Epoxy resin composition for LNG storage tank supporting seat and preparation method

Abstract

The invention discloses an epoxy resin composition for an LNG (Liquefied Natural Gas) storage tank supporting seat and a preparation method thereof, and the epoxy resin composition is prepared from the following raw materials in parts by weight: 40 parts of bisphenol A epoxy resin, 4-15 parts of tetraglycidyl diaminodiphenyl methane, 7-22 parts of o-cresol formaldehyde epoxy resin, 4-10 parts of a latent curing agent, 0.2-1 part of an accelerant, 1.5-5 parts of hollow light filler, 0.15-0.5 part of a coupling agent and 0.5-5 parts of a toughening agent. And 1.5 to 3 parts of a surfactant. The epoxy resin composition disclosed by the invention has relatively high compression strength, bending strength and impact strength and relatively low heat conductivity coefficient at room temperature and minus 163 DEG C, can resist the ultimate temperature of 300 DEG C or above within 10 minutes, and is an excellent polymer composite material for manufacturing the LNG storage tank supporting seat.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of resin-based composite materials, and particularly relates to an epoxy resin composition for a LNG storage tank support seat and a preparation method. BACKGROUND

[0002] In recent years, with the accelerated adjustment of the world energy supply and demand pattern, the demand for liquefied energy transportation and storage is also increasing rapidly, and the scale of transportation ships represented by LNG ships is also expanding. The LNG storage tank stores low-temperature LNG liquid at -163 DEG C inside, and the tank body support material needs to have the following functions: (1) high mechanical strength and stable mechanical properties at extremely low temperature of -163 DEG C to ensure the safety of long-term operation of the storage tank; (2) low thermal conductivity to effectively reduce heat transfer; (3) low density to reduce the overall weight of the storage tank system. Based on this, resin-based composite materials have become an ideal choice for tank body support materials due to their lightweight, high strength, and low thermal conductivity.

[0003] On the other hand, for some LNG storage tanks, especially double-layer LNG storage tanks, after the internal support seat is installed, welding operation needs to be performed on the outside. The heat generated by welding will be transferred to the composite material support seat, causing local damage. During the welding process, the composite material support seat needs to withstand high temperature of 350 DEG C for a short time.

[0004] However, the existing materials cannot meet the above requirements at the same time.

[0005] Patent document CN204099891U discloses an LNG low-temperature storage tank, which adopts a double-layer tank wall structure, the tank body is provided with an inner barrel and an outer barrel, a support part is arranged between the inner barrel and the outer barrel, and the support part is a bakelite support block. However, the mechanical properties of bakelite material are low, and the support structure has been changed to composite material at present.

[0006] Patent document CN207065067U discloses an LNG horizontal low-temperature storage tank, which comprises an inner tank body, an outer tank body and an intermediate layer, the intermediate layer is vacuumized and filled with pearl sand thermal insulation material, and the inner tank body is fixed by eight uniformly arranged glass fiber reinforced plastic supports. However, the conventional glass fiber reinforced plastic structure has high thermal conductivity, the mechanical properties decrease at low temperature of -163 DEG C, and the high temperature resistance is weak.

[0007] Patent document CN117261374B discloses an LNG ship composite material type laminated wood and a preparation method thereof. The material can have good mechanical properties and thermal insulation properties at -163 DEG C, but the method can only be used for processing and preparing block-shaped LNG storage tank support seats, and is not suitable for tubular support seats used for double-layer LNG storage tanks. At the same time, the document does not mention the high temperature resistance. SUMMARY

[0008] The present application aims to provide an epoxy resin composition for LNG storage tank support seat and a preparation method, a prepreg prepared from the epoxy resin composition has higher mechanical properties at -163 DEG C, lower thermal conductivity, higher temperature resistance, and can withstand high temperature of 300-360 DEG C for a short time, and the prepreg is used for preparing LNG storage tank support seat.

[0009] In order to achieve the above-mentioned purpose, the technical scheme of the present application is as follows.

