CN1908020B - Process for producing water-absorbent resin, and uses thereof - Google Patents

Process for producing water-absorbent resin, and uses thereof Download PDF

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CN1908020B
CN1908020B CN2006101003888A CN200610100388A CN1908020B CN 1908020 B CN1908020 B CN 1908020B CN 2006101003888 A CN2006101003888 A CN 2006101003888A CN 200610100388 A CN200610100388 A CN 200610100388A CN 1908020 B CN1908020 B CN 1908020B
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polymerization
absorbent resin
weight
aqueous polymers
preparation
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CN1908020A (en
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大六赖道
入江好夫
藤野真一
藤田康弘
安积隆
石崎邦彦
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Nippon Shokubai Co Ltd
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Nippon Shokubai Co Ltd
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Abstract

The present invention provides a production process by which a water-absorbent resin of excellent quality can be obtained at a low cost by reasonable steps in aqueous solution polymerization. The process for producing a water-absorbent resin comprises the step of polymerizing an aqueous solution of water-absorbent resin-forming monomers including acrylic acid and/or its sodium salt as major components, characterized in that: (1) the polymerization starting temperature is above 50 DEG C; (2) the solid component concentration in the hydropolymer as formed by the polymerization is not more than 80 weight %; (3) the polymerization time is less than 3 minutes.

Description

The preparation method of absorbent resin and purposes
The application is that application number is 200510059246.7, and the applying date is title the dividing an application for the Chinese patent application of " absorbent resin, aqueous polymers, Preparation Method And The Use " in August 3 calendar year 2001.
Technical field
The monomer component that the present invention relates to polymerization is formed absorbent resin carries out aqueous solution polymerization, preparation is applicable to sanitary product such as paper nappy, sanitary napkin for example, the soil method with the absorbent resin in the various uses such as water-holding agent, with and resultant (aqueous polymers, absorbent resin) and contain the sanitary product of absorbent resin.
Background technology
In recent years, absorbent resin be widely used in paper nappy, sanitary napkin, adult with sanitary products such as incontinence articles, soil with in the various uses such as water-holding agent, and by mass production and consumption.
Special in paper nappy, sanitary napkin, the purposes of adult with sanitary products such as incontinence articles, in order to make the goods slimming, there is the usage quantity of absorbent resin to increase, the tendency that the usage quantity of paper pulp fiber reduces, people expect in the absorbent resin at the big product of absorbent rate under pressure, on the other hand, the usage quantity average 1 piece owing to sanitary product is a lot, and people expect the absorbent resin of low cost.Therefore, people expect to establish on the production line of absorbent resin energy-output ratio and reduce, and ejecta reduces and according to the rational preparation method of these requirements.
When the monomer component that polymerization is formed absorbent resin carries out aqueous solution polymerization, for because of the P/C that improves absorbent resin than reducing cost, various tests have been carried out, for example, polymerization in high monomer concentration, or begin polymerization at high temperature, make moisture evaporation obtain polymerization of exsiccant absorbent resin etc. at one stroke by heat of polymerization or heating.
The spy opens clear 58-71907 (waste river chemistry), the spy opens the acrylic acid brine solution that discloses the above high density of 55 weight % among the clear 59-18712 (waste river chemistry) and carries out polymerization, obtains the method for the drying solid of absorbent resin at one stroke.The acrylic acid brine solution that discloses the above high density of 30 weight % in United States Patent (USP) No. 4985518 (U.S.'s colloid) carries out polymerization, obtains the method for the drying solid of absorbent resin at one stroke.Open among the clear 55-58208 (wooden paddy) the spy, do not use linking agent, 106～160 ℃ polymerization temperature polymerization, moisture seldom obtained drying solid when polymerization was finished according to embodiment.Open among the flat 1-318022 (Mitsubishi's oiling) the spy and to disclose, the monomer that will contain 20～50 moles of % of neutralization ratio of 45～80 weight % carries out aqueous solution polymerization, obtains the method for the polymkeric substance of substantially dry state.But, in these methods, the many shortcomings of solvable component in the ratio of the absorption multiplying power of the absorbent resin that existence generates.
In addition, open clear 55-147512 (Sumitomo Chemical), spy the spy and open that clear 56-147809 (Sumitomo Chemical), spy open clear 63-275607 (Sanyo changes into), the spy opens among the clear 63-275608 (Sanyo changes into), monomer solution is supplied on the heating rotary bucket, obtains the dry thing of absorbent resin by record as can be known at one stroke.Open among the flat 1-165610 (ロ one system ァ Application De Ha one ス) the spy, almost similarly monomer solution is supplied on the face of heating, obtain exsiccant absorbent resin solid in fact.But, even these methods, the also many shortcomings of solvable component in the ratio of the absorption multiplying power of the absorbent resin of existence generation.
In addition, open among the flat 2-215801 (Mitsubishi's oiling), will utilize the monomer solution after monomeric neutralization heat heats up in gas phase, to carry out spray polymerization, but, think that therefore polymerization is difficult to control owing to polymerization about 3 seconds has just been finished the spy.
Above prior art all is to equal into previously disclosed prior art of 2 years (nineteen ninety), owing to there are various shortcomings, has not implemented in reality.
Afterwards, in order to improve the ratio of performance to price of absorbent resin, the technology that improves aspect of performance is disclosed.Open flat 4-175319 (Sanyo changes into) the spy, the spy opens among the flat 11-181005 (Japanese catalyst), attempts polymerization from low temperature, stably carries out polymerization in the time of heat extraction, top temperature is controlled at about below 90 ℃, has obtained high performance absorbent resin.Open among the flat 11-228604 (Japanese catalyst) the spy, attempting also is to begin polymerization from low temperature, stably carry out polymerization in the time of heat extraction, top temperature is controlled at about below 95 ℃, or the solid branch concentration ascending amount that forms of control has obtained high performance absorbent resin in the scope of 0.2～10 weight %.Open in flat 9-67404 (BASF) and the United States Patent (USP) No. 6187828 (BASF) the spy, disclose in pipe round tube type polymerizer and begun polymerization at low temperature, carry out heat insulation polymeric method, but owing to do not carry out heat extraction, exist the concentration of monomer solution not raise, the shortcoming of residence time elongated (a few hours).Because any one all is that sacrifice is productive in these methods, therefore cause high cost inevitably.
Recently, Journal of Applied Polymer Science, Vol.74,119-124 reported in (1999) " An Efficient Preparation Method for Superabsorbent Polymers " (Chen, Zhao).In this report, the polymerization process of low cost has been proposed, this method is the aqueous solution of monomer concentration 43.6% and initiator to be put into the container of stainless steel, soaks in the water-bath of 70 ℃ or 80 ℃, carries out polymerization.But this method does not also reach the level of industrial application.
In addition, open among the flat 10-45812 (ponding changes into product), attempt suppressing bumping, promote the radiation of water vapour, reduce the moisture value that generates gel, but there is the high price staple fibre that uses absorbing water useless in this method by in monomer solution, adding staple fibre the spy.
Summary of the invention
Problem of the present invention has provided the method for the good absorbent resin of low cost ground processability.Specifically, the base polymer that the absorption multiplying power is high and solvable component is few under the no loading is provided and has implemented the surface-crosslinked high absorbent resin of depressing of absorption multiplying power that adds by rational engineering.
The present inventor achieves the above object to have carried out conscientious research, the result is surprised to find with existing final conclusion and (opens flat 4-175319 (Sanyo changes into) as above-mentioned spy, Te Kaiping 11-181005 (Japanese catalyst), Te Kaiping 11-228604 (Japanese catalyst) is described, begin polymerization at low temperatures, reduce top temperature by heat extraction as far as possible, can obtain the saying of high performance absorbent resin thus) opposite, improve polymerization and begin temperature, transpiring moisture under the boiling temperature of gel, can obtain the high solid aqueous polymers that forms branch concentration in the short period of time, but employing In the view of prior art be irrational method high productivity obtain high performance absorbent resin, and therefore finished the present invention.Here " aqueous polymers " is meant that its solid branch concentration that forms is the following aqueous absorptive resins of 82 weight %.
In addition, in preparation method of the present invention, how to pulverize be particularly important to the height of 55～82 weight % that polymerization the is generated aqueous polymers that forms branch concentration admittedly.The monomer component that polymerization is formed absorbent resin carries out the aqueous polymers that aqueous solution polymerization generates, and is difficult under the dry situation in thick plate-like, bulk, former state such as lamellar, after pulverizing usually, through super-dry, pulverize, classification, various engineerings such as surface treatment are made the absorbent resin goods.For vinylformic acid (salt) class absorbent resin, when the solid formation of aqueous polymers divided concentration less than 55 weight %, the pulverizer of available mincer (ミ one ト チ ョ ッ パ one) type etc. were easily pulverized.In addition, if solid formation divides concentration to surpass 82 weight % then the same with the exsiccant polymkeric substance, can easily pulverize with common impingement pulverizer etc.But, divide the aqueous polymers of concentration Gu form at the above less than 82 weight % of 55 weight %, because its proterties intractable, up to the present, also not success of industrial pulverizing test.
For example, in the comparative example 1,2 of United States Patent (USP) No. 4703067 (U.S.'s colloids), obtain the aqueous polymers of solid formation branch concentration 58%, 67% respectively, but wherein putting down in writing " can not former state pulverizing; must be dry before pulverizing ", avoid in above-mentioned solid formation branch concentration range, pulverizing.
Among the Te Kaiping 4-175319 (Sanyo changes into), enumerated the pulverizer of gel, but the highest monomer concentration polymerization, be not given in the pulverizing example of the aqueous polymers of the above solid formation branch concentration of 55 weight % with 50 weight %.
Te Kaiping 10-119042 (Japanese catalyst), spy open flat 11-188725 (Japanese catalyst), spy and open to use among the flat 11-188726 (Japanese catalyst) and cut off gel by fixed blade and revolution sword and pulverize, and also do not provide the pulverizing example of the aqueous polymers of the above solid formation branch concentration of 55 weight %.
Te Kaiping 11-188727) Japanese catalyst, first field? three residences? vow wild) in, disclose by clamping and cut off with the revolution sword of the different conjugate spirals oar shape of the transfer rate that is oppositely arranged, aqueous polymers is pulverized.In embodiment 1, pulverize the aqueous polymers of water ratio 39 weight %, but do not provided the example of pulverizing the following aqueous polymers of weighted average particle footpath 100mm.In fact, the weighted average particle of the aqueous polymers of pulverizing footpath has all surpassed 100mm.
Therefore, inventor of the present invention has carried out conscientious research to the aqueous polymers that the height of 55～82 weight % that how pulverize polymerization and generate forms branch concentration admittedly, found that by using the sectionalization easily of specific pulverizer.
That is, the preparation method of absorbent resin of the present invention is, is the method that the monomer component of main component prepares absorbent resin by polymerization in the aqueous solution with vinylformic acid and/or its sodium salt, it is characterized in that,
(1) concentration of monomer component is more than the 45 weight % in the aqueous solution,
(2) making the ratio (concentration ratio) of the solid formation branch concentration in solid formation branch concentration that moisture evaporation reaches the aqueous polymers that polymerization generates and the monomer solution is more than 1.10, carries out polymerization simultaneously,
(3) the solid formation branch concentration of the aqueous polymers of polymerization generation is below the 80 weight %.
The preparation method of the absorbent resin that the present invention is other is, is the method that the monomer component of main component prepares absorbent resin by polymerization in the aqueous solution with vinylformic acid and/or its sodium salt, it is characterized in that,
(1) top temperature in the polymerization is more than 100 ℃,
(2) polymerization initiation temperature is more than 50 ℃,
(3) vinylformic acid and/or the water that evaporate in the polymerization are collected the recirculation use.
The preparation method of the absorbent resin that the present invention is other is, is the method that the monomer component of main component prepares absorbent resin by polymerization in the aqueous solution with vinylformic acid and/or its sodium salt, it is characterized in that,
(1) polymerization initiation temperature is more than 50 ℃,
(2) the solid formation branch concentration of the aqueous polymers of polymerization generation is below the 80 weight %,
(3) polymerization time was less than 3 minutes.
The preparation method of the absorbent resin that the present invention is other is, is the method that monomer component that main component forms prepares absorbent resin by polymerization in the aqueous solution with vinylformic acid and/or its salt, it is characterized in that,
(1) be used in combination photolysis type initiator and thermolysis type initiator as polymerization starter,
(2) top temperature in the polymerization is more than 105 ℃.
The preparation method of the absorbent resin that the present invention is other is, is the method that monomer component that main component forms prepares absorbent resin by polymerization in the aqueous solution with vinylformic acid and/or its salt, it is characterized in that,
(1) be used in combination photolysis type initiator and thermolysis type initiator as polymerization starter,
(2) polymerization initiation temperature is more than 50 ℃,
(3) concentration of monomer component is more than the 45 weight % in the aqueous solution.
The preparation method of the absorbent resin that the present invention is other is, is the method that monomer component that main component forms prepares absorbent resin by polymerization in the aqueous solution with vinylformic acid and/or its sodium salt, it is characterized in that,
(1) acrylic acid neutralization ratio is 50 moles more than the %,
(2) polymerization initiation temperature is more than 50 ℃,
(3) the solid formation branch concentration of the aqueous polymers of polymerization generation is below the 80 weight %,
(4) the polymerization time less than is 3 minutes.
The preparation method of the absorbent resin that the present invention is other is, is the method that monomer component that main component forms prepares absorbent resin by polymerization in the aqueous solution with vinylformic acid and/or its salt, it is characterized in that,
(1) polymerization initiation temperature is more than 50 ℃,
(2) concentration of monomer component is more than the 45 weight % in the aqueous solution,
(3) polymerization heats up than being below 0.30.
The preparation method of the absorbent resin that the present invention is other is, is the method that monomer component that main component forms prepares absorbent resin by polymerization in the aqueous solution with vinylformic acid and/or its sodium salt, it is characterized in that,
(1) polymerization initiation temperature is more than 50 ℃,
(2) concentration of monomer component is more than the 45 weight % in the aqueous solution,
(3) top temperature in the polymerization is below 140 ℃.
The preparation method of the absorbent resin that the present invention is other is, is the method that the monomer component of main component prepares absorbent resin by polymerization in the aqueous solution with vinylformic acid and/or its sodium salt, it is characterized in that,
(1) concentration of monomer component is more than the 45 weight % in the aqueous solution,
(2) acrylic acid neutralization ratio is 50 moles more than the %,
(3) polymerization initiation temperature is more than 50 ℃,
(4) the difference Δ T of the top temperature that reaches in polymerization initiation temperature and the polymerization is below 70 ℃.
