JP5530023B1 - Non-woven - Google Patents

Abstract

An object of the present invention is to provide a non-woven fabric having improved cushioning properties and improved liquid permeability and which is difficult to reverse the liquid.
[Solution]
The nonwoven fabric 1 of the present invention is a hydrophilic nonwoven fabric comprising a fiber assembly 11 in which long fibers 2 are fixed by a heat fusion part 3. In the nonwoven fabric 1, a part of the long fiber 2 is broken, one end portion 20a is fixed by the heat-sealing portion 3, and the other end portion becomes a free end portion 20b so as to stand apart from the fiber assembly 11. Fiber 20 having a free end 20b. The hydrophilicity of the fiber 20 having the free end portion 20b is lower than the hydrophilicity of the fiber constituting the fiber assembly 11.
[Selection] Figure 1

Description

  The present invention relates to a nonwoven fabric containing long fibers.

  For example, for absorbent articles such as disposable diapers, spunbond nonwoven fabrics and nonwoven fabrics with low weights (air-through nonwoven fabrics and heat roll nonwoven fabrics) are frequently used because they have high breaking strength, excellent processing suitability, and are economical. Yes. However, the spunbonded nonwoven fabric and the like have a lack of plumpness due to its manufacturing method, and it has been difficult to improve the touch.

  The present applicant has previously proposed a non-woven fabric comprising fibers in which a part of a long fiber is broken, only one end is fixed by a heat-sealed portion, and the free end on the other end is thickened. (See Patent Document 1). According to the nonwoven fabric described in Patent Document 1, although the breaking strength is high, there is a feeling of plumpness as a whole, cushioning properties are improved, and touch is improved.

  As another technique, for example, in Patent Document 2, a surfactant is applied to the back side of the sheet without changing the density of the constituent fibers of the liquid-permeable top sheet, and the back side is more than the front side. An absorbent article provided with a liquid-permeable surface sheet imparted with high hydrophilicity on the side is described.

JP 2012-92475 A Japanese Patent Laying-Open No. 2005-87659

  However, in Patent Document 1, when the nonwoven fabric described in Patent Document 1 is used for a surface sheet of an absorbent article such as a disposable diaper, for example, the viewpoint of quickly transferring the body fluid absorbed by the surface sheet to the absorber side, There is no description regarding the viewpoint that the bodily fluid once absorbed by the absorbent body is difficult to reverse through the surface sheet. In addition, there is a trade-off relationship between the improvement in liquid permeability for quickly transferring the absorbed body fluid to the absorber side and the difficulty in returning the fluid that has been absorbed at once, and it is difficult to achieve both. Thus, there was a further need to improve both liquid permeability and difficulty in returning the liquid.

  In addition, Patent Document 2 does not describe anything about raising of fibers, and the liquid-permeable surface sheet described in Patent Document 2 is a sheet inferior in overall cushioning properties. Moreover, since the liquid-permeable surface sheet described in Patent Document 2 is simply applied with a surfactant without physically changing the density of the constituent fibers, the liquid permeability allows the body fluid to move to the absorber side. It is difficult to improve.

  Accordingly, an object of the present invention is to provide a nonwoven fabric that has improved cushioning properties and that makes it difficult to reverse the liquid while improving the liquid permeability.

  The present invention is a hydrophilic non-woven fabric comprising a fiber assembly in which long fibers are fixed by a heat-sealing part, wherein a part of the long fibers is broken and one end part is fixed by the heat-sealing part. A fiber having the free end portion standing up away from the fiber assembly, the other end portion being a free end portion, the hydrophilicity of the fiber having the free end portion being the fiber assembly The nonwoven fabric which is lower than the hydrophilicity of the fiber which comprises is provided.

  According to the nonwoven fabric of the present invention, the cushioning property is improved, the liquid permeability is improved, and the liquid is difficult to reverse.

FIG. 1 is a perspective view showing a nonwoven fabric according to this embodiment of the present invention. FIG. 2 is a perspective view showing a fiber having a thick free end portion of the nonwoven fabric shown in FIG. FIG. 3 is a schematic view showing a method of measuring the tip fiber diameter of the nonwoven fabric shown in FIG. FIG. 4 is a schematic view showing a method for measuring the number of fibers raised in the nonwoven fabric shown in FIG. FIG. 5 is a schematic view showing a preferred production apparatus used in the method for producing a nonwoven fabric of the present invention. FIG. 6 is a schematic diagram showing a partially stretched portion provided in the manufacturing apparatus shown in FIG. 7 is an enlarged cross-sectional view of a main part of the partially stretched portion shown in FIG. FIG. 8 is a schematic diagram illustrating a raised processing portion provided in the manufacturing apparatus illustrated in FIG. 5. FIG. 9 is a diagram for explaining an example of a usage pattern of the nonwoven fabric of the present invention, and is a developed plan view showing a state in which a pants-type disposable diaper is developed and extended. 10 is a cross-sectional view taken along the line II of FIG.

Hereinafter, the nonwoven fabric of this invention is demonstrated, referring FIGS. 1-4 based on the preferable embodiment.
The non-woven fabric 1 of the present embodiment (hereinafter also simply referred to as “non-woven fabric 1”) is a hydrophilic non-woven fabric comprising a fiber assembly 11 in which long fibers 2 are fixed by a heat fusion part 3 as shown in FIG. It is. In the nonwoven fabric 1, a part of the long fiber 2 is broken, and one end portion 20a is fixed by the heat-sealing portion 3 and the other end portion is a free end portion 20b, and is erected away from the fiber assembly 11. A fiber 20 (hereinafter also referred to as a fiber 20 having a free end 20b) is provided. The nonwoven fabric 1 will be described below with the longitudinal direction of the nonwoven fabric 1 as the Y direction and the width direction of the nonwoven fabric 1 as the X direction, as shown in FIG. In addition, regarding the nonwoven fabric 1, the MD direction along the fiber orientation direction corresponds to the longitudinal direction (Y direction) depending on the orientation direction of the constituent fibers, and the CD direction perpendicular to the MD direction corresponds to the width direction (X direction). In the description, the Y direction and the MD direction mean the same direction, and the X direction and the CD direction mean the same direction. In addition, the nonwoven fabric 1 includes a fiber 20 having a free end portion 20b standing from the fiber assembly 11, and a loop-like fiber 23 (fiber 20) standing up in a loop shape between the heat fusion portions 3 and 3 described later. , Fiber 23 is referred to as “raising fiber”) and fiber assembly 11 composed of non-raising fibers other than “raising fiber”. The fiber assembly 11 includes a fiber 20 having a free end 20b standing from the fiber assembly 11, and a loop-like fiber 23 standing in a loop between the heat-sealing portions 3 and 3 described later. Except for brushed fibers.

  If it explains in full detail about the nonwoven fabric 1 of this embodiment, the nonwoven fabric 1 is formed based on the hydrophilic nonwoven fabric 10 which fixed the web which consists of the long fiber 2 intermittently with the heat-fusion part 3. FIG. Hereinafter, this will be described as the original nonwoven fabric (raw material nonwoven fabric) 10. The raw material nonwoven fabric 10 is a nonwoven fabric before breaking a part of the long fibers 2. Here, the “long fiber” has a fiber length of 30 mm or more, and the raw nonwoven fabric 10 is preferably a so-called continuous long fiber having a fiber length of 150 mm or more because a nonwoven fabric 1 having high breaking strength can be obtained. . Examples of the raw material nonwoven fabric 10 include a spunbond nonwoven fabric, a laminated nonwoven fabric of a spunbond layer and a meltblown layer, a heat roll nonwoven fabric by a card method, and the like. Examples of the laminated nonwoven fabric include spunbond-spunbond laminated nonwoven fabric, spunbond-spunbond-spunbond laminated nonwoven fabric, spunbond-meltblown-spunbond laminated nonwoven fabric, spunbond-spunbond-meltblown-spunbond laminated nonwoven fabric, etc. Can be mentioned.

  The hydrophilic raw material nonwoven fabric 10 is obtained by performing a hydrophilization treatment by attaching a hydrophilizing agent to the surface of the constituent fiber of the non-woven fabric or kneading the hydrophilizing agent into the constituent fiber. That is, the hydrophilic raw material nonwoven fabric 10 is formed by hydrophilizing the hydrophobic long fibers 2.

Hydrophilic agents include anionic, cationic, amphoteric and nonionic surfactants such as carboxylate anionic surfactants, sulfonate anionic surfactants, and sulfate ester salts. Anionic surfactants such as phosphate anionic surfactants (especially alkyl phosphate salts); sorbitan fatty acid esters, diethylene glycol monostearate, diethylene glycol monooleate, glyceryl monostearate, Polyhydric alcohol monofatty acid esters such as glyceryl monooleate and propylene glycol monostearate, fatty acid amides such as oleic acid amide, stearic acid amide and erucic acid amide, N- (3-oleyloxy-2-hydroxypropyl) diethanolamine, polyoxy Ethylene hydrogenated castor oil, polyoxyethylene sorbit beeswax, polyoxyethylene sorbitan sesquistearate, polyoxyethylene monooleate, polyoxyethylene sorbitan sesquistearate, polyoxyethylene glyceryl monooleate, polyoxyethylene monostearate, poly Nonionic surfactants such as oxyethylene monolaurate, polyoxyethylene monooleate, polyoxyethylene cetyl ether, polyoxyethylene lauryl ether; cationic surfactants such as quaternary ammonium salts, amine salts or amines A zwitterionic surfactant such as an aliphatic derivative of a secondary or tertiary amine containing carboxy, sulfonate, sulfate, or an aliphatic derivative of a heterocyclic secondary or tertiary amine; It can be used. These preferable surfactants and preferable combinations of surfactants only need to contain these surfactants, and may further contain other surfactants and the like.
The amount of the hydrophilizing agent in the nonwoven fabric 1 is preferably 0.1% by weight or more and 20% by weight or less with respect to the weight of the nonwoven fabric 1 from the viewpoint of achieving both the liquid passing time and the liquid return amount. More preferably, it is at least 5% by weight.

In addition to the hydrophilizing agent, additives such as a fiber colorant, an antistatic property agent, and a softening agent may be added to the raw material nonwoven fabric 10. In particular, if a softening agent is kneaded or applied to the raw material nonwoven fabric 10, the effect of improving the touch when in contact with the skin is more effective. As the softening agent, for example, a wax emulsion, a reactive softening agent, a silicone compound, a surfactant and the like can be used. Moreover, a well-known chemical | medical agent can be added to a softening agent as a secondary additive (small component) as needed.
By including a softening agent, the nonwoven fabric 1 formed based on the nonwoven fabric 10 has a good touch, little fluff loss, low surface friction on the surface, and high breaking strength.
The softener is preferable in terms of increasing the effect when used in combination with a random copolymer, which will be described later, as a resin of the constituent fibers of the raw nonwoven fabric 10, and the slime feeling due to the random copolymer in the nonwoven fabric 1 formed from the raw nonwoven fabric 10. This is particularly preferable in that a softening agent can be used to reduce the occurrence of water and a smooth skin can be obtained.

  The raw nonwoven fabric 10 is formed of a laminated nonwoven fabric of a spunbond layer and a meltblown layer, and the spunbond layer of the laminated nonwoven fabric is composed of a plurality of layers. For example, a spunbond-meltblown-spunbond laminated nonwoven fabric In the case of a spunbond-spunbond-meltblown-spunbond laminated nonwoven fabric or the like, it is preferable to knead the softener only in one spunbond layer, knead in all spunbond layers, etc. Also good. When a softening agent is kneaded into a single layer of spunbond, if the layer is subjected to the processing described below, the non-woven fabric 1 having a good touch when touching the skin and having a high breaking strength can be obtained. preferable. As described above, the nonwoven fabric 1 is more suitable than the raw material nonwoven fabric 10 formed of the laminated nonwoven fabric of the spunbond layer and the meltblown layer, in terms of the feel when contacting the skin and the amount of wetback. It is preferable to form based on the raw material nonwoven fabric 10 which consists of a bond nonwoven fabric simple substance.

