JP2017039111A - Super absorbent polymer material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a super absorbent polymer material capable of improving liquid permeability in an absorber in use by reducing a liquid film formed between super absorbent polymer materials absorbing water while maintaining liquid swelling properties or liquid-holding properties of the super absorbent polymer material.SOLUTION: There is provided a super absorbent polymer material 1 to which a liquid film cleavage agent 3, in which the spreading coefficient relative to a liquid having a surface tension of 50 mN/m is 20 mN/m or more and the water solubility is 0 g or more and 0.025 g or less, is adhered.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a superabsorbent polymer material.

A superabsorbent polymer material (a surface-crosslinked polymer material called SAP) is used as a water-absorbing agent for excrement of an absorbent that forms a liquid holding part in absorbent articles such as diapers and sanitary napkins. . This superabsorbent polymer material can hold and confine the liquid inside while absorbing and swelling the liquid, for example, several tens of times its own weight. The absorbent body containing the superabsorbent polymer material has higher absorption performance than an absorbent body made only of fibers such as pulp. Therefore, the superabsorbent polymer material can improve the absorption performance of the absorbent body while reducing the amount of fibers, and can contribute to the thinning of the absorbent body and absorbent articles incorporating the absorbent body.
On the other hand, the superabsorbent polymer material gels when swollen by water absorption. In the absorbent body, the superabsorbent polymer material gelled first on the side close to the liquid receiving surface may form a gel layer, which may inhibit liquid permeation and diffusion. With respect to this, there have heretofore been attempts to improve the absorption performance of superabsorbent polymer materials using water-insoluble or poorly water-soluble compounds, surfactants, and the like (for example, Patent Documents 1 to 4).

International Publication No. 2012/133734 JP-A-8-289903 JP 2014-237133 A JP-A-8-92454

The above-described thinning of the absorbent body has come to require a higher level from the viewpoint of not only wearing comfort corresponding to various activities in daily life, but also a natural appearance that is not noticed.
However, as the thickness of the absorber is further reduced, the denseness of the superabsorbent polymer material inside the absorber increases more than ever. In other words, the gap between each superabsorbent polymer material or between the superabsorbent polymer material and the fiber is extremely narrowed, and the pressure received by the superabsorbent polymer material is increased. The meniscus force works in the extremely narrow void area, and the surface activity caused by plasma proteins contained in menstrual blood and the surface viscosity of blood are high. Therefore, there is a gap between the superabsorbent polymer material and the superabsorbent polymer material or fiber. A stable liquid film is formed, and the liquid tends to stay. Also, urine has surface activity due to phospholipids, and it is easy to form a liquid film as described above. The formation of this liquid film hinders the liquid permeability and diffusibility of the liquid in the absorbent body, does not fully exhibit the absorption performance of the high absorbent polymer material itself, and causes a decrease in the liquid absorbability of the absorbent body. End up. That is, the formation of the liquid film becomes an inhibiting factor for liquid absorption different from the above-described formation of the gel layer.
Thus, there is still no technology for effectively removing a liquid film that can be formed in a narrow region such as a space between superabsorbent polymer materials in an absorbent body that is further reduced in thickness. The above-mentioned problems cannot be solved by the water-insoluble or poorly water-soluble compounds and surfactants described in the above-mentioned patent documents.

  In view of the above problems, the present invention reduces the liquid film that can be formed between the superabsorbent polymer materials that have absorbed water while maintaining the liquid swellability and liquid retainability of the superabsorbent polymer material, and the absorbent body in use. The present invention relates to the provision of a superabsorbent polymer material capable of realizing improved liquid permeability.

  The present invention provides a superabsorbent polymer material to which a liquid film cleaving agent having an expansion coefficient of 20 mN / m or more and a water solubility of 0 g to 0.025 g is attached to a liquid having a surface tension of 50 mN / m. .

  The superabsorbent polymer material of the present invention reduces the liquid film formed between the superabsorbent polymer materials that have absorbed water while maintaining the liquid swellability and liquid retainability of the superabsorbent polymer material, so that it can pass through the absorbent body in use. Improvement in liquidity can be realized.

It is a schematic diagram which shows the liquid film formed in the clearance gap between high absorption polymer materials. (A1)-(A4) is explanatory drawing which shows typically the state which a liquid film cleaving agent cleaves a liquid film from a side surface, (B1)-(B4) is a liquid film cleaving agent cleaves a liquid film. It is explanatory drawing which shows typically the state to carry out from upper direction.

  The superabsorbent polymer material of the present invention is formed by adhering a liquid film cleaving agent. The liquid film cleaving agent refers to an agent that cleaves a liquid film formed by leaving a liquid, for example, highly viscous liquid such as menstrual blood or excretory liquid such as urine remaining in a narrow space. For example, inside the absorbent body for absorbent articles, only the superabsorbent polymer material of the present invention is accumulated and densely packed, or the superabsorbent polymer material of the present invention and fibers such as pulp are mixed and densely packed. In this state, it refers to an agent that cleaves the liquid film that remains in the voids between the superabsorbent polymer materials or between the superabsorbent polymer materials and the fibers when the excretory fluid is received. This cleavage is performed by the action of pushing away a part of the layer of the liquid film and making the film unstable.

By the action of the liquid film cleaving agent, the liquid can easily pass through without staying in a narrow region between the superabsorbent polymer materials that have absorbed the liquid. That is, the liquid film cleaving agent serves as a driving force for eliminating the liquid film-like liquid residue in the gaps between the superabsorbent polymer materials. In other words, the liquid film cleaving agent acts to supplement the performance of the superabsorbent polymer material itself under the pressurized flow rate and increase the pressurized fluid flow rate of the absorbent body incorporating the superabsorbent polymer material. In particular, a thin absorbent body (polymer sheet) in which only the superabsorbent polymer material is integrated, an absorbent body having a small amount of pulp fibers and high pressure on the superabsorbent polymer material, and the like are highly effective. In general, it is unavoidable to select those absorbent bodies that have a large amount of absorption under pressure at the expense of the liquid passing speed under pressure of the superabsorbent polymer. In addition, the gap between the superabsorbent polymers is narrowed under high pressure, and a liquid film is easily formed. Even in this case, the action of the liquid film cleaving agent can achieve both the absorption amount under pressure and the liquid passing rate under pressure as the absorber.
This makes it difficult for excretory liquid to remain as a liquid film around the high-absorbent polymer material in the absorbent body constituting the absorbent article, and has excellent liquid permeability, and also supports large amounts of excretion and repeated excretion. It becomes. In addition, the action of such a liquid film cleaving agent further increases the amount of the superabsorbent polymer material and enables the compaction. Moreover, even if the liquid film cleaving agent adheres to the surface, the superabsorbent polymer material of the present invention has higher ionicity than the excretory liquid, and absorbs and holds the liquid by the force of osmotic pressure. To do.
The absorbent article here is used for absorbing and holding liquid discharged from the body, and examples thereof include disposable diapers, sanitary napkins, and incontinence pads. Moreover, the absorber in an absorbent article is a member which makes the liquid holding | maintenance part of an absorbent article. In addition, the above-mentioned “pressure” of the amount of absorption under pressure and the liquid passing rate under pressure is an average that is normally applied by body pressure or the like when an absorbent article incorporating an absorbent containing a highly absorbent polymer material is attached. A pressure is assumed, and in the present application, a pressure of 2 kPa is meant.

  The adhesion of the liquid film cleaving agent in the superabsorbent polymer material of the present invention refers to the adhesion of the superabsorbent polymer material to the surface. However, as long as the liquid film cleaving agent remains on the surface of the superabsorbent polymer material, it can be contained in the superabsorbent polymer material as long as it does not impair the liquid absorption / retention performance of the superabsorbent polymer material. May be present in the superabsorbent polymer material.

  As a method for attaching the liquid film cleaving agent to the surface of the superabsorbent polymer material, various commonly used methods can be employed without particular limitation. For example, a superabsorbent polymer material that is a raw material for the superabsorbent polymer material of the present invention (that is, a normal superabsorbent polymer material before a liquid film cleaving agent is attached. A method of adding a liquid film cleaving agent to the surface of the raw material superabsorbent polymer material after forming is mentioned. Or the method of adding a liquid film cleaving agent in the formation process of a raw material superabsorbent polymer material may be used. As a method of adding the liquid film cleaving agent after forming the raw material high absorption polymer material, for example, a liquid film cleaving agent and a solvent are mixed and heated to prepare a solution, and the raw material high absorption polymer material is added to the solution. Examples of the method include dipping or coating the solution on the raw material superabsorbent polymer material by spraying, slot coater, or roll transfer. In the case of immersion, you may make it adhere by stirring with rotary mixers, such as a cylindrical mixer, a screw type mixer, a screw type extruder. The solvent is not particularly limited, and examples thereof include methanol, ethanol, isopropanol and the like. There is also a method of adhering a liquid film cleaving agent and a superabsorbent polymer material by mixing them with the above-mentioned rotary mixer.

