CN114133471A

CN114133471A - Production method of super absorbent resin

Info

Publication number: CN114133471A
Application number: CN202210041877.XA
Authority: CN
Inventors: 刘峰; 路文学; 尹洪清; 赵梅梅; 张西标; 乔波; 王振华; 李滕; 刘莹; 杨澜; 吴永国; 吕传磊
Original assignee: Yankuang Coal Water Slurry Gasification And Coal Chemical Industry National Engineering Research Center Co ltd
Current assignee: Yankuang Coal Water Slurry Gasification And Coal Chemical Industry National Engineering Research Center Co ltd
Priority date: 2022-01-14
Filing date: 2022-01-14
Publication date: 2022-03-04
Anticipated expiration: 2042-01-14
Also published as: CN114133471B

Abstract

The invention provides a production method of super absorbent resin, which comprises the steps of firstly respectively preparing base liquid, neutralizing liquid and initiating liquid, and then sending the base liquid, the neutralizing liquid and the initiating liquid into a reactor to carry out primary polymerization reaction to obtain primary reaction liquid; and then, filtering the obtained primary reaction liquid through a filter plate at the outlet of the reactor, removing the filtrate into a flash evaporator, and keeping a solid product in the reactor as a raw material for the next step. Then, replenishing base liquid, neutralizing liquid and initiating liquid into the reactor, carrying out constant temperature treatment for a period of time at room temperature, and then heating for carrying out secondary polymerization reaction to obtain secondary reaction liquid; then continuing to heat the secondary reaction liquid for azeotropic dehydration and surface crosslinking to form steam and final reaction liquid; filtering the final reaction liquid to remove the filtrate into a flash evaporator, and keeping the solid product in the reactor; then, the solid product is discharged and dried to obtain the polyacrylate super absorbent resin. The production method can reduce energy consumption, improve production efficiency and ensure good performance.

Description

Production method of super absorbent resin

Technical Field

The invention relates to the field of water-absorbing materials, in particular to a production method of super absorbent resin.

Background

Super absorbent polymer (SAP for short) is a kind of new functional polymer material, can absorb several hundred times or even several thousand times of its own quality of water, and water retention capacity is very good, also dehydration or dehydration is very little under pressurizing, after the material after absorbing water is dried, the water absorption capacity can still resume, can use many times.

The types of the super absorbent resin are various, and the raw materials and the process method are different. The main types of the polyacrylate type polyvinyl alcohol copolymer are polyacrylate, polyvinyl alcohol and starch-bridged copolymer, and the polyacrylate type polyvinyl alcohol copolymer is mainly researched.

At present, domestic and foreign technologies are distinguished according to the type of a polymerization reaction solvent, the type of a polymerization device and the initiation temperature, and mainly comprise 4 technical routes, namely a reaction belt type continuous aqueous solution low-temperature initiation free radical polymerization process, a reaction belt type continuous aqueous solution high-temperature initiation free radical polymerization process, a reaction kettle type discontinuous aqueous solution free radical polymerization process and a reaction kettle type discontinuous reverse-phase free radical polymerization process.

For example, patent application 201280008185X discloses a method for producing a water-absorbent resin, in which after the completion of primary polymerization, the temperature is lowered to room temperature to precipitate a part of the surfactant and reduce the dispersion, and the temperature is raised again for polymerization after the unsaturated monomer aqueous solution is added again to the continuous phase. The above preparation method has the following problems: the repeated cooling and heating process causes a large amount of energy loss, and the production efficiency is low; secondly, the surfactant precipitated by cooling cannot be fixed and quantified, and the production is easy to cause instability.

Disclosure of Invention

In view of the above, the present invention aims to provide a method for producing a super absorbent resin. The production method provided by the invention can reduce energy loss, improve production efficiency and ensure good water absorption and retention capacity of the product.

The invention provides a production method of super absorbent resin, which utilizes production equipment to produce the super absorbent resin;

the production apparatus includes:

a reactor (V001); a filter plate is arranged at the discharge hole of the reactor (V001);

the discharge port of the mixer (H001) is communicated with the feed port of the reactor (V001);

a neutralizing liquid tank (V002) with a discharge port communicated with the feed port of the mixer (H001);

the discharge port is communicated with the feed port of the mixer (H001) to form an initiation liquid tank (V003);

the liquid inlet of the flash evaporator (T001) is communicated with the discharge hole of the reactor (V001);

the feeding hole of the dryer (G001) is communicated with the discharging hole of the reactor (V001);

a condenser (E001) with an air inlet communicated with the air outlet of the flash evaporator (T001); the condenser (E001) is also communicated with the gas outlet of the reactor (V001);

the production process comprises the following steps:

s1, feeding the hydrocarbon dispersion medium, the dispersing agent and the surfactant into a reactor (V001) for mixing and dissolving to obtain a base liquid;

s2, feeding the acrylic acid monomer and the alkali liquor into a neutralization liquid tank (V002) for neutralization reaction to obtain a neutralization liquid;

the alkali liquor is an alkaline solution formed by dissolving an alkaline substance in water;

s3, sending the initiator, the internal crosslinking agent and water into a priming liquid tank (V003) for mixing and dissolving to obtain a priming liquid;

s4, feeding the neutralization solution in the neutralization solution tank (V002) and the priming solution in the priming solution tank (V003) into a mixer (H001) for mixing and keeping the temperature constant to obtain a mixed solution 1;

s5, sending the mixed solution 1 to a reactor (V001) for primary polymerization reaction to obtain primary reaction solution; then, filtering the obtained primary reaction liquid through a filter plate at the outlet of the reactor (V001), removing the filtrate into a flash evaporator (T001), and keeping the solid product in the reactor (V001);

the filtrate entering the flash evaporator (T001) is subjected to flash separation, and the formed hydrocarbon dispersion medium vapor and the separation liquid are operated in two paths: the hydrocarbon dispersion medium steam goes upward and is discharged through a gas outlet and enters a condenser (E001) for condensation and recovery; the separated liquid is discharged from the flash evaporator (T001);

s6, supplementing a hydrocarbon dispersion medium, a dispersing agent and a surfactant into the reactor (V001); feeding the neutralization solution in the neutralization solution tank (V002) and the initiation solution in the initiation solution tank (V003) to the mixer (H001) again for mixing to obtain a mixed solution 2;

s7, sending the mixed solution 2 into a reactor (V001), carrying out constant temperature treatment at room temperature, and then heating for secondary polymerization reaction to obtain a secondary reaction solution; then continuing to heat the secondary reaction liquid for azeotropic dehydration and surface crosslinking to form steam and final reaction liquid; the steam and the final reaction liquid are operated in two paths: the steam is discharged from the air outlet and enters a condenser (E001) for condensation and recovery; filtering the final reaction liquid through a filter plate at the outlet of the reactor (V001), removing the filtrate into a flash evaporator (T001), and keeping the solid product in the reactor (V001); then, opening the filter plate, discharging the solid product and conveying the solid product into a dryer (G001) for drying, thereby obtaining the polyacrylate super absorbent resin;

the step S1, the step S2, and the step S3 are not limited in order.

