Abstract: A polyimide film according to the present invention satisfies Condition (1) in which a tear propagation resistance variation CH is not more than 1.0 g, and/or Condition (2) in which a swelling coefficient CR after being dipped in an alkaline solution is not more than 20.0. By satisfying these conditions, workability of the polyimide film can be improved and working defects can be effectively prevented, thereby improving productivity of each step.

Abstract: A polyimide film according to the present invention satisfies Condition (1) in which a tear propagation resistance variation CH is not more than 1.0 g, and/or Condition (2) in which a swelling coefficient CR after being dipped in an alkaline solution is not more than 20.0. By satisfying these conditions, workability of the polyimide film can be improved and working defects can be effectively prevented, thereby improving productivity of each step.

Abstract: To provide a polyimide film having an original film width of at least 500 mm, whose isotropy in a width direction is improved to have uniform properties, which polyimide film has been apt to cause property difference in the width direction by continuous molding. The polyimide film has an original film width of at least 500 mm and a thickness of at most 50 ?m, wherein the maximum value of MOR-c is at most 1.35 and a tensile elastic modulus is at least 5.0 GPa at any part of the film.

Abstract: The present invention provides a flexible printed circuit which is free from curl, torsion and warpage due to temperature change and excellent flexural endurance. By using polyimide film having an average coefficient of thermal expansion of 1.0×10?5 to 2.5×10?5 cm/cm/° C. in a temperature range of 100° C. to 200° C. and a stiffness value of 0.4 to 1.2 g/cm as the base film for the flexible printed circuit, a flexible printed circuit having excellent thermal dimensional stability and flexural endurance can be prepared.

Abstract: A polyimide film having improved adhesion strength is produced by forming a partially cured and/or dried gel film using a first polyamic acid solution; coating the gel film with the second polyamic acid solution or immersing the gel film in the second polyamic acid solution; and heating the gel film applied with the second polyamic acid solution. By laminating a metal by vapor deposition, sputtering, ion plating, or the like, directly on the polyimide film, a polyimide/metal laminate is provided which has excellent dimensional stability and in which reliability with respect to adhesion between the polyimide film and the metal is improved.

Abstract: In a step of polymerizing polyamic acid by mixing tetracarboxylic acid dianhydride and diamine and polycondensating the tetracarboxylic acid dianhydride and diamine under the presence of a polymerization-use solvent, a tetracarboxylic acid dianhydride slurry in which a tetracarboxylic acid dianhydride is dispersed in a dispersion medium is used. According to this, it is possible to directly manufacture a polyamic acid solution having a high concentration of polyamic acid more than or equal to 10% by weight. Especially, even if a tetracarboxylic acid dianhydride having low solubility in the polymerization-use solvent, it is possible to effectively manufacture a polyamic acid solution having high solids content, by a simple process and in a short time.

Abstract: A polyamide acid solution and/or gel film is subjected to at least any one of the following processes: addition of a semiconducting inorganic filler, addition of a conductivity imparting agent, and formation of a conductive film. Thereafter, the polyamide acid contained in the polyamide acid solution or gel film is imidized. Thus, the obtained semiconducting polyimide film has surface and volume resistances satisfactorily controllable and less dependent on voltage, excellent mechanical properties, and a high elongation rate.

Abstract: A polyimide film according to the present invention satisfies Condition (1) in which a tear propagation resistance variation CH is not more than 1.0 g, and/or Condition (2) in which a swelling coefficient CR after being dipped in an alkaline solution is not more than 20.0. By satisfying these conditions, workability of the polyimide film can be improved and working defects can be effectively prevented, thereby improving productivity of each step.

Abstract: There is provided a process for preparing a polyimide film by a method of casting a film, wherein bubble inclusion and unevenness in thickness are prevented without decrease in mechanical strength at the same time. It is an object of the present invention to provided a process for preparing a polyimide film characterized by extruding, casting and forming into a film a composition of a resin solution obtained by adding, to low viscosity varnish obtained by polymerizing a tetracarboxylic dianhydride component with a diamine component in a molar ratio of 1:1.01 to 1:1.05, or 1:0.95 to 1:0.99, a dehydrating agent in a molar ratio of at least one time and a chemically-imidizing catalyst in a molar ratio of at least half time based on 1 mole of the amic acid of the poly(amic acid) varnish.

Abstract: In etching an organic insulating layer made of a polyimide film, a polyimide containing at least a recurrent unit expressed by general formula (1) is used for the polyimide film: 1

Abstract: A polyimide film of the present invention is a polyimide film having a dynamic viscoelasticity whose tan &dgr; peak is located in a range of not less than 310° C. but not more than 410° C., and whose tan &dgr; value at 300° C. is not more than 0.05, or a polyimide film prepared by copolymerizing (a) an acid dianhydride component including a biphenyltetracarboxylic dianhydride and a pyromellitic dianhydride, and (b) a diamine component, and the polyimide film having such an etching speed that one side thereof is etched with a 1N potassium hydroxide solution at an etching speed of 0.1 &mgr;m/minute (one side) or higher. The polyimide film of the present invention possesses film properties that are necessary for use in an electronic raw material for flexible printed circuit boards and the like, and is suitable as an electronic raw material.

