JP7075775B2 - Method for Producing Modified Vinyl Alcohol Polymer - Google Patents

Description

The present invention relates to a method for producing a modified vinyl alcohol polymer. More specifically, the present invention relates to a method for producing a modified vinyl alcohol-based polymer having an unsaturated hydrocarbon group in the side chain.

Since vinyl alcohol-based polymers have excellent interfacial properties and strength properties as one of the few crystalline hydrophilic polymers, they are used as stabilizers for paper processing, fiber processing and emulsions. On the other hand, pursuit of high functionality by controlling crystallinity and introducing functional groups to improve specific performance has also been pursued, and various so-called modified vinyl alcohol polymers have been developed.

Among them, the modified vinyl alcoholic polymer having an unsaturated hydrocarbon group in the side chain has various functions derived from the unsaturated hydrocarbon group such as cross-linking property between the side chains by high energy rays such as UV light and electron beam. It can be applied to an alcohol-based polymer. Several methods for producing the modified vinyl alcohol polymer have been proposed. As such a production method, for example, a method of introducing an unsaturated hydrocarbon group by reacting a hydroxyl group of a vinyl alcohol-based polymer with an aldehyde compound having an unsaturated hydrocarbon group and acetalizing the polymer (Patent Document 1). , A method of reacting a hydroxyl group of a vinyl alcohol-based polymer with an epoxy compound having an unsaturated hydrocarbon group (Patent Document 2), reacting a hydroxyl group of a vinyl alcohol-based polymer with a vinyl ester compound having an unsaturated hydrocarbon group. Examples thereof include a method of reacting a polyvinyl alcohol with (meth) acrylate in the presence of an acid catalyst or a base catalyst (Patent Document 4).

Japanese Unexamined Patent Publication No. 2009-108305 Japanese Patent Application Laid-Open No. 2003-231715 WO2007 / 23762 Gazette Japanese Unexamined Patent Publication No. 2007-63383

However, in the production methods described in Patent Documents 1 and 2, many of the epoxy compounds and aldehyde compounds having unsaturated hydrocarbon groups are mutable, and in recent years, the safety awareness of chemical substances has increased and the environmental load has increased. It has become a problem in the background of dealing with the above, and alternative technology has been sought.

On the other hand, the production method described in Patent Document 3 is not versatile in the vinyl ester compound used as a raw material, and in order to introduce various structures, it is necessary to establish an industrial production method for the corresponding vinyl ester compound, which is economical. Its implementation is limited from a practical point of view. Furthermore, it was also a problem that highly toxic acetaldehyde, which is a tautomer of vinyl alcohol, was produced as a by-product as the reaction proceeded. Further, in the production method described in Patent Document 4, since the reaction is carried out in a solution, isolation of the reaction product is complicated, safety is high, and a method capable of more easily producing a modified vinyl alcohol polymer is desired. It was rare.

The present invention has been made to solve the above problems, and is unsaturated in the side chain in which an ester compound that is industrially easily available and has low toxicity can be used as a raw material and the product can be easily isolated. It is an object of the present invention to provide a method for producing a modified vinyl alcohol-based polymer having a hydrocarbon group.

As a result of diligent studies to solve the above problems, the present inventors have found that when the ester compound represented by the formula (1) described later is used as a raw material in the production of a modified vinyl alcohol-based polymer, the vinyl alcohol-based weight is used. When the Fedors solubility parameter of the coalescence and the Hydrocarbon solubility parameter of the solvent satisfy a specific relationship, the ester exchange reaction proceeds even when the vinyl alcohol-based polymer is not dissolved and dispersed, and the reaction product, which is a reaction product, is not present in the side chain. We have found that a modified vinyl alcohol-based polymer having a saturated hydrocarbon group can be easily isolated, and completed the present invention.

［式（１）中、Ｒ^１、Ｒ^２およびＲ^３は、それぞれ独立して水素原子、置換基を有していてもよい脂肪族炭化水素基、置換基を有していてもよい脂環式炭化水素基、または置換基を有していてもよい芳香族炭化水素基を表す。Ｘは、置換基を有していてもよい２価の脂肪族炭化水素基、置換基を有していてもよい２価の脂環式炭化水素基、または置換基を有していてもよい２価の芳香族炭化水素基を表す。ｎは０～１０の整数を表す。Ｒ^４は、置換基を有していてもよい飽和脂肪族炭化水素基、置換基を有していてもよい脂環式炭化水素基、または置換基を有していてもよい芳香族炭化水素基を表す。］
［２］前記ビニルアルコール系重合体が有する水酸基の量が１０～２３ｍｍｏｌ／ｇである、［１］の製造方法；
［３］前記ビニルアルコール系重合体がポリビニルアルコールである、［１］または［２］の製造方法；
［４］前記溶媒１００質量部あたりの有機物（Ａ）の含有量が１０～６０質量部である、［１］～［３］のいずれかの製造方法；
［５］前記ビニルアルコール系重合体が、平均粒子径５０～１０００μｍの粒子である、［１］～［４］のいずれかの製造方法；
［６］前記ビニルアルコール系重合体が、比表面積０．１～１．０ｍ^２／ｇの粒子である、［１］～［５］のいずれかの製造方法；
を提供することにより解決される。 That is, according to the present invention, the above-mentioned problem is solved.
[1] The vinyl alcohol-based polymer is an organic substance (A) having a Hildebrand solubility parameter δ _A of 10 to 15 (hereinafter, may be referred to as an organic substance (A)) and an ester represented by the following formula (1). A method for producing a modified vinyl alcohol-based polymer, which is _dispersed in a solvent containing a compound (hereinafter, may be referred to as an ester compound (1)) and reacted. A method for producing a modified vinyl alcohol-based polymer, wherein the difference in the Fedors solubility parameter δ _-polym (δ _-polym- δ _-solv ) of the vinyl alcohol-based polymer is 2.8 to 6.0;

[In the formula (1), R ¹ , R ² and R ³ independently have a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, and an alicyclic which may have a substituent. Formula Represents an aromatic hydrocarbon group or an aromatic hydrocarbon group which may have a substituent. X may have a divalent aliphatic hydrocarbon group which may have a substituent, a divalent alicyclic hydrocarbon group which may have a substituent, or a substituent. Represents a divalent aromatic hydrocarbon group. n represents an integer from 0 to 10. ^R4 is a saturated aliphatic hydrocarbon group which may have a substituent, an alicyclic hydrocarbon group which may have a substituent, or an aromatic hydrocarbon which may have a substituent. Represents a group. ]
[2] The production method of [1], wherein the amount of hydroxyl groups contained in the vinyl alcohol polymer is 10 to 23 mmol / g;
[3] The method for producing [1] or [2], wherein the vinyl alcohol-based polymer is polyvinyl alcohol;
[4] The production method according to any one of [1] to [3], wherein the content of the organic substance (A) per 100 parts by mass of the solvent is 10 to 60 parts by mass;
[5] The production method according to any one of [1] to [4], wherein the vinyl alcohol-based polymer is particles having an average particle diameter of 50 to 1000 μm;
[6] The production method according to any one of [1] to [5], wherein the vinyl alcohol-based polymer is particles having a specific surface area of 0.1 to 1.0 m ² / g;
Will be resolved by providing.

According to the present invention, a modified vinyl alcohol system having an unsaturated hydrocarbon group in the side chain, which is industrially easily available and can use an ester compound having low toxicity as a raw material and can easily isolate the product. A method for producing a polymer can be provided.

The present invention will be described in detail based on embodiments. The following embodiments do not limit the present invention, and various modifications can be made without impairing the gist of the present invention.

[Vinyl alcohol polymer]
In the production method of the present invention, for example, a vinyl alcohol-based polymer having a number average molecular weight (Mn) of 4,000 to 440,000 is used. Mn is preferably 4,400 or more, more preferably 11,000 or more, and further preferably 22,000 or more from the viewpoint of obtaining a high-strength molded product. On the other hand, if Mn is too high, when an aqueous solution of a modified vinyl alcohol polymer is prepared, the viscosity of the solution may become too high and handling may become difficult, or the dissolution rate may decrease. 220,000 or less is preferable, and 190,000 or less is more preferable.

The amount of hydroxyl groups contained in the vinyl alcohol polymer used in the production method of the present invention is not particularly limited, but is preferably 10 to 23 mmol / g, more preferably 12 to 23 mmol / g, and even more preferably 15 to 23 mmol / g. .. When the amount of the hydroxyl group is within the above range, the reaction rate between the vinyl alcohol-based polymer and the ester compound (1) tends to be faster, and the modified amount of the modified vinyl alcohol-based polymer tends to be sufficient.

