JPH0579485B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a sheet-shaped resin composite material for molding consisting of a resin and a fiber base material. More specifically, glass fiber base materials such as chopped strand, pine and cloth, carbon fiber base materials, natural fibers such as cotton and linen, and synthetic fibers such as polyester, polyamide, and polyvinyl alcohol are used. Regarding the method of producing a sheet-like resin composite material for molding by impregnating one or more selected types of fiber base materials such as organic fiber base materials with a liquid resin or a resin mixture, in particular, The invention relates to a technique for promoting impregnation of resin into a fiber base material and defoaming in the process of laminating a mixture of material and resin on one side of a release sheet and then winding it up into a roll with the laminate inside, for example. The purpose is to provide a high quality, high performance molding material for resin/fiber composite products (hereinafter referred to as FRP), that is, prepreg, which has a high content of fiber base material and has no or few bubbles. .

[Conventional technology]

Conventionally, SMC was used as a sheet-shaped FRP molding material.
(sheet molding compound) is known.
For example, there are rubber belt type and mesh belt type machines for this production.The former places a laminate of liquid resin and fiber base material sandwiched between two release films on a flat rubber belt, and then By pressing the laminate with a plurality of flat rolls or striped rolls along the mesh belt, forces such as compression, shearing, and stretching are applied to the laminate to promote impregnation. is added to further promote impregnation. Incidentally, since SMC generally contains powder/granular filler at a high concentration in addition to liquid resin and fibers, the viscosity of the mixture of liquid resin and filler during impregnation is quite high, for example, 100 poise or more. In order to obtain enough force to impregnate the fiber base material with this highly viscous system, it is necessary to increase the pressure of the rolls. However, as the resin is pressed, it generally flows and tends to flow in the lateral direction of the sheet. In SMC, the upper and lower release films that sandwich the laminate prevent this resin from flowing out.

[Problem that the invention seeks to solve]

The technical problem addressed by the present invention is to complete impregnation of a fiber base material in the form of chopped strands, mats, or cloth in a short time with a liquid resin having a relatively low viscosity of 0.8 to 50 poise. It's about how to do it. In other words, the impregnation method seen in the production of SMC mentioned above has a low viscosity and does not cover the upper side with a release film like the system of the present invention, so if the pressure for impregnation is high, the liquid resin will leak out. To prevent this, the pressure may be lowered or the grooves may be deep.
If you use a special muscle roll with a wide width, the force for impregnation will be offset accordingly.

Therefore, it is necessary to find another method to replace this type of impregnation method using an impregnation roll, or to find a method to supplement this impregnation roll method to enhance the impregnation effect.

[Means to solve the problem]

As a result of intensive investigation into the limitations and problems of the application of the prior art as described above, the present inventors found that a continuous impregnation method for sheet-shaped resin composites is both novel and relatively mechanical. The inventors have discovered that the desired objective can be achieved by attaching a simple device to a conventional machine, and have arrived at the present invention.

That is, the present invention provides a device using a conventional impregnating roll, in which a movable plate is provided below the release sheet and in contact with the release sheet for conveying a laminate of liquid resin and fiber base material, and the movable plate is connected to a vibrator. By vertically vibrating the laminate, especially liquid resin, pulsation of arbitrary frequency and amplitude is applied. In other words, the effect is that the pressure of the upper impregnating roll on the laminate is pulsated, and the resulting local liquid flow, that is, the vibration in the thickness direction of the laminate, promotes impregnation.

[Effect]

The problem with this method is how much vibration to apply. It is generally known that when vibrating (shaking) a viscous liquid, the loss rate increases as the vibration frequency increases. On the other hand, the higher the frequency of the liquid, the higher the frequency of local flow of the target liquid, and therefore there is a suitable limited range of the frequency of the external vibrational stress. The amplitude should be adjusted in consideration of the thickness of the laminate of the present invention.
When it is 0.1 to 1.0 mm, a suitable vibration frequency is 1 to 20 Hz.

This vibration is generated by a commercially available oscillator (vibrator)
Alternatively, it can be realized by adding an inverter (frequency converter) to adjust the vibration frequency.

The vertical vibration according to the present invention is transmitted to the laminate through the release paper, and gives pulsations to the pressing of the laminate by the plurality of impregnating rolls fixed at the top. As a result, the effects of kneading, impregnation, and defoaming by compression, shearing, etc. that the impregnating roll originally has are dramatically promoted.

