CN107459595B - Preparation method of CPVC resin by aqueous phase suspension method - Google Patents
Preparation method of CPVC resin by aqueous phase suspension method Download PDFInfo
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Abstract
A preparation method of CPVC resin by a water phase suspension method belongs to the technical field of chemical raw materials. The preparation method is characterized by comprising the following preparation steps: uniformly spraying a polyol aqueous solution on the surface of the PVC resin by using a spraying device; and uniformly suspending the PVC resin sprayed with the polyol in a deionized water polymerization kettle, adding an initiator, introducing chlorine, carrying out chlorination reaction, adding a chain terminator after chlorine introduction is finished, stopping the reaction, washing and drying to obtain the catalyst. Aiming at the characteristics of the CPVC resin aqueous phase suspension method production process, the invention abandons the dispersing agent, carries out surface activation treatment on the PVC resin by using the polyhydric alcohol, and then carries out chlorination reaction, and the prepared CPVC resin has high chlorine content and aging whiteness, good stability, easy and uniform plasticization and good processability. The product can be widely used as a chemical raw material for manufacturing various products such as pipes, plates, profiles, sheets, injection molding parts, foam materials and the like.
Description
Technical Field
A preparation method of CPVC resin by a water phase suspension method belongs to the technical field of chemical raw materials.
Background
CPVC resin is an important polymer material, and there are three main methods for producing CPVC, depending on the dispersion medium: the solvent method, the solid phase method and the aqueous phase suspension method are influenced by environmental protection, energy consumption, process and the like, the solvent method is basically eliminated, the domestic CPVC resin has two production methods of the solid phase method and the aqueous phase suspension method at present, the aqueous phase suspension method is mainly used, and the international famous CPVC production enterprises mainly use the method. The traditional CPVC resin production process by the aqueous phase suspension method comprises the following specific steps of suspending PVC resin in water or hydrochloric acid solution, adding an initiator and a dispersing agent, stirring to enable the PVC resin to be suspended in an aqueous phase medium, replacing air in a reaction kettle with nitrogen, vacuumizing, heating the reaction kettle, introducing chlorine gas, heating to 80-110 ℃, keeping the pressure in the kettle at 0.2-0.6 MPa, controlling the chlorine introduction speed, carrying out uniform chlorination, stopping introducing the chlorine gas after reaching the specified chlorine introduction amount, adding a terminator, terminating the reaction, and obtaining a CPVC resin product by alkali washing, water washing, centrifuging and drying.
In the existing aqueous suspension production technology of the CPVC resin, one or more of dispersing agents such as silica sol, hydroxypropyl methylcellulose, polyvinyl alcohol and the like with similar functions to PVC resin involucra are required to be added to enable the PVC resin to be uniformly suspended in an aqueous medium. The addition of the dispersant can partially graft or adsorb on the surface of the resin particles in chlorination reaction to form a resin coating, so that the resin coating is thickened and dense. On one hand, the deep chlorination and the uniformity of chlorination of the resin are hindered, so that the CPVC resin structure has defects; on the other hand, the absorption capacity of the CPVC resin auxiliary agent is weakened, so that the CPVC resin has poor plasticizing uniformity, difficult processing, rough and lusterless products and insufficient physical and mechanical properties.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: overcomes the defects of the prior art, and provides a preparation method of CPVC resin by an aqueous phase suspension method, which has few involucra and is easy to plasticize.
The technical scheme adopted by the invention for solving the technical problems is as follows: the preparation method of the CPVC resin by the aqueous phase suspension method is characterized by comprising the following preparation steps:
1) preparing 10-70% of polyhydric alcohol aqueous solution by mass percent from polyhydric alcohol;
2) uniformly spraying a polyol aqueous solution on the surface of the PVC resin by using a spraying device; the using amount of the polyalcohol is 0.4 to 1 percent of the mass of the PVC resin;
3) uniformly suspending PVC resin sprayed with polyhydric alcohol in a deionized water polymerization kettle under the stirring action, wherein the mass of the PVC resin added in the polymerization kettle is 10-25% of that of the deionized water;
4) adding an initiator into the PVC suspension in the polymerization kettle;
5) replacing air in the reaction kettle with nitrogen or chlorine, heating the reaction kettle, introducing chlorine at the same time, starting chlorination reaction, controlling the temperature of the reaction kettle to be 90-110 ℃, and keeping the pressure of the reaction kettle at 0.2-0.4 MPa;
6) after chlorine introduction is finished, adding a chain terminator, stopping reaction, washing and drying to obtain the catalyst;
the boiling point of the polyol is not less than 200 ℃, the flash point is not less than 150 ℃, and the polyol can be mutually soluble with water in any ratio.