Preferably, in the step S1, the temperature of the mixing and dissolving is 50 to 100 ℃;

after the mixing and dissolving, introducing inert gas into the reactor (V001) for deoxidizing;

in the step S2, the temperature of the neutralization reaction and the obtained neutralized liquid is controlled to be less than or equal to 45 ℃.

Preferably, in the step S2, the mass concentration of the alkali liquor is 28 wt% to 32 wt%;

the mass ratio of the acrylic acid monomer to the alkali liquor is (60-90) to (20-50).

Preferably, in the step S4, the constant temperature is constant to 30 to 80 ℃.

Preferably, in the step S5, the temperature of the first polymerization reaction is 60 to 80 ℃ and the time is 0.5 to 2 hours.

Preferably, in the step S6, the amount of the hydrocarbon dispersion medium to be supplemented is 1 to 1.5 times the amount of the filtrate removed in the flash evaporator (T001) in the step S5.

Preferably, in step S7:

the constant temperature treatment time is 0.5-1.5 h;

the temperature of the secondary polymerization reaction is 60-80 ℃, and the time is 0.5-3 h;

and continuously heating to 90-130 ℃.

Preferably, in the production facility:

the neutralization liquid tank (V002) is provided with a stirrer;

the initiating liquid tank (V003) is arranged and connected with a stirrer;

the reactor (V001) is provided with a stirrer;

in the production process:

in the step S1, mixing and dissolving are carried out under the stirring condition of 100-500 rpm;

in the step S2, carrying out a neutralization reaction under the stirring condition of 50-100 rpm;

in the step S3, mixing and dissolving are carried out under the stirring condition of 100-800 rpm;

in the step S5, carrying out primary polymerization reaction under the stirring condition of 200-600 rpm;

in the step S7, a secondary polymerization reaction is performed under a stirring condition of 200-600 rpm.

Preferably, in step S1:

the hydrocarbon dispersion medium is selected from one or more of n-hexane, n-heptane, cyclohexane and benzene;

the dispersing agent is selected from one or more of maleic anhydride-propylene copolymer, oxidized polyethylene and maleic anhydride-ethylene copolymer;

the surfactant is glycerin fatty acid ester and/or sucrose fatty acid ester;

in the step S2:

the alkaline substance is selected from one or more of sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate;

in the step S3:

the initiator is selected from potassium persulfate and/or sodium persulfate;

the internal crosslinking agent is ethylene glycol diglycidyl ether and/or methylene bisacrylamide.

Preferably, the amount of the dispersant used in the step S1 is 0.5 wt% to 3 wt% of the mass of the acrylic monomer used in the step S2;

the dosage of the surfactant in the step S1 is 0.5-3 wt% of the mass of the acrylic acid monomer in the step S2;

in the step S1, the mass ratio of the hydrocarbon dispersion medium to the dispersant is (100-400) to 1;

the using amount of the initiator in the step S3 is 0.01-0.3 mol% of the molar amount of the acrylic monomer in the step S2;

the amount of the internal crosslinking agent used in the step S3 is 0.01 mol% to 0.3 mol% of the molar amount of the acrylic monomer used in the step S2.

The invention provides a method for producing super absorbent resin, which is specifically as described above. Firstly, respectively preparing a base solution, a neutralizing solution and an initiating solution, and then sending the base solution, the neutralizing solution and the initiating solution into a reactor for primary polymerization reaction to obtain a primary reaction solution; and then, filtering the obtained primary reaction liquid through a filter plate at the outlet of the reactor, removing the filtrate into a flash evaporator, and keeping a solid product in the reactor as a raw material for the next reaction. Then, replenishing base liquid, neutralizing liquid and initiating liquid into the reactor, carrying out constant temperature treatment for a period of time at room temperature, and then heating for carrying out secondary polymerization reaction to obtain secondary reaction liquid; then continuing to heat the secondary reaction liquid for azeotropic dehydration and surface crosslinking to form steam and final reaction liquid; wherein the final reaction liquid is filtered by a filter plate at the outlet of the reactor, the filtrate is removed into a flash evaporator, and the solid product is retained in the reactor; then, the filter plate is opened again, and the solid product is discharged and sent to a dryer for drying, thereby obtaining the polyacrylate super absorbent resin.

In the prior art, energy loss and efficiency reduction are caused by frequent temperature rise and drop after the primary polymerization reaction, but the production method provided by the invention directly filters out continuous phase base liquid in the reactor after the primary polymerization reaction, saves cooling time and energy required by cooling, reduces energy consumption and greatly improves production efficiency. In addition, in the prior art, the solubility of the dispersing agent is reduced and the dispersing agent is separated out and loses the protective effect due to cooling and cooling after primary polymerization, but the continuous phase base liquid is discharged after primary polymerization, and new hydrocarbon dispersion medium, dispersing agent and surfactant are added before secondary polymerization, so that the energy consumption can be effectively reduced, the adhesion among particles can be facilitated, the agglomeration among particles can be facilitated, the particle size of the particles can meet the requirements, and the product quality can be ensured.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic view of the structure of a production apparatus used in the production method provided by the present invention.

Detailed Description

the production apparatus includes:

a reactor V001; a discharge hole of the reactor V001 is provided with a filter plate;

the discharge port of the mixer H001 is communicated with the feed port of the reactor V001;

the discharge port is communicated with the feed port of the mixer H001, and the neutralizing liquid tank V002 is communicated with the feed port of the mixer H001;

the discharge port is communicated with the feed port of the mixer H001 to form a priming liquid tank V003;

the liquid inlet of the flash evaporator T001 is communicated with the discharge hole of the reactor V001;

the feed inlet of the dryer G001 is communicated with the discharge outlet of the reactor V001;

a condenser E001 with an air inlet communicated with the air outlet of the flash evaporator T001; the condenser E001 is also communicated with the gas outlet of the reactor V001;

the production process comprises the following steps:

s1, sending the hydrocarbon dispersion medium, the dispersing agent and the surfactant into a reactor V001 for mixing and dissolving to obtain base liquid;

s2, feeding the acrylic acid monomer and the alkali liquor to a neutralization liquid tank V002 for neutralization reaction to obtain a neutralization liquid;

s3, sending the initiator, the internal crosslinking agent and water to a priming liquid tank V003 for mixing and dissolving to obtain a priming liquid;

s4, feeding the neutralization solution in the neutralization solution tank V002 and the priming solution in the priming solution tank V003 to a mixer H001 for mixing and keeping the temperature constant to obtain a mixed solution 1;

s5, sending the mixed solution 1 to a reactor V001 for primary polymerization reaction to obtain primary reaction solution; then, filtering the obtained primary reaction liquid through a filter plate at the outlet of the reactor V001, removing the filtrate into a flash evaporator T001, and keeping a solid product in the reactor V001;

