Continuous preparation method of maleic anhydride modified Fischer-Tropsch wax and application of maleic anhydride modified Fischer-Tropsch wax in emulsion explosive

Abstract

The invention discloses a continuous preparation method of high-polarity maleic anhydride modified Fischer-Tropsch wax (FT-g-MAH) and application of the high-polarity maleic anhydride modified Fischer-Tropsch wax in composite wax for emulsion explosive. According to the method, Fischer-Tropsch wax is used as a matrix, maleic anhydride (MAH) is used as a grafting monomer, and in the presence of an initiator and an auxiliary agent, the FT-g-MAH with the grafting rate not lower than 6.5% is prepared through a CSTR continuous synthesis melt grafting process. According to the invention, through continuous reaction and optimized process parameters, a strong polar anhydride group is introduced to a Fischer-Tropsch wax molecular chain, so that the Fischer-Tropsch wax has amphipathy. As a key component of the composite wax for the emulsion explosive, the obtained FT-g-MAH can replace or reduce a traditional emulsifier, spontaneously acts on an oil-water interface, the emulsification effect is remarkably improved, and the storage stability and detonation performance of the emulsion explosive are improved. Compared with the FT-g-MAH prepared by the traditional intermittent process, the product disclosed by the invention has the advantages of high grafting rate and light color, is safe in process and is suitable for industrial production.

Description

Technical Field

[0001] This invention belongs to the field of fine chemical technology, specifically relating to a continuous preparation method of highly polar maleic anhydride modified Fischer-Tropsch wax (FT-g-MAH), and its application as a key component in composite waxes for emulsion explosives. Background Technology

[0002] The performance of emulsion explosives is highly dependent on the stability of the W / O emulsion formed by its oil phase material (composite wax) and aqueous oxidant solution. Traditional oil phase materials, such as mineral oil and paraffin, have weak molecular polarity and poor compatibility with the strongly polar inorganic salt water phase. They must rely on external emulsifiers such as Span-80 to reduce interfacial energy and stabilize the emulsion structure. However, external emulsifiers have the following inherent drawbacks: (1) high cost; (2) easy migration and precipitation during long-term storage, leading to emulsion demulsification and failure; (3) their thermal and chemical stability directly affects the lifespan and safety of the explosive.

[0003] Fischer-Tropsch wax is an ideal oil-phase material matrix with advantages such as high melting point, high hardness, and narrow molecular weight distribution. However, it is composed entirely of nonpolar straight-chain alkanes, and its inherent low polarity results in extremely poor emulsifying ability, which cannot meet the requirements of high-performance emulsion explosives for microstructure and long-term stability.

[0004] Chemical modification of Fischer-Tropsch wax to introduce polar functional groups is the fundamental way to improve its emulsifying properties. Maleic anhydride (MAH) grafting is a common modification method. However, existing research on MAH grafting of Fischer-Tropsch wax has significant shortcomings: First, it generally employs batch reactions, resulting in low grafting rates (usually below 2%), numerous side reactions, dark-colored products, and limited improvement in polarity; second, existing research mainly focuses on its use as a PVC lubricant or plastic compatibilizer, and no study has systematically revealed and verified that high-grafting-rate FT-g-MAH can serve as a highly efficient built-in emulsifier in emulsion explosive systems, fundamentally solving the technical problem of emulsion stability.

[0005] Furthermore, in the mining of phosphate deposits in certain karst landforms, blasting operations face two major technical challenges: first, in high-water-content borehole environments, explosives need to possess excellent water resistance, but traditional water-resistant modifications often lead to increased explosive detonation velocities, exceeding the low detonation velocity requirements for phosphate blasting; second, the Fe content in phosphate ore... 3+ Phosphate blasting easily induces calcium phosphate oxidation, necessitating the addition of antioxidants. However, traditional antioxidants are mostly physically mixed thiourea compounds, which are prone to migration and loss. Furthermore, excessive use can deplete the oxidizer in the explosive, leading to a decrease in detonation efficiency. Therefore, developing a modified Fischer-Tropsch wax that combines "water resistance and low detonation velocity synergy" with an environmentally friendly and easily industrialized process is crucial for addressing the pain points of karst phosphate blasting. Summary of the Invention

[0006] This invention provides a continuous preparation method for maleic anhydride-modified Fischer-Tropsch wax and its application in emulsion explosives. The technical problem to be solved is to overcome the problems of poor polarity and insufficient emulsification performance of Fischer-Tropsch wax in the prior art, as well as the high cost and poor stability of traditional emulsion explosives that rely on external emulsifiers.

