JPS6311363B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a curable composition having excellent heat resistance and comprising an aromatic imide and/or an amide imide amine and an epoxy resin having a β-alkylglycidyl group. Conventionally, in order to improve the heat resistance and rigidity of cured epoxy resin products, attempts have been made to introduce imide rings into the intramolecular skeleton. There are many examples in which a general-purpose epoxy resin (eg, diglycidyl ether of bisphenol A, etc.) is reacted with a curing agent having an imide skeleton. We conducted intensive research to improve the heat resistance of cured products of these general-purpose epoxy resins, and found that epoxy resins with β-alkylglycidyl groups instead of the commonly used glycidyl groups as epoxy groups, The present invention has been achieved by discovering that by using aromatic imide or amide imide amine as a curing agent, a cured product having excellent heat resistance, particularly heat decomposition resistance, can be obtained. It is thought that the presence of the alkyl group suppresses the decomposition of the hydroxyl group generated by curing, and that the heat resistance is improved because the skeleton has an imide ring. An object of the present invention is to provide an epoxy resin curable composition that has extremely good heat resistance. That is, the gist of the present invention is the general formula () (In the formula, Ar is

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A divalent aromatic organic group selected from the group consisting of [Formula] and their isomers, and Ar' is

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[Formula] and

[Formula] is a tetravalent aromatic organic group selected from the group consisting of 4
Each carbonyl group is directly bonded to a different carbon atom, and each pair of carbonyl groups is bonded to an adjacent carbon atom in the Ar′ group, and Ar′ is

[Imide polymer: IO-A]