The preparation method of the absorbent resin that the present invention is other is, is the method that monomer component that main component forms prepares absorbent resin by polymerization in the aqueous solution with vinylformic acid and/or its salt, it is characterized in that, carries out polymerization in the time of extension.
The preparation method of the absorbent resin that the present invention is other is, is the method that the monomer component of main component prepares absorbent resin by polymerization in the aqueous solution with vinylformic acid and/or its salt, it is characterized in that the aqueous polymers that the solid formation branch concentration that polymerization is generated is 55～82 weight % further is crushed to the weighted average particle directly for below the 100mm.
The preparation method of the absorbent resin that the present invention is other is, is the method that the monomer component of main component prepares absorbent resin by polymerization in the aqueous solution with vinylformic acid and/or its salt, it is characterized in that the aqueous polymers that the solid formation branch concentration that polymerization is generated is 55～82 weight % further uses the pulverizer that has filtering net to pulverize.
The preparation method of the absorbent resin that the present invention is other is, is the method that the monomer component of main component prepares absorbent resin by polymerization in the aqueous solution with vinylformic acid and/or its salt, it is characterized in that, the aqueous polymers that the solid formation branch concentration that polymerization is generated is 55～82 weight % further uses pulverizer to pulverize, and makes to form the rising of branch concentration in the pulverizing admittedly more than 2.
The preparation method of the absorbent resin that the present invention is other is, is the method that the monomer component of main component prepares absorbent resin by polymerization in the aqueous solution with vinylformic acid and/or its salt, it is characterized in that the aqueous polymers that the solid formation branch concentration that polymerization is generated is 55～82 weight % further uses pulverizer to pulverize in ventilation.
The preparation method of the absorbent resin that the present invention is other is, is the method that the monomer component of main component prepares absorbent resin by polymerization in the aqueous solution with vinylformic acid and/or its salt, it is characterized in that formation branch concentration that the aqueous polymers pulverizing that polymerization is generated obtains, solid is 55～82 weight %, the particle shape aqueous polymers below the remaining amount of monomer 1000ppm, below the 3mm of weighted average particle footpath carries out surface-crosslinked.
The preparation method of the absorbent resin that the present invention is other is, is the method that the monomer component of main component prepares absorbent resin by polymerization in the aqueous solution with vinylformic acid and/or its salt, it is characterized in that comprising,
(1) the solid formation of preparation branch concentration is the polymerization engineering of the aqueous polymers of 55～82 weight %,
(2) will form branch concentration admittedly is that the aqueous polymers of 55～82 weight % is crushed to the following comminution engineering of weighted average particle footpath 10mm,
(3) the solid formation branch concentration of the aqueous polymers after will pulverizing improves the drying process more than 3%.
The other absorbent resin of the present invention is, is the absorbent resin that the monomer component of main component obtains by polymerization in the aqueous solution with vinylformic acid and/or its sodium salt, it is characterized in that having following physical properties,
(1) 20 (g/g)≤no loading absorbs multiplying power (GV)≤60 (g/g) down,
(2) absorbent rate under pressure (AAP) 〉=20 (g/g)
(3) no loading absorbs down multiplying power (GV) * can dissolve survival rate (%)≤1200 ((g/g) %).
Aqueous polymers of the present invention is, is that the monomer component of main component obtains when preparing absorbent resin by polymerization in the aqueous solution with vinylformic acid and/or its salt, it is characterized in that, Gu to form branchs concentration be 55～82 weight %, below the remaining amount of monomer 1000ppm, the aqueous polymers of the pulverizing below the 3mm of weighted average particle footpath.
Sanitary product of the present invention contains at least a absorbent resin that obtains by the invention described above preparation method and the absorbent resin of the invention described above of being selected from.
[Fig. 1]
Among embodiment 3 and the embodiment 7～10, expression polymeric reaction temperature and time relation figure.Time 0 is that rayed is when beginning.
[Fig. 2]
The side photo of the aqueous polymers that embodiment 1 obtains.
[Fig. 3]
The side photo of the aqueous polymers that embodiment 3 obtains.
[Fig. 4]
The top photo of the aqueous polymers that embodiment 3 obtains.
[Fig. 5]
The following photo of the aqueous polymers that embodiment 3 obtains.
[Fig. 6]
The side photo of the aqueous polymers that embodiment 5 obtains.
[Fig. 7]
The side photo of the aqueous polymers that embodiment 7 obtains.
[Fig. 8]
Cut the part of the aqueous polymers that embodiment 7 obtains, with the expand photo of back gel of tap water.
Embodiment
Below embodiments of the present invention are described in detail.
The example that forms the monomer component of absorbent resin as the polymerization of using among the present invention can be enumerated (methyl) vinylformic acid, (anhydrous) toxilic acid, methylene-succinic acid, styracin, vinyl sulfonic acid, allyl group toluenesulphonic acids, vinyl toluene sulfonic acid, styrene sulfonic acid, 2-(methyl) acrylamide-2-methyl propane sulfonic acid, 2-(methyl) acryl ethane sulfonic acid, 2-(methyl) acryl propane sulfonic acid, the negatively charged ion unsaturated monomer and the salt thereof of 2-hydroxyethyl (methyl) acryl phosphoric acid ester etc.; The unsaturated monomer that contains thiol group; The unsaturated monomer that contains the phenol hydroxyl; (methyl) acrylamide, N-ethyl (methyl) acrylamide, N, N-dimethyl (methyl) acrylamide etc. contains the unsaturated monomer of amide group; N, N-dimethyl aminoethyl (methyl) acrylate, N, N-dimethylaminopropyl (methyl) acrylate, N, N-dimethylaminopropyl (methyl) acrylamide etc. contain amino unsaturated monomer etc.These monomers can use separately or suitably two or more mixing is used, but consider from the performance and the cost of gained absorbent resin, it is necessary using for main component with vinylformic acid and/or its salt (for example, in the salt of sodium, lithium, potassium, ammonium, amine etc., considering particular certain cancers from cost).Preferred vinylformic acid and/or its salt are 70 moles more than the % with respect to the monomer component total amount, preferred 80 moles more than the %, and more preferably 90 moles more than the %, preferred especially 95 moles more than the %.
Here the solid formation in the said monomer solution divides except unsaturated monomer compositions such as vinylformic acid and/or its salt, internal crosslinking agent, also comprises other additives such as polymerization starter described later.
As above-mentioned internal crosslinking agent, can use the known internal crosslinking agent of prior art.Specifically can enumerate, the spy opens the p.4 middle internal crosslinking agent of putting down in writing among the flat 10-182750.Wherein, consider, can use more than a kind or 2 kinds from reactivity.Wherein, the compound that preferably has 2 above polymerizability unsaturated groups must use.This usage quantity can be according to the physical properties of desired absorbent resin, suitably decision.
The concentration that forms the monomer component of absorbent resin for polymerization has no particular limits, more than the preferred 30 weight %, more preferably more than the 35 weight %, more preferably more than the 40 weight %, more preferably more than the 45 weight %, more preferably more than the 50 weight %, more preferably more than the 55 weight %, more preferably 30～70 weight %, more preferably 35～60 weight %, more preferably 40～60 weight %.During less than 30 weight %, productivity is low, when surpassing 70 weight %, absorbs the multiplying power step-down.
Have no particular limits for the monomeric neutralization ratio that contains acid group, but at sanitary product etc., exist in the purposes of the possibility that contacts with human body, need not neutralize after the polymerization, preferred 50 moles more than the %.More preferably 80 moles of % of 50 moles of above less thaies of %, more preferably 55 moles of % above 78 moles below the %, and most preferably 60 moles of % above 75 moles below the %.
When with in the alkali and during vinylformic acid, preferably in the intensification of monomer solution, effectively utilize neutralization heat and/or (the propylene bronsted lowry acids and bases bronsted lowry) solution heat.In preferred embodiments, adding linking agent and initiator begin polymerization in the monomer solution that heats up by neutralization in state of thermal isolation.Perhaps, as described later, neutralization heat and/or (the propylene bronsted lowry acids and bases bronsted lowry) solution heat are used to remove dissolved oxygen.
When polymerization, also can in reaction system, add hydrophilic macromolecule or ortho phosphorous acid chain-transfer agent, sequestrants such as (salt) such as starch, starch derivative, Mierocrystalline cellulose, derivatived cellulose, polyvinyl alcohol, polyacrylic acid (salt), the crosslinked body of polyacrylic acid (salt).
As the polymerization process of above-mentioned monomer component, if aqueous solution polymerization has no particular limits this, can be by monomer solution be left standstill polymerization at the static condition polymeric, polymeric stirs enforcement the present invention such as polymerization in whipping appts.
In leaving standstill polymerization, preferably use annular belt.Belt preferred polymeric heat is from the resin that connects the material surface and be difficult for emitting or the belt of rubber system.
In stirring polymerization, can use the single shaft stirrer, but the preferred stirrer that a plurality of stir shafts are arranged that uses.
In general free yl solution polymerization, before polymerization starter drops into, be blown into rare gas element, the decompression degassing is removed and is hindered the polymeric dissolved oxygen, needs equipment and running funds for this reason, and this is present truth.In a preferred embodiment of the invention, the operation of removing dissolved oxygen heats up monomer solution as previously mentioned by utilizing neutralization heat and/or (propylene bronsted lowry acids and bases bronsted lowry) solution heat, and volatilization dissolved oxygen carries out.
In a more preferred embodiment, to not carry out deoxidation in advance as the vinylformic acid of monomer solution raw material, alkali aqueous solution, water etc., and heat up by neutralization, the amount of dissolved oxygen is with respect to below the preferred 4ppm of monomer solution, more preferably below the 2ppm, most preferably below the 1ppm, former state can not carried out the deoxidation operation and directly supply with polymerization.
In addition, preferably will heat up further deoxidation as part or all partly deoxidation in advance of the vinylformic acid of monomer solution raw material, alkali aqueous solution, water etc. by neutralizing.In addition, with vinylformic acid and the neutralization of alkali on-line mixing, further the on-line mixing polymerization starter begins in order to prevent in-line polymerization when the high temperature more than 80 ℃ begins polymerization, and preferred feedstock vinylformic acid, alkali aqueous solution, water etc. do not carry out deoxidation in advance.
Polymerization is carried out under normal pressure usually, but in order to reduce the boiling temperature of polymerization system, preferably under reduced pressure heats up in a steamer when anhydrating and carry out.For processing ease etc., more preferably under normal pressure, be to carry out under the normal atmosphere.
Rising has no particular limits for the neutralization ratio in the polymerization, and is preferred more than 2, more preferably more than 3, more preferably more than 4.Neutralization ratio rises to did not have special problem at 0 o'clock yet, if but rise more than 2, the rerum natura of resulting polymers (aqueous polymers, base polymer, absorbent resin) can improve, and is preferred from this point.
Polymerization starter as using among the present invention has no particular limits, and can use thermolysis type initiator (for example, persulphate: Sodium Persulfate, Potassium Persulphate, ammonium persulphate; Superoxide: hydrogen peroxide, tert-butyl peroxide, methyl-ethyl-ketone peroxide); Azo-compound: azonitrile compound, azo amidine compound, ring-type azo amidine compound, the azo amide compound, alkyl azo-compound, 2, two (2-amidine propane) dihydrochlorides of 2 '-azo, 2, two [2-(2-tetrahydroglyoxaline-2-yl) propane] dihydrochlorides of 2 '-azo) or photolysis type initiator (for example, benzoin derivative, the benzil derivative, acetophenone derivs, benzophenone derivates, azo-compound) etc.Consider preferred persulphate from cost, the remaining monomer capable of reduction aspect.In addition, preferred light decomposition type initiator and the ultraviolet method of share.More preferably photolysis type initiator and thermolysis type initiator are used in combination.
Monomeric temperature preferably raises in advance.Its reason is, does to make the foregoing dissolved oxygen of removing become easily like this, and, as described below, can directly reach preferred polymerization initiation temperature.Have no particular limits for such monomer temperature, be generally more than 50 ℃, preferred more than 60 ℃, more preferably more than 70 ℃, more preferably more than 80 ℃, more preferably more than 90 ℃, more preferably 80 ℃～105 ℃, most preferably 90～100 ℃.If 50 ℃ of less thaies are between inductive phase, the prolongation of polymerization time not only can reduce productivity, and can reduce the physical properties of absorbent resin.In addition, polymerization time is meant, monomer solution is put into aggregation container, begins time till the top temperature from possessing the polymerization condition of beginning.
Polymerization initiation temperature is generally more than 50 ℃, and is preferred more than 60 ℃, more preferably more than 70 ℃, and more preferably more than 80 ℃, more preferably more than 90 ℃, more preferably 80 ℃～105 ℃, most preferably 90～100 ℃.If 50 ℃ of polymerization initiation temperature less thaies are between inductive phase, the prolongation of polymerization time not only can reduce productivity, and can reduce the physical properties of absorbent resin.When if polymerization initiation temperature surpasses 105 ℃, foaming or extension just can not be abundant.Polymerization initiation temperature can be by monomer solution observation such as gonorrhoea, viscosity rising, temperature rising.
In addition, for temperature and the initiated polymerization of guaranteeing this monomer solution begins, preferably utilize neutralization heat and/or (the propylene bronsted lowry acids and bases bronsted lowry) solution heat of foregoing monomer solution.
Have no particular limits for the Da Wendu that is up in the polymerization, preferred below 150 ℃, more preferably below 140 ℃, more preferably below 130 ℃, more preferably below 120 ℃, more preferably below 115 ℃.If surpass 150 ℃, the physical properties of resulting polymers (aqueous polymers, base polymer, absorbent resin) significantly reduces, and is not preferred therefore.
In the present invention, the difference Δ T that is up to Da Wendu in polymerization initiation temperature and the polymerization is preferred below 70 ℃, more preferably below 60 ℃, more preferably below 50 ℃, more preferably below 40 ℃, more preferably below 30 ℃, most preferably below 25 ℃.If Δ T is bigger than 70 ℃, the physical properties of resulting polymers (aqueous polymers, base polymer, absorbent resin) significantly reduces, and is not preferred therefore.
Have no particular limits for polymerization time, preferred below 5 minutes, more preferably below 3 minutes, more preferably less than is 3 minutes, more preferably below 2 minutes, more preferably below 1 minute.If surpass 5 minutes, the productivity of resulting polymers (aqueous polymers, base polymer, absorbent resin) reduces, and is not preferred therefore.
