JPH0717732B2 - Structural material using epoxy resin composition as matrix resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a structural material comprising an epoxy resin composition having excellent heat resistance, flexibility and the like and excellent water resistance as a matrix resin.

[Conventional technology]

Epoxy resin has excellent heat resistance, electrical insulation, chemical resistance, and mechanical properties, so it is used as a paint adhesive, sealant,
Widely used in the field of structural materials. In particular, in recent years, composite materials with carbon fibers (CFRP) have mechanical strength and elastic modulus equal to or higher than that of metals and can be made lighter, and structural materials for aerospace equipment, railways, automobiles, etc. It is used as a base material for the transportation industry such as the above, or as a leisure member such as a golf shaft, a fishing rod, and a ski, and is expected to make great progress in the future.

[Problems to be solved by the invention]

CFRP using epoxy resin as a matrix resin has the elongation (flexibility) required for aircraft primary structure,
At present, there is no composition that fully satisfies the functions such as heat resistance, water resistance, and elastic modulus. An epoxy resin having a spiroacetal ring is known as a resin that gives a resin composition having excellent flexibility. The resins described in USP3347871 and US338098 are excellent in heat resistance and impact resistance, but have a drawback of low flexibility.

In addition, epoxy resin (bisphenol type epoxy resin,
It has the drawback of low compatibility with novolac type resins).

[Means for solving problems]

The present inventors have earnestly studied in order to develop a structural material using a resin excellent in flexibility and heat resistance as a matrix resin. [In formula, n shows the integer of 0-15. ] Tricyclo represented by [5, 2, 1, found that O ^{2, 6]} decane ring (hereinafter abbreviated as dicyclopentadiene derivative) epoxy resin is fit for the intended purpose, and have reached the present invention .

The resin [I] represented by the above general formula is soluble in an organic solvent such as a ketone solvent, tetrahydrofuran or chloroform, and is compatible with various epoxy resins and the like. That is, the gist of the present invention is that the general formula [I] A mixture of 10 to 90% by weight of an epoxy resin (component A) having a dicyclopentadiene derivative represented by: and 10 to 40% by weight of an epoxy resin (component B) selected from a bisphenol type epoxy resin, a novolac type epoxy resin. The present invention relates to a structural material having a matrix resin of an epoxy resin composition obtained by blending a curing agent with, and diaminoxylene is advantageously used as the curing agent.

[Action]

The epoxy compound having a dicyclopentadiene derivative of the component (A) represented by the general formula [I] of the present invention is disclosed in
It is manufactured by the method shown in 59-245795.

That is, it can be obtained by reacting a resin obtained by polymerizing cresols and dicyclopentadiene with epichlorohydrin.

The epoxy resin as the component (B) lowers the viscosity of the composition, improves the mixability with fibers, inorganic powder, etc. (bisphenol epoxy resin), and improves the heat resistance of the cured product (phenol novolac epoxy). (Resin etc.)

By containing the dicyclopentadiene derivative in the component (A), it is possible to improve the moisture resistance of the molding material and obtain a composition having excellent flexibility. In addition, moisture resistance can be further improved by containing alkylphenols.

The component (A) is used in a proportion of 10 to 90% by weight, preferably 40 to 70% by weight in the epoxy resin component. If it is less than 10% by weight, flexibility of the cured product cannot be obtained.

As the curing agent for curing these epoxy resins, various curing agents similar to known epoxy resins can be used. Examples thereof include aliphatic amines, aromatic amines, heterocyclic amines, Lewis acids such as boron trifluoride and salts thereof, organic acids, and organic acid anhydrides. Specific examples thereof include, for example, diaminodiphene, rumethane, diaminodiphenylsulfone, 2-4-diamino-
Aromatic amines such as m-xylene; imidazoles such as 2-methylimidazole, 2,4,5-triphenylimidazole and 1-cyanoethyl-2-methyl-imidazole, or substituted imidazoles or salts of these with organic acids; Organic carboxylic acids such as trimellitic acid and hexahydrophthalic acid; organic acid anhydrides such as tetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, hexahydrophthalic anhydride, pyromellitic anhydride; dicyandiamide, methamine, guanamine, etc. Urea derivative; triethylenetetramine, xylylenediamine, isophoronediamine, 1,8-diazabicyclo (5,4,0) undecene-7
Fatty acid polyamines such as Phenol type novolac resin and the like can be used. The curing agents may be used alone or in combination. The amount used is in the range of 0.01 to 1.0% by weight based on the total amount of the main agent and the curing agent.

