RU2750252C2 - Non-woven material - Google Patents

Abstract

FIELD: non-woven textile materials.SUBSTANCE: present invention relates to a non-woven material. A method is proposed for producing a non-woven material containing at least one type of fiber selected from hot-melt composite fibers of the shell-core type, thermally elongated fibers, thermally non-elongated fibers, heat-shrinkable fibers, fibers without thermal shrinkage, three-dimensional twisted fibers, potentially twisted fibers and hollow fibers, including the stage of applying a liquid coating to a non-woven material from the source materials using a flexographic printing system, wherein the liquid coating contains a liquid film breaking agent and has a viscosity of 25 сP or more, and wherein the nonwoven material from the starting materials has a concave part and a high-density part, and the high-density part is located at the bottom of the concave part and has a fiber density higher than the fiber density in any other part; wherein the film breaking agent is: at least one type of compound selected from organically modified silicone, polyatomic alcohol and fatty acid ester, and wax selected from ceresine, paraffin, vaseline, mineral oil, and liquid isoparaffin, and represented by the following formula: CmHn[XV]; and has a spreading coefficient of 15 mN/m or greater for a liquid having a surface tension of 50 mN/m, or has a spreading coefficient greater than 0 mN/m for a liquid having a surface tension of 50 mN/ m, and a tension of 20 mN/m or less at the interface with a liquid having a surface tension of 50 mN/m. Also described is a method for producing a non-woven material (options), a non-woven material for an absorbent product (options), an absorbent product, an upper sheet of an absorbent product.EFFECT: providing suppression of the liquid volume in the lower part of the concave part recessed in the direction of the thickness of the non-woven material, and reducing the liquid film formed between the fibers, with the achievement of reducing the residual liquid content at a higher level.28 cl, 2 tbl, 7 dwg, 13 ex

Description

The technical field to which the invention relates

{0001}

The present invention relates to a nonwoven fabric.

State of the art

{0002}

Nonwoven fabric for use as a topsheet for an absorbent article or the like has been the subject of various innovations regarding liquid permeability. For example, attempts are being made to increase the suction power of a liquid by imparting a convex-concave structure to the nonwoven fabric and imparting a gradient in the degree of hydrophilicity of the concavities and bulges forming the convex-concave structure (for example, Patent Literature 1).

In addition, another topsheet for an absorbent article is described in which a skin care agent is coated on the low density portion for the convex portion of the convex-concave structure of the nonwoven fabric, so that the skin care agent can be even more reliable. come into contact with the skin (eg Patent Literatures 2 and 3).

Citation List

Patent Literature

{0003}

Patent Literature 1: JP-A-2006-183168 ("JP-A" means Japanese Unexamined Published Patent Application)

Patent Literature 2: JP-A-2011-131044

Patent Literature 3: JP-A-2012-55409

The essence of the invention

{0004}

The present invention provides a nonwoven fabric comprising a concave portion and a high density portion that is located at the bottom of the concave portion and has a fiber density higher than the fiber density in any other portion where the nonwoven fabric is divided into a high density portion and a non-high density portion other than the high density portion, and the nonwoven fabric contains an agent for breaking the liquid film in the non-high density portion.

In addition, the present invention provides a nonwoven fabric having a concave portion and a high density portion that is located at the bottom of the concave portion and has a fiber density higher than the fiber density in any other portion where the nonwoven fabric is divided into a high density portion and a non-woven portion. having a high density other than the high density portion, and the nonwoven fabric contains the following C1 compound in the non-high density portion.

[Connection C1]

A compound having a spreading coefficient of 15 mN / m or more for a liquid having a surface tension of 50 mN / m.

In addition, the present invention provides a nonwoven fabric having a concave portion and a high density portion that is located at the bottom of the concave portion and has a fiber density higher than the fiber density in any other portion where the nonwoven fabric is divided into a high density portion and a non-woven portion. having a high density other than the high density portion, and the nonwoven fabric contains the following C2 compound in the non-high density portion.

[Compound C2]

A compound having a spreading coefficient greater than 0 mN / m for a liquid having a surface tension of 50 mN / m and a tension at an interface with a liquid having a surface tension of 50 mN / m, 20 mN / m or less.

{0005}

In addition, the present invention provides a method for producing a nonwoven fabric comprising the step of liquid coating a nonwoven fabric from raw materials using a flexographic printing system, where the liquid coating contains the next compound C1 and has a viscosity of 25 cps or more, and wherein the raw material nonwoven has a concave portion and a high density portion, and a high density portion is located at the bottom of the concave portion and has a fiber density higher than the fiber density in any other portion.

[Connection C1]

A compound having a spreading coefficient of 15 mN / m or more for a liquid having a surface tension of 50 mN / m.

In addition, the present invention provides a method for producing a nonwoven fabric comprising the step of liquid coating a nonwoven fabric from raw materials using a flexographic printing system, wherein the liquid coating contains the following C2 compound and has a viscosity of 25 cps or more, and wherein the nonwoven fabric from raw materials has a concave portion and a high density portion, and the high density portion is located at the bottom of the concave portion and has a fiber density higher than that of any other portion.

[Compound C2]

A compound having a spreading coefficient greater than 0 mN / m for a liquid having a surface tension of 50 mN / m and a tension at an interface with a liquid having a surface tension of 50 mN / m, 20 mN / m or less.

{0006}

Other and additional objects, features and advantages of the present invention will become more apparent from the following description, with appropriate reference to the accompanying drawings.

Brief Description of Drawings

{0007}

{Fig. 1}

Fig. 1 is a perspective view of a nonwoven fabric showing a preferred embodiment of the nonwoven fabric of the present invention.

{Fig. 2}

FIG. 2 is a cross-sectional view taken along line II-II of the nonwoven fabric shown in FIG. 1. FIG.

{Fig. 3}

Fig. 3 is a diagram showing a liquid film formed in the spaces between fibers of a nonwoven fabric.

{Fig. 4}

Figures 4 (A1) to 4 (A4) each are explanatory drawings schematically showing a side view of a state in which the liquid film breaking agent of the present invention breaks the liquid film, and Figures 4 (B1) to 4 (B4) each are explanatory drawings schematically showing from above a state in which the liquid film breaking agent of the present invention breaks the liquid film.

{Fig. 5}

5 is a cross-sectional view of a nonwoven fabric showing a preferred aspect (first aspect) of the nonwoven fabric of the present invention.

{Fig. 6}

6 is a perspective view schematically showing another preferred aspect (second aspect) of the partially cut-away nonwoven fabric of the present invention.

{Fig. 7}

7 is a perspective view schematically showing another preferred aspect (third aspect) of the nonwoven fabric of the present invention.

Description of embodiments

{0008}

The present invention relates to a nonwoven fabric that can retain a liquid volume at the bottom of a concave portion recessed in the direction along the thickness of the nonwoven fabric and to reduce the liquid film formed between the fibers to achieve a higher level of residual liquid reduction, and a method for producing non-woven fabric.

{0009}

The nonwoven fabric has a narrow area between the fibers that is formed by weaving or thermal fusing the fibers together. In this area, although there is a space into which fluid can enter (for example, urine and menstrual blood, which below is also referred to simply as fluid), a high meniscus force between fibers, high surface activity of plasma proteins or high blood surface viscosity causes a stable film to form fluid between the fibers, resulting in fluid retention in that area. Therefore, also in accordance with conventional technology, in an attempt to increase the liquid permeability, the liquid film cannot be completely dissolved, and there is still room for improving the feeling of dry skin. In addition, in addition to feeling dry skin, consumers have recently also shown a desire for good texture, which requires the use of fine fibers. However, if thin fibers are used, the distance between the fibers is further reduced. Thus, since the liquid film between the fibers is even easier to form and more difficult to break, the liquid retention tends to increase.

In addition, this phenomenon is not limited to blood as a liquid to be absorbed, and phospholipids in urine also exhibit surface activity in which a liquid film is formed in the same manner as described above, and there is still room for improving the feeling of dry skin.

Therefore, a method is contemplated for eliminating a liquid film formed in a narrow portion between fibers, or, in the case where the fibers are thinned, in a nonwoven fabric. However, elimination is difficult due to the high stability of the liquid film. In addition, it is also expected to eliminate the liquid film by using a water-soluble surfactant to reduce the surface tension of the liquid. However, if an attempt is made to make it possible to remove a film of a liquid using such a surfactant in an absorbent article, the liquid tends to permeate through the leakproof backsheet.

In addition, the nonwoven fabric also includes a nonwoven fabric having a concave portion formed by compression molding by embossing. At the bottom of the compressed concave portion, the fibers are formed into a flattened shape or thermally fused in such a way as to block the space through which liquid penetrates. Consequently, the lower portion of the concave portion has significantly less fiber spacing than any other portion. That is, the lower portion of the concave portion is formed as a high fiber density portion. According to the circumstances, the high density portion has a film surface composed of a fiber resin component, and the space through which the liquid penetrates is compressed in several cases. In such a high density portion, the penetrating liquid stagnates even more easily in the lower portion of the concave portion than in any other portion (non-high density portion) of the nonwoven fabric. Therefore, it is necessary to control the degree of hydrophilicity of the fibers in the high density portion so that liquid reaching the high density portion can quickly penetrate into the interior of the nonwoven fabric. If the degree of hydrophilicity is insufficient, in the part of high density formed the volume of liquid and the feeling of dryness on the surface of the nonwoven fabric is highly suppressed.

{0010}

The nonwoven fabric of the present invention can suppress the liquid volume at the bottom of the concave portion recessed in the thickness direction of the nonwoven fabric, and reduce the liquid film formed between the fibers, achieving a higher level of residual liquid reduction. In addition, according to the method for producing the nonwoven fabric of the present invention, a nonwoven fabric can be obtained that is capable of suppressing the volume of liquid in the lower portion of the concave portion recessed in the thickness direction of the nonwoven fabric and reducing the liquid film formed between the fibers to achieve a reduction in the content residual liquid at a higher level.

{0011}

Specific examples of a preferred embodiment of the nonwoven fabric of the present invention include the nonwoven fabric 5 shown in Figures 1 and 2.

The nonwoven fabric 5 has a plurality of concave portions 6 spaced apart from each other on a side of the first surface 1A that is a side of one surface. The surface on the opposite side of the second surface 1B is formed as a flat surface. The concave portion 6 is a portion of the space in which the fiber layer in the nonwoven fabric 5 is recessed from the side of the first surface 1A towards the side of the second surface 1B. The concave portion 6 (also referred to as the embossed concave portion 6) is formed by compression molding by embossing. The nonwoven fabric 5 has, in the lower portion 7 (hereinafter referred to as the lower portion of the concave portion 7) of this concave portion 6, a high density fiber portion 8 in which the density of the fibers is higher than the density of the fibers in any other portion. In addition, the nonwoven fabric 5 contains an agent for breaking the liquid film in the non-high density portion 9 other than the high density portion 8.

The nonwoven fabric of the present invention may be formed from one layer, as in the nonwoven fabric 5 in FIG. 1, or it may be formed from two or more layers. In addition, the concave portion 6 and the non-high density portion 9 are each not limited to the shape shown in FIG. 1, and may be formed with various shapes. In addition, the nonwoven fabric of the present invention may or may not have a hollow portion. The raw materials for the fibers to be used are not limited in any way, any and varied raw materials can be used appropriately. In addition, in Fig. 1, the nonwoven fabric 5 is shown in a moderately curved state from its fineness and softness. However, the first surface 1A and the second surface 1B, here, are flat in a portion other than the concave portion 6 and have no protruding portion.

The nonwoven fabric of the present invention can be used, for example, in the form of a topsheet of an absorbent article such as a sanitary napkin, baby diaper, or an incontinent adult diaper.

{0012}

Here, the high density portion 8 means a portion in which the fibers are consolidated by pressing the nonwoven in the thickness direction by embossing. As discussed above, the high density portion 8 is a portion in which the fibers are compressed by pressing in a flattened shape or thermally melted in a state in which the distance between the fibers is much smaller than in any other portion. The high density portion has on the surface a film composed of a fiber resin component as appropriate. The surface of the film is a portion in which the resin component is thermally melted by heating during the thin film embossing processing. This surface of the film is formed in several cases in whole or in part in a part of high density depending on the degree of pressure applied during the embossing processing. Such a high density portion 8 can be defined as a region in which the fiber-to-fiber distance is 20 µm or less.

On the other hand, the non-high density portion 9 means all portions other than the high density fiber portion 8 in the lower portion 7 of the concave portion in the fiber structure as a whole in the nonwoven fabric 11. In terms of liquid permeability of the conventional nonwoven fabric or whatever or the like, the distance between fibers in the non-high density portion 9 is generally 50 µm or more and 200 µm or less.

The distance between fibers can be measured in the same way as (in the Method for measuring the distance between fibers) described below.

{0013}

The fiber spacings differ between the non-high density portion 9 and the high density portion 8, and for this reason, the capillary pressure values are different as such. In the high density portion 8, the fiber spacing is shorter and therefore more sensitive to the influence of the degree of hydrophilicity. Part 8 of high density has a very small distance between the fibers, and therefore, if the degree of hydrophilicity in this part is excessively low, it is difficult for liquid to penetrate into the space between the fibers, and liquid cannot be absorbed in this part, and a volume is formed on the surface of part 8 of high density liquids. With respect to this volume of liquid, the high density portion 8 exists in the lower portion 7 of the concave portion, and the liquid entering the surface of the lower portion 7 of the concave portion is formed into a spherical shape. Therefore, the liquid cannot come into contact with the non-high density portion around the high density portion, and the liquid is poorly sucked out, and hence the volume of the liquid is difficult to dissolve. Therefore, in order to prevent the formation of a liquid volume, it is preferable to improve the liquid suction properties through the wetting and spreading properties of the liquid around the high density portion or the capillary force caused by maintaining the hydrophilicity of the high density portion at a high level, in addition to reducing the fiber spacing.

{0014}

The degree of hydrophilicity in the high density portion 8 can be judged by the contact angle of the fibers in the high density portion 8. Accordingly, when the contact angle is smaller, the degree of hydrophilicity is higher, the liquid wets and spreads even more easily, and the capillary force between the fibers works even more easily. In contrast, accordingly, when the contact angle is larger, the degree of hydrophilicity is lower, the liquid does not wet well and spreads poorly, and the capillary force between the fibers decreases. In this case, the liquid takes on a shape close to spherical, and the volume of the liquid is easily formed.

Accordingly, the contact angle of the fibers in the high density portion 8 is preferably smaller than the contact angle of the fibers in the non-high density portion 9. Specifically, from the viewpoint of reducing the volume of liquid for liquid penetration therein in the high density portion 8, in the ratio of contact angle values, the contact angle of the fibers for deionized water is preferably 90 ° or less, more preferably 80 ° or less, even more preferably 70 ° or less, and particularly preferably 65 or less. The contact angle can be measured in the same way as (in the Contact Angle Measurement Method) described below.

{0015}

As discussed above, the liquid film breaker is contained in the fibers of the non-high density portion 9 in the nonwoven fabric 10.

An agent for breaking the liquid film contained in the non-high density portion 9 means an agent that suppresses the formation of a liquid film by breaking a liquid film formed between the fibers or on the surface of the fibers of the nonwoven fabric when the liquid, for example, a discharged liquid such as a liquid high viscosity, including menstrual blood or urine, comes into contact with the nonwoven fabric, and has the effect of breaking the formed liquid film and the effect of suppressing the formation of the liquid film. The first and the last can be referred to as the main impact and the secondary impact, respectively. The destruction of the liquid film is achieved through the action of an agent to destroy the liquid film, which pushes out a part of the liquid film layer, destabilizing this part. By the action of this action of the liquid film breaking agent, the passage of the liquid through the nonwoven fabric is facilitated without being held in the narrow region between the fibers of the nonwoven fabric. That is, the nonwoven fabric becomes excellent in liquid permeability. Thus, even if the fibers that make up the nonwoven fabric become thinner as the distance between the fibers decreases, both texture softness and suppression of residual liquid content are achieved.

{0016}

(Liquid film elimination properties)

The liquid film breaking agent used in the present invention has liquid film breaking properties, and due to such properties, the liquid film breaking agent can develop the liquid film breaking effect when the liquid film breaking agent is applied to the test liquid containing mainly a component of plasma or artificial urine. Artificial urine is prepared by selecting a mixture having a proportion of 1.940% by weight of urea, 0.795% by weight of sodium chloride, 0.110% by weight of magnesium sulfate, 0.062% by weight of calcium chloride, 0.197% by weight of potassium sulfate, 0.010% by weight of red No. 2 (dye), water ( about 96.88 wt%) and a simple polyoxyethylene lauryl ether (about 0.07 wt%), with a surface tension that is adjusted at 53 ± 1 dyne / cm (23 ° C)). The effect of eliminating the liquid film in this document includes, with respect to the structure in which air is retained by the liquid film formed from the test liquid or artificial urine, and as the effect of inhibiting the formation of the liquid film of the structure, and as the effect of eliminating the formed structure of the liquid film, and it can be said that the agent developing at least one such action has properties in accordance with which the action of eliminating the liquid film can be developed.

The test fluid is a liquid component extracted from defibrinated horse blood (manufactured by NIPPON BIO-TEST LABORATORIES INC.). Specifically, if 100 ml of defibrinated horse blood is left to stand at 22 ° C and 65% humidity for 1 hour, the defibrinated horse blood is separated into an upper layer and a lower layer, the upper layer being the test fluid. The upper layer contains mainly the plasma component and the lower layer contains mainly the blood cell component. To collect only the top layer from defibrinated horse blood, which separates into the top layer and the bottom layer, you can use, for example, Transfer Pipet (manufactured by Nippon Micro K.K).

Whether a certain agent has `` liquid film elimination properties '' can be judged by the large or small amount of the structure, namely, the liquid film, when a state of easy structure formation is formed, in which the structure contains air held in it by the liquid film formed from the test liquid or artificial urine to which the agent is applied. That is, a standard sample is obtained by adjusting the temperature of the test fluid or artificial urine to 25 ° C, and then placing 10 g in a bottle with a screw cap (manufactured by Maruemu Corporation, No. 5, outer diameter: 27 mm, total length: 55 mm). In addition, as a sample for measurement, a material prepared by adding 0.01 g of a target agent for measurement adjusted to 25 ° C in advance for the same liquid as a standard sample was obtained. After vigorously shaking twice the standard and the sample to be measured there and back in the vertical direction of the bottle with the screw cap, respectively, the samples are directly placed on the horizontal plane. A liquid layer (bottom layer) without structures and a structure layer (top layer) formed from a plurality of structures formed on the liquid layer are formed inside the screw cap bottle after shaking by shaking the samples. After 10 seconds have elapsed from the end of shaking, the height of the structure layer (the height from the liquid level of the liquid layer to the top surface of the structure layer) is measured for both samples. Then, when the height of the layer of the structures of the sample to be measured reaches 90% or less with respect to the height of the layer of the structures of the standard sample, the target agent for measurement is considered as an agent having an effect of breaking the liquid film.

The liquid film breaker used in the present invention is an agent satisfying these properties (an agent that can develop liquid film breakdown) by a single compound satisfying these properties, a mixture combined with a plurality of individual compounds satisfying these properties, or combination of many connections. That is, the agent for breaking the liquid film means only an agent, a limited material, having the effect of breaking the liquid film as defined. Accordingly, when a third component that does not meet the definition is contained in a compound used in an absorbent article, such an agent is different from a liquid film breaker.

In addition, with respect to the liquid film breaker and the third component, a "separate compound" means a compound in the concept including a compound that has the same compositional formula, but has a different molecular weight due to the difference in the number of repeating units.

As an agent for breaking the liquid film, the material can be appropriately selected from those described in paragraphs {0007} to {0186} in WO 2016/098796, and can be used.

{0017}

The liquid film breaker is applied to the constituent fibers in at least a portion of the nonwoven region and is retained. At least the portion to which the agent is applied as a coating is preferably a portion where a particularly large amount of liquid is received. For example, when the nonwoven fabric of the present invention is applied to the topsheet of an absorbent article such as a sanitary napkin, this region corresponds to the wearer's discharge area where fluid such as menstrual blood is directly received. In addition, with respect to the thickness direction of the nonwoven fabric of the present invention, the liquid film breaker is preferably held at least in the surface on the liquid receiving side. In the topsheet of the above example, the liquid film breaker is held at least at a location on the surface side in contact with the user's skin.

{0018}

In the present invention, the expression "nonwoven material contains or has a liquid film breaking agent" means that the liquid film breaking agent mainly adheres to the surface of the fibers. However, since the liquid film breaker remains present on the surface of the fibers, it is also acceptable for the liquid film breaker to be present within the fibers or be present inside the fiber by being introduced into the fiber. As the method for adhering the liquid film breaker to the fiber surface, any of various commonly used methods can be used without any limitation. Specific examples of the methods include flexographic printing, inkjet printing, gravure printing, screen printing, spraying, brushing, and dipping. Such a treatment can be applied to the fibers before being formed into a web, or the agent can be applied after the fibers are formed into a web by any of a variety of methods. The fibers on the surface of which the liquid film breaker is adhered are dried, for example, using a hot air blower type, at a temperature significantly lower than the melting point of the resin of the fibers (for example, 120 ° C or less). In addition, when the liquid film breaker is adhered to the fibers using the adhesion method, the adhesion can be carried out using the liquid film breaker without dilution, or using a solution containing the liquid film breaker prepared by dissolving the liquid film breaker. in a solvent, if necessary, or with an emulsifying liquid or a dispersing liquid for the liquid film breaker.

In order for the liquid film breaker of the present invention to exhibit the liquid film breakdown effect described below on a nonwoven fabric, the liquid film breaker must be present in a fluid state when the liquid film breaker contacts the bodily fluid. Because of this, the melting point of the liquid film breaking agent of the present invention is 40 ° C or less, and more preferably 35 ° C or less. In addition, the melting point of the liquid film breaking agent of the present invention is preferably -220 ° C or more, and more preferably -180 ° C or more.

{0019}

As described later, the liquid film breaker has a lower surface tension than a conventional hydrophilization treatment agent used for nonwoven fibers or the like. On the fiber surface on which the liquid film breaking agent is adhered, with respect to the contact angle showing the degree of hydrophilicity, its value increases when the adhered amount is large, and can reach 100 ° according to circumstances.

Therefore, in the nonwoven fabric 10, from the viewpoint of keeping the degree of hydrophilicity in the high density portion 8 in the lower portion 7 of the concave portion in a preferable state to prevent the occurrence of liquid volume, the liquid film breaking agent is preferably disposed on the surface of the fiber in the portion 9 not having high density rather than on the fiber surface in the high density portion 8. That is, in the high-density portion 8 that is in the lower portion 7 of the space divided by the concave portion 6 and has fibers that are denser, the content of the liquid film breaker is preferably less than that in the non-high-density portion 9. and more preferably, the content of the liquid film breaker is controlled so that it is not retained in the high density portion 8. The expression "liquid film breaker content is small" means one or both of the states in which the adhered amount of the liquid film breaker in the high density portion 8 is small, or the portion of the fibers with the attached liquid film breaker is small. In addition, the liquid film breaker is particularly preferably disposed only in the non-high density portion 9. In this case, the expression “only in the non-high density part 9” means a state in some concept including the case where a microscopic amount of the liquid film breaking agent is inevitably present in the high density part 8 due to scatter or the like during application. an agent for breaking the liquid film into a part that does not have a high density 9.

