JP7125838B2 - absorbent article - Google Patents

Description

TECHNICAL FIELD The present invention relates to absorbent articles such as printed incontinence pads, light incontinence pads, tape-fastened disposable diapers, and the like.

Currently, absorbent articles such as disposable diapers for infants and adults are widely used. These absorbent articles are constructed to include a liquid-permeable topsheet, a liquid-impermeable backsheet, and an absorbent body disposed between the topsheet and the backsheet. The liquid-permeable top sheet is mainly composed of a nonwoven fabric, and the liquid-impermeable back sheet is composed of a plastic film such as polyethylene.

A suitable mounting position for preventing leakage differs depending on the wearer's sex, body type, posture, and the like. In addition, there is a problem that urine leakage occurs if it is not attached at a suitable position. Therefore, in order to make it easy to understand the mounting position, notations on specifications such as the size and front and back of the absorbent article are printed.

The printing method is appropriately selected according to the surface properties of the member to be printed, but the printing accuracy may be limited depending on the printing method. For example, when the material to be printed is a plastic film or paper, flexographic printing or gravure printing can be used, and a certain degree of printing accuracy can be obtained. Here, flexographic printing and gravure printing are methods in which a printing plate roll and a member to be printed are in contact with each other for printing.

In this regard, various non-woven fabrics and the like, which are generally used for top sheets, three-dimensional gathered sheets, individual packaging sheets and the like, do not have smooth surfaces as compared to plastic films, paper and the like. Therefore, when printing is performed on these by the above-mentioned contact printing method, the printing accuracy is deteriorated due to the presence of large and small irregularities on the surface, and the cosmetic properties such as appearance and visibility are impaired. There is a problem. On the other hand, in recent years, consumers have increasingly demanded the visibility of printed parts. Therefore, when printing on various non-woven fabrics, it is necessary to take measures such as limiting the printing speed or increasing the size of patterns and characters.

On the other hand, when a pre-printed nonwoven fabric roll is used in the production of absorbent articles, it takes time and is difficult to align the printed part in the longitudinal direction of the absorbent article when the nonwoven fabric roll is set in the production apparatus. In addition, the position of the nonwoven fabric may be shifted during manufacturing, requiring position adjustment.

Patent Document 1 discloses forming front and rear labeling layers directly on the surface of a top sheet that constitutes the inner surface of an absorbent article such as a sanitary napkin.

In Patent Document 2, in an absorbent article such as a sanitary napkin, from both sides of a back sheet wound on the surface side from both sides in the width direction of the absorbent article, a linear longitudinal position It discloses that alignment marks are printed at predetermined intervals along the longitudinal direction.

JP-A-2002-360620 Japanese Patent No. 4392857

However, the front and back notation layer disclosed in Patent Document 1 does not indicate the approximate wearing position, but only indicates the wearing direction, so it is said that the wearer or caregiver cannot recognize the wearing position of the absorbent article well. There's a problem. Further, since the front and rear writing layers are formed directly on the top sheet, there is also the problem that the absorption performance of the top sheet is hindered by the front and rear writing layers.

In addition, since the alignment marks disclosed in Patent Document 2 are formed on both sides in the width direction of the absorbent article, when the absorbent article is laid under the wearer's buttocks, both legs are in the way. As a result, there is a risk that the alignment mark cannot be recognized well. Furthermore, no specific method for printing the alignment mark is disclosed. Therefore, in the case of printing alignment marks on a surface sheet having an uneven and hydrophilic surface of a printed material by flexographic printing or gravure printing, an absorbent article with good visibility is manufactured with good operability. I have a problem with that.

Therefore, the present invention provides an absorbent article which has excellent visibility, is printed without impairing the absorbent performance, makes it easy to understand the wearing position in the front-rear direction of the body, has good productivity, and is low in cost. With the goal.

The inventors of the present invention conducted extensive research in view of the above problems. As a result, the body side surface or the clothing side surface of the top sheet or the liquid-diffusing sheet has a plurality of graduation lines printed with dot-like hot-melt ink at predetermined intervals along the longitudinal direction. The inventors have found that the above problems can be solved by making the dots of the hot-melt ink printed in a predetermined configuration, and have completed the present invention.