[0010] The present application is an epoxy resin composition for LNG storage tank support seat, which is prepared from the following raw materials by weight: 40 parts of bisphenol A epoxy resin, 4-15 parts of tetraglycidyl diamino diphenyl methane, 7-22 parts of o-cresol formaldehyde epoxy resin, 4-10 parts of latent curing agent, 0.2-1 part of accelerator, 1.5-5 parts of hollow lightweight filler, 0.15-0.5 part of coupling agent, 0.5-5 parts of toughening agent, and 1.5-3 parts of surfactant. The bisphenol A epoxy resin is a liquid bisphenol A epoxy resin with an epoxy value of 0.50-0.56 eq / 100 g, an active ingredient content of ≥99% wt, and a viscosity of 7000-13000 mPa·s at 25 DEG C; for example, E-51 type bisphenol A epoxy resin, preferably at least one of NPEL-128 of Nanya, DER-330 of Dow Chemical, or E44 of Shandong De Yuan; The tetraglycidyl diamino diphenyl methane is a liquid 4,4-diaminodiphenyl methane tetraglycidyl amine with an epoxy value of 0.90-1.05 eq / 100 g and a viscosity of 1500-3000 mPa·s at 25 DEG C, CAS No.: 28768-32-3; for example, SW-80 of Syltech, AG-80 of Shanghai Huayi; The o-cresol formaldehyde epoxy resin is a solid o-cresol type phenolic aldehyde epoxy resin with a functionality of 5-6 and an epoxy equivalent weight of 210-230 g / eq, preferably one or two of YECN-220 of Balin Petrochemical, Epikote 681 of Honsen, and EOCN6850 of Jiasengde; The latent curing agent is an epoxy propane modified dicyandiamide, for example, MD-02 of Wenzhou Qingming Chemical Industry; The accelerator is a bifunctional urea accelerator, for example, TJ-UR301 of Taigi New Material, UR-500 of Tianjiang New Material; The hollow lightweight filler is a hollow glass microsphere, for example, one or more of HS42, HL42, and HL46 of Saint-Gobain; The coupling agent is gamma-glycidyl ether oxypropyl trimethoxysilane, for example, KBE-403 of Shin-Etsu Chemical, Z-6040 of Dow; The toughening agent is a core-shell particle toughening agent, for example Suzhou Saipu CSR-800; The surface active agent is branched isotridecanol polyether, for example Wil Chemical AEO-9P; it is a non-ionic surface active agent, has excellent wetting and penetration, can improve the wetting performance of resin in the pre-impregnated material impregnation process, and avoids dry yarn of fibers.

[0011] The preparation method of the epoxy resin composition for the LNG storage tank support seat comprises the following steps: S1, half of the bisphenol A epoxy resin is uniformly mixed with the latent curing agent and the accelerator to obtain a mixture A; S2, the other half of the bisphenol A epoxy resin is added into a reaction kettle, the temperature is raised to 60-80 DEG C, the tetraglycidyl diamino diphenyl methane is added and uniformly mixed, and the temperature is kept for 20-30 min; then the temperature is raised to 80-100 DEG C, the o-cresol formaldehyde epoxy resin is added and uniformly mixed, and the temperature is kept for 30-60 min to obtain a mixture B; S3, the coupling agent is dissolved in 80% ethanol solution at a mass ratio of 1%-5%, the hollow lightweight filler is added into the solution, ultrasonic dispersion is carried out at a temperature of 55-65 DEG C for 50-80 min, suction filtration is carried out, drying is carried out at 100-120 DEG C, and sieving is carried out to obtain the modified hollow lightweight filler; S4, the surface active agent, the mixture A, the modified hollow lightweight filler and the toughening agent are added into the mixture B, and stirring is carried out until the system is uniform, so that the epoxy resin composition is obtained.

