JPH0228150A - N-substituted maleimide, n-substituted maleamic acid and production thereof - Google Patents

Abstract

NEW MATERIAL:The N-substituted maleimide of formula I (R is H or 1-4C alkyl; n is 0 or 1). EXAMPLE:N-norbornylmethylmaleimide. USE:Useful as an agent for improving heat-resistance of thermoplastic resin. A heat-resistant resin can be produced by copolymerizing the compound of formula I to the monomer component of a thermoplastic resin such as methacrylate resin, styrene resin, ABS resin, vinyl chloride resin or vinyl acetate resin. The amount of the copolymerized compound of formula I is preferably 5-60wt.% to obtain a thermoplastic resin having excellent heat-resistance and transparency and good moldability. PREPARATION:The objective compound of formula I can be produced by reacting 1mol of an amine compound of formula II with preferably 0.6-1.2mol of maleic anhydride in a solvent such as octane and subjecting the resultant compound of formula III to dehydrative cyclization.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to novel N-substituted maleimides and N-substituted maleamic acids useful as heat resistance improvers for thermoplastic resins, and methods for producing them.

[Conventional technology]

Conventionally, vinyl thermoplastic resins such as methacrylic resin, styrene resin, ABS resin, vinyl chloride resin, and vinyl acetate resin have been widely used for various purposes because they have excellent processability and are relatively inexpensive. It has the disadvantage that it cannot be used in fields subject to high heat because it does not have sufficient heat resistance.

Therefore, in order to improve the heat resistance of the above-mentioned vinyl thermoplastic resins, methods have been proposed in which various N-substituted maleimides are copolymerized. For example, a method of copolymerizing N-phenylmaleimide (Japanese Patent Publication Nos. 43-9753, 56179034, 57-45692,
58162616, No. 58-206657, etc.), and a method of copolymerizing N-cyclohexylmaleimide (Japanese Patent Laid-Open No. 156115/1989, etc.).

[Problem to be solved by the invention]

However, the above methods for improving the heat resistance of vinyl thermoplastic resins have various problems.The method of copolymerizing N-phenylmaleimide improves the heat resistance, but the N-phenylmaleimide itself Since it is yellow, there is a problem that not only is it impossible to obtain a colorless and transparent resin, but the resin is also significantly colored. In addition, although the method of copolymerizing N-cyclohexylmaleimide produces a resin with excellent transparency and almost no coloring, the heat resistance is not sufficiently improved (and it is difficult to obtain a satisfactory product). I can't.

Therefore, the present inventors improved the heat resistance of the vinyl thermoplastic resin by copolymerizing it with a vinyl monomer.
We have conducted extensive research with the goal of developing an N-substituted maleimide that can yield a colorless and transparent resin that is significantly improved over the copolymerization of phenylmaleimide and N-cyclohexylmaleimide. As a result, it was discovered that the above problems could be solved by substitution with a norbornyl group, and the present invention was completed.

[Means to solve the problem]

That is, the present invention provides a general formula (r): [wherein R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n is 0
or 1].

The present invention will be explained in detail below.

The N-substituted maleimide represented by the general formula (1) used in the present invention is composed of an amine compound represented by the general formula [■]: [wherein R and n have the same meanings as above] and maleic anhydride. After addition, a maleamic acid represented by the general formula [■]: [wherein R and n are as defined above] is obtained, and then this maleamic acid is subjected to dehydration ring closure.

The amine compound represented by the general formula (III) used in the present invention is a known compound, for example, -
The amine compound of n=1 in formula i CI[l] is,
For example, a metal material that can be synthesized by the following route has the general formula [■]:

A 2-cyanobicyclo(2,2,1)hept-5-ene derivative represented by the formula C, in which R has the same meaning as above, was hydrogenated using Raney cobalt as a hydrogenation catalyst at a reaction temperature of 100 to 140°C. °C1 preferably 115-125 °C1
Pressure 30-60kg/cnl, preferably 40-50k
It can be obtained by hydrogenation at g/cffl.