(1) A first aspect of the present invention is an absorbent article having a liquid-permeable topsheet, a liquid-impermeable backsheet, and an absorbent body disposed between the topsheet and the backsheet. The top sheet has a plurality of scale lines printed with dot-like hot-melt ink at predetermined intervals along the longitudinal direction on the body-side surface or the garment-side surface, and printed on the top sheet. The average area of each dot of the hot-melt ink printed on the top sheet is 1000 μm ² or more and 2000 μm ² or less, and the dot spacing of each dot of the hot-melt ink printed on the top sheet is 50 μm or more and 300 μm or less. , in the area printed with the hot melt ink on the top sheet, the area ratio occupied by the dots of the hot melt ink is 12% or less, and the hot melt ink is printed by inkjet printing, The absorbent article is characterized in that the inkjet printing is in-line printing incorporated in a production line for the absorbent article.
(2) A second aspect of the present invention is an absorbent article having a liquid-permeable topsheet, a liquid-impermeable backsheet, and an absorbent body disposed between the topsheet and the backsheet. The absorbent article further has a liquid-diffusing sheet disposed between the top sheet and the absorbent body, and the liquid-diffusing sheet extends longitudinally on the body-side surface or the garment-side surface. It has a plurality of scale lines printed with dot-like hot-melt ink at predetermined intervals along, the plurality of scale lines are visible through the top sheet, and are printed on the liquid-diffusing sheet. The average area of each dot of the hot melt ink is 1000 μm ² or more and 2000 μm ² or less, and the dot spacing of each dot of the hot melt ink printed on the liquid diffusion sheet is 50 μm or more and 300 μm or less. , the area ratio of the hot melt ink in the area printed with the hot melt ink on the liquid diffusion sheet is 12% or less, and the hot melt ink is printed by inkjet printing, The absorbent article is characterized in that the inkjet printing is in-line printing incorporated in a production line for the absorbent article.
(3) In the absorbent article according to (1), the scale lines may be printed on an embossed topsheet.
(4) In the absorbent article according to (1), the top sheet is coated with dot-like hot-melt ink on the body-side surface or the garment-side surface along the longitudinal direction at substantially the center position in the width direction. It may also have a printed centerline.
(5) In the absorbent article according to (2), the liquid-diffusing sheet is a nonwoven fabric,
The basis weight of the liquid-diffusing sheet may be 15 g/m ² or more and 40 g/m ² or less.
(6) In the absorbent article according to (2), the liquid-diffusing sheet is provided on the body-side surface or the clothing-side surface along the longitudinal direction and at substantially the center position in the width direction. It may further comprise an ink printed centerline, said centerline being visible through said topsheet.
(7) In the absorbent article according to (1) or (2), the absorbent article further has three-dimensional gathers along the longitudinal direction, and additional information may be printed on the three-dimensional gathers. good.
(8) In the absorbent article according to any one of (1) to (7), the scale line is arranged at a substantially central position in the width direction, and is , may be formed to a dimension of 40% or more.
(9) In the absorbent article according to any one of (1) to (8), the print line speed in the inkjet printing may be 100 m/min or more.
(10) In the absorbent article according to any one of (1) to (9), the hot-melt ink has a viscosity of 0.1 Pa.s at 120°C. It may have a melt viscosity of s or less.
(11) In the absorbent article according to any one of (1) to (10), the top sheet is a nonwoven fabric, and the basis weight of the top sheet is 15 g/m ² or more and 40 g/m ² or less. may be

The absorbent article of the present invention has a plurality of graduation lines printed with dot-like hot-melt ink at predetermined intervals along the longitudinal direction on the body side surface or the clothing side surface of the top sheet or the liquid-diffusing sheet. The average area of each dot of hot melt ink printed on the top sheet is 1000 μm ² or more and 2000 μm ² or less, and the dot spacing of each dot of hot melt ink printed on the top sheet is 50 μm or more and 300 μm or less. and the area ratio occupied by hot melt ink dots in the area printed with hot melt ink on the top sheet is 12% or less, and the hot melt ink is printed by inkjet printing, and inkjet printing is , in-line printing integrated into the manufacturing line of absorbent articles. As a result, it is possible to provide an absorbent article which has excellent visibility, is printed without impairing the absorption performance, makes it easy to understand the wearing position in the front-rear direction of the body, has good productivity, and is low in cost. Moreover, since inkjet printing is inline printing, it is possible to print at an appropriate position in the longitudinal direction of the absorbent article.

FIG. 2 is a plan view of the absorbent article of the present invention, viewed from the body-side surface of the absorbent article.

Hereinafter, the absorbent article 1 according to the embodiment of the present invention will be described in detail, but these are listed for the purpose of illustration and do not limit the present invention. In addition, the same code|symbol is attached|subjected to the same element through the whole description of embodiment.

