A method for separating and purifying a photoinitiator TPO

Abstract

The application provides a method for separating and purifying a photoinitiator TPO and relates to the field of separation and purification. The specific extraction method is as follows: a mixture containing the photoinitiator TPO is mixed with a solvent, solid-liquid separation is performed to obtain a solid phase A and a liquid phase B; the solid phase A is washed with water to obtain a product, i.e., a trimethylphenyl diphenyl phosphine oxide-based diphenyl phosphate; the washing liquid is combined with the liquid phase B to obtain a mixed liquid phase B; and a recrystallization method is used to treat an organic phase in the mixed liquid phase B to obtain the product, i.e., the photoinitiator TPO. The purification method is simple and easy to operate, the generation of solid waste is reduced, the cost for treating the solid waste is saved, the trimethylphenyl diphenyl phosphine oxide-based diphenyl phosphate with high added value contained in the mixture can be extracted, and the waste of resources is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of separation and purification, in particular to a method for separating and purifying a photoinitiator TPO. Background Art

[0002] TPO is a highly efficient free radical type I photoinitiator, with the Chinese name 2,4,6-trimethylbenzoyldiphenoxyphosphine (CAS: 75980-60-8). It can be used in UV-curing coatings, printing inks, UV-curing adhesives, optical fiber coatings, 3D printing and other fields. In the photoinitiator market, photoinitiator TPO is a variety with relatively large usage and scope of use.

[0003] In the preparation process of 2,4,6-trimethylbenzoyldiphenylphosphine disclosed in patent documents US4298738A, CN202210356950.2, CN110872320A, etc., petroleum ether is generally used as an extractant for product separation, and the product collection and post-processing process will produce solid waste. It is difficult to develop a treatment process for solid waste. Most manufacturers directly hand over the above solid waste to hazardous waste manufacturers for treatment, which is costly and wastes a lot of the high value-added product trimethylbenzene diphenyl phosphine oxide diphenyl phosphate (CAS: 2413630-62-1). As the application demand of TPO products expands, the scale of production also expands, resulting in an increase in the amount of solid waste, causing a burden on downstream processing. The split purification process of the present invention is green and environmentally friendly, and can also be used to treat the solid waste generated by existing process separation photoinitiator TPO.

[0004] Therefore, how to disclose a green and environmentally friendly method for separating and purifying photoinitiator TPO products to achieve high-quality production, and recycle and reuse solid waste to reduce production costs and reduce resource waste is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] The object of the present invention is to provide a method for separating and purifying a photoinitiator TPO, so as to solve the problem that the existing method generally uses petroleum ether to extract the photoinitiator TPO, which produces solid waste, is difficult to develop a treatment process for the solid waste, has a high cost for treatment by hazardous waste manufacturers, and also wastes mesitylene diphenyl phosphine oxide diphenyl phosphate in the solid waste.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for separating and purifying a photoinitiator TPO, comprising the following steps:

[0008] 1) mixing a mixture containing a photoinitiator TPO with a solvent, and performing solid-liquid separation to obtain a solid phase A and a liquid phase B;

[0009] 2) washing solid phase A with water to obtain mesitylene diphenylphosphine oxide diphenyl phosphate and a washing liquid, and combining the washing liquid with liquid phase B to obtain a mixed liquid phase B;

[0010] 3) The organic phase in the mixed liquid phase B is treated by recrystallization to obtain the product photoinitiator TPO.

[0011] Preferably, the solvent described in step 1) is Where 0≤x≤10, 0≤y≤12;

[0012] Z is one of -NH2, -CH3, -SO3H, -PO3H2 and -(CH3O)2PO;

[0013] The G - NO 3- 、Cl - Br - , I - PF 6- , BF 4- CF3SO 3- 、PhSO 3- 、(CH3CH2O)2PO - 、(CH3O)2PO - 、(CH3CH2CH2O)2PO - , (CF3)2N-, R'-COO- and R'-SO3-, wherein R' is an alkyl group.

[0014] Preferably, the mass ratio of the mixture containing the photoinitiator TPO to the solvent in step 1) is 0.5 to 5:1.

[0015] Preferably, the water content of the mixture containing the photoinitiator TPO in step 1) is 0-1 wt%.

[0016] Preferably, the solvent used in the recrystallization method in step 3) comprises one or more of NaOH solution, NaHCO3 solution, toluene, ethanol, ethyl acetate, DMF, DMSO, ether, hexane and water.

