JP2001019770A - Polyvinyl alcohol-based graft polymer, polyvinyl alcohol-based block polymer and their production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an industrially highly useful polyvinyl alcohol-based polymer having a hydrophobic component. SOLUTION: This polyvinyl alcohol-based graft copolymer has polyvinyl alcohol-based polymers as stem components and polystyrene-based polymers as branch components and the stem components and the branch components are bonded through ether bonds. This polyvinyl alcohol-based block polymer is a diblock polymer or a triblock polymer consisting of a component comprising a polyvinyl alcohol-based polymer and a component comprising a polystyrene- based polymer and both components are bonded through ether bonds.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a PVA block polymer or PVA graft polymer comprising a polyvinyl alcohol (hereinafter referred to as PVA) polymer component and a polystyrene (hereinafter referred to as PSt) polymer component. .

[0002]

2. Description of the Related Art Conventionally, as a means for imparting useful properties to a polymer, a general-purpose polymer is modified, a functional group or a reactive group is added, or a functional group or a reactive group is added from the beginning. Various methods have been proposed, such as polymerization or copolymerization of a monomer having a group, or bonding of a heterogeneous polymer as a second component to a polymer chain in a graft or block manner. Of these, the most common method is to bond a different kind of polymer, which is the second component, to the polymer chain in a graft or block manner, and many proposals have been made on so-called block polymer or graft polymer production techniques. Among these, in particular, the PVA-based polymer component and P
The block polymer or graft polymer with the St-based polymer component is an amphiphilic polymer obtained by adding a hydrophobic component to a PVA-based polymer which is a typical water-soluble resin, and has extremely high industrial value.

A graft comprising a PVA polymer as a component,
Alternatively, as a method for synthesizing a block polymer, a method of synthesizing a block copolymer by radically polymerizing various monomers using polyvinyl acetate having a thiol group at a terminal as a chain transfer agent and then saponifying (Japanese Patent Application Laid-Open No. H10-163873) No. 59-189111). However, the PVA-based component obtained by applying this method and the PSt
A block polymer composed of a system polymer component is thermally unstable because both components are bonded via S (sulfur group), and has a problem that it is easily colored when dried or heated. Also, a method of synthesizing a macromonomer of a PVA-based polymer and copolymerizing it using the macromonomer (JP-A-4-296)
No. 301, JP-A-4-304202) and the like, but there is no report on a graft polymer having a PVA-based polymer as a trunk component and a PSt-based polymer component as a branch. Furthermore, the PV obtained by applying these methods
Even in a block polymer composed of an A-based component and a PSt-based polymer component, both components are thermally unstable because they are bonded via S (sulfur group), and are easily colored during drying or heating. There is a problem to say.

In recent years, as a method for synthesizing a block copolymer containing a PVA-based polymer as one component, a so-called living polymerization method (JP-A-62-257910, JP-A-62-257) has been proposed.
911, JP-A-1-108202, JP-A-1-10
No. 8203), a block copolymer comprising a PVA component and a polyalkenyl ether component is obtained by block copolymerization of benzyl vinyl ether and another alkenyl ether, followed by debenzylation. Methods for synthesizing polymers are known. However, the PVA-based polymer component and PSt according to this method
No block polymer or graft polymer with a system polymer component has been reported. Further, a method is known in which a polyalkenyl ether having a thiol group at one end is synthesized by living cationic polymerization, and then vinyl esters are polymerized in the presence of the polymer to further saponify the obtained block polymer ( JP-A-6-136
No. 036), but the polymerizability of vinyl ester is very low in the presence of polystyrene,
It is very difficult to synthesize a block polymer of the A-based polymer component and the PSt-based polymer component. As described above, although a graft polymer, a diblock polymer, or a triblock polymer composed of a PVA-based polymer component and a PSt-based polymer component is industrially very useful, it is not known, or Even if reported, there was a problem that it was thermally unstable and was not suitable for industrial use.

[0005]

SUMMARY OF THE INVENTION It is a main object of the present invention to provide an industrially useful PVA having a hydrophobic component.
The object is to provide a system polymer.

[0006]

As a result of intensive studies to solve the above-mentioned problems, it was found that PVA-based polymer was
A PVA-based graft polymer having a St-based polymer as a branch component and a trunk component and a branch component linked via an ether bond, or a component comprising a PVA-based polymer; A PVA-based diblock polymer or a PVA-based triblock polymer, wherein the PVA-based polymer component and the PSt-based polymer component are bonded via an ether bond. Found that the above object was achieved, and completed the present invention.

Hereinafter, the contents of the present invention will be described in more detail. The PVA-based polymer constituting one component of the graft polymer or block polymer of the present invention usually comprises a vinyl alcohol unit and a vinyl ester unit. As the vinyl ester unit, a bulky vinyl ester having a side chain such as vinyl acetate, vinyl pivalate and vinyl formate, or a vinyl ester having a high polarity is usually selected.

The degree of saponification of the PVA polymer component is usually 7
0 mol% or more is preferable, 90 mol% or more is more preferable, and 95 mol% or more is further preferable. Here, the degree of saponification indicates the ratio of a vinyl alcohol unit after saponification to a unit that can be converted into a vinyl alcohol unit by saponification of a vinyl ester unit, and the residue is a vinyl ester unit.

