JP2005337394A - Fiber-reinforced pressure vessel, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fiber-reinforced pressure vessel which can show an excellent reinforcement effect of a wound layer to a maximum by effectively suppressing the peeling, etc. of the layer of hardened resin-impregnated reinforcing fiber wound on a metallic liner, and has the excellent burst strength, and can suppress the scatter of the burst strength, and further to provide its manufacturing method which can suppress the drop of the production efficiency due to the generation, etc. of the scatter of the burst strength. <P>SOLUTION: The fiber-reinforced pressure vessel comprises a metallic liner, a layer of hardened resin impregnated reinforcing fiber wound on the metallic liner, and a peeling suppressing material layer including a hardening resin for suppressing the peeling of the wound layer. The peeling suppressing material layer is provided between the metallic liner and the wound layer. The hardening resin contained in the peeling suppressing material layer has an elongation of 10-200% at a maximum tensile force at 23°C, and a tensile strength of 0.1-50 MPa at 23°C. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel container for a vehicle using compressed natural gas as a fuel, a fuel container for a fuel cell, a pressure container that can be used for filling a compressed gas such as compressed air for medical use, fire fighting and leisure, The present invention relates to a fiber reinforced pressure vessel in which the strength of the vessel is reinforced with reinforcing fibers and a method for producing the same.

In recent years, composite materials of reinforcing fibers such as carbon fibers have been used in pressure vessels that require weight reduction, such as oxygen cylinders and CNG cylinders.
Such a pressure vessel is a method in which a reinforcing fiber impregnated with a thermosetting resin is wound around the surface of a liner made of a metal such as aluminum by the filament winding method (FW method), and then heated and cured, or In general, it is manufactured by a method in which a reinforcing fiber is impregnated with a thermosetting resin, wound by the FW method, and then heated and cured.
A fiber-reinforced pressure vessel manufactured by such an FW method is generally provided with a wound layer of a thermosetting resin-impregnated reinforcing fiber directly on the surface of a metal liner. As described above, in order to facilitate the recovery of the reusable resources of the pressure vessel, an anti-adhesion layer comprising a release agent coating film or a release film may be provided between the metal liner and the winding layer. Proposed.
Examples of the anti-adhesion layer include silicon-based and fluorine-based heat-resistant release agents, fluororesin heat-shrinkable films, etc., but fluororesin has an elongation at 23 ° C of about 350% at the maximum tensile load. is there.
Further, Patent Document 2 proposes that a coating containing synthetic rubber is applied to the outside of the wound layer. However, this coating is only intended to be provided on the outer layer of the container for the purpose of mitigating external impacts.
Japanese Patent Laid-Open No. 10-292899 JP 2003-521659 A

By the way, in the industrial production of the fiber reinforced pressure vessel, it is possible to produce a vessel having a sufficient reinforcing effect by the wound layer. In some cases, the burst strength decreases, or individuals with varying burst strength occur, resulting in a decrease in production efficiency due to a decrease in yield.
Therefore, when the cause of such a problem was pursued, when the winding layer was cured at the time of production, when it was cooled to room temperature, peeling occurred between the liner and the winding layer, or the reinforcing fiber itself Turned out to be hurt. Such a phenomenon is considered to occur because the thermal expansion coefficients of the metal of the liner and the reinforcing fiber are greatly different.

Therefore, the problem of the present invention is to effectively suppress the peeling between the metal liner and the wound layer of the cured resin-impregnated reinforcing fiber, and to maximize the excellent reinforcing effect inherent in the wound layer. Another object is to provide a fiber reinforced pressure vessel having an excellent burst strength and suppressing variations in the burst strength.
Another subject of the present invention is a fiber that can effectively suppress the peeling between the metal liner and the wound layer of the cured resin-impregnated reinforcing fiber, and can improve the decrease in production efficiency due to the occurrence of variations in burst strength, etc. The object is to provide a method of manufacturing a reinforced pressure vessel.

