Initiator premixing process

Abstract

The present application relates to a pre-mixing method of initiator in the field of high pressure polymerization of olefins, and particularly relates to a pre-mixing method of initiator, which comprises the following steps: (1) mixing at least two initiators to obtain a first initiator mixture; (2) mixing the first initiator mixture with at least one solvent in at least one multi-channel mixer to obtain a second initiator mixture. The pre-mixing method provided by the present application is used in a continuous polymerization process, and through the rapid mixing of the solvent and the initiator in the multi-channel mixing structure, the initiator preparation time can be reduced, the product quality index fluctuation caused by the initiator mixing can be significantly reduced, the product quality index is more stable, the transition material in the start-up and grade switching process is less, and the device economy is good.

Description

Technical Field

[0001] This invention relates to a method for premixing initiators in the field of high-pressure polymerization of olefins, and specifically to an initiator premixing method. Background Technology

[0002] High-pressure free radical polymerization is an important process for producing low-density polyethylene (LDPE), and its products are widely used in films, injection molding, and power cables. The reaction conditions for high-pressure free radical polymerization are extremely harsh, with reaction pressures of approximately 100 MPa-300 MPa and reaction temperatures of approximately 140℃-350℃.

[0003] Free radical initiators are key components for initiating the free radical polymerization of ethylene. Generally, a combination of multiple initiators is required. This is especially true for tubular reactors, where the reaction temperature journey is long, typically reaching up to 140°C. Therefore, for tubular reactors, at least three initiators are usually needed to cover the entire reaction temperature range.

[0004] As is well known in the art, initiators used for high-pressure free polymerization of ethylene, such as organic peroxides, are unstable. When their auto-accelerating decomposition temperature is exceeded, they readily undergo thermal decomposition, leading to reduced initiator efficiency and failure to meet polymerization reaction requirements, while also posing safety risks. A common approach is premixing, where organic peroxides are formulated in specific proportions according to the production grade requirements and diluted to a specific concentration with a solvent. Existing industrial equipment and methods are labor-intensive, time-consuming, and lack flexibility.

[0005] CN102281943B proposes an initiator feeding method that uses multiple initiator feed pumps to simultaneously introduce different initiators and solvents into a static mixer, thereby achieving mixing of the initiator and solvent. However, this method requires high precision from the initiator feed pumps. If the initiator feed pumps are not precise or malfunction, it will lead to deviations in the initiator ratio, and may even significantly affect the temperature distribution in the reactor and the product quality.

[0006] Therefore, the present invention proposes an initiator premixing device and method, which improves the mixing method of initiators to achieve rapid mixing of different initiators and solvents. Summary of the Invention

[0007] The purpose of this invention is to overcome the problems of long initiator premixing time, insufficient mixing, and high manpower consumption in the high-pressure ethylene free radical polymerization process of the prior art, and to provide an initiator premixing method. This method and device have the advantages of short initiator mixing time, sufficient mixing, and saving manpower.

[0008] To achieve the above objectives, the present invention provides an initiator premixing method, the premixing method comprising:

[0009] (1) A first initiator mixture is obtained by mixing at least two initiators;

[0010] (2) The first initiator mixture is mixed with at least one solvent in at least one multichannel mixer to obtain a second initiator mixture.

[0011] Preferably, the premixing method is carried out in a premixing apparatus, the premixing apparatus comprising:

[0012] A first stirring mixing vessel is used to mix at least two initiators to obtain a first initiator mixture;

[0013] A microchannel type multichannel mixer or an impact type multichannel mixer connected to the first mixing tank;

[0014] The microchannel multichannel mixer includes:

[0015] A first housing and a first receiving cavity formed around the first housing, wherein the first housing is provided with a solvent inlet and an initiator inlet;

[0016] At least one internal component disposed within the first receiving cavity and fixedly connected to the first housing; or

[0017] The impact-type multichannel mixer includes: a T-shaped second housing and a second receiving cavity formed around the second housing;

[0018] The solvent inlet and the initiator inlet are located on both sides of the second housing of the T-shaped structure;

[0019] The mixture outlet is located at the bottom of the second housing of the T-shaped structure;

[0020] The premixing method includes:

[0021] (1) At least two initiators are mixed in a first stirred mixing tank to obtain a first initiator mixture;

[0022] (2) The first initiator mixture is mixed with at least one solvent in the microchannel type multichannel mixer or the impact type multichannel mixer to obtain a second initiator mixture.

