JP2882648B2 - Manufacturing method of thermoplastic water-soluble resin - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a thermoplastic water-soluble resin by adding a polyoxyalkylene glycol monoether to a copolymer of isobutylene and maleic anhydride.

[Conventional technology]

Conventionally, a method for producing a maleic anhydride copolymer by copolymerizing maleic anhydride with an α-olefin such as ethylene, isobutylene, diisobutylene, or a vinyl compound such as styrene or methyl vinyl ether has been known. Maleic anhydride copolymer is mainly used as a water-soluble binder. However, these copolymers have high softening points, poor hot-melt moldability, and are hard and brittle, and their applications have been limited.

[Problems to be solved by the invention]

In view of the above situation, the present invention is to modify the copolymer of isobutylene and maleic anhydride by adding a polyoxyalkylene glycol monoether to the copolymer.
An object of the present invention is to provide a method for producing a thermoplastic water-soluble resin which can be melt-molded and has excellent film properties.

[Means for solving the problem]

According to the present invention, the object is to provide a copolymer of isobutylene and maleic anhydride with a general formula (I) RO (AO) _n H (I) wherein R is an alkyl group having 1 to 10 carbon atoms; Is a vic-alkylene group having 2 to 4 carbon atoms which may be substituted by a phenyl group, and A in each () may be the same or different. A
And may be connected in a block or may be connected at random via O, and n is an integer of 1 or more). The problem is solved by a method for producing a thermoplastic water-soluble resin.

 Hereinafter, the present invention will be described in detail.

The copolymer of isobutylene and maleic anhydride used in the present invention means a copolymer obtained by a chain reaction of isobutylene and maleic anhydride through a carbon-carbon double bond.

Maleic anhydride used includes maleic acid, monoalkyl maleate, dialkyl maleate,
Some maleic acid derivatives such as chlormailenic acid and citraconic acid may be contained. The content of these derivatives is not particularly limited, but is usually up to 80% (w / w).

In the present invention, a thermoplastic water-soluble resin having a high heat distortion temperature, a high thermal decomposition temperature and excellent strength is derived from using a copolymer of isobutylene and maleic anhydride as a raw material maleic anhydride copolymer. Can be obtained.

Copolymers of isobutylene and maleic anhydride include vinyl compounds such as vinyl ether, vinyl ester, vinyl halide, allyl ether, allyl alcohol, allyl ester, acrylonitrile, acrylic ester, methacrylic ester, acrylic amide and methacrylamide. , Maleimide, N-substituted maleimide, etc., may be copolymerized.

The copolymer molar ratio of the copolymer of isobutylene and maleic anhydride used in the present invention is 1 mol in total with respect to 1 mol of the copolymer of maleic anhydride and the maleic anhydride when the maleic anhydride is contained. Suitably, it is ５5 mol.

The molecular weight of the copolymer of isobutylene and maleic anhydride is not particularly limited, but the thermoforming processability of the thermoplastic water-soluble resin obtained in the present invention, the strength of the molded product, physical properties such as flexibility are appropriate. 1,000-1,000,0 to be in the range
00 is preferred.

The copolymer of isobutylene and maleic anhydride used in the present invention is partially known, and the above-mentioned isobutylene (including the above-mentioned vinyl compound in some cases) can be obtained by a known method (for example, JP-B-53-38095). And maleic anhydride are copolymerized using a radical catalyst. In brief, the radical polymerization catalyst used in such copolymerization includes organic peroxides such as cumene hydroperoxide, t-butyl hydroperoxide, and benzoyl peroxide; α, α'-
Examples include azo compounds such as azobisisobutyronitrile, α, α′-azo-α-ethylbutyronitrile, and α, α′-azo-α-methylvaleronitrile. Polymerization is carried out by a solution polymerization or precipitation polymerization method using a solvent that does not inhibit radical polymerization, for example, acetone, methyl ethyl ketone, benzene, toluene, ethyl acetate, isopropyl acetate, dioxane, tetrahydrofuran, chloroform and the like. It is also possible to carry out by bulk polymerization without using a solvent. Although the polymerization temperature is not particularly limited, it is usually in the range of 0 to 200 ° C., and the polymerization time is usually 1 to 50.
Time range. In the case of precipitation polymerization, the resulting maleic anhydride copolymer is separated from the polymerization-terminated liquid by filtering and removing the precipitated polymer, followed by drying. In the case of solution polymerization, the solvent is driven off and dried.