<Absorbent article>
The absorbent article 1 according to the embodiment of the present invention may be an absorbent article 1 such as an incontinence pad, a light incontinence pad, a light incontinence liner, a sanitary napkin, and a tape-fastened paper diaper. The absorbent article 1 includes a liquid-permeable top sheet 10 arranged on the body-side surface, a liquid-impermeable back sheet facing the top sheet 10 and arranged on the clothing-side surface, the top sheet 10 and the back. and an absorbent body 11 arranged between the sheets, whereby the absorbent body 11 is sandwiched between the top sheet 10 and the back sheet. The top sheet 10, the back sheet, and the absorbent body 11 may be bonded to each other with an adhesive, heat-sealing, or the like.

In the description of this specification, the longitudinal direction is the direction across the front and back of the wearer when the absorbent article 1 is worn. Moreover, the width direction is a direction that is horizontal or orthogonal to the longitudinal direction. In this specification, the body-side surface refers to the surface that contacts the wearer's skin when the absorbent article 1 is worn or the surface that contacts the wearer's skin when the absorbent article 1 is worn. The side surface is the surface opposite to the body side surface, and is the surface that contacts the wearer's clothing when the absorbent article 1 is worn or the side that contacts the wearer's clothing when the absorbent article 1 is worn. point to the surface.

As shown in FIG. 1, in the embodiment of the present invention, the absorbent article 1 has a substantially gourd-like shape in plan view, but is not limited to this. There may be.

[Top sheet]
The top sheet 10 used in the absorbent article 1 according to the embodiment of the present invention allows bodily fluids to pass quickly toward the absorbent body 11, and is arranged to face the back sheet with the absorbent body 11 interposed therebetween. be. Since the top sheet 10 is a sheet that comes into contact with the skin, it is preferably a hydrophilic non-woven fabric that has a soft feel and does not irritate the skin. Hydrophilic nonwoven fabrics include thermal bonded nonwoven fabrics such as hydrophilic air-through nonwoven fabrics, spunlace nonwoven fabrics, spunbond nonwoven fabrics, and open polyethylene films using synthetic fibers such as polypropylene and polyethylene, recycled fibers such as rayon, and natural fibers such as cotton. and foamed films such as urethane foam, etc., and from the viewpoint of breathability and feel when worn, it is preferable to use a thermal bonded nonwoven fabric such as a hydrophilic air-through nonwoven fabric or a spunbond nonwoven fabric.

The basis weight of the top sheet 10 is preferably 15 g/m ² or more and 40 g/m ² or less in terms of workability and strength. In addition, lotions, antioxidants, anti-inflammatory components, pH adjusters, antibacterial agents, moisturizing agents, etc. may be applied to the top sheet 10 in order to reduce irritation to the skin.

[Back sheet]
The backsheet used in the absorbent article 1 according to the embodiment of the present invention is a sheet material having liquid impermeability, and is arranged to face the topsheet 10 with the absorbent body 11 interposed therebetween. As the back sheet, a sheet material using a thin plastic sheet such as a polyethylene sheet or a polyethylene-laminated nonwoven fabric can be used. In addition, it may have moisture permeability to prevent stuffiness.

The basis weight of the backsheet is preferably 15 g/m ² or more and 60 g/m ² or less from the viewpoint of workability and strength.

[Absorber]
The absorbent body 11 used in the absorbent article 1 according to the embodiment of the present invention contains absorbent fibers as a base material and a super absorbent polymer (hereinafter also referred to as SAP). Absorbent fibers are not particularly limited as long as they are generally used in absorbent articles 1 such as sanitary napkins, diapers, and incontinence pads. Examples include fluff pulp, cotton, rayon, acetate fibers, tissues, and absorbent paper. , hydrophilic nonwoven fabric, and the like. Among these, fluff pulp is preferably used from the viewpoint of absorbability. Examples of fluff pulp include wood pulp (for example, bleached softwood kraft pulp (N-BKP) such as southern pine and Douglas fir), synthetic fiber, polymer fiber, non-wood pulp, etc., which are defibrated into cotton. can be done. The absorbent fibers of the absorbent body 11 preferably have a basis weight of 400 g/m ² or more and 800 g/m ² or less so as not to impair the absorption performance and the touch.

The SAP used for the absorbent body 11 is not particularly limited as long as it can absorb body fluids and prevent backflow, and may be sodium polyacrylate, polyaspartate, or (starch-acrylic acid) graft copolymer. Those formed from materials such as coalescence, (acrylic acid-vinyl alcohol) copolymers, (isobutylene-maleic anhydride) copolymers and saponified products thereof can be used. Among these, sodium polyacrylate copolymers are preferable from the viewpoint of absorption amount per mass. The amount of SAP in the absorbent body 11 is preferably grammage of 50 g/m ² or more and 700 g/m ² or less so as not to impair the absorption performance and feel, and the content should be 15 mass % or more and 60 mass % or less. is preferred.

