JPH059262A - Epoxy resin composition - Google Patents

Abstract

(57) [Summary] [Purpose] It has excellent storage stability and handleability, and in particular it has excellent curing characteristics, toughness, and impact resistance at low temperatures (around 80 ° C), and is particularly suitable for prepreg. Also, to provide an epoxy resin composition having excellent physical properties such as hardness of a cured product. An epoxy resin having a number average molecular weight of 400 to 900 and a ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight / number average molecular weight) of 1.1 to 3.0 (1
00 parts by weight) and a microcapsule type curing agent (5 to 200
Parts by weight) and a thermoplastic resin having a glass transition temperature of 100 ° C. or higher (2 to 40 parts by weight).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to epoxy resin compositions, and more specifically, elastic modulus,
Epoxy resin composition having excellent hardness and heat resistance, particularly excellent toughness, impact resistance, storage stability, and low temperature (around 80 ° C.) curing characteristics and handleability, for example, materials for civil engineering and construction, Excellent epoxy resin composition that can obtain paints, lining materials, adhesives, electrical equipment molding materials, machine parts, jigs, matrix resins for fiber reinforced composite materials (hereinafter abbreviated as FRP), especially suitable for prepreg And an epoxy resin composition.

[0002]

BACKGROUND OF THE INVENTION Epoxy resins are excellent in heat resistance, elastic modulus, hardness and chemical resistance, and are widely used in composite materials composed of reinforced fibers such as aramid fiber, glass fiber and carbon fiber and a matrix resin. There is. However,
Conventional epoxy resins have various problems depending on the application and method of use. In particular, there is a problem in the mechanical strength of FRP when used as a matrix resin for FRP, especially the toughness that affects impact resistance, fatigue characteristics and the like. Therefore, when the epoxy resin is used as a matrix resin, in order to provide flexibility to the matrix resin, that is, the epoxy resin cured product, and to provide an epoxy resin cured product having excellent mechanical strength, particularly toughness, for example, Various methods such as selecting a curing agent and adding a flexibility-imparting agent have been studied.

With such a conventional method, the flexibility of the cured epoxy resin can be improved to some extent, but the physical characteristics such as the elastic modulus, hardness and heat resistance which are the original features of the cured epoxy resin. Of the FRP was not significantly improved, and chemical resistance, weather resistance, and
There arises a problem that water resistance is also reduced.

On the other hand, JP-A-62-127317 discloses an epoxy resin composition for prepreg, which comprises at least two or more polyepoxy compounds in one molecule, a high molecular weight epoxy resin, dicyandiamide, and / or a curing accelerator. It is disclosed.

However, when such an epoxy resin composition is used as an epoxy resin composition for prepreg, there are problems in tackiness, drapeability, resin flowability, workability, storage stability, etc. Was desired.

In order to improve this point, the present inventors have previously stated that "the bisphenol A-based epoxy resin contains a bisphenol A-based epoxy resin and an epoxy resin curing agent.
An epoxy resin composition characterized by containing 10 to 40 parts by weight of an epoxy equivalent of 190 or less, and having a total number average molecular weight of 650 to 1300 "has been proposed (Japanese Patent Application No. Sho 63-63).
-77325).

Such an epoxy resin composition is excellent in tack property, drape property, workability and storage stability when used as a resin for prepreg. Since the epoxy resin has a high number average molecular weight and a high melt viscosity, it cannot be said that the tackiness and drapability are always good at room temperature or lower, and the tackiness and drapability change depending on the ambient temperature. Therefore, it does not exhibit stable properties in a wide temperature range.

In order to improve these drawbacks, excellent tackiness and drapeability are exhibited not only at high temperature but also at room temperature or below, and these properties are stable and tough over a wide temperature range. Contains a bisphenol A epoxy resin and an epoxy resin curing agent as an epoxy resin composition that gives an excellent molded product such as mechanical performance such as flexibility and the like, and the bisphenol A epoxy resin has a number average molecular weight of 450 to An epoxy resin composition having a ratio of 700 to 700 and a ratio of weight average molecular weight to number average molecular weight (weight average molecular weight / number average molecular weight) of 1.3 to 3.0 was proposed (Japanese Patent Application No. 63-190047).

Further, in order to improve storage stability, handleability, curing characteristics at low temperature, etc., an epoxy resin and a microcapsule type epoxy resin curing agent are contained, and the epoxy resin has a number average molecular weight of 500 to 1200. And the ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight
An epoxy resin composition having a (number average molecular weight) of 1.2 to 3.0 was proposed.

However, such an epoxy resin composition is not yet satisfactory in terms of toughness, impact resistance and the like.

