CN100558761C - Method for producing high-performance high-water-absorptivity resin - Google Patents

Abstract

A high water-absorption resin in powder form, insoluble in water, capable of absorbing water, urine or blood and having low soluble matter content is prepared through the following steps: (1) pre-polymerizing an acid group-containing monomer aqueous solution with a neutralization rate of more than 50mole percent and a polymerization initiator to obtain a viscous prepolymer, wherein the acid group-containing monomer is selected from acrylic acid, methacrylic acid, 2-allylamine-2-methylpropanesulfonic acid or a mixture thereof; (2) adding long-chain and high-hydrophilicity multi-epoxy compound into the viscous prepolymer, and further generating gel-like solid by utilizing a light-initiated polymerization mode; (3) drying, crushing and screening by hot air at the temperature of 100-; (4) coating treatment of a surface cross-linking agent; (5) heating the surface to 80-230 deg.C; (6) adding inert inorganic salt powder. The prepolymerization means that the monomer solution is retained in a pipeline and undergoes a radical polymerization reaction to become a viscous polymer.

Description

Production method of high-performance superabsorbent resin

technical field

The present invention relates to a method for producing a superabsorbent resin, especially a method for producing a water-absorbent resin with a low soluble content.

Background technique

The superabsorbent resin has a strong water retention capacity, can absorb a hundred times or even a thousand times its own weight of water, and can swell after absorbing water, and maintain a non-flowing state, even if pressure is applied, it will not leak, and the absorbed water Can be released slowly in the atmosphere. Due to the above characteristics, it was first used as a soil water retaining agent in agriculture and forestry. In recent years, due to considerable progress in the production technology of superabsorbent resin, it is also widely used in sanitary products such as diapers, adult incontinence products and women's hygiene products. water-absorbing agent and fresh-keeping applications for food preservation, etc.

The component materials of the superabsorbent resin include hydrolyzed starch-acrylonitrile (hydrolyzedstarch-acrylonitrile) graft polymer (Japanese Patent Publication 49 (1974)-43,395), neutralized starch acrylic acid graft polymer ( Japanese Patent Laid-Open Gazette 51 (1976)-125,468), saponified ethylene propylene acetate copolymer (Japanese Patent Laid-Open Gazette 52 (1977)-14,689), hydrolyzed acrylonitrile copolymer or acrylamide copolymer (Japan Patent Publication Show 53(1978)-15,959), and partially neutralized polyacrylic acid (Japanese Patent Publication Show 55(1980)-84,304), etc. Among them, the superabsorbent resin obtained by using acrylic acid and acrylate for cross-linking polymerization accounts for the largest part and is the most economical. The reason is that acrylic acid can be quickly obtained from the market, and the prepared superabsorbent resin has high water absorption capacity. And it has low manufacturing cost and the most economic benefits, so it has become the most popular superabsorbent resin.

The method of polymerizing acrylic acid and acrylate to form a superabsorbent resin has been successfully developed in many aspects, and many of them have been applied to industrial production. 42,466), on the conveyor belt, carry out polymerization reaction (Japanese Patent Laid-Open Publication 58 (1983)-49,714), carry out polymerization reaction (Japanese Patent Laid-Open Publication 57 (1982) in the kneader of the pulverized mixing blade -34,101), carry out reverse phase suspension polymerization (Japanese Patent Publication Show 59 (1984)-37,003), or monomer is sprayed or coated on the fiber matrix and carry out polymerization reaction (Japanese Patent Publication Show 62 (1987)-53, 309).

Most of the above-mentioned polymerization methods are to carry out free radical polymerization reaction of acid group-containing monomers, polymerization initiators, crosslinking agents and other reaction materials together to form gel-like solids, so that the entire polymerization reaction is difficult to control, and the soluble content is also high.

Contents of the invention

The purpose of the present invention is to provide a powdery, water-insoluble, superabsorbent resin capable of absorbing water, urine or blood, and a low soluble content. The polymerization process is relatively stable, and the reaction The heat is not too high, which improves product quality in addition to improving the operating environment.

In order to achieve the above object, the present invention provides a powdery, water-insoluble superabsorbent resin that can absorb water, urine or blood and has a low content of soluble matter. Its manufacturing method includes the following steps:

1) Retain an aqueous solution of an acid-group-containing monomer with a neutralization rate of more than 50 mole% and a polymerization initiator in the pipeline and conduct a pre-polymerization reaction to obtain a viscous prepolymer, and the acid-group-containing monomer is selected from acrylic acid or meth Acrylic acid or 2-propenylamine-2-methylpropanesulfonic acid or mixtures thereof;

2) Add long-chain, highly hydrophilic multi-epoxy compounds to the viscous prepolymer, and use light-initiated polymerization to further generate gel-like solids;

3) Drying, crushing and screening with hot air at a temperature of 100-250°C;

4) Surface crosslinking agent coating treatment;

5) Heating surface treatment at a temperature of 80-230°C;

6) Add inert inorganic salt powder.

