JPH0881609A - Production of molding - Google Patents

Abstract

PURPOSE: To obtain a molding such as films or sheets, excellent in compatibility, transparency, moldability, etc., by carrying out heat-melt molding of a resin composition composed of a PVA-based polymer and a polymer having a specific boron-containing group at one end. CONSTITUTION: A resin composition composed of (A) a PVA-based polymer and, (B) a polymer having a borinic acid group of formula I, a borinic acid group, a borinic group capable of converting into borinic acid group or boric acid group in the presence of water e.g. a borinic acid ester group, a borinic anhydride group of formula II or a borinic acid salt group of formula III R<1> , R<2> hydrocarbon group, an aromatic hydrocarbon group, etc.; M is an alkali (alkaline earth) metal} at one end as a functional group is subjected to heat melt molding to provide the objective molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a molded article 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 as molded products such as warp sizing agents and various films and sheets. The flexibility of PVA changes with temperature and humidity, and it becomes hard and brittle or soft and supple depending on the surrounding environment. In order to control this property, a method of blending a plasticizer or a polymer other than PVA has been used. However,
When a plasticizer is added, there is a problem that the content of the plasticizer decreases with time. Further, when PVA and a polymer other than PVA are blended, there is a problem that mechanical properties are significantly reduced or transparency is significantly reduced due to poor compatibility between the two.

[0003]

SUMMARY OF THE INVENTION The object of the present invention is to provide PV
It is an object of the present invention to provide a method for producing a molded article having excellent compatibility and transparency by hot-melt molding a resin composition containing A as a component.

[0004]

Means for Solving the Problems In order to solve the above problems, as a result of extensive studies, as a result, the polyvinyl alcohol polymer (A) and a boronic acid group or boric acid group in the presence of a boronic acid group, a boric acid group and water are added. A method for producing a molded article, which comprises subjecting a resin composition comprising a polymer (B) having a functional group selected from the group consisting of a boron-containing group that can be converted to an acid group to one end to hot-melt molding, The present invention has been completed.

The PVA (A) of the present invention contains a vinyl alcohol unit in an amount of 10 mol% or more, preferably 30 mol% or more,
More preferably, it is a polymer containing 50 mol% or more, and usually hydrolyzes a homopolymer or copolymer of vinyl ester or vinyl ether (saponification, alcoholysis, etc.).
It is obtained by doing. As the vinyl ester, vinyl acetate is mentioned as a typical example, and in addition, vinyl formate, vinyl propionate, vinyl pivalate, vinyl valerate, vinyl caprate, vinyl benzoate and the like can be mentioned. Examples of vinyl ethers include t-butyl vinyl ether, benzyl vinyl ether, trialkoxysilyl vinyl ether and the like.

The PVA (A) of the present invention may contain the following monomer units. As these monomer units,
Olefins other than ethylene, such as propylene, 1-butene, isobutene; unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, maleic anhydride, etc. or salts thereof, or mono-carbons having 1 to 18 carbon atoms. Or dialkyl esters; such as acrylamide, N-alkylacrylamide having 1 to 18 carbon atoms, N, N-dimethylacrylamide, 2-acrylamidopropanesulfonic acid or its salt, acrylamidopropyldimethylamine or its acid salt or its quaternary salt, etc. Acrylamide; Methacrylamide, N-alkylmethacrylamide having 1 to 18 carbon atoms, N, N-dimethylmethacrylamide, 2-methacrylamidopropanesulfonic acid or its salt, methacrylamidopropyldimethylamine or its Methacrylamides such as salt or a quaternary salt thereof; N- vinylpyrrolidone, N- vinylformamide, N- vinyl amides such as N- vinyl acetamide; allyl acetate, allyl chloride, allyl alcohol, 8
-Allyl compounds such as hydroxy-1-octene, vinyl cyanides such as acrylonitrile and methacrylonitrile, vinyl ethers such as alkyl vinyl ethers having 1 to 18 carbon atoms, hydroxyalkyl vinyl ethers and alkoxyalkyl vinyl ethers; vinyl chloride, vinylidene chloride, etc. Vinyl halides such as vinyl fluoride and vinylidene fluoride; dimethylallyl alcohol, vinyl ketone and the like.

