JP6772047B2 - Nonwoven fabric and its manufacturing method - Google Patents

Description

The present invention relates to a non-woven fabric and a method for producing the same.

The constituent fibers of the non-woven fabric are generally produced by continuously discharging a molten resin from a fine nozzle and pulling and thinning the discharged molten resin. For example, melt-blown non-woven fabric is manufactured by continuously ejecting molten thermoplastic resin from a nozzle and stretching it to form fibers by blowing out a high-temperature and high-speed air flow, and integrating the fibers to form a web. (See Patent Document 1).

A technique is known in which particles are fixed to the surface of constituent fibers of a non-woven fabric to impart various properties to the non-woven fabric. For example, Patent Document 2 describes a non-woven fabric containing a constituent fiber in which a plurality of particles are fixed to the surface of the fiber and a plurality of convex portions caused by the particles protrude from the surface of the fiber. In the example of, particles having a particle size of 5.2 to 55 μm are used. The non-woven fabric described in Patent Document 2 is obtained by spraying particles containing a thermoplastic resin on a raw non-woven fabric whose constituent fibers are fibers containing a thermoplastic resin of the same type or different from that of the thermoplastic resin, and then heat-treating the particles. It is manufactured through a step of fixing the fibers by fusion. The non-woven fabric described in Patent Document 2 has a small contact area between the water and the human skin when the non-woven fabric comes into contact with human skin, even if some water is present on the surface of the non-woven fabric. It is said that there is an advantage that it is difficult to feel the dampness caused by the moisture, and suitable applications thereof include a member located on the outermost surface of an absorbent article such as a disposable diaper or a sanitary napkin, for example, a back sheet. Has been done.

Further, Patent Document 3 describes, as a polished article using a non-woven fabric, one in which organic or inorganic abrasive particles having an average particle size range of 0.1 to 50 μm are fixed to the constituent fibers of the non-woven fabric via a binder. The polished article described in Patent Document 3 is manufactured through a step of applying a precursor of a binder to a non-woven fabric, applying polishing particles to the precursor, and then exposing the precursor to conditions that cause curing of the precursor. ..

Further, conventionally, when a molten resin is molded to produce a resin product having a predetermined shape, gas is added and mixed with the molten resin. For example, Patent Document 4 describes that in the production of synthetic fibers by the melt spinning method, foamed fibers are produced by adding and mixing a gas such as carbon dioxide or nitrogen to a molten resin which is a raw material thereof. This foamed fiber is a filament or staple-like fiber containing a large number of discontinuous pores, is lightweight due to its low density, and has excellent heat retention due to its pores, and is therefore suitable for carpets, cotton padding, clothing, etc. used.

Further, in Patent Document 5, after injection molding a polymer base material (for example, a reflector of an automobile headlight) using an injection molding machine, pressurized carbon dioxide in which a modifying material is dissolved is used as the polymer group in the same injection molding machine. It is described that a plating film is formed on the polymer base material by performing electroless plating treatment in contact with the material, and supercritical carbon dioxide having a pressure of 7.38 MPa or more and 20 MPa or less is used as the pressurized carbon dioxide. It is stated that.

International Publication No. 2012/077638 Japanese Unexamined Patent Publication No. 2016-108714 Special Table 2003-523837 Japanese Unexamined Patent Publication No. 2003-129342 Japanese Unexamined Patent Publication No. 2008-188799

Non-woven fabrics such as melt-blown non-woven fabrics have a flat surface and a silky feel, and are generally recognized as having a good texture. Therefore, items that come into contact with human skin, such as members of disposable diapers that come into contact with the wearer's skin. Is used for. On the other hand, for example, in the case of metal and paper, conventionally, for the purpose of enhancing the texture and producing a high-class feeling, the surface is subjected to a process of applying a fine uneven shape called satin finish, and the fine uneven shape is performed. And, due to the effect of suppressing slippage, it realizes a unique rough feel and a sense of luxury.