The PVA-based polymer component may have various copolymerized monomer units for the purpose of modifying the PVA-based polymer component as long as the purpose of the present invention is not impaired. Examples of such a unit include olefins such as ethylene, propylene, 1-butene, and isobutene; acrylic acid and its salts; methyl acrylate; ethyl acrylate; n-propyl acrylate; i-propyl acrylate; N-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate,
Acrylic esters such as dodecyl acrylate and octadecyl acrylate, methacrylic acid and its salts, methyl methacrylate, ethyl methacrylate, n-methacrylic acid
Propyl, i-propyl methacrylate, n-methacrylate
-Butyl, i-butyl methacrylate, t-methacrylate
Methacrylic esters such as butyl, 2-ethylhexyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, acrylamide, N-methylacrylamide, N-ethylacrylamide, N, N-dimethylacrylamide, diacetoneacrylamide, acrylamidepropanesulfonic acid And its salts, acrylamidopropyldimethylamine and its salts and quaternary salts, acrylamide derivatives such as N-methylolacrylamide and its derivatives, methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N, N-dimethylmethacrylamide , Diacetone methacrylamide,
Methacrylamidopropanesulfonic acid and its salts, methacrylamidopropyldimethylamine and its salts and quaternary salts, methacrylamide derivatives such as N-methylol methacrylamide and its derivatives, methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl Vinyl ethers such as vinyl ether, i-butyl vinyl ether, t-butyl vinyl ether, benzyl vinyl ether, dodecyl vinyl ether, and stearyl vinyl ether; nitriles such as acrylonitrile and methacrylonitrile; vinyl chloride, vinylidene chloride, vinyl fluoride and vinylidene fluoride; Vinyl halides, allyl compounds such as allyl acetate and allyl chloride, maleic acid and its salts and esters, itaconic acid and its salts and ester , Vinylsilyl compounds such as vinyltrimethoxysilane, is isopropenyl acetate and the like. The amount of these copolymerized monomers is not particularly limited as long as the object of the present invention is not impaired, but is usually 0 to 15
Mol%, particularly preferably 0 to 10 mol%.

The degree of polymerization of the PVA-based polymer component is appropriately selected depending on the use of the finally obtained graft polymer or block polymer, but is 500 or more, preferably 1000 or more, more preferably 2000 or more. From the viewpoints of viscosity, film forming properties, and processing characteristics such as stretching. Here, the degree of polymerization is JISK
It is a viscosity average polymerization degree determined based on -6726.

The stereoregularity of the PVA-based polymer component in the present invention is not particularly limited, but is preferably an atactic structure or a syndiotactic structure close to an atactic structure, and more preferably an atactic structure.

The monomer which is a constituent unit of the PSt polymer as the other component in the graft polymer or the block polymer in the present invention is styrene represented by the following general formula (1) or (2). Alternatively, a styrene derivative is used.

[0013]

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[0014]

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In the general formulas (1) and (2),
R1 represents a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, and may contain a hetero atom such as oxygen or nitrogen. Specifically, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s
ec-butyl group, tert-butyl group, pentyl group, t
ert-amyl group, hexyl group, cyclohexyl group, heptyl group, octyl group, ethylhexyl group, nonyl group,
Alkyl group such as decyl group, 3-oxabutyl group, 3-
Oxapentyl group, 3-oxahexyl group, 3-oxaheptyl group, 3-oxaoctyl group, 3-oxanonyl group, 3-oxadecyl group, 3-oxaundecyl group, 4
-Oxapentyl group, 4-oxahexyl group, 4-oxaheptyl group, 4-oxaoctyl group, 4-oxanonyl group, 4-oxadecyl group, 4-oxaundecyl group,
5-oxahexyl group, 5-oxaheptyl group, 5-oxaoctyl group, 5-oxanonyl group, 5-oxadecyl group, 5-oxaundecyl group, 6-oxaheptyl group, 6-oxaoctyl group, 6-oxanonyl group, 6-
Oxadecyl group, 6-oxaundecyl group, 7-oxaoctyl group, 7-oxanonyl group, 7-oxadecyl group, 7-oxaundecyl group, 8-oxanonyl group, 8
-Oxadecyl group, 8-oxaundecyl group, 9-oxadecyl group, 9-oxaundecyl group, 10-oxaundecyl group, 3,6-dioxaheptyl group, 3,6-dioxaoctyl group, 3,6-dioxanonyl group, 3 , 6
-Dioxadecyl group, 3,6-dioxaundecyl group,
3,6-dioxadodecyl group, 3,6,9-trioxadecyl group, 3,6,9-trioxaundecyl group, 3,
6,9-trioxadodecyl group, 3,6,9-trioxatridecyl group, 3,6,9,12-tetraoxatridecyl group, 3,6,9,12-tetraoxatetradecyl group and the like And an oxygen-containing hydrocarbon group. In the general formulas (1) and (2), R2 represents hydrogen or a linear or branched alkyl group having 1 to 3 carbon atoms;
It may contain a hetero atom such as oxygen or nitrogen. In addition, the bonding position of R1 and -OR1 to the benzene ring in the general formulas (1) and (2) is the o-position or the p-position.

Next, a method for producing the PVA-based graft polymer, the PVA cage block polymer and the PVA-based triblock polymer of the present invention will be described. As a method for producing the graft polymer, diblock polymer and triblock polymer of the present invention, a PVA-based polymer
PVA-based graft polymer having an St-based polymer component in a branch and both bonded via an ether bond, or PVA wherein a PVA-based polymer component and a PSt-based polymer component are bonded via an ether bond Diblock, PVA
The method is not particularly limited as long as the method can efficiently produce a systemic triblock polymer. For example, synthesizing a so-called macromonomer having a polymerizable functional group such as an alkenyl ether group introduced at one end of a PSt-based polymer, copolymerizing this with a vinyl ester, and then saponifying the vinyl ester unit. Can be used to synthesize the PVA-based graft polymer required.

