JPH0214927B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin composition for making fiber-reinforced plastics, particularly to a resin composition for fiber-reinforced plastics using inorganic reinforcing fibers such as carbon fibers and glass fibers.

Generally, fiber-reinforced plastics (hereinafter abbreviated as FRP) are manufactured using filament winding,
Molding methods that use intermediate materials such as SMC and prepreg are increasingly being adopted as an alternative to hand lay-up and spray-up molding methods.

By the way, thermosetting resins such as unsaturated polyester resins, epoxy resins, and phenolic resins have a good balance between performance and price as fiber-reinforcing resins used in the production of SMC and prepreg, and are especially popular. Unsaturated polyester resins, which can be cured quickly, are widely used.

On the other hand, the quality required for intermediate materials such as prepreg and SMC is not only excellent physical properties of FRP, but also workability and handling. Conventionally, when unsaturated polyester resins are used as reinforcing resins, the tack is adjusted by changing the amount of crosslinking monomers such as styrene and vinyltoluene diallyl phthalate, but these crosslinking monomers are volatile. FRP has a strong odor and deteriorates the working environment, and also has a large curing shrinkage. Especially when reinforced with fibers such as carbon fiber, which hardly expand or contract slightly when heated (hereinafter referred to as CFRP). ), it has the disadvantage that cracks are likely to occur in the molded product.

The present inventors have developed a CFRP resin that maintains the advantages of unsaturated polyester resins, such as fast curing properties, heat resistance, and good physical performance, while improving workability and handling properties, which are the disadvantages mentioned above. As a result of intensive studies on fiber-reinforced resin compositions that provide the following, the present invention was completed by discovering a method of using an aliphatic low molecular weight compound having at least two allyl ether groups in one molecule as a crosslinking monomer.

The gist of this is: [A] Unsaturated polyester resin and/or vinyl ester resin [B] Trimethylolpropane, glycerin, trimethylolethane, pentaerythritol,
An aliphatic low molecular weight compound obtained by allyl etherifying at least two or more alcohol groups of a polyhydric aliphatic alcohol consisting of 1,4-butanediol and 1,3-butylene glycol [C] Consisting of an organic peroxide as an essential component A resin composition for reinforcing carbon fibers.

Known resins can be used as the unsaturated polyester resin and vinyl ester resin used as component [A] of the present invention, and are not particularly limited. In order to impregnate the resin, it is preferable to select and use one having a weight average molecular weight of 10,000 or less.

The aliphatic low molecular weight compound having at least two or more allyl ether groups in one molecule of component [B] to be blended into the unsaturated polyester resin and/or vinyl ester resin includes allyl chloride and aliphatic polyhydric alcohol, for example. , trimethylolpropane, glycerin, pentaerythritol, diglycerin, dipentaerythritol, etc., and specific examples include trimethylolpropane diallyl ether, trimethylolpropane diallyl ether, and glycerin diallyl ether. , glycerin triallyl ether, trimethylolethane diallyl ether, trimethylolethane triallyl ether,
Pentaerythritol triallyl ether, pentaerythritol tetraallyl ether, 1,4
-butanediol diallyl ether, 1,3-butylene glycol diallyl ether, and the like. Among these low molecular weight compounds, trimethylolpropane diallyl ether and/or trimethylolpropane triallyl ether are particularly useful for improving workability, handling properties, and
It has excellent physical properties compared to FRP.

The blending ratio of [A] component and [B] component is [A]
Although it varies depending on the type and molecular weight of the component resin, the type of component [B], whether or not a third component is added, and the method of impregnating or molding the reinforcing fiber, from the viewpoint of handling and workability of the intermediate material, etc. It is preferable that the viscosity of the blended resin containing no organic peroxide, solvent, and component [C] be within the range of 10 to 200 poise at 90°C.

[C] The organic peroxide of the component is 2,5-
Dialkyl peroxides such as dimethyl-2,5-di(tertiary butylperoxy)hexane, ditertiary butyl peroxide, and cycumyl peroxide, 1,1-bis(tertiary butylperoxy) 3,3,5- Peroxy ketals such as trimethylmicrohexane and 2,2-bis(tert-butyl peroxy)butane, peroxy esters such as tert-butyl perbenzoate and tert-butyl peroxy (2-ethylhexanoate), and benzoyl peroxy. Examples include dialperoxides such as oxides, and these are suitably used in an amount of 1 to 10 parts by weight per 100 parts by weight of the sum of components [A] and [B], either alone or as a mixture of two or more.

The resin composition of the present invention has its intended use,
Various inorganic fillers,
An internal mold release agent, pigment, etc. may be added. Also,
The fibers to be impregnated with the resin composition include various types.
FRP fibers are used, but carbon fibers are particularly effective.

Hereinafter, the present invention will be explained in more detail with reference to Examples. In the examples, "parts" means parts by weight.

Example 1 150 parts of unsaturated polyester resin "Polylite" PS-204 manufactured by Dainippon Ink and Chemicals Co., Ltd. and Osaka Soda
After heating and mixing 10 parts of diallyl phthalate prepolymer "Daiso Tap" L manufactured by Co., Ltd. and 25 parts of a mixture of trimethylolpropane diallyl ether and trimethylolpropane diallyl ether (containing 70% by weight of trimethylolpropane diallyl ether), The solvent component (toluene and acetone each containing 15% by weight) contained in Polylide"PS-204 was removed under reduced pressure. Next, 4 parts of di-t-butyl peroxide was added to the mixture to obtain a resin composition. The resin composition was coated on a release paper using a film coater, and carbon fiber (Pyrofil AS-6K manufactured by Mitsubishi Rayon) was coated on this.
was introduced in one direction at regular intervals and hot-pressed through multistage rolls heated to 120°C to impregnate the fibers with resin to produce a unidirectional sheet-like prepreg. The obtained prepreg had appropriate tack and drape properties, had almost no odor, and had a shelf life of 3 months or more at 20°C, indicating that it was a good prepreg. Therefore, the physical properties of CFRP, which was formed into a 2 mm thick plate by laminating this prepreg in one direction and curing at 150° C. for 30 minutes at 7 kg/cm ² , were as follows.

Bending strength 165Kg/ ^mm2 Bending modulus 12.5ton/ ^mm Interlaminar shear strength 8.9Kg/ ^mm2Fiber volume content 60% Comparative example 1 Crosslinking monomer of Example 1, trimethylolpropane diallyl ether and trimethylolpropane triallyl ether A prepreg was produced in the same manner as in Example 1 except that diallyl phthalate was used instead of the mixture. The tack, drapability, and shelf life of the obtained prepreg were almost the same as those of the prepreg of Example 1, and no differences were observed. However, the prepreg produced by this method had a strong odor of diallyl phthalate, and was molded to a thickness of 15 mm under the molding conditions shown in Example 1.
It was observed that CFRP had many cracks inside. On the other hand, no cracks were observed inside the 15 mm thick molded plate prepared under the same conditions using the prepreg of Example 1.

Claims (1)

[Claims] 1 [A] Unsaturated polyester resin and/or vinyl ester resin [B] Trimethylolpropane, glycerin, trimethylolethane, pentaerythritol,
An aliphatic low molecular weight compound obtained by allyl etherifying at least two alcohol groups of a polyhydric aliphatic alcohol consisting of 1,4-butanediol and 1,3-butylene glycol [C] Compounded with an organic peroxide Resin composition for reinforcing carbon fibers. 2. The carbon fiber reinforced resin composition according to claim 1, wherein trimethylolpropane diallyl ether and/or trimethylolpropane triallyl ether is used as component [B].