Provided a diamine compound, a polyimide precursor and a polyimide film using the same, and a use thereof. The diamine compound may be very useful as a monomer for manufacturing a polyimide film having excellent transparency, high heat resistance, and low retardation.

A monomer represented by Chemical Formula 1: ##STR00001##
wherein, in Chemical Formula 1, R.sup.1, R.sup.2, A.sup.1, A.sup.2, L.sup.1, L.sup.2, o, p, q, and r are the same as defined in the detailed description.

A polymer-dispersed liquid crystal composition, a preparation method of a polymer-dispersed liquid crystal film, and a display panel are provided. The polymer-dispersed liquid crystal composition includes a prepolymer and a liquid crystal molecule, wherein the prepolymer is a fluorine-containing polyimide precursor chemically bonded to a polyaniline, including a polycondensation unit formed from a fluorine-containing dianhydride monomer and a fluorine-containing diamine monomer. In the present application, the conductive polyaniline is chemically bonded to the fluorine-containing polyimide precursor to increase the conductivity of the polyimide precursor. Further, a polymer-dispersed liquid crystal film having a driving voltage lower than 30 V and excellent insulating property and radiation resistance is obtained.

A reactive oligomer has a backbone derived from at least one of polyamideimide, polyimide, polyetherimide, polyaryletherketone, polyethersulfone, polyphenylene sulfide, polyamide, polyester, polyarylate, polyesteramide, polycarbonate, polybenzoxazole or polybenzimidazole and functionalized with at least one unreacted functional group capable of thermal chain extension and crosslinking after formation of the reactive oligomer, wherein the reactive oligomer has an M.sub.n of about 250 to about 10,000 g/mol, calculated using the Carothers equation. Compositions comprising the reactive oligomer have at least one other component that includes a second reactive oligomer, an oligomer lacking unreacted functional groups capable of thermal chain extension and crosslinking, a thermoplastic polymer, a thermoplastic polymer having the same backbone repeat units as the reactive oligomer, a filler, or an additive. A method of manufacture of an article comprises heating a composition comprising the reactive oligomer at a sufficient temperature and time to shape and crosslink the reactive oligomer, including additive manufacturing.

Provided are a polyimide film for a cover window which may satisfy performance required for an advanced cover window, and a use thereof. According to an implementation, it may be useful for a polyimide film for a cover window which has excellent visibility having no optical stain without deterioration of colorless and transparent optical properties, has excellent heat resistance and mechanical properties, and thus, is for use as an optical application or for replacing existing tempered glass, a laminate including the same, and a display device including the same.

A polyimide copolymer, a polyimide film, and a manufacturing method of the polyimide film are provided. The polyimide copolymer includes a plurality of repeating units represented by a following formula (I) and a plurality of repeating units represented by a following formula (II).

##STR00001##

A structural formula of a substituent R.sub.1 is shown as follows:

##STR00002##

A structural formula of a substituent R.sub.2 is shown as follows:

##STR00003##

In addition, the polyimide copolymer has a weight average molecular weight (Mw) of between 30,000 and 200,000.

The present invention provides a resin composition which is highly sensitive and exhibits high chemical resistance even in the case of being baked at a low temperature of 250° C. or less and can suppress the generation of outgas after curing. The present invention is a resin composition which contains (a) an alkali-soluble resin containing polyimide, polybenzoxazole, polyamide-imide, a precursor of any one of these compounds and/or a copolymer of these compounds and (b) an alkali-soluble resin having a monovalent or divalent group represented by the following general formula (1) in a structural unit and in which the modification rate of a phenolic hydroxyl group in the alkali-soluble resin (b) is 5% to 50%. ##STR00001##
(In general formula (1), O represents an oxygen atom. R.sup.1 represents a hydrogen atom or a hydrocarbon group which has 1 to 20 carbon atoms and may be substituted and R.sup.2 represents an alkyl group having 1 to 5 carbon atoms. s and t each independently represent an integer from 0 to 3. Provided that (s+t)≥1. d represents an integer from 0 to 2. u represents an integer from 1 to 2, and * represents a chemical bond.)

Provided is a polyimide having a repeating unit represented by the following Formula (1):

##STR00001##

wherein R.sup.1 represents a tetravalent group; R.sup.2 represents a divalent group; provided that at least one of R.sup.1's is represented by the following Formula (2); and among R.sup.2's, at least one group is represented by the following Formula (3), and at least one other group is represented by the following Formula (4):

##STR00002##

Disclosed herein are a polyimide film for graphite sheets and a graphite sheet manufactured using the same. The polyimide film is fabricated by imidizing a precursor composition including: a polyamic acid prepared by reacting a dianhydride monomer with a diamine monomer; and an organic solvent, wherein the diamine monomer includes about 30 mol % to about 70 mol % of 4,4′-methylenedianiline and about 30 mol % to about 70 mol % of 4,4′-oxydianiline based on the total number of moles of the diamine monomer, 4,4′-methylenedianiline and 4,4′-oxydianiline being present in total in an amount of about 85 mol % or more based on the total number of moles of the diamine monomer.

The purpose of the present invention is to provide: a polyimide film which is able to be formed at relatively low temperatures, while being less susceptible to coloring and having high transparency; and a polyamide acid or varnish for achieving this polyimide film. This polyimide film contains a polyimide which is a polymerization product of a tetracarboxylic acid dianhydride component and a diamine component. The tetracarboxylic acid dianhydride component contains from 60% by mole to 100% by mole of a tetracarboxylic acid dianhydride of a specific structure relative to the total amount of the tetracarboxylic acid dianhydride; and the diamine component contains from 30% by mole to 70% by mole of an alicyclic diamine and from 30% by mole to 70% by mole of an alkylene diamine relative to the total amount of the diamine component.