JPS5949240A - Prepreg with excellent workability and compression moldability - Google Patents

Abstract

PURPOSE:To obtain titled prepreg by using, as the matrix resin, a composition prepared by blending a specific resin and polybasic acid anhydride-cured epoxy resin composition. CONSTITUTION:The objective prepreg can be obtained by using (I) a resin composition prepared by blending (A) an epoxy resin composition prepared by incorporating (i) an epoxy resin with an average epoxy equivalent of 100-400 with (ii) a polybasic acid anhydride (e.g., phthalic anhydride) and (iii) a curing accelerator (e.g., diethylamine) and (B) an epoxy vinyl ester resin and/or unsaturated polyester resin in a weight ratio (A)/(B) of 95/5-30/70 and (II) a fibrous reinforcing material. a recommendable manufacturing process for the prepreg is as follows : a sheet material prepared by impregnating the compostion ( I ) in the material (II) at above room temperature is sandwiched in between two releasing sheets followed by aging at above room temperature to bring it to a B-stage condition.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel and useful prepreg, and more particularly to a prepreg comprising a specific curable resin and a fibrous reinforcing material as essential components, which has particularly good workability and compression moldability. Regarding prepreg that has excellent properties.

In general, epoxy prepregs made of epoxy resin and fibrous reinforcing materials such as glass fibers and carbon fibers have excellent heat resistance, chemical resistance, water resistance, adhesion, electrical properties, and mechanical properties of epoxy resins, and also harden. small shrinkage,
On the other hand, since prepreg itself is easy to handle as a molding material, it is used as a structural material for printed circuit boards, aviation, space, and axles.

Among these, epoxy prepreg for printed circuit boards mainly uses glass fiber as the substrate and epoxy resin containing solvent as the resin. Solvent-free epoxy prepregs are highly desirable in order to prevent pollution, and even when used as structural materials, epoxy prepregs can be easily impregnated into glass fibers, carbon fibers, etc.
Furthermore, epoxy resins that can be used as a matrix for FRP are desired because they can shorten the molding time.

By the way, as the solvent-free epoxy resin matrix, polyamine-cured epoxy resins, dicyandiamide-cured epoxy resin threads, dibasic acid hydrazide-cured epoxy resin threads, polybasic acid anhydride-cured epoxy resin threads, or epoxy groups cured by ring-opening are used. , so-called ring-opening polymerized cured epoxy resin threads, etc., but the requirements for the epoxy resin thread as a matrix for Gripreg are that it be uniform, that the resin be impregnated into the fibrous reinforcing phase, and that be compatible with the viscosity and have a sufficiently low viscosity;
Secondly, it has a long pot life, the prepreg itself has good stability, and the curing speed during molding of this prepreg is fast.

However, in general, among polyamine-cured epoxy resin yarns, yarns using aromatic polyamine as a curing agent have a short resin pot life and poor prepreg stability, while aromatic polyamine-cured yarns have a long pot life. However, the resin system may be non-uniform, or even if it is uniform, the viscosity may be too high, which is undesirable.

Dicyandiamide curing systems and dibasic acid hydrazide curing systems are undesirable because the curing agent and resin tend to form non-uniform threads (in addition, it is difficult to reduce the viscosity when impregnating the fibrous reinforcing phase).

In addition, with a cured yarn produced by ring-opening polymerization of epoxy groups, it is difficult to obtain a stable one-stage state and to reduce the viscosity required for impregnating a fibrous reinforcing material, which is not preferable.

Furthermore, among polybasic acid anhydride curing systems, when a liquid acid anhydride, which is widely used as a curing agent for such epoxy resins, is used, it gives a relatively low viscosity product and is uniform in composition with the resin. The curing system can be said to be preferable as a Glypreg matrix because it can be blended with the fibers and give a stable, one-stage product with a long bottle life. In order to have a sufficiently low viscosity suitable for impregnation, it is necessary to use particularly low viscosity liquid epoxy resin stocks, and high viscosity or solid epoxy resins, which are preferable from the if&* calculation. To use these low '4'+! 1lJ
In order to make L, it is absolutely necessary to use a so-called linorui diluent together, but it is possible to lower the viscosity by using such a 4ff diluent. However, on the other hand, the physical properties such as heat resistance, moisture resistance, and mechanical properties will deteriorate. 1. A resin composition with a base acid anhydride as a matrix. In general, the reaction rate is low, so the melt viscosity during heating and compression becomes too high, 1° C., resulting in the matrix flowing out and resulting in poor yield.