According to the manufacturing method, the viscous prepolymer has a viscosity of 10-10000 centipoise (cps).

In the production method, the polymerization initiator can be a thermal decomposition initiator or a redox initiator.

In the described manufacturing method, its thermal decomposition type initiator can be hydrogen peroxide, hydrogen peroxide, di-tertiary butyl peroxide, peroxide amide or persulfate (ammonium salt, alkali metal salt) and other peroxides substances, or 2,2'-azobis(2-amidinopropane) dihydrochloride, 2.2'-azobis(N,N-dimethylisobutylamidine) dihydrochloride and other azo Nitrogen initiators.

In the production method, the redox initiator can be acidic sulfite, thiosulfate, ascorbic acid, ferrous sulfate or persulfate.

In the above-mentioned manufacturing method, the pipeline can be a pipeline with inert gas, a pipeline with helical blades inside, a pipeline equipped with fillers to help mixing effects, or a gas-liquid static mixer.

In the manufacturing method, the temperature of the prepolymerization reaction is 5-80°C.

In the manufacturing method, the prepolymerization reaction time is 0.5-16 hours.

In the manufacturing method, the photoinitiated polymerization is generally completed within 10-300 seconds, preferably within 30-60 seconds.

In the described manufacturing method, its long-chain epoxy compound can be sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol Alcohol diglycidyl ether, diglycerol polyglycidyl ether, etc.

According to the manufacturing method, the particle size distribution range after screening is between 0.05mm and 1mm.

In the said production method, the surface crosslinking agent is polyhydric alcohol, or polyethylene glycol diglycidyl ether, or alkylene carbonate or a mixture thereof.

In the manufacturing method, the range of adding the surface cross-linking agent is 0.005-5.0 wt%.

In the production method, the inert inorganic salt powder can be aluminum sulfate, or aluminum oxide, or magnesium oxide, or calcium oxide, or kaolin, or silicon dioxide, or calcium carbonate, or magnesium carbonate, etc., or a mixture thereof.

In the manufacturing method, the addition range of the inert inorganic salt powder is 0.01-4.0 wt%.

The above-mentioned pre-polymerization reaction can be carried out in a pre-polymerization reactor, and this reactor must have the function of making the raw materials of the polymerization reaction mix uniformly and carry out pre-polymerization. In addition to the vertical reaction tank generally equipped with stirring paddles, the pre-polymerization reactor can also use a horizontal cylindrical container, the center of which is equipped with a stirring paddle for the material to flow in one direction, a single screw or parallel twin-screws , so that it can ensure that the reaction materials move forward in one direction without backflow, thereby avoiding the formation of gel-like solids caused by the polymerization reaction materials staying in the reactor for too long. The above-mentioned type of reactor usually adopts the mode of feeding in batches, which is not conducive to industrial production. In view of the above, the present invention is a method for continuously producing a superabsorbent resin having a low soluble content, characterized in that a monomer solution is retained in a pipeline, and a polymerization initiator can be added to the pipeline to make the acid-containing Radical monomers undergo free radical polymerization to become viscous polymers. After the viscous prepolymer is mixed with the multi-component epoxy compound, it can be continuously added to the belt reactor, and above it, use various high-intensity light sources (such as mercury lamps, halogen lamps, infrared rays or γ-rays, etc.) The light-initiated polymerization reaction mode makes it a gel-like solid.

The above-mentioned feature is that the partially neutralized acrylate is used to stay in the pipeline, and the polymerization initiator can be added into the pipeline to make the acid group-containing monomer undergo free radical polymerization to become a viscous polymer. The viscous prepolymer is then mixed with a bridging agent and reacted with light to make it into a gel-like solid. Pre-polymerization in the pipeline saves space compared with general vertical reaction tanks or cylindrical containers, and it can also ensure the first-in-first-out principle of the aqueous solution of reactive monomers, so that non-reactive monomers remain in the pipeline during the pre-polymerization process, thereby reducing A case of excessive polymerization occurs. The residence time of the reaction monomer aqueous solution in the pipeline is one of the important factors to control the prepolymerization reaction. If the residence time is longer, the prepolymerization reaction will be more complete, the viscosity and molecular weight of the prepolymer will be higher, and the soluble content of the finished product will be higher. Low, but it is more prone to excessive polymerization in the pipeline; if the residence time is short, the viscosity and molecular weight of the prepolymer are lower, and the soluble content of the finished product is higher, but the chance of excessive polymerization is less. In addition, the mixing uniformity of the aqueous monomer solution and the polymerization initiator, and even the prepolymer and the bridging agent before the photoreaction is also an important factor affecting the prepolymerization reaction and the photoreaction. In order to improve the mixing effect of the above-mentioned fluids, the following methods can generally be used: (1) Inert gas is introduced into the pipeline. Such as: nitrogen, or carbon dioxide, or helium, or neon, or a mixture thereof. In the industry, nitrogen or carbon dioxide or their mixed gases are usually used in order to save costs and consider easy access. In addition, the pressure of the inert gas must be higher than the pressure in the pipeline, so that the inert gas can be smoothly injected into the pipeline containing the monomer aqueous solution to achieve the mixing effect of the various reaction fluids. (2) Install spiral blades in the pipeline or have a mixing effect Filling such as: Raschig ring, or wave ear ring, (3) use a vapor-liquid static mixer.