With regard to non-woven fabrics, there are cases where a high-class texture is required, for example, when used for gift wrapping, against the background of recent expansion of applications. However, the non-woven fabric is an aggregate composed of fibers having the same shape at any part of the cross section, and it is difficult to give a fine uneven shape by a pressing treatment on the surface such as satin finish. Further, for example, as described in Patent Document 3, it is possible to fix the particles to the constituent fibers of the non-woven fabric via a binder and to realize a rough feel by the convex portions caused by the particles. It is difficult to carry out such a method practically in consideration of the need for the particles to be prevented from falling off from the non-woven fabric and the labor during processing.

Therefore, an object of the present invention is to provide a non-woven fabric having a unique texture and a high-class feeling, and a method for producing the same.

The present invention includes a fiber and a resin lump that adheres to the fiber, and the resin lump is a non-woven fabric containing the resin that forms the fiber, and there are a plurality of large resin lumps. Provided is a non-woven fabric having a length of 10 μm or more in the non-woven fabric thickness direction and a part protruding from the surface of the non-woven fabric, and an average length of the plurality of large resin lumps in the non-woven fabric thickness direction of 60 μm or more. is there.

Further, in the present invention, the molten resin is discharged from a nozzle through a flow path, and the molten resin is stretched by blowing hot air onto the discharged molten resin to form fibers, and the fibers are accumulated to form a non-woven fabric. A method for producing a non-woven fabric, which comprises a step of adding gas or a gas generating substance that generates gas by heating to the molten resin before being discharged from the nozzle, and the pressure in the flow path is 2 MPa or more. Is to provide.

Further, in the present invention, a member having a surface that can come into contact with the skin of the wearer is formed of the non-woven fabric of the present invention, and the large resin mass protrudes from the surface that can come into contact with the skin of the wearer. Is to provide.

According to the present invention, there is provided a non-woven fabric having a unique rough texture and a high-class feeling, and a method for producing the same. Also according to the present invention is provided a worn article with such a high quality non-woven fabric.

FIG. 1 is an enlarged diagram schematically showing one embodiment of the nonwoven fabric of the present invention. FIG. 2 is a cross-sectional view schematically showing a cross section along the thickness direction of the surface layer portion of the nonwoven fabric of the present invention together with an example of a large resin mass existing in the surface layer portion. FIG. 3 is a schematic view showing an embodiment of the method for producing a nonwoven fabric of the present invention. FIG. 4 is a schematic cross-sectional view of the nozzle and its peripheral portion (die) in the manufacturing apparatus shown in FIG.

Hereinafter, the present invention will be described based on its preferred embodiment with reference to the drawings. The present invention relates to a non-woven fabric. The non-woven fabric referred to in the present invention is a cloth in which constituent fibers are irregularly deposited in an indefinite direction, which is opposite to a cloth in which constituent fibers are regularly arranged such as a woven fabric or a knitted fabric. It is in the position of.

There are various types of non-woven fabrics depending on the manufacturing method thereof. For example, air-through non-woven fabric, spunbond non-woven fabric, spunlace non-woven fabric, melt blown non-woven fabric, resin bond non-woven fabric, needle punch non-woven fabric, heat roll non-woven fabric and the like can be mentioned. All of these non-woven fabrics are subject to the present invention. The present invention also applies to a composite sheet composed of a laminate of two or more non-woven fabrics, or a laminate of one or more non-woven fabrics and a sheet material other than the non-woven fabric, for example, a film. Examples of the laminate of the non-woven fabric include spunbond-melt blown-spanbond (SMS) non-woven fabric and spunbond-melt blown (SM) non-woven fabric. Examples of the composite sheet include a laminate of a non-woven fabric and a liquid-impermeable or liquid-impermeable moisture-permeable sheet. A particularly suitable application object of the present invention is a melt-blown non-woven fabric.

The non-woven fabric is composed of at least one constituent fiber. The constituent fibers may be one type or two or more types. The constituent fibers may be short fibers having a length of, for example, several mm to several tens of mm, or may be continuous filaments having an infinite length. Whether to use short fibers or continuous filaments may be appropriately selected according to the method for producing the non-woven fabric.

