Abstract: Disclosed are a pressure-sensitive adhesive composition comprising a reactive mixture of a relatively low molecular weight acrylic prepolymer containing highly reactive hydroxyl groups in the molecule thereof which is obtained by copolymerizing two alkyl acrylate monomers satisfying a specific relationship and, as a chain extender, a polyfunctional isocyanate mainly exhibiting bifunctionality; a pressure-sensitive adhesive composition comprising the above reactive mixture and a relatively high molecular weight polymer component; and pressure-sensitive adhesive sheets having a pressure-sensitive adhesive layer comprising those pressure-sensitive adhesive compositions. Because the molecular chain of the acrylic prepolymer is extended efficiently, the amount of an organic solvent required for viscosity adjustment can be decreased.

Abstract: A pressure-sensitive adhesive composition showing the adhesive force and the cohesive force with a good stability is disclosed. The composition comprises a copolymer of a (meth)acrylic acid alkyl ester (a) having an alkyl group having from 2 to 14 carbon atoms and a (meth)acrylic acid alkyl ester (b) having a carboxyl group or a hydroxyl group at the terminal end and having an alkyl group having from 3 to 14 total carbon atoms as the ester side chain. In particular, when the carbon atom number of the alkyl group of the monomer (b) is less by one than or not less than the same number as the carbon atom number of the alkyl group of the monomer (a), the effect of the functional group can be most effectively exhibited. A pressure-sensitive adhesive tape or sheet is also disclosed, comprising a support having formed at least one surface thereof the pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition.

Abstract: An acid chloride, bicyclo 2,2,2!oct-7ene-(2.alpha.,3.beta.,5.alpha.,6.beta.)tetracarbonyl chloride (C.sub.12 H.sub.8 O.sub.4 Cl.sub.

Abstract: A composite reverse osmosis membrane comprising a thin membrane and a microporous supporting membrane supporting it, wherein said thin membrane mainly comprises a crosslinked polyamide comprising; (a) an amine component containing at least one member selected from the group consisting of substantially monomeric amine compounds each having at least two primary and/or secondary amino groups, and (b) an acid halide component containing at least one member selected from the group consisting of substantially monomeric cyclic acid halide compounds each having at least two acid halide groups and comprising at least two rings.