Phosphate-based fire-resistant oil composition as well as preparation method and application thereof

Abstract

The invention discloses a phosphate-based fire-resistant oil composition as well as a preparation method and application thereof, and belongs to the technical field of fire-resistant oil compositions. The composition is prepared from the following components in parts by mass: 70 to 85 parts of triaryl phosphate ester, 10 to 20 parts of polyhydric alcohol phosphate ester, 0.5 to 2.0 parts of an organic amine type main antioxidant, 0.3 to 1.5 parts of a hindered phenol type auxiliary antioxidant, 0.1 to 0.8 part of a benzotriazole derivative, 0.05 to 0.3 part of a polysiloxane surfactant and 0.01 to 0.1 part of nano titanium dioxide. The composite material has excellent comprehensive performance, especially has outstanding advantages in the aspects of high-temperature stability, anti-oxidation service life and material protection, and can effectively reduce the equipment maintenance cost and prolong the equipment overhaul period.

Description

Technical Field

[0001] This invention belongs to the field of fire-resistant oil composition technology, and relates to a phosphate ester-based fire-resistant oil composition, its preparation method and application. Background Technology

[0002] In the power industry, especially in large thermal power generating units, the turbine regulation and control system is the core component ensuring the safe and stable operation of the unit. Because these systems typically operate in hazardous environments with high temperatures, high pressures, and potential ignition sources, their working medium must possess excellent fire safety. Therefore, fire-resistant oils based on phosphate ester synthetic esters are widely used. These synthetic esters have inherent flame-retardant properties, significantly reducing the risk of fire and becoming an irreplaceable functional liquid in modern high-parameter turbine EH (electro-hydraulic regulation) systems. In practical applications, this type of fire-resistant oil must simultaneously meet several stringent performance requirements: First, it must possess extremely high flash point and self-extinguishing properties, typically requiring a flash point above 240℃ and an extremely short self-extinguishing time, to ensure it will not become an ignition source in the event of high temperatures or accidental leakage, fundamentally guaranteeing the fire safety of the power plant. Secondly, since certain components of the turbine regulating system (such as actuators near the main steam valve) are exposed to high temperatures for extended periods, the hydraulic oil must possess excellent thermal stability and oxidation stability to resist thermal degradation and oxidative deterioration under prolonged high-temperature operation. This prevents abnormal viscosity increases or sludge deposition due to oil aging, which could clog precision servo valves. Thirdly, given the unavoidable presence of moisture in the power plant operating environment, the hydraulic oil must exhibit excellent hydrolytic stability and demulsibility. It must be able to quickly separate and remove intruding moisture, preventing ester hydrolysis caused by moisture retention, which could produce corrosive acidic substances, leading to internal system corrosion, metal surface deterioration, and a decline in the oil's electrical insulation properties. Furthermore, good material compatibility is crucial. In particular, it must not cause excessive swelling or shrinkage of various rubber seals (such as fluororubber and nitrile rubber) in the system. Strict control must also be maintained over corrosion of non-ferrous metal components such as copper and silver to ensure the long-term sealing reliability and component integrity of the entire hydraulic system. However, existing phosphate ester fire-resistant oil products still have several significant drawbacks under actual operating conditions. First, under prolonged high-temperature operation, some phosphate ester molecular chains break down, decomposing to produce small-molecule acidic phosphate esters and phosphoric acid. This leads to a sharp increase in the oil's acid value, accelerating electrochemical corrosion of metal components (such as bearings and bushings) and further catalyzing the oil's own hydrolysis, creating a vicious cycle. Second, traditional fire-resistant oils often rely on a single type of antioxidant (such as using only amines or phenols), which has limitations in its antioxidant mechanism and effective action phase. Under complex and alternating oxidative stress, the oil is consumed too quickly, resulting in a short overall oxidation induction period and a service life that cannot meet the requirements for extended overhaul cycles in supercritical and ultra-supercritical units. Furthermore, some triaryl phosphate ester fire-resistant oils exhibit significantly increased viscosity at low temperatures, even showing a tendency to freeze, leading to poor oil flowability, pumping difficulties, and response delays during cold starts, directly affecting the control accuracy and start-up reliability of the regulating system.

