Metal Atom In Elemental Form Patents (Class 528/276)
  • Publication number: 20150141584
    Abstract: The present invention generally concerns polyester compounds derived from renewable monomer materials and manufacturing process thereof. The invention further pertains to polyester blends presenting improved maximum elongation characteristic.
    Type: Application
    Filed: December 28, 2012
    Publication date: May 21, 2015
    Applicant: Natura Cosméticos S.A.
    Inventors: Christopher Saywell, Shaomin Mai, Clarissa Capelas Romeu, Julio Cesar Legramanti Neves
  • Patent number: 8859713
    Abstract: The invention relates to a process for making polyethylene terephthalate (PET) from ethylene glycol (EG), purified terephthalic acid (PTA) and optionally up to 30 mol % comonomer, using a catalyst system essentially consisting of antimony—(Sb), zinc—(Zn) and phosphorous—(P) compounds, comprising the steps of a) esterifying EG and PTA to form diethyleneglycol terephthalate and oligomers (DGT), and b) melt-phase polycondensing DGT to form polyester and EG1 wherein the Sb- and P-compounds are added in step a) and the Zn-compound is added after step a). With this process PET can be obtained that shows favorable color and optical clarity, also if recycling of EG is applied in the process, and a relatively low rate of acetaldehyde regeneration during melt-processing.
    Type: Grant
    Filed: March 10, 2010
    Date of Patent: October 14, 2014
    Assignee: Saudi Basic Industries Corporation
    Inventors: Mummaneni Venkateswara Rao, Munif Al-Munif, Zahir Bashir
  • Patent number: 8748558
    Abstract: Methods for producing biocompatible compositions are provided. The biocompatible compositions include an aliphatic polyester macromer produced without the use of solvents or catalysts. The resulting aliphatic polyester macromer may be reacted with a polyisocyanate to form an end-capped aliphatic polyester macromer which, in turn, may be reacted with a polyol to produce a polyurethane. The polyurethane, in turn, may be reacted with a second polyisocyanate to produce an isocyanate-functional polyurethane. The compositions prepared by the methods of the present disclosure may be used as adhesives or sealants for medical/surgical uses.
    Type: Grant
    Filed: April 21, 2008
    Date of Patent: June 10, 2014
    Assignee: Covidien LP
    Inventors: Walter Skalla, Allison Calabrese, Ahmad R. Hadba, Nadya Belcheva
  • Patent number: 8563677
    Abstract: A stable catalyst solution suitable for catalyzing the polycondensation of reactants to make polyester polymers comprising: (i) M, wherein M is represented by an alkaline earth metal or alkali metal and (ii) aluminum metal and (iii) a polyhydroxyl solvent having at least 3 carbon atoms and at least two primary hydroxyl groups, the longest carbon chain being a hydrocarbon; such as 1,3-propane diol, 1,4-butane diol, 1,5-pentane diol, or combinations thereof, wherein the molar ratio of M:Al ranges from 0.75:1 to less than 1.5:1. The catalyst solution is desirably a solution which does not precipitate upon standing over a period of at least one week at room temperature (25° C.-40° C.), even at molar ratios of M:Al approaching 1:1. There is also provided a method for the manufacture of the solution, its feed to and use in the manufacture of a polyester polymer, and polyester polymers obtained by combining certain ingredients or containing the residues of these ingredients in the composition.
    Type: Grant
    Filed: February 27, 2007
    Date of Patent: October 22, 2013
    Assignee: Grupo Petrotemex, S.A. de C.V.
    Inventor: Jason Christopher Jenkins
  • Patent number: 8252888
    Abstract: The present invention relates to a method for the continuous production of high-molecular polyesters by esterification of dicarboxylic acids and/or transesterification of dicarboxylic acid esters with diols and/or mixtures thereof in the presence of catalysts with formation of a prepolymer in a tower reactor and polycondensation thereof to form a high-molecular polyester in a polycondensation reactor, a prepolymer with >40 to 70 repeat units (DP) being produced in the tower reactor and this prepolymer being polycondensed in only one further reactor to form a polyester with >150 to 205 DP.
