JP2980253B2 - Polyvinyl alcohol polymer and polyvinyl ester polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyvinyl alcohol polymer having an ethylenic double bond in a side chain having excellent reactivity and a polyvinyl ester polymer having an ethylenic double bond in a side chain having excellent reactivity. About coalescence.

[0002]

2. Description of the Related Art Hitherto, many attempts to introduce an ethylenic double bond into polyvinyl alcohol have been proposed. For example, a method based on a reaction between a hydroxyl group of polyvinyl alcohol and an epoxy compound having a double bond such as glycidyl methacrylate, and a method based on a reaction between a carboxyl group of carboxyl group-modified polyvinyl alcohol and glycidyl (meth) acrylate are exemplified. However,
In the conventional method, since the reaction conditions for obtaining a polyvinyl alcohol-based polymer having an ethylenic double bond in the side chain are extreme, polymerization occurs at the ethylenic double bond portion or the polyvinyl alcohol is decomposed. Thus, no industrially useful polyvinyl alcohol-based polymer having an ethylenic double bond in a side chain has been found. In addition, no industrially useful polyvinyl ester-based polymer having an ethylenic double bond in the side chain has been found at all.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyvinyl alcohol polymer having a double bond in a highly reactive side chain and a highly reactive side chain which do not have the above-mentioned problems. An object of the present invention is to provide a polyvinyl ester polymer having a double bond.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a polyvinyl alcohol-based polymer containing a structural unit represented by the following chemical formula (3) or (4) and A polyvinyl ester polymer containing a structural unit represented by Chemical Formula 3 or Chemical Formula 4 was found, and the present invention was completed.

Embedded image

Embedded image

The polyvinyl alcohol-based polymer of the present invention has a structural unit represented by the above formula (3) or (4) in an amount of 0.1 to 3
It is a polyvinyl alcohol-based polymer containing 0 mol%, a saponification degree of 50 mol% or more, and a polymerization degree of 10 or more. The structural unit is represented by Chemical Formula 3 or Chemical Formula 4, among which Chemical Formula 3
The structural unit represented by is more preferable. R ¹ is hydrogen or a methyl group. R ² is hydrogen or an alkyl group having 1 to 4 carbon atoms, and among them, hydrogen or a methyl group is preferable. R ³ is hydrogen or an alkyl group having 1 to 3 carbon atoms, and among them, hydrogen or a methyl group is preferable. R ⁴
Is an alkylene group having 1 to 3 carbon atoms, and preferably has a small carbon number.

(X) in the structural unit is a linking group represented by (X ₁ ) linked to the carbon forming the double bond on the ester bond side, and linked to the carbon forming the double bond on the R ⁷ side. It is a linking group represented by (X ₂ ) or a linking group represented by (X ₃ ) linked to a carbon constituting a double bond on the O side. R ⁵ in (X ₁ ) is an alkylene group having 1 to 20 carbon atoms which may have a branch, and among them, an alkylene group having 1 to 12 carbon atoms is preferable, and an alkylene group having 1 to 6 carbon atoms is preferable. More preferably, an alkylene group having 1 to 3 carbon atoms is more preferable, and an alkylene group having 1 carbon atom is most preferable. R ⁶ and R ⁷ in (X ₂ ) each have 1 to 10 carbon atoms.
Of these, an alkylene group having 1 to 5 carbon atoms is preferable, an alkylene group having 1 to 3 carbon atoms is more preferable, and an alkylene group having 1 carbon atom is most preferable. R ⁶ in (X ₃ ) is an alkylene group having 1 to 10 carbon atoms, preferably an alkylene group having 1 to 5 carbon atoms, more preferably an alkylene group having 1 to 3 carbon atoms, and an alkylene group having 1 carbon atom. Groups are most preferred.

[0007] The content of the structural unit having an ethylenic double bond in the polyvinyl alcohol-based polymer of the present invention is 0.1 to 30 mol%, and among them, 0.2 to 20 mol%.
Mol% is preferable, and 0.5 to 15 mol% is more preferable. When the content of the structural unit is less than 0.1 mol%,
The characteristics as a polyvinyl alcohol-based polymer containing an ethylenic double bond in the side chain are not sufficiently exhibited. If the content of the structural unit exceeds 30 mol%, the characteristics inherent in the present invention such as toughness and good water solubility of the polyvinyl alcohol are lost, and the characteristics of the present invention are not sufficiently exhibited.

