JPH04368358A - N-substituted maleimide and its production - Google Patents

Abstract

PURPOSE:To obtain a new N-substituted maleimide, excellent in heat resistance of white color in itself without yellowing and suitable for use in the field of thermoplastic resins, etc., requiring high heat resistance. CONSTITUTION:An N-substituted maleimide expressed by formula I [X1 and X2 are H, halogen or 1-10C alkyl; R1 is halogen or 1-10C alkyl, provided that plural groups R1 may be same or different when the plural groups R1 are present; (m) is 0-17], e.g. 9(10)-aminomethyl-[6.2.1.1<3>,<6>.0<2>,<7>]-dodecanemaleimide. The compound expressed by formula I is obtained by carrying out cyclodehydrating reaction of a new maleamic acid expressed by formula II. The new compound expressed by formula II is-obtained by subjecting an alicyclic amine compound expressed by formula III and a maleic acid expressed by formula IV or its derivative to addition reaction.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel N-substituted maleimide and a method for producing the same.

0002

[Prior Art] N-substituted maleimides have traditionally been used as heat-resistant modifiers for thermoplastic resins such as polyvinyl chloride, polystyrene, and ABS, and as raw materials for pharmaceuticals and agricultural chemicals, and have been particularly used in the thermoplastic resin field. It accounts for the majority.

[0003] N-phenylmaleimide is known as an N-substituted maleimide used in the thermoplastic resin field, but since N-phenylmaleimide itself is yellow, when it is mixed with a resin, it is not added. The disadvantage is that the resin is colored yellow, which limits its use in applications that require transparency. In addition, to solve this drawback, N-cyclohexylmaleimide is partially used, but although it does not easily color the resin yellow, it is not satisfactory as a heat resistance modifier because it does not improve heat resistance sufficiently. Not yet reached.

0004

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel N-substituted maleimide which is white in itself without yellowing and has excellent heat resistance.

[0005]

[Means for Solving the Problems] In order to achieve the above-mentioned problems, the inventors of the present invention have made intensive studies and have completed the present invention. That is, the present invention provides general formula (I) (
6)

[0006]

embedded image (wherein, X1 and X2 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 10 carbon atoms, and R1 represents a halogen atom or an alkyl group having 1 to 10 carbon atoms. However, if there are multiple R1s (that is, m is 2 or more), the multiple R1s may be the same or different from each other. m is an integer from 0 to 17. N-substituted maleimide and general formula (II) (Chemical formula 7)

[0007]

[I
The present invention relates to a method for producing an N-substituted maleimide, which is characterized by subjecting a novel maleamic acid represented by (the same content as ) to a dehydration ring-closing reaction.

The maleamic acid represented by the general formula (II) used in the present invention is a new compound.

[0009]

[Image Omitted] Alicyclic amine compound represented by [Formula 8] (wherein R1 and m have the same contents as in general formula (I)) and general formula (IV)
(C9)

0010

It is produced by addition reaction with maleic anhydride or a derivative thereof represented by the formula (wherein, X1 and X2 have the same content as in general formula (I)).

The alicyclic amine compound used in the present invention is represented by general formula (III), and PATENTSCH-
RIFT DD 221 172. It can be manufactured according to the method described in . For example, 9(10)-cyantetracyclo-[6.2.1.13,6.02,7]
-Dodecene-(4) can be reductively aminated with a catalyst such as Raney cobalt or Raney nickel to produce 9(10)-aminomethyl-[6.2.1.13,6.02,7]-dodecane. . Furthermore, general formula (III)
, m is an integer from 0 to 17. When m is 0, it means that there is no substituent R1, and when m is 17
In the case of , all substitutable positions 1 to 12 are substituted with R1.

On the other hand, maleic anhydride or its derivative used in the reaction with the alicyclic amine compound has the general formula (IV
), specifically, maleic anhydride, 3-methyl maleic anhydride, 3-ethyl maleic anhydride, 3,4
-dimethyl maleic anhydride, 3,4-diethyl maleic anhydride, 3-chloromaleic anhydride, 3,4-dichloromaleic anhydride, and the like.

Maleamic acid is obtained by addition reaction of the above-mentioned alicyclic amine compound and maleic anhydride or its derivative, but in the method of the present invention, maleic anhydride or The derivative is 0.6~
The reaction is carried out using 1.5 times the molar amount. More preferably, it is 0.8 to 1.2 times the mole.

