JPS61168621A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:An epoxy resin composition excellent in heat resistance, water resistance and elongation at break, prepared by adding a specified curing agent to an epoxy resin comprising an aromatic glycidylamine epoxy and a triphenol triglycidyl ether derivative. CONSTITUTION:An epoxy resin composition comprising an epoxy resin composed of at most 90wt% aromatic glycidylamine epoxy (A) and 10-100wt% triphenol triglycidyl ether derivative (B) of formula I (wherein R is an aliphatic group, an aromatic ring-containing group or a heterocyclic ring-containing group) and a curing agent (C) of formula II (wherein n is 3-5), wherein 0.3<=R<=1.2(bnot equal to 0) when R=c/(a+c), wherein (a) is the number of epoxy groups in aromatic glycidylamine epoxy (A) in the composition, (b) is the number of epoxy groups in the triphenol triglycidyl ether derivative (B) in the composition, and (c) is the number of active hydrogenatoms in the curing agent (C) in the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an epoxy resin composition that has improved water resistance and elongation at break without impairing heat resistance.

[Prior art]

Recently, composite materials obtained by impregnating carbon fibers with resin and curing them, so-called carbon fiber reinforced plastics (hereinafter referred to as CFRP), have come to be widely used as primary structural materials for aircraft. .

Conventionally, epoxy resin compositions have been mainly used as resins for impregnating carbon fibers. In particular, when heat resistance is desired, epoxy resins such as tetraglycidyldiaminodiphenylmethane (TGDDM) and diaminodiphenylsulfone (D) are added as a curing agent. Epoxy resin compositions containing D S) have been widely used. However, this T
GDDM/DDS-based epoxy resin compositions have excellent initial heat resistance and adhesion to carbon fibers, but they suffer from significant decreases in heat resistance due to moisture absorption, as well as high hardness and low elongation. There are drawbacks.

As described above, conventional epoxy resin compositions are not satisfactory for use as aircraft structural materials, requiring high heat resistance and elongation of 2% or more.

[Purpose of the invention]

The present invention provides an epoxy resin composition for prepreg that is excellent in heat resistance, water resistance (particularly a reduction in glass transition point (Tg) after moisture absorption), and elongation at break, and is suitable for impregnating high elongation carbon fibers. The purpose is to provide something.

[Structure of the invention]

For this reason, the present invention provides a combination of 90% by weight or less of aromatic glycidylamine epoxy (A) and trisphenol represented by the following formula (R: aliphatic group, aromatic ring-containing group, heterocycle-containing group). It consists of an epoxy resin consisting of 10 to 100% by weight of a triglycidyl ether derivative (B) and a curing agent (C) represented by the following formula (% formula %), R=c/(a+b) (in the above formula, a : Number of epoxy groups in the aromatic glycidylamine epoxy (A) in the formulation, b: Number of epoxy groups in the triglycidyl ether derivative of trisphenol (B) in the formulation, C: Curing in the formulation number of active hydrogens in agent (C)), 0.3≦R≦
The gist of this invention is an epoxy resin composition characterized by having a b% of 0.

Hereinafter, the configuration of the present invention will be explained in detail.

In the present invention, 90% by weight or less of an aromatic glycidylamine epoxy (A) represented by tetraglycidyldiaminodiphenylmethane (TGDDM), liglycidyl p-aminophenol, etc., and a triglycidyl ether of trisphenol represented by the following formula. Derivative (B) 10
~100% by weight of epoxy resin is used. This derivative (B) also includes the triglycidyl ether of trisphenol itself.

In the above formula, R is an aliphatic group such as CH, C2H4, 03H6; C(-Cs H5), C2(-Cs
Hs ) H3, C2(-C8Hs ) z A group containing an aromatic ring such as H2 ic3 A group containing a heterocyclic ring such as H2N3.

The epoxy resin comprises 90% by weight or less of the aromatic glycidylamine epoxy (A) and 10 to 1% of the derivative (B).
00% by weight.

This is because if the derivative (B) is contained in an amount less than 10% by weight, the heat resistance will be poor and the heat and humidity resistance will also be reduced. In addition, aromatic glycidylamine epoxy (A) 90
% by weight or less includes 0% by weight, that is, the case where it is not contained at all.

Further, in the present invention, an aromatic diamine represented by the following formula is used as the curing agent (C).

(n=3 to 5) This aromatic diamine contains one amino group in each layer but no other substituents. For example, para-nitrobenzoyl chloride is mixed with a diol having 3 to 5 carbon atoms. It can be obtained by reacting with diamine and reducing the generated compound to diamine.