In the absorbent body 11, the absorbent fibers and SAP are preferably in the form of a laminated mat formed by mixing SAP particles in the absorbent fibers. For the purpose of preventing leakage of SAP particles and stabilizing the shape of the absorbent body 11, it is preferable to wrap the absorbent body 11 with a carrier sheet. The base material of the carrier sheet may be any material as long as it is hydrophilic, and examples thereof include hydrophilic nonwoven fabrics such as tissues, absorbent paper, and air-laid nonwoven fabrics. When a plurality of carrier sheets are provided, the base material of the carrier sheets may be the same or different, and the method of wrapping the absorber 11 with the carrier sheets is not particularly limited.

The basis weight of the absorbent body 11 is preferably 400 g/m ² or more and 1500 g/m ² or less. By setting the basis weight of the absorbent body 11 within such a range, it is possible to achieve excellent absorbency and effectively prevent leakage of bodily fluids. Moreover, the absorbent body 11 may be formed by laminating an upper layer absorbent body and a lower layer absorbent body. In this case, the lengthwise and widthwise dimensions of the upper absorbent body and the lower absorbent body may be such that the upper absorbent body is larger than the lower absorbent body, and the upper absorbent body is the same as the lower absorbent body. and the dimension of the upper absorbent body may be smaller than the dimension of the lower absorbent body.

The absorbent body 11 may be single-layered or multi-layered, and may be provided with a slit portion where there are no absorbent fibers and no superabsorbent polymer.

[Liquid diffusion sheet]
In the absorbent article 1 according to the embodiment of the present invention, a liquid diffusion sheet may be provided between the top sheet 10 and the absorbent body 11 in order to promote diffusion of body fluids to the upper surface of the absorbent body 11 . Examples of liquid-diffusing sheets include nonwoven fabrics such as air-through nonwoven fabrics, point-bonded nonwoven fabrics, spunbonded nonwoven fabrics, meltblown nonwoven fabrics, and composite nonwoven fabrics obtained by laminating spunbond/meltblown and spunbond/meltblown/spunbond layers.

The basis weight of the liquid-diffusing sheet is preferably 15 g/m ² or more and 40 g/m ² or less. Although the shape of the liquid-diffusing sheet is not particularly limited, it preferably has a shape that can completely cover the surface of the absorbent body 11 so that body fluids such as urine can diffuse all over the absorbent body 11 .

[Three-dimensional gather]
On the body side surface of the absorbent article 1 according to the embodiment of the present invention, an elastic member for three-dimensional gathers and a three-dimensional elastic member are provided along the longitudinal direction of the absorbent article 1 in order to prevent lateral leakage of body fluid excreted by the wearer. A pair of three-dimensional gathers 12 having gather sheets may be provided. The three-dimensional gathers 12 are preferably fixed to the backsheet at the widthwise end (fixed end) of the absorbent article 1, and the free end side is preferably folded in half at the end. It is preferable that the three-dimensional gathers elastic member is sandwiched between the two-folded three-dimensional gathers sheets on the free end side. As a result, the three-dimensional gathers 12 can stand upright and can be deformed according to the body shape of the wearer.

As the three-dimensional gather elastic member, for example, a polyurethane thread, a band-shaped polyurethane film, a synthetic rubber, a thread-shaped or band-shaped natural rubber, or the like can be used, and a thread-shaped, cord-shaped, or flat-shaped member can be used as appropriate. . As the three-dimensional gathered sheet, a water-repellent or liquid-impermeable nonwoven fabric made of hydrophobic fibers, such as a spunbond nonwoven fabric, a meltblown nonwoven fabric, or a spunbond/meltblown/spunbond laminated composite nonwoven fabric is used. be done. The thickness of the three-dimensional gather elastic member is preferably 1240 dtex or less.

The basis weight of the three-dimensional gather sheet is preferably 10 g/m ² or more and 40 g/m ² or less.

[Packaging sheet]
The absorbent article 1 according to the embodiment of the present invention may have a packaging sheet for packaging the absorbent article 1 . As the packaging sheet, for example, paper, resin films such as polyethylene, polypropylene, polyester, polyvinyl alcohol, etc., spunbond nonwoven fabric, meltblown nonwoven fabric, spunbond/meltblown/spunbond laminated composite nonwoven fabric, or composite materials thereof are used. be able to. In addition, the inner side of the packaging sheet that is in contact with the absorbent article 1 can be subjected to peeling treatment with silicon or the like.