[0012] The application further provides a preparation method of the LNG storage tank support seat, which adopts the epoxy resin composition, and comprises the following steps: D1, the epoxy resin composition is coated into a resin glue film at a temperature of 60-80 DEG C, and then the resin glue film is impregnated with glass fabric on a pre-impregnation machine at a temperature of 80-100 DEG C to obtain a pre-impregnated material (the resin glue film is extruded into the gap of the glass fabric under heating and then solidified to form an integrated body); D2, the mold core is heated to 145-155 DEG C, the pre-impregnated material is rolled onto the core mold at a rolling pressure of 80-100 N / cm and a rolling speed of 2-5 m / min, and a tubular blank with a specified thickness is rolled; D3, the tubular blank is kept at a temperature of 115-125 DEG C for 2-3 h, kept at a temperature of 135-145 DEG C for 2-3 h, and kept at a temperature of 170-180 DEG C for 4-5 h; then the temperature is slowly reduced to room temperature at a speed of 0.2-0.5 DEG C / min; after demolding, the tubular structure is machined to obtain a tubular structural member as a double-layer LNG storage tank support seat.

[0013] Compared with the prior art, the application has the following beneficial effects: The preferred liquid bisphenol A epoxy resin of this invention has low viscosity and good flowability. Adding other formulation materials to it eliminates the need for additional solvents, simplifying operation. Furthermore, this liquid bisphenol A epoxy resin exhibits high mechanical properties and toughness, maintaining high mechanical properties even at extremely low temperatures of -170°C. The tetraglycidyl diaminodiphenylmethane molecule contains four epoxy groups, forming a highly cross-linked three-dimensional network structure after curing, significantly improving mechanical and heat resistance properties. In the o-cresolaldehyde epoxy resin molecule, an average of one epoxy group is present for every 1.2–1.4 benzene rings. The rigid benzene rings in the molecule have a high proportion of density, providing 2.5 times the number of cross-linking points during curing, forming a highly cross-linked three-dimensional structure. This invention optimizes the blending ratio of the three epoxy resins mentioned above. Bisphenol A type epoxy resin provides basic toughness, while tetraglycidyl diaminodiphenylmethane and o-cresol epoxy resin synergistically improve crosslinking density and structural rigidity. It can exhibit good mechanical properties in a temperature range of -170℃ to 150℃, as well as excellent extreme high temperature resistance, and can withstand high temperatures up to 350℃ without structural damage.

[0014] This invention preferably uses propylene oxide-modified dicyandiamide as a curing agent, which maintains good room temperature latency and allows the prepared prepreg to be stored at room temperature for more than 30 days. It has high compatibility with epoxy resin and is easy to disperse evenly. Its curing speed is relatively fast, and it can complete the initial curing during the rolling process at 150°C. After completion, it is post-cured in an oven to achieve the best performance of the product.

[0015] This invention preferably uses a bifunctional urea-based accelerator, which decomposes upon heating into dimethylamine and isocyanate. The dimethylamine reacts with epoxy groups to form a tertiary amine, further catalyzing the crosslinking reaction between the epoxy groups and the propylene oxide-modified dicyandiamide curing agent. Its bifunctional structure enhances molecular polarity, improves compatibility with epoxy resins, and lowers the curing reaction initiation temperature from 150°C to 120-130°C. Furthermore, this accelerator is solid at room temperature, does not react with epoxy resins, and has no impact on the storage period of the prepreg at room temperature.

[0016] The hollow glass microspheres preferred in this invention form uniformly dispersed "hollow units" within the matrix, increasing the thermal resistance path and reducing the thermal conductivity, resulting in an LNG storage tank support with an even lower thermal conductivity. The methoxy-Si(OCH3)3 at one end of the γ-glycidyl etheroxypropyltrimethoxysilane coupling agent molecule can undergo a hydrolytic condensation reaction with the silanol groups (-Si-OH) on the surface of the glass microspheres, forming a strong Si-O-Si covalent bond, firmly grafting it onto the microsphere surface. The epoxy group at the other end, during the curing process, can undergo a ring-opening polymerization reaction with the active groups of the resin matrix, forming chemical bonds and avoiding interfacial defects. This allows the product to achieve a low thermal conductivity without significantly reducing compressive strength, flexural strength, and impact toughness. Core-shell particle toughening agents consist of a softer inner "core" and a harder outer "shell." When added to a resin matrix, the soft shells of the core-shell particles dispersed in the matrix act as stress concentration points, undergoing plastic deformation and directly absorbing energy. Simultaneously, they induce numerous microcracks and shear yield bands in the surrounding matrix, preventing the rapid propagation of a single main crack. When subjected to external forces and impacts, the interfaces between the hollow glass microspheres and the resin matrix, the core and shell of the core-shell particles, and the shell and resin matrix can debond under stress, forming microvoids. These voids can blunt the crack tip, preventing crack propagation. When the crack extends to the hollow glass microspheres and core-shell particles, it may deflect, bypass, or bifurcate, prolonging the crack propagation path and consuming more energy.

