JP3351975B2 - Substrate impregnation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates are those which relate to impregnation how of impregnating a liquid resin composition from one surface of the substrate.

[0002]

2. Description of the Related Art A prepreg used for manufacturing a laminated board can be prepared by impregnating a substrate with a liquid resin composition, followed by drying and / or curing. The substrate is formed as a layer having fine continuous (or open) openings (voids), and a long continuous substrate is generally used as such a substrate. Then, the substrate is impregnated with the liquid resin composition while being continuously fed, and further passed through the heating furnace while continuously feeding the substrate impregnated with the resin composition.
Prepregs can be manufactured in a series of consecutive steps.

[0003] As a method of impregnating the base material with the liquid resin composition, there are a dipping method in which the base material is continuously immersed in a liquid resin composition in an impregnation tank while the base material is continuously fed. There is a shower system in which the resin composition is applied by a shower, but the dip system has a problem in that air is trapped inside the base material and remains, and this becomes bubbles and the unimpregnated portion tends to remain. However, there is a problem that high-speed impregnation is difficult.

Accordingly, a kiss coat system as disclosed in Japanese Patent Application Laid-Open No. 60-165213 has been provided. In the kiss coat method, as shown in FIG.
A kiss roll 11 is provided in an impregnation tank 10 for supplying
The liquid resin composition 2 is kiss- coated on one surface of the base material 1 by the kiss roll 11 by sending the liquid resin composition in contact with the peripheral surface of the kiss roll 11. In the kiss coat method, the resin composition 2 penetrates the base material 1 from one side, so that it is difficult for air bubbles to be trapped inside the base material 1.

[0005]

However, even in such a kiss coat system using the kiss roll 11, the substrate 1
Has a problem that the impregnating property is insufficient due to the contact with the kiss roll 11 at a predetermined pressure (kiss pressure), and an unimpregnated portion remains. That is, for example, when a glass cloth made of glass yarn 12 is used as the base material 1, when one surface (lower surface) of the base material 1 comes into contact with the kiss roll 11 with a kiss pressure, a liquid resin composition as shown by an arrow in FIG. The object 2 passes between the yarns 12 and wraps around the opposite surface of the continuous base material 1 due to the kiss pressure, so that the yarn 12 is sealed with the resin composition 2 so that air is trapped in the yarn 12, The resin composition 2 cannot penetrate into the inside of the yarn 12 and an unimpregnated portion remains.

The long continuous base material 1 is always fed in the longitudinal direction, and the surface of the base material 1 is affected by wind caused by the transport of the base material 1 and wind generated by other causes. . When wind acts on the surface of the base material 1 as shown by an arrow in FIG. 7B, the solvent is easily evaporated from the surface of the resin composition 2 impregnated in the base material 1 and the surface of the resin composition 2 , The capillary penetration into the inside of the yarn 12 is suppressed, and the unimpregnated portion tends to remain. In particular, in the resin composition 2 in which a styrene monomer is blended as a crosslinking agent, when wind acts on the surface of the substrate 1, the styrene monomer is easily evaporated, and the viscosity of the resin composition 2 increases, so that such a problem occurs more. It is easy to do.

[0007] The present invention has been made in view of the above points, and a method for impregnating a base material capable of impregnating a base material with a highly impregnable liquid resin composition and capable of high-speed impregnation is provided. It is intended to provide.

[0008]

According to the method of impregnating a base material according to the present invention, when impregnating an opening of a base material 1 having an opening with a liquid resin composition, the base material 1 is impregnated with a liquid resin composition. It is characterized in that one surface of the substrate 1 is brought into contact with the liquid resin composition 2 while being kept in a state of being positioned above the object 2.

The invention according to claim 2 is characterized in that the base material 1 is a long continuous base material that is continuously supplied. The invention according to claim 3 is characterized in that the substrate 1 is brought into contact with the liquid resin composition 2 in a state where the substrate 1 is inclined at a predetermined angle. Further, according to the invention of claim 4, the liquid resin composition 2 flows down on the upper surface of the plate pan 3 inclined at a predetermined angle, and the substrate 1 is fed in parallel with the upper surface of the plate pan 3, One of the surfaces of the substrate 1 is brought into contact with the liquid resin composition 2 flowing down the upper surface of the pan 3.

According to a fifth aspect of the present invention, a supply tank 4 for supplying the liquid resin composition 2 is provided above the plate pan 3 and the liquid resin composition 2 overflowing the supply tank 4 is supplied to the plate pan 3. Characterized in that it flows down to the upper surface. The invention according to claim 6 is characterized in that, at a place where the base material 1 is brought into contact with the liquid resin composition 2, the side opposite to the contact surface of the base material 1 with the resin composition 2 is surrounded by a windshield 5. It is.