the filtrate entering the flash evaporator T001 is subjected to flash separation, and the formed hydrocarbon dispersion medium vapor and the separation liquid are operated in two paths: the hydrocarbon dispersion medium steam ascends through the air outlet and is discharged out and enters the condenser E001 for condensation and recovery; the separated liquid is discharged from the flash evaporator T001;

s6, supplementing a hydrocarbon dispersion medium, a dispersing agent and a surfactant into the reactor V001; feeding the neutralization solution in the neutralization solution tank V002 and the priming solution in the priming solution tank V003 to the mixer H001 again for mixing to obtain a mixed solution 2;

s7, sending the mixed solution 2 into a reactor V001, carrying out constant temperature treatment at room temperature, and then heating for secondary polymerization reaction to obtain a secondary reaction solution; then continuing to heat the secondary reaction liquid for azeotropic dehydration and surface crosslinking to form steam and final reaction liquid; the steam and the final reaction liquid are operated in two paths: the steam is discharged through a gas outlet and enters a condenser E001 for condensation and recovery; filtering the final reaction liquid through a filter plate at the outlet of the reactor V001, removing the filtrate into a flash evaporator T001, and keeping a solid product in the reactor V001; then, opening the filter plate, discharging the solid product and sending the solid product into a dryer G001 for drying, thereby obtaining the polyacrylate super absorbent resin;

the step S1, the step S2, and the step S3 are not limited in order.

Referring to fig. 1, fig. 1 is a schematic structural view of a production apparatus used in the production method provided by the present invention; wherein V001 is a reactor, V002 is a neutralization liquid tank, P2-1 is a neutralization liquid delivery pump, V003 is an initiation liquid tank, P3-1 is an initiation liquid delivery pump, H001 is a mixer, T001 is a flash evaporator, G001 is a dryer, and E001 is a condenser.

About production equipment：

According to the invention, the production plant comprises: reactor V001. In the present invention, the reactor V001 is preferably a reaction kettle.

In the invention, a filter plate is arranged at the discharge port of the reactor V001, and the filter plate is movably connected with the discharge port of the reactor V001, namely the filter plate can be lapped at the discharge port to filter the materials in the V001, and can also be pumped up without filtering to completely discharge the materials in the V001; when liquid needs to be discharged, the materials in the reactor V001 are discharged from the filtrate through the filter plate, and when solid materials or solid-liquid mixtures need to be discharged, the solid materials or the solid-liquid mixtures are directly discharged without the filter plate.

In the present invention, it is preferable that the reactor V001 is provided with a stirrer. The structure of the stirrer is not particularly limited, and the stirrer is a conventional stirrer structure in the field, and comprises a motor, a stirring shaft and a stirring paddle, wherein the motor is fixedly connected to the top of the reactor V001, the stirring shaft vertically extends into the reactor V001, and the stirring paddle is positioned in the reactor V001 and plays a role in stirring materials.

In the invention, a feed inlet is arranged at the top or upper part of the reactor V001, and materials can be added into the reactor V001 through the feed inlet. In the invention, preferably, the number of the feed inlets is at least two; when two feed ports are provided, one is communicated with the mixer H001, and the other is used for receiving the hydrocarbon dispersion medium, the dispersant and the surfactant.

According to the invention, the production plant comprises: the discharge hole of the mixer H001 is communicated with the feed hole of the reactor V001. The mixer H001 is used to receive and mix materials and then feed the resulting mixture into the reactor V001.

According to the invention, the production plant comprises: and the neutralizing liquid tank V002, wherein the discharge hole of the neutralizing liquid tank V002 is communicated with the feed inlet of the mixer H001. The invention prepares the neutralization solution through a neutralization solution tank V002 and conveys the neutralization solution to a mixer H001.

In the present invention, it is preferable that the neutralization liquid tank V002 be provided with a stirrer. The structure of the stirrer is not particularly limited, and the stirrer is a conventional stirrer structure in the field, for example, the stirrer comprises a motor, a stirring shaft and a stirring paddle, wherein the motor is fixedly connected to the top of the neutralization liquid tank V002, the stirring shaft vertically extends into the neutralization liquid tank V002, and the stirring paddle is positioned in the neutralization liquid tank V002 and plays a role in stirring materials.

In the present invention, preferably, the production apparatus further includes: and a neutralization liquid delivery pump P2-1 communicated between the neutralization liquid tank V002 and the mixer H001. The invention pumps the prepared neutralization solution in the neutralization solution tank V002 into the mixer H001 through the neutralization solution delivery pump P2-1. In the invention, preferably, the neutralization liquid delivery pump P2-1 is a metering pump, and can realize quantitative pumping.

According to the invention, the production plant comprises: and the discharge hole of the initiation liquid tank V003 is communicated with the feed inlet of the mixer H001. The present invention prepares the priming solution by the priming solution tank V003 and delivers the priming solution to the mixer H001.

In the present invention, it is preferable that the priming liquid tank V003 be provided with a stirrer. The structure of the stirrer is not particularly limited, and the stirrer is a conventional stirrer structure in the field, for example, the stirrer comprises a motor, a stirring shaft and a stirring paddle, wherein the motor is fixedly connected to the top of the initiating liquid tank V003, the stirring shaft vertically extends into the initiating liquid tank V003, and the stirring paddle is positioned in the initiating liquid tank V003 and plays a role in stirring materials.

In the present invention, preferably, the production apparatus further includes: and a priming liquid delivery pump P3-1 communicated between the priming liquid tank V003 and the mixer H001. The prepared priming solution in the priming solution tank V003 is pumped into the mixer H001 by the neutralization solution delivery pump P3-1. In the invention, preferably, the priming liquid delivery pump P3-1 is a metering pump, and can realize quantitative pumping.

According to the invention, the production plant comprises: and a liquid inlet of the flash evaporator T001 is communicated with a discharge hole of the reactor V001. The invention removes the filtrate obtained by filtering the reaction liquid obtained in the reactor V001 by the filter plate at the discharge port into the flash evaporator T001 for flash separation to form steam and separation liquid, and the operation is divided into two paths: the vapor ascends and is discharged from a gas outlet at the top of the flash evaporator T001, and the separated liquid descends and is discharged from a discharge hole at the bottom of the flash evaporator T001. The steam mainly contains hydrocarbon dispersion medium and can be recovered. The separated liquid discharged from the bottom can be sent to a wastewater treatment device for treatment.

According to the invention, the production plant comprises: and the air inlet of the condenser E001 is communicated with the air outlet of the flash evaporator T001, and meanwhile, the condenser E001 is also communicated with the air outlet of the reactor V001. The vapor (mainly hydrocarbon dispersion medium) discharged from the gas outlet at the top of the flash evaporator T001 enters the condenser E001 to be condensed to form a condensate, thereby recovering the hydrocarbon dispersion medium. In addition, in the case where azeotropic dehydration is performed after the completion of the secondary polymerization reaction in the reactor V001, the vapor discharged from the top (the main component is also the hydrocarbon dispersion medium) also enters the condenser E001 and is condensed to form a condensate, and the hydrocarbon dispersion medium is recovered. Through the arrangement, the hydrocarbon dispersion medium can be recovered in multiple steps and can be recycled, so that the environmental pollution is reduced, and the preparation cost is reduced.