FIG. 1 shows an embodiment of the nonwoven fabric of the present invention. As shown in the figure, the non-woven fabric 1 of the present embodiment contains the fibers 2 and the resin mass 3 fixed to the fibers 2. In FIG. 1, the black irregularly shaped portion is the resin mass 3, which is scattered in both the plane direction and the thickness direction of the nonwoven fabric 1. In the non-woven fabric 1, the distribution pattern of the resin lumps 3 is irregular, but it may be regular. According to the method for producing a non-woven fabric of the present invention described later, the distribution pattern of the resin lump 3 is usually irregular. The shape of the plurality of resin lumps 3 contained in the non-woven fabric 1 is usually not constant but irregular.

The fiber 2 is preferably composed of a fiber-forming resin. Examples of such resins include various thermoplastic resins. Examples of the thermoplastic resin include polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, polyamide resins, vinyl resins such as polyvinyl chloride and polystyrene, and acrylic resins such as polyacrylic acid and polymethyl methacrylate. , Fluororesin such as polypropylene, etc., and one of these can be used alone or in combination of two or more.

The fiber diameter of the fiber 2 can be appropriately set according to the specific use of the non-woven fabric. When the non-woven fabric 1 is used as a constituent member of a worn article such as an absorbent article, the fiber diameter of the fiber 2 is preferably 0.05 μm or more, more preferably 0.1 μm or more, and preferably 60 μm or less. It is preferably 30 μm or less. The fiber diameter of the fiber in the non-woven fabric is measured by the following method. That is, the surface of the non-woven fabric is measured from the average value of 50 fibers when observed using a scanning electron microscope.

The resin mass 3 contains a resin that forms the fibers 2. The non-woven fabric 1 is usually an aggregate of fibers 2 obtained by pulling and thinning the molten resin discharged from a nozzle according to the method for producing a non-woven fabric of the present invention described later, and the resin mass 3 is in this molten resin. Made of resin. The resin lump 3 is an essential component that is a factor of the unique texture of the non-woven fabric 1, and the important resin lump 3 contains a resin having the same quality as the fiber 2 that is the main component of the non-woven fabric 1. As a result, the adhesive force of the resin lump 3 to the fiber 2 is increased as compared with the case where the resin lump 3 is formed of a material different from the fiber 2, and the resin lump 3 is detached from the non-woven fabric 1. It becomes difficult. Further, since the resin lump 3 is formed of the same resin as the fiber 2, the productivity of the non-woven fabric 1 can be expected to be improved because a step such as a separate addition of the material for forming the resin lump 3 is not required.

It is fixed to the fiber 2 of the resin mass 3 by fusion. According to the method for producing a non-woven fabric of the present invention described later, the resin mass 3 is fixed to the fiber 2 by fusion, so that a fixing means such as an adhesive is not required. Further, the number of fibers 2 to which one resin mass 3 is fixed is not particularly limited, and there may be one or a plurality of fibers.

One of the main features of the non-woven fabric 1 is that it has a unique rough touch, and as shown in FIG. 1, this characteristic touch is a kind of resin lump 3 on the non-woven fabric 1. This is due to the existence of a plurality of large resin lumps 30, and more specifically, as shown in FIG. 2, the resin lumps 3 are formed on the surface layer portion of the non-woven fabric 1, that is, the surface 1S of the non-woven fabric 1 and its vicinity. This is because there are a plurality of large resin lumps 30 having a length L0 in the thickness direction Z of the nonwoven fabric of 10 μm or more and a part of which protrudes from the surface 1S of the nonwoven fabric 1. That is, the large resin lump 30 which is a kind of the resin lump 3 has a length L0 along the thickness direction Z of the non-woven fabric 1 of 10 μm or more and a predetermined protrusion length L1 from the surface 1S of the non-woven fabric 1 to the outside in the thickness direction Z. Other than this point, it is the same as the other resin lumps 3 contained in the non-woven fabric 1, and contains the same resin as the fibers 2 which are the constituent fibers of the non-woven fabric 1. The present invention includes both a form in which a part of the resin lump contained in the nonwoven fabric is a large resin lump and a form in which the entire resin lump contained in the nonwoven fabric is a large resin lump. According to the method for producing a nonwoven fabric of the present invention described later, a nonwoven fabric of the former form is usually obtained.

