JP2013193393A - Method and apparatus for manufacturing high pressure gas tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove bubbles formed in a surface layer of a fiber-reinforced resin layer of a high pressure gas tank using a defoaming agent with no problem of strength degradation, stripping, or the like of the formed fiber-reinforced resin layer.SOLUTION: A tank container having, on the outer surface, a fiber layer formed by winding reinforced fiber impregnated with thermosetting resin containing a main agent and a curing agent, is heated to carry out thermosetting treatment of thermosetting the thermosetting resin to form a fiber-reinforced resin layer and at the same time to remove bubbles formed in the thermosetting resin by breaking the bubbles with a defoaming agent in a defoaming agent solution applied to the outer surface of the fiber layer. The defoaming agent solution is obtained by mixing the defoaming agent with a solvent that contains the same component as the main agent of the thermosetting resin.

Description

  The present invention relates to a high-pressure gas tank.

  The high-pressure gas tank may be mounted on a moving body such as a fuel cell vehicle, and the weight reduction is required. As a method for reducing the weight of a high-pressure gas tank, a manufacturing method of a high-pressure gas tank by a filament winding method (hereinafter also referred to as “FW method”) is known. In the manufacturing method of a high-pressure gas tank by the FW method, a reinforcing fiber impregnated with a thermosetting resin typified by an epoxy resin is wound around the outer periphery of a resin tank container also called a liner, and the thermosetting property in the reinforcing fiber is wound. A fiber reinforced resin layer is formed by thermosetting the resin.

  By the way, in the FW method, in the process of thermosetting the thermosetting resin, air or the like that has entered inside the thermosetting resin or between the reinforcing fibers gradually moves to the outside, and the formed fiber reinforced resin layer There was a problem that irregularities due to bubbles occurred on the surface layer. When irregularities due to bubbles are generated on the surface layer of the high-pressure gas tank, an error occurs in the dimensions of the high-pressure gas tank and the assembling property of the high-pressure gas tank is lowered. In addition, the surface strength of the high-pressure gas tank may be reduced. Furthermore, such irregularities on the surface layer cause a decrease in the design of the high-pressure gas tank.

  So far, there is a technology (Patent Document 1) for physically removing bubbles generated in the thermosetting process of the FW method by a bubble removing unit (Patent Document 1) and a technology for removing by irradiating ultrasonic waves (Patent Document 2). ,Proposed.

JP 2010-125826 A JP 2010-125825 A

  As a technique different from the conventional technique for removing bubbles, a technique for removing bubbles on the surface layer generated in the thermosetting process of the FW method using a general antifoaming agent may be considered. This is because the antifoaming agent solution in which the antifoaming agent is dissolved in a solvent is applied to the surface layer of the fiber reinforced resin layer during the thermosetting process, and the defoaming agent comes into contact with the generated bubbles to break the bubbles. Thus, bubbles generated in the surface layer of the fiber reinforced resin layer are removed.

  As an antifoaming agent for thermosetting resins (also called “defoaming agent”), a foam-breaking polymer is generally used, and as a solvent thereof, an organic solvent such as toluene, methyl elketone (MEK), or naphtha is used. Is used. Since these organic solvents chemically react with the main component (also called “main agent”) constituting the thermosetting resin, the thermosetting resin cannot be cured normally, and the strength of the portion is reduced or peeled off. Could cause problems.

  It is an object of the present invention to provide a technique for removing bubbles generated in the surface layer of a fiber reinforced resin layer of a high-pressure gas tank using a defoaming agent without problems such as a decrease in strength and peeling of the formed fiber reinforced resin layer. And

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
A method for producing a high-pressure gas tank, wherein the thermosetting is performed by heating a tank container having a fiber layer formed on an outer surface by wrapping a reinforcing fiber impregnated with a thermosetting resin containing a main agent and a curing agent. While performing a thermosetting treatment in which a resin is thermoset to form a fiber reinforced resin layer, bubbles generated in the thermosetting resin are removed from the defoamer solution applied to the outer surface of the fiber layer. It comprises a step of removing by defoaming with a foaming agent, wherein the antifoaming agent solution is a mixture of the antifoaming agent and the same component solvent as the main component of the thermosetting resin. Manufacturing method.
According to this manufacturing method, during the heating of the tank container for thermosetting the thermosetting resin, the bubbles generated in the thermosetting resin can be effectively removed by defoaming with an antifoaming agent. Can do. In addition, since the solvent of the antifoaming agent is the same component as the main component of the thermosetting resin, the thermosetting resin cannot be cured as in the conventional case, and the strength reduction or peeling of the formed fiber reinforced resin layer, etc. The occurrence of this problem can be suppressed.