Moreover, the hot compression molding time also becomes long, resulting in poor productivity.

1. From the above-mentioned technical points, the Kuni IJJ researchers have developed a polybasic acid anhydride curing system, especially a solvent-free polybasic acid anhydride curing epoxy resin system, as a matrix. As a result of intensive research on Gripreg, we found that polybasic acid anhydride-cured epoxy iat++ yarn, epoxy vinyl ester lkJ fat J=;
By using the system for prepreg materials (IJ socks), conventional polybasic acid anhydride-cured epoxy resins can be
-'All the difficulties of J-lux Siripreg have been solved,
The present invention was completed by discovering that a prepreg with excellent workability, moldability, and various physical properties can be obtained.

That is, the present invention has an average epoxy equivalent of about 100 to about 4.
An epoxy resin composition made by blending a polybasic acid anhydride and a curing accelerator with an epoxy resin in the 00 number 1 surround, an epoxy vinyl ester resin and/or an unsaturated polyester resin (Bl), (N vs. (The resin composition (1) is made by blending Bl in a weight ratio of 9515 to 30/70, and the resin composition (1) is composed of a resin composition (1) with a weight ratio of 9,515 to 30/70, and a resin composition (1) containing as essential components, especially in terms of workability and heating. The Gripreg of this YJ6 Ming provides a Gripreg with excellent compression moldability, and the Gripreg of this yJ6 light contains the above-mentioned resin composition +11 as an essential 7 trix component, and the above-mentioned reinforcing material (as the river says, 1i) as another essential component. The resin (B) may be used in the form of a resin composition, which may be obtained by aging in warm or warmer summer conditions, or may be blended with a locking initiator if necessary.

Typical epoxy resins constituting the epoxy resin composition (A) in the present invention include epoxy resins obtained from epichlorohydrin or β-methylepichlorohydrin and bisphenol A, bisphenol F, or bisphenol S: phenol or Polyglycidyl ethers of alkylphenol/novolak resins; ethylene glycol, phlopylene gelicol,
polyethylene glycol, polypropylene glycol,
Neopentyl glycol, glycerin, trimethylolethane, trimethylolethane or bisphenol A
Polyglycidyl ethers of polyhydric alcohols such as ethylene oxide or globylene oxide; polyglycidyl esters of polycarboxylic acids such as adivic acid, phthalic acid, hexahydrophthalic acid or dimer acid; Aya conductor super vinegar T8i
Cyclohexene-based epoxy compounds (3,4-epoxy-6-
Methyl-cyclohexyl-6,4-epoxy-6-methylcyclohexanecarboxylate, 3,4-epoxynochlorohequinylmethyl-6,4-epoxycyclohexanecarboxylate, 1-epoxyethyl-6,4-epoxycyclohexane, etc.” , cyclopentadiene thread epoxy compounds obtained by epoxidizing cyclopentadiene or dicyclopentadiene or their visiting conductors with peracetic acid etc. (such as cyclopentadieneoxybenzyl ether), Rimoi, Diglycidyl needle to t'+6 or tetrano-1-1 mobisphenol or glycidyl ether ester of hydroxybenzoic acid, etc. Among them, those used as the epoxy resin alone have an average The epoxy equivalent is within the range of about 100 to about 400 N1tJl, or the epoxy equivalent is suitably assembled in the form of a mixture of two or more to give an epoxy equivalent within this range.

