JPH08224822A - Fiber reinforced resin composite molding and manufacture thereof - Google Patents

Abstract

PURPOSE: To obtain a molding having excellent sound absorbing and heat insulating properties by providing a mixture of a thermoplastic resin fiber and a reinforced fiber and a substrate material, and forming on the substrate material, a flocculent mixture non-solidified layer whose thermoplastic resin fiber is unmelted and unsolidified through a mixture solidified layer wherein a thermoplastic resin is melted and solidified. CONSTITUTION: When a composite molding is to be manufactured, a flocculent mixture C arranged in between a heating member 2 and a heat depriving member 3 is heated from the heating member 2. At this time, a substrate material 1 is arranged between the heating member 2 and the flocculent mixture C and heated to a melt temperature or higher of a thermoplastic resin fiber in the flocculent mixture C. On the other hand, the temperature of the member 3 is kept in a melt temperature or lower of the thermoplastic resin fiber so as to avoid heat melt at the member 3. Thus, a flocculent mixture non-solidified layer B having a melted and solidified thermoplastic resin on one face of the substrate material 1 whose thermoplastic resin fiber does not melt nor solidify through a mixture solidified layer A for heightening structural strength as a whole, and containing cavities among the fibers for providing sound absorbing and vibration absorbing functions is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a composite of a fibrous thermoplastic resin and a reinforcing fiber and a substrate material such as metal such as aluminum foil, which is used for sound absorption performance, heat insulation performance, vibration damping performance, etc. The present invention relates to a fiber-reinforced resin composite molded body having the following, and a manufacturing method thereof. The composite molded body is a member that is required to have sound insulation and sound absorption performance for engine sound, such as an undershield material and a noise shield material used in automobiles and the like. Etc. can be effectively utilized.

[0002]

2. Description of the Related Art For example, as an under shield material for absorbing sound which is attached to a lower portion of a vehicle body of an automobile or the like,
The one in which a glass fiber mat is wrapped in aluminum foil or the like or a sound absorbing member made of a porous body is bonded to one surface of a metal base material such as a steel plate with an adhesive or the like is used.

On the other hand, fiber-reinforced thermoplastic resin-based composite materials are inexpensive and have excellent mechanical properties, and also have excellent recyclability. Is widely used in. A typical material structure of this type of composite material is one in which glass fiber or carbon fiber is used as a reinforcing fiber, and a polyolefin resin such as polypropylene is compounded as a thermoplastic resin. There is also a tendency to effectively use the thermoplastic resin-based composite material as the above-mentioned under shield material, noise shield material, or the like.

However, the ordinary fiber-reinforced thermoplastic resin-based composite material has the advantages that it is inexpensive, does not cause rust, and is excellent in recyclability.
It does not have the essential sound absorption performance. Therefore, when using this composite material as a material such as an undershield material,
It can only be expected to function as a substrate material,
A sound absorbing member such as a glass fiber mat wrapped with aluminum foil or the like similar to the above must be attached to the surface thereof.

In any case, the conventional sound absorbing material is prepared by separately preparing a base material for ensuring structural strength and a glass fiber mat or a porous body for providing sound absorbing performance, etc. and bonding them together. It has been pointed out that the manufacturing cost is high and the product cost is high as a result. On the other hand, a heat insulating material having a structure in which a synthetic resin film, an aluminum foil or the like is bonded to the upper and lower surfaces of a glass fiber mat is known, and it is considered that such a bonding material can be used as a sound absorbing material, etc. Since the structural strength of the molded body as a whole is insufficient, it cannot be put to practical use as the above-mentioned undershield material for automobiles unless a metal plate or the like is combined as the support layer.

[0006]

SUMMARY OF THE INVENTION The present invention has been made by paying attention to the above circumstances, and its purpose is to have excellent sound absorbing characteristics, heat insulating characteristics, vibration suppressing effect and the like and to have an excellent structure. It is an object of the present invention to provide a fiber-reinforced resin composite molded body having strength and capable of being manufactured by a relatively simple method. Another object of the present invention is to provide such a fiber-reinforced resin composite molded body. It is intended to provide a method that can be manufactured with high productivity.

[0007]

The structure of the fiber-reinforced resin composite molded article according to the present invention, which has been able to solve the above-mentioned problems, comprises a mixture of thermoplastic resin fibers and reinforcing fibers and a substrate material. Where a cotton-like mixture non-solidified layer (B) in which the thermoplastic resin fibers are not melt-solidified is formed on a plate material via a mixture solidified layer (A) in which the thermoplastic resin is melt-solidified It has the gist.