The preferred example of polymerization process according to the present invention, after polymerization began, system temperature rose rapidly, and the oligomerization rate for example reaches boiling point at 10～20 moles of %, and the water vapour evaporation is carried out polymerization Gu form when branch concentration rises.Effectively utilize heat of polymerization and improve the solid branch concentration that forms.Therefore, preferably powerful the inhibition emitted heat from the material portion that connects of aggregation container, as material, can preferably use resin, rubber, the stainless non-material that material portion hides with lagging material that connects, or the material by the sleeve pipe heating etc.The water vapour that evaporates from system, owing to contain monomer, preferably in situ recovery uses.Particularly, preferably collect the vinylformic acid and/or the water that evaporate in the polymerization, recirculation is used.Acrylic acid rate of recovery, preferred more than 1% with respect to the gross weight of employed vinylformic acid (before the neutralization), more preferably more than 2%, more preferably more than 3%.
In addition, the inventive method is characterised in that when polymerization begins and can be speculated as and reaches reasons of high performance just in high temperature polymerization.Polymerization under normal pressure has reached the temperature more than 100 ℃ during 40 moles of % of percent polymerization, also in the temperature more than 100 ℃, such polymerization is preferred mode during 50 moles of % of percent polymerization.Reached the temperature more than 100 ℃ during 30 moles of % of percent polymerization, also in the temperature more than 100 ℃, such polymerization is preferred mode during 50 moles of % of percent polymerization.Reached the temperature more than 100 ℃ during 20 moles of % of percent polymerization, also in the temperature more than 100 ℃, such polymerization is most preferred mode during 50 moles of % of percent polymerization.Under reduced pressure in the polymerization, reached boiling temperature when also being 40 moles of % of percent polymerization, also at boiling temperature, such polymerization is preferred mode during 50 moles of % of percent polymerization.Reached boiling temperature during 30 moles of % of percent polymerization, also at boiling temperature, such polymerization is preferred mode during 50 moles of % of percent polymerization.Having reached boiling temperature during 20 moles of % of percent polymerization, has been most preferred mode in such polymerization of boiling temperature also during 50 moles of % of percent polymerization.
Like this, owing to just arrived high temperature under the oligomerization rate, the time weak point that polymerization is used is finished below 10 minutes usually, and is preferred below 5 minutes.Here the used time of polymerization is meant that putting into aggregation container from the monomer solution that adds polymerization starter begins, the time till extremely aqueous polymers being taken out from aggregation container.
According to the present invention, carry out polymerization when should be transpiring moisture, be preferably more than 1.10 with the solid formation branch concentration that reaches the aqueous polymers that generates by polymerization ratio (concentration ratio) with the solid formation branch concentration of monomer solution, more preferably more than 1.15, more preferably more than 1.20, more preferably more than 1.25.During concentration ratio less than 1.10, utilizing of heat of polymerization is insufficient.Here, the solid formation branch of monomer solution is meant monomer and other additives, not moisture or solvent.
According to the present invention, polymerization heat up than promptly polymerization be observed Δ T (top temperature that arrives in the polymerization and polymerization initiation temperature poor, ℃) and theoretical Δ T (℃) ratio (detailed method of calculation as shown in the Examples) preferred below 0.30.More preferably below 0.25, more preferably below 0.20.Polymerization heats up bigger than 0.30 such as fruit, and the application that heat of polymerization is used for moisture evaporation is insufficient, and the rerum natura of resulting polymers (aqueous polymers, base polymer and absorbent resin) can reduce, and is not preferred from this aspect.
The above-mentioned aqueous polymers that obtains by polymerization, its solid formation is divided below the preferred 82 weight % of concentration, more preferably below the 80 weight %, more preferably below the 75 weight %.In addition, preferred 50 weight %～82 weight %, more preferably 55 weight %～82 weight %, more preferably 60 weight %～78 weight %, more preferably 60 weight %～75 weight %, more preferably 60 weight %～73 weight %, more preferably 66 weight %～73 weight %.Divide concentration to surpass 82 weight % if be somebody's turn to do solid formation, can see that performance is low, promptly absorbing multiplying power reduction and solvable component increases.In addition, this solid formation when dividing concentration less than 50 weight %, the drying burden of follow-up engineering is very big, is not preferred from this aspect.
Above-mentioned aqueous polymers, the form that foaming and intumescing and contraction form when preferably having by polymerization.This form is because the water vapour pressure that polymerization time boiling produces can make polymerization system carry out the foaming of cm～mm unit's diameter, and surface-area increases, and promotes water vapour volatilization, the form of Shou Suoing (shown in the photo of Fig. 3～7) afterwards thus.In addition, the separability that this form also has polymerizer improves, or the pulverizing of the aqueous polymers beyond thought so easily feature that becomes.
The measuring method of expansion multiplying power is as described in the embodiment in the polymerization.Expansion multiplying power in the polymerization is preferred more than 2 times, more preferably more than 3 times, more preferably more than 5 times, more preferably more than 10 times, more preferably more than 20 times.Owing to when expanding polymerization system is extended, therefore when extending, carries out polymerization.
After above-mentioned aqueous polymers sectionalization, carry out drying, pulverizing, can obtain base polymer (carrying out the preceding absorbent resin of surface treatment).
If with the base polymer of microscopic examination gained, even the polymerization when being attended by foaming, because the size of its bubble is bigger, interior most particle becomes the noncrystal shape that does not contain bubble.
In preparation method of the present invention, base polymer further can be carried out surface-crosslinked processing, can obtain the big absorbent resin of absorbent rate under pressure by this processing.Surface-crosslinked processing can be used normally used known surface crosslinking agent and known surface-crosslinked method in this purposes.
In addition, in this manual,, all be the term of a kind of form of any one absorbent resin of expression though use terms such as aqueous polymers, base polymer, surface-crosslinked absorbent resin.
Among the preparation method of the present invention, the absorbent resin that height how to pulverize 55～82 weight % that polymerization generates forms branch concentration admittedly is important.The monomer component that polymerization is formed absorbent resin carries out the aqueous polymers that aqueous solution polymerization generates, be thick plate-like, bulk, lamellar etc. when directly being difficult to the exsiccant shape, usually after pulverizing, through various engineerings such as super-dry, pulverizing, classification, surface treatments, make the absorbent resin goods.Vinylformic acid (salt) class absorbent resin, when the solid formation of aqueous polymers divided concentration less than 55 weight %, the pulverizer of available Minced Steak type etc. were easily pulverized.In addition, Gu when form dividing concentration to surpass 82 weight %, the same with the exsiccant polymkeric substance, can easily pulverize with common impingement pulverizer etc.But, divide the aqueous polymers of concentration Gu form at the above less than 82 weight % of 55 weight %, because its proterties intractable, up to the present, also not success of test is pulverized in industry.
Therefore, the present inventor has carried out conscientiously research for how pulverizing the aqueous polymers that height that polymerization generates 55～82 weight % obtain forms branch concentration admittedly, found that, by using specific pulverizer or pulverizer (these all use this speech representative of pulverizer in present patent application) sectionalization easily.
In addition, the shape that is the aqueous polymers of 55～82 weight % with solid formation branch concentration for the supply pulverizing has no particular limits, tabular or the sheet that preferred thickness 3cm is following, the more preferably following tabular or sheet of thickness 2cm, the more preferably following tabular or sheet of thickness 1cm, foaming and intumescing and shrink tabular or sheet below the thickness 5cm of the many fold form that forms during more preferably by polymerization.
As forming the device that branch concentration is the aqueous polymers pulverizing of 55～82 weight % in the present invention admittedly, preferably have the pulverizer of filtering net.Furtherly, preferably be equivalent to the shear-type primary crusher in the pulverizer classification of table 16.4 of chemical engineering brief guide (change that fixed six editions, chemical engineering can be compiled, ball kind (strain), 1999) or cut off the cut-out grinder as this pulverizer.The further preferred device of pulverizing of cutting off that adopts dead knife and rotating knife.By pulverizing with such device, the aqueous polymers that the height of 55～82 in the past difficult weight % can be formed admittedly branch concentration is easily pulverized.
It is following listed that the concrete example of grinding machine is cut off in shear-type primary crusher or cut-out.
Saw, annular saw, バ Application De ソ one (BAND SAW)
Perpendicular type pulverizer (VERTICAL CUTTING MILL (strain) ォ リ ェ Application ト society)
ロ one ト プ レ ッ Network ス (ROTOPLEX, ホ ソ カ ヮ ミ Network ロ Application (strain))
タ one ボ カ ッ タ one (TURBO CUTTER, タ one ボ industry (strain))
タ one ボ グ ラ ィ Application ダ one (TURBO GRINDER, タ one ボ industry (strain))
タ ィ ャ シ ュ レ ッ ダ one (the CUTTER MILL of ROTARY, (strain) increases the wild institute that makes)
ロ one タ リ one カ ッ タ, one ミ Le (ROTARY CUTTER MILL, (strain) Jitian makes institute)
カ ッ タ one ミ Le (CUTTER MILL, Tokyo ァ ト マ ィ ザ one makes (strain))
シ ュ レ ッ De Network ラ ッ シ ャ one (SHRED CRUSHER, Tokyo ァ ト マ ィ ザ one makes (strain))
カ ッ タ one ミ Le (CUTTER MILL increases good fortune industry (strain))
Network ラ ッ シ ャ one (CRUSHER increases good fortune industry (strain))
ロ one タ リ one カ ッ タ one ミ Le (ROTARY CUTTER MILL, (strain) nara machinery is made institute)
ガ ィ Na ッ Network ス Network ラ ッ シ ャ (GAINAX CRUSHER, (strain) ホ one ラ ィ)
ュ one コ system (U-COM, (strain) ホ one ラ ィ)
メ ッ Application ュ ミ Le (MESHMILL, (strain) ホ one ラ ィ)
In the present invention, when the solid aqueous polymers that forms branch concentration 55～82 weight % is pulverized with pulverizer, solid formation branch concentration (is for example risen more than 2, become 72 weight % then 2 points that rise if the solid aqueous polymers that forms branch concentration 70 weight % is pulverized the solid branch concentration that forms in back), or in pulverizer, ventilate preferred dry air, or two the aspect all carry out, like this, even use cutting mode pulverizer in addition, pulverize the aqueous polymers of difficulty before also can seeing like this and pulverized.
Gu form to divide the rising of concentration high than 2, rate of rise such as 3 points, 4 are high more, or the big more then pulverizing of ventilation is easy more, selects but should take into account economy.Can think when pulverizing, condensing in device from the water vapour of aqueous polymerization deposits yields, in installing, be easy to take place adhering to, stopping up of aqueous polymers, be not prone to but just become by this phenomenon of ventilating.
In addition, during pulverizing, can add the tensio-active agent that the spy opens record among the flat 11-188726 (Japanese catalyst), but the solid formation of aqueous polymers is when dividing concentration high, its necessity reduces.
Below the preferred 100mm of weight average particle diameter of the aqueous polymers of pulverizing with pulverizing means of the present invention, more preferably below the 10mm, more preferably below the 3mm, most preferably below the 1mm.Under the state of aqueous polymers, the granularity that can be crushed to end article is an ideal.
Remaining amount of monomer for the particle shape aqueous polymers of pulverizing with pulverizing means of the present invention has no particular limits, but for preventing remaining monomeric dispersing in follow-up dry engineering etc., preferably below the 3000ppm.According to purposes, below the preferred 1000ppm, more preferably below the 500ppm, most preferably below the 300ppm.When particularly particle shape aqueous polymers former state being used for sanitary product purposes such as paper nappy, below the preferred 1000ppm, more preferably below the 500ppm.
The preferably solid formation branch of aqueous polymers (the particle shape aqueous polymers) concentration of pulverizing with pulverizing means of the present invention is 55～82 weight %, below the remaining monomer 1000ppm, below the weight average particle diameter 3mm.
In addition, in solid formation branch concentration of the present invention is 55～82 weight %, in the aqueous polymers (particle shape aqueous polymers) of the pulverizing that remaining amount of monomer 1000ppm is following, weight average particle diameter 3mm is following, do not contain the material that adds water formation in the oriented material that has reached drying regime (solid formation more than branch concentration 83 weight %).
In preparation method of the present invention, can be with the aqueous polymers drying after pulverizing.Do not deposit special restriction for drying means, preferred use resemble stir desiccating method, fluidised bed desiccating method, the air stream drying method etc., make material in motion with hot blast or the good drying means that contacts of thermal conductive surface.
Among the preparation method of the present invention, the aftertreatment of the aqueous polymers after the pulverizing (particle shape aqueous polymers) can be selected from following method.
1. with particle shape aqueous polymers former state goodsization; Be directly used in sanitary product or agriculture and garden and purposes such as use.Be the flowability of increase particle, but the sub-shape inorganic substance of hybrid fine particles (wilkinite, zeolite, silicon oxide etc.).
2. particle shape aqueous polymers is mixed, reacts with surface crosslinking agent, carry out goodsization with saturation state; Need not make the energy of moisture evaporation.Be the flowability of increase particle, but the sub-shape inorganic substance of hybrid fine particles (wilkinite, zeolite, silicon oxide etc.).
3. particle shape aqueous polymers is mixed, reacts with surface crosslinking agent, drying is goodsization then; Be used for exsiccant add that heat energy is also used as can be with the energy of surface-crosslinked reaction.
4. with particle shape aqueous polymers drying, former state goodsization.
5. with particle shape aqueous polymers drying, pulverizing, classification be goodsization then.
6. with particle shape aqueous polymers drying, pulverizing, classification, carry out surface-crosslinked goodsization then.
With pulverizing the aqueous polymers pulverizing of difficult solid formation branch concentration 55～82 weight % in the past and obtaining particle shape aqueous polymers, make following new purposes become possibility.
1) above-mentioned 1. 2. 3. method become possibility.
2) as when drying forms the aqueous polymers of branch concentration less than 55 weight % admittedly, it is difficult not adding as far as possible that drying means that tensio-active agent etc. has the material of molding effect uses, can use the good stirring desiccating method of thermo-efficiency, fluidised bed desiccating method, air stream drying method etc. well contacts material with hot blast or thermal conductive surface in motion drying means.
3) owing to can polymkeric substance be pulverized, therefore can obtain being difficult for producing micro mist, few particle shape aqueous polymers of micro mist at saturation state.
