Preparation method of a photoinitiator FMT

Abstract

The application belongs to the technical field of photoinitiator preparation, and particularly relates to a preparation method of a photoinitiator FMT, which comprises the following steps: reacting a compound of formula I-1 with an organic metal lithium to obtain a compound of formula I-2; reacting the compound of formula I-2 with titanium tetrachloride to obtain a compound of formula I-3; reacting cyclopentadiene with sodium amide to obtain sodium cyclopentadiene; and reacting the compound of formula I-3 with sodium cyclopentadiene to obtain the photoinitiator FMT shown in formula I. The yield of the photoinitiator FMT product prepared by the preparation method can reach 90% to 95%, the product purity is greater than 99.5%, the solvents used can be recycled and reused, cost is saved, and industrial waste liquid is avoided.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of photoinitiator preparation, and particularly relates to a preparation method of a photoinitiator FMT. BACKGROUND

[0002] The photoinitiator is a substance capable of absorbing radiation energy, undergoing photochemical change after excitation, and generating active intermediates (free radicals or cations) with the ability to initiate polymerization, and is a key component of photo-curing materials, and plays a decisive role in the photo-curing speed of photo-curing materials.

[0003] The photoinitiator FMT (chemical name: bis 2,6-difluoro-3-pyrrole phenyl titanium dichloride, chemical formula C 30 H 22 F4N2Ti, molecular weight 534) is a high-end photoinitiator product. The photoinitiator FMT has very high photosensitivity and photoinitiating activity, and has the characteristics of fast curing speed, no need for heating, less use of solvents, automatic operation in the curing process, and no migration after photo-curing, and is widely used in high-end UV resin and UV ink industries.

[0004] At present, there are mainly three kinds of production processes of the photoinitiator FMT disclosed at home and abroad, which are reported by the Swiss Ciba Specialty Chemicals Corporation, Hubei Guren Technology Co., Ltd. (Chinese patent application number: 201110221168.1) and Jingmen Yukuai Chemical Industry Co., Ltd. (Chinese patent application number: 200910223949.7). The preparation methods used in these processes are basically the same, and the synthesis route is as follows: 2,4-difluorophenyl pyrrole reacts with dichlorotitanocene under the catalysis of lithium salt to obtain the product photoinitiator FMT, and the preparation method is single.

[0005] SUMMARY

[0006] In view of the single preparation technology of the existing photoinitiator FMT, the application provides a brand-new preparation method of the photoinitiator FMT, and the yield and purity of the prepared photoinitiator FMT are high.

[0007] Specifically, the application provides the following technical scheme:

[0008] A preparation method of a photoinitiator FMT, and the synthesis route is as follows:

[0009]

[0010] The method comprises the following steps:

[0011] The compound of formula I-1 is reacted with an organic metal lithium to obtain a compound of formula I-2;

[0012] The compound of formula I-2 reacts with titanium tetrachloride to obtain the compound of formula I-3;

[0013] Cyclopentadiene reacts with sodium amide to obtain sodium cyclopentadienide;

[0014] The compound of formula I-3 reacts with sodium cyclopentadienide to obtain the photoinitiator FMT shown in formula I.

[0015] As preferred, the steps specifically include the following steps:

[0016] (1) Under the protection of inert gas, the compound of formula I-1 and the organic solvent A are added into the reaction kettle F1 and mixed uniformly;

[0017] The organic solvent A is selected from one or more of benzene, toluene, xylene and tetrahydrofuran;

[0018] (2) The temperature of the reaction kettle F1 is kept at -50℃ to -20℃, and the organometallic lithium is slowly added dropwise into the reaction kettle F1, after the dropwise addition is completed, the reaction is continued for a period of time to obtain a solution containing the compound of formula I-2;

[0019] (3) The temperature of the reaction kettle F1 is kept at -50℃ to -20℃, and the titanium tetrachloride is slowly added dropwise into the reaction kettle F1, after the dropwise addition is completed, the reaction is continued for a period of time to obtain a solution containing the compound of formula I-3;

[0020] (4) The temperature of the reaction kettle F2 is kept at -10℃ to 10℃, and under the protection of inert gas, tetrahydrofuran and sodium amide are added into the reaction kettle F2 and mixed uniformly, then cyclopentadiene is added dropwise, after the dropwise addition is completed, the reaction is continued for a period of time to obtain a tetrahydrofuran solution of sodium cyclopentadienide;

[0021] (5) The temperature of the reaction kettle F1 is kept at -40℃ to -10℃, the tetrahydrofuran solution of sodium cyclopentadienide is added into the reaction kettle F1, and the solution containing the compound of formula I-3 is reacted for a period of time to obtain a reaction solution containing the photoinitiator FMT shown in formula I.

[0022] As preferred, in steps (1) and (4), the inert gas is argon or nitrogen.