The "surface of the non-woven fabric" as used in the present invention means that when a cross section along the thickness direction of the non-woven fabric is observed by using a scanning electron microscope (manufactured by JCM-5100 Nippon Denshi Co., Ltd.) at a magnification of 200 times, the enlargement thereof is observed. In the image, it is a surface (a surface that can be observed when the non-woven fabric is observed from the outside) formed by a plurality of fibers located on the outermost side in the non-woven fabric thickness direction and orthogonal to the non-woven fabric thickness direction. When determining the surface of the non-woven fabric based on the enlarged image, it is located at the outermost position in the non-woven fabric thickness direction after excluding irregular fibers that independently greatly protrude outward in the non-woven fabric thickness direction. A virtual surface extending in a direction orthogonal to the thickness direction of the nonwoven fabric is formed by a part of the plurality of fibers, and the virtual surface is used as the surface of the nonwoven fabric.

In the non-woven fabric 1, the average length of each of the plurality of large resin lumps 30 in the non-woven fabric thickness direction Z (the average value of the length L0 shown in FIG. 2) is 60 μm or more. The average length in the thickness direction of the non-woven fabric is measured by the following method. That is, a cross section along the thickness direction of the non-woven fabric to be measured is observed at a magnification of 200 times using a scanning electron microscope (JCM-5100 manufactured by Nippon Denshi Co., Ltd.), and in the enlarged image, the thickness direction of the non-woven fabric is observed. All large resin lumps (resin lumps having a length of 10 μm or more in the thickness direction of the non-woven fabric and a part protruding from the surface of the non-woven fabric) existing in a region extending over 10 mm in the direction orthogonal to (the surface direction of the non-woven fabric). The maximum length in the non-woven fabric thickness direction is measured, and the average value of these measured values is taken as the average length in the non-woven fabric thickness direction of the large resin block.

In order to obtain a non-woven fabric having a rough feel, it is necessary that a large number of protrusions are formed on the surface of the non-woven fabric. Here, the fingerprint of a human finger is composed of unevenness composed of convex portions (ridge lines) and concave portions (valley lines) on the surface of the finger, and the height of the convex portions is about 50 μm. Further, when the surface of the object in contact with the finger surface has irregularities, the existence of the irregularities is strongly recognized due to the difference in the degree of finger deformation at the time of contact between the convex portions and the concave portions constituting the unevenness. ..

Based on the above findings, the present inventors have obtained the length of the large resin mass contained in the non-woven fabric in the thickness direction of the non-woven fabric in order to obtain a non-woven fabric having a unique texture and a high-class feel (reference numerals in FIG. 2). It was concluded that the length indicated by L0) needs to exceed the height of the convex portion of the fingerprint on the surface of a human finger of 50 μm, and the average length of a plurality of large resin lumps contained in the non-woven fabric in the thickness direction of the non-woven fabric is 60 μm or more. I came up with the need to be. However, from the viewpoint of maintaining a preferable feel and securely fixing the large resin block to the non-woven fabric, the average length of the large resin block in the non-woven fabric thickness direction is preferably 65 μm or more, preferably 160 μm or less, and further. It is preferably 100 μm or less. The average length of the resin lump (large resin lump) in the thickness direction of the non-woven fabric can be adjusted by adjusting the flow rate of hot air blown onto the molten resin in the method for producing a non-woven fabric of the present invention described later.