  The constituent fibers of the raw material nonwoven fabric 10 mainly contain a thermoplastic resin, and examples of the thermoplastic resin include polyolefin resins, polyester resins, polyamide resins, acrylonitrile resins, vinyl resins, and vinylidene resins. Examples of the polyolefin resin include polyethylene, polypropylene, and polybuden. Examples of the polyester resin include polyethylene terephthalate and polybutylene terephthalate. Nylon etc. are mentioned as a polyamide-type resin. Examples of the vinyl resin include polyvinyl chloride. Examples of the vinylidene resin include polyvinylidene chloride. One of these various resins can be used alone or in admixture of two or more, and modified products of these various resins can also be used. Moreover, a composite fiber can also be used as the long fibers constituting the raw material nonwoven fabric 10. Side-by-side fibers, core-sheath fibers, core-sheath fibers having eccentric crimps, split fibers, and the like can be used as the composite fibers. When using a composite fiber, it is preferable that a core-sheath fiber having a core made of polypropylene and a sheath made of polyethylene is used because a soft nonwoven fabric 1 can be obtained. The fiber diameter of the long fibers 2 is preferably 5 μm or more and 30 μm or less, and more preferably 10 μm or more and 20 μm or less before processing described later.

  The raw nonwoven fabric 10 is preferably formed from a polypropylene resin which is a polyolefin resin from the viewpoint of spinnability. The polypropylene resin is smooth, and from the viewpoint of improving the touch when it comes into contact with the skin, and from the viewpoint of easy breakage, at least 5% by mass of any one of random copolymer, homopolymer and block copolymer is 100 It is preferable that the resin contains not more than 25% by mass, more preferably not less than 25% by mass and not more than 80% by mass. Further, these copolymers and homopolymers may be mixed, or other resins may be mixed. However, it is difficult to break the yarn during molding, and mixing of polypropylene homopolymer and random copolymer is preferable. This reduces the fiber crystallinity and softens the raised fiber itself, improves the feel when it comes into contact with the skin, and is compatible with the nonwoven fabric breaking strength, and the raised fiber is embossed, etc. It becomes easy to be cut | disconnected by this melt | fusion part. Therefore, peeling at the heat fusion part 3 such as an embossing fusion point is eliminated, the raised fibers are shortened, hair balls are hardly formed, and a good appearance can be obtained. In addition, since the melting point distribution is widened, the sealing property is improved. Further, a copolymer copolymerized with ethylene or α-olefin as a random copolymer based on a propylene component is preferred, and an ethylene-propylene copolymer resin is particularly preferred. From the same viewpoint, the polypropylene resin is preferably a resin containing 5% by mass or more of an ethylene propylene copolymer resin, and more preferably a resin containing 25% by mass or more. The ethylene / propylene copolymer resin preferably contains an ethylene concentration of 1% by mass or more and 20% by mass or less, and particularly has no stickiness, is easy to stretch when stretched, has little fluff loss, and maintains the breaking strength. It is more preferable that the ethylene concentration is 3% or more and 8% or less. Moreover, as a polypropylene resin, it is preferable that it is resin containing 50 mass% or more of recycled polypropylene resins from an environmental viewpoint, and it is still more preferable that it is resin containing 70 mass% or more. The same applies when the nonwoven fabric 1 is formed based on a laminated nonwoven fabric of a spunbond layer and a meltblown layer.

The nonwoven fabric 1 formed from the raw material nonwoven fabric 10 is inexpensive and provides a good feel when touched to the skin, and has a basis weight of 5 g / m ² or more and 100 g / m from the viewpoint of processing suitability. It is preferably ² or less, and more preferably 5 g / m ² or more and 25 g / m ² or less.

In addition, the nonwoven fabric 1 configured as described above has a bulk softness of preferably 10 cN or less, more preferably 5.9 cN or less, and 0.5 cN or more from the viewpoint of excellent touch. Preferably there is.
In addition, the raw material nonwoven fabric 10 has a bulk softness of preferably 15 cN or less, more preferably 10 cN or less, and preferably 3 cN or more, from the viewpoint that a soft material is obtained and the touch is excellent. More preferably, it is 5 cN or more. Specifically, it is preferably 3 cN or more and 15 cN or less, and more preferably 5 cN or more and 10 cN or less.
Bulk softness is measured by the following measurement method.

[Measurement method of bulk softness]
The bulk softness of the nonwoven fabric 1 is obtained by cutting the nonwoven fabric 1 in the Y direction (longitudinal direction) 150 mm and the X direction (width direction) 30 mm in a 22 ° C. and 65% RH environment, and using a stapler in a ring shape with a diameter of 45 mm. Stop the edges at the top and bottom. At this time, the stapler core is elongated in the Y direction (longitudinal direction). Using a tensile tester (for example, Tensilon tensile tester “RTA-100” manufactured by Orientec Co., Ltd.), the ring is placed in a cylindrical shape on the sample stage, and the compression speed is 10 mm on a flat plate substantially parallel to the stage from above. Measure the maximum load when compressing at a rate of / min and make it bulk bulkiness.

  In the nonwoven fabric of the present invention, the fiber 20 having the free end 20b standing upright away from the fiber assembly 11 has a lower hydrophilicity than the fibers constituting the fiber assembly 11. ing. The smaller the value of the contact angle with water, the higher the hydrophilicity. In other words, the fiber 20 having the free end portion 20b is more hydrophobic than the fiber constituting the fiber assembly 11, and the contact angle with respect to pure water is the fiber 20 constituting the fiber assembly 11. It is higher than the fiber. Specifically, the contact angle with respect to the pure water of the fiber 20 having the free end 20b is preferably higher than 80 °, and more preferably higher than 85 °, from the viewpoint of making it difficult to reverse the body fluid once absorbed. 90 ° or more is particularly preferable. The contact angle of the fibers constituting the fiber assembly 11 with respect to pure water is preferably lower than 90 °, more preferably lower than 85 °, and more preferably 80 ° or less from the viewpoint of quickly transferring body fluid to the absorber side. Particularly preferred. The contact angle of the fiber 20 having the free end portion 20b is different from the contact angle of the fiber constituting the fiber assembly 11 by 5 ° or more from the viewpoint of achieving both liquid permeability and liquid return difficulty. It is preferably high, and more preferably a difference of 10 ° or more. Here, there is a difference in the contact angle value, that is, the difference in hydrophilicity means that the contact angle value measured by the measurement method has an opening of 3 ° or more.

  A specific method for measuring the contact angle is as follows. For the measurement of the contact angle, for example, a contact angle meter MCA-J manufactured by Kyowa Interface Science Co., Ltd. is used. Specifically, after ion-exchanged water is dropped on the nonwoven fabric 1 (about 20 picoliters), the contact angle is measured immediately using the contact angle meter. In particular, the contact angle of the fiber 20 having the free end portion 20b is measured at a portion where the fiber 20 having the free end portion 20b is cut, and the contact angle of the non-raised fiber constituting the fiber assembly 11 is determined in the nonwoven fabric 1. Then, the fiber 20 having the free end and the fiber 23 on the loop standing in a loop shape between the heat fusion parts 3 and 3 are removed, that is, the part of the fiber assembly 11 cut out is measured. Each measurement is performed at five or more locations, and the average value thereof is taken as the contact angle. The measurement is performed in an environment of 22 ° C. and 65% RH.

  The nonwoven fabric 1 is preferably 30% or more, in terms of the ratio of fibers having a fiber-to-fiber distance of 150 μm or more and 300 μm or less among the fibers constituting the nonwoven fabric 1, from the viewpoint of quickly transferring body fluid to the absorbent side. More preferably, it is more preferably 40% or more.

  The interfiber distance of the nonwoven fabric 1 is measured using a mercury porosimeter (Shimadzu Corporation) in accordance with a mercury intrusion method (JIS R 1655). The mercury intrusion method is a method for obtaining information on the physical shape of the fiber assembly 11 by measuring the size and the volume between the fibers constituting the fiber assembly 11 (interfiber distance). The principle of the mercury intrusion method is to apply pressure to mercury and inject it into the constituent fibers of the nonwoven fabric 1, which is the object to be measured, and measure the relationship between the pressure applied at that time and the volume of mercury that has been pushed in (intruded) It is in. Hereinafter, the measuring method of the interfiber distance of the nonwoven fabric 1 using a mercury porosimeter is demonstrated.

[Measurement method of distance between fibers of non-woven fabric 1]
First, the nonwoven fabric 1 is cut into 24 mm × 15 mm. A total of three sheets are cut, and these cut samples are set in a sample cell of a mercury porosimeter (Shimadzu Corporation) so as not to overlap each other, and the pore volume is measured. Specifically, the pore volume measurement method by mercury porosimetry is as follows. That is, the pressure applied to mercury is gradually changed, the volume of mercury pushed into the pores at that time, in other words, the pore volume is measured, and the pore diameter (interfiber distance) D converted according to the following equation (1): Draw the relationship between and the pore volume. The hole diameter (μm) at this time is defined as the interfiber distance (μm).

D = −4γ cos θ / P (1)

However, the hole diameter (distance between fibers) is D, the surface tension of mercury is γ, the contact angle is θ, and the pressure is P. As measurement conditions in the above formula (1), the surface tension of mercury is 482.536 dyn / cm, the contact angle is 130 °, and the mercury pressure is 0 to 60000 psia.
Based on the distribution curve (differential / integral curve) of the pore diameter (interfiber distance) of the obtained nonwoven fabric 1, the total pore diameter (interfiber distance) over which the pore diameter (interfiber distance) ranges from 0 μm to 500 μm is defined as the total capacity. The ratio of the capacity of the pore diameter (interfiber distance) of 150 μm or more and 300 μm or less to the total capacity is determined. The measurement is performed three times, and the average value thereof is set to a ratio (%) in which the interfiber distance is 150 μm or more and 300 μm or less. The measurement is performed in an environment of 22 ° C. and 65% RH.

  The nonwoven fabric 1 preferably has a breaking strength value of 5.0 N / 50 mm or more and 8.0 N / 50 mm or more and 30.0 N / 50 mm or less from the viewpoint of prevention of breakage during use and processing suitability. More preferably it is. The value of the breaking strength of the raw material nonwoven fabric 10 is preferably 7.0 N / 50 mm or more from the viewpoint of setting the breaking strength in the nonwoven fabric 1 to the above value, and is 10.0 N / 50 mm or more and 50.0 N / 50 mm or less. More preferably it is. According to the raising method described later, the value of the breaking strength of the produced nonwoven fabric 1 is less likely to be lower than the value of the breaking strength of the raw material nonwoven fabric 10 as compared with other raising methods. It is preferable that the breaking strength of the nonwoven fabric 1 and the original raw material nonwoven fabric 10 satisfy the above range in the CD direction. The ratio of the breaking strength between the nonwoven fabric 1 and the original raw material nonwoven fabric 10 (the breaking strength of the nonwoven fabric 1 / the breaking strength of the original raw material nonwoven fabric 10) is preferably 0.5 or more and 1.0 or less, 0.7 More preferably, it is 1.0 or less. The breaking strength is measured by the following method.