The viscosity average (hereinafter abbreviated as polymerization degree) polymerization degree of PVA (A) used in the present invention is not particularly limited, but is preferably 50 to 30,000, and preferably 50 to 10.0.
00 is more preferable, and 100 to 5,000 is particularly preferable.

Polymers (B) having a functional group selected from the group consisting of a boronic acid group, a borinic acid group and a boron-containing group which can be converted into a boronic acid group or a borinic acid group in the presence of water used in the present invention (B). Is a boronic acid group, a borinic acid group, or a functional group selected from the group consisting of a boron-containing group that can be converted into a boronic acid group or a borinic acid group in the presence of water, is a boron-carbon bond at one end of the polymer It is a polymer having (preferably only one end). In the present invention, the boronic acid group is represented by the following chemical formula 1.

[0009]

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The boron-containing group which can be converted into a boronic acid group in the presence of water (hereinafter simply referred to as a boron-containing group) is a boron-containing group represented by the above chemical formula 1 by being hydrolyzed in the presence of water. Any boron-containing group that can be converted into an acid group may be used, and as a representative example, a boronic acid ester group represented by the following Chemical formula 2, a boronic acid anhydride group represented by the following Chemical formula 3, and a boron represented by the following Chemical formula 4 are represented. Acid base is mentioned.

[0011]

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[0012]

[Chemical 3]

[0013]

[Chemical 4]

{In the formula, X and Y are hydrogen atoms and have 1 to 2 carbon atoms.
0 aliphatic hydrocarbon group (linear or branched alkyl group, alkenyl group, etc.), alicyclic hydrocarbon group (cycloalkyl group, cycloalkenyl group, etc.), aromatic hydrocarbon group (phenyl group, biphenyl) Group),
X and Y may be the same group or different. Further, X and Y may be bonded. R ¹ , R ² and R ³ represent the same hydrogen atom, aliphatic hydrocarbon group, alicyclic hydrocarbon group and aromatic hydrocarbon group as those of X and Y above, and R ¹ , R ² and R ³
May be the same group or different. M represents an alkali metal or an alkaline earth metal. Further, the above X, Y, R ¹ , R ² and R ³ may have other groups such as a carboxyl group and a halogen atom. }

Specific examples of the boronic acid ester group represented by the above Chemical Formulas 2 to 4 include boronic acid dimethyl ester group, boronic acid diethyl ester group, boronic acid dipropyl ester group, boronic acid diisopropyl ester group, and boronic acid. Dibutyl ester group, boronic acid dihexyl ester group, boronic acid dicyclohexyl group, boronic acid ethylene glycol ester group, boronic acid propylene glycol ester group (boronic acid 1,2-propanediol ester group, boronic acid 1,3-propanediol ester group ),
Boronic acid ester groups such as trimethylene glycol ester boronic acid group, neopentyl glycol ester boronic acid group, catechol ester boronic acid group, glycerin ester boronic acid group, trimethylolethane ester boronic acid group; boronic acid anhydride group; boronic acid group And alkaline earth metal bases of boronic acid.
In the present invention, the borinic acid group is represented by the following chemical formula 5.

[0016]

[Chemical 5]

The boron-containing group which can be converted to a borinic acid group in the presence of water (hereinafter simply referred to as a boron-containing group) is hydrolyzed in the presence of water and is represented by the chemical formula 5 above. Any boron-containing group that can be converted into an acid group may be used, and as a representative example, a borinic acid ester group represented by the following chemical formula 6, a borinic acid anhydride group represented by the following chemical formula 7, and a boline represented by the following chemical formula 8 are represented. Acid base is mentioned.

[0018]

[Chemical 6]

[0019]

[Chemical 7]

[0020]

