A liquid crystal polyester comprising a structural unit derived from 6-hydroxy-2-naphthoic acid, wherein in thermal extraction GC-MS analysis of the liquid crystal polyester under the following measuring conditions, the relative content of the following impurity component determined from the GC peak area in the total ion chromatogram using methyl 6-hydroxy-2-naphthoate as a standard sample is 50 ppm or less based on the mass of the liquid crystal polyester, and the impurity component has main peaks at m/z=228, 186, 171, and 143 in the MS spectrum chart and a retention time detected in the range of 11.5 to 12.5 min in the total ion chromatogram.

A liquid crystal polymer resin composition is provided containing a component (A) liquid crystal polymer, a component (B′) carbon fiber having a weight-average fiber length of less than 150 μm, and a component (C) carbon precursor having a volume resistivity of 10.sup.2 to 10.sup.10 Ω.Math.cm, in which a content of the component (B′) is 10 to 30 parts by mass with respect to 100 parts by mass of the component (A), a content of the component (C) is 5 to 35 parts by mass with respect to 100 parts by mass of the component (A), and a content of a total of the component (B) and the component (C) is 25 to 60 parts by mass with respect to 100 parts by mass of the component (A).

The present invention is a method for producing a liquid crystalline polyester, which comprises reacting an aromatic hydroxycarboxylic acid, a diol containing 70 mol % or more of an aromatic diol having a structural unit (I) as shown below and an aromatic dicarboxylic acid with one another in the presence of an acylating agent and an aliphatic sulfonic acid represented by formula (A) shown below. (wherein Ar represents a bivalent aromatic group which is an aromatic hydrocarbon group and has a molecular weight of less than 200) Formula (A) R—SO.sub.3H (wherein R represents an alkyl group having 1 to 12 carbon atoms) According to the present invention, a liquid crystalline polyester, which can be molded into an article having excellent tensile strength and excellent creep properties and from which a gas is generated in a reduced amount, can be produced with high efficiency.

Provided are a thermoplastic polymer capable of reducing a dielectric dissipation factor in high frequency bands and a film thereof. The thermoplastic liquid crystal polymer includes repeating units represented by the following formulae (I), (II), (III) and (IV), in which a molar ratio of a total amount of the repeating units represented by formulae (I) and (II) to a total amount of all the repeating units in the thermoplastic liquid crystal polymer is 50 to 90 mol %, and a molar ratio of the repeating unit represented by formula (III) to the repeating unit represented by formula (IV) is the former/the latter=23/77 to 77/23.

A plateable polymer composition is provided. The polymer composition comprises a noble metal catalyst distributed within a polymer matrix containing at least one high naphthenic thermotropic liquid crystalline polymer that includes repeating units derived from naphthenic hydroxycarboxylic and/or dicarboxylic acids in an amount of about 10 mol. % or more, wherein the polymer composition exhibits a dissipation factor of about 0.01 or less as determined at a frequency of 2 GHz.

The present invention relates to a laminate film including a resin layer having a thickness of from 10 μm to 125 μm; and a toner layer formed on one surface of the resin layer, in which the resin layer is formed from a resin material having a glass transition temperature of 130° C. or higher, the toner layer has a plurality of voids, and when a value defined by the following formula (S1) using the void area ratio, which represents the ratio of the area of exposed voids, for the respective faces of the surface of the toner layer and a cross section of the toner layer, is designated as porosity, and when two void area ratios respectively corresponding to the cross sections of the toner layer in two orthogonally intersecting directions are used as the void area ratios of the cross sections of the toner layer, the porosities respectively calculated according to the two void area ratios are both from 0.01% to 0.40%.

[00001]$\begin{array}{cc}\mathrm{Porosity}.Math..Math.\left(\%\right)=\frac{\mathrm{Void}.Math..Math.\mathrm{area}.Math..Math.\mathrm{ratio}.Math..Math.\mathrm{of}.Math..Math.\mathrm{cross}.Math..Math.\mathrm{section}.Math..Math.\left(\%\right)}{100}\times \frac{\mathrm{Void}.Math..Math.\mathrm{area}.Math..Math..Math.\mathrm{ratio}.Math..Math.\mathrm{of}.Math..Math.\mathrm{surface}.Math..Math.\left(\%\right)}{100}\times 100& \end{array}$

An object of the invention is to provide a resin which does not need to incorporate a fluorescent substance and exhibits fluorescence itself. Another object of the invention is to provide a liquid crystal polymer which does not contain a bleeding out substance such as hydrophobic silica and barium sulfate and which has an effect of suppressing fibrillation in the resin itself. The invention relates to a liquid crystal polymer comprising a copolymer of a polymerizable monomer (A) selected from the group consisting of pyromellitic acid or anhydride thereof and a reactive derivative thereof and an other polymerizable monomer (B).

The present invention relates to a pellet of a liquid crystal polyester resin composition containing a liquid crystal polyester resin and an inorganic filler, said pellet being characterized in that if the horizontal Feret's diameter of a rectangle circumscribed about a projected image of the front of the pellet is taken as the length of the long side of the rectangle and the vertical Feret's length is taken as the length of the short side of the rectangle, the length of the long side of the rectangle is from 3 mm to 4 mm (inclusive) and the area ratio of the area S of the projected image to the area S0 of the rectangle, namely S/S0 is from 0.55 to 0.70 (inclusive).

Liquid crystal polyester fibers containing a liquid crystal polyester, in which the liquid crystal polyester has a repeating unit represented by Formula (1), a repeating unit represented by Formula (2), and a repeating unit represented by Formula (3), at least one repeating unit selected from the group consisting of the repeating unit represented by Formula (1), the repeating unit represented by Formula (2), and the repeating unit represented by Formula (3) contains a 2,6-naphthylene group, a content of the repeating unit containing the 2,6-naphthylene group is 40 mol % or greater with respect to a total content of all the repeating units of the liquid crystal polyester, and an orientation degree of the liquid crystal polyester in a length direction of the fiber is 89% to 95%. (1) —O—Ar.sup.1—CO—, (2) —CO—Ar.sup.2—CO—, and (3) —X—Ar.sup.3—Y—, wherein Ar.sup.1 represents a phenylene group, a naphthylene group, or a biphenylylene group, Ar.sup.2 and Ar.sup.3 each independently represent a phenylene group, a naphthylene group, or a biphenylylene group, and at least one selected from the group consisting of Ar.sup.1, Ar.sup.2, and Ar.sup.3 contains a 2,6-naphthylene group. X and Y each independently represent an oxygen atom or an imino group (—NH—). Hydrogen atoms of the group represented by Ar.sup.1, Ar.sup.2, or Ar.sup.3 may be each independently substituted with a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 20 carbon atoms.

The invention provides a resin composition that is capable of relaxing anisotropy while keeping the crystalline structure derived from liquid crystallinity and that has isotropic structure and physicality from a macroscopic view, even after the melt-processed molded article obtained by applying shear has been molded, cooled and fused without applying shear stress and subsequently re-cooled. The resin composition comprises a liquid crystal polyester resin (A) comprising structural unit (I) derived from a hydroxycarboxylic acid, structural unit (II) derived from a diol compound, and structural unit (III) derived from a dicarboxylic acid, and a resin (B) other than the liquid crystal polyester resin (A), and has an X-ray diffraction measured after fusing the resin composition that satisfies a specific condition.