JP2011230321A - Method of molding high pressure tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of molding a high pressure tank which prevents a resin of an inner layer from oozing out to the outer layer side and achieves uniformity in a ratio (Vf) between a fiber and the resin in the layer of a FRP layer in the high pressure tank.SOLUTION: The method of molding the high pressure tank includes steps of: forming the inner layer (S100) by winding the fiber impregnated with a first thermosetting resin in an uncured state around a hollow liner; forming the outer layer (S102) by winding the fiber impregnated with a second thermosetting resin in the uncured state around the inner layer; and curing the FRP layer (S104) by heating from the outer layer side. The second thermosetting resin has a curing property which cures the thermosetting resin before the first thermosetting resin is lowered in viscosity during heat curing.

Description

  The present invention relates to a method for molding a high-pressure tank.

  A high pressure vessel such as a high pressure tank uses an FRP (Fiber Reinforced Plastic) member that is lighter and tougher than iron or the like, and an FRP layer made of an FRP member is formed on the surface of the substrate. Here, the FRP member includes, for example, a fiber and a resin and is reinforced with plastic.

  As a method for forming the FRP layer, for example, a filament winding method (hereinafter also referred to as “FW method”) is known. In this filament winding method, a fiber impregnated with a resin is wound around a cylindrical substrate, This is a method of forming an FRP layer. After forming the FRP layer, usually a thermosetting treatment is performed.

  For example, Patent Document 1 discloses a liner, a first layer formed in an outer layer of the liner and containing fibers and a curable resin, and a fiber and an elastomeric thermosetting resin or thermosetting formed in the outer layer of the first layer. An FRP molded body having a second layer containing a curable resin is disclosed, and further, an elastomeric thermosetting resin or a thermosetting resin contained in the second layer is contained in the first layer. It is described that it has a melting point or decomposition temperature higher than the curing temperature of the thermosetting resin.

  Patent Document 2 describes a method for producing a multilayer FRP layer using a matrix resin that uses a resin having a higher curing start temperature toward the outside of the FRP layer. According to the above production method, the matrix resin of the inner layer is described. Is described as being able to suppress oozing out of the FRP layer. The matrix resin is composed of a main agent made of resin and a curing agent for curing the resin.

  On the other hand, in Patent Document 3, an outer layer structure of a high-speed vehicle is formed of a composite material in which a thermosetting synthetic resin is impregnated with a fiber reinforced material containing high-elasticity fibers in order to prevent fatigue failure due to repeated loads and the like. And an outer layer formed by a composite material obtained by impregnating a thermosetting synthetic resin into a fiber reinforced material containing high elastic fibers, and an intermediate layer disposed between the inner layer and the outer layer, It is described that it has a core that is fixed to an inner layer and an outer layer and in which a large number of spaces are formed. Moreover, it describes that a core consists of hard foaming synthetic resins.

JP 2008-238491 A JP 2008-126615 A JP 11-78874 A

  After the resin-impregnated fiber is wound and the FRP molded body is formed, when the resin is cured by heating or the like, the thermosetting resin having a relatively low curing rate is reduced in viscosity, and thereby the inner layer thermosetting resin Oozes out to the outer layer side. Conventionally, in the FRP molded body, a method for preventing the inner layer resin from oozing out of the outer layer has been proposed. However, in recent years, the inner layer unit of the FRP molded body is further suppressed by further preventing the inner layer resin from oozing out. There is a demand for uniform ratio of fiber to resin per volume (Vf: fiber volume content, fiber volume content).

  The present invention has been made in view of the above problems, and prevents the inner layer resin from exuding to the outer layer side, and makes the ratio of fibers to resin (Vf) uniform in the FRP layer in the high-pressure tank. Provided is a method for molding the illustrated high-pressure tank.

  In order to achieve the above object, the method for molding a high-pressure tank of the present invention has the following characteristics.

  (1) A step of forming an inner layer by winding a fiber impregnated with an uncured first thermosetting resin around a hollow liner, and a fiber impregnated with an uncured second thermosetting resin And forming the outer layer by winding the inner layer on the inner layer, and the step of heating and curing from the outer layer side. The second thermosetting resin has the first thermosetting resin at the time of heat curing. This is a method for molding a high-pressure tank having a curing property of curing before the viscosity is lowered.