The polyoxyalkylene glycol monoether of the general formula (I), which is another raw material of the present invention, has 1 to 10 carbon atoms.
May be substituted with a phenyl group in the presence of a basic catalyst such as potassium hydroxide, sodium hydroxide, pyridine, picoline, 2-methylimidazole or an acid catalyst such as boron trifluoride or tin tetrachloride. 2 carbon atoms
Obtained by subjecting 10 vic-alkylene oxides to an addition reaction. Further, an alkanol having 1 to 10 carbon atoms and Li, K,
The polyoxyalkylene glycol monoether of the general formula (I) can also be obtained by polymerizing a vic-alkylene oxide having 2 to 10 carbon atoms using an alcoholate with Na, Mg, Zn, Al, Sn or Fe as an initiator. .

Examples of the alkanol having 1 to 10 carbon atoms used in the present invention include methanol, ethanol, propanol, butanol, heptanol, nonanol, decanol, and the like, and further, a phenyl group may have 2 to 10 carbon atoms which may be substituted. Examples of the vic-alkylene oxide include ethylene oxide, propylene oxide, 1,2-epoxybutane, 1,2-epoxypentane, and styrene oxide.

The addition reaction of the alkylene oxide to the alkanol proceeds almost stoichiometrically, and a polyoxyalkylene glycol monoether having an average molar number of the added alkylene oxide to the alkanol is obtained.
There is no strict upper limit for n in the above general formula (I), but if it is too large, the addition reaction of the alkylene oxide takes time, and the obtained polyoxyalkylene glycol monoether, isobutylene and maleic anhydride have the same properties. Since the esterification reaction with the copolymer is also slow, about 100
It is preferably an integer of the following, more preferably an integer of about 50 or less.

The amount of the catalyst used is 0.1 to 5% by weight based on the alkanol.
Is appropriate. The solvent is usually unnecessary, but may be diluted with a solvent having no active hydrogen, for example, acetone, tetrahydrofuran, dioxane or the like.

The reaction is usually suitably carried out at 30 to 150 ° C. for 1 to 30 hours.

After the reaction, when no unreacted alkylene oxide remains in the reaction solution, the reaction solution containing polyoxyalkylene glycol monoether can be used as it is for the esterification reaction of isobutylene and a copolymer of maleic anhydride. If unreacted alkylene oxide remains in the reaction solution, it is preferable to remove the alkylene oxide by distillation and then use it for the esterification reaction of a copolymer of isobutylene and maleic anhydride.

The thermoplastic water-soluble resin of the present invention is obtained by adding a polyoxyalkylene glycol monoether of the general formula (I) to a copolymer of isobutylene and maleic anhydride by an esterification reaction. As a condition for the esterification, a method in which a copolymer of isobutylene and maleic anhydride and an esterification catalyst are charged into a polyoxyalkylene glycol monoether diluted with an organic solvent as necessary, and the mixture is heated and stirred is preferable.

 The above esterification is a half esterification.

As the esterification catalyst, an acid catalyst such as formic acid or p-toluenesulfonic acid or a basic catalyst such as a tertiary amine, pyridine, or an imidazole compound is suitable. The amount of esterification catalyst used is based on the maleic anhydride copolymer.
0.1-3% by weight for acid catalyst, 0.1-5% for basic catalyst
% By weight is appropriate. As a solvent to be used, a solvent that dissolves both the starting compound and the resulting compound, for example, dimethylformamide, acetone, tetrahydrofuran and the like are suitable.

