CN101143229A - Water-absorbing agent and body liquid absorbing production - Google Patents

Water-absorbing agent and body liquid absorbing production Download PDF

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Publication number
CN101143229A
CN101143229A CNA2007101674092A CN200710167409A CN101143229A CN 101143229 A CN101143229 A CN 101143229A CN A2007101674092 A CNA2007101674092 A CN A2007101674092A CN 200710167409 A CN200710167409 A CN 200710167409A CN 101143229 A CN101143229 A CN 101143229A
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water
absorbing agent
weight
water absorbing
adsorption capacity
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和田克之
植田裕子
高桥直子
长砂欣也
三宅浩司
藤田康弘
初田卓己
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Nippon Shokubai Co Ltd
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Abstract

The present invention provides: a water-absorbing agent which has excellent urine resistance; a water-absorbing agent which has not only excellent urine resistance, but also excellent absorption properties that are stable to any composition of urine and show little change with time; and uses for these water-absorbing agents. The present invention water-absorbing agent exhibits a specific or larger value of absorption capacity under a load in a process in which the absorption capacity under a load is measured in a new manner using a specific liquid to be absorbed, and the present invention provides an absorbent matter which displays a specific or larger value of new absorption index as is, for example, led from the absorption capacity under a load or from the resin concentration using the above water-absorbing agent.

Description

Water absorbing agent and body fluid absorbent articles
The application is that the application number submitted on March 3rd, 1999 is 99102593.8, denomination of invention is divided an application for the application of " water absorbing agent and manufacture method thereof and application ".
Background of invention
A. technical field
The present invention relates to water absorbing agent and manufacture method thereof and application, more specifically the present invention relates to a kind of water absorbing agent with good urine patience, particularly no matter for which kind of liquid to be adsorbed, urine for example, the water absorbing agent that all has good absorption property, the invention still further relates to the method for manufacturing water absorbing agent and the application of this water absorbing agent, promptly be used as adsorbing material and absorbent articles, the invention still further relates to a kind of measuring method of absorption property, utilize this method, can be easily and prediction its absorption behavior when actual use water absorbing agent and adsorbing material and goods exactly.
B. background technology
In recent years, water-absorbing resin (water absorbing agent) was used as the composition material of hygienic articles widely, for example was used to make diaper, sanitary towel and the so-called incontinence of water-absorbing resin absorption such as body fluid such as urine or menstruation blood with filling up.
The example of known above-mentioned water-absorbing resin is as follows: the neutral polyacrylic cross linked polymer of part; The hydrolyzate of starch-acrylic acid-grafted polymer; The saponification resultant of vinylacetate and acrylate copolymer; The hydrolyzate of acrylonitrile copolymer or acrylamide copolymer and their cross linked polymer; Cross linked polymer with cationic monomer.
It is said that above-mentioned water-absorbing resin should have for example following performance: good water absorption and absorption speed, gel strength, with liquid, aqueous for example when body fluid contacts from comprise liquid, aqueous primer the absorption affinity of adsorbed water.Yet existing problems also wherein, promptly the relation between these performances does not show positive dependency: for example when adsorption capacity increases, some other performance, for example permeability for liquids, gel strength and adsorption rate are with regard to decline.
Make it that good balanced method be arranged as for the water absorbing properties that improves this water-absorbing resin, known a kind of like this technology is wherein carried out the nearly surface portion of water-absorbing resin crosslinkedly, and people it was suggested multiple these class methods.
For example, in multiple known method, following substances is used as cross-linking agent: polyhydric alcohol (JP-A-58-180233 and JP-A-61-016903); Multi-shrinking glyceryl compound, many aziridine cpds, polyamine compounds or polyisocyanate compound (JP-A-59-189103); Polyvalent metal (JP-A-51-136588, JP-A-61-257235 and JP-A-62-007745); Mono-epoxy compounds (JP-A-61-098121); The epoxide of associating use and hydroxy compounds (JP-A-02-132103); Alkylene carbonates (DE4020780).
Yet this also has problems, and can improve balance between the water absorbing properties by above-mentioned surface treatment that is:, but when water-absorbing resin is used as the adsorbing material of diaper, water-absorbing resin is damaged as time passes, and permeability for liquids or gel strength descend, and urine will be leaked from diaper like this.The destruction of described water-absorbing resin begins to take place from the surface of water-absorbing resin, and soluble composition flows out permeability for liquids or gel strength decline.It is caused by little metal ion that contains in the urine and L-ascorbic acid that the destruction of this water-absorbing resin is considered to.
Therefore in addition, water-absorbing resin is pulverous, may contain 100 microns or littler fine powder, knownly carries out the purpose that pelletize can reach the permeability for liquids of improving operating characteristics or diaper by adding water.Pelletize can stop powdered or improve flowability in the aqueous vapor adsorption process.
Yet this also has problems, and, makes it granulation meeting deface cross-linked layer by add water in surface-crosslinked water-absorbing resin that is.Particularly for the desired water-absorbing resin that high adsorption capacity arranged under load in recent years, removing of solubilized composition is to assign to stop by crosslinked nearly surface element with water-absorbing resin of high-adsorption-capacity, like this absorption during urine when being subjected to the destruction of the material such as the L-ascorbic acid for surface-crosslinked layer, removing of alkaline soluble materials can't be suppressed.Therefore still there is defective in this, that is, when water-absorbing resin was used for diaper, permeability for liquids or gel strength were damaged, and urine will leak out from diaper.
On the other hand, for the purposes of water-absorbing resin, advised the adsorbing material or the absorbent articles of multiple use water-absorbing resin, wherein when water-absorbing resin was used as such as hygienic articles such as diaper or sanitary towels, it had multiple above-mentioned performance and shows good performance (water absorbing properties).
For example, following absorbent material is known: a kind of water-absorbing resin (U.S.P.4,654,039) with combination of specific gel capacity, the coefficient of rigidity and extractable polymer content; A kind of diaper and sanitary towel (JP-A-60-185550, JP-A-60-185551 and JP-A-60-185804) that has the water-absorbing resin of specific water absorption or absorption speed and gel strength and utilize this water-absorbing resin; Use has the diaper (JP-A-60-185805) of the water-absorbing resin of specific water absorption or absorption speed and gel stability; Use has the absorbent articles (JP-A-63-021902) of the water-absorbing resin of specified water absorption, absorption affinity and water-soluble substance content; Comprise have specific water absorption, the hydroscopic sanitary towel (JP-A-63-099861) of the water-absorbing resin of the water absorption under load condition and gel breakdown strength; The diaper (JP-A-02-034167) that comprises water-absorbing resin with the specific water absorption under load condition and absorption speed; The water absorbing agent (EP 339,461) that comprises water-absorbing resin with the specific water absorption under load condition and particle diameter; Comprise specific or a large amount of water absorbing agents (EP 443,627) with water-absorbing resin of the water absorption under load condition in specific absorption speed and short time; The composite absorbent material (EP532,002) that comprises specific or a large amount of water-absorbing resins with the specific distortion capacity under load condition and adsorption exponent; But has the absorbent articles (EP 615,735) of the resin of specific pressure adsorption exponent and 16 hours extraction quantities with use.
In recent years, for example the such absorbent articles of diaper was more and more thinner, and was progressively increasing as the amount of the water-absorbing resin of the adsorption layer of absorbent articles.That is to say, for above-mentioned adsorption layer, the weight rate of the total amount of its water-absorbing resin and water-absorbing resin and fiber base material (after this this ratio is called resin concentration) be 0.3 or more, particularly 0.5 or more, just becoming main trend.Yet more and more be apparent that, when the above-mentioned known resin with various particular characteristics is used for these absorbent articles with high resin concentration, still have problems.That is to say,, can improve the water absorbing properties of absorbent articles by making up above-mentioned various performance, but this wherein still has problems obviously, that is, and and according to the composition for the treatment of adsorptive liquid, the water absorbing properties of resin can not fully show, particularly when the resin concentration in the absorbent articles is higher.The problem that it is believed that existence is, when absorbent articles for example is diaper, the composition of urine is along with multiple factor, for example age of user, the F﹠B of being eaten, the medicine taken and change, and therefore will there be very big difference in the absorption behavior of water-absorbing resin with Expected Results.
Summary of the invention
A. goal of the invention
Therefore one object of the present invention is to provide: a kind of water absorbing agent, and this water absorbing agent is when the absorption urine, and the destruction that As time goes on is subjected to is very little, therefore has good urine patience; A kind of water absorbing agent, this water absorbing agent not only has good urine patience, and also having all has passing stable and in time to change very little absorption property to any urine composition, so this water absorbing agent is particularly suitable for being used in the absorbent articles with high resin concentration; And the manufacture method of these water absorbing agents.
In addition, another object of the present invention is, which type of absorption property clarification water-absorbing resin when the resin ratio is a particular value needs, and provide a kind of absorbent articles that uses best water-absorbing resin to each water-absorbing resin ratio, and provide a kind of adsorbing material and absorbent articles, it always has stable high adsorption capacity, particularly still has stable high adsorption capacity under the user mode when very being similar to actual use when taking place to leak.
In addition, a further object of the present invention is, a kind of absorption property measuring method is provided, by this method, can be easily and prediction its absorption behavior when actual use water absorbing agent and adsorbing material and goods exactly, and this measuring method is useful especially for water absorbing agent, adsorbing material or the absorbent articles that production has good absorption property.
B. disclosure of an invention
The inventor is devoted to realize above-mentioned purpose.The result, the evaluation methodology that inventor's exploitation makes new advances, described evaluation methodology is used for estimating: (1) uses a kind of specific destruction adsorption capacity under load condition when treating adsorptive liquid, (2) use a kind of specific adsorptive liquid for the treatment of to carry out the specific program destruction adsorption capacity under load condition afterwards, (3) the destruction adsorption exponent under load condition, and find, utilization has the specific or big adsorption capacity under load condition or destroys the water absorbing agent of adsorption exponent value in these evaluation methodologys, can solve problem mentioned above, thereby finish the present invention.Specific program is not passed through in providing of above-mentioned parameter (1), so the static state that after this is called under load condition is destroyed adsorption capacity, and the size of considering load comprises four-stage (1), (2), (3) and (4), and wherein stage (1) and (4) are particular importances.Specific program has been passed through in providing of parameter (2), so after this be called the dynamic destruction adsorption capacity under load condition.
The inventor has found that also a kind of acquisition has the method for the water absorbing agent of above-mentioned specific adsorption capacity or index (following these be commonly referred to as parameter), wherein preferably adds ion sealer or the chelating agen that comprises the aminopolycanboxylic acid by a kind of specific method in water-absorbing resin.
In addition, the inventor has been devoted to study the relation between the physical property of resin ratio in the adsorbing material and adsorbent.The inventor finds as a result: continue under the user mode when being in close proximity to actual use until the adsorbance that leakage takes place, depend on the particular kind of relationship of deriving in the resin ratio performance from water absorbing agent (for example adsorption capacity under no-load condition and above-mentioned new specific adsorption capacity or index under load condition) and the adsorbing material, and find: if select water absorbing agent and resin ratio, the value of above-mentioned relation formula is increased, then can increase, thereby finish the present invention in the adsorbance that is in close proximity to adsorbing material under the user mode of actual user mode or absorbent articles.
According to water absorbing agent of the present invention can be any in following 1～3.
1. have water absorption capacity 30 (g/g) under non-loaded or higher, and the static state under load to destroy adsorption capacity (1) be 20 (g/g) or higher water absorbing agent.
2. have water absorption capacity 30 (g/g) under non-loaded or higher, and the dynamic destruction adsorption capacity under load is 20 (g/g) or higher water absorbing agent.
3. have water absorption capacity 30 (g/g) under non-loaded or higher, and the static state under load to destroy adsorption capacity (4) be 23 (g/g) or higher water absorbing agent.
Comprise the water absorbing agent and the fiber base material of the invention described above according to adsorbing material of the present invention, wherein the weight ratio of water absorbing agent and water absorbing agent and fiber base material gross weight is 0.4 or higher.
Comprise according to absorbent articles of the present invention:
The water accepting layer that comprises the invention described above adsorbing material;
The surficial sheets of fluid permeable; With
The impermeable bottom sheet of liquid.
Absorption property measuring method of the present invention is characterised in that the liquid that contains reducible material is used in measurement and is selected from the measuring method of at least a absorption property in the following performance: the absorption property of water absorbing agent under load as being adsorbed liquid; The weight ratio of water absorbing agent and water absorbing agent and fiber base material gross weight is 0.4 or the absorption property of higher adsorbing material; The absorption property that comprises the absorbent articles of above-mentioned adsorbing material.
According to the manufacture method of water absorbing agent of the present invention, comprise the ion sealer and can carry out blended step with the surface crosslinking agent of carboxyl reaction and water-absorbing resin with carboxyl.
The another kind of method of making water absorbing agent of the present invention comprises the following steps:
The nearly surface portion of water-absorbing resin is carried out crosslinked, this water-absorbing resin carries out polymerization by the monomer component that comprises unsaturated carboxylic acid and obtains in the presence of internal crosslinker; With
In the surface-crosslinked water-absorbing resin that obtains, add entry and ion sealer, like this with the water-absorbing resin pelletize.
According to the present invention, the preparation method of another kind of water absorbing agent comprises that adding at least a chemical compound and the maleic acid that is selected from general formula (1) and (2) in water-absorbing resin is the step of the chelating agen of hydrophilic polymer (comprising salt) (3),
Its formula of (1) is:
Figure A20071016740900111
Wherein: n, X 1And R 1～R 3Representative is column of figure and structure down:
n＝0,1
X 1＝COOM 1(M 1＝H，Na，K，NH 4)
R 1＝H，OH，Me
R 2＝H，-CH 2COOM 2，-CH 2CH 2COOM 2(M 2＝H，Na，K，NH 4)
Figure A20071016740900112
(M 3＝H，Na，K，NH 4)(R 4＝H，OH，Me)
And general formula wherein (2) is:
Figure A20071016740900113
Wherein: m, X 2And R 5～R 8Representative is column of figure and structure down:
m＝0,1
X 2＝COOM 4(M 4＝H，Na，K，NH 4)
R 5＝H，OH，Me
R 6＝H，-CH 2COOM 5，-CH 2CH 2COOM 5 (M 5＝H，Na，K，NH 4)
R 7＝H，-CH 2COOM 6，-CH 2CH 2COOM 6 (M 6＝H，Na，K，NH 4)
(M 7＝H，Na，K，NH 4)(R 9＝H，OH，Me).
The above and other objects and advantages of the present invention will become clearer from following detailed description.
Brief Description Of Drawings
Fig. 1 represent a kind of under load the measuring device of water absorption capacity.
Detailed Description Of The Invention
From then on down will explain in detail the present invention.
＜water absorbing agent 〉
Water absorbing agent of the present invention has specific or larger adsorption capacity value under non-loaded, and have the specific or larger value that relates to following new capability: the static state under load is destroyed adsorption capacity, dynamic failure adsorption capacity under load, and the destruction adsorption exponent under load.
In the present invention, adsorption capacity under non-loaded is an arithmetic value, calculate as follows: 0.2 gram water absorbing agent evenly is placed on (60mm * 60mm), then immerse the sodium-chloride water solution (physiological sodium chloride solution) of 0.9wt% in the bag that a nonwoven makes; After 60 minutes, pull out sack, then under 250G, dry 3 minutes with centrifuge, then measure the weight W1 (g) of sack; On the other hand, carry out same program without water absorbing agent, measure weight W0 (g); Like this, by above-mentioned weight W1And W0Calculate according to the following equation adsorption capacity with the weight of water absorbing agent:
Adsorption capacity (g/g)={ (weight W1-weight W0)/(water absorbing agent weight) }-1.
In the present invention, it is the adsorption capacity of water absorbing agent (resin) through measuring under load after the following processing that static state under load is destroyed adsorption capacity: the physiological sodium chloride solution with the L-AA that contains predetermined concentration makes water absorbing agent swell to 15 times as liquid upon adsorption, then with this swelling water absorbing agent leave standstill certain hour. Should the static state destruction adsorption capacity under load be a new assessment item of water absorbing agent.
Common water-absorbing resin (water absorbing agent) for example following absorption property is known: adsorption capacity, the adsorption capacity under load, permeability for liquids, absorption affinity, and adsorption rate. Yet measuring all is to carry out with the liquid near the electrolyte concentration of urine within the relatively short time usually. But in many cases, the time used of diaper reaches 6 hours or longer. Therefore can in above-mentioned common assessment item, provide the water-absorbing resin of good evaluation result might not also show good performance in actual applications. In addition, the passing that the compound that comprises in the urine can be in time and change the performance of (destruction) resin, and also the existence of these compounds also greatly affects water-absorbing resin absorption behavior in actual use.
The inventor is devoted to develop a kind of evaluation method that can correctly estimate water-absorbing resin adsorption capacity in actual use. The inventor finds as a result, measure its adsorption capacity under load after making water-absorbing resin in the physiological sodium chloride solution as the L-AA that contains predetermined concentration of liquid upon adsorption, leave standstill the relatively long time, just can be easily and predict exactly water-absorbing resin absorption behavior in actual use.
In known commonsense method, with L-AA or its salt dissolving water-absorbing resin, perhaps measure by this way the amount of the soluble component of dissolving (JP-A-05-247221 for example, JP-A-07-059813, JP-A-08-337726, JP-A-10-067805). Yet, in these technology, water-absorbing resin is dissolved under saturated swelling condition, and how the ability of not considering its adsorptive liquid when resin uses changes, and this adsorption capacity inward nature of water-absorbing resin just, it is a new assessment item that yet the static state under load among the present invention is destroyed adsorption capacity, and it can be judged after the water-absorbing resin absorption urine until resin when again adsorbing urine, and how its inherent adsorption capacity that still keeps changes because of the effect of urine.
In the present invention, the static state under load is destroyed the adsorption capacity that adsorption capacity (1) is the water absorbing agent that follows these steps to record:
Physiological sodium chloride solution with the L-AA that contains 0.005% (weight) concentration makes water absorbing agent swell to 15 (g/g);
This water absorbing agent was stayed under such solvent swelling state 6 hours;
Water absorbing agent in swelling adds 50g/cm2Load, under this state, make the water absorbing agent of swelling adsorb again physiological sodium chloride solution 1 hour; With
The weight of the swell gel that measures.
Water absorbing agent of the present invention is characterised in that the adsorption capacity under non-loaded is 30 (g/g) or higher, and the above-mentioned static state destruction adsorption capacity (1) under load is 20 (g/g) or higher. If be lower than 30 (g/g) in non-loaded lower adsorption capacity, then adsorption capacity is not enough, and the situations such as leakage occur easily, particularly when water absorbing agent is used in the absorbent articles with high resin concentration. Adsorption capacity under non-loaded preferably is at least 33 (g/g), more preferably is at least 35 (g/g). In addition, if destroying adsorption capacity (1), the static state under load condition is lower than 20 (g/g), then similarly, the adsorption capacity of absorbent articles is not enough, the situations such as leakage are easy to occur, or the factor that changes and so on owing to the composition of for example liquid upon adsorption changes a lot absorption behavior, therefore can't obtain stable absorption property. Static state under load condition is destroyed adsorption capacity (1) and is preferably 23 (g/g) or higher.
In the present invention, the static state under load is destroyed the adsorption capacity that adsorption capacity (2) is the water absorbing agent that follows these steps to record:
Physiological sodium chloride solution with the L-AA that contains 0.005% (weight) concentration makes water absorbing agent swell to 15 (g/g);
This water absorbing agent was stayed under such solvent swelling state 2 hours;
Water absorbing agent in swelling adds 50g/cm2Load, under this state, make the water absorbing agent of swelling adsorb again physiological sodium chloride solution 1 hour; With
The weight of the swell gel that measures.
Water absorbing agent of the present invention is characterised in that the adsorption capacity under non-loaded is 30 (g/g) or higher, and the above-mentioned static state destruction adsorption capacity (2) under load is 23 (g/g) or higher. If be lower than 30 (g/g) in non-loaded lower adsorption capacity, then adsorption capacity is not enough, and the situations such as leakage occur easily, particularly when water absorbing agent is used in the absorbent articles with high resin concentration. Adsorption capacity under non-loaded preferably is at least 33 (g/g), more preferably is at least 35 (g/g). In addition, if destroying adsorption capacity (2), the static state under load condition is lower than 23 (g/g), then similarly, the adsorption capacity of absorbent articles is not enough, the situations such as leakage are easy to occur, or the factor that changes and so on owing to the composition of for example liquid upon adsorption changes a lot absorption behavior, therefore can't obtain stable absorption property. Static state under load condition is destroyed adsorption capacity (2) and is preferably 25 (g/g) or higher.
In the present invention, the static state under load is destroyed the adsorption capacity that adsorption capacity (3) is the water absorbing agent that follows these steps to record:
Physiological sodium chloride solution with the L-AA that contains 0.05% (weight) concentration makes water absorbing agent swell to 15 (g/g);
This water absorbing agent was stayed under such solvent swelling state 2 hours;
Water absorbing agent in swelling adds 50g/cm2Load, under this state, make the water absorbing agent of swelling adsorb again physiological sodium chloride solution 1 hour; With
The weight of the swell gel that measures.
Water absorbing agent of the present invention is characterised in that the adsorption capacity under non-loaded is 30 (g/g) or higher, and the above-mentioned static state destruction adsorption capacity (3) under load is 20 (g/g) or higher. If be lower than 30 (g/g) in non-loaded lower adsorption capacity, then adsorption capacity is not enough, and the situations such as leakage occur easily, particularly when water absorbing agent is used in the absorbent articles with high resin concentration. Adsorption capacity under non-loaded preferably is at least 33 (g/g), more preferably is at least 35 (g/g). In addition, if destroying adsorption capacity (3), the static state under load condition is lower than 20 (g/g), then similarly, the adsorption capacity of absorbent articles is not enough, the situations such as leakage are easy to occur, or the factor that changes and so on owing to the composition of for example liquid upon adsorption changes a lot absorption behavior, therefore can't obtain stable absorption property. Static state under load condition is destroyed adsorption capacity (3) and is preferably 23 (g/g) or higher.
In the present invention, the static state under load is destroyed the adsorption capacity that adsorption capacity (4) is the water absorbing agent that follows these steps to record:
Physiological sodium chloride solution with the L-AA that contains 0.05% (weight) concentration makes water absorbing agent swell to 15 (g/g);
This water absorbing agent was stayed under such solvent swelling state 6 hours;
Water absorbing agent in swelling adds 20g/cm2Load, under this state, make the water absorbing agent of swelling adsorb again physiological sodium chloride solution 1 hour; With
The weight of the swell gel that measures.
Water absorbing agent of the present invention is characterised in that the adsorption capacity under non-loaded is 30 (g/g) or higher, and the above-mentioned static state destruction adsorption capacity (4) under load is 30 (g/g) or higher. If be lower than 30 (g/g) in non-loaded lower adsorption capacity, then adsorption capacity is not enough, and the situations such as leakage occur easily, particularly when water absorbing agent is used in the absorbent articles with high resin concentration. Adsorption capacity under non-loaded preferably is at least 33 (g/g), more preferably is at least 35 (g/g). In addition, if destroying adsorption capacity (4), the static state under load condition is lower than 30 (g/g), then similarly, the adsorption capacity of absorbent articles is not enough, the situations such as leakage are easy to occur, or the factor that changes and so on owing to the composition of for example liquid upon adsorption changes a lot absorption behavior, therefore can't obtain stable absorption property. Static state under load condition is destroyed adsorption capacity (4) and preferably is at least 32 (g/g), more preferably is at least 34 (g/g).
The invention provides a kind of new water absorbing agent, it is specific value or larger value that it above-mentioned destroyed adsorption capacity (1), (2), (3), (4) in the adsorption capacity under the no-load condition and the static state under load condition. This water absorbing agent is suitable for having the paper nappy of higher resin concentration and lower fiber base material concentration, higher resin concentration and lower fiber base material concentration be owing in recent years paper nappy increasingly attenuation cause that this water absorbing agent can also reduce leakage phenomenon in actual use.
The inventor finds that the value that the static state under load condition is destroyed adsorption capacity (1) or (4) is particular importance. Therefore the invention provides a kind of new water absorbing agent, it is specific value or larger value that it above-mentioned destroyed adsorption capacity (1) or (4) in the adsorption capacity under the no-load condition and the static state under load condition, and the absorbent articles (for example paper nappy) of use water absorbing agent of the present invention can reduce leakage phenomenon in actual use.
The measured value that the static state of water absorbing agent under load condition is destroyed adsorption capacity (1) is very important for the paper nappy with higher resin concentration and lower fiber base material concentration, and higher resin concentration and lower fiber base material concentration be owing in recent years paper nappy increasingly attenuate cause.