  As the first thermosetting resin, a resin having a relatively low curing speed is used in consideration of the winding operation time of the resin-impregnated fiber, and thus the viscosity tends to be lowered during heat curing. Therefore, as described above, the second thermosetting resin, which is cured before the first thermosetting resin is reduced in viscosity, is cured by heating from the outer layer side to cure the second thermosetting resin. Is cured at a high speed first to serve as an “outer shell”, and as a result, it is possible to prevent the first thermosetting resin of the inner layer from seeping out to the outer layer side.

  (2) winding the fiber impregnated with the uncured first thermosetting resin around a hollow liner to form an inner layer, winding the fiber around the inner layer to form a pre-outer layer, A step of applying a cured second thermosetting resin to the pre-outer layer, and a step of curing by heating from the outer layer side. This is a method for molding a high-pressure tank having a curing characteristic that cures before the thermosetting resin of 1 is reduced in viscosity.

  After forming the pre outer layer, the second thermosetting resin can be used by applying the second thermosetting resin, which has a faster curing speed than the molding method described in (1) above. As a result, when heated from the outer layer side, the second thermosetting resin cures faster than in the case described in (1) above, and the cured outer layer serves as an “outer shell”. It is possible to prevent the first thermosetting resin in the inner layer from oozing out.

  (3) A process in which a fiber impregnated with an uncured thermosetting resin is wound around a hollow liner to form an inner layer, and a porous base material is disposed on the inner layer or a heat-resistant foaming resin is applied for heat insulation Forming a layer, winding a fiber impregnated with an uncured thermosetting resin around the heat insulating layer to form an outer layer, heating from the outer layer side to cure, and a liner after curing of the outer layer And a step of curing by heating from the inside of the high pressure tank.

  The heat from the outer layer is transferred to the outer layer and contributes to the curing of the thermosetting resin in the outer layer, but the heat insulating layer functions as a `` barrier layer '', so it is difficult to transfer to the inner layer, and the thermosetting resin in the inner layer is low. Viscosity is suppressed. As a result, the outer layer is first cured to form an “outer shell”, and then the inner layer thermosetting resin is cured by heating from the inside of the liner, so that the inner layer thermosetting resin oozes out to the outer layer side. Can be prevented.

  (4) a step of forming an inner layer by winding fibers impregnated with an uncured thermosetting resin around a hollow liner, a step of applying a heat-resistant foamable resin to the inner layer to form a heat insulating layer, and heat insulation A step of preheating from the layer side to foam the heat resistant foamable resin to form a foam heat insulating layer, and a step of winding an uncured thermosetting resin impregnated fiber around the foam heat insulating layer to form an outer layer And a step of heating and curing from the outer layer side, and a step of heating and curing from the liner side after the outer layer is cured.

  When a heat-resistant foamable resin is used for the heat insulating layer, the heat-resistant foamable resin is foamed by preheating to form a foamed heat-insulating layer before forming the outer layer, thereby making it more heat-insulating than the molding method described in (3) above. Increases effectiveness. Therefore, since the foam insulation layer with higher heat insulation function functions as a `` barrier layer '', the heat from the outer layer side is transmitted to the outer layer and contributes to the curing of the thermosetting resin of the outer layer, but it is difficult to transmit to the inner layer, Lowering the viscosity of the inner layer thermosetting resin is prevented. As a result, the outer layer is first cured to form an “outer shell”, and then the inner layer thermosetting resin is cured by heating from the inside of the liner, so that the inner layer thermosetting resin oozes out to the outer layer side. Can be prevented.

  (5) In the method for molding a high-pressure tank described in (3) or (4) above, the thermosetting resin for forming the outer layer has a low viscosity when the thermosetting resin for forming the inner layer is heat-cured. It has a curing property that cures before being converted.

  By changing the curing characteristics of the thermosetting resin used in the inner layer and the outer layer, the seepage of the thermosetting resin in the inner layer can be suppressed.

