Polyurethane resin-forming composition for membrane-sealing material, and membrane and membrane module using same

A polyurethane resin-forming composition for a membrane-sealing material, comprising:

• an allophanate group-containing polyisocyanate prepolymer (A′);
• and
• a curing agent (B), wherein
• the allophanate group-containing polyisocyanate prepolymer (A′) comprises a reaction product of
• a diphenylmethane diisocyanate (a1-1), and
• an active hydrogen-containing compound (a2),
• the curing agent (B) comprises
• a castor oil polymerized polyol (b1),
• at least one polyol (b2) selected from the group consisting of castor oil and a castor oil-modified polyol, and
• a hydroxyl group-containing amine-based compound (b3) other than the castor oil polymerized polyol (b1) and the polyol (b2),
• the castor oil polymerized polyol (b1) comprises a castor oil polymerization product which is a homopolymer of a castor oil,
• a crosslinking group density of the polyurethane resin-forming composition for a membrane-sealing material is 0.65 mmol/g or more with respect to a total mass of the allophanate group-containing polyisocyanate prepolymer (A′) and the curing agent (B), and
• a content of the hydroxyl group-containing amine-based compound (b3) in the curing agent (B) is 5 mass % or more and 30 mass % or less.

A polyurethane resin-forming composition for a membrane-sealing material, comprising:

• an allophanate group-containing polyisocyanate prepolymer (A′);
• and
• a curing agent (B), wherein
• the allophanate group-containing polyisocyanate prepolymer (A′) comprises a reaction product of
• a diphenylmethane diisocyanate (a1-1), and
• an active hydrogen-containing compound (a2),
• the curing agent (B) comprises
• a castor oil polymerized polyol (b1),
• at least one polyol (b2) selected from the group consisting of castor oil and a castor oil-modified polyol, and
• a hydroxyl group-containing amine-based compound (b3) other than the castor oil polymerized polyol (b1) and the polyol (b2),
• the castor oil polymerized polyol (b1) comprises a castor oil polymerization product which is a homopolymer of a castor oil,
• a content of the castor oil polymerization product is 1 mass % or more and 35 mass % or less with respect to a total amount of the allophanate group-containing polyisocyanate prepolymer (A′) and the curing agent (B) and
• a content of the hydroxyl group-containing amine-based compound (b3) in the curing agent (B) is 5 mass % or more and 30 mass % or less.