WO2019151527A1 - Non-woven fabric and method for manufacturing non-woven fabric - Google Patents

Abstract

Provided is a non-woven fabric that includes cellulose fibers and adhesive fibers, wherein: the non-woven fabric includes adhesion locations where the adhesive fibers are adhered to the cellulose fibers and/or the adhesive fibers, and interlace locations where the cellulose fibers are interlaced with the cellulose fibers and/or the adhesive fibers; an adhesion intersection point index A of the non-woven fabric is 1-60 per mm2, or a thickness reduction rate of the non-woven fabric is 30-45%.

Description

Nonwoven fabric and method for producing nonwoven fabric

The present invention relates to a nonwoven fabric and a method for producing the nonwoven fabric.

Nonwoven fabrics are used in absorbent articles such as disposable diapers, sanitary napkins, incontinence pads, and panty liners. Cellulosic fibers are excellent in hygroscopicity and are renewable fibers derived from plants. Therefore, nonwoven fabrics containing cellulosic fibers are of interest from the viewpoint of reducing the burden on the natural environment.
Non-woven fabrics containing cellulosic fibers have insufficient suppression of fluff, and for example, non-woven fabrics that have undergone hydroentanglement and non-woven fabrics in which constituent fibers are bonded together by thermal fusion of heat-fusible fibers are used. Yes.
However, there is a problem that the former has a hard texture and the latter still has insufficient fuzz suppression.
Therefore, non-woven fabrics containing cellulosic fibers are not intended for direct contact with human skin, but are not important for fluff suppression and softness of texture, do not directly touch human skin, and absorbent articles such as absorbent articles. It is used (see Patent Document 1).

JP 2002-159533 A

The present invention provides a non-woven fabric containing cellulosic fibers and a method for producing the non-woven fabric that can be used for direct contact with human skin, such as an absorbent article, which achieves both softness of the non-woven fabric and suppression of fluff. It was made for the purpose.

The inventors of the present invention have a non-woven fabric containing both cellulosic fibers and adhesive fibers, including a location where the fibers are bonded to each other by the adhesive fiber and a location where the fibers are entangled, and further adjusting specific physical properties of the non-woven fabric. Thus, it has been found that at least one of the suppression of fluff and the softness of the texture can be improved, and preferably both can be improved, and the present invention has been completed.
Furthermore, when manufacturing the nonwoven fabric containing both a cellulosic fiber and an adhesive fiber, the present inventors previously bonded the fibers together and then entangled the fibers to suppress the softness of the texture and the fluff. As a result, it was found that a non-woven fabric having both of the above can be obtained, and the present invention has been completed.

That is, the present invention in one aspect,
A nonwoven fabric comprising cellulosic fibers and adhesive fibers,
Including an adhesion point between the adhesive fiber and the cellulosic fiber and / or the adhesive fiber,
Including an entangled portion of the cellulosic fiber and cellulosic fiber and / or adhesive fiber,
A nonwoven fabric is provided in which the nonwoven fabric has an adhesion intersection index A of 1 to 60 pieces / mm ² or a thickness reduction rate of the nonwoven fabric of 30 to 45%.
The nonwoven fabric of the form of this invention can be used for the use which touches human skin directly, such as an absorbent article, for example.

In another aspect, the present invention provides:
A method for producing a nonwoven fabric comprising cellulosic fibers and adhesive fibers, comprising: an adhesion step of bonding fibers together with the adhesive fibers; and an entanglement step of interlacing fibers after the adhesion step A manufacturing method is provided.

Since the nonwoven fabric of the present disclosure has the above-described characteristics, it has both the suppression of fuzz and the softness of the texture, and can be used for applications that directly touch human skin such as absorbent articles.

FIG. 1 shows an SEM image of a cut surface obtained by cutting the nonwoven fabric of Example 31 in the longitudinal direction. The magnification is 60 times. FIG. 2 shows an SEM image of a cut surface obtained by cutting the nonwoven fabric of Comparative Example 50 in the lateral direction. The magnification is 25 times. FIG. 3 shows an SEM image of a cut surface obtained by cutting the nonwoven fabric of Example 31 in the lateral direction. The magnification is 100 times. FIG. 4 shows an SEM image of the surface of the nonwoven fabric of Example 31. The magnification is 100 times. FIG. 5 shows the SEM image of the back surface of the nonwoven fabric of Example 31. The magnification is 100 times.

The nonwoven fabric in the form of the present invention is
A nonwoven fabric comprising cellulosic fibers and adhesive fibers,
Including an adhesion point between the adhesive fiber and the cellulosic fiber and / or the adhesive fiber,
Including an entangled portion of the cellulosic fiber and cellulosic fiber and / or adhesive fiber,
(I) The bonding intersection index A of the nonwoven fabric is 1 to 60 pieces / mm ² , or (ii) the thickness reduction rate of the nonwoven fabric is 30 to 45%.
It is a nonwoven fabric.
Nonwoven fabric in the form of the present invention is used for skin contact products that directly touch human skin such as absorbent articles (for example, liquid-impregnated skin impregnated with liquids such as top sheets and back sheets for absorbent articles, cosmetics, etc.) Cover materials (for example, face masks, keratin care sheets, decollete sheets, etc.), base materials for various poultry materials, including hot and cold compresses, and personal wipes (for example, cleansing sheets, antiperspirant sheets, and removers) Bacteria sheet etc.)).

(Cellulose fiber)
In the nonwoven fabric in the form of the present invention, “cellulosic fibers” are also called fiber fibers and generally refer to fibers made from cellulose.
Cellulosic fibers are, for example, natural fibers derived from plants such as cotton, hemp, flax (linen), ramie, jute, banana, bamboo, kenaf, moon peach, hemp and kapok; Recycled fibers such as rayon and polynosic rayon, cupra obtained by copper ammonia method, Tencel (registered trademark) and lyocell (registered trademark) obtained by solvent spinning method; cellulose fiber obtained by melt spinning method; and acetate fiber, etc. There is no particular limitation as long as the nonwoven fabric intended by the present invention can be obtained including semi-synthetic fibers.

The fineness of the cellulosic fibers is preferably from 0.6 to 5.6 dtex, more preferably from 1.0 to 4.4 dtex, and even more preferably from 1.4 to 3.3 dtex.
When the fineness of the cellulosic fiber is within the above-mentioned range, the strength of the nonwoven fabric is more suitable because the fineness is not too small, and the texture of the nonwoven fabric is more suitable because the fineness is not too large. . Further, when the fineness of the cellulosic fiber is within the above-mentioned range, the entanglement of the fiber becomes more suitable, and the nonwoven fabric is not too entangled so that the strength and fluff of the nonwoven fabric are more suitable. It is preferable because the texture of the nonwoven fabric becomes more suitable because the properties are not too high.

The fiber diameter of the cellulosic fiber is preferably 5 to 25 μm, more preferably 8 to 20 μm, and even more preferably 10 to 17 μm.
When the fiber diameter of the cellulosic fiber is within the above range, the strength of the nonwoven fabric is more suitable because the fineness is not too small, and the texture of the nonwoven fabric is more suitable because the fineness is not too large. preferable. Further, when the fineness of the cellulosic fiber is within the above-mentioned range, the entanglement of the fiber becomes more suitable, and the nonwoven fabric is not too entangled so that the strength and fluff of the nonwoven fabric are more suitable. It is preferable because the texture of the nonwoven fabric becomes more suitable because the properties are not too high.

The fiber length of the cellulosic fiber is preferably 25 to 100 mm, more preferably 30 to 70 mm, and still more preferably 35 to 60 mm.
When the fiber length of the cellulosic fiber is within the above-described range, the fiber entanglement is suitable, which is preferable. In particular, since the nonwoven fabric of the present disclosure can be manufactured by performing the entanglement process after the constituent fibers are once bonded to each other by the adhesive fiber, the bonding position in one fiber is more appropriate because the fiber length is not too large. This is preferable because the fibers can be entangled more suitably to such an extent that the fluff can be sufficiently suppressed. In addition, since the fiber length is not too small, the number of bonded portions in one fiber becomes a more appropriate number, and the fibers can be entangled more suitably so that the texture of the nonwoven fabric can be sufficiently softened.

The cross section of the cellulosic fiber (cross section or cross section perpendicular to the length direction of the fiber) may be circular or non-circular. , X shape, well shape, multileaf shape, polygonal shape, star shape, chrysanthemum shape and the like. When the cross section of the fiber is circular, since the area to be bonded to the adhesive fiber is relatively small, the softness of the texture of the nonwoven fabric can be improved. When the cross section of the fiber is non-circular, since the area that adheres to the adhesive fiber is relatively large, the suppression of fuzz of the nonwoven fabric can be better, or the strength of the nonwoven fabric can be higher.

Cellulosic fibers are preferably chemical fibers such as recycled fibers and semi-synthetic fibers. Chemical fibers are more preferable because they can further reduce variations in fineness and / or fiber diameter and fiber length, and can easily adjust the degree of entanglement of the nonwoven fabric. In addition, rayon, solvent-spun cellulose fiber, and the like have a good balance of softness and strength when wet which the fiber itself has, and it is easier and more preferable to obtain softness and strength suitable for a nonwoven fabric. Solvent-spun cellulose fibers are preferable in that they have a relatively high single fiber strength, and are therefore more advantageous in suppressing the fluff of the nonwoven fabric and improving the strength of the nonwoven fabric.
Cellulosic fibers can be used alone or in combination.

Cellulosic fibers may be subjected to a surface treatment to change the degree of hydrophilicity or hydrophobicity of the surface. In general, an oil agent (surfactant) can be used to change the degree of hydrophilicity or hydrophobicity of the surface of the cellulosic fiber. The degree of hydrophilicity or hydrophobicity can be evaluated, for example, using a value such as a fiber sedimentation rate. The surface of the cellulosic fiber may be hydrophilic or hydrophobic. The value of the settling speed (or settling time (sec)) of the fiber may be, for example, 30 seconds or less, more preferably 20 seconds or less, and further preferably 10 seconds or less. When the settling speed (or settling time) of the cellulosic fibers is small, the entanglement of the cellulosic fibers can be relatively good, the fuzziness of the nonwoven fabric can be better controlled, or the strength of the nonwoven fabric can be increased.

