KR102631439B1 - Secondary barrier for liquefied gas storage tank and manufacturing method thereof - Google Patents

Abstract

This specification relates to a secondary barrier for a liquefied gas storage tank and a method of manufacturing the same. The secondary barrier for a liquefied gas storage tank according to an embodiment of the present invention has excellent adhesion between aluminum foil and the reinforcing layer, adhesion at cryogenic temperatures, and flexibility in terms of sealing performance, and is excellent in flexibility with respect to sealing performance, and is excellent in liquefaction according to an embodiment of the present invention. The manufacturing method of the secondary barrier for gas storage tanks simplifies the process and has the effect of reducing costs and process time.

Description

Secondary barrier for liquefied gas storage tank and method of manufacturing same {SECONDARY BARRIER FOR LIQUEFIED GAS STORAGE TANK AND MANUFACTURING METHOD THEREOF}

Disclosed herein is a secondary barrier for a liquefied gas storage tank and a method for manufacturing the same.

Liquefied Natural Gas (LNG) is a cryogenic liquid whose volume is reduced to 1/600 by compressing, cooling, and liquefying hydrocarbon-based natural gas extracted from underground at a cryogenic temperature of -162 degrees for convenience of transportation and storage. says The storage tank (commonly referred to as a cargo hold) applied to an LNG carrier carrying such LNG is divided into an independent tank type LNG storage tank and a membrane type depending on whether the load of the cargo acts directly on the insulation material. Type) It can be classified as an LNG storage tank, and the membrane type with excellent loading capacity is especially preferred. However, because the membrane-type LNG tank is integrated with the hull, it is directly affected by the load generated during operation. Considering this, membrane-type LNG tanks use a double barrier structure with an additional secondary barrier to prevent LNG leakage due to damage to the primary barrier that is directly in contact with the LNG. The secondary barrier consists of a flexible secondary barrier (FSB) and a rigid secondary barrier (RSB). Among them, in the case of a flexible secondary barrier, the adhesive layer undergoes repeated contraction and expansion by receiving cold heat directly or indirectly from cryogenic liquefied gas, which causes the problem of tearing of the barrier layer made of a thin metal layer. In addition, cryogenic liquefied gas condenses the surrounding air to generate moisture, but there is a problem in that the barrier layer made of metal is corroded by this moisture, causing damage.

As an alternative, Korean Patent Publication No. 10-0457880 applied the same welding and manufacturing methods to the secondary barrier as general structures, providing simplicity of manufacturing and reduction of manufacturing man-hours. However, there is a problem that the adhesion between the aluminum foil and the reinforcing layer, adhesion at cryogenic temperatures, and flexibility regarding sealing performance are not discussed. Furthermore, there is a need to develop a secondary barrier that can simplify the process and reduce costs and process time.

Korean Patent Publication No. 10-0457880

The purpose of one aspect of the present invention is to provide a liquefied gas storage tank that has excellent adhesion between aluminum foil and the reinforcing layer, adhesion at cryogenic temperatures, and flexibility in terms of sealing performance, and can reduce costs and process time by simplifying the process. To provide a secondary barrier for use and a method for manufacturing the same.

In one aspect of the invention, aluminum foil; A first adhesive layer laminated on both sides of the aluminum foil; a second adhesive layer laminated on both sides of the first adhesive layer; and a reinforcing layer laminated on both sides of the second adhesive layer, wherein the first adhesive layer includes an elastomer, providing a secondary barrier for a liquefied gas storage tank.

In another aspect, the present invention provides a liquefied gas storage tank including a secondary barrier for the liquefied gas storage tank.

In another aspect, the present invention provides a liquefied gas transport vessel including the liquefied gas storage tank.

In another aspect, the present invention includes forming a first sheet by coating a second adhesive layer on a reinforcement layer; forming a second sheet by coating a first adhesive layer on the second adhesive layer; and laminating a first adhesive layer of a second sheet on both sides of aluminum foil, wherein the first adhesive layer includes an elastomer.

The secondary barrier for a liquefied gas storage tank according to an embodiment of the present invention has excellent adhesion between aluminum foil and the reinforcing layer, adhesion at cryogenic temperatures, and flexibility in terms of sealing performance, and is excellent in flexibility with respect to sealing performance, and is excellent in liquefaction according to an embodiment of the present invention. The manufacturing method of the secondary barrier for gas storage tanks simplifies the process and has the effect of reducing costs and process time.

