JPH0362737B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for producing a bismaleimide resin composition. PRIOR ART Bismaleimide (BMI) resins are a newly developed class of resins that have recently become commercially available.
The BMI resin system has been proven to exhibit excellent high temperature performance for a considerable period of time even at temperatures as high as 450°C. BMI resin systems can be processed in the same equipment as epoxy resins and therefore can be easily used in industrial practice. For these reasons,
The BMI resin system is considered to be an ideal raw material for producing modern high-performance composite matrices, which must be highly thermally stable and tough. However, it is currently available
BMI resin system has excellent high temperature performance, but
It has two major drawbacks: poor toughness and poor processability. A method often employed to improve the toughness of thermoset resins is to add reactive liquid rubber during the production of thermoset resins. This method is not applicable to the BMI resin system contemplated by the present invention. This is because the high temperature properties and mechanical performance of this type of BMI resin system are adversely affected by the addition of rubber, which has low stability and toughness. German Patent No. 810,430, granted to HD Stenzenberger in 1981, makes solvent-based prepregs by dissolving high-performance thermoplastics and BMI or epoxy resins in low-boiling solvents, such as dichloromethane. discloses a method for obtaining a curable resin varnish. It has been reported that products obtained from the Stenzenberger patent resins, for example in the form of matrices or laminates, exhibit good high temperature properties. However, due to some degree of phase separation between the high performance thermoplastic and the added BMI or epoxy system after evaporation of the solvent,
The mechanical performance of the resulting product is not significantly improved.
Furthermore, the use of solvents results in environmental pollution and requires additional costs for its implementation. Furthermore, the quality and reproducibility of Stenzenberger products, like other solvent-based prepregs, is always poorer than that of hotmelt prepregs, and therefore Stenzenberger's method produces high-quality composite products. It is not suitable for As can be seen from the above discussion, the industry is striving to: (1) improve the toughness of BMI resins while maintaining their mechanical performance and high temperature properties; and (2) improve the toughness of BMI resins, e.g. To provide a hot melt type resin system which can be processed by a prepreg apparatus to produce a desired prepreg, or processed by injection molding and resin transfer molding to produce a final product. Cleve B. Backknel and Ivana K. Partridge, in British Polymer Journal, Volume 15 (March 1983), describe polyether-sulfone (RES, a type of high-performance thermoplastic). discloses a method for improving the toughness of epoxy resins by dissolving them in low molecular weight epoxy resins and then incorporating the resulting mixture into the main epoxy resin system. However, epoxy resin has poorer high-temperature properties than BMI resin, so if epoxy resin is used as a solvent,
The high temperature properties of the BMI resin would be adversely affected, making this method impractical. Furthermore, attempts have been made to add fine powder of high-temperature performance resin plastics to BMI resin as a filler to improve its toughness. This has also failed due to poor compatibility and interfacial problems between the thermoplastic and BMI resin. Early BMI resin systems were, for example, Cherimid 601 supplied by Ron Poulenc of France.
(Kerimid 601) was used. Such manufactured BMI types do not have satisfactory high temperature properties. In 1985, Ciba-Geigy introduced a diallyl compound (i.e., O,O'-diallylbisphenol A) and a BMI resin (i.e.,
We have developed a copolymer with 4,4'-bismaleimide-diphenylmethane). This method involves dissolving the BMI resin in a diallyl compound to form a hot melt liquid, and increasing the temperature to bond the allyl group (C=C-C-) and the carbon double bond in the BMI resin.