According to the invention, the production plant comprises: and the feed inlet of the dryer G001 is communicated with the discharge outlet of the reactor V001. The invention filters the filtrate of the materials after the polymerization reaction in the reactor V001 is finished, and then sends the materials to a dryer G001 for drying, thereby obtaining the polyacrylate super absorbent resin product.

In the production equipment, each connecting pipeline is provided with a valve for controlling the on-off of the material conveying of the corresponding pipeline.

About the production method：

Regarding step S1: the hydrocarbon dispersion medium, the dispersant and the surfactant are fed into a reactor V001 to be mixed and dissolved, thereby obtaining a base liquid.

In the invention, the hydrocarbon dispersion medium is a petroleum hydrocarbon dispersion medium, preferably one or more of n-hexane, n-heptane, cyclohexane and benzene.

In the invention, the dispersant is preferably one or more of maleic anhydride-propylene copolymer, oxidized polyethylene and maleic anhydride-ethylene copolymer.

In the present invention, the surfactant is preferably a glycerin fatty acid ester and/or a sucrose fatty acid ester.

In the present invention, the amount of the dispersant is 0.5 wt% to 3 wt%, specifically 0.5 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, based on the mass of the acrylic monomer in step S2. In the present invention, the amount of the surfactant is 0.5 wt% to 3 wt%, specifically 0.5 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, based on the mass of the acrylic monomer in step S2. In the present invention, the mass ratio of the hydrocarbon dispersion medium to the dispersant is preferably (100 to 400): 1, and specifically may be 100: 1, 200: 1, 300: 1, or 400: 1. In the invention, specifically, the amount of the acrylic acid monomer added into the neutralization liquid tank V002 is designed in advance, the amount of the dispersing agent and the surfactant is calculated according to the ratio of the amount of the acrylic acid monomer to the amount of the dispersant, the amount of the hydrocarbon dispersion medium is calculated, and then the dispersing agent, the surfactant and the hydrocarbon dispersion medium are added into the reactor V001.

In the present invention, the mixing and dissolving temperature is preferably 50 to 100 ℃, and specifically 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃ and 100 ℃. In the present invention, the mixing and dissolving are preferably performed under stirring conditions; the stirring speed is preferably 100-500 rpm, and specifically may be 100rm, 150rpm, 200rpm, 250rpm, 300rpm, 350rpm, 400rpm, 450rpm, 500 rpm. Stirring and dissolving for 30-90 min to obtain a uniformly mixed base solution.

In the present invention, after the above-mentioned mixing and dissolution, an inert gas is introduced into the reactor V001 to remove oxygen. The inert gas used in the present invention is not particularly limited, and may be any inert gas conventionally used in the art, such as nitrogen, helium, argon, or the like. An inert atmosphere is provided for the mixing and polymerization reaction in the subsequent reactor V001 by gas displacement.

Regarding step S2: acrylic acid monomer and alkali liquor are sent to a neutralization liquid tank V002 for neutralization reaction to obtain neutralization liquid.

In the invention, the alkali liquor is an alkaline solution formed by dissolving an alkaline substance in water. Wherein, the alkaline substance is preferably one or more of sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate. In the invention, the mass concentration of the alkali liquor is preferably 28-32 wt%, and more preferably 30 wt%; if the concentration of the alkali liquor is too high, the reaction is not favorable for stable proceeding, the product quality is influenced, and if the concentration of the alkali liquor is too low, the reaction efficiency is influenced, and the subsequent distillation treatment is not favorable.

In the invention, the mass ratio of the acrylic acid monomer to the alkali liquor is preferably (60-90) to (20-50), and under the condition of controlling the mass ratio, a part of acrylic acid monomer (but not all monomers) and an alkaline substance are subjected to neutralization reaction, so that incompletely neutralized neutralizing liquor is formed. In the present invention, the neutralization degree of the neutralization solution is preferably 50% to 80%, and specifically may be 50%, 55%, 60%, 65%, 70%, 75%, 80%. The neutralization degree refers to the ratio of the molar amount of the acrylate generated by the neutralization reaction to the molar amount of the acrylic acid monomer before the neutralization reaction. In the present invention, the order of addition is preferably: firstly adding acrylic monomer, and then gradually adding alkali liquor.

In the present invention, it is preferable to mix the acrylic acid monomer and the alkali solution under stirring and perform neutralization reaction. In the present invention, the stirring rate is preferably 50 to 100rpm, and specifically may be 50rpm, 60rpm, 70rpm, 80rpm, 90rpm, or 100 rpm.

In the invention, the temperature of the neutralization reaction and the obtained neutralization solution is controlled to be less than or equal to 45 ℃, more preferably 30-45 ℃, and specifically 30 ℃, 35 ℃, 40 ℃ and 45 ℃. In the invention, the temperature is controlled by controlling the feeding speed of the alkali liquor. After the neutralization reaction, a neutralized liquid is formed in the neutralized liquid tank V002.

Regarding step S3: and (3) sending the initiator, the internal crosslinking agent and water to a priming liquid tank V003 for mixing and dissolving to obtain the priming liquid.

In the present invention, the initiator is preferably potassium persulfate and/or sodium persulfate. In the present invention, the amount of the initiator to be used is preferably 0.01 mol% to 0.3 mol%, and specifically may be 0.01 mol%, 0.05 mol%, 0.10 mol%, 0.15 mol%, 0.20 mol%, 0.25 mol%, 0.30 mol%, based on the molar amount of the acrylic monomer in step S2.

In the invention, the internal crosslinking agent is preferably ethylene glycol diglycidyl ether and/or methylene bisacrylamide. In the present invention, the amount of the internal crosslinking agent to be used is preferably 0.01 mol% to 0.3 mol%, and specifically may be 0.01 mol%, 0.05 mol%, 0.10 mol%, 0.15 mol%, 0.20 mol%, 0.25 mol%, 0.30 mol%, based on the molar amount of the acrylic monomer in step S2.

In the present invention, the water is preferably deionized water. In the invention, the dosage ratio of the water to the initiator is preferably (50000-100000) mL to 1mol, and specifically can be 50000mL to 1mol, 60000mL to 1mol, 70000mL to 1mol, 80000mL to 1mol, 90000mL to 1mol and 100000mL to 1 mol. In the invention, specifically, the amount of the acrylic acid monomer added into the neutralization liquid tank V002 is designed in advance, the amount of the initiator and the amount of the internal crosslinking agent are calculated according to the ratio relationship of the amounts, the amount of water is further calculated, and the initiator, the internal crosslinking agent and the water are added into the initiation liquid tank V003.