The content of the liquid film breaker in the high density portion 8 is preferably 10% by mass or less, more preferably 4% by mass or less, even more preferably 2% by mass or less, and particularly preferably 0% by mass, in terms of its proportion with respect to the content of the liquid film breaker in the non-high density portion 9. Thus, in the nonwoven fabric 10, it becomes difficult for a volume of liquid to be formed in the high density portion 8 at the bottom of the concave portion, and the residual liquid content of the nonwoven fabric 10 can be reduced at a higher level by developing the effect of breaking the liquid film in the portion 9 without having a high density, having the necessary distance between the fibers for liquid penetration.

{0020}

(Method for measuring liquid film breaker content in high density part 8 and non-high density part 9)

The nonwoven fabric is washed with a washing liquid such as hexane, methanol, ethanol and diethyl ether, then the solvent used for washing is dried to release the liquid film breaker. The appropriate column and the corresponding solvent are selected according to the components of the isolated substance, and then each component is fractionated by high performance liquid chromatography, and then MS measurements, NMR spectroscopy, elemental analysis or the like are performed on each fraction to identify the structure of each fraction. In addition, when the compound contained therein contains a polymeric compound, a technique such as gel permeation chromatography (GPC) is simultaneously used to further facilitate the identification of the constituents. Then, a sufficient amount is obtained to study if the substance is a commercial product, or by synthesizing the substance if the substance is not a commercial product.

Then, the compound as a separate material obtained was placed in a solvent of ethanol and diethyl ether at a ratio of 50:50 and quantified by LC-MS (HP1100 LC / MSD, manufactured by Agilent Technologies, Inc.). This operation is repeated while changing the concentration of the compound to create a calibration curve.

Then, 1 g of the high density portion and the non-high density portion were each cut out from the nonwoven fabric. The resulting materials are each placed in a 50:50 ethanol / diethyl ether solvent and washed. Then, a high-density portion and a non-high-density portion are each taken. They were quantified using the remaining extract in accordance with LC-MS discussed above to record the intensity of the peaks obtained from the liquid film breaker. Then, the content of the liquid film breaker in the high density portion and the non-high density portion each is determined from a calibration curve for the liquid film breaker.

{0021}

Preferred embodiments of the liquid film breaking agent contained in the nonwoven fabric of the present invention will be described below.

{0022}

In the agent for breaking the liquid film according to the first embodiment, the spreading coefficient for the liquid having a surface tension of 50 mN / m is 15 mN / m or more. In addition, the compound having the properties of a liquid film breaker in the first embodiment is referred to in some cases as compound C1. In addition, the water solubility of the liquid film breaking agent is preferably 0 g or more and 0.025 g or less.

{0023}

The term "spreading ratio for a liquid having a surface tension of 50 mN / m" for an agent for breaking a film of a liquid means a spreading ratio for a liquid in a case where a discharged liquid such as menstrual blood and urine is expected, as described above. `` Spreading factor '' means a quantity to be determined based on the following expression (1) and from a measured value obtained using the measurement method described below in an ambient range at 25 ° C and 65% relative humidity (RH) ... In addition, the liquid film in expression (1) means the liquid phase ʺ a liquid having a surface tension of 50 mN / mʺ, including both the liquid in the state in which the film is formed between the fibers or on the surface of the fibers, and the liquid in the state before the formation of the film which is also referred to simply as liquid. In addition, the surface tension in expression (1) means the tension at the interface between the liquid film and the liquid film breaking agent, respectively, with the gas phase, and it is different from the tension at the interface between the liquid film breaking agent and the liquid film between the liquid phases. The same rule for such differences applies also to other descriptions in this document.

S = γ _w - γ _o - γ _wo (1)

γ _w : surface tension of the liquid film (s).

γ _o : surface tension of the agent for breaking the liquid film.

γ _wo : tension at the interface of the agent for breaking the liquid film and the liquid film.

{0024}

As is known from expression (1), the spreading coefficient (S) of the agent for breaking the liquid film increases when the surface tension (γ _o ) of the agent for breaking the liquid film decreases and when the tension at the interface (γ _wo ) of the agent for breaking the liquid film decreases and liquid films. When the spreading coefficient is 15 mN / m or more, the liquid film breaking agent has a high mobility, namely, a high diffusion coefficient, on the surface of the liquid film formed in the narrow region between the fibers. From this point of view, the spreading ratio of the liquid film breaking agent is preferably 20 mN / m or more, more preferably 25 mN / m or more, and even more preferably 30 mN / m or more. On the other hand, its upper limit is not limited in any way, but according to expression (1), the surface tension of the liquid that forms the liquid film serves as the upper limit of the spreading coefficient of the agent for breaking the liquid film, thus the upper limit value is 50 mN / m, when a liquid having a surface tension of 50 mN / m is used, the upper limit value is 60 mN / m when a liquid having a surface tension of 60 mN / m is used, and the upper limit value is 70 mN / m when it is used a liquid having a surface tension of 70 mN / m. For this reason, from the viewpoint of using a liquid having a surface tension of 50 mN / m in the present invention, the upper limit is 50 mN / m or less.

{0025}

The term `` water solubility '' of a liquid film breaker means the mass (g) of a liquid film breaker that can dissolve in 100 g of deionized water, and is a value to be measured in a range corresponding to the environment at a temperature of 25 ° C and relative humidity (RH) 65% based on the measurement method described below. When this solubility in water is 0 g or more and 0.025 g or less, the liquid film breaker is poorly soluble and forms an interface with the liquid film, making the above-described diffusion more efficient. From a similar point of view, the water solubility of the liquid film breaker is preferably 0.0025 g or less, more preferably 0.0017 g or less, and even more preferably less than 0.0001 g. In addition, the water solubility is preferably less and it is 0 g or more, and from the point of view of diffusion on a liquid film, the solubility in water is practically controlled at 1.0 x 10 ^-9 g or more. In addition, water solubility is considered to be applicable also to menstrual blood, urine, or the like that contains water as the main component.

{0026}

Surface tension (γ _w ) of a liquid film (liquid having a surface tension of 50 mN / m), surface tension (γ _o ) of an agent for breaking a liquid film, tension at the interface (γ _wo ) of an agent for breaking a liquid film with respect to a film liquid, and the water solubility of the liquid film breaker are measured by the following methods. In addition, this measurement method is common for the high density part 8 and the non-high density part 9.

In addition, when the nonwoven fabric of the measurement target is an item (eg, topsheet) collected in an absorbent article such as a sanitary napkin and a disposable diaper, the nonwoven fabric is sampled as described below and measured. That is, an adhesive or the like that is used to bond between the item to be measured and other items in the absorbent article is loosened by means of cooling means such as spraying a coolant, and then the item to be measured is carefully peeled off and prepared. This removal method is used in measurements associated with the nonwoven fabric of the present invention, such as fiber spacing and fineness measurements, which will be discussed later.

In addition, when the liquid film breaker adhered to the fibers is measured, the fibers to which the liquid film breaker is adhered are first washed with a washing liquid such as hexane, methanol and ethanol, then a solvent (washing solvent containing a film breaker liquid) used for washing is dried to release the liquid film breaker. The weight of the isolated substance is then used in calculating the fraction of the content (OPU) of the agent for breaking the liquid film relative to the weight of the fibers. When the amount of the isolated substance is insufficient to measure the surface tension or the tension at the interface, select the appropriate column and the corresponding solvent according to the components of the isolated substance, and then each component is fractionated by high performance liquid chromatography, and then MS measurement, NMR spectroscopy, elemental analysis is performed. or something similar on each fraction to identify the structure of each fraction. In addition, when the liquid film breaker contains a polymeric compound, a technique such as gel permeation chromatography (GPC) is simultaneously used to further simplify in order to carry out the identification of the constituent. A sufficient amount is then obtained by purchase if the substance is a commercial product, or by synthesis if the substance is not a commercial product, to measure the surface tension or tension at the interface. In particular, regarding the measurement of the surface tension and the tension at the interface, when the liquid film breaker obtained as described above is a solid product, the liquid film breaker is heated to a temperature melting agent for breaking the liquid film plus 5 ° C to cause a phase transition to the liquid, and the measurement is carried out while maintaining these temperature conditions.

{0027}

(Method for measuring surface tension (γ _w ) of a film of liquid (s))

In the ambient range at 25 ° C and 65% relative humidity (RH), measurement can be carried out using a platinum pan using the pan method (Wilhelmy method). As the measuring device for the above case, an automatic surface tension measuring device “CBVP-Z” (trade name, manufactured by Kyowa Interface Science Co., Ltd.) can be used. As the platinum pallet, a pallet having a purity of 99.9% and dimensions 25 mm in width and 10 mm in length is used.

In the following measurement related to the agent for breaking the film of the liquid, as the liquid having a surface tension of 50 mN / mʺ described above, a solution is used, and the solution is controlled at 50 ± 1 mN / m by adding polyoxyethylene sorbitan monolaurate ( for example, the trade name "Leodol Super TW-L120," is manufactured by Kao Corporation), which is a non-ionic surfactant, using the measurement method described above.

{0028}

(Method for measuring the surface tension (γ _o ) of an agent for breaking a liquid film)

The measurement can be carried out using the same device using the pallet method, in the same way as for measuring the surface tension (γ _w ) of a liquid film, in the range corresponding to the environment, at a temperature of 25 ° C and a relative humidity (RH) of 65% ... In this measurement, as discussed above, when the obtained liquid film breaker is solid, the liquid film breaker is heated to the melting point of the liquid film breaker plus 5 ° C to cause a phase transition to the liquid, and measurements are taken while maintaining these temperature conditions.

{0029}

(Method for measuring the tension at the interface (γ _wo ) of an agent for breaking a liquid film and a liquid film)

In the ambient range at 25 ° C and 65% relative humidity (RH), measurement can be performed using the hanging drop method. As a measuring device, in the above case, you can use an automatic device for measuring viscoelasticity at the interface (trade name ʺTHE TRACKER, ʺ manufactured by TECLIS-IT CONCEPT; or trade name DSA25S, manufactured by KRUSS). In the hanging drop method, the adsorption of a nonionic surfactant contained in a liquid having a surface tension of 50 mN / m begins simultaneously with the formation of a drop, the tension at the interface decreases with time. For this reason, the tension at the interface is recorded when the drop is formed (at 0 seconds). In addition, in this measurement, as discussed above, when the obtained liquid film breaker is solid, the liquid film breaker is heated to the melting point of the liquid film breaker plus 5 ° C to cause a phase transition to the liquid, and the measurement is performed while maintaining these temperature conditions.

In addition, when measuring the tension at the interface, when the density difference between the agent for breaking the liquid film and the liquid having the surface tension of 50 mN / m is very small, when the viscosity is very high or when the tension value at the interface is equal to or less, than the hanging drop limit, in some cases, the interface tension measurement by the hanging drop method becomes difficult. In the above case, the measurement can be carried out using the rotating drop method in the range corresponding to the environment at a temperature of 25 ° C and a relative humidity (RH) of 65%. As the measuring device in the above case, a rotating drop interface tension measuring device (trade name “SITE100,” manufactured by KURUSS) can be used. In addition, also with respect to the measurement, the tension at the interface is recorded when the droplet shape is stabilized, and when the obtained liquid film breaker is solid, the liquid film breaker is heated to the melting point of the liquid film breaker plus 5 ° C to cause phase transition into a liquid, and the measurement is carried out while maintaining these temperature conditions.

In addition, when the tension at the interface can be measured with both measuring devices, the lower tension at the interface is used as the measurement results.

{0030}

(Method for measuring the water solubility of a liquid film breaker)

In the range corresponding to the environment, at a temperature of 25 ° C and a relative humidity (RH) of 65%, the obtained liquid film breaker gradually dissolves in it, while 100 g of deionized water is stirred with a stirrer, and the dissolved amount at a time point, when there is no dissolution as a result (when suspension, precipitation, precipitation or turbidity is observed), is taken as the solubility in water. Specifically, the agent is added in portions of 0.0001 g and measurement is performed. As a result, for a sample in which dissolution of an agent in an amount reaching 0.0001 g is not observed, the solubility in water is taken as ʺ less than 0.0001 g ʺ, and for a sample in which dissolution of an agent in an amount of 0.0001 d, and dissolution of the agent in the amount of 0.0002 g is not observed, the solubility in water is taken as 0.0001 gʺ. In addition, when the agent for breaking the liquid film is a surfactant, the term "dissolution" means both monodisperse dissolution and dissolution as a micellar dispersion, and the dissolved amount at the time of observation of the suspension, precipitation, precipitation or turbidity is taken as the solubility in water.

{0031}

When the liquid film breaker in the present embodiment has a spreading coefficient and a water solubility as above, it can spread without dissolution on the surface of the liquid film and can push the liquid film layer away from the center near the liquid film. Thus, the liquid film is destabilized and destroyed.

{0032}

The effect of the agent for breaking the liquid film in the nonwoven fabric in the embodiment of the present document is specifically described with reference to Figures 3 and 4.

As shown in Fig. 3, a discharged liquid such as a high viscosity liquid including menstrual blood and urine easily forms a liquid film 2 in a narrow region between the fibers. To combat this, the liquid film breaker destabilizes and breaks the liquid film, as described below, and inhibits the formation of the liquid film, causing the interior of the nonwoven fabric to drain. First, as shown in FIGS. 4 (A1) and 4 (B1), the liquid film breaking agent 3 contained in the fibers 1 of the nonwoven fabric is applied to the surface of the liquid film 2 while maintaining the interface with the liquid film 2. Then, as shown in FIGS. 4 (A2) and 4 (B2), the liquid film breaking agent 3 pushes back a part of the liquid film 2, entering the liquid film 2 in the thickness direction, and as shown in FIGS. 4 (A3) and 4 ( B3), the agent for breaking the liquid film 3 gradually transforms the liquid film 2 into a non-uniform and thin film. As a result, as shown in Figures 4 (A4) and 4 (B4), the liquid film 2 is perforated and explosively destroyed. A broken film of liquid, such as menstrual blood, is formed into a drop of liquid, easily passing through the space between the fibers of the nonwoven fabric, and the amount of residual liquid is reduced. In addition, the effect of the liquid film breaker on the liquid film is demonstrated in a similar manner, not only for the liquid film between the fibers, but also for the liquid film enveloping the surface of the fibers. That is, the agent for breaking the liquid film can move into the liquid film, enveloping the surface of the fibers, and it pushes a part of the liquid film, breaking the liquid film. In addition, in the case of a liquid film enveloping the fiber surface, the liquid film breaker can break the liquid film also by hydrophobic action, without even moving from the position where the agent adheres to the fibers, and can inhibit the formation of the liquid film.

{0033}

Thus, the liquid film disrupting agent of the present invention causes liquid to be removed from the interior of the nonwoven fabric not by modifying the properties of the liquid, such as by reducing the surface tension, but by breaking the liquid film itself formed between the fibers or on the surface of the fibers, thereby displacing liquid film and inhibiting liquid film formation. Thus, the amount of residual liquid in the nonwoven fabric can be reduced. In addition, if such a nonwoven material is collected in an absorbent article as a topsheet, liquid retention between the fibers is suppressed and a path is provided for liquid to penetrate into the absorbent body. Thus, liquid permeability is improved, the flow of liquid on the surface of the sheet and the rate of absorption of the liquid is improved. In particular, the rate of absorption of liquid that is easily held between fibers, such as high viscosity menstrual blood, can be improved. As a result, it is possible to form a comfortable absorbent article of high reliability in which coloration of the topsheet such as redness is imperceptible and sufficient absorbency is expected.

{0034}

Further, in an embodiment, the surface tension of the liquid film breaking agent for the liquid having a surface tension of 50 mN / m is preferably 20 mN / m or less. This means that the “surface tension (γ _wo ) of the agent for breaking the liquid film and the liquid film”, which is one of the parameters for determining the value of the spreading coefficient (S) in expression (1) above, is preferably 20 mN / m or less. ... The spreading coefficient of the liquid film breaking agent is improved by suppressing the tension at the interface (γ _wo ) of the liquid film breaking agent and the liquid film itself, and the liquid film breaking agent easily moves from the surface of the fibers in the region near the center of the liquid film, and the effect discussed above becomes clearer. From this point of view, the tension at the interface with a liquid having a surface tension of 50 mN / mʺ and an agent for breaking the liquid film is more preferably 17 mN / m or less, even more preferably 13 mN / m or less, and particularly preferably 10 mN / m or less, particularly preferably 9 mN / m or less, and even more preferably 1 mN / m or less. On the other hand, its lower limit is not in any way limited, and it should only be greater than 0 mN / m in terms of insolubility in the liquid film. In addition, if the tension at the interface is 0 mN / m, that is, if the agent for breaking the liquid film is soluble, the interface between the liquid film and the agent for breaking the liquid film cannot be formed, and for this reason, expression (1 ) does not take place, and the agent does not spread out.

As is known from this expression, the numerical value of the spreading coefficient varies depending on the surface tension of the target fluid. For example, when the surface tension of the target liquid is 72 mN / m, the surface tension of the liquid film breaker is 21 mN / m; and when the tension at its interface is 0.2 mN / m, the spreading coefficient becomes 50.8 mN / m.

In addition, when the surface tension of the target liquid is 30 mN / m, the surface tension of the liquid film breaking agent is 21 mN / m; and when its tension at the interface is 0.2 mN / m, the spreading coefficient becomes 8.8 mN / m.

In any case, for an agent with a higher spreading coefficient, the effect of destruction of the liquid film getting bigger.

In the present description, the numerical value of the surface tension is 50 mN / m. However, even if the surface tension is different, there is no change in the ratio of the numerical value of the spreading coefficient for different substances. For this reason, even if the surface tension of the bodily fluid is to be changed depending on the physical condition on that day or the like, the agent for which the spreading coefficient is larger shows the better effect of breaking the liquid film.

{0035}

In addition, in the present embodiment, the surface tension of the liquid film breaking agent is preferably 32 mN / m or less, more preferably 30 mN / m or less, even more preferably 25 mN / m or less, and particularly preferably 22 mN / m or less. In addition, the surface tension is preferably less and its lower limit is not particularly limited. From the point of view of the long-term action of the agent for breaking the liquid film, the surface tension is practically 1 mN / m or more.

{0036}

Next, an agent for breaking the liquid film according to the second embodiment will be described.

In the agent for breaking a liquid film according to the second embodiment, the spreading coefficient for a liquid having a surface tension of 50 mN / m is greater than 0 mN / m, namely, has a positive value, and the tension at the interface for a liquid having a surface tension 50 mN / m is 20 mN / m or less. In addition, the compound having the properties of the liquid film breaker of the second embodiment is referred to as compound C2 in several cases. In addition, the water solubility of the liquid film breaking agent is preferably 0 g or more and 0.025 g or less.

The nonwoven fabric according to the second embodiment contains an agent for breaking the liquid film. Having its tension at the interface with a liquid having a surface tension of 50 mN / mʺ of 20 mN / m or less, as discussed above, means that the diffusion of the liquid film breaker on the liquid film is improved. Thus, even when the spreading ratio is relatively small, such as in the case where the spreading ratio for a liquid having a surface tension of 50 mN / m 15 is less than 15 mN / m, the diffusion coefficient is high, and for this reason, a large amount of agent for breaking the liquid film is dispersed in the liquid film from the surface of the fibers, and the same effect as in the case of the first embodiment can be obtained by pushing the liquid film out in a plurality of positions.

In addition, the "spreading coefficient for a liquid having a surface tension of 50 mN / m", "water solubility" and "tension at the interface with a liquid having a surface tension of 50 mN / m" with respect to the agent for breaking the liquid film are determined in the same way as defined for the first embodiment, and the measurement methods are the same.

{0037}

In the present embodiment, from the point of view of further effective demonstration of the effect of the agent for breaking the liquid film, the "tension at the interface with the liquid having a surface tension of 50 mN / m" is preferably 17 mN / m or less, more preferably 13 mN / m or less, even more preferably 10 mN / m or less, even more preferably 9 mN / m or less, and particularly preferably 1 mN / m or less. The lower limit is not in any limited way similar to the first embodiment, and from the point of view of insolubility in the liquid film (liquid having a surface tension of 50 mN / m), the tension at the interface is practically set at a value greater than 0 mN / m ...

In addition, from the point of view of further effective demonstration of the effect of the agent for breaking a liquid film, the spreading ratio for a liquid having a surface tension of 50 mN / mʺ is preferably 9 mN / m or more, more preferably 10 mN / m or more, and still more preferably 15 mN / m or more. Its upper limit is not particularly limited, but from the viewpoint that the surface tension of the liquid that forms the liquid film serves as the upper limit of Expression (1), the spreading ratio is substantially 50 mN / m or less.

In addition, more preferable ranges of surface tension and water solubility of the liquid film breaker are the same as those of the first embodiment.

{0038}

In addition to the liquid film breaker described above, the nonwoven fabric of the first embodiment and the nonwoven fabric of the second embodiment, each preferably further comprises an anionic surfactant of the phosphoric acid ester type. Thus, the hydrophilicity on the fiber surface is improved, and the wettability is improved, with an increase in the contact area between the liquid film and the liquid film breaker. In addition, since blood and urine contain a surfactant containing a phosphoric acid group that is formed in a living body when a surfactant containing a phosphoric acid group is used together with a liquid film breaker, the surfactant shows compatibility close to affinity for phospholipid contained in blood and urine. In this case, the agent for breaking the liquid film easily moves into the liquid film, and additional destruction of the liquid film is caused. The ratio of the liquid film breaker to the phosphoric acid ester type anionic surfactant is preferably (1: 1) to (19: 1), more preferably (2: 1) to (15: 1), and even more preferably, from (3: 1) to (10: 1) in terms of weight ratio (liquid film breaker: anionic surfactant of the phosphoric acid ester type). In particular, the content ratio is preferably from (5: 1) to (19: 1), more preferably from (8: 1) to (16: 1), and even more preferably from (11: 1) to (13 : 1) in terms of mass relation.

{0039}

An anionic surfactant of the phosphoric acid ester type can be used without any limitation. Specific examples thereof include a phosphoric acid alkyl ester, a phosphoric dialkyl ester, and a phosphoric acid alkyl ester. First of all, a phosphoric acid alkyl ester is preferable from the viewpoint of the function of improving the affinity for the liquid film and ensuring the workability of the nonwoven fabric.

As the phosphoric acid alkyl ether ester, various kinds thereof can be used without any limitation. Specific examples thereof include an alkyl phosphoric acid ester having a saturated carbon chain such as polyoxyalkylene stearyl phosphoric acid ester, polyoxyalkylene myristyl phosphoric acid ester, polyoxyalkylene lauryl ester phosphoric acid and an ester of a simple polyoxyalkylene palmityl ester of phosphoric acid; an alkyl phosphoric acid ester containing an unsaturated carbon chain such as a polyoxyalkylene oleyl phosphoric acid ester and a polyoxyalkylene palmitoleyl phosphoric acid ester; and a phosphoric acid alkyl ester containing a side chain in each of its carbon chains. Ester of simple alkyl ester of phosphoric acid, more preferably, is a fully or partially neutralized ester salt of mono - or simple dipolyoxyalkylene alkyl ester of phosphoric acid, containing a carbon chain of 16-18 carbon atoms. In addition, specific examples of the polyoxyalkylene include polyoxyethylene, polyoxypropylene, polyoxybutylene, and a material in which its constituent monomers are copolymerized. In addition, specific examples of the phosphoric acid alkyl ester salt include a salt of an alkali metal such as sodium and potassium, ammonium and various amines. As the phosphoric acid alkyl ether ester, one kind can be used by itself, or two or more kinds can be mixed and used.