In the present invention, dynamic failure adsorption capacity under load is the adsorption capacity of water absorbing agent (resin) through measuring under load after the following processing: use the physiological sodium chloride solution of the L-AA that contains predetermined concentration as liquid upon adsorption, make water absorbing agent swell to 15 times, then with this swelling the static placement certain hour of water absorbing agent, then copy the motion in the actual use to carry out dynamic failure. Dynamic failure adsorption capacity under load is a new assessment item of water absorbing agent.
Common water-absorbing resin (water absorbing agent) for example following absorption property is known: adsorption capacity, the adsorption capacity under load, permeability for liquids, absorption affinity, and adsorption rate. In addition known a kind of method, wherein: make water-absorbing resin absorption physiological sodium chloride solution, and therefore form gel, shear the gel that obtains, then measure the again adsorption capacity (U.S.P.5,453,323) of gel. Yet the measurement of above-mentioned performance all is to carry out with the liquid near the electrolyte concentration of urine within the relatively short time usually. Therefore can in above-mentioned common assessment item, provide the water-absorbing resin of good evaluation result might not also show superior performance in actual applications. In addition, the compound that comprises in the urine can change the performance of (destruction) resin in time, and the existence of these compounds also greatly affects water-absorbing resin absorption behavior in actual use. And, because the user moves in actual the use, so dynamic force also can be exerted one's influence to resin.
The inventor is devoted to develop a kind of evaluation method that can correctly estimate water-absorbing resin adsorption capacity in actual use. The result, the inventor finds, water-absorbing resin is handled as follows its adsorption capacity under load of rear measurement, just can be easily and predict exactly water-absorbing resin absorption behavior in actual use: make water-absorbing resin in the physiological sodium chloride solution as the L-ascorbic acid that contains predetermined concentration of liquid upon adsorption, leave standstill the relatively long time, then resin is applied dynamic force.
In the known commonsense method, with L-AA or its salt dissolving water-absorbing resin, perhaps measure by this way the amount of the soluble component of dissolving (JP-A-05-247221 for example, JP-A-07-059813, JP-A-08-337726, JP-A-10-067805). Yet, in these technology, water-absorbing resin is dissolved under saturated swelling condition, and how the ability of not considering its adsorptive liquid when resin uses changes, this adsorption capacity is the inward nature of water-absorbing resin just, yet the dynamic failure adsorption capacity under load among the present invention is a new assessment item, it can be judged after the water-absorbing resin absorption urine until resin when again adsorbing urine, and how its inherent adsorption capacity that still keeps changes because of urine and the effect that is applied to the dynamic force on the resin.
In the present invention, the dynamic failure adsorption capacity under load is the adsorption capacity of the water absorbing agent that follows these steps to record:
Physiological sodium chloride solution with the L-AA that contains 0.005% (weight) concentration makes water absorbing agent swell to 15 (g/g);
This water absorbing agent was stayed under such solvent swelling state 4 hours;
Dynamically destroy swollen water absorbing agent;
On swollen water absorbing agent, add 50g/cm 2Load, under this state, make to be subjected to dynamic destructive water absorbing agent and to adsorb physiological sodium chloride solution again 1 hour; With
The weight of the swell gel that measures.
Water absorbing agent of the present invention is characterised in that the adsorption capacity under non-loaded is 30 (g/g) or higher, and the above-mentioned dynamic destruction adsorption capacity under load is 20 (g/g) or higher.As if being lower than 30 (g/g) in non-loaded adsorption capacity down, then absorbability is insufficient, and situations such as leakage take place easily, particularly when water absorbing agent is used in the absorbent articles with high resin concentration.Adsorption capacity under non-loaded preferably is at least 33 (g/g), more preferably is at least 35 (g/g).In addition, if the dynamic destruction adsorption capacity under load condition is lower than 20 (g/g), then similarly, the absorbability of absorbent articles is insufficient, situations such as leakage are easy to take place, or, therefore can't obtain stable absorption property owing to the composition of for example treating adsorptive liquid changes and the factor that puts on dynamic force on the resin and so on changes a lot absorption behavior.Dynamic destruction adsorption capacity under load condition is preferably 23 (g/g) or higher.
The invention provides a kind of new water absorbing agent, the above-mentioned of it is specific value or bigger value in adsorption capacity under the no-load condition and the dynamic destruction adsorption capacity under load condition.This water absorbing agent is suitable for having the diaper of higher resin concentration and lower fiber base material concentration, higher resin concentration and lower fiber base material concentration be since in recent years diaper day by day attenuation cause that this water absorbing agent can also reduce leakage phenomenon in actual use.
Among the present invention, be that above-mentioned static state under load condition is destroyed adsorption capacity (1)～(4) and the dynamic summation of destroying adsorption capacity at the destruction adsorption exponent under the load condition.Destruction adsorption exponent under load condition is the destructive assessment item of having considered under the actual user mode.Can think that the summation of the value that is obtained by above-mentioned evaluation item is big more, then water absorbing agent always has high more performance, even be subjected to the various destructions that produce as in actual use.
Water absorbing agent of the present invention is 30 (g/g) or higher in non-loaded adsorption capacity down, and its destruction adsorption exponent under load is 110 (g/g) or higher.As if being lower than 30 (g/g) in non-loaded adsorption capacity down, absorbability is insufficient, and situations such as leakage take place easily, particularly when water absorbing agent is used in the absorbent articles with high resin concentration.Adsorption capacity under non-loaded preferably is at least 33 (g/g), more preferably is at least 35 (g/g).In addition, when the destruction adsorption exponent under load condition is lower than 110 (g/g), similarly, the absorbability of absorbent articles is not enough, situations such as leakage are easy to take place, or, therefore can't obtain stable absorption property owing to absorption behavior being changed a lot such as the variation for the treatment of the adsorptive liquid composition and the factors such as dynamic force that are applied on the resin.Destruction adsorption exponent under load condition preferably is at least 120 (g/g), more preferably is at least 130 (g/g).
The present invention also provides a kind of new water absorbing agent, and the above-mentioned of it is specific value or bigger value in adsorption capacity under the no-load condition and the destruction adsorption exponent under load condition.This water absorbing agent is suitable for having the diaper of higher resin concentration and lower fiber base material concentration, higher resin concentration and lower fiber base material concentration be since in recent years diaper day by day attenuation cause that this water absorbing agent can also reduce leakage phenomenon in actual use.
As previously mentioned, the inventor is devoted to develop a kind of evaluation methodology that can correctly assess water-absorbing resin absorbability in actual use, therefore the inventor has found the above-mentioned static state destruction adsorption capacity under load condition, new capability at dynamic destruction adsorption capacity under the load condition and the destruction adsorption exponent under load condition, but the inventor also finds, by making resin swelling with physiological sodium chloride solution, make resin leave standstill the long period then, measure subsequently in the adsorption capacity under the load condition (i.e. approximate adsorption capacity under load), can predict absorption behavior in actual use at an easy rate to a certain extent.
That is to say, be under the very little situation if destroy the component content of water-absorbing resin in actual use, or the variation of urine is not under the very big situation in actual use, may assess the absorbability of water-absorbing resin.Yet, if consider in actual use, the content that destroys the composition of water-absorbing resin may be big, or urine can change, then above-mentioned under load condition the new capability adsorption capacity that needs at least in actual use of water-absorbing resin seemingly of approximate adsorption capacity.
To be water absorbing agent (resin) handle the adsorption capacity that the back measures through following to described approximate adsorption capacity under load under load: make water absorbing agent swell to 15 times with physiological sodium chloride solution conduct liquid to be adsorbed, then with this swelling water absorbing agent leave standstill certain hour.Approximate adsorption capacity under load is a new assessment item of water absorbing agent.Following two kinds under load condition approximate adsorption capacity (1) and (2) be according to swelling the time of repose of water absorbing agent provide as an example.When resin adsorbed urine once more, how its inherent absorbability that still keeps changed because of the urine effect after water-absorbing resin absorption urine can be judged in the adsorption capacity under the load condition (1) and (2).
Approximate adsorption capacity (1) under load of the present invention is the adsorption capacity by the water absorbing agent of following step measurements:
Form a kind of water absorbing agent, this water absorbing agent swells to 15 (g/g) with physiological sodium chloride solution;
This water absorbing agent was stayed under such solvent swelling state 2 hours;
On swollen water absorbing agent, add the load of 50g/cm2, and make it under this state, adsorb physiological sodium chloride solution again 1 hour; With
The weight of the swell gel that measures.
In the present invention, preferred water absorbing agent is 30 (g/g) or higher in the adsorption capacity under non-loaded, and its above-mentioned approximate adsorption capacity (1) under load is 23 (g/g) or higher.Under this situation, described water absorbing agent above-mentioned static state under load condition destroy in adsorption capacity (1)～(4), the dynamic destruction adsorption capacity under load condition and the new capabilities such as destruction adsorption exponent under the load condition one, two or more, can have above-mentioned specific value or bigger value.As if being lower than 30 (g/g) in non-loaded adsorption capacity down, then absorbability is insufficient, and situations such as leakage take place easily, particularly when water absorbing agent is used in the absorbent articles with high resin concentration.Adsorption capacity under non-loaded preferably is at least 33 (g/g), more preferably is at least 35 (g/g).In addition, if the approximate adsorption capacity (1) under load condition is lower than 23 (g/g), then similarly, the absorbability of absorbent articles is insufficient, and situations such as leakage are easy to take place, and therefore can't obtain stable absorption property.Approximate adsorption capacity (1) under load condition preferably is at least 24 (g/g), more preferably is at least 25 (g/g).
Approximate adsorption capacity (2) under load of the present invention is the adsorption capacity by the water absorbing agent of following step measurements:
Form a kind of water absorbing agent, this water absorbing agent swells to 15 (g/g) with physiological sodium chloride solution;
This water absorbing agent was stayed under such solvent swelling state 6 hours;
On swollen water absorbing agent, add 50g/cm 2Load, and make it under this state, adsorb physiological sodium chloride solution again 1 hour; With
The weight of the swell gel that measures.
In the present invention, also preferred water absorbing agent is 30 (g/g) or higher in the adsorption capacity under non-loaded, and its above-mentioned approximate adsorption capacity (2) under load is 20 (g/g) or higher.Under this situation, described water absorbing agent the static state under the load condition destroy in adsorption capacity (1)～(4), dynamic destruction adsorption capacity under load condition and the new capabilities such as destruction adsorption exponent under the load condition one, two or more, can have above-mentioned specific value or bigger value.As if being lower than 30 (g/g) in non-loaded adsorption capacity down, then absorbability is insufficient, and situations such as leakage take place easily, particularly when water absorbing agent is used in the absorbent articles with high resin concentration.Adsorption capacity under non-loaded preferably is at least 33 (g/g), more preferably is at least 35 (g/g).In addition, if the approximate adsorption capacity (2) under load condition is lower than 20 (g/g), then similarly, the absorbability of absorbent articles is insufficient, and situations such as leakage are easy to take place, and therefore can't obtain stable absorption property.Approximate adsorption capacity (2) under load condition preferably is at least 23 (g/g).
The present invention also provides a kind of new water absorbing agent, it preferably have specific value or bigger value in adsorption capacity under the no-load condition and approximate adsorption capacity (1)～(2) under load condition.This water absorbing agent is suitable for having the diaper of higher resin concentration and lower fiber base material concentration, higher resin concentration and lower fiber base material concentration be since in recent years diaper day by day attenuation cause that and this water absorbing agent can also reduce leakage phenomenon in actual use.
The preferred adsorption rate of water absorbing agent of the present invention is 20～80 seconds, and hydrotrope content is 1～15wt%.Hydrotrope content is preferably 2～15wt%, more preferably 2～10wt%.Under adsorption rate surpassed 80 seconds situation, the speed that comprises the adsorbing material of water absorbing agent or goods adsorptive liquid was too slow, to such an extent as to after 60 minutes a large amount of liquid inclinations in desorbing.Be less than at adsorption rate under 20 seconds the situation, comprise the excessive velocities of the adsorbing material or the goods adsorptive liquid of water absorbing agent, to such an extent as to very easy formation blob of viscose.In the adsorbing material or goods of the weight ratio (resin concentration) with high water absorbing agent and water absorbing agent and fiber base material summation, these phenomenons very seriously take place.In addition, the water absorbing agent producing cost that hydrotrope content is lower than 1% (weight) is very high, and therefore production is very difficult, and when hydrotrope content reduced, the adsorption capacity under non-loaded usually can reduce.If hydrotrope content is higher than 15% (weight), then be difficult to make static state destruction adsorption capacity, the dynamic destruction adsorption capacity under load and the destruction adsorption exponent under load under load of the water absorbing agent that obtains to fall within the scope of this invention, perhaps be difficult to make the approximate adsorption capacity of water absorbing agent under load that obtains to drop in the aforesaid preferable range.
As for water-absorbent agent composition of the present invention, comprise that water-absorbing resin is preferred as the compositions of solvent.
Water absorbing agent with above-mentioned special parameter of the present invention for example can adopt a kind of the obtaining in following two kinds of methods:
1. with specific aminopolycanboxylic acid with can mix with water-absorbing resin, thereby make the method for this resin crosslinks with the surface crosslinking agent of carboxyl reaction on the water-absorbing resin;
2. specific aminopolycanboxylic acid is joined the method in the specific surface-crosslinked water-absorbing resin that under load, has 23 (g/g) or higher adsorption capacity.
Yet the method that obtains water absorbing agent of the present invention is not limited to said method.
Below will describe the manufacture method of water absorbing agent of the present invention in detail.
The water-absorbing resin that is used to produce water absorbing agent of the present invention is common known resin, and it can adsorb 50～1000 times water of himself amount and form hydrogel in ion exchange water.The example of such water-absorbing resin comprises: the neutral polyacrylic cross linked polymer of part; The hydrolyzate of starch-acrylonitrile grafting polymer; The hydrolyzate of starch-acrylic acid-grafted polymer; The saponification resultant of vinyl acetate-acrylate copolymer; The hydrolyzate of acrylonitrile copolymer or acrylamide copolymer or their cross linked polymer; The saponification resultant that contains the cross-linking polyvinyl alcohol of carboxyl; With crosslinked isobutene-maleic anhydride copolymer.In these water-absorbing resins, the polymer that contains carboxyl is preferred, and normally is the monomer polymerization and crosslinked the obtaining of acrylic acid and/or its salt (neutralized reaction product) by main component.In addition, for above-mentioned water-absorbing resin, use be that those contained uncrosslinked water-soluble substance amounts are 25% (weight) or lower, preferred 15% (weight) or lower, more preferably 10% (weight) or lower water-absorbing resin.Carboxyl-content in the water-absorbing resin is not had special restriction, but contain 0.01 equivalent or higher in preferred every 100g water-absorbing resin.For example, polyacrylic neutralization ratio is preferably 1～60mol%, more preferably 10～50mol%.
The example of aforesaid propylene hydrochlorate comprises: acrylic acid alkali metal salt (for example sodium, potassium and lithium salts), ammonium salt, and amine salt.The component units of above-mentioned water-absorbing resin preferably includes 0～50mol%, the more preferably acrylic acid of 10～40 mol% and 100～50 mol%, the more preferably acrylates of 90～60mol% (wherein the summation of the two is 100 mol%).The carrying out of neutralization reaction, in both can be before polyreaction and monomer, also can be in polyreaction or the polymer that obtains of polyreaction post neutralization, but consider from production cost, in preferably before polyreaction and monomer, need the long time because polymer neutralized.
If desired, except that aforesaid propylene acid (salt), the monomer that is used to produce water-absorbing resin of the present invention can also comprise other monomer.Other monomer except that acrylic acid (salt) there is not special restriction, but the example comprises: the anion unsaturated monomer, as methacrylic acid, maleic acid, vinyl sulfonic acid, styryl sulfonic acid, 2-(methyl) acrylamido-2-methyl propane sulfonic acid, 2-(methyl) acryloyl group ethane sulfonic acid and 2-(methyl) acryloyl group propane sulfonic acid, and their salt; The nonionic unsaturated monomer that contains hydrophilic group, as acrylamide, Methacrylamide, N-ethyl (methyl) acrylamide, N-n-pro-pyl (methyl) acrylamide, N-isopropyl (methyl) acrylamide, N, N-dimethyl (methyl) acrylamide, (methyl) acrylic acid 2-hydroxyl ethyl ester, (methyl) acrylic acid 2-hydroxypropyl acrylate, methoxy poly (ethylene glycol) (methyl) acrylate, polyethyleneglycol (methyl) acrylate, vinylpyridine, N-vinyl pyrrolidone, N-acryloyl group piperidines and N-acryloyl group pyrrolidine; The cation unsaturated monomer, as (methyl) acrylic acid N, N-dimethyl aminoethyl ester, (methyl) acrylic acid N, N-diethylamino ethyl ester, (methyl) acrylic acid N, N-dimethylaminopropyl ester, N, N-dimethylaminopropyl (methyl) acrylamide and their quaternary ammonium salt.These monomers promptly can use separately, and use also can mutually combine.
In the present invention, when other monomer of using except that acrylic acid (salt), the ratio of the summation of they and acrylic acid and acrylates is preferably 30mol% or lower, more preferably 10mol% or lower.If the above-mentioned monomer except that acrylic acid (salt) uses with aforementioned proportion, the water absorbing properties of the water-absorbing resin that then obtains can be improved, and can obtain water-absorbing resin with low cost.
When the water-absorbing resin that obtains using among the present invention with above-mentioned monomer polymerization, can adopt polymerisation in bulk and precipitation polymerization.Yet, consider the performance of water-absorbing resin or the difficulty or ease of polyreaction control, preferably adopt aqueous solution polymerization or inverse suspension polymerization, monomer uses with the form of aqueous solution.When monomer uses with the aqueous solution form, the concentration of monomer in its aqueous solution (after this being called monomer solution) is had no particular limits, but be preferably 10～70% (weight), more preferably 20～40% (weight).In addition, when adopting above-mentioned aqueous solution polymerization or inverse suspension polymerization, also can be used in combination the solvent beyond dewatering if desired, and the solvent types that is used in combination is had no particular limits.
For causing above-mentioned polyreaction, for example can adopt following radical polymerization initiator: potassium peroxydisulfate, Ammonium persulfate., sodium peroxydisulfate, tert-butyl hydroperoxide, hydrogen peroxide and 2,2, two (2-amidine propane) dihydrochloride of-azo.
And, accelerate the decomposition of above-mentioned polymerization initiator and the two is used in combination by further use Reducing agent, obtain redox initiator.The example of described Reducing agent comprises: sulfurous acid (hydrogen) salt, for example sodium sulfite and sodium sulfite; L-ascorbic acid (or its salt); Reducing metal (or their salt), for example ferrous salt; And amine.But Reducing agent is not limited to these.
The consumption of described polymerization initiator is generally 0.001～2mol%, preferred 0.01～0.1mol%.When the consumption of polymerization initiator is lower than 0.001 mol%, there is disadvantage, promptly have a large amount of monomer unreacteds, the content of monomer in the water-absorbing resin that obtains is increased.On the other hand, when the consumption of polymerization initiator surpasses 2mol%, also have disadvantage, the hydrotrope content in the water-absorbing resin that promptly obtains increases.
In addition, also can come initiated polymerization, for example can use radiation, electron beam and ultraviolet to replace polymerization initiator with active high-energy ray irradiation reaction system.Reaction temperature in above-mentioned polyreaction is had no particular limits, but be preferably 20-90 ℃.In addition, the response time is also had no particular limits, for example can suitably set according to monomeric kind and factors such as polymerization initiator and reaction temperature.
Water-absorbing resin used in this invention can be a self-crosslinking type of not using cross-linking agent, but preferred use is to adopt per molecule to have two or more polymerizable unsaturated groups, or the combined polymerization of the internal crosslinker of two or more reactive groups or product.
The instantiation of described internal crosslinker comprises: N, N-di-2-ethylhexylphosphine oxide (methyl) acrylamide, (gathering) ethylene glycol (methyl) acrylate, (gathering) propylene glycol two (methyl) acrylate, trimethylolpropane tris (methyl) acrylate, glycerol three (methyl) acrylate, glycerol acrylic acid and methacrylic acid mixed ester, oxirane modification trimethylolpropane tris (methyl) acrylate, tetramethylolmethane four (methyl) acrylate, triallyl cyanurate, triallyl isocyanurate, TAP, triallylamine, many (methyl) allyloxy alkane, (gathering) Ethylene glycol diglycidyl ether, glycerol diglycidyl ether, ethylene glycol, Polyethylene Glycol, propylene glycol, glycerol, tetramethylolmethane, 1, the 2-ethylenediamine, ethylene carbonate, propylene carbonate, polyaziridine and (methyl) glycidyl acrylate.
These internal crosslinkers both can have been distinguished use separately, and use also can mutually combine.In addition, these internal crosslinkers promptly can once all be added in the reaction system, also can add in batches.When using two or more internal crosslinkers, consider the performance of the water-absorbing resin that obtains, the preferred main chemical compound that uses with two or more polymerizable unsaturated groups.The use of internal crosslinker can make soluble constituent avoid dissociating out from swell gel inside when swell gel is exposed in the destructive condition.
The consumption of described internal crosslinker is preferably 0.005～2mol% of above-mentioned hydrophilic monomer amount, more preferably 0.02～0.5mol%, most preferably 0.03～0.3mol%.Be lower than 0.005mol% respectively and be higher than under the situation of 2mol% at the consumption of internal crosslinker, make water-absorbing resin static under load or dynamically destroy adsorption capacity, destroy adsorption exponent or approximate adsorption capacity reaches the level of expectation or make water-absorbing resin show that good urine patience is impossible.
When using above-mentioned internal crosslinker in the inner introducing of water-absorbing resin cross-linked structure, this internal crosslinker can be in the polymerization process of above-mentioned hydrophilic monomer or polymerization join in the reaction system after finishing, or after polymerization and neutralization reaction finish, be added in the reaction system.
In above-mentioned polyreaction, can in reaction system, add following material: various foaming agent, for example carbonate (or bicarbonate), carbon dioxide, azo-compound and inert organic solvents; Hydrophilic polymer, for example cross linked polymer of starch series fiber element, its derivant, polyvinyl alcohol, polyacrylic acid (or its salt) and polyacrylic acid (or its salt); Various surfactants; And chain-transferring agent, for example hypophosphorous acid (or its salt).
When the water-absorbing resin that obtains with above-mentioned polyreaction was gel, this water-absorbing resin carried out drying usually, and if desired, pulverizes.
The water content (wet basis) that can be used for water-absorbing resin of the present invention is had no particular limits, but be preferably for 1～40% (but not comprising 40%), more preferably 1～20%, most preferably 1～10%.In addition, the average particulate diameter that can be used for water-absorbing resin of the present invention is generally 10～1000 microns, and preferred 50～800 microns, more preferably 75～600 microns (but not comprising 75 microns), preferred especially 150～500 microns (but not comprising 150 microns).The particle shape of the water-absorbing resin that obtains by this way for example can be spheric, powdered or irregular, and it is had no particular limits, but preferred the use has irregular powder shape, as the water-absorbing resin that obtains by pulverising step.
As for by as above before surface-crosslinked, carry out the water-absorbing resin that polymerization, drying and pulverising step obtain, preferably use those to be 30g/g or higher in non-loaded adsorption capacity down, preferred 35g/g or higher water-absorbing resin are because use such water-absorbing resin can significantly show effect of the present invention.Certainly, above-mentioned adsorption capacity can be carried out suitable adjusting according to application target.
-interpolation aminopolycanboxylic acid-
Water absorbing agent of the present invention with aforementioned parameters for example can obtain in the following way: specific aminopolycanboxylic acid cited below and surface crosslinking agent are mixed with the surface-crosslinked preceding water-absorbing resin that obtains above, crosslinked this resin, wherein surface crosslinking agent can with the carboxyl reaction of water-absorbing resin.
Available specific aminopolycanboxylic acid in the present invention is the amino carboxylic acid with three or more carboxyls or its salt.Such aminopolycanboxylic acid has high ion sealing or sequestering power to ferrum or copper, and its stability constant to iron ion preferably is at least 10, more preferably is at least 20.Its instantiation is as follows: diethylene-triamine pentaacetic acid, triethylenetetraaminehexaacetic acid, cyclohexane extraction-1,2-ethylenediamine tetraacetic acid (EDTA), the N-hydroxyethyl-ethylenediamine triacetic acid, the ethylene glycol diethyl ether ethylenediamine tetraacetic acid (EDTA), ethylene diamine four propanoic acid, N-alkyl-N,-carboxymethyl asparagic acid, N-alkenyl-N ,-carboxymethyl asparagic acid and their alkali metal salt, alkali salt, ammonium salt and amine salt.Wherein, diethylene-triamine pentaacetic acid, triethylenetetraaminehexaacetic acid, N-hydroxyethyl-ethylenediamine triacetic acid and their salt are most preferred, because they have huge structure or configuration.