[Measurement method of breaking strength]
In a 22 ° C. and 65% RH environment, a rectangular measurement piece having a size of 200 mm in the CD direction and 50 mm in the MD direction is cut out from the nonwoven fabric 1 or the raw material nonwoven fabric 10 (for example, spunbond nonwoven fabric). The cut out rectangular measurement piece is used as a measurement sample. The measurement sample is attached to a chuck of a tensile tester (for example, Tensilon tensile tester “RTA-100” manufactured by Orientec Co., Ltd.) so that the CD direction is the tensile direction. The distance between chucks is 150 mm. The measurement sample is pulled at 300 mm / min, and the maximum load point until the sample breaks is defined as the breaking strength in the CD direction. Further, a rectangular measurement piece having a size of 200 mm in the MD direction and 50 mm in the CD direction is cut out and used as a measurement sample. The measurement sample is attached to a chuck of a tensile tester so that the MD direction is the tensile direction. The breaking strength in the MD direction is obtained by the same procedure as the method for measuring the breaking strength in the CD direction described above.

The non-woven fabric 1 is also characterized by a good touch (texture) when the surface provided with the fibers 20 having the free ends 20b comes into contact with the skin.
Conventionally, many characteristic values representing the touch are known, and in particular, the characteristic values in KES manufactured by Kato Tech Co., Ltd. are generally known (reference: texture evaluation standardization and analysis (second edition), author) Issued by Katsuo Kawabata, July 10, 1980). In particular, LC (linearity of compression load-compression strain curve), WC (compression work), and RC (compression resilience) of three characteristic values called compression characteristics are known to show a feeling of plumpness. These compressive characteristics have a load of 0.49 cN / cm ² (0.50 gf / cm ² ) or more and 49.0 cN / cm ² (50.0 gf / cm ² ) or less (0.49 cN / cm ² or more in high sensitivity measurement). .80cN / cm ² or less (0.50gf / cm ² or more 10.0gf / cm ² or less)) calculates the characteristic value from the amount of deformation when subjected. However, a very thin cloth such as a non-woven fabric having a small basis weight (5 g / m ² or more and 25 g / m ² or less) did not show a large difference, and the correlation with the touch was not large. Furthermore, the load when a human touches the absorbent article is about 0.98 cN / cm ² (1.00 gf / cm ² ), which is very light and feels the touch. The characteristic value in a small range is considered useful, and the load is between 0.29 cN / cm ² (0.3 gf / cm ² ) and 0.98 cN / cm ² (1 gf / cm ² ) and at that time A new characteristic value was found from the amount of deformation. This characteristic value is shown as a numerical value that clearly represents the difference in feel between the spunbonded nonwoven fabric and the air-through nonwoven fabric, and the nonwoven fabric can be expressed as a new characteristic value that represents the feel of the spunbonded nonwoven fabric.

[Compression characteristic value at minute load]
In this specification, the compression characteristic value at the time of a minute load is defined as a new characteristic value representing the touch. The measurement was performed in an environment of 22 ° C. and 65% RH. KES FB3-AUTO-A (trade name) manufactured by Kato Tech Co., Ltd. was used for measurement of data that is a basis for calculating the compression characteristic value at the time of a minute load. Three pieces of nonwoven fabric 1 are cut into 20 cm × 20 cm to prepare measurement samples. Next, one of the measurement samples is placed on the test stand with the raised surface (the surface provided with the fiber 20 having the free end 20b) facing upward (if not raised or both surfaces are raised) If so, measure both and use the smaller one). Next, compression is performed between steel plates having a circular plane with an area of 2 cm ² . The compression rate is 20 μm / sec, the maximum compression load is 9.80 cN / cm ² (10.0 gf / cm ² ), and the recovery process is also measured at the same rate. At this time, the amount of displacement between the steel plates is x (mm), the load is y (cN / cm ² ), and the position of the point where the load is detected is x = 0 and measured in the compression direction. The value of x increases as it is compressed.

The compression characteristic value at the minute load is calculated by extracting the deformation amount of the thickness at the minute load from the measured data (x, y). Specifically, the first load that is not a recovery process is a load between 0.29 cN / cm ² (0.30 gf / cm ² ) and 0.98 cN / cm ² (1.00 gf / cm ² ), and at that time The amount of deformation data is extracted, an approximate straight line is obtained for the relationship between x and y by the least square method, and the slope at that time is defined as the characteristic value (unit (cN / cm ² ) / mm). Three points are measured with one measurement sample. A total of 9 points of 3 samples are measured. The characteristic values at each of the nine locations are calculated, and the average value is set as the compression characteristic value when the nonwoven fabric is subjected to a minute load.

It has been found that the compression characteristic value at the time of a minute load has a correlation with the touch, and particularly has a strong correlation when the original raw material nonwoven fabric 10 is the same. The lower the value of the compression characteristic (at the time of a minute load), the easier it is to be crushed with a smaller load, and the better the feeling of feeling the human touch (particularly plumpness). For example, the compression characteristic value of the original raw material nonwoven fabric 10 (for example, spunbonded nonwoven fabric) having a normal basis weight of 5 g / m ² or more and 25 g / m ² or less, which is not subjected to the processing described later, is 19.6 (cN / cm ² ) / mm (20.0 (gf / cm ² ) / mm) to 29.4 (cN / cm ² ) / mm (30.0 (gf / cm ² ) / mm) The non-woven fabric 1 obtained by subjecting the original raw material nonwoven fabric 10 (for example, spunbonded nonwoven fabric) to the processing described below is easily crushed and the surface is less than 17.6 (cN / cm ² ) / mm (18.0 (gf / cm ² ) / mm) or less. That is, from the viewpoint of touch, the compression characteristic value of the nonwoven fabric 1 obtained by processing the original raw material nonwoven fabric 10 (for example, spunbond nonwoven fabric) of 5 g / m ² or more and 25 g / m ² or less is 17.6 (cN / cm ² ) / mm (18.0 (gf / cm ² ) / mm) or less and 14.7 (cN / cm ² ) / mm (15.0 (gf / cm ² ) / mm or less) are preferred, from the viewpoint becomes soft near fluffy air-through nonwoven ^{fabric, 9.80 (cN / cm 2)} / mm (10.0 (gf / cm 2) / mm) it is further preferred to be less. Although the lower limit of the compression characteristic value of the nonwoven fabric 1 obtained by processing the original raw material nonwoven fabric 10 (for example, spunbond nonwoven fabric) having a basis weight of 5 g / m ² or more and 25 g / m ² or less is not particularly limited, Is about 0.98 (cN / cm ² ) / mm (1.00 (gf / cm ² ) / mm). In conventional processing such as raising method, the raw material nonwoven fabric 10 (especially spunbonded nonwoven fabric) having a low basis weight of 5 g / m ² or more and 25 g / m ² or less is used in this way without significantly reducing the breaking strength. It has been difficult to perform processing so as to have various characteristic values.

In the heat-sealed portion 3 of the nonwoven fabric 1, the area of each heat-fused portion 3 is preferably 0.05 mm ² or more and 10 mm ² or less from the viewpoint of touch and processing suitability, and 0.1 mm ² or more and 1 mm ^2. More preferably, it is as follows. The number of heat-sealing portions 3 is preferably 10 / cm ² or more and 250 / cm ² or less, and more preferably 35 / cm ² or more and 65 / cm ² or less. The distance between the centers of the heat fusion parts 3 adjacent in the CD direction is preferably 0.5 mm or more and 10 mm or less, more preferably 1 mm or more and 3 mm or less, and the heat fusion part adjacent in the MD direction. The distance between the centers of the three is preferably 0.5 mm or more and 10 mm or less, and more preferably 1 mm or more and 3 mm or less.

  The heat fusion part 3 was intermittently formed by thermocompression bonding using embossing (with an embossed convex roller and a flat roll), ultrasonic fusion, or intermittent fusion by applying hot air intermittently. Things. Among these, the thermocompression bonding is preferable in that the fiber is easily broken. The shape of the heat sealing | fusion part 3 is not restrict | limited in particular, For example, arbitrary shapes, such as circular, a rhombus, and a triangle, may be sufficient. The ratio of the total area of the heat fusion part 3 to the surface area of one surface of the nonwoven fabric 1 is preferably 5% or more and 30% or less, and it is 10% or more and 20% or less because it is difficult to produce pills. Further preferred.

  The nonwoven fabric 1 is formed based on, for example, a spunbonded nonwoven fabric composed of long fibers 2, and a fiber 20 (a part of the fiber 2 is broken and only one end portion 20 a is fixed by the heat-sealed portion 3 ( A fiber 20) having a free end 20b is formed, and the fiber 20 includes a fiber 21 having a thick free end 20b (see FIG. 1). It is preferable that the tip is thick, and that the cross section at the tip is flat (ellipse or crushed shape). Thereby, the fiber which has raised the soft tip is obtained, and the nonwoven fabric with little irritation | stimulation to skin is obtained. As shown in FIG. 1, the fiber 20 in which only one end portion 20a is fixed by the heat-sealing portion 3 has a thick fiber 21 and free end portion 20b in which the free end portion 20b on the other end side is thick. It consists of fibers 22 that are not. Here, the “free end portion” means the “other end portion” of the fiber 20 in which only one end portion 20 a is fixed by the heat fusion portion 3, in other words, the “tip portion”. Whether or not the free end portion 20b is thick is determined by measuring the fiber diameter by the following measurement method and calculating the increasing rate of the tip fiber diameter.

[Measurement method of fiber diameter]
First, in a 22 ° C. and 65% RH environment, as shown in FIG. 3A, a measurement piece having a size of 2 cm in the CD direction and 2 cm in the MD direction is cut out from the nonwoven fabric 1 to be measured with a sharp razor. Then, as shown in FIG. 3 (b), a measurement sample obtained by mountain-folding at a fold line Z extending in the CD direction passing through the plurality of heat-sealing portions 3 is used as shown in FIG. 3 (c). Is mounted on an aluminum sample stage for a scanning electron microscope (SEM). Next, from the SEM image magnified approximately 750 times, ten fibers 20 in which only one end portion 20a is fixed by the heat fusion portion 3 are selected at random, and a photograph is taken near the tip of the free end portion of these fibers. To do. From the obtained photograph (see FIG. 2), the fiber diameter of the fiber 20 at a position 120 μm away from the tip of the free end 20b (the diameter 21a of the fiber 20 at a portion excluding the free end 20b) is measured. The inclination at the time of measurement of the diameter 21a of the fiber 20 in a portion excluding the free end 20b is translated as it is toward the free end 20b, and is sandwiched between the tip of the free end 20b and a position 20 μm away from the tip. The fiber diameter of the fiber 21 (the diameter 21b of the fiber 21 at the free end 20b) at the thickest position in the region is measured. When the tip is flat, the tip may not appear thick depending on the observation angle, but even in that case, the obtained photograph is measured as it is.

The fiber 21 in which the free end portion 20b is thick is the fiber 21 at the free end portion 20b measured from the photographs of the ten fibers 20 among the ten fibers 20 selected at random. From the diameter 21b and the diameter 21a of the fiber 20 at a portion excluding the free end 20b, the fiber satisfies the requirement that the value of the increase rate of the tip fiber diameter obtained by the following formula (2) is 15% or more. This means that the fiber cutting between the heat-bonding parts 3 (the fiber form part excluding the boundary between the heat-bonding part 3 and the fiber) is suppressed, the decrease in breaking strength is suppressed, and the touch From the viewpoint of obtaining a good product, it is preferably 20% or more, more preferably 25% or more.