Aiming at the characteristics of the CPVC resin aqueous phase suspension method production process, the dispersing agent is abandoned, the polyol is firstly utilized to carry out surface activation treatment on the PVC resin, and then chlorination reaction is carried out, so that the PVC resin can be quickly and uniformly suspended in the aqueous phase, the polyol can be quickly dissolved in the suspended aqueous phase, the resin does not form a film, and the absorption capacity of the CPVC resin auxiliary agent is not influenced, thereby preparing the CPVC resin with less film, good thermal stability, easy plasticization and high comprehensive performance. The used polyalcohol is environment-friendly and nontoxic, has a high boiling point and a high flash point, is grafted or adsorbed on the particle surface of the CPVC resin after chlorination reaction, and has a certain internal lubricating effect besides the surface activating effect.
Preferably, the mass part of the polyhydric alcohol in the polyhydric alcohol aqueous solution is 20-50%. The mass fraction of the polyol mainly affects the uniformity on the surface of the PVC resin when sprayed. Thereby influencing the uniform dispersion rate and effect of the PVC resin in the deionized water. Within the preferred range, the PVC resin can be suspended in the aqueous solution more rapidly and uniformly.
Preferably, the polyhydric alcohol is glycerol or butanediol. The glycerol and the butanediol can be well attached to the surface of the PVC resin after being sprayed, so that a relatively ideal surface activation effect is achieved, and the dispersion effect is enhanced.
Preferably, the polyol is glycerol. The glycerol is the polyalcohol with the best use effect, the water solution of the glycerol is easy to uniformly spray by using a spraying device, the surface tension of the glycerol can ensure that the glycerol is spontaneously and uniformly dispersed on the surface of the PVC resin to completely coat the PVC resin, and finally the PVC resin is more uniformly suspended in the water solution.
Preferably, the initiator is used in an amount of 0.01 to 1.0% by weight of the PVC resin.
Preferably, the initiator is one or a mixture of two or three of azodiisoheptonitrile, dibenzoyl peroxide and peroxydicarbonate in any proportion.
The amount and type of initiator selected primarily affects the rate of initiation of the reaction, and improper initiator selection can result in uneven chlorination reactions.
Preferably, the chain terminator is acetonide thiosemicarbazone or diethyl hydroxylamine.
Preferably, the PVC resin is chloridizable PVC resin with the polymerization degree of 600-1000.
Compared with the prior art, the preparation method of the CPVC resin by the aqueous phase suspension method has the beneficial effects that: aiming at the characteristics of the CPVC resin aqueous phase suspension method production process, the dispersing agent is abandoned, the polyol is firstly utilized to carry out surface activation treatment on the PVC resin, and then chlorination reaction is carried out, so that the PVC resin can be quickly and uniformly suspended in the aqueous phase, the polyol can be quickly dissolved in the suspended aqueous phase, the resin does not form a film, and the absorption capacity of the CPVC resin auxiliary agent is not influenced, thereby preparing the CPVC resin with less film, good thermal stability, easy plasticization and high comprehensive performance. The used polyalcohol is environment-friendly and nontoxic, has a high boiling point and a high flash point, is grafted or adsorbed on the particle surface of the CPVC resin after chlorination reaction, and has a certain internal lubricating effect besides the surface activating effect. The prepared CPVC resin has high chlorine content and aging whiteness, good stability, easy and uniform plasticization and good processability. The product can be widely used as a chemical raw material for manufacturing various products such as pipes, plates, profiles, sheets, injection molding parts, foam materials and the like.
Detailed Description
The method for making an anti-clog grinding tool of the present invention will now be described in detail with reference to the following examples, of which example 1 is the best example.
Example 1
Adding 80kg of deionized water into a 100L chlorination reaction kettle, uniformly spraying 167g of glycerol aqueous solution with the mass part ratio of 30% on the surface of 10kg of special chloridizable PVC resin QS-C65, then adding the chlorination reaction kettle, starting a stirring device, quickly and uniformly suspending the PVC resin in a water phase, adding 125g of peroxydicarbonate with the concentration of 40%, discharging the air in the kettle by using chlorine gas, heating the reaction kettle, slowly introducing the chlorine gas, accelerating the chlorination reaction when the temperature of the reaction kettle reaches about 85 ℃, controlling the temperature of the reaction kettle to be 95 ℃, introducing the chlorine at the speed of 50g/min, keeping the pressure of the reaction kettle at 0.2-0.4MPa, stopping introducing the chlorine when the chlorine introducing amount reaches 6.8kg, adding 200g of a terminator with the concentration of 20%, vacuumizing after 10 minutes, discharging residual chlorine, cooling the polymerization kettle to 50 ℃, carrying out alkali washing, water washing, centrifuging and drying on a reaction product to obtain the high-quality CPVC-1 resin.
