CN114014962B

CN114014962B - Organic peroxide microemulsion type initiator and preparation method thereof

Info

Publication number: CN114014962B
Application number: CN202111395619.3A
Authority: CN
Inventors: 闫世友; 马豪杰; 魏琪琪; 牛宝定; 孙嘉成
Original assignee: Urumqi City Huatailong Chemical Auxiliaries Co ltd
Current assignee: Urumqi City Huatailong Chemical Auxiliaries Co ltd
Priority date: 2021-11-23
Filing date: 2021-11-23
Publication date: 2023-04-07
Anticipated expiration: 2041-11-23
Also published as: CN114014962A

Abstract

The invention discloses an organic peroxide microemulsion type initiator and a preparation method thereof, belonging to the technical field of initiator preparation. The initiator comprises the following components in percentage by mass: 0.5-2% of main emulsifier, 5-10% of co-emulsifier, 2-5% of main dispersant, 0.1-0.2% of co-dispersant, 10-30% of antifreeze agent, 30-60% of oil phase and the balance of deionized water. The preparation method comprises the steps of mixing the oil phase with a certain amount of auxiliary materials such as a main emulsifier, an auxiliary emulsifier, a main dispersing agent, an auxiliary dispersing agent, a solvent and the like by the process of the invention, and then homogenizing and emulsifying to obtain a semitransparent uniform stable microemulsion product. The particle size of the initiator product is lower than 0.08 micrometer, the emulsion stability is high, and when the initiator product is used for PVC polymerization synthesis, the initiation efficiency can be improved, and the stable and efficient production of PVC is ensured.

Description

Organic peroxide microemulsion type initiator and preparation method thereof

Technical Field

The invention belongs to the technical field of initiator preparation, and particularly relates to an organic peroxide microemulsion type initiator and a preparation method thereof.

Background

PVC is one of general plastics with the largest yield in the world, and has wide application in the aspects of building materials, industrial products, daily necessities, floor leathers, floor tiles, artificial leather, pipes, wires and cables, packaging films, bottles, foaming materials, sealing materials, fibers and the like. More than 75 percent of PVC is produced by a suspension polymerization method, and the initiator used in the production is usually a mixture of two or three emulsion type initiator single products.

The initiator adopted in the production of PVC at present is usually organic peroxide, and the organic peroxide liquid initiator is mainly divided into a solvent type and an emulsion type, and is respectively applied according to different application polymerization types, the solvent type is generally applied to bulk polymerization, the dispersion requirement is avoided, the polymerization efficiency is high, the emulsion type initiator is usually applied to suspension polymerization, and the particle size of the dispersed phase of the initiator in an emulsion type product is small, so that the initiator can be uniformly dispersed in a polymerization system quickly and effectively to improve the initiation efficiency and the stability of the initiation polymerization process. However, the particle size of the current common emulsion initiator can only reach about 2 microns, the dispersion capability in a polymer system is limited, and the further improvement of the initiation efficiency is limited, so that a microemulsion initiator with a lower particle size is urgently needed, and the stable production of PVC is realized.

Through search, the Chinese patent application numbers are: 202011002383.8, as filed: the invention is named as follows in 9 month and 22 days in 2020: a polyvinyl chloride resin composite emulsion initiator and a preparation method thereof. The composite emulsion type initiator disclosed in the application is stable emulsion prepared from two or more than two pure initiator products according to a proportion, and comprises the following components in percentage by mass: pure product of the composite initiator: 40 to 65 percent; and (3) glue retention agent: 0.2 to 5 percent; dispersing agent: 0.8 to 13 percent; an antifreeze agent: 12 to 18 percent; emulsifier: 0.1 to 3 percent. The preparation method comprises the following steps: sequentially adding the dispersant, the distilled water and the emulsifier into a container according to the mixture ratio, stirring, then adding the antifreeze, and stirring again; controlling the temperature to be-5-2 ℃, adding a pure product of the composite initiator, and stirring; adding the adhesive retaining agent, stirring, homogenizing by an ultrasonic emulsification device, and placing in a cold storage. The application aims to improve the stability after mixing when two or more than two pure initiators are compounded for use, so that the stable production of the PVC resin is ensured, but the particle size of the emulsion of the product of the application can be 0.2 to 3.0 microns, and the emulsion still needs to be further improved and improved, so that the stability of the product is further improved, and the storage time of the product is prolonged.