It consists of curing the BMI resin by initiating an "ene" reaction between the formula and then further increasing the temperature to carry out the Diels-Alder reaction. The resulting resin matrix was reported to have higher toughness and improved thermal stability. However, the toughness achieved is still insufficient for severe applications, such as for example in aircraft applications, and requires further improvement. [Problem to be Solved by the Invention] Therefore, it is an object of the present invention to provide a composite material which exhibits excellent mechanical performance and high temperature properties at high temperatures and which can also be used in severe applications such as aircraft parts. The object of the present invention is to provide a bismaleimide resin composition that can be cured to a tough and thermally stable matrix for the purpose of the present invention. Another object of the invention is to produce bismaleimides which can be produced in the hotmelt state and cured to tough and thermostable matrices for composite materials which can be further processed in hotmelt operations without the use of harmful solvents. The objective is to provide a series of resins. [Means for Solving the Problems] In a broad sense, the present invention encompasses a method for producing a bismaleimide resin composition that can be cured to a tough and thermally stable matrix for composite materials, and the method includes: Formula with number average molecular weight of 50000 polyether-imide with a number average molecular weight of 3000 to 50000 A high performance thermoplastic selected from the group consisting of polyether-sulfones. [wherein A and B independently represent hydroxy or hydrogen, and X is 2,2-propanediyl, oxy, sulfonyl, sulfinyl, methylene, thio, difluoromethylene, or , where Y is 2,2-propanediyl,
oxy, sulfonyl, sulfinyl, methylene, thio or difluoromethylene] at a first dissolution temperature of 100 to 240°C to form a first mixture; [wherein R represents methylene, 2,2-propanediyl, difluoromethylene, oxy, thio, sulfinyl or sulfonyl] A bismaleimide resin selected from the group consisting of the following compounds is added to the first mixture at a concentration of 100 to 170%. It is characterized by obtaining a desired resin composition by melting at ℃. The as-produced curable resin composition is in a hot melt state and can be further processed in hot melt type operations without the use of solvents. BRIEF DESCRIPTION OF THE DRAWINGS While it is particularly pointed out and distinctly defined that this application is considered an invention, the present invention will now be described in detail along with examples for a better understanding thereof. Diallyl compounds are known to be thermally stable at high temperatures. Furthermore, diallyl compounds are
It is an excellent reactive diluent for BMI resins in that it undergoes "ene" reactions and Diels-Alder reactions on the double bonds of BMI resins, and is therefore not commonly required in conventional methods. For example, n-methylpyrrolidone (NMP) and dimethylformamide (DMF)
The need to use solvents such as Additionally, high performance thermoplastics are known to have excellent high temperature properties. For example, most high performance thermoplastic plastics have a
Will not decompose under high temperatures of ~300℃. Based on the above idea, the present invention relates to a specific method of incorporating these features into BMI resin systems in order to overcome the drawbacks of conventional resin systems. For example, O,
Diallyl compounds such as O′-diallylbisphenol-A can be used, for example, in polyether-imide (PEI) and polyether-sulfone (PES).
It is anticipated that curable compositions for matrix materials that can dissolve high performance thermoplastic plastics such as BMI resins and that are satisfactory in terms of toughness and high temperature properties can be obtained by dissolving them in the resulting mixture. I pinned it down outside. The present invention provides a method for producing a bismaleimide resin composition that can be cured to a tough and thermally stable matrix for composite materials. Each individual element of the invention will be described in detail below. Bismaleimide (BMI) resin Kerimid 601 (Kerimid 601 from Ron-Poulenc)
601) and boots - Technochemy's Compimide 751 and Compimide 795
Many commercially available BMIs include (Compimide 795)
Resin is present. The BMI resin suitable in the present invention has the formula: [wherein R represents methylene, 2,2-propanediyl, difluoromethylene, oxy, thio, sulfinyl, or sulfone]. The most preferred BMI resin is the above compound in which R represents methylene, namely 4,4'-bismaleimido-diphenylmethane (MDAB). The composition produced by the method of the present invention has between 20 and 80
Parts by weight of bismaleimide resin, preferably 30 to 70 parts by weight, particularly preferably 45 to 60 parts by weight. Diallyl Compounds Diallyl compounds suitable for use in the present invention are 5292B available from Ciba-Geigy, TM121 available from Boots-Technochemy, or TM121 available from Boots-Technochemy.
Includes TM123. These product names are based on the formula: [wherein A and B independently represent hydroxy or hydrogen, R is 2,2-propanediyl, oxy, sulfonyl, sulfinyl, methylene, thio, difluoromethylene, or wherein Y is 2,2-propanediyl, oxy, sulfonyl, sulfinyl, methylene, thio or difluoromethylene]. The most preferred diallyl compound is O,O'-diallylbisphenol A (DABA). The composition produced by the method of the present invention has between 20 and 80
It contains parts by weight of diallyl compound, more preferably 30 to 70 parts by weight, particularly preferably 35 to 55 parts by weight. High Performance Thermoplastics (HPTP) The term "high performance thermoplastics" is used herein to mean thermoplastics that can be used at temperatures above 150° C. for significant periods of time. contemplated by the present invention
NPTP has a number average molecular weight of 3000 to 50000. Formula: polyether-imide (PEI) and 3000 ~
Formula with number average molecular weight of 50000: polyether-sulfone (PES).