Above-mentioned specific aminopolycanboxylic acid's use amount is according to the surface crosslinking agent that is used for crosslinked nearly surface portion that uses and difference, but per usually 100 parts of (weight) water-absorbing resin solid constituents are used 0.00001～10 part (weight), preferred 0.0001～1 part (weight).When consumption surpasses 10 parts (weight), can not get effect corresponding to consumption, so not only uneconomical, and the problem of bringing adsorbance to reduce.In addition, when consumption was lower than 0.00001 part (weight), the static state under load destroys adsorption capacity or approximate adsorption capacity almost can not get improving.
The example that can be used for the surface crosslinking agent among the present invention comprises: polyol compound, ethylene glycol for example, diethylene glycol, 1, the 2-propylene glycol, 2,2'-ethylenedioxybis(ethanol)., tetraethylene glycol (TEG), Polyethylene Glycol, 1, ammediol, two (propylene glycol), 2,2,4-trimethyl-1, the 3-pentanediol, poly-(propylene glycol), glycerol, polyglycereol, 2-butylene-1, the 4-glycol, 1,3 butylene glycol, 1, the 4-butanediol, 1, the 5-pentanediol, 1, the 6-hexanediol, 1, the 2-hydroxymethyl-cyclohexane, 1, the 2-cyclohexanediol, trimethylolpropane, diethanolamine, triethanolamine, polypropylene oxide, ethylene oxide-oxypropylene block copolymer, tetramethylolmethane and sorbitol; Epoxide, for example Ethylene glycol diglycidyl ether, polyethyleneglycol diglycidylether, glycerol polyglycidyl ether, two glycerol polyglycidyl ethers, polyglycereol polyglycidyl ether, propylene glycol diglycidylether, poly-(propylene glycol) diglycidyl ether and (+)-2,3-Epoxy-1-propanol; Polyamine compounds, for example ethylenediamine, diethylenetriamines, trien, tetren, penten and polyethylene imine, and their inorganic or organic salt (for example azetidine salt); Polyisocyanate compound, for example 2,4-inferior cresyl vulcabond and hexamethylene vulcabond; Duo oxazoline chemical compound, for example 1,2-Ya Yi Ji bisoxazoline; The alkylene carbonate ester compounds, for example 1,3-dioxolanes-2-ketone, 4-methyl isophthalic acid, 3-dioxolanes-2-ketone, 4,5-dimethyl-1,3-dioxolanes-2-ketone, 4,4-dimethyl-1,3-dioxolanes-2-ketone, 4-ethyl-1,3-dioxolanes-2-ketone, 4-methylol-1,3-dioxolanes-2-ketone, 1,3-dioxane-2-ketone, 4-methyl isophthalic acid, 3-dioxane-2-ketone, 4,6-dimethyl-1,3-dioxane-2-ketone and 1,3-two oxa-ring-2-in heptan ketone; Halogenated epoxide, for example epoxychloropropane, epoxy bromopropane and Alpha-Methyl-epoxychloropropane, and their polyamines addition product (for example the Hercules registered trade mark of producing is the chemical compound of Kymene); Silane coupler, for example γ-(+)-2,3-Epoxy-1-propanol oxygen propyl trimethoxy silicane and γ-An Jibingjisanyiyangjiguiwan; And polyvalent metal compounds, for example hydroxide of zinc, calcium, magnesium, aluminum, ferrum and zirconium and chloride.Especially, consider the safety under the unreacted situation of part surface cross-linking agent, preferably use polyhydric alcohol and alkylene carbonate ester compounds.
The above-mentioned surface crosslinking agent of enumerating both can have been distinguished use separately, the use of also can interosculating.When two or more surface crosslinking agents mutually combine when using, be used in combination the water absorbing agent that have different solubility parameters first and second surface crosslinking agents of (SP value) can obtain having excellent absorption property.Above-mentioned solubility parameter is to be commonly used to weigh the polar parameter of chemical compound.
Above-mentioned first surface cross-linking agent is and to have solubility parameter 12.5 (cal/cm with the carboxyl reaction of water-absorbing resin 3) 1/2 or higher chemical compound.The example of first surface cross-linking agent comprises ethylene glycol, propylene glycol, glycerol, ethylene carbonate and propylene carbonate.Above-mentioned second surface cross-linking agent is to be lower than 12.5 (cal/cm with the carboxyl reaction and the solubility parameter of water-absorbing resin 3) 1/2Chemical compound.The example of second surface cross-linking agent comprises glycerol polyglycidyl ether, (gathering) glycerol polyglycidyl ether, Ethylene glycol diglycidyl ether, 1, ammediol, trimethylolpropane, 1, ammediol, 1,6-hexanediol, diethylene glycol, 2,2'-ethylenedioxybis(ethanol)., tetraethylene glycol (TEG) and 1,4-butanediol.
The surface crosslinking agent that uses and the ratio of water-absorbing resin change according to factor such as the combination of water-absorbing resin and surface crosslinking agent, but 0.005～10 part (weight) of water-absorbing resin use under per 100 parts of (weight) drying regimes usually, preferred 0.05～5 part (weight).If the consumption of surface crosslinking agent is in this scope,, can be further improved as the absorption property of urine, antiperspirant and menstrual blood then to body fluid (water fluid).When the consumption of surface crosslinking agent during less than 0.005 part (weight), the crosslink density of the nearly surface portion of water-absorbing resin does not almost improve, static under load or dynamically destroy adsorption capacity, destroy adsorption exponent or approximate adsorption capacity can not get improving.In addition, when the consumption of surface crosslinking agent surpasses 10 parts (weight), the surface crosslinking agent surplus, this is uneconomic, and be difficult to the control crosslink density, so static under load or dynamically destroy adsorption capacity, destroy adsorption exponent or approximate adsorption capacity can not get improving to suitable value.
In the present invention, when mixing with specific aminopolycanboxylic acid and surface crosslinking agent, water-absorbing resin preferably makes water.The amount of the water that uses among the present invention is according to kind, granular size or the water content of water-absorbing resin and difference, but per usually 100 parts of (weight) water-absorbing resin solid constituents are used 0.5～10 part (weight), preferred 0.5～3 part (weight).When the amount of water surpassed 10 parts (weight), adsorption capacity may reduce.When the amount of water is lower than 0.5 part (weight), be difficult to will specific aminopolycanboxylic acid to be fixed to the surface of water-absorbing resin, so static under load or dynamically destroy adsorption capacity, destroy adsorption exponent or approximate adsorption capacity can not get raising.
In addition in the present invention, when mixing with specific aminopolycanboxylic acid and surface crosslinking agent, water-absorbing resin can use hydrophilic organic solvent.The example of operable hydrophilic organic solvent comprises: alcohol, for example methanol, ethanol, propanol, isopropyl alcohol, butanols, isobutanol, the tert-butyl alcohol and 1,2-propylene glycol; Ketone, for example acetone; Ether, for example dioxane, alkoxyl (gathering) ethylene glycol and oxolane; Amide, N for example, dinethylformamide; And sulfoxide, for example dimethyl sulfoxine.The consumption of hydrophilic organic solvent is according to the kind of water-absorbing resin or granular size and difference, but per usually 100 parts of water-absorbing resins use 0～10 part (weight), preferred 0.1～5 part (weight).
In the present invention, water-absorbing resin can be to finish under water-absorbing resin being dispersed in as the state in the organic solvent of cyclohexane extraction or pentane with mixing of specific aminopolycanboxylic acid and surface crosslinking agent.Yet following method (1)～(5) preferably are enumerated as the method that can represent characteristics of the present invention:
(1) a kind of method that comprises the steps: with specific aminopolycanboxylic acid and surface crosslinking agent, can comprise water and/or hydrophilic organic solvent if desired, mix; With the spraying of the mixture that obtains or be added drop-wise in the water-absorbing resin, they are mixed then.
(2) a kind of method that comprises the steps: with water-absorbing resin and specific aminopolycanboxylic acid or its aqueous solution; With surface crosslinking agent, can comprise water and/or hydrophilic organic solvent if desired then, spray or be added drop-wise in the mixture that obtains.
(3) a kind of method that comprises the steps: with surface crosslinking agent, can comprise water and/or hydrophilic organic solvent if desired, spray or be added drop-wise in the water-absorbing resin, they are mixed; Then with the mixture that obtains and specific aminopolycanboxylic acid or its aqueous solution.
(4) a kind of method that comprises the steps: adopt for example method of two nozzles,, can comprise water and/or hydrophilic organic solvent if desired, spray simultaneously or be added drop-wise in the water-absorbing resin with surface crosslinking agent and specific aminopolycanboxylic acid.
(5) a kind of method that comprises the steps: specific aminopolycanboxylic acid is added in the hydrogel of water-absorbing resin; Dry or the dehydration with hydrogel then; With surface crosslinking agent, wherein can comprise water and/or hydrophilic organic solvent if desired then, spray or be mixed in the drying or dehydration product that obtains (in the method, surface crosslinking agent also can add) in the step of hydrogel is dry or dehydration.
In addition, as previously mentioned, when specific aminopolycanboxylic acid and surface crosslinking agent mix with water-absorbing resin, preferably their waters or hydrophilic organic solvent are prepared into solution and mix.If specific aminopolycanboxylic acid and water-absorbing resin are to mix in the presence of water, the static state that then can improve under load is destroyed adsorption capacity or approximate adsorption capacity value.When water is used for mixed process, can allow to exist water-fast particulate powders or surfactant.
The mixing arrangement that is suitable for above-mentioned mixed process requires to produce big mixing force, to guarantee mix homogeneously.The example that can be used for preferred mixing arrangement of the present invention comprises: column mixer, double-walled cone blender, high-speed stirring mixer, V-type blender, ribbon blender, helical mixer, fluidisation stove rotating pan mixer, fluidized bed mixer, double arm kneading mixer, internal mixture is pulverized kneader, impeller, and screw extruder.
In the present invention, specific aminopolycanboxylic acid and surface crosslinking agent mix with water-absorbing resin and (preferably specific aminopolycanboxylic acid and surface crosslinking agent are mixed, be added in the water-absorbing resin then), make the nearly surface portion of water-absorbing resin carry out crosslinked by further heat treatment then.
When heat-treating in the present invention, treatment temperature is preferably 80～250 ℃.If heat treatment temperature is lower than 80 ℃, heat treatment time is prolonged also therefore reduce productivity ratio, and it is crosslinked uniformly to be difficult to formation, and therefore is difficult to produce the water absorbing agent that has good static destruction adsorption capacity under load, and this is one of purpose of the present invention.In addition,, then may destroy water-absorbing resin, thereby be difficult to obtain at the negative water absorbing agent that has good static state or dynamically destroy adsorption capacity, destruction adsorption exponent or approximate adsorption capacity of planting if heat treatment temperature is higher than 250 ° of C.
Heat treatment can be finished with common exsiccator or heating furnace, and the example comprises: drying tunnel formula mixing drier, rotary drum drier, desk-top exsiccator, fluidized bed dryer, pneumatic conveyer dryer, and infrared dryer.
In addition, according to the production method of another kind of water absorbing agent of the present invention, comprise that it is step in 23 (g/g) or the higher surface-crosslinked water-absorbing resin that above-mentioned specific aminopolycanboxylic acid is added under load adsorption capacity.
Surface-crosslinked as used herein water-absorbing resin is normally by mixing with aforesaid surface crosslinking agent and carry out crosslinked obtaining with the surface-crosslinked water-absorbing resin that do not carry out as yet that preceding method obtains.
It is 23 (g/g) or higher that described surface-crosslinked water-absorbing resin requires the adsorption capacity under load.If the adsorption capacity under load is lower than 23 (g/g), then the destruction of the static state under load adsorption capacity can not fall within the scope of this invention, or the static state under load is with dynamically destruction adsorption capacity and approximate adsorption capacity absolute value separately are low, even make and consider use for a long time, diaper also is inadequate to the absorption of water.Adsorption capacity under load preferably is at least 24 (g/g), more preferably is at least 25 (g/g).
In the present invention, be that above-mentioned specific aminopolycanboxylic acid is added under load adsorption capacity is in 23 (g/g) or the higher surface-crosslinked water-absorbing resin, but following method is preferred: specific aminopolycanboxylic acid is prepared into aqueous solution, and water combines water absorbing resin particle as binding agent and with the resin pelletize.Pelletize increases the mean diameter of water-absorbing resin, and improves wet resin flow, thereby makes resin more easy to operate.The amount of the water that per usually 100 parts of (weight) water-absorbing resins add is 0.1～20 part (weight), is preferably 0.1～10 part (weight), more preferably 0.5～4 part (weight).
The method of adding specific aminopolycanboxylic acid and water is not had special restriction, and the example comprises: specific aminopolycanboxylic acid's aqueous solution is joined in the water-absorbing resin also therefore with the resin process for granulating; With specific aminopolycanboxylic acid is joined in the water-absorbing resin, therefore then water is joined in the resin, and with the resin process for granulating.Can also use hydrophilic organic solvent, for example methanol, ethanol, isopropyl alcohol or propylene glycol improve the miscibility of specific aminopolycanboxylic acid and water and water-absorbing resin.And, before or simultaneously, can also add surfactant or inorganic matter fine grained, for example silicon dioxide or titanium dioxide.
The interpolation of ion sealer (or chelating agen) is not limited to said method.As previously mentioned, can by with aminopolycanboxylic acid and surface crosslinking agent with surface-crosslinked before water-absorbing resin mix and that water-absorbing resin is carried out is surface-crosslinked, perhaps by in the water-absorbing resin that aminopolycanboxylic acid and water is joined specific surface-crosslinked mistake and with the resin process for granulating, and the ion sealer (or chelating agen) that will be selected from the aminopolycanboxylic acid is fixed on the surface of water-absorbing resin.Because degenerating of water-absorbing resin begins to take place from its surface, so preferably ion sealer (or chelating agen) is placed the nearly surface portion of water-absorbing resin.Ion sealer (or chelating agen) can add when polymerisation generates water-absorbing resin.Yet, when above-mentioned monomer carries out polymerization in the presence of ion sealer (or chelating agen), ion sealer (or chelating agen) may hinder monomeric polymerization, therefore and may can not get having the water-absorbing resin of superior absorbability, and ion sealer (or chelating agen) may lose its sealing or sequestering power.
The water absorbing agent that obtains as stated above has the premium properties that in the past never must be, promptly adsorption capacity value under non-loaded and static under load or dynamically destroy adsorption capacity, destroy adsorption exponent or approximate adsorption capacity value good.Such water absorbing agent was suitable for use in the popular day by day in recent years slim diaper with high resin content and low pulp content, and this water absorbing agent can reduce leakage in actual use.
In a preparation method of the present invention,, and obtain having the water absorbing agent of excellent urine patience for example with ion sealer and mixing with the above-mentioned water-absorbing resin that contains carboxyl that obtains with the surface crosslinking agent of carboxyl reaction.
The example of the ion sealer of Shi Yonging comprises following compounds in the present invention:
(1) amino carboxylic acid and salt thereof; (2) monoalkyl citric amide, mono-alkenyl citric amide, and salt; (3) monoalkyl Malondiamide, mono-alkenyl Malondiamide, and salt; (4) monoalkyl phosphoric acid esters, mono-alkenyl phosphate ester, and salt; (5) N-acidylate glutamic acid, N-acidylate aspartic acid, and salt; (6) beta-diketo derivative; (7) Tropolone derivative; (8) organic phosphoric acid chemical compound.
As for (1) amino carboxylic acid and salt thereof, consider its ion sealing capacity, preferably those contain the chemical compound of at least three carboxyls.Instantiation comprises: nitrilotriacetic acid(NTA), ethylenediaminetetraacetic acid, diethylene-triamine pentaacetic acid, triethylenetetraaminehexaacetic acid, cyclohexane extraction-1,2-ethylenediamine tetraacetic acid (EDTA), the N-hydroxyethyl-ethylenediamine triacetic acid, the ethylene glycol diethyl ether ethylenediamine tetraacetic acid (EDTA), ethylenediamine tetrapropionic acid, N-alkyl-N,-carboxymethyl asparagic acid, N-alkenyl-N ,-carboxymethyl asparagic acid, and their alkali metal salt, alkali salt, ammonium salt and amine salt.
(2) monoalkyl citric amide, mono-alkenyl citric amide and salt thereof for example are to be got by pure and mild citric acid dehydrating condensation.
(3) monoalkyl Malondiamide, mono-alkenyl Malondiamide and salt thereof for example are to obtain by the addition product that alpha-olefin is added on the malonic acid methyl ester and hydrolysis obtains.
(4) example of monoalkyl phosphoric acid esters, mono-alkenyl phosphate ester and salt thereof comprises lauryl phosphoric acid and octadecyl phosphoric acid.
(5) example of N-acidylate glutamic acid, N-acidylate aspartic acid and salt thereof comprises Amisoft HS-11 and GS-11, can be by Ajinomoto Co., and Ltd. buys.
(6) example of beta-diketo derivative comprises acetylacetone,2,4-pentanedione and benzoyl acetone.
(7) example of Tropolone derivative comprises tropolone, β-Limonene Cesu and γ-thujaplicins.
(8) the organic phosphoric acid examples for compounds comprises the ethylidene phosphonic acids, 1-hydroxy ethylidene-1,1-di 2 ethylhexyl phosphonic acid, amino-trimethylene phosphonic acids, ethylenediamine tetraacetic (methylene phosphonic acid) and diethylenetriamines five (methylene phosphonic acid).1-hydroxy ethylidene-1 particularly, 1-di 2 ethylhexyl phosphonic acid, ethylenediamine tetraacetic (methylene phosphonic acid) and diethylenetriamines five (methylene phosphonic acid).The example of preferred organic phosphoric acid chemical compound salt comprises alkali metal salt (for example Na and K salt, ammonium salt and amine salt.Above-mentioned organic phosphoric acid chemical compound is known as metal enclosed dose.
The amino carboxylic acid and the salt thereof that in above-mentioned ion sealer, preferably contain at least three carboxyls, especially, consider urine patience, most preferably diethylene-triamine pentaacetic acid, triethylenetetraaminehexaacetic acid, cyclohexane extraction-1,2-ethylenediamine tetraacetic acid (EDTA), N-hydroxyethyl-ethylenediamine triacetic acid and salt thereof are because they have huge structure and configuration.
The consumption of intermediate ion sealer of the present invention is according to the employed surface crosslinking agent that is used for crosslinked nearly surface portion and difference, but its amount is generally per 100 parts of (weight) water-absorbing resin solid constituents with 0.0001～10 part (weight), preferably uses 0.0002～5 part (weight).If consumption surpasses 10 parts (weight), the problem of existence is that its consumption can not get effective repayment, and this is uneconomic, and adsorbance can reduce.In addition, if consumption is lower than 0.0001 part (weight), then can't improve urine patience.
The surface crosslinking agent that uses and the ratio of water-absorbing resin for example change according to the factor of combination of water-absorbing resin and surface crosslinking agent and so on, but per 100 parts (weight) dry water-absorbing resin consumption is 0.01～10 part (weight) usually, preferred 0.05～3 part (weight).If the surface crosslinking agent consumption is in above-mentioned scope, then to body fluid (water fluid), for example the absorption property of urine, antiperspirant and menstrual blood can be improved.If the surface crosslinking agent consumption is lower than 0.01 part (weight), the crosslink density of the nearly surface portion of water-absorbing resin almost can not get improving.In addition, if the consumption of surface crosslinking agent surpasses 5 parts (weight), surface crosslinking agent surplus then, this is uneconomic, and is difficult to the control crosslink density to suitable value.
In the present invention, when mixing with ion sealer and surface crosslinking agent, water-absorbing resin preferably makes water.The amount of the water that uses among the present invention is according to kind, granular size or the water content of water-absorbing resin and difference, but per usually 100 parts of water-absorbing resin solid constituents are used 0.5～10 part (weight), preferred 0.5～3 part (weight).When the amount of water surpassed 10% (weight), adsorption capacity can reduce.When the amount of water is lower than 0.5% (weight), is difficult to the ion sealer is fixed to the surface of water-absorbing resin, thereby can't improves urine patience.
Aforesaid all finish the method for aminopolycanboxylic acid's mixing and interpolation, except that above-mentioned aspect, need not revise, promptly can be used as in the production method of just having mentioned in front ion sealer and surface crosslinking agent and the blended ad hoc approach of water-absorbing resin.
If it is crosslinked that the nearly surface portion of water-absorbing resin carries out in the above described manner, can prevent that then soluble component from removing out from water-absorbing resin inside.Yet, when absorption contains the urine or the like of L-ascorbic acid, water-absorbing resin can be in time passing and retrogressive metamorphism because the L-ascorbic acid and in water-absorbing resin or diaper production process, mix to come on a small quantity or urine in the effect of the heavy metallic salt (for example ferrum and copper) that contains can cut off the main chain and the cross-linked structure of water-absorbing resin.Especially, the nearly surface portion of water-absorbing resin is easy to go bad, and makes to suppress removing of soluble constituent.Therefore, when the resin absorption urine, its adsorptivity is passed in time and is reduced.In the present invention, surface crosslinking agent and ion sealer are mixed in the water-absorbing resin, thereby have prevented the retrogressive metamorphism of water-absorbing resin, particularly its nearly surface portion, suppressed removing of soluble constituent.
In another production method of the present invention, water and described ion sealer are added in (for example using spray method) water-absorbing resin (carrying out surface-crosslinked with described surface crosslinking agent in advance), water makes the granule of water-absorbing resin bonded to one another to together as binding agent, carry out pelletize like this and make water-absorbing resin have good urine patience.Described water-absorbing resin can nearly surface portion is crosslinked to be obtained by being undertaken by the monomer water-absorbing resin that polymerization obtains in the presence of internal crosslinker that comprises unsaturated carboxylic acid.The swell gel that the use of internal crosslinker can prevent resin is being exposed to can make in its rotten condition the time, and soluble constituent removes out from resin swelling gel inside.Pelletize increases the mean diameter of water-absorbing resin, and improves wet resin flow, thereby makes resin more easy to operate.The amount of the water that per usually 100 parts of (weight) water-absorbing resins add is 0.1～20% (weight), is preferably 0.1～10% (weight), more preferably 0.5～4% (weight).If the consumption of water is less than 0.1% (weight), then with water-absorbing resin pelletize difficulty, and the ion sealer can not be fixed on the nearly surface portion of water-absorbing resin.In addition, if the consumption of water is more than 20% (weight), then water-absorbing resin can swelling up to its inside, thereby form gel, so may can not get the granulation product that the present invention needs, and the surface-crosslinked layer of water-absorbing resin may be damaged.In the method, the described surface-crosslinked water-absorbing resin adsorption capacity to 0.9wt% sodium-chloride water solution (physiological sodium chloride solution) under the load of 0.7psi of having carried out in advance should be at least 20 (g/g) usually, preferably be at least 22 (g/g), more preferably be at least 24 (g/g), because if the adsorption capacity under load is lower than 20 (g/g), then the water absorption of diaper may be not enough.
Prilling process to the interpolation that comprised the ion sealer has no particular limits, but the example also comprises following method except that method above-mentioned: the ion sealer is joined in the water-absorbing resin, add entry then, like this with the water-absorbing resin pelletize.Can be used in combination hydrophilic organic solvent, for example methanol, ethanol and isopropyl alcohol, but to reach the purpose of the compatibility that improves ion sealer, water and water-absorbing resin.In addition, can add surfactant and inorganic matter fine grained, for example silicon dioxide and titanium dioxide in advance or simultaneously.
In the present invention, can also be when stating the method polymerization and generate water-absorbing resin and/or thereafter by former, the chelating agen that adds ad hoc structure obtains having the water-absorbing resin of excellent urine patience.
The chelating agen that can be used for ad hoc structure of the present invention is that to be selected from chemical compound with following general formula (1) and (2) and maleic acid be one or both or more kinds of chemical compounds in the hydrophilic polymer (comprising salt) (3),
Its formula of (1) is:
Figure A20071016740900341
Wherein: n, X 1And R 1～R 3Representative is column of figure and structure down:
n＝0,1
X 1＝COOM 1(M 1＝H，Na，K，NH 4)
R 1＝H，OH，Me
R 2＝H，-CH 2COOM 2，-CH 2CH 2COOM 2(M 2＝H，Na，K，NH 4)
Figure A20071016740900351
(M 3＝H，Na，K，NH 4)(R 4＝H，OH，Me)
And general formula wherein (2) is:
Figure A20071016740900352
Wherein: m, X 2And R 5～R 8Representative is column of figure and structure down:
m＝0.1
X 2＝COOM 4(M 4＝H，Na，K，NH 4)
R 5＝H，OH，Me
R 6＝H，-CH 2COOM 5，-CH 2CH 2COOM 5(M 5＝H，Na，K，NH 4)
R 7＝H，-CH 2COOM 6，-CH 2CH 2COOM 6(M 6＝H，Na，K，NH 4)
(M 7＝H,Na,K,NH 4)(R 9＝H,OH,Me).
