A resin formulation is provided. The resin formulation includes carboxy anhydride at 100 parts by weight, first diisocyanate having the following formula (I) at 20-90 parts by weight, second diisocyanate having the following formulas (II), (III) or a combination thereof at 45-103 parts by weight, and bismaleimide (BMI) at 50-200 parts by weight. A resin polymer and a composite material including the resin polymer are also provided. ##STR00001## In formulas (I), (II) and (III), A includes benzene or cyclohexane, Q includes C1-C12 alkylene, O, S or SO.sub.2, X includes H, CH.sub.3 or CH.sub.2CH.sub.3, R.sub.1 includes H, CH.sub.3 or CH.sub.2CH.sub.3, and E includes H, CH.sub.3 or CH.sub.2CH.sub.3.

There are provided an adhesive for a solar-cell back sheet having an excellent curing rate and being capable of exhibiting excellent adhesive performance by short-term aging, and also a polyol composition used for the adhesive, a solar-cell back sheet using the adhesive, and a solar-cell module using the sheet. The adhesive for a solar-cell back sheet contains, as essential components, at least one hydroxyl group-containing resin (A) selected from a polyester polyurethane polyol (A1), a polyester polyol (A2), a hydroxyl group-containing (meth)acrylic resin (A3), and a hydroxyl group-containing fluorocarbon resin (A4), a polyisocyanate (B), and a cyclic amide compound (C).

Provided are gel particles each having a three-dimensional crosslinked structure having at least one bond selected from a urethane bond and a urea bond, the gel particles each including: a maleimide group represented by Formula 1 below, a photosensitive composition, an ink composition, a method of producing water dispersion of gel particles, and an image forming method. In Formula 1, R.sub.1 and R.sub.2 each independently represent a hydrogen atom or an alkyl group, R.sub.1 and R.sub.2 may be bonded to each other to form a ring, and * represents a bonding site.

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A shape-memory self-healing polymeric network (SMSHP) is useful as a molded part, a coating, or as a matrix for a composite that can be repaired by heating to a controlled temperature. The SMSHP has thermally reversible repeating units where a thermally reversible adduct is situated between two common linking units formed during a polymerization process between thermally reversible monomers and cross-linking monomers. Optionally, other repeating units can be present from other monomers. Shape-memory results when the SMSHP is warmed to a temperature in excess of its glass transition temperature and self-healing then proceeds when a higher temperature is achieved where thermally reversible adducts dissociates to complementary groups that subsequently reform the adduct without distortion of the memorized shape. The thermally reversible adducts can be Diels-Alder (DA) adducts in a polyurethane, poly urea, or amine epoxy SMSHP network.