Vinyl alcohol polymer, aqueous solution, coating agent, ink jet recording material, thermal recording material and base paper for release paper containing same
Provided is a vinyl alcohol polymer that provides a coating film having superior water resistance and binder performances, and has sufficient solubility in water and viscosity stability even in a neutral pH region. Further provided are an aqueous solution, a coating agent, an ink jet recording material, a thermal recording material and a base paper for a release paper that comprise the vinyl alcohol polymer, and a method for producing same, and the like. The vinyl alcohol polymer includes a monomer unit represented by the following formula (1), with the following inequality (I) being satisfied. Preferably, the following inequalities (II) and (III) are further satisfied according to the PVA: wherein, P represents the viscosity average degree of polymerization; and S represents the content (mol %) of the monomer unit.
1. A vinyl alcohol polymer, comprising a monomer unit represented by formula (1):
wherein:
X represents a direct bond, a divalent hydrocarbon group, or a divalent organic group having an oxygen atom or a nitrogen atom;
R 1 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms;
R 2 represents an alkoxyl group, an acyloxyl group or a group represented by OM, wherein M represents a hydrogen atom, an alkali metal or an ammonium group;
R 3 and R 4 each independently represent a hydrogen atom or an alkyl group, wherein hydrogen atoms included in the alkyl group, the alkoxyl group and the acyloxyl group represented by R 1 to R 4 are unsubstituted or substituted with a substituent having an oxygen atom or a nitrogen atom;
R 5 represents a hydrogen atom or a methyl group;
m is an integer of 0 to 2; and
n is an integer of 6 to 20,
wherein in a case where R 1 to R 5 are each present in a plurality of number, a plurality of R 1 s are each independently as defined above, a plurality of R 2 s are each independently as defined above, a plurality of R 3 s are each independently as defined above, a plurality of R 4 s are each independently as defined above, and a plurality of R 5 s are each independently as defined above,
and inequalities (I), (II), and (III) are satisfied:
370 ≦P×S≦ 6,000 (I)
200 ≦P≦ 4,000 (II)
0.1 ≦S≦ 10 (III);
wherein:
P represents a viscosity average degree of polymerization of the vinyl alcohol polymer; and
S represents a percentage content (mol %) of the monomer unit.
2. The vinyl alcohol polymer according to claim 1 , wherein:
X in formula (1) is represented by —CO—NR 6 —*;
R 6 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms;
* denotes a binding site on a side where a Si atom is included in formula (1); and
n is an integer of 6 to 12.
3. An aqueous solution, comprising water and the vinyl alcohol polymer according to claim 1 in an amount of 4% by mass or more and 20% by mass or less, and having a pH of 4 or higher and 8 or lower.
4. A coating agent, comprising:
at least one of water and a non-aqueous solvent, and
the vinyl alcohol polymer according to claim 1 .
5. An ink jet recording material, comprising the vinyl alcohol polymer according to claim 1 .
6. A thermal recording material, comprising the vinyl alcohol polymer according to claim 1 .
7. A base paper for a release paper, the base paper comprising the vinyl alcohol polymer according to claim 1 .
8. The vinyl alcohol polymer according to claim 1 , wherein X represents a direct bond.
9. The vinyl alcohol polymer according to claim 1 , wherein X represents a divalent hydrocarbon group selected from the group consisting of a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms and a divalent aromatic hydrocarbon group having 6 to 10 carbon atoms.
10. The vinyl alcohol polymer according to claim 1 , wherein X represents a divalent organic group having an oxygen atom or a nitrogen atom selected from the group consisting of an ether group, an ester group, a carbonyl group, an amide group, a group derived by linking an ether group, an ester group, a carbonyl group, or an amide group with a divalent hydrocarbon group, an imino group, an amide group, and a group derived by linking an imino group or an amide group with a divalent hydrocarbon group.
11. The vinyl alcohol polymer according to claim 1 , wherein 400≦P×S≦3,000, 500≦P≦3,000 and 0.25≦S≦6.
12. The vinyl alcohol polymer according to claim 1 , wherein 500≦P×S≦2,000, 1,000≦P≦2,400 and 0.5≦S≦5.
13. The vinyl alcohol polymer according to claim 11 , wherein X represents a direct bond, a divalent hydrocarbon group selected from the group consisting of a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms and a divalent aromatic hydrocarbon group having 6 to 10 carbon atoms, or a divalent organic group having an oxygen atom or a nitrogen atom selected from the group consisting of an ether group, an ester group, a carbonyl group, an amide group, a group derived by linking an ether group, an ester group, a carbonyl group, or an amide group with a divalent hydrocarbon group, an imino group, an amide group, and a group derived by linking an imino group or an amide group with a divalent hydrocarbon group.
14. The vinyl alcohol polymer according to claim 12 , wherein X represents a direct bond, a divalent hydrocarbon group selected from the group consisting of a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms and a divalent aromatic hydrocarbon group having 6 to 10 carbon atoms, or a divalent organic group having an oxygen atom or a nitrogen atom selected from the group consisting of an ether group, an ester group, a carbonyl group, an amide group, a group derived by linking an ether group, an ester group, a carbonyl group, or an amide group with a divalent hydrocarbon group, an imino group, an amide group, and a group derived by linking an imino group or an amide group with a divalent hydrocarbon group.