Typical polybasic acid anhydrides in the present invention include phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, and methylhegisahydride r1.
phthalic anhydride, methyltetrahydrophthalic anhydride, nadic anhydride, methylnadic anhydride, trimerisoanhydride)
9. Pyromellitic anhydride, maleic anhydride, succinic anhydride, itaconic anhydride, citraconic anhydride, totisenylsuccinic anhydride, chlorendic anhydride, benzophenonetetracarboxylic anhydride, cyclopentatetracarboxylic anhydride, 5-( 2,5-di*xochitrahydrofuryl)-
3-Methyl-3-cyclohexene-1,2-';'carboxylic acid, ethylene'glycol hysterrimellitate anhydride or glycerin trimellitate anhydride, which may be used singly or in combination of two or more. It is used in a mixed form.

Typical curing accelerators in the present invention include diethylamine, l-diethylamine, diisopropylamis monoethanolamine, jetanolamine, triethanolamine, menalecholamine, and methyljetanolamine. , monoiso7globanolamine, nonylamine, dimethylaminobutylene-11vinamine, diethylaminoprobyl'amine, α-penzyldi~■-tanolamine, 2. 4. 6-1-IJ
Sudimenal'ami,/mepurphenol or its tri-2-ethylhexylattLAa, 2-dimeglyaminomethylphenol, pyridine', hyperidine, N-aminophyllyl morpoline, 1,8-diazabicyclo(5,4,0 ) Undesen = 7-! or its salts with phenol-2-ethylhexylic acid, oleic acid, diphenylphosphorous acid, or organic phosphorous-containing amines; 2-methylimidazole, 2-isofurohylimidazole, 2-undecyl- /L/,
Cyano obtained by reacting 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, imidazole, a gold complex such as Cu, Ni or Go, and 2-methylimidazole with acrylonitrile. Ethylated ψ-type imidazoles or their adducts with trimellitic acid (imidazole H such as the reaction product with dicyandiamide; npA-monoethanolamine, BF, -benzylamine, BF3-/methylaniline, BF, -triethylamine, -B FB -n-1\xylamine,
BF3-amine complexes such as BF, -2,6-ethylaniline, BF, -aniline or BF3-piperidine: amine imide compounds starting from 1,1-dimethylhydrazine; phosphorus compounds such as nitriphenyl phosphite or octyl; Examples include organic acid metal salts such as tin acid.

Furthermore, the epoxy vinyl ester resin referred to in the present invention refers to each of the above-mentioned epoxy resins alone, such as bisphenol φ type epoxy resin or novolac type epoxy resin, and particularly to these bisphenol type or novolac type epoxy resins. The resins obtained by reacting each resin or a mixture of various types, in particular a mixture of both bisphenol type and novolac type resins, with an unsaturated basic acid as described below in the presence of an esterification catalyst. This is a resin in which an epoxy vinyl ester is dissolved in an associative vinyl monomer if necessary.

Here, representative unsaturated basic acids include acrylic acid, methacrylic acid, cinnamic acid, crotonic acid, monomethyl maleate, monopropyl maleate, motuputyl maleate, sorbic acid, and mono(2-ethylhexyl).
These include malate, which can be used alone or in combination of two or more.

The reaction between these epoxy resins and unsaturated basic acids is carried out by a conventionally known method, and if necessary, the epoxy vinyl ester resin 11 obtained in this manner can be dissolved in a conventional polymerizable vinyl monomer to form a stable resin. Typical examples of polymerizable vinyl monomers include styrene and its 94 forms such as styrene, vinyltoluene, t-7'tylstyrene, chlorstyrene, and divinylbenzene; 2-ethylhexyl (meth)acrylate , lauryl (meth)acrylate, 2-
(meth) such as hydroxyethyl (meth)acrylate or 2-hydroxypropyl (meth)acrylate
Low-boiling ester monomers of acrylic acid; or trimethylolpronotri(meth)acrylate, diethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate or 1,6-hexanediol di(meth)acrylate Examples include (meth)acrylates of polyhydric alcohols such as, and these may be used alone or as a mixture of two or more.