Further, the compound represented by the above general formula [IV] is also a known compound, for example, a compound represented by the general formula [■]: [wherein R has the same meaning as above] is mixed with acrylonitrile and Diels-Alder. It can be obtained by reaction.

In addition, the production of the N-substituted maleimide according to the present invention, where n=0 in -C formula (I[I), can be carried out by, as described above,
A step (first step) of adding maleic anhydride to an amine compound represented by general formula (I [I) to produce maleamic acid represented by general formula (II); and
By dehydrating and ring-closing maleamic acid represented by general formula (I)
Step to obtain an N-substituted maleimide represented by (second step)
It can be divided into

Although the first step and the second step can be performed separately or continuously, it is preferable to perform them continuously from the viewpoint of efficiency. Each step will be explained in more detail below.

In the first step, 0.6 to 1.2 of maleic anhydride is added to 1 mole of the amine compound represented by the general formula [I[1].
It is preferable to react a mole, more preferably 1 mole. This is to prevent unreacted raw materials from remaining in the reaction product.

It is preferable to use a solvent during the reaction, and known solvents for maleimide acid synthesis can be used. However, in order to perform the first and second steps continuously, dehydration Solvents that can azeotropically remove water produced in the ring-closing reaction, are inert, and do not participate in the reaction are preferred, such as paraffinic solvents such as octane, nonane, decane, dodecane, trimethylhexane, tetrachloroethane, and ethylcyclohexane; benzene, toluene,
xylene, ethylbenzene, cumene, mesitylene, t-
Butylbenzene, pseudocumene, chlorhenzene, 0
~Aromatic systems such as dichlorobenzene, m-dichlorobenzene, p~dichlorobenzene, butylbenzene, p-cymene, n-butylbenzene, 5eC-butylbenzene, tetrahydronaphthalene, decahydronaphthalene, naphthalene, and cyclohexylbenzene Solvents can be used. Tetrahydronaphthalene and p-cymene are preferred. The amount of solvent used is 1 to 2 per amine compound as the raw material.
It is preferably 0 times M (weight), and 4 to IO times M (weight).
weight) is more preferable. .

During the reaction, the entire amount of the amine compound and maleic anhydride may be charged from the beginning, but since the reaction is exothermic, it is more preferable to add one of the two later, and more preferably, the maleic anhydride is completely dissolved in the solvent. under stirring for 15 to 12 minutes, taking care to maintain the temperature below 120"C, preferably 30-100"C, in a heated flask.
The amine compound is added dropwise over 0 minutes, and maleic anhydride is mainly added to the amine compound to obtain maleamic acid represented by -C formula (II). At this time, the amine compound to be added may be dissolved in the same solvent as in the flask.

In the second step, all the solvents that can be used in the first step can be used, but in order to perform the first and second steps continuously, it is possible to use the solvent used in the first step as is. preferable. Since the amount used is the same as that in the first step, there is no need to add a new solvent when performing the reaction continuously.

In the second step, Lewis acids such as boron trifluoride, mineral acids such as sulfuric acid, sulfuric anhydride, orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, p-toluenesulfonic acid, Hensensulfonic acid, methanesulfonic acid, etc. are used as acid catalysts. It is preferable to use organic acids, heteropolyacids such as phosphotungstic acid, silicotungstic acid, and the like. The amount used is preferably 5 to 150 weight percent based on the amine compound. More preferably, it is 20 to 100% by weight. The entire amount of the catalyst may be added at once, but it may also be added in several portions. If the amount of the catalyst is small, the effect of promoting the reaction is small, and if the amount is too large, there is no particular advantage.

The reaction is preferably carried out at a temperature of 140 to 270°C for dehydration condensation (dehydration ring closure). It is more preferable to carry out the dehydration condensation by raising the temperature to 170 to 250"C. This time may vary depending on the scale of the hatch, the catalyst, and the reaction conditions employed.
A can do it.

