JPH0623763A - Manufacture of composite molded product having porous core part - Google Patents

Abstract

PURPOSE:To manufacture at favorable productivity and a low cost, by a method wherein the title product is constituted of a surface layer part comprised of a nonfoaming or low-foaming urethane resin layer containing a fibrous reinforcing material, a porous core part of a foam of an urethane foam and a separation layer which is in existence between the surface layer part and core part and they are integrated. CONSTITUTION:A separation layer whose quantity of permeation of air per unit time is within a range of 10-500cc/cm<2>/sec is arranged with a molding tool. The separation layers 7a, 7b serving both as a reinforcing material wherein though this permeation resistance is low, a volume occupation ratio is high and the separation layers 6a, 6b whose permeation resistance is higher than those are arranged on almost all part. When a wood screw 12 is applied to the separation layere, since the separation layers 6a, 6b are not arranged on an expected part, a flat-platelike composite sandwitch foam core molded product possessing structure wherein a part into which the wood screw is inserted enteres far deeply a core part whose high density surface layer part containing the reinforcing material is a foamed component is obtained. With this construction, a thin composite molded product manufacturing of which has been extremely difficult by a conventional method can be manufactured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a composite molded article having a porous core. More specifically, (i) a surface layer portion made of a non-foamed or low-foamed urethane resin layer containing a fibrous reinforcing material, (ii) a porous core portion made of a foamed urethane resin layer, and (iii) the surface layer portion. The present invention relates to a method for efficiently producing an integrated composite molded article composed of a separation layer existing between the core and the core.

[0002]

2. Description of the Related Art A composite molded article having a core made of a porous foamed core and a surface layer made of fiber reinforced resin has excellent lightness and toughness, and thus has been put to practical use in various fields. In recent years, further improved molded products and manufacturing methods have been proposed.

As a method for producing a composite molded article having the above-mentioned structure, for example, a foamed core of a core portion is molded in advance,
After wrapping this molded body with a woven cloth as a reinforcing material, it is inserted into a mold, and then a liquid molding resin is injected into the mold to form a surface layer part, and a composite molded product is taken out from the mold, or There is known a method in which a composite molded article is obtained by molding a member to be formed in advance, injecting a foaming urethane resin or the like into the void in the center thereof, and forming a foamed core portion in the void. .

Further, JP-A-63-162207 discloses a method called thermal expansion transfer molding method. That is, in the method described in this publication, a thermoelastic rigid foam is preformed into a predetermined shape, the preformed foam is wrapped with a woven fabric, and then the internal constraining surface forms the outer shape of the final member and A specific part of the preformed foam core is placed in a mold that can be heated, a thermosetting liquid molding resin is injected into the mold, the foam core is expanded by heating, and the woven fabric that wraps the foam core is expanded by the expansion force. It is a method of obtaining a molded product by pressing the resin against the inner restricted surface and curing the resin.

This method has an advantage that a light and tough composite molded article which has never been obtained can be obtained, but (a) it is necessary to preform a foam core having a shape as close as possible to the shape of the mold. (B) It is necessary to select a foam core material having a thermal expansion behavior in an appropriate range, and (c) use a foam core having closed cells so that the thermosetting resin does not penetrate. There are restrictions such as what is necessary.

In Japanese Utility Model Publication No. 62-24521, an unsaturated polyester resin containing a large number of polyolefin resin foamed particles or a pulverized product thereof is provided between two surface layers of a fiber-containing unsaturated polyester resin. A fiber-reinforced unsaturated polyester resin lightweight molded product, characterized in that a core layer is integrally formed, is described.

This lightweight molded article is prepared by placing glass fibers in a molding die, coating the unsaturated polyester resin stock solution with the glass fiber to form a surface layer, and then forming expanded particles of the polyolefin resin and the unsaturated polyester. It is obtained by a method in which a mixed solution with a resin stock solution is poured (core layer), a glass fiber-containing unsaturated polyester resin is coated thereon (surface layer), and then the mold is clamped and cured.

