JPS63301226A - Production of polymaleimide - Google Patents

Abstract

PURPOSE:To produce a high-purity polymaleimide, by reacting a polyamine with maleic anhydride in a specified mixed solvent to obtain a polymaleamic acid and dehydrating this polymaleamic acid in the presence of an acid catalyst to effect ring closure while azeotropically distilling formed water from the system. CONSTITUTION:A polyamine having more than two amino groups in the mole cule [e.g., a polyamine of formula I or II (wherein n=0-4)] is reacted with maleic anhydride in a mixed solvent comprising an aromatic hydrocarbon (e.g. toluene) or a halohydrocarbon (e.g., chlorobenzene) and an aprotic polar solvent (e.g., N,N-dimethylformamide) to obtain a polymaleamic acid, which is dehydrat ed to effect ring closure in the presence of an acid catalyst (e.g., p- toluenesulfonic acid) while formed water is azeotropically distilled from the system. In this way, a high-purity polymaleimide useful as a laminate material, a sealing material, an electrical insulation material, a conductive paste or an adhesive or a structural material can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing polymaleimide, which involves reacting a polyamine and maleic anhydride to obtain polymaleamic acid, which is then subjected to dehydration and ring closure. Polymaleimides obtained by the method of the invention are useful as laminating materials, encapsulating materials, electrically insulating materials, conductive pastes, adhesives and structural materials.

(Prior Art) A method for producing polymaleimide by reacting maleic anhydride with a polyamine usually involves a two-step reaction. For example, JP-A-60-197732 discloses that ketone solvents such as acetone or N are used.

Polyamine is added to maleic anhydride in the presence of a polar solvent such as N-dimethylformamide to form polymaleamic acid, and a dehydrating agent such as acetic anhydride or sodium acetate is added to the resulting polymaleamic acid in the presence of triethylamine and a metal compound catalyst. A method of dehydrating and ring-closing the polymaleimide is disclosed below.

(Problems to be Solved by the Invention) However, in the above method, the ring-closing reaction does not proceed sufficiently, and the produced polymaleimide contains impurities such as unopened maleamic acid, by-product acetic acid, and triethylamine, and contains a large amount of impurities. Even if water is used, cleaning and purification is difficult. Further, cured products of thermosetting resins made from such polymaleimide have disadvantages such as decreased heat resistance and corrosion of aluminum wiring etc. when used as electrical insulating materials.

(Means for Solving the Problems) The present invention involves the reaction of a polyamine having at least two amino groups in one molecule and maleic anhydride with an aromatic hydrocarbon or/and a rokenized hydrocarbon and an aprotic hydrocarbon. The present invention provides a method for obtaining a high polymaleimide in a mixed solvent with a polar solvent.

(Polyamine) The polyamine having at least two amino groups in one molecule used in the present invention has the general formula % (%) [wherein Qi! It is an organic group having 3 to 150 carbon atoms, and is an n-valent organic group that can contain hydrogen, oxygen, 1 sulfur, halogen, nitrogen, phosphorus, and silicon. Specific examples of compounds include (i), the following general formula (II) [wherein, X is a hydrogen atom, a halogen atom, or a carbon number of 1 to
4 is an alkyl group or an alkoxy group. n is 0°1 to 10].

(ii), a tetrafunctional polyamine represented by the following general formula (III) (hereinafter referred to as a blank space) [wherein, X has the same meaning as the above GI) formula] (l
ii), polyamine 6 obtained from a mixture of aromatic dialdehyde and formaldehyde and aromatic amine, and other polymers of vinylanilines, triaminobenzene, triaminotoluene, triaminonaphthalene, triamino diphenyl, triamino Pyridine, triaminophenyl ether, triaminodiphenylmethane,
Triamino diphenyl sulfone, triaminobenzophenone, triaminobuenyl orne phosphate, tri(
(aminophenyl)phosphine oxide, tetraaminobenzophenone, tetraaminobenzene, tetraaminonaphthalene, diaminobenzidine, tetraaminophenyl ether, tetraaminophenylmethane, tetraaminophenyl sulfone, bis(diaminophenyl)pyridine, melamine, and the like.