  Hereinafter, preferred embodiments of the superabsorbent polymer material to which the liquid film cleaving agent is attached according to the present invention will be described.

  The superabsorbent polymer material of this embodiment has a liquid film cleaving agent with an expansion coefficient of 20 mN / m or more and a water solubility of 0 g or more and 0.025 g or less for a liquid having a surface tension of 50 mN / m.

The “expansion coefficient for a liquid having a surface tension of 50 mN / m” possessed by the liquid film cleaving agent refers to an expansion coefficient that assumes the above-mentioned excretion fluid such as menstrual blood and urine. The “expansion coefficient” is a value obtained based on the following formula (1) from a measurement value obtained by a measurement method described later in an environmental region at a temperature of 25 ° C. and a relative humidity (RH) of 65%. In addition, the liquid film in Formula (1) means the liquid phase of "the liquid whose surface tension is 50 mN / m". In addition, the surface tension of the formula (1) means the interfacial tension at the interface between the liquid film and the liquid film cleaving agent and the interfacial tension between the liquid phase and the liquid film cleaving agent. To do. This distinction applies to other descriptions in the present specification.
S = γw−γo−γwo (1)
γw: surface tension of liquid film
γo: surface tension of liquid film cleaving agent
γwo: Interfacial tension of liquid film cleaving agent with liquid film

  As can be seen from equation (1), the expansion coefficient (S) of the liquid film cleaving agent increases as the surface tension (γo) of the liquid film cleaving agent decreases, and the interfacial tension of the liquid film cleaving agent with the liquid film ( It increases as γwo) decreases. When the expansion coefficient is 20 mN / m or more, the liquid film cleaving agent has high mobility on the surface of the liquid film, that is, high diffusibility, which occurs in a narrow region such as between highly absorbent polymer materials. From this viewpoint, the expansion coefficient of the liquid film cleaving agent is more preferably 25 mN / m or more, and further preferably 30 mN / m or more. On the other hand, the upper limit is not particularly limited, but when a liquid having a surface tension of 50 mN / m is used from the formula (1), a liquid having an upper limit of 50 mN / m and a surface tension of 60 mN / m was used. In this case, when a liquid having an upper limit of 60 mN / m and a surface tension of 70 mN / m is used, the surface tension of the liquid forming the liquid film becomes an upper limit, such as 70 mN / m. Therefore, in the present invention, from the viewpoint of using a liquid having a surface tension of 50 mN / m, it is 50 mN / m or less.

  The “water solubility” of the liquid film cleaving agent is the dissolvable mass of the liquid film cleaving agent with respect to 100 g of ion-exchanged water. Based on the measurement method described later, the environment has a temperature of 25 ° C. and a relative humidity (RH) of 65%. A value measured in the region. When the water solubility is 0 g or more and 0.025 g or less, the liquid film cleaving agent is difficult to dissolve and forms an interface with the liquid film, thereby making the diffusibility more effective. From the same viewpoint, the water solubility of the liquid film cleaving agent is preferably 0.020 g or less, more preferably 0.015 g or less, and still more preferably 0.010 g or less. Moreover, the smaller the water solubility, the better. It is 0 g or more, and from the viewpoint of diffusibility into the liquid film, it is practical to be 0.005 g or more. In addition, it is thought that said water solubility is applicable also to the menstrual blood, urine, etc. which have a water | moisture content as a main component.

The surface tension (γw) of the liquid film (liquid having a surface tension of 50 mN / m), the surface tension of the liquid film cleaving agent (γo), the interfacial tension of the liquid film cleaving agent (γwo), and the liquid The water solubility of the membrane cleaving agent is measured by the following method.
In addition, when the superabsorbent polymer material to be measured is a member (for example, an absorbent body) incorporated in an absorbent article such as a sanitary product or a disposable diaper, the measurement is taken out as follows. That is, in the absorbent article, after the adhesive used for joining the member to be measured and other members is weakened by a cooling means such as cold spray, the member to be measured is carefully peeled off and taken out.
When measuring the liquid film cleaving agent adhering to the surface of the superabsorbent polymer material, the superabsorbent polymer material adhering to the liquid film cleaving agent was first washed with a cleaning liquid such as hexane, methanol, ethanol, etc. The solvent (cleaning solvent containing a liquid film cleaving agent) is dried and taken out. If the amount of the extracted material is too small to measure the surface tension or interfacial tension, select an appropriate column and solvent according to the composition of the extracted material, and then fractionate each component by high performance liquid chromatography. Furthermore, the structure of each fraction is identified by performing MS measurement, NMR measurement, elemental analysis and the like for each fraction. When the liquid film cleaving agent contains a polymer compound, it becomes easier to identify the constituents by using a technique such as gel permeation chromatography (GPC) together. If the substance is a commercial product, it is procured, and if it is not a commercial product, a sufficient amount is obtained by synthesis, and the surface tension and interfacial tension are measured. In particular, regarding the measurement of surface tension and interfacial tension, when the liquid film cleaving agent obtained as described above is a solid, it is heated to a phase transition temperature and measured as a liquid.

(Measurement method of surface tension (γw) of liquid film)
Measurement can be performed using a platinum plate by the plate method (Wilhelmy method) in an environmental region at a temperature of 25 ° C. and a relative humidity (RH) of 65%. As a measuring device at that time, an automatic surface tension meter “CBVP-Z” (trade name, manufactured by Kyowa Interface Science Co., Ltd.) can be used. A platinum plate having a purity of 99.9%, a size of 25 mm in width, and 10 mm in length is used.
In addition, the above-mentioned “liquid having a surface tension of 50 mN / m” is a solution prepared by adding a surfactant to ion-exchanged water so as to obtain a target surface tension using the above-described measurement method.

(Measurement method of surface tension (γo) of liquid film cleaving agent)
Similar to the measurement of the surface tension (γw) of the liquid film, it can be measured using the same apparatus by the plate method in an environmental region at a temperature of 25 ° C. and a relative humidity (RH) of 65%. In this measurement, as described above, when the obtained liquid film cleaving agent is a solid, the liquid film cleaving agent is heated to a phase transition temperature and measured as a liquid.

(Measurement method of interfacial tension (γwo) of liquid film cleaving agent with liquid film)
It can be measured by the pendant drop method in an environmental region where the temperature is 25 ° C. and the relative humidity (RH) is 65%. As the measuring device at that time, an automatic interface viscoelasticity measuring device (manufactured by TECRIS-ITCONCEPT, trade name: THE TRACKER) can be used. In the pendant drop method, the adsorption of the surfactant contained in the liquid having a surface tension of 50 mN / m starts at the same time as the drop is formed, and the interfacial tension decreases with time. Therefore, the interfacial tension when the drop is formed (at 0 second) is read. In this measurement, as described above, when the obtained liquid film cleaving agent is a solid, the liquid film cleaving agent is heated to a phase transition temperature and measured as a liquid.

(Measurement method of water solubility of liquid film cleaving agent)
Dissolving when the obtained liquid film cleaving agent is gradually dissolved in 100 g of ion-exchanged water in an environmental region where the temperature is 25 ° C. and the relative humidity (RH) is 65%, and when it becomes insoluble (precipitation is observed). The amount is the water solubility. When the liquid film cleaving agent is a surfactant, “dissolution” means both monodisperse dissolution and micelle dispersion dissolution, and the amount of dissolution at the time when cloudy precipitation is observed is the water solubility.

  The liquid film cleaving agent used in the present embodiment has the above expansion coefficient and water solubility, so that it spreads without dissolving on the surface of the liquid film and pushes the liquid film layer from the vicinity of the center of the liquid film. be able to. As a result, the liquid film is destabilized and cleaved.

Here, the said effect | action of the liquid film cleaving agent in the superabsorbent polymer material of this embodiment is demonstrated concretely with reference to FIG.
As shown in FIG. 1, in a narrow region such as between high-absorbing polymer materials, particularly in a narrow region between high-absorbing polymer materials that have absorbed and swollen liquid, highly viscous liquid such as menstrual blood or urine fluid is liquid film 2 is easy to stretch. On the other hand, the liquid film cleaving agent destabilizes the liquid film and breaks the film as follows to promote drainage. First, as shown in FIGS. 2A1 and 2B1, the liquid film cleaving agent 3 moves on the surface of the liquid film 2 while maintaining the interface with the liquid film 2. Next, as shown in FIGS. 2 (A2) and (B2), the liquid film cleaving agent 3 pushes away a part of the liquid film 2 and penetrates in the thickness direction, as shown in FIGS. 2 (A3) and (B3). Thus, the liquid film 2 is gradually changed to a non-uniform and thin film. As a result, as shown in FIGS. 2 (A4) and (B4), the liquid film 2 is opened and cleaved so as to be repelled. The cleaved menstrual fluid or the like becomes liquid droplets and easily passes between the swollen superabsorbent polymer material which absorbs the fluid and the remaining liquid is reduced.
Note that the shape of the superabsorbent polymer material is schematically shown, and the shape of the superabsorbent polymer material does not necessarily have to be the same as the illustrated shape in the practice of the present invention.

