WO2024116863A1

WO2024116863A1 - Absorbent article

Info

Publication number: WO2024116863A1
Application number: PCT/JP2023/041200
Authority: WO
Inventors: 久孝七海; 牧子岩本
Original assignee: ユニ・チャーム株式会社
Priority date: 2022-11-30
Filing date: 2023-11-16
Publication date: 2024-06-06

Abstract

The purpose of the present disclosure is to provide an absorbent article wherein nattokinase is not readily affected by a low-viscosity liquid, demonstrates superior action against blood clots, and does not readily act on skin. An absorbent article according to the present disclosure has the following configuration.　An absorbent article that is provided with a functional composition, said functional composition including a functional substance (A) that includes nattokinase and has a function of inhibiting a factor that contributes to blood coagulation, and a water-soluble polymer (B), said absorbent article being characterized in that at least a portion of the nattokinase is not bonded to the water-soluble polymer (B).

Description

Absorbent articles

This disclosure relates to absorbent articles.

Absorbent articles having functional compositions for breaking down blood clots (e.g., menstrual blood) are being studied. This makes it possible to reduce the viscosity of blood clots on the absorbent article, making it easier for the absorbent article to absorb the reduced-viscosity blood clots.

For example, Patent Document 1 proposes an absorbent personal care article that includes at least one layer, the layer including a support having a treatment agent applied thereto, the treatment agent including a bound enzyme.

Paragraph [0004] of Patent Document 1 discloses that "The use of conjugated enzymes can reduce skin or mucosal sensitization in the event that the conjugated enzyme migrates into the user's body, as compared to unmodified enzymes. Furthermore, the conjugated enzymes are less likely to migrate from the treated material to the user, thereby reducing the risk of sensitization to users of absorbent products containing the conjugated enzymes."

JP 2007-535361 A

In the absorbent article disclosed in Patent Document 1, the enzyme is bound to a carrier material, which allows the enzyme to reduce skin sensitization of the user and is less susceptible to the effects of low-viscosity liquids; however, the enzyme cannot function sufficiently with menstrual secretions.
Therefore, an object of the present disclosure is to provide an absorbent article in which nattokinase is less susceptible to the effects of low-viscosity liquids, has excellent effects on blood clots, and is less likely to affect the skin.

The present inventors have discovered an absorbent article that includes a functional composition containing a functional substance (A) that has the function of inhibiting factors that act on blood clotting, including nattokinase, and a water-soluble polymer (B), and that is characterized in that at least a portion of the nattokinase is not bound to the water-soluble polymer (B).

The absorbent article according to the present disclosure includes a functional composition containing nattokinase, which is less susceptible to the effects of low-viscosity liquids, has excellent effects on blood clots, and is less likely to affect the skin.

Specifically, the present disclosure relates to the following aspects:
[Aspect 1]
An absorbent article comprising a functional composition containing a functional substance (A) having a function of inhibiting a blood coagulation factor, including nattokinase, and a water-soluble polymer (B),
At least a portion of the nattokinase is not bound to the water-soluble polymer (B);
The absorbent article as described above.

In the above absorbent article, the functional substance (A) having the function of inhibiting blood clotting factors is held by the water-soluble polymer (B) in the functional composition. When the functional composition comes into contact with a low-viscosity liquid, it takes a certain amount of time for the water-soluble polymer (B) to dissolve. This means that the functional substance (A) having the function of inhibiting blood clotting factors, particularly nattokinase, is less likely to flow out of the functional composition, and the functional substance (A) having the function of inhibiting blood clotting factors, particularly nattokinase, is less likely to be affected by low-viscosity liquids.

Furthermore, when the functional composition comes into contact with a blood clot, nattokinase dissolves from the functional composition, and the nattokinase decomposes fibrin in the blood clot, thereby reducing the viscosity of the blood clot. Furthermore, at least a portion of the nattokinase is not bound to the water-soluble polymer (B), i.e., is in a free state, and therefore the nattokinase in the free state can efficiently decompose fibrin in the blood clot, thereby efficiently reducing the viscosity of the blood clot.

Furthermore, in the above-mentioned functional composition, although a portion of the nattokinase is in a free state, the nattokinase in the free state is unlikely to act on the skin of a user of the article.
As described above, in the absorbent article, nattokinase is less affected by low viscosity liquids, has excellent effects on blood clots, and is less likely to act on the skin.

[Aspect 2]
The absorbent article according to aspect 1, wherein the functional substance (A) having a function of inhibiting a factor acting on blood coagulation contains more than 50% by mass of the nattokinase.
In the above absorbent article, the functional substance (A) having the function of inhibiting factors that act on blood coagulation contains a predetermined amount of nattokinase, so that in the above absorbent article, nattokinase is less affected by low-viscosity liquids, has excellent action on blood coagulation, and is less likely to act on the skin.

[Aspect 3]
The absorbent article according to aspect 1 or 2, wherein the functional composition contains a functional substance (A) having a function of inhibiting a factor acting on blood coagulation and a water-soluble polymer (B) in a mass ratio of 5:95 to 95:5 based on 100 parts by mass of the total solid content of the functional substance (A) having a function of inhibiting a factor acting on blood coagulation and the water-soluble polymer (B).

The functional composition contains a functional substance (A) that has the function of inhibiting factors that act on blood clotting, and a water-soluble polymer (B) in a specified mass ratio, so in the absorbent article, nattokinase is less affected by low-viscosity liquids, has excellent action against blood clots, and is less likely to act on the skin.

[Aspect 4]
The absorbent article according to any one of aspects 1 to 3, wherein the difference in solubility in water of the functional substance (A) having a function of inhibiting a factor acting on blood coagulation: a (% by mass) and the solubility in water of the water-soluble polymer (B): b (% by mass) is 0<(a-b).

