A polyimide resin of the present invention contains a repeating unit represented by the formula (1). X.sub.1 is a tetravalent organic group having at least one ring structure, and each two of four carbonyl groups bonded to X.sub.1 form a pair and, together with X.sub.1 and a nitrogen atom, form a five-membered ring. R.sub.2 is a hydrogen, an alkyl group having 1-9 carbon atoms, or an alkoxy group having 1-10 carbon atoms. Y is a divalent organic group having a phenolic hydroxyl group. The polyimide resin of the present invention can be practically used as a thermosetting resin composition or a positive type photosensitive resin composition. ##STR00001##

A method for making spherical polymer particles, the method including: providing a polymer solution including a polymer in an amount of less than 10% by weight, based on the total weight of the polymer solution, and an organic solvent; combining the polymer solution, deionized water, and a first surfactant to provide an emulsification composition having an organic solvent fraction of 0.60 or higher by volume; forming an emulsion from the emulsification composition; and adding the emulsion into receiving water maintained at a temperature above the boiling point of the organic solvent for a period sufficient to evaporate the organic solvent, wherein the adding and the evaporating are at a rate effective to form an aqueous slurry comprising spherical polymer particles having a Dv100 (volume-based diameter) of 10 micrometers or less, as measured by laser diffraction.

The present invention provides a polyimide film which, by having a fluorine structure adopted into a rigid polyamide chain structure, exhibits not only superb heat resistance but also enhanced optical properties. Additionally, the polyimide according to the present invention, by having the particular structure, exhibits excellent transparency, heat-resistance, mechanical strength and flexibility, and thus can be utilized in a variety of functions such as an element substrate, display cover substrate, optical film, integrated circuit (IC) package, adhesive film, multi-layered flexible printed circuit (FPC), tape, touch panel, and protective film for optical disks.

A polyamic acid according to one or more embodiments of the present invention contains a structural unit represented by general formula (1) and a structural unit represented by general formula (2). In general formula (1), the plurality of R.sup.1s are each independently a hydrogen atom, a monovalent aliphatic group or an aromatic group. In general formula (2), the plurality of R.sup.2s are each independently an alkyl group having 1-3 carbon atoms or an aryl group having 6-10 carbon atoms. In general formulas (1) and (2), X is a tetravalent organic group. In general formula (2), the plurality of Ys are each independently an alkylene group having 1-3 carbon atoms or an arylene group having 6-10 carbon atoms, and m is an integer of 51-199.

##STR00001##

To provide an alkaline developable negative-type photosensitive resin composition from which a cured film that has a high-resolution and low-taper pattern shape and that are excellent in heat resistance and light blocking property can be obtained. A negative-type photosensitive resin composition is characterized by containing an (A1) first resin, a (A2) second resin, a (C) photopolymerization initiator, and a (D) coloring agent, wherein the (A1) first resin is an (A1-1) polyimide and/or an (A1-2) polybenzo-oxazole, and wherein the (A2) second resin is one or more species selected from a (A2-1) polyimide precursor, a (A2-2) polybenzo-oxazole precursor, a (A2-3) polysiloxane, a (A2-4) cardo based resin, and an (A2-5) acrylic resin, and wherein a content ratio of the (A1) first resin in a total of 100 mass % of the (A1) first resin and the (A2) second resin is within the range of 25 to 90 mass %.

A polyetherimide composition includes specific amounts of a polyetherimide, a block polyestercarbonate, a block poly-carbonate-polysiloxane, and a core-shell impact modifier in which the core includes a polysiloxane and the shell includes a poly(alkyl (meth)acrylate). Relative to a corresponding composition lacking the core-shell impact modifier, the polyetherimide composition exhibits increased impact strength while substantially retaining flame retardancy. Also described are associated articles, including articles formed by additive manufacturing, and a method of additive manufacturing.

A polyetherimide composition includes specific amounts of a polyetherimide, a block polyestercarbonate, a block poly-carbonate-polysiloxane, and a core-shell impact modifier in which the core includes a polysiloxane and the shell includes a poly(alkyl (meth)acrylate). Relative to a corresponding composition lacking the core-shell impact modifier, the polyetherimide composition ex-hibits increased impact strength while substantially retaining flame retardancy. Also described are associated articles, including articles formed by additive manufacturing, and a method of additive manufacturing.

A resin composition for display substrates includes the following: the resin (a): a resin containing, as a main component, a repeating unit represented by the chemical formula (1), wherein the resin contains the total of 95 mass % or more of a tetracarboxylic acid residue A, having 2 or more carbon atoms and an SP value of 15 or more and 17 or less and a diamine residue having an SP value of 11 or more and 13 or less with respect to the total of 100 mass % of A and B contained in the resin; the solvent (b): a solvent having an SP value of 7.5 or more and less than 9.5; and the solvent (c): a solvent having an SP value of 9.5 or more and 14.0 or less;

##STR00001##

wherein R.sup.1 and R.sup.2 independently represent a hydrogen atom, hydrocarbon group having 1 to 10 carbon atoms, alkylsilyl group having 1 to 10 carbon atoms, alkali metal ion, ammonium ion, imidazolium ion, or pyridinium ion.

A photosensitive and via-forming circuit board comprising a laminate unit, a conductor unit, and a cover layer unit is provided. The laminate unit includes an insulating layer, a first conductive wiring layer and a second conductive wiring layer formed at two opposite sides of the insulating layer, respectively, and at least one through-hole surface defining a through hole extending from the upper surface of the first conductive wiring layer through the insulating layer to the lower surface of the second conductive wiring layer. The conductor unit is formed on the at least one through-hole surface. The cover layer unit is formed from a photosensitive composition comprising an epoxy group-containing compound and a photosensitive polyimide capable of reacting with the epoxy group of the epoxy group-containing compound, and includes a first cover layer formed on the first conductive wiring layer and extending into and filling the through hole.

Various embodiments provide random copolyimides that may possess the mechanical, thermal, chemical and optical properties associated with polyimides yet achieve a low energy surface. In various embodiments, the copolyimides may be prepared using a minor amounts of a diamino terminated fluorinated alkyl ether oligomer and a diamino terminated siloxane oligomer. The various embodiments include processes for making the copolyimides containing fluorine and silicon surface modifying agents and anisotropic coatings and articles of manufacture from them. Thus the coatings and articles of manufacture made with the copolyimides of the various embodiments may be characterized as having an anisotropic fluorine and silicon composition and low surface energy.