Specific examples of the phosphoric acid alkyl ester include a saturated carbon chain phosphoric acid alkyl ester such as phosphoric stearyl ester, phosphoric acid myristyl ester, phosphoric acid lauryl ester and phosphoric acid palmityl ester; an alkyl phosphoric acid ester containing an unsaturated carbon chain such as a phosphoric oleyl ester and a phosphoric palmitoleyl ester; and an alkyl phosphoric acid ester containing a side chain in each of its carbon chain. More preferably, the phosphoric acid alkyl ester is a fully or partially neutralized salt of a phosphoric acid monoalkyl ester or a phosphoric dialkyl ester having a carbon chain of 16-18 atoms. In addition, specific examples of the phosphoric acid alkyl ester salt include a salt with an alkali metal such as sodium and potassium with ammonium and various amines. As the phosphoric acid alkyl ester, one kind can be used by itself, or two or more kinds can be mixed and used.

{0040}

In the first embodiment and in the second embodiment, the contact angle of the constituent fibers in the non-high density portion 9 of the nonwoven fabric containing a liquid film breaker or a liquid film breaker and an anionic surfactant of the phosphoric acid ester type as described above, is preferably 100 degrees or less, more preferably 90 degrees or less, and even more preferably 85 degrees or less. Thus, the surface of the fibers becomes hydrophilic, the wetted area is increased, and the liquid film breaker is easily transferred to the liquid film.

{0041}

(Contact angle measurement method)

The measurement of the contact angle described above is carried out using the method described below.

First, in the case of the non-high density portion 9, fibers are taken from a predetermined location in the nonwoven fabric, and the water contact angle for the fibers is measured. As a measuring device, an Automatic Contact Angle Meter MCA-J manufactured by Kyowa Interface Science Co., Ltd. is used. Distilled water is used to measure the contact angle. The measurement is carried out in an environment at a temperature of 25 ° C and at a relative humidity (RH) of 65%. The amount of fluid to be jetted from the water droplet jetting unit according to the inkjet printing system (CTC-25 pulse injector having an inkjet unit opening of 25 μm, manufactured by Cluster Technology Co., Ltd.) is set at 15 picoliters. and drops of water are added drop by drop directly onto the fibers. The dropwise addition aspect is recorded on a high speed recorder connected to a horizontally mounted camera. From the point of view of performing image analysis and subsequent image analysis, the recording device is preferably a personal computer to which the high-speed recording device is connected. With this measurement, the image is captured every 17 msec. On the recorded image, the image is analyzed, on the first image in which the water drop is deposited on the fibers taken from the nonwoven fabric, by means of the auxiliary software FAMAS (software version: 2.6.2, analysis method: fixed drop method, analysis method: method θ / 2, image processing algorithm: no reflection, image processing mode: frame, threshold level: 200, and curvature correction: none) to calculate the angle formed between the fibers and the surface of a water droplet in contact with air, and the calculated value is taken as contact angle. Fibers taken from the nonwoven are cut into 1 mm fibers, and the fibers are placed on a sample stand of the contact angle meter, which must be kept horizontally. And then the fibers are subjected to contact angle measurements at two different positions on the same fiber. Contact angles (N = 5) are measured to one decimal place, and the value (rounded to two decimal places) obtained by averaging the measured values in ten places in total is defined as the contact angle.

Further, in the case of the high density portion 8, the high density portion 8 as a whole is sampled and measured instead of measuring the contact angle by sampling fibers in the non-high density portion 9. Contact angles are measured at three different locations for one high density part 8, and the mean (rounded to two decimal places) is defined as the contact angle. Operations other than this operation are the same as in the case of the non-high density part 9.

{0042}

Next, specific examples of the liquid film breaking agents in the first embodiment and the second embodiment will be described. They are within the specific range of numerical values discussed above so that they have properties of insolubility in water or low solubility in water, and demonstrate the effect of breaking the liquid film. In contrast, a surfactant or the like for use as a conventional fiber treating agent is basically a water-soluble agent that is substantially all water-soluble and used, rather than the liquid film breaker of the present invention.

{0043}

As the agent for breaking the liquid film in the first embodiment and in the second embodiment, a compound having a weight average molecular weight of 500 or more is preferable. The weighted average molecular weight strongly affects the viscosity of the liquid film breaker. The liquid film breaker almost does not run off when the liquid passes through the space between the fibers due to the high viscosity being maintained, and the long-term effect of breaking the liquid film in the nonwoven fabric can be maintained. In terms of adjusting the viscosity at the level at which the effect of breaking the liquid film is is sufficiently long-term, the weight average molecular weight of the liquid film breaking agent is more preferably 1000 or more, even more preferably 1500 or more, and particularly preferably 2000 or more. On the other hand, from the viewpoint of adjusting the viscosity at a level at which migration of the liquid film breaker from the fibers containing the liquid film breaker disposed thereon takes place into the liquid film, namely diffusion, its weight average molecular weight is preferably 50,000 or less, more preferably 20,000 or less, and even more preferably 10,000 or less. The measurement of the weight average molecular weight was carried out using a "CCPD" Gel Permeation Chromatography (GPC) chromatograph (trade name, manufactured by TOSOH CORPORATION). The measurement conditions are described below. In addition, the calculation of the equivalent molecular weight is carried out using polystyrene.

Separation column: GMHHR-H + GMHHR-H (cationic)

Eluent: L FAMIN DM20 / CHCl3

Solvent flow rate: 1.0ml / min

Separation column temperature: 40 ° C

{0044}

In addition, as the agent for breaking the liquid film according to the first embodiment, as discussed below, a compound having at least one kind of structure selected from the group consisting of the following structures X, X-Y, and Y-X-Y is preferable.

Structure X denotes a siloxane chain having a structure in which any of the main structures> C (A) - (C denotes a carbon atom, in addition, <,> and -, each denotes a chemical bond, hereinafter referred to the same), -C (A)₂-, -C (A) (B) -,> C (A) -C (R^one) <,> C (R^one) -, -C (R^one) (R²) -, -C (R^one)₂-,> C <, -Si (R^one)₂O- and -Si (R^one) (R²) O- are repeated, or two or more of their types are combined; or a mixed chain of them. Structure X contains at the end of the structure X, a hydrogen atom or at least one kind of group selected from the group consisting of -C (A)₃, -C (A)₂B, -C (A) (B)₂, -C (A)₂-C (R^one)₃, -C (R^one)₂A, -C (R^one)₃, -OSi (R^one)₃, -OSi (R^one)₂(R²), -Si (R^one)₃ and -Si (R^one)₂(R²).

The above R^one and R², each independently represents a different substituent such as a hydrogen atom, an alkyl group (the number of carbon atoms is preferably from 1 to 20, for example, a methyl group, an ethyl group or a propyl group is preferred), an alkoxy group (the number of carbon atoms is preferably from 1 to 20, for example, a methoxy group or an ethoxy group is preferred), an aryl group (the number of carbon atoms is preferably 6 to 20, for example, a phenyl group is preferred) and a halogen atom (for example, a fluorine atom is preferred). A and B each independently represent a substituent containing an oxygen atom or a nitrogen atom such as a hydroxy group, a carboxylic acid group, an amino group, an amide group, an imino group, and a phenol group. When there is a set R^one, R², A and B, for each of them, X in the structure can be the same or different. Also, continuous communication between C (carbon atoms) or between Si is usually a single bond, but may include a double bond or a triple bond, and a bond between C or between Si may include a linking group such as an ether group (-O-), an amide group ( -CONR^A-: R^A represents a hydrogen atom or a monovalent group), an ester group (-COO-), a carbonyl group (-CO-) or a carbonate group (-OCOO-). The number of bonds of one C and one Si to any other C or Si is 1 to 4, and the long chain silicone chain (siloxane chain) or mixed chain can be branched or can have a radial structure.

Y represents a hydrophilic group having hydrophilicity, the group contains an atom selected from a hydrogen atom, a carbon atom, an oxygen atom, a nitrogen atom, a phosphorus atom, or a sulfur atom. Specific examples thereof include a hydrophilic group per se such as a hydroxy group, a carboxylic acid group, an amino group, an amide group, an imino group, a phenol group, a polyoxyalkylene group (the number of carbon atoms of the oxyalkylene group is preferably 1 to 4, for example, polyoxyethylene ( POE) group, polyoxypropylene (POP) group are preferred), sulfonic acid group, sulfate group, phosphoric acid group, sulfobetaine group, carbobetaine group, phosphobetaine group (betaine group means a betaine residue group formed by removing one hydrogen atom from each betaine compound ) and a quaternary ammonium group; or a hydrophilic group formed from a combination thereof. In addition, their specific examples also include a group and a functional group listed in M ¹ , as discussed below. In addition, when a plurality of Ys exist, these groups may be the same or different.

In structures XY and YXY, Y binds to X or to a group at the X-terminal. When Y bonds to a group at the X-terminal, for example, a group at the X-terminal bonds to Y after removal of hydrogen atoms, and the like, in an amount identical to the number of bonds with Y.

In this structure, the above-discussed spreading coefficient, water solubility and interface tension can be made satisfactory by selecting the hydrophilic groups Y, A and B from the specifically described groups. Thus, the target effect of the destruction of the liquid film develops.

{0045}

In the above-described liquid film breaker, a compound in which structure X contains a siloxane structure is preferable. In addition, as specific examples of the above-described structures of X, XY, and YXY in a liquid film breaker, a compound containing a siloxane chain in which the structures represented by any of the following Formulas (1) to (11) are randomly combined, is preferred. In addition, from the viewpoint of the effect of breaking the liquid film, it is preferable that the compound has a weight average molecular weight in the range discussed above.

{0046}

{0047}

In Formulas (1) to (11), M ¹ , L ¹ , R ²¹ and R ²² denote the following monovalent or polyvalent (divalent or higher valence) group. R ²³ and R ²⁴ represent the following monovalent or polyvalent (divalent or higher valence) group or single bond.

M ¹ represents a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, a group containing a polyoxyalkylene group in combination therewith, an erythritol group, a xylitol group, a sorbitol group, a hydrophilic group having a plurality of hydroxy groups such as a glycerol group or an ethylene glycol group (hydrophilic formed by removing one hydrogen atom from the above-described compound having a plurality of hydroxy groups such as erythritol), a hydroxy group, a carboxylic acid group, a mercapto group, an alkoxy group (the number of carbon atoms is preferably 1-20, for example, a methoxy group is preferred ), amino group, amide group, imino group, phenol group, sulfonic acid group, quaternary ammonium group, sulfobetaine group, hydroxysulfobetaine group, phosphobetaine group, imidazolium betaine group, carbobetaine group, epoxy group, carbinol group, (meth) acryl th group or functional group in combination with them. In addition, when M ¹ is a multivalent group, M ¹ is a group formed by further removing one or more hydrogen atoms from each of the groups or from a functional group as discussed above.

L ¹ is a linking group from an ether group, an amino group (the amino group used as L ¹ is represented by> NR ^C (R ^C is a hydrogen atom or a monovalent group)), an amide group, an ester group, a carbonyl group, or carbonate group.

R ²¹ , R ²² , R ²³ and R ²⁴ each independently represent an alkyl group (the number of carbon atoms is preferably from 1 to 20, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, a hexyl a group, a heptyl group, a 2-ethylhexyl group, a nonyl group or a decyl group is preferred), an alkoxy group (the number of carbon atoms is preferably from 1 to 20, for example, a methoxy group or an ethoxy group is preferred), an aryl group (the number of carbon atoms is preferably is from 6 to 20, for example, a phenyl group is preferred), a fluoroalkyl group, an aralkyl group, a hydrocarbon group in combination with them, or a halogen atom (for example, a fluorine atom is preferred). In addition, when R ²² and R ²³ are a multivalent group, R ²² and R ²³ are a multivalent hydrocarbon group formed by further removing one or more hydrogen or fluorine atoms from the above-described hydrocarbon group.

In addition, when R ²² or R ²³ is bonded to M ¹ , specific examples of the group used as R ²² or R ²³ include, in addition to each of the groups, a hydrocarbon group or a halogen atom described above, an imino group used in quality R ³² .

First of all, the agent for breaking the liquid film is preferably a compound having a structure represented by any of Formulas (1), (2), (5) and (10) as X, and having a structure represented by any of the above formulas otherwise, than these formulas, as a group formed at the X terminal or formed at the X and Y terminal. In addition, the agent for breaking the liquid film is preferably a compound containing a siloxane chain having at least one structure represented by any of the described above Formulas (2) (4), (5), (6), (8) and (9), as a group formed from X or formed from the endings X and Y.

{0048}

Specific examples of the above-described compound include an organically modified silicone (polysiloxane) of a silicone-based surfactant. Specific examples of the organically modified silicone modified with a reactive organic group include amino modified silicone, epoxy modified silicone, carboxy modified silicone, diol modified silicone, carbinol modified silicone, (meth) acrylic modified silicone, mercapto -modified silicone and phenol-modified silicone. In addition, specific examples of organically modified silicone modified with a chemically inactive organic group include polyether modified silicone (including polyoxyalkylene modified silicone), methyl styryl modified silicone, long chain alkyl modified silicone, higher fatty acid ester modified silicone, higher alkoxy modified silicone, higher fatty acid modified silicone and fluorine modified silicone. The spreading coefficient at which the above-described effect of destruction of the liquid film is carried out, can be obtained by appropriately changing the molecular weight of the silicone chain, the ratio of modification, the amount of added moles of the modifying group, or the like, for example, according to the types of organically modified silicone. The term "long chain" herein means a material in which the number of carbon atoms is 12 or more, and preferably from 12 to 20. In addition, the term "higher" means a material in which the number of carbon atoms is 6 or more, and preferably from 6 to twenty.

Primarily, modified silicone having a structure in which the agent for breaking the liquid film is a modified silicone, contains at least one oxygen atom in a modifying group such as polyoxyalkylene modified silicone and epoxy modified silicone, carbinol modified silicone and diol -modified silicone are preferred, and polyoxyalkylene-modified silicone is particularly preferred. The polyoxyalkylene-modified silicone penetrates poorly into fibers and is easy to adhere to, since the polyoxyalkylene-modified silicone contains a polysiloxane chain. In addition, with respect to the polyoxyalkylene-modified silicone, the affinity for water is improved, and the tension at the interface is low due to the presence of the hydrophilic polyoxyalkylene chain, and therefore, motion on the surface of the liquid film is easily caused, as discussed above, and such a case is preferable. In addition, even if a heat fusion treatment such as embossing is applied, the polyoxyalkylene-modified silicone easily remains on the surface of the fibers in this part, and the effect of breaking the liquid film almost does not decrease. Impact of liquid film destruction is sufficiently developed, in particular in the embossed part in which liquid can easily accumulate, and therefore such a case is preferable.

{0049}

Specific examples of the polyoxyalkylene-modified silicone include compounds represented by the following Formulas [I] to [IV]. In addition, the polyoxyalkylene-modified silicone preferably has a weight average molecular weight in the above range in terms of the effect of breaking the liquid film.

{0050}

{0051}

{0052}

{0053}

{0054}

In the Formulas, R ³¹ represents an alkyl group (the number of carbon atoms is preferably from 1 to 20, for example, 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-ethylhexyl group, nonyl group or decyl group is preferred). R ³² is a single bond or an alkylene group (the number of carbon atoms is preferably 1 to 20, for example, a methylene group, an ethylene group, a propylene group or a butylene group is preferred), and is preferably an alkylene group. The plurality of R ³¹ and the plurality of R ³² may each be the same or different. M ¹¹ represents a group containing a polyoxyalkylene group, and a polyoxyalkylene group is preferred. Specific examples of the above-described polyoxyalkylene groups include a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, or a material in which their constituent monomers are copolymerized. Then, m and n are each independently an integer of 1 or more. In addition, the designation of these repeating units is defined separately in each of the formulas [I] to [IV], and they do not always represent the same whole numbers, and they may be different.

{0055}

In addition, the polyoxyalkylene-modified silicone may contain any modifying group for the polyoxyethylene modification and the polyoxypropylene modification, or both. In addition, the modified silicone preferably contains a methyl group in R³¹ as the alkyl group of the silicone chain to obtain water insolubility and low interfacial tension. The material containing this modifying group or silicone chain is not in any way limited, but the materials described in paragraphs {0006} and {0012} in JP-A-2002-161474 are illustrative of them. In addition, specific examples thereof include polyoxyethylene (POE) -polyoxypropylene (POP) -modified silicone, polyoxyethylene (POE) -modified silicone, and polyoxypropylene (POP) -modified silicone. Specific examples of POE-modified silicone include POE (3) -modified dimethyl silicone to which 3 moles of POE are added. Specific examples of POP-modified silicone include POP (10) -modified dimethylsilicone, POP (12) -modified dimethylsilicone, and POP (24) -modified dimethylsilicone, to which 10 moles of POP, 12 moles of POP and 24 moles of POP are added, respectively.

{0056}

The spreading coefficient and water solubility in the above first embodiment can be adjusted within predetermined ranges, for example, in polyoxyalkylene-modified silicone, by adding the number of moles of polyoxyalkylene groups (the number of linking oxyalkylene groups that form a polyoxyalkylene group, relative to 1 mole of polyoxyalkylene -modified silicone) following the modification ratio or the like. In this liquid film breaker, the surface tension and the tension at the interface can be adjusted within predetermined ranges in the same manner, respectively.

From the above point of view, the amount of added moles of polyoxyalkylene groups is preferably 1 or more. When the amount is less than 1, the tension at the interface increases too much for the above-described effect of breaking the liquid film, causing the spreading coefficient to decrease, and for this reason, the effect of breaking the liquid film is weakened. From this point of view, the amount of added moles is more preferably 3 or more, and even more preferably 5 or more. On the other hand, if the amount of added moles is too large, the liquid film breaker becomes hydrophilic and the water solubility increases. From this point of view, the amount of added moles is preferably 30 or less, more preferably 20 or less, and even more preferably 10 or less.

If the modification ratio of the modified silicone is too small, the hydrophilicity deteriorates, and for this reason, the modification ratio is preferably 5% or more, more preferably 10% or more, and even more preferably 20% or more. In addition, if the modification ratio is too large, the liquid film breaker dissolves in water, and for this reason, the modification ratio is preferably 95% or less, more preferably 70% or less, and even more preferably 40% or less. ... In addition, the modification ratio of the modified silicone means the proportion of the number of repeating units of the binding portion of the modified siloxane relative to the total repeating units of the binding portion of the siloxane in one molecule of the modified silicone. For example, the modification ratio is expressed by the expression: (n / m + n) × 100% in Formulas [I] and [IV], the expression: (2 / m) × 100% in Formula [II] and the expression: (1 / m) × 100% in Formula [III].

In addition, the spreading ratio and water solubility discussed above can each be set in a predetermined range in addition to the material described above, for example, in polyoxyalkylene modified silicone, by using together a water-soluble polyoxyethylene group and a water-insoluble polyoxypropylene group, and a water-insoluble a polyoxybutylene group as a modifying group by changing the molecular weight of the water-insoluble silicone chain; introducing therein an amino group, an epoxy group, a carboxy group, a hydroxy group, a carbinol group or the like, in addition to the polyoxyalkylene modification, as a modifying group; or something similar.

{0057}

The polyalkylene-modified silicone used as an agent for breaking the liquid film is preferably contained at 0.02% by mass or more and 8.0% by mass or less in terms of the proportion of content (Oil Per Unit) with respect to the mass of the fibers. The proportion (OPU) of the polyalkylene-modified silicone is more preferably 5% by mass or less, even more preferably 1% by mass or less, and especially preferably 0.4% by mass or less. Thus, the topsheet 1 has a preferred texture. In addition, from the point of view of effective demonstration of the effect of destruction of the liquid film polyalkylene-modified silicone, the content ratio (OPU) is more preferably 0.04 mass% or more, and even more preferably 0.1 mass% or more.

{0058}

As the agent for breaking the liquid film of the second embodiment, as discussed later, a compound containing at least one kind of structure selected from the group consisting of the following structures Z, Z-Y and Y-Z-Y is preferable.

Structure Z denotes a hydrocarbon chain having a structure in which any basic structures are repeated> C (A) - (C: carbon atom), -C (A)₂-, -C (A) (B) -,> C (A) -C (R³) <,> C (R³) -, -C (R³) (R^four) -, -C (R³)₂- and> C <, or combine two or more of them. Structure Z has, at one of its ends, a hydrogen atom or at least one kind of group selected from the group consisting of -C (A)₃, -C (A)₂B, -C (A) (B)₂, -C (A)₂-C (R³)₃, -C (R³)₂A -C (R³)₃...

The above-described R ³ and R ⁴ each independently represent different kinds of substituents such as hydrogen atom, alkyl group (the number of carbon atoms is preferably 1 to 20, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group , pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, nonyl group or decyl group is preferred), alkoxy group (the number of carbon atoms is preferably from 1 to 20, for example, methoxy group or ethoxy group is preferred), an aryl group (the number of carbon atoms is preferably 6-20, for example, a phenyl group is preferred), a fluoroalkyl group or an aralkyl group, or a hydrocarbon group in combination therewith, or a fluorine atom. A and B each independently represent a substituent containing an oxygen atom or a nitrogen atom such as a hydroxy group, a carboxylic acid group, an amino group, an amide group, an imino group, or a phenol group. When a plurality of R ³ , R ⁴ , A or B are included in the structure X, each of them may be the same or different. In addition, continuous bonds between C (carbon atoms) are usually a single bond, but may include a double bond or a triple bond, and the bond between C may include a linking group such as an ether group, amide group, ester group, carbonyl group or carbonate group. The number of bonds of one C to any other C is 1-4, and the long chain hydrocarbon chain may have a branched structure or may have a radial structure.

Y represents a hydrophilic group having hydrophilicity, the hydrophilic group contains an atom selected from a hydrogen atom, a carbon atom, an oxygen atom, a nitrogen atom, a phosphorus atom, and a sulfur atom. Specific examples thereof include: a hydroxy group, a carboxylic acid group, an amino group, an amide group, an imino group, and a phenol group; a polyoxyalkylene group (the number of carbon atoms of an oxyalkylene group is preferably 1 to 4, (for example, a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, or a polyoxyalkylene group in combination with them is preferred); a hydrophilic group having a plurality of hydroxy groups such as an erythritol group, xylitol group, sorbitol group, glycerol group and ethylene glycol group; hydrophilic group itself such as sulfonic acid group, sulfate group, phosphoric acid group, sulfobetaine group, carbobetaine group, phosphobetaine group, quaternary ammonium group, imidazolium betaine group, epoxy group , a carbinol group and a methacryl group, or a hydrophilic group formed from a combination thereof In addition, when Y is plural, the groups in the plurality may be the same or different.

In structures ZY and YZY, Y is bonded to Z or to a group at the end of Z. When Y is bonded to a group at the end of Z, the group at the end of Z is bonded to Y, for example, after removal of hydrogen atoms, and the like, in an amount identical to the number of bonds with Y.

In this structure, the requirements for spreading ratio, water solubility and interface tension discussed above can be met by selecting the hydrophilic groups Y, A and B from the specifically described groups. Thus, the target effect of the destruction of the liquid film develops.

{0059}

The liquid film breaker is preferably a compound obtained by arbitrarily combining the structures represented by any of the following Formulas (12) to (25) as specific examples of the structures Z, Z-Y and Y-Z-Y. In addition, from the viewpoint of the effect of breaking the liquid film, it is preferable that this compound has a weight average molecular weight in the above range.

{0060}

{0061}

In Formulas (12) to (25), M ² , L ² , R ⁴¹ , R ⁴² and R ⁴³ denote the following monovalent or multivalent (divalent or higher valence) groups.