Hereinafter, the present invention will be explained using figures.

An example of the liquid resin/fiber base material composite manufacturing apparatus of the present invention is shown in the figure. In this figure, two vibrating parts are shown, but the number of vibrating parts is not specified. A vibrator 4 is connected to a movable plate 5, and the vibrations of the vibrator 4 are directly transmitted to the movable plate 5. The release sheet 2 moves at a constant speed on a flat stainless steel fixed plate and a movable plate, but is subjected to vertical movement on the movable plate. The liquid resin/fiber base material composite laminate (chipped strand mate) 1 also moves in the same way, and the impregnation roll 6 installed on the upper part of the movable plate 5
It is subjected to pulsating pressure. This impregnation roll 6
The type, size, and number of the plates are not specified, and they may be placed not only on the movable plate but also on the fixed plate. The frequency of oscillation by the vibrator 4 is 1 to 20 Hz, preferably 3 to 10 Hz. At frequencies lower than this range, there is little effect, while at higher frequencies vibration loss is large and efficiency is low. The amplitude is 0.1 to 1.0 mm, preferably 0.2 to 0.5 mm, taking into account the thickness of the laminate and the pressing effect of the impregnated roll.

The sheet-shaped molding material that has undergone the impregnation process and leveling is continuously wound up with a take-up roll 7 with the release sheet facing outside, or is cut into a regular length.

It is advantageous to use a release sheet that has been subjected to release treatment on both sides as the release sheet used here, since the molding material can be easily peeled off during use even when the sheets are rolled up or stacked.

The resin that is the main component of the FRP molding material that is the object of the present invention is a thermosetting oligomer or its reactive diluent solution, and the viscosity of the additives and mixtures thereof, excluding the fiber base material described below, is The liquid is at most 50 poise, preferably 20 poise or less. Suitable examples include thermosetting oligomers classified as unsaturated polyester resins, vinyl ester resins, epoxy resins, diallyl phthalate resins, or phenol resins, and solutions obtained by diluting these with reactive low-molecular organic compounds, Furthermore, a curing reaction catalyst, a curing reaction accelerator, and if necessary, a viscosity modifier, a wetting agent, etc. are added. More specifically,
Taking an unsaturated polyester resin system or a vinyl ester resin system as an example, each basic oligomer or a solution of this diluted with a reactive unsaturated compound such as styrene, diallyl phthalate, or acrylate ester is heated and cured. If you are aiming for UV curing, add an appropriate amount of an organic peroxide catalyst, or if you are aiming for ultraviolet curing, add an appropriate amount of photosensitizer, and if necessary, add a thickener such as magnesium oxide or polyisocyanate. and mix. The viscosity of the mixture is below 50 poise under working conditions, preferably between 1 and
20 poise is suitable for production according to the invention.

Neither the material nor the form is specified as the fiber base material, but chopped strands or organic fibers such as glass fiber, carbon fiber, and organic fibers such as polyester, polyamide, polyvinyl alcohol, and cellulose, which are widely used in FRP, are used as fiber base materials. Short fibers, mats made from them, long fiber mats, and various cloths are used.

The method of laminating the liquid resin and the fiber base material is not particularly limited, and various coating techniques can be applied. Among these methods, if the fiber base material is cloth or long-fiber pine, an impregnating coating method is used in which the fiber is passed through a liquid resin bath, or more generally, a liquid resin is applied to a certain thickness on a release paper using a knife coater, etc. A method is used in which fiber base materials are laminated on top of each other.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to Examples.

Example 1 Unsaturated polyester resin (Rigorac M411,
Polystyrene (S-Bright #8, manufactured by Showa Denko) as a low shrinkage agent for 100 parts of Showa Kobunshi (manufactured by Showa Kobunshi)
4 parts, 1.2 parts of t-butyl perbenzoate (Perbutyl Z, manufactured by NOF Corporation) as a curing catalyst,
Magnesium oxide (Magumitsuku,
2 parts of Kyowa Chemical Industry Co., Ltd.), 2 parts of zinc stearate as a mold release agent, 10 parts of calcium carbonate (Softon 1200, Bihoku Chemical Co., Ltd.), and an appropriate amount of styrene monomer. After stirring and mixing in a mixer, the mixture was transferred to a vacuum tank and preliminarily defoamed to prepare a liquid resin mixture having a viscosity (B-type viscometer) of 18 poise at room temperature.

