JP2002275211A - Method for producing polyvinyl alcohol-based polymer having polymerizable double bond in side chain - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for simply and profitably producing a polyvinyl alcohol-based polymer having polymerizable double bonds in side chains. SOLUTION: This method for producing the polyvinyl alcohol-based polymer having the polymerizable double bonds in the side chains is characterized by subjecting 100 pts.wt. of a polyvinyl alcohol-based polymer and 0.01 to 100 pts.wt. of a compound having a hydroxyl group-reacting group and a polymerizable double bond in the same molecule to a mixing, melting and kneading.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a polyvinyl alcohol-based polymer having a polymerizable double bond in a side chain.

[0002]

2. Description of the Related Art Heretofore, polyvinyl alcohol-based polymers having a polymerizable double bond in the side chain have been known as polyvinyl alcohol-based polymers (hereinafter, referred to as PVA-based polymers). Has been post-modified with a reactive compound having a polymerizable double bond. PVA
Post-modification of the system polymer is usually carried out in dimethyl sulfoxide (hereinafter sometimes referred to as DMSO), water or a mixed solution of water and alcohol.

[0003] For example, Japanese Patent Application Laid-Open No. 62-32110,
JP-A-1-250923, JP-A-4-25570
No. 2 discloses a technique for introducing a polymerizable double bond ((meth) acryloyl group) into a PVA-based polymer in a DMSO solution. DMSO, an aprotic solvent
The reaction for introducing a polymerizable double bond into a PVA-based polymer in a solution is extremely efficient, but finally, a high boiling point DM
Since it is necessary to remove SO, the process using DMSO becomes extremely complicated as a whole. In addition, Japanese Patent Application Laid-Open No.
Polymerizable double bond ((meth)) to PVA polymer in aqueous solution
Acryloyl group). However, the reaction for introducing a polymerizable double bond in an aqueous solution requires a large amount of a catalyst, and thus has a problem that a great deal of labor is required to remove the used catalyst. Furthermore, in the method of introducing a polymerizable double bond into a PVA-based polymer in DMSO or an aqueous solution, the P
In order to obtain a VA polymer as a powder, it is necessary to perform a reprecipitation operation using a large amount of a solvent, which causes a great increase in cost. Such a problem is caused by the post-modification in a mixed solvent containing water, for example, a mixed solvent of water and alcohol disclosed in Japanese Patent Application Laid-Open No. 4-283749 and the like. The same applies when a double bond is introduced.

In order to avoid the above problems, for example, JP-A-62-267302 discloses that a polymerizable double bond ((meta) is prepared by suspending a PVA polymer in an aprotic solvent. ) After the hydroxyl group of the PVA polymer is post-modified with a reactive monomer having an acryloyl group), the solid is collected as it is, and unnecessary unreacted substances, catalysts and by-products are removed by washing with an organic solvent. A method utilizing such a heterogeneous reaction is shown. This method eliminates the need for a reprecipitation step using a large amount of solvent and can reduce the cost.However, since the reaction is performed in a heterogeneous state, the introduction of the polymerizable double bond tends to be nonuniform, and the reaction yield is low. It is hard to say that the rate is high,
There is also a problem that a relatively large amount of an organic solvent must be used in the washing step after the reaction.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a method for easily and economically producing a PVA-based polymer having a polymerizable double bond in a side chain. Is to do.

[0006]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors to achieve the above object, a compound having a group reactive with a hydroxy group and a polymerizable double bond in the same molecule was converted to a PVA-based compound. The present inventors have found that a PVA-based polymer having a polymerizable double bond in a side chain can be easily and economically produced by blending with a polymer and melt-kneading, thereby completing the present invention.