In the present invention, the vinyl alcohol-based polymer means a polymer containing vinyl alcohol units, and the content of the vinyl alcohol units is preferably 40 mol% or more, more preferably 40 mol% or more, with all the constituent units in the polymer being 100 mol%. Is 75 mol% or more, more preferably 80 mol% or more, and may be 100 mol% or more. Examples of the vinyl alcohol-based polymer that can be used in the production method of the present invention include polyvinyl alcohol and an ethylene-vinyl alcohol copolymer. Above all, polyvinyl alcohol is preferable from the viewpoint of water solubility of the modified vinyl alcohol polymer. The content of ethylene units in the ethylene-vinyl alcohol copolymer is not particularly limited, but the total constituent units in the polymer are 100 mol%, preferably 60 mol% or less, more preferably 55 mol% or less, still more preferably 50 mol. % Or less, preferably 10 mol% or more, more preferably 15 mol% or more, still more preferably 20 mol% or more.

In the present invention, the vinyl alcohol-based polymer is reacted in a state of being dispersed in a solvent containing an organic substance (A) and an ester compound (1) described later. The shape of the vinyl alcohol-based polymer before being dispersed in the solvent is not particularly limited, but particles having an average particle diameter of 50 to 1000 μm are preferable. When the average particle size is within the above range, the ester compound (1) is likely to diffuse into the vinyl alcohol-based polymer, which is suitable for the progress of the reaction, and the handleability of the obtained modified vinyl alcohol-based polymer is easy to handle. And workability is improved. The average particle size is preferably 100 μm or more, more preferably 200 μm or more, further preferably 300 μm or more, and particularly preferably 400 μm or more. When the average particle size is at least the above lower limit value, the powder is less likely to scatter, and the filterability after the reaction is excellent, and the handleability tends to be excellent. The average particle size is preferably 900 μm or less, more preferably 800 μm or less. When the average particle size is not more than the above upper limit value, the obtained modified vinyl alcohol-based polymer is easily dissolved in water, and thermal crosslinking is easily suppressed. In the present invention, the average particle size means a volume average particle size measured by dispersing a vinyl alcohol-based polymer as a raw material in methanol by using a light scattering method using a laser beam.

In the present invention, the vinyl alcohol-based polymer preferably has a specific surface area of particles of 0.1 to 1.0 m ² / g, more preferably 0.1 to 0.8 m ² / g, and 0. It is more preferably 1 to 0.5 m ² / g. When the specific surface area of the particles is within the above range, the contact interface between the vinyl alcohol-based polymer dispersed in the solvent and the ester compound (1) increases, which is suitable for the reaction progress. When the specific surface area is at least the above lower limit value, the ester compound (1) is likely to diffuse into the vinyl alcohol polymer, and the reaction is likely to proceed. On the other hand, when the specific surface area is not more than the above upper limit value, the water solubility of the obtained modified vinyl alcohol-based polymer tends to be good.

The amount of modification in the modified vinyl alcohol polymer obtained by the present invention (that is, the content of the structural unit modified with the ester compound (1) when the total number of structural units in the modified vinyl alcohol polymer is 100 mol%. ) Is not particularly limited, but is preferably 0.01 mol% or more, more preferably 0.07 mol% or more, still more preferably 0.1 mol% or more, preferably 10 mol% or less, more preferably 8 mol% or less, still more preferably. Is 5 mol% or less. When the amount of modification is at least the above lower limit, the water resistance of the crosslinked product of the modified vinyl alcohol polymer tends to be excellent. On the other hand, when the modification amount is not more than the above upper limit value, the water solubility of the modified vinyl alcohol polymer tends to be good.

The content of the vinyl alcohol unit in the modified vinyl alcohol-based polymer obtained by the present invention is not particularly limited, but from the viewpoint of solubility in water, the total constituent units in the polymer are 100 mol%, preferably 40 mol% or more. It is more preferably 70 mol% or more, further preferably 75 mol% or more, and particularly preferably 80 mol% or more. The content of the vinyl alcohol unit is preferably 99.95 mol% or less, more preferably 99.90 mol% or less, with 100 mol% of all the constituent units in the polymer.

The vinyl alcohol unit can be derived from the vinyl ester unit by hydrolysis, alcohol decomposition, or the like. Therefore, the vinyl ester unit may remain in the vinyl alcohol-based polymer depending on the conditions for converting the vinyl ester unit to the vinyl alcohol unit. Therefore, the vinyl alcohol-based polymer used in the present invention and the obtained modified vinyl alcohol-based polymer may contain vinyl ester units other than the structural unit modified with the ester compound (1).

Examples of the vinyl ester of the vinyl ester unit include vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl versatic acid, vinyl caproate, vinyl caprilate, vinyl laurate, and palmitin. Examples thereof include vinyl acetate, vinyl stearate, vinyl oleate, vinyl benzoate and the like, and among these, vinyl acetate is preferable from an industrial point of view.

The modified vinyl alcohol-based polymer obtained by the present invention may further have a structural unit other than the structural unit modified with the ester compound (1), the vinyl alcohol unit and the vinyl ester unit as long as the effect of the present invention can be obtained. can. The structural unit is, for example, an unsaturated monomer copolymerizable with a vinyl ester and convertible into a structural unit modified with the ester compound (1), or an ethylenically unsaturated material copolymerizable with a vinyl ester. It is a structural unit derived from a monomer or the like. The ethylenically unsaturated monomer is, for example, α-olefins such as ethylene, propylene, n-butene, isobutylene, 1-hexene; acrylic acid and salts thereof; methylacrylic acid, ethyl acrylate, n-propyl acrylate. , Acrylic acid esters such as i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, octadecyl acrylate; methacrylic acid and salts thereof. Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, methacrylic Methacrylic acid esters such as octadecyl acid; acrylamide, N-methylacrylamide, N-ethylacrylamide, N, N-dimethylacrylamide, diacetoneacrylamide, acrylamide propanesulfonic acid and its salts, acrylamidepropyldimethylamine and its salts (eg 4). Class salts); methacrylicamide, N-methylmethacrylicamide, N-ethylmethacrylicamide, methacrylicamide propanesulfonic acid and its salts, methacrylicamide propyldimethylamine and its salts (eg, quaternary salts); methylvinyl ether, ethylvinyl ether, n. -Vinyl ethers such as propyl vinyl ether, i-propyl vinyl ether, n-butyl vinyl ether, i-butyl vinyl ether, t-butyl vinyl ether, dodecyl vinyl ether, stearyl vinyl ether, 2,3-diacetoxy-1-vinyloxypropane; acrylonitrile, methacrylic acid. Vinyl cyanide such as nitrile; vinyl halide such as vinyl chloride and vinyl fluoride; vinylidene halide such as vinylidene chloride and vinylidene fluoride; allyl acetate, 2,3-diacetoxy-1-allyloxypropane, chloride. Allyl compounds such as allyl; unsaturated dicarboxylic acids such as maleic acid, itaconic acid, and fumaric acid and salts thereof or esters thereof; vinylsilyl compounds such as vinyltrimethoxysilane; isopropenyl acetate and the like can be mentioned.

In the modified vinyl alcohol-based polymer obtained by the present invention, the arrangement order of the structural unit modified with the ester compound (1), the vinyl alcohol unit, and any other structural unit is not particularly limited, and is obtained by the present invention. The modified vinyl alcohol-based polymer to be obtained may be any of a random copolymer, a block copolymer, an alternating copolymer and the like.

When the vinyl alcohol-based polymer used in the present invention is polyvinyl alcohol, the viscosity average degree of polymerization of the obtained modified vinyl alcohol-based polymer measured in accordance with JIS K6726 is preferably 100 to 5,000. More preferably, it is 200 to 4,000. When the viscosity average degree of polymerization of the modified vinyl alcohol-based polymer is at least the above upper limit value, the mechanical strength of the film tends to be excellent when it is made into a film. On the other hand, when the viscosity average degree of polymerization is not more than the above upper limit value, industrial production of the modified vinyl alcohol-based polymer tends to be easy.

[Organic matter (A)]
In the production method of the present invention, the solvent contains an organic substance (A) having a Hildebrand solubility parameter δ _A of 10 to 15. The organic substance (A) having the Hidebrand solubility parameter in this range has a high affinity with the vinyl alcohol-based polymer and can efficiently swell the vinyl alcohol-based polymer, so that the solvent contains the organic substance (A). As a result, the ester compound (1) diffuses into the vinyl alcohol-based polymer, and the reaction facilitates. On the other hand, when the solvent does not contain the organic substance (A), the reaction does not proceed. The Hildebrand solubility parameter δ _A of the organic substance (A) is preferably 10.5 or more, more preferably 11 or more, preferably 15 or less, and more preferably 14.8 or less. The Hildebrand solubility parameter δ _A of the organic substance (A) is described in Chapter II P. of PolymerHandBook Fourth Edition (John Wiley & Sons, Inc., 1999). It is described in 688, and the unit is (cal / cm) and the value of ^1/2 is referred to.

Examples of the organic substance (A) include acetonitrile, N, N-dimethylformamide, dimethyl sulfoxide, N, N-dimethylacetamide, 1,4-dioxane, ethyl acetate, dichlorobenzene, diphenyl ether, pyridine, pyrrol, pyrrolidone, and triethylene. Examples thereof include glycol, dibromoethane, acetphenone, acetylpiperidin, acrylonitrile, benzyl alcohol, γ-butyrolactone, ε-caprolactam, cyclopentanone, N, N-diacetylpiperazine, diethylene glycol, diethyl phthalate and the like. Among them, N, N-dimethylformamide, dimethyl sulfoxide, N, N-dimethylacetamide, 1,4-dioxane and the like are preferable, and dimethyl sulfoxide is more preferable. These organic substances (A) may be used alone or in combination of two or more. When two or more types are used in combination, the value obtained by multiplying the Hildebrand solubility parameter of each component by the volume fraction is obtained for all components, and the sum of these is defined as δ _A.