The degree of saponification of the vinyl ester portion of the polyvinyl alcohol polymer of the present invention is at least 50 mol%, preferably at least 70 mol%, more preferably at least 98 mol%. A higher saponification degree is preferred from the viewpoint of the film strength and water solubility of the polyvinyl alcohol-based polymer. In the polyvinyl ester polymer of the present invention, examples of unsaponified vinyl ester units include vinyl ester units composed of vinyl formate, vinyl acetate, vinyl propionate, vinyl pivalate, vinyl versatate and the like. Vinyl units are preferred from the point of industrial production. The polymerization degree of the polyvinyl alcohol-based polymer of the present invention is 10 or more, preferably 10 to 30,000,
100-4000 is more preferable, and 300-3000 is the most preferable. Here, the degree of polymerization is determined by the intrinsic viscosity ([η], dl /
g unit) in water at 30 ° C., and calculated using the formula represented by the following equation 1.

(Equation 1)

Next, the polyvinyl ester polymer of the present invention will be described. The polyvinyl ester-based polymer of the present invention contains 0.1 to 30 mol% of a structural unit having an ethylenic double bond represented by Chemical Formula 3 or Chemical Formula 4,
It is a polyvinyl ester polymer having a degree of saponification of vinyl ester of less than 50 mol% and a degree of polymerization of 10 or more. The structural unit represented by Chemical Formula 3 or Chemical Formula 4, the content thereof, and the degree of polymerization are the same as those described in the section of the polyvinyl alcohol polymer. The saponification degree of the vinyl ester portion of the polyvinyl ester polymer of the present invention is 50 mol%.
And is appropriately selected depending on the use of the polymer.
For example, when hydrophilicity of the polymer is required, a polymer having a saponification degree of 10 mol% or more and less than 50 mol%, preferably 20 mol% or more and less than 50 mol% is used. In this case, a saponification degree of 0 to 20 mol%, preferably 0 to 10 mol% is used. As the vinyl ester unit in the polyvinyl ester polymer of the present invention, the vinyl ester units described in the section of the above polyvinyl alcohol polymer are used.

Next, a method for producing a polyvinyl alcohol-based polymer having an ethylenic double bond in a side chain will be described. The method for producing the polyvinyl alcohol polymer having an ethylenic double bond of the present invention is not particularly limited, but the epoxy ring of the epoxy compound having an ethylenic double bond in the molecule and the amino group of the amino group-modified polyvinyl alcohol And a method of reacting Among the epoxy compounds having an ethylenic double bond in the molecule,
Epoxy compounds having an epoxy ring at one end are preferred. Examples of such an epoxy compound include an epoxy compound represented by the following chemical formula 5.

[0011]

Embedded image

Among the epoxy compounds represented by the above formula 5, glycidyl (meth) acrylate, 2-epoxyethyl (meth) acrylate, 3-epoxypropyl (meth) acrylate, 4-epoxybutyl (meth) acrylate, (Meth) acrylates such as 6-epoxyhexyl (meth) acrylate and 12-epoxydodecyl (meth) acrylate, glycidyl vinyl ether, 2-epoxyethyl vinyl ether, 3-epoxypropyl vinyl ether, 4-epoxybutyl vinyl ether, 6- Vinyl ethers such as epoxyhexyl vinyl ether; glycidyl allyl ether;
Epoxy ethyl allyl ether, 3-epoxypropyl allyl ether, 4-epoxybutyl allyl ether,
Allyl ethers such as 6-epoxyhexyl allyl ether are preferred in terms of reactivity. Among these epoxy compounds, methacrylic esters are particularly preferred in view of economy and reactivity of the obtained polyvinyl alcohol-based polymer.

Examples of the amino group-modified polyvinyl alcohol include polyvinyl alcohol containing a structural unit having a primary amino group or a secondary amino group represented by the following chemical formula (6) or (7).