[Application Example 2]
The manufacturing method according to Application Example 1, wherein the thermosetting resin impregnated in the reinforcing fiber forming the outer surface portion to which the antifoaming agent solution is applied forms the other portion of the fiber layer. A manufacturing method characterized by having a composition ratio of an excessive curing agent in which the ratio of the curing agent is increased as compared with the composition ratio of the main component and the curing agent of the thermosetting resin impregnated in the reinforcing fiber.
According to this manufacturing method, it becomes possible to harden the antifoamer solution apply | coated to the outer surface of a fiber layer, and the strength fall by the apply | coated antifoamer solution can be suppressed.

[Application Example 3]
It is a manufacturing method of the application example 1 or the application example 2, Comprising: Application | coating to the outer surface of the said fiber layer of the said antifoamer solution is performed during execution of the said thermosetting process.
According to this manufacturing method, it becomes easy to apply the antifoaming agent uniformly to the outer surface of the fiber layer, and the generated bubbles can be effectively broken to be removed.

[Application Example 4]
An apparatus for manufacturing a high-pressure gas tank, wherein a tank container having a fiber layer formed by wrapping a reinforcing fiber impregnated with a thermosetting resin containing a main agent and a curing agent is heated on the outer surface, the thermosetting A thermosetting treatment part for thermosetting resin to form a fiber reinforced resin layer, and when the thermosetting treatment is heating the tank container, occurs on the outer surface of the fiber layer during the formation of the reinforcing fibers. An antifoaming agent application part for applying an antifoaming agent solution containing an antifoaming agent for breaking bubbles to be generated, the antifoaming agent solution being the main agent of the antifoaming agent and the thermosetting resin. A manufacturing apparatus characterized by being mixed with a solvent of the same component.
According to this manufacturing apparatus, during the heating of the tank container for thermosetting the thermosetting resin, the bubbles generated in the thermosetting resin are effectively removed by defoaming with an antifoaming agent. Can do. In addition, since the solvent of the antifoaming agent is the same component as the main component of the thermosetting resin, the thermosetting resin cannot be cured as in the conventional case, and the strength reduction or peeling of the formed fiber reinforced resin layer, etc. The occurrence of this problem can be suppressed.

  In addition, this invention can be implement | achieved with various forms, for example, can be implement | achieved with forms, such as a manufacturing method and manufacturing apparatus of a gas tank. Further, the present invention can be realized in the form of a gas tank manufactured by the above-described gas tank manufacturing method and manufacturing apparatus, a system such as a fuel cell system including the gas tank, a vehicle equipped with the gas tank, and the like.

It is explanatory drawing which shows the procedure of the manufacturing process of the high pressure gas tank by FW method. It is a schematic diagram for demonstrating the preparation process of a tank container. It is the schematic which shows the structure of the thermosetting processing apparatus which performs a thermosetting process. It is a schematic diagram for demonstrating in detail the mechanism of the bubble generation | occurrence | production during a thermosetting process. It is a schematic diagram for demonstrating bubble removal processing.

  FIG. 1 is a flowchart showing a procedure of a manufacturing process of a high-pressure gas tank by a filament winding method as one embodiment of the present invention. In the manufacturing process of the present embodiment, as a first process, a tank container called a “liner” that constitutes the main body of the high-pressure gas tank is prepared (step S10). In this step, as will be described later, a fiber layer is formed on the outer surface of the tank container by reinforcing fibers impregnated with a thermosetting resin.

  In the second step, the tank container in which the fiber layer is formed is heated to thermally cure the thermosetting resin in the fiber layer, and a thermosetting process is performed in which the fiber layer is used as a fiber reinforced resin layer (step S20). ). In the second step, as will be described later, a bubble removal process for removing bubbles generated in the surface layer of the fiber reinforced resin layer is performed during the execution of the thermosetting process. In the third step, a part such as a predetermined metal fitting is attached to the tank container (step S30). This completes the high-pressure gas tank.

  FIG. 2 is a schematic diagram illustrating an example of a tank container preparation step, which is the first step of FIG. 1. FIG. 2A schematically shows the tank container 10 before the fiber layer is formed. The tank container 10 is a hollow container having a substantially cylindrical cylinder part 11 and substantially hemispherical dome parts 13 provided at both ends thereof. The tank container 10 is made of, for example, a resin such as nylon resin.

