Purification method of photoinitiator FMT crude product

Abstract

The invention belongs to the technical field of fine chemical engineering, and particularly relates to a purification method of a photoinitiator FMT crude product, which comprises the following steps: S1, adding a ketone solvent and the photoinitiator FMT crude product into a stirring kettle, and stirring for a period of time; s2, conveying the stirred material to an adsorption tower filled with an adsorption filler for adsorption; and S3, conveying the adsorbed material to a distillation tower for distillation, and drying the material discharged from the tower kettle to obtain the photoinitiator FMT. According to the purification method, various impurities in the FMT crude product can be effectively removed, the purity of the FMT refined product reaches 99.8% or above, and the purification method is simple in process, low in energy consumption, low in cost and suitable for industrial production.

Description

Technical Field

[0001] The invention belongs to the technical field of fine chemicals, and in particular relates to a method for purifying a crude photoinitiator FMT. Background Art

[0002] Photoinitiators, also known as photosensitizers and photocuring agents, are compounds that can absorb energy of a certain wavelength in the ultraviolet region (250-420nm) or visible region (400-800nm) to generate free radicals, cations, etc., thereby initiating monomer polymerization, cross-linking and curing. They are mainly used in UV curing, laser imaging, holography, photoresist and other fields. FMT (bis-2,6-difluoro-3-pyrrophenyl titanocene) is a type of photoinitiator, and its molecular structure is shown in formula (1):

[0003]

[0004] Photoinitiator FMT can be used as an active diluent, mainly together with mono- or multi-functional vinyl monomers and oligomers for UV and visible light curing of unsaturated prepolymers. Its photoinitiation process is that after absorbing light energy, it is photoisomerized into a ring-based photoreaction intermediate, which undergoes ligand replacement with the ester carbonyl of acrylate in the oligomer and active diluent to generate free radicals, initiating polymerization and crosslinking.

[0005] FMT has many significant advantages. First, it exhibits multiple strong absorption peaks in the wavelength range of 330-560nm, covering an ultra-wide ultraviolet and visible light absorption band, so it can efficiently utilize a variety of light sources, and can effectively initiate curing under ultraviolet light, visible light and even suitable laser irradiation, showing high photosensitivity and photosensitivity. In addition, FMT is particularly suitable for dark photocurable coatings, and can effectively cure coatings with a thickness of 70μm and above, thanks to its good absorption capacity in the visible light region and the bleaching effect after photolysis. FMT also has excellent thermal stability, with a thermal decomposition temperature of up to 230°C, and can remain stable even when boiled in acetic acid or sodium hydroxide solution for several hours. More importantly, the product after FMT photolysis is complexed with acrylate and will not migrate to the surface, ensuring its safety, environmental protection and hygiene. Based on these comprehensive advantages, FMT is widely used in high-tech and high-value-added fields such as imaging or information storage, such as argon ion laser scanning curing, laser direct imaging, photoresist preparation, holography, and stereolithography.

[0006] At present, the conventional production process of the photoinitiator FMT in the art is to prepare it by reacting 2,4-difluorophenylpyrrole and dichlorotitanocene in an organic solvent with a strong base for catalysis.

[0007] For example, CN101712696A discloses a method for producing a photoinitiator FMT, which specifically comprises reacting 2,5-dimethoxytetrahydrofuran with 2,4-difluoroaniline in a low-temperature reactor to generate 2,4-difluorophenylpyrrole, and then directly adding dichlorotantalum and a solvent into the low-temperature reactor to dechlorinate the photoinitiator FMT under the catalysis of an organic strong base, wherein the organic strong base is sodium diisopropylamide, lithium diisopropylamide, sodium diethylamide or lithium diethylamide, and the solvent is toluene or tetrahydrofuran.

[0008] CN102584904A discloses a production method of a photoinitiator FMT, which specifically comprises the following steps: adding xylene and 2,5-dimethoxytetrahydrofuran into a reaction kettle with an inert atmosphere, cooling the temperature to -4 to -5°C, slowly dripping 2,4-difluoroaniline, heating the temperature to 50 to 60°C and keeping the temperature for 5 to 10 hours; adding xylene, heating the temperature to 140 to 145°C for distillation; adding titanocene dichloride, cooling the temperature to -10 to -40°C, dripping a catalyst organic strong base amino lithium salt, and reacting at -10 to -40°C to synthesize a photoinitiator FMT reaction solution; heating the temperature to 15 to 30°C, chromatography; keeping the temperature for crystallization; chromatography, washing with xylene, and draining to obtain a wet product; and vacuum drying.