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{In the formula, X has the same meaning as X in the above Chemical formula 2, Z is an aliphatic hydrocarbon group similar to X in the above Chemical formula 2,
It represents an alicyclic hydrocarbon group, an aromatic hydrocarbon group, an amino group or an amide group. Further, X and Z may be bonded. Also R
¹ , R ² and R ³ have the same meanings as R ¹ , R ² and R ³ in the above Chemical Formula 4, and M has the same meaning as M in the above Chemical Formula 4. } As specific examples of the borinic acid ester group represented by the above Chemical formulas 6 to 8, X, Z, R ¹ , R ² and R ³ are methyl groups, ethyl groups, propyl groups, butyl groups and 1-methylpropyl groups. , A pentyl group, a hexyl group, a phenyl group, and other lower hydrocarbon groups. Typical examples are methylborinic acid group, methylborinic acid methyl ester group, ethylborinic acid methyl ester group, methylborinic acid ethyl ester group, butylborinic acid methyl ester group, 3-methyl-2.
A butylborinic acid methyl ester group is mentioned. Among the above functional groups, a boronic acid ester group such as a boronic acid ethylene glycol ester group is particularly preferable from the viewpoint of compatibility with PVA (A). The boron-containing group that can be converted to a boronic acid group or a borinic acid group in the presence of water is
Polymer (B) in water or a mixed liquid of water and an organic solvent (toluene, xylene, acetone, etc.), reaction time 1
It means a group which can be converted to a boronic acid group or a borinic acid group when hydrolyzed under the conditions of a reaction temperature of room temperature to 150 ° C. for 0 minutes to 2 hours.

The polymer (B) of the present invention has a functional group selected from the group consisting of a boronic acid group, a borinic acid group and a boronic acid group or a boron-containing group which can be converted into a boric acid group in the presence of water. The structure is not particularly limited as long as it is a polymer having an end, and it is an olefin polymer, an acrylic ester polymer, a methacrylic ester polymer, an aromatic vinyl polymer, an acrylamide polymer, a methacrylamide polymer. Examples thereof include polymers, N-vinylamide-based polymers, oxyalkylene-based polymers, vinyl ester-based polymers, vinyl cyanide-based polymers, vinyl halide-based polymers, vinyl ether-based polymers and diene-based polymers. Examples of monomers constituting these polymers include ethylene, propylene, 1-butene, isobutene, 3-methylpentene, 1
Α-olefins such as hexene and 1-octene; acrylic acid and salts thereof, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, n-dodecyl acrylate, hydroxyethyl acrylate, acrylic acid Acrylic acids such as hydroxypropyl, hydroxybutyl acrylate, and monoglycerin acrylate; methacrylic acid and its salts, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, n-dodecyl methacrylate, hydroxy methacrylate Methacrylic acids such as ethyl, hydroxypropyl methacrylate, monoglycerin methacrylate; aromatic vinyls such as styrene, α-methylstyrene, t-butylstyrene, vinylnaphthalene; acrylamide, N-iso N such as propylacrylamide
-Alkyl acrylamides, N, N-dimethyl acrylamide, acrylamides such as 2-acrylamidopropanesulfonic acid or its salts, acrylamidopropyldimethylamine or its acid salts or its quaternary salts; -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 acetate, vinyl formate, and vinyl acetate. Vinyl esters such as vinyl pionate, vinyl pivalate, vinyl versatate, and vinyl 2-ethylhexanoate; vinyl cyanides such as acrylonitrile and methacrylonitrile; vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride. Halogenated vinyls such as; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, methoxyethyl vinyl ether, and dienes such as butadiene, isoprene and chloroprene. To be The molecular weight of the polymer (B) of the present invention is not particularly limited, but is preferably 50 to 100,000, more preferably 100 to 50,000. The value converted to the melt index (MI) (190 ° C., 2160 g load) is preferably 0.01 to 1000 g / 10 minutes, more preferably 0.1 to 100 g / 10 minutes.

Next, a typical method for producing the polymer (B) having at least one functional group selected from the group consisting of a boronic acid group, a borinic acid group and a boron-containing group used in the present invention will be described. First production method: a polymer having a boronic acid group, a borinic acid group or a boron-containing group at one end is prepared by reacting a polymer having a double bond at one end with a borane complex and a boric acid trialkyl ester. can get. To introduce a functional group such as a boronic acid group into a polymer, a polymer having a double bond, a borane complex, a boric acid trialkyl ester, and a solvent of these three components are heated and reacted under stirring in a nitrogen atmosphere. Done by. As the borane complex, borane-tetrahydrofuran complex, borane-dimethyl sulfide complex, borane-pyridine complex, borane-trimethylamine complex, borane-triethylamine complex and the like are preferable. The amount of the borane complex charged is preferably in the range of 1/3 equivalent to 10 equivalents with respect to the double bond of the polymer. As the boric acid trialkyl ester, boric acid lower alkyl ester such as trimethyl borate, triethyl borate, tripropyl borate, and tributyl borate is preferable. The amount of the trialkyl borate ester charged is preferably in the range of 1 to 100 equivalents with respect to the double bond of the polymer.
The reaction temperature is room temperature to 300 ° C, preferably 100 to 250
The reaction is carried out at a temperature of 1 ° C. for 1 minute to 10 hours, preferably 5 minutes to 5 hours. The types of boronic acid groups or boron-containing groups can be easily interconverted in the presence of water or alcohol. For example, boronic acid dimethyl ester becomes boronic acid by reacting with water, and boronic acid becomes ethylene glycol ester by reacting with ethylene glycol.

