CN101007858B - Production method of highly water-absorbing resin - Google Patents
Production method of highly water-absorbing resin Download PDFInfo
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- CN101007858B CN101007858B CN200610002806XA CN200610002806A CN101007858B CN 101007858 B CN101007858 B CN 101007858B CN 200610002806X A CN200610002806X A CN 200610002806XA CN 200610002806 A CN200610002806 A CN 200610002806A CN 101007858 B CN101007858 B CN 101007858B
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Abstract
The invention provides a method for preparing a high hydroscopicity resin, employing a high- efficiency and continuous sifting way, which can maintain stable production and increase productivity.
Description
Technical field
The present invention relates to a kind of high-level efficiency step sizing mode of super absorbent resin.Provide a kind of in more detail and when producing super absorbent resin, obtaining stay-in-grade super absorbent resin continuously under the situation the most fast by rotation or sifting machine, make the processing procedure of super absorbent resin more can keep stably manufactured, can increase the production efficiency of super absorbent resin again.
Background technology
Super absorbent resin is applied to water retention agent, the anti-dewdrop condensing agent in the material of construction and the material that removes moisture content in the oil of agricultural or gardening aspect widely, or the waterproof outer coating in the cable and sanitary product such as diaper, women sanitary articles, deserted wiping cloth etc., its purposes is quite big.
At this technos, the composition material of known super absorbent resin has starch-vinyl cyanide (hydrolyzed starchacrylonitrile) graftomer (day disclosure special permission communique clear 49 (1974)-43 of meeting the water decomposition type, 395), neutral starch-acrylic acid-grafted polymkeric substance (day disclosure special permission communique clear 51 (1976)-125,468), saponification ethene acetic acid-propylene ester copolymer (day disclosure special permission communique clear 52 (1977)-14,689), hydrolyzed acrylonitrile multipolymer or acrylamide copolymer (Japan's special permission communique clear 53 (1978)-15,959), and partly and polyacrylic acid (day disclosure is speciallyyed permit communique clear 55 (1980)-84,304) etc.Wherein in the raw material of starch-acrylonitrile grafting polymkeric substance,, can cause the decomposition of putrescibility, can't preserve for a long time because contain natural polymer-starch; Moreover its manufacture method is very complicated, so the preparation method of existing super absorbent resin accounts at most also economy the most with the super absorbent resin that uses vinylformic acid and acrylate to carry out the crosslinking polymerization gained.It is former because raw material-the vinylformic acid of acrylate multipolymer can be rapidly by buying on the market, and the super absorbent resin that makes has high water-retaining capacity, and have cheap for manufacturing cost and tool economic benefit and can not cause that putrescibility decomposes, so become the super absorbent resin of generalization.
The method that polymeric acrylic acid and acrylate form super absorbent resin can be made by several known methods, as aqueous solution polymerization reaction, anti-phase suspension polymerization, emulsion polymerization reaction or with the monomer sprinkling or be coated on methods such as carrying out polyreaction on the fibre substrate.In these methods, anti-phase suspension polymerization and emulsion polymerization reaction must be with an organic solvent, but the temperature in processing procedure if when effectively controlled polymerization reacts, organic solvent will cause the increase of reactive system increase in temperature and pressure, cause phenomenon on fire even blast, and then threaten factory building and operation site personnel's safety and cause problems such as environmental pollution, its finished product also has the doubt of organic solvent residual.
Improve the existing many inventions in the present technique field of the physical properties of super absorbent resin or the method for enhancing productivity, as: add a kind of one-level or secondary amine (day disclosure special permission communique clear 33 (1958)-2,646 with a day disclosure special permission communique clear 50 (1975)-40,689), and interpolation sulphite and hydrosulphite (United States Patent (USP) 2,960, No. 486 and 4,306, No. 955) to reduce level of residual monomers; Add a kind of polyvalent metal salt or multivalent metal hydroxides (day disclosure special permission communique clear 62 (1987)-0745), and add interfacial agent (No. 103,058, European patent) in gelinite and can reduce fine powder generating capacity in the process of lapping; Use polyvalent alcohol to be sprayed on absorbent resin surface (United States Patent (USP) 4,734, No. 478) and carry out surface treatment, reduce and reach the fine powder generating capacity; With an organic solvent, water and polyvalent alcohol carry out surface treatment (Japanese technical bulletin clear and 63 (1988)-270741, Japan's special permission communique clear 64 (1989)-50707), use organic solution, water, ether (ether) compound (JP-A-2-153903) can improve water absorbent rate under the uptake rate pressurize; Utilize pipeline to pass through whipping appts, and with polymerization starter and bridging agent importing pipeline, carry out method (the China's Mainland patent 1 of polyreaction, 498, No. 903), use the circulating air drying installation to improve drying efficiency, and adjust the shredder gap to increase mill efficiency (United States Patent (USP) 6,641, No. 064); But these improve the physical properties of super absorbent resin or the method for production efficiency, but do not improve the invention or the report of its screening efficiency, though be the polyreaction mode improvement, shredder grinding condition change or change that drying mode makes that drying efficiency improves etc. creation or method invention, if there is not high efficiency screening mode, all can reduce the performance of practical application greatly.
