Thixotropic unsaturated polyester resin with good storage stability and preparation method thereof

Abstract

The invention discloses thixotropic unsaturated polyester resin with good storage stability and a preparation method of the thixotropic unsaturated polyester resin, and belongs to the technical field of unsaturated polyester resin. The unsaturated polyester resin composition is prepared from the following raw materials in parts by weight: 95 to 99 parts of unsaturated polyester resin, 0.475 to 0.693 part of fumed silica, 0.024 to 0.0624 part of a thixotropic additive, 0.006 to 0.011 part of a polymerization inhibitor, 0.029 to 0.0832 part of an anti-settling agent, 0.92 to 1.61 part of a de-foaming agent and 20 to 35 parts of a cross-linking agent. According to the method, all the components are added and mixed step by step, so that uniform dispersion of all the components in a resin system is ensured. Mutual interference among all the components can be effectively avoided in a step-by-step adding mode, and the effect of each additive can be fully exerted. According to the invention, the stability of the system at high temperature and room temperature is improved, and the performance reduction of the resin in long-term storage or long-distance transportation is avoided.

Description

Technical Field

[0001] The invention relates to a thixotropic unsaturated polyester resin with good storage stability and a preparation method thereof, belonging to the technical field of unsaturated resins. Background Art

[0002] Thixotropic resin is a special resin with pseudoplastic flow characteristics. When subjected to external forces such as vibration and shear, the network structure of the system is destroyed, the viscosity decreases, and the fluidity increases; once the external force decreases or stops, making the system static, the viscosity increases and the structural stability is restored. The whole process is reversible. This unique rheological property makes thixotropic resin widely used in many fields and is of great significance.

[0003] For example, in the fields of foundation engineering, shipbuilding, construction, coatings, etc. In shipbuilding, thixotropic resins are widely used in hand lay-up processes to manufacture hulls, decks and other parts. The thixotropy of thixotropic resins has anti-sagging characteristics in the hand lay-up process. It maintains good fluidity during the construction process, which is easy to apply evenly, so that the resin can well infiltrate the fiber material, ensure good bonding between the fiber and the resin, and improve the overall performance of the composite material. At the same time, it has a higher viscosity in a static state, which effectively prevents the resin from sagging on vertical or inclined surfaces, ensuring a uniform and smooth coating, and improving construction quality and efficiency. In the process of manufacturing architectural models, thixotropic resins are more conducive to evenly applying on complex shapes, making the model more precise and beautiful.

[0004] The existing thixotropic unsaturated polyester resins on the market all have the problem of poor storage stability. Especially in high temperature environments, the resins are more likely to stratify and settle, and the thixotropic effect is greatly reduced, which seriously affects the resin performance and greatly reduces the use effect, causing more losses to the factory.

[0005] There are few designs for improving the stability of thixotropic unsaturated polyester resins in the prior art. Patent 200810235455.6 discloses an unsaturated polyester resin for coating, in which ED-33 conductive additive, isopropyl alcohol additive and thixotropic agent are added to the unsaturated polyester resin, and the thixotropic agent is T40 type fumed silica, and a thixotropic resin with high gloss and anti-sagging effect is obtained by high-speed dispersion in a stirrer. However, the patent does not mention the stability of the thixotropic resin.

[0006] The thixotropic unsaturated polyester resin prepared by the prior art cannot ensure stability during long-term storage and transportation. Although the product has good performance in all aspects at the beginning, it cannot maintain thixotropic properties for a long time. After being stored for a period of time, the thixotropic effect of the resin decreases seriously, and parameters such as viscosity shift, which greatly limits its application. Therefore, it is urgent to develop a thixotropic unsaturated polyester resin with good storage stability. Summary of the invention

[0007] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a thixotropic unsaturated polyester resin with low cost, simple preparation process and good storage stability and a preparation method thereof.