When a PSt-based polymer component is synthesized by a cationic polymerization method of a styrene compound represented by the general formula (1) or (2), one end, both ends, or a side thereof is used as a terminator for the polymerization. The PVA-based polymer having a hydroxyl group in the chain may be allowed to coexist during the polymerization of the PSt-based polymer or may be added after the polymerization reaction.
A-based graft polymer, PVA-based diblock polymer,
A PVA-based triblock polymer can be obtained efficiently.

The method of introducing one or more hydroxyl groups at one end, both ends, or side chains of the PVA polymer is not particularly limited, but for example, the following method is used.

First, as a method of introducing a hydroxyl group into the terminal of the PVA-based polymer, it is preferable to use so-called living polymerization since the hydroxyl group can be introduced into the terminal of the polymer at a required introduction rate. For example, vinyl ethers such as t-butyl vinyl ether, benzyl vinyl ether, and trimethylsilyl vinyl ether are subjected to living cationic polymerization with a polymerization initiator having a hydroxyl group protected by a trimethylsilyl group, a t-butyl group, a benzyl group, etc., and these monomers are used alone. After obtaining a polymer or a random copolymer or a block copolymer composed of two or more of these monomers, the hydroxyl group protected by the initiator is deprotected, and further, or simultaneously, the side chain of the vinyl ether is converted to a hydroxyl group. By converting into a polymer, a hydroxyl group can be accurately introduced into one end of each polymer. Alternatively, after obtaining a homopolymer of these monomers, or a random copolymer or a block copolymer of two or more of these monomers by living cationic polymerization, a trimethylsilyl group, a t-butyl group, a benzyl group By adding a compound having a hydroxyl group protected by, for example, and a free hydroxyl group at the same time, the hydroxyl group can be introduced into one end of each polymer with high accuracy. Furthermore, by performing both methods simultaneously, hydroxyl groups can be introduced into both terminals of the polymer with high accuracy.

If the living radical polymerization, which has been actively studied in recent years, is used as the living polymerization, it is not necessary to protect the hydroxyl group as in the case of the living cationic polymerization in order to proceed with the polymerization. Hydroxyl groups can be introduced at both ends. For example, a vinyl ester is subjected to living radical polymerization by a polymerization initiator having a hydroxyl group introduced thereto to obtain a homopolymer of these monomers, or a random copolymer or a block copolymer of two or more of these monomers. This makes it possible to introduce a hydroxyl group into one end of each polymer with high accuracy. Alternatively, after obtaining a homopolymer of these monomers, or a random copolymer or a block copolymer composed of two or more of these monomers by living radical polymerization, it contains a hydroxyl group such as hydroxylethyl methacrylate. A hydroxyl group can be introduced into one end of each polymer with high accuracy even by adding a radical polymerizable monomer to the polymer in an amount equivalent to the growth end of the polymer. further,
By performing both methods simultaneously, hydroxyl groups can be introduced into both ends of the polymer with high accuracy. Also, hydroxyl groups can be introduced into both terminals of these polymers by performing radical polymerization of these monomers using hydrogen peroxide as a chain transfer agent.

The method for introducing one or more hydroxyl groups into the PVA-based polymer is not particularly limited, but for example, the following method is used.

That is, when a homopolymer of vinyl esters or a random copolymer, block polymer or graft polymer having at least one vinyl ester monomer as a constitutional unit is synthesized, a polymerizable monomer having a hydroxyl group is used. By copolymerizing an appropriate amount, a hydroxyl group can be easily introduced into the polymer.
The polymerizable monomer containing a hydroxyl group is not particularly limited as long as it has sufficient polymerizability to be introduced into the polymer,
For example, allyl alcohol, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-methylpropan-1-ol and the like are used. Further, when the presence of a hydroxyl group-containing monomer inhibits the polymerization as in living cationic polymerization, a monomer in which the hydroxyl group in these monomers is protected with a trimethylsilyl group, a t-butyl group, a benzyl group, or the like, or trimethylsilyl vinyl ether, t After copolymerization of -butyl vinyl ether, benzyl vinyl ether and the like, and deprotection, a PVA-based polymer containing a hydroxyl group in the polymer can be easily obtained. The content of the hydroxyl group in the polymer is appropriately selected depending on the use of the finally obtained block polymer or the graft polymer, but is usually 0.0001 to 50 mol% based on the PVA-based polymer. 0.001 to 30
A mole% range is preferred.

As a method for introducing one or more hydroxyl groups into the terminal of the PVA polymer or into the polymer, saponified vinyl ester homopolymers or copolymers are particularly preferred. Saponified ethylene / vinyl ester copolymers are also preferably used.

In the present invention, a saponified vinyl ester homopolymer or copolymer used as a PVA-based polymer component is usually a saponification reaction of a vinyl acetate homopolymer or copolymer (a side reaction in the presence of an alkali). Chain decomposition reaction). It can also be obtained by saponification of a homopolymer or copolymer of a vinyl ester having a bulky side chain or a vinyl ester having a high polarity such as vinyl pivalate or vinyl formate.

Here, the comonomer unit in the case of the copolymer is divided into a unit which forms a vinyl alcohol unit by saponification or decomposition and a unit other than the unit.