In addition to acrylic acid, other water-soluble monomers with unsaturated double bonds can be used for the acid group-containing monomers required for the production of superabsorbent resins in the present invention, such as: methacrylic acid, or maleic acid, or fumaric acid , or 2-propenylamine-2-methylpropanesulfonic acid, etc. There are no specific restrictions on the selection of monomers. Only one type can be used, and multiple monomers can also be used together. Other hydrophilic monomers with unsaturated double bonds can also be added according to the situation, such as: acrylamide, methacrylamide , 2-hydrocarbyl ethyl acrylate, 2-hydrocarbyl ethyl methacrylate, methyl acrylate, ethyl acrylate, dimethylamine acrylamide, acrylamide trimethylammonium chloride, but the amount added is not to damage the superabsorbent resin The physical properties are the principle.

Before free radical polymerization, the concentration of monomer aqueous solution should be controlled between 20wt% and 55wt%, and the appropriate concentration is between 30wt% and 45wt%. When the concentration is below 20wt%, the hydrated body after polymerization is too soft It is viscous and unfavorable to mechanical processing. The added concentration is above 55wt%, which is close to the saturation concentration.

The carboxylic acid group of the acid group-containing monomer should be partially neutralized to control the pH value of the finished product, making it neutral or slightly acidic. The neutralizer is lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium carbonate, sodium carbonate , potassium carbonate, lithium bicarbonate, sodium bicarbonate, potassium bicarbonate and ammonia. The carboxylic acid group of the acid group-containing monomer will be partially neutralized into lithium salt, sodium salt, potassium salt, ammonium salt or two or more mixed salts, the neutralization concentration molar percentage is 45mol% to 85mol%, and the appropriate concentration is 50mol % to 75mol%, the pH value of the finished product will be low when the neutralization concentration molar percentage is below 45mol%, and the pH value of the finished product will be high when the neutralization concentration molar percentage is above 85mol%, if the pH value of the finished product is not neutral or slightly When it is acidic, it is not suitable or safe for accidental contact with the human body.

The prepolymerization reaction starts with the decomposition of the polymerization initiator to generate free radicals. Polymerization initiator can be selected thermal decomposition type starter, suitable thermal decomposition type initiator has peroxide, such as: hydrogen peroxide, two-tertiary butyl peroxide, peroxide amide or persulfate (ammonium Salt, alkali metal salt), etc., and azo compounds such as: 2.2'-Azobis(2-amidinopropane) dihydrochloride; reducing agents can also be used to make redox initiators, such as: Acidic sulfite, thiosulfate, ascorbic acid or ferrous salt; or a combination of redox initiators and thermal decomposition initiators. First, the redox initiators react first to generate free radicals. When free radicals The transfer to the monomer will initiate the polymerization reaction, because a large amount of heat will be released during the polymerization reaction and the temperature will rise. When the temperature reaches the decomposition temperature of the thermal decomposition type initiator, the second stage of heat will be triggered. The decomposition of the decomposition initiator makes the whole polymerization reaction more complete. Generally, the appropriate amount of free radical polymerization initiator is 0.001wt% to 10wt% by weight (based on the weight of the neutralized acrylate), and the more appropriate amount is between 0.1wt% and 5wt%, and the weight percentage is 0.001wt% % below, the reaction is too slow and unfavorable to economic benefits; when the weight percentage is used above 10wt%, the reaction is too fast and the heat of reaction is not easy to control and is easy to be excessively polymerized to form a gel-like solid.

A cross-linking agent should be added to the viscous prepolymer before photoinitiation polymerization. The cross-linking agent can be a compound with two or more unsaturated double bonds, such as: N, N-bis(2-propenyl ) amine, N, N'-methylenebisacrylamide, N, N'-methylenebismethacrylamide, acrylate, ethylene glycol diacrylate, polyethylene glycol diacrylate, ethylene diacrylate Alcohol Dimethacrylate, Polyethylene Glycol Dimethacrylate, Glycerin Triacrylate, Glycerol Trimethacrylate, Glycerin Triacrylate or Trimethacrylate with Ethylene Oxide Added, Trimethylolpropane Added Triacrylate or trimethacrylate of ethylene oxide, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, N,N,N-tris(2-propenyl)amine, ethylenediacrylate Alcohol ester, dipropylene triethylene glycol ester, etc., and compounds with two or more epoxy groups can also be selected, such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, ethylene glycol diglycidyl ether , Diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, diglycerol polyglycidyl ether, etc. After the free radical reaction, the superabsorbent resin can have a proper degree of crosslinking, so that the colloid of the superabsorbent resin can have proper processability. The radical polymerization crosslinking agent can be used alone or in combination of two or more. The appropriate additive amount of free radical polymerization crosslinking agent is between 0.001wt% and 5wt% by weight (based on the total solid content of the reactant), and the more appropriate amount is between 0.01wt% and 3wt%. When the amount is less than 0.001wt%, the hydrated body after polymerization is too soft and viscous, which is not conducive to mechanical processing, and when the additive amount is more than 5wt%, the water absorption is too low, which reduces the performance of the resin.

