Sumitomo Chemical Company, Limited

Tomoya Hosoda

Satoshi Okamoto

Yusaku Kohinata

Shinji Ohtomo

Masanobu Matsubara

Tomoko Uehara

Eiji Hosoda

Hiroshi Harada

Mitsuo Maeda

Toyonari Ito

Toru Fujiki

Disclosed is a material for fiber manufacturing comprising a liquid crystal polyester satisfying the following requirements (a) and (b): (a) the weight-average molecular weight is equal to or less than 30000 and the polydispersity is equal to or less than 2.5; and (b) the melt viscosity measured at 360&#xb0; C. with conditions of a nozzle pore diameter of 0.5 mm and a shear velocity of 1000 susing a flow feature testing machine is equal to or less than 70 Pa&#xb7;s.

Material for fiber manufacturing and fiber

The present invention provides a method for producing a liquid-crystalline polyester, which comprises melt-polymerizing monomers in a reactor having a draw outlet to obtain a polymer melt and drawing the polymer melt through the draw outlet, characterized in that the monomers comprise a compound selected from an aromatic hydroxycarboxylic acid and derivatives thereof, a compound selected from an aromatic dicarboxylic acid and derivatives thereof and a compound selected from an aromatic diol, an aromatic hydroxyamine, an aromatic diamine and derivatives thereof; the amount of units derived from a compound containing a 1,2-phenylene and/or a 1,3-phenylene skeleton(s) in the polyester is from 0 to 10 mol %; the melt polymerization is performed in the presence of a heterocyclic compound containing two or more nitrogen atoms; and the polymer melt has a flow initiation temperature of from 220 to 250&#xb0; C.

Method for producing liquid-crystalline polyester

The present invention provides a method for producing a liquid-crystalline polyester, the method comprising: a step of melt-polymerizing raw monomers in a melt polymerization vessel to obtain a polymer melt; a step of drawing the polymer melt from the melt polymerization vessel and granulating the polymer melt to obtain a granulate; a step of allowing the granulate to undergo solid phase polymerization in a solid phase polymerization vessel to obtain a solid phase polymer; and a step of making an impact on the solid phase polymerization vessel containing the solid phase polymer, and taking out the solid phase polymer from the solid phase polymerization vessel.

The present invention provides a resin composition containing a liquid crystalline polyester and a high dielectric material filler. The present invention also provides a molded article of the liquid crystalline polyester resin composition. The liquid crystalline polyester resin composition of the present invention comprises 50 to 80% by volume of a liquid crystalline polyester which has 40% by mol or more of a 2,6-naphthalenediyl group as an aromatic group, also has a flow initiation temperature of 280&#xb0; C. or higher, and shows a melt tension of 1 g or more measured at a temperature higher than flow initiation temperature; and 20 to 50% by volume of a high dielectric material filler. The liquid crystalline polyester resin composition can be formed into composition pellets easily and stably by a strand method, and a molded article obtained from the liquid crystalline polyester resin composition is excellent in flexural strength and dielectric characteristics.

Liquid crystalline polyester and molded article thereof

The present invention provides a method for producing a liquid-crystalline polyester powder, the method comprising: carrying out melt polycondensation of monomers and/or its acylated monomers to obtain a corresponding polyester having a flow initiation temperature of 240 to 300&#xb0; C.; spreading and solidifying the polyester so as to be a layer thereof with a thickness of 1 cm or more: crushing the solidified substance to obtain a powder having a volume average particle diameter of 3 to 30 &#x3bc;m; and subjecting the powder to a heat treatment to obtain a powder having a flow initiation temperature higher than the flow initiation temperature of the liquid-crystalline polyester after the melt polycondensation.

Method for producing liquid-crystalline polyester powder

The present invention provides a liquid-crystalline polyester having a structural unit represented by the formula (i), a structural unit represented by the formula (ii) and a structural unit represented by the formula (iii): wherein Aris, at each occurrence, a member selected from the group consisting of a 2,6-naphthalenediyl group, a 1,4-phenylene group and a 4,4'-biphenylene group; and Arand Arare, at each occurrence, a member selected from the group consisting of a 2,6-naphthalenediyl group, a 1,4-phenylene group, a 1,3-phenylene group and a 4,4&#x2032;-biphenylene group; wherein 40% by mole or more of all the groups Ar, Arand Arare 2,6-naphthalenediyl groups; and wherein the polyester has a flow initiation temperature of from about 280 to about 320&#xb0; C.

