Hitachi Chemical Company, Ltd.

Shizuo Sakamoto

Susumu Konii

Masatoshi Yoshida

Yukio Yoshimura

Takehiko Ishibashi

Resol type phenol resins containing scarcely or no phenol mononucleus compounds (monomers) and phenol dinuclei compounds (dimers) and their methylolated derivatives and scarcely containing molecules having an apparent molecular weight of more than 2500 are produced by reacting phenol with formaldehyde in the presence of an alkaline catalyst in a molar ratio of 3.0 to 6.0 moles of formaldehyde and 0.05 to 2.0 moles of the alkaline catalyst per mole of phenol, neutralizing the reaction solution with an acid to pH 4.5 to 6.5 and precipitating the resulting product for separation.

Growing community of inventors

Shimodate, Japan

Shizuo Sakamoto