Composite stabilizers for 2-bromo-3,3,3-trifluoropropene and methods of use thereof

Abstract

The present application relates to a composite stabilizer of 2-bromo-3,3,3-trifluoropropene and its use method, the composite stabilizer comprises: a phenolic compound, a phosphite or thioester compound, an acid binding agent, the molar ratio of the amount of the three substances is 1:0.1~6:0.1~6, and the mass ratio of the amount and 2-bromo-3,3,3-trifluoropropene is 0.001~1.0:100. Through the interaction between the above stabilizer components, the rectification process of the product can effectively inhibit the deterioration problems such as the increase of acid value, the color change to yellow and the decrease of purity of 2-bromo-3,3,3-trifluoropropene, provide excellent long-term stability, facilitate its production, transportation and storage, and ensure its smooth application in the field of new fire extinguishing agent, organic synthesis and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical additives, in particular to a composite stabilizer for improving the stability of 2-bromo-3,3,3-trifluoropropene and a use method thereof. BACKGROUND

[0002] 2-bromo-3,3,3-trifluoropropene is an important organic compound, which is widely used in refrigerants, high-efficiency fire extinguishing agents, and organic synthesis. 2-bromo-3,3,3-trifluoropropene has a molecular structure containing a bromine atom and an unsaturated double bond, and has a low boiling point. In the field of fire extinguishing agents, it has the outstanding advantages of high fire extinguishing efficiency, clean and no residue, low atmospheric greenhouse effect value and ozone depletion value, and environmental friendliness, and is an ideal substitute for traditional halon fire extinguishing agents and perfluoroalkane fire extinguishing agents, with broad market application prospects.

[0003] Due to the presence of bromine atoms, 2-bromo-3,3,3-trifluoropropene is prone to free radical chain reactions, resulting in increased acid value, yellow color, and reduced purity, etc. Especially at high temperatures, even during the production rectification process, it will deteriorate. The characteristics of 2-bromo-3,3,3-trifluoropropene deteriorating easily bring great inconvenience to production, transportation, and storage, and seriously affect the quality and performance of the product, limiting its application in the field of fire extinguishing agents.

[0004] Currently, there are relevant literature materials introducing the synthesis method of 2-bromo-3,3,3-trifluoropropene and its application in new type fire extinguishing agents. For example, patents CN102206134A, CN103232319A, CN113087589A, etc. disclose some synthesis methods of 2-bromo-3,3,3-trifluoropropene; CN115888002A discloses a new type of clean and efficient gas fire extinguishing agent taking perfluorohexanone and 2-bromo-3,3,3-trifluoropropene as main components; in Fire Science and Technology, 41(7), 873-876 (2022), the fire extinguishing and cooling effect of 2-bromo-3,3,3-trifluoropropene on battery fire is studied; in Fire Science, 19(2), 60-67 (2010), the ratio of the composite fire extinguishing medium formed by 2-bromo-3,3,3-trifluoropropene and nitrogen and the critical fire extinguishing conditions under different ratios are studied; in Acta Chimica Sinica, 68(18), 1829-1836 (2010), the generation mechanism and amount of hydrogen fluoride in the fire extinguishing process of 2-bromo-3,3,3-trifluoropropene are studied. However, none of the above literature materials mentions the deterioration problems of 2-bromo-3,3,3-trifluoropropene such as increased acid value, yellow color, and reduced purity during synthesis, storage, and application. SUMMARY

[0005] In view of the above prior art, the present application provides a composite stabilizer for 2-bromo-3,3,3-trifluoropropene and a method for using the same, which can effectively inhibit the decomposition of 2-bromo-3,3,3-trifluoropropene and solve the problem of easy deterioration of 2-bromo-3,3,3-trifluoropropene during production, transportation, storage and application.

[0006] The technical solution of the present application can be summarized as follows:

[0007] The composite stabilizer for 2-bromo-3,3,3-trifluoropropene comprises a phenolic compound, a phosphite or thioester compound, and an acid-binding agent.