As other preferred preparation methods that the present invention relates to, can enumerate by polymerization in the aqueous solution is the method that the monomer component of main component prepares absorbent resin with vinylformic acid and/or its sodium salt, it is characterized in that comprising,
(1) the solid formation of preparation branch concentration is the polymerization engineering of the aqueous polymers of 55～82 weight %,
(2) will form branch concentration admittedly is that the aqueous polymers of 55～82 weight % is crushed to the following comminution engineering of weighted average particle footpath 10mm,
(3) the solid formation branch concentration of the aqueous polymers after will pulverizing improves the dry engineering more than 3%.
Owing to possess this 3 step engineering, method with the good absorbent resin of low cost processability can be provided, reasonably step can provide with no loading to absorb the few base polymer of the high solvable component of multiplying power down and carried out the high absorbent resin of surface-crosslinked absorbent rate under pressure.
But the invention provides good operation in the purposes of sanitary product etc., do not expand when abandoning after the use, can easily be decomposed into the new absorbent resin of straight-chain polymer in addition.
In the past, the discarded method after being used by the human consumer as sanitary products such as paper nappy that contains absorbent resin or sanitary napkins had (1) burning (2) landfill (3) to subtract appearanceizations processing afterfire (4) to wash (5) composting (6) additive method of releasing from the lavatory.For the depleted absorbent resin a lot of investigation have been carried out in the influence of environment, be reported as the level that reaches out of question.But, when the sanitary product after will using is imbedded in the soil, because the moisture expansible in the absorbent resin absorbent earth is very big, consider and occupy discarded site space, up to the present also not becoming problem, but also should consider this class problem from now on, should be can to dissolve or decompose in environment therefore.
Therefore, also carried out the research of some Biodegradable absorbent resin.For example have, the spy opens flat 11-255896 (Mitsui Chemicals), spy and opens 2001-114803 (ュ ニ チ カ), spy and open flat 8-59820, spy and open flat 8-196901, spy and open flat 8-89796, spy and open flat 9-124754, spy and open flat 9-216914 (above be the application of Japanese catalyst).But these are all expensive or use complex engineering to obtain the high goods of price owing to raw material, and on performance no more than the acrylic acid or the like absorbent resin, be also not reach practicability at present therefore.
Open among the 2001-104929 (Japanese ァ サ ヒ machine worker buys to resell shell) the spy, the paper nappy that has proposed to use subtracts the method for appearanceization processing, the absorbent resin smaller volume after wishing to use.
For the sanitary product that watering privy washes away that passes through that contains absorbent resin motion (spy opens flat 6-210166, United States Patent (USP) 5415643, キ Application バ リ one Network ラ one Network) is arranged also.Because absorbent resin expands in water shoot, the blocked possibility of pipe is improved.Therefore, wash away then wish that absorbent resin can dissolve or decompose if wash the lavatory with water.
In addition, the discarded absorbent resin that in the absorbent resin preparation engineering, produces, though consider to carry out burn processing, also the someone tests it is effectively applied flexibly.For example, in United States Patent (USP) No. 6143820 (ダ ゥ), proposed, the acrylic acid or the like absorbent resin has been decomposed, made straight chain polymer, applied flexibly to prevent agent, lotion additive etc. as dispersion agent, fouling.
The invention provides the novel absorbent resin that has solved this problem.The absorbent resin that promptly the present invention relates to is to be the absorbent resin that the monomer component of main component obtains by polymerization in the aqueous solution with vinylformic acid and/or its sodium salt, it is characterized in that having following physical properties,
The absorption multiplying power (GV)≤60 (g/g) of (1) 20 (g/g)≤no loading situation,
(2) absorbent rate under pressure (AAP) 〉=20 (g/g)
(3) the absorption multiplying power (GV) of no loading situation * can dissolve survival rate (%)≤1200 ((g/g) %).
Preferred 25～55 (g/g) of the absorption multiplying power (GV) of above-mentioned no loading situation, more preferably 25～50 (g/g).If littler than 20 (g/g), economy is bad, if can not get practical gel-strength greatly than 60 (g/g), is not preferred from this aspect.
More than preferred 25 (g/g) of above-mentioned absorbent rate under pressure (AAP), more preferably more than 30 (g/g), more preferably more than 35 (g/g).If littler than 20 (g/g), when the gained absorbent resin is used for sanitary product with high density, can not bring into play good performance, from this aspect, or not preferred.
The absorption multiplying power (GV) of above-mentioned no loading situation * can dissolve below preferred 1000 ((g/g) %) of value of survival rate (%), more preferably below 800 ((g/g) %), more preferably below 600 ((g/g) %).If bigger than 1200 ((g/g) %), the absorbent resin of gained is difficult for decomposing and can dissolving, and is not preferred from this aspect.
Above-mentioned absorbent resin is to be the absorbent resin that the monomer component of main component obtains by polymerization in the aqueous solution with vinylformic acid and/or its salt, it is characterized in that,
(1) the monomer component branch concentration in the aqueous solution is more than the 50 weight %,
(2) amount of internal crosslinking agent is 0.02 mole of monomer component total amount below the %,
(3) carry out surface-crosslinked processing,
(4) add more than the sequestrant 10ppm.
That is, monomer solution concentration is to be necessary more than the 50 weight %, preferred 53～70 weight %.The amount of internal crosslinking agent is that 0.02 mole of monomer component total amount is necessary below the %, preferred 0.01 mole below the %, and more preferably 0.005 mole below the %.In addition, it also is necessary carrying out surface-crosslinked processing, and the GV of the crosslinked body of preferred surface is below 80% of base polymer GV, more preferably below 70%, more preferably below 60%, most preferably below 50%.
When using in sanitary product, absorbent resin is decomposed, because impracticable, it is necessary therefore adding sequestrant.The interpolation of sequestrant can be in any stage of absorbent resin preparation engineering.Addition be 10ppm when following effect bad, preferably add more than the 20ppm.
Embodiment
Below by embodiment and comparative example the present invention is further detailed, but the present invention is not limited to these embodiment.In addition, in following example, except as otherwise noted, " part " expression " weight part ".
[no loading absorbs the mensuration of multiplying power (GV) down]
With absorbent resin 0.2g homogeneous pack into non-woven bag (among the 60cm * 60cm), will dipping in its sodium chloride aqueous solution (physiological saline) at 0.9 weight %.After 30 minutes, bag is picked up, use centrifuge separator with 250 * 9.81m/s 2(250G) remove moisture 3 minutes, measure the weight W 1 (g) of bag afterwards.In addition, do not use absorbent resin to carry out same operation, measure weight W 0 (g) at this moment.Then, from weight W 1, W0 according to following formula
[several 1]
Calculate GV (no loading absorbs multiplying power down).
In addition, in the GV of aqueous polymers measures, use to form admittedly and divide 0.2g, dipping is 24 hours in physiological saline, except the correction of when calculating GV, carrying out solid formation branch, and other carry out the same with absorbent resin.
[mensuration of solvable component and neutralization ratio]
In the plastic containers with cover of 250ml capacity, measure the 0.9 weight %NaCl aqueous solution (physiological saline) 184.3g, in this aqueous solution, add absorbent resin 1.00g, stirred 16 hours, extract the solvable component in the resin.Measure filtrate 50.0g that this extracting solution obtains by filter paper filtering as measuring solution.
Begin most only to use physiological saline, the NaOH aqueous solution titration of using 0.1N then is to pH10, afterwards, obtains sky titer ([bNaOH] ml, [bHCl] ml) with the HCl aqueous solution titration of 0.1N to pH2.7.
Carry out same titration operation to measuring solution, try to achieve titer ([NaOH] ml, [HCl] ml).
For example, when vinylformic acid and its sodium salt form absorbent resin,, can calculate solvable component and neutralization ratio in the absorbent resin according to following formula based on its weight-average molecular weight and the titer that obtains according to aforesaid operations.
[several 2]
In addition, in flow measurement in solvable minute of aqueous polymers, use to form admittedly and divide 1.00g, dipping is 24 hours in physiological saline, except the correction of when calculating solvable component, carrying out solid formation branch, and other carry out the same with absorbent resin.
[GEX value]
The GV value of base polymer represents that with y (g/g) when solvable component was represented with x (weight %), the GEX value defined with following formula.
The GEX value=(y-15)/ln (x)
Ln (x): the natural logarithm of x
The GEX value be with a parametric representation in the relation of GV value and solvable component, the value of the evaluation that the conduct as good, many that solvable component is few in the ratio with the GV value is bad, this value big more performance high more.
[remaining monomeric mensuration]
Add the 0.5g absorbent resin in the 1000g deionized water, after under agitation extracting with 2 hours, leach with the absorbent resin of filter paper with the expansion gelation, amount of monomer remaining in the filtrate is analyzed with liquid chromatography.On the other hand, the monomer standardized solution of concentration known is carried out same analysis, the inspection amount line that obtains is considered the dilution ratio of filtrate as external perimysium reference, obtains the remaining amount of monomer in the absorbent resin.
In addition, in the remaining monomer of aqueous polymers was measured, the solid formation of use divided 0.5g, and dipping time is 24 hours in deionized water, except the correction of when calculating remaining monomer, carrying out solid formation branch, and other carry out the same with absorbent resin.
[the solid formation of aqueous polymers divides the mensuration of concentration]
The part of the aqueous polymers that will take out from polymerizer cuts in a small amount cooling rapidly, will put into culture dish with the aqueous polymers 5g of the rapid sectionalization of scissors, calculates in dry 24 hours in 180 ℃ of moisture eliminators.The solid formation branch concentration of particle shape aqueous polymers is that sample 5g is put into culture dish, what dry 24 hours calculated in 180 ℃ of moisture eliminators.
[calculating of concentration ratio]
The solid formation branch concentration of the aqueous polymers that polymerization generates is divided the ratio (concentration ratio) of concentration with the solid formation in the monomer solution.Here, the solid formation branch in the monomer solution is meant monomer and other additives, not moisture or solvent.For example, the solid formation in the monomer solution divides concentration 40 weight %, when the solid formation branch concentration of the aqueous polymers of generation is 48 weight %, and concentration ratio=48/40=1.20.
[mensuration that adds the absorption multiplying power of depressing (AAP)]
The plastics that melting the internal diameter 60mm of stainless steel 400 purpose wire nettings (width of mesh 38m) in the bottom support that on the bottom web of cylinder, homogeneous scatters absorbent resin 0.9g, adds 20g/cm with respect to the absorbent resin homogeneous thereon 2The loading of (with respect to 1.96kPa), the adjustment gross weight is 565g, does not produce the gap between the wall of the support cylinder that mounting and external diameter are slightly littler than 60mm in order, and does not hinder piston and the loading that moves up and down, and measures the weight (Wa) of this determinator same form.
Place the glass filter of diameter 90mm in the inboard of the Petri dish of diameter 150mm, the NaCl aqueous solution that adds 0.9 weight % reaches the height with glass filter surface same level.Place diameter 90mm filter paper thereon, make surperficial complete wetting, and remove excess liq.
The said determination device same form is loaded on the above-mentioned wet filter paper, under loading, absorbs liquid.After 1 hour the determinator same form picked up and remove, measure its weight (Wb) again.
Adding the absorption multiplying power of depressing (AAP) calculates with following formula.
[several 3]
[mensuration of polymerization system temperature]
In order to measure the temperature of the fast system of temperature variation, use (strain) キ one ェ Application ス (Keyence) system PC card-type data gathering system NR-1000, the heat transfer galvanic couple is placed on the polymerization system center, in 0.1 second sampling period, measure.Can read polymerization initiation temperature, peak temperature (being up to Da Wendu) from the gained temperature time curve.
[polymerization time]
Monomer solution is put into aggregation container, mensuration begins condition (when using photolysis type initiator, when rayed begins, when not using photolysis type initiator from possessing polymerization, when monomer solution and polymerization starter are put into aggregation container), to the time that arrives till the peak temperature.That is, measure (induction time)+(polymerization began to the time that arrives peak temperature).
[polymerization intensification ratio]
Polymerization heat up than be meant the observed Δ T of polymerization system (top temperature that arrives in the polymerization and the difference of polymerization initiation temperature ℃) and theoretical Δ T (℃) ratio.That is,
Polymerization intensification ratio=(observed Δ T (℃))/(theoretical Δ T (℃))
Here, theoretical Δ T (℃)=(monomer mol) * (1.85kcal/mol)/(in the monomer solution solid form divide (kg) * 0.5 (kcal/ ℃/kg)+monomer solution in r water (kg) * 1.0 (kcal/ ℃/kg))
[mensuration of soluble oxygen content in the monomer solution]
Use determinator (セ Application ト ラ Le science (strain) system DO メ one タ one UD-1 type), synthetic monomer solution in nitrogen atmosphere, stirred reposefully, make not press from both sides to add bubble, use simultaneously ice-cooled, the soluble oxygen content when measuring fluid temperature and being 50 ℃.
[neutralization ratio rising]
The difference of the neutralization ratio of base polymer and monomeric neutralization ratio is represented with point.For example, the neutralization ratio of base polymer is 65 moles of %, and when monomeric neutralization ratio was 60 moles of %, neutralization ratio rose to 5 points.
[mensuration of expansion multiplying power in the polymerization]
Because water seethes with excitement, polymerization system can expand sometimes during polymerization.The cm scale that the inherent portraitlandscape of aggregation container is marked with the size during maximum swelling in the visual observations polymerization, is obtained its volume, calculates the ratio with the volume of monomer solution.That is,
The volume of the maximum volume/monomer solution in the expansion multiplying power in the polymerization (doubly)=polymerization system
[particle size distribution of particle shape aqueous polymers]
The particle shape aqueous polymers of about 300g is packed into behind the Port リ bag, add ァ ェ ロ ジ Le R-972 (Japanese ァ ェ ロ ジ Le (strain) system, the sub-shape silicon oxide of hydrophobic particulate) 1g, mix, rub well with hand.Use the standard sieve of internal diameter 20cm and Ro-Tap formula sieve vibrator to vibrate 10 minutes the material after rubbing.
According to the water ratio of particle shape aqueous polymers, cohesion during the sieve vibration is difficult to measure correct size-grade distribution, and therefore adding ァ ェ ロ ジ Le R-972 prevents aggegation again, measures simultaneously.
[can dissolve test method(s)]
Absorbent resin has the form of the crosslinked body after basic water-soluble polymers is crosslinked.The test method of decomposing easily when being used to observe this absorbent resin and being exposed to decomposition condition is that this can dissolve test method.Therefore, in the enforcement, the decomposition condition according to exposing is not limited to and must has consistent tendency with this laboratory method.This test method by washing, is graded solvable one-tenth and is washed away, obtains from the gel of crosslinked body formation, by its irradiation ultraviolet radiation is decomposed.Obtain the quantitative target that crosslinked body itself decomposes easy degree by this evaluation method.Order as shown below.
