JP2016060995A - Ridged and grooved nonwoven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ridged and grooved nonwoven fabric excellent in liquid permeability in which return liquid is less likely to occur, and an absorbent article including the same.SOLUTION: A ridged and grooved nonwoven fabric 10A of the invention is formed by containing thermoplastic fibers and comprises a first face 1a and a second face 1b that is located on the opposite side to the first face 1a, and at least the first face 1a has a ridged and grooved shape formed by a plurality of ridged parts 5 which protrude on the first face 1a side and joined parts 4 (grooved parts) located between the adjoining ridged parts 5, 5. The ridged and grooved nonwoven fabric 10A has a fiber treating agent attached thereon. The fiber treating agent includes following polyorganosiloxane ((A) component), a phosphoric ester type anionic surfactant ((B) component), and polyoxyalkylene modified polyhydric alcohol fatty acid ester ((C) component).SELECTED DRAWING: Figure 1

Description

  The present invention relates to an uneven nonwoven fabric having unevenness on at least one surface and an absorbent article using the same.

  As a surface sheet of an absorbent article such as a disposable diaper, it is conventionally known to use an uneven nonwoven fabric having unevenness on at least one side. With regard to the uneven nonwoven fabric, for example, in Patent Document 1, the first nonwoven fabric and the second nonwoven fabric are partially heat-sealed to form a joined portion, and the first nonwoven fabric is in a non-joined portion surrounded by the joined portion. A three-dimensional sheet that protrudes in a direction away from the second nonwoven fabric and has a large number of hollow protrusions inside is described. Further, Patent Document 2 describes a structure having a large number of projecting portions that project toward the wearer's skin, and the projecting portions have an internal space that is open on the absorber side. Patent Document 3 discloses a multilayer nonwoven fabric having a plurality of groove portions that are recessed in the thickness direction, and a plurality of convex portions that protrude in the thickness direction and are adjacent to the plurality of groove portions and have a basis weight higher than the basis weight of the groove portions. Is described. Patent Documents 1 to 3 mainly disclose a technique related to the uneven shape of the nonwoven fabric, and do not particularly describe a technique related to hydrophilicity control of the nonwoven fabric.

  In addition, the present applicant firstly heats the core-sheath type composite fiber having a hydrophilic agent attached to the surface thereof, and changes the hydrophilicity of the fiber, and using this technique, the hydrophilicity is partially improved. The technique which manufactures the nonwoven fabric which fell is proposed (refer patent document 4). The hydrophilizing agent described in Patent Document 4 adheres to the surface of the constituent fibers of the nonwoven fabric and increases its hydrophilicity as compared with that before the hydrophilizing agent is attached. , Anionic, cationic, zwitterionic and nonionic surfactants can be used.

  Patent Document 5 describes a low-concentration aqueous liquid of a synthetic fiber treatment agent used for antistatic or lubrication of synthetic fibers. This aqueous liquid contains an alkyl phosphate potassium salt having 12 to 22 carbon atoms as an essential component. Patent Document 5 discloses polyoxyalkylene polyhydric alcohol fatty acid ester, polyoxyalkylene polyhydric alcohol fatty acid ester as an optional component of this aqueous liquid. Organosiloxane and the like are described. The technique of Patent Document 5 is a technique mainly aimed at improving the storage stability of a low-concentration aqueous liquid of a synthetic fiber treatment agent. Patent Document 5 describes a nonwoven fabric as a constituent member of an absorbent article. When applied to the above, no contrivance for satisfying various properties required for the constituent members is described.

JP 2004-174234 A JP 2012-143543 A JP 2008-25081 A JP 2010-168715 A JP 2005-54333 A

  The performance required of absorbent articles and their surface sheets has improved year by year, and conventional uneven nonwoven fabrics have room for improvement in that they do not leave liquid on the uneven surface side facing the wearer's skin. It was.

  The subject of this invention is related with providing the uneven nonwoven fabric which can eliminate the fault which the prior art mentioned above has.

The present invention comprises a thermoplastic fiber, has a first surface and a second surface located on the opposite side thereof, and at least the first surface has a plurality of protrusions protruding toward the first surface side, and the An uneven nonwoven fabric having recesses and protrusions located between the protrusions, to which a fiber treatment agent is attached, and the fiber treatment agent comprises the following components (A), (B) and ( C) An uneven nonwoven fabric containing a component.
(A) Polyorganosiloxane (B) Phosphate ester type anionic surfactant (C) Polyoxyalkylene-modified polyhydric alcohol fatty acid ester

  The present invention also relates to an absorbent article comprising an absorbent body and a surface sheet disposed on the skin-facing surface side of the absorbent body, wherein the uneven nonwoven fabric of the present invention is used as the surface sheet, It is an absorptive article arrange | positioned so that a 1st surface may oppose a wearer's skin.

  The uneven nonwoven fabric of the present invention is excellent in liquid permeability and hardly causes so-called liquid return in which the permeated liquid shifts in the direction opposite to the permeation direction. For example, when used as a top sheet of an absorbent article, it was supplied. The liquid is unlikely to remain on the skin facing surface, and the liquid that has passed through the top sheet is unlikely to return to the skin facing surface. Moreover, since the absorbent article of this invention has the uneven | corrugated nonwoven fabric of this invention as a surface sheet, it is hard to produce a liquid residue and a liquid return, and it is hard to give a wearer discomfort, such as stickiness.

FIG. 1 is a schematic perspective view of a first embodiment of the uneven nonwoven fabric of the present invention. 2 is a cross-sectional view taken along the line II of FIG. FIG. 3 is an explanatory view of the function and effect of the uneven nonwoven fabric shown in FIG. FIG. 4 is a schematic diagram showing a preferred method for producing the uneven nonwoven fabric of the first embodiment. FIG. 5 is an enlarged schematic cross-sectional view showing a portion in FIG. 4 where the first nonwoven fabric and the second nonwoven fabric are joined by a heat roll. FIG. 6 is a schematic perspective view of a second embodiment of the uneven nonwoven fabric of the present invention. FIG. 7 is a schematic diagram illustrating a cross section along the thickness direction of the uneven nonwoven fabric illustrated in FIG. 6. FIG. 8 is a schematic view showing an apparatus suitably used for manufacturing the uneven nonwoven fabric shown in FIG. FIG. 9 is an enlarged view showing a main part of the support in the manufacturing apparatus shown in FIG. FIG. 10 is a schematic diagram showing a state in which the web is shaped by the manufacturing apparatus shown in FIG. FIG. 11 is a schematic view showing a state in which the fibers of the web are heat-sealed by the apparatus shown in FIG. FIG. 12 is a schematic perspective view of a third embodiment of the uneven nonwoven fabric of the present invention. FIG. 13 is a schematic diagram illustrating a cross section along the thickness direction of the uneven nonwoven fabric illustrated in FIG. 12. FIG. 14 is a schematic diagram showing a hot air treatment step in a preferred method for producing the uneven nonwoven fabric shown in FIG. FIG. 15: is a typical perspective view of the modification of 3rd Embodiment of the uneven | corrugated nonwoven fabric of this invention.

  A fiber treatment agent is adhered to the uneven nonwoven fabric of the present invention. The fiber treatment agent according to the present invention is attached to the surface of the constituent fiber (thermoplastic fiber) of the uneven nonwoven fabric, and the hydrophilicity of the surface of the constituent fiber is increased as compared with that before attaching the fiber treatment agent. And a polyorganosiloxane (component (A)), a phosphate ester type anionic surfactant (component (B)), and a polyoxyalkylene-modified polyhydric alcohol fatty acid ester (component (C)).

  The fiber to which the fiber treatment agent containing the three components (A) to (C) is attached becomes a fiber in which a hydrophilic component easily penetrates into the fiber by heat treatment. The component (C) has a hydrophilicity higher than that of a surfactant having a normal linear hydrocarbon chain because the component has a structure in which hydrophobic chains are easily arranged in a radial pattern and a hydrophilic group is easily surrounded. Easily penetrates into the fiber. The component (A) used in combination with the component (C) has a high hydrophobicity and promotes penetration of the surfactant having a hydrocarbon chain such as the component (C) into the fiber. The hydrophilicity of the surface changes to a low value by heat treatment. This is because when the polysiloxane chain of the component (A) and the surfactant having a hydrocarbon chain such as the component (C) are mixed, the alkyl chain is incompatible. It is considered that this occurs because the surfactant having a hydrocarbon chain penetrates into the more easily accustomed fiber when the fiber is heated and melted. Thereby, the fiber to which the fiber treatment agent containing the three components (A) to (C) is attached becomes a fiber whose hydrophilicity is likely to be lowered by heat treatment, for example, on a web that is one step of the manufacturing process described later. In the process of blowing hot air or the web, the amount of heat received by the fibers in the web is naturally different between the hot air blowing surface and the opposite surface (net surface), so the fibers on the hot air blowing surface and the opposite side The amount of heat received by the surface fiber is different, and the value of the contact angle between the fiber on the hot air blowing surface and the fiber on the opposite side also changes. Utilizing this fact, a nonwoven fabric having a hydrophilicity gradient is produced from one surface, which is the first surface when the nonwoven fabric is viewed in plan, toward the other surface, which is the second surface opposite to the first surface. It can be done.

  In addition, unless otherwise explained, the “fiber treatment agent” which is a standard for the content of the fiber treatment agent-containing component such as the component (A), the component (B) and the component (C) is “attached to the nonwoven fabric”. It is a “fiber treatment agent”, not a fiber treatment agent before being attached to the nonwoven fabric. When the fiber treatment agent is attached to the uneven nonwoven fabric, since the fiber treatment agent is usually diluted with an appropriate solvent such as water, the content of the fiber treatment agent-containing component, for example, the component (A) in the fiber treatment agent The content of can be based on the total mass of the diluted fiber treatment agent.

  Moreover, in the nonwoven fabric to which the fiber treatment agent adheres like the uneven nonwoven fabric of this invention, when analyzing the adhered fiber treatment agent, it is preferable to analyze according to the following procedure. First, the nonwoven fabric to be analyzed is washed with a suitable solvent. Examples of the cleaning solvent include a mixed solvent of ethanol and methanol and a mixed solvent of ethanol and water. When the nonwoven fabric to be analyzed is a sanitary product or a surface sheet of an absorbent article such as a disposable diaper for children or adults, an adhesive used for joining the surface sheet to another member in the absorbent article After being melt-softened by heating with a heating means such as a dryer, the top sheet is peeled off, and the peeled top sheet is washed with a cleaning solvent. Next, the solvent used for washing the non-woven fabric to be analyzed (cleaning solvent containing the fiber treatment agent) is dried, and the residue is quantified so that the total amount of the fiber treatment agent adhering to the non-woven fabric is obtained. It can be measured. In addition, after selecting an appropriate column and solvent according to the composition of the residue, each component is fractionated by high performance liquid chromatography, and each fraction is further subjected to MS measurement, NMR measurement, elemental analysis, etc. By performing the above, the structure of each fraction can be identified. When the fiber treatment agent contains a polymer compound, it becomes easier to identify the constituent components by using a technique such as gel permeation chromatography (GPC) together.

[Polyorganosiloxane (component (A))]
As the polyorganosiloxane that is one of the essential components of the fiber treatment agent according to the present invention, any of a linear one and a crosslinked two-dimensional or three-dimensional network structure can be used. It is a shape.

Specific examples of polyorganosiloxanes suitable for the present invention are alkylalkoxysilanes, arylalkoxysilanes, alkylhalosiloxane polymers or cyclic siloxanes, and the alkoxy groups are typically methoxy groups. As the alkyl group, an alkyl group which may have a side chain having 1 to 18 carbon atoms, preferably 1 to 8 carbon atoms, particularly 1 to 4 carbon atoms is suitable. Examples of the aryl group include a phenyl group, an alkylphenyl group, and an alkoxyphenyl group. Instead of an alkyl group or an aryl group, a cyclic hydrocarbon group such as a cyclohexyl group or a cyclopentyl group, or an aralkyl group such as a benzyl group may be used.
The polyorganosiloxane referred to in the present invention is a concept that does not include a polyorganosiloxane modified with a highly hydrophilic polyoxyethylene (POE) chain from the viewpoint of increasing the contact angle of the fiber surface by heating. .

  The most typical polyorganosiloxanes preferred for the present invention are polydimethylsiloxane, polydiethylsiloxane, polydipropylsiloxane and the like, with polydimethylsiloxane being particularly preferred.

  The molecular weight of the polyorganosiloxane is preferably a high molecular weight. Specifically, the weight average molecular weight is preferably 100,000 or more, more preferably 150,000 or more, further preferably 200,000 or more, preferably Is 1 million or less, more preferably 800,000 or less, and still more preferably 600,000 or less. Further, as the polyorganosiloxane, two or more kinds of polyorganosiloxanes having different molecular weights may be used. When two or more kinds of polyorganosiloxanes having different molecular weights are used, one of them has a weight average molecular weight of preferably 100,000 or more, more preferably 150,000 or more, further preferably 200,000 or more, and preferably Is not more than 1 million, more preferably not more than 800,000, still more preferably not more than 600,000, and the other one has a weight average molecular weight of preferably less than 100,000, more preferably not more than 50,000, more preferably 30,000. It is 5,000 or less, more preferably 20,000 or less, preferably 2000 or more, more preferably 3000 or more, and still more preferably 5000 or more. Further, a preferable blending ratio (the former: latter) of the polyorganosiloxane having a weight average molecular weight of 100,000 or more and the polyorganosiloxane having a weight average molecular weight of less than 100,000 is a mass ratio, preferably 1:10 to 4: 1. More preferably, it is 1: 5 to 2: 1.

The weight average molecular weight of the polyorganosiloxane is measured using GPC. The measurement conditions are as follows. The calculated molecular weight is calculated with polystyrene.
Separation column: GMHHR-H + GMHHR-H (cation)
Eluent: L Farmin DM20 / CHCl ₃
Solvent flow rate: 1.0 ml / min
Separation column temperature: 40 ° C

The content of the polyorganosiloxane in the fiber treatment agent is preferably 1% by mass or more, preferably 5% by mass or more, based on the total mass of the fiber treatment agent, from the viewpoint of increasing the change in hydrophilicity due to heat treatment. More preferably it is. Further, from the viewpoint of easily absorbing the liquid on the nonwoven fabric surface, the content is preferably 30% by mass or less, and more preferably 20% by mass or less, with respect to the total mass of the fiber treatment agent. For example, the content of the polyorganosiloxane in the fiber treatment agent is preferably 1% by mass to 30% by mass, and preferably 5% by mass to 20% by mass with respect to the total mass of the fiber treatment agent. Further preferred.
Further, when the uneven nonwoven fabric of the present invention is applied as a surface sheet in an absorbent article, the viewpoint of preventing the hydrophilicity on the top side (side near the skin of the absorbent article wearer) from being excessively lowered, that is, described later. From the viewpoint of preventing the liquid flow distance to be increased and the amount of excretory liquid adhering to the skin from increasing, the content of the polyorganosiloxane in the fiber treatment agent is preferably within the above range.

  A commercially available product can also be used as the polyorganosiloxane. For example, “KF-96H-1 million Cs” manufactured by Shin-Etsu Silicone Co., “SH200 Fluid 1000000 Cs” manufactured by Toray Dow Corning Co., Ltd. and those containing two types of polyorganosiloxane include “ KM-903 "or" BY22-060 "manufactured by Toray Dow Corning Co. can be used.

[Phosphate ester type anionic surfactant (component (B))]
The phosphoric acid ester type anionic surfactant, which is one of the essential components of the fiber treatment agent according to the present invention, improves the properties of raw cotton through the card machine and the uniformity of the web. For the purpose of improving the productivity of nonwoven fabrics and preventing deterioration of quality, it is a kind of anionic surfactant that is blended into fiber treatment agents. Specific examples include alkyl ether phosphates, dialkyl phosphates, and alkyl phosphates. Of these, alkyl phosphates are preferred from the viewpoint of processability.
Various alkyl ether phosphates can be used without particular limitation. For example, those having saturated carbon chains such as stearyl ether phosphate, myristyl ether phosphate, lauryl ether phosphate, palmityl ether phosphate, oleyl ether phosphate, palmitoleyl ether phosphate, etc. Unsaturated carbon chains and those having side chains in these carbon chains. More preferably, it is a completely neutralized or partially neutralized salt of a mono- or dialkyl phosphate ester having 16 to 18 carbon chains. Examples of the salt of alkyl ether phosphate include alkali metals such as sodium and potassium, ammonia, and various amines. Alkyl phosphate ester can be used individually by 1 type or in mixture of 2 or more types.
Specific examples of the alkyl phosphate ester include those having a saturated carbon chain such as stearyl phosphate ester, myristyl phosphate ester, lauryl phosphate ester, palmityl phosphate ester, oleyl phosphate ester, palmitoleyl phosphate ester, etc. Examples include unsaturated carbon chains and those having side chains in these carbon chains. More preferably, it is a completely neutralized or partially neutralized salt of a mono- or dialkyl phosphate ester having 16 to 18 carbon chains. Examples of the alkyl phosphate ester salt include alkali metals such as sodium and potassium, ammonia, and various amines. Alkyl phosphate ester can be used individually by 1 type or in mixture of 2 or more types.

  The content of the phosphate ester type anionic surfactant in the fiber treatment agent is preferably 5% by mass or more based on the total mass of the fiber treatment agent from the viewpoint of card machine passability and web uniformity. More preferably, it is 10% by mass or more, and from the viewpoint of not hindering the hydrophobicity of the fiber by the polyorganosiloxane resulting from the heat treatment, the total mass of the fiber treatment agent is preferably 30% by mass or less, More preferably, it is 25 mass% or less.