[0008] The technical solution adopted by the present invention to solve the technical problem is: a thixotropic unsaturated polyester resin with good storage stability, wherein the raw materials by weight comprise: 95-99 parts of unsaturated polyester resin, 0.475-0.693 parts of fumed silica, 0.024-0.0624 parts of thixotropic additive, 0.006-0.011 parts of polymerization inhibitor, 0.029-0.0832 parts of anti-settling agent, 0.92-1.61 parts of defoaming agent and 20-35 parts of cross-linking agent.

[0009] The present invention achieves good stability of thixotropic unsaturated polyester resin in long-term storage and transportation by reasonably mixing raw materials such as unsaturated polyester resin, fumed silica, thixotropic additive, inhibitor, anti-settling agent, defoamer and cross-linking agent. As a thixotropic agent, fumed silica can effectively improve the thixotropic properties of the resin, so that the viscosity is reduced and the fluidity is enhanced when subjected to external force, while the viscosity is increased and the structural stability is restored in a static state. At the same time, the added anti-settling agent and inhibitor can effectively prevent the resin from stratifying and settling under high temperature conditions, avoiding a significant decrease in the thixotropic effect. In addition, the scheme further improves the comprehensive performance of the resin by adding a defoamer and optimizing the amount of the cross-linking agent.

[0010] Preferably, the raw material weight composition of the thixotropic unsaturated polyester resin includes: 95.8-98.1 parts of unsaturated polyester resin, 0.48-0.63 parts of fumed silica, 0.029-0.054 parts of thixotropic additive, 0.009-0.01 parts of polymerization inhibitor, 0.03-0.054 parts of anti-settling agent, 1.1-1.15 parts of defoamer, and 24-30 parts of cross-linking agent. The optimized ratio scheme not only ensures the thixotropic properties and construction convenience of the resin, but also significantly improves its storage stability and comprehensive performance after curing, making it more suitable for long-term storage and transportation.

[0011] Preferably, in the composition of the thixotropic unsaturated polyester resin, the unsaturated polyester resin is an orthophthalic unsaturated polyester resin. Orthophthalic unsaturated polyester resins are selected, such as phthalic acid-maleic anhydride-propylene glycol copolymer resins and phthalic acid-maleic anhydride-ethylene glycol copolymer resins, which have good mechanical properties and heat resistance and can remain stable under high temperature and corrosive environments. This characteristic makes it difficult for thixotropic resins to undergo stratification and sedimentation during long-term storage and use, thereby significantly improving storage stability. The molecular structure of orthophthalic resins contains benzene rings, which gives them higher strength and stability, and can further enhance thixotropic properties and anti-sagging effects. Combined with components such as fumed silica, thixotropic additives, inhibitors and anti-settling agents, orthophthalic resins can better exert their comprehensive properties, further optimize thixotropic effects and storage stability, and make them more suitable for long-term storage and widespread use.

[0012] Preferably, in the composition of the thixotropic unsaturated polyester resin, the fumed silica is hydrophilic fumed silica A200. As a thixotropic agent, hydrophilic fumed silica A200 has a high specific surface area (200±25 m² / g) and a nanometer-scale particle size (primary particle size is about 12 nm), and can form a stable three-dimensional network structure in the resin system, thereby significantly enhancing the thixotropic performance. This structure reduces the viscosity of the resin and enhances its fluidity when subjected to external force, while the viscosity is restored in a static state, effectively preventing sagging. At the same time, the hydrophilicity of A200 makes it well dispersed in the unsaturated polyester resin, and it can interact evenly with the resin matrix, further improving the stability and thixotropic effect of the system.

[0013] Preferably, in the composition of the thixotropic unsaturated polyester resin, the thixotropic additive is UP-46. UP-46 is a high molecular polymer thixotropic additive, which can be used in conjunction with hydrophilic gas silicone A200 to establish a highly efficient thixotropic effect.