Embedded image

Embedded image An amino group content of 0.1 to 30 mol% is preferably used. The saponification degree of the amino group-modified polyvinyl alcohol is 50 mol% or more, preferably 70 mol%, and most preferably 98 mol% or more. The degree of polymerization of the amino group-modified polyvinyl alcohol is appropriately selected depending on the intended use of the intended polyvinyl alcohol-based polymer having an ethylenic double bond in a side chain. As a method for producing an amino group-modified polyvinyl alcohol, Japanese Industrial Chemistry Magazine Vol. 59,
658 (1956), 60, 353, 1188
Page (1957), JP-A-56-113292, JP-A-62-74902, etc., or by an olefinically unsaturated monomer having a primary amino group or a secondary amino group or by hydrolysis. Examples include a method of copolymerizing an olefinically unsaturated monomer having a substituent capable of forming a primary amino group or a secondary amino group with vinyl acetate and then saponifying the copolymer. Specific examples include a method of saponification after copolymerizing vinylacetamide, methylvinylacetamide and vinyl acetate, and a method of saponification after copolymerizing allylamine and vinyl acetate. The amino group-modified polyvinyl alcohol used in the present invention may have another functional group other than the amino group as long as the object of the present invention is not impaired. Examples of such a functional group include a long-chain alkyl group, a silane group, a sulfonic acid group, a carboxyl group, and a quaternary ammonium salt. The reaction may be performed in a homogeneous solution or in a state where PVA is not dissolved. If necessary, a catalyst such as an acid such as formic acid, acetic acid or hydrochloric acid or an alkali such as triethylamine, trimethylamine, pyridine, imidazole or 2-methylimidazole may be added at all.

The reaction between the epoxy ring of the epoxy compound having an ethylenic double bond in the molecule and the amino group of the amino group-modified polyvinyl alcohol is carried out in a solvent such as water, dimethyl sulfoxide or N-methyl-2-pyrrolidone. Will be Among the above solvents, water and dimethyl sulfoxide are preferred. The molar ratio of the amino group of the amino group-modified polyvinyl alcohol to the epoxy compound is 0.1 to 100.
Is preferable, and 1 to 50 are more preferable. The concentration of the amino group-modified polyvinyl alcohol in the solvent is adjusted to about 0.01 to 50% by weight, preferably 1 to 30% by weight when the reaction is performed in a homogeneous solution. Reaction temperature is 0 to 300 ° C
Is preferable, and 30 to 200 ° C. is more preferable. The reaction time is preferably from 0.01 to 200 hours, more preferably from 0.5 to 100 hours. The obtained polyvinyl alcohol-based polymer is purified by a conventionally known method.

Next, a method for producing a polyvinyl ester polymer having an ethylenic double bond in a side chain will be described. The method for producing the polyvinyl ester having an ethylenic double bond of the present invention is not particularly limited, but has an ethylenic double bond in the side chain obtained by the above method,
It is obtained by re-esterifying a polyvinyl alcohol polymer having a saponification degree of 50 mol% or more. The re-esterification has an ethylenic double bond and a saponification degree of 50 mol%.
The reaction is carried out by reacting the polyvinyl alcohol polymer with an organic acid such as acetic anhydride and acetyl chloride. At this time, a reaction aid such as pyridine or triethylamine may be added, or the polyvinyl alcohol-based polymer may be dissolved in a solvent such as dimethyl sulfoxide or acetic acid, and the reaction may be performed under a uniform solution. There is no particular limitation on the charge ratio between the polyvinyl alcohol polymer and the organic acid,
Organic acid 0.1 to 1 g of polyvinyl alcohol-based polymer.
It is appropriately selected from the range of 1 to 50 g, preferably 1 to 30 g according to the degree of saponification of the target polyvinyl ester polymer. The reaction temperature is preferably from 0 to 300 ° C,
~ 200 ° C is more preferred. Reaction time is 0.01-20
0 hours is preferable, and 1 to 100 hours is more preferable. In performing the above-mentioned re-esterification, it is preferable to seal with an inert gas such as nitrogen. The obtained polyvinyl ester polymer is purified by a conventionally known method.

[0016]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples.
In the following, “parts” or “%” means “parts by weight” or “% by weight”, respectively, unless otherwise specified. Example 1 In the structural unit represented by Chemical Formula 6, R ¹ = H, R ²
= CH ₃ , containing 3 mol% of structural units and having a degree of saponification of 9
Amino group-modified polyvinyl alcohol having a molecular weight of 9.9 mol% and a degree of polymerization of 2,000 (units other than the amino group-containing structural unit and vinyl alcohol unit are vinyl acetate units. The same applies to the following Example 2 and the like) 150 g of dimethyl sulfoxide. The mixture was added, heated at 90 ° C., and dissolved by stirring. After the amino group-modified polyvinyl alcohol was dissolved, 82 g of glycidyl methacrylate and 1.6 g of triethylamine were added, and the mixture was reacted at 90 ° C. After 9 hours from the start of the reaction, the stirring was stopped, the reaction solution was poured into a large amount of acetone, the polymer was reprecipitated, washed sufficiently, and then vacuum-dried to obtain a polyvinyl alcohol containing a structural unit having an ethylenic double bond. A polymer (hereinafter abbreviated as polymer [A]) was obtained. The ¹ H-NMR spectrum (measured by JGS, Model GSX-270, manufactured by JEOL Ltd., using the same apparatus) of the amino group-modified polyvinyl alcohol measured in D ₂ O is shown in FIG. . FIG.
In the spectrum, the peak at δ 1.5 to 1.8 ppm indicates a methylene group, the peak at δ 2.5 ppm indicates an N-methyl group, and the peak at δ 4.0 ppm indicates a methine group. Further, ¹ H- of the polymer [A] measured in D ₂ O was used.
The NMR spectrum is shown in FIG.

