Provided is a compound containing a phenolic hydroxy group which has excellent heat resistance, a resist composition which has excellent thermal decomposition resistance, optical sensitivity and resolution, and a composition for a resist underlayer coating which has excellent thermal decomposition resistance and dry etching resistance. The compound containing a phenolic hydroxy group has a molecular structure represented by Structural Formula (1) below: ##STR00001##
wherein R.sup.1 is a hydrogen atom, an alkyl group or an aryl group, n is an integer of 2 to 10, R.sup.2 is any one of an alkyl group, an alkoxy group, an aryl group, an aralkyl group and a halogen atom, m is an integer of 0 to 4, and when m is 2 or greater, a plurality of R.sup.2's may be the same as or different from each other and may be bonded to either one of two aromatic rings of the naphthylene skeleton.

Provided are a photosensitive resin composition which has excellent pattern processabilities (high sensitivity and high resolution) and is excellent in chemical resistance and thermal resistance after thermally treated; a heat-resistant resin or heat-resistant resin precursor used for the composition; and a diamine compound which is a raw material of the resin and the precursor. The diamine compound is a diamine compound represented by a general formula (1).

##STR00001##

A photosensitive composition for the formation of resist underlayer films that contains a novolac phenolic resin resulting from an acid-catalyzed reaction between one or more phenolic trinuclear compounds (A) selected from the group consisting of the compounds of general formula (1) and the compounds of general formula (2) and an aldehyde (B).

##STR00001##

In the formulae, R.sup.1, R.sup.2, and R.sup.3 each independently represent a substituted or unsubstituted alkyl having 1 to 8 carbon atoms, R.sup.4 represents hydrogen, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl, p and q are each independently an integer of 1 to 4, r is an integer of 0 to 4, and s is 1 or 2, with the proviso that the sum of r and s is 5 or less.

A resin composition which is configured such that if the resin composition is formed into a resin composition film that has a thickness of 3.0 μm after a heat treatment at a temperature within the range of 200-350° C., the resin composition film forms a heat-resistant resin film that has a light transmittance of 50% or more at a wavelength of 365-436 nm before the heat treatment, while having a light transmittance of 10% or less at a wavelength of 365-436 nm after the heat treatment. Provided is a resin composition having a function of absorbing ultraviolet light and visible light in a short wavelength range, which is suitable for the formation of a planarization film, an insulating layer and a partition wall that are used for organic light emitting devices or display devices.

The present invention provides a tetracarboxylic acid diester compound shown by the following general formula (1),

##STR00001##

wherein X.sub.1 represents a tetravalent organic group; and R.sub.1 represents a group shown by the following general formula (2),

##STR00002##

wherein the dotted line represents a bond; Y.sub.1 represents an organic group with a valency of k+1; “k” represents 1 or 2; and “n” represents 0 or 1. There can be provided a tetracarboxylic acid diester compound that can give a polyimide precursor polymer soluble in a safe organic solvent widely used as a solvent of a composition and usable as a base resin of a photosensitive resin composition.

The invention provides a novolak resin having excellent properties such as heat resistance, alkali developability, photosensitivity and resolution, a photosensitive composition including the novolak resin, a curable composition including the novolak resin, a cured product thereof, and a resist material which uses the photosensitive composition or the curable composition. The novolak resin is one obtained from a compound (A) having a tris(hydroxyaryl)methine group and an aldehyde compound (B) as essential reaction ingredients. The photosensitive composition includes the novolak resin. The curable composition includes the novolak resin, and the cured product is one obtained from such a composition. The resist material uses the photosensitive composition or the curable composition.

The invention provides a novolak resin having excellent properties such as heat resistance, alkali developability, photosensitivity and resolution, a photosensitive composition including the novolak resin, a curable composition including the novolak resin, a cured product thereof, and a resist material which uses the photosensitive composition or the curable composition. The novolak resin is one obtained from a compound (A) having a tris(hydroxyaryl)methine group and an aldehyde compound (B) as essential reaction ingredients. The photosensitive composition includes the novolak resin. The curable composition includes the novolak resin, and the cured product is one obtained from such a composition. The resist material uses the photosensitive composition or the curable composition.

The present invention relates to a photosensitive resin composition for black matrix, as well as a color filter and a liquid crystal display (LCD) device formed by the composition. The aforementioned photosensitive resin composition comprises an alkali-soluble resin (A), a compound containing vinyl unsaturated group(s) (B), a photo initiator (C), quinonediazide sulfonic acid ester (D), a solvent (E) and black pigment (F). The alkali-soluble resin (A) includes epoxy resin having unsaturated group(s) (A-1), which is obtained by reacting an epoxy resin (i) having at least two epoxy groups with a compound (ii) having at least one vinyl unsaturated group and carboxyl group. The aforementioned photo initiator (C) includes an O-acyloxime compound (C-1).

An object of the present invention is to provide an organic EL display device which causes neither decrease in emission luminance nor pixel shrinkage and is excellent in long-term reliability. The present invention is directed to an organic EL display device including an insulating layer formed on a first electrode of the organic EL display device and constituted of a cured film obtained from a positive type photosensitive resin composition containing (A) an alkali-soluble resin, (B) an o-quinonediazide compound and (C) an organic solvent, wherein the mole ratio S/C obtained when a section of the cured film is measured is greater than or equal to 0.003 and less than or equal to 0.008.

A positive-type photosensitive resin composition includes (A) a phenol resin modified by a compound having an unsaturated hydrocarbon group having 4 to 100 carbon atoms; (B) a compound that produces an acid by light; (C) a thermal crosslinking agent; and (D) a solvent. The positive-type photosensitive resin composition according to the present invention can be developed by an alkaline aqueous solution, and an effect thereof is that a resist pattern having sufficiently high sensitivity and resolution, excellent adhesion, and good thermal shock resistance can be formed.