It has a flat section with an effective width of 600 mm and an effective length of 2,500 mm between the raw material supply section and the sheet winding section on which a roll for impregnation can be installed. We have created a machine with a drive mechanism that allows the release sheet to move at a constant speed.
The flat plate that constitutes the effective plane is made of stainless steel with a thickness of 3 mm, and extends approximately 200 mm and 1300 mm from the upstream part.
There are two rectangular movable plates each 500mm wide and 700mm long, and the rest are fixed plates. The movable plate is integrally connected to the diaphragm of the vibrator. The vibrator is mounted on a small jack.

The vibrator was a commercially available machine with a vibration force of 150 kgf and an output of 65 W, and an inverter was connected to the front to adjust the frequency. The vibration used had a frequency of 5Hz and an amplitude
It was 0.3mm.

Above the movable plate, a total of six muscle rolls, three each having an outer diameter of 35 mm, were attached. In addition, two strip rolls of the same type were attached to the downstream stationary plate. The pressure of each of these rolls was adjusted by a spring at the top. The degree of pressure was determined based on the bank of resin liquid formed in front of the roll.

The outline of the apparatus of this example is shown in the figure. Double-sided release sheet (Fujimori Industries Binasheet 80XT, width 500
mm) moves at a constant speed (approximately 2 m/min), the above liquid resin mixture is laminated to a width of 350 mm on the release sheet using a knife coater (clearance approximately 1 mm), and chopped strand pine (Asahi After the fiberglass (CM305, width 500mm) is laminated,
It passed through a zone of impregnated rolls and a movable plate, and was finally wound up onto a paper tube at a winding section with the release sheet facing outside. Roll the sheet around 10m each into a paper tube,
This was wrapped in kraft paper laminated with aluminum foil on the inside, and both ends were tightened with release rubber to prevent the styrene monomer in the material from scattering. This product was stored for 2 days in an air bath maintained at a temperature of 40°C to age and thicken. After taking it out and cooling it to room temperature, it was made into tapes with widths of 100 mm and 150 mm using a commercially available slitter (a machine whose roll surface has been treated with release properties).
It was wrapped around a paper tube core of the same width to a length of about 10 meters, and then stored and sealed in a cylindrical tin can.

The sheet-like composite material product obtained as this tape had a thickness of about 0.8 mm, was flexible, and had considerable adhesiveness. Almost no residual air bubbles were observed in the material.

Comparison row 1 Among the operating conditions of the composite laminate manufacturing machine of Example 1, all conditions were as in Example 1 except that the vibrator was stopped.
A manufacturing test was carried out using the same method.

After thickening the produced sheet-like material, before slitting it, a square cut of approximately 100 mm was cut out while still stacked on a release sheet, and the state of the remaining air bubbles was observed.
Considerable air bubbles were observed.

Application example 1 Five sheets of 150 x 150 mm ² were cut from the sheet-like product with a width of 150 mm obtained in Example 1, the release sheet was removed, the sheets were overlapped, and the sheets were heated at a temperature using a 50-ton compression molding machine. Processed at 160℃ for 2 minutes,
A plate of 200 mm square and approximately 2 mm thick was molded. No residual bubbles or whitening were observed on this board.

Application example 2 After the outer surface of a steel pipe with a length of 1000 mm and an outer diameter of 70 mm was scuffed and cleaned, the sheet material with a width of 100 mm obtained in Example 1 was placed on top of the pipe while peeling off the release sheet. The ends were overlapped by 20 mm and wrapped diagonally, and a release sheet was placed over this and pressed down with the palm of the hand to bring the pipe surface and the sheet-like material into close contact, so that no air remained between them. This product was placed in an air constant temperature bath maintained at a temperature of 160 to 165°C for 3 minutes, and then taken out.

The FRP layer wrapped around the outside of the pipe was hard with a Barcol hardness of 58 (same for 934-1 types and below), and no residual bubbles or whitening were observed.

Example 2 Vinyl ester resin (Epivis type epoxy acrylate resin: Lipoxy R802, manufactured by Showa Kobunshi)
Mix 7.2 parts of phthalic anhydride to 100 parts,
The reaction was carried out at ~110°C for 90 minutes. This modified vinyl ester resin (liquid mixed with about 45% styrene) 100
In part, photosensitizer, 2-hydroxy-2-methyl-
1-phenylpropanone (Darokyua 11173,
1 part of Magnesium oxide (Magmik, manufactured by Kyowa Kagaku Kogyo) was added as a thickener, and the mixture was stirred and mixed under reduced pressure using an intensive mixer. The viscosity of this liquid resin mixture was 15 poise.