[0003] Therefore, developing a novel high-performance phosphate ester-based fire-resistant oil composition to improve its thermal stability, oxidation stability, hydrolytic stability, and wide temperature range performance, thereby fundamentally extending the service life of the oil and ensuring the safe operation of equipment, is of great significance for promoting technological progress in the power industry. Summary of the Invention

[0004] The purpose of this invention is to provide a phosphate ester-based fire-resistant oil composition, its preparation method, and its application, in order to solve the technical problems of poor thermal stability, oxidation stability, hydrolytic stability, and wide-temperature range performance of fire-resistant oil compositions in the prior art, which affect their service life.

[0005] To achieve the above objectives, the present invention employs the following technical solution: In a first aspect, the present invention provides a phosphate ester-based fire-resistant oil composition, comprising, by weight parts, 70-85 parts of triaryl phosphate, 10-20 parts of polyol phosphate, 0.5-2.0 parts of organic amine primary antioxidant, 0.3-1.5 parts of hindered phenolic secondary antioxidant, 0.1-0.8 parts of benzotriazole derivative, 0.05-0.3 parts of polysiloxane surfactant, and 0.01-0.1 parts of nano titanium dioxide.

[0006] Furthermore, the triaryl phosphate ester is tolyl diphenyl phosphate ester.

[0007] Furthermore, the polyol phosphate ester is pentaerythritol phosphate ester or trimethylolpropane phosphate ester.

[0008] Furthermore, the primary organic amine antioxidant is dinonyldiphenylamine; the hindered phenolic auxiliary antioxidant is β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester; and the benzotriazole derivative is toluenetriazole.

[0009] Furthermore, the benzotriazole derivative is toluenetriazole; and the polysiloxane surfactant is polyether-modified silicone oil.

[0010] Secondly, the present invention provides a method for preparing the phosphate ester-based fire-resistant oil composition, comprising the following steps: Triaryl phosphate and polyol phosphate were heated to a preset temperature under inert gas protection and stirred to obtain mixture a; Add an organic amine primary antioxidant diluted with ethanol and a hindered phenolic secondary antioxidant to the mixture, and react at a constant temperature to obtain mixture b; A benzotriazole derivative, a polysiloxane surfactant, and nano-titanium dioxide were added sequentially to mixture b, and the mixture was stirred continuously to obtain a mixed product. The mixture was filtered and vacuum devolatilized to obtain a phosphate-based fire-resistant oil composition.

[0011] Furthermore, the preset temperature is 80℃-90℃; the inert gas is nitrogen.

[0012] Furthermore, the total concentration of the organic amine primary antioxidant and the hindered phenolic secondary antioxidant in ethanol is 3wt%~8wt%; the isothermal reaction temperature is 80℃-90℃, and the time is 1 hour~2 hours.

[0013] Furthermore, the filtration process uses a 0.5μm~10μm filter element; the vacuum devolatilization is carried out under conditions where the residual pressure is below 0.1kPa.

[0014] Thirdly, the present invention provides the application of the phosphate ester-based fire-resistant oil composition as a lubricant in electrical equipment.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a phosphate ester-based fire-resistant oil composition, its preparation method, and its application. The composition is based on high-purity triaryl phosphate esters, supplemented with polyol phosphate esters, forming an inherently flame-retardant system. This ensures the oil is extremely difficult to ignite in high-temperature or leak environments and can self-extinguish instantly, providing a very high level of fire safety for electrical equipment. Furthermore, the synergistic compound system of organic amines and hindered phenolic antioxidants employs a dual-effect antioxidant synergistic mechanism. The main antioxidant is responsible for chain termination, while the auxiliary antioxidant regenerates the active center of the main antioxidant, extending the oxidation induction period. The introduction of nano-titanium dioxide as a free radical scavenger significantly increases the thermal decomposition temperature. In addition, the polysiloxane surfactant solves the cavitation problem caused by slow air release in traditional phosphate ester systems. The addition of polyol phosphate esters improves extreme pressure carrying capacity while maintaining flame retardancy. This invention exhibits excellent overall performance, particularly in high-temperature stability, antioxidant lifespan, and material protection, effectively reducing equipment maintenance costs and extending equipment overhaul cycles. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 The image shows the results of a closed-cup aging test at 115°C in Example 1 of this invention. Detailed Implementation

[0018] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0019] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0020] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0021] In this article, unless otherwise specified, the terms “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of”. For example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a”.