The viscous prepolymer can be subjected to photoinitiation polymerization on a conveyor belt reactor or a horizontal reactor equipped with stirring blades, and the prepared superabsorbent gel is first cut into a particle size of 20mm or less by a grinder Small gel, preferably less than 10mm, and then dried.

The drying temperature can be dried at 100°C to 250°C, and the drying temperature is preferably 120°C to 180°C. If the drying temperature is below 120°C, the drying time will not be economical if the drying time is too long. Drying above 180°C makes the cross-linking agent carry out cross-linking reaction earlier, so that in the subsequent drying process, the residual monomer cannot be effectively removed due to too high cross-linking, so as to achieve the effect of reducing the low residual monomer.

After drying, it is crushed, screened to fix the particle size, and then coated with a surface cross-linking agent. Screening and fixed particle size is preferably between 0.06mm and 1.00mm, preferably between 0.10mm and 0.850mm. Fine powder with a particle size below 0.06mm will increase the dust of the finished product, and particles with a particle size above 1.00mm will slow down the water absorption rate of the finished product.

The water-absorbent resin is an insoluble hydrophilic polymer, and the resin has a uniform bridging structure inside. Generally, in order to improve the quality, such as: increase the absorption rate, increase the colloid strength, improve the anti-caking property, liquid permeability, etc., will Further bridging is carried out on the surface of the resin. This surface cross-linking treatment uses a multi-functional cross-linking agent that can react with acid groups. Many patents have proposed before this; such as: dispersing super absorbent resin and cross-linking Surface crosslinking treatment (JP-A-56-131608, JP-A-57-44627, JP-A-58-42602, JP-A58-117222) using inorganic powder to directly mix crosslinking agent with organic solvent The crosslinking agent solution is mixed with superabsorbent resin for treatment (JP-A60-163956, JP-A-60-255814), and after adding the crosslinking agent, it is treated with steam (JP-A-1-113406), using organic solvents, water and Polyol for surface treatment (JP-A-63-270741, JP-A-64-50707, JP-A-1-292004) using organic solution, water, ether compound (JP-A-2-153903) etc.; although these surface treatment methods can increase the absorption rate and increase the water absorption rate under pressure, they will cause excessive reduction in retention and reduce the performance of practical applications.

According to the present invention, the crosslinking agent that can react simultaneously when the surface treatment is selected after the fixed particle size can be a polyalcohol such as: glycerol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol Alcohol, propylene glycol, 1,4 butanediol, trialkylmethylpropane, sorbitol, etc.; or polyamines such as: ethylenediamine, diethylenediamine, triethylenediamine, polyethylenediamine; or can be used Compounds with two or more epoxy groups such as: sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol Diglycidyl ether, diglycerol polyglycidyl ether, etc.; alkylene carbonate such as ethylene glycol carbonate, 4-methyl-1,3-dioxolane-2-one can also be used , 4,5-dimethyl-1,3-dioxolane-2-one, 4,4-dimethyl-1,3-dioxolane-2-one, 4-ethane Base-1,3-dioxolan-2-one, 1,3-dioxan-2-one, 4,6-dimethyl-1,3-dioxane -2-one or 1,3-dioxepan-2-one, etc. The use of the crosslinking agent at the surface can be used alone or in combination of two or more. The appropriate additive amount of the crosslinking agent at the surface is between 0.001wt% and 10wt% by weight (based on the total solid content of the reactant), and the more appropriate amount is between 0.005wt% and 5wt%, and the crosslinking agent at the surface When the additive amount is less than 0.001 wt%, the effect cannot be exhibited, and when the additive amount of the crosslinking agent on the surface is more than 10 wt%, the water absorption is too low and the performance of the resin is reduced.

When the surface cross-linking agent is coated, the addition of the surface cross-linking agent can be directly added to the surface cross-linking agent, or added as a surface cross-linking agent aqueous solution, or added as a surface cross-linking agent hydrophilic organic solvent aqueous solution, hydrophilic Water-based organic solvents such as methanol, ethanol, propanol, isobutanol, acetone, methyl ether, diethyl ether, etc. are not particularly limited, as long as they can form a solution, methanol and ethanol are preferred. When the surface crosslinking agent is added, inert inorganic salt powder can be added to the superabsorbent resin to help the solution disperse. The inert inorganic salt powder can be aluminum sulfate, or silicon dioxide, or aluminum oxide, or magnesium oxide, etc. or a mixture thereof. Among them, aluminum sulfate and silicon dioxide are preferred. The addition range of the inert inorganic salt powder is between 0.005wt% and 10.0wt%, preferably 0.01wt% to 4.0wt%.

