Low-temperature-resistant composite oil phase formula and preparation process thereof
By using a synergistic system of polyalphaolefin, microcrystalline wax, emulsifier and interface enhancer in emulsion explosives, the crystallization morphology of microcrystalline wax is controlled, solving the problem of solidification of emulsion explosives at low temperatures, achieving stability of fluidity and explosive performance in extremely cold environments, and ensuring the safety and reliability of explosives.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HONGDA CIVIL EXPLOSIVES GRP CO LTD
- Filing Date
- 2026-04-22
- Publication Date
- 2026-07-24
AI Technical Summary
Conventional emulsion explosives are prone to crystallization and precipitation of wax components in cold environments, which leads to increased viscosity and loss of fluidity in the oil phase system. This causes latex particles to aggregate, demulsify, and oxidant to crystallize, resulting in hardening of the explosive, loss of elasticity, decreased detonation sensitivity, and even mis-detonation, posing safety hazards and economic losses.
A synergistic system of polyalphaolefin, microcrystalline wax, emulsifier, microcrystalline wax modifier, and interface enhancer was adopted. The physical action of the microcrystalline wax modifier was used to regulate the crystallization morphology of microcrystalline wax and inhibit the solidification of the oil phase to prepare a low-temperature resistant composite oil phase. The system included polymethyl methacrylate as a microcrystalline wax modifier. By utilizing the structural similarity between its alkyl side chain and microcrystalline wax, fine and dispersed microcrystals were formed, maintaining the fluidity and structural stability of the oil phase.
Significantly improves the storage and use reliability of emulsion explosives in extremely cold environments, ensuring that the explosives still have good fluidity and explosive performance after being stored at -45℃ to -35℃ for 30 days, avoiding low-temperature hardening and demulsification, and ensuring the safety and economic benefits of blasting operations.
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Figure CN122444565A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of emulsion explosives technology, and more particularly to a low-temperature resistant composite oil phase formulation and its preparation process. Background Technology
[0002] Emulsion explosives, as a type of water-containing industrial explosive, are widely used in mining, engineering blasting and other fields due to their good safety, strong water resistance and excellent explosive performance. Essentially, they are a water-in-oil emulsion with an oil phase material as the continuous phase and an oxidant salt solution as the dispersed phase. The oil phase, as the continuous phase, plays a key role in encapsulating microdroplets of the oxidant solution, maintaining the stability of the emulsion structure, providing combustible components and ensuring mechanical properties.
[0003] However, in cold regions during winter, such as northern and western plateaus and high-altitude mining areas in my country, the ambient temperature can remain below [temperature] for extended periods. 25℃, or even higher At 40℃, under these extreme conditions, the oil phase of conventional emulsion explosives typically consists mainly of ordinary mineral oil and paraffin wax. The wax components are prone to crystallization and precipitation, forming a three-dimensional network structure. This leads to increased viscosity, loss of fluidity, and even overall solidification and hardening of the entire oil phase system. The deterioration of the physical state of the oil phase directly causes the destruction of the microstructure, such as latex particle aggregation, demulsification, and oxidant salting-out. Ultimately, the emulsion explosive hardens and loses its elasticity, resulting in a decrease in the explosive's initiation sensitivity, unstable detonation transmission performance, and even complete misfires, posing safety hazards and economic losses to blasting operations.
[0004] To address the low-temperature failure problem of emulsion explosives, those skilled in the art have made numerous attempts. For example, they have introduced polar groups to enhance oil film toughness by oxidizing raw materials such as petroleum wax and vacuum depressant paste. However, this method is complex, energy-intensive, and chemical modification can introduce unstable oxygen-containing groups, affecting long-term storage safety. Another approach is to simultaneously optimize multiple components in both the aqueous and oil phases to improve low-temperature performance; however, this method is complex, costly, and has limited effectiveness at extreme low temperatures.
