JP2008238491A - FRP molded body, manufacturing method thereof, and gas tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain the fiber volume content of an inner layer from being increased in an FRP molded body. <P>SOLUTION: The FRP molded body comprises a liner 10, a plurality of resin impregnated fiber layer 20 containing a fiber and thermoplastic resin formed on the outer layer of the liner, and a plurality of block layer 30 containing the fiber and an elastomer-like thermoplastic resin or the thermoplastic resin formed on the outer layer of the liner 10. The resin impregnated fiber layer 20 and the block layer 30 are alternately laminated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a molded body such as a tank or a pipe and a manufacturing method thereof, and more particularly to an FRP (fiber reinforced plastic) molded body obtained by curing a resin-impregnated fiber and a manufacturing method thereof.

  In recent years, development of high-pressure hydrogen tanks used in fuel cell systems has been progressing. In particular, in an in-vehicle fuel cell system, a gas tank made of FRP is considered promising from the viewpoint of strength and weight reduction.

  This type of high-pressure hydrogen tank is generally manufactured using a filament winding method (hereinafter referred to as “FW method”). Specifically, the resin-impregnated fiber is wound around a liner (inner container) by the FW method, and then the resin of the resin-impregnated fiber is heated and cured. Thereby, a resin-impregnated fiber layer covering the outer surface of the liner is formed, and the strength of the high-pressure hydrogen tank is ensured. This resin-impregnated fiber layer is made of, for example, CFRP (Carbon Fiber Reinforced Plastics).

  However, when an FRP molded body is produced by the FW method, there is a problem that the fiber volume content (Vf) is higher on the inner layer side than the outer layer (hereinafter also referred to as “higher Vf”). ). There are three main reasons for this. First, when the resin-impregnated fiber is wound around the liner, tension is applied to the resin-impregnated fiber. Due to the tightening effect of the tension, as the resin-impregnated fiber is wound around the liner, that is, as the lamination proceeds, the inner layer oozes out the resin so much impregnated. Secondly, when the FRP molded body is thermoset, the viscosity once decreases when the temperature of the resin becomes high, so that the resin oozes out from the resin-impregnated fiber. Third, the centrifugal force received during FW makes it easier for the resin to bleed out toward the outer layer of the liner.

  However, when the inner layer of the FRP molded body has a high Vf, the ratio of the resin in the layer relatively decreases. On the other hand, in the outer layer, Vf decreases and the proportion of the resin increases. Thus, when Vf varies, there is a possibility of affecting the characteristics such as mechanical strength of the FRP molded body.

As a related technique, Patent Document 1 discloses a method for manufacturing an FRP pressure vessel in which a reinforcing layer is provided on the outer periphery of a filled container. Patent Document 2 discloses a high-pressure tank in which a plurality of different types of layers are provided on the outer periphery of a liner, and a method for manufacturing the same.
JP-A-11-13992 JP 2005-36918 A

However, neither of these Patent Documents 1 and 2 mentions anything about controlling the fiber deposition content.
Then, in view of said problem, an object of this invention is to suppress high Vf of an inner layer in a FRP molded object.

  In order to achieve the above object, an FRP molded body according to a first aspect of the present invention includes a liner, a first layer containing fibers and a thermosetting resin, formed on an outer layer of the liner, and the first And a second layer containing fibers and an elastomeric thermosetting resin or thermoplastic resin.

  By adopting such a configuration, even if the thermosetting resin contained in the first layer is in an uncured state, the exudation of the thermosetting resin from between the fibers of the first layer is caused by the second layer. Blocked.

  In addition, the FRP molded body according to the second aspect of the present invention is formed on the liner, a plurality of first layers including fibers and thermosetting resin formed on the outer layer of the liner, and the outer layer of the liner. A plurality of second layers including fibers and an elastomeric thermosetting resin or a thermoplastic resin, wherein the first layers and the second layers are alternately laminated.

  With this configuration, even if the thermosetting resin of the first layer is in an uncured state, the exudation of the thermosetting resin from between the fibers of the first layer is blocked by the second layer. . Thereby, the fiber volume content is substantially uniform in the plurality of first layers, and the increase in Vf of the inner layer is suppressed.

  Here, the elastomeric thermosetting resin or thermoplastic resin contained in the second layer has a melting point or decomposition temperature higher than the curing temperature of the thermosetting resin contained in the first layer. As a result, even if the viscosity of the thermosetting resin decreases once when the first layer is thermoset, the exudation of such resin is blocked by the second layer.

  In the gas tank provided with the FRP molded body, for example, it is possible to suppress deterioration of characteristics such as mechanical strength.

A method for producing an FRP molded body according to one aspect of the present invention includes a step of forming a first layer by winding a fiber impregnated with an uncured thermosetting resin around an outer layer of a liner (a And a step (b) of forming a second layer by winding a prepreg containing a fiber and an elastomeric thermosetting resin or a thermoplastic resin around the outer layer of the first layer.
By setting it as this structure, the seepage of the thermosetting resin from between the fibers of the first layer is blocked by the second layer.