(Mixed Solvent) In the method of the present invention, a mixed solvent of an aromatic hydrocarbon or halogenated hydrocarbon that can be azeotroped with water and a high boiling point aprotic polar solvent is used as the reaction solvent.

Examples of the aromatic hydrocarbon solvent include benzene, toluene, xylene, ethylbenzene, diethylbenzene, phthylbenzenes, cumene, mesitylene, and the like.

In addition, examples of halogenated hydrocarbon solvents include chloroform, dichloroethane, trichloroethylene, tetrachloroethylene, 1,2-dichloroethane, 1,2-dichloropropane, chlorobenzene, dichlorobenzene, chlorotoluene, trichloroethane, 1, Examples include 1,2,2-tetrachloroethane.

As the aprotic polar solvent, solvents that easily dissolve polyamic acid and have a high boiling point of 150°C or higher, such as N, N-
Dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, hexamethylphosphoramide, tetramethylurea, 1
．． 3-dimethyl-2-imidazolidinone or the like is used.

an aromatic hydrocarbon solvent or a halogenated hydrocarbon solvent;
The proportion of the aprotic polar solvent to be used is preferably 1 to 50% by weight in the mixed solvent.
Preferably it is 3 to 30% by weight. The mixed solvent is used in an amount of 1 to 50 parts by weight, preferably 2 to 20 parts by weight, based on the amount of polyamine 13.

(Acid catalyst) The acid catalyst used in the present invention includes sulfuric acid, sulfuric anhydride,
Examples include p-toluenesulfonic acid, phosphoric acid, polyphosphoric acid, metaphosphoric acid, condensed phosphoric acid, trichloroacetic acid, trifluoroacetic acid, trifluoromethanesulfonic acid, and the like.

The amount of these acid catalysts used is 0.0001 to 1 mol, preferably 0.001 mol, per 1 equivalent of amino group of polyamine.
~0.5 mol.

(Reaction method) Polymaleimide is produced by adding maleic anhydride in an amount of 0.9 to 2 mol, preferably 1.0 to 1.3 mol, per equivalent of amine group of polyamine, and aromatic hydrocarbon or...
After producing polymaleamic acid (first stage) through an addition reaction in a mixed solvent of hydrogen fluoride and an aprotic polar solvent at a temperature range of 0 to 150°C, no isolation is required. A dehydration ring-closing reaction (second stage) is carried out in the presence of an acid catalyst in a temperature range of 80 to 200°C, and the produced water is azeotropically removed to obtain a polymaleimide.

After the reaction is complete, the reaction product solution is added to a poor solvent (precipitant) or a poor solvent is added to the reaction product solution to precipitate the polymaleimide, followed by separation, washing, and drying.
'-- Examples of the poor solvent include water, aqueous solutions of basic compounds, alcohols such as methanol, ethanol, n-7' lobanol, and inpropyl alcohol, hexane, heptane,
Examples include hydrocarbon compounds such as octane and cyclohexane.

(Example) Hereinafter, the present invention will be explained in more detail with reference to Examples. still,
The following polyamines were used in the following examples.

Polyamine A A mixture of polyamines containing 77% of the polyamine represented by the following formula, obtained by reacting 8 moles of aniline with 1 mole of 1.3-benzenedialdehyde Softening point of this polyamine (capillary method) is 115-121
℃, the neutralization equivalent was 118.

Polyamine B A red transparent solid polyamine obtained using 1 to 4 moles of 4-benzenedialdehyde, 4 moles of 0-toluidine, and 4 moles of aniline as raw materials.

The softening point of this polyamine was 122 to 128°C, and the neutralization equivalent was 126.

Polyamine C A reddish-brown, dark liquid polyamine obtained by using 4 moles of aniline as a raw material per 1 mole of formalin. This polyamine has n=0.4 and a neutralization equivalent of 10
It was 1.

Example 1 Maleic anhydride 2 was placed in a 3 001117 four-hole flask equipped with a dropping funnel, a thermometer, a stirrer and a water separator.
1.69 and toluene 86.4? and bring the internal temperature to 70℃.
It stabilized. Next, add 55% of polyamine A23.6F to toluene.
5.2 f and N,N-dimethylformamide 23.
A solution dissolved in 6 t was added dropwise over 1 hour.