The example of the chelating agen of top general formula (1) comprising: N-carboxymethyl asparagic acid, N, N-two carboxymethyl asparagic acids, N-carboxyethyl aspartic acid, N, N-two carboxyethyl aspartic acids, N-(1,2-dicarboxyl ethyl)-aspartic acid, N-(1,2-dicarboxyl-2-hydroxyethyl)-aspartic acid, N-carboxymethyl-2-hydroxyl-aspartic acid, N, N-two carboxymethyls-2-hydroxyl-aspartic acid, N-carboxyethyl-2-hydroxyl-aspartic acid, N-(1,2-dicarboxyl ethyl)-2-hydroxyl-aspartic acid, N-carboxymethyl glutamic acid, N, N-two carboxymethyl glutamic acid, N-carboxyethyl glutamic acid, N, N-two carboxyethyl glutamic acid, N-(1,2-dicarboxyl ethyl)-glutamic acid, N-(1,2-dicarboxyl-2-hydroxyethyl)-glutamic acid and their sodium, potassium and ammonium salt.
The example of the chelating agen of top general formula (2) comprising: N, N ,-two (1,2-dicarboxyl ethyl)-1, N, N ,-two (1,2-dicarboxyl-2-hydroxyethyl)-1, the 2-ethylenediamine, N, N ,-two (1,2-dicarboxyl ethyl)-and N, N ,-dicarboxyl methyl isophthalic acid, 2-ethylenediamine, N, N ,-two (1,2-dicarboxyl-2-hydroxyethyl)-N, N ,-dicarboxyl methyl isophthalic acid, 2-ethylenediamine and their sodium, potassium and ammonium salt.
And being the example of hydrophilic polymer (comprising salt) (3), maleic acid comprising:
Hydrophilic polymer, by acrylic acid, methacrylic acid and their sodium, potassium and the ammonium salt polymerization of maleic acid, fumaric acid, itaconic acid and their sodium, potassium and ammonium salt and the 0～99mol% of 1～100mol% and obtain, and mean molecule quantity is 500～1,000,000;
Preferred hydrophilic, by the acrylic acid of the maleic acid of 5～100mol% and salt and 0～95mol% and salt polymerization thereof and obtain, and mean molecule quantity is 1,000～200,000; With
Preferred hydrophilic polymer, by the acrylic acid of the maleic acid of 10～50mol% and salt and 50～90mol% and salt polymerization thereof and obtain, and mean molecule quantity is 1,000～100,000.
In above-mentioned chelating agen, consider safety and biodegradable, preferably use the chelating agen of general formula (1) and (2).The chelating agen of general formula (1) and (2) can with its arbitrarily the form of optical isomer and modification racemic modification use.Particularly preferred example comprises: N-(1,2-dicarboxyl-2-hydroxyethyl)-aspartic acid, N, N ,-two (1,2-dicarboxyl ethyl)-1, N, N ,-two (1,2-dicarboxyl-2-hydroxyethyl)-1 and their sodium, potassium and ammonium salts.
Consumption to above-mentioned chelating agen has no particular limits, and changes according to the kind of chelating agen and adding method, but per usually 100 parts of (weight) water-absorbing resins use 0.00001～30 part (weight).
Chelating agen is added to the comprising of example of the method in the water-absorbing resin:
(1) (in polymerization process, adds): a kind ofly comprise that above-mentioned chelating agen is added to water-soluble polymerizable generates method in the aqueous solution of ethylenically unsaturated monomer of water-absorbing resin.May contain heavy metal in this monomer solution, split away off by pipeline or reactor, or contain in the raw material, for example caustic soda.When carrying out polyreaction in the presence of such heavy metal ion, then residual heavy metal ion may obtain the water-absorbing resin that is easy to go bad when swelling, perhaps make swollen gel be easy to go bad.Yet, in the presence of described chelating agen, can provide the water-absorbing resin of passing swell gel stability in time with excellence by above-mentioned monomer polymerization.
Preferably before polyreaction is carried out, chelating agen is added in the monomer solution.But chelating agen also can cause the back in polyreaction and add.The amount of the chelating agen that adds in polymerization procedure is generally per 100 parts of (weight) monomer solid content with 0.00001～1 part (weight), preferred 0.00002～0.1 part (weight), more preferably 0.00005～0.01 part (weight).If the consumption of chelating agen is lower than 0.00001 part (weight), then can't be passed water-absorbing resin in time with excellent swell gel stability.If the consumption of chelating agen surpasses 1 part (weight), then may hinder monomeric polymerization.
(2) (add in polymer gel): be added to method in hydrogel with above-mentioned chelating agen a kind of comprising, this hydrogel is to be obtained by the ethylenically unsaturated monomer polymerization that water-soluble polymerizable generates water-absorbing resin.
The solid content of hydrogel is generally 20～90% (weight).The gel that has added chelating agen can be used the commonsense method drying.Preferred 120 ℃ or higher of baking temperature.
The amount of the chelating agen that adds is generally per 100 parts of (weight) hydrogel solid contents with 0.00001～30 part (weight), preferred 0.00005～10 part (weight).If the consumption of chelating agen is lower than 0.00001 part (weight), then can't be passed water-absorbing resin in time with excellent swell gel stability.If the consumption of chelating agen surpasses 30 parts (weight), then its consumption can not get effective repayment, and perhaps water adsorption capacity can reduce rather than improve.
The hydrogel that is obtained by polyreaction, the hydrogel that is obtained by aqueous solution polymerization for example can be with the board-like drying of carrying out.Yet, the water absorbing agent performance of considering drying efficiency or obtaining, usually preferably that hydrogel is broken or cut into the size of 0.1～10mm.As for the shape of hydrogel, many kinds can be preferred for the present invention, for example: plate shaped, square, by pulverizing obtain irregularly shaped, sphere, fibrous, bar-shaped, class sphere, flakey.The hydrogel that is obtained by polymerization can neutralize with alkali subsequently.In addition, chelating agen can be suspended in and join in the organic solvent in the hydrogel that is obtained by inverse suspension polymerization, perhaps adds in the azeotropic dehydration step.
Above-mentioned chelating agen can join in the hydrogel in any step before the dry end of hydrogel.For example, chelating agen adds in the time of can forming hydrogel in reactor, perhaps adds in the broken step of hydrogel, perhaps joins in the breaked hydrogel, perhaps adds in dry run.
Especially, can be listed below method: the method that when the broken hydrogel of the instrument that uses kneader for example or meat grinder and so on, adds chelating agen; And near the charging aperture of drying machine, add the method for chelating agen.Can with powder type be dissolved or dispersed in water or other solvent in form use chelating agen.In addition, chelating agen also can be coated or be sprayed to the surface of hydrogel.
The hydrogel that has added chelating agen for example can carry out drying with hot-air drier, pneumatic conveyer dryer, fluidized bed dryer, drum dryer, microwave and infrared ray.Baking temperature is generally 120 ℃ or higher, and preferred 150～250 ℃, more preferably 160～220 ℃.Some dry temperature are lower than 120 ° of C, then dry time that need be oversize, and also hydrogel is long at the gel state heated time, therefore is easy to impaired.
(3) (be added to (situation 1) in the water-absorbing resin): can join method in (for example using mixed method) water-absorbing resin with above-mentioned chelating agen with the surface crosslinking agent of the functional group of functional group reactions on the water-absorbing resin with containing two or more a kind of comprising.
The amount of the described chelating agen that uses in the method is according to the employed cross-linking agent that is used for crosslinked nearly surface portion and difference, but the amount of chelating agen is generally per 100 parts of (weight) water-absorbing resin solid constituents with 0.0001～10 part (weight), preferred 0.0002～5 part (weight).If this amount surpasses 10 parts (weight), the problem of existence is: its consumption can not get effective repayment, and is therefore unfavorable economically, and adsorbance can reduce.In addition, if the consumption of chelating agen is lower than 0.0001 part (weight), then can't improve urine patience.
As for the surface crosslinking agent in this method, can use those of being set forth in aminopolycanboxylic acid's in front the interpolation.
The surface crosslinking agent that uses and the ratio of water-absorbing resin for example change according to the factor of combination of water-absorbing resin and surface crosslinking agent and so on, but the consumption of per 100 parts of (weight) dry water-absorbing resin surface crosslinking agents is generally 0.01～10 part (weight), preferred 0.05～3 part (weight).If the surface crosslinking agent consumption is in above-mentioned scope, then to body fluid (water fluid), for example the absorption property of urine, antiperspirant and menstrual blood can be improved.If the surface crosslinking agent consumption is lower than 0.01 part (weight), the crosslink density of the nearly surface portion of water-absorbing resin almost can not get improving.In addition, if the consumption of surface crosslinking agent surpasses 5 parts (weight), surface crosslinking agent surplus then, this is uneconomic, and is difficult to the control crosslink density to suitable value.
In the present invention, when mixing with chelating agen and surface crosslinking agent, water-absorbing resin preferably makes water.The amount of the water that uses among the present invention is according to kind, granular size or the water content of water-absorbing resin and difference, but the water yield that per usually 100 parts of (weight) water-absorbing resin solid constituents are used is 0.5～10 part (weight), preferred 0.5～3 part (weight).When the consumption of water surpassed 10 parts (weight), adsorption capacity may reduce.When the consumption of water is lower than 0.5 part (weight), is difficult to chelating agen is fixed to the surface of water-absorbing resin, thereby can't improves urine patience.
Aforesaid all finish the method for aminopolycanboxylic acid's mixing and interpolation, except that above-mentioned aspect, need not revise, promptly can be used as in this method (3) chelating agen and surface crosslinking agent and the blended method of water-absorbing resin.
(4) (be added to (situation 2) in the water-absorbing resin): the method during described chelating agen is joined water-absorbing resin surface-crosslinked.
Surface-crosslinked water-absorbing resin as preferred use, its adsorption capacity to 0.9wt% sodium-chloride water solution (physiological sodium chloride solution) under the load of 0.7psi is at least 20 (g/g) usually, preferably be at least 22 (g/g), more preferably be at least 24 (g/g).If its adsorption capacity is lower than 20 (g/g) under load, then the water absorption of diaper may be not enough.
The amount of employed chelating agen is generally per 100 parts of (weight) water-absorbing resin solid constituents with 0.00001～10 part (weight), preferred 0.0001～5 part (weight) in the method (4).If this amount surpasses 10 parts (weight), the problem of existence is: its consumption can not get effective repayment, and this is uneconomic, and adsorbance can reduce.In addition, if the consumption of chelating agen is lower than 0.00001 part (weight), then can't improve urine patience.
The example that is used for the method that described surface-crosslinked water-absorbing resin and chelating agen is admixed together in this method (4) comprises: under drying condition with described water-absorbing resin and chelating agen method admixed together; The mixture that the mixed solvent of chelating agen and water, organic solvent or water-organic solvent is formed is added to the method in the water-absorbing resin.
In this method (4), with water and described chelating agen be added to (for example using spray method) surface-crosslinked water-absorbing resin in, water makes the granule of water-absorbing resin bonded to one another to together as binding agent, like this resin is carried out pelletize.Pelletize increases the mean diameter of water-absorbing resin, and improves wet resin flow, thereby makes resin more easy to operate.The amount of the water that per usually 100 parts of (weight) water-absorbing resins add is 0～50% (weight), is preferably 0.01～10% (weight).If the consumption of water is less than 0.1% (weight), the then pelletize difficulty of water-absorbing resin, and chelating agen can not be fixed on the nearly surface portion of water-absorbing resin.In addition, if the consumption of water is more than 50% (weight), then water-absorbing resin can swelling up to its inside, thereby form gel, so may can not get the granulation product that the present invention needs, and the surface-crosslinked layer of water-absorbing resin may be damaged.
Prilling process to the interpolation that comprised chelating agen has no particular limits, but the example also comprises following method except that method above-mentioned: chelating agen is joined in the water-absorbing resin, add entry then, like this with the water-absorbing resin pelletize.Can be used in combination hydrophilic organic solvent, for example methanol, ethanol and isopropyl alcohol, but to reach the purpose of the compatibility that improves chelating agen, water and water-absorbing resin.And, can add surfactant and inorganic matter fine grained, for example silicon dioxide and titanium dioxide in advance or simultaneously.
(5) (be added to (situation 3) in the water-absorbing resin): the method for when reclaiming the water-absorbing resin fine powder, adding described chelating agen.
In some step of producing water-absorbing resin, for example, the polymer powder that forms water-absorbing resin may screen with the sieve of pre-sizing, and the fine powder that sifts out from water-absorbing resin in this screening process can add in any step of producing water-absorbing resin again, thereby reclaims.When carrying out the fine powder recovery, can add chelating agen.
As for water-absorbing resin, surface-crosslinked or uncrosslinked can the using in surface.Particle diameter to the water-absorbing resin that uses in removal process has no particular limits, but is generally 300 μ m or littler, preferred 225 μ m or littler, more preferably 150 μ m or littler.
The amount of per 100 parts of (weight) water that water-absorbing resin added is generally 0.1～2,000 part (weight), preferred 10～900 parts (weight).If the consumption of water less than 0.1 part (weight), then reclaims difficulty.If the consumption of water then can't prevent the water-absorbing resin retrogressive metamorphism that reclaims greater than 2,000 parts (weight).
The amount of the chelating agen that per 100 parts (weight) dry water-absorbing resin adds is generally 0.00001～30 part (weight), preferred 0.1～10 part (weight).If the consumption of chelating agen is lower than 0.00001 part (weight), then be difficult to obtain the water-absorbing resin that in time passing shows excellent gel stability.If the amount of chelating agen surpasses 30 parts (weight), then its consumption can not get effective repayment.
Both the form of chelating agen with aqueous solution can be added in the water-absorbing resin, also chelating agen can be added in the mixture of water-absorbing resin and water formation.In addition, also chelating agen can be mixed under drying condition with water-absorbing resin, and then the mixture that obtains is mixed with water.
In the presence of chelating agen, reclaim the water-absorbing resin fine powder in the above described manner, can prevent water-absorbing resin retrogressive metamorphism in removal process.
The interpolation of-other material-
If desired, by adding following material, can give above-mentioned water absorbing agent many functions: deodorizer, antimicrobial, aromatic, various inorganic material powders, foaming agent, pigment, dyestuff, the hydrophilic short fiber, plasticizer, contact adhesive, surfactant, fertilizer, oxidant, Reducing agent, water, and salt.
The example of inorganic material powders comprises inert substance (being nonactive to aqueous solution for example), the fine grained of for example various inorganic compound and clay mineral.Described inorganic material powders preferably has suitable affinity to water, and is insoluble or water-soluble hardly.Its concrete example comprises: metal-oxide, for example silicon dioxide and titanium dioxide; Silicic acid (or its salt), for example natural zeolite and artificial zeolite; Kaolin; Talcum; Clay; And bentonite.Wherein, preferred silicon dioxide and silicic acid (or its salt) more preferably have mean diameter 200 μ m or littler silicon dioxide and silicic acid (or its salt), and this particle diameter is recorded by Coulter Counter Method.
The ratio of inorganic material powders and water-absorbing resin is for example according to the factor of combination of water-absorbing resin and inorganic material powders and so on and change, but the consumption of per 100 parts of (weight) water-absorbing resin inorganic material powders is 0.001～10 part (weight) usually, preferred 0.01～5 part (weight).Mixed method to water-absorbing resin and inorganic material powders has no particular limits, and for example can adopt dried mixing method or wet-mix method, but dried mixing method is preferred.
The application of-water absorbing agent-
For example, by with described resin and fibrous material compound (combination), and will make absorbent articles by the water absorbing agent that said method obtains such as wood pulp.
The example of absorbent articles comprises: hygienic material (body fluid absorbent articles), for example diaper, sanitary towel, incontinence pad, Wound protection material and Wound healing and bone regeneration material; The absorbent articles that is used for the house pet urine; The material that is used for engineering and building industry, for example water-keeping material, the material that intercepts water, packaging material and be used for construction material or the hydrogel bag in soil; The goods that are used for food industry, for example hygroscopic material, Perserving materials and cold insulation material; Various industrial products, for example oil-water separation material, anti-mist material and the curing materials of falling; And agricultural and gardening goods, for example be used for the water-keeping material of plant or soil; But absorbent articles is not limited thereto.The preparation example of diaper is stacked together in this order by the top layer that the material of the backing layer that the impermeable material of a liquid is made, above-mentioned water absorption composition and a fluid permeable is made in this way, and be fixed together, add that adnexa for example assembles part (elastomeric element) or so-called fixing band for then final sandwich.In addition, diaper can comprise the underwear that has diaper, is used to train baby's defecation.
Below adsorbing material of the present invention is described in detail, show when application has the water absorbing agent of the present invention of above-mentioned parameter the good adsorption properties that has.
＜adsorbing material 〉
Above-mentioned water absorbing agent of the present invention can use with the form of adsorbing material.This adsorbing material comprises water absorbing agent and such as the fiber base material of hydrophilic fibers.The weight ratio of the gross weight of water absorbing agent and water absorbing agent and fiber base material is 0.4 or more.Comprise under the situation of (for example) water absorbing agent and hydrophilic fibers at absorbent material, comprise that the adsorbing material combinative structure of the homogeneous mixture of water absorbing agent and hydrophilic fibers is preferred for fully showing effect of the present invention.The example of this combinative structure comprises: the combinative structure that comprises the homogeneous mixture of water absorbing agent and hydrophilic fibers; Comprise that the homogeneous mixture layer and of a water absorbing agent and hydrophilic fibers is layered in the combinative structure of the hydrophilic fibers layer on the aforementioned layers; Comprise homogeneous mixture layer, a hydrophilic fibers layer of a water absorbing agent and hydrophilic fibers and place the combinative structure of above-mentioned water absorbing agent between two-layer; And comprise the combinative structure that is placed on the water absorbing agent between the hydrophilic fibers layer; With comprise that one deck passes through the combinative structure with the water absorbing agent layer of the water of specified quantitative and water absorbing agent be combined into shape.The adsorbing material combinative structure is not limited to above-mentioned example.
The water absorbing agent that preferably is used for adsorbing material is any one of following water absorbing agent: the adsorption capacity under the no-load condition is 30 (g/g) or higher, and the destruction adsorption capacity of the static state under the load condition (1) is 20 (g/g) or higher water absorbing agent; Adsorption capacity under the no-load condition is 30 (g/g) or higher, and the dynamic destruction adsorption capacity under the load condition is 20 (g/g) or higher water absorbing agent; Adsorption capacity under the no-load condition is 30 (g/g) or higher, and the static state under the load condition to destroy adsorption capacity (4) be 30 (g/g) or higher water absorbing agent because these water absorbing agents can improve adsorbing material absorbability in actual applications.
It is preferred that to use the adsorption capacity under the no-load condition be 30 (g/g) or higher, and the static state under the load condition to destroy adsorption capacity (1) be that the reason of 20 (g/g) or higher water absorbing agent is as follows.If be less than 30 (g/g) in non-loaded down adsorption capacity, then absorbability is insufficient, and situations such as leakage take place easily, particularly is used in when comprising adsorbing material and having in the absorbent articles of high resin concentration when water absorbing agent.Adsorption capacity under non-loaded preferably is at least 33 (g/g), more preferably is at least 35 (g/g).In addition, if destroying adsorption capacity (1), the static state under load condition is lower than 20g/g, then similarly, the absorbability of absorbent articles is insufficient, situations such as leakage are easy to take place, or therefore absorption behavior can't obtain stable absorption property owing to significantly change such as treating factor such as variation that adsorptive liquid is formed.Static state under load condition is destroyed adsorption capacity (1) and is preferably 23 (g/g) or more.
Preferably using the adsorption capacity under no-load condition is 30 (g/g) or higher, and the dynamic destruction adsorption capacity under load condition is that the reason of 20 (g/g) or higher water absorbing agent is as follows.If be less than 30 (g/g) in non-loaded down adsorption capacity, absorbability is insufficient, and situations such as leakage take place easily, particularly is used in when comprising adsorbing material and having in the absorbent articles of high resin concentration when water absorbing agent.Adsorption capacity under non-loaded preferably is at least 33 (g/g), more preferably is at least 35 (g/g).In addition, if the dynamic destruction adsorption capacity under load condition is lower than 20 (g/g), then similarly, the absorbability of absorbent articles is insufficient, situations such as leakage are easy to take place, or its absorption behavior is owing to such as treating the variation that adsorptive liquid is formed and putting on factor such as dynamic force on the resin and significantly change, therefore can't obtain stable absorption property.Dynamic destruction adsorption capacity under load condition is preferably 23 (g/g) or more.
Preferably using the adsorption capacity under no-load condition is 30 (g/g) or higher, and the static state under load condition to destroy adsorption capacity (4) be that the reason of 30 (g/g) or higher water absorbing agent is as follows.If be less than 30 (g/g) in non-loaded down adsorption capacity, then absorbability is insufficient, and situations such as leakage take place easily, particularly is used in when comprising adsorbing material and having in the absorbent articles of high resin concentration when water absorbing agent.Adsorption capacity under non-loaded preferably is at least 33 (g/g), more preferably is at least 35 (g/g).In addition, if destroying adsorption capacity (4), the static state under load condition is lower than 30g/g, then similarly, the absorbability of absorbent articles is insufficient, situations such as leakage are easy to take place, or therefore absorption behavior can't obtain stable absorption property owing to significantly change such as treating factor such as variation that adsorptive liquid is formed.Static state under load condition is destroyed adsorption capacity (4) and preferably is at least 32 (g/g), more preferably is at least 34 (g/g).
The example of above-mentioned fiber base material comprises hydrophilic fibers, for example: and cellulose fibre, as groundwood pulp, chemical wood pulp, half chemical wood pulp, the digestion wood pulp that from timber, obtains; And man-made cellulose fibers, for example artificial silk, acetate fiber.In the above-mentioned fiber of enumerating, cellulose fibre is preferred.Described in addition hydrophilic fibers can comprise such as polyamide, polyester and polyolefinic synthetic fibers.Fiber base material is not limited to the above-mentioned fiber that exemplifies.If fiber base material is made such as the sheet material that fills up or net, or made ribbon, then it is easy to be used as following adsorption layer.
In addition, under such as the less relatively situation of the ratio of fibrous material in adsorbing material of hydrophilic fibers, can be with binding agent with adsorbing material, promptly hydrophilic fibers bonds together.If hydrophilic fibers bonds together, intensity and the shape retention of adsorbing material before using or in the use can will be improved.
The example of above-mentioned binding agent comprises: heat sealable fiber, for example polyolefine fiber (for example polyethylene, polypropylene, ethylene-propylene copolymer, 1-butylene-ethylene copolymer); With the bonding emulsion.These binding agents can use the use that also can be bonded to each other alone.The weight rate of hydrophilic fibers and binding agent is preferably within 50/50 to 99/1 scope, more preferably within 70/30 to 95/5 scope, further preferably within 80/20 to 95/5 scope.
Comprise that the adsorbing material of the invention described above water absorbing agent preferably satisfies the static state destruction concentration adsorption exponent of equation (1):
Static concentration adsorption exponent=X (1-the α)+Y α that destroys〉23 (1) wherein: X is the adsorption capacity (g/g) of water absorbing agent under no-load condition;
Y is that the static state of water absorbing agent under load condition is destroyed adsorption capacity (1) (g/g);
α is the weight ratio (α〉0.4) of water absorbing agent and water absorbing agent and fiber base material gross weight.
Static in the present invention destruction concentration adsorption exponent is following summation:
The weight rate of fiber base material is long-pending in the adsorption capacity X (g/g) of water absorbing agent under no-load condition and the adsorbing material;
Water absorbing agent destroys weight rate long-pending of adsorption capacity (1) Y (g/g) and water absorbing agent in adsorbing material in the static state under the load condition.
The described static concentration adsorption exponent that destroys is the newfound index as prediction adsorbing material absorbability in actual applications of the inventor.
