JPH08188621A - Production of resin composition - Google Patents

Abstract

PURPOSE: To produce a resin composition improved in transparency, antistatic properties, flexibility, water resistance and water absorptivity by saponifying a vinyl ester polymer in the presence of a polymer having a functional group selected from silicon-containing groups convertible into silanol groups in the presence of water at one terminal. CONSTITUTION: A polymer having a double bond at one terminal and 1-10 equivalents, per equivalent of the double bonds, of a silane are reacted with each other at a room temperature to 300 deg.C for 1min to 48hr to obtain a polymer (A) having a silicon-containing functional group (e.g. a group of formula I, II or III) convertible into a silanol group of formula IV, V or VI in the presence of water at one terminal. 100 pts.wt. vinyl ester polymer (B), 1-100 pts.wt. component A and 1-1000mmol, per mol of component B, of a catalyst are mixed with each other, the mixture is subjected to a saponification reaction at 10-130 deg.C for 5min to 3hr in a solvent, and the obtained gel is ground and dried to obtain a resin composition.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a resin composition having excellent compatibility and transparency.

[0002]

2. Description of the Related Art Polyvinyl alcohol polymer (hereinafter referred to as P
(Abbreviated as VA) is excellent in film-forming property, transparency and strength, and therefore, it is a paper modifier such as a coating agent for paper and an internal additive for paper, an adhesive agent for paper, wood and inorganic substances, It is used in a wide range of applications including molded products such as warp sizing agents, various films and sheets. However, PVA has the problems that the physical properties change due to moisture absorption, especially the change in mechanical properties is large, and the water resistance is poor. For example, when used as a molded product or a film, there is a problem that brittle cracks occur at low temperature and low humidity, and conversely, elastic modulus becomes too low at high temperature and high humidity. In order to improve these problems, a method of blending a plasticizer or another type of polymer has been conventionally used, but when a plasticizer is added, the content of the plasticizer decreases with time. The content of the plasticizer was reduced by long-term use, and problems such as film cracking and cracking often occurred due to lack of flexibility under low humidity in winter. In addition, when PVA and another type of polymer are blended, there is almost no compatibility between them, so that the molded article or film made of these blends has a markedly reduced mechanical property or transparency. There was a problem of a large drop.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a resin composition containing PVA, which has excellent compatibility and transparency, as one component.

[0004]

DISCLOSURE OF THE INVENTION The present inventors have found that in the presence of a polymer (A) having at one end a functional group selected from a silicon-containing group that can be converted into a silanol group in the presence of water, vinyl A method for producing a resin composition, which is characterized by saponifying an ester polymer (B), has been found, and the present invention has been completed.

In the present invention, in the presence of the component (A),
It is surprising that a resin composition having excellent compatibility and good transparency can be obtained by saponifying the component (B). It is considered that this is because the above-mentioned functional group of the polymer (A) and the hydroxyl group produced by saponification of the polymer (B) are bonded by a transesterification reaction.

The vinyl ester polymer (B) of the present invention includes homopolymers and copolymers of vinyl esters such as vinyl formate, vinyl acetate, vinyl propionate, vinyl versaticate and vinyl pivalate.
Further, the vinyl ester-based polymer of the present invention may be copolymerized with another unsaturated monomer copolymerizable with the vinyl ester as long as the effect of the present invention is not impaired. As the unsaturated monomer, olefins other than ethylene, such as propylene, 1-butene and isobutene; unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid and maleic anhydride, or salts thereof, or Carbon number 1
18 mono- or dialkyl esters; acrylamide, N-alkyl acrylamide having 1-18 carbon atoms,
N, N-dimethylacrylamide, 2-acrylamidopropanesulfonic acid or its salt, acrylamidopropyldimethylamine or its acid salt or its 4
Acrylamides such as primary salts; methacrylamide, N-alkylmethacrylamides having 1 to 18 carbon atoms, N, N-dimethylmethacrylamide, 2-methacrylamidopropanesulfonic acid or its salts, methacrylamidopropyldimethylamine or its acid salts. Alternatively, methacrylamides such as quaternary salts thereof; N-vinylpyrrolidone, N-
N-, such as vinylformamide and N-vinylacetamide
Vinylamides; allyl compounds such as allyl acetate, allyl chloride, allyl alcohol 8-hydroxy-1-octene; vinyl cyanides such as acrylonitrile and methacrylonitrile; alkyl vinyl ethers having 1-18 carbon atoms, hydroxyalkyl vinyl ethers, alkoxyalkyl Vinyl ethers such as vinyl ether; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride and the like. The degree of polymerization of the vinyl ester polymer (B) is not particularly limited, but the degree of polymerization of PVA obtained by completely saponifying the polymer is 5
0-30000 are preferable, 50-10000 are more preferable, 100-5000 are especially preferable.

