Purification method for preparing high-purity trifluorostyrene

Abstract

Provided in the present application is a purification method for preparing high-purity trifluorostyrene. The method comprises the following steps: step (A): providing low-purity trifluorostyrene having a purity of less than 99.10 weight%; step (B): adding a first additive and an optional second additive to the low-purity trifluorostyrene to form a mixture; and step (C): rectifying the mixture, so as to prepare the high-purity trifluorostyrene having a purity of greater than or equal to 99.70 weight%. Further provided in the present application is high-purity trifluorostyrene prepared by using the method. By adopting the purification method of the present application, high-purity trifluorostyrene required for special purposes can be efficiently synthesized at a low cost and a high yield.

Description

Purification method for preparing high-purity trifluorostyrene Technical Field

[0001] The present invention relates to the field of chemical industry, and more specifically to a novel method for purifying trifluorostyrene and the products obtained thereby. Background Art

[0002] α,β,β-trifluorostyrene (α,β,β-trifluorostyrene, also known as trifluorostyrene, abbreviated as TFS in English) is a fluorine-containing monomer that can be used to prepare fluorine-containing polymers and fluorine-containing intermediates. Fluorine-containing polymers (polytriflurostyrene, abbreviated as PTFS) with trifluorostyrene as the key monomer have good heat resistance, high transparency, good solubility, low dielectric loss, radiation resistance, and ion exchange activation, thus having very wide application potential in proton exchange membranes, ion exchange membranes, optoelectronic communications, filter materials, microelectronics and other fields. Currently, many applications hope to use trifluorostyrene with the highest possible purity as a raw material for polymerization reactions, for example, it is hoped to obtain a purity of up to 99.50% or more, more preferably up to 99.70% or more, to meet people's increasingly stringent performance requirements for polytrifluorostyrene.

[0003] Given the current situation, obtaining extremely high-purity trifluorostyrene on an industrial scale is an extremely urgent but unresolved problem. First, mature processes for mass-producing trifluorostyrene on an industrial scale are quite rare. Currently, only the applicant, San Ai Fu Company, has achieved industrial production of trifluorostyrene on a scale of over 100 tons. The purity of trifluorostyrene compounds obtained by such industrial-scale production is quite low, often only around 50-70%. This low-purity trifluorostyrene is quite undesirable for subsequent polymerization reactions. To this end, R&D personnel have conducted extensive research and attempted to further purify the crude trifluorostyrene by optimizing various purification processes and designing purification equipment. However, no matter how hard the existing technology tries, the purity of the purified trifluorostyrene obtained is always less than 99.5%. This purity is not suitable for the synthesis of electronic-grade, battery-grade, or optical-grade polymers or related products, and cannot meet product requirements.

[0004] Therefore, there is an urgent need in this field to develop a novel purification process to increase trifluorostyrene to the required purity so that it can meet the application needs in the fields of high-performance new materials, electronic chemicals, battery chemicals, etc.

[0005] Summary of the Invention

[0006] In response to the above problems, the applicant has developed a novel purification method through long-term and in-depth research. This method can improve the purity of trifluorostyrene to the required level mentioned above. At the same time, this method can be carried out in a continuous manner. The method of the present application has the advantages of high product purity, high process safety, continuous operation, and high product yield, thus completing the present invention.

[0007] The first aspect of the present application provides a purification method for preparing high-purity trifluorostyrene, the method comprising the following steps:

[0008] Step (A): providing low-purity trifluorostyrene;

[0009] Step (B): adding a first additive and an optional second additive to the low-purity trifluorostyrene to form a mixture; and

[0010] Step (C) distilling the mixture to obtain the high-purity trifluorostyrene;

[0011] The purity of the low-purity trifluorostyrene is less than 99.50% by weight, and the purity of the high-purity trifluorostyrene is ≥99.70% by weight;

[0012] The first additive is a compound comprising at least one structure shown in Formula I:

[0013] where R 1 C3-C 16 branched alkyl groups,

[0014] R 2 A group selected from the following: a covalent bond, a C1-C 16 Straight chain alkyl, C3-C 16 Branched alkyl, C1-C 16 Straight chain alkylene,

[0015] R 3 A group selected from the following: a covalent bond, a hydrogen atom, a C1-C 16 Straight chain alkyl, C3-C 16 Branched alkyl, C1-C 16 Straight chain alkylene, C3-C 16 Branched alkylene, C1-C 16 Straight chain alkylene acyl, C3-C 16 Branched chain alkylene acyl, C1-C 16 Straight chain alkylene acyloxy, C3-C 16 branched alkylene acyloxy,

[0016] Optionally, the first additive comprises a remainder other than at least one structure represented by formula I, and the at least one structure represented by formula I is connected via R 2 or R 3 connected to the remaining portion;

[0017] The second additive is selected from the group consisting of: phosphoric acid, phosphate ester, phosphorous acid, and phosphite ester.

