Cyclotriphosphazene derivative and preparation method thereof as well as flame-retardant oil and preparation method thereof

Abstract

The invention discloses a cyclotriphosphazene derivative and a preparation method thereof, and a flame-retardant oil and a preparation method thereof. The structure of the cyclotriphosphazene derivative meets the formula 1: # imgabs0 #, R1 is alkyl with the carbon atom number larger than or equal to 3, R2 is fluorocarbon with the carbon atom number larger than or equal to 3, and the absolute value of the difference value of the carbon atom number of R1 and R2 is smaller than or equal to 3. Therefore, the prepared cyclotriphosphazene derivative has good flame retardant property, the cyclotriphosphazene derivative and the oil substance have good compatibility, and a mixture formed by the cyclotriphosphazene derivative and the oil substance has good fluidity.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial oils, and in particular relates to cyclotriphosphazene derivatives and a preparation method thereof, flame retardant oil and a preparation method thereof. Background Art

[0002] Mineral oil is widely used in industry as an insulating, cooling, lubricating or heat-conducting medium in electrical components. For example, mineral oil can be used as an insulating and cooling medium in high-voltage components (such as transformers and high-voltage switches). However, mineral oil has a low flash point and ignition point. Under the action of the high-temperature and high-voltage arc generated when a high-voltage component fails, it will quickly decompose, vaporize and flash. Therefore, it is very easy to cause a fire and cannot meet the use requirements of ultra-high voltage transformers and UHV transformers.

[0003] In the prior art, high-ignition-point insulating oils are mainly used to solve the above problems, such as insulating oils based on polychlorinated biphenyls (PCB), HTHS (High Temperature High Shear) oils, silicone oils, α oils, β oils, polyα-olefins, synthetic esters (Midel7131) and natural esters (environ FR3), etc. However, these high-ignition-point insulating oils are either highly toxic, or have poor heat dissipation, insulation and stability performance, or are too expensive, which prevents them from being widely used. Summary of the invention

[0004] In one aspect of the present invention, the present invention provides a cyclotriphosphazene derivative, the structure of which satisfies Formula 1:

[0005]

[0006] Wherein, R1 is an alkyl group having a carbon number greater than or equal to 3, R2 is a fluorocarbon group having a carbon number greater than or equal to 3, and the absolute value of the difference between the carbon numbers of R1 and R2 is less than or equal to 3. Thus, the cyclotriphosphazene derivative has good flame retardancy, good compatibility with oil substances, and the mixture formed with the oil substances has good fluidity.

[0007] According to the embodiments of the present application, the number of carbon atoms of R1 is 3 to 12. Thus, it is possible to ensure that the cyclotriphosphazene derivative has more hydrocarbon chains, the cyclotriphosphazene derivative and the oil substance have good compatibility, the mixture formed by the cyclotriphosphazene derivative and the oil substance has good fluidity, and the manufacturing cost of the cyclotriphosphazene derivative can be reduced.

[0008] According to the embodiments of the present application, the carbon number of R1 is 3 to 12. Thus, the cyclotriphosphazene derivatives can be guaranteed to have more carbon-fluorine chains, the cyclotriphosphazene derivatives and oil substances can have good flame retardant properties, and the manufacturing cost of the cyclotriphosphazene derivatives can be reduced.

[0009] According to the embodiments of the present application, the carbon number of R1 and R2 is independently less than or equal to 7, and the absolute value of the difference between the carbon number of R1 and R2 is less than or equal to 2. This is further conducive to ensuring that the prepared cyclotriphosphazene derivative has good flame retardant properties, the cyclotriphosphazene derivative and the oil substance have good compatibility, and the mixture formed by the cyclotriphosphazene derivative and the oil substance has good fluidity.

[0010] According to the embodiments of the present application, R1 and R2 have the same number of carbon atoms. This further helps to ensure that the prepared cyclotriphosphazene derivative has good flame retardant properties, the cyclotriphosphazene derivative and oil substances have good compatibility, and the mixture formed by the cyclotriphosphazene derivative and the oil substances has good fluidity.