[0014] Preferably, in the composition of the thixotropic unsaturated polyester resin, the polymerization inhibitor is hydroquinone, and the cross-linking agent is styrene. By combining the characteristics of hydroquinone and styrene, the thixotropic unsaturated polyester resin can improve its construction performance and the comprehensive performance after curing while ensuring the storage stability of the thixotropic unsaturated polyester resin. For the polymerization inhibitor, in addition to hydroquinone, other phenolic compounds can also be selected, such as p-hydroxyanisole, catechol or resorcinol, etc. For the cross-linking agent methyl methacrylate, dipropylene phthalate and vinyl toluene, etc., can also be used as substitutes for the cross-linking agent of the present invention, and they can form a stable cross-linked network during the curing process.

[0015] Preferably, in the composition of the thixotropic unsaturated polyester resin, the anti-settling agent is fatty alcohol polyoxyethylene ether, and the defoaming agent is HM2155. HM2155 is a modified polyether silicon compound. Its molecular structure contains many active groups, which can diffuse rapidly in the system and reduce the surface tension of the liquid, destroying the stability of the foam.

[0016] Preferably, in the composition of the thixotropic unsaturated polyester resin, the addition ratio of the thixotropic additive is 5wt%~9wt% of the fumed silica; the addition ratio of the anti-settling agent is 6wt%~12wt% of the fumed silica. Controlling the ratio of the added thixotropic additive to the fumed silica can further enhance the stability of the network structure, so that the viscosity of the resin decreases and the fluidity increases when subjected to external force, and the viscosity is restored in a static state, effectively preventing sagging. Controlling the ratio of the anti-settling agent to the fumed silica can significantly improve the anti-settling ability of the resin, ensure that no stratification or precipitation occurs during long-term storage, and further improve storage stability.

[0017] A method for preparing the above-mentioned thixotropic unsaturated polyester resin with good storage stability comprises the following steps: (1) The unsaturated polyester resin, the thixotropic agent and the anti-settling agent are mixed according to the feed ratio, and stirred evenly using a high-speed disperser.

[0018] (2) Add fumed silica and use a high-speed disperser to stir at high speed to ensure that the fumed silica is fully and evenly dispersed in the resin. Pour the mixed liquid into a grinder and grind it to a fineness of <10μm.

[0019] (3) Finally, a polymerization inhibitor, a cross-linking agent, and a defoaming agent are added to the system in sequence, and the mixture is stirred and mixed evenly to obtain the thixotropic unsaturated polyester resin with good storage stability.

[0020] This method ensures the uniform dispersion of each component in the resin system by adding and mixing each component in steps. In the first step, the unsaturated polyester resin is pre-mixed with the thixotropic agent and the anti-settling agent, and stirred evenly by a high-speed disperser, which can effectively promote the initial dispersion of the thixotropic agent and the anti-settling agent in the resin, laying the foundation for the subsequent steps. In the second step, after adding the fumed silica, high-speed stirring is performed again, and the fineness is ground by a grinder to less than 10μm. This step can further ensure the uniform distribution of the fumed silica in the resin, avoid uneven thixotropic properties or excessive local viscosity caused by agglomeration of fumed silica particles, and the fineness after grinding is less than 10μm, which can significantly improve the thixotropic properties and anti-settling properties of the resin, ensuring that it has good fluidity and anti-sagging effect during the construction process. Finally, the inhibitor, cross-linking agent and defoamer are added to the system in turn, and stirred and mixed evenly. This step-by-step addition method can effectively avoid mutual interference between the components and ensure that each additive can fully play its role. For example, inhibitors can effectively prevent the self-polymerization of the resin during storage and extend the storage period of the resin; the addition of cross-linking agents can improve the mechanical properties and chemical resistance of the resin after curing; the addition of defoaming agents can effectively reduce the bubbles generated by the resin during stirring and construction, and improve the surface quality and construction effect of the resin.

[0021] Preferably, in the preparation method of the thixotropic unsaturated polyester resin, the stirring speed in step (1) is 600 rpm / min~900 rpm / min, and the stirring time is 30 min~50 min; the stirring speed in step (2) is 500 rpm / min~2000 rpm / min, and the stirring time is 40 min~70 min; the stirring speed in step (3) is 300 rpm / min~600 rpm / min, and the stirring time is 20 min~40 min.