Although the basis weight of the packaging sheet is not particularly limited, it is preferably 15 g/m ² or more and 30 g/m ² or less, and 20 g/m ² or more and 25 g/m ² or less from the viewpoint of strength and workability. is more preferred.

[Hot melt ink printing]
As shown in FIG. 1, the top sheet 10 used in the absorbent article 1 according to the embodiment of the present invention has dot-like dots formed on the body side surface or the clothing side surface at predetermined intervals (equal intervals) along the longitudinal direction. has a plurality of scale lines 13 printed with hot melt ink and numerical values corresponding to each scale line 13, and a plurality of scale lines 13 and numerical values corresponding to each scale line 13 are printed on the body side surface of the top sheet 10 It is preferable to have This makes it possible to easily perform alignment in the longitudinal direction and to easily recognize the mounting direction.

In addition, from the viewpoint of recognizing the scale lines 13 easily, the scale lines 13 are arranged at substantially the center position in the width direction and substantially at the center position in the longitudinal direction with respect to the longitudinal dimension of the absorbent article 1. It is preferable to form the dimension of 40% or more.

Furthermore, in the embodiment of the present invention, the scale lines 13 are printed on the surface of the top sheet 10, which is a flat surface. It may be printed on a topsheet that is not flat.

The top sheet 10 has a blue center line printed with dot-like hot-melt ink on the body-side surface or the garment-side surface so as to extend along the longitudinal direction at a substantially central position in the width direction. 14 and preferably has a centerline 14 on the body facing surface of the topsheet 10 . This makes it possible to easily perform not only alignment in the longitudinal direction but also alignment in the width direction.

The average area of each dot of hot-melt ink printed on the top sheet 10 is 1000 μm ² or more and 2000 μm ² or less, preferably 1100 μm ² or more and 1700 μm ² or less. The dot spacing between dots of hot-melt ink printed on the top sheet 10 is 50 μm or more and 300 μm or less, preferably 80 μm or more and 270 μm or less. The dot spacing between dots of hot-melt ink printed on the top sheet 10 is preferably the dot spacing in the feed direction. In addition, the area ratio of hot-melt ink dots in the area printed with hot-melt ink on the top sheet 10 is 12% or less, preferably 9% or less. Also, the average dot spacing between dots of the hot-melt ink printed on the top sheet 10 is preferably 90 μm or more and 280 μm or less, more preferably 100 μm or more and 270 μm or less.

By printing dots of hot-melt ink as described above, the absorbent article 1 having fine printing with high variability in multiple colors can be obtained by fine dots on the surface of the top sheet 10, and the visibility is improved. An excellent absorbent article 1 can be obtained. In addition, since the fine dots of the hot-melt ink adhere along the three-dimensional structure of the top sheet 10, the hot-melt ink does not block the surface of the top sheet 10, and the influence on the absorption performance of the absorbent article 1 is reduced. Thus, the absorbent article 1 can be provided with a print that does not impair the absorbent performance of the absorbent article 1 .

The hot-melt ink used for the absorbent article 1 according to the embodiment of the present invention is printed by inkjet printing. As a result, the print design can be easily changed by changing the electronic data, so that it is possible to eliminate the need for plate switching work. In addition, unlike the contact printing method such as flexographic printing, the non-contact printing method allows positional deviation of the plurality of scale lines 13 and the center line 14 without being influenced by the surface properties such as the basis weight of the object to be printed. It is possible to print without

The print line speed in inkjet printing is 100 m/min or more, preferably 200 m/min or more, and may be 280 m/min or less.

Ink jet printing is in-line printing incorporated in the production line of the absorbent article 1 . This enables high-speed production of the absorbent article 1 . For example, the non-woven fabric sheet to be the top sheet 10 is conveyed to an inkjet printer, and the non-woven fabric sheet to be the top sheet 10 is moved in the feed direction (machine direction or (machine direction or CD direction) perpendicular to the machine direction (MD direction), hot-melt ink is heated to a predetermined temperature, and the top sheet 10 of the non-woven fabric sheet, which is the wearer's skin contact surface, is scanned. A plurality of graduation lines 13 and a center line 14 are printed with hot-melt ink on the side surface or the clothing side surface which is the wearer's clothing contact surface. The inkjet printing apparatus is provided on a line for manufacturing the absorbent article 1 having the top sheet 10, the back sheet, and the absorbent body 11 disposed between the top sheet 10 and the back sheet. good too. Hot-melt ink can be cooled even at room temperature, but a cooling step may be provided to cool the absorbent article 1 after inkjet printing with a cooling roll, a blower, or the like. Furthermore, after cutting the absorbent article 1, the positional deviation of the scale line 13 and the center line 14 is detected by a defect detection device or the like, and based on the detected positional deviation of the scale line 13 and the center line 14, the scale line 13 and the center line 14 are detected. A print timing adjustment mechanism for adjusting the print timing of the center line 14 may be provided.