The epoxy resin composition of the present invention is composed of the above-mentioned epoxy resin and the above-mentioned curing agent (C), and when R=C/ (a + b), 0.3≦R≦1.2, preferably 0.5≦R
It has a value of ≦1.0 (b'to).

In the above formula, a is the number of epoxy groups in the aromatic glycidylamine epoxy (A) in the formulation, b is the number of epoxy groups in the triglycidyl ether derivative of trisphenol (B) in the formulation, C each represents the number of active hydrogens in the curing agent (C) in the formulation.

In the above formula, when R<0.3, the amount of curing agent is too small, and the resulting epoxy resin composition has low elongation and is inferior in water resistance and heat resistance. Also,
If R>1.2, the amount of curing agent will be excessive, resulting in poor water resistance and heat resistance, making it impossible to achieve the object of the present invention.

Note that a curing accelerator or the like may be added to this epoxy resin composition, if necessary.

〔Effect of the invention〕

As explained above, since the epoxy resin composition of the present invention has the above-mentioned formulation, it can improve water resistance and elongation at break without impairing heat resistance. Therefore, it is extremely useful for applications such as primary structural materials of aircraft.

EXAMPLES The effects of the present invention will be specifically explained below with reference to Examples and Comparative Examples.

Example I N,N,N',N'-tetraglycidyldiaminodiphenylmethane 60 phr (TGDDM) Triglycidyl nymole derivative of trisphenol (epoxy equivalent weight 220) 40 phr
rl, 3-propanediol divalaminobenzoate 40.1 phrBF
! - Monoethylamine (catalyst) 0.5 phr The resin composition of the above formulation is cured at 180°C for 2 hours, and the resulting cured product has a shear modulus of elasticity at 121°C (G'121t+)
, the ratio of shear modulus at 121°C and 40°C (G'x2
1'r:J/G', [11:J), Tg, Tg after 10 days of immersion in 80°C warm water, and strain in bending test were measured. The results are shown in Table 1 below.

Example 2 N,N,N',N'-tetraglycidyldiaminodiphenylmethane 40 phr (TGDDM) Triglycidyl ether derivative of trisphenol (epoxy equivalent 220) 60 phr
rl, 3-propanediol dipraminobenzoate 35.7 phrBF
3-Monoethylamine (catalyst) 0.5 phr The same test as in Example 1 was conducted on the resin composition having the above formulation. The results are shown in Table-1.

Example 3 N,N,N',N'-tetraglycidyldiaminodiphenylmethane 80 phr (TGDDM) Triglycidyl ether derivative of trisphenol (epoxy equivalent 196) 20 phr
rl, 3-propanediol divalaminobenzoate 45.3 phrBF
3-Monoethylamine (catalyst) 0.5 phr The same test as in Example 1 was conducted on the resin composition having the above formulation. The results are shown in Table-1.

Example 4 Triglycidyl ether derivative of trisphenol (epoxy equivalent: 22') 100ph
r1.3-Propanediol dipraminobenzoate 26.8 phrBF
3-Monoethylamine (catalyst) 0.5 phr The same test as in Example 1 was conducted on the resin composition having the above formulation. The results are shown in Table-1.

Comparative Example I N,N,N',N'-Tetraglycidyldiaminodiphenylmethane 1100 phr (TGDD) 1.3-Propanediol dipraminobenzoate 49.1 phrBF
3-Monoethylamine (catalyst) 0.5 phr The same test as in Example 1 was conducted on the resin composition having the above formulation. The results are shown in Table-1.

(Margins below this page) As is clear from Table 1 above, the epoxy resin composition of the present invention is superior in heat resistance and water resistance compared to conventional compositions.

Claims (1)

[Claims] 90% by weight or less of aromatic glycidylamine epoxy (A) and the following formula ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (R: Contains an aliphatic group, a group containing an aromatic ring, a heterocycle) An epoxy resin consisting of 10 to 100% by weight of a trisphenol triglycidyl ether derivative (B) represented by curing agent (C), R = c / (a + b) (in the above formula, a: number of epoxy groups in the aromatic glycidylamine epoxy (A) in the formulation, b: trisphenol in the formulation The number of epoxy groups in the triglycidyl ether derivative (B), c: the number of active hydrogens in the curing agent (C) in the formulation), then 0.3≦R≦
1.2 (b~0). An epoxy resin composition.