JP2015101597A - Water-absorbing resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-absorbing resin containing a chelating agent which can absorb blood while suppressing coagulation of blood for medical applications or the like.SOLUTION: There is provided a water-absorbing resin containing a chelating agent in a polysaccharide crosslinked material. The polysaccharide preferably is a cellulose derivative, and the cellulose derivative preferably is a carboxymethyl cellulose. The chelating agent preferably is a compound selected from an organic carboxylic acid, an aminocarboxylic acid and a salt thereof and preferably contains one or more of lactic acid (a salt thereof), malic acid (a salt thereof), oxalic acid (a salt thereof), citric acid (a salt thereof), malonic acid (a salt thereof), succinic acid (a salt thereof) and glycine.

Description

  The present invention relates to a water absorbent resin that absorbs blood. More specifically, the present invention relates to a water-absorbing resin containing a chelating agent that can absorb blood while suppressing blood coagulation.

  The water-absorbent resin absorbs several tens to several hundred times as much water as its own weight. Polyacrylic acid cross-linked products are mainly used, and are widely used in sanitary products such as paper diapers and sanitary products, civil engineering, food, and agriculture. As for the performance of the water-absorbent resin, improvement of water-absorbing properties has been studied mainly for urine, seawater, and water. It is known that the water-absorbing resin has a reduced water absorption in an aqueous solution containing an electrolyte, and it has been studied to maintain the water absorption even in an aqueous solution containing an electrolyte. For example, a cellulose derivative having high water absorption even in an aqueous electrolyte solution has been studied (Patent Document 1). Several studies have been made on water-absorbent resins for menstrual blood (Patent Documents 2 to 3). For example, the degree of neutralization of crosslinked acrylic acid has been studied so that hemoglobin in blood cells is less likely to adhere (Patent Document 2). In addition, as a water-absorbent crosslinked body that absorbs highly viscous body fluid such as menstrual blood, a polymer containing alkoxysilane has been studied (Patent Document 3).

On the other hand, as chelating agents, absorbent materials containing chelating agents have been studied for the purpose of deodorization, antibacterial properties, suppression of deterioration in performance over time, and prevention of coloring (Patent Documents 4 to 7). For example, it has been studied to include a chelating agent having a hydrophobic part and a hydrophilic part in a water-absorbing resin to prevent deterioration due to decomposition of the water-absorbing resin and maintain water absorption (Patent Document 4).
However, the water-absorbing resin that absorbs blood has not been studied for the problem of blood coagulation. For this reason, there has been a demand for a highly water-absorbing resin having high water absorption for blood containing electrolytes and proteins while suppressing blood coagulation when water is absorbed for medical purposes.

JP 2008-280429 A JP 2010-17536 A JP 2009-270039 A JP 08-52203 A JP 2000-350744 A JP 2006-57075 A International Publication No. 2009/005114

Menstrual blood that absorbs water for use as a sanitary product has not been studied for coagulated blood because it is difficult to coagulate blood. In addition, blood is coagulated in medical applications and the like, making it difficult to absorb blood. Furthermore, since blood contains electrolytes and proteins, there is a need for a water-absorbing resin that is less susceptible to these effects and that has high water absorption while suppressing blood coagulation.
An object of the present invention is to provide a water-absorbing resin containing a chelating agent that can absorb blood while suppressing blood coagulation in medical applications and the like.

  As a result of extensive studies, the present inventors have found a water-absorbing resin containing a chelating agent that can absorb blood while suppressing blood coagulation, and have completed the present invention.

  That is, the present invention relates to [1] a water-absorbing resin containing a chelating agent in a crosslinked polysaccharide.

The present invention also relates to the water absorbent resin according to the above [1], wherein the [2] polysaccharide is a cellulose derivative.
The present invention also relates to the water absorbent resin according to the above [2], wherein the [3] cellulose derivative is carboxymethyl cellulose.

