JPH11277652A - Method of manufacturing honeycomb core made of fiber reinforced plastic - Google Patents

Abstract

(57) [Summary] [Problem] Firstly, high-temperature heating only needs to be performed once at the end, so that the production cost is reduced. Secondly, ketones are used as a solvent. Thirdly, the present invention proposes a method of manufacturing a honeycomb core made of fiber-reinforced plastic, which can obtain a base material having an appropriate viscosity and tack and can manufacture a corrugated sheet and a honeycomb core without any trouble. SOLUTION: A base material 2 in which a diisocyanate diluted with a ketone and a tricarboxylic anhydride B are combined with a fiber base material A is used, and is reacted with polyamide-imide acid by heating at 120 to 200 ° C and further applying pressure. Then, a hardened corrugated sheet 3 or a flat sheet is formed. Also, diisocyanate and tricarboxylic anhydride B diluted with ketones are used for adhesives and reinforcement, and are reacted with polyamide-imide acid and cured by heating. And finally, 200-300
By heating at a high temperature of ° C., each polyamide-imide acid reacts to close the ring and becomes a polyamide-imide resin and is completely cured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for manufacturing a honeycomb core made of fiber reinforced plastic. That is,
The present invention relates to a method of manufacturing a honeycomb core made of fiber reinforced plastic (FRP) in which a fiber base is combined with a polyamideimide resin.

[0002]

2. Description of the Related Art Honeycomb cores have the property of being excellent in weight ratio strength, but honeycomb cores made of fiber reinforced plastic are particularly excellent in lightness. In addition, when such a honeycomb core made of a fiber-reinforced plastic is further required to have heat formability to a secondary or tertiary curved surface at the time of commercialization, or when used as a product, a temperature of from 120 ° C. to 150 ° C. When mechanical strength in a temperature range of about ° C. is particularly required, a honeycomb core made of fiber-reinforced plastic and having a configuration in which a polyamide-imide resin is combined with a fiber base material has been conventionally used.
For example, when commercialized as an aircraft engine cover, such a thermoformability and mechanical strength are required, and thus, a polyamide imide is applied to a fiber base material having characteristics corresponding to such requirements. A honeycomb core made of fiber-reinforced plastic having a configuration in which resins are combined is used. Further, such a honeycomb core made of fiber-reinforced plastic is formed by alternately stacking and bonding cell walls composed of a corrugated plate and a flat plate in which a polyamide-imide resin is combined with a fiber base material. rigidity·
A so-called bisect type having excellent strength is frequently used.

By the way, such a bisect-type honeycomb core made of a fiber-reinforced plastic composed of a fiber base material and a polyamideimide resin,
Conventionally, it was manufactured as follows. FIG. 6 is a process block diagram for explaining a manufacturing method of this type of conventional example.
In this type of conventional manufacturing method, first, as shown in the step of FIG. 6, a base material in which a polyamide imide acid is combined with a fiber base material is prepared. That is, since the polyamidoimidic acid (which is later ring-closed to form a polyamidoimide resin as described later) is solid, it is diluted with a special solvent such as NMP (N-methyl-2-pyrrolidone) or DMF (dimethylformamide). After being liquefied, it is combined with a fiber base material such as carbon fiber by adhering, impregnating, mixing, or the like.
Heated at about ° C. As a result, an extra special solvent is removed, and a semi-cured (semi-cured) prepreg sheet-shaped base material is obtained.

Thereafter, in this kind of conventional manufacturing method,
As shown in the steps and in FIG.
By heating at a high temperature of about 00 ° C. to 300 ° C. (for example, 250 ° C.) and further applying pressure, a completely cured (completely cured) corrugated sheet or flat sheet is formed. That is, the base material obtained by combining the polyamideimide with the fiber base material is supplied to a corrugating apparatus using gears and racks, and heated and pressed at a high temperature, so that the mixed special solvent is completely removed. At the same time, the polyamide-imide acid reacts to close the ring to form a polyamide-imide resin.
It has a configuration in which a polyamide imide resin is combined with a fiber base material, and a corrugated sheet having complete curing and final shape retention is formed. Similarly, by heating the base material obtained by combining the polyamide base with the polyamide-imide acid at a high temperature, the mixed special solvent is completely removed, and the polyamide-imide acid reacts to close the ring and the polyamide base reacts. It becomes an imide resin, and thus has a configuration in which a polyamide imide resin is combined with a fiber base material, whereby a flat plate having complete curing and shape retention is formed.

[0005] Then, in this kind of conventional manufacturing method,
As shown in the step of FIG. 6, an adhesive is applied to the top surface and the bottom surface of the irregularities of the molded and completely cured corrugated sheet. This adhesive uses polyamide-imide acid as NMP or DMP.
A liquid state diluted with a special solvent such as MF, or a prepreg-like state in which the liquid is semi-cured by heating it at about 120 ° C. to 150 ° C., which is the boiling point of the special solvent, is used.
Thereafter, as shown in the step of FIG. 6, the plurality of corrugated sheets to which the adhesive has been applied and the plurality of flat plates prepared as described above are sequentially and alternately stacked in a laminated block shape. Stack.

[0006] Then, in this kind of conventional manufacturing method,
As shown in the step of FIG. 6, the corrugated sheet and the flat plate thus stacked are heated from 200 ° C. to 300 ° C. (for example, 25 ° C.).
By heating and pressing at a high temperature of about 0 ° C.), the stacked corrugated sheet and the flat plate are bonded. That is, the high-temperature heating removes the special solvent mixed in the adhesive, and the polyamide-imide acid of the adhesive reacts to close the ring,
When the polyamide-imide resin is completely cured, the corrugated plate and the flat plate are bonded to each other. In this type of conventional manufacturing method, by stacking these steps, as shown in the step of FIG. 6, the stacked and bonded corrugated plates and flat plates are used as cell walls, and are partitioned by the cell walls. It consists of a planar aggregate of a large number of cells formed in a hollow columnar shape and is bonded with a polyamideimide resin adhesive, and has a configuration in which a polyamideimide resin is combined with a fiber base material. Honeycomb cores had been manufactured.

In this type of honeycomb core made of fiber reinforced plastic, as shown in the step of FIG. 6, as a post-treatment, a polyamide imide acid is coated on the outer surface of the cell wall with NMP, DMF or the like for reinforcement. The liquid diluted with the special solvent is often attached and impregnated. Then, as shown in the step of FIG.
By heating at a high temperature of about 300 ° C. (for example, 250 ° C.), the mixed special solvent is removed, and the attached and impregnated polyamide imide acid reacts to close the ring to form a polyamide imide resin. Completely cure.
As described above, such a honeycomb core made of fiber-reinforced plastic is often reinforced by post-processing.

[0008]

The following problems have been pointed out in such a conventional example. First, in the production method of this type of conventional example, in order to react polyamideimide acid to form a polyamideimide resin by reacting to close the ring, high-temperature heating at a heating temperature of about 200 ° C. to about 300 ° C. is performed. In the process
It had to be implemented, and a problem was pointed out in terms of manufacturing cost.