[0018] According to one embodiment of the first aspect of the present application, the first additive comprises one, two, three or four structures represented by formula I, and the remaining portion of the first additive is selected from at least one of the following: C(CH2O-)4, C(CH2-)4, -O-CH(CH2O-)2, -CH(CH2-)2, (C1-C22) alkyl, (C1-C22) alkoxy, (C1-C22) alkylene, -O-(C1-C22) alkylene-O-, -NH-(C1-C22) alkylene-NH-, -NH-NH-, -NH2, -N(C1-C16 alkyl)2, -C(C1-C16 alkyl)2-, -(C1-C22) alkylene-C(C1-C16 alkyl)2-(C1-C22) alkylene, -(C1-C22) alkylene-C3-C16 heterocycloalkylene -(C1-C22)alkylene-, -(C1-C22)alkylene-C(C1-C16alkyl)2-C3-C16heterocycloalkylene-C(C1-C16alkyl)2-(C1-C22)alkylene-, -(C1-C22)alkylene-C6-C16arylene-(C1-C22)alkylene-, -(C1-C22)alkylene-C(C1-C16alkyl)2-C6-C16 Arylene-C(C1-C16 alkyl)2-(C1-C22)alkylene-, -(C1-C22)alkylene-C6-C16 heteroarylene-(C1-C22)alkylene-, -(C1-C22)alkylene-C(C1-C16 alkyl)2-C6-C16 heteroarylene-C(C1-C16 alkyl)2-(C1-C22)alkylene-, -O-(C2-C12 alkylene-O) n -, -O-(C2-C12 alkylene-O) n -H, -C(C1-C16 alkyl)[C(O)O-(C2-C12 alkylene-O) n -H]-, wherein n is an integer from 1 to 12.

[0019] According to another embodiment of the first aspect of the present application, the first additive includes at least one of the following: tetrakis{β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate}pentaerythritol, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl, 1,3,5-trimethyl-2,4,6(3,5-tert-butyl-4-hydroxybenzyl)benzene, 2,6-di-tert-butyl-4-methyl-phenol, 3,9-bis[2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)-propionyloxy]-1, [1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, 2,2'-methylenebis(4-methyl-6-tert-butyl-phenol), N,N'-1,6-hexylene-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine, bis[3-(1,1-dimethylethyl)-4-hydroxy-5-methylphenylpropionic acid]triethylene glycol.

[0020] According to another embodiment of the first aspect of the present application, the second additive is selected from at least one of the following: phosphoric acid, tri(C1-C16 alkyl) phosphate, tri(C6-C16 aryl) phosphate, tetra(C6-C32 aryl)bisphosphite, tri(C6-C22 aryl) phosphite, di(C6-C22 aryl) pentaerythritol bisdiphosphite, and di(C1-C22 alkyl) pentaerythritol bisdiphosphite.

[0021] According to another embodiment of the first aspect of the present application, the second additive is selected from at least one of the following: phosphoric acid, triphenyl phosphate, trimethyl phosphate, trioctyl phosphate, tridecyl phosphate, tri(dodecanol) phosphate, tri(hexadecanol) phosphate, triphenyl phosphite, trimethyl phosphite, trioctyl phosphite, tridecyl phosphite, tri(dodecanol) phosphite, tri(hexadecanol) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, tetra ... tert-butylphenyl-4,4'-biphenyl) bisphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol bisphosphite, bis(2,6-di-tert-butyl-4-tolyl)pentaerythritol bisphosphite, bis(octadecyl)pentaerythritol diphosphite, bis(2,4-dicumylphenyl)pentaerythritol bisphosphite, 2,2'-ethylenebis(4,6-di-tert-butylphenyl)fluorophosphite, 2,4,6-tri-tert-butylphenylpentaerythritol bisphosphite.

[0022] According to another embodiment of the first aspect of the present application, based on 100 parts by mass of the first additive, the amount of the second additive is 0 to 150 parts by mass.

[0023] According to another embodiment of the first aspect of the present application, based on 100 parts by mass of the total mass of the low-purity trifluorostyrene, the total amount of the first additive and the second additive is 0.01 to 0.15 parts by mass.