[0007] This invention provides the following technical solution: In a first aspect, a continuous preparation method for highly polar maleic anhydride-modified Fischer-Tropsch wax includes the following steps: S1 continuously feeds molten Fischer-Tropsch wax, maleic anhydride, dicumyl peroxide and triallyl triisocyanurate into the CSTR reactor and stirs them to react. S2: The product from step S1 is continuously introduced into a static mixer, and 2-acryloyloxymethyl-4-methylthiazolidin-2-thione is pumped in to carry out the reaction; S3: The product from step S2 is introduced into a terminal mixer, heated, and modified nano-calcium carbonate is added. The mixture is stirred and dispersed, and the product is allowed to cool naturally to room temperature to obtain maleic anhydride-modified Fischer-Tropsch wax.

[0008] Preferably, in step S1, the mass ratio of Fischer-Tropsch wax: maleic anhydride: dicumyl peroxide: triallyl triisocyanurate is 100 : (0.06-0.12) : (0.08-0.12) : (0.01-0.05).

[0009] Preferably, in step S1, the mass ratio of Fischer-Tropsch wax: maleic anhydride: diisopropylbenzene peroxide: triallyl triisocyanurate is 100: 0.08: 0.10: 0.03; and the Fischer-Tropsch wax is 60# high melting point Fischer-Tropsch wax.

[0010] Preferably, in step S1, the stirring speed is 500-600 rpm, the temperature is 90-110℃, and the reaction space time is 10-20 min.

[0011] Preferably, in step S2, the mass ratio of Fischer-Tropsch wax to 2-acryloyloxymethyl-4-methylthiazolidin-2-thione is 100:(0.04-0.08), the stirring speed is 500-600 rpm, the temperature is 90-110℃, the reaction space time is 10-20 min, and the residence time is 4-5 min.

[0012] Preferably, in step S3, the temperature is raised to 90-100℃, modified nano-calcium carbonate is added, the mass ratio of Fischer-Tropsch wax to modified nano-calcium carbonate is 100:(0.04-0.06), and the mixture is dispersed for 3-5 minutes at a stirring speed of 500-600 rpm.

[0013] Preferably, in step S3, the modified nano-calcium carbonate is prepared by taking calcium carbonate with a particle size of 80-90 nanometers, drying it at 100°C for 2 hours, adding 2.5% (relative to the mass of calcium carbonate) of KH-570 silane coupling agent, stirring at 80°C for 15 minutes, and then cooling it for later use.

[0014] In a second aspect, the present invention provides a highly polar maleic anhydride modified Fischer-Tropsch wax (FT-g-MAH) prepared by the method described in the first aspect, characterized in that its grafting rate is not less than 6.5% and its whiteness value is not less than 42.0.

[0015] Thirdly, the present invention provides the application of high polarity maleic anhydride modified Fischer-Tropsch wax as described in the second aspect in the preparation of composite waxes for emulsion explosives.

[0016] Fourthly, the present invention provides a composite wax for emulsion explosives, comprising the highly polar maleic anhydride-modified Fischer-Tropsch wax (FT-g-MAH) as described in the second aspect; wherein the highly polar maleic anhydride-modified Fischer-Tropsch wax has a mass fraction of 40%-70% in the composite wax; Preparation method of composite wax: According to the mass fraction, 52% of high polar maleic anhydride modified Fischer-Tropsch wax, 37% of 100# Fischer-Tropsch wax, 6% of crude wax, 3% of microcrystalline wax, and 2% of ethylene-vinyl acetate copolymer are stirred and mixed at 70°C for 20 minutes to prepare composite wax with a dropping melting point of 62°C.

[0017] Fifthly, the present invention provides an emulsion explosive comprising an oil phase material, said oil phase material comprising the composite wax for emulsion explosives as described in claim 8 or 9.