  According to the present invention, it is possible to suppress the inner layer resin from seeping out to the outer layer side, and to achieve a uniform ratio (Vf) between the fibers and the resin in the FRP layer in the high-pressure tank.

It is a graph which shows an example of the relationship between the viscosity of the thermosetting resin used for an inner layer, and temperature. It is a schematic diagram explaining the initial state at the time of heating and hardening a tank after winding the fiber impregnated with thermosetting resin by the conventional shaping | molding method and forming a FRP layer. It is a schematic diagram explaining the initial state at the time of heating and hardening a tank after winding the fiber impregnated with the thermosetting resin by the molding method of the present invention to form an FRP layer. FIG. 4 is an enlarged cross-sectional view of a portion X surrounded by a dashed line in FIG. 3. FIG. 5 is an enlarged cross-sectional view of a Y portion surrounded by a dashed line in FIG. 4. It is a flowchart explaining an example of the shaping | molding method of the high pressure tank in embodiment of this invention. It is a flowchart explaining the other example of the shaping | molding method of the high pressure tank in embodiment of this invention. It is a flowchart explaining the other example of the shaping | molding method of the high pressure tank in embodiment of this invention. It is a flowchart explaining the other example of the shaping | molding method of the high pressure tank in embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  Generally, a high-pressure tank is formed by winding a fiber impregnated with a thermosetting resin around a hollow liner by an FW method or the like to form an FRP layer, curing the thermosetting resin of the FRP layer, and then at least one end. It is formed by attaching a base part. Furthermore, in order to ensure the pressure resistance of the high-pressure tank, the FRP layer has a certain thickness. Therefore, the fiber impregnated with the thermosetting resin is wound around the liner a plurality of times. For this reason, the winding operation in one high-pressure tank requires a predetermined time, and since it is necessary to place the resin in an uncured state until the winding is completed, the thermosetting resin impregnated in the fiber is Usually, a thermosetting resin that is in an uncured state and has a relatively low curing rate is selected. As shown in FIG. 1, such a thermosetting resin having a relatively low curing speed has a viscosity of, for example, honey as shown by point A at the temperature at the completion of winding (for example, 25 ° C.). On the other hand, at a temperature at the initial stage of heat curing (for example, 100 ° C.), fluidity is superior to curing, and the viscosity is lowered as indicated by point B, and the fluidity is changed to a high fluidity level such as edible oil. As a result, when the FRP layer is formed using only the thermosetting resin as shown in FIG. 1, as shown in FIG. 2, the tank 20 after the formation of the FRP layer has the FRP layer at the temperature when the winding is completed. Even if the resin does not ooze out from the inner layer, the tank 22 at the initial stage of heat curing in the heating furnace 30 bleeds out the resin from the inner layer of the FRP layer.

  Therefore, in the present invention, by using an example of a high-pressure tank molding method described below, as shown in FIG. 3, the tank 10 after the formation of the FRP layer has a temperature at the time of completion of winding at the inside of the FRP layer. There is no seepage of resin from the layer, and even in the tank 12 at the initial stage of heat curing in the heating furnace 30, there is no seepage of resin from the inner layer of the FRP layer, and the fibers and thermosetting in the thickness direction of the FRP layer. A uniform ratio (Vf) with the resin can be obtained.

  First, an example of a method for molding a high-pressure tank in the embodiment of the present invention will be described with reference to FIG. As shown in FIG. 6, the method for molding a high-pressure tank according to the first embodiment is a process of forming an inner layer by winding a fiber impregnated with an uncured first thermosetting resin around a hollow liner ( S100), a step of winding the fiber impregnated with the uncured second thermosetting resin around the inner layer to form the outer layer (S102), and a step of heating from the outer layer side to cure the FRP layer (S104) The second thermosetting resin has a curing property that cures before the first thermosetting resin has a reduced viscosity during heat curing.

  The material of the liner is not particularly limited, and examples thereof include polyethylene, polypropylene resin, and other hard resins in addition to metals.

  Examples of the fibers 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). As a fiber in this embodiment, a carbon fiber is preferable.