Figure 1 is a structural diagram of a secondary barrier for a liquefied gas storage tank according to the prior art.
Figure 2 is a structural diagram of a secondary barrier for a liquefied gas storage tank according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

The embodiments of the present invention disclosed in the text are illustrative only for illustrative purposes, and the embodiments of the present invention may be implemented in various forms and should not be construed as limited to the embodiments described in the text. . The present invention can make various changes and take various forms, and the embodiments are not intended to limit the present invention to the specific disclosed form, but all changes, equivalents, or substitutes included in the spirit and technical scope of the present invention. It should be understood as including.

In this specification, when a part “includes” a certain component, this means that it may further include other components rather than excluding other components unless specifically stated to the contrary.

Throughout the specification, similar parts are given the same reference numerals. Throughout the specification, when a part such as a layer, membrane, region, plate, etc. is said to be “on” or “on” another part, this includes not only the case where it is directly on top of the other part, but also the case where there is another part in between. . Throughout the specification, terms such as first and second may be used to describe various components, but the components should not be limited by the terms. Terms are used only to distinguish one component from another.

Secondary barrier for liquefied gas storage tanks

“Secondary barrier for liquefied gas storage tank” is used in LNG storage tanks, and among LNG storage tanks, the membrane-type LNG storage tank has a primary barrier provided at the innermost part from the inside, that is, the part that directly touches the liquefied gas, and 1 above. A first insulation pad is provided outside the car barrier. In addition, a secondary barrier is provided outside the first insulation pad to supplement the function of the primary barrier, and finally, a second insulation pad is formed outside the secondary barrier.

Figure 1 is a structural diagram of a secondary barrier for a liquefied gas storage tank according to the prior art. In the secondary barrier (1) for a liquefied gas storage tank according to the prior art, both outer surfaces of the aluminum foil (10) are first surface treated by applying or spraying a primer (20), and are also coated with a polyamide/silane compound (30). The surface is treated, and urethane resin 40 and glass fiber 50 are laminated in that order. However, this type of secondary barrier has a complicated aluminum surface treatment method, and there is variation in flexibility depending on machine direction orientation (MDO) and transverse direction orientation (TDO), so it is attached to a right angle surface. There was a problem with the poor airtightness of the city's secondary barrier.

Accordingly, the present inventors omitted the primer primary surface treatment process for the aluminum foil and also laminated the elastomer on the aluminum foil, thereby improving the adhesion between the aluminum foil and the reinforcing layer, adhesion at cryogenic temperatures, and flexibility regarding sealing performance. The present invention was completed after discovering that there was a problem. Furthermore, the method of manufacturing a secondary barrier for a liquefied gas storage tank according to an embodiment of the present invention can also achieve the effect of reducing cost and process time by simplifying the process.

Figure 2 is a structural diagram of a secondary barrier for a liquefied gas storage tank according to an embodiment of the present invention. Exemplary embodiments of the invention include aluminum foil (aluminum foil); A first adhesive layer 200 laminated on both sides of the aluminum foil (aluminum foil); a second adhesive layer 300 laminated on both sides of the first adhesive layer 200; and a reinforcing layer 400 laminated on both sides of the second adhesive layer 300, wherein the first adhesive layer 200 includes an elastomer and provides a secondary barrier 10000 for a liquefied gas storage tank.

In one embodiment, the first adhesive layer includes at least one selected from the group consisting of polystyrene-based elastomer, polyolefin-based elastomer, polyvinyl chloride-based elastomer, polyurethane-based elastomer, polyester-based elastomer, and polyamide-based elastomer.

The elastomer of the first adhesive layer may be crosslinked using a crosslinking agent. As a crosslinking agent, a peroxide-based crosslinking agent or a sulfur-based crosslinking agent can be used. Peroxide-based crosslinking agents include, for example, peroxyketals such as 1,1-di(t-butyl peroxide) cyclohexane (PHC), dicumyl peroxide (DCP), and 2,5-dimethyl-2,5- Dialkyl peroxides such as di(t-butyl peroxide) hexane (HXA), 2,5-dimethyl-2,5-di(t-butyl peroxide) hexene-3 (HXY), and dibenzoyl peroxide (BPO) ) and diacyl peroxides, and peroxy esters such as t-butylphenyloxy benzoate. Examples of the sulfur-based crosslinking agent include powdered sulfur, precipitated sulfur, highly dispersed sulfur, surface-treated sulfur, insoluble sulphide, dimorpholine disulfide, and alkylphenol disulfide.