    Type: Grant
    Filed: January 23, 2012
    Date of Patent: August 28, 2012
    Assignee: Uhde Inventa-Fischer GmbH
    Inventor: Eike Schulz Van Endert
  • Publication number: 20120136132
    Abstract: The present invention relates to a method for the continuous production of high-molecular polyesters by esterification of dicarboxylic acids and/or transesterification of dicarboxylic acid esters with diols and/or mixtures thereof in the presence of catalysts with formation of a prepolymer in a tower reactor and polycondensation thereof to form a high-molecular polyester in a polycondensation reactor, a prepolymer with >40 to 70 repeat units (DP) being produced in the tower reactor and this prepolymer being polycondensed in only one further reactor to form a polyester with >150 to 205 DP.
    Type: Application
    Filed: January 23, 2012
    Publication date: May 31, 2012
    Inventor: Eike Schulz Van Endert
  • Patent number: 8163841
    Abstract: Polyethylene naphthalate fibers that are characterized in that the fibers have a crystal volume of from 550 to 1,200 nm3 obtained by wide angle X-ray diffraction of the fiber and a degree of crystallization of from 30 to 60%. It is preferred that the fibers have a maximum peak diffraction angle of wide angle X-ray diffraction of from 25.5 to 27.0° and a melting point of from 285 to 315° C. The production method thereof is characterized in that a particular phosphorus compound is added to the polymer in a molten state, the spinning draft ratio after discharging from the spinneret is from 100 to 5,000, and the molten polymer immediately after discharging from the spinneret is allowed to pass through a heat-retaining spinning chimney at a temperature within ±50° C. of a temperature of the molten polymer, and is drawn.
    Type: Grant
    Filed: March 4, 2009
    Date of Patent: April 24, 2012
    Assignee: Teijin Fibers Limited
    Inventors: Shintaro Shimada, Fuyuki Terasaka
  • Patent number: 8158718
    Abstract: Polyethylene naphthalate fibers that are characterized in that the fibers have a crystal volume of from 100 to 200 nm3 obtained by wide angle X-ray diffraction of the fiber and a degree of crystallization of from 30 to 60%. It is preferred that the fibers have a maximum peak diffraction angle of wide angle X-ray diffraction of from 23.0 to 25.0°. The production method thereof is characterized in that a particular phosphorus compound is added to the polymer in a molten state, the spinning speed is from 4,000 to 8,000 m/min, and the molten polymer immediately after discharging from the spinneret is allowed to pass through a heated spinning chimney at a high temperature exceeding a temperature of the molten polymer by 50° C. or more, and is drawn.
    Type: Grant
    Filed: March 4, 2009
    Date of Patent: April 17, 2012
    Assignee: Teijin Fibers Limited
    Inventors: Shintaro Shimada, Fuyuki Terasaka
  • Publication number: 20110065829
    Abstract: The disclosed is a biodegradable copolymer, an amphiphilic diblock copolymer, composed of a hydrophilic segment and a hydrophobic segment. The hydrophilic segment is an endcapped PEG or derivatives thereof. The hydrophilic segment is a random polymer polymerized of lactone or cyclic C3-C6 molecule and lactic acid/glycolic acid. There is no coupling agent between the hydrophilic and hydrophobic segments, and the biodegradable copolymer is formed by one-pot ring-opening polymerization. The biodegradable copolymer can be dissolved in water to form a thermosensitive material having a phase transfer temperature of 25 to 50° C., thereby being applied to biological activity factor delivery, tissue engineering, cell culture and biological glue.
    Type: Application
    Filed: November 23, 2010
    Publication date: March 17, 2011
    Applicant: INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE
    Inventors: Ya-Jen YU, Chin-Fu CHEN, Tsai-Yu LIN, Shao-Jen YEH, Shian-Yih WANG, Po-Liang LAI
  • Patent number: 7709595
    Abstract: A stable catalyst solution suitable for catalyzing the polycondensation of reactants to make polyester polymers comprising: (i) M, wherein M is represented by an alkaline earth metal or alkali metal and (ii) aluminum metal and (iii) a polyhydroxyl ether solvent, wherein the molar ratio of M:Al ranges from 0.2:1 to 4:1 or less. The catalyst solution is desirably a solution which does not precipitate upon standing over a period of at least one week at room temperature (25° C.-40° C.), even at molar ratios of M:Al approaching 1:1. There is also provided a method for the manufacture of the solution, its feed to and use in the manufacture of a polyester polymer, and polyester polymers obtained by combining certain ingredients or containing the residues of these ingredients in the composition.
