JPS59155422A - Epoxy resin composition for use in filament winding - Google Patents

Abstract

PURPOSE:The titled composition having a long pot life and a low viscosity desirable for the production of a bubble-free FRP of high resistance, comprising a specified epoxy resin, an acid anhydride curing agent and a cure accelerator. CONSTITUTION:An epoxy resin composition with a viscosity of 0.8-4.5P (40 deg.C), comprising (A) 100pts.wt. low-viscosity bisphenol F-derived opoxy resin and (B) 25-230pts.wt. phenol novolak epoxy resin of the formula and/or epoxy resin at least three glycidyl groups in the molecule (e.g., N,N,N',N'-tetraglycidyldiaminodiphenylmethane) is mixed with (C) 0.8-1.2 equivalent, per epoxy equivalent of total of components A and B, acid anhydride curing agent (e.g., methyltetrahydrophthalic anhydride) and (D) 0.1-5pts.wt. per 100pts.wt. total of components A and B, cure accelerator (e.g., 2-ethyl-4-methylimidazole.).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to an epoxy resin composition for filament winding for producing fiber reinforced plastics (hereinafter referred to as FRP) having excellent mechanical properties. This invention relates to an epoxy resin composition with a low viscosity and a long pot life suitable for producing bubble-free FRP using the filament winding method.

Since the filament winding method requires the reinforcing material to be continuously impregnated with resin, the resin used must be a low-viscosity liquid resin, and in order to manufacture large molded products, it is necessary to use a resin composition. Due to constraints such as the need for a long pot life, selection of a resin composition is an important issue when implementing the filament winding method. Especially in the case of epoxy resins, it is extremely difficult to select a resin composition with low viscosity and a long pot life.In particular, it is extremely difficult to select a resin composition that has high heat resistance and is suitable for obtaining bubble-free FRP by low-pressure molding. The thing is almost unknown.

As conventional epoxy resin compositions for filament winding, compositions using reactive diluents and curing agents (methyl nadic anhydride or liquid aromatic diamine modified products) are known ("Handbook of
Fillers and Reinforcement
ts for Plastics j Katz & M
by ilewski, Van N08trandRein
hold company, new york,
1978, pp. 528-529). However, when a reactive diluent is used, the heat resistance is lowered, and when methylnadic anhydride or a liquid aromatic diamine modified product is used as a curing agent, the viscosity is low and it is difficult to obtain a bubble-free FRP. Furthermore, if heating is applied to lower the viscosity, it will be difficult to maintain a sufficiently long pot life, such as when producing large molded products.

Further, since some aromatic diamines are known to be carcinogenic or some are suspected of being carcinogenic, unfortunately, the use of resin compositions containing aromatic diamines may be severely restricted.

Therefore, as a result of intensive research into an epoxy resin composition with low viscosity and a long pot life, which is suitable for producing FRP with high heat resistance and no bubbles by the filament winding method, the present inventor has achieved the present invention. It's arrived.

In other words, low viscosity bisphenol F is used as an epoxy resin.
A type epoxy resin is used as component (4), and in addition, a low-viscosity polyfunctional phenol novolak type epoxy resin and/or an epoxy resin having at least three glycidyl groups in the molecule is blended as component (B). This improves the heat resistance and heat resistance.

The phenol novolac type epoxy fat used in the present invention as the component (B) is a 5-epoxy crumb fat whose main component is an epoxy compound represented by the following general formula,
Specifically, Epicote (hereinafter abbreviated as Ep)-152
, Ep-1, 54 (all manufactured by Yuka Shell Epoxy Co., Ltd.)
(manufactured by).

Further, the epoxy resin having at least three glycidyl groups in the molecule of component (B) can specifically include the following resins.

N,N,N',N'-tetraglycidyldiaminodiphenylmecne, N,N-diglycidyl-m-amine phenylglycidyl ether, N,N-diglycidyl-p-aminophenylglycidyl ether, N,N,N' , N'-
Tetraglycidyl metaxylylene diamine, N, N
, N',N'-tetraglycidylcyclohexanediamine. These are Araldite MY72o (manufactured by Ciba Geigy Co., Ltd., trade name L YH484 (manufactured by Tobu Kasei Co., Ltd., trade name), YDM120 (manufactured by Tobu Kasei Co., Ltd., trade name), and Araldite) 0500 (manufactured by Ciba Geigy Co., Ltd., trade name). , TET RAD-X (manufactured by Mitsubishi Gas Chemical Co., Ltd., product name), TETRAD-Of Mitsubishi Gas Chemical Co., Ltd.
It is commercially available under the trade name (trade name).