In the spectrum of FIG. 2, δ 1.5 to 1.8
The peak at ppm is a methylene group, the peaks at 2.73 ppm and 2.92 ppm are N-methyl groups, and δ = 4.
The peak at 0 ppm indicates a methine group, and the peaks at 5.34 ppm and 5.65 ppm indicate a methylene group in an ethylenic double bond. The peaks at δ 5.34 ppm and δ 5.65 ppm confirmed that an ethylenic double bond was present. From FIG. 2, the amino group conversion of the amino group-modified polyvinyl alcohol was 50%, and the content of the structural unit having an ethylenic double bond was 1.5 mol%. Further, the degree of saponification of the polymer [A] was 99.9 mol%, and the degree of polymerization was 1980.

COMPARATIVE EXAMPLE 1 150 g of polyvinyl alcohol having a saponification degree of 99.9 mol% and a polymerization degree of 1750 was mixed with dimethyl sulfoxide 485.
0 g, heated at 90 ° C., and dissolved by stirring. After dissolving the polyvinyl alcohol, glycidyl methacrylate 8
2 g was added and the reaction was carried out at 90 ° C. 9 hours after the start of the reaction, the stirring was stopped, and the reaction solution was poured into a large amount of acetone.
The polymer was reprecipitated and sufficiently washed, and then dried under vacuum to obtain a polyvinyl alcohol-based polymer (hereinafter abbreviated as polymer [B]). The ¹ H-NMR spectrum of the polymer [B] measured in D ₂ O is shown in FIG. In the spectrum of FIG. 3, the peak at δ 1.5 to 1.8 ppm indicates a methylene group, and the peak at δ 4.0 ppm indicates a methine group. Since no peaks are observed at δ 5.3 ppm and 5.6 ppm, it is clear that the polymer [B] does not contain an ethylenic double bond.

Example 2 In the structural unit represented by the above formula 6, R ¹ ＣＨCH ₃ ,
10 g of an amino-modified polyvinyl alcohol containing 20 mol% of a structural unit of R ² = C ₂ H _{5 and} having a saponification degree of 88.5 mol% and a polymerization degree of 1000 was added to 190 g of N-methyl-2-pyrrolidone. And dissolved by stirring. After the amino group-modified polyvinyl alcohol was dissolved, 25 g of glycidyl methacrylate and 0.5 g of triethylamine were added, and the reaction was performed at 90 ° C. Reaction start 3
After a lapse of time, the stirring is stopped, the reaction solution is poured into a large amount of acetone, the polymer is reprecipitated and sufficiently washed, and then dried under vacuum to remove one structural unit having an ethylenic double bond.
A polyvinyl alcohol polymer containing 5 mol%, a saponification degree of 88.4 mol% and a polymerization degree of 960 was obtained.

Example 3 In the structural unit represented by the above formula 6, R ¹ = H, R ²
100 g of an amino group-modified polyvinyl alcohol containing 5.3 mol% of a structural unit of ＣＨCH _{3 and} having a saponification degree of 52.0 mol% and a polymerization degree of 4000 was added to 900 g of dimethyl sulfoxide, and heated at 90 ° C. to dissolve with stirring. did. After the amino group-modified polyvinyl alcohol was dissolved, 100 g of 4-ethoxybutyl methacrylate and 5 g of triethylamine were added, and the reaction was performed at room temperature. 24 hours after the start of the reaction, stirring was stopped, the reaction solution was poured into a large amount of acetone, the polymer was reprecipitated, washed sufficiently, and then dried under vacuum to obtain a structural unit having an ethylenic double bond.
A polyvinyl alcohol polymer containing 5 mol%, a saponification degree of 52.0 mol% and a polymerization degree of 4000 was obtained.