Disclosure of Invention

1. Problems to be solved

The invention aims to overcome the defects that the traditional emulsion type organic peroxide initiator is difficult to reduce the particle size (usually about 2 microns), so that the traditional emulsion type organic peroxide initiator is poor in system stability and short in storage time on one hand, and is poor in initiation efficiency when a polymer system is used on the other hand, and provides an organic peroxide microemulsion type initiator and a preparation method thereof. The technical scheme of the invention can effectively solve the problems and effectively reduce the particle size of the emulsion, thereby improving the stability of the obtained emulsion product, and when the emulsion is used for PVC polymerization synthesis, the initiation efficiency can be improved, and the stable and efficient production of PVC can be ensured.

2. Technical scheme

In order to solve the problems, the technical scheme adopted by the invention is as follows:

the invention relates to an organic peroxide microemulsion type initiator, which comprises the following components in percentage by mass: 0.5-2% of a main emulsifier, 5-10% of a co-emulsifier, 2-5% of a main dispersant, 0.1-0.2% of a co-dispersant, 10-30% of an antifreeze agent, 30-60% of an oil phase and the balance of deionized water.

Furthermore, the oil phase is selected from any one of cumyl peroxyneodecanoate, tert-butyl peroxyneodecanoate, 2-ethylhexyl peroxydicarbonate and 3,5,5 trimethylhexanoyl peroxydicarbonate.

Further, the main emulsifier is selected from polyoxyethylene nonyl phenyl ether.

Further, the coemulsifier is selected from n-butanol.

Further, the main dispersing agent is polyvinyl alcohol with alcoholysis degree of 80%.

Furthermore, the dispersion aid is sodium carboxymethyl cellulose.

Further, the antifreeze agent is selected from methanol.

The invention relates to a preparation method of the organic peroxide microemulsion type initiator, which comprises the following two steps:

the first step is as follows: adding a main emulsifier, a main dispersing agent, an auxiliary dispersing agent, an antifreeze agent and deionized water into a reaction kettle, mixing and stirring;

the second step is that: and (3) preparing emulsion, namely mixing the product synthesized in the first step with an oil phase, stirring, shearing, and dripping the auxiliary emulsifier to complete the preparation.

Furthermore, in the first step, the main emulsifier, the main dispersant, the auxiliary dispersant, the antifreeze and the deionized water are added into a reaction kettle to be mixed and stirred for 10min, and the temperature in the reaction kettle is required to be controlled below 0 ℃.

Furthermore, in the second step, the product synthesized in the first step is firstly put into an oil phase emulsifying kettle, and stirred and sheared for 30min; and then, slowly dripping the co-emulsifier into the kettle, stopping dripping when the appearance of the materials in the kettle is changed from milky white to semitransparent, and continuously shearing for 10min to finish the preparation.

3. Advantageous effects

Compared with the prior art, the invention has the beneficial effects that:

(1) According to the organic peroxide microemulsion initiator, the component composition and the proportion thereof are optimally designed, so that the organic peroxide microemulsion initiator with the emulsion particle size reduced to about 80 nanometers is obtained, compared with the traditional emulsion initiator, the organic peroxide microemulsion initiator can be rapidly dispersed in a suspension polymerization system to initiate polymerization and keep the heat release in the polymerization process stable, meanwhile, compared with the traditional emulsion initiator, the addition amount of the organic peroxide microemulsion initiator can be reduced by one third, the suspension polymerization reaction time can be reduced by one third, the process cost is reduced, and the reaction efficiency is greatly improved.

(2) The organic peroxide microemulsion initiator adopts a composite emulsifying system and a composite dispersing system, can prepare microemulsion cumyl peroxyneodecanoate products with different contents in a range of 30-60% by selecting and proportioning the formula of a main initiator, an auxiliary initiator, a main dispersing agent and an auxiliary dispersing agent, and can meet the requirements of different suspension polymerization processes.

