KR20180001864A - Gas tank - Google Patents

Abstract

The present invention provides a plastic pressure gas container with improved sealing properties. The plastic pressure gas container of the present invention comprises: an inner liner layer and an outer liner layer which are made of a resin material; a shielding layer interposed between the inner liner layer and the outer liner layer, and made of a resin material having a gas permeability lower than that of the inner liner layer and the outer liner layer; and a nano-particle layer laminated on a surface of at least one of the shielding layer, the inner liner layer, and the outer liner layer, thereby having a laminate structure.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a pressure gas container made of plastic having airtightness.

Pressure gas containers for liquefied gas (LPG, LNG) are being replaced by plastics in order to lighten the weight in metal gas containers. The plastic gas container is basically made of a resin material such as polyethylene by blow molding, and a reinforcing layer such as FRP (fiber reinforced plastics) is laminated on the outer surface for reinforcing the strength.

However, an ordinary resin material such as polyethylene widely used in a pressure gas container made of plastic has an advantage of being excellent in strength, inexpensiveness, and easy molding, but inevitably permeation of gas occurs to some extent. Therefore, when the gas permeability of the resin material is high, a regulation may be applied that the gas can not be used as a plastic pressure gas container.

Accordingly, an object of the present invention is to provide a pressure gas container made of plastic with improved airtightness.

The object is achieved by a laminate comprising an inner liner layer and an outer liner layer made of a resin material; A shielding layer interposed between the inner liner layer and the outer liner layer and made of a resin material having lower gas permeability than the inner liner layer and the outer liner layer; And a nano particle layer laminated on the surface of at least any one of the shield layer, the inner liner layer and the outer liner layer. A material with low gas permeability is used, and the nano particle layer is coated to improve the airtightness of the plastic pressure gas container.

Here, the resin material of the inner liner layer and the outer liner layer may be polyethylene, and the resin material of the shielding layer may be polyamide. The inner liner layer and the outer liner layer are made of polyethylene to maintain the strength, and the shielding layer is made of polyamide to improve airtightness.

The nanoparticle layer may be a coating layer formed using a coating agent containing silicon oxide having a particle size of 25 nm or less. As a result, the airtightness of the plastic pressure gas container can be further improved.

A neck portion having a tubular flow path through which gas is introduced and discharged and having a fastening thread portion on an outer surface and an opening end in which a lamination end face of the outer liner layer is exposed; A cap boss which receives and engages an outer surface and an inner surface of the neck portion including the opening in the region of the opening end; And a sealing member accommodated in the cap boss and contacting the opening end. The airtightness is improved through the O-ring between the neck portion and the cap boss, and the cap boss accommodates the outer surface and the inner surface of the neck portion, thereby minimizing external deformation of the net portion, thereby improving the stability of the plastic pressure gas container.

The valve unit may further include a valve unit connected to the cap boss, the valve unit being capable of opening and closing the gas to and from the plastic pressure gas container.

According to the present invention, there is provided a plastic pressure gas container having a multilayer plastic laminated structure and a nanoparticle coating layer to improve airtightness.

Further, according to the preferred embodiment of the present invention, the airtightness is further improved by strengthening the airtight structure of the cap boss region.

1 is a perspective view of a plastic pressure gas container according to an embodiment of the present invention,
2 is an exploded perspective view of a plastic pressure gas container according to an embodiment of the present invention,
3 is a detailed sectional view showing a cross section of a plastic pressure gas container according to another embodiment of the present invention,
4 is an exemplary cross-sectional view illustrating a structure for charge discharge of a plastic pressure gas container according to another embodiment of the present invention.

Hereinafter, a plastic pressure gas container 1 according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view of a plastic pressure gas container 1 according to an embodiment of the present invention. The plastic pressure gas container 1 of Fig. 1 has a main body 10 which constitutes the appearance of a gas tank for storing gas. The cap boss 20 is fastened to the neck portion 150 of the main body 10. A valve unit 40 is connected to the upper portion of the cap boss 20 so as to allow the gas to flow into and out of the plastic pressure gas container 1. The detailed configuration is described with reference to FIG. 2 showing an exploded perspective view of the plastic pressure gas container 1 according to an embodiment of the present invention and FIG. 3 showing a detailed sectional view.