  Here, the top portions of the two dome portions 13 are respectively present on the same central axis CX (illustrated by a one-dot chain line) of the tank container 10. At the top of each dome portion 13, a cap portion 14 to which a pipe and a valve are attached in the third step (step S <b> 30 in FIG. 1) is provided. In addition, the tank container 10 may have another shape and may be configured by other members.

  FIG. 2B schematically shows a process of forming the fiber layer 21 by winding the carbon fiber 20 around the outer surface of the tank container 10. FIG. 2C schematically shows the tank container 10 after the fiber layer 21 is formed. In the manufacturing process of the present embodiment, the fiber layer 21 that covers the outer surfaces of the cylinder part 11 and the dome part 13 is formed by winding the carbon fiber 20 that is a reinforcing fiber in the preparation process of the tank container 10. The carbon fiber 20 is impregnated with an epoxy resin that is a thermosetting resin in advance. The carbon fiber 20 is wound by combining so-called hoop winding or helical winding. Moreover, as the carbon fiber 20 to be wound, the carbon fiber forming the outer surface portion (also referred to as “surface layer portion”) to which the antifoaming agent solution is applied forms the other portion (also referred to as “inner layer portion”). On the basis of the composition ratio of the epoxy resin main agent and the curing agent impregnated in the carbon fiber, the epoxy resin having an excessive composition ratio of the curing agent is impregnated. This reason will be described later.

  FIG. 3 is a schematic diagram illustrating a configuration of the thermosetting apparatus 100 that performs the thermosetting process and the bubble removing process in the second step. The thermosetting apparatus 100 includes a control unit 101, a base 110, a heating unit 120, and an antifoaming agent application unit 150. The control part 101 can be comprised by the microcomputer provided with a main memory and a central processing unit, and controls each structure part of the thermosetting processing apparatus 100 demonstrated below.

  The base 110 has tank mounting portions 111 and 112 as shafts for holding the tank container 10 from both ends so that the tank container 10 can be rotated at a predetermined rotation speed around the central axis CX of the tank container 10. doing. In addition, the base 110 has a rotation driving unit 113 that applies a rotation driving force to the tank container 10 via the tank attachment units 111 and 112 based on a command from the control unit 101.

  The heating unit 120 is provided so that the entire tank container 10 rotated by the rotation driving unit 113 can be heated at a predetermined temperature (for example, about 130 ° C.). The antifoaming agent application unit 150 includes an antifoaming agent tank 151 filled with an antifoaming agent solution, a plurality of spray nozzles 152 for applying the antifoaming agent solution, each spray nozzle 152, and an antifoaming agent tank 151. And a pipe 153 for connecting the two. The defoamer application unit 150 is used for a bubble removal process described later.

  As the thermosetting treatment, the thermosetting treatment apparatus 100 rotates the tank container 10 attached to the tank attaching portions 111 and 112 at a predetermined rotation speed by the rotation driving portion 113 and about 7 to Heat for about 8 hours. Thereby, the thermosetting resin (epoxy resin in this example) impregnated in the carbon fiber 20 is thermoset. Here, in the thermosetting process, bubbles may be generated in the thermosetting resin of the fiber layer 21.

  FIG. 4 is a schematic diagram for explaining in detail the mechanism of bubble generation during the thermosetting process. 4A schematically illustrates a schematic cross section of the tank container 10 before the thermosetting treatment, and FIG. 4B schematically illustrates a schematic cross section of the tank container 10 during the thermosetting process. Is shown. In the fiber layer 21 of the tank container 10 before the thermosetting treatment, the carbon fibers 20 are wound in a multilayered manner in a tight state (FIG. 4A).

  When heating of the tank container 10 is started in the thermosetting process, the viscosity of the thermosetting resin 22 impregnated in the carbon fibers 20 starts to flow and starts to flow, and oozes out to the outside of the carbon fibers 20 (FIG. 4 (B)). As the thermosetting resin 22 flows, the tension of the carbon fibers 20 in the fiber layer 21 decreases, and the gap between the carbon fibers 20 increases. The thermosetting resin 22 starts to exude from the gap between the carbon fibers 20 to the outer surface side (surface layer side) of the fiber layer 21.

  In this way, the resin film 23 made of the thermosetting resin 22 is formed on the surface layer of the fiber layer 21. Thereafter, the heating by the heating unit 120 is continued, whereby the crosslinking reaction of the thermosetting resin 22 proceeds, and the thermosetting resin 22 of the fiber layer 21 is cured. Hereinafter, the fiber layer 21 after the thermosetting resin 22 is cured is also referred to as a “fiber reinforced resin layer 25”.

