公开(公告)号：US12240794B2

公开(公告)日：2025-03-04

申请号：US17417599

申请日：2019-12-23

Applicant: SHOWA DENKO K.K.

Inventor： Takamitsu Kobayashi ,  Naoyuki Tanaka

IPC: C07C231/12

Abstract: A composition for producing an N-vinylcarboxylic acid amide includes (A) an N-(1-alkoxyethyl)carboxylic acid amide and (B) a carboxylic acid amide other than the N-(1-alkoxyethyl)carboxylic acid amide and the N-vinylcarboxylic acid amide, and satisfies the following conditions: (1) the composition has a melting point of 0 to 30° C.; (2) a water content is 0 to 1.00% by mass in a total amount of the composition; (3) a content ratio of the component (A) to the component (B) is 4.0 to 20.0 in terms of a molar ratio; and (4) a 5% by mass aqueous solution of the composition has a pH of 4.0 to 8.0. A method for producing an N-vinylcarboxylic acid amide includes thermally decomposing or catalytically decomposing the composition for producing an N-vinylcarboxylic acid amide.

公开(公告)号：US12157715B2

公开(公告)日：2024-12-03

申请号：US17614143

申请日：2020-12-23

Applicant: SHOWA DENKO K.K.

Inventor： Takamitsu Kobayashi ,  Naoyuki Tanaka

IPC: C07C231/24

Abstract: A method for producing a highly polymerizable N-vinyl carboxylic acid amide monomer includes (A) melting a crude N-vinyl carboxylic acid amide monomer including 50 to 88 mass % of an N-vinyl carboxylic acid amide monomer by heating, followed by cooling for precipitation, and subjecting precipitated N-vinyl carboxylic acid amide monomer crystals to solid-liquid separation (step (A)), and (B) further dissolving the N-vinyl carboxylic acid amide monomer crystals separated in step (A) in a mixed solvent of 1,2-dimethoxyethane and an aliphatic hydrocarbon having 6 to 7 carbon atoms, then performing crystallization, performing solid-liquid separation, and recovering an N-vinyl carboxylic acid amide monomer purified product (step (B)), wherein a mass ratio of 1,2-dimethoxyethane/N-vinyl carboxylic acid amide monomer crystal in step (B) is 0.01 to 0.5, and a mass ratio of aliphatic hydrocarbon having 6 to 7 carbon atoms/N-vinyl carboxylic acid amide monomer crystal in step (B) is 0.5 to 3.0.

公开(公告)号：US12297162B2

公开(公告)日：2025-05-13

申请号：US17595786

申请日：2020-12-23

Applicant: SHOWA DENKO K.K.

Inventor： Takamitsu Kobayashi ,  Naoyuki Tanaka

IPC: C07C231/24 ,  C07C233/05

Abstract: A method for producing a highly polymerizable N-vinyl carboxylic acid amide monomer includes (A) melting a crude N-vinyl carboxylic acid amide monomer comprising 50 to 88 mass % of an N-vinyl carboxylic acid amide monomer by heating, followed by cooling for precipitation, and subjecting precipitated N-vinyl carboxylic acid amide monomer crystals to solid-liquid separation (step (A)), and (B) further dissolving the N-vinyl carboxylic acid amide monomer crystals separated in step (A) in a mixed solvent of toluene and an aliphatic hydrocarbon having 6 to 7 carbon atoms, then performing crystallization, performing solid-liquid separation, and recovering an N-vinyl carboxylic acid amide monomer purified product (step (B)), wherein a mass ratio of toluene/N-vinyl carboxylic acid amide monomer crystal in step (B) is 0.01 to 0.5, and a mass ratio of aliphatic hydrocarbon having 6 to 7 carbon atoms/N-vinyl carboxylic acid amide monomer crystal in step (B) is 0.5 to 3.0.

公开(公告)号：US12252458B2

公开(公告)日：2025-03-18

申请号：US17614153

申请日：2020-12-23

Applicant: SHOWA DENKO K.K.

Inventor： Naoyuki Tanaka ,  Katsumi Mikami ,  Takamitsu Kobayashi

IPC: C07C231/12 ,  C07C231/24

Abstract: A method for producing a highly polymerizable N-vinyl carboxylic acid amide monomer includes (A) melting a crude N-vinyl carboxylic acid amide monomer comprising 50 to 88 mass % of an N-vinyl carboxylic acid amide monomer by heating, followed by cooling for precipitation, and subjecting precipitated N-vinyl carboxylic acid amide monomer crystals to solid-liquid separation (step (A)), and (B) further dissolving the N-vinyl carboxylic acid amide monomer crystals separated in the step (A) in a mixed solvent of ethyl acetate and an aliphatic hydrocarbon having 6 to 7 carbon atoms, then performing crystallization, performing solid-liquid separation, and recovering an N-vinyl carboxylic acid amide monomer purified product (step (B)), wherein a mass ratio of ethyl acetate/N-vinyl carboxylic acid amide monomer crystal in step (B) is 0.01 to 0.5, and a mass ratio of aliphatic hydrocarbon having 6 to 7 carbon atoms/N-vinyl carboxylic acid amide monomer crystal in step (B) is 0.5 to 3.0.

公开(公告)号：US11718579B2

公开(公告)日：2023-08-08

申请号：US17595783

申请日：2020-12-23

Applicant: SHOWA DENKO K.K.

Inventor： Takamitsu Kobayashi ,  Naoyuki Tanaka

IPC: C07C231/24 ,  C07C233/05

CPC classification number: C07C231/24 ,  C07C233/05 ,  C07C231/24 ,  C07C233/05

Abstract: A method for producing a highly polymerizable N-vinyl carboxylic acid amide monomer includes (A) melting a crude N-vinyl carboxylic acid amide monomer comprising 50 to 88 mass % of an N-vinyl carboxylic acid amide monomer by heating, followed by cooling for precipitation, and subjecting precipitated N-vinyl carboxylic acid amide monomer crystals to solid-liquid separation (step (A)), and (B) further dissolving the N-vinyl carboxylic acid amide monomer crystals separated in step (A) in a mixed solvent of acetonitrile and an aliphatic hydrocarbon having 6 to 7 carbon atoms, then performing crystallization, performing solid-liquid separation, and recovering an N-vinyl carboxylic acid amide monomer purified product (step (B)), wherein a mass ratio of acetonitrile/N-vinyl carboxylic acid amide monomer crystal in step (B) is 0.01 to 0.5, and a mass ratio of aliphatic hydrocarbon having 6 to 7 carbon atoms/N-vinyl carboxylic acid amide monomer crystal in step (B) is 0.5 to 3.0.

公开(公告)号：US11299454B2

公开(公告)日：2022-04-12

申请号：US15999787

申请日：2017-01-16

Applicant: SHOWA DENKO K.K.

Inventor： Naoyuki Tanaka

IPC: C07C231/12 ,  C07C231/24 ,  C07C233/18 ,  B01J21/04 ,  B01J23/42

Abstract: A method for producing an N-vinylcarboxylic acid amide is provided, the method focusing on unsaturated aldehydes that are contained as impurities generated during a reaction. The method for producing an N-vinylcarboxylic acid amide includes a step for controlling the contained amount of unsaturated aldehydes in the N-vinylcarboxylic acid amide to be not more than 20 mass ppm.