[0022] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0023] The present invention will now be described in further detail with reference to the accompanying drawings: This invention discloses a phosphate ester-based fire-resistant oil composition, comprising, by weight, 70-85 parts of triaryl phosphate, 10-20 parts of polyol phosphate, 0.5-2.0 parts of organic amine primary antioxidant, 0.3-1.5 parts of hindered phenolic secondary antioxidant, 0.1-0.8 parts of benzotriazole derivative, 0.05-0.3 parts of polysiloxane surfactant, and 0.01-0.1 parts of nano-titanium dioxide. This invention provides a phosphate ester-based fire-resistant oil composition for power applications that combines high safety, long lifespan, and wide temperature range adaptability, achieving performance breakthroughs through the compounding of specific components. The functions of each component are shown in Table 1 below.

[0024] Table 1

[0025] In one feasible embodiment of the present invention, the triaryl phosphate ester is tolyl diphenyl phosphate ester, specifically a mixture of ortho / para isomers of tolyl diphenyl phosphate ester (TDP). The polyol phosphate ester is pentaerythritol phosphate ester or trimethylolpropane phosphate ester. The organic amine primary antioxidant is dinonyldiphenylamine; the hindered phenolic secondary antioxidant is octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; the benzotriazole derivative is tolyltriazole. The benzotriazole derivative is tolyltriazole; and the polysiloxane surfactant is polyether-modified silicone oil.

[0026] This invention discloses a method for preparing the above-mentioned phosphate ester-based fire-resistant oil composition, comprising the following steps: S1, heating the triaryl phosphate ester and the polyol phosphate ester to a preset temperature under inert gas protection and stirring to obtain mixture a; In this step, the preset temperature is 80℃-90℃; the inert gas is nitrogen.

[0027] S2, add an organic amine primary antioxidant diluted with ethanol and a hindered phenolic secondary antioxidant to the mixture, and react at a constant temperature to obtain mixture b; In this step, the total concentration of the organic amine primary antioxidant and the hindered phenolic secondary antioxidant in ethanol is 3wt%~8wt%; the isothermal reaction temperature is 80℃-90℃, and the time is 1 hour~2 hours.

[0028] S3, add benzotriazole derivative, polysiloxane surfactant and nano titanium dioxide to mixture b in sequence, and stir continuously to obtain a mixed product; S4. The mixture is filtered and vacuum devolatilized to obtain a phosphate ester-based fire-resistant oil composition.

[0029] In this step, the filtration process uses a 0.5μm~10μm filter element; the vacuum devolatilization is carried out under conditions where the residual pressure is below 0.1kPa.

[0030] This invention employs a dual-effect antioxidant synergistic mechanism: the primary antioxidant is responsible for chain termination, while the auxiliary antioxidant regenerates the active center of the primary antioxidant, thus extending the oxidation induction period; the introduction of nano-titanium dioxide as a free radical scavenger significantly increases the thermal decomposition temperature; the application of polysiloxane surfactants solves the cavitation problem caused by slow air release in traditional phosphate ester systems; and the addition of polyol phosphate esters improves extreme pressure carrying capacity while maintaining flame retardancy. Figure 1As shown, the phosphate ester-based fire-resistant oil composition of this invention exhibits excellent long-term thermal stability and oxidation stability. It provides comprehensive protection for precision servo valves, hydraulic actuators, bearings, and seals in the regulating system, effectively preventing control failures, internal leaks, and performance degradation caused by corrosion, wear, and seal failure, thus ensuring the accuracy and reliability of the unit's regulation and control. It provides crucial material support for the safe, long-term, efficient, and stable operation of the generator set, possessing extremely high engineering application value and promising prospects for widespread adoption.

[0031] The composition of this invention has demonstrated the following advantages as verified by ASTM standard testing: Flame retardancy: Flash point > 240℃, self-extinguishing time < 1 second; Thermal stability: kinematic viscosity change rate after aging at 260℃ for 1000h < ±15%; Oxidative stability: RBOT test reaches over 1000 min; Material compatibility: Passes ISO 6614 rubber compatibility test, with a volume expansion rate of <5%; Copper corrosion: Weight loss of copper sheet after 56 days <0.02g / m³ 2 ; Air release value: <3% (Denison HF-0 test).