[0008] According to the present application, preferably, the molar ratio of the phenolic compound, the phosphite or thioester compound, and the acid-binding agent is 1:(0.1-6):(0.1-6).

[0009] According to the present application, preferably, the phenolic compound is an antioxidant comprising one or more aliphatic substituents, such as a monohydric phenol, a dihydric phenol, a polyhydric phenol, a hindered phenol, or a semi-hindered phenol.

[0010] Further preferably, the phenolic compound is a combination of one or more of p-hydroxyanisole, hydroquinone, 2-methylhydroquinone, 2-tert-butylhydroquinone, p-tert-butylcatechol, 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butyl-p-ethylphenol, 2,4-dimethyl-6-tert-butylphenol, tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid n-octadecyl ester, triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate], and 2,2'-methylenebis(4-methyl-6-tert-butylphenol).

[0011] More preferably, the phenolic compound is a combination of one or more of p-hydroxyanisole, 2-tert-butylhydroquinone, 2,6-di-tert-butyl-p-cresol, tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester, and the like.

[0012] According to the present application, preferably, the phosphite compound is an aliphatic or aromatic triester phosphite compound or a phosphite antioxidant.

[0013] Further preferably, the phosphite compound is a combination of one or more of triethyl phosphite, tributyl phosphite, trioctyl phosphite, triphenyl phosphite, tris[2,4-di-tert-butylphenyl]phosphite, bis(2,4-di-tert-butylphenol)pentaerythritol diphosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, and the like.

[0014] More preferably, the phosphite compound is one or a combination of triethyl phosphite, tributyl phosphite, tris [2,4-di-tert-butylphenyl] phosphite, etc.

[0015] According to the present application, preferably, the thioester compound is one or a combination of thiodipropionic acid bisn-dodecyl ester, thiodipropionic acid bisn-octadecyl ester, pentaerythritol tetrakis (3-laurylthiopropionate).

[0016] More preferably, the thioester compound is one or a combination of thiodipropionic acid bisn-dodecyl ester, thiodipropionic acid bisn-octadecyl ester.

[0017] According to the present application, preferably, the acid acceptor is one or a combination of aromatic, aliphatic, alicyclic or alkenyl epoxy compounds, further preferably phenyl glycidyl ether, n-butyl glycidyl ether, isobutyl glycidyl ether, ethylene glycol diglycidyl ether, butanediol diglycidyl ether, hexanediol diglycidyl ether, glycerol triglycidyl ether, allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, bis [(3,4-epoxycyclohexyl) methyl] adipate.

[0018] More preferably, the acid acceptor is one or a combination of glycerol triglycidyl ether, hexanediol diglycidyl ether, glycidyl methacrylate.

[0019] According to the present application, preferably, the molar ratio of the phenolic compound, the phosphite or thioester compound, and the acid acceptor is 1 : (1-3) : (1-5).

[0020] According to the present application, preferably, the composite stabilizer for 2-bromo-3, 3, 3-trifluoropropene comprises the following components in terms of molar parts:

[0021] p-Hydroxyanisole 1 part, tributyl phosphite 0.4-0.8 parts, allyl glycidyl ether 0.8-1.2 parts.

[0022] According to the present application, preferably, the composite stabilizer for 2-bromo-3, 3, 3-trifluoropropene comprises the following components in terms of molar parts:

[0023] Tetrakis [β- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester 1 part, tris [2, 4-di-tert-butylphenyl] phosphite 2-3 parts, hexanediol diglycidyl ether 4-6 parts.

[0024] According to the present application, preferably, the composite stabilizer for 2-bromo-3, 3, 3-trifluoropropene comprises the following components in terms of molar parts:

[0025] Tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] pentaerythritol ester 1 part, dioctadecylthiodipropionate 1 to 3 parts, hexanediol diglycidyl ether 4 to 6 parts.