  The present invention also relates to the water absorbent resin according to any one of the above [1] to [3], wherein the [4] chelating agent is a compound selected from organic carboxylic acids, aminocarboxylic acids and salts thereof.

  In the present invention, [5] the chelating agent is lactic acid (salt), malic acid (salt), oxalic acid (salt), citric acid (salt), malonic acid (salt), succinic acid (salt), glycine. It is related with the water absorbing resin in any one of said [1]-[4] containing 1 or more of them.

  Furthermore, this invention relates to the water absorbing resin in any one of said [1]-[5] whose quantity of a [6] chelating agent is 0.00001-30 mass%.

  According to the water-absorbing resin of the present invention, it is possible to provide a water-absorbing resin containing a chelating agent that can absorb blood while suppressing blood coagulation.

  The present invention is a water-absorbing resin containing a chelating agent that can absorb blood while suppressing blood coagulation.

The water-absorbing resin may be any water-absorbing resin containing an anionic functional group such as a carboxyl group or a sulfone group. In the present invention, a water-absorbing resin obtained by crosslinking a polysaccharide is used. In the present invention, a water absorbent resin synthesized from a mixture containing a monomer containing an anionic functional group and a crosslinking agent, or a water absorbent resin obtained by crosslinking a polymer such as a synthetic polymer can be used in combination. These resins may be used alone or in combination.
In the synthesis of a water-absorbing resin from a monomer that can be used in combination, it can be obtained by reacting a mixture containing an unsaturated monomer having an anionic functional group and a crosslinking agent. Examples of the monomer having an anionic functional group include acrylic acid and vinyl sulfonic acid. Examples of the synthetic polymer include a resin obtained by crosslinking a copolymer of polyvinyl alcohol and polyacrylic acid or a mixture of polyvinyl alcohol and polyacrylic acid. In addition to these resins, polymers containing other functional groups may be included.

  Examples of the polysaccharide used in the present invention include polysaccharides, polysaccharide derivatives thereof, and alkali metal salts such as sodium salts and potassium salts thereof, but are not limited thereto. Examples of polysaccharides and polysaccharide derivatives include cellulose, methylcellulose, ethylcellulose, cellulose nitrate, cellulose sulfate, cellulose acetate, hydroxymethylcellulose, cationized cellulose, hydroxyethylcellulose, hydroxypropylcellulose, ethylhydroxycellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, carboxy Ethylcellulose, gum arabic, guar gum, locust bean gum, pectin, tragacanth, corn starch, xanthan gum, dextrin, gelatin, casein, sodium chondroitin sulfate, starch, oxidized starch, acetylated starch, phosphorylated starch, agar, carrageenan, alginic acid, hyaluron Examples include sodium acid. These sodium salts and potassium salts are also included. In particular, carboxymethylcellulose is preferable.

  As carboxymethylcellulose, the polymerization degree is preferably 50 to 2000, more preferably 200 to 1000, and still more preferably 300 to 900. The degree of substitution is preferably 0.1 to 2.8, more preferably 0.3 to 1.4, and even more preferably 0.5 to 1.1. If the degree of substitution is less than 0.1, the water absorption decreases. When the degree of substitution exceeds 2.8, the degree of crosslinking decreases.

Examples of the crosslinking agent include polyvalent epoxy compounds having two or more functional groups, polyvalent aldehydes, polyvalent carboxylic acids, polyvalent vinyls, polyvalent acrylates, polyvalent methacrylates, polyvalent halogens and the like. Substances having different functional groups such as epichlorohydrin and glycidyl methacrylate can also be used. It is not limited to this.
For example, polyhydric epoxy compounds such as ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol polyglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and polyhydric aldehydes such as glutaraldehyde, glyoxal and terephthalaldehyde , Malic acid, citric acid, tartaric acid, polyacrylic acid, maleic acid, polyvalent carboxylic acids such as succinic acid, polyvalent vinyls such as divinylsulfone, polyvalent acrylates such as polyethylene glycol diacrylate, polyethylene glycol dimethacrylate Examples thereof include, but are not limited to, polyvalent methacrylates such as haloepoxies such as epichlorohydrin, and polyvalent halogens. In particular, ethylene glycol diglycidyl ether is preferred.

