JPH0214213A - Epoxy resin composition and prepreg therefrom - Google Patents

Abstract

PURPOSE:To provide the composition of high breaking elongation, elastic modulus and heat resistance, low water absorptivity and flame-retardancy, comprising each specific two kinds of epoxy resins and curing agent in specified proportion. CONSTITUTION:The objective epoxy resin composition can be obtained by blending (A) a brominated bisphenol A glycidyl ether-type epoxy resin, (B) a bisphenol F glycidyl ether-type epoxy resin, and (C) an aromatic diamine (pref. diaminodiphenylsulfone) so that the components A+B+C account for >=70wt.% of the final resin composition and the weight ratio A/B=(10:90)-(95:15), pref. (30:70)-(90:10). Incorporation of this epoxy resin composition as a matrix with a reinforcing fiber such as carbon fiber will obtain the other objective prepreg of both high mechanical strength and breaking elongation, high heat resistance, low water absorptivity and flame retardancy.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is directed to matrix resins and materials for advanced composite materials that require high elongation, high modulus of elasticity, high heat resistance, low water absorption, and flame retardancy. Regarding prepreg.

[Prior Art] Among curable resins, epoxy resins are widely used in various industrial fields due to their excellent mechanical properties. In particular, epoxy resins are often used in composite materials that include reinforcing fibers and matrix resin as essential components.

Composite materials are widely used in premium sports applications such as golf club shafts and fishing rods, and in structural material applications such as aircraft, due to their high specific strength and specific modulus.

However, the epoxy resins used in these composite materials have even greater strength, elastic modulus, toughness, heat resistance, water resistance,
Furthermore, flame retardancy is required.

Epoxy resins currently used in aircraft composite materials have N,N,N',N'-tetraglycidyldiaminodiphenylmethane as a main component, and diaminodiphenyl sulfone is used as a curing agent. Although this resin composition has high heat resistance, the resin composition has low resin elongation and becomes a brittle cured product. Although CFRP obtained from this resin composition exhibits excellent heat resistance, it has a drawback of low toughness.

There are many types of epoxy resins, each with different physical properties such as modulus of elasticity, elongation at break, heat resistance, and water absorption.

When used as a matrix resin for CFRP, which is generally an epoxy resin, several types of epoxy resins are blended to obtain a composition that meets the required characteristics. For example, the N, N,
N',N'-tetraglycidyldiaminodiphenylmethane has a small resin elongation at break. In order to improve this, it is conceivable to blend a bisphenol A glycidyl ether type epoxy resin or a bisphenol F glycidyl ether type epoxy resin, which has a large elongation at break. in this case,
It is true that the resin elongation at break improves, but on the other hand, the elastic modulus and heat resistance decrease. In other words, the physical properties of the composition do not often deviate greatly from the values calculated assuming that additivity is established from the physical properties of the basic epoxy resin alone.
It can be said that in a simple formulation of epoxy resins, heat resistance, elastic modulus, and elongation at break generally remain in a trade-off relationship.

[Problems to be Solved by the Invention] As described above, when preparing an epoxy resin composition, the elongation greatly exceeds the value calculated on the assumption that additivity is established from the physical properties of the basic epoxy resin alone. , elastic modulus, high heat resistance, low water absorption, and flame retardancy, it has hitherto been considered difficult to obtain a resin composition. The inventors of the present invention have conducted intensive studies on this problem, and have unexpectedly found a resin composition that satisfies the above-mentioned characteristics, thereby completing the present invention.

[Means for solving problems] In order to achieve the above object, the present invention has the following configuration.

(1) The following components [A], [B], and [C] are essential components, and the components [A] + [B] + [C] are 70vtX or more of the resin composition, and [A] acid Ingredient [B
] An epoxy resin composition characterized in that the blending ratio of acid components is in the range of 10:90 to 95:15 by weight.

[A: Nibrominated bisphenol A glycidyl ether type epoxy resin [B: Bisphenol F glycidyl ether type epoxy resin [C: Aromatic diamine (2) The following components [A], [B], and [C are required] The components [A] + [B] + [C] are 70 wtJ or more of the resin composition, and the blending ratio of [A] acid component [B] acid component is 10:90 to 95:15 by weight. A prepreg mainly consisting of an epoxy resin composition and reinforcing fibers.