[0026] According to the present application, the method for using the composite stabilizer of 2-bromo-3,3,3-trifluoropropene comprises the following steps:

[0027] The composite stabilizer is added to the product of 2-bromo-3,3,3-trifluoropropene, and the mass ratio of the composite stabilizer to 2-bromo-3,3,3-trifluoropropene is 0.001 to 1.0:100, preferably 0.005 to 0.5:100.

[0028] According to the present application, preferably, the composite stabilizer is added to the crude product of 2-bromo-3,3,3-trifluoropropene, and then further rectification treatment is performed.

[0029] Preferably, the alkali solution with a mass concentration of 3 to 30% is added to the crude product of 2-bromo-3,3,3-trifluoropropene or the product of 2-bromo-3,3,3-trifluoropropene with a high acid value, the mass ratio of the alkali solution to 2-bromo-3,3,3-trifluoropropene is 0.1 to 3:10, the alkali solution floats on the surface of 2-bromo-3,3,3-trifluoropropene, and then the rectification is started.

[0030] Preferably, the alkali solution is a sodium hydroxide solution, the mass concentration of the sodium hydroxide solution is 5 to 10%, and the mass ratio of the alkali solution to 2-bromo-3,3,3-trifluoropropene is 0.5 to 1.5:10.

[0031] According to the present application, the method for rectification treatment of 2-bromo-3,3,3-trifluoropropene comprises the following steps:

[0032] The alkali solution with a mass concentration of 3 to 30% is added to the crude product of 2-bromo-3,3,3-trifluoropropene or the product of 2-bromo-3,3,3-trifluoropropene with a high acid value, the mass ratio of the alkali solution to 2-bromo-3,3,3-trifluoropropene is 0.1 to 3:10, the alkali solution floats on the surface of 2-bromo-3,3,3-trifluoropropene, and then the rectification is started.

[0033] Preferably, the alkali solution is a sodium hydroxide solution, the mass concentration of the sodium hydroxide solution is 5 to 10%, and the mass ratio of the alkali solution to 2-bromo-3,3,3-trifluoropropene is 0.5 to 1.5:10.

[0034] According to the application, preferably, the composite stabilizer is dissolved in the 2-bromo-3,3,3-trifluoropropene crude product for rectification, the mass concentration of the composite stabilizer in the 2-bromo-3,3,3-trifluoropropene crude product is 1-20%, and preferably, a metering pump is used to continuously pump the composite stabilizer solution into the 2-bromo-3,3,3-trifluoropropene product fraction through the production pipeline during the rectification process, so that the 2-bromo-3,3,3-trifluoropropene product can be in time and sufficient contact with the composite stabilizer; further preferably, the concentration of the composite stabilizer solution is 5-10%.

[0035] Preferably, for the adding mode of the composite stabilizer, the composite stabilizer is directly pumped in sufficient amount through the metering pump during the rectification, or is first pumped in a small amount and then supplemented in the 2-bromo-3,3,3-trifluoropropene product fraction.

[0036] The application has the following beneficial effects:

[0037] 1. The application provides a composite stabilizer composition for 2-bromo-3,3,3-trifluoropropene and a use method thereof, and a combination of a phenolic compound, a phosphite or thioester compound and an acid-binding agent is selected as the composite stabilizer. The composite stabilizer components jointly act to significantly improve the stability of 2-bromo-3,3,3-trifluoropropene in the production, storage, transportation and application processes. The effect is better when the composite stabilizer is used in combination with the rectification treatment method.

[0038] 2. Experimental results show that the 2-bromo-3,3,3-trifluoropropene product prepared by using the composite stabilizer has excellent stability and can be stored for at least 5 years without deterioration under normal storage conditions. DETAILED DESCRIPTION

[0039] The application provides a composite stabilizer for 2-bromo-3,3,3-trifluoropropene and a use method thereof, which can effectively inhibit the decomposition of 2-bromo-3,3,3-trifluoropropene and solve the problem that 2-bromo-3,3,3-trifluoropropene is prone to deterioration in the production, transportation, storage and application processes.