[0011]

DISCLOSURE OF THE INVENTION The present invention is excellent in elastic modulus, hardness and heat resistance, and particularly excellent in toughness, impact resistance, storage stability and handleability, and has excellent curing characteristics even at low temperatures. An object is to provide an epoxy resin composition provided.

[0012]

According to the present invention, 100 parts by weight of an epoxy resin, 5 to 200 parts by weight of a microcapsule type epoxy resin curing agent and a glass transition temperature of 100 ° C are used.
The epoxy resin has a number average molecular weight of 400 to 900 and a ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight / number average molecular weight) of 1 to 40. There is provided an epoxy resin composition characterized by being 0.1 to 3.0, and an epoxy resin composition characterized by further containing another latent curing agent.

That is, the present inventors have found that the epoxy resin composition for prepreg is excellent in various physical properties, and is also excellent in storage stability, handleability and curing characteristics especially at low temperature, particularly toughness and impact resistance. As a result of earnestly examining the thing,
The specific number average molecular weight, the epoxy resin having a ratio of the specific weight average molecular weight and the number average molecular weight, by incorporating a microcapsule curing agent and a thermoplastic resin in a specific ratio, surprisingly the intended purpose In particular, it has been found that it is possible to achieve the objectives of improving the toughness, impact resistance, handleability, storage stability, and at the same time, curing characteristics at low temperature when used as a prepreg.

The first characteristic of the epoxy resin used in the present invention is that its number average molecular weight is in the range of 400 to 900. When the number average molecular weight is less than 400, the amount of low molecular weight components becomes too much, resulting in poor tackiness and drape of the prepreg, resin flowability becomes large during curing, and physical properties of the cured product, particularly toughness, deteriorate. However, the intended purpose of the present invention cannot be achieved. The number average molecular weight is 900
If it exceeds, the tackiness and drapability at room temperature will deteriorate due to the small amount of low molecular weight components, and at lower temperatures than that, the tackiness and drapability will deteriorate, making it impossible to handle as prepreg. ..

The second characteristic of the epoxy resin used in the present invention is that the ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight / number average molecular weight) is 1.1 to 3.0, preferably 1.3.
It is in the range of to 2.5.

When the ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight / number average molecular weight) is less than 1.1, the amount of low molecular weight components is too much, and the tackiness of the prepreg is highly temperature dependent. Not easy to handle. When the ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight / number average molecular weight) exceeds 3.0, the high molecular weight component becomes too much, and the tackiness of the prepreg becomes insufficient.

Specific examples of the epoxy resin used in the present invention include bisphenol A type epoxy resins,
For example, Epicor 1001, 1004, 100 manufactured by Yuka Shell Co., Ltd.
It can be prepared by appropriately combining 7, 1009, 1010 (trade name) and the like. Further, as other epoxy resin, for example,
Glycidyl ether epoxy resin (bisphenol F, bisphenol S epoxy resin), novolac epoxy resin, brominated bisphenol A epoxy resin, cycloaliphatic epoxy resin, glycidyl ester epoxy resin, glycidyl amine epoxy resin, heterocycle Formula epoxy resin etc. can be mentioned. These epoxy resins can be appropriately combined and prepared.

The microcapsule type curing agent used in the present invention has a curing agent as a core and is coated with an epoxy resin, a polyurethane resin, a polystyrene-based polymer substance, cyclodextrin or the like as a shell.
The contact between the epoxy resin and the curing agent is reduced.

Particularly, as the shell material, a curing agent (called a masterbatch type curing agent) in which a microcapsule type curing agent using an epoxy resin or a polyurethane resin and an epoxy resin are mixed at a fixed ratio is In addition to being excellent in stability, blending with epoxy resin
It is uniform and easy and has excellent curing characteristics. Examples of the epoxy resin used for the masterbatch type curing agent include the epoxy resins described above. At this time, the viscosity of the masterbatch type curing agent is 25 ° C. from the viewpoint of handleability.
Therefore, 5,000 to 5,000,000 cps is preferable.