That is, the present invention provides a PVA-based polymer 10
0 parts by weight of a compound having a group reactive with a hydroxy group and a polymerizable double bond in the same molecule is 0.0
The present invention relates to a method for producing PVA having a polymerizable double bond in a side chain, wherein 1 to 100 parts by weight are blended and melt-kneaded.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As a PVA polymer used in the present invention, a polyvinyl ester polymer obtained by radical polymerization of a vinyl ester monomer is saponified,
Those having a vinyl ester unit as a vinyl alcohol unit can be used. Examples of the vinyl ester monomer include vinyl formate, vinyl acetate, vinyl propionate, vinyl berelate, vinyl laurate, vinyl stearate, vinyl benzoate, vinyl pivalate,
Examples thereof include vinyl versatate, and among them, vinyl acetate is preferred.

Further, when radical-polymerizing the above-mentioned vinyl ester-based monomer, if necessary, a monomer copolymerizable with the above-mentioned vinyl ester-based monomer may be copolymerized within a range not to impair the effects of the present invention. Can also.
Examples of such a monomer copolymerizable with a vinyl ester monomer include ethylene, propylene, 1-
Olefins such as butene and isobutene; acrylic acid,
Salts of unsaturated acids such as methacrylic acid, crotonic acid, phthalic acid, maleic acid, itaconic acid or monoalkyl esters or dialkyl esters having 1 to 18 carbon atoms; acrylamide, N-alkylacrylamide having 1 to 18 carbon atoms, N, N-dimethylacrylamide, 2-
Acrylamides such as acrylamidopropanesulfonate, acrylamidopropyldimethylamine or an acid salt thereof; methacrylamide, N-alkylmethacrylamide having 1 to 18 carbon atoms, N, N-dimethylmethacrylamide, 2-methacrylamidopropanesulfonate ,
Methacrylamides such as methacrylamidopropyldimethylamine or an acid salt thereof; N-vinylpyrrolidone;
N-vinylamides such as N-vinylformamide and N-vinylacetamide; vinyl cyanides such as acrylonitrile and methacrylonitrile; alkyl vinyl ethers and hydroxyalkyl vinyl ethers having an alkyl chain having 1 to 18 carbon atoms Vinyl ethers such as vinyl chloride, alkoxyalkyl vinyl ether; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, and vinyl bromide; vinyl silanes such as trimethoxy vinyl silane; allyl acetate; Allyl compounds such as allyl, allyl alcohol and dimethylallyl alcohol can be mentioned. The amount of these polymerizable monomers used is usually 0.0
01 to 80 mol%.

The degree of polymerization of the PVA polymer used in the present invention may be appropriately selected according to the intended use, but is usually preferably from 200 to 2,000, and more preferably from 250 to 2,000.
It is preferably from 1500 to 1500. When the degree of polymerization is less than 200, the strength of the molded article, particularly the impact strength at low temperature, becomes extremely low. On the other hand, when the degree of polymerization is greater than 2,000, the melt viscosity of the resin is high, so that the fluidity is poor, and in molding, defective products such as underfilling occur frequently, making molding difficult. Here, the polymerization degree is obtained by measuring the intrinsic viscosity [η] (dl / g) of a completely saponified PVA-based polymer in water at 30 ° C. and calculating using the equation represented by the following equation (1). It is.

Degree of polymerization = ([η] × 10 ³ /8.29) ^{(1 / 0.62)} (1)

The degree of saponification of the PVA-based polymer used in the present invention can be arbitrarily selected according to the application and is not particularly limited.
It is preferably 80 to 100 mol%, and 85 to 10 mol%.
It is particularly preferred that it is 0 mol%. If the saponification degree is lower than 80 mol%, the mechanical properties of the obtained molded article, particularly the strength and elastic modulus when left under high humidity, are not preferable.

In the present invention, a compound having a group reactive with a hydroxy group and a polymerizable double bond in the same molecule is used. Examples of the group reactive with a hydroxy group referred to in the present specification include reactive groups such as a carboxyl group, a hydroxy group, an ester group, an ether group, an isocyanate group, and a protected isocyanate group. It is preferable to use at least one type of reactive group selected from the group consisting of: and more preferably an ester group or an isocyanate group.