If the degree of esterification is too small, the resulting thermoplastic water-soluble resin will have insufficient thermoplasticity, so that the maleic anhydride group 5 in the copolymer of isobutylene and maleic anhydride will be insufficient.
% Or more, especially 8% or more is suitably esterified.

The reaction temperature varies depending on the type of the copolymer of isobutylene and maleic anhydride and the type of polyoxyalkylene glycol monoether used, but is generally preferably from 50 to 200 ° C. The reaction time is suitably from 1 to 30 hours.

After completion of the esterification reaction, unreacted polyoxyalkylene glycol monoether and a solvent used are removed by distillation to obtain a thermoplastic water-soluble resin as a residue.

According to the present invention, a thermoplastic water-soluble resin having various physical properties (softening point, melt viscosity, film strength, degree of water solubility) can be obtained depending on the type of polyoxyalkylene glycol monoether, the difference in esterification ratio, and the like. However, generally, it can be melt-molded and has excellent film properties. Such a thermoplastic water-soluble resin can be applied to a hot melt binder, an aqueous binder, an absorbent composition, a polymer alloy, a dispersant, an adhesive, or formed into a thread, film, or fibrous material for use. .

Although it is generally difficult to structurally represent the thermoplastic water-soluble resin obtained by the method of the present invention, And a structural unit (maleic anhydride group) represented by —CH ₂ —C (C
H ₃ ) The former structural unit 1 comprising a structural unit represented by _2-
More than 5% of the maleic anhydride groups of the copolymer of isobutylene and maleic anhydride in the latter 1 to 5 mole ratio with respect to the mole are half-esterified with the polyoxyalkylene glycol monoether of the general formula (I). It can be expressed like a copolymer obtained.

〔Example〕

Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.

Example 1 An autoclave was charged with 64 g of methanol and 0.32 g of 2-methylimidazole. After purging with nitrogen, 528 g of ethylene oxide was gradually injected at 60 to 80 ° C. to carry out an addition reaction for 10 hours. After completion of the reaction, the remaining unreacted ethylene oxide was distilled off, and the average addition mole number of ethylene oxide was 6 (according to gel permeation chromatography (GPC) analysis, n = 4 to 8 with n = 6 as the center). Polyoxyethylene glycol monomethyl ether).

Next, 17.8 g of the obtained polyoxyethylene glycol monomethyl ether, an isobutylene-maleic anhydride copolymer having a weight average molecular weight of 50,000 (Isoban 04, manufactured by Kuraray Co., Ltd.) (copolymer composition molar ratio: isobutylene: maleic anhydride = 1: 1) 30.8 g, 2-methylimidazole 0.50 g, and dimethylformamide (DMF) 100 g were charged into a three-necked flask equipped with a reflux condenser, and stirred and heated at 80 to 90 ° C. for 5 hours under a stream of N ₂ gas. To carry out an esterification reaction.

The unreacted polyoxyethylene glycol monomethyl ether in the reaction completed solution was quantified by GPC using PPG (polypropylene glycol) as an internal standard substance.
The average conversion of polyoxyethylene glycol monoether was 50%.

DMF and unreacted polyoxyethylene glycol monoether were distilled off by keeping the reaction completed solution at 120 ° C. under reduced pressure, and 39.5 g of a partially esterified product of isobutylene-maleic anhydride copolymer with polyoxyethylene glycol monomethyl ether was distilled off. I got

The structure of the obtained partially esterified product was confirmed by elemental analysis, acid value measurement and infrared absorption spectrum measurement.

Elemental analysis C: 59.8% (theoretical 60.2%) H: 7.3% (theoretical 7.2%) Acid value 519 mg KOH / g (theoretical 523 mg KOH / g) That is, the esterification rate is 14.9%.

Infrared absorption spectrum 3550 cm ^-1 νOH (carboxylic acid) 1750 cm ^-1 νC = O (ester, carboxylic acid) 1860,1800 cm ^-1 νC = O (maleic anhydride group) 1120 cm ^-1 νC-O (ether bond) The obtained partially esterified product was heat-pressed at 150 ° C. × 50 kg / cm ² G for 3 minutes to prepare a transparent sheet having a thickness of 1 mm. When the softening point of this sheet was measured, it was 120
° C and a tensile test (tensile speed 50 mm / min) was performed with an Instron universal testing machine.
/ cm ² G and elongation at break were 30%.