[0005] Therefore, developing a specialized composite oil phase formulation that is cost-effective, technologically feasible, and can fundamentally improve the low-temperature performance of emulsion explosives has significant industrial application value. Summary of the Invention
[0006] To address the aforementioned problems in the prior art, this invention provides a low-temperature resistant composite oil phase formulation and its preparation process. The composite oil phase comprises, by weight, poly(α-hydroxyl)... Olefins 50 70 parts, microcrystalline wax 5 20 parts, emulsifier 2 5 parts, microcrystalline wax modifier 1 3 parts and interface enhancer 0.5 1 part, wherein the microcrystalline wax modifier is C12 C18 alkyl side chain polymethyl methacrylate. Its preparation process is as follows: [The text abruptly ends here, likely due to an incomplete sentence or missing information.] After the olefins and microcrystalline wax are dissolved, the mixture is cooled and then sequentially added with an emulsifier, an interface enhancer, and a microcrystalline wax modifier. The mixture is then activated by high-speed shear stirring and cooled. This process is used to construct polyα-... Olefins Microcrystalline wax emulsifier Interface enhancer The microcrystalline wax modifier synergistic system utilizes the molecular structural similarity between the microcrystalline wax modifier and microcrystalline wax. Through adsorption and steric hindrance effects, it can directionally regulate the crystallization morphology of microcrystalline wax during the cooling process of the oil phase, so as to form fine and dispersed microcrystals. This inhibits the low-temperature solidification of the oil phase and significantly improves the storage and use reliability of emulsion explosives in extremely cold environments.
[0007] The objective of this invention can be achieved through the following technical solutions: In a first aspect, a low-temperature resistant composite oil phase is provided, comprising the following raw materials in parts by weight: Low pour point synthetic base oil 50 70 copies; Microcrystalline wax 5 20 copies; Emulsifier 2 5 copies; Microcrystalline wax modifier 1 3 copies; Interface enhancer 0.5 1 copy; The low-pour-point synthetic base oil has a pour point range of -60℃ to -40℃, and the microcrystalline wax has a dropping melting point of 50℃. The pour point of the composite oil phase is 70℃, and the pour point range is -45℃ to -35℃.
[0008] The microcrystalline wax modifier in this invention refers to a polymer additive that can change the crystallization morphology and habit of microcrystalline wax in the oil phase through physical actions, such as adsorption and steric hindrance, thereby inhibiting the formation of a three-dimensional network structure. Its function is to regulate the physical crystallization behavior of microcrystalline wax.
[0009] Furthermore, the low-pour-point synthetic base oil is polyalphaolefin (PAO). Olefins.
[0010] Furthermore, the microcrystalline wax modifier is an acrylate polymer with long-chain alkyl side chains.
[0011] Furthermore, the acrylate polymer with long-chain alkyl side chains is a poly(methacrylate) higher alcohol ester, wherein the alkyl side chains of the poly(methacrylate) higher alcohol ester have a carbon number of C12. C18.
[0012] Furthermore, the emulsifier is sorbitol monooleate.
[0013] Furthermore, the interface enhancer is octadecyl alcohol or hexadecyl alcohol.
[0014] In a second aspect, an emulsion explosive is provided, wherein the oil phase component comprises the low-temperature resistant composite oil phase described in the first aspect.
[0015] Furthermore, after the emulsion explosive is stored at a low temperature of -45°C to -35°C for 30 days, its sympathetic detonation distance is 17.2 cm to 19.4 cm.
[0016] Thirdly, a process for preparing a low-temperature resistant composite oil phase is provided, comprising the following steps: S1. Heat the low-pour-point synthetic base oil to 60°C. Add the microcrystalline wax at 75°C with stirring, and then heat to 70°C. Stir continuously at 80℃ until the microcrystalline wax is completely dissolved to obtain a uniform oil-phase base material; S2. Cool the oil phase base obtained in step S1 to 40°C. At 55°C, first add the emulsifier and the interface enhancer, stir and mix evenly, then add the microcrystalline wax modifier, and continue stirring for 1 minute. Three hours are required to allow all components to fully disperse and activate. Under high-speed shearing, polymethyl methacrylate (PMMA) molecules, due to the high structural similarity between their alkyl side chains (-COOR) and microcrystalline wax molecules (long-chain alkanes), pre-adsorb and complex dispersed wax molecules through van der Waals forces.