In the invention, the mixing and dissolving temperature is preferably 20-60 ℃, and specifically can be 20 ℃, 30 ℃, 40 ℃, 50 ℃ and 60 ℃. In the present invention, the mixing and dissolving are preferably performed under stirring conditions; the stirring speed is preferably 100 to 800rpm, and specifically may be 100rm, 150rpm, 200rpm, 250rpm, 300rpm, 350rpm, 400rpm, 450rpm, 500rpm, 550rpm, 600rpm, 650rpm, 700rpm, 750rpm, 800 rpm. Stirring and dissolving until the solution is clear and transparent to obtain the evenly mixed priming solution.

The sequence of the steps S1, S2, and S3 is not particularly limited, and may be performed sequentially or simultaneously.

Regarding step S4: and (3) sending the neutralization solution in the neutralization solution tank V002 and the priming solution in the priming solution tank V003 to a mixer H001 for mixing and keeping the temperature constant to obtain a mixed solution 1.

In the present invention, it is preferable that the neutralization liquid in the neutralization liquid tank V002 is fed into the mixer H001 by the neutralization liquid feed pump P2-1, and the priming liquid in the priming liquid tank V003 is fed into the mixer H001 by the priming liquid feed pump P3-1.

In the present invention, after the neutralization solution and the priming solution are sent to the mixer H001, the next step is not carried out, but the neutralization solution and the priming solution are first treated at a constant temperature in the mixer H001. In the invention, the constant temperature treatment is preferably performed at a constant temperature of 30-80 ℃, and specifically at 30 ℃, 40 ℃, 50 ℃, 60 ℃, 70 ℃ and 80 ℃. After the constant temperature treatment, mixed liquid 1 with a certain temperature is obtained.

Regarding step S5: sending the mixed solution 1 to a reactor V001 for primary polymerization reaction to obtain primary reaction liquid; then, filtering the obtained primary reaction liquid through a filter plate at the outlet of the reactor V001, removing the filtrate into a flash evaporator T001, and keeping a solid product in the reactor V001; the filtrate entering the flash evaporator T001 is subjected to flash separation, and the formed hydrocarbon dispersion medium vapor and the separation liquid are operated in two paths: the hydrocarbon dispersion medium steam ascends through the air outlet and is discharged out and enters the condenser E001 for condensation and recovery; the separated liquid was discharged from the flash evaporator T001.

In the present invention, after the mixed solution 1 is obtained in step S4, the mixed solution 1 is fed to the reactor V001 and mixed with the base solution prepared in advance in the reactor V001 to carry out the primary polymerization reaction. In the present invention, the polymerization reaction is preferably carried out under stirring conditions; the stirring speed is preferably 200-600 rpm, and specifically may be 200rpm, 300rpm, 400rpm, 500rpm, 600 rpm. In the invention, the polymerization reaction temperature is preferably 60-80 ℃, and specifically 60 ℃, 65 ℃, 70 ℃, 75 ℃ and 80 ℃. In the invention, the time of the polymerization reaction is preferably 0.5-2 h, and more preferably 1 h. In the above polymerization reaction process, the acrylic monomer and the acrylic acid salt are polymerized into particles, and the resulting reaction liquid contains a base liquid, a small amount of unreacted acrylic acid solution, and the like in addition to the polymer solid particles.

In the present invention, after the primary polymerization reaction, the obtained primary reaction liquid is filtered through a filter plate at the outlet of the reactor V001, the filtrate (including the base liquid and a small amount of unreacted acrylic acid solution) is removed into the flash evaporator T001, and the solid product is retained in the reactor V001.

Wherein, the filtrate entering the flash evaporator T001 is subjected to flash separation, and the formed hydrocarbon dispersion medium vapor and the separation liquid are operated in two paths: the hydrocarbon dispersion medium steam ascends through the air outlet and is discharged out and enters the condenser E001 for condensation and recovery; the separated liquid was discharged from the flash evaporator T001. In the present invention, the separated liquid may be sent to a wastewater treatment apparatus for treatment after being discharged from the flash evaporator T001.

After the above-mentioned series of treatments, the polymer solid particles formed by one polymerization reaction were retained in the reactor V001.

Regarding step S6: supplementing a hydrocarbon dispersion medium, a dispersant and a surfactant into the reactor V001; the neutralized liquid in the neutralized liquid tank V002 and the priming liquid in the priming liquid tank V003 were again fed to the mixer H001 and mixed to obtain a mixed liquid 2.

In the present invention, the amount of the hydrocarbon dispersion medium to be added to the reactor V001 is preferably 1 to 1.5 times the mass of the filtrate removed in the flash evaporator T001 in step S5. In the present invention, the addition amount of the dispersant and the hydrocarbon dispersion medium to be added are in the same range as the first addition in step S1; the addition amount of the surfactant is in the same range as the hydrocarbon dispersion medium to be added in the first addition in step S1; are not described in detail herein. Specifically, the replenishment amount of the hydrocarbon dispersion medium is known, and the replenishment amount of the dispersant can be calculated from the ratio of the dispersant usage amount to the hydrocarbon dispersion medium usage amount, and similarly, the replenishment amount of the surfactant can be calculated.

In the present invention, the selection ranges of the hydrocarbon dispersion medium, the dispersant and the surfactant are the same as those described above, and are not described herein again; preferably, the hydrocarbon dispersion medium, the dispersant and the surfactant to be supplemented are the same as those used in the above-mentioned primary polymerization.

In the present invention, the neutralized liquid in the neutralized liquid tank V002 and the priming liquid in the priming liquid tank V003 are also fed again to the mixer H001 and mixed.

In the present invention, the selection range of the component types and the component distribution ratio range in the neutralization solution are the same as those of the neutralization solution, and are not described herein again. In the invention, specifically, after the primary polymerization reaction is finished, acrylic acid monomer and alkali liquor can be conveyed into the neutralization liquid tank V002 again for neutralization reaction to form neutralization liquid, and then the neutralization liquid is conveyed into the mixer H001; alternatively, the neutralization liquid in the neutralization liquid tank V002 may not be used up in the first polymerization reaction, and then the originally remaining neutralization liquid in the neutralization liquid tank V002 may be fed to the mixer H001 in step S6. In the present invention, when the neutralized liquid in the neutralized liquid tank V002 is fed again to the mixer H001, the ratio of the amount of acrylic acid monomer to the amount of dispersant to be replenished in the formation of the neutralized liquid is in the same range as that in the above-mentioned one-shot polymerization. Specifically, the amount of the acrylic monomer can be calculated from the dispersant replenishment amount calculated in the foregoing, and the amount of the neutralized liquid to be transported can be determined from the relationship between the dispersant replenishment amount and the amount of the acrylic monomer.