(3) The organic peroxide microemulsion type initiator provided by the invention has the advantages that the main emulsifier is selected from nonylphenol polyoxyethylene ether which is soluble in water and oil, the HLB value is 14.5, the initiator belongs to a high-efficiency O/W type emulsifier, the auxiliary emulsifier is selected from n-butyl alcohol, the n-butyl alcohol is used in a minimum amount, and the microemulsion effect is the best.

(4) The preparation method of the organic peroxide microemulsion initiator comprises the steps of optimizing the components and the proportion of the components, optimally designing the whole process, and particularly adopting a microemulsion preparation process, wherein a main emulsifier dispersant and an oil phase are mixed and then pre-emulsified, and then an auxiliary emulsifier n-butyl alcohol is added to match with a shearing process for post-emulsification, so that the prepared microemulsion product has uniform and stable particle size, the stability of the emulsion can be effectively improved, and the using effect of the emulsion is ensured.

(5) Compared with the traditional emulsion type product, the product produced by adopting the process disclosed by the invention can effectively reduce the addition amount of the organic peroxide microemulsion type initiator, so that the production cost can be reduced, and the economic benefit of an enterprise can be improved. Meanwhile, under the condition of the same addition, the polymerization time of SG-5 type PVC can be reduced by 40-50min, the apparent density of PVC can be increased by 0.02g/ml to 0.54g/ml or more, the screen residue (0.25 mm screen is less than or equal to 0.3 percent, 0.063mm screen is more than or equal to 99.5 percent), and the number of fish eyes is as low as 3/400 cm ² Greatly improving the PVC production efficiency and the PVC product quality.

Drawings

FIG. 1 shows the results of performance test indexes of products obtained in examples of the present invention and comparative examples;

FIG. 2 shows verification data of a polymerization process for polyvinyl chloride type 5 carried out on 20m polymerization reactors for products obtained in examples according to the invention and comparative examples.

Detailed Description

The invention relates to an organic peroxide microemulsion initiator, which comprises the following components in percentage by mass: 0.5-2% of main emulsifier, 5-10% of co-emulsifier, 2-5% of main dispersant, 0.1-0.2% of co-dispersant, 10-30% of antifreeze agent, 30-60% of oil phase and the balance of deionized water. Specifically, the oil phase is selected from any one of cumyl peroxyneodecanoate (with the content of 80% -85%), tert-butyl peroxyneodecanoate (with the content of 95% -100%), 2-ethylhexyl peroxydicarbonate (with the content of 95% -100%), and 3,5,5 trimethylhexanoyl peroxydicarbonate (with the content of 95% -100%); the main emulsifier is selected from polyoxyethylene nonyl phenyl ether. The coemulsifier is selected from n-butyl alcohol. The main dispersing agent is polyvinyl alcohol with alcoholysis degree of 80%. The auxiliary dispersing agent is sodium carboxymethyl cellulose. The antifreeze agent is selected from methanol. According to the invention, by adopting the formula selection of the main initiator and the auxiliary initiator and the formula selection of the main dispersant and the auxiliary dispersant, and matching with the microemulsion preparation process created by the invention, microemulsion type initiator products with different contents in the range of 30-60% can be prepared. The main emulsifier is OP-10 which is soluble in water and oil, the HLB value is 14.5, the main emulsifier belongs to a high-efficiency O/W type emulsifier, and the auxiliary emulsifier is preferably selected from n-butyl alcohol through experiments, so that the dosage is the least and the micro-emulsification effect is the best. And simultaneously, a composite emulsion system is matched, a composite dispersion system is optimized, and the composite emulsion system and the composite dispersion system can be used for preparing microemulsion type initiator products with different contents in a range of 30-60% by adjusting different adding amounts, so that the requirements of different suspension polymerization processes can be met.