[0040] The composite stabilizer for 2-bromo-3,3,3-trifluoropropene comprises a phenolic compound, a phosphite or thioester compound and an acid-binding agent.

[0041] In one or more preferred embodiments, the molar ratio of the phenolic compound, the phosphite or thioester compound and the acid-binding agent is 1:(0.1-6):(0.1-6).

[0042] According to the application, the three components of the composite stabilizer have obvious synergistic effect. The phenolic compound absorbs free radicals generated due to the deterioration of 2-bromo-3,3,3-trifluoropropene and prevents chain reactions;

[0043] In one or more preferred embodiments, the phenolic compound is an antioxidant comprising one or more aliphatic substituents, a monohydric phenol, a dihydric phenol, a polyhydric phenol, or a hindered phenol, a semi-hindered phenol;

[0044] Preferably, the phenolic compound is one or a combination of p-hydroxyanisole, hydroquinone, 2-methyl hydroquinone, 2-tert-butyl hydroquinone, p-tert-butyl catechol, 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butyl-p-ethylphenol, 2,4-dimethyl-6-tert-butylphenol, tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester, n-octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate], 2,2'-methylenebis(4-methyl-6-tert-butylphenol).

[0045] More preferably, the phenolic compound is one or a combination of p-hydroxyanisole, 2-tert-butyl hydroquinone, 2,6-di-tert-butyl-p-cresol, tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester, and the like.

[0046] According to the present application, the phosphite or thioester compound functions to solve the color contamination of the phenolic compound and to improve the discoloration of the sample during storage.

[0047] In one or more preferred embodiments, the phosphite compound is an aliphatic or aromatic triester phosphite compound or a phosphite antioxidant.

[0048] Preferably, the phosphite compound is one or a combination of triethyl phosphite, tributyl phosphite, trioctyl phosphite, triphenyl phosphite, tris[2,4-di-tert-butylphenyl]phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, and the like.

[0049] More preferably, the phosphite compound is one or a combination of triethyl phosphite, tributyl phosphite, tris[2,4-di-tert-butylphenyl]phosphite, and the like.

[0050] In one or more preferred embodiments, the thioester compound is a thioester antioxidant; further preferably, one or a combination of dilauryl thiodipropionate, dioctadecyl thiodipropionate, pentaerythritol tetrakis(3-laurylthiopropionate), and the like.

[0051] More preferably, the thioester compound is one or a combination of dilauryl thiodipropionate, dioctadecyl thiodipropionate, and the like.

[0052] According to the present invention, the function of the acid-binding agent is to absorb acidic substances produced during the deterioration process, control the product to a lower acid value, and also control the product color.

[0053] In one or more preferred embodiments, the acid-binding agent is an aromatic, aliphatic, alicyclic, or alkenyl epoxy compound, preferably one or a combination of several of the following: phenyl glycidyl ether, n-butyl glycidyl ether, isobutyl glycidyl ether, ethylene glycol diglycidyl ether, butanediol diglycidyl ether, hexanediol diglycidyl ether, glycerol triglycidyl ether, allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, and bis[(3,4-epoxycyclohexyl)methyl]adipate.

[0054] More preferably, the acid-binding agent is one or a combination of several of glycerol triglycidyl ether, hexanediol diglycidyl ether, and glycidyl methacrylate.

[0055] In one or more preferred embodiments, the molar ratio of phenolic compound, phosphite or thioester compound, and acid-binding agent is 1:(1-3):(1-5).

[0056] In one or more preferred embodiments, the composite stabilizer of 2-bromo-3,3,3-trifluoropropene comprises the following components in molar amounts:

[0057] 1 part p-hydroxyanisole, 0.4-0.8 parts tributyl phosphite, and 0.8-1.2 parts allyl glycidyl ether.