  The water absorption amount of the water-absorbent resin is preferably 30 g / g or more with respect to 1 g of the water-absorbent resin, with respect to 1 g of the physiological saline (NaCl 0.9 w / v%). If the amount of water absorption is less than 30 g / g, the amount of water-absorbing resin used is increased, which is not preferable. 40 g / g or more is more preferable, and 60 g / g or more is more preferable. The upper limit of the water absorption amount is not particularly limited, but is preferably 3000 g / g or less because the strength of the gel is reduced and the handleability during water absorption is deteriorated.

  As the chelating agent, any water-soluble compound that forms a chelate with calcium ions necessary for blood coagulation can be applied. For example, acetic acid, propionic acid, lactic acid, malic acid, citric acid, oxalic acid, malonic acid, succinic acid, polyacrylic acid and other organic carboxylic acids and their salts, ethylenediaminetetraacetic acid (EDTA), ethylenediamine disuccinic acid (EDDS) ), Nitrilotriacetic acid (NTA), diethylenetriaminepentaacetic acid (DTPA), hydroxyethylethylenediaminetriacetic acid (HEDTA), triethylenetetraaminehexaacetic acid (TTHA), pentadiaminetetraacetic acid (PDTA), hydroxyethyliminodiacetic acid (HIDA) ), Dihydroxyethyl glycine (DHEG), glycol ether diamine tetraacetic acid (GEDTA), dicarboxymethyl glutamic acid (CMGA), glycine, aminocarboxylic acids such as various amino acids, hydroxyethylidene diphosphonic acid (HEDP) Nitrilotris (methylene phosphoric acid) (NTMP), phosphono butane tricarboxylic acid (PBTC), ethylene diamine tetra (methylene phosphoric acid) (EDTMP) and organic phosphoric acid, organic sulfonic acids and their salts such as heparin. Lactic acid (salt), malic acid (salt), oxalic acid (salt), citric acid (salt) from the viewpoint of ease of dispersion of chelating agent from the water-absorbent resin into the blood, safety, and odor during use Malonic acid (salt), succinic acid (salt), and glycine are preferable.

  The amount of the chelating agent added can be 0.00001 to 30% by mass ratio with respect to the water-absorbent resin. 0.0001 to 10% is preferable, and 0.0005 to 5% is more preferable. If it is less than 0.00001%, the effect of preventing coagulation of blood is low, and if it exceeds 30%, the effect is low with respect to the added amount.

  The chelating agent can be added by adding and kneading the water-absorbing resin before cross-linking, when water-absorbing an aqueous solution containing the chelating agent after cross-linking the water-absorbing resin, or by spraying or dropping the chelating agent on the surface of the water-absorbing resin. It can be added to the water-absorbent resin by attaching an agent.

A chelating agent can be arrange | positioned at the inside of a water absorbing resin, the surface, and a surface layer.
When a chelating agent is disposed inside the water-absorbent resin, it does not peel off during handling and is easy to handle, but the coagulation inhibiting effect is low.
When arranged on the surface of the water-absorbent resin, the solubility in blood is high and the blood coagulation inhibitory effect is high, but there is a concern that the gel may be lost when the gel is handled.
When arranged on the gel surface layer, the release effect into the blood is high, and the handleability and the blood coagulation inhibitory effect can both be achieved without peeling off during handling of the water-absorbent resin. Therefore, it is preferable to arrange a chelating agent on the surface layer of the water absorbent resin. With the surface layer of a water absorbing resin, let the area | region from the surface to 500 micrometers be a surface layer. As arrangement | positioning of a chelating agent, the surface layer of 250 micrometers or less is preferable, and the surface layer of 100 micrometers or less is more preferable.