In the absorbent article, the functional substance (A) that has the function of inhibiting factors that act on blood clotting has a water immersion solubility rate that is different from the water immersion solubility rate of the water-soluble polymer (B), so that the functional component in the absorbent article is less susceptible to the effects of low-viscosity liquids.

[Aspect 5]
The absorbent article according to any one of the preceding claims, wherein the water-soluble polymer (B) has a water immersion solubility of 5 to 70 mass %.

In the above absorbent article, the water-soluble polymer (B) has a predetermined water immersion solubility rate, so that nattokinase in the above absorbent article is less susceptible to the effects of low-viscosity liquids and has excellent action against blood clots.

[Aspect 6]
The absorbent article according to any one of claims 1 to 5, wherein the water-soluble polymer (B) has a viscosity of 9,000 mPa·s or less under the measurement conditions of a 10% by mass aqueous solution, a temperature of 20°C, a viscometer: a B-type viscometer, and a rotor rotation speed of 60 rpm.

In the absorbent article, since the water-soluble polymer (B) has a predetermined viscosity, the functional composition is unlikely to flow out even when it comes into contact with a low-viscosity liquid, and when the functional composition comes into contact with a blood clot, the functional substance (A), which has the function of inhibiting factors that act on blood clotting, is likely to diffuse into the blood clot.

[Aspect 7]
The absorbent article according to any one of the preceding claims, wherein the water-soluble polymer (B) comprises at least one of polyvinyl alcohol, polyethylene oxide, polyethylene glycol, and a water-soluble acrylic resin.

The above absorbent article is more likely to exhibit the effects of aspect 1 because the water-soluble polymer (B) contains a specific one.

[Aspect 8]
The absorbent article according to any one of aspects 1 to 7, wherein the absorbent article comprises a liquid-permeable top sheet including a nonwoven fabric, and the functional composition is disposed in the form of particles on the surface of the fibers constituting the nonwoven fabric, disposed so as to cover the fibers constituting the nonwoven fabric, or impregnated into the fibers constituting the nonwoven fabric.

In the absorbent article, the functional composition is arranged in a specific state, which makes it easier to achieve the effect of aspect 1.

[Aspect 9]
The absorbent article according to any one of aspects 1 to 8, wherein the absorbent article comprises a liquid-permeable top sheet including a perforated film, and the functional composition is disposed in the form of particles on the surface of the perforated film, or in the form of a film on the surface of the perforated film.

The absorbent article according to the present disclosure will be described in detail below.
Examples of absorbent articles according to the present disclosure include sanitary napkins, sanitary shorts, panty liners, and the like.

In the absorbent article according to the present disclosure, the functional composition includes a functional substance (A) having a function of inhibiting factors that act on blood clotting, including nattokinase, and a water-soluble polymer (B). In this specification, the "functional substance (A) having a function of inhibiting factors that act on blood clotting" may be simply referred to as the "functional substance (A)".
Nattokinase is a serine protease that exhibits high fibrin decomposition activity, and can promote the reduction of the viscosity of blood clots (e.g., menstrual blood) and inhibit blood coagulation.

Nattokinase is an enzyme (serine protease) that has the ability to degrade fibrin. Nattokinase is generally contained in natto and can be produced by Bacillus subtilis var. natto. Nattokinase can degrade fibrin mainly into DD (175 kDa) and LD (110 kDa). Without intending to be limited by theory, nattokinase has a three-dimensional structure suitable for degrading fibrin and is thought to degrade fibrin by a mechanism similar to that of plasmin. It has been reported that the specificity constant of nattokinase for fibrin is approximately six times that of plasmin. This indicates that nattokinase has a higher fibrinolytic activity than plasmin.

Without intending to be limited by theory, nattokinase exhibits particularly high activity at temperatures of 30-40°C and pH levels of 6-9. Absorbent articles, particularly sanitary napkins, reach a temperature of around 35°C due to body temperature when worn, and the pH of menstrual blood is around 7. Therefore, it is believed that nattokinase functions particularly well under the conditions in which absorbent articles are used to absorb menstrual blood.

In addition, without intending to be limited by theory, simulation results on the binding mode between fibrinogen and nattokinase suggest that nattokinase interacts with fibrinogen via its eight amino acid residues (Gly61, Ser63, Thr99, Phe189, Leu209, Tyr217, Asn218, Met222) and decomposes fibrin mainly via Ser221. By utilizing such detailed knowledge of the mechanism of action of nattokinase, it is believed that it is possible to further improve the blood coagulation inhibition effect and the viscosity reduction effect of blood clots in absorbent articles.

Nattokinase is highly safe for the human body. Therefore, when nattokinase is applied as a functional substance to absorbent articles, the safety is particularly excellent.
Nattokinase is commercially available in the form of a powder, for example. For example, Nattokinase (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) with a granular size of 15 to 35 μm is commercially available.

The functional substance (A) contains nattokinase in an amount of preferably more than 50% by mass, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass or more. This can promote low viscosity of blood clots and inhibit blood coagulation. The upper limit of nattokinase in the functional substance (A) is 100% by mass.

The functional substance (A) may contain a functional substance other than nattokinase that has a function of inhibiting factors that act on blood coagulation.
Examples of the factors that act on blood coagulation include fibrin (particularly fibrin monomer, fibrin polymer, and/or stabilized fibrin), blood coagulation factors, platelets, and platelet aggregation promoters. Examples of blood coagulation factors include thrombin, activated factor II, activated factor VII, activated factor IX, activated factor X, and activated factor XIII. Examples of platelet aggregation promoters include TXA2 and cAMP.

Functional substances that have the function of inhibiting factors that act on blood clotting include enzymes with fibrin decomposition ability, substances (particularly compounds) with antiplatelet activity, factors that promote the activation of plasmin, and coagulation inhibitors.

The above-mentioned enzymes with fibrinolytic properties and factors that promote the activation of plasmin mainly have the effect of promoting the reduction of the viscosity of blood clots. In addition, substances with antiplatelet properties and coagulation inhibitors mainly have the function of suppressing blood coagulation.

