JPH01279926A - Modified bismaleimide resin and its production - Google Patents

Abstract

PURPOSE: To improve performance such as pot life, water absorbing rate, heat resistance, strength and elastic rate by producing a polymer with a structure of coupling a bismaleimide with an aromatic secondary diamine.

CONSTITUTION: The modified bismaleimide resin is a compound denoted in formula I (A is 2-20C divalent group; A' is a divalent group with ≤20C containing at least one aromatic group; R is 1-10C aliphatic group; and n is 1-3). The resin is manufactured with the Michael addition reaction of a bismaleimide denoted in formula II (A is the same as above; B is divalent group of 2-6C containing a carbon double bond) such as N,N-4,4'-diphenyl methane bismaleimide, and an aromatic secondary diamine such as N,N'-dimethyl-4,4'- diamino diphenyl methane in a mol-ratio of 1.2:10:1, preferably 1.5:3:1 at a temperature of 100-150°C.

COPYRIGHT: (C)1989,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel modified bismaleimide resin and a method for producing the same.

[Prior art]

Conventionally, reactive oligomers are low molecular weight substances that contain moieties that exhibit the properties of completely cured resins, and have excellent thermal stability, but they cannot be used as structural materials. It was introduced to improve the problem of conventional heat-resistant resins, which are extremely low processability.

All molding of bismaleimide resin is done in the oligomer state, and the skeleton structure and molecular weight of this oligomer have a great influence on the thermal and mechanical properties when cured, and also have a great influence on the molding conditions.

Bismaleimide resin has excellent thermal oxidation stability and high-temperature wet strength (hot-weLsLrengLh), maintains excellent physical properties such as dimensional stability and inherent flame retardancy, is relatively cheap, and is easy to process. Recently, advanced composite materials have been used in advanced technology industries such as aviation, space, and defense industries.
composite material) base material (ia
In addition to being in the spotlight as a material (trlx resin), it is also used as a base material for composite materials in the electronics industry, automobile industry, and other general industrial fields where heat resistance is required.

Generally, resins made by polymerizing only bismaleimide itself have a high cross linking d4 density.
en-city), the second-order transition temperature (Tg)
has very high heat resistance above 300℃, but on the other hand, it is brittle (
brlttlc) as well as N-methyl-
It has the disadvantage of being soluble only in high boiling point polar solvents such as 2-pyrrolidone (boiling point: 202°C) and N,N'-dimethylformamide (boiling point: 153°C).

When carbon fibers are impregnated with such high boiling point polar solvents to make prepregs, it is difficult to remove these solvents, resulting in a high amount of residual solvents, and this can be used for lamination. When made into a board, the residual solvent acts as a plasticizer and evaporates when used at high temperatures, causing a decline in the physical properties of the resin.

Kerimid 601 (Kerlmld 601, manufactured by France Longplan), a typical bismaleimide resin currently on the market (reference: U.S. Patent No. 3.562)
．． No. 223) is N of bismaleimide.

It is synthesized by Michael addition reaction of N'-4,4'-diphenylmethane bismaleimide and 4,4'-diaminodiphenylmethane, a primary diamine, and has a molecular weight of about 1000, and is terminally treated with a maleimide group. It is a sexual oligomer. U.S. Patent No. 3,562,22
According to No. 3, the molecular weight of the oligomer is increased by an addition reaction between bismaleimide and a primary diamine (chain ex
tension) and as a result, when cured, the crosslinking density is lowered, so the heat resistance is slightly increased, but the toughness (
toughness).

At this time, if a large amount of primary diamine is used, it will easily collapse at high temperatures and lose its value as a heat-resistant resin.

In the above-mentioned US patent, an appropriate ratio of bismaleimide and primary diamine (molar ratio 2.5:1) was discovered, the mutually opposing properties mentioned above were overcome, and the product was successfully commercialized.

However, chelimide 601, which is the object of the above patent,
In order to produce the resin, N-methyl-2-pyrrolidone, which is a high-boiling polar solvent, must be used, so it has limited applications in the electronics industry, such as as a base material for multilayer printed circuit boards. Its use is only possible in

The reason for this is that when bismaleimide and primary diamine undergo Michael addition reaction at low temperature to form a low molecular weight oligomer and then cure at high temperature, the double bond of bismaleimide at the end undergoes self-polymerization reaction, that is, homopolymerization. This is due to the fact that not only a crosslinking bond is formed by the reaction, but also a crosslinking reaction by diamine occurs at the same time, resulting in a high crosslinking density.