[A] Nibrominated bisphenol A glycidyl ether type epoxy resin [B]: Bisphenol F glycidyl ether type epoxy resin [C: aromatic diamine (3) In claim (1), [C] acid component diaminodiphenyl An epoxy resin composition that is a sulfone.

(4) A prepreg in which [C] the acid component is diaminodiphenylsulfone in claim (2).

(5) In claim (1), the blending ratio of [A] acid component and [B] acid component is 30:70 to 90:1 by weight.
0, and the [C] acid component is diaminodiphenylsulfone.

(6) In claim (2), the blending ratio of [A] acid component and [B] acid component is 30:70 to 90:1 by weight.
A prepreg using an epoxy resin composition in which the [C] acid component is diaminodiphenylsulfone.

The brominated bisphenol A glycidyl ether type epoxy resin used as component [A] in the present invention is commercially available, for example, under a trade name such as Evicron 152 (manufactured by Dainippon Ink and Chemicals). The structural formula of this resin is shown below.

Brominated bisphenol A glycidyl ether type epoxy resin has bromine with a large atomic number attached to a benzene ring as a substituent, and is characterized by low water absorption and flame retardancy. The cured resin obtained by curing this resin at 180°C for 2 hours using a chemical equivalent of 4,4'-diaminodiphenylsulfone as a curing agent has a flexural modulus of about 380 kg/mm2 and a breaking elongation of about 3. It is 5%.

The bisphenol F glycidyl ether type epoxy resin used as component [B] in the present invention is Epiclon 830 (Dainippon Ink & Chemicals Co., Ltd. "t", Ebicor).
It is commercially available under trade names such as 807 (manufactured by Yuka Shell Epoxy Co., Ltd.). This epoxy resin has a very low viscosity,
By adding it, the viscosity of the composition can be reduced and workability can be improved. When used as a resin for prepreg, the tack and drape properties are improved, which is very preferable. The cured resin obtained by curing this resin for 2 hours at 180°C using a chemical equivalent of 4,4'-diaminodiphenylsulfone as a curing agent has a flexural modulus of approximately 360 kg/n+m2 and a breaking elongation in a dry state at room temperature. It is about 7.0%.

The aromatic diamine used as component [C] in the present invention is often used as a curing agent for epoxy resins. Examples include diaminodiphenylmethane and diaminodiphenylsulfone. Resins cured using these curing agents have excellent heat resistance, and diaminodiphenylsulfone is particularly suitable. Depending on the position where the amino group attaches to the benzene ring, 4.4' +, 3.4' -, 3,
It can be classified into three types: 3'-, and all three types are suitable for the present invention. 4,4'-diaminodiphenyl sulfone is commercially available under trade names such as Sumigure S (manufactured by Sumitomo Chemical Industries, Ltd.).

In the present invention, constituent elements [A] + [B] + [C
] is 70 wt% or more of the resin composition. Also, the blending ratio (weight) of components [A] and [B] is 10:90 to 9
The range is 5:5, more preferably 30:70-9
The range is 0:10.

Generally, the physical properties of an epoxy resin composition do not often deviate greatly from values calculated on the assumption that additivity is established from the physical properties of the basic epoxy resin alone. For example, component [A] is 90 wt$, component [B] is 10wt
When compounding X, the physical properties of the cured resin cured for 2 hours at 180°C using a chemical equivalent of 4,4'-diaminodiphenylsulfone as a curing agent are approximately the values proportionally distributed based on the weight fractions of both components. It can be predicted that That is, the bending elastic modulus in a dry state at room temperature is 380 kg/mm2
XO.

9+360kg/mm2X sail 1= 378 kg/im
2. Breaking elongation is 3゜5XX0.9+7.0%: Xo, 1
= 3, 9%.

However, surprisingly, the physical properties of the above-mentioned compounded resin actually prepared were that the flexural modulus was about 400 kg/mm" and the breaking elongation was about 6.
．． It was 7%. It showed physical properties that far exceeded expectations in terms of elasticity, elastic modulus, and elongation at break. Such cases have not been reported so far.

Moreover, over a fairly wide range of blending ratios of both ingredients,
The development of these properties of high elastic modulus and high elongation is unexpected and worthy of attention.

Further, excellent features of this resin composition include low water absorption and flame retardancy. These two properties are already known as features of brominated bisphenol A glycidyl ether type epoxy resins. Since the epoxy resin composition of the present invention contains a large amount of this brominated bisphenol A glycidyl ether type epoxy resin, it is easy to understand that it also has these features.