[0022] The set parameter range of stirring in step (1) can effectively promote the uniform mixing of unsaturated polyester resin with thixotropic additive and anti-settling agent, avoid local overheating or excessive shearing of components caused by too fast stirring speed or too long time, thereby ensuring the uniform distribution of thixotropic additive and anti-settling agent in the resin, and providing a good foundation for subsequent steps. The set parameter range of stirring in step (2) can ensure that the fumed silica is fully and evenly dispersed in the resin. Fumed silica has a high specific surface area and nanometer particle size, and is easy to agglomerate. Through high-speed stirring and appropriate time control, its agglomeration phenomenon can be effectively broken and it can be evenly distributed in the resin. At the same time, a higher stirring speed and a longer stirring time can further enhance the thixotropic properties and anti-settling ability of the resin, ensuring that it has good fluidity and anti-sagging effect during the construction process. Finally, in step (3), the stirring speed is 300rpm / min~600rpm / min, and the stirring time is 20min~40min. This relatively low stirring speed and short time can avoid excessive interference with the dispersed system, while ensuring that the inhibitor, crosslinking agent and defoamer are evenly integrated into the resin system. This mild stirring condition can effectively prevent the generation of bubbles caused by too fast stirring, while ensuring that each additive can fully exert its function, further improving the storage stability and construction performance of the resin.

[0023] The technical solution of the present invention is further described as follows: Selection of thixotropic agents. In the preparation of thixotropic fluids, thixotropic agents with better thixotropic effects include organic bentonite, fumed silica, polyurethane, polyamide, modified polyurea, etc. However, due to the different mechanisms and characteristics of thixotropy, most of them are not compatible with unsaturated polyester resin systems and cannot achieve good results. In terms of comprehensive thickening, thixotropy and anti-settling effects, organic bentonite and fumed silica are the best, but bentonite has a darker color and has a greater impact on the color of thixotropic resins, which is greatly restricted in practical applications. Fumed silica is the most widely used in the current market. Fumed silica is divided into two types: hydrophilic and hydrophobic. The hydrophobic type of fumed silica with surface hydrophobic treatment has a slightly better thixotropic effect and is relatively more stable in polar or non-polar resins, but it is difficult to fully disperse, and has higher process requirements. In addition, the price is generally several times that of the hydrophilic type. Compared with hydrophilic fumed silica, it has a higher overall cost-effectiveness and is easier to disperse, but there is a problem that it has poor stability, so an effective additive is needed to improve and solve this problem.

[0024] The surface of hydrophilic fumed silica contains a large amount of silanol (Si-OH). The hydroxyl oxygen of fatty alcohol polyoxyethylene ether can form strong hydrogen bonds with fumed silica to establish a more stable three-dimensional network structure, prevent the fumed silica from settling and precipitating, and enhance stability.

[0025] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention introduces a certain amount of anti-settling agent fatty alcohol polyoxyethylene ether into the thixotropic unsaturated polyester resin, and matches it with suitable hydrophilic fumed silica A200, so as to produce a more stable network structure between the two, thereby achieving the purpose of improving the stability of the system at high temperature and room temperature, avoiding the performance reduction of the resin during long-term storage or long-distance transportation, affecting the use effect, and increasing the loss cost.

[0026] 2. The preparation method of the present invention can control the preparation conditions of the thixotropic resin, which can not only ensure the full and uniform dispersion of the gas silicon in the system and obtain high-quality thixotropic effect, but also maximize the role of the anti-settling agent and ensure the stability of product performance. DETAILED DESCRIPTION

[0027] The present invention will be described in detail below by way of examples. It should be understood that the following examples are only used to further explain and illustrate the content of the present invention by way of example, and are not intended to limit the present invention.