[0058] In one or more preferred embodiments, the composite stabilizer of 2-bromo-3,3,3-trifluoropropene comprises the following components in molar amounts:

[0059] One part of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], two to three parts of tris[2,4-di-tert-butylphenyl]phosphite, and four to six parts of hexanediol diglycidyl ether.

[0060] In one or more preferred embodiments, the composite stabilizer of 2-bromo-3,3,3-trifluoropropene comprises the following components in molar amounts:

[0061] One part of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1-3 parts of dioctadecyl thiodipropionate, and 4-6 parts of hexanediol diglycidyl ether.

[0062] According to the present invention, the method of using the above-mentioned 2-bromo-3,3,3-trifluoropropene composite stabilizer includes the following steps:

[0063] The composite stabilizer is added to the product of 2-bromo-3,3,3-trifluoropropene, and the mass ratio of the composite stabilizer to 2-bromo-3,3,3-trifluoropropene is 0.001-1.0:100, preferably 0.005-0.5:100.

[0064] In one or more preferred embodiments, the composite stabilizer is added to the crude product of 2-bromo-3,3,3-trifluoropropene, and then further rectification treatment is performed.

[0065] Preferably, the alkali solution with a mass concentration of 3-30% is added to the crude product of 2-bromo-3,3,3-trifluoropropene or the product of 2-bromo-3,3,3-trifluoropropene with a high acid value, the mass ratio of the alkali solution to 2-bromo-3,3,3-trifluoropropene is 0.1-3:10, the alkali solution floats on the surface of 2-bromo-3,3,3-trifluoropropene, and then the rectification is started.

[0066] Preferably, the alkali solution is a sodium hydroxide solution, the mass concentration of the sodium hydroxide solution is 5-10%, and the mass ratio of the alkali solution to 2-bromo-3,3,3-trifluoropropene is 0.5-1.5:10.

[0067] According to the present application, a rectification treatment method of 2-bromo-3,3,3-trifluoropropene is also provided, which aims to obtain a product with a low initial acid value to cooperate with the above-mentioned composite stabilizer to achieve the best effect.

[0068] The rectification treatment method of 2-bromo-3,3,3-trifluoropropene comprises the following steps:

[0069] The alkali solution with a mass concentration of 3-30% is added to the crude product of 2-bromo-3,3,3-trifluoropropene or the product of 2-bromo-3,3,3-trifluoropropene with a high acid value, the mass ratio of the alkali solution to 2-bromo-3,3,3-trifluoropropene is 0.1-3:10, the alkali solution floats on the surface of 2-bromo-3,3,3-trifluoropropene, and then the rectification is started.

[0070] In one or more preferred embodiments, the alkali solution is a sodium hydroxide solution, the mass concentration of the sodium hydroxide solution is 5-10%, and the mass ratio of the alkali solution to 2-bromo-3,3,3-trifluoropropene is 0.5-1.5:10.

[0071] In one or more preferred embodiments, the composite stabilizer is dissolved in the 2-bromo-3,3,3-trifluoropropene crude product for rectification, the mass concentration of the composite stabilizer in the 2-bromo-3,3,3-trifluoropropene crude product is 1-20%, and in the rectification process, the composite stabilizer solution is continuously pumped into the 2-bromo-3,3,3-trifluoropropene product fraction through the production pipeline by using a metering pump, so that the 2-bromo-3,3,3-trifluoropropene product can be timely and fully contacted with the composite stabilizer; further preferably, the concentration of the composite stabilizer solution is 5-10%.

[0072] Preferably, for the addition mode of the composite stabilizer, the composite stabilizer is directly pumped into the 2-bromo-3,3,3-trifluoropropene product fraction in a sufficient amount by using a metering pump during rectification, or the composite stabilizer is first pumped in a small amount and then supplemented in the 2-bromo-3,3,3-trifluoropropene product fraction.