That is, as shown in the above-mentioned steps of FIG. 6, when the base material is formed into a corrugated sheet or when the base material is formed into a flat plate, high-temperature heating of about 200 ° C. to 300 ° C. is performed. Was. Further, as shown in the step of FIG. 6, even when bonding with an adhesive, high-temperature heating of about 200 ° C. to 300 ° C. has been performed. Further, as shown in the step of FIG. 6, high-temperature heating of about 200 ° C. to 300 ° C. has been performed during additional attachment and impregnation in the post-treatment for reinforcement. And such high temperature heating
In each case, the method has been practiced to convert the polyamide-imide acid into a polyamide-imide resin. In this kind of conventional manufacturing method, high-temperature heating of about 200 ° C. to 300 ° C. is required to be performed over a plurality of steps and performed a plurality of times, and the heating cost, that is, the manufacturing cost is increased accordingly. Was.

Secondly, the conventional production method of this kind requires the use of a special solvent which is expensive and has a high boiling point in order to dilute the polyamide-imide acid. Was pointed out. That is, as shown in the step of FIG. 6 described above, when preparing the base material, since the polyamide-imide acid is solid, NMP
It is necessary to first dilute and liquefy with a special solvent such as (N-methyl-2-pyrrolidone) or DMF (dimethylformamide), but these special solvents are very expensive. Furthermore, these special solvents also have a relatively high boiling point of 120 ° C. to 150 ° C., so that the heating temperature for removing such special solvents and converting the base material into a semi-cured (semi-cured) prepreg is obtained. And the cost increases accordingly. Also, as shown in the above-mentioned step of FIG. 6, when the adhesive is applied, the polyamide-imide acid is also diluted with the same special solvent, and further, as shown in the above-mentioned step of FIG. For additional adhesion and impregnation, a solution prepared by diluting polyamide-imide acid with a similar special solvent is used.

As this kind of solvent, inexpensive and low-boiling ketones are generally known. However, since polyamidoimidic acid does not dissolve in ketones and is not diluted, there is a problem in these steps. A ketone solvent cannot be used in place of the special solvent. In the conventional manufacturing method of this kind, a special solvent that is extremely expensive and contributes to an increase in heating cost needs to be used in a large amount in a plurality of steps. It has been pointed out that the production cost increases.

Thirdly, it has been pointed out that the conventional production method of this type has a problem that it is not easy to form a corrugated sheet because the polyamide-imide acid is poor in viscosity and tackiness. That is, as shown in the step of FIG. 6 described above, when forming a corrugated sheet by heating and pressing with high heat in a corrugating apparatus, the supplied base material is once diluted with a special solvent such as NMP or DMF. It has a structure in which a polyamide-imide acid is combined with a fiber base material, and has extremely poor viscosity and tackiness, ie, poor tackiness, due to the properties of the polyamide-imide acid. In this case, in order to give viscosity and tack,
It is conceivable to use additives such as nitrile rubber and epoxy resin. However, since these additives are not soluble in special solvents such as NMP and DMF, it is difficult to use such additives. Therefore, it is pointed out that the supplied base material is hardly stuck to the gears and racks of the corrugating apparatus due to the poor viscosity and tackiness, and thus the corrugated sheet is often not formed smoothly. was there. As described above, in the manufacturing method of this type of conventional example, there is often a problem in the formation of the corrugated sheet, and therefore, the manufacturing itself of the honeycomb core made of fiber-reinforced plastic having such a corrugated sheet as the cell wall is uncertain. Problems were pointed out.

The present invention has been made in view of such circumstances, and has been made to solve the above-described problems of the conventional example.
First, high-temperature heating is performed in the final step by using diisocyanate and tricarboxylic anhydride, which are chemical substances of the raw materials, instead of polyamide-imide acid for the adhesive and post-treatment for reinforcement. It only needs to be carried out once, in each of the previous steps, lower temperature heating is required, secondly, ketones having a low boiling point are used as solvents, and thirdly, a base material having an appropriate viscosity and tack is used. It is an object of the present invention to propose a method of manufacturing a honeycomb core made of fiber-reinforced plastic without causing any trouble in forming a corrugated sheet.

[0014]

The technical means of the present invention for solving such a problem is as follows. First, claim 1 is as follows. That is, this claim 1
In the method for manufacturing a fiber-reinforced plastic honeycomb core, first, a diisocyanate and tricarboxylic anhydride, which are stabilized and diluted with ketones,
A semi-cured prepreg sheet-like base material is prepared by combining by adhesion, impregnation, mixing and the like. Next, the base material is supplied to a corrugating apparatus, and is heated and pressed to form a corrugated sheet in which corrugations are continuously bent. At that time, the heating temperature is set to about 120 ° C. to about 200 ° C., and by such heating, the base material and the corrugated sheet react with the diisocyanate and the tricarboxylic anhydride to form a polyamide imide acid. To cure. Further, by heating the base material, a sheet-shaped flat flat plate is formed. At that time, the heating temperature is from 120 ° C to 2
The base material and the flat plate are set to about 00 ° C., and the base material and the flat plate react with the diisocyanate and the tricarboxylic acid anhydride to be cured into polyamide imide acid. In addition, a diisocyanate and a tricarboxylic anhydride, which are stabilized and diluted with ketones, are applied to the corrugated top and bottom surfaces of the corrugated sheet formed and cured as described above, respectively, as an adhesive.

Then, the plurality of corrugated sheets and the flat plates are
They are stacked one after the other in a laminated block shape. At this time, the corrugated plates are shifted from each other by a half pitch of the wave so that the bottom portion and the top portion are opposed to each other via the flat plates. Thereafter, by heating and pressing, the corrugated plates and the flat plates stacked in this manner are respectively bonded with the adhesive. At that time, the heating temperature is 120 ° C
The temperature is set to about 200 ° C., and by such heating, the diisocyanate and the tricarboxylic anhydride react with each other, and the respective adhesives are cured as polyamide imide acid. Thus, each corrugated plate and each flat plate thus stacked and adhered to each other constitute a cell wall, which is a planar assembly of a large number of hollow columnar cells defined by the cell walls.
A honeycomb core made of fiber reinforced plastic is obtained. Then, by heating the honeycomb core at a high temperature of about 200 ° C. to 300 ° C., the cell walls and the adhesive react with each other to close the polyamide imide acid to form a polyamide imide resin. Curing,
It is characterized by.