1. with the absorbent resin classification, divide the material of getting 300 μ m～850 μ m.
2. branch is got in the 100cc ion exchanged water of product 0.500g in the cylindrical container of PP (polypropylene) system and disperseed, expand.At this moment, use magnetic stirrer (600rpm) to stir simultaneously.
3. stirred 2 hours in normal-temperature continuous.
4. this dispersion liquid is put on the circular standard sieve (mesh 300 μ m) of diameter 20cm.Remove moisture when beaing sieve, gel remaining on the sieve is put back in the PP rounding cylindrical container once more, add ion exchanged water and make total amount reach 1000cc, restir 2 hours with hand.
5. should clean operation and carry out 3 times, put into the glass culture dish of diameter 153mm removing gel behind the moisture.
6. mercuryvapour lamp H400BL (Toshiba's ラ ィ テ ッ Network (strain) system) is surrounded with lampshade SN-4042A (Toshiba's ラ ィ テ ッ Network (strain) system), be connected with mercuryvapour lamp stabilizer H4T1B51 (rock rugged electric (strain) system) and open, place culture dish from the face below the 18cm of mercuryvapour lamp lower end.The 18cm place measures the irradiation energy with ultraviolet integrating quantorecorder UIT-150 (ゥ シ ォ electric (strain) system) under mercuryvapour lamp, is 40mW/cm 2
7. the gel on the culture dish is used mercury light irradiation 30 minutes.
8. postradiation culture dish content is put back in the PP rounding cylindrical container, adding ion exchanged water to total amount is 1000cc, stirs 2 hours.Carry out and above-mentioned 4,5 same operations, clean 3 times.
9. standard sieve (mesh 300 μ m) is gone up the glass culture dish that remaining gel is put into diameter 153mm,, obtained solid formation component (a) in dry 5 hours of 180 ℃ moisture eliminators.
10. in addition, the gel (UV pre-irradiation) that obtains for the operation of carrying out above-mentioned 1～5 is according to obtaining solid formation component (b) with above-mentioned 9 same quadrat method.
11. can dissolve survival rate can calculate by dissolving survival rate=a/b * 100 (%).
Embodiment 1
In the stainless steel beaker of internal diameter 10cm, cover the lid of the foamed styrene system that is equipped with nitrogen ingress pipe, vapor pipe, thermometer, further whole stainless steel beaker is encased with the lagging material foamed styrene.To the acrylic acid aqueous solution 40.6g that wherein puts into the 80 weight % that dissolved polyethyleneglycol diacrylate (number-average molecular weight 478) 0.09g, stir with magnetic stirrer on one side, add the product of 48 weight % aqueous sodium hydroxide solution 28.2g on one side, neutralize with ion exchanged water 31.0g dilution.Interior temperature reaches 90 ℃.The neutralization ratio of this monomer solution is 75 moles of %.When importing nitrogen, when wherein adding 10 weight % aqueous solution 0.45g of Sodium Persulfate, begin polymerization (90 ℃ of polymerization initiation temperatures) rapidly, when producing water vapour, reach polymerization peak temperature (108 ℃).Reach from adding sodium persulfate aqueous solution that the required time is that polymerization time is 2 minutes till the polymerization peak temperature.After arriving the polymerization peak temperature, keep keeping warm mode 5 minutes, take out aqueous polymers scissors sectionalization afterwards.Begin to need 7 minutes from adding polymerization starter to taking out aqueous polymers.With the aqueous polymers after the sectionalization on 170 ℃ of hot air dryers dry 40 minutes, afterwards with desk-top pulverizer pulverizing.Then, with the screen fractionation crushed material of mesh 600m and 300m, obtain the base polymer (1) that major part has particle footpath 300～600m.
The GV of base polymer (1) is 47g/g, and solvable component is 10 weight %, and remaining monomer is 300ppm, and neutralization ratio is 77 moles of %.In addition, the solid formation branch concentration of aqueous polymers is 48 weight % after the sectionalization.Concentration ratio is 1.20.Then, with respect to (1) 100 part of base polymer, with form liquid and mix by 0.05 part of ethylene glycol diglycidylether, 1 part of propylene glycol, 2 parts of surface crosslinking agents that form of water, with the mixture that obtains heat treated 40 minutes in 80 ℃ drying machine, obtain the surface-crosslinked absorbent resin (1) that near surface is crosslinked.
The GV of surface-crosslinked absorbent resin (1) is 39g/g, and AAP is 38g/g.
The result is as shown in table 1.
In addition, the side photo of the aqueous polymers that obtains of embodiment 1 as shown in Figure 2.There are horizontal bar, long 1cm in the photo central authorities below of Fig. 2.
Comparative example 1
To in 20 ℃ water-bath, flood with used identical poly-unit among the embodiment 1 at the lid that covers the foamed styrene system that is equipped with nitrogen ingress pipe, vapor pipe, thermometer on the stainless steel beaker, to the monomer solution that wherein adds similarly to Example 1, import nitrogen on one side, Yi Bian add the L-aqueous ascorbic acid 0.45g of Sodium Persulfate 10 weight % aqueous solution 0.45g and 0.1 weight %.Begin polymerization after 7 minutes.Carry out polymerization simultaneously with 20 ℃ water-bath refrigerative, peak temperature reaches 60 ℃.Afterwards, replace, heated 30 minutes with 70 ℃ water-baths.
Afterwards, with aqueous polymers taking-up scissors sectionalization.Begin to need 62 minutes from adding the polymerization starter class to taking out aqueous polymers.With the aqueous polymers after the sectionalization on 170 ℃ of hot air dryers dry 40 minutes, afterwards with desk-top pulverizer pulverizing.Then, with the screen fractionation crushed material of mesh 600m and 300m, obtain the comparison basis polymkeric substance (1) that major part has particle footpath 300～600m.
The GV of comparison basis polymkeric substance (1) is 36g/g, and solvable component is 11 weight %, and remaining monomer is 300ppm, and neutralization ratio is 75 moles of %.In addition, the solid formation branch concentration of aqueous polymers is 42 weight % after the sectionalization.Concentration ratio is 1.05.
Then, with respect to (1) 100 part in comparison basis polymkeric substance, with by 0.05 part of ethylene glycol diglycidylether, 1 part of propylene glycol, the surface crosslinking agent of 2 parts of formation of water is formed liquid and is mixed, with the mixture that obtains heat treated 40 minutes in 80 ℃ drying machine, obtain the comparison surface cross-linking of water-absorbing resin (1) that near surface is crosslinked.
The GV of comparison surface cross-linking of water-absorbing resin (1) is 28g/g, and AAP is 26g/g.
The result is as shown in table 1.
Embodiment 1 and comparative example 1, monomer composition, amount of initiator etc. are identical, have only polymerization initiation temperature (embodiment 1 is 90 ℃, and comparative example 1 is 20 ℃) different with afterwards temperature variation.The performance of gained base polymer, absorbent resin, embodiment 1 is outstanding.Though reason is also not too clear and definite, the present inventor is presumed as follows.
When 20 ℃ of beginning polymerizations, too high in the polymericular weight that the low stage of percent polymerization generates, linking agent consumes big at the polymerization initial stage, therefore cause the low (reference: Crosslinker Reactivityand the Structure of Superabsorbent Gels relatively of GV, D.J.Arriola et al., J.Appl.Polym.Sci.63,439-451 (1997)), 90 ℃ of beginning polymerizations, suppress the molecular weight of the polymkeric substance that generates in the low stage of percent polymerization, also just suppressed the reduction of GV.
Embodiment 2
By with 83.5 parts in vinylformic acid, 48.5 62.1 parts of the weight %NaOH aqueous solution, 54.3 parts of ion exchanged waters, as 0.11 part of polyethyleneglycol diacrylate (number average degree of polymerization of oxyethane=8) and initiator 2-hydroxy-2-methyl-1-phenyl-propane-0.01 part of mixing of 1-ketone of linking agent, make the monomer solution of monomer concentration 50 weight %, 65 moles of % of neutralization ratio.In the degassing under the nitrogen atmosphere after 30 minutes, the culinary art that is placed on 90 ℃ is injected the stainless steel container made of the teflon coatings of the bottom surface 200 * 260mm that imports nitrogen with (containing flourish hall system in NEO HOTPLATE HI-1000 (strain) well) on the electric furnace with this solution.When monomer solution was warming up to 60 ℃, (4 of the system FL6BLB of ラ ィ テ ッ Network society of (strain) Toshiba) carried out 10 minutes (light quantity 900mJ/cm of uviolizing with the invisible light luminescent lamp 2), obtain the aqueous polymers of the about 3mm of thickness.60 ℃ of polymerization initiation temperatures, top temperature is 110 ℃ in the polymerization, polymerization time 80 seconds, 5 times of expansion multiplying powers.After the uviolizing, take out aqueous polymers, use the scissors sectionalization,, pulverize with desk-top pulverizer afterwards at once 170 ℃ of warm air dryings of advancing 30 minutes.Then, crushed material obtains the base polymer (2) that major part has particle footpath 300～600m with the screen fractionation of mesh 600m and 300m.
The GV of base polymer (2) is 58g/g, and solvable component is 16 weight %, and neutralization ratio is 68 moles of %, and remaining monomer is 2200ppm.In addition, the solid formation branch concentration of aqueous polymers is 60 weight %, and concentration ratio is 1.20.
Then, with respect to (2) 100 parts of base polymers, with form liquid and mix by 0.05 part of ethylene glycol diglycidylether, 1 part of propylene glycol, 2 parts of surface crosslinking agents that form of water, with the mixture that obtains heat treated 40 minutes in 80 ℃ drying machine, obtain the surface-crosslinked absorbent resin (2) that near surface is crosslinked.
The GV of surface-crosslinked absorbent resin (2) is 42 (g/g), and AAP is 36 (g/g).
The result is as shown in table 1.
Embodiment 3
Modulate vinylformic acid 139.5g respectively, polyethyleneglycol diacrylate (number-average molecular weight 478) 0.09g, mix the solution (A) that forms with 2-hydroxy-2-methyl-1-phenyl-propane-1-ketone 0.02g, 48.5 weight %NaOH aqueous solution 95.8g dilutes with ion exchanged water 61.2g, the NaOH aqueous solution (B) that further adds Versenex 80 0.02g, the degassing is 30 minutes under nitrogen atmosphere.When stirring, (A) added mixing in (B) at unlimited system-gas with magnetic stirrer.The mixing initial stage is seen and separates out material but very fast dissolving, obtains utilizing neutralization heat and dissolving hydrothermal solution temperature to rise to about 90 ℃ monomer solution (monomer concentration 55 weight %, 60 moles of % of neutralization ratio).Further in this monomer solution, add 10 weight % sodium persulfate aqueous solution 0.58g, the culinary art that is placed on 90 ℃ after the stirring several seconds is immediately injected the stainless steel can type container (about 64 ℃ of surface temperature) (the about 5mm of sample path length) that inner face posts the bottom surface 200 * 260mm of silicon plate with on the electric furnace with open system.Stainless steel can type container is of a size of bottom surface 200 * 260mm, above 560 * 460mm, high 140mm, center section are trapezoidal, are open above.Using invisible light mercuryvapour lamp (peak wavelength 352nm, shape H400BL are contained among the projector MT-4020, and lamp, projector all are ラ ィ テ ッ Network society of (strain) Toshiba systems) to carry out uviolizing afterwards at once begins polymerization.Produce water vapour, carry out polymerization when the left and right sides is expanded foamed up and down, shrink back the life size peer-level afterwards.The maximum about 30 times of post shrinkage to the monomer solution volume of aqueous polymers expansion are inferred in range estimation.When aqueous polymers expanded, thin aqueous polymers rose and reaches the sloping portion of container side, during contraction, returned by former direction, to forming the aqueous polymers stop motion bigger than bed-plate dimension.This expansion is contracted in about 1 minute and finishes, and is taking out aqueous polymers in the time of 2 minutes with the UV irradiation.May be read into polymerization initiation temperature from the record of the temperature variation of polymerization system is 88 ℃, and being up to Da Wendu is 111 ℃.The gained aqueous polymers is because bubble size former state and vibrational state form the form of many gauffers.This aqueous polymers is pulverized with perpendicular type pulverizer (shape VM27-S (strain) ォ リ ェ Application ト society system, net (ス Network リ one Application) footpath 8mm), obtained mobile particle shape aqueous polymers (3).
The GV of aqueous polymers (3) is 33g/g, and solvable component is 6 weight %, and remaining monomer is 600ppm, and formation branch concentration is 70 weight % admittedly, and concentration ratio is 1.27.
Then, aqueous polymers (3) was carried out warm air drying 20 minutes at 170 ℃, dry thing is pulverized with roller mill.Then, crushed material obtains the base polymer (3) that major part has the weight average particle diameter 360 μ m of particle footpath 150～850 μ m with the screen fractionation of mesh 850 μ m and 15 μ m.
The GV of base polymer (3) is 48g/g, and solvable component is 24 weight %, 65 moles of % of neutralization ratio, and remaining monomer is 200ppm.In addition, when the particle of base polymer (3) was used microscopic examination, though foaming is followed in polymerization, because bubble size is bigger, most particle became the noncrystal shape that does not contain bubble.
Then, with respect to (3) 100 parts of base polymers, with form liquid and mix by 0.03 part of ethylene glycol diglycidylether, 1 part of propylene glycol, 5 parts of surface crosslinking agents that form of water, with the mixture that obtains heat treated 1 hour in 80 ℃ the drying machine in encloses container, obtain the surface-crosslinked absorbent resin (3) that near surface is crosslinked.
The GV of surface-crosslinked absorbent resin (3) is 34g/g, and AAP is 35g/g.
Further, with respect to (3) 100 parts of base polymers, with form liquid and mix by 0.03 part of ethylene glycol diglycidylether, 1 part of propylene glycol, 3 parts in water, 0.9 part of surface crosslinking agent that forms of Virahol, the mixture that obtains was handled 20 minutes in the vessel in heating of 170 ℃ oil bath heating, obtained the surface-crosslinked absorbent resin (3a) that near surface is crosslinked.
The GV of surface-crosslinked absorbent resin (3a) is 34g/g, and AAP is 35g/g.
The result is as shown in table 1.