Further, in the constitution of the manufacturing method according to the present invention, the cotton-like mixture containing the thermoplastic resin fiber and the reinforcing fiber is heated only from the heating member side between the heating member and the heat absorbing member. A substrate material is arranged between the member and the cotton-like mixture, the heating member is heated to a temperature above the melting temperature of the thermoplastic resin fiber, and the heat-absorption member is maintained below the melting temperature of the thermoplastic resin fiber, The cotton-like mixture is heated from the heating member side and the thermoplastic resin fibers in the mixture are heated and melted on the substrate material side by heat removal to the heat removal member side, but not on the heat removal member side. As a result, a composite molded body including a substrate material, a mixture solidified layer (A) having a melted and solidified thermoplastic resin, and a non-melted cotton-like mixture non-solidified layer (B) of thermoplastic resin fibers is obtained. Where it has a gist There.

[0009]

As described above, the fiber-reinforced resin composite molded article of the present invention comprises a mixture of thermoplastic resin fibers and reinforcing fibers and a substrate material made of aluminum foil or the like. For example, as shown in FIG. 1, the thermoplastic resin fibers are not melted and solidified through the mixture solidified layer (A) which has the melted and solidified thermoplastic resin and enhances the structural strength as a whole, and the voids between the fibers are included to absorb the sound. , A cotton-like mixture non-solidifying layer (B) that exhibits functions such as heat insulation and vibration absorption is formed,
Such a fiber-reinforced resin composite molded body can be easily manufactured as an integrated body by the method described in detail below.

The features of the obtained fiber-reinforced resin composite molded article will be described below in detail while explaining the production method according to the present invention.
FIG. 2 is a schematic process explanatory view illustrating the method of the present invention,
As the raw material, a substrate material 1 made of a metal material such as aluminum foil, and a cotton-like mixture C containing thermoplastic resin fibers and reinforcing fibers are used. In producing the composite molded body, the cotton-like mixture C is heated only between the heating member 2 and the heat absorbing member 3 from the side of the heating member 2. At this time, the heating member 2 and the cotton-like mixture C are heated. A substrate material 1 such as aluminum foil is placed between the heating members 2 and the heating member 2 is heated to a temperature higher than the melting temperature of the thermoplastic resin fibers in the cotton-like mixture, while the heat removal member 3 is connected to the thermoplastic resin fibers. Of the cotton-like mixture C from the heating member 2 side and the heat-absorption member 3
The heat absorbing member 3 heats and melts the thermoplastic resin fibers in the cotton-like mixture C on the side of the substrate material 1 by heat absorption to the side.
On the side, pressure molding is carried out at an appropriate pressure so as not to heat and melt.

Then, as shown in FIG. 2B, on the heating member 2 side of the cotton-like mixture C in contact with the substrate material 1, the thermoplastic resin fibers in the cotton-like mixture C are melted to form the substrate material 1. It is cast on the interface of the
When this is cooled, the mixture solidified layer (A) in which the thermoplastic resin fills the inter-fiber voids and is melted and solidified is formed in a state of being strongly bonded to the substrate material 1. On the other hand, the heat-absorptive member 3 side is at a temperature lower than the melting temperature of the thermoplastic resin fiber, so that the thermoplastic resin fiber in the cotton-like mixture C is not melted and the cotton-like mixture is not solidified while leaving the interfiber void. It is left as layer (B).

Therefore, the heating temperature and heating time of the heating member 2, the temperature of the heat absorbing member 3 and the like can be appropriately controlled according to the desired thickness of the solidified layer (A) of the mixture and the non-solidified layer (B) of the cotton-like mixture. For example, the solidified mixture layer (A) having a thickness having a required structural strength is formed on the substrate material 1 in a state of being strongly bonded to the substrate material 1 and has voids between the fibers to absorb sound, insulate heat, or reduce vibration. A fiber-reinforced resin composite molded body in which the cotton-like mixture non-solidified layer (B) having various functions is integrally bonded is obtained.

At this time, at the boundary between the solidified mixture layer (A) and the non-solidified cotton-like mixture layer (B), the reinforcing fibers in the non-solidified cotton-like mixture layer (B) are reinforced in the solidified mixture layer (A). Not only is it embedded with the fibers,
Since the thermoplastic resin fibers are also embedded in the mixture solidified layer (A), the mixture solidified layer (A) and the cotton-like mixture non-solidified layer (B) are eventually reinforced by the reinforcing fiber thermoplastic resin fibers. As a result, the fiber-reinforced resin composite molded body in which the substrate material 1, the mixture solidified layer (A) and the cotton-like mixture non-solidified layer (B) are integrated is obtained.