After coating the surface crosslinking agent, heat treatment at 80° C. to 230° C. enables the surface crosslinking agent to undergo a crosslinking reaction and the internal crosslinking agent to undergo a crosslinking reaction to achieve the effect of the present invention. If the processing temperature is below 80°C, the cross-linking reaction time is too long, which is not economical. When the processing temperature is ≥230°C, the resin is easy to deteriorate and affect the quality. As for the treatment time, it is suitable to be 2-150 minutes, which is adjusted according to the treatment temperature. The higher the temperature, the shorter the time, and the lower the temperature, the longer the time.

Since the superabsorbent resin has the phenomenon of agglomeration after moisture absorption, in order to avoid the agglomeration after moisture absorption of the superabsorbent resin used in high-humidity areas, which will cause rough processing, the surface of the superabsorbent resin is generally coated with inert inorganic salt powder or Surfactant, making the surface slightly lipophilic so that the superabsorbent resin retains the characteristics of not being easy to agglomerate after moisture absorption. The inert inorganic salt powder can be selected from aluminum sulfate, or silicon dioxide, or aluminum oxide, or magnesium oxide, or oxide Calcium, or kaolin, or calcium carbonate, or magnesium carbonate, etc. or their mixture; usually the amount of this inert inorganic salt powder added is related to the particle size of the inorganic salt powder, if the particle size is small, the specific surface area of the inorganic salt powder is larger , so the effective inert inorganic salt powder consumption can be less, and its inert inorganic salt powder addition range is between the weight ratio percentage 0.005wt% to 10.0wt%, wherein with 0.01wt% to 4.0wt% better, inert inorganic salt powder The particle size is 0.001μM to 100μM. If the inorganic salt powder with particles smaller than 0.001μM is used, the cost will be too high and it is not conducive to industrial production. If the inorganic salt powder with particles larger than 100μM is used, the addition amount will affect the absorption of super absorbent resin. question. Inert inorganic salt powder can be added alone or along with surfactants or organic compounds with viscosity. The surfactants or organic compounds with viscosity can be selected from non-ionic surfactants with an HLB value of 12 or more, or water-soluble anionic surfactants , or cationic surfactants, or anionic and positive amphoteric surfactants, or mixtures thereof, usually surfactants or viscous organic compounds can use glycerin, ethylene glycol, hexyl alcohol, polyoxyethylene alcohol, or polyethylene glycol Alcohol, or polyethylene glycol stearate, or polyethylene glycol hexaester stearate, or polyoxyethylene nonphenylene ether, or polyoxyethylene octylphenyl ether, or polyoxyethylene dodecylphenyl ether, or The surfactant or organic compound with viscosity such as polyoxyethylene alkyl ether or polyoxyethylene lauryl ether can be formulated into an aqueous solution or added separately, and the appropriate amount of surfactant or organic compound with viscosity is 0.001% by weight It is between wt% and 5wt% (based on the total solid content of the reactants), and the more appropriate weight percentage is between 0.01wt% and 3wt%.

The present invention provides a method for continuous production of superabsorbent resin with low soluble content, which is characterized in that the reaction monomer and polymerization initiator are pre-polymerized in the pipeline, and the prepolymer and epoxy compound are then Upon exposure to light to form a gel-like solid. Through this production method, the viscosity of the prepolymer relative to the liquid reaction material is significantly increased, the fluidity is reduced, and it is easier to match with the subsequent belt reactor, and the stability of the entire polymerization reaction is improved, and the reaction heat is not too high. The important thing is that the use of the pipeline reactor not only saves space, but also ensures the first-in-first-out principle of the reaction fluid, so as to achieve the purpose of continuous production. In addition to improving the production operability and working environment, the manufacturing method of the superabsorbent resin provided by the present invention also greatly improves the product quality, and especially has obvious effects on reducing the content of soluble matter.

In order to show the characteristics of the low soluble matter content of the superabsorbent resin of the present invention, the determination steps of its soluble matter content are as follows: first weigh 0.5 g of the super absorbent resin, then add 185 g of 0.9% saline, and stir at 500 rpm After one hour, the SAP extract was filtered off with filter paper. Finally, 20 g of the extract was weighed, first titrated with 0.1N NaOH, and then back-titrated with 0.1N HCl to obtain the content of SAP solubles.

Detailed ways

The following examples illustrate the present invention, but the patent and technical scope of the present invention are not limited by these examples.