[0032] This invention discloses the application of the aforementioned phosphate ester-based fire-resistant oil composition as a lubricant in power equipment. The product has been successfully applied to the EH oil system of a 600MW supercritical generator unit. After 8000 hours of continuous operation, testing showed that the acid value increase was <0.1mgKOH / g, and the particulate contamination level remained below NAS 6, proving that it fully meets the stringent requirements of the power industry for fire-resistant oils. It effectively solves the problems of insufficient thermal stability and short service life existing in the prior art, and has significant economic and social benefits.

[0033] Example 1 This invention discloses a phosphate ester-based fire-resistant oil composition, the specific formulation of which, by mass parts, comprises: TDP (Industrial Grade) 80 servings 15 parts of pentaerythritol phosphate 1.2 parts dinonyldiphenylamine 0.8 parts of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester 0.5 parts of toluenetriazole 0.2 parts of polyether-modified silicone oil 0.05 parts of rutile nano-TiO2 The specific preparation process includes the following steps: S1, TDP and pentaerythritol phosphate are added to the reactor, heated to 85°C and stirred until homogeneous to obtain mixture a.

[0034] S2, prepare an ethanol solution (concentration 5%) containing the antioxidant dinonyldiphenylamine and octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, add it dropwise, and keep the reaction at the temperature for 1.5 hours to obtain mixture b.

[0035] S3, after cooling to 60℃, toluenetriazole, polyether-modified silicone oil and nano titanium dioxide are added in sequence, and the mixture is stirred for 45 minutes to obtain a mixed product; S4. After two-stage filtration of the mixed product (first using a 10μm filter and then a 0.5μm filter), it is de-volatile for 2 hours under residual pressure <0.1kPa to obtain a light yellow transparent liquid, which is the phosphate ester-based fire-resistant oil composition.

[0036] Example 2 This invention discloses a phosphate ester-based fire-resistant oil composition suitable for small generator sets with low extreme pressure performance requirements. The specific formulation, by mass parts, includes: TDP (Industrial Grade) 85 copies 10 parts of trimethylolpropane phosphate 0.8 parts of dinonyldiphenylamine 0.5 parts of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester 0.5 parts of toluenetriazole 0.2 parts of polyether-modified silicone oil 0.05 parts of rutile nano-TiO2 The specific preparation process includes the following steps: S1, TDP and trimethylolpropane phosphate are added to a reaction vessel, heated to 85°C under nitrogen protection and stirred until homogeneous to obtain mixture a.

[0037] S2, prepare an ethanol solution (concentration 5%) containing the antioxidant dinonyldiphenylamine and octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, add it dropwise slowly, and keep the reaction at the temperature for 1 hour to obtain mixture b.

[0038] S3, after cooling to 60℃, toluenetriazole, polyether-modified silicone oil and nano titanium dioxide are added in sequence, and the mixture is stirred continuously for 30 minutes to obtain a mixed product; S4. After two-stage filtration of the mixed product (first using a 10μm filter and then a 0.5μm filter), it is de-volatile for 2 hours under residual pressure <0.1kPa to obtain a light yellow transparent liquid, which is the phosphate ester-based fire-resistant oil composition.

[0039] Example 3 This invention discloses a phosphate ester-based fire-resistant oil composition, the specific formulation of which, by mass parts, comprises: TDP (Industrial Grade) 70 servings 20 parts of trimethylolpropane phosphate 1.5 parts dinonyldiphenylamine 1 part of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester 0.6 parts of toluenetriazole 0.1 parts of polyether-modified silicone oil 1 part of rutile nano-TiO2 The specific preparation process includes the following steps: S1, TDP and trimethylolpropane phosphate are added to a reaction vessel, heated to 80°C under nitrogen protection and stirred until homogeneous to obtain mixture a.

[0040] S2, prepare an ethanol solution (concentration 6%) containing the antioxidant dinonyldiphenylamine and octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, add it dropwise slowly, and keep the reaction at the temperature for 2 hours to obtain mixture b.

[0041] S3, after cooling to 60℃, toluenetriazole, polyether-modified silicone oil and nano titanium dioxide are added in sequence, and the mixture is stirred for 45 minutes to obtain a mixed product; S4. After two-stage filtration of the mixed product (first using a 10μm filter and then a 0.5μm filter), it is de-volatile for 2 hours under residual pressure <0.1kPa to obtain a light yellow transparent liquid, which is the phosphate ester-based fire-resistant oil composition.