[0017] S3. Stop heating and cool the mixture obtained in step S2 to 20°C. The low-temperature resistant composite oil phase was obtained at 28℃.
[0018] Upon cooling, polymethyl methacrylate (PMMA) molecules competitively and preferentially adsorb onto specific active crystal faces of newly formed microcrystalline wax nuclei. Their massive polymer backbone creates insurmountable steric hindrance on the crystal faces, physically interfering with the orderly stacking of subsequent wax molecules into the lattice. This forces the microcrystalline wax to abandon normal layer-by-layer growth and instead form numerous small, approximately spherical or short rod-shaped, isotropic dispersed crystals. Because these crystals are partially coated with PMMA, their surface energy is reduced, making it difficult for them to connect and form a network.
[0019] Furthermore, in step S2, the stirring is high-speed shear stirring, with a shear rate range of 6000. 8000 rpm.
[0020] The beneficial effects of this invention are as follows: (1) This invention creatively constructs a low-pour-point synthetic base oil. Microcrystalline wax emulsifier Interface enhancer The microcrystalline wax modifier synergistic system has clearly defined functions for each component, and the components are interdependent. Among them, polyα... Olefins (PAO), as low-pour-point synthetic base oils, have a pour point of -60℃ to -40℃ and a highly branched and regular molecular structure, providing a mobile phase that is not easily frozen at ultra-low temperatures. They also provide a pure and inert working environment for other functional components. Microcrystalline wax, as the structural framework, provides the necessary gel strength and film-forming properties. The selection of its dropping melting point ensures structural strength at room temperature and plasticity at low temperatures. The microcrystalline wax modifier is poly(methacrylate) higher alcohol ester, whose long-chain alkyl side chains are highly similar in chemical structure to the long-chain alkanes of the microcrystalline wax. Span The synergistic effect of 80 and octadecyl alcohol not only forms a stable oil-water interface film during emulsification, but its pre-addition also creates a microenvironment within the oil phase that is conducive to subsequent modification.
[0021] (2) In step S2 of the preparation process, the polymethyl methacrylate high carbon alcohol ester molecule exhibits stronger interfacial activity due to the high similarity between its side chain long alkyl and the long chain alkanes of microcrystalline wax in terms of molecular configuration and hydrophobicity. It competitively and preferentially adsorbs onto the specific growth crystal surface of the forming microcrystalline wax crystal nucleus. After adsorption, the polymethyl methacrylate high carbon alcohol ester polymer backbone forms a dynamic steric hindrance layer at the crystal nucleus / solution interface, which strongly interferes with the orderly stacking of subsequent wax molecules into the lattice. It directionally controls the crystallization morphology of microcrystalline wax from easily forming large sheet-like, interconnected crystals to a large number of nano- to submicron-scale, approximately spherical, dispersed and isotropic fine crystals, preventing the formation of a three-dimensional network structure and eliminating the low-temperature solidification failure caused by network crystallization.
[0022] (3) The inert environment of PAO is the cornerstone for the function of polymethyl methacrylate. Microcrystalline wax with a specific melting point is an object that can be effectively modified. Emulsifier and interface enhancer jointly create an optimized dispersion system. Polymethyl methacrylate is the key to triggering the synergistic effect. This synergistic effect enables the final composite oil phase to maintain good room temperature performance at low temperatures of -45℃ to -35℃, achieving a unity of fluidity, structural stability and emulsification ability. Detailed Implementation
[0023] To further illustrate the technical means and effects of the present invention in achieving the intended purpose, the following preferred embodiments provide a detailed description of the specific implementation methods, structures, features, and effects of the present invention.