Examples of the latter comonomer unit include olefins such as ethylene, propylene, 1-butene and isobutene, acrylic acid and salts thereof, methyl acrylate, ethyl acrylate, n-propyl acrylate, and the like.
Acrylates 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 acid Methacrylic esters such as octadecyl, acrylamide,
N-methylacrylamide, N-ethylacrylamide, N, N-dimethylacrylamide, diacetoneacrylamide, acrylamidepropanesulfonic acid and its salts, acrylamidopropyldimethylamine and its salts and quaternary salts, N-methylolacrylamide and its derivatives, etc. Acrylamide derivative, methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N, N-dimethylmethacrylamide, diacetone methacrylamide, methacrylamidopropanesulfonic acid and salts thereof, methacrylamidopropyldimethylamine and salts thereof And quaternary salts, methacrylamide derivatives such as N-methylol methacrylamide and derivatives thereof, methyl vinyl ether, ethyl vinyl ether, n
Vinyl ethers such as -propyl vinyl ether, i-propyl vinyl ether, i-butyl vinyl ether, t-butyl vinyl ether, benzyl vinyl ether, dodecyl vinyl ether, and stearyl vinyl ether;
Nitriles such as acrylonitrile and methacrylonitrile; vinyl chlorides such as vinyl chloride, vinylidene chloride, vinyl fluoride and vinylidene fluoride; allyl compounds such as allyl acetate and allyl chloride; maleic acid and its salts and esters; itaconic acid And salts and esters thereof, vinylsilyl compounds such as vinyltrimethoxysilane, and isopropenyl acetate.

The amount of these copolymerized monomers is not particularly limited as long as the object of the present invention is not impaired.
Usually, it is 0 to 15 mol%, particularly preferably 0 to 1 mol%.
0 mol%.

By saponifying an appropriate amount of a vinyl ester unit in a vinyl ester homopolymer or copolymer, a hydroxyl group can be easily introduced into the polymer. At this time, the degree of saponification is determined by the PS which is graft-reacted into the PVA polymer.
The amount is appropriately selected depending on the introduction amount of the t-based polymer, the intended use of the graft polymer finally obtained, and the like, but is usually 0.001 to 99.9 mol%, and preferably 0.1%.
９９99.9 mol%. Here, the degree of saponification represents the ratio of a vinyl alcohol unit after saponification to a unit that can be converted into a vinyl alcohol unit by saponification in a homopolymer or copolymer of vinyl ester, and the residue is a vinyl ester unit. It is.

The number-average molecular weight of the saponified vinyl ester homopolymer or copolymer used in the present invention is appropriately selected depending on the use of the finally obtained graft polymer. 10
00000 or more, preferably in the range of 500 to 500,000.

Next, the saponified ethylene / vinyl ester copolymer which is suitably used as one of the PVA-based polymers in the present invention will be described. The saponified ethylene / vinyl ester copolymer is usually obtained by a saponification reaction of a copolymer of ethylene and vinyl acetate. Also,
It can also be obtained by saponification of a copolymer of ethylene with a vinyl ester having a bulky side chain such as vinyl pivalate or vinyl formate or a vinyl ester having a high polarity.

The ethylene content in the ethylene / vinyl ester copolymer used in the present invention is appropriately selected depending on the use in which the finally obtained graft polymer is used, but is usually 15 to 95 mol%. Preferably 20 to
75 mol%.

The saponified ethylene / vinyl ester copolymer used in the present invention may be copolymerized with other comonomers as long as the purpose of the present invention is not impaired. The comonomer units used include:
For example, olefins such as propylene, 1-butene, isobutene, acrylic acid and its salts, methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-acrylate Butyl, t-butyl acrylate, 2-acrylate
Ethylhexyl, dodecyl acrylate, acrylates such as octadecyl acrylate, methacrylic acid and its salts, methyl methacrylate, ethyl methacrylate,
Methacrylates such as n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, Acrylamide,
N-methylacrylamide, N-ethylacrylamide, N, N-dimethylacrylamide, diacetoneacrylamide, acrylamidepropanesulfonic acid and its salts, acrylamidopropyldimethylamine and its salts and quaternary salts, N-methylolacrylamide and its derivatives, etc. Acrylamide derivative, methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N, N-dimethylmethacrylamide, diacetone methacrylamide, methacrylamidopropanesulfonic acid and salts thereof, methacrylamidopropyldimethylamine and salts thereof And quaternary salts, methacrylamide derivatives such as N-methylol methacrylamide and derivatives thereof, methyl vinyl ether, ethyl vinyl ether, n
Vinyl ethers such as -propyl vinyl ether, i-propyl vinyl ether, i-butyl vinyl ether, t-butyl vinyl ether, benzyl vinyl ether, dodecyl vinyl ether, and stearyl vinyl ether;
Nitriles such as acrylonitrile and methacrylonitrile; vinyl chlorides such as vinyl chloride, vinylidene chloride, vinyl fluoride and vinylidene fluoride; allyl compounds such as allyl acetate and allyl chloride; maleic acid and its salts and esters; itaconic acid And salts and esters thereof, vinylsilyl compounds such as vinyltrimethoxysilane, and isopropenyl acetate.

The amount of the copolymerized monomer is not particularly limited as long as it does not impair the present invention, but is usually 0 to 15 mol%, particularly preferably 0 to 10 mol%.