Since the epoxy resin is polyfunctional, it has a high crosslinking density and forms a cured product with high elasticity and excellent heat resistance. However, in the filament winding method, if the viscosity of the resin is high, it is difficult to control the amount of resin attached to the fiber bundle, and air bubbles cannot be easily removed.On the other hand, if the viscosity of the resin is too low, the fiber bundle cannot sufficiently retain the impregnated resin. First, it becomes difficult to adjust the predetermined amount of resin. The viscosity range at 40° C. is 0.8 to 4.5 voices, in which the fiber bundle is well impregnated with the resin and the air bubbles brought into the fiber bundle during impregnation can be easily removed.

Here, the blending ratio of component (B) is 2 parts per 100 parts by weight of the bisphenol F type epoxy resin of component (A).
It is preferably 5 to 280 parts by weight. That is, if it is less than 25 parts by weight, the heat resistance will be insufficient, while if it exceeds 230 parts by weight, it will be 40 parts by weight.
The viscosity at ゛C is 4.5 I voids or more, and the viscosity is too high to obtain a bubble-free FRP.In addition, in the present invention, the low viscosity of the (0) component as well as the (A) and (B) components An acid anhydride curing agent and a curing accelerator as component (D) are blended.

(As the acid anhydride curing agent for the C1 component, there are methyltetrahydrophthalic anhydride and methylhegisahide U phthalic anhydride, and the blending ratio is 0.8 to 1 per equivalent of the epoxy group of the component (A + B). .2 equivalent is better. If it is less than 0.8 equivalent, the crosslinking density will be small and physical properties such as heat resistance will be deteriorated. On the other hand, if it exceeds 1.2 equivalent, unreacted curing agent will remain and this will have a plastic effect. and deteriorate the physical properties.

In addition, (DJ acid component curing accelerators include tertiary amines, imidazoles, boron trifluoride complex salts, metal soaps, etc.) 4.2-ethyl-4-methylimidazole, especially for pot life and heat resistance. is preferable, and the blending ratio of component (D) is preferably 0° to 5 parts by weight per 100 parts by weight of components (A+B).In other words, if it is less than 0.1 part by weight, the reactivity will not improve; Exceeding the limit will shorten the pot life, which is not desirable.

Next, the 1ift composition of the present invention can be used as a reinforcing material for all materials normally used as reinforcing materials for FRP, such as glass fibers, organic fibers, and carbon fibers.

The epoxy resin composition of the present invention has high heat resistance due to the above-mentioned composition, has a low viscosity suitable for manufacturing bubble-free FRP by the filament winding method, and has a long pot life, so it can be used for large filaments. This invention is suitable for manufacturing wind-molded products, and is particularly used for applications such as automobile plate springs and drive shafts.The present invention will now be described with reference to Examples and Comparative Examples.

Examples: Bisphenol F type epoxy resin (Ep-8o 7, trade name, manufactured by Yuka Shell Epoxy Co., Ltd.) 800, phenol novolac type epoxy (teeth side (Ep-152, trade name, manufactured by Yuka Shell Epoxy Co., Ltd.) ) 200, methyltetra-hydrophthalic anhydride r* (Hitachi Chemical Co., Ltd.)
manufactured by HN-2200, trade name) 865-no and 2-ethyl-4-methylimidazole (Shikoku Fine Chemical Co., Ltd.)
2E41MZX (trade name) manufactured by Co., Ltd.) were sufficiently stirred and mixed to prepare a resin composition. The viscosity of this resin composition measured with a B-type viscometer at 40°C was 2.1 voices, and the pot life was 8 hours or more.

Next, in order to evaluate the performance of the resin composition, glass fibers (manufactured by Asahi Fiberglass Co., Ltd., R200 SE 08, trade name, (fiber loading diameter 28μ, filament size 2000) were continuously added to the resin composition heated to 40°C. ,.