Second production method: A polymer having at least one functional group selected from a boronic acid group, a borinic acid group and a boron-containing group at one end is a thiol having a boronic acid group, a borinic acid group or a boron-containing group. It is obtained by radically polymerizing a radically polymerizable monomer in the presence of The thiol having a boronic acid group or a boron-containing group as a raw material can be obtained by reacting a thiol having a double bond with diborane or a borane complex in a nitrogen atmosphere, and then adding an alcohol or water. A thiol having a borinic acid group or a boron-containing group can be obtained by reacting a thiol having a double bond with a diborane or borane complex and an olefin in a nitrogen atmosphere, and then adding an alcohol or water. Examples of the thiol having a double bond include 2-propene-1-thiol, 2-methyl-2-propene-1-thiol, 3-butene-1-thiol, 4-pentene-1-thiol, and the like. Of these, 2-propene-1-thiol and 2-methyl-2-propen-1-thiol are preferred.
As the borane complex, those similar to the above are used, and among them, the borane-tetrahydrofuran complex is particularly preferable. The addition amount of diborane or borane complex is preferably approximately equivalent 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, decalin and the like. Of these, THF is preferable. As alcohols added after the reaction, lower alcohols such as methanol and ethanol are preferable, and methanol is particularly preferable. The olefins added when producing a thiol having a borinic acid group are not particularly limited, but ethylene, propylene, 1-
Butene, 2-butene, 1-pentene, 2-pentene, 2
-Methyl-1-butene, 2-methyl-2-butene, 1-
Lower olefins such as hexene and cyclohexene are preferred. Radical polymerization in the presence of a thiol having a functional group selected from a boronic acid group, a borinic acid group and a boron-containing group thus obtained can be carried out by a usual method.
As 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 a functional group is monomer 1
The amount of thiol added is preferably about 0.001 to 1 mmol per g, and the addition method of the thiol is not particularly limited. However, when a monomer such as vinyl acetate or styrene that easily causes chain transfer is used, the thiol is added during the polymerization. Is preferably fed continuously, and when a substance such as methyl methacrylate that is difficult to chain transfer is used, it is preferable to add a thiol from the beginning.

The resin composition of the present invention comprises PVA (A) and a polymer (B) having at one end a functional group selected from a boronic acid group, a borinic acid group and a boron-containing group, and comprises a component (A). The blending ratio by weight of the component (B) is 99: 1 to 1: 1.
It is selected from the range of 99, more preferably 95: 5 to 5:99.

As a method of blending each of these components, a known method such as a melt blending method using a single-screw or twin-screw extruder can be adopted. Further, in the case of this blending, other additives such as antioxidants, ultraviolet absorbers, lubricants, plasticizers, etc. within the range where the effects of the present invention are not impaired.
Antistatic agents, colorants and the like can be added.

The molding method of the resin molded product of the present invention is not particularly limited as long as it is a method of hot-melt molding a blend of the component (A) and the component (B). Examples thereof include extrusion molding method, injection molding method, inflation molding method, press molding method and blow molding method. By these molding methods, arbitrary molded products such as films, sheets, tubes and bottles can be obtained. The melt molding temperature is 150 to 250
C. is preferable, and 170 to 230.degree. C. is more preferable. The molded product obtained by the present invention is excellent in compatibility, transparency and mechanical properties, and therefore useful for various applications.