In the dehydration ring closure reaction, the metal-containing compound is an oxide, acetate, maleate, or succinate of at least one metal selected from the group consisting of zinc, chromium, palladium, cobalt, nickel, iron, and aluminum. , nitrates, phosphates, chlorides, sulfates, etc. are preferably added, among which zinc acetate is particularly effective. The amount of these used is 0 to 1 mole of maleamic acid.
0.005 to 0.5 mol% is preferred. More preferably 0.01 to 0.3 mol%.

Furthermore, as a stabilizer, a polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether, 2,4-dimethyl-6t-butylphenol, p-benzoquinone, 25-diphenyl-p-benzoquinone, phenothiazine, n-nitrosodiphenylamine, copper salt, etc. It is preferable to add 2000 ppm.

After the completion of the dehydration ring-closing reaction, if an acid catalyst is used, wash the reaction solution in water or alkaline water such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, etc., or wash with neutralized water to remove the catalyst. The catalyst is removed by adding an alkali powder such as sodium carbonate, sodium hydrogen carbonate, or magnesium oxide, stirring, and then passing through neutralized salt. In addition, the acid catalyst can be removed by neutralizing the catalyst.

After the completion of the dehydration ring-closing reaction (if an acid catalyst is used, carry out the above treatment). ), the reaction solution is heated under reduced pressure to remove the reaction solvent, and then purified by vacuum distillation or sublimation to obtain a highly pure N-substituted maleimide represented by general formula (1).

The N-substituted maleimide thus obtainable is a white crystal.

In addition, the formula (1
) can be produced.

For example, i) an amine compound and maleic anhydride are reacted, and the resulting maleamic acid is heated and dehydrated and ring-closed with a solvent such as toluene, xylene, or chlorobenzene, and an acid catalyst such as sulfur trisulfide, sulfuric acid, orthophosphoric acid; A production method in which the produced water is distilled out of the yarn by azeotropy with a solvent,
ii) An amine compound and maleic anhydride are reacted in an organic solvent, and the generated maleamic acid is dehydrated and ring-closed in the coexistence of an aprotic polar solvent such as dimethylformamide or dimethyl sulfoxide and an acid catalyst without isolation. production method, iii) production method of dehydrating and ring-closing maleamic acid in the presence of a dehydrating carboxylic anhydride using a tertiary amine as a catalyst; iv) producing maleamic acid in an organic solvent capable of azeotroping with water using an acid catalyst, zinc, etc. Examples include a production method in which dehydration and ring closure are carried out at a reaction temperature in the range of 170 to 250°C in the coexistence of a metal-containing compound and a stabilizer. The production method iv) is preferred.

The obtained N-substituted maleimide represented by the general formula (1) is used in the production of vinyl thermoplastic resins such as methacrylic resins, styrene resins, ABSg4 resins, vinyl chloride resins, and vinyl acetate resins. By copolymerizing with the monomer component, the heat resistance of the resulting vinyl thermoplastic resin can be significantly improved. Further, other polymerizable unsaturated monomers that can be copolymerized with these can also be blended and copolymerized.

In the present invention, other polymerizable unsaturated monomers include unsaturated fatty acid esters, aromatic vinyl compounds, vinyl cyanide compounds, and N-substituted maleimides not included in general formula CI).

Examples of unsaturated fatty acid esters include acrylic acid alkyl esters such as methyl acrylate, ethyl acrylate, isopropyl acrylate, butyl acrylate, hexyl acrylate, and 2-ethylhexyl acrylate, cyclohexyl acrylate, and tricyclo(5,2) acrylate. ,1,0
``°6] Acrylic acid cycloalkyl esters such as decar-8-yl and isobornyl acrylate, acrylic acid aromatic esters such as phenyl acrylate and benzyl acrylate, acrylic acid esters such as glycidyl acrylate, methyl methacrylate, and methacrylic acid. Methacrylic acid alkyl esters such as ethyl, isopropyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, tricyclo(5,2,1,02°6]deca-8
Examples include methacrylic acid cycloalkyl esters such as -yl and isobornyl methacrylate, methacrylic acid aromatic esters such as phenyl methacrylate and hensyl methacrylate, and methacrylic acid esters such as glycidyl methacrylate.

