The invention relates to a stoichiometric salt of a tetracarboxylic acid and a diamine of the following general formula (I),

##STR00001##

wherein R.sub.1 is selected from tetravalent residues of butane, cyclobutane, cyclopentane, cyclohexane, tetrahydrofurane and benzophenone and R.sub.2 is selected from divalent residues of unbranched, branched or cyclic aliphatic hydrocarbons with 3 to 15 carbon atoms, with the proviso that the salt of the formula (I) is water-soluble and is selected from compounds (1) to (28); and to the polyimides prepared from these salts by polycondensation.

A resin having a small linear thermal expansion coefficient and a low absorbance is provided. The resin is characterized by including at least one structure selected from structures represented by the following general formulae (1) and (2): ##STR00001##

The present invention is directed to a polyimide resin comprising a structural unit A derived from a tetracarboxylic dianhydride and a structural unit B derived from a diamine, wherein the structural unit A contains a structural unit (A-1) derived from 4,4′-(hexafluoroisopropylidene)diphthalic anhydride, and the structural unit B contains a structural unit derived from an aliphatic diamine, a polyimide resin composition comprising the polyimide resin and inorganic nanoparticles, and a polyimide film comprising the polyimide resin or the polyimide resin composition. Provided are a polyimide resin and a polyimide resin composition, each of which can form a film having not only a heat resistance, and colorlessness and transparency but also low water absorption properties, and a polyimide film.

A benzocyclobutene-containing polyimide resin and a benzocyclobutene-containing polyimide resin composition are provided. The composition includes: (a) a filler: hollow silica, a perfluoroalkoxy alkane resin, or a combination thereof, and (b) a benzocyclobutene-containing polyimide resin with characteristics of high heat resistance, low dielectric property, low elastic modulus, and suitable for manufacturing a redistribution layer and a polyamide film of a semiconductor packaging material in a high-speed and high-frequency field.

A polyimide resin composition containing a polyimide resin (A) and a nanocarbon material (B), wherein the polyimide resin (A) contains a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2), and a content ratio of the repeating structural unit of the formula (1) with respect to the total of the repeating structural unit of the formula (1) and the repeating structural unit of the formula (2) is 20 to 70 mol %: wherein R.sub.1 represents a divalent group having from 6 to 22 carbon atoms containing at least one alicyclic hydrocarbon structure; R.sub.2 represents a divalent chain aliphatic group having from 5 to 16 carbon atoms; and X.sub.1 and X.sub.2 each independently represent a tetravalent group having from 6 to 22 carbon atoms containing at least one aromatic group.

##STR00001##

A resin composition containing a liquid crystal polymer (A) and a predetermined polyimide resin (B), wherein the liquid crystal polymer (A) contains at least one repeating structural unit selected from the group consisting of repeating structural units represented by the following formulas (I) to (IV), and a molded article containing the same:

##STR00001##

wherein a, b, and c represent an average number of repeating structural units.

Provided is a polyimide precursor composition including a polyimide precursor including a siloxane structure and a solvent having a negative partition coefficient (log P). The polyimide precursor composition may be used to alleviate thermal expansion-contraction behavior, thereby producing a polyimide film with minimal curling.

A flame-retardant polyimide molding material and a molded article including the flame-retardant polyimide molding material, where the flame-retardant polyimide molding material includes a semi-aromatic polyimide resin (A) and carbon fiber (B), and the flame-retardant polyimide molding material includes 15 to 80 mass % of the carbon fiber (B).

The present disclosure relates to a polyimide film for a flexible metal clad laminate and a flexible metal clad laminate including the same, and an aspect of the present disclosure is to provide a polyimide film for a flexible metal clad laminate, which is derived from a polyimide precursor composition including an acid dianhydride and a diamine, in which the acid dianhydride includes 70% by mol or more of pyromellitic dianhydride (PMDA), and the diamine includes m-tolidine and dimer diamine.

In one aspect, a single layer polymer film includes 25 to 97.5 wt % of a polyimide having a refractive index of 1.74 or less, 0.5 to 20 wt % of a matting agent and 1 to 30 wt % of a black colorant. On an air side, the single layer polymer film has an L* color of 33 or less and a 60° gloss of 10 or less. In another aspect, a single layer polymer film includes 80 to 99 wt % of a polyimide having a refractive index of 1.74 or less and 1 to 30 wt % of a black colorant. A surface of the single layer polymer film has been textured and has a maximum roughness (S.sub.pv) of 7 μm or more, an L* of 33 or less and a 60° gloss of 10 or less.