[0023] As preferred, in step (1), the water content in the solution after the compound of formula I-1 and the organic solvent A are mixed uniformly is less than 300ppm. The present application has certain requirements for the water content of the raw materials, if the water content exceeds 300ppm, there is a risk of deterioration of the raw materials and products.

[0024] As preferred, in step (1), the volume ratio of the compound of formula I-1 and the organic solvent A is 1:1 to 10.

[0025] As preferred, in step (2), the organic metal lithium is selected from one or more of lithium diethylamide, butyl lithium, lithium diisopropylamide and benzyl lithium;

[0026] The molar ratio of the organic metal lithium to the compound of formula I-1 is 1:1-1.5.

[0027] As preferred, in step (2), after the dropwise addition is completed, the reaction is continued for 4-7 hours.

[0028] As preferred, in step (3), the molar ratio of the titanium tetrachloride to the compound of formula I-1 is 1:2-2.5.

[0029] As preferred, in step (3), after the dropwise addition is completed, the reaction is continued for 6-10 hours.

[0030] As preferred, in step (4), the volume ratio of the tetrahydrofuran to the cyclopentadiene is 1-10:1.

[0031] The molar ratio of the sodium amide to the cyclopentadiene is 2-6:1.

[0032] As preferred, in step (4), after the dropwise addition is completed, the reaction is continued for 4-7 hours.

[0033] As preferred, in step (5), the molar ratio of the sodium cyclopentadiene to the compound of formula I-3 is 1-4:1.

[0034] As preferred, in step (5), the reaction time is 4-7 hours.

[0035] As preferred, the following steps are further included:

[0036] (6) The temperature of the reaction kettle F1 is maintained at 100-120℃, and the organic solvent A and tetrahydrofuran are removed to obtain a crude photoinitiator FMT;

[0037] (7) The temperature of the reaction kettle F1 is maintained at 0-10℃, deionized water is added to the reaction kettle F1, mixed with the crude photoinitiator FMT, stirred for a period of time, filtered to obtain a solid wet material;

[0038] (8) The solid wet material is vacuum dried to obtain a finished product of the photoinitiator FMT.

[0039] As preferred, in step (7), the volume ratio of the deionized water to the crude photoinitiator FMT is 1-5:1.

[0040] In the present application, the entire reaction process is carried out under anhydrous and anaerobic conditions.

[0041] The present application has the following beneficial effects:

[0042] (1) The application provides a preparation method of a photoinitiator FMT, a brand-new synthesis route is developed, 2,4-difluorophenyl pyrrole is reacted with titanium tetrachloride under the catalysis of an organic metal lithium compound, then sodium cyclopentadiene is reacted, and finally the photoinitiator FMT is obtained;

[0043] (2) The application provides a preparation method of a photoinitiator FMT, raw materials are all industrial products, are cheap and easy to obtain, and are commercially available;

[0044] (3) The application provides a preparation method of a photoinitiator FMT, all solvents used can be recycled and reused, cost is saved, and industrial waste liquid is avoided;

[0045] (4) The application provides a purification method of a crude photoinitiator FMT, a product yield of the prepared photoinitiator FMT can reach 90% to 95%, and the product purity is greater than 99.5%. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical scheme and advantages of the embodiments of the application more clear, the technical scheme in the embodiments of the application is clearly and completely described below, and the following embodiments are used to illustrate the application, but not to limit the scope of the application. If the specific technology or condition is not specified in the embodiments, the technology or condition is carried out according to the technology or condition described in the literature in the field or according to the product instruction.

[0047] In the following embodiments, the compound 2,4-difluorophenyl pyrrole of formula I-1 is obtained from Jiangsu Duxing Zhijun New Material Technology Co., Ltd.

[0048] Embodiment 1

[0049] A preparation method of a photoinitiator FMT, steps are as follows:

[0050] (1) After the reaction kettle F1 is replaced with high-purity nitrogen for three times, tetrahydrofuran 100.00Kg and 2,4-difluorophenyl pyrrole 20.00Kg are sequentially added into the kettle under the protection of inert gas, and after being uniformly stirred, the solution is sampled and measured to be less than 100ppm in water content.

[0051] (2) The reaction kettle F1 is cooled to-30℃, and diethylaminolithium 8.82Kg is slowly added dropwise, and after the dropwise addition is completed, the reaction is carried out for 6 hours under the condition of-30℃.

[0052] (3) The reaction kettle F1 is kept at-30℃, and titanium tetrachloride 10.60Kg is slowly added dropwise, and after the dropwise addition is completed, the reaction is carried out for 8 hours under the condition of-30℃, to obtain a solution of a photoinitiator FMT intermediate.

[0053] (4) After the reactor F2 is replaced with inert gas for 3 times, the temperature of the reactor is kept at 0°C, and then 60 Kg of solvent tetrahydrofuran and 13.07 Kg of sodium amide are sequentially added into the reactor, and after being stirred uniformly, 7.37 Kg of cyclopentadiene is added dropwise. After the dropwise addition is completed, the reaction is carried out for 5 hours to obtain a purple sodium cyclopentadiene tetrahydrofuran solution.

