JPS62155256A - Bismaleimide and its production - Google Patents

Abstract

NEW MATERIAL:A bismaleimide of formula I (R1-R4 are H, lower alkyl). USE:A monomer for heat-resistant polymers. It has high solubility in low-boiling solvents and the polyimode resins therefrom are soluble in solvents and flexible and can reduce troubles of remaining solvents which might cause the performance deterioration of the laminated and formed products. Further, it can improve operability, save energy consumption and is used as an insulation material, heat-resistant adhesive, coating, etc. PREPARATION:The condensation reaction of a diamine bearing an ether linkage of formula II with maleic anhydride is carried out in an organic solvent such as acetone. Then, acetic anhydride is used as a dehydration agent to effect the dehydrative cyclization in the presence of a base such as triethylamine and catalysts such as magnesium oxide and cobalt (II) acetate to give the compound of formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a bismaleimide compound useful as a hexamer of heat-resistant polymers and a method for producing the same. More specifically, bismaleimide represented by the general formula (1) (wherein R7-R4 represent hydrogen or a lower alkyl group and may be the same or different) and this compound are represented by the general formula ( U) It relates to a method of producing by reacting a diamine having an ether bond represented by the formula (wherein R1-R1 has the same meaning as in general formula (1)) with maleic anhydride.

(Prior Art) Conventionally, resins having an imide structure have exhibited excellent performance in electrical insulation, heat resistance, and dimensional stability of molded products, and have been widely used in industry. For example, polyimide resins, boamine-modified polymaleimide resins, etc. are known as heat-resistant thermosetting resins used in electrical insulation materials, and are widely used in impregnated varnishes, laminates, molded products, etc. .

However, although these conventional resins are generally excellent in terms of heat resistance, their curing speed is slow and their crosslinking density is too high, making them brittle (and prone to cranking during heating and cooling, resulting in poor mechanical strength). It has drawbacks such as low (, impractical for the purpose of casting resin.Furthermore, N, N'-(4,4°
Polymaleimide resins containing conventional bismaleimide compounds such as (methylene diphenylene) bismaleimide have a high melting point before curing, and therefore need to be used in the form of a solution. Moreover, in that case, conventional bismaleimide compounds are hardly used as general-purpose organic solvents with low boiling points. tj not understood, N-methylpyrrolidinone, N.

It has the disadvantage that it cannot be used by dissolving it in a special solvent with a high boiling point and hygroscopicity such as N-dimethylacetamide, so it must be used after being dissolved in a special solvent. Therefore,
The use of impregnated varnishes prepared by dissolving them in these solvents requires high temperatures to remove the solvents, and the solvents tend to remain in the preplex made from the varnishes, significantly reducing the performance of the desired laminate. This is a major cause.

On the other hand, as a bismaleimide compound, 2,2-bis(4
It is known that when a bismaleimide compound containing -(4-aminophenoxy)phenyl]propane as a diamine component is used, flexibility is imparted to a polymaleimide resin (Japanese Patent Application Laid-Open No. 103162/1983).

(Problems to be Solved by the Invention) An object of the present invention is to provide a bismaleimide compound that is not only heat resistant but also has good solubility in general-purpose organic solvents and excellent flexibility.

(Means for Solving the Problems) The present inventors have developed polyimide resins containing ether diamines having various structures as constituent components.

Among these, polyimide resins using diamines having an amino group at the m-position of the ether bond as the diamine component have better molding processability than polyimide resins using diamines having an amine group at the p-position. It was discovered that it has excellent solvent solubility, adhesive strength and flexibility, and an application was previously filed (Japanese Patent Application No. 59-265220).

Furthermore, the present inventors have further discovered that a polyimide resin containing the novel bismaleimide compound represented by the general formula (1) as a diamine component has excellent solvent solubility and flexibility.

Based on this idea, the present inventors have made extensive studies to solve the problems of the present invention. As a result, the novel bismaleimide compound represented by the general formula (1) has high solubility in low boiling point solvents such as dichloromethane, dioxane, and tetrahydrofuran, and furthermore, this compound has a high solubility in diamines represented by the general formula (II). It was discovered that it can be easily produced by condensing and dehydrating maleic anhydride and maleic anhydride, leading to the completion of the present invention.

That is, the present invention is a solvent-soluble bismaleimide compound and a method for producing the same.

