Ho 250

Example 16

N-butyl methacrylate (Kyoeisha Chemical Co., Ltd., Light Ester NB) 240 parts, 110 parts of hydroxyethyl methacrylate (Kyoeisha Chemical Co., Ltd., Light Ester HO-250) and 30 parts of styrene were mixed to prepare a monomer mixture solution, and 25 parts of 2,2′-azobis (2,4-dimethylvaleronitrile) (Wako Pure Chemical Industries, V-65) as an initiator was dissolved in an aromatic hydrocarbon (T-SOL 100) to prepare an initiator solution. Aromatic hydrocarbon (T-SOL 100) 250 parts and 250 parts of propylene glycol monomethyl ether acetate were placed in a stirrable flask, and the monomer solution and the initiator solution were added dropwise while nitrogen was enclosed. The polymerization temperature at this time was 100° C. The dropwise addition was carried out for 2 hours, and further aging was carried out at 100° C. for 4 hours to obtain a polymer solution J.

Example 13

2-ethylhexyl methacrylate 145 parts, 145 parts of monomer B, 150 parts of hydroxyethyl methacrylate (Kyoeisha Chemical Co., Ltd., Light Ester HO-250), and 120 parts of styrene were mixed to prepare a monomer mixture solution, and 25 parts of 2,2′-azobis (2,4-dimethylvaleronitrile) (Wako Pure Chemical Industries, V-65) as an initiator was dissolved in an aromatic hydrocarbon (T-SOL 100) to prepare an initiator solution.

Aromatic hydrocarbon (T-SOL 100) 250 parts and 250 parts of propylene glycol monomethyl ether acetate were placed in a stirrable flask, and the monomer solution and the initiator solution were added dropwise while nitrogen was enclosed. The polymerization temperature at this time was 100° C. The dropwise addition was carried out for 2 hours, and further aging was carried out at 100° C. for 4 hours to obtain a polymer solution G.