Preparation method of photoinitiator FMT

Abstract

The invention belongs to the technical field of preparation of photoinitiators, and particularly relates to a preparation method of a photoinitiator FMT, which comprises the following steps: reacting a compound of formula I-1 with organic metal lithium to obtain a compound of formula I-2; reacting the compound as shown in the formula I-2 with titanium tetrachloride to obtain a compound as shown in a formula I-3; enabling the cyclopentadiene to react with sodium amide to obtain sodium cyclopentadiene; and reacting the compound as shown in the formula I-3 with sodium cyclopentadiene to obtain the photoinitiator FMT as shown in the formula I. The yield of the photoinitiator FMT product prepared by the preparation method can reach 90-95%, and the product purity is gt; all the used solvents can be recycled and reused, so that the cost is saved, and the generation of industrial waste liquid is avoided. # imgabs0 #

Description

Technical Field

[0001] The invention belongs to the technical field of photoinitiator preparation, and particularly relates to a method for preparing a photoinitiator FMT. Background Art

[0002] Photoinitiators are substances that can absorb radiation energy, undergo photochemical changes upon excitation, and produce active intermediates (free radicals or cations) with the ability to initiate polymerization. They are key components of photocurable materials and play a decisive role in the photocuring speed of photocurable materials.

[0003] Photoinitiator FMT (chemical name: bis(2,6-difluoro-3-pyrrophenyl)titanocene, chemical formula C 30 H 22 F4N2Ti, molecular weight 534) is a high-end photoinitiator product. Due to the high photosensitivity and photoinitiating activity of the photoinitiator FMT, as well as the characteristics of fast curing speed, no need for heating, less use of solvents, automatic curing process and no migration after light curing, it is widely used in high-end UV resin and UV ink industries.

[0004] At present, there are three main production processes of photoinitiator FMT that have been disclosed at home and abroad, which are reported by Swiss Ciba Specialty Chemicals, Hubei Gurun Technology Co., Ltd. (Chinese patent application number: 201110221168.1) and Jingmen Yukui Chemical Co., Ltd. (Chinese patent application number: 200910223949.7). The preparation methods used in these processes are basically the same. The synthetic routes are as follows: 2,4-difluorophenylpyrrole reacts with dichlorodipentadienyl titanocene under lithium salt catalysis to obtain the product photoinitiator FMT, and the preparation method is single.

[0005] Summary of the invention

[0006] In view of the problem that the existing preparation technology of photoinitiator FMT is single, the present invention provides a new preparation method of photoinitiator FMT, and the prepared photoinitiator FMT has high yield and high purity.

[0007] Specifically, the present invention provides the following technical solutions:

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

[0009]

[0010] The following steps are involved:

[0011] The compound of formula I-1 reacts with an organometallic lithium to obtain a compound of formula I-2;

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

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

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

[0015] As a preference, the method specifically comprises the following steps:

[0016] (1) Under the protection of inert gas, add the compound of formula I-1 and organic solvent A into the reaction kettle F1 and mix them evenly;

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

[0018] (2) maintaining the temperature of the reaction kettle F1 at -50°C to -20°C, slowly adding organometallic lithium to the reaction kettle F1, and after the addition is completed, continuing the reaction for a period of time to obtain a solution containing the compound of formula I-2;

[0019] (3) maintaining the temperature of the reaction kettle F1 at -50°C to -20°C, slowly adding titanium tetrachloride to the reaction kettle F1, and after the addition is completed, continuing the reaction for a period of time to obtain a solution containing the compound of formula I-3;

[0020] (4) keeping the temperature of the reaction kettle F2 at -10°C to 10°C, under the protection of inert gas, adding tetrahydrofuran and sodium amide to the reaction kettle F2 and mixing them evenly, then adding cyclopentadiene dropwise, and after the addition is completed, continuing the reaction for a period of time to obtain a tetrahydrofuran solution of sodium cyclopentadiene;

[0021] (5) The temperature of the reaction kettle F1 is maintained at -40°C to -10°C, and the tetrahydrofuran solution of sodium cyclopentadiene is added to the reaction kettle F1 to 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.