The fibrin decomposition enzyme may be a protease, in particular a serine protease or a cysteine protease. The fibrin decomposition enzyme is particularly capable of cleaving fibrin polymers and/or stabilized fibrin.

Without intending to be limited by theory, blood coagulation factors including a series of molecules act in blood to generate fibrin monomers from fibrinogen, polymerize the fibrin monomers, and crosslink (stabilize) the fibrin, resulting in blood clotting. Fibrin polymers and stabilized fibrin form a mesh-like structure, which aggregates red blood cells, platelets, etc., causing blood to clot. Enzymes with fibrin-decomposing ability can inhibit blood clotting by decomposing fibrin polymers and stabilized fibrin, in particular, and can also promote the reduction of the viscosity of blood clots by decomposing fibrin polymers and stabilized fibrin that have formed mesh-like structures.

In addition to nattokinase, other enzymes with fibrin decomposition ability include plasmin, DFE27, subtilisin DFE, subtilisin QK-2, bromelain, and serrapeptase.

The above-mentioned plasmin is an enzyme (serine protease) that has the ability to degrade fibrin (fibrinolytic ability) and is usually present in blood (e.g., menstrual blood). Plasmin can degrade fibrin. When plasmin degrades fibrin, a degradation product called D-dimer and other degradation products are generated.

DFE27 is an enzyme (serine protease) that has the ability to degrade fibrin. DFE27 is generally contained in Douchi and can be produced by B. subtilis DC27.

Subtilisin DFE is an enzyme (serine protease) that has the ability to degrade fibrin. Subtilisin DFE is generally contained in Douchi and can be produced by B. amyloliquefaciens DC-4.

Subtilisin QK-2 is an enzyme (serine protease) that has the ability to degrade fibrin. Subtilisin QK-2 is generally contained in fermented soybeans and can be produced by B. subtilis QK02.

Bromelain is an enzyme (cysteine protease) that has the ability to break down fibrin. Bromelain is found in pineapple fruits, etc.

Serrapeptase is an enzyme that has the ability to degrade fibrin. Serrapeptase is generally contained in silkworms and can be produced by the non-pathogenic bacterium Serratia marcescens E15.

The functional composition may further include an auxiliary component capable of improving the fibrin decomposition (fibrinolytic ability) of an enzyme having fibrin decomposition ability, for example, nattokinase.
The auxiliary ingredients include fatty acids having 12 to 18 carbon atoms, ground vegetables, EPA, DHA, spices, zinc ions (Zn ²⁺ ), manganese ions (Mn ²⁺ ), calcium ions (Ca ²⁺ ), and potassium ions (K ⁺ ).

Fatty acids with 12 to 18 carbon atoms can particularly improve the fibrinolytic ability of nattokinase. It is preferable to use fatty acids with 12 to 18 carbon atoms at a ratio of 4 to 12 mg/2000 FU relative to nattokinase.

Ground vegetables, EPA, and DHA, in particular, can improve the fibrinolytic ability of nattokinase. Ground vegetables include, for example, onion powder.
Spices, in particular, can improve the fibrinolytic ability of nattokinase, including chili peppers (especially in powder form).

Zinc ions (Zn ²⁺ ) can particularly improve the fibrinolytic ability of nattokinase, while manganese ions (Mn ²⁺ ), calcium ions (Ca ²⁺ ), and potassium ions (K ⁺ ) can particularly improve the fibrinolytic ability of douchi-derived protease.

The functional substance (A) may also contain a factor that promotes the activation of plasmin. Plasmin is usually present in menstrual blood and is capable of decomposing fibrin, so by using a factor that promotes the activation of plasmin, it is possible to promote the reduction of the viscosity of highly viscous menstrual blood. Factors that promote the activation of plasmin include factors that have the effect of inhibiting the activity of the lysis inhibitor PAI-1. An example of a factor that has the effect of inhibiting the activity of the lysis inhibitor PAI-1 is the above-mentioned nattokinase. Bromelain and DFE27 also have the effect of promoting the conversion of plasminogen to plasmin.

When the solubility-promoting factor t-PA is activated, plasmin is produced from plasminogen. t-PA is inactivated by binding to the solubility-inhibiting factor PAI-1. Without intending to be limited by theory, it is believed that the inactivation of t-PA is suppressed by inhibiting the activity of the solubility-inhibiting factor PAI-1, and thus the production of plasmin from plasminogen by t-PA is promoted. Plasmin is inactivated in the body by binding to a plasmin inhibitor (antiplasmin).

Examples of compounds with the above-mentioned antiplatelet effect include bromelain, acetylsalicylic acid (Aspirin (trademark), Bufferin (registered trademark), etc.), the PGI2 derivative beraprost, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and NO-related preparations (e.g., nitroglycerin, etc.). Other examples of compounds with antiplatelet effect include clopidogrel sulfate, prasugrel hydrochloride, ticlopidine hydrochloride, ticagrelor, cilostazol, and sarpogrelate hydrochloride.

Generally, when platelets are activated in the blood due to factors such as damage to the blood endothelium or contact with collagen, platelet aggregation occurs. Platelet aggregation is a reversible reaction. It is believed that blood coagulation can be inhibited by using compounds with antiplatelet activity.

Without intending to be limited by theory, it is believed that acetylsalicylic acid has the effect of irreversibly inactivating cyclooxygenase (COX), which acts to produce _TXA2 , a substance that promotes platelet aggregation, thereby exerting an antiplatelet effect.

Also, without intending to be limited by theory, it is believed that the PGI2 derivative beraprost inhibits platelet aggregation by increasing the synthesis of _PGI2 , a substance that inhibits platelet aggregation.

Furthermore, without intending to be limited by theory, it is believed that EPA and/or DHA produce _TXA3 from platelets, which does not have platelet aggregation activity, and as a result, platelet aggregation is inhibited.