[0017] The present invention has at least the following beneficial effects:

[0018] The present invention discloses a method for extracting a photoinitiator TPO product. During the extraction process, a mixture containing the photoinitiator TPO is mixed with a solvent, and solid-liquid separation is performed to obtain a solid phase and a liquid phase. The solid phase is washed with water. During the washing process, impurities that are insoluble in the extractant but soluble in water are washed away, and TPO remaining on the surface of the solid phase is also washed away, thereby obtaining mesitylene diphenyl phosphine oxide-based diphenyl phosphate with higher purity. The washing liquid generated by washing the solid phase with water is mixed with the above-mentioned liquid phase, so that some impurities with better water solubility in the organic phase enter the aqueous phase. The organic phase is separated to obtain the organic phase, and the TPO in the organic phase is purified by recrystallization. By purifying TPO by the above-mentioned method, mesitylene diphenyl phosphine oxide-based diphenyl phosphate can be further extracted, thereby avoiding waste of resources, effectively solving the problem of high difficulty in solid waste treatment, reducing the production cost of TPO, and the environmentally friendly solvent can be recycled and reused, which is in line with the concept of green chemistry. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a process flow chart for separating and purifying the photoinitiator TPO according to the present invention. DETAILED DESCRIPTION

[0020] The present invention provides a method for separating and purifying a photoinitiator TPO, comprising the following steps:

[0021] 1) mixing a mixture containing a photoinitiator TPO with a solvent, and performing solid-liquid separation to obtain a solid phase A and a liquid phase B;

[0022] 2) washing solid phase A with water to obtain mesitylene diphenylphosphine oxide diphenyl phosphate and a washing liquid, and combining the washing liquid with liquid phase B to obtain a mixed liquid phase B;

[0023] 3) The organic phase in the mixed liquid phase B is treated by recrystallization to obtain the product photoinitiator TPO.

[0024] The specific separation and purification process is as follows Figure 1 shown.

[0025] In the present invention, the solvent described in step 1) is Among them, 0≤x≤10, preferably 2≤x≤8, more preferably 4≤x≤6, more preferably x=5; among them, 0≤y≤12, preferably 2≤y≤10, more preferably 4≤y≤8, more preferably 5≤y≤6.

[0026] In the present invention, the Z is one of -NH2, -CH3, -SO3H, -PO3H2 and -(CH3O)2PO; the G - NO 3- 、Cl - Br - , I - PF6- , BF 4- CF3SO 3- 、PhSO 3- 、(CH3CH2O)2PO - 、(CH3O)2PO - 、(CH3CH2CH2O)2PO - , (CF3)2N-, R'-COO- and R'-SO3-, wherein R' is an alkyl group, preferably a C2~C5 alkyl group, further preferably a C3~C5 alkyl group, and more preferably a C4~C5 alkyl group.

[0027] In the present invention, the solvent in step 1) is preferably an ionic liquid with a label number of LM1040 to LM1113 produced by Shanghai Chengjie Chemical Co., Ltd.

[0028] In the present invention, the mass ratio of the mixture containing the photoinitiator TPO to the solvent in step 1) is 0.5 to 5:1, preferably 1 to 4:1, more preferably 2 to 3:1, and more preferably 2.5:1.

[0029] In the present invention, the water content of the mixture containing the photoinitiator TPO in step 1) is 0-1 wt %, preferably 0.2-0.8 wt %, more preferably 0.4-0.6 wt %, and more preferably 0.5 wt %.

[0030] In the present invention, the recrystallization method described in step 3) uses a solvent comprising one or more of NaOH solution, NaHCO3 solution, toluene, ethanol, ethyl acetate, DMF, DMSO, ether, hexane and water, preferably a mixed solution of toluene and ethanol, and more preferably a mixed solution obtained by mixing toluene and ethanol in a volume ratio of 1:1.

[0031] In the present invention, the content of TPO in the mixture containing the photoinitiator TPO is 0 to 100 wt %, preferably 20 to 95 wt %, more preferably 40 to 80 wt %, and even more preferably 50 to 70 wt %.

[0032] In the present invention, the content of mesitylene diphenylphosphine oxide diphenyl phosphate in the mixture containing the photoinitiator TPO is 0-100%, preferably 20-90 wt %, more preferably 40-80 wt %, and even more preferably 50-70 wt %.

[0033] In the present invention, the mixture containing the photoinitiator TPO is preferably a primary product prepared according to the preparation process of 2,4,6-trimethylbenzoyldiphenoxyphosphine disclosed in patent documents US4298738A, CN202210356950.2, and CN110872320A, or solid waste generated after TPO is extracted with petroleum ether.