The heating and pressurizing conditions at this time vary depending on the type of the thermoplastic resin (particularly the melting temperature) and the target thickness of the solidified mixture layer (A), and therefore cannot be uniformly determined. The preferred heating temperature when using the most common polypropylene resin as the thermoplastic resin is 180 to 250 ° C., more preferably 200 to 230.
The shaping pressure is in the range of 5 to 400 kg / cm ² , and more generally 50 to 200 kg / cm ² . In the above description, an example in which a heating plate is used as the heating means has been shown, but in addition to this, infrared heating, high-temperature gas spray heating, or the like can also be adopted.

In the heat and pressure molding using the heating member 2 and the heat absorbing member 3, the thermoplastic resin fibers are heated and melted by the heating member 2 and then the heating member 2 is cooled by water cooling or the like to be cooled and solidified. However, since heat loss due to heating / cooling of the heating member 2 cannot be neglected in this method, it is preferable that the thermoplastic resin fiber on the substrate material 1 side is melted by heating by the heating member 2 and then cooled. -It is preferable to adopt a method of transferring to a shaping mold and shaping while cooling and solidifying. In this case, since the laminated material before being cooled and solidified is soft and easily deformed, it is transferred to the cooling / shaping dies 4a, 4b according to the shape of the final molded article as shown in FIG. By adjusting the above, it is possible to obtain a molded product having an arbitrary shape as well as a plate shape.
The substrate material 1 interposed between the cotton-like mixture C which is a forming raw material and the heating member 2 has a function as a release material that prevents the semi-finished product in an unsolidified state from adhering to the heating surface of the heating member 2. At the same time, it also functions as a support material when transferring from the heating member 2 to the cooling / shaping mold.

The fiber-reinforced resin composite molded body thus obtained has a thermoplastic resin having interfiber voids of reinforcing fibers on the surface of the substrate material 1 as shown in FIG. 1 and as is clear from the above description. Rigid mixture solidified layer (A) cooled and solidified in the state of being filled with the melt, and a cotton-like mixture with sound absorbing, heat insulating and vibration suppressing functions leaving the interfiber voids of the reinforcing fibers and the thermoplastic resin fibers as they are. It has a structure in which the solidified layer (B) is joined and integrated.

Next, the raw material for the fiber-reinforced resin composite molded body will be described. First, the main action expected of the substrate material 1 is to prevent the thermoplastic resin that has been heated and melted as described above from joining to the heating surface of the heating member 2. Since it is not expected that the substrate material 1 itself has a function of enhancing the structural strength, use of thin metal foil such as aluminum foil or heat resistant resin film You can In particular, as shown in FIG. 2 (C), when final shaping is performed with a mold for cooling and solidifying / shaping, by selecting and using such a thin substrate material 1, it is possible to perform any shaping without any trouble. It is preferable because it can be shaped. Further, it is preferable to use a metal foil as the substrate material 1 because, for example, the designability when it is provided as an under shield material for automobiles as a final product and the like, and the commercial value can be increased. In this substrate material 1,
It is also effective to carry out a surface treatment for enhancing the bonding strength with the mixture solidified layer (A), for example, a resin coating or the like, if necessary.

Next, as the thermoplastic resin fiber used as the raw material of the cotton-like mixture, in addition to the above-mentioned polypropylene resin, other polyolefin resin such as polyethylene, AB
S resins, polyester resins such as polyethylene terephthalate, polyamide resins such as nylon, polycarbonate resins, polystyrene resins, polyacetal resins, polyacrylate resins, and other general-purpose resins, as well as polysulfones, polyphenylene sulfides, polyether ether ketones. It is also possible to use a thermoplastic resin having excellent heat resistance such as polyimide, polyamide-imide, or the like. Among these, polypropylene resin is particularly preferable in view of cost, performance and the like. As the polypropylene-based resin, not only polypropylene homopolymer but also polypropylene-ethylene block copolymer, polypropylene-ethylene random copolymer, maleic anhydride-modified polypropylene-based resin and the like can be used, and these thermoplastic resins are used. The resins may be used alone or in combination of two or more.