Fibrin degradation products produced by fibrin-decomposing enzymes (especially nattokinase) also have the effect of inhibiting platelet aggregation. Fibrin degradation products produced by nattokinase include DD (175 kDa) and LD (110 kDa).

The functional substance (A) may also contain a coagulation inhibitor that has a fibrin production inhibitory effect. Examples of the coagulation inhibitor include bromelain, EDTA, heparin, sodium citrate, warfarin, and sodium fluoride.

Without intending to be limited by theory, blood clotting progresses in blood due to blood clotting factors. For example, among blood clotting factors, thrombin produces fibrin monomers from fibrinogen. Also, among blood clotting factors, activated factor XIII stabilizes the structure composed of fibrin by bridging between molecules of fibrin polymers, thereby producing stabilized fibrin.

Coagulation inhibitors can inhibit blood clotting by blocking the action of blood clotting factors.

Without intending to be limited by theory, for example, bromelain is believed to inhibit the conversion of fibrinogen to fibrin by causing a significant prolongation of the prothrombin time (PT) and activated partial thromboplastin time (APTT).

Also, without intending to be limited by theory, it is believed that, for example, EDTA inhibits the activation of thrombin, which is necessary for fibrin production, by chelating the calcium ions necessary for thrombin activity. Sodium citrate is also believed to work by a similar mechanism.

In addition, without intending to be limited by theory, it is believed that, for example, warfarin inhibits vitamin K, which is necessary for the functioning of blood clotting factors II, VII, IX, and X, which activate thrombin, thereby suppressing the activation of thrombin, which is necessary for the production of fibrin.

In addition, without intending to be limited by theory, it is believed that, for example, heparin suppresses the activation of thrombin, which is necessary for the production of fibrin, by enhancing the action of antithrombin, which inhibits thrombin.

Nattokinase and serrapeptase also have fibrin production inhibitory effects. Without intending to be limited by theory, it is believed that nattokinase present in blood exerts its fibrin inhibitory effect by reducing activated factor XIII, which crosslinks fibrin, and/or by inhibiting thrombin activity, which is necessary for fibrin production.

The water-soluble polymer (B) is not particularly limited as long as it is a polymer that can be dissolved in water, and may be a polymer that can be dissolved in heated water. The water-soluble polymer (B) preferably has a solubility of 5.0 g or more in 100 g of water at 25°C. The water solubility may be measured by dissolving the water-soluble polymer (B) in heated water and then adjusting the temperature to 25°C.

The water solubility is measured as follows.
(1) 100 g of deionized water and 20 g of water-soluble polymer (B) are mixed and stirred for 120 minutes using a stirrer to form a mixed solution. The 100 g of deionized water may be heated. The mixed solution may be heated when the mixed solution is stirred and mixed.
(2) After stirring and mixing, the resulting mixture is adjusted to 25°C.
(3) The aqueous phase in the mixed liquid adjusted to 25° C. is sampled and dried at 100° C. for 1 hour. The amount of water-soluble polymer (B) in the aqueous phase is determined from the loss on drying, and the solubility in 100 g of water at 25° C. is calculated.

Specific examples of the water-soluble polymer (B) include polyvinyl alcohol, polyethylene oxide, polyethylene glycol, water-soluble acrylic resin, polyvinylpyrrolidone, polyvinyl butyral, carboxymethylcellulose, sodium carboxymethylcellulose, and natural polysaccharides.

Examples of the polyvinyl alcohol include vinyl alcohol homopolymers obtained by saponifying polyvinyl acetate, which is a homopolymer of vinyl acetate, and polyvinyl alcohol copolymers obtained by saponifying a copolymer of vinyl acetate and another monomer that can be copolymerized with it.

The polyvinyl alcohol may be unmodified polyvinyl alcohol, which does not have any functional groups other than hydroxyl groups (OH groups) and acetate groups ( _OCOCH3 groups), or modified polyvinyl alcohol, which has functional groups other than hydroxyl groups and acetate groups. Examples of the functional groups that may be introduced into the modified polyvinyl alcohol include carboxy groups, carbonyl groups, sulfonic acid groups, phosphoric acid groups, silanol groups, cationic groups, and alkyl groups. The modified polyvinyl alcohol is preferably anion-modified polyvinyl alcohol, and more preferably carboxy-modified polyvinyl alcohol.

Examples of methods for producing the modified polyvinyl alcohol include a method of saponifying a copolymer of vinyl acetate and a monomer having a functional group other than a hydroxyl group and an acetate group that is copolymerizable with vinyl acetate; a method of reacting the hydroxyl group and/or acetate group in the vinyl alcohol homopolymer or polyvinyl alcohol copolymer with a compound that is reactive with the hydroxyl group and/or acetate group and has a functional group other than a hydroxyl group and an acetate group; and the like.

The method for producing the polyethylene oxide is not particularly limited, and for example, one obtained by ring-opening polymerization of ethylene oxide can be used. The polyethylene oxide may have an oxypropylene group ( _-CH2 -CH( _CH3 )-O-) in the molecule. Therefore, the polyethylene oxide may be a copolymer of ethylene oxide and propylene oxide.

The method for producing the polyethylene glycol is not particularly limited, and for example, one obtained by subjecting ethylene oxide to condensation ring-opening polymerization with ethylene glycol, one obtained by ring-opening polymerization of ethylene oxide in the presence of water, etc. may be used. The polyethylene glycol may also have an oxypropylene group in the molecule.