Further, 10 g of the obtained partially esterified product, 25% NH ₃ water 6.34
g and 50 g of water were placed in a three-necked flask equipped with a reflux condenser and heated and stirred at 50 to 60 ° C. for 30 minutes to obtain a transparent aqueous solution.

The isobutylene-maleic anhydride copolymer used as a raw material did not have thermoplasticity and could not be molded by heat press. The same was true for the starting maleic anhydride copolymer used in the following examples.

Example 2 1 An autoclave was charged with 46.1 g of methanol and 0.5 g of 2-methylimidazole, and after purging with nitrogen, 440 g of ethylene oxide was gradually injected at 70 to 90 ° C. to carry out an addition reaction for 10 hours. As a result, 9 (a mixture of n = 7 to 12 addition moles centered on n = 10 according to GPC analysis) polyoxyalkylene glycol monoether was obtained.

Next, 29.2 g of the obtained polyoxyethylene glycol monoethyl ether, an isobutylene-maleic anhydride copolymer having a weight average molecular weight of 150,000 (Isovan 10, manufactured by Kuraray Co., Ltd.) (copolymer composition molar ratio: isobutylene: maleic anhydride) = 1: 1) 30.8 g, 2-methylimidazole 0.50 g, and D
Charge 150 g of MF into a three-necked flask equipped with a reflux condenser,
The esterification reaction was carried out by stirring and heating at 100 to 120 ° C. for 6 hours under N ₂ .

From the amount of unreacted polyoxyethylene glycol monoethyl ether in the reaction completed solution, the average conversion of polyoxyethylene glycol monoethyl ether was 30%.

The reaction-terminated liquid was poured into a large amount of water to precipitate a polymer to remove unreacted polyoxyethylene glycol monoethyl ether and DMF, and dried under reduced pressure at 80 ° C to obtain an isobutylene-maleic anhydride copolymer. 39.0 g of a partially esterified product of the above with polyoxyethylene glycol monoethyl ether (esterification ratio 10%) was obtained.

The obtained partially esterified product was heat-pressed at 150 ° C. × 50 kg / cm ² G for 3 minutes to form a transparent sheet having a thickness of 0.5 mm. The softening point of this sheet was 100 ° C., the breaking strength in a tensile test was 20 kg / cm ² G, and the breaking elongation was 350%.

Further obtained 20 g of partially esterified product, 25% NH ₃ water 5.15
g and 100 g of water were stirred and heated at 50 ° C. for 10 minutes to obtain a transparent aqueous solution.

Example 3 One autoclave was charged with 74.1 g of n-butanol and 0.7 g of 2-methylimidazole.
At 26 ° C., 264 g of ethylene oxide was gradually injected, and an addition reaction was carried out for 15 hours to obtain poloxyethylene glycol monobutyl ether having an average addition mole number of ethylene oxide of 6.

An isobutylene-maleic anhydride-N-phenylmaleimide copolymer (isobutylene: maleic anhydride: N-phenylmaleimide) having 27.1 g of polyoxyethylene glycol monobutyl ether thus obtained and having a weight average molecular weight of 45,000 (by GPC analysis). Copolymer composition molar ratio of == 0.5
2: 0.42: 0.08) 35.2g, was charged with pyridine 1.0g and acetone 100g necked flask equipped with a reflux condenser, N ₂ under 80
The mixture was stirred and heated at 100 ° C. for 4 hours to carry out an esterification reaction.

From the analysis result of the reaction-terminated liquid, the conversion of polyoxyethylene glycol monobutyl ether was 45%.

DMF and unreacted polyoxyethylene glycol monobutyl ether were distilled off by maintaining the reaction-terminated liquid at 120 ° C. under reduced pressure, and isobutylene-maleic anhydride-N-
Partial esterification of phenylmaleimide copolymer with polyoxyethylene glycol monobutyl ether 46.8
g was obtained.

