Modified polyvinyl alcohol, resin composition, and film

Patent metadata

Field	Value
Publication number	US-10414836-B2
Application number	US-201815976893-A
Country	US
Kind code	B2
Filing date	May 11, 2018
Priority date	Oct 9, 2014
Publication date	Sep 17, 2019
Grant date	Sep 17, 2019

Abstract

A modified PVA that enables formation of a film superior in cold water solubility, mechanical strength, and chemical resistance is provided. The modified PVA comprises a monomer unit represented by formula (I), and a structural unit represented by formula (II):

wherein: a content of the monomer unit (I) is from 0.05 mol % to 10 mol %, and a content of the structural unit (II) is from 0.001 mol % to 0.5 mol % with respect to the total monomer units in the modified PVA; a viscosity average degree of polymerization is from 300 to 3,000; and a degree of saponification is from 82 mol % to 99.5 mol %. In the formula (I): R 1 represents a hydrogen atom, or a methyl group; and R 2 represents —R 3 —SO 3 − X + , —R 3 —N + (R 4 ) 3 Cl − , or a hydrogen atom, R 3 representing an alkanediyl group, X + representing a hydrogen atom, a metal atom, or an ammonium group, and R 4 representing an alkyl group.

First claim

The invention claimed is:

1. A packaging material comprising a film comprising a modified polyvinyl alcohol, wherein said film has a cold water solubility, in terms of a time period required for a 40 mm×40 mm square of said film to be completely dissolved in 10° C. water, of less than 45 sec for a 50 μm thick film, the modified polyvinyl alcohol comprising a monomer unit represented by formula (I), and a structural unit represented by formula (II):

wherein in the formula (I),
R 1 represents a hydrogen atom, or a linear or branched alkyl group having 1 to 8 carbon atoms, and
R 2 represents —R 3 —SO 3 − X + , —R 3 —N + (R 4 ) 3 Cl − , or a hydrogen atom,
R 3 representing a linear or branched alkanediyl group having 1 to 10 carbon atoms,
X + representing a hydrogen atom, a metal atom, or an ammonium group, and
R 4 representing a linear or branched alkyl group having 1 to 5 carbon atoms, wherein a plurality of R 4 s are identical or different; and

wherein in the formula (II),
R 5 represents a hydrogen atom, or a linear or branched alkyl group having 1 to 8 carbon atoms,

wherein:
a percentage content of the monomer unit represented by the formula (I) with respect to total monomer units in the modified polyvinyl alcohol is 0.05 mol % or greater and 10 mol % or less;
a percentage content of the structural unit represented by the formula (II) with respect to the total monomer units in the modified polyvinyl alcohol is 0.001 mol % or greater and 0.5 mol % or less;
a viscosity average degree of polymerization of the modified polyvinyl alcohol is 300 or greater and 3,000 or less;
a degree of saponification of the modified polyvinyl alcohol is 82 mol % or greater and 99.5 mol % or less; and
the modified polyvinyl alcohol is a saponified product of a copolymer consisting essentially of a vinyl ester monomer and a monomer that provides the monomer unit represented by formula (I).

2. The packaging material according to claim 1 , wherein in the formula (I) R 1 represents a hydrogen atom.

3. The packaging material according to claim 1 , wherein in the formula (I) R 1 represents a linear or branched alkyl group having 1 to 8 carbon atoms.

4. The packaging material according to claim 1 , wherein in the formula (I) R 2 represents —R 3 —SO 3 − X + where X + is a hydrogen atom.

5. The packaging material according to claim 1 , wherein in the formula (I) R 2 represents —R 3 —SO 3 − X + where X + is a metal atom.

6. The packaging material according to claim 1 , wherein in the formula (I) R 2 represents —R 3 —SO 3 − —X + where X + is an ammonium group.

7. The packaging material according to claim 1 , wherein in the formula (I) R 2 represents —R 3 —N + (R 4 ) 3 Cl − .

8. The packaging material according to claim 1 , wherein in the formula (I) R 2 represents a hydrogen atom.

9. The packaging material according to claim 1 , wherein in the formula (II) R 5 represents a hydrogen atom.

10. The packaging material according to claim 1 , wherein in the formula (II) R 5 represents a linear or branched alkyl group having 1 to 8 carbon atoms.