The material was wound around a plate-shaped mandrel using the filament winding method while immersed in water, and this was inserted between the hot plates of a hydraulic press, and the material was pressurized to 1 to Vcm2 and cured at 120"C for 2 hours. A rough texture was obtained. The cured board] was after-cured for 2 hours in an oven at 50'C to obtain a completely cured board.The obtained cured board was free of air bubbles and had a glass fiber content of 6o valley weight. The glass transition temperature Tp according to TMA (thermal mechanical analysis) is 1
The temperature was 34°C.

Width 25 x length s o x /-1 za 3 from this hardened plate
A sample of mrn was prepared and the characteristics of the song measured according to JIS K-7203 were as shown in Table 1. However, the distance between the supporting points during measurement was 5 Q IrM. Also 100℃
The retention rate was 70 inches or more, and it had excellent heat resistance.

Example 2 Methylhexahydrophthalic anhydride (manufactured by Hitachi Chemical Co., Ltd., HN-5500, trade name) 8802 was used in place of methyltetrahydrophthalic anhydride in Example 1, and the other components were the same as the resin composition. I prepared something. This resin Mi7I
31: The viscosity measured with a B-type viscometer at 40°C was 2.2 voices, and the pot life was 8 hours or more.

Then, a cured plate was obtained under the same conditions as in Example 1.

The obtained cured plate had no air bubbles, the content of glass fiber was 60%, and the T temperature by TMA was 143°C. On the other hand, the bending properties measured in accordance with JIS-7203 in the same manner as in Example 1 are shown in Table 1, and the retention rate at 100°C was 70 coefficient or higher, indicating excellent heat resistance. .

Example 8 Ep-8, 07800, N, N, N', N'-tetraglycidyldiaminodiphenylmetadi (Toto Kasei Co., Ltd. YH-484) 200, HN-220094,02
and 2E4MZ5 were sufficiently stirred and mixed to prepare a resin composition. The viscosity of this resin composition measured with a Type B viscometer at 40''C was 2.2 voices, and the pot life was 8 hours or more.

Then, a cured plate was obtained under the same conditions as in Example 1.

The obtained cured board had no air bubbles, the glass fiber content was 60% by volume, and the T9 measured by TMA was 58"C.Meanwhile, it was measured in the same manner as in Example 1 according to JISK-7203. The bending properties obtained are shown in Table 1, and 100
The retention rate at C was 80 inches or more, and it had excellent heat resistance.

Comparative Example 1 In Example 8, Ep
-80710007, HN-22009009 and 2
Using E4MZ5, the mixture was thoroughly stirred and mixed to prepare a resin composition. The viscosity of this resin composition was 1°7 poise as measured with a Type B viscometer at 40°C, and the bot life was 8 hours or more.

Then, a cured plate was obtained under the same conditions as in Example 1.

Obtained. There were no air bubbles in the cured board, the oil content in the glass fibers was 60%, and the T temperature by TMA was 122°C. On the other hand, a sample similar to that in Example 1 was made and the bending properties were measured in accordance with JIS K-7203.
As shown in the table, the retention rate at 100°C was 60% or more, and the heat resistance was inferior to that of the cured plate of the present invention.

Comparative Example 2 Bisphenol A type epoxy resin (Ep-8 manufactured by Yuka Shell Epoxy Co., Ltd.) was used instead of the epoxy resin of Example 1.
28) 10009 and methylnadic anhydride (Nippon Kayaku (
Kayahard MCD) 900 (manufactured by Kayahard Co., Ltd.) and benzyl dimethylamine (BDMA, manufactured by Kako Soap Co., Ltd.) 1,09 were sufficiently stirred and mixed to prepare a resin composition.

The viscosity of this resin composition measured with a B-type viscometer at 40°C was 6 voids, and the pot life was 8 hours or more.

Then, a cured plate was obtained under the same conditions as in Example 1.

The resulting cured board contained 3.5% of air bubbles, estimated from the relationship between specific gravity and fiber content, and had significantly poor strength.

Comparative Example 3 ゛ Alicyclic epoxy resin “a” was used instead of the epoxy resin of Example 1.
i fat, 314-epoxycyclohexylmethyl = 3.
4-Epoxycyclohexanecarboxylate (Union Carbide 4221.) 10009 and HN-2
20011,009,2E4MZ5 were sufficiently stirred and mixed to prepare a resin composition.