  Thus, the liquid film cleaving agent does not lower the surface tension of the liquid film, but promotes drainage of the liquid by cleaving while pushing away the liquid film itself. Thereby, the liquid residue between superabsorbent polymer materials etc. can be reduced. In addition, when such a superabsorbent polymer material is incorporated into the absorbent body of the absorbent article, the liquid stagnation between the superabsorbent polymer material and the like is suppressed, and a liquid permeation path to the absorber is secured. Thereby, in the absorbent article incorporating the space between the superabsorbent polymer materials, the liquid permeability is increased and the liquid absorption rate is increased. In particular, it is possible to increase the absorption rate of a liquid that tends to stay between highly absorbent polymer materials such as highly viscous menstrual blood. And it is set as the safe and reliable absorbent article which the redness and other stain | pollution | contamination in a surface sheet are not conspicuous, and can feel an absorptivity.

  In the present embodiment, the liquid film cleaving agent preferably further has an interface tension of 20 mN / m or less with respect to a liquid having a surface tension of 50 mN / m. That is, it means that “an interfacial tension (γwo) of the liquid film cleaving agent with respect to the liquid film”, which is one variable for determining the value of the expansion coefficient (S) in the above-described formula (1), is 20 mN / m or less. By suppressing the “interfacial tension of the liquid film cleaving agent with the liquid film (γwo)”, the diffusion property of the liquid film cleaving agent is improved, and the liquid film cleaving agent is moved from the surface of the highly absorbent polymer material to the vicinity of the liquid film center. It becomes easy to shift, and the above-mentioned action becomes clearer. From this viewpoint, the “interfacial tension with respect to a liquid having a surface tension of 50 mN / m” of the liquid film cleaving agent is preferably 10 mN / m or less, more preferably less than 5 mN / m, and particularly preferably 1 mN / m or less. On the other hand, the lower limit is not particularly limited, and may be larger than 0 mN / m from the viewpoint of insolubility in the liquid film. Note that when the interfacial tension is 0 mN / m, that is, when dissolution occurs, the interface between the liquid film and the liquid film cleaving agent cannot be formed, and therefore Equation (1) does not hold and the diffusion coefficient is zero.

  In the present embodiment, the surface tension of the liquid film cleaving agent is preferably 30 mN / m or less, more preferably 25 mN / m or less, and still more preferably 22 mN / m or less. Moreover, the said surface tension is so good that it is small, and the minimum is not specifically limited. From the viewpoint of durability of the liquid film cleaving agent, 1 mN / m or more is practical.

  In the superabsorbent polymer material of the present embodiment, the adhesion ratio of the liquid film cleaving agent is preferably 0.1 mass relative to the mass of the raw superabsorbent polymer material from the viewpoint of cleaving the liquid film between the superabsorbent polymer materials. % Or more, and more preferably 0.5% by mass or more. Further, the adhesion ratio of the liquid film cleaving agent is preferably 5.0% by mass or less with respect to the mass of the raw material superabsorbent polymer material from the viewpoint of not greatly changing the hydrophilicity / hydrophobicity of the superabsorbent polymer material surface, More preferably, it is 3.0 mass% or less. For example, the adhesion ratio of the liquid film cleaving agent is preferably 0.1% by mass or more and 5.0% by mass or less, more preferably 0.5% by mass or more, with respect to the mass of the raw material superabsorbent polymer material. It is 3.0 mass% or less.

  Next, specific examples of the liquid film cleaving agent in the present embodiment will be described.

The liquid film cleaving agent in this embodiment is preferably a compound having a mass average molecular weight of 500 or more. This mass average molecular weight greatly affects the viscosity of the liquid film cleaving agent. If the viscosity is too low, the transition of the liquid film cleaving agent from the superabsorbent polymer material to the liquid film is promoted, so that the liquid film cleaving agent flows down when the liquid passes between the superabsorbent polymer materials, and the liquid film The sustainability of the cleavage effect is reduced. From the viewpoint of achieving a viscosity that sufficiently maintains the liquid film cleavage effect, the mass average molecular weight of the liquid film cleavage agent is more preferably 1000 or more, and even more preferably 1500 or more. On the other hand, if the viscosity is too high, the diffusibility may be lowered. From the viewpoint of setting the viscosity to maintain this diffusibility, the mass average molecular weight of the liquid film cleaving agent is preferably 50000 or less, more preferably 20000 or less. 10,000 or less is more preferable. The mass average molecular weight is measured using a gel permeation chromatograph (GPC) “CCPD” (trade name, manufactured by Tosoh Corporation). The measurement conditions are as follows. The calculated molecular weight is calculated with polystyrene.
Separation column: GMHHR-H + GMHHR-H (cation)
Eluent: L Farmin DM20 / CHCl3
Solvent flow rate: 1.0 ml / min
Separation column temperature: 40 ° C

The liquid film cleaving agent in the present embodiment is preferably a compound having at least one structure selected from the group consisting of structures X, XY, and YXY having the following meanings.
In structure X, CA <C: carbon atom>, CA ₂ , CAB, CACR ¹ , CR ¹ , CR ¹ R ² , CR ¹ ₂ , and any basic skeleton of SiOR ¹ ₂ , SiOR ¹ R ² is continuous. Or a siloxane chain or a mixed chain formed by combining them, and at the end of the structure X, CA ₃ , CA ₂ B, CAB _2, CA ₂ CR ¹ , CR ¹ ₂ A, CR ¹ ₃ Further, it represents one having at least one structure selected from the group consisting of SiOR ¹ ₃ , SiOR ¹ ₂ R ² , SiR ¹ ₃ , and SiR ¹ ₂ R ² .
Each of R ¹ and R ² independently represents various substituents such as a hydrogen atom, a methyl group, an ethyl group, a propyl group, a methoxy group, an ethoxy group, a phenyl group, and a fluorine atom. A and B each independently represent a substituent containing an oxygen atom or a nitrogen atom such as a hydroxyl group, a carboxylic acid group, an amino group, an amide group, an imino group, or a phenol group. When there are a plurality of R ¹ , R ² , A, and B in the structure X, they may be the same as or different from each other. In addition, the bond between continuous C (carbon atoms) and Si is basically a single bond, but may include a double bond or a triple bond. A linking group such as a group, an ester group, a carbonyl group, or a carbonate group may be included. The number of one C and Si bonded to the other C or Si is 1 to 4, and a long silicone chain may be branched or may have a radial structure. Also good.
The structure Y represents a hydrophilic group having hydrophilicity including an atom selected from H, C, O, N, P, and S. For example, hydroxyl group, carboxylic acid group, amino group, amide group, imino group, phenol group, polyoxyethylene (POE) group, polyoxypropylene (POP) group, sulfonic acid group, sulfuric acid group, phosphoric acid group, sulfobetaine group , A carbobetaine group, a phosphobetaine group, a hydrophilic group such as a quaternary ammonium group, or a hydrophilic group composed of a combination thereof.
By having this structure, the aforementioned diffusion coefficient, water solubility, and interfacial tension are satisfied, and a liquid film cleavage effect is exhibited.

  The liquid film cleaving agent is preferably composed of a compound having a chemical structure in which the main chain contains a silicon atom, and composed of Si molecules arbitrarily combined with skeletons represented by the following formulas (1) to (11). It preferably consists of a compound having a chemical structure. Furthermore, it is preferable from the viewpoint of the liquid film cleaving action that this compound has a mass average molecular weight in the above-mentioned range.