In the present invention, the selection range of the component types and the distribution range of the components in the priming solution are the same as those of the priming solution, and are not described herein again. In the invention, specifically, after the primary polymerization reaction is finished, the initiator, the internal crosslinking agent and the water can be conveyed into the initiation liquid tank V003 again for mixing and dissolving to form the initiation liquid, and then the initiation liquid is conveyed into the mixer H001; after the initial polymerization reaction has not run out of the initiator in the initiator tank V003, the remaining initiator in the initiator tank V003 may be fed to the mixer H001 in step S6. In the present invention, when the initiator in the initiator liquid tank V003 is fed again to the mixer H001, the ratio of the amount of the initiator and the internal crosslinking agent in the initiator liquid to the amount of the acrylic acid monomer in the neutralized liquid to be fed is controlled so that the ratio thereof to the amount in the first polymerization reaction is in the same range. Specifically, the amount of the initiator to be supplemented can be calculated according to the amount ratio of the amount of the initiator to the amount of the acrylic monomer calculated in the foregoing, and the amount of the priming solution can be determined.

In the present invention, the neutralized liquid in the neutralized liquid tank V002 and the priming liquid in the priming liquid tank V003 are again fed to the mixer H001 and mixed to obtain a mixed liquid 2.

Regarding step S7: sending the mixed solution 2 into a reactor V001, carrying out constant-temperature treatment at room temperature, and then heating for secondary polymerization reaction to obtain secondary reaction solution; then continuing to heat the secondary reaction liquid for azeotropic dehydration and surface crosslinking to form steam and final reaction liquid; the steam and the final reaction liquid are operated in two paths: the steam is discharged through a gas outlet and enters a condenser E001 for condensation and recovery; filtering the final reaction liquid through a filter plate at the outlet of the reactor V001, removing the filtrate into a flash evaporator T001, and keeping a solid product in the reactor V001; then, the filter plate was opened again, and the solid product was discharged and sent to a dryer G001 to be dried, thereby obtaining a polyacrylate type super absorbent resin.

In the present invention, the mixed solution 2 is fed into the reactor V001 and then treated at a constant temperature at room temperature. The room temperature may be 15-30 deg.C, specifically 15 deg.C, 20 deg.C, 25 deg.C, 30 deg.C. The time of the constant temperature treatment is preferably 0.5-1.5 h, and more preferably 0.5 h. In the first polymerization reaction, polyacrylate particles are formed, the dispersing medium, the dispersing agent and the surfactant are added before the second polymerization reaction, and the dispersing agent can be adhered to the particles through constant-temperature treatment, so that the effect of dispersing the particles by the dispersing agent is better.

In the present invention, after the above constant temperature treatment, the temperature is raised to perform the secondary polymerization reaction. In the invention, the temperature of the secondary polymerization reaction is preferably 60-80 ℃, and specifically 60 ℃, 65 ℃, 70 ℃, 75 ℃ and 80 ℃. In the invention, the time of the secondary polymerization reaction is preferably 0.5-3 h, and more preferably 1 h. In the present invention, the secondary polymerization reaction is preferably carried out under stirring conditions, and the stirring rate is preferably 200 to 600rpm, and specifically may be 200rpm, 250rpm, 300rpm, 350rpm, 400rpm, 450rpm, 500rpm, 550rpm, 600 rpm.

In the present invention, after the secondary polymerization reaction, the obtained secondary reaction liquid is heated continuously to conduct azeotropic dehydration, thereby forming a vapor (mainly containing a hydrocarbon dispersion medium) and a separation liquid. In the invention, the temperature is preferably raised to 90-130 ℃ continuously, and the temperature can be 90 ℃, 100 ℃, 110 ℃, 120 ℃ and 130 ℃. At the same time of the azeotropic dehydration, the surface crosslinking occurs in the reactor V001, so that the polymer particles are crosslinked to form a network crosslinked polymer with a more complex structure.

The vapor and separated liquid formed by the above treatment are operated in two paths: the steam is discharged through a gas outlet and enters a condenser E001 for condensation and recovery; the separated liquid is filtered through a filter plate at the outlet of the reactor V001, the filtrate is removed into the flash evaporator T001, and the solid product is retained in the reactor V001. In the invention, after the filtrate is removed into the flash evaporator T001, the flash separation can be carried out again as described above, the formed steam is discharged from the gas outlet of the flash evaporator T001 and enters the condenser E001 for condensation, the dispersion medium is recovered, and the formed separation liquid is discharged from the discharge port of the flash evaporator T001 and can be sent to a wastewater treatment device for treatment. In the present invention, the filtrate removed in step S5 and the filtrate removed in step S7 may be combined after entering the flash evaporator T001, and then flash separation is performed together.

In the present invention, the solid product remaining in the reactor V001 is dried by opening the filter plate at the discharge port of the reactor V001, discharging the solid product, and sending the solid product to the dryer G001. In the present invention, the drying is preferably vacuum drying. In the invention, the drying temperature is preferably 90-130 ℃. Drying to obtain the polyacrylate super absorbent resin.

Test results show that the production method provided by the invention can reduce energy consumption and improve production efficiency, and the water absorption speed of the obtained product is better than 18s, the water retention rate reaches over 38g/g, and the product shows better water absorption and water retention rate.

For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.

Example 1

1. Preparation of Water-absorbent resin

The production was carried out using the production setup shown in fig. 1, the procedure being specifically as follows:

s1, feeding a dispersing medium of n-heptane, a dispersing agent of maleic anhydride-propylene copolymer and a surfactant of glycerin fatty acid ester into a reactor V001, and stirring and dissolving at the temperature of 50 ℃ and the stirring speed of 500rpm to obtain a base liquid. And introducing nitrogen to remove oxygen.

Wherein the amount of the dispersant is 0.5% by mass of the acrylic monomer in step S2, the amount of the surfactant is 0.5% by mass of the acrylic monomer in step S2, and the mass ratio of the dispersion medium to the dispersant is 1: 0.005.

S2, 184g of acrylic acid monomer and 250g of sodium hydroxide aqueous solution (30 wt% in mass concentration) are fed into a neutralization liquid tank V002, and the mixture is stirred and neutralized at 50rpm, and the addition rate of the alkali liquid is controlled so that the temperature of the neutralization liquid is maintained at 30 ℃, and the neutralization degree of the obtained neutralization liquid is 75%.

S3, sending the initiator potassium persulfate, the internal crosslinking agent ethylene glycol diglycidyl ether and the deionized water to an initiation liquid tank V003, and stirring and dissolving at the temperature of 30 ℃ and the stirring speed of 100rpm to obtain the initiation liquid.

Wherein the molar weight of the initiator accounts for 0.01 mol% of the molar weight of the acrylic monomer in the step S2, the molar weight of the internal crosslinking agent accounts for 0.01 mol% of the molar weight of the acrylic monomer in the step S2, and the dosage ratio of the deionized water to the initiator is 80000 mL: 1 mol.

S4, pumping the neutralization solution in the neutralization solution tank V002 into the mixer H001 through a metering pump P2-1, simultaneously sending the priming solution in the priming solution tank V003 into the mixer H001 through a metering pump P3-1, and keeping the temperature to 30 ℃ to obtain a mixed solution 1.