Summary of the invention
The manufacture method that the objective of the invention is to a kind of super absorbent resin, made super absorbent resin, be to carry out polyreaction to cause free radical, what it was required contains the acidic group monomer except that vinylformic acid, still can use other to have the water-soluble monomer that two keys are closed in insatiable hunger, as: methacrylic acid, Malin's acid, fumaric acid, 2-allylamine-2-methyl propane sulfonic acid etc.Monomer selects for use not specific limited to use a kind of only, also can merge multiple monomer uses together, also can depending on the circumstances or the needs of the situation add and have other hydrophilic monomer of unsaturated double-bond, as: acrylamide, Methacrylamide, vinylformic acid 2-alkyl ethyl ester, methacrylic acid 2-alkyl ethyl ester, methyl acrylate, ethyl propenoate, the dimethylamine acrylic acid-acrylamide, (United States Patent (USP)s 4 such as propylene dichloride amide group TMA (TriMethylAmine), 057, No. 521,4,062, No. 817,4,525, No. 527,4,286, No. 082 and 4,295, No. 987), but addition is a principle with the rerum natura of not destroying super absorbent resin.
Before carrying out Raolical polymerizable, monomer solution concentration should be controlled between weight percent 20wt% to 55wt%, proper concn is between the 30wt% to 45wt%, concentration is when weight percent 20wt% is following, the hydration colloid is too soft and the unfavorable mechanical workout of stickiness arranged after the polymerization, add concentration more than weight percent 55wt%, difficult allotment problem is arranged during too near saturation concentration and react that too fast response heat is too much wayward.
Contain the monomeric carboxylic acid group of acidic group and should partly neutralize with the pH value of control finished product, make to be neutrality or subacidity, neutralizing agent is sodium hydroxide, potassium hydroxide, yellow soda ash, salt of wormwood, sodium bicarbonate, saleratus and ammonia.Contain the monomeric carboxylic acid group of acidic group and partly be neutralized into sodium salt or sylvite or ammonium salt, in and the concentration molar percentage be 45mol% to 85mol%, be preferably 50mol% to 75mol%, in and the concentration molar percentage be that the pH value of 45mol% finished product when following is understood on the low side, in and the concentration molar percentage be that the pH value of 85mol% finished product when above is understood higher, finished product pH value is non-when being neutrality or subacidity, if all not too suitable also more dangerous when contacting with human body accidentally.
Carrying out Raolical polymerizable, in the preceding monomer solution, also can add water-soluble polymer to reduce cost or to obtain special rerum natura, these water-soluble polymers are as partly saponification or fully saponified polyvinyl alcohol, polyoxyethylene glycol, polyacrylic acid, polyacrylamide, starch or starch derivative such as methylcellulose gum, the vinylformic acid methylcellulose gum, polymkeric substance such as ethyl cellulose; The molecular weight of these water-soluble polymers is not particularly limited, and wherein preferable water-soluble polymer is a starch, partly saponification or fully saponified polyvinyl alcohol etc. are used alone or as a mixture.The suitable weight percent that super absorbent resin contains these water-soluble polymers is 0 to 20wt%, but it is preferable with 0 to 10wt%, 0 to 5wt% is good especially, and the super absorbent resin composition that effectively absorbs water is on the low side when add surpassing 20wt%, can influence rerum natura and make the water-retaining capacity variation.