The hot-melt ink ejection method is not particularly limited, and a thermal method, a piezo method, or the like can be used.

Hot-melt ink has a viscosity of 0.1 Pa.s at 120°C. It preferably has a melt viscosity of 0.06 Pa.s or less. More preferably, it has a melt viscosity of s or less. As a result, the absorbent article 1 having excellent visibility, printing that does not impair the absorbent performance, high productivity, and low cost can be obtained.

The hot-melt ink is not particularly limited as long as it satisfies the melt viscosity described above. Thermoplastic resins include polyolefins such as polyethylene, mixtures thereof, polyamides, polyesters, polyesteramides, polyvinyl alcohols, cellulose esters, polyvinyl Pyridine, polyether, polyethylene, ethylene-vinyl acetate copolymer, copolyester, olefinic block copolymer rubber, polystyrene-acrylic copolymer, terpene resin, rosin fluid, phenolic resin, coumarone-indene resin, and the like can be used. Examples of these hot-melt inks include trade name: MDL5800 (manufacturer: EDM Co., Ltd.). The mass ratio of the binder in the hot-melt ink is preferably 20% or more and 50% or less, more preferably 30% or more and 40% or less.

Moreover, these hot-melt inks may contain additives such as waxes and oils in order to improve fluidity and the like. For example, polyalkylene waxes (polyethylene wax, polypropylene wax, etc.), Fischer-Tropsch wax, linear primary alcohols, microcrystalline waxes, fatty acids, carnauba wax, candelilla wax, stearamide, paraffin wax and montan wax, ethoxylation Long chain alcohols and the like can be used. These waxes may be used alone or in combination. The mass ratio of the additive in the hot-melt ink is preferably 40% or more and 70% or less, more preferably 50% or more and 60% or less.

Moreover, these hot-melt inks may contain inorganic pigments, organic pigments or dyes, and there is no particular limitation as long as they are commonly used in hot-melt inks. For example, inorganic pigments that can be used include titanium dioxide (white), carbon black (black), iron oxide (red, yellow, brown), chromium oxide (green), ferric ammonium ferrocyanide (blue), and the like. can. Further, for example, diarylide yellow (pigment yellow), phthalocyanine blue (pigment blue), red lake (pigment red) and the like can be used as organic pigments. The mass ratio of the pigment or dye in the hot-melt ink is preferably 0.1% or more and 20% or less, more preferably 0.5% or more and 10% or less.

In addition to binders, additives and pigments or dyes, these hot melt inks contain plasticizers, extenders, thickeners, defoamers, wetting agents or surfactants, antioxidants, and the like. may

When these hot-melt inks are used for inkjet printing, it is preferable to include a step of setting the temperature of the hot-melt ink to 60° C. or higher and 150° C. or lower, more preferably 70° C. or higher and 120° C. or lower. preferable.

In addition, the liquid-diffusing sheet has a plurality of scale lines printed with dot-like hot-melt ink at predetermined intervals along the longitudinal direction on the body-side surface or the clothing-side surface, and numerical values corresponding to each scale line 13. and preferably have a plurality of scale lines 13 and numerical values corresponding to each scale line 13 on the body-side surface of the liquid-diffusing sheet. A plurality of graduation lines 13 printed on the surface of the liquid-diffusing sheet and numerical values corresponding to each graduation line 13 are preferably visible through the top sheet 10 .

Furthermore, the liquid-diffusing sheet has a central line 14 printed with dot-like hot-melt ink so as to extend along the longitudinal direction on the body-side surface or the clothing-side surface at approximately the center position in the width direction. and a center line 14 on the body-side surface of the liquid-diffusing sheet. The center line 14 printed on the surface of the liquid-diffusing sheet is preferably visible through the top sheet 10 .

The dot-shaped hot-melt ink printed on the liquid-diffusing sheet is preferably the same as the dot-shaped hot-melt ink printed on the top sheet 10 described above. It is preferable to use those used in the top sheet 10 described above.

