公开(公告)号：US20210230314A1

公开(公告)日：2021-07-29

申请号：US17059566

申请日：2019-05-29

申请人： KURARAY CO., LTD.

发明人： Naoto Nishida ,  Kazuyuki Somemiya

IPC分类号： C08F2/06 ,  C08F218/08 ,  C08F210/02 ,  C08F2/01

摘要： A method of continuously producing an ethylene-vinyl acetate copolymer in a polymerization vessel containing a reaction liquid containing ethylene, vinyl acetate, a polymerization initiator and methanol, the polymerization vessel being connected via piping to a heat exchanger circulating a coolant, the method includes the steps of: supplying ethylene, the polymerization initiator and methanol to the polymerization vessel; introducing pressurized gas containing ethylene present in a gas phase portion of the polymerization vessel into the heat exchanger; supplying vinyl acetate cooled to between −50° C. and 23° C. to an upper portion of the heat exchanger; flowing vinyl acetate down in the heat exchanger while absorbing ethylene; letting vinyl acetate dissolving ethylene out of a bottom portion of the heat exchanger and adding to the reaction liquid in the polymerization vessel; and taking the reaction liquid out of the polymerization vessel. This provides a method of efficiently removing heat during polymerization of an ethylene-vinyl acetate copolymer.

公开(公告)号：US20230257491A1

公开(公告)日：2023-08-17

申请号：US18003775

申请日：2021-06-30

申请人： KURARAY CO., LTD.

发明人： Yasutaka Inubushi ,  Keishi Hachiya ,  Masaki Kato ,  Yoshikazu Yamasaki ,  Makoto Okamoto ,  Kazuyuki Somemiya ,  Takafumi Izawa

IPC分类号： C08F16/06 ,  C07C69/15 ,  C08F18/08 ,  C08F8/12

CPC分类号： C08F16/06 ,  C07C69/15 ,  C08F18/08 ,  C08F8/12

摘要： [Problem to be solved] To provide a traceable vinyl acetate, a polymer containing the vinyl acetate, and a vinyl alcohol polymer which is a saponified product of the polymer.
[Solution] Vinyl acetate having a ratio of carbon-14 to total carbon of 1.0×10−4 or more, a vinyl acetate polymer containing the vinyl acetate as a monomer unit and a vinyl alcohol polymer obtained by saponifying the vinyl acetate polymer.

公开(公告)号：US11535685B2

公开(公告)日：2022-12-27

申请号：US17059566

申请日：2019-05-29

申请人： KURARAY CO., LTD.

发明人： Naoto Nishida ,  Kazuyuki Somemiya

IPC分类号： C08F2/06 ,  C08F2/01 ,  C08F210/02 ,  C08F218/08 ,  C08K5/00

摘要： A method of continuously producing an ethylene-vinyl acetate copolymer in a polymerization vessel containing a reaction liquid containing ethylene, vinyl acetate, a polymerization initiator and methanol, the polymerization vessel being connected via piping to a heat exchanger circulating a coolant, the method includes the steps of: supplying ethylene, the polymerization initiator and methanol to the polymerization vessel; introducing pressurized gas containing ethylene present in a gas phase portion of the polymerization vessel into the heat exchanger; supplying vinyl acetate cooled to between −50° C. and 23° C. to an upper portion of the heat exchanger; flowing vinyl acetate down in the heat exchanger while absorbing ethylene; letting vinyl acetate dissolving ethylene out of a bottom portion of the heat exchanger and adding to the reaction liquid in the polymerization vessel; and taking the reaction liquid out of the polymerization vessel. This provides a method of efficiently removing heat during polymerization of an ethylene-vinyl acetate copolymer.