In the formulas (1) to (11), M ¹ , L ¹ , R ²¹ , R ²² , R ²³ , and R ²⁴ represent the following monovalent or polyvalent groups.
M ¹ is a group having a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, or a polyoxyalkylene group obtained by combining them, an erythritol group, a xylitol group, a sorbitol group, a glycerin group or an ethylene glycol group. Hydrophilic groups having a plurality of hydroxyl groups, hydroxyl groups, carboxylic acid groups, mercapto groups, methoxy groups, amino groups, amide groups, imino groups, phenol groups, sulfonic acid groups, quaternary ammonium groups, sulfobetaine groups, hydroxysulfobetaine groups, It represents a phosphobetaine group, an imidazolium betaine group, a carbobetaine group, an epoxy group, a carbinol group, a methacryl group, or a functional group that is a combination thereof.
L ¹ represents a bonding group of an ether group, an amino group, an amide group, an ester group, a carbonyl group, or a carbonate group.
R ²¹ , R ²² , R ²³ , and R ²⁴ are each independently a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethyl-hexyl group, a nonyl group, It represents a decyl group, a methoxy group, an ethoxy group, a phenyl group, a fluoroalkyl group, an aralkyl group, a hydrocarbon group obtained by combining them, or a fluorine atom.

  Furthermore, as a specific example of the above compound, organically modified silicone which is a silicone-based surfactant can be mentioned. Among these, reactivity includes amino modification, epoxy modification, carboxy modification, carbinol modification, methacryl modification, mercapto modification, phenol modification, and non-reactivity includes polyether modification, methylstyryl modification, Examples include long chain alkyl modification, higher fatty acid ester modification, higher alkoxy modification, higher fatty acid modification, and fluorine modification. Among these, polyoxyalkylene-modified silicone is particularly preferable. Since the polyoxyalkylene-modified silicone has a polysiloxane chain, the polyoxyalkylene-modified silicone hardly penetrates into the superabsorbent polymer material and easily remains on the surface. In addition, the addition of a hydrophilic polyoxyalkylene chain is preferable because the affinity with water is increased and the interfacial tension is low, so that the movement on the surface of the liquid film is likely to occur. Therefore, it is preferable that the movement on the surface of the liquid film described above easily occurs. From this viewpoint, polyoxyalkylene-modified silicone is preferable to other modified silicones such as amino-modified silicone and epoxy-modified silicone. In addition, even if the polyoxyalkylene-modified silicone is subjected to hot melt processing such as embossing, it tends to remain on the surface of the superabsorbent polymer material at that portion, and the liquid film cleavage action is difficult to reduce. In particular, the liquid film cleaving action is sufficiently exhibited at the embossed portion where the liquid tends to accumulate, which is preferable.

  Examples of the polyoxyalkylene-modified silicone include those represented by the following general formulas [I] to [IV]. Furthermore, the polyoxyalkylene-modified silicone preferably has a mass average molecular weight within the above-mentioned range from the viewpoint of the liquid film cleavage action.

In the formula, R ³¹ represents a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethyl-hexyl group, a nonyl group, a decyl group, and the like, and R ³² represents a methylene group. , Ethylene group, propylene group, butylene group, N- (aminoethyl) methylimino group, N- (aminopropyl) propylimino group, and the like. The plurality of R ³¹ and the plurality of R ³² may be the same as or different from each other. M ¹¹ represents a group having a polyoxyalkylene group. Examples of the polyoxyalkylene group include a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, and those obtained by copolymerizing these constituent monomers. m and n each independently represents an integer of 1 or more. In addition, the code | symbol of these repeating units is determined separately in each general formula (A)-(IV), and does not necessarily show the same integer, and may differ.

  Further, the polyoxyalkylene-modified silicone may have one or both modified groups of polyoxyethylene-modified and polyoxypropylene-modified. Further, in order to have a low interfacial tension that is insoluble in water, it is desirable to have a methyl group in the alkyl part of the silicone skeleton. Although it does not restrict | limit especially as what has this modified group and silicone frame | skeleton, For example, there exists a thing as described in Paragraph [0006] and [0012] of Unexamined-Japanese-Patent No. 2002-161474. More specifically, polyoxyethylene (POE) polyoxypropylene (POP) modified silicone, polyoxyethylene (POE) modified silicone, polyoxypropylene (POP) modified silicone and the like can be mentioned. Examples of the POE-modified silicone include POE (3) -modified dimethyl silicone added with 3 moles of POE. Examples of the POP-modified silicone include POP (10) -modified dimethyl silicone, POP (12) -modified dimethyl silicone, POP (24) -modified dimethyl silicone to which POP is added at 10 mol, 12 mol, or 24 mol.

In particular, those having the above-mentioned expansion coefficient and water solubility are preferably those in which the number of added moles of the polyoxyalkylene group is 1 or more. If it is less than 1, the interfacial tension becomes high and the effect becomes weak for the liquid film cleavage action. In this respect, the number of added moles is more preferably 3 or more, and further preferably 5 or more. On the other hand, if the added mole number is too large, it becomes hydrophilic and the water solubility becomes high. In this respect, the number of added moles is preferably 30 or less, more preferably 20 or less, and still more preferably 10 or less.
If the modification rate of the modified silicone is too low, the interfacial tension increases, leading to a decrease in liquid film cleavage performance, preferably 1% or more, more preferably 5 or more, and even more preferably 10 or more. Moreover, since it will melt | dissolve in water and liquid film cleavage performance will be impaired when too high, 95% or less is preferable, 70 or less is more preferable, and 40 or less is still more preferable.

In addition, in the polyoxyalkylene-modified silicone, the content of polyoxyethylene groups is preferably less than 25% by mass, more preferably 20% by mass or less, from the viewpoint of ensuring insolubility in water as described above. More preferably, it is 15 mass% or less. In addition, from the viewpoint of sufficiently increasing the expansion coefficient by reducing the interfacial tension sufficiently, the content of the polyoxyethylene group is preferably 1% by mass or more, and preferably 3% by mass or more. More preferably, it is more preferably 5% by mass or more.
The content of the polyoxyalkylene group in the polyoxyalkylene-modified silicone is determined by the following means. First, the molecular weight of the polyoxyalkylene-modified silicone is measured using a mass analyzer or GPC. Further, the polyoxyalkylene-modified silicone is analyzed with an NMR measuring instrument, and the molecular weight of the polyoxyalkylene group is determined based on the data of mass spectrometry. Further, the modification rate is determined from the ratio of the methyl group in the main chain and the connecting portion from the result of the NMR measuring instrument. Then, the content of the polyoxyalkylene group is determined from the molecular weight of the whole and the polyoxyalkylene group and the modification rate.

In the superabsorbent polymer material of the present invention, when the attached liquid film cleaving agent is identified, it is described with a measuring method such as the surface tension (γw) of the above liquid film (liquid having a surface tension of 50 mN / m). Other identification methods can be used.
Further, when the component of the liquid film cleaving agent is a compound having a compound structure in which the main chain contains a silicon atom or a hydrocarbon compound having 1 to 20 carbon atoms, the adhesion ratio (OPU) relative to the mass of the raw material superabsorbent polymer material ) Can be obtained by dividing the content of the liquid film cleaving agent by the mass of the superabsorbent polymer material on the basis of the component mass obtained by the above analytical method.

The raw material superabsorbent polymer material used for forming the superabsorbent polymer material of the present invention is a polymer particle having water absorbency, and is preferably capable of absorbing and holding a liquid 20 times or more of its own weight and capable of gelling. The shape is not particularly limited, and may be spherical, lump, grape-like, indefinite shape, porous, powdery or fibrous.
The average particle size of the raw material superabsorbent polymer material is 100 μm or more and 1000 μm or less, preferably 150 μm or more and 650 μm or less, in order to prevent dropping from the product, suppression of movement or deterioration of feeling of use (roughness). More preferably, it is 200 μm or more and 500 μm or less. The average particle diameter can be determined from the mass fraction of each fraction obtained by classifying 100 g of raw material high-absorption polymer using a sieve according to JIS Z-8801-1982.

  The manufacturing method of the raw material superabsorbent polymer material described above is not particularly limited and can employ a commonly used method. The following method is mentioned as an example. First, at least one selected from the following monomers is polymerized and crosslinked as necessary. The polymerization method is not particularly limited, and various generally known methods such as a reverse phase suspension polymerization method and an aqueous solution polymerization method can be employed. Thereafter, the polymer is obtained by subjecting the polymer to operations such as pulverization and classification as necessary to adjust the polymer to a desired average particle size and, if necessary, treating with inorganic fine particles.

  The monomer used in producing the raw material high-absorption polymer material is a monomer that is water-soluble and has a polymerizable unsaturated group. Specifically, olefinic unsaturated carboxylic acid or salt thereof, olefinic unsaturated carboxylic acid ester, olefinic unsaturated sulfonic acid or salt thereof, olefinic unsaturated phosphoric acid or salt thereof, olefinic unsaturated phosphate ester And vinyl monomers having polymerizable unsaturated groups such as olefinically unsaturated amines, olefinically unsaturated ammonium salts, and olefinically unsaturated amides.