However, in this method, since the particles which have already been foamed are used, it is difficult to apply a uniform pressure to the whole during molding. Therefore, it is not easy to stably obtain a homogeneous composite molded body by this method. Furthermore, this method is suitable as a method for obtaining a board-shaped molded article having an unsaturated polyester resin containing expanded particles as a core between upper and lower surface layers, but a method for obtaining a molded article having a curved surface. Is not suitable as

[0009] In the conventional technology as described above, (i) the step of obtaining a composite molded article is diverse and the operation is complicated,
Therefore, it has the disadvantage of low production efficiency and high cost of the molded product, (ii) the strength and appearance of the obtained composite molded product are unsatisfactory, and (iii) the shape and size of the composite molded product. Had the drawback of being limited.

[0010]

Therefore, the first object of the present invention is to compare a composite molded article substantially formed of a relatively dense surface layer portion and a porous core portion (core portion) containing a foam. It is to provide a method that can be obtained by a simple operation.

A second object of the present invention is to provide a method capable of obtaining a composite molded article having the above-mentioned structure in substantially one step and without requiring complicated operations and complicated conditions. To provide.

Another object of the present invention is that the production efficiency is excellent,
In particular, it is to provide a method having a high production rate of composite molded articles per molding machine.

Still another object of the present invention is to provide a method for producing a composite molded article which is light in weight, has high physical strength, and has a structure excellent in appearance.

Still another object of the present invention is to provide a method for producing a composite molded article, the shape and size of which can be arbitrarily selected.

The objects of the present invention will become more apparent from the following description.

[0016]

According to the studies made by the present inventors, the object of the present invention is to: (i) a surface layer portion comprising a non-foamed or low-foamed urethane resin layer containing a fibrous reinforcing material; (Ii) a porous core which is a urethane foam foam,
And (iii) a method for producing an integrated composite molded article comprising a separation layer existing between the surface layer portion and the core portion, which comprises the following steps (a) to (f): It has been found to be achieved by a characterized manufacturing method. (A) A separation layer having a specific permeation resistance, that is, a separation layer having a permeation resistance within the range of 10 to 500 cc / cm ² / sec in terms of air permeation amount (room temperature) per unit time, is provided in a molding die. Place it. (B) disposing a fibrous reinforcing material integrated with the separation layer or a separate fibrous reinforcement between the separation layer and the inner surface of the mold in the mold. (C) Supplying a foamable urethane resin to a region surrounded by the separation layer arranged in the mold. (D) causing volume expansion by foaming curing of the resin in a substantially closed state of the molding die (making the resin foam, ie, increasing the viscosity while increasing the viscosity to cause the volume expansion), and While pressing the separating layer toward the inner surface of the mold, a part of the foamable urethane resin is permeated through the separating layer and impregnated into the fibrous reinforcing material, thus separating between the separating layer and the inner surface of the mold. The presence of a foamable urethane resin inside the layer. (E) And the foamable urethane resin reaching the inner surface of the mold is
Forming the surface layer portion and the core portion by completing the solidification while suppressing foaming by the cooling effect by the contact with the inner surface of the mold which is kept at a temperature lower than the resin temperature. (F) Taking out the composite molded article thus obtained from the mold.

In the method of the present invention, the foamable urethane resin is foamed in the mold by mixing the isocyanate compound and the polyester or polyol having a hydroxyl group, and thereby the volume expansion of the foamable urethane resin is caused. One of the features is that the composite molded product is molded by maximally and effectively utilizing this force of volume expansion. Then, in the method of the present invention, the force due to the volume expansion of the foamable urethane resin acts as a force for pressing the separation layer surrounding the foam toward the inner surface of the mold. Further, due to the volume expansion of the foamable urethane resin, a part of the urethane resin itself present in the mold is impregnated and passed into the separation layer, and is sufficiently permeated into the fibrous reinforcing material located outside thereof. , The foaming in that part is suppressed by the cooling effect by contacting the inner surface of the mold,
Formation of a dense surface layer portion and a highly foamed and low density uniform core portion is achieved.

Thus, according to the method of the present invention, a composite molded article having the following characteristics can be obtained. (I) A surface layer portion made of a urethane resin layer containing a fibrous reinforcing material and substantially not containing bubbles is formed uniformly and tightly over the entire surface of the molded product. (Ii) In the first place, since the urethane foam resin is used as the core foam, a homogeneous porous core which is the same as the conventional one is formed. (Iii) The surface layer portion and the core portion are strongly integrated by communicating the same resin.

Next, the molding process in the present invention will be described in more detail.

