Title:
PRESSURE CRYSTALLIZATION AND SEPARATION METHOD OF CRYSTAL POLYMORPHOUS SUBSTANCE
Document Type and Number:
Japanese Patent JP3198651
Kind Code:
B2
Abstract:
PURPOSE: To improve the purity of a crystal product by melting a high pressure phase crystal which worked as a core, growing and increasing low pressure phase crystal after seed crystal of the low pressure phase crystal is formed, and carrying out solid-liquid separation in the region.
CONSTITUTION: A raw material mixture is kept in higher pressure condition than the high pressure phase crystal core forming pressure to make and form crystal core of high pressure phase crystal once. Then, the pressure in the mixture system is decreased to the pressure lower than the core forming pressure of the high pressure phase crystal and higher than the high melting pressure of the low pressure phase crystal to melt the high pressure phase crystal and at the same time to make and grow the low pressure phase crystal. Afterward, the pressure of the mixture system is controlled to be within a pressure range higher than the melting pressure of the low pressure phase crystal and lower than the core forming pressure of the high pressure phase crystal to control the crystal amount of the low pressure phase crystal. Almost all liquid is separated and removed in the pressure range.
Inventors:
Nobuhiko Nishiguchi
Satoshi Nishida
Nobuyuki Imanishi
Masato Moritoki
Satoshi Nishida
Nobuyuki Imanishi
Masato Moritoki
Application Number:
JP23058192A
Publication Date:
August 13, 2001
Filing Date:
August 28, 1992
Export Citation:
Assignee:
KABUSHIKI KAISHA KOBE SEIKO SHO
International Classes:
C07C51/43; B01D9/02; C07C57/12; (IPC1-7): B01D9/02; C07C51/43
Attorney, Agent or Firm:
Kyuichi Ueki