[0011] In the second aspect of the present invention, the present invention provides a method for preparing the aforementioned cyclotriphosphazene derivative, comprising: mixing hexachlorocyclotriphosphazene, an alcohol containing an R1 group and an alcohol containing an R2 group in a solvent for reaction under the action of a catalyst to obtain the cyclotriphosphazene derivative. Thus, the aforementioned cyclotriphosphazene derivative can be prepared by a simple method.

[0012] According to an embodiment of the present application, the alcohol containing the R1 group satisfies the structural formula R1-OH, thereby improving the substitution effect of the R1 group and reducing the manufacturing cost.

[0013] According to an embodiment of the present application, the alcohol containing the R2 group satisfies the structural formula R2-OH. Thus, the substitution effect of the R2 group can be improved and the manufacturing cost can be reduced.

[0014] According to an embodiment of the present application, the catalyst includes potassium carbonate. Thus, the reaction rate of preparing cyclotriphosphazene derivatives can be increased.

[0015] According to an embodiment of the present application, the solvent includes at least one of dichloromethane, acetone, acetonitrile and pyridine, thereby improving the solubility of the reactants and the reaction yield.

[0016] According to an embodiment of the present application, the temperature of the mixed reaction is 65° C.-80° C., and the time of the mixed reaction is 24 h-48 h. Thus, the reaction rate of preparing cyclotriphosphazene derivatives can be increased.

[0017] In the third aspect of the present invention, the present invention provides a flame retardant oil, comprising the aforementioned cyclotriphosphazene derivative, and / or the cyclotriphosphazene derivative prepared by the aforementioned method, and an oily substance. Thus, the flame retardant oil has both good flame retardancy and excellent physical and chemical properties and electrical properties, and has good market application prospects.

[0018] According to an embodiment of the present application, the oil substance includes at least one of paraffin-based oil and naphthenic oil, thereby further improving the flame retardancy, physical and chemical properties and electrical properties of the flame retardant oil.

[0019] According to an embodiment of the present application, the mass ratio of the cyclotriphosphazene derivative to the oil substance in the flame retardant oil is (5-40): (60-95). This can improve the flame retardant effect of the flame retardant oil and reduce the manufacturing cost of the flame retardant oil.

[0020] In the fourth aspect of the present invention, the present invention proposes a method for preparing the aforementioned flame retardant oil, comprising mixing a cyclotriphosphazene derivative and an oil substance to obtain a flame retardant oil, wherein the temperature of the mixing treatment is 60°C-70°C, and the time of the mixing treatment is 8h-12h. Thus, the flame retardant oil can be obtained in a simple and easy manner, and it is easy to realize industrialization. DETAILED DESCRIPTION

[0021] In one aspect of the present invention, the present invention provides a cyclotriphosphazene derivative, the structure of which satisfies Formula 1:

[0022]

[0023] Wherein, R1 is an alkyl group having a carbon number greater than or equal to 3, R2 is a fluorocarbon group having a carbon number greater than or equal to 3, and the absolute value of the difference between the carbon numbers of R1 and R2 is less than or equal to 3. Thus, the prepared cyclotriphosphazene derivative has good flame retardant properties, the cyclotriphosphazene derivative and oil substances have good compatibility, and the mixture formed by the cyclotriphosphazene derivative and the oil substances has good fluidity.

[0024] The following is an explanation of the principle by which the above-mentioned cyclotriphosphazene derivatives can achieve the above-mentioned technical effects:

