JP2001071388A - Method and apparatus for impregnation of resin varnish - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain good impregnation properties by dropping a resin varnish from one side of a fiber base material and making the base material impregnated with the varnish by pressing it forcibly by a roll. SOLUTION: A supply roll 2 for a fiber base material 1, an impregnation tank 5 for storing a resin varnish 6, a resin varnish dropping device 3, and a press roll 4 are provided, and a drying oven 7 for drying the base material 1 impregnated with the varnish 6 is preferably provided. In the device 3, the varnish 6 is supplied to the base material 1 at a constant speed. The amount of the resin to be incorporated is preferably 30-60 wt.% when the impregnated material is put in the oven 7. When pressure is applied by a press roll, in order to change the direction of the material, a return roll 9 is used preferably. The pressing force of the press roll 4 is preferably 0.5-15 kg/cm2. The impregnation ration of the varnish 6 is increased, and a bubble surface percentage in the production of a prepreg, etc., can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for impregnating a resin varnish.

[0002]

2. Description of the Related Art A prepreg used for a printed wiring board or the like is formed on a fiber base such as paper, glass cloth, synthetic fiber or natural fiber or a non-woven cloth, and is heated in liquid form such as phenol, epoxy, polyester or polyimide. A curable resin (hereinafter referred to as a resin varnish) is impregnated, and the amount of the resin varnish attached is adjusted with a squeeze roll or the like.
The resin varnish is dried to a semi-cured state.

[0003]

However, if air bubbles remain in the prepreg, the surface of the prepreg will not be smooth after curing and an uneven surface will be formed, resulting in a prepreg which is inferior in heat resistance and stable in performance. There is a problem that it cannot be obtained. Therefore, in order to improve the impregnation and cleaning of the resin base material with the resin varnish, the time and distance for immersion in the resin varnish are set long, and the coating speed is set low. However, in such a method, productivity is low, curing for removing bubbles is insufficient, smoothness of the prepreg surface is difficult, and the solvent must be increased to lower the viscosity, resulting in high cost. There are problems such as becoming.

[0004] An object of the present invention is to provide a resin varnish impregnation method and a resin varnish impregnation apparatus which are excellent in impregnating resin varnish into a fiber base material.

[0005]

The resin varnish impregnating method of the present invention is characterized in that a resin varnish is dropped from one side of a fiber base material and then impregnated with a roll.

Further, the resin varnish impregnating apparatus of the present invention comprises a supply roll for supplying a fiber base material, a device for dropping the resin varnish on the fiber base material unwound from the supply roll, and a method for forcing the lowered resin varnish. A pressure roll for pressurizing and impregnating the resin, an impregnation tank for storing the resin varnish, and an impregnation roll provided in the impregnation tank.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown schematically in FIG. 1, a resin varnish impregnating apparatus includes a supply roll 2 for a fiber base material 1,
It is preferable that a drying furnace 7 for drying the fiber base material 1 impregnated with the resin varnish 6 is provided, comprising an impregnation tank 5 for storing the resin varnish 6, a resin varnish dropping device 3, and a pressure roll 4. The dropping device may be any device that can supply the resin varnish to the fiber base material at a constant speed,
A resin varnish supply port may be provided at the bottom of a tank for storing a normal resin varnish, and the opening may be controlled by a solenoid valve to control the supply speed of the resin varnish to be constant. At this time, the impregnation amount of the resin is preferably 30 to 60% by weight when entering the drying oven. The same roll as the impregnation roll can be used for the pressure roll 4. In addition, pressure is applied by a pressure roll, and it is preferable to use a return roll 9 in order to change the direction of the fiber base material at that time. The pressure of the pressure roll 4 is 0.5 to 15 kg /
It is preferably in the range of cm ² .

[0008]

EXAMPLE A supply roll 2 for a fiber base material 1 and a resin varnish 6
A drying furnace 7 for drying the fiber base material 1 impregnated with the resin varnish 6, comprising an impregnation tank 5, a resin varnish dropping device 3, and a pressure roll 4 for storing the resin varnish. A resin varnish supply port was provided at the bottom of the storage tank, and the opening was controlled by a solenoid valve to control the supply rate of the resin varnish to be constant. As the pressure roll 4, a roll having a diameter of 150 mm, which is the same as the impregnation roll 9, is used, and the interval is 1000 m
m, at a height of 1000 mm, four places. The same thing was used for the return roll 10, the interval was set to 1000 mm, the height was set to 2000 mm, and the return roll 10 was set so that the interval in the horizontal direction was equal to that of the pressure roll 4. Under the pressure roll 4, the return roll 10, and the dropping device 3, a tray 8 for resin varnish was installed so as not to stain the floor surface. As a feeding device, a winding roll (not shown) was provided on the outlet side of the drying furnace, and the winding was performed. The winding speed was 10 m / min. The resin varnish contains 100 parts by weight of a brominated bisphenol A type epoxy resin DER-518 (trade name, manufactured by Dainippon Ink and Chemicals, Inc.), 3 parts by weight of dicyandiamide as a curing agent, and 20 parts by weight of a solvent ethylene glycol monomethyl ether. To give a varnish. The varnish has a viscosity of 100 m at 30 ° C.
Pa · s. This varnish was poured into the impregnation tank, and a varnish having a viscosity diluted to 30 mPa · s was further dropped. As the fiber base material, a prepreg was prepared using a glass cloth having a thickness of 200 μm. In the prepreg produced in the example, the ratio of bubbles per unit area when viewed from above, that is, the bubble area ratio of the prepreg was 30%.
As a comparative example, a prepreg was manufactured under the same conditions as in the above example without using the dropping device 3, the pressure roll 4, and the return roll 10 of FIG. As a result, the bubble area ratio of the obtained prepreg was 48%. As is clear from this, it was confirmed that the impregnation device according to the present invention had a higher impregnation rate of the resin varnish than before.

[0009]

As described above, according to the present invention, it is possible to provide a resin varnish impregnation method and a resin varnish impregnation apparatus which are excellent in impregnating resin varnish into a fiber base material.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing an embodiment of the present invention.

[Explanation of symbols]

 1. Fiber base material 2. Supply roll 3. Dropping device 4. Pressure roll 5. Impregnation tank 6. Resin varnish 7. Drying oven 8. Saucer 9. Impregnating roll 10. Return roll

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29K 105: 08 F term (Reference) 4D075 AB03 AB12 AB32 AC12 AC72 AE24 DA04 DB20 DC21 4F205 AA39 AB03 AC05 AD16 AH36 HA06 HA08 HA33 HA37 HA43 HB02 HC04 HC05 HC16 HF01 HF29 HF46 HK02 HK25 HM03 HM06

Claims (2)

[Claims] 1. A resin varnish is dropped from one side of a fiber base material,
Thereafter, the resin varnish impregnation method is forcibly impregnated with a roll. 2. A supply roll for supplying a fiber base material, an apparatus for dropping a resin varnish on the fiber base material unwound from the supply roll, and a pressure roll for forcibly impregnating and impregnating the lowered resin varnish. A resin varnish impregnation tank for storing a resin varnish, and an impregnation roll provided in the impregnation tank.