From the viewpoint of more reliably realizing a high-class and unique rough feel, the number of large resin lumps per 1 cm ² unit area is preferably 1 or more, more preferably 50 or more, and The number is preferably 200 or less, more preferably 100 or less. Here, the reason why the unit area is set to 1 cm ² is that the area where a person's finger comes into contact with an object such as a non-woven fabric is usually about 1 cm ² . According to the method for producing a non-woven fabric of the present invention described later, the number of large resin lumps per 1 cm ² unit area can be set in the above range.

Further, in order to enhance the feel, it is preferable that the length of the large resin block contained in the non-woven fabric in the thickness direction of the non-woven fabric (the length indicated by reference numeral L0 in FIG. 2) is uniform. From this point of view, the standard deviation of the length distribution of the large resin mass in the thickness direction of the non-woven fabric is preferably 70 or less, more preferably 40 or less. According to the method for producing a non-woven fabric of the present invention described later, it is possible to set the standard deviation of the length distribution of the large resin block in the non-woven fabric thickness direction within the above range. The standard deviation is calculated using the STDEVP function of the computer software "Excel".

The basis weight of the nonwoven fabric of the present invention may be appropriately set according to the use of the nonwoven fabric and the like. When the non-woven fabric of the present invention is used as a constituent member of a worn article such as an absorbent article, it is preferably 1 g / m ² or more, more preferably 5 g / m ² or more, and preferably 50 g / m ² or less. It is preferably 30 g / m ² or less. By having a basis weight in this range, the non-woven fabric has sufficient strength, and even when it is used as a constituent member of the worn article, particularly a surface of the worn article that can come into contact with the wearer's skin. Inconveniences such as tearing are less likely to occur.

Next, the method for producing the nonwoven fabric of the present invention will be described based on the preferred embodiment thereof. 3 and 4 show a non-woven fabric manufacturing apparatus 10 used in the manufacturing method of this embodiment. In the manufacturing method of the present embodiment, the molten resin is discharged from the nozzle 16 through the flow path 15 and the molten resin is stretched by blowing hot air onto the discharged molten resin to form fibers 2. It has a step of accumulating 2 to form a non-woven fabric 1.

The manufacturing apparatus 10 manufactures the non-woven fabric 1 by the melt blown method, and as shown in FIG. 3, the extruder 11, the hopper 12 that supplies the raw material resin to the extruder 11, and the screw inside the extruder 11 ( A motor 13 for rotating (not shown) and a die (base) 14 for discharging the molten resin extruded by the screw from the extruder 11 are provided. As shown in FIG. 4, a flow path 15 of the molten resin provided with a nozzle 16 for discharging the molten resin is formed inside the die 14. A plurality of nozzles 16 are provided at the lower end of the die 14, and the plurality of nozzles 16 are intermittently arranged in a direction CD orthogonal to the longitudinal direction of the die 14 (conveying direction MD of the non-woven fabric 1), and each of the nozzles 16 is arranged along the vertical direction. Extends downward.

As shown in FIG. 4, the die 14 is provided with an annular air supply port 17 for blowing hot air to be blown onto the molten resin discharged from the nozzle 16. The air supply port 17 is located on both front and rear sides of the transport direction MD so as to sandwich a row of nozzles 16 (not shown) extending in the direction CD, and extends in parallel with the row of nozzles 16. Hot air is supplied from the blower 18 connected to the die 14.

Below the die 14, as shown in FIG. 3, a belt conveyor 19 as a collector for the fibers 2 is provided. The belt conveyor 19 collects and accumulates fibers 2 generated from the molten resin discharged from the nozzle 16 on the collection surface above the fibers 2 to form a non-woven fabric 1 (melt blown non-woven fabric), and in the direction indicated by the symbol MD. Transport.