[0028]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In the following synthesis examples and examples, unless otherwise specified, the ratio means a weight ratio,
"%" Means "% by weight". The amount of boronic acid groups in the polymer (B) was quantified by 270 MHz- ¹ H-NMR. ^As the solvent for polyethylene and polypropylene at the time of ¹ H-NMR measurement, a mixed solution having a ratio of heavy paraxylene / deuterochloroform = 8/2 was used, and deuterated chloroform was used as a solvent for the other polymers.

The kneading conditions and the physical property measuring conditions are shown below. (Kneading conditions) Machine used: Labo Plastomill (manufactured by Toyo Seiki) Rotation speed: 80 rotations / minute Kneading time: 10 minutes (surface electrical resistance) The obtained film was 20 ° C and humidity 65
% For 1 week, and the surface electric resistance thereof was measured with an electric resistance measuring device (manufactured by HEWLETT PACKARD).

Synthesis Example 1 Synthesis of polyethylene glycol having a boronic acid group at one end: A separable flask was charged with 50 g of polyethylene glycol monoallyl ether having an average molecular weight of 350,
Nitrogen substitution was performed. At 0 ° C., 11.44 g of borane-dimethyl sulfide complex was added dropwise over 30 minutes, reacted for 40 minutes, then heated to 40 ° C., and reacted for 3 hours. 0 ° C
After cooling to 20 ml, 20 ml of methanol was added dropwise over 30 minutes. Methanol and dimethyl sulfide were distilled off, and 200 g of toluene was added. After filtering off the precipitated solid content, toluene was distilled off to obtain polyethylene glycol (PEG) having a boronic acid group of 2.6 meq / g at one end.

Synthesis Example 2 Synthesis of ethylene oxide-propylene oxide copolymer having a boronic acid group at one end: an ethylene oxide (EO) -propylene oxide (PO) copolymer having an allyl group at one end and having an average molecular weight of 1600 in a separable flask. 150 g of a polymer (molar ratio EO / PO = 75/25) and 200 g of toluene were charged and nitrogen substitution was carried out. At 0 ° C., 8.01 g of borane-dimethyl sulfide complex was added dropwise over 30 minutes, and after reacting for 40 minutes, the temperature was raised to 40 ° C. and 3
The reaction was carried out over time. Cooled to 0 ° C, methanol 10 ml
Was added dropwise over 30 minutes. After distilling off methanol and dimethyl sulfide and filtering off the precipitated solid content,
By distilling off toluene, an ethylene oxide-propylene oxide copolymer [P (EO / PO)] having a boronic acid group at one end of 0.56 meq / g was obtained.

Synthesis Example 3 Synthesis of 3-mercaptopropylboronic acid ethylene glycol ester (MPBE): sodium borohydride (NaBH ⁴ ) 1 in a flask equipped with a condenser and a dropping funnel.
Nitrogen substitution was carried out by charging 9.26 g. THF5 which was dried with benzophenone and sodium metal and distilled
After charging 00 ml and cooling to 0 ° C. in an ice bath, 99.95 g of boron trifluoride-diethyl ether complex was added dropwise over 30 minutes while stirring. 0 after 2 hours
45.61 g of 2-propene-1-thiol was added dropwise at 30 ° C over 30 minutes. After stirring for 40 minutes, the temperature was raised to 60 ° C. and stirring was further performed for 3 hours. After cooling to 0 ° C., 100 ml of methanol was added dropwise over 40 minutes. After the reaction solution was filtered to remove solids, the solvent was distilled off, 38 g of ethylene glycol was added, and the mixture was extracted with methylene chloride-water to remove excess ethylene glycol, dried over magnesium sulfate, and distilled under reduced pressure to give 3-mercaptoborone. 4: 1 mixture of acid ethylene glycol ester and 2-mercapto-1-methylethylboronic acid ethylene glycol ester 4
6.7 g were obtained (boiling point 70 ° C. at 4 mmHg).

Synthesis Example 4 Synthesis of low density polyethylene having a double bond at one end:
A separable flask was charged with 200 g of low-density polyethylene having an MI of 0.35 g / 10 min, and the bath temperature was 260 under vacuum.
After heating at ℃ for 30 minutes, further raise the bath temperature to 340 ℃ 2
Double heating of 0.06 meq
/ G, MI 90 g / 10 min of low density polyethylene having a double bond at one end was obtained.