[0017] Therefore, the epoxy resin composition of the present invention has high compressive strength, flexural strength, and impact strength at room temperature and -163°C, low thermal conductivity, and an extreme temperature resistance of over 300°C in 10 minutes, making it an excellent polymer composite material for manufacturing LNG storage tank support bases. Attached Figure Description

[0018] Figure 1 This invention relates to a double-layer LNG storage tank support.

[0019] Figure 2 This is a photograph of the sample from Example 5 after baking at 350°C for 10 minutes. Detailed Implementation

[0020] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0021] Example 1 An epoxy resin composition for an LNG storage tank support base comprises the following raw materials weighed by weight: 40 parts of liquid bisphenol A epoxy resin (Nanya NPEL-128), 4.6 parts of tetraglycidyl diaminodiphenylmethane (Shanghai Huayi AG-80), 7.7 parts of o-cresol epoxy resin (Baling Petrochemical YECN-220), 5.4 parts of propylene oxide modified dicyandiamide curing agent (Wenzhou Qingming Chemical MD-02), 0.4 parts of bifunctional highly active urea accelerator (Taiji New Materials TJ-UR301), 1.5 parts of hollow glass microspheres (Shenglait HS42), 0.15 parts of γ-glycidyl etheroxypropyltrimethoxysilane (Shin-Etsu Chemical KBE-403), 0.8 parts of toughening agent (Suzhou Saipu CSR-800), and 1.9 parts of surfactant (Zhiweier Chemical AEO-9P).

[0022] The method for preparing this epoxy resin composition includes the following steps: S1, Mix half of the bisphenol A epoxy resin with a latent curing agent and an accelerator to obtain mixture A; S2, add the other half of the bisphenol A epoxy resin to the reactor, raise the temperature to 80°C; add tetraglycidyl diaminodiphenylmethane, mix well, and keep warm for 30 min; then raise the temperature to 90°C, add o-cresol epoxy resin, mix well, and keep warm for 60 min to obtain mixture B; S3, the coupling agent is dissolved in 80% ethanol solution at a mass ratio of 2%, and the hollow lightweight filler is added to the solution. The mixture is ultrasonically dispersed at 60°C for 60 min, filtered, dried at 100°C for 6 h, and sieved to obtain the modified hollow lightweight filler. S4, add surfactant, mixture A, modified hollow lightweight filler and toughening agent to mixture B in sequence, stir for 30 min until the system is uniform, and the epoxy resin composition is obtained.

[0023] Example 2 An epoxy resin composition for LNG storage tank support base comprises the following raw materials weighed by weight: 40 parts of liquid bisphenol A epoxy resin (Nanya NPEL-128), 7.2 parts of tetraglycidyl diaminodiphenylmethane (Shanghai Huayi AG-80), 13 parts of o-cresolaldehyde epoxy resin (Baling Petrochemical YECN-220), 6.2 parts of propylene oxide modified dicyandiamide curing agent (Wenzhou Qingming Chemical MD-02), 0.5 parts of bifunctional highly active urea accelerator (Taiji New Materials TJ-UR301), 1.8 parts of hollow glass microspheres (Shenglait HS42), 0.18 parts of γ-glycidyl etheroxypropyltrimethoxysilane (Shin-Etsu Chemical KBE-403), 0.9 parts of toughening agent (Suzhou Saipu CSR-800), and 2.2 parts of surfactant (Zhiweier Chemical AEO-9P).