[Polyoxyalkylene-modified polyhydric alcohol fatty acid ester (component (C))]
The polyoxyalkylene-modified polyhydric alcohol fatty acid ester, which is one of the essential components of the fiber treatment agent according to the present invention, that is, the component (C), makes the decrease in hydrophilicity due to heat treatment during the production of the nonwoven fabric more remarkable. That is, it is blended into the fiber treatment agent for the purpose of significantly reducing the hydrophilicity of a desired portion in the nonwoven fabric, and is a kind of nonionic surfactant. The component (C) is a kind of a polyhydric alcohol fatty acid ester obtained by esterifying a hydroxyl group of a polyhydric alcohol with a fatty acid, and is a modified product obtained by adding an alkylene oxide to the polyhydric alcohol fatty acid ester. (C) component can be manufactured in accordance with a conventional method, for example, can be manufactured according to Unexamined-Japanese-Patent No. 2007-91852.

  (C) As a polyhydric alcohol which is one of the raw materials of component (or polyhydric alcohol fatty acid ester), for example, ethylene glycol, diethylene glycol, polyethylene glycol (molecular weight 200 to 11000), propylene glycol, dipropylene glycol, polypropylene glycol (Molecular weight 250-4000), 1,3-butylene glycol, glycerin, polyglycerin (degree of polymerization 2-30), erythritol, xylitol, sorbitol, mannitol, inositol, sorbitan, sorbide, sucrose, trehalose, erulose, lactosucrose , Cyclodextrin, maltitol, lactitol, palatinit, panitol, reduced starch syrup and the like. Preferred are polyethylene glycol, glycerin, erythritol, sorbitol, sorbitan, sorbide, and sucrose, and particularly preferred are sorbitol, sorbitan, and sorbide.

  Examples of the fatty acid that is another raw material of the component (C) (or polyhydric alcohol fatty acid ester) include, for example, a saturated or unsaturated fatty acid having 6 to 22 carbon atoms, a mixed fatty acid containing these as a main component, or Examples thereof include branched chain fatty acids having 8 to 36 carbon atoms. The fatty acid may partially contain a hydroxyl group. Specifically, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, cis-9-octadecenoic acid, eicosanoic acid, docosanoic acid, tetracosanoic acid, hexacosanoic acid, octacosanoic acid , 2-ethylhexylic acid, isostearic acid, and the like, and coconut oil fatty acid and beef tallow fatty acid which are naturally derived mixed fatty acids may be used, preferably fatty acids having 8 to 18 carbon atoms, particularly preferably dodecanoic acid, octadecane. Acid, cis-9-octadecenoic acid.

  When the main component of the polyhydric alcohol fatty acid ester constituting the component (C) is to increase the hydrophobic chain and increase the hydrophobicity, the molecular shape is not increased linearly but three-dimensionally. Thus, from the viewpoint of obtaining a shape that can be easily taken into the fiber, an esterified product of a trivalent or higher alcohol and an esterification rate of the alcohol component of 90% or higher are preferable. Here, the main component is the most abundant component in the polyhydric alcohol fatty acid ester, and is preferably contained in an amount of 50% by mass or more based on the total mass of the polyhydric alcohol fatty acid ester. For example, examples of the trivalent alcohol include glycerin, examples of the tetravalent alcohol include erythritol, and examples of the pentavalent alcohol include xylitol.

  Particularly preferred as the polyhydric alcohol fatty acid ester constituting the component (C) is castor oil (hardened castor oil). Castor oil is a glycerin fatty acid ester derived from the seeds of castor, which is a plant belonging to the family Dromeliaceae, and about 90% of the constituent fatty acid is ricinoleic acid. That is, as the component (D), ester oil of glycerin and a fatty acid mainly composed of ricinoleic acid is preferable.

  In the component (C), examples of the alkylene oxide added to the polyhydric alcohol fatty acid ester include ethylene oxide, propylene oxide, butylene oxide, and the like. Particularly preferred as the component (C) is a polyoxyethylene (POE) -modified polyhydric alcohol fatty acid ester in which the alkylene oxide added to the polyhydric alcohol fatty acid ester is ethylene oxide, and particularly preferred is the polyhydric alcohol fatty acid ester. Is POE-modified castor oil (POE-modified hardened castor oil), which is castor oil (hardened castor oil).

  In component (C), the number of moles of alkylene oxide added to the polyhydric alcohol fatty acid ester may exceed 20 moles from the viewpoint of improving the liquid absorption performance of the uneven nonwoven fabric (reducing the amount of remaining liquid or reducing the amount of liquid flow). Preferably, 40 mol or more is particularly preferable. However, if the number of added moles of alkylene oxide is too large, the hydrophilicity of the uneven nonwoven fabric will be excessively increased. For example, when the uneven nonwoven fabric is used as a surface sheet in an absorbent article, the liquid remaining amount may increase. Therefore, the added mole number is preferably 80 moles or less, more preferably 60 moles or less.

  The content of the component (C) in the fiber treatment agent is such that the hydrophilicity of the uneven nonwoven fabric is increased, and the effect of lowering the hydrophilicity due to heat treatment during the production of the uneven nonwoven fabric is remarkably exhibited. Preferably, it is 5% by mass or more, more preferably 10% by mass or more with respect to the mass, and is preferably based on the total mass of the fiber treatment agent from the viewpoint of suppressing an increase in the remaining amount of liquid due to strong hydrophilization. Is 20% by mass or less, more preferably 15% by mass or less.

In the fiber treatment agent according to the present invention, the content ratio (the former: latter) of the polyorganosiloxane as the component (A) and the polyoxyalkylene-modified polyhydric alcohol fatty acid ester as the component (C) is preferably a mass ratio, 1: 2 to 3: 1, more preferably 1: 1 to 2: 1.
Further, in the fiber treatment agent according to the present invention, the content ratio (the former: the latter) of the polyorganosiloxane of the component (A) and the phosphate ester type anionic surfactant of the component (B) is a mass ratio, The ratio is preferably 1: 5 to 10: 1, more preferably 1: 2 to 3: 1.

[Other ingredients]
The fiber treatment agent according to the present invention may contain other components in addition to the components (A) to (C) described above. Examples of other components to be blended in addition to the components (A) to (C) include treating agents such as anti-sticking agents such as modified silicone. As other components, anionic, cationic, amphoteric and nonionic surfactants (surfactants other than the components (B) and (C)) can be used.

  Examples of the anionic surfactant that can be contained in the fiber treatment agent according to the present invention (anionic surfactant other than the component (B)) include alkyl ether phosphate sodium salt, dialkyl phosphate sodium salt, and dialkyl sulfosuccinate sodium. Salt, alkylbenzene sulfonate sodium salt, alkyl sulfonate sodium salt, alkyl sulfate sodium salt, secondary alkyl sulfate sodium salt and the like (all alkyls preferably have 6 to 22 carbon atoms, particularly preferably 8 to 22 carbon atoms). These may use other alkali metal salts such as potassium salts in place of sodium salts. Here, as anionic surfactants other than the component (B), dialkylsulfosuccinic acid having a two-chain bulky hydrophobic group is used from the viewpoint of high hydrophilicity and further lowering the hydrophilicity of the fiber by heat treatment. preferable.

  Examples of the cationic surfactant that can be contained in the fiber treatment agent according to the present invention include alkyl (or alkenyl) trimethyl ammonium halide, dialkyl (or alkenyl) dimethyl ammonium halide, alkyl (or alkenyl) pyridinium halide, and the like. These compounds preferably have an alkyl group or an alkenyl group having 6 to 18 carbon atoms. Examples of the halogen in the halide compound include chlorine and bromine.

  Examples of amphoteric surfactants that can be contained in the fiber treatment agent according to the present invention include alkyl (C1-30) dimethylbetaine, alkyl (C1-30) amidoalkyl (C1-4) dimethylbetaine. Betaine-type amphoteric surfactants such as alkyl (1-30 carbons) dihydroxyalkyl (1-30 carbons) betaine, sulfobetaine-type amphoteric surfactants, and alanine type [alkyl (1-30 carbons) amino Propionic acid type, alkyl (1-30 carbon atoms) iminodipropionic acid type, etc. amphoteric surfactants, glycine types such as alkylbetaines [alkyl (1-30 carbon atoms) aminoacetic acid type, etc.] amphoteric surfactants, etc. Examples thereof include aminosulfonic acid type amphoteric surfactants and aminosulfonic acid type amphoteric surfactants such as alkyl (having 1 to 30 carbon atoms) taurine type.

  Examples of nonionic surfactants (other nonionic surfactants other than the component (C)) that can be contained in the fiber treatment agent according to the present invention include glycerin fatty acid esters and poly (preferably n = 2 to 10) glycerin fatty acids. Esters, polyhydric alcohol fatty acid esters such as sorbitan fatty acid esters (preferably each having 8 to 60 carbon atoms in the fatty acid), polyoxyalkylene (added mole number 2 to 60) alkyl (8 to 22 carbon atoms) amide, polyoxyalkylene (Addition mole number 2-60) alkyl (carbon number 8-22) ether, polyoxyalkylene modified silicone, amino modified silicone, etc. are mentioned. Here, as the nonionic surfactant other than the component (C), polyoxyethylene (POE) alkylamide is used from the viewpoint of imparting appropriate flexibility to the fiber and providing an excellent feeling of use. preferable. In addition to POE alkylamide, when non-oxygen surfactant is used in combination with polyoxyethylene and polyoxypropylene (POE, POP) -modified silicone, moderate smoothness is imparted to the fiber, and the nonwoven fabric processability is further improved. This is preferable because it is secured more reliably.

  The concavo-convex nonwoven fabric of the present invention to which the fiber treatment agent is adhered is configured to include thermoplastic fibers, and at least one surface has concavo-convex portions. That is, the uneven nonwoven fabric of the present invention has a first surface and a second surface located on the opposite side, and at least the first surface is between the plurality of protrusions protruding toward the first surface and the protrusions. It is an uneven | corrugated nonwoven fabric which has the unevenness | corrugation which consists of a recessed part located. Hereinafter, the uneven nonwoven fabric of the present invention will be described based on its preferred embodiments with reference to the drawings.

  1 to 5 show a first embodiment of the uneven nonwoven fabric of the present invention. The nonwoven fabric 10A of the first embodiment is configured to include a thermoplastic fiber, and as shown in FIGS. 1 and 2, a first surface 1a having a plurality of convex portions 5 to form an uneven surface; The second surface 1b is flat or has a level of unevenness that is clearly smaller than that of the uneven surface.

  The nonwoven fabric 10A of the first embodiment has a multilayer structure in which a plurality of layers are laminated in the thickness direction, more specifically, a two-layer structure as shown in FIGS. In the nonwoven fabric 10 </ b> A, the first nonwoven fabric 2 and the second nonwoven fabric 3 are partially heat-sealed to form a joint portion 4, and the first nonwoven fabric 2 is surrounded by the joint portion 4. Projecting in the direction away from the second nonwoven fabric 2 at the joint 6, a large number of convex portions 5 having a hollow interior are formed. The joint portion 4 is a “concave portion” located between two adjacent convex portions 5 and 5 on the first surface 1 a, and constitutes the concave and convex portions of the first surface 1 a together with the convex portion 5.

  The non-joining portion 6 is a portion surrounded by the joining portion 4 in the plan view of the nonwoven fabric 10 </ b> A, and includes the first nonwoven fabric 2 and the second nonwoven fabric 3. It is preferable that the non-joining part 6 surrounded by the joining part 4 is surrounded by a plurality of joining parts 4 spaced apart from each other. In the nonwoven fabric 10 </ b> A shown in FIG. 1, the periphery is surrounded by four joint portions 4, but the number of joint portions 4 surrounding the non-joint portion 6 is not limited to four, for example, two or three It can also be 5, 6, or 7 or more. The number of joints 4 surrounding the non-joint part 6 is preferably 2 or more, more preferably 3 or more, still more preferably 4 or more, and preferably 12 or less, more preferably 8 Or less, more preferably 6 or less.

  In addition, in the nonwoven fabric having a multilayer structure such as the nonwoven fabric 10A, each layer constituting the multilayer structure includes, for example, the type of fiber material constituting the layer, the thickness of the fiber, the presence or absence of a hydrophilization treatment, and a layer formation method. Differentiated by factors. When the cross section in the thickness direction of the nonwoven fabric having a multilayer structure is enlarged by an electron microscope, the boundary portion between two layers adjacent in the thickness direction can be observed due to these factors.

  Moreover, when the uneven nonwoven fabric of this invention is a multilayer structure, the fiber processing agent containing the (A) component, (B) component, and (C) component mentioned above is at least of the several layer which comprises the multilayer structure. It may be included in one layer, and may be included in all of a plurality of layers. In the nonwoven fabric 10A of the first embodiment, only the second nonwoven fabric 3 contains the fiber treatment agent.

  In 10 A of nonwoven fabrics of 1st Embodiment, the 2nd nonwoven fabric 3 in the non-joining part 6 enclosed by the junction part 4 has a hydrophilic gradient from which hydrophilicity falls as it approaches the junction part 4. FIG. More specifically, as shown in FIG. 2, the second nonwoven fabric 3 in the non-joined part 6 is adjacent to the joined part 4 from the distal part P1 having a distance of 2 mm or more between the joined parts 4. The hydrophilicity gradually decreases toward the proximal portion P3.

  The “hydrophilicity” referred to in the present invention is determined based on the contact angle of the fiber measured by the method described below. Specifically, a low hydrophilicity is synonymous with a large contact angle, and a high hydrophilicity is synonymous with a small contact angle.

Whether or not the second nonwoven fabric 3 in the non-joint portion 6 has a hydrophilicity gradient in which the hydrophilicity gradually decreases from the proximal portion P3 toward the distal portion P1 is determined based on whether the proximal portion P3, the distal portion P1, or the like. And the contact angles of the fibers taken out from the middle portion P2 between the proximal portion P3 and the distal portion P1, and the contact angles of the proximal portion P3, the middle portion P2 and the distal portion P1 are as follows. (1) is satisfied, and when the difference in contact angle between the proximal portion P3 and the distal portion P1 is 3 degrees or more, the hydrophilicity gradually decreases from the proximal portion P3 toward the distal portion P1. Judge as having a gradient.
Contact angle of proximal part P3> Contact angle of middle part P2> Contact angle of distal part P1 (1)

  Regarding the second nonwoven fabric 4 in the non-joined portion 6, the proximal portion P3 adjacent to the joined portion 4 has a distance from the outer peripheral edge of the joined portion 4 in a range of 0 mm or more and less than 1 mm in the plan view of the nonwoven fabric 10A. The fiber for measuring the contact angle is taken out from the point where the distance is 0.1 mm. Similarly, in the plan view of the nonwoven fabric 10A, the distal portion P1 has a distance from the outer peripheral edge of the joint portion 4 in the range of 2 mm or more, and the fiber for measuring the contact angle is taken out from the point where the distance is 2 mm. . Similarly, in the plan view of the nonwoven fabric 10A, the middle portion P2 has a distance from the outer peripheral edge of the joint portion 4 in the range of more than 1 mm and less than 2 mm, and the fiber for measuring the contact angle has a distance of 1.2 mm. Remove from the spot. The distance from the outer periphery of the junction part 4 here is measured on a straight line passing through the center of the convex part 5 and the center of the joint part 4 in a plan view of the nonwoven fabric. Moreover, it is preferable to take out the fiber which measures a contact angle from the center part vicinity of the thickness direction of a nonwoven fabric.

[Measurement method of contact angle]
A fiber is taken out from a predetermined part of the nonwoven fabric, and a contact angle of water with the fiber 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 amount of liquid discharged from an ink jet type water droplet discharge part (manufactured by Cluster Technology, Inc., pulse injector CTC-25 having a discharge part pore diameter of 25 μm) is set to 20 picoliters, and a water drop is dropped directly above the fiber. The state of dripping is recorded on a high-speed recording device connected to a horizontally installed camera. The recording device is preferably a personal computer incorporating a high-speed capture device from the viewpoint of image analysis or image analysis later. In this measurement, an image is recorded every 17 msec. In the recorded video, the first image of water drops on the fiber taken out from the non-woven fabric is attached to the attached software FAMAS (software version is 2.6.2, analysis method is droplet method, analysis method is θ / 2 method) The image processing algorithm is non-reflective, the image processing image mode is frame, the threshold level is 200, and the curvature is not corrected). And the contact angle. The fiber taken out from the nonwoven fabric is cut into a fiber length of 1 mm, and the fiber is placed on a sample table of a contact angle meter and kept horizontal. Two different contact angles are measured for each fiber. N = 5 contact angles are measured to one decimal place, and a value obtained by averaging a total of 10 measured values (rounded to the second decimal place) is defined as the contact angle.

  Moreover, in the nonwoven fabric 10A of 1st Embodiment, compared with the part 4a (bottom part of the recessed part in the 1st surface 1a) in the 1st surface 1a side in the junction part 4, it corresponds to this part 4a in the 2nd surface 1b. The portion 4b has a higher hydrophilicity. More specifically, in the joint portion 4, the hydrophilicity gradually increases from the first surface 1a side to the second surface 1b side.

  In the nonwoven fabric 10A of the first embodiment, as shown in FIG. 3, when a liquid is supplied to the first surface 1a side which is an uneven surface, a part of the liquid is a convex portion as shown in a path R1. After entering into the 1st nonwoven fabric 2 in the non-joining part 6 from the junction part 4 vicinity between 5, the inside of the 2nd nonwoven fabric 3 or on the 2nd nonwoven fabric 3 is made hydrophilic according to the gradient of the hydrophilicity which the 2nd nonwoven fabric 3 has. It moves from the vicinity of the joint 4 having a low degree toward the central part having a high degree of hydrophilicity. Therefore, it is difficult for the liquid to remain in the vicinity of the peripheral edge portion of the joint portion 4 where the fiber density is high when the joint portion 4 is formed, and the nonwoven fabric 10A as a whole has excellent liquid permeability. Further, the liquid remaining in the joint portion 4 also flows from the first surface 4a having a low hydrophilicity to the second surface 4b having a high hydrophilicity as shown in the path R3. The liquid hardly remains in 4, and the nonwoven fabric 10A as a whole has excellent liquid permeability.