    Type: Grant
    Filed: July 28, 2006
    Date of Patent: May 4, 2010
    Assignee: Eastman Chemical Company
    Inventors: Donna Rice Quillen, Barry Glen Pearcy, Michael Duane Cliffton, Aaron Nathaniel Edens
  • Publication number: 20090131627
    Abstract: There is now provided a polyester polymer particle having an It.V., a surface, and a center, wherein the It.V. at the surface of the particle is less than 0.25 dL/g higher than the It.V. at the center of the particle. The polyester polymer particle is desirably crystalline to prevent the particles from sticking to each other while drying, and desirably contains less than 10 ppm acetaldehyde. A polyester container, preferably a preform or beverage bottle, is made by feeding crystallized polyester particles having an It.V. of at least 0.70 dL/g to an extrusion zone, melting the particles in the extrusion zone to form a molten polyester polymer composition, and forming a sheet or a molded part from extruded molten polyester polymer, wherein at least a portion of the polyester particles have an It.V. at their surface which does not vary from their It.V. at their center by more than 0.25 dL/g, and the particles have not been solid state polymerized. Such polyester compositions have an It.V.
    Type: Application
    Filed: October 24, 2008
    Publication date: May 21, 2009
    Applicant: Eastman Chemical Company
    Inventors: Frederick Leslie Colhoun, Michael Paul Ekart, Mary Therese Jernigan, Stephen Weinhold
  • Patent number: 7527809
    Abstract: A structure containing polyhydroxyalkanoate and a magnetic substance includes an external phase part containing polyhydroxyalkanoate and an internal phase part contained in the external phase part, at least one of the external phase part and the internal phase part containing a magnetic substance. Accordingly, provided is a microcapsule, which can be suitably used for formation of an active ingredient of a sustained release pharmaceutical preparation or an ultrasonic contrast agent.
    Type: Grant
    Filed: April 30, 2004
    Date of Patent: May 5, 2009
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tetsuya Yano, Tsuyoshi Nomoto, Shinya Kozaki, Takeshi Imamura, Tsutomu Honma
  • Publication number: 20090082541
    Abstract: The method for the production of a polyester with improved melting properties and crystallisation properties comprises the steps of (a) production of a pre-polyester melt with an average molecular weight (Mn) of 2000 to 16000 g/mol, (b) solidifying and shaping the melt into pre-polyester particles, and (c) thermally treating the pre-polyester particles in a solid phase in the presence of a transesterification catalyst whereby a molecular weight increase (?Mn) of more than 2000 g/mol occurs. In addition, the prepolyester particles have a carboxyl end group content (XCOOH) of between 0.25 and 0.6 before step c and during the thermal treatment step c, the proportion of the esterification reaction (E) to the polycondensation reaction (E+T) is between 0.5 and 1.
    Type: Application
    Filed: January 19, 2006
    Publication date: March 26, 2009
    Inventors: Andreas Christel, Allan Brent Culbert
  • Patent number: 7332562
    Abstract: The present invention relates to a biodegradable copolyester of high molecular weight and narrow molecular weight distribution. The copolyester has a Mw of 100,000-600,000 g/mol, and a molecular weight distribution of 1.2-3.
    Type: Grant
    Filed: December 21, 2005
    Date of Patent: February 19, 2008
    Assignees: China Petroleum & Chemical Corporation, Beijing Research Institute of Chemical Industry
    Inventors: Wei Chen, Guixiang Zhu, Xirong Chen, Jinglan Lu, Yanxia Zhang, Yifan Yan, Wei Zhang
  • Publication number: 20080027207
    Abstract: A catalyst solution suitable for catalyzing the polycondensation of reactants to make polyester polymers comprising: (i) M, wherein M is represented by an alkaline earth metal or alkali metal and (ii) aluminum metal and (iii) a mono-functional solvent comprising a mono-ol ether of a diol, wherein the molar ratio of M:Al ranges from 0.2:1 to 10:1. The catalyst composition is desirably a solution which does not precipitate upon standing over a period of at least two days, or at least one week at room temperature (25° C.-35° C.), even at molar ratios of M:Al approaching 1:1. There is also provided a method for the manufacture of the composition, its feed to and use in the manufacture of a polyester polymer, and polyester polymers obtained by combining certain ingredients or containing the residues of these ingredients in the composition.