M ² represents a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, a group containing a polyoxyalkylene group in combination therewith, an erythritol group, a xylitol group, a sorbitol group, a hydrophilic group having a plurality of hydroxy groups such as a glycerol group or an ethylene glycol group, a hydroxy group carboxylic acid group, mercapto group, alkoxy group (the number of carbon atoms is preferably 1 to 20, for example, methoxy group is preferred), amino group, amide group, imino group, phenol group, sulfonic acid group, quaternary ammonium group, sulfobetaine group , a hydroxysulfobetaine group, a phosphobetaine group, an imidazolium betaine group, a carbobetaine group, an epoxy group, a carbinol group, a (meth) acryl group, or a functional group in combination therewith.

L ² represents a linking group such as an ether group, an amino group, an amide group, an ester group, a carbonyl group, a carbonate group, a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, or a polyoxyalkylene group in combination therewith.

R ⁴¹ , R ⁴² and R ⁴³ each independently represent different substituents such as a hydrogen atom, an alkyl group (the number of carbon atoms is preferably from 1 to 20, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group , pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, nonyl group or decyl group is preferred), alkoxy group (the number of carbon atoms is preferably from 1 to 20, for example, methoxy group or ethoxy group is preferred), an aryl group (the number of carbon atoms is preferably from 6 to 20, for example, a phenyl group is preferred), a fluoroalkyl group, an aralkyl group, a hydrocarbon group in combination with them, or a halogen atom (for example, a fluorine atom is preferred).

When R ⁴² is a multivalent group, R ⁴² is a group formed by further removing one or more hydrogen atoms from each substituent described above.

In addition, on completion of the chemical bond described in each structure may arbitrarily join any other structure or may be introduced hydrogen atom.

{0062}

In addition, specific examples of the above compounds include, but are not limited to, the following compounds.

First, examples thereof include a polyether compound and a nonionic surfactant. Specific examples thereof include a polyoxyalkylene alkyl (POA) ether represented by any of the formulas in Formula [V]; polyoxyalkylene glycol, which is represented by Formula [VI] and has a weight average molecular weight of 1000 or more, steareth, beheneth, PPG (polyethylene glycol) myristyl ether, PPG stearyl ether and PPG behenyl ether. As the polyoxyalkylene alkyl ether, lauryl ether is preferable, to which 3 moles or more and 24 moles or less of POP are added, and preferably 5 moles or the like. As the polyether compound, polypropylene glycol having a weight average molecular weight of 1000 to 10000 is preferable, and preferably 3000, to which polypropylene glycol is added in an amount of 17 mol or more and 180 mol or less, and the preferred amount is about 50 mol or something like that. In addition, the measurement of the weight average molecular weight can be carried out using the above measurement method.

{0063}

Polyether compounds or nonionic surfactant are preferably contained at 0.1% by mass or more; and at 8.0% by mass or less in terms of the proportion of content (Oil Per Unit) with respect to the mass of fibers. The proportion (OPU) of the polyether compound or nonionic surfactant is more preferably 1.0 mass% or less, and even more preferably 0.4 mass% or less. Thus, the topsheet 1 has a preferred texture. In addition, from the point of view of effective demonstration of the effect of destruction of the liquid film under the action of a polyether compound or a nonionic surfactant, the proportion (OPU) is more preferably 0.15 mass% or more, and even more preferably 0.2 mass% or more.

{0064}

{0065}

{0066}

In the Formulas, L ²¹ represents a linking group such as an ether group, an amino group, an amide group, an ester group, a carbonyl group, a carbonate group, a polyoxyethylene group, a polyoxypropylene group or a polyoxybutylene group, or a polyoxyalkylene group in combination therewith. R ⁵¹ represents various substituents such as hydrogen atom, methyl group, ethyl group, propyl group, isopropyl group, butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, nonyl group, decyl group, methoxy group, ethoxy a group, a phenyl group, a fluoroalkyl group, an aralkyl group, a hydrocarbon group combined with them, or a fluorine atom. In addition, a, b, m and n each independently represent an integer of 1 or more. C _m H _n in this document denotes an alkyl group (n = 2m + 1) and C _a H _b denotes an alkylene group (a = 2b). In addition, the number of carbon atoms and the number of hydrogen atoms are each independently defined in each of formulas [V] and [VI], and they are not always the same integers, and they may be different. Below, the same rule applies also to m, m ', m'', n, n' and n '' in Formulas [VII] - [XV]. In addition, ʺmʺ in - (C _a H _b O) _m - is an integer of 1 or more. The values of the repeating units are each independently defined in each of formulas [V] and [VI], and they do not always represent the same integer, and they may be different.

{0067}

The spreading coefficient, surface tension and water solubility described above in the second embodiment can each be set in a predetermined range for the polyether or nonionic surfactant compound, for example, by the number of moles of the polyoxyalkylene group or the like. ... From this point of view, the number of moles of the polyoxyalkylene group is preferably 1 or more and 70 or less. When the amount is 1 or more, the above-described effect of breaking the liquid film is effectively demonstrated. From this point of view, the number of moles is more preferably 5 or more, and even more preferably 7 or more. On the other hand, the amount of added moles is preferably 70 or less, more preferably 60 or less, and even more preferably 50 or less. Thus, the entanglement of molecular chains is moderately weakened, and the diffusion of the agent in the liquid film is excellent, and such a case is preferable.

In addition, the spreading coefficient, surface tension, interface tension, and water solubility described above can each be set in a predetermined range, for bonding a polyether or a nonionic surfactant, by simultaneously using a water-soluble polyoxyethylene group and a water-insoluble polyoxypropylene group. , and a water-insoluble polyoxybutylene group, by changing the chain length for the hydrocarbon chain, by using a material having chain branching in the hydrocarbon chain, by using a material having a double bond in the hydrocarbon chain, by using a material having a benzene ring or a naphthalene ring in the hydrocarbon chain, by appropriately combining all of the above, or the like.

{0068}

Second, examples include a hydrocarbon compound containing 5 or more carbon atoms. From the viewpoint that spreading over the surface of the liquid film is further enhanced in a fluid state, the number of carbon atoms is preferably 100 or less, and more preferably 50 or less. The hydrocarbon compound excluding the polyorganosiloxane is not limited to a straight chain only, and may have a branched chain, and the chain is not limited in any way to a saturated chain or an unsaturated chain. In addition, the hydrocarbon compound may contain a substituent such as an ester and an ether in its middle and at the end. First of all, a hydrocarbon compound in a fluid at ambient temperature is preferred and used by itself. The hydrocarbon compound is preferably contained at 0.1% by mass or more and at 13% by mass or less in terms of the proportion of content (Oil Per Unit) with respect to the mass of fibers. The content ratio (OPU) of the hydrocarbon compound is preferably 1.0 mass% or less, more preferably 0.99 mass% or less, and even more preferably 0.4 mass% or less. So the top sheet is 1 has a preferred texture. In addition, from the point of view of effective demonstration of the effect of destruction of the liquid film with the proportion of the content of the hydrocarbon compound, the proportion of the content (OPU) is more preferably 0.15 mass% or more, and even more preferably 0.2 mass% or more.

{0069}

Examples of the hydrocarbon compound include oil or fat such as natural oil or natural fat. Specific examples thereof include palm oil, camellia oil, castor oil, coconut oil, corn oil, olive oil, sunflower oil, tall oil, and mixtures thereof.

In addition, specific examples thereof include a fatty acid as represented by Formula (VII) such as caprylic acid, capric acid, oleic acid, lauric acid, palmitic acid, stearic acid, myristic acid, behenic acid, and mixtures thereof.

{0070}

{0071}

In Formula [VII], m and n each independently represent an integer equal to 1 or greater. C _m H _n in this document denotes a hydrocarbon group of the above-described fatty acid.

{0072}

Examples of straight chain or branched chain, saturated or unsaturated, or substituted or unsubstituted polyhydric alcohol fatty acid ester or mixture of polyhydric alcohol fatty acid esters include glycerol fatty acid ester or pentaerythritol fatty acid ester as represented by Formula [ VIII-I] or [VIII-II], and specific examples thereof include glyceryl tricaprylate, glyceryl tripalmitate, and mixtures thereof. In addition, a certain amount of monoester, diester, and triester is typically mixed with a glycerol fatty acid ester or a pentaerythritol fatty acid ester. Specific preferred examples of the glycerol fatty acid ester include a mixture of glyceryl tricaprylate and glyceryl tricapriate. In addition, from the viewpoint of reducing the tension at the interface to obtain a higher spreading coefficient, it is possible to use a polyhydric alcohol fatty acid ester into which a polyoxyalkylene group is introduced to such an extent that water insolubility can be maintained.

{0073}

{0074}

{0075}

In Formulas [VIII-I] and [VIII-II], m, m ', m ″, n, n ′ and n ″ are each independently an integer of 1 or more. set m or set n, each can be the same or different from each other. C _m H _n , C _m 'H _n ' and C _m ″ H _n ″ are each, as used herein, a hydrocarbon group of the above-described fatty acid.

{0076}

Examples of a fatty acid or fatty acid mixture in which a straight chain or branched, saturated or unsaturated fatty acid forms a polyol and an ester with a polyol containing a large amount of hydroxy groups, and a part of the hydroxy groups is left without esterification, include a partially esterified ester product glycerol and fatty acid, sorbitan fatty acid ester or pentaerythritol fatty acid ester as represented by any of the formulas in Formula [IX], any of the formulas in Formula [X], or any of the formulas in Formula [XI]. Specific examples thereof include ethylene glycol mono-myristate, ethylene glycol dimyristate, ethylene glycol palmitate, ethylene glycol dipalmitate, glyceryl dymyristate, glyceryl dipalmitate, glyceryl monooleate, sorbitan monooleate, sorbitan monostearate, sorbitan tane diristolerate. In addition, a certain amount of the fully esterified compound is generally introduced into a mixture formed from a partially esterified glycerol fatty acid ester product, a sorbitan fatty acid ester, a pentaerythritol fatty acid ester, or the like.

{0077}

{0078}

In Formula [IX], m and n each independently represent an integer equal to 1 or greater. A set of m or a set of n, each, can be the same or different. C _m H _n in this document denotes a hydrocarbon group of the above-described fatty acid.

{0079}

{0080}

In Formula [X], R ⁵² is a straight chain or branched chain or saturated or unsaturated hydrocarbon group (alkyl group, alkenyl group, alkynyl group or the like) containing 2 or more and 22 or less carbon atoms. Specific examples thereof include a 2-ethylhexyl group, a lauryl group, a myristyl group, a palmityl group, a stearyl group, a behenyl group, an oleyl group, and a linoleic group;

{0081}

{0082}

In Formula [XI], m and n each independently represent an integer of 1 or more. A plurality of m or a plurality of n, each, can be the same or different from each other. C _m H _n in this document denotes a hydrocarbon group of the above-described fatty acid.

{0083}

In addition, examples include sterol, phytosterol, and a sterol derivative. Specific examples thereof include cholesterol, sitosterol, stigmasterol, ergosterol, and mixtures thereof, each having a sterol structure of Formula [XII].

{0084}

{0085}

Specific examples of the alcohol include lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, cetostearyl alcohol, behenyl alcohol, and mixtures thereof as represented by Formula [XIII].

{0086}

{0087}

In Formula [XIII], m and n each independently represent an integer equal to 1 or greater. C _m H _n in this document denotes a hydrocarbon group of the alcohol described above.

{0088}

Specific examples of the fatty acid ester include isopropyl myristate, isopropyl palmitate, cetylethylhexanoate, triethylhexanoin, octyldodecyl myristate, ethylhexyl palmitate, ethylhexyl stearate, butyl stearate, myristyl myristate, stearylistearate, and mixtures of Fethylen and Xolystearate, such as cholesterol IV, as cholesterol IV.

{0089}

{0090}

In Formula [XIV], m and n each independently represent an integer equal to 1 or greater. The two parts of C _m H _n in this document can be the same or different. C _m H _n in C _m H _n —COO— represents the hydrocarbon group of each fatty acid described above. C _m H _n in —COOC _m H _n is a hydrocarbon group derived from an alcohol which forms an ester.

{0091}

In addition, specific examples of the wax include ceresin, paraffin, petrolatum, mineral oil, and liquid isoparaffin as represented by Formula [XV].

{0092}

{0093}

In Formula [XV], m and n each independently represent an integer equal to 1 or greater.

{0094}

The spreading coefficient, surface tension, water solubility and interface tension in the second embodiment, each, as discussed above, can be set in a predetermined range in the above-described hydrocarbon compound containing 5 or more carbon atoms, for example, by introducing therein a small amount of a hydrophilic polyoxyethylene group to such a degree that insolubility in water can be maintained by introducing a polyoxypropylene group or a polyoxybutylene group which is hydrophobic but can lower the interface tension by changing the chain length for the hydrocarbon chain through the use of a material, having chain branching in a hydrocarbon chain, by using a material having a double bond in a hydrocarbon chain, by using a material having a benzene ring or a naphthalene ring in a hydrocarbon chain, or anything like that.

{0095}

In the nonwoven fabric of the present invention, in addition to the liquid film breaker discussed above, other components may also be included as needed. In addition, the liquid film breaking agent of the first embodiment and the liquid film breaking agent of the second embodiment can be used in combination, in addition to the aspect of separate use. In this regard, the same rule also applies to the first compound and the second compound in the liquid film breaker of the second embodiment.

{0096}

In addition, in the nonwoven fabric of the present invention, when a liquid film breaker or an anionic surfactant such as a phosphoric acid ester contained therein is identified, the identification method described in the above method for measuring surface tension (γ _w ) can be applied. liquid films (liquid having a surface tension of 50 mN / m) or the like.

In addition, when the component of the liquid film disrupting agent is a compound in which the main chain has a siloxane chain, or a hydrocarbon compound in which the number of carbon atoms is 1 or more and 20 or less, the fraction of their content (OPU) with respect to the mass the fiber can be determined by dividing the fraction of the liquid film breaker by the fiber weight, based on the weight of the material obtained by the analytical method discussed above.

{0097}

The nonwoven fabric of the present invention is formed into a product having high liquid permeability regardless of fiber thickness or fiber spacing. However, the nonwoven fabric of the present invention is particularly effective when fine fibers are used. If thin fibers are used to form a nonwoven fabric having a softer texture than usual, the distance between the fibers decreases and the number of narrow areas between the fibers increases. For example, usually, in the case of a nonwoven fabric (fineness: 2.4 dtex), commonly used, the distance between the fibers is 120 µm and the area fraction of the liquid film to be formed becomes about 2.6%. However, if the fineness is reduced to 1.2 dtex, the fiber spacing is 85 µm, and the liquid film area ratio increases to about 7.8%, to an extent that is about 3 times that of a conventional nonwoven fabric. In contrast, the liquid film breaker of the present invention reliably breaks the liquid film that often occurs, and thus the amount of residual liquid is reduced. As discussed later, the area fraction of the liquid film is expressed in terms of the area fraction of the liquid film to be calculated from image analysis of the surface of the nonwoven fabric and has a strong correlation with the state of the residual liquid at the outermost surface of the surface material. Therefore, if the area fraction of the liquid film is reduced, liquid near the skin is eliminated, the level of comfort after discharge is improved, and thus an absorbent article that is comfortable to wear even after discharge is obtained. On the other hand, the amount of residual liquid discussed later means the amount of liquid retained in the nonwoven fabric as a whole. If the area fraction of the liquid film decreases, the amount of residual liquid decreases, although the decrease is not necessarily proportional. In addition, the whiteness of the surface is expressed in terms of the L value discussed below. With respect to the value of L, its numerical value tends to increase as the amount of residual liquid decreases, which is caused by the destruction of the liquid film on the surface, while the whiteness becomes easily visible visually. In the nonwoven fabric containing the liquid film breaker of the present invention, even if the fibers become thinner, the liquid film area ratio and the residual liquid amount decrease, and the L value may increase, and for this reason, both the skin dry feeling and the soft texture imparted by the reduction in the thickness of the fibers can be satisfied at a high level. In addition, the nonwoven fabric of the present invention is used as a constituent member such as a surface material of an absorbent article to achieve a high dry feeling in the portion in contact with the skin, and it is possible to make bodily fluid contamination invisible by visual whiteness, and for this reason an absorbent article can be obtained for which leakage anxiety can also be suppressed and significant wearing comfort is realized.

From the viewpoint of increasing the texture softness of the nonwoven fabric containing such a liquid film breaker, the distance between the fibers of the nonwoven fabric is preferably 150 µm or less, and more preferably 90 µm or less. In addition, from the viewpoint of suppressing the negative effect on liquid permeability caused by too small a fiber spacing, its lower limit is preferably 50 µm or more, and more preferably 70 µm or more. Specifically, the distance between the fibers is preferably 50 µm or more and 150 µm or less, and more preferably 70 µm or more and 90 µm or less.

The fineness of the fibers in this case is preferably 3.3 dtex or less, and more preferably 2.4 dtex or less. In addition, its lower limit is preferably 0.5 dtex or more, and more preferably 1.0 dtex or more. Specifically, the fineness is preferably 0.5 dtex or more and 3.3 dtex or less, and more preferably 1.0 dtex or more and 2.4 dtex or less.

{0098}

(Method for measuring distance between fibers)

The distance between the fibers is determined by measuring the thickness of the nonwoven fabric as a measurement object, and then applying the measured value to expression (2).

First, the nonwoven fabric as a measurement object is cut into pieces of 50 mm in the longitudinal direction × 50 mm in the transverse direction to obtain a cut piece of nonwoven fabric. When carved a piece having these dimensions cannot be obtained, as in the case where the nonwoven fabric is the object of measurement collected in an absorbent article such as a sanitary product and a disposable diaper, the cut piece is obtained by cutting the nonwoven fabric to the maximum size that can be obtained.

The thickness of the cut piece is measured under a pressure of 49 Pa. The measurement environment was a temperature of 20 ± 2 ° C and a relative humidity of 65 ± 5%, and a microscope (VHX-1000, manufactured by KEYENCE Corporation) was used as the measurement instrument. First, an enlarged photograph of a cross-section of the nonwoven fabric is obtained. A piece of known size is photographed on the enlarged photograph. An enlarged photo of a cross-section of a nonwoven fabric is overlaid with a scale for measuring the thickness of the nonwoven fabric. The operation described above is carried out 3 times, and the average of 3 measurements is taken as the dry thickness (mm) of the nonwoven fabric. In addition, in the case of a laminated product, the boundary is different from the fiber diameter for calculating the thickness.

Then, the distance between the fibers in the fibers that make up the nonwoven fabric as an object of measurement is determined from the Formula based on the Wrotnowski assumption shown below. A formula based on Wrotnowski's assumption is typically used to determine the fiber spacing for the fibers that make up a nonwoven fabric. In accordance with the formula based on the assumption of Wrotnowski, the distance between the fibers A (μm) is determined using the following expression (2) using the thickness h (mm) of the nonwoven fabric, its base weight e (g / m ² ), the diameter of the fibers d ( μm) for the fibers that make up the nonwoven fabric, and the density of its fibers ρ (g / cm ³ ). In addition, when the nonwoven fabric has a convex-concave shape, the fiber spacing is calculated using the thickness of the nonwoven fabric h (mm) in the convex portion as a representative value.

With respect to the fiber diameter d (µm), 10 pieces of fiber cross-sections are measured for the cut fibers using a scanning electron microscope (DSC6200, manufactured by Seiko Instruments Inc.), and their average value is taken as the fiber diameter.

Fiber density ρ (g / cm ³ ) is measured using a density gradient tube according to the measurement method described as the density gradient tube method in JIS L1015 Test methods for chemical staple fibers.

With respect to the basis weight e (g / m ² ), the nonwoven fabric - the measurement object is cut into pieces having a predetermined size (0.12 m × 0.06 m or the like), and after measuring the weight, the basis weight is determined by calculating in accordance with the expression "massa / area defined by specified size = basis weight (g / m ²⁾ ."

{0099}

(2)

(2)

{0100}

(Method for measuring the fineness of constituent fibers)

The fineness is calculated by measuring the cross-sectional shape of a fiber with an electron microscope or the like to measure the cross-sectional area of the fiber (the cross-sectional area of each resin component if the fiber is formed from a plurality of resins) while indicating the kind of resin (also an approximate ratio of components in the case of multiple resins) using DSC (Differential Scanning Calorimeter) for density identification. For example, if a PET-only staple fabric is used, the cross-section is first observed to calculate the cross-sectional area. The fiber is then measured by DSC to identify by melting point or peak shape whether the fiber is a single-component resin and that the component is a PET core. The fineness is then calculated by calculating the fiber weight using the density of the PET resin and the cross-sectional area.

{0101}

As the fibers that make up the nonwoven fabric of the present invention, fibers commonly used in this kind of product can be used without any limitation. Specific examples include various fibers such as hot melt composite fibers sheath-core, thermally elongated fibers, thermally non-extensible fibers, heat shrinkable fibers, non-heat shrinkable fibers, three-dimensionally twisted fibers, potentially twisted fibers, and hollow fibers. In particular, the fibers preferably contain a thermoplastic resin. In addition, thermally non-stretching fibers and fibers without heat shrinkage are preferably are thermally alloyed... The sheath-core composite fibers may be of the sheath-core concentric type, the eccentric sheath-core type, the side-by-side type, or the deformed type, and are preferably of the concentric sheath-core type. In the production of fibers and nonwoven fabric, a liquid film breaker or a liquid film breaker and an anionic surfactant such as a phosphoric acid ester can be incorporated into the fibers at any stage. For example, a liquid film breaker or a mixture of a liquid film breaker and an anionic surfactant such as phosphoric acid is blended into a fiber sizing agent that is typically to be used in fiber spinning, and the resulting mixture can be applied to the fibers, or an agent to break the liquid film, or a mixture of a liquid film breaker and an anionic surfactant such as phosphoric acid may be blended into the fiber finishing sizing before or after the fibers are stretched, and the resulting mixture can be applied to the fibers. In addition, a liquid film breaker or an anionic surfactant such as a phosphoric acid ester may be blended into a fiber treating agent that is generally to be used to form a nonwoven fabric, and the resulting mixture may be applied to the fibers as a coating, or on fibers after the formation of the nonwoven fabric.

However, in the nonwoven fabric having a concave portion of the present invention, from the viewpoint of keeping the degree of hydrophilicity in the high density portion high, the agent is preferably coated thereon after the nonwoven fabric is formed. This point will be described later.

{0102}

The nonwoven fabric of the present invention contains a liquid film breaker or an anionic surfactant such as a phosphoric acid ester, in addition, and therefore it is excellent in suppressing the amount of residual liquid according to various fiber structures. In particular, such characteristics are more pronounced in the non-high density portion than in the high density portion which is formed by compression molding through embossing processing. Therefore, even if a large amount of liquid is spilled on the nonwoven fabric, a liquid penetration passage between the fibers is always provided, and the nonwoven fabric is excellent in liquid permeability. Thus, various functions can be provided for the nonwoven fabric without being limited by the problems of fiber spacing and liquid film formation. For example, a nonwoven fabric can be formed from a single layer or from multiple layers from two or more layers. In addition, the nonwoven fabric may have a flat shape, a convex-concave shape on one side or on both sides, or a shape that is varied with respect to the fiber basis weight or fiber density. In addition, the window of opportunity is also expanding with regard to combinations with absorbent materials. In addition, when the nonwoven fabric is formed from a plurality of layers, the liquid film breaker can be retained in all or part of the layers. The liquid film breaker is preferably retained at least in the layer on the side on which the liquid is directly received. For example, when the nonwoven fabric of the present invention is included as a topsheet in an absorbent article, the liquid film breaker is preferably held in at least a layer on the surface side in contact with the skin.