It should also be noted that the traditional initiator emulsion system is prepared by mixing and emulsifying an emulsifier, a dispersant, an antifreeze and an oil phase, the emulsion prepared by the method is white and opaque in appearance, the particle size of the emulsion is about 2 microns, and the dispersion capability in the polymer system is limited, thereby limiting the further improvement of the initiation efficiency. In order to reduce the particle size of the emulsion, on the basis of the use of the traditional oil-in-water type emulsifier, the invention can achieve the purposes that the particle size of the emulsion is less than 0.08 micrometer, the particle size distribution is uniform, agglomeration and delamination do not occur, the emulsion stability is good, more initiator particles exist in the initiation of a polymerization chain due to the smaller particle size of a disperse phase, the collision probability of the initiator and monomer molecules is greatly increased, the 'cage effect' of the initiator generated due to the overlarge particle size is reduced, the polymerization reaction can be efficiently and rapidly initiated in the initial stage of polymerization, the whole polymerization reaction time is reduced, the heat release in the whole polymerization reaction process is stable and easy to control, the polymerization degree distribution range and the branched chain content of PVC can be reduced, and the suspension polymerization efficiency and the polymer product index can be greatly improved when the emulsion is put into use.

In addition, the n-butyl alcohol is added into the system, so that the surface energy of oil phase liquid drops in the system can be effectively reduced, the process is matched, the n-butyl alcohol is controlled to be slowly added in the emulsification and shearing process, the particle size of the emulsion can be ensured to be slowly and stably reduced from about 2 micrometers, and the addition amount of the co-emulsifier can be determined according to the change of the appearance transparency in the production process. Meanwhile, the auxiliary dispersing agent carboxymethyl cellulose is introduced into the system, and the addition of the carboxymethyl cellulose can improve the viscosity of a continuous phase in an emulsion system, so that the merging speed of emulsion particles continuously generated in the process of preparing the microemulsion is slowed down along with the shearing process, the preparation difficulty of the microemulsion system is reduced, the adhesive retaining capacity is greatly improved due to the improvement of the viscosity in the prepared microemulsion system, a stable microemulsion state can be kept for a long time, and the emulsion stability can be stable and not delaminated for more than 24 months.

The invention also provides a preparation method of the product, which mainly comprises the following two steps:

(1) Firstly, adding a main emulsifier, a main dispersing agent, an auxiliary dispersing agent, an antifreeze agent and deionized water into a reaction kettle, mixing, and stirring for 10min, wherein the temperature in the reaction kettle is required to be controlled below 0 ℃.

(2) Secondly, putting the product synthesized in the first step into an oil phase emulsifying kettle, and stirring and shearing for 30min; then, the auxiliary emulsifier is slowly dripped into the kettle, the dripping is stopped after the appearance of the materials in the kettle is rapidly changed from milk white to semitransparent, and the preparation is finished after the materials are continuously sheared for 10 min.

The invention optimizes the component types and the proportion of the product, optimizes the whole process, particularly adopts a microemulsion preparation process, pre-emulsifies the mixture of the main emulsifier dispersant and the oil phase by controlling the temperature and the stirring time, and then adds the auxiliary emulsifier n-butyl alcohol to match with the shearing process for post-emulsification, so that the prepared microemulsion product has uniform and stable grain diameter, thereby effectively improving the stability of the emulsion and ensuring the using effect.

The invention is further described with reference to specific examples.

Example 1

The formula is as follows: OP-10%, n-butyl alcohol 6%, PVA-4788 5%, CMC0.2%, methanol 20%, cumyl peroxyneodecanoate 32%, and the balance of deionized water.

The preparation method comprises the steps of adding OP-10, PVA-4788, CMC0.2%, methanol and deionized water into a reaction kettle, mixing, starting stirring, controlling the temperature below 0 ℃, stirring for 10min, then moving into an oil phase emulsifying kettle, stirring and shearing for 30min, then starting to slowly dropwise add n-butyl alcohol, stopping dropwise adding after the appearance of materials in the kettle is rapidly changed from milky white to semitransparent, continuing to shear for 10min, and then completing the preparation, thus obtaining the microemulsion type initiator product with the content of 30%.

Example 2

The formula is as follows: OP-10%, n-butanol 8%, PVA-4788 4%, CMC0.2%, methanol 20%, cumyl peroxyneodecanoate 60%, and the balance of deionized water.