Example 4 In the structural unit represented by the above formula 6, R ¹ = H and R ² =
50 g of an amino group-modified polyvinyl alcohol having a structural unit of C ₃ H ₇ of 1.0 mol%, a saponification degree of 72.3 mol% and a degree of polymerization of 2,000 was added to dimethyl sulfoxide 45.
0 g, heated at 90 ° C., and dissolved by stirring. After the amino group-modified polyvinyl alcohol was dissolved, 18 g of glycidyl acrylate and 0.2 g of triethylamine were added, and the reaction was performed at 90 ° C. After 2 hours from the start of the reaction, stirring was stopped, the reaction solution was poured into a large amount of acetone, the polymer was reprecipitated, washed sufficiently, and then dried under vacuum to obtain 0.95 mol of a structural unit having an ethylenic double bond. %, And a polyvinyl alcohol-based polymer having a saponification degree of 72.1 mol% and a polymerization degree of 1970 was obtained.

Example 5 In the structural unit represented by the above formula 7, R ¹ = H, R ²
= H, R ⁴ = C ₃ H ₆ , containing 10.0 mol% of a structural unit having a saponification degree of 99.9 mol% and a polymerization degree of 20 were added to 10 g of an amino group-modified polyvinyl alcohol to 490 g of dimethyl sulfoxide. The mixture was heated at ℃ and dissolved by stirring. After the amino group-modified polyvinyl alcohol is dissolved, 5 g of glycidyl methacrylate and 0.1 g of triethylamine are dissolved.
1 g was added and the reaction was carried out at 90 ° C. After 3 hours from the start of the reaction, the stirring was stopped, and the reaction solution was poured into a large amount of acetone.
The polymer was reprecipitated, sufficiently washed, and then dried under vacuum to obtain a structural unit having an ethylenic double bond of 4.8.
Mol%, a saponification degree of 99.9 mol% and a polymerization degree of 2.
0 was obtained.

Example 6 In the structural unit represented by the above formula 6, R ¹ = H, R ²
= CH ₃ , 10 g of amino-modified polyvinyl alcohol having a saponification degree of 99.9 mol% and a degree of polymerization of 2000 was immersed in 10 g of methanol, and 5 g of glycidyl methacrylate was added. The reaction was carried out. Twelve hours after the start of the reaction, the reaction solution was washed with a large amount of acetone and then dried under vacuum to contain 2.0 mol% of a structural unit having an ethylenic double bond, a saponification degree of 99.9 mol% and a polymerization degree of 1990. Was obtained.

Example 7 In the structural unit represented by the above formula 7, R ¹ = H and R ² =
Containing 5 mol% of a structural unit in which CH ₃ and R ⁴ = CH ₂ ;
5 g of an amino group-modified polyvinyl alcohol having a saponification degree of 99.9 mol% and a polymerization degree of 30 was added to dimethyl sulfoxide 2
The mixture was heated at 90 ° C. and dissolved by stirring. After dissolving the amino group-modified polyvinyl alcohol, 50 g of 15-epoxypentadecyl acrylate and 1 g of pyridine
Was added and the reaction was carried out at 90 ° C. After 12 hours from the start of the reaction, stirring was stopped, the reaction solution was poured into a large amount of acetone, the polymer was reprecipitated, sufficiently washed, and then dried under vacuum to obtain 3.8 mol of the structural unit having an ethylenic double bond. %, A saponification degree of 99.8 mol% and a polymerization degree of 30.
Was obtained.

Example 8 In the structural unit represented by the above formula 6, R ¹ = H and R ² =
It contains 30 mol% of a structural unit of CH ₃ and has a saponification degree of 9
9.8 mol% and 10 g of amino group-modified polyvinyl alcohol having a degree of polymerization of 1750 were added to dimethyl sulfoxide 150
g, heated at 90 ° C., and dissolved by stirring. After the amino group-modified polyvinyl alcohol was dissolved, 30 g of allyl glycidyl ether and 0.5 g of triethylamine were added, and the reaction was carried out at 90 ° C. After 9 hours from the start of the reaction, the stirring was stopped, the reaction solution was poured into a large amount of acetone, the polymer was reprecipitated, washed sufficiently, and then vacuum-dried to obtain 25 mol% of the structural unit having an ethylenic double bond. A polyvinyl alcohol polymer having a saponification degree of 99.7 mol% and a polymerization degree of 1,720 was obtained.

