JPS645605B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a prepreg manufacturing method that simplifies the process and improves manufacturing efficiency.

Conventional methods for producing epoxy laminates can be roughly divided into two methods: dry lamination and wet lamination. In the dry lamination method, the reinforcing base material paper or fiber is impregnated with a resin solution made by dissolving the resin in a volatile solvent, and the required number of prepregs are heated and pre-cured, and then the required number of prepregs are stacked and heated and pressed using a press to form the product. is a method,
In this method, the handling of the prepreg is good because it is pre-cured and has no stickiness, but it requires a lot of heat energy to dry the solvent and pre-cure, the time required for drying is long, and the molding temperature is It also has the disadvantage of high molding pressure. On the other hand, the wet lamination method is a method in which a reinforcing base material is alternately layered with a resin solution consisting of a liquid resin and a reactive diluent, defoamed and impregnated, and then heated and molded. Although it has the advantage that the molding temperature and molding pressure are lower than the dry lamination method, the molding process is complicated, and the aging time is short, so defoaming is incomplete and air bubbles remain or impregnation occurs. It has the disadvantage of being incomplete and causing product defects.

The present inventors conducted research to solve the drawbacks of the conventional methods, and found that when electron beams were irradiated on a reinforcing base material impregnated with a resin liquid consisting of an epoxy resin, a curing agent, and an acrylate monomer, only the acrylate monomer was removed. It cures and becomes non-sticky, making it easy to handle, and since the epoxy resin is not cured in this state, it can be cured under almost the same conditions as the wet lamination method described above when molding by applying heat and pressure. They discovered this and completed the present invention.

Details of the present invention will first be explained in order about the epoxy resin, acrylate monomer, curing agent for curing the epoxy resin, and reinforcing base material used in the present invention, and then the method for producing prepreg using these materials, followed by the preparation of the prepreg. Explain how to use.

As the epoxy resin, diglycidyl ether type, epoxy novolac type, triglycidyl ether type, tetraglycidyl ether type, cycloaliphatic type, epoxidized olefin type, and halogenated epoxy type can be used, and one of the above or Use a combination of several types.

Examples of acrylate monomers include ethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, dipropylene glycol diacrylate, and dipentaerythritol. Pentaacrylate, dipentaerythritol hexaacrylate, diethylaminoethyl acrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, isodecyl acrylate, lauryl acrylate, stearyl acrylate, 2-hydroxyethyl acrylate, 2- Hydroxypropyl acrylate, trimethylolpropane triacrylate, methoxyethyl acrylate, n
-Butoxyethyl acrylate, tetrahydrofurfuryl acrylate, glycidyl acrylate, ethyl carbitol acrylate, methyl triglycol acrylate, benzyl acrylate, 1,5-pentanediol diacrylate,
Various acrylic esters such as pentaerythritol triacrylate and 2-hydroxyethyl acryloyl phosphate, as well as their corresponding methacrylic esters, can be used.
One or more types of these can be used.

As the curing agent for curing the epoxy resin described above, one or more of aliphatic amine type, aromatic amine type, cycloaliphatic amine type, acid anhydride type, dicyandiamide, boron trifluoride complex compound, etc. are used. be able to.

Paper or fiber-based materials can be used as the reinforcing base material, and examples of fiber-based materials include organic fibers such as polyester, acrylic, and polyamide, and inorganic fibers such as glass fiber, carbon fiber, and poron nitride fiber. and non-woven fabrics and woven fabrics of the above-mentioned fibers can be used.

Next, we will explain the manufacturing method of prepreg using the above materials. First, the formulation is as follows.
For 100 parts by weight of the above-mentioned epoxy resin, 20 parts by weight to 150 parts by weight of acrylate monomer, preferably 25 parts by weight to 100 parts by weight, and 2 parts by weight to 150 parts by weight of the curing agent for curing the epoxy resin.
Add parts by weight.

Other additives that can be used include surfactants, plasticizers, and colorants. For compounding, a propeller stirrer, kneader, sand mill, triple roll, etc. are used.

In the above formulation, if the acrylate monomer is less than 20 parts by weight, curing by electron beam irradiation will not be sufficient and stickiness will remain on the surface after electron beam irradiation, and if it exceeds 150 parts by weight, the thermosetting properties of the entire resin liquid will be inhibited. If a prepreg obtained with such a formulation is used, the bending strength and tensile strength of the final product will be significantly reduced, making it impractical.