[0023] Compared with the prior art, the advantages of this invention are:

[0024] The initiator premixing method proposed in this invention can reduce the initiator preparation time by rapidly mixing the solvent and initiator in a multi-channel mixing structure, which has good economic benefits. The solvent does not need to be mixed with the initiator in the first stirring mixing tank, saving the volume of the first stirring mixing tank, reducing the footprint of the device, shortening the initiator mixing time, and ensuring that the mixing is thorough.

[0025] The initiator premixing method proposed in this invention is used in continuous polymer production processes. The initiator mixing significantly reduces fluctuations in product quality indicators, making the product quality indicators more stable. Furthermore, it reduces the amount of transition material during start-up and grade switching, resulting in good equipment economy. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a high-pressure free radical polymerization reaction process using a tubular reactor;

[0027] Figure 2 This is a schematic diagram of an initiator premixing device according to one embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of a microchannel multichannel mixer structure according to a preferred embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of a preferred embodiment of the impact-type multichannel mixer of the present invention.

[0030] Explanation of reference numerals in the attached figures

[0031] 1—Recycled feed compressor; 2—First compressor;

[0032] 3—Second compressor; 4—Preheater;

[0033] 5—First tubular reactor; 6a—Second tubular reactor;

[0034] 6b—Third tubular reactor; 7—High-pressure pressure reducing valve;

[0035] 8—Cooler; 9—High-pressure separator;

[0036] 10—High-pressure circulation loop; 11—Low-pressure separator;

[0037] 12—Low-circulation loop; 13a—First feed pump;

[0038] 13b—Second feed pump; 13c—Third feed pump;

[0039] 14—First feed inlet; 15—Second feed inlet;

[0040] 21—Solvent transfer pump; 22a—First mixing tank;

[0041] 22b—Second mixing tank; 23—First initiator mixture delivery pump;

[0042] 24—Multi-channel mixer; 25a—First storage tank;

[0043] 25b—Second storage tank; 25c—Third storage tank;

[0044] 25d—Fourth storage tank; 41—Microchannel type multichannel mixer;

[0045] 42—Internal components; 43—Solvent inlet;

[0046] 44—Initiator inlet; 45—Material outlet;

[0047] 46—First housing; 51—Impact-type multichannel mixer;

[0048] 52—Solvent inlet; 53—Initiator inlet;

[0049] 54—Mixture outlet; 55—Second shell. Detailed Implementation

[0050] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0051] Unless otherwise stated, directional terms such as "upstream" and "downstream" refer to the direction of material flow within the device.

[0052] This invention provides an initiator premixing method, the premixing method comprising:

[0053] (1) A first initiator mixture is obtained by mixing at least two initiators;

[0054] (2) The first initiator mixture is mixed with at least one solvent in at least one multichannel mixer to obtain a second initiator mixture.

[0055] The initiator premixing method proposed in this invention can reduce the initiator preparation time by rapidly mixing the solvent and initiator in a multi-channel mixing structure, which has good economic benefits. The solvent does not need to be mixed with the initiator in the first stirring mixing tank, saving the volume of the first stirring mixing tank, reducing the footprint of the device, shortening the initiator mixing time, and ensuring that the mixing is thorough.