The sedimentation rate of the fiber can be measured by the following method.
17 g of the fiber whose sedimentation rate is to be measured is collected. The collected fibers are opened (using a parallel card machine) to form a card web. 5 g of the card web is weighed and filled into a copper wire (thickness 0.55 mm) bag (5 g in diameter and 3 g in a cylindrical bag body having a height of 8 cm).
Next, a thermostatic water tank is prepared, tap water is put in the thermostatic water tank, and it sets so that it may become 25 degreeC. When the water temperature reaches 25 ° C., the stirring of the constant temperature bath is stopped and the measurement of the sedimentation rate is started. Gently drop the bag filled with fibers according to the above procedure from a position 1 cm above the water surface, and start the stopwatch as soon as the bag falls to the water surface. The stopwatch is stopped at the same time as the fibers are gradually hydrated and the ridges of 8 cm in height are completely submerged. The time from when the cocoon falls to the water surface until the cocoon sinks below the water surface is defined as the sedimentation speed, and the average value measured twice is defined as the sedimentation speed of the fiber.

In the measurement of the settling rate, if the soot does not sink below the water surface for 5 minutes or more, the fiber is assumed to be water repellent. When the cellulosic fiber is water-repellent, it may be preferable in applications where the nonwoven fabric is brought into contact with a liquid. For example, in a top sheet and a second sheet for absorbent articles, it may be preferable that the cellulosic fiber is water-repellent because the liquid is easily moved to the absorbent body without holding the liquid too much in the sheet. In addition, when the nonwoven fabric has a laminated structure, when a laminated nonwoven fabric having a layer containing cellulosic fibers that are water repellent and a layer containing cellulosic fibers that are not water repellent is used, liquids such as sheets for absorbent articles and cosmetics are used. In the use of a liquid-impregnated skin dressing impregnated with a non-woven fabric, the nonwoven can suitably move or retain the liquid.

(Adhesive fiber)
In the nonwoven fabric in the form of the present invention, “adhesive fiber” indicates adhesion by adhesion treatment (for example, thermal adhesion treatment, electron beam irradiation, ultrasonic welding (ultrasonic welder), etc.), and bonds the fibers together. Thus, the fiber that can form the bonded portion is referred to, and is not particularly limited as long as a nonwoven fabric intended by the present disclosure can be obtained.

The adhesive fiber includes, for example, a synthetic fiber made of a thermoplastic resin.
The thermoplastic resin is not particularly limited as long as the nonwoven fabric intended by the present invention can be obtained. For example, polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, polylactic acid, polybutylene succinate and its co-polymer Polyester resins such as coalescents; polypropylene, polyethylene (including high-density polyethylene, low-density polyethylene, linear low-density polyethylene, etc.), polybutene-1, and propylene copolymer (propylene-ethylene copolymer) containing propylene as the main component Polyolefin resins such as Nylon 6, Nylon 12 and Nylon 66; Polyolefin resins such as copolymers, propylene-butene-1-ethylene copolymers), ethylene-acrylic acid copolymers, and ethylene-vinyl acetate copolymers; Tree Fats; acrylic resins; engineering plastics such as polycarbonate, polyacetal, polystyrene, and cyclic polyolefin, and elastomers thereof can be exemplified and can be arbitrarily selected from these.

The adhesive component of the adhesive fiber is preferably a copolymer of an olefin and an unsaturated carboxylic acid or a derivative thereof from the viewpoint of improving the adhesiveness with the cellulosic fiber. Examples of the unsaturated carboxylic acid include maleic acid, acrylic acid, methacrylic acid, fumaric acid, itaconic acid, and derivatives thereof include unsaturated carboxylic acid anhydrides, methyl methacrylate, ethyl methacrylate, 2-methacrylic acid 2- Methacrylic acid esters such as hydroxyethyl and dimethylaminoethyl methacrylate, or similar acrylic acid esters, glycidyl acrylate, glycidyl methacrylate, butenecarboxylic acid esters, allyl glycidyl ether, 3,4-epoxybutene, 5,6- Examples include epoxy-1-hexene and vinylcyclohexene monoxide. In particular, an ethylene-acrylic acid copolymer in which the olefin is ethylene and the unsaturated carboxylic acid or derivative thereof is acrylic acid is preferable.

The synthetic fiber may be a single fiber composed of one or a plurality of thermoplastic resins selected from the above, or may be a composite fiber composed of two or more components (also referred to as “sections”). In the composite fiber, each component may be composed of one thermoplastic resin, or may be a mixture of two or more thermoplastic resins. The composite fiber may be, for example, a core-sheath composite fiber, a sea-island composite fiber, or a side-by-side composite fiber. The core-sheath type composite fiber may be an eccentric core-sheath type composite fiber in which the center of the core component does not coincide with the center of the sheath component in the fiber cross section, and the center of the core component coincides with the center of the sheath component in the fiber cross section. It may be a sheath type composite fiber.

Whether it is a single fiber or a composite fiber, the synthetic fiber may have an atypical cross section. In the case of the core-sheath type composite fiber and the sea-island type composite fiber, the core component and / or the island component may have an atypical cross section in the fiber cross section.
When the synthetic fiber has an atypical cross section, the cross section may be an ellipse, a polygon, a star, or a shape in which a plurality of convex portions are joined at the base (for example, a clover shape).
In the present embodiment, two or more synthetic fibers may be used in combination as synthetic fibers.

When the synthetic fiber is a composite fiber, two or more components may be arranged so that a thermoplastic resin having a lower melting point forms part of the fiber surface. The low melting point thermoplastic resin (low melting point component) melts or softens when heat is applied in the process of producing the nonwoven fabric to become an adhesive component. The low melting point component contributes to adhesion between fibers or adhesion to other members, and can form an adhesion site.
When the synthetic fiber is a composite fiber, the low melting point component is preferably exposed at a length of 50% or more with respect to the length of the peripheral surface of the fiber in the fiber cross section, and a length of 60% or more. It is more preferable that it is exposed at a length of 80% or more, and it is particularly preferable that the entire surface of the fiber is exposed.

The non-woven fabric in the form of the present invention can be produced by previously bonding fibers together and then interlacing the fibers. Therefore, there are more moderate areas where the low melting point component of the adhesive fiber is exposed on the fiber peripheral surface in the fiber cross section, and the number of adhesion points between the fibers is more moderate. Thus, the bonding strength at the bonding position between the fibers becomes more appropriate, and the adhesion by the adhesive fibers can be made more sufficient. Therefore, the suppression of the fluff of the nonwoven fabric and the strength of the nonwoven fabric can be made more suitable. Further, in the subsequent entanglement, the degree to which the adhesion between the fibers is eliminated becomes more appropriate, and it is possible to further suppress the fluff of the nonwoven fabric and to make the nonwoven fabric more sufficiently strong. In particular, the nonwoven fabric of the present embodiment contains cellulosic fibers, the adhesion between the cellulosic fibers and the adhesive fibers is not high, and the elimination of the adhesion between the fibers is further promoted. The impact can be greater.

The combination of the thermoplastic resin constituting the composite fiber is, for example, a combination of a polyolefin resin such as polyethylene / polyethylene terephthalate, polypropylene / polyethylene terephthalate, and propylene copolymer / polyethylene terephthalate and a polyester resin (polyolefin resin / polyester). Resin), and a combination of two types of polyolefin resins (polyolefin resin / polyolefin resin) such as polyethylene / polypropylene, propylene copolymer / polypropylene, ethylene-acrylic acid copolymer / polypropylene, and two different melting points. Includes combinations of polyester resins (polyester resin / polyester resin).

Note that the thermoplastic resin exemplified as a constituent component of a single fiber or a composite fiber may contain other components as long as it contains 50 mass% or more of the specifically shown thermoplastic resin. For example, in the combination of polyethylene / polyethylene terephthalate, “polyethylene” may contain other thermoplastic resins and additives as long as it contains 50% by mass or more of polyethylene. This also applies in the following examples.

When the adhesive fiber is a core-sheath type composite fiber in which a thermoplastic resin having a lower melting point constitutes the sheath, the core / sheath combination includes, for example, polyethylene terephthalate / polyethylene, polyethylene terephthalate / polypropylene, and polyethylene terephthalate / propylene. Copolymers, polytrimethylene terephthalate / polyethylene, polybutylene terephthalate / polyethylene, polyethylene terephthalate / copolyester (eg, polyethylene terephthalate copolymerized with isophthalic acid), and polypropylene / ethylene-acrylic acid copolymer. The core-sheath type composite fiber whose sheath is polyethylene (for example, high density polyethylene, low density polyethylene, or linear low density polyethylene) or copolymer polyester is heat-treated at a temperature equal to or higher than the melting point of the thermoplastic resin constituting the sheath. By doing so, the sheath melts or softens, and the fibers are bonded to each other to form a bonded portion.

When the adhesive fiber is a core-sheath type composite fiber, the core-sheath composite ratio (volume ratio, core / sheath) may be, for example, 80/20 to 20/80, particularly 60/40 to 40/60. It may be.
When the ratio of the sheath is not too small, the adhesion between the fibers becomes more sufficient, the suppression of the fluff becomes more suitable, or the strength of the nonwoven fabric can be more suitable. Moreover, the peeling of the adhesion site | part at the time of an entanglement becomes more moderate, Furthermore, suppression of a fluff becomes more suitable, or the strength of a nonwoven fabric may become more suitable. By not having too much ratio of a sheath, the ratio of the core component which maintains a fiber shape becomes more sufficient, and the strength of the nonwoven fabric can be more suitable.

The adhesive fiber includes two or more fibers, and the melting points of the adhesive components of these fibers may be different from each other. For example, the adhesive fiber includes two fibers, and the difference in melting point between the adhesive components of these fibers may be 10 ° C. or more and 40 ° C. or less, and may be 15 ° C. or more and 30 ° C. or less.

The fineness of the adhesive fiber is preferably 1.0 to 7.8 dtex, more preferably 1.4 to 6.7 dtex, and even more preferably 2.2 to 4.5 dtex.
When the fineness of the adhesive fiber is within the above-described range, it is preferable because the strength of the nonwoven fabric is further improved and the texture of the nonwoven fabric becomes softer.

The fiber diameter of the adhesive fiber is preferably 10 to 33 μm, more preferably 12 to 30 μm, and even more preferably 15 to 25 μm.
When the fiber diameter of the adhesive fiber is within the above-mentioned range, the strength of the nonwoven fabric is further improved, and the texture of the nonwoven fabric is softened.