The molding process of the present invention is effected in one step in a substantially closed molding mould.
The mold used at that time can be substantially sealed at the time of molding as long as it can withstand the molding pressure and temperature. Usually, the hand lay method and the RTM method (Resin Tr
ansfer Molding method) or RIM method (Reaction Injecti)
on Molding method) can be used. The mold material may be any of a metal mold, a wood mold, a resin mold, and a silicon mold.

The advantages of the method of the invention are, as mentioned above,
This is achieved by causing the foamable urethane resin to expand in volume within the mold and exerting the volume expansion force to the maximum extent and effectively by using the separation layer. Therefore, the use of the separation layer is indispensable for achieving the object of the present invention.

Thus, in the separation layer of the present invention, it is difficult to pass a foamed urethane resin whose viscosity has increased due to the reaction and foaming of the foamed urethane resin to some extent, but a foamable urethane resin having a low viscosity immediately after the start of foaming and reaction is compared. It is necessary to have a specific permeation resistance that can easily pass through.

Further, the performance desired as the separation layer is such that it can withstand the pressure as a result of the volume expansion of the foamable urethane resin, and during the volume expansion, the separation layer is ruptured or a hole is formed to cause foaming. When the above resin passes through the separation layer, it becomes difficult to obtain the desired good composite molded article.

In order to achieve the above-mentioned performance, the permeation resistance of the resin liquid due to the openings of the separation layer, the strength, and the size of the pores depends on the type and size of the foamable urethane resin used and the filler added thereto. And should be selected based on shape. In practice, a material having a permeation resistance of 10 to 50 cc / cm ² / sec at room temperature is used.

Those having a large permeation resistance such that the air permeation amount is less than 10 cc / cm ² / sec, the resin permeation amount becomes small at the time of molding, and the resin in the surface layer portion is apt to be insufficient, so that Dry spots occur on the product.
On the other hand, those with a permeation resistance as low as more than 500 cc / cm ² / sec, the separation layer and the fibrous reinforcing material cannot be pressed sufficiently against the inner surface of the mold due to foaming of the resin, so the bending rigidity of the molded product decreases. To do.

Specific examples of the material of the separation layer include woven fabric, knitted fabric, non-woven fabric, web, paper, wire mesh and porous membrane. Of these, preferred are woven, knitted, non-woven or web, and these materials may be synthetic fibers, natural fibers or inorganic fibers.

The shape and structure of the separation layer are determined depending on the structure of the mold used for molding and the structure or shape of the desired composite molded article. Generally, it is a bag-shaped structure or a planar structure, and the bag-shaped structure is particularly preferable. The bag-shaped structure or the planar structure does not have to be the separation layer as a whole, and a part of the bag-shaped structure or the planar structure may be made of another material that does not pass through the resin, such as a film or a microporous film. .

Further, the separating layer may be a structural material integrated with the fibrous reinforcing material forming the surface layer portion. The use of this integrated structural material is one of the preferred embodiments of the method of the present invention. A typical integrated structural material is a fibrous reinforcing material having at least its surface function as the separation layer described above.

The fibrous reinforcing material forming the surface layer will be described later in detail. When, for example, a woven fabric, a knitted fabric, a non-woven fabric or a web is used as the reinforcing material, the inner surface portion (foamable urethane resin) is used. If the foamable urethane resin is allowed to substantially pass under the permeation resistance described above, the reinforcing material itself can also serve as the separation layer. When such a fibrous reinforcing material is used, it is not necessary to separately provide a separate layer. However, the separating layer and the fibrous reinforcing material can be used separately in cooperation with each other, or can be used by being laminated and integrated.

As the fibrous reinforcing material forming the surface layer portion of the composite molded article of the present invention, fibrous materials generally used for reinforcing plastics are used. As the fibrous reinforcing material, glass fibers having high modulus and high strength, carbon fibers, silicon carbide fibers, polyolefin fibers and mixed fibers of two or more kinds of these are preferable. Besides these fibers, polyester fibers, polyamide fibers, viscose fibers or natural fibers can also be used. These may be short fibers or long fibers,
Whiskers may be used, but long fibers, particularly continuous fibers, are preferable.

Generally, these fibrous reinforcing materials are preferably used as a fibrous structure. That is, this reinforcing material is a woven fabric (plain weave, woven weave, twill weave, etc.), knitted fabric,
Nonwovens, UD yarns (unidirectionally aligned filaments), continuous mats or webs are preferred. These forms are not limited to flat ones, and may be a three-dimensional woven fabric, a three-dimensional knitted fabric, or a blade tube.