[0024] The preparation method of this epoxy resin composition is the same as in Example 1.

[0025] Example 3 An epoxy resin composition for LNG storage tank support base comprises the following raw materials weighed by weight: 40 parts of liquid bisphenol A epoxy resin (Nanya NPEL-128), 13.3 parts of tetraglycidyl diaminodiphenylmethane (Shanghai Huayi AG-80), 22 parts of o-cresolaldehyde epoxy resin (Baling Petrochemical YECN-220), 7.8 parts of propylene oxide modified dicyandiamide curing agent (Wenzhou Qingming Chemical MD-02), 0.54 parts of bifunctional highly active urea accelerator (Taiji New Materials TJ-UR301), 2.1 parts of hollow glass microspheres (Shenglait HL42), 0.21 parts of γ-glycidyl etheroxypropyltrimethoxysilane (Shin-Etsu Chemical KBE-403), 1.15 parts of toughening agent (Suzhou Saipu CSR-800), and 2.7 parts of surfactant (Zhiweier Chemical AEO-9P).

[0026] The preparation method of this epoxy resin composition is the same as in Example 1.

[0027] Example 4 An epoxy resin composition for LNG storage tank support base comprises the following raw materials weighed by weight: 40 parts of liquid bisphenol A epoxy resin (Dow Chemical DER-330), 10 parts of tetraglycidyl diaminodiphenylmethane (Selve SW-80), 18 parts of o-cresolaldehyde epoxy resin (Jiashengde EOCN6850), 7 parts of propylene oxide modified dicyandiamide curing agent (Wenzhou Qingming Chemical MD-02), 0.5 parts of bifunctional highly active urea accelerator (Taiji New Materials TJ-UR301), 2 parts of hollow glass microspheres (Shenglait HL42), 0.2 parts of γ-glycidyl etheroxypropyltrimethoxysilane (Dow Z-6040), 3 parts of toughening agent (Suzhou Saipu CSR-800), and 2.5 parts of surfactant (Zhiweier Chemical AEO-9P).

[0028] The preparation method of this epoxy resin composition is the same as in Example 1.

[0029] Example 5 An epoxy resin composition for LNG storage tank support base comprises the following raw materials weighed by weight: 40 parts of liquid bisphenol A epoxy resin (Dow Chemical DER-330), 10 parts of tetraglycidyl diaminodiphenylmethane (Selve SW-80), 18 parts of o-cresolaldehyde epoxy resin (Jiashengde EOCN6850), 7 parts of propylene oxide modified dicyandiamide curing agent (Wenzhou Qingming Chemical MD-02), 0.5 parts of bifunctional highly active urea accelerator (Taiji New Materials TJ-UR301), 3.5 parts of hollow glass microspheres (Shenglait HL42), 0.35 parts of γ-glycidyl etheroxypropyltrimethoxysilane (Dow Z-6040), 3 parts of toughening agent (Suzhou Saipu CSR-800), and 2.5 parts of surfactant (Zhiweier Chemical AEO-9P).

[0030] The preparation method of this epoxy resin composition is the same as in Example 1.

[0031] Example 6 An epoxy resin composition for LNG storage tank support base comprises the following raw materials weighed by weight: 40 parts of liquid bisphenol A epoxy resin (Shandong Deyuan E44), 10 parts of tetraglycidyl diaminodiphenylmethane (Selve SW-80), 18 parts of o-cresolaldehyde epoxy resin (Jiashengde EOCN6850), 7 parts of propylene oxide modified dicyandiamide curing agent (Wenzhou Qingming Chemical MD-02), 0.5 parts of bifunctional highly active urea accelerator (Taiji New Material TJ-UR301), 5 parts of hollow glass microspheres (Shenglait HL42), 0.5 parts of γ-glycidyl etheroxypropyltrimethoxysilane (Dow Z-6040), 3 parts of toughening agent (Suzhou Saipu CSR-800), and 2.5 parts of surfactant (Zhiweier Chemical AEO-9P).

[0032] The preparation method of this epoxy resin composition is the same as in Example 1.

