Ethylene-vinylalcohol copolymer aqueous solution

Patent metadata

Field	Value
Publication number	US-11414563-B2
Application number	US-201816771399-A
Country	US
Kind code	B2
Filing date	Dec 11, 2018
Priority date	Dec 12, 2017
Publication date	Aug 16, 2022
Grant date	Aug 16, 2022

Abstract

The present invention provides an aqueous solution containing an ethylene-vinyl alcohol copolymer (A), an alcohol (B) having 1 to 4 carbon atoms and water (C), wherein an ethylene unit content of the ethylene-vinyl alcohol copolymer (A) is 1 mol % or more and less than 20 mol %; a crystallinity in water Cw (30° C.) at 30° C. and a crystallinity in water Cw (70° C.) at 70° C. as determined by pulse NMR satisfy Formula (I); the ethylene-vinyl alcohol copolymer (A) is contained in 0.1 to 100 parts by mass based on 100 parts by mass of water (C); and the alcohol (B) is contained in 0.01 to 30 parts by mass based on 100 parts by mass of water (C). Thus, there is provided an aqueous solution of an ethylene-vinyl alcohol copolymer, which forms a less number of lumps and generates a reduced amount of fibrillar precipitate even when a shear stress is applied.4≤100-Cw⁡(30⁢°⁢⁢C.)100×[Cw⁡(30⁢°⁢⁢C.)-Cw⁡(70⁢°⁢⁢C.)]≤22(I)

First claim

The invention claimed is:

1. An aqueous solution comprising:
an ethylene-vinyl alcohol copolymer (A),
an alcohol (B) having 1 to 4 carbon atoms, and
water (C),
wherein
an ethylene unit content of the ethylene-vinyl alcohol copolymer (A) is 1 mol % or more and less than 20 mol %;
a crystallinity in water Cw (30° C.) at 30° C. and a crystallinity in water Cw (70° C.) at 70° C. as determined by pulse NMR satisfy Formula (I);
the ethylene-vinyl alcohol copolymer (A) is contained in 0.1 to 100 parts by mass based on 100 parts by mass of water (C); and
the alcohol (B) is contained in 0.01 to 30 parts by mass based on 100 parts by mass of water (C)

4
≤

1
⁢
0
⁢
0

-

Cw
⁡

(

30
⁢
°
⁢

⁢

C
.

)

100

×

[

Cw
⁡

(

30
⁢
°
⁢

⁢

C
.

)

-

Cw
⁡

(

70
⁢
°
⁢

⁢

C
.

)

]

≤
22.

(
I
)

2. The aqueous solution according to claim 1 , wherein the alcohol (B) is a monohydric alcohol having 1 to 4 carbon atoms.

3. The aqueous solution according to claim 1 , wherein the ethylene-vinyl alcohol copolymer (A) has a viscosity-average polymerization degree of 200 to 5000.

4. The aqueous solution according to claim 1 , wherein the ethylene-vinyl alcohol copolymer (A) has a saponification degree of 80 to 99.99 mol %.

Assignees

• Kuraray Co

Inventors

• Morikawa Keisuke
• Tanida Tatsuya

Classifications

• C09D123/08

  Copolymers of ethene (C09D123/16 takes precedence) · CPC title

• C09D129/04 Primary

  Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids · CPC title

• C08F210/02

  Ethene · CPC title

• C08L29/04

  Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids · CPC title

• C09D7/63

  organic · CPC title