In addition to the curing agent, the epoxy resin composition may further contain carbon fiber, glass fiber, plasticizer, organic solvent, reactive diluent, extender, filler, reinforcing agent, pigment, flame retardant, if necessary. Various additives such as agents, thickeners, accelerators, and plasticizers can be added. As the curing accelerator for the epoxy resin, generally used heterocyclic amines, Lewis acids such as boron trifluoride and salts thereof, organic acids, organic acid anhydrides, urea or derivatives thereof are used alone. One or a mixture thereof can be used.

〔Example〕

Preparation Example of Component A 1000 parts of para-cresol was charged into a reactor equipped with a thermometer, a cooler, a stirrer and a dropping tube, and while maintaining the temperature at 100 ± 5 ° C, 15 parts of 47% BF ₃ ether complex was added. 416.9 parts of dicyclopentadiene was added dropwise over 4 hours.
After the dropping, the temperature was kept at 100 ± 5 ° C. for 1 hour, and then unreacted para-cresol and BF ₃ were distilled off at 150 ° C. and 4 mmHg to obtain 950 parts of a polymerized portion.

Next, 100 parts by weight of the obtained product and 1 part of tetramethylammonium bromide were dissolved in 250 parts of epichlorohydrin,
The reaction was carried out at 0 ± 5 ° C for 10 hours. After completion of the addition reaction, attach a water separator and add 36 parts of 50% by weight aqueous sodium hydroxide solution.Sequentially add water from the reaction system so that the water content in the reaction system falls within the range of 0.1 to 2.0% by weight during the addition. separated. After the whole amount was dropped, the reaction was carried out for 4 hours, and then epichlorohydrin was distilled under reduced pressure. After the remaining reaction product was dissolved in methyl isobutyl ketone, sodium chloride in the reaction system was filtered off, the filtrate was further washed with pure water, and then the organic solvent was distilled off from the organic layer to obtain an epoxy resin of component A. It was

Examples 1 to 4 A component dicyclopentane / phenolic polymer epoxy resin (DCE-400) B component Table 1 curing agent xylylenediamine curing accelerator 2-methylimidazole was added to prepare an epoxy resin composition.

The curing agent, xylenediamine, was added in a stoichiometric ratio. 0.5 parts of 2-methylimidazole was added.

This resin composition was thoroughly kneaded with a twin-screw roll and
It was cured at 4 ° C for 4 hours and further at 200 ° C for 2 hours to obtain a cured product.

The physical properties of this cured product are shown in Table 1.

Comparative Examples 1 to 3 Epoxy resin compositions having the compositions shown in Table 1 were prepared and cured in the same manner as in Examples 1 to 4 to obtain cured products.

The results are shown in Table-1.

Examples 5 and 6, Comparative Examples 4 and 5 (Examples of Application to Laminated Plates) Dicyclopentadiene / phenolic polymer epoxy resin (DCE-400) as an epoxy resin, orthocresol novolac type epoxy resin (epoxy equivalent 218 g, Nippon Kayaku) Co., Ltd., hereinafter abbreviated as "EOCN") and bisphenol A type epoxy resin (epoxy equivalent 470 g; trade name: DY-
011, manufactured by Tobu Kasei Co., Ltd., hereinafter abbreviated as "BAE") as a flame retardant, brominated bisphenol A type epoxy resin (epoxy equivalent: 400 g; trade name: YDB-400, manufactured by Toto Kasei Co., Ltd.,
Hereinafter, abbreviated as “TBBAE”) and dicyandiamide as a curing agent are used to prepare a resin varnish having a composition shown in Table 2 (60% by weight of a resin component), which is impregnated into a glass cloth (E-glass). After that, the varnish-impregnated cloth was dried in a drying chamber at 160 ° C. for 4 minutes to obtain a B-stage prepreg.

Eight prepregs obtained by cutting the above prepreg are stacked, and one layer of electrolytic copper foil with a thickness of 35 μm is further stacked on each side of the prepreg, and pressure heating is performed at a pressure of 40 kg / cm ² and a temperature of 175 ° C. for 120 minutes. Then, a laminated board was prepared.

Table 2 shows the physical properties of the obtained cured laminate. The test method of each physical property value is as follows.