Embodiment one:

(1) First add 1760 parts by weight of acrylic acid and 2263.7 parts by weight of water in the neutralization tank, then slowly add 1476.3 parts by weight of aqueous sodium hydroxide solution (concentration: 45%) in the above-mentioned acrylic acid solution under ice bath. At this time, an aqueous solution with a monomer concentration of 38.6 wt % was obtained, in which 68 mol % of acrylic acid was neutralized into sodium acrylate.

(2) After the neutralization program is completed, adjust the temperature of the sodium acrylic acid sodium salt solution for partial neutralization to about 20°C.

(3) Adjust the flow rate of the above-mentioned monomer solution to 100 liters/hour so that it passes through a stainless steel pipe with a diameter of 5 cm and a total length of 26.35 meters. In addition, a stainless steel tube with a diameter of 0.5 cm and a diameter of 0.9 cm is respectively connected to the sides at 5 cm and 10 cm from the stainless steel tube inlet end. The former imports nitrogen, and the flow control is 200 liters/hour, and the latter then passes through potassium persulfate/sodium bisulfite=1/1 (weight ratio), and the flow control is 2 milliliters/hour. The temperature of prepolymerization and reaction was controlled at 20° C., and the viscosity of the final prepolymer was 80 centipoise (cps).

(4) Two stainless steel pipes with a diameter of 0.9 cm are connected to the side 85 cm away from the outlet end of the pipeline. One is introduced into azobisisoheptapterol, and the flow rate is controlled at 20 ml/hour, while the other is introduced into glycerol polymer. Ethylene glycol triglycidyl ether (n=7), the flow rate was controlled at 15 ml/hour.

(5) Put the reaction fluid described in (4) on the conveyor belt, and a high-intensity ultraviolet irradiation machine is installed above the conveyor belt, and the above-mentioned mixed liquid is irradiated with the device for 20 seconds (illuminance=13.9J/cm ² ) to make it cross-linked The reaction forms a colloid.

(6) Cut into gel bodies with a diameter of 2 mm or less by using a cutter mincer.

(7) Dry at 130° C. for 2 hours; use a sieve to sieve with a fixed particle size of 0.1 mm to 0.85 mm to obtain a powdery superabsorbent resin.

(8) Weigh 100g of the superabsorbent resin, add 1g of aluminum sulfate powder, and after mixing evenly, add 4g of ethylene glycol carbonate/water/methanol=1/1/1 (weight ratio) Heat treatment for 10 minutes.

(9) After cooling, add 1 g of calcium carbonate (product name of Formosa Plastics: NS-2000) and 2 g of 20% glycerin aqueous solution, and mix evenly to obtain a high-performance superabsorbent resin. Measured holding power = 30.5g/g, water absorption capacity under 49g/cm ² pressure = 22.1g/g, soluble matter content = 10.1%.

Embodiment two:

(1) Example 1 was repeated, but the total length of the stainless steel pipe was changed to 52 meters long, and the viscosity of the obtained prepolymer was 210 cps. The holding power of the superabsorbent resin is 32.7g/g, the water absorption capacity under the pressure of 49g/cm ² is 23.9g/g, and the soluble matter content is 8.7%.

Embodiment three:

(1) Example 1 was repeated, but the total length of the stainless steel pipe was changed to 103 meters long, and the viscosity of the obtained prepolymer was 370 cps. The holding power of the superabsorbent resin is 35.4g/g, the water absorption capacity under the pressure of 49g/cm ² is 25.2g/g, and the soluble matter content is 7.2%.

Embodiment four:

(1) First add 1760 parts by weight of acrylic acid and 2263.7 parts by weight of water in the neutralization tank, then slowly add 1476.3 parts by weight of aqueous sodium hydroxide solution (concentration: 45%) in the above-mentioned acrylic acid solution under ice bath. At this time, an aqueous solution with a monomer concentration of 38.6 wt % was obtained, in which 68 mol % of acrylic acid was neutralized into sodium acrylate.

(2) After the neutralization program is completed, adjust the temperature of the sodium acrylic acid sodium salt solution for partial neutralization to about 20°C.

(3) Adjust the flow rate of the above-mentioned monomer solution to 100 liters/hour so that it passes through a stainless steel pipe with a diameter of 5 cm and a total length of 26.35 meters filled with Raschig rings with a diameter of 5 mm. In addition, a stainless steel tube with a diameter of 0.5 cm and a diameter of 0.9 cm is respectively connected to the sides at 5 cm and 10 cm from the inlet end of the stainless steel tube. The former imports nitrogen, and the flow control is 200 liters/hour, and the latter then passes through potassium persulfate/sodium bisulfite=1/1 (weight ratio), and the flow control is 2 milliliters/hour. The temperature of prepolymerization and reaction was controlled at 20°C, and the viscosity of the final prepolymer was 115cps.

(4) Two stainless steel pipes with a diameter of 0.9 cm are connected to the side 85 cm away from the outlet end of the pipeline. One is introduced into azobisisoheptapterol, and the flow rate is controlled at 20 ml/hour, while the other is introduced into glycerol polymer. Ethylene glycol triglycidyl ether (n=7), the flow rate was controlled at 15 ml/hour.