[0025] By setting R1 to an alkyl group with a carbon number greater than or equal to 3, it is ensured that the cyclotriphosphazene derivative has more hydrocarbon chains. According to the principle of like dissolves like, the cyclotriphosphazene derivative and oil substances have good compatibility. The cyclotriphosphazene derivative is a phosphazene compound with a special molecular structure. The phosphorus and nitrogen skeletons in the structure have a conjugated effect, so the chemical structure is stable, it is not easy to open the ring, and it has excellent thermal stability. In addition, the phosphorus and nitrogen elements have a synergistic effect and play a good flame retardant role in both the gas phase and the condensed phase. By setting R2 to a carbon The carbon-fluorine group with an atomic number greater than or equal to 3 ensures that the cyclotriphosphazene derivative has more fluorine elements. As a good flame retardant element, the fluorine element can improve the flame retardant properties of the cyclotriphosphazene derivative. At the same time, after the fluorination of the cyclotriphosphazene derivative, the cyclotriphosphazene derivative has a lower freezing point, thereby increasing the fluidity of the mixture formed by the cyclotriphosphazene derivative and the oily substance. When the absolute value of the difference in the number of carbon atoms of R1 and R2 is less than or equal to 3, the cyclotriphosphazene derivative has good flame retardant properties, and the cyclotriphosphazene derivative has good compatibility with the oily substance.

[0026] According to some embodiments of the present invention, the structure of R1 is (CH2) n CH3, n≥2.

[0027] As an example, the structure of R1 can be (CH2)2CH3, (CH2)3CH3, (CH2)4CH3, (CH2)5CH3, (CH2)6CH3, (CH2)7CH3, (CH2)8CH3, (CH2)9CH3, (CH2) 10 CH3, (CH2) 11 CH3, (CH2) 12 CH3……(CH2) n CH3.

[0028] According to some embodiments of the present invention, the structure of R2 is (CF2) n CF3, n≥2.

[0029] As an example, the structure of R2 can be (CF2)2CF3, (CF2)3CF3, (CF2)4CF3, (CF2)5CF3, (CF2)6CF3, (CF2)7CF3, (CF2)8CF3, (CF2)9CF3, (CF2) 10 CF3, (CF2) 11 CF3, (CF2) 12 CF3……(CF2) n CF3.

[0030] In some embodiments, the number of carbon atoms of R1 is 3-12. Therefore, controlling the number of carbon atoms of R1 within a certain range can ensure that the cyclotriphosphazene derivatives have more hydrocarbon chains, the cyclotriphosphazene derivatives and oil substances have good compatibility, and the mixture formed by the cyclotriphosphazene derivatives and oil substances has good fluidity, and the cost of preparing the cyclotriphosphazene derivatives can be avoided to be too high.

[0031] As the number of carbon atoms in R1 increases, the compatibility between cyclotriphosphazene derivatives and oil substances and the fluidity of the mixture formed by the cyclotriphosphazene derivatives and oil substances will gradually slow down. When the number of carbon atoms in R1 is greater than 12, the compatibility between cyclotriphosphazene derivatives and oil substances and the fluidity of the mixture formed by the cyclotriphosphazene derivatives and oil substances are less improved, and the cost of preparing cyclotriphosphazene derivatives will be greatly increased. When the number of carbon atoms in R1 is less than 3, the number of hydrocarbon chains of the cyclotriphosphazene derivatives is too small, the compatibility between the cyclotriphosphazene derivatives and oil substances is too poor, and the fluidity of the mixture formed by the cyclotriphosphazene derivatives and oil substances is too poor.

[0032] As an example, the number of carbon atoms in R1 can be 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12.

[0033] In some embodiments, the number of carbon atoms of R2 is 3-12. Controlling the number of carbon atoms of R2 within a certain range can ensure that the cyclotriphosphazene derivatives have more carbon-fluorine chains, and the cyclotriphosphazene derivatives and oil substances have good flame retardant properties, and can also avoid the high cost of preparing cyclotriphosphazene derivatives.

[0034] As the number of carbon atoms in R2 increases, the growth rate of the flame retardant properties of cyclotriphosphazene derivatives will gradually slow down. When the number of carbon atoms in R2 is greater than 12, the flame retardant properties of cyclotriphosphazene derivatives are less improved, and the cost of preparing cyclotriphosphazene derivatives will increase significantly. When the number of carbon atoms in R2 is less than 3, the number of hydrocarbon chains in cyclotriphosphazene derivatives is too small, and the flame retardant properties of cyclotriphosphazene derivatives and oil substances are too poor.