Increase rate of tip fiber diameter (%) = [(21b-21a) ÷ 21a) × 100] (2)

  In the nonwoven fabric 1, the fiber 20 (only the one end part 20b is fixed by the heat sealing | fusion part 3 from the viewpoint of coexistence of the touch at the time of contact | abutting with skin and a fracture strength, and the viewpoint of cushioning improvement (free end part 20b). The ratio of the fibers 21 having the thick free ends 20b in the thick fibers 21 and the fibers 22) in which the free ends 20b are not thick is preferably 20% or more, more preferably 30% or more. Is more preferable, and 40% or more is particularly preferable. The ratio of the fibers 21 in which the free end portion 20b is thick is determined from the SEM image obtained by enlarging the randomly selected ten fibers 20 by about 750 times in the fiber diameter measurement method described above. Each is calculated, and the ratio of the fibers 21 whose free ends 20b are thick is calculated.

  As shown in FIG. 1, the nonwoven fabric 1 has loop-like fibers 23 erected in a loop shape between the heat-sealing portions 3 and 3. The standing “loop-like fiber 23” means that when the fiber diameter measurement method described above is observed as shown in FIG. 3C, the other end portion does not have the free end portion 20b and the folded line It means a fiber standing up from Z by 0.5 mm or more. In this specification, the loop-like fiber 23 refers to the standing loop-like fiber. As shown in FIG. 1, the fiber constituting the nonwoven fabric 1 is composed of a fiber 21 having a thick free end 20b and a fiber 22 having a thick free end 20b, and only one end 20a is a heat-sealed portion. 3, a fiber 20 (fiber 20 having a free end 20 b) fixed by 3, and a loop-like fiber 23 that stands up in a loop shape between the heat fusion parts 3, 3 in addition to the fiber 20. And fibers that are not raised. The fiber assembly 11 is mainly formed of the fibers that are not raised. The average fiber diameter of the constituent fibers of the fiber assembly 11 is selected and cut out at random from 10 fibers that are not raised, and the average value is determined in the same manner based on the above-described [Fiber Diameter Measurement Method].

  The nonwoven fabric 1 does not get caught on the skin when it comes into contact with the skin. From the viewpoint of reducing discomfort and improving the touch, only the one end portion 20a of the fibers constituting the nonwoven fabric 1 is formed by the heat fusion portion 3. The ratio of the loop-like fibers 23 to the total number of the fixed fibers 20 (fibers 20 having the free ends 20b) and the loop-like fibers 23 is preferably less than 50%, and 45% or less. More preferably, it is particularly preferably 40% or less. The ratio of the loop-like fibers 23 is determined by randomly selecting 10 fibers from the SEM image enlarged approximately 50 times in the above-described fiber diameter measurement method, and from the 10 fibers randomly selected, the free end portion 20b. Fiber 20 (fiber 21 having a thick free end 20b, fiber 22 having a free free end 20b) and loop-like fiber 23 are extracted, and the total number of fibers 21, 22 and 23 The ratio of the fibers 23 (loop-like fibers) is calculated and obtained. In addition, a measured value calculates | requires a ratio similarly from 9 SEM images of another site | part, and calculates it by those 10-point average. In addition, when one loop-like fiber 23 is included in ten randomly selected fibers, the loop-like fiber 23 is counted as one.

  In the nonwoven fabric 1, from the viewpoint of including a fiber having a relatively high degree of freedom, the gap between the fibers is filled, the surface roughness is small and smooth, and the touch when touching the skin is improved. The fiber diameter distribution (dispersion degree) is preferably as wide as possible, but from the viewpoint of the touch, a satisfactory effect can be obtained if it is 0.33 or more, and it is more satisfactory if it is 0.35 or more. The effect to be obtained is obtained. The fiber diameter distribution (dispersion degree) is not particularly limited, but is preferably 100 or less. More preferably, the fiber diameter distribution (dispersion degree) is preferably 0.35 or more and 0.9 or less. The fiber diameter distribution (dispersion degree) here means the fiber diameter distribution (dispersion degree) of all the fibers constituting the nonwoven fabric 1, and only one end portion 20 a is fixed by the heat-sealing portion 3. The fiber 20, the loop-shaped fiber 23, and both ends thereof are fixed by the heat-sealing portion 3, and the entire distribution of fibers that are not raised in a loop shape (fibers that are not affected by processing described later). The fiber diameter distribution (dispersion degree) is measured by the following method.

[Measurement of fiber diameter distribution (dispersion degree)]
First, in a 22 ° C. and 65% RH environment, a scanning type electronic device in which a measuring piece having a size of 2 cm in the CD direction and 2 cm in the MD direction was cut out from the nonwoven fabric 1 to be measured and mounted with a carbon tape. The sample is placed on an aluminum sample stage for a microscope (SEM) without being bent and fixed. Next, 10 fibers are randomly extracted from the SEM image magnified approximately 750 times, and each fiber diameter is measured at a portion excluding the free end 20b (note that the nonwoven fabric 1 to be measured is a spunbond layer). When the fiber is formed on the basis of a laminated non-woven fabric comprising a meltblown layer, the fiber of the meltblown layer is not selected, and only the fiber of the spunbond layer is selected. Ten fiber diameters are measured on one aluminum sample stage as described above, the average value d _ave is determined from the measured _ten fiber diameters d ₁ to d 10, and the obtained ten fiber diameters are obtained. From the d _{1 to} d ₁₀ and the average value d _ave , the fiber diameter distribution of 10 randomly selected fibers is obtained by the following equation (3). The measurement unit is μm, and measurement is performed with a resolution of 0.1 μm. The distribution of the fiber diameters of 10 fibers is made for the above-mentioned aluminum sample stage for each nonwoven fabric 1 and the average value of the distributions of the fiber diameters of the 10 fibers obtained at each position (the following formula) (See (4)) is the fiber diameter distribution in the nonwoven fabric 1. In addition, the VARPA function in spreadsheet software excel2003 of Microsoft Corporation is used for calculation of the fiber diameter distribution of 10 fibers.

Fiber diameter distribution of 10 fibers = [(d ₁ −d _ave ) ² + (d ₂ −d _ave ) ² +... (D ₁₀ −d _ave ) ² )] / 10 (3)

Fiber diameter distribution (dispersion degree) in the nonwoven fabric 1 = (total sum of fiber diameter distributions of 10 fibers obtained by the above formula (3)) / 6 (4)

  The nonwoven fabric 1 is preferably 8 fibers / cm or more, more preferably 12 fibers / cm or more from the viewpoint of improving cushioning properties and improving the touch when in contact with the skin. It is more preferable. Here, the raised fibers in the nonwoven fabric 1 are fibers 20 having free ends 20b (fibers 21 having free ends 20b are thick, fibers 22 having free ends 20b are not thick), And the loop-like fiber 23 is included. The upper limit of the raised fibers is 100 fibers / cm or less from the viewpoint of obtaining sufficient breaking strength, and more preferably 40 fibers / cm or less from the point of appearance that they are not fluffy. The raised fibers are measured by the following measurement method. In the present application, the “nonwoven fabric provided with raised fibers” refers to a nonwoven fabric in which the number of raised fibers is 5 / cm or more in the following measurement method.

[Method of measuring the number of raised fibers]
FIG. 4 is a schematic view showing a method for measuring the number of fibers raised among the fibers constituting the nonwoven fabric 1 in an environment of 22 ° C. and 65% RH. First, a measurement piece of 20 cm × 20 cm is cut out from the nonwoven fabric to be measured with a sharp razor, and as shown in FIG. 4A, the measurement sample 104 is formed by mountain folding on the raised surface of the measurement piece. Next, this measurement sample 104 is placed on an A4 size black mount, and as shown in FIG. 4B, an A4 size black mount in which holes 107 of 1 cm in length and 1 cm in width are further formed. Put on. At this time, as shown in FIG. 4B, the fold 105 of the measurement sample 104 is arranged so that it can be seen from the hole 107 of the upper black mount. For both mounts, “Kenran (black) continuous weight 265 g” of Fuji Kyowa Paper Co., Ltd. was used. Thereafter, a weight of 50 g is placed on each side of the upper mount hole 107 at a position spaced 5 cm outward along the fold line 105 so that the measurement sample 104 is completely folded. Next, as shown in FIG. 4C, the inside of the hole 107 of the mount is observed at a magnification of 30 using a microscope (VHX-900 manufactured by KEYENCE), and the measurement sample 104 has a fold 105 to 0. Measure the number of fibers per 1 cm above the imaginary line 108 formed at the position translated by 2 mm above. Nine points are measured, and the average value (rounded to the second decimal place) is taken as the number of raised fibers.

  Further, when counting the number of raised fibers, for example, there is a fiber that crosses the virtual line 108 that is 0.2 mm above the fold 105 twice, such as a fiber 106a shown in FIG. The fiber counts as two. Specifically, in the example shown in FIG. 4C, there are four fibers crossing the virtual line 108 once and one fiber 106a crossing the virtual line 108 twice, but two fibers 106a crossing the virtual line 108 twice. Counted as a book, the number of raised fibers is 6.

  The nonwoven fabric 1 is a fiber that is raised (a fiber that crosses the imaginary line 108 and includes a fiber 20 having a free end 20b and a loop-like fiber 23 from the viewpoint of improving the touch when touching the skin. ) Of the surface fibers of the same surface that are not brushed (fibers that do not cross the imaginary line 108 and do not reach the imaginary line 108, that is, fibers that are not brushed that constitute the fiber assembly 11). It is preferably smaller than the average fiber diameter. The average fiber diameter refers to a fiber diameter obtained by measuring the fiber diameters of 12 raised fibers and 12 non-raised fibers with a microscope (such as an optical microscope or SEM). The average fiber diameter of the raised fibers is preferably 98% or less and 40% or more of the average fiber diameter of the non-raised fibers, and more preferably 96% or less and 70% or more because it is excellent in the touch. Similarly, the average fiber diameter of the fibers 20 having the free end portion 20b and the average fiber diameter of the loop-shaped fibers 23 are both larger than the average fiber diameter of the fibers constituting the fiber assembly 11 (fibers not raised). It is preferably small, and preferably 98% or less and 40% or more of the fiber diameter of the non-raised fiber, more preferably 96% or less and 70% or more, because it is excellent in the touch.

  In addition, as described above, the nonwoven fabric 1 has a number of raised fibers (fibers including free ends 20b and fibers including loop-like fibers 23) of 8 / cm or more and is raised. It is preferable that the raised height of the fibers is 1.5 mm or less. Thereby, cushioning property improves and the absorbent article which the touch improved is obtained. From the viewpoint of being less prone to fluff and difficult to remove, it is more preferable that the raised height of the raised fiber is 1.0 mm or less. On the other hand, if it is 0.2 mm or more, a good touch can be obtained. Furthermore, the raised height is preferably 0.5 mm or more in that the amount of wetback in the absorption characteristics of body fluid is reduced. When a raised surface is used on the surface side that comes into contact with the skin, the raised height is more preferably 1.0 mm or less from the viewpoint that it is difficult to cling to the skin and feel is preferable. Moreover, it is good at the point that the thing of the improvement of cushioning property and a quick absorption speed of a bodily fluid is obtained that the fiber which has fluffed is 15 pieces / cm or more. Further, if the height of the raised fiber exceeds 5 mm, it becomes a fuzzy appearance, and if it is rubbed during use, it becomes fuzzy or fluffy, which is not preferable. Here, the raised height means the height of the fiber in the natural state without pulling the fiber during measurement, unlike the length of the fiber. When the value of the length of the raised fiber is large or the rigidity of the fiber is high, the raised height of the raised fiber tends to increase. The raised height of the raised fiber is measured by the following measuring method.