Example 2
Adding 80kg of deionized water into a 100L chlorination reaction kettle, uniformly spraying 600g of glycerol aqueous solution with the mass part ratio of 10% on the surface of 10kg of special chloridizable PVC resin QS-C65, then adding the chlorination reaction kettle, starting a stirring device, quickly and uniformly suspending the PVC resin in a water phase, adding 150g of 40% peroxydicarbonate, discharging the air in the kettle by using chlorine gas, heating the reaction kettle, slowly introducing the chlorine gas, accelerating the chlorination reaction when the temperature of the reaction kettle reaches about 85 ℃, controlling the temperature of the reaction kettle to be 100 ℃, introducing the chlorine at a speed of 50g/min, keeping the pressure of the reaction kettle to be 0.2-0.4MPa, stopping introducing the chlorine when the chlorine introducing amount reaches 6.8kg, adding 200g of 20% terminator diethyl hydroxylamine, vacuumizing after 10 minutes, discharging residual chlorine, cooling the polymerization kettle to 50 ℃, carrying out alkaline washing, water washing, centrifuging and drying on a reaction product, thereby obtaining the high-quality CPVC-2 resin.
Example 3
Adding 80kg of deionized water into a 100L chlorination reaction kettle, uniformly spraying 129g of glycerol aqueous solution with the mass part ratio of 70% on the surface of 15kg of special chloridizable PVC resin QS-C65, then adding the chlorination reaction kettle, starting a stirring device, quickly and uniformly suspending the PVC resin in a water phase, adding 150g of 40% peroxydicarbonate, discharging the air in the kettle by using chlorine gas, heating the reaction kettle, slowly introducing the chlorine gas, accelerating the chlorination reaction when the temperature of the reaction kettle reaches about 85 ℃, controlling the temperature of the reaction kettle to be 100 ℃, introducing the chlorine at a speed of 50g/min, keeping the pressure of the reaction kettle to be 0.2-0.4MPa, stopping introducing the chlorine when the chlorine introducing amount reaches 6.8kg, adding 200g of 20% terminator diethyl hydroxylamine, vacuumizing after 10 minutes, discharging residual chlorine, cooling the polymerization kettle to 50 ℃, carrying out alkaline washing, water washing, centrifuging and drying on a reaction product, thereby obtaining the high-quality CPVC-3 resin.
Example 4
Adding 80kg of deionized water into a 100L chlorination reaction kettle, uniformly spraying 400g of glycerol aqueous solution with the mass part ratio of 20% on the surface of 20kg of special chloridizable PVC resin QS-C65, then adding the chlorination reaction kettle, starting a stirring device, quickly and uniformly suspending the PVC resin in a water phase, adding 5g of dibenzoyl peroxide with the concentration of 40%, discharging the air in the kettle by using chlorine gas, heating the reaction kettle, slowly introducing the chlorine gas, accelerating the chlorination reaction when the temperature of the reaction kettle reaches about 85 ℃, controlling the temperature of the reaction kettle to be 90 ℃, introducing the chlorine at the speed of 50g/min, keeping the pressure of the reaction kettle at 0.2-0.4MPa, stopping introducing the chlorine when the chlorine introducing amount reaches 6.8kg, adding 200g of a terminator with the concentration of 20%, vacuumizing after 10 minutes, discharging residual chlorine, cooling the polymerization kettle to 50 ℃, carrying out alkali washing, water washing, centrifuging and drying on a reaction product, thereby obtaining the high-quality CPVC-4 resin.
Example 5
Adding 80kg of deionized water into a 100L chlorination reaction kettle, uniformly spraying 160g of glycerol aqueous solution with the mass part ratio of 50% on the surface of 8kg of special resin QS-C60 for chloridizable PVC, then adding the chlorination reaction kettle, starting a stirring device, quickly and uniformly suspending PVC resin in a water phase, adding 200g of azodiisoheptonitrile with the concentration of 40%, discharging the air in the kettle by using chlorine gas, heating the reaction kettle, slowly introducing the chlorine gas, accelerating the chlorination reaction when the temperature of the reaction kettle reaches about 85 ℃, controlling the temperature of the reaction kettle to be 100 ℃, the chlorine introducing speed to be 50g/min, keeping the pressure of the reaction kettle to be 0.2-0.4MPa, stopping introducing the chlorine when the chlorine introducing amount reaches 6.8kg, adding 200g of terminator with the concentration of 20%, vacuumizing after 10 minutes, discharging residual chlorine, cooling the polymerization kettle to be 50 ℃, carrying out alkali washing, water washing, centrifuging and drying on a reaction product, thus obtaining the high-quality CPVC-5 resin.