Also, the solid gathers 12 preferably have additional information on one side or the other side along the longitudinal direction. Additional information may include absorption amount, front-to-back direction, decoration, and the like. For example, when the elastic body of the three-dimensional gathers, the nonwoven fabric and the top sheet are the same white color, it may be difficult to identify the position of the three-dimensional gathers. By printing the three-dimensional gathers with high visibility, the absorbent article 1 can be attached so that the three-dimensional gathers are positioned appropriately on the wearer, and urine leakage and the like can be reliably prevented. In addition, in the case of the three-dimensional gathers 12 having an inner surface that forms an inner surface by folding the free end side of the three-dimensional gathers sheet in two at the end portion and is folded back to form an inner surface, and an outer surface that forms an outer surface by folding back, The volume gathers 12 may have additional information printed on the inner or outer surface.

The dot-shaped hot-melt ink printed on the three-dimensional gathers 12 is preferably the same as the dot-shaped hot-melt ink printed on the top sheet 10 described above. It is preferable to use the one used in the top sheet 10 of No.

Further, additional information such as size, absorption amount, product name, etc. may be printed on one side or the other side of the packaging sheet with dots of hot-melt ink. The dot-shaped hot-melt ink printed on the packaging sheet is preferably the same as the dot-shaped hot-melt ink printed on the top sheet 10 described above. It is preferred to use those used in 10.

[Method for manufacturing absorbent article]
A manufacturing method of the absorbent article 1 is not particularly limited, and a conventionally known method can be adopted. For example, hot-melt ink is printed on the body-side surface or clothing-side surface of the topsheet 10, the liquid-diffusing sheet and the three-dimensional gathers 12 are placed on the topsheet 10, and then the absorber 11 is placed on the topsheet 10 and the backsheet. It can be manufactured by sandwiching between and fixing the top sheet 10 and the back sheet over a part or the entire circumference using a hot melt adhesive, heat embossing, ultrasonic embossing, high frequency embossing, etc. . Alternatively, for example, the liquid-diffusing sheet and the three-dimensional gathers 12 are placed on the top sheet 10 in advance, and then the absorbent body 11 is sandwiched between the top sheet 10 and the back sheet, and the top sheet 10 and the back sheet are partially separated. Alternatively, the top sheet 10 can be manufactured by fixing the entire circumference using a hot-melt adhesive, heat embossing, ultrasonic embossing, high-frequency embossing, or the like, and applying hot-melt ink to the top sheet 10 .

Although the present invention has been described using the embodiments, it goes without saying that the technical scope of the present invention is not limited to the scope of the invention described in the above embodiments. It will be clear to those skilled in the art that improvements are possible. In addition, it is clear from the description of the scope of the claims that forms with such modifications or improvements can also be included in the technical scope of the present invention.

Examples and comparative examples will be described in detail below.

[Example 1]
In Example 1, a hot-melt ink was printed by inkjet printing on an air-through nonwoven fabric that can be used for a top sheet of an absorbent article, a liquid-diffusing sheet, and the like. Here, what is printed is a plurality of red scale lines 13, numerical values corresponding to each scale line 13, and a blue center line 14, as shown in FIG. In addition, the predetermined interval of each scale line 13 is 10 cm. Then, the incontinence absorbent pad, which is such an absorbent article, was set on the tape-fastened paper diaper.

[Example 2]
In Example 2, a hot-melt ink was printed by inkjet printing on an air-through nonwoven fabric that can be used for a top sheet of an absorbent article, a liquid-diffusing sheet, and the like. Here, the printed items are a plurality of red scale lines, numerical values corresponding to each scale line, and a blue center line. These scale lines are also printed on the three-dimensional gather. Then, the incontinence absorbent pad, which is such an absorbent article, was set on the tape-fastened paper diaper.

[Comparative Example 1]
In Comparative Example 1, hot-melt ink was not printed by inkjet printing on the air-through nonwoven fabric that can be used for the top sheet of absorbent articles, the liquid-diffusing sheet, and the like. Then, the incontinence absorbent pad, which is such an absorbent article, was set on the tape-fastened paper diaper.

15 persons with no nursing care experience were instructed to attach tape-fastened paper diapers set with incontinence pads, which are absorbent articles of Examples and Comparative Examples, to dummy dolls to confirm the appropriateness of attachment positions. In Examples 1 and 2, scale lines are printed on the air-through nonwoven fabric used for the top sheet, liquid diffusion sheet, etc., so there is no problem with regard to the mounting position, and most people can wear it without changing. did it. On the other hand, in Comparative Example 1, since scale lines were not printed on the air-through nonwoven fabric used for the top sheet, liquid diffusion sheet, etc., it was difficult to understand the attachment position, and many people changed the attachment several times.