By saponifying an appropriate amount of vinyl ester units in the ethylene / vinyl ester copolymer, a hydroxyl group can be easily introduced into the polymer. The degree of saponification at this time is appropriately selected depending on the amount of the PSt-based polymer to be grafted into the PVA-based polymer, the use of the finally obtained graft polymer, and the like.
0.1 to 99.9 mol%, preferably 0.1 to 9
It is in the range of 9.9 mol%. Here, the degree of saponification represents the ratio of a vinyl alcohol unit after saponification to a unit that can be converted into a vinyl alcohol unit by saponification in a homopolymer or copolymer of vinyl ester, and the residue is a vinyl ester unit. It is.

The molecular weight of the saponified ethylene / vinyl ester copolymer used in the present invention is appropriately selected depending on the use in which the finally obtained graft polymer is used, but is usually 100 to 1,000,000 or more in number average molecular weight. , Preferably in the range of 500 to 500,000. The degree of polymerization of the saponified ethylene / vinyl ester copolymer is appropriately selected depending on the use of the polymer finally selected, but is 300 or more, preferably 500 or more, more preferably 1000 or more. It is 30,000 or less from the viewpoint of processing characteristics such as film forming property and stretchability. Here, the degree of polymerization is a viscosity average degree of polymerization measured based on JIS K-6726.

Next, a method for obtaining a PSt-based polymer component by a cationic polymerization method will be described. The cationic polymerization initiator used when obtaining a PSt-based polymer by using cationic polymerization is a method in which a carbonium ion is generated from a compound as a monomer, and is added to a second or third monomer for polymerization. The compound is not particularly limited as long as it is a compound that promotes the reaction. Specifically, protonic acids (sulfuric acid, phosphoric acid, hydrochloric acid, bromic acid, nitric acid, hydrogen fluoride, hydrogen iodide, acetic acid and chlorinated products thereof, trifluoroacetic acid, p-toluenesulfonic acid,
Etc.), metal oxides and other solid acids (chromium oxide,
Phosphorus oxide, titanium oxide, aluminum oxide, cobalt oxide, manganese oxide, molybdenum oxide, silica-alumina, vanadium oxide, aluminum sulfate, iron sulfate, chromium sulfate, etc.),
Halogen (iodine, bromine, chlorine, iodine bromide, iodine chloride, bromine chloride), metal halides (beryllium, magnesium, zinc, cadmium, mercury, boron, aluminum,
Gallium, titanium, zirconium, tin, phosphorus, antimony, niobium, bismuth, thallium, uranium, rhenium,
Bromides, chlorides or fluorides of iron, etc., organometallic compounds (aluminum or zinc alkyl compounds, magnesium alkyl compounds called Grignard reagents, etc.), stable carbonium ions (triphenylmethylcarbonium ion, tropium Salts such as lium ions)
And the like. Among these initiators, metal-containing initiators include compounds that generate protons as necessary (water, hydroxy compounds such as alcohols, protonic acids, etc.) and compounds that generate carbonium ions (halogens). Alkyl fluorides) are added as co-catalysts.

Here, as the cationic polymerization method for synthesizing a PSt-based polymer component, it is easy to control the molecular weight, composition, and structure, and it is easy to obtain a uniform polymer having a narrow molecular weight distribution and composition distribution. Living cation polymerization is preferred because of high grafting efficiency to the polymer.

The living cationic polymerization initiator is not particularly limited as long as the cationic polymerization of styrene or a styrene derivative proceeds in a living manner. For example, HI reported in JP-A-3-56503
Initiator in which a protic acid such as ZnCl _{2 and} a Lewis acid such as ZnCl ₂ are combined.
No. 287022 and JP-A-6-157627, an initiator combining a protonic acid / Lewis acid / quaternary ammonium salt, and an organic halogen compound and a Lewis acid disclosed in JP-A-5-310832. And an initiator in combination with a halogen compound having the following.

The cationic polymerization reaction can be carried out in the absence of a solvent, but can also be carried out in the presence of a suitable organic solvent. As the organic solvent, for example, benzene,
Aromatic hydrocarbon solvents such as toluene and xylene; aliphatics such as propane, n-butane, isobutane, n-pentane, n-hexane, n-heptane, n-octane, isooctane, decane, hexadecane, isopentane and n-hexane Hydrocarbon solvents; halogenated hydrocarbon solvents such as ethylene chloride, methylene chloride and carbon tetrachloride; and ether solvents such as tetrahydrofuran (THF), dioxane, diethyl ether, dibutyl ether and ethylene glycol diethyl ether. Among these organic solvents, toluene, methylene chloride and THF are preferably used. These organic solvents are used alone or in combination of two or more as necessary.

The polymerization temperature varies depending on the type of polymerization initiator, monomer, solvent and the like to be used, but is usually from -80 ° C.
It is preferably in the range of 150C, more preferably in the range of -78C to 80C. The polymerization time depends on the polymerization initiator used,
It depends on the monomer, solvent, reaction temperature, etc.
The range is from minutes to 100 hours. The polymerization reaction can be carried out by either a batch method or a continuous method.

The molecular weight of the PSt-based polymer obtained by cationic polymerization depends on the final obtained block polymer,
The number average molecular weight is usually about 500 to 1,000,000, preferably in the range of 1,000 to 500,000, although it is appropriately selected depending on the use of the graft polymer. The ratio (Mw / Mn) between the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the obtained polymer obtained from a standard polystyrene calibration curve by gel permeation chromatography (GPC) is usually 1.0. ~ 10.0
And more preferably in the range of 1.0 to 5.0.