In one embodiment, the second adhesive layer includes at least one selected from the group consisting of acrylic resin, urethane resin, silicone resin, epoxy resin, rubber resin, and polyester resin.

In one embodiment, the reinforcing layer is made of carbon fiber, glass fiber, potassium titanate fiber, aluminum borate fiber, ceramic fiber, metal fiber, boron fiber, silicon carbide fiber, asbestos fiber, rock wool fiber, aramid fiber, polyethylene fiber, poly It includes at least one selected from the group consisting of paraphenylenebenzobisoxazole fibers, cellulose fibers, and fiber-reinforced resins.

The fiber-reinforced resin refers to a resin that is mixed with fibers to form a composite material. The fiber-reinforced resin may be a thermoplastic resin or a thermosetting resin. Thermoplastic resins include, for example, polyolefin resins, polar group-containing polyolefin resins, polymethacrylic resins such as polymethyl methacrylate resin, polyacrylic resins such as polymethyl acrylate resin, polystyrene resin, and polyvinyl alcohol-polychloride. Vinyl copolymer resin, polyvinyl acetal resin, polyvinyl butyral resin, polyvinyl formal resin, polymethyl pentene resin, maleic anhydride-styrene copolymer resin, polycarbonate resin, polyphenylene ether resin, polyether Aromatic polyether ketones such as ether ketone resin and polyether ketone resin, polyester resin, polyamide resin, polyamide-imide resin, polyimide resin, polyetherimide resin, styrene-based elastomer, polyolefin-based elastomer, and polyurethane-based elastomer. , polyester elastomer, polyamide elastomer, ionomer, aminopolyacrylamide resin, isobutylene maleic anhydride copolymer, ABS, ACS, AES, AS, ASA, MBS, ethylene-vinyl chloride copolymer, ethylene- Vinyl acetate copolymer, ethylene-vinyl acetate-vinyl chloride graft polymer, ethylene-vinyl alcohol copolymer, chlorinated polyvinyl chloride resin, chlorinated polyethylene resin, chlorinated polypropylene resin, carboxyvinyl polymer, ketone resin, amorphous copolyester Resin, norbornene resin, fluoroplastic, polytetrafluoroethylene resin, fluoroethylene polypropylene resin, PFA, polychlorofluoroethylene resin, ethylenetetrafluoroethylene copolymer, polyvinylidene fluoride resin, polyvinyl fluoride resin , polyarylate resin, thermoplastic polyimide resin, polyvinylidene chloride resin, polyvinyl chloride resin, polyvinyl acetate resin, polysulfone resin, polyparamethylstyrene resin, polyallylamine resin, polyvinyl ether resin, polyphenylene jade. Seed resin, polyphenylene sulfide (PPS) resin, polymethylpentene resin, oligoester acrylate, xylene resin, maleic acid resin, polyhydroxybutyrate resin, polysulfone resin, polylactic acid resin, polyglutamic acid resin, polycapro Lactone resin, polyethersulfone resin, polyacrylonitrile resin, styrene-acrylonitrile copolymer resin, etc. can be mentioned. Thermosetting resins include, for example, phenol resins, epoxy resins, unsaturated polyester resins, diallyl phthalate resins, melamine resins, oxetane resins, maleimide resins, urea (urea) resins, polyurethane resins, silicone resins, and benzoxazine rings. A resin having a, cyanate ester resin, etc. can be mentioned.

In one embodiment, the aluminum foil and the first adhesive layer, the first adhesive layer and the second adhesive layer, and the second adhesive layer and the reinforcement layer are chemically and physically bonded to each other. Examples of bonds include electrostatic bonds, hydrogen bonds, ionic bonds, and covalent bonds.

By adjusting the thickness ratio of the constituent layers, adhesion can be improved and flexibility can be optimized. In one embodiment, the weight ratio of the first adhesive layer and the second adhesive layer is 10:90 to 90:10.