[0011]

[0012]

Embodiments of the present invention will be described below. FIG. 1 shows an example of an embodiment of the present invention, in which a plate pan 3 is arranged at an angle of θ = 0 to 90 ° like a slide, and an upper end portion of the plate pan 3 is provided. The supply tank 4 is provided integrally with a receiving tank 15 at the lower end of the plate pan 3. The inclination angle of the plate pan 3 is preferably in the range of 10 to 70 °, more preferably 25 to 60 °, and most preferably 30 to 45 °. Liquid resin composition 2 is supplied to supply tank 4 from inlet 16 at a predetermined constant flow rate. Thus, the supply tank 4
The liquid resin composition 2 supplied to the plate pan overflows from the supply tank 4, and the overflowed liquid resin composition 2 flows into the inclined upper surface of the plate pan 3 from its upper end and flows down, and flows into the receiving tank 15 at its lower end. It comes in from. The liquid resin composition 2 flowing into the receiving tank 15 flows out of the outlet 17, but is circulated to the supply tank 4.

The resin composition 2 can be used without any particular limitation as long as it is a liquid used in the production of a laminated board.
For example, epoxy resin, phenol resin, polyimide resin, melamine resin, and varnish of radical polymerization type thermosetting resin can be used. The radical polymerization type thermosetting resin is a resin in which the curable resin contains a radically polymerizable double unsaturated group and is cured by a radical polymerization reaction of the unsaturated group, and is an unsaturated polyester, epoxy acrylate resin, diallyl phthalate resin. , Vinyl ester resin, polyester acrylate resin, urethane acrylate resin, spirane resin and the like. In the present invention, a crosslinking monomer, for example, a styrene monomer or a polymerization initiator may be used as a crosslinking agent in the resin composition in addition to these resins. In addition, inorganic fillers (eg, silica, calcium carbonate) and solvents for adjusting the viscosity of the resin composition or liquefying (eg, ketones such as acetone, alcohols such as methanol,
Amides such as N, N-dimethylformamide).

The resin composition particularly suitable for use in the present invention includes (A) an epoxy resin, (b) a conjugated diene rubber polymer containing an amino group and / or a carboxyl group (for example, a carboxyl group). (C) a rubber-modified vinyl ester resin obtained by reacting acrylic acid and / or methacrylic acid, (B) a radically polymerizable monomer (eg, styrene, acrylic acid, methacrylic acid, etc.), And (C) a radical polymerization initiator (eg, methyl ethyl ketone peroxide, cumene hydroperoxide). This resin composition is thermosetting, and its details are described in JP-A-3-73339 (Japanese Patent Publication No. 5-29548, U.S. Pat. No. 4,866).
134, corresponding to British Patent No. 2158830 and German Patent Application No. P3512791), the disclosures of which are incorporated herein by reference.

Among the resin compositions of this type, the resin composition most preferably used in the method of the present invention is the component (B)
Styrene and a radical polymerizable monomer having an OH group (for example, acrylic acid, methacrylic acid, tetramethol methane triacrylate, tetramethol methane trimethacrylate, etc.), and the content of the radical polymerizable monomer having an OH group Is 4 to 8% by weight of the whole resin composition.
This resin composition can be preferably used for producing a laminate, for example, a copper-clad laminate. This most preferred resin composition is disclosed in Japanese Patent Application No. 64322/1996, the disclosure of which is incorporated herein by reference.

On the other hand, the base material 1 used in the present invention is a fine continuous (or open) material into which the liquid resin composition 2 penetrates.
Any type of fiber (yarn constituting a substrate) may be used as long as it is a layered material having an opening (void) formed therein, such as glass fiber or ceramic fiber. Cloths, papers, mats and the like using inorganic fibers such as polyester fibers, organic fibers such as polyester fibers, polyamide fibers, polyacryl fibers, and polyimide fibers, and natural fibers such as cellulose fibers and cotton can be used. The yarn constituting the base material may be a monofilament yarn or a multifilament yarn. In particular, when a substrate composed of a multifilament yarn is applied to the method of the present invention, the resin composition 2 is formed not only in the relatively large voids between the yarns but also in the relatively fine voids between the filaments constituting the yarn. Can be impregnated.