[Measurement method of raising height of raising fiber]
The raising height of the raised fibers is measured at the same time as measuring the number of raised fibers (fibers having free ends 20b and fibers including loop-like fibers 23). Specifically, as shown in FIG. 4C, the inside of the hole 107 of the mount is observed, and a line is drawn in parallel from the crease 105 to a point where fibers that are raised every 0.05 mm do not intersect. Next, compared to the number of raised fibers measured as described above (determined from the imaginary line 108 above 0.2 mm), select a parallel line that halves the fibers that intersect the parallel line, and from there The distance to the crease is the raised height. The above-mentioned operation is measured for three sheets of the nonwoven fabric to be measured, and the average of three places per sheet and three places in total is taken as the raised height of the raised fibers.

  In addition to the raised height of the raised fibers and the number of raised fibers, the bulk softness of the non-woven fabric 1 is 8.0 cN or less, so that a flexible material can be obtained when it comes into contact with the skin. It is preferable at the point which is excellent in the touch. Furthermore, it is preferable that it is 0.5 cN or more and 3.0 cN or less from the point which becomes a supple thing like a baby's or infant's vestibule. Bulk softness is measured by the following measurement method.

[Measurement method of bulk softness]
The bulk softness of the nonwoven fabric 1 is 150 mm in the MD direction and 30 mm in the CD direction, and is stapled into a ring shape with a diameter of 45 mm at two upper and lower ends. At this time, the stapler core is elongated in the MD direction. Using a tensile tester (for example, Tensilon tensile tester “RTA-100” manufactured by Orientec Co., Ltd.), the ring is placed in a cylindrical shape on the sample stage, and the compression speed is 10 mm on a flat plate substantially parallel to the stage from above. Measure the maximum load when compressing at a speed of / min. Next, a ring is produced by changing the MD direction and the CD direction, and the bulk softness in the MD direction is similarly measured. Two rings each in the MD direction and the CD direction are prepared and measured, and the average value of the CD direction and the MD direction is defined as the bulk degree of the nonwoven fabric 1.

  Next, the manufacturing method of the nonwoven fabric 1 is demonstrated. The suitable manufacturing method of the nonwoven fabric 1 is demonstrated referring FIGS. As shown in FIG. 5, the manufacturing apparatus preferably used in the method for manufacturing the nonwoven fabric 12 is roughly divided into a pre-processing section 4 and a raised processing section 5 disposed on the downstream side of the pre-processing section 4. This pre-processed portion is also referred to as a partially stretched processed portion.

  As shown in FIGS. 5 and 6, the pre-processing unit 4 includes a steel matching embossing roller 43 including a pair of rollers 41 and 42. As shown in FIG. 6, the steel matching embossing roller 43 has a cylindrical shape made of metal such as aluminum alloy or steel, and one roller 41 has a plurality of convex portions 411 on its peripheral surface, The roller 42 has a concave portion 422 into which the convex portion 411 enters at a position corresponding to the convex portion 411 of the one roller 41 on the peripheral surface. In addition, as shown in FIG. 6, the other roller 42 has a plurality of convex portions 421 on the peripheral surface, and one roller 41 protrudes at a position corresponding to the convex portion 421 of the other roller 42 on the peripheral surface. It has a recess 412 into which the part 421 enters. As shown in FIG. 6, the pair of concave and convex rollers 41 and 42 has convex portions 411 and 421 and concave portions 412 and 422 arranged in a staggered manner on the respective peripheral surfaces. The pair of rollers 41 and 42 mesh with each other and rotate when a driving force from a driving means (not shown) is transmitted to at least one rotating shaft. In the manufacturing apparatus of the present embodiment, the one uneven roller 41 and the other uneven roller 42 are the same except that the convex portions 411 and 421 are provided at positions corresponding to the concave portions 422 and 412. Same roller. Therefore, in the following description, the convex portion 411 of the one concave / convex roller 41 will be mainly described for similar portions. Moreover, the pre-processing part 4 is equipped with the conveyance rollers 44 and 45 used when conveying the raw material nonwoven fabric 10 in the upstream and downstream of the steel matching embossing roller 43, as shown, for example in FIG.5 and FIG.6. . The rotation speed of the steel matching embossing roller 43 is controlled by a control unit (not shown) provided in the manufacturing apparatus.

As shown in FIG. 7, each of the convex portions 411 of the roller 41 preferably has a height h from the circumferential surface of the roller 41 to the top of the convex portion 411 of 1 mm or more and 10 mm or less, and 2 mm or more and 7 mm or less. More preferably. The distance (pitch) between the protrusions 411 adjacent in the rotation axis direction is preferably 0.01 mm or more and 20 mm or less, more preferably 1 mm or more and 10 mm or less, and the distance between the protrusions 411 adjacent in the circumferential direction. The distance (pitch) P ₁ is preferably 0.01 mm or more and 20 mm or less, and more preferably 1 mm or more and 10 mm or less. There is no particular limitation on the shape of the top surface of each convex section 411 of the roller 41, for example, circular, polygonal, elliptical or the like is used, the area of the top surface of each convex section 411, 0.01 mm ² or more 500 mm ² Or less, more preferably 0.1 mm ² or more and 10 mm ² or less. Each concave portion 422 of the roller 42 is disposed at a position corresponding to each convex portion 411 of the roller 41. The depth D of engagement between the convex portions 411 of the roller 41 and the convex portions 421 of the roller 42 (the length of the portion where the convex portions 411 and the convex portions 421 overlap) (see FIG. 7) is 3 0.5 mm or more, preferably 3.7 mm or more, more preferably 4 mm or more, and 5 mm or less, preferably 4.8 mm or less, further 4.5 mm or less. Specifically, it is 3.5 mm or more and 5 mm or less, preferably 3.7 mm or more and 4.8 mm or less, more preferably 4 mm or more and 4.5 mm or less.

  As shown in FIG. 8, the raised portion 5 includes a convex roller 51 having a convex portion 511 provided on the peripheral surface, and conveys the pre-processed nonwoven fabric 10 ′ to the upstream side and the downstream side of the convex roller 51. Conveying rollers 52 and 53 are provided. The convex roller 51 rotates when a driving force from a driving means (not shown) is transmitted to its rotating shaft.

Each convex portion 511 of the convex roller 51 has a height from the peripheral surface of the convex roller 51 to the apex of the convex portion 511 of preferably 0.001 mm or more and 3 mm or less, and 0.001 mm or more and 0.1 mm or less. More preferably. Since the convex roller 51 includes such a minute height, the convex roller 51 includes a so-called sand blast roller. The distance (pitch) between the protrusions 511 adjacent to each other in the rotation axis direction is preferably 0.1 mm or more and 50 mm or less, more preferably 0.1 mm or more and 3 mm or less, and the protrusions 511 adjacent in the circumferential direction. The distance (pitch) between them is preferably from 0.1 mm to 50 mm, and more preferably from 0.1 mm to 3 mm. The shape of the top surface of each convex portion 511 of the convex roller 51 is not particularly limited, and for example, a circle, a polygon, an ellipse or the like is used, and the area of the top surface of each convex portion 511 is 0.001 mm ² or more and 20 mm. preferably ² or less, still more preferably 0.01 mm ² or more 1 mm ² or less. When the convex roller 51 is a sand blast roller, the density of the convex portions 511 is preferably 1000 / cm ² or more and 3000 / cm ² or less, and preferably 1200 / cm ² or more and 2500 / cm ^2. More preferably, it is as follows.

  In a manufacturing apparatus provided with the pre-processing part 4 and the raising part 5 of such a structure, first, the raw material of the nonwoven fabric 1, for example, the hydrophilic raw material nonwoven fabric 10 subjected to the hydrophilization treatment is unwound from the roll. Then, the hydrophilic raw material nonwoven fabric 10 is supplied between the pair of concave and convex rollers 41 and 42 of the steel matching embossing roller 43 by the conveying rollers 44 and 45, and partially stretched at each of a plurality of locations of the raw material nonwoven fabric 10. Specifically, in the pre-processed portion 4, as shown in FIG. 5, the raw material nonwoven fabric 10 is sandwiched between a pair of rollers 41 and 42 to damage the raw material nonwoven fabric 10. From the viewpoint of not causing heat fusion between the constituent fibers of the nonwoven fabric when giving damage, the pair of rollers 41 and 42 of the steel matching embossing roller 43 is not actively heated, or the fibers constituting the raw material nonwoven fabric 10 The steel match embossing is preferably performed at a temperature equal to or lower than the melting point of the component having the lowest melting point among these components, particularly at a temperature lower by 70 ° C. or more than the melting point.

  Next, as shown in FIG. 5, the raw material nonwoven fabric 10 ′ subjected to the partial stretching process is supplied to the convex roller 51 provided with the convex portion 511 on the peripheral surface by the conveying rollers 52 and 53. In the raising process part 5, it supplies to a convex roller, and it extends | stretches, breaking up some long fibers 2 of raw material nonwoven fabric 10 ', and raises upwards rather than the fiber assembly 11, and comprises the fiber assembly 11. A fiber 20 having a free end 20b that is stretched more than the fiber is formed, and a nonwoven fabric 1 is formed in which the hydrophilicity of the fiber 20 having the free end 20b is lower than the hydrophilicity of the fibers constituting the fiber assembly 11. To do. Specifically, the surface of the raw material nonwoven fabric 10 ′ subjected to the partial stretching process is processed by the convex roller 51, a part of the long fiber 2 is broken, and only the one end portion 20 a is formed by the heat fusion portion 3 of the nonwoven fabric. A fixed fiber 20 is formed. When the fiber 20 is formed, the fiber 20 having the free end 20b is stretched more than the fibers constituting the fiber assembly 11 of the base portion that is not raised. By stretching in this way, the hydrophilicity of the fiber 20 having the free end portion 20b is lower than the hydrophilicity of the fiber constituting the fiber assembly 11. From the viewpoint of efficiently forming the fiber 20 shown in FIG. 1, it is preferable to rotate the rotation direction of the convex roller 51 in the opposite direction to the conveyance direction of the raw material nonwoven fabric 10 ′. The convex roller 51 is preferably rotated at a speed of 0.3 to 10 times. When rotating in the circumferential direction (forward direction with respect to the transport direction), it is preferable to rotate the convex roller 51 at a speed of 1.5 times or more and 20 times or less. Here, the speed of the convex roller 51 means the peripheral speed on the peripheral surface of the convex roller 51.

  From the viewpoint of breaking a part of the long fiber 2 more efficiently and forming the fiber 20 shown in FIG. 1 more efficiently, the position of the conveying roller 53 is set higher than the convex roller 51 as shown in FIG. Is preferably in contact with the contact surface of the convex roller 51 at a holding angle α of 10 ° or more and 180 ° or less, and at a holding angle α of 30 ° or more and 120 ° or less. It is more preferable that the width reduction due to neck-in of the nonwoven fabric 1 is suppressed.

  In addition, when forming the fiber 20 which has the free end part 20b on both surfaces of the nonwoven fabric 1, the surface (back surface) different from the surface of the raw material nonwoven fabric 10 'processed with the convex roller 51 is further provided with another convex roller 51. Can be obtained by processing.

