JPH05301240A - Production of fiber fabric composite resin film - Google Patents

Abstract

PURPOSE:To mold a thin resin film excellent in brittleness by placing a fiber fabric on a crystalline thermoplastic resin film and placing a second crystalline thermoplastic resin film on the fabric and pressing the whole under heating in an autoclave to quench the same at a cooling speed of 10 deg.C/sec or higher. CONSTITUTION:Glass cloth 12 with a thickness of 50mum is placed on a first resin film 11a composed of a polyphenylene sulfide resin with a thickness of 25mum and m.p. of 281 deg.C and a second resin film 11b with a thickness of 25mum is placed on the glass cloth 12. The whole is introduced into an autoclave to be heated and pressed at 300 deg.C or higher under pressure of 5kg/cm<2> to form an integrated fiber fabric composite polyphenylene sulfide resin film 13 with a thickness of 75mum. Since the whole is uniformly heated and pressed under vacuum within the autoclave, the resin is sufficiently infiltrated in the fabric. The film taken out of the autoclave is suddenly cooled at a cooling speed of 10 deg.C/sec or higher and the crystal growth of the resin is suppressed and brittleness is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite resin film using a crystalline thermoplastic resin, and more particularly to a method for producing a crystalline thermoplastic resin film in which fiber woven fabric is composited.

[0002]

2. Description of the Related Art Crystalline thermoplastic resins generally have higher heat resistance than amorphous thermoplastic resins, and are promising resin materials for electronic circuit boards and the like that require soldering. In particular, in the case of a film, a multilayer substrate can be easily realized by laminating films after circuit wiring is provided. However, the crystalline thermoplastic resin film has a large shrinkage due to heating,
Since the resin viscosity at the time of melting is low, it is difficult to perform accurate molding by heat processing such as hot pressing. Further, for the purpose of reducing the resin flow at the time of heat shrinkage or melting, a method of mixing a fiber woven fabric such as glass cloth in a resin film other than the crystalline thermoplastic resin is generally performed. However, in the case of a crystalline thermoplastic resin, there is no method for thinly and uniformly dispersing the resin in the fiber woven fabric, and a crystalline thermoplastic resin film containing a fiber woven fabric such as glass cloth has not been produced so far. .. Further, the crystalline thermoplastic resin has a drawback that it becomes brittle once it is molded by heat.

Therefore, most of the processing of the crystalline thermoplastic resin is carried out by injection molding. In injection molding, few are made of resin alone, and many are made of filler such as glass. Although it is possible to produce a film-like product by injection molding, the one with a filler had the drawback that the dimensional stability during heat processing was poor and the strength was inferior to that with a fiber woven fabric. .. Therefore, recently, a method of forming a woven fabric by mixing a fiber woven fabric such as glass fiber and a fiber of a crystalline thermoplastic resin has been performed. However, this method could not produce a thin film.

[0004]

The production of the fiber woven composite film by using the crystalline thermoplastic resin has the above problems. Therefore, the present invention is to provide a method for producing a fiber woven composite crystalline thermoplastic resin film which is thin, uniform and excellent in brittleness.

[0005]

In order to achieve the above object, in the present invention, a crystalline thermoplastic resin material and an object to be processed laminated with a fiber woven fabric are treated at a temperature equal to or higher than the melting point of the crystalline thermoplastic resin material. And a cooling step of cooling the workpiece at a rate of 10 ° C. or more per second after completion of the heating / pressurizing step.

Further, in the present invention, after the cooling step is completed,
Again, a reheating step of holding the workpiece at a temperature above the glass transition point and below the melting point of the crystalline thermoplastic resin material, and then recooling the workpiece at a rate of 10 ° C. or more per second. And a manufacturing step including a step of performing.

[0007]

The crystal growth of the crystalline thermoplastic resin is determined by the holding temperature above the glass transition point and below the melting point, the time, and the subsequent cooling rate. When the material is held at a temperature and for a time at which the desired degree of crystal growth is obtained and then rapidly cooled, the crystal remains in the state just before the rapid cooling and solidifies. Utilizing this property, it has become possible to manufacture a fiber woven composite crystalline thermoplastic resin film having desired properties.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

FIG. 1A is a cross-sectional view showing a laminated structure, in which a first resin film 11a made of polyphenylene sulfide resin having a thickness of 25 .mu.m and a melting point of 281.degree.
A glass cloth 12 having a thickness of 50 μm is placed, and a second resin film 11b made of polyphenylene sulfide resin having a thickness of 25 μm is further placed thereon. The glass cloth 12 is formed by weaving warp threads 12a and weft threads 12b made of glass fibers. This is put in an autoclave (atmosphere press), and the pressure is 5 kg for 1 hour at 300 ° C., which is higher than the melting point of the polyphenylene sulfide resin.
/ Cm ² Heat and pressurize under the conditions. As a result, FIG. 1 (b)
The fiber woven fabric composite polyphenylene sulfide resin film 13 having a thickness of 75 μm integrated as described above can be manufactured. Here, the autoclave is used for temperature,
This is because the pressure can be uniformly applied to the work piece, and in particular, since the work piece is placed in a vacuum as described later, the bubbles remaining in the work piece can be reduced.