Before carrying out Raolical polymerizable, should add the Raolical polymerizable linking agent earlier in unreacted monomer solution, the optional usefulness of this Raolical polymerizable linking agent has the compound of two or more unsaturated double-bonds, as: N, two (2-propenyl) amine of N-, N, N '-methyne bisacrylamide, N, the two Methacrylamides of N '-methyne, vinylformic acid propylene ester, glycol diacrylate, polyethyleneglycol diacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, glycerol tri-acrylate, the glycerine trimethacrylate, the triacrylate or the trimethacrylate of glycerine additional ring oxidative ethane, the triacrylate or the trimethacrylate of trihydroxymethyl propane additional ring oxidative ethane, the trihydroxymethyl propane trimethacrylate, the trihydroxymethyl propane triacrylate, N, N, N-three (2-propenyl) amine, ethylene glycol diacrylate, two propylene triethyleneglycol ester etc., also optional usefulness has the compound of two or more epoxy group(ing), as the sorbyl alcohol polyglycidyl ether, the polyglycerol polyglycidyl ether, ethylene glycol diglycidylether, the Diethylene Glycol diglycidylether, polyethyleneglycol diglycidylether, two glycerol polyglycidyl ethers etc.These linking agents just can make super absorbent resin have suitable degree of crosslinking after carrying out free radical reaction, and make the super absorbent resin colloid that suitable processibility be arranged.The Raolical polymerizable linking agent can be used alone or mixed use of two or more, its suitable additive amount is (is benchmark with the total solid of reactant) between weight percent 0.001wt% to 5wt%, and more suitable consumption is weight percentage between 0.01wt% to 3wt%.Additive capacity hydrated body after the following polymerization of weight percent 0.001wt% is too soft and the unfavorable mechanical workout of stickiness is arranged, and additive capacity water-absorbent when weight percent 5wt% is above is too low, reduces resin property.If increase the water regain of super absorbent resin, also can select bridging agent for use than long-chain, as: United States Patent (USP) the 5th, 506, No. 324 2-ethyl glycerol three polyethylene glycol acrylate of adding long-chain of reporting, the characteristic of this long-chain linking agent will effectively promote the confining force of super absorbent resin.
Polyreaction is begun by the decomposition generation free radical of Raolical polymerizable initiator.Free radical starting agent can be selected thermolysis type initiator for use, the thermolysis type initiator that is fit to has superoxide, as: hydrogen peroxide, two-Di tributyl superoxide, peroxidation acid amides or persulphate (ammonium salt, an alkali metal salt) etc., and azo-compound as: 2, two (2-amidine propane) dihydrochlorides, 2 of 2 '-azo-group, two (N, N-two the stretches the methyl NSC 18620) dihydrochlorides of 2 '-azo-group; Also can use reductive agent, making becomes the oxidation-reduction type initiator, as: acid accumulator sulfite, thiosulphate, xitix or ferrous salt; Or with oxidation-reduction type initiator and thermolysis type initiator merging use.At first the redox initiator reacts the generation free radical earlier, when radical transfer is the carrying out of initiated polymerization to monomer, can discharge a large amount of heats when carrying out owing to polyreaction elevates the temperature, when temperature reaches the decomposition temperature of thermolysis type initiator, can cause the decomposition of second section thermolysis type initiator again, and whole polyreaction is more attained in fully.The general suitable consumption of Raolical polymerizable initiator be weight percentage 0.001wt% to 10wt% (with in and acrylate weight be benchmark), more suitable consumption then is between the 0.1wt% to 5wt%, when operating weight per-cent 0.001wt% is following, react too slow unfavorable economic benefit, when operating weight per-cent 10wt% is above, react too fast, reaction heat is wayward.
Embodiment
Polyreaction of the present invention can be in the conventional batch reaction vessel, or carries out on the conveyer belt type reactor, and the super absorbent resin of reaction gained utilizes pulverizer to be cut into the following little gelinite of diameter 20mm earlier, and is better below the diameter 10mm, dries again.
Bake out temperature is dried for 100 ℃ to 180 ℃ with temperature and is advisable, bake out temperature temperature drying time below 100 ℃ is too of a specified duration, do not have an economic benefit, bake out temperature is dried more than 155 ℃ and is made linking agent carry out crosslinking reaction ahead of time, make in the subsequent drying process, can't effectively remove remaining monomer because of degree of crosslinking is too high, reach and reduce remaining monomeric effect.
Utilize shredder to pulverize, screen fixedly particle diameter after the drying, the screening fixedly particle diameter to be advisable between 0.06mm to 1.00mm, with preferable between 0.10mm to 0.85mm, the following fine powder of particle diameter 0.06mm improves the finished product dust, and the above particle of particle diameter 1.00mm makes the finished product rate of water absorption slack-off.