{0103}

In the nonwoven fabric of the present invention, in the non-high density portion, the liquid film breaker is preferably localized around at least a portion of the points at which the fibers interlace with each other or the points where the fibers are fusion bonded to each other. The term `` localization '' of the liquid film breaker herein means a state in which the liquid film breaker does not adhere uniformly to the entire surface of the fibers that make up the nonwoven fabric, but the liquid film breaker adheres to them locally near the points at which the fibers intertwine. with each other, or the points where the fibers are bonded by fusion with each other, rather than across the entire surface of the fibers. Specifically, this term can be defined when the concentration of the agent for breaking the liquid film near the points at which the fibers are intertwined with each other, or the points where the fibers are bonded by fusion with each other, is higher compared to the surface of the fibers (with the surface of the fibers between the points of interlacing or between fusion bonding points). Sometimes, a liquid film breaker near the points where the fibers are intertwined with each other, or the points where the fibers are fused together, can adhere to them in such a way that it partially covers the space between the fibers, centered on the points where the fibers are intertwined with each other, or the points where the fibers are fused together. The concentration of the liquid film breaker in the vicinity of the points at which the fibers entwine with each other, or the points where the fibers are fusion-bonded with each other, is preferably as high as possible. The concentration varies depending on the type of agent used for breaking the liquid film, the type of fibers used, or on the effective proportion of the components when the agent is mixed with other agents, or something similar, and, therefore, it cannot be determined unambiguously, but from the point From the point of view of demonstrating the above-discussed effect of destruction of the liquid film, the concentration can be determined accordingly.

The localization of the agent for the destruction of the liquid film contributes to the additional development of the effect of the destruction of the liquid film. That is, the area near the points where the fibers are intertwined with each other, or the points where the fibers are fused with each other, is a place where a liquid film is especially easily formed, and for this reason, there is more agent in this place. to break the liquid film, essentially for simple direct interaction with the liquid film.

Such localization of the liquid film breaker is preferably 30% or more, more preferably 40% or more, and even more preferably 50% or more of the locations near the points where the fibers are intertwined with each other, or the points where the fibers are bonded by fusion to each other, from the nonwoven fabric as a whole. In a nonwoven fabric, in a place where the distance between the points at which the fibers are intertwined with each other or the distance between the points where the fibers are fusion bonded with each other is relatively small, the space between the fibers is small, and it is particularly easy to form therein. liquid film. For this reason, if the agent for breaking the liquid film is selectively localized near the points at which the fibers are intertwined with each other, or the points where the fibers are fused with each other, at the place where the space between the fibers is narrow, the effect of breaking the liquid film develops especially efficiently, and such a case is preferred. In addition, in the case of selective localization as described above, it is preferable to adjust the coating ratio of the liquid film breaking agent so that the coating ratio of the liquid film breaking agent for a relatively narrow space between fibers is increased, and the coating ratio of the liquid film breaking agent for the comparatively large space between the fibers was reduced. Thus, while the liquid permeability in the nonwoven fabric is maintained, the fracture effect in the portion in which the capillary force is high and the liquid film is easily formed can effectively develop, and the effect on reducing the amount of residual liquid in the nonwoven fabric is generally improved. The term "relatively narrow inter-fiber space" herein means a fiber-to-fiber space having a fiber-to-fiber distance of 1/2 or less with respect to the fiber-to-fiber distance defined in (Method for Measuring Fiber Distance) discussed above.

{0104}

(Method for confirming the localized state of an agent for breaking a liquid film)

The above-described localized state of the liquid film breaker can be confirmed by the following method.

First, a piece of 5 mm × 5 mm is cut from the nonwoven fabric, and this piece is attached to the sample stage using carbon tape. The sample stage is placed in a scanning electron microscope (S4300SE / N, manufactured by Hitachi, Ltd.) in a non-vapor deposition state and brought into a low vacuum state or a vacuum state. Localization is detected using an angular reflective electron detector (attachment). As the atomic number increases, the emission of reflective electrons is further facilitated. Thus, the part coated with a liquid film breaker containing a large number of oxygen atoms or silicon atoms appears white, where the oxygen atoms or silicon atoms each have a higher atomic number than the carbon atoms or hydrogen atoms, which are mainly polyethylene (PE), polypropylene (PP) or polyester (PET). Therefore, the localized condition can be confirmed by whiteness. In addition to this, the whiteness rises when the atomic number rises or when the adhered amount rises.

{0105}

In addition, in the manufacture of the nonwoven fabric of the present invention, the nonwoven fabric from the raw materials can be produced using the method commonly used for this kind of article, without any limitation. For example, as a method for forming a web of fibers, a carding method, a dry air spinning method, a spunbond method, or the like can be used. As a method for converting a web of fibers into a nonwoven fabric, various nonwoven fabric forming methods to be commonly used, such as hydroentangling, needle punching, chemical bonding, and dot embossing, can be used. The concave portion of the nonwoven fabric of the present invention is formed by embossing by separating a plurality of concave portions in a plane direction. The arrangement of the concave portions in the plane direction can be set appropriately according to the application. A nonwoven fabric includes not only a material that is obtained only in the above step, but also a material that is obtained by adding the above step to a nonwoven fabric that is obtained using any other method, or to one that is obtained by performing a step of any or kind after the stage discussed above.

{0106}

In the method for producing the nonwoven fabric of the present invention, after the nonwoven fabric is formed as discussed above, specific examples include a method of applying a liquid film breaker by itself or a solution containing a liquid film breaker on the raw material nonwoven fabric. Specific examples of the solution include a solution in which a liquid film breaker is diluted with a solvent (hereinafter, this solution is also referred to as a liquid film breaker solution). Specific examples of the solvent with which the liquid film breaker is diluted include an alcohol such as ethanol. In addition, an anionic surfactant of the phosphoric acid ester type can be mixed with a solution containing a liquid film breaker. In this case, the proportion of the liquid film breaker with respect to the anionic surfactant of the phosphoric acid ester type is preferably as discussed above. As the solvent, a solvent can be used without any limitation in which the liquid film breaker having a significantly low water solubility can be moderately dissolved or dispersed and emulsified to easily apply the coating agent to the nonwoven fabric. Specific examples of the solvent that dissolves the agent include an organic solvent such as ethanol, methanol, acetone and hexane, or liquids where the agent is converted into a liquid emulsion, water can of course also be used as a solvent or dispersing medium, and specific examples of an emulsifying agent the agent used in the emulsification of the agent include various surfactants including a phosphoric acid alkyl ester, a fatty acid amide, an alkyl betaine, and an alkyl sodium sulfosuccinate. In addition, the precursor nonwoven means a nonwoven before the liquid film breaking agent is applied thereon, and as a method for producing it, the production method to be generally used as discussed above can be used without any limitation.

{0107}

As a method for coating an agent on a raw material nonwoven fabric, the method used in this nonwoven fabric production method can be used without any limitation. Specific examples include spray coating, slot coating, and gravure, flexographic, and immersion coating.

In the nonwoven fabric having a convex-concave structure of the present invention, from the viewpoint of keeping the degree of hydrophilicity at a high level in the high density portion in the lower portion of the concave portion, the coating location is preferably controlled by a flexographic printing system. In addition, from the point of view of the above-discussed localization of the liquid film breaker near the points at which the fibers are intertwined with each other, or the points where the fibers are fused together, the application method by means of a flexographic printing system is particularly preferable from the point of view of further clearly the achieved localization of the agent for the destruction of the liquid film.

{0108}

Here, as a preferred embodiment of the method for producing the nonwoven fabric of the present invention, a method for coating a liquid film breaker using a flexographic printing system will be described. Flexographic printing system means a method of coating a liquid film breaker on a soft nonwoven fabric by applying flexographic printing, which is a type of relief printing. Accordingly, the coating processing can be applied here using an apparatus commonly used for flexographic printing. Coating treatment is applied thereto using an apparatus obtained by combining at least an anilox roll and a flexographic plate, which is a cylinder with a plate with a relief. The flexographic plate is made of rubber or resin. The anilox roll, which serves as a unit for introducing the agent for breaking the liquid film into the flexographic printing system, has small concave cells on its surface. Convex parts on the surface of the flexographic plate, which is a cylinder with a plate with a relief, are located in accordance with the cells of the anilox roll.

Specifically, a method for coating a liquid breaker with a flexographic printing system, for example, is a method as described below. However, the method is not limited to this, and an apparatus and method for use in flexographic printing can be appropriately adopted. First, the anilox roll is positioned and rotated so that the surface of the anilox roll is immersed in a paint chamber into which a liquid of the liquid film breaker or a dilute solution containing a breaker, namely a liquid coating, is placed. Thus, the anilox roll is filled with a liquid film breaker or a dilute solution containing a liquid film breaker, which is a liquid coating, in a plurality of concave cells located on the surface. A squeegee is then pressed against the surface of the anilox roll to scrape off excess liquid. Then, the flexo plate is pressed against the anilox roll to transfer the liquid breaker or dilute solution containing the breaker in the concave cells of the anilox roll onto the convex portions of the flexo plate. Next, the raw material nonwoven is inserted and positioned between the flexo plate and a substrate roller (impression cylinder roller). A predetermined pressure, caused by its intermediate position, is applied to the precursor nonwoven fabric to transfer the liquid film breaker or dilute solution containing the liquid film breaker present on the convex portions of the flexographic plate onto the starting material. In this case, if the structure of the arrangement of the convex parts of the flexographic plate coincides with the structure of the arrangement of the non-high-density portions of the nonwoven fabric made of raw materials, the liquid agent for breaking the liquid film or a dilute solution containing the agent for breaking the film of the liquid is transferred to the parts without high density nonwoven fabric from raw materials, and such a case is preferable.

{0109}

In the method for producing a nonwoven fabric of the present invention, the viscosity of a liquid film breaker or a dilute solution containing a liquid film breaker, which is a liquid coating, is preferably adjusted to 25 cP or more in the environment at a temperature of 25 ° C and at a relative humidity (RH) 65%. Thus, as much as possible of the transferred liquid film breaker can be retained in the non-high density portion to prevent its penetration into the nonwoven fabric. From this point of view, the viscosity of the liquid film breaker or dilute solution containing the liquid film breaker as a liquid coating is more preferably 80 cP or more, and even more preferably 150 cP or more. In addition, from the viewpoint of improving the transfer efficiency, the viscosity of the liquid film breaker or dilute solution containing the liquid film breaker is preferably 10,000 cP or less, more preferably 5,000 cP or less, and even more preferably 1000 cP. or less. In addition, the units of cP (centipoise) of viscosity are converted from Pa · s according to the equation: 1 cP = 1 × 10 ^-3 Pa · sec.

{0110}

The viscosity of a liquid film breaker or a dilute solution containing a liquid film breaker can be measured by the following method.

First, 40 g of a liquid film breaker or a dilute solution containing a liquid film breaker is disposed. Next, the viscosity of the liquid film breaker or a dilute solution containing the liquid film breaker was measured in an environment at a temperature of 25 ° C and a relative humidity (RH) of 65% using a Tuning Fork Vibro Viscometer SV-10 (manufactured by A&D Company , Limited). This operation is repeated three times and the average is taken as the viscosity. In addition, when the liquid film breaker is a solid product, the liquid film breaker is heated to a temperature melting agent for breaking the liquid film plus 5 ° C to cause a phase transition to the liquid, and the measurement is carried out while maintaining these temperature conditions.

{0111}

From the viewpoint of preventing significant elastic deformation of the flexographic plate from occurring for selectively applying the agent to the non-high density portion, the hardness of the flexographic plate is preferably 60 ° or more, more preferably 65 ° or more, and even more preferably 68 ° or more. In addition, from the viewpoint of softening the plate for coating the agent on the non-high density portion over a wide range, the hardness of the flexographic plate is preferably 90 ° or less, more preferably 85 ° or less, and even more preferably 80 ° or less.

Flexo plate hardness can be measured using the following method.

First, a flexographic plate having a thickness of 1.7 mm is placed. Shore A hardness is measured based on JIS Z2246 using this insert. The position is adjusted so that the diamond-tipped hammer falls on the convex part of the plate during measurement. In addition, the coefficients used in calculating the hardness in relation to the hammer rebound height (hammer rebound height / hammer fall height) differ depending on the specification of the measuring cylinder of the examination device, and the value shown in JIS B7727 can be used.

{0112}

From the point of view of selectively coating the agent on the non-high density part, the gap between the flexographic plate and the substrate roll is preferably -750 µm or more, more preferably -550 µm or more, and even more preferably -400 µm or more. In addition, from the viewpoint of imparting an appropriate amount of elastic deformation to the plate, the gap between the flexographic plate and the substrate roll is preferably 750 µm or less, more preferably 550 µm or less, and even more preferably 400 µm or less.

Specifically, the gap is preferably -750 µm or more and 750 µm or less, more preferably -550 µm or more and 550 µm or less, and even more preferably -400 µm or more and 400 µm or less.

{0113}

With respect to the volume of the anilox roll, when the volume is larger, the amount of coating increases, and when the volume is less, the amount of coating decreases. Then, from the viewpoint of coating the liquid film breaker in an appropriate amount to maintain a high liquid film breakage effect in use, the volume is preferably 1 cm ³ / m ² or more, more preferably 3 cm ³ / m ² or more, and even more preferably 5 cm ³ / m ² or more. In addition, from the viewpoint of suppressing the stickiness of the liquid film breaker for improving texture, the volume of the anilox roll is preferably 30 cm ³ / m ² or less, more preferably 25 cm ³ / m ² or less, and even more preferably 20 cm ³ / m ² or less.

Specifically, the volume of the anilox roll is preferably 1 cm ³ / m ² or more and 30 cm ³ / m ² or less, more preferably 3 cm ³ / m ² or more and 25 cm ³ / m ² or less, and even more preferably , 5 cm ³ / m ² or more and 20 cm ³ / m ² or less. In addition, the volume of the anilox roll means the total volume of a plurality of concave cells, each of which is located on the surface of the anilox roll.

{0114}

When adhering the liquid film breaker to the fibers, the agent is preferably used as a fiber treatment agent containing the liquid film breaker. That is, the term "fiber treating agent" described herein means an agent formed in a state where it can be easily applied as a treatment coating to a nonwoven fabric from raw materials or fibers by emulsifying an oily liquid film breaker having a very low solubility in water, with water, surfactant, and the like. In the fiber treating agent to be coated with a liquid film breaking agent, the proportion of the liquid film breaking agent is preferably 50 mass% or less with respect to the weight of the fiber treating agent. Thus, the fiber treating agent can be formed in a state in which the liquid film breaking agent is stably emulsified in the solvent as an oily component. From the viewpoint of stable emulsification, the proportion of the liquid film breaking agent is more preferably 40 mass% or less, and even more preferably 30 mass% or less, based on the mass of the fiber treating agent. In addition, from the viewpoint of realizing the above-described localization of the liquid film breaker in the nonwoven fabric by moving the liquid film breaker on the fibers at an appropriate viscosity after coating, its proportion is preferably set at the above-described proportion. From the viewpoint of effectively demonstrating the effect of breaking the liquid film, the proportion of the agent for breaking the liquid film is preferably 5% by mass or more, more preferably 15% by mass or more, and even more preferably 25% by mass or more, based on the mass of the agent. for processing fibers. In addition, the fiber treating agent containing the liquid film breaker may also contain other agents in a range that does not adversely affect the effect of the liquid film breaker. For example, the agent for treating the fibers may contain an anionic surfactant of the phosphoric acid ester as discussed above. The proportion of the liquid film breaker with respect to the anionic surfactant of the phosphoric acid ester type in this case is preferably the same as discussed above. In addition, the fiber treating agent may contain an antistatic agent or an antifriction agent used in the treatment of fibers, a hydrophilizing agent to render the nonwoven fabric moderately hydrophilic, an emulsifying agent for emulsification stability, or the like.

{0115}

As a preferred embodiment of the nonwoven fabric of the present invention containing an agent for breaking a liquid film in a non-high density portion, a specific example of a nonwoven fabric having a convex-concave shape will be described.

Specific examples include the nonwoven fabric shown in FIG. 5 using heat shrinkable fibers (first aspect). The nonwoven fabric 10 shown in FIG. 5 contains two layers: a top layer 11 on the side of the first surface 1A (surface in contact with the skin when used as a topsheet) and a bottom layer 12 on the side of the second surface 1B (non-skin contact surface when used as a topsheet). In addition, embossing (pressing) is applied to them from the side of the first surface 1B in the thickness direction, and the two layers are bonded. The portion of the space deepened by the embossing action is referred to as the embossed concave portion (concave bonding portion) 13, and the lower portion of the embossed concave portion 13 is referred to as the lower portion of the concave portion 14. This lower portion of the concave portion 14 is formed in the high density portion 8 from fibers, consolidated through embossing. A portion other than the high density portion 8 is formed in the non-high density portion 9. The bottom layer 12 is the layer in which the heat shrinkage of the heat shrinkable fibers develops. The top layer 11 is a layer containing non-heat-shrinkable fibers, and these non-heat-shrinkable fibers are partially bonded in the concave bonding portion 13. Non-heat-shrinkable fibers include, but are not limited to, fibers that do not shrink at all when heated, and fibers that shrink. to the extent that the thermal shrinkage of the heat-shrinkable fibers in the lower layer 12 is not adversely affected. From the viewpoint of forming a nonwoven fabric by heat, as non-heat-shrinkable fibers, non-heat-shrinkable fibers and thermally fused fibers are preferable.

For example, the nonwoven fabric 10 can be produced using the starting materials and the production method described in paragraphs {0032} - {0048} of JP-A-2002-187228. For example, in this production, embossing or the like is applied to the laminate between the top layer 11 and the bottom layer 12 on the side of the top layer 11, and then the heat-shrinkable fibers are thermally shrunk by heat treatment. In this case, adjacent embossed parts are attracted to each other due to shrinkage of the fibers and the spacing between them is reduced. Due to this deformation, the fibers in the top layer 11 rise upward on the side of the first surface 1C from the bottom of the concave portion 14 below the embossed concave portion 13 as the main point to form the convex portion 15. Alternatively, the top layer is laminated on the bottom layer 12 in a stretched state of the bottom layer 12, in which thermal shrinkage develops, and the above-described embossing is applied. Then, when the stretched state of the lower layer 12 relaxes, the side of the upper layer 11 protrudes upward on the side of the first surface 1A to form the convex portion 15. The embossing can be carried out by a conventional method such as thermal embossing and ultrasonic embossing. In addition, with respect to bonding both layers, a bonding method using an adhesive can be applied.

{0116}

In the thus obtained nonwoven fabric 10, the topsheet 11 is compressed and bonded to be placed on the bottom layer 12 side at the bottom of the concave portion 14 below the embossed concave portion (concave bonding portion) 13 to form a high density portion 8 containing two layers. The embossed concave portion 13, the lower portion 14 of the concave portion, and the high density portion 8 are formed on the nonwoven fabric 10 in a plane direction in the form of discrete points, and the portion surrounded by the embossed concave portion 13 is the above-described convex portion 15 formed by lifting upwards. top layer 11. The convex portion 15 has a three-dimensional solid shape and forms, for example, a dome shape. The convex portion 15 formed by the production method as described above is in a state in which the density of the fibers is lower than the density of the fibers in the lower layer 12. The interior of the convex portion 15 may be filled with fibers as shown in FIG. 5, or may to form a hollow portion in which the upper layer 11 and the lower layer 12 are separated from each other. The arrangement of the embossed concave portion 13, the lower portion of the concave portion 14, the high density portion 8, and the convex portion 15 can be arbitrarily formed, such as a lattice pattern. Specific examples of the lattice include an arrangement in which a plurality of rows formed from a plurality of embossed concave portions 13 are aligned and the spacing between the embossed concave portions 13 in each row deviates by half a pitch between adjacent rows. In addition, a shape can be formed on the plane of the embossed concave portion 13 when the shape is formed in the shape of dots, circles, an elliptical shape, a triangular shape, a rectangular shape, or any other polygonal shape, and can be arbitrarily set accordingly. In addition, the embossed concave portion 13 can be formed in the shape of lines, in addition to the shape of the dots.

{0117}

The nonwoven fabric 10 has a convex-concave surface having a convex portion 14 and an embossed concave portion 13 on the side of the first surface 1A, and therefore is excellent in shape recoverability when the nonwoven fabric 10 is stretched in a plane direction, and in compression deformability when the nonwoven fabric 10 is compressed in the thickness direction. In addition, the nonwoven fabric 10 is formed into a relatively bulky nonwoven fabric due to the upward movement of the fibers in the top layer 11, as described above. Thus, the user can feel a soft and delicate texture when touching the nonwoven fabric 10. In addition, in an absorbent article containing the nonwoven fabric 10 as the topsheet, in which the first surface 10A is used as the surface in contact with the skin and the second surface 1B is used as the surface without contact with the skin, the side of the surface in contact with the skin becomes excellent. permeability to air, due to the convex-concave shape, which has convex parts 14 and embossed concave parts 13.

In addition, the residual liquid content is reduced in the nonwoven fabric 10 by the action of the liquid film breaker, or the combined action of the liquid film breaker and an anionic surfactant such as phosphoric acid ester, as discussed above. Thus, liquid permeability using a convex-concave surface and a dense embossed portion can be further improved.

{0118}

In addition, the nonwoven fabric 10 may further comprise other layers, without limitation, with a two-layer structure of the topsheet 11 and the backsheet 12. For example, one layer or multiple layers can be sandwiched between the topsheet 11 and the backsheet 12, or one layer or the plurality of layers may be disposed on the side of the first surface 1A or on the side of the second surface 1B of the nonwoven fabric 10. One or multiple layers may be a layer containing heat shrinkable fibers or a layer containing fibers without heat shrinkage.

{0119}

Regarding the nonwoven fabric of the present invention containing the liquid film breaking agent in the non-high density portion, as other specific examples of the nonwoven fabric having a convex-concave shape, the nonwoven fabrics 20 and 30 (second aspect and third aspect) will be described. ...

{0120}

First, as shown in FIG. 6, the nonwoven fabric 20 of the second aspect has a two-layer structure having a hollow portion 21. All layers comprise thermoplastic fibers. The nonwoven fabric 20 has a bonding portion 22 in which the first nonwoven fabric 20A and the second nonwoven fabric 20B are partially heat fusion bonded by embossing . The non-bonding portion surrounded by the bonding portions 22 includes a plurality of convex portions 23 in which the first nonwoven fabric 20A projects outwardly from the second nonwoven fabric 20B to form a hollow portion 21 therein . The bonding portion 22 is a high density portion 8 of fibers consolidated by embossing when laminating the first nonwoven 20A and the second nonwoven 20B. A portion (non-binding portion) other than the high density portion 8 is a non-high density portion 9. Above the bonding portion 22, there is a concave portion 25 located between the adjacent convex portions 23 and 23. That is, the bonding portion 22 is a lower portion of the concave portion at the lower portion of the concave portion 25, and it is a high density portion 8. The concave portion 25 and the convex portion 23 constitute the concavity and convexity of the first surface 1A.

The nonwoven fabric 20 can be formed using a method that would normally be used. For example, the first nonwoven fabric 20A is given a convex-concave shape by engaging two convex-concave rolls, and then a second nonwoven fabric is laminated thereon to form a nonwoven fabric 20. From the point of view of forming a nonwoven fabric by an engaging convex-concave rolls, any material from the first the nonwoven fabric 20A and the second nonwoven fabric 20B preferably comprise thermally non-extensible thermally fusion fibers and thermally fusible fibers without heat shrinkage.