Short fibers or whiskers (for example, silicon carbide whiskers, carbon whiskers, silicon oxide whiskers, etc.) are not suitable for use as a reinforcing material in the surface layer by themselves, but some of webs and non-woven fabrics are used. It can be used as a material.

In the production of the composite molded article of the present invention, the expandable urethane resin used for the surface layer portion and the core portion is used for producing general hard and flexible foams as long as it exhibits fluidity at the time of molding. Any urethane resin will do. Such a foamable urethane resin is usually a mixture of an aromatic or aliphatic diisocyanate compound and a polyester or polyol having a hydroxyl group,
It has the property of reacting / foaming and solidifying by mixing. The mixture may contain a foaming agent, a catalyst, water and the like, and may contain additives such as a pigment and a color developing agent.

In carrying out the molding by the method of the present invention, a mold is prepared which can substantially seal the inside of the mold at the time of molding, a reinforcing material is arranged along the inner surface of the mold, and the inside (the center side of the mold) is arranged. ) To the separation layer. When the separating layer and the fibrous reinforcing material are integrated (typically, when the fibrous reinforcing material having the function of the separating layer is used), the surface having the function as the reinforcing material is the integrated product. It is preferable that the mold is installed so as to be in contact with the inner surface of the mold and the surface having a function as a separation layer is located inside (center side of the mold).

How to dispose the separating layer and the fibrous reinforcing material is determined depending on the shape, size, physical properties and intended use of the intended composite molded article, and in any case, it is described above. As described above, the method of the present invention effectively utilizes the volume expansion of the foamable urethane resin in the molding process, so that the separation layer is pressed toward the inner surface of the mold by the volume expansion of the foamable urethane resin. A separation layer and fibrous reinforcement should be placed.

Naturally, the separating layer should be arranged according to the shape of the mold so that the foam does not enter the surface layer of the composite molded article. Even if the separation layer has the ability to allow only the flowable urethane resin immediately after foaming to permeate, the separation layer is incompletely arranged in the mold, so that the surrounding area during molding is It is undesirable and should be avoided that the foam flows from the part to the surface part.

From this point of view, for example, when a rod-shaped or columnar molded article is to be manufactured, the separation layer and the fibrous reinforcing material are fitted to the bag structure (hollow cylindrical shape) in conformity with the shape of the molded article. It may be arranged on the inner surface of the mold. When manufacturing a flat plate molded product, it is preferable to dispose the separation layer and the fibrous reinforcing material on the inner surface of the mold so that the separation layer and the fibrous reinforcing material are attached to the entire surface.

1 and 2 are schematic views showing an example of this type of molding process. FIG. 1 is a schematic view showing an example of the arrangement of a separation layer and a fibrous reinforcing material in a mold when manufacturing a flat plate having irregularities.

In FIG. 1, 1a and 1b are molds for molding, which are constituted by a combination of an upper mold 1a and a lower mold 1b. First, the fibrous reinforcing materials 2a and 2b are arranged on the inner surfaces of these molds, and the separation layers 3a and 3b are provided on the inner side thereof.
In this case, the sheet-shaped separation layer is used, but the separation layer may be a bag-shaped structure. Then, the foamable polyurethane resin (stock solution) 4 is supplied to a position surrounded by the separation layers 3a and 3b (that is, a foam core forming position) during molding.

Thereafter, the mold is closed as shown in FIG. 2, and urethane resin is foamed and molded.

In the case of a flat plate or a flat molded product having front and back surfaces, the separating layer may be provided only on one side of the inner surface of the mold. In this case, an example in which a separation layer is not provided on the other side,
There may be an example in which a material such as a film that does not pass the flowable synthetic resin immediately after foaming is placed in place of the separation layer, but it may be selected according to the purpose. For example, in the case of a motorcycle cowling, by installing a printed film on the front surface side and using a separating layer of a glass fiber woven fabric on the back surface side, it is possible to simplify the work of painting the surface or attaching decals after molding. When a flat plate is molded as a structural material requiring high rigidity, separation layers may be provided on both surfaces, and a fibrous reinforcing material may be arranged between each separation layer and the inner surface of the mold.

As described above, after the separation layer and the fibrous reinforcing material are arranged in the mold, the foamable urethane resin is located at the position opposite to the mold inner surface of the separation layer, that is, the foamable urethane resin is separated during the molding. Is supplied to a position surrounded by. When the separation layer is a bag-shaped structure, it is injected inside.