  When using 10 A of nonwoven fabrics of 1st Embodiment as a surface sheet of an absorbent article, as shown in FIG. 3, it is used so that the 1st surface 1a side used as an uneven surface may face a wearer's skin side. From the viewpoint of sufficiently exerting the performance of the nonwoven fabric 10A. In FIG. 3, the code | symbol 20 is an absorber of an absorbent article. In addition, when using as a surface sheet of an absorbent article, the liquid which exists in the part which forms the convex part 5 in the 1st nonwoven fabric 2 is near the 2nd nonwoven fabric 3 from the top part P4 of the convex part 5 of the 1st nonwoven fabric 2. When the wearer's body pressure or the like is applied to the vicinity of the position portion P1, as shown in the path R2, the transition is made directly to the second nonwoven fabric 3.

  When the nonwoven fabric 10A of the first embodiment is used as a top sheet of an absorbent article, it is difficult for the liquid to remain in the vicinity of the peripheral portion of the joint portion 4 in the non-joint portion 6 in the paths R1 and R3 as described above. The liquid 20 such as urine and menstrual blood excreted from the wearer does not remain on the first surface 1a disposed opposite to the wearer's skin, and there is an uncomfortable feeling such as stickiness. It is preferable from the viewpoint of preventing it from occurring and preventing a colored liquid such as menstrual blood from conspicuous and improving the appearance of the absorbent article after liquid absorption.

  Thus, the nonwoven fabric 10A of the first embodiment hardly retains the liquid on the surface (first surface 1a) side to which the liquid is supplied, and is excellent in liquid permeability as a whole. Moreover, it can be produced by a simple manufacturing process as described later, and is excellent in productivity.

  From the viewpoint of improving the liquid permeability of the nonwoven fabric 10A and reducing the remaining amount of liquid when used as a top sheet of an absorbent article, the proximal portion P3 and the distal portion P1 have a contact angle of the proximal portion P3. On the assumption that the contact angle of the distal portion P1 is higher, the difference in the contact angle of water with respect to the fiber is preferably 3 degrees or more, more preferably 4 degrees or more, and preferably 20 degrees or less, more preferably 15 degrees or less, more preferably 10 degrees or less, more specifically, preferably 3 degrees or more and 20 degrees or less, more preferably 4 degrees or more and 15 degrees or less, more preferably 4 degrees or more and 10 degrees or less.

  From the same viewpoint, the proximal portion P3 has a water contact angle with respect to the fiber of preferably 70 degrees or more, more preferably 80 degrees or more, and preferably 120 degrees or less, more preferably 100 degrees or less, more preferably 95 degrees or less, more specifically, preferably 70 degrees or more and 120 degrees or less, more preferably 80 degrees or more and 100 degrees or less, and more preferably 80 degrees or more and 95 degrees or less.

  From the same viewpoint, the distal portion P1 has a water contact angle with respect to the fiber of preferably 60 degrees or more, more preferably 70 degrees or more, and preferably 95 degrees or less, more preferably 90 degrees or less, and more specifically. Is preferably 60 degrees or more and 95 degrees or less, more preferably 70 degrees or more and 90 degrees or less.

  From the same point of view, the difference in the contact angle of water with respect to the fiber between the proximal part P3 and the middle part P2 is based on the assumption that the contact angle of the proximal part P3 is higher than the contact angle of the middle part P2. , Preferably 1 degree or more, more preferably 2 degrees or more, and preferably 15 degrees or less, more preferably 10 degrees or less. Further, the difference between the contact angle of water with respect to the fiber is preferably between the middle part P2 and the distal part P1 on the assumption that the contact angle of the middle part P2 is higher than the contact angle of the distal part P1. It is 1 degree or more, more preferably 2 degrees or more, and preferably 15 degrees or less, more preferably 10 degrees or less.

  From the same point of view, the portion 4a on the first surface 1a side (the bottom of the recess in the first surface 1a) of the joint 4 and the portion 4b corresponding to the portion 4a on the second surface 1b are the contact angle of the portion 4a. Is higher than the contact angle of the portion 4b, the difference in the contact angle of water with respect to the fiber is preferably 1 degree or more, more preferably 2 degrees or more, and preferably 15 degrees or less, more preferably 10 degrees. Degrees or less, more specifically, preferably 1 degree or more and 15 degrees or less, more preferably 2 degrees or more and 10 degrees or less.

  Further, in the nonwoven fabric 10A of the first embodiment, the hydrophilicity is higher in any part of the second surface 1b than in the top portion P4 of the convex portion 5 in the first surface 1a. More specifically, in the first nonwoven fabric 2 forming the first surface 1a, the hydrophilicity at the top portion P4 of the convex portion 5 is greater than the hydrophilicity of the distal portion P1 of the second nonwoven fabric 3 forming the second surface 1b. Is also low. That is, in the first nonwoven fabric 2, the contact angle at the top portion P <b> 4 of the convex portion 5 is higher than the contact angle at the distal portion P <b> 1 of the second nonwoven fabric 3. The fiber for measuring the contact angle at the top portion P4 is taken out from the center of the convex portion 5 in the plan view of the nonwoven fabric 10A.

  When the nonwoven fabric 10A is used as the top sheet of the absorbent article because the hydrophilicity at the top portion P4 of the convex portion 5 of the first nonwoven fabric 2 is lower than the hydrophilicity at the distal portion P1 of the second nonwoven fabric 3, The liquid existing in the portion forming the convex portion 5 in the non-woven fabric 2 is shown in the path R2 by applying the wearer's body pressure or the like from the top portion P4 of the convex portion 5 to the vicinity of the proximal portion P1 of the second non-woven fabric 3. As shown (see FIG. 3), it becomes easy to shift to the second nonwoven fabric 3 directly.

  The difference in the contact angle of water with respect to the fiber is assumed on the assumption that the contact angle of the top part P4 of the convex part 5 is higher than the contact angle of the distal part P1 between the top part P4 and the distal part P1 of the convex part 5. Preferably it is 1 degree or more, preferably 20 degrees or less, more preferably 15 degrees or less.

  In the nonwoven fabric 10A of the first embodiment, in contrast to the second nonwoven fabric 3 having a gradient in hydrophilicity, the first nonwoven fabric 2 has the same hydrophilicity in any part of the first nonwoven fabric 2. ing. In order to form such a first nonwoven fabric 2, a fiber treatment containing the aforementioned component (A), component (B) and component (C) as a fiber treatment agent for hydrophilizing the second nonwoven fabric 3. Instead of the agent, for example, a fiber treating agent called an oil agent that has been conventionally used for imparting hydrophilicity to the fiber may be used. Typical examples of such fiber treatment agents (oil agents) include various surfactants. Examples of the surfactants include anionic, cationic, amphoteric and nonionic surfactants (component (B). And other surfactants other than the component (C).

  In the nonwoven fabric 10A of the first embodiment, the size, height, and the like of the convex portion 5 can be appropriately set according to the specific use purpose, but when used as a surface sheet of an absorbent article, the convex portion 5 It is preferable that the height H (refer FIG. 1) of the part 5 is 1 mm or more and 10 mm or less, especially 1.5 mm or more and 6 mm or less. Further, the bottom dimension (the dimension of the non-joining part 6) A along the X direction corresponding to the conveying direction at the time of manufacture, and the bottom dimension (non-joining) of the convex part 5 along the Y direction orthogonal to the X direction. The dimension (B) of the part 6 is preferably 1 mm or more and 30 mm or less, particularly preferably 1.5 mm or more and 10 mm or less. Similarly, the length C of the joint portion 4 in the X direction and the length D of the joint portion 4 in the Y direction are preferably 0.5 mm or more and 20 mm or less, and particularly preferably 0.8 mm or more and 5 mm or less.

In the nonwoven fabric 10A of the first embodiment, the number of convex portions 5 is preferably 5 or more, more preferably 20 or more, and preferably 50 or less, per unit area (1 cm ² ) of the nonwoven fabric 10A. More preferably, it is 30 or less.

  Further, the adhesion amount of the fiber treatment agent containing the component (A), the component (B) and the component (C) described above is preferably a ratio (%) to the total mass of the fiber excluding the fiber treatment agent, preferably 0.1. It is not less than 0.1% by mass, more preferably not less than 0.1% by mass and not more than 1.0% by mass, and more preferably not less than 0.2% by mass and not more than 0.6% by mass.

  It is preferable that the 1st nonwoven fabric 2 and the 2nd nonwoven fabric 3 which comprise the nonwoven fabric 10A of 1st Embodiment are non-stretchable substantially. A substantially non-stretchable non-woven fabric has, for example, an elongation limit of 105% or less, and elongation exceeding this causes material destruction or permanent distortion. As the 1st nonwoven fabric 2 and the 2nd nonwoven fabric 3, what is conventionally used as a nonwoven fabric which comprises the surface sheet in an absorptive article, for example can be especially used without a restriction | limiting. For example, various nonwoven fabrics such as a nonwoven fabric produced by a card method, a spunbond nonwoven fabric, a melt blown nonwoven fabric, a spunlace nonwoven fabric, and a needle punched nonwoven fabric can be mentioned. The 1st nonwoven fabric 2 and the 2nd nonwoven fabric 3 may be the nonwoven fabric of the same manufacturing method, and may be the nonwoven fabric of a different manufacturing method.

  Moreover, it is preferable that at least any one of the 1st nonwoven fabric 2 and the 2nd nonwoven fabric 3, Preferably both contain the heat-fusible fiber which is 1 type of a thermoplastic fiber. Examples of the heat-fusible fiber include a heat-fusible core-sheath composite fiber, a non-heat-stretchable fiber, a heat-shrinkable fiber, a three-dimensional crimped fiber, a latent-crimped fiber, and a hollow fiber. Can be used alone or in combination of two or more. Of these fibers, it is particularly preferable to use a heat-fusible core-sheath composite fiber.

  The heat-fusible fiber has a heat-fusible property before and after the fiber treatment agent is attached, and has a core-sheath type composite structure. The core-sheath type composite fiber may be a concentric core-sheath type, an eccentric core-sheath type, a side-by-side type, or an irregular shape. In particular, a concentric core-sheath type is preferable. Regardless of the form of the fibers, from the viewpoint of producing a flexible nonwoven fabric having good touch and the like, the fineness of the heat-fusible fiber is preferably 1.0 dtex or more and 10.0 dtex or less. More preferably, it is 0 dtex or more and 8.0 dtex or less.

  The fineness of the heat-fusible fiber may be the same between the first nonwoven fabric 2 and the second nonwoven fabric 3, or may be different. When the fineness of the heat-fusible fiber in each of the nonwoven fabrics 2 and 3 is different, the fineness of the heat-fusible fiber contained in the second nonwoven fabric 3 is more than the fineness of the heat-fusible fiber contained in the first nonwoven fabric 2. It is preferable that this is smaller. By carrying out like this, the gradient which a capillary force increases toward the 2nd nonwoven fabric 3 from the 1st nonwoven fabric 2 arises, and that and the gradient of the hydrophilicity resulting from a fiber processing agent combine, and it is 2nd from the 1st nonwoven fabric 2 to the 2nd. There is an advantageous effect that the drawability of the liquid toward the nonwoven fabric 3 is improved. However, in the present invention, since the gradient of the hydrophilicity attributed to the fiber treatment agent is sufficiently imparted, the first nonwoven fabric 2 can be used without using a heat-fusible fiber having a small fineness for the second nonwoven fabric 3. The drawability of the liquid toward the second nonwoven fabric 3 is sufficient.

Examples of the polyethylene resin constituting the sheath of the core-sheath type composite fiber P include low density polyethylene (LDPE), high density polyethylene (HDPE), and linear low density polyethylene (LLDPE). In particular, high density polyethylene having a density of 0.935 to 0.965 g / cm ³ is preferable. The resin component constituting the sheath portion of the core-sheath type composite fiber P is preferably a polyethylene resin alone, but other resins can also be blended. Other resins to be blended include polypropylene resin, ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl alcohol copolymer (EVOH), and the like. However, as for the resin component which comprises a sheath part, it is preferable that 50 mass% or more in the resin component of a sheath part is especially 70 mass% or more and 100 mass% or less is a polyethylene resin.

The sheath portion of the core-sheath type composite fiber P imparts heat-fusibility to the heat-sealable core-sheath type composite fiber, and at the time of heat treatment, the (A) component, (B) component, and (C) component described above are added. It plays the role of taking in the contained fiber treatment agent. On the other hand, a core part is a part which provides intensity | strength to a heat-fusible core-sheath-type composite fiber. As the resin component constituting the core part of the core-sheath type composite fiber P, a resin component having a melting point higher than that of the polyethylene resin that is the constituent resin of the sheath part can be used without particular limitation. Examples of the resin component constituting the core include polyolefin resins such as polypropylene (PP) (excluding polyethylene resin), polyester resins such as polyethylene terephthalate (PET), and polybutylene terephthalate (PBT). Furthermore, a polyamide-type polymer, the copolymer of 2 or more types of the resin component mentioned above, etc. can be used. A plurality of types of resins can be blended and used. In this case, the melting point of the core is the melting point of the resin having the highest melting point.
The heat-fusible core-sheath composite fiber to which the fiber treatment agent is attached has a difference in melting point between the resin component constituting the core part and the resin component constituting the sheath part (the former-the latter) at 20 ° C. or higher. It is preferable that the non-woven fabric is easily produced, and is preferably 150 ° C. or lower. The melting point when the resin component constituting the core is a blend of a plurality of types of resins is the melting point of the resin having the highest melting point.

  At least a part of the fibers (thermoplastic fibers) constituting the nonwoven fabric 10A of the first embodiment may be heat-extensible fibers whose length is extended by heating. For example, the heat-fusible core-sheath conjugate fiber described above may be a heat-extensible conjugate fiber. Examples of the heat-extensible fiber include a fiber that spontaneously extends as the crystal state of the resin changes due to heating. The heat-extensible fiber is present in the nonwoven fabric in a state where its length is extended by heating and / or in a state where it can be extended by heating. When heat-extensible fibers are heated, the fiber treatment agent on the surface is easily taken into the inside, and it becomes easy to form a plurality of portions having greatly different hydrophilicity by heat treatment in the fibers and the nonwoven fabric produced using the fibers.

A preferable heat-extensible conjugate fiber has a first resin component that constitutes a core portion and a second resin component that comprises a polyethylene resin and constitutes a sheath portion, and the first resin component is a second resin component. Has a higher melting point. A 1st resin component is a component which expresses the heat | fever extensibility of this fiber, and a 2nd resin component is a component which expresses heat-fusibility.
The melting points of the first resin component and the second resin component were determined by thermal analysis of a finely cut fiber sample (sample weight 2 mg) using a differential scanning calorimeter (DSC6200 manufactured by Seiko Instruments Inc.) at a heating rate of 10 ° C./min. The melting peak temperature of each resin is measured and defined by the melting peak temperature. When the melting point of the second resin component cannot be clearly measured by this method, the resin is defined as “resin having no melting point”. In this case, the temperature at which the second resin component is fused to such an extent that the strength of the fusion point of the fiber can be measured is used as the temperature at which the molecular flow of the second resin component begins, and this is used instead of the melting point.

  The preferred orientation index of the first resin component in the heat-stretchable conjugate fiber is naturally different depending on the resin used. For example, in the case of a polypropylene resin, the orientation index is preferably 60% or less, more preferably 40% or less. More preferably, it is 25% or less. When the first resin component is polyester, the orientation index is preferably 25% or less, more preferably 20% or less, and even more preferably 10% or less. On the other hand, the second resin component preferably has an orientation index of 5% or more, more preferably 15% or more, and more preferably 30% or more. The orientation index is an index of the degree of orientation of the polymer chain of the resin constituting the fiber. And when the orientation index of a 1st resin component and a 2nd resin component is each said value, a heat | fever extensible composite fiber comes to expand | extend by heating.

  The orientation index of the first resin component and the second resin component is determined by the method described in paragraphs [0027] to [0029] of JP2010-168715A. Moreover, the method in which each resin component in the thermally stretchable conjugate fiber achieves the orientation index as described above is described in paragraphs [0033] to [0036] of JP-A No. 2010-168715.

  The heat stretchable conjugate fiber can be stretched by heat at a temperature lower than the melting point of the first resin component. The heat-extensible conjugate fiber preferably has a thermal elongation rate of 0.5% or more and 20% or less at a temperature 10 ° C. higher than the melting point of the second resin component (softening point in the case of a resin having no melting point). More preferably, it is 3% or more and 20% or less, and more preferably 5.0% or more and 20% or less. A nonwoven fabric containing fibers having such a thermal elongation rate becomes bulky due to the elongation of the fibers or has a three-dimensional appearance. The thermal elongation rate of the fiber is determined by the method described in paragraphs [0031] to [0032] of JP2010-168715A.

  The ratio (mass ratio, the former: latter) of the first resin component and the second resin component in the heat-extensible conjugate fiber is 10:90 to 90:10, particularly 20:80 to 80:20, especially 50:50 to 70. : 30 is preferable. As the fiber length of the heat-extensible conjugate fiber, an appropriate length is used according to the method of manufacturing the nonwoven fabric 10A of the first embodiment. For example, when the nonwoven fabric 10A is manufactured by a card method as will be described later, the fiber length is preferably about 30 mm or more and 70 mm or less.

  The fiber diameter of the heat-extensible composite fiber is appropriately selected according to the specific use of the nonwoven fabric 10A. When the nonwoven fabric 10A is used as a constituent member of an absorbent article such as a surface sheet of the absorbent article, it is preferable to use a heat-extensible composite fiber having a fiber diameter of 10 μm to 35 μm, particularly 15 μm to 30 μm as a constituent fiber. . In addition, the fiber diameter of the heat-extensible conjugate fiber is reduced when stretched, and the fiber diameter is a fiber diameter when the nonwoven fabric is actually used.