[0054] (5) The temperature of the reactor F1 is kept at -20°C, and then the purple sodium cyclopentadiene tetrahydrofuran solution obtained in step (4) is added into the solution of the photoinitiator FMT intermediate in the reactor F1. After the addition is completed, the reaction is carried out for 5 hours to obtain a photoinitiator FMT reaction solution.

[0055] (6) The temperature of the reactor F1 is increased to 100°C to distill and concentrate the tetrahydrofuran to obtain a crude photoinitiator FMT.

[0056] (7) The temperature of the reactor F1 is decreased to 0°C, and then 100 Kg of pure water is added into the crude photoinitiator FMT, and the stirring is carried out for 3 hours. Then the obtained solution is filtered through a filter to obtain a solid wet material.

[0057] (8) The solid wet material is placed in a vacuum dryer, and the vacuum degree is -0.09-0.095 MPa, and then the temperature is increased to 90-95°C to carry out vacuum drying to obtain a photoinitiator FMT product.

[0058] The entire reaction is carried out under anhydrous and anaerobic conditions.

[0059] The yield of the photoinitiator FMT product obtained in Example 1 is 94%, and the purity of the product is 99.6%. Among them, the yield of the FMT product = FMT actual yield / FMT theoretical yield * 100%, and the detection method of the purity of the FMT product refers to the standard “Photoinitiator FMT” (standard code: Q / 718J 122-2024)

[0060] Although the present application has been described in detail in the foregoing general description, specific embodiments and experiments, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present application. Therefore, these modifications or improvements made on the basis of not deviating from the spirit of the present application, all belong to the scope of protection claimed by the present application.

Claims

1. A method for preparing a photoinitiator FMT, characterized in that, The synthesis route is as follows: Specifically, the following steps are included: (1) Under the protection of an inert gas, add compound of formula I-1 and organic solvent A to reactor F1 and mix them evenly; The organic solvent A is selected from one or more of benzene, toluene, xylene, and tetrahydrofuran; (2) Keep the temperature of the reactor F1 at -50℃ to -20℃, slowly add organometallic lithium to the reactor F1, and continue the reaction for a period of time after the addition is completed to obtain a solution containing compound I-2; (3) Keep the temperature of the reactor F1 at -50℃ to -20℃, slowly add titanium tetrachloride dropwise to the reactor F1, and continue the reaction for a period of time after the addition is completed to obtain a solution containing compound I-3; (4) Keep the temperature of reactor F2 at -10℃~10℃. Under the protection of inert gas, add tetrahydrofuran and sodium amino to reactor F2 and mix them evenly. Then add cyclopentadiene dropwise. After the dropwise addition is completed, continue the reaction for a period of time to obtain a tetrahydrofuran solution of sodium cyclopentadiene. (5) Keep the temperature of the reactor F1 at -40℃ to -10℃, add the tetrahydrofuran solution of sodium cyclopentadiene to the reactor F1, and react with the solution containing the compound of formula I-3 for a period of time to obtain a reaction solution containing the photoinitiator FMT shown in formula I.

2. The method for preparing the photoinitiator FMT according to claim 1, characterized in that, In step (1), the water content in the solution after the compound of formula I-1 and organic solvent A are mixed evenly is less than 300 ppm; And / or, the volume ratio of the compound of formula I-1 to organic solvent A is 1:1 to 10.

3. The method for preparing the photoinitiator FMT according to claim 1 or 2, characterized in that, In step (2), the organometallic lithium is selected from one or more of lithium diethylamino, butyllithium, lithium diisopropylamino, and benzyllithium; The molar ratio of the organometallic lithium to the compound of formula I-1 is 1:1 to 1.

5.

4. The method for preparing the photoinitiator FMT according to claim 1 or 2, characterized in that, In step (3), the molar ratio of titanium tetrachloride to the compound of formula I-1 is 1:2 to 2.

5.

5. The method for preparing the photoinitiator FMT according to claim 1 or 2, characterized in that, In step (4), the volume ratio of tetrahydrofuran to cyclopentadiene is 1 to 10:1; The molar ratio of sodium amino group to cyclopentadiene is 2-6:

1.

6. The method for preparing the photoinitiator FMT according to claim 1 or 2, characterized in that, In step (5), the molar ratio of sodium cyclopentadiene to compound I-3 is 1 to 4:

1.

7. The method for preparing the photoinitiator FMT according to claim 1 or 2, characterized in that, It also includes the following steps: (6) Keep the temperature of the reactor F1 at 100℃~120℃, remove organic solvent A and tetrahydrofuran, and obtain crude photoinitiator FMT; (7) Keep the temperature of the reactor F1 at 0℃~10℃, add deionized water to the reactor F1, mix with crude photoinitiator FMT, stir for a period of time, filter, and obtain solid wet material; (8) The solid wet material is vacuum dried to obtain the photoinitiator FMT finished product.

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