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| Parallel and series electro-optic viewing and recording apparatus |
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| Liquid crystal device |
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| Method for improvidng the spatial resolution in an integrated adaptive optics apparatus |
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| Local reference beam generator |
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| Bidirectional optical space switch |
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| Polarization-insensitive fabry-perot tunable filter |
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| Optical connector |
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| Biphenyl esters and liquid crystalline mixtures comprising them |
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Catalyst for polyester production, process for producing polyester using the catalyst, polyester obtained by the process, and uses of the polyester
| Details |
Inventors: Ohmatsuzawa, Takeshi; Ehara, Fujito; Hori, Hideshi; Toyota, Kazuo; Fukutani, Kenzaburou; Imuta, Junichi; Shimizu, Akivoshi; Onogi, Takayuki; Noda, Seiji; Sakai, Masayuki; Hiraoka, Shoji; Nakamachi, Koji; Tsugawa, Michio; Miyazoe, Satoru;
Assignee: Mitsui Chemicals, Inc. (Tokyo, JP)
Primary Examiner: Acquah; Samuel A.
Assistant Examiner:
Attorney, Agent or Firm: Sherman & Shalloway
The present invention provides a catalyst for polyester production capable of producing a polyester with high catalytic activity, a process for producing a polyester using the catalyst and a polyester produced thereby. The catalyst comprises a solid titanium compound obtained by dehydro-drying a hydrolyzate obtained by hydrolysis of a titanium halide and which has a molar ratio (OH/Ti) of a hydroxyl group (OH) to titanium (Ti) exceeding 0.09 and less than 4. In the process, the polyester is obtained by polycondensing an aromatic dicarboxylic acid, or an ester-forming derivative thereof, and an aliphatic diol, or ester-forming derivative thereof, in the presence of the catalyst. The resulting polyester has excellent transparency and tint, a titanium content of 1 to 100 ppm, a magnesium content of 1 to 200 ppm and a magnesium to titanium weight ratio of not less than 0.01. |
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DETAILED DESCRIPTION OF THE INVENTION The catalyst for polyester production according to the present invention, a process for producing a polyester using the catalyst, a polyester obtained by the process and uses of the polyester are described in detail hereinafter.
One embodiment of the catalyst for polyester production according to the invention comprises a solid titanium compound (I-a) and/or a titanium-containing solid compound (I-b) described below, and if necessary, a co-catalyst component (II) described below.
Solid Titanium Compound (7-a), Titanium-containing Solid Compound (7-b) The solid titanium compound (I-a) of the invention is obtained by hydrolyzing a titanium halide and then dehydro-drying the resulting hydrolyzate.
The titanium halide is a compound having at least one titanium atom-halogen atom bond in a molecule.
Examples such compounds include titanium tetrahalides, such as titanium tetrachloride, titanium tetrabromide and titanium tetraiodide; titanium trihalides, such as titanium trichloride; titanium dihalides, such as titanium dichloride; and titanium monohalides.
There is no specific limitation on the method to hydrolyze the titanium halide, and for example, there can be mentioned (1) a method of adding the titanium halide to water, (2) a method of adding water into the titanium halide, (3) a method of passing a gas containing vapor of the titanium halide through water, (4) a method of passing a gas containing water vapor through the titanium halide, (5) a method of contacting a gas containing the titanium halide with a gas containing water vapor.
In the present invention, the method of hydrolysis is not specifically limited as described above, but in each method, it is necessary to allow a large excess of water to act on the titanium halide and thereby completely carry out the hydrolysis.
If the hydrolysis is not completely carried out and if the resulting hydrolyzate is such a partial hydrolyzate as described in Japanese Patent Publication No.
19477/1976, the polycondensation rate may be insufficient
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