[0018] Preparation of emulsion explosives: The oil phase (composite wax accounts for 85%) and the aqueous phase (ammonium nitrate 87%, sodium nitrate 6%, water 7%) are added to an emulsifier at a mass ratio of 1:(8-10), emulsified at 9000-10000 rpm for 4-6 minutes, sensitized with 1.5% porous starch, and then cooled to prepare emulsion explosives.

[0019] The emulsion explosive has a W / O type emulsion structure, and the highly polar maleic anhydride modified Fischer-Tropsch wax serves as an embedded emulsifier and oil phase carrier to improve the stability of the emulsion.

[0020] The beneficial effects of this invention are as follows: 1. This invention successfully introduces maleic anhydride groups with a high grafting rate (≥6.5%) into the Fischer-Tropsch wax molecular chain through a continuous process, transforming it from a completely nonpolar structure into an amphiphilic structure with a "lipophilic long chain + hydrophilic polar head". When applied to emulsion explosives, FT-g-MAH molecules can spontaneously accumulate at the oil-water interface, with their lipophilic ends anchored in the oil phase and the highly polar anhydride groups extending into the aqueous phase, acting as an "internal emulsifier". This significantly reduces interfacial tension and forms a robust interfacial film, which is unmatched by traditional physically mixed emulsifiers.

[0021] 2. The FT-g-MAH of this invention, when used in composite waxes, can produce emulsion explosives with finer emulsion particles, more uniform distribution, and excellent storage stability. Accelerated storage experiments show that its crystallization rate is significantly lower than that of formulations using traditional composite waxes, which can greatly extend the effective storage period of the explosive and improve its safety in use.

[0022] 3. This invention employs a continuous production process combining a CSTR reactor and a static mixer, overcoming the shortcomings of batch production and achieving efficient, stable, and controllable continuous production with good product consistency, suitable for large-scale industrial applications. Simultaneously, the continuous process involves low online material volume and precise temperature control, greatly improving the safety of production using peroxide initiators and laying a solid foundation for industrial scale-up. Furthermore, compared to traditional synthesis methods, this invention adds the auxiliary agent triallyl triisocyanurate (TAIC) to optimize the reaction process. Experiments showed that TAIC not only improves reactivity and grafting efficiency but also reduces reaction temperature and time. It may also partially participate in the reaction, forming cross-linked structures or grafted chains, significantly optimizing product performance.

[0023] 4. Through a two-step grafting process, maleic anhydride and 2-acryloyloxymethyl-4-methylthiazolidin-2-thione were introduced sequentially, grafting various polar functional groups onto the Fischer-Tropsch wax molecular chain. This significantly improved the grafting rate and enhanced the polarity of the final product, resulting in a more robust interfacial film in emulsion explosives. The introduced 2-acryloyloxymethyl-4-methylthiazolidin-2-thione not only participated in the grafting reaction, but its unique thiazolidinyl heterocyclic structure also formed stable chelates with Fe3+ on the phosphate rock surface, endowing the product with excellent anti-oxidation properties. Simultaneously, the modified wax prepared by this method effectively controlled the detonation velocity when used in emulsion explosives, stabilizing it at a low level to meet the requirements of special blasting. The added modified nano-calcium carbonate not only acted as a temperature controller to lower the detonation temperature, but its good dispersibility also improved the mechanical strength of the composite wax. The final emulsion explosive exhibited high emulsion stability, good water resistance, excellent detonation performance, and a special effect in preventing mineral powder oxidation.

[0024] 5. The composite wax provided by this invention can reduce or even completely replace the use of traditional external emulsifiers (such as Span-80), effectively reducing raw material costs while improving explosive performance, and has extremely high market competitiveness. Detailed Implementation

[0025] The present invention will be further described in detail below through specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0026] Example 1: Continuous preparation of highly polar FT-g-MAH (1) Raw material preparation and pretreatment: 60# high melting point Fischer-Tropsch wax (melting point 60℃) is heated to 70℃ and completely melted; maleic anhydride is heated to 55℃ and melted; dicumyl peroxide is heated to 50℃ and melted; triallyl triisocyanurate is kept at room temperature; polyethylene glycol monomethyl ether acrylate (number average molecular weight 1000) is kept in liquid state at room temperature; 2-acryloyloxymethyl-4-methylthiazolidin-2-thionone is placed in a 35℃ heat preservation tank for later use, and the feed pipeline is heated to 30℃ to avoid crystallization; or it is mixed with molten Fischer-Tropsch wax at a mass ratio of 8:2 at 85℃ for 10 minutes to make a high concentration masterbatch, and kept at 40℃; calcium carbonate with a particle size of 80 nanometers is dried at 100℃ for 2 hours, 2.5% (relative to the mass of calcium carbonate) of KH-570 silane coupling agent is added, and it is stirred at 80℃ for 15 minutes in a high-speed mixer, and then cooled for later use.

