A polymer, a composition, and a polysiloxane-polyimide material thereof are provided. The polymer includes a first repeat unit and a second repeat unit. The first repeat unit has a structure represented by Formula (I) and the second repeat unit has a structure represented by Formula (II)

##STR00001##

wherein A.sup.1 and A.sup.3 are independently tetravalent moiety; A.sup.2 is a divalent moiety; n≥1; m≥1; R.sup.1 is independently hydrogen, C.sub.1-8 alkyl, C.sub.1-8 fluoroalkyl, C.sub.1-8 alkoxy, or C.sub.6-12 aryl; and R.sup.2 is independently hydrogen, C.sub.1-8 alkyl, C.sub.1-8 fluoroalkyl, C.sub.1-8 alkoxy, C.sub.6-12 aryl, or a reactive functional group.

Provided is a resin composition that has a low melt viscosity, and is capable of being turned into a cured product having a high heat resistance, a high adhesion and a high glass-transition temperature, though having a low permittivity and a low dielectric tangent. The resin composition is a cyclic imide resin composition containing: (a) a cyclic imide compound represented by the following formula (1),

##STR00001## (b) a cyclic imide compound represented by the following formula (2),

##STR00002##

and (c) a curing catalyst.

In a first aspect, a polyimide film includes a dianhydride, a fluorinated aromatic diamine and an aliphatic diamine. The polyimide film has a b* of less than one for a film thickness of at least 30 microns and a glass transition temperature of less than 300° C. In a second aspect, an electronic device includes the polyimide film of the first aspect.

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##

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.

The present invention relates to a polyamic acid composition for packaging electronic components and a method for packaging electronic components using the same, wherein the polyamic acid composition comprises a dianhydride main component having a benzophenone structure as a dianhydride-based monomer in a high proportion and a diamine component having a benzene ring as a diamine-based monomer, whereby it is possible to improve a coefficient of thermal expansion, a glass transition temperature, an elongation, and the like of a polyimide thin film formed therefrom, and when the polyimide thin film is used as a packaging material for an inorganic material such as a silicon water, it exhibits excellent adhesion to the inorganic material and can be easily removed upon O.sub.2 plasma removal, as well as has a remarkably low residual ratio of organic residues on the surface of the inorganic material after the removal, so that it can be easily used as a packaging material for electronic components and the like.

In a first aspect, a polyimide corn position has a glass transition temperature of less than 300° C. and includes a polyimide derived from a dianhydride, a fluorinated aromatic diamine and an aliphatic diamine. A polyimide film made from the polyimide composition has a b* of less than one for a film thickness of at least 30 microns.

Disclosed are a proton exchange membrane made of a crystalline sulfonated polyimide block copolymer, a preparation method and use thereof. The crystalline sulfonated polyimide block copolymer has a chemical structure as shown in Formula (I), in which Ar1 group is an aromatic group containing a naphthyl group, Ar2 group is an aromatic group containing at least one sulfonate group, and x is in the range of 5-100, m is in the range of 1-200, and n is in the range of 5-500.

##STR00001##

A polymer in the present invention contains a structural unit represented by the following general formula (1), where X.sub.1 is a tetravalent organic group, Z.sub.1 is a divalent organic group, and “k” is an integer of 1 to 3. Thus, the present invention provides: a positive photosensitive resin composition and a negative photosensitive resin composition which exhibit favorable solvent solubility and are capable of forming a fine pattern with high resolution as a result of solubility in an aqueous alkaline solution; a polyimide-based polymer usable as a base resin for these compositions; and a patterning method and a method for forming a cured film which use the compositions.

##STR00001##

A cross-linked polyimide of the reaction product of a crosslinking agent and a polyimide. The cross-linking agent having at least two cross-linking moieties and the polyimide has a plurality of polyimide chains having an aryl constituent with a moiety comprised of a reactive substituent. The polyimide has crosslinks from the reaction of the reactive substituent of the aryl constituents of the polyimide chains and the cross-linking moieties of the cross-linking agent. The cross-linking may be induced by thermally treating a mixture of the polyimide and crosslinking agent above about 150° C. to a temperature where the polyimide begins to decompose under an inert atmosphere. The membrane can be used for separations involving gases such as hydrogen and light hydrocarbons.