[0035] As an example, the number of carbon atoms in R2 can be 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12.

[0036] In some embodiments, the number of carbon atoms of R1 and R2 is independently less than or equal to 7, and the absolute value of the difference between the number of carbon atoms of R1 and R2 is less than or equal to 2. The same difference in the number of carbon atoms has a greater impact on the performance of the cyclotriphosphazene derivatives. For example, when the number of carbon atoms of R1 is 5 and the number of carbon atoms of R2 is 7, the absolute value of the difference in the number of carbon atoms of R1 and R2 is 2, and the difference of 2 carbon atoms has a greater impact on the compatibility between the cyclotriphosphazene derivatives and oil substances. When the number of carbon atoms of R1 is 10 and the number of carbon atoms of R2 is 12, the absolute value of the difference in the number of carbon atoms of R1 and R2 is 2. At this time, the difference of 2 carbon atoms has a smaller impact on the compatibility between the cyclotriphosphazene derivatives and oil substances. Therefore, when the number of carbon atoms of R1 and R2 is independently less than or equal to 7, it is conducive to ensuring that the prepared cyclotriphosphazene derivative has good flame retardant properties, the cyclotriphosphazene derivative and oil substances have good compatibility, and the mixture formed by the cyclotriphosphazene derivative and the oil substances has good fluidity.

[0037] As an example, when the number of carbon atoms of R1 and R2 is independently less than or equal to 7, the absolute value of the difference between the number of carbon atoms of R1 and R2 can be 0, 1 or 2. Preferably, the number of carbon atoms of R1 and R2 is the same, which is conducive to further improving the good flame retardant properties of the cyclotriphosphazene derivatives, the good compatibility of the cyclotriphosphazene derivatives and oil substances, and the mixture formed by the cyclotriphosphazene derivatives and oil substances has good fluidity.

[0038] In some embodiments, the present invention proposes a method for preparing a cyclotriphosphazene derivative. The method comprises: under the action of a catalyst, allowing hexachlorocyclotriphosphazene, an alcohol containing an R1 group and an alcohol containing an R2 group to react in a solvent to obtain a cyclotriphosphazene derivative. Thus, the cyclotriphosphazene derivative obtained by the above preparation method has good flame retardant properties, the cyclotriphosphazene derivative and oil substances have good compatibility, and the mixture formed by the cyclotriphosphazene derivative and the oil substances has good fluidity. At the same time, the above preparation method also has the advantages of easy availability of raw materials and simplicity, and is easy to realize industrialization.

[0039] In some embodiments, the above method includes: (1) mixing an alcohol containing an R1 group, an alcohol containing an R2 group and a solvent to obtain a mixed solution; (2) adding hexachlorocyclotriphosphazene to the mixed solution for reaction; (3) filtering, extracting and rotary evaporating the product obtained by the reaction to obtain a cyclotriphosphazene derivative.

[0040] Firstly, the alcohol containing the R1 group, the alcohol containing the R2 group and the solvent are mixed, and the alcohol containing the R1 group and the alcohol containing the R2 group can be uniformly dispersed in the solvent to obtain a uniformly mixed mixed liquid, and then the uniformly mixed mixed liquid is reacted with hexachlorocyclotriphosphazene, which is beneficial to improving the reaction rate and reaction effect, and finally the reaction product is filtered, extracted and rotary evaporated, which can improve the quality of the cyclotriphosphazene derivative.

[0041] In some embodiments, the structure of the alcohol containing the R1 group includes R1-OH.

[0042] As an example, the structure of the alcohol containing the R1 group can be CH3(CH2)2-OH, CH3(CH2)3-OH, CH3(CH2)4-OH, CH3(CH2)5-OH, CH3(CH2)6-OH, CH3(CH2)7-OH, CH3(CH2)8-OH, CH3(CH2)9-OH, CH3(CH2) 10 -OH, CH3(CH2) 11 CH3-OH, (CH2) 12 -OH……(CH2) n -OH.