  The fiber 21 having a thick free end 20b is partially stretched by the steel matching embossing roller 43 so that the raw nonwoven fabric 10 is partially stretched to form a weakening point in the heat-sealed portion 3 of the raw nonwoven fabric 10, and then the convex roller 51. Thus, the long fiber 2 is broken and formed from the weakening point of the very surface portion of the raw material nonwoven fabric 10 ′ of the heat fusion part 3. Further, when the surface of the fiber 22 which is not thick at the free end portion 20 b is processed by the convex roller 51, the long fiber 2 is broken between the heat fusion portions 3 and 3. Moreover, the long fiber 2 peels from the weakening point of the heat-fusion part 3 by the convex roller 51, and the fiber peeled from the heat-fusion part 3 is looped between the heat-fusion parts 3 and 3. What stands is a loop-like fiber 23. The nonwoven fabric manufactured by the suitable manufacturing method of the nonwoven fabric 1 mentioned above is characterized in that the proportion of the loop-like fibers 23 and the fibers 22 that are not thick is smaller than the nonwoven fabric manufactured by the conventional raising method. . Since the nonwoven fabric manufactured with the suitable manufacturing method of the nonwoven fabric 1 mentioned above has few ratios of the fiber 22 which is not thick, it can hold | maintain breaking strength.

  The reason why the hydrophilicity of the fiber 20 having the free end portion 20b is lower than the hydrophilicity of the fiber constituting the fiber assembly 11 is that the hydrophilic raw material nonwoven fabric 10 is stretched by the pre-processing portion 4 and the raised processing portion 5. This is because the fiber 20 is stretched more than the fibers constituting the fiber assembly 11. As described above, the hydrophilic raw material nonwoven fabric 10 formed by hydrophilizing the amount of the hydrophilizing agent in the range of 0.1% by weight to 20% by weight with respect to the weight of the nonwoven fabric 1 is pre-processed. From the viewpoint of changing the hydrophilicity by the portion 4 and the raised portion 5, the draw ratio of the fiber represented by the following formula (8) is preferably 3% or more and 100% or less, and preferably 5% or more and 50%. More preferably, it is as follows. The draw ratio of the fiber is determined as follows.

[Measurement method of draw ratio of fiber]
The fiber draw ratio is calculated from the fiber diameter of the non-woven fabric 1 before processing (equal to the fiber diameter of the fibers constituting the fiber assembly 11) and the fiber diameter of the fibers 20 having the free end 20b after processing. The deformation due to fiber drawing is assumed to be plastic deformation, and the volume before and after processing is assumed to be constant. When the fiber diameter before processing is D μm, the fiber length before processing is A mm, the fiber diameter after processing is D ′ μm, and the fiber length after processing is A ′ mm, the following equation (5) is established.

(Π / 4) × D ² × A = (π / 4) × (D ′) ² × A ′ (5)

The draw ratio after processing can be expressed by the following formula (6) from the fiber length before and after processing.

Fiber draw ratio (%) = [{(A ′ / A) −1} × 100] (6)

From the above formula (5), the fiber lengths A and A ′ can be expressed by the following formula (7) using the fiber diameters D and D ′. From the formulas (5) and (7), the fiber draw ratio Can be expressed as the following formula (8).

A ′ / A = (D / D ′) ² (7)

Fiber draw ratio (%) = [{(D ′ / D) ² −1} × 100] (8)

The effect at the time of using the nonwoven fabric 1 of embodiment of this invention mentioned above is demonstrated.
As shown in FIGS. 1 and 2, the nonwoven fabric 1 of the present embodiment has a part of the long fibers 2 broken, only one end portion 20 a is fixed by the heat fusion portion 3, and the free end portion at the other end portion. 20b, which has the fibers 20 standing away from the fiber assembly 11 of the base portion. Therefore, there is a feeling of plumpness as a whole, cushioning properties are improved, and touch is improved. Moreover, since the nonwoven fabric 1 is formed from the hydrophilic raw material nonwoven fabric 10, since it is hydrophilic and a part of the surface long fiber 2 is fractured | ruptured, the liquid permeability of a liquid improves. And since the hydrophilicity of the fiber 20 which has the free end part 20b is lower than the hydrophilicity of the fiber which comprises the fiber assembly 11, fiber assembly from the surface of the fiber assembly 11 with the fiber 20 which has the free end part 20b The liquid that has passed through the body 11 is unlikely to return from the fiber assembly 11 to the surface of the fiber assembly 11. Thus, the nonwoven fabric 1 is a nonwoven fabric that has good cushioning properties, good body fluid permeability, and is difficult to reverse the liquid.

  The above effect is further achieved if the contact angle of the fiber 20 having the free end 20b with respect to pure water is higher than 80 °, and the nonwoven fabric 1 has a fiber-to-fiber distance of 150 μm or more among the fibers constituting the nonwoven fabric 1. If the proportion of fibers of 300 μm or less is 40% or more, the effect is further enhanced. Moreover, if the fiber 20 having the free end portion 20b includes the fiber 21 in which the free end portion 20b is thick, the overall plump feeling is further improved, and the touch is further improved.

  The range of use of the nonwoven fabric 1 is suitably used mainly for constituent members in absorbent articles such as disposable diapers and sanitary napkins. Examples of the constituent member include a surface sheet, a back sheet, a sheet constituting an outer packaging material of the disposable diaper, and the nonwoven fabric 1 is particularly suitable for a surface sheet of an absorbent article used for a wearer's skin contact surface. Used for. The use range of the nonwoven fabric 1 is also suitably used for a cleaning sheet. Hereinafter, the disposable diaper using the nonwoven fabric 1 will be described as an example.

As shown in FIGS. 9 and 10, the pants-type disposable diaper 100 is positioned on the non-skin contact surface side of the absorbent main body 50 including the absorbent body 40 and fixes the absorbent main body 50. The outer packaging material 60 is provided.
As shown in FIG. 10, the absorbent main body 50 includes a liquid-permeable top sheet 70, a liquid-impermeable (including water-repellent) back sheet 80, and a liquid-retaining property interposed between both sheets 70 and 80. It has the absorber 40 and is substantially long as shown in FIG.
As shown in FIG. 9, the outer packaging material 60 includes a back side portion A disposed on the back side of the wearer, an abdominal side portion B disposed on the abdomen side, and an inseam located between the crotch portions. It has a portion C, and both side edge portions 6a and 6b of the back side portion A and the ventral side portion B are joined to each other to form a pair of side seal portions (not shown) and a pair of leg openings (not shown). And a waist opening (not shown). Further, the outer packaging material 60 includes an outer layer sheet 62 that forms the outer surface of the diaper, and an inner layer sheet 61 that is located on the skin contact surface side and is partially joined to the outer layer sheet 62. The waist elastic member 63 and the leg elastic member 64 for gathering are disposed between the sheets 61 and 62 in the waist and leg 6d that form the leg opening.

As shown in FIG. 9, the absorbent main body 50 is disposed across the back side portion A and the abdominal side portion B of the outer packaging material 60, and both end portions in the longitudinal direction of the absorbent main body 50 are disposed on the outer packaging material 60. It is in the position retreated inward in the longitudinal direction from both ends in the longitudinal direction. As shown in FIG. 10, in the absorbent main body 50, the non-skin contact surface of the back sheet 80 of the absorbent main body 50 is an inner layer sheet 61 of the outer packaging material 60 by a bonding method using an adhesive, heat seal, ultrasonic seal or the like. It is joined to the skin contact surface.
As shown in FIG. 10, side cuffs 55, 55 made of a liquid-impermeable or water-repellent and breathable material are provided on both sides along the longitudinal direction of the absorbent main body 50. In the vicinity of the free end of each side cuff 55, an elastic member 56 for forming the side cuff is disposed and fixed in an extended state. The side cuff 55 can stand on the free end side when the diaper is worn, and can prevent excrement from flowing out in the width direction of the absorbent main body 50. As shown in FIG. 10, the side cuff 55 forming sheet has a portion 55 a having a predetermined width on the outer side in the width direction of the absorbent main body 50 wound around the non-skin contact surface side of the absorbent body 40. 40 and the back sheet 80 are fixed. Note that the portion 55 a having a predetermined width may be fixed between the back sheet 30 and the outer packaging material 60.

  The nonwoven fabric 1 of this embodiment is preferably used as the surface sheet 70 of the underpants type disposable diaper 100 used for a wearer's skin contact surface. Moreover, it can also be used as the outer layer sheet 62 and the inner layer sheet 61 of the outer packaging material 60, the back sheet 80, and the side cuff 55 forming sheet. As the member of each part when the nonwoven fabric 1 is not used, those used for absorbent articles such as disposable diapers can be used without particular limitation. For example, as the top sheet 70, a liquid-permeable nonwoven fabric, a perforated film, or a laminate thereof can be used, and as the back sheet 80, a resin film or a laminate of the resin film and the nonwoven fabric can be used. Can do. As the sheet for forming the side cuff 55, a stretchable film, a nonwoven fabric, a woven fabric, or a laminated sheet thereof can be used. As the inner layer sheet 61 and the outer layer sheet 62, a water-repellent nonwoven fabric or the like can be used.

As the absorber 40, those conventionally used for absorbent articles such as disposable diapers can be used without particular limitation. For example, as the absorbent body 40, a fiber aggregate of a fiber material such as pulp or a material in which a superabsorbent polymer is supported and wrapped with a covering material such as tissue paper or a water-permeable nonwoven fabric is used. Can be used.
As the elastic member 56 for forming side cuffs, the waist elastic member 63, and the leg elastic member 64, those normally used for absorbent articles such as disposable diapers can be used without particular limitation. For example, a stretchable material made of natural rubber, polyurethane, polystyrene-polyisoprene copolymer, polystyrene-polybutadiene copolymer, polyethylene-α olefin copolymer such as ethyl acrylate-ethylene, or the like can be used.

  If the nonwoven fabric 1 of this embodiment is used for the surface sheet 70 so that the surface with the fibers 20 having the free ends 20b becomes the skin contact surface of the wearer of the pants-type disposable diaper 100, the disposable diaper The feeling of plumpness of the entire 100 surface sheet 70 is improved, the cushioning property is also improved, and the touch is improved. Moreover, since the nonwoven fabric 1 is hydrophilic, a wearer's bodily fluid passes through the nonwoven fabric 1 and is easy to transfer to the absorber 40, and the hydrophilicity of the fiber 20 having the free end portion 20b determines the fiber assembly 11. Since it is lower than the hydrophilicity of the non-raised fiber which comprises, the bodily fluid which transferred to the absorber 40 cannot return to the surface of the said fiber assembly 11 from the fiber assembly 11 easily.

The nonwoven fabric of this invention is not restrict | limited to the nonwoven fabric 1 of the above-mentioned this embodiment at all, and can be changed suitably.
Moreover, the manufacturing method of the nonwoven fabric of this invention is not restrict | limited at all to the manufacturing method of the above-mentioned embodiment, It can change suitably.

  For example, in the manufacturing method of the nonwoven fabric 1 of this embodiment described above, the raw material nonwoven fabric 10 is subjected to a partial stretching process, other than using the raw material nonwoven fabric 10 that is heat-treated at a temperature lower than the melting point of the fiber that is configured in a separate step. The heat treatment may be performed at a temperature lower than the melting point of the fibers constituting the raw material nonwoven fabric 10. Specifically, in the manufacturing apparatus for the nonwoven fabric 1, a hot air treatment unit is provided on the upstream side of the partial stretching unit 4, and the raw nonwoven fabric 10 heat-treated by the hot air processing unit is continuously steel-matched in the partial stretching unit 4. It may be conveyed between the pair of rollers 41 and 42 of the embossing roller 43 and subjected to partial stretching. Thus, by performing a heat treatment and a partial stretching process in a series of flows, there is an effect that the nonwoven fabric 1 having further improved touch performance and absorption performance can be produced.

