Abstract: A method for producing a decolorized polyester according to the present invention includes: a step of preparing a polyester colored with a colorant, and a decolorizing agent containing a glycol ether-type compound having a boiling point at atmospheric pressure of 160° C. or higher; and a step of removing the colorant, by bringing the decolorizing agent into contact at least once with the colored polyester while heating the decolorizing agent to a temperature equal to or lower than a melting point of the polyester, to thereby obtain the decolorized polyester.

Abstract: There is provided a method for deionizing a decomposition produced solution resulting from decomposition of a polyester by ethylene glycol. The ester interchange reaction and hydrolysis reaction along with cation removing treatment of a decomposition product resulting from decomposition of a polyester by ethylene glycol are suppressed. Thereby, a method for deionizing the decomposition produced solution with small reductions in yield and purity can be provided.

Abstract: There is provided a method for producing a polyethylene terephthalate for molding which has a low content of cyclic trimer. The present invention is a method for producing a polyethylene terephthalate for molding which comprises (1) a condensation step of condensing bis(2-hydroxyethyl)terephthalate having an ion content of 10 ppm or less and an acid value of 30 mgKOH/g or less to produce an oligomer having an average polymerization degree of 4 to 10, (2) a melt-polymerization step of melt-polymerizing the oligomer to produce a prepolymer having an intrinsic viscosity of 0.50 to 0.65, and (3) a solid-state polymerization step of crystallizing pellets of the prepolymer and then solid-state polymerizing the prepolymer at a temperature of 190 to 230° C. to produce a polyethylene terephthalate having an intrinsic viscosity of not lower than 0.65; and a polyethylene terephthalate for molding which is obtained by the method and has specific properties.

Abstract: A method is disclosed for efficiently obtaining BHET of high purity from an EG (ethylene glycol) solution containing crude BHET (bis(2-hydroxyethyl)terephthalate), especially a decomposition product solution obtained by decomposing a polyester containing PET (polyethylene terephthalate) as a main component, by use of EG, while minimizing by-production of impurity components such as DEG (diethylene glycol), DEG ester and oligomers. The decomposition product solution is subjected to crystallization and solid-liquid separation under specific temperature conditions. Further, in accordance with the invention, a method of purifying BHET is taught which comprises evaporation steps of evaporating low-boiling-point components from the decomposition product solution under specific conditions so as to obtain a melt solution and a molecular distillation step of distilling the obtained melt solution under specific conditions so as to obtain a specific fraction.

Abstract: An aromatic polyester is pre-decomposed by heating together with bis-?-hydroxyethyl terephthalate and/or a low condensate thereof and then, reacted with ethylene glycol to convert the terephthalic acid component of the pre-decomposed product into bis-?-hydroxyethyl terephthalate and/or a low condensate thereof. The thus obtained solution composition, that is, bis-?-hydroxyethyl terephthalate solution composition containing ethylene glycol, bis-?-hydroxyethyl terephthalate and cations and/or anions as impurities is brought into contact with a cation exchanger and/or an anion exchanger to remove cations and anions as impurities to produce bis-?-hydroxyethyl terephthalate having a small content of ions.

Abstract: A support system for installing a photovoltaic power generator with photovoltaic modules comprising: calculation means for calculating an installation area of the modules on the basis of geographic information.

Abstract: There is provided a method for producing a polyethylene terephthalate for molding which has a low content of cyclic trimer. The present invention is a method for producing a polyethylene terephthalate for molding which comprises (1) a condensation step of condensing bis(2-hydroxyethyl)terephthalate having an ion content of 10 ppm or less and an acid value of 30 mgKOH/g or less to produce an oligomer having an average polymerization degree of 4 to 10, (2) a melt-polymerization step of melt-polymerizing the oligomer to produce a prepolymer having an intrinsic viscosity of 0.50 to 0.65, and (3) a solid-state polymerization step of crystallizing pellets of the prepolymer and then solid-state polymerizing the prepolymer at a temperature of 190 to 230° C. to produce a polyethylene terephthalate having an intrinsic viscosity of not lower than 0.65; and a polyethylene terephthalate for molding which is obtained by the method and has specific properties.

Abstract: Bis-?-hydroxyethyl terephthalate having an optical density measured in a 10 wt % methanol solution at a measurement wavelength of 380 nm and a cell optical path length of 10 mm of 0.000 to 0.006. The present invention makes it clear that purified BHET having an optical density of 0.006 or less provides high-quality PET having excellent purity, whiteness and transparency.

Abstract: An object of the present invention is to provide a method of obtaining BHET of high purity efficiently from an EG (ethylene glycol) solution containing crude BHET (bis(2-hydroxyethyl)terephthalate), especially a decomposition product solution obtained by decomposing a polyester containing PET (polyethylene terephthalate) as a main component, by use of EG, while minimizing by-production of impurity components such as DEG (diethylene glycol), DEG ester and oligomers.