In the present invention, as the epoxy resin curing agent as the core material, any one or more kinds of commercially available epoxy resin curing agents may be selected and used. As such a curing agent, for example, amines: aliphatic primary amine [polyamine (diethylenetriamine (DETA),
Triethylenetetramine (TTA), tetraethylenepentamine (TEPA), dipropylenetriamine (DPTA), polymethylenediamine (trimethylhexamethylenediamine (TM
D), polyetherdiamine, diethylaminopropylamine (DEAPA)), alicyclic polyamine (mensendiamine (MD
A)), an aliphatic amine containing an aromatic ring (meta-xylenediamine)
(MXDA)], aromatic primary amine [metaphenylenediamine
(MPDA), diaminodiphenylmethane (DDM), diaminodiphenylsulfone (DDS), an aromatic diamine eutectic mixture], 3,9-bis (3-aminopropyl) -2,4,8,10-tetraspiro (5,5 ] Undecane (ATU), modified amines (amine adducts, cyanoethylated polyamines), secondary and tertiary amines [linear diamines, linear tertiary amines, tetramethylguanidine, piperidine, pyridine, picoline, benzyldimethylamine, 2- (Dimethylaminomethyl) phenol (DMP-10)], polyamide resin (condensation product of dimer acid and polyamine); acid anhydrides: aromatic acid anhydrides [(phthalic anhydride (PA), trimellitic anhydride (TMA), ethylene glycol bis (anhydrotrimellitate) (TME), glycerol tris (anhydrotrimellitate) (TMG), pyromellitic dianhydride (PMDA), 3,3 ', 4,4'-benzophenone Without tetracarboxylic acid Aqueous product (BTDA)], cycloaliphatic acid anhydride [(maleic anhydride (MA), succinic anhydride (SA), tetrahydrophthalic anhydride (THPA), methyltetrahydrophthalic anhydride (Me-
THPA), methyl nadic acid anhydride (NMA), alkenyl succinic anhydride, hexahydrophthalic anhydride (HHPA), methylhexahydrophthalic anhydride (Me-HHPA), methylcyclohexene tetracarboxylic acid anhydride (MCTC)], aliphatic Acid anhydride,
Polycarboxylic acid anhydride, halogenated acid anhydride, chloresic acid anhydride (CA); polyamide resin [N, N′-bis (6-aminohexyl) adipamide], imidazoles [2-methylimidazole (2MZ), 2 -Ethyl-4 methyl imidazole (2E4M
Z), 2-undecylimidazole (C11Z), 2-heptadecylimidazole (C17Z), 2-phenylimidazole (2PZ), 1
-Benzyl-2-methylimidazole (1B2MZ), 1-cyanoethyl-2-methylimidazole (2MZCM), 1-cyanoethyl-2
-Undecyl imidazolium trimellitate (C11ZCN
S), 2,4-diamino-6- [2-methylimidazolyl- (1)]-ethyl-S-triazine (2MZAZAZINE), quaternary salt (1-dodecyl-2)
-Methyl-3-benzylimidazolium chloride), isocyanurate (2-phenylimidazolium isocyanurate (2PZ-OK)), hydroxymethyl compound (2-phenyl-4-methyl-5-hydroxymethylimidazole (2P4MHZ)) , Boron trifluoride-amine complex, dicyandiamide
(DICY) and its derivatives, (0-tolylbiguanide, α-2, 5
-Dimethyl biguanide), organic acid hydrazide (succinic acid hydrazide (SaADH), adipic acid hydrazide (AADH)],
Derivatives with diaminomaleonitrile (DAMN) (DAMNBZ), melamine and its derivatives (diallylmelamine), amine imide (AI), polyamine salts, oligomers: synthetic resin initial condensate (novolac phenol resin, novolac cresol resin), polyvinyl Mention may be made of phenol (poly-P-vinylphenol).

Particularly, it is preferable to use imidazoles, whereby an epoxy resin composition for prepreg excellent in tack property, drape property, resin flow property, workability, storage stability and low temperature curability is obtained. be able to.

The microcapsule type epoxy resin curing agent is used in an amount of 5 to 200 parts by weight based on 100 parts by weight of the epoxy resin. If the amount of the curing agent is less than 5 parts by weight, the curing will be insufficient, and if it exceeds 200 parts by weight, the amount of the curing agent will be excessive, resulting in poor performance after curing. Further, other latent curing agents can be added to the epoxy resin composition of the present invention.

The glass transition temperature used in the present invention is 100 ° C.
Examples of the above-mentioned thermoplastic resin include polyether sulfone, polyvinyl formal, phenoxy resin, polyether imide and the like, and those having high toughness and compatibility with epoxy resin can be used.

The thermoplastic resin is used in an amount of 2 to 40 parts by weight based on 100 parts by weight of the epoxy resin.
If it is less than 40 parts by weight, the impact resistance is insufficient.

Furthermore, additives such as fillers and diluents can be used within a range that does not lose the above-mentioned various properties.

[0026]

EXAMPLES Next, the present invention will be described in more detail by way of examples.