[0022] Preferably, in step (1) and step (4), the inert gas is argon or nitrogen.

[0023] Preferably, in step (1), the water content of the solution after the compound of formula I-1 and the organic solvent A are uniformly mixed is less than 300 ppm. The present invention has certain requirements on the water content of the raw materials. If the water content exceeds 300 ppm, the raw materials and products are at risk of deterioration.

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

[0025] Preferably, in step (2), the organometallic 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 to 1.5.

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

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

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

[0030] Preferably, in step (4), the volume ratio of tetrahydrofuran to cyclopentadiene is 1 to 10:1;

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

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

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

[0034] Preferably, in step (5), the reaction time is 4 to 7 hours.

[0035] As a preference, the method further comprises the following steps:

[0036] (6) maintaining the temperature of the reactor F1 at 100° C. to 120° C., removing the organic solvent A and tetrahydrofuran, and obtaining a crude photoinitiator FMT;

[0037] (7) maintaining the temperature of the reactor F1 at 0° C. to 10° C., adding deionized water to the reactor F1, mixing with the crude photoinitiator FMT, stirring for a period of time, filtering, and obtaining a solid wet material;

[0038] (8) vacuum drying the solid wet material to obtain a finished photoinitiator FMT product.

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

[0040] In the present invention, the entire reaction process is carried out under anhydrous and oxygen-free conditions.

[0041] Beneficial effects achieved by the present invention:

[0042] (1) The present invention provides a method for preparing a photoinitiator FMT, which develops a new synthesis route, using 2,4-difluorophenylpyrrole to react with titanium tetrachloride under the catalysis of an organic metal lithium compound, and then reacting with sodium cyclopentadiene to finally obtain the photoinitiator FMT;

[0043] (2) The present invention provides a method for preparing a photoinitiator FMT, wherein the raw materials are all industrial products, cheap, easily available, and commercially available;

[0044] (3) The present invention provides a method for preparing a photoinitiator FMT, in which the solvents used can be recovered and reused, thus saving costs and avoiding the generation of industrial waste liquid;

[0045] (4) The present invention provides a method for purifying a crude photoinitiator FMT, wherein the yield of the prepared photoinitiator FMT can reach 90% to 95%, and the product purity is >99.5%. DETAILED DESCRIPTION

[0046] 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 is described clearly and completely below. The following embodiments are used to illustrate the present invention, but are not used 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 instructions are used.

[0047] In the following examples, the compound 2,4-difluorophenylpyrrole of formula I-1 used is derived from Jiangsu Duxing Zhiyuan New Material Technology Co., Ltd.

[0048] Example 1

[0049] A method for preparing a photoinitiator FMT, the steps are as follows:

[0050] (1) After the reactor F1 was replaced with high-purity nitrogen three times, 100.00 kg of tetrahydrofuran and 20.00 kg of 2,4-difluorophenylpyrrole were added to the reactor in sequence under the protection of inert gas. After stirring evenly, samples were taken to measure the water content of the solution, which was <100 ppm.

[0051] (2) The temperature of reaction kettle F1 was lowered to -30°C, and 8.82 kg of lithium diethylamide was slowly added dropwise. After the addition was complete, the reaction was carried out at -30°C for 6 hours.

[0052] (3) The temperature of reactor F1 was maintained at -30°C, and 10.60 kg of titanium tetrachloride was slowly added dropwise. After the addition was completed, the reaction was carried out at -30°C for 8 hours to obtain a solution of the photoinitiator FMT intermediate.

[0053] (4) After the inert gas in reactor F2 was replaced three times, the reactor temperature was maintained at 0°C, and 60 kg of tetrahydrofuran solvent and 13.07 kg of sodium amide were added to the reactor in sequence. After stirring, 7.37 kg of cyclopentadiene was added dropwise. After the addition was complete, the reaction was allowed to proceed for 5 hours to obtain a purple sodium cyclopentadiene tetrahydrofuran solution.