That is, according to the present invention, a metal liner, a wound layer of a reinforced resin-impregnated reinforcing fiber covering the liner, and a delamination suppressing material layer containing a cured resin for suppressing delamination of the wound layer are provided. The peeling inhibiting material layer is provided between the metal liner and the wound layer, and the cured resin contained in the peeling inhibiting material layer has a tensile maximum load elongation at 23 ° C. of 10 to 200. % And a cured resin having a tensile strength at 23 ° C. of 0.1 to 50 MPa is provided.
Further, according to the present invention, the metal liner, the thermosetting resin-impregnated reinforcing fiber, the elongation at the maximum tensile load at 23 ° C. when cured is 10 to 200%, and the tensile strength at 23 ° C. is 0. A step (A) of preparing a raw material (a) containing a thermosetting resin (X) exhibiting 1 to 50 MPa, a step (B) of forming a layer of the raw material (a) on the outer surface of a metal liner, Steps (C) and (C) for curing the layer of the raw material (a) and providing a peeling inhibitor layer, after the step (C), the entire outer surface excluding at least the base portion of the metal liner is made of a thermosetting resin-impregnated reinforcing fiber. Including the step (D) of winding coating and the step (E) of curing the thermosetting resin-impregnated reinforcing fiber wound and coated in step (D) to form a wound layer of the cured resin-impregnated reinforcing fiber. A method for producing the above-described fiber-reinforced pressure vessel is provided.
Furthermore, according to the present invention, the metal liner, the reinforcing fiber, the thermosetting resin impregnated in the reinforcing fiber, the elongation at the maximum load at 23 ° C. when cured is 10 to 200%, and 23 Preparing a raw material (a) containing a thermosetting resin (X) having a tensile strength at 0.1 ° C. of 0.1 to 50 MPa, a layer of the raw material (a) on the outer surface of a metal liner After the step (B) of forming the layer, the layer of the raw material (a) is cured, and the step (C) and the step (C) of providing the peeling inhibitor layer, the reinforcing fiber is impregnated with the thermosetting resin. Step (D ′) for winding and coating the entire outer surface of the metal liner except at least the base portion with a wet-type thermosetting resin impregnated reinforcing fiber, and the thermosetting resin wound and coated in step (D ′) Curing the impregnated reinforcing fiber and forming a wound layer of the cured resin-impregnated reinforcing fiber (E ′). Preparation of reinforced pressure vessel is provided.

The fiber-reinforced pressure vessel of the present invention includes a specific cured resin for suppressing peeling of the wound layer between the metal liner and the wound layer of the cured resin-impregnated reinforcing fiber covering the liner. Since the peeling suppressing material layer is provided, the metal liner and the wound layer of the cured resin-impregnated reinforcing fiber can be integrated, peeling of the wound layer can be effectively suppressed, and the energy absorption performance of the container can be improved. Accordingly, it is possible to maximize the excellent reinforcing effect inherent in the wound layer, to provide excellent burst strength, and to effectively suppress variations in the burst strength.
Since the production method of the present invention employs the step of providing the specific debonding suppression layer, it is possible to effectively suppress delamination between the metal liner and the wound layer of the cured resin-impregnated reinforcing fiber, and as a result, the expensive reinforcing fiber It is possible to reduce the amount of use, and there is an effect of shortening the manufacturing time by reducing the cost of the product and reducing the winding time.

The present invention will be described in detail below.
The fiber-reinforced pressure vessel of the present invention includes a metal liner, a wound layer of a reinforced resin-impregnated reinforcing fiber covering the liner, and a delamination suppressing material including a specific cured resin for suppressing delamination of the wound layer. And a layer.
Examples of the metal liner include metal liners having a cap portion, such as steel, stainless steel, aluminum or an alloy thereof, titanium or an alloy thereof.

  Examples of the reinforcing fibers constituting the wound layer include carbon fibers, glass fibers, ceramic fibers, aramid fibers, silicon carbide fibers, or fibers obtained by combining two or more of these. In particular, it is preferable to include carbon fibers that are lightweight and have excellent corrosion resistance. As the carbon fiber, it is preferable to use pitch-based carbon fiber, PAN-based carbon fiber, or a combination of these.