In the state of FIG. 1 (a) before heating and pressurization, the first resin film 11a and the second resin film 11 are
Although b is in a state in which the crystal structure is retained, the crystallinity is released and becomes a molten state as heating and pressurization progress. As a result, the first and second resin films 11a, 1 which are in a molten state
1b penetrates into the fibers of the glass cloth 12 as shown in FIG. 1 (b). After that, through the cooling described in detail later,
The first and second resin films 11a and 11b are recrystallized in the glass cloth to form the fiber woven composite polyphenylene sulfide resin film 13.

The structure of the autoclave will be described with reference to FIGS. 2 and 3. FIG. 2 is an overall configuration diagram of the autoclave. Although not shown, in the pressurizing chamber 21 into which a high-pressure atmosphere is sent from an external high-pressure supply unit, there is a heat press unit 25 surrounded by a heat insulating material, and a heater 22 and a blower 23 provided therein A heating atmosphere is created.
Further, the processing portion 24 is arranged below the heater 22,
A heat shield plate 26 is provided between the heater 22 and the processing portion 24. The heat of the heater 22 is supplied by the blower 23 to the arrow 27.
As described above, the heat is transmitted from the side of the heat shield plate 26 to the processing portion 24. By providing the heat shield plate 26, heat is uniformly applied to the processed portion 24.

FIG. 3 is an enlarged view of the machined portion 24, which is the workpiece 2 placed on the metal plate 28.
9 is covered with a cover sheet 27, and a packing 30 is provided between the cover sheet 27 and the metal plate 28. A vacuum suction port 31 is provided at one end of the metal plate 28. Auto-crate with such a configuration
The process of heating and pressurizing using a slab will be described below.

The workpiece 29 is heated and pressed through the cover sheet 27 by vacuum suction. Since the work piece 29 is uniformly heated and pressed in a vacuum state, the resin sufficiently penetrates into the woven fabric, and after cooling, a homogeneous laminated film can be obtained.

The polyphenylene sulfide resin at 300 ° C. immediately after heating and pressurization is in a state in which crystal growth has hardly progressed. However, when the temperature is rapidly lowered at a temperature lowering rate of 10 ° C. or more per second, the polyphenylene sulfide resin becomes It is possible to obtain a film in which crystal growth is suppressed and which is not brittle as compared with the composite resin film which is gradually cooled. Next, the relationship between the cooling rate and brittleness will be described with reference to FIG.

FIG. 4 shows the brittleness of polyphenylene sulfide.
Replace it with the tensile strength of the resin and change the relationship with the cooling rate after heating.
It is obtained by experiment and illustrated. Ie polyphe
Thermoplastic conductive resin on the surface of the nylene sulfide resin film
The grease paste is printed on a 2 mm square. Heat this at 300 ° C
The plate was pressed, and then the temperature decrease rate was changed. Nothing after this
Electrolytic copper plating is performed and selected only on the printed pattern
Copper was deposited. Tin-plated annealed copper wire on this pattern
Strength when soldered vertically and pulled vertically
The degree was measured. Breakage may occur in annealed copper wires and soldered parts.
However, the polyphenylene sulfide resin was destroyed
Fig. 4 shows only the data when
It The tensile strength of this method is 0.7k from a practical point of view.
g / mm² The above is required, and to achieve this, the cooling rate
It can be seen that the temperature should be 10 ° C. or more per second.

However, the rapid cooling immediately after the heating and pressurization (hot pressing) is performed as in the autoclave shown in FIGS.
It may be difficult due to the structure of the device. That is, in the case of an autoclave, it is difficult to take out a workpiece for the purpose of cooling immediately after hot pressing, because it requires a procedure such as returning to normal pressure. In that case, after cooling, the work piece taken out from the hot press machine is put in an oven or the like, and again heated to a temperature not lower than the glass transition point of the resin and not higher than the melting point, and then rapidly cooled to obtain desired characteristics. Obtainable. Here, the temperature above the glass transition point and below the melting point is
This is because the shape of the molded product does not change and the crystal is retained in a region where the change is remarkable. The reason why this reheating and rapid cooling is effective will be described below with reference to an example.

The fiber woven fabric composite polyphenylene sulfide resin film, which was hot-pressed and gradually cooled in the same constitution as that of the embodiment described with reference to FIGS. 1, 2 and 3 above, was held at 270 ° C. for 5 minutes, and then the temperature decreasing rate was changed. The samples were prepared by changing the temperature reduction rate. For each sample, the dimensional change rate before and after the treatment and the tensile strength after the treatment (same as the condition of the tensile strength) were measured, and the correlation is shown in FIG. 270
When the temperature is raised to 0 ° C., the degree of crystal growth decreases, but when it is rapidly cooled thereafter, it solidifies in a state where the degree of crystal growth is low, and the tensile strength increases. However, since the crystal growth degree is lower than that before the treatment, the dimensional change rate becomes large. In the case of slow cooling, the degree of crystal growth becomes high, so that it becomes brittle, but the dimensional change rate becomes small. That is, by controlling the rate of temperature decrease after reheating, it is possible to produce a fiber woven fabric composite crystalline thermoplastic resin film having desired properties while balancing the tensile strength and the dimensional change rate.

