Chiyoda Corporation

Nippon Steel Chemical Co., Ltd.

Keiji Shimoda

Nobuo Moriya

Kouji Sakashita

Sachio Asaoka

Hiroaki Nishijima

Nobuhiro Onda

Takeshi Kouzaki

Susumu Yamamoto

Tetsuo Maejima

Makoto Yasui

Katsuhiko Sakura

Makoto Nomura

Toshihiko Furukawa

Nobuyuki Suda

Takao Kameda

Yoshiaki Matsui

Masanori Nagase

Takamasa Minami

Hiroshi Yanai

Tadayoshi Matsuo

Tsohikazu Maruyama

The invention relates to a process for preparing prilled bisphenol A by granulation which comprises adding compounds soluble in molten bisphenol A, not affecting adversely the melt color of bisphenol A to any significant extent, and have a melting point of 60.degree. C. or more to bisphenol A and granulating and also to a process which comprises adding the reaction mother liquor or cyrstallization mother liquor produced in the manufacturing step of bisphenol A to bisphenol A or the adduct of bispheol A and phenol or a mixture of bispheol A and phenol, removing the phenol, and granulating. The processes yield prilled bispheol A which have high strength and resist powdering.

Process for preparing prilled bisphenol A

High purity, crystalline adduct of bisphenol A and phenol is produced multi-stage crystallization of a phenolic slurry of bisphenol A with a crystal separation and washing step being interposed between each of the two stages. Each of the crystallization stage includes a series of crystallization towers operated at decreasing temperatures. The crystallization of the slurry is performed by continuously discharging a portion of the slurry from each of the crystallization towers, introducing the discharged slurry into one or more coolers and then recycling the cooled slurry to the tower. Another portion of the slurry in each crystallization slurry is continuously discharged, heated for dissolving fine crystals of the adduct and then recycled to the crystallization tower so that large crystals are grown in each of the crystallization steps. An apparatus having a plurality of coolers and suitable for effecting the above crystallization is also disclosed.

Process for the production of crystalline adduct of bisphenol A and

Growing community of inventors

Machida, Japan

Keiji Shimoda