JPS6368626A - Resin composition for prepreg - Google Patents

Abstract

PURPOSE:To obtain the title composition which can give a cured product excellent in heat resistance, water resistance and toughness, by mixing a polyepoxy compound with a cyanate resin, a polysulfone resin and a specified sulfonic compound. CONSTITUTION:100pts.wt. mixture formed by mixing a polyepoxy compound (A) having at least two epoxy groups in the molecule with a cyanate ester resin (B) comprising a polycyanate having at least two cyanato groups in the molecule or a mixture thereof (a) with its prepolymer at an A to B ratio of 9-2:1-8 is mixed with 6-60pts.wt. polysulfone resin (C) which is a polyallyl ether sulfone of formula I (wherein Ar is any one of formulas II-V and n>=1) and 1-40pts.wt., per 100pts.wt. component A, sulfonic compound (D) of formula VI (wherein n and m are each >=1 and R is H or CH3).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel resin composition for prepreg. The cured resin product obtained by the present invention has excellent heat resistance, water resistance, and toughness, and is particularly good for fiber-reinforced plastics (hereinafter referred to as F
It is suitable as a matrix resin for prepregs (abbreviated as RP).

[Prior Art] Among thermosetting resins, epoxy resins are widely used in various industrial fields due to their excellent mechanical properties. In particular, epoxy resins are often used in advanced composite materials made of reinforcing fibers such as carbon fibers, glass fibers, and aramid fibers and matrix resins. However, the epoxy resins used in these composite materials still have some unsatisfactory points, and their uses and methods of use have been limited. One of them is heat resistance and water resistance. Various curable resins other than epoxy resins have conventionally been used as matrix resins to improve heat resistance and water resistance. Among these, cured products of cyanate ester resins have been known to provide cured products with excellent heat resistance and water resistance. However, since these cured products are brittle and have poor toughness, advanced composite materials using them as matrix resins lack impact resistance and have the drawback of not being able to fully develop the strength of reinforcing fibers.

Therefore, various studies have been made to improve the toughness of these cured products. For example, meta(
Those containing modified butadiene-based resins with introduced (acryloyl) groups (JP-A-57-153045), those containing a butadiene-acrylonitrile copolymer (JP-A-57-153045);
7-153046), or those in which epoxy resin is further added (JP-A-56-157424.56-
157425> etc. are known. However, all of these methods inevitably suffer from a decrease in heat resistance and water resistance.

As a method for solving these problems and improving the toughness of cured products without deteriorating heat resistance and water resistance, a resin composition containing polysulfone resin was published in Japanese Patent Application Laid-Open No. 57-16545.
1, a resin composition in which an epoxy resin was roughly added to these was proposed as JP-A-60-250026.

These resin compositions have improved toughness of the cured product by adding polysulfone resin, and the polysulfone resin alone has better heat resistance and water resistance than the above-mentioned butadiene resin. The cured product has excellent physical properties with little deterioration in heat resistance and water resistance.

However, polysulfone resin is highly dispersed in these cured products, and since polysulfone resin is a thermoplastic resin, it dissolves in halogenated solvents, so these cured products have a serious drawback of poor solvent resistance. .

As a result of studies by the present inventors, when epoxy resin compositions containing polysulfone resin were cured using various curing agents, some were uniformly dissolved and cured as they were, while others did not dissolve uniformly and were finely dispersed even after phase separation. It was found that there were almost no problems with solvent resistance.

However, when cyanate ester resin is used, even if it is uniformly dissolved, the thermoplastic resin undergoes phase separation during the curing process, and the final cured product is often unsatisfactory because it is not finely dispersed and has poor solvent resistance. I could only get something.

[Problems to be Solved by the Present Invention] The purpose of the present invention is to achieve a fine dispersion state even when a polysulfone resin is added to a cyanate ester resin in order to improve the toughness of the cured product, resulting in improved solvent resistance. An object of the present invention is to provide a resin composition for prepreg.

[Means for Solving the Problems] As a result of intensive studies, the present inventors have determined that the dispersion state of the polysulfone resin in the cured product can be improved in cyanate ester resins to which polysulfone resin has been added in order to improve the toughness of the cured product. By adding a sulfone-based compound having a specific chemical structure for improvement, it becomes a finely dispersed state and improves solvent resistance, making it possible to provide a resin composition for prepregs that has excellent heat resistance, water resistance, and improved toughness. The inventors have discovered that the present invention is possible.

It was found that the sulfone compound having this specific chemical structure also has the effect of improving the toughness of the cyanate ester resin alone, and together with the effect of adding the polysulfone resin, it greatly improves the toughness of the resin composition of the present invention. It was found that it contributed.

That is, in order to quickly achieve the above object, the present invention consists of the following configuration.