[0024] According to another embodiment of the first aspect of the present application, based on 100 parts by mass of the first additive, the amount of the second additive is 10 to 70 parts by mass. According to another embodiment of the first aspect of the present application, based on 100 parts by mass of the total mass of the low-purity trifluorostyrene, the total amount of the first additive and the second additive is 0.04 to 0.06 parts by mass.

[0025] According to another embodiment of the first aspect of the present application, the method is carried out continuously in a distillation tower. According to another embodiment of the first aspect of the present application, the temperature in the distillation tower is 10-90°C. According to another embodiment of the first aspect of the present application, the pressure in the distillation tower is 0-200 kPa. According to another embodiment of the first aspect of the present application, the number of plates in the distillation tower is 10-50.

[0026] A second aspect of the present application provides high-purity trifluorostyrene, which is prepared by the method of the present application, wherein the purity of the high-purity trifluorostyrene is ≥99.70% by weight. DETAILED DESCRIPTION

[0027] " Scope " disclosed herein is limited in the form of lower limit and upper limit, and given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of special range. The scope limited in this way can be to include end value or not include end value, and can be arbitrarily combined, that is, any lower limit can form a scope with any upper limit combination. For example, if the scope of 60-120 and 80-110 is listed for a particular parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range value 1 and 2 are listed, and if the maximum range value 3,4 and 5 are listed, then the following range can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In this application, unless otherwise specified, the numerical range " ab " represents the abbreviation of any real number combination between a and b, wherein a and b are all real numbers. For example, a numerical range of "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is simply an abbreviation for these numerical combinations. Furthermore, when a parameter is expressed as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0028] In this application, unless otherwise specified, all embodiments and preferred embodiments mentioned herein can be combined with each other to form a new technical solution.

[0029] In this application, unless otherwise specified, all technical features and preferred features mentioned herein can be combined with each other to form a new technical solution.

[0030] In this application, unless otherwise specified, all steps mentioned herein may be performed sequentially or randomly, but are preferably performed sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0031] In this application, unless otherwise specified, the terms "include" and "comprising" used herein may be open-ended or closed-ended. For example, "include" and "comprising" may mean that other components not listed may also be included or that only the listed components are included.

[0032] In the description of this article, it should be noted that, unless otherwise specified, “above” and “below” are inclusive of the number themselves, and “several” in “one or several” means two or more.

[0033] In the description herein, unless otherwise indicated, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0034] Herein, unless otherwise specified, percentages (%) or parts refer to percentages or parts by weight relative to the composition.

[0035] Herein, unless otherwise stated, the sum of the contents of the various components in the composition is 100%.

[0036] Herein, unless otherwise stated, the sum of the parts of each component in the composition may be 100 parts by weight.

[0037] In this context, unless otherwise stated, "a combination thereof" means a multi-component mixture of the elements mentioned, for example a mixture of two, three, four and up to the maximum possible multi-component mixture.

[0038] If not specifically stated, the terms "a" and "an" used in this specification mean "at least one".

[0039] For the purpose of convenience in this application, the trifluorostyrene to be purified, which is the object of the purification method of the present invention, is referred to as "low-purity trifluorostyrene", and the trifluorostyrene treated by the purification method of the present invention is referred to as "high-purity trifluorostyrene". Note that the "low purity" and "high purity" used herein are relative to each other, and the purity of "high-purity trifluorostyrene" is relatively higher than that of "low-purity trifluorostyrene". For example, according to one embodiment of the present application, the purity of the low-purity trifluorostyrene is less than 99.50%, for example, ≤99.40%, or ≤99.30%, or ≤99.20%, or ≤99.10%, or ≤99.00%, or ≤98.80%, or ≤98.50%, or ≤98.00%, or ≤97.50%, or ≤97.00%, or ≤96.50%, or ≤96.00%, or ≤95.50%, or ≤95.00%, Or ≤94.00%, or ≤92.00%, or ≤90.00%, or ≤88.00%, or ≤85.00%, or ≤82.00%, or ≤80.00%, or ≤75.00%, or ≤70.00%, or ≤65.00%, or ≤60.00%, or ≤55.00%, or ≤50.00%, or ≤45.00%, or ≤40.00%, or can be within the numerical range obtained by combining any two of the above end values. For example, according to another embodiment of the present application, the purity of the high-purity trifluorostyrene is ≥99.70%, for example ≥99.75%, or ≥99.80%, or ≥99.82%, or ≥99.84%, or ≥99.85%, or ≥99.86%, or ≥99.88%, or ≥99.90%, or ≥99.91%, or ≥99.92%, or ≥99.95%, or ≥99.96%, or ≥99.97%, or ≥99.98%, or ≥99.99%, or can be within the range of values ​​obtained by combining any two of the above end values. In the present application, when describing the purity of trifluorostyrene, the percentages used are weight percentages.