  The first thermosetting resin used for the inner layer is made of a mixture of a resin and a curing agent, and the resin may be any resin as long as it is a resin that is thermoset by reaction with the curing agent. , Urea resin, unsaturated polyester resin, vinyl ester resin, polyimide resin, bismaleimide resin, polyurethane resin, diallyl phthalate resin, epoxy resin and the like. The main agent is preferably an epoxy resin, which may be linear or branched.

  The curing agent may be any curing agent as long as a thermosetting resin can be obtained by reaction. Examples thereof include primary, secondary, and tertiary amines such as aliphatic amines, aromatic amines, and modified amines. Specifically, amine-based curing such as piperidine, N, N-dimethylpiperazine, triethylenediamine, 2,4,6-tris (dimethylaminomethyl) phenol, benzyldimethylamine, 2- (dimethylaminomethyl) phenol Agents, polyamide resins, mercaptan-based curing agents, and thiol-based curing agents such as triazine thiol.

  Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol AD type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, and glycidyl ester type epoxy resin. The first thermosetting resin in the present embodiment may be used by appropriately selecting and blending the above-described epoxy resin and curing agent so that curing is completed in about 1 hour at about 130 ° C., for example. preferable.

  On the other hand, the second thermosetting resin used for the outer layer is a thermosetting resin that can be cured at a temperature in the range of about 60 ° C. to about 100 ° C., which reduces the viscosity of the first thermosetting resin used for the inner layer. Any resin can be used, but a thermosetting resin that completes curing in 30 to 40 minutes in the range of about 50 ° C. to about 60 ° C. is preferable. Examples of such second thermosetting resin include product names “AE-100”, “AE-300”, and “AE-400”, which are one-part epoxy resins manufactured by Ajinomoto Fine Techno Co., Ltd. It is done.

  As described above, the second thermosetting resin, which cures before the viscosity of the first thermosetting resin is lowered, is cured by heating from the outer layer side to cure the outer layer first. It is cured at a high speed to serve as an “outer shell”, and as a result, the seepage of the first thermosetting resin to the outer layer side is suppressed, and the fibers and thermosetting resin in the thickness direction of the FRP layer are suppressed. The ratio (Vf) is uniform.

  Next, another example of the method for forming a high-pressure tank in the embodiment of the present invention will be described with reference to FIG. As shown in FIG. 7, the method for molding a high-pressure tank according to the second embodiment is a process of forming an inner layer by winding fibers impregnated with an uncured first thermosetting resin around a hollow liner ( S100), a step of winding a fiber around the inner layer to form a pre-outer layer (S112), a step of applying an uncured second thermosetting resin to the pre-outer layer (S114), and heating from the outer layer side And the step of curing (S104), and the second thermosetting resin has a curing characteristic that cures before the first thermosetting resin is reduced in viscosity during heat curing.

  The liner, fiber, first thermosetting resin, and second thermosetting resin in the method for molding a high-pressure tank of the second embodiment are the same as those in the first embodiment described above, and therefore the description thereof. Is omitted.

  After the pre-outer layer is formed, the second thermosetting resin is applied, thereby using the second thermosetting resin having a higher curing rate than the molding method of the high-pressure tank in the first embodiment described above. be able to. As a result, when heated from the outer layer side, the second thermosetting resin hardens faster than the molding method of the high-pressure tank in the first embodiment described above, and the cured outer layer serves as the “outer shell”. Therefore, the first thermosetting resin oozes out to the outer layer side, and the ratio (Vf) between the fibers and the thermosetting resin in the thickness direction of the FRP layer is made uniform.

  Next, another example of the molding method of the high-pressure tank in the embodiment of the present invention will be described with reference to FIG. As shown in FIG. 8, the method for molding a high-pressure tank according to the third embodiment includes a step of forming an inner layer by winding a fiber impregnated with an uncured thermosetting resin around a hollow liner (S120). A step (S122) of forming a heat insulating layer by disposing a porous base material on the inner layer or applying a heat-resistant foaming resin, and winding a fiber impregnated with an uncured thermosetting resin around the heat insulating layer A step of forming the outer layer (S124), a step of heating and curing from the outer layer side (S126), and a step of heating and curing from the inside of the liner after curing of the outer layer (S128).