  The superabsorbent polymer material of the present invention can be applied to various fields by making use of the liquid absorption retention function. For example, it is suitably used as a liquid retaining absorbent in an absorbent article used for absorbing liquid discharged from the body such as sanitary napkins, panty liners, disposable diapers, and incontinence pads. The absorber may be in the form of a sheet formed by sandwiching the superabsorbent polymer material of the present invention between two sheets, and the superabsorbent polymer material of the present invention and pulp fiber are mixed and stacked. You may coat | cover with coating sheets, such as tissue paper and a nonwoven fabric.

  An absorbent article including an absorbent body using the superabsorbent polymer material of the present invention is typically configured by sandwiching the absorbent body between a skin-side topsheet and a non-skin-side backsheet. As a constituent member of the absorbent article, a material usually used in the technical field can be used without particular limitation. For example, as the surface sheet, a liquid-permeable soft touch can be used, and examples thereof include various nonwoven fabrics such as an air-through nonwoven fabric. Moreover, a surface sheet may consist of a some nonwoven fabric, and may consist of a combination of a nonwoven fabric and another raw material. As the back sheet, a liquid-impermeable or water-repellent sheet such as a thermoplastic resin film or a laminate of the film and a nonwoven fabric can be used. The back sheet may have water vapor permeability. The absorbent article may further include various members according to specific uses of the absorbent article. Such members are known to those skilled in the art. For example, when applying an absorbent article to a disposable diaper or a sanitary napkin, a pair or two or more pairs of three-dimensional guards can be disposed on the left and right sides of the topsheet.

  The present invention further discloses the following superabsorbent polymer material, absorbent body and absorbent article with respect to the above-described embodiment.

<1>
A superabsorbent polymer material to which a liquid film cleaving agent having an expansion coefficient of 20 mN / m or more and a water solubility of 0 g to 0.025 g is attached to a liquid having a surface tension of 50 mN / m.

<2>
The expansion coefficient of the liquid film cleaving agent is more preferably 25 mN / m or more, and further preferably 30 mN / m or more, and the superabsorbent polymer material according to <1>.
<3>
The superabsorbent polymer material according to <1> or <2>, wherein the liquid film cleaving agent has an interfacial tension of 20 mN / m or less with respect to a liquid having a surface tension of 50 mN / m.
<4>
The interfacial tension of the liquid film cleaving agent with respect to a liquid having a surface tension of 50 mN / m is preferably 20 mN / m or less, more preferably 10 mN / m or less, still more preferably less than 5 mN / m, and particularly preferably 1 mN / m or less. The superabsorbent polymer material according to <1> or <2>, greater than 0 mN / m.

<5>
<1> to <4>, wherein the liquid film cleaving agent comprises a compound having at least one structure selected from the group consisting of structures X, XY, and Y-XY having the following meanings: The superabsorbent polymer material according to any one of the above.
In the structure X, CA <C: carbon atom>, CA ₂ , CAB, CACR ¹ , CR ¹ , CR ¹ R ² , CR ¹ ₂ , and any basic skeleton of SiOR ¹ ₂ , SiOR ¹ R ² are continuous. Or a siloxane chain or a mixed chain formed by combining them, and at the end of the structure X, CA ₃ , CA ₂ B, CAB _2, CA ₂ CR ¹ , CR ¹ ₂ A, CR ¹ ₃ Further, it represents one having at least one structure selected from the group consisting of SiOR ¹ ₃ , SiOR ¹ ₂ R ² , SiR ¹ ₃ , and SiR ¹ ₂ R ² . Each of R ¹ and R ² independently represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, a methoxy group, an ethoxy group, a phenyl group, or a fluorine atom. A and B each independently represent a substituent containing an oxygen atom or a nitrogen atom.
The structure Y represents a hydrophilic group having hydrophilicity including an atom selected from H, C, O, N, P, and S.
<6>
The superabsorbent polymer material according to <5>, wherein A and B are each independently a hydroxyl group, a carboxylic acid group, an amino group, an amide group, an imino group, or a phenol group.
<7>
Any of <1> to <6> above, wherein the liquid film cleaving agent comprises a compound having a chemical structure composed of Si molecules arbitrarily combining skeletons represented by the following formulas (1) to (11): The superabsorbent polymer material according to claim 1.

式（１）〜（１１）において、Ｍ^１、Ｌ^１、Ｒ^２１、Ｒ^２２、Ｒ^２３、及びＲ^２４は次の１価又は多価の基を表す。
Ｍ^１は、ポリオキシエチレン基、ポリオキシプロピレン基、ポリオキシブチレン基、もしくはそれらを組み合わせたポリオキシアルキレン基を有する基や、エリスリトール基、キシリトール基、ソルビトール基、グリセリン基もしくはエチレングリコール基、水酸基、カルボン酸基、メルカプト基、メトキシ基、アミノ基、アミド基、イミノ基、フェノール基、スルホン酸基、4級アンモニウム基、スルホベタイン基、ヒドロキシスルホベタイン基、ホスホベタイン基、イミダゾリウムベタイン基、カルボベタイン基、エポキシ基、カルビノール基、メタクリル基、又はそれらを組み合わせた官能基を表す。
Ｌ^１は、エーテル基、アミノ基、アミド基、エステル基、カルボニル基、カーボネート基の結合基を表す。
Ｒ^２１、Ｒ^２２、Ｒ^２３、及びＲ^２４は各々独立に、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、ペンチル基、ヘキシル基、ヘプチル基、２エチル−ヘキシル基、ノニル基、デシル基、メトキシ基、エトキシ基、フェニル基、フルオロアルキル基、もしくはアラルキル基、又はそれらを組み合わせた炭化水素基、又はフッ素原子を表す。

In the formulas (1) to (11), M ¹ , L ¹ , R ²¹ , R ²² , R ²³ , and R ²⁴ represent the following monovalent or polyvalent groups.
M ¹ is a group having a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, or a polyoxyalkylene group obtained by combining them, an erythritol group, a xylitol group, a sorbitol group, a glycerin group or an ethylene glycol group, a hydroxyl group Carboxylic acid group, mercapto group, methoxy group, amino group, amide group, imino group, phenol group, sulfonic acid group, quaternary ammonium group, sulfobetaine group, hydroxysulfobetaine group, phosphobetaine group, imidazolium betaine group, It represents a carbobetaine group, an epoxy group, a carbinol group, a methacryl group, or a functional group combining them.
L ¹ represents a bonding group of an ether group, an amino group, an amide group, an ester group, a carbonyl group, or a carbonate group.
R ²¹ , R ²² , R ²³ , and R ²⁴ are each independently a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethyl-hexyl group, a nonyl group, It represents a decyl group, a methoxy group, an ethoxy group, a phenyl group, a fluoroalkyl group, an aralkyl group, a hydrocarbon group obtained by combining them, or a fluorine atom.

式中、Ｒ^３１はメチル基、エチル基、プロピル基、イソプロピル基、ブチル基、ペンチル基、ヘキシル基、ヘプチル基、２エチル−ヘキシル基、ノニル基、デシル基を表し、Ｒ^３２はメチレン基、エチレン基、プロピレン基、ブチレン基、Ｎ−（アミノエチル）メチルイミノ基、又はＮ−（アミノプロピル）プロピルイミノ基を表す。複数のＲ^３１、複数のＲ^３２は各々において、互いに同一であるか、異なっている。Ｍ^１１はポリオキシアルキレン基を表す。上記のポリオキシアルキレン基としては、ポリオキシエチレン基、ポリオキシプロピレン基、ポリオキシブチレン基、及びこれ等の構成モノマーが共重合されたものである。ｍ及びｎは各々独立に１以上の整数を表す。 <8>
The superabsorbent polymer material according to any one of <5> to <7>, wherein the liquid film cleaving agent is made of polyoxyalkylene-modified silicone.
<9>
The superabsorbent polymer material according to <8>, wherein the polyoxyalkylene-modified silicone is represented by any one of the following general formulas [I] to [IV].

In the formula, R ³¹ represents a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethyl-hexyl group, a nonyl group, or a decyl group, and R ³² represents a methylene group, An ethylene group, a propylene group, a butylene group, an N- (aminoethyl) methylimino group, or an N- (aminopropyl) propylimino group is represented. The plurality of R ³¹ and the plurality of R ³² are the same as or different from each other. M ¹¹ represents a polyoxyalkylene group. As said polyoxyalkylene group, a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, and these structural monomers are copolymerized. m and n each independently represents an integer of 1 or more.

