Provided a polyimide compound having high heat resistance and transparency. The polyimide compound according to the present invention is characterized in that it is a reaction product of a diamine compound represented by the following general formula (1):

##STR00001## and an alicyclic tetracarboxylic acid dianhydride represented by the following general formula (2).

##STR00002##

The present invention relates to a liquid crystal alignment agent composition comprising a polymerizable liquid crystal alignment polymer; and a catalyst precursor compound of a specific structure, a method for preparing a liquid crystal alignment film using the same, and a liquid crystal alignment film and a liquid crystal display using the same.

Provided are a coloring resin composition including a resin, a coloring material, and a solvent, in which the resin is a polyimide or polyimide precursor including a repeating unit represented by Formula (1-1) or Formula (1-2), and a content of the coloring material is 30 mass % or more with respect to a total solid content of the composition; a film; a color filter; a solid-state imaging element; and an image display device.

##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.

Compositions including a polyimide and one or more thermally conductive fillers, and compaction rollers for an automated fiber placement machine incorporating the compositions are provided. The polyimide may be a polymeric reaction product of a dianhydride and one or more diamines. The one or more diamines may include a fluorine-containing alkyl ether diamine. The one or more thermally conductive fillers may include one or more of a carbon-based filler, boron nitride, a metal, or combinations thereof. The compositions may have a thermal conductivity of from about 0.2 to about 50 Watts per meter Kelvin (Wm.sup.−1 K.sup.−1).

The present invention relates to a method for producing an optical film, the method comprising: step (I) for dissolving a polyimide-based resin in a solvent to prepare a varnish; step (II) for applying the varnish onto a substrate to form a coating film; and step (III) for drying the coating film to form a film, wherein the polyimide-based resin contains a constitutional unit derived from an aliphatic diamine, the solvent in step (I) has a moisture absorption speed per unit area of 25% by mass/h m.sup.2 or more as measured by a Karl Fischer method, and a time T from the completion of the formation of the coating film in step (II) to the start of the drying of the coating film in step (III) satisfies the following equation (A):

[00001]$\begin{array}{cc}T<\frac{0.0018}{\mathrm{Vs}}& \left(A\right)\end{array}$

wherein Vs represents a moisture absorption speed per minute (% by mass/min) of the solvent as determined by a Karl Fischer method.

A method for producing a polyimide film includes: providing a polyimide coating solution; providing a high temperature resistant polyester substrate; and coating the polyimide coating solution on the high temperature resistant polyester substrate, so that a polyimide wet coating is formed on the high temperature resistant polyester substrate; implementing a first baking step, which includes: baking the polyimide wet coating at a first temperature of between 60° C. and 130° C. to remove a part of organic solvent in the polyimide wet coating; implementing a second baking step, which includes: baking the polyimide wet coating at a second temperature of between 140° C. and 220° C. to remove a residual part of the organic solvent in the polyimide wet coating, so as to form the polyimide film on the high temperature resistant polyester substrate; and separating the polyimide film and the high temperature resistant polyester substrate from each other.

The present invention relates to a method for producing a long optical film, the method comprising a step for preparing a varnish by dissolving a polyimide-based resin in a solvent, wherein the polyimide-based resin contains a constitutional unit derived from an aliphatic diamine, and a moisture absorption speed per unit area of the solvent is 25% by mass/h.Math.m.sup.2 or less as determined by a Karl Fischer method.

Disclosed in the present disclosure are an ultra-high modulus and high-transmittance polyimide thin film, and a preparation method and application therefor. The ultra-high modulus and high-transmittance polyimide thin film is prepared by means of mixing and dissolving polydiamine and polydianhydride in a solvent, adding an end-capping reagent, and performing polymerization reaction and imidization. The ultra-high modulus and high-transmittance polyimide thin film has an ultra-high modulus and high transmittance, and is applicable to fields such as flexible photoelectricity and aerospace, especially to a structural member, a reinforcement layer or a substrate of flexible display and transparent display.

A polyimide precursor, a preparation method thereof, a photosensitive resin composition and a cured product are provided. The polyimide precursor is obtained from a tetracarboxylic dianhydride (A), a diamine (B), and a hydroxyl-containing alkyl (meth)acrylate (C) through ring-opening substitution, and polymerization. The polyimide precursor does not include fluorine. The tetracarboxylic dianhydride (A) and the diamine (B) form a main chain. The hydroxyl-containing alkyl (meth)acrylate (C) is grafted to the main chain to form a branch. A molar ratio of the tetracarboxylic dianhydride (A) to the diamine (B) if from 1:0.95 to 1:1.10.