S5, feeding the mixed solution 1 into a reactor V001, and carrying out primary polymerization reaction at 600rpm and 60 ℃ for 1h to obtain a primary reaction solution. And filtering the obtained primary reaction liquid through a filter plate at the outlet of the reactor V001, removing the filtrate into a flash evaporator T001, and keeping a solid product in the reactor V001 to participate in the next reaction.

S6, supplementing a dispersing medium n-heptane, a dispersing agent maleic anhydride-propylene copolymer and a surfactant glycerin fatty acid ester into a reactor V001; at the same time, the neutralized liquid in the neutralized liquid tank V002 and the priming liquid in the priming liquid tank V003 were fed again to the mixer (H001) and mixed, thereby obtaining a mixed liquid 2.

Wherein the mass of the supplementary dispersion medium is the same as the amount of the filtrate removed in step S5. The relationship between the amount of the dispersant and the surfactant to be supplied and the amount of the dispersion medium to be supplied is the same as that in step S1. The mass of the neutralizing solution and the mass of the priming solution to be supplemented were the same as the ratios of the amounts of the respective raw materials used in the steps S2 to S3.

S7, feeding the mixed solution 2 into a reactor V001, and keeping the temperature at 25 ℃ for 0.5 h. Then, the temperature was raised to 60 ℃ and the secondary polymerization was carried out under stirring at 600rpm for 1 hour to obtain a secondary reaction solution. Then, the secondary reaction solution was further heated to 90 ℃ and maintained for 3 hours to conduct azeotropic dehydration and surface crosslinking, thereby forming a vapor and a final reaction solution. Wherein, the formed steam is discharged through a gas outlet and enters a condenser E001 for condensation and recovery; the final reaction liquid obtained is filtered through a filter plate at the outlet of the reactor V001, the filtrate is removed into a flash evaporator T001, and the solid product is retained in the reactor V001.

Then, the filter plate at the discharge port of the reactor V001 is opened, the solid product is discharged and sent to a dryer G001, and vacuum drying is carried out at 130 ℃ to obtain the polyacrylate super absorbent resin.

In the preparation process, after the filtrate removed in the step S5 and the filtrate removed in the step S7 enter a flash evaporator T001, flash separation is carried out, and the formed hydrocarbon dispersion medium vapor and the separation liquid are operated in two ways: the hydrocarbon dispersion medium steam ascends through a gas outlet and is discharged out and enters a condenser E001 for condensation and recovery; the separated liquid is discharged from the flash evaporator T001 and sent to a wastewater treatment device for treatment.

Example 2

s1, feeding a dispersion medium n-heptane, a dispersant oxidized polyethylene and a surfactant sucrose fatty acid ester into a reactor V001, and stirring and dissolving at the temperature of 80 ℃ and the stirring speed of 300rpm to obtain a base solution. And introducing nitrogen to remove oxygen.

Wherein the amount of the dispersant accounts for 1.5% of the mass of the acrylic monomer in the step S2, the amount of the surfactant accounts for 1.5% of the mass of the acrylic monomer in the step S2, and the mass ratio of the dispersion medium to the dispersant is 1: 0.005.

S2, 220g of acrylic acid monomer and 229g of sodium hydroxide aqueous solution (30 wt% in mass concentration) are fed into a neutralization liquid tank V002, and are stirred and neutralized at 80rpm, and the addition rate of the alkali liquid is controlled during the addition so that the temperature of the neutralization liquid is kept at 35 ℃, and the neutralization degree of the obtained neutralization liquid is 70%.

S3, sending the initiator sodium persulfate, the internal cross-linking agent methylene bisacrylamide and the deionized water to an initiation liquid tank V003, and stirring and dissolving at the temperature of 30 ℃ and the stirring speed of 500rpm to obtain the initiation liquid.

Wherein the molar weight of the initiator accounts for 0.15 mol% of the molar weight of the acrylic monomer in the step S2, the molar weight of the internal crosslinking agent accounts for 0.15 mol% of the molar weight of the acrylic monomer in the step S2, and the dosage ratio of the deionized water to the initiator is 80000 mL: 1 mol.

S4, pumping the neutralization solution in the neutralization solution tank V002 into the mixer H001 through a metering pump P2-1, simultaneously sending the priming solution in the priming solution tank V003 into the mixer H001 through a metering pump P3-1, and keeping the temperature to 50 ℃ to obtain a mixed solution 1.

S5, feeding the mixed solution 1 into a reactor V001, and carrying out primary polymerization reaction at 400rpm and 70 ℃ for 1h to obtain a primary reaction solution. And filtering the obtained primary reaction liquid through a filter plate at the outlet of the reactor V001, removing the filtrate into a flash evaporator T001, and keeping a solid product in the reactor V001 to participate in the next reaction.

S6, supplementing a dispersing medium n-heptane, a dispersing agent oxidized polyethylene and a surfactant sucrose fatty acid ester into the reactor V001; at the same time, the neutralized liquid in the neutralized liquid tank V002 and the priming liquid in the priming liquid tank V003 were fed again to the mixer H001 and mixed, thereby obtaining a mixed liquid 2.

Wherein the mass of the supplementary dispersion medium is equal to the removal amount of the filtrate in the step S5. The relationship between the amount of the dispersant and the surfactant to be supplied and the amount of the dispersion medium to be supplied is the same as that in step S1. The mass of the neutralizing solution and the mass of the priming solution to be supplemented were the same as the ratios of the amounts of the respective raw materials used in the steps S2 to S3.

S7, feeding the mixed solution 2 into a reactor V001, and keeping the temperature at 25 ℃ for 0.5 h. Then, the temperature was raised to 70 ℃ and the secondary polymerization was carried out under stirring at 400rpm for 1 hour to obtain a secondary reaction solution. Then, the secondary reaction solution was further heated to 110 ℃ and maintained for 3 hours to conduct azeotropic dehydration and surface crosslinking, thereby forming a vapor and a final reaction solution. Wherein, the formed steam is discharged through a gas outlet and enters a condenser E001 for condensation and recovery; the final reaction liquid obtained is filtered through a filter plate at the outlet of the reactor V001, the filtrate is removed into a flash evaporator T001, and the solid product is retained in the reactor V001.

In the preparation process, after the filtrate removed in the steps S5 and S7 enters a flash evaporator T001, flash separation is carried out, and the formed hydrocarbon dispersion medium vapor and the separation liquid are operated in two paths: the hydrocarbon dispersion medium steam ascends through a gas outlet and is discharged out and enters a condenser E001 for condensation and recovery; the separated liquid is discharged from the flash evaporator T001 and sent to a wastewater treatment device for treatment.

Example 3

s1, feeding a dispersing medium n-heptane, a dispersing agent maleic anhydride-ethylene copolymer and a surfactant sucrose fatty acid ester into a reactor V001, and stirring and dissolving at 100 ℃ and 100rpm to obtain a base solution. And introducing nitrogen to remove oxygen.

