Provided is a polyorganosilsesquioxane capable of forming, when cured, a cured product that offers high surface hardness and good heat resistance, is highly flexible, and has excellent processability. The present invention relates to a polyorganosilsesquioxane including a constitutional unit represented by Formula (1). The polyorganosilsesquioxane includes a constitutional unit represented by Formula (I) and a constitutional unit represented by Formula (II) in a mole ratio of the constitutional unit represented by Formula (I) to the constitutional unit represented by Formula (II) of 5 or more. The polyorganosilsesquioxane has a total proportion of the constitutional unit represented by Formula (1) and a constitutional unit represented by Formula (4) of 55% to 100% by mole based on the total amount (100% by mole) of all siloxane constitutional units. The polyorganosilsesquioxane has a number-average molecular weight of 1,000 to 3,000 and a molecular-weight dispersity (weight-average molecular weight to number-average molecular weight ratio) of 1.0 to 3.0.
[R.sup.1SiO.sub.3/2]  (1)
[Chem. 2]
[R.sup.aSiO.sub.3/2]  (I)
[Chem. 3]
[R.sup.bSiO(OR.sup.c)]  (II)
[Chem. 4]
[R.sup.1SiO(OR.sup.c)]  (4).

A photosensitive epoxy resin composition for formation of an optical waveguide, which can be used as an optical waveguide forming material excellent in thermal coloration resistance, patternability, and R-to-R adaptability (flexibility in an uncured resin state). The photosensitive epoxy resin composition contains an epoxy resin component and a photo-cationic polymerization initiator, wherein the epoxy resin component comprises an epoxy resin having a tri- or higher functional bisphenol-A skeleton.

A composition including a polythiol having more than one thiol groups, a polyepoxide having more than one epoxide group, a photolatent base catalyst that can photochemically generate a first amine, and a second amine phase-separated within the composition. A polymer network preparable from the composition, and a method for making the polymer network are also disclosed.

An encapsulating composition and an organic electronic device comprising the same, and the encapsulating composition which is capable of effectively blocking moisture or oxygen penetrating into the organic electronic device from the outside to secure the lifetime of the organic electronic device, implementing a top-emitting organic electronic device, being applied in an inkjet method, and providing a thin display.

A photoresist composition is provided, which comprises a cationic polymerization resin, a resin A, a photoacid generator, and a solvent, wherein the resin A comprises at least one resin selected from the group consisting of polyester resins and polyether resins and is soluble in a ketone-based organic solvent.

A release agent is disclosed for use with an organic binder system used in metal casting. The binder system has a Part I component including an epoxy resin and a free radical initiator and a Part II component having an epoxy resin and an acrylate, where the Part I and Part II components are kept separate until the time of use. The release agent will typically have a molecular weight in the range of 150 to 160, with eight to ten carbon atoms. Two examples of the epoxide are pinene oxide and decene-1 oxide, each of which is effective as an internal release agent when present in the binder for a cold box process in the range of about 0.15% to about 1% of the total weight of the Part I and Part II components.

This invention relates to an epoxy resin composition for fiber-reinforced composite materials, which contains the following constituent components (A), (B), and (C). Component (A) contains at least one poly-naphthalene-based epoxy resin, component (B) contains at least one alicyclic epoxy resin and/or a divinylarene diepoxide resin, and component (C) contains at least one amine curing agent. This epoxy resin composition, containing a specific combination of particular types of epoxy resin and curatives, provides high heat resistance and high flexural modulus under extreme environmental conditions. More particularly, a cured resin prepared by the epoxy resin composition offers well balanced mechanical properties that are suitable for preparing fiber-reinforced composite materials useful in aircraft components, spacecraft components, automobile components, artificial satellites components, industrial components, and the like.

An adhesive composition includes: a clathrate including a cyclodextrin derivative and a guest compound; an epoxy resin; and a tertiary amine having a base dissociation constant of 5.0 or less, wherein the cyclodextrin derivative has an alkoxy group and a substituted or unsubstituted amino group, the guest compound has a substituted or unsubstituted amino group, and the clathrate has a content of 1 part by mass or more and 2.5 parts by mass or less with respect to 100 parts by mass of the epoxy resin.

An epoxy resin composition includes at least one thiol-based curing agent, a main epoxy resin, and a curing catalyst. The at least one thiol-based curing agent includes a non-hydrolyzable polyfunctional thiol compound having at least one hydroxyl group and/or urea bond. The main epoxy resin is at least one main aliphatic polyfunctional epoxy resin selected from a polyethylene glycol diglycidyl ether, a cyclohexane-based diglycidyl ether, and a dicyclopentadiene-based diglycidyl ether. The epoxy resin composition has a viscosity at 25° C. of 0.05 Pa.Math.s or higher and 3 Pa.Math.s or lower

The present invention provides an insulating film forming composition that excels in insulating properties and heat resistance, suppresses the occurrence of warpage, and can form an insulating film with excellent adhesion. The insulating film forming composition of the present invention contains, as a polymerizable compound, a polyorganosilsesquioxane containing siloxane constituent units; wherein the total content of: constituent units represented by formula (I) [R.sup.aSiO.sub.3/2] (I) and constituent units represented by formula (II) [R.sup.aSiO.sub.2/2(OR.sup.b)] (II) is greater than or equal to 55 mol % of the total amount of the siloxane constituent units; and the polyorganosilsesquioxane has a number average molecular weight of from 500 to 10000 and an epoxy equivalent of from 200 to 2000 g/eq.