When a living cationic polymerization method is used as the cationic polymerization method, the molecular weight of the resulting PSt-based polymer is almost uniquely determined by the molar ratio between the monomer and the polymerization initiator. By varying the proportion of the amount used, the molecular weight of the polymer can be controlled over a wide range. The molecular weight of the PSt-based polymer obtained by living cationic polymerization is appropriately selected depending on the use of the finally obtained block polymer or graft polymer, but is usually 500 to 100 in number average molecular weight.
About 0000, preferably 1000 to 50,000
It is in the range of 0. The ratio (Mw / Mn) of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) of the polymer obtained by gel permeation chromatography (GPC) from a standard polystyrene calibration curve is usually 1.
It is in the range of 0 to 1.5, more preferably in the range of 1.0 to 1.45.

When a PSt-based polymer is synthesized by a cationic polymerization method, a hydroxyl group-containing PVA-based polymer component may be used as a terminator in the coexistence or added after the polymerization. There is no particular limitation as long as it is a condition for efficiently blocking or grafting the coalescence. For example, when the cationic polymerization is carried out using a cationic polymerizable monomer which is a constitutional unit of the PSt-based polymer or a suitable organic solvent in advance, the PVA-based polymer is dissolved in the solvent, and then the cationic polymerization reaction is performed. When the PSt polymer is synthesized, P
A method of proceeding a blocking or grafting reaction to a VA polymer is exemplified. Alternatively, a method of adding a PVA-based polymer dissolved in a suitable organic solvent during bulk polymerization or during a cationic polymerization reaction in a suitable organic solvent, or after completion of the polymerization reaction, may be mentioned. PVA
As a method for adding a polymer, a molded article of a PVA polymer having an appropriate shape such as a film, a sheet, a fiber, a tube, or the like is made to coexist with a cationic polymerization reaction system for synthesizing a PSt polymer, or By adding after finishing, it is also possible to selectively block or graft the PSt-based polymer on the surface of these molded articles.

Blocking or grafting of the PSt-based polymer to the PVA-based polymer is performed efficiently, and
In order to avoid the incorporation of unreacted PSt-based polymer or PVA-based polymer, the polymerization of PSt-based polymer is carried out in a suitable organic solvent by living cationic polymerization to obtain a desired molecular weight and structure, and then stopped. It is preferable to add a PVA-based polymer dissolved in an appropriate organic solvent as an agent.

When the PVA-based polymer is dissolved in a suitable organic solvent and added, the organic solvent used is not particularly limited as long as it is a solvent that efficiently dissolves the PVA-based polymer. Aromatic hydrocarbon solvents such as xylene; propane, n-butane, isobutane, n-pentane, n-hexane, n-heptane, n-octane, isooctane, decane, hexadecane, isopentane, n-
Aliphatic hydrocarbon solvents such as hexane; halogenated hydrocarbon solvents such as ethylene chloride, methylene chloride, and carbon tetrachloride; ether solvents such as tetrahydrofuran (THF), dioxane, diethyl ether, dibutyl ether, and ethylene glycol diethyl ether; or Dimethyl sulfoxide, dimethylformamide, N-methylpyrrolidone and the like can be mentioned. These organic solvents are used alone or in combination of two or more as necessary.
In order to efficiently promote the blocking or grafting of the PSt-based polymer and the PVA-based polymer, it is preferable to select a combination of solvents that does not make the reaction system non-uniform when adding the PVA-based polymer, It is more preferable to use the same solvent as the organic solvent for performing the cationic polymerization for synthesizing the PSt-based polymer.

The temperature at which the PVA polymer is added is usually 0 ° C.
The range is preferably from 150 to 150 ° C, more preferably from 20 to 80 ° C. The reaction time of the PSt-based polymer and the PVA-based polymer depends on the type and molecular weight of the PVA-based polymer used,
Although it varies depending on the type and molecular weight of the PSt-based polymer, the solvent used, the reaction temperature and the like, it is usually in the range of 10 minutes to 100 hours.

When a vinyl ester homopolymer or copolymer having a high degree of saponification or a saponified ethylene / vinyl ester copolymer is used as the PVA-based polymer,
These polymers are generally difficult to dissolve in an organic solvent or the viscosity of the solution after dissolution is so high that it may be difficult to efficiently promote a blocking or grafting reaction with a PSt-based polymer. In such a case, a PVA-based polymer component obtained by copolymerizing a saponified product having a sufficient solubility in an organic solvent and a sufficient amount of a hydroxyl group introduced, or a desired amount of a monomer containing a hydroxyl group is copolymerized with a PVA-based polymer component. Used as
After performing the blocking or grafting reaction with the PSt-based polymer, it is desirable to perform the saponification reaction to a desired degree of saponification. At this time, the degree of saponification of the PVA-based polymer at the time of reacting with the PSt-based polymer is sufficient to easily dissolve in an appropriate organic solvent used for the reaction and to allow the blocking or grafting reaction to proceed efficiently. There is no particular problem as long as a low solution viscosity can be obtained.
３０30 mol%, and the range of 0.001 to 25 mol% is more preferable. The degree of saponification of the PVA-based polymer in the finally obtained diblock polymer, triblock polymer or graft polymer is 70 mol% or more, preferably 80 mol% or more, more preferably 90 mol% or more. In the case of an ethylene / vinyl alcohol copolymer, the degree of saponification is at least 70 mol%, preferably at least 80 mol%.
Mol% or more, more preferably 90 mol% or more.