In addition, the side photo of the aqueous polymers that embodiment 3 obtains as shown in Figure 3, above photo as shown in Figure 4, below photo as shown in Figure 5.Below the photo central authorities of Fig. 3, Fig. 4 and Fig. 5, horizontal bar is arranged, long 1cm.
Embodiment 4
Carry out same polymerization with embodiment 3, fan is used in the water vapour evaporation, at ice-cooled importing electrical condenser down, collects.2 collections are carried out in this operation obtained aqueous solution 60g, wherein contain vinylformic acid 3.4 weight %.
Except will containing ion exchanged water displacement more than half use of acrylic acid recycle-water with embodiment 3, other and embodiment 3 carry out same operation.Obtain base polymer (4), physical property values is as shown in table 1.
Embodiment 5
According to embodiment 3, except linking agent polyethyleneglycol diacrylate (number-average molecular weight 478) 0.09g being changed to Viscoat 295 (molecular weight 296) 0.14g, carrying out same operation with embodiment 3 and obtain base polymer (5).With respect to (5) 100 parts of base polymers, with by 1 part of propylene glycol, 1,0.5 part of 4-butyleneglycol, 3 parts in water, the surface crosslinking agent of 1 part of formation of Virahol is formed liquid and is mixed.The mixture that obtains 210 ℃ of heat treated 40 minutes, is obtained surface-crosslinked absorbent resin (5).
The result is as shown in table 1.
In addition, the side photo of the aqueous polymers that obtains of embodiment 5 as shown in Figure 6.Below the central authorities of Fig. 6 photo, horizontal bar is arranged, long 1cm.
Embodiment 6
(5) 100 parts of the base polymers that embodiment 5 is obtained, and by 3 parts of NSC 11801,3 parts in water, the surface crosslinking agent of 1 part of formation of Virahol is formed liquid and is mixed.Said mixture 210 ℃ of heat treated 40 minutes, is obtained surface-crosslinked absorbent resin (6).
The result is as shown in table 1.
[table 1]
? Embodiment 1 Embodiment 2 Embodiment 3 Embodiment 4 Embodiment 5 Embodiment 6 Comparative example 1
Monomer solution concentration (weight %) 40? 50? 55? 55? 55? 55? 40?
Monomeric neutralization ratio (mole %) 75? 65? 60? 60? 60? 60? 75?
The thing peak temperature (℃) 90? 60? 88? 87? 89? 89? 20?
ΔT(℃)? 108? 110? 111? 112? 110? 110? 60?
Polymerization time (second) 18? 50? 22? 25? 21? 21? 40?
The solid formation of aqueous polymers divides concentration (weight %) 120? 80? 39? 48? 43? 43? 1500?
Concentration ratio 48? 60? 70? 69? 68? 68? 42?
The GV of base polymer (g/g) 1.20? 1.20? 1.27? 125? 1.24? 1.24? 1.05?
The solvable component (weight %) of base polymer 47? 58? 48? 50? 29? 29? 36?
The neutralization ratio of base polymer (mole %) 10? 16? 24? 23? 4? 4? 11?
The GEX value of base polymer 13.9? 15.5? 104? 11.2? 10.1? 10.1? 8.8?
The neutralization ratio of base polymer (mole %) 77? 68? 65? 64? 64? 64? 75?
Remaining monomer (ppm) 300? 2200? 200? 300? 270? 270? 300?
The GV of surface-crosslinked absorbent resin (g/g) 39? 42? 34? -? 25? 23? 28?
The AAP of surface-crosslinked absorbent resin (g/g) 38? 36? 35? -? 26? 24? 26?
[0296]Embodiment 7～10
Except using the temperature change polymerization initiation temperature of electric furnace by temperature and the culinary art of adjusting monomer solution, carry out same polymerization and operation afterwards according to embodiment 3, obtain the base polymer (base polymer (7)～(10)) of embodiment 7～10 respectively.The results are shown in table 2.
In addition, the side photo of the aqueous polymers that obtains of embodiment 7 as shown in Figure 7.In addition, cut the aqueous polymers of a part of embodiment 7, the photo of the gel after expanding with water channel water as shown in Figure 8.In the photo of Fig. 8, the aqueous polymers that exists beyond the culture dish has and the identical section of section that cuts with the aqueous polymers before the tap water swelling.There are vertical rod, long 1cm in Fig. 7 and Fig. 8 photo lower left.
[table 2]
? Embodiment 7 Embodiment 8 Embodiment 9 Embodiment 10 Comparative example 2
Monomer solution concentration (weight %) 55? 55? 55? 55? 70?
Monomeric neutralization ratio (mole %) 60? 60? 60? 60? 75?
Polymerization initial value temperature (℃) 88? 73? 60? 44? 56?
The polymerization peak temperature (℃) 111? 139? 137? 121? 145?
ΔT(℃)? 23? 66? 73? 75? 89?
Polymerization time (second) 45? 60? 86? 110? 35?
The solid formation of aqueous polymers divides concentration (weight %) 71? 68? 66? 64? 89?
Concentration ratio 1.29? 1.24? 1.20? 1.16? 1.27?
The GV of base polymer (g/g) 51? 48? 45? 47? 23?
The solvable component (weight %) of base polymer 25? 30? 28? 29? 50?
The GEX value of base polymer 11.2? 9.7? 9.0? 9.5? 2.0?
The neutralization ratio of base polymer (mole %) 65? 65? 65? 64? 77?
Neutralization ratio rising (point) 5? 5? 5? 4? 2?
Remaining monomer (ppm) 300? 2000? 1600? 500? 5900?
In addition, for the base polymer of embodiment 3 and embodiment 7～10, the figure of expression polymeric reaction temperature and timing relationship as shown in Figure 1.
Embodiment 7～10 is made up of same monomer, and just polymerization initiation temperature becomes 88 ℃, 73 ℃, 60 ℃, 44 ℃ respectively.Starting temperature is high more, and the performance of base polymer is good more, and the solid formation branch concentration of aqueous polymers also becomes high more.In addition, the peak temperature that starting temperature is high is low.Though the reason of this phenomenon is also indeterminate, the present inventor is presumed as follows.
Because if polymerization initiation temperature is low, till beginning to reach boiling, generate hard aqueous polymers, boiling temperature uprises, and promptly peak temperature also uprises, and the sound that breaks is also very big.And if the polymerization initiation temperature height does not generate hard aqueous polymers till beginning to reach boiling, the monomer solution that viscosity is high not only seethes with excitement but also carries out bigger foaming, it is big that surface-area becomes, water vapour volatilizees well, has suppressed peak temperature, also uprises Gu form branch concentration.Sound does not almost break.
Comparative example 2
Vinylformic acid 72.1g is added among the ion exchanged water 22.2g, further to wherein add successively as the potassium hydroxide 49.5g of the purity 85% of neutralizing agent and, N as the divinyl compounds, N '-methylene bis acrylamide 0.01g, the potassium acrylate solution (75 moles of % of neutralization ratio) of modulation mix monomer concentration 70 weight %.
Above-mentioned synthetic solution is incubated down at 70 ℃, with 18 weight % aqueous solution 2.9g of itself and ammonium persulphate (with respect to potassium acrylate, free vinylformic acid and N, the total weight of N '-methylene bis acrylamide (monomer component total weight) is 0.5 weight %) and 30.6 weight % aqueous solution 1.7g (0.5 weight %) of sodium bisulfite mix, pour this mixed solution into stainless steel beaker (capacity 2L, φ 135mm), form the stratiform that thickness is about 10mm.After about 7 seconds, polyreaction begins, this react about 1 minute intact or, top temperature is 145 ℃ therebetween.
The gained aqueous polymers is a solid state, is the material of pulverizing easily, obtains comparison basis polymkeric substance (2).Its solid formation divides concentration 89 weight %, and GV is 23g/g, and solvable component is 50 weight %, and neutralization ratio is 77 moles of %, and remaining monomer is 5900ppm.
The result is as shown in table 2.
This comparative example is to prepare according to the embodiment 1 that the spy opens clear 58-71907 (waste river chemistry).Solid as can be known formation branch concentration one reaches 89 weight %, and solvable component then significantly increases.
Embodiment 11
Modulate vinylformic acid 139.5g, polyethyleneglycol diacrylate (number-average molecular weight 478) 0.09g and 2-hydroxy-2-methyl-1-phenyl-propane-1-ketone 0.02g respectively and mix the solution (A) that forms, 48.5 weight %NaOH aqueous solution 95.8g dilutes with ion exchanged water 64.1g, the NaOH aqueous solution (B) that further adds Versenex 80 0.02g, the degassing is 30 minutes under nitrogen atmosphere.When stirring, (A) added mixing in (B) at unlimited system one gas with magnetic stirrer.The mixing initial stage is seen and separates out material but very fast dissolving, obtains utilizing neutralization heat and dissolving hydrothermal solution temperature to rise to about 85 ℃ monomer solution (monomer concentration 55 weight %, 60 moles of % of neutralization ratio).Further in this monomer solution, add 10 weight % sodium persulfate aqueous solution 0.58g, the culinary art that is placed on 90 ℃ after the stirring several seconds is immediately injected the stainless steel can type container (about 64 ℃ of surface temperature) (the about 5mm of sample path length) that inner face posts the bottom surface 200 * 260mm of silicon plate with on the electric furnace with open system.Stainless steel can type container is of a size of bottom surface 200 * 260mm, above 560 * 460mm, high 140mm, center section are trapezoidal, are open above.Using invisible light mercuryvapour lamp (peak wavelength 352nm, shape H400BL, ラ ィ テ ッ Network society of (strain) Toshiba system) to carry out the UV irradiation afterwards at once begins polymerization.Produce water vapour, the left and right sides is expanded foamed up and down, carries out polymerization simultaneously, shrinks back the life size peer-level afterwards.The maximum about 30 times of post shrinkage of extremely estimating monomer solution volume when inferring of aqueous polymers expansion.When aqueous polymers expanded, thin aqueous polymers rose and reaches the sloping portion of container side, during contraction, returns by former direction, forms the aqueous polymers stop motion bigger than bed-plate dimension.This expansion is contracted in about 1 minute and finishes, and is taking out aqueous polymers in the time of 2 minutes with the UV irradiation.In addition, it is 82 ℃ that the chart of measuring from thermometer may be read into polymerization initiation temperature, and being up to Da Wendu is 113 ℃.Gained aqueous polymers (11) is the form of many gauffers, divides concentration 70 weight % Gu form.Concentration ratio is 1.27.This aqueous polymers (11) is pulverized with perpendicular type pulverizer (shape VM27-S, net (ス Network リ one Application) footpath 3mm, (strain) ォ リ ェ Application ト society system), obtained having mobile particle shape aqueous polymers (11).
The weight average particle diameter of particle shape aqueous polymers (11) is 1mm, and GV is 33g/g, and solvable component is 6 weight %, and remaining monomer is 600ppm, is 71 weight % Gu form branch concentration.
Then, particle shape aqueous polymers (11) was carried out warm air drying 20 minutes in 170 ℃ moisture eliminator, dry thing is pulverized with roller mill.Then, crushed material obtains the base polymer (11) that major part has the weight average particle diameter 360 μ m of particle footpath 150～850 μ m with the screen fractionation of mesh 850 μ m and 150 μ m.
The GV of base polymer (11) is 48g/g, and solvable component is 24 weight %, 65 moles of % of neutralization ratio, and remaining monomer is 200ppm.In addition, when the particle of base polymer (11) is used microscopic examination, though foaming is followed in polymerization, may be because this bubble size be bigger, most particle becomes the amorphousness shape that does not contain bubble.
Then, with respect to (11) 100 parts of base polymers, mix 0.03 part of ethylene glycol diglycidylether, 1 part of propylene glycol, the surface crosslinking agent of 5 parts of formation of water is formed liquid, with the mixture that obtains heat treated 1 hour in 80 ℃ the drying machine in encloses container, obtain the surface-crosslinked absorbent resin (11) that near surface is crosslinked.
The GV of surface-crosslinked absorbent resin (11) is 34g/g, and AAP is 32g/g.
Further, with respect to (11) 100 parts of base polymers, mix the surface crosslinking agent of 0.03 part of ethylene glycol diglycidylether, 1 part of propylene glycol, 3 parts in water, 0.9 part of formation of Virahol and form liquid, the mixture that obtains was handled 20 minutes in the vessel in heating that heats with 170 ℃ oil bath, obtained the surface-crosslinked absorbent resin (11a) that near surface is crosslinked.
The GV of surface-crosslinked absorbent resin (11a) is 34g/g, and AAP is 35g/g.
Embodiment 12
Modulate vinylformic acid 308.2g respectively, polyethyleneglycol diacrylate (number-average molecular weight 478) 0.20g, mix the solution (A) that forms with 2-hydroxy-2-methyl-1-phenyl-propane-1-ketone 0.04g, 48.5 the NaOH aqueous solution (B) that weight %NaOH aqueous solution 194.1g forms with ion exchanged water 97.0g dilution, when stirring, (A) added mixing in (B) at unlimited system one gas with magnetic stirrer.The mixing initial stage is seen and separates out material but very fast dissolving, obtains monomer solution (monomer concentration 60 weight %, 55 moles of % of neutralization ratio, 102 ℃ of temperature).(the modulation of same this monomer solution of keeping straight in other a collection of, during the time-and-motion study soluble oxygen content, be 0.7ppm) further in this monomer solution, add 10 weight % sodium persulfate aqueous solution 1.3g, the culinary art that is placed on 90 ℃ after the stirring several seconds is very soon injected the stainless steel can type container that inner face posts the silicon plate with on the electric furnace with open system.Stainless steel can type container is of a size of bottom surface 200 * 260mm, above 560 * 460mm, high 140mm, center section are trapezoidal, are open above.Using invisible light mercuryvapour lamp (peak wavelength 352nm, shape H400BL, ラ ィ テ ッ Network society of (strain) Toshiba system) to carry out the UV irradiation afterwards at once begins polymerization.Produce water vapour, carry out polymerization (expansion multiplying power is 40 times) when the left and right sides is expanded foamed up and down.Taking out aqueous polymers in the time of 2 minutes with the UV irradiation.The solid formation branch concentration of this aqueous polymers is 77 weight %.This aqueous polymers with perpendicular type pulverizer (shape VM27-S, net (ス Network リ one Application) footpath 3mm, (strain) ォ リ ェ Application ト society system), is pulverized with the net (ス Network リ one Application) of aperture 1mm, obtained having mobile particle shape aqueous polymers.With the screen fractionation of this particle shape aqueous polymers continuation, obtain the particle shape aqueous polymers (12) of weight average particle diameter 500 μ m with mesh 850 μ m and 150 μ m.