The water-soluble acrylic resin may be, for example, a water-soluble acrylic resin containing a structural unit derived from a hydrophilic (meth)acrylic monomer.
Examples of the hydrophilic (meth)acrylic monomer include carboxyl group-containing (meth)acrylic monomers such as (meth)acrylic acid and crotonic acid; hydroxyl group-containing (meth)acrylic monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and ring-opening adducts of these hydroxy (meth)acrylates with caprolactone, ethylene oxide, or the like; (meth)acrylic monomers having a polyoxyalkylene chain and no hydroxyl group; acrylamide monomers such as acrylamide and N-methoxymethylacrylamide; and amino group-containing (meth)acrylic monomers such as N,N-dimethylaminoethyl (meth)acrylate. These may be used alone or in combination of two or more.

The water-soluble acrylic resin may contain structural units derived from other (meth)acrylic monomers, styrene-based monomers, or vinyl-based monomers in addition to the structural units derived from the hydrophilic (meth)acrylic monomers.
The water-soluble acrylic resin can be obtained by polymerizing a hydrophilic (meth)acrylic monomer, and may be copolymerized with the other (meth)acrylic monomers, styrene-based monomers, or vinyl-based monomers, as necessary.
Furthermore, as the water-soluble acrylic resin, a copolymer of a hydrophilic polymerizable unsaturated monomer and a (meth)acrylic monomer may be used.
The hydrophilic polymerizable unsaturated monomer may, for example, be N-vinyl-2-pyrrolidone.

The water-soluble acrylic resin may be one obtained by making the resin water-soluble with an acid, an alkali, or the like. For example, when the hydrophilic (meth)acrylic monomer is a carboxyl group-containing (meth)acrylic monomer, the resin may be made water-soluble by neutralizing the monomer with an amine or ammonia, and when the monomer is an amino-containing (meth)acrylic monomer, the resin may be made water-soluble by neutralizing the monomer with an organic acid, or the like.

Examples of the natural polysaccharides include xanthan gum, guar gum, tamarind seed gum, locust bean gum, carrageenan, quince seed, alginic acid, pullulan, pectin, etc.

From the viewpoint of versatility, it is preferable that the water-soluble polymer (B) contains at least one of polyvinyl alcohol, polyethylene oxide, polyethylene glycol, and water-soluble acrylic resin.

When the water immersion solubility rate of the water-soluble polymer (B) is reduced in order to form a coating that is not easily affected by low-viscosity liquids, the water-soluble polymer (B) is preferably polyvinyl alcohol with a saponification degree of 50 to 100, preferably 70 to 99, and an average polymerization degree of 100 to 4,000, preferably 200 to 3,000.

At least a portion of the nattokinase, preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and even more preferably 80% by mass or more, is not bound to the water-soluble polymer (B). Also, 100% by mass of the nattokinase does not have to be bound to the water-soluble polymer (B). This allows the nattokinase to efficiently decompose fibrin in the blood clot and efficiently reduce the viscosity of the blood clot while suppressing the effect of nattokinase on the skin of the user of the absorbent article.

In this specification, "nattokinase is not bound to the water-soluble polymer (B)" means that nattokinase is not chemically bound to the water-soluble polymer (B) by a covalent bond or an ionic bond.
In addition, the fact that nattokinase is not bound to the water-soluble polymer (B) does not include the fact that nattokinase is hydrogen bonded to the water-soluble polymer (B).

The functional composition contains the functional substance (A) and the water-soluble polymer (B) in a mass ratio of preferably 5 and 95 to 95 and 5, more preferably 10 and 90 to 80 and 20, even more preferably 13 and 87 to 75 and 25, and even more preferably 15 and 85 to 70 and 30, based on 100 parts by mass of the total solid content of the functional substance (A) and the water-soluble polymer (B). This makes the functional composition, and thus nattokinase, less susceptible to the effects of low-viscosity liquids, has excellent action on blood clots, and is less likely to act on the skin.

In the above functional composition, the difference in water immersion solubility between the functional substance (A) (mass%) and the water immersion solubility of the water-soluble polymer (B) (mass%), that is, (a-b), is preferably 0<(a-b), more preferably 20<(a-b), and even more preferably 60<(a-b). This makes the above functional composition less susceptible to the effects of low-viscosity liquids.

Moreover, the difference in the water immersion dissolution rates: (a-b) is preferably (a-b)≦99, more preferably (a-b)≦98, even more preferably (a-b)<95, and even more preferably (a-b)<90. Thereby, when the functional composition comes into contact with a blood coagulate, it becomes easier to ensure the dissolution rate of the functional substance (A) in the blood coagulate, and the functional composition has an excellent effect on the blood coagulate.
When the upper and lower limits of the difference in water immersion dissolution rate are within the above-mentioned ranges, in the absorbent article, the functional substance (A), in particular, nattokinase, is less susceptible to the influence of low-viscosity liquids and is more likely to form a coating that has excellent action against blood coagulation.

The water-soluble polymer (B) preferably has a water immersion solubility of 5% by mass or more, more preferably 8% by mass or more, and even more preferably 10% by mass or more. The water-soluble polymer (B) also preferably has a water immersion solubility of 70% by mass or less, more preferably 60% by mass or less, even more preferably 40% by mass or less, and even more preferably 20% by mass or less. This makes the functional composition, particularly nattokinase, less susceptible to the effects of low-viscosity liquids and more likely to have excellent action on blood coagulation.

In this specification, the water immersion dissolution rate (mass%) is measured as follows.
(1) The target substance (functional substance (A), water-soluble polymer (B), etc.) is coated, diluted with deionized water as necessary, onto a glass plate (100 mm x 150 mm) whose mass: _m0 (g) has been measured, and the glass plate coated with the target substance is dried at 100°C for 1 hour to form a sample coated with the target substance to a thickness of 20 μm on the glass plate, and the mass: _m1 (g) of the sample is measured.
(2) The sample is immersed in deionized water (20°C, 5 L) and left to stand for 3 minutes. The sample is then removed and dried at 100°C for 1 hour, and the mass ( _m2 ) of the sample after immersion in water is measured.