[0056] According to a preferred embodiment of the present invention, the premixing method is carried out in a premixing apparatus, the premixing apparatus comprising:

[0057] A first stirring mixing tank 22a is used to mix at least two initiators to obtain a first initiator mixture;

[0058] A microchannel type multichannel mixer 41 or an impact type multichannel mixer 51 connected to the first mixing tank 22a;

[0059] The microchannel multichannel mixer 41 includes:

[0060] The first housing 46 and the first housing 46 surround the first receiving cavity formed thereon, and the first housing is provided with a solvent inlet 43 and an initiator inlet 44;

[0061] At least one internal component 42 is disposed within the first receiving cavity and fixedly connected to the first housing 46;

[0062] or

[0063] The impact-type multichannel mixer 51 includes: a T-shaped second housing 55 and a second receiving cavity formed around the second housing 55;

[0064] Solvent inlet 52 and initiator inlet 53 are located on both sides of the second housing 55 of the T-shaped structure;

[0065] The mixture outlet 54 is located at the bottom of the second housing 55 of the T-shaped structure;

[0066] The premixing method includes:

[0067] (1) At least two initiators are mixed in a first stirred mixing tank 22a to obtain a first initiator mixture;

[0068] (2) The first initiator mixture is mixed with at least one solvent in the microchannel type multichannel mixer 41 or the impact type multichannel mixer 51 to obtain a second initiator mixture.

[0069] The initiator premixing method proposed in this invention is used in continuous polymer production processes. The initiator mixing significantly reduces fluctuations in product quality indicators, making the product quality indicators more stable. Furthermore, it reduces the amount of transition material during start-up and grade switching, resulting in good equipment economy.

[0070] According to a preferred embodiment of the present invention, valves are provided on each material flow pipeline to control the flow rate of the material.

[0071] According to a preferred embodiment of the present invention, when the multichannel mixer 24 is a microchannel type multichannel mixer 41, the premixing method includes:

[0072] The first initiator mixture enters the first containment cavity from at least one initiator inlet 44, and the solvent enters the first containment cavity from the solvent inlet 43; the solvent and the first initiator mixture flow through several internal components 42 in the first containment cavity to be mixed to obtain the second initiator mixture. By adopting the aforementioned preferred method, rapid mixing of different materials can be achieved.

[0073] According to a preferred embodiment of the present invention, when the multichannel mixer 24 is an impact-type multichannel mixer 51, the premixing method includes:

[0074] The solvent enters the second containment chamber through the solvent inlet 52; the first initiator mixture enters the second containment chamber through the initiator inlet 53. The solvent and the first initiator mixture are rapidly mixed by high-speed collision in the second containment chamber to obtain the second initiator mixture, which is output from the mixture outlet 54. By adopting the aforementioned preferred method, rapid mixing of different materials can be achieved.

[0075] According to a preferred embodiment of the present invention, in step (2), the flow rate of the material entering the multi-channel mixer 24 is 0.1-20 m / s.

[0076] According to a preferred embodiment of the present invention, the feed rate of the solvent is 0.5-10 m / s, and the feed rate of the first initiator mixture is 0.5-10 m / s.

[0077] According to a preferred embodiment of the present invention, the initiator is selected from at least one of organic peroxide initiators, and preferably, the temperature corresponding to the 1-hour half-life of the initiator is 70-150°C.

[0078] According to a preferred embodiment of the present invention, the initiator is selected from at least one of organic peroxides, peroxy ketals, peroxy ketones, and peroxy carbonates.

[0079] According to a preferred embodiment of the present invention, the initiator is selected from peroxide esters, peroxide ketals, peroxide ketones, and peroxide carbonates, such as di(2-ethylhexyl) peroxydicarbonate, dicyclohexyl peroxydicarbonate, diacetyl peroxydicarbonate, tert-butyl peroxyisopropyl carbonate, di-tert-butyl peroxide, di-tert-pentyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di-tert-butylperoxyhexane, tert-butylcumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hex-3-yne, 1,3-diisopropyl monohydroperoxide or tert-butyl hydroperoxide, didecyl peroxide, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, tert-pentyl peroxy-2-ethylhexanoate, dibenzoyl peroxide, peroxydicarbonate, etc. At least one of the following: 2-ethylhexanoate tert-butyl peroxydiethylacetic acid tert-butyl peroxydiethylisobutyrate tert-butyl peroxy-3,5,5-trimethylhexanoate tert-butyl peroxy-3,3,5-trimethylcyclohexane, 1,1'-di(tert-butylperoxy)cyclohexane, 1,1'-di(tert-butylperoxy)cyclohexane, peroxyacetic acid tert-butyl peroxyneodecanate, peroxyneodecanate tert-pentyl peroxyneodecanate, peroxyneodecanate tert-pentyl peroxyneodecanate, peroxyneodecanate tert-butyl peroxyneodecanate, permaleate tert-butyl peroxyneodecanate tert-butyl peroxyneonoate, dicumyl hydroperoxide, cumene hydroperoxide, tert-butyl peroxybenzoate, methyl isobutyl ketone hydroperoxide, 3,6,9-triethyl-3',6',9'-trimethyltriperoxycyclononane and 2,2'-di(tert-butylperoxy)butane.