[0024] Example 1 (1) The composite oil phase formulation (parts by weight) is as follows: Polyalpha Olefin PAO (Pour point) 60 parts of 52℃; 12 parts of microcrystalline wax (dropping melting point 60℃); 12 parts of sorbitan monooleate (Span 80) 3 parts; polymethyl methacrylate (C16 side chain) 2 parts; octadecyl alcohol 0.8 parts; 2,6-di-tert-butyl-p-cresol (BHT, antioxidant) 0.2 parts.
[0025] (2) Preparation process S1. Polymerize α Olefins are added to the reactor and heated to 68°C. Microcrystalline wax is added while stirring, and the temperature is raised to 75°C. Stirring is continued until the microcrystalline wax is completely dissolved to obtain a uniform oil-phase base. S2. Cool the oil phase base obtained in step S1 to 48°C, and first add Span. After mixing 80 and octadecyl alcohol for 10 minutes, add polymethyl methacrylate and BHT, and stir at 7000 rpm for 2 hours to fully disperse and activate the components. S3. Stop heating and cool the mixture obtained in step S2 to 24°C to obtain the low-temperature resistant composite oil phase.
[0026] Example 2 (1) The composite oil phase formulation (parts by weight) is as follows: Polyalpha Olefins (freezing point) 50 parts of 52℃; 5 parts of microcrystalline wax (dropping melting point 60℃); 5 parts of sorbitan monooleate (Span 80) 2 parts; polymethyl methacrylate (C16 side chain) 1 part; octadecyl alcohol 0.5 parts; 2,6-di-tert-butyl-p-cresol (BHT, antioxidant) 0.2 parts.
[0027] (2) Preparation process S1. Polymerize α Olefins are added to the reactor and heated to 60°C. Microcrystalline wax is added while stirring, and the temperature is raised to 70°C. Stirring is continued until the microcrystalline wax is completely dissolved to obtain a uniform oil-phase base. S2. Cool the oil phase base obtained in step S1 to 40°C, and first add Span. After mixing 80 and octadecyl alcohol for 10 minutes, add polymethyl methacrylate and BHT, and stir at 6000 rpm for 3 hours to fully disperse and activate the components. S3. Stop heating and cool the mixture obtained in step S2 to 20°C to obtain the low-temperature resistant composite oil phase.
[0028] Example 3 (1) The composite oil phase formulation (parts by weight) is as follows: Polyalpha Olefin PAO (Pour point) 70 parts of 52℃; 20 parts of microcrystalline wax (dropping melting point 60℃); 20 parts of sorbitan monooleate (Span 80) 5 parts; polymethyl methacrylate (C16 side chain) 3 parts; octadecyl alcohol 1 part; 2,6-di-tert-butyl-p-cresol (BHT, antioxidant) 0.2 parts.
[0029] (2) Preparation process S1. Polymerize α Olefins are added to the reactor and heated to 75°C. Microcrystalline wax is added while stirring, and the temperature is raised to 80°C. Stirring is continued until the microcrystalline wax is completely dissolved to obtain a uniform oil-phase base. S2. Cool the oil phase base obtained in step S1 to 55°C, and first add Span. After mixing 80 and octadecyl alcohol for 10 minutes, add polymethyl methacrylate and BHT, and stir at 8000 rpm for 1 hour to fully disperse and activate the components. S3. Stop heating and cool the mixture obtained in step S2 to 28°C to obtain the low-temperature resistant composite oil phase.
[0030] Comparative Example 1 Based on Example 1, polyα Olefins replaced with an equal amount of mineral oil (pour point) (15℃), other conditions are the same as in Example 1.
[0031] Comparative Example 2 Based on Example 1, without the addition of polymethyl methacrylate, all other conditions are the same as in Example 1.
[0032] Comparative Example 3 Based on Example 1, the polymethyl methacrylate was replaced with an equal amount of T801 alkyl naphthalene depressant, and other conditions were the same as in Example 1.