[0040] One of the inventive points of the present application is that a specially selected first additive, or a combination of the first additive and the second additive is added to "low-purity trifluorostyrene" to obtain a mixture (or mixed liquid), and then the mixture is distilled, preferably in a continuous manner, to obtain the "high-purity trifluorostyrene".

[0041] According to one embodiment of the present application, a purification method for preparing high-purity trifluorostyrene is provided, the method comprising the following steps:

[0042] Step (A): providing low-purity trifluorostyrene;

[0043] Step (B): adding a first additive, or a combination of the first additive and a second additive (i.e., the second additive is optional and may be absent or added to the low-purity trifluorostyrene together with the first additive) to the low-purity trifluorostyrene to form a mixture; and

[0044] In step (C), the mixture is distilled to obtain the high-purity trifluorostyrene.

[0045] According to one embodiment of the present application, for the step (A), the low-purity trifluorostyrene can be provided in any suitable manner. For example, the low-purity trifluorostyrene can be purchased from a supplier, or the low-purity trifluorostyrene can be synthesized according to any suitable process. For example, low-purity trifluorostyrene as a commercial product can be purchased from the applicant San Ai Fu Company as the starting material for the purification process of the present application. According to an exemplary embodiment, the low-purity trifluorostyrene can be synthesized by the technology described in the patent application CN202111452390.2 of the applicant San Ai Fu Company.

[0046] According to one embodiment of the present application, for step (B), the first additive used is a compound comprising at least one structure represented by formula I:

[0047] According to one embodiment of the present application, R in Formula I 1 C3-C 16 Branched alkyl; for example, C3-C 12 branched alkyl; or C3-C8 branched alkyl; or C3-C6 branched alkyl; most preferably R in formula I 1 For tert-butyl.

[0048] According to one embodiment of the present application, R 2 A group selected from the following: a covalent bond, a C1-C 16 Straight chain alkyl, C3-C 16 Branched alkyl, C1-C16 Straight chain alkylene; or R 2 A group selected from the following: a covalent bond, a C1-C 12 Straight chain alkyl, C3-C 12 Branched alkyl, C1-C 12 Straight chain alkylene; or R 2 A group selected from the following: a covalent bond, a C1-C8 straight chain alkyl group, a C3-C8 branched alkyl group, a C1-C8 straight chain alkylene group; or R 2 A group selected from the following: a covalent bond, a C1-C6 straight chain alkyl, a C3-C6 branched alkyl, a C1-C6 straight chain alkylene. 2 It is tert-butyl, methyl, -CH2- or a covalent bond.

[0049] According to one embodiment of the present application, R3 is selected from the following groups: covalent bond, hydrogen atom, C1-C 16 Straight chain alkyl, C3-C 16 Branched alkyl, C1-C 16 Straight chain alkylene, C3-C 16 Branched alkylene, C1-C 16 Straight chain alkylene acyl, C3-C 16 Branched chain alkylene acyl, C1-C 16 Straight chain alkylene acyloxy, C3-C 16 Branched alkylene acyloxy; or R 3 A group selected from the following: a covalent bond, a hydrogen atom, a C1-C 12 Straight chain alkyl, C3-C 12 Branched alkyl, C1-C 12 Straight chain alkylene, C3-C 12 Branched alkylene, C1-C 12 Straight chain alkylene acyl, C3-C 12 Branched chain alkylene acyl, C1-C 12 Straight chain alkylene acyloxy, C3-C 12 Branched alkylene acyloxy; or R 3 A group selected from the following: a covalent bond, a hydrogen atom, a C1-C8 straight-chain alkyl group, a C3-C8 branched-chain alkyl group, a C1-C8 straight-chain alkylene group, a C3-C8 branched-chain alkylene group, a C1-C8 straight-chain alkylene acyl group, a C3-C8 branched-chain alkylene acyl group, a C1-C8 straight-chain alkylene acyloxy group, a C3-C8 branched-chain alkylene acyloxy group; or R 3 A group selected from the following: a covalent bond, a hydrogen atom, a C1-C6 straight-chain alkyl group, a C3-C6 branched alkyl group, a C1-C6 straight-chain alkylene group, a C3-C6 branched-chain alkylene group, a C1-C6 straight-chain alkylene acyl group, a C3-C6 branched-chain alkylene acyl group, a C1-C6 straight-chain alkylene acyloxy group, and a C3-C6 branched-chain alkylene acyloxy group.