[0034] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0035] Example 1

[0036] 5 kg of the initial product containing TPO photoinitiator, comprising 80 wt% TPO and 8 wt% mesitylene diphenyl phosphine oxide diphenyl phosphate, with the remainder being impurities and unreacted raw materials, was added to a raw material storage tank and dried to reduce the moisture content to 0.5 wt%. The dried product was then passed into a stirred tank, where 1-methyl-3-ethylimidazolium bromide was added at a raw material to solvent ratio of 1:2. After thorough stirring, the product was placed in a scraper centrifuge for solid-liquid separation. The resulting solid phase was rinsed with pure water and dried to yield 0.38 kg of mesitylene diphenyl phosphine oxide diphenyl phosphate with a purity of 97.5%. The washing liquid from washing the solid phase was mixed with the liquid phase to form a mixed solution. The mixed solution was allowed to stand and separated to yield an organic phase and an aqueous phase. The aqueous phase was placed in a flash evaporator, where the steam was recycled to the oil-water separator tank. The solvent was recycled to the solvent storage tank for recovery and reuse, with a solvent loss of 0.1%. The organic phase was placed in an oil-water separation tank and recrystallized once with a toluene / ethanol mixed solution with a mass ratio of 1:1 to remove impurities, thereby obtaining 3.75 kg of TPO product with a purity of 98.5%.

[0037] Example 2

[0038] 5 kg of solid waste containing TPO photoinitiator, comprising 8% TPO and 75% mesitylene diphenyl phosphine oxide diphenyl phosphate, with the remainder consisting of impurities and unreacted raw materials, was added to a raw material storage tank and dried to reduce the moisture content to 0.5% by weight. The dried material was then passed into a stirred tank, where 1-ethyl-3-propylaminoimidazole bromide was added at a raw material to solvent ratio of 1:2. After thorough stirring, the material was placed in a scraper centrifuge for solid-liquid separation. The resulting solid phase was rinsed with pure water and dried to yield 3.8 kg of mesitylene diphenyl phosphine oxide diphenyl phosphate with a purity of 98%. The washing liquid obtained from washing the solid phase was mixed with the liquid phase to form a mixed solution. The mixed solution was allowed to stand and separated to yield an organic phase and an aqueous phase. The aqueous phase was placed in a flash tank, where the steam was circulated to the oil-water separator tank. The solvent was circulated to the solvent storage tank for recovery and reuse, resulting in a solvent loss of 0.2%. The organic phase was placed in an oil-water separation tank, and toluene and NaOH aqueous solution were mixed in a mass ratio of 1:1 to obtain a mixed solvent. The oil phase was recrystallized once using the mixed solvent to remove impurities, thereby obtaining 0.35 kg of TPO product with a purity of 95.8%.

[0039] Example 3

[0040] 5 kg of solid waste containing TPO photoinitiator, comprising 8 wt% TPO and 75 wt% mesitylene diphenyl phosphine oxide diphenyl phosphate, with the remainder consisting of impurities and unreacted raw materials, was added to a raw material storage tank and dried to reduce the moisture content to 0.5 wt%. The dried material was then passed into a stirred tank, where 1-butyl-3-methylimidazole p-toluenesulfonate (LM1053, from Shanghai Chengjie Chemical Co., Ltd.) was added at a raw material to solvent ratio of 1:1.5. After thorough stirring, the material was placed in a scraper centrifuge for solid-liquid separation. The resulting solid phase was rinsed with pure water and dried to yield 3.68 kg of mesitylene diphenyl phosphine oxide diphenyl phosphate with a purity of 98.4%. The washing liquid from washing the solid phase was mixed with the liquid phase to form a mixed solution. The mixed solution was allowed to stand and separated to yield an organic phase and an aqueous phase. The aqueous phase was placed in a flash evaporator, where the steam was recycled to the oil-water separator tank. The solvent was recycled to the solvent storage tank for reuse, resulting in a solvent loss of 0.28%. The organic phase was placed in an oil-water separation tank, and toluene and sodium bicarbonate aqueous solution were mixed in a mass ratio of 1:1 to obtain a mixed solvent. The oil phase was recrystallized once using the mixed solvent to remove impurities, thereby obtaining 0.28 kg of TPO product with a purity of 96%.

[0041] Example 4

[0042] 5 kg of solid waste containing TPO photoinitiator, comprising 8 wt% TPO and 75 wt% mesitylene diphenyl phosphine oxide diphenyl phosphate, with the remainder consisting of impurities and unreacted raw materials, was added to a raw material storage tank and dried to reduce the moisture content to 0.5 wt%. The dried material was then passed into a stirred tank, where 1-octyl-3-methylimidazolium trifluoromethanesulfonate (LM1103, Shanghai Chengjie Chemical Co., Ltd.) was added at a raw material to solvent ratio of 2:1. After thorough stirring, the material was placed in a scraper centrifuge for solid-liquid separation. The resulting solid phase was rinsed with pure water and dried to yield 3.68 kg of mesitylene diphenyl phosphine oxide diphenyl phosphate with a purity of 98.2%. The washing liquid from washing the solid phase was mixed with the liquid phase to form a mixed solution. The mixed solution was allowed to stand and separated to yield an organic phase and an aqueous phase. The aqueous phase was placed in a flash evaporator, where the steam was circulated to the oil-water separator tank. The solvent was circulated to the solvent storage tank for recovery and reuse, resulting in a solvent loss of 0.2%. The organic phase was placed in an oil-water separation tank, and DMSO and ether were mixed in a mass ratio of 1:1 to obtain a mixed solvent. The oil phase was recrystallized once using the mixed solvent to remove impurities, obtaining 0.33 kg of TPO product with a purity of 97.5%.