The substrate 1 is generally formed on a continuous substrate in the form of a long strip, and is always fed at a predetermined constant speed. Then, the base material 1 above the plate pan 3
Is suspended between a pair of feed rolls 18 and 18 so as to be parallel to the upper surface of the plate pan 3, and the gap between the base material 1 and the plate pan 3 flows down the upper surface of the plate pan 3. The liquid thickness of the liquid resin composition 2 is set to be substantially equal to the liquid thickness. The distance between the base material 1 and the plate pan 3 is generally set to 0.5 to 30 mm, and preferably 1 to 5 mm, more preferably 1.5 to 3 mm in this range. is there.

In this case, the liquid resin composition 2 is caused to overflow from the supply tank 4 and flow down the upper surface of the plate pan 3 while flowing the base material 1 as shown by an arrow in FIG.
Is sent, the lower surface of the base material 1 contacts the liquid surface of the liquid resin composition 2 on the plate pan 3, and the liquid resin composition 2 permeates the base material 1 from the lower surface. The surface (upper surface) of the substrate 1 on the side opposite to the side in contact with the resin composition 2 is only in contact with the atmospheric gas (usually air), and is substantially free of contact with other objects. It is in a state. Therefore, when the liquid resin composition 2 permeates from the lower surface of the base material 1 as described above, the air in the base material 1 is expelled from the free upper surface when the liquid resin composition 2 permeates, and the base material 1 The liquid resin composition 2 can be impregnated in the base material 1 without air remaining in the base material 1.

Here, the lower surface of the base material 1 is only in contact with the liquid surface of the liquid resin composition 2, and since no pressing force is applied, the liquid resin composition 2 is capillarized. It penetrates from the lower surface of the substrate 1 to the upper surface, and FIG.
In the case where the base material 1 is made of glass cloth as in the case of (1), the yarn 12 is not sealed with the liquid resin composition 2, and it is possible to prevent air from being trapped in the yarn 12. The liquid resin composition 2 can be impregnated into the base 1 by impregnating the liquid resin composition 2 into the yarn 12 without leaving an unimpregnated portion. Moreover, the kiss roll 11 as shown in FIG.
When the kiss roll 11 is used, the kiss roll 11 can only apply the liquid resin composition 2 to the substrate 1 as a line, but in the present invention, the liquid The base material 1 can be brought into contact with and penetrate the resin composition 2, and the continuous base material 1 can be impregnated with a sufficient amount of the liquid resin composition 2 even if the feeding speed of the base material 1 is increased. And high-speed impregnation becomes possible. The time for bringing the substrate 1 into contact with the liquid resin composition 2 is as follows:
It is common to reserve at least 5 seconds, preferably at least 10 seconds, more preferably at least 15 seconds.

FIG. 2 shows another example of the embodiment of the present invention. In the place where the base material 1 is brought into contact with the liquid resin composition 2, that is, the place on the plate pan 3, The side opposite to the contact surface with the resin composition 2, that is, the upper side of the substrate 1 is surrounded by a windshield 5. When the base material 1 is surrounded by the windshield 5 in this way, it is possible to prevent wind from acting on the surface of the base material 1, and the solvent or styrene monomer of the liquid resin composition 2 that has permeated into the upper surface side of the base material 1 is The evaporation can be suppressed , and as shown in FIG. 4, the viscosity of the liquid resin composition 2 on the upper surface of the base material 1 is prevented from increasing, and the capillary action reaches the inside of the yarn 12. This makes it easy to penetrate the liquid resin composition 2.

FIG. 3 shows still another example of the embodiment of the present invention. In addition to enclosing the upper side of the base material 1 with a windshield 5 at a position above the plate pan 3, a liquid resin composition in the plate pan 3 The base material 1 immediately after the impregnation of the object 2 is passed through the windshield 6, and is sent while being surrounded by the windshield 6. By sending the substrate 1 while enclosing it with the windshield 6, it is possible to prevent wind from acting on the upper and lower surfaces of the substrate 1. This prevents the viscosity of the liquid resin composition 2 on both surfaces from increasing, and facilitates the penetration of the liquid resin composition 2 into the yarn 12 by capillary action.

After the substrate 1 is impregnated with the liquid resin composition 2 as described above, the substrate 1 impregnated with the liquid resin composition 2 is further continuously fed and passed through a heating furnace. The prepreg can be manufactured by heating and drying. Then, one or a plurality of the prepregs are stacked and hot-pressed to produce a laminate. In addition, a metal-clad laminate can be manufactured by laminating a metal foil such as a copper foil on one or both surfaces of one or a plurality of prepregs, and hot-pressing the metal foil. A printed wiring board can be manufactured by forming a circuit by performing printed wiring on a foil.