  Since the liner and fiber in the method for molding a high-pressure tank according to the third embodiment are the same as those in the first embodiment described above, the description thereof is omitted. Further, the thermosetting resin used for the inner layer and the outer layer may be the same thermosetting resin or different thermosetting resins. When the thermosetting resins are different, the first and second thermosetting resins are used. The first thermosetting resin used in the embodiment is used as the inner layer thermosetting resin, while the second thermosetting resin used in the first and second embodiments is used for the outer layer. preferable.

  As a porous base material used for the heat insulating layer, any base material may be used as long as it is a porous base material capable of holding an air layer. For example, a lath cut metal or an expanded metal can be used. Here, “lass-cut metal” is a plate-like thin metal plate that has been formed by sequentially forming staggered cuts and pressing and bending the cut cuts to form a small through-hole with a mesh shape. It is. In addition, “expanded metal” is a thin metal plate that is formed in a zigzag pattern on a flat thin metal plate, and a small through-hole with a mesh shape is formed by pressing and bending the processed cut. It is processed into a substantially flat plate shape.

  When the heat-insulating layer is formed by applying a heat-resistant foaming resin, examples of the heat-resistant foaming resin include “Kanepal” (registered trademark) and “Heatmax HM5” of heat-resistant foaming polystyrene resins manufactured by Kaneka Corporation. ("Heat Max" is a registered trademark). In consideration of the pressure resistance of the high-pressure tank, the foamability of the heat-resistant foamable resin and the thickness of the heat insulating layer are appropriately selected.

  The application of the heat-resistant foamable resin is appropriately selected from coating methods such as brush coating, roll coating, spray coating, and roll coater.

  In the step of curing by heating from the outer layer side (S126), the conventional heating furnace is used to heat and cure from the outer layer side of the FRP layer. On the other hand, in the step of curing by heating from the inside of the liner after curing of the outer layer (S128), the inside of the liner is filled with a high-temperature gas and heated, or heating using microwaves, electromagnetic dielectric heating (IH) ) Etc. are used.

  The structure of the high-pressure tank molded by the high-pressure tank molding method of the third embodiment will be described below with reference to FIGS. As shown in FIG. 4, the FRP layer 16 is formed on the hollow liner 14. FIG. 5 is an enlarged view of the Y portion surrounded by the dashed line in FIG. 4. As shown in FIG. 5, the FRP layer 16 formed on the liner 14 is an inner layer formed relatively thick on the liner 14. 15, a heat insulating layer 17 formed on the inner layer 15, and an outer layer 18 formed on the heat insulating layer 17.

  According to the molding method of the high-pressure tank in the third embodiment, heat from the outer layer side is transmitted to the outer layer and contributes to the curing of the thermosetting resin of the outer layer, but the heat insulating layer functions as a “barrier layer”. Therefore, it is difficult to transmit to the inner layer, and the lowering of the viscosity of the thermosetting resin of the inner layer is suppressed. In particular, when the heat-insulating layer is formed by applying a heat-resistant foamable resin, the heat-resistant foamable resin is foamed by heat from the outer layer side to form a foamed heat-insulating layer, and this foamed heat-insulating layer functions as a “barrier layer”. As a result, the outer layer is first cured to form an “outer shell”, and then the inner layer thermosetting resin is cured by heating from the inside of the liner, so that the inner layer thermosetting resin oozes out to the outer layer side. Can be prevented. Further, the ratio (Vf) between the fibers and the thermosetting resin in the thickness direction of the FRP layer is also made uniform.

  Next, another example of the molding method of the high-pressure tank in the embodiment of the present invention will be described with reference to FIG. As shown in FIG. 9, the molding method of the high-pressure tank of the fourth embodiment includes a step (S120) of forming an inner layer by winding a fiber impregnated with an uncured thermosetting resin around a hollow liner. A step of applying a heat-resistant foamable resin to the inner layer to form a heat-insulating layer (S132), a step of preheating from the heat-insulating layer side to foam the heat-resistant foamable resin to form a foamed heat-insulating layer (S134), A step of forming an outer layer by winding fibers impregnated with an uncured thermosetting resin around a foam heat insulating layer (S136), a step of curing by heating from the outer layer side (S126), and a liner after curing of the outer layer A step of heating and curing from the inside (S128).