One commercially available PEI resin is Ultem 1000, available from General Electric Company.
(Ultem 1000) and one commercially available PES resin is 5003P available from ICI PLC. The composition produced by the method of the present invention has 0
30 parts by weight, preferably 2 to 25 parts by weight, particularly preferably 5 to 20 parts by weight of the above-mentioned high performance thermoplastic plastic. The weight ratio of HPTP to BMI resin in the resin composition produced by the method of the invention is preferably 1:100 to 1:1. Method In the method of the present invention, REI or PES is added to a diallyl compound in a desired ratio at 100 to 240°C.
Melt preferably at a temperature of 120-200°C, in which case
Stir the mixture until the PEI or PES is completely dissolved. This process takes about 2-6 hours. It has been found that the solubility percentage (ie, the % of PEI or PES dissolved per unit weight of diallyl compound) can be higher than 100%. Then, heat the resulting mixture of BMI resin at 100-200℃, preferably
Dissolve while stirring at a temperature of 140-160°C for about 30 minutes. The resin composition produced by the method of the present invention is
It is in a hot melt state that can be further processed. The method of the invention does not use solvents. This is considered to be one of the improved features of the present invention. Applications The curable compositions produced by the method of the invention can then be used for processing, such as casting and lamination. This curable composition can be cured at temperatures between 150 and 250°C depending on the composition ratio and degree of cure required. This curing can be terminated prematurely to obtain a B-stage prepreg for further processing, or it can be advanced further to obtain a C-stage product in the desired shape. Since the resin composition produced according to the present invention is in a hot melt state,
Almost any conventional hot melt type operation can be used. Since the reproducibility and processability of hot-melt resin compositions is always better than that of solvent-based compositions, the present invention provides an improved product. Any method for curing a hot melt curable resin composition can be used. Typical methods include injection molding, resin transfer molding and pre-impregnation. The curable compositions of the present invention can be used, for example, to make structural articles such as high-performance aircraft parts. Advantages Diallyl compounds alone exhibit excellent thermal stability. The instantaneous polymerization temperature of is generally higher than 250°C. Furthermore, their chemical structure is similar to that of PEI or PES, so that they are
Highly miscible with It was found that at 100 DEG -240 DEG C., the dissolution percentage (ie the % of PEI or PES dissolved per unit weight of diallyl compound) was higher than 100%. Due to the above special properties, diallyl compounds act as excellent media between PEI or PES and bismaleide resins.
Based on this method, the present invention produces a resin composition by dissolving the BMI resin system in a mixture of a diallyl compound and PEI or PES. Curable compositions thus prepared retain the thermal stability of BMI resins and the toughness of PEI or PES without the compatibility problems often encountered in the prior art. Additionally, the curable resins of the present invention have the advantage of eliminating the need to use organic vehicles, which are generally undesirable, thus reducing manufacturing costs and contamination control. Furthermore, quality control for hot-melt resin compositions is always easier in plant operations than for solvent-based resin compositions. The curable compositions produced by the method of the invention can be used for injection molding, resin transfer molding and pre-impregnation using conventional equipment, so that the resulting curable compositions are easy to use. be. Test method The physical properties in the examples described below were determined by the following method. 1 Fracture toughness The fracture energy (G _IC ) is determined according to ASTM E339-
Decide as provided in Article 83. Flexural modulus (E)
is determined by ASTM D790-82. Fracture toughness (K _IC ) is determined by ASTM E399-83 method. Poisson's ratio for the resin test plate is approximately
It was 0.38. 2 Shear modulus (G ^* ) Shear modulus is RMS of Rheometrics
- Determined by a rheometry mechanical spectrophotometer type 605. Set frequency to 1Hz and distortion to 0.8
% and the temperature was set to 350 at a rate of 5℃/min.
Raise to ℃. 3 Moisture Absorption The percentage moisture absorption was determined as specified by ASTM D570-81. The thickness of the test plate shall be approximately 1.5-1.6 mm. The time to absorb water to saturation is approximately 2 weeks. 4 Glass Transition Temperature (Tg) Glass transition temperature was determined by a DuPont 1090 Thermal Analyzer TMA model 947 analyzer.
The rate of temperature rise was 5°C/min. 5 Thermogravimetric Analysis (TGA) A DuPont Thermal Analyzer Model 951 gravimetric analyzer was used for thermogravimetric analysis. temperature from 100℃
The temperature was increased to 800°C at a rate of 20°C/min. As the purge gas, nitrogen gas was used at a flow rate of 30 ml/min. [Examples] Hereinafter, the present invention will be explained using examples to help understand the present invention, but these examples do not limit the scope of the present invention. Example 1 Solubility of high performance thermoplastics in diallyl compounds
TM123 was used to dissolve PEI and PES at different ratios and under different conditions to observe their miscibility. Dissolution was carried out at 140-160°C. The same procedure was repeated using polyamideimide (PAI), polyphenylene sulfide (PPS) or polyether-etherketone (PEEK) instead of PEI or PES for comparison purposes. PAI,
PPS and PEEK structural formulas and sources are shown in the table below. The results of the above observations are shown in the table below. As shown in the table, PES and PEI dissolve more easily in diallyl compounds.