Synthesis Example 5 Synthesis of low-density polyethylene having a boronic acid group at one end: 30 g of low-density polyethylene obtained in Synthesis Example 4, 300 mg of borane-pyridine complex, tributyl borate 2 in a separable flask equipped with a condenser. 0.25g, decalin 5
0 g was charged, and after purging with nitrogen, the reaction was carried out at 190 ° C. for 3 hours. After cooling to room temperature, the resulting gel-like polyethylene was thoroughly washed with a mixed solvent of methanol-acetone 1: 1 and then dried to obtain a boronic acid group at one end of 0.035 m.
A low density polyethylene having MI of 2 g / 10 min with eq / g was obtained.

Synthesis Example 6 Synthesis of polypropylene having a double bond at one end: 200 g of polypropylene {MI (230 ° C., load 2160 g) 0.3 g / 10 min} was charged in a separable flask.
After heating under a vacuum at a bath temperature of 250 ° C. for 1 hour, the bath temperature was further raised to 340 ° C. and then heating for 2 hours. After cooling, polypropylene was taken out and pulverized to obtain MI 80 g / m having a double bond of 0.031 meq / g at one end.
A polypropylene of 10 minutes was obtained.

Synthesis Example 7 Synthesis of polypropylene having a boronic acid group at one end: Synthesis Example 6 in a separable flask equipped with a condenser and a stirrer
100 g of polypropylene obtained in step 2, 200 g of decalin
Was charged, the atmosphere was replaced with nitrogen, the temperature was raised to 180 ° C., and nitrogen was further introduced into the reactor for 30 minutes. To this was added 5.5 g of trimethyl borate and 7 of borane-trimethylamine complex.
After adding 60 milligrams (mg) and performing reaction at 180 degreeC for 4 hours, it cooled to room temperature. The gel polypropylene obtained was thoroughly washed with a 1/1 mixture of methanol and acetone and then dried to obtain polypropylene having a boronic acid group of 0.025 meq / g at one end and MI of 4 g / 10 min. .

Synthesis Example 8 Synthesis of polymethylmethacrylate having a boronic acid ester group at one end: 150 g of methylmethacrylate in a flask equipped with a stirrer and a condenser, the ethylene glycol 3-mercaptopropylboronic acid obtained in Synthesis Example 3 After charging 0.876 g of ester (MPBE) and degassing by blowing nitrogen, the temperature was raised to 80 ° C.,
0.23% of separately prepared azobisisobutyronitrile
After adding 1.5 ml of the toluene solution first, 0.5 ml was added every 30 minutes. After 5 hours, it was cooled and the polymerization was stopped. The polymerization rate at this time was 47%. The obtained polymethylmethacrylate was reprecipitated with methanol and then dried to obtain polymethylmethacrylate having an average molecular weight of 25,000 and having a boronic acid ethylene glycol group at one end of 0.03 meq / g.

Synthesis Example 9 Synthesis of polystyrene having a boronic acid ester group at one end: 500 g of styrene in a flask equipped with a stirrer and a reflux condenser and the 3-mercaptopropylboronic acid ethylene glycol ester obtained in Synthesis Example 3 ( MPB
E) 0.0765 g was charged and deaeration under reduced pressure was performed. 1
After heating to 20 ° C., a styrene solution containing 0.394% MPBE and 0.069% azobiscyclohexanecarbonitrile was first fed at a rate of 7.2 ml and then at a rate of 0.5 ml / min, and after 210 minutes, reaction and feed were performed. Stopped. The polymerization rate at this time was 45%. Purification by reprecipitation of this polystyrene with methanol,
By further drying, the average molecular weight is 68,000.
A polystyrene having 0.013 meq / g of boronic acid ethylene glycol ester group at one end was obtained.

Example 1 A resin composition consisting of 20 parts of PEG having a boronic acid group at one end and 80 parts of PVA (polymerization degree: 500, saponification degree: 73 mol%) of Synthesis Example 1 was melted at 180 ° C. for 10 minutes. After kneading, hot pressing was performed at 180 ° C. to obtain a film having a thickness of 50 μm. This film is 3 cm wide,
Cut it to a length of 3 cm and embed it in diatomaceous earth for 50
The film was allowed to stand in a constant temperature bath at 30 ° C. for 30 days to examine the change in PEG content in the film. When the PEG content was quantified by NMR, the initial value of 20.5% was 19.8% even after 30 days, and there was almost no transfer of PEG to diatomaceous earth.