[0080] According to a preferred embodiment of the present invention, the solvent is selected from C6-C. 15 At least one of alkanes or alkenes, preferably C9-C 12 A mixture of alkanes, such as at least one of n-nonane, n-decane, isodecane, isoundecane, and isododecane.

[0081] According to a preferred embodiment of the present invention, in step (2), the mass ratio of the initiator mixture to the solvent is 1:1.5-9.

[0082] According to a preferred embodiment of the present invention, the inner component 42 is at least one of a rectangular baffle, a serpentine channel, a butterfly baffle, and a herringbone groove.

[0083] According to a preferred embodiment of the present invention, in the microchannel type multichannel mixer 41, the included angle of the pipelines connected to the solvent inlet 43 and the initiator inlet 44 along the material flow direction is ≥60°.

[0084] According to a preferred embodiment of the present invention, the premixing device further includes a storage tank connected to the outlet of the multichannel mixer 24 for storing the second initiator mixture.

[0085] According to a preferred embodiment of the present invention, at least three storage tanks connected in parallel are provided for storing second initiator mixtures with different formulations; more preferably, three to six storage tanks are provided.

[0086] According to a preferred embodiment of the present invention, a second stirring mixing tank 22b is further provided between the multi-channel mixer 24 and the storage tank for secondary mixing of the second initiator mixture.

[0087] According to a preferred embodiment of the present invention, the microchannel type multichannel mixer 41 has a jacket provided outside the first housing 46 for external heat exchange medium to flow and exchange heat with the microchannel type multichannel mixer 41.

[0088] According to a preferred embodiment of the present invention, the impact-type multi-channel mixer 51 has a jacket outside the second housing 55 for external heat exchange medium to flow and exchange heat with the impact-type multi-channel mixer 51.

[0089] According to a preferred embodiment of the present invention, each unit is provided with a drive unit for conveying materials through its material inlet and / or inlet and outlet.

[0090] According to a preferred embodiment of the present invention, the driving unit is a delivery pump.

[0091] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0092] Initiator premixing method I: In such Figure 2 The multichannel mixer 24 is performed in the apparatus shown. Figure 3 The microchannel multichannel mixer 41 shown includes an initiator premixing method comprising:

[0093] (1) At least two initiators are mixed in a first stirred mixing tank 22a to obtain a first initiator mixture;

[0094] (2) The first initiator mixture is conveyed by the delivery pump 23 and enters the first containment cavity from at least one initiator inlet 44. The solvent is conveyed by the delivery pump 21 from the solvent inlet 43 into the first containment cavity. The solvent and the first initiator mixture flow through several internal components 42 in the first containment cavity to be mixed to obtain the second initiator mixture.

[0095] (3) The second initiator mixture is transported to the second mixing tank 22b, and after the second initiator mixture is mixed a second time, it is transported to the first storage tank 25a, the second storage tank 25b, the third storage tank 25c, or the fourth storage tank 25d.

[0096] Initiator premixing method II: In such Figure 2 The multichannel mixer 24 is performed in the apparatus shown. Figure 3 The impingement-type multichannel mixer 51 shown includes an initiator premixing method comprising:

[0097] (1) At least two initiators are mixed in a first stirred mixing tank 22a to obtain a first initiator mixture;

[0098] (2) The first initiator mixture is conveyed by the first initiator mixture conveying pump 23 and enters the second containment chamber from the initiator inlet 53. The solvent is conveyed by the solvent conveying pump 21 and enters the second containment chamber through the solvent inlet 52. The solvent and the first initiator mixture are rapidly mixed by high-speed collision in the second containment chamber to obtain the second initiator mixture, which is output from the mixture outlet 54.