In the production method of the present invention, the content of the organic substance (A) per 100 parts by mass of the solvent used in the reaction is preferably 10 to 60 parts by mass. The content of the organic substance (A) is preferably 20 to 55 parts by mass, more preferably 30 to 50 parts by mass. When the content of the organic substance (A) is at least the above lower limit value, the vinyl alcohol-based polymer tends to swell sufficiently and the reaction proceeds quickly. When the content of the organic substance (A) is not more than the above upper limit value, the vinyl alcohol-based polymer swells appropriately and it becomes easy to maintain the dispersed state, and some vinyl alcohol-based polymers are dissolved. Easy to suppress.

［式（１）中、Ｒ^１、Ｒ^２およびＲ^３は、それぞれ独立して水素原子、置換基を有していてもよい脂肪族炭化水素基、置換基を有していてもよい脂環式炭化水素基、または置換基を有していてもよい芳香族炭化水素基を表す。Ｘは、置換基を有していてもよい２価の脂肪族炭化水素基、置換基を有していてもよい２価の脂環式炭化水素基、または置換基を有していてもよい２価の芳香族炭化水素基を表す。ｎは０～１０の整数を表す。Ｒ^４は、置換基を有していてもよい飽和脂肪族炭化水素基、置換基を有していてもよい脂環式炭化水素基、または置換基を有していてもよい芳香族炭化水素基を表す。］ [Ester compound (1)]
In the present invention, the ester compound represented by the following formula (1) is used.

[In the formula (1), R ¹ , R ² and R ³ independently have a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, and an alicyclic which may have a substituent. Formula Represents an aromatic hydrocarbon group or an aromatic hydrocarbon group which may have a substituent. X may have a divalent aliphatic hydrocarbon group which may have a substituent, a divalent alicyclic hydrocarbon group which may have a substituent, or a substituent. Represents a divalent aromatic hydrocarbon group. n represents an integer from 0 to 10. ^R4 is a saturated aliphatic hydrocarbon group which may have a substituent, an alicyclic hydrocarbon group which may have a substituent, or an aromatic hydrocarbon which may have a substituent. Represents a group. ]

Examples of the aliphatic hydrocarbon group represented by R ¹ , R ² and R ³ independently include an alkyl group, an alkenyl group, an alkynyl group and the like, and examples of the alicyclic hydrocarbon group include a cycloalkyl group and the like. Examples of the aromatic hydrocarbon group include an aryl group and an arylalkyl group.

Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group and a neopentyl group. Examples thereof include a tert-pentyl group, an n-hexyl group, an isohexyl group, a 2-ethylhexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group and an n-decyl group. Examples of the alkenyl group include a vinyl group, an allyl group, a methyl vinyl group, a propenyl group, a butenyl group, a pentenyl group, a hexenyl group, a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, a cyclohexenyl group and the like. Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptanyl group, a cyclooctanyl group, a cyclononanyl group, a cyclodecanyl group, a cycloundecanyl group, a cyclododecanyl group and the like. Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group and the like. Examples of the arylalkyl group include a benzyl group, a 4-methoxybezyl group, a phenethyl group, a diphenylmethyl group and the like.

The above-mentioned aliphatic hydrocarbon group, alicyclic hydrocarbon group and aromatic hydrocarbon group may have a substituent, and the substituent includes, for example, an alkyl group such as a methyl group and an ethyl group; phenyl. Aryl groups such as groups, naphthyl groups, anthryl groups and phenanthryl groups; complex groups such as pyridyl group, thienyl group, frill group, pyrrolyl group, imidazolyl group, pyrazinyl group, oxazolyl group, thiazolyl group, pyrazolyl group, benzothiazolyl group and benzoimidazolyl group. Aromatic ring group; methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group, isopentyloxy group, neopentyloxy group, hexyloxy group , Cyclohexyloxy group, heptyloxy group, octyloxy group, nonyloxy group, decyloxy group, dodecyloxy group and other alkoxy groups; methylthio group, ethylthio group, propylthio group, butylthio group and other alkylthio groups; phenylthio group, naphthylthio group and the like. Arylthio group; trisubstituted silyloxy group such as tert-butyldimethylsilyloxy group, tert-butyldiphenylsilyloxy group; acyloxy group such as acetoxy group, propanoyloxy group, butanoyloxy group, pivaloyloxy group, benzoyloxy group; methoxy Carbonyl group, ethoxycarbonyl group, propoxycarbonyl group, isopropoxycarbonyl group, butoxycarbonyl group, isobutoxycarbonyl group, sec-butoxycarbonyl group, tert-butoxycarbonyl group, pentyloxycarbonyl group, hexyloxycarbonyl group, heptyloxycarbonyl group An alkoxycarbonyl group such as a group and an octyloxycarbonyl group; an alkylsulfinyl group such as a methylsulfinyl group and an ethylsulfinyl group; an arylsulfinyl group such as a phenylsulfinyl group; Sulfonyl group, ethoxysulfonyl group, phenyloxysulphonyl group and other sulfonic acid ester groups; amino group; -NHR ⁵ (R ⁵ is any monovalent substituent); mono-substituted amino group; -NR ⁵ R Di-substituted amino group represented by ⁶ (R ⁵ and R ⁶ are arbitrary monovalent substituents); hydroxyl group; cyano group; nitro group; halogen atom such as fluorine atom, chlorine atom, bromine atom, iodine atom; Such Can be mentioned. Examples of the arbitrary monovalent substituent represented by R ⁵ and R ⁶ independently include an alkyl group, an aryl group, an acetyl group, a benzoyl group, a benzenesulfonyl group, a tert-butoxycarbonyl group and the like. The hydrogen atom of the alkyl group or aryl group in R5 may be further substituted with an acetyl group, a benzoyl group, a benzenesulfonyl group, a tert ^- butoxycarbonyl group or the like.

From the viewpoint of the reactivity of the vinyl alcohol-based polymer and the ester compound (1), R ¹ and R ² have independent hydrogen atoms and aliphatic hydrocarbon groups or substituents which may have substituents, respectively. It is preferably an alicyclic hydrocarbon group which may have, more preferably an aliphatic hydrocarbon group which may independently have a hydrogen atom or a substituent, and is a hydrogen atom. Is even more preferred. As the aliphatic hydrocarbon group which may have a substituent, an alkyl group having 1 to 10 carbon atoms which may have a substituent is preferable, and 1 to 5 carbon atoms are more preferable, and among them, methyl. Groups, ethyl groups, propyl groups, isopropyl groups, butyl groups, isobutyl groups, sec-butyl groups, tert-butyl groups, pentyl groups, isopentyl groups and neopentyl groups are preferable, and methyl groups and ethyl groups are particularly preferable. As the alicyclic hydrocarbon group which may have a substituent, a cycloalkyl group which may have a substituent is preferable, and among them, a cyclopropyl group, a cyclobutyl group and a cyclopentyl group are more preferable.

From the viewpoint of the reactivity of the vinyl alcohol-based polymer and the ester compound (1), R ³ may have a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, or a fat which may have a substituent. It is preferably a cyclic hydrocarbon group, more preferably an aliphatic hydrocarbon group which may have a hydrogen atom or a substituent. As the aliphatic hydrocarbon group which may have a substituent, an alkyl group having 1 to 10 carbon atoms which may have a substituent is preferable, and 1 to 5 carbon atoms are more preferable, and among them, methyl. A group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isopentyl group and a neopentyl group are more preferable, and a methyl group is particularly preferable. Therefore, it is a preferred embodiment of the present invention that R ³ is a hydrogen atom or a methyl group. As the alicyclic hydrocarbon group which may have a substituent, a cycloalkyl group which may have a substituent is preferable, and a cyclopropyl group, a cyclobutyl group and a cyclopentyl group are more preferable.

Examples of the divalent aliphatic hydrocarbon group which may have a substituent represented by X include an alkylene group which may have a substituent and the like, and a divalent which may have a substituent. Examples of the alicyclic hydrocarbon group of the above include a cycloalkylene group which may have a substituent, and examples of the divalent aromatic hydrocarbon group which may have a substituent include a substituent. Examples thereof include an arylene group which may be possessed.

Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group and a decylene group. Examples of the substituent that these alkylene groups may have include the same substituents as those exemplified in the above description regarding R ¹ , R ² and R ³ , and are alkyl groups such as methyl group and ethyl group. Is preferable as an alkylene group which may have a branched structure.
Specific examples thereof include a methylene group, an ethylene group, a 1-methylethylene group, a 2-methylethylene group, a 1,1-dimethylethylene group, a 1,2-dimethylethylene group, a 2,2-dimethylethylene group and 1-. Ethylethylene group, 2-ethylethylene group, propylene group, 1-methylpropylene group, 2-methylpropylene group, 3-methylpropylene group, 1,1-dimethylpropylene group, 1,2-dimethylpropylene group, 2,2 -Dimethylpropylene group, 1,3-dimethylpropylene group, butylene group, 1-methylbutylene group, 2-methylbutylene group, 3-methylbutylene group, 4-methylbutylene group, 1,1-dimethylbutylene group, 2, 2-Dimethylbutylene group, 3,3-dimethylbutylene group, 4,4-dimethylbutylene group, 1,2-dimethylbutylene group, 1,3-dimethylbutylene group, 1,4-dimethylbutylene group, 2,3- Dimethylbutylene group, 2,4-dimethylbutylene group, 3,4-dimethylbutylene group, 1-ethylbutylene group, 2-ethylbutylene group, 3-ethylbutylene group, 4-ethylbutylene group, 1,1-diethylbutylene Group, 2,2-diethylbutylene group, pentylene group, 1-methylpentylene group, 2-methylpentylene group, 3-methylpentylene group, 4-methylpentylene group, 5-methylpentylene group, 1, 1-dimethylpentylene group, 2,2-dimethylpentylene group, 3,3-dimethylpentylene group, 4,4-dimethylpentylene group, 5,5-dimethylpentylene group, 1,2-dimethylpentylene Group, 1,3-dimethylpentylene group, 1,4-dimethylpentylene group, 2,3-dimethylpentylene group, 2,4-dimethylpentylene group, 3,4-dimethylpentylene group, 1-ethyl Pentylene group, 2-ethylpentylene group, 3-ethylpentylene group, 4-ethylpentylene group, 5-ethylpentylene group, 1,1-diethylpentylene group, 2,2-diethylpentylene group, Hexylene group, 1-methylhexylene group, 2-methylhexylene group, 3-methylhexylene group, 4-methylhexylene group, 5-methylhexylene group, 6-methylhexylene group, 1,1- Dimethylhexylene group, 2,2-dimethylhexylene group, 3,3-dimethylhexylene group, 4,4-dimethylhexylene group, 5,5-dimethylhexylene group, 6,6-dimethylhexylene group, 1,2-dimethylhexylene group, 1,3-dimethylhexylene group, 1,4-dime To tylhexylene group, 2,3-dimethylhexylene group, 2,4-dimethylhexylene group, 3,4-dimethylhexylene group, 1-ethylhexylene group, 2-ethylhexylene group, 3-ethyl Xylene group, 4-ethylhexylene group, 5-ethylhexylene group, 6-ethylhexylene group, 1,1-diethylhexylene group, 2,2-diethylhexylene group, heptylene group, 1-methylheptylene group, 2-Methylheptylene group, 3-Methylheptylene group, 4-Methylheptylene group, 5-Methylheptylene group, 6-Methylheptylene group, 7-Methylheptylene group, 1,1-dimethylheptylene group, 2,2-dimethylheptylene group, 3,3-Dimethylheptylene group, 4,4-dimethylheptylene group, 5,5-dimethylheptylene group, 6,6-dimethylheptylene group, 7,7-dimethylheptylene group, 1,2-dimethylheptylene group, 1,3-dimethylheptylene group, 1,4-dimethylheptylene group, 2,3-dimethylheptylene group, 2,4-dimethylheptylene group, 3,4-Dimethylheptylene group, 1-ethylheptylene group, 2-ethylheptylene group, 3-ethylheptylene group, 4-ethylheptylene group, 5-ethylheptylene group, 6-ethylheptylene group, 7-ethylheptylene group, 1,1-diethyl Heptylene group, 2,2-diethylheptylene group, octylene group, 1-methyloctylene group, 2-methyloctylene group, 3-methyloctylene group, 4-methyloctylene group, 5-methyloctyl Lene group, 6-methyloctylene group, 7-methyloctylene group, 8-methyloctylene group, 1,1-dimethyloctylene group, 2,2-dimethyloctylene group, 3,3-dimethyloctylene group , 4,4-Dimethyloctylene group, 5,5-dimethyloctylene group, 6,6-dimethyloctylene group, 7,7-dimethyloctylene group, 8,8-dimethyloctylene group, 1,2- Dimethyloctylene group, 1,3-dimethyloctylene group, 1,4-dimethyloctylene group, 2,3-dimethyloctylene group, 2,4-dimethyloctylene group, 3,4-dimethyloctylene group, 1-ethyloctylene group, 2-ethyloctylene group, 3-ethyloctylene group, 4-ethyloctylene group, 5-ethyloctylene group, 6-ethyloctylene group, 7-ethyloctylene group, 8 -Ethyloctylene group, 1,1-diethyloctylene group, 2,2-diethyloctylene group, nonylene group , Decylene group and the like.

Examples of the cycloalkylene group include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group and the like. Examples of the substituent that these cycloalkylene groups may have include the same substituents as those exemplified in the above description regarding R ¹ , R ² and R ³ , and are alkyl groups such as methyl group and ethyl group. A cycloalkylene group which may have a branched structure is preferable.

Examples of the arylene group include a phenylene group, a naphthylene group, an anthrylene group, a phenanthrylene group, a fluorenylene group and the like. Examples of the substituent that these arylene groups may have include the same substituents as those exemplified in the above description regarding ^R1 , ^R2 and R3 ^, which may contain an alkyl group such as a methyl group or an ethyl group. An arylene group which may have a branched structure is preferable.

n represents an integer of 0 to 10, and n is preferably 0 to 8, more preferably 0 to 5, further preferably 0 to 3, and 0, that is, an ester compound (ester compound). It is particularly preferable that 1) is an α, β-unsaturated ester compound. In general, since the α, β-unsaturated ester compound has high reactivity, the conventional method tends to increase the molecular weight of the vinyl alcohol-based polymer partially modified by the α, β-unsaturated ester compound. On the other hand, the production method of the present invention is particularly useful when using an α, β-unsaturated ester compound because such a high molecular weight increase can be suppressed.

Examples of the saturated aliphatic hydrocarbon group which may have a substituent represented by R ⁴ include an alkyl group having 1 to 10 carbon atoms which may have a substituent and have a substituent. Examples of the alicyclic hydrocarbon group may include a cycloalkyl group which may have a substituent. Of these, a cyclopropyl group, a cyclobutyl group and a cyclopentyl group are preferable. In the present invention, the alcohol represented by R ⁴ OH (R ⁴ is as defined above) is desorbed during the transesterification reaction, but by removing the alcohol from the reaction system, a vinyl alcohol system is used. The reaction between the polymer and the ester compound (1) is promoted. From this point of view, the alcohol represented by R ⁴ OH is preferably a compound having a low boiling point, and as R ⁴ , an alkyl group having 1 to 4 carbon atoms which may have a substituent is preferable, and among them, methyl. Groups, ethyl groups, propyl groups, isopropyl groups, butyl groups, isobutyl groups, sec-butyl groups and tert-butyl groups are more preferable, and methyl groups are particularly preferable.

Examples of the ester compound (1) include methyl methacrylate, methyl acrylate, methyl silicate, methyl crotonate, methyl 3-methyl-3-butenoate, methyl 4-pentate, and 2-methyl-4-pentene. Methyl acid, Methyl 5-hexenoate, Methyl 3,3-dimethyl-4-pentate, Methyl 7-octenoate, Methyl trans-3-pentate, Methyl trans-4-decenoate, 3-Methyl-3-butene Ethyl acid, ethyl 4-pentate, ethyl 2-methyl-4-pentate, ethyl 5-hexenoate, ethyl 3,3-dimethyl-4-pentenate, ethyl 7-octenoate, ethyl trans-3-pentenate , Trans-4-ethyl decenoate, methyl 10-undecenoate and the like are preferably used. From the viewpoint of low toxicity of the ester compound (1), industrial availability, and ease of ester exchange reaction, methyl methacrylate, methyl acrylate, methyl silicate, methyl crotonate, 3-methyl-3-butene Methyl acid, Methyl 4-pentate, Methyl 2-methyl-4-pentate, Methyl 5-hexenoate, Methyl 3,3-dimethyl-4-pentenate, Methyl 7-octenoate, Methyl trans-3-pentate , Trans-4-Methyl decenoate, 10-Methyl undecenoate are preferred, and from the viewpoint of water solubility of the obtained modified vinyl alcoholic polymer and reactivity to high energy rays, methyl methacrylate, methyl acrylate, crotonic acid. Methyl, Methyl 3-methyl-3-butenoate, Methyl 4-pentate, Methyl 2-methyl-4-pentenate, Methyl 5-hexenoate, Methyl 3,3-dimethyl-4-pentenate, 10-Undecenoic acid Methyl is more preferred, and methyl methacrylate, methyl acrylate, methyl 3-methyl-3-butaneate, methyl 3,3-dimethyl-4-pentenate, and methyl 10-undecenoate are even more preferred. These ester compounds (1) may be used alone or in combination of two or more.