[0014] In the reaction, it is preferable to use a solvent, such as aliphatic hydrocarbons such as hexane, heptane, and cyclohexane, aromatic hydrocarbons such as benzene, toluene, and xylene, and halogens such as chlorobenzene and dichlorobenzene. Aromatic hydrocarbons, aprotic polar solvents such as dimethylformamide, N-methylpyrrolidone, dimethylsulfoxide, and mixed solvents thereof can be used. More preferred is an aprotic polar solvent such as dimethylformamide. The amount of the solvent to be used is preferably 1 to 20 times (by weight), more preferably 2 to 10 times (by weight) relative to the raw material amine compound.

In the reaction, maleic anhydride and the raw material amine compound may be added in their entirety from the beginning, but since heat is generated, it is preferable to add either a small amount at a time. More preferably, the maleic anhydride is completely dissolved in the solvent, and the internal temperature of the reaction vessel is 120°C or lower, preferably 30 to 100°C.
It is preferable to add the raw amine compound dropwise while stirring so as to maintain the temperature within the range of °C. At this time, the raw material amine to be added dropwise may be dissolved in the same solvent as the reaction solvent.

The time for dropping the raw material amine is preferably from 5 to 180 minutes, more preferably from 30 to 120 minutes. Although the dehydration ring-closing reaction can be carried out immediately after the completion of the dropping, it is preferable to age the maleamic acid at 30 to 120°C for about 0.5 to 3.0 hours, more preferably at 50 to 100°C for 1 hour. .0~
It is best to age for about 2.0 hours.

General formula (II) obtained by the above reaction
Regarding the dehydration ring closure reaction to obtain the N-substituted maleimide represented by the general formula (I) from the maleamic acid represented by,
There are no particular limitations, and methods known per se can be employed.

[0018] In the method of the present invention, a catalyst can be used if necessary. The catalyst used is, for example, p
- using organic acids such as toluenesulfonic acid, benzenesulfonic acid, metasulfonic acid, inorganic acids such as orthophosphoric acid, polyphosphoric acid, metasonic acid, sulfuric acid, or metal-containing compounds such as zinc, preferably metal oxides such as ZnO2, SnO2 can do. More preferred are organic acids such as orthophosphoric acid and polyphosphoric acid.

The amount of catalyst used is preferably 0.1 to 200 parts by weight, more preferably 2 to 100 parts by weight, based on 100 parts of maleamic acid. The entire amount of the catalyst may be charged at once, but depending on the amount of catalyst to be used due to the exothermic reaction, a method may be adopted in which the catalyst is charged in several batches.

[0020] The reaction temperature in the dehydration ring closure reaction is 50~
The temperature range is preferably 180°C, more preferably 60 to 16
It is preferable to carry out the reaction at about 0°C.

Regarding the reaction time, it is appropriate to continue the reaction for about 1 to 100 hours, and more preferably for 1 to 50 hours.

After completion of the dehydration ring closure reaction, the reaction solution can be purified by distillation or sublimation after removing side reactants or acid catalysts by filtration. Preferably, after removing side reactants or acid catalysts, washing with water or alkali, and recrystallizing, the N-substituted maleimide represented by general formula (I) can be obtained with high purity.

The N-substituted maleimide represented by the general formula (I) of the present invention obtained as described above is not colored yellow like conventional aromatic N-substituted maleimides, but is a white crystal. It has excellent thermal stability.

[0024]

EXAMPLES The present invention will now be explained in more detail with reference to Examples. Example 1 Stirrer, cooling condenser, thermometer, nitrogen gas introduction pipe,
5.6 g (0.057 mol) of maleic anhydride and 20 g of dimethylformamide were placed in a 100 ml four-necked glass flask equipped with a dropping funnel, and the temperature was raised to 60°C until they were completely dissolved. 9(10)-aminomethyltetracyclo[6.2.1.13,6.02,7
] 10 g (0.052 mol) of dodecane was added dropwise over 1 hour while paying attention to the reaction temperature, and the mixture was further aged at 60° C. for 2 hours to synthesize maleamic acid. Next, 20 g of polyphosphoric acid was added to the reaction solution, and the reaction temperature was raised while paying attention to the reaction temperature, and a dehydration ring-closing reaction was carried out at 90 to 95° C. for 12 hours. After the reaction was completed, the reaction mixture was cooled to room temperature, 20 g of methanol was charged, and after stirring for 1 hour, the crystals were separated by filtration. Further, the crystals were dissolved in 40 g of toluene and washed with an alkali, concentrated, and the precipitated crystals were filtered and further washed with 10 g of methanol to obtain white crystals. The weight after drying was 6.5 g. Purity: 99.9% This crystal has 9(10)-aminomethyl-[6.2.1.13,6
．． 02,7]-dodecanemaleimide. The measurement results are shown below. Elemental analysis value (%) (calculated as C17H21NO2) C
H N Theoretical value 75.25 7.80
5.16 Measured value 75.53
7.67 5.14 1H-NMR spectrum (90MHz, CDCl3 solvent)