[0099] (3) The second initiator mixture is transported to the second mixing tank 22b, and after the second initiator mixture is mixed a second time, it is transported to the first storage tank 25a, the second storage tank 25b, the third storage tank 25c, or the fourth storage tank 25d.

[0100] The present invention will be further illustrated below with reference to specific embodiments. However, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0101] In the following embodiments,

[0102] The first initiator mixture i consists of tert-butyl neopentyl peroxide, tert-butyl peroxide-2-ethylhexyl ester, tert-butyl peroxide benzoate, and di-tert-butyl peroxide in a mass ratio of 3:4:4:2.

[0103] The first initiator mixture ii: the mass ratio of tert-butyl peroxide-2-ethylhexyl ester, tert-butyl peroxide benzoate, and di-tert-butyl peroxide is 1:2:7.

[0104] First initiator mixture iii: tert-butyl peroxide-2-ethylhexyl ester, tert-butyl peroxide benzoate, di-tert-butyl peroxide 1:2:12.

[0105] Second initiator mixture i: 25 wt% of first initiator mixture i, 75 wt% isododecane solvent.

[0106] Second initiator mixture ii: 25 wt% of first initiator mixture ii, 75 wt% isododecane solvent.

[0107] Second initiator mixture iii: 25 wt% of first initiator mixture iii, 75 wt% isododecane solvent.

[0108] Example 1

[0109] To prepare the initiator / solvent solution for the 200,000-ton LDPE polymerization unit, the second initiator mixture i-iii was obtained by mixing using method II:

[0110] The first mixing tank 22a has a volume of 0.6 m³. 3 The second mixing tank 22b has a volume of 1.8m³. 3 The storage tanks all have a volume of 1.0 m³. 3 .

[0111] In step (2), the feed rate of the first initiator mixture is 2 m / s; the feed rate of the solvent is 5 m / s; and the initiator preparation time is 48 minutes.

[0112] Example 2

[0113] To prepare an initiator / solvent solution for a 200,000-ton LDPE polymerization unit, a second initiator mixture i-iii is obtained by mixing using method I. The included angle between the pipes connecting the solvent inlet and the initiator inlet is 60°.

[0114] The first mixing tank 22a has a volume of 0.6 m³. 3 The second mixing tank, 22b, has a volume of 1.8 m³. 3 The storage tanks all have a volume of 1.0 m³. 3 .

[0115] In step (2), 10 parallel microchannel type multichannel mixers 41 are used. The inlet radius of each microchannel is 5mm, the length is 12m, and the outlet material flow rate is 2m / s.

[0116] The internal components 42 of the microchannel type multichannel mixer 41 are rectangular baffles, and the number of baffles is 12; the initiator preparation time is 50 minutes.

[0117] Comparative Example 1

[0118] The initiator / solvent solution was prepared for a 200,000-ton LDPE polymerization unit, with all other conditions the same as in Example 1, except that:

[0119] The volume of the first mixing tank is 2.1 m³. 3 The first storage tank has a volume of 1.0 m³. 3 Both the initiator and solvent are sent to the first mixing tank, stirred and mixed, and then sent to the storage tank. The initiator preparation time is 64 minutes.

[0120] The second initiator mixture prepared according to the methods of Examples 1, 2 and Comparative Example 1 was subjected to a high-pressure free radical reaction;

[0121] High-pressure free radical polymerization is carried out in a tubular reactor, wherein the high-pressure free radical polymerization reaction is carried out in a manner such as... Figure 1 The polymerization reaction is carried out in the system shown, which includes:

[0122] The first compressor 2, the second compressor 3, the preheater 4 are connected in series, and the first tubular reactor 5, the second tubular reactor 6a, and the third tubular reactor 6b are connected in series downstream of the preheater 4.