The number average molecular weight of the graft polymer or block polymer finally selected in the present invention is preferably a polymer obtained by re-acetylating a PVA-based polymer component, and is preferably 5,000 to 1,000,000. The molecular weight of the polymer of the present invention is measured by the GPC method, and is determined by standard polystyrene conversion. In addition, vinyl alcohol
The degree of saponification of the toluene component can be determined by quantification of acetate residue by ¹ H-NMR.

The graft polymer or block polymer of the present invention has a wide range of properties by adjusting the composition and molecular weight of both components. Furthermore, by using the hydrophobicity of the polystyrene component, it is an amphiphilic resin that exhibits solubility and aqueous properties different from those of the PVA-based polymer alone, so it can be used as a processing agent for dispersants, resins, paper, fibers, etc. It is suitable for the use of. Further, it is also suitable for use as a component constituting a water-based ink, a water-based paint, a water-based adhesive, or the like or a base polymer.

[0050]

The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 A glass container provided with a three-way cock was prepared, and after purging with nitrogen, heated under a nitrogen gas atmosphere to remove water adsorbed in the glass container. 0.87 mol of styrene (hereinafter abbreviated as M), 1.0 M of methyl dichloroacetate, 8.0 mmol of 1-isobutoxyethyl acetate (hereinafter abbreviated as mM), and chlorobenzene were placed in a container, and the temperature in the system was reduced to 0 ml. When the temperature reached ° C, a toluene solution of EtAlCl ₂ was added (20 mM) to initiate polymerization. After 10 hours, a toluene solution of a partially saponified polyvinyl acetate (250 mer, 10% saponified) (10% by weight (hereinafter abbreviated as wt%))
Was added so that the number of OH group units in the saponified polyvinyl acetate became twice the amount of EtAlCl ₂ , and the reaction was stopped. The partially saponified polyvinyl acetate used as a terminator was used after removing impurities such as a base in advance, freeze-drying with benzene, and dehydrating and purifying. A few hours after the reaction was stopped, the solution was diluted with dichloromethane, and the initiator residue was removed by washing with water. Thereafter, the solution was concentrated and dried under reduced pressure to collect the produced graft polymer. Further, in order to confirm the molecular weight of the branch component of the graft polymer, the polymerization was stopped by adding methanol instead of partially saponified polyvinyl acetate, and the resulting polystyrene was recovered, followed by gel permeation chromatography (hereinafter referred to as GPC). In chloroform, 4
The ratio (Mw / Mn) of the weight average molecular weight (hereinafter abbreviated as Mw) to the number average molecular weight (hereinafter abbreviated as Mn) measured at 0 ° C.) was 1.46 and Mn was 7000. . The rate of grafting of the growing cations of polystyrene to the polymer terminator was examined by GPC results of the resulting polymer and extraction experiments. As a result, under the above conditions, the homopolymer of polystyrene is about 30%, and the remaining about 70%
Was found to be grafted to polyvinyl alcohol. The structure of the graft polymer is ¹ H-NM
Considered by R. 1.6-1.9 ppm of main chain methylene derived from partially saponified polyvinyl acetate, 2.1 pp
m, 4.8-5.0 ppm main chain methine, polystyrene 1.3-1.6 ppm main chain methylene, 6.2-7.3 ppm benzene ring proton absorption. The structure of the graft polymer was confirmed.
Next, a saponification reaction of the produced graft polymer is performed,
The backbone polymer was converted to polyvinyl alcohol. In the saponification reaction, the resulting graft polymer was dissolved in methanol (10 wt%), a small amount of a diluted sodium hydroxide aqueous solution was added dropwise, and the mixture was stirred at room temperature overnight. The product was dissolved in toluene and then reprecipitated several times using a methanol / water system for purification. The degree of saponification of the polyvinyl alcohol unit which is a trunk component in the obtained graft polymer was ¹ H-N
It was almost 100% as measured by MR. The solubility of the graft polymer before saponification is
It was soluble in acetone, dimethyl sulfoxide and the like, but was insoluble in water. On the other hand, the graft polymer after saponification is
Dissolution behavior unique to the graft polymer was observed, such as being soluble in toluene and chloroform, but insoluble in acetone and dimethyl sulfoxide.

