A crystalline organic thixotropic agent, its synthesis method and application

Abstract

The application relates to the technical field of thixotropic agents, in particular to a crystalline organic thixotropic agent and a synthesis method and application thereof. The synthesis method of the crystalline organic thixotropic agent comprises the following steps: mixing isocyanate and monohydric alcohol according to a molar ratio of isocyanate and hydroxyl of 1:1, and reacting at 80 DEG C-145 DEG C to obtain the crystalline organic thixotropic agent. The isocyanate is reacted with the monohydric alcohol to prepare the high-crystallinity organic thixotropic agent. The crystalline organic thixotropic agent is added into resin, is dissolved after heating, and is cooled to separate out crystals. The limited phase solubility and adsorption of the crystals make the resin have thixotropy, and the white paste-like resin with strong thixotropy is obtained. The gelation phenomenon is not prone to occurring in the production and preparation process or the storage process of the polyurethane resin, and the thixotropy effect is good.

Description

Technical Field

[0001] This invention relates to the field of thixotropic agents, and in particular to a crystalline organic thixotropic agent, its synthesis method, and its application. Background Technology

[0002] During facade construction and crack repair, paints and adhesives can flow due to gravity, resulting in uneven film application and inability to fill cracks. Adding thixotropic agents to paints and adhesives can effectively solve these problems. This is because thixotropic agents form weak interactions within the continuous resin phase, producing thixotropy. Under external force, they thin out under shear, and thicken again after the force is removed. The addition of thixotropic agents ensures that the application of paints and adhesives is not affected, while also preventing them from flowing due to gravity.

[0003] Thixotropic agents commonly used in coatings and adhesives include fumed silica, organobentonite, polyamide wax, polyurea, ethylene wax, hydrogenated castor oil, metal soaps, and hydroxyethyl cellulose. The main principle behind these thixotropic agents is that they generate thixotropic properties by creating weak interactions within the continuous resin phase through adsorption, hydrogen bonding, ionic bonding, and thermodynamic limited solubility. However, when used in polyurethane systems, the high reactivity of isocyanates can easily lead to gelation during production or storage. For example, fumed silica, due to its high specific surface area and strong interfacial tension, readily adsorbs moisture. If the silica powder is not dehydrated at high temperatures, the moisture will cross-link with the isocyanate components during storage, resulting in gelation. As for polyamide wax, since polyamide wax itself is a highly polar material, it usually needs to be activated by adding a certain amount of small molecule alcohol solvent. However, the active hydrogen of alcohol can easily react with isocyanate ions. Furthermore, due to the similarity between amide bonds and urethane bonds, most polyamide waxes are easily soluble in polyurethane, resulting in poor thixotropic effects or even no thixotropic effects.

[0004] During the research process, the applicant discovered that there are currently no literature reports on crystalline organic thixotropic agents. Summary of the Invention

[0005] To address the gelation phenomenon of existing thixotropic agents and improve their thixotropic effects, this application provides a crystalline organic thixotropic agent, its synthesis method, and its application.

[0006] In a first aspect, this application provides a method for synthesizing a crystalline organic thixotropic agent, which is achieved by the following technical solution: A method for synthesizing a crystalline organic thixotropic agent includes the following steps: mixing isocyanate and monohydric alcohol at a molar ratio of isocyanate to hydroxyl group of 1:1, and reacting at 80℃-145℃ to obtain a crystalline organic thixotropic agent.

[0007] By employing the above technical solution, a highly crystalline organic thixotropic agent is prepared by reacting isocyanate with a monohydric alcohol. The crystalline organic thixotropic agent is added to the resin, heated to melt, and then cooled to precipitate crystals. Through the limited miscibility and adsorption of the crystals, the resin exhibits thixotropy, resulting in a white paste-like resin with strong thixotropic properties and excellent thixotropic effect. The crystalline organic thixotropic agent synthesized in this application, when used in polyurethane resins, is less prone to gelation during the production or storage of polyurethane resins and exhibits excellent thixotropic effects.