Examples of aromatic vinyl compounds include α-methylstyrene, α
There are α-substituted styrenes such as -ethylstyrene, and nuclear substituted styrenes such as chlorostyrene, vinyltoluene, and t-butylstyrene.

Furthermore, examples of vinyl cyanide compounds include acrylonitrile and methacrylonitrile.

N-substituted maleimides not included in general formula CI) include N-methylmaleimide, N-ethylmaleimide, N-ethylmaleimide,
-isopropylmaleimide, N-butylmaleimide, N
- aliphatic N-substituted maleimide such as lauryl maleimide,
Examples include alicyclic N-substituted maleimides such as N-cyclohexylmaleimide, aromatic N-substituted maleimides such as N-phenylmaleimide, N-methylphenylmaleimide, N-chlorophenylmaleimide, and N-methoxyphenylmaleimide.

In order to obtain a thermoplastic resin with excellent heat resistance and transparency, and good moldability, it is preferable to contain 5 to 60 percent of N-substituted maleimide of the general formula /H''.N-substituted If there are too few maleimide trenches, it will be difficult to fully achieve the above effects, and if there are too many, moldability may deteriorate.

To produce a thermoplastic resin, copolymerization can be carried out by known methods such as radical polymerization and ionic polymerization. For example, it can be produced by methods such as bulk polymerization, solution polymerization, and suspension polymerization in the presence of a polymerization initiator.

Examples of the polymerization initiator include benzoyl peroxide lauroyl peroxide, di-butyl peroxy hexahydrophthalate, L-butylperoxy 2-ethylhexanoate, l,1-di-phthyl beroxy-3.3.5 −
Organic peroxides such as 1-limethylcyclohexane, abbisisobutyronitrile, azobis-4-methoxy-2,
By a combination of azo compounds such as 4-dimethylvaleronitrile, azobiscyclohexanone-1-carbonitrile, and azodibenzoyl, a water-soluble catalyst represented by potassium persulfate, and ammonium persulfate, and a peroxide or persulfate and a reducing agent. Any redox catalyst that can be used in normal radical polymerization can be used.

The polymerization catalyst is preferably used in an amount of 0.01 to 10% by weight based on the total amount of monomers. Mercaptan compounds, thioglycol, carbon tetrabromide as polymerization regulators,
α-methylstyrene dimer or the like may be added as necessary to adjust the molecular weight.

The polymerization temperature is preferably in the range of 0 to 200'C.

More preferably, the temperature is 50 to 150°C.

Solvents for solution polymerization include Hensen, toluene,
xylene, methyl ethyl ketone, methyl isobutyl ketone]
-N, ethyl acetate, butyl acetate, dichloroethylene, etc. can be used. - The suspension polymerization is carried out in an aqueous medium, suspending agents and, if necessary, suspending aids may be added. Suspending agents include water-soluble polymeric substances such as polyvinyl alcohol, methylcellulose, and polyacrylamide;
Examples include poorly soluble inorganic substances such as calcium phosphate and magnesium birophosphate. The water-soluble polymer substance is used in an amount of 0.03 to 1% by weight based on the total amount of monomers, and the sparingly soluble inorganic substance is used in an amount of 0.05 to 0.5% by weight based on the total amount of monomers. is preferable. Suspending aids include anionic surfactants such as sodium dodecylhenzenesulfonate, and when using sparingly soluble inorganic substances as suspending agents, g
It is preferable to use a clouding aid in combination. The suspension aid is preferably used in an amount of 0.02 to 0.02 weight based on the total amount of monomers.