Prepreg resin composition A containing at least the following components; polyepoxy compound B having at least two or more epoxy groups in one molecule; dianic acid ester resin C; polyether sulfone resin D; A sulfonic compound having the specific chemical structure shown: n, m: an integer of 1 or more R: H or CH3 Most polyoxy compounds used in the present invention can be used without any limitations. In particular, to give an example,
Epicote 828. Liquid or solid bisphenol A epoxy resins such as Epicoat 1001 (manufactured by Yuka Shell Epoxy Co., Ltd.), DER-331 (manufactured by Dow Chemical Japan Co., Ltd.), ELM434. >, MY-72
0 (manufactured by Ciba Geigy), bisphenol F-type epoxy resin such as Evicron 830 (manufactured by Dainippon Ink & Chemicals), Epicort 152. Phenol novolac type epoxy resin such as Epicote 154 (manufactured by Yuka Shell Epoxy Co., Ltd.), brominated bisphenol A type epoxy resin such as Ebicuron 152 (manufactured by Dainippon Ink Chemical Industry Co., Ltd.), ESC
Examples include cresol novolac type epoxy resin such as N-220 (manufactured by Sumitomo Chemical Co., Ltd.), other bisphenol S type epoxy resins, and alicyclic epoxy resins.

These polyepoxy compounds may be used alone or in a mixture of several types without any problem. However, since the resin viscosity increases when a thermoplastic resin is added, if a large amount of M is added, use a low-viscosity, liquid bisphenol A epoxy resin such as Epicoat 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) or Evicron 830 (manufactured by Dainippon Ink Co., Ltd.). Bisphenol F type epoxy resins such as those manufactured by Kagaku Kogyo Co., Ltd.) are suitable.

The polyfunctional cyanate esters in component B are metal compounds having two or more cyanate ester groups, and preferred cyanate esters are compounds represented by the following general formula (1).

R-(-0-C2N) (1) (in the formula, m is an integer of 2 or more and 6 or less, R is an aromatic organic group, and the above cyanate ester group is bonded to the aromatic ring of the organic group R) Specifically, dicyanatobenzene, tricyanatobenzene, dicyanatonaphthalene, tricyanatonaphthalene, dicyanatobiphenyl, bis(cyanatophenyl)methane, Bis(cyanatophenyl)propane, bis(cyanatophenyl)
Examples include ethers, bis(cyanatophenyl)sulfones, and cyanic acid esters obtained by reaction of novolacs with cyanogen halides. It can also be used as a prepolymer obtained by polymerizing these polyfunctional cyanate esters in the presence of a catalyst such as a Lewis acid, sodium carbonate, or lithium chloride.

Moreover, the polyfunctional maleimide ticket is a compound represented by the following general formula (2).

It is an aliphatic organic group, x and X are hydrogen, halogen, or an alkyl group, and n is an integer of 2 or more and 6 or less.

) The maleimide represented by the above formula can be obtained by reacting maleic anhydride with a polyamine having 2 to 6 amino groups to prepare maleamic acid, and then performing a dehydration reaction. The polyamines to be used are preferably aromatic polyamines in terms of heat resistance, but aliphatic amines may be used if flexibility and softness are desired to be imparted to the resin. Suitable amines include:
Examples include phenylene diamine, xylylene diamine, cyclohexane diamine, diaminodiphenyl, diaminodiphenylmethane, diaminodiphenyl ether, diaminodiphenyl sulfone, and the like. Also used are condensation products of maleimide and these amines.

The mixing ratio of component A and component B varies depending on the type of compound used, but generally A:B is 9:1 to 2:8.
is within the range of

The amount of the polysulfone resin (C component) to be added is preferably about 6 to 60 parts per 100 parts by weight of the polyepoxy compound (A component) and the cyanate esters and maleimides (B component). When this happens, the tuck and drape of the prepreg deteriorates.

The sulfone-based compound having a specific chemical path of component D is as shown below at maximum, n, m; an integer of 1 or more R; ) It can be produced by adding ethylene oxide or propylene oxide to sulfone.

The amount of component D added is preferably about 1 to 40 parts per 100 parts by weight of the polyepoxy compound used.If it is less than this, the effect of addition will be small, and if it is more than this, the heat resistance of the cured product will deteriorate.

The method of mixing the components of the present invention is not particularly limited, and a preferred method can be selected as appropriate depending on the shape of each component and the mixing state or dispersion state of the intended blend. One example of a mixing method is to use a solvent that dissolves each component to form a homogeneous solution.Another example is to dissolve the polyepoxy compound and thermoplastic resin at a relatively high temperature without using a solvent, and then lower the temperature. There is a method of adding cyanate esters and maleimides.

Especially when the resin composition of the present invention is used as a matrix resin for FRP prepreg, it becomes a useful epoxy resin composition that provides a prepreg with excellent tack and drape properties, good moldability, and high toughness. However, as reinforcing fibers, carbon fibers, glass fibers, aramid fibers, boron fibers, or hybrids thereof can be used. Moreover, any shape can be used, such as a tape arranged in a certain direction, a sheet-like material, a mat-like material, a woven material, etc.