Next, the obtained partially esterified product (esterification rate 20
%) Was heat-pressed at 150 ° C. × 50 kg / cm ² G for 5 minutes to form a sheet having a thickness of 1 mm. The softening point of this sheet is 1
It is 00 ° C and the breaking strength by the tensile test is 60 kg / cm ² G,
The breaking elongation was 50%.

Also, 20 g of the esterified product, 6.2 g of 25% NH ₃ and 50 g of water
After stirring and heating at 8080 ° C. for 30 minutes, a clear aqueous solution was obtained.

The above isobutylene-maleic anhydride-N-phenylmaleimide copolymer was produced as follows: 250 g of ethyl acetate, 110 g of t-butyl alcohol, 29.4 g of maleic anhydride, 9.9 g of N-phenylmaleimide and α,
After placing 0.60 g of α'-azobisisobutyronitrile in an autoclave equipped with a stirrer and purging with nitrogen for 30 minutes with stirring, 22.0 g of isobutylene was added, and the solution in the autoclave was heated to 80 ° C and then heated to 80 ° C. For 6 hours to carry out a polymerization reaction. After completion of the polymerization reaction, the solution in the autoclave was cooled to room temperature and degassed. The contents were taken out of the autoclave, the precipitated polymer was filtered and dried, and a terpolymer of isobutylene / maleic anhydride / N-phenylmaleimide 57.9 was obtained.
g was obtained. The weight average molecular weight and copolymer composition of this terpolymer were as described above.

Comparative Example 1 18.70 g of a polyoxyethylene glycol monomethyl ether having an average addition mole number of ethylene oxide of 6 obtained by the same method as in Example 1 and a styrene-maleic anhydride copolymer having a weight average molecular weight of 6,000 (copolymer composition mole ratio) Ratio = 1: 1 (N
MR analysis)) 42.48 g, 0.40 g of 2-methylimidazole and D
Charge MF120g into a three-necked flask equipped with a reflux condenser,
The esterification reaction was carried out by stirring and heating at 95 to 105 ° C for 6 hours.

From the analysis value of unreacted polyoxyethylene glycol monomethyl ether in the reaction completed solution, the conversion of polyoxyethylene glycol monomethyl ether was 49%.

DMF and unreacted polyoxyethylene glycol monoethyl ether were distilled off by maintaining the reaction-terminated liquid at 120 ° C. under vacuum, and a partially esterified product of ethylene-maleic anhydride copolymer with polyoxyethylene glycol monomethyl ether ( (Esterification ratio: 14.6%) 51.25 g was obtained.

Next, the obtained partially esterified product was heat-pressed at 150 ° C. × 50 kg / cm ² G for 5 minutes to prepare a sheet having a thickness of 1 mm. The softening point of this sheet was 60 ° C. Further, 20 g of the esterified product, 5.0 g of 25% NH ₃ water and 50 g of water were added at 70 to 80 ° C. for 30 g.
After stirring for minutes, a clear aqueous solution was obtained.

Example 4 One autoclave was charged with 48 g of methanol and 1 g of NaOH, and after purging with nitrogen, propylene oxide 522.9 was added at 90 to 100 ° C.
g was gradually charged and an addition reaction was carried out for 15 hours to obtain polyoxypropylene glycol monomethyl ether having an average addition mole number of propylene oxide of 6.

Next, 34.25 g of the obtained polyoxypropylene glycol monomethyl ether, 46.26 g of an isobutylene-maleic anhydride copolymer (Isoban 04) having a weight average molecular weight of 50,000, and 2
0.50 g of -methylimidazole and 150 g of DMF were charged into a three-necked flask equipped with a reflux condenser, and heated with stirring at 90 to 100 ° C for 6 hours to perform an esterification reaction.

From the analysis value of unreacted polyoxypropylene glycol monomethyl ether in the reaction completed solution, the conversion of polyoxypropylene glycol monomethyl ether was 57%.