The following nonwoven fabric and manufacturing method are further disclosed regarding the embodiment mentioned above.
<1>
A hydrophilic nonwoven fabric comprising a fiber assembly in which long fibers are fixed by a heat-sealing part,
A part of the long fiber is broken, one end is fixed by the heat-sealing part, and the other end is a free end and stands up away from the fiber assembly. Comprising fibers having
The nonwoven fabric whose hydrophilicity of the fiber which has the said free end part is lower than the hydrophilicity of the fiber which comprises the said fiber assembly.
<2>
The fiber which has the said free end part is a nonwoven fabric as described in said <1> whose contact angle with respect to a pure water is higher than 80 degrees.
<3>
<1> or <2>, wherein the contact angle of the fiber having the free end 20b with respect to pure water is preferably higher than 80 °, more preferably higher than 85 °, and particularly preferably 90 ° or more. The nonwoven fabric described in 1.
<4>
The contact angle of the fibers constituting the fiber assembly with respect to pure water is preferably lower than 90 °, more preferably lower than 85 °, and particularly preferably 80 ° or less as described in <1> to <3>. The nonwoven fabric of any one.
<5>
The contact angle of the fiber having the free end portion 20b is preferably higher by a difference of 5 ° or more and more preferably by a difference of 10 ° or more with respect to the contact angle of the fibers constituting the fiber assembly. The nonwoven fabric according to any one of <1> to <4>.
<6>
The nonwoven fabric according to any one of <1> to <5>, wherein a ratio of fibers having an interfiber distance of 150 μm or more and 300 μm or less among fibers constituting the nonwoven fabric is 30% or more.
<7>
Of the fibers constituting the nonwoven fabric, the proportion of fibers having an interfiber distance of 150 μm or more and 300 μm or less is preferably 30% or more, more preferably 35% or more, and particularly preferably 40% or more. The nonwoven fabric according to any one of <1> to <6>, which is preferable.
<8>
<1> to <1>, wherein the nonwoven fabric includes raised fibers including fibers having the free end portions and loop-like fibers that stand in a loop shape between the heat-sealed portions. The nonwoven fabric according to any one of <7>.
<9>
The nonwoven fabric according to any one of <1> to <8>, wherein the number of raised fibers is 8 / cm or more and the raising height is 1.5 mm or less.
<10>
The number of the raised fibers is preferably 8 / cm or more, more preferably 12 / cm or more, 100 / cm or less, more preferably 40 / cm or less, The nonwoven fabric as described in <9>.
<11>
<9> or <10> according to <9> or <10>, wherein the raised height of the raised fibers is preferably 0.2 mm or more, more preferably 0.5 mm or more, and preferably 1.0 mm or less.
<12>
The fiber which has the said free end part is a nonwoven fabric any one of said <1>-<11> containing the fiber with which the said free end part at the said other end part side is thick.
<13>
The non-woven fabric according to <12>, wherein the ratio of the fibers having a thick free end is preferably 20% or more, more preferably 30% or more, and particularly preferably 40% or more. .
<14> The nonwoven fabric according to any one of <1> to <13>, wherein the fiber having the free end has an average fiber diameter smaller than an average fiber diameter of fibers constituting the fiber assembly.
<15>
<1> to <14>, wherein the average fiber diameter of the fibers having the free end is preferably 98% or less and 40% or more, and 97% or less and 70% or more of the average fiber diameter of the fibers constituting the fiber assembly. The nonwoven fabric according to any one of 1.
<16> The non-woven fabric according to any one of <8> to <15>, wherein the raised fiber has an average fiber diameter smaller than an average fiber diameter of the non-raised fiber.
<17>
<8> to <16>, wherein the average fiber diameter of the raised fibers is preferably 98% or less and 40% or more of the average fiber diameter of non-raised fibers, and is 97% or less and 70% or more. The nonwoven fabric according to 1.
<18>
The non-woven fabric has a compression characteristic value at a minute load of 17.6 (cN / cm ² ) / mm or less, and a breaking strength in a direction perpendicular to the orientation direction of the long fibers is 5.00 N / 5 cm or more, The nonwoven fabric according to any one of <1> to <17>, wherein the basis weight is 5 g / m ² or more and 100 g / m ² or less.
<19>
The compression characteristic value is 17.6 (cN / cm ² ) / mm or less, preferably 14.7 (cN / cm ² ) / mm or less, 9.80 (cN / cm ² ) / mm. The non-woven fabric according to <18>, which is more preferably as follows.
<20>
The nonwoven fabric preferably has a value of breaking strength of the nonwoven fabric of 5.0 N / 50 mm or more, more preferably 8.0 N / 50 mm or more and 30.0 N / 50 mm or less, <1> to < The nonwoven fabric according to any one of 19>.
<21>
The nonwoven fabric according to any one of <1> to <20>, wherein the raw material nonwoven fabric of the nonwoven fabric is formed by hydrophilizing hydrophobic long fibers.
<22>
<21> The raw material nonwoven fabric is hydrophilized with a hydrophilizing agent, and the amount of the hydrophilizing agent is preferably 0.1% by weight or more and 20% by weight or less based on the weight of the raw material nonwoven fabric. The nonwoven fabric described.
<23>
The non-woven fabric has a fiber assembly composed of non-raising fibers other than the fibers having the free end, the loop-shaped fibers, and the raised fibers, <1> to < 22. The nonwoven fabric according to any one of 22>.
<24>
Any of <1> to <23>, wherein the nonwoven fabric has a bulk softness of preferably 10 cN or less, more preferably 5.9 cN or less, and preferably 0.5 cN or more. Or the nonwoven fabric according to 1.
<25>
The raw material nonwoven fabric preferably has a bulk softness of 15 cN or less, more preferably 10 cN or less, more preferably 3 cN or more, and further preferably 5 cN or more. The nonwoven fabric according to any one of <24>.

<26>
The method for producing a nonwoven fabric according to any one of <1> to <25>,
A hydrophilic non-woven fabric that has been subjected to a hydrophilic treatment comprising a fiber assembly in which long fibers are fixed by a heat-sealing part is supplied between a pair of concavo-convex rollers, and subjected to partial stretching processing at each of a plurality of locations of the non-woven fabric,
The non-woven fabric that has been partially stretched is supplied to a convex roller having a convex portion on the peripheral surface, and is stretched while breaking a part of the long fiber to raise the fiber aggregate, A non-woven fabric which forms a fiber having a free end stretched more than the constituent fiber, and lowers the hydrophilicity of the fiber having the free end lower than the non-raised fiber constituting the fiber assembly. Manufacturing method.
<27>
The partial stretching process is performed using a pair of concave and convex rollers,
One roller has a plurality of convex portions on the peripheral surface, and the other roller has a concave portion into which the convex portion enters the peripheral surface at a position corresponding to the convex portion of the one roller.
The method for producing a nonwoven fabric according to <26>, wherein a meshing depth between the convex portion of one of the rollers and the convex portion of the other roller is 3.5 mm or more and 10 mm or less.
<28>
3. The meshing depth is 3.5 mm or more, preferably 3.7 mm or more, more preferably 4 mm or more, and 5 mm or less, preferably 4.8 mm or less. It is still more preferable that it is 5 mm or less, The manufacturing method of the nonwoven fabric as described in said <26> or <27>.
<29>
In the napping process, a sandblast roller is used as a convex roller, and the density of the convex portions of the sandblast roller is 1000 / cm ² or more and 3000 / cm ² or less. Manufacturing method of non-woven fabric.
<30>
The density of the convex portions of the sandblast roller is preferably 1000 / cm ² or more and 3000 / cm ² or less, more preferably 1200 / cm ² or more and 2500 / cm ² or less, <29 The manufacturing method of the nonwoven fabric as described in>.
<31>
The method for producing a nonwoven fabric according to any one of <26> to <30>, wherein the fiber draw ratio is preferably 3% or more and 100% or less, and more preferably 5% or more and 50% or less. .
<32>
The absorbent article which used the nonwoven fabric in any one of said <1>-<25> for the surface sheet.
<33>
A disposable diaper comprising a top sheet, a back sheet and an absorbent body sandwiched between both sheets, wherein the non-woven fabric according to <1> to <25> is used for the top sheet.

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

[Example 1]
As a raw material non-woven fabric, it has three layers of spunbond non-woven fabric made of polypropylene homopolymer resin, basis weight 18 g / m ² , fiber diameter 16 μm, area ratio of thermocompression bonding part (heat fusion part by embossing), hydrophilizing agent A spunbonded nonwoven fabric (SSS nonwoven fabric) that was hydrophilized by adding 1% by weight was used. The bulk softness of this nonwoven fabric is 9.6 cN. Using this non-woven fabric, a non-woven fabric was produced by performing partial stretching and raising. A steel matching embossing roller 43 was used as a partial stretching process. The convex portions 411 and 421 in the roller 43 have a height of 5.0 mm, and the depth D of engagement between the convex portions 411 of the roller 41 and the convex portions 421 of the roller 42 is 4.0 mm. there were. Further, the distance (pitch P ₂ ) between the convex portions 411; 421 adjacent in the rotation axis direction is 7 mm, and the distance (pitch P ₁ ) between the convex portions 411 and 421 adjacent in the circumferential direction is 7 mm. It was. The temperature of the steel matching embossing roller 43 was 26 ° C., the peripheral speed of the steel matching embossing roller 43 was 20 m / min, and the conveying speed of the raw material nonwoven fabric was 20 m / min. Next, as the raised roller 51, a sand blast roller in which the height of each projection 511 was 0.2 mm and the density of the projections was about 2000 pieces / cm ² was used. The conveyance speed of the raw material nonwoven fabric was 20 m / min, and the convex roller 51 was rotated at a circumferential speed twice as high as the reverse direction of the nonwoven fabric conveyance direction. The hugging angle was 60 degrees. The surface sheet is removed from the product of “Mary's (registered trademark) Mary's Pants” manufactured by Kao Corporation, and the non-woven fabric produced as described above is used instead, and the surface having raised fibers is used on the skin side of the wearer. The disposable diaper of Example 1 was produced so that it might become the side which contact | abuts.

[Example 2]
In Example 1, after the partial stretching process, the convex roller 51 was rotated at a peripheral speed four times the sandblast roller, which is the convex roller 51 used for the raising process, in the direction opposite to the conveyance direction of the nonwoven fabric. Other than that was carried out similarly to Example 1, and produced the disposable diaper of Example 2. FIG.

[Example 3]
In Example 1, in the steel matching embossing roller 43 used for the partial stretching process, the depth D of engagement between each convex portion 411 of the roller 41 and each convex portion 421 of the roller 42 is 3.5 mm, and the convex used for raising The convex roller 51 was rotated at a circumferential speed twice that of the sandblast roller, which is the roller 51, in the direction opposite to the conveyance direction of the nonwoven fabric. Other than that was carried out similarly to Example 1, and produced the disposable diaper of Example 3. FIG.

[Example 4]
In Example 1, in the steel matching embossing roller 43 used for the partial stretching process, the engagement depth D of each convex portion 411 of the roller 41 and each convex portion 421 of the roller 42 is 4.5 mm, and the convex used for raising The convex roller 51 was rotated at a circumferential speed twice that of the sandblast roller, which is the roller 51, in the direction opposite to the conveyance direction of the nonwoven fabric. Other than that was carried out similarly to Example 1, and produced the disposable diaper of Example 4. FIG.

[Example 5]
It has three layers of spunbond nonwoven fabric made of polypropylene homopolymer resin, weight per unit of 17 g / m ² , fiber diameter 15 μm, area ratio of thermocompression bonding part (heat fusion part by embossing) 17%, hydrophilizing agent 1% by weight A spunbonded non-woven fabric (SSS non-woven fabric) which was added and subjected to a hydrophilic treatment was used. The bulk softness of this nonwoven fabric is 5.0 cN. Using this nonwoven fabric, in the steel matching embossing roller 43 used for the partial stretching process, the depth D of engagement between each convex portion 411 of the roller 41 and each convex portion 421 of the roller 42 is 4.5 mm, and the convexity used for raising The convex roller 51 was rotated at a peripheral speed of 4 times the sandblast roller as the roller 51 in the direction opposite to the conveyance direction of the nonwoven fabric. Other than that was carried out similarly to Example 1, and produced the disposable diaper of Example 5. FIG.