In the manufacturing apparatus 10 having such a configuration, a raw material resin such as a thermoplastic resin is supplied from the hopper 12 to the extruder 11, melt-kneaded inside the extruder 11, and then supplied to the die 14. Inside the die 14, the molten resin supplied from the extruder 11 is supplied to the nozzle 16 via the flow path 15. Further, the outside air is heated in the blower 18, and the heated outside air is supplied from the blower 18 to the air supply port 17 as hot air. Then, at the same time that the molten resin is discharged from the nozzle 16, hot air is ejected from the air supply port 17 at a high speed, and the discharged molten resin is made extremely fine to form fibers 2. The fibers 2 generated here are accumulated on the collection surface of the belt conveyor 19 to form the non-woven fabric 1. The configuration of the manufacturing apparatus 10 described above is basically the same as that of the known melt blown type nonwoven fabric manufacturing apparatus.

As one of the main features of the manufacturing method of the present embodiment, gas or a gas generating substance that generates gas by heating is added to the molten resin before being discharged from the nozzle 16, so that bubbles are contained in the molten resin. There is a point of mixing. In the manufacturing apparatus 10, as shown in FIG. 3, an introduction pipe 20 communicating with the inside of the extruder 11 is provided in a portion (cylinder barrel) of the extruder 11 in which a screw (not shown) is built. By introducing the gas or the gas generating substance from the introduction pipe 20, the gas or the gas generating substance can be added to the molten resin existing inside the extruder 11.

By adding gas or a gas generating substance from the introduction pipe 20 to the molten resin before being discharged from the nozzle 16, the molten resin contains a large number of gas bubbles. When a gas-generating substance is added, it is heated and decomposed by being added to a high-temperature molten resin to generate gas. The molten resin containing bubbles has a form in which a plurality of bubbles are intermittently arranged in the extending direction of the flow path 15 in the flow path 15 of the die 14, and the molten resin exists between the bubbles, and the nozzle has such a form. It is discharged from 16. When the length of the molten resin sandwiched between the bubbles is sufficiently long, that is, one end of the molten resin (the rear end in the discharge direction) is located inside the die 14, the other end (the front end in the discharge direction). If can be located further below the hot air blowing position by the air supply port 17 (on the belt conveyor 19 side), the molten resin is normally ejected from the air supply port 17 immediately after being discharged from the nozzle 16. It is stretched and micronized to obtain fiber 2. On the other hand, when the length of the molten resin sandwiched between the bubbles is short, that is, when one end of the molten resin is located inside the die 14, the other end is above the hot air blowing position by the air supply port 17. When it is located on the die 14 side, the molten resin falls on the collection surface of the belt conveyor 19 without being sufficiently stretched by hot air, and adheres to the fibers 2 around the molten resin to form a resin mass 3. It becomes. However, even a molten resin having such a short length can be shredded by blowing hot air, even if it is not stretched, and can fall on the collecting surface of the belt conveyor 19. The above is a typical formation mechanism of the resin mass 3. In this way, the non-woven fabric 1 including the fiber 2 and the resin mass 3 made of the resin that adheres to the fiber 2 and forms the fiber 2 is manufactured. According to the manufacturing method of the present embodiment, the non-woven fabric 1 can be efficiently manufactured by using the existing non-woven fabric manufacturing equipment.

From the viewpoint of more reliably generating the resin mass 3, the amount of gas contained in 1 kg of the molten resin discharged from the nozzle 16 (the amount of gas directly added to the molten resin and the gas generating substance added to the molten resin). The total amount with the amount of gas generated from the above) is preferably 0.0001 mol or more, more preferably 0.005 mol or more, and preferably 0.1 mol or less, still more preferably 0.07 mol or less.
The amount of gas contained in 1 kg of the molten resin can be calculated as the amount of gas of 0.009 mol (200 ml at 1 atm) per 1 g of ADCA when azodicarbonamide (ADCA) is used as the gas generating substance (foaming agent). When the gas is directly fed into the molten resin, the amount of gas contained in 1 kg of the molten resin can be calculated from the feed amount.