Examples of preferable reinforcing fibers include artificial fibers such as glass fibers, carbon fibers, metal fibers, ceramic fibers, aramid fibers, polyamide fibers, polyester fibers and acrylic fibers, but also hemp and cotton. Natural fibers, and further cellulosic fibers obtained by defibrating used paper can be used, but the most common of these are glass fibers and carbon fibers. Further, it is advantageous to use cellulosic fibers obtained by defibrating waste paper from both aspects of recycling and environmental protection, but since these natural fibers have a tendency to lack rigidity, they have high rigidity as described above. It is desirable to use artificial fibers as the main reinforcing fibers, and to mix them with natural fibers within a range that does not impair the porosity and strength characteristics.

As a method for mixing the above-mentioned thermoplastic resin and reinforcing fibers, an air flow mixing method using a compressed gas such as compressed air is adopted, and the reinforcing fibers and the thermoplastic resin fibers are mixed together while being defibrated. Is preferred. The preferred size and size of the reinforcing fibers when the airflow mixing method is adopted are the structural strength as the mixture solidified layer (A) and the cotton-like mixture non-solidified layer (B).
In consideration of sound absorption, heat insulation, vibration suppressing function, etc., the fiber diameter is 1 to 100 μm, more preferably about 3 to 20 μm, and the fiber length is 1 to 100 mm, more preferably 5 to 50 m.
About m, the preferred fiber system and fiber length of the thermoplastic resin fiber are in the range of about the same as the reinforcing fiber.

When a powdery thermoplastic resin is used, the thermoplastic resin in the non-solidified layer (B) of the cotton-like mixture is not melted in the molding step, as described above, and the powdery thermoplastic resin is It is not preferable because only the fibers of the reinforcing fibers are mixed in the space between the fibers, and the powdery granular thermoplastic resin may fall off due to vibration during handling or transportation.

The mixing ratio of these thermoplastic resin fibers and reinforcing fibers constituting the cotton-like mixture is not particularly limited, and may be determined each time in consideration of the required structural strength, sound absorption, heat insulation and vibration damping performance. The thermoplastic resin fiber: reinforcing fiber weight ratio can be selected from a wide range of 10 to 90%: 90 to 10%, but a more general range is 30 to 70%: 70 to
It is in the range of 30%.

If the above-mentioned air flow mixing method is adopted, regardless of the dimensional size and the compounding ratio of the reinforcing fibers and the thermoplastic resin fibers,
In any case, both can be efficiently and uniformly mixed, which is preferable.

The thickness of the mixture solidified layer (A) and the cotton-like mixture non-solidified layer (B) should be set according to the required structural strength of the composite molded article and the degree of sound absorption, heat insulation, and impact relaxation performance. Although it cannot be uniformly determined, if it is shown as a standard standard, the thickness of the mixture solidified layer (A) as the support reinforcing layer is about 2 to 4 mm, and the cotton-like mixture non-solidified as the functional layer for sound absorption or the like. The thickness of the layer (B) is generally in the range of 5 to 10 mm.

[0025]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the following examples do not limit the present invention, and all modifications and changes within the scope of the present invention will be made without departing from the gist of the preceding and the following. It is included in the technical scope.

Example 1 Chopped glass fibers having a fiber diameter of 13 μm and a fiber length of 13 mm (Asahi Fiber Glass Co., Ltd., trade name “FT599”)
40 parts by weight and 60 parts by weight of polypropylene resin resin having a denier of 3 mm and a fiber length of 13 mm (manufactured by Daiwa Spinning Co., Ltd.) were uniformly mixed while being defibrated by an air flow mixing method using compressed air to obtain a cotton-like mixture. Obtained.

An aluminum foil is placed on a heating plate heated to 200 ° C., the cotton-like mixture is superposed on the aluminum foil, and a metal plate whose surface temperature is kept at 50 ° C. is pressed against the aluminum foil, and the surface pressure is 50 kgf / cm. by holding pressurized while 2 minutes at ^2, to melt the propylene-based resin of the aluminum foil side of the heating platen in cotton-like mixture.

Next, this semi-finished product is manufactured with 50
Transferred to a shaping mold set to ℃, surface pressure 100kgf / c
by cooling with pressurized with m ² shaping, and aluminum foil, and the solid phase portion 3mm states propylene resin fiber satisfies the fiber interstices of the glass fibers were melted and solidified, the propylene resin and glass fibers are uniformly A fiber-reinforced resin composite molded body having a three-layer composite structure composed of a cotton-like portion 8 mm in which inter-fiber voids were left as it was mixed was obtained. In the composite molded body, the aluminum foil and the solid phase portion are firmly bonded by the propylene resin melted and solidified, and the solid phase portion and the cotton-like portion are bonded by the glass fiber existing across the interface between both portions. The three layers were firmly integrated.