As an example of the heat resistance scale, the melting points of the compounds of the present invention are shown in Table 1, and Table 2 shows the 5% weight ff1M low temperature in air.

Table 2 In both cases of 5% weight loss and insulation of bismaleimide, the demand % weight loss temperature is 440° C. or higher, and the heat resistance is excellent.

Next, the solubility of the bismaleimide (■) of the present invention,
A comparison with N-(4,4°-methylene diphenylene) bismaleimide is shown in Table 3.

Table 3 Solubility of bismaleimide compound (25°C 1% by weight) The solubility of the bismaleimide of the present invention in general-purpose solvents such as dichloromethane and tetrahydrofuran is as follows:
N,N"-(4,4'-methylene diphenylene) bismaleimide is characterized by a high With high boiling points such as N-methylpyrrolidone and N,N-dimethylacetamide, which had to be used with conventional bismaleimides such as N,N'-(4,4'-methylene diphenylene) bismaleimide, It is possible to replace hygroscopic solvents with volatile and low boiling point solvents.Therefore, the problem of residual solvents that cause performance deterioration of laminates and molded products can be reduced, and it is also favorable for improving workability and saving energy. In addition, by utilizing these characteristics, it can be used in a wide range of industrial fields as a material that requires unique functions such as electrical edging materials, heat-resistant adhesives, and coating pads. have.

Next, a method for producing the compound of the present invention will be described.

The diamine used as a raw material is a compound represented by the general formula (IT), and includes 2.2-bis(4-(3-aminophenoquine)phenyl]propane, 2.2-bis[3-
Methyl-4-(3-aminophenoxy)phenyl]propane, 2,2-bis[3,5-dimethyl-4-(3-aminophenoxy)-2-(4-(3-aminophenoxy)phenyl]propane, 2-(3,5-dimethyl-
4-(3-aminophenoxy)phenyl) -2-(4
-(3-aminophenoxy)phenyl]propane, 2-
(3-methyl-4-(3-aminophenoxy)phenyl)-2-(4-(3-aminophenoxy)phenyl)
Such as propane.

As mentioned above, these diamines have the corresponding 4,
It can be industrially advantageously produced in high yield by condensing 4[deg.]-bisphenols and m-dinitrobenzene in an aprotic polar solvent in the presence of a base, followed by reduction.

The method for producing the compound of the present invention is not particularly limited, but usually, in the first step, a diamine represented by the general formula (■) and maleic acid anhydride are reacted in an organic solvent, and the general formula (〆) (in the formula, R
5-R4 has the same meaning as in general formula (1)) is produced. Known methods are used for this purpose.

The reaction solvents usually used are halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethane, and trichloroethylene, ketones such as acetone, methyl ethyl ketone, cyclohexanone, and diisopropyl ketone, ethers, ethers such as tetrahydrofuran, dioxane, and methyl cellosolve, benzene, Aromatic compounds such as toluene and chlorohenzene, acetonitrile, N, N
-Aprotic polar solvents such as -dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, 1-methyl-2-pyrrolidinone, and 1,3-dimethyl-2-imidabridinone.

The amount of these solvents used is not particularly limited, but usually 1 to 10 times the weight of the raw materials is sufficient.

Next, in the second step, bismaleamic acid is cyclized and dehydrated to produce bismaleimide represented by general formula (1). As this method, a known method is used in which acetic anhydride is used as a dehydrating agent and the reaction is carried out in an organic solvent in the presence of a base and a catalyst (Japanese Patent Publications No. 46-23250, No. 49-40231, No. 59-Sho. 52660)
.

At this time, there is no particular upper limit to the amount of acetic anhydride used, but it is usually in the range of 2 to 4 times the molar amount of bismaleamic acid.

The catalysts used are oxides of alkaline earth metals, iron (I
carbonates, sulfates, phosphates, acetates of nickel (■), manganese (■ and ■), nickel (■ and ■) or cobalt (II and ■), especially Preferred are nickel acetate (n), cobalt acetate (U), and magnesium oxide. These catalysts are sufficiently expensive when used alone, but two or more types may be used in combination.

The amount used is 5X10-' to 0.1 for bismaleamic acid.
It is in the molar range.

The base used is specifically sodium acetate, potassium acetate, trimethylamine, triethylamine, tributylamine and the like. The amount used is in the range of 0.05 to 1.1 mol based on bismaleamic acid.