[0027] (2) The CSTR reactor was preheated to 95°C and purged with nitrogen three times. Molten Fischer-Tropsch wax, maleic anhydride (0.08 parts), polyethylene glycol monomethyl ether acrylate (8%), dicumyl peroxide (0.10 parts), and triallyl triisocyanate (0.012 parts) were continuously pumped in using a metering pump. The stirring speed was 500 rpm, and the reaction space time was 11 minutes to obtain the first stage product. The mass ratio of Fischer-Tropsch wax: maleic anhydride: dicumyl peroxide: triallyl triisocyanate was 100: 0.08: 0.10: 0.03. The Fischer-Tropsch wax was 60# high melting point Fischer-Tropsch wax. (3) The first-stage product was continuously introduced into a static mixer at 89°C, and 2-acryloyloxymethyl-4-methylthiazoline-2-thione was pumped in. The material flow rate was 1.0 m / s, the stirring speed was 500 rpm, and the residence time was 4.5 minutes to obtain the second-stage product. The mass ratio of Fischer-Tropsch wax to 2-acryloyloxymethyl-4-methylthiazoline-2-thione was 100:0.06. (4) The second-stage product was introduced into a mixer, heated to 90°C, and modified nano-calcium carbonate was added. The mixture was stirred at 550 rpm for 5 minutes. The product was allowed to cool naturally to room temperature to obtain maleic anhydride modified Fischer-Tropsch wax.

[0028] The product was tested, and its grafting rate remained stable at (6.7 ± 0.2)%, and its whiteness value remained stable at (42.2 ± 0.2). Compared with the raw material Fischer-Tropsch wax, the kinematic viscosity (100℃) of the modified product increased from 4.3 mm² / s to 7.1 mm² / s, and the penetration (25℃) decreased from 18 (0.1 mm) to 15 (0.1 mm), indicating that its molecular chains became heavier due to grafting, resulting in a more compact structure.

[0029] Example 2 1. Based on Example 1, the specific data for the continuous flow reaction in step (2) are optimized, and the rest is the same as in Example 1.

[0030] Under continuous flow conditions with nitrogen protection, using Fischer-Tropsch wax as a reference and dicumyl peroxide as the initiator, with dicumyl peroxide dosage at 0.10 phr and maleic anhydride dosage at 0.08 phr, and a stirrer speed of 500 rpm, the effect of adding the auxiliary agent triallyl triisocyanurate on the reaction was investigated (Reaction 1: addition of triallyl triisocyanurate, dosage at 0.012 phr, reaction temperature at 100℃, reaction space time at 15 min; Reaction 2: no addition of triallyl triisocyanurate, reaction temperature at 100℃, reaction space time at 15 min). The experimental results, as shown in Table 1, indicate that under continuous flow conditions, the addition of triallyl triisocyanurate significantly improved the reaction, increasing the grafting rate and reducing the reaction temperature and time.

[0031] Table 1. Grafting rate and whiteness value under continuous flow conditions with or without the addition of FT-g-MAH.

[0032] 2. Based on Example 1, the specific data for the continuous flow reaction temperature in step (2) are optimized, and the rest is the same as in Example 1.

[0033] Under continuous flow conditions with nitrogen protection, using Fischer-Tropsch wax as a reference and dicumyl peroxide as an initiator, the effects of reaction temperature on the grafting rate and color of FT-g-MAH in step (2) were investigated. The results are shown in Table 2, indicating that a reaction temperature of 90-110ºC is more suitable. The maleic anhydride dosage was 0.08 phr, the initiator dosage was 0.10 phr, the auxiliary agent triallyl triisocyanate dosage was 0.03 phr, the reaction time was 15 min, and the stirrer speed was 500 rpm.