The polymer (A) having a functional group selected from the silicon-containing groups which can be converted into a silanol group in the presence of water, which is used in the present invention, is a polymer which is converted into a silanol group in the presence of water. The polymer having a silicon-containing group is bonded to one end of the polymer by a silicon-carbon bond. In the present invention, the silanol group is represented by the following chemical formulas 1 to 3.

[0008]

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[0009]

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[0010]

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The silicon-containing group which can be converted into a silanol group in the presence of water (hereinafter simply referred to as a silicon-containing group) is hydrolyzed in the presence of water and is represented by the above chemical formulas 1 to 3. Any silicon-containing group that can be converted to a silanol group may be used, but as a representative example, a trialkoxysilyl group represented by the following chemical formula 4 and the following chemical formula 5
A dialkoxyalkylsilyl group represented by
And an alkoxydialkylsilyl group represented by

[0012]

[Chemical 4]

[0013]

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[0014]

[Chemical 6]

[In the formula, R ¹ , R ² and R ³ are aliphatic hydrocarbon groups (such as linear or branched alkyl groups having 1 to 20 carbon atoms or alkenyl groups), alicyclic hydrocarbon groups ( Cycloalkyl group, cycloalkenyl group, etc.), aromatic hydrocarbon group (phenyl group, biphenyl group, etc.), R
¹ , R ² and R ³ may be the same group or different. Further, R ¹ , R ² and R ³ may have other groups such as a carboxyl group and a halogen atom.
Specific examples of the silicon-containing group represented by the above Chemical Formulas 4 to 6 include trimethoxysilyl group, triethoxysilyl group, triisopropoxysilyl group, dimethoxymethylsilyl group, diethoxymethylsilyl group, methoxydimethylsilyl group, Examples thereof include an ethoxydimethylsilyl group.

In the present invention, the silicon-containing group which can be converted into a silanol group in the presence of water means the polymer (A).
In water or a mixed liquid of water and an organic solvent (toluene, xylene, acetone, etc.), for a reaction time of 10 minutes to 2 hours,
It means a group which can be converted into a silanol group when hydrolyzed under the reaction temperature of room temperature to 150 ° C.