The fiber length of the adhesive fiber is preferably 25 to 100 mm, more preferably 30 to 70 mm, and still more preferably 35 to 60 mm.
It is preferable that the fiber length of the adhesive fiber is in the above-mentioned range since the confounding property of the fiber becomes more suitable. In particular, the nonwoven fabric according to the present disclosure can be manufactured by once linking constituent fibers with adhesive fibers and then performing an entanglement treatment. Therefore, since the fiber length is not too large, the number of bonded portions in one fiber becomes a more appropriate number, and the confounding property of the fiber can be made more suitable to the extent that fuzz can be more sufficiently suppressed. Further, since the fiber length is not too small, the number of bonded portions in one fiber becomes a more appropriate number, and the entanglement of the fiber can be made more suitable to the extent that the texture of the nonwoven fabric can be made sufficiently soft.

The adhesive fiber preferably has steric crimps. In this specification, the term “steric crimp” is used to distinguish it from a mechanical crimp in which the peak (or peak) of the crimp is an acute angle. The three-dimensional crimp includes, for example, a crimp in which a peak is curved (wave shape crimp), a crimp in which a peak is curved in a spiral (spiral crimp), and a combination of a wave crimp and a spiral crimp. A crimp in which an acute angle crimp of mechanical crimping and at least one of a wave crimp and a spiral crimp are mixed. The adhesive fiber may have a mechanical crimp.
When the adhesive fiber is a composite fiber, it may be an actual crimpable composite fiber. “Actual crimpable composite fiber” refers to a fiber that exhibits steric crimps at the fiber stage. The actual crimpable conjugate fiber is different from the latent crimpable conjugate fiber that expresses steric crimps by heat treatment accompanied by fiber shrinkage.

When the adhesive fiber is an eccentric core-sheath type composite fiber, the eccentricity is preferably 5 to 50%, more preferably 7 to 30%. The eccentricity here is defined by the following equation.
(Expression) Eccentricity (%) = (Distance between center of single fiber and center of core component) × 100 / (radius of single fiber)
When the adhesive fiber has three-dimensional crimps, the non-woven fabric adhesion intersection index A, the non-woven fabric thickness reduction rate, the bending resistance per unit thickness of the non-woven fabric, the non-woven fabric thickness ratio, and the non-woven fabric thickness direction As for the angle of the fiber bonding point in the middle when the resin is divided into three, the nonwoven fabric showing a value within a specific range can be obtained more easily and is more preferable.
Adhesive fibers can be used alone or in combination.

In the nonwoven fabric of the present invention, the mixing ratio of the cellulosic fibers and adhesive fibers (cellulosic fibers: adhesive fibers) (mass ratio) is preferably 10:90 to 90:10, and 25:75 to More preferably, it is 75:25, and even more preferably 35:65 to 65:35.
When the mixing ratio of the cellulosic fiber and the adhesive fiber (cellulosic fiber: adhesive fiber) (mass ratio) is within the above range, both the softness of the nonwoven fabric and the suppression of the fluff can be further improved. preferable.
Moreover, when a cellulosic fiber is contained moderately, the effect by a cellulosic fiber can be acquired more easily.
Further, when cellulosic fibers are appropriately contained, the fibers can be entangled more easily, and the non-woven fabric adhesion intersection index A, the non-woven fabric thickness reduction rate, and the softness per unit thickness of the non-woven fabric will be described later. The nonwoven fabric showing a specific range of values for the degree, the thickness ratio of the nonwoven fabric, and the angle of the fiber bonding point in the middle when it is equally divided into three in the thickness direction of the nonwoven fabric can be obtained more preferably.
In addition, it is preferable that the adhesive fibers are appropriately contained because both the suppression of the fluff of the nonwoven fabric and the softness of the texture of the nonwoven fabric are improved.
When the non-woven fabric in the form of the present invention has an adhesive fiber of 35% by mass or more, the non-woven fabric or intermediate fiber web is broken or unnecessarily stretched during conveyance in producing the non-woven fabric. Since it becomes easy to prevent, it is preferable.

The nonwoven fabric of this embodiment may contain fibers other than cellulosic fibers and adhesive fibers (hereinafter “other fibers”). Other fibers include, for example, natural fibers that are not cellulosic fibers (for example, wool, silk, etc.), synthetic fibers that are not adhesive fibers (for example, those that do not melt or soften when the adhesive component of the adhesive fibers is melted, and are adhesive Is not particularly limited as long as the nonwoven fabric intended by the present invention can be obtained.
Other fibers may be included in a proportion of 35% by mass or less, in particular 25% by mass or less, more particularly in a proportion of 10% by mass or less, as long as the nonwoven fabric intended by the present invention can be obtained. There is no particular limitation. The nonwoven fabric of this embodiment may be a nonwoven fabric not containing other fibers, that is, a nonwoven fabric composed of cellulosic fibers and adhesive fibers.

In the nonwoven fabric of the present embodiment, the fibers are bonded with adhesive fibers. That is, the nonwoven fabric in the form of the present invention includes an adhesion portion. Thereby, both the strength of the nonwoven fabric and the suppression of fluff are ensured, and the handleability is improved. Adhesion with adhesive fibers can be achieved by fixing a fiber in which a portion of the adhesive fiber is melted or softened or altered to exhibit adhesion and intersect or contact it. Specifically, the adhesion between fibers refers to the adhesion between an adhesive fiber and an adhesive fiber, the adhesion between an adhesive fiber and a cellulosic fiber, and when other fibers are further included, This refers to adhesion between adhesive fibers and other fibers. The adhesion may be by thermal adhesion in which heat is applied to melt or soften part of the adhesive fiber, or may be by irradiation with an electron beam or ultrasonic welding.

In the nonwoven fabric of this embodiment, the fibers are entangled. That is, the nonwoven fabric in the form of the present invention includes an entangled portion. Thereby, both the strength of the nonwoven fabric and the suppression of fluff are ensured, and the handleability is improved. Interlacing of fibers can be achieved by entanglement of fibers, for example, by attaching a nonwoven fabric to a material flow. Specifically, entanglement between fibers refers to entanglement between adhesive fibers and adhesive fibers, entanglement between adhesive fibers and cellulosic fibers, and entanglement between cellulosic fibers and cellulosic fibers. Is further included, the entanglement between the adhesive fiber and the other fiber, the entanglement between the cellulosic fiber and the other fiber, and the entanglement between the other fiber and the other fiber. The entanglement may be a needle punch method or a fluid flow, and the fluid flow may be a water flow, an air flow, a water vapor flow, or the like. In the nonwoven fabric of this embodiment, in order to entangle a cellulosic fiber, the thing by a water flow or a water vapor flow is preferable.

The nonwoven fabric of this embodiment preferably has a basis weight of 10 to 150 g / m ² , more preferably has a basis weight of 15 to 80 g / m ² , and still more preferably has a basis weight of 20 to 60 g / m ^2. A basis weight of 25 to 50 g / m ² is particularly preferred. It is preferable that the basis weight is not too small because both the softness of the nonwoven fabric and the suppression of fluff are further improved. In addition, since the basis weight is not too small, the entanglement proceeds more appropriately throughout the nonwoven fabric, and the nonwoven fabric adhesion intersection index A, the nonwoven fabric thickness reduction rate, the bending resistance per unit thickness of the nonwoven fabric, and the nonwoven fabric thickness A nonwoven fabric having a specific range of values can be obtained more easily with respect to the thickness ratio, the angle of the fiber bonding point in the middle when the nonwoven fabric is divided into three equal parts in the thickness direction, and the like. Since the basis weight is not too large, the strength of the nonwoven fabric and the suppression of fluff can be further improved.

The nonwoven fabric of this embodiment as a whole may have a fiber density of, for example, 0.0100 to 0.100 g / cm ³ when dried, and a fiber density of 0.0125 to 0.0600 g / cm ^3. And a fiber density of 0.0180 to 0.0400 g / cm ³ is more preferable. The fiber density of the entire nonwoven fabric can be obtained from the basis weight and thickness (thickness measured by applying a load of 40 Pa).

In the nonwoven fabric of this embodiment, it is preferable that the fiber density of at least one surface (that is, the front surface or the back surface) is higher than the internal fiber density when a cross section cut along the thickness direction is observed. In this embodiment, it is more preferable that the fiber density is higher than the internal fiber density on both the front surface and the back surface. When the fiber density of at least one surface is higher than the internal fiber density, both the softness of the nonwoven fabric and the suppression of fluff can be further improved. Whether or not there is a difference between the fiber density inside the nonwoven fabric and the fiber density on the surface can be examined by observing a cross section of the nonwoven fabric along the thickness direction with an electron microscope (approximately 50 times magnification). . More specifically, when observed with an electron microscope, the portion where the fibers are gathered more densely is a region where the fiber density is higher, and the portion where the fibers are gathered more loosely is lower in the fiber density. It can be said that it is an area.

The height of the fiber density can be confirmed, for example, by counting the number of cross-sections of fibers cut per fixed area with an electron microscope (about 50 times magnification) in a cross-section cut along the thickness direction of the nonwoven fabric. More specifically, when the cross section of the nonwoven fabric is divided into five equal parts along the thickness direction, the upper and lower fifth portions are designated as “nonwoven fabric surface” (“upper surface” (upper surface) and “upper surface”, respectively). Lower surface ”(lower surface)), and three-fifths excluding the upper fifth part and the lower fifth part when the cross section of the nonwoven fabric is divided into five equal parts along the thickness direction. When the ratio of the number of cross sections of the fibers on the surface of the nonwoven fabric to the number of cross sections of the fibers inside the nonwoven fabric is 1.05 or more when the portion is “inside of the nonwoven fabric”, the fiber density on the nonwoven fabric surface is higher than the inside. Can be considered.

In the non-woven fabric of this embodiment, it is preferable that an adhesive peeling mark in which a bonding portion due to the adhesive fiber is eliminated is formed on the adhesive fiber. The adhesive delamination marks can be formed mainly by the confounding process after the adhesive process. In the adhesion peeling trace, an adhesive component (for example, a sheath component in the case of a core-sheath type composite fiber) is present thinner than the fiber surface of a normal adhesive fiber. Since the fibers can be easily bent by the adhesive peeling trace and the softness of the nonwoven fabric can be improved, it is preferable that the adhesive peeling trace is appropriately included. Adhesion peeling trace can be confirmed by observing the surface and cross section of a nonwoven fabric using an electron microscope.