[0034] Table 2 Grafting rate and whiteness value of FT-g-MAH at different temperatures under continuous flow conditions

[0035] 3. Based on Example 1, the specific data for the continuous flow reaction time in step (2) are optimized, and the rest is the same as in Example 1.

[0036] Under continuous flow conditions with nitrogen protection, using dicumyl peroxide as the initiator, and with maleic anhydride at 0.08 phr, initiator at 0.10 phr, and triallyl triisocyanate at 0.03 phr, at a reaction temperature of 100℃ and a stirrer speed of 500 rpm, the effect of reaction space time on the grafting rate and color of FT-g-MAH was investigated. When the reaction time was less than 10 min, the reaction was incomplete. When the reaction time exceeded 20 min, further extension of the reaction time led to side reactions such as oxidation of Fischer-Tropsch wax at high temperatures. Although nitrogen was purged throughout the process, the impact of partial oxidation on the grafting reaction due to the excessively long reaction time could not be ignored. Therefore, a reaction space time of 10-20 min is more suitable for this experiment.

[0037] Table 3. Grafting rate and whiteness value of FT-g-MAH under different space-time conditions in continuous flow.

[0038] 4. Based on Example 1, the specific data for the continuous flow reaction stirring speed in step (2) are optimized, and the rest is the same as in Example 1.

[0039] Under continuous flow conditions with nitrogen protection, using dicumyl peroxide as the initiator, and with maleic anhydride at 0.08 phr, initiator at 0.10 phr, and triallyl triisocyanurate at 0.03 phr, at a reaction temperature of 100℃ and a reaction space time of 15 min, the effect of stirring speed on the grafting rate and color of maleic anhydride-modified Fischer-Tropsch wax (FT-g-MAH) was investigated. When the stirring speed was below 400 rpm, the grafted monomers and initiator were difficult to disperse and rapidly decomposed upon heating, resulting in excessively high local concentrations, inactivation of some initiators, or the generation of numerous byproducts, leading to a low grafting rate. The grafting rate no longer increased after reaching 500 rpm. Therefore, a stirring speed of 400-600 rpm is more suitable for this experiment.

[0040] Table 4. Grafting rate and whiteness value of FT-g-MAH under different stirring speeds in continuous flow conditions.

[0041] Comparative Example 1: (without the adjuvant triallyl triisocyanurate) The difference from Example 1 is that triallyl triisocyanurate was not added; otherwise, the process was the same as in Example 1. The resulting product had a grafting rate of 3.5% and a whiteness value of 41.2.

[0042] Comparative Example 2: (without 2-acryloyloxymethyl-4-methylthiazolidin-2-thione) The difference from Example 1 is that 2-acryloyloxymethyl-4-methylthiazolidin-2-thione is not added. After step (2), the rest is the same as in Example 1.

[0043] Comparative Example 3 (without modified nano-calcium carbonate) The difference from Example 1 is that modified nano-calcium carbonate is not added. After step (3), the rest is the same as in Example 1. Comparative Example 4: Traditional intermittent method Using the same raw materials as in Example 1, a 500L batch reactor was used. The materials were fed in three steps, with the reactor stopped and the next raw material added after each stage of reaction. The specific operation was as follows: (2) The reactor was preheated to 95°C and purged with nitrogen three times. Molten Fischer-Tropsch wax, maleic anhydride, polyethylene glycol monomethyl ether acrylate, dicumyl peroxide, and triallyl triisocyanate (0.012 parts) were added. The stirring speed was 500 rpm, and the reaction was carried out for 11 minutes to obtain the first stage product. The mass ratio of Fischer-Tropsch wax: maleic anhydride: dicumyl peroxide: triallyl triisocyanate was 100: 0.08: 0.10: 0.03. The Fischer-Tropsch wax was 60# high melting point Fischer-Tropsch wax. (3) Add 2-acryloyloxymethyl-4-methylthiazoline-2-thione, stir at 500 rpm for 5 minutes to obtain the second stage product; wherein the mass ratio of Fischer-Tropsch wax to 2-acryloyloxymethyl-4-methylthiazoline-2-thione is 100:0.06; (4) Add modified nano calcium carbonate, disperse at 90°C and stirring speed of 550 rpm for 5 minutes.