The polymer (A) of the present invention is not particularly limited as long as it has at one end a functional group selected from silicon-containing groups which can be converted into silanol groups in the presence of water.
Methacrylic acid ester-based polymer, aromatic vinyl-based polymer, acrylamide-based polymer, methacrylamide-based polymer, N-vinylamide-based polymer, oxyalkylene-based polymer, vinyl ester-based polymer, vinyl cyanide-based polymer , Vinyl halide polymers, vinyl ether polymers and the like. The monomers constituting these polymers include methacrylic acid and its salts, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, n-dodecyl methacrylate, hydroxyethyl methacrylate, methacrylic acid. Methacrylic acids such as hydroxypropyl and monoglycerin methacrylate; aromatic vinyls such as styrene, α-methylstyrene, t-butylstyrene and vinylnaphthalene; N such as acrylamide and N-isopropylacrylamide
-Alkyl acrylamides, N, N-dimethyl acrylamide, acrylamides such as 2-acrylamidopropanesulfonic acid or salts thereof, acrylamidopropyldimethylamine or its acid salts or quaternary salts thereof; N such as methacrylamide, N-isopropyl methacrylamide, etc. -Methylmethacrylamides such as alkyl methacrylamide, N, N-dimethylmethacrylamide, 2-methacrylamidopropanesulfonic acid or its salts, methacrylamidopropyldimethylamine or its acid salts or their quaternary salts; N-vinylpyrrolidone, N -N-vinylamides such as vinylformamide and N-vinylacetamide; oxyalkylenes such as oxyethylene, oxypropylene and oxytetramethylene; vinyl formate, vinyl acetate, pr Vinyl esters such as vinyl pionate, vinyl versatate and vinyl pivalate; vinyl cyanides such as acrylonitrile and methacrylonitrile; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl fluoride and vinylidene fluoride; methyl. Examples thereof include vinyl ethers such as vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, methoxyethyl vinyl ether and the like. The molecular weight of the polymer (A) is not particularly limited, but is preferably 50 to 100,000, more preferably 100 to 50,000.

Next, a typical method for producing the polymer (A) having a silicon-containing group at one end used in the present invention will be described. The first production method; the polymer having a silicon-containing group at one end is
It is obtained by reacting a polymer having a double bond at one end with silanes. The introduction of the silicon-containing group is carried out by adding a silane to a polymer having a double bond at one end using a free radical initiator or a transition metal catalyst and a base catalyst under a nitrogen atmosphere. As silanes, trichlorosilane, methyldichlorosilane,
Ethyldichlorosilane, dimethylchlorosilane, trimethoxysilane, dimethoxymethylsilane, methoxydimethylsilane, ethoxydimethylsilane and the like are preferable. The charging amount of silanes is from 1 to 1 with respect to the double bond of the polymer.
A range of 0 equivalent is preferable. The reaction temperature is preferably room temperature to 300 ° C, more preferably 50 to 250 ° C. The reaction time is preferably 1 minute to 48 hours, more preferably 5 minutes to 24 hours. The type of silicon-containing group can be easily converted in the presence of water or alcohol. For example, a methoxydimethylsilyl group becomes a dimethylsilanol group by reacting with water, and a trichlorosilyl group becomes a trimethoxysilyl group by reacting with methanol.

Second production method: The polymer having a silicon-containing group at one end can be obtained by radically polymerizing a radical-polymerizable monomer in the presence of a thiol having the silicon-containing group. The thiol having a silanol group or a silicon-containing group as a raw material can be obtained by reacting a thiol having a double bond with a silane in a nitrogen atmosphere, and then adding an alcohol or water. As the thiol having a double bond, 2-propene-1-thiol,
2-Methyl-2-propene-1-thiol, 3-butene-1-thiol, 4-pentene-1-thiol and the like can be mentioned, among which 2-propene-1-thiol and 2-
Methyl-2-propen-1-thiol is preferred. As the silanes, the same ones as described above are used.
The addition amount of the silanes is preferably in the range of 10 to 10 equivalents with respect to the thiol having a double bond. The reaction conditions are preferably room temperature to 200 ° C. Examples of the solvent include ether solvents such as tetrahydrofuran (THF) and diglyme; saturated hydrocarbon solvents such as hexane, heptane, ethylcyclohexane and decalin. As alcohols added after the reaction, lower alcohols such as methanol and ethanol are preferable, and methanol is particularly preferable. The radical polymerization in the presence of the thiol having a silicon-containing group thus obtained can be carried out by a usual method. As the polymerization conditions, an azo or peroxide initiator is used, and the polymerization temperature is preferably in the range of room temperature to 150 ° C. The addition amount of the thiol having the functional group,
About 0.001 to 1 mmol per 1 g of the monomer is preferable. The method for adding the thiol is not particularly limited,
When using a monomer such as vinyl acetate or styrene that is easily chain-transferred as a monomer, it is preferable to add thiols sequentially during polymerization, and when using a compound that is difficult to chain-transfer such as methyl methacrylate, thiol is used. It is preferable to add it from the beginning.