If suitably select the weight ratio α of the gross weight of water absorbing agent and water absorbing agent and fiber base material with water absorbing agent, make that the static state destruction concentration adsorption exponent of above-mentioned equation (1) is 23 or more, the adsorbing material that then obtains can be improved near the adsorbance under the actual state that uses.And, if select some water absorbing agents like this, their adsorption capacities under no-load condition are X (g/g), it is Y (g/g) that static state under load condition is destroyed adsorption capacity (1), provide same static state each other and destroy concentration adsorption exponent value, then can produce the adsorbing material that under state, has almost same adsorbance each other, even their adsorption capacity value differs from one another near actual use.In addition, as previously mentioned, in the present invention, it is a value of being measured by specific new evaluation methodology that the static state under load condition is destroyed adsorption capacity (1).As previously mentioned, have a lot of prior art files to disclose the mensuration of the adsorption capacity under load, measurement wherein generally is to carry out in the short relatively time with the liquid that a kind of electrolyte concentration is similar to urine.Yet under many circumstances, the actual of diaper worn for up to 6 hours or more.Therefore the water-absorbing resin (water absorbing agent) that has excellent results in above-mentioned recommended common assessment item might not also have good performance in actual use.In addition, the chemical compound that comprises in the urine can change the performance of (destruction) resin as time passes, and the existence of these chemical compounds also greatly influences water absorbing agent absorption behavior in actual applications.In addition, the inventor points out that clearly the importance of these performances changes along with the weight ratio α of the gross weight of water absorbing agent and water absorbing agent and fiber base material.That is to say that the diaper that only improve in the adsorption capacity under the load condition and can't improve adsorbing material, for example comprises fiber base material is near the adsorbance under the state of actual user mode.For realizing this improvement, need correct selection resin, so that the defined static concentration adsorption exponent that destroys reaches 23 or bigger among the present invention.
For adsorbing material of the present invention, with diminishing gradually of the weight ratio α of the gross weight of water absorbing agent and water absorbing agent and fiber base material, for operable water absorbing agent, adsorption capacity X under no-load condition becomes more important, but consider the static concentration adsorption exponent value of destroying, the higher resin of value that the static state under load condition is destroyed adsorption capacity (1) Y also can use.In addition, change gradually with α is big, and for operable water absorbing agent, the static state under load condition is destroyed adsorption capacity (1) Y and become more important, but consider the static concentration adsorption exponent value of destroying, the higher resin of the numerical value of the adsorption capacity X under no-load condition also can use.Preferably when α be 0.4 or more for a long time, effect of the present invention can significantly show.More preferably α is 0.6 or higher.α less than 0.4 situation under, the difference of the physical property of some water absorbing agents can not be reflected in to same degree performance not the same of adsorbing material.
In the present invention, suitably determine the weight ratio α of water absorbing agent and the gross weight of water absorbing agent and fiber base material to make that the static state destruction concentration adsorption exponent of equation (1) is 23 or more with water absorbing agent.Destroy the concentration adsorption exponent in static state and be less than under 23 the situation, adsorbing material low near the adsorbance under the state of actual user mode: for example, in comprising the diaper of adsorbing material, it is higher that the probability that leaks takes place.Preferred static destruction concentration adsorption exponent value is 26 or higher.
In addition, even static destruction concentration adsorption exponent value is 23 or higher, the use amount of water absorbing agent still is preferably 8 (g) or more.The quantity of use water absorbing agent is less than the absorbent articles of 8 (g), may lack dry and comfortable sensation, and the bigger absorption of separating is arranged.The use amount of water absorbing agent is 10～20 (g) more preferably.In addition, the basic weight of water absorbing agent is preferably 100 (g/m in the adsorbing material 2) or more.
Comprise that the adsorbing material of the invention described above water absorbing agent also preferably satisfies the dynamic destruction concentration adsorption exponent of equation (2):
Dynamically destroy concentration adsorption exponent=X (1-γ)+A γ〉23 (2) wherein: X is the adsorption capacity (g/g) of water absorbing agent under no-load condition;
A is the dynamic destruction adsorption capacity (g/g) of water absorbing agent under load condition;
γ is the weight ratio (γ〉0.4) of water absorbing agent and water absorbing agent and fiber base material gross weight.
Dynamically destroying the concentration adsorption exponent in the present invention is following summation:
The weight rate of fiber base material is long-pending in the adsorption capacity X (g/g) of water absorbing agent under no-load condition and the adsorbing material;
Water absorbing agent is long-pending the weight rate of the dynamic destruction adsorption capacity A (g/g) under the load condition and water absorbing agent in adsorbing material.
Described dynamic destruction concentration adsorption exponent is that the inventor is newfound as the exponential yardstick of prediction adsorbing material absorbability in actual applications.
If suitably select the weight ratio γ of the gross weight of water absorbing agent and water absorbing agent and fiber base material with water absorbing agent, make that the dynamic destruction concentration adsorption exponent of above-mentioned equation (2) is 23 or more, the adsorbing material that then obtains can be improved near the adsorbance under the actual state that uses.And, if select some water absorbing agents like this, their adsorption capacities under no-load condition are X (g/g), dynamic destruction adsorption capacity under load condition is A (g/g), provide same dynamic destruction concentration adsorption exponent value each other, then can produce the adsorbing material that under state, has almost same adsorbance each other, even their adsorption capacity value differs from one another near actual use.In addition as previously mentioned, the dynamic destruction adsorption capacity under load condition is a value of being measured by specific new evaluation methodology in the present invention.As previously mentioned, have a lot of prior art files to disclose the mensuration of the adsorption capacity under load, measurement wherein generally is to carry out in the short relatively time with the liquid that a kind of electrolyte concentration is similar to urine.Yet under many circumstances, the actual of diaper worn for up to 6 hours or more.Therefore the water-absorbing resin (water absorbing agent) that has excellent results at above-mentioned recommended common assessment item might not also have good performance in actual use.In addition, the chemical compound that comprises in the urine can change the performance of (destruction) resin as time passes, and the existence of these chemical compounds also greatly influences water absorbing agent absorption behavior in actual applications.In addition, because user moves in actual use, so dynamic force also can apply effect to resin.In addition, the inventor points out that clearly the importance of these performances changes along with the weight ratio γ of the gross weight of water absorbing agent and water absorbing agent and fiber base material.That is to say that the diaper that only improve in the adsorption capacity under the load condition and can't improve adsorbing material, for example comprises fiber base material is near the adsorbance under the state of actual user mode.For realizing this improvement, need the correct resin of selecting, so that defined dynamic destruction concentration adsorption exponent reaches 23 or bigger among the present invention.
For adsorbing material of the present invention, with diminishing gradually of the weight ratio γ of the gross weight of water absorbing agent and water absorbing agent and fiber base material, for operable water absorbing agent, adsorption capacity X under no-load condition becomes more important, but consider dynamic destruction concentration adsorption exponent value, the higher resin of value of the dynamic destruction adsorption capacity A under load condition also can use.In addition, change gradually with γ is big, and for operable water absorbing agent, the dynamic destruction adsorption capacity A under load condition becomes more important, but consider dynamic destruction concentration adsorption exponent value, the higher resin of the numerical value of the adsorption capacity X under no-load condition also can use.Preferably when γ be 0.4 or more for a long time, effect of the present invention can significantly show.More preferably γ is 0.6 or higher.γ less than 0.4 situation under, the difference of the physical property of water absorbing agent can not be reflected in to same degree performance not the same of adsorbing material.
In the present invention, suitably determine the weight ratio γ of the gross weight of water absorbing agent and water absorbing agent and fiber base material to make that the dynamic destruction concentration adsorption exponent of equation (2) is 23 or more with water absorbing agent.Be less than under 23 the situation dynamically destroying the concentration adsorption exponent, adsorbing material be low near the adsorbance under the state of actual user mode: for example, in comprising the diaper of adsorbing material, it is higher that the probability that leaks takes place.Preferred dynamically destruction concentration adsorption exponent value is 26 or higher.
In addition, be 23 or higher even dynamically destroy concentration adsorption exponent value, the use amount of water absorbing agent still is preferably 8 (g) or more.The quantity of use water absorbing agent is less than the absorbent articles of 8 (g), may lack dry and comfortable sensation, and the bigger absorption of separating is arranged.The use amount of water absorbing agent is 10～20 (g) more preferably.The basic weight of water absorbing agent is preferably 100 (g/m in the adsorbing material in addition 2) or more.
Because the front illustrates that the water absorbing agent that is used for adsorbing material of the present invention preferably has the hydrotrope content of the adsorption rate and 1～15% (weight) of 20～80 (seconds) when setting forth water absorbing agent.
In addition, can be by in above-mentioned adsorbing material, adding various materials, for example deodorizer, spice, various inorganic material powders, foaming agent, pigment, dyestuff, hydrophilic short fiber, fertilizer, oxidant, Reducing agent, water and salt, and make adsorbing material or goods have various functions.
(absorbent articles 〉
The invention described above water absorbing agent can be used for absorbent articles.This absorbent articles comprises that one comprises the adsorption layer of adsorbing material, the backing layer that has the surface layer of liquid permeable and have the liquid impenetrability.Described adsorption layer is placed on the surface layer with liquid permeable and has between the backing layer of liquid impenetrability.Because described absorbent articles comprises the adsorption layer of the adsorbing material with combinations thereof structure, described absorbent articles has above-mentioned good water absorbing properties.The example of concrete absorbent articles comprises hygienic article, and for example diaper, sanitary towel and so-called incontinence are used and filled up, but to the not special restriction of absorbent articles.Because absorbent articles has good water absorbing properties, so it can prevent that urine from leaking, and be under the situation of (for example) diaper at absorbent articles, so-called dry and comfortable sensation is provided.If desired, allow with one deck help liquid dispersion and (for example) comprise the dispersion layer of adhesive-bonded fabric, cellulose or cross-linked cellulose be placed on adsorption layer above, the back side of surface layer or above.
If have aforesaid adsorbing material, the combinative structure of adsorption layer is had no particular limits.Also there is no particular limitation to the technology of producing adsorption layer in addition.And adsorption layer is placed on method between fluid permeable lamella and the impermeable lamella of liquid, and the process of promptly producing absorbent articles does not have special qualification yet.
The adsorbing material that is included in the adsorption layer comprises aforementioned water absorbing agent of the present invention and fiber base material.Explanation about material usage separately, combinative structure, weight ratio and other performance of water absorbing agent and fiber base material is omitted in this part of description, because they are the same with aforementioned explanation in adsorbing material.
Above-mentioned lamella (being called the fluid permeable sheet later on) with liquid permeable comprises the permeable material of water fluid.The example that this class constitutes the material of fluid permeable sheet comprises: adhesive-bonded fabric, yarn fabric; The porous synthetic resin thin film of polyethylene, polypropylene, polyester, polyamide.Above-mentioned lamella (being called impermeable of liquid later on) with liquid impenetrability comprises the impermeable material of water fluid.The example that this class constitutes the material of impermeable of liquid comprises: the film of synthetic resin of polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polrvinyl chloride; The laminated film of above-mentioned synthetic resin and adhesive-bonded fabric; The laminated film of above-mentioned synthetic resin and yarn fabric.In addition, impermeable of liquid can be vapor permeable.
In addition, can be by in above-mentioned adsorbing material, adding various materials, for example deodorizer, spice, various inorganic material powders, foaming agent, pigment, dyestuff, hydrophilic short fiber, fertilizer, oxidant, Reducing agent, water and salt, and make adsorbing material or goods have various functions.
The adsorption capacity that absorbent articles of the present invention is included under the no-load condition is 30 (g/g) or more, approximate adsorption capacity (2) under load condition is 20 (g/g) or more water absorbing agent, and the approximate concentration adsorption exponent of this absorbent articles is 23 or higher, wherein, the adsorption capacity of water absorbing agent is represented with X (g/g) under no-load condition, the approximate adsorption capacity (2) of water absorbing agent is represented with Z (g/g) under load condition, when the weight ratio of water absorbing agent and water absorbing agent and fiber base material gross weight was represented with β, the approximate concentration adsorption exponent was provided by following equation (2):
Approximate concentration adsorption exponent=X (1-β)+Z β (2)
Approximate concentration adsorption exponent of the present invention be down train value and: water absorbing agent is at the adsorption capacity X under the no-load condition (g/g), water absorbing agent approximate adsorption capacity (2) Z (g/g) under load condition, with the product of its specific ratios separately, this specific ratios is derived by the weight ratio β of water absorbing agent and water absorbing agent and fiber base material gross weight.
If suitably select the weight ratio β of the gross weight of water absorbing agent and water absorbing agent and fiber base material with water absorbing agent, make that the approximate concentration adsorption exponent of above-mentioned equation (2) is 23 or more, the absorbent articles that then obtains can be improved near the adsorbance under the actual state that uses.And, if select some water absorbing agents like this, their adsorption capacities under no-load condition are X (g/g), approximate adsorption capacity (2) under load condition is Z (g/g), provide same approximate concentration adsorption exponent value each other, then can produce the absorbent articles that under state, has almost same adsorbance each other, even their adsorption capacity value differs from one another near actual use.In addition as previously mentioned, approximate adsorption capacity (2) requirement under load condition in the present invention is a value of being measured by specific new evaluation methodology.As previously mentioned, have a lot of prior art files to disclose the mensuration of the adsorption capacity under load, measurement wherein generally is to carry out in the short relatively time with the liquid that a kind of electrolyte concentration is similar to urine.Yet under many circumstances, the actual of diaper worn for up to 6 hours or more.Therefore the water-absorbing resin (water absorbing agent) that has excellent results at above-mentioned recommended common assessment item might not also have good performance in actual use.In addition, the inventor points out that clearly the importance of these performances changes along with the weight ratio β of the gross weight of water absorbing agent and water absorbing agent and fiber base material.That is to say that the diaper that only improve in the adsorption capacity under the load condition and can't improve absorbent articles, for example comprises fiber base material is near the adsorbance under the state of actual user mode.For realizing this improvement, need correctly to select resin, so that defined approximate concentration adsorption exponent is within the scope of the invention among the present invention.
The weight ratio that comprises the gross weight of water absorbing agent and water absorbing agent and fiber base material in the absorbent articles of the present invention is the adsorbing material of β, when β hour, for operable water absorbing agent, adsorption capacity X under no-load condition becomes more important, but consider approximate concentration adsorption exponent value, also can use the higher resin of value of approximate adsorption capacity (2) Z under load condition.In addition, when β was big, for operable water absorbing agent, approximate adsorption capacity (2) Z under load condition became more important, but consider approximate concentration adsorption exponent value, also can use the higher resin of numerical value of the adsorption capacity X under no-load condition.Preferably when β be 0.4 or more for a long time, effect of the present invention can significantly show.More preferably β is 0.6 or higher.β less than 0.4 situation under, the difference of the physical property of water absorbing agent can not be reflected in to same degree on the difference of performance of absorbent articles.
In the present invention, suitably determine the weight ratio β of the gross weight of water absorbing agent and water absorbing agent and fiber base material, make that the approximate concentration adsorption exponent of equation (2) is 23 or more.Be less than at the approximate concentration adsorption exponent under 23 the situation, absorbent articles be low near the adsorbance under the state of actual user mode, and when absorbent articles be for example during diaper, the probability that leakage takes place is higher.Preferred approximate concentration adsorption exponent value is 26 or higher.
In addition, even approximate concentration adsorption exponent value is 23 or higher, the use amount of water absorbing agent still is preferably 8 (g) or more.The quantity of use water absorbing agent is less than the absorbent articles of 8 (g), may lack dry and comfortable sensation, and the bigger absorption of separating is arranged.The use amount of water absorbing agent is 10～20 (g) more preferably.The basic weight of water absorbing agent is preferably 100 (g/m in the adsorbing material in addition 2) or more.
The absorbent articles of the invention described above can be produced at an easy rate with water absorbing agent of the present invention, this water absorbing agent satisfies aforesaid parameter, and for example the adsorption capacity under no-load condition, the destruction adsorption capacity under load condition, the destruction under load condition are sheared adsorption capacity and the approximate adsorption capacity under load condition.
In addition, as for absorbent articles of the present invention, the adsorption layer that comprises described adsorbing material is placed on the surface layer with liquid permeable and has between the backing layer of liquid impenetrability, but one deck can be helped liquid dispersion and (for example) comprise the dispersion layer of adhesive-bonded fabric, cellulose or cross-linked cellulose be placed on adsorption layer above, the back side of surface layer or above.
Absorbent articles of the present invention comprises adsorption layer, and this adsorption layer comprises the adsorbing material with combinations thereof structure, and is placed between fluid permeable lamella and the impermeable lamella of liquid.Because described absorbent articles comprises the adsorption layer of the adsorbing material with combinations thereof structure, so described absorbent articles has above-mentioned good water absorbing properties.The example of concrete absorbent articles comprises hygienic article, and for example diaper, sanitary towel and so-called incontinence are used and filled up, but to the not special restriction of absorbent articles.Because absorbent articles has good water absorbing properties, so it can prevent that urine from leaking, and be under the situation of for example diaper at absorbent articles, so-called dry and comfortable sensation is provided.
Above-mentioned lamella (being called the fluid permeable sheet later on) with liquid permeable comprises the permeable material of water fluid.The example that this class constitutes the material of fluid permeable sheet comprises: adhesive-bonded fabric, yarn fabric; The porous synthetic resin thin film of polyethylene, polypropylene, polyester, polyamide.Above-mentioned lamella (being called impermeable of liquid later on) with liquid impenetrability comprises the impermeable material of water fluid.The example that this class constitutes the material of impermeable of liquid comprises: the film of synthetic resin of polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polrvinyl chloride; The laminated film of above-mentioned synthetic resin and adhesive-bonded fabric; The laminated film of above-mentioned synthetic resin and yarn fabric.In addition, impermeable of liquid can be vapor permeable.
If have above-mentioned adsorbing material, the combinative structure of adsorption layer is had no particular limits.Also there is no particular limitation to the technology of producing above-mentioned adsorption layer in addition.And to adsorption layer being placed on the method between impermeable of fluid permeable sheet and the liquid, the process of promptly producing absorbent articles does not have special qualification yet.
In addition, can be by in above-mentioned adsorbing material, adding various materials, for example deodorizer, spice, various inorganic material powders, foaming agent, pigment, dyestuff, hydrophilic short fiber, fertilizer, oxidant, Reducing agent, water and salt, and make adsorbing material or goods have various functions.
The measuring method of＜absorption property 〉
According to the present invention, the measuring method of absorption property is a kind of new evaluation methodology, it is characterized in that be selected from the program of at least a performance of following performance in measurement, a kind of liquid that comprises reducible material is used as liquid to be adsorbed: the absorption property of water absorbing agent under load condition; The weight ratio of the gross weight of water absorbing agent and water absorbing agent and fiber base material is 0.4 or the absorption property of more adsorbing material; And the absorption property that comprises the absorbent articles of above-mentioned adsorbing material.
The example of the reducible material of above-mentioned use comprises: the L-ascorbic acid; Ascorbate, for example L-sodium ascorbate; Arabo-ascorbic acid; Erythorbate; Sulfurous acid (hydrogen) salt, for example sodium sulfite and sodium sulfite; Reducible metal (or its salt), for example ferrous salt; And amine.L-ascorbic acid (or its salt) and arabo-ascorbic acid (or its salt) are preferred.The concentration of liquid that comprises reducible material is according to the kind of reducible material or according to the difference of the purpose of using and difference, but usually when for example the L-ascorbic acid is used as reducible material, the concentration of liquid is about 0.001～about 0.5% (weight).
If liquid to be adsorbed has comprised reducible material, described liquid is not particularly limited, but the example comprises artificial urine, physiological sodium chloride solution and people's urine.
Measuring condition as for the absorption property of water absorbing agent, adsorbing material and absorbent articles, preferably under such as 34～42 ℃ temperature, measure, be more preferably in 35～39 ℃ scope and carry out, and be in the presence of oxygen, to carry out, with prediction absorbent articles absorption behavior in actual applications.
The absorption property of the water absorbing agent of being measured by measuring method of the present invention comprises all absorption properties under load condition, and the example is included in adsorption capacity under the load condition and the liquid infiltration performance under load condition.The present invention is specially adapted to the mensuration of the adsorption capacity under load condition.
Except that adsorbing the step of the liquid that comprises reducible material, the condition of measurement adsorption capacity under load condition can be that those are disclosed in such as EP339,461, EP605,150, EP640,330 and EP712, the condition of adsorption capacity under the general measure load condition in 659 files such as grade and diffusion adsorption capacity is wherein to optimizing according to different test purposes with factors such as whether the liquid diffusion conditions are arranged such as the particle size of the weight of load-up condition, resin, resin.In a preferred embodiment, make described resin absorption comprise the liquid of reducible material, leave standstill certain hour then, preferred 1～12 hour, measure the adsorption capacity under load condition afterwards, because can judge absorption behavior in actual use more accurately like this.
The example of the measurement of liquid infiltration performance comprises the measurement of the gel permeance property under load condition that is disclosed among the WO95/26209 under load condition.
The absorption property of the adsorbing material of measuring according to measuring method of the present invention comprises all at the absorption property under the no-load condition and under load condition, the example comprises as being disclosed in WO95/26209, EP339,461 and EP712, the absorption property (adsorbance) of adsorbing material in 659 under load condition, with as be disclosed in EP761, adsorption rate or the wet back of the body (Wet Back) of adsorbing material under load condition in 241.
The absorption property of the absorbent articles of measuring according to measuring method of the present invention comprises all at the absorption property under the no-load condition and under load condition, the example comprises as being disclosed in EP339, the adsorption rate of the absorbent articles in 461 and adsorbance, with as be disclosed in EP712, the absorption property (adsorbance) of the absorbent articles in 659.
By measuring method of the present invention, no matter how liquid to be adsorbed changes, and water absorbing agent, adsorbing material and absorbent articles with stable always absorption behavior can be designed, select and pick out.Measuring method of the present invention in addition can be preferred for the quality management of the production aspect of water-absorbing resin.
＜effect of the present invention and advantage 〉
At adsorption capacity under the no-load condition and static under load condition or dynamically destroy the water absorbing agent that adsorption capacity satisfies the analog value that the present invention limits, it is all very stable and pass in time and change very little absorption property to have urine for any composition.Even therefore described water absorbing agent is applicable in the absorbent articles with high resin concentration.
Preferably by in water-absorbing resin, adding ion sealer and/or chelating agen in a particular manner, or in specific water-absorbing resin, add ion sealer and/or chelating agen and they are mixed, or in water-absorbing resin, add the chelating agen of ad hoc structure and obtain above-mentioned water absorbing agent, this water absorbing agent is subjected to the very little destruction of urine in time, and has excellent absorption property.
Absorbent articles of the present invention is by considering the static of resin concentration or dynamically destroying the concentration adsorption exponent and limit, described like this absorbent articles has stable always high adsorption capacity, particularly is being in close proximity to the high adsorption capacity before revealing under the state of actual user mode.
Absorption property measuring method of the present invention can be simply and is predicted water absorbing agent or the absorption behavior of absorbent articles under actual user mode exactly, so this method is particularly useful for water absorbing agent or absorbent articles that production has excellent absorption property.
＜detailed description of preferred embodiments 〉
Embodiment that below will be by certain preferred embodiments be not according to comparative example of the present invention to recently describing the present invention in further detail.But the present invention is not limited to these embodiment.By the way, the performance of water absorbing agent is measured by following method:
(a) adsorption capacity under the no-load condition:
At first 0.2g water absorbing agent (water-absorbing resin) is put into equably an adhesive-bonded fabric bag (60mm * 60mm), immerse then in the sodium-chloride water solution (physiological sodium chloride solution) of 0.9wt%.After 60 minutes, pull out sack, under 250G, dry 3 minutes with a centrifuge then, measure the weight W of bag then 1(g).On the other hand, carry out same process, measure the final weight W of bag without water absorbing agent 0(g).Like this, according to following formula by weight W 1And W 0Calculate the adsorption capacity (g/g) under the no-load condition:
Adsorption capacity (g/g)
={ (weight W 1(g)-weight W 0(g))/(weight of water absorbing agent (g) }-1
(b) adsorption capacity under load condition
According to the resistance to compression absorption of EDANA, absorption III 442.1-99 (October, 1997) (ABSORBENCY AGAINST PRESSURE, ABSORBENCY III 442.1-99 (℃ tober 1997) of EDANA) is at 50g/cm 2Load measure down adsorption capacity under load.That is to say that the water absorbing agent (water-absorbing resin) of 0.9g is dispersed in 400 purpose stainless steel metals online (width of mesh: 38 microns), and described stainless steel wire mesh fusion is connected the bottom that internal diameter is the plasticity support cylinder tube of 60mm.Then a piston (cover plate) (its external diameter is slightly smaller than 60mm, and does not have the gap with the wall surface of described support cylinder tube, does not move up and down but do not hinder) is added on the water absorbing agent, measures the gross weight (Wa (g)) of support cylinder tube, water absorbing agent and piston.To can on water absorbing agent, evenly apply 50g/cm through regulating then 2The weight of load (weight that comprises piston) is added on the described piston, constitutes a cover measuring device thus.With diameter is that the glass filter of 90mm is placed in the Petri culture dish that diameter is 150mm, the sodium-chloride water solution of 0.9wt% is added to the height same with the upper surface of glass filter, place the filter paper that diameter is 9cm (by No. 2 filter paper of Toyo filter paper company limited manufacturing) then thereon, its whole surface will be soaked like this, removes excess liquid.