[0050] According to one embodiment of the present application, the first additive comprises one, two, three, four, five or six structures represented by Formula I. According to another embodiment of the present application, the first additive comprises the remaining portion other than at least one structure represented by Formula I, and the at least one structure represented by Formula I is connected via R 2 Or R3 is connected to the remaining part. According to another embodiment of the present application, the remaining part of the first additive is selected from at least one of the following: C(CH2O-)4, C(CH2-)4, -O-CH(CH2O-)2, -CH(CH2-)2, (C1-C22) alkyl, (C1-C22) alkoxy, (C1-C22) alkylene, -O-(C1-C22) alkylene-O-, -NH-(C1-C22) alkylene-NH-, -NH-NH-, -NH2, -N(C1-C16 alkyl)2, -C(C1-C16 alkyl)2-, -(C1-C22) alkylene-C(C1-C16 alkyl)2-(C1-C22) alkylene, -(C1-C22) alkylene-C3-C16 heterocycloalkylene-(C1-C22) alkylene-, -(C 1-C22)alkylene-C(C1-C16alkyl)2-C3-C16heterocycloalkylene-C(C1-C16alkyl)2-(C1-C22)alkylene-, -(C1-C22)alkylene-C6-C16arylene-(C1-C22)alkylene-, -(C1-C22)alkylene-C(C1-C16alkyl)2-C6-C16arylene-C(C1 -C16 alkyl)2-(C1-C22)alkylene-, -(C1-C22)alkylene-C6-C16 heteroarylene-(C1-C22)alkylene-, -(C1-C22)alkylene-C(C1-C16 alkyl)2-C6-C16 heteroarylene-C(C1-C16 alkyl)2-(C1-C22)alkylene-, -O-(C2-C12 alkylene-O) n -, -O-(C2-C12 alkylene-O) n -H, -C(C1-C16 alkyl)[C(O)O-(C2-C12 alkylene-O) n -H]-, wherein n is an integer from 1 to 12, for example, n can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12.

[0051] According to one embodiment of the present application, the first additive includes at least one of the following: tetrakis{β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate}pentaerythritol, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl, 1,3,5-trimethyl-2,4,6(3,5-tert-butyl-4-hydroxybenzyl)benzene, 2,6-di-tert-butyl-4-methyl-phenol, 3,9-bis[2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)-propionyloxy]-1,1-diol methylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, 2,2'-methylenebis(4-methyl-6-tert-butyl-phenol), N,N'-1,6-hexylene-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine, bis[3-(1,1-dimethylethyl)-4-hydroxy-5-methylphenylpropionic acid]triethylene glycol.

[0052] According to a preferred embodiment of the present application, the first additive includes at least one of the following: pentaerythritol tetrakis{β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, octadecylβ-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0053] According to one embodiment of the present application, in step (B) of the method of the present application, only the first additive is added to the low-purity trifluorostyrene without adding the second additive. According to another embodiment of the present application, in step (B) of the method of the present application, the first additive and the second additive are added to the low-purity trifluorostyrene at the same time.

[0054] According to one embodiment of the present application, the second additive is selected from the group consisting of: phosphoric acid, phosphate ester, phosphorous acid, and phosphite. In the present application, "phosphoric acid" refers to the compound P(=O)(OH)3, and phosphate ester refers to the ester of phosphoric acid and one or more alcohols; "phosphorous acid" refers to the compound P(OH)3, and phosphite refers to the ester of phosphorous acid and one or more alcohols. According to one embodiment of the present application, the second additive is selected from at least one of the following: phosphoric acid, tri(C1-C16 alkyl) phosphate, tri(C6-C16 aryl) phosphate, tetra(C6-C32 aryl) bisphosphite, tri(C6-C22 aryl) phosphite, di(C6-C22 aryl) pentaerythritol bisdiphosphite, and di(C1-C22 alkyl) pentaerythritol bisdiphosphite. According to another embodiment of the present application, the second additive is selected from at least one of the following: phosphoric acid, triphenyl phosphate, trimethyl phosphate, trioctyl phosphate, tridecyl phosphate, tri(dodecanol) phosphate, tri(hexadecanol) phosphate, triphenyl phosphite, trimethyl phosphite, trioctyl phosphite, tridecyl phosphite, tri(dodecanol) phosphite, tri(hexadecanol) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, tetra ... The second additive is tris(2,4-di-tert-butylphenyl) phosphite.

[0055] According to one embodiment of the present application, based on the mass of the first additive as 100 parts by mass, the amount of the second additive is 0 to 150 parts by mass, for example, 0 parts by mass or 10 to 120 parts by mass, or 15 to 100 parts by mass, or 18 to 80 parts by mass, or 20 to 50 parts by mass, or 25 to 40 parts by mass, or 25 to 30 parts by mass, or within the numerical range obtained by combining any two of the above end values.