[0123] A high-pressure reducing valve 7, a cooler 8, and a high-pressure separator 9 are sequentially installed downstream of the third tubular reactor 6b.

[0124] The low-pressure separator 11 and the circulating feed compressor 1 are connected in series with the high-pressure separator 9;

[0125] A first feed pump 14, a second feed pump 15, and a third feed pump 16, connected in parallel with the preheater 4 and respectively connected to the first tubular reactor 5, the second tubular reactor 6a, and the third tubular reactor 6b, are used to input the initiator into the tubular reactors.

[0126] First compressor 2 pressurizes the fresh ethylene stream;

[0127] A feed inlet 13 is provided between the first compressor 2 and the second compressor 3 for inputting comonomer and polymerizer streams;

[0128] The second compressor 3 provides a second pressurization to the ethylene monomer stream, comonomer, and polymerization modifier stream;

[0129] The high-pressure separator 9 is used to separate at least a portion of the light components and at least a portion of the heavy components in the material at the outlet of the cooler 8 from the polyethylene and form a high-pressure circulating stream, while the remaining light components, heavy components and polyethylene are sent downstream.

[0130] High-pressure circulating circuit 10 is used to transport the high-pressure circulating material to the feed inlet 13;

[0131] A low-pressure separator 11, located downstream of the high-pressure separator 9 and connected in parallel with the high-pressure circulating circuit, is used to separate light and heavy components in polyethylene to form a low-pressure circulating stream.

[0132] Low-pressure circulating circuit 12 is used to circulate the low-pressure circulating material to the first compressor 2;

[0133] A circulating material compressor 1 is installed on the low-pressure circulating circuit 12 to pressurize the low-pressure circulating material.

[0134] The first feed inlet 14 is located upstream of the first compressor 2 and is used for feeding fresh ethylene and the low-pressure circulating stream.

[0135] The second feed inlet 15 is located between the first compressor 2 and the second compressor 3; it is used for feeding at least one of the comonomer, polymerizing agent and the high-pressure circulating stream.

[0136] The high-pressure free radical polymerization method, in such a way... Figure 1 The polymerization reaction is carried out in the system shown, and the method includes:

[0137] Fresh ethylene and low-pressure circulating feed enter the reaction system through the first feed port 14. After being pressurized by the first compressor 2, they are mixed with the comonomer, polymerization regulator and high-pressure circulating feed entering from the second feed port 15. The mixture is then pressurized again in the second compressor 3. The pressurized feed is preheated in the preheater 4 and then sequentially conveyed to the first tubular reactor 5, the second tubular reactor 6a and the third tubular reactor 6b to react with the initiator mixture.

[0138] The effluent from the third tubular reactor 6b is depressurized by the high-pressure reducing valve 7 and cooled by the cooler 8 before being sent to the high-pressure separator 9 for separation. At least a portion of the light components and at least a portion of the heavy components are separated from the polyethylene and form a high-pressure circulating stream. The remaining light components, heavy components and polyethylene are sent to the low-pressure separator 11 to separate polyethylene, wherein the light components and heavy components form a low-pressure circulating stream.

[0139] The high-pressure circulating material is conveyed to the second inlet 15 via the high-pressure circulation loop 10, and the low-pressure circulating material is conveyed to the second inlet 14 via the low-pressure circulation loop 12.

[0140] The second initiator mixture i is injected into the first tubular reactor 5; the second initiator mixture ii is injected into the second tubular reactor 6a; and the second initiator mixture iii is injected into the third tubular reactor 6b.

[0141] The second initiator mixtures i-iii prepared in Examples 1, 2 and Comparative Example 1 were evaluated according to the aforementioned method, and the test results are shown in Table 1.

[0142] Table 1

[0143]

[0144] As can be seen from the results in Table 1, the embodiments of the present invention can shorten the initiator mixing time and improve the mixing effect of the initiator, resulting in lower initiator consumption and more stable product quality indicators.