The amount of the ester compound (1) added is not particularly limited, but is preferably 0.1 part by mass or more, more preferably 5 parts by mass or more, and preferably 1000 parts by mass or less with respect to 100 parts by mass of the vinyl alcohol polymer. , More preferably 500 parts by mass or less. When the addition amount of the ester compound (1) is at least the above lower limit value, the reaction rate of the ester exchange reaction tends to be excellent, and when it is at least the above upper limit value, the ester compound (1) remaining after the reaction of the ester exchange reaction is removed. It's easy to do.

In the production method of the present invention, the vinyl alcohol-based polymer is reacted in a state of being dispersed in a solvent containing an organic substance (A) and an ester compound (1). At this time, it is necessary that the difference (δ _polym − δ _solve ) between the Hildebrand solubility parameter δ- _solv of the solvent and the Fedors solubility parameter δ- _polym of the vinyl alcohol-based polymer is in the range of 2.8 to 6.0. be. When δ _polym − δ _solve is in the above range, the vinyl alcohol-based polymer swells efficiently with the solvent, so that the ester compound (1) easily diffuses into the vinyl alcohol-based polymer, and at the same time, the reaction facilitates. Since excessive swelling can be suppressed, the modified vinyl alcohol polymer after the reaction has good filterability and can be easily isolated. If the difference between δ _polym and δ _solve is less than 2.8, there are problems that the vinyl alcohol-based polymer is remarkably swollen and cannot maintain the dispersed state, or is partially dissolved. Further, when δ _polym − δ _solve exceeds 6.0, the vinyl alcohol-based polymer does not swell sufficiently, so that there is a problem that the reaction rate decreases. The range of δ _polym − δ _solve is preferably 3.5 or more, more preferably 3.8 or more, preferably 4.5 or less, and more preferably 4.2 or less. Any vinyl alcohol-based polymer and solvent can be combined as long as it is within the above range. The Fedors solubility parameter of the vinyl alcohol polymer used in the present invention was calculated with reference to the Fedors method, which can calculate the solubility parameter from the chemical structure. The calculation method is described in Polymer Engineering Science, 14, p147 (1974).

In the production method of the present invention, the amount of the solvent added is not particularly limited, but is preferably 100 parts by mass or more, more preferably 200 parts by mass or more, and preferably 2000 parts by mass with respect to 100 parts by mass of the vinyl alcohol polymer. Hereinafter, it is more preferably 1000 parts by mass or less. When the amount of the solvent added is at least the above lower limit value, the vinyl alcohol polymer is easily dispersed, and when it is at least the above upper limit value, the mixture can be efficiently stirred and the reactivity is excellent.

In the production method of the present invention, the content of water per 100 parts by mass of the solvent is preferably 5 parts by mass or less, more preferably 2 parts by mass or less, still more preferably 1 part by mass or less, and 0 parts by mass. May be good. When the content of the water is not more than the upper limit, the transesterification reaction is likely to proceed and a sufficient modification amount is likely to be obtained.

[Transesterification reaction catalyst]
In the production method of the present invention, a transesterification reaction catalyst generally used when conducting a transesterification reaction in the field of synthetic organic chemistry may coexist, and it is preferable to coexist. The ester exchange reaction catalyst is not particularly limited, for example, inorganic acids such as hydrochloric acid, sulfuric acid, nitrate and phosphoric acid; organic carboxylic acids such as acetic acid, propionic acid, phthalic acid and benzoic acid; methylsulfonic acid, benzenesulfonic acid, p. -Organic sulfonic acids such as toluene sulfonic acid and trifluoromethane sulfonic acid; organic phosphoric acids such as diethyl phosphate and phenyl phosphate; alkali metal or alkaline earth metal water such as sodium hydroxide, potassium hydroxide and magnesium hydroxide Oxides; alkali metals such as sodium hydrogen carbonate, potassium carbonate, calcium hydrogen carbonate or alkaline earth metal carbonates and hydrogen carbonates; alkalis such as trilithium phosphate, potassium dihydrogen phosphate, sodium pyrophosphate, calcium metaphosphate Phosphates and hydrogen phosphates of metals or alkaline earth metals; borates of alkali metals or alkaline earth metals such as potassium metaborate, sodium tetraborate, magnesium orthoborate; sodium acetate, potassium acetate, benzoic acid Carboxylates of alkali metals or alkaline earth metals such as sodium, magnesium acetate; alkoxide compounds or phenoxides of alkali metals or alkaline earth metals such as lithium ethoxydo, sodium methoxyd, potassium methoxyd, magnesium methoxyd, sodium phenoxide. Compounds; alkali metals such as calcium oxide or alkaline earth metal oxides; ammonia; ammonium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, ammonium carbonate, ammonium hydrogencarbonate, tetramethylammonium methyl Ammonium salts such as carbonate, tetramethylammonium ethyl carbonate, methyltriethylammonium methyl carbonate, methyltri n-butylammonium methyl carbonate, methyltri n-octylmethylcarbonate; tetraphenylphosphonium hydroxide, tetramethylphosphonium hydroxide, tetramethylphosphonium methylcarbonate. , Methyltri n-butylphosphonium ethyl carbonate, phosphonium salts such as methyltri n-octylphosphonium methyl carbonate; primary amines such as n-butylamine, benzylamine, aniline, ethylenediamine; Grade amine; Tertiary such as triethylamine, tri-n-butylamine, N-methyl-N-ethylaniline, 1,4-diazabicyclo [2,2,2] octane, 1,8-diazabicyclo [5,4,0] -7-undecene. Amin ; nitrogen-containing aromatic heterocyclic compounds such as pyridine, picolin, quinoline, imidazole, pyrimidine, N, N-dimethylaminopyridine; cadmium compounds such as cadmium chloride, cadmium oxide, cadmium acetate; tin chloride, tin oxide, Tin compounds such as tin acetate, tin octanoate, tributyl tin, acetylacetone tin (IV) chloride; lead compounds such as lead chloride, lead oxide, lead carbonate, lead tetraacetate; aluminum chloride, aluminum oxide, aluminum acetate, aluminum Aluminum compounds such as alkoxides; zinc chloride, zinc bromide, zinc iodide, zinc oxide, zinc acetate, zinc trifluoroacetate, zinc stearate, zinc nitrate, zinc carbonate, zinc sulfate, zinc acetylacetone (II), trifluoromethane Zinc compounds such as zinc sulfonate (II), zinc 2-tetrafluoroborate, oxo [hexa (trifluoroacetato)] tetrazinc; bismuth compounds such as bismuth chloride, bismuth oxide, bismuth acetate; iron chloride, Iron compounds such as iron oxide, iron acetate, acetylacetone iron (III), N, N'-bis (salicylidene) ethylenediamine iron (II); cobalt chloride, cobalt oxide, cobalt acetate, cobalt stearate, acetylacetone cobalt (II) Cobalt compounds such as copper chloride, copper bromide, copper iodide, copper oxide, copper acetate, acetylacetone copper (II) and the like; chromium chloride, chromium oxide, chromium acetate, acetylacetone chromium (III) and the like. Chromium compounds; molybdenum compounds such as molybdenum chloride, molybdenum oxide, molybdenum acetate, acetylacetone molybdenum (VI) dioxide; manganese compounds such as manganese chloride, manganese oxide, manganese acetate, acetylacetone manganese (II); titanium chloride, titanium oxide , Titanium-based compounds such as titanium acetate, alkoxytitanium, titanium lactate, titanium acetylacetone (VI) oxide; zirconium-based compounds such as zirconium chloride, zirconium oxide, zirconium acetate, zirconium acetylacetone (IV); Hafnium-based compounds such as hafnium acid (IV); lanthanum chloride, Lanthanum compounds such as lanthanum oxide, lanthanum acetate, lanthanum nitrate, lanthanum alkoxide, acetylacetone lanthanum (III), lanthanum trifluoromethanesulfonate (III); germanium compounds such as germanium chloride and germanium oxide; enzymes such as lipase; etc. It is preferably used. Above all, from the viewpoint of smooth progress of the ester exchange reaction in the production method of the present invention and the hue of the obtained modified vinyl alcoholic polymer, inorganic acid, organic carboxylic acid, organic sulfonic acid, organic phosphoric acid, alkali metal or alkaline soil. Alkali metal hydroxides, alkali metal or alkaline earth metal carbonates and hydrogen carbonates, alkali metal or alkaline earth metal phosphates and hydrogen phosphates, alkali metal or alkaline earth metal carboxylates , Alkali metal or alkaline earth metal alkoxide compound or phenoxide compound, ammonium salt, phosphonium salt, aluminum compound, zinc compound, bismuth compound, titanium compound, zirconium compound, lanthanum compound are more preferable, and inorganic acid. , Organic carboxylic acid, organic sulfonic acid, alkali metal or alkaline earth metal hydroxide, alkali metal or alkaline earth metal carbonate and hydrogen carbonate, alkali metal or alkaline earth metal carboxylate, alkali metal Alternatively, alkaline earth metal alkoxide compounds, ammonium salts, zinc-based compounds, titanium-based compounds, zirconium-based compounds, and lanthanum-based compounds are more preferable, and alkali metal or alkaline earth metal carboxylates, ammonium salts, and zinc-based compounds are more preferable. Most preferred.