【table】

【table】

[Table] Example 2 Comparison of flexural modulus (E), fracture toughness (K _IC ) and fracture energy (G _IC ) of high performance thermoplastic plastics including PEI and PES and different diallyl compounds including DABA and TM121. The mixture was dissolved by stirring at 160°C for about 6 hours. In some comparative examples, carboxy-terminated butadiene/acrylonitrile copolymer (CTBN) was used in place of the high performance thermoplastic. The BMI resin was then dissolved in the resulting mixture by stirring at about 140° C. for about 30 minutes. The resulting hotmelt was then degassed under reduced pressure for 10 minutes before casting. The casting mold was preheated to 140°C. The hot melt was then cured in a casting mold. The curing cycle is as follows: (1) Pre-curing Hot melt at 140°C Heating at a rate of 2°C/min = 200°C Constant temperature at 200°C for 3 hours, then cooling at a rate of no more than 2°C/min = Room temperature (2) Post-curing Heating at room temperature at a rate of 2°C/min = 240°C Constant temperature at 240°C for 5 hours, then cooling at a rate of less than 2°C/min = Ambient temperature Different relative ratios were used . The BMI resin used was 4,4'-bismaleimide-diphenylmethane. The flexural modulus, fracture toughness, and fracture energy were measured. The results are shown in Table 1. As is evident from this table, the compositions of the invention exhibit better mechanical properties.

Table Example 3 Comparison of Shear Modulus (G ^* , ×10 ⁹ dyne/cm ² ) The same manufacturing procedure as in Example 2 was repeated using different compositions. The BMI resin used was 4,4'-bismaleimide-diphenylmethane. The shear modulus was measured and is shown in the table.

[Table] As is clear from the table, the shear modulus at 117°C increased in the present invention. Example 5 Comparison of water uptake rates (absorbed to saturation at 160°) The same manufacturing procedure as in Example 2 was repeated using different compositions. The water absorption rates of these samples were measured and are shown in these tables.

【table】

[Table] * Comparative Example 6 Comparison by TGA Thermal Analysis The same manufacturing procedure as in Example 2 was repeated using different compositions. The specimens were then tested by TGA analysis. At 800℃ under _N2 gas purge
The TGA decomposition temperature and % residue are shown in the table.

[Table] *Comparison Although the present invention has been described above with reference to certain preferred embodiments, the scope of the present invention is not limited thereto.

Claims (1)

[Scope of Claims] 1. In producing a bismaleimide resin composition that can be cured to a tough and thermally stable matrix for composite materials, the formula () having a number average molecular weight of 3,000 to 50,000 is used. polyether-imide with a number average molecular weight of 3000 to 50000 A high performance thermoplastic selected from the group consisting of polyether-sulfones. [wherein A and B independently represent hydroxy or hydrogen, and X is 2,2-propanediyl, oxy, sulfonyl, sulfinyl, methylene, thio, difluoromethylene, or , where Y is 2,2-propanediyl,
oxy, sulfonyl, sulfinyl, methylene, thio or difluoromethylene] at a first dissolution temperature of 100 to 240°C to form a first mixture, [wherein R represents methylene, 2,2-propanediyl, difluoromethylene, oxy, thio, sulfinyl or sulfonyl] A bismaleimide resin selected from the group consisting of the following compounds is added to the first mixture at a concentration of 100 to 170%. A bismaleimide-based resin composition, characterized in that it is melted at a second melting temperature of °C to produce a bismaleimide-based resin composition in a hot melt state, which can be further processed in a hot melt type operation without the use of a solvent. manufacturing method. 2. The method of claim 1, wherein the bismaleimide resin composition comprises 20 to 80 parts by weight of a bismaleimide resin, 20 to 80 parts by weight of a diallyl compound, and 0 to 30 parts by weight of a high performance thermoplastic. 3. The method of claim 1, wherein the bismaleimide resin composition comprises 30 to 70 parts by weight of bismaleimide resin, 30 to 70 parts by weight of diallyl compound, and 2 to 25 parts by weight of high performance thermoplastic. 4. The method of claim 1, wherein the bismaleimide resin composition comprises 45 to 65 parts by weight of bismaleimide resin, 35 to 55 parts by weight of diallyl compound, and 5 to 20 parts by weight of high performance thermoplastic. 5 The first melting temperature is 120 to 200°C, and the second
The method according to claim 1, wherein the melting temperature is 140-160°C. 2. The method according to claim 1, wherein 6R represents methylene. A process according to claim 1, wherein 7X represents 2,2-propanediyl, oxy, sulfonyl, sulfinyl, methylene, thio or difluoromethylene. 8. The method according to claim 1, wherein the diallyl compound is O,O'-diallylbisphenol A. 9. A bismaleimide resin composition produced by the method according to any one of claims 1 to 8.