  As the heat-extensible composite fiber, in addition to the above-described heat-extensible composite fiber, Japanese Patent No. 4131852, Japanese Patent Application Laid-Open No. 2005-350836, Japanese Patent Application Laid-Open No. 2007-303035, Japanese Patent Application Laid-Open No. 2007-204899, The fibers described in JP 2007-204901 A and JP 2007-204902 A can also be used.

  In the nonwoven fabric 10A of the first embodiment, as a heat-fusible fiber (thermoplastic fiber), a mixture of heat-extensible fibers and non-heat-extensible fibers may be used. The non-heat-extensible fiber is a bicomponent composite fiber that includes a high-melting component and a low-melting component, and the low-melting component is continuously present in the length direction on at least a part of the fiber surface. The form of the composite fiber (non-heat-extensible fiber) includes various forms such as a core-sheath type and a side-by-side type, and any form can be used. The heat-fusible composite fiber is drawn at the raw material stage. The stretching treatment referred to here is a stretching operation with a stretching ratio of about 2 to 6 times. The mixing ratio of the heat-extensible fiber and the non-heat-extensible fiber is a mass ratio, and the former: the latter is preferably 1: 9 to 9: 1, and more preferably 4: 6 to 6: 4. Thereby, it becomes easier to recover the bulk of the nonwoven fabric with hot air, and it is possible to obtain a nonwoven fabric with better touch and dryness than using each fiber alone.

Moreover, 10 A of nonwoven fabrics of 1st Embodiment may contain the titanium oxide. Titanium oxide preferably has a particle size in the range of, for example, 0.1 μm or more and 2 μm or less, and can be spun by containing it in a resin in the spinning process. Nonwoven fabrics containing titanium oxide have increased whiteness and high concealment. In particular, an absorbent article using a nonwoven fabric containing titanium oxide as a surface material or the like has high concealability of body fluids such as menstrual blood and urine absorbed in the absorbent body, and has a visual dry feeling from the appearance after use. can get.
Titanium oxide can be added at an arbitrary content, but from the viewpoint of enhancing concealability, the amount of titanium oxide contained in the nonwoven fabric 10A is preferably 0.5% by mass or more based on the total mass of the nonwoven fabric 10A. More preferably, it is 1% by mass or more, and from the viewpoints of productivity, fiber strength properties, spinnability in the fiber manufacturing process, processability in the nonwoven fabric manufacturing process, and cutability in the post-processing process, It is 5 mass% or less, More preferably, it is 4.5 mass% or less.

  Next, one embodiment of a method for producing the nonwoven fabric 10A of the first embodiment will be described with reference to FIGS. Regarding the method for producing the nonwoven fabric 10A of the present embodiment, points that are not particularly described can be carried out in the same manner as the method described in Patent Document 1 (particularly the method described in paragraphs [0021] to [0025]).

  As shown in FIG.4 and FIG.5, the manufacturing method of 10 A of nonwoven fabrics of this embodiment becomes the 1st roll 201 whose surrounding surface is uneven | corrugated shape, and the uneven | corrugated shape and mesh shape of a 1st roll. After the first nonwoven fabric 2 is bitten into the meshing portion with the second roll 202 having a concavo-convex shape on the peripheral surface and the concavo-convex shape is formed, the second nonwoven fabric 3 is formed into a convex portion 201a in the first roll 201. The first nonwoven fabric 2 positioned above and a step of joining with the heat roll 203 are provided.

  What is important in the manufacturing method of the nonwoven fabric 10A of this embodiment is that the first nonwoven fabric 2 and the second nonwoven fabric 3 are joined to the first nonwoven fabric 2 and the second nonwoven fabric 3 before joining the first nonwoven fabric 2 and the second nonwoven fabric 3 (A). The fiber treatment agent containing a component, (B) component, and (C) component is included. Thereby, the 1st nonwoven fabric 2 and the 2nd nonwoven fabric 3 are heated and pressurized between the convex part 201a and the heat roll 203 in the 1st roll 201, and the junction part 4 (concave part in the 1st surface 1a). Is formed, the first non-woven fabric 2 and / or the second non-woven fabric 3 containing the fiber treating agent is subjected to a greater amount of heat as it is closer to the joint 4, thereby reducing the hydrophilicity. In the first non-woven fabric 2 and / or the second non-woven fabric 3 containing the agent, the above-described gradient of hydrophilicity is generated such that the hydrophilicity decreases as the joint portion 4 is approached.

  In such a manufacturing method, the nonwoven fabric 10A of this embodiment includes the fiber treatment agent containing the above-described (A) component, (B) component, and (C) component only in the second nonwoven fabric 3, This is heated and pressed between the convex portion 201 a and the heat roll 203 in the first roll 201 to form the joint portion 4.

In the manufacturing method of the nonwoven fabric 10A, as a method of including the fiber treatment agent in the nonwoven fabric before joining the first nonwoven fabric 2 and the second nonwoven fabric 3, the raw material fibers are at the stage of fibers before being made into a web or nonwoven fabric, Examples thereof include a method of applying a fiber treatment agent to the fibers, a method of applying a fiber treatment agent after forming raw fibers into webs and nonwoven fabrics by various known methods, and a method of using these in combination.
For example, as the first or second non-woven fabric, when using a non-woven fabric in which the web obtained by the card machine is made into a non-woven fabric by fiber entanglement, hydroentanglement, fusion by resin, etc., the stage of raw fiber before making the web Thus, a fiber treatment agent may be applied to the fiber, or a fiber treatment agent may be applied at the web stage or after forming into a nonwoven fabric.
Moreover, as a 1st or 2nd nonwoven fabric, when using the nonwoven fabric made into a nonwoven fabric by the fusion | bonding of the intersection of the fiber by the hot air process of an air through system as a 1st or 2nd nonwoven fabric, from a viewpoint of the nonuniformity prevention of oil agent application, It is desirable to apply a fiber treatment agent before forming a nonwoven fabric.
Moreover, when using a spunbond nonwoven fabric as a 1st or 2nd nonwoven fabric, it is preferable to apply | coat a fiber processing agent after forming into a nonwoven fabric on the manufacturing method.
The above-described method of applying the fiber treatment agent for each nonwoven fabric is merely an example. You may employ | adopt the method of kneading a fiber processing agent in raw material fiber independently or in combination with another method. In addition, as a method of applying a fiber treatment agent to raw fiber, fiber web, nonwoven fabric, etc., any application method such as spray application, application by slot coater, application by roll transfer, immersion in fiber treatment agent, etc. is adopted. it can.

  In the manufacturing method of the nonwoven fabric 10A of the present embodiment, the first nonwoven fabric 2 and the second nonwoven fabric by the heat roll 203 while holding the first nonwoven fabric 2 formed with irregularities on the peripheral surface of the first roll 201 by suction. 3 is preferable. As a result, an air flow from the joined portion 4 toward the non-joined portion 6 occurs at the time of forming the joined portion 4 or immediately before or immediately thereafter, thereby easily reducing the hydrophilicity at a location away from the joined portion 4. It becomes easy to give a gradient to the second nonwoven fabric as described above. As a suction method, a suction method (not shown) may be provided in the concave and convex recesses of the first roll 201 for suction.

  FIGS. 6 to 11 show a second embodiment of the uneven nonwoven fabric of the present invention, and FIGS. 12 to 15 show a third embodiment of the uneven nonwoven fabric of the present invention. Regarding these embodiments, the description of the first embodiment is appropriately applied to components that are not particularly described.

  The nonwoven fabric 10B of 2nd Embodiment is comprised including the thermoplastic fiber, and as shown in FIG.6 and FIG.7, it has the 1st surface 1a and the 2nd surface 1b located in the other side. Yes. The nonwoven fabric 10B is preferably applied to a top sheet of an absorbent article such as a sanitary napkin or a disposable diaper. In this case, the first surface 1a side is used toward the wearer's skin side, and the second surface 1b side is used. Is preferably used by being disposed on the absorbent side inside the absorbent article. Hereinafter, although it demonstrates considering the embodiment which uses the 1st surface 1a side of the nonwoven fabric 10B shown to drawing toward a wearer's skin side, this invention is limited and is not interpreted by this.

  The nonwoven fabric 10B uses an air-through nonwoven fabric as the nonwoven fabric 10B when the nonwoven fabric 10B is manufactured by a preferable method described later. The nonwoven fabric 10B has a single-layer structure or a multilayer structure in which a plurality of layers are laminated. The air-through nonwoven fabric refers to a nonwoven fabric produced through a process (preferably a process of allowing penetration) of fluids such as gas or water vapor at 50 ° C. or higher to the web or nonwoven fabric, and includes not only the nonwoven fabric produced only in this process. In addition, it also means a nonwoven fabric produced by adding this process to a nonwoven fabric produced by another method, or a nonwoven fabric produced by performing some process before or after this process.

  As shown in FIGS. 6 and 7, the nonwoven fabric 10 </ b> B has a plurality of first protrusions 11 protruding to the first surface 1 a side in a plan view of the sheet-like nonwoven fabric. The 1st convex part 11 has the internal space 11K with which the 2nd surface 1b side was open | released. Moreover, the nonwoven fabric 10B has the several 2nd convex part 12 which protrudes in the 2nd surface 1b side on the opposite side to the 1st surface 1a side. The second convex portion 12 has an internal space 12K that is open on the first surface 1a side. These 1st and 2nd convex parts 11 and 12 are alternately distribute | arranged alternately along each of two different directions which cross | intersect each other in planar view over the whole surface of the nonwoven fabric 10B, for example. The two different directions are, as a specific example, an X direction that is one direction of a different direction and a Y direction that is another direction different from the X direction. In the form shown in FIGS. 6 and 7, the convex portion viewed from the first surface 1 a side is the first convex portion 11, and the concave portion is the second convex portion 12. On the contrary, the convex part seen from the 2nd surface 1b side is the 2nd convex part 12, and a recessed part becomes the 1st convex part 11. FIG. Accordingly, the first convex portion 11 and the second convex portion 12 are partially shared.

  The 1st and 2nd convex parts 11 and 12 have peak parts 11T and 12T, respectively. Moreover, the 1st and 2nd convex parts 11 and 12 have the wall parts 13 and 14 of a cyclic | annular structure between the top parts 11T and 12T and the opening parts 11H and 12H of internal space, respectively. The top portions 11T and 12T are formed in a circular truncated cone shape or a hemispherical shape.

  If the 1st and 2nd convex parts 11 and 12 are seen in detail, the protruding shape of the 1st convex part 11 will be rather hemispherical, on the other hand, the protruding shape of the 2nd convex part 12 will be round at the top part. It has a certain cone or truncated cone shape. In the second embodiment, the first and second convex portions 11 and 12 are not limited to the shape described above, and may have any protruding shape. For example, it is practical to have various cone shapes (in this specification, the cone shape means a wide range including a cone, a truncated cone, a pyramid, a truncated pyramid, an oblique cone, and the like). In the second embodiment, the first and second convex portions 11 and 12 hold a truncated cone shape or hemispherical internal space 11K or 12K having a rounded top portion similar to the outer diameter thereof.

  The wall 13 located between the top of the first protrusion 11 (hereinafter also referred to as the first protrusion top) 11T and the opening 11H has an annular structure in the first protrusion 11. Further, the wall portion 14 located between the top portion of the second convex portion 12 (hereinafter also referred to as the second convex portion top portion) 12T and the opening portion 12H forms an annular structure in the second convex portion 12. The wall portion 14 shares a part with a part of the wall portion 13. The “annular” is not particularly limited as long as it has an endless series of shapes in a plan view of the nonwoven fabric 10B, and may be any shape such as a circle, an ellipse, a rectangle, or a polygon in the plan view of the nonwoven fabric 10B. May be. From the viewpoint of suitably maintaining the continuous state of the nonwoven fabric 10B, a circular shape or an oval shape is preferable. Furthermore, speaking of “annular” as a three-dimensional shape, a cylindrical shape, an oblique cylindrical shape, an elliptical columnar shape, a truncated cone shape, a truncated oblique cone shape, a truncated elliptical cone shape, a truncated rectangular pyramid shape, and a truncated oblique pyramid shape From the viewpoint of realizing a continuous sheet state, a cylindrical shape, an elliptical column shape, a truncated cone shape, and a truncated elliptical cone shape are preferable.

  The nonwoven fabric 10B having the first and second convex portions 11 and 12 provided as described above does not have a bent portion, and is configured by a curved surface that is continuous as a whole. Thus, it is preferable that the nonwoven fabric 10B has a continuous structure in the surface direction. “Continuous” means that there are no intermittent portions or small holes. However, micropores such as gaps between fibers are not included in the small holes. The small hole can be defined, for example, as a hole having a diameter equivalent to a circle of 1.0 mm or more.

  In the nonwoven fabric 10B of 2nd Embodiment, the fiber density of a constituent fiber is different regarding the thickness direction. Specifically, the fiber density increases from the first protrusion top 11T toward the second protrusion top 12T. The fiber density is the mass of fibers per unit volume of the nonwoven fabric 10B. High fiber density means that the amount of fibers present per unit volume of the nonwoven fabric 10B is large and the distance between fibers is small. Low fiber density means that the amount of fibers present per unit volume of the nonwoven fabric 10B is small and the distance between fibers is large. Therefore, the part with high fiber density has high capillary force, and the part with low fiber density has low capillary force.

  When the fiber density is viewed along the thickness direction of the nonwoven fabric 10B, the fiber density of the first convex portion top portion 11T is the lowest, and the fiber density of the second convex portion top portion 12T is the highest. The fiber density of the wall parts 13 and 14 located between the 1st convex part top part 11T and the 2nd convex part top part 12T is the fiber density of the 1st convex part top part 11T, and the fiber density of the 2nd convex part top part 12T. It is an intermediate value. Thus, in the nonwoven fabric 10B, the fiber density is higher in the order of the first convex portion top portion 11T <the wall portion 13, 14 <the second convex portion top portion 12T. Therefore, also regarding the capillary force, the capillary force increases in the order of the first convex portion top portion 11T <the wall portion 13, 14 <the second convex portion top portion 12T. In this case, the fiber density and the capillary force may be gradually increased in the order of the first convex portion top portion 11T <wall portion 13, 14 <second convex portion top portion 12T, or stepwise in a stepwise manner. It may be increased. In order to impart such a fiber density gradient to the nonwoven fabric 10B, the nonwoven fabric 10B may be manufactured according to the manufacturing method described later.

The specific value of the fiber density of the nonwoven fabric 10 </ ^b > B is preferably 30 / mm ² or more, particularly 50 / mm ² or more, and 130 / mm ² or less, particularly 120 for the first convex portion 11. / Mm ² or less is preferable. For example the fiber density of the first protrusion 11 is preferably 30 present / mm ² or more 130 present / mm ² or less, further preferably 50 present / mm ² or more, 120 / mm ² or less. On the other hand, regarding the 2nd convex part 12, it is preferable that it is 250 pieces / mm < ² > or more, especially 270 pieces / mm < ² > or more, 500 pieces / mm < ² > or less, and especially 480 pieces / mm < ² > or less are preferable. For example, the fiber density of the second convex portion 12 is preferably 250 / mm ² or more and 500 / mm ² or less, and more preferably 270 / mm ² or more and 480 / mm ² or less. The fiber density of the first convex portion 11 is measured at a position near the center of the layer thickness T _L1 in the first convex portion 11. The fiber density of the second convex portion 12 is measured at a position near the center of the layer thickness T _L2 in the second convex portion 12. The method for measuring the fiber density is as follows.

[Measurement method of fiber density]
The cut surface of the nonwoven fabric portion is magnified using a scanning electron microscope (adjusted to a magnification capable of measuring about 30 to 60 fiber cross sections; 150 to 500 times), and the cut per fixed area (about 0.5 mm ² ). The number of cross-sections of the fibers cut by the face was counted. Next, it was converted into the number of cross-sections of fibers per 1 mm ² and this was defined as the fiber density. The measurement was performed at three locations, and the fiber density of the sample was averaged. As the scanning electron microscope, for example, JCM-5100 (trade name) manufactured by JEOL Ltd. can be used.

Referring to the dimensions specifications in nonwoven 10B of the second embodiment, the thickness of the nonwoven fabric 10B, the total thickness when the side view of the nonwoven fabric 10B of (apparent thickness) and sheet thickness T _S, curved to the uneven nonwoven fabric local thickness of 10B (the substantial thickness) and the layer thickness _{T L} (see FIG. 7). Sheet thickness _{T S} is may be appropriately adjusted depending on the application, when using a nonwoven fabric 10B as a surface sheet of an absorbent article, such as diapers and sanitary products, preferably 1mm or 7mm or less, more preferably 1.5mm or more 5mm or less . By the sheet thickness T _S in this range, fast fluid absorption rate of use, suppress the liquid return from the absorbent, furthermore, it is possible to realize a moderate cushioning property.

The layer thickness T _L may be different at each site in the nonwoven fabric 10B, and may be adjusted as appropriate depending on the application. When the nonwoven fabric 10B is used as a surface sheet for absorbent articles such as diapers and sanitary products, the layer thickness T _L1 of the first convex portion top portion 11T is preferably 0.1 mm or more and 3 mm or less, and 0.4 mm or more and 2 mm or less. More preferred. The preferable ranges of the layer thickness T _{L2 of} the second convex portion top portion 12T and the layer thickness T _L3 of the wall portions 13 and 14 are the same as the layer thickness of the first convex portion top portion 11T. The relationship between the layer thicknesses T _L1 , T _L2 , and T _L3 is preferably T _L1 > T _L3 > T _L2 . Thereby, in the 1st convex part 11, especially on the skin surface side, fiber density is low and can implement | achieve favorable skin contact. On the other hand, the second convex portion 12 has a high fiber density, is not easily crushed, and can be made of a nonwoven fabric excellent in cushioning properties and liquid absorption speed without being out of shape.