  Further, by repeating the steps (a) and (b) alternately, the exudation of the thermosetting resin in the first layer is blocked by the second layer formed on the upper layer. Thereby, the fiber volume content among the plurality of first layers becomes substantially uniform, and the increase in Vf of the inner layer is suppressed.

  Here, as the prepreg, by using a tape-shaped or sheet-shaped one, it is possible to continuously cover a wide range of the first layer, so that it is possible to efficiently exude the thermosetting resin. Can be suppressed. Further, for example, since the tape winding method or the sheet winding method can be used, the second layer can be easily formed.

  Here, the elastomeric thermosetting resin or thermoplastic resin contained in the prepreg may have a melting point or decomposition temperature higher than the curing temperature of the thermosetting resin contained in the first layer.

  Accordingly, after the step (b), when the first layer is thermoset, even if the viscosity of the thermosetting resin contained in the first layer is lowered, such a resin oozes out. Is blocked by the second layer.

  According to the present invention, since the resin exudation from between the fibers of the first layer is blocked by the second layer, it is possible to prevent the fibers from concentrating on the inner layer and increasing the Vf. . Accordingly, it is possible to suppress a decrease in characteristics (for example, mechanical strength) of a product such as a gas tank including the FRP molded body.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same reference number is attached | subjected to the same component and description is abbreviate | omitted.
FIG. 1 is a cross-sectional view showing the structure of an FRP molded body according to the first embodiment of the present invention. FIG. 2 is a schematic diagram showing an enlarged cross section of a portion surrounded by a one-dot chain line II shown in FIG. The FRP molded body according to the present embodiment is a main body portion (gas tank main body 1) of a gas tank filled with high-pressure gas. Such a gas tank is used, for example, as a high-pressure gas tank filled with fuel gas (for example, hydrogen gas) provided in the fuel cell system. The fuel cell system may be not only a fuel cell vehicle but also a vehicle such as an electric vehicle and a hybrid vehicle, as well as various moving bodies (for example, ships, airplanes, robots, etc.) and stationary types.

  A gas tank body 1 shown in FIG. 1 includes liners 10 and a plurality of resin-impregnated fiber layers 20 and block layers 30 that alternately cover the outer surfaces of the liners 10. The gas filled in the gas tank is supplied or discharged through an opening (not shown) formed at one end or both ends of the gas tank body 1 in the axial direction.

  The liner 10 is a part that can also be referred to as an inner shell or an inner container of the gas tank main body 1, and is formed in a hollow shape so that a storage space is defined therein. Further, the liner 10 has a gas barrier property and suppresses the permeation of the filled gas to the outside. The material of the liner 10 is not particularly limited, and examples thereof include polyethylene, polypropylene resin, and other hard resins in addition to metals.

The resin-impregnated fiber layer 20 and the block layer 30 are reinforcing layers that impart strength to the gas tank body 1.
As shown in FIG. 2, the resin-impregnated fiber layer 20 is formed by winding fibers 21 impregnated with an uncured resin (liquid or gel) 22 around the outer periphery of the inner layer (the liner 10 or the block layer 30). Is formed by.

Examples of the fibers 21 include inorganic fibers such as metal fibers, glass fibers, carbon fibers, and alumina fibers, synthetic organic fibers such as aramid fibers, and natural organic fibers such as cotton. These fibers may be used alone or in combination (as mixed fiber). In the present embodiment, carbon fibers are used as the fibers 21.
As the resin 22, for example, a thermosetting resin such as an epoxy resin, a modified epoxy resin, an unsaturated polyester resin, or the like is used. In the present embodiment, a thermosetting epoxy resin is used.

On the other hand, the block layer 30 is formed by winding a tape-shaped prepreg including the fiber 31 and the resin 32 around the outer periphery of the resin-impregnated fiber layer 20.
As the fiber 31, similarly to the fiber 21, an inorganic fiber such as a carbon fiber, or a synthetic or natural organic fiber can be used. In the present embodiment, a carbon fiber is used.

  Further, the resin 32 is an elastomeric curable resin or a thermoplastic resin, and once cured or solidified, a resin that can maintain a solid state at least in the range of normal temperature to the curing temperature of the resin 22 (that is, a resin 32) Resin having a melting point or decomposition temperature higher than the curing temperature of resin 22 is used. The reason is to maintain the impermeability of the tape-shaped prepreg to the liquid within the temperature range in the manufacturing process of the FRP molded body. Specific examples of the material used for the resin 32 include vinyl resin, PTFE (polytetrafluoroethylene), polysulfone, and polyetherimide. In this embodiment, since an epoxy resin is used as the resin 22, as a tape-shaped prepreg containing the fiber 31 and the resin 32, a heat-resistant vinyl chloride resin sheet manufactured by Sumitomo Bakelite Co., Ltd. having a heat resistance of 150 ° C. or higher, Alternatively, Sumilite (registered trademark) FS series manufactured by the same company or PTFE tape manufactured by Sumitomo 3M Limited is used.