In the plastic pressure gas container 1, the container body 10 is made to be multilayered by a blow molding method using a plurality of resins. Each layer is formed by blow molding a resin pipe into a metal mold (2) in the form of a plastic pressure gas container (1). The outer liner layer 120, the shielding layer 130 and the inner liner layer 110 are blow-molded in this order to form the container body 10. A reinforcing layer 180 may be formed of a material such as fiber reinforced plastics (FRP) on the outer surface of the container body 10. As a result, the plastic pressure gas container 1 can maintain a more rigid strength. The reinforcing layer 180 is laminated to form the shape of the circular cylinder. The inner liner layer 110 and the outer liner layer 120 may be made of a resin material such as polyethylene.

The resin material such as polyethylene has strong strength when it is made into a container, has an advantage of being cheap, and is a material which is easy to mold. However, resin materials such as polyethylene are relatively higher in leakage than comparable resin materials having different gas permeabilities. A shielding layer 130 is formed using a polyamide resin material having a relatively low gas permeability in order to prevent leakage due to the gas permeability of the plastic pressure gas container 1 made of the resin material of polyethylene. The resin material of the polyamide is weaker than the polyethylene resin material but has a gas permeability much lower than that of the resin material of the polyamide so as to be interposed between the inner liner layer 110 and the outer liner layer 120, . Since the resin material of polyamide has a gas permeability which is significantly lower than that of the polyethylene resin material and thus has a good airtightness, the gas may leak outside in the pressure gas container 1 made of plastic, so that the nanoparticle layer 140 may be shielded from the shielding layer 130 ), At least one layer of the inner liner layer 110 and the outer liner layer 120 is coated to further lower the gas permeability of the plastic pressure gas container 10.

The wastewater materials such as polyethylenes and polyamides may have fine pores in the structure. Since the size of the pores is formed at the size level of the nanoparticles, the micropores are blocked by the nanoparticle coating agent to improve the airtightness. The nanoparticle layer 140 may be a coating layer formed using a coating agent containing silicon oxide having a particle size of 25 nm or less. The silicon oxide may be silica (SiO2), and the silica nanoparticles may block the gas permeation structure of the polyethylene resin and the polyamide resin to improve the airtightness. The coating agent of the nanoparticle layer 140 preferably has a particle size of 25 nm or less. The nanoparticles indicate particles of 100 nm or less and can be used as a coating agent, but when the resin material of polyethylene and polyamide is subjected to blow molding, fine pores of 25 nm or less are mainly formed. Therefore, the coating of 25 nm or less nanoparticles improves the airtightness more than the coating of 25 nm or more nanoparticles. In the above description, the coating material may be a material of silicon oxide, but it is preferable that the material is chemically and physically very stable. Other coating materials may be perhydropolysilazane, inorganic polysilazane, organic polysilazane, fluorinated compounds, silicon compounds, and the like.

The container body 10 forms a tubular flow path through which the gas flows in and has a neck portion 152 having an outer surface fastening screw portion 152 and an opening end 154 in which a lamination end face of the outer liner layer 120 is exposed 150 are formed.

The plastic pressure gas container 1 has a cap boss 20 which receives and engages the outer surface and the inner surface of the neck portion 150 including the opening end 154 in the region of the opening end 154. The cap boss 20 has an internal thread formed on its inner surface and is engaged with the fastening screw portion 152 of the neck portion 150 to be fastened. The cap boss 20 has a shape capable of accommodating the neck portion 150 and is engaged with the inner surface of the neck portion 150 by being in close contact with each other. Thereby, the neck portion 150 can be prevented from changing its shape due to external pressure or internal pressure. The cap boss 20 is designed to closely contact the inner surface of the neck portion 150, but the shape is not limited thereto. The radius of the opening support portion 158 of the cap boss 20 which closely contacts the inner surface of the neck portion 150 may become larger toward the unlocking direction of the cap boss 20 to the neck portion 150. The opening support portion 158 of the cap boss 20 is fastened to the neck portion 150 and can be further brought into close contact with the inner surface of the neck portion 150. [ When the cap boss 20 is fastened to the neck portion 150, a reinforcing layer 180 such as FRP (fiber reinforced plastics) is laminated on the outer surface. When the reinforcing layer 180 is laminated, the end shape of the cap boss 20 is provided in a flange shape protruding in the transverse direction with respect to the neck portion 150 so that the flange shape of the cap boss 20 protruding from the reinforcing layer 180 The cap boss 20 may be firmly fastened to the neck portion 150 and may be fastened with improved airtightness.