[0033] Effect verification (1) Composite oil phase performance test The composite oil phases prepared in the above examples and comparative examples were tested for properties such as pour point, kinematic viscosity, appearance, and stability. For the specific pour point of the oil phase, refer to GB / T 510 "Determination of Pour Point of Petroleum Products"; For kinematic viscosity, please refer to GB / T 265-1988 "Determination of Kinematic Viscosity and Calculation of Dynamic Viscosity of Petroleum Products"; The appearance and stability are assessed using the general experimental methods in GB / T 3554-2008 "Determination of Oil Content in Petroleum Waxes," which assess the stability of wax products by observing crystal morphology and evaluate the low-temperature storage stability of products in the chemical industry. The specific methods are as follows: Low-temperature transparency / turbidity test: Place the oil phase in a transparent glass test tube and put it in a low-temperature constant temperature bath for 24 hours. Observe it under light against a black background. If it is clear or slightly uniformly opalescent, it indicates that the wax crystals have been sufficiently refined and dispersed; if it is obviously turbid, opaque, or milky white, it indicates that the wax crystals have aggregated and grown to the micrometer scale, forming a large number of particles that scatter light; if the oil phase is turbid, it means that the wax crystals have precipitated significantly and begun to aggregate. After emulsification, it will become a stress concentration point that destroys the integrity of the oil film, directly leading to low-temperature demulsification and hardening of the explosive.
[0034] Low-temperature fluidity / decantation test: Remove the test tube from the low-temperature bath, quickly invert it, and observe the flow of the oil phase. If it flows smoothly down within seconds or forms a uniform, continuous liquid film on the tube wall, it indicates good fluidity at low temperatures and the absence of a strong gel network inside. If it is difficult to flow, adheres to the tube wall in a paste-like manner, or exhibits a "gel-like" non-flowing state, it indicates the formation of a three-dimensional wax crystal network inside, locking in the oil molecules. Loss of fluidity means the oil phase has lost its function as a continuous phase; when emulsified with it, it cannot form a flexible oil film to encapsulate the aqueous phase, and the resulting explosive will easily harden at low temperatures.
[0035] Restoration and Precipitation Tests: Samples that have undergone low-temperature testing are returned to room temperature (25°C) for equilibration for 4 hours, and their reversibility is observed. If the sample returns to its initial transparent, uniformly flowing state with no precipitation at the bottom of the tube, it indicates that the low-temperature crystallization process is a reversible physical change and the structure has not been permanently destroyed. If the sample remains turbid, or insoluble flocculent or granular precipitates appear at the bottom of the tube, it indicates irreversible phase separation or severe wax crystal aggregation. Explosives made from this phase-separated oil phase are unstable during storage.
[0036] Table 1. Test results of composite oil phase properties
[0037] (2) Performance testing of emulsion explosive products The above-described examples and comparative examples were used to emulsify the composite oil phase with a fixed aqueous phase (68% ammonium nitrate, 12% sodium nitrate, and 12% water) under the same conditions to prepare explosives, according to GB18095. The standard 2000 "Emulsion Explosives" was used to test the sympathetic detonation distance, detonation velocity, and physical condition of emulsion explosives. The sympathetic detonation distance also referenced WJ / T 9055. The detonation velocity of emulsion explosives was determined in 2006, and GB / T 13228 was also referenced. 2015 Testing: Emulsion explosive samples were stored in a constant temperature chamber at the oil phase freezing point for 30 days. The evaluation of the explosive's physical state after storage was based on the general principles for describing the physical state of samples in GB / T 12436-1990 "Tests on the Functional Capacity of Explosives" and industry practices, establishing the following three-level evaluation criteria:
[0038] Table 2 Performance Test Results of Emulsion Explosives
[0039] Based on the above test results, the composite oil phases obtained in Examples 1-3 not only exhibit low-temperature resistance but also maintain the intact physical state of the emulsified explosive after storage, achieving an excellent (Grade A) rating and meeting overall performance standards. This effect is synergistically achieved through low-pour-point synthetic base oil, microcrystalline wax, emulsifier, microcrystalline wax modifier, and interface enhancer. Comparative Example 1 uses polyα... Olefins are replaced with mineral oil, and the oil phase pour point is only The oil phase had a low pour point of 18℃ and poor fluidity, resulting in poor explosive performance. In Comparative Example 2, after removing the microcrystalline wax modifier polymethyl methacrylate, the oil phase pour point increased to [missing value]. At 27℃, it solidifies and becomes difficult to flow; the explosive performance is also poor. In Comparative Example 3, after replacing the polymethyl methacrylate with a general pour point depressant, the pour point... At 31°C, the properties of the composite oil phase and the explosive properties of the explosive were also poor, far inferior to those in the example.