  The outermost layer of the resin-impregnated fiber layer 20 and the block layer 30 that are alternately stacked is the block layer 30. Thus, by disposing the block layer 30 on the outside of the resin-impregnated fiber layer 20, the uncured resin 22 that tends to ooze from between the fibers 21 of the resin-impregnated fiber layer 20 is blocked.

Next, a method for forming the resin-impregnated fiber layer 20 and the block layer 30 will be described with reference to FIG. FIG. 3 is a diagram illustrating a schematic configuration of the FW device.
When forming the resin-impregnated fiber layer 20, the bobbin 11 around which the fibers 21 are wound is prepared, and an uncured resin 22 is placed in the resin tank 13. Further, the liner 10 is attached to the shaft 15. The fiber 21 fed out from the bobbin 11 is impregnated with the resin 22 in the resin tank 13 after the tension is adjusted in the pressure adjusting unit 12. The fibers 21 impregnated with the resin 22 are supplied to the rotating liner 10 via the supply unit 14 and are wound around the surface of the liner 10. In addition, it does not specifically limit about the winding method of the fiber 21, For example, the hoop winding, a helical winding, and the winding method which combined them may be sufficient.

  On the other hand, before forming the block layer 30, a bundle of fibers 31 is impregnated with an uncured resin (liquid or gel) resin 32, and the bundle is molded into a flat tape shape to form a resin 32. A prepreg is prepared in advance by curing or solidifying. When forming the block layer 30, this prepreg is set in place of the bobbin 11 in the same apparatus as shown in FIG. The resin tank 13 is removed. Then, the tension of the prepreg is adjusted by the pressure adjusting unit 12 and supplied to the rotating liner 10 via the supply unit 14, whereby the surface of the resin-impregnated fiber layer 20 is wound around the tape-shaped prepreg.

  Thus, the molded object which has a multilayer structure is produced by forming the resin impregnation fiber layer 20 and the block layer 30 by turns. Further, the molded body is heated to cure the resin-impregnated fiber layer 20, thereby completing the FRP molded body with added strength.

  Next, the FRP molded object which concerns on the 2nd Embodiment of this invention is demonstrated, referring FIG. The FRP molded body according to the present embodiment is also a main body portion (gas tank body 2) of a high-pressure gas tank provided in a fuel cell system or the like.

  As shown in FIG. 4, in the present embodiment, a block layer 40 that blocks the uncured resin 22 from leaking out from the resin-impregnated fiber layer 20 is provided only on the trunk of the gas tank body 2. In addition, about the fiber and resin material which form the block layer 40, it is the same as that in the block layer 30 shown in FIG.

As in the first embodiment, the block layer 40 may be formed using a tape-shaped prepreg, or instead using, for example, a sheet-shaped prepreg having a width comparable to that of the body portion. You may do it. In the latter case, the block layer 40 may be formed by any known method such as a sheet winding method.
According to this embodiment, the gas tank main body in which the increase in Vf at least in the body portion of the gas tank main body 2 is suppressed can be manufactured easily and in a short time.

It is sectional drawing which shows the FRP molded object which concerns on the 1st Embodiment of this invention. It is a schematic diagram which expands and shows the cross section of the part enclosed with the dashed-dotted line II shown in FIG. It is a figure which shows the schematic structure of FW apparatus. It is sectional drawing which shows the FRP molded object which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

  2 ... gas tank body, 10 ... liner, 20 ... resin impregnated fiber layer, 21, 31 ... fiber, 22, 32 ... resin, 30, 40 ... block layer

Claims (9)

With liner,
A first layer comprising fibers and a thermosetting resin formed on the outer layer of the liner;
A second layer comprising fibers and an elastomeric thermosetting resin or thermoplastic resin formed in the outer layer of the first layer;
FRP molded body comprising: With liner,
A plurality of first layers formed on an outer layer of the liner and comprising fibers and a thermosetting resin;
A plurality of second layers comprising fibers and an elastomeric thermosetting resin or thermoplastic resin formed in the outer layer of the liner;
With
An FRP molded body in which the first layer and the second layer are alternately laminated.   The elastomeric thermosetting resin or thermoplastic resin contained in the second layer has a melting point or decomposition temperature higher than the curing temperature of the thermosetting resin contained in the first layer. The FRP molded product described.   A gas tank comprising the FRP molded body according to any one of claims 1 to 3. A step of forming a first layer by winding a fiber impregnated with an uncured thermosetting resin around the outer layer of the liner;
(B) forming a second layer by wrapping a prepreg containing fibers and an elastomeric thermosetting resin or a thermoplastic resin around the outer layer of the first layer;
The manufacturing method of a FRP molded object provided with.   The manufacturing method of the FRP molded object of Claim 5 including repeating a process (a) and a process (b) alternately further.   The said prepreg is a manufacturing method of the FRP molded object of Claim 5 or 6 currently shape | molded by the tape form or the sheet form.   The elastomeric thermosetting resin or thermoplastic resin contained in the prepreg has any melting point or decomposition temperature higher than the curing temperature of the thermosetting resin contained in the first layer. The manufacturing method of the FRP molded object of 1 item | term.   The method for producing an FRP molded body according to claim 8, further comprising a step of thermosetting the first layer after the step (b).