The amount of the ester exchange reaction catalyst added is not particularly limited, but is preferably 0.01 part by mass or more, more preferably 0.1 part by mass or more, and preferably 30 parts by mass with respect to 100 parts by mass of the vinyl alcohol polymer. Hereinafter, it is more preferably 15 parts by mass or less. When the addition amount of the transesterification reaction catalyst is not less than the above lower limit value, the reaction rate of the transesterification reaction tends to be excellent, and when it is not more than the above upper limit value, the catalyst residue can be easily removed, and the obtained modified vinyl alcohol polymer can be obtained. It tends to have excellent hue and thermal stability.

In the production method of the present invention, the reaction temperature is not particularly limited, but it is desirable to react at a boiling point or higher of the alcohol so that the alcohol desorbed from the ester compound (1) is removed from the reaction system. The reaction temperature is preferably 20 ° C. to 200 ° C., more preferably 30 ° C. to 180 ° C., still more preferably 50 ° C. to 170 ° C., and most preferably 70 to 150 ° C. When the reaction temperature is at least the above lower limit value, the reaction is likely to proceed, and when the reaction temperature is at least the above upper limit value, problems such as decomposition of the ester compound (1) and the organic substance (A) are unlikely to occur.

In the production method of the present invention, components other than the vinyl alcohol polymer and the solvent may be added as long as the effects of the present invention are not impaired. Examples of the other components include polymerization inhibitors (phenothiazines and the like) and the like.

The modified vinyl alcohol-based polymer obtained by the production method of the present invention utilizes its characteristics as a composition alone or with other components added according to known methods such as molding, spinning, and emulsification, and is modified vinyl. It can be used in various applications in which alcohol-based polymers are used. For example, various applications of surfactants, paper coating agents, paper internalizers and paper modifiers such as pigment binders, adhesives such as wood, paper, aluminum foil and inorganic substances, non-woven binders, paints, warp glue. It can be used for agents, fiber processing agents, adhesives for hydrophobic fibers such as polyester, other various films, sheets, bottles, fibers, thickeners, flocculants, soil modifiers, hydrogels and the like.

The modified vinyl alcohol-based polymer obtained by the production method of the present invention contains a filler, a processing stabilizer such as a copper compound, a weather resistance stabilizer, and a colorant, depending on the intended use, as long as the effect of the present invention is not impaired. , UV absorber, light stabilizer, antioxidant, antistatic agent, flame retardant, plasticizer, other thermoplastic resin, lubricant, fragrance, defoaming agent, deodorant, bulking agent, release agent, mold release Additives such as agents, reinforcing agents, antifungal agents, preservatives, and crystallization rate retarders can be appropriately blended as needed.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. Unless otherwise specified, "%" and "parts" in Examples and Comparative Examples represent "% by mass" and "parts by mass", respectively.

[Calculation of the amount of hydroxyl groups in a vinyl alcohol polymer]
In the vinyl alcohol polymer as a raw material, the content of vinyl alcohol unit is A mol%, the content of acetate ester unit is B mol%, and the content of ethylene unit is C mol%. The amount of hydroxyl groups (mmol / g) of the system polymer was calculated. The content of the vinyl alcohol unit, the content of the acetic acid ester unit, and the content of the ethylene unit were measured by ¹ H-NMR.

Amount of hydroxyl group (mmol / g) = 1000 / [44 + {86 × (B / A)} + {28 × C / A}]

[Measurement of average particle size]
The vinyl alcohol-based polymer as a raw material was dispersed in methanol, and the volume average particle size (μm) was measured using a laser diffractometer "LA-950V2" manufactured by Horiba Seisakusho Co., Ltd.

[Measurement of specific surface area]
Using the specific surface area measuring device "MONOSORB" manufactured by Yuasa Ionics Co., Ltd., the specific surface area (m ² / g) of the raw material vinyl alcohol polymer was derived by the BET one-point method by nitrogen adsorption.

[Calculation of solubility parameter (δ)]
In the present specification, the Hildebrand solubility parameter δ _A of the organic substance (A) and the Hildebrand solubility parameter δ _B of the ester compound (1) are referred to as PolymerHandBook FourthEdition (John Wiley & Sons, Inc., 1999) II. It is described in 688, and the unit is (cal / cm) and the value of ^1/2 is referred to. Here, the Hildebrand solubility parameter (δ solve) of the solvent composed of the organic substance (A) and the ester compound (1) was calculated according to the following formula described in the above-mentioned _{PolymerHandBookFourthEdition} .
δ _solve = δ AVA + δ _B V _B ( _VA : volume fraction of organic matter ( _A ), V _B : volume _fraction of ester compound (1))
When the solvent contains a third component other than the organic substance (A) and the ester compound (1), the solubility parameter (δ _solve ) is calculated according to the following equation with the Hildebrand solubility parameter of the third component as δ _C. did.
δ _solve = δ _A V _A + δ _B V _B + δ _C VC _{(V c :} Volume fraction of the third component)
Here, as the Hildebrand solubility parameter (δ _C ) of the third component of the present specification, the value of the above-mentioned PolymerHandBookFourthEditionV is referred to. Even when the solvent contains a plurality of components such as a four-component system and a five-component system, the Hildebrand of the solvent is similarly calculated by calculating the sum of the Hildebrand solubility parameter of each component and the volume fraction. The solubility parameter (δ _solvent ) can be obtained.
The Fedors solubility parameter (δ _polym ) of the vinyl alcohol polymer was calculated by the Fedors method. The calculation method is described in Polymer Engineering Science, 14, p147 (1974).

[Evaluation of cleaning speed]
In Examples and Comparative Examples described later, 100 parts by mass of the undried resin filtered by a polyethylene terephthalate mesh (opening 56 μm) after the reaction was subjected to a chromatographic column (inner diameter 50 mm, opening diameter 40 to 50 μm) glass filter and cock. Attached). After filling 130 parts by mass of methanol here, the cock was opened and filtration was started. The time when 90% of the added methanol mass (that is, 117 parts by mass) is collected as a filtrate is defined as "filtration completion", and the washing speed is determined by the time required from the start of filtration to the completion of filtration. evaluated. The washing was performed twice, but the first filtration time was evaluated.

If filtration is completed in less than 90 seconds: A
When completed in 90 seconds or more and less than 180 seconds: B
When filtration is completed in 180 seconds or more and less than 300 seconds: C
If it takes more than 300 seconds to complete filtration: D

[Calculation of denaturation amount]
Using the nuclear magnetic resonance apparatus "LAMBDA 500" manufactured by Nippon Denshi Co., Ltd., ¹ H-NMR of the polymer obtained in Example or Comparative Example was measured in deuterated dimethyl sulfoxide at room temperature, and was derived from olefin protons. The amount of modification was calculated from the integrated value of the peak (5.0 to 7.5 ppm).

[Evaluation of water resistance]
2-Hydroxy-4'-(2-hydroxyethoxy) -2-methylpropiophenone as a photoinitiator was added to an aqueous solution (concentration: 5% by mass) containing the polymer obtained in the following Example or Comparative Example. A coating liquid was prepared by adding and dissolving the polymer in an amount of 1 part by mass with respect to 100 parts by mass. The coating liquid was poured onto a 15 cm × 15 cm mold prepared by bending the edges of a polyethylene terephthalate film, and the solvent was sufficiently volatilized at room temperature and atmospheric pressure to obtain a film having a thickness of about 100 μm. Here, UV light was irradiated with an intensity of 13200 mJ / cm ² to prepare an evaluation film. The obtained evaluation film was immersed in boiling water for 1 hour, removed from the water, vacuum dried at 40 ° C. for 12 hours, and then the mass (W3) was measured. From the obtained mass (W3) and the mass before immersion (W4), the elution rate under boiling conditions was calculated according to the following formula. Then, this elution rate was used as an index of water resistance (the lower the elution rate, the higher the water resistance).