[0044] Example 2: Preparation of composite wax for emulsion explosives containing FT-g-MAH Composite waxes modified with maleic anhydride using FT-g-MAH (40-70%) were prepared according to Examples 1 and Comparative Examples 1-4. The preparation method of the composite wax was as follows: 52% high-polarity maleic anhydride modified Fischer-Tropsch wax, 37% 100# Fischer-Tropsch wax, 6% crude wax, 3% microcrystalline wax, and 2% ethylene-vinyl acetate copolymer were mixed at 70°C for 20 minutes to obtain the composite wax. The dropping melting point of this composite wax was 62°C.

[0045] Comparative Example 5: Traditional Composite Wax A traditional composite wax is made by mixing 87% ammonium nitrate, 6% sodium nitrate, and 7% water in a common petroleum-based wax at 70°C for 20 minutes. The wax has a melting point of 73°C.

[0046] Example 3: Preparation and Performance Evaluation of Emulsion Explosives Preparation process: Preparation of emulsion explosives: The oil phase (the composite wax prepared in Example 2) and the aqueous phase (87% ammonium nitrate, 6% sodium nitrate, and 7% water) were added to an emulsifier at a mass ratio of 1:(8-10). Emulsification was carried out at 9000-10000 rpm for 4-6 minutes. 1.5% porous starch was added for sensitization, and the mixture was cooled to obtain the emulsion explosive. The composite waxes prepared in the examples and comparative examples were heated to 95°C and melted to form the oil phase components. Under high-speed shearing conditions of 1400 rpm, 92 parts of the aqueous phase were slowly added to 8 parts of the oil phase, and shearing was performed for 5 minutes to form a W / O type emulsion. After cooling and sensitization, the emulsion explosive was obtained.

[0047] The specific experimental formulation design is shown in the table below: Explosive 1: Conventional petroleum wax (Comparative Example 5) Explosive 2, Example 1 product, addition amount 40%. Explosives in a 3:1 ratio (excluding TAIC), addition amount 40%. Explosives in a 4:2 ratio, with an addition rate of 40%. Explosives in a 5:3 ratio, with an addition rate of 40%. The explosives were mixed in a 6:4 ratio, with an addition amount of 40%.

[0048] Emulsion explosives prepared using different composite waxes exhibit significant differences in their initial state.

[0049] Table 5 Comparison of Initial Properties of Emulsion Explosives

[0050] Comparing explosives 2 and 3, explosive 3, without TAIC, is significantly inferior in grafting rate (original data 3.5%) and all subsequent properties, demonstrating the indispensability of TAIC in improving grafting reaction efficiency and final product performance. Explosive 4 (without AMMT) lacks anti-oxidation function and exhibits decreased long-term stability. Explosive 5 (without nano-CaCO3) shows weakened detonation temperature control and a higher detonation velocity decrease rate than explosive 2. Explosive 6 (intermittent method) lags behind in all aspects of performance, highlighting the significant advantages of the continuous process of this invention in ensuring product consistency and high performance.

[0051] Preparation method and test samples of emulsion explosives (explosives 1 to 6). The samples were placed in a high and low temperature cycling chamber (-10℃ / 50℃) for accelerated storage experiments.

[0052] Table 6 Crystallization rate of emulsion explosives after 7 days of accelerated storage.

[0053] Detonation performance test (detonation velocity reduction rate) measures the rate of detonation velocity reduction of the sample after accelerated storage for different periods.

[0054] Table 7. Detonation velocity reduction rate (%) during accelerated storage of emulsion explosives

[0055] The storage stability and detonation performance retention of the present invention are significantly superior to those of any comparative examples (explosives 3, 4, and 5) lacking a single component. The performance of explosive 2 is also far superior to that of explosive 6 prepared using the traditional batch method, demonstrating the advancement and necessity of the continuous process of the present invention. All formulations containing FT-g-MAH exhibit superior performance compared to the traditional composite wax explosive 1, demonstrating the enormous potential of the products of the present invention to replace traditional materials.

