Abstract:
The invention relates to a process for the preparation of water-soluble polymers containing polyalkylene glycol ether side chains and having molecular weights of from 15,000 to 65,000 by solution polymerization of esters of ethylenically unsaturated carboxylic acids and polyalkylene glycols which are masked on the end groups at one end, if desired together with another monomer in at least one hydrocarbon at monomer concentrations of from 70 to 95% by weight in the presence of free-radical-forming polymerization initiators and, if desired, polymerization regulators at temperatures of up to 200° C., removal of the solvent used in the solution polymerization, and dissolution of the polymers in water to give from 50 to 80% strength by weight solutions, with polymers containing acid groups being neutralized if desired.
Abstract:
An apparatus for continuously producing polybutylene terephthalate, which comprises a first reactor for reacting an aromatic dicarboxylic acid with a glycol, thereby producing an oligomer, a second reactor for polycondensating the oligomer, thereby preparing a low polymerization product, and a third reactor for further polycondensating the low polymerization product, thereby producing a high molecular weight polyester, where the second reactor is a vertical, cylindrical polymerization vessel having a plurality of concentrical partitioned reaction compartments therein, each of the reaction compartments being provided with stirring blades and a heater, and an outlet for volatile matters being provided at the upper part of the vessel. The second reactor contributes to efficient and continuous production of polybutylene terephthalate having a good quality.
Abstract:
The present invention is a method of preparing a high molecular weight copolyester bottle resin that has excellent melt processing characteristics. The method includes the steps of reacting a diacid or diester component and a diol component to form modified polyethylene terephthalate, wherein diol component is present in excess of stoichiometric proportions. Together, the diacid or diester component and the diol component must include at least 7 percent comonomer. The remainder of the diacid component is terephthalic acid or dimethyl terephthalate and the remainder of the diol component is ethylene glycol. The modified polyethylene terephthalate is copolymerized in the melt phase to an intrinsic viscosity of between about 0.25 dl/g and 0.40 dl/g to thereby form a copolyester prepolymer. Thereafter the copolyester prepolymer is polymerized in the solid phase to form a high molecular weight bottle resin that has an intrinsic viscosity of at least about 0.70 dl/g, and a solid phase density of less than 1.413 g/cc.
Abstract:
The invention relates to a continuous process for the preparation of segmented elastomer polyester copolymers that shows greater flexibility with respect to the types and amounts of product to be produced than the known processes. The flexibility is achieved by splitting up a low-molecular PBT product stream from a continuous PBT process and partly using it as feed for the transesterification reaction with the polyalkyleneoxide glycol yielding soft segments to form a low-molecular segmented polyester copolymer, which is subsequently further condensed in the melt or optionally in the solid phase to form high-molecular segmented polyester copolymers. Even greater flexibility can be obtained by operating several parallel production lines for segmented polyester copolymer. Fluctuations in the types of copolyester product to be produced and the amounts thereof are accommodated predominantly in the polycondensation step of the PBT production.
Abstract:
A catalyst composition is disclosed. The composition comprises a titanium compound, a solubility promoter, a phosphorus source, a solvent, and optionally a sulfonic acid, a cocatalyst, or both. The cocatalyst can be a cobalt/aluminum catalyst, an antimony compound, or combinations thereof. Also disclosed is a process for producing the composition. The process comprises combining a titanium compound, a solubility promoter, a phosphorus source, a solvent, and optionally a sulfonic acid, a cocatalyst, or both. Further disclosed is a process for using the composition which comprises contacting a carbonyl compound, in the presence of the composition, with an alcohol under a condition suitable for esterification, transesterification, polymerization, or combinations thereof.
Abstract:
The present invention provides a method for producing a liquid crystalline polyester which is produced from an aromatic carboxylic acid, an aromatic hydroxycarboxylic acid, an aromatic diol and/or an aromatic hydroxylamine, including a polymerization step (1) for producing a prepolymer of the liquid crystalline polyester and a solid-state polymerization step (2) for elevating the polymerization degree of the resultant prepolymer, the number of aromatic ring terminal groups of the prepolymer satisfying the following equation (i): [(the number of aromatic ring terminal groups)/[(the number of carboxylic terminal groups)+(the number of aromatic ring terminal groups)]]×100≧7(%) (i). According to the invention, all-aromatic type liquid crystalline polyesters can be produced within a short time and at low cost.
Abstract:
The invention concerns a method for obtaining oxacarbonyl polymers comprising steps which consist in: providing at least monomers comprising at least a cyclic oxacarbonyl function, an initiator, and in polymerising or copolymerising said monomers, in bulk or in solution, the initiator being selected among bicyclic guanidine compounds of formula (I) or (II) wherein one and/or the other of the cycles can be substituted, in at least any one of positions 2, 3, 4, 8, 9 and 10 of formula (I) or in at least any one of positions 2, 3, 7 and 8 of formula (II), by at least a radical selected among the alkyl groups with 1 to 6 carbon atoms, the cycloalkyl groups with 5 to 7 carbon atoms, polystyrene hydrocarbon chains.
Abstract:
A process for producing a wholly aromatic polyester which is excellent in heat resistance, mechanical properties and yet color and has a high degree of polymerization by melt polymerizing a dicarboxylic acid and a diol directly on an industrial scale at a low cost in a short period of time without esterifying the dicarboxylic acid or diol in advance. To produce the wholly aromatic polyester by reacting and molding an aromatic dicarboxylic acid such as terephthalic acid, an aromatic diol such as 2,2-bis(4-hydroxyphenyl)propane and a diaryl carbonate by heating, a combination of a specific pyridine compound and an alkali metal (bi)carbonate, a combination of a specific pyridine compound and an organic tin compound or a specific titanium compound is existent as a catalyst. Thereby, the wholly aromatic polyester having the above properties is obtained.
Abstract:
In a process for producing a polyester containing 1,4-cyclohexanedimethanol (CHDM) as one of its glycol components, an aqueous or a methanolic slurry comprising CHDM and a dicarboxylic acid is prepared. The slurry is maintained at a temperature below the melting point of CHDM. The slurry is then fed into a reactor. The slurry is esterified at sufficient temperatures and pressures, and optionally in the presence of a suitable catalyst, to effect esterification. A prepolymer is formed. The prepolymer is then polycondensed at sufficient temperatures and pressures in the presence of a suitable catalyst to effect polycondensation to form a polyester.