A sheet-like composite material was produced using the same machine and method as in Example 1, and after 2 days of thickening, a tape-like product with a width of 100 mm was obtained using a slitter. The product was a flexible sheet approximately 0.7 mm thick and highly adhesive. Almost no air bubbles remained in this product.

Application example 3 The top surface of a 3 mm thick flat iron plate (approximately 100 x 100 mm ² ) with some red rust visible was cleaned by scrubbing.
On top of this, 2-hydroxy-2-methyl-1 was added to the vinyl ester resin (Lipoxy R802) of Example 2.
- Brush a solution containing 1% phenylpropanone as a primer, and then apply Example 2 on top of that as a primer.
The sheet-like material manufactured by was cut into 100 mm square pieces, pasted together, and crimped.

Commercially available light irradiation equipment (sunlight, SSL-250A,
A 100 V (manufactured by Stanley Electric) was turned on and irradiated vertically from 10 cm above the surface of the sheet material. Curing progresses with the irradiation time, and after 10 minutes, the FRP layer has a Barcol hardness of 51 and an adhesion strength of 50 kg/kg in a peel test using an adhesion tester (Elcometer).
Cohesive failure occurred in ^cm2 . Almost no air bubbles were observed in the FRP layer.

Comparative Example 2 A sheet-shaped vinyl ester resin composite material was manufactured using the same raw materials as in Example 2 and using the same manufacturing equipment and conditions as in Comparative Example 1. After thickening this material, slit it to a width of 100mm, and then
A square sheet was cut out and cured by irradiation with light in the same manner as in Application Example 3. After 10 minutes, scattered white areas were observed in the cured FRP product.

Application Example 4 The vinyl ester resin composite tape (width 100 mm) obtained in Example 4 was wrapped around an iron pipe in the same manner as Application Example 2. This object was held horizontally on a pedestal at a height of about 500 mm and exposed to sunlight (location: Isesaki City, Gunma Prefecture, date and time: May, 2:00 p.m.). An aluminum plate was placed under the pedestal so that sunlight reflected and hit the back side of the pipe. After 20 minutes, the FRP layer on the back side was almost cured. As a result of visual inspection of the entire surface of the FRP layer,
No white spots or residual bubbles were found.

〔Effect of the invention〕

The sheet-shaped resin composite material for molding according to the method of the present invention is produced by wrapping or pasting a structure made of metal, concrete, or plastic around the outside or inside of the molded product, and then hardening it to form an FRP surface layer. Alternatively, since the FRP lining layer can be easily formed, it can provide a new and useful method in the fields of composite pipe manufacturing and reinforcement/corrosion-proof FRP lining construction for buildings and structures. We also provide useful processes for easily and high-quality manufacturing of various FRP molded products using various medium-high pressure molding methods.

In particular, air bubbles can be kept to a minimum even during no-pressure or low-pressure molding, including wrapping and pasting, thereby providing molded products with excellent mechanical and electrical strength, as well as water resistance, corrosion resistance, and weather resistance. There is practical value of the molding material of the present invention.

[Brief explanation of the drawing]

The figure is a schematic diagram of a sheet-shaped resin composite manufacturing machine of the present invention. 1... Chopped strand mat, 2... Peeling sheet, 3... Knife coater, 4... Vibrator, 5... Movable plate, 6... Impregnated (stripe) roll,
7... Winding roll, 8... Liquid resin.

Claims (1)

[Claims] 1. A fiber base material and a liquid resin are laminated on a release sheet that moves at a constant speed, and this laminate is impregnated by pressing with multiple impregnation rolls to form a sheet-shaped resin composite for molding. In the method of manufacturing the material, a rectangular smooth-surfaced plate with a width within the width of the release sheet and a length within the length from the tip roll to the end roll is placed in contact with the underside of the release sheet. Manufactures a sheet-like resin composite material for molding characterized by providing one sheet or a plurality of sheets side by side and applying vertical vibration to this sheet to give pulsations to the pressure of the upper impregnating roll on the laminate. how to.