(5) Put the reaction fluid described in (4) on the conveyor belt, and a high-intensity ultraviolet irradiation machine is installed above the conveyor belt, and the above-mentioned mixed liquid is irradiated with the device for 20 seconds (illuminance=13.9J/cm ² ) to make it cross-linked The reaction forms a colloid.

(6) Cut into gel bodies with a diameter of 2 mm or less by using a cutter mincer.

(7) Dry at 130° C. for 2 hours; use a sieve to sieve with a fixed particle size of 0.1 mm to 0.85 mm to obtain a powdery superabsorbent resin.

(8) Weigh 100g of the superabsorbent resin, add 1g of aluminum sulfate powder, and after mixing evenly, add 4g of ethylene glycol carbonate/water/methanol=1/1/1 (weight ratio) Heat treatment for 10 minutes.

(9) After cooling, add 1 g of calcium carbonate (product name of Formosa Plastics: NS-2000) and 2 g of 20% glycerin aqueous solution, and mix evenly to obtain a high-performance superabsorbent resin. Measured holding power = 31.3g/g, water absorption capacity under 49g/cm ² pressure = 23.5g/g, soluble matter content = 8.9%.

Embodiment five:

(1) Example 1 was repeated, but the total length of the stainless steel pipe was changed to 52 meters, and the viscosity of the obtained prepolymer was 302 cps. The holding power of the superabsorbent resin is 33.8g/g, the water absorption capacity under the pressure of 49g/cm ² is 24.5g/g, and the soluble matter content is 6.4%.

Embodiment six:

(1) Example 1 was repeated, but the total length of the stainless steel pipe was changed to 103 meters long, and the viscosity of the obtained prepolymer was 515 cps. The holding power of the superabsorbent resin is 36.7g/g, the water absorption capacity under the pressure of 49g/cm ² is 24.3g/g, and the soluble matter content is 5.3%.

Embodiment seven:

(1) First add 1760 parts by weight of acrylic acid and 2263.7 parts by weight of water in the neutralization tank, then slowly add 1476.3 parts by weight of aqueous sodium hydroxide solution (concentration: 45%) in the above-mentioned acrylic acid solution under ice bath. At this time, an aqueous solution with a monomer concentration of 38.6 wt % was obtained, in which 68 mol % of acrylic acid was neutralized into sodium acrylate.

(2) After the neutralization program is completed, the temperature of the partially neutralized sodium acrylic acid salt solution is controlled to be about 20° C. by temperature adjustment.

(3) Adjust the flow rate of the above-mentioned monomer solution to 100 liters/hour, so that it passes through a gas-liquid static mixer (brand: NORITAKE) with a diameter of 5 cm and a total length of 27.2 meters. The length is 30 cm. In addition, a stainless steel tube with a diameter of 0.5 cm and a diameter of 0.9 cm is respectively connected to the sides at 5 cm and 10 cm from the inlet end of the stainless steel tube. The former imports nitrogen, and the flow control is 200 liters/hour, and the latter then passes through potassium persulfate/sodium bisulfite=1/1 (weight ratio), and the flow control is 2 milliliters/hour. The temperature of prepolymerization and reaction was controlled at 20° C., and the viscosity of the final prepolymer was 95 cps.

(4) Two stainless steel pipes with a diameter of 0.9 cm are connected to the side 85 cm away from the outlet end of the pipeline. One is introduced into azobisisoheptapterol, and the flow rate is controlled at 20 ml/hour, while the other is introduced into glycerol polymer. Ethylene glycol triglycidyl ether (n=7), the flow rate was controlled at 15 ml/hour.

(5) Put the reaction fluid described in (4) on the conveyor belt, and a high-intensity ultraviolet irradiation machine is installed above the conveyor belt, and the above-mentioned mixed liquid is irradiated with the device for 20 seconds (illuminance=13.9J/cm ² ) to make it cross-linked The reaction forms a colloid.

(6) Cut into gel bodies with a diameter of 2 mm or less by using a cutter mincer.

(7) Dry at 130° C. for 2 hours; use a sieve to sieve with a fixed particle size of 0.1 mm to 0.85 mm to obtain a powdery superabsorbent resin.

(8) Weigh 100g of the superabsorbent resin, add 1g of aluminum sulfate powder, and after mixing evenly, add 4g of ethylene glycol carbonate/water/methanol=1/1/1 (weight ratio) Heat treatment for 10 minutes.

(9) After cooling, add 1 g of calcium carbonate (product name of Formosa Plastics: NS-2000) and 2 g of 20% glycerin aqueous solution, and mix evenly to obtain a high-performance superabsorbent resin. Measured holding power = 31.2g/g, water absorption capacity under 49g/cm ² pressure = 23.0g/g, soluble matter content = 6.1%.