〔Example〕

The present invention will be specifically explained below with reference to Examples, but the present invention is not limited thereto.

Example 1 [Synthesis of N-norbornylmethylmaleimide] Stirrer,
49.98 g (0.51 mol) of maleic anhydride and 49.98 g of p-cymene were placed in a 1 000 ml four-eye glass flask equipped with a thermometer, dropping funnel, and reflux condenser with oil-water separator. After charging and raising the temperature while stirring to completely dissolve maleic anhydride in P-cymene at about 60°C, add norbornyl while being careful to maintain the temperature inside the flask below 100°C. 63.75 g (0.51 mol) of methylamine were mixed with 382.7 g (0.51 mol) of p-cymene.
A solution of 5 g of p-cymene was added dropwise under stirring over 1 hour to synthesize a slurry of p-cymene of N-norbornylmethylmaleamic acid.

Next, 45.5 g of orthophosphoric acid, 0.3774 g of zinc acetate, and 0.0569 g of hydroquinone were added to the slurry liquid.
After adding 0.0569 g of cupric chloride, the temperature was not raised, and when the temperature inside the flask reached about 150''C, water began to distill out together with p-cymene.

Thereafter, the temperature was further raised to about 180°C, and the reaction was carried out for 7 hours while water produced by the reaction was distilled out of the system together with p-cymene. After the reaction was completed, the acid catalyst layer precipitated in the lower layer was separated and removed.

Subsequently, 200 ml of ion-exchanged water was added to the reaction solution, and the mixture was stirred and washed with water at about 60'C for 30 minutes to separate and remove water J5. After repeating this operation once more, the reaction solution was transferred to a 2p separating funnel and washed repeatedly with ion-exchanged water to completely remove the catalyst. Thereafter, in order to remove a trace amount of water remaining, anhydrous sodium sulfate was added to the reaction solution after washing with water, and after thorough stirring, the sodium sulfate was removed using a funnel.

After water washing and dehydration, 0.0569 g of hydroquinone and 0.0569 g of cupric chloride were newly added to the reaction solution, which was then subjected to an evaporator to completely remove the solvent p-cymene to obtain light brown crystals. .

Next, the light brown crystals obtained as described above were
The product was purified by sublimation at 10°C, 1Q, and 1 wtlg to obtain 62.7 g of white crystals.

The analysis results of the obtained white crystals are shown below.

First, elemental analysis was performed and the results were as follows.

Element CHO Theoretical value (%) 70.22 7.37 6.8
2 Actual value (%) 70.15 7. lI 5
6.76 Also, using deuterated chloroform as a solvent ')(-
Analysis of the NMR spectrum revealed that the norbornyl group signal was around 1.0 to 2.4 ppm, and the methylene signal based on norbornylmethylamine was around 3.1 to 3 ppm.
．． Around 6 ppm, a signal of an olefinic double bond based on maleic anhydride exists around 5.65 ppm,
When the integrated intensity ratio of this proton was measured, it was found to be 11:2.
: It was 2. This 'H-NMR vector is shown in FIG.

From the above analysis results, it was confirmed that the obtained white crystals were N-norbornylmethylmaleimide.

Example 2 [Synthesis of N-norbornylmaleimide] Into the same flask as in Example 1, 49.98 g of maleic anhydride (0.5
1 mole) and 49.98 g of p-cymene were charged, and the temperature was raised while stirring to completely dissolve maleic anhydride in p-cymene at approximately 60°C, and then the temperature inside the flask reached 100°C.
56.61 g (0.51 mol) of 2-aminonorbornane was added to p-cymene 3, taking care to maintain the concentration below C.
A solution in which 39.7 g of N norbornyl maleamic acid was dissolved was added dropwise over 1 hour with stirring to produce a slurry of N norbornyl maleamic acid in p-cymene.