Elution rate (% by mass) = 100 × ([W4]-[W3]) / [W4]

In the examples and comparative examples, any of the following vinyl alcohol-based polymers was used.
[PVOH-A]
A commercially available polyvinyl alcohol resin (PVA28-98 manufactured by Kuraray Co., Ltd.) was used.
[PVOH-B]
A commercially available polyvinyl alcohol resin (PVA5-74 manufactured by Kuraray Co., Ltd.) was used.
[PVOH-C1]
A commercially available polyvinyl alcohol resin (Elvanol (registered trademark) 71-30 manufactured by Kuraray America Incorporated) subjected to the following treatment was used.
That is, 100 parts by mass of polyvinyl alcohol resin (Elvanol (registered trademark) 71-30 manufactured by Kuraray America Incorporated) and 1900 parts by mass of dimethyl sulfoxide were added to a reactor equipped with a stirrer, and the mixture was stirred and dissolved at 100 ° C. After allowing the solution to cool to room temperature, it was added dropwise to 20000 parts by mass of methanol to precipitate a polyvinyl alcohol resin. The precipitated resin was washed twice with 1000 parts by mass of methanol and then dried overnight in a vacuum dryer at 40 ° C. The obtained resin was pulverized by an ultracentrifuge pulverizer and then classified using a sieve (106 μm to 300 μm).
[PVOH-C2]
A commercially available polyvinyl alcohol resin (Elvanol® 71-30 manufactured by Kuraray America Incorporated) was used.
[PVOH-C3]
A commercially available polyvinyl alcohol resin (Elvanol (registered trademark) 71-30 manufactured by Kuraray America Incorporated) classified using a sieve (53 μm) was used.
[PVOH-D]
A commercially available polyvinyl alcohol resin (LM-10HD manufactured by Kuraray Co., Ltd.) was used.
[PVOH-E]
A commercially available polyvinyl alcohol resin (L-508W manufactured by Kuraray Co., Ltd.) was used.
[EVOH-A]
A commercially available ethylene-vinyl alcohol copolymer resin (EVAL® F 101 manufactured by Kuraray Co., Ltd.) was pulverized with an ultracentrifuge pulverizer and then classified using a sieve (425 μm to 700 μm).

PVOH-A, PVOH-B, PVOH-C1, PVOH-C2, PVOH-C3, PVOH-D, PVOH-E and EVOH-A hydroxyl groups (mmol / g), average particle size (μm), specific surface area ( Table 1 shows the results of obtaining m ² / g) and the Fedors solubility parameter δ _polym by the above-mentioned method.

[Example 1]
A reactor equipped with a stirrer, a recirculation tube, and an addition port is charged with 450 parts by mass of dimethyl sulfoxide (DMSO) / 360 parts by mass of methyl methacrylate (MMA) / 90 parts by mass of toluene, and 100 parts by mass of PVOH-A while stirring at room temperature. , 1.8 parts by mass of sodium acetate and 2 parts by mass of phenothiazine were added and stirred at 80 ° C. to obtain a slurry solution. After 1 hour, the temperature was raised to 100 ° C. to start the reaction, and after reacting for 5 hours, the mixture was cooled to room temperature and filtered with a polyethylene terephthalate mesh (opening 56 μm). The undried resin that has been filtered off is washed twice according to the method described in the above-mentioned evaluation of the washing rate, and then dried in a vacuum dryer at 40 ° C. and 1.3 Pa overnight to obtain the desired modified vinyl. An alcohol-based polymer was obtained. The evaluation results are shown in Table 2.

[Example 2]
A reactor equipped with a stirrer, a recirculation tube, and an addition port is charged with 450 parts by mass of DMSO / 405 parts by mass of MMA / 45 parts by mass of methyl ethyl ketone, and 100 parts by mass of PVOH-A, 1.8 parts by mass of sodium acetate, and phenothiazine while stirring at room temperature. Two parts by mass were added and stirred at 80 ° C. to obtain a slurry solution. After 1 hour, the temperature was raised to 100 ° C. to start the reaction, and after reacting for 5 hours, the mixture was cooled to room temperature and filtered with a polyethylene terephthalate mesh (opening 56 μm). The undried resin that has been filtered off is washed twice according to the method described in the above-mentioned evaluation of the washing rate, and then dried in a vacuum dryer at 40 ° C. and 1.3 Pa overnight to obtain the desired modified vinyl. An alcohol-based polymer was obtained. The evaluation results are shown in Table 2.

[Example 3]
A reactor equipped with a stirrer, a recirculation tube, and an addition port is charged with 450 parts by mass of DMSO / 450 parts by mass of MMA, and 100 parts by mass of PVOH-A, 1.8 parts by mass of sodium acetate, and 2 parts by mass of phenothiazine are added while stirring at room temperature. The mixture was stirred at 80 ° C. to obtain a slurry solution. After 1 hour, the temperature was raised to 100 ° C. to start the reaction, and after reacting for 5 hours, the mixture was cooled to room temperature and separated by filtration with a polyethylene terephthalate mesh (opening 56 μm). The undried resin that has been filtered off is washed twice according to the method described in the above-mentioned evaluation of the washing rate, and then dried in a vacuum dryer at 40 ° C. and 1.3 Pa overnight to obtain the desired modified vinyl. An alcohol-based polymer was obtained. The evaluation results are shown in Table 2.

[Example 4]
Add 180 parts by mass of DMSO / 720 parts by mass of MMA to a reactor equipped with a stirrer, a recirculation tube, and an addition port, and add 100 parts by mass of PVOH-B, 1.1 parts by mass of sodium acetate, and 2 parts by mass of phenothiazine while stirring at room temperature. The mixture was stirred at 80 ° C. to obtain a slurry solution. After 1 hour, the temperature was raised to 100 ° C. to start the reaction, and after reacting for 5 hours, the mixture was cooled to room temperature and separated by filtration with a polyethylene terephthalate mesh (opening 56 μm). The undried resin that has been filtered off is washed twice according to the method described in the above-mentioned evaluation of the washing rate, and then dried in a vacuum dryer at 40 ° C. and 1.3 Pa overnight to obtain the desired modified vinyl. An alcohol-based polymer was obtained. The evaluation results are shown in Table 2.

[Example 5]
A reactor equipped with a stirrer, a recirculation tube, and an addition port was charged with 283 parts by mass of DMSO / 283 parts by mass of methyl 3,3-dimethyl-4-pentenate, and 100 parts by mass of PVOH-A and sodium methoxydo while stirring at room temperature. 8.6 parts by mass and 2 parts by mass of phenothiazine were added and stirred at 80 ° C. to obtain a slurry solution. After 1 hour, the temperature was raised to 100 ° C. to start the reaction, and after reacting for 5 hours, the mixture was cooled to room temperature and separated by filtration with a polyethylene terephthalate mesh (opening 56 μm). The undried resin that has been filtered off is washed twice according to the method described in the above-mentioned evaluation of the washing rate, and then dried in a vacuum dryer at 40 ° C. and 1.3 Pa overnight to obtain the desired modified vinyl. An alcohol-based polymer was obtained. The evaluation results are shown in Table 2.

[Example 6]
A reactor equipped with a stirrer, a recirculation tube, and an addition port was charged with 360 parts by mass of DMSO / 540 parts by mass of MMA, and while stirring at room temperature, 100 parts by mass of PVOH-C1, 5.9 parts by mass of zinc acetylacetone (II), and 2 parts by mass of phenothiazine. The parts were added and stirred at 80 ° C. to obtain a slurry solution. After 1 hour, the temperature was raised to 100 ° C. to start the reaction, and after reacting for 5 hours, the mixture was cooled to room temperature and filtered with a polyethylene terephthalate mesh (opening 56 μm). The undried resin that has been filtered off is washed twice according to the method described in the above-mentioned evaluation of the washing rate, and then dried in a vacuum dryer at 40 ° C. and 1.3 Pa overnight to obtain the desired modified vinyl. An alcohol-based polymer was obtained. The evaluation results are shown in Table 2.

[Example 7]
A reactor equipped with a stirrer, a recirculation tube, and an addition port is charged with 15 parts by mass of DMSO / 135 parts by mass of MMA, and 100 parts by mass of PVOH-D, 0.47 parts by mass of sodium acetate, and 0.5 parts by mass of phenothiazine while stirring at room temperature. Was added and stirred at 80 ° C. to obtain a slurry solution. After 1 hour, the temperature was raised to 100 ° C. to start the reaction, and after reacting for 5 hours, the mixture was cooled to room temperature and separated by filtration with a polyethylene terephthalate mesh (opening 56 μm). The undried resin that has been filtered off is washed twice according to the method described in the above-mentioned evaluation of the washing rate, and then dried in a vacuum dryer at 40 ° C. and 1.3 Pa overnight to obtain the desired modified vinyl. An alcohol-based polymer was obtained. The evaluation results are shown in Table 2.

[Example 8]
Add 45 parts by mass of DMSO / 855 parts by mass of MMA to a reactor equipped with a stirrer, a reflux tube, and an addition port, and add 100 parts by mass of PVOH-E, 1.1 parts by mass of sodium acetate, and 2 parts by mass of phenothiazine while stirring at room temperature. The mixture was stirred at 80 ° C. to obtain a slurry solution. After 1 hour, the temperature was raised to 100 ° C. to start the reaction, and after reacting for 5 hours, the mixture was cooled to room temperature and separated by filtration with a polyethylene terephthalate mesh (opening 56 μm). The undried resin that has been filtered off is washed twice according to the method described in the above-mentioned evaluation of the washing rate, and then dried in a vacuum dryer at 40 ° C. and 1.3 Pa overnight to obtain the desired modified vinyl. An alcohol-based polymer was obtained. The evaluation results are shown in Table 2.