[0008] Preferably, the synthesis method includes the following steps: mixing isocyanate and monohydric alcohol at a molar ratio of isocyanate to hydroxyl of 1:1, adding a catalyst of 0.01wt%-0.1wt%, and reacting at 80℃-145℃ to obtain a crystalline organic thixotropic agent.

[0009] In this application, the catalytic amount refers to the percentage of the mass of the catalyst to the total mass of the isocyanate and monohydric alcohol.

[0010] In this application, the catalyst is bismuth neodecanoate and / or dibutyltin dilaurate; preferably, the catalyst is dibutyltin dilaurate.

[0011] By adopting the above technical solution, the addition of catalyst increases the reaction rate and improves the thixotropic effect of crystalline organic thixotropic agents.

[0012] Preferably, the monohydric alcohol is selected from one or more of the following: straight-chain alkanols with no more than twelve carbon atoms, straight-chain alkanols with more than twelve carbon atoms, branched alkanols, straight-chain monohydric alcohols modified with ethylene oxide, and straight-chain monohydric alcohols modified with polycaprolactone.

[0013] Preferably, the straight-chain alkanol with no more than twelve carbon atoms is a straight-chain alkanol with 1-12 carbon atoms.

[0014] Preferably, the straight-chain alkanol with 1-12 carbon atoms is selected from one or more of methanol, ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol, n-decanol, n-undecanol, and n-dodecanol.

[0015] Preferably, the straight-chain alkanol with more than twelve carbon atoms is a straight-chain alkanol with 13-30 carbon atoms.

[0016] Preferably, the straight-chain alkanol with 13-30 carbon atoms is selected from one or more of n-tetrazol, n-tetradecanool, n-pentadecanol, n-hexadecanool, n-heptadecanool, n-octadecanool, n-nonadecanol, n-eicosyl alcohol, n-timodecanool, n-timodecanool, n-timodecanool, n-timodecanool, n-timodecanool, n-timodecanool, n-timodecanool, and n-triadecanol.

[0017] During the research process, the applicant discovered that the melting point of thixotropic agents corresponding to straight-chain alkanols with 1-12 carbon atoms is lower than that of thixotropic agents corresponding to straight-chain alkanols with 13-30 carbon atoms, and the amount of thixotropic agents corresponding to straight-chain alkanols with 1-12 carbon atoms used in the resin is higher than that of thixotropic agents corresponding to straight-chain alkanols with 13-30 carbon atoms used in the resin.

[0018] Preferably, the branched alkanol is a branched alkanol with 3-30 carbon atoms.

[0019] Preferably, the branched alkanol with 3-30 carbon atoms is selected from isopropanol, the hydroxyl-containing isomers corresponding to n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol, n-decanol, n-undecanol, n-dodecanol, n-tetanecanol, n-tridecanol, n-tetradecanol, n-pentadecanol, n-hexadecanol, n-pentadecanol, n-hexadecanol, and n-heptadecanol. The hydroxyl-containing isomers of n-octadecyl alcohol, n-nonadecanol, n-eicosyl alcohol, n-timosanol, n-timosanol, n-timosanol, n-timosanol, n-timosanol, n-timosanol, n-timosanol, n-timosanol, n-timosanol, n-timosanol, n-timosanol, n-timosanol, n-timosanol, n-timosanol, n-timosanol, n-timosanol, and n-timosanol are one or more of the following:

[0020] In this application, the hydroxyl-containing isomer of n-butanol refers to any one of isobutanol, sec-butanol, and tert-butanol; that is, the hydroxyl-containing isomer of n-butanol refers to an alcohol with 4 carbon atoms other than n-butanol. Similarly, the hydroxyl-containing isomer of n-pentanol refers to an alcohol with 5 carbon atoms other than n-pentanol, and the hydroxyl-containing isomer of n-trianetrahydrol refers to an alcohol with 30 carbon atoms other than n-trianetrahydrol.

[0021] During the research process, the applicant discovered that, when the number of carbon atoms in a monohydric alcohol is the same, the melting point of the thixotropic agent corresponding to a branched alkanol is lower than that of the thixotropic agent corresponding to a straight-chain alkanol, and a larger amount of branched alkanol is used in the preparation of thixotropic resins; moreover, the longer the branch of the branched alkanol, the lower the melting point of the corresponding thixotropic agent, and the larger the amount used in the preparation of thixotropic resins.

[0022] In this application, the ethylene oxide-modified linear monohydric alcohol is obtained by ring-opening polymerization of a monohydric alcohol and ethylene oxide.

[0023] In this application, the ethylene oxide-modified linear monohydric alcohols include, but are not limited to: polyoxyethylene monooctyl ether, polyoxyethylene monododecyl ether, polyoxyethylene monotetradecyl ether, polyoxyethylene monohexadecyl ether, and polyoxyethylene monooctadecyl ether.

[0024] In this application, the linear monohydric alcohol modified with polycaprolactone is obtained by ring-opening polymerization of a monohydric alcohol and caprolactone.

[0025] In this application, the polycaprolactone-modified linear monohydric alcohols include, but are not limited to: polycaprolactone monohydric alcohols initiated by n-octanol, polycaprolactone monohydric alcohols initiated by n-dodecanol, polycaprolactone monohydric alcohols initiated by n-tetradecanol, polycaprolactone monohydric alcohols initiated by n-hexadecanol, and polycaprolactone monohydric alcohols initiated by n-octadecanol.

[0026] During the research process, the applicant discovered that crystalline organic thixotropic agents can also be obtained by reacting ethylene oxide-modified linear monohydric alcohols and polycaprolactone-modified linear monohydric alcohols with isocyanates. However, compared with the linear monohydric alcohols before modification, the melting points of the thixotropic agents corresponding to the ethylene oxide-modified linear monohydric alcohols and polycaprolactone-modified linear monohydric alcohols are significantly lower.

[0027] In this application, the molecular weight of the ethylene oxide-modified linear monohydric alcohol and the polycaprolactone-modified linear monohydric alcohol does not exceed 1600.

[0028] In this application, the molecular weight is the index-average molecular weight.

[0029] In this application, the molecular weight of the straight-chain monohydric alcohol modified with ethylene oxide is 174-1590.

[0030] In this application, the molecular weights of the ethylene oxide-modified straight-chain monohydric alcohols can be listed as: 174, 318, 434, 682, and 1590.

[0031] Preferably, the ethylene oxide content in the ethylene oxide-modified straight-chain monohydric alcohol is 25.3 wt% to 83 wt%.

[0032] In this application, the ethylene oxide content in the ethylene oxide-modified linear monohydric alcohol can be listed as follows: 25.3 wt%, 42.3 wt%, 50.7 wt%, 64.5 wt%, and 83 wt%.

[0033] In this application, the molecular weight of the polycaprolactone-modified linear monohydric alcohol is 244-1410.

[0034] In this application, the molecular weights of the linear monohydric alcohol modified with polycaprolactone can be listed as: 244, 528, 784, 1040, and 1410.

[0035] Preferably, the caprolactone content in the polycaprolactone-modified linear monohydric alcohol is 46.7 wt% to 80.8 wt%.

[0036] In this application, the caprolactone content in the polycaprolactone-modified linear monohydric alcohol can be listed as 46.7 wt%, 64.8 wt%, 72.7 wt%, 76.7 wt%, and 80.8 wt%.

[0037] During the research process, the applicant discovered that, for both ethylene oxide-modified and polycaprolactone-modified linear monohydric alcohols, the melting point of the thixotropic agent decreased with increasing ethylene oxide content, and the amount of thixotropic agent added increased with increasing polycaprolactone content. This is mainly because, during the modification process of ethylene oxide-modified and polycaprolactone-modified linear monohydric alcohols, the molecular weight of the monohydric alcohol is no longer a small molecule with a fixed molecular weight, but rather a mixture of small molecule monohydric alcohols with a certain molecular weight distribution. The thixotropic agent obtained after reacting with isocyanate also has a certain molecular weight distribution. The crystals obtained by crystallizing the thixotropic agent disrupt the regularity of the crystal lattice, thereby lowering the melting point of the crystal.

[0038] In one specific embodiment, the monohydric alcohol is any one of methanol, n-butanol, n-octanol, n-dodecanol, n-hexadecanol, n-octadecanol, n-eicosanool, n-hexadecanol, n-triacontanol, isobutanol, 2-ethylhexanol, 2-octyldodecanol, polyoxyethylene monooctyl ether, polyoxyethylene monododecyl ether, polyoxyethylene monohexadecyl ether, polyoxyethylene monooctadecyl ether, polycaprolactone monohydric alcohol initiated by n-octanol, polycaprolactone monohydric alcohol initiated by n-dodecanol, polycaprolactone monohydric alcohol initiated by n-tetradecanol, polycaprolactone monohydric alcohol initiated by n-hexadecanol, and polycaprolactone monohydric alcohol initiated by n-octadecanol.

[0039] In one specific embodiment, the monohydric alcohol is a mixture of n-octanol and n-dodecanol, wherein the molar ratio of n-octanol to n-dodecanol is 0.7:1.3.

[0040] In one specific embodiment, the monohydric alcohol is a mixture of 2-ethylhexanol and n-dodecyl alcohol, wherein the molar ratio of 2-ethylhexanol to n-dodecyl alcohol is 1:1.

[0041] In one specific embodiment, the monohydric alcohol is a mixture of polycaprolactone monohydric alcohol initiated by n-dodecanool, n-dodecanool, and n-octadecanool, wherein the molar ratio of the polycaprolactone monohydric alcohol initiated by n-dodecanool, n-dodecanool, and n-octadecanool is 0.7:0.7:0.6.

[0042] During the research process, the applicant discovered that monohydric alcohols can be a mixture of two or more monohydric alcohols. Thixotropic agents prepared by reacting monohydric alcohols with isocyanates also have crystallinity, but have a wider melting point range.

[0043] Preferably, the isocyanate is selected from one or more derivatives of isocyanate HDI, isocyanate IPDI, isocyanate HMDI, isocyanate MDI, isocyanate TDI, and isocyanate HDI.

[0044] Preferably, the derivative of isocyanate HDI is selected from one or more of isocyanate HDI trimer, isocyanate HDI dimer, isocyanate HDI biuret, and isocyanate HDI urethane.

[0045] In one specific embodiment, the isocyanate is any one of isocyanate monomer HDI, isocyanate monomer IPDI, isocyanate monomer HMDI, isocyanate monomer MDI, isocyanate monomer TDI, isocyanate HDI dimer N3400, isocyanate HDI trimer HT-100, isocyanate HDI biuret 24A-100, and isocyanate HDI urethane FL100.

[0046] Preferably, the reaction temperature of the isocyanate with the monohydric alcohol is 105°C-145°C.

[0047] Secondly, this application provides a crystalline organic thixotropic agent, which is achieved using the following technical solution: A crystalline organic thixotropic agent was prepared by the above-described synthesis method.

[0048] The crystalline organic thixotropic agent provided in this application has the following main principle: the thixotropic agent is heated and melted in the resin and then cooled to precipitate crystals. The limited miscibility and adsorption of the crystals cause the resin to produce thixotropy, resulting in a white paste-like resin with strong thixotropic properties and good thixotropic effect.

[0049] Thirdly, this application provides an application of a crystalline organic thixotropic agent, achieved through the following technical solution: An application of a crystalline organic thixotropic agent, wherein the crystalline organic thixotropic agent is used as a thixotropic agent for polyurethane resin, acrylic resin, epoxy resin, and polyaspartic acid ester, and the amount of the crystalline organic thixotropic agent is 1.7wt%-22wt%.

[0050] The crystalline organic thixotropic agent synthesized in this application is used in polyurethane resins. It is less prone to gelation during the production or storage of polyurethane resins and exhibits good thixotropic effects.

[0051] In summary, this application has the following beneficial effects: 1. This application prepares a highly crystalline organic thixotropic agent by reacting isocyanate with a monohydric alcohol. The crystalline organic thixotropic agent is added to the resin, heated to melt, and then cooled to precipitate crystals. The resin exhibits thixotropy through the limited miscibility and adsorption of the crystals, resulting in a white paste-like resin with strong thixotropic properties. It has a good thixotropic effect and is used in polyurethane resins. It is not prone to gelation during the production or storage of polyurethane resins.

[0052] 2. The thixotropic agents of straight-chain alkanols with 1-12 carbon atoms used in this application have melting points lower than those of straight-chain alkanols with 13-30 carbon atoms.

[0053] 3. When monohydric alcohols have the same number of carbon atoms, the melting point of the thixotropic agent corresponding to branched alkanols is lower than that of the thixotropic agent corresponding to straight-chain alkanols. Branched alkanols are used in greater quantities when preparing thixotropic resins. Moreover, the longer the branch of the branched alkanol, the lower the melting point of the corresponding thixotropic agent.

[0054] 4. Compared with the unmodified linear monohydric alcohols, the melting points of the corresponding thixotropic agents of linear monohydric alcohols modified with ethylene oxide and linear monohydric alcohols modified with polycaprolactone are significantly lower.

[0055] 5. For linear monohydric alcohols modified with ethylene oxide, the melting point of the thixotropic agent decreases with increasing ethylene oxide content. For linear monohydric alcohols modified with polycaprolactone, the melting point of the thixotropic agent decreases with increasing polycaprolactone content, and the amount of thixotropic agent added increases. Detailed Implementation

[0056] The present application will be further described in detail below with reference to the embodiments. Example

[0057] Examples 1-33 provide a crystalline organic thixotropic agent, and the following description uses Example 1 as an example.

[0058] The crystalline organic thixotropic agent provided in Example 1 is synthesized as follows: 168g of isocyanate monomer HDI (2mol of NCO group) and 64g of methanol (2mol of hydroxyl group) were added to a four-necked flask, heated to dissolve, and reacted completely at 105℃. After cooling to 25℃, a crystalline organic thixotropic agent was obtained.

[0059] Examples 2-33 differ from Example 1 in the following ways: Table 1.

[0060] Table 1 Experimental conditions for Examples 1-33 Performance testing The following performance tests were conducted on the crystalline organic thixotropic agents prepared in Examples 1-33 of this application.

[0061] 1. Physical appearance: Observe the physical appearance of the crystalline organic thixotropic agents in Examples 1-33. The test results are shown in Table 2.

[0062] 2. Melting point: The melting point of the crystalline organic thixotropic agents in Examples 1-33 was tested, and the test results are shown in Table 2.

[0063] Table 2 Test results of physical appearance and melting point Application examples The crystalline organic thixotropic agents prepared in Examples 1-33 of this application were added to polyurethane resin HT100, acrylic resin setalux 1753, epoxy resin E51, and polyaspartic acid ester resin F420 respectively (the specific amount of thixotropic agent is shown in Table 3). After heating and melting, the mixture was cooled to 25°C, and the thixotropic properties of the resins after adding the crystalline organic thixotropic agents from Examples 1-33 were tested. The test results are shown in Table 3.

[0064] Table 3. Thixotropic agent dosage and thixotropic effect The amount of thixotropic agent used refers to the mass percentage of the thixotropic agent to the resin.

[0065] The following details this application based on the test data in Tables 2 and 3.

[0066] The test data from Examples 1-30 show that Examples 1-30 involve a single monohydric alcohol. The reaction of isocyanate and monohydric alcohol at a molar ratio of isocyanate to hydroxyl groups of 1:1 yields a white crystalline substance, i.e., a crystalline organic thixotropic agent. The melting point of the crystalline organic thixotropic agent is related to the molecular structure of the monohydric alcohol. The melting point of the crystalline organic thixotropic agent affects the amount of thixotropic agent used in the resin. In the same resin, a higher melting point of the crystalline organic thixotropic agent requires a smaller amount to form a white paste, resulting in a better thixotropic effect. While the amount of thixotropic agent varies slightly between different resins when the thixotropic agent is the same, the effect is not significant.

[0067] The test data from Examples 1-4 and Examples 5-9 show that Examples 1-4 are straight-chain alkanols with no more than twelve carbon atoms, while Examples 5-9 are straight-chain alkanols with more than twelve carbon atoms. The melting point of the thixotropic agents corresponding to Examples 1-4 is lower than that of the thixotropic agents corresponding to Examples 5-9. The amount of thixotropic agents corresponding to straight-chain alkanols with more than twelve carbon atoms used in the resin is relatively low, and the performance of thixotropic agents corresponding to straight-chain alkanols with more than twelve carbon atoms has little effect on the number of carbon atoms in the monohydric alcohol.

[0068] Example 2 uses n-butanol, Example 18 uses isobutanol; Example 3 uses n-octanol, Example 19 uses 2-ethylhexanol; Example 7 uses n-eicosanol, Example 20 uses 2-octyldodecylol. From the test data of Examples 2 and 18, or Examples 3 and 19, or Examples 3 and 19, it can be seen that when the number of carbon atoms of the monohydric alcohol is the same, the melting point of the thixotropic agent corresponding to the branched monohydric alcohol is lower than that of the straight monohydric alcohol corresponding to the thixotropic agent, and the amount of the thixotropic agent corresponding to the branched monohydric alcohol is higher.

[0069] The test data from Examples 18-20 show that the longer the branched chain of the branched monohydric alcohol, the lower the melting point of the corresponding thixotropic agent, and the greater the amount of thixotropic agent used in the resin.

[0070] The test data from Examples 21-25 show that the crystalline organic thixotropic agents prepared by reacting ethylene oxide-modified straight-chain monohydric alcohols with isocyanates exhibit a significant decrease in melting point, requiring a larger addition amount. Furthermore, the melting point of the thixotropic agent decreases with increasing ethylene oxide content. This is mainly because the monohydric alcohols during the modification process are no longer small molecules with a fixed molecular weight, but rather a mixture of small-molecule monohydric alcohols with a certain molecular weight distribution. The thixotropic agents obtained after reacting ethylene oxide-modified straight-chain monohydric alcohols with isocyanates also have a certain molecular weight distribution, disrupting the regularity of the crystalline organic thixotropic agent crystal lattice and thus lowering the melting point of the crystalline organic thixotropic agent crystals.

[0071] The test data from Examples 26-30 show that the crystalline organic thixotropic agents prepared by reacting polycaprolactone-modified linear monohydric alcohols with isocyanates exhibit a significant decrease in melting point, requiring a larger addition amount. Furthermore, the melting point of the thixotropic agent decreases with increasing polycaprolactone content. This is mainly because the monohydric alcohols during the modification process are no longer small molecules with a fixed molecular weight, but rather a mixture of small molecule monohydric alcohols with a certain molecular weight distribution. The thixotropic agents obtained after reacting polycaprolactone-modified linear monohydric alcohols with isocyanates also have a certain molecular weight distribution, disrupting the regularity of the crystalline organic thixotropic agent crystal lattice and thus lowering the melting point of the crystalline organic thixotropic agent crystals.