Next, claim 2 is as follows.
That is, the method for manufacturing a honeycomb core made of fiber reinforced plastic according to the second aspect is the following in the method for manufacturing a honeycomb core made of fiber reinforced plastic according to the first aspect. That is, regarding the honeycomb core made of fiber reinforced plastic obtained by stacking and bonding,
Before the above-mentioned high temperature heating of about 200 ° C. to 300 ° C., as a post-treatment, diisocyanate and tricarboxylic anhydride stabilized and diluted with ketones are used for reinforcing the outer surface of the cell wall of the honeycomb core. Is heated after being deposited and impregnated. At this time, the heating temperature is set to about 120 ° C. to about 200 ° C., and by such heating, the diisocyanate and tricarboxylic anhydride adhering and impregnated for reinforcement react with each other to form polyamidoimidic acid. To cure. Thereafter, the honeycomb core is replaced by 20
By heating at a high temperature of about 0 ° C. to 300 ° C., the cell walls, the adhesive, and the polyamide-imide acid for reinforcement, etc., react to close the ring, and are completely cured as a polyamide-imide resin. It is characterized by the following.

Next, claim 3 is as follows. That is, the method for manufacturing a honeycomb core made of a fiber-reinforced plastic according to the third aspect of the present invention is the following in the method for manufacturing a honeycomb core made of a fiber-reinforced plastic according to the first aspect. That is, in order to improve viscosity and tack, an additive such as nitrile rubber or epoxy resin is added to the base material prepared for forming the corrugated sheet.

The manufacturing method according to the present invention is as described above, and is as follows. In this production method, first, a diisocyanate and a tricarboxylic anhydride diluted with a low-boiling ketone are inexpensively combined with a fiber base material,
A semi-cured prepreg-shaped base material is prepared. This base material is provided with viscosity and tack. When further viscosity and tack are required, additives such as nitrile rubber and epoxy resin are added. Then, the base material is heated and pressed by a corrugating apparatus to form a corrugated sheet, and is further heated to form a flat sheet. The heating temperature is from 120 ° C to 2
The temperature is set to about 00 ° C., and the diisocyanate of the base material and the tricarboxylic anhydride react with each other to form a polyamidoimide, which is cured, and thus has a certain degree of shape retention. Thereafter, a diisocyanate diluted with a ketone and a tricarboxylic anhydride are applied as an adhesive to the top surface and the bottom surface of the corrugated sheet, and then the corrugated sheet and the flat plate are alternately stacked. Then, by heating and pressing, the corrugated plate and the flat plate are bonded to each other.
The temperature is set to about 00 ° C., and the diisocyanate of the adhesive and the tricarboxylic anhydride react with each other to form a polyamide imide acid, which is cured.

Thus, a honeycomb core made of fiber-reinforced plastic using such corrugated plate and flat plate as cell walls can be obtained. In many cases, as a post-treatment, diisocyanate and tricarboxylic anhydride diluted with ketones are attached and impregnated to the cell wall for reinforcement, and then heated. The temperature is set to about 200 ° C., and the diisocyanate and the tricarboxylic anhydride react with each other to be converted into a polyamidoimide and cured. Now, this fiber-reinforced plastic honeycomb core is finally heated to a high temperature. The heating temperature is set at about 200 ° C. to 300 ° C., and each polyamide imide acid for cell walls, adhesives, reinforcement, etc. reacts to close the ring, becomes a polyamide imide resin, is completely cured, and has a reliable shape. Leading to retention. In this way, the polyamide-imide resin is combined with the fiber base material, and thus, heat moldability to a curved surface and 12
A honeycomb core made of fiber reinforced plastic and having excellent mechanical strength in a temperature range of about 0 ° C. to 150 ° C. is manufactured.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments of the invention shown in the drawings. FIG. 1, FIG. 2,
3, 4, and 5 are provided for explaining the embodiment of the present invention. FIG. 1 is a perspective view, (1) FIG. 1 shows a base material sheet, (2) FIG. 1 shows a cut base material sheet, and (3) FIG. (4) The figure shows a rack and a corrugated sheet forming process using the rack. FIG.
FIG. 1A is a perspective view of a molded corrugated sheet.
(2) FIG. 3 shows a corrugated sheet to which an adhesive is applied, and (3) FIG.
3 shows a corrugated sheet and a flat sheet to be stacked. The diagram (1) in FIG.
The front view of the obtained honeycomb core, and FIG. 2B is a perspective view of the honeycomb core further immersed in a bathtub. FIG. 4 (1)
FIG. 1 is a perspective view of a honeycomb core during heating, and FIG. 2B is a front view of a finally obtained honeycomb core. FIG.
It is a process block diagram.

In the method of manufacturing the honeycomb core 1 made of fiber reinforced plastic, first, FIG.
As shown in the steps of FIG.
Then, diisocyanate and tricarboxylic anhydride B, which are stabilized and diluted with ketones, are combined by adhesion, impregnation, mixing, etc., to prepare a semi-cured prepreg-like sheet-like base material 2.

Such a base material 2 will be described in more detail. In the production method of the present invention, first, stabilized diisocyanate and tricarboxylic anhydride B are prepared, and these chemical substances are known as raw materials for polyamide imide acid. Since it is a solid, it is diluted and liquefied with a ketone such as acetone or methyl ethyl ketone (MEK), and then combined with the fiber base material A. As the fiber base material A, carbon fiber, glass fiber, Kevlar fiber, ceramic fiber, metal fiber, and other various fibers can be considered, and these fibers are appropriately selected and used. As the weaving method of the fiber base material A, plain weaving, satin weaving, twill weaving, and other various weaving methods can be considered. And this fiber base material A
Then, a diisocyanate and a tricarboxylic anhydride B diluted with a ketone are combined by any of adhesion, impregnation, mixing, or the like, or a combination thereof, thereby forming a fiber-reinforced plastic.

Then, the boiling point of ketones as a solvent is 6
By heating at about 0 ° C. to about 80 ° C. and removing excess ketones as a solvent, a semi-cured (semi-cured) prepreg-shaped base material 2 is obtained. Base material 2
The sheet is in a semi-cured state before being cured, that is, a prepreg having flexibility is prepared. FIG. 1 (1) shows a rolled state, and FIG. 1 (2) shows a sheet-like state cut to a predetermined size. Further, the base material 2 has a sufficient viscosity and tack, that is, tackiness. However, in the case where the base material 2 is supplied to the corrugating device 4 to be corrugated as described below,
When further viscosity and tack are required, additives such as nitrile rubber and epoxy resin are added to the base material 2.
This addition is performed by dissolving such an additive in a ketone as a solvent. By adding nitrile rubber or the like to the base material 2 as described above, the viscosity and tack of the base material 2 can be easily adjusted to a necessary degree. To the gears and racks. The base material 2 is like this.

Next, in this manufacturing method, FIG.
As shown in FIG. 4, (4), FIG. 2 (1), and the steps in FIG. 5, the base material 2 is supplied to the corrugating apparatus 4 and heated and pressed, so that the corrugated unevenness is obtained. A continuously bent corrugated sheet 3 is formed. At this time, the heating temperature is set at about 120 ° C. to about 200 ° C., and by such heating, the base material 2 and the corrugated sheet 3 react with the diisocyanate and the tricarboxylic anhydride B to form the polyamide imide C It cures (cures).