[0040] This invention utilizes the synergistic effect of its components to synthesize polyalpha polymers with a specific structure. Components such as olefins, microcrystalline waxes with specific melting points, and polymethyl methacrylates with specific functions are combined according to a specific process to obtain a low-temperature resistant composite oil phase.
[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.
Claims
1. A low-temperature resistant composite oil phase, characterized in that, The ingredients comprise the following parts by weight: Low pour point synthetic base oil 50 70 copies; Microcrystalline wax 5 20 copies; Emulsifier 2 5 copies; Microcrystalline wax modifier 1 3 copies; Interface enhancer 0.5 1 copy; The low-pour-point synthetic base oil has a pour point range of -60℃ to -40℃, and the microcrystalline wax has a dropping melting point of 50℃. The composite oil phase has a pour point of -45°C to -35°C.
2. The low-temperature resistant composite oil phase according to claim 1, characterized in that, The low-pour-point synthetic base oil is polyalpha... Olefins.
3. The low-temperature resistant composite oil phase according to claim 1, characterized in that, The microcrystalline wax modifier is an acrylate polymer with long-chain alkyl side chains.
4. The low-temperature resistant composite oil phase according to claim 3, characterized in that, The acrylate polymer with long-chain alkyl side chains is a poly(methacrylate) high-carbon alcohol ester, wherein the alkyl side chains of the poly(methacrylate) high-carbon alcohol ester have a carbon number of C12. C18.
5. The low-temperature resistant composite oil phase according to claim 1, characterized in that, The emulsifier is sorbitol monooleate.
6. The low-temperature resistant composite oil phase according to claim 1, characterized in that, The interface enhancer is octadecyl alcohol or hexadecyl alcohol.
7. An emulsion explosive, characterized in that, Its oil phase component comprises as claimed in claim 1 The low-temperature resistant composite oil phase described in any one of the six items.
8. The emulsion explosive according to claim 7, characterized in that, After the emulsion explosive is stored at a low temperature of -45°C to -35°C for 30 days, its sympathetic detonation distance is 17.2 cm to 19.4 cm.
9. A method as claimed in claim 1 The preparation process of the low-temperature resistant composite oil phase according to any one of the six claims is characterized in that, Includes the following steps: S1. Heat the low-pour-point synthetic base oil to 60°C. Add the microcrystalline wax at 75°C with stirring, and then heat to 70°C. Stir continuously at 80℃ until the microcrystalline wax is completely dissolved to obtain a uniform oil-phase base material; S2. Cool the oil phase base obtained in step S1 to 40°C. At 55°C, first add the emulsifier and the interface enhancer, stir and mix evenly, then add the microcrystalline wax modifier, and continue stirring for 1 minute. Three hours are required to allow all components to fully disperse and activate. S3. Stop heating and cool the mixture obtained in step S2 to 20°C. The low-temperature resistant composite oil phase was obtained at 28℃.
10. The preparation process according to claim 9, characterized in that, In step S2, the stirring is high-speed shear stirring, with a shear rate range of 6000. 8000 rpm.