The non-woven fabric of the present embodiment may be laminated with another non-woven fabric on one surface of the non-woven fabric, but it is preferable that at least one surface is exposed. More preferably, both surfaces of the nonwoven fabric are exposed. In addition, although the nonwoven fabric of this embodiment may be a single layer structure, it is good also as a laminated structure, for example, what changed the mixture rate of the cellulosic fiber and adhesive fiber in each layer. It is preferable that the nonwoven fabric of this embodiment has a single-layer structure because it can have both suppression of fuzz and softness of the texture on both sides of the nonwoven fabric. In addition, it is preferable that the nonwoven fabric has a single-layer structure because delamination and nonwoven fabric strength reduction due to weak entanglement can be suppressed, and reduction in softness of texture due to strong entanglement can be suppressed. Since the nonwoven fabric of this embodiment is good in both the softness of the nonwoven fabric and the suppression of fluff, it is used for exposing the nonwoven fabric of this embodiment, for example, top sheets and back sheets for absorbent articles, Liquid-impregnated skin covering materials impregnated with liquids such as cosmetics (for example, face masks, keratin care sheets, decollete sheets, etc.), base materials for various poultry materials including hot and cold compresses, and wipes for people (For example, a cleansing sheet, an antiperspirant sheet, a disinfectant sheet, etc.), can be suitably used for disposable clothing and the like.

When the nonwoven fabric of this embodiment has a laminated structure, it is preferable because each layer can have different performance from each other. For example, the texture of the nonwoven fabric can be improved in one layer, and the suppression of fuzz can be improved in the other layer. The degree of hydrophilicity can be changed for each layer. Adhesive fibers are included in at least two layers, and adhesive fibers having different melting points of the adhesive component for each layer can be included.

The nonwoven fabric of the present invention preferably has a bonding intersection index A of 1 to 60 pieces / mm ² of the nonwoven fabric described in the following examples. The upper limit of the bonding intersection index A is more preferably 55 pieces / mm ² , still more preferably 50 pieces / mm ² , and particularly preferably 45 pieces / mm ² . The lower limit of the bonding intersection index A is more preferably 3 pieces / mm ² , and even more preferably 5 pieces / mm ² .
The nonwoven fabric in the form of the present invention is preferable because the nonwoven fabric has a better texture when the bonding intersection index A of the nonwoven fabric is within the above range.

In the nonwoven fabric of the present invention, the thickness reduction rate of the nonwoven fabric described in the following examples is preferably 30 to 45%, more preferably 32 to 43%, and more preferably 34 to 41%. Is even more preferred.
The nonwoven fabric in the form of the present invention is preferable because the nonwoven fabric has a better texture when the thickness reduction rate of the nonwoven fabric is within the above range.

In the nonwoven fabric of the present invention, the bending resistance per unit thickness of the nonwoven fabric described in the following examples is preferably 10 to 85 g / mm, more preferably 20 to 70 g / mm, More preferably, it is 30 to 60 g / mm, and particularly preferably 35 to 55 g / mm.
The nonwoven fabric in the form of the present invention is preferable because the nonwoven fabric feels more suitable when the bending resistance per unit thickness of the nonwoven fabric is within the above range.

In the nonwoven fabric of the present invention, the thickness ratio of the nonwoven fabric described in the following examples is, for example, 0.25 to 0.69, preferably 0.25 to 0.67, preferably 0.35 to It is more preferably 0.65, and still more preferably 0.40 to 0.60.
When the thickness ratio of the nonwoven fabric is within the above range, the nonwoven fabric in the form of the present invention is preferable because the softness of the nonwoven fabric is more suitable. Moreover, the thickness ratio of the nonwoven fabric is an index that suggests the ratio of fibers that are oriented in the direction parallel to the thickness direction of the nonwoven fabric (direction perpendicular to the surface of the nonwoven fabric) with respect to the fibers constituting the nonwoven fabric. It is. It shows that the smaller the thickness ratio, the higher the proportion of fibers oriented in a direction parallel to the thickness direction of the nonwoven fabric.

The nonwoven fabric in the form of the present invention preferably has an angle of the fiber bonding point in the middle of the nonwoven fabric of 30 to 90 degrees when the nonwoven fabric described in the following examples is divided into three equal parts in the thickness direction. 60 degrees is more preferable, and 40 to 50 degrees is even more preferable.
When the angle of the fiber bonding point in the middle of a nonwoven fabric is in the above-mentioned range, the nonwoven fabric in the form of the present invention is preferable because the softness of the nonwoven fabric becomes more suitable.

The nonwoven fabric in the form of the present invention preferably has a breaking strength in the MD direction of 10 to 100 N, more preferably 15 to 70 N, and a breaking strength in the CD direction, as described in the following examples. 1 to 25N is preferable, and 2 to 12N is more preferable. The nonwoven fabric in the form of the present invention is preferable because the handleability is further improved when the strength of the nonwoven fabric is within the above range.

In the nonwoven fabric of the present invention, the water retention rate described in the following examples is preferably 800 to 2500%, more preferably 1000 to 2000%, and even more preferably 1100 to 1800%. Preferably, it is 1250 to 1650%. The nonwoven fabric in the form of the present invention is preferable because it has a suitable liquid impregnation property or liquid retention property when the water retention rate of the nonwoven fabric is within the above range.
The nonwoven fabric of the present invention preferably has a water retention rate (water retention rate / thickness) per unit thickness of the nonwoven fabric of preferably 1500 to 3000%, more preferably 1700 to 2800%. Even more preferably, it is 2600%. The thickness of the nonwoven fabric at this time is a thickness obtained by applying a load of 1.96 kPa described later. The nonwoven fabric in the form of the present invention is preferable because it has a suitable liquid impregnation property or liquid retention property when the water retention rate of the nonwoven fabric is within the above range.

In the nonwoven fabric of the present invention, the coefficient of variation CV of the dynamic friction force described in the following examples is, for example, 0.081 or less, preferably 0.070 or less, and more preferably 0.060 or less. Preferably, it is still more preferably 0.055 or less. A preferable lower limit of the coefficient of variation CV of the dynamic friction force is 0.00. When the coefficient of variation CV of the dynamic friction force is within the above range, the nonwoven fabric of the present invention is preferable because the surface of the nonwoven fabric becomes smoother.

The method for producing a nonwoven fabric of the present invention is a method for producing a nonwoven fabric comprising cellulosic fibers and adhesive fibers, wherein the fibers are bonded together by the adhesive fiber, and the fibers are entangled after the bonding step. An entanglement process.

(Nonwoven fabric manufacturing method)
The nonwoven fabric of this embodiment is made by mixing cellulosic fibers, adhesive fibers, and other fibers, if included, to produce a fiber web, and bonding the fibers together with adhesive fibers, so that the bonding location is It can be manufactured by entangled fibers and provided with entangled portions.
The fiber web can be produced by a known method. The form of the fiber web may be any form such as a card web such as a parallel web, a cross web, a semi-random web and a random web, an air lay web, and a wet papermaking web. The shape of the fiber web is preferably a parallel web because the surface of the nonwoven fabric becomes smoother.

In the case of a laminated nonwoven fabric, for example, two fiber webs are prepared, and after the two fiber webs are laminated to obtain one web, the fibers are bonded with adhesive fibers to provide a bonding location, Can be manufactured by providing an entangled portion. In addition, what is necessary is just to include a cellulosic fiber and an adhesive fiber as the whole fiber web.

The fiber web is subjected to an adhesion treatment (or adhesion process). The bonding process may be, for example, a heat treatment (thermal bonding process). According to the heat treatment, the component having the lowest melting point (thermoadhesive component) among the resin components constituting the adhesive fiber can be melted or softened by heating during the heat treatment, and the fibers constituting the fiber web can be bonded to each other. . The heat treatment may be, for example, hot air processing for blowing hot air, hot roll processing (for example, hot embossing roll processing), or heat treatment using infrared rays, but hot air processing is preferable in order to improve the texture of the nonwoven fabric. The hot air processing may be performed using a device that blows hot air having a predetermined temperature onto the fiber web, for example, a hot air through heat treatment machine and a hot air blowing heat treatment machine.

When the bonding treatment is hot air processing, it is preferable to blow hot air multiple times. When hot air is blown a plurality of times, the temperature of the second hot air is preferably higher than the temperature of the first hot air. Since the adhesion between the cellulosic fibers and the adhesive fibers is not higher than the adhesion between the adhesive fibers, hot air can be blown multiple times to further improve the adhesion between the cellulosic fibers and the adhesive fibers. It is valid.

When the bonding treatment is a hot air processing treatment, the wind speed of the hot air is preferably 0.1 to 3.0 m / min from the viewpoint of suppressing fuzz and improving the softness of the texture, and preferably 0.2 to 2 0.5 m / min is more preferable, and 0.3 to 2.0 m / min is even more preferable.

The temperature of the heat treatment may be a temperature at which the component having the lowest melting point (thermal bonding component) among the resin components constituting the adhesive fiber is softened or melted, for example, a temperature equal to or higher than the melting point of the component. For example, when the component having the lowest melting point among the resin components constituting the adhesive fiber is high-density polyethylene, hot air at a temperature of 130 ° C. to 150 ° C. may be blown when performing hot air processing. For example, when the component having the lowest melting point among the resin components constituting the adhesive fiber is an ethylene-acrylic acid copolymer, hot air at a temperature of 90 ° C. to 140 ° C. may be blown when performing hot air processing. In particular, hot air having a temperature of 95 to 130 ° C. may be blown, and more particularly, hot air of 100 to 120 ° C. may be blown. The heat treatment temperature is preferably 0 ° C. or more and 5 ° C. or less higher than the melting point or softening point of the thermal bonding component from the viewpoint of suppressing fuzz and improving the softness of the texture. More preferably, the temperature is higher by not more than 0 ° C., more preferably not less than 2 ° C. and not more than 3 ° C.

The adhesion treatment may be performed by irradiation with an electron beam or the like, or ultrasonic welding. Also by these adhesion treatments, the fibers can be bonded to each other with the resin component constituting the adhesive fibers.

The fiber web after being subjected to the adhesion treatment and before being subjected to the entanglement treatment has sufficient adhesion when the breaking strength is 1.0 N / 5 cm or more in the MD direction, thereby suppressing fluff. Is preferable because it is easy to obtain the nonwoven fabric of the present disclosure. The breaking strength is more preferably 2.0 N / 5 cm or more in the MD direction, and further preferably 3.0 N / 5 cm or more. Further, the fiber web after being subjected to the adhesion treatment and before being subjected to the entanglement treatment, for example, has a softness of texture when the bending resistance obtained by the method described in the examples is 100 g or less. This is preferable because it is easy to obtain the nonwoven fabric of the present disclosure having a good thickness. The bending resistance is more preferably 80 g or less, and further preferably 60 g or less.

The fiber web is further subjected to entanglement processing (or entanglement process). Examples of the entanglement process include a water entanglement process and a water vapor entanglement process, and it is preferable to include any of these. It is preferable that the said entanglement process includes a hydroentanglement process. According to these entanglement treatments, it is easy to entangle with cellulosic fibers, and a nonwoven fabric having desired physical properties can be obtained.