Next, after adding 42.6 g of orthophosphoric acid, 0.3519 g of zinc acetate, 0.0533 g of hydroquinone, and 0.0533 g of cupric chloride to the slurry liquid, the temperature was raised, and the same reaction as in Example 1 was carried out. After post-treatment and purification, 58.6 g of white crystals were obtained.

When the 'H-N~IR spectrum was analyzed using deuterated chloroform as a solvent, the signal of the norbornyl group was 1.0.
~2.4 ppm, the proton signal at the maleimide-substituted position of the norbornyl group is 3.9 pp+
11, a signal of an olefinic double bond based on maleic anhydride was present at around 6.6 ppm, and when the integrated intensity ratio of this proton was measured, it was 10:1:2. This 'H-NMR spectrum is shown in FIG.

From the above analysis results, it was confirmed that the obtained white crystals were N-norbornylmaleimide.

Reference Example 1 10 g of N-norbornylmethylmaleimide obtained in Example 1, 90 g of methyl methacrylate, and 0 laroyl peroxide were placed in a 500 rtdl Erlenmeyer flask equipped with a three-way stopcock.
．． Prepare 4g and 0.2g of lauroyl mercaptan,
After mixing and dissolving, and purging the inside of the flask with nitrogen gas, the flask was immersed in a constant temperature water bath at 60°C while stirring and shaking, and polymerized for 30 minutes under a nitrogen stream to obtain a partially polymerized product. Subsequently, this partially polymerized product was injected into a glass cell and polymerized at 65°C for 5 hours, and then at 100°C for 2 hours to obtain a transparent sheet-like resin (A).

Reference Example 2 N obtained in Example 1 was placed in an Erlenmeyer flask similar to Reference Example 1.
-norbornylmethylmaleimi)'', 80 g of methyl mecturate, 0.4 g of iQ lauroyl oxide, and 0.2 g of lauroyl mercaptan, and the same procedure as in Reference Example 1 was conducted to obtain resin CB).

Reference Example 3 N obtained in Example 2 was placed in an Erlenmeyer flask similar to Reference Example 1.
- Norbornylmaleimide log, 90 g of methyl methacrylate, 0.4 g of lauroyl peroxide and 0.2 g of lauroyl mercaptan were charged and the procedure was carried out in exactly the same manner as in Reference Example 1 to obtain a resin (C).

Reference Example 4 N obtained in Example 2 was placed in an Erlenmeyer flask similar to Reference Example 1.
- 20 g of norbornylmaleimide, 80 g of methyl methacrylate, 0.4 g of lauroyl peroxide and 0.2 g of lauroyl mercaptan were charged, and the procedure was carried out in exactly the same manner as in Reference Example 1 to obtain resin [1].

Reference Examples 5 to 9 In the same Erlenmeyer flask as in Reference Example 1, N-phenylmaleimide (manufactured by Nippon Shokubai Kagaku Kogyo C Kiku, trade name Imilenox-P) was added.
) or N-cyclohexylmaleimide (manufactured by I'FALTZ & BAUER), methyl methacrylate, lauroyl peroxide, and lauroyl mercaptan in the formulation shown in Table 1, and exactly the same as in Reference Example 1. Resins [E) to (1) were obtained.

50 g of resin [A] ~ (1) obtained as above was changed to 250 g of tetrahydrofuran? After cooling, the resulting solution was stirred and poured into 2500 g of methanol to precipitate the resin, which was dried daily to obtain a white powdery resin. The glass transition temperature and thermal decomposition temperature of this resin were measured by the following methods, and the results are shown in Table 2.

"Stupid" Glass transition temperature (Tg) It was determined using a differential scanning calorimeter (DSC).

Thermal decomposition temperature (Td) Measured by thermogravimetric analysis under the following conditions, and the temperature at which 5% by weight disappeared was read.

