Abstract: An aromatic polyimide film having a TD linear expansion coefficient lower than that MD linear expansion coefficient is produced by an industrially advantageous process which is performed under such conditions that a self-supporting aromatic polyimide precursor film having a solvent content 25-45 wt % and an imidation ratio 5-40% is prepared and stretched in the transverse direction under heating initially at 80-240° C. and the stretched self-supporting aromatic polyimide precursor film is subsequently converted to a self-supporting aromatic polyimide film by heating the precursor film at 350-580° C.

Abstract: A polyimide film having no foaming during heating or other problems, as well as a polyimide laminate-metal laminate in which the polyimide film and a metal layer are laminated. The polyimide film includes a polyimide layer (b), and a polyimide layer (a) laminated in contact with the polyimide layer (b), a side of the polyimide layer (b) which is not in contact with the polyimide layer (a) exhibits thermal fusion bondability, a side of the polyimide layer (a) which is not in contact with the polyimide layer (b) does not exhibit thermal fusion bondability, and the polyimide layer (a) includes a polyimide formed from a tetracarboxylic acid component containing 2,3,3?,4?-biphenyltetracarboxylic dianhydride and a diamine component.

Abstract: The present invention provides a polyimide film having an anisotropic thermal expansion coefficient, and comprising a polyimide layer (b) and a polyimide layer (a) on one side or both sides of the polyimide layer (b), wherein the polyimide layer (a) is a layer of a polyimide prepared from a monomer component comprising a diamine having the structure of the following formula (1): wherein R represents a monovalent group selected from the groups listed as the following formula (2): wherein R1 represents a hydrogen atom or a methyl group, and two R1 groups may be the same as, or different from each other.

Abstract: The present invention provides a polyimide film for metallizing, which has an anisotropic thermal expansion coefficient, and comprises a polyimide layer (b) and a polyimide layer (a) on one side or both sides of the polyimide layer (b); wherein the polyimide layer (b) is a layer of a polyimide prepared from an acid component comprising 3,3?,4,4?-biphenyltetracarboxylic dianhydride and a diamine component comprising p-phenylenediamine; and the polyimide layer (a) is a layer of a polyimide prepared from a monomer component comprising at least one selected from the group consisting of phenylenediamines and diaminodiphenyl ethers as a diamine component, and contains a surface treatment agent.

Abstract: An aromatic polyimide film having a TD linear expansion coefficient lower than that MD linear expansion coefficient is produced by an industrially advantageous process which is performed under such conditions that a self-supporting aromatic polyimide precursor film having a solvent content of 25-45 wt. % and an imidation ratio of 5-40% is prepared and stretched in the transverse direction under heating initially at 80-240° C. and the stretched self-supporting aromatic polyimide precursor film is subsequently converted to a self-supporting aromatic polyimide film by heating the precursor film at 350-580° C.