The DMF and unreacted polyoxypropylene glycol monomethyl ether were distilled off by maintaining the reaction-terminated liquid at 120 ° C. under vacuum, and the isobutylene-maleic anhydride copolymer was partially esterified with polyoxypropylene glycol monomethyl ether (ester). Conversion 17%).

Next, the obtained partially esterified product was treated at 150 ° C. × 50 kg / cm ² G
For 5 minutes to form a sheet having a thickness of 1 mm. The softening point of this sheet was 105 ° C., the breaking strength in a tensile test was 86 kg / cm ² G, and the breaking elongation was 90%. The esterified product 20 g, 25% NH ₃ water 6.0 g, water 50 g
Was heated with stirring at 70 ° C. for 2 hours to obtain a transparent aqueous solution.

Example 5 An autoclave was charged with 163 g of polyoxyethylene glycol monomethyl ether having an average addition mole number of ethylene oxide of 3 and 0.5 g of NaOH.
Polyoxyethylene / polyoxypropylene in which polyoxyethylene groups and polyoxypropylene groups are added in blocks by adding 174 g of propylene oxide gradually at 0 ° C. and performing an addition reaction for 10 hours (average number of moles of propylene oxide added: 3). Glycol monomethyl ether was obtained.

Next, 30.33 g of the obtained monomethyl ether, 46.26 g of an isobutylene-maleic anhydride copolymer having a weight average molecular weight of 50,000 (Isovan 04), and 1.50 g of 2-methylimidazole were charged into a three-necked flask equipped with a reflux condenser. , 90-100 ℃
For 6 hours to carry out an esterification reaction. From the analysis value of unreacted monomethyl ether in the reaction completed solution, the conversion of the monomethyl ether was 43%.

The DMF and unreacted monomethyl ether were distilled off by keeping the reaction completed solution at 120 ° C. under vacuum to obtain a partially esterified product of isobutylene-maleic anhydride copolymer.
Next, the obtained partially esterified product (esterification rate 12.8
%) At 150 ° C x 50 kg / cm ² G for 5 minutes with heat press.
A 1mm sheet was created. The softening point of this sheet was 115 ° C., the breaking strength by a tensile test was 45 kg / cm ² G, and the breaking elongation was 65%. In addition, the esterified product 20 g, 25% N
6.0 g of H ₃ water and 50 g of water were stirred and heated at 70 ° C. for 1 hour.
A clear aqueous solution was obtained.

Example 6 29.6 g of polyoxyethylene glycol monomethyl ether (n = 6) obtained in Example 1 and Isovan-04 15.4
g, 2-methylimidazole (0.60 g) and dimethylformamide (150 g) were charged into a three-necked flask equipped with a reflux condenser, and heated with stirring at 110 to 120 ° C. for 12 hours under a stream of N _{2 to} carry out an esterification reaction. From the analysis value of unreacted polyoxyethylene glycol monomethyl ether in the reaction completed solution, the reaction rate of polyoxyethylene glycol monomethyl ether was
72%. The DMF and unreacted polyoxyethylene glycol monomethyl ether were removed by maintaining the reaction-terminated liquid at 120 ° C. under vacuum, and the isobutylene-maleic anhydride copolymer was partially esterified with polyoxyethylene glycol monomethyl ether (esterification). rate
36.2 g was obtained.

Next, the obtained partially esterified product was heat-pressed at 150 ° C. × 50 kg / cm ² G for 5 minutes to prepare a sheet having a thickness of 1 mm.
When the softening point of this sheet was measured, it was 105 ° C., and a tensile test was conducted using an Instron universal testing machine (tensile speed: 50 mm
/ min), breaking strength 55 kg / cm ² G, breaking elongation 6
It was 0%.

10 g of the obtained esterified product, 4.5 g of 25% NH ₃ water, water
50 g was charged into a three-necked flask equipped with a reflux condenser, and 50
After stirring and heating at 6060 ° C. for 30 minutes, a clear aqueous solution was obtained.