Since the foamable urethane resin is a normal urethane resin for hard or soft foams as described above, it has fluidity and is supplied into the mold through a flow pipe after the mold is closed. It is also possible. But,
It is necessary to be careful to supply the resin into the mold through a thin flow pipe in a stable operation. Therefore, in the usual case, it is desirable to put the foamable urethane resin in the mold before closing the mold as shown in FIG. At this time, when the separation layer is a bag-shaped structure, the bag-shaped structure in which the foamable urethane resin has been previously injected may be put into the mold.

The expandable urethane resin may be mixed with non-expandable lightweight particles. As the non-expandable lightweight particles, foamed resin foamed particles and bubble-containing hollow inorganic particles called glass balloons, shirasu balloons and the like can be used, and the latter hollow inorganic particles are particularly preferable. In this case, the mixing ratio of the resin and the particles is 10/1 to 1 by weight.
/ 2 is preferable.

The amounts of the separation layer, the fibrous reinforcing material, the foamable urethane resin and the other components which are allowed to exist in the mold are as follows.
It can be variously changed according to the properties and intended use of the intended composite molded article. However, what is necessary is that the amount of each of the above-mentioned components charged in the mold is such that voids do not exist after the expandable urethane resin undergoes volume expansion during molding.

Particularly, the composite molded article of the present invention has the following (a) to
It is desirable to select and use the separation layer, the fibrous reinforcing material, and the foaming urethane resin so as to have the composition of (c). (A) In the substantial part of the composite molded article, the core portion is about 30-
90% by volume, preferably about 40 to 90% by volume, and (b) the specific gravity of the core is about 0.05 to 0.8 g /
ml, preferably about 0.1-0.6 g / ml,
(C) About 3 fibrous reinforcements and separation layers in the surface layer
Occupy 0-80% by volume, preferably about 30-60% by volume.

In the method of the present invention, the core may contain reinforcing fibers or whiskers or other additives, and in this case, it is preferable to mix them in advance with the foamable urethane resin.

Thus, in the method of the present invention, a composite molded article can be molded simply by charging each component in the mold and closing the mold as described above. However, in order to improve the speed of foaming and flow of the foamable urethane resin, it is possible to raise the temperature of the mold in advance, but keep the temperature lower than the temperature of the urethane resin during foaming, and It is necessary to cool the resin that has reached the temperature to solidify while suppressing foaming in that portion.

At this time, it is necessary that at least a part of the foamable urethane resin component maintains fluidity while the volume expansion of the foamable urethane resin occurs. Thus, the separation layer is pressed toward the inner surface of the mold by the volume expansion of the foamable urethane resin, and a part of the resin flows from the inside (core portion) to the outside (the surface layer portion side of the molded product) through the separation layer. To do.

Thus, while the dense surface layer portion is formed, the core portion made of the urethane resin foam is formed, and further, the surface layer portion and the core portion are connected by the same resin through the separation layer and are firmly integrated. A composite molded product can be obtained.

[0051]

As one of the characteristics of the composite molded article obtained by the method of the present invention, the improvement of mechanical properties can be mentioned. That is,
As a reinforcing material, glass continuous mat
00 g / m ² ), the usual molding method without using a separation membrane having a specific permeation resistance and the synthesis of a flat plate having a thickness of 20 × 250 × 340 mm molded by the method of the present invention are The molded product according to the present invention has a composition of 22 × 10 ⁵ kg · mm, while the molded product according to the present invention has a composition of 6.
It has a rigidity of 5 × 10 ⁵ kg · mm, which is about three times higher.

Further, by arranging a film or a thin sheet on the innermost surface of the mold at the time of molding, it is possible to obtain a product having a structure in which the film or sheet is attached to the outside of the surface layer portion of the composite molded article. In this way, even if a mold whose inner surface is not polished is used, a molded product with a beautiful surface can be obtained, and by applying coloring, patterns, etc. to the film and sheet, a molded product with excellent designability can be obtained. You can also do it.

Further, by using a separation layer having different resistance values and a separation layer which also serves as a reinforcing material in combination, the application described below becomes possible.