  By the way, in the fiber layer 21 formed in the tank container 10, air that has entered between the carbon fibers 20 when the carbon fibers 20 are wound, or originally enters the carbon fibers 20 together with the thermosetting resin 22. There was air that was. In the thermosetting treatment step described above, when the thermosetting resin 22 is in a fluid state before being cured, bubbles are generated in the thermosetting resin 22 by such air, and the bubbles 26 are It is deposited on the outer surface of the resin coating 23 formed on the surface of the fiber layer 21. When the thermosetting resin 22 is cured while the bubbles 26 are generated, irregularities corresponding to the size of the bubbles are formed on the surface of the formed fiber layer 21, and the smoothness of the fiber reinforced resin layer 25 is impaired.

  In the thermosetting apparatus 100 of the embodiment, the antifoaming agent solution is applied to the tank container 10 by the antifoaming agent application unit 150 as the bubble removal process executed during the thermosetting process. FIG. 5 is a schematic diagram for explaining the bubble removal processing. FIG. 5A schematically shows a state where the antifoaming agent solution 154 is applied to the surface of the fiber layer 21 during the thermosetting treatment. When the antifoaming agent solution 154 is applied to the surface of the fiber layer 21, the antifoaming agent 156 in the antifoaming agent solution 154 comes into contact with the bubbles 26 deposited on the surface layer of the resin coating 23, thereby promoting foam breakage. Thus, the bubble removal process is executed. The antifoaming agent solution 154 is applied during the thermosetting process because the higher the temperature, the lower the viscosity of the solvent, so that it becomes easier to apply the antifoaming agent uniformly, and the generated bubbles are broken. This is because it is effective.

  Here, the antifoaming agent solution 154 is a solution in which the antifoaming agent 156 is mixed with the solvent 155. As the antifoaming agent 156, a foam-breaking polymer or a silicon-based desorbing agent that is generally used as a demolding agent for the epoxy resin that is the thermosetting resin 22 is used. For example, various defoaming agents such as defoaming agents BYK-A506 and BYK-A535 manufactured by Big Chemie can be used as defoaming agents for epoxy resins. As the solvent 155, as described in the prior art, generally, an organic solvent such as toluene, methyl elketone (MEK), or naphtha is used. However, in the present embodiment, a substance having the same component as that of the main component constituting the epoxy resin, which is the thermosetting resin 22 impregnated in the fiber layer 21, is used as the solvent instead of these general solvents. However, the curing agent constituting the epoxy resin is not included. In this embodiment, as the epoxy resin, which is the thermosetting resin 22 impregnated in the fiber layer 21, an antifoaming agent is used because the main component is a bisphenol F type and the curing agent is an aromatic amine-based composition. As the solvent 155 of the solution 154, the same bisphenol F type as the main component of the epoxy resin is used. Assuming that the epoxy resin used is bisphenol A type and the curing agent is an acid anhydride type composition, the solvent of the antifoaming solution in this case is the same as the epoxy resin main agent. Bisphenol A type will be used. The same applies to other epoxy resins, and the main agent may be used as a solvent.

  By the way, as described above, the solvent 155 of the antifoaming agent 156 does not include the curing agent contained in the epoxy resin used as the thermosetting resin. Cross-linking reaction does not proceed. For this reason, the curing of the solvent 155 does not proceed, and the strength of the surface of the fiber layer 21 to which the antifoaming agent solution 154 is applied cannot be obtained.

  However, as described above, the thermosetting resin 22b on the surface layer of the fiber layer 21 to which the antifoaming agent solution 154 is applied has a composition ratio of an excessive curing agent compared to the composition of the thermosetting resin 22a of the inner layer. Yes. For this reason, the solvent 155 of the antifoaming agent solution 154 is mixed with an excessive amount of the curing agent of the thermosetting resin 22b of the surface layer, and the solvent 155 that does not contain the curing agent can be cured by proceeding with the crosslinking reaction. .

  As a result, the strength of the surface of the fiber layer 21 to which the antifoaming agent solution 154 is applied can be secured, and the smoothness of the surface of the formed fiber reinforced resin layer 25 can be improved. That is, the reason why the thermosetting resin 22b on the surface layer of the fiber layer 21 is set to a composition ratio of excessive curing agent compared to the composition ratio of the thermosetting resin 22a of the inner layer is for the reason described above. The composition ratio of the curing agent excess depends on the amount of the antifoam solution to be applied, that is, the amount of the solvent contained in the antifoam solution to be applied. Is.