Wherein the dosage of the dispersant accounts for 3 percent of the mass of the acrylic monomer in the step S2, the dosage of the surfactant accounts for 3 percent of the mass of the acrylic monomer in the step S2, and the mass ratio of the dispersion medium to the dispersant is 1: 0.005.

S2, 220g of acrylic acid monomer and 210g of sodium hydroxide aqueous solution (30 wt% in mass concentration) are fed into a neutralization liquid tank V002, and are stirred and neutralized at 100rpm, and the addition speed of the alkali liquor is controlled during the addition so that the temperature of the neutralization liquid is kept at 45 ℃, and the neutralization degree of the obtained neutralization liquid is 65%.

S3, sending the initiator sodium persulfate, the internal cross-linking agent methylene bisacrylamide and the deionized water to an initiation liquid tank V003, and stirring and dissolving at the temperature of 30 ℃ and the stirring speed of 800rpm to obtain the initiation liquid.

Wherein the molar weight of the initiator accounts for 0.3 mol% of the molar weight of the acrylic monomer in the step S2, the molar weight of the internal crosslinking agent accounts for 0.3 mol% of the molar weight of the acrylic monomer in the step S2, and the dosage ratio of the deionized water to the initiator is 80000 mL: 1 mol.

S4, pumping the neutralization solution in the neutralization solution tank V002 into the mixer H001 through a metering pump P2-1, simultaneously sending the priming solution in the priming solution tank V003 into the mixer H001 through a metering pump P3-1, and keeping the temperature to 80 ℃ to obtain a mixed solution 1.

S5, feeding the mixed solution 1 into a reactor V001, and carrying out primary polymerization reaction at 200rpm and 80 ℃ for 1h to obtain a primary reaction solution. And filtering the obtained primary reaction liquid through a filter plate at the outlet of the reactor V001, removing the filtrate into a flash evaporator T001, and keeping a solid product in the reactor V001 to participate in the next reaction.

S7, feeding the mixed solution 2 into a reactor V001, and keeping the temperature at 25 ℃ for 0.5 h. Then, the temperature was raised to 80 ℃ and the secondary polymerization was carried out under stirring at 200rpm for 1 hour to obtain a secondary reaction solution. Then, the secondary reaction solution was further heated to 130 ℃ and maintained for 3 hours to conduct azeotropic dehydration and surface crosslinking, thereby forming a vapor and a final reaction solution. Wherein, the formed steam is discharged through a gas outlet and enters a condenser E001 for condensation and recovery; the final reaction liquid obtained is filtered through a filter plate at the outlet of the reactor V001, the filtrate is removed into a flash evaporator T001, and the solid product is retained in the reactor V001.

Product characterization and testing:

(1) particle size distribution

The polyacrylate super absorbent resins obtained in examples 1 to 3 were subjected to particle size analysis, and the results are shown in Table 1.

TABLE 1 particle size distribution of resin particles obtained in examples 1 to 3

(2) Water absorbing and retaining capacity

The polyacrylate super absorbent resin particles obtained in examples 1 to 3 were subjected to water absorption rate and water retention tests. See table 2 for results.

The measurement of the water absorption rate of physiological saline was conducted in a room adjusted to 25 ℃. + -. 1 ℃. The water-absorbent resin was classified in advance with a standard sieve, and the water-absorbent resin passed through a 500 μm sieve and remained on a 250 μm sieve was taken as a resin sample. Then, 50. + -. 0.1g of physiological saline adjusted to 25. + -. 0.2 ℃ in volume of 100mL beaker by means of a magnetic stirring bar (8 mm. phi. times.30 mm, without ring) was stirred in a thermostatic water tank to generate vortex at 600 r/min. While stirring in this manner, 2.0 ± 0.002g of the resin sample was added to the physiological saline all at once, and the time (seconds) from the time when the vortex disappeared to the time when the liquid surface became flat after the addition of the resin sample was measured and this time was taken as the absorption rate of the physiological saline.

After that, the water-absorbent resin pellets after the above water absorption test were centrifuged, specifically, the water-absorbent resin pellets were dropped in a static state for 10min and then dehydrated under a centrifugal force of 250g for 3 min. After the centrifugation treatment, the resin particles were tested for water retention, which is (weight of resin particles after centrifugation-weight of resin particles before water absorption)/weight of resin particles before water absorption.

Table 2 Water absorption and Water retention test results of the resin particles obtained in examples 1 to 3

	Water absorption speed (second) of physiological saline	Water-retaining capacity (g/g) of physiological saline
			Example 1	14	47
Example 2	15	38
			Example 3	18	40

As can be seen from the above examples 1-3, in the production process of the invention, the energy consumption can be reduced, the production efficiency can be improved, and the water absorption speed of the obtained super absorbent resin product is better than 18s, the water retention rate reaches more than 38g/g, and the super absorbent resin product shows better water absorption and water retention rate.

The foregoing examples are provided to facilitate an understanding of the principles of the invention and their core concepts, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention. The scope of the invention is defined by the claims and may include other embodiments that occur to those skilled in the art. Such other embodiments are intended to be within the scope of the claims if they have structural elements that approximate the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

1. A production method of super absorbent resin is characterized in that production equipment is utilized to produce the super absorbent resin;

the production apparatus includes:

the production process comprises the following steps:

the step S1, the step S2, and the step S3 are not limited in order.

2. The production method according to claim 1, wherein in the step S1, the temperature of the mixed dissolution is 50-100 ℃;

3. The production method according to claim 1 or 2, wherein in the step S2, the mass concentration of the alkali liquor is 28-32 wt%;

4. The production method according to claim 1, wherein the constant temperature is constant to 30 to 80 ℃ in the step S4.

5. The production method according to claim 1, wherein in the step S5, the temperature of the primary polymerization reaction is 60 to 80 ℃ and the time is 0.5 to 2 hours.

6. The production method according to claim 1, wherein the amount of the hydrocarbon dispersion medium supplied in step S6 is 1 to 1.5 times the amount of the filtrate removed in step S5 to the flash evaporator (T001).

7. The production method according to claim 1, wherein in the step S7:

the constant temperature treatment time is 0.5-1.5 h;

and continuously heating to 90-130 ℃.

8. The production method according to claim 1, wherein in the production apparatus:

the neutralization liquid tank (V002) is provided with a stirrer;

the initiating liquid tank (V003) is arranged and connected with a stirrer;

the reactor (V001) is provided with a stirrer;

in the production process:

9. The production method according to claim 1,

in the step S1:

the surfactant is glycerin fatty acid ester and/or sucrose fatty acid ester;

in the step S2:

in the step S3:

the initiator is selected from potassium persulfate and/or sodium persulfate;

10. The production method according to claim 1, wherein the amount of the dispersant used in the step S1 is 0.5 to 3 wt% based on the mass of the acrylic monomer used in the step S2;