Example 2 A glass container equipped with a three-way cock was prepared, and after replacement with nitrogen, heated in a nitrogen gas atmosphere to remove adsorbed water in the glass container. T-Butyl vinyl ether (0.76
M), tetrahydrofuran (1.0 M), 1-trimethylsiloxyethyl acetate (4.0 mM) and hexane were added. When the temperature in the system reached -20 ° C, Et was added.
A hexane solution of _1.5 AlCl _1.5 (20 mM) was added to initiate polymerization. After 57 hours, hydrochloric acid-methanol was added for deprotection. Furthermore, after washing with a 0.6 N hydrochloric acid aqueous solution to remove an initiator residue and neutralizing with a dilute sodium hydroxide aqueous solution, the reaction solution is concentrated and dried under reduced pressure to obtain a poly (t-butyl vinyl ether) having a hydroxyl group at one end. ) Was recovered. The polymerization rate was 96%, the terminal hydroxyl group introduction rate determined by NMR was 95%, and the degree of polymerization after deprotection with hydrogen bromide and conversion to polyvinyl alcohol was 179. next,
After polymerizing styrene in the same manner as in Example 1, the above-mentioned poly (t-butyl vinyl ether) was used as a reaction terminator.
(10 wt% (hereinafter abbreviated as wt%)) was added so that the number of units of terminal hydroxyl groups of poly (t-butyl vinyl ether) was twice the amount of EtAlCl ₂ , and the reaction was stopped. A few hours after stopping the reaction, methanol was added, and the solution was further diluted with dichloromethane.
The initiator residue was removed by washing with water. Then the solution is concentrated,
The resulting block polymer was recovered by drying under reduced pressure. Further, in order to confirm the molecular weight of the polystyrene component of the block polymer, the polymerization was stopped by adding methanol instead of poly (t-butyl vinyl ether), and the obtained polystyrene was recovered, and then Mw measured by GPC.
And the ratio of Mn (Mw / Mn) was 1.45 and Mn was 7,500. Next, 1.0 g of the obtained block polymer composed of poly (t-butyl vinyl ether) and polystyrene was dissolved in 100 ml of toluene, and sufficiently stirred while blowing hydrogen bromide gas in an ice bath at 0 ° C. About 10 minutes after the start of the reaction, the produced polyvinyl alcohol / polystyrene block polymer was precipitated and the inside of the system became cloudy. After blowing hydrogen bromide gas for further 20 minutes, the precipitated polymer was separated by filtration, neutralized and washed with ammoniacal methanol and methanol, and dried under reduced pressure to obtain a polyvinyl alcohol / polystyrene block polymer. From the analysis of the dissolved components in the filtrate, it was found that under the above conditions, the homopolymer of polystyrene was about 30%, and the remaining 70% was a block polymer with polyvinyl alcohol. The structure of the block polymer was confirmed by ¹ H-NMR. Further, the degree of saponification of the vinyl alcohol unit was measured by ¹ H-NMR and found to be 99%. The solubility of the block polymer before deprotection was soluble in toluene, chloroform, acetone, dimethyl sulfoxide and the like, but insoluble in water.
On the other hand, the block polymer after deprotection was soluble in toluene and chloroform, but was insoluble in acetone and dimethyl sulfoxide.

[0053]

The polyvinyl alcohol-based graft polymer, polyvinyl alcohol-based diblock polymer and polyvinyl alcohol-based triblock polymer of the present invention are:
It is a polyvinyl alcohol-based polymer having a hydrophobic component and having high industrial utility. According to the production method of the present invention, the above graft polymer, diblock polymer,
Triblock polymers can be easily produced.

Continued on the front page F term (reference) 4J027 AA08 AJ01 AJ06 BA04 CD08 CD09 4J031 AA13 AA15 AB02 AC04 AD01 AE03 AE11 AF07 AF12 AF13 AF16 4J100 AA02Q AB03R AB07R AD02P AD03Q AE06Q AE09Q AL09CA03 CA03 CA01 FA06 FA19 FA28 HA61 HC29 JA01 JA03 JA07

Claims (7)

[Claims] 1. A polyvinyl alcohol having a polyvinyl alcohol-based polymer as a trunk component and a polystyrene-based polymer as a branch component, wherein the trunk component and the branch component are bonded via an ether bond. Graft polymer. 2. A composition comprising a component comprising a polyvinyl alcohol-based polymer and a component comprising a polystyrene-based polymer, wherein the polyvinyl alcohol-based polymer component and the polystyrene-based polymer component are bonded via an ether bond. A polyvinyl alcohol-based diblock polymer or a polyvinyl alcohol-based triblock polymer. 3. The polyvinyl alcohol graft polymer according to claim 1, wherein the ratio between the number average molecular weight and the weight average molecular weight of the polystyrene polymer is 1.5 or less and the number average molecular weight is 500 or more. 4. The polyvinyl alcohol diblock polymer according to claim 2, wherein the ratio between the number average molecular weight and the weight average molecular weight of the polystyrene polymer is 1.5 or less and the number average molecular weight is 500 or more. Polyvinyl alcohol triblock polymer. 5. A method for producing a polyvinyl alcohol-based diblock polymer, a polyvinyl alcohol-based triblock polymer, or a polyvinyl alcohol-based graft polymer comprising a polyvinyl alcohol-based polymer block and a polystyrene-based polymer block, wherein the polystyrene-based polymer is cationically prepared. Synthesized by a polymerization method, and a polyvinyl alcohol-based polymer containing one or more hydroxyl groups in the polymer terminal or in the polymer as a terminator for this polymerization is allowed to coexist during the polymerization of the polystyrene-based polymer,
Alternatively, a method for producing a polyvinyl alcohol-based diblock polymer, a polyvinyl alcohol-based triblock polymer, or a polyvinyl alcohol-based graft polymer, which is added after the polymerization reaction. 6. A method for producing a polyvinyl alcohol-based diblock polymer, a polyvinyl alcohol-based triblock polymer or a polyvinyl alcohol-based graft polymer comprising a polyvinyl alcohol-based polymer block and a polystyrene-based polymer block, wherein the polystyrene-based polymer is cationically prepared. Whether an ethylene-vinyl alcohol copolymer containing one or more hydroxyl groups in the polymer terminal or in the polymer as a terminator of the polymerization is allowed to coexist during the polymerization of the polystyrene polymer by a polymerization method. Or a method for producing a polyvinyl alcohol-based diblock polymer, a polyvinyl alcohol-based triblock polymer, or a polyvinyl alcohol-based graft polymer, which is added after a polymerization reaction. 7. A polymer constituting a polystyrene-based polymer block obtained by a cationic polymerization method, wherein the ratio between the weight average degree of polymerization and the number average degree of polymerization is 1.5 or less, and the number average molecular weight is 500 or more. The method for producing a polyvinyl alcohol-based diblock polymer, a polyvinyl alcohol-based triblock polymer, or a polyvinyl alcohol-based graft polymer according to claim 5 or 6.