The preparation method comprises the steps of adding OP-10, PVA-4788, CMC0.2%, methanol and deionized water into a reaction kettle, mixing, starting stirring, controlling the temperature below 0 ℃, stirring for 10min, then transferring into an oil phase emulsification kettle, stirring and shearing for 30min, then starting to slowly dropwise add n-butyl alcohol, stopping dropwise adding after the appearance of materials in the kettle is rapidly changed from milky white to semitransparent, continuing to shear for 10min, and then completing preparation to obtain the microemulsion type initiator product with the content of 50%.

Example 3

The formula is as follows: OP-10%, n-butanol 8%, PVA-4788 4%, CMC0.2%, methanol 20%, tert-butyl peroxyneodecanoate 52%, and the balance of deionized water.

Example 4

The formula is as follows: OP-10%, n-butanol 8%, PVA-4788 4%, CMC0.2%, methanol 20%, 2-ethylhexyl peroxydicarbonate 52%, and the balance of deionized water.

Example 5

The formula is as follows: OP-10.5%, n-butanol 10%, PVA-4788 2%, CMC0.2%, methanol 30%, peroxydicarbonate-3,5,5 trimethyl hexanoyl 52%, and the balance of deionized water.

The preparation method comprises the steps of adding OP-10, PVA-4788, CMC0.2%, methanol and deionized water into a reaction kettle, mixing, starting stirring, controlling the temperature below 0 ℃, stirring for 10min, then moving into an oil phase emulsifying kettle, stirring and shearing for 30min, then starting to slowly dropwise add n-butyl alcohol, stopping dropwise adding after the appearance of materials in the kettle is rapidly changed from milky white to semitransparent, continuing to shear for 10min, and then completing the preparation, thus obtaining the microemulsion type initiator product with the content of 50%.

Example 6

The formula is as follows: OP-10%, n-butanol 5%, PVA-4788 5%, CMC 0.1%, methanol 10%, cumyl peroxyneodecanoate 60%, and the balance deionized water.

The preparation method comprises the steps of adding OP-10, PVA-4788, CMC0.2%, methanol and deionized water into a reaction kettle, mixing, starting stirring, controlling the temperature below 0 ℃, stirring for 10min, then moving into an oil phase emulsifying kettle, stirring and shearing for 30min, then starting to slowly dropwise add n-butyl alcohol, stopping dropwise adding after the appearance of materials in the kettle is rapidly changed from milky white to semitransparent, continuing to shear for 10min, and then completing the preparation, thus obtaining the microemulsion type initiator product with the content of 60%.

Comparative example 1

The formula is as follows: OP-10.3%, n-butanol 8%, PVA-4788%, CMC0.2%, methanol 20%, cumyl peroxyneodecanoate 62%, and the balance deionized water.

Comparative example 2

The formula is as follows: OP-10.0%, n-butanol 8%, PVA-4788%, CMC0.2%, methanol 20%, cumyl peroxyneodecanoate 62%, and the balance deionized water.

The preparation method comprises the steps of adding OP-10, n-butyl alcohol, PVA-4788, CMC0.2%, methanol and deionized water into a reaction kettle, mixing, starting stirring, controlling the temperature below 0 ℃, moving into an oil phase emulsifying kettle after stirring for 10min, starting shearing after stirring for 10min, and completing preparation after shearing for 60min to obtain a microemulsion type initiator product with the content of 50%.

Comparative example 3

The formula is as follows: OP-10.0%, n-butanol 8%, PVA-4788%, CMC0.2%, methanol 20%, cumyl peroxyneodecanoate 70%, and the balance deionized water.

The preparation method comprises the steps of adding OP-10, n-butyl alcohol, PVA-4788, CMC0.2%, methanol and deionized water into a reaction kettle, mixing, starting stirring, controlling the temperature below 0 ℃, moving into an oil phase emulsifying kettle after stirring for 10min, starting shearing after stirring for 10min, and completing preparation after shearing for 60min to obtain a microemulsion type initiator product with the content of 60%.

Comparative example 4

The formula is as follows: OP-10.0%, n-butanol 8%, PVA-4788%, methanol 20%, cumyl peroxyneodecanoate 62%, and the balance deionized water.