Examples of the thermosetting resin that is a raw material of the cured resin that constitutes the wound layer include an epoxy resin, a methyl methacrylate resin, a methacrylate resin, a polyester resin, or a mixture of two or more thereof. The well-known thermosetting resin etc. which are used for can be used.
Since the thermosetting resin used for the wound layer needs to have an adhesive action between the reinforcing fibers, the elongation at the maximum tensile load at 23 ° C. after curing is usually 6% or less, and 10% Never reach.
As the thermosetting resin-impregnated reinforcing fiber used for preparing the wound layer, a dry resin-impregnated reinforcing fiber impregnated with a thermosetting resin in advance, such as a tow prepreg, can be used. It is also possible to use fibers obtained by impregnating reinforcing fibers with the thermosetting resin.

The said peeling suppression material layer contains the specific hardening resin which can suppress peeling of the said winding layer at least. The elongation at the maximum tensile load at 23 ° C. of the cured resin is 10 to 200%, preferably 10 to 100%. When the elongation at the maximum tensile load at 23 ° C. is less than 10% or exceeds 200%, a desired peeling suppression effect cannot be obtained, and the effect of improving the burst strength of the container cannot be obtained.
Furthermore, it is particularly preferable that the elongation at 23 ° C. of the cured resin contained in the exfoliation suppressing material layer is larger than the cured resin impregnated in the reinforcing fiber in the wound layer.
Moreover, it is preferable that the tensile strength of the cured resin contained in the said peeling suppression material layer is 0.1-50 MPa in 23 degreeC, and the tensile elasticity modulus in 23 degreeC is 0.1-50 MPa.
In the present invention, the elongation at the maximum tensile load, the tensile strength and the tensile elastic modulus can be measured according to JIS K7113.
The elongation at the maximum load at 23 ° C. and the tensile strength, and further the tensile elastic modulus within the above-mentioned range prevent peeling of the winding layer and make maximum use of the reinforcing strength of the winding layer. be able to.

The cured resin contained in the exfoliation suppressing material layer further has an elongation at the maximum tensile load at 5 ° C. of 10 to 200%, more preferably 10 to 100%, and a tensile strength at 5 ° C. of 0.1 to 50 MPa. Preferably there is. Furthermore, it is preferable that the cured resin has a tensile elastic modulus at 5 ° C. of 0.1 to 50 MPa, particularly 0.5 to 10 MPa in order to further improve the desired effect. Thus, by using the cured resin that can maintain the material characteristics even at a low temperature, a good reinforcing effect can be obtained even under use conditions in the cold.
The thickness of the exfoliation suppressing material layer can be appropriately selected so as to obtain a desired effect, but is usually 100 to 2000 μm, preferably 200 to 1000 μm.

As a raw material of the cured resin mainly constituting the exfoliation suppressing material layer, it exhibits the above-mentioned specific properties when cured, for example, epoxy resin, methyl methacrylate resin, methacrylate resin, nylon resin, polycarbonate resin, polyurethane resin , A thermosetting resin (X) such as a polyethylene resin, a polypropylene resin, or a mixture of two or more thereof.
As the thermosetting resin (X), a commercially available resin can be used, and examples thereof include trade names EE50, EE50W, and EE60 manufactured by Toho Earthtech Co., Ltd.
A thermosetting resin, particularly a room temperature curable thermosetting resin is preferred because of its good workability. A two-component mixed resin is also preferable.
The thermosetting resin (X) contains a room temperature curable thermosetting resin, and the pot life at 20 ° C. is preferably 30 minutes to 5 hours, more preferably 30 minutes to 2 hours. It is desirable in terms of workability at the time. The coating film curing time at 20 ° C. is preferably 30 minutes to 12 hours, more preferably 30 minutes to 4 hours in view of the production process. The design strength expression time of the thermosetting resin (X) is usually 1 to 20 days, preferably 1 to 7 days at 20 ° C. The viscosity of the thermosetting resin (X) is usually 50 to 1,000,000 mPa · s at 20 ° C., preferably 5,000 to 300,000 mPa · s at 20 ° C. according to the JIS K6833 measurement method.