Examples of the compound having a hydroxyl group-reactive group and a polymerizable double bond in the same molecule include acrylic acid, methacrylic acid,
A compound having a carboxyl group such as cinnamic acid and a polymerizable double bond in the same molecule; a compound having a hydroxy group such as N-methylolacrylamide, N-methylol methacrylamide and cinnamic alcohol and a polymerizable double bond in the same molecule. (Meth) acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate;
Or a compound having an ester group and a polymerizable double bond in the same molecule such as methyl cinnamate, ethyl cinnamate, and propyl cinnamate derived from a compound having a cinnamic acid skeleton;
Has an ester group such as hydroxyethyl acrylate, hydroxyethyl methacrylate, glycerin acrylate, diglycerin acrylate, glycerin methacrylate, diglycerin methacrylate, a hydroxy group and a polymerizable double bond in the same molecule. Compounds; compounds having an ether group and a polymerizable double bond in the same molecule such as N-methylol (meth) acrylamide methyl ether and N-methylol (meth) acrylamidoethyl ether; acryloyl isocyanate, methacryloyl isocyanate, acryloyl isocyanate-t- Compound having an isocyanate group and a polymerizable double bond in the same molecule, such as butyl, methacryloyl isocyanate-t-butyl and ethyl methacrylate isocyanate. A compound having an isocyanate group protected by an alcohol such as methyl methacrylylcarbamate and ethyl methacrylylcarbamate and a polymerizable double bond in the same molecule; amines such as pyrazole and dimethylpyrazole; ε-caprolactam Such as lactams, oximes such as cyclohexanone oxime and the like, and compounds having a protected isocyanate group and a polymerizable double bond in the same molecule such that an isocyanate group is generated by heat, and the like. Or a combination of two or more of them. Among these compounds, a compound having an ester group such as hydroxyethyl (meth) acrylate and a polymerizable double bond in the same molecule, or an isocyanate group such as (meth) acryloyl isocyanate-t-butyl and a double bond are used. Compounds having the same molecule are preferable in terms of reaction efficiency.

The amount of the compound having a group reactive with a hydroxy group and a polymerizable double bond in the same molecule is as follows:
0.01 to 100 parts by weight per 100 parts by weight of the PVA polymer
Parts by weight, preferably 0.01 to 50 parts by weight,
The content is more preferably from 01 to 30 parts by weight.

According to the present invention, after a compound having a group reactive with a hydroxy group and a polymerizable double bond in the same molecule is added to a PVA-based polymer, a resin such as a melt extruder is melted. By melt-kneading using a kneading apparatus, a PVA-based polymer having a polymerizable double bond in a side chain can be produced.

The temperature for melt-kneading is usually from 130 to 2
It is preferably carried out at a temperature in the range of 80 ° C.,
50 ° C is more preferred, and 170 to 220 ° C is even more preferred. When the temperature is lower than 130 ° C., melt kneading may be difficult. On the other hand, when the temperature is higher than 280 ° C., the PVA-based polymer may be decomposed or the obtained PVA-based polymer may be colored.

In the production method of the present invention, in order to prevent the decomposition and coloring of the PVA-based polymer by lowering the temperature during melt-kneading, it is possible to further melt-knead the PVA with a plasticizer usually used. is there. Examples of usable plasticizers include polyhydric alcohols such as glycerin, diglycerin, polyethylene glycol, polypropylene glycol, and sorbitol; compounds obtained by adding ethylene oxide to these polyhydric alcohols; water; saccharides; polyethers; Compounds and the like can be mentioned, and one or more of these can be used in combination. The use amount of these plasticizers is usually 1 to 300 parts by weight based on 100 parts by weight of the PVA-based polymer, and 1 to 20 parts by weight.
0 parts by weight is more preferable, and 1 to 100 parts by weight is further preferable.

In the production method of the present invention, a polymerization inhibitor is further added in order to prevent a compound having a polymerizable double bond or a PVA-based polymer from being thermally polymerized by heating during melt-kneading to form a gel. It is also possible to perform melt kneading in the state. Examples of usable polymerization inhibitors include phenolic polymerization inhibitors such as hydroquinone and hydroquinone monomethyl ether, phenothiazine, and N, N-diphenylparaphenylenediamine. The compounding amount of the polymerization inhibitor is preferably 0.00001 to 10 parts by weight based on 100 parts by weight of the PVA-based polymer.
0001 to 1 part by weight is more preferred.

In the production method of the present invention, the PVA-based polymer 1
0.003 to 0.00 parts by weight of alkali metal ion
It is preferable to use a PVA-based polymer contained in a proportion of 1 part by weight, because the thermal degradation, thermal decomposition, gelation, and coloring of the PVA-based polymer are further suppressed during melt-kneading. Examples of the alkali metal ion include potassium ion and sodium ion. These are mainly salts of lower fatty acids such as acetic acid and propionic acid, or when the PVA polymer has a carboxyl group or a sulfonic acid group. Exists as salts of these groups. The content of the alkali metal ion in the PVA-based polymer can be measured by an atomic absorption spectrophotometer using a sample in which the PVA-based polymer is ashed and dissolved in an acid.

Further, in the production method of the present invention, in order to promote the introduction of a polymerizable double bond into the PVA-based polymer, it is possible to melt-knead the mixture with an acidic or basic substance as a catalyst. It is possible. Examples of usable acidic substances include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid; organic acids such as formic acid, acetic acid, oxalic acid, and p-toluenesulfonic acid; pyridinium p-toluenesulfonic acid, and ammonium chloride. Salts; Lewis acids such as zinc chloride, aluminum chloride, iron trichloride, tin dichloride, tin tetrachloride, boron trifluoride diethyl ether complex, and the like, and one or a combination of two or more thereof. Can be used. Examples of usable basic substances include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; alkali metal carbonates such as sodium carbonate and potassium carbonate; metal oxides such as barium oxide and silver oxide; Alkali metal hydrides such as sodium hydride and potassium hydride; alkali metal alkoxides such as sodium methoxide and sodium ethoxide; alkali metal amides such as sodium amide and potassium amide;
More than one species can be used in combination. Usually, the amount of the acidic substance or the basic substance is preferably 0.0001 to 5 parts by weight based on 100 parts by weight of the PVA-based polymer.

The PVA-based polymer having a polymerizable double bond in the side chain obtained by the production method of the present invention comprises a photoinitiator,
By combining with sensitizers, polymerizable monomers, etc., it can be easily cured with energy rays such as ultraviolet rays and electron beams, and manufacture paints, inks, adhesives, printing plates, etching resists, solder resists, etc. It can be suitably used as a raw material.

[0023]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention.

Example 1 A polymerization degree of 500, a saponification degree of 97.8 mol%, and 100 parts by weight of PVA-based polymer powder (containing 0.2 parts by weight of sodium ion with respect to 100 parts by weight of the PVA-based polymer) ,
30 parts by weight of water, 10 parts by weight of hydroxyethyl methacrylate, and 0.001 part by weight of phenothiazine were added, and the mixture was left for one day. Then, after melt-kneading under the following conditions, pellets were produced. (Melting and kneading conditions) Extruder: Labo Plastomill manufactured by Toyo Seiki Co., Ltd. Screw: Biaxial same direction, 25 mmφ, L / D = 26 Screw rotation speed: 60 rpm Set temperature (cylinder part): 200 ° C. Set temperature (die part) ): 110 ° C. About the obtained modified PVA-based polymer, d6-DMSO
When ¹ H-NMR measurement was performed with the solvent, 5.6 to
Signals derived from the polymerizable double bond were observed in the regions of 5.7 ppm and 5.95 to 6.05 ppm. This signal and the signal derived from the PVA-based polymer (3.8 to 4.2)
(ppm), it was confirmed that 3.1 mol% of polymerizable double bonds had been introduced into the PVA-based polymer. In addition, PVA by heating during melt kneading
Gelation, deterioration, and coloring of the polymer did not occur, and a modified PVA polymer of excellent quality was obtained.

Example 2 Pellets were produced in the same manner as in Example 1, except that 100 parts by weight of glycerin was further added to 100 parts by weight of the PVA-based polymer and melt-kneaded. The amount of the polymerizable double bond introduced into the PVA-based polymer was 2.2 mol%. Furthermore, gelation, deterioration, and coloring of the PVA-based polymer due to heating during melt-kneading did not occur, and a modified PVA-based polymer of excellent quality was obtained.

Example 3 Pellets were produced in the same manner as in Example 1 except that hydroxyethyl acrylate was used instead of hydroxyethyl methacrylate. The amount of the polymerizable double bond introduced into the PVA-based polymer was 1.9 mol%. Furthermore, gelation, deterioration, and coloring of the PVA-based polymer due to heating during melt-kneading do not occur, and denatured P of excellent quality is obtained.
A VA polymer was obtained.

Example 4 Pellets were produced in the same manner as in Example 1, except that methacrylyl isocyanate-t-butyl was used instead of hydroxyethyl methacrylate. The amount of the polymerizable double bond introduced into the PVA-based polymer was 3.3 mol%. Furthermore, gelation, deterioration, and coloring of the PVA-based polymer due to heating during melt-kneading did not occur, and a modified PVA-based polymer of excellent quality was obtained.

Reference Example 1 For each of the PVA polymers having a polymerizable double bond in the side chain obtained in Examples 1 to 4, 5 parts by weight of the polymer was dissolved in water to prepare a 10% aqueous solution. Then, Irgacure 2959, which is a water-soluble photoinitiator, was added to each aqueous solution at a concentration of 0.1 g / ml.
When 005 parts by weight were mixed and ultraviolet irradiation was performed, all the aqueous solutions were cured and gelled.

[0029]

According to the production method of the present invention, a PVA polymer having a polymerizable double bond in a side chain can be produced in a short time and at low cost, and a resin form can be easily produced. Can be manufactured.

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Claims (5)

[Claims] 1. A compound having a group reactive with a hydroxy group and a polymerizable double bond in the same molecule in an amount of from 0.01 to 100 parts by weight of a polyvinyl alcohol-based polymer.
100 parts by weight, characterized by being melt-kneaded,
A method for producing a polyvinyl alcohol-based polymer having a polymerizable double bond in a side chain. 2. The group having reactivity with a hydroxy group is at least one reactive group selected from the group consisting of a carboxyl group, a hydroxy group, an ester group, an ether group, an isocyanate group and a protected isocyanate group. Item 4. The method for producing a polyvinyl alcohol-based polymer having a polymerizable double bond in a side chain according to Item 1. 3. The polyvinyl alcohol-based polymer having a polymerizable double bond in a side chain according to claim 1 or 2, further comprising 1 to 300 parts by weight of a plasticizer based on 100 parts by weight of the polyvinyl alcohol-based polymer. Production method. 4. A polymerization inhibitor is added in an amount of 0.00001 to 10 based on 100 parts by weight of the polyvinyl alcohol-based polymer.
The method for producing a polyvinyl alcohol-based polymer having a polymerizable double bond in a side chain according to any one of claims 1 to 3, which is blended in parts by weight. 5. The polyvinyl alcohol-based polymer according to claim 1, wherein the polyvinyl alcohol-based polymer is a polyvinyl alcohol-based polymer containing 0.003 to 1 part by weight of an alkali metal ion with respect to 100 parts by weight of the polyvinyl alcohol-based polymer. The method for producing a polyvinyl alcohol-based polymer having a polymerizable double bond in a side chain according to any one of the preceding claims.