(3) The water immersion dissolution rate (mass%) was calculated using the following formula:
Water immersion dissolution rate (mass%)=100×(m ₁ −m ₂ )/(m ₁ −m ₀ )
It is calculated as follows.
(4) The water immersion dissolution rate is measured five times for different samples, and the average value is used as the water immersion dissolution rate of the object.

A 10% by mass aqueous solution of the water-soluble polymer (B) preferably has a viscosity of 9,000 mPa·s or less, more preferably 5,000 mPa·s or less, even more preferably 3,000 mPa·s or less, even more preferably 2,000 mPa·s or less, and even more preferably 1,000 mPa·s or less. A 10% by mass aqueous solution of the water-soluble polymer (B) preferably has a viscosity of 100 mPa·s or more. As a result, even if the functional composition comes into contact with a low-viscosity liquid, the functional composition is less likely to flow out, and when the functional composition comes into contact with a blood clot, the functional substance (A) is more likely to diffuse into the blood clot. The above viscosity refers to the viscosity measured under the following conditions: temperature: 20°C, viscometer: B-type viscometer, rotor rotation speed: 60 rpm. In this specification, the viscosity under these conditions may be expressed as "viscosity (B-type, 20°C, 60 rpm)".

The functional composition may contain other components in addition to the functional substance (A) and the water-soluble polymer (B). Examples of the other components include polymers other than the water-soluble polymer (B), fillers, fragrances, preservatives, antioxidants, pH adjusters, deodorants, antibacterial agents, etc.

The functional composition can be arranged on the absorbent article in the form of particles, a film, an impregnated form, a stripe form, etc., without any particular limitations. When the functional composition is arranged on the material constituting the absorbent article, the functional composition can be arranged, for example, in the form of particles on the fibers constituting the nonwoven fabric or tissue, arranged so as to cover the fibers constituting the nonwoven fabric or tissue, arranged so as to be impregnated into the fibers constituting the nonwoven fabric or tissue, arranged in the form of particles on a perforated film, arranged in the form of a film on a perforated film, or arranged in the form of stripes on the nonwoven fabric, tissue, or perforated film.

The functional composition can be formed, for example, by applying a treatment liquid containing a functional substance (A) including nattokinase, a water-soluble polymer (B), and an aqueous solvent (C) to an absorbent article.

In the above treatment liquid, the aqueous solvent (C) may be water or a mixture of water and a water-soluble organic solvent in any ratio. Examples of the water-soluble organic solvent include alcohols such as methanol, ethanol, 1-propanol, 2-propanol (isopropanol), glycerin, ethylene glycol, and propylene glycol; ethers such as ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and tetrahydrofuran; and ketones such as acetone. These may be used alone or in combination of two or more. The water-soluble organic solvent preferably includes at least one selected from alcohols and ethers.

In addition, from the viewpoint of low residual property in the functional composition formed from the treatment liquid, the alcohols are preferably alcohols having 1 to 4 carbon atoms, more preferably alcohols having 1 to 4 carbon atoms and one hydroxyl group, and particularly preferably contain at least one selected from ethanol, 1-propanol, and 2-propanol.
Moreover, as the ethers, from the viewpoint of low residual property in the functional composition formed from the treatment liquid, ethers having 1 to 4 carbon atoms are more preferable, and it is particularly preferable that they include at least one selected from propylene glycol monomethyl ether and tetrahydrofuran.
The treatment liquid can be produced by mixing the functional material (A), the water-soluble polymer (B), the aqueous solvent (C), other components, etc., using a known mixing means.

The treatment liquid preferably has a solids concentration of 1 to 20% by mass.
The solids concentration of the treatment liquid can be measured by drying the treatment liquid at 130° C. for 3 hours.
The treatment liquid preferably has a pH of 5.0 to 10.0, and more preferably 5.2 to 9.8 at 20° C. in order to maintain the activity of the functional substance (A).
The pH can be measured, for example, using a twin pH meter F-52 manufactured by Horiba, Ltd.

The treatment liquid preferably has a viscosity of 3,000 mPa·s or less, and more preferably 1,000 mPa·s or less. The treatment liquid preferably has a viscosity of 10 mPa·s or more. This makes it easier to form a functional composition on an absorbent article from the treatment liquid. The viscosity is measured under the following conditions: temperature: 20°C, viscometer: B-type viscometer, rotor rotation speed: 60 rpm.

The treatment liquid can be applied to the material constituting the absorbent article by a conventionally known method, such as a spiral coater, curtain coater, spray coater, dip coater, etc., without any particular restriction. There is no particular restriction on the number of times the treatment liquid is applied to the material constituting the absorbent article, and for example, it may be applied once or multiple times, i.e., two or more times.

Materials constituting the absorbent article include a liquid-permeable top sheet (nonwoven fabric, perforated film, etc.), a liquid-impermeable back sheet (film, etc.), an absorbent placed between them (for example, an absorbent core (pulp fiber, etc.) and a core wrap (nonwoven fabric, tissue, etc.) covering the absorbent core), an optional upper diffusion sheet (nonwoven fabric, etc.) placed between the top sheet and absorbent, and an optional lower diffusion sheet (nonwoven fabric, etc.) placed between the absorbent and back sheet.

The treatment liquid can be applied to the top sheet, absorbent (e.g., absorbent core and core wrap covering said absorbent core), optional upper diffusion sheet, optional lower diffusion sheet, etc., and is preferably applied to the material on the skin contact side, e.g., the top sheet, in order to efficiently decompose menstrual blood.

The present disclosure will be explained in more detail below with reference to examples and comparative examples. However, the present disclosure is not limited to the examples. Note that "parts" and "%" are by mass unless otherwise specified.

[Preparation of Processing Solution]
[Production Example 1]
5.0 g of nattokinase (note 1) as the functional substance (A), 5.0 g of polyethylene glycol (note 2) as the water-soluble polymer (B), and 90.0 g of deionized water as the aqueous solvent (C) were mixed to obtain treatment solution No. 1. The pH of treatment solution No. 1 was 5.4.