Above-mentioned a whole set of measuring device is placed on the above-mentioned wet filter paper, makes water absorbing agent adsorptive liquid under load condition thus.After liquid level had dropped under the glass filter top, adding liquid was constant to keep liquid level.After one hour, after lifting a whole set of measuring device and removing weight, measure weight (Wb (g)) (gross weight of support cylinder tube, swollen water absorbing agent and piston) once more.Calculate adsorption capacity (g/g) under load condition according to following formula by above-mentioned weight W a and Wb thus:
Adsorption capacity under load condition (g/g)=
(Wb (g)-Wa (g))/(weight of water absorbing agent) is (g).
(c) static state under load condition is destroyed adsorption capacity (1):
Utilize the static state of measuring under load condition with the identical measuring device described in the top adsorption capacity project under load condition to destroy adsorption capacity (1).Measuring process will be described below.At first, the water absorbing agent (water-absorbing resin) of 0.9g is dispersed in the described support cylinder tube, that is, on 400 purpose stainless (steel) wires, the weight that adds behind the above piston (cover plate) is designated as W 1(g).The sodium-chloride water solution of 0.9wt% of 13.5g that will comprise concentration and be the L-ascorbic acid of 0.005wt% joins in the Petri culture dish that diameter is 90mm, to there be described water-absorbing resin its bottom metal that distributes online and do not have the support cylinder tube of load to be added on the described Petri culture dish then, make resin in the Petri culture dish, evenly adsorb the 0.9wt% sodium-chloride water solution that comprises 0.005wt% concentration L-ascorbic acid thus, and formation is swelling to 15 times gel thus, leaves standstill 6 hours under 37 ℃ then.
After 6 hours, above-mentioned piston (cover plate) and be adjusted to and can evenly apply 50g/cm 2The weight that is carried on above-mentioned swollen water absorbing agent, be added in order on the described swollen water absorbing agent.The glass filter that with diameter is 90mm then is placed in the Petri culture dish that diameter is 150mm, the sodium-chloride water solution of 0.9wt% is added to surperficial same height with glass filter, place the filter paper that diameter is 9cm (by No. 2 filter paper of Toyo filter paper company limited manufacturing) then thereon, its whole surface will be soaked like this, removes excess liquid.
Then, be placed on the above-mentioned wet filter paper being swelling to a whole set of measuring device of exerting pressure on 15 times the gel, make gel adsorptive liquid under load condition thus above-mentioned.Dropped under the top of glass filter at liquid level after, it is constant to keep liquid level to add liquid.After one hour, lift a whole set of measuring device and remove, shed weight, measure last weight (W2 (g)) once more from filter paper.Destroy adsorption capacity (1) according to following formula by the static state that above-mentioned weight W 1 and W2 calculate under load condition thus:
Static state under load condition destroy adsorption capacity (1) (g/g)=
(W2 (g)-W1 (g))/(weight of water absorbing agent) (g).
(d) static state under load condition is destroyed adsorption capacity (2)
Destroy adsorption capacity (2) in the static state under the load condition and calculate, changed 2 hours into by 6 hours but be swelling to 15 times gel time of repose to destroy mode identical in the measurement of adsorption capacity (1) with above-mentioned static state under load condition.
(e) static state under load condition is destroyed adsorption capacity (3):
Destroy adsorption capacity (3) in the static state under the load condition and calculate, but the concentration of the L-ascorbic acid in the physiological sodium chloride solution changes 0.05wt% into by 0.005wt% to destroy mode identical in the measurement of adsorption capacity (2) with above-mentioned static state under load condition.
(f) static state under load condition is destroyed adsorption capacity (4):
Destroying adsorption capacity (4) in the static state under the load condition calculates to destroy mode identical in the measurement of adsorption capacity (1) with above-mentioned static state under load condition, but the concentration of the L-ascorbic acid in the physiological sodium chloride solution changes 0.05wt% into by 0.005wt%, and evenly is applied to load on the water absorbing agent by 50g/cm 2Change 20g/cm into 2
(g) the dynamic destruction adsorption capacity under load condition:
At first 0.9g water absorbing agent (water-absorbing resin) is put into the Polythene Bag of a 5cm * 10cm, to the L-dissolution of ascorbic acid be gone into the solution that (wt% is based on the weight of solution) makes in the sodium-chloride water solution of 0.9wt% with 0.005wt% concentration then adds in the bag, prepared like this and be swelling to 15 times gel, sealed bag then.The product of the sealing that obtains was kept 4 hours under 37 ℃ temperature.Then the air in the sack is extracted.Sealed bag is once more dynamically destroyed gel along sack with the roller (diameter 9cm, width 20cm) of 5 kilogram weights, described roller with each back and forth 5 seconds speed move back and forth 50 times.
To carry out dynamic destructive gel and take out sack with said method, use then with the identical measuring device described in the above-mentioned project in adsorption capacity under the load condition (b) and measure the adsorption capacity of above-mentioned gel under load, The ultimate results is regarded as the dynamic destruction adsorption capacity under the load condition.Described measuring process is as follows: with above-mentioned being dispersed in the described support cylinder tube through dynamic destructive gel of taking out from sack, that is, it is online to be dispersed in 400 purpose stainless steel metals, measures the gross weight (W that adds behind the above piston (cover plate) A(g)).To can evenly apply 50g/cm through overregulating then 2Load (weight that comprises described piston) be added on the described piston in the weight on the gel.Then, with diameter is that the glass filter of 90mm is placed in the Petri culture dish that diameter is 150mm, the sodium-chloride water solution of 0.9wt% is added to surperficial same height with glass filter, place the filter paper that diameter is 9cm (by No. 2 filter paper of Toyo filter paper company limited manufacturing) then thereon, its whole surface will be soaked like this, removes excess liquid.
Then, be placed on the above-mentioned wet filter paper being swelling to a whole set of measuring device of exerting pressure on 15 times the gel, make gel adsorptive liquid under load condition thus above-mentioned.Dropped under the top of glass filter at liquid level after, it is constant to keep liquid level to add liquid.After one hour, lift a whole set of measuring device and remove, shed weight, measure last weight (W once more from filter paper B(g)).Thus according to following formula by above-mentioned weight W AAnd W BCalculate the dynamic destruction adsorption capacity under load condition:
Dynamic destruction adsorption capacity (g/g) under load condition=
(W B(g)-W A(g)+13.5) g/ (weight of water absorbing agent) (g).
(h) dynamic adsorption capacity under load condition:
The dynamic adsorption capacity under the load condition with the measurement (g) of dynamic destruction adsorption capacity under load condition in identical mode, by above-mentioned weight W AAnd W BCalculate according to following formula, but the sodium-chloride water solution (wt% is based on the weight of solution) with the 0.9wt% that does not contain the L-ascorbic acid is used as making the swollen solution of described water absorbing agent before dynamically destroying, and described
The sealed product that is swelling to 15 times gel kept 30 minutes down at 37 ℃.
Dynamic adsorption capacity under load condition (g/g)=
(W B(g)-W A(g)+13.5) g/ (weight of water absorbing agent) (g).
(i) the approximate adsorption capacity (1) under load condition
Utilize and the identical approximate adsorption capacity (1) of measuring device measurement under load condition described in the top adsorption capacity project under load condition.Measuring process is described below.At first, the water absorbing agent (water-absorbing resin) of 0.9g is dispersed in the described support cylinder tube, promptly online at 400 purpose stainless steel metals, the weight that adds behind the above piston (cover plate) is designated as W 1(g).The sodium-chloride water solution of the 0.9wt% of 13.5g is joined in the Petri culture dish that diameter is 90mm, it is online and do not have the support cylinder tube of load to be added on the described Petri culture dish to have described water-absorbing resin to be distributed in its bottom metal then, make resin in the Petri culture dish, adsorb the sodium-chloride water solution of 0.9wt% equably thus, and formation is swelling to 15 times gel thus, leaves standstill 2 hours under 37 ℃ then.
After 2 hours, above-mentioned piston (cover plate) and be adjusted to and can evenly apply 50g/cm 2The weight that is carried on above-mentioned swollen water absorbing agent, be added in order on the described swollen water absorbing agent.The glass filter that with diameter is 90mm then is placed in the Petri culture dish that diameter is 150mm, the sodium-chloride water solution of 0.9wt% is added to surperficial same height with glass filter, place the filter paper that diameter is 9cm (by No. 2 filter paper of Toyo filter paper company limited manufacturing) then thereon, its whole surface will be soaked like this, removes excess liquid.
Then, be placed on the above-mentioned wet filter paper being swelling to a whole set of measuring device of exerting pressure on 15 times the gel, make gel adsorptive liquid under load condition thus above-mentioned.Dropped under the top of glass filter at liquid level after, add liquid to keep the liquid level constant height.After one hour, pick up a whole set of measuring device and remove, shed weight, measure last weight (W2 (g)) once more from filter paper.Calculate approximate adsorption capacity (1) under load condition according to following formula by above-mentioned weight W 1 and W2 thus:
Approximate adsorption capacity (1) under load condition (g/g)=
(W2 (g)-W1 (g))/(weight of water absorbing agent) (g).
(j) the approximate adsorption capacity (2) under load condition
With calculating approximate adsorption capacity (2) under load condition in the identical mode of the measurement of approximate adsorption capacity (1) under the load condition, changed 6 hours into by 2 hours but be swelling to 15 times gel time of repose with above-mentioned.
(k) adsorption rate:
Measure adsorption rate according to JIS K7224.Measuring process is described below.At first will transfer to 30 ℃ 50.0g physiological sodium chloride solution (0.9% sodium-chloride water solution) and stirs bar magnet (its central diameter is 8mm, diameter is 7mm, length is 30mm, and apply with fluororesin) put into the beaker of 100ml, be flat by JIS R3503 regulation at the bottom of the beaker, stir with the speed of magnetic stirrer then with 600rpm.Water absorbing agent with 2g joins in the beaker then, and owing to the water absorption and swelling effect causes gelling, when the flowability reduction, the vortex of the water of final mixing center disappears, and promptly when the stirring bar magnet begins can't see, is considered to reach terminal point.Measurement is by adding sample until the time that vortex disappears, and is considered as adsorption rate.
(1) hydrotrope content:
At first the water-absorbing resin with 0.500g is distributed in the deionized water of 1000ml, and stirs 16 hours, filters with filter paper then.Then, the beaker with the 50g in the filtrate that obtains puts into 100ml adds the 0.1N sodium hydrate aqueous solution of 1ml, N/200 Propylene Glycol chitosan aqueous solution and 4 0.1wt% toluidine blue aqueous solutions of 10.00ml in this filtrate.Subsequently, the final solution in the described beaker carries out colloidal titration with the polyvinyl potassium sulfate solution of N/400, supposes that the amount when solution becomes aubergine by blue stain is titrating terminal point, to determine titer Y (ml).In addition in the same manner as described above, but the filtrate of described 50g substitutes by the deionized water of 50g, determines titer Z (ml) by blank titration.Then by titer Y and Z, and the acrylic acid neutralization ratio W (mol%) that is used to produce water-absorbing resin, calculate hydrotrope content (wt%) according to following formula:
Hydrotrope content (wt%)=
(Z(ml)-Y(ml))×0.01×72×(100-W(mol％))+(94W(mol％)/100).
(m) water content (wet basis):
The water-absorbing resin of about 1g was heated 3 hours in 105 ℃ baking oven, before and after heating, measures the weight W (g) of described water-absorbing resin respectively, calculate water content (wet basis) according to following formula:
Water content (wt%)=(W Before the heating(g)-W After the heating(g))/W Before the heating(g) wherein: W Before the heating(g) be the weight of described water-absorbing resin before oven dry;
W After the heating(g) be the weight of described water-absorbing resin after oven dry.
Embodiment 1
By 9.25g polyethyleneglycol diacrylate (average mol of the ethylene oxide of addition is 8) is dissolved in 5, the 500g neutralization ratio is the sodium acrylate aqueous solution (monomer concentration: make reaction solution 30wt%) of 65mol%.This solution outgased 30 minutes under blanket of nitrogen then, joined afterwards in the reactor, and this reactor is the both arms type kneader that has the rustless steel of lid to make, and volume is 10 liters, has two sigma shape blades and a chuck.Keep described reaction solution, the air nitrogen replacement of internal system down at 30 ℃.Under the situation that stirs described reaction solution, add 1.91g 2,2 then, the L-ascorbic acid of-azo two (2-amidine propane) dihydrochloride, 0.96g sodium peroxydisulfate and 0.10g begins polyreaction after general like this 1 minute.Described polyreaction is carried out under 30-80 ℃ temperature, and after polymerization begins 60 minutes the aquogel polymer that obtains is taken out.
Described final aquogel polymer has the diameter of about 5mm.With this dispersive aquogel polymer be dispersed in 50 purposes online and at 150 ℃ with hot-air dry 90 minutes.Then the desciccate that obtains is pulverized with vibromill, and, obtained to grind to form the precursor that erose average particulate diameter is the water-absorbing resin of 300 μ m (a) thus with the further classification of 20 purpose screen clothes.
A kind of surface crosslinking agent, comprising 0.005 part of (weight) diethylene-triamine pentaacetic acid five sodium, 1 part of (weight) propylene glycol, 0.05 part of (weight) Ethylene glycol diglycidyl ether, 3 parts of (weight) water and 1 part of (weight) isopropyl alcohol, mix with the water-absorbing resin precursor (a) that 100 parts (weight) as above obtain.The mixture that obtains was heated 45 minutes under 210 ° of C, obtain water absorbing agent (1) thus, the measurement result of its following performance is recorded in the table 1: the adsorption capacity under no-load condition, adsorption capacity under load condition, static state under load condition is destroyed adsorption capacity (1)～(4), dynamic adsorption capacity under load condition, dynamic destruction adsorption capacity under load condition, approximate adsorption capacity (1)～(2) under load condition, the content of the adsorption rate and the hydrotrope.
Embodiment 2
By with the acrylic acid of 720 g, as the 3.08g N of internal crosslinker, N,-methylene-bisacrylamide and as 2 of solvent, the deionized water of 718g drops in the reactor and makes reaction solution, described reactor is the both arms type kneader that has the rustless steel of lid to make, volume is 10 liters, has two sigma shape blades and a chuck.Keep described reaction solution, the air nitrogen replacement of internal system down at 15 ℃ then.Then under the situation that stirs described reaction solution, add 2 of 21.6g 10wt%, 2, two (2-amidine propane) the dihydrochloride aqueous solutions of-azo, the L-aqueous ascorbic acid of 18.0g 1wt% and the aqueous hydrogen peroxide solution of 20.6g 3.5-% are with initiated polymerization.When causing, polyreaction stops to stir.Polyreaction is carried out, simultaneously,, and the temperature of chuck is suitably raise so that the temperature of the temperature of reaction solution and chuck is almost identical from one another along with the rising of reaction solution temperature.Subsequently in the temperature of reaction solution behind peaking, by the temperature of control chuck, the temperature maintenance that makes reaction solution is being not less than under 55 ℃ the temperature.After three hours, the blade by rotating described both arms type kneader is with final cross-linked hydrogel polymer fragmentation.In the process of the blade that rotates both arms type kneader, temperature remains on about 50 ℃, simultaneously the sodium hydrate aqueous solution of 750g 40wt% is splashed into and mixes, like this, when in and time when reaching required 6 hours, obtaining neutralization ratio is the aquogel polymer of 75mol%.This hydrogel is dispersed in 50 purposes uses hot-air dry 16 hours down on the net and at 60 ℃.Pulverize the desciccate that obtains with a vibromill then, and, obtain to grind to form the precursor that erose average particulate diameter is the water-absorbing resin of 300 μ m (b) thus with the further classification of 20 purpose nets.
A kind of surface crosslinking agent, it comprises 1 part of (weight) propylene glycol, 0.05 part of (weight) Ethylene glycol diglycidyl ether, 3 parts of (weight) water and 1 part of (weight) isopropyl alcohol, mixes with 100 parts of (weight) water-absorbing resin precursors (b).Final mixture 205 ℃ of down heating 50 minutes, is obtained water absorbing agent b thus, and its adsorption capacity under load condition is 26.9 (g/g), and water content (wet basis) is 1wt% or still less.Spray the described water absorbing agent b of 100 parts (weight) then with the mixed solution of diethylene-triamine pentaacetic acid five sodium that comprise 0.005 part (weight) and 3 parts of (weight) water, dry down at 80 ℃ then, obtain water absorbing agent of the present invention (2) thus, the measurement result of its following performance is recorded in the table 1: the adsorption capacity under no-load condition, adsorption capacity under load condition, static state under load condition is destroyed adsorption capacity (1)～(4), dynamic adsorption capacity under load condition, dynamic destruction adsorption capacity under load condition, approximate adsorption capacity (1)～(2) under load condition, adsorption rate and hydrotrope content.
Comparative example 1
By the sodium acrylate aqueous solution (monomer concentration: make reaction solution 33wt%) that 1.52 parts of (weight) trimethylolpropane triacrylates are dissolved in 5,500 parts of (weight) neutralization ratio is 75mol%.Then this solution was outgased 30 minutes under blanket of nitrogen, add afterwards in the reactor, this reactor is the both arms type kneader that has the rustless steel of lid to make, and capacity is 10 liters, has two sigma shape blades and a chuck.Keep described reaction solution, the air nitrogen replacement of internal system down at 30 ℃.In the process that stirs described reaction solution, add the L-ascorbic acid of 2.46 parts of (weight) sodium peroxydisulfates and 0.10 part (weight) then, begin polyreaction after general like this 1 minute.Described polyreaction is carried out under 30-80 ℃ temperature, and after polymerization begins 60 minutes the aquogel polymer that obtains is taken out.Described final aquogel polymer has the diameter of about 5mm.This dispersive aquogel polymer is dispersed in 50 purposes uses hot-air dry 90 minutes down on the net and at 150 ℃.Then the desciccate that obtains is pulverized with a vibromill, and, obtain to grind to form the precursor that erose average particulate diameter is the water-absorbing resin of 350 μ m (c) thus with the further classification of 20 purpose nets.
A kind of surface crosslinking agent comprising 1 part of (weight) glycerol, 0.05 part of (weight) Ethylene glycol diglycidyl ether, 3 parts of (weight) water and 1 part of (weight) isopropyl alcohol, mixes with the water-absorbing resin precursor (c) that 100 parts (weight) as above obtain.The mixture that obtains heated 40 minutes down at 195 ℃, obtained water absorbing agent c thus, and its adsorption capacity under load condition is 22.3 (g/g), and water content (wet basis) is 1wt% or lower.Then, the mixed solution that will comprise 0.005 part of (weight) diethylene-triamine pentaacetic acid five sodium and 3 parts of (weight) water is sprayed on 100 parts (weight) described water-absorbing resin c, then 80 ℃ of dryings, obtain comparison water absorbing agent (1) like this, the measurement result of its following performance is recorded in the table 1: the adsorption capacity under no-load condition, adsorption capacity under load condition, static state under load condition is destroyed adsorption capacity (1)～(4), dynamic adsorption capacity under load condition, dynamic destruction adsorption capacity under load condition, approximate adsorption capacity (1)～(2) under load condition, the content of the adsorption rate and the hydrotrope.
Comparative example 2
By the sodium acrylate aqueous solution (monomer concentration: make reaction solution 33wt%) that 4.5 parts of (weight) polyethyleneglycol diacrylates (average mol of the ethylene oxide of addition is 8) are dissolved in 5,500 parts of (weight) neutralization ratio is 75mol%.Then this solution was outgased 30 minutes under blanket of nitrogen, add afterwards in the reactor, this reactor is the both arms type kneader that has the rustless steel of lid to make, and volume is 10 liters, has two sigma shape blades and a chuck.Keep described reaction solution, the air nitrogen replacement of internal system down at 30 ℃.Under the situation that stirs described reaction solution, add the L-ascorbic acid of 2.46 parts of (weight) sodium peroxydisulfates and 0.10 part (weight) then, begin polyreaction after general like this 1 minute.Described polyreaction is carried out under 30-80 ℃ temperature, and after polymerization begins 60 minutes the aquogel polymer that obtains is taken out.Described final aquogel polymer has the diameter of about 5mm.This dispersive aquogel polymer is dispersed in 50 purposes uses hot-air dry 90 minutes down on the net and at 150 ℃.Then the desciccate that obtains is pulverized with a vibromill, and further classify, obtain to grind to form the precursor that erose average particulate diameter is the water-absorbing resin of 280 μ m (d) thus with 20 purpose nets.A kind of surface crosslinking agent comprising 1 part of (weight) propylene glycol, 0.05 part of (weight) Ethylene glycol diglycidyl ether, 3 parts of (weight) water and 1 part of (weight) isopropyl alcohol, mixes with the water-absorbing resin precursor (d) that 100 parts (weight) as above obtain.The mixture that obtains heated 40 minutes down at 210 ℃, obtain relatively water absorbing agent (2) thus, the measurement result of its following performance is recorded in the table 1: the adsorption capacity under no-load condition, adsorption capacity under load condition, static state under load condition is destroyed adsorption capacity (1)～(4), dynamic adsorption capacity under load condition, dynamic destruction adsorption capacity under load condition, approximate adsorption capacity (1)～(2) under load condition, adsorption rate and hydrotrope content.
Embodiment 3
By the sodium acrylate aqueous solution that mixes 67.0 parts of (weight) 37wt%, 10.2 parts of (weight) acrylic acid, 0.097 part of (weight) polyethyleneglycol diacrylate (average mol of the ethylene oxide of addition is 8) and 22.0 parts of (weight) water, make monomer solution.In reactor, in this monomer solution, feed nitrogen, make the concentration of the dissolved oxygen in the solution be reduced to 0.1ppm or lower like this.Then, under blanket of nitrogen with the thermoregulation to 18 of this solution ℃.Stir then and drip 0.16 part of (weight) 5wt% sodium persulfate aqueous solution, 0.16 part of (weight) 5wt%2 down in order, 2, two (2-amidine propane) the hydrochloride aqueous solutions of-azo, 0.15 part of (weight) 0.5wt% aqueous ascorbic acid and 0.17 part of (weight) 0.35wt% aqueous hydrogen peroxide solution.
After dripping hydrogen peroxide, polyreaction gets started, and through after 10 minutes, monomer temperature reaches peak temperature again.This peak temperature is 85 ℃.Then, this reactor immersed in one 80 ℃ the hot bath ageing 15 minutes.
The transparent aquagel that obtains carries out fragmentation with meat grinder, final finely divided aquogel polymer is dispersed in 50 purposes uses hot-air dry 65 minutes down on the net and at 160 ℃.Then the desciccate that obtains is pulverized with a pulverizer, and be classified into the sieve by 850 μ m but still be retained in granule on the 106 μ m sieves, obtain to grind to form the precursor that erose average particulate diameter is the water-absorbing resin of 320 μ m (e) like this.
A kind of surface crosslinking agent, comprising 1 part of (weight) propylene glycol, 0.5 part of (weight) 1,4-butanediol, 3 parts of (weight) water and 1 part of (weight) isopropyl alcohol mix with the water-absorbing resin precursor (e) that 100 parts (weight) as above obtain.The mixture that obtains was heated 40 minutes down at 210 ℃, obtain water absorbing agent e thus, its adsorption capacity under load condition is 26.6 (g/g), and water content (wet basis) is 1wt% or lower.Then, the mixed solution that will comprise 0.005 part of (weight) diethylene-triamine pentaacetic acid five sodium and 3 parts of (weight) water is sprayed on 100 parts (weight) described water-absorbing resin e, then 80 ℃ of dryings, obtain water absorbing agent of the present invention (3) like this, the measurement result of its following performance is recorded in the table 1: the adsorption capacity under no-load condition, adsorption capacity under load condition, static state under load condition is destroyed adsorption capacity (1)～(4), dynamic adsorption capacity under load condition, dynamic destruction adsorption capacity under load condition, approximate adsorption capacity (1)～(2) under load condition, the content of the adsorption rate and the hydrotrope.