式中、Ｒ^３１はメチル基、エチル基、プロピル基、イソプロピル基、ブチル基、ペンチル基、ヘキシル基、ヘプチル基、２エチル-ヘキシル基、ノニル基、デシル基を表し、Ｒ^３２はメチレン基、エチレン基、プロピレン基、ブチレン基、Ｎ-（アミノエチル）メチルイミノ基、又はＮ-（アミノプロピル）プロピルイミノ基を表す。複数のＲ^３１、複数のＲ^３２は各々において、互いに同一であるか、異なっている。Ｍ^１１はポリオキシアルキレン基を有する基を表す。上記のポリオキシアルキレン基としては、ポリオキシエチレン基、ポリオキシプロピレン基、ポリオキシブチレン基、及びこれ等の構成モノマーが共重合されたものである。ｍ及びｎは各々独立に１以上の整数を表す。 <10>
A superabsorbent polymer material having a structure represented by any one of the following general formulas [I] to [IV], to which a liquid film cleaving agent having a water solubility of 0 g or more and 0.025 g or less is attached.

In the formula, R ³¹ represents a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethyl-hexyl group, a nonyl group, or a decyl group, and R ³² represents a methylene group, An ethylene group, a propylene group, a butylene group, an N- (aminoethyl) methylimino group, or an N- (aminopropyl) propylimino group is represented. The plurality of R ³¹ and the plurality of R ³² are the same as or different from each other. M ¹¹ represents a group having a polyoxyalkylene group. As said polyoxyalkylene group, a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, and these structural monomers are copolymerized. m and n each independently represents an integer of 1 or more.

<11>
<8, wherein the polyoxyalkylene-modified silicone is any one of polyoxyethylene (POE) polyoxypropylene (POP) -modified silicone, polyoxyethylene (POE) -modified silicone, and polyoxypropylene (POP) -modified silicone. The superabsorbent polymer material according to any one of> to <10>.
<12>
The added mole number of the polyoxyalkylene group of the polyoxyalkylene-modified silicone is preferably 1 or more, more preferably 3 or more, still more preferably 5 or more, and the added mole number is preferably 30 or less, more preferably 20 or less, The superabsorbent polymer material according to any one of <8> to <10>, further preferably 10 or less.

<13>
The water solubility of the liquid film cleaving agent is preferably 0.020 g or less, more preferably 0.015 g or less, still more preferably 0.010 g or less, and preferably 0.005 g or more, <1> to < The superabsorbent polymer material according to any one of 12>.

<14>
The liquid film cleaving agent is the superabsorbent polymer material according to any one of <1> to <13>, wherein the main chain is made of a compound containing Si atoms.
<15>
The superabsorbent polymer material according to any one of <1> to <14>, wherein the liquid film cleaving agent comprises polyoxyalkylene-modified silicone.
<16>
The polyoxyalkylene group of the polyoxyalkylene-modified silicone has at least one selected from the group consisting of a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, and a group obtained by copolymerizing these constituent monomers. The superabsorbent polymer material according to <15>.
<17>
The superabsorbent polymer material according to <15> or <16>, in which the polyoxyethylene group content of the polyoxyalkylene-modified silicone is less than 25% by mass.

<18>
The superabsorbent polymer material according to any one of <1> to <17>, wherein the liquid film cleaving agent has a surface tension of 30 mN / m or less.
<19>
The surface tension of the liquid film cleaving agent is preferably 30 mN / m or less, more preferably 25 mN / m or less, further preferably 22 mN / m or less, and preferably 1 mN / m or more, any one of <1> to <17> The superabsorbent polymer material according to claim 1.
<20>
The superabsorbent polymer material according to any one of <1> to <19>, wherein the liquid film cleaving agent has a mass average molecular weight of 500 or more.
<21>
The liquid film cleaving agent has a mass average molecular weight of 500 or more, more preferably 1000 or more, further preferably 1500 or more, preferably 50000 or less, more preferably 20000 or less, still more preferably 10,000 or less, <1> to < The superabsorbent polymer material according to any one of 19>.

<22>
The absorber using the superabsorbent polymer material of any one of said <1>-<21>.
<23>
An absorbent article using the superabsorbent polymer material according to any one of <1> to <21>.
<24>
The absorbent article according to <23>, wherein the absorbent article is a sanitary napkin.

  EXAMPLES Hereinafter, although this invention is demonstrated in more detail based on an Example, this invention is limited to this and is not interpreted. In the examples, “part” and “%” are based on mass unless otherwise specified.

Example 1
(1) Preparation of coating liquid Polyoxyethylene (POE) -modified dimethyl silicone (manufactured by Shin-Etsu Chemical Co., Ltd., KF-6015 (trade name)) was used as a liquid film cleaving agent. 1.25 g of the liquid film cleaving agent was mixed with 48.75 g of ethanol as a solvent to prepare 50 g of a 2.5 wt% coating solution.
The polyoxyethylene (POE) -modified dimethyl silicone is a dimethyl silicone chain in which X in the structure XY is composed of SiOC ₂ H ₆ , and Y is composed of a POE chain composed of C ₂ H ₄ O. POA) The number of added moles was 3, and the mass average molecular weight was 4000.
This polyoxyethylene (POE) modified dimethyl silicone has an expansion coefficient of 29 mN / m for a liquid having a surface tension of 50 mN / m, and the surface tension of polyoxyethylene (POE) modified dimethyl silicone is 21 mN / m. The interface tension of the (POE) -modified dimethyl silicone with respect to a liquid having a surface tension of 50 mN / m was 0.2 mN / m, and the water solubility was 0.025 g or less. These numerical values were measured by the measurement method described above. At that time, the “liquid with a surface tension of 50 mN / m” is a nonionic surfactant polyoxyethylene sorbitan monolaurate (trade name: Leo Super TW-L120, manufactured by Kao Corporation) in ion-exchanged water. A solution containing 15% by mass was used.
(2) Preparation of sample of superabsorbent polymer material of Example 1 Next, as a raw material superabsorbent polymer material, “Laurier water absorption free day deodorant plus slim type napkin for small to medium amount” (trade name) manufactured by Kao Corporation A superabsorbent polymer material taken out from the absorber was prepared, and the above-mentioned coating solution was adhered to the raw superabsorbent polymer material as follows. That is, 2.5 g of the raw material high-absorption polymer material is first collected, and then 1.0 g of the coating solution is dropped onto the raw material high-absorption polymer material, and after sufficiently shaking, 1.0 wt% POE is dried. Modified silicone was adhered to the raw material superabsorbent polymer material.
As a result, the adhesion ratio of the liquid film cleaving agent was 1.0% by mass with respect to the mass of the raw material superabsorbent polymer material. The adhesion ratio of the liquid film cleaving agent can be determined by dividing the content of the liquid film cleaving agent by the mass of the raw material superabsorbent polymer material based on the component mass obtained by using the identification method described above. .

(Example 2)
The superabsorbent polymer material of Example 2 in the same manner as in Example 1 except that the treatment amount of polyoxyethylene (POE) -modified dimethyl silicone, which is the liquid film cleaving agent used in Example 1, was changed to 3.0% by mass. A sample of was prepared.
Preparation of the coating liquid in this case used polyoxyethylene (POE) modified dimethyl silicone (manufactured by Shin-Etsu Chemical Co., Ltd., KF-6015 (trade name)) as a liquid film cleaving agent. 3.75 g of the liquid film cleaving agent was mixed with 46.25 g of ethanol as a solvent to prepare 50 g of a 7.5 wt% coating solution. Thereafter, as the raw material high-absorption polymer material, the high-absorption polymer taken out from the absorber of “Laurier water absorption free day deodorization plus slim type napkin for small to medium amount” manufactured by Kao Corporation is collected, and the raw material high-absorption polymer material The above-mentioned coating liquid was adhered as follows. That is, 2.5 g of the raw material high-absorption polymer material is first collected, and then 1.0 g of the coating solution is dropped onto the raw material high-absorption polymer material, sufficiently shaken and then dried to obtain 3.0 wt%. POE-modified silicone was adhered to the raw material superabsorbent polymer material.

(Example 3)
The superabsorbent polymer material of Example 3 in the same manner as in Example 1 except that the treatment amount of polyoxyethylene (POE) -modified dimethyl silicone, which is the liquid film cleaving agent used in Example 1, was changed to 0.5% by mass. A sample of was prepared.
Preparation of the coating liquid in this case used polyoxyethylene (POE) modified dimethyl silicone (manufactured by Shin-Etsu Chemical Co., Ltd., KF-6015 (trade name)) as a liquid film cleaving agent. 1.25 g of the liquid film cleaving agent was mixed with 98.75 g of ethanol as a solvent to prepare 100 g of a 1.25 wt% coating solution. Thereafter, as the raw material high-absorption polymer material, the high-absorption polymer taken out from the absorber of “Laurier water absorption free day deodorization plus slim type napkin for small to medium amount” manufactured by Kao Corporation is collected, and the raw material high-absorption polymer material The above-mentioned coating liquid was adhered as follows. That is, 2.5 g of the raw material high-absorption polymer material is first collected, and then 1.0 g of the coating solution is dropped onto the raw material high-absorption polymer material, and after shaking sufficiently, 0.5 wt% POE-modified silicone was adhered to the raw material superabsorbent polymer material.