[Production Examples 2 to 17, and Reference Production Example 1]
Treatment solutions No. 2 to No. 18 were obtained in the same manner as in Production Example 1, except that the formulation in Production Example 1 was changed as shown in Table 1. Table 1 shows the water immersion solubility (%) of the functional substance (A) and the water-soluble polymer (B) in Treatment Solutions No. 2 to No. 18, the water immersion solubility difference (%) which is the difference between the water immersion solubility of the functional substance (A) and the water-soluble polymer (B) (referred to as "solubility difference (%)"), and the viscosity of the water-soluble polymer (B) at a 10% concentration (B type, 20°C, 60 rpm) (referred to as "10% viscosity").

(Notes 1) to (Notes 10) in Table 1 are as follows:
(Note 1) Nattokinase powder, manufactured by Fujifilm Wako Pure Chemical Industries, dissolution rate when immersed in water: 99% or more (Note 2) Polyethylene glycol (PEG)
Average molecular weight: 20,000, water immersion solubility: 57%, viscosity at 10% concentration (B type, 20°C, 60 rpm): 3 mPa·s
(Note 3) Polyvinyl alcohol (PVA-1)
Average degree of polymerization: 300, degree of saponification: 98, solubility in water: 11%, viscosity at 10% concentration (B type, 20°C, 60 rpm): 17 mPa·s

(Note 4) Sodium polyacrylate (SPA)
Average molecular weight: 50,000, water immersion solubility: 95%, viscosity at 10% concentration (B type, 20°C, 60 rpm): 29 mPa·s
(Note 5) Polyvinyl alcohol (PVA-2)
Average degree of polymerization: 1,000, saponification degree: 98, water immersion solubility: 13%, viscosity at 10% concentration (B type, 20°C, 60 rpm): 291 mPa·s
(Note 6) Polyvinyl alcohol (PVA-3)
Average degree of polymerization: 1,700, degree of saponification: 88, solubility in water: 15%, viscosity at 10% concentration (B type, 20°C, 60 rpm): 700 mPa·s

(Note 7) Polyethylene oxide (PEO)
Average molecular weight: 300,000, water immersion solubility: 69%, viscosity at 10% concentration (B type, 20°C, 60 rpm): 790 mPa·s
(Note 8) Carboxy-modified polyvinyl alcohol (C-modified PVA)
Average degree of polymerization: 1,700, degree of saponification: 96, solubility in water: 37%, viscosity at 10% concentration (B type, 20°C, 60 rpm): 820 mPa·s
(Note 9) Polyvinyl alcohol (PVA-4)
Average degree of polymerization: 1,700, saponification degree: 96, water immersion solubility: 19%, viscosity at 10% concentration (B type, 20°C, 60 rpm): 920 mPa·s
(Note 10) Polyvinyl alcohol (PVA-5)
Average degree of polymerization: 3,300, degree of saponification: 88, solubility in water: 18%, viscosity at 10% concentration (B type, 20°C, 60 rpm): 8,100 mPa·s

[Examples 1 to 17, Reference Example 1 and Comparative Example 1]
["Rate of remaining high-viscosity menstrual blood when low-viscosity menstrual blood is not dripped" and "Rate of remaining high-viscosity menstrual blood after dripping low-viscosity menstrual blood"]
Regarding the functional compositions formed from treatment liquids No. 1 to No. 18, the residual rate of high-viscosity menstrual blood when low-viscosity menstrual blood was not dripped and the residual rate of high-viscosity menstrual blood after dripping of low-viscosity menstrual blood were measured according to the following method. The results are shown in Table 1.

[Creation of simulated high-viscosity menstrual blood]
(1) A solution of fibrinogen (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) in physiological saline (6.7 mg/mL) and a solution of thrombin (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) in physiological saline (333 units/mL) were each kept at 35°C.
(2) 2.1 mL of a solution of fibrinogen in saline and 0.3 mL of a solution of thrombin in saline were mixed in a petri dish, stirred for 2 seconds, and allowed to stand at 35° C. for 1 hour to prepare simulated high-viscosity menstrual blood.
[Creation of simulated low-viscosity menstrual blood]
(1) Defiberized horse blood (manufactured by Japan Bioserum) was used as a simulated low-viscosity menstrual blood.

[Test method]
(1) A treatment liquid (each of No. 1 to No. 18) is sprayed uniformly over an area of 5 cm x 3 cm (longitudinal x widthwise) centered on the longitudinal center and widthwise center (hereinafter referred to as the "sanitary napkin center") of the top sheet of a sanitary napkin (Bodyfit Regular, manufactured by Unicharm Corporation) so that the basis weight of the functional substance (A) adhered to the top sheet is as shown in Table 1.
(2) The sanitary napkins sprayed with treatment liquids No. 1 to No. 18 were left to stand at 30° C. for 120 minutes to dry, producing sanitary napkins No. 1 to No. 18. A sanitary napkin (Bodyfit Regular, manufactured by Unicharm Corporation) that was not sprayed with a treatment liquid was used as sanitary napkin No. 19 (blank).

(3) Preparation of samples for testing high-viscosity menstrual blood remaining rate without dripping low-viscosity menstrual blood 2.4 mL of simulated high-viscosity menstrual blood was dripped onto the center of the top sheet of each of sanitary napkins No. 1 to No. 19 to prepare sanitary napkins No. 1A to No. 19A for testing high-viscosity menstrual blood remaining rate without dripping low-viscosity menstrual blood.
(4) Preparation of samples for testing the rate of remaining high-viscosity menstrual blood after dropping of low-viscosity menstrual blood 6.0 mL of simulated low-viscosity menstrual blood was dropped onto the center of the top sheet of each of sanitary napkins No. 1 to No. 19, and then 2.4 mL of simulated high-viscosity menstrual blood was dropped to prepare sanitary napkins No. 1B to No. 19B for testing the rate of remaining high-viscosity menstrual blood after dropping of low-viscosity menstrual blood.