For example, when the nonwoven fabric 20 is laminated on an absorbent body as a topsheet in which the first surface 1A faces the skin-contacting surface side, and is used, the nonwoven fabric 20 is excellent in liquid permeability from the first surface 1A side to the second surface side. 1B. Specifically, the penetration of liquid through the hollow portion 21 is excellent. In addition, the pressure of the user's body is applied to the convex portions 23, and the liquid in the convex portion 23 directly migrates to the second nonwoven fabric 20B. Thus, the residual liquid content on the first surface 1A side is small. Such an effect can be constantly exhibited at a higher level by the action of the liquid film breaker or by the combined action of the liquid film breaker and an anionic surfactant such as a phosphoric acid ester, as discussed above. That is, even if long-term use occurs or there is a large amount of discharge, the penetration of the liquid is ensured by the destruction of the liquid film, and therefore, the liquid permeability can be sufficiently demonstrated as described above.

{0121}

Further, the third aspect of the nonwoven fabric 30 has a convex-concave shape with thermally elongated fibers. As shown in Fig. 7, a convex-concave shape is formed on the side of the first surface 1A. On the other hand, the shape on the side of the second surface 1B is flat or has a significantly less convex-concavity of the shape than the side of the first surface 1A. Specifically, the convex-concave shape on the first surface 1A side has a plurality of convex portions 31 and linear concave portions 32 surrounding the convex portions 31. The concave portion 32 is a portion of the space recessed from the side of the first surface 1A to the side of the second surface 1B. The lower portion 33 of the concave portion 32 (the lower portion of the concave portion) has a compression adhesion portion in which the constituent fibers of the nonwoven fabric 30 are subjected to compression bonding or adhesion and the thermally elongated fibers are in a non-elongated state. The compression adhesion portion is a high density fiber portion 8 in the lower portion 33 of the concave portion. The portion other than the high density portion 8 is a non-high density portion 9. The convex portion 31 discussed above is in the non-high density portion 9. The convex portion 31 is a portion in which the thermally elongated fibers are thermally elongated and rise upward on the side of the first surface 1A. Accordingly, the convex portion 31 is formed as a bulk portion in which the fiber density is lower than that of the high density portion 8 in the lower portion 33 of the concave portion. In addition, the linear concave portions 32 are arranged in a lattice shape, and the convex portions 31 are arranged in each area separated by the lattice in a separate manner. Thus, in the nonwoven fabric 30, the skin contact area of the wearer is suppressed, while mustiness and rash are effectively prevented. In addition, the convex portion 31 in contact with the skin becomes bulky by thermally elongating the thermally elongated fibers, taking on the appearance of a soft texture. In addition, the nonwoven fabric 30 may have a single layer structure or a multilayer structure of two or more layers. For example, when the nonwoven fabric 30 has a two-layer structure, the layer on the side of the second surface 1B preferably does not contain thermally extendable fibers or has a lower content of thermally extensible fibers than the layer on the side of the first surface 1A having a convex-concave shape. In addition, both layers are preferably bonded in the compression adhesion portion of the concave portion 32.

Also in the nonwoven fabric 30, penetration of the liquid is provided at all times by the action of the liquid film breaker or the combined action of the liquid film breaker and an anionic surfactant such as phosphoric acid ester, as discussed above. This expands the design window with respect to fiber diameter and fiber density.

Such a nonwoven fabric 30 can be obtained by the following method. First, a linear concave portion 32 is formed by thermal embossing of the fiber web. At the same time, in the lower part of the concave portion 33, the thermally elongated fibers are subjected to compression bonding or fusion without thermal elongation and are fixed. Further, the thermally extensible fibers present in the portions other than the concave portion 32 are elongated by the air blowing treatment, and the convex portion 31 is formed in the nonwoven fabric 30. In addition, the constituent fibers of the nonwoven fabric 30 may be mixed fibers of the above thermally elongated fibers and thermally non-extensible and thermally fused fibers. As these constituent fibers, for example, the fibers described in paragraphs {0013} and {0037} to {0040} of JP-A-2005-350836, the fibers described in paragraphs {0012} and {0024} to {0046} JP-A-2011-1277258, and the like.

{0122}

The nonwoven fabric of the present invention can be applied in various fields to obtain the benefits of soft texture and reduced residual liquid content. For example, such a material is preferably used as a topsheet, a second sheet (a sheet sandwiched between a topsheet and an absorbent body), an absorbent body, a cover sheet wrapping an absorbent body, or a leakage prevention sheet in an absorbent article used to absorb fluid. secreted from the body, such as a sanitary napkin, a daily napkin, a disposable diaper, urological pads; personal wiping cloth; skin care napkin; in addition, for wiping an object, or the like. When the nonwoven fabric of the present invention is used as the topsheet or second sheet of an absorbent article, the side of the topsheet of the nonwoven fabric is preferably used as the side facing the skin surface. In addition, the liquid film breaking agent of the present invention can be applied to various fibrous materials such as woven fabrics, but not limited to nonwoven fabric, as long as the liquid film breaks effect.

{0123}

With respect to the basis weight of the web used to obtain the nonwoven fabric of the present invention, the appropriate range is selected according to the specific application of the target nonwoven fabric. The basis weight of the nonwoven fabric ultimately obtained is preferably 10 g / m ² or more and 100 g / m ² or less, and particularly preferably 15 g / m ² or more and 80 g / m ² or less.

{0124}

An absorbent article used to absorb body fluid is typically provided with a topsheet, a backsheet, and an absorbent body to retain fluid between both sheets. As the absorbent body and backsheet, when the nonwoven fabric of the present invention is used as the topsheet, material that should be commonly used in the art can be used without any limitation. For example, as an absorbent mass, such a material can be used as it is, by covering with a coating sheet such as cosmetic paper and nonwoven fabric, a fiber aggregate formed from a fiber material such as pulp fibers, or a fiber aggregate with a super absorbent polymer therein. As the backing sheet, a thermoplastic resin film or a waterproof or water-repellent sheet such as a film and nonwoven laminate can be used. The backing sheet can be water and vapor permeable. The absorbent article can be further provided with various elements in accordance with the specific application of the absorbent article. Such an element is known to those skilled in the art. For example, when the absorbent article is used for a disposable diaper or sanitary napkin, a pair or two or more pairs of three-dimensional safety cuffs can be located on both the right and left side portions of the topsheet.

{0125}

With respect to the foregoing embodiments, the present invention further describes nonwoven fabrics and methods for producing nonwoven fabric, as described below.

{0126}

<1>

A method for producing a nonwoven fabric comprising the step of liquid coating a nonwoven fabric from raw materials using a flexographic printing system, wherein the liquid coating contains an agent for breaking a liquid film and has a viscosity of 25 cp or more, preferably 80 cp or more, and more preferably, 150 cP or more; and preferably 10,000 cps or less, more preferably 5,000 cps or less, and even more preferably 1,000 cps or less, and

where the raw material nonwoven has a concave part and a high density part,

and the high density portion is located at the bottom of the concave portion and has a fiber density higher than that of any other portion.

<2>

The method for producing a nonwoven fabric according to the above <1>, wherein the viscosity is 25 cps or more and 1000 cps or less.

{0127}

<3>

The method for producing a nonwoven fabric according to the above <1> or <2>, wherein the water solubility of the liquid film breaking agent is 0 g or more and 0.025 g or less, preferably 0.0025 g or less, more preferably 0, 0017 g or less, and even more preferably less than 0.0001 g; and 0 g or more, and preferably 1.0 x 10 ^-9 g or more.

<4>

The method for manufacturing a nonwoven fabric according to any of the above <1> to <3>, wherein the spreading coefficient of the liquid film breaking agent for the liquid having a surface tension of 50 mN / m is 15 mN / m or more.

<5>

The method for producing a nonwoven fabric according to any of the above <1> to <4>, wherein the surface tension of the liquid film breaking agent for the liquid having a surface tension of 50 mN / m is 20 mN / m or less.

<6>

The method for producing a nonwoven fabric according to any of the above items <1> to <3>, where the spreading coefficient of the agent for breaking a liquid film, for a liquid having a surface tension of 50 mN / m, is greater than 0 mN / m, and the surface tension of the agent for breaking film of a liquid, for a liquid having a surface tension of 50 mN / m, is 20 mN / m or less.

<7>

The method for producing a nonwoven fabric according to any of the above <1> to <6>, wherein the surface tension of the liquid film breaking agent is 32 mN / m or less.

<8>

The method for producing a nonwoven fabric according to any one of the above <1> to <7>, wherein the hardness of the flexographic plate used in coating with the flexographic printing system is 62 ° or more.

<9>

The method for producing a nonwoven fabric according to any one of the above <1> to <8>, wherein the gap between the flexographic plate and the substrate roller used in coating with the flexographic printing system is -750 μm or more and 750 μm or less, preferably , -550 µm or more, and more preferably, -400 µm or more; preferably 550 µm or less, and more preferably 400 µm or less.

<10>

The method for producing a nonwoven fabric according to any one of the above <1> to <9>, wherein the volume of the anilox roll used in coating with the flexographic printing system is 1 cm ³ / m ² or more and 30 cm ³ / m ^2, or less, preferably 3 cm ³ / m ² or more, and more preferably 5 cm ³ / m ² or more; and preferably 25 cm ³ / m ² or less, and more preferably 20 cm ³ / m ² or less.

{0128}

<11>

Nonwoven fabric obtained using the method according to any of the above items <1> to <10>.

{0129}

<12>

A nonwoven fabric containing a concave portion and a high density portion that is located at the bottom of the concave portion and has a fiber density higher than that of any other portion,

wherein the nonwoven fabric is divided into a high density portion and a non-high density portion other than a high density portion, and the nonwoven fabric contains an agent for breaking a liquid film in the non-high density portion.

{0130}

<13>

The nonwoven fabric according to <11> or <12> above, wherein the spreading coefficient of the liquid film breaking agent for the liquid having a surface tension of 50 mN / m is 15 mN / m or more, preferably 20 mN / m or more more preferably 25 mN / m or more, and even more preferably 30 mN / m or more; preferably 50 mN / m or less.

{0131}

<14>

A nonwoven fabric containing a concave portion and a high density portion that is located at the bottom of the concave portion and has a fiber density higher than that of any other portion,

wherein the nonwoven fabric is divided into a high density portion and a non-high density portion other than a high density portion, and the nonwoven fabric has the following C1 compound in the non-high density portion:

[Connection C1]

A compound having a spreading coefficient of 15 mN / m or more for a liquid having a surface tension of 50 mN / m.

{0132}

<15>

The nonwoven fabric according to any of the above <11> to <14>, wherein the liquid film breaker or compound C1 comprises a compound having at least one kind of structure selected from the group consisting of the following structures X, XY and YXY:

where structure X denotes a siloxane chain having a structure in which any of the main structures> C (A) - (C denotes a carbon atom, in addition, <,> and -, each denotes a chemical bond, hereinafter we are talking about the same) , -C (A)₂-, -C (A) (B) -,> C (A) -C (R^one) <,> C (R^one) -, -C (R^one) (R²) -, -C (R^one)₂-,> C <, -Si (R^one)₂O- and -Si (R^one) (R²) O- are repeated, or two or more of their types are combined; or a mixed chain of them; structure X contains at the end of the structure X, a hydrogen atom or at least one kind of group selected from the group including -C (A)₃, -C (A)₂B, -C (A) (B)₂, -C (A)₂-C (R^one)₃, -C (R^one)₂A, -C (R^one)₃, -OSi (R^one)₃, -OSi (R^one)₂(R²), -Si (R^one)₃ and -Si (R^one)₂(R²);

where R^one and R², each independently represents a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, or a halogen atom; A and B each independently represent a substituent containing an oxygen atom or a nitrogen atom; when there is a set R^one, R², A and B for each structure X, they can be the same or different; and

where Y denotes a hydrophilic group having hydrophilicity, the group contains an atom selected from a hydrogen atom, a carbon atom, an oxygen atom, a nitrogen atom, a phosphorus atom or a sulfur atom; and when there is a plurality of Ys, they may be the same or different.

{0133}

<16>

The nonwoven fabric according to the above <15>, wherein the liquid film breaker or compound C1 is a compound containing a siloxane chain, in which the structures represented by any of the following Formulas (1) to (11) are randomly combined as specified above structures X, XY and YXY:

where, in Formulas (1) - (11), M ¹ , L ¹ , R ²¹ and R ²² denote the following monovalent or multivalent (divalent or having a higher valence) group; R ²³ and R ²⁴ denote the following monovalent or multivalent (divalent or higher valence) group or single bond;

M ¹ represents a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, a group containing a polyoxyalkylene group in combination therewith, an erythritol group, a xylitol group, a sorbitol group, a hydrophilic group having a plurality of hydroxy groups such as a glycerol group or an ethylene glycol group (hydrophilic formed by removing one hydrogen atom from a compound described above having a plurality of hydroxy groups such as erythritol), a hydroxy group, a carboxylic acid group, a mercapto group, an alkoxy group (the number of carbon atoms is preferably 1-20, for example, a methoxy group is preferred) , amino group, amide group, imino group, phenol group, sulfonic acid group, quaternary ammonium group, sulfobetaine group, hydroxysulfobetaine group, phosphobetaine group, imidazolium betaine group, carbobetaine group, epoxy group, carbinol group, (meth) acryl th group or functional group in combination with them; when M ¹ is a multivalent group, M ¹ is a group formed by further removing one or more hydrogen atoms from each of the groups or from a functional group as discussed above;

L ¹ is a linking group from an ether group, an amino group (the amino group used as L ¹ is represented by> NR ^C (R ^C is a hydrogen atom or a monovalent group)), an amide group, an ester group, a carbonyl group, or carbonate group;

R ²¹ , R ²² , R ²³ and R ²⁴ each independently represent an alkyl group (the number of carbon atoms is preferably from 1 to 20, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, a hexyl a group, a heptyl group, a 2-ethylhexyl group, a nonyl group or a decyl group is preferred), an alkoxy group (the number of carbon atoms is preferably from 1 to 20, for example, a methoxy group or an ethoxy group is preferred), an aryl group (the number of carbon atoms is preferably is from 6 to 20, for example, a phenyl group is preferred), a fluoroalkyl group, an aralkyl group, a hydrocarbon group in combination with them, or a halogen atom (for example, a fluorine atom is preferred); when R ²² and R ²³ represent a multivalent group, R ²² and R ²³ represent a multivalent hydrocarbon group formed by further removing one or more hydrogen or fluorine atoms from the above-described hydrocarbon group; and

when R ²² or R ²³ is bonded to M ¹ , specific examples of the group used as R ²² or R ²³ include, in addition to each of the groups, a hydrocarbon group or a halogen atom described above, an imino group used as R ³² ...

{0134}

<17>

The nonwoven fabric according to any of the above <11> to <16>, wherein the liquid film breaker or compound C1 contains an organically modified silicone of a silicone-based surfactant and contains at least one compound selected from the group containing amino modified silicone, epoxy modified silicone, carboxy modified silicone, diol modified silicone, carbinol modified silicone, (meth) acrylic modified silicone, mercapto modified silicone and phenol modified silicone, polyether modified silicone , methyl styryl modified silicone, long chain alkyl modified silicone, higher alkoxy ester modified silicone, higher alkoxy modified silicone, higher fatty acid modified silicone and fluorine modified silicone, polyether modified silicone, methyl styryl modified silicone , silicone, modified long chain alkyl, higher fatty acid ester modified silicone, higher alkoxy modified silicone, higher fatty acid modified silicone, and fluorine modified silicone.

{0135}

<18>

The nonwoven fabric according to any of the above <11> to <17>, wherein the liquid film breaker or compound C1 comprises a polyoxyalkylene modified silicone and wherein the polyoxyalkylene modified silicone is at least one silicone selected from the group, containing a compound represented by any of the following Formulas [I] - [IV]:

where R ³¹ represents an alkyl group (the number of carbon atoms is preferably from 1 to 20, for example, 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-ethylhexyl group, a nonyl group or decyl group is preferred); R ³² is a single bond or an alkylene group (the number of carbon atoms is preferably 1 to 20, for example, a methylene group, an ethylene group, a propylene group or a butylene group is preferred), and preferably an alkylene group; a plurality of R ³¹ and a plurality of R ³² may be each the same or different; M ¹¹ represents a group containing a polyoxyalkylene group, and a polyoxyalkylene group is preferred; specific examples of the above-described polyoxyalkylene groups include a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, or a material in which their constituent monomers are copolymerized; m and n each independently represent an integer of 1 or more; and the designation of these repeating units is defined separately in each of the formulas [I] to [IV], and they do not always represent the same whole numbers, and they may be different.

{0136}

<19>

The nonwoven fabric according to the above item <11> or <12>, where the spreading coefficient of the agent for breaking the liquid film, for a liquid having a surface tension of 50 mN / m, is greater than 0 mN / m, and the surface tension of the agent for breaking the liquid film, for a liquid having a surface tension of 50 mN / m is 20 mN / m or less.

{0137}

<20>

A nonwoven fabric containing a concave portion and a high density portion that is located at the bottom of the concave portion and has a fiber density higher than that of any other portion,

wherein the nonwoven fabric is divided into a high density portion and a non-high density portion other than a high density portion, and the nonwoven fabric contains the following C2 compound in the non-high density portion:

[Compound C2]

A compound having a spreading coefficient greater than 0 mN / m for a liquid having a surface tension of 50 mN / m and a tension at an interface with a liquid having a surface tension of 50 mN / m, 20 mN / m or less.

{0138}

<21>

The nonwoven fabric according to any of the above <11>, <12>, <19> and <20>, wherein the liquid film breaker or compound C2 comprises a compound having at least one kind of structure selected from the group, including the following structures Z, ZY and YZY:

where structure Z denotes a hydrocarbon chain having a structure in which any of the basic structures is repeated> C (A) - (C: carbon atom), -C (A) ₂ -, -C (A) (B) -,> C (A) -C (R ³ ) <,> C (R ³ ) -, -C (R ³ ) (R ⁴ ) -, -C (R ³ ) ₂ - and> C <or two or more of their types are combined ; structure Z has, at one of its ends, a hydrogen atom or at least one kind of a group selected from the group consisting of -C (A) ₃ , -C (A) ₂ B, -C (A) (B) _{2 ,} -C (A) ₂ -C (R ³ ) ₃ , -C (R ³ ) ₂ A -C (R ³ ) ₃ ;

where R³ and R^foureach independently represents a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, a fluoroalkyl group, an aralkyl group, a hydrocarbon group in combination with them, or a fluorine atom; A and B each independently represent a substituent containing an oxygen atom or a nitrogen atom; when the set R³, R^four, A or B, each included in the structure Z, they can be the same or different; and

where Y denotes a hydrophilic group having hydrophilicity, a hydrophilic group containing an atom selected from a hydrogen atom, a carbon atom, an oxygen atom, a nitrogen atom, a phosphorus atom and a sulfur atom; and when a plurality of Ys are present, they may be the same or different.

{0139}

<22>

The nonwoven fabric according to the above <21>, wherein the liquid film breaker or compound C2 is a compound in which structures represented by any of the following Formulas (12) to (25) are randomly combined as specific examples of structures Z, ZY and YZY:

where M ² , L ² , R ⁴¹ , R ⁴² and R ⁴³ denote the following further monovalent or multivalent (divalent or having a higher valence) groups;

where M ² denotes a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, a group containing a polyoxyalkylene group in combination with them, an erythritol group, a xylitol group, a sorbitol group, a hydrophilic group having a plurality of hydroxy groups such as a glycerol group or an ethylene glycol group, hydroxy , a carboxylic acid group, a mercapto group, an alkoxy group (the number of carbon atoms is preferably from 1 to 20, for example, a methoxy group is preferred), an amino group, an amide group, an imino group, a phenol group, a sulfonic acid group, a quaternary ammonium group, a sulfobetainic a group, a hydroxysulfobetaine group, a phosphobetaine group, an imidazolium betaine group, a carbobetaine group, an epoxy group, a carbinol group, a (meth) acryl group, or a functional group in combination with them;

where L ² denotes a linking group such as an ether group, amino group, amide group, ester group, carbonyl group, carbonate group, polyoxyethylene group, polyoxypropylene group, polyoxybutylene group or polyoxyalkylene group in combination with them;

where R ⁴¹ , R ⁴² and R ⁴³ each independently represent different substituents such as a hydrogen atom, an alkyl group (the number of carbon atoms is preferably from 1 to 20, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, nonyl group or decyl group is preferred), alkoxy group (the number of carbon atoms is preferably from 1 to 20, for example, methoxy group or ethoxy group is preferred) , an aryl group (the number of carbon atoms is preferably 6 to 20, for example, a phenyl group is preferred), a fluoroalkyl group, an aralkyl group, a hydrocarbon group in combination with them, or a halogen atom (for example, a fluorine atom is preferred);

where when R ⁴² is a multivalent group, R ⁴² is a group formed by further removing one or more hydrogen atoms from each of the above-described substituents; and

where at the end of the chemical bond described in each structure, any other structure can be arbitrarily attached or a hydrogen atom can be introduced.

{0140}

<23>

The nonwoven fabric according to any one of the above <11>, <12>, and <19> to <22>, wherein the liquid film breaker or C2 compound contains at least one compound selected from the group consisting of a polyoxyalkylene alkyl ( POA) an ether represented by any of the formulas in Formula [V]; and any compound of polyoxyalkylene glycol, steareth, behenet, PPG myristyl ether, PPG stearyl ether and PPG behenyl ether, which are represented by the following Formula [VI] and have a molecular weight of 1000 or more:

where L ²¹ represents a linking group such as an ether group, amino group, amide group, ester group, carbonyl group, carbonate group, polyoxyethylene group, polyoxypropylene group or polyoxybutylene group, or a polyoxyalkylene group in combination with them; R ⁵¹ represents various substituents such as hydrogen atom, methyl group, ethyl group, propyl group, isopropyl group, butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, nonyl group, decyl group, methoxy group, ethoxy a group, a phenyl group, a fluoroalkyl group, an aralkyl group, a hydrocarbon group combined with them, or a fluorine atom group, a fluoroalkyl group, an aralkyl group, a hydrocarbon group combined with them, or a fluorine atom; a, b, m and n each independently represent an integer of 1 or more; C _m H _n in this document denotes an alkyl group (n = 2m + 1) and C _a H _b denotes an alkylene group (a = 2b); these numbers of carbon atoms and these numbers of hydrogen atoms are each independently defined in each of formulas [V] and [VI], and they do not always represent the same integers, and they may be different; ʺMʺ in - (C _a H _b O) _m - is an integer of 1 or more; and the values of the repeating units are each independently defined in each of formulas [V] and [VI], and they do not always represent the same whole numbers, and they may be different.