Purified 3,3',4,4'-benzophenonetetracarboxylic dianhydride [hereinafter abbreviated as BTDA] in reflux with 0.45 mole of purified 2,4-diaminotoluene and dry N-methyl-2-pyrrolidone solution.
0.15 mole of dry N-methyl-2-pyrrolidone solution was added dropwise, and after expelling the produced water from the system, it was kept in a reflux state for 4 hours and imidized to obtain an imide polymer containing an amine end group. Total amine amount of product 3.70×10 ^-3 (eq・mol/g), Tm
[Kofler method] The temperature was 216°C. [Imide polymer: IO-B] A solution of 0.25 mole of BTDA in N-methyl-2-pyrrolidone was added dropwise to a solution of 0.375 mole of 2,4-diaminotoluene and N-methyl-2-pyrrolidone, and the generated water was removed from the system. The mixture was kept in a reflux state for 6 hours while being expelled to obtain an imide polymer containing an amine end group. Total amine amount 2.01×10 ^-3 (eq・mol/g),
Tm260℃ [Imide polymer: IO-C] 0.0094 mole of 3,3'-diaminobenzophenone and N-methyl-2-pyrrolidone solution was added dropwise to a reflux solution of 0.0063 mole of BTDA and N-methyl-2-pyrrolidone. The system was kept in a reflux state for 6 hours while expelling water from the system to obtain an imide polymer containing an amine end group. Total amine amount 1.30×10 ^-3
(eq・mol/g), Tm275℃ [Imide polymer: IO-D] 3,3′-diaminodiphenylsulfonate
An imide polymer containing an amine end group was obtained from 0.0081 mole and 0.0054 mole of BTDA in the same manner as IO-C. Total amine amount 1.65×10 ^-3 (eq・mol/g),
Tm265℃ (amideimide polymer: IO-E) 3,3'-diaminodiphenylsulfon
Add 0.15 mole 4-acid chloride of trimellitic anhydride to N-methyl-2-pyrrolidone solution at room temperature.
0.075 mole of N-methyl-2-pyrrolidone solution was added dropwise and kept at 30°C for 6 hours. Thereafter, the temperature was raised to expel generated water from the system, and the system was kept in a reflux state for 6 hours to obtain an amide-imide polymer containing an amine end group. Total amine amount 3.8×10 ^-3 (eq・mol/g),
Tm250℃ Production of aromatic amine epoxy resin containing β-methylglycidylamino group [GA-1] 107.2 g of metatoluidine in a four-necked flask
(1mole) and β-methylepichlorohydrin 319.6
g (6 mole) <3 times the equivalent> of lithium hydroxide
1.198g (0.05mole) and 200ml of ethanol, 20ml of water
was added and reacted for 8 hours at 60°C under a nitrogen atmosphere. After that, excess β-methylepichlorohydrin was removed by vacuum distillation, then 500 ml of toluene was added, and 184 g of 50% aqueous sodium hydroxide solution
1.15 times the amount was added dropwise through a dropping funnel and kept at 65°C for 3 hours. After the reaction, the product was washed with water several times in a separatory funnel, and the solvent layer was separated and distilled under reduced pressure at 95° C. and 8 mmHg to obtain a low viscosity liquid. The epoxy equivalent of this compound was 148 (g/eq). [GA-2] p-aminophenol in 1 four-necked flask
54.6g (0.5mole), β-methylepichlorohydrin 532.7g (5mol) <3.3 times the equivalent>, ethanol 100ml and lithium hydroxide hydrate 0.84g
Dissolved in 20 g of water, add 60 g of water under nitrogen atmosphere.
The reaction was carried out at ℃ for 6 hours. Then, after removing most of the excess β-methylepichlorohydrin by vacuum distillation,
400 ml of toluene was added, and 138 g of a 50% aqueous sodium hydroxide solution (1.15 times the equivalent amount) was added dropwise over 1 hour. Thereafter, the inside of the system was kept at 60°C for 2 hours. Approximately twice the amount of water was added to the reaction product and washed several times with water, and the organic layer was separated. This was distilled under reduced pressure at 100°C and 10 mmHg to obtain a liquid product. The epoxy equivalent weight of this compound was 121 (g/eq). [GA-3] 4,4′-diaminodiphenylmethane 100g
(0.51mole), β-methylepichlorohydrin 861
g (8.1 mole) <4 times the equivalent>, boron trifluoride -
0.5 g of ethyl ether complex was placed in a container equipped with a reflux condenser, thermometer, stirrer, and nitrogen blowing tube.
The mixture was added to a flask and the internal temperature was kept at 70°C for 6 hours. After removing most of the excess β-methylepichlorohydrin by distillation under reduced pressure, 500 ml of toluene was added, and then a 50% aqueous sodium hydroxide solution was added dropwise over 1 hour. The reaction was stopped by keeping the internal temperature at 65°C for 3 hours. The reaction mixture was filtered to remove precipitates, and further washed several times with about twice the amount of water to remove salt and excess alkali. Thereafter, toluene and residual β-methylepichlorohydrin were completely removed by vacuum distillation at 95° C. and 8 mmHg to obtain a reddish brown viscous liquid. The epoxy equivalent of this compound is 158 (g/eq)
