Abstract: The purpose of the present invention is to provide: a film having high thermal stability, high bending strength (tensile elongation), small retardation in the thickness direction, a low coefficient of thermal expansion, and high transparency; and a polyamic acid or varnish for obtaining the film. The film satisfies all of requirements (i)-(vi) below. (i) The average value of the coefficient of thermal expansion in the range of 100-200° C. is 35 ppm/K or less. (ii) The absolute value of the retardation in the thickness direction is 200 nm or less per 10 ?m of thickness. (iii) The glass transition temperature is 340° C. or higher. (iv) The total light transmittance is at least 85%. (v) The b* value in the L*a*b* color system is 5 or less. (vi) The tensile elongation is at least 10%.

Abstract: The purpose of the present invention is to provide: a polyimide film which is able to be formed at relatively low temperatures, while being less susceptible to coloring and having high transparency; and a polyamide acid or varnish for achieving this polyimide film. This polyimide film contains a polyimide which is a polymerization product of a tetracarboxylic acid dianhydride component and a diamine component. The tetracarboxylic acid dianhydride component contains from 60% by mole to 100% by mole of a tetracarboxylic acid dianhydride of a specific structure relative to the total amount of the tetracarboxylic acid dianhydride; and the diamine component contains from 30% by mole to 70% by mole of an alicyclic diamine and from 30% by mole to 70% by mole of an alkylene diamine relative to the total amount of the diamine component.

Abstract: The purpose of the present invention is to provide a medical film having excellent transparency, heat resistance, and solvent resistance. This medical film is a medical film including a heat-resistant resin having a glass transition temperature measured by thermomechanical analysis TMA of 190° C. or higher wherein the medical film has a total light transmittance of 80% or higher at a thickness of 10 ?m and a b* value in the L*a*b* color system of 10 or lower.

Abstract: The present invention addresses the problem of providing a flexible electronic element substrate comprising a polyimide layer that has both low ultraviolet transmittance and high visible light transmittance and that is capable of suppressing ultraviolet degradation without any reduction in the performance of an electronic element. In order to solve this problem, the flexible electronic element substrate comprises a polyimide layer that satisfies all of (1) through (3) below: (1) maximum transmittance at a wavelength of 400±5 nm is 70% or higher at a thickness of 5 ?m; (2) the b* value in an L*a*b* color system is 5 or less at a thickness of 5 ?m; and (3) transmittance of light at a wavelength of 350 nm is 10% or less at a thickness of 5 ?m.

Abstract: The purpose of the present invention is to provide: a film having high thermal stability, high bending strength (tensile elongation), small retardation in the thickness direction, a low coefficient of thermal expansion, and high transparency; and a polyamic acid or varnish for obtaining the film. The film satisfies all of requirements (i)-(vi) below. (i) The average value of the coefficient of thermal expansion in the range of 100-200° C. is 35 ppm/K or less. (ii) The absolute value of the retardation in the thickness direction is 200 nm or less per 10 ?m of thickness. (iii) The glass transition temperature is 340° C. or higher. (iv) The total light transmittance is at least 85%. (v) The b* value in the L*a*b* color system is 5 or less. (vi) The tensile elongation is at least 10%.

Abstract: The purpose of the present invention is to provide a medical film having excellent transparency, heat resistance, and solvent resistance. This medical film is a medical film including a heat-resistant resin having a glass transition temperature measured by thermomechanical analysis TMA of 190° C. or higher wherein the medical film has a total light transmittance of 80% or higher at a thickness of 10 ?m and a b* value in the L*a*b* color system of 10 or lower.

Abstract: Provided are a block polyamide acid imide having an appropriate solubility in aqueous alkaline solutions, and block polyimides that are obtained using same and have high transparency and a low coefficient of linear thermal expansion (low CTE). The block polyimide comprises blocks configured from repeating structural units represented by defined formula (1A) and blocks configured from repeating structural units represented by defined formula (1B).

Abstract: Disclosed are a water-insoluble copolymer having a constitutional unit (X) derived from a hydroxycarboxylic acid and a constitutional unit (Y) derived from an amino group-containing polyvalent carboxylic acid, wherein the molar ratio (X/Y) of constitutional units is 2/1?(X/Y)<8/1, and the amide bond proportion of the constitutional unit (Y) represented by the following formula (1) is defined by the following formulae (2-1) to (2-3); a production method thereof, and a resin composition containing the copolymer. Amide bond proportion (%)=A/Asp×100??(1) [A=number of moles of an amide bond in (Y), Asp=number of moles of (Y)] [when 2/1?(X/Y)<4/1] amide bond proportion (%)?25??(2-1) [when 4/1?(X/Y)?6.5/1] amide bond proportion (%)?30??(2-2) [when 6.

Abstract: The present invention addresses the problem of providing: a polyimide film that has a small phase difference in the thickness direction and has a low coefficient of linear thermal expansion; and a polyamic acid and varnish to obtain the same. In order to solve this problem, the present invention provides a polyimide film which comprises polyimide that is produced by reacting a diamine component and a tetracarboxylic dianhydride component, the polyimide film having a coefficient of linear thermal expansion of 35 ppm/K or less over a temperature range of 100 to 200 DEG C, an absolute value of phase difference in the thickness direction of 200 nm or less per 10 ?m thickness, a glass transition temperature of 260 DEG C or more, and a total light transmittance of 85% or more.