In one embodiment, the thickness of the aluminum foil is between 65 μm and 75 μm. More specifically, the thickness of the aluminum foil is 65 μm or more, 66 μm or more, 67 μm or more, 68 μm or more, 69 μm or more, 70 μm or more; It may be 75 μm or less, 74 μm or less, 73 μm or less, 72 μm or less, 71 μm or less, and 70 μm or less, but is not limited thereto.

In one embodiment, the thickness of the first adhesive layer is 50 μm to 60 μm. More specifically, the thickness of the first adhesive layer is 50 μm or more, 51 μm or more, 52 μm or more, 53 μm or more, 54 μm or more; It may be 60 μm or less, 59 μm or less, 58 μm or less, 57 μm or less, 56 μm or less, 55 μm or less, and 54 μm or less, but is not limited thereto.

In one embodiment, the thickness of the second adhesive layer is 10 μm to 30 μm. More specifically, the thickness of the second adhesive layer is 10 μm or more, 11 μm or more, 12 μm or more, 13 μm or more, 14 μm or more, 15 μm or more, 16 μm or more, 17 μm or more, 18 μm or more, 19 μm or more. , greater than 20 μm, greater than 21 μm, greater than 22 μm, greater than 23 μm, greater than 24 μm, greater than 25 μm, greater than 26 μm, greater than 27 μm; It may be 30 μm or less, 29 μm or less, 28 μm or less, and 27 μm or less, but is not limited thereto. If the thickness of the second adhesive layer exceeds the upper limit, there is a risk of causing quality defects that protrude out of the reinforcing layer when bonded with the reinforcing layer, and if the thickness of the second adhesive layer is less than the lower limit, the mechanical bonding force with the reinforcing layer ( There is a risk that anchoring may fall.

In one embodiment, the ratio of the thickness of the first adhesive layer to the thickness of the second adhesive layer is 1:1 to 3:1. More specifically, the thickness ratio of the first adhesive layer and the second adhesive layer is 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2:1; It can be 3 : 1, 2.9 : 1, 2.8 : 1, 2.7 : 1, 2.6 : 1, 2.5 : 1, 2.4 : 1, 2.3 : 1, 2.2 : 1, 2.1 : 1, 2 : 1, but is limited to this. That is not the case.

In one embodiment, the elongation of the first adhesive layer is 100% to 500%. More specifically, the elongation of the first adhesive layer is 100% or more, 150% or more, 200% or more, 250% or more; It may be 500% or less, 450% or less, 400% or less, 350% or less, 300% or less, and 250% or less, but is not limited thereto.

In one embodiment, the tensile strength of the first adhesive layer is 50 kg/cm ² to 250 kg/cm ² . More specifically, the tensile strength of the first adhesive layer is 50 kg/cm ² or more, 100 kg/cm ² or more, 150 kg/cm ² or more; It may be 250 kg/cm ² or less, 200 kg/cm ² or less, and 150 kg/cm ² or less, but is not limited thereto.

In one embodiment, the secondary barrier for the liquefied gas storage tank is a Flexible Secondary Barrier (FSB). The space between the first insulation pad and the first insulation pad is sealed by the flexible secondary barrier.

Liquefied gas storage tank and liquefied gas transport vessel

In other exemplary embodiments of the present invention, a liquefied gas storage tank is provided, comprising a secondary barrier for the liquefied gas storage tank.

In other exemplary embodiments of the present invention, a liquefied gas transport vessel is provided, including the liquefied gas storage tank.

In other exemplary embodiments of the present invention, a liquefied gas refrigeration system including the liquefied gas storage tank is provided.

Manufacturing method of secondary barrier for liquefied gas storage tank

Other exemplary embodiments of the invention include forming a first sheet by coating a second adhesive layer on the reinforcing layer; forming a second sheet by coating a first adhesive layer on the second adhesive layer; and laminating a first adhesive layer of a second sheet on both sides of aluminum foil, wherein the first adhesive layer includes an elastomer.

The present inventors omitted the primer primary surface treatment process for the aluminum foil and also laminated the elastomer on the aluminum foil, thereby improving the adhesion between the aluminum foil and the reinforcing layer, adhesion at cryogenic temperatures, and flexibility regarding sealing performance. With this knowledge, the present invention was completed. Furthermore, the method of manufacturing a secondary barrier for a liquefied gas storage tank according to an embodiment of the present invention can also achieve the effect of reducing cost and process time by simplifying the process.