Produce the super absorbent resin of polyacrylic, it generally is the process of utilizing screening, size is not conformed in the super absorbent resin particle of target in to screen out, to keep the requirement of super absorbent resin final product quality, screening plant commonly used in this area comprises: the circular impact screen extension set, the straight-down negative vibrating screen classifier, multi-layer type vibrating screen classifier, oar formula vibrating screen classifier.Though the effect of the screening of these sieve apparatus is good, but, these screening installations can produce a large amount of noises because of vibration at high speed in the running, the influence that environment and operator are produced certain degree, and utilize the larger area screen cloth phase to reach the screening capacity of high benefit, often screen cloth to be changed again and more manpower and time must be expended, particularly the area of its screen cloth is bigger, must use big and many spaces to come place apparatus, how to reduce the noise content that vibration at high speed produces, and the reduction space, change number of times and personnel's usage quantity, just another important problem of technology for this reason.
Though existing many methods of improving the physical properties of super absorbent resin or enhancing productivity are invented in this area, but still do not improve the invention report of high screening efficiency, no matter be the improvement of polyreaction mode, the change of shredder grinding condition or the invention that drying efficiency increases, if there is not high efficiency screening installation creation, all can reduce the performance of practical application greatly.
The noise content that is produced during for reduction super absorbent resin screening process, and the usage quantity that reduces space screening replacing number of times and personnel, and maintenance stably manufactured, the invention provides and utilize a kind of high-level efficiency step sizing Apparatus and method for to screen, this kind high-level efficiency step sizing Apparatus and method for is characterized in that its screening plant utilizes rotational circle cartridge type mesh screen to select super absorbent resin.
Use non-vibration rotational circle cartridge type screen cloth, separating resin more than the target grain size by high speed rotating returns shredder and grinds, the screened super absorbent resin that goes out to be expected of following particle diameter, promptly not having sieve apparatus turns round because of vibration and produces the disappearance problem of a large amount of noises, and, can significantly reduce the spatial usage quantity because of its screen designs becomes cylindric, moreover, its screen area is identical with the square position person constant, needn't change screen cloth again often and for needed manpower of draping and time.
The non-vibration rotational circle cartridge type screen cloth that the present invention uses, rotational velocity range is good in 10-400rpm, in fact rotational velocity range is that 10-150rpm can obtain best screening effect, if not the speed of rotation of vibration rotational circle cartridge type screen cloth all is difficult to obtain screening effect of the present invention less than 10rpm or greater than 400rpm.
The size distribution particle shape of super absorbent resin of the present invention is to use JIS standard screen cloth, according to 220.2 (05) numbers described methods of EDANA method of inspection WSP; The screen cloth that the bottom is had the square position places electromagnetic shaker, screen cloth put in order into the little person of mesh down, the starting shock device, its amplitude of vibration is 1.0mm, stop electromagnetic shaker after for some time, screen and sort out the super absorbent resin of different-grain diameter, and utilize following equation to calculate the distribution ratio of each particle diameter.
Select performance for ease of assessment rotational circle cartridge type mesh screen of the present invention, utilize in the super absorbent resin, round tube type screen cloth screening particle diameter is judged less than the shared ratio of target screen cloth.The limit of error of the ratio that is screened less than the shared ratio of target screen cloth and blank test group when the screening particle diameter represents that the good property of round tube type screen cloth screenability is not good less than 1% the time.Limit of error circle of the ratio that is screened less than the shared ratio blank test of target screen cloth group when the screening particle diameter is during in 1-3%, and expression round tube type screen cloth screenability is good.And the limit of error of the ratio that is screened less than the shared ratio of target screen cloth and blank test group when the screening particle diameter represents that round tube type screen cloth screenability is not good greater than 3% the time, and limit of error then utilizes following equation to calculate.
Below describe the present invention in detail with embodiment; But patent of the present invention and technical scope are not limited by these embodiment then.
Reference example
Weigh 10 kilograms of super absorbent resins (name of an article: platform speed is protected BC283FHW), utilize vibratory screening apparatus (Retsch company product), mesh is respectively 20,30,35,50,100 and 140 meshes, the electromagnetic shaker concussion time is 5 minutes, the particle diameter of screening super absorbent resin, and make size distribution and be: greater than 20 meshes is that 0.13%, 20 to 35 mesh is that 0.71%, 30 to 35 mesh is 9.82%, 35 to 50 meshes are 61.87%, 50 to 100 meshes are that 26.27%, 100 to 140 mesh is 0.94%, are 0.25% less than 140 meshes.