[0073] In order for those skilled in the art to better understand the technical solutions of the present application, the composite stabilizer composition and the use method thereof provided by the present application will be described in detail below in conjunction with specific examples, and the protection scope of the present application is not limited by the following examples. Based on the examples in the present application, all other examples obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0074] In the examples, the raw materials used are all conventional commercially available products.

[0075] Example 1

[0076] Into a 10L rectification experimental kettle, 10Kg of 2-bromo-3,3,3-trifluoropropene crude product and 1Kg of 5% sodium hydroxide solution were added; 3g of p-hydroxyanisole, 3g of tributyl phosphite and 3g of allyl glycidyl ether were added into qualified 200g of 2-bromo-3,3,3-trifluoropropene product, and after being fully dissolved by stirring, a composite stabilizer solution was obtained; the heating was started, and the rectification was started; the purity of the fraction was monitored by gas chromatography, and when the purity of the fraction was qualified, the product was started to be collected; at the same time, the prepared composite stabilizer solution was continuously pumped into the production pipeline by using a uniform flow pump; the qualified product collected by rectification was dehydrated by using a molecular sieve, and then dry 2-bromo-3,3,3-trifluoropropene product to which the composite stabilizer was added was obtained; the 2-bromo-3,3,3-trifluoropropene product was sealed and stored at room temperature in the dark.

[0077] Example 2

[0078] Into a 10L rectification experiment kettle, 10Kg 2-bromo-3,3,3-trifluoropropene crude product and 2Kg 10% sodium hydroxide solution were added; 0.5g pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 0.5g tris[2,4-di-tert-butylphenyl]phosphite and 0.5g hexanediol diglycidyl ether were added into 200g 2-bromo-3,3,3-trifluoropropene product, after stirring and fully dissolving, a composite stabilizer solution was obtained; heating was started and rectification was started, the purity of the distillate was monitored by gas chromatography, when the purity of the distillate was qualified, the product was collected, at the same time, the prepared composite stabilizer solution was pumped into the collection pipeline at a constant speed by a uniform flow pump; the qualified product collected by rectification was dried by molecular sieve to obtain dry 2-bromo-3,3,3-trifluoropropene product with added composite stabilizer; the 2-bromo-3,3,3-trifluoropropene product was sealed and stored at room temperature and in the dark.

[0079] Example 3

[0080] The same as Example 2, except that the ratio of the composite stabilizer solution was 200g 2-bromo-3,3,3-trifluoropropene product dissolved 0.5g pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 0.5g dioctadecyl thiodipropionate and 0.5g hexanediol diglycidyl ether.

[0081] Comparative Example 1

[0082] Into a 10L rectification experiment kettle, 10Kg 2-bromo-3,3,3-trifluoropropene crude product and 1Kg 5% sodium hydroxide solution were added; heating was started and rectification was started, the purity of the distillate was monitored by gas chromatography, when the purity of the distillate was qualified, the product was collected; the qualified product collected by rectification was dried by molecular sieve, sealed and stored at room temperature and in the dark.

[0083] Comparative Example 2

[0084] The same as Example 2, except that the ratio of the composite stabilizer solution was 200g 2-bromo-3,3,3-trifluoropropene product dissolved 1g pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 0.5g dioctadecyl thiodipropionate.

[0085] Comparative Example 3

[0086] The same as Example 2, except that the ratio of the composite stabilizer solution was 200g 2-bromo-3,3,3-trifluoropropene product dissolved 1g pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 0.5g hexanediol diglycidyl ether.

[0087] Comparative Example 4

[0088] The same as Example 2, except that the distillation treatment amount is larger, the distillation time is longer, and no distillation treatment process is used. 3500 Kg of 2-bromo-3,3,3-trifluoropropene crude product is added to a 2500 L distillation kettle, and the distillation is started by turning on the heating. The purity of the distillate is monitored by gas chromatography. When the purity of the distillate is qualified, the product is collected. The qualified product collected by distillation is dried by molecular sieve to remove water. 175 g of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 175 g of tris[2,4-di-tert-butylphenyl]phosphite, and 175 g of hexanediol diglycidyl ether are metered and added, and stirred to dissolve completely, to obtain dry 2-bromo-3,3,3-trifluoropropene product with added composite stabilizer. The 2-bromo-3,3,3-trifluoropropene product is sealed and stored at room temperature in the dark.