Proton integrated intensity ratio signal based on tetracyclo ring 1.0-2.
3ppm Signal based on 17-CH2 3.3-3.5ppm
A signal 6.7 ppm 2IR spectrum (KBr method) based on the 2-olefinic double bond is shown in FIG. The thermal property test results are shown in Table-1. Comparative Example 1 Stirrer, cooling condenser, thermometer, nitrogen gas introduction pipe,
5.4 g (0.055 mol) of maleic anhydride and 10 g of dimethylformamide were placed in a 100 ml four-necked glass flask equipped with a dropping funnel, and the temperature was raised to 60°C to completely dissolve the mixture. 5 g (0.050 mol) of cyclohexylamine was added to the solution while paying attention to the reaction temperature.
The mixture was added dropwise over a period of time, and further aged at 60°C for 2 hours to synthesize maleamic acid. Next, after charging 10 g of polyphosphoric acid to the above reaction solution, the temperature was raised while paying attention to the reaction temperature.
A dehydration ring-closing reaction was carried out at 90 to 95°C for 24 hours. After the reaction was completed, it was cooled, 14 g of ethyl acetate was added, extracted, the layers were separated, the ethyl acetate layer was washed with hot water three times, and concentrated with an evaporator.
Distilled at ~130℃/2-3mmHg to produce 6.0g of white crystals.
I got it. The thermal property test results are shown in Table-1.

[0025]

[Table 1] As shown by the thermal property test results, the N-phenylmaleimide of the reference example has excellent thermal stability, but has the drawback of being yellowish. Furthermore, although N-cyclohexylmaleimide of Comparative Example 1 is white and has no problem with transparency, it has a drawback of poor thermal stability. Therefore, the N-substituted maleimide of the present invention has excellent characteristics that can solve both of the drawbacks.

[0026]

Effects of the Invention The N-substituted maleimide represented by the general formula (I) using a specific alicyclic amine compound obtained by the present invention is a new compound, and it
-Compared to substituted maleimides, it does not have the characteristic yellow color characteristic of alicyclic compounds, and has a very high thermal decomposition temperature, making it suitable for use in fields such as thermoplastic resins that require high heat resistance. Optimal.

[Brief explanation of the drawing]

FIG. 1: 9(10)-Aminomethyl-[ obtained in Example 1
6.2.1.13,6.02,7 ]-dodecanemaleimide IR spectrum.

Claims (4)

[Claims] Claim 1: General formula (I) (Chemical formula 1) [Chemical formula 1] (wherein, X1 and X2 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 10 carbon atoms, and R1 is Represents a halogen atom or an alkyl group having 1 to 10 carbon atoms.However, when there are multiple R1's (that is, when m is 2 or more), the multiple R1's may be the same or different from each other.m is 0 N-substituted maleimide represented by: Claim 2: General formula (II) (Chemical formula 2) [Chemical formula 2] (wherein, X1, X2, R1 and m are of the general formula (I
2. The method for producing an N-substituted maleimide according to claim 1, wherein a maleamic acid represented by the following formula is subjected to a dehydration ring-closing reaction. [Claim 3] An alicyclic amine compound represented by formula (III) (Chemical formula 3) [Chemical formula 3] (wherein R1 and m have the same content as in general formula (I)) and general formula (IV)
(Chemical formula 4) [Chemical formula 4] (In the formula, X1 and X2 have the same content as in general formula (I)) Maleic anhydride or its derivative is subjected to an addition reaction with the maleamic acid according to claim 2. Method. Claim 4: General formula (II) (Chemical formula 5) [Chemical formula 5] (wherein, X1, X2, R1 and m are of the general formula (I
) maleamic acid, which has the same content as ).