The method for saponifying the vinyl ester polymer (B) in the presence of the polymer (A) having a functional group selected from silicon-containing groups at one end is not particularly limited, but an alkali catalyst or an acid is used. The usual method of saponification by a transesterification reaction using a catalyst and / or a direct saponification reaction is used. Examples of the solvent include alcohol solvents such as methanol, ethanol, butanol, allyl alcohol, and benzyl alcohol, or the alcohol solvent and aromatic solvents such as benzene, toluene, and chlorobenzene, ether solvents such as tetrahydrofuran and dioxane, and acetone. A mixed solvent with a solvent selected from dimethylformamide, dimethylacetamide, dimethylsulfoxide and N-methylpyrrolidone is used.
The concentration of the vinyl ester polymer (B) in the solvent is 1 to
A range of 70% by weight is preferred. As the saponification catalyst, hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide, sodium methylate, sodium ethylate,
Alkali metal alcoholates such as potassium methylate,
Examples thereof include alkali catalysts such as amines and acid catalysts such as benzenesulfonic acid and toluenesulfonic acid. The amount of the catalyst used is preferably 1 to 1000 mmole equivalent to the vinyl ester polymer. The saponification reaction temperature is not particularly limited, but is preferably 10 to 130 ° C, more preferably 30 to 80 ° C. The reaction is usually performed for 5 minutes to 3 hours. The addition amount of the polymer (A) is selected from the range of 1 to 100 parts by weight with respect to 100 parts by weight of the vinyl ester polymer (B), preferably 2 to 70 parts by weight, and more preferably 5 to 50 parts by weight. preferable.

[0021]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the following examples, "%" and "parts" mean "% by weight" and "parts by weight", respectively, unless otherwise specified.

The degree of polymerization of the polymer (B) in the examples is
The polymer was completely saponified and measured according to JIS-K-6726. Regarding the content of silicon-containing groups in the polymer (A) and the degree of saponification of PVA in the resin composition after saponification,
It was quantified by 270 MHz- ¹ H NMR. In addition, a Labo Plastomill (manufactured by Toyo Seiki) was used for melt kneading
The rotation was performed for 10 minutes. The surface electric resistance of the film was measured with an electric resistance measuring device (manufactured by HEWLETT PACKARD) after conditioning the film at 20 ° C. × 65% RH for 1 week.

Synthesis Example 1 Polyethylene group having a trimethoxysilyl group at one end
Recall synthesis; flat in a separable flask with a condenser
Polyethylene glycol monoallyl with an average molecular weight of 350
Ether (UNIOX PKA-5006; NOF Corporation)
Co., Ltd.) 50 parts, trimethoxysilane 17.46 parts
And chloroplatinic acid H₂PtCl₆・ 6H ₂O 0.002
Parts were charged and the atmosphere was replaced with nitrogen. This mixture at 70 ° C
Heated for 20 hours. After cooling the reaction mixture, vacuum
By distilling, the silicon-containing group content of 2.5 meq / g
Polyethylene glycol was obtained.

Synthesis Example 2 Synthesis of ethylene oxide-propylene oxide copolymer having dimethoxymethylsilyl group at one end; ethylene oxide-propylene oxide copolymer having an allyl group at one end and having an average molecular weight of 1600 in a separable flask equipped with a condenser. 150 parts of combined (Unisafe PKA-5015; NOF CORPORATION, molar ratio EO / PO = 75/25),
Dimethoxymethylsilane 11.46 parts, chloroplatinic acid H ₂
0.002 parts of PtCl ₆ .6H ₂ O and THF 20
0 part was charged and the atmosphere was replaced with nitrogen. This mixture at 70 ° C
It was heated to reflux for 40 hours. The reaction mixture was cooled and then distilled under reduced pressure to obtain a silicon-containing group content of 0.57 m.
An eq / g ethylene oxide-propylene oxide copolymer was obtained.