There are no particular limitations on the embodiments of the method of the present invention, and the intermediate bismaleamic acid produced in the first step does not necessarily need to be isolated in order to produce bismaleimide.
The second stage cyclization and dehydration reaction can also be carried out in the same solvent as it is. At this time, the reaction temperature is in the range of 20 to 80°C, and the reaction time is in the range of 0.5 to 9 hours.

After the reaction is completed, the precipitated crystals are filtered or discharged into water or methanol to obtain crystals of the desired product.

(Functions and Effects) The compound of the present invention is a solvent that has a characteristic of higher solubility in organic solvents than conventional bismaleimides such as N,N''-(4,4'-methylene diphenylene) bismaleimide. It is a soluble bismaleimide.By utilizing this feature, it is possible to solve the problem of residual solvents that cause deterioration of laminates and molded products, and improve work efficiency.Furthermore, due to the molecular structure, Expected to improve flexibility.

Therefore, it has a wide range of uses as a material that requires a unique function, such as electrical insulation materials, heat-resistant adhesives, and paints.

(Example) Hereinafter, the method of the present invention will be explained in more detail using Examples.

Example 1 A reaction flask equipped with a stirrer and a thermometer was charged with 10.8 g (0.11 mol) of maleic anhydride and 32 g of acetone and dissolved. Add to this 20.5 g of 2,2-bisC4-<3-aminophenoxy)phenyl]propane (0,
A solution of 0.05 mol) dissolved in 41 g of acetone was added dropwise at room temperature, and the mixture was further stirred at 23-27°C for 3 hours. After the reaction, the formed crystals were filtered, washed with acetone, and dried to obtain bismaleimide acid as yellow crystals.

Yield 29.7g (yield 98.0χ), a+p169~1
Elemental analysis at 71°C (%) CII N Analysis value 69.19 4.73 4.59IR (K[1
r, cm-'): 3280 and 3220 (Nl+),
1700 (Carbokin Rua 5), 1580 and 1550
(Amide bond) MS (FD method): m/e 60B (M+2), 51
0.491.411 38 g of bismaleamide M thus obtained are suspended in 92 g of acetone, 3 g of triethylamine are added and stirred for 30 minutes at room temperature.

After adding 13 g of magnesium (II) oxide and 200,013 g of cobalt acetate ([1).4H, 16 g of acetic anhydride was added dropwise at 25° C. over 30 minutes, and the mixture was further stirred for 4 hours.

After the reaction is complete, the generated crystals are filtered and washed with methanol.
It was dried under reduced pressure at 40°C to obtain bismaleimide (III) as yellow crystals.

Yield: 30g (yield: 83.9X), mp: 161~
164℃ elemental analysis (%) C11N analysis value 74.14 4.27 4.84IR (KB
r, cm-'): 1775 and 1715 (imide bond)
, 1255 (ether bond) MS (FDnA, m/e): 571 (M+1) 5χ Weight loss temperature and solubility are as shown in Tables 1 and 2.

Example 2 A reaction flask equipped with a stirrer and a thermometer is charged with 21.6 g (0.22 mol) of maleic anhydride and 64 g of acetone and dissolved. To this was added 41 g of 2,2-bisC4-(3-aminophenoquine)phenyl]propane (0.1
A solution prepared by dissolving mol.

After adding 4.7 g of triethylamine to this, 30 g of triethylamine was added at room temperature.
Stir for a minute. Magnesium oxide (II) 0.21g
, cobalt (II) acetate. After adding 48200.021 g, 25.3 g of acetic anhydride was added dropwise at room temperature over 30 minutes, and the mixture was further stirred for 4 hours. After the reaction is complete, methanol 1
50g was added dropwise, the crystals were filtered through IIM, and washed with methanol.
It was dried under reduced pressure at 40°C to obtain bismaleimide (III) as pale yellow crystals. yield) 55.1g (yield 96.5
χ) Example 3 In a reaction flask equipped with a stirrer and a thermometer, 2.1 lllg (0,022 mol) of maleic anhydride and 6.1 g (0,022 mol) of acetone were added.
Charge 5g and dissolve. To this, add 4.38 g (0.01 mol) of 2,2-bis[3-methyl-4-(3-aminophenoxy)phenyl]propane to 22 g of acetone? 8
The dissolved solution was added dropwise at room temperature, and the mixture was further stirred at 23-27°C for 3 hours. After the reaction was completed, the resulting crystals were filtered, washed with acetone, and dried to obtain bismaleamic acid as pale yellow crystals.