Then, a cured plate was obtained under the same conditions as in Example 1.

The glass fiber content of the obtained cured plate was 70% by volume, and the bending strength was 10511% (2) with a 22° CG trowel, which was slightly lower.

Example 4 The blending ratio (abundance) of Ep-807 and Ep-152 was 80=
Mixed resin 10009 varying from 20 to 30 near 0
Then, HN-22009009 and 10 g of 2E4MZ were sufficiently stirred to prepare a resin composition. 2.6 For comparison, the ratio of Ep-807 and Ep-152 was set to 80:
20~so:mixed resin 1000 in proportions other than 'yo
g100O:0 or O:100) as well as HN
A resin composition was prepared by stirring with -2200, 9009, 2E4MZ1.0. The viscosity of this resin composition measured with a B-type viscometer at 40°C and the bending strength at 100°C of a cured plate obtained under the same conditions as in Example 1 were determined as follows.
As shown in the figure. As is clear from Figure 1, Ep for comparison
-If the composition exceeds 15,270 parts by weight, the viscosity will be 4.
Dogs from 5 voices (glass fiber content 60 or more)
As a result, the impregnation of the resin into the glass fibers is reduced, air bubbles are mixed in, and the air bubble ratio becomes 1 volume or more. When air bubbles are mixed in, the interlaminar shear strength is significantly reduced as shown in FIG. If the amount is less than 20 parts by weight, the bending strength retention rate at 100°C will be 70 inches or less, resulting in poor heat resistance. Therefore, it can be seen that Ep-152 is preferably in the range of 20 to 70 parts by weight, that is, 25 to 230 parts by weight based on 100 parts by weight of Ep-807. The glass fiber content in this case is 60
He was in charge of capacity.

Test example Glass fiber (manufactured by Asahi Glass Fiber, R2220TA-
FO8) A bundle of 20 pieces was impregnated with the resin compositions of Examples 1 to 8 and Comparative Examples 1 to 3, and wound in 26 layers in the axial direction of the mandrel.
By curing under the same conditions as in Example 1, a prototype automobile leaf spring as shown in FIG. 3 was manufactured. Spring constant of leaf spring, 8
Table 2 shows the results of the fatigue and durability tests at 0'C. However, in Figure 8, 1l-110 (lI, Z 2-550
” s W 1-80 '+m −.

W2 ”' 50 am, tl-1, 9m Hirot2-12
IIIm.

The spring constants of the leaf springs prototyped from the resin compositions of Comparative Examples 2 and 8 were 3-4"'Anm and 4"'Anm, respectively.
-2- "'/nm, which was outside the design tolerance range, so it was not subjected to other tests. In addition, in the durability test, the leaf spring prototyped from the resin composition of Comparative Example 1 had fibers peeling off on the compression side. , a problem occurred in that the spring constant decreased by 1.5%.

Table 2 * 60' Slam butt 2 at 20 days L ** Fiber peeling on compression side, spring constant 1.5% decrease, *** IHz average stress 45 ”lyAm2

[Brief explanation of the drawing]

Figure 1 shows Example 4 & Kookeru E, -807 and Ep-15.
A diagram showing the relationship between the blending ratio of No. 2 and the bending strength at 00°C of the cured plate and the viscosity of the composition at 40°C. @8 Figure 1 (a) is a plan view of the leaf spring used in the test example, and Figure 3 (b) is a side view of the leaf spring in Figure 3 (a). Patent applicant Nissan Motor Co., Ltd. Figure 1

Claims (1)

[Claims] L (A) bisphenol F-type epoxy resin;
(B) 25 to 230 M per 100 parts by weight of component (A)
tm phenolic mevolac type epoxy resin and an epoxy resin having one or at least three glycidyl groups in the molecule, and (C) 0.8 to 1.0° per 1 epoxy group of the component (A+B). 2 equivalents of an acid anhydride curing agent, and ■) 0.1 parts per 100 parts of the (A+B) component.
An epoxy resin composition for filament winding, characterized in that it comprises ~5 parts by weight of a curing accelerator.