Synthesis Example 3 Synthesis of methoxy-3-mercaptopropyldimethylsilane 2-propene-1-thiol 100 was added to an autoclave.
Part, dimethylethoxysilane 140 parts and chloroplatinic acid H2PtCl6.6H2O 0.002 parts were charged, and
Stirred at C for 24 hours. The reaction mixture was cooled, 100 parts of methanol was added, the mixture was stirred at room temperature for 1 hour, and then distilled under reduced pressure to obtain methoxy-3-mercaptopropyldimethylsilane.

Synthesis Example 4 Synthesis of polymethylmethacrylate having methoxydimethylsilyl group at one end; 150 parts of methylmethacrylate and methoxy-3-mercapto obtained in Synthesis Example 3 were placed in a separable flask equipped with a condenser and a dropping funnel. 0.984 parts of propyldimethylsilane was charged and nitrogen substitution was carried out. Next, the temperature was raised to 80 ° C., and a separately prepared 0.23% toluene solution of azobisisobutyronitrile was first added at 1.3 parts, and then 0.43 parts was added every 30 minutes. 5
After a lapse of time, the mixture was cooled and the polymerization was stopped. The polymerization rate at this time was 49%. The obtained polymethylmethacrylate was reprecipitated with methanol and then dried to obtain polymethylmethacrylate having an average molecular weight of 25,000 having a methoxydimethylsilyl group at one end of 0.029 meq / g.

Synthesis Example 5 Synthesis of polystyrene having a methoxydimethylsilyl group at one end; 500 parts of styrene and methoxy-3-mercaptopropyldimethylsilane obtained in Synthesis Example 3 were placed in a separable flask equipped with a condenser and a dropping funnel. 0.
086 parts were charged and the atmosphere was replaced with nitrogen. Next, the temperature was raised to 120 ° C., and after adding 6.5 parts of a styrene solution of methoxy-3-mercaptopropyldimethylsilane 0.443% and azobiscyclohexanecarbonitrile 0.070%, 0.44 parts / min. Added in proportion. After 4 hours, the mixture was cooled to stop the polymerization. The polymerization rate at this time was 48%. The obtained polystyrene was reprecipitated with methanol and then dried to obtain polymethyl methacrylate having an average molecular weight of 66000 having a methoxydimethylsilyl group at one end of 0.014 meq / g.

Example 1 Polyvinyl acetate (average degree of polymerization: 1700, hereinafter abbreviated as PVAc) was added to methanol and stirred at 50 ° C.
After the temperature was raised to 1 to dissolve it, the solution was cooled to room temperature to prepare a methanol solution having a concentration of 30%. To 200 parts of this solution was added 6 parts of polyethylene glycol having a trimethoxysilyl group at one end of Synthesis Example 1, then 40
The mixture was saponified with 12 parts of a 10% NaOH methanol solution with stirring at 0 ° C to obtain a gel. After crushing this gel with a mixer, it was dried at 100 ° C. for 2 hours to obtain a resin composition. The saponification degree of the PVA-based polymer in this resin composition is N
It was 98.8 mol% as measured by MR. 100 parts of this resin composition was dissolved in 600 parts of water and cast on a rotary drum having a surface temperature of 75 ° C. to form a film, thereby obtaining a film having a dry thickness of 40 μm. This film was cut into 3 cm x 3 cm, embedded in diatomaceous earth, and allowed to stand in a constant temperature bath at 50 ° C for 30 days to remove the PE in the film.
The change in G content was investigated. When quantified by NMR,
The initial value of 20.1% was 19.6% even after 30 days, and P
There was almost no transfer of EG to diatomaceous earth.