Embodiment eight:

(1) Example 1 was repeated, but the total length of the stainless steel pipe was changed to 53 meters, and the viscosity of the obtained prepolymer was 285 cps. The holding power of the superabsorbent resin is 34.1g/g, the water absorption capacity under the pressure of 49g/cm ² is 24.9g/g, and the soluble matter content is 5.1%.

Embodiment nine:

(1) Example 1 was repeated, but the total length of the stainless steel pipe was changed to 103 meters long, and the viscosity of the obtained prepolymer was 410 cps. The holding power of the superabsorbent resin is 35.8g/g, the water absorption capacity under the pressure of 49g/cm ² is 26.4g/g, and the soluble matter content is 3.8%.

Comparative example one:

(1) Repeat Example 1, but the reaction monomer solution described in step (3) is injected into a vertical reaction tank under nitrogen gas (flow control at 200 liters/hour) and reacts under high-speed stirring for about 30min, and the obtained The viscosity of the prepolymer was 140cps, but after discharging, it was found that there was a little polymer on the stirring blade. The holding power of the superabsorbent resin is 33.4g/g, the water absorption capacity under the pressure of 49g/ ^cm2 is 23.1g/g, and the soluble matter content is 13.7%.

Comparative example two:

(1) Repeat Example 1, but the reaction monomer solution described in step (3) is injected into a vertical reaction tank under nitrogen flow (flow control at 200 liters/hour) and reacts under high-speed stirring for about 60min, and the obtained The viscosity of the prepolymer was 255cps, but after discharging, it was found that some polymer remained in the stirring blade and the reaction tank. The holding power of the superabsorbent resin is 36.1g/g, the water absorption capacity under the pressure of 49g/cm ² is 23.4g/g, and the soluble matter content is 13.5%.

Claims (12)

1, a kind of powdery, water insoluble can absorb the low super absorbent resin of water liquid, urine or blood and solubles content, and its manufacture method may further comprise the steps:

1) with 50 moles of neutralization ratio more than the % contain acidic group monomer solution and initiators for polymerization in pipeline, be detained and carry out the prepolymerization reaction and sticky prepolymer, and it contains the acidic group monomer and is selected from acrylic or methacrylic acid or its mixture;

Described initiators for polymerization consumption with in and acrylate weight be that benchmark is between weight percent 0.001wt% to 10wt%;

Described pipeline is: be connected with the pipeline of rare gas element, the pipeline that includes screw-blade, installing and help the pipeline or the gas-liquid static mixer of mixed effect weighting material;

2) the polynary epoxy compounds that adds long-chain, high-hydrophilic utilizes the light initiation polymerization mode further to generate gelatinous solid in sticky prepolymer;

Described polynary epoxy compounds is: sorbyl alcohol polyglycidyl ether, polyglycerol polyglycidyl ether, ethylene glycol diglycidylether, Diethylene Glycol diglycidylether, polyethyleneglycol diglycidylether or two glycerol polyglycidyl ether;

3) carry out drying, pulverizing, screening with temperature 100-250 ℃ hot blast;

4) surface crosslinking agent coating processing;

The additive capacity of surface crosslinking agent is that benchmark is between weight percent 0.001wt% to 5wt% with the total solid of reactant;

5) temperature 80-230 ℃ of heating surface handled;

6) add the inert inorganic salt powder.

2. according to the super absorbent resin of claim 1, the viscosity of its sticky prepolymer is 10-10000cps.

3. according to the super absorbent resin of claim 1, its initiators for polymerization is: the ammonium salt of hydrogen peroxide, two-tert-butyl peroxide, peroxidation acid amides or persulphate and an alkali metal salt, 2, two (2-amidine propane) dihydrochlorides of 2 '-azo-group, acid accumulator sulfite, thiosulphate, xitix or ferrous sulfate.

4. according to the super absorbent resin of claim 1, the temperature of its prepolymerization reaction is 5-80 ℃.

5. according to the super absorbent resin of claim 1, its prepolymerization reaction times is 0.5-16 hour.

6. according to the super absorbent resin of claim 1, its light initiation polymerization is finished in second at 10-300.

7, according to the super absorbent resin of claim 6, its light initiation polymerization time is 30-60 second.

8. according to the super absorbent resin of claim 1, the particle size distribution range after its screening is between 0.05mm to 1mm.

9. according to the super absorbent resin of claim 1, its surface crosslinking agent is polyvalent alcohol or polyethyleneglycol diglycidylether or alkylene carbonate or its mixture.

10. according to the super absorbent resin of claim 1, it is 0.005-5.0wt% at weight percent that its surface crosslinking agent adds scope.

11. according to the super absorbent resin of claim 1, its inert inorganic salt powder is: Tai-Ace S 150 or aluminum oxide or magnesium oxide or calcium oxide or kaolin or silicon-dioxide or lime carbonate or magnesiumcarbonate or its mixture.

12. according to the super absorbent resin of claim 1, it is 0.01-4.0wt% at weight percent that its inert inorganic salt powder adds scope.