[0054] (5) Keeping the temperature of reactor F1 at -20°C, add the purple sodium cyclopentadienyl tetrahydrofuran solution obtained in step (4) to the photoinitiator FMT intermediate solution in reactor F1. After the addition, react for 5 hours to obtain a photoinitiator FMT reaction solution.

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

[0056] (7) The temperature of the reactor F1 was lowered to 0°C, 100 kg of pure water was added to the crude photoinitiator FMT, and the mixture was stirred for 3 hours. The resulting solution was filtered through a filter to obtain a solid wet material.

[0057] (8) The solid wet material is placed in a vacuum dryer with a vacuum degree of -0.09 to 0.095 MPa, the temperature is raised to 90° C. to 95° C., and vacuum dried to obtain a photoinitiator FMT product.

[0058] The entire reaction was carried out under anhydrous and oxygen-free conditions.

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

[0060] 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 preparing a photoinitiator FMT, characterized in that: The synthetic route is as follows: The following steps are involved: The compound of formula I-1 reacts with an organometallic lithium to obtain a compound of formula I-2; The compound of formula I-2 reacts with titanium tetrachloride to obtain a compound of formula I-3; Cyclopentadiene reacts with sodium amide to obtain sodium cyclopentadiene; The compound of formula I-3 reacts with sodium cyclopentadiene to obtain the photoinitiator FMT shown in formula I.

2. The method for preparing the photoinitiator FMT according to claim 1, characterized in that: The specific steps include: (1) Under the protection of inert gas, add the compound of formula I-1 and organic solvent A into the reaction kettle F1 and mix them evenly; The organic solvent A is selected from one or more of benzene, toluene, xylene and tetrahydrofuran; (2) maintaining the temperature of the reaction kettle F1 at -50°C to -20°C, slowly adding organometallic lithium to the reaction kettle F1, and after the addition is completed, continuing the reaction for a period of time to obtain a solution containing the compound of formula I-2; (3) maintaining the temperature of the reaction kettle F1 at -50°C to -20°C, slowly adding titanium tetrachloride to the reaction kettle F1, and after the addition is completed, continuing the reaction for a period of time to obtain a solution containing the compound of formula I-3; (4) keeping the temperature of the reaction kettle F2 at -10°C to 10°C, under the protection of inert gas, adding tetrahydrofuran and sodium amide to the reaction kettle F2 and mixing them evenly, then adding cyclopentadiene dropwise, and after the addition is completed, continuing the reaction for a period of time to obtain a tetrahydrofuran solution of sodium cyclopentadiene; (5) The temperature of the reaction kettle F1 is maintained at -40°C to -10°C, and the tetrahydrofuran solution of sodium cyclopentadiene is added to the reaction kettle F1 to 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.

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

4. The method for preparing the photoinitiator FMT according to claim 2 or 3, characterized in that: In step (2), the organometallic lithium is selected from one or more of lithium diethylamide, butyl lithium, lithium diisopropylamide and benzyl lithium; The molar ratio of the organic metal lithium to the compound of formula I-1 is 1:1 to 1.

5.

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

5.

6. The method for preparing the photoinitiator FMT according to claim 2 or 3, characterized in that: In step (4), the volume ratio of tetrahydrofuran to cyclopentadiene is 1 to 10:1; The molar ratio of sodium amide to cyclopentadiene is 2-6:

1.

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

1.

8. The method for preparing the photoinitiator FMT according to claim 2 or 3, characterized in that: The following steps are also included: (6) maintaining the temperature of the reactor F1 at 100° C. to 120° C., removing the organic solvent A and tetrahydrofuran, and obtaining a crude photoinitiator FMT; (7) maintaining the temperature of the reactor F1 at 0° C. to 10° C., adding deionized water to the reactor F1, mixing with the crude photoinitiator FMT, stirring for a period of time, filtering, and obtaining a solid wet material; (8) vacuum drying the solid wet material to obtain a finished photoinitiator FMT product.

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