The GV of particle shape aqueous polymers (12) is 22g/g, and solvable component is 2 weight %, and remaining monomer is 600ppm, divides concentration 79 weight % Gu form.
Embodiment 13
Modulate vinylformic acid 279.0g respectively, polyethyleneglycol diacrylate (number-average molecular weight 478) 0.09g, mix the solution (A) that forms with 2-hydroxy-2-methyl-1-phenyl-propane-1-ketone 0.03g, the NaOH aqueous solution (B) that 48.5 weight %NaOH aqueous solution 191.54g form with ion exchanged water 128.2g dilution.When stirring, (A) added mixing in (B) at unlimited system one gas with magnetic stirrer.The mixing initial stage is seen and separates out material but very fast dissolving, obtains monomer solution (monomer concentration 55 weight %, 60 moles of % of neutralization ratio, 92 ℃ of temperature).(in other a collection of, carry out the modulation operations of this monomer solution equally, when measuring soluble oxygen content, be 1.4ppm) further in this monomer solution, add 10 weight % sodium persulfate aqueous solution 1.3g, the culinary art that is placed on 90 ℃ after the stirring several seconds is very soon injected the stainless steel can type container that inner face posts the silicon plate with on the electric furnace with open system.Stainless steel can type container is of a size of bottom surface 200 * 260mm, above 560 * 460mm, high 140mm, center section are trapezoidal, are open above.Using invisible light mercuryvapour lamp (peak wavelength 352nm, shape H400BL, ラ ィ テ ッ Network society of (strain) Toshiba system) to carry out the UV irradiation afterwards at once begins polymerization.Produce water vapour, carry out polymerization (expansion multiplying power is 35 times) when the left and right sides is expanded foamed up and down.Taking out aqueous polymers (is 69 weight % Gu form branch concentration) in the time of 2 minutes with the UV irradiation.This aqueous polymers with perpendicular type pulverizer (shape VM27-S, (strain) ォ リ ェ Application ト society system), is begun to pulverize with the net of aperture 3mm, further pulverize this crushed material, obtain having mobile particle shape aqueous polymers with the net of aperture 1mm.With the screen fractionation of this particle shape aqueous polymers continuation, obtain the particle shape aqueous polymers (13) (Gu forming branch concentration 70 weight %) of weight average particle diameter 610m with mesh 850 μ m and 150 μ m.
The GV of particle shape aqueous polymers (13) is 34g/g, and solvable component is 10 weight %, and remaining monomer is 700ppm.
Then, with respect to (13) 100 parts of particle shape aqueous polymers, mixing is by 0.02 part of ethylene glycol diglycidylether, and the surface crosslinking agent of 0.2 part of formation of propylene glycol is formed liquid, with the mixture that obtains in encloses container in 80 ℃ drying machine heat treated 1 hour.Though the particle aggegation after the heating becomes cake mass,, obtain the surface-crosslinked absorbent resin (13) that near surface is crosslinked in case easily be crushed to the particle shape by being cooled to room temperature.
The GV of surface-crosslinked absorbent resin (13) is 25g/g, and AAP is 23g/g, and remaining monomer 200ppm divides concentration 74 weight % Gu form.
Embodiment 14
After (11) 1 pieces of the aqueous polymers of many gauffers form that embodiment 11 is obtained roughly are cut to 4 with annular saw, drop into turbine cutting machine (タ one ボ カ ッ the タ one) (C-300 of net footpath 3mm, タ one ボ industry (strain) system) pulverizes, obtain particle shape aqueous polymers (14).With the aqueous polymers (11) of handling about 50kg in 30 minutes.
The solid formation branch concentration of gained particle shape aqueous polymers (14) is 71 weight %, weight average particle diameter 1.3mm.As follows with the size-grade distribution that Ro-Tap formula vibrator is tried to achieve.
The particle shape aqueous polymers 9 weight % that particle diameter 2mm is above
The particle shape aqueous polymers 38 weight % of the above not enough 2mm of particle diameter 1.4mm
The particle shape aqueous polymers 31 weight % of the above not enough 1.4mm of particle diameter 1mm
The particle shape aqueous polymers 19 weight % of the above not enough 1mm of particle diameter 0.5mm
The particle shape aqueous polymers 3 weight % of the not enough 0.5mm of particle diameter
Embodiment 15
Embodiment 14 usefulness turbine cutting machines (タ one ボ カ ッ タ one) are pulverized particle shape aqueous polymers (14) the input turbine cutting machine (タ one ボ カ ッ タ one) that obtains, and (TG 1, タ one ボ industry (strain) system) further pulverizes, obtain particle shape aqueous polymers (15).
The net footpath of turbo-mill (タ one ボ グ ラ ィ Application ダ one) is pulverized the weight average particle diameter and solid formation of back particle shape aqueous polymers (15) and is divided concentration as shown in table 4.
Embodiment 16
Particle shape aqueous polymers (14) and (15) are used fluidised bed moisture eliminator (Pulvis GB22, ャ マ ト science (strain) system), 180 ℃ of interior temperature, material 100 grams, the condition that the hot blast flow velocity is 0.35 cubic metre/minute is carried out drying.
In following table, the material temperature that has shown particle shape aqueous polymers (14) and (15) in the drying, dried solid formation divided concentration, after dry thing pulverizing, with drying particulate shaped polymer (14) that 300 μ m～600 μ m classifications obtain and the GV of (15), solvable component, remaining monomeric measured value, these values are as shown in table 3.
[table 3]
? Drying particulate shape aqueous polymers (14) Drying particulate shape aqueous polymers (15)
The material temperature of 1 minute time of drying (℃) 105? 90?
The material temperature of 2 minutes time of drying (℃) 140? 127?
The material temperature of 3 minutes time of drying (℃) 159? 145?
The material temperature of 5 minutes time of drying (℃) 171? 161?
The material temperature of 10 minutes time of drying ℃) 179? 173?
Solid formation divided concentration (weight %) after dry 10 minutes 95? 96?
GV(g/g)? 44? 42?
Solvable component (weight %) 18? 16?
Remaining monomer (ppm) 250? 300?
Embodiment 17
After (11) 1 pieces of the aqueous polymers of many gauffers form that embodiment 11 is obtained roughly are cut to 4 with annular saw, drop into the ロ one ト Block レ ッ Network ス (28/40Ro, ホ ソ カ ヮ ミ Network ロ Application (strain) system) of net footpath 2mm continuously.Treatment capacity is about 70kg/ hour.
After the pulverizing, capture with cyclone, the solid formation branch concentration of gained particle shape aqueous polymers (17) is 72 weight %, the about 1mm of weight average particle diameter.The size-grade distribution that particle shape aqueous polymers (17) is tried to achieve with the old-fashioned vibrator of Ro-Tap formula is as follows.
The particle shape aqueous polymers 1 weight % that particle diameter 2mm is above
The particle shape aqueous polymers 29 weight % of the above not enough 2mm of particle diameter 1.2mm
The particle shape aqueous polymers 35 weight % of the above not enough 1.2mm of particle diameter 0.85mm
The particle shape aqueous polymers 26 weight % of the above not enough 0.85mm of particle diameter 0.3mm
The particle shape aqueous polymers 9 weight % of the not enough 0.3mm of particle diameter
Embodiment 18
After (11) 1 pieces of the aqueous polymers of many gauffers form that embodiment 11 is obtained roughly are cut to 4 with annular saw, drop into the ロ one ト プ レ ッ Network ス (28/40Ro, ホ ソ カ ヮ ミ Network ロ Application (strain) system) of net footpath 5mm continuously.Treatment capacity is about 100kg/ hour.
After the pulverizing, capture with cyclone, the solid formation branch concentration of gained particle shape aqueous polymers (18) is 71 weight %, the about 2mm of weight average particle diameter.The size-grade distribution that particle shape aqueous polymers (18) is tried to achieve with the old-fashioned vibrator of Ro-Tap formula is as follows.
The particle shape aqueous polymers 6 weight % that particle diameter 2.8mm is above
The particle shape aqueous polymers 58 weight % of the above not enough 2.8mm of particle diameter 1.7mm
The particle shape aqueous polymers 29 weight % of the above not enough 1.7mm of particle diameter 0.85mm
The particle shape aqueous polymers 6 weight % of the above not enough 0.85mm of particle diameter 0.15mm
The particle shape aqueous polymers 1 weight % of the not enough 0.15mm of particle diameter
Then, the particle shape aqueous polymers (18) with this pulverizing drops into De ラ ィ マ ィ ス タ (ホ ソ カ ヮ ミ Network ロ Application (strain) system is pulverized and the exsiccant device simultaneously by hot blast and dispersion rotor).At this moment, 270 ℃ of hot blast temperatures, dispersion rotor are 3000rpm.
After the drying, capture with cyclone, the size-grade distribution of trying to achieve with the old-fashioned vibrator of Ro-Tap formula of gained particle shape aqueous polymers (18a) is as follows.
The particle shape aqueous polymers 1 weight % that particle diameter 2.8mm is above
The particle shape aqueous polymers 5 weight % of the above not enough 2.8mm of particle diameter 1.7mm
The particle shape aqueous polymers 24 weight % of the above not enough 1.7mm of particle diameter 0.85mm
The particle shape aqueous polymers 59 weight % of the above not enough 0.85mm of particle diameter 0.15mm
The particle shape aqueous polymers 11 weight % of the not enough 0.15mm of particle diameter
The solid formation of particle shape aqueous polymers (18a) divides concentration 94 weight %, weight average particle diameter 0.4mm.After the running, can't see dirt settling fully in De ラ ィ マ ィ ス タ inside.
The GV of the particle shape aqueous polymers (18a) of this drying, pulverizing is 40g/g, and solvable component is 15 weight %, and remaining monomer is 400ppm.
Embodiment 19
After (11) 1 pieces of the aqueous polymers of many gauffers form that embodiment 11 is obtained roughly are cut to 4 with annular saw, drop into desk dual-purpose type pulverizer (FDS type (strain) body ゃ こ produce, net footpath 1mm, the pulverizer of mallet formula mill type), but stop up, row does not come out at once.Therefore, connect precipitron ((strain) マ キ タ makes Wet-dry, and is professional with model 406) at relief outlet, the generation airflow makes it successfully to discharge in the pulverizer by making.The solid formation branch concentration of ejecta is 78 weight %, weight average particle diameter 650 μ m, and wherein, the following material of particle diameter 150 μ m is 70 weight %.
By ventilating when pulverizing, the moisture that heating produces during pulverizing is removed fast, owing to can lower the tackiness of material, makes to be crushed into possibility.
Embodiment 20
(11) 1 pieces of the aqueous polymers of many gauffers form that embodiment 11 is obtained drop into カ ッ タ one ミ Le ((strain) ホ one ラ ィ system, UG03-280LFT, net footpath 8mm) after roughly being cut to 4 with annular saw.In addition, this カ ッ タ one ミ Le is connected with fan (DF type fan, DF-3, air output 15m 3/ minute, (strain) ホ one ラ ィ system) and cyclone, the product of pulverizing obtains by the cyclone bottom.The solid formation branch concentration of the particle shape aqueous polymers (20) that pulverizing obtains is 72 weight %, the about 3mm of weight average particle diameter.The size-grade distribution that this particle shape aqueous polymers (20) is tried to achieve with the old-fashioned vibrator of Ro-Tap formula is as follows.
The particle shape aqueous polymers 17 weight % that particle diameter 4mm is above
The particle shape aqueous polymers 69 weight % of the above not enough 4mm of particle diameter 2mm
The particle shape aqueous polymers 13 weight % of the above not enough 2mm of particle diameter 1mm
The particle shape aqueous polymers 1 weight % of the not enough 1mm of particle diameter
Then, this particle shape aqueous polymers (20) being dropped into screen cloth grinding machine (メ ッ シ ュ ミ Le) ((strain) ホ one ラ ィ system, HA8-2542, net footpath 2mm) further pulverizes.The solid formation branch concentration that captures the particle shape aqueous polymers (20a) that obtains with cyclone is 75 weight %, weight average particle diameter 0.6mm.Treatment capacity is 130kg per hour.The size-grade distribution that this particle shape aqueous polymers (20a) is tried to achieve with the old-fashioned vibrator of Ro-Tap formula is as follows.
The particle shape aqueous polymers 0 weight % that particle diameter 1.4mm is above
The particle shape aqueous polymers 8 weight % of the above not enough 1.4mm of particle diameter 1mm
The particle shape aqueous polymers 17 weight % of the above not enough 1mm of particle diameter 0.85mm
The particle shape aqueous polymers 72 weight % of the above not enough 0.85mm of particle diameter 0.15mm
The particle shape aqueous polymers 3 weight % of the not enough 0.15mm of particle diameter
After the running, can't see dirt settling fully in screen cloth grinding machine (メ ッ シ ュ ミ Le) inside.
Embodiment 21
By mix 83.5 parts in vinylformic acid, 48.5 62.1 parts of the weight %NaOH aqueous solution, 54.3 parts of ion exchanged waters, as 0.11 part of the polyethyleneglycol diacrylate (number average degree of polymerization of oxyethane=8) of linking agent with as 0.01 part of the 2-hydroxy-2-methyl-1-phenyl-propane of initiator-1-ketone, make the monomer solution of 86 ℃ of monomer concentration 50 weight %, neutralization ratio 65mol%, temperature and (in a collection of in addition, similarly modulate this monomer solution, when measuring soluble oxygen content, be 3.0ppm).The culinary art that this monomer solution is placed on 90 ℃ is injected the teflon coatings stainless steel container made of the bottom surface 200 * 260mm that is connected with nitrogen with on the electric furnace.When monomer solution reaches 80 ℃, carry out 10 minutes (light quantity 780mJ/cm of uviolizing with the invisible light luminescent lamp 2), obtain the aqueous polymers (21) of the about 3mm of thickness.Divide concentration 60 weight % Gu form.Concentration ratio 1.20.Top temperature in this polymerization is 110 ℃.Aqueous polymers (21) is chopped up with perpendicular type pulverizer (shape VM27-S, net footpath 3mm, (strain) ォ リ ェ Application ト society system), obtain weight average particle diameter 1.6mm, Gu form the particle shape aqueous polymers (21) that divides concentration 61 weight %.This particle shape aqueous polymers (21) was carried out warm air drying 30 minutes in 170 ℃, pulverize with desk-top pulverizer.Then, with the screen fractionation of crushed material, obtain the base polymer (21) that major part has particle diameter 300～600 μ m with mesh 600 μ m and 300 μ m.