  The liner and fiber in the method for molding a high-pressure tank according to the fourth embodiment are the same as those in the first embodiment described above, and thus the description thereof is omitted. Moreover, since the heat-resistant foamable resin and the inner layer heat curing method in the molding method of the high-pressure tank of the fourth embodiment are the same as those of the third embodiment described above, description thereof is omitted. Further, the thermosetting resin used for the inner layer and the outer layer may be the same thermosetting resin or different thermosetting resins. When the thermosetting resins are different, the first and second thermosetting resins are used. The first thermosetting resin used in the embodiment is used as the inner layer thermosetting resin, while the second thermosetting resin used in the first and second embodiments is used for the outer layer. preferable.

  When a heat-resistant foamable resin is used as the heat insulation layer, the heat-resistant foamable resin is foamed by preheating to form a foam heat insulation layer before the outer layer is formed, compared with the molding method of the high-pressure tank of the third embodiment. In the state where the heat insulation effect is higher, heating from the outer layer side in the next step can be performed. Accordingly, the foam heat insulating layer having a higher heat insulating effect is made to function as a “barrier layer”, making it difficult for heat from the outer layer side to be transferred to the inner layer, thereby preventing the viscosity of the thermosetting resin in the inner layer from being lowered. Thereby, it can prevent that the thermosetting resin of an inner layer oozes out to an outer layer side, and the ratio (Vf) of the fiber and thermosetting resin in the thickness direction of a FRP layer is equalize | homogenized.

  The present invention is effective for any application as long as it uses a high-pressure tank, but can be used particularly for a high-pressure tank for supplying fuel gas to a fuel cell for vehicles.

  10, 20 Tank after formation of FRP layer, 12, 22 Heat curing initial tank, 14 liner, 15 inner layer, 16 FRP layer, 17 heat insulating layer, 18 outer layer, 30 heating furnace.

Claims (5)

Winding a fiber impregnated with an uncured first thermosetting resin around a hollow liner to form an inner layer;
Winding the fiber impregnated with the uncured second thermosetting resin around the inner layer to form the outer layer;
And heating and curing from the outer layer side,
The method for molding a high-pressure tank, wherein the second thermosetting resin has a curing property that cures before the first thermosetting resin has a reduced viscosity during heat curing. Winding a fiber impregnated with an uncured first thermosetting resin around a hollow liner to form an inner layer;
Forming a pre-outer layer by winding fibers around the inner layer;
Applying an uncured second thermosetting resin to the pre-outer layer;
And heating and curing from the outer layer side,
The method for molding a high-pressure tank, wherein the second thermosetting resin has a curing property that cures before the first thermosetting resin has a reduced viscosity during heat curing. Winding the fiber impregnated with an uncured thermosetting resin around a hollow liner to form an inner layer;
Arranging a porous base material in the inner layer or applying a heat-resistant foaming resin to form a heat insulating layer;
Winding the fiber impregnated with an uncured thermosetting resin around the heat insulating layer to form an outer layer;
Heating and curing from the outer layer side;
A step of curing by heating from the inside of the liner after curing of the outer layer;
A method for molding a high-pressure tank, comprising: Winding the fiber impregnated with an uncured thermosetting resin around a hollow liner to form an inner layer;
Applying a heat-resistant foamable resin to the inner layer to form a heat insulating layer;
A step of preheating from the heat insulating layer side to foam the heat-resistant foaming resin to form a foam heat insulating layer;
Winding the fiber impregnated with an uncured thermosetting resin around a foam heat insulating layer to form an outer layer;
Heating and curing from the outer layer side;
A step of curing by heating from the liner side after curing of the outer layer;
A method for molding a high-pressure tank, comprising: In the molding method of the high-pressure tank according to claim 3 or claim 4,
A method for molding a high-pressure tank, wherein the thermosetting resin for forming the outer layer has a curing property that cures before the viscosity of the thermosetting resin for forming the inner layer is reduced during heat curing.

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