That is, when a wood screw or the like is used for a composite sandwich foam core molded product, when the pull-out strength of the wood screw is evaluated, there is a problem of insufficient strength due to peeling between the surface layer portion and the core portion. Existing. However, in the method of the present invention, as will be described with reference to FIG. 3, in the normal portion, the separation layers 7a and 7b also serving as a reinforcing material having a small permeation resistance but a high volume occupancy ratio and a permeation resistance higher than those of the separation layers 7a and 7b. The high separation layers 6a and 6b are arranged so as to overlap each other,
At the site where the wood screw 12 is expected to be applied, only those having a small permeation resistance 7a, 7b are provided and the separation layers 6a, 6b are provided.
If you do not place the wood screw 1
As shown in FIG. 4, only the portion where 2 is inserted can have a structure in which the surface layer portion having a high density is deeply inserted into the foamed core layer 8 of the core portion which is the foaming component. That is, this molded product has thick impregnated layers 9a and 9b at both ends, and thin impregnated layers 10 and 11 at the top and bottom of the central portion. By adjusting the degree of pressing of the reinforcing material to the inner surface of the mold in this way, it is possible to locally increase the mechanical strength against pulling out a wood screw or the like.

Thus, according to the present invention, a lightweight and tough composite molded article can be obtained in substantially one step. Such composite molded articles can be applied to various applications such as various structural materials, parts and constituent materials for vehicles and aircraft, sports equipment, furniture and the like.

As described above, according to the present invention, it is not necessary to form a foamed core in advance, and it is possible to produce a tough, integrally molded sandwich foam core composite molded article with high productivity at low cost. it can. Further, there is an advantage that it is possible to easily manufacture a thin composite molded product, which is very difficult to manufacture by the conventional method.

[0057]

EXAMPLES Next, the method of the present invention will be described in more detail by way of examples. However, these examples are for more specifically explaining the present invention, and the present invention is not limited to these examples.

[0058]

Example 1 This example is an example of producing a flat composite sandwich foam core molded article by the method of the present invention.

An aluminum mold for a flat plate having a length of 340 mm, a width of 250 mm and a thickness of 20 mm was prepared. Next, length 340mm, width 2
Glass fiber surface mat with specific permeation resistance cut to 50 mm (Asahi Fiber Glass MS3600
E) Prepare two sets of two (permeation resistance is an air permeation amount per unit time of about 300 cc / cm ² / sec at room temperature), install them on both inner surfaces of the mold, and match both surfaces of the mold. After closing the mold and tightening it, from the lower injection port of the mold, using a urethane foam injection machine (Shibaco CHEMIX SSU-03), isocyanate (C-46 manufactured by Negami Kogyo Co., Ltd.) and polyol (Toyo Tire & Rubber Co., Ltd.) Made "Soflan" R1109
-50 HRE) was added at a ratio of 100: 78 with mixing and stirring. When foamed urethane resin began to come out from the upper air vent, the mouth was closed and injection was stopped. After leaving for about 5 minutes after injection, the mold was opened and the molded product was released from the mold.

The resulting molded article had a thin urethane resin skin formed on both outer sides (both sides), and the glass fiber mat was present immediately below the skin along the skin and pressed against the foam core of the inner layer. There is a foamed core layer in which urethane resin is foamed and hardened in the center part, and a surface layer part in which the urethane resin is impregnated and hardened in the separation layer / fiber reinforcement layer made of each glass fiber woven fabric exists on the outside thereof, and the surface is thin urethane. It was a flat plate-shaped composite molded article composed of a resin layer (skin).

[0061]

Example 2 This example is an example of producing a flat composite sandwich foam core molded product having a different surface layer reinforcing material and separation layer constitution from Example 1 by the method of the present invention.

A mold similar to that of Example 1 was prepared, and then the vertical 3
Polyester non-woven fabric cut to 40 mm and 250 mm wide ("Unicel" BT0908W manufactured by Teijin Ltd.) (permeation resistance is an air permeation amount per unit time of about 50 cc / at room temperature)
cm ² / sec), glass fiber continuous mat (Asahi Fiber Glass CSM-M8608-X5J), and two non-woven fabrics in the order of 3 sheets prepared and placed on both inner surfaces of the mold. After matching the both sides and closing the mold and tightening, isocyanate (C-46 manufactured by Negami Kogyo Co., Ltd.) and polyol (Toyo Tire & Rubber Co., Ltd.) were injected from the lower injection port of the mold using a urethane foam injection machine (Shibaco CHEMIX SSU-03). "Soflan" R1109-50 manufactured by Co., Ltd.
HRE) was injected at a ratio of 100: 78 with mixing and stirring. When foamed urethane resin began to come out from the upper air vent, the mouth was closed and injection was stopped. After leaving for about 5 minutes after injection, the mold was opened and the molded product was released from the mold.