[0033] Test Experiment Example The epoxy resin compositions of Examples 1 to 6 were coated at 70°C on a coating machine to form resin films, and then impregnated with glass fiber fabric at 90°C on a prepreg machine to obtain prepregs (see step D1 of Application Example 7). The prepregs were laid in a specified number of layers and cured to obtain composite laminates. The composite laminates were then cut into dimensions specified by the test method to obtain samples, and the mechanical properties of the cured laminates were tested.

[0034] The compressive strength was determined according to the specifications in GB / T 1448-2005 "Test Method for Compression Properties of Fiber Reinforced Plastics". The flexural strength was determined according to the specifications in GB / T 1449-2005 "Test Method for Flexural Properties of Fiber Reinforced Plastics". The impact strength was determined according to the specifications in GB / T 1451-2005 "Test Method for Impact Toughness of Simply Supported Beams of Fiber Reinforced Plastics". The thermal conductivity was determined according to the specifications in GB / T 3139-2005 "Test Method for Thermal Conductivity of Fiber Reinforced Plastics". The 10-minute extreme temperature resistance test method was as follows: a sample block with dimensions of 50mm × 30mm × 10mm was placed in a high-temperature test chamber, heated to the specified temperature at a heating rate of 2℃ / min, held at that temperature for 10 minutes, and then the sample block was removed and observed for any damage such as scorching, cracking, or deformation. The results are shown in Table 1.

[0035] Table 1. Test results of epoxy resin laminates from Examples 1-6 As shown in Table 1, the laminate of Example 1 has high compressive strength, flexural strength, and impact strength at room temperature and -163°C, low thermal conductivity, and a maximum temperature resistance of 300°C in 10 minutes. In Examples 2-3, the proportion of tetraglycidyl diaminodiphenylmethane and o-cresol epoxy resin was increased, which enhanced the compressive strength and flexural strength at room temperature, and the maximum temperature resistance in 10 minutes reached 330°C and 360°C, respectively. However, the toughness of the material decreased, and the compressive strength and flexural strength at -163°C were slightly lower than those of Example 1. The impact strength at room temperature and -163°C was reduced, while the thermal conductivity remained basically the same.

[0036] Compared with Example 3, Example 4 appropriately reduced the proportion of tetraglycidyl diaminodiphenylmethane and o-cresol epoxy resin, and increased the proportion of core-shell particle toughening agent. The material toughness was improved, and the compressive strength, flexural strength and impact strength all reached a relatively good level. The extreme temperature resistance was 350℃ in 10 minutes.

[0037] Compared with Example 4, Example 5 increased the proportion of hollow glass microspheres, and the material's compressive strength, flexural strength, and impact strength all reached a relatively good level. The extreme temperature resistance was 350℃ in 10 minutes, and the thermal conductivity was reduced to 0.296W / (m·K).

[0038] Compared with Example 4, Example 6 further increases the proportion of hollow glass microspheres, achieves a maximum temperature resistance of 350℃ in 10 minutes, reduces the thermal conductivity to 0.275W / (m·K), and slightly reduces the compressive strength, flexural strength, and impact strength, but still maintains a high level.

[0039] Application Example 7 The preparation of LNG storage tank support bases using the epoxy resin compositions of Examples 1-6 includes the following steps: D1 involves coating an epoxy resin composition at 70°C on a coating machine to form a resin film, which is then conveyed to a prepreg machine. Under the action of heating rollers to 90°C and roller extrusion, the resin film is impregnated with fiberglass fabric to obtain a prepreg (the resin film is squeezed into the gaps of the fiberglass fabric under heating and then solidifies to form a whole). After cooling by cooling plates and cooling air, the prepreg is obtained (referred to as a two-step hot-melt prepreg). D2 uses an automatic tube rolling machine to heat the mold core to 150℃ and roll the prepreg onto the mold core with a rolling pressure of 80N / cm and a rolling speed of 3m / min to roll it into a tubular blank of a specified thickness. D3. The tubular blank, together with the mold core, is placed in an oven and kept at 120°C for 2 hours, 140°C for 2 hours, and 180°C for 4 hours. Then, it is cooled to room temperature at a rate of 0.5°C / min. After demolding, it is machined to obtain a tubular structural component, which serves as a support for a double-layer LNG storage tank.