[0056] According to one embodiment of the present application, based on the total mass of the low-purity trifluorostyrene as 100 parts by mass, the total amount of the first additive and the second additive is 0.01 to 0.15 parts by mass, for example, 0.02-0.14 parts by mass, or 0.03-0.12 parts by mass, or 0.04-0.10 parts by mass, or 0.04-0.08 parts by mass, or 0.04-0.06 parts by mass, or 0.04-0.05 parts by mass, or within the numerical range obtained by combining any two of the above end values.

[0057] According to one embodiment of the present application, a mixture (or mixed liquid) is obtained by adding a first additive and an optional second additive to low-purity trifluorostyrene, and one or more of the first additive and the second additive can be dissolved or dispersed (e.g., suspended) in the low-purity trifluorostyrene.

[0058] According to one embodiment of the present application, step (C) is carried out in a distillation column, preferably in a continuous manner. For example, the purification temperature used in the distillation column is 10-90°C, such as 20-80°C, or 30-70°C, or 40-60°C, or 45-50°C, or within a numerical range obtained by combining any two of the above end values.

[0059] According to another embodiment of the present application, the process pressure in the distillation column can be 0-200 kPa, for example, 5-180 kPa, or 10-150 kPa, or 15-120 kPa, or 18-100 kPa, or 20-80 kPa, or 25-70 kPa, or 30-60 kPa, or 40-50 kPa, or within a numerical range obtained by combining any two of the above values. The above pressures are absolute pressures.

[0060] According to another embodiment of the present application, the number of theoretical plates of the distillation tower can be 10-50, or 15-45, or 20-40, or 25-40, or 30-35, or within the numerical range obtained by combining any two of the above end values.

[0061] By adopting the purification method developed by the present invention, a high-purity trifluorostyrene product can be prepared, and the yield of the high-purity styrene can be as high as 94-99%, which is impossible to achieve by various purification methods developed in the prior art. This significantly improves the production efficiency of the high-purity trifluorostyrene product. In addition, the purification process of the present application has low operating energy consumption and low production cost, can be purified efficiently and quickly, the high-purity trifluorostyrene product yield is extremely high, the process safety is high, and it can be produced continuously. The prepared high-purity trifluorostyrene product can perfectly meet the requirements for monomer raw material purity and performance in the field of electronic grade, battery grade or optical grade polymer synthesis.

[0062] The preferred embodiments of the present invention are described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0063] Example

[0064] In the following examples and comparative examples, a trifluorostyrene product produced by the applicant San Ai Fu Company's trifluorostyrene production line is used as a low-purity trifluorostyrene raw material. The production line adopts the technology described in patent application CN202111452390.2, and the purity of the low-purity trifluorostyrene is 99.05% by weight.

[0065] Tris(2,4-di-tert-butylphenyl)phosphite, pentaerythritol tetrakis{β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and octadecylβ-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate used in the examples were purchased from Sigma-Aldrich Co., Ltd.

[0066] The purification operations in all the following experiments were carried out in a distillation tower provided by Shanghai Research Institute of Chemical Industry Co., Ltd. The tower had a diameter of 200 mm and a height of 15,000 mm. The packing was monolithic packing, the number of theoretical plates was 45, and the material was continuously fed from the 8th theoretical plate. The tower pressure and flow control were centrally controlled by the automatic control instrument DCS.

[0067] The contents of various aromatic organic compounds in low-purity trifluorostyrene and high-purity trifluorostyrene before and after purification were tested using a Waters 1525 liquid chromatography (HPLC) manufactured by Waters Corporation of the United States. The purity of trifluorostyrene before and after purification and the yield of trifluorostyrene after purification were calculated based on the contents of various aromatic organic compounds.

[0068] Example 1

[0069] 0.04 wt% (based on the weight of the low-purity trifluorostyrene as 100 wt%) of pentaerythritol tetrakis{β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) was added to the low-purity trifluorostyrene to form a mixed liquid. The mixed liquid was transferred to a distillation tower and subjected to distillation purification at a temperature of 45° C. and a pressure of 25 kPa (absolute pressure). The purity of the trifluorostyrene obtained by distillation was characterized. The purity and yield of the obtained trifluorostyrene are summarized in Table 1 below.

[0070] In addition, the distillation in this embodiment is carried out in a continuous manner, which can achieve high-throughput purification operations on an industrial scale.