Furthermore, various additives such as fillers, curing accelerators, and diluents can be used within the range that does not impair the properties.

[Function] In the present invention, in order to improve the toughness of the cured product, a sulfone compound having a specific chemical tf4 structure is added to the cyanate ester resin to which a polysulfone resin is added in order to improve the dispersion state of the polysulfone resin in the cured product. This has made it possible to provide a resin composition for prepregs that is in a finely dispersed state, does not have poor solvent resistance, is excellent in heat resistance and water resistance, and has improved toughness.

[Example] The invention is further illustrated by the following examples.

The amounts of each component in the examples represent the heavy industry, and the contents of the resin are as follows.

Epoxy resin; Bisphenol A type epoxy resin, Epicoat 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) BT resin,
2. Preliminary reaction product of 2'-bis(4-cyanatophenyl)propane, BT-2160RX <manufactured by Mitsubishi Gas Chemical Co., Ltd.) Example 1 Polyether sulfone VICT'REX100P having the following chemical path for epoxy resin 100 heavy engineering section (1
, C, manufactured by I) 20 parts -+@;/-0 () SO Institute of Technology and the following chemical t%m sulfonic compound manufactured by Nikka Chemical Co., Ltd. 5EO-2) 10 parts HO-CHz C'rh-0+Sh+ '−”−〇4”
' was heated and stirred at 150°C, and a clear viscous liquid was obtained after 30 minutes. This mixture was cooled to 80°C and the BT resin 2
00 parts were added to obtain a resin composition. This resin composition was cast and cured at 180°C for 2 hours to obtain a cured product.

The glass transition temperature (Tg) of this cured product was measured with a differential scanning calorimeter and was 198°C, indicating that it was a cured product with high heat resistance.

Further, this cured product was immersed in methylene chloride and left for one day, but no change occurred.

Example 2 The following chemical m? instead of SEO-2 A resin composition was obtained in the same manner as in Example 1 except that a sulfone compound having A cured product was obtained.

When the glass transition temperature (Tg) of this cured product was measured using a differential calorimeter, it was 195°C, indicating that the cured product had high heat resistance.

I also soaked this cured product in methylene chloride and left it for a day, but there was no change.

Comparative Example 1 A resin composition was obtained in the same manner as in Example 1 except for the step of adding 5EO-2. This resin composition was cast and cured at 180° C. for 2 hours to obtain a cured product.

When the glass transition temperature (Tr) of this cured product was measured using a differential scanning calorimeter, it was 202°C, indicating that the cured product had high heat resistance as in Example 1.

However, after soaking this cured product in methylene chloride and leaving it for one day, the surface turned white and began to crumble from the surface.

Comparative Example 2 A resin composition was obtained in the same manner as in Example 1 except for the step of adding polyether sulfone. This resin composition was cast and cured at 180°C for 2 hours to obtain a cured product.

When this cured product was immersed in methylene chloride and left for one day, no change was observed as in Example 1.

Example 3 The resin composition obtained in Example 1 was heated to lower its viscosity and stretched thinly onto paper that had been subjected to release treatment with silicone to produce a resin film. Next, carbon fiber trading card T-800
(manufactured by Toshisha Co., Ltd.) were aligned in one direction and placed on a resin film, heated and pressurized to obtain a prepreg. The obtained prepreg had appropriate tuck drape and was of good quality.

This prepreg was laminated in a quasi-isotropic manner with a composition of (+45/90/-4510) 48, and 6k1 was laminated using an autoclave.
A composite was obtained by molding under the conditions of 3f/aK and 180°C for 2 hours.

680'q with a weight of tip radius 16mm on this composite
It gave a falling weight lightning energy of cx/cm. When the damage caused by this impact test was measured using an ultrasonic flaw detection imaging device (manufactured by Canon-Holosonic), the damage area was 18.8o+f.

Comparative Example 3 A prepreg was prepared and a composite was obtained in the same manner as in Example 3 except that the resin of Comparative Example 2 was used instead of the resin of Example 1.

Furthermore, when a street rail test was conducted in the same manner as in Example 3, the damaged area was 44.6 oyf.

Claims (1)

[Claims] 1. A prepreg resin composition A containing at least the following components; a polyepoxy compound B having at least two epoxy groups in one molecule; a cyanate ester resin C; a polysulfone Resin D: A sulfone compound with a specific chemical structure represented by the general formula below ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ n, m: An integer of 1 or more R: H or CH_3 2. The polysulfone resin of the C component is as follows. The resin composition for prepregs described in claim 1, which is polyallylether sulfone represented by the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Ar: ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ , ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ n: An integer of 1 or more 3, B component cyanate ester resin (a) A mixture of polyfunctional cyanate esters containing two or more cyanato groups in the molecule or a prepolymer thereof, or a polyfunctional maleimide containing the above (a) and two or more maleimide groups in the molecule. or a resin composition for prepreg according to claim 1 comprising a mixture thereof with a prepolymer.