The plastic pressure gas container 1 has a neck portion 150 and a cap boss 20 which are connected to each other at an opening end 154 of the neck portion 150 in order to prevent gas from being leaked to the outside And a sealing member 30 that contacts the cap boss 20 to prevent gas leakage. Since the pressure gas container 1 made of plastic has a multilayer structure, there is a possibility that the gas inside may leak out between the respective layers. Therefore, the sealing member 30 is formed by covering the entire open end 154 of the multi- It may be preferable that it is formed so as to be in contact with and to be sealed. The sealing member 30 may be a sealing member 30 which is received in the sealing member receiving portion 156 formed at the opening end 154 and contacts the cap boss 20 to prevent gas leakage. When the cap boss 20 is partially received in the sealing member receiving portion 156 formed at the opening end 154 and the cap boss 20 is fastened to the neck portion 150, Thereby enhancing the airtightness between the fuel cell stack 150 and the fuel cell stack 150. The sealing member 30 may be located in the sealing member receiving portion 156 formed at the opening end so as to improve airtightness but is not limited thereto and can improve the airtightness between the cap boss 20 and the neck portion 150 Either is possible.

The upper portion of the cap boss 20 may have a thread formed on the inner side thereof so that the valve unit 40, which can be opened and closed to allow gas to flow into and out of the plastic pressure gas container 1, may be connected. The screw thread formed on the inner surface of the cap boss 20 is formed so as to become narrower toward the inside, so that when the valve unit 40 is engaged, the male thread of the corresponding shape is engaged with the thread formed on the inner surface of the cap boss 20, Lt; / RTI > The coupling between the valve unit 40 and the cap boss 20 is not limited thereto and may be shaped so that the valve unit 40 is connected to the cap boss 20 at one-touch. The valve unit 40 may be connected to the cap boss 20 so as to transfer the gas.

When the outer liner layer 120, the shielding layer 130, the nanoparticle layer 140 and the inner liner layer 110 are blow-molded and the container body 10 is formed, A plurality of resin-impregnated carbon fibers or glass fiber FRP (fiber reinforced plastics) are wound in various directions such as the circumferential direction and the longitudinal direction so as to be able to withstand the internal pressure load of the plastic pressure gas container 1 more. Such external treatment can be made to withstand a fire or the like.

The plastic pressure gas container 1 is filled with gas from the outside. Charge such as static electricity or the like may be accumulated in the plastic pressure gas container 1 without being discharged to the outside. The structure of one portion of the plastic pressure gas container 1 can be provided as shown in FIG. 4 so that no charge remains in the plastic pressure gas container 1 and can be discharged to the outside.

A protrusion protruding outward with respect to the plastic pressure gas container 1 is provided. The central portion of the protrusion is formed of a ground portion 160 integrally formed with the inner liner layer 110, and the protrusion surrounding the ground portion 160 The outer liner layer 120 may be integrally formed with the guide part 170 to guide the ground part 160 to be exposed to the outside. The exposed ground portion 160 may be V-shaped and recessed inward. It is preferable to form a vertex shape since the charge inside the plastic pressure gas container 1 must be discharged to the outside. Although the exposed ground portion 160 is depressed in a V-shape, it may be cone-shaped, quadrangular-pyramid-shaped such as a vertex, and may have a vertex formed like a needle-like shape. The shape of the depression is not limited. Since the inner liner layer 110 is extended from the grounding portion 160, the charge accumulated in the formed carbon black component contained in the inner liner layer 110 and the charges generated in the pressure gas container 1 made of plastic So that it is possible to prevent a safety accident that may occur when the gas is charged. The inner liner layer 110 is mixed with carbon black components to move the charge to the grounding part 160. When the plastic pressure gas container 1 is provided at an appropriate place, the inner liner layer 110 can contact the ground or other conductive material, have.