[0028] The chemical additives used in the embodiments of the present invention and the comparative examples are all commercially available, and the specific information is as follows: unsaturated polyester resin: phthalic unsaturated polyester resin (phthalic acid-maleic anhydride-propylene glycol copolymer resin), purchased from Shandong Wanglin New Materials Co., Ltd.; fumed silica: A200, purchased from Qingdao Haibo Chemical Products Co., Ltd.; defoamer HM2155 and thixotropic additive UP-46, purchased from Taizhou Tianhe Chemical Co., Ltd.; hydroquinone, purchased from Guangzhou Yuansu Chemical Technology Development Co., Ltd.; fatty alcohol polyoxyethylene ether, purchased from Shanghai MacLean Biochemical Technology Co., Ltd.; styrene, purchased from Beijing Huihai Petrochemical Co., Ltd.

[0029] Example 1 A thixotropic unsaturated polyester resin with good storage stability comprises the following raw materials in parts by weight: 97 parts of orthophthalic unsaturated polyester resin, 0.59 parts of A200, 0.036 parts of UP-46, 0.009 parts of hydroquinone, 0.054 parts of fatty alcohol polyoxyethylene ether, 26 parts of styrene and 1.11 parts of HM2155.

[0030] The method for preparing the thixotropic unsaturated polyester resin with good storage stability comprises the following steps: The o-phthalate unsaturated polyester resin is mixed with UP-46 and fatty alcohol polyoxyethylene ether according to the feed ratio, and stirred evenly at a speed of 600rpm / min using a high-speed disperser for 45min. A200 is then added in batches, and stirred evenly at a high speed of 1200rpm / min using a high-speed disperser for 65min, and then the mixed solution is poured into a grinder and ground to a fineness of <10μm. Finally, hydroquinone, styrene, and HM2155 are added to the system in turn, and stirred evenly at 400rpm / min for 40min to obtain the thixotropic unsaturated polyester resin with good storage stability.

[0031] Example 2 A thixotropic unsaturated polyester resin with good storage stability comprises the following components in parts by weight: 96.2 parts of orthophthalic unsaturated polyester resin, 0.54 parts of A200, 0.044 parts of UP-46, 0.009 parts of hydroquinone, 0.044 parts of fatty alcohol polyoxyethylene ether, 25 parts of styrene and 1.11 parts of HM2155.

[0032] The method for preparing the thixotropic unsaturated polyester resin with good storage stability comprises the following steps: The o-phthalate unsaturated polyester resin is mixed with UP-46 and fatty alcohol polyoxyethylene ether according to the feed ratio, and stirred evenly at a speed of 900rpm / min using a high-speed disperser for 45min. A200 is then added in batches, and stirred evenly at a high speed of 600rpm / min using a high-speed disperser for 42min, and then the mixed solution is poured into a grinder and ground to a fineness of <10μm. Finally, hydroquinone, styrene, and HM2155 are added to the system in turn, and stirred at 500rpm / min for 25min to mix evenly, thereby obtaining the thixotropic unsaturated polyester resin with good storage stability.

[0033] Example 3 A thixotropic unsaturated polyester resin with good storage stability comprises the following components in parts by weight: 98.1 parts of orthophthalic unsaturated polyester resin, 0.56 parts of A200, 0.029 parts of UP-46, 0.009 parts of hydroquinone, 0.035 parts of fatty alcohol polyoxyethylene ether, 27 parts of styrene and 1.11 parts of HM2155.

[0034] The method for preparing the thixotropic unsaturated polyester resin with good storage stability comprises the following steps: The o-phthalate unsaturated polyester resin is mixed with UP-46 and fatty alcohol polyoxyethylene ether according to the feed ratio, and stirred evenly at a speed of 700rpm / min using a high-speed disperser for 30min. A200 is then added in batches, and stirred evenly at a high speed of 700rpm / min using a high-speed disperser for 42min, and then the mixed solution is poured into a grinder and ground to a fineness of <10μm. Finally, hydroquinone, styrene, and HM2155 are added to the system in turn, and stirred at 450rpm / min for 33min to mix evenly, to obtain the thixotropic unsaturated polyester resin with good storage stability.