In order to eliminate the above-mentioned drawbacks, the present inventors conducted extensive research and examination and found that when a Michael addition reaction is performed at low temperature using bismaleimide and an aromatic secondary diamine, cross-linking occurs during the reaction. The disadvantage of rapidly increasing viscosity is eliminated, and the pot life can be greatly improved.Furthermore, by using secondary diamine instead of primary diamine, all the polar sites of the amine are removed. The present invention was completed based on the discovery that not only the water-absorbing skewer could be significantly improved by the blocking effect, but also various physical properties such as heat resistance, strength, and elasticity could be improved.

In the above, pot life refers to the state in which curing does not occur when a curing agent is mixed with liquid thermosetting resin.
Not only is it easier to cast complex patterns with a long pot life, but composite materials do not require the use of high boiling point polar solvents or electrolytic solvents. High temperature melting process (hot
-selL process).

[Object and structure of the invention]

A first object of the present invention is to provide a modified bismaleimide resin produced by subjecting bismaleimide and aromatic secondary diamine to a Michael addition reaction at a low temperature.

A 20th object of the present invention is to provide a method for producing a modified bismaleimide resin of the above general formula (1), which is characterized by subjecting bismaleimide and an aromatic secondary diamine to a Michael addition reaction at 100 to 150°C. be.

Thus, the present invention combines bismaleimide and aromatic secondary diamine (
Michael addition reaction (secondary lamne)
The present invention relates to a modified bismaleimide oligomer resin represented by the following general formula (I) obtained by subjecting the present invention to a method for producing the same.

In the above formula, n is an integer from 2 to 3, and A is a divalent group having 2 to 20 carbon atoms (dl
1A' represents a divalent group containing at least one aromatic group and having 20 or less carbon atoms, and R represents an aliphatic group containing 1 to 10 carbon atoms. show.

As mentioned above, the bismaleimide oligomer resin according to the present invention not only has excellent heat resistance and elastic modulus, but also has 1.
When producing prepregs using a high temperature melt process, there are economic and processing advantages associated with the absence of solvents, as well as the fact that no volatiles are generated and therefore the physical properties of the final composite are not compromised. has.

[Detailed description of the invention]

Bismaleimide, which is a starting material used in the present invention, is a compound represented by the following general formula (n).

In the above formula, B represents a 2 to 6 group containing carbon-carbon 2 type packing, and A represents a divalent group having 2 to 20 carbon atoms.

Examples of the above compounds include N,N'-1,3-phenylenebismaleimide, N,N'-4,4'-diphenylmethanebismaleimide, N,N'-4゜4'-
Diphenyl ether bismaleimide, NIN'-4,4
'-diphenylsulfone bismaleimide, N, N'
-3,4'-diphenylsulfone bismaleimide,
N,N'-4,4'-dicyclohexylmethane bismaleimide, N,N'-4゜4'-dimethylenecyclohexane bismaleimide, N,N'-4,4'
-diphenylcyclohexane bismaleimide, N, N'
-1,3-zyrylenebismaleimide, 2.4-bismaleimidotoluene, 2.6-bismaleimidotoluene and the like.

The aromatic secondary diamine used in the present invention is a compound represented by the following general formula (III).

RR In the above formula, A' represents at least two groups containing at least one aromatic group and having 20 or less carbon atoms, and R is an aliphatic group having 1 to 10 carbon atoms.

Examples of the above compound (III) include N,N'-dimethyl-4,4'-diaminodiphenylmethane, NIN
'-Methylethyl-4,4'-diaminodiphenylmethane, N,N'-dimethyl-4,4'-diaminodiphenylsulfone, N,N'-dimethyl-4,4'
-diaminodiphenyl ether, N-(1,3-dimethylbutyl)-N'-phenyl-varophenyl diamine, N-isopropyl-N'-phenyl-varaphenyl diamine, NIN'-diphenyl-paraphenylene diamine, NIN'-dimethyl -2,4-diaminotoluene, N+N' -diaminotoluene, N, N
'-dimethyl-2,6-diaminotoluene, N,N
'-dicyclohexyl-4,4'-diaminodiphenylmethane and the like.