[0043] In some embodiments, the structure of the alcohol containing the R2 group includes R2-OH.

[0044] As an example, the structure of the alcohol containing the R2 group can be CF3(CF2)2-OH, CF3(CF2)3-OH, CF3(CF2)4-OH, CF3(CF2)5-OH, CF3(CF2)6-OH, CF3(CF2)7-OH, CF3(CF2)8-OH, CF3(CF2)9-OH, CF3(CF2) 10 -OH, CF3(CF2) 11 CF3-OH, (CF2) 12 -OH……(CF2) n -OH.

[0045] In some embodiments, the catalyst includes potassium carbonate, thereby facilitating an increase in the reaction rate for preparing the cyclotriphosphazene derivative.

[0046] In some embodiments, the solvent includes at least one of dichloromethane, acetone, acetonitrile and pyridine, thereby further facilitating the improvement of the reaction rate for preparing the cyclotriphosphazene derivative.

[0047] In some embodiments, the reaction temperature for preparing the cyclotriphosphazene derivative is 65°C-80°C, for example, 65°C, 66°C, 67°C, 68°C, 69°C, 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C or 80°C. In other embodiments, the reaction time for preparing the cyclotriphosphazene derivative is 24h-48h, for example, 24h, 26h, 28h, 30h, 32h, 34h, 36h, 38h, 40h, 42h, 44h, 46h or 48h, etc. Thus, it is further beneficial for the hexachlorocyclotriphosphazene, the alcohol containing the R1 group and the alcohol containing the R2 group to react in the solvent.

[0048] In some embodiments, the reaction can be carried out in a three-necked flask. Thus, the reaction efficiency of preparing cyclotriphosphazene derivatives can be improved.

[0049] In some embodiments, the reaction is carried out under an inert gas atmosphere, thereby improving the reaction efficiency of preparing cyclotriphosphazene derivatives.

[0050] In the third aspect of the present invention, the present invention provides a flame retardant oil, comprising the aforementioned cyclotriphosphazene derivatives, and / or the cyclotriphosphazene derivatives prepared by the aforementioned method, and oil substances. The cyclotriphosphazene derivatives have excellent flame retardant effects, and the cyclotriphosphazene derivatives contain phosphorus and nitrogen conjugated skeleton structures, have excellent chemical stability and anti-puncture properties, and can improve the physical and chemical properties and electrical properties of the flame retardant oil. Therefore, the flame retardant oil has both good flame retardancy and excellent physical and chemical properties and electrical properties, and has good market application prospects.

[0051] In some embodiments, the oil substance includes at least one of paraffin-based oil and naphthenic oil, wherein the naphthenic oil includes mineral oil No. 25. This is further beneficial to improve the flame retardancy, physical and chemical properties and electrical properties of the flame retardant oil.

[0052] In some embodiments, the mass ratio of the cyclotriphosphazene derivative and the oil substance is (5-40): (60-95). Therefore, by controlling the mass ratio of the cyclotriphosphazene derivative and the oil substance within the above range, the flame retardant effect of the flame retardant oil can be improved, and the manufacturing cost of the flame retardant oil can be reduced.

[0053] In some embodiments, the flame-retardant oil can be used as insulating oil for power transformers, and can also be used as insulating oil for high-voltage electrical equipment such as capacitors and reactors.

[0054] In the fourth aspect of the present invention, the present invention proposes a method for preparing the flame retardant oil of the above embodiment, comprising mixing a cyclotriphosphazene derivative and an oil substance to obtain a flame retardant oil, wherein the temperature of the mixing treatment is 60°C-70°C, and the time of the mixing treatment is 8h-12h. Thus, the flame retardant oil can be obtained in a simple and easy way, and it is easy to realize industrialization.

[0055] In some embodiments, the method of mixing the cyclotriphosphazene derivative and the oil substance comprises mechanical stirring.

[0056] The embodiments of the present invention are described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention. In addition, if not explicitly stated, all reagents used in the following embodiments are commercially available, or can be synthesized according to this article or known methods, and the reaction conditions not listed are also easily available to those skilled in the art.