Example 4
The superabsorbent polymer material of Example 4 in the same manner as in Example 1 except that the treatment amount of polyoxyethylene (POE) -modified dimethyl silicone, which is the liquid film cleaving agent used in Example 1, was 0.1% by mass. A sample of was prepared.
Preparation of the coating liquid in this case used polyoxyethylene (POE) modified dimethyl silicone (manufactured by Shin-Etsu Chemical Co., Ltd., KF-6015 (trade name)) as a liquid film cleaving agent. 0.25 g of the liquid film cleaving agent was mixed with 99.75 g of ethanol as a solvent to prepare 100 g of a 0.25 wt% coating solution. Thereafter, as the raw material high-absorption polymer material, the high-absorption polymer taken out from the absorber of “Laurier water absorption free day deodorization plus slim type napkin for small to medium amount” manufactured by Kao Corporation is collected, and the raw material high-absorption polymer material The above-mentioned coating liquid was adhered as follows. That is, 2.5 g of the raw material superabsorbent polymer material is first collected, and then 1.0 g of the coating solution is dropped onto the raw material superabsorbent polymer material, and after shaking sufficiently, 0.1 wt% POE-modified silicone was adhered to the raw material superabsorbent polymer material.

(Example 5)
(1) Preparation of coating liquid Polyoxypropylene (POP) -modified dimethyl silicone (obtained by hydrosilylation reaction of silicone oil and hydrocarbon compound) was used as a liquid film cleaving agent. 1.25 g of the liquid film cleaving agent was mixed with 48.75 g of ethanol as a solvent to prepare 50 g of a 2.5 wt% coating solution.
The polyoxypropylene (POP) -modified dimethylsilicone is composed of a dimethylsilicone chain in which X in the structure XY is composed of SiOC ₂ H ₆ and a POP chain in which Y is composed of C ₃ H ₆ O. POP) The number of added moles was 3, and the mass average molecular weight was 4000.
This polyoxypropylene (POP) modified dimethyl silicone has an expansion coefficient of 25 mN / m for a liquid having a surface tension of 50 mN / m, and the polyoxypropylene (POP) modified dimethyl silicone has a surface tension of 21 mN / m. The interfacial tension of the (POP) -modified dimethyl silicone with respect to a liquid having a surface tension of 50 mN / m was 3.6 mN / m, and the water solubility was 0.025 g or less. These numerical values were measured by the same method as in Example 1.
(2) Preparation of sample of superabsorbent polymer material of Example 5 Example similar to Example 1 except that the above coating liquid was used and the adhesion ratio of the liquid film cleaving agent was 1.0% by mass. Samples of 5 superabsorbent polymer materials were prepared.

(Comparative Example 1)
The raw material superabsorbent polymer material used in Example 1 was used as the sample of Comparative Example 1 as it was, that is, without a liquid film cleaving agent.

(Comparative Example 2)
Polyoxyethylene sorbitan monostearate (Reodol TW-S120V manufactured by Kao Corporation) shown in Example 7 described in Patent Document 1 (International Publication No. 2012/133734), not a liquid film cleaving agent coating solution The sample of Comparative Example 2 was prepared in the same manner as in Example 1 except that the surfactant ethanol solution was used as the coating solution. That is, it was prepared using 2.5 g of the raw polymer material, and the adhesion ratio of polyoxyethylene sorbitan monostearate to the mass of the raw superabsorbent polymer material was 1.0% by mass.
The polyoxyethylene sorbitan monostearate is different from the liquid film cleaving agent of each example in that it is a surfactant having solubility in water (that is, water solubility is more than 0.025 g). It was.

(Comparative Example 3)
Interface of sodium polyoxyethylene lauryl sulfate (Emal 20C manufactured by Kao Corporation) shown in Example 11 described in Patent Document 1 (International Publication No. 2012/133734), not a liquid film cleaving agent coating solution A sample of Comparative Example 3 was prepared in the same manner as Example 4 except that the activator ethanol solution was used as the coating solution. That is, it was prepared using 2.5 g of the raw material polymer material, and the adhesion ratio of polyoxyethylene sodium lauryl sulfate to the mass of the raw material superabsorbent polymer material was 1.0% by mass.
In addition, polyoxyethylene lauryl sodium sulfate was different from the liquid film cleaving agent in each example in that it was a surfactant having solubility in water (that is, water solubility was more than 0.025 g). .

(Comparative Example 4)
Instead of a liquid film cleaving agent coating solution, a surfactant ethanol solution of polyoxyethylene-modified silicone shown in Example 11 described in Patent Document 2 (Japanese Patent Laid-Open No. 8-289903) is used as the coating solution. A sample of Comparative Example 4 was produced in the same manner as in Example 1 except that. That is, it was prepared using 2.5 g of the raw polymer material, and the adhesion ratio of the polyoxyethylene-modified silicone to the total mass of the obtained sample was 1.0% by mass.
The polyoxyethylene (POE) -modified silicone is an interface between the liquid film cleaving agent of each example and a polyoxyethylene (POE) having an average molecular weight of about 1000, which has a large modification rate of 50% and is soluble in water. It was different in that it was an activator (ie water solubility greater than 0.025 g).

(Comparative Example 5)
Polypropylene glycol (PPG) (anti-foaming agent No. 1 manufactured by Kao Corporation) having an expansion coefficient of less than 20 was used. Sample of Comparative Example 5 in the same manner as in Example 1 except that 1.25 g of the polypropylene glycol was mixed with 48.75 g of ethanol as a solvent, and 50 g of 2.5 wt% coating solution was used as the coating solution. Was made. That is, it was prepared using 2.5 g of the raw material polymer material, and the adhesion ratio of polypropylene glycol to the mass of the raw material superabsorbent polymer material was 1.0% by mass.
The polypropylene glycol was such that X in the structure X was a POP chain, the number of added polyoxyalkylene (POA) was 10, and the mass average molecular weight was 3000.
This polypropylene glycol has an expansion coefficient of 17 mN / m for a liquid having a surface tension of 50 mN / m, the surface tension of polypropylene glycol is 33 mN / m, and the interfacial tension of polypropylene glycol for a liquid having a surface tension of 50 mN / m is 1. 0.0 mN / m, and the water solubility was 0.025 g or less. These numerical values were measured by the same method as in Example 1.

(Comparative Example 6)
A polyoxypropylene (POP) alkyl ether (Kao Corporation, antifoam No. 8) having an expansion coefficient of less than 20 was used. Except that 1.25 g of the polyoxypropylene (POP) alkyl ether was mixed with 48.75 g of ethanol as a solvent, and 50 g of 2.5 wt% coating solution was used as the coating solution, the same as in Example 1. Thus, a sample of Comparative Example 5 was produced. That is, it was prepared using 2.5 g of the raw polymer material, and the adhesion ratio of the polyoxypropylene (POP) alkyl ether to the mass of the raw superabsorbent polymer material was 1.0% by mass.
The polyoxypropylene (POP) alkyl ether had a polyoxypropylene addition mole number of 5 and a mass average molecular weight of 500.
The polyoxypropylene (POP) alkyl ether has an expansion coefficient of 14 mN / m for a liquid having a surface tension of 50 mN / m, the surface tension of the polyoxypropylene (POP) alkyl ether is 30 mN / m, and a polyoxypropylene (POP). ) The interfacial tension of the alkyl ether with respect to a liquid having a surface tension of 50 mN / m was 5.9 mN / m, and the water solubility was 0.025 g or less. These numerical values were measured by the same method as in Example 1.