Embodiment 1:
Weigh with 20 kilograms of the super absorbent resins of reference example, utilize rotational circle cartridge type screen cloth to screen, the screen cloth mesh is 50 meshes, speed of rotation is 40rpm, screening time is 1 minute, collection meets the super absorbent resin of target screen cloth screening criteria, and the error of calculating the ratio that is screened with the blank test group is 1.03%, and rotational circle cartridge type mesh screen selects performance good.
Embodiment 2:
Repeat embodiment 1, add rotating rod in rotational circle cartridge type screen cloth, all the other collect the super absorbent resin that meets target screen cloth screening criteria with embodiment 1, the error of calculating the ratio that is screened with the blank test group is 0.54%, and rotational circle cartridge type mesh screen is selected excellent property.
Embodiment 3:
Repeat embodiment 1, screening time is extended for 10 minutes, all the other collect the super absorbent resin that meets target screen cloth screening criteria with embodiment 1, and the error of calculating the ratio that is screened with the blank test group is 0.91%, and rotational circle cartridge type mesh screen is selected excellent property.
Embodiment 4:
Repeat embodiment one, but the super absorbent resin addition is increased to 50 kilograms, and all the other collect the super absorbent resin that meets target screen cloth screening criteria with embodiment 1, the error of calculating the ratio that is screened with the blank test group is 1.09%, and rotational circle cartridge type mesh screen selects performance good.
Comparative example 1:
Repeat embodiment 1, but utilize vibratory screening apparatus screening super absorbent resin, screen cloth mesh 50 meshes, all the other are with embodiment 1, collection meets the super absorbent resin of target screen cloth screening criteria, and the error of calculating the ratio that is screened with the blank test group is 20.97%, and the screen cloth screenability is not good.
Comparative example 2:
Repeat comparative example 1, but the electromagnetic shaker time of shaking was extended to 15 minutes by 1 minute, collect the super absorbent resin that meets target screen cloth screening criteria, the error of calculating the ratio that is screened with the blank test group is 18.06%, and the screen cloth screenability is not good.
Claims (2)
1. to be neutralization ratio carry out polyreaction and obtain at 45 to 85 moles the monomeric water-soluble unsaturated monomer of acidic group that contains in the aqueous solution of 20 to 55 weight % for the step sizing method of a super absorbent resin, described super absorbent resin; Its step sizing method comprises the steps:
(a) water gel of reaction back gained cuts into below the diameter 20mm, with 100 ℃ of warm air dryings to 180 ℃ of scopes of temperature, pulverizing, screening in advance;
(b) utilize rotational circle cartridge type mesh screen to select super absorbent resin; The speed of rotation of described rotational circle cartridge type mesh screen is 10-400rpm.
2. method according to claim 1 is characterized in that, described super absorbent resin is that neutralization ratio contains the acidic group monomer or carries out Raolical polymerizable and obtain at the described aqueous solution that adds water-soluble polymer that contains in the acidic group monomer more than 50% mole; The described acidic group monomer that contains is selected from vinylformic acid or methacrylic acid or 2-allylamine-2-methyl propane sulfonic acid or its mixture; Described water-soluble polymer is selected from polyvinyl alcohol, polyoxyethylene glycol, polyacrylic acid, polyacrylamide, starch, methylcellulose gum, vinylformic acid methylcellulose gum and ethyl cellulose, and described aqueous solution polymer addition is 0～5 weight %.
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| CN103122046A (en) * | 2011-11-18 | 2013-05-29 | 上海华谊丙烯酸有限公司 | Production method of acrylic polymer resin and products produced thereby |
| CN110870964A (en) * | 2019-12-09 | 2020-03-10 | 江苏三安消防设备有限公司 | Novel high-molecular water-based fire extinguishing gel and application thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1338486A (en) * | 2000-08-03 | 2002-03-06 | 株式会社日本触媒 | Water absorbent resin, hydrous polymer, preparations and uses thereof |
| CN1572818A (en) * | 2003-05-27 | 2005-02-02 | 株式会社日本触媒 | Method for sizing of water-absorbent resin |
| JP2005307195A (en) * | 2004-03-24 | 2005-11-04 | Nippon Shokubai Co Ltd | Method for continuously producing water-absorptive resin |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1338486A (en) * | 2000-08-03 | 2002-03-06 | 株式会社日本触媒 | Water absorbent resin, hydrous polymer, preparations and uses thereof |
| CN1572818A (en) * | 2003-05-27 | 2005-02-02 | 株式会社日本触媒 | Method for sizing of water-absorbent resin |
| JP2005307195A (en) * | 2004-03-24 | 2005-11-04 | Nippon Shokubai Co Ltd | Method for continuously producing water-absorptive resin |
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