Example 9 Polyvinyl alcohol-based polymer 10 obtained in Example 1
g was immersed in 160 g of acetic anhydride, and 4 g of pyridine was added, followed by stirring at 105 ° C. for 24 hours. The obtained reaction product was sufficiently washed with distilled water, and dried under vacuum at 50 ° C., so that a structural unit having an ethylenic double bond was 1.5 to 1.5 times.
Mol%, saponification degree 0 mol% and polymerization degree 1980
Was obtained.

Example 10 5 g of the polyvinyl alcohol-based polymer obtained in Example 6
Was immersed in 40 g of acetic anhydride and dried at 90 ° C. for 12 hours. The obtained reaction product is sufficiently washed with distilled water and dried under vacuum at 50 ° C. to contain 2.0 mol% of a structural unit having an ethylenic double bond, a saponification degree of 30 mol%, and polymerization. A polyvinyl ester polymer having a degree of 1990 was obtained.

[0028]

The polyvinyl alcohol polymer having an ethylenic double bond in the side chain of the present invention has an ethylenic double bond, so that a cross-linking reaction can easily occur or other monomers can be easily grafted. In addition to having characteristics such as reacting, it also has hydrophilicity and toughness inherent to polyvinyl alcohol. Polyvinyl alcohol polymer having an ethylenic double bond in the side chain of the present invention,
Taking advantage of these features, fiber, film, photosensitive resin,
It is extremely useful for printing plate materials, sizing agents, paper coating agents, adhesives, dispersion stabilizers for suspension polymerization, dispersion stabilizers for emulsion polymerization, dispersants, butyral resins, sponges, and the like. Furthermore, the method of the present invention for producing a polyvinyl alcohol-based polymer having an ethylenic double bond in a side chain can be carried out under relatively mild conditions, and does not cause side reactions such as decomposition of the polyvinyl alcohol-based polymer. Since it can provide a novel polymer having characteristics and reactivity and hydrophilicity, its industrial significance is great.

Further, the polyvinyl ester polymer having an ethylenic double bond in the side chain of the present invention has an ethylenic double bond, so that a cross-linking reaction easily occurs or another monomer easily graft-reacts. In addition to these features, it also has lipophilicity inherent to polyvinyl ester and dimensional stability at room temperature. The polyvinyl ester polymer having an ethylenic double bond in the side chain of the present invention, taking advantage of these characteristics, is extremely useful in applications such as paints, adhesives, dispersants, photosensitive resins, fiber treatment agents, and paper sizes. Useful. Further, the polyvinyl alcohol-based polymer having an ethylenic double bond in the side chain of the present invention exhibits extremely excellent water resistance due to polymerization with another monomer or photocrosslinking.

[Brief description of the drawings]

FIG. 1 shows a ¹ H-NMR spectrum of an amino group-modified polyvinyl alcohol used in Example 1.

FIG. 2 shows ¹ H- of polymer [A] obtained in Example 1.
3 shows an NMR spectrum.

FIG. 3 shows ¹ H- of polymer [B] obtained in Comparative Example 1.
3 shows an NMR spectrum.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-10104 (JP, A) JP-A-62-256801 (JP, A) JP-A-1-193307 (JP, A) JP-A 62-104 267302 (JP, A) JP-A-62-74902 (JP, A) JP-A-61-211081 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08F 8/00 C08F 8 /14

Claims (5)

(57) [Claims] 1. The structural unit represented by the following chemical formula 1 is 0.1
A polyvinyl alcohol-based polymer having a saponification degree of 50 mol% or more and a polymerization degree of 10 or more, containing from 30 to 30 mol%. Embedded image 2. The structural unit represented by the following chemical formula 2 is 0.1
A polyvinyl alcohol-based polymer having a saponification degree of 50 mol% or more and a polymerization degree of 10 or more, containing from 30 to 30 mol%. Embedded image 3. A polyvinyl ester polymer containing 0.1 to 30 mol% of the structural unit represented by Chemical formula 1 according to claim 1, having a saponification degree of less than 50 mol% and a polymerization degree of 10 or more. 4. A polyvinyl ester polymer containing 0.1 to 30 mol% of the structural unit represented by Chemical formula 2 according to claim 2, having a saponification degree of less than 50 mol% and a polymerization degree of 10 or more. 5. A polyvinyl alcohol having an ethylenic double bond in a side chain, wherein an epoxy ring of an epoxy compound having an ethylenic double bond in the molecule is reacted with an amino group of an amino group-modified polyvinyl alcohol. A method for producing a polymer.