[0009] However, the above two production methods are complicated, costly, and low in purity (70%-95%), and the crude products obtained often contain more lithium salts, titanium-based polymers, copolymers, and organic solvents, which not only limits their wide application in the field of high-end chips (such as photoresists, etc.), but also these impurities will cause the final product to be unstable, and long-term storage will cause purple, black, and deterioration, which greatly affects the quality of the product.

[0010] Therefore, purifying FMT to obtain products with higher purity has huge economic and social benefits. Summary of the invention

[0011] The purpose of the present invention is to provide a method for purifying a crude photoinitiator FMT, which can effectively solve the technical problems existing in the current photoinitiator FMT production method, such as complex process, high cost, low purity, and impurities in the crude product limiting the application of FMT in the field of high-end chips and affecting product stability and quality.

[0012] Specifically, the present invention provides the following technical solutions:

[0013] A method for purifying a crude photoinitiator FMT comprises the following steps:

[0014] S1, adding ketone solvent and photoinitiator FMT crude product into a stirred tank, stirring for a period of time;

[0015] S2, transporting the stirred material to an adsorption tower equipped with adsorption filler for adsorption;

[0016] S3, conveying the adsorbed material to a distillation tower for distillation, and drying the material discharged from the bottom of the tower to obtain the photoinitiator FMT.

[0017] In the present invention, the crude photoinitiator FMT refers to a crude product obtained by subjecting 2,4-difluorophenylpyrrole and dichlorotitacenes to a strong base-catalyzed reaction in an organic solvent and then removing the organic solvent.

[0018] Preferably, in step S1, the ketone solvent is selected from at least one of acetone, butanone, methyl ethyl ketone, cyclohexanone, and methyl isobutyl ketone;

[0019] The feed mass ratio of the crude photoinitiator FMT to the ketone solvent is 2.5 to 4.5: 1. Compared with other organic solvents, the ketone solvent can better dissolve the crude product and is more conducive to the adsorption of impurities in the adsorbent.

[0020] Preferably, in step S1, the stirring time is 0.5-2h. Studies have shown that if the stirring time is shorter than the above, the crude product may not be completely dissolved and dispersed in the solvent.

[0021] Preferably, in step S2, the method for preparing the adsorption filler comprises the following steps:

[0022] (1) 30-50 parts of activated diatomite, 20-30 parts of pseudo-boehmite and 150-200 parts of water are mixed, stirred evenly, and then 1-5 parts of a mixture of tetrapropylammonium bromide and cyclohexylamine are added, and then added to a hydrothermal synthesis reactor, heated to 155-190° C., and kept warm for 10-14 hours to obtain a reaction solution;

[0023] (2) allowing the reaction solution to stand, pouring out the upper clear liquid, taking out the lower slurry, heating it to 300-400° C., and keeping it warm for 5-7 hours to obtain a dry powder;

[0024] (3) Add 5 to 10 parts of dilute nitric acid to the dry powder, and place the resulting mixture into a molding device for molding. The study found that the adsorption filler prepared by the above method has a high efficiency in removing lithium salts, titanium-based polymers, and copolymers in the crude initiator FMT, and basically does not cause the loss of the initiator FMT.

[0025] Preferably, in step S2, the temperature of the adsorption tower is -10 to 0° C. Studies have shown that when the temperature of the adsorption tower is greater than 0° C., the adsorption effect on impurities is significantly reduced.

[0026] Preferably, in step S3, the bottom temperature of the distillation tower is 50-85°C, the top temperature is -10-0°C, the top condensate is refluxed, and the reflux ratio is 2-5:1.

[0027] Preferably, in step S3, the distillation tower is a plate distillation tower with 8 to 12 plates, a reboiler is provided in the bottom of the tower, and a condenser is provided at the top of the tower.

[0028] Preferably, in step S3, the drying is vacuum drying at 55-75° C., and the drying time is 12-20 hours.

[0029] Preferably, in step S3, the ketone solvent discharged from the top of the distillation tower is directly refluxed into the ketone solvent storage container for recycling.