Example 6 16.2 g of polyoxyethylene glycol monomethyl ether of n = 3 obtained in the same manner as in Example 1, 15.4 g of isoban-04, 0.50 g of 2-methylimidazole and 120 g of dimethylformamide were equipped with a reflux condenser. The mixture was charged into a three-necked flask, and stirred and heated at 120 to 130 ° C. for 24 hours under a stream of N ₂ to perform an esterification reaction. From the analysis value of unreacted polyoxyethylene glycol monomethyl ether in the reaction completed solution, the conversion of polyoxyethylene glycol monomethyl ether was 95%. Dimethylformamide and unreacted polyoxyethylene glycol monomethyl ether were removed by maintaining the reaction-terminated liquid at 120 ° C. under vacuum, and a partially esterified product of isobutylene-maleic anhydride copolymer with polyoxyethylene glycol monomethyl ether ( (Esterification rate 95%) 30.6 g was obtained.

Next, the obtained partially esterified product was heat-pressed at 200 ° C. × 50 kg / cm ² G for 5 minutes to prepare a transparent sheet having a thickness of 1 mm. When the softening point of this sheet was measured, it was 170.
° C, and a tensile test (tensile speed 50 mm / min) was performed with an Instron universal testing machine.
² G and elongation at break were 20%.

Further obtained esterified product 10 g, 25% NH ₃ water 4 g, water 50
g into a three-necked flask equipped with a reflux condenser, 50 to 6
After stirring and heating at 0 ° C. for 30 minutes, a clear aqueous solution was obtained.

Example 8 In an autoclave, 11.2 g of methanol and 0.15 k of metal Na were placed.
g, and after purging with nitrogen, 696.7 g of ethylene oxide was gradually charged at 110 to 150 ° C. to carry out a reaction for 10 hours. After completion of the reaction, the contents were taken out, and the average number of moles of ethylene oxide added was 45 (according to GPC analysis, n = 37 to 5 with n = 45 being the center)
A mixture of polyoxyethylene glycol monomethyl ether having an addition mole number of up to 3) was obtained.

Next, the obtained polyoxyethylene glycol monomethyl ether 20.2 g, Isobam 04 15.4 g, 2-methylimidazole 0.50g were charged dimethylformamide 140g necked flask equipped with a reflux condenser, N ₂ stream under 100 to
The esterification reaction was performed by stirring and heating at 10 ° C. for 20 hours. From the analysis value of unreacted polyoxyethylene glycol monomethyl ether in the reaction completed solution, the conversion of polyoxyethylene glycol monomethyl ether was 92%.

The reaction-terminated liquid was kept at 80 ° C. under vacuum to remove dimethylformamide as a solvent, and a partially esterified product of isobutylene-maleic anhydride copolymer with polyoxyethylene glycol monomethyl ether and unreacted polyoxyethylene glycol monomethyl ether Mixture of
35.4 g was obtained.

Next, the obtained partially esterified product was heat-pressed at 150 ° C. × 50 kg / cm ² G for 5 minutes to prepare a sheet having a thickness of 1 mm.
The softening point of this sheet was 80 ° C. When 20 g of the esterified product, 5.0 g of 25% NH ₃ water and 50 g of water were stirred and heated at 70 to 80 ° C. for 30 minutes, a clear aqueous solution was obtained.

〔The invention's effect〕

According to the present invention, a thermoplastic water-soluble resin that can be melt-molded and has excellent film properties is provided.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-92212 (JP, A) JP-A-62-292807 (JP, A) JP-A-52-145496 (JP, A) (58) Survey Field (Int.Cl. ⁶ , DB name) C08F 8 / 00,8 / 14

Claims (1)

(57) [Claims] 1. A copolymer of isobutylene and maleic anhydride with a general formula RO (AO) _n H wherein R is an alkyl group having 1 to 10 carbon atoms and A is a phenyl group. It is a good vic-alkylene group having 2 to 4 carbon atoms, and A in each () may be the same or different.
And n may be connected in a block or may be connected at random via O, and n is an integer of 1 or more). Manufacturing method of thermoplastic water-soluble resin.