The GV of this base polymer (21) is 58g/g, and solvable component is 16 weight %, 68 moles of % of neutralization ratio, and remaining monomer is 2200ppm.
Then, with respect to (21) 100 parts of base polymers, with by 0.05 part of ethylene glycol diglycidylether, 1 part of propylene glycol, the surface crosslinking agent of 2 parts of formation of water is formed liquid and is mixed, with the mixture that obtains heat treated 40 minutes in 80 ℃ drying machine, obtain the surface-crosslinked absorbent resin (21) that near surface is crosslinked.
The GV of surface-crosslinked absorbent resin (21) is 42g/g, and AAP is 36g/g.
About the pulverizing of the aqueous polymers of embodiment 11～15 and 17～21, list in table 4.
[table 4]
? Aqueous polymers forms branch concentration (weight %) admittedly The machine for decomposing and smashing title Machine for decomposing and smashing network (mm) The solid formation of particle shape aqueous polymers divides concentration (weight %) The weight average particle diameter (mm) of particle shape aqueous polymers
Embodiment 11 70? Perpendicular type pulverizer 3? 71? 1?
Embodiment 12 77? Perpendicular type pulverizer 1? 79? 0.5?
Embodiment 13 69? Perpendicular type pulverizer 3.1? 70? 0.61?
Embodiment 14 70? タ one ボ カ ッ タ one 3? 71? 1.3?
Embodiment 15 71? タ one ボ グ ラ ィ Application ダ one 1? 72? 0.82?
Embodiment 15 71? タ one ボ グ ラ ィ Application ダ one 0.7? 73? 0.58?
Embodiment 17 70? ロ one ト Block レ ッ Network ス 2? 72? 1?
Embodiment 18 70? ロ one ト Block レ ッ Network ス 5? 71? 2?
Embodiment 18 71? ドラィマィスタ? -? 94? 0.4?
Embodiment 19 70? FDS? 1? 78? 0.65?
Embodiment 20 70? カ ッ タ one ミ Le 8? 72? 3?
Embodiment 20 72? メッシュミル? 2? 75? 0.6?
Embodiment 21 60? Perpendicular type pulverizer 3? 61? 1.6?
Comparative example 3
After (11) 1 pieces of the aqueous polymers of many gauffers form that embodiment 11 is obtained roughly are cut to 4 with annular saw, drop into the ミ that ダ ィ ス the is arranged one ト チ ョ パ one (flat congratulate make made) of aperture 8mm, it is excessive to load, and stops at once, is not pulverized.
Comparative example 4
After (11) 1 pieces of the aqueous polymers of many gauffers form that embodiment 11 is obtained roughly are cut to 4 with annular saw, drop into the サ Application プ Le ミ Le (KIIW-1 type, only パ ゥ ダ Le (strain) system) of net footpath 3mm, it is excessive to load, and stops at once, is not pulverized.
Comparative example 5
The aqueous polymers of many gauffers form that embodiment 11 is obtained drops into the σ type for (11) 1 pieces wing kneader) internal volume 2.5L, Xiao Chi ironworker's (strain) system), be stirred, but do not pulverized.
Comparative example 6
(11) 1 pieces of the aqueous polymers of many gauffers form that embodiment 11 is obtained drop into special opening in the device of flat 11-188727 Fig. 4 after roughly being cut to 4 with annular saw, are involved in the axle, but are not pulverized.
Comparative example 7
Dissolving polyethyleneglycol diacrylate (number average degree of polymerization of oxyethane=8) 9.25g makes reaction solution in the sodium acrylate aqueous solution 5500g of 65 moles of % of neutralization ratio (monomer concentration 30 weight %).Then, this reaction solution was outgased 30 minutes under nitrogen atmosphere.To have the formation reactor that closes the lid on the two wrist type kneaders of stainless steel with well of internal volume 10L of 2 σ type blades, above-mentioned reaction solution will be supplied to this reactor, reaction solution will be carried out nitrogen replacement to system in 30 ℃ of insulations.Then, in stirring reaction liquid, add 2, two (2-amidine propane) the dihydrochloride 1.91g of 2 '-azo, Sodium Persulfate 0.96g and L-xitix 0.10g began polymerization after 1 minute.Carry out polymerization at 30 ℃ to 80 ℃, polymerization begins to take out aqueous polymers after back 60 minutes.With the sectionalization of gained aqueous polymers to the about 5mm of diameter.The aqueous polymers of this sectionalization is launched on 50 purpose wire nettings, 150 ℃ of following warm air dryings 90 minutes.Then, dry thing is pulverized with vibrating mill, further used 20 purpose wire netting classifications, obtain the comparison basis polymkeric substance (7) of the unsetting broken shape of weight average particle diameter 300 μ m.With (7) 100 parts in gained comparison basis polymkeric substance, and form liquid and mix by 0.005 part of Versenex 80,1 part of propylene glycol, 0.05 part of ethylene glycol diglycidylether, 3 parts in water, 1 part of surface crosslinking agent that forms of Virahol.Said mixture 210 ℃ of heat treated 45 minutes, is obtained comparison surface cross-linking of water-absorbing resin (7).
Comparative example 8
With 67.0 parts of the sodium acrylate aqueous solution of 37 weight %, 10.2 parts in vinylformic acid, 0.155 part of polyethyleneglycol diacrylate (number average degree of polymerization of oxyethane=8) and 22.0 parts of mixing of water, modulation monomer solution.Be blown into nitrogen in jar in the above-mentioned aqueous solution, making the soluble oxygen content in the monomer solution is below the 0.1ppm.Then, under nitrogen atmosphere, the temperature of the above-mentioned aqueous solution is adjusted to 18 ℃, under agitation be added dropwise to 0.16 part of 5 weight % sodium persulfate aqueous solution successively, 2 of 5 weight %, 0.16 part of two (2-amidine propane) dihydrochloride aqueous solution of 2 '-azo, 0.17 part of the aqueous hydrogen peroxide solution of 0.15 part of the L-aqueous ascorbic acid of 0.5 weight % and 0.35 weight %.After being added dropwise to hydrogen peroxide, get started polymerization, after 10 minutes, the temperature of monomer solution reaches 85 ℃ of peak temperatures.Continuation is soaked jar in 80 ℃ hot water bath, slaking 5 minutes.The transparent aqueous polymers of gained is pulverized with ミ one ト チ ョ ッ パ one, the aqueous polymers of this sectionalization is launched on 50 purpose wire nettings, 160 ℃ of warm air dryings 65 minutes.Then, dry thing is pulverized with pulverizer, further will be sieved the material classification that remains on the 106 μ m sieves, obtain the comparison basis polymkeric substance (8) of the unsetting broken shape of weight average particle diameter 320 μ m by 850 μ m.With (8) 100 parts in gained comparison basis polymkeric substance, and by 1 part of propylene glycol, 1, the surface crosslinking agent of 0.5 part of 4-butyleneglycol, 3 parts in water, 1 part of formation of Virahol is formed liquid and is mixed.Said mixture 210 ℃ of heat treated 40 minutes, is obtained comparison surface cross-linking of water-absorbing resin (8).
In addition, the surface-crosslinked absorbent resin (2) of embodiment 2,3,5,6, (3), (5), (6), the comparison surface cross-linking of water-absorbing resin (1) of comparative example 1,7,8, (7), (8), GV, the AAP of the absorbent resin of comparison basis polymkeric substance (1), (7), (8) and other corporate systems of comparative example 1,7,8, the comparative result that can dissolve survival rate, GV * can dissolve survival rate are as shown in table 5.
[table 5]
? Synthesis example or manufacturers's title GV(g/g)? AAP(g/g)? Can dissolve survival rate (%) GVx can dissolve survival rate ((g/g) %)
Surface-crosslinked absorbent resin (2) Embodiment 2 42? 36? 25? 1050?
Surface-crosslinked absorbent resin (3) Embodiment 3 34? 35? 21? 714?
Surface-crosslinked absorbent resin (5) Embodiment 5 25? 26? 18? 450?
Surface-crosslinked absorbent resin (6) Embodiment 6 23? 24? 25? 575?
Comparison surface cross-linking of water-absorbing resin (1) Comparative example 1 28? 26? 73? 2044?
Comparison basis polymkeric substance (7) Comparative example 7 48? -? 41? 1968?
Comparison surface cross-linking of water-absorbing resin (7) Comparative example 7 33? 30? 49? 1617?
Comparison basis polymkeric substance (8) Comparative example 8 39? -? 60? 2340?
Comparison surface cross-linking of water-absorbing resin (8) Comparative example 8 28? 28? 65? 1820?
SXM-75? Stockhausen? 32? 29? 43? 1376?
SXM-77? Stockhausen? 31? 25? 62? 1922?
ASAP2300? BASF? 31? 26? 68? 2108?
ASAP2300? BASF? 24? 24? 84? 2016?
Drytech? Dow? 30? 31? 60? 1800?
Use rational engineering, provide to absorb the few base polymer of the high solvable component of multiplying power under the no loading and carried out the high absorbent resin of surface-crosslinked absorbent rate under pressure.
Owing to reach above-mentioned effect, the resin that obtains according to the present invention, the purposes that contacts with human body at sanitary product (paper nappy of child and big human, sanitary napkin, adult-incontinence articles etc.) etc.; The water-holding agent of plant or soil; Electric wire or optical cable water-proof material; Civil construction is with being useful in water-proof material etc.

Claims (19)

1. the preparation method of an absorbent resin, this method are to be the method that 70 moles of monomer components more than the % prepare absorbent resin by polymeric acrylic acid in the aqueous solution and/or its salt with respect to the monomer component total content, it is characterized in that,
The concentration of monomer component is 30～70 weight % in the aqueous solution,
Polymerization initiation temperature is more than 50 ℃ below 105 ℃,
Top temperature in the polymerization is more than 105 ℃ below 140 ℃,
Polymerization heats up than being below 0.30,
The difference Δ T of the top temperature that reaches in polymerization initiation temperature and the polymerization is below 70 ℃,
Polymerization time was less than 3 minutes, and polymerization time is meant puts into aggregation container with monomer solution, began time till the top temperature from possessing the polymerization condition of beginning,
The solid formation branch concentration of the aqueous polymers that polymerization generates is 55～82 weight %.
2. the preparation method of absorbent resin as claimed in claim 1 is characterized in that, is used in combination photolysis type initiator and thermolysis type initiator as polymerization starter.
3. the preparation method of absorbent resin as claimed in claim 1 is characterized in that, is used in combination photolysis type initiator and thermolysis type initiator as polymerization starter,
The concentration of monomer component is 45～70 weight % in the aqueous solution.
4. the preparation method of absorbent resin as claimed in claim 1 is characterized in that, acrylic acid neutralization ratio is 50 moles more than the %.
5. the preparation method of absorbent resin as claimed in claim 1 is characterized in that, the concentration of monomer component is 45～70 weight % in the aqueous solution.
6. the preparation method of absorbent resin as claimed in claim 1 is characterized in that, the concentration of monomer component is 45～70 weight % in the aqueous solution, and acrylic acid neutralization ratio is 50 moles more than the %.
7. the preparation method of absorbent resin as claimed in claim 1 is characterized in that, carries out polymerization when extending.
8. the preparation method of absorbent resin as claimed in claim 1 is characterized in that, the aqueous polymers that the solid formation branch concentration that polymerization is generated is 55～82 weight % further is crushed to the weighted average particle directly for below the 100mm.
9. the preparation method of absorbent resin as claimed in claim 1 is characterized in that, the aqueous polymers that the solid formation branch concentration that polymerization is generated is 55～82 weight % further uses the pulverizer that has filtering net to pulverize.
10. the preparation method of absorbent resin as claimed in claim 1 is characterized in that, the aqueous polymers that the solid formation branch concentration that polymerization is generated is 55～82 weight % further uses the pulverizer pulverizing to reach and forms branch concentration rate of rise in the pulverizing admittedly more than 2.
11. the preparation method of absorbent resin as claimed in claim 1 is characterized in that, the aqueous polymers that the solid formation branch concentration that polymerization is generated is 55～82 weight % further uses pulverizer to pulverize in ventilation.
12. the preparation method of absorbent resin as claimed in claim 1, it is characterized in that, the aqueous polymers pulverizing that polymerization is generated obtains, and is that 55～82 weight %, remaining amount of monomer 1000ppm are following, 3mm following particle shape aqueous polymers in weighted average particle footpath carries out surface-crosslinked Gu form branch concentration.
13. the preparation method of absorbent resin as claimed in claim 1 is characterized in that comprising,
(1) the solid formation of preparation branch concentration is the polymerization engineering of the aqueous polymers of 55～82 weight %,
(2) will form branch concentration admittedly is that the aqueous polymers of 55～82 weight % is crushed to the following comminution engineering of weighted average particle footpath 10mm,
(3) the solid formation branch concentration of the aqueous polymers after will pulverizing improves the drying process more than 3%.
14. the preparation method of absorbent resin as claimed in claim 1 is characterized in that, will not carry out deoxidation in advance and in being fed to and the operation of operation as the vinylformic acid of monomer solution raw material, alkali aqueous solution, water etc.; Utilize the solution heat of neutralization heat and/or propylene bronsted lowry acids and bases bronsted lowry, monomer solution is heated up, the dissolved oxygen in the volatilization monomer solution carries out the neutral operation; With the operation that monomer solution is fed to polymerization process.
15. the preparation method of absorbent resin as claimed in claim 14 is characterized in that, carries out polymerization process in the open system of not using rare gas element.
16. the preparation method of absorbent resin as claimed in claim 14 is characterized in that, utilize the solution heat of neutralization heat and/or propylene bronsted lowry acids and bases bronsted lowry that monomer solution is heated up after, amount of dissolved oxygen is below 4ppm in the monomer solution.
17. the preparation method of absorbent resin as claimed in claim 14 is characterized in that, with vinylformic acid and the neutralization of alkali on-line mixing.
18. the preparation method of absorbent resin as claimed in claim 14 is characterized in that, the temperature of monomer solution is warming up to more than 80 ℃.
19. the preparation method of absorbent resin as claimed in claim 14 is characterized in that, acrylic acid neutralization ratio of the monomer solution after the neutralization is 80 moles of % of 50 moles of above less thaies of %.
CN2006101003888A 2000-08-03 2001-08-03 Process for producing water-absorbent resin, and uses thereof Expired - Lifetime CN1908020B (en)

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