Although the method using the autoclave has been described in the above embodiment, the present invention is not limited to this, and a hot plate press and a laminator having high precision may be used. Needless to say.

Further, in the above embodiment, the fiber woven fabric is sandwiched between the first resin film and the second resin film. However, when smoothness of the film surface and warpage are not so required, one of the resins is used. The film may be omitted. In such a case, a powdery or granular crystalline thermoplastic resin can be used instead of the resin film.

As the fiber woven fabric, carbon fiber woven fabric, polyamide resin woven fabric, alumina fiber woven fabric or the like can be used instead of glass cloth. Instead of the fiber woven fabric, it is possible to use a fabric in which the fiber directions are not constant, such as paper, but the dimensional stability is not so high. As the resin, polyetheretherketone, liquid crystal polymer or the like can be used instead of polyphenylene sulfide.

[0021]

As described above, according to the present invention,
It is possible to mold a crystalline thermoplastic resin film that is a composite of fiber woven fabrics, and quench it from the temperature above the melting point of the thermoplastic resin, or once complete the fiber woven fabric composite crystalline thermoplastic resin film, re-glass the resin. By raising the temperature above the transition point and below the melting point and then quenching it, it becomes possible to produce a fiber woven composite crystalline thermoplastic resin film having excellent brittleness. Further, by controlling the temperature lowering rate, it is possible to produce a fiber woven fabric composite crystalline thermoplastic resin film in which the tensile strength and the dimensional change rate are well balanced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of a fiber woven composite crystalline thermoplastic resin film in an example of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of an autoclave in an example of the present invention.

FIG. 3 is an enlarged view of a main part of FIG.

FIG. 4 is a diagram showing the relationship between the temperature decrease rate and the tensile strength in the example of the present invention.

FIG. 5 is a diagram showing the relationship between the dimensional change rate and the tensile strength in the example of the present invention.

[Explanation of symbols]

 11a, 11b ... 1st, 2nd resin film 12 ... Glass cloth 12a, 12b ... Warp and weft 13 ... Composite resin film

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B29K 105: 08

Claims (10)

[Claims] 1. A heating and pressurizing step of heating and pressurizing a work to which a crystalline thermoplastic resin material and a fiber woven fabric are laminated at a temperature equal to or higher than the melting point of the crystalline thermoplastic resin material, and the heating and pressurizing step. And a cooling step of cooling the work piece at a rate of 10 ° C. or more per second after the completion of the method. 2. The work piece is formed by interposing a fiber woven fabric between a first crystalline thermoplastic resin material and a second crystalline thermoplastic resin material. A method for producing the fiber woven composite resin film described. 3. The method for producing a fiber woven composite resin film according to claim 2, wherein each of the first and second crystalline thermoplastic resin materials is a film member. 4. The first crystalline thermoplastic resin material is a film-shaped member, and the second crystalline thermoplastic resin material is a powder-shaped member or a granular member. Of the method for producing a fiber woven composite resin film of. 5. After the cooling step, a reheating step of raising the temperature of the workpiece to a temperature not lower than the glass transition point and not higher than the melting point of the crystalline thermoplastic resin material, and thereafter 10 ° C. per second. 5. The method for producing a fiber woven composite resin film according to claim 1, further comprising the step of recooling the workpiece at the above speed. 6. The method for producing a fiber woven composite resin film according to claim 1, wherein the crystalline thermoplastic resin material is a polyphenylene sulfide resin, and the fiber woven fabric is glass cloth. 7. A step of placing a work piece in which a fiber woven fabric is inserted between a first and a second crystalline thermoplastic resin film on a support base, and the work piece is hermetically sealed with a heat-resistant sheet. A step of covering the inside of the heat resistant sheet with a vacuum, a step of heating and pressing the work piece through the heat resistant sheet, and a step of cooling the work piece after the heating and pressing step. A method for producing a fiber woven composite resin film, comprising: 8. The method for producing a fiber woven composite resin film according to claim 7, wherein the cooling step is a step of lowering the temperature of the workpiece at a rate of 10 ° C. or more per second. 9. A reheating step for holding the workpiece at a temperature above the glass transition point and below the melting point of the first and second crystalline thermoplastic resin films after the cooling step is finished. 8. The method for producing a fiber woven composite resin film according to claim 7, further comprising the step of: recooling the workpiece at a rate of 10 ° C. or more per second. 10. The first and second crystalline thermoplastic resin films are polyphenylene sulfide resins,
The method for producing a fiber woven composite resin film according to claim 7, wherein the fiber woven fabric is glass cloth.