[0035] Example 4 A thixotropic unsaturated polyester resin with good storage stability comprises the following components in parts by weight: 95.8 parts of orthophthalic unsaturated polyester resin, 0.48 parts of A200, 0.034 parts of UP-46, 0.009 parts of hydroquinone, 0.030 parts of fatty alcohol polyoxyethylene ether, 24 parts of styrene and 1.11 parts of HM2155.

[0036] The method for preparing the thixotropic unsaturated polyester resin with good storage stability comprises the following steps: The o-phthalate unsaturated polyester resin is mixed with UP-46 and fatty alcohol polyoxyethylene ether according to the feed ratio, and stirred evenly at a speed of 800rpm / min using a high-speed disperser for 38min. A200 is then added in batches, and stirred evenly at a high speed of 1000rpm / min using a high-speed disperser for 60min, and then the mixed solution is poured into a grinder and ground to a fineness of <10μm. Finally, hydroquinone, styrene, and HM2155 are added to the system in turn, and stirred at 550rpm / min for 40min to mix evenly, thereby obtaining the thixotropic unsaturated polyester resin with good storage stability.

[0037] Example 5 A thixotropic unsaturated polyester resin with good storage stability comprises the following components in parts by weight: 97.5 parts of orthophthalic unsaturated polyester resin, 0.63 parts of A200, 0.054 parts of UP-46, 0.009 parts of hydroquinone, 0.046 parts of fatty alcohol polyoxyethylene ether, 30 parts of styrene and 1.11 parts of HM2155.

[0038] The method for preparing the thixotropic unsaturated polyester resin with good storage stability comprises the following steps: The o-phthalate unsaturated polyester resin is mixed with UP-46 and fatty alcohol polyoxyethylene ether according to the feed ratio, and stirred evenly at a speed of 600rpm / min using a high-speed disperser for 38min. A200 is then added in batches, and stirred evenly at a high speed of 1500rpm / min using a high-speed disperser for 50min, and then the mixed solution is poured into a grinder and ground to a fineness of <10μm. Finally, hydroquinone, styrene, and HM2155 are added to the system in turn, and stirred at 480rpm / min for 33min to mix evenly, thereby obtaining the thixotropic unsaturated polyester resin with good storage stability.

[0039] Comparative Example 1 This comparative example is the same as Example 1, except that the stirring speed and time of the preparation method are different; The method for preparing the thixotropic unsaturated polyester resin with good storage stability comprises the following steps: The o-phthalate unsaturated polyester resin is mixed with UP-46 and fatty alcohol polyoxyethylene ether according to the feed ratio, and stirred evenly at a speed of 200rpm / min using a high-speed disperser for 30min. A200 is then added in batches, and stirred evenly at a high speed of 400rpm / min using a high-speed disperser for 40min, and then the mixed solution is poured into a grinder and ground to a fineness of <10μm. Finally, hydroquinone, styrene, and HM2155 are added to the system in turn, and stirred at 1000rpm / min for 30min to obtain the thixotropic unsaturated polyester resin with good storage stability.

[0040] Comparative Example 2 This comparative example is the same as Example 1, except that no fatty alcohol polyoxyethylene ether is added.

[0041] Comparative Example 3 This comparative example is the same as Example 1, except that: the order of adding the raw materials in the preparation method is different; The method for preparing the thixotropic unsaturated polyester resin with good storage stability comprises the following steps: The A200 is added to the orthophthalic unsaturated polyester resin in batches according to the feed ratio, and a high-speed disperser is used to stir evenly at a high speed of 1200 rpm / min for 65 minutes, and then the mixed solution is poured into a grinder and ground to a fineness of <10 μm. Finally, UP-46, fatty alcohol polyoxyethylene ether, hydroquinone, styrene, and HM2155 are added to the system in sequence, and stirred at 400 rpm / min for 33 minutes to mix evenly, thereby obtaining the thixotropic unsaturated polyester resin with good storage stability.