Polyester for producing fiber, and fiber and non-woven fabric using the same

The present invention provides a resin composition comprising a liquid crystal polymer and a filler comprising a composite oxide containing Ba, Sm, and Ti. The resin composition can provide a molded article which has excellent dielectric characteristics and is excellent in dimension stability.

Resin composition and molded article using the same

The present invention provides a liquid crystalline polyester comprising (a) a repeating unit derived from aromatic hydroxycarboxylic acid, (b) a repeating unit derived from aromatic dicarboxylic acid and (c) a repeating unit represented by &#x2014;X&#x2014;Ar1-O&#x2014;Ar1-Y&#x2014;, wherein Ar1 represents 1,4-phenylene which may be substituted by a halogen atom, an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms, and X and Y independently represent O or NH. The polyester in the preset invention has a sufficiently low dielectric constant and/or is a sufficiently high resistance in hydrolysis.

Liquid crystalline polyester and film using the same

A method for producing a polyester is provided, the method comprising the step of reacting an acylated product of a compound having at least one phenolic hydroxyl group with an aromatic carboxylic acid under microwave irradiation. Polyester can be produced by the method in a relatively short period of time at high temperature with a suppressed thermal hysteresis.

Method for producing polyester

A liquid-crystalline polymer composition with less warpage not only in molding but also in a high temperature treatment conducted after molding is provided. The liquid-crystalline polymer comprises (i) 30 to 95% by weight of a first liquid-crystalline polymer having a deflection temperature under load of 200&#xb0; C. or higher and (ii) 5 to 70% by weight of a second liquid-crystalline polymer having a deflection temperature under load lower than that of the first liquid-crystalline polymer, a melting point from 270&#xb0; C. to lower than 400&#xb0; C. and a flow-beginning temperature of 270&#xb0; C. or higher.

Liquid-crystalline polymer composition, method for producing the same, and molded article using the same

A resin composition comprising an inorganic material with a thermal conductivity of 10 W/mK or higher at a temperature of 20&#xb0; C. and an aromatic polyester is provided. The aromatic polyester may have structural units derived from (I) 2-hydroxy-6-naphthoic acid, (II) a compound selected from hydroquinone, 4,4'-dihydroxybiphenyl and 2,6-dihydroxynaphthalene, (III) naphthalenedicarboxylic acid and (IV) a compound selected from terephthalic acid, isophthalic acid and phthalic acid.

Highly thermal-conductive resin composition

An aromatic liquid-crystalline polyester having a small dielectric loss in a wide frequency region is provided. An aromatic liquid-crystalline polyester is provided that can manufacture a film having a small volume expansion by heating. An aromatic liquid-crystalline polyester substantially comprising a repeating structural unit originating in 2-hydroxy-6-naphthoic acid 30 to 80 mol %, a repeating structural unit originating in aromatic diol 35 to 10 mol %, and a repeating structural unit originating in aromatic dicarboxylic acid 35 to 10 mol %.

Aromatic liquid-crystalline polyester and film thereof

An aromatic liquid-crystalline polyester with good moldability into a film is provided. The resulting film has small dielectric loss. The polyester comprises repeating units represented by formulae (I), (II), (III) and (IV), and the molar amounts of repeating units (I)&#x2013;(IV) are 40&#x2013;74.8%, 12.5&#x2013;30%, 12.5&#x2013;30% and 0.2&#x2013;15%, respectively, wherein the molecular amounts of repeating units (III) and (IV) satisfy the relation of (III)/[(III)+(IV)]&#x2267;0.5.

Aromatic liquid-crystalline polyester

The present invention provides an aromatic polyester which is obtained by condensation polymerization reaction of terephthalic acid, 2,6-naphthalenedicarboxylic acid and acylated product obtained by acylation of parahydroxybenzoic acid and hydroquinone with fatty acid anhydride, wherein said aromatic polyester satisfy the following conditions (A) to (D), and the acylation and/or the condensation polymerization reaction are conducted in the presence of heterocyclic organic compound containing at least two nitrogen atoms:

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Tsukuba, Japan

Tomoya Hosoda