The manufacturing method of the embodiment of the present invention preferably includes a cooling process (or a cooling process) between the bonding process (or the bonding process) and the entanglement process (or the entanglement process). That is, it is preferable that the fiber web is subjected to a cooling process (or a cooling step) after being subjected to the bonding process and before being subjected to the entanglement process. Examples of the cooling step include air cooling or water cooling. When the fiber web after being subjected to the adhesion treatment is not sufficiently cooled, the adhesive component of the adhesive fiber may be in a softened state. When the fiber web is subjected to the entanglement treatment in that state, the bonded portion can be easily peeled off, and the suppression of fuzz of the nonwoven fabric can be insufficient.

Hydroentanglement treatment can be performed by placing a fibrous web on a support and jetting a columnar water stream. Support flat nonwoven surface, and if shall not have irregularities, open area per one does not have an opening of more than 0.2 mm ^2, also projections or pattern is formed It is recommended to use an unsupported support. For example, the support may be a plain weave support of 80 mesh or more and 100 mesh or less.

The hydroentanglement treatment is performed by, for example, supplying a water flow having a water pressure of 1 MPa or more and 15 MPa or less from a nozzle provided with orifices having a hole diameter of 0.05 mm or more and 0.5 mm or less at intervals of 0.3 mm or more and 1.5 mm or less. It can be carried out by spraying 1 to 5 times on each of the front surface and the back surface. The water pressure is preferably 1 MPa or more and 10 MPa or less, more preferably 1 MPa or more and 7 MPa or less.

The support used in the hydroentanglement process may be a plate-shaped or roll-shaped support, and is preferably a roll-shaped support. When the support is in the form of a roll, the fiber web is curved, and the fiber density becomes smaller in the thickness direction of the fiber web (or the outside direction of the normally curved web). When the columnar water flow is jetted from the outside, the confounding by the columnar water flow is relatively easy to proceed. In the nonwoven fabric of the present embodiment, the fiber web is preferably attached in the order of the adhesion treatment and the entanglement treatment. When the fiber web is subjected to the entanglement treatment after the adhesion treatment, the fiber web includes an adhesion portion. Since the entanglement is relatively difficult to proceed, it is preferable to perform the hydroentanglement process in a state where the entanglement is more likely to proceed.

When the bonding process is a hot air processing process, the hydroentanglement process preferably includes injecting a columnar water stream first from the side where hot air is blown in the hot air processing process, and further injecting a columnar water stream from the opposite side. It is preferable to contain. In the hot air processing, the side to which hot air is blown tends to have a lower fiber density than the opposite side (generally the side in contact with the support), and the confounding by the columnar water flow is relatively easy. The degree of suppression of non-woven fabric strength and fuzz due to hydroentanglement is largely dependent on the degree of entanglement in the initial entanglement process, so the entanglement is relatively easy to proceed, and the fiber web fiber density is relatively small from the side It is preferable to carry out by jetting a water stream.

When the entanglement process is a hydroentanglement process, the fiber web is preferably subjected to a drying process (drying process) after the entanglement process. The drying process can be performed by hot air processing or the like that blows hot air. The temperature of the drying treatment is preferably lower than the temperature at which the adhesive component (thermal adhesive component) of the adhesive fiber is softened or melted. The temperature of the drying treatment is preferably 10 ° C. or more lower than the melting point or softening point of the thermal bonding component, more preferably 15 ° C. or more, and even more preferably 20 ° C. or less. . If the adhesive component is not softened or melted again after the entanglement treatment, the bulk of the nonwoven fabric is difficult to loosen and the texture of the nonwoven fabric is difficult to harden.

When two or more adhesive fibers are included, and the melting point or softening point of the thermal adhesive component of each adhesive fiber is different, the melting point or softening point of the thermal adhesive component having a higher melting point or softening point is set to T ₁ (° C.), the melting point or T ₁ , T ₂ , T satisfy the relationship of T ₂ ≦ T <T ₁ , where T ₂ (° C.) is the melting point or softening point of the thermal adhesive component having a lower softening point, and T (° C.) is the temperature of the drying process. It is preferable. In particular, T ≦ T ₁ +10 may be set, more particularly T ≦ T ₁ +15, and even more particularly T ≦ T ₁ +20. When the nonwoven fabric contains two or more adhesive fibers, has a laminated structure, and the melting point or softening point of the heat-bonding component of the adhesive fibers is different for each layer in at least two layers, the temperature of the drying treatment is T ₂ ≦ T <T with _1, the better the texture of the nonwoven fabric in a layer containing the adhesive fibers melting or softening point of T _1, fluffing strength and nonwoven fabric in the layer containing the adhesive fibers melting or softening point of T ₂ Can be improved.

The fiber web is preferably attached in the order of adhesion treatment and entanglement treatment. When the thermal bonding treatment and the entanglement treatment are applied in this order, the entanglement of the fibers proceeds appropriately, and a more suitable softness of the texture can be obtained. It is preferable that the entanglement process is performed continuously after the adhesion process. For example, when the fiber web subjected to the bonding treatment is once wound into a roll shape and then subjected to the entanglement treatment, the softness of the texture is easily reduced by the winding pressure, or the friction between the fiber webs during unwinding Fluffing may occur easily.

In the thermal bonding treatment, heating is preferably performed so that the low melting point component of the adhesive fiber is melted, and more preferably heating is performed so that only the low melting point component is melted. Appropriate melting of the low melting point component can form a more appropriate number and more appropriate number of adhesion points, which can further improve the softness of the nonwoven fabric.
By adjusting the heat treatment temperature, the degree of thermal bonding by the low melting point component (for example, the size and number of bonded portions) can be changed. By adjusting the degree of thermal bonding, the strength of the nonwoven fabric, the suppression of fluff, the softness of the texture, etc. can be further improved, and the degree of entanglement can also be adjusted.

Nonwoven fabrics in the form of the present invention are, for example, disposable diapers, sanitary napkins, incontinence pads, absorbent articles such as panty liners, wiping materials for people or objects, and skin covering materials such as face masks impregnated with cosmetics. , Gauze, disposable clothing and the like. Furthermore, it has an excellent overall balance of properties and is used in direct contact with human skin, such as a liquid-impregnated skin covering material impregnated with a liquid such as top sheets and back sheets for absorbent articles, cosmetics (for example, face) Masks, keratin care sheets, decollete sheets, etc.), base materials for various poultry materials including hot and cold compresses, and wipes for personal use (for example, cleansing sheets, antiperspirant sheets, sanitizing sheets, etc.) Can be used.

Hereinafter, the present invention will be described with reference to examples and comparative examples, but these examples are for explaining the present invention and do not limit the present invention in any way.

The fiber used in order to manufacture the nonwoven fabric of an Example and a comparative example is shown below.
Fiber 1 (cellulosic fiber): Solvent-spun cellulose fiber having a fineness of 1.7 dtex and a fiber length of 40 mm (Lyocell (trade name) manufactured by Renzing). The settling speed is 4 seconds.
Fiber 2 (adhesive fiber): polyethylene terephthalate is the core, high-density polyethylene (melting point: about 133 ° C.) is the sheath, eccentricity having a three-dimensional crimp with a fineness of 2.6 dtex, a fiber length of 51 mm, and an eccentricity of 25% Core-sheath type composite fiber (NBF (SH) V (trade name) manufactured by Daiwabo Polytech Co., Ltd.).
Fiber 3 (adhesive fiber): Polypropylene (melting point 160 ° C.) is the core, and ethylene-acrylic acid copolymer (acrylic acid 8.5 to 10% by mass) (melting point 95 ° C.) is the sheath, Fineness 3. A concentric core-sheath composite fiber (NBF (A) (trade name) manufactured by Daiwabo Polytech Co., Ltd.) having a mechanical crimp of 3 dtex and a fiber length of 51 mm.
Fiber 4 (cellulosic fiber): Cotton having a fineness of 1.0 to 5.0 dtex (average of 2.5 dtex) and a fiber length of 10 to 60 mm (MSD (trade name) manufactured by Marusan Sangyo Co., Ltd.). The sedimentation rate is 10 seconds.
Fiber 5 (cellulosic fiber): Water repellent rayon having a fineness of 1.7 dtex and a fiber length of 40 mm. The sedimentation rate does not sink for more than 5 minutes.

<Manufacture of nonwoven fabrics of Examples 11 to 13>
The fiber web was manufactured using the parallel card machine using the fiber 1 and the fiber 2 with the mixing ratio of 2: 8 (mass ratio). The basis weight of this fiber web was about 35 g / m ² .
The fiber web was heated at 135 ° C. for about 5 seconds using a hot air through heat treatment machine. An air-through nonwoven fabric was obtained in which the fibers were thermally bonded (bonded) with the sheath component of the fibers 2. After the thermal bonding (bonding process), the air-through nonwoven fabric was cooled by air cooling at room temperature of 20 ° C.
The above air-through nonwoven fabric was placed on a plain weave PET net having a warp wire diameter of 0.132 mm, a weft wire diameter of 0.132 mm, and a mesh count of 90 mesh. While advancing the air-through nonwoven fabric at a speed of 4 m / min, a columnar water flow having a water pressure of 2.0 MPa was jetted onto the surface of the air-through nonwoven fabric using a water feeder. The nozzle of the water supply device was provided with orifices having a hole diameter of 0.12 mm at intervals of 0.6 mm. The distance between the surface of the air-through nonwoven fabric and the orifice was 15 mm. Thereafter, a columnar water flow was jetted onto the back surface of the air-through nonwoven fabric in the same manner using a water feeder. The fibers were hydroentangled (entangled) as described above. The nonwoven fabric (single layer) of Example 11 was obtained by performing a drying process using a hot-air through heat treatment machine set at 80 ° C. after the entanglement process.
A nonwoven fabric of Example 12 was obtained in the same manner as in Example 11 except that a columnar water flow having a water pressure of 3.0 MPa was sprayed on the front surface and the back surface (both surfaces).
A nonwoven fabric of Example 13 was obtained in the same manner as in Example 11 except that a columnar water flow having a water pressure of 3.5 MPa was sprayed on the front surface and the back surface.