Comparative example 3
By the 10.6g polyethyleneglycol diacrylate is dissolved in 6, the 570g neutralization ratio is to make reaction solution in the neutral 30wt% sodium acrylate of the part of the 75mol% aqueous solution.Then this solution is added in the reactor, this reactor is the rustless steel both arms type kneader that lid is arranged, and volume is 10 liters, has two sigma shape blades and a chuck.Recirculated water by 30 ℃ of feedings in chuck makes described reaction solution remain on 30 ℃, the air nitrogen replacement of simultaneity factor inside.Under the rotating speed stirring of blade with 40rpm of kneader, in reactor, add sodium persulfate aqueous solution and the L-aqueous ascorbic acid of 14.9g 0.1%, initiated polymerization so then as the 15.6g 20wt% of initiators for polymerization.After becoming muddy by reactant mixture and determining that polyreaction is initiated, stop the rotation of blade, and reactant mixture reacted with giving free rein to, up to remove owing to chuck heat make in temperature drop to 60 ℃.When interior temperature further drops to when being lower than 60 ℃, moving blade and make the gel fragmentation that obtains polyreaction is further carried out, and warm peak value reaches 75 ℃ in making.Then, jacket temperature is raised to 60 ℃, and when gel is integrated, and paradigmatic system kept 20 minutes at 65 ℃ or higher temperature, and polyreaction is carried out fully.
The aquogel polymer that obtains is used hot-air dry 65 minutes down at 160 ℃.Then the desciccate that obtains is pulverized with a vibromill, obtained to grind to form the precursor that erose average particulate diameter is the water-absorbing resin of 450 μ m (f) thus.
A kind of surface crosslinking agent comprising 0.5 part of (weight) glycerol, 0.05 part of (weight) Ethylene glycol diglycidyl ether, 3 parts of (weight) water and 0.75 part of (weight) isopropyl alcohol, mixes with the water-absorbing resin precursor (f) that 100 parts (weight) as above obtain.The mixture that obtains was heated 50 minutes down at 200 ℃, obtain relatively water absorbing agent (3) thus, the measurement result of its following performance is recorded in the table 1: the adsorption capacity under no-load condition, adsorption capacity under load condition, static state under load condition is destroyed adsorption capacity (1)～(4), dynamic adsorption capacity under load condition, dynamic destruction adsorption capacity under load condition, approximate adsorption capacity (1)～(2) under load condition, adsorption rate and hydrotrope content.
Table 1
Embodiment 1 Embodiment 2 Comparative example 1 Comparative example 2 Embodiment 3 Comparative example 3
The water absorbing agent that uses Water absorbing agent 1 Water absorbing agent 2 Compare water absorbing agent 1 Compare water absorbing agent 2 Water absorbing agent 3 Compare water absorbing agent 3
Adsorption capacity (g/g) under adsorption capacity under non-loaded (g/g) load 31.6 26.8 37.5 26.3 35.5 22.6 31.3 26.7 34.4 26.4 35.5 27.6
Adsorption rate (second) hydrotrope content (%) 42 6 35 2 45 25 31 12 43 5 83 6
(g/g) the approximate adsorption capacity (2) under the load is (g/g) for approximate adsorption capacity (1) under the load 24.8 24.8 25.0 23.2 16.7 15.7 21.6 19.3 25.1 24.3 - -
Static state under the load destroy adsorption capacity (1) (g/g) load static state down destroy adsorption capacity (2) (g/g) load static state destruction adsorption capacity (3) down (g/g) the static state destruction adsorption capacity (4) under the load is (g/g) 24.7 25.9 24.5 32.1 23.5 25.2 24.8 36.2 15.4 16.8 1 5.9 24.8 18.8 22.0 18.5 16.4 24.1 24.9 24.2 34.2 19.2 22.5 19.0 26.0
Dynamic destruction adsorption capacity (g/g) under dynamic adsorption capacity under the load (g/g) load 25.3 22.3 26.0 23.4 16.5 15.4 25.3 15.6 25.5 22.5 26.1 19.2
Embodiment 4
At first, the water absorbing agent that 50 parts (weight) is obtained as embodiment 1 with a blender (1) is admixed together with dried forms with 50 parts of (weight) powdery wood pulps.Then, this mixture strength is molded into (slot size is 38 μ m) on the one 400 purpose screen clothes, makes the fabric of 120mm * 380mm size with a batch-type pneumatic plant.In addition, at 2Kg/cm 2Following this fabric of extruding 5 seconds of pressure, obtain weight like this and be about 526g/m 2Adsorbing material.
Then, tergite (waterproof), above-mentioned adsorbing material and the top flat of making by the polypropylene of porous made by fluid-tight polypropylene that will have so-called flank (leg gather), stick together with two-sided tape with this order, parts with two so-called fixing bands (tapefastener) are added on the sticky object that obtains then, obtain absorbent articles (being diaper) like this.The weight of this absorbent articles is 47g.
Described absorbent articles is fixed on four so-called kewpie dolls (body of three dolls is long to be 55cm, heavily be 5Kg, and another individual long be 65cm, heavily be 6Kg), and make these dolls recumbency that under 37 ℃ of following room temperatures, faces down.Then, a pipe is inserted in the middle of absorbent articles and the doll, and by this pipe, the physiological sodium chloride solution that 50g is contained the L-ascorbic acid of 0.005wt% concentration every 90 minutes injects from the position that is equivalent to discharge from human body urine.Then, when the physiological sodium chloride solution of injection no longer is adsorbed goods absorption and when beginning to leak, finish injection operation, and measure the amount of the physiological sodium chloride solution of injection thitherto, the meansigma methods of above-mentioned four kewpie dolls is regarded as the adsorbance of described absorbent articles under the state of recumbency that faces down.The result of the adsorbance under the state of recumbency that faces down (g), and the destruction adsorption exponent value under the load, approximate concentration adsorption exponent value and static and dynamically destroy concentration adsorption exponent value and list in table 2.
Embodiment 5 and 6
Obtain absorbent articles with similarly to Example 4 method, just respectively with the water absorbing agent that obtains in embodiment 2 and 3 (2) and (3) replacement water absorbing agent (1).The weight of the absorbent articles that obtains all is 47g.
Measure the adsorbance of these absorbent articles under the state of recumbency that faces down in mode similarly to Example 4.The result of the adsorbance under the state of recumbency that faces down (g), and the destruction adsorption exponent value under the load, approximate concentration adsorption exponent value and static and dynamically destroy concentration adsorption exponent value and list in table 2.
Comparative example 4,5 and 6
Obtain the comparison absorbent articles with similarly to Example 4 method, just respectively with the comparison water absorbing agent (1) that obtains in comparative example 1,2 and 3, (2) and (3) replacement water absorbing agent (1).The weight of the absorbent articles that obtains all is 47g.
Measure the adsorbance of these absorbent articles under the state of recumbency that faces down in mode similarly to Example 4.The result of the adsorbance under the state of recumbency that faces down (g), and the destruction adsorption exponent value under the load, approximate concentration adsorption exponent value and static and dynamically destroy concentration adsorption exponent value and list in table 2.
Table 2
Embodiment 4 Embodiment 5 Comparative example 4 Comparative example 5 Embodiment 6 Comparative example 6
Used water absorbing agent Water absorbing agent 1 Water absorbing agent 2 Compare water absorbing agent 1 Compare water absorbing agent 2 Water absorbing agent 3 Compare water absorbing agent 3
Destruction adsorption exponent (g/g) under the load 129.5 133.1 88.3 91.3 129.9 105.9
The static concentration adsorption exponent (g/g) that destroys of approximate concentration adsorption exponent (g/g) dynamically destroys concentration adsorption exponent (g/g) 28.2 28.2 27.0 30.4 30.5 30.5 25.6 25.5 25.5 25.3 25.1 23.5 29.4 29.3 28.5 27.4 27.4
Adsorbance (g) under the recumbency state faces down 275 288 250 250 288 268
(footnote): the weight ratio of the total amount of the water absorbing agent of all uses and water absorbing agent and fiber base material all is 0.5.
Embodiment 7
At first, the water absorbing agent that 75 parts (weight) is obtained as embodiment 1 with a blender (1) is admixed together with dried forms with 25 parts of (weight) powdery wood pulps.Then, this mixture strength is molded into (slot size is 38 μ m) on the one 400 purpose screen clothes, makes the fabric of 120mm * 350mm size with a batch-type pneumatic plant.In addition, at 2Kg/cm 2Following this fabric of extruding 5 seconds of pressure, obtain weight like this and be about 500g/m 2Adsorbing material.
Then, egative film (waterproof), above-mentioned adsorbing material and the top flat of making by the polypropylene of porous made by fluid-tight polypropylene that will have so-called flank (leg gather), stick together with two-sided tape with this order, then the parts of two so-called fixing bands (tapefastener) are added to and obtain on the sticky object, obtain absorbent articles (being diaper) like this.The weight of this absorbent articles is 44g.
Described absorbent articles is fixed on four so-called kewpie dolls (body of three dolls is long to be 55cm, heavily be 5Kg, and another individual long be 65cm, heavily be 6Kg), and make these dolls recumbency that under 37 ℃ of following room temperatures, faces down.Then, a pipe is inserted in the middle of absorbent articles and the doll, and by this pipe, the physiological sodium chloride solution that 50g is contained the L-ascorbic acid of 0.005wt% concentration every 90 minutes injects from the position that is equivalent to discharge from human body urine.Then, when the physiological sodium chloride solution of injection no longer is adsorbed goods absorption and when beginning to leak, finish injection operation, and measure the amount of the physiological sodium chloride solution of injection thitherto, the meansigma methods of above-mentioned four kewpie dolls is regarded as the adsorbance of described absorbent articles under the state of recumbency that faces down.The result of the adsorbance under the state of recumbency that faces down (g), and the destruction adsorption exponent value under the load, approximate concentration adsorption exponent value and static and dynamically destroy concentration adsorption exponent value and list in table 3.
Embodiment 8 and 9
Obtain absorbent articles with similarly to Example 7 method, just respectively with the water absorbing agent that obtains in embodiment 2 and 3 (2) and (3) replacement water absorbing agent (1).The weight of the absorbent articles that obtains all is 44g.
To measure the adsorbance of these absorbent articles under the state of recumbency that faces down with the same manner of embodiment 7.The result of the adsorbance under the state of recumbency that faces down (g), and the destruction adsorption exponent value under the load, approximate concentration adsorption exponent value and static and dynamically destroy concentration adsorption exponent value and list in table 3.
Comparative example 7,8 and 9
Obtain the comparison absorbent articles with similarly to Example 7 method, just respectively with the comparison water absorbing agent (1) that obtains in comparative example 1,2 and 3, (2) and (3) replacement water absorbing agent (1).The weight of the absorbent articles that obtains all is 44g.
Measure the adsorbance of these absorbent articles under the state of recumbency that faces down in mode similarly to Example 7.The result of the adsorbance under the state of recumbency that faces down (g), and the destruction adsorption exponent value under the load, approximate concentration adsorption exponent value and static and dynamically destroy concentration adsorption exponent value and list in table 3.
Table 3
Embodiment 7 Embodiment 8 Comparative example 7 Comparative example 8 Embodiment 9 Comparative example 9
Used water absorbing agent Water absorbing agent 1 Water absorbing agent 2 Compare water absorbing agent 1 Compare water absorbing agent 2 Water absorbing agent 3 Water preparation 3 relatively absorbs water
Destruction adsorption exponent (g/g) under the load 129.5 133.1 88.3 91.3 129.9 105.9
The static concentration adsorption exponent (g/g) that destroys of approximate concentration adsorption exponent (g/g) dynamically destroys concentration adsorption exponent (g/g) 26.5 26.4 24.6 26.8 27.0 26.9 20.7 20.4 20.4 22.3 21.9 19.5 26.8 26.7 25.5 - 23.3 23.3
Adsorbance (g) under the recumbency state faces down 275 275 238 250 288 268
(footnote): the weight ratio of the total amount of the water absorbing agent of all uses and water absorbing agent and fiber base material all is 0.75.
Embodiment 10
At first, the water absorbing agent that 60 parts (weight) is obtained as embodiment 1 with a blender (1) is admixed together with dried forms with 40 parts of (weight) powdery wood pulps.Then, this mixture strength is molded into (slot size is 38 μ m) on the one 400 purpose screen clothes, makes the fabric of 120mm * 380mm size with the batch-type pneumatic plant.In addition, at 2Kg/cm 2Following this fabric of extruding 5 seconds of pressure, obtain weight like this and be about 530g/m 2Adsorbing material.
Then, tergite (waterproof), above-mentioned adsorbing material and the top flat of making by the polypropylene of porous made by fluid-tight polypropylene that will have so-called flank (leg gather), stick together with two-sided tape with this order, parts with two so-called fixing bands (tapefastener) are added on this sticky object then, obtain absorbent articles (being diaper) like this.The weight of this absorbent articles is about 47g.
Comparative example 10
Obtain the comparison absorbent articles with same quadrat method, just replace water absorbing agent (1) with the comparison water absorbing agent (2) that obtains in the comparative example 2 with embodiment 10.The weight of the absorbent articles that obtains is about 47g.
Child between 1 years old 08 months to 2 years old 04 months carries out following test with 5 ages.Ten absorbent articles (as obtaining among the embodiment 10) and ten comparison absorbent articles (as obtaining in the comparative example 10) are distributed to each child.After each diaper uses an evening, collect diaper, check the amount of the urine that diaper adsorbs and when child is being with diaper, whether have urine to leak and take place.The processing of data is to calculate to have adsorbed the 150g or the absorbent articles of polyuria liquid more, gets rid of for example owing to diaper breaks away from the leakage that its appropriate location causes when wearing.The results are shown in table 4.
For having adsorbed the 150g or the diaper of polyuria liquid more, its urine average magnitude is the number of the total volume of urine of these diaper absorption divided by diaper.
For having adsorbed the 150g or the diaper of polyuria liquid more, the urine average magnitude of leaking example is these diaper up to the number of the total volume of urine that leaks absorption when taking place divided by the diaper that has taken place to leak.
Slip be the diaper quantity of having adsorbed 150g or more having taken place in the diaper of polyuria liquid to leak with adsorbed 150g or the ratio of the quantity of the diaper of polyuria liquid (percentage ratio) more.
Table 4
Employed water absorbing agent Water absorbing agent (1) Compare water absorbing agent (2)
Mean urinary liquid measure (g) 258 261
Leak the mean urinary liquid measure (g) in the example 355 324
Leakage rate (%) 8 12
List in table 5 as for commercially available diaper (being to buy), calculate its following performance and be listed in table 5 in April, 1998 to JIUYUE:
The weight ratio of water-absorbing resin and water-absorbing resin and fiber base material total amount, i.e. water-absorbing resin concentration;
The performance of water-absorbing resin, for example: the adsorption capacity under no-load condition, adsorption capacity under load condition, adsorption rate, hydrotrope content, approximate adsorption capacity (1)～(2) under load condition, static state under load condition is destroyed adsorption capacity (1)～(4), dynamic adsorption capacity under load condition is at dynamic destruction adsorption capacity under the load condition and the destruction adsorption exponent under load condition; With
The performance of adsorbing material, for example approximate concentration adsorption exponent and the static and dynamic concentration adsorption exponent that destroys.
The measuring method of each performance is as follows:
(1) water-absorbing resin concentration;
Each described diaper that is purchased under vacuum in 60 ℃ of dryings 16 hours.Then, if any, from each diaper, remove tergite, top flat, non-woven fabric plate, paper and acquisition layer (some above-mentioned diaper also comprises such acquisition layer of being made by fiber base material), mainly comprised the adsorption layer of water-absorbing resin and fiber base material.Then, measure the weight X (g) of adsorption layer, and measure the weight Y (g) that is included in the water-absorbing resin in the adsorption layer, be calculated as follows out water-absorbing resin concentration like this:
Water-absorbing resin concentration=Y/X
(2) performance of water-absorbing resin:
The water-absorbing resin and the fiber base material that are included in the adsorbing material of each diaper that is purchased are separated from each other, then under vacuum in 60 ℃ of dryings 16 hours.Then, measure the performance of water-absorbing resin with aforementioned method, for example: the adsorption capacity under no-load condition, adsorption capacity under load condition, adsorption rate, the content of the hydrotrope, approximate adsorption capacity (1)～(2) under load condition, static state under load condition is destroyed adsorption capacity (1)～(4), in dynamic adsorption capacity under the load condition and the dynamic destruction adsorption capacity under load condition.In addition, the destruction adsorption exponent of water-absorbing resin under load condition be measure destroy the summation of the value of adsorption capacity (1)～(4) and the dynamic adsorption capacity under load condition in the static state under the load condition.
(3) performance of adsorbing material:
The water-absorbing resin and the fiber base material that are included in the adsorbing material of each diaper that is purchased are separated from each other, then under vacuum in 60 ℃ of dryings 16 hours.Then, calculate approximate concentration adsorption exponent and the static and dynamic concentration adsorption exponent that destroys.
Table 5
Trade name Moony Power Slim Pampers Sara-Sara Care Pampers Premium HUGGLES forBoys Dri-Bottoms Supreme
Specification L L Maxi Plus Maxi 4
Producer UNI- charM K.K. P﹠G Messrs.Far East ﹠ Co., Ltd P&G Kimbery-Clark company Paragon Trade Brands
Buy country Japan Japan Germany Britain The U.S.
Water-absorbing resin concentration 0.4 0.49 0.5 0.4 0.4
Adsorption capacity (g/g) under non-loaded adsorption capacity (g/g) load down 37 8 29 23 31 24 28 15 31 24
Adsorption rate (second) hydrotrope content (%) 29 7.2 71 9.7 45 12 38 9.0 36 9.1
(g/g) the approximate adsorption capacity (2) under the load is (g/g) for approximate adsorption capacity (1) under the load 15.7 15.2 20.0 19.4 20.6 19.4 15.8 15.4 21.4 19.7
Static state under the load destroy adsorption capacity (1) (g/g) load static bad adsorption capacity (2) down (g/g) load static state destruction adsorption capacity (3) down (g/g) the static state destruction adsorption capacity (4) under the load is (g/g) 15.2 15.5 15.3 1 5.4 16.3 18.0 16.4 15.6 17.2 21.5 17.5 16.4 15.3 15.6 15.4 25.7 17.4 21.2 17.2 24.3
Dynamic destruction adsorption capacity (g/g) under dynamic adsorption capacity under the load (g/g) load 15.2 15.4 20.0 15.4 22.0 16.1 15.8 15.3 21.2 17.5
Destruction adsorption exponent (g/g) under the load 76.8 81.7 88.7 87.3 97.6
Adsorbing material The static concentration adsorption exponent (g/g) that destroys of approximate concentration adsorption exponent (g/g) dynamically destroys concentration adsorption exponent (g/g) 28.3 28.3 28.4 24.3 22.8 22.3 25.2 24.1 23.6 23.0 22.9 22.9 26.5 25.6 25.6
Hereinafter, the example of certain preferred embodiments of the water absorbing agent with excellent urine patience of the present invention and the example of production method thereof will be described in detail.But the present invention is not limited to these examples.In addition, in embodiment and comparative example, unless otherwise noted, unit " % " and " part " all refer to unit of weight.
By the way, the performance of water absorbing agent, for example water absorption, hydrotrope content and the solubles content that is eluted in the artificial urine are measured with following method.
(1) water absorption of water absorbing agent:
(6cm * 6cm), its opening heat-sealing is immersed this sack in physiological sodium chloride solution then then at first the 0.2g water-absorbing resin to be put into equably the bag of a tea-bag shape.After 60 minutes, take out sack, dewatered 3 minutes under 250G with a centrifuge then, measure the weight W of bag then 1(g).On the other hand, carry out same process, measure the final weight W of bag without water absorbing agent 0(g).Like this, according to following formula by weight W 1And W 0Calculate water absorption (g/g):
Water absorption (g/g)=(W 1-W 0The weight of)/(water-absorbing resin (g))
(2) solubles content of eluting from water absorbing agent:
At first, make 1g water absorbing agent swelling with the 25ml artificial urine in a 100ml beaker, this beaker left standstill 16 hours at 37 ℃.Subsequently, be dispersed in the swell gel that obtains in the 975ml deionized water and stirred 1 hour, use filter paper filtering then.The filtrate that obtains is used the colloid titration method titration, to measure the solubles content of eluting from water absorbing agent.
Artificial urine composed as follows:
Carbamide 1.9%
Sodium chloride 0.8%
Magnesium chloride 0.1%
Calcium chloride 0.1%
3) solubles content of destroyed and eluting in the water absorbing agent:
At first, in a 100ml beaker, the artificial urine that contains the L-ascorbic acid of 0.005% concentration with 25ml makes 1g water absorbing agent swelling, and this beaker left standstill 16 hours at 37 ℃ then.Subsequently, the swell gel that obtains is dispersed in the 975ml deionized water, so that the soluble substance that goes out to separate with rinsed with deionized water.Stir this dispersion 1 hour, and used filter paper filtering then.The filtrate that obtains is used the colloid titration method titration, with the solubles content of destroyed in the mensuration water absorbing agent and eluting.
(4) adsorption capacity under load:
The adsorption capacity of measuring device measurement under load with Fig. 1.As shown in Figure 1, this measuring device comprises: scale 1; Be added in the container 2 of the predetermined volume on the scale 1; Air inlet pipe 3; Conduit 4; Glass filter 6; Be added in the measure portion 5 on the glass filter 6.At the top of container 2 an opening 2a is arranged, an opening 2b is arranged in its side.Air inlet pipe 3 is inserted from opening 2a, and conduit 4 is fixed on the opening 2b.In addition, the sodium-chloride water solution 12 (after this being called physiological sodium chloride solution) that contains the 0.9wt% of scheduled volume in the container 2.The lower end of air inlet pipe 3 is immersed in the physiological sodium chloride solution 12.Being installed into trachea 3 is in order to keep the intrinsic pressure near atmospheric pressure of container 2.The diameter of glass filter 6 is 55mm.Container 2 is connected to each other together by the conduit of being made by silicone resin 4 with glass filter 6.In addition, the position of glass filter 6 and level height are fixed with respect to container 2.Measure portion 5 comprises: filter paper 7; Support cylinder tube 9; Be fixed on the wire netting 10 of support cylinder tube 9 bottoms; With weight 11.By being added in proper order with this, filter paper 7 and support cylinder tube 9 (being wire netting 10) constitute measure portion 5 on the glass filter 6.Wire netting 10 is made by rustless steel, and it is 400 orders that its order is counted size.The upper surface of wire netting 10, promptly wire netting 10 is in same level height with the contact surface of water absorbing agent 15 and the lower surface 3a of air inlet pipe 3.On wire netting 10, the water absorbing agent of homodisperse scheduled volume.Regulate the weight of weight 11, so as on the wire netting 10, be the load that evenly applies 0.7psi on the water absorbing agent 15.
With the adsorption capacity of measuring device measurement under load with above-mentioned formation.The explained later measuring method.
At first, finish the operation of predetermined preparation property, wherein for example, the physiological sodium chloride solution 12 of scheduled volume is joined in the container 2, and air inlet pipe 3 is inserted containers 2.Subsequently, filter paper 7 is put on the glass filter 6.On the other hand, with these reinforced operation whiles, the 0.9g water absorbing agent is dispersed in the support cylinder tube 9, is on the wire netting 10, and weight 11 is put on the water absorbing agent 15.Subsequently, with wire netting 10, be that support cylinder tube 9 (water absorbing agent 15 and weight 11 are placed on it) is placed on the filter paper 7, and make the centrage of support cylinder tube 9 consistent with the centrage of glass filter 6.Then, be placed in 60 fens clock times of filter paper 7 beginning from support cylinder tube 9, the value that the weight of the physiological sodium chloride solution that water absorbing agent 15 is adsorbed is measured by scale 1 draws.In addition, carry out top same process without water absorbing agent 15, draw the weight of the adsorbed physiological sodium chloride solution of material (for example filter paper) 7 except that water absorbing agent by scale 1 measured value, this is taken as blank value.Calculate adsorbance under load by following formula:
Adsorption capacity under load (g/g)=
(water absorption-blank after 60 minutes)/(weight of water absorbing agent).
(5) mean diameter of water absorbing agent
Water absorbing agent sieves and classification with the sieve of 850 μ m, 600 μ m, 500 μ m, 425 μ m, 300 μ m, 220 μ m, 150 μ m and 105 μ m, the percentage ratio of residue on sieve then draws on logarithmic paper, be the curve of R, will be used as average particulate diameter corresponding to the particle diameter of R=50% to particle diameter.
(6) water content of water-absorbing resin (wet basis):
The water-absorbing resin of about 1g was heated 3 hours in 105 ℃ baking oven, before and after heating, measures the weight W (g) of described water-absorbing resin respectively, calculate water content (wet basis) according to following formula:
Water content (wt%)=(W Before the heating(g)-W After the heating(g))/W Before the heating(g) wherein: W Before the heating(g) be the weight of described water-absorbing resin before oven dry;
W After the heating(g) be the weight of described water-absorbing resin after oven dry.