(1) Measured by glass transition temperature DSC (2) Water absorption (according to JIS C6481) Measure the weight increase after boiling for 50 hours in 100 ° C water (3) Peel strength (according to JIS C6481) ( 4) Dielectric properties (according to JIS C6481) As can be seen from Table 2, the laminated board using the dicyclopentadiene / phenolic resin modified epoxy resin is heat resistant,
Moisture resistance, adhesion and electrical properties were good.

Example 7 (Application example to CFRP) 3500 g of dicyclopentadiene / phenolic polymer epoxy resin (DCE-400), 1000 g of orthocresol novolac type epoxy resin (epoxy equivalent 218 g), 500 g of bisphenol A type epoxy resin (epoxy equivalent 470 g), Four,
1120 g of 4'-diaminosulfone and 23 g of boron trifluoride monoethylamine were placed in a kneader preheated to 65 ° C and sufficiently mixed to obtain an epoxy resin composition. Carbon fiber "Torayca T-30" in which this resin composition is aligned in one direction
"0" trade name, manufactured by Toray Industries, Inc., was impregnated by the hot melt method to prepare a unidirectional prepreg with a resin content of 34% by weight.

The obtained prepreg is cut into a piece with a length of 30 cm and a width of 30 cm, 8 pieces of this are laminated, placed on a release-treated aluminum plate, covered with a vacuum bag made of nylon, and the bag is evacuated and then placed in an autoclave. , After pressurizing to 6kg / cm ² ,
The temperature was raised at 1.5 ° C / min, and heating was performed at 180 ° C for 2 hours to obtain a cured plate. The carbon plate content of the obtained cured plate was 58% by volume, and the plate thickness was 1.1 mm. From this cured plate, a 0 ° tensile test piece having a length of 230 mm and a width of 12.72 mm was cut out in the fiber direction. A glass dove having a length of 50 mm, a width of 12.72 mm and a tapered portion of 10 mm was adhered to both ends of the test piece. A strain gauge was attached to the center of the test piece with the dove and pulled at a pulling speed of 1 mm / min to measure the tensile properties.
The measurement results are shown in Table 3.

Further, a test piece was cut out from this cured plate according to ASTM D695 and the compression properties were measured. The results are shown in Table 3.

Also, cut the prepreg to a length of 35 cm and a width of 30 cm, and cut it.
16 sheets were laminated. This laminated plate was treated in the same manner as above to prepare a cured plate. The carbon fiber content of this hardened board is 60
% By volume and plate thickness was 2.2 mm. From this cured plate, the length is 230 mm and the width is 25.41 mm in the 90 ° direction with respect to the carbon fiber.
A 90 ° tensile test piece was cut out. A strain gauge was attached to the center of the test piece, and the test piece was pulled at a pulling rate of 1 mm / min to measure the tensile properties. The results are shown in Table 3.

Further, the interlaminar shear strength of a test piece cut out from this cured plate according to ASTM D2344 was measured. This measurement result is shown in Table 3.
Shown in.

Further, a test piece was cut out from this cured plate according to ASTM D2344 and the interlaminar shear strength was measured. The measurement results are shown in Table 3.

From these measurement results, it was confirmed that the tensile properties, heat resistance and water resistance were excellent.

Comparative Example 6 N, N, N ', N'-tetraglycidyl diaminodiphenylmethane 2500 g, 4,4'-diaminodiphenyl sulfone 1200 g
And boron trifluoride monoethylamine were added to a kneader heated to 65 ° C. and mixed sufficiently to prepare an epoxy resin composition,
Thereafter, in the same manner as in Example 7, a unidirectional prepreg having a resin content of 34% by weight was produced. Using this prepreg, 0 ° and 90 ° tensile physical properties, compression physical properties, and interlaminar shear strength were measured in the same manner as in Example 7. The results are shown in Table 4.

As can be seen from these results, only CFRP having poor tensile properties and water resistance was obtained.

Claims (2)

[Claims] 1. A general formula [I] [In formula, n shows the integer of 0-15. ] 10 to 90% by weight of an epoxy resin (A component) having a tricyclo [5,2,1, O ^2,6 ] decane ring represented by the following, and an epoxy resin selected from a bisphenol type epoxy resin and a novolac type epoxy resin ( (Structure B) A structural material comprising an epoxy resin composition as a matrix resin, characterized by being mixed with a curing agent in a mixture of 10 to 40% by weight. 2. A structural material comprising the epoxy resin composition according to claim 1 as a matrix resin, wherein the curing agent is diaminoxylene.