The resulting molded article was obtained in a smooth and glossy state in which the outer surface of the thin urethane resin was impregnated in the uppermost non-woven fabric on both outer sides, and the glass fiber mat was formed immediately below the outer surface of the skin along the surface of the surface. It was confirmed that a molded product of a composite sandwich core having a cross-sectional structure existing in a form pressed against the foam core of the inner layer was obtained. The specific gravity of this molded product was 0.3.

[0064]

[Third Embodiment] In this embodiment, as described in FIGS.
The separation layers 7a and 7b having a small permeation resistance but a high volume occupancy ratio also serving as a reinforcing material and the separation layers 6a and 6b having a permeation resistance higher than these are arranged at most of the parts.
By leaving 6a and 6b in place where it is expected to be applied, the part where the wood screw is inserted has the dense surface layer part including the reinforcing material penetrate deeper into the core part which is the foaming component. It is an example of producing a flat plate-shaped composite side-itch foam core molded product having a flat structure by the method of the present invention.

A mold similar to that used in Example 1 was prepared, and the separation layer 7 having a small permeation resistance but also serving as a reinforcing material having a high volume occupation ratio.
Glass fiber continuous mat (asahi fiberglass CSM-M8608-X5J) as a and 7b (permeation resistance: air permeation amount per unit time, about 5 at room temperature)
00 cc / cm ² / sec) and the permeation resistance is higher than 7a and 7b as the separation layers 6a and 6b, which are polyester non-woven fabrics ("Unicel" BT0908W manufactured by Teijin Ltd.) (permeation resistance in terms of air permeation amount per unit time). About 50cc / cm at room temperature
² / sec.) 340 mm in length, 250 mm in width and 1 in length
The pieces were cut into a piece of 00 mm and a piece of 250 mm in width, and as a set, they were placed on both inner surfaces of the mold as shown in FIG.

After both sides of the mold were tightened together, a urethane foam injection machine (Shibaco CHEMI
X SSU-03) and isocyanate (C-46 manufactured by Negami Kogyo Co., Ltd.) and polyol (Toyo Tire & Rubber Co., Ltd.)
Soflan R1109-50HRE (manufactured by Soflan) was injected at a ratio of 100: 78 while mixing and stirring. When foamed urethane resin began to come out from the upper air vent, the mouth was closed and injection was stopped. After leaving for about 5 minutes after injection, the molded product was released.

The molded product is formed on the outermost surface layer of the glass fiber mat with the outer surface of the thin urethane resin located on the uppermost part on both outer sides, while the separation layers 6a and 6b having a high permeation resistance are arranged at the site. The thin portions 10 and 11 (surface layer thickness of about 1 are formed with the surface layer portion pressed against the foam core of the inner layer along the surface skin).
mm) and the reinforcing layer is present at the both ends where the separation layer is not arranged, the surface layer having a high density penetrates deeply into the core, which is a foaming component. It was confirmed that a composite sandwich core molded product having a cross-sectional structure as shown in FIG. 4 was obtained.

In FIG. 4, 8 is a foam core layer in which urethane resin is foamed and hardened, and 10 and 11 are thin impregnated portions in which the separation layer / fiber reinforcement layer is pressed outward by foaming because of its high permeation resistance, and 9a. , 9b are thick-walled portions in which the high-density surface layer portion deeply penetrates into the foamed core layer 8 which is a foaming component.

[0069]

Example 4 This example is an example of producing a large disk-shaped composite sandwich foam core molded article by the method of the present invention.