[0043] Example 5

[0044] 5 kg of solid waste containing TPO photoinitiator, comprising 8 wt% TPO and 75 wt% mesitylene diphenyl phosphine oxide diphenyl phosphate, with the remainder consisting of impurities and unreacted raw materials, was added to a raw material storage tank and dried to reduce the moisture content to 0.5 wt%. The dried material was then passed into a stirred tank, where 1-butyl-3-methylimidazolium methanesulfonate (LM1046, Shanghai Chengjie Chemical Co., Ltd.) was added at a raw material to solvent ratio of 4:1. After thorough stirring, the material was placed in a scraper centrifuge for solid-liquid separation. The resulting solid phase was rinsed with pure water and dried to yield 3.47 kg of mesitylene diphenyl phosphine oxide diphenyl phosphate with a purity of 93.7%. The washing liquid from washing the solid phase was mixed with the liquid phase to form a mixed solution. The mixed solution was allowed to stand and separated to yield an organic phase and an aqueous phase. The aqueous phase was placed in a flash evaporator, where the steam was recycled to the oil-water separator tank. The solvent was recycled to the solvent storage tank for recovery and reuse, resulting in a solvent loss of 0.2%. The organic phase was placed in an oil-water separation tank, and toluene and NaOH aqueous solution were mixed in a mass ratio of 1:1 to obtain a mixed solvent. The oil phase was recrystallized once using the mixed solvent to remove impurities, thereby obtaining 0.35 kg of TPO product with a purity of 95.8%.

[0045] Example 6

[0046] 5 kg of solid waste containing TPO photoinitiator, comprising 8 wt% TPO and 75 wt% mesitylene diphenyl phosphine oxide diphenyl phosphate, with the remainder consisting of impurities and unreacted raw materials, was added to a raw material storage tank and dried to reduce the moisture content to 0.5 wt%. The dried material was then passed into a stirred tank, where 1-butyl-3-methylimidazoline sulfate (LM1058, Shanghai Chengjie Chemical Co., Ltd.) was added at a raw material to solvent ratio of 5:2. After thorough stirring, the material was placed in a scraper centrifuge for solid-liquid separation. The resulting solid phase was rinsed with pure water and dried to yield 3.84 kg of mesitylene diphenyl phosphine oxide diphenyl phosphate with a purity of 97.3%. The washing liquid from washing the solid phase was mixed with the liquid phase to form a mixed solution. The mixed solution was allowed to stand and separated to yield an organic phase and an aqueous phase. The aqueous phase was placed in a flash tank, where the steam was recycled to the oil-water separator tank. The solvent was recycled to the solvent storage tank for recovery and reuse, resulting in a solvent loss of 0.28%. The organic phase was placed in an oil-water separation tank, and toluene and ethyl acetate were mixed in a mass ratio of 1:1 to obtain a mixed solvent. The oil phase was recrystallized once using the mixed solvent to remove impurities, obtaining 0.40 kg of TPO product with a purity of 94.7%.

[0047] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for separating and purifying a photoinitiator TPO, characterized in that: The following steps are involved: 1) Mixing a mixture containing a photoinitiator TPO with a solvent and performing solid-liquid separation to obtain a solid phase A and a liquid phase B; 2) Wash solid phase A with water to obtain and a washing liquid, combining the washing liquid with liquid phase B to obtain a mixed liquid phase B; 3) The organic phase in the mixed liquid phase B is treated by recrystallization to obtain the product photoinitiator TPO; The solvent in step 1) is selected from one of 1-methyl-3-ethylimidazolium bromide, 1-ethyl-3-propylaminoimidazolium bromide, 1-butyl-3-methylimidazolium p-toluenesulfonate, 1-octyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium methanesulfonate and 1-butyl-3-methylimidazolium octane sulfate.

2. The method for separating and purifying the photoinitiator TPO according to claim 1, characterized in that: The mass ratio of the mixture containing the photoinitiator TPO to the solvent in step 1) is 0.5-5:

1.

3. The method for separating and purifying the photoinitiator TPO according to claim 2, characterized in that: The water content of the mixture containing the photoinitiator TPO in step 1) is 0-1 wt%.

4. The method for separating and purifying a photoinitiator TPO according to any one of claims 1 to 3, characterized in that: The solvent used in the recrystallization method described in step 3) includes one or more of NaOH solution, NaHCO3 solution, toluene, ethanol, ethyl acetate, DMF, DMSO, ether, hexane and water.

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