The formation of the corrugated sheet 3 will be described in more detail. That is, the semi-cured prepreg-shaped and sheet-like base material 2 prepared in the above-described process is supplied to the corrugating apparatus 4. The corrugating device 4 includes a pair of corrugating jigs, such as a gear 5 and a rack 6, and forms the corrugated sheet 3 by sandwiching the base material 2 and applying heat and pressure. And this heating temperature is 120
The temperature is set at a relatively low temperature of about 200 ° C. to 200 ° C., and by such heating, the semi-cured prepreg-shaped base material 2
The diisocyanate contained therein reacts with the tricarboxylic anhydride B to form a polyamide imide C, which is cured. So,
The corrugated sheet 3 having a configuration in which the polyamide-imide acid C is combined with the fiber base material A and having a shape retention property by curing is formed. In the present specification, regarding the curing, the terms semi-curing (semi-curing) described above, curing (curing) referred to herein, and complete curing (complete curing) described later are used according to the degree of curing.

In the illustrated example, first, as shown in FIG. 1 (3), the base material 2 is placed on a rack 6 which is a lower jig of a corrugating apparatus 4 and then a gear 5 which is an upper jig. Is attached to the rack 6 by utilizing its viscosity and tack. The base material 2 prepared as described above is then covered on both upper and lower surfaces with release sheets (not shown) made of vinyl sheets.
When placed on the upper surface, the release paper covering the lower surface side is removed. Then, after the base material 2 is stuck on the rack 6, the release paper covering the upper surface side is removed. Then, as shown in FIG. 1 (4), the rack 6 of the same type is placed as an upper jig via the base material 2 stuck on the rack 6 as a lower jig, and then heated at 120 ° C. From 200
By heating at about ° C, the diisocyanate and the tricarboxylic anhydride B react to form the polyamide imide acid C. Accordingly, as shown in FIG. 2A, the corrugated sheet 3 having a configuration in which the fiber base material A and the polyamide imide acid C are combined is molded and cured. The corrugated sheet 3 formed in this manner is formed by bending the corrugated irregularities linearly parallel to the short direction and continuously and repeatedly at the predetermined pitch and height in the long direction. The corrugated surface of the corrugated sheet 3, that is, the cross-sectional shape of the top and bottom portions is typically a trapezoidal shape (half hexagonal shape) as shown in the drawing, but is generally a triangular shape, a substantially square shape, and various other Shaped shapes are also possible.
The corrugated sheet 3 is formed in this manner.

In this manufacturing method, the base material 2 is heated together with the formation of the corrugated sheet 3 as shown in the step of FIG. 5 and the like in FIG. A flat plate 7 is formed. At that time, the heating temperature is 120
The temperature is set at about 200 ° C. to about 200 ° C., and the base material 2 and the flat plate 7 are cured (cured) by reacting the diisocyanate with the tricarboxylic anhydride B to form the polyamide imide acid C by such heating. .

The forming of the flat plate 7 will be described in more detail. In other words, the semi-cured prepreg-shaped sheet material 2 prepared in the above-described process is formed as a flat plate 7 by directly heating the material shown in FIG. You. And this heating temperature is 1
The temperature is set to a relatively low temperature of about 20 ° C. to 200 ° C., and the diisocyanate and tricarboxylic anhydride B in the semi-cured prepreg-like base material 2 are set by such heating.
Reacts with each other to form a polyamide-imide acid C and is cured. In this way, a sheet-shaped flat plate 7 having a configuration in which the polyamide base acid C is combined with the fiber base material A and having a shape retention property by curing is formed. The flat plate 7 is formed in this way.

Further, in this manufacturing method, FIG.
As shown in the steps of FIG.
A diisocyanate and a tricarboxylic anhydride B, which are stabilized and diluted with ketones, are applied as an adhesive 8 to the top surface and the bottom surface of the irregularities of the cured corrugated sheet 3, respectively.

The application of the adhesive 8 will be described in more detail. With respect to the corrugated sheet 3 that has been formed and cured, the adhesive 8 is applied to both or one of the top surface (upper surface) and the bottom back surface (lower surface) of the irregularities in a line shape. As the adhesive 8, diisocyanate and tricarboxylic anhydride B diluted with ketones as a solvent such as acetone or methyl ethyl ketone (MEK) according to the above-described base material 2 are used. The application of the adhesive 8 may be performed in a liquid state.
It may be applied as a semi-cured (semi-cured) prepreg by heating at about 80 ° C. to about 80 ° C. and removing excess ketones as a solvent. And corrugated sheet 3
In this method, the adhesive 8 applied in this manner is dried, cut at predetermined lengths, and proceeds to the next step, but may proceed to the next step without drying. The application of the adhesive 8 is performed in this manner.

The order of each of these steps will be described. Preparation of the base material 2 described above (step in FIG. 5)
The order of the subsequent steps, that is, the step of forming the corrugated sheet 3 (step of FIG. 5), the step of applying the adhesive 8 to the corrugated sheet 3 (step of FIG. 5), and the step of forming the flat plate 7 (step of FIG. 5) )
This order may be appropriately changed regardless of the illustrated example. For example, the flat plate 7 may be formed before the corrugated plate 3 (the step in FIG. 5 may be performed before the step), and the flat plate 7 is formed after the adhesive 8 is applied to the corrugated plate 3. (The step in FIG. 5 may be performed after the step).

Thereafter, in this manufacturing method, as shown in FIG. 2 (3), FIG. 3 (1), and the steps of FIG. The laminated sheets are successively and alternately stacked in the form of a laminated block. At this time, the corrugated sheets 3 are shifted by a half pitch of the wave so that the bottom and the top are opposed to each other via the flat plates 7, respectively. I do.

The intussusception will be described in more detail.
That is, the corrugated sheet 3 on which the molding, curing and adhesive 8 is applied as described above, and the molded and cured flat plate 7 are cut into the same dimensions, and then a plurality of sheets, for example, a large number of sheets are formed. Are stacked one on top of the other in the existing laminated block shape.
Then, in such a stacking, each corrugated sheet 3 between the upper and lower sides
Are shifted to the left and right by a half pitch of the wave while passing through the flat plate 7 respectively. Thus, each of the upper and lower corrugated sheets 3
The bottom rear surface and the top surface to which the adhesive 8 has been applied are stacked in a positional relationship facing each other with the flat plate 7 interposed therebetween. Intussusception is performed in this way.

Then, in this manufacturing method, as shown in FIG. 3A and the steps of FIG. 5, each corrugated plate 3 and each flat plate 7 thus stacked are heated and pressed. Are bonded with an adhesive 8. At that time, the heating temperature is set at about 120 ° C. to about 200 ° C., and by such heating, the diisocyanate of each adhesive 8 and the tricarboxylic anhydride B react to form the polyamide imide acid C.