A plastic pressure gas container 1 according to an embodiment of the present invention is manufactured by blow molding.

The polyethylene tube for forming the outer liner layer 120 moves with a metal mold having an outer shape of the pressure gas container 1 made of plastic for blow molding. The mold is separated to accommodate the polyethylene tube, the polyethylene tube moves between the separated molds, and the nozzle of the blow molding machine is inserted into the upper part of the polyethylene tube located between the separated molds. The separated metal molds are joined together by burying the top and bottom of the polyethylene tube. After that, the mold picks up the top and bottom of the polyethylene tube so that the air does not escape. Then, the inside of the mold is made suitable for the blow molding of the polyethylene tube, and the gas is blown from the nozzle of the blow molding machine located at the top, A polyethylene tube forms the outer liner layer 120 so as to correspond to the inner surface shape of the outer liner layer. As such, the shielding layer 130 also laminate a polyamide resin onto the outer liner layer 120.

After the shielding layer 130 is formed, a liquid coating containing silicon oxide having a particle size of 25 nm or less for forming the nanoparticle layer 140 at the nozzle is injected into the shielding layer 130. A weak wind may be blown through the nozzle so that the injected liquid coating agent hardens inside the shielding layer 130 to form the nanoparticle layer 140. When the nanoparticle layer 140 is formed, the inner liner layer 110 is formed by blow molding using the polyethylene tube 5. The pressure gas container 1 made of plastic can be produced by blow molding as described above, but the present invention is not limited thereto. Although the nanoparticle layer 140 is formed between the shielding layer 140 and the inner liner layer 110 in the above example, the nanoparticle layer 140 is formed between the shielding layer 140 and the outer liner layer 120, 110). ≪ / RTI >

Thereafter, the cap boss 20 is fastened to the neck portion 150 and covers the FRP (fiber reinforced plastics) including the flange portion of the cap boss 20 to form a more rigid reinforcing layer 180. Whereby the plastic pressure gas container 1 is produced.

By forming the shielding layer 130 of a resin material such as polyamide or the like having a low gas permeability and coating the nanoparticle layer 140, gas leakage of the plastic pressure gas container 1 can be prevented as much as possible. Therefore, it is possible to provide a pressure gas container 1 made of plastic suitable for the relevant regulatory standard due to gas leakage. The plastic gas pressure container 1 with improved airtightness can prevent a safety accident, It can reduce air pollution of smell.

1: Plastic pressure gas container 10: Container body
20: cap boss 30: sealing member
40: valve unit 110: inner liner layer
120: outer liner layer 130: shield layer
140: nanoparticle layer 150: neck part
152: fastening screw part 154:
156: sealing member receiving portion 158: opening support
160: ground portion 170: guide portion
180: reinforcing layer 210: valve fastening part

Claims (5)

In a pressure gas container made of plastic having airtightness,
An inner liner layer and an outer liner layer made of a resin material;
A shielding layer interposed between the inner liner layer and the outer liner layer and made of a resin material having lower gas permeability than the inner liner layer and the outer liner layer;
And a nano particle layer laminated on the surface of at least one of the shielding layer, the inner liner layer, and the outer liner layer. The method according to claim 1,
Wherein the resin material of the inner liner layer and the outer liner layer is polyethylene, and the resin material of the shielding layer is polyamide. The method according to claim 1,
Wherein the nanoparticle layer is a coating layer formed using a coating agent containing silicon oxide having a particle size of 25 nm or less. 4. The method according to any one of claims 1 to 3,
A neck portion having a tubular flow path through which gas is introduced and discharged, a neck portion having a fastening thread portion on an outer surface thereof and an opening end through which a lamination end face of the outer liner layer is exposed;
A cap boss which receives and engages an outer surface and an inner surface of the neck portion including the opening in the region of the opening end;
And a sealing member accommodated in the cap boss and contacting the opening end. 5. The method of claim 4,
And a valve unit connected to the cap boss, the valve unit being capable of opening and closing the gas to and from the plastic pressure gas container.

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