Furthermore, the unsaturated polyester resin referred to in the present invention is
An unsaturated polyester obtained by reacting a dibasic acid containing an unsaturated dibasic acid with a polyhydric alcohol is dissolved, if necessary, in a conventional polymerizable vinyl monomer such as those mentioned above. Typical saturated dibasic acids include maleic acid, maleic anhydride, fumaric acid, and chlorogenated maleic anhydride.Other typical saturated dibasic acids include: Futhal 1
Y! Spear, phthalic anhydride, halogenated phthalic anhydride, isophthalic acid-delefucric acid, tetrahydrophthalic anhydride,
Cono-phosphoric acid, adipic acid, sebacic acid, etc., and polyhydric alcohols such as Fri? ,C'L+('
) K ethylene glycol, diethylene glycol, triethylene glycol, furopylene glycol, cyclopylene glycol, 1,5-butylene glycol, 1,
Examples include 4-butylene glycol, neopentyl glycol, hydrogenated bisphenol A, 1,6-hexanediol, additives of bisphenol A and ethylene oxide or propylene oxide, glycerin, and trimethylolpropane.

In order to obtain unsaturated polyester 4.1↑ fat using each of these raw materials, it is best to follow a conventionally known method. When making MJ from saturated polyester resin, it is recommended to use an offshore inhibitor to prevent gelation during resin preparation and to adjust the storage stability or curability of the resulting resin. Typical offshore inhibitors include hydroquinone, p-t
- Ph'thylcatechol, 7-note -7'chillha/"Hydroquinones such as de11g, non; Hydroxy, non-monomethyl" Benzoquinone, naphthoquinone, P-)ruquinone (formerly known as Kizejinon chicken; also known as naphthenic acid).

However, both (B) component resins obtained in this manner can be sufficiently cured by simply heating without using a catalyst, but if necessary, benzoyl peroxide, p-mencunhydride, etc. Robber Ogizide,
Organic peroxides such as t-butylperbenzoate, 1,1-di-L-bunalbaroxy-3,3°5-trimethylcyclohexanone can be used as polymerization initiators, and such +'I'b'f: In t, the component (B) in the present invention can be considered as a resin composition consisting of a resin and a polymerization initiator.

Further, as the resin constituting the component (B), epoxy vinyl ester resin or unsaturated polyester resin may be used alone, or both types of resin may of course be used in combination.

and - the above-mentioned epoxy resin composition fA) comprising a polybasic acid anhydride and a curing accelerator blended with a filtered epoxy resin within a specific average epoxy equivalent weight range, and an epoxy vinyl ester resin and/or The weight ratio of the resin to the saturated polyester resin (resin composition B containing Bl, σ, and, if necessary, a polymerization initiator) may be selected as appropriate depending on the required properties and working conditions. ,
When the ratio of component (B) becomes too large, the physical properties become close to those of epoxy vinyl ester resin or unsaturated polyester resin itself, As a result, the advantage of small shrinkage is lost.

Therefore, the weight ratio of both component pairs (B) is 9515~3
A suitable range is 0/70, preferably 9515 to 70/30.

Component (A) and strength (B) may be prepared separately and then mixed together. Alternatively, component (B) may be added to the epoxy resin or polybasic acid anhydride in component (A). ) After mixing the epoxy vinyl ester resin and/or unsaturated polyester resin, if necessary, a polymerization inhibitor, and then adding the remaining component (A), the order of mixing each component compound is limited. It is not something that can be ruled out.

Further, it is also possible to add a conventional additive agent such as an internal mold release agent or a pigment to the resin composition (1) constituting the glypreg of the present invention obtained in this manner.

On the other hand, typical examples of the fibrous reinforcing material that constitutes the prepreg of the present invention include glass fiber, carbon fiber, and aromatic polyamide fiber. From the viewpoint of raw materials, there are E-glass, C-glass, A-glass, S-glass, etc. as fibers, but any type of fiber can be used in the present invention.

Next, carbon fibers include those manufactured using polyacrylonitrile fibers, cellulose fibers, pitch, aromatic hydrocarbons, or carbon blanks as raw materials, and aromatic polyamide fibers include many types. It is made from a polymer having an amide bond through the reaction of a functional aromatic amine and an aromatic polybasic acid. Typical polymers include poly-p-phenylene natrafuclamide or poly-p -Aminobenzamide and the like.