    Type: Application
    Filed: July 28, 2006
    Publication date: January 31, 2008
    Inventor: Jason Christopher Jenkins
  • Publication number: 20080027208
    Abstract: A stable catalyst solution suitable for catalyzing the polycondensation of reactants to make polyester polymers comprising: (i) M, wherein M is represented by an alkaline earth metal or alkali metal and (ii) aluminum metal and (iii) a polyhydroxyl ether solvent, wherein the molar ratio of M:Al ranges from 0.2:1 to 4:1 or less. The catalyst solution is desirably a solution which does not precipitate upon standing over a period of at least one week at room temperature (25° C.-40° C.), even at molar ratios of M:Al approaching 1:1. There is also provided a method for the manufacture of the solution, its feed to and use in the manufacture of a polyester polymer, and polyester polymers obtained by combining certain ingredients or containing the residues of these ingredients in the composition.
    Type: Application
    Filed: July 28, 2006
    Publication date: January 31, 2008
    Inventors: Donna Rice Quillen, Barry Glen Pearcy, Michael Duane Cliffton, Aaron Nathaniel Edens
  • Publication number: 20080027209
    Abstract: A stable catalyst solution suitable for catalyzing the polycondensation of reactants to make polyester polymers comprising: (i) M, wherein M is represented by an alkaline earth metal or alkali metal and (ii) aluminum and (iii) ethylene glycol and (iii) organic hydroxyacid compounds having at least three carbon atoms and less than three carboxylic acid groups when the hydroxyacid compound has 8 or less carbon atoms, wherein the molar ratio of ethylene glycol:aluminum is at least 35:1. The hydroxyacid compounds enhance to solubility of M and Al in ethylene glycol, even at even at molar ratios of M:Al approaching 1:1. There is also provided a method for the manufacture of the composition, its feed to and use in the manufacture of a polyester polymer, and polyester polymers obtained by combining certain ingredients or containing the residues of these ingredients in the composition.
    Type: Application
    Filed: August 29, 2006
    Publication date: January 31, 2008
    Inventor: Alan Wayne White
  • Patent number: 7129317
    Abstract: The present invention relates to slow-crystallizing polyethylene terephthalate resins that possess a significantly higher heating crystallization exotherm peak temperature (TCH) as compared with those of conventional antimony-catalyzed polyethylene terephthalate resins. The polyethylene terephthalate resins of the present invention are especially useful for making hot-fill bottles having exceptional clarity.
    Type: Grant
    Filed: May 21, 2004
    Date of Patent: October 31, 2006
    Assignee: Wellman, Inc.
    Inventors: Tony Clifford Moore, David Eugene Thompson, Sharon Sue Griffith, Carl S. Nichols, Billy Mack Humelsine, Robert Joseph Schiavone
  • Patent number: 6657036
    Abstract: The invention relates to polycondensation resins which are prepared by polycondensation of compounds having a low molecular weight and separation of small molecules in the presence of at least one hetergeneous catalyst. The invention also relates to polyaddition resins which are prepared by polyaddition in the presence of at least one heterogeneous catalyst. The invention further relates to the use of said polycondensation resins and polyaddition resins for the preparation of moulded parts, adhesives and coating materials.
    Type: Grant
    Filed: October 4, 2001
    Date of Patent: December 2, 2003
    Assignee: BASF Coatings AG
    Inventors: Werner-Alfons Jung, Heinz-Peter Rink, Eberhard Fuchs, Wolfgang Straehle
  • Publication number: 20030144459
    Abstract: A polyester resin produced by polycondensing a dicarboxylic acid component containing an aromatic dicarboxylic acid or its ester-forming derivative as the main component and a diol component containing ethylene glycol as the main component in the presence of at least an antimony compound and a phosphorus compound, via an esterification reaction or an ester exchange reaction, which is characterized in that the amount of antimony eluted when immersed in hot water of 95° C. for 60 minutes in the form of particles having a number average particle weight of 24 mg, is not more than 1 &mgr;g per 1 g of the polyester resin, as antimony atoms (Sb).
    Type: Application
    Filed: September 24, 2002
    Publication date: July 31, 2003
    Applicant: MITSUBISHI CHEMICAL CORPORATION
    Inventors: Yoshihiro Fujimori, Kiyotoshi Fujioka, Masahiro Nukui, Yutaka Yatsugi, Kazuya Nakamichi, Noboru Satou, Toshio Kambe, Hirotsugu Niwa
  • Patent number: 6399716
    Abstract: An aromatic group containing copolyester resin composition which has good biodegradability and physical properties, wherein; (i) 0.1 wt % to 30 wt % of an aliphatic prepolymers having number average molecular weight of from 300 to 30,000; (ii) one or a plurality of aromatic dicarboxylic acid (or an acid anhydride thereof which containing aromatic group in the molecule; (iii) one or a plurality of aliphatic (including cyclic type) dicarboxylic acid (or an acid anhydride thereof); and (iv) one or a plurality of aliphatic (including cyclic type) glycol, wherein the copolyester resin has number average molecular weight of from 30,000 to 90,000, weight average molecular weight of from 100,000 to 600,000, melting point of from 70° C. to 150° C., and melt index of from 0.1 to 50 g/10min. (190° C., 2,160 g), and the process for preparing and/or producing the same.