  Here, it is conceivable that a curing agent is included as a solvent for the antifoaming agent, and the composition ratio of the thermosetting resin in the surface layer portion to which the antifoaming agent is applied is not set to an excessive curing agent state. However, in this case, there is a high possibility that the solvent is cured first and the effect of promoting bubble removal is suppressed, which is not preferable. Also, there is a possibility that the antifoaming agent solution will harden in the components such as spray nozzles and pipes of the antifoaming agent application part for applying the antifoaming agent, and cleaning work and parts replacement work will be performed appropriately. Necessary. On the other hand, if the solvent does not contain a curing agent as in the embodiment, the solvent can be cured according to the progress of the bubble removal process, so that the bubble removal can be executed effectively. It is. In addition, since the antifoaming agent solution does not harden in the component parts such as the spray nozzle of the antifoaming agent application section and the piping for applying the antifoaming agent, cleaning work and parts replacement work are unnecessary. Become.

  As described above, the organic solvent that has been generally used by making the solvent of the antifoaming agent the same component as the main component constituting the thermosetting resin and not containing the curing agent. It can suppress that it becomes impossible to harden | cure a thermosetting resin by reacting with the main ingredient which comprises a thermosetting resin like a solvent. Thereby, it can prevent that the intensity | strength of the surface layer part of the fiber reinforced resin layer formed falls, or the surface layer part of a fiber reinforced resin layer peels.

  In addition, this invention is not restricted to said Example and embodiment, In the range which does not deviate from the summary, it is possible to implement in various aspects.

  In the said Example, although the epoxy resin was demonstrated to the example as a thermosetting resin, it is not limited to this, It can apply similarly in various thermosetting resins.

DESCRIPTION OF SYMBOLS 10 ... Tank container 11 ... Cylinder part 13 ... Dome part 14 ... Cap part 20 ... Carbon fiber 21 ... Fiber layer 22 ... Thermosetting resin 22a, 22b ... Thermosetting resin 23 ... Resin coating 25 ... Fiber reinforced resin layer 26 ... Bubble 100 ... Thermosetting apparatus 101 ... Control part 110 ... Base 111, 112 ... Tank mounting part 113 ... Rotation drive part 120 ... Heating part 150 ... Antifoaming agent application part 151 ... Antifoaming agent tank 152 ... Spray nozzle 153 ... Plumbing

Claims (4)

A method for manufacturing a high-pressure gas tank, comprising:
A tank container having a fiber layer formed by winding a reinforcing fiber impregnated with a thermosetting resin containing a main agent and a curing agent is heated on the outer surface, and the thermosetting resin is thermoset to produce a fiber reinforced resin. While performing a thermosetting treatment to form a layer, bubbles generated in the thermosetting resin are removed by defoaming with an antifoaming agent in an antifoaming agent solution applied to the outer surface of the fiber layer. Comprising the steps of:
The antifoaming agent solution is a mixture of the antifoaming agent and a solvent having the same component as the main component of the thermosetting resin. The manufacturing method according to claim 1,
Of the fiber layer, the thermosetting resin impregnated in the reinforcing fiber forming the outer surface portion to which the antifoaming agent solution is applied is the thermosetting resin impregnated in the reinforcing fiber forming the other portion. A production method characterized by having a composition ratio of an excess of a curing agent in which the ratio of the curing agent is increased as compared with the composition ratio of the main agent and the curing agent. It is a manufacturing method of Claim 1 or Claim 2, Comprising:
Application of the defoamer solution to the outer surface of the fiber layer is performed during execution of the thermosetting treatment. An apparatus for manufacturing a high-pressure gas tank,
A tank container having a fiber layer formed by winding a reinforcing fiber impregnated with a thermosetting resin containing a main agent and a curing agent is heated on the outer surface, and the thermosetting resin is thermoset to produce a fiber reinforced resin. A thermosetting treatment part for forming a layer;
When the thermosetting treatment is heating the tank container, an antifoaming agent solution containing an antifoaming agent for breaking bubbles generated during the formation of the reinforcing fibers is applied to the outer surface of the fiber layer. An anti-foaming agent application part,
With
The defoaming agent solution is a mixture of the defoaming agent and a solvent having the same component as the main component of the thermosetting resin.

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