Abstract: There is provided a method for deionizing a decomposition produced solution resulting from decomposition of a polyester by ethylene glycol.

Abstract: To provide a process for producing a high-purity bis-&bgr;-hydroxyethyl terephthalate from crude terephthalic acid.

Abstract: An aromatic polyester is pre-decomposed by heating together with bis-&bgr;-hydroxyethyl terephthalate and/or a low condensate thereof and then, reacted with ethylene glycol to convert the terephthalic acid component of the pre-decomposed product into bis-&bgr;-hydroxyethyl terephthalate and/or a low condensate thereof.

Abstract: A process for efficiently removing titanium oxide or red oxide from an ethylene glycol solvolysis product of a polyester containing titanium oxide or red oxide. The process comprises the steps of: (1) mixing at least one calcium compound selected from the group consisting of calcium oxide, calcium carbonate and calcium hydroxide with a polyester decomposition product containing titanium oxide which is an ethylene glycol solvolysis product of a polyester containing titanium oxide to agglomerate titanium oxide contained in the polyester decomposition product, or mixing titanium oxide with a polyester decomposition product containing red oxide which is an ethylene glycol solvolysis product of a polyester containing red oxide to agglomerate red oxide contained in the polyester decomposition product; and (2) subjecting the agglomerates to solid-liquid separation to remove titanium oxide or red oxide from the polyester decomposition product.

Abstract: An aromatic polyester is pre-decomposed by heating together with bis-&bgr;-hydroxyethyl terephthalate and/or a low condensate thereof and then, reacted with ethylene glycol to convert the terephthalic acid component of the pre-decomposed product into bis-&bgr;-hydroxyethyl terephthalate and/or a low condensate thereof. The thus obtained solution composition, that is, bis-&bgr;-hydroxyethyl terephthalate solution composition containing ethylene glycol, bis-&bgr;-hydroxyethyl terephthalate and cations and/or anions as impurities is brought into contact with a cation exchanger and/or an anion exchanger to remove cations and anions as impurities to produce bis-&bgr;-hydroxyethyl terephthalate having a small content of ions.

Abstract: To provide a process for producing a high-purity bis-&bgr;-hydroxyethyl terephthalate from crude terephthalic acid.

Abstract: A method of producing a polyester from high-purity bis-&bgr;-hydroxyethyl terephthalate as a raw material containing cations and anions in trace amounts. Polyester production raw materials including bis-&bgr;-hydroxyethyl terephthalate containing cations and anions in a total weight of not more than 50 ppm, ethylene glycol and antimony trioxide and/or germanium dioxide as a polymerization catalyst are heated without substantially distilling off ethylene glycol and then heated under reduced pressure to be polycondensed while ethylene glycol is distilled off.

Abstract: This invention relates to gradation display by a pulse width control method (PWM method) in every pixel in a capacitive display apparatus such as a liquid crystal display apparatus. The driving voltage applied to the electrodes is varied slowly, and the number of gradations of gradation display by the PWM method is increased. Since the capacitive display apparatus is used, for each electrode further from the drive circuit, the driving pulse is more influenced and its persisting duration is extended. As a result, even in identical gradation data, uneven colors may occur. The pulse width applied to the electrodes is gradually decreased as scanning of the electrodes sequentially occurs. Therefore, the brightness of the capacitive display apparatus may be made uniform over the entire screen surface.

Abstract: A driving method of a thin film EL display unit and a driving circuit thereof comprising a thin film EL panel constituted by installing an EL layer between scanning-side electrodes and data-side electrodes and driver ICs which are connected respectively to the scanning-side electrodes and the data-side electrodes, wherein, on a drive which applies a write voltage positive to the data-side electrodes to the scanning-side electrodes, the scanning-side electrodes are raised once to a predetermined potential or higher, and thereafter the positive write voltage is applied thereto, and on a drive which applies a write voltage negative to the data-side electrodes to the scanning-side electrodes, the scanning-side electrodes are reduced once to a predetermined potential or lower, and thereafter the negative write voltage is applied thereto, which can reduce a maximum voltage applied to the scanning-side driver ICs.

Abstract: A driving method is described for thin film EL display devices having an EL layer interposed between scanning side electrodes and data side electrodes which are intersected to each other. The method comprises displaying frames formed by a line sequential drive in which voltage corresponding to display data is applied to the data side electrodes. Concurrently, write pulses which are negative and positive with respect to the data side electrodes are applied to the scanning side electrodes. Further the write pulses which are positive or negative with respect to the data side electrodes are applied to the scanning electrodes. The number of light emitting picture elements of the scanning side electrodes is previously detected from display data and the width of the write pulses, which are at least one of positive or negative is controlled in proportion to the number of the light emitting picture elements. Thus, the brightness of the light emitting picture elements is uniform due to the driving circuit thereof.