[0071] Example 2

[0072] 0.06 wt% (based on the weight of the low-purity trifluorostyrene as 100 wt%) of octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added to the low-purity trifluorostyrene to form a mixed liquid. The mixed liquid was then transferred to a distillation tower and subjected to distillation purification at a temperature of 50° C. and a pressure of 28 kPa (absolute pressure). The purity of the trifluorostyrene obtained by distillation was characterized. The purity and yield of the obtained trifluorostyrene are summarized in Table 1 below.

[0073] In addition, the distillation in this embodiment is carried out in a continuous manner, which can achieve high-throughput purification operations on an industrial scale.

[0074] Example 3

[0075] 0.04 wt% (based on the weight of the low-purity trifluorostyrene as 100 wt%) of pentaerythritol tetrakis{β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) and 0.01 wt% of tris(2,4-di-tert-butylphenyl)phosphite were added to the low-purity trifluorostyrene to form a mixed liquid. The mixed liquid was transferred to a distillation tower and subjected to distillation purification at a temperature of 48° C. and a pressure of 27 kPa (absolute pressure). The purity of the trifluorostyrene obtained by distillation was characterized. The purity and yield of the obtained trifluorostyrene are summarized in Table 1 below.

[0076] In addition, the distillation in this embodiment is carried out in a continuous manner, which can achieve high-throughput purification operations on an industrial scale.

[0077] Comparative Example 1

[0078] The low-purity trifluorostyrene was directly transferred into a distillation tower and subjected to distillation purification at a temperature of 45° C. and a pressure of 25 kPa (absolute pressure). The purity of the trifluorostyrene obtained by distillation purification was characterized. The purity and yield of the obtained trifluorostyrene are summarized in Table 1 below.

[0079] Comparative Example 2

[0080] 0.04 wt % (based on 100 wt % of the weight of the low-purity trifluorostyrene) of propyl gallate was added to the low-purity trifluorostyrene to form a mixed solution. The mixed solution was then transferred to a distillation tower and subjected to distillation purification at a temperature of 45° C. and a pressure of 25 kPa (absolute pressure). The purity of the trifluorostyrene obtained by distillation was characterized. The purity and yield of the obtained trifluorostyrene are summarized in Table 1 below.

[0081] Table 1: Product yield and product purity results of Examples 1-3 and Comparative Examples 1-2

[0082] Comparison of the experimental results of Examples 1-3 and Comparative Examples 1-2 above demonstrates that the present invention, by utilizing the first additive or a combination of the first and second additives specified in the present invention during distillation, enables significant improvements in product yield and purity in a high-throughput continuous process, yielding high-purity trifluorostyrene required for specific applications. In contrast, when no additive is used (Comparative Example 1) or when an additive other than that specified in the present invention is used (Comparative Example 2), both product yield and purity deteriorate significantly.

Claims

1. A purification method for preparing high-purity trifluorostyrene, the method comprising the following steps: Step (A): providing low-purity trifluorostyrene; Step (B): adding a first additive and an optional second additive to the low-purity trifluorostyrene to form a mixture; as well as Step (C) distilling the mixture to obtain the high-purity trifluorostyrene; The purity of the low-purity trifluorostyrene is less than 99.50% by weight, and the purity of the high-purity trifluorostyrene is ≥ 99.70% by weight; The first additive is a compound comprising at least one structure shown in Formula I: Where R 1 C3-C 16 Branched alkyl, R 2 A group selected from the following: covalent bond, C1-C 16 Straight chain alkyl, C3-C 16 Branched alkyl, C1-C 16 Straight chain alkylene, R 3 A group selected from the following: a covalent bond, a hydrogen atom, a C1-C 16 Straight chain alkyl, C3-C 16 Branched alkyl, C1-C 16 Straight chain alkylene, C3-C 16 Branched alkylene, C1-C 16 Straight chain alkylene acyl, C3-C 16 Branched chain alkylene acyl, C1-C 16 Straight chain alkylene acyloxy, C3-C 16 Branched alkylene acyloxy, Optionally, the first additive comprises a remaining portion other than at least one structure represented by Formula I, and the at least one structure represented by Formula I is connected via R 2 or R 3 connected to the remaining portion; The second additive is selected from the group consisting of: phosphoric acid, phosphate esters, phosphorous acid, and phosphite esters.