In this case, it goes without saying that the higher the content of the brominated bisphenol A glycidyl needle type epoxy resin, the lower the water absorption and the higher the flame retardancy.

The reinforcing fibers used in the present invention include carbon fiber, glass fiber, aramid fiber, silicon carbide fiber, and alumina! ! Examples include, but are not limited to, A fiber, boron fiber, and tank stainless carbide fiber. Also,
These can be used in combination, and the shape is not limited.

A composite material obtained from a prepreg obtained by combining the above resin and these reinforcing fibers has high strength and high elongation, reflecting the high elongation and high modulus of elasticity of the resin.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

[Example 1] A resin composition having the following composition was prepared.

[A] Abrominated bisphenol A glycidyl ether epoxy resin (manufactured by Dainippon Ink Industries, Ltd., Epiclon 152)
--1----90 parts by weight [B Copisphenol F glycidyl ether type epoxy resin (Dainippon Ink Industries, Ltd.!!, Epicron 830)
--1----10 Heavy melon part [C] 4.4' Diaminodiphenylsulfone (manufactured by Kaito Kagaku Kogyo Co., Ltd., Sumicure 5)---1----18 Serious part prepared in advance Pour the above compounded resin into the mold, place it in an oven, and let it harden for 2 hours at 180°C.
A cured resin plate with a thickness of +nm was prepared.

A dumbbell-shaped tensile test sample was cut out from this according to JIS K-7113-1 and subjected to a tensile test. Autograph crosshead speed is 1mm/m
in, closed. In addition, a strip-shaped test piece with a width of 1 cm was cut out and used for measuring the bending elastic modulus. The ratio of span (1) to sample thickness (d) was l/d=16, and the crosshead speed was 2.5 mm/min. The bending modulus of elasticity was measured not only in a dry state at room temperature but also in a sample that had been boiled and absorbed water for 20 hours and then heated to a predetermined temperature. The measurement results are shown in Table 2. This greatly exceeds the value calculated on the assumption that additivity is established from the elongation at break and elastic modulus of the basic epoxy resin alone.

[Example 2] Example except that the component [A] was 70 parts by weight, the component [B] was 30 parts by weight, and the component [C] was 20 parts by weight]
The same procedure was repeated. The results are shown in Table 2. This greatly exceeds the value calculated on the assumption that additivity is established from the elongation at break and elastic modulus of the basic epoxy resin alone.

Compressive strength in the 0° force direction and tensile elongation in the 90' direction of a composite using a unidirectional prepreg using this resin as a matrix were measured. The prepreg was prepared as follows.

A resin having the above composition was prepared in a kneader and coated to a constant thickness on a release paper to which a silicone mold release agent had been thinly applied in advance. Using a carbon fiber trading card T800H (manufactured by Toshiku Co., Ltd.), carbon fibers were aligned in one direction between two sheets of resin-coated paper prepared previously and then pressed together to obtain a prepreg. At this time, the weight fraction of resin in the prepreg was 35%. Eight sheets of this prepreg were laminated in a single direction and heated in an autoclave at 180° C. for 2 hours under a pressure of 6 kg/am 2 to obtain a cured plate having a thickness of about 1 mm. Glue the tab to this hardened plate and
A 0° compression test was conducted according to TM-D 695.

The results showed a compressive strength of 1721<g/mm''.

Furthermore, 16 sheets of the above prepreg were laminated in a single direction, and the 90° tensile elongation was measured using a cured plate formed in the same manner and found to be 1.5%.

[Example 3] Example 1 except that the component [A] was 40 parts by weight, the component [B] was 60 parts by weight, and the component [C] was 23 parts by weight.
The same procedure was repeated. The results are shown in Table 2. This greatly exceeds the value calculated on the assumption that additivity is established from the elongation at break and elastic modulus of the basic epoxy resin alone.

[Example 4] The same hand trill as in Example 1 was repeated except that 3,3'-diaminodiphenylsulfone was used as component [C]. The results are shown in Table 2.

[Comparative Example 1] Tetrag-blade cydyldiaminodiphenylmethane (ELM434: Order Kagaku Kogyo) was used at 90%
The same procedure as in Example 1 was repeated except that 50 parts by weight of 4,4'diaminodiphenyl sulfone was added as component [C].