Comparative example 1
80kg of deionized water, 10kg of special PVC resin QS-C60 capable of being chlorinated, 500g of polyvinyl alcohol with the concentration of 35% and 150g of peroxydicarbonate with the concentration of 40% are added into a chlorination reaction kettle of 100L, the mixture is stirred uniformly to enable the PVC resin to be suspended in a water phase, the temperature of the reaction kettle is raised after the air in the kettle is exhausted by using chlorine gas, the chlorine gas is slowly introduced into the reaction kettle, the chlorination reaction is accelerated when the temperature of the reaction kettle reaches about 85 ℃, the temperature of the reaction kettle is controlled to be 100 ℃, the chlorine introducing speed is controlled to be 50g/min, the pressure of the reaction kettle is kept to be 0.2-0.4MPa, the chlorine introducing is stopped when the chlorine introducing amount reaches 6.8kg, 200g of 20% terminator diethyl hydroxylamine with the concentration is added, the mixture is vacuumized after 10 minutes, the residual chlorine is discharged, the temperature of the polymerization kettle is reduced to 50 ℃, and the reaction product is.
Comparative example 2
Adding 80kg of deionized water into a 100L chlorination reaction kettle, uniformly spraying 500g of 35% polyvinyl alcohol on the surface of 8kg of chloridizable PVC special resin QS-C60, then adding into the chlorination reaction kettle, starting a stirring device, quickly and uniformly suspending PVC resin in a water phase, adding 200g of 40% azodiisoheptonitrile, discharging the air in the kettle by using chlorine gas, heating the reaction kettle, slowly introducing the chlorine gas, accelerating the chlorination reaction when the temperature of the reaction kettle reaches about 85 ℃, controlling the temperature of the reaction kettle to be 100 ℃, introducing the chlorine at a speed of 50g/min, keeping the pressure of the reaction kettle to be 0.2-0.4MPa, stopping introducing the chlorine when the chlorine introducing amount reaches 6.8kg, adding 200g of 20% terminator diethylhydroxylamine, vacuumizing after 10 minutes, discharging residual chlorine, cooling the polymerization kettle to 50 ℃, carrying out alkaline washing, water washing, centrifuging and drying on a reaction product, thereby obtaining the CPVC-7 resin with high quality.
Table 1 CPVC resin property test results obtained in each example and comparative example
Compared with the CPVC prepared by the conventional suspension method added with a dispersing agent, the CPVC prepared by the method has the advantages of high aging whiteness, good stability, easy and uniform plasticization and good processability. It can be seen from comparative example 2 that the effect of the present invention cannot be obtained by the process of the present invention using a conventional dispersant instead of polyol.
The foregoing is directed to preferred embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.
Claims (6)
1. A preparation method of CPVC resin by an aqueous phase suspension method is characterized by comprising the following preparation steps:
1) preparing 10-70% of polyhydric alcohol aqueous solution by mass percent from polyhydric alcohol;
2) uniformly spraying a polyol aqueous solution on the surface of the PVC resin by using a spraying device; the using amount of the polyalcohol is 0.4 to 1 percent of the mass of the PVC resin;
3) uniformly suspending PVC resin sprayed with polyhydric alcohol in a deionized water polymerization kettle under the stirring action, wherein the mass of the PVC resin added in the polymerization kettle is 10-25% of that of the deionized water;
4) adding an initiator into the PVC suspension in the polymerization kettle;
5) replacing air in the reaction kettle with nitrogen or chlorine, heating the reaction kettle, introducing chlorine at the same time, starting chlorination reaction, controlling the temperature of the reaction kettle to be 90-110 ℃, and keeping the pressure of the reaction kettle at 0.2-0.4 MPa;
6) after chlorine introduction is finished, adding a chain terminator, stopping reaction, washing and drying to obtain the catalyst;
the boiling point of the polyol is not less than 200 ℃, the flash point is not less than 150 ℃, and the polyol can be mutually soluble with water in any ratio;
the polyol is glycerol.
2. The method for preparing a CPVC resin by an aqueous phase suspension method as claimed in claim 1, wherein the method comprises the following steps: the mass portion of the polyhydric alcohol in the polyhydric alcohol aqueous solution is 20-50%.
3. The method for preparing a CPVC resin by an aqueous phase suspension method as claimed in claim 1, wherein the method comprises the following steps: the dosage of the initiator is 0.01-1.0% of the weight of the PVC resin.
4. The method for preparing a CPVC resin by an aqueous phase suspension method as claimed in claim 1, wherein the method comprises the following steps: the initiator is one or a mixture of two or three of azodiisoheptonitrile, dibenzoyl peroxide and peroxydicarbonate in any proportion.
5. The method for preparing a CPVC resin by an aqueous phase suspension method as claimed in claim 1, wherein the method comprises the following steps: the chain terminator is acetonide thiosemicarbazone or diethylhydroxylamine.
6. The method for preparing a CPVC resin by an aqueous phase suspension method as claimed in claim 1, wherein the method comprises the following steps: the PVC resin is chloridizable PVC resin with the polymerization degree of 600-1000.
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