Such bonding will be described in more detail.
That is, the corrugated plates 3 and the flat plates 7 stacked as described above are heated and pressed from above and below, so that the adhesive 8 applied to the bottom rear surface and the top surface of the corrugated plate 3 is cured. ,
Thus, they are bonded to each other. The heating temperature is from 120 ° C. to 200 ° C. according to the above-described molding of the corrugated sheet 3 and the flat plate 7.
It is set to a relatively low temperature. By such heating, ketones, which are unnecessary solvents, are removed from the adhesive 8 applied in a liquid or prepreg state as described above, and at the same time, diisocyanate and tricarboxylic anhydride B react with each other, and the polyamide imide acid It becomes C and cures (cures). The stacked corrugated plates 3 and the flat plates 7 are bonded in this manner.

In this manufacturing method, by following these steps, as shown in FIG.
Each of the corrugated plates 3 and each of the flat plates 7 bonded to each other are used as cell walls 9.
A honeycomb core 11 made of fiber reinforced plastic, which is a planar assembly of hollow columnar cells 10 defined by the cell walls 9 and is an intermediate product, is obtained.

The honeycomb core 11 will be described in more detail. In this honeycomb core 11 made of fiber reinforced plastic, the corrugated plates 3 and the flat plates 7 are stacked and bonded to form a cell wall 9, and a large number of hollow pillar-shaped partitions are formed in the cell walls 9 to form independent spaces. It consists of a planar assembly of cells 10. By the way, in the case of the present invention, as described later, the purpose is to obtain a honeycomb core 1 made of a fiber-reinforced plastic in which the cell wall 9 has a structure in which the polyamide base resin A is combined with the fiber base material A. Honeycomb core 11
Is only an intermediate product. In other words, the honeycomb core made of the fiber-reinforced plastic has the cell wall 9 (that is, the corrugated plate 3).
And the flat plate 7) are still an intermediate product of the honeycomb core 1 as a finished product having a configuration in which the fiber base A is combined with the polyamide imide acid C, and a configuration in which the fiber base A is combined with the polyamide imide resin D. Absent. In this manufacturing method, first, such a honeycomb core 11 as an intermediate product is obtained.

Next, in this manufacturing method, in many cases, the post-processing shown in FIG. 3B and the steps shown in FIG. 5 is performed. That is, as the post-processing, the honeycomb core 11
The outer surface of the cell wall 9 is heated after the diisocyanate and the tricarboxylic anhydride B, which are stabilized and diluted with ketones, are attached and impregnated for reinforcement. At this time, the heating temperature is set to about 120 ° C. to about 200 ° C., and such heating causes the diisocyanate and tricarboxylic anhydride B attached and impregnated for reinforcement to react with each other to form polyamideimidic acid C. Cure (cure).

The post-treatment for reinforcement will be described in more detail. The honeycomb core 11 as an intermediate product obtained as described above is immersed in a bathtub 12 as necessary. That is, the stabilized diisocyanate and tricarboxylic anhydride B are converted into acetone or methyl ethyl ketone (M
Bathtub 1 containing liquid diluted with ketones such as EK)
After being immersed in 2 (so-called soaked),
Removed and dried. Thus, the diisocyanate and the tricarboxylic anhydride B diluted with ketones are attached and impregnated on the outer surface of the cell wall 9 of the honeycomb core 11. The composition and the like of the chemical substance to be additionally attached and impregnated in this way are as follows.
The adhesive 8 to be applied is the same as described above. Then, the honeycomb core 11 is formed in the same manner as the above when forming the corrugated plate 3 or the flat plate 7 or when bonding with the adhesive 8.
Heating at a relatively low temperature of about 20 ° C. to 200 ° C. is performed. By such heating, unnecessary solvent ketones are removed, and diisocyanate and tricarboxylic anhydride B, which have been attached and impregnated as described above, react with tricarboxylic anhydride B to be cured into polyamide imide acid C. Such reinforcement post-processing is often performed.

In this manufacturing method, after passing through each of these steps, finally, FIGS. 4A and 4B, FIG.
As shown in the step, this honeycomb core 11
Is heated at a high temperature of about 200 ° C. to 300 ° C. As a result, the cell walls 9, the adhesive 8, and the polyamide-imide acid C for reinforcing and the like react with each other to close the ring,
The polyamideimide resin D is completely cured (completely cured).

Such a final step will be described in more detail. That is, the honeycomb core 11, which is an intermediate product, is additionally adhered and impregnated to the cell wall 9 having a configuration in which the fiber substrate A is combined with the polyamide imide acid C, the adhesive 8 made of the polyamide imide acid C, and the cell wall 9. And a reinforcing polyamide-imide acid C. Of course, a structure in which such additional attachment and impregnation for reinforcement is not performed is also possible. The honeycomb core 11 is, for example, a heating furnace 1
In Step 3, heating is performed at a high temperature of about 200 ° C. to 300 ° C. Accordingly, each of the above-mentioned polyamide imide acids C, that is, the polyamide imide acid C in the cell wall 9,
The polyamide imide acid C of the adhesive 8 and the polyamide imide acid C adhered and impregnated for reinforcement react with each other to form a ring, and the polyamide imide resin D is completely cured. In other words, the heat moldability to a curved surface, especially from 120 ° C. to 150 ° C.
It is made of polyamide-imide resin D having excellent mechanical strength in a temperature range of about ° C.

In this manner, the honeycomb core 1 made of fiber reinforced plastic and composed of the fiber base material A and the polyamide imide resin D is manufactured. The honeycomb core 1 made of fiber reinforced plastic is made of a fiber base material A
, A cell wall 9 having a structure in which a polyamide imide resin D is combined with the adhesive, an adhesive 8 made of a polyamide imide resin D for bonding between such cell walls 9, and a polyamide imide resin adhered to and impregnated on the cell wall 9 for reinforcement. D, etc.
Of course, it is also conceivable that no additional attachment or impregnation for reinforcement is performed. The cross-sectional shape of the cell wall 9 and the cell 10 of the honeycomb core 1 made of the fiber-reinforced plastic is typically a trapezoidal shape as shown in the drawing. Is also possible.

In many cases, the honeycomb core 1 is used as a honeycomb sandwich panel in which a surface plate is adhered to both open end faces. And the honeycomb core 1 and the honeycomb sandwich panel made of the fiber reinforced plastic are excellent in the weight ratio strength like the general one,
It is lightweight and has high rigidity and strength.
The honeycomb core 1 is known to have excellent rectifying effects, and the honeycomb sandwich panel is known to have excellent planar accuracy, etc., and is widely used as various structural materials. Since the honeycomb core 1 is made of fiber reinforced plastic, it is particularly excellent in lightness. Further, since the cell wall 9 is made of a bisect type having the corrugated plate 3 and the flat plate 7,
In particular, it has excellent rigidity and strength. Furthermore, as described above, since it is made of polyamide-imide resin D, it can be heated and formed into a secondary or tertiary curved surface at the time of commercialization, or at a temperature of about 120 ° C. to 150 ° C. at the time of use as a product. Excellent mechanical strength in the region. The honeycomb core 1 made of fiber reinforced plastic is configured as described above.