Example 1 Epicoat 8 as a bisphenol A epoxy resin
28 (epoxy equivalent 184-194, number average molecular weight 38
0), 1001 (epoxy equivalent 450-600, number average molecular weight 900), 1004 (epoxy equivalent 875-97)
5, number average molecular weight 1600) and Asahi Kasei Co., Ltd. HX3722 were used as a hardening | curing agent. After PES (polyether sulfone) was added to the epoxy resin components shown in Table 1 and mixed by heating at 150 ° C., the mixture was cooled to 70 ° C. and the curing agent of HX3722 was mixed at 50 Phr (blending ratio).
By adding, an epoxy resin composition for prepreg showing a low temperature rapid curing property was prepared. This was poured into a mold composed of two glass plates and a Teflon spacer, and heated at 100 ° C. for 2 hours to be cured. The epoxy resin cured product thus obtained was cut into a test piece from a resin casting plate of 30 cm × 30 cm × 3 mm to measure the impact resistance strength (IZOD). The results are shown in Table 1. Further, this was an epoxy resin having excellent tackiness, drapeability, resin flowability, handleability, storage stability and low-temperature curability for prepreg. Further, the carbon fibers (strength 350 kg / mm ² ,
An elastic modulus of 24 t / mm ² ) was impregnated to obtain a prepreg. It was found that this prepreg was excellent in impact resistance and tackiness. The composition of Example 1 had excellent storage stability, good workability during production, and good properties as a prepreg.

Example 2 PEI (polyetherimide) dissolved in 3 times the amount of methylene chloride was added to the epoxy resin components shown in Table 1 and mixed, and this mixture was degassed under reduced pressure at 100 ° C. for 1 hour. Then, the methylene chloride was completely removed and then cooled to 70 ° C., and 100 phr of a HX3722 curing agent was added to prepare an epoxy resin composition. Various properties of the obtained epoxy resin composition were measured in the same manner as in Example 1. The results are shown in Table 1.

Examples 3 to 6 The epoxy resins obtained by adding the thermoplastic resins shown in Table 1 to the epoxy resin components shown in Table 1 and mixing them to prepare an epoxy resin composition in the same manner as in Example 1 Various properties of the resin composition were measured in the same manner as in Example 1. The results are shown in Table 1.
Shown in.

Comparative Examples 1 to 6 No epoxy resin was added to the epoxy resin components shown in Table 1, or the thermoplastic resins shown in Table 1 were added and mixed, and the epoxy resin composition was obtained in the same manner as in Example 1. The properties of the obtained epoxy resin composition were measured in the same manner as in Example 1. The results are shown in Table 1.

The symbols in Table 1 are shown below. EP828; Bisphenol A epoxy resin Epicoat 828 manufactured by Yuka Shell Co., Ltd. EP1001; Bisphenol A manufactured by Yuka Shell Co., Ltd.
Type epoxy resin Epicoat 1001 EP1004; Bisphenol A manufactured by Yuka Shell Co., Ltd.
Type epoxy resin Epicoat 1004 EP1007; Bisphenol A manufactured by Yuka Shell Co., Ltd.
Epoxy resin Epicoat 1008 EP1010; Bisphenol A manufactured by Yuka Shell Co., Ltd.
Epoxy resin Epicoat 1010 HX3722; Asahi Kasei Corp. masterbatch type curing agent DICY; Dicyandiamide type curing agent DCMU; Dichloromethylurea type curing agent PES; Polyethersulfone PEI; Polyetherimide storage stability; 50 ° C., 5 Degree of increase in Tg after standing for a day Handleability; Tackiness at 23 ° C. is evaluated by touch (tackiness) ○ ・ ・ ・ Good × ・ ・ ・ Poor Mn; Number average molecular weight Mw; Weight average molecular weight Tg: Glass transition temperature

[0032]

[Table 1]

[0033]

The epoxy resin composition of the present invention has a number average molecular weight of 400 to 900 and a ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight / number average molecular weight) of 1.1 to 3.
Since it is composed of an epoxy resin of 0, a microcapsule type epoxy resin curing agent, and a thermoplastic resin having a glass transition temperature of 100 ° C. or higher, especially when used for prepreg, tackiness, draping property, resin flow property, It is excellent in handleability, storage stability and low temperature curability, especially toughness and impact resistance, and also in physical properties of the cured product.

Claims (1)

Claims: 1. An epoxy resin of 100 parts by weight, a microcapsule type epoxy resin curing agent of 5 to 200 parts by weight, and a thermoplastic resin having a glass transition temperature of 100 ° C. or higher of 2 to 40 parts by weight. Epoxy resin has a number average molecular weight of 40
0 to 900, and the ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight / number average molecular weight) is 1.1 to
An epoxy resin composition having a value of 3.0.