These helmets and fiber-reinforced mats (1) can be classified into roving, chopped strand mat, continuous mat, rest, roving cloth, surfing mat, and chopped strand depending on their shape, but the above-mentioned The types and shapes are appropriately selected depending on the intended use and performance of the molded article, and two or more types or shapes may be used in combination as necessary.

In obtaining the flip-preg of the present invention, the fibrous reinforcing material Q
The volume ratio of l) is suitably within the range of 50 to 70% of the prepreg.

In order to obtain the prepreg of the present invention, the reinforced fiber (1υ) is impregnated with the resin composition (I) and formed into a sheet at room temperature or a commercial temperature higher than that, and then the sheet is formed into a sheet using a release sheet. Similarly, it is preferable to ripen the product at room temperature or a higher temperature to thicken it to a B-stage state.

The prepreg of the present invention obtained by such a method is then heated and compression molded to give a desired molded product.
At this time, if necessary, after the mold is released from the mold, post-curing may be further performed.

Next, the present invention will be specifically explained using Examples and Comparative Examples. In the following, unless otherwise specified, all divisions and sections are based on weight I°.

Example 1 Epoxy resin 16 having an epoxy equivalent of 190 obtained by the reaction of bisphenol A and epichlorohydrin.
9 parts, 26.5 parts of an epoxy resin obtained by the reaction of tetrabromobisphenol A and epichlorohydrin, 26.5 parts of epoxy resin, 26.6 parts of methyltetrahydrophthalic anhydride, 0.7 parts of benzyldimethylamine, tetrabromo The epoxy obtained by the reaction of bisphenol 8 and epichlorohydrin is SZO/, +: 60 parts of an epoxy vinyl ester resin consisting of methacrylate-1 (60%) of filtered epoxy resin and styrene monomer (40%) and Kisa 3M” (NOF (1→
A resin composition was prepared by mixing 1 part and 6 parts of a polymerization initiator produced by the company. The viscosity of this product was 650 cps, and the bromine content was 20 parts.

Next, 40 parts of this σ-)4#J resin composition was soaked in 6° parts of glass cloth, and the mixture was aged at 40°C for about 30 hours to obtain a tack-free prepreg.

However, I stacked two sheets of this prepreg and copper foil and
The bamboo was heat-pressed at 160° C. for 30 minutes under a pressure of 0 parts M/cm2.

Table 1 Comparative Example 1 The physical properties of the laminate thus obtained are shown in Table 1 Comparative Example 1.
, 8 parts, 42.2 parts of an epoxy resin with an epoxy equivalent of 370 obtained by the reaction of tetrabromobisphenol A and epichlorohydrin, 67.0 parts of methyltetrahydrophthalic anhydride, and 0.6 parts of benzyldimethylamine. A resin composition was prepared by mixing.

60 parts of crow cloth was impregnated with 40 parts of the resulting resin composition with a viscosity of 2,100 cps and a bromine content of 20, and then aged at 40°C for about 40 hours to make a tack-free product. Got a pre-booreg.

Thereafter, a copper-clad laminate for comparison was obtained in the same manner as in Example 1, except that this prepreg was used.

The results of various physical properties of this laminate are shown in Table 1.

Comparative Example 2 This example uses a bromine-containing resin obtained by reacting bisphenol A, tetrabromobisphenol A, and epichlorohydrin using a solvent-based dicyandiamide-cured epoxy resin system that is commonly used for flame-retardant printed circuit boards. Methyl ethyl ketone *i of epoxy resin with a ratio of 21 qb and an epoxy equivalent of 485 (non-volatile content = 801)
A resin composition was prepared by mixing 125 parts of 125 parts of acetone, 34 parts of acetone, and a curing agent solution obtained by bath dissolving 4 parts of dicyandiamide and 0.2 parts of dimethylbenzylamine in 60 parts of methyl cellosolve. I got it.

Next, a preg was obtained by impregnating glass cloth with this resin composition.

Thereafter, a copper-clad laminate was obtained in the same manner as in Example 1, except that the heating compression time was changed to 1 hour and the prepreg of this example was used.