The sheet thickness T _S and the layer thickness T _L are measured by the following methods.
Method of measuring the thickness of the sheet T _S is in a state of applying a load of 0.05kPa nonwoven to be measured, was measured using a thickness gauge. A laser displacement meter manufactured by OMRON Corporation was used as the thickness measuring instrument. The thickness was measured at 10 points, and the average value was calculated as the thickness.
Measurement of layer thickness T _L is to enlarge the cross section of the sheet at about 20 times by Keyence digital microscope VHX-900, you can measure the thickness of each layer.

The distance between the first convex portion 11 and the second convex portion 12 that are in the closest position when the nonwoven fabric 10B is viewed in plan may be adjusted as appropriate depending on the application, and the nonwoven fabric 10B can be used for absorbent articles such as diapers and sanitary products. When used as a top sheet, it is preferably from 1 mm to 15 mm, and more preferably from 3 mm to 10 mm. The basis weight of the nonwoven fabric 10B depends on the specific use of the nonwoven fabric 10B, but the average value of the entire nonwoven fabric 10B is preferably 15 g / m ² or more and 50 g / m ² or less, and 20 g / m ² or more and 40 g / m ² or less. Is more preferable.

  In the nonwoven fabric 10B of the second embodiment, the fiber density increases from the first convex portion top portion 11T toward the second convex top portion 12T in the thickness direction, and in addition, the first convex portion in the thickness direction. The hydrophilicity increases from the top portion 11T toward the second convex top portion 12T.

  In the nonwoven fabric 10B, compared with the 1st convex part top part 11T in the 1st surface 1a, the one part of the 2nd surface 1b has higher hydrophilicity. More specifically, when the hydrophilicity is seen along the thickness direction of the nonwoven fabric 10B, the hydrophilicity of the first convex portion top portion 11T is the lowest, and the hydrophilicity of the second convex portion top portion 12T is the highest. The hydrophilicity of the wall parts 13 and 14 located between the 1st convex part top part 11T and the 2nd convex part top part 12T is the hydrophilicity of the 1st convex part top part 11T, and the hydrophilicity of the 2nd convex part top part 12T. It is an intermediate value. Thus, in the nonwoven fabric 10B, the hydrophilicity is higher in the order of the first convex portion top portion 11T <the wall portion 13, 14 <the second convex portion top portion 12T. In this case, the hydrophilicity may be gradually increased in the order of the first convex portion top portion 11T <wall portion 13, 14 <second convex portion top portion 12T, or it is increased stepwise in a stepwise manner. May be. In order to give such a gradient of hydrophilicity to the nonwoven fabric 10B, the nonwoven fabric 10B may be manufactured according to the manufacturing method described later. The hydrophilicity is as described above. A low hydrophilicity is synonymous with a large contact angle, and a high hydrophilicity is synonymous with a small contact angle.

  Further, in the nonwoven fabric 10B, the second convex portion 12, that is, the concave portion in the first surface 1a, the portion corresponding to the bottom portion 12a in the second surface 1b as compared with the bottom portion 12a of the concave portion in the first surface 1a. The second convex portion top portion 12T is higher in hydrophilicity. In this case, the hydrophilicity may be continuously increased gradually in the order of the bottom portion 12a of the concave portion <the second convex portion top portion 12T, or may be increased stepwise.

  As described above, when the nonwoven fabric 10B is supplied with the liquid density gradient and the hydrophilicity gradient in the thickness direction of the nonwoven fabric 10B, the liquid is supplied to the first surface 1a side. Quickly penetrates through the nonwoven fabric 10B. Accordingly, it is difficult for the liquid to flow along the surface on the first surface 1a side. As a result, the liquid is less likely to remain on the surface on the first surface 1a side, which is the surface supplied with the liquid. And the liquid which permeate | transmitted the nonwoven fabric 10B becomes difficult to reverse. These remarkable effects become particularly remarkable when the nonwoven fabric 10B is used as a top sheet of an absorbent article having the first surface 1a as a skin facing surface.

  In particular, it is preferable that the first convex portion top portion 11T has higher hydrophilicity on the second surface 1b side than on the first surface 1a side. By doing so, the drawability of the liquid at the first convex portion top portion 11T is further increased, and when the liquid is supplied to the first surface 1a side of the nonwoven fabric 10B, the liquid quickly penetrates the nonwoven fabric 10B more quickly. become. From this viewpoint, the contact angle of water with respect to the fibers existing on the first surface 1a side in the first convex portion top portion 11T is preferably 65 degrees or more, particularly preferably 70 degrees or more, and 85 degrees or less, particularly 80 degrees or less. It is preferable. For example, the contact angle is preferably from 65 degrees to 85 degrees, and more preferably from 70 degrees to 80 degrees. On the other hand, the contact angle of water with respect to the fibers existing on the second surface 1b side in the first convex portion top portion 11T is smaller than the contact angle of water with respect to the fibers existing on the first surface 1a side in the first convex portion top portion 11T. Is preferably 65 ° or more, particularly preferably 70 ° or more, and preferably 85 ° or less, particularly preferably 80 ° or less. For example, the contact angle is preferably from 65 degrees to 85 degrees, and more preferably from 70 degrees to 80 degrees.

  From the viewpoint of making the above-described effect in the first convex portion top portion 11T more prominent, the contact angle of water with respect to the fibers existing on the first surface 1a side and the contact angle of water with respect to the fibers existing on the second surface 1b side are The difference (the former-the latter) is preferably 1 degree or more, preferably 20 degrees or less, particularly 10 degrees or less, and more preferably 4 degrees or less. For example, the difference in contact angle is preferably 1 degree or more and 20 degrees or less, more preferably 1 degree or more and 10 degrees or less, and still more preferably 1 degree or more and 4 degrees or less.

  Although the above description was the description regarding the 1st convex part top part 11T, it is preferable that it is as follows about the contact angles of the wall parts 13 and 14 and the 2nd convex part 12. FIG. On the condition that the contact angle of water with respect to the fibers present in the walls 13 and 14 is smaller than the contact angle of water with respect to the fibers present on the second surface 1b side of the first convex portion top 11T, particularly 60 degrees or more. It is preferably 65 degrees or more, preferably 80 degrees or less, and particularly preferably 75 degrees or less. For example, the contact angle is preferably 60 ° or more and 80 ° or less, and preferably 65 ° or more and 75 ° or less. When measuring the contact angle of water with respect to the fibers present in the walls 13 and 14, the fiber collection site is an intermediate position between the first convex top 11T and the second convex top 12T in the thickness direction of the nonwoven fabric 10B. And

  On the condition that the contact angle of water with respect to the fibers existing in the second convex portion 12 is smaller than the contact angle of water with respect to the fibers existing in the wall portions 13, 14, it should be 60 degrees or more, particularly 65 degrees or more. Preferably, it is 80 degrees or less, and particularly preferably 75 degrees or less. For example, the contact angle is preferably 60 degrees or more and 80 degrees or less, and more preferably 65 degrees or more and 75 degrees or less. When measuring the contact angle of water with respect to the fiber which exists in the 2nd convex part 12, the collection | recovery site | part of a fiber shall be a site | part on the 2nd surface 1b side of the 2nd convex part top part 12T.

  From the viewpoint of making the permeability of the liquid in the nonwoven fabric 10B and the anti-reverse property of the liquid once permeated more remarkable, the contact angle of water with respect to the fibers existing on the second surface 1b side in the first convex top 11T, The difference between the contact angle of water and the fibers present on the walls 13 and 14 (the former-the latter) is preferably 1 degree or more, particularly preferably 2 degrees or more, 20 degrees or less, particularly 10 degrees or less, and further 4 degrees. The following is preferable. For example, the difference in contact angle is preferably 1 to 20 degrees, more preferably 2 to 10 degrees, and still more preferably 1 to 4 degrees.

  From the same viewpoint, the difference between the contact angle of water with respect to the fibers present in the walls 13 and 14 and the contact angle of water with respect to the fibers present in the second convex portion 12 (the former-the latter) is preferably 1 degree or more, It is preferably 20 ° or less, particularly 7 ° or less, and more preferably 4 ° or less. For example, the difference in contact angle is preferably from 1 degree to 20 degrees, more preferably from 1 degree to 7 degrees, and still more preferably from 1 degree to 4 degrees.

  From the same viewpoint, the difference between the contact angle of water with respect to the fibers existing on the first surface 1a side in the first convex portion top portion 11T and the contact angle of water with respect to the fibers present in the second convex portion 12 (the former-the latter). Is preferably 2 ° or more, particularly preferably 4 ° or more, and preferably 20 ° or less, particularly preferably 10 ° or less. For example, the difference in contact angle is preferably 2 degrees or more and 20 degrees or less, more preferably 4 degrees or more and 10 degrees or less.

  From the same point of view, the bottom 12a of the concave portion on the first surface 1a and the second convex portion top portion 12T (the portion corresponding to the portion 12a on the second surface 1b) are such that the contact angle of the bottom portion 12a of the concave portion is the second convex portion. On the premise that the contact angle is higher than the top 12T, the difference in the contact angle of water with respect to the fiber is preferably 1 degree or more, more preferably 2 degrees or more, and preferably 20 degrees or less, more preferably 10 degrees. More specifically, the angle is preferably 1 degree or more and 20 degrees or less, more preferably 2 degrees or more and 10 degrees or less.

  Moreover, in the nonwoven fabric 10B, the adhesion amount of the fiber treatment agent containing the component (A), the component (B), and the component (C) described above is the ratio of the fiber to the total mass of the fiber excluding the fiber treatment agent. From the viewpoint of increasing the amount, it is preferably 0.1% by mass or more, more preferably 0.1% by mass or more and 1.5% by mass or less, and more preferably 0.2% by mass or more and 1.0% by mass or less.

  As described above, the nonwoven fabric 10B of the second embodiment is an air-through nonwoven fabric having a single layer structure, and as the constituent fiber, those usable in the nonwoven fabric 10A of the first embodiment can be used without any particular limitation. . That is, the nonwoven fabric 10B preferably includes a heat-fusible fiber that is one type of thermoplastic fiber, and particularly preferably includes a heat-fusible core-sheath composite fiber. Further, at least a part of the fibers (thermoplastic fibers) constituting the nonwoven fabric 10B may be heat-extensible fibers whose length is increased by heating, and the heat-extensible composite as a heat-fusible core-sheath-type composite fiber. Fiber can also be used.

  Next, one embodiment of the method for producing the nonwoven fabric 10B of the second embodiment will be described with reference to FIGS. FIG. 8 shows a manufacturing apparatus 100 suitably used for manufacturing the nonwoven fabric 10B. The manufacturing apparatus 100 is suitably used for manufacturing an air-through nonwoven fabric.

  As shown in FIG. 8, the manufacturing apparatus 100 includes a support body 110 that conveys a web 105 containing heat-fusible fibers. The web 105 is supplied to the surface of the support 110 by a feeding conveyor as the feeding unit 121. The web 105 is shaped by the support body 110, and the shaped web 105 is separated from the support body 110 and is sent out in a predetermined direction by a guide roller as a guide portion 122. The support 110 has a drum shape. Further, the support 110 is rotatable around the rotation shaft 110C. A driving device (not shown) is connected to the rotating shaft 110C. Details of the support 110 will be described later.

  On the outer surface side of the support 110, a first nozzle 111 that blows the first hot air W1 and a second nozzle 112 that blows the second hot air W2 are provided in this order along the supply direction of the web 105. The first nozzle 111 includes a heater 113. The first hot air W <b> 1 heated by the heater 113 is blown, for example, substantially perpendicularly to the surface of the support 10 through the air-permeable conveyor 123 having air permeability.

  The first nozzle 111 is provided with a spray hole (not shown) at its tip. The length of the spray hole is preferably 1 mm or more and 20 mm or less in the machine direction (MD) of the web 105, and the length in the width direction (CD) of the web 105 is equal to or greater than the width of the web 105 or a width for shaping. It is. The spray holes have a shape in which one or more rows of slit holes are formed, and round holes, long holes, and square holes are arranged in a staggered manner or in parallel in one or more rows. Preferably, it has a slit shape in a row of 2 mm or more and 20 mm or less. Since the spray holes of the first nozzle 111 are formed in this way, the first hot air W1 is sprayed at a uniform wind speed in the width direction of the surface of the web 105. As the first hot air W1, air, nitrogen or water vapor heated to a predetermined temperature by the heater 113 can be used. Preferably, air that does not cost is used.

  The first hot air W <b> 1 blown from the first nozzle 111 is controlled by the heater 113 to a temperature at which the fibers of the web 105 are temporarily fused so that the concavo-convex shape is maintained. For example, when the constituent fiber of the web 105 is a core-sheath type composite fiber having a low melting point component and a high melting point component having a higher melting point than the low melting point component, the first hot air W1 is used as the low melting point component of the fiber of the web 105. It is controlled to be hot air at a temperature of 60 ° C. lower than its melting point and 15 ° C. higher than its melting point. Preferably, the temperature is controlled to be not less than 50 ° C. lower than the melting point of the low melting point component and not more than 10 ° C. higher than the melting point of the low melting point component. For example, when polyethylene having a melting point of 132 ° C. is used as the low melting point component, a preferable temperature range is from 82 ° C. to 142 ° C., more preferably from 132 ° C. to 142 ° C.

  The wind speed of the 1st hot air W1 is adjusted suitably. Preferably, the wind speed is controlled to be 10 m / sec or more and 120 m / sec or less. If the wind speed of the first hot air W1 blown from the first nozzle 111 is too slow, the fibers are not sufficiently along the support 110, and the fusion of the fibers is weakened, so that shaping is difficult. On the other hand, it is difficult to form the web 105 even if the wind speed is too high. Therefore, the wind speed of the first hot air W1 is preferably in the above range. More preferably, it is 20 m / sec or more and 80 m / sec or less, and particularly preferably 40 m / sec or more and 60 m / sec or less.

  The aeration conveyor 123 supplies the web 105 to the feeding side along the surface of the support 110 while sandwiching the web 105 with the support 110. Specifically, a belt 124 having air permeability, a plurality of rollers 125 that support the belt 124, and a drive device (not shown) that drives the belt 124 via the rollers 125 are provided. At least two rollers 125 </ b> A and 125 </ b> B of the plurality of rollers 125 are arranged on the surface of the support 110 so that the belt 124 extends along the web 5. The ventilation conveyor 123 can prevent the web 105 from being disturbed and scattered by the first hot air W1 from the first nozzle 111.

  The second nozzle 112 includes a heater 114. The second hot air W2 heated by the heater 114 is blown, for example, substantially perpendicularly to the surface of the support 10. The second nozzle 112 is provided with a spray hole (not shown) at its tip. As the spray hole, it is desirable to use a punching metal that is regularly opened in the width direction and the flow direction. The open area ratio is preferably 10% or more and 40% or less, and more preferably 20% or more and 30% or less. Thus, since the blowing hole of the second nozzle 112 is formed, the second hot air W2 is blown at a uniform wind speed in the width direction of the surface of the web 105. As the second hot air W2, air, nitrogen, or water vapor heated by the heater 114 can be used. Preferably, air that does not cost is used.

  The second hot air W2 is controlled by the heater 114 to a temperature at which the fibers 105 of the web 105 are fused to fix the uneven shape while holding the uneven shape of the web 105 formed by the first hot air W1. ing. For example, when the constituent fiber of the web 105 is a core-sheath type composite fiber having a low melting point component and a high melting point component having a higher melting point than the low melting point component, the second hot air W2 is a low melting point component of the web 105 fiber. It is controlled to a temperature not lower than the melting point and lower than the melting point of the high melting point component of the fibers of the web 105, preferably 40 ° C. or higher than the melting point of the low melting point component. More preferably, it is controlled to a temperature not lower than the melting point of the low melting point component and not higher than 20 ° C. above this melting point, particularly preferably not lower than the melting point of the low melting point component and not higher than 15 ° C. above this melting point. For example, when polyethylene having a melting point of 132 ° C. is used as the low melting point component, a more preferable temperature range is from 132 ° C. to 152 ° C., particularly preferably from 132 ° C. to 147 ° C.

  The wind speed of the second hot air W2 blown from the second nozzle 112 is appropriately determined in consideration of the purpose. Preferably, the wind speed is controlled to 1 m / sec or more and 10 m / sec or less. If the wind speed of the second hot air W2 blown from the second nozzle 112 is too slow, heat transfer to the fiber may not be sufficient, and the fiber may be difficult to fuse and the uneven shape may be insufficiently fixed. On the other hand, if the wind speed is too high, the fiber will be too hot and the texture will tend to be poor. Therefore, the wind speed of the second hot air W2 is preferably in the above range. More preferably, it is 1 m / sec or more and 8 m / sec or less, and particularly preferably 2 m / sec or more and 4 m / sec or less.

  In the blowing direction of the first nozzle 111, a suction section 115 that sucks the first hot air W1 that has passed through the aeration conveyor 123, the web 105, and the support 110 is disposed. An exhaust device 117 that exhausts the sucked first hot air W <b> 1 is connected to the suction unit 115. Further, in the blowing direction of the second nozzle 112, a suction part 116 for sucking the second hot air W2 that has passed through the web 105 and the support 110 is disposed. The suction unit 116 is connected to an exhaust device 118 that exhausts the sucked second hot air W2. Any of the suction portions can have a structure in which the length in the CD direction can be appropriately adjusted. By arranging such suction portions 115 and 116, the web is prevented from being disturbed due to the rebound of the air to be blown, etc., and can be stably shaped into a desired shape. Further, the temperature around the drum is prevented from becoming too high, and the web 105 in contact with the drum is prevented from being excessively fused and hardened. Furthermore, it becomes easy to hold the web 105 on the support 110, and the conveyance becomes easy. In consideration of the stabilization of hot air temperature and the running cost of utilities, it is desirable to use hot air in a circulating manner.