Comparative Example 1 Unmodified PE was used instead of PEG having a boronic acid group at one end.
A film was prepared in the same manner as in Example 1 except that G (average molecular weight 350) was used, and the film was embedded in diatomaceous earth and a standing test was performed. The PEG content decreased from the initial 20.2% to 4.1%, and most of the PEG was transferred to diatomaceous earth. As is clear from Example 1 and Comparative Example 1 described above, the composition of the present invention is useful as a PVA-based film material having no plasticizer migration.

Example 2 Ethylene oxide having a boronic acid group at one end in Synthesis Example 2 in place of 20 parts of PGE having a boronic acid group at one end
A film was prepared in the same manner as in Example 1 except that 20 parts of propylene oxide copolymer P (EO / PO) was used, and the film was embedded in diatomaceous earth and a standing test was performed. P (EO
/ PO) content is 19.9% at the initial value, but remains 1 even after 30 days
It was 9.6%, and there was almost no transfer to diatomaceous earth.

Comparative Example 2 Example except that P (EO / PO) having an allyl group at one end (average molecular weight 1600) was used instead of 20 parts of P (EO / PO) having a boronic acid group at one end. A film was prepared in the same manner as in 2, and embedded in diatomaceous earth to carry out a standing test. Initial P (EO / PO) content is 20.1%
To 9.4%, about half of P (EO / PO) was transferred to diatomaceous earth. From the results of Example 2 and Comparative Example 2 described above, by using the resin composition of the present invention, a PVA-based molded product without migration of the plasticizer can be obtained.

Example 3 10 parts of low density polyethylene having a boronic acid group at one end of Synthesis Example 5 and unmodified low density polyethylene (190 ° C., 2
80 parts by weight (MI 3 g / 10 min) and PVA (polymerization degree 500, saponification degree 73 mol%) 10 under the measurement conditions of 160 g
2 parts of the composition is melt-kneaded under the following conditions:
A film having a thickness of 50 μm was obtained by hot pressing at 00 ° C. The film has good transparency and is 20 ° C.
The surface resistivity measured after humidity conditioning for 1 week under x65% RH is
It was 3.0 × 10 ¹¹ Ω / □.

Comparative Example 3 10 parts of low-density polyethylene having a boronic acid group at one end of Example 3 was replaced with unmodified low-density polyethylene (MI 3 g / 1
A film was prepared in the same manner as in Example 3 except that 10 parts of 0 minutes, 190 ° C. and 2160 g) were used. The film had poor transparency and was cloudy, and the surface resistivity measured after humidity conditioning at 20 ° C. × 65% RH for 1 week was 2.8 × 10 ¹² Ω / □.
Met.

Example 4 10 parts of polypropylene having a boronic acid group at one end of Synthesis Example 7 and unmodified polypropylene (MI 4 g / 10 min, 1
A film was prepared in the same manner as in Example 3 using a resin composition consisting of 80 parts at 90 ° C. and a load of 2160 g) and 10 parts PVA (degree of polymerization: 500, 3 mol% of saponification degree).
The film has good transparency, 20 ° C, 65% RH
The surface resistivity measured after temperature control for 1 week was 8.5 × 10 ¹³
It was Ω / □.

Comparative Example 4 10 parts of polypropylene having a boronic acid group at one end of Example 4 was replaced with unmodified polypropylene (MI 4 g / 10 min,
Example 4 except that 10 parts were used.
A film was prepared in the same manner as in. The film had poor transparency and became cloudy, and the surface resistivity measured after conditioning for 1 week at 20 ° C. and 65% RH was 10 ¹⁴ or more Ω / □.

Example 5 10 parts of polymethylmethacrylate having a boronic acid group at one end of Synthesis Example 8, 80 parts of unmodified polymethylmethacrylate (trade name: Parapet G, manufactured by Kuraray Co., Ltd.) and 6 mol of allyl acetate modified PVA (degree of polymerization 540,
A resin composition consisting of 10 parts of a saponification degree of 99.1 mol% was melt-kneaded at 220 ° C. for 10 minutes and then hot pressed at 230 ° C. to obtain a film having a thickness of 50 μm. The film has good transparency and is 20 ° C. × 65%
The surface resistivity measured after conditioned for 1 week under RH was 6.0 ×.
It was 10 ¹¹ Ω / □.