Table 1 shows the physical properties of this laminate.

Example 2 An epoxy resin with an epoxy equivalent of 190 obtained by the reaction of bisphenol A and epichlorohydrin
00 parts, 87 parts of methyltetrahydrophthalic anhydride and 1 part of benzyldimethylamine, and separately phenol.
46 parts of an epoxy vinyl ester resin consisting of methacrylate (70%) of an epoxy resin with an epoxy equivalent of 182 obtained by the reaction of a novolak resin and epichlorohydrin and a styrene monomer (60%), and Next, 30 parts of this resin composition was impregnated into 70 parts of carbon fiber roving to form a unidirectional sheet-like material, and then heated at 40°C. Gripreg was obtained by aging for about 40 hours.

After that, 6 sheets of this Gripreg were molded under heat and pressure m (50 to 9/crl, 160°/6 minutes).
Post-curing was carried out in an electric dryer at 170'C for 1 hour.

Next, the physical properties of the molded product obtained were as follows.

Bending strength: 192 Y/am" Flexural modulus: 13.600 // Interlaminar shear strength: 92 Tensile strength: 188 Tensile modulus: Example 6 40 parts of the resin composition obtained in Example 2 were cut to a length of 1
After impregnating it into chopped strand glass of 1.5 inches, it was aged at 40° C. for about 60 hours to obtain a tack-free and bendable prepreg having a hardness of 75 to 85 on the Shore A hardness side.

Thereafter, molded products were obtained in the same manner as in Example 2, except that this prepreg was used.

Next, the physical properties of this molded product were evaluated according to JIS standards, and the results are shown in Table 2.

Comparative Example 6 Novolac type epoxy resin methacrylate obtained from phenolic novolac resin and epichlorohydrin, styrene monomer and 1 perhex 3M
A resin composition was prepared in the same manner as in Example 2, except that no use of .

Next, 40 parts of this resin composition was impregnated into 60 parts of chopped strand glass having a cut length of 1 inch, and then aged at 40°C for about 40R to obtain Shore A.
A tack-free and bendable grip preg having a hardness of 75 to 85 on a mold hardness tester was obtained.

Thereafter, molding was carried out in the same manner as in Example 6 except for using this comparative prepreg, but there was a lot of matrix flowing out (and there were many bubbles left in the molded product). Furthermore, the molded product deformed during cooling to room temperature after being released from the mold, and was not suitable for evaluation of physical properties.

Example 4 An epoxy resin with an epoxy resin of 190 obtained by the reaction of bisphenol A and epichlorohydrin
00 parts, 87 parts of methyltetrahydrophthalic anhydride, 1 part of benzyldimethylamine, [Polylite FG387
A resin composition was obtained by mixing 33 parts of J (unsaturated polyester resin manufactured by Dainippon Ink & Chemicals Co., Ltd.) and 07 parts of 1 Per Hexa 3MJ.

Next, 60 parts of chopped strand glass having a cut length of 1 inch was impregnated with 40 parts of this resin composition, and a molded article was obtained in the same manner as in Example 2.

Table 2 shows the physical properties of this molded product.

Example 5 After impregnating 40 parts of the resin composition obtained in Example 3 into 60 parts of a continuous mat of glass fibers,
A prepreg was obtained by aging at 0°C for about 40 hours.

Next, a molded product was obtained in the same manner as in Example 2 except that six sheets of this prepreg were used.

The physical properties of this molded product were as follows.

Volume resistivity <5X10”Ω・α Bending strength: 52 to 97 2

Claims (1)

[Scope of Claims] (11) Epoxy 4(l) having a polybasic acid anhydride and a curing accelerator blended with a polybasic acid anhydride and a curing accelerator: L boxy resin composition ( A) and the epoxy vinyl ester resin and/or the unsaturated polyester resin (B), the amount ratio of (A) to (13) 2IL is 9.515 to 30/7.
A prepreg that is excellent in workability and compression moldability, and comprises as essential components a Resin Hikari 11 composition which is blended so as to have a composition of 0 and (II) a fibrous reinforcing material.