FIG. 9 is an enlarged view of a main part of the support 110 in the manufacturing apparatus 100 shown in FIG. 9 corresponds to a state in which the support 110 having the shape of the peripheral surface of the drum in FIG. 8 is formed into a flat plate shape. The support 110 has a base 110B made of a plate-like body. A large number of through holes are formed in the base portion 110B, and the through holes serve as ventilation portions 110H that are concave portions. Moreover, the support body 110 has a plurality of protruding portions 110T that stand up from one surface of the base portion 110B. The protrusion 110T is located between the adjacent ventilation portions 110H. The protruding portions 110T and the ventilation portions 110H are alternately arranged along the A direction which is one direction in the plane of the support 110. Further, the protruding portions 110T and the ventilation portions 110H are alternately arranged along the B direction which is another direction in the plane of the support 110. The A direction and the B direction are orthogonal to each other. When viewed along the A direction, the distance d _A between the adjacent protruding portion 110T and the ventilation portion 110H, and when viewed along the B direction, the adjacent protruding portion 110T and the ventilation portion 110H the distance d _B between may also good, or the same as or different. The A direction coincides with the rotation direction of the support 110, and the B direction coincides with the width direction of the support 110. Thus, the support body 110 has an uneven structure on one surface of the base portion 110B.

  The protruding portion 110T has a shape that tapers toward the tip, and the tip is rounded. The protruding portion 110T has, for example, a plate shape or a spindle shape. The height of the protruding portion 110T can be appropriately set according to the use, standard, etc. of the nonwoven fabric 10B. The height H of the protrusion 110T (see FIG. 9), that is, the height based on the upper surface of the base 110B is preferably 3 mm to 30 mm, more preferably 3 mm to 10 mm. The pitch of the protrusions 110T is preferably 6 mm to 15 mm, more preferably 6 mm to 10 mm in the A direction, and preferably 4 mm to 8 mm, and more preferably 4 mm to 6 mm in the B direction.

  The ventilation portion 110H of the support 110 is composed of a plurality of openings formed in the support 110, and the opening ratio is preferably 20% or more and 45% or less, more preferably 25% or more with respect to the surface area of the support 110. It is set to 40% or less, more preferably 30% to 35%. By setting the aperture ratio within this range, a sufficient uneven shape can be formed on the web 105, and the deterioration of the shaped shape and the formation of fluff are effectively prevented. The shape of the ventilation portion 110H can be, for example, a circle in plan view. However, the shape of the ventilation part 110H is not limited to this, and other shapes such as an ellipse, a polygon, or a combination thereof may be employed.

  FIG. 10 schematically shows a state in which the web 105 is shaped using the support 110. In addition, illustration of the aeration conveyor 123 is abbreviate | omitted in FIG. In a state where the web 105 is placed on the support 110, the first hot air W1 is blown from the outer surface of the web 105. The blown first hot air W1 passes through the web 105, further passes through the ventilation portion 110H of the support 110, and is sucked by the suction portion 115 (see FIG. 8). Thus, the 1st hot air W1 is sprayed with respect to the web 105 by an air through system.

  A portion of the web 105 spanned by two or more adjacent projecting portions 110T receives pressure by the blowing of the first hot air W1 and deforms downward. The protrusion 11A is formed by this deformation. 11 A of protrusion parts are the site | parts corresponding to the 1st convex part 11 in the target nonwoven fabric 10B. In the protrusion 11 </ b> A, the closer to the bottom, the greater the degree of deformation due to the pressure due to the blowing of the first hot air W <b> 1, and as a result, the inter-fiber distance becomes larger than the second protrusion 12. . In other words, the fiber density is reduced.

  On the other hand, even if the portion of the web 105 supported by the protruding portion 110T receives pressure due to the blowing of the first hot air W1, the downward deformation is suppressed by the restriction by the protruding portion 110T. As a result, the portion supported by the protruding portion 110T has a convex shape with a skirt extending downward. This convex-shaped part is a part corresponding to the second convex part 12 in the target nonwoven fabric 10B. At the highest position of the convex portion, the inter-fiber distance is small. In other words, the fiber density is increased. On the other hand, since the web 105 is deformed at the base of the convex portion, the interfiber distance is larger than that of the first convex portion 11. In other words, the fiber density is reduced. However, it does not become as small as the fiber density of the protrusion 11A (see FIG. 10) described above.

  As described above, a gradient is generated in the fiber density along the thickness direction of the shaped web 105 by the blowing of the first hot air W1. This gradient is a gradient in which the fiber density decreases from the surface to which the first hot air W1 is blown toward the opposite surface. In FIG. 10, what is indicated by a two-dot chain line is the fiber web 105 after shaping.

  In this manufacturing method, a gradient occurs in the fiber density along the thickness direction of the shaped web 105, and at the same time, a gradient also occurs in the hydrophilicity along the thickness direction of the shaped web 105. The reason is as follows. According to the blowing of the first hot air W1, the protruding portion 11A, which is a portion of the web 105 that has been deformed under the pressure of the blowing of the first hot air W1, has the largest amount of passage of the first hot air W1. . In other words, it receives the largest amount of heat. As a result, in the protruding portion 11A, the degree of penetration of the fiber treatment agent into the fiber increases, and as a result, the hydrophilicity is lower than before the first hot air W1 is blown. On the other hand, the portion of the support 110 that is supported by the protrusion 110T is relatively less deformed by the blowing of the first hot air W1 than the protrusion 11A, and therefore the first hot air W1 passes by that much. The amount is relatively small. Due to this, in the portion supported by the protrusion 110T, the degree of penetration of the fiber treatment agent into the fiber becomes relatively small, and as a result, compared with before the first hot air W1 is blown. The degree of decrease in hydrophilicity is reduced.

  As described above, the lower the degree of hydrophilicity the closer to the base 110B in the web 105 due to the blowing of the first hot air W1, the greater the degree of hydrophilicity the closer to the part supported by the protrusion 110T. The gradient of hydrophilicity that the degree of decrease becomes small appears.

  FIG. 11 shows a state in which the target nonwoven fabric 10B is obtained by blowing the second hot air W2 to the shaped web 105 and fusing the intersections of the constituent fibers. The second hot air W2 is blown by an air-through method.

  10C of nonwoven fabrics of 3rd Embodiment are comprised including a thermoplastic fiber, and as shown in FIG.12 and FIG.13, the 2nd part 22 with thickness thinner compared with the 1st part 21 and the 1st part 21 Are alternately formed, and the first portion 21 forms a ridge portion 23 as a convex portion and the second portion 22 forms a groove portion 24 as a concave portion on the first surface 1a. In the nonwoven fabric 10 </ b> C, the first surface 1 a is a concavo-convex surface formed with the ridges 23 and the grooves 24, whereas the second surface 1 b is flat or concavo-convex as compared to the concavo-convex surface. The degree of is clearly small. The nonwoven fabric 10C is a nonwoven fabric having a single layer structure.

  The first part 21 and the second part 22 are each formed to extend in one direction Y of the nonwoven fabric 10C, and are formed in parallel to each other. In addition, a plurality of first portions 21 and second portions 22 are formed, and are alternately formed in a direction X orthogonal to the one direction Y. Similarly, the ridge portions 23 and the groove portions 24 are each formed so as to extend in one direction Y of the nonwoven fabric 10C, are formed in parallel to each other, and a plurality of each are formed, and a direction X orthogonal to the one direction Y is formed. Are alternately formed. The convex portion 23 has a constant height in the one direction Y, and the groove portion 24 has a constant depth in the one direction Y. In addition, the ridge portion 23 has a semicircular cross section.

  In the nonwoven fabric 10C of the third embodiment, the fiber density of the second part 22 is lower than the fiber density of the first part 21. Further, the hydrophilicity of the second portion 22 is lower than the hydrophilicity of the top portion Q <b> 1 of the ridge portion 23 of the first portion 21. The hydrophilicity is as described above. A low hydrophilicity is synonymous with a large contact angle, and a high hydrophilicity is synonymous with a small contact angle.

  In the nonwoven fabric 10C, when a liquid is supplied to the first surface 1a side, a part of the liquid moves to the groove portion 24 (concave portion), but as described above, the second portion 22 that forms the groove portion 24 When the fiber density is lower than the fiber density of the first part 21 forming the ridges 23 (convex parts), the liquid that has moved to the groove part 24 passes through the gaps of the fibers in the second part 22, and the second surface. Quickly penetrates to the 1b side. Moreover, when the hydrophilicity of the second part 22 is lower than the hydrophilicity of the first part 21, in particular the hydrophilicity of the top part Q <b> 1 of the ridge part 23, the liquid transferred to the second surface 1 b side has a fiber density. Transition to the first surface 1a side through the low second portion 22 is also prevented. Thereby, the nonwoven fabric 10 </ b> C is such that the liquid hardly remains on the surface of the first surface 1 a having the ridges 23 and the grooves 24. These effects become even more remarkable when the nonwoven fabric 10C is used as a top sheet of an absorbent article so that the first surface 1a side faces the wearer's skin. When used as a top sheet of an absorbent article, the liquid easily moves to the second surface 1b side via the second portion 22 and is difficult to return to the first surface 1a side. From the viewpoint of reducing the contact of the liquid and preventing the discomfort such as stickiness from occurring, and the viewpoint of preventing the appearance of colored liquid such as menstrual blood and improving the appearance of the absorbent article after liquid absorption To preferred.

From the viewpoint of facilitating the transfer of the liquid to the second surface 1b side via the second part 22, the fiber density (d2) of the second part 22 is the ratio (%) to the fiber density (d1) of the first part 21. , Preferably 80% or less, more preferably 70% or less, preferably 5% or more, more preferably 10% or more, and preferably 5% or more and 80% or less, more preferably 10%. % To 70%.
From the same viewpoint, the fiber density (d1) of the first part 21 is preferably 0.10 g / cm ³ or less, more preferably 0.07 g / cm ³ or less, and preferably 0.01 g / cm ^3. More preferably, it is 0.02 g / cm ³ or more, preferably 0.01 g / cm ³ or more and 0.10 g / cm ³ or less, more preferably 0.02 g / cm ³ or more and 0.07 g / cm ^3. It is as follows.

[Method for measuring fiber density of first part and second part]
First, the measurement target portion of the fiber density is cut out from the nonwoven fabric to be measured to obtain a measurement sample. In the measurement sample, the length direction of the groove portion (concave portion) is 50 mm, and the width direction orthogonal to the length direction is also 50 mm. When the width of the measurement sample is narrow, a plurality of portions of the nonwoven fabric are cut out with a cutter or the like so that the total is 50 mm. The weight per unit area of the measurement sample is measured from the total weight. Next, after freezing the measurement sample in liquid nitrogen, it is cut in the X direction of FIG. 1 with a cutter. Next, the thickness (mm) of the cross section of the portion to be measured is measured from a photograph (magnification 20 times) of the cut surface taken with a microscope. The value obtained by dividing the weight per unit area of the measurement sample by the thickness of the cross section of the measurement sample is defined as the fiber density.

  From the viewpoint of making it easier for the liquid to move to the second surface 1b side via the second part 22 and making it difficult for the transferred liquid to return to the first surface 1a side, the second part 22 has a water contact angle with respect to the fibers. , Preferably 60 degrees or more, more preferably 65 degrees or more, preferably 80 degrees or less, more preferably 75 degrees or less, preferably 60 degrees or more and 80 degrees or less, more preferably 65 degrees or more. It is 75 degrees or less. From the same point of view, the second portion 22 and the top portion Q1 of the convex portion 23 of the first portion 21 are water on the fiber on the assumption that the contact angle of the second portion 22 is higher than the contact angle of the top portion Q1. The contact angle difference is preferably 1 degree or more, preferably 10 degrees or less, more preferably 5 degrees or less, preferably 1 degree or more and 10 degrees or less, more preferably 1 degree or more and 5 degrees or less. Less than or equal to degrees.

  In addition, about the 2nd part 22, the fiber for measuring the contact angle of the water with respect to a fiber is extract | collected from the surface site | part Q4 located in the thickness direction of the 2nd part 22 on the opposite side to the 2nd surface 1b. Moreover, about the 1st part 21, the fiber for measuring the contact angle of the water with respect to a fiber is extract | collected from the top part Q1 about the top part Q1, and this top part Q1 on the 2nd surface 1b of 10 C of nonwoven fabrics about the bottom part Q3. The intermediate part Q2 is collected from a part of the first part 21 that bisects between the top part Q1 and the bottom part Q3.

  Moreover, as for the nonwoven fabric 10C of 3rd Embodiment, as above-mentioned, the 1st part 21 is the 1st surface 1a side on the opposite side to the 1st surface 1a side from which this protruding item | line part 23 protrudes from the top part Q1 of the protruding item | line part 24. The hydrophilicity has a gradient toward the bottom Q3 on the second surface 1b. That is, the first portion 21 of the nonwoven fabric 10C has a bottom portion when the hydrophilicity of the top portion Q1 of the ridge portion 23, the bottom portion Q3 on the second surface 1b (the portion corresponding to the top portion Q1), and the intermediate portion Q2 is compared. Q3 has the highest hydrophilicity, the intermediate portion Q2 has the next highest hydrophilicity, and the top Q1 has the lowest hydrophilicity. That is, in the nonwoven fabric 10C, the hydrophilicity is higher in any part of the second surface 1b than in the top portion Q1 of the ridges 23 (convex portions) on the first surface 1a.

  In the nonwoven fabric 10C of the third embodiment, the portion Q4 ′ corresponding to the bottom Q4 of the groove 24 on the second surface 1b is more hydrophilic than the bottom Q4 of the groove 24 (concave) on the first surface 1a. The degree is getting higher. More specifically, in the second portion 22, the hydrophilicity gradually increases from the first surface 1a side toward the second surface 1b side.

  In the nonwoven fabric 10C, when the liquid is supplied to the first surface 1a side, as described above, a part of the liquid moves to the groove part 24 (recessed part), but the first part 21 is also hydrophilic in the thickness direction. Each time, due to the provision of such a gradient, another part of the supplied liquid is taken into the ridges 23 from the surface of the ridges 23 (projections) and is hydrophilic. Due to the gradient of the degree, the taken-in liquid is guided from the top Q1 of the ridge 23 toward the bottom Q3. Therefore, the liquid absorbed from the surface of the ridge 23 can be smoothly guided to a position away from the top Q1 in the nonwoven fabric 10C, and the liquid hardly remains near the top Q1 of the ridge 23 or near the intermediate portion Q2. . These effects become even more remarkable when the nonwoven fabric 10C is used as a top sheet of an absorbent article so that the first surface 1a side faces the wearer's skin. When used as a top sheet of an absorbent article, it is difficult for the liquid to remain near the top Q1 of the ridge 23 or the intermediate portion Q2, which quickly isolates the liquid from the surface of the wearer's skin. Thus, it is preferable from the viewpoint of preventing discomfort such as stickiness, and preventing colored liquids such as menstrual blood from being noticeable and improving the appearance of the absorbent article after liquid absorption.

From the viewpoint of smoothly transferring the liquid taken in from the surface of the ridge 23 to the bottom Q3, the first part 21 assumes that the contact angle of the top Q1 is larger than the contact angle of the bottom Q3. The difference between the bottom Q3 and the contact angle of water with respect to the fiber is preferably 1 degree or more, more preferably 4 degrees or more, preferably 15 degrees or less, more preferably 10 degrees or less, and preferably Is from 1 degree to 15 degrees, more preferably from 4 degrees to 10 degrees.
Further, on the premise that the contact angle of the top portion Q1 is larger than the contact angle of the intermediate portion Q2, the difference between the contact angle of water with respect to the fiber is preferably 1 degree or more, more preferably, between the top portion Q1 and the intermediate portion Q2. It is 2 degrees or more, preferably 1 degree or more and 10 degrees or less, more preferably 2 degrees or more and 5 degrees or less.
Further, on the premise that the contact angle of the bottom Q3 is larger than the contact angle of the intermediate part Q2, the intermediate part Q2 and the bottom Q3 have a difference in the contact angle of water with respect to the fibers, preferably 1 degree or more, and more preferably 2 It is preferably at least 1 degree and at most 10 degrees, more preferably at least 2 degrees and at most 5 degrees.

  From the same point of view, the bottom Q4 of the groove 24 (concave portion) on the first surface 1a and the portion Q4 ′ corresponding to the bottom Q4 of the groove 24 on the second surface 1b have a contact angle of the bottom Q4 of the groove 24 of the portion Q4. The difference in the contact angle of water with respect to the fiber is preferably 1 degree or more, more preferably 2 degrees or more, and preferably 20 degrees or less, more preferably 10 degrees or less, assuming that the contact angle is higher than '. More specifically, it is preferably 1 to 20 degrees, more preferably 2 to 10 degrees.

  Regardless of whether the degree of hydrophilicity is gradually increased or stepwise, in the first part 21, the contact angle of water with respect to the fibers present at the top Q1 of the ridge 23 is 60 degrees or more, in particular It is preferably 65 ° or more, 80 ° or less, particularly preferably 75 ° or less, 60 ° or more and 80 ° or less, and more preferably 65 ° or more and 75 ° or less. . In addition, the contact angle of water with respect to the fibers present in the bottom Q3 of the first part 21 is preferably 50 degrees or more, particularly 55 degrees or more, 75 degrees or less, particularly preferably 70 degrees or less, It is preferably 50 degrees or more and 75 degrees or less, and preferably 55 degrees or more and 70 degrees or less.