Comparative Example 5 2-mercaptoethanol 0.464 g was used in place of 0.867 g of 3-mercaptopropylboronic acid ethylene glycol ester in Synthesis Example 8 to obtain 2 at one end.
A film having a thickness of 50 μm was prepared in the same manner as in Example 5, except that polymethylmethacrylate having a hydroxyethylthiyl group (average molecular weight 25,000) was used. The film has poor transparency and becomes cloudy, and the temperature is 20 ° C ×
The surface resistivity measured after conditioning for 1 week under 65% RH is
It was 7.8 × 10 ¹³ Ω / □.

Example 6 Polystyrene 1 having a boronic acid group at one end of Synthesis Example 9
0 parts, unmodified polystyrene (trade name: Staroylon 66
6, Asahi Kasei Kogyo Co., Ltd. 80 parts and ethyl vinyl ether 5 mol modified PVA (polymerization degree 450, saponification degree 9)
Using a resin composition consisting of 10 parts,
After melt-kneading at 90 ° C. for 10 minutes, hot pressing was performed at 210 ° C. to obtain a film having a thickness of 50 μm. The film has good transparency and has a transparency of 1 at 20 ° C. and 65% RH.
The surface resistivity measured after weekly humidity control is 2.1 × 10 ¹¹ Ω /
It was □.

Comparative Example 6 In place of 0.0765 g of 3-mercaptopropylboronic acid ethylene glycol ester in Synthetic Example 9, 0.464 g of 2-mercaptoethanol was synthesized to have a 2-hydroxyethylthiyl group at one end. A film having a thickness of 50 μm was prepared in the same manner as in Example 6 except that polystyrene (average molecular weight: 65,000) was used. The film has poor transparency and becomes cloudy, and the temperature is 20 ° C x 65% RH.
The surface resistivity measured after the humidity control for 1 week was 5.8 × 10.
It was ¹² Ω / □. Examples 3 to 6 and Comparative Example 3 described above
From the results of ~ 6, by using the resin composition of the present invention, a molded article having good transparency and excellent antistatic properties can be obtained.

[0051]

EFFECTS OF THE INVENTION According to the method for producing a molded article of the present invention, when a heat treatment is performed, the functional group at one end of the polymer (B) and the hydroxyl group of PVA (A) are bonded by a transesterification reaction. In addition, it is estimated that the transparency of the molded product is improved. It should be noted that in the present invention, the term "excellent transparency of the molded article" means that it is superior to the transparency of the resin composition of PVA and an unmodified polymer containing no boronic acid group or borinic acid group. Means The molded product obtained by the production method of the present invention has a component (A) and a component (B).
Shows a very wide range of physical properties depending on the combination of the above, particularly the kind of the polymer (B). An example is shown below. Polymer (B)
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. It is useful for molded articles such as water-soluble films, sheets and bottles that 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 processing agent that gives the paper a firmness. When the polymer (B) 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 article such as a film or a 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 molded article having hygroscopicity and water absorption.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiaki Sato 1621 Sakazu, Kurashiki City, Okayama Prefecture, Kuraray Co., Ltd. (72) Inventor Hitoshi Maruyama 1621, Satsuki, Kurashiki City, Okayama Prefecture, Kuraray Co., Ltd. (72) Inventor Masaaki Kinugawa 1621 Satsuki, Kurashiki City, Okayama Prefecture Kuraray Co., Ltd.

Claims (2)

[Claims] 1. A polyvinyl alcohol polymer (A)
And a polymer (B) having a functional group selected from the group consisting of a boronic acid group, a borinic acid group, and a boron-containing group convertible into a boronic acid group or a borinic acid group in the presence of water at one end.
A method for producing a molded article, which comprises subjecting a resin composition comprising the composition to hot melt molding. 2. The method for producing a molded article according to claim 1, wherein the weight mixing ratio of the component (A) and the component (B) is 1:99 to 99: 1.