[0023]

Next, the present invention will be further described with reference to examples. Example 1 A substrate 1 was impregnated with a liquid resin composition 2 in the apparatus shown in FIG. Here, as the resin composition 2, a radical polymerization type thermosetting resin prepared by mixing the following components and defoaming under reduced pressure at 0.1 atm for 30 minutes was used.・ Vinyl ester resin (“S510” manufactured by Showa Polymer Co., Ltd.): 100 parts by weight ・ Radical polymerization initiator (“Perbutyl O” manufactured by NOF Corporation): 1 part by weight ・ Styrene: 6 parts by weight 1 is 0.18mm thick and 1000mm wide
Using a long strip-shaped glass cloth ("7628" manufactured by Asahi Schwebel Co., Ltd .: Style 7628 type specified in ASTM standard D579) at a feed speed of 2 m / min. Furthermore, the inclination angle θ of the plate pan 3 is 30 °, and the horizontal length L of the plate pan 3 is L = 1.
m, the gap between the continuous substrate 1 and the plate pan 3 was adjusted to about 2 mm, and the supply amount of the liquid resin composition 2 was adjusted to 10 liter / min.

Example 2 A substrate 1 was impregnated with a liquid resin composition 2 using the apparatus shown in FIG. Here, what was formed with PET film as the windshield 5 was used.
The windshield 5 was arranged at a distance of 50 mm from the upper surface of the substrate 1 so that the upper surface of the substrate 1 was entirely covered at the plate pan 3. Other conditions are the same as in the first embodiment.

Example 3 A substrate 1 was impregnated with a liquid resin composition 2 using the apparatus shown in FIG. Here, what was formed with a PET film as the windshield 6 was used.
50mm away from the upper and lower surfaces of the windshield 6
Was arranged so as to cover the upper surface and the lower surface of the substrate 1 over 1 m in the longitudinal direction. Other conditions are the same as in the second embodiment.

Comparative Example 1 A substrate 1 was impregnated with a liquid resin composition 2 using a kiss roll apparatus shown in FIG. Here, in FIG. 5, the diameter of each kiss roll 11 was set to 130 mm, and the distance between the kiss rolls 11 was set to 2000 mm. The same resin composition 2 and substrate 1 as in Examples 1 to 3 were used, and the feed speed of substrate 1 was also set to the same as in Examples 1 to 3.

In Examples 1 to 3 and Comparative Example 1,
When the base material 1 was visually inspected at a position 3 m away from the final part where the liquid resin composition 2 penetrates the base material 1 toward the next process, the impregnation state as shown in Table 1 was obtained.

[0028]

[Table 1]

As shown in Table 1, in the case of Comparative Example 1, the unimpregnated portion was large and the impregnating property was poor even when 3 m had passed since the application of the liquid resin composition 2 to the base material 1,
Examples 1 to 3 had little or no unimpregnated portions, and had good impregnation. (Examples 4 to 6) Liquid resin composition 2 having the following composition:
And the substrate 1 was impregnated in the same manner as in Example 1.
The feed speed of the substrate 1 and the inclination angle of the plate pan 3 were changed as shown in Table 2. Next, the substrate 1 impregnated with the liquid resin composition 2 was heated and dried at a maximum temperature of 180 ° C. to prepare a prepreg having a dried resin amount of 51% by weight.

[Blending of resin composition] Epoxy grease (1): tetrabromobisphenol A type epoxy resin having an epoxy equivalent of 500 ("YDB-500" manufactured by Toto Kasei Co., Ltd.) ... 94 parts by weight-Epoxy resin (2): Cresol novolak type epoxy resin having an epoxy equivalent of 220 (“YDCN-220” manufactured by Toto Kasei Co., Ltd.): 13 parts by weight ・ Curing agent: dicyandiamide ... 2.8 parts by weight ・ Curing accelerator: 2 -Ethyl-4-methylimidazole 0.1 weight part Solvent: N, N-dimethylformamide 25 parts by weight (Comparative Example 2) Using the apparatus of Comparative Example 1 (kissrol),
The liquid resin composition 2 used in Examples 4 to 6 was impregnated into the substrate 1. In addition, the feed speed of the base material 1 was 3 m / min. After that, the amount of resin after drying was 5 in the same manner as in Examples 4 to 6.
A 1% by weight prepreg was prepared.

After cutting the prepregs obtained in Examples 4 to 6 and Comparative Example 1 into a size of 10 × 10 cm,
After heating by suspending in an electric furnace at 163 ° C. for 15 minutes, and then cooling, the presence or absence of a portion not impregnated with the resin was visually observed and evaluated. Table 2 shows the evaluation results.