(5) Sanitary napkins No. 1A to No. 19A and sanitary napkins No. 1B to No. 19B are left to stand for 45 minutes under conditions of temperature: 35° C. and relative humidity: 60% RH.
(6) After leaving the sanitary napkin No. 19A (blank) for 45 minutes, the simulated highly viscous menstrual blood remaining on the top sheet is collected and its mass (m ₁₀ (g)) is measured.

(7) After leaving the sanitary napkin No. 1A for 45 minutes, the simulated highly viscous menstrual blood remaining on the top sheet is collected and its mass (m ₁₁ (g)) is measured.
(8) The high-viscosity menstrual blood remaining rate (%), which is the ratio of the remaining amount of simulated high-viscosity menstrual blood in sanitary napkin No. 1A to the remaining amount of simulated high-viscosity menstrual blood in sanitary napkin No. 19A (blank), was calculated using the following formula:
[Rate of high-viscosity menstrual blood remaining when low-viscosity menstrual blood is not dripped] (%)
= 100 × _m11 / _m10
It is calculated as follows.

(9) For sanitary napkins No. 2A to No. 18A, the "remaining rate (%) of high viscosity menstrual blood when low viscosity menstrual blood is not dripped" was calculated in the same manner as for sanitary napkin No. 1A. The results are shown in Table 1.
(10) After leaving the sanitary napkin No. 19B (blank) for 45 minutes, the simulated highly viscous menstrual blood remaining on the top sheet is collected and its mass (m ₂₀ (g)) is measured.
(11) After leaving the sanitary napkin No. 1B for 45 minutes, the simulated highly viscous menstrual blood remaining on the top sheet is collected and its mass (m ₂₁ (g)) is measured.

(12) The remaining rate (%) of high-viscosity menstrual blood after dropping of low-viscosity menstrual blood, which is the ratio of the remaining amount of simulated high-viscosity menstrual blood in sanitary napkin No. 1B to the remaining amount of simulated high-viscosity menstrual blood in sanitary napkin No. 19B (blank), was calculated using the following formula:
[Rate of high-viscosity menstrual blood remaining after low-viscosity menstrual blood dripping (%)]
= 100 × _m21 / _m20
It is calculated as follows.
(13) For sanitary napkins No. 2B to No. 18B, the percentage of high-viscosity menstrual blood remaining after low-viscosity menstrual blood was calculated in the same manner as for sanitary napkin No. 1B. The results are shown in Table 1.

In Table 1, the lower the percentage of high-viscosity menstrual blood remaining after low-viscosity menstrual blood is dripped, the more the high-viscosity menstrual blood is reduced in viscosity without being affected by the low-viscosity menstrual blood. Also, in Table 1, the smaller the difference between the percentage of high-viscosity menstrual blood remaining after low-viscosity menstrual blood is dripped and the percentage of high-viscosity menstrual blood remaining when low-viscosity menstrual blood is not dripped, the more the high-viscosity menstrual blood is reduced in viscosity without being affected by the low-viscosity menstrual blood.

When volunteer subjects tried wearing sanitary napkins No. 1 to No. 19, they responded that sanitary napkins No. 1 to No. 17 were less likely to leave menstrual blood on the top sheet than sanitary napkin No. 18, and that the degree to which menstrual blood remained was roughly equivalent to the "Rate of high-viscosity menstrual blood remaining after low-viscosity menstrual blood was applied (%)" in Table 1. They also responded that sanitary napkins No. 1 to No. 18 were less likely to cause skin irritation.

Claims

An absorbent article comprising a functional composition containing a functional substance (A) having a function of inhibiting a blood coagulation factor, including nattokinase, and a water-soluble polymer (B),
At least a portion of the nattokinase is not bound to the water-soluble polymer (B);
The absorbent article.
The absorbent article according to claim 1, wherein the functional substance (A) having the function of inhibiting factors that act on blood clotting contains more than 50% by mass of the nattokinase.
The absorbent article according to claim 1 or 2, wherein the functional composition contains a functional substance (A) having a function of inhibiting factors that act on blood clotting and a water-soluble polymer (B) in a mass ratio of 5:95 to 95:5 based on 100 parts by mass of the total solid content of the functional substance (A) having a function of inhibiting factors that act on blood clotting and the water-soluble polymer (B).
The absorbent article according to any one of claims 1 to 3, in which the difference in solubility in water of the functional substance (A) having the function of inhibiting factors that act on blood coagulation: a (mass%) and the water-soluble polymer (B) having the solubility in water of b (mass%) is 0<(a-b).
The absorbent article according to any one of claims 1 to 4, wherein the water-soluble polymer (B) has a water immersion solubility of 5 to 70% by mass.
The absorbent article according to any one of claims 1 to 5, wherein the water-soluble polymer (B) has a viscosity of 9,000 mPa·s or less under the following measurement conditions: 10% by weight aqueous solution, temperature: 20°C, viscometer: B-type viscometer, rotor rotation speed: 60 rpm.
The absorbent article according to any one of claims 1 to 6, wherein the water-soluble polymer (B) comprises at least one of polyvinyl alcohol, polyethylene oxide, polyethylene glycol, and a water-soluble acrylic resin.
The absorbent article according to any one of claims 1 to 7, wherein the absorbent article comprises a liquid-permeable top sheet containing a nonwoven fabric, and the functional composition is disposed in the form of particles on the surface of the fibers constituting the nonwoven fabric, disposed so as to cover the fibers constituting the nonwoven fabric, or impregnated into the fibers constituting the nonwoven fabric.
The absorbent article according to any one of claims 1 to 8, wherein the absorbent article comprises a liquid-permeable top sheet including a perforated film, and the functional composition is disposed in the form of particles on the surface of the perforated film, or in the form of a film on the surface of the perforated film.