2. The purification method according to claim 1, characterized in that The first additive comprises one, two, three or four structures shown in formula I, and the remaining part of the first additive is selected from at least one of the following: C(CH2O-)4, C(CH2-)4, -O-CH(CH2O-)2, -CH(CH2-)2, (C1-C22) alkyl, (C1-C22) alkoxy, (C1-C22) alkylene, -O-(C1-C22) alkylene-O-, -NH-(C1-C22) alkylene-NH-, -NH-NH-, -NH2, -N(C1-C16 alkyl)2, -C(C1-C16 alkyl)2-, -(C1-C22) alkylene-C(C1-C16 alkyl)2-(C1-C22) alkylene, -(C1-C22) alkylene-C3-C16 heterocycloalkylene-(C1-C22) Alkylene-, -(C1-C22)alkylene-C(C1-C16alkyl)2-C3-C16heterocycloalkylene-C(C1-C16alkyl)2-(C1-C22)alkylene-, -(C1-C22)alkylene-C6-C16arylene-(C1-C22)alkylene-, -(C1-C22)alkylene-C(C1-C16alkyl)2-C6-C16arylene- C(C1-C16 alkyl)2-(C1-C22)alkylene-, -(C1-C22)alkylene-C6-C16heteroarylene-(C1-C22)alkylene-, -(C1-C22)alkylene-C(C1-C16 alkyl)2-C6-C16heteroarylene-C(C1-C16 alkyl)2-(C1-C22)alkylene-, -O-(C2-C12 alkylene-O) n -、-O-(C2-C12 alkylene-O) n -H, -C(C1-C16 alkyl)[C(O)O-(C2-C12 alkylene-O) n -H]-, Wherein n is an integer from 1 to 12.

3. The purification method according to claim 1, characterized in that The first additive includes at least one of the following: tetrakis{β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate}pentaerythritol, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl, 1,3,5-trimethyl-2,4,6(3,5-tert-butyl-4-hydroxybenzyl)benzene, 2,6-di-tert-butyl-4-methyl-phenol, 3,9-bis[2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)-propionyloxy]-1,1-dimethylethyl]- 2,4,8,10-tetraoxaspiro[5.5]undecane, 2,2'-methylenebis(4-methyl-6-tert-butyl-phenol), N,N'-1,6-hexylene-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine, bis[3-(1,1-dimethylethyl)-4-hydroxy-5-methylphenylpropionic acid]triethylene glycol.

4. The purification method according to claim 1, characterized in that The second additive is selected from at least one of the following: phosphoric acid, tri(C1-C16 alkyl) phosphate, tri(C6-C16 aromatic) phosphate, tetra(C6-C32 aromatic) bisphosphite, tri(C6-C22 aromatic) phosphite, di(C6-C22 aromatic) pentaerythritol bisdiphosphite, and di(C1-C22 alkyl) pentaerythritol bisdiphosphite.

5. The purification method according to claim 1, characterized in that The second additive is selected from at least one of the following: phosphoric acid, triphenyl phosphate, trimethyl phosphate, trioctyl phosphate, tridecyl phosphate, tri(dodecanol) phosphate, tri(hexadecanol) phosphate, triphenyl phosphite, trimethyl phosphite, trioctyl phosphite, tridecyl phosphite, tri(dodecanol) phosphite, tri(hexadecanol) phosphite, tri(2,4-di-tert-butylphenyl) phosphite, tetra(2,4-di-tert-butylphenyl-4,4'-tetrakis)phosphite. -biphenyl) bisphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol bisphosphite, bis(2,6-di-tert-butyl-4-tolyl)pentaerythritol bisphosphite, bis(octadecyl)pentaerythritol diphosphite, bis(2,4-dicumylphenyl)pentaerythritol bisphosphite, 2,2'-ethylenebis(4,6-di-tert-butylphenyl)fluorophosphite, 2,4,6-tri-tert-butylphenylpentaerythritol bisphosphite.

6. The purification method according to any one of claims 1 to 5, characterized in that Based on 100 parts by mass of the first additive, the amount of the second additive is 0 to 150 parts by mass.

7. The purification method according to any one of claims 1 to 5, characterized in that Based on 100 parts by mass of the total mass of the low-purity trifluorostyrene, the total amount of the first additive and the second additive is 0.01 to 0.15 parts by mass.

8. The purification method according to any one of claims 1 to 5, characterized in that Based on 100 parts by mass of the first additive, the amount of the second additive is 10 to 70 parts by mass; and Based on 100 parts by mass of the total mass of the low-purity trifluorostyrene, the total amount of the first additive and the second additive is 0.04 to 0.06 parts by mass.

9. The purification method according to any one of claims 1 to 5, characterized in that The method is carried out continuously in a distillation tower, the temperature in the distillation tower is 10-90°C, the pressure is 0-200 kPa, and the number of plates is 10-50.

10. High-purity trifluorostyrene, which is prepared by the method according to any one of claims 1 to 9, wherein the purity of the high-purity trifluorostyrene is ≥ 99.70% by weight.

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