On the other hand, the amount of bismaleimide and aromatic secondary diamine to be used is indicated by the number of moles of bismaleimide and the number of moles of secondary diamine, and the ratio thereof is 1.2:1 to 10:1, preferably 1.5:1 to The range is 3:1.

If the amount of secondary diamine is used above the above range, the crosslinking density will be low and the heat resistance will be poor; if it is used below the above range, the heat resistance will be high but the toughness will be low.

Additionally, cure accelerators can be used as a method to lower cure temperatures, shorten cure times, and improve process drying and cycle times; in this invention, ionic (Ionlc)
catalyst or free radical
) a catalyst can be used.

The amount of the catalyst used is generally 0.1 based on the total reaction mixture.
-10% by weight, preferably 0.1-5.0% by weight, based on the total reaction mixture.

Ionic catalysts suitable for the present invention include tertiary amine compounds such as diazabicyclooxtane, imidazole, 2-methylimidazole, 2-phenylimidazole, 4-methyl-2-phenylimidazole, and benzene. Examples include imidazole derivatives such as imidazole, and when these are used, the fracture toughness value of the base metal
ess) can be improved.

Free radical catalysts suitable for use include organic peroxides such as dicumyl peroxide (DCP), t-butyl-cumyl peroxide, 2,5-di(butylperoxy)hexane, and t-butylperoxybenzoate. In addition to oxides, azobisisobutyronitrile (AIB
N), hydroperoxide, etc., and the amount used is preferably in the range of 0.1 to 560% by weight.

Further, a mixed catalyst in which an ionic catalyst and a free radical catalyst are appropriately blended can be used, and in this case, the desirable ratio of the ionic catalyst to the free radical catalyst is 2=1 to 1:2 in terms of mu ratio.

〔Example〕

The present invention will be explained below based on Examples and Comparative Examples.

In the examples, the test results used were based on the following criteria.

Flexural strength: ASTM D 790-71 Fracture toughness: ASTM E 399-79 Moisture absorption rate: AST
M D 570-71 Dielectric Strength: ASTM D
150-69 T Example 1 N to a 30 flask fitted with a stirrer and thermometer.

N'-dimethyl-4,4'-diaminodiphenylmethane (1 mol) and N,N-4,4'-diphenylmethane bismaleimide (2,501) were added.

Next, the temperature was maintained at 130°C and the reaction was carried out for about 10 minutes with stirring to confirm that it had become a clear solution.The solution was then poured into an aluminum dish, cooled to room temperature, and crushed in a ball to form a yellow-brown glossy solution. Get the powder.

This is called RM S (Rheosetrlc Mecha
nical 5pectr.

After pouring into a parallel plate using Model 605 and trimming (Tri-mming), curing at a constant temperature of 130°C in dynamic mode, measuring the viscosity over time, and potting. I analyzed my life.

The results are shown in Table 1.

Comparative Example 1 9.5 g of 4.4'-diaminodiphenylmethane (1
■After maintaining ol) at 120℃, 42.9g of N,N
'-4,4'-diphenylmethane bismaleimide (
A comparative product was prepared in the same manner as in Example 1, except that 2.5 μ of ) was added and reacted for about 5 minutes, and the results are shown in Table 1.

Comparative Example 2 4.5 g of N,N'-dimethyl-4,4'-diaminodiphenylmethane (0,5 sol) and 3.9 g of 4.
4'-diaminodiphenylmethane (0,5■ol)
After mixing and maintaining at 130 °C, 35.8 g of N, N
'-4,4'-diphenylmethane bismaleimide (
A comparative product was prepared in the same manner as in Example 1, except that 2.5 μol) was added and reacted for about 10 minutes, and the results are shown in Table 1.

As shown in Table 1 above, the resin produced using the aromatic δ group secondary diamine according to the present invention is superior to the resin produced using the primary diamine or the mixture of the primary diamine and the secondary diamine. The viscosity was found to be lower than that of the

Furthermore, it is a well-known fact that the lower the viscosity, the better the moldability.

Example 2 22.6g in a 30 flask equipped with a stirrer and thermometer
4.4'-methylenebis(N-methylaniline) (
MBMA) and heated in an oil bath for 14 minutes.
4,4′ of 107.4sr after already preheating to 0℃
- Add bismaleimidiphenylmethane (BMDM). Next, while maintaining the temperature at 140°C, the reaction was continued for about 10 minutes with stirring, and after confirming that it had become a clear solution, the reaction was continued for about 30 minutes, and a dcg
asslng).