[0030] The beneficial effects achieved by the present invention are:

[0031] (1) The present invention provides a method for purifying a crude photoinitiator FMT, which can efficiently remove various impurities such as lithium salts, titanium-based polymers, copolymers and organic solvents in the crude photoinitiator FMT by adopting specific adsorption fillers, purification steps and parameter control, and significantly improve the purity of the product. The purity of the final FMT product can reach more than 99.8%;

[0032] (2) The method for purifying a crude photoinitiator FMT provided by the present invention has the significant advantages of simple process, low energy consumption and low cost. Compared with the traditional complex production process, the present invention reduces the production steps and energy consumption, reduces the production cost, and makes the purification process of FMT more economical and efficient;

[0033] (3) In the method for purifying a crude photoinitiator FMT provided by the present invention, the temperature of the adsorption tower is preferably -10 to 0°C. Studies have shown that when the temperature of the adsorption tower is greater than 0°C, the adsorption effect on impurities is significantly reduced;

[0034] (4) The present invention provides a method for purifying a crude photoinitiator FMT. The purification device used is reasonably designed, easy to operate and maintain, and is very suitable for industrial production, providing strong technical support for the widespread application of FMT. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Schematic diagram of the purification device used in the embodiment; wherein: 1. stirred tank; 2. adsorption tower; 3. distillation tower; 4. cold trap; 5. vacuum dryer.

[0036] Figure 2 This is the product test spectrum of the photoinitiator FMT in Example 1;

[0037] Figure 3This is the product test spectrum of the photoinitiator FMT in Example 2;

[0038] Figure 4 This is the product test spectrum of the photoinitiator FMT in Example 3; DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention. If no specific technology or conditions are specified in the embodiments, the technology or conditions described in the literature in the field or the product manual shall be followed.

[0040] In the following examples, the purification device used is as follows Figure 1 As shown, it includes a stirring kettle 1, an adsorption tower 2, a distillation tower 3, a cold trap 4, and a vacuum dryer 5;

[0041] The lower outlet of the stirring kettle 1 is connected to the lower inlet of the adsorption tower 2, the upper outlet of the adsorption tower 2 is connected to the lower part of the column of the distillation tower 3, the top outlet of the distillation tower 3 is connected to the top inlet of the cold trap 4, the bottom outlet of the cold trap 4 is connected to the upper inlet of the stirring kettle 1, and the lower outlet of the tower of the distillation tower 3 is connected to the inlet of the vacuum dryer 5. The tower of the distillation kettle 3 is provided with a reboiler, and the top of the tower is provided with a condenser.

[0042] In the following examples, the purity of the crude photoinitiator FMT used is 92.582%, and the preparation method is as follows: 1.45 parts by weight of 2,4-difluorophenylpyrrole, 1 part by weight of dichlorotantalum, and 5.4 parts by weight of tetrahydrofuran are added to a reaction kettle, and after the temperature is reduced to -100°C to -60°C, 2.16 parts by weight of lithium diethylamide are added, and the tetrahydrofuran solvent is removed by distillation after dechlorination to obtain a crude photoinitiator FMT.

[0043] In the following examples, the activated diatomaceous earth used was purchased from Jilin Yuantong Mining Co., Ltd., model: C40.

[0044] Example 1

[0045] A method for purifying a crude photoinitiator FMT comprises the following steps:

[0046] S1, put the acetone in the cold trap 4 into the stirring tank 1, add a certain amount of photoinitiator FMT crude product into the stirring tank 1, start stirring, and stir thoroughly for 1h;

[0047] S2, controlling the adsorption temperature of the adsorption tower 2, transporting the material in the stirred tank 1 to the adsorption tower 2, and entering the distillation tower 3 after adsorption;

[0048] S3, distilling the material in the distillation tower 3, collecting the acetone discharged from the top of the tower into the cold trap 4, and then entering the stirring tank 1 for reuse; the material discharged from the tower tank is transferred to the vacuum dryer 5 for drying to obtain the pure product of the photoinitiator FMT.

[0049] In this embodiment, the mass ratio of the crude photoinitiator FMT to acetone is 3.2:1.

[0050] In this embodiment, the adsorption temperature of the adsorption tower 2 is -10°C.

[0051] In this embodiment, the bottom temperature of the distillation tower 3 is 50° C., the bottom pressure is -0.075 MPa (relative pressure, the same below), the top temperature is -10° C., the top pressure is -0.080 MPa, and the reflux ratio is 2.5:1.

[0052] In this embodiment, the temperature of the vacuum dryer 5 is 55° C., the pressure is −0.095 MPa, and the vacuum drying time is 12 hours.

[0053] In this embodiment, the column of the distillation tower 3 is a plate tower, and the number of its plates is 8.