[0056] This invention successfully prepared highly polar, high-grafting-rate FT-g-MAH through an innovative continuous grafting process, and creatively applied it as a core component in a composite wax for emulsion explosives. This composite wax utilizes the amphiphilic nature of FT-g-MAH, achieving a technological leap from "passive emulsification" to "active emulsification." Experimental data fully demonstrate that it can significantly improve the initial emulsification quality, long-term storage stability, and adaptability to harsh environments of emulsion explosives, possessing extremely high industrial application value. The technical solution of this invention is explained through the above embodiments, but this invention is not limited to the above embodiments, that is, it does not mean that this invention must rely on the above specific embodiments to be implemented. Any improvements made by those skilled in the art based on this invention, or equivalent substitutions of the materials selected in this invention, fall within the scope of patent protection.

Claims

1. A continuous preparation method for highly polar maleic anhydride-modified Fischer-Tropsch wax, characterized in that, Includes the following steps: S1 continuously feeds molten Fischer-Tropsch wax, maleic anhydride, dicumyl peroxide and triallyl triisocyanurate into the CSTR reactor and stirs them to react. S2: The product from step S1 is continuously introduced into a static mixer, and 2-acryloyloxymethyl-4-methylthiazolidin-2-thione is pumped in to carry out the reaction; S3: The product from step S2 is introduced into a terminal mixer, heated, and modified nano-calcium carbonate is added. The mixture is stirred and dispersed, and the product is allowed to cool naturally to room temperature to obtain maleic anhydride-modified Fischer-Tropsch wax.

2. The preparation method according to claim 1, characterized in that, In step S1, the mass ratio of Fischer-Tropsch wax: maleic anhydride: dicumyl peroxide: triallyl triisocyanurate is 100 : (0.06-0.12) : (0.08-0.12) : (0.01-0.05).

3. The preparation method according to claim 1, characterized in that, In step S1, the mass ratio of Fischer-Tropsch wax: maleic anhydride: diisopropylbenzene peroxide: triallyl triisocyanurate is 100: 0.08: 0.10: 0.03; the Fischer-Tropsch wax is 60# high melting point Fischer-Tropsch wax.

4. The preparation method according to claim 1, characterized in that, In step S1, the stirring speed is 500-600 rpm, the temperature is 90-110℃, and the reaction space time is 10-20 min.

5. The preparation method according to claim 1, characterized in that, In step S2, the mass ratio of Fischer-Tropsch wax to 2-acryloyloxymethyl-4-methylthiazolidin-2-thione is 100:(0.04-0.08), the stirring speed is 500-600 rpm, the temperature is 90-110℃, the reaction space time is 10-20 min, and the residence time is 4-5 min.

6. The preparation method according to claim 1, characterized in that, In step S3, the temperature is raised to 90-100℃, modified nano-calcium carbonate is added, and the mass ratio of Fischer-Tropsch wax to modified nano-calcium carbonate is 100:(0.04-0.06). The mixture is dispersed for 3-5 minutes at a stirring speed of 500-600 rpm.

7. The preparation method according to claim 1, characterized in that, In step S3, the modified nano-calcium carbonate is prepared by taking calcium carbonate with a particle size of 80-90 nanometers, drying it at 100°C for 2 hours, adding 2.5% KH-570 silane coupling agent, stirring at 80°C for 15 minutes, and then cooling it for later use.

8. A highly polar maleic anhydride-modified Fischer-Tropsch wax prepared by the method according to any one of claims 1-5, characterized in that, Its grafting rate is not less than 6.5%, and its whiteness value is not less than 42.

0.

9. A composite wax for emulsion explosives, characterized in that, The compound contains the highly polar maleic anhydride-modified Fischer-Tropsch wax as described in claim 8; wherein the highly polar maleic anhydride-modified Fischer-Tropsch wax comprises 40%-70% by mass in the compound wax. Preparation method of composite wax: According to the mass fraction, high polar maleic anhydride modified Fischer-Tropsch wax, 100# Fischer-Tropsch wax, crude wax, microcrystalline wax, and ethylene-vinyl acetate copolymer are stirred and mixed to prepare composite wax.

10. An emulsion explosive, characterized in that, It comprises an oil phase material, wherein the oil phase material comprises the emulsified explosive composite wax as described in claim 8 or 9; Preparation of emulsion explosives: The oil phase and the water phase are added to the emulsifier at a mass ratio of 1:(8-10), emulsified at 9000-10000 rpm for 4-6 minutes, sensitized with 1.5% porous starch, and then cooled to prepare emulsion explosives.

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