[0042] Performance Testing 1. Stability test The stability test of the thixotropic unsaturated polyester resin obtained in the embodiment and the comparative example was carried out. The samples were divided into transparent sample bottles and sealed, and stored in a constant temperature oven at room temperature of 25°C and 60°C for 60 days and 15 days respectively. The changes in the appearance of the samples were observed and recorded. The thixotropic value of the samples before and after storage was tested using an NDJ viscometer, and the thixotropic value test temperature was 25°C. The test results are shown in Table 1 below.

[0043] Table 1 Room temperature and high temperature stability results of examples and comparative examples .

[0044] The performance test results of the embodiments and comparative examples in Table 1 can verify that the present invention can greatly improve the storage stability of the thixotropic resin by adding fatty alcohol polyoxyethylene ether, and the addition of fatty alcohol polyoxyethylene ether does not affect the initial thixotropic value of the resin, and long-term storage will not cause obvious thixotropic value reduction, stratification and gas silicon precipitation. The thixotropic effect is relatively stable, which can extend the sample storage period, reduce the loss cost, and ensure the stability of product performance. Example 1 is the best formula ratio and preparation process. On this basis, reducing the addition of anti-settling agent, changing the order of adding anti-settling agent, and reducing the dispersion speed and time of gas silicon will affect the stability and thixotropic effect of the obtained thixotropic resin to a certain extent.

[0045] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A thixotropic unsaturated polyester resin with good storage stability, characterized in that: The raw materials include, by weight, 95 to 99 parts of unsaturated polyester resin, 0.475 to 0.693 parts of fumed silica, 0.024 to 0.0624 parts of thixotropic additive, 0.006 to 0.011 parts of polymerization inhibitor, 0.029 to 0.0832 parts of anti-settling agent, 0.92 to 1.61 parts of defoaming agent, and 20 to 35 parts of cross-linking agent.

2. The thixotropic unsaturated polyester resin with good storage stability according to claim 1, characterized in that: The unsaturated polyester resin is an orthophthalic unsaturated polyester resin.

3. The thixotropic unsaturated polyester resin with good storage stability according to claim 1, characterized in that: The polymerization inhibitor is hydroquinone.

4. The thixotropic unsaturated polyester resin with good storage stability according to claim 1, characterized in that: The cross-linking agent is styrene.

5. The thixotropic unsaturated polyester resin with good storage stability according to claim 1, characterized in that: The anti-settling agent is fatty alcohol polyoxyethylene ether.

6. The thixotropic unsaturated polyester resin with good storage stability according to claim 1, characterized in that: The addition ratio of the thixotropic agent is 5wt% to 9wt% of the fumed silica.

7. The thixotropic unsaturated polyester resin with good storage stability according to claim 1, characterized in that: The anti-settling agent is added in an amount of 6wt% to 12wt% of the fumed silica.

8. A method for preparing a thixotropic unsaturated polyester resin having good storage stability according to any one of claims 1 to 7, characterized in that: The steps include: (1) mixing the unsaturated polyester resin, the thixotropic agent and the anti-settling agent according to the feed ratio, and stirring them evenly using a high-speed disperser; (2) Add fumed silica and use a high-speed disperser to stir at high speed to ensure that the fumed silica is fully and evenly dispersed in the resin. Pour the mixed liquid into a grinder and grind it to a fineness of <10μm; (3) Finally, a polymerization inhibitor, a cross-linking agent, and a defoaming agent are added to the system in sequence and stirred to mix evenly, thereby obtaining the thixotropic unsaturated polyester resin with good storage stability.

9. The method for preparing a thixotropic unsaturated polyester resin having good storage stability according to claim 8, characterized in that: The stirring speed of step (1) is 600 rpm / min~900 rpm / min, and the stirring time is 30 min~50 min; the stirring speed of step (2) is 500 rpm / min~2000 rpm / min, and the stirring time is 40 min~70 min; the stirring speed of step (3) is 300 rpm / min~600 rpm / min, and the stirring time is 20 min~40 min.