[Example 6]
It has 3 layers of spunbond nonwoven fabric made of polypropylene homopolymer resin, weight per unit of 17g / m ² , fiber diameter 16μm, area ratio of thermocompression bonding part (heat fusion part by embossing) 17%, hydrophilizing agent 1% by weight A spunbonded non-woven fabric (SSS non-woven fabric) which was added and subjected to a hydrophilic treatment was used. The bulk softness of this nonwoven fabric is 12 cN. Using this nonwoven fabric, in the steel matching embossing roller 43 used for the partial stretching process, the depth D of engagement between each convex portion 411 of the roller 41 and each convex portion 421 of the roller 42 is 4.5 mm, and the convexity used for raising The convex roller 51 was rotated at a peripheral speed of 4 times the sandblast roller as the roller 51 in the direction opposite to the conveyance direction of the nonwoven fabric. Other than that was carried out similarly to Example 1, and produced the disposable diaper of Example 5. FIG.

[Reference Example 1]
In Example 1, in the steel matching embossing roller 43 used for partial stretching, the depth D of engagement between the convex portions 411 of the roller 41 and the convex portions 421 of the roller 42 is 2.7 mm, and the convexity used for raising The convex roller 51 was rotated at a circumferential speed twice that of the sandblast roller, which is the roller 51, in the direction opposite to the conveyance direction of the nonwoven fabric. Other than that was carried out similarly to Example 1, and produced the disposable diaper of the reference example 1. FIG.

[Comparative Example 1]
The disposable diaper of the comparative example 1 was produced using the raw material nonwoven fabric used for Example 1 instead of the surface sheet removed from the product of “Mary's (registered trademark) Mary's pants” manufactured by Kao Corporation.

[Comparative Example 2]
3 layers of spunbond nonwoven fabric made of polypropylene homopolymer resin, basis weight 18g / m ² , fiber diameter 16μm, area ratio of thermocompression bonding part (heat fusion part by embossing) 9%, not hydrophilized The spunbonded nonwoven fabric (nonwoven fabric that has not been subjected to hydrophilic treatment of the raw material nonwoven fabric used in Example 1) is used in place of the surface sheet removed from the product of “Mary's (registered trademark) Mary's Pants” manufactured by Kao Corporation. Thus, a disposable diaper of Comparative Example 2 was produced.

[Performance evaluation]
About the nonwoven fabric used for the surface sheet of the disposable diaper of Examples 1-6, Reference Example 1, and Comparative Examples 1-2, the measuring method of the bulk softness mentioned above, the measuring method of the contact angle mentioned above, the distance between fibers mentioned above Measurement method, measurement method for breaking strength, measurement method for minute load, measurement method for fiber diameter, measurement method for fiber diameter, measurement method for fiber diameter, measurement method for the number of raised fibers described above Measured based on each. The results are shown in Table 1 below.

Moreover, the touch property was evaluated according to the following method about the nonwoven fabric used for the surface sheet of the disposable diaper of Examples 1-6, Reference Example 1, and Comparative Examples 1-2. The evaluation environment was a room temperature of 22 ° C. and a humidity of 65% RH. The results are shown in Table 1 below.
Moreover, about the disposable diaper of Examples 1-6, Reference Example 1, and Comparative Examples 1-2, the absorptivity and the liquid return property were evaluated according to the following method, respectively. The evaluation environment was a room temperature of 22 ° C. and a humidity of 65% RH. The results are shown in Table 1 below.

[Evaluation of touch]
10 stages when the nonwoven fabric of Comparative Example 1 is used as a reference (5 points) by 10 professional panelists for the nonwoven fabrics used in the top sheets of the disposable diapers of Examples 1 to 6, Reference Example 1 and Comparative Examples 1 to 2. Sensory evaluation of the surface of the nonwoven fabric (smoothness) was performed, and the average value of three sheets for each nonwoven fabric was calculated by rounding to the nearest whole number.

[Evaluation of absorbency]
The waistline gathers and the leg gathers were removed from the disposable diapers of Examples 1 to 6, Reference Example 1 and Comparative Examples 1 to 2, and fixed horizontally with the topsheet side up in the unfolded state. An acrylic plate with a cylindrical inlet was placed on the top sheet, and a load of 2 kg was placed on the back side and ventral side of the diaper on the acrylic plate. The injection port provided in the acrylic plate has a cylindrical shape (height 53 mm) with an inner diameter of 36 mm, and the acrylic plate has a cylindrical shape at a position 1/3 in the longitudinal direction and at the center in the width direction. A through hole having an inner diameter of 36 mm is formed, the axis of which coincides with the center of the inlet and communicates between the inside of the cylindrical inlet and the surface sheet facing surface of the acrylic plate. Place the acrylic plate so that the central axis of the acrylic cylindrical injection port is at a position 125 mm from the tip of the end on the ventral side in the longitudinal direction of the covering sheet covering the absorbent core of the diaper. A total of 160 g of water was injected. Physiological saline was injected in four portions of 40 g at 10 minute intervals. The time until the entire amount of 160 g was absorbed by the diaper was measured. The average value of three times for each disposable diaper was rounded to the nearest whole number, and the absorption time was measured. The results are shown in Table 1 below.

[Evaluation of liquid return properties]
Subsequent to the above-described evaluation of absorbability, the disposable diapers of Examples 1 to 6, Reference Example 1 and Comparative Examples 1 to 2 were allowed to stand for 10 minutes from the state in which 160 g of physiological saline was injected. Thereafter, the acrylic plate was removed, and 16 sheets of 5C filter paper made by Toyo Roshi Kaisha, Ltd. were stacked on the physiological saline absorption site, and a load was further applied for 2 minutes to absorb the physiological saline on the filter paper. The load was such that 3.5 kg was applied to an area of 10 cm × 10 cm. After 2 minutes, the load was removed, and the weight of the filter paper that absorbed physiological saline was measured. The weight of the filter paper before absorption was subtracted from this weight, and the value was determined as the liquid return amount of each diaper. About each disposable diaper, the average value of 3 times was rounded off to the integer digit, and the liquid return amount was measured. The results are shown in Table 1 below.

  As is clear from the results shown in Table 1, in the nonwoven fabrics of Examples 1 to 6, the hydrophilicity of the fibers raised by processing becomes hydrophobic compared to the nonwoven fabric of Comparative Example 1, and the absorbency and liquid return It was found that the performance was improved. Furthermore, it was found that the nonwoven fabrics of Examples 1 to 6 had higher cushioning properties than the nonwoven fabrics of Comparative Examples 1 and 2. Therefore, compared with the nonwoven fabric of Examples 1-2, the nonwoven fabric of Examples 1-6 improved cushioning property, and it turned out that it is hard to reverse a liquid with the improvement of liquid permeability.

DESCRIPTION OF SYMBOLS 1 Non-woven fabric 2 Long fiber 20 Fiber in which only one end is fixed by heat fusion part 3 20a One end 20b Free end 21 Fiber in which free end 20b is thick 22 Fiber in which free end 20b is not thick 23 Loop-like fiber 3 Heat fusion part 11 Fiber assembly 4 Partially stretched part 41, 42 Pair of rollers 411, 421 Convex part 412, 422 Concave part 43 Steel matching embossed roller 44, 45 Conveying roller 5 Brushed part 51 Convex part Roller 511 Protruding portion 52, 53 Conveying roller 10, 10 'Raw material nonwoven fabric 104 Measurement sample 105 Fold 106a Fiber 107 crossing twice 108 Hole virtual line 100 Pants-type disposable diaper 40 Absorber 50 Absorbent body 55 Side cuff 56 Side cuff Elastic member 60 for forming Outer packaging material 61 Inner layer sheet 62 Outer layer sheet 63 Stroke elastic member 64 Leg elastic member 70 Top sheet 80 Back sheet A Back side, B Abdomen, C Inseam

Claims (13)

A hydrophilic nonwoven fabric comprising a fiber assembly in which long fibers are fixed by a heat-sealing part,
A part of the long fiber is broken, one end is fixed by the heat-sealing part, and the other end is a free end and stands up away from the fiber assembly. Comprising fibers having
The nonwoven fabric whose hydrophilicity of the fiber which has the said free end part is lower than the hydrophilicity of the fiber which comprises the said fiber assembly.   The nonwoven fabric according to claim 1, wherein the fiber having the free end has a contact angle with respect to pure water of higher than 80 °.   The nonwoven fabric according to claim 1 or 2, wherein the hydrophilicity of the fiber having the free end is 3 ° or more lower than the hydrophilicity of the fiber constituting the fiber assembly.   The said nonwoven fabric is a nonwoven fabric in any one of Claims 1-3 whose ratio of the fiber whose distance between fibers is 150 micrometers or more and 300 micrometers or less is 30% or more among the fibers which comprise this nonwoven fabric.   The said nonwoven fabric has comprised the fiber which has fluffed including the fiber which has the said free end part, and the loop-like fiber which stands up in a loop shape between the said heat-fusion parts. The nonwoven fabric of any one of these.   The nonwoven fabric according to any one of claims 1 to 5, wherein the number of the raised fibers is 8 / cm or more and the raised height is 1.5 mm or less.   The fiber which has the said free end part is a nonwoven fabric in any one of Claims 1-6 containing the fiber with which the said free end part of the said other end part side is thick.   The nonwoven fabric according to any one of claims 1 to 7, wherein the fiber having the free end portion has an average fiber diameter smaller than an average fiber diameter of fibers constituting the fiber assembly. The non-woven fabric has a compression characteristic value at a minute load of 18.0 (gf / cm ² ) / mm or less, and a breaking strength in a direction perpendicular to the orientation direction of the long fibers is 5.00 N / 5 cm or more, The nonwoven fabric according to any one of claims 1 to 8, wherein the basis weight is 5 g / m ² or more and 100 g / m ² or less. It is a manufacturing method of the nonwoven fabric according to any one of claims 1 to 9,
A hydrophilic non-woven fabric that has been subjected to a hydrophilic treatment comprising a fiber assembly in which long fibers are fixed by a heat-sealing part is supplied between a pair of concavo-convex rollers, and subjected to partial stretching processing at each of a plurality of locations of the non-woven fabric,
The non-woven fabric that has been partially stretched is supplied to a convex roller having a convex portion on the peripheral surface, and is stretched while breaking a part of the long fiber to raise the fiber aggregate, A method for producing a nonwoven fabric, wherein a fiber having a free end that is stretched more than a constituent fiber is formed, and the hydrophilicity of the fiber having the free end is made lower than the hydrophilicity of the fiber constituting the fiber assembly. The partial stretching process is performed using a pair of concave and convex rollers,
One roller has a plurality of convex portions on the peripheral surface, and the other roller has a concave portion into which the convex portion enters the peripheral surface at a position corresponding to the convex portion of the one roller.
The method for producing a nonwoven fabric according to claim 10, wherein a meshing depth between the convex portion of one of the rollers and the convex portion of the other roller is 3.5 mm or more and 10 mm or less. The method for producing a nonwoven fabric according to claim 10 or 11, wherein the raising process uses a sand blast roller as a convex roller, and the density of the convex portions of the sand blast roller is 1000 / cm ² or more and 3000 / cm ² or less.   The absorbent article which used the nonwoven fabric of any one of Claims 1-9 for the surface sheet.

Images