{0141}

<24>

The nonwoven fabric according to any of the above <11>, <12>, and <19> to <22>, wherein the liquid film breaker or compound C2 comprises at least a compound selected from the group consisting of a fatty acid represented by by the following Formula [VII], a glycerol fatty acid ester and a pentaerythritol fatty acid ester represented by the following Formula [VIII-I] or [VIII-II], a partially esterified product of a glycerol fatty acid ester, a sorbitan fatty acid ester acid and pentaerythritol fatty acid ester represented by any of the following Formulas [IX], any of the Formulas in the following Formula [X], or any of the Formulas in the following Formula [XI], a compound having a sterol structure of the following Formulas [XII ], an alcohol represented by the following Formula [XIII], a fatty acid ester represented by the following Formula [XIV], and a wax represented by the following Formula [XV]:

where m and n, each independently represent an integer of 1 or more; C _m H _n in this document denotes a hydrocarbon group of the above-described fatty acid;

where m, m ', m ", n, n' and n", each independently represent an integer of 1 or more; a plurality of m or a plurality of n, each can be the same or different from each other; C _m H _n , C _m 'H _n ' and C _m ″ H _n ″ each, herein, denotes a hydrocarbon group of the above-described fatty acid;

where m and n, each independently represent an integer of 1 or more; a plurality of m or a plurality of n, each can be the same or different from each other; C _m H _n in this document denotes a hydrocarbon group of the above-described fatty acid;

where R ⁵² denotes having a straight chain or branched chain, or saturated or unsaturated hydrocarbon group (alkyl group, alkenyl group, alkynyl group or the like) containing 2 or more and 22 or less carbon atoms; specific examples include a 2-ethylhexyl group, a lauryl group, a myristyl group, a palmityl group, a stearyl group, a behenyl group, an oleyl group, and a linoleic group;

where m and n, each independently represent an integer of 1 or more; a plurality of m or a plurality of n, each can be the same or different from each other; C _m H _n in this document denotes a hydrocarbon group of the above-described fatty acid;

where m and n, each independently represent an integer of 1 or more; C _m H _n herein, a hydrocarbon group of the above alcohol;

where m and n, each independently represent an integer equal to 1 or more; the two parts of C _m H _n herein may be the same or different; C _m H _n in C _m H _n —COO— represents a hydrocarbon group of each fatty acid described above; C _m H _n in —COOC _m H _n represents a hydrocarbon group derived from an alcohol which forms an ester; and

where m and n are each independently an integer of 1 or greater.

{0142}

<25>

The nonwoven fabric according to any one of the above <11> to <24>, wherein the water solubility of the liquid film breaker, compound C1 or compound C2 is 0 g or more and 0.025 g or less, preferably 0.0025 g or less more preferably 0.0017 g or less, and even more preferably less than 0.0001 g; and 0 g or more, and preferably 1.0 x 10 ^-9 g or more.

<26>

The nonwoven fabric according to any one of the above <11> to <25>, wherein the surface tension of the liquid film breaker, C1 compound or C2 compound for a liquid having a surface tension of 50 mN / m is 20 mN / m or less, preferably 17 mN / m or less, more preferably 13 mN / m or less, even more preferably 10 mN / m or less, particularly preferably 9 mN / m or less, and even more preferably 1 mN / m or less; and preferably greater than 0 mN / m.

<27>

The nonwoven fabric according to any of the above <11> to <26>, wherein the surface tension of the liquid film breaker, C1 compound or C2 compound is 32 mN / m or less, preferably 30 mN / m or less, more preferably 25 mN / m or less, and particularly preferably 22 mN / m or less; and preferably 1 nM / m or more.

{0143}

<28>

A nonwoven fabric according to any one of the above <11> to <27>, wherein the liquid film breaker compound C1 or compound C2 is located at least at a portion of the points where the fibers are intertwined with each other, or thermally fused dots in the non-woven high-density portion.

<29>

The nonwoven fabric according to any of the above <11> to <28>, wherein the content of the liquid film breaker compound C1 or compound C2 in the high density portion is preferably 10 mass% or less, more preferably 4 mass% or less , even more preferably 2% by mass or less, and particularly preferably 0% by mass, in terms of their proportion with respect to the content of the liquid or compound film breaker in the non-high density portion.

<30>

The nonwoven fabric according to any of the above <11> to <29>, wherein the liquid film breaker compound C1 or compound C2 is located only in the non-high density portion.

{0144}

<31>

The nonwoven fabric according to any one of the above <11> to <30>, wherein the high density portion is a portion in which the fibers are consolidated by compressing the nonwoven in the thickness direction by embossing.

<32>

A nonwoven fabric according to any of the above <11> to <31>, wherein the high density portion is a portion in which the fibers are compressed to a flattened shape or thermally melt in a state in which the distance between the fibers becomes much smaller than in any other part.

<33>

The nonwoven fabric according to any one of the above <11> to <32>, wherein the melting point of the liquid film breaker, C1 compound or C2 compound is preferably 40 ° C or less, and more preferably 35 ° C or less; and preferably -220 ° C or more, and more preferably -180 ° C or more.

<34>

A nonwoven fabric according to any of the above <11> to <33>, wherein the fiber contact angle for the deionized water in the high density portion is preferably 90 ° or less, more preferably 80 ° or less, even more preferably 70 ° or less and particularly preferably 65 ° or less.

<35>

The nonwoven fabric according to any of the above <11> to <34>, further comprising an anionic surfactant of the phosphoric acid ester type in addition to a liquid film breaker, Compound C1 or Compound C2.

<36>

The nonwoven fabric according to any of the above <11> to <35>, wherein the liquid film breaker Compound C1 or Compound C2 is preferably a compound having a weight average molecular weight of 500 or more and a weight average molecular weight, more preferably is 1000 or more, even more preferably 1500 or more, and particularly preferably 2000 or more; preferably 50,000 or less, more preferably 20,000 or less, and even more preferably 10,000 or less.

{0145}

<37>

The topsheet of a sanitary napkin, baby diaper, or adult incontinence diaper using the nonwoven fabric of any of the above <11> to <36>.

{0146}

<38>

An absorbent article containing a nonwoven material according to any of the above items <11> to <36> or a topsheet according to the above item <37>.

{0147}

<39>

A method for producing a nonwoven fabric, including the step of applying a liquid coating to a nonwoven fabric from raw materials using a flexographic printing system,

where the liquid coating contains the following compound C1 and has a viscosity of 25 cps or more, preferably 80 cps or more, and more preferably 150 cps or more; and preferably 10,000 cps or less, more preferably 5,000 cps or less, and even more preferably 1,000 cps or less, and

where the raw material nonwoven has a concave part and a high density part,

and the high density portion is located at the bottom of the concave portion and has a higher fiber density than any other portion:

[Connection C1]

A compound having a spreading coefficient of 15 mN / m or more for a liquid having a surface tension of 50 mN / m.

{0148}

<40>

A method for producing a nonwoven fabric, including the step of applying a liquid coating to a nonwoven fabric from raw materials using a flexographic printing system,

where the liquid coating contains the following compound C2 and has a viscosity of 25 cps or more, preferably 80 cps or more, and more preferably 150 cps or more; and preferably 10,000 cps or less, more preferably 5,000 cps or less, and even more preferably 1,000 cps or less, and

where the raw material nonwoven has a concave part and a high density part,

and the high density portion is located at the bottom of the concave portion and has a higher fiber density than any other portion:

[Compound C2]

A compound having a spreading coefficient greater than 0 mN / m for a liquid having a surface tension of 50 mN / m and a tension at an interface with a liquid having a surface tension of 50 mN / m, 20 mN / m or less.

{0149}

<41>

The method for producing a nonwoven fabric according to the above <39> or <40>, wherein the water solubility of the C1 compound or the C2 compound is 0 g or more and 0.025 g or less.

{0150}

<42>

The method for producing a nonwoven fabric according to any one of the above <39> to <41>, wherein the hardness of the flexographic plate used in coating with the flexographic printing system is 62 ° or more.

<43>

The method for producing a nonwoven fabric according to any one of the above <39> to <42>, wherein the gap between the flexographic plate and the substrate roller used in coating with the flexographic printing system is -750 μm or more and 750 μm or less, preferably , -550 μm or more, and more preferably, -400 μm or more; preferably 550 µm or less, and more preferably 400 µm or less.

<44>

The method for producing a nonwoven fabric according to any one of the above <39> to <43>, wherein the volume of the anilox roll used in coating with the flexographic printing system is 1 cm ³ / m ² or more and 30 cm ³ / m ^2, or less, preferably 3 cm ³ / m ² or more, and more preferably 5 cm ³ / m ² or more;

and preferably 25 cm ³ / m ² or less, and more preferably 20 cm ³ / m ² or less.

Examples of

{0151}

Below, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. In addition, both terms "part" and "%" in the Examples refer to mass, unless otherwise noted. In addition, as described above, the spreading coefficient, interface tension, surface tension and solubility in water are values to be measured in an ambient range at 25 ° C and 65% relative humidity (RH).

The surface tension, water solubility and surface tension of the liquid film breaker in the Examples described below were measured using the measurement method discussed above.

{0152}

(Example 1)

The nonwoven fabric from the starting materials having the convex-concave structure shown in Fig. 5 is obtained by the above method. Fibers without heat shrinkage and thermally fused fibers having a fineness of 1.2 dtex are used in the upper layer (1A side layer of the first surface), and heat shrinkable fibers having a fineness of 2.3 dtex are used in the lower layer (1B side layer of the second surface) ... The distance between the fibers in the upper layer is 80 μm, and the distance between the fibers in the lower layer is 60 μm. In addition, the basis weight of the nonwoven fabric is 74 g / m ² . The area ratio of the high density portion relative to the area of the nonwoven fabric is 45%.

Prior to the preparation as described above, a polyoxyethylene (POE) modified dimethyl silicone (KF-6015, manufactured by Shin-Etsu Chemical Co., Ltd.), a liquid film breaking agent in which X in the XY structure is formed from a dimethyl silicone chain, consisting of -Si (CH ₃ ) ₂ O-, Y is formed from the POE chain consisting of - (C ₂ H ₄ O) -, the final group of the POE chain is a methyl group (CH ₃ ), the modification ratio is 20%, the amount added moles of polyoxyethylene is 3 and the weight average molecular weight is 4000, directly prepared as a liquid coating. That is, a liquid coating is prepared from a 100% liquid film breaker. The viscosity of the liquid coating is measured using the measurement method discussed above and is 163 cP.

A liquid coating was applied to a surface having a convex-concave structure in the raw nonwoven fabric using the flexographic printing system discussed above, the resulting fabric was dried, and the nonwoven fabric S1 was sampled in Example 1. The content fraction (OPU ) agent for breaking the liquid film relative to the weight of the fibers of the nonwoven fabric is generally set at 4.5% of the mass. In addition, the coating conditions are as follows.

Flexo plate hardness: 68 °

Gap between flexo plate and liner roller: 740 μm

The volume of the anilox roll: 18 cm ³ / m ² (line 140 lpi

Coating speed: 80 m / min

In the high density portion at the bottom of the concave portion of the nonwoven fabric sample S1, the fiber spacing is 8.8 µm and the contact angle for the high density portion is 79.4 °. The contact angle for the non-high density portion is 100.0 °.

Polyoxyethylene (POE) -modified dimethylsilicone as an agent for breaking the liquid film has a surface tension of 21.0 mN / m and a water solubility of less than 0.0001 g. In addition, the spreading coefficient of polyoxyethylene (POE) -modified dimethylsilicone for liquid, having a surface tension of 50 mN / m is 28.8 mN / m, and its the surface tension for a liquid having a surface tension of 50 mN / m is 0.2 mN / m. These numerical values are measured using the measurement method discussed above. Sometimes, a solution is used as a liquid having a surface tension of 50 mN / m2, and the solution is prepared by adding, using a micropipette (ACURA 825, manufactured by Socorex Isba SA), to 100 g of deionized water, 3.75 μl of polyoxyethylene sorbitan monolaurate (commercial the name "Leodol Super TW-L120," manufactured by Kao Corporation), which is a nonionic surfactant, and set the surface tension at 50 ± 1 mN / m. In addition, the solubility in water is measured by adding the agent at 0.0001 g. As a result, a sample that is observed to not dissolve even at 0.0001 g is taken as "less than 0.0001 g", and a sample that is observed, dissolves at 0.0001 g, but does not dissolve at 0.0002 g, is taken as ʺ0.0001 gʺ. Numerical values other than those indicated above are measured using the same methods.

{0153}

(Example 2)

A nonwoven sample S2 in Example 2 was prepared in the same manner as in Example 1, except that the proportion (OPU) of the liquid film breaker relative to the weight of the fibers of the nonwoven fabric as a whole was set at 0.4% by weight, and the application conditions coatings change as described below.

Flexo plate hardness: 62 °

Gap between flexo plate and liner roller: 397 μm

Anilox roll volume: 1.3 cm ³ / m ² (number of lines: 1800 lines per inch

Coating speed: 30 m / min

In the high density portion at the bottom of the concave portion of the nonwoven fabric sample S2, the fiber spacing is 8.8 µm, and the contact angle for the high density portion is 81.2 °. The contact angle for the non-high density portion is 100.0 °.

{0154}

(Example 3)

The nonwoven fabric sample S3 in Example 3 was prepared in the same manner as in Example 1, except that the proportion (OPU) of the liquid film breaker relative to the weight of the fibers of the nonwoven fabric as a whole was set at 8.0% by weight, and the application conditions coatings change as described below.

Flexo plate hardness: 62 °

Gap between flexo plate and liner roller: 740 μm

Anilox roll volume: 18 cm ³ / m ² (lines: 140 lines per inch

Coating speed: 80 m / min

In the high density portion at the bottom of the concave portion of the nonwoven fabric sample S3, the fiber spacing is 8.8 µm, and the contact angle for the high density portion is 77.8 °. The contact angle for the non-high density portion is 100.0 °.

{0155}

(Example 4)

Nonwoven fabric sample S4 in Example 4 was prepared in the same manner as in Example 1, except that a dilute solution obtained by mixing the liquid film breaker used in Example 1 and ethanol as a solvent in a ratio of 75:25, used as a liquid coating. The viscosity of the liquid coating is measured using the measurement method discussed above and is 26.2 cps. The proportion (OPU) of the liquid film breaker relative to the weight of the fibers of the nonwoven fabric as a whole in the nonwoven fabric sample S4 is set at 5.9% by weight.

In the high density portion at the bottom of the concave portion of the nonwoven fabric sample S4, the fiber spacing is 8.8 µm and the contact angle for the high density portion is 77.9 °. The contact angle for the non-high density portion is 100.0 °.

{0156}

(Example 5)

Nonwoven fabric sample S5 in Example 5 was prepared in the same manner as in Example 1, except that a dilute solution obtained by mixing the liquid film breaker used in Example 1 and ethanol as a solvent in a ratio of 90:10, used as a liquid coating. The viscosity of the liquid coating is measured by the measurement method discussed above and is 62.8 cps. The proportion (OPU) of the liquid film breaker relative to the weight of the fibers of the nonwoven fabric as a whole in the nonwoven fabric sample S5 is set at 6.7% by weight.

In the high density portion in the lower portion of the concave portion of the nonwoven fabric sample S5, the fiber spacing is 8.8 µm and the contact angle for the high density portion is 73.9 °. The contact angle for the non-high density portion is 100.0 °.

{0157}

(Example 6)

Nonwoven fabric sample S6 in Example 6 was prepared in the same manner as in Example 1, except that a dilute solution obtained by mixing the liquid film breaker used in Example 1 and ethanol as a solvent in a ratio of 95: 5, used as a liquid coating. The viscosity of the liquid coating is measured using the measurement method discussed above and is 101 cps. The proportion (OPU) of the liquid film breaker relative to the weight of the fibers of the nonwoven fabric as a whole in the nonwoven fabric sample S6 is set at 5.9% by weight.

In the high density portion at the bottom of the concave portion of the nonwoven fabric sample S6, the fiber spacing is 8.8 µm, and the contact angle for the high density portion is 86.7 °. The contact angle for the non-high density portion is 100.0 °.

{0158}

(Example 7)

The nonwoven fabric sample S7 in Example 7 was prepared in the same manner as in Example 3, except: the use of polyoxypropylene (POP ₃ ) -modified dimethylsilicone as an agent for breaking the liquid film, which should be a liquid coating (obtained by performing a hydrosilylation reaction between silicone oil and a hydrocarbon compound), in which X in the XY structure is formed from a dimethylsilicone chain consisting of -Si (CH ₃ ) ₂ O-, Y is formed from a POP chain consisting of - (C ₃ H ₆ O) -, the final the POP group of the chain is a methyl group (CH ₃ ), the modification ratio is 20%, the number of added moles of polyoxypropylene is 3 and the weight average molecular weight is 4150.

Surface tension: 21.0 mN / m

Solubility in water: less than 0.0001g

Spread coefficient for a liquid having a surface tension of 50 mN / m: 25.4 mN / m

Tension at the interface with a liquid having a surface tension of 50 mN / m: 3.6 mN / m

The four numerical values are measured using the same method as in Example 1. The viscosity of the liquid coating is measured using the above measurement method and is 81 cP. The proportion (OPU) of the liquid film breaker relative to the weight of the fibers of the nonwoven fabric as a whole in the nonwoven fabric sample S7 is set at 6.8% by weight.

In the high density portion at the bottom of the concave portion of the nonwoven fabric sample S7, the fiber spacing is 8.8 µm, and the contact angle for the high density portion is 80.6 °. The contact angle for the non-high density portion is 96.2 °.

{0159}

(Example 8)

The nonwoven fabric sample S8 in Example 8 was prepared in the same manner as in Example 3, except: using, as a liquid film breaker, which should be a liquid coating, liquid isoparaffin (Luvitol Lite, manufactured by BASF Japan) having a weighted average molecular weight weight 450.

Surface tension: 27.0 mN / m

Solubility in water: less than 0.0001g

Spread coefficient for a liquid having a surface tension of 50 mN / m: 14.5 mN / m

Tension at the interface with a liquid having a surface tension of 50 mN / m: 8.5 mN / m

Four numerical values are measured using the same method as in Example 1. The viscosity of the liquid coating is measured using the above measurement method and is 31.1 cP. The proportion (OPU) of the liquid film breaker relative to the mass of the fibers of the nonwoven fabric as a whole in the nonwoven fabric sample S8 is set at 3.9 mass%.

In the high density portion at the bottom of the concave portion of the nonwoven fabric sample S8, the fiber spacing is 8.8 µm and the contact angle for the high density portion is 87.9 °. The contact angle for the non-high density portion is 95.3 °.

{0160}

(Example 9)

Nonwoven fabric sample S9 in Example 9 was prepared in the same manner as in Example 3, except that a dilute solution obtained by mixing the liquid film breaker used in Example 1 and ethanol as a solvent in a ratio of 50:50, used as a liquid coating.

The viscosity of the liquid coating is measured using the measurement method discussed above and is 6.93 cps. The proportion (OPU) of the liquid film breaker relative to the weight of the fibers of the nonwoven fabric as a whole in the nonwoven fabric sample S9 is set at 6.4% by weight.

In the high density portion at the bottom of the concave portion of the nonwoven fabric sample S9, the fiber spacing is 8.8 µm, and the contact angle for the high density portion is 91.0 °. The contact angle for the non-high density portion is 100.0 °.

{0161}

(Example 10)

Nonwoven fabric sample S10 in Example 10 was prepared in the same manner as in Example 3, except: using caprylic / capric triglyceride (COCONARD MT, manufactured by Kao Corporation) as a liquid film breaker, which should be a liquid coating, where Z in the structure ZY is * -O-CH (CH ₂ O- *) ₂ (* is a linking part), Y is formed from a hydrocarbon chain C ₈ H ₁₅ O- or C ₁₀ H ₁₉ O-, fatty acid composition consists of 82% caprylic acid and 18% capric acid and has a weight average molecular weight of 550.

Surface tension: 28.9 mN / m

Solubility in water: less than 0.0001g

Spread coefficient for a liquid having a surface tension of 50 mN / m: 8.8 mN / m

Tension at the interface with a liquid having a surface tension of 50 mN / m: 12.3 mN / m

Four numerical values are measured using the same method as in Example 1. The viscosity of the liquid coating is measured using the above measurement method and is 24.1 cP. The proportion (OPU) of the liquid film breaker relative to the weight of the fibers of the nonwoven fabric as a whole in the nonwoven fabric sample S11 is set at 4.3% by weight.

In the high density portion at the bottom of the concave portion of the nonwoven fabric sample S10, the fiber spacing is 8.8 µm and the contact angle for the high density portion is 98.8 °. The contact angle for the non-high density portion is 94.4 °.

{0162}

(Example 11)

The sample of nonwoven fabric in Example 11 was prepared in the same manner as in Example 3, except: using the following material as a liquid film breaking agent, that the proportion (OPU) of the liquid film breaking agent relative to the fiber weight was set at 12.8 % mass.

<Liquid film breaker>

Liquid paraffin wax (manufactured by KISHIDA CHEMICAL Co., Ltd.) having a weight average molecular weight of 300.

Surface tension: 30.6 mN / m

Solubility in water: less than 0.0001g

Spread coefficient for a liquid having a surface tension of 50 mN / m: 9.9 mN / m

Tension at the interface with a liquid having a surface tension of 50 mN / m: 9.5 mN / m

(Four numerical values are measured using the same method as in Example 1)

The viscosity of the liquid coating is measured using the measurement method discussed above and is 205.3 cps. In the high density portion at the bottom of the concave portion in the nonwoven sample S11, the fiber spacing is 8.8 µm and the contact angle in the high density portion is 82.3 °. The contact angle in the non-high density portion is 109.3 °.

{0163}

(Example 12)

A nonwoven fabric is obtained in the same way as in Example 3, except: epoxy modified dimethyl silicone (KF-101, manufactured by Shin-Etsu Chemical Co., Ltd.), in which X in the XY structure is formed from a dimethyl silicone chain consisting of -Si (CH₃)₂O-, Y is formed from an epoxy group consisting of - (RC₂H₃O) -, the modification ratio is 32%, and the weight average molecular weight is 35800; and the proportion (OPU) of the liquid film breaker relative to the weight of the fibers are set at 3.6% by mass. The resulting nonwoven fabric is taken as a sample from Example 12.

Epoxy-modified dimethylsilicone has a surface tension of 21.0 mN / m and a water solubility of less than 0.0001 g. In addition, the spreading coefficient of epoxy-modified dimethylsilicone for a liquid having a surface tension of 50 mN / m is 26.0 mN. / m, and its the surface tension for a liquid having a surface tension of 50 mN / m is 3.0 mN / m. These numerical values are measured using the same method as in Example 1.

The viscosity of the liquid coating is measured using the measurement method discussed above and is 1500 cP. In the high density portion at the bottom of the concave portion in the nonwoven fabric sample S12, the fiber spacing is 8.8 µm and the contact angle in the high density portion is 80.8 °. The contact angle in the non-high density portion is 91.8 °.

{0164}

(Example 13)

A nonwoven fabric was prepared in the same manner as in Example 3, except: using a diol-modified dimethyl silicone at one end (X-22-176DX, manufactured by Shin-Etsu Chemical Co., Ltd.), in which X in structure XY is a dimethylsilicone chain composed of -Si (CH ₃ ) ₂ O- and Y is a diol having a plurality of hydroxyl groups consisting of - (OH) -, the ratio the modification is 1.2% and the weight average molecular weight is 6190; and the proportion (OPU) of the liquid film breaker relative to the weight of the fibers is set at 6.3% by mass. The resulting nonwoven fabric was taken as a sample from Example 13.

Diol-modified dimethyl silicone at one end has a surface tension of 21.0 mN / m and a water solubility of less than 0.0001 g. In addition, the spread coefficient of diol-modified dimethyl silicone at one end for a liquid having a surface tension of 50 mN / m, is 27.1 mN / m, and its the surface tension for a liquid having a surface tension of 50 mN / m is 1.9 mN / m. These numerical values are measured using the same method as in Example 1.

The viscosity of the liquid coating is measured using the measurement method discussed above and is 130 cP. In the high density portion at the bottom of the concave portion in the nonwoven fabric sample S13, the fiber spacing is 8.8 µm and the contact angle in the high density portion is 78.8 °. The contact angle in the non-high density portion is 100.8 °.