[0089] Test Example 1

[0090] The color of each sample was observed, and the purity and acid value of each sample were detected according to the ASTM D8060-16 standard, and the results are shown in Table 1.

[0091] Table 1: Appearance and test results of each sample

[0092]

[0093]

[0094] As can be seen from the test data in Table 1, the sample with the added phenolic compound, phosphite or thioester compound, and acid-binding agent composite stabilizer has the best stability. The sample in Comparative Example 1 does not add any stabilizer, and obvious deterioration occurs, the color becomes yellow, the purity decreases, the acid value increases significantly, and there is a pungent odor. The sample in Comparative Example 2 uses a combination of phenolic compounds and thioester compounds as stabilizers, which has a certain stabilizing effect, but the increase in acid value is difficult to control, and high acid value further promotes sample deterioration and yellowing. The sample in Comparative Example 3 uses a combination of phenolic compounds and acid-binding agents as stabilizers, which can better play a stabilizing effect, and the acid value and purity are effectively controlled, but the appearance of the sample will be significantly darker. Comparative Example 4 adds a three-component composite stabilizer, but does not use a distillation treatment process. Especially in high-temperature environmental conditions, it is easy to cause the initial acid value of the sample to be too high, and the sample will gradually change color, affecting the use effect of the composite stabilizer.

[0095] In summary, the three components of the composite stabilizer have obvious synergistic effect: the role of phenolic substances is to absorb free radicals generated by the deterioration of 2-bromo-3,3,3-trifluoropropene, preventing chain reaction; the role of phosphite or thioester compounds is to solve the color pollution of phenolic compounds and improve the discoloration problem of the sample during storage; and the role of the acid binding agent is to absorb acidic substances generated during the deterioration process, control the low acid value of the product, and also control the color of the product; the above three components must be used together. In addition, 2-bromo-3,3,3-trifluoropropene is extremely prone to deterioration, especially in high temperature environment in summer, therefore, it is necessary to use the distillation process, which helps to eliminate the interference of acid value and ensure the use effect of the composite stabilizer and long-term stability.

[0096] Test Example 2

[0097] Long-term stability tests were conducted on the samples of Example 2 and Example 3, the color of the samples was observed regularly, and the purity and acid value of the samples were detected according to ASTM D8060-16 standard, and the results are shown in Table 2.

[0098] Table 2 Test results of long-term stability test

[0099]

[0100]

[0101] As can be seen from the test results in Table 2, for the samples of Example 2 and Example 3, after 5 years of storage at room temperature and in the dark, the color, purity and acid value have no big change, and the long-term stability is excellent.

