyester is heated and a solvent is added prior to or during the heating process to produce a composition comprising a macrocyclic oligoester. An optional step is to separate the macrocyclic oligoester from the composition comprising the macrocyclic oligoester.

Abstract: Macrocyclic oligoesters and compositions comprising macrocyclic oligoesters are prepared from intermediate molecular weight polyesters. In one embodiment, a diol is contacted with a dicarboxylic acid or a dicarboxylate in the presence of a catalyst to produce a composition comprising a hydroxyalkyl-terminated polyester oligomer. The hydroxyalkyl-terminated polyester oligomer is heated to produce a composition comprising an intermediate molecular weight polyester which preferably has a molecular weight between about 20,000 Daltons and about 70,000 Daltons. The intermediate molecular weight polyester is heated and a solvent is added prior to or during the heating process to produce a composition comprising a macrocyclic oligoester. An optional step is to separate the macrocyclic oligoester from the composition comprising the macrocyclic oligoester.

Abstract: Macrocyclic oligoesters and compositions comprising macrocyclic oligoesters are prepared from intermediate molecular weight polyesters. In one embodiment, a diol is contacted with a dicarboxylic acid or a dicarboxylate in the presence of a catalyst to produce a composition comprising a hydroxyalkyl-terminated polyester oligomer. The hydroxyalkyl-terminated polyester oligomer is heated to produce a composition comprising an intermediate molecular weight polyester which preferably has a molecular weight between about 20,000 Daltons and about 70,000 Daltons. The intermediate molecular weight polyester is heated and a solvent is added prior to or during the heating process to produce a composition comprising a macrocyclic oligoester. An optional step is to separate the macrocyclic oligoester from the composition comprising the macrocyclic oligoester.

Abstract: Macrocyclic oligoesters and compositions comprising macrocyclic oligoesters are prepared from intermediate molecular weight polyesters. In one embodiment, a diol is contacted with a dicarboxylic acid or a dicarboxylate in the presence of a catalyst to produce a composition comprising a hydroxyalkyl-tenninated polyester oligomer. The hydroxyalkyl-terminated polyester oligomer is heated to produce a composition comprising an intermediate molecular weight polyester which preferably has a molecular weight between about 20,000 Daltons and about 70,000 Daltons. The intermediate molecular weight polyester is heated and a solvent is added prior to or during the heating process to produce a composition comprising a macrocyclic oligoester. An optional step is to separate the macrocyclic oligoester from the composition comprising the macrocyclic oligoester.

Abstract: Macrocyclic oligoesters and compositions comprising macrocyclic oligoesters are prepared from intermediate molecular weight polyesters. In one embodiment, a diol is contacted with a dicarboxylic acid or a dicarboxylate in the presence of a catalyst to produce a composition comprising a hydroxyalkyl-terminated polyester oligomer. The hydroxyalkyl-terminated polyester oligomer is heated to produce a composition comprising an intermediate molecular weight polyester which preferably has a molecular weight between about 20,000 Daltons and about 70,000 Daltons. The intermediate molecular weight polyester is heated and a solvent is added prior to or during the heating process to produce a composition comprising a macrocyclic oligoester. An optional step is to separate the macrocyclic oligoester from the composition comprising the macrocyclic oligoester.

Abstract: A process for the redistribution of an organic polycarbonate composition. The process involves melt equilibrating a starting polycarbonate composition (which may be a single polycarbonate or a mixture of polycarbonates, and may be or include recycled polycarbonate) having an initial weight average molecular weight in the presence of a carbonate redistribution catalyst and in the absence of branching agents, under conditions such that a redistributed polycarbonate composition is formed having a weight average molecular weight different from, and typically lower than, the initial weight.

Abstract: Pigmented polycarbonate compositions which are substantially stable with respect to molecular weight and melt viscosity are prepared by blending a redistributed polycarbonate with titanium dioxide free from polysiloxane coatings (i.e., "unpacified" titanium dioxide).

Abstract: A method for making diphenyl carbonate free of color bodies is provided by reacting an organic hydroxy compound, such as phenol with carbon monoxide and oxygen in the presence of an effective amount of a palladium catalyst, in the form of a palladium material which is used in combination with a quaternary ammonium salt, an inorganic cocatalyst, such as cobalt diacetate and an organic cocatalyst such as benzophenone or 1,10-phenanthroline. Recycling of catalyst values is also provided.

Abstract: Macrocyclic oligomers, including polycarbonates, polyesters, polyamides, polyimides, polyetherketones and polyethersulfones, are conveniently prepared from various spiro(bis)indane compounds, especially the 6,6'-difunctional 3,3',3'-tetramethylspiro(bis)indanes. The macrocyclic oligomers may be conveniently converted to linear polymers.

Abstract: Homo- and copolycarbonates of spirobiindane bisphenols are prepared by first reacting phosgene with a substantially pure spirobiindane bisphenol in the presence of aqueous base in a heterogeneous medium at a pH in the range of about 9-11, and subsequently adding an interfacial polycarbonate formation catalyst and, optionally, a dihydroxyaromatic compound and a chain termination agent and continuing phosgene passage at a pH of at least about 10. By this method, there may be prepared homo- and copolycarbonates of 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1-spiro(bis)indane having high molecular weight. Said homopolycarbonates and copolycarbonates with bisphenol A may be used for manufacture of optical disks having low birefrigence.

Abstract: Spirobiindanol polydiorganosiloxane compounds are prepared by the reaction of an .alpha., .omega.-dichloropolydiorganosiloxane with a spirobiindane bisphenol in the presence of an acid acceptor. They are useful as intermediates in the preparation of copolysiloxanecarbonates.

Abstract: Copolysiloxanecarbonate compositions are prepared by the reaction of a carbonate precursor such as phosgene with a mixture of bisphenols including a spirobiindane bisphenol, at least one of said bisphenols containing polydiorganosiloxane moieties. The reaction may take place in one step or sequentially. The products are characterized by low processing temperature, low orientational birefringence and high ductility.

Abstract: Spiro(bis)indane bis-oxyphthalic acid bisimides are prepared by the reaction of a nitro- or halo-substituted phthalimide with a salt of a 6,6'-dihydroxy-3,3,3'3'-tetramethylspiro(bis)indane. The bisimides may be converted to the corresponding dianhydrides, which react with diamines to form polyetherimides, or to the free tetracarboxylic acids or their salts, esters or amides.

Abstract: Macrocyclic oligomers, including polycarbonates, polyesters, polyamides, polyimides, polyetherketones and polyethersulfones, are conveniently prepared from various spiro(bis)indane compounds, especially the 6,6'-difunctional 3,3',3'-tetramethylspiro(bis)indanes. The macrocyclic oligomers may be conveniently converted to linear polymers.