Abstract: To provide a polyimide film having an original film width of at least 500 mm, whose isotropy in a width direction is improved to have uniform properties, which polyimide film has been apt to cause property difference in the width direction by continuous molding.

Abstract: The present invention provides a flexible printed circuit which is free from curl, torsion and warpage due to temperature change and excellent flexural endurance. By using polyimide film having an average coefficient of thermal expansion of 1.0×10−5 to 2.5×10−5 cm/cm/° C. in a temperature range of 100° C. to 200° C. and a stiffness value of 0.4 to 1.2 g/cm as the base film for the flexible printed circuit, a flexible printed circuit having excellent thermal dimensional stability and flexural endurance can be prepared.

Abstract: A process includes the steps of: casting or coating a polyamic acid organic solvent solution on a support and drying the polyamic acid organic solvent solution thereon, so as to form a partially cured and/or partially dried polyamic acid film; dipping the polyamic acid film in tertiary amine or a solution of tertiary amine, or coating tertiary amine or a solution of tertiary amine on the polyamic acid film; and drying the film while imidizing the polyamic acid. In another process, a chemical converting agent and a catalyst are mixed in an organic solvent solution of polyamic acid. After casting and heating the mixture on a support, a partially cured and/or partially dried polyamic acid film is detached from the support. The film contains, with respect to the remaining volatile component, not less than 50 parts of catalyst, not more than 30 parts of solvent, and not more than 20 parts of chemical converting agent and/or a chemical converting agent derived component.

Abstract: Polyimide/metal laminates having a polyimide film and a metal layer laminated thereon, wherein the polyimide film contains titanium element and flexible print wiring boards with the use of the same are disclosed. The polyimide/metal laminates are excellent in adhesion under the ordinary conditions and, moreover, can sustain the adhesive strength at a high ratio after exposure to high temperature or high temperature and high humidity. Owing to these characteristics, these polyimide/metal laminates are appropriately usable in flexible print wiring boards, multi-layered print wiring boards, rigid flex wiring boards, tapes for TAP, semiconductor packages such as CFOs and multi chip modules (MCMs), magnetic recording films, coating films for aerospace materials and filmy resistance elements.

Abstract: In a step of polymerizing polyamic acid by mixing tetracarboxylic acid dianhydride and diamine and polycondensating the tetracarboxylic acid dianhydride and diamine under the presence of a polymerization-use solvent, a tetracarboxylic acid dianhydride slurry in which a tetracarboxylic acid dianhydride is dispersed in a dispersion medium is used. According to this, it is possible to directly manufacture a polyamic acid solution having a high concentration of polyamic acid more than or equal to 10% by weight. Especially, even if a tetracarboxylic acid dianhydride having low solubility in the polymerization-use solvent, it is possible to effectively manufacture a polyamic acid solution having high solids content, by a simple process and in a short time.

Abstract: Polyimide/metal laminates having a polyimide film and a metal layer laminated thereon, wherein the polyimide film contains titanium element and flexible print wiring boards with the use of the same are disclosed. The polyimide/metal laminates are excellent in adhesion under the ordinary conditions and, moreover, can sustain the adhesive strength at a high ratio after exposure to high temperature or high temperature and high humidity. Owing to these characteristics, these polyimide/metal laminates are appropriately usable in flexible print wiring boards, multi-layered print wiring boards, rigid flex wiring boards, tapes for TAP, semiconductor packages such as CFOs and multi chip modules (MCMs), magnetic recording films, coating films for aerospace materials and filmy resistance elements.

Abstract: A polyimide/fluororesin laminate comprises a polyimide film and a fluororesin layer. The tear propagation resistance strength of the polyimide film after being exposed to 150° C. 100% RH environment for 12 hours is not less than 80% of the tear propagation resistance strength of the polyimide film before exposure. Particularly, the polyimide film contains at least one of Al, Si, Ti, Mn, Fe, Co, Cu, Zn, Sn, Sb, Pb, and Bi. The laminate is useful for an insulating tape for wire-winding.

Abstract: There is provided a process for preparing a polyimide film by a method of casting a film, wherein bubble inclusion and unevenness in thickness are prevented without decrease in mechanical strength at the same time. It is an object of the present invention to provided a process for preparing a polyimide film characterized by extruding, casting and forming into a film a composition of a resin solution obtained by adding, to low viscosity varnish obtained by polymerizing a tetracarboxylic dianhydride component with a diamine component in a molar ratio of 1:1.01 to 1:1.05, or 1:0.95 to 1:0.99, a dehydrating agent in a molar ratio of at least one time and a chemically-imidizing catalyst in a molar ratio of at least half time based on 1 mole of the amic acid of the poly(amic acid) varnish.

Abstract: A reaction between epoxy-terminated polyamide and an acid anhydride compound can yield a modified polyamide resin, into resin skeleton of which carboxy groups to react with epoxy resin are introduced. An adhesive agent having excellent heat-resistance can be provided by the use of a composition of this modified polyamide resin and epoxy resin. Furthermore, an adhesive tape for a semiconductor device having excellent properties can be produced by laminating the adhesive agent and the protective layer on one surface of an organic insulated film.