Mitsui Chemicals, Inc.

Masaki Okazaki

Kenichi Fukukawa

Tatsuhiro Urakami

Yoshihiro Sakata

Atsushi Okubo

Wataru Yamashita

Ichiro Fujio

Hiroshi Miyasako

Hitoshi Ohnishi

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 μm 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%.

Polyamic acid, varnish containing same, film, touch panel display, liquid crystal display, and organic EL display

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&#xb0; C. or higher wherein the medical film has a total light transmittance of 80% or higher at a thickness of 10 &#x3bc;m and a b* value in the L*a*b* color system of 10 or lower.

Medical film and method for producing same, medical coating composition, medical device and method for producing same

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).

Block polyimide, block polyamide acid imide and use thereof

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 &#x3bc;m thickness, a glass transition temperature of 260 DEG C or more, and a total light transmittance of 85% or more.

Polyamic acid, varnish comprising same and polyimide film

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 &#x2212;5 to 100 nm per 10 &#x3bc;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&#xb0; C. or higher.

Polyamic acid, varnish containing same, and polyimide film

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. 

Transparent polyimide and precursor thereof

The purpose of the present invention is to provide a polyimide resin which exhibits higher heat resistance than that of a conventional polyimide resin by controlling the geometric configuration of the constituent units. Provided is a polyamic acid which comprises repeating units represented by general formula (1), wherein the 1,4-bismethylenecyclohexane skeleton units consist of both trans- and cis-form units, and the contents of the trans- and cis-form units are 60 to 100% and 0 to 40% respectively (with the sum total of the trans- and cis-form units being 100%). 

Polyamic acid and polyimide, processes for the production of same, compositions containing same, and uses thereof

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). 

Low-thermal-expansion block polyimide, precursor thereof, and use thereof

A positive photosensitive resin composition containing 100 parts by weight of a polyimide precursor (A) having a constituent unit represented by the formula (1), 15 to 25 parts by weight of a crosslinking agent (B) represented by the formula (2), and 2 to 5 parts by weight of a photosensitizer (C) generating acid upon irradiation of an actinic ray: 

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Chiba, Japan

Masaki Okazaki