Claims

1. An epoxy resin composition for LNG storage tank support, characterized in that, It is made from the following raw materials in parts by weight: 40 parts bisphenol A epoxy resin, 4-15 parts tetraglycidyl diaminodiphenylmethane, 7-22 parts o-cresol epoxy resin, 4-10 parts latent curing agent, 0.2-1 parts accelerator, 1.5-5 parts hollow lightweight filler, 0.15-0.5 parts coupling agent, 0.5-5 parts toughening agent, and 1.5-3 parts surfactant.

2. The epoxy resin composition according to claim 1, characterized in that, The bisphenol A epoxy resin is a liquid bisphenol A epoxy resin with an epoxy value of 0.50 to 0.56 eq / 100g, an effective ingredient content of ≥99%wt, and a viscosity of 7000 to 13000 mPa·s at 25℃.

3. The epoxy resin composition according to claim 1, characterized in that, The tetraglycidyl diaminodiphenylmethane is a liquid 4,4-diaminodiphenylmethane tetraglycidylamine with an epoxy value of 0.90-1.05 eq / 100g and a viscosity of 1500-3000 mPa·s at 25°C.

4. The epoxy resin composition according to claim 1, characterized in that, The o-cresol epoxy resin is a solid o-cresol-type phenolic epoxy resin with a functionality of 5-6 and an epoxy equivalent of 210-230 g / eq.

5. The epoxy resin composition according to claim 1, characterized in that, The latent curing agent is propylene oxide-modified dicyandiamide.

6. The epoxy resin composition according to claim 1, characterized in that, The accelerator is a bifunctional urea accelerator.

7. The epoxy resin composition according to claim 1, characterized in that, The hollow lightweight filler is hollow glass microspheres; the coupling agent is γ-glycidoxypropyltrimethoxysilane.

8. The epoxy resin composition according to claim 1, characterized in that, The toughening agent is a core-shell particle toughening agent; the surfactant is branched isotridecyl alcohol polyether.

9. The method for preparing the epoxy resin composition for LNG storage tank support according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1, half of the bisphenol A epoxy resin is mixed evenly with the latent curing agent and accelerator to obtain mixture A; S2, add the other half of the bisphenol A epoxy resin to the reactor, raise the temperature to 60-80°C; add the tetraglycidyl diaminodiphenylmethane, mix evenly, and keep warm for 20-30 minutes; then raise the temperature to 80-100°C, add the o-cresol epoxy resin, mix evenly, and keep warm for 30-60 minutes to obtain mixture B; S3, dissolve the coupling agent in an 80% ethanol solution at a mass ratio of 1% to 5%, then add the hollow lightweight filler to the solution, disperse it ultrasonically at a temperature of 55 to 65°C, filter it, dry it at 100 to 120°C, and sieve it to obtain the modified hollow lightweight filler. S4, add the surfactant, mixture A, modified hollow lightweight filler and toughening agent to the mixture B, and stir until the system is uniform to obtain the epoxy resin composition.

10. A method for preparing an LNG storage tank support, using an epoxy resin composition as described in any one of claims 1 to 8, comprising the following steps: D1, the epoxy resin composition is coated at a temperature of 60-80°C to form a resin film, and then impregnated with glass fiber fabric at 80-100°C on a prepreg machine to obtain a prepreg. D2, heat the mold core to 145-155℃, and roll the prepreg onto the mold core with a rolling pressure of 80-100N / cm and a rolling speed of 2-5m / min to form a tubular blank of a specified thickness; D3. The tubular blank, together with the mold core, is kept at 115-125°C for 2-3 hours, 135-145°C for 2-3 hours, and 170-180°C for 4-5 hours; then slowly cooled to room temperature at a rate of 0.2-0.5°C / min; after demolding, it is machined to obtain a tubular structural component, which serves as a support for a double-layer LNG storage tank.

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