    Type: Grant
    Filed: December 13, 2000
    Date of Patent: June 4, 2002
    Assignee: IRE Chemical Ltd.
    Inventors: Hyun Soo Chung, Jae Wang Lee, Dong Hoon Kim, Do Youn Kim, Suok Woo Lee
  • Patent number: 6022603
    Abstract: An ethylene terephthalate/ethylene-2,6-naphthalene dicarboxylate copolymer comprising 2,6-naphthalenedicarboxylic acid in an amount of 5 to 20 mol % of the total of all dicarboxylic acid components. This copolymer contains Mn, Mg and Co derived from catalysts and P derived from a phosphorus compound as a stabilizer whose amount is controlled to a specific value and is suitable for use as a raw material for molding a bottle having good color (achromatic) and transparency.
    Type: Grant
    Filed: October 5, 1998
    Date of Patent: February 8, 2000
    Assignee: Teijin Limited
    Inventors: Masami Umeda, Kimihiko Sato, Minoru Suzuki
  • Patent number: 5993958
    Abstract: There is disclosed a method of manufacturing a polyester-series photographic support, comprising the steps of: incorporating at least one anthraquinone-series dye into a polyester, which polyester is produced by a condensation polymerization reaction of a dicarboxylic acid component that comprises a dialkyl ester of naphthalene-2,6-dicarboxylic acid as a main component, with a diol component that comprises ethylene glycol as a main component, the polyester being produced by allowing manganese, magnesium, antimony, and phosphorus to be incorporated in specific amounts, whereby the polyester has melt electric resistance in terms of common logarithm (log R) in the melt state at 300.degree. C. in the range of from 7.0 to 9.5, and intrinsic viscosity, measured in a mixture solution of phenol/tetrachloroethane (6/4, weight ratio) at 25.degree. C., in the range of from 0.49 to 0.
    Type: Grant
    Filed: January 21, 1997
    Date of Patent: November 30, 1999
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Toshimitsu Okutsu
  • Patent number: 5977269
    Abstract: The present invention provides polyester/vinyl dioxolane based coating compositions containing no or essentially no volatile organic components. Oligomers for forming the coating compositions of the present invention are vinyl dioxolane end-capped polyester oligomers.
    Type: Grant
    Filed: October 30, 1997
    Date of Patent: November 2, 1999
    Assignee: Foster-Miller, Inc.
    Inventors: Robert F. Kovar, William E. Dorogy, Jr., Brian P. Farrell, Nelson Landrau
  • Patent number: 5391700
    Abstract: This invention provides a process for producing with industrially good efficiency a polyester having a high melting point and biodegradability. In this process, ring-opening copolymerization of a cyclic acid anhydride containing succinic anhydride as a main component with a cyclic ether containing ethylene oxide as a main component is carried out in the presence of a catalyst by introducing successively the cyclic ether into a reaction vessel containing the cyclic acid anhydride in a melting state or solution state. The rate per hour of introducing the cyclic ether is within the range of 3 to 90 parts by weight per 100 parts by weight of the cyclic acid anhydride, and the reaction vessel has an inside pressure within the range of atmospheric pressure to 50 kgf/cm.sup.2 as a gauge pressure.
    Type: Grant
    Filed: April 26, 1994
    Date of Patent: February 21, 1995
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Hiroshi Itoh, Takashi Namba, Hiroya Kobayashi, Masashi Yukitake
  • Patent number: 5340909
    Abstract: A process for producing poly(1,3-propylene terephthalate) from the reaction of either terephthalic acid or a lower dialkyl ester of terephthalic acid and 1,3-propanediol and polymerization of the monomer produced therefrom using a novel catalyst system. The novel catalyst composition includes employing an effective catalytic amount tin in the polycondensation reaction. Using the catalyst system and Hostaperm.RTM. pigments allows for the production of poly(1,3-propylene terephthalate) having yellowness of less than 4 and an IV of at least 0.80 dl/g.