<Manufacture of nonwoven fabrics of Examples 21 to 23>
A nonwoven fabric of Example 21 was obtained in the same manner as in Example 11, except that Fiber 1 and Fiber 2 were used at a 4: 6 mixing ratio.
A nonwoven fabric of Example 22 was obtained in the same manner as in Example 21, except that a columnar water flow having a water pressure of 3.0 MPa was jetted onto the front surface and the back surface.
A nonwoven fabric of Example 23 was obtained in the same manner as in Example 21 except that a columnar water flow having a water pressure of 3.5 MPa was sprayed on the front surface and the back surface.

<Manufacture of nonwoven fabrics of Examples 31 to 33>
Nonwoven fabrics of Examples 31 to 33 were obtained in the same manner as in Examples 21 to 23 except that the fibers 1 and 2 were used at a mixing ratio of 6: 4.
<Manufacture of nonwoven fabrics of Examples 41 to 43>
Nonwoven fabrics of Examples 41 to 43 were obtained in the same manner as in Examples 21 to 23 except that the fibers 1 and 2 were used at a mixing ratio of 8: 2.

<Manufacture of the nonwoven fabric of Comparative Example 50>
A non-woven fabric of Comparative Example 50 was obtained using the same method as in Example 11 except that Fiber 1 and Fiber 2 were used at a mixing ratio of 6: 4, and the treatment using water flow and the drying treatment were not performed.
<Manufacture of non-woven fabrics of Comparative Examples 61-62>
A nonwoven fabric of Comparative Example 61 was obtained using the same method as Example 11 except that Fiber 1 and Fiber 2 were used at a mixing ratio of 6: 4, and heat treatment (adhesion treatment) and cooling treatment were not performed.
A non-woven fabric of Comparative Example 62 was obtained using the same method as Comparative Example 61 except that a water flow having a water pressure of 3.0 MPa was used for the front and back surfaces.

<Manufacture of non-woven fabrics of Comparative Examples 71 to 72>
A fiber web was produced using fibers 1 and 2 in a 6: 4 blend ratio.
A method similar to that in Example 11 was used except that a columnar water flow having a water pressure of 2.0 MPa was sprayed on the front and back surfaces of the fiber web, respectively, and then heat-treated at 135 ° C. for about 5 seconds using a hot air through heat treatment machine. Thus, a nonwoven fabric of Comparative Example 71 was obtained.
A nonwoven fabric of Comparative Example 72 was obtained using the same method as Comparative Example 71, except that a columnar water flow having a water pressure of 3.0 MPa was sprayed to the front and back surfaces.

<Manufacture of the nonwoven fabric of Example 81>
Fibers 1 and 2 were prepared at 6: 4 (mass ratio), and each fiber web was manufactured using a parallel card machine using only each of the fibers. Total basis weight of the two fiber webs was about 35 g / ^{m 2.}
The fiber web obtained by laminating and laminating the two fiber webs was heated at 135 ° C. for about 5 seconds using a hot-air through heat treatment machine. An air-through nonwoven fabric was obtained in which the fibers were thermally bonded (bonded) with the sheath component of the fibers 2. The hot air was applied from the side of the fiber web containing the fibers 1. After heat bonding (bonding treatment), the air-through nonwoven fabric was cooled by air cooling at a room temperature of 20 ° C.
The above air-through nonwoven fabric was placed on a plain weave PET net having a warp wire diameter of 0.132 mm, a weft wire diameter of 0.132 mm, and a mesh count of 90 mesh. While advancing the air-through nonwoven fabric at a speed of 4 m / min, a columnar water flow having a water pressure of 3.0 MPa was jetted onto the surface of the air-through nonwoven fabric (on the side containing the fiber 1) using a water supply device. The nozzle of the water supply device was provided with orifices having a hole diameter of 0.12 mm at intervals of 0.6 mm. The distance between the surface of the air-through nonwoven fabric and the orifice was 15 mm. Thereafter, a columnar water flow was jetted onto the back surface of the air-through nonwoven fabric in the same manner using a water feeder. The fibers were hydroentangled (entangled) as described above. After the entanglement treatment, a drying treatment was performed using a hot-air through heat treatment machine set at 80 ° C. to obtain a nonwoven fabric (lamination) of Example 81.

<Manufacture of the nonwoven fabric of Example 82>
The fiber web A was manufactured using the parallel card machine using the fiber 1 and the fiber 2 at a mixing ratio of 7: 3 (mass ratio). The basis weight of the fiber web A was about 17.5 g / m ² . Next, the fiber web B was manufactured using the parallel card machine using the fiber 1 and the fiber 2 with the mixing ratio of 5: 5 (mass ratio). The basis weight of the fiber web B was about 17.5 g / m ² .
The fiber web obtained by laminating and laminating the two fiber webs was heated at 135 ° C. for about 5 seconds using a hot-air through heat treatment machine. An air-through nonwoven fabric was obtained in which the fibers were thermally bonded (bonded) with the sheath component of the fibers 2. The hot air was applied from the fiber web A side. After heat bonding (bonding treatment), the air-through nonwoven fabric was cooled by air cooling at a room temperature of 20 ° C.
The above air-through nonwoven fabric was placed on a plain weave PET net having a warp wire diameter of 0.132 mm, a weft wire diameter of 0.132 mm, and a mesh count of 90 mesh. While advancing the air-through nonwoven fabric at a speed of 4 m / min, a columnar water flow having a water pressure of 2.0 MPa was jetted onto the surface of the air-through nonwoven fabric (on the side of the fiber web A) using a water feeder. The nozzle of the water supply device was provided with orifices having a hole diameter of 0.12 mm at intervals of 0.6 mm. The distance between the surface of the air-through nonwoven fabric and the orifice was 15 mm. Thereafter, a columnar water flow was jetted onto the back surface of the air-through nonwoven fabric in the same manner using a water feeder. The fibers were hydroentangled (entangled) as described above. After the entanglement treatment, a drying treatment was performed using a hot-air penetrating heat treatment machine set at 80 ° C. to obtain a nonwoven fabric (lamination) of Example 82. In the entire nonwoven fabric of Example 82, the mixing ratio of the fibers 1 and 2 was 6: 4 (mass ratio).

<Manufacture of the nonwoven fabric of Example 83>
A nonwoven fabric of Example 83 was obtained using the same method as Example 82, except that hot air was applied from the side of the fiber web B and a columnar water flow was jetted first from the side of the fiber web B.

<Manufacture of Nonwoven Fabrics of Examples 84 to 86>
Instead of fiber 1 and fiber 2, the same method as in Example 31 was used, except that fiber 1 and fiber 3, fiber 4 and fiber 2, and fiber 5 and fiber 2 were each used at a mixing ratio of 6: 4. The nonwoven fabrics (single layers) of Examples 84 to 86 were obtained.

The nonwoven fabric was evaluated as follows.
<Nonwoven fabric structure>
The structure of the non-woven fabric is obtained by cutting the non-woven fabric in the longitudinal direction (more specifically, in the direction parallel to the traveling direction of the belt conveyor of the heat treatment machine and the water flow processing machine that has processed the non-woven fabric), and the cut surface is scanned with an electron microscope (SEM , Magnification: 60 times). The results are shown in Tables 1-2.
The SEM image of the nonwoven fabric of Example 31 is shown in FIG. It can be seen that the nonwoven fabric of Example 31 has a dense / sparse / dense structure in which the number of fibers inside the nonwoven fabric is smaller than the number of fibers on the front and back surfaces.
The SEM image (magnification: 25 times) of the nonwoven fabric of the comparative example 50 is shown in FIG. It can be seen that the nonwoven fabric of Comparative Example 50 has substantially no difference in the number of fibers inside the nonwoven fabric and the number of fibers on the front and back surfaces, and does not have a dense / sparse / dense structure.

<Adhesion point angle measurement>
About the image | photographed SEM image, the angle | corner which two fibers which form an adhesion point make apparent was investigated about the surface of the nonwoven fabric when the nonwoven fabric was divided into 3 equal parts in the thickness direction, the back surface vicinity, and the middle vicinity (inside). The average value was determined by examining the corners formed by at least four locations. The results are shown in Tables 1 and 2. In addition, about the Example and comparative example which processed with the hot air penetration type heat processing machine, the surface which applied hot air was made into the surface, and the surface on the opposite side was made into the back surface.

　式中、
　　α_ｉは、ｉ番目の非接着性繊維の混率（質量％）を表し、
　　ｘ_ｉは、ｉ番目の非接着性繊維の繊度（dtex）を表し、
　　β_ｊは、ｊ番目の接着性繊維の混率（質量％）を表し、
　　ｙ_ｊは、ｊ番目の接着性繊維の繊度（dtex）を表す。
　接着交点数Ｉと接着交点割合Ｐとから、接着交点指数Ａ（単位：個／ｍｍ^２）を下記の式に従って求めた。
　　　　　接着交点指数Ａ＝Ｉ／（Ｐ^２） <Adhesion intersection index A>
The front and back surfaces of the nonwoven fabric were observed with a scanning electron microscope (SEM, acceleration voltage: 10.0 kV, magnification: 100 times). For the photographed SEM images, the number of fiber bonding intersections per area was counted. The number of fiber bonding intersections was counted for a total of 6 SEM images, 3 for each of the front and back surfaces of the nonwoven fabric, and the average value was defined as the number I of fiber bonding intersections (unit: pieces / mm ² ).
From the fineness (dtex) of the non-adhesive fiber (fiber 1) and the adhesive fiber (fiber 2) constituting the nonwoven fabrics of Examples and Comparative Examples and the mixing ratio (% by mass) in the nonwoven fabric, the adhesion intersection ratio P (0 ≦ P ≦ 1) was determined according to the following formula.

Where
α _i represents the mixing ratio (% by mass) of the i-th non-adhesive fiber,
x _i represents the fineness (dtex) of the i-th non-adhesive fiber,
β _j represents the mixing ratio (% by mass) of the j-th adhesive fiber,
y _j represents the fineness (dtex) of the j-th adhesive fiber.
From the number I of adhesion intersections and the adhesion intersection ratio P, the adhesion intersection index A (unit: pieces / mm ² ) was determined according to the following formula.
Adhesion intersection index A = I / (P ² )

In the case of a two-layer structure, the adhesion intersection ratio P on the front surface or the back surface is calculated according to the mixed cotton state on the front surface or the back surface. The calculation of the adhesion intersection index A is still an average value of three front surfaces and three back surfaces. In the case of Example 81, the bonding intersection index A of the surface of the fiber 1 is 0 (I = 0). The adhesion intersection index A of the surface of the fiber 2 is 28 (P = 1). On average, the adhesion intersection index A of Example 81 is 14.