[0057] Example 1

[0058] This embodiment provides a method for preparing a flame retardant oil, comprising the following steps:

[0059] (1) Preparation of cyclotriphosphazene derivatives

[0060] Under mechanical stirring conditions, CH3(CH2)2-OH, CF3(CF2)2-OH and dichloromethane are added into a three-necked flask and mixed to obtain a mixed solution, wherein the mixing time is 1 hour; hexachlorocyclotriphosphazene and potassium carbonate are added into the mixed solution, and then nitrogen is introduced for reflux reaction to obtain a product, wherein the reflux temperature is 70°C and the reflux reaction time is 30 hours; the product is filtered, extracted and rotary evaporated to obtain a cyclotriphosphazene derivative;

[0061] (2) Preparation of flame retardant oil

[0062] Under the condition of mechanical stirring, 5 parts by weight of the cyclotriphosphazene derivative and 95 parts by weight of No. 25 mineral oil were mixed to obtain a flame retardant oil, wherein the mixing temperature was 65° C. and the mixing time was 12 h.

[0063] Example 2

[0064] This embodiment provides a method for preparing a flame retardant oil, comprising the following steps:

[0065] (1) Preparation of cyclotriphosphazene derivatives

[0066] Under mechanical stirring conditions, CH3(CH2)4-OH, CF3(CF2)4-OH and dichloromethane are added into a three-necked flask and mixed to obtain a mixed solution, wherein the mixing time is 1 hour; hexachlorocyclotriphosphazene and potassium carbonate are added into the mixed solution, and then nitrogen is introduced for reflux reaction to obtain a product, wherein the reflux temperature is 80° C. and the reflux reaction time is 24 hours; the product is filtered, extracted and rotary evaporated to obtain a cyclotriphosphazene derivative;

[0067] (2) Preparation of flame retardant oil

[0068] Under mechanical stirring conditions, 40 parts by weight of the cyclotriphosphazene derivative and 60 parts by weight of No. 25 mineral oil were mixed to obtain a flame retardant oil, wherein the mixing temperature was 65° C. and the mixing time was 12 h.

[0069] Example 3

[0070] This embodiment provides a method for preparing a flame retardant oil, comprising the following steps:

[0071] (1) Preparation of cyclotriphosphazene derivatives

[0072] Under mechanical stirring conditions, CH3(CH2)6-OH, CF3(CF2)6-OH and dichloromethane are added into a three-necked flask and mixed to obtain a mixed solution, wherein the mixing time is 1 hour; hexachlorocyclotriphosphazene and potassium carbonate are added into the mixed solution, and then nitrogen is introduced for reflux reaction to obtain a product, wherein the reflux temperature is 70° C. and the reflux reaction time is 30 hours; the product is filtered, extracted and rotary evaporated to obtain a cyclotriphosphazene derivative;

[0073] (2) Preparation of flame retardant oil

[0074] Under the condition of mechanical stirring, 10 parts by weight of the cyclotriphosphazene derivative and 90 parts by weight of No. 25 mineral oil were mixed to obtain a flame retardant oil, wherein the mixing temperature was 60° C. and the mixing time was 8 hours.

[0075] Example 4

[0076] This embodiment provides a method for preparing a flame retardant oil, comprising the following steps:

[0077] (1) Preparation of cyclotriphosphazene derivatives

[0078] Under mechanical stirring, CH3(CH2) 10 -OH, CF3(CF2) 10-OH and dichloromethane are added into a three-necked flask and mixed to obtain a mixed solution, wherein the mixing time is 1 hour; hexachlorocyclotriphosphazene and potassium carbonate are added into the mixed solution, and then nitrogen is introduced for reflux reaction to obtain a product, wherein the reflux temperature is 70° C. and the reflux reaction time is 30 hours; the product is filtered, extracted, and rotary evaporated to obtain a cyclotriphosphazene derivative;

[0079] (2) Preparation of flame retardant oil

[0080] Under mechanical stirring conditions, 40 parts by weight of the cyclotriphosphazene derivative and 60 parts by weight of No. 25 mineral oil were mixed to obtain a flame retardant oil, wherein the mixing temperature was 65° C. and the mixing time was 12 h.