11. The packaging material according to claim 1 , wherein the percentage content of the monomer unit represented by the formula (I) with respect to total monomer units in the modified polyvinyl alcohol is 0.15 mol % or greater and 7 mol % or less.

12. The packaging material according to claim 1 , wherein the percentage content of the structural unit represented by the formula (II) with respect to the total monomer units in the modified polyvinyl alcohol is 0.10 mol % or greater and 0.5 mol % or less.

13. The packaging material according to claim 1 , wherein the percentage content of the structural unit represented by the formula (II) with respect to the total monomer units in the modified polyvinyl alcohol is 0.20 mol % or greater and 0.5 mol % or less.

14. The packaging material according to claim 1 , wherein the degree of saponification is 82 mol % or greater and 95 mol % or less.

15. The packaging material according to claim 1 , wherein the percentage of content of the monomer unit represented by the formula (I) with respect to total monomer units in the modified polyvinyl alcohol is 0.15 mol % or greater and 3.0 mol % or less.

16. The packaging material according to claim 1 wherein said film further comprises a saccharide.

17. The packaging material according to claim 1 wherein said film further comprises a plasticizer.

18. The packaging material according to claim 1 and wherein said film further comprises an inorganic filler.

19. The packaging material according to claim 1 , wherein the modified polyvinyl alcohol is a saponified product of a copolymer consisting of the vinyl ester monomer and the monomer that provides the monomer unit represented by formula (I).

20. A packaging material comprising a modified polyvinyl alcohol, the modified polyvinyl alcohol comprising a monomer unit represented by formula (I), and a structural unit represented by formula (II):

wherein in the formula (I),
R 1 represents a hydrogen atom, or a linear or branched alkyl group having 1 to 8 carbon atoms, and
R 2 represents —R 3 —SO 3 − X + , —R 3 —N + (R 4 ) 3 Cl − , or a hydrogen atom,
R 3 representing a linear or branched alkanediyl group having 1 to 10 carbon atoms,
X + representing a hydrogen atom, a metal atom, or an ammonium group, and
R 4 representing a linear or branched alkyl group having 1 to 5 carbon atoms, wherein a plurality of R 4 s are identical or different; and

wherein in the formula (II),
R 5 represents a hydrogen atom, or a linear or branched alkyl group having 1 to 8 carbon atoms,

wherein:
a percentage content of the monomer unit represented by the formula (I) with respect to total monomer units in the modified polyvinyl alcohol is 0.05 mol % or greater and 10 mol % or less;
a percentage content of the structural unit represented by the formula (II) with respect to the total monomer units in the modified polyvinyl alcohol is 0.001 mol % or greater and 0.5 mol % or less;
a viscosity average degree of polymerization of the modified polyvinyl alcohol is 300 or greater and 3,000 or less;
a degree of saponification of the modified polyvinyl alcohol is 82 mol % or greater and 99.5 mol % or less;
the modified polyvinyl alcohol is a saponified product of a copolymer consisting essentially of a vinyl ester monomer and a monomer that provides the monomer unit represented by formula (I);
the packaging material optionally further comprises at least one of a saccharide, a plasticizer, and an inorganic filler, and
said packaging material is in the form of a film having an average thickness of 10 μm-200 μm, a tensile breaking strength of 2.0 kg/cm 2 -5.0 kg/cm 2 , and a Young's modulus of 2.0 kg/mm 2 -5.0 kg/mm 2 .

21. A packaging material comprising a modified polyvinyl alcohol, the modified polyvinyl alcohol comprising a monomer unit represented by formula (I), and a structural uni

Assignees

• Kuraray Co

Inventors

• Takafuji Masahiro
• Kato Masaki
• Mori Yoko

Classifications

• C08F220/585

  and containing other heteroatoms, e.g. 2-acrylamido-2-methylpropane sulfonic acid [AMPS] · CPC title

• C08F8/16

  Lactonisation · CPC title

• C08J5/18

  Manufacture of films or sheets · CPC title

• C08J2329/04

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

• C09D129/04

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