[0054] In this embodiment, the preparation method of the adsorption filler in the adsorption tower 2 is as follows: 30 parts of activated diatomite and 20 parts of pseudo-boehmite are mixed, 150 parts of water are added, and after stirring evenly, 1 part of a 1:1 mixture of tetrapropylammonium bromide and cyclohexylamine is added, and the mixed solution is placed in a hydrothermal synthesis kettle and heated at 180°C for 12 hours. After the heating is completed, the temperature is naturally lowered, the upper clear liquid is poured out, the lower slurry is taken out and placed in a crucible, and baked at 350°C for 6 hours. After baking, the dry powder is taken out, 5 parts of a 5% dilute nitric acid aqueous solution are added, until the dry powder is formed, and then placed in a molding device, extruded and heated into a regular honeycomb filler shape with a pore size of 3-8mm.

[0055] Depend on Figure 2 It can be seen that the purity of the final photoinitiator FMT product obtained in this example is 99.286%.

[0056] The test conditions are:

[0057] Detector: UVD;

[0058] Chromatographic column: C18 column

[0059] Detection wavelength: 280nm;

[0060] Column oven temperature: 27°C

[0061] Mobile phase: methanol: water = 9:1;

[0062] Mobile phase flow rate: 0.8ml / min.

[0063] Example 2

[0064] A method for purifying a crude photoinitiator FMT comprises the following steps:

[0065] S1, put butanone in cold trap 4 into stirring tank 1, add a certain amount of crude photoinitiator FMT into stirring tank 1, start stirring, and stir thoroughly for 1h;

[0066] S2, controlling the adsorption temperature of the adsorption tower 2, transporting the material in the stirred tank 1 to the adsorption tower 2, and entering the distillation tower 3 after adsorption;

[0067] S3, distilling the material in the distillation tower 3, collecting the butanone discharged from the top of the tower into the cold trap 4, and then entering the stirring tank 1 for reuse; the discharge from the tower tank is transferred to the vacuum dryer 5 and dried to obtain the pure photoinitiator FMT.

[0068] In this embodiment, the mass ratio of the crude photoinitiator FMT to butanone is 3.2:1.

[0069] In this embodiment, the adsorption temperature of the adsorption tower 2 is 0°C.

[0070] In this embodiment, the bottom temperature of the distillation tower 3 is 85° C., the bottom pressure is −0.075 MPa, the top temperature is 0° C., the top pressure is −0.080 MPa, and the reflux ratio is 2.5:1.

[0071] In this embodiment, the temperature of the vacuum dryer 5 is 75° C., the pressure is −0.095 MPa, and the vacuum drying time is 20 h.

[0072] In this embodiment, the column of the distillation tower 3 is a plate tower, and the number of its plates is 12.

[0073] In this embodiment, the preparation method of the adsorption filler in the adsorption tower 2 is as follows: 35 parts of activated diatomite and 26 parts of pseudo-boehmite are mixed, 173 parts of water are added, and after stirring evenly, 3 parts of a 1:1 mixture of tetrapropylammonium bromide and cyclohexylamine are added, and the mixed solution is placed in a hydrothermal synthesis kettle and heated at 180°C for 12 hours. After the heating is completed, the temperature is naturally lowered, the upper clear liquid is poured out, the lower slurry is taken out and placed in a crucible, and baked at 350°C for 6 hours. After baking, the dry powder is taken out, 6 parts of a 5% dilute nitric acid aqueous solution are added, until the dry powder is formed, and then placed in a molding device, extruded and heated into a regular honeycomb filler shape.

[0074] Depend on Figure 3 It can be seen that the purity of the final product obtained in this example is 99.403%.

[0075] The test conditions are:

[0076] Detector: UVD;

[0077] Chromatographic column: C18 column

[0078] Detection wavelength: 280nm;

[0079] Column oven temperature: 27°C

[0080] Mobile phase: methanol: water = 9:1;

[0081] Mobile phase flow rate: 0.8ml / min.

[0082] Example 3

[0083] A method for purifying a crude photoinitiator FMT comprises the following steps:

[0084] S1, put the methyl ethyl ketone in the cold trap 4 into the stirring tank 1, add a certain amount of photoinitiator FMT crude product into the stirring tank 1, start stirring, and stir thoroughly for 1h;

[0085] S2, controlling the adsorption temperature of the adsorption tower 2, transporting the material in the stirred tank 1 to the adsorption tower 2, and entering the distillation tower 3 after adsorption;

[0086] S3, distilling the material in the distillation tower 3, collecting the methyl ethyl ketone discharged from the top of the tower into the cold trap 4, and then entering the stirring tank 1 for reuse; the material discharged from the tower tank is transferred to the vacuum dryer 5 and dried to obtain the pure product of the photoinitiator FMT.

[0087] In this embodiment, the mass ratio of the crude photoinitiator FMT to methyl ethyl ketone is 3.2:1.