[0102] The above is the preferred embodiment of the present application, which cannot limit the patent scope of the present application. For those skilled in the art, the technical solutions of the above embodiments can be modified, or some technical features can be replaced. Any modification, equivalent replacement, improvement, etc. directly or indirectly applied to other related technical fields within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for distilling 2-bromo-3,3,3-trifluoropropene, comprising using a composite stabilizer of 2-bromo-3,3,3-trifluoropropene. The composite stabilizer comprises the following components: phenolic compounds, phosphites or thioesters, and an acid-binding agent. The molar ratio of the phenolic compounds, phosphites or thioesters, and the acid-binding agent is 1:(0.1~6):(0.1~6). The phenolic compounds are p-hydroxyanisole, hydroquinone, 2-methylhydroquinone, 2-tert-butylhydroquinone, p-tert-butylcatechol, 2,6-di-tert-butyl-p-cresol, and 2,6-di-di-tert-butyl-p-cresol. One or a combination of several of the following: tert-butyl-p-acetol, 2,4-dimethyl-6-tert-butylphenol, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate], and 2,2'-methylenebis(4-methyl-6-tert-butylphenol]; The phosphite compounds mentioned are one or a combination of several of the following: triethyl phosphite, tributyl phosphite, trioctyl phosphite, triphenyl phosphite, tribisphenol A phosphite, tris[2,4-di-tert-butylphenyl] phosphite, bis(2,4-di-tert-butylphenol) pentaerythritol diphosphite, and bis(2,4-dicumylphenyl) pentaerythritol diphosphite. The thioester compounds mentioned are one or a combination of several of the following: disodecyl thiodipropionate, disoctyl thiodipropionate, and pentaerythritol tetra(3-lauryl thiopropionate). The acid-binding agent is one or a combination of several of the following: phenyl glycidyl ether, n-butyl glycidyl ether, isobutyl glycidyl ether, ethylene glycol diglycidyl ether, butanediol diglycidyl ether, hexanediol diglycidyl ether, glycerol triglycidyl ether, allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, and bis[(3,4-epoxycyclohexyl)methyl]adipate. Includes the following steps: Add a 3-30% (w / w) alkaline solution to the crude 2-bromo-3,3,3-trifluoropropylene product or a 2-bromo-3,3,3-trifluoropropylene product with a high acid value. The mass ratio of the alkaline solution to 2-bromo-3,3,3-trifluoropropylene is 0.1-3:10, with the alkaline solution floating on the surface of the 2-bromo-3,3,3-trifluoropropylene liquid. Dissolve the composite stabilizer in the crude 2-bromo-3,3,3-trifluoropropylene product and distill it. The mass concentration of the composite stabilizer in the crude 2-bromo-3,3,3-trifluoropropylene product is 1-20%. During the distillation process, use a metering pump to continuously pump the composite stabilizer solution into the 2-bromo-3,3,3-trifluoropropylene product fraction through the collection pipeline, so that the 2-bromo-3,3,3-trifluoropropylene product can contact the composite stabilizer in a timely and sufficient manner.

2. The distillation treatment method for 2-bromo-3,3,3-trifluoropropylene according to claim 1, characterized in that, The alkaline solution is a sodium hydroxide solution with a concentration of 5-10%, and the mass ratio of the alkaline solution to 2-bromo-3,3,3-trifluoropropene is 0.5-1.5:

10.

3. The distillation treatment method for 2-bromo-3,3,3-trifluoropropylene according to claim 1, characterized in that, For the addition of composite stabilizers, they can be directly and fully pumped in during distillation using a metering pump, or a small amount can be pumped in first and then added to the 2-bromo-3,3,3-trifluoropropylene product fraction.

4. The distillation treatment method for 2-bromo-3,3,3-trifluoropropylene according to claim 1, characterized in that, The molar ratio of phenolic compounds, phosphites or thioesters, and acid-binding agents is 1:(1~3):(1~5).

5. The distillation treatment method for 2-bromo-3,3,3-trifluoropropylene according to claim 1, characterized in that, A complex stabilizer for 2-bromo-3,3,3-trifluoropropene, comprising the following components in molar amounts: 1 part p-hydroxyanisole, 0.4-0.8 parts tributyl phosphite, and 0.8-1.2 parts allyl glycidyl ether.

6. The distillation treatment method for 2-bromo-3,3,3-trifluoropropylene according to claim 1, characterized in that, A complex stabilizer for 2-bromo-3,3,3-trifluoropropene, comprising the following components in molar amounts: One part of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], two to three parts of tris[2,4-di-tert-butylphenyl]phosphite, and four to six parts of hexanediol diglycidyl ether.

7. The distillation treatment method for 2-bromo-3,3,3-trifluoropropylene according to claim 1, characterized in that, A complex stabilizer for 2-bromo-3,3,3-trifluoropropene, comprising the following components in molar amounts: 1 part of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1-3 parts of dioctadecyl thiodipropionate, and 4-6 parts of hexanediol diglycidyl ether.

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