[0042] Example 4 This invention discloses a phosphate ester-based fire-resistant oil composition, the specific formulation of which, by mass parts, comprises: TDP (Industrial Grade) 80 servings 15 parts of trimethylolpropane phosphate 2 parts of dinonyldiphenylamine 1.2 parts of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester 0.4 parts of toluenetriazole 0.08 parts of polyether-modified silicone oil 0.07 parts of rutile nano-TiO2 The specific preparation process includes the following steps: S1, TDP and trimethylolpropane phosphate are added to a reaction vessel, heated to 90°C under nitrogen protection and stirred until homogeneous to obtain mixture a.

[0043] S2, prepare an ethanol solution (concentration 8%) containing the antioxidant dinonyldiphenylamine and octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, add it dropwise, and keep the reaction at the temperature for 1.5 hours to obtain mixture b.

[0044] S3, after cooling to 60℃, toluenetriazole, polyether-modified silicone oil and nano titanium dioxide are added in sequence, and the mixture is stirred for 45 minutes to obtain a mixed product; S4. After two-stage filtration of the mixed product (first using a 10μm filter and then a 0.5μm filter), it is de-volatile for 2 hours under residual pressure <0.1kPa to obtain a light yellow transparent liquid, which is the phosphate ester-based fire-resistant oil composition.

[0045] The present invention will be further illustrated below with reference to 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. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0046] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0047] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A phosphate ester-based fire-resistant oil composition, characterized in that, By mass fraction, its components include 70-85 parts of triaryl phosphate ester, 10-20 parts of polyol phosphate ester, 0.5-2.0 parts of organic amine primary antioxidant, 0.3-1.5 parts of hindered phenolic secondary antioxidant, 0.1-0.8 parts of benzotriazole derivative, 0.05-0.3 parts of polysiloxane surfactant, and 0.01-0.1 parts of nano titanium dioxide.

2. The phosphate ester-based fire-resistant oil composition according to claim 1, characterized in that, The triaryl phosphate ester is tolyl diphenyl phosphate ester.

3. The phosphate ester-based fire-resistant oil composition according to claim 1, characterized in that, The polyol phosphate ester is pentaerythritol phosphate ester or trimethylolpropane phosphate ester.

4. The phosphate ester-based fire-resistant oil composition according to claim 1, characterized in that, The primary organic amine antioxidant is dinonyldiphenylamine; the hindered phenolic secondary antioxidant is β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester; and the benzotriazole derivative is toluenetriazole.

5. The phosphate ester-based fire-resistant oil composition according to claim 1, characterized in that, The benzotriazole derivative is toluenetriazole; the polysiloxane surfactant is polyether-modified silicone oil.

6. A method for preparing a phosphate ester-based fire-resistant oil composition according to any one of claims 1 to 5, characterized in that, Includes the following steps: Triaryl phosphate and polyol phosphate were heated to a preset temperature under inert gas protection and stirred to obtain mixture a; Add an organic amine primary antioxidant diluted with ethanol and a hindered phenolic secondary antioxidant to the mixture, and react at a constant temperature to obtain mixture b; A benzotriazole derivative, a polysiloxane surfactant, and nano-titanium dioxide were added sequentially to mixture b, and the mixture was stirred continuously to obtain a mixed product. The mixture was filtered and vacuum devolatilized to obtain a phosphate-based fire-resistant oil composition.

7. The method for preparing a phosphate ester-based fire-resistant oil composition according to claim 6, characterized in that, The preset temperature is 80℃-90℃; the inert gas is nitrogen.

8. The method for preparing a phosphate ester-based fire-resistant oil composition according to claim 6, characterized in that, The total concentration of the organic amine primary antioxidant and the hindered phenolic secondary antioxidant in ethanol is 3wt%~8wt%; the isothermal reaction is carried out at a temperature of 80℃-90℃ for 1 hour to 2 hours.

9. The method for preparing a phosphate ester-based fire-resistant oil composition according to claim 6, characterized in that, The filtration process uses a 0.5μm~10μm filter element; the vacuum devolatilization is carried out under a residual pressure of less than 0.1kPa.

10. The use of the phosphate ester-based fire-resistant oil composition according to any one of claims 1 to 5 as a lubricant in electrical equipment.

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