The present invention is configured as described above. Then, it becomes as follows. In the method for manufacturing the honeycomb core 1 made of fiber-reinforced plastic according to the present invention, first, a diisocyanate diluted with a ketone and a tricarboxylic anhydride B are combined with a fiber base material A to form a semi-cured (semi-cured) prepreg. The base material 2 is prepared (see FIG. 1 (1), FIG. 2 (2), steps in FIG. 5, etc.). The base material 2 is provided with viscosity and tack, but when further viscosity and tack are required, additives such as nitrile rubber and epoxy resin are added.

Then, such a base material 2 is supplied to a corrugating apparatus 4 to form a corrugated sheet 3 by heating and pressing, and a flat plate 7 by heating the base material 2. (Figures (2) and (3) in FIG. 1)
(4) See FIG. 2, (1) in FIG. 2, steps in FIG. 5, etc.). At that time, the heating temperature was set at about 120 ° C. to about 200 ° C., and the diisocyanate of the base material 2 and the tricarboxylic anhydride B reacted to form a polyamide imide acid C, which was cured and cured. Corrugated plate 3 or flat plate 7
Has tentative shape retention.

Thereafter, a diisocyanate diluted with ketones and tricarboxylic anhydride B as an adhesive 8 are applied to the top surface and bottom surface of the corrugated sheet 3 thus formed and cured. The plates 3 and the plates 7 are sequentially and alternately piled up, and at this time, the corrugated plate 3 is shifted by a half pitch of the wave (FIGS. 2 (2), (3), and (1) of FIG. 2). FIG. 5, steps in FIG. 5, etc.). Then, by applying heat and pressure, the corrugated plate 3 and the flat plate 7 are adhered with the adhesive 8. At this time, the heating temperature is set to about 120 ° C. to 200 ° C. The acid anhydride B reacts to become a polyamide-imide acid C and is cured (cured) (see FIG. 3 (1), FIG. 5, steps, etc.).

The corrugated plate 3 and the flat plate 7 thus stacked and adhered are used as the cell wall 9, and the honeycomb core 11, which is an aggregate of the cells 10, is an intermediate product made of fiber-reinforced plastic.
Is obtained. In many cases, the honeycomb core 11 obtained as described above is subjected to post-processing of the cell wall 9.
The diisocyanate diluted with ketones and tricarboxylic anhydride B are adhered and impregnated on the outer surface of the substrate for reinforcement, and then heated. The heating temperature is from 120 ° C to 200 ° C
Thus, the diisocyanate and the tricarboxylic anhydride B react to form a polyamide-imide acid C, which is cured (FIG. 3 (2), FIG.
Etc.).

After the above steps, the honeycomb core 11 made of fiber reinforced plastic, which is an intermediate product, is finally heated to a high temperature only once. The heating temperature is 200 ° C
The temperature is set to about 300 ° C., so that each of the polyamide-imide acids C for the cell wall 9, the adhesive 8, and the reinforcement reacts at the same time to close the ring at the same time, and is completely cured as the polyamide-imide resin D ( (Complete cure), and finally provide a reliable shape retention (see FIG. 4 (1)). Thus, the desired honeycomb core 1 made of fiber reinforced plastic is obtained. (Refer to FIG. 4 (2) and steps in FIG. 5). In other words, it has a structure in which the polyamide-imide resin D is combined with the fiber base material A, so that it has excellent heat moldability to secondary and tertiary curved surfaces at the time of commercialization, and particularly has a characteristic of 120 when used as a product. ° C
Thus, a honeycomb core 1 made of fiber-reinforced plastic and having excellent mechanical strength in a temperature range of about 150 to about 150 ° C. is manufactured.
Therefore, in the method of manufacturing the honeycomb core 1 made of fiber reinforced plastic according to the present invention, the following first, second, and
It becomes the third.

First, in the manufacturing method of the present invention, when the base material 2 is formed into the corrugated plate 3 or the flat plate 7, when the base material 2 is bonded with the adhesive 8, during the post-processing for reinforcement, etc. Is 12
Only heating at a relatively low temperature of about 0 ° C. to 200 ° C. is performed. That is, in each of these steps, high-temperature heating of about 200 ° C. to 300 ° C. is not necessarily performed as in the above-described conventional example (steps in FIG. 5 of the present invention,. , Etc. and the above-described steps of FIG.

This is because, in the present invention, diisocyanate and tricarboxylic anhydride B were used for the base material 2, whereas in this type of conventional example, the polyamide imide C obtained by reacting these was used. caused by. Then, in the manufacturing method of the present invention, the final step is performed only once at 200 ° C.
To a high temperature of 300 ° C. (see step of FIG. 5 of the present invention). By such high temperature heating, the base material 2
In forming the corrugated sheet into the corrugated sheet 3 or the flat plate 7, when bonding with the adhesive 8, at the time of post-processing for reinforcement, and the like (see the steps in FIG. 5 of the present invention), the polyamideimide All of what was designated as C at a time is the intended polyamideimide resin D. Thus, high-temperature heating only needs to be performed once.

Second, in the production method of the present invention, general ketones which are inexpensive and have a low boiling point are used as the solvent. That is, in the production method of the present invention, in preparing the base material 2, applying the adhesive 8, performing post-processing for reinforcement, and the like, diluting the diisocyanate and the tricarboxylic anhydride B in each step. For this purpose (see steps in FIG. 5, etc.), inexpensive and common ketones such as acetone and methyl ketone (MEK) are used. Also, when the prepreg is formed by removing ketones as a solvent after the fact, the boiling point of ketones is as low as about 60 ° C. to about 80 ° C., so that the heating cost is also reduced.

On the other hand, in this kind of conventional example described above,
In these steps, since the polyamidoimidic acid C must be diluted (see steps in FIG. 6, etc.), expensive NMP (N-methyl-2-pyrrolidone), DMF (dimethylformamide), etc. Special solvents must be used essentially. In addition, this special solvent has a high boiling point of 120 ° C. to 150 ° C., and the heating cost is increased in the subsequent prepreg formation. On the other hand, in the present invention, ketones which are inexpensive and have a low boiling point are used.

Third, in the production method of the present invention, the base material 2 supplied to the corrugating apparatus 4 is composed of a diisocyanate and a tricarboxylic anhydride B diluted with ketones.
Is combined with the fiber base material A. Therefore, the base material 2 is provided with the necessary viscosity and tack, and is securely stuck to the gear 5 and the rack 6 of the corrugating device 4, so that the corrugated plate 3 is formed smoothly (step in FIG. 5). ,, FIG. 1 (3), (4), etc.). Further, when further viscosity and tack are required, additives such as nitrile rubber and epoxy resin are soluble in ketones, so by adding such additives to the base material 2, Adjustment to the required viscosity and tack is easily possible.