The preparation method comprises the steps of adding OP-10, PVA-4788, methanol and deionized water into a reaction kettle, mixing, starting stirring, controlling the temperature below 0 ℃, stirring for 10min, moving into an oil phase emulsifying kettle, stirring and shearing for 30min, then starting to slowly dropwise add n-butyl alcohol, stopping dropwise adding after the appearance of materials in the kettle is rapidly changed from milky white to semitransparent, continuing to shear for 10min, and completing preparation to obtain a microemulsion type initiator product with the content of 50%.

Comparative example 5

The formula is as follows: OP-10%, n-butanol 8%, CMC0.2%, methanol 20%, cumyl peroxyneodecanoate 62%, and the balance of deionized water.

The preparation method comprises the steps of adding OP-10, CMC (sodium carboxymethyl cellulose) 0.2%, methanol and deionized water into a reaction kettle, mixing, starting stirring, controlling the temperature below 0 ℃, stirring for 10min, moving into an oil phase emulsifying kettle, stirring and shearing for 30min, then starting to slowly dropwise add n-butyl alcohol, stopping dropwise adding when the appearance of materials in the kettle is rapidly changed from milky white to semitransparent, continuing to shear for 10min, and completing preparation to obtain a microemulsion type initiator product with the content of 50%.

The products obtained in the above examples and comparative examples were tested, including (1) the content, appearance and particle size of the emulsion obtained by the preparation; (2) The stability of the final emulsion product was tested and the results are shown in figure 1. According to the data in fig. 1, the components and the proportion thereof can effectively reduce the particle size of the emulsion and improve the stability of the emulsion of the product, and the stability can reach more than 24 months and is stable without layering.

Verification of polyvinyl chloride type 5 polymerisation process was carried out on 20m polymerisation vessels harvesting the products obtained in the above examples and comparative examples, the verification data being shown in fig. 2. According to the data in figure 2, on the premise of the same adding amount, the components and the proportion thereof are selected, the PVC polymerization time can be reduced by 40-50min, the apparent density of PVC can be improved by 0.02g/ml to 0.54g/ml and above, screen residues (0.25 mm screen is less than or equal to 0.3 percent, 0.063mm screen is more than or equal to 99.5 percent), and the number of fish eyes is reduced to within 3 (each 400 cm) ² ）。

Claims

1. An organic peroxide microemulsion type initiator is characterized by comprising the following components in percentage by mass: 0.5-2% of main emulsifier, 5-10% of co-emulsifier, 2-5% of main dispersant, 0.1-0.2% of co-dispersant, 10-30% of antifreeze agent, 30-60% of oil phase and the balance of deionized water;

the oil phase is selected from any one of cumyl peroxyneodecanoate, tert-butyl peroxyneodecanoate and 2-ethylhexyl peroxydicarbonate; the main emulsifier is OP-10; the auxiliary emulsifier is selected from n-butyl alcohol; the main dispersing agent is selected from PVA-4788; the auxiliary dispersing agent is sodium carboxymethyl cellulose; the antifreeze is selected from methanol;

the preparation method comprises two steps:

the second step is that: and (3) emulsion preparation, namely mixing the product synthesized in the first step with an oil phase, stirring, shearing, and dripping a co-emulsifier to finish the preparation.

2. A process for the preparation of an organic peroxy microemulsion initiator according to claim 1, comprising two steps:

3. The method for preparing an organic peroxy microemulsion initiator according to claim 2, wherein: in the first step, a main emulsifier, a main dispersing agent, an auxiliary dispersing agent, an antifreeze agent and deionized water are added into a reaction kettle and mixed, and the mixture is stirred for 10min, wherein the temperature in the reaction kettle is required to be controlled below 0 ℃.

4. The method for preparing an organic peroxy microemulsion initiator according to claim 3, wherein: in the second step, the product synthesized in the first step is put into an oil phase emulsifying kettle, and stirred and sheared for 30min; then, the auxiliary emulsifier is slowly dripped into the kettle, the dripping is stopped after the appearance of the materials in the kettle is rapidly changed from milk white to semitransparent, and the preparation is finished after the materials are continuously sheared for 10 min.