  From the viewpoint of ensuring that one or more of the effects described above are more reliably achieved and from the viewpoint of further improving the performance of the nonwoven fabric 10C, the hydrophilicity of the second portion 22 is such that the bottom portion Q3 of the first portion 21 has a hydrophilicity. It is preferably lower than the degree of hydrophilicity, and the difference between the contact angle of water and the fiber between the second part 22 and the bottom part Q3 of the first part 21 is preferably 1 degree or more, more preferably 5 degrees or more, It is preferably 15 degrees or less, more preferably 10 degrees or less, preferably 1 degree or more and 15 degrees or less, more preferably 5 degrees or more and 10 degrees or less.

  In addition, from the viewpoint of ensuring that one or more of the effects described above are more reliably achieved and from the viewpoint of further improving the performance of the nonwoven fabric 10C, the thickness t2 of the second portion 22 is the thickness of the first portion 21. The ratio (%) to t1 is preferably 80% or less, more preferably 70% or less, preferably 20% or more, and more preferably 30% or more. Further, the thickness t2 of the second portion 22 is preferably 1.2 mm or less, more preferably 0.8 mm or less, preferably 0.2 mm or more, and more preferably 0.4 mm or more.

  From the same viewpoint, the difference t3 between the thickness t1 of the first portion 21 and the thickness t2 of the second portion 22, in other words, the height of the ridge 23 or the depth of the groove 24 is the thickness of the first portion 21. For t1, it is preferably 10% or more, more preferably 20% or more, preferably 80% or less, more preferably 70% or less, and preferably 10% or more and 80% or less, More preferably, it is 20% or more and 70% or less.

  From the same viewpoint, the difference t3 between the thickness t1 of the first part 21 and the thickness t2 of the second part 22 is preferably 0.1 mm or more, more preferably 0.2 mm or more, and preferably 1.0 mm. Hereinafter, it is more preferably 0.8 mm or less, preferably 0.1 mm or more and 1.0 mm or less, more preferably 0.2 mm or more and 0.8 mm or less.

[Method for measuring thickness of first part and thickness of second part]
In order to measure the thickness of the first part 21 and the second part 22, the nonwoven fabric to be measured is frozen in liquid nitrogen and then cut in the X direction of FIG. 12 with a cutter. Next, the thickness is measured from a photograph of the cross section taken with a microscope. The magnification of this photograph shall be 20 times or more.

Further, in the nonwoven fabric 10C, the width W1 of the ridges 23 (projections) is preferably 0.5 mm or more, more preferably 0.8 mm or more, and preferably 10.0 mm or less, more preferably 6. It is 0 mm or less, preferably 0.5 mm or more and 10.0 mm or less, more preferably 0.8 mm or more and 6.0 mm or less.
Further, in the nonwoven fabric 10C, the width W2 of the groove 24 (concave portion) is preferably 0.2 mm or more, more preferably 0.4 mm or more, and preferably 3.0 mm or less, more preferably 2.0 mm or less. And preferably 0.2 mm or more and 3.0 mm or less, more preferably 0.4 mm or more and 2.0 mm or less.

  The constituent fibers (thermoplastic fibers) of the nonwoven fabric 10C are fused by an air-through method at the intersections of the fibers. In addition, the constituent fibers of the nonwoven fabric 10C may be bonded by means other than air-through fusion. For example, they may be additionally bonded by means such as fusion by hot embossing, entanglement by a high-pressure jet stream, or adhesion by an adhesive.

  In addition, in the nonwoven fabric 10C, the adhesion amount of the fiber treatment agent containing the component (A), the component (B) and the component (C) described above is determined by the ratio of the total amount of fibers excluding the fiber treatment agent to the hydrophilicity of the fiber. From the viewpoint of increasing the amount, it is preferably 0.1% by mass or more, more preferably 0.1% by mass or more and 1.5% by mass or less, and more preferably 0.2% by mass or more and 1.0% by mass or less.

  As a method for attaching the fiber treatment agent to the surface of the heat-fusible fiber, various known methods can be employed without any particular limitation. For example, application by spraying, application by a slot coater, application by roll transfer, immersion in a fiber treatment agent, and the like can be mentioned. These treatments may be performed on the fibers before being formed into a web, or may be performed after the fibers are formed into a web by various methods. However, it is necessary to perform processing before air-through processing described later. The fiber having the fiber treatment agent attached to the surface is dried at a temperature sufficiently lower than the melting point of the polyethylene resin (for example, 120 ° C. or less) by, for example, a hot air blowing type dryer.

  As described above, the nonwoven fabric 10C according to the third embodiment is an air-through nonwoven fabric having a single-layer structure, and as the constituent fiber, those usable in the nonwoven fabric 10A according to the first embodiment can be used without any particular limitation. . That is, the nonwoven fabric 10C preferably includes a heat-fusible fiber that is a kind of thermoplastic fiber, and particularly preferably includes a heat-fusible core-sheath composite fiber. Further, at least a part of the fibers (thermoplastic fibers) constituting the nonwoven fabric 10C may be heat-extensible fibers whose length is increased by heating, and the heat-extensible composite as a heat-fusible core-sheath composite fiber. Fiber can also be used.

  The nonwoven fabric 10C of 3rd Embodiment can be easily manufactured with the manufacturing method of the nonwoven fabric which comprises a web formation process, an uneven | corrugated formation process, and a hot-air treatment process, for example. In the web forming step, a fiber web is formed which includes, as constituent fibers, heat-fusible fibers having a fiber treatment agent attached to the surface. As a method for forming the fiber web, various known methods such as a card method, an airlaid method, and a spunbond method can be used. The fiber web is typically of uniform thickness. The fiber treatment agent is preferably attached at the fiber stage because the fiber treatment agent can be distributed in the thickness direction and the planar direction, but may be attached by an appropriate method after the formation of the fiber web. A particularly preferable method is a method in which the heat-fusible fiber having the fiber treatment agent attached to the surface thereof is applied to a card machine to form a fiber web. The fiber web formed by the card method using a card machine is easy to form unevenness by rearranging the fibers in the unevenness forming step.

  In the unevenness forming step, fluid such as air is jetted from the jet nozzle to the fiber web obtained in the web forming step, and the fiber on the surface of the fiber web is moved by the pressure, and one side of the fiber web An uneven surface having a ridge and a groove is formed. A belt-shaped fiber web is formed in the web forming process, and in the unevenness forming process, fluid is discharged from a plurality of jet nozzles arranged intermittently in a direction orthogonal to the transport direction while transporting the fiber web in the longitudinal direction. It is preferable to form ridges 23 (convex portions) and groove portions 24 (concave portions) that are jetted and continuously extend along the conveying direction of the fiber web. The fluid to be ejected onto the fiber web is preferably a gas such as air or nitrogen. Or what contains liquid vapor | steams, such as water vapor | steam, can be illustrated. In addition, solid or liquid fine particles may be included in the gas. The gas blown against the fiber web is preferably a temperature at which the heat-fusible fiber constituting the fiber web does not melt, and the resin melting point constituting the fiber plus less than 50 degrees is in the course of forming the groove. This is preferable from the viewpoint of preventing the fibers from fusing and preventing the formation of the groove. In order to improve the moldability of the groove (irregularity) and the like, it is desirable that the temperature is at least the softening point of the thermoplastic fiber constituting the fiber assembly in order to soften the fiber and form the irregularity.

  In the hot-air treatment process, as shown in FIG. 14, the fiber web 10C ′ after the formation of the unevenness is transported while being placed on a breathable transport means made of a heat-resistant net 300 or the like with the uneven surface facing upward. Then, hot air 301 is blown onto the fiber web 10C ′ from above. For blowing hot air, it is preferable to use an air-through hot air processing apparatus that allows hot air to pass therethrough.

  In this manufacturing method, the unevenness is formed by rearranging the fibers in the unevenness forming step described above, and the fiber density of the second portion equivalent portion 22 ′ having the recesses is reduced. A large amount of hot air circulates in comparison with the first portion equivalent portion 21 ′ having the ridge portion at 22 ′. Thereby, in the obtained nonwoven fabric 10C, the hydrophilicity of the second portion 22 is lower than the hydrophilicity of the top portion Q1 of the first portion 21 and the like. Further, the first portion corresponding portion 21 ′ of the fiber web 10 C ′ has the greatest degree of decrease in hydrophilicity because the amount of heat received decreases from the blowing surface to which the hot air is blown toward the opposite net surface. The top Q1, the smallest but the bottom Q3. Therefore, the first portion 21 of the obtained nonwoven fabric 10C has the highest hydrophilicity at the bottom Q3, the next hydrophilicity at the intermediate portion Q2, and the lowest hydrophilicity at the top Q1. The nonwoven fabric 10C of the third embodiment obtained in this manner may then be subjected to secondary processing. Examples of the secondary processing include known three-dimensional shaping processing, embossing processing, calendar processing, and opening processing.

  FIG. 15 shows a nonwoven fabric 10C1 that is a modification of the nonwoven fabric 10C of the third embodiment. The nonwoven fabric 10 </ b> C <b> 1 is an air-through nonwoven fabric and has a multilayer structure including the first layer 10 and the second layer 20. The first layer 10 and the second layer 20 are adjacent and in direct contact with each other, and no other layer is interposed between the two layers. The non-woven fabric 10C1 includes the first layer 10 and the second layer 20 of the heat-fusible fibers (thermoplastic fibers) to which the fiber treatment agent containing the components (A), (B), and (C) described above is attached. However, it may be included in only one of the first layer 10 and the second layer 20.

The fineness of the heat-fusible fiber may be the same between the first layer 10 and the second layer 20, or may be different. When the fineness of the heat-fusible fiber in each of the layers 10 and 20 is different, the fineness of the heat-fusible fiber contained in the second layer 20 is greater than the fineness of the heat-fusible fiber contained in the first layer 10. Is preferably large.
The non-woven fabric 10C1 having a multilayer structure including the first layer 10 and the second layer 20 is manufactured by manufacturing a laminated web in which the first web and the second web are overlapped in the web forming process. Can be manufactured in the same manner as the manufacturing method of the nonwoven fabric 10C described above except that the fluid such as gas is jetted from the above, but when the fluid is sprayed, the fineness of the first web on the first layer side is reduced. In other words, the fibers of the first web, which are fine and dense, are easy to move from the portion that becomes the groove due to the pressure of the fluid, whereas the fibers of the second web, which is thick and sparse, are difficult to move, so the groove 24 The inter-fiber distance in the second part 22 that forms the line is further increased. Thereby, the nonwoven fabric which was further excellent in the permeability | transmittance of the liquid through the 2nd part 22 is obtained.

The fineness of the second layer 20 is preferably 1 dtex or more, more preferably 2 dtex or more, from the viewpoint of liquid permeability, and preferably 7 dtex or less, more preferably 6 dtex or less, from the viewpoint of preventing liquid return of the transmitted liquid. . Further, the difference between the fineness of the second layer 20 and the fineness of the first layer 10 is preferably 1 dtex or more, more preferably 2 dtex or more, and preferably 5 dtex or less, more preferably 4 dtex or less.
Similarly to the nonwoven fabric 10C shown in FIG. 12, the nonwoven fabric 10C1 shown in FIG. 15 has the fiber density of the second part 22 lower than the fiber density of the first part 21, and the hydrophilicity of the second part 22 However, it is lower than the hydrophilicity of the top portion Q1 of the ridge portion 23 of the first portion 21. Further, the first portion 21 of the nonwoven fabric 10C1 also has the highest hydrophilicity of the bottom portion Q3 when comparing the hydrophilicity of the top portion Q1 of the ridge 23, the bottom portion Q3 on the second surface 1b, and the intermediate portion Q2, The intermediate part Q2 has the next highest hydrophilicity, and the top part Q1 has the lowest hydrophilicity. Therefore, also in the nonwoven fabric 10C1, the fiber density of the second part 22 is lower than the fiber density of the first part 21 as described above. Further, the hydrophilicity of the second portion 22 is lower than the hydrophilicity of the top portion Q <b> 1 of the ridge portion 23 of the first portion 21. Therefore, the same effect as the nonwoven fabric 10C is exhibited also by the nonwoven fabric 10C1.

  The uneven nonwoven fabric (nonwoven fabrics 10A, 10B, and 10C) of the present invention can be applied to various fields by taking advantage of the gradient of hydrophilicity along the uneven shape. For example, surface sheets and second sheets (sheets disposed between the surface sheet and the absorbent body) in absorbent articles used for absorbing liquid discharged from the body such as sanitary napkins, panty liners, disposable diapers, and incontinence pads , A back sheet, a leak-proof sheet, or a personal wipe sheet, a skin care sheet, and an objective wiper. When using the uneven | corrugated nonwoven fabric of this invention as a surface sheet or a second sheet | seat of an absorbent article, it is preferable to arrange | position so that an uneven surface (1st surface) may face a wearer's skin.

  An absorbent article used for absorbing liquid discharged from the body typically includes a top sheet, a back sheet, and a liquid-retaining absorbent body interposed between both sheets. As the absorbent body and the back sheet when the uneven nonwoven fabric of the present invention is used as the top sheet, materials usually used in the technical field can be used without particular limitation. For example, as the absorbent body, a fiber assembly made of a fiber material such as pulp fiber or a fiber assembly in which an absorbent polymer is held can be coated with a covering sheet such as tissue paper or nonwoven fabric. As the back sheet, a liquid-impermeable or water-repellent sheet such as a thermoplastic resin film or a laminate of the film and a nonwoven fabric can be used. The back sheet may have water vapor permeability. The absorbent article may further include various members depending on the specific application of the absorbent article. Such members are known to those skilled in the art. For example, when the absorbent article is applied to a disposable diaper or a sanitary napkin, a pair or two or more pairs of three-dimensional guards can be disposed on the left and right sides of the skin facing surface of the topsheet.

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to embodiment mentioned above, It can change suitably. All the parts of only the one embodiment described above can be used together as appropriate. The present invention further discloses the following embodiments with respect to the above-described embodiments.

<1>
It is comprised including a thermoplastic fiber, has a 1st surface and the 2nd surface located on the opposite side, and at least 1st surface is between the several convex part which protrudes in the 1st surface side, and this convex part. It is an uneven nonwoven fabric having unevenness consisting of a recessed portion located,
The fiber treatment agent is attached,
The uneven | corrugated nonwoven fabric in which the said fiber treatment agent contains the following (A) component, (B) component, and (C) component.
(A) Polyorganosiloxane (B) Phosphate ester type anionic surfactant (C) Polyoxyalkylene-modified polyhydric alcohol fatty acid ester

<2>
The uneven nonwoven fabric according to <1>, wherein the polyorganosiloxane is at least one selected from the group consisting of polydimethylsiloxane, polydiethylsiloxane, and polydipropylsiloxane.
<3>
The content of the polyorganosiloxane in the fiber treatment agent is preferably 1% by mass or more, more preferably 5% by mass or more, and preferably 30% by mass or less, based on the total mass of the fiber treatment agent. More preferably 20% by mass or less, more specifically, preferably 1% by mass or more and 30% by mass or less, more preferably 5% by mass or more and 20% by mass or less, as described in <1> or <2>. Non-woven fabric.

<4>
The phosphoric acid ester type anionic surfactant is any one of <1> to <3>, wherein the carbon chain has a completely neutralized or partially neutralized salt of a mono- or dialkyl phosphate ester having 16 to 18 carbon chains. The uneven nonwoven fabric described.
<5>
The content of the phosphate ester type anionic surfactant in the fiber treatment agent is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably based on the total mass of the fiber treatment agent. The uneven nonwoven fabric according to any one of <1> to <4>, wherein is 30% by mass or less, more preferably 25% by mass or less.

<6>
The polyoxyalkylene-modified polyhydric alcohol fatty acid ester is a polyoxyethylene (POE) -modified polyhydric alcohol fatty acid ester or a polyhydric alcohol fatty acid ester castor oil, wherein the alkylene oxide added to the polyhydric alcohol fatty acid ester is ethylene oxide. The uneven nonwoven fabric according to any one of <1> to <5>, which is POE-modified castor oil (POE-modified cured castor oil), which is (cured castor oil).
<7>
The content of the polyoxyalkylene-modified polyhydric alcohol fatty acid ester in the fiber treatment agent is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably with respect to the total mass of the fiber treatment agent. Is an uneven nonwoven fabric according to any one of <1> to <6>, which is 20% by mass or less, more preferably 15% by mass or less.

<8>
In the fiber treatment agent, the content ratio of the polyorganosiloxane and the (C) polyoxyalkylene-modified polyhydric alcohol fatty acid ester is a mass ratio, preferably the former: the latter = 1: 2 to 3: 1, more preferably. Is the uneven nonwoven fabric according to any one of <1> to <7>, wherein the former: the latter = 1: 1 to 2: 1.
<9>
In the fiber treatment agent, the content ratio of the polyorganosiloxane and the phosphate ester type anionic surfactant is a mass ratio, preferably the former: the latter = 1: 5 to 10: 1, more preferably the former: The uneven nonwoven fabric according to any one of <1> to <8>, wherein the latter is 1: 2 to 3: 1.

<10>
The uneven nonwoven fabric according to any one of <1> to <9>, wherein any part of the second surface has higher hydrophilicity than the top of the protrusion on the first surface.
<11>
The uneven nonwoven fabric according to any one of <1> to <10>, wherein the portion corresponding to the bottom portion on the second surface has higher hydrophilicity than the bottom portion of the concave portion on the first surface.
<12>
The uneven nonwoven fabric according to any one of <1> to <11>, wherein at least a part of the thermoplastic fiber is a heat-extensible fiber.
<13>
In the absorbent article provided with the absorber and the surface sheet distribute | arranged to the skin opposing surface side of this absorber, the uneven | corrugated nonwoven fabric of any one of said <1>-<12> is used as this surface sheet. And the absorbent article arrange | positioned so that the 1st surface of this uneven | corrugated nonwoven fabric may face a wearer's skin.