A resin mold having a length of 700 mm, a width of 700 mm and a thickness of 50 mm for molding a disk having a diameter of 680 mm and a thickness of 20 mm was prepared. Next, a glass fiber continuous mat (Asahi Fiber Glass CSM-M8608-X5J) cut into a length of 700 mm and a width of 700 mm, a polyester non-woven fabric ("Unicel Lampus" P-040EK manufactured by Teijin Ltd.)
Two sets were prepared by stacking two sheets in the order of (permeation resistance was an air permeation amount per unit time, about 220 cc / cm ² / sec at room temperature), and one set was placed on the inner surface of the lower mold. Urethane foam injection machine (Shibaco CHEMIX SSU-03)
Isocyanate (C-46 manufactured by Negami Kogyo Co., Ltd.)
And polyol ("Soflan" R1 manufactured by Toyo Tire & Rubber Co., Ltd.)
109-50 HRE) was mixed and stirred at a ratio of 100: 78, and a fixed amount was poured. Before urethane resin foam cure becomes noticeable, quickly place the other non-woven fabric and glass fiber mat, stack the upper molds, close them, tighten them, and leave for about 5 minutes, then release the molded product. did.

In the molded product, thin urethane resin skins are formed on both outer sides, and the glass fiber mat is present immediately below the skin in a form pressed along the skin to the foam core of the inner layer,
It was confirmed that a molded product of the composite sandwich core was obtained. The specific gravity of this molded product was 0.2. It was confirmed that the application of this disk-shaped molding method can be applied to the manufacture of ultra-light wheels and the like.

[Brief description of drawings]

FIG. 1 is a schematic view for explaining a typical process of a molding method according to the present invention and showing a step of supplying a resin into a mold.

FIG. 2 is a schematic view for explaining a typical process of the molding method according to the present invention and showing a foaming step in a mold.

FIG. 3 is a charging cross-sectional view of an application example (Example 3) of the present invention.

FIG. 4 is a cross-sectional explanatory view of a composite molded article obtained by an application example (Example 3) of the present invention.

[Explanation of symbols]

 1a Lower mold for molding 1b Upper mold for molding 2a, 2b Fibrous reinforcing material 3a, 3b Separation layer 4 Foamable polyurethane resin (stock solution) 6a, 6b Separation layer with high permeation resistance 7a, 7b Separation layer with low permeation resistance Reinforcement material 8 Foam core layer 9a, 9b Thick impregnation layer 10, 11 Thin impregnation layer 12 Wood screw

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Claims (8)

[Claims] 1. A porous core portion formed by foaming a foamable urethane resin by reacting an isocyanate compound with a polyester or polyol having a hydroxyl group, a surface layer portion made of a urethane resin containing a fibrous reinforcing material, and A method for producing an integrated composite molded article comprising a separation layer existing between the surface layer portion and the core portion,
(A) The air permeation amount per unit time is 1 in the molding die.
A separating layer in the range of 0 to 500 cc / cm ² / second is arranged, and (b) a fibrous reinforcing material which is integrated with the separating layer or a separate inner layer between the separating layer and the inner surface of the mold in the mold. And (c) a foamable urethane resin is supplied to a region surrounded by the separation layer arranged in the mold, and (d) a foaming cure of the resin in a state where the molding mold is substantially sealed. Causing a volume expansion, which pushes the separating layer toward the inner surface of the mold, allowing some of the resin to flow through the separating layer and impregnate the fibrous reinforcing material, thus separating the separating layer and the inner surface of the mold. The foamable urethane resin is allowed to exist between the mold and the separation layer, and (e) the foamable urethane resin reaching the inner surface of the mold is cooled by the contact with the inner surface of the mold kept at a temperature lower than the resin temperature. Foaming is suppressed, solidification is completed, and the surface layer part And a core part is formed, and (f) the composite molded product thus obtained is taken out of the mold. 2. The manufacturing method according to claim 1, wherein the separation layer is a structural material integrated with the fibrous reinforcing material. 3. The method according to claim 1, wherein the fibrous reinforcing material is a woven fabric, a knitted fabric, a non-woven fabric, a unidirectionally arranged filament or a web. 4. A composition in which a foamable urethane resin is capable of foaming and volume expansion upon mixing, and substantially foams are included after foaming, and is substantially composed of an isocyanate and a hydroxyl group. The method according to claim 1, 2 or 3, wherein the polyester or the polyol is synthesized by a reaction of the polyester or the polyol. 5. The production method according to claim 1, wherein the expandable urethane resin further contains non-expandable lightweight particles. 6. The method according to claim 5, wherein the compounding ratio of the expandable urethane resin and the non-expandable lightweight particles is within the range of 10: 1 to 1: 2 by weight. 7. The production method according to claim 5, wherein the non-expandable lightweight particles are inorganic hollow particles. 8. The manufacturing method according to claim 1, wherein the form of the separation layer is a bag-shaped structure.