A polymer composition that comprises from about 50 wt. % to about 90 wt. % of a polymer matrix and from about 10 wt. % to about 50 wt. % of silica particles is provided. The polymer matrix includes a liquid crystalline polymer containing repeating units derived from naphthenic hydroxycarboxylic and/or dicarboxylic acids in an amount of about 15 mol. % or less of the polymer. The silica particles have a median particle size of about 4 micrometers or less. The polymer composition exhibits a tensile modulus of 11,000 MPa or more as determined in accordance with ISO Test No. 527:2019.

A liquid crystal polymer including structural units derived from an aromatic hydroxy carboxylic acid in an amount of greater than about 30 mol % and less than or equal to about 50 mol %, an aromatic dicarboxylic acid which includes about 50 mol % or greater of a structural unit derived from a compound including two carboxyl groups at a meta-position of an aromatic ring in an amount greater than or equal to about 50 mol % of the amount of the structural unit derived from the aromatic hydroxy carboxylic acid, each based on total moles of the structural units in the liquid crystal polymer, and an aromatic diol that is 4,4′-dihydroxybiphenyl, hydroquinone, or a combination thereof; a composite composition including the liquid crystal polymer, an article produced from the liquid crystal polymer or the composite composition, a battery case including the article, and a battery including the battery case and an electrode assembly.

A liquid crystal polyester wherein a linear liquid crystal polymer chain including specific monomers (A) to (C), in which at least one of the monomer (B) and the monomer (C) contains a compound for forming a bent structural unit, and a content of the compound for forming a bent structural unit is 20 to 40% by mol relative to a total molar amount of the monomers (A) to (C), is bonded via a specific monomer (D), and a content proportion of the monomer (D) is 0.01 to 10 mol relative to 100 mol of the total molar amount of the monomers (A) to (C).

A liquid-crystal polymer includes at least one repeating unit having a spiro structure, and the repeating unit occupies 1 mol % to 20 mol % of the liquid-crystal polymer. The liquid-crystal polymer is composed of the following repeating units: 1 mol % to 20 mol % of ##STR00001##
10 mol % to 35 mol % of ##STR00002##
10 mol % to 35 mol % of ##STR00003##
10 mol % to
50 mol % of ##STR00004##
and 10 mol % to 40 mol % of ##STR00005##
AR.sup.1 is ##STR00006##
wherein each of ring R and ring S is independently a C.sub.3-20 ring, ring R and ring S share a carbon atom, and each of K.sup.1 and K.sup.2 is independently a C.sub.5-20 conjugated system. Each of AR.sup.2, AR.sup.3, AR.sup.4, and AR.sup.5 is independently AR.sup.6 or AR.sup.6—Z—AR.sup.7.

A liquid crystal polyester resin composition containing 100 parts by mass of a liquid crystal polyester resin; and at least 5 parts by mass and at most 100 parts by mass of glass components; wherein the glass components contain glass fibers having a length of more than 50 μm and glass fine powders having a length of at least 4 μm and at most 50 μm; the number-average fiber length of the glass fibers is at least 200 μm and at most 400 μm; and the content of the fine powders is at least 20% and at most 95% relative to a total number of the glass components.

What is provided is a method for producing a liquid crystalline polyester, the method including reacting an aromatic diol (A), an aromatic hydroxycarboxylic acid (B), and a naphthalenedicarboxylic acid (C) to obtain a liquid crystalline polyester, in which the naphthalenedicarboxylic acid (C) is a naphthalenedicarboxylic acid powder including 90% by mass or more of naphthalenedicarboxylic acid particles (C1) having a particle size of less than 150 μm as measured by the dry sieving test method of JIS K 0069 (1992).

A liquid crystal polyester resin comprising 42 to 80 mol % of structural unit (I) relative to 100 mol % of the total structural unit of the liquid crystal polyester resin, and ΔS (entropy of melting) defined by equation [1] is 0.01×10.sup.−3 to 2.7×10.sup.−3 J/g.Math.K:

ΔS(J/g.Math.K)=ΔHm(J/g)/Tm(K)  [1]

wherein Tm is an endothermic peak temperature determined by: after observation of an endothermic peak temperature (Tm.sub.1) observed when heating a liquid crystal polyester under temperature rising conditions of 20° C./minute from room temperature in differential scanning calorimetry, the liquid crystal polyester was maintained at a temperature of Tm.sub.1+20° C. for 5 minutes, followed by observation of the endothermic peak temperature observed when the temperature has fallen to room temperature under temperature falling conditions of 20° C./minute and then raised under temperature rising conditions of 20° C./minute, and ΔHm is an endothermic peak area of Tm:

##STR00001##

A liquid crystal polyester resin composition contains a component (P): a liquid crystal polyester resin, a component (M): a non-metallic and powdery pigment having a metallic color, and a component (F): an inorganic filler excluding the component (M).

In order to maintain high haze value of thermoplastic liquid crystalline polymer while to improve total light transmittance, provided is a thermoplastic liquid crystalline polymer molded body having a haze value of 99% or higher, and a thermal expansion coefficient of 16 to 27 ppm/° C., and satisfying a correlation between a light absorption coefficient (ε) and a thickness (x) as: ε≤0.21x.sup.−0.55.

The present invention relates to liquid crystal polyester resin pellets containing a thermoplastic resin comprising a liquid crystal polyester, and a fibrous filler, in which the pellets contain the fibrous filler in the amount of equal to or greater than 1 part by mass and smaller than 120 parts by mass with respect to 100 parts by mass of the thermoplastic resin, and a length-weighted average fiber length of the fibrous filler is equal to or greater than 4 mm and smaller than 50 mm.