It was hot. Comparative example of preparation of cured product 1 m-aminophenol triglycidyl type epoxy (product name: Sumitomo Chemical Co., Ltd., ELM-120)
[Epoxy equivalent 110-125g/eq] 100g and 4,4'-
43 g of diaminodiphenylmethane (DDM) was heated and mixed and cured in a mold at 150°C for 1 hour + 180°C for 5 hours to obtain a cured product. Vikatsu softening point temperature [Ts] of this cured product, thermal decomposition start temperature (10% weight reduction, Heating Rate 15℃/
min, in air) was measured. Comparative Example 2 Tetraglycidylamine type epoxy of 4,4'-diaminodiphenylmethane (trade name: Sumitomo Chemical Co., Ltd., ELM-434) [Epoxy equivalent: 110-130
g/eq] and 25.5 g of 4,4'-diaminodiphenylsulfonate (DDS) were dissolved in methyl ethyl ketone and placed on a glass plate or carbon fiber (trade name:
Toray Industries, Trading Card T-300) contains 60vol% carbon fiber
The impregnated and dried material is heated and pressed into a mold at 170
C./2 hours + 200.degree. C./17 hours to obtain a cured product. For the cured product on a glass plate, the thermal decomposition onset temperature was measured by TGA, and for the composite cured product, T _S was measured. Comparative Example 3 A varnish was prepared by dissolving 10 g of ELM-434 and 22.5 g of an amine end group-containing imide polymer (IO-A) in 48.8 g of N,N-dimethylformamide. 160℃/3 hours +200℃ by the same method as Comparative Example 2
The TGA and Ts of the cured product cured at ℃/17 hours were measured. Example 1 A varnish was prepared by dissolving 5 g of metatoluidine diβ-methylglycidyl type epoxy (GA-1 synthetic product) and 16.9 g of imide polymer (IO-B) in 32.9 g of N,N-dimethylformamide. did. 160℃/3 hours +200℃ by the same method as Comparative Example 2
The TGA and Ts of the cured product cured at ℃/17 hours were measured. Example 2 5 g of p-aminophenol triβ-methylglycidyl type epoxy (GA-2 synthetic product) and 20.6 g of imide polymer (IO-B) were mixed with 38.4 g of N,N
- A varnish was prepared by dissolving it in dimethylformamide. A cured product was prepared under the same conditions as in Example 1, and its TGA and Ts were measured. Example 3 Tetra β of 4,4′-diaminodiphenylmethane
- Methylglycidyl type epoxy (GA-3
Synthetic product) 5g and imide polymer (IO-A) 8.5g
A varnish was prepared by dissolving it in 20.3 g of N,N-dimethylformamide. A cured product was produced and evaluated under the same conditions as in Example 1. Example 4 5 g of GA-3 synthetic product and imide polymer (IO-B)
A varnish was prepared by dissolving 15.8 g in 31.2 g of N,N-dimethylformamide. A cured product was produced and evaluated under the same conditions as in Example 1. Example 5 2 g of GA-3 synthetic product and imide polymer (IO-C)
9.7g was dissolved in 17.6g of N,N-dimethylformamide, and 180
The cured product cured at 230° C. for 3 hours and 17 hours at 230° C. was evaluated. Example 6 5g of GA-3 synthetic product and imide polymer (IO-D)
19.2 g was dissolved in 36.3 g of N,N-dimethylformamide, and a cured product prepared under the same conditions as in Example 5 was evaluated. Example 7 5 g of GA-3 synthetic product and amide-imide polymer (IO
-E) 8.3g was dissolved in 20g of N,N-dimethylformamide to prepare a varnish. A cured product was produced and evaluated under the same conditions as in Example 1. Data for Comparative Examples 1 to 3 and Examples 1 to 7 are shown in Table 1. In addition, thermal decomposition comparison results for Comparative Examples 2 and 3 and Examples 3, 5, and 6 (Heating Rate 15℃/
Fig. 1 shows the data on a thermobalance at air 50 ml/min.

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【table】 [Brief explanation of the drawing]

FIG. 1 shows Comparative Examples 2 and 3, Examples 3 and 5,
6 shows the thermal decomposition comparison results at a heating rate of 15° C./min and a thermal balance of 50 ml/min.

Claims (1)

[Claims] 1 General formula () (In the formula, Ar is 2 selected from the group consisting of [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] and isomers thereof Ar′ is a tetravalent aromatic organic group selected from the group consisting of [Formula] [Formula] and [Formula], and each of the four carbonyl groups is directly bonded to a different carbon atom. And each pair of carbonyl groups is bonded to an adjacent carbon atom in the Ar' group, and Ar'' is a trivalent aromatic organic group represented by the formula, and each of the three carbonyl groups is bonded to a different carbon atom. is directly bonded to the atom, and the pair of carbonyl groups is bonded to adjacent carbon atoms in the Ar″ group, and n and m are 0 or a positive integer, and 5≧m+n>0
It is. ) and an aromatic amine epoxy resin containing a β-alkylglycidyl group.