  Although a chelating agent can be added as a sodium salt or potassium salt, it can also be made into a salt by neutralizing after adding a chelating agent. When the water absorbent resin is synthesized under alkaline conditions, it can be used as a neutralizing agent.

  Hereinafter, the present invention will be described based on examples. However, the present invention is not limited to the following examples.

Example 1
28.3 g of carboxymethylcellulose (polymerization degree 750, substitution degree 0.75) as a polysaccharide was dissolved in 255 mL of a 1.5 M aqueous sodium hydroxide solution. To this aqueous solution, 5.23 g of ethylene glycol diglycidyl ether was added as a crosslinking agent, and the mixture was stirred and mixed at 30 ° C. for 2 hours. Then, it was made to heat and gelatinize by leaving still at 60 degreeC for 6 hours, and the polysaccharide crosslinked body was obtained. This gel was pulverized to an appropriate size. The crushed gel was immersed in 600 mL of methanol for 3 hours to remove the methanol. Then, the gel was swollen with 100 mL of 1.0 mM hydrochloric acid aqueous solution. Again, the crushed gel was immersed in 600 mL of methanol for 3 hours to remove the methanol. This operation was repeated twice. Then, 10 mL of 10 mM trisodium citrate aqueous solution was sprayed as a chelating agent and dried at 50 ° C. for 3 hours in a vacuum dryer. This was pulverized and classified with a sieve having an opening of 150 to 300 μm to obtain a superabsorbent resin containing a chelating agent in the polysaccharide cross-linked product.
Using this highly water-absorbent resin, the water absorption capacity of defibrillated horse blood, the water absorption capacity of coagulable horse blood, and the blood coagulation inhibitory effect (blood coagulation time) shown below were evaluated, and the results are shown in Table 1. .

(Water absorption ratio of defiberized horse blood)
3 mL of defibrillated horse blood (Japan Biotest Laboratories Co., Ltd.) was placed on an acrylic plate (10 × 10 cm), 0.1 g (A) of a water absorbent resin was added, and allowed to stand for 10 minutes. Place two sheets of filter paper (Advantech Toyo Co., Ltd. No. 2, 10 × 10 cm), invert the water-absorbent resin on the filter paper, remove the acrylic plate, and stack two more filter papers on it. The blood that has not been absorbed is absorbed by the filter paper. The water-absorbing resin was collected from the filter paper, the weight (B) was measured, and the water absorption capacity of the defibrinated horse blood was determined by the following formula (1).

Horse blood absorption ratio [g / g-polymer] = (BA) / A (1)

(Blood coagulation inhibitory effect)
Coagulated horse blood was prepared by adding 0.225 mL of 0.2 M calcium chloride solution to 3 mL of sodium citrate-treated horse blood (manufactured by Nippon Biotest Laboratories, Inc.). The prepared horse blood was kept at 38 ° C., and after 10 minutes, 0.1 g of a water absorbent resin was added and left standing. Thereafter, the time until the horse blood solidified into a gel was measured. The anticoagulant effect was evaluated as “◯” when the time to coagulation was 20 minutes or more, “Δ” when 10 minutes to 20 minutes, and “X” when 10 minutes or less.

(Water absorption rate of coagulating horse blood)
0.25 mL of 0.2 M calcium chloride solution was added to 3 mL of equine blood treated with sodium citrate (manufactured by Japan Biotest Laboratories) to obtain coagulable equine blood. 3 mL of horse blood prepared on a 38 ° C. hot plate was kept warm for 10 minutes, 0.1 g (C) of a water absorbent resin was added, and the mixture was allowed to stand at 38 ° C. for 10 minutes. Remove the coagulated blood, place a water-absorbing resin on two stacked filter papers (Advantech Toyo Co., Ltd., No. 2, 10 × 10 cm), and then stack two more filter papers on top of each other, and hold it lightly with your hand. Unabsorbed blood was absorbed into the filter paper. The water absorbent resin was collected from the filter paper, the weight (D) was measured, and the water absorption capacity of the coagulable horse blood was determined by the following formula (2).