Abstract: The present invention addresses the problem of providing a high-transparency polyimide film in which the thickness-direction phase difference Rth is kept within a predetermined range. The present invention also addresses the problem of providing a polyamic acid and a varnish used to obtain the polyimide film. In order to overcome the aforementioned problem, the present invention is a polyimide film containing a polyimide obtained by bringing about a reaction between a tetracarboxylic dianhydride and a diamine, the polyimide film having (a) a thickness-direction phase difference Rth of ?5 to 100 nm per 10 ?m of thickness, (b) a transmittance of 80% or more with respect to light having a wavelength of 400 nm, (c) a haze of 3% or less, and (d) a glass transition point of 250° C. or higher.

Abstract: Provided is a polyimide excellent in heat resistance and colorless transparency and also excellent in flexibility and ultraviolet ray transmittance. The polyimide includes a structural unit represented by Formula (1a) and a structural unit represented by Formula (1b) wherein R is a specific aromatic group.

Abstract: Provided are a block polyamide acid imide having an appropriate solubility in aqueous alkaline solutions, and block polyimides that are obtained using same and have high transparency and a low coefficient of linear thermal expansion (low CTE). The block polyimide comprises blocks configured from repeating structural units represented by defined formula (1A) and blocks configured from repeating structural units represented by defined formula (1B).

Abstract: Provided is a low-cost polyimide, containing cyclohexane diamine as a diamine unit, that has a low thermal expansion coefficient. Said block polyimide contains blocks having the repeating structural unit shown in formula (1A) and blocks having the repeating structural unit shown in formula (1B). This block polyimide is preferably obtained by imidizing a block polyamide acid imide that contains blocks having the repeating structural unit shown in formula (2A) and blocks having the repeating structural unit shown in formula (2B).

Abstract: Provided is a polyimide excellent in heat resistance and colorless transparency and also excellent in flexibility and ultraviolet ray transmittance. The polyimide includes a structural unit represented by Formula (1a) and a structural unit represented by Formula (1b) wherein R is a specific aromatic group.

Abstract: The purpose of the present invention is to provide a block polyamide acid imide having an appropriate solubility in aqueous alkaline solutions, and block polyimides that are obtained using same and have high transparency and a low coefficient of linear thermal expansion (low CTE). This block polyimide comprises blocks configured from repeating structural units represented by formula (1A) and blocks configured from repeating structural units represented by formula (1B).

Abstract: The present invention addresses the problem of providing a high-transparency polyimide film in which the thickness-direction phase difference Rth is kept within a predetermined range. The present invention also addresses the problem of providing a polyamic acid and a varnish used to obtain the polyimide film. In order to overcome the aforementioned problem, the present invention is a polyimide film containing a polyimide obtained by bringing about a reaction between a tetracarboxylic dianhydride and a diamine, the polyimide film having (a) a thickness-direction phase difference Rth of ?5 to 100 nm per 10 ?m of thickness, (b) a transmittance of 80% or more with respect to light having a wavelength of 400 nm, (c) a haze of 3% or less, and (d) a glass transition point of 250° C. or higher.

Abstract: The present invention addresses the problem of providing: a polyimide film that has a small phase difference in the thickness direction and has a low coefficient of linear thermal expansion; and a polyamic acid and varnish to obtain the same. In order to solve this problem, the present invention provides a polyimide film which comprises polyimide that is produced by reacting a diamine component and a tetracarboxylic dianhydride component, the polyimide film having a coefficient of linear thermal expansion of 35 ppm/K or less over a temperature range of 100 to 200 DEG C, an absolute value of phase difference in the thickness direction of 200 nm or less per 10 ?m thickness, a glass transition temperature of 260 DEG C or more, and a total light transmittance of 85% or more.

Abstract: A polylactic acid resin composition containing 100 parts by weight of a polylactic acid compound (A) having a specific moiety represented by the formula (1): —X1—R1—X2— and having a weight average molecular weight (Mw) of 5,000 to 500,000, 5 to 2,000 parts by weight of a lactic acid resin (B) and 0.1 to 10 parts by weight of at least one kind of a transparent nucleating agent (C) selected from carboxylic acid amides, aliphatic alcohols and aliphatic carboxylic acid esters. In the formula (1), X1, X2 and R1 are defined. The resin composition can exhibit improved heat resistance (high crystallinity) and transparency without impairing the rigidity of the polylactic acid resin. A molded article composed of the resin composition is also provided.

Abstract: It is an object of the present invention to provide a resin composition having improved heat resistance (high crystallinity) and transparency without impairing rigidity intrinsic to a polylactic acid based resin, a molded body formed from the resin composition, and a new polylactic acid based resin used in the resin composition. A polylactic acid based resin (A) according to the present invention is characterized by having a specific structural moiety and a weight average molecular weight (Mw) of 5,000 to 1,000,000. A polylactic acid based resin composition according to the present invention is characterized by containing the above-described polylactic acid based resin (A).

Abstract: Provided is a low-cost polyimide, containing cyclohexane diamine as a diamine unit, that has a low thermal expansion coefficient. Said block polyimide contains blocks having the repeating structural unit shown in formula (1A) and blocks having the repeating structural unit shown in formula (1B). This block polyimide is preferably obtained by imidizing a block polyamide acid imide that contains blocks having the repeating structural unit shown in formula (2A) and blocks having the repeating structural unit shown in formula (2B).