Subsequently, after adding 1.92 g of para-toluenesulfonic acid, the temperature was raised and kept at 114° C. for 6 hours to carry out the reaction. The water produced during this time was distilled off together with toluene.

Thereafter, the temperature of the reaction solution was raised to 120° C. while toluene was distilled off under normal pressure. This reaction solution was added dropwise to 500 liters of pure water, and the precipitated polymaleimide was separated into 800117
After washing with pure water and drying, a pale yellow polymaleimide 38
．． 4F (yield 97%) was obtained.

The melting point of this polymaleimide is 172 to 180°C,
The acid value was 8-2 (q-KOa/f).

Example 2 In a flask equipped with the same equipment as in Example 1, 25.2 f of polyamine B and 198.4 f of chlorobenzene were placed. and 19.8 P of N-methyl-2-pyrrolidone were charged and dissolved.

Then 21.6 r of maleic anhydride was added and heated to 40°C.
After carrying out the addition reaction for 30 minutes at a temperature of Allowed time to react.

Thereafter, the temperature of the reaction solution was raised to 145° C. while chlorobenzene was distilled off under normal pressure. This reaction solution was poured with methanol at 500 mK@, and the precipitated polymaleimide was separated in a furnace, washed with 500 m/m of methanol, and dried to obtain 39.69 mK of pale yellow polymaleimide (yield: 96%).

The melting point of this polymaleimide is 182-188°C.
The acid value was 7.5 (tq-KOH/r).

Example 3 Into a flask equipped with the same equipment as in Example 1, 21.6 t of maleic anhydride and 64.8 ft of xylene were charged. Next, a solution of polyamine C20,2t dissolved in 20.2 f of N,N-dimethylacetamide and 56.42 f of xylene was added dropwise over 30 minutes while controlling the me in the flask to 30°C.

Continuation 1/1 After adding 1.9 f of para-toluenesulfonic acid, the temperature was raised, and the temperature was maintained at 146°C, and the reaction was carried out for 3 hours while removing water produced by the reaction by an azeotropic operation with xylene.

Thereafter, the reaction solution was heated to 150° C. while xylene was distilled off under normal pressure. After cooling this reaction solution to 30°C, 1% sodium carbonate SOO was added to the reaction solution to precipitate polymaleimide, which was then separated into a furnace.
After washing twice with pure water, dry to a light yellow color of polymaleimide 34.4? (yield 95%).

This polymaleimide has a melting point of 74-78°C and an acid value of 5.
5 (W-KOH7f).

Comparative Example Maleic anhydride 21
．． 69 and 43.2 f of acetone were added and dissolved with stirring. A solution of polyamine C20,2f in 70.72 g of acetone was dropped into the four-day flask kept at 25 to 35° C. over a period of 1 hour. Then 0.2 f of nickel acetate
, 25.5 f of acetic anhydride, and 5 d of triethylamine were added with stirring, and the mixture was allowed to react at 65° C. for 2 hours.

Thereafter, it was cooled to room temperature, dropped into 500 jIt of pure water, and the precipitate deposited was separated in a furnace, washed twice with 1 T of pure water, and dried to produce yellowish brown polymaleimide 32.62 (yield 90%).
) was obtained.

The melting point of this polymaleimide is 70-77℃, and the acid value is 18.
．． It was 6 (Misaki-KO Ruri).

Examples 4 to 9 Polymaleimides were obtained by changing the types of polyamine, solvent, acid catalyst, precipitant, reaction temperature, etc. as shown in Table 1. The results are shown in Table 1.

(Margin below)

Claims (1)

[Claims] 1) Polymaleamide is produced by reacting a polyamine having at least two amino groups in one molecule and maleic anhydride with an aromatic hydrocarbon or a halogenated hydrocarbon in a mixed solvent of an aprotic polar solvent. After getting the acid,
A method for producing polymaleimide by dehydrating and ring-closing the polymaleamic acid in the presence of an acid catalyst and azeotropically removing the produced water.