At this time, in some cases, the initial viscosity of the molten mixture after defoaming was measured and shown in Table 2.

This mixture was cast into an aluminum mold (125 mm x 130 m x 65 mm) preheated to 120°C, heated to 200°C within 30 minutes in an air oven, and then heated at this temperature. Hold for about 4 hours and then remove the malt.

Next, secondary curing was performed at 220°C for 15 hours.
re), gradually cooled to room temperature (25°C), prepared test pieces according to each test standard, and then mechanically
Thermal properties were measured and the results are shown in Table 3.

Bending strength test is bending test IPk quasi ASTM D790-7
After cutting the test piece to meet one standard, the span (s
pan) Measured value at room temperature (25℃) at 50os and 2
The values measured after heating at 50°C for 1050 hours are shown.

Example 3-4 As shown in Table 2, only the molar ratio of BMDM and MBMA was different, and after carrying out the same method as in Example 2, a test piece was manufactured and the physical property values determined by n1 are shown in Table 3. Indicated.

Example 5-12 As shown in Table 2, the test was carried out under the same conditions and test method as in Example 2, except that only the type of catalyst was changed.

Each catalyst was always added after the reaction mixture was completely defoamed, and after the catalyst was added, it was easily degassed again.

Table 3 shows the results of physical property measurements.

Example 13-17 As shown in Table 2, N,N'-metaphenylene bismaleimide and N,N'-4,4'-diphenyl ether bismaleimide were used instead of BMDM (Example 13-14) L, the type of secondary diamine is replaced with MBMA by N, N'-methylethyl-diaminodiphenylmethane, N-(1,3-diethylbutyl)-N'-phenyl-paraphenylenediamine, and N.

The same procedure as Example 2 was carried out except that N'-dimethyl-2,4-diaminotoluene was used (Examples 15 to 17).

Table 3 shows the results of physical property measurements.

Note: BMI-1: N,N'-metaphenylene bismaleimide BMI-1: :N,N'-4,4'-diphenyl ether bismaleimide 2nd-A: N,N'-methylethyl-diaminosyphenin Methane 2nd-A ■: N-(1,3-dimethylbutyl)-N'
-Phenyl-bara-phenylenediamine 2nd-A
■: N,N'-dimethyl 2,4-diaminotoluene Example 18 179g of N,N'-diphenylmethane bismaleimide was preheated to 130°C and 45.2g of N,N
The solution was added to '-dimethyl-4,4'-diaminodiphenylmethane, and after confirming that it had become a clear solution while stirring with a stirrer, it was defoamed for about 30 minutes.

This mixed solution is directly used as an impregnating solution for glass fiber cloth in a high temperature melting process without using any additional solvent. The glass fiber cloth was woven into a 3600cj satin type and pre-treated with gamma-aminopropyltriethoxysilane (
It is an E-type glass fiber cloth treated with ``Al100'' (trade name of Union Carbide Company).

This glass fiber cloth was dipped in a mixed solution.
) Ing ) The resin-impregnated fabric is then impregnated with resin to adjust the flow properties for compression molding or autoclave molding.
Preliminary reaction is carried out in an air oven at 0°C for about 10 minutes.

After making 16 test pieces of this with the standard of 150mm x 150III11 each, a laminate plate (Lamlnat
edassembly) -.

The laminate produced in this way is placed between high-gloss body foils and compressed to a pressure of 30 kg/cd for about 1 hour, after which the temperature is gradually increased to 220°C. After removing the malt, the laminate is gradually heated to 250° C. and then post cured for about 24 hours.

After cooling to room temperature, the physical properties measured are as follows.

Resin gold JL: 21% Flexural strength (at span 50mm): Initial; 65.5kg
/- After heating at 250°C for 1050 hours; 58 kg/mj Example 19 The operating conditions and procedures were the same as in Example 2, and the reaction mixture obtained was applied to aluminum malt to form a layer of 10 l thick. Pour and react at 200°C for about 10 minutes.

After cooling to room temperature, the malt is removed and the resulting product is ground in a grinder to give an average particle size of about 80 μm.

The product thus obtained30. was placed in a round n-type malt with a diameter of 75mm and inserted into a press preheated to 200℃, and then pressure was applied to 50kg/℃.

After maintaining this condition for about 1 hour, the malt is removed while still at high temperature, and secondary curing is performed at 220° C. for about 24 hours.