On the other hand, in this kind of conventional example described above,
Since the base material has a structure in which the polyamideimide acid C diluted with a special solvent such as NMP or DMF is combined with the fiber base material A, the base material is extremely poor in tackiness and tackiness. It is hard to stick to 6.
Additives such as nitrile rubber and epoxy resin were also insoluble in such special solvents and could not be used (see steps in FIG. 6). On the other hand, in the present invention,
There is no worry about tack. Here, specific examples and examples of the manufacturing method of the present invention are shown in Tables 1 and 2 below.

[0055]

[Table 1]

[0056]

[Table 2]

The outlines of the specific examples and embodiments shown in Tables 1 and 2 are as follows. First, Table 1 and (1) in FIG.
This will be described with reference to FIG. In this specific example / embodiment, carbon fiber is used as the fiber base material A of the base material 2, and the carbon fiber has a length of 1 k to 12 k (for example, 1 k is about 1000 of one thread). 50 g / m ²
And about 600 g / m ² are used. The base material 2 formed on the corrugated sheet 3 is desirably about 200 g / m ² at 3 k, and the base material 2 formed on the flat plate 7 is 1 k
Of about 125 g / m ² . In the base material 2, diisocyanate and tricarboxylic anhydride B combined with such a fiber base material A by adhesion and impregnation are diluted with ketones, and are mixed with the base material 2 in a molar ratio of 1: 1. 20% content (based on fiber substrate A)
To about 80%, desirably about 50%.

Next, Table 1 and FIG. 1 (3), (4)
This will be described with reference to FIG. 2, FIG. 2 (1), FIG. 5, and the like. Such a base material 2 is formed into a semi-cured prepreg, and is first supplied to a corrugation supply device 4 including a rack 6 and a gear 5, and is placed on the rack 6 and the gear 5.
Is pressed on the rack 6. The pressure at that time is from 0.1 kgf / cm ² to 10.
About 0 kgf / cm ² , desirably 5.0 kgf / c
It is set to about m ² . Then, instead of the gear 5, a rack 6 of the same type is placed via the base material 2 stuck on the rack 6, and is heated and pressed. The pressure at that time is 0.1
20.0kgf / cm ² order of kgf / cm ^2, preferably is set to about 6.0 kgf / cm ^2. The heating temperature is about 120 ° C. to 200 ° C., preferably 160 ° C.
Set to about. The time is set to about 0.1 to 6.0 hours, preferably about 2 hours. By such heating and pressurization, the base material 2 is formed into the corrugated sheet 3, and the diisocyanate and the tricarboxylic anhydride B react with each other to be converted into the polyamide imide acid C to be cured.

Next, Table 2 and FIG. 2 (2), (3)
FIG. 3, FIG. 3 (1), FIG. 5, steps,.
And so on. The adhesive 8 is applied to the top and bottom surfaces of the irregularities of the corrugated sheet 3 thus formed and cured.
Is applied. As the adhesive 8, diisocyanate and tricarboxylic anhydride B diluted with ketones are used, and one surface of the top surface or the bottom surface of the corrugated sheet 3 is used.
0 g / m ² to about 500 g / m ² , preferably 250 g / m ²
g / m ² . Then, the corrugated plate 3 and the flat plate 7 on which the adhesive 8 is applied are alternately stacked, and then heated and pressed, whereby the diisocyanate and the tricarboxylic anhydride B of the adhesive 8 react. As a result, the polyamideimide acid C is cured. The pressure at that time, 10.0 kgf from 0.1kgf / cm ² / cm ²
Level, preferably about 1.0 kgf / cm ² . The heating temperature is set at about 120 ° C. to about 200 ° C., preferably about 160 ° C. The time is set to, for example, about 2 hours. In this way, the honeycomb core 11 as an intermediate product made of fiber reinforced plastic using the stacked and bonded corrugated plate 3 and flat plate 7 as the cell walls 9 is obtained.

Next, a description will be given with reference to Table 2, FIG. 3 (2), FIG. 5, and the like. The honeycomb core 11 thus obtained is heated after the diisocyanate and tricarboxylic anhydride B diluted with ketones are adhered and impregnated on the outer surface of the cell wall 9 as a post-treatment for reinforcement. You. At this time, the amount of adhesion and impregnation is set to 0.
It is set at about 1 PCF (pound / ft ³ ) to about 1.0 PCF, preferably about 0.4 PCF. The heating temperature is about 120 ° C. to 200 ° C., preferably 16 ° C.
It is set to about 0 ° C. The diisocyanate and tricarboxylic anhydride B thus deposited and impregnated are
Reacts with each other to form a polyamide-imide acid C and is cured.

Finally, regarding the final step, FIG.
This will be described with reference to FIG. In the specific examples and embodiments of the present invention, finally, the cell wall 9, the adhesive 8, the reinforcing material, etc. are heated at a high temperature set at about 200 to 300 ° C., preferably about 250 ° C. Are reacted so as to close the ring, and are completely cured as a polyamideimide resin D. Thus, the desired honeycomb core 1 made of fiber reinforced plastic was manufactured.

[0062]

As described above, the method of manufacturing a honeycomb core made of fiber reinforced plastic according to the present invention is different from that of the above in that the base material, the adhesive, the post-treatment for reinforcement, etc. The following effects are exhibited by using diisocyanates and tricarboxylic anhydrides as chemical substances.

First, high-temperature heating only needs to be performed once in the last step, and lower-temperature heating is required in each of the preceding steps, thereby reducing the manufacturing cost. That is,
In the manufacturing method of this type of conventional example described above, when forming the base material into a corrugated sheet or a flat plate, when bonding with an adhesive, during post-processing for reinforcement, and the like, in each step, 200 ° C. to 300 ° C.
Although high-temperature heating of a certain degree has been indispensably performed, in the manufacturing method of the present invention, high-temperature heating may be performed only once in the last step. In the production method of the present invention, when forming the base material into a corrugated sheet or a flat plate, when bonding with an adhesive, during post-processing for reinforcement, etc., at 120 ° C.
And heating at a relatively low temperature of about 200 ° C. As described above, in the manufacturing method of the present invention, high-temperature heating of about 200 ° C. to 300 ° C. does not need to be performed over a plurality of steps and a plurality of times, and need only be performed once in the last step. Heating costs and manufacturing costs are reduced.

Secondly, inexpensive and low-boiling ketones are used as the solvent, and the production cost is reduced in this respect as well. That is, in the manufacturing method of this type of conventional example described above, when preparing the base material, when applying the adhesive, during the post-treatment for reinforcement, and the like, the polyamidoimide acid must be diluted, which is expensive. And high boiling N
Special solvents such as MP (N-methyl-2-pyrrolidone) and DMF (dimethylformamide) have been essentially used. However, in the production method of the present invention, inexpensive ketones having a low boiling point are used.