[0081] Example 5

[0082] This embodiment provides a method for preparing a flame retardant oil, comprising the following steps:

[0083] (1) Preparation of cyclotriphosphazene derivatives

[0084] Under mechanical stirring conditions, CH3(CH2)6-OH, CF3(CF2)4-OH and dichloromethane are added into a three-necked flask and mixed to obtain a mixed solution, wherein the mixing time is 1 hour; hexachlorocyclotriphosphazene and potassium carbonate are added into the mixed solution, and then nitrogen is introduced for reflux reaction to obtain a product, wherein the reflux temperature is 70° C. and the reflux reaction time is 30 hours; the product is filtered, extracted and rotary evaporated to obtain a cyclotriphosphazene derivative;

[0085] (2) Preparation of flame retardant oil

[0086] Under the condition of mechanical stirring, 30 parts by weight of the cyclotriphosphazene derivative and 70 parts by weight of the paraffin-based oil were mixed to obtain a flame retardant oil, wherein the mixing temperature was 60° C. and the mixing time was 8 hours.

[0087] Comparative Example 1

[0088] This embodiment provides a method for preparing a flame retardant oil, comprising the following steps:

[0089] (1) Preparation of cyclotriphosphazene derivatives

[0090] Under mechanical stirring conditions, CH3CH2OH, CF3CF2OH and dichloromethane are added to a three-necked flask for mixing to obtain a mixed solution, wherein the mixing time is 1 hour; hexachlorocyclotriphosphazene and potassium carbonate are added to the mixed solution, and then nitrogen is introduced for reflux reaction to obtain a product, wherein the reflux temperature is 70° C. and the reflux reaction time is 30 hours; the product is filtered, extracted, and rotary evaporated to obtain a cyclotriphosphazene derivative;

[0091] (2) Preparation of flame retardant oil

[0092] Under the condition of mechanical stirring, 5 parts by weight of the cyclotriphosphazene derivative and 95 parts by weight of No. 25 mineral oil were mixed to obtain a flame retardant oil, wherein the mixing temperature was 65° C. and the mixing time was 12 h.

[0093] Comparative Example 2

[0094] This embodiment provides a method for preparing a flame retardant oil, comprising the following steps:

[0095] Under mechanical stirring conditions, 40 parts by weight of hexachlorocyclotriphosphazene flame retardant and 60 parts by weight of No. 25 mineral oil were mixed to obtain flame retardant oil, wherein the mixing temperature was 65° C. and the mixing time was 12 hours.

[0096] Comparative Example 3

[0097] This embodiment provides a method for preparing a flame retardant oil, comprising the following steps:

[0098] Under mechanical stirring conditions, 40 parts by weight of hexaphenoxy cyclotriphosphazene flame retardant (commercial DOPO derivative flame retardant, CAS No.: 1184-10-7) and 60 parts by weight of No. 25 mineral oil were mixed to obtain a flame retardant oil, wherein the mixing temperature was 65° C. and the mixing time was 12 h.

[0099] The combustion performance of the flame retardant oils obtained in Examples 1-5 and Comparative Examples 1-3 was tested by an oil pool fire test, and their electrical properties and physical and chemical properties were tested according to the national standard GB2536-2011. The results are shown in Table 1.

[0100] Oil pool fire test: Pour the sample oil into the oil pool, the sample oil volume is about 1 / 2 of the oil pool volume, the oil pool size is 10cm×10cm×5cm, then add 10ml of n-heptane igniter, ignite the igniter with an igniter, observe whether the sample oil can be ignited, repeat the ignition several times, and observe whether it can be ignited. Complete combustion: the sample oil is completely burned after one ignition; flammable: incomplete combustion after one ignition; difficult to burn: repeated ignition for several times, incomplete combustion, and self-extinguishing phenomenon; non-flammable: repeated ignition for several times, can not ignite.