<Thickness and density of nonwoven fabric>
Using a thickness measuring machine (THICKNESS GAUGE model CR-60A (trade name) manufactured by Daiei Kagaku Seisakusho Co., Ltd.), the thickness of the nonwoven fabric was measured while a load of 1.96 kPa was applied to the nonwoven fabric.
Alternatively, using a CCD laser displacement meter (amplifier unit type: LK-2100, sensor head type: LK-080, manufactured by Keyence Corporation), the thickness of the nonwoven fabric was measured in a state where a load of 40 Pa was applied to the nonwoven fabric. The results are shown in Tables 1-2.
The density of the nonwoven fabric was calculated based on the basis weight of the nonwoven fabric and the thickness of the nonwoven fabric obtained by applying a load of 40 Pa.
The ratio of the thickness obtained by applying a load of 1.96 kPa to the thickness obtained by applying a load of 40 Pa (thickness obtained by applying a load of 1.96 kPa / thickness obtained by adding a load of 40 Pa Is defined as “thickness ratio”.

<Nonwoven fabric thickness reduction rate>
About the sample piece of the nonwoven fabric, the thickness (initial thickness) of the nonwoven fabric in a state where a load of 40 Pa was applied was measured in the same manner as described above. Next, after leaving the same sample piece for 3 days under a load of 1.63 kPa, the thickness of the nonwoven fabric in a state where a load of 40 Pa was applied in the same manner as described above except for a load of 1.63 kPa. The thickness (final thickness) was measured. The thickness reduction rate (%) was determined according to the following formula.
Thickness reduction rate (%) = [(initial thickness−final thickness) / initial thickness] × 100

<Bending softness>
The bending resistance of the nonwoven fabric was measured according to JIS L 1096: 2010 8.21.5 E method (handle ohmmeter method). Specifically, it measured by the following procedure.
A test piece of 20 cm in length and 20 cm in width was placed on a sample stage so that the measurement direction of the test piece was perpendicular to the slot (gap width 10 mm).
Next, the penetrator blade adjusted so as to be lowered to 8 mm from the surface of the sample stage was lowered to press the test piece. When pressed, the resistance value against pressing was read at a position of 6.7 cm (one third of the width of the test piece) from one of the sides, at different positions in the vertical and horizontal directions. As the resistance value, the maximum value indicated by the microammeter was read. The total value of the maximum values of the four sides was obtained, and the average value of the total value was calculated three times to obtain the bending resistance (g) of the sample.
Further, the value obtained by dividing the bending resistance by the thickness (value obtained by applying a load of 1.96 kPa) is the bending resistance per unit thickness (the bending resistance / thickness (g / mm)). Defined.

<Strong elongation>
The strength and elongation were measured according to JIS L 1096: 2010 8.14.1 A method (strip method). Using a constant-speed tension type tensile tester, a tensile test was performed under the conditions of a sample piece (nonwoven fabric) width of 5 cm, a gripping interval of 10 cm, and a tensile speed of 30 ± 2 cm / min. The load value at break (breaking strength), breaking elongation, 10% elongation stress, 20% elongation stress and 30% elongation stress were measured. The tensile test was carried out with the longitudinal direction (MD direction) and the lateral direction (CD direction) of the nonwoven fabric as the tensile direction. The evaluation results are shown as the average of the values measured for three samples.

<Maximum frictional force and dynamic frictional force>
The maximum frictional force and dynamic frictional force were measured using a static / dynamic friction measuring machine (Tribomaster TL201Ts, manufactured by Trinity Lab Co., Ltd.). A 5 cm × 10 cm non-woven fabric was prepared as a sample piece. In addition, the sample piece which prepared the thing whose MD direction of a nonwoven fabric becomes a long side, and the thing whose CD direction becomes a long side, respectively were prepared. A tactile contact (manufactured by Trinity Lab Co., Ltd.) was used as the contact terminal of the measuring instrument. The sample piece was fixed to a measuring machine, and the contact terminal was moved back and forth twice with respect to the surface of the sample piece at a load of 30 g, a speed of 10 mm / sec, and a distance of 30 mm. In addition, about the Example and comparative example which processed with the hot air penetration type heat processing machine, the contact terminal was made to contact the surface opposite to the surface which applied hot air, and it measured. The numerical value at the second round-trip was read, and the average value of the forward value and the reverse value was taken as the maximum frictional force (gf) and dynamic frictional force (gf) of one sample piece. The test piece having the long side in the MD direction is measured three times, and the test piece having the long side in the CD direction is measured three times, and the average value of the total six measurement values is determined as the maximum frictional force of each example and comparative example. Fs (gf) and dynamic friction force Fk (gf) were used.
Further, the coefficient of variation CV of the dynamic friction force was obtained from the standard deviation σ (gf) of the dynamic friction force obtained at the time of measurement and the average value Fk of the dynamic friction force described above according to the following equation.
Coefficient of variation of dynamic friction force CV = σ / Fk

<Water retention rate>
The nonwoven fabric was cut into MD direction × CD direction = 100 mm × 100 mm, and the mass of the nonwoven fabric was measured. Then, the nonwoven fabric was added to test distilled water (2 drops of dish detergent (Joy clean orange fragrance (with 33% surfactant), manufactured by Procter & Gamble Co.) per 1 liter of distilled water). Soaked for 2 minutes. The three corners of the nonwoven fabric impregnated with distilled water for test were hung with clothespins. After 10 minutes, the mass of the nonwoven fabric (including water) was measured. The water retention rate of the nonwoven fabric was calculated according to the following formula.
Water retention rate (%) = [(M2-M1) / M1] × 100
M1: Mass of the nonwoven fabric before being immersed in test distilled water (g)
M2: The mass (g) of the nonwoven fabric after suspending the nonwoven fabric soaked in test distilled water for 10 minutes

<Fuzzy evaluation>
The surface of the disk (diameter 70 mm, 350 g) was covered with 0.5 mm thick urethane foam. The disk was attached to the rotating shaft at a position where the center of the disk was displaced 20 mm from the rotating shaft. A non-woven fabric with urethane foam underneath was fixed on the table. The disk was placed on the nonwoven fabric, and the rotating shaft was rotated to rotate the disk on the nonwoven fabric. Circulation was performed twice clockwise and twice counterclockwise. The circumferential speed at this time was about 3 seconds per round. About the nonwoven fabric after a round motion, the fluff state was evaluated with the following criteria. In Nos. 3 to 5, it is considered that fluff is suppressed.
5: Very good (no fuzz)
4: Good (very little fuzz)
3: Normal (there is a little fuzzy)
2: Bad (fuzz is worrisome)
1: Very bad (a lot of fuzz)

<Fuzzy evaluation 2>
Evaluation was made by an Abrasion Test using a Martindale Fluff Tester (manufactured by James Heal, trade name “Martindale Abrasion and Pilling Tester No. 1309”).
Two samples (each having a diameter of 140 mm and a diameter of 38 mm) were prepared for the nonwoven fabrics of Examples and Comparative Examples. A felt having a diameter of 140 mm was set on an Abrading Table, a sample having a diameter of 140 mm was laminated on an SM25 Abrasice Cloth, and the sample was fixed by a clamping ring. Next, a sample having a diameter of 38 mm and a polyurethane having a diameter of 38 mm were placed in a sample holder. The measurement conditions were that the sample holder was placed on the table (Abrading Tables) without placing the loading weight on the sample holder. The friction test was conducted with the number of frictions set to 8 and the motion set to 60.5 mm Lissajous. In addition, about the Example and comparative example which processed with the hot air penetration type heat processing machine, the friction test was done so that the surface on the opposite side to the side which applied hot air may contact. After the measurement was completed, the nonwoven fabric on the sample holder side was observed, and the fluff state was determined from the following two criteria (the state when the nonwoven fabric was measured from the top (surface state) and the nonwoven fabric after the measurement was viewed from the side. Evaluation was made with the sum of the time (fuzzing condition)) (up to 10 points). A total of 6 or more points is considered to be suppressed fluff. For each example or comparative example, an evaluation test was performed three times, and the average of the three scores was used as the fluff evaluation of each example or comparative example.
Surface condition 5: Very good (no surface disturbance)
4: Good (surface disturbance is very small)
3: Normal (Surface disturbance is small, not bothering)
2: Poor (the degree of surface disturbance is worrisome)
1: Very bad (holes on the surface)
Fluff condition 5: Very good (no fuzz)
4: Good (very little fuzz)
3: Ordinary (there is a degree that I don't mind fuzzing)
2: Bad (they are worried about fuzzing)
1: Very bad (a lot of fuzz)
For fluff, there are two evaluation methods, <Fuzzy evaluation> and <Fuzzy evaluation 2>. If <Fuzzy evaluation> is 3 or more, it is acceptable, and <Fuzzy evaluation 2> is 6 or more in total. If there is, it is a pass. Furthermore, if any one of <Fuzzy evaluation> and <Fuzzy evaluation 2> passes, it is considered that the fuzz is passed. If both <Fuzzy evaluation> and <Fuzzy evaluation 2> pass, it is more preferable for the fuzz.

Each of the nonwoven fabrics of Examples 11 to 43 and 81 to 86 includes a cellulosic fiber and an adhesive fiber, and includes an adhesive portion between the adhesive fiber and the cellulosic fiber and / or the adhesive fiber. The entanglement location of a system fiber, a cellulosic fiber, and / or adhesive fiber is included. Furthermore, the nonwoven fabrics of Examples 11 to 43 and 81 to 86 all have (i) an adhesive intersection point index A of 1 to 60 pieces / mm ² and / or (ii) a thickness of the nonwoven fabric. The reduction rate is 30 to 45%.

Since the nonwoven fabrics of Examples 11 to 43 and 81 to 86 include both the adhesion part and the entanglement part, the suppression of fluff is good.
Furthermore, the nonwoven fabrics of Examples 11 to 43 and 81 to 86 are good because the above-mentioned specific values are exhibited by any of the above (i) and (ii).
Therefore, the nonwoven fabrics of Examples 11 to 43 and 81 to 86 exhibit excellent properties such as fluff suppression and good texture.

On the other hand, the nonwoven fabrics of Comparative Examples 50 to 72 are never good in fluff suppression and texture. For example, the comparative examples 50 to 62 have only one of the bonded portion and the entangled portion. Therefore, the suppression of fluff is insufficient. Since Comparative Examples 71 to 72 have both the adhesion part and the entanglement part, the suppression of the fluff is good, but since any of (i) and (ii) does not show the specific value described above, the texture is Is hard and insufficient.

When the bending resistance per unit thickness of the nonwoven fabric is confirmed, the nonwoven fabric values of Comparative Example 71 and Comparative Example 72 are larger than those of Examples 11 to 43 and 81 to 86, and the nonwoven fabric of the example is more The texture is soft and good.