Yield: ff16.2g (yield: 97.6%), mp 1
56-159℃ Elemental analysis (%) CII N IR (KBr, am-'): 1720Sh (COz
ll group), +700 (amide bond), 1250
(Ether bond) 2.8 g of bismaleamic acid thus obtained is suspended in 8.48 g of acetone, 0.21 g of triethylamine is added, and the mixture is stirred at room temperature for 30 minutes.

After adding 0.009 g of magnesium (II) oxide and 200,009 g of cobalt acetate (n) 4H, 1.14 g of acetic anhydride was added dropwise at 25°C over 30 minutes, and
Stir for an hour. After the reaction is completed, the reaction solution is added dropwise to 300 ml of water while stirring. The generated crystals were filtered, washed with water, and dried to obtain bismaleimide (rV) as yellow crystals.

Yield 2.4g (yield 90.9%) This crystal was recrystallized from acetone to obtain a pure product.

m p: 143.5-145.8°C Elemental analysis (%) CII N Analysis value 73.86 5.02 4.66IR
(Kllr, cm-'): 1785 and 1705 (imide bond), 1240 (ether bond) 5χ Weight loss temperature (in air, 'C): 449 Example 4 Anhydrous maleic acid was added to a reaction flask equipped with a stirrer and a thermometer. 2.16 g (0,022 mol) of acid and 6.5 g of acetone
Charge and dissolve. A solution of 4.67 g (0.01 mol) of 2,2-bis[3,5-dimethyl-4-(3-aminophenoxy)phenyl]propane dissolved in 19 g of acetone was added dropwise to this in one chamber, and then 3 at 23-27°C
After stirring the reaction for an hour, pour the reaction solution into 300ml of water! ! Add dropwise while stirring. After washing the formed crystals with water,
After drying, bismaleimide acid was obtained as pale yellow crystals.

Yield 6.6g (yield 98.5%), m p 207
．． 5-209℃ elemental analysis (%) CII N analysis value 70.67 6.02 4.25IR (KB
r, cm-'): 3400 (Nll), 1720sh
(carboxyl group), 1705 (amide bond), 1245 (ether bond) 2.6 g of bismaleamic acid thus obtained was suspended in 7.8 g of acetone, and triethylamine 0.19
g and stirred for 30 minutes at room temperature.

After adding 0.008 g of magnesium (II) oxide and 411□00.0008 g of cobalt (II) acetate, 1.04 g of acetic anhydride was added dropwise over 30 minutes at 25°C, and the mixture was further stirred for 4 hours. After the reaction is complete, add 300% water to the reaction solution.
Add dropwise to m1 while stirring. The generated crystals were filtered, washed with water, and dried to obtain bismaleimide (V) as pale yellow crystals.

Yield 2.3g (yield 93.5%) This crystal was recrystallized from acetone to obtain a pure product.

m p: 230-233'C Elemental analysis (%) CII N Analysis value 74.49 5.34 4.38IR (K
Br, cm): 1765sh and 1705 (imide bond) 1235 (ether bond) 2.16g (0,022mol) and 6.5g acetone
Charge and dissolve. To this, 2-[3,5-dimethyl-
4-(3-aminophenoxy)phenyl)-2-(4-
(3-aminophenoxy)phenyl]propane 4.38
A solution of g (0.01 mol) dissolved in 12 g of acetone is added dropwise at room temperature, and the mixture is further stirred at 23-27° C. for 3 hours.

After the reaction is completed, the reaction solution is added dropwise to 300 m of water with stirring. The generated crystals were filtered, washed with acetone, and dried to obtain bismaleamic acid as pale yellow crystals.

Yield 6.3g (yield 99.4%), m p 143~
146℃ elemental analysis (%) CII N analysis value 69.97 5.37 4.311R
r, c+n-'): 1710 (carboxyl u")
, 1695 (amide bond), 1240 (ether bond) 2.5 g of bismaleamic acid thus obtained was mixed with 5 g of acetone, and 0.1 g of triethylamine was added.
Add 9g and stir for 30 minutes at room temperature.

After adding 0.08 g of magnesium oxide (II) and 411200.0008 g of cobalt acetate (■), 1.0 g of acetic anhydride was added. Ig was added dropwise at 25°C over 30 minutes, and then
Stir for an hour.