Reference example 1
By mixing 67.0 parts of concentration is 37% sodium acrylate aqueous solution, 10.2 parts of acrylic acid, 0.079 part of polyethyleneglycol diacrylate (average mol of the ethylene oxide of addition is 8) and 22.0 parts of water, makes monomer solution.In reactor, in this monomer solution, feed nitrogen, make the concentration of the dissolved oxygen in the solution be reduced to 0.1ppm or lower like this.
Then, under blanket of nitrogen with the thermoregulation to 18 of this solution ℃.Stir then drip in order down 0.16 part of 5% sodium persulfate aqueous solution, 0.16 part 5% 2,2, two (2-amidine propane) the hydrochloride aqueous solutions of-azo, 0.15 part 0.5% L-aqueous ascorbic acid and 0.17 part 0.35% aqueous hydrogen peroxide solution.
After dripping hydrogen peroxide, polyreaction gets started, and through after 10 minutes, monomer temperature reaches peak temperature again.This peak temperature is 85 ℃.Then, with ageing in the hot bath of 80 ℃ of this reactor immersions 10 minutes.
The transparent aquagel that obtains is carried out fragmentation with meat grinder, then 180 ℃ of dryings 30 minutes.
The desciccate that obtains is pulverized with pulverizer, and sieved the sieve by 500 μ m but still be retained in granule on the 105 μ m sieves, obtain water-absorbing resin (A) like this.
Embodiment 2-1
The combination solution that will comprise 0.001 part of diethylene-triamine pentaacetic acid five sodium, 0.05 part of Ethylene glycol diglycidyl ether, 1 part of propylene glycol, 3 parts of water and 1 part of isopropyl alcohol mixes as the water-absorbing resin (A) that obtains in the above-mentioned reference example with 100 parts, the mixture that obtains heated 40 minutes down at 180 ℃, obtained water absorbing agent thus.The performance evaluation of final water absorbing agent (E2-1) the results are shown in table 2-1.
Embodiment 2-2
According to obtaining a kind of water absorbing agent of the present invention with the same mode of embodiment 2-1, but the consumption of diethylene-triamine pentaacetic acid five sodium changes 0.01 part into.The performance evaluation of final water absorbing agent (E2-2) the results are shown in table 2-1.
Embodiment 2-3
According to obtaining a kind of water absorbing agent of the present invention with the same mode of embodiment 2-1, but the consumption of diethylene-triamine pentaacetic acid five sodium changes 0.1 part into.The performance evaluation of final water absorbing agent (E2-3) the results are shown in table 2-1.
Embodiment 2-4
According to obtaining a kind of water absorbing agent of the present invention, but replace diethylene-triamine pentaacetic acid five sodium with 0.01 part triethylenetetraaminehexaacetic acid six sodium with the same mode of embodiment 2-1.The performance evaluation of final water absorbing agent (E2-4) the results are shown in table 2-1.
Embodiment 2-5
According to obtaining a kind of water absorbing agent of the present invention, but replace diethylene-triamine pentaacetic acid five sodium with 0.01 part 1,2-diaminocyclohexane tetraacetic acid salt with the same mode of embodiment 2-1.The performance evaluation of final water absorbing agent (E2-5) the results are shown in table 2-1.
Comparative example 2-1
According to obtaining a kind of relatively water absorbing agent, but do not add diethylene-triamine pentaacetic acid five sodium with the same mode of embodiment 2-1.The performance evaluation of final comparison water absorbing agent (R2-1) the results are shown in table 2-1.
Reference example 2
By mixing 81.8 part 38% sodium acrylate aqueous solution, 7.7 parts of acrylic acid, 0.038 part of trimethylolpropane triacrylate and 9.8 parts of water, make monomer solution.
In a double arm kneading mixer that is equipped with chuck, in described monomer solution, be blown into nitrogen, remove the dissolved oxygen in the solution like this.Then, with the thermoregulation to 22 of this monomer solution ℃.
Stir the L-aqueous ascorbic acid that adds 0.60 part of 10% sodium persulfate aqueous solution and 0.30 part 0.1% down then.Added back 1 minute, it is muddy that monomer solution begins to become, and its temperature begins to rise.Through 20 minutes, temperature reached peak temperature again, this solution ageing 20 minutes more under agitation then.Peak temperature is 96 ℃.
After ageing finishes, take out the gel that obtains and 170 ℃ of dryings 65 minutes.The dry polymer that obtains is pulverized, and sieved, obtain water-absorbing resin (B) like this with the sieve of 850 μ m.
Embodiment 2-6
The combination solution that will comprise 0.001 portion of 1,2-diaminocyclohexane tetraacetic acid salt, 0.5 part of ethylene carbonate, 3 parts of water and 3 parts of isopropyl alcohols mixes with 100 parts of water-absorbing resins (B), and the mixture that obtains was heated 50 minutes down at 190 ℃, obtains a water absorbing agent thus.The performance evaluation of final water absorbing agent (E2-6) the results are shown in table 2-1.
Embodiment 2-7
According to obtaining a kind of water absorbing agent of the present invention with the same mode of embodiment 2-6, but with 0.5 part 1, the 4-butanediol replaces ethylene carbonate.The performance evaluation of final water absorbing agent (E2-7) the results are shown in table 2-1.
Comparative example 2-2
According to obtaining a kind of relatively water absorbing agent, but do not add 1,2-diaminocyclohexane tetraacetic acid salt with the same mode of embodiment 2-6.The performance evaluation of final comparison water absorbing agent (R2-2) the results are shown in table 2-1.
Comparative example 2-3
According to obtaining a kind of relatively water absorbing agent, but do not add 1,2-diaminocyclohexane tetraacetic acid salt with the same mode of embodiment 2-7.The performance evaluation of final comparison water absorbing agent (R2-3) the results are shown in table 2-1.
Table 2-1
Embodiment number Water absorbing agent number Water absorption (g/g) Water absorption under the load (g/g) The solubles content that removes (%) Destroyed and remove solubles content (%)
Embodiment 2-1 E2-1 34.4 28.8 11.1 13.8
2-2 E2-2 34.3 28.1 11.1 12.0
2-3 E2-3 34.4 27.9 11.2 11.3
2-4 E2-4 34.1 28.2 10.9 11.5
2-5 E2-5 34.2 27.8 11.0 11.8
2-6 E2-6 28.0 22.0 10.5 10.9
2-7 E2-7 27.8 23.5 10.8 11.5
Comparative example 2-1 R2-1 34.0 28.0 11.1 24.5
2-2 R2-2 28.1 22.1 10.5 25.6
2-3 R2-3 28.0 23.4 10.7 26.0
Embodiment 3-1
The mixed solution that will comprise 0.001 part of diethylene-triamine pentaacetic acid five sodium and 3 parts of water is sprayed 100 parts on the comparison water absorbing agent (R2-1) that obtains in comparative example 2-1, and thereby with the water absorbing agent pelletize, 80 ℃ of dryings, obtain a water absorbing agent so then.The evaluation result of final water absorbing agent (E3-1) is listed in table 3-1.
Embodiment 3-2
According to obtaining a kind of water absorbing agent with the same mode of embodiment 3-1, but the consumption of diethylene-triamine pentaacetic acid five sodium changes 0.1 part into.The evaluation result of final water absorbing agent (E3-2) is listed in table 3-1.
Embodiment 3-3
According to obtaining a kind of water absorbing agent, but replace diethylene-triamine pentaacetic acid five sodium with 0.001 part triethylenetetraaminehexaacetic acid six sodium with the same mode of embodiment 3-1.The evaluation result of final water absorbing agent (E3-3) is listed in table 3-1.
Comparative example 3-1
Water absorbing agent (A) itself is taken as comparison water absorbing agent (R3-1).Relatively the performance evaluation of water absorbing agent (R3-1) the results are shown in table 3-1.
Comparative example 3-2
According to obtaining a kind of relatively water absorbing agent, just only use 3 parts of (weight) water and 100 parts (weight) comparison water absorbing agent (R2-1) to mix with the same mode of embodiment 3-1.Relatively the performance evaluation of water absorbing agent (R3-2) the results are shown in table 3-1.
Table 3-1
Embodiment number Water absorbing agent number Water absorption (g/g) The solubles content that removes (%) Destroyed and remove solubles content (%) Adsorption capacity under the load (g/g) Average particulate diameter (μ m)
Embodiment 3-1 E3-1 34 11 15 27 420
3-2 E3-2 33 11 11 27 420
3-3 E3-3 33 11 12 27 420
Comparative example 3-1 R3-1 34 11 25 27 280
3-2 R3-2 34 11 29 26 420
Embodiment 4-1
To comprise 0.01 part of N, N '-two (1,2-dicarboxyl ethyl)-combination solution of ethylenediamine tetraacetic sodium, 0.05 part of Ethylene glycol diglycidyl ether, 1 part of propylene glycol, 3 parts of water and 1 part of isopropyl alcohol mixes as the water-absorbing resin (A) that obtains in the reference example 1 with 100 parts, the mixture that obtains was heated 40 minutes down at 180 ℃, obtain a water absorbing agent thus.The performance evaluation of final water absorbing agent (E4-1) the results are shown in table 4-1.
Comparative example 4-1
According to obtaining a kind of relatively water absorbing agent with the same mode of embodiment 4-1, but do not add 0.01 part of N, N '-two (1,2-dicarboxyl ethyl)-ethylenediamine tetraacetic sodium does not perhaps add 0.05 part of Ethylene glycol diglycidyl ether.The performance evaluation of final comparison water absorbing agent (R4-1) the results are shown in table 4-1.Relatively the water content of water absorbing agent (R4-1) is 1% (weight) or lower.
Embodiment 4-2
To comprise 0.001 part (S, S)-N, N,-two (1,2-dicarboxyl ethyl)-combination solution of ethylenediamine trisodium and 3 parts of water mixes as the comparison water absorbing agent (R4-1) that obtains among the comparative example 4-1 with 100 parts, with the mixture that obtains 80 ℃ dry 20 minutes down, obtain a water absorbing agent thus.The performance evaluation of final water absorbing agent (E4-2) the results are shown in table 4-1.
Embodiment 4-3
According to obtaining a kind of water absorbing agent with the same mode of embodiment 4-2, but (S, S)-N, the consumption of N '-two (1,2-dicarboxyl ethyl)-ethylenediamine trisodium changes 0.01 part into.The performance evaluation of final water absorbing agent (E4-3) the results are shown in table 4-1.
Embodiment 4-4
According to obtaining a kind of water absorbing agent with the same mode of embodiment 4-2, but the combination solution that will comprise 0.1 part of N-(1,2-dicarboxyl-2-hydroxyethyl)-aspartic acid four sodium and 5 parts of water with 100 parts relatively water absorbing agents (R4-1) mix.The performance evaluation of final water absorbing agent (E4-4) the results are shown in table 4-1.
Embodiment 4-5
According to obtaining a kind of water absorbing agent, but with 0.01 part N with the same mode of embodiment 4-2, N ,-two (1,2-dicarboxyl-2-hydroxyethyl)-ethylenediamine tetraacetic sodium replace 0.001 part (S, S)-N, N ,-two (1,2-dicarboxyl ethyl)-ethylenediamine trisodiums.The performance evaluation of final water absorbing agent (E4-5) the results are shown in table 4-1.
Embodiment 4-6
According to obtaining a kind of water absorbing agent with the same mode of embodiment 4-2, but with 0.1 part molecular weight be about 10,000 poly sodium replace 0.001 part (S, S)-N, N ,-two (1,2-dicarboxyl ethyl)-ethylenediamine trisodiums.The performance evaluation of final water absorbing agent (E4-6) the results are shown in table 4-1.
Embodiment 4-7
According to obtaining a kind of water absorbing agent, but with 0.01 part N with the same mode of embodiment 4-2,0.001 part of N-two carboxymethyl-L-glutamic acid four sodium replacement (S, S)-N, N '-two (1,2-dicarboxyl ethyl)-ethylenediamine trisodium.The performance evaluation of final water absorbing agent (E4-7) the results are shown in table 4-1.
Embodiment 4-8
According to obtaining a kind of water absorbing agent with the same mode of embodiment 4-2, but with (R, S)-N, N '-two (1,2-dicarboxyl ethyl)-ethylenediamine tetraacetic sodium replace 0.001 part (S, S)-N, N ,-two (1,2-dicarboxyl ethyl)-ethylenediamine trisodiums.The performance evaluation of final water absorbing agent (E4-8) the results are shown in table 4-1.
Comparative example 4-2
According to obtaining a kind of relatively water absorbing agent with the same mode of embodiment 4-2, but with 0.001 part of 0.01 part acetylacetone,2,4-pentanedione replacement (S, S)-N, N '-two (1,2-dicarboxyl ethyl)-ethylenediamine trisodium.The performance evaluation of final comparison water absorbing agent (R4-2) the results are shown in table 4-1.
Embodiment 4-9
To comprise 0.01 part of (S, S)-N, N '-two (1,2-dicarboxyl ethyl)-combination solution of ethylenediamine trisodium, 0.5 part of ethylene carbonate, 3 parts of water and 3 parts of isopropyl alcohols mixes as the water-absorbing resin (B) that obtains in the reference example 2 with 100 parts, the mixture that obtains was heated 50 minutes down at 190 ℃, obtain water absorbing agent thus.The performance evaluation of final water absorbing agent (E4-9) the results are shown in table 4-1.
Embodiment 4-10
According to obtaining a kind of water absorbing agent with the same mode of embodiment 4-9, but with 0.5 part 1,4-butanediol replacement ethylene carbonate.The performance evaluation of final water absorbing agent (E4-10) the results are shown in table 4-1.
Comparative example 4-3
According to obtaining a kind of relatively water absorbing agent with the same mode of embodiment 4-9, but do not add 0.01 part (S, S)-N, N '-two (1,2-dicarboxyl ethyl)-ethylenediamine trisodium.The performance evaluation of final comparison water absorbing agent (R4-3) the results are shown in table 4-1.
Comparative example 4-4
According to obtaining a kind of relatively water absorbing agent (R4-4) with the same mode of embodiment 4-10, but do not add 0.01 part (S, S)-N, N '-two (1,2-dicarboxyl ethyl)-ethylenediamine trisodium.The performance evaluation of final comparison water absorbing agent (R4-4) the results are shown in table 4-1.
Embodiment 4-11
At first, the water absorbing agent that 2g is obtained in embodiment 4-2 (E4-2) homodisperse and be clipped in two-layer wood pulp sheet (heavy 150g/m 2, density 0.1g/cm 3, size 200mm * 140mm) middle obtains an adsorbing material like this.This adsorbing material is placed in the middle of a polyethylene film sheet and the polypropylene non-woven fabric sheet, obtain a body fluid absorbent articles thus.
Then, the artificial urine that 100g is contained the L-ascorbic acid of 0.005% concentration is poured on the nonwoven cloth cover of described body fluid absorbent articles, makes its absorption.This body fluid absorbent articles was left standstill 8 hours at 37 ℃, be placed on the nonwoven cloth cover of described body fluid absorbent articles the tissue layer of ten 23cm * 23cm is folded then.Impose 40g/cm 2Pressure 1 minute, measure by the amount of the adsorbed artificial urine of napkin, as the amount of taking off absorption.In addition, the state of the final swell gel that detects by an unaided eye, with zero, △, * three grades of destroyed states of estimating gel.The results are shown in table 4-2.
Comparative example 4-5
According to obtaining a kind of relatively body fluid absorbent articles, but replace water absorbing agent (E4-2) with water absorbing agent (R4-1) relatively with the same mode of embodiment 4-11.The evaluation result of final comparison body fluid absorbent articles is listed in table 4-2.
Comparative example 4-6
According to obtaining a kind of relatively body fluid absorbent articles, but replace water absorbing agent (E4-2) with water absorbing agent (R4-2) relatively with the same mode of embodiment 4-11.The evaluation result of final comparison body fluid absorbent articles is listed in table 4-2.
Table 4-1
Embodiment number Water absorbing agent number Water absorption (g/g) Water absorption under the load (g/g) The solubles content that removes (%) Destroyed and remove solubles content (%)
Embodiment 4-1 E4-1 34 29 11 13
4-2 E4-2 34 28 11 13
4-3 E4-3 34 28 11 11
4-4 E4-4 34 28 11 18
4-5 E4-5 34 28 11 14
4-6 E4-6 34 28 11 20
4-7 E4-7 34 28 11 21
4-8 E4-8 34 28 11 13
4-9 E4-9 28 22 11 11
4-10 E4-10 28 24 11 12
Comparative example 4-1 R4-1 34 28 11 25
4-2 R4-2 34 28 11 26
4-3 R4-3 28 22 11 26
4-4 R4-4 28 23 11 26
Table 4-2
Water absorbing agent number Take off adsorbance (g) Swell gel state (note 1)
Embodiment 4-11 E4-2 1 ○
Comparative example 4-5 R4-1 6 △
Comparative example 4-6 R4-2 8 ×
(note 1) zero: swell gel keeps shape.
△: swell gel partly is out of shape.
*: the swell gel distortion also is fluid state.
Under the prerequisite that does not break away from thought of the present invention and scope, can change various details of the present invention.And the front is to the description of the preferred embodiment of the invention, only is in order to reach illustrational purpose, rather than in order to limit the present invention who is limited by accompanying Claim book and equivalent thereof.

Claims (16)

1. water absorbing agent is by comprising the method acquisition that adds at least a step that is selected from the chemical compound of general formula (1) and (2) and the chelating agen that maleic acid is hydrophilic polymer (comprising salt) (3) in water-absorbing resin,
Its formula of (1) is:
Figure A2007101674090002C1
Wherein: n, X 1, and R 1～R 3Representative is column of figure and structure down:
n＝0，1
X 1＝COOM 1(M 1＝H，Na，K，NH 4)
R 1＝H，OH，Me
R 2＝H，-CH 2COOM 2，-CH 2CH 2COOM 2(M 2＝H，Na，K，NH 4)
R 3＝-CH 2COOM 3，-CH 2CH 2COOM 3，
Figure A2007101674090002C2
(M 3＝H，Na，K，NH 4)(R 4＝H，OH，Me)
General formula wherein (2) is;
Wherein: m, X 2, and R 5～R 8Representative is column of figure and structure down:
m＝0，1
X 2＝COOM 4(M 4＝H，Na，K，NH 4)
R 5＝H，OH，Me
R 6＝H，-CH 2COOM 5，-CH 2CH 2COOM 5(M 5＝H，Na，K，NH 4)
R 7＝H，-CH 2COOM 6，-CH 2CH 2COOM 6(M 6＝H，Na，K，NH 4)
R 0＝-CH 2COOM 7，-CH 2CH 2COOM 7，
Figure A2007101674090003C1
(M 7＝H，Na，K，NH 4)(R 9＝H，OH，Me).。
2. according to the water absorbing agent of claim 1, wherein in 100 parts of (weight) water-absorbing resins, add the chelating agen of 0.00001～30 part (weight).
3. according to the water absorbing agent of claim 1 or 2, wherein said water-absorbing resin is surface-crosslinked, and the absorbability to physiological sodium chloride solution is at least 20g/g under the load of 0.7psi.
4. according to each water absorbing agent among the claim 1-3, wherein said water-absorbing resin can be the monomeric polymerization and crosslinked the obtaining of acrylic acid and/or its salt by main component, and described monomer contains 30mol% or lower other monomer except that acrylic acid and/or its salt, and has 25 weight % or lower water-soluble substance amount.
5. according to each water absorbing agent among the claim 1-4, wherein said water-absorbing resin is 30g/g or higher in the absorbability under non-loaded.
6. according to each water absorbing agent among the claim 1-5, the water content of wherein said water-absorbing resin is 1～40%, and described water content is to obtain by the weight of measuring described water-absorbing resin at 105 ℃ of described water-absorbing resins of heating before and after 3 hours respectively.
7. according to each water absorbing agent among the claim 1-6, the average particulate diameter of wherein said water absorbing resin particle is 150～500 microns.
8. according to each water absorbing agent among the claim 1-7, the chelating agen of its formula of (1) is be selected from following material at least a: N-carboxymethyl asparagic acid, N, N-two carboxymethyl asparagic acids, N-carboxyethyl aspartic acid, N, N-two carboxyethyl aspartic acids, N-(1,2-two carboxyethyls)-aspartic acid, N-(1,2-dicarboxyl-2-hydroxyethyl)-aspartic acid, N-carboxymethyl-2-hydroxyl-aspartic acid, N, N-two carboxymethyls-2-hydroxyl-aspartic acid, N-carboxyethyl-2-hydroxyl-aspartic acid, N-(1,2-two carboxyethyls)-and 2-hydroxyl-aspartic acid, N-carboxymethyl glutamic acid, N, N-two carboxymethyl glutamic acid, N-carboxyethyl glutamic acid, N, N-two carboxyethyl glutamic acid, N-(1,2-two carboxyethyls)-and glutamic acid, N-(1,2-dicarboxyl-2-hydroxyethyl)-glutamic acid, with their sodium, potassium and ammonium salt.
9. according to each water absorbing agent among the claim 1-8, the chelating agen of its formula of (2) is be selected from following material at least a: N, N '-two (1,2-two carboxyethyls)-1, the 2-ethylenediamine, N, N '-two (1,2-dicarboxyl-2-hydroxyethyl)-1, the 2-ethylenediamine, N, N '-two (1,2-two carboxyethyls)-and N, N '-dicarboxyl methyl isophthalic acid, 2-ethylenediamine, N, N '-two (1,2-dicarboxyl-2-hydroxyethyl)-N, N '-dicarboxyl methyl isophthalic acid, 2-ethylenediamine and their sodium, potassium and ammonium salt.
10. according to each water absorbing agent among the claim 1-9, wherein chelating agen is a general formula
At least a in the chelating agen of chelating agen (1) and general formula (2).
11. according to each water absorbing agent among the claim 1-10, wherein chelating agen is be selected from following material at least a: N-(1,2-dicarboxyl-2-hydroxyethyl)-aspartic acid, N, N '-two (1,2-two carboxyethyls)-and 1, N, N '-two (1,2-dicarboxyl-2-hydroxyethyl)-1 and their sodium, potassium and ammonium salt.
12. according to each water absorbing agent among the claim 1-11, wherein said water absorbing agent can generate in the aqueous solution of unsaturated vinyl monomer of described water-absorbing resin and obtains by chelating agen being added to water-soluble polymerizable, and wherein the amount of the chelating agen of Jia Ruing is per 100 parts of (weight) monomer solid content with 0.00001～1 part (weight).
13. according to each water absorbing agent among the claim 1-11, wherein said water absorbing agent can obtain by chelating agen being added in the hydrogel that solid content is 20～90% (weight), this hydrogel can be obtained by the unsaturated vinyl monomer polymerization that water-soluble polymerizable generates water-absorbing resin, and wherein the amount of the chelating agen of Jia Ruing is that the hydrogel solid content of per 100 parts (weight) is with 0.00001～30 part (weight).
14. according to each water absorbing agent among the claim 1-11, wherein said water absorbing agent can be by obtaining chelating agen with containing to join in the described water-absorbing resin with the surface crosslinking agent of two or more functional groups of functional group reactions on the described water-absorbing resin, and wherein the amount of the chelating agen of Jia Ruing is that the water-absorbing resin solid constituent of per 100 parts (weight) is with 0.0001～10 part (weight).
15. according to each water absorbing agent among the claim 1-11, wherein said water absorbing agent can be by obtaining in the water-absorbing resin that joins chelating agen and water surface-crosslinked.
16. body fluid absorbent articles comprises each described water absorbing agent among the claim 1-15.
CNA2007101674092A 1998-03-03 1999-03-03 Water-absorbing agent and body liquid absorbing production Pending CN101143229A (en)

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JPS59230046A (en) * 1983-06-13 1984-12-24 Kuraray Co Ltd Water-absorbing composite and its production
JPH0643500B2 (en) * 1985-12-04 1994-06-08 住友精化株式会社 Granulation method of water absorbent resin
JPS63146964A (en) 1986-08-22 1988-06-18 Kao Corp Water-absorbing resin composition for throwaway diaper
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CN107739184A (en) * 2017-09-29 2018-02-27 安徽德全新型建材科技有限公司 A kind of styrofoam maturing agent
CN109080993A (en) * 2018-08-16 2018-12-25 闫大勇 A kind of sodium hydroxide damp-proof storage facilities
CN110608972A (en) * 2019-10-21 2019-12-24 中国地质科学院岩溶地质研究所 Direct type soil moisture content check out test set
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