[Example 9]
A reactor equipped with a stirrer, a recirculation tube, and an addition port is charged with 450 parts by mass of DMSO / 450 parts by mass of MMA, and 100 parts by mass of PVOH-C2, 1.9 parts by mass of sodium acetate, and 2 parts by mass of phenothiazine are added while stirring at room temperature. The mixture was stirred at 80 ° C. to obtain a slurry solution. After 1 hour, the temperature was raised to 100 ° C. to start the reaction, and after reacting for 5 hours, the mixture was cooled to room temperature and filtered with a polyethylene terephthalate mesh (opening 56 μm). The undried resin that has been filtered off is washed twice according to the method described in the above-mentioned evaluation of the washing rate, and then dried in a vacuum dryer at 40 ° C. and 1.3 Pa overnight to obtain the desired modified vinyl. An alcohol-based polymer was obtained. The evaluation results are shown in Table 2. When the obtained modified vinyl alcohol polymer was dissolved in water, insoluble components remained and the aqueous solution became slightly cloudy.

[Example 10]
Add 180 parts by mass of DMSO / 720 parts by mass of MMA to a reactor equipped with a stirrer, a reflux tube, and an addition port, and add 100 parts by mass of EVOH-A, 1.4 parts by mass of sodium acetate, and 2 parts by mass of phenothiazine while stirring at room temperature. The mixture was stirred at 80 ° C. to obtain a slurry solution. After 1 hour, the temperature was raised to 100 ° C. to start the reaction, and after reacting for 5 hours, the mixture was cooled to room temperature and filtered with a polyethylene terephthalate mesh (opening 56 μm). The undried resin that has been filtered off is washed twice according to the method described in the above-mentioned evaluation of the washing rate, and then dried in a vacuum dryer at 40 ° C. and 1.3 Pa overnight to obtain the desired modified vinyl. An alcohol-based polymer was obtained. The evaluation results are shown in Table 2.

[Example 11]
A reactor equipped with a stirrer, a recirculation tube, and an addition port is charged with 450 parts by mass of DMSO / 450 parts by mass of MMA, and 100 parts by mass of PVOH-C3, 1.9 parts by mass of sodium acetate, and 2 parts by mass of phenothiazine are added while stirring at room temperature. The mixture was stirred at 80 ° C. to obtain a slurry solution. After 1 hour, the temperature was raised to 100 ° C. to start the reaction, and after reacting for 5 hours, the mixture was cooled to room temperature and filtered with a polyethylene terephthalate mesh (opening 56 μm). The undried resin that has been filtered off is washed twice according to the method described in the above-mentioned evaluation of the washing rate, and then dried in a vacuum dryer at 40 ° C. and 1.3 Pa overnight to obtain the desired modified vinyl. An alcohol-based polymer was obtained. The evaluation results are shown in Table 2.

[Comparative Example 1]
A reactor equipped with a stirrer, a recirculation tube, and an addition port is charged with 180 parts by mass of water / 720 parts by mass of MMA, and 100 parts by mass of PVOH-C2, 1.9 parts by mass of sodium acetate, and 2 parts by mass of phenothiazine are added while stirring at room temperature. In addition, the mixture was stirred at 80 ° C. to obtain a slurry solution. After 1 hour, the temperature was raised to 100 ° C. to start the reaction, and after reacting for 5 hours, the mixture was cooled to room temperature and filtered with a polyethylene terephthalate mesh (opening 56 μm). The filtered undried resin was washed twice according to the method described in the above-mentioned evaluation of the washing rate, and then dried in a vacuum dryer at 40 ° C. and 1.3 Pa overnight to obtain a polymer. rice field. The evaluation results are shown in Table 2.

[Comparative Example 2]
A reactor equipped with a stirrer, a reflux tube, and an addition port is charged with 900 parts by mass of MMA, 100 parts by mass of PVOH-C2, 1.9 parts by mass of sodium acetate, and 2 parts by mass of phenothiazine are added while stirring at room temperature, and the mixture is stirred at 80 ° C. A slurry solution was obtained. After 1 hour, the temperature was raised to 100 ° C. to start the reaction, and after reacting for 5 hours, the mixture was cooled to room temperature and filtered with a polyethylene terephthalate mesh (opening 56 μm). The filtered undried resin was washed twice according to the method described in the above-mentioned evaluation of the washing rate, and then dried in a vacuum dryer at 40 ° C. and 1.3 Pa overnight to obtain a polymer. rice field. The evaluation results are shown in Table 2.

[Comparative Example 3]
A reactor equipped with a stirrer, a recirculation tube, and an addition port was charged with 720 parts by mass of DMSO / 3,3-dimethyl-4-pentenate by 180 parts by mass, and while stirring at room temperature, 100 parts by mass of PVOH-C2 and 0 parts of sodium methoxydone. When 2 parts by mass of .66 parts by mass of phenothiazine was added and stirred at 80 ° C., the resin swelled remarkably, resulting in poor stirring. After 1 hour, the temperature was raised to 100 ° C. to start the reaction, and after reacting for 3 hours, the mixture was cooled to room temperature. An attempt was made to filter the contents, but the swelling of the resin was so great that it was difficult to remove the reaction solution. Repeated 5 times. Then, it was dried overnight in a vacuum dryer at 40 ° C. and 1.3 Pa to obtain a modified vinyl alcohol-based polymer. The evaluation results are shown in Table 2.

[Comparative Example 4]
Add 45 parts by mass of DMSO / 855 parts by mass of MMA to a reactor equipped with a stirrer, a reflux tube, and an addition port, and add 100 parts by mass of PVOH-C2, 1.9 parts by mass of sodium acetate, and 2 parts by mass of phenothiazine while stirring at room temperature. The mixture was stirred at 80 ° C. to obtain a slurry solution. After 1 hour, the temperature was raised to 100 ° C. to start the reaction, and after reacting for 5 hours, the mixture was cooled to room temperature and filtered with a polyethylene terephthalate mesh (opening 56 μm). The filtered undried resin was washed twice according to the method described in the above-mentioned evaluation of the washing rate, and then dried in a vacuum dryer at 40 ° C. and 1.3 Pa overnight to obtain a polymer. rice field. The evaluation results are shown in Table 2.

From Examples 1 to 11, according to the production method of the present invention, the ester exchange reaction proceeds efficiently even in a solid-liquid reaction system using an ester compound that is industrially easily available and has low toxicity as a raw material. A modified vinyl alcoholic polymer having an unsaturated hydrocarbon group in the side chain can be produced by an industrial process in which isolation of the reaction product is easy. Further, the crosslinked product of the modified vinyl alcohol polymer obtained by the present invention is excellent in water resistance.

When the organic substance (A) is not used as in Comparative Example 1, the difference (δ _{polym-δ solve) between the Hildebrand solubility parameter δ solution of the solvent and the Fedors solubility parameter δ polym of the vinyl} alcohol polymer is defined in the present invention. Even within the range, the reaction does not proceed at all. Further, as shown in Comparative Example 2, when the organic substance (A) is not used and the difference in solubility parameter (δ _polym − δ _solve ) between the solvent and the vinyl alcohol polymer does not satisfy the provisions of the present invention, the reaction proceeds. do not do. Similarly, even if the organic substance (A) is present in the system as in Comparative Examples 3 and 4, the difference in solubility parameter between the solvent and the vinyl alcohol polymer (δ _polym − δ _solve ) is defined in the present invention. If the range is not satisfied, problems such as poor filtration and the reaction itself not proceeding occur.

Claims (6)

A modified vinyl alcohol-based polymer is reacted by dispersing the vinyl alcohol-based polymer in a solvent containing an organic substance (A) having a Hidebrand solubility parameter δ _A of 10 to 15 and an ester compound represented by the following formula (1). A modification method for producing a coalescence, wherein the difference (δ _polym- δ _solution ) between the Hildebrand solubility parameter δ- _solv of the solvent and the Fedors solubility parameter δ- _polym of the vinyl alcohol-based polymer is 2.8 to 6.0. A method for producing a vinyl alcohol-based polymer.

[In the formula (1), R ¹ , R ² and R ³ independently have a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, and an alicyclic which may have a substituent. Formula Represents an aromatic hydrocarbon group or an aromatic hydrocarbon group which may have a substituent. X may have a divalent aliphatic hydrocarbon group which may have a substituent, a divalent alicyclic hydrocarbon group which may have a substituent, or a substituent. Represents a divalent aromatic hydrocarbon group. n represents an integer from 0 to 10. ^R4 is a saturated aliphatic hydrocarbon group which may have a substituent, an alicyclic hydrocarbon group which may have a substituent, or an aromatic hydrocarbon which may have a substituent. Represents a group. ] The production method according to claim 1, wherein the amount of hydroxyl groups contained in the vinyl alcohol polymer is 10 to 23 mmol / g. The production method according to claim 1 or 2, wherein the vinyl alcohol-based polymer is polyvinyl alcohol. The production method according to any one of claims 1 to 3, wherein the content of the organic substance (A) per 100 parts by mass of the solvent is 10 to 60 parts by mass. The production method according to any one of claims 1 to 4, wherein the vinyl alcohol-based polymer is particles having an average particle diameter of 50 to 1000 μm. The production method according to any one of claims 1 to 5, wherein the vinyl alcohol-based polymer is particles having a specific surface area of 0.1 to 1.0 m ² / g.