After the reaction is completed, the reaction solution is added dropwise to 300 ml of water while stirring. The formed crystals were filtered, washed with water, and then dried to obtain bismaleimide (VI) as amber crystals.

Revenue! It2.2g (yield 93.3%) This crystal was recrystallized from acetone/ethanol,
I got a pure product. m p: 151.2-154.4°C Elemental analysis (%) CII N IR (KBr, cm-'): 1785 and 1705 (
Imide bond) 1240 (ether bond) 5χ Weight loss temperature (in air, °C): 440 Patent applicant Mitsui Toatsu Chemical Co., Ltd. Procedural Supervisor (spontaneous) February 2, 1988 Commissioner of the Japan Patent Office Black 1) Yu Akira 1, Indication of the case 1985 Patent Application No. 292881 2 Name of the invention Bismaleimide and its manufacturing method 3 Relationship with the person making the amendment Patent applicant address 3-2 Kasumigaseki, Chiyoda-ku, Tokyo No. 5 name (31
2) Mitsui Toatsu Chemical Co., Ltd. 4, “Detailed Description of the Invention” column of the amended statement of contents 1) Change “poamine modification” on page 3, line 10 of the specification to “
Corrected to ``polyamine denatured''.

2) Similarly, on page 4, line 8, "adjustment" is corrected to "preparation."

3) Similarly, on page 4, line 10, "prepreg" is corrected to "prepreg".

4) Similarly, on page 5, line 13, "the inventors furthermore said the above" was corrected to "the inventors further said the above".

5) Similarly, the glue in Table 1 on page 7 is r207, 5~
209" should be corrected to "230-233."

6) Similarly, rN, 1l-(4,4
Correct "-methylene" to rN,N'-(4,4°-methylene.)

7) Similarly, in Table 3 on page 8, "rN, N-(4,4-methylene" is corrected to "rN, N'-(4,4°-methylene").

8) Same (, page 9, line 4, correct "low boiling point" to "J" for low boiling point solvent.

9) Similarly, on page 9, lines 18-20, [2,2-bis[3゜5-dimethyl-4-(3-aminophenoxy L2
- [4-(3-aminophenoxy)phenyl]propane" is replaced with "2,2-bis[3,5-dimethyl-
4-(3-aminophenoxy)phenyl]propane".

10) Similarly, on page 10, line 9, the phrase ``with high purity'' should be corrected to ``with high yield and high purity.''

11) Similarly, on page 12, line 11, "expensive" is corrected to "effect."

12) Similarly, on page 12, line 15, ``The base used is j'' is corrected to ``The base used is an alkali metal acetate or a tertiary amine.''

13) Similarly, on page 13, line 12, "represented by bismaleimide" is corrected to "represented by bismaleimide."

14) Similarly, on page 13, line 13, "compared to organic solvents" is corrected to "compared to general-purpose organic solvents."

15) Similarly, on page 13, line 18, "I can expect improvement" should be corrected to "I can also expect improvement."

! 6) Similarly, on page 14, line 13, "bismaleimide acid" is corrected to rbismaleimide acid J.

17) Similarly, on page 15, line 8, "stir for an additional 4 hours" is corrected to "stir for an additional 4 hours."

18) Similarly, on page 15, line 11, "Yellow crystal" is corrected to "Pale yellow crystal."

19) Similarly, on page 16, line 16, “(yield 96.5
χ)” is corrected to “(yield 96.5χ)”.

20) Similarly, page 17, line 7 [(yield 97.6χ
)” is corrected to “(yield 97.6χ)”.

21) Similarly, page 17, bottom 3rd line, ro, o09gJ
is corrected to ``0.0009g J.''

22) Similarly, on page 19, line 4, "bismaleimide acid" is corrected to "bismaleamic acid."

23) Similarly, page 21, bottom 6th line, ro, 08g J
is corrected to "0.008g".

that's all

Claims (1)

[Claims] 1) General formula (I) ▲Mathematical formula, chemical formula, table, etc.▼(I) (In the formula, R_1 to R_4 represent hydrogen or a lower alkyl group, and may be the same or different from each other. Bismaleimide represented by 2) General formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (II) (In the formula, R_1 to R_4 represent hydrogen or lower alkyl groups and may be the same or different from each other.) General formula (I) characterized by reacting a diamine having an ether bond with maleic anhydride ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1 to R_4 are general formula (I) A method for producing bismaleimide, which has the same meaning as ).