The gas to be added to the molten resin is preferably a gas that is inert to the molten resin, and may be appropriately selected depending on the type of resin in the molten resin. When the above-mentioned thermoplastic resin is used as the raw material resin, specifically, when polypropylene is used, the usable gases are nitrogen, carbon monoxide, carbon dioxide, ammonia, butane, pentane, hexane, dichloroethane, and chlorofluorocarbon. , Steam can be exemplified.

Further, as the gas generating substance to be added to the molten resin, a substance capable of generating gas by adding to the molten resin can be used, and azodicarbonamide (ADCA) is used as a suitable gas generating substance (foaming agent). It can be exemplified. ADCA has a thermal decomposition temperature of 200 to 210 ° C., and the thermal decomposition generates nitrogen, carbon monoxide, and carbon dioxide, and also generates a trace amount of ammonia. When ADCA is used, polypropylene is preferably used as the raw material resin. The amount of ADCA added to the molten resin is preferably 0.0001 mol or more, more preferably 0.0005 mol or more, and preferably 0.0005 mol or more, from the viewpoint that the amount of gas contained in 1 kg of the molten resin discharged from the nozzle is within the above range. Is 0.1 mol or less, more preferably 0.07 mol or less.

Further, in the manufacturing method of the present embodiment, in addition to adding gas or a gas generating substance to the molten resin before being discharged from the nozzle 16, the pressure of the flow path 15 is further set to 2 MPa or more. The pressure of the flow path 15 is 2 MPa or more, preferably 3 MPa or more, and more preferably 4 MPa or more, from the viewpoint of uniformly distributing the bubbles generated in the molten resin by the addition of the gas or the gas generating substance. The upper limit of the pressure of the flow path 15 is not particularly limited from the viewpoint of improving the uniformity of bubbles in the molten resin, and may be appropriately set within a range that does not cause inconvenience such as equipment failure. The pressure of the flow path 15 is proportional to the extrusion pressure of the molten resin by a screw (not shown) in the extruder 11, and can be adjusted by adjusting the extrusion pressure of the molten resin.

The "passage pressure" in the present invention is used as an index of the pressure applied to the molten resin immediately before being discharged from the nozzle 16, as is clear from the significance of setting this in the specific range. Since it is meaningful, the measurement position is preferably a position as close as possible to the discharge hole at the tip of the nozzle 16, and is preferably at least the flow path 15 inside the die 14 provided with the nozzle 16. The pressure in the flow path can be measured according to a conventional method using a pressure sensor or the like.

When the flow rate of the hot air jetted from the air supply port 17 is large, the resin lump 3 is easily fragmented, which is effective in improving the feel of the non-woven fabric 1. From such a viewpoint, the flow rate of the hot air is preferably 400Nm ³ / h / m or more, more preferably 800Nm ³ / h / m or more. On the other hand, the flow rate of hot air is preferably 2000 Nm ³ / h or less, more preferably 2000 Nm ³ / h or less, from the viewpoint that the fibers immediately after spinning do not get entangled with each other, the texture of the non-woven fabric is made uniform, the strength is increased, and the trouble of tearing is less likely to occur. It is 1600 Nm ³ / h or less.

The non-woven fabric of the present invention produced as described above is suitable for applications that make use of its unique rough texture. The non-woven fabric of the present invention can be applied to, for example, disposable wear articles (disposable wear articles worn around the waist or inseam of the wearer when worn), and specifically, deployable disposable diapers, pants-type disposable napkins, and sanitary napkins. Suitable for absorbent articles such as sanitary napkins that have an absorber, as well as wearable articles that do not have an absorber, such as medical wear items such as surgical gowns, disposable underwear, and other wear items such as masks. is there. In such worn articles, a member having a surface that can come into contact with the wearer's skin is formed of the non-woven fabric of the present invention, and the large resin mass protrudes from the surface that can come into contact with the wearer's skin. It is possible to improve the wearing feeling of the article. Specifically, for example, the non-woven fabric of the present invention can be used as a liquid-permeable sheet (for example, a surface sheet) arranged at a position closer to the wearer's skin than the absorbent body in the absorbent article.