That is, in the production method of the present invention, the diisocyanate and the tricarboxylic anhydride may be diluted in preparing the base material, applying the adhesive, performing post-treatment for reinforcement, and the like. Ketones such as acetone and methyl ethyl ketone (MEK) which are inexpensive and have a low boiling point are used as the solvent. As described above, in the production method of the present invention, general ketones, which are cheaper and can reduce the heating cost, are used as the solvent used in a large amount in a plurality of steps. Therefore, the manufacturing cost is reduced accordingly.

Third, a base material having an appropriate viscosity and tack can be obtained, and reliable production can be realized without any trouble in forming a corrugated sheet. That is, in the manufacturing method of this type of conventional example described above, when forming a corrugated sheet with a corrugating apparatus,
The supplied base material consists of a combination of polyamide imide acid diluted with a special solvent such as NMP or DMF on the fiber base material, so it has extremely low viscosity and tack, is hard to stick to gears and racks, There was a problem in molding.

On the other hand, in the production method of the present invention, the base material supplied to the corrugating apparatus has a structure in which diisocyanate and tricarboxylic anhydride diluted with ketones are combined with a fiber base material,・ It has a tack. Therefore, this base material is securely stuck to the gears and racks of the corrugating apparatus, so that the corrugated sheet can be formed smoothly without any trouble. If further viscosity and tack are required, the necessary viscosity and tack can be easily obtained by adding an additive such as nitrile rubber or epoxy resin to the base material. Such an additive can be easily dissolved in ketones used for dilution as described above. Thus, in the manufacturing method of the present invention, the manufacture of the honeycomb core made of fiber reinforced plastic having the corrugated plate or the flat plate as the cell wall is more reliably and stabilized. As described above, the effects exhibited by the present invention are remarkable and large, for example, all the problems existing in this type of conventional example are solved.

[Brief description of the drawings]

FIG. 1 is a perspective view for explaining an embodiment of a method for manufacturing a honeycomb core made of fiber-reinforced plastic according to the present invention, and FIG.
(2) shows the cut base material sheet, (3) shows the step of forming a corrugated sheet with gears and racks, and (4) shows the step of forming the corrugated sheet with racks and racks.

FIGS. 2A and 2B are perspective views for describing the embodiment of the present invention. FIG. 2A is a perspective view of a molded corrugated sheet, FIG. The figure shows a corrugated sheet and a flat plate to be stacked.

FIG. 3 is provided for describing an embodiment of the present invention, wherein FIG. 1A is a front view of the obtained honeycomb core, and FIG. 3B is a perspective view of the honeycomb core being immersed in a bathtub.

FIG. 4 is provided for describing an embodiment of the present invention, in which (1) is a perspective view of a honeycomb core being heated, and (2) is a front view of a finally obtained honeycomb core.

FIG. 5 is a process block diagram for explaining the embodiment of the present invention.

FIG. 6 is a process block diagram for explaining a manufacturing method of this type of conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Honeycomb core 2 Base material 3 Corrugated plate 4 Corrugating device 5 Gear 6 Rack 7 Flat plate 8 Adhesive 9 Cell wall 10 Cell 11 Honeycomb core 12 Bath tub 13 Heating furnace A Fiber base material B Diisocyanate and tricarboxylic anhydride C Polyamideimidic acid D Polyamideimide resin

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B32B 27/04 B32B 27/04 Z C08J 5/04 CEZ C08J 5/04 CEZ // C08G 73/10 C08G 73/10 C08K 3 / 04 C08K 3/04 7/06 7/06 C08L 79/08 C08L 79/08 Z B29K 79:00 105: 06 B29L 31:60

Claims (3)

[Claims] First, a diisocyanate and a tricarboxylic anhydride, which are stabilized and diluted with a ketone, are combined with a fibrous base material by adhesion, impregnation, mixing, or the like to obtain a semi-cured prepreg-like sheet-like mother material. Then, the base material is supplied to a corrugating apparatus and heated and pressed to form a corrugated sheet in which corrugations are continuously bent. At this time, the heating temperature is reduced. 120 ° C to 20
The temperature is set at about 0 ° C, and by such heating,
The base material and the corrugated sheet react with the diisocyanate and the tricarboxylic anhydride to form a polyamidoimide, and are cured. Further, by heating the base material, a sheet-shaped flat plate is formed. In this case, the heating temperature is from 120 ° C to 200 ° C.
With such heating, the base material and the flat plate are cured by the reaction of the diisocyanate and tricarboxylic anhydride to form a polyamidoimide, and are molded and cured as described above. After applying diisocyanate and tricarboxylic anhydride, which are stabilized and diluted with ketones, as an adhesive to the top surface and bottom back surface of the corrugated plate, respectively, The flat plates are successively stacked in a laminated block shape, and at this time, the corrugated plates are shifted by a half pitch of the wave, and the bottom and the top face each other while passing through the flat plates. Then, by heating and pressing, the corrugated plates and the flat plates thus stacked are adhered to each other with the adhesive. The temperature is set to about 200 ° C. to about 200 ° C., and by such heating, each of the adhesives reacts with the diisocyanate and the tricarboxylic anhydride to form a polyamide imide acid and is cured. Each of the stacked and bonded corrugated plates and each of the flat plates is used as a cell wall, and a honeycomb core made of fiber reinforced plastic, which is a planar assembly of a large number of hollow columnar cells defined by the cell walls, is obtained. Then, by heating the honeycomb core at a high temperature of about 200 ° C. to 300 ° C., the cell walls and the adhesive react with each other to close the polyamide imide acid to form a polyamide imide resin. A method for producing a honeycomb core made of fiber-reinforced plastic, which is completely cured. 2. The method for producing a fiber-reinforced plastic honeycomb core according to claim 1, wherein the fiber-reinforced plastic honeycomb core obtained by stacking and bonding is 200 ° C. to 300 ° C.
Prior to heating at a high temperature, a diisocyanate and a tricarboxylic anhydride, which were stabilized and diluted with ketones, were adhered and impregnated to the outer surface of the cell wall of the honeycomb core for reinforcement as a post-treatment. After that, the heating temperature is set at about 120 ° C. to about 200 ° C., and the heating causes the diisocyanate and tricarboxylic anhydride attached and impregnated for reinforcement to react with each other to form polyamide imide. The honeycomb core is cured by heating at a high temperature of about 200 ° C. to 300 ° C., whereby the cell walls, the adhesive, and the polyamide-imide acid for reinforcement are respectively closed. A method for producing a honeycomb core made of fiber reinforced plastic, wherein the honeycomb core reacts as much as possible to be completely cured as a polyamideimide resin. 3. The method for manufacturing a honeycomb core made of fiber-reinforced plastic according to claim 1, wherein the base material prepared for forming the corrugated sheet is made of a nitrile rubber or epoxy to improve viscosity and tack. A method for producing a honeycomb core made of fiber reinforced plastic, characterized by adding an additive such as a resin.