<14>
It has a multilayer structure in which a plurality of layers are laminated in the thickness direction,
In the multilayer structure, the first nonwoven fabric that forms the first surface and the second nonwoven fabric that forms the second surface are partially heat-sealed, and a large number of joints are formed as recesses on the first surface. In addition, the first nonwoven fabric projects in a direction away from the second nonwoven fabric in a non-joined portion surrounded by the joined portion, and forms a number of hollow convex portions. <1> to <12> The uneven nonwoven fabric according to any one of the above.
<15>
The uneven nonwoven fabric according to <14>, wherein the fiber treatment agent is contained only in the second nonwoven fabric.
<16>
<14> or <15> in which the portion corresponding to the portion on the second surface has higher hydrophilicity than the portion on the first surface side in the joint portion (the bottom portion of the concave portion on the first surface). The uneven nonwoven fabric described.
<17>
In the first nonwoven fabric, the hydrophilicity at the top of the convex portion is lower than the hydrophilicity of the distal portion where the distance between the second nonwoven fabric and the joint portion is 2 mm or more. <14> to < The uneven nonwoven fabric according to any one of 16>.
<18>
Said <14>-which the said 2nd nonwoven fabric contains the said fiber treatment agent, and this 2nd nonwoven fabric in the said non-joining part has a hydrophilic gradient from which hydrophilicity falls as it approaches the said joining part. The uneven nonwoven fabric according to any one of <17>.
<19>
The hydrophilicity of the second nonwoven fabric in the non-joined part gradually decreases from the distal part having a distance of 2 mm or more to the proximal part adjacent to the joined part. The uneven nonwoven fabric according to <18>.

<20>
A plurality of first protrusions having an internal space protruding to the first surface side and having the second surface side open, and a plurality of second protrusions having an internal space protruding to the second surface side and having the first surface side open And
The convex portion on the first surface is the first convex portion, the concave portion on the second surface is the second convex portion, the convex portion on the second surface is the second convex portion, and the concave portion on the second surface is the first convex portion. Yes,
The first protrusions and the second protrusions are alternately and continuously arranged along two different directions intersecting each other in plan view over the entire area of each of the first surface and the second surface. The uneven nonwoven fabric according to any one of <1> to <12>.
<21>
When the hydrophilicity is evaluated along the thickness direction of the uneven nonwoven fabric, the top portion of the first convex portion, the wall portion located between the top portion of the first convex portion and the top portion of the second convex portion, the first The uneven nonwoven fabric according to <20>, wherein the hydrophilicity increases in the order of the top of the two convex portions.
<22>
In the second convex portion as the concave portion on the first surface, the hydrophilicity of the top portion of the second convex portion, which is a portion corresponding to the bottom portion on the second surface, is higher than that of the bottom portion of the concave portion. The uneven nonwoven fabric according to <20> or <21>.
<23>
The uneven nonwoven fabric according to any one of <20> to <22>, wherein the second surface side has a higher degree of hydrophilicity than the first surface side at the top of the first convex portion.

<24>
It is configured to include a non-woven fabric having a single-layer structure containing thermoplastic fibers, and has first portions and second portions that are thinner than the first portions in one direction, and has a first surface. In addition, the first part forms a ridge as a convex part, the second part forms a groove as a concave part,
The first surface is an uneven surface formed with the ridges and the groove portions, whereas the second surface 1b is flat or has a higher degree of unevenness than the uneven surface. The uneven nonwoven fabric according to any one of <1> to <12>, which is small.
<25>
When the first part is compared with the top part Q1 of the ridge part, the bottom part Q3 on the second surface corresponding to the top part Q1, and the hydrophilicity of the intermediate part Q2 between the top part Q1 and the bottom part Q3 Furthermore, the uneven | corrugated nonwoven fabric as described in said <24> with which hydrophilicity becomes high in order of this top part Q1, this intermediate part Q2, and this bottom part Q3.
<26>
The unevenness according to <24> or <25>, wherein the portion of the second surface corresponding to the bottom of the groove portion has a higher hydrophilicity than the bottom portion of the groove portion (recessed portion) on the first surface. Non-woven fabric.
<27>
The uneven nonwoven fabric according to any one of <24> to <26>, wherein the hydrophilicity of the second part is lower than the hydrophilicity of the top part Q1 of the convex part of the first part.
<28>
<24> to <27>, wherein the hydrophilicity of the second part is lower than the hydrophilicity of the bottom part Q3 on the second surface, which is a part corresponding to the top part Q1 of the first part. Uneven nonwoven fabric.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples.

[Examples 1 to 3 (first embodiment)]
The uneven nonwoven fabric 10A of the first embodiment shown in FIGS. 1 and 2 was manufactured using the manufacturing apparatus shown in FIG. As the 1st nonwoven fabric 2 and the 2nd nonwoven fabric 3, the following were used. The first nonwoven fabric 2 and the second nonwoven fabric 3 are the same as the nonwoven fabric. In addition, for joining the first nonwoven fabric 2 and the second nonwoven fabric 3, the peripheral surface temperature of the heat roll 203 is set to 135 ° C., the temperature of the convex portion of the first roll 201 is set to room temperature, and the temperature of the second roll 202 is set to room temperature. went. For the production of the uneven nonwoven fabric 10A of Example 1, as the second nonwoven fabric 3, a material coated with a fiber treatment agent shown in Table 1 below was used at the raw fiber stage before being webbed by a card machine. As No. 2, a fiber treatment agent that does not contain the component (A) shown in Table 1 below was applied at the raw fiber stage before being made into a web by a card machine.
First non-woven fabric 2 and second non-woven fabric 3: Manufactured by using a concentric core-sheath composite fiber having a core of polyethylene terephthalate and a sheath of polyethylene as constituent fibers and fusing the constituent fibers by an air-through method. The core-sheath type composite fiber used was a non-heat-extensible fiber, and the mass ratio of the core to the sheath was core: sheath = 50: 50, the fineness was 2.2 dtex, and the fiber length was 51 mm.

[Comparative Example 1 (first embodiment)]
In the manufacture of the uneven nonwoven fabric of Comparative Example 1, the second nonwoven fabric 3 was coated with a fiber treatment agent that does not contain the component (A) shown in Table 1 below, at the stage of raw fiber before being web-made by a card machine. As the first non-woven fabric 2, a material coated with a fiber treatment agent that does not contain the component (A) shown in Table 1 below was used at the raw fiber stage before being web-formed by a card machine. Other than that was carried out similarly to Example 1, and manufactured the uneven nonwoven fabric 10A of 1st Embodiment shown in FIG.1 and FIG.2.

[Examples 4 to 8 (second embodiment)]
The uneven | corrugated nonwoven fabric 10B (air-through nonwoven fabric of a single layer structure) of 2nd Embodiment shown in FIG.6 and FIG.7 was manufactured using the manufacturing apparatus 100 shown in FIG.8 and FIG.9. The fibers of the web 105 supplied to the manufacturing apparatus 100 are shown in Table 2 below. Table 2 below also describes the composition of the fiber treatment agent applied to the fibers and the conditions in the manufacturing apparatus 100. The non-heat-extensible core-sheath composite fibers (heat-bondable fibers) shown in Table 2 below are concentric core-sheath composite fibers whose core is polyethylene terephthalate and whose sheath is polyethylene, and the mass between the core and the sheath. The ratio was core: sheath = 50: 50, the fineness was 3.3 dtex, and the fiber length was 51 mm. The heat-extensible core-sheath composite fiber shown in Table 2 below is a concentric core-sheath composite fiber in which the core is polyethylene terephthalate and the sheath is polyethylene, and the mass ratio of the core to the sheath is the core: sheath = 50:50, the fineness was 3.3 dtex, and the fiber length was 51 mm.

[Comparative Example 2 (second embodiment)]
The uneven nonwoven fabric 10B of 2nd Embodiment shown to FIG.6 and FIG.7 was manufactured like Example 2 except having used the fiber processing agent which does not contain the (A) component shown in following Table 2. FIG.

[Examples 9 and 10 (Third Embodiment)]
After producing heat-fusible fibers with a fiber treatment agent as a raw material on a fiber web using a card machine, air is sprayed onto the fiber web from a plurality of spray nozzles to move the fibers on the surface. A fiber web having was formed. As shown in FIG. 14, the fiber web was subjected to an air-through hot air treatment to produce an uneven nonwoven fabric 10 </ b> C (single-layer structure air-through nonwoven fabric) of the third embodiment shown in FIGS. 12 and 13. The raw material fibers of the web are shown in Table 3 below. Table 3 below also describes the composition of the fiber treatment agent applied to each raw fiber. The temperature of hot air in the hot air treatment was set to 136 ° C., and the wind speed was set to 0.5 m / sec. Moreover, the temperature of the compressed air injected from the circular (diameter 1 mm) injection nozzle was 20-30 degreeC normal temperature, and the air volume was 10 L / min * hole. The non-heat-extensible core-sheath type conjugate fiber (heat-fusible fiber) and the heat-extensible core-sheath type conjugate fiber shown in Table 3 are the same as those shown in Table 2 below.

[Comparative Example 3 (Third Embodiment)]
Except for using the fiber treating agent not containing the component (A) shown in Table 3 below, an uneven nonwoven fabric 10C of the third embodiment shown in FIGS. 12 and 13 was produced in the same manner as in Example 4.

Details of each component of the fiber treatment agent shown in Tables 1 to 3 below are as follows.
Component (A) Polydimethylsiloxane: Silicone “KM-903” made by Shin-Etsu Silicone. The composition of KM-903 is as follows. 18% by mass of polydimethylsiloxane having a weight average molecular weight of about 500,000, 42% by mass of polydimethylsiloxane having a weight average molecular weight of about 20,000, 5% by mass of a dispersant, and 35% by mass of water.
-Component (B) Alkyl phosphate ester: neutralized potassium hydroxide of "Gripper 4131" manufactured by Kao Corporation.
-(C) component POE (addition mole number 25) modified polyhydric alcohol fatty acid ester: POE modified hardened castor oil, "Emanon CH25" manufactured by Kao Corporation.
-POE, POP modified silicone; "X-22-4515" by Shin-Etsu Chemical Co., Ltd.
POE alkylamide; “Amizole SDE” manufactured by Kawaken Fine Chemicals Co., Ltd.
Stearyl betaine: Alkyl betaine “Amphitor 86B” manufactured by Kao Corporation.

  In Tables 1 to 3 below, the blending amount of component (A) is the blending amount of silicone alone in the composition of “KM-903”, not the blending amount of “KM-903” as a whole. . That is, the blending ratio of each component of the fiber treatment agent shown in Tables 1 to 3 below is a value calculated by excluding the dispersant and water in KM-903.

  In Tables 1 to 3 below, the amount of the fiber treatment agent attached was measured as follows using a rapid residual oil extractor. 2 g of the fiber to be measured was measured and placed in a predetermined container with a small hole in the lower part. Then, press the fiber with the lid, push the fiber into the bottom of the container, put 10cc ethanol / methanol (1: 1) mixed solution into it, let stand for 10 minutes, put the lid again, The ethanol / methanol component contained in the fiber was squeezed by pressing, and the liquid was put into a weighing dish. The solvent was blown off by heating the weighing pan, and the amount of the fiber treatment agent adhered was measured by measuring the weight after heating from the original weight of the weighing pan. N = 3 was measured, and the average was defined as the fiber treatment agent adhesion amount.

[Evaluation]
About the uneven | corrugated nonwoven fabric of an Example and a comparative example, the liquid return amount, the liquid absorption time, and the liquid residual amount were measured by the method shown below.
<Liquid return amount and liquid absorption time>
As an example of the absorbent article, the surface sheet is removed from a baby diaper (Mao's Sarasara Air-Through (registered trademark) M size) as an example of an absorbent article, and a nonwoven fabric specimen (hereinafter referred to as a nonwoven fabric specimen) is used instead. An infant diaper for evaluation obtained by fixing its periphery was used. The diaper was spread in a flat shape, an acrylic plate with a cylindrical injection part was placed on the top sheet, a weight was placed on the acrylic plate, and a load of 2 kPa was applied to the absorber part. The injection part provided in the acrylic plate has a cylindrical shape (height 53 mm) with an inner diameter of 36 mm. The acrylic plate has a cylindrical part of the cylindrical injection part at a third portion in the longitudinal direction and the central axis in the width direction. A through hole having an inner diameter of 36 mm is formed so that the central axes coincide with each other and communicates between the inside of the cylindrical injection portion and the surface sheet facing surface of the acrylic plate. The core wrap sheet covering the diaper absorbent core is placed so that the central axis of the cylindrical injection portion of the acrylic plate comes to a position of 155 mm from the tip of the longitudinal side of the core wrap sheet, and 40 g of artificial urine is injected. Absorbed and allowed to stand for 10 minutes, and further injected 40 g of artificial urine for absorption. Such artificial urine injection operation was repeated four times, and a total of 160 g of artificial urine was absorbed in the diaper. After standing for 10 minutes from the completion of injection, the cylinder and pressure were removed. Next, filter paper No. manufactured by Advantech Co., Ltd., centering on the injection point of artificial urine in the diaper. A load was applied so that 16 sheets of 5C (100 mm × 100 mm, mass measurement W1) were applied, and a pressure of 3.5 kPa was further applied thereon. After the elapse of 2 minutes, the load was removed, the mass (W2) of the filter paper that absorbed artificial urine was measured, and the liquid return amount was calculated according to the following equation.
Liquid return amount (g) = mass of filter paper after pressurization (W2) −mass of first filter paper (W1)

Further, in the measurement of the liquid return amount, the injection time of artificial urine at each injection time (the time from the start of injection until the entire amount was absorbed by the diaper) was defined as the liquid absorption time.
The smaller the liquid return amount, the higher the evaluation that the liquid return is less likely to occur, and the shorter the liquid absorption time, the better the excretion fluid permeability and the higher the evaluation.
The composition of the artificial urine is as follows: 1.94% by mass of urea, 0.7954% by mass of sodium chloride, 0.11058% by mass of magnesium sulfate (septahydrate), 0.06208 of calcium chloride (dihydrate) % By mass, potassium sulfate 0.19788% by mass, polyoxyethylene lauryl ether 0.0035% by mass and ion-exchanged water (remaining amount).

[Liquid remaining amount]
As an example of the absorbent article, the surface sheet is removed from a baby diaper (Mao's Sarasara Air-Through (registered trademark) M size) as an example of an absorbent article, and a nonwoven fabric specimen (hereinafter referred to as a nonwoven fabric specimen) is used instead. An infant diaper for evaluation obtained by fixing its periphery was used. 40g of artificial urine is infused at a rate of 5g / sec using an infusion pump at a position of 155mm from the tip of the ventral portion in the longitudinal direction of the core wrap sheet covering the absorbent core of the diaper. Then, it was allowed to stand for 10 minutes, and then 40 g of artificial urine was injected and absorbed. Such artificial urine injection operation was repeated four times, and a total of 160 g of artificial urine was absorbed in the diaper. After standing for 10 minutes from the completion of the injection, the 10 cm × 10 cm surface sheet is peeled off around the injection point, and the weight (W4) is measured. Thereafter, the top sheet was dried at 105 ° C. for 1 hour using a dryer, the weight (W3) was measured, and the remaining liquid amount was calculated as in the following equation.
Liquid remaining amount (g) = 160 g of surface material after injection (W4) −mass of dried surface material (W3)

  From the comparison of the results of each Example and Comparative Example in Table 1, Table 2 and Table 3, the absorbent article using the uneven nonwoven fabric of the present invention as a surface sheet has excellent liquid permeability and liquid return. It can be seen that the difficulty has also improved.

10A uneven nonwoven fabric (first embodiment)
1a 1st surface 1b 2nd surface 2 1st nonwoven fabric 3 2nd nonwoven fabric 4 Joining part (concave part in 1st surface)
5 Convex part 6 Non-joint part 10B Convex / unwoven fabric (second embodiment)
11 1st convex part 12 2nd convex part 11 1st convex part 11T 1st convex part top part 11K Internal space 11H Opening part 12 2nd convex part 12T 2nd convex part top part 12K Internal space 12H Opening part 13 and 14 Wall part 10C , 10C1 Uneven uneven nonwoven fabric (third embodiment)
21 1st part 22 2nd part 23 Projection part (convex part)
24 Groove (recess)

Claims (7)

It is comprised including a thermoplastic fiber, has a 1st surface and the 2nd surface located on the opposite side, and at least 1st surface is between the several convex part which protrudes in the 1st surface side, and this convex part. It is an uneven nonwoven fabric having unevenness consisting of a recessed portion located,
The fiber treatment agent is attached,
The uneven | corrugated nonwoven fabric in which the said fiber treatment agent contains the following (A) component, (B) component, and (C) component.
(A) Polyorganosiloxane (B) Phosphate ester type anionic surfactant (C) Polyoxyalkylene-modified polyhydric alcohol fatty acid ester   The concavo-convex nonwoven fabric according to claim 1, wherein any part of the second surface has higher hydrophilicity than the top of the convex portion on the first surface.   The uneven nonwoven fabric according to claim 1 or 2, wherein a portion of the second surface corresponding to the bottom portion has a higher hydrophilicity than the bottom portion of the concave portion on the first surface.   The uneven nonwoven fabric according to any one of claims 1 to 3, wherein at least a part of the thermoplastic fiber is a heat-extensible fiber.   The uneven nonwoven fabric according to any one of claims 1 to 4, wherein the polyorganosiloxane is contained in a proportion of 1% by mass to 30% by mass with respect to the total mass of the fiber treatment agent.   The uneven nonwoven fabric according to any one of claims 1 to 5, wherein the polyoxyalkylene-modified polyhydric alcohol fatty acid ester is contained in a proportion of 20% by mass or less based on the total mass of the fiber treatment agent.   In the absorbent article provided with the absorber and the surface sheet distribute | arranged to the skin opposing surface side of this absorber, The uneven | corrugated nonwoven fabric of any one of Claims 1-6 is used as this surface sheet, and this The absorbent article arrange | positioned so that the 1st surface of an uneven | corrugated nonwoven fabric may face a wearer's skin.

Images