A positive photosensitive resin composition including: an alkali-soluble resin containing at least one structure selected from a polyimide structure, a polyamide structure, a polybenzoxazole structure, a polyamide-imide structure, and a precursor structure thereof, a polymer compound having a structural unit formed by cyclopolymerization, and a compound having a quinonediazide structure for serving as a photosensitizer to generate an acid by light and increase a dissolution speed to an alkaline aqueous solution.

Disclosed are a water-absorbing resin and a method of preparing the same, wherein absorbency under unload of the water-absorbing resin is 25 g/g or more, the absorbency under load is 20 g/g or more, and an increase in extractables at a high temperature represented by Equation 1 ranges from 1 or more but less than 3, thereby it is possible to solve a problem that gel-blocking of the water-absorbing resin is accelerated at a high temperature, and improve absorption rate and dry efficiency of the water-absorbing resin.

A photoactive coumarin monomer includes a substituted coumarin molecule that has at least two functional groups may be used to produce a polymer with a coumarin unit or a coumarin derivative unit as part of the polymer backbone. The polymer with a coumarin unit or a coumarin derivative unit as part of the polymer backbone may be photoresponsive and/or bioabsorbable. Photoresponsive polymers with a coumarin unit or a coumarin derivative unit as part of the polymer backbone may crosslink when irradiated at a wavelength of about 320 nm to about 420 nm. The crosslink may be separated when the polymers are irradiated at a wavelength of about 230 nm to about 300. The polymers may also photocleave when irradiated with light at a wavelength of about 230 nm to about 300.

There are provided novel vulcanizable compositions based on optionally fully or partly hydrogenated nitrile rubbers containing epoxy groups, and specific crosslinkers, which no longer require use of conventional crosslinkers, more particularly sulphur. The vulcanizates producible therefrom possess very good compression sets at room temperature, 100 C. and 150 C., and additionally exhibit high tensile strength combined with good elongation at break.

There are provided novel vulcanizable compositions based on optionally fully or partly hydrogenated nitrile rubbers containing epoxy groups, and specific crosslinkers, which no longer require use of conventional crosslinkers, more particularly sulphur. The vulcanizates producible therefrom possess very good compression sets at room temperature, 100 C. and 150 C., and additionally exhibit high tensile strength combined with good elongation at break.

Monomers, polymers and copolymers are provided that incorporate at least one naturally occurring phenolic compound, such as a plant phenol.

Monomers, polymers and copolymers are provided that incorporate at least one naturally occurring phenolic compound, such as a plant phenol.

The process for producing photochromic optical materials of the present invention includes a step (i) of reacting at least one polymerizable monomer (A) having two or more ethylene-based unsaturated groups with at least one polythiol (B) having two or more mercapto groups to obtain a prepolymer; a step (ii) of mixing the prepolymer and a photochromic compound (C) to obtain a polymerizable composition; and a step (iii) of polymerizing the polymerizable composition, wherein, before the reaction of the step (i), the molar number of the mercapto groups included in the polythiol (B) is smaller than the molar number of the ethylene-based unsaturated groups included in the polymerizable monomer (A).

The present invention provides methylene beta-ketoester monomers, methods for producing the same, and compositions and products formed therefrom. In the method for producing the methylene beta-ketoesters of the invention, a beta-ketoester is reacted with a source of formaldehyde in a modified Knoevenagel reaction optionally in the presence of an acidic or basic catalyst, and optionally in the presence of an acidic or non-acidic solvent, to form reaction complex. The reaction complex may be an oligomeric complex. The reaction complex is subjected to further processing, which may be vaporization by contact with an energy transfer means in order to isolate the beta-ketoester monomer. The present invention further compositions and products formed from methylene beta-ketoester monomers of the invention, including monomer-based products (e.g., inks, adhesives, coatings, sealants or reactive molding) and polymer-based products (e.g., fibers, films, sheets, medical polymers, composite polymers and surfactants).

A fluorine-containing resin composition of the present invention includes: a fluorine-containing resin; and a solvent in which the fluorine-containing resin is dissolved. The solvent is a perfluoroalkene. The fluorine-containing resin includes a fluorine-containing polymer including a structural unit (A) represented by the following formula (1).

##STR00001##

(In the formula (1), R.sub.ff.sup.1 to R.sub.ff.sup.4 each independently represent a fluorine atom, a perfluoroalkyl group having 1 to 7 carbon atoms, or a perfluoroalkyl ether group having 1 to 7 carbon atoms. R.sub.ff.sup.1 and R.sub.ff.sup.2 are optionally linked to form a ring.)