Patent ID: 8657123

Claim:
A composite semipermeable membrane comprising a separation function layer formed on a microporous supporting membrane, wherein the separation function layer is formed from: (A) a silicon compound in which reactive groups having an ethylenically unsaturated group and a hydrolyzable group are directly bonded to silicon atoms, and (B) a compound that does not contain silicon having an ethylenically unsaturated group and a phosphonic, phosphoric or sulfonic acid group in the form of an acid, ester, metal salt or anhydride, or a carboxylic group in the form of an acid, metal salt or anhydride, and wherein the hydrolyzable group of the silicon compound (A) undergoes condensation, and the ethylenically unsaturated group of the silicon compound (A) and the ethylenically unsaturated group of the compound (B) undergo polymerization.