公开(公告)号：US20230226520A1

公开(公告)日：2023-07-20

申请号：US18000970

申请日：2021-06-07

Applicant: KURARAY CO., LTD.

Inventor： Takumi TAKAYAMA ,  Kazuhiko MAEKAWA ,  Kazutoshi MISHIMA

IPC: B01J20/26 ,  C08F297/02 ,  B01J20/28 ,  A61L15/24 ,  A23L3/3517

CPC classification number: B01J20/264 ,  C08F297/026 ,  B01J20/28016 ,  A61L15/24 ,  A23L3/3517 ,  A01K1/0155

Abstract: A block copolymer (A) including a vinyl alcohol-based polymer block (b) and an ionic polymer block (c) containing a monomer unit with an ionic group forming a salt and a vinyl alcohol-based monomer unit. The ionic group is a carboxylic acid group, a sulfonic acid group, or an ammonium group. The vinyl alcohol-based polymer block (b) has a number-average molecular weight (Mnb) from 15,000 to 220,000. The ionic polymer block (c) has a content of the vinyl alcohol-based monomer unit from 5 to 95 mol % based on the total monomer units. The block copolymer (A) has a number-average molecular weight (MnA) from 20,000 to 440,000. A ratio (Mnb/MnA) of the number-average molecular weight (Mnb) to the number-average molecular weight (MnA) is from 0.1 to 0.9.

公开(公告)号：US20220267499A1

公开(公告)日：2022-08-25

申请号：US17623105

申请日：2020-06-25

Applicant: KURARAY CO., LTD.

Inventor： Takumi TAKAYAMA ,  Kazutoshi MISHIMA ,  Hiroyuki KONISHI ,  Kazuhiko MAEKAWA

IPC: C08F293/00 ,  C08F4/70 ,  C08L53/00

Abstract: Disclosed is a vinyl alcohol-based block copolymer that is a block copolymer composed of a vinyl alcohol-based polymer block (B-b) and a copolymer block (B-c) comprising a vinyl alcohol-based monomer unit and an acrylic acid-based monomer unit, wherein a content (Z) of the acrylic acid-based monomer unit relative to all monomer units is 0.05 to 20.0 mol %, the block copolymer has a saponification degree of 80 to 99.99 mol %, the block copolymer has a number-average molecular weight (Mna) of 20,000 to 440,000, the block copolymer has a molecular weight distribution (Mwa/Mna) of 1.05 to 1.95, and a ratio (DPb/DPa) of a number-average polymerization degree (DPb) of the vinyl alcohol-based polymer block (B-b) to the number-average polymerization degree (DPa) of the block copolymer is 0.010 to 0.999. The copolymer has a fine balance derived from the copolymer block (B-c) of having a superior solubility in water while being unlikely to undergo thickening or gelation due to pH fluctuation, and also has high mechanic strength derived from the vinyl alcohol-based polymer block (B-b).