The physical properties measured after cooling were as follows: flexural strength was 15.2 at 25°C.
After heating at 250° C. for 860 hours, the bending strength was 13.1 kg/−.

The electrical properties are shown in Table 4 below.

Table 4

Claims (1)

[Claims] 1. A modified bismaleimide resin represented by the following general formula (I) ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ (I) In the above formula, n is an integer from 1 to 3, and A represents a divalent group containing 2 to 20 carbon atoms, A' is a divalent group containing at least one aromatic group and 20 or less carbon atoms, R is an aliphatic group containing 1 to 10 carbon atoms. 2. Bismaleimide and aromatic secondary diamine from 100 to 1
A method for producing a modified bismaleimide resin represented by the following general formula (I), which comprises carrying out a Michael addition reaction at a temperature of 50°C. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) In the above formula, n is an integer from 1 to 3, A represents a divalent group containing 2 to 20 carbon atoms, and A' is It is a divalent group containing at least one aromatic group and not more than 20 carbon atoms, and R is an aliphatic group containing at least 1 to 10 carbon atoms. 3. In item 2, bismaleimide has the following general formula (I
A method characterized by being a compound represented by I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (II) Here, B represents a divalent group containing a carbon-carbon double bond and 2 to 6 carbon atoms, and A represents 2 It is a divalent group containing 5 to 20 carbon atoms. 4. In the second or third term, bismaleimide is N,
N'-1,3-phenylene bismaleimide, N,N'-
4,4'-diphenylmethane bismaleimide, N,N'
-4,4'-diphenylether bismaleimide, N,N
'-4,4'-diphenylsulfone bismaleimide, N
, N'-3,4'-diphenylsulfone bismaleimide, N,N'-4,4'-dicyclohexylmethane bismaleimide, N,N'-4,4'-dimethylcyclohexane bismaleimide, N,N '-4,4'-diphenylcyclohexane bismaleimide, N,N'-1,3
- A method for producing a bismaleimide resin, characterized in that it is zyrylene bismaleimide, 2,4-bismaleimidotoluene, or 2,6-bismaleimidetoluene. 5. The method according to item 2, wherein the aromatic secondary diamine is a compound represented by the following general formula (III). ▲There are mathematical formulas, chemical formulas, tables, etc.▼(III) Here, A' contains at least one aromatic group, and 2
It is a divalent group containing 0 or less carbon atoms, and R is an aliphatic group containing 1 or more and 10 or less carbon atoms. 6. In item 2 or 5, the aromatic secondary diamine is N,N'-dimethyl-4,4'-diaminodiphenylmethane, N,N'-methylethyl-4,4'-diaminodiphenylmethane, N, N'-dimethyl-4,4'-diaminodiphenylsulfone, N,N'-dimethyl-4,4
'-Diaminodiphenyl ether, N-(1,3-dimethylbutyl)-N'-phenyl-paraphenylenediamine, N-isopropyl-N'-paraphenylenediamine, N,N'-diphenyl-paraphenylenediamine, N
, N'-dimethyl-2,4-diaminotoluene, N,N
'-Dimethyl-2,6-diaminotoluene, N,N'-
A method for producing a bismaleimide resin, characterized in that it is dicyclohexyl-4,4'-diaminodiphenylmethane. 7. The method for producing a bismaleimide resin according to item 2, wherein the weight ratio of bismaleimide and aromatic secondary diamine is 1.2:1 to 10:1. 8. The method for producing a bismaleimide resin according to item 2, characterized in that an ionic catalyst, a free radical catalyst, or a mixed catalyst thereof is used during the Michael addition reaction. 9. In item 8, the ionic catalyst is diazabicyclooxitane, imidazole, 2-methylimidazole, 2
- A method for producing a bismaleimide resin, characterized in that it is phenylimidazole or 4-methyl-2-phenylimidazole. 10. In item 8, the free radical catalyst is di-cumyl peroxide (DCP), t-butyl-cumyl peroxide, 2,5-di(butylperoxy)hexane, t-butylperoxybenzoate, azo A method for producing a bismaleimide resin, characterized in that bisisobutyronitrile (AIBN) and hydroperoxide are used. 11. The method for producing a bismaleimide resin according to item 8, wherein when a mixed catalyst of an ionic catalyst and a free radical catalyst is used, it is used at a weight ratio of 2:1 to 1:2.