Comparative Example 1 Example 1 was repeated except that unmodified PEG (molecular weight 300) was used instead of PEG having a trimethoxysilyl group at one end.
Saponification was carried out in the same manner as in 1. to obtain a resin composition having a PVA polymer saponification degree of 98.6 mol%. A film was prepared from this resin composition, embedded in diatomaceous earth and subjected to a standing test. The PEG content decreased from the initial 20.1% to 3.9%, and most of the PEG was transferred to diatomaceous earth.

Example 2 PVA modified with 3 mol% of sodium 2-acrylamido-2-methylpropanesulfonate instead of polyvinyl acetate
Saponification was performed in the same manner as in Example 1 except that c (average degree of polymerization 1700) was used, and the degree of saponification of the PVA-based polymer was 9
An 8.5 mol% resin composition was obtained. A film was prepared from this resin composition, embedded in diatomaceous earth and subjected to a standing test. The initial value of PEG was 20.2%, which was 19.8% even after 30 days, and there was almost no transfer of PEG to diatomaceous earth.

Comparative Example 2 Example 2 was repeated except that unmodified PEG (molecular weight 300) was used instead of PEG having a trimethoxysilyl group at one end.
Saponification was carried out in the same manner as above to obtain a resin composition having a saponification degree of the PVA polymer of 98.4 mol%. A film was prepared from this resin composition, embedded in diatomaceous earth and subjected to a standing test. The PEG content decreased from the initial 20.1% to 3.5%, and most of the PEG transferred to diatomaceous earth.

Example 3 Instead of PEG having a trimethoxysilyl group at one end, the ethylene oxide-propylene oxide copolymer having a dimethoxymethylsilyl group at one end obtained in Synthesis Example 2 was used and added 10% Saponification was performed in the same manner as in Example 1 except that 3 parts of a methanol solution of NaOH was used.
A resin composition having a saponification degree of the PVA polymer of 73.9 mol% was obtained. A film was prepared from this resin composition, embedded in diatomaceous earth and subjected to a standing test. The initial content of ethylene oxide-propylene oxide copolymer is 1
9.8% was 19.5% even after 30 days, and there was almost no transfer to diatomaceous earth.

Comparative Example 3 Implementation was carried out except that an ethylene oxide-propylene oxide copolymer having an allyl group at one end and an average molecular weight of 1600 was used instead of the ethylene oxide-propylene oxide copolymer having a dimethoxymethylsilyl group at one end. Saponification was carried out in the same manner as in Example 3 to obtain a resin composition having a degree of saponification of the PVA polymer of 74.2 mol%. A film was prepared from this resin composition, embedded in diatomaceous earth and subjected to a standing test. The content of ethylene oxide-propylene oxide copolymer is initially 20.2% to 5.1%
And most of the PEG was transferred to diatomaceous earth. From the above results, the composition of the present invention is useful as a PVA-based film material having no plasticizer migration.

Example 4 Allyl acetate 6 mol% modified PVAc (average degree of polymerization 5
50 parts of 30% methanol solution of 50) and 300 parts of 10% THF solution of polymethylmethacrylate having a methoxydimethylsilyl group at one end of Synthesis Example 4 are mixed, and 10% NaOH methanol solution 12 is stirred at 40 ° C. The mixture was saponified in parts to obtain a slurry-like mixture. This mixture was dried at 100 ° C. for 2 hours to obtain a resin composition. The saponification degree of the PVA-based polymer in this resin composition is N
It was 98.9 mol% as measured by MR.
20 parts of the resin composition and 80 parts of unmodified polymethylmethacrylate (Parapet G; manufactured by Kuraray Co., Ltd.) are mixed, melt-kneaded at 220 ° C. for 10 minutes using a Labo Plastomill, and then hot pressed at 230 ° C. Thickness of 50μm
Was obtained. The film has good transparency,
The surface resistivity measured after controlling the humidity at 20 ° C. × 65% RH for 1 week was 5.6 × 10 ¹¹ Ω / □.