In order to increase the adhesion of the secondary barrier for the liquefied gas storage tank, the secondary barrier for the liquefied gas storage tank with mechanical anchoring can be manufactured by performing roll lamination with a thermal lamination machine.

In one embodiment, the lamination is performed at a temperature of 120°C to 200°C and a speed of 1 m/min to 5 m/min. More specifically, the lamination temperature is 120°C or higher, 130°C or higher, 140°C or higher; It may be 200°C or lower, 190°C or lower, 180°C or lower, 170°C or lower, 160°C or lower, 150°C or lower, and 140°C or lower, but is not limited thereto. More specifically, the lamination speed is 1 m/min or more, 2 m/min or more, 3 m/min or more; It may be 5 m/min or less, 4 m/min or less, or 3 m/min or less, but is not limited thereto.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments so that those skilled in the art can easily practice it. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

{Example}

<Manufacturing example> Manufacturing of secondary barriers for liquefied gas storage tanks

1. Example 1

A first sheet was formed by coating a second adhesive layer made of urethane resin on a reinforcing layer made of glass fiber. A first adhesive layer made of polyamide-based elastomer was coated on the second adhesive layer to form a second sheet. The first adhesive layer of the second sheet was laminated on both sides of the aluminum foil using a thermal lamination machine at a temperature of 140°C and a speed of 3 m/min. Finally, a secondary barrier for a liquefied gas storage tank according to Example 1 was obtained in which the first adhesive layer had a thickness of 54 μm and the second adhesive layer had a thickness of 27 μm.

2. Example 2

A secondary barrier for a liquefied gas storage tank according to Example 2 was manufactured using the same method as Example 1, except that the thickness ratio of the first adhesive layer and the second adhesive layer was 3:1.

3. Comparative Example 1

Comparative Example 1 was prepared using the same method as Example 1, except that the stacking order was 'reinforcement layer made of glass fiber/adhesive layer made of urethane resin/aluminum foil/adhesive layer made of urethane resin/reinforcement layer made of glass fiber'. A secondary barrier for a liquefied gas storage tank was manufactured.

4. Comparative Example 2

The same method as Example 1 was used except that the stacking order was 'reinforcement layer made of glass fiber/adhesive layer made of polyamide-based elastomer/aluminum foil/adhesive layer made of polyamide-based elastomer/reinforcement layer made of glass fiber'. A secondary barrier for a liquefied gas storage tank according to Comparative Example 2 was manufactured.

5. Comparative Example 3

The stacking order is 'reinforcement layer made of glass fiber/adhesive layer made of urethane resin/adhesive layer made of polyamide elastomer/aluminum foil/adhesive layer made of polyamide elastomer/adhesive layer made of urethane resin/reinforcement layer made of glass fiber'. A secondary barrier for a liquefied gas storage tank according to Comparative Example 2 was manufactured using the same method as Example 1, except that. More specifically, an adhesive layer made of a lethane-based resin and an adhesive layer made of a polyamide-based elastomer were coated on the reinforcement layer using a T-die coating method, and then laminated on both sides of the aluminum foil using a thermal lamination machine.

6. Comparative Example 4

A secondary barrier for a liquefied gas storage tank according to Comparative Example 4 was manufactured using the same method as Example 1, except that the thickness ratio of the first adhesive layer and the second adhesive layer was 6:1.

<Experimental Example 1> Flexibility evaluation

1. Evaluation method

The flexibility of the secondary barriers of Example 1 and Comparative Examples 1 to 3 was evaluated. More specifically, a specimen of the same size was produced for each sample (2.5 cm × 30 cm) and placed in close contact with a cylindrical test rod with a radius of R mm. The stages were divided according to the degree of adhesion between the test rod and the specimen (4 stages). It was checked whether damage occurred to the specimen when bent 180° in close contact with the test rod. The minimum R value at which no damage occurred to the specimen was measured. The results are shown in Table 1.

division Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 R value (mm) 8 12 8 12

2. Evaluation results

From Table 1, it can be seen that the flexibility of the secondary barrier for the liquefied gas storage tank according to Example 1 is excellent.