[0145] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for premixing an initiator, characterized in that, The premixing method is carried out in a premixing apparatus, which includes: A first stirring mixing vessel (22a) is used to mix at least two initiators to obtain a first initiator mixture; A microchannel type multichannel mixer (41) or an impact type multichannel mixer (51) connected to the first mixing tank (22a); The microchannel multichannel mixer (41) includes: The first housing (46) and the first housing (46) surround the first receiving cavity, and the first housing is provided with a solvent inlet (43) and an initiator inlet (44). At least one internal component (42) disposed within the first receiving cavity and fixedly connected to the first housing (46); the internal component (42) is at least one of a rectangular baffle, a serpentine channel, a butterfly-shaped baffle, and a herringbone groove; in the microchannel type multichannel mixer (41), the included angle of the pipelines connected to the solvent inlet (43) and the initiator inlet (44) along the material flow direction is ≥60°; or The impact-type multichannel mixer (51) includes: a second housing (55) of a T-shape and a second receiving cavity formed around the second housing (55); Solvent inlet (52) and initiator inlet (53) are located on both sides of the second housing (55) of the T-shaped structure; The mixture outlet (54) is located at the bottom of the second housing (55) of the T-shaped structure; The premixing method includes: (1) At least two initiators are mixed in a first stirred mixing tank (22a) to obtain a first initiator mixture; (2) The first initiator mixture is mixed with at least one solvent in the microchannel type multichannel mixer (41) or the impact type multichannel mixer (51) to obtain a second initiator mixture.

2. The premixing method according to claim 1, wherein, When the first mixing tank (22a) is connected to the microchannel type multichannel mixer (41), the premixing method includes: The first initiator mixture enters the first containment cavity from at least one initiator inlet (44), and the solvent enters the first containment cavity from the solvent inlet (43); the solvent and the first initiator mixture flow through several internal components (42) in the first containment cavity to mix and obtain a second initiator mixture; or When the first mixing tank (22a) is connected to the impact-type multichannel mixer (51), the premixing method includes: The solvent enters the second containment chamber through the solvent inlet (52); the first initiator mixture enters the second containment chamber through the initiator inlet (53), and the solvent and the first initiator mixture are rapidly mixed by high-speed collision in the second containment chamber to obtain the second initiator mixture, which is output from the mixture outlet (54) to obtain the second initiator mixture.

3. The premixing method according to claim 1 or 2, wherein, In step (2), the flow rate of the material entering the microchannel type multichannel mixer (41) or the impact type multichannel mixer (51) is 0.1-20 m / s.

4. The premixing method according to claim 1 or 2, wherein, In step (2), the feed rate of the solvent is 0.5-10 m / s, and the feed rate of the first initiator mixture is 0.5-10 m / s.

5. The premixing method according to claim 1 or 2, wherein, The initiator is selected from at least one of organic peroxide initiators, and the temperature corresponding to the 1-hour half-life of the initiator is 70-150°C. and / or The solvent is selected from C6-C. 15 At least one of the alkanes or alkenes.

6. The premixing method according to claim 1 or 2, wherein, The initiator is selected from at least one of organic peroxides, peroxy ketals, peroxy ketones, and peroxy carbonates; and / or The solvent is at least one selected from n-nonane, n-decane, isodecane, isoundecane, and isododecane.

7. The premixing method according to claim 1 or 2, wherein, In step (2), the mass ratio of the initiator mixture to the solvent is 1:1.5-9.

8. The premixing method according to claim 1, wherein, The premixing device further includes a storage tank connected to the outlet of the multichannel mixer (24) for storing the second initiator mixture.

9. The premixing method according to claim 8, wherein, At least three parallel-connected storage tanks are provided for storing mixtures of second initiators with different formulations.

10. The premixing method according to claim 8, wherein, A second stirring mixing tank (22b) is also provided between the multi-channel mixer (24) and the storage tank for secondary mixing of the second initiator mixture.

11. The premixing method according to claim 1, wherein, The microchannel multichannel mixer (41) has a jacket outside the first housing (46) for external heat exchange medium to flow and exchange heat with the microchannel multichannel mixer (41); or The impact-type multi-channel mixer (51) has a jacket outside the second housing (55) for external heat exchange medium to flow and exchange heat with the impact-type multi-channel mixer (51).

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