Comparative Example 4 2-hydroxyethylthiyl was synthesized at one end using 0.468 parts of 2-mercaptoethanol in place of 0.984 parts of methoxy-3-mercaptopropyldimethylsilane in Synthesis Example 4. Example 4 except that a polymethylmethacrylate having a group (average molecular weight 25,000) is used.
Saponification was carried out in the same manner as in 1. to obtain a resin composition having a PVA polymer saponification degree of 98.6 mol%. When a film was prepared in the same manner as in Example 4, the film had poor transparency and became cloudy, and the surface resistivity measured after humidity conditioning at 20 ° C. × 65% RH for 1 week was 7.8 × 10 ^13. It was Ω / □.

Example 5 200 parts of a 30% methanol solution of PVAc modified with 5 mol% of ethyl vinyl ether (average degree of polymerization 450) and 600 parts of a 5% THF solution of polystyrene having a methoxydimethylsilyl group at one end of Synthesis Example 5 were added. Mix and 40 ℃
Saponification with 12 parts of 10% NaOH methanol solution while stirring at a PVA polymer saponification degree of 99.1 mol%
A resin composition of was obtained. 20 parts of the resin composition and unmodified polystyrene (Stylon 666; manufactured by Asahi Chemical Industry Co., Ltd.) 8
After mixing 0 parts and melt-kneading at 190 ° C. for 10 minutes, 21
A film having a thickness of 50 μm was obtained by hot pressing at 0 ° C. The film has good transparency, and is 20 ° C. ×
The surface resistivity measured after humidity conditioning at 65% RH for 1 week was 2.
It was 3 × 10 ¹¹ Ω / □.

Comparative Example 5 Synthesis of Example 5 was repeated except that 0.277 parts of 2-mercaptoethanol was used instead of 0.583 parts of methoxy-3-mercaptopropyldimethylsilane. Saponification was performed in the same manner as in Example 5 except that a polystyrene having a group (average molecular weight 64000) was used to obtain a resin composition having a PVA polymer saponification degree of 98.9 mol%. When a film was prepared in the same manner as in Example 5, the film had poor transparency and became cloudy, and the surface resistivity measured after humidity conditioning at 20 ° C. × 65% RH for 1 week was 5.7 × 10 ^12. It was Ω / □.

[0038]

From the above results, it is apparent that a molded article having good transparency and excellent antistatic property can be obtained by using the composition of the present invention. The resin composition obtained by the present invention is excellent in compatibility and transparency, and is useful for various applications. The resin composition of the present invention exhibits a very wide range of physical properties depending on the combination of the component (A) and the component (B), particularly the properties of the polymer (A), and examples thereof include the following. First, when the polymer (A) is water-soluble or water-dispersible and has a softening point sufficiently lower than room temperature, it has sufficient flexibility and impact resistance even at low temperature and low humidity, and has a plasticizer added. It is useful for molded articles such as water-soluble films, sheets, bottles, etc., whose physical properties do not change with time. On the other hand, when the softening point is sufficiently higher than room temperature, it is useful as a paper-working material that gives the paper elasticity.
Further, when the polymer (A) is water-insoluble and has a softening point sufficiently lower than room temperature, it is useful as a flexible material having water resistance such as a molded product such as a film or sheet or a photosensitive resin material. . On the other hand, when the softening point is sufficiently higher than room temperature, it is useful as a hygroscopic or water-absorbing molded article.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Naoki Fujiwara, 1621 Sakazu, Kurashiki-shi, Okayama Prefecture Kuraray Co., Ltd. (72) Inventor Toshiaki Sato 1621, Satsuki, Kurashiki-shi, Okayama (72) Inventor Hitoshi Maruyama 1621 Sakata, Kurashiki City, Okayama Prefecture Kuraray Co., Ltd.

Claims (1)

[Claims] 1. A vinyl ester polymer (B) is saponified in the presence of a polymer (A) having at one end a functional group selected from a silicon-containing group that can be converted into a silanol group in the presence of water. A method for producing a resin composition, comprising: