NANO calcium carbonate microcrystal dispersion system, and preparation method therefor and use thereof

Abstract

The present application relates to the technical field of calcium carbonate preparation, and provides a nano calcium carbonate microcrystal dispersion system, and a preparation method therefor and a use thereof. In the present application, no volatile organic solvent is used, and the prepared nano calcium carbonate microcrystal dispersion system exhibits colloidal stability. First, a mixed reaction solution is provided, wherein the mixed reaction solution comprises the following components in parts by mass: 50-80 parts of an oily dispersion medium, 5-30 parts of a primary organic acid, 0.1-10 parts of a secondary organic acid, 0-10 parts of an inorganic acid, and 0-10 parts of an accelerant; the mixed reaction solution is mixed with a calcium-containing inorganic substance for a neutralization reaction to obtain a neutralization product feed liquid; carbon dioxide is introduced into the neutralization product feed liquid, a carbonization reaction is carried out between the carbon dioxide and the calcium-containing inorganic substance in the neutralization product feed liquid, and then water removal-stabilization treatment and homogenization treatment are sequentially carried out to obtain the nano calcium carbonate microcrystal dispersion system. The nano calcium carbonate microcrystal dispersion system prepared in the present application exhibits colloidal stability and is green and safe.

Description

A nano-calcium carbonate microcrystalline dispersion system and its preparation method and application

[0001] This application claims priority to a Chinese patent application filed with the Patent Office of China on January 3, 2024, with application number CN202410004014.4 and application name “A Nano-Calcium Carbonate Microcrystalline Dispersion System, Preparation Method and Application Thereof”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to the technical field of calcium carbonate preparation, and in particular to a nano-calcium carbonate microcrystalline dispersion system, a preparation method and an application thereof. Background Art

[0003] Compared to ordinary calcium carbonate, nano-calcium carbonate exhibits changes in its crystal structure and surface electronic structure, resulting in quantum size effects, small size effects, surface effects, and macroscopic quantum effects not found in ordinary calcium carbonate. This makes it crucial in industries such as plastics, rubber, inks, lubrication, coatings, adhesives, and papermaking. Dispersions containing nano-calcium carbonate microcrystals are widely used in detergents, rust inhibitors, lubricants, and shear thickening fluids. Nano-calcium carbonate in oily media can have various structures, including calcite, vaterite, aragonite, and amorphous. The performance of nano-calcium carbonates with different structures varies significantly. Natural limestone primarily has a calcite structure. Oily nano-calcite calcium carbonate exhibits excellent non-Newtonian fluid properties, while oily nano-vaterite calcium carbonate has been less widely reported. Oily nano-amorphous calcium carbonate is the primary component of high-base detergents.

[0004] The industrial production method of nano calcium carbonate mainly adopts carbonization method, including intermittent carbonization method, continuous spray carbonization method, high gravity carbonization method etc., and the nano calcium carbonate prepared by these methods is mainly based on powder, and it is dispersed in oily medium and affects product uniformity and stability. Chinese patent CN103614903A discloses a method for preparing micro / nano calcium carbonate and shear thickening fluid thereof in situ, specifically utilizing dispersed phase calcium acetate to generate micro / nano calcium carbonate in situ in dispersion medium (one or more in ethylene glycol, polyethylene glycol, propylene glycol, hydroxy silicone oil) to obtain micro / nano calcium carbonate shear thickening fluid, which has good dispersibility, stability and shear thickening performance; However, this method is to form calcium carbonate after utilizing calcium acetate pyrolysis, and cost is higher, which is unfavorable for industrial production. Chinese patent CN113528215A discloses a method for preparing high-DBN calcium sulfonate for grease, Chinese patent CN101318915A discloses a method for preparing high-base number (TBN400) synthetic alkylbenzene calcium sulfonate, Chinese patent CN103666647A discloses a high-base number cyclopentane acid composite calcium magnesium detergent, its preparation method, and lubricating oil composition, and Chinese patent CN104450118A discloses a composite calcium sulfonate grease and a one-step preparation method thereof. However, in order to overcome the mass transfer problem of the "gas-liquid-solid" three-phase mixed system, the preparation process of the above methods requires the participation of volatile organic solvents, which does not meet green environmental protection requirements and is not conducive to safe production.

[0005] Summary of the Invention

[0006] The purpose of this application is to provide a nano-calcium carbonate microcrystal dispersion system and its preparation method and application. The method provided in this application does not require the use of volatile organic solvents, is green and safe, adopts in situ synthesis, has a high yield, and the resulting nano-calcium carbonate microcrystal dispersion system has good colloidal stability.

[0007] In order to achieve the above-mentioned invention objectives, this application provides the following technical solutions:

[0008] The present application provides a method for preparing a nano-calcium carbonate microcrystalline dispersion system, which does not use volatile organic solvents and the prepared nano-calcium carbonate microcrystalline dispersion system is colloidally stable, comprising the following steps:

[0009] Providing a mixed reaction liquid, the mixed reaction liquid comprises the following components in parts by weight: 50-80 parts of an oily dispersion medium, 5-30 parts of a main organic acid, 0.1-10 parts of an auxiliary organic acid, 0-10 parts of an inorganic acid, and 0-10 parts of a promoter;

[0010] The mixed reaction liquid is mixed with a calcium-containing inorganic substance to carry out a neutralization reaction to obtain a neutralized product liquid; the calcium-containing inorganic substance is calcium hydroxide and / or calcium oxide;

[0011] Carbon dioxide is introduced into the neutralized product liquid, and the carbon dioxide undergoes a carbonization reaction with the calcium-containing inorganic matter in the neutralized product liquid. The product is then subjected to dehydration-stabilization treatment and homogenization treatment in sequence to obtain the nano-calcium carbonate microcrystal dispersion system.

[0012] Preferably, the oily dispersion medium includes one or more of mineral oil, polyalphaolefin, alkyl naphthalene, polyether and ester synthetic oil.

[0013] Preferably, the oily dispersion medium is mineral oil, polyalphaolefin, alkyl naphthalene, polyether or ester synthetic oil.

[0014] Preferably, the oily dispersion medium is a compound of mineral oil and alkylnaphthalene, and the mass ratio of the mineral oil to the alkylnaphthalene is 1 to 10:1.

[0015] Preferably, the oily dispersion medium is a compound of polyalphaolefin and polyether, and the mass ratio of the polyalphaolefin to the polyether is 1 to 10:1.

[0016] Preferably, the oily dispersion medium is a compound of polyalphaolefin and ester synthetic oil, and the mass ratio of the polyalphaolefin to the ester synthetic oil is 5 to 20:1.

[0017] Preferably, the viscosity of the mineral oil is 40-500 mm / s.

[0018] Preferably, the viscosity of the alkyl naphthalene is 10 to 200 mm / s.

[0019] Preferably, the viscosity of the polyalphaolefin is 60-400 mm / s.

[0020] Preferably, the main organic acid comprises one or more of alkylbenzenesulfonic acid, petroleum acid, oleic acid and dodecanoic acid; the number of carbon atoms in the alkyl group of the alkylbenzenesulfonic acid is 8 to 35; the number of carbon atoms in the alkyl group of the petroleum acid is 12 to 16.

[0021] Preferably, the alkylbenzenesulfonic acid is C 12 Alkylbenzenesulfonic acid, C 20 Alkylbenzenesulfonic acid and C 24 One or more alkylbenzenesulfonic acids.

[0022] Preferably, the alkylbenzenesulfonic acid is C 12 Alkylbenzenesulfonic acid and C 20 Alkylbenzenesulfonic acid compound, the C 12 Alkylbenzenesulfonic acid and C 20 The mass ratio of alkylbenzenesulfonic acid is 0.5 to 9:1.

[0023] Preferably, the main organic acid is alkylbenzenesulfonic acid, petroleum acid, oleic acid or dodecanoic acid.

[0024] Preferably, the main organic acid is a mixture of petroleum acid and oleic acid, and the mass ratio of the petroleum acid to oleic acid is 5 to 10:1.

[0025] Preferably, the auxiliary organic acid comprises one or more of dodecyl hydroxystearic acid, stearic acid, dimer acid, oxalic acid, acetic acid, butyric acid, succinic acid, tartaric acid, malic acid, benzoic acid and salicylic acid.

[0026] Preferably, the auxiliary organic acid is dodecyl hydroxystearic acid, stearic acid, dimer acid, oxalic acid, acetic acid, butyric acid, succinic acid, tartaric acid, malic acid, benzoic acid or salicylic acid.

[0027] Preferably, the auxiliary organic acid is a mixture of dodecyl hydroxystearic acid and acetic acid, and the mass ratio of the dodecyl hydroxystearic acid to the acetic acid is 10:1-15.

[0028] Preferably, the auxiliary organic acid is a mixture of dodecyl hydroxystearic acid, tartaric acid and acetic acid, and the mass ratio of the dodecyl hydroxystearic acid, tartaric acid and acetic acid is 10:1-5:1-15.

[0029] Preferably, the auxiliary organic acid is a mixture of dodecyl hydroxystearic acid and oxalic acid, and the mass ratio of the dodecyl hydroxystearic acid to oxalic acid is 5:0.5-5.

[0030] Preferably, the inorganic acid includes one or more of boric acid, phosphoric acid and sulfuric acid.

[0031] Preferably, the accelerator includes one or more of water, dodecanol, octadecyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, glycerol and glucose.

[0032] Preferably, the accelerator is water, dodecanol, octadecyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, glycerol or glucose.

[0033] Preferably, the accelerator is a mixture of ethylene glycol and water, and the mass ratio of ethylene glycol to water is 1:1-5.

[0034] Preferably, the accelerator is a mixture of glycerol and diethylene glycol, and the mass ratio of glycerol to diethylene glycol is 1:0.1-2.

[0035] Preferably, the accelerator is a mixture of glycerol and water, and the mass ratio of glycerol to water is preferably 1:1-5.

[0036] Preferably, the mass of the calcium-containing inorganic substance is 10-30% of the mass of the mixed reaction liquid; the conditions of the neutralization reaction include: pressure of 0-5 MPa, temperature of 10-95° C., and time of 0.5-4 h.

[0037] Preferably, when the total mass of the mixed reaction liquid and the calcium-containing inorganic substance is 4-5 kg, the flow rate of the carbon dioxide is 1-50 L / min; the conditions of the carbonization reaction include: pressure of 0-5 MPa, temperature of 50-95° C., and time of 1-60 h.

[0038] Preferably, the water removal-stabilization treatment comprises:

[0039] The carbonized product system obtained after the carbonization reaction is heated to 120-180° C. at a rate of 0.5-2° C. / min, and then cooled to 80-100° C. at a rate of 0.5-2° C. / min.

[0040] Preferably, the homogenization treatment is carried out in a homogenizer, a colloid mill or a triple-roll mill.

[0041] Preferably, when the homogenization process is performed in a homogenizer, the pressure of the homogenization process is 15 to 30 MPa, and the number of times of the homogenization process is once.

[0042] The present application provides a nano-calcium carbonate microcrystal dispersion system prepared by the preparation method described in the above technical solution, wherein the particle size of the nano-calcium carbonate in the nano-calcium carbonate microcrystal dispersion system is 10 to 600 nm.

[0043] Preferably, the particle size of the nano-calcium carbonate in the nano-calcium carbonate microcrystal dispersion system is 100 to 600 nm.

[0044] Preferably, the nano calcium carbonate includes vaterite calcium carbonate or calcite calcium carbonate.

[0045] The present application provides the use of the nano-calcium carbonate microcrystalline dispersion system described in the above technical solution in lubricating grease, rust inhibitor, extreme pressure anti-wear agent or shear thickening fluid.

[0046] The present application provides a method for preparing a nano-calcium carbonate microcrystalline dispersion system, which does not use volatile organic solvents. The prepared nano-calcium carbonate microcrystalline dispersion system is colloidally stable, comprising the following steps: providing a mixed reaction liquid, wherein the mixed reaction liquid comprises the following components in parts by weight: 50 to 80 parts of an oily dispersion medium, 5 to 30 parts of a main organic acid, 0.1 to 10 parts of an auxiliary organic acid, 0 to 10 parts of an inorganic acid, and 0 to 10 parts of a promoter; mixing the mixed reaction liquid with a calcium-containing inorganic substance, performing a neutralization reaction, and obtaining a neutralized product liquid; the calcium-containing inorganic substance is calcium hydroxide and / or calcium oxide; introducing carbon dioxide into the neutralized product liquid, wherein the carbon dioxide and the calcium-containing inorganic substance in the neutralized product liquid undergo a carbonization reaction, and then sequentially undergoing a dehydration-stabilization treatment and a homogenization treatment to obtain a nano-calcium carbonate microcrystalline dispersion system. The present application uses an oily dispersion medium as a reaction medium to synthesize nano-calcium carbonate in situ, does not require the use of volatile organic solvents, is green and safe, and the resulting nano-calcium carbonate microcrystalline dispersion system has good colloid stability.

[0047] Furthermore, the present application adopts an in-situ synthesis method under mild conditions to realize the preparation of a nano-calcium carbonate microcrystalline dispersion system with an oily dispersion medium as a reaction medium, and is capable of preparing nano-calcium carbonate with different structures, such as vaterite-type calcium carbonate or calcite-type calcium carbonate, without producing by-products, with high yield, low equipment requirements, low cost and high safety, which has significant advantages in industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 is an electron microscope photograph of the nano-calcium carbonate prepared in Example 1;

[0049] FIG2 is an electron microscope photograph of the nano-calcium carbonate prepared in Example 2;

[0050] FIG3 is an electron microscope photograph of the nano-calcium carbonate prepared in Example 3;

[0051] FIG4 is an electron microscope photograph of the nano-calcium carbonate prepared in Example 4;

[0052] FIG5 is an electron microscope photograph of the nano-calcium carbonate prepared in Comparative Example 1;

[0053] FIG6 is an electron microscope photograph of the nano-calcium carbonate prepared in Comparative Example 2;

[0054] FIG7 is an infrared spectra of nano-calcium carbonate prepared in Examples 1 to 4 and Comparative Examples 1 to 3. DETAILED DESCRIPTION

[0055] The present application provides a method for preparing a nano-calcium carbonate microcrystalline dispersion system, which does not use volatile organic solvents and the prepared nano-calcium carbonate microcrystalline dispersion system is colloidally stable, comprising the following steps:

[0056] Providing a mixed reaction liquid, the mixed reaction liquid comprises the following components in parts by weight: 50-80 parts of an oily dispersion medium, 5-30 parts of a main organic acid, 0.1-10 parts of an auxiliary organic acid, 0-10 parts of an inorganic acid, and 0-10 parts of a promoter;

[0057] The mixed reaction liquid is mixed with a calcium-containing inorganic substance to carry out a neutralization reaction to obtain a neutralized product liquid; the calcium-containing inorganic substance is calcium hydroxide and / or calcium oxide;

[0058] Carbon dioxide is introduced into the neutralized product liquid, and the carbon dioxide undergoes a carbonization reaction with the calcium-containing inorganic matter in the neutralized product liquid. The product is then subjected to dehydration-stabilization treatment and homogenization treatment in sequence to obtain a nano-calcium carbonate microcrystal dispersion system.

[0059] In this application, unless otherwise specified, all raw materials used are commercially available products well known to those skilled in the art.

[0060] The method for preparing a nano-calcium carbonate microcrystalline dispersion system provided in this application does not require the use of volatile organic solvents and is environmentally friendly and safe. In this application, the volatile organic solvent specifically refers to a volatile solvent with a low flash point, preferably below 100°C and a boiling point preferably below 150°C. The volatile organic solvent includes, but is not limited to, one or more of methanol, ethanol, petroleum ether, xylene, n-butanol, and isopropanol. The method of this application is described in detail below.

[0061] The present application provides a mixed reaction solution, which comprises the following components by weight: 50-80 parts of an oily dispersion medium, 5-30 parts of a primary organic acid, 0.1-10 parts of an auxiliary organic acid, 0-10 parts of an inorganic acid, and 0-10 parts of a promoter. The mixed reaction solution is first described in detail below.

[0062] In parts by mass, the mixed reaction liquid described in the present application includes 50 to 80 parts of the oily dispersion medium, specifically 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts or 80 parts. In the present application, the oily dispersion medium preferably includes one or more of mineral oil, polyalphaolefin, alkylnaphthalene, polyether and ester synthetic oil, more preferably mineral oil, polyalphaolefin, alkylnaphthalene, polyether, ester synthetic oil, a mixture of mineral oil and alkylnaphthalene, a mixture of polyalphaolefin and polyether or a mixture of polyalphaolefin and ester synthetic oil; when the oily dispersion medium is a mixture of mineral oil and alkylnaphthalene, the mass ratio of the mineral oil to the alkylnaphthalene is preferably 1 to 10:1, more preferably 1.5 to 5:1, and further preferably 2:1; when the oily dispersion medium is a mixture of polyalphaolefin and polyether, the mass ratio of the polyalphaolefin to the polyether is preferably 1 to 10:1, more preferably 4 to 6:1, and further preferably 5:1; when the oily dispersion medium is a mixture of polyalphaolefin and ester synthetic oil, the mass ratio of the polyalphaolefin to the ester synthetic oil is preferably 5 to 20:1, more preferably 8 to 12:1, and further preferably 10:1. In the present application, the viscosity of the mineral oil is preferably 40-500 mm / s, more preferably 80-200 mm / s, and even more preferably 100 mm / s; the mineral oil described in the examples of the present application is purchased from ExxonMobil. In the present application, the viscosity of the polyalphaolefin is preferably 60-400 mm / s, more preferably 65-200 mm / s, and even more preferably 70-100 mm / s; the polyalphaolefin described in the examples of the present application is purchased from ExxonMobil. In the present application, the viscosity of the alkyl naphthalene is preferably 10-200 mm / s, more preferably 80-150 mm / s, and even more preferably 100 mm / s; the alkyl naphthalene described in the examples of the present application is purchased from King Industries, Inc., USA. The polyether described in the examples of the present application is purchased from Dow Chemical Company; the ester synthetic oil polyether is purchased from Croda Corporation. The present application preferably uses the above-mentioned type of oily dispersion medium, which has good solubility or dispersibility and can effectively dissolve or disperse each component, which is conducive to maintaining good uniformity of the reaction system and ensuring the smooth progress of the reaction, thereby ultimately obtaining a nano-calcium carbonate microcrystalline dispersion system with excellent stability.

[0063] Based on the mass fraction of the oily dispersion medium, the mixed reaction liquid described in the present application includes 5 to 30 parts of the main organic acid, specifically 5 parts, 10 parts, 15 parts, 20 parts, 25 parts or 30 parts. In the present application, the main organic acid preferably includes one or more of alkylbenzenesulfonic acid, petroleum acid, oleic acid and dodecanoic acid, specifically alkylbenzenesulfonic acid, petroleum acid, oleic acid or dodecanoic acid, or a compound of petroleum acid and oleic acid; when the main organic acid is a compound of petroleum acid and oleic acid, the mass ratio of the petroleum acid to oleic acid is preferably 5 to 10:1, more preferably 8 to 9.5:1, and further preferably 9:1. In the present application, the number of carbon atoms in the alkylbenzenesulfonic acid is preferably 8 to 35, specifically 8 to 14 (i.e., C 8～14 Alkylbenzenesulfonic acid), can also be 16 to 35 (ie C 16～35 Alkylbenzenesulfonic acid), more preferably C 12 Alkylbenzenesulfonic acid, C 20 Alkylbenzenesulfonic acid and C 24 One or more of the alkylbenzene sulfonic acids, specifically C 12 Alkylbenzenesulfonic acid and C 20 Alkylbenzenesulfonic acid compound, can also be C 24 Alkylbenzenesulfonic acid; when the alkylbenzenesulfonic acid is C 12 Alkylbenzenesulfonic acid and C 20 When the alkylbenzene sulfonic acid compound is used, the C 12 Alkylbenzenesulfonic acid and C 20 The mass ratio of alkylbenzene sulfonic acid is preferably 0.5-9:1, more preferably 0.8-2:1, and even more preferably 1:1. The alkylbenzene sulfonic acid described in this application is purchased from Jintong Petrochemical Company. In this application, the number of carbon atoms in the alkyl group of the petroleum acid is preferably 16-20. The petroleum acid described in the examples of this application is purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. The oleic acid described in the examples of this application is purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; dodecanoic acid is purchased from Jintong Petrochemical Company. The present application preferably uses the above-mentioned type of main organic acid, which can react with calcium-containing inorganic substances (calcium hydroxide and / or calcium oxide) to form organic acid calcium. The organic acid calcium is a surfactant, one end of which is hydrophilic (i.e., the polar end) and the other end is lipophilic (i.e., the non-polar end). During the subsequent carbonization reaction, the calcium-containing inorganic substances present in the neutralized product liquid react with carbon dioxide to form calcium carbonate. The polar end of the organic acid calcium is adsorbed to the surface of the calcium carbonate to form a micelle, and the non-polar end is on the outside, merging with the oily dispersion medium of the system, and finally forming a stable nano-calcium carbonate microcrystalline dispersion system.

[0064] Based on the mass fraction of the oily dispersion medium, the mixed reaction liquid described in the present application includes 0.1 to 10 parts of auxiliary organic acid, specifically 0.1 part, 0.5 part, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts or 10 parts. In the present application, the auxiliary organic acid preferably includes one or more of dodecyl hydroxystearic acid, stearic acid, dimer acid, oxalic acid, acetic acid, butyric acid, succinic acid, tartaric acid, malic acid, benzoic acid and salicylic acid, specifically dodecyl hydroxystearic acid, stearic acid, dimer acid, oxalic acid, acetic acid, butyric acid, succinic acid, tartaric acid, malic acid, benzoic acid or salicylic acid, and can be a compound of dodecyl hydroxystearic acid and acetic acid, or a compound of dodecyl hydroxystearic acid, tartaric acid and acetic acid, or a compound of dodecyl hydroxystearic acid and oxalic acid; when the auxiliary organic acid is a compound of dodecyl hydroxystearic acid and acetic acid, the dodecyl hydroxystearic acid and acetic acid are preferably selected from the group consisting of: The mass ratio of acetic acid is preferably 10:1-15, more preferably 10:1.5-5, and further preferably 10:2-3; when the auxiliary organic acid is a compound of dodecyl hydroxystearic acid, tartaric acid and acetic acid, the mass ratio of dodecyl hydroxystearic acid, tartaric acid and acetic acid is preferably 10:1-5:1-15, more preferably 10:4-5:1.2-3, and further preferably 10:5:1.5; when the auxiliary organic acid is a compound of dodecyl hydroxystearic acid and oxalic acid, the mass ratio of dodecyl hydroxystearic acid to oxalic acid is preferably 5:0.5-5, more preferably 5:0.8-2, and further preferably 5:1. The present application preferably uses the above-mentioned types of auxiliary organic acids, which can assist the main organic acid to react rapidly, which is beneficial to maintaining good stability of the reaction system, thereby ultimately obtaining a nano-calcium carbonate microcrystal dispersion system with excellent stability.

[0065] Based on the mass fraction of the oily dispersion medium, the mixed reaction liquid described in the present application includes 0 to 10 parts of inorganic acid, specifically 0.1 part, 0.5 part, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts or 10 parts. In the present application, the inorganic acid preferably includes one or more of boric acid, phosphoric acid and sulfuric acid, more preferably boric acid, phosphoric acid or sulfuric acid. The present application preferably uses the above-mentioned types of inorganic acids, which can assist the main organic acid to react rapidly, which is beneficial to maintaining good stability of the reaction system, thereby ultimately obtaining a nano-calcium carbonate microcrystal dispersion system with excellent stability.

[0066] Based on the mass fraction of the oily dispersion medium, the mixed reaction liquid described in the present application includes 0 to 10 parts of the promoter, specifically 0.1 parts, 0.5 parts, 1 parts, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts or 10 parts. In the present application, the accelerator preferably includes one or more of water, dodecanol, octadecanol, ethylene glycol, diethylene glycol, triethylene glycol, glycerol and glucose, and can be water, dodecanol, octadecanol, ethylene glycol, diethylene glycol, triethylene glycol, glycerol or glucose, and can be a compound of ethylene glycol and water, or a compound of glycerol and diethylene glycol, or a compound of glycerol and water; when the accelerator is a compound of ethylene glycol and water, the mass ratio of the ethylene glycol to water is preferably The mass ratio of glycerol to diethylene glycol is preferably 1:1-5, more preferably 1:1.5-2.5, and further preferably 1:2; when the accelerator is a mixture of glycerol and diethylene glycol, the mass ratio of glycerol to diethylene glycol is preferably 1:0.1-2, more preferably 1:0.5-1.5, and further preferably 1:1; when the accelerator is a mixture of glycerol and water, the mass ratio of glycerol to water is preferably 1:1-5, more preferably 1:1.5-2.5, and further preferably 1:2. In the present application, the accelerator can be used as a catalyst for a solid-liquid-gas three-phase reaction system, which is beneficial to increasing the reaction rate; the present application preferably uses the above-mentioned small molecule polar compounds as accelerators, which is beneficial to accelerating the reaction speed of the reaction system and improving the reaction effect.

[0067] The present application preferably mixes the components of the mixed reaction solution to obtain the mixed reaction solution; the present application does not particularly limit the order of adding the components in the mixed reaction solution and the mixing method, as long as the components can be fully dispersed or dissolved. In the embodiments of the present application, the components are specifically mixed uniformly under stirring and / or heating conditions to obtain the mixed reaction system.

[0068] After obtaining the mixed reaction liquid, the present application mixes the mixed reaction liquid with a calcium-containing inorganic substance, performs a neutralization reaction, and obtains a neutralized product liquid; the calcium-containing inorganic substance is calcium hydroxide and / or calcium oxide. In the present application, the mass of the calcium-containing inorganic substance is preferably 10 to 30% of the mass of the mixed reaction liquid, more preferably 13 to 25%, further preferably 14 to 24%, further preferably 16 to 22%, and further preferably 17 to 21%. The present application preferably adds the calcium-containing inorganic substance to the mixed reaction liquid, and more preferably adds the calcium-containing inorganic substance to the mixed reaction liquid in batches to ensure that the material is quickly and evenly dispersed; the present application does not specifically limit the number of times the calcium-containing inorganic substance is added and the amount added each time. In the present application, the conditions for the neutralization reaction include: a pressure of preferably 0 to 5 MPa, more preferably 0.05 to 2 MPa, further preferably 0.08 to 1 MPa, and further preferably 0.1 to 0.6 MPa; a temperature of preferably 10 to 95°C, more preferably 30 to 80°C, further preferably 40 to 60°C, and further preferably 50°C; and a time of preferably 0.5 to 4 hours, more preferably 1 to 2 hours. The present application allows the neutralization reaction to be carried out at a higher temperature, which is beneficial for increasing the reaction rate. In the present application, during the neutralization reaction, the organic acid reacts with a calcium-containing inorganic substance (calcium hydroxide and / or calcium oxide) to generate an organic acid calcium. The organic acid calcium is a surfactant having a hydrophilic end (i.e., a polar end) and a lipophilic end (i.e., a non-polar end). During the subsequent carbonization reaction, the calcium-containing inorganic substance present in the neutralization product liquid (the initial amount of the calcium-containing inorganic substance added before the neutralization reaction is excessive, or the substance is added again after the neutralization reaction; when the calcium-containing inorganic substance is calcium oxide, it reacts with water in the system to generate calcium hydroxide and participate in the carbonization reaction) reacts with carbon dioxide to generate calcium carbonate. The polar end of the organic acid calcium is adsorbed to the surface of the calcium carbonate to form a micelle, and the non-polar end is on the outside and merges with the oily dispersion medium of the system to eventually form a stable nano-calcium carbonate microcrystal dispersion system.

[0069] After obtaining the neutralized product feed liquid, the present application introduces carbon dioxide into the neutralized product feed liquid, and the carbon dioxide undergoes a carbonization reaction with the calcium-containing inorganic substance in the neutralized product feed liquid, and then sequentially undergoes a dehydration-stabilization treatment and a homogenization treatment to obtain a nano-calcium carbonate microcrystal dispersion system. In the present application, when the total mass of the mixed reaction liquid and the calcium-containing inorganic substance is 4 to 5 kg, the flow rate of the carbon dioxide is preferably 1 to 50 L / min, more preferably 3 to 40 L / min, more preferably 5 to 30 L / min, further preferably 8 to 20 L / min, and even more preferably 10 to 12 L / min; in an embodiment of the present application, the carbon dioxide is specifically introduced into the neutralized product feed liquid by a gas dispersion device. In the present application, the conditions of the carbonization reaction include: the pressure is preferably 0-5 MPa, more preferably 0.05-3 MPa, further preferably 0.08-2 MPa, and further preferably 0.1-1 MPa; the temperature is preferably 50-95°C, more preferably 60-85°C, and further preferably 70-80°C; the time of the carbonization reaction is preferably 1-60 h, more preferably 3-40 h, further preferably 5-30 h, further preferably 8-20 h, and further preferably 13-18 h. During the carbonization reaction described in the present application, the infrared and alkalinity of the reaction system are regularly detected. When the alkalinity is 0-20, the introduction of carbon dioxide is stopped, the carbonization reaction is terminated, and a carbonized product liquid is obtained; the present application preferably monitors whether calcium carbonate is generated and its structural changes in the reaction system by measuring the infrared of the reaction system. The present application can carry out the carbonization reaction under higher temperature conditions, which is conducive to increasing the reaction rate. In the present application, during the carbonization reaction, the calcium hydroxide in the system captures carbon dioxide in situ to generate nano-calcium carbonate.

[0070] After the carbonization reaction, the present application sequentially carries out a dehydration-stabilization treatment and a homogenization treatment on the carbonized product liquid to obtain a nano-calcium carbonate microcrystalline dispersion system. In the present application, the dehydration-stabilization treatment preferably includes: heating the carbonized product system obtained after the carbonization reaction to 120-180°C at a rate of 0.5-2°C / min, and then cooling it to 80-100°C at a rate of 0.5-2°C / min. In the present application, the heating rate is preferably 0.5-2°C / min, more preferably 1-1.5°C / min, and further preferably 1-1.2°C / min; the heating process is preferably carried out under normal pressure; during the heating process, water in the carbonized product liquid (including water generated during the reaction or water added as a promoter) will be removed, and the structure of the generated nano-calcium carbonate will be stabilized; the present application preferably controls the heating rate within the above range, which is conducive to ensuring the safety of production. If the heating rate is too fast, there is a risk of overflowing the kettle. The present application preferably heats the material to 120-180°C at the above-mentioned heating rate, further preferably heats the material to 150-160°C, and further preferably heats the material to 140°C; if the temperature is too high, the material is easily oxidized at high temperature, and the energy consumption is high; if the temperature is too low, the dehydration rate is slow, and it is easy to cause incomplete water removal. In the present application, the cooling rate is preferably 0.5-2°C, more preferably 1-1.5°C; the temperature of the material after cooling is preferably 80-100°C, more preferably 80-90°C; the present application preferably cools the material at the above-mentioned rate, and the cooling efficiency is high, which avoids the oxidation of the material due to long high temperature time. After the dehydration-stabilization treatment, the present application homogenizes the obtained liquid, and the homogenization treatment can refine the liquid and obtain a uniform and consistent nano-calcium carbonate microcrystal dispersion system. The present application preferably uses a homogenizer, a colloid mill or a three-roll mill to homogenize the liquid after dehydration and stabilization treatment; in the embodiments of the present application, taking the use of a homogenizer for homogenization as an example, the pressure of the homogenization treatment is preferably 15 to 30 MPa, more preferably 20 to 25 MPa; the number of times the homogenization treatment is performed is preferably once.

[0071] The present application provides a nano-calcium carbonate microcrystal dispersion system prepared by the preparation method described in the above technical solution, wherein the particle size of the nano-calcium carbonate in the nano-calcium carbonate microcrystal dispersion system is 10 to 600 nm, specifically 100 to 200 nm, 100 to 500 nm or 400 to 600 nm. In the present application, the nano-calcium carbonate preferably comprises vaterite calcium carbonate or calcite calcium carbonate; the particle size of the vaterite calcium carbonate is preferably 100 to 500 nm, more preferably 100 to 200 nm; the particle size of the calcite calcium carbonate is preferably 100 to 200 nm. The nano-calcium carbonate microcrystal dispersion system described in the present application has good colloidal stability, and when the nano-calcium carbonate is vaterite calcium carbonate or calcite calcium carbonate, the nano-calcium carbonate microcrystal dispersion system has non-Newtonian fluid properties.

[0072] This application provides the application of the nano-calcium carbonate microcrystalline dispersion system described in the above technical solution in lubricating grease, rust inhibitor, extreme pressure anti-wear agent or shear thickening fluid. This application does not specifically limit the specific application of the nano-calcium carbonate microcrystalline dispersion system, and methods well known to those skilled in the art can be used.

[0073] The following will be combined with the embodiments of this application to clearly and completely describe the technical solutions in this application. Obviously, the embodiments described are only some of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0074] The sources of some raw materials in the following examples and comparative examples are as follows:

[0075] Mineral oil was purchased from ExxonMobil; polyalphaolefins were purchased from ExxonMobil; alkyl naphthalene was purchased from King Industries, Inc.; polyether was purchased from Dow Chemical; ester synthetic oil polyether was purchased from Croda Corporation; alkylbenzene sulfonic acid was purchased from Jintong Petrochemical Company; petroleum acid was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; oleic acid was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; and dodecanoic acid was purchased from Jintong Petrochemical Company.

[0076] Example 1

[0077] (1) Add 2000g of mineral oil with a viscosity of 100mm / s and 1000g of alkyl naphthalene with a viscosity of 100mm / s into the reactor, and then add 200g of C 12 Alkylbenzenesulfonic acid, 200g C 20 Alkylbenzenesulfonic acid, 150g of dodecyl hydroxystearic acid, 75g of boric acid and 40g of water were stirred to dissolve and disperse the components uniformly to obtain a mixed reaction liquid;

[0078] (2) heating the mixed reaction liquid to 50° C., adding 500 g of calcium hydroxide in batches, stirring and mixing uniformly, and conducting a neutralization reaction at normal pressure (specifically 1 atmosphere, 0.1013 MPa) and 50° C. for 2 h to obtain a neutralized product liquid;

[0079] (3) introducing carbon dioxide into the neutralized product liquid at a rate of 8 L / min under normal pressure to carry out a carbonization reaction, controlling the system temperature to 85°C during the ventilation process, and the ventilation time to 8 hours; after the ventilation is completed, the system temperature is raised to 140°C at a heating rate of 1°C / min to remove water from the system, and then cooled to 80°C at a cooling rate of 1°C / min, and the obtained liquid is homogenized once at a pressure of 25 MPa using a homogenizer to obtain a nano-calcium carbonate microcrystalline dispersion system with a stable structure and non-Newtonian fluid properties.

[0080] Example 2

[0081] (1) Add 2000g of mineral oil with a viscosity of 100mm / s into the reactor, and then add 1000g of C 20 Alkylbenzenesulfonic acid, 100g of dodecyl hydroxystearic acid, 20g of ethylene glycol, 40g of water, 30g of acetic acid and 30g of phosphoric acid were stirred to dissolve and disperse the components uniformly to obtain a mixed reaction liquid;

[0082] (2) heating the mixed reaction liquid to 50° C., adding 800 g of calcium hydroxide, stirring and mixing uniformly, and conducting a neutralization reaction at normal pressure and 50° C. for 1 h to obtain a neutralized product liquid;

[0083] (3) introducing carbon dioxide into the neutralized product liquid at a rate of 12 L / min under normal pressure to carry out a carbonization reaction, controlling the system temperature to 70°C during the ventilation process, and the ventilation time to 13 h; after the ventilation is completed, the system temperature is raised to 180°C at a heating rate of 1.2°C / min to remove water from the system, and then cooled to 80°C at a cooling rate of 1°C / min, and the obtained liquid is homogenized once at a pressure of 25 MPa using a homogenizer to obtain a nano-calcium carbonate microcrystalline dispersion system with a stable structure and non-Newtonian fluid properties.

[0084] Example 3

[0085] (1) Add 2500g of polyalphaolefin with a viscosity of 70mm / s and 500g of polyether into the reactor, and then add 700g of C 24 alkylbenzenesulfonic acid, 100g of dodecyl hydroxystearic acid, 50g of tartaric acid, 15g of sulfuric acid, 15g of acetic acid, 10g of glycerol and 10g of diethylene glycol, stirring to dissolve and evenly disperse the components to obtain a mixed reaction liquid;

[0086] (2) heating the mixed reaction liquid to 50° C., adding 650 g of calcium hydroxide, stirring and mixing uniformly, and conducting a neutralization reaction at normal pressure and 50° C. for 2 h to obtain a neutralized product liquid;

[0087] (3) introducing carbon dioxide into the neutralized product liquid at a rate of 8 L / min under normal pressure to carry out a carbonization reaction, controlling the system temperature to 85°C during the ventilation process, and the ventilation time to 18 h; after the ventilation is completed, the system temperature is raised to 160°C at a heating rate of 1°C / min to remove water from the system, and then cooled to 80°C at a cooling rate of 1°C / min, and the resulting liquid is homogenized once at a pressure of 25 MPa using a homogenizer to obtain a nano-calcium carbonate microcrystalline dispersion system with a stable structure and non-Newtonian fluid properties.

[0088] Example 4

[0089] (1) Add 2000g of polyalphaolefin with a viscosity of 100mm / s and 200g of ester synthetic oil into the reactor, and then add 900g of C 16-20 Petroleum acid, 100g oleic acid, 150g dodecyl hydroxystearic acid, 30g oxalic acid, 30g sulfuric acid and 40g water, stirring to dissolve and disperse the components uniformly to obtain a mixed reaction liquid;

[0090] (2) heating the mixed reaction liquid to 50° C., adding 750 g of calcium hydroxide, stirring and mixing uniformly, and conducting a neutralization reaction at a pressure of 0.6 MPa and a temperature of 50° C. for 1 h to obtain a neutralized product liquid;

[0091] (3) introducing carbon dioxide into the neutralized product liquid at a rate of 8 L / min under a pressure of 1 MPa to carry out a carbonization reaction, controlling the system temperature to 80°C during the ventilation process, and the ventilation time to 8 hours; after the ventilation is completed, the system temperature is raised to 140°C at a heating rate of 1°C / min under normal pressure to remove water from the system, and then cooled to 80°C at a cooling rate of 1°C / min, and the resulting liquid is homogenized once at a pressure of 25 MPa using a homogenizer to obtain a nano-calcium carbonate microcrystalline dispersion system with a stable structure and non-Newtonian fluid properties.

[0092] Comparative Example 1

[0093] (1) Add 2000g of mineral oil with a viscosity of 100mm / s and 1000g of polyalphaolefin with a viscosity of 100mm / s into the reactor, then add 1000g of C 20-24 Alkylbenzenesulfonic acid, 400g petroleum ether, 75g boric acid, 40g water and 150g methanol were stirred to dissolve and disperse the components uniformly to obtain a mixed solution;

[0094] (2) heating the mixed solution to 50° C., adding 500 g of calcium hydroxide, stirring and mixing uniformly, and conducting a neutralization reaction at 50° C. for 2 h to obtain a neutralized product solution;

[0095] (3) carbon dioxide was introduced into the neutralized product liquid at a rate of 8 L / min, and the system temperature was controlled to be 45°C during the ventilation process, and the ventilation time was 10 h; after the ventilation was completed, the system temperature was raised to 140°C at a heating rate of 1°C / min to remove water from the system, and then the temperature was lowered to 80°C at a cooling rate of 1°C / min, and the obtained liquid was homogenized once at a pressure of 25 MPa using a homogenizer to obtain a nano-calcium carbonate dispersion system with non-Newtonian fluid properties.

[0096] Comparative Example 2

[0097] (1) Add 1500g of mineral oil with a viscosity of 100mm / s and 1500g of polyalphaolefin with a viscosity of 100mm / s into the reactor, then add 1000g of high base calcium carbonate (base value is 400DBN), 100g of water, 100g of C 12 Alkylbenzenesulfonic acid, 30g n-butanol, 30g acetic acid and 150g methanol were stirred to dissolve and disperse the components uniformly, and the resulting mixed solution was heated to 85°C and kept warm for 2h for crystal transformation;

[0098] (2) After the crystal transformation is completed, the obtained system is heated to 100°C and 100g of calcium hydroxide, 30g of boric acid and 60g of dodecyl stearic acid are added, stirred evenly and reacted at 100°C for 1h;

[0099] (3) After the reaction is completed, the obtained system is heated to 160°C at a heating rate of 1°C / min to remove water from the system, and then cooled to 80°C at a cooling rate of 1°C / min. The obtained liquid is homogenized once at a pressure of 25 MPa using a homogenizer to obtain a nano-calcium carbonate dispersion system with non-Newtonian fluid properties.

[0100] Comparative Example 3

[0101] (1) Add 800 g of mineral oil with a viscosity of 30 mm / s to a reactor, then add 1200 g of heavy alkylbenzenesulfonic acid (the number of carbon atoms in the alkyl group is 18 to 24), 160 g of methanol, and 2000 g of calcium hydroxide in sequence, stir to dissolve and disperse the components uniformly, heat the resulting mixed solution to 45°C, and react under heat preservation conditions for 0.5 h;

[0102] (2) After the reaction is completed, carbon dioxide is introduced into the obtained system at a rate of 2 L / min. During the aeration process, samples are taken to test the alkalinity. When the alkalinity reaches above 350, aeration is stopped.

[0103] (3) After the ventilation is completed, the obtained system is centrifuged, and the obtained liquid material is heated to 110° C. for flash evaporation to remove the solvent and water. After cooling, it is filtered, and the filtrate is collected as a nano-calcium carbonate dispersion system with Newtonian characteristics.

[0104] Characterization and performance testing

[0105] Figure 1 is an electron micrograph of the nano-calcium carbonate prepared in Example 1, Figure 2 is an electron micrograph of the nano-calcium carbonate prepared in Example 2, Figure 3 is an electron micrograph of the nano-calcium carbonate prepared in Example 3, Figure 4 is an electron micrograph of the nano-calcium carbonate prepared in Example 4, Figure 5 is an electron micrograph of the nano-calcium carbonate prepared in Comparative Example 1, and Figure 6 is an electron micrograph of the nano-calcium carbonate prepared in Comparative Example 2. The particle sizes of the nano-calcium carbonates prepared in Examples 1 to 4 and Comparative Examples 1 to 3 are specifically shown in Table 1. The results show that the particle size of the nano-calcium carbonate prepared by the method of the present application is uniform and has good controllability, and the particle size of the nano-calcium carbonate prepared by the methods of Comparative Examples 1 to 3 is also relatively uniform.

[0106] FIG7 is an infrared spectrum of the nano-calcium carbonate prepared in Examples 1 to 4 and Comparative Examples 1 to 3, wherein the infrared characteristic peak positions of the nano-calcium carbonate prepared in Examples 1 to 4 and Comparative Examples 1 to 3 are specifically shown in Table 1. The results show that the infrared characteristic peak positions of nano-calcium carbonates with different structures are different, with clear distinction. For example, the vaterite-type calcium carbonate prepared in Examples 1 and 3 to 4 has an infrared characteristic peak at 875 to 876 cm -1 ; Example 2 and Comparative Examples 1 to 2 prepared calcite-type calcium carbonate, infrared characteristic peaks of 883 to 885 cm -1 Comparative Example 3 prepared amorphous calcium carbonate, infrared characteristic peak is 862cm -1 .

[0107] The nano-calcium carbonate prepared in Examples 1 to 4 and Comparative Examples 1 to 3 was tested, and the specific results are shown in Table 1, wherein the cone penetration was tested according to the GB / T 269 method, and the dropping point was tested according to the GB / T 3498 method; the yields of the nano-calcium carbonate prepared in Examples 1 to 4 and Comparative Examples 1 to 3 are also listed in Table 1. As can be seen from Table 1, Comparative Examples 1 to 3 all use volatile organic solvents in the preparation process, which does not meet the green environmental protection requirements and is not conducive to safe production. Among them, Comparative Example 1 has a low product yield due to the use of volatile organic solvents; Comparative Example 2 does not use an in-situ method to prepare calcium carbonate, but uses a conventional crystal transformation method to prepare calcium carbonate, which also requires the use of volatile organic solvents and cannot flexibly control the type of calcium carbonate crystals; Comparative Example 3 is a conventional method for preparing amorphous calcium carbonate, and the use of volatile organic solvents results in a low product yield. Examples 1 to 4 of the present application do not use volatile organic solvents during the preparation process, are safe and environmentally friendly, and can prepare nano calcium carbonate with different structures, such as vaterite-type calcium carbonate and calcite-type calcium carbonate, without producing by-products and with high yield.

[0108] Table 1 Test results of nano calcium carbonate prepared in Examples 1 to 4 and Comparative Examples 1 to 3

[0109] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A preparation method of a nano-calcium carbonate microcrystal dispersion system, characterized in that Without using volatile organic solvents, a colloidal stable nano-calcium carbonate microcrystal dispersion system is prepared, including the following steps: Provide a mixed reaction solution, which includes the following components in parts by mass: 50 - 80 parts of an oily dispersion medium, 5 - 30 parts of a main organic acid, 0.1 - 10 parts of an auxiliary organic acid, 0 - 10 parts of an inorganic acid, and 0 - 10 parts of a promoter; Mix the mixed reaction solution with a calcium-containing inorganic substance to carry out a neutralization reaction to obtain a neutralized product liquid; the calcium-containing inorganic substance is calcium hydroxide and / or calcium oxide; Introduce carbon dioxide into the neutralized product liquid, and the carbon dioxide reacts with the calcium-containing inorganic substance in the neutralized product liquid to carry out a carbonization reaction, and then successively through water removal - stabilization treatment and homogenization treatment to obtain the nano-calcium carbonate microcrystal dispersion system.

2. The preparation method according to claim 1, characterized in that, The oily dispersion medium includes one or more of mineral oil, polyalphaolefin, alkylnaphthalene, polyether, and ester synthetic oil.

3. The preparation method according to claim 2, wherein The oily dispersion medium is mineral oil, polyalphaolefin, alkylnaphthalene, polyether, or ester synthetic oil.