The reinforcing base material is impregnated with the resin liquid having the above-mentioned composition by a known method. One example of the method is an impregnating device equipped with an impregnating head and a squeezing roller or doctor for controlling the amount of impregnation. In addition to this, a roll coater or the like may also be used. The coating material including the base material
The coating amount is 100% and can be 10% to 90% depending on the porosity of the base material and required physical properties, and preferably 30% to 90%.
50% is appropriate.

The surface of the reinforcing base material impregnated with the resin liquid is irradiated with an electron beam to the reinforcing base material impregnated with the resin liquid as described above, and the acrylate monomer in the impregnated resin liquid is cured. It becomes less sticky and easier to handle.

The electron beams used are emitted from various electron beam accelerators such as Kotscroft-Walton type, Van de Graaff type, resonant transformer type, insulated core transformer type, linear type, dynamitron type, and high frequency type.
An electron beam with an energy in the range of 1000 KeV, preferably 100-300 KeV is used. By continuously running the reinforcing base material impregnated with resin liquid and irradiating it with a continuous curtain-shaped electron beam, usually from a linear filament, the reinforcing base material impregnated with resin liquid can be continuously cured. It becomes possible.

Since the present invention has the above configuration, the acrylate monomer blended into the resin liquid is precured by electron beam irradiation, so the surface has no stickiness and is easy to handle. Since epoxy resin is essentially cured by heat when irradiated with electron beams, it is not cured at this stage, so the heating temperature and pressure during molding are the same as those for wet lamination. can be lowered,
Moreover, since the impregnation is carried out in advance using a special impregnation device, the time required for drying and electron beam irradiation after impregnation can be extended, and incomplete defoaming and impregnation, such as in the wet lamination method, can be avoided. There are no defects, and the manufacturing method of the present invention can be carried out by using the conventional process as is, changing the resin liquid, and adding an electron beam irradiation device. In addition to the above-mentioned effects, this method also provides an economical effect in that the energy efficiency of preliminary drying is better than that of the dry lamination method.

The present invention will be explained in more detail below with reference to Examples.

Example 1 100 parts by weight of bisphenol A type epoxy resin (manufactured by Ciel Chemical, Ebicoat 1001, molecular weight approximately 900),
100 parts by weight of glycidyl methacrylate (Blenmar G, manufactured by NOF Corporation), 4 parts by weight of dicyandiamide,
A resin liquid was prepared by dissolving 0.2 parts by weight of benzyldimethylamine at a temperature of 60°C to 70°C.

The above resin liquid is applied to glass woven fabric (manufactured by Nitto Boseki,
After impregnating WE18K) to an impregnation rate of 40%,
Electron beam irradiation device (manufactured by ESI, Electro Curtain)
CB200/50/30) was used to obtain a prepreg whose surface adhesiveness had disappeared by irradiation with an irradiation dose of 5 Mrad at an accelerating voltage of 175 KV.

Ten sheets of the prepreg obtained above were stacked together and heated and pressed under the conditions of 160° C. and a pressure of 70 kg/cm ² for 30 minutes using a press to obtain a laminate.

Example 2 100 parts by weight of novolac type epoxy resin (manufactured by Ciel Chemical, Epicoat 154, epoxy equivalent 176-181), 20 parts by weight of epoxy acrylate (Lipoxy 1507, manufactured by Showa Kobunshi), 20 parts by weight of dipentaerythritol hexaacrylate, A glass woven fabric (WE18K, manufactured by Nittobo Co., Ltd.) was impregnated with a resin solution containing 2 parts by weight of boron fluoride monoethylamine, and a prepreg was obtained in the same manner as in Example 1 above.

10 pieces of the obtained prepreg were stacked and heated in a press at a temperature of 150℃ for 15 minutes in contact, and then heated to 150℃.
℃ and a pressure of 50 kg/cm ² for 60 minutes to obtain a laminate.

Claims (1)

[Claims] 1. A reinforcing base material is impregnated with a resin liquid whose main components are 20 to 150 parts by weight of an acrylate monomer and 2 to 150 parts by weight of a curing agent for curing the epoxy resin based on 100 parts by weight of an epoxy resin. A prepreg manufacturing method characterized by performing preliminary curing by irradiating with a wire.