[0072] The test data from Examples 31-33 show that when the monohydric alcohol is a mixture of two or more monohydric alcohols, it can also react with isocyanate to obtain crystalline organic thixotropic agents. The thixotropic agents prepared by mixing monohydric alcohols have a wider melting point range.

[0073] Example 6 uses the isocyanate monomer HDI, which has a symmetrical structure; Example 11 uses the isocyanate monomer HMDI, which has a symmetrical structure; Example 12 uses the isocyanate monomer MDI, which has a symmetrical structure; while Example 10 uses the isocyanate monomer IPDI, which has an asymmetrical structure; and Example 13 uses the isocyanate monomer TDI, which has an asymmetrical structure. From the test data of Examples 6, 11, 12 and Examples 10, 13, it can be seen that when the monohydric alcohol is the same, the thixotropic agents corresponding to the symmetrical isocyanate monomers HDI, HMDI, and MDI have higher melting points and stronger crystallinity, and are added in less amount in the resin. The thixotropic agents corresponding to the poorly structured isocyanate monomers TDI and IPDI have lower melting points and weaker crystallinity, and are added in more amount in the resin.

[0074] Example 14 is an HDI isocyanate trimer, and Example 16 is an HDI isocyanate dimer, both with good structural symmetry; while Example 15 is an HDI isocyanate biuret and Example 17 is an HDI isocyanate urea carbamate, both with poor structural symmetry. The HDI trimer and HDI dimer, with better structural symmetry, have higher melting points than the thixotropic agents corresponding to HDI isocyanate biuret and HDI isocyanate urea carbamate, respectively. The HDI trimer and HDI dimer require less thixotropic agent addition, while the HDI isocyanate urea carbamate contains branched chains, and the HDI isocyanate urea carbamate requires the largest amount of thixotropic agent.

[0075] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. The application of a crystalline organic thixotropic agent, characterized in that, The crystalline organic thixotropic agent is used as a thixotropic agent for polyurethane resin, acrylic resin, epoxy resin or polyaspartic acid ester, and the amount of the crystalline organic thixotropic agent is 1.7wt%-22wt%; and the synthesis method of the crystalline organic thixotropic agent includes the following steps: mixing isocyanate and monohydric alcohol at a molar ratio of isocyanate to hydroxyl groups of 1:1, adding a catalyst with a catalytic amount of 0.009wt%-0.1wt%, and reacting at 80℃-145℃ to obtain the crystalline organic thixotropic agent; The isocyanate is selected from one or more of isocyanate HDI, isocyanate IPDI, isocyanate HMDI, isocyanate MDI, isocyanate TDI, and derivatives of isocyanate HDI; the derivative of isocyanate HDI is selected from one or more of isocyanate HDI trimer, isocyanate HDI dimer, isocyanate HDI biuret, and isocyanate HDI urethane. The monohydric alcohol is any one of methanol, n-butanol, n-octanol, n-dodecanol, n-hexadecanol, n-octadecanol, n-eicosanool, n-hexadecanol, n-triacontanol, isobutanol, 2-ethylhexanol, 2-octyldodecanol, polyoxyethylene monooctyl ether, polyoxyethylene monododecyl ether, polyoxyethylene monohexadecyl ether, polyoxyethylene monooctadecyl ether, polycaprolactone monohydric alcohol initiated by n-octanol, polycaprolactone monohydric alcohol initiated by n-dodecanol, polycaprolactone monohydric alcohol initiated by n-tetradecanol, polycaprolactone monohydric alcohol initiated by n-hexadecanol, and polycaprolactone monohydric alcohol initiated by n-octadecanol.

2. The application of the crystalline organic thixotropic agent according to claim 1, characterized in that, The reaction temperature of the isocyanate with the monohydric alcohol is 105℃-145℃.

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