[0088] In this embodiment, the adsorption temperature of the adsorption tower 2 is -3°C.

[0089] In this embodiment, the bottom temperature of the distillation kettle 3 is 70° C., the bottom pressure is −0.075 MPa, the top temperature is −4° C., the top pressure is −0.080 MPa, and the reflux ratio is 2.5:1.

[0090] In this embodiment, the temperature of the vacuum dryer 5 is 62° C., the pressure is −0.095 MPa, and the vacuum drying time is 15 h.

[0091] In this embodiment, the column of the distillation tower 3 is a plate tower, and the number of its plates is 10.

[0092] In this embodiment, the preparation method of the adsorption filler in the adsorption tower 2 is as follows: 50 parts of activated diatomite and 30 parts of pseudo-boehmite are mixed, 200 parts of water are added, and after stirring evenly, 5 parts of a 1:1 mixture of tetrapropylammonium bromide and cyclohexylamine are added, and the mixed solution is placed in a hydrothermal synthesis kettle and heated at 180°C for 12 hours. After the heating is completed, the temperature is naturally lowered, the upper clear liquid is poured out, the lower slurry is taken out and placed in a crucible, and baked at 350°C for 6 hours. After baking, the dry powder is taken out, 10 parts of a 5% dilute nitric acid aqueous solution are added, until the dry powder is formed, and then placed in a molding device, extruded and heated into a regular honeycomb filler shape.

[0093] Depend on Figure 4 It can be seen that the purity of the final product obtained in this example is 99.110%.

[0094] The test conditions are:

[0095] Detector: UVD;

[0096] Chromatographic column: C18 column

[0097] Detection wavelength: 280nm;

[0098] Column oven temperature: 27°C

[0099] Mobile phase: methanol: water = 9:1;

[0100] Mobile phase flow rate: 0.8ml / min.

[0101] Although the present invention has been described in detail above by general description, specific implementation methods and experiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A method for purifying a crude photoinitiator FMT, characterized in that: The following steps are involved: S1, adding ketone solvent and photoinitiator FMT crude product into a stirred tank, stirring for a period of time; S2, transporting the stirred material to an adsorption tower equipped with adsorption filler for adsorption; S3, conveying the adsorbed material to a distillation tower for distillation, and drying the material discharged from the bottom of the tower to obtain the photoinitiator FMT.

2. The method for purifying a crude photoinitiator FMT according to claim 1, characterized in that: In step S1, the ketone solvent is selected from at least one of acetone, butanone, methyl ethyl ketone, cyclohexanone, and methyl isobutyl ketone; The feed mass ratio of the crude photoinitiator FMT to the ketone solvent is 3.2:

1.

3. The method for purifying a crude photoinitiator FMT according to claim 1 or 2, characterized in that: In step S1, the stirring time is 1 hour.

4. The method for purifying a crude photoinitiator FMT according to claim 1 or 2, characterized in that: In step S2, the method for preparing the adsorption filler comprises the following steps: (1) 30-50 parts of activated diatomite, 20-30 parts of pseudo-boehmite and 150-200 parts of water are mixed, stirred evenly, and then 1-5 parts of a mixture of tetrapropylammonium bromide and cyclohexylamine are added, and then added to a hydrothermal synthesis kettle, heated to 180° C., and kept warm for 12 hours to obtain a reaction solution; (2) The reaction solution was allowed to stand, the upper clear liquid was poured out, the lower slurry was taken out, and the mixture was heated to 350° C. and kept warm for 6 hours to obtain a dry powder; (3) Add 5-10 parts of dilute nitric acid to the dry powder, and place the resulting mixture into a molding device for molding.

5. The method for purifying a crude photoinitiator FMT according to claim 1 or 2, characterized in that: In step S2, the temperature of the adsorption tower is -10 to 0°C.

6. The method for purifying a crude photoinitiator FMT according to claim 1 or 2, characterized in that: In step S3, the bottom temperature of the distillation tower is 50-85°C, the top temperature is -10-0°C, the top condensate is refluxed, and the reflux ratio is 2.5:

1.

7. The method for purifying a crude photoinitiator FMT according to claim 1 or 2, characterized in that: In step S3, the distillation tower is a plate distillation tower with 8 to 12 plates, a reboiler is provided in the tower bottom, and a condenser is provided at the tower top.

8. The method for purifying a crude photoinitiator FMT according to claim 1 or 2, characterized in that: In step S3, the ketone solvent discharged from the top of the distillation tower is directly refluxed into the ketone solvent storage container for recycling.

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