In addition, the non-woven fabric of the present invention has a high-class feeling that is not found in conventional non-woven fabrics due to its unique rough texture. Therefore, applications utilizing the high-class feeling, such as wrapping paper and interior wall materials of houses, etc. It is also suitable for.
Although the present invention has been described above, the present invention is not limited to the above-described embodiment, and can be appropriately modified without departing from the spirit of the present invention.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to such Examples.

[Examples 1 to 11 and Comparative Example 1]
Using the nonwoven fabric manufacturing apparatus having the same configuration as the manufacturing apparatus 10 shown in FIGS. 3 and 4, the melt-blown nonwoven fabric having a basis weight shown in Table 1 was produced under the conditions shown in Table 1 below. Polypropylene (PP) was used as the raw material resin. In Examples 1 to 11, addition of the ADCA to the molten resin was adopted as a method of mixing air bubbles into the molten resin before being discharged from the nozzle. In Comparative Example 1, air bubbles were not mixed into the molten resin.

[Reference example]
As paper satin finish has been applied, it was used that has been subjected to satin finish the Energy duodecimo Y th Prince F-Tech Co., Ltd. basis weight 190 g / m ^2. The satin finish was processed using the satin finish [Large] of Morikawa Co., Ltd. This paper was used as a reference example. The paper of this reference example has a convex portion having a size of 63 μm, and is said to have a high-class feeling with a unique rough touch. The size of the convex part of the paper was measured by the following method. The cross section of the paper was magnified 200 times using a scanning electron microscope (JCM-5100, manufactured by JEOL Ltd.), and the top of the convex portion and the concave portion were focused on the convex portion and the concave portion adjacent to the convex portion. Measure the distance from the bottom of the paper in a direction orthogonal to the plane direction of the paper. Such distances are measured for any 20 convex portions and their adjacent concave portions, and the average value thereof is taken as the convex portion of the paper.

For the non-woven fabrics of each Example and Comparative Example, the average length of the large resin mass in the non-woven fabric thickness direction was measured by the above method, and the touch was evaluated by the following method. The results are shown in Table 1 below.

<Evaluation method for touch>
The surface of the evaluation target (nonwoven fabric or paper) was touched by three adult male and female panelists with their fingertips, and the feeling of touch was evaluated on a scale of 5 points. Specifically, each of the reference example papers was given a maximum of 5 points (a unique rough feel and a high-class feel), and the non-woven fabric of Comparative Example 1 was given a 0 point (poor unique rough touch). We asked the panelists to score the non-woven fabrics of each example. The score to be evaluated is the total score of each panelist, and the maximum score is 15. The higher the score, the closer the tactile sensation to that of the reference example paper, that is, the more luxurious the tactile sensation with a unique rough texture.

1 Non-woven fabric 1S Non-woven fabric surface 2 Fiber 3 Resin lump 30 Large resin lump 10 Non-woven fabric manufacturing equipment 11 Extruder 12 Hopper 13 Motor 14 Die 15 Flow path 16 Nozzle 17 Air supply port 18 Blower 19 Belt conveyor 20 Introductory pipe

Claims (3)

Member having a surface that may contact the skin of the wearer, is formed by a nonwoven fabric, the nonwoven fabric comprises a fiber and a resin mass to stick to the fibers, the resin mass, the resin for forming the fibers Is a worn item, including
There are a plurality of large resin lumps on the non-woven fabric,
The large resin lump has a length of 10 μm or more in the thickness direction of the non-woven fabric and a part of the large resin lump protrudes from the surface of the non-woven fabric.
The average length of the plurality of large resin lumps in the non-woven fabric thickness direction is 60 μm or more.
A worn article in which the large resin mass protrudes from a surface that can come into contact with the wearer's skin. The worn article according to claim 1 , wherein one or more large resin lumps are present in the non-woven fabric per 1 cm ² unit area. The standard deviation of the length distribution in the nonwoven thickness direction of the large resin mass is 50 less wearing article according to claim 1 or 2.

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