    Type: Grant
    Filed: December 18, 1991
    Date of Patent: August 23, 1994
    Assignee: Hoechst Celanese Corporation
    Inventors: Marvin L. Doerr, Joseph J. Hammer, J. R. Dees
  • Patent number: 5188774
    Abstract: The present invention enables production of an aromatic polyester film having no surface defect and a uniform thickness, while achieving a high productivity, by allowing a molten film of an aromatic polyester to adhere onto a rotating cooling drum to cool the molten film. The molten film has electrical properties characterized by a relatively small AC volume resistivity and has excellent basic properties necessary for adhering onto the rotating cooling drum.
    Type: Grant
    Filed: September 10, 1990
    Date of Patent: February 23, 1993
    Assignee: Teijin Limited
    Inventors: Shozo Nitta, Hideshi Kurihara, Kazuyuki Sanenobu, Tetsuo Ichihashi, Norio Takagi
  • Patent number: 4654413
    Abstract: A polybutylene terephthalate is manufactured by the steps of polycondensating in the liquid phase terephthalic acid or a lower alcohol ester thereof as the acid component and 1,4-butanediol as the diol component to obtain a prepolymer of polybutylene terephthalate, solidifying the prepolymer and further polymerizing the prepolymer in the solid phase to obtain a polybutylene terephthalate of a higher polymerization degree, 0.001 to 5 percent by weight, based on the prepolymer, of a nucleator being added to the polymerization mixture at any time during a period of from the monomer-mixing stage before the starting of the solid phase polymerization, the solid phase polymerization being conducted in the presence of the nucleator uniformly dispersed in the polymerization mixture. The solid polymerization can be treated subsequently to the liquid polymerization and can proceed in a short time.
    Type: Grant
    Filed: December 20, 1985
    Date of Patent: March 31, 1987
    Assignee: Polyplastics Co., Ltd.
    Inventor: Katsuhiko Takahashi
  • Patent number: 4604453
    Abstract: A polyester having an initial accumulation electric charge of not less than 2.9 .mu.c/mm.sup.2 when determined in a melt state according to the method as hereinabove defined and a heat resistance of not more than 0.210 when determined according to the method as hereinabove defined, which comprises at least one magnesium compound and at least one phosphorus compound solubilized therein in amounts as satisfying the following formulas:30.ltoreq.[Mg].ltoreq.400 (1)0.8.ltoreq.Mg/P.ltoreq.3 (2)wherein [Mg] is the content (ppm) of the magnesium compound in terms of magnesium atom to the polyester and Mg/P is the atomic ratio of the magnesium atom in the magnesium compound to the phosphorus atom in the phosphorus compound.
    Type: Grant
    Filed: March 22, 1985
    Date of Patent: August 5, 1986
    Assignee: Toyo Boseki Kabushiki Kaisha
    Inventors: Katsuaki Kuze, Yuziro Matsuyama, Yoshio Yamaoka, Ryuichi Murashige, Osamu Makimura
  • Patent number: 4170697
    Abstract: Silicon halides will react chemically with polyols to produce polyol silicate resinous products which will react chemically with polyisocyanates to produce polyisocyanate silicate solid or cellular solid products.
    Type: Grant
    Filed: June 23, 1978
    Date of Patent: October 9, 1979
    Inventor: David H. Blount
  • Patent number: 4124566
    Abstract: A process for preparing polyesters having superior thermal stability, transparency and chemical resistance, which comprises (1) a first step of esterifying (A) a difunctional carboxylic acid containing at least 60 mole% of an aromatic dicarboxylic acid, (B) 0 to 80 mole%, based on component (A), of an aliphatic diol and/or a dihydroxybenzene and (C) an aromatic monohydroxy compound in an amount of at least 210 mole% as a total of it and component (B) based on component (A), the esterification being performed until the degree of esterification reaches at least 80%, (2) subsequently, a second step of adding 0 to 80 mole%, based on component (A), of component (B) and a bisphenol (D) in an amount of 100 to 130 mole% as a total of it and component (B) based on component (A) to the reaction product obtained in the first step and reacting the mixture, the total amount of components (B) used in the first and second steps being 0 to 80 mole% based on component (C), and (3) performing at least the first of the above st
    Type: Grant
    Filed: June 15, 1977
    Date of Patent: November 7, 1978
    Assignee: Teijin Limited
    Inventors: Noritsugu Saiki, Shizuka Kurisu, Shoji Kawase