[0032]

[Table 2]

As can be seen from the evaluation results of Example 6 in Table 2, even when the inclination angle is 90 °, it is confirmed that the impregnation property is higher than that of Comparative Example 2 using a kiss roll. In addition, as can be seen from the evaluation results of Examples 4 and 5, even when the feed rate of the base material was increased, the impregnation property was higher than that of Comparative Example 2 using kiss rolls, and it was confirmed that high-speed impregnation could be achieved.

[0034]

As described above, according to the present invention, when the liquid resin composition is impregnated into the opening portion of the base material having the opening portion, the base material is kept in a state positioned above the liquid resin composition. While one surface of the base material was brought into contact with the liquid resin composition, the base material had only one surface in contact with the liquid resin composition, Can be prevented from acting, and the liquid resin composition can be satisfactorily penetrated into the base material by capillary action. The composition can be impregnated.

Further according to claim 2 invention, since to use a continuous long base material which is continuously fed as a substrate,
The liquid resin composition can be impregnated while the base material is continuously fed, so that the productivity can be improved. According to the third aspect of the present invention, the base material is brought into contact with the liquid resin composition in a state where the base material is inclined at a predetermined angle, so that only one surface of the base material is brought into contact with the liquid resin composition. Is easier.

Further, according to a fourth aspect of the present invention, the liquid resin composition is caused to flow down on the upper surface of the plate pan inclined at a predetermined angle, and the substrate is fed in parallel with the upper surface of the plate pan. Because one surface of the base material was brought into contact with the liquid resin composition flowing down the upper surface of the plate pan, the base material was brought into contact with the liquid resin composition from the upper end to the lower end of the plate pan. The substrate can be impregnated with a sufficient amount of the liquid resin composition even if the feeding speed of the substrate is increased, and high-speed impregnation becomes possible.

According to a fifth aspect of the present invention, a supply tank for supplying a liquid resin composition is provided above the plate pan, and the liquid resin composition overflowing the supply tank flows down to the upper surface of the plate pan. Therefore, it becomes easy to flow the liquid resin composition with the same liquid thickness over the width direction on the upper surface of the plate pan by the overflow from the supply tank, and the liquid is uniformly applied to the base material over the width direction. It becomes easy to impregnate the resin composition of the above.

Further, in the invention according to claim 6, at the place where the substrate is brought into contact with the liquid resin composition, the side opposite to the contact surface of the substrate with the resin composition is surrounded by a windshield. The effect of wind on the surface can be reduced by windshield, preventing the viscosity of the liquid resin composition on the surface of the base material from increasing, and causing the liquid resin composition inside the base material by capillary action to prevent the viscosity. It can be satisfactorily penetrated and can further improve the impregnation.

[Brief description of the drawings]

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

FIG. 2 is a schematic sectional view showing another example of the embodiment of the present invention.

FIG. 3 is a schematic sectional view showing still another example of the embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view illustrating the function of impregnation in the present invention.

FIG. 5 is a schematic diagram of an apparatus used in a comparative example.

FIG. 6 is a schematic view of a conventional example.

7 (a) and 7 (b) are schematic cross-sectional views for explaining the effect of impregnation in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base material 2 Liquid resin composition 3 Plate pan 4 Supply tank 5 Wind shield 6 Wind shield

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Joji Sakakibara 1048 Odomo Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works, Ltd. (56) References JP-A-6-1443447 (JP, A) (58) (Int.Cl. ⁷ , DB name) B29B 11/16 B29B 15/08-15/14

Claims (6)

(57) [Claims] When impregnating an opening of a base material having an opening with a liquid resin composition, one surface of the base material is maintained while the base material is kept above the liquid resin composition. A method for impregnating a substrate, comprising contacting the substrate with a liquid resin composition. 2. The method for impregnating a substrate according to claim 1, wherein the substrate is a long continuous substrate supplied continuously. 3. The method according to claim 1, wherein the substrate is brought into contact with the liquid resin composition while being inclined at a predetermined angle.
Or the method for impregnating a substrate according to item 2. 4. A liquid resin composition flowing down on the upper surface of a plate pan inclined at a predetermined angle, and flowing down the upper surface of the plate pan while feeding the base material in parallel with the upper surface of the plate pan. The method for impregnating a substrate according to any one of claims 1 to 3, wherein one surface of the substrate is brought into contact with the resin composition of (1). 5. A supply tank for supplying a liquid resin composition is provided above the plate pan, and the liquid resin composition overflowing the supply tank flows down to the upper surface of the plate pan. 5. The method for impregnating a substrate according to item 4. 6. The method according to claim 1, wherein at a place where the base material is brought into contact with the liquid resin composition, a side opposite to a surface of the base material in contact with the resin composition is surrounded by a windshield. The method for impregnating a substrate according to the above.