Water absorption ratio of coagulable horse blood [g / g-polymer] = (DC) / C (2)

(Example 2)
28.4 g of carboxymethylcellulose (polymerization degree 750, substitution degree 0.75) was dissolved in 255 mL of a 1.5 M aqueous sodium hydroxide solution. To this aqueous solution, 5.23 g of ethylene glycol diglycidyl ether was added and mixed with stirring at 30 ° C. for 2 hours. Thereafter, the mixture was allowed to stand at 60 ° C. for 6 hours to be heated and gelled. This gel was pulverized to an appropriate size. The crushed gel was immersed in 600 mL of methanol for 3 hours to remove the methanol. Then, the gel was swollen with 100 mL of 1.0 mM citric acid aqueous solution. Again, the crushed gel was immersed in 600 mL of methanol for 3 hours to remove the methanol. This operation was repeated twice. Then, it was made to dry at 50 degreeC with the vacuum dryer for 3 hours. This was pulverized and classified with a sieve having an opening of 150 to 300 μm to obtain a superabsorbent resin containing a chelating agent in the polysaccharide cross-linked product.
In the same manner as in Example 1, the water absorption rate of defibrinated horse blood, the water absorption rate of coagulable horse blood, and blood coagulation inhibitory effect (blood coagulation time) were evaluated. The results are shown in Table 1.

(Comparative Example 1)
Without using the trisodium citrate used in Example 1, a superabsorbent resin composed of a crosslinked polysaccharide was prepared.
In the same manner as in Example 1, the water absorption rate of defibrinated horse blood, the water absorption rate of coagulable horse blood, and blood coagulation inhibitory effect (blood coagulation time) were evaluated. The results are shown in Table 1.

(Comparative Example 2)
Using a polyacrylic acid crosslinked product (manufactured by Wako Pure Chemical Industries, Ltd.), in the same manner as in Example 1, the water absorption capacity of defibrillated horse blood, the water absorption capacity of coagulable horse blood, and blood coagulation inhibitory effect (blood coagulation) Time) and the results are shown in Table 1.

In horse blood defibrillated with antibacterial glass beads and anticoagulated, the water absorption is about 20 times that of Examples 1 and 2 containing a chelating agent, which is the same as that without adding the chelating agent of Comparative Example 1. However, the water absorption is about twice that of the comparative example 2 using the crosslinked polyacrylic acid. On the other hand, in coagulable horse blood adjusted so as to coagulate in the same manner as normal blood, Comparative Example 1 containing no chelating agent has a water absorption capacity that is about twice that of Comparative Example 2 using a crosslinked polyacrylic acid. However, in Examples 1 and 2 containing a chelating agent, the water absorption was 15.9 to 16.1 times and about 3 times or more.
Moreover, when a chelating agent is contained, the time until coagulation of coagulable horse blood becomes longer, and it can be seen that coagulation is further suppressed by the presence of the chelating agent on the surface side of the water absorbent resin.

Claims (6)

  A water-absorbent resin containing a chelating agent in a crosslinked polysaccharide.   The water-absorbent resin according to claim 1, wherein the polysaccharide is a cellulose derivative.   The water-absorbent resin according to claim 2, wherein the cellulose derivative is carboxymethyl cellulose.   The water-absorbent resin according to any one of claims 1 to 3, wherein the chelating agent is a compound selected from organic carboxylic acids, aminocarboxylic acids, and salts thereof.   The chelating agent comprises at least one of lactic acid (salt), malic acid (salt), oxalic acid (salt), citric acid (salt), malonic acid (salt), succinic acid (salt), and glycine. The water-absorbent resin according to any one of -4.   The water-absorbent resin according to any one of claims 1 to 5, wherein the amount of the chelating agent is 0.00001 to 30% by mass.