Provided is a method for manufacturing an LCP film for a circuit substrate capable of achieving an LCP film for a circuit substrate having a low coefficient of linear thermal expansion and excellent dimensional stability, without excessively impairing excellent basic performance possessed by the liquid crystal polyester, such as mechanical characteristics, electrical characteristics, and heat resistance. The method for manufacturing an LCP film for a circuit substrate at least comprising: a composition provision step of providing an LCP resin composition at least containing 100 parts by mass of a liquid crystal polyester and 1 to 20 parts by mass of a polyarylate; a film forming step of T-die melt-extruding the LCP resin composition to form a T-die melt-extruded LCP film having a coefficient of linear thermal expansion (α2) in a TD direction of 50 ppm/K or more; and a pressurizing and heating step of subjecting the T-die melt-extruded LCP film to pressure and heat treatment to obtain an LCP film for a circuit substrate having a coefficient of linear thermal expansion (α2) in the TD direction of 16.8±12 ppm/K.

A method for preparing a liquid crystal polymer film, comprising: (1) spinning a liquid crystal polymer into fibers, and maintaining the fibers for 0.1 hour to 36 hours at a temperature of 200° C. to 400° C. under a vacuum degree less than 500 Pa for later use; (2) weaving the fibers prepared in step (1) into cloth for later use; and (3) pressing the cloth prepared in step (2) into a film at a temperature of 200° C. to 400° C., and then stretching the film to obtain the liquid crystal polymer film. The liquid crystal polymer film prepared by the preparation method is good in mechanical property, and has a tensile strength that can exceed 170 MPa. The prepared liquid crystal polymer film is applied to a FPC, which makes the FPC have a dielectric constant less than 3, and a small dielectric loss tangent angle.

A polymer composition comprising from about 50 wt. % to about 90 wt. % of a polymer matrix, from about 10 wt. % to about 40 wt. % of inorganic filler particles, and from about 0.1 wt. % to about 10 wt. % of an impact modifier is provided. The polymer matrix includes a liquid crystalline polymer containing one or more repeating units derived from a hydroxycarboxylic acid, wherein the hydroxycarboxylic acid repeating units constitute about 50 mol. % or more of the polymer, and further wherein the liquid crystalline polymer containing repeating units derived from naphthenic hydroxycarboxylic and/or dicarboxylic acids in an amount of about 10 mol. % or more of the polymer. The polymer composition exhibits a tensile elongation of about 4.5% or more and a Charpy notched impact strength of about 100/m.sup.2 or more.

A polymer film is provided, the polymer film comprises a liquid crystal polymer, comprising a soluble liquid crystal polymer and an insoluble liquid crystal polymer; and a polyimide polymer, accounting for 5 wt % or more of the polymer film. A method for manufacturing the polymer film is also provided, the method for manufacturing the polymer film comprises steps: providing a liquid crystal polymer powder, a particle size of the liquid crystal polymer powder is 0.1 um to 20 um; providing a liquid crystal polymer glue, a solid content of which is greater than 3 wt %; providing a polyamic acid glue; mixing the liquid crystal polymer powder, the liquid crystal polymer glue and the polyamic acid glue into a mixed solution, the mixed solution is made into a gel film, and the gel film is baked at a temperature of 300° C. to form a polymer film.

Provided is a liquid crystal polymer composition having a low coefficient of static friction and a low coefficient of kinetic friction both during sliding between a liquid crystal polymer molded body and a metallic material and during sliding between liquid crystal polymer molded bodies. The liquid crystal polymer composition contains a liquid crystal polymer (A), a polytetrafluoroethylene resin (B), and barium sulfate (C).

A liquid crystal polymer composite film is formed from a resin composite including one or more liquid crystal polymers and one or more fillers. The liquid crystal polymer composite film has a thickness in the range of 10 μm-200 μm and a ratio of the in-plane dielectric permittivity in the machine direction to the transverse direction in the range of 1.0-1.4 over a frequency range of 1 Ghz to 10 Ghz. A metal-clad laminate includes the liquid crystal polymer composite film and a metal clad layer laminated to a major surface of the liquid crystal polymer composite film. The metal-clad laminate may be included as part of an antenna.

A photoplethysmographic sensor comprising a light source for emitting light onto a tissue and an optical detector for receiving light that interacts with the tissue is provided. The sensor comprises a liquid crystalline polymer.

Disclosed is a polymerizable liquid crystal material wherein an amount of a salt represented by the following formula (I) is less than 0.01 parts by mass per 100 parts by mass of a polymerizable liquid crystal compound, and an amount of a nitrogen-containing compound represented by the following formula (II) is 0.01 parts by mass or less per 100 parts by mass of the polymerizable liquid crystal compound. R.sup.1 to R.sup.5 each independently represent a hydrogen atom or a C1-C7 alkyl group, R.sup.6 and R.sup.7 represents a hydrogen atom, and X represents F.sup.−, Br.sup.−, Cl.sup.−, I.sup.−, HSO.sub.4.sup.−, 1/2(HPO.sub.4.sup.2−), H.sub.2PO.sub.4.sup.−, R—C(═O)—O.sup.−, 1/2(.sup.−O—(C═O)—R′—(C═O)—O.sup.−) or R—SO.sub.3.sup.−, where R represents a hydrogen atom or a monovalent hydrocarbon group, and R′ represents a single bond or a divalent hydrocarbon group. ##STR00001##

A liquid crystal polyester resin composition includes: (A) liquid crystal polyester; (B) talc; and (C) mica, in which the total amount ((B)+(C)) of the (B) talc and the (C) mica is in a range of 5 parts by mass to 100 parts by mass with respect to 100 parts by mass of the (A) liquid crystal polyester, and a mass ratio ((B)/(C)) of a mass of the (B) talc to a mass of the (C) mica is in a range of 9/1 to 1/9.

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.