<Experimental Example 2> Evaluation of interlayer peeling and peeling strength

1. Evaluation method

Interlayer peeling and peeling strength were evaluated for the secondary barriers of Example 1 and Comparative Examples 1 to 3. More specifically, interlayer peeling was performed by peeling off the layers of the specimen with MEK (Methyl ethyl ketone) solvent, then holding the end and peeling off the part that was not peeled off with the solvent to check whether there was interlayer peeling (◎: Excellent, ○ : Good, △: Average, ×: Unsatisfactory). Peel strength was measured by performing a 180° Peel Test on the specimen. The results are shown in Table 2.

division Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 delamination ◎ ◎ ◎ △ Peel Strength (kgf/in) 25℃ 6.38 0.79 1.43 1.10 -170℃ 6.66 0.76 1.35 1.44

2. Evaluation results

From Table 2, it can be seen that the interlayer peeling test results of the secondary barrier for the liquefied gas storage tank according to Example 1 are excellent, and the peeling strength is significantly high.

<Experimental Example 3> Peel strength evaluation according to the thickness ratio of the first adhesive layer and the second adhesive layer

1. Evaluation method

Peel strength was evaluated for the secondary barriers of Example 1, Example 2, and Comparative Example 4. More specifically, peel strength was measured by performing a 180° Peel Test on the specimen. The results are shown in Table 3.

division Example 1 Example 2 Comparative Example 4 Peel strength (kgf/in) (25℃) 6.38 5.60 5.07

2. Evaluation results

From Table 3, it can be seen that the peeling strength of the secondary barrier for the liquefied gas storage tank according to Example 1 and Example 2 is significantly high.

Although exemplary embodiments of the present invention have been described above in relation to the above-mentioned preferred embodiments, various modifications and variations can be made without departing from the gist and scope of the invention. Accordingly, the appended claims will include such modifications and variations as long as they fall within the spirit of the present invention.

1: Conventional secondary barrier 10: Aluminum foil
20: Primer 30: Polyamide/silane compound
40: Urethane resin 50: Glass fiber
100: aluminum foil 200: first adhesive layer
300: second adhesive layer 400: reinforcement layer
10000: Secondary barrier for liquefied gas storage tank

Claims (13)

aluminum foil;
A first adhesive layer laminated on both sides of the aluminum foil;
a second adhesive layer laminated on both sides of the first adhesive layer; and
It includes a reinforcing layer laminated on both sides of the second adhesive layer,
The first adhesive layer includes a polyamide-based elastomer,
The second adhesive layer includes a urethane-based resin,
The reinforcing layer includes glass fiber,
A secondary barrier for a liquefied gas storage tank, wherein the thickness ratio of the first adhesive layer and the second adhesive layer is 2:1 to 3:1. delete delete delete According to paragraph 1,
A secondary barrier for a liquefied gas storage tank, wherein the aluminum foil has a thickness of 65 μm to 75 μm. According to paragraph 1,
A secondary barrier for a liquefied gas storage tank, wherein the first adhesive layer has a thickness of 50 μm to 60 μm. According to paragraph 1,
A secondary barrier for a liquefied gas storage tank, wherein the second adhesive layer has a thickness of 10 μm to 30 μm. According to paragraph 1,
The secondary barrier for the liquefied gas storage tank is a flexible secondary barrier (FSB). A liquefied gas storage tank comprising a secondary barrier for the liquefied gas storage tank according to any one of claims 1 and 5 to 8. A liquefied gas transport vessel comprising a liquefied gas storage tank according to claim 9. forming a first sheet by coating a second adhesive layer on the reinforcement layer;
forming a second sheet by coating a first adhesive layer on the second adhesive layer; and
It includes laminating a first adhesive layer of a second sheet on both sides of aluminum foil,
It does not include a primer surface treatment process for the aluminum foil,
The method of manufacturing a secondary barrier for a liquefied gas storage tank according to any one of claims 1 and 5 to 8, wherein the first adhesive layer includes a polyamide-based elastomer. According to clause 11,
A method of manufacturing a secondary barrier for a liquefied gas storage tank, wherein the lamination is performed at a temperature of 120°C to 200°C and a speed of 1m/min to 5m/min.
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