In addition to the cured resin, the release inhibitor layer is provided with a suitable viscosity range during formation of the release inhibitor layer or by preventing sagging. Various fillers and the like can be appropriately contained as long as the purpose is not impaired. By adding such a filler, the elongation at the maximum tensile load of the peeling inhibitor layer is slightly reduced, but conversely, the tensile strength and tensile elastic modulus of the peeling inhibitor layer can be improved. Therefore, it is preferable that a peeling suppression material layer consists of the said cured resin 90-100 mass% and a filler 0-10 mass%.
As fillers, carbon black, calcium carbonate, talc, silicic acid, silicate, lead white, red lead, yellow lead, titanium dioxide, strontium chromate, titanium yellow, other pigments known as inorganic pigments, fumed Mention may be made of thixotropic agents such as silica, lamellar viscous minerals, swellable mica, synthetic smectite, bentonite, carbon black, hectorite and the like.

In order to produce the fiber-reinforced pressure vessel of the present invention, for example, a metal liner, a thermosetting resin-impregnated reinforcing fiber, and an elongation at a maximum tensile load at 23 ° C. of 10 to 200% when cured, Preparing a raw material (a) containing a thermosetting resin (X) having a tensile strength at 23 ° C. of 0.1 to 50 MPa, a layer of the raw material (a) on the outer surface of a metal liner Step (B) of forming the layer of the raw material (a), the step of providing a release inhibitor layer (C), after the step (C), the entire outer surface excluding at least the base portion of the metal liner, Step (D) of winding and coating with thermosetting resin-impregnated reinforcing fiber and curing of the thermosetting resin-impregnated reinforcing fiber wound and coated in step (D) to form a winding layer of the cured resin-impregnated reinforcing fiber The first production method of the present invention including the step (E), or a metal liner, a reinforcing fiber, and impregnating the reinforcing fiber A step (A ′) of preparing a curable resin and a raw material (a) containing the thermosetting resin (X), and a step (B) of forming a layer of the raw material (a) on the outer surface of a metal liner After the steps (C) and (C) for curing the layer of the raw material (a) and providing a peeling inhibitor layer, the wet fiber obtained is obtained while impregnating the thermosetting resin into the reinforcing fibers. Step (D ′) for winding and coating the entire outer surface excluding at least the base portion of the metal liner with the resin-impregnated reinforcing fiber, and curing the thermosetting resin-impregnated reinforcing fiber wound and coated in the step (D ′), It can be obtained by the second production method of the present invention including the step (E ′) of forming a wound layer of the cured resin-impregnated reinforcing fiber.
Metal liner, thermosetting resin impregnated reinforcing fiber, raw material (a) containing thermosetting resin (X), reinforcing fiber, and heat impregnating the reinforcing fiber used in the first and second production methods of the present invention Preferred examples of the curable resin include those exemplified above. Therefore, these materials may be prepared in the step (A) and the step (A ′).

In the step (B), in order to form a layer of the raw material (a) on the outer surface of the metal liner, for example, a location where the raw material having fluidity (a) is likely to peel off at least the wound layer of the metal liner, Preferably, a method of applying to the entire outer surface excluding the base portion, a method of previously forming the raw material (a) into a film shape and the like, and affixing it to the desired location are mentioned.
When the raw material (a) is applied, dripping may be a problem. In such a case, the problem can be solved by applying the metal liner while rotating it. Moreover, application | coating can be performed by apply | coating raw material (a) uniformly with a roller brush, rubber spatula, a gold trowel, etc. so that the thickness after hardening may be 100-2000 micrometers normally, Preferably it is 200-1000 micrometers. .
When the raw material (a) is applied in the form of a film or the like, for example, heat fusion, adhesion with an adhesive, and the like can be mentioned. The adhesive is preferably of the same material system as the thermosetting resin (X).