Atmosphere: 20 m of air, 11 minutes, heating rate = 5°C/min (blank below) Table 1 (unit double placement) Reference Example 10 N obtained in Example 1 was placed in an Erlenmeyer flask similar to Reference Example 1.
-Norbornylmethylmaleimide 10g, styrene 90g
g and 0.4 g of lauroyl peroxide, and the same procedure as in Reference Example 1 was carried out to inject the obtained partial polymer into a glass cell, polymerize at 120°C for 5 hours, and then heat at 150°C.
Polymerization was carried out for 2 hours to obtain a transparent sheet-like resin (J).

Reference Example 11 N obtained in Example 1 was placed in an Erlenmeyer flask similar to Reference Example 1.
- 20 g of norbornylmethylmaleimi f'', 80 g of styrene and 0.4 g of lauroyl peroxide were charged, and the same operation as in Reference Example 10 was carried out to obtain a resin [K].

Reference Example 12 N obtained in Example 2 was placed in an Erlenmeyer flask similar to Reference Example 1.
- Norbornylmaleimide log, 90 g of styrene and 0.4 g of lauroyl peroxide were charged, and Reference Example 10 and total (
A similar operation was performed to obtain resin (L).

Reference Example 13 N obtained in Example 2 was placed in an Erlenmeyer flask similar to Reference Example 1.
- 20 g of norbornylmaleimide, 80 g of styrene and 0.4 g of lauroyl peroxide were charged, and the same operation as in Reference Example 10 was carried out to obtain a resin (Mal).

Reference Examples 14 to 18 N-phenylmaleimide (manufactured by Nippon Shokubai Kagaku Kogyo ■, trade name Imilex-P) was placed in the same Erlenmeyer flask as in Reference Example 1.
Alternatively, N-cyclohexylmaleimide (manufactured by PFALTZ 3! BAtlER), styrene and lauroyl peroxide were prepared in the formulation shown in Table 3, and the procedure was carried out in exactly the same manner as in Reference Example 10 to obtain a resin ( N)
~CR] was obtained.

After dissolving 50 g of the resins (N) to (R) obtained in the above manner in 250 g of tetrahydrofuran, the obtained solution was stirred and poured into 2500 g of methanol to precipitate and precipitate the resin, which was then cracked and dried. A white powdery resin was obtained.The glass transition temperature and thermal decomposition temperature of this resin were determined according to Reference Example 1.
The results are shown in Table 4.

(Hereinafter, blank space) As is clear from the above results, Examples 1 to 2 of the present invention
The resin containing the N-substituted maleimide obtained in the above as a monomer component exhibits better heat resistance than the resin containing N-phenylmaleimide or N-cyclohexylmaleimide as a monomer component.

[Effects of the Invention] The thermoplastic vinyl resin obtained by copolymerizing N-substituted maleimide obtained by the present invention exhibits excellent heat resistance and a colorless and transparent hue.

[Brief explanation of the drawing]

Figure 1 shows the 'H-NMR spectrum of N-norbornylmethylmaleimide obtained in Example 1, and Figure 2 shows the IH of N-norbornylmaleimide obtained in Example 2.
-NMR spectrum. Agent Patent Attorney Kunihiko Wakabayashi

Claims (1)

[Claims] 1. General formula [I]: ▲There are mathematical formulas, chemical formulas, tables, etc.▼[I] [In the formula, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n is 0 or 1]. 2. General formula [II]: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [II] [In the formula, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n is 0 or 1] N-substituted maleamic acid represented by: 3. General formula [III]: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [III] [In the formula, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n is 0 or 1] A general formula characterized by reacting an amine compound and maleic anhydride [
II]: ▲There are mathematical formulas, chemical formulas, tables, etc.▼[II] N-substituted maleamide represented by [In the formula, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n is 0 or 1] Acid production method. 4. General formula [II]: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [II] [In the formula, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n is 0 or 1] General formula [I] characterized by dehydration and ring closure of N-substituted maleamic acid
: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] N-substituted maleimide represented by [In the formula, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n is 0 or 1] Manufacturing method.