{0165}

(Comparative example 1)

The nonwoven raw material used in Example 1 was used directly as the nonwoven fabric C1 sample in Comparative example 1. Accordingly, the liquid surface disintegrant was not introduced into the nonwoven fabric C1 sample in Comparative example 1. In addition, a portion of the high the density at the bottom of the concave portion in the nonwoven sample C1, the fiber spacing is 8.8 µm, and the contact angles in the high density portion and the non-high density portion are 80.0 °.

{0166}

(Assessment)

The evaluation described below was carried out using a sanitary napkin for evaluation, which was obtained by removing the topsheet from a sanitary napkin (LAURIER F Shiawase Suhada, 30 cm, manufactured by Kao Corporation in 2014) as one example of an absorbent article, and laminating it instead. a nonwoven sample (hereinafter referred to as a nonwoven sample), and fixing its periphery.

{0167}

(Liquid volume in high density part (embossed part))

On the surface of each sanitary napkin for evaluation, an acrylic plate having a penetration hole with an inner diameter of 1 cm is applied, and a predetermined load of 100 Pa is applied to the sanitary napkin. Under such a load, 6.0 g of artificial blood (prepared in the same manner as the material used in the measurement of the residual fluid content described below) of the corresponding menstrual blood is poured onto it through the penetration hole of the acrylic plate. 60 seconds after pouring 6.0 g of artificial blood on it, the acrylic plate is removed from it and the sanitary napkin is photographed. Then, the amount (N1) of high density parts present in the ranges in which the liquid diffuses is counted using a photograph. Then, the number (N2) of the high density portions in which the liquid volumes are formed is counted to determine the probability (N2 / N1 × 100) of the formation of the liquid volume in the high density portion. The operation described above is performed three times, and the average of three times is taken as the probability of a liquid volume forming in the high density portion. The volume of liquid in the high density portion becomes a factor in wetting the user's skin, and therefore, when the likelihood of the formation of the liquid volume is less, such a case gives better results.

{0168}

(The proportion of the liquid film breaker in the high density part 8 relative to the liquid film breaker content in the non-high density part 9)

From the ratio (W1 × content fraction / 100) between the weight of the nonwoven fabric (W1) and the proportion of the liquid film breaking agent relative to the fiber weight of the nonwoven fabric as a whole, the content (W3) of the liquid breaking agent contained in the nonwoven fabric as a whole is calculated. ... The W4 content (W3 × Q1 / 100) is determined from the content (W3) and the area ratio (Q1) of the high density portion when the agent is applied as a coating to all of the high density portions. Further, from the ratio between the content (W4) when the agent is coated on all of the high density portions and the probability T1 of the formation of a liquid volume in the high density portion (embossed portion) determined as described above, the W5 content (W4 × T1 / 100) in the real part of high density. Then, the content of W6 (W3-W5) in the non-high density portion and the content of W7 (W5 / W6 × 100) of the disintegrant contained in the high density portion are determined with respect to the amount of the disintegrant contained in the portion, not having a high density, and the resulting value is taken as a proportion of the amount of the disintegrant contained in the high density portion relative to the amount of the disintegrating agent contained in the non-high density portion. If the content of the disintegrant in the high density portion is large, such a case becomes a hydrophobizing factor, and therefore, when the proportion of the content decreases, the likelihood of the formation of a liquid volume decreases.

{0169}

(The amount of residual liquid in the nonwoven sample (top sheet))

On the surface of each sanitary napkin for evaluation, an acrylic plate having a penetration hole with an inner diameter of 1 cm is applied and a predetermined load of 100 Pa is applied to the sanitary napkin. Under this load, 6.0 g of artificial blood (prepared by adjusting the viscosity of defibrinated horse blood (manufactured by NIPPON BIO-TEST LABORATORIES INC.) To 8.0 cP, corresponding to menstrual blood), is poured onto it through the penetration hole of the acrylic plate. to this, the defibrinated horse blood used is adjusted in advance with a TVB-10 Viscometer (manufactured by Toki Sangyo Co., Ltd.) under conditions of 30 rpm.If the defibrinated horse blood is allowed to stand, the high viscosity portion (red blood cells or something the like) precipitates and the low viscosity part (plasma) remains as the supernatant. The mixing ratio in parts is set at 8.0 cP. 60 seconds after pouring a total of 6.0 g of artificial blood onto it, the acrylic plate is removed from it. Then measure the mass (W2) of the nonwoven sample, calculate the difference (W2-W1) with the mass (W1) of the nonwoven sample before pouring artificial blood, the mass of which is measured in advance. The operation described above is repeated 3 times, and the average of the 3 operations is taken as the amount of residual liquid (mg). The amount of residual liquid serves as an indication of how much the user's skin is wetted, and when the amount of residual liquid is lower, better results are obtained.

{0170}

The results of each evaluation with respect to Examples and Comparative Examples are shown in the following Tables 1 and 2. In addition, the notation ʺ-in the following Tables means that the agent shown in the item title is not used, or the result has no applicable meaning in this paragraph, or something similar.

{0171}

Table 1

Example 1 Example 2 Example 3 Example 4 Liquid coating: liquid film breaker or dilute solution POE3-modified silicone (Mw: 4000) POE3-modified silicone (Mw: 4000) POE3-modified silicone (Mw: 4000) Diluted solution of POE3-modified silicone (Mw: 4000) (EC: 75%) Viscosity of a liquid coating (agent for breaking the liquid film or its diluted solution) (cP) 163 163 163 26.2 The proportion of the content of the agent for breaking the liquid film in relation to the mass of the fiber (% mass) 4.5 0,4 8.0 5.9 The spreading coefficient of an agent for breaking a liquid film, for a liquid having a surface tension of 50 mN / m, (mN / m) 28.8 28.8 28.8 28.8 Surface tension of liquid film breaking agent (mN / m) 21.0 21.0 21.0 21.0 Tension at the interface of an agent for breaking a liquid-liquid film having a surface tension of 50 mN / m, (mN / m) 0.2 0.2 0.2 0.2 Water solubility of liquid film breaker (g) <0.0001 <0.0001 <0.0001 <0.0001 Contact angle for high density part (degrees) 79.4 81.2 77.8 77.9 Contact angle for non-high density part (degrees) 100.0 100.0 100.0 100.0 Probabilities of formation of a volume of liquid in a high density part (%) 0.0 1.6 15.6 8.6 The proportion of the amount of the liquid film breaking agent contained in the high density portion relative to the amount of the liquid film breaking agent contained in the non-high density portion (mass%) 0.0 0.7 7.6 4.0 Residual liquid amount in nonwoven sample (top sheet) (mg) 60 67 83 67

“Mw” stands for molecular weight. "EC" stands for effective ingredient.

Table 1 (continued)

Example 5 Example 6 Example 7 Liquid coating: liquid film breaker or dilute solution Diluted solution of POE3-modified silicone (Mw: 4000) (EC: 90%) Diluted solution of POE3-modified silicone (Mw: 4000) (EC: 95%) POP3-modified silicone (Mw: 4150) Viscosity of a liquid coating (agent for breaking the liquid film or its diluted solution) (cP) 62.8 101 81 The proportion of the content of the agent for breaking the liquid film in relation to the mass of the fiber (% mass) 6,7 5.9 6.8 The spreading coefficient of an agent for breaking a liquid film, for a liquid having a surface tension of 50 mN / m, (mN / m) 28.8 28.8 25.4 Surface tension of liquid film breaking agent (mN / m) 21.0 21.0 21.0 Tension at the interface of an agent for breaking a liquid-liquid film having a surface tension of 50 mN / m, (mN / m) 0.2 0.2 3.6 Water solubility of liquid film breaker (g) <0.0001 <0.0001 <0.0001 Contact angle for high density part (degrees) 73.9 86.7 80.6 Contact angle for non-high density part (degrees) 100.0 100.0 96.2 Probabilities of formation of a volume of liquid in a part of high density (%) 19.6 17.6 2.2 The proportion of the amount of the liquid film breaking agent contained in the high density portion with respect to the amount of the liquid film breaking agent contained in the non-high density portion
(% mass) 9,7 8.6 1.0 Residual liquid amount in nonwoven sample (top sheet) (mg) 84 78 77

“Mw” stands for molecular weight. "EC" stands for effective ingredient.

{0172}

Table 2 (Continuation of Table 1)

Example 8 Example 9 Example 10 Example 11 Liquid coating: liquid film breaker or dilute solution Liquid isoparaffin (Mw: 450) Diluted solution
POE-modified silicone (Mw: 4000) (EC: 50%) Caprylic / Capric Triglyceride (Mw: 550) Liquid paraffin (Mw: 300) Viscosity of a liquid coating (agent for breaking the liquid film or its diluted solution) (cP) 31.1 6.93 24.1 205.3 The proportion of the content of the agent for breaking the liquid film in relation to the mass of the fiber (% mass) 3.9 6.4 4.3 12.8 The spreading coefficient of an agent for breaking a liquid film, for a liquid having a surface tension of 50 mN / m, (mN / m) 14.5 28.8 8.8 9.9 Surface tension of liquid film breaking agent (mN / m) 27.0 21.0 28.9 30.6 Tension at the interface of an agent for breaking a liquid-liquid film having a surface tension of 50 mN / m, (mN / m) 8.5 0.2 12.3 9.5 Water solubility of liquid film breaker (g) <0.0001 <0.0001 <0.0001 <0.0001 Contact angle for high density part (degrees) 87.9 91.0 98.8 82.3 Contact angle for non-high density part (degrees) 95.3 100.0 94.4 109.3 Probabilities of formation of a volume of liquid in a part of high density (%) 4.4 37.6 41.6 7.0 The proportion of the amount of the liquid film breaking agent contained in the high density portion with respect to the amount of the liquid film breaking agent contained in the non-high density portion
(% mass) 2.0 20.4 23.0 3.3 Residual liquid amount in nonwoven sample (top sheet) (mg) 82 114 127 128

“Mw” stands for molecular weight. "EC" stands for effective ingredient.

Table 2 (Continuation of Table 1) (continued)

Example 12 Example 13 Comparative example 1 Liquid coating: liquid film breaker or dilute solution Epoxy modified silicone (Mw: 35800) Diol-modified silicone (Mw: 6190) - Viscosity of a liquid coating (agent for breaking the liquid film or its diluted solution) (cP) 1500 130 - The proportion of the content of the agent for breaking the liquid film in relation to the mass of the fiber (% mass) 3.6 6.3 - The spreading coefficient of an agent for breaking a liquid film, for a liquid having a surface tension of 50 mN / m, (mN / m) 26.0 27.1 - Surface tension of liquid film breaking agent (mN / m) 21.0 21.0 - Tension at the interface of an agent for breaking a liquid-liquid film having a surface tension of 50 mN / m, (mN / m) 3.0 1.9 - water solubility of the liquid film breaker (g) <0.0001 <0.0001 - Contact angle for high density part (degrees) 80.8 78.8 80.0 Contact angle for non-high density part (degrees) 91.8 100.8 80.0 Probabilities of formation of a volume of liquid in a part of high density (%) 10.4 12.0 0.0 The proportion of the amount of the liquid film breaking agent contained in the high density portion relative to the amount of the liquid film breaking agent contained in the non-high density portion (mass%) 4.9 5.7 - Residual liquid amount in nonwoven sample (top sheet) (mg) 121 97 280

{0173}

As shown in Tables 1 and 2, the nonwoven sample in Comparative Example 1 does not contain a liquid film breaker, and for this reason, the amount of residual liquid is twice or more than that in the nonwoven sample in each Example. In contrast, the nonwoven fabric sample in each Example is formed from a nonwoven fabric containing a liquid film breaking agent and containing a liquid film breaking agent at zero or suppressed content in the high density portion, and for this reason, the liquid volume in the high density is eliminated or reduced, and the amount of liquid remaining in the nonwoven fabric can be reduced. Specifically, in the nonwoven fabric sample in Example 1, the high density portion does not contain an agent for breaking the liquid film, and for this reason, the likelihood of forming a liquid volume in the high density portion is zero and the amount of residual liquid is the least.

In addition, with respect to Examples 9 and 10, in which the viscosity of the liquid film breaker or dilute solution thereof applied to the nonwoven fabric from the raw materials is less than 25 cP, Examples 1-8, in which their viscosity is 25 cP or more give a lower proportion of the liquid film breaker in the high density portion and a lower contact angle in the obtained nonwoven samples. As a result, the likelihood of the formation of liquid volume in the high density portion in the obtained nonwoven fabric and the amount of residual liquid in the topsheet are suppressed in Examples 1 to 8 to a lower level than in Examples 9 and 10. In addition, the viscosity is higher and the proportion of the agent for the liquid film breaks down in the high density portion, and the contact angle is also smaller in Examples 11-13 than in Examples 9 and 10, and the likelihood of liquid volume formation in the high density portion in the resulting nonwoven fabric is suppressed to a lower level.

{0174}

Describing the present invention as related to the present embodiments, aspects and Examples, the authors believe that the present invention is not limited to any details of the description, unless otherwise indicated, but rather should be considered broadly within its spirit and scope according to the appended claims. ...

{0175}

This application claims priority from Patent Application No. 2016-109601 filed in Japan on May 31, 2016, which is incorporated herein by reference in its entirety.

Description of symbols

{0176}

1 Fiber

2 Film of liquid

3 Agent for breaking liquid film

5, 10, 20, 30 Non-woven fabric

6 Concave part

7 Concave part of the bottom

8 Part of high density fibers

9 Part without high fiber density

Claims (66)

1. A method of producing a nonwoven fabric containing at least one type of fibers selected from sheath-core hot-melt composite fibers, thermally elongated fibers, thermally non-extensible fibers, heat-shrinkable fibers, fibers without thermal shrinkage, three-dimensionally twisted fibers, as constituent fibers, curled fibers and hollow fibers, including the step of liquid coating the nonwoven fabric from the starting materials using a flexographic printing system, where the liquid coating contains an agent for breaking the liquid film and has a viscosity of 25 cP or more, and where the raw material nonwoven has a concave part and a high density part, and the high density portion is located at the bottom of the concave portion and has a fiber density higher than that of any other portion; where the agent for breaking the film is: at least one kind of compound selected from organically modified silicone, polyhydric alcohol fatty acid ester and wax selected from ceresin, paraffin, petrolatum, mineral oil and liquid isoparaffin and represented by the following Formula [XV]; and has a spreading coefficient of 15 mN / m or more for a liquid having a surface tension of 50 mN / m, or has a spreading coefficient greater than 0 mN / m for a liquid having a surface tension of 50 mN / m and a tension of 20 mN / m or less at an interface with a liquid having a surface tension of 50 mN / m;

2. A method of producing a nonwoven fabric containing at least one type of fibers selected from sheath-core hot melt composite fibers, thermally extendable fibers, thermally non-extensible fibers, heat shrinkable fibers, fibers without thermal shrinkage, three-dimensionally twisted fibers, as constituent fibers, curled fibers and hollow fibers, including the step of liquid coating the nonwoven fabric from the starting materials using a flexographic printing system, where the liquid coating contains the following compound C1 and has a viscosity of 25 cP or more, and where the raw material nonwoven has a concave part and a high density part, and the high density portion is located at the bottom of the concave portion and has a fiber density higher than that of any other portion, where the C1 compound is: at least one kind of compound selected from: organically modified silicone, polyhydric alcohol fatty acid ester and wax selected from ceresin, paraffin, petrolatum, mineral oil and liquid isoparaffin and represented by the following Formula [XV]; and has a spreading coefficient of 15 mN / m or more for a liquid having a surface tension of 50 mN / m;

3. A method of producing a nonwoven fabric containing at least one type of fibers selected from sheath-core hot-melt composite fibers, thermally extendable fibers, thermally non-extensible fibers, heat-shrinkable fibers, fibers without thermal shrinkage, three-dimensionally twisted fibers, as constituent fibers, curled fibers and hollow fibers, including the step of liquid coating the nonwoven fabric from the starting materials using a flexographic printing system, where the liquid coating contains the following compound C2 and has a viscosity of 25 cP or more, and where the raw material nonwoven has a concave part and a high density part, and the high density portion is located at the bottom of the concave portion and has a higher fiber density than any other portion: where the C2 compound is: at least one kind of compound selected from: organically modified silicone, polyhydric alcohol fatty acid ester and wax selected from ceresin, paraffin, petrolatum, mineral oil and liquid isoparaffin and represented by the following Formula [XV]; and has a spreading coefficient greater than 0 mN / m for a liquid having a surface tension of 50 mN / m and a tension of 20 mN / m or less at an interface with a liquid having a surface tension of 50 mN / m;

4. A method for producing a nonwoven fabric according to any one of claims 1 to 3, wherein the viscosity is 25 cps or more and 1000 cps or less. 5. A method for producing a nonwoven fabric according to any one of claims 1 to 4, wherein the water solubility of the liquid film breaking agent, compound C1 or compound C2 is 0 g or more and 0.025 g or less, preferably 0.0025 g or less. 6. A method of obtaining a nonwoven material according to any one of paragraphs. 2, 4, or 5, in which the surface tension of the compound C1 for a liquid having a surface tension of 50 mN / m is 20 mN / m or less. 7. A method for producing a nonwoven fabric according to any one of claims 1 to 6, wherein the surface tension of the liquid film breaker, C1 compound or C2 compound is 32 mN / m or less. 8. The method for producing a nonwoven fabric according to any one of claims 1 to 7, wherein the hardness of the flexographic plate used in the coating with the flexographic printing system is 62 ° or more. 9. A method for producing a nonwoven fabric according to any one of claims 1 to 8, wherein the gap between the flexographic plate and the substrate roll used in the coating by the flexographic printing system is -750 µm or more and 750 µm or less. 10. A method for producing a nonwoven fabric according to any one of claims 1 to 9, wherein the volume of the anilox roll used in the coating by the flexographic printing system is 1 cm ³ / m ² or more and 30 cm ³ / m ² or less. 11. Nonwoven fabric for an absorbent article obtained using the method according to any one of claims 1-10. 12. Nonwoven fabric for an absorbent article containing at least one kind of fibers selected from sheath-core hot melt composite fibers, thermally extendable fibers, thermally non-extensible fibers, heat shrinkable fibers, fibers without thermal shrinkage, three-dimensionally twisted fibers, as constituent fibers, potentially curled fibers and hollow fibers, comprising a concave portion and a high density portion that is located at the bottom of the concave portion and has a fiber density higher than that of any other portion, wherein the nonwoven fabric is divided into a high density portion and a non-high density portion other than a high density portion, and the nonwoven fabric contains an agent for breaking a liquid film in the non-high density portion, where the agent for breaking the film is: at least one kind of compound selected from organically modified silicone, polyhydric alcohol fatty acid ester and wax selected from ceresin, paraffin, petrolatum, mineral oil and liquid isoparaffin and represented by the following Formula [XV]; and has a spreading coefficient of 15 mN / m or more for a liquid having a surface tension of 50 mN / m, or has a spreading coefficient greater than 0 mN / m for a liquid having a surface tension of 50 mN / m and a tension of 20 mN / m or less at an interface with a liquid having a surface tension of 50 mN / m;

13. Nonwoven fabric for an absorbent article, containing as constituent fibers at least one kind of fibers selected from sheath-core hot-melt composite fibers, thermally extendable fibers, thermally non-extensible fibers, heat-shrinkable fibers, fibers without thermal shrinkage, three-dimensionally twisted fibers, potentially curled fibers and hollow fibers, comprising a concave portion and a high density portion that is located at the bottom of the concave portion and has a fiber density higher than that of any other portion, wherein the nonwoven fabric is divided into a high density portion and a non-high density portion other than a high density portion, and the nonwoven fabric contains the following C1 compound in the non-high density portion: where the C1 compound is: at least one kind of compound selected from: organically modified silicone, polyhydric alcohol fatty acid ester and wax selected from ceresin, paraffin, petrolatum, mineral oil and liquid isoparaffin and represented by the following Formula [XV]; and has a spreading coefficient of 15 mN / m or more for a liquid having a surface tension of 50 mN / m;

14. The nonwoven fabric of claim 13, wherein the spreading coefficient of the compound C1 for the liquid having a surface tension of 50 mN / m is 20 mN / m or more. 15. Nonwoven material for an absorbent article, containing as constituent fibers at least one kind of fibers selected from sheath-core hot-melt composite fibers, thermally extendable fibers, thermally non-extensible fibers, heat-shrinkable fibers, fibers without thermal shrinkage, three-dimensionally twisted fibers, potentially curled fibers and hollow fibers, comprising a concave portion and a high density portion that is located at the bottom of the concave portion and has a fiber density higher than that of any other portion, wherein the nonwoven fabric is divided into a high density portion and a non-high density portion other than a high density portion, and the nonwoven fabric contains the following C2 compound in the non-high density portion: where the C2 compound is: at least one kind of compound selected from: organically modified silicone, polyhydric alcohol fatty acid ester and wax selected from ceresin, paraffin, petrolatum, mineral oil and liquid isoparaffin and represented by the following Formula [XV]; and has a spreading coefficient greater than 0 mN / m for a liquid having a surface tension of 50 mN / m and a tension of 20 mN / m or less at an interface with a liquid having a surface tension of 50 mN / m;

16. A nonwoven fabric according to any one of claims 11 to 15, wherein the water solubility of the liquid film breaker, C1 or C2 compound is 0 g or more and 0.025 g or less. 17. A nonwoven fabric according to any one of claims 11 to 16, wherein the surface tension of the liquid film breaker, C1 compound or C2 compound for a liquid having a surface tension of 50 mN / m is 20 mN / m or less. 18. A nonwoven fabric according to any one of claims 11 to 17, wherein the surface tension of the liquid film breaker, C1 compound or C2 compound is 32 mN / m or less. 19. Nonwoven fabric according to any one of claims 11-18, where the agent for breaking the liquid film, the C1 compound or the C2 compound is localized in at least part of the points at which the fibers are intertwined with each other, or at thermally fused points in the part not having a high density nonwoven fabric. 20. Nonwoven fabric according to any one of claims 11 to 19, wherein the content of the liquid film breaker, C1 compound or C2 compound in the high density portion is 10 mass% or less in terms of their proportion with respect to the liquid film breaker content or a compound in a non-high density part. 21. A nonwoven fabric according to any one of claims 11 to 20, wherein the liquid film breaker, compound C1 or compound C2 is located only in the non-high density portion. 22. A nonwoven fabric according to any one of claims 11-21, wherein the high density portion is a portion in which the fibers are consolidated by compressing the nonwoven in the thickness direction by embossing. 23. A nonwoven fabric according to any one of claims 11 to 22, wherein the melting point of the liquid film breaking agent, C1 compound or C2 compound is preferably -220 ° C or more and 40 ° C or less. 24. A nonwoven fabric according to any one of claims 11 to 23, wherein the contact angle of the fibers for the deionized water in the high density portion is 90 ° or less. 25. A nonwoven fabric according to any one of claims 11-24, further comprising an anionic surfactant of the phosphoric acid ester type in addition to a liquid film breaker, Compound C1 or Compound C2. 26. A nonwoven fabric according to any one of claims 11 to 25, wherein the liquid film breaker compound C1 or compound C2 is preferably a compound having a weight average molecular weight of 500 or more and 50,000 or less. 27. An absorbent article comprising a nonwoven material according to any one of claims 11 to 26. 28. A topsheet of an absorbent article selected from a sanitary napkin, a baby diaper, or an incontinent adult diaper using the nonwoven fabric of any one of claims 11 to 26.

Images