[0101] GB2536-2011 specifies the test methods for the physical and chemical properties and electrical properties of mineral insulating oil for transformers. The present invention refers to this standard method to perform relevant performance tests.

[0102] Table 1 Performance test table of embodiments and comparative examples

[0103]

[0104] From the comparison between Examples 1-4 and Comparative Example 1, it can be seen that when the alkyl group in the cyclotriphosphazene derivative is too small, the compatibility between the cyclotriphosphazene derivative and the oil substance will deteriorate, and the fluidity of the flame retardant oil will deteriorate. When the carbon fluoride group in the cyclotriphosphazene derivative is too small, the flame retardant effect of the flame retardant oil will deteriorate.

[0105] From the comparison between Examples 1-4 and Comparative Example 2, it can be seen that compared with conventional cyclotriphosphazene flame retardants, the flame retardancy, fluidity, physical and chemical properties and electrical properties of flame retardant oils can be greatly improved by adding the cyclotriphosphazene derivatives of the present application.

[0106] From the comparison between Examples 1-4 and Comparative Example 3, it can be seen that compared with conventional commercial flame retardants, the flame retardancy, fluidity, physical and chemical properties and electrical properties of flame retardant oil can be greatly improved by adding the cyclotriphosphazene derivatives of the present application.

[0107] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A cyclotriphosphazene derivative, characterized in that: The structure of the cyclotriphosphazene derivative satisfies Formula 1: Wherein, R1 is an alkyl group having 3 or more carbon atoms, R2 is a fluorocarbon group having 3 or more carbon atoms, and the absolute value of the difference between the carbon atoms of R1 and R2 is less than or equal to 3.

2. The cyclotriphosphazene derivative according to claim 1, characterized in that The cyclotriphosphazene derivative satisfies at least one of the following conditions: The number of carbon atoms in R1 is 3-12; The number of carbon atoms in R2 is 3-12; The number of carbon atoms of R1 and R2 is independently less than or equal to 7, and the absolute value of the difference between the number of carbon atoms of R1 and R2 is less than or equal to 2.

3. The cyclotriphosphazene derivative according to claim 1 or 2, characterized in that R1 and R2 have the same number of carbon atoms.

4. A method for preparing the cyclotriphosphazene derivative according to any one of claims 1 to 3, characterized in that: The method comprises: under the action of a catalyst, mixing hexachlorocyclotriphosphazene, an alcohol containing an R1 group and an alcohol containing an R2 group in a solvent for reaction to obtain the cyclotriphosphazene derivative.

5. The method according to claim 4, characterized in that The alcohol containing the R1 group satisfies the structural formula R1-OH; And / or, the alcohol containing the R2 group satisfies the structural formula R2-OH.

6. The method according to claim 4 or 5, characterized in that: The catalyst includes potassium carbonate; and / or, the solvent comprises at least one of dichloromethane, acetone, acetonitrile and pyridine; And / or, the temperature of the mixed reaction is 65° C.-80° C., and the time of the mixed reaction is 24 h-48 h.

7. A flame retardant oil, characterized in that: The invention comprises the cyclotriphosphazene derivative according to any one of claims 1 to 3, and / or the cyclotriphosphazene derivative prepared by the method according to any one of claims 4 to 6, and oily substances.

8. The flame retardant oil according to claim 7, characterized in that: The oil substance includes at least one of paraffin-based oil and naphthenic oil.

9. The flame retardant oil according to claim 7 or 8, characterized in that: The mass ratio of the cyclotriphosphazene derivative to the oil substance in the flame retardant oil is (5-40): (60-95).

10. A method for preparing the flame retardant oil according to any one of claims 7 to 9, characterized in that: The method comprises the following steps: mixing cyclotriphosphazene derivatives and oil substances to obtain flame retardant oil, wherein the mixing temperature is 60° C.-70° C., and the mixing time is 8 h-12 h.

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