In order to cure the layer of the raw material (a) in the step (C), for example, a method of heating to a curing temperature with a heat roll or a dryer after the step (B), or a case of including a room temperature curable thermosetting resin Can be carried out by simply leaving it at room temperature until the design strength expression time.
Also. In some cases, dripping becomes a problem during curing. In such a case, the problem can be solved by curing while rotating until the fluidity of the resin is lost.
The peeling suppression material layer obtained in the step (C) is optionally modified by physical or chemical treatment on the surface, that is, the surface in contact with the thermosetting resin-impregnated reinforcing fiber described later, by heat treatment. Adhesiveness with the curable resin-impregnated reinforcing fiber can be improved. Examples of the physical treatment include surface polishing, roughening with sandpaper, or ultrasonic treatment, and examples of chemical treatment include a method of partially oxidizing the surface and adding a functional group. It is done. Specifically, for example, surface corona treatment, plasma treatment, oxidant treatment, and the like are mentioned, and these treatments are preferably applied particularly when the thermosetting resin (X) includes a polyethylene resin, a polypropylene resin, or the like. can do.

The step (D) is based on a so-called dry winding method in which a thermosetting resin-impregnated reinforcing fiber such as tow prepreg is wound around the desired outer surface of the metal liner including the peeling inhibitor layer formed in the step (C) by the FW method. It is a process and can be carried out by appropriately setting conditions by a known method or the like.
On the other hand, the process (D ′) is a process by a so-called wet winding method in which the reinforcing fiber is impregnated with a fluid thermosetting resin and the resulting wet thermosetting resin-impregnated reinforcing fiber is wound by the FW method. Yes, it can be carried out by appropriately setting conditions by a known method or the like.

In the steps (E) and (E ′), the curing of the thermosetting resin-impregnated reinforcing fiber is a method of heating to a curing temperature in an autoclave, a heating furnace, or the like, or when a room temperature curable thermosetting resin is included. It can be carried out by, for example, a method of leaving it at room temperature until the design strength expression time.
When the resin moves due to gravity and is biased during the curing, the curing can be performed while rotating until the curing is completed.
In the production method of the present invention, within the range that does not impair the desired effect of the present invention, and for the purpose of adding other effects, or between the metal liner and the delamination suppressing material layer, or the delamination suppressing material layer and the cured resin. Another layer may be provided between the wound layer of the impregnated reinforcing fibers.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.
Example 1
As a specimen, an aluminum liner (length: 345 mm, outer diameter: 100 mm, inner volume: 2.1 liter, material A6061-T6) manufactured by SAMTECH was used. In order to prevent dripping, while rotating this specimen, epoxy-based thermosetting resin (epoxy resin, trade name Toho Dite EE50 (manufactured by Toho Earth Tech Co., Ltd.)) and curing is applied to the entire outer surface except the base. 5. Tensile elongation at 23 ° C. at 95 ° C. (measured according to JIS K7113), tensile strength 1.4 N / mm ² (measured according to JIS K7113) 65% elongation at maximum tensile load at 5 ° C., tensile strength 6. 5N / mm ² ) was applied so that the thickness of the peel-off suppressing material layer after curing was 200 μm and cured at room temperature for 24 hours to form a peel-inhibiting material layer.
After curing, a tow prepreg (carbon fiber: M30S-18K manufactured by Toray Industries, Inc., resin: 130 ° C. curable epoxy resin) manufactured by Nippon Oil Corporation was wound using a filament winding apparatus (inner layer: helical winding, 1.1 mm). Thickness + outer layer: hoop winding, 1.6 mm).
After completion of the winding, while rotating the specimen, curing was performed in a curing furnace at 130 ° C. for 2 hours to form a wound layer of the cured resin-impregnated reinforcing fiber, and a fiber-reinforced pressure cylinder was produced.
After the obtained cylinder is gradually cooled to room temperature, the three cross-type strain gauges shown in FIG. 1 of the cylinder are attached as No. 1 to No. 3, and the distortion in each of the circumferential direction and the longitudinal direction is applied. It was measured. A typical stress strain graph is shown in FIG. From FIG. 2, it can be seen that uniform distortion occurs at each measurement point.
Moreover, the burst test by water pressure was implemented according to KHK S1121 (2000), and the burst strength was measured. The presence or absence of peeling noise during cooling was also observed. The results for 7 samples are shown in Table 1.