A test piece having a diameter of 88 mm was cut out from this composite molded body, and its sound absorption property was measured to be 1500 Hz.
The sound absorption coefficient at 0.5 was confirmed to have excellent sound absorption characteristics.

Example 2 30 parts by weight of the same chopped glass fiber used in Example 1 and 70 parts by weight of the same polypropylene resin fiber (manufactured by Daiwa Spinning Co., Ltd.) used in Example 1 were compressed air. The mixture was uniformly mixed while being defibrated by an air flow mixing method using to obtain a cotton-like mixture.

An aluminum foil is placed on the lower plate of the press heated to 200 ° C., and the above cotton-like mixture is superposed on the aluminum foil.
On top of that, press the upper plate of the press whose surface temperature is kept at 50 ° C. and press for 3 minutes while pressing it with a surface pressure of 55 kgf / cm ² to obtain a propylene-based propylene-based product on the aluminum foil side on the upper plate of the press in the cotton-like mixture. The resin was melted.

Next, this semi-finished product is transferred into a shaping mold kept at 50 ° C. and cooled and shaped while being pressurized with a surface pressure of 80 kgf / cm ² , and the aluminum foil and the propylene resin fiber are melted and solidified. A fiber having a three-layer composite structure consisting of a solid phase portion 4 mm in which the fiber gap of the glass fiber is filled and a cotton-like portion 6 mm in which the inter-fiber void is left while the propylene resin fiber and the glass fiber are uniformly mixed. A reinforced resin composite molded body was obtained.
In the composite molded body, the aluminum foil and the solid phase portion are firmly bonded by the propylene resin melted and solidified,
The solid phase portion and the cotton-like portion were bonded by the glass fiber existing across the interface between both portions, and the three layers were firmly integrated.

A test piece having a diameter of 88 mm was cut out from this composite molded body, and its sound absorption property was measured to be 1500 Hz.
The sound absorption coefficient at 0.4 was confirmed to have excellent sound absorption characteristics.

[0034]

As described above, the fiber-reinforced resin composite molded article of the present invention comprises the substrate material, the mixture solidified layer (A) which becomes the support reinforcing layer, and the cotton which becomes the functional layer for sound absorption, heat insulation, vibration prevention and the like. The mixture-like non-solidified layer (B) is joined and integrated,
It can be effectively used as it is as a sound absorbing member, a heat insulating member, a shock absorbing member, etc. without requiring reinforcement of structural strength by a base material or the like. According to the method of the present invention, it is possible to efficiently manufacture a composite molded body having excellent structural strength and various functions such as sound absorption as described above by a simple procedure.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view illustrating the structure of a fiber-reinforced resin composite molded body according to the present invention.

FIG. 2 is a schematic sectional process explanatory view illustrating the manufacturing method according to the present invention.

[Explanation of symbols]

 A mixture solidified layer (A) B cotton-like mixture non-solidified layer (B) C cotton-like mixture 1 substrate material 2 heating member 3 heat removal member 4a, 4b cooling / shaping type

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiaki Okumura 1-5-5 Takatsukadai, Nishi-ku, Kobe-shi, Hyogo Kobe Steel Works, Ltd. Kobe Research Institute

Claims (2)

[Claims] 1. A mixture of a thermoplastic resin fiber and a reinforcing fiber and a substrate material, wherein the thermoplastic resin is melted and solidified on the substrate material through a mixture solidification layer (A). A fiber-reinforced resin composite molded article, comprising a cotton-like mixture non-solidified layer (B) in which resin fibers are not melted and solidified. 2. A cotton-like mixture containing a thermoplastic resin fiber and a reinforcing fiber is heated only between the heating member and the heat absorbing member from the side of the heating member, and at this time, between the heating member and the cotton-like mixture. A substrate material is placed on the heating member, the heating member is heated to a temperature above the melting temperature of the thermoplastic resin, the heat absorbing member is kept below the melting temperature of the thermoplastic resin, and the cotton-like mixture is fed from the heating member side. Heating and melting of the thermoplastic resin in the mixture on the side of the substrate material by heat removal to the side of the heat absorbing member, while not melting on the side of the heat absorbing member, the substrate material and the heat solidified A fiber-reinforced resin composite molded article, characterized by obtaining a composite molded article comprising a mixture solidified layer (A) having a plastic resin and a cotton-like mixture non-solidified layer (B) of a thermoplastic resin which is not melt-solidified. Manufacturing method.