4. The preparation method according to claim 2, characterized in that, The oily dispersion medium is a compound of mineral oil and alkylnaphthalene, and the mass ratio of the mineral oil to the alkylnaphthalene is 1 - 10:

1.

5. The preparation method according to claim 2, characterized in that, The oily dispersion medium is a compound of polyalphaolefin and polyether, and the mass ratio of the polyalphaolefin to the polyether is 1 - 10:

1.

6. The preparation method according to claim 2, characterized in that, The oily dispersion medium is a compound of polyalphaolefin and ester synthetic oil, and the mass ratio of the polyalphaolefin to the ester synthetic oil is 5 - 20:

1.

7. The preparation method according to any one of claims 2 to 4, characterized in that, The viscosity of the mineral oil is 40 - 500 mm / s.

8. The preparation method according to any one of claims 2 to 4, characterized in that, The viscosity of the alkylnaphthalene is 10 - 200 mm / s.

9. The preparation method according to claim 2, 3, 5 or 6, characterized in that, The viscosity of the polyalphaolefin is 60 - 400 mm / s.

10. The preparation method according to claim 1, wherein The main organic acid includes one or more of alkylbenzenesulfonic acid, petroleum acid, oleic acid, and dodecanoic acid; the number of carbon atoms in the alkyl group of the alkylbenzenesulfonic acid is 8 - 35; the number of carbon atoms in the alkyl group of the petroleum acid is 16 - 20.

11. The preparation method according to claim 10, characterized in that, The alkylbenzenesulfonic acid is C 12 alkylbenzenesulfonic acid, C 20 alkylbenzenesulfonic acid, and C 24 one or more of alkylbenzenesulfonic acids.

12. The preparation method according to claim 11, characterized in that, The alkylbenzenesulfonic acid is C 12 alkylbenzenesulfonic acid and C 20 alkylbenzenesulfonic acid complex, and the C 12 alkylbenzenesulfonic acid and C 20 mass ratio of alkylbenzenesulfonic acid to C alkylbenzenesulfonic acid is 0.5 to 9:

1.

13. The preparation method according to any one of claims 10 to 12, characterized in that, The main organic acid is alkylbenzenesulfonic acid, petroleum acid, oleic acid, or dodecanoic acid.

14. The preparation method according to claim 10, wherein The main organic acid is a compound of petroleum acid and oleic acid, and the mass ratio of the petroleum acid to the oleic acid is 5 - 10:

1.

15. The preparation method according to claim 1, wherein, The auxiliary organic acid includes one or more of 12 - hydroxystearic acid, stearic acid, dimer acid, oxalic acid, acetic acid, butyric acid, succinic acid, tartaric acid, malic acid, benzoic acid, and salicylic acid.

16. The preparation method according to claim 15, wherein The auxiliary organic acid is 12 - hydroxystearic acid, stearic acid, dimer acid, oxalic acid, acetic acid, butyric acid, succinic acid, tartaric acid, malic acid, benzoic acid, or salicylic acid.

17. The preparation method according to claim 15, wherein The auxiliary organic acid is a compound of 12 - hydroxystearic acid and acetic acid, and the mass ratio of the 12 - hydroxystearic acid to the acetic acid is 10:1 - 15.

18. The preparation method according to claim 15, wherein, The auxiliary organic acid is a compound of 12 - hydroxystearic acid, tartaric acid, and acetic acid, and the mass ratio of the 12 - hydroxystearic acid, tartaric acid, and acetic acid is 10:1 - 5:1 - 15.

19. The preparation method according to claim 15, characterized in that, The auxiliary organic acid is a compound of 12 - hydroxystearic acid and oxalic acid, and the mass ratio of the 12 - hydroxystearic acid to the oxalic acid is 5:0.5 - 5.

20. The preparation method according to claim 1, characterized in that, The inorganic acid includes one or more of boric acid, phosphoric acid, and sulfuric acid.

21. The preparation method according to claim 1, wherein, The promoter includes one or more of water, dodecanol, octadecanol, ethylene glycol, diethylene glycol, triethylene glycol, glycerol, and glucose.

22. The preparation method according to claim 21, characterized in that, The promoter is water, dodecanol, octadecanol, ethylene glycol, diethylene glycol, triethylene glycol, glycerol or glucose.

23. The preparation method according to claim 21, wherein The promoter is a mixture of ethylene glycol and water, and the mass ratio of ethylene glycol to water is 1:1 to 5.

24. The preparation method according to claim 21, wherein The promoter is a mixture of glycerol and diethylene glycol, and the mass ratio of glycerol to diethylene glycol is 1:0.1 to 2.

25. The preparation method according to claim 21, wherein The promoter is a mixture of glycerol and water, and the mass ratio of glycerol to water is preferably 1:1 to 5.

26. The preparation method according to claim 1, characterized in that, The mass of the calcium-containing inorganic substance is 10 to 30% of the mass of the mixed reaction solution; the conditions of the neutralization reaction include: pressure of 0 to 5 MPa, temperature of 10 to 95 °C, and time of 0.5 to 4 h.

27. The preparation method according to claim 1, characterized in that, When the total mass of the mixed reaction solution and the calcium-containing inorganic substance is 4 to 5 kg, the feeding rate of carbon dioxide is 1 to 50 L / min; the conditions of the carbonization reaction include: pressure of 0 to 5 MPa, temperature of 50 to 95 °C, and time of 1 to 60 h.

28. The preparation method according to claim 1 or 27, characterized in that, The dehydration-stabilization treatment includes: heating the carbonized product system obtained after the carbonization reaction to 120 to 180 °C at a rate of 0.5 to 2 °C / min, and then cooling it to 80 to 100 °C at a rate of 0.5 to 2 °C / min.

29. The preparation method according to claim 1, characterized in that, The homogenization treatment is carried out in a homogenizer, a colloid mill or a three-roll mill.

30. The preparation method according to claim 29, wherein When the homogenization treatment is carried out in a homogenizer, the pressure of the homogenization treatment is 15 to 30 MPa, and the number of times of the homogenization treatment is one.

31. The nano-calcium carbonate microcrystal dispersion system prepared by the preparation method according to any one of claims 1 to 30, wherein the particle size of the nano-calcium carbonate in the nano-calcium carbonate microcrystal dispersion system is 10 to 600 nm.

32. The nano calcium carbonate microcrystal dispersion system according to claim 31, wherein The particle size of the nano-calcium carbonate in the nano-calcium carbonate microcrystal dispersion system is 100 to 600 nm.

33. The nano calcium carbonate microcrystal dispersion system according to claim 31 or 32, characterized in that, The nano-calcium carbonate includes vaterite-type calcium carbonate or calcite-type calcium carbonate.

34. The application of the nano-calcium carbonate microcrystal dispersion system according to any one of claims 31 to 33 in lubricating grease, rust inhibitor, extreme pressure anti-wear agent or shear thickening fluid.

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