(Evaluation test)
1. Artificial urine having the following composition was used as the “liquid flow rate under pressure for a liquid having a surface tension of 50 mN / m” as “liquid having a surface tension of 50 mN / m”. That is, the composition of the artificial urine is 1.94% by mass of urea, 0.795% by mass of sodium chloride, 0.11% by mass of magnesium sulfate, 0.062% by mass of calcium chloride, 0.197% by mass of potassium sulfate, red 2 No. (dye) 0.010% by mass, water 96.88% by mass and polyoxyethylene lauryl ether (about 0.07% by mass), with the surface tension adjusted to 53 ± 1 dyne / cm (23 ° C.) Using.
In a 100 mL glass beaker, 0.32 ± 0.005 g of each superabsorbent polymer material that is a measurement sample is an amount of the artificial urine sufficient to swell, for example, at least five times the saturated absorption amount of the superabsorbent polymer material. And soaked in artificial urine for 30 minutes.
Separately, at the lower end of an opening of a vertically standing cylinder (inner diameter 25.4 mm), a wire mesh (mesh opening 150 μm, biocolumn sintered stainless steel filter 30SUS sold by Sansho Co., Ltd.) and a capillary (with an inner diameter of 2 mm) ( A filtration cylindrical tube having an inner diameter of 4 mm and a length of 8 cm) was prepared, and the contents of the beaker including the swollen measurement sample were put into the cylindrical tube with the cock closed. Next, a cylindrical rod having a diameter of 2 mm with a wire mesh having an opening of 150 μm and a diameter of 25 mm is inserted into the filtration cylindrical tube so that the wire mesh and the measurement sample are in contact with each other. The weight was placed so that the load of. After standing for 1 minute in this state, the cock is opened to flow the liquid, and the time until the liquid level in the filtration cylindrical tube reaches the 40 mL scale line from the 60 mL scale line (that is, 20 mL of liquid passes) (T1). (Seconds) was measured. Using the measured time T1 (seconds), the flow rate at 2.0 kPa was calculated from the following equation. In the equation, T0 (seconds) is a value obtained by measuring the time required for 20 ml of the artificial urine to pass through the wire mesh without putting the measurement sample in the filtering cylindrical tube.
Flow rate (ml / min) = 20 × 60 / (T1-T0)
The value obtained by the above formula was divided by the thickness of the swollen water-absorbing polymer layer in the cylinder, and converted into a value per 20 mm to obtain the liquid passing speed under pressure. The measurement was performed 5 times (n = 5), the values at each of the upper and lower points were deleted, and the average value of the remaining three points was taken as the measured value. In addition, said "2.0 kPa" has shown the average pressure normally applied by body pressure etc. when mounting | wearing the absorbent article incorporating the absorber containing a superabsorbent polymer material as above-mentioned.
A more detailed method for measuring the flow rate was the method described in paragraphs 0008 and 0009 of JP-A-2003-235889. The same measuring apparatus as that described in FIGS. 1 and 2 of the same publication was used.

2. The saturated absorption amount under pressure for a liquid with a surface tension of 50 mN / m and the centrifugal retention amount under pressure for a liquid with a surface tension of 50 mN / m (1) The saturated absorption amount under pressure is described in JP-A-2003-235889. The measurement was performed using the measuring method and measuring apparatus. Specifically, the measurement was performed as follows in an environment of 25 ± 2 ° C. and a relative humidity of 50% ± 5%.
That is, 0.20 g of a sample (superabsorbent polymer material) was weighed in a cylindrical plastic tube (inner diameter: 30 mm, height: 60 mm) with a nylon mesh (JIS Z8801-1: 2000) having a mesh opening of 63 μm attached to the bottom surface. The plastic tube is placed vertically on a nylon mesh so that the sample has a uniform thickness, and a weight of 29.5 mm in outer diameter and 22 mm in thickness is placed inside the cylindrical plastic tube so that 2.0 kPa is applied to the sample. Inserted into. The mass of the cylindrical plastic tube and the weight was measured in advance.
Next, a cylindrical plastic tube containing a sample and a weight was immersed vertically in a petri dish (diameter: 120 mm) containing 60 ml of artificial urine with the nylon mesh side as the bottom surface. At this time, the cylindrical plastic tube was immersed to the depth of the bottom of the petri dish. After 60 minutes, the cylindrical plastic tube containing the sample and the weight is pulled up from the artificial urine, and the mass is weighed. The mass of the cylindrical plastic tube and the weight previously measured is subtracted, and the mass of the artificial urine absorbed by the sample is calculated. Calculated. A value obtained by multiplying the mass of the absorbed artificial urine by 5 is defined as an absorption amount under pressure (g / g). In addition, the measurement was performed 5 times (n = 5), the values at each of the upper and lower points were deleted, and the average value of the remaining three points was taken as the measured value. The measurement was performed at 23 ± 2 ° C. and humidity 50 ± 5%, and the sample was measured after being stored in the same environment for 24 hours or more.
(2) The measurement of the centrifugal retention amount under pressure is carried out by using a nylon woven fabric (mesh opening 255, sold by Sanriki Manufacturing Co., Ltd., product name: nylon net, standard: 250 × mesh width × 30m) is cut into a rectangle 10cm wide and 40cm long and folded in the middle in the longitudinal direction. Both ends are heat-sealed and put into a nylon bag 10cm wide (9cm inner size) and 20cm long. Then, it was placed uniformly at the bottom of the produced nylon bag. After suspending in a vertical state for 1 hour and draining, it was dehydrated using a centrifugal dehydrator (Kokusan Co., Ltd., model H-130C special model). The dehydrating condition was 143 G (800 rpm) for 10 minutes. After dehydration, the mass of the sample was measured, and the target centrifugal retention amount was calculated according to the following formula.
Centrifugal retention amount (g / g) = (a′−b−0.2) /0.2
Where a ′ is the total mass (g) of the sample and the nylon bag after centrifugal dehydration, b is the mass (g) of the nylon bag before water absorption (when dried), and 0.2 is before water absorption of the sample (when dried) ) Mass (g).
The measurement was performed 5 times (n = 5), the values at each of the upper and lower points were deleted, and the average value of the remaining three points was taken as the measured value. The measurement was performed at 23 ± 2 ° C. and humidity 50 ± 5%, and the sample was measured after being stored in the same environment for 24 hours or more.

  The results of the above evaluation tests for each example and comparative example are shown in Tables 1 and 2 below.

As can be seen from the results in Tables 1 and 2 above, the samples to which the liquid film cleaving agent having an expansion coefficient of 20 mN / m or more in Examples 1 to 5 was adhered had an improved absorption rate under pressure for a liquid of 50 mN / m. It was superior to the samples of Comparative Examples 1-6. In particular, the sample of Example 1 with a POE-modified silicone having an expansion coefficient of 29 mN / m and having an adhesion ratio of 1.0 wt% showed an excellent liquid passing rate under pressure. Further, in Examples 1 to 5, although the liquid film cleaving agent is attached to the surface of the superabsorbent polymer material, the saturated absorption amount under pressure and the centrifugal retention amount under pressure are uncoated products (Comparative Example 1). The performance has been maintained with almost no change. In addition, the sample in which 1.0 wt% of 25 mN / m POP-modified silicone having an expansion coefficient smaller than that of POE-modified silicone in Example 5 was not as large as that in Example 1, but more than Comparative Examples 1-6. It showed high performance with respect to the flow rate under pressure, and showed excellent performance among the examples with respect to the saturated absorption amount and the centrifugal retention amount under pressure.
On the other hand, the sample using the polyoxyethylene sorbitan monostearate soluble in water of Comparative Example 2 and the surfactants of polyoxyethylene sodium lauryl sulfate and water-soluble modified silicone of Comparative Examples 3 and 4 In the sample using, the performance of the raw material superabsorbent polymer material (Comparative Example 1) was deteriorated in all of the flow rate under pressure, the saturated absorption amount under pressure, and the centrifugal retention amount under pressure. Further, in the samples using Comparative Examples 5 and 6, which are oils having a small expansion coefficient, polyoxypropylene glycol or polyoxypropylene alkyl ether, improvement in the flow rate under pressure as in Examples was not observed, There was no improvement in the amount of saturated absorption and centrifugal retention under pressure.
Based on the above, the highly absorbent polymer material to which the liquid membrane cleaving agent having a high expansion coefficient and low solubility in water is attached is considered to be excellent by improving the liquid flow rate under pressure, and saturated absorption under pressure. It turns out that it is effective in coexistence with the performance with a high quantity and the amount of centrifugal retention under pressure.

1 Superabsorbent polymer material 2 Liquid film 3 Liquid film cleaving agent

Claims (5)

  A superabsorbent polymer material to which a liquid film cleaving agent having an expansion coefficient of 20 mN / m or more and a water solubility of 0 g to 0.025 g is attached to a liquid having a surface tension of 50 mN / m.   The superabsorbent polymer material according to claim 1, wherein the liquid film cleaving agent has an interfacial tension of 20 mN / m or less for a liquid having a surface tension of 50 mN / m.   The superabsorbent polymer material according to claim 1 or 2, wherein the liquid film cleaving agent comprises polyoxyalkylene-modified silicone.   The polyoxyalkylene group of the polyoxyalkylene-modified silicone is at least one selected from the group consisting of a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, and a group obtained by copolymerizing these constituent monomers. Item 4. The superabsorbent polymer material according to Item 3.   The superabsorbent polymer material according to claim 3 or 4, wherein the polyoxyethylene group content of the polyoxyalkylene-modified silicone is less than 25% by mass.

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