As for the thickness ratio of the nonwoven fabric, Examples 31 to 33 and Comparative Examples 71 to 72 having the same mixing ratio confirmed that the value of the nonwoven fabric of the comparative example was larger than that of the nonwoven fabric of the example. The texture is soft and good. Further, when Examples 31 to 33 having the same mixing ratio are compared with Comparative Example 50, the value of the non-woven fabric of the comparative example is smaller than that of the non-woven fabric of the example, and the non-woven fabric of the example is more difficult to sag.

Regarding the angle of the fiber bonding point in the middle when the nonwoven fabric is divided into three equal parts, when Example 31 having the same mixing ratio, Comparative Example 50 and Comparative Example 71 are confirmed, it is compared with the nonwoven fabric of Example 31. The value of the nonwoven fabric of Example 71 is smaller, and the nonwoven fabric of the example is softer and better in texture. Moreover, the value of the non-woven fabric of Comparative Example 50 is larger than that of the non-woven fabric of Example 31, and the non-woven fabric of the example is more difficult to sag. Moreover, since Example 84 which uses the fiber of a mechanical crimp as an adhesive fiber had a small value of an angle, it is thought that the direction in which an adhesive fiber has a three-dimensional crimp can make a texture softer.

Regarding the coefficient of variation of the dynamic friction force of the nonwoven fabric, when Examples 11, 21, 31 and 41 having the same water pressure and Comparative Example 71 were confirmed, the nonwoven fabric of the Example had a smaller value than the nonwoven fabric of the Comparative Example. The nonwoven fabric has a smoother surface. Similarly, in Examples 12, 22, 32 and 42 and Comparative Example 72 having the same water pressure, the nonwoven fabric of the example has a smoother surface. It is presumed that the fiber entanglement is moderated and the surface of the nonwoven fabric can be smoothed by performing the adhesion step before the entanglement step. In particular, since the fiber web was manufactured by a parallel card machine in the examples and comparative examples, the fibers were relatively oriented in the MD direction, and the fiber orientation was relatively maintained by performing the bonding process before the entanglement process, and the nonwoven fabric. It is inferred that the surface of was smoother.

About the nonwoven fabric of Example 31, a nonwoven fabric is cut | disconnected in the horizontal direction (More specifically, the heat treatment machine which processed the nonwoven fabric, and the orthogonal direction with the advancing direction of the belt conveyor of a water-flow processing machine), and the cut surface is a scanning electron microscope. (SEM, magnification: 100 times). FIG. 3 is a cut portion obtained by enlarging the vicinity (inside) of the nonwoven fabric when the nonwoven fabric is divided into three equal parts in the thickness direction. In the nonwoven fabric of Example 31, the bonded portion by the adhesive fiber is present inside the nonwoven fabric. It can be seen that the removed adhesive peeling trace is formed on the adhesive fiber.
About the nonwoven fabric of Example 31, the surface and the back surface of the nonwoven fabric were observed with a scanning electron microscope (SEM, magnification: 100 times). FIG. 4 shows an observation of the surface of the nonwoven fabric, and the nonwoven fabric of Example 31 shows that the adhesive fibers are formed with adhesive delamination marks on the surface of the nonwoven fabric in which the adhesion sites due to the adhesive fibers have been eliminated. Recognize. Moreover, FIG. 5 observes the back surface of a nonwoven fabric, and as for the nonwoven fabric of Example 31, the adhesive peeling trace by which the adhesion location by adhesive fiber was eliminated is formed in the adhesive fiber in the back surface of a nonwoven fabric. I understand that.

When Example 31 and Example 85 having different cellulosic fibers were compared, Example 31 using lyocell had higher breaking strength than Example 85 using cotton, and 10%, 20%, and 30% in the MD direction. The stress at elongation was high. The fluff evaluation was also high in Example 31. It is estimated that lyocell has extremely small variations in fineness and fiber length, and the nonwoven fabric strength and fluff are relatively good.

In addition, when Example 31 and Example 86 having different cellulosic fibers were compared, Example 31 using lyocell had higher breaking strength than Example 86 using rayon having water repellency, 10%, 20%, The stress at 30% elongation was high. The fluff evaluation was also high in Example 31. The lyocell having a sedimentation speed of about 4 seconds is presumed to have relatively good nonwoven fabric strength and fluff because the entanglement due to the columnar water flow is relatively stronger than the water-repellent rayon. On the other hand, Example 86 had lower maximum frictional force and dynamic frictional force than Example 31, and the slipperiness of the nonwoven fabric surface was relatively good.

When Example 31 and Example 84 in which the sheath component of the adhesive fiber was different were compared, Example 84 had high stress at 10%, 20%, and 30% in the MD direction. It is presumed that the strength of the nonwoven fabric is improved by using, as the sheath component, a resin having high adhesiveness to cellulosic fibers such as an ethylene-acrylic acid copolymer.

In the laminated structure, when Example 82 and Example 83 with slightly different nonwoven fabric manufacturing methods were compared, Example 83 had a better evaluation of fluff. The layer to which hot air is applied tends to have a lower fiber density than the opposite layer (the layer in contact with the support), and the entanglement by the columnar water flow is relatively advanced. On the other hand, since the entanglement of the opposite layer is relatively difficult to proceed, it is presumed that the entanglement is relatively strong and the fluff is less likely to occur when the cellulose-based fiber content in the opposite layer is higher.

The present disclosure includes the following aspects.
(Aspect 1)
A nonwoven fabric comprising cellulosic fibers and adhesive fibers,
Including an adhesion point between the adhesive fiber and the cellulosic fiber and / or the adhesive fiber,
Including an entangled portion of the cellulosic fiber and cellulosic fiber and / or adhesive fiber,
The bonding intersection index A of the nonwoven fabric is 1 to 60 pieces / mm ² .
Non-woven fabric.
(Aspect 2)
A nonwoven fabric comprising cellulosic fibers and adhesive fibers,
Including an adhesion point between the adhesive fiber and the cellulosic fiber and / or the adhesive fiber,
Including an entangled portion of the cellulosic fiber and cellulosic fiber and / or adhesive fiber,
The thickness reduction rate of the nonwoven fabric is 30 to 45%.
Non-woven fabric.
(Aspect 3)
The nonwoven fabric according to any one of aspects 1 and 2, wherein the cellulosic fiber is contained in an amount of 25 to 75% by mass.
(Aspect 4)
A method for producing a nonwoven fabric comprising cellulosic fibers and adhesive fibers, comprising: an adhesion step of bonding fibers together with the adhesive fibers; and an entanglement step of interlacing fibers after the adhesion step Production method.
(Aspect 5)
The manufacturing method of the nonwoven fabric of aspect 4 which includes a cooling process between the said adhesion process and the said entanglement process.
(Aspect 6)
The manufacturing method of the nonwoven fabric of the aspect 4 or 5 in which the said entanglement process includes a hydroentanglement process.
(Aspect 7)
The manufacturing method of the nonwoven fabric according to aspect 6, wherein the bonding step includes hot air processing, and in the hydroentanglement step, the columnar water flow is sprayed first from the side where hot air is blown.
(Aspect 8)
A drying process is included after the said hydroentanglement process, The temperature of the said drying process is a temperature 10 degreeC or more lower than the temperature which softens or melt | dissolves the adhesive component of adhesive fiber, The aspect 6 or 7 Nonwoven fabric manufacturing method.
(Aspect 9)
Including a drying step after the hydroentanglement treatment,
The adhesive fiber includes two or more adhesive fibers having different melting points or softening points of the adhesive component,
The melting point or softening point T ₁ (° C.) of the thermal bonding component having a higher melting point or softening point, the melting point or softening point T ₂ (° C.) of the thermal bonding component having a lower melting point or softening point, and the temperature T ( ° C) satisfy the relationship of T ₂ ≦ T <T ₁ .

The nonwoven fabric of the present disclosure alleviates at least one of the problems such as insufficient suppression of fluff and hard texture, preferably solves the problem, and is used for applications that directly touch human skin, such as absorbent articles be able to.

Related Application In addition, this application claims priority based on Article 4 of the Paris Convention based on application number 2018-018501 filed in Japan on February 5, 2018. The contents of this basic application are incorporated herein by reference.

Claims (9)

A nonwoven fabric comprising cellulosic fibers and adhesive fibers,
Including an adhesion point between the adhesive fiber and the cellulosic fiber and / or the adhesive fiber,
Including an entangled portion of the cellulosic fiber and cellulosic fiber and / or adhesive fiber,
The bonding intersection index A of the nonwoven fabric is 1 to 60 pieces / mm ² .
Non-woven fabric. A nonwoven fabric comprising cellulosic fibers and adhesive fibers,
Including an adhesion point between the adhesive fiber and the cellulosic fiber and / or the adhesive fiber,
Including an entangled portion of the cellulosic fiber and cellulosic fiber and / or adhesive fiber,
The thickness reduction rate of the nonwoven fabric is 30 to 45%.
Non-woven fabric. The nonwoven fabric according to claim 1, wherein the cellulose fiber is contained in an amount of 25 to 75% by mass. A method for producing a nonwoven fabric comprising cellulosic fibers and adhesive fibers, comprising: an adhesion step of bonding fibers together with the adhesive fibers; and an entanglement step of interlacing fibers after the adhesion step Production method. The manufacturing method of the nonwoven fabric of Claim 4 including a cooling process between the said adhesion process and the said entanglement process. The method for producing a nonwoven fabric according to claim 4 or 5, wherein the entanglement step includes a hydroentanglement process. The method for producing a nonwoven fabric according to claim 6, wherein the bonding step includes hot air processing, and in the hydroentanglement step, a columnar water flow is sprayed first from the side where hot air is blown. 8. The method according to claim 6, further comprising a drying step after the hydroentanglement treatment, wherein a temperature of the drying step is lower by 10 ° C. or more than a temperature at which the adhesive component of the adhesive fiber is softened or melted. Manufacturing method of non-woven fabric. Including a drying step after the hydroentanglement treatment,
The adhesive fiber includes two or more adhesive fibers having different melting points or softening points of the adhesive component,
The melting point or softening point T ₁ (° C.) of the adhesive component having a higher melting point or softening point, the melting point or softening point T ₂ (° C.) of the adhesive component having a lower melting point or softening point, and the temperature T (° C.) of the drying treatment DOO satisfies the relation of T ₂ ≦ T <T _1, the manufacturing method of the nonwoven fabric according to claim 6 or 7.

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