The results are shown in Table 2. This shows good agreement with the value calculated on the assumption that additivity is established from the elongation at break and elastic modulus of the basic epoxy resin alone.

Compressive strength in the 06 direction and tensile elongation in the 90° direction of a composite using a unidirectional Bripreg using this resin as a matrix were measured. The prepreg was prepared as follows.

A resin having the above composition was prepared in a kneader and coated to a constant thickness on a release paper to which a silicone mold release agent had been thinly applied in advance. Using Carbon Fiber Trading Card 7800H (manufactured by Toshiku Co., Ltd.), carbon fibers were aligned in one direction between two sheets of resin-coated paper prepared previously and then pressed together to obtain a prepreg. At this time, the weight fraction of resin in the prepreg was 35%. Eight sheets of this prepreg were laminated in a single direction and heated at 180° C. for 2 hours in an autoclave under a pressure of 6 k3/cm'' to obtain a cured plate having a thickness of about 1 mm. Glue the tab to this hardened plate and
A 0° compression test was conducted according to TM-D 695.

The results showed a compressive strength of 1701<8/n+m''.Furthermore, 16 sheets of the above prepreg were laminated in a single direction and the 90° tensile elongation was measured using a cured plate formed in the same way. The elongation was low at 9%.

[Comparative Example 2] 2-diglycidylamino 5- instead of component [A]
Using 90 parts by weight of glycidyl ether toluene (ELMIoo: Order Kagaku Kogyo), 4,4 as the component [C]
'The same procedure as in Example 1 was repeated except that 55 parts by weight of diaminodiphenyl sulfone was added. The results are shown in Table 2. This shows good agreement with the value calculated on the assumption that additivity is established from the elongation at break and elastic modulus of the basic epoxy resin alone.

[Comparative Example 3] 90 parts by weight of bisphenol A glycidyl ether type epoxy resin was used instead of component [A], and component [
C] as 4,4'diaminodiphenyl sulfone as 40
The same procedure as in Example 1 was repeated except that part by weight was added. The results are shown in Table 2.

This shows good agreement with the value calculated on the assumption that additivity is established from the elongation at break and elastic modulus of the basic epoxy resin alone.

[Comparative Example 4] 10 parts by weight of bisphenol A glycidyl ether type epoxy resin was used instead of component [B], and component [B] was replaced with component [B].
C] 4,42 diaminodiphenyl sulfone as 20
The same procedure as in Example 1 was repeated except that part by weight was added. The results are shown in Table 2.

This shows good agreement with the value calculated on the assumption that additivity is established from the elongation at break and elastic modulus of the basic epoxy resin alone.

[Effects of the Invention] The epoxy resin composition according to the present invention has high elongation, high elastic modulus, high heat resistance, low water absorption, and flame retardancy. moreover,
A fiber-reinforced composite material obtained from a prepreg using this as a matrix resin has high strength, high elongation, high heat resistance, low water absorption, and flame retardancy.

Claims (6)

[Claims] (1) The following components [A], [B], and [C] are essential components, and the components [A] + [B] + [C] account for 70 wt% or more of the resin composition, and [A] An epoxy resin composition characterized in that the blending ratio of component and component [B] is in the range of 10:90 to 95:15 by weight. [A]: Brominated bisphenol A glycidyl ether type epoxy resin [B]: Bisphenol F glycidyl ether type epoxy resin [C]: Aromatic diamine (2) The following components [A], [B], and [C] are essential components, and the components [A] + [B] + [C] account for 70 wt% or more of the resin composition, and [A] A prepreg mainly consisting of an epoxy resin composition and reinforcing fibers, characterized in that the blending ratio of component and component [B] is in the range of 10:90 to 95:15 by weight. [A]: Brominated bisphenol A glycidyl ether type epoxy resin [B]: Bisphenol F glycidyl ether type epoxy resin [C]: Aromatic diamine (3) An epoxy resin composition according to claim (1), wherein component [C] is diaminodiphenylsulfone. (4) The prepreg according to claim (2), wherein the component [C] is diaminodiphenylsulfone. (5) In claim (1), the blending ratio of component [A] and component [B] is 30:70 to 90:1 by weight.
0, and the [C] component is diaminodiphenylsulfone. (6) In claim (2), the blending ratio of component [A] and component [B] is 30:70 to 90:1 by weight.
A prepreg using an epoxy resin composition in which the component [C] is diaminodiphenylsulfone.