A poly(amide-imide) copolymer that is a reaction product of a diamine represented by Chemical Formula 1, a tetracarboxylic acid dianhydride including a compound represented by Chemical Formula 2, and a compound represented by Chemical Formula 3: ##STR00001## wherein, in Chemical Formulae 1 to 4, R.sup.1 to R.sup.4, A, and X are the same as defined in the specification.

In a first aspect, a single layer polymer film includes 60 to 99 wt % of a crosslinked polyimide, having a gel fraction in the range of from 20 to 100% and a refractive index of 1.74 or less, and 1 to 40 wt % of a colorant. A surface of the single layer polymer film has been textured and has a maximum roughness (S.sub.pv) of 6 μm or more, an L* color of 30 or less and a 60° gloss of 15 or less. In a second aspect, a coverlay for a printed circuit board includes the single layer polymer film of the first aspect. In third and fourth aspects, processes are disclosed for forming a single layer polymer film including a crosslinked polyimide film including a dianhydride and a diamine.

Disclosed herein are a highly thick polyimide film that contains a reduced number of bubbles therein and exhibits high elasticity and high heat resistance, and a manufacturing method therefor. The polyimide film is obtained by imidizing a poly(amic acid) solution containing an acid dianhydride component including 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA), 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA), and pyromellitic dianhydride (PMDA), and a diamine component including 4,4′-oxydianiline (ODA), para-phenylenediamine (p-phenylenediamine, PPD), and 3,5-diaminobenzoic acid (DABA), and contains a phosphorus (P)-based compound.

Provided herein is a method for manufacturing a polyimide film, the method including the steps of: preparing a polyamic acid solution; preparing a polyamic acid composition by adding a dehydrating agent and an imidizing catalyst to the polyamic acid solution; and applying the polyamic acid to a support to form a film, followed by thermosetting the film in a heater, wherein the thermosetting step comprises a first heating step, a second heating step, and a third heating step, each of the first, the second, and the third step being carried out in a processing temperature range of 100° C. to 550° C.

A resin composition containing a polyimide resin particle (A) and at least one selected from the group consisting of a thermoplastic resin (B) and a thermosetting resin (C), wherein the polyimide resin particle (A) contains a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2), 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 %, and the polyimide resin particle (A) has a volume average particle size D50 of 5 to 200 μm.

(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 ring.)

##STR00001##

The invention relates to new polyimide solutions having ecological and toxicological benefits compared to existing polyimide solutions as well as well as b their use, in particular for coating applications.

A transparent polyimide film, prepared from a copolymerized polyamide acid according to a chemical cyclization method, is provided. The copolymerized polyamide acid requires at least a semi-aromatic polyamide acid, and the semi-aromatic polyamide acid is formed by reacting cyclobutane-1,2,3,4-tetracarboxylic dianhydride (CBDA) and 2,2′-bis(trifluoromethyl)diaminodiphenyl (TFMB). The molar number of dianhydrides of the semi-aromatic polyamide acid is more than 20% of the total molar number of anhydrides of the copolymerized polyamide acid, so that the transparent polyimide film has a light transmittance greater than 80%, a chroma b* less than 5, and a CTE less than 35 ppm/° C.

Provided are a slurry composition having a low thixotropy and a superior handling property; a cured product of this slurry composition; and a substrate, film and prepreg using such cured product, the substrate, film and prepreg exhibiting excellent mechanical properties and a low relative permittivity and dielectric tangent. The slurry composition has a thixotropic ratio of not higher than 3.0, and comprises: (A) a cyclic imide compound having, per molecule, at least one dimer acid backbone, at least one linear alkylene group having not less than 6 carbon atoms, and at least two cyclic imide groups; (B) spherical silica fine particles and/or alumina fine particles having an average particle size of 0.05 to 20 μm when measured by a laser diffraction method; (C) a silane coupling agent capable of reacting with the components (A) and (B); and (D) an organic solvent.

Disclosed herein is a polyimide film that is obtained by imidizing a polyamic acid solution containing two or more dianhydride components selected from the group consisting of 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA), 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA), and pyromellitic dianhydride (PMDA), and a diamine component including m-tolidine and p-phenylenediamine (PPD) and has a glass transition temperature (Tg) of 320° C. or higher, a moisture absorption rate of 0.4% or less, and a dielectric dissipation factor (Df) of 0.004 or less.

A crosslinked polyimide, a polyimide film and a method for preparing thereof, an organic light emitting diode (OLED) device. 4,40-diamino-400-N-carbazolyltriphenylamine and 1,2,4,5-cyclohexanetetracarboxylic dianhydride and a p-xylylenediamine crosslinker are introduced in the present invention. The introduction of a diamine monomer with a large volume of pendant groups increases an asymmetry of the polyimide, destroys a close structure of the polymer, and reduces crystallization properties of the polypolymer, thereby effectively increasing its transmissibility. At the same time, a cross-linked agent, p-xylylenediamine, is introduced, and the cross-linked agent widens a molecular chain spacing, so that the polyimide molecule has a larger free volume. At the same time, the formation of cross-linked is beneficial to reduce a polarizability of the molecule, thereby reducing a dielectric constant of the material. An OLED device with a novel low dielectric constant and high transmittance is prepared in this way.