Example 2
A bomb was produced in the same manner as in Example 1 except that the thickness of the peeling suppression layer buffer material layer was 500 μm, and a burst test was performed. The results are shown in Table 1.

Comparative Example 1
A cylinder was prepared and a burst test was performed in the same manner as in Example 1 except that the wound layer of the cured resin-impregnated reinforcing fiber was directly formed on the specimen without forming the peeling inhibitor layer. The results are shown in Table 1. Further, distortion was measured in the same manner as in Example 1. A typical stress strain graph is shown in FIG. As can be seen from FIG. 3, the strain varies from place to place, and this is considered to be a cause of low burst pressure and large variation.

It is the schematic which shows the sticking location of the strain gauge of the strain measurement performed in Example 1 and Comparative Example 1. FIG. 2 is a graph showing typical stress strain measured in Example 1. FIG. 5 is a graph showing typical stress strain measured in Comparative Example 1.

Claims (6)

A metal liner, a wound layer of a reinforced resin-impregnated reinforcing fiber covering the liner, and a release inhibitor material layer containing a cured resin for suppressing peeling of the wound layer,
The peeling inhibiting material layer is provided between the metal liner and the wound layer, and the cured resin contained in the peeling inhibiting material layer has an elongation at a maximum tensile load at 23 ° C. of 10 to 200%. And a cured resin having a tensile strength at 23 ° C. of 0.1 to 50 MPa.   The said peeling suppression material layer contains the said cured resin 90-100 mass% and the filler 0-10 mass%, and the tensile elasticity modulus in 23 degreeC is 0.1-50 Mpa, It is characterized by the above-mentioned. The fiber-reinforced pressure vessel as described.   The cured resin contained in the exfoliation suppressing material layer is a cured resin having an elongation at a maximum tensile load at 5 ° C. of 10 to 200% and a tensile strength at 5 ° C. of 0.1 to 50 MPa, and the exfoliation The fiber-reinforced pressure vessel according to claim 1 or 2, wherein the inhibitor layer has a tensile elastic modulus at 5 ° C of 0.1 to 50 MPa.   The average thickness of the said peeling suppression material layer is 100-2000 micrometers, The fiber reinforced pressure vessel of any one of Claims 1-3 characterized by the above-mentioned. Metal liner, thermosetting resin-impregnated reinforcing fiber, heat at which the elongation at 23 ° C. when cured is 10 to 200% and the tensile strength at 23 ° C. is 0.1 to 50 MPa. Preparing a raw material (a) containing a curable resin (X) (A),
Forming a layer of the raw material (a) on the outer surface of the metal liner (B),
Step (C) of curing the layer of the raw material (a) and providing a peeling inhibitor layer,
After step (C), the entire outer surface excluding at least the base portion of the metal liner is wound and coated with a thermosetting resin-impregnated reinforcing fiber (D), and
2. The fiber reinforcement according to claim 1, comprising a step (E) of curing the thermosetting resin-impregnated reinforcing fiber wound and coated in step (D) to form a wound layer of the cured resin-impregnated reinforcing fiber. Manufacturing method for pressure vessels. Metal liner, reinforcing fiber, thermosetting resin impregnated in the reinforcing fiber, elongation at 23 ° C. under tensile maximum load when cured is 10 to 200%, and tensile strength at 23 ° C. is 0 A step (A ′) of preparing a raw material (a) containing a thermosetting resin (X) exhibiting 1 to 50 MPa,
Forming a layer of the raw material (a) on the outer surface of the metal liner (B),
Step (C) of curing the layer of the raw material (a) and providing a peeling inhibitor layer,
After step (C), while impregnating the reinforcing fiber with the thermosetting resin, the entire outer surface excluding the base part of the metal liner is wound and covered with the obtained wet thermosetting resin-impregnated reinforcing fiber. (D ') and
The method further comprises a step (E ′) of thermosetting the thermosetting resin-impregnated reinforcing fiber wound and coated in the step (D ′) to form a wound layer of the cured resin-impregnated reinforcing fiber. The manufacturing method of the fiber reinforced pressure vessel of description.

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