After wearing the tape-fastened paper diaper, 150 ml of 0.9% physiological saline was poured twice, and the results were observed. It was confirmed that there was no difference in the transfer and absorption performance, and that they were good. In addition, in Example 2, in which scale lines are printed on the three-dimensional gathers, the three-dimensional gathers are attached to the body so that the longitudinal positions of the three-dimensional gathers are aligned. I was able to

1 Absorbent Article 10 Top Sheet 11 Absorber 12 Solid Gather 13 Scale Line 14 Center Line

Claims (8)

An absorbent article comprising a liquid-permeable topsheet, a liquid-impermeable backsheet, and an absorbent body disposed between the topsheet and the backsheet,
The absorbent article has three-dimensional gathers along the longitudinal direction,
The top sheet includes a plurality of red scale lines printed with dot-like hot-melt ink at predetermined intervals along the longitudinal direction on the body-side surface or the clothing-side surface, and numerical values corresponding to each of the scale lines. has
The top sheet further has a blue center line printed with dot-like hot-melt ink along the longitudinal direction on the body-side surface or the clothing-side surface at a substantially central position in the width direction,
Additional information on any of the scale lines, absorption amount, front-back direction, and decoration is printed on the three-dimensional gathers,
In order to improve both the visibility of the plurality of scale lines and the center line and the absorption performance of the absorbent body,
The average area of each dot of the hot melt ink printed on the top sheet is 1000 μm ² or more and 2000 μm ² or less,
a dot interval between dots of the hot-melt ink printed on the top sheet is 50 μm or more and 300 μm or less;
In the area printed with the hot melt ink on the top sheet, the area ratio occupied by the dots of the hot melt ink is 12% or less,
The hot melt ink is printed by inkjet printing,
Furthermore, the absorbent article is characterized in that the inkjet printing is in-line printing incorporated in a manufacturing line of the absorbent article. An absorbent article comprising a liquid-permeable topsheet, a liquid-impermeable backsheet, and an absorbent body disposed between the topsheet and the backsheet,
The absorbent article has three-dimensional gathers along the longitudinal direction,
The absorbent article further has a liquid-diffusing sheet disposed between the top sheet and the absorbent body,
The liquid-diffusing sheet has a plurality of red scale lines printed with dot-like hot-melt ink at predetermined intervals along the longitudinal direction on the body-side surface or the clothing-side surface, and corresponding to each of the scale lines. has a numerical value that
The liquid-diffusing sheet further has a blue center line printed with dot-like hot-melt ink along the longitudinal direction on the body-side surface or the clothing-side surface, at approximately the center position in the width direction,
wherein the plurality of graduation lines and the centerline are visible through the topsheet;
Additional information on any of the scale lines, absorption amount, front-back direction, and decoration is printed on the three-dimensional gathers,
In order to improve both the visibility of the plurality of scale lines and the center line and the absorption performance of the absorbent body,
The average area of each dot of the hot melt ink printed on the liquid diffusing sheet is 1000 μm ² or more and 2000 μm ² or less,
a dot interval between dots of the hot melt ink printed on the liquid diffusing sheet is 50 μm or more and 300 μm or less;
In the area printed with the hot melt ink on the liquid diffusive sheet, the area ratio occupied by the hot melt ink is 12% or less,
The hot melt ink is printed by inkjet printing,
Furthermore, the absorbent article is characterized in that the inkjet printing is in-line printing incorporated in a manufacturing line of the absorbent article. Absorbent article according to claim 1, characterized in that the graduation lines are printed on an embossed topsheet. The liquid-diffusing sheet is a nonwoven fabric,
The absorbent article according to claim 2, wherein the basis weight of the liquid-diffusing sheet is 15 g/ ^m2 or more and 40 g/ ^m2 or less. 5. The scale line according to any one of claims 1 to 4 , characterized in that the scale line is arranged at a substantially central position in the width direction and is formed to have a dimension of 40% or more of the longitudinal dimension of the absorbent article. The absorbent article according to claim 1. 6. The absorbent article according to any one of claims 1 to 5 , wherein the printing line speed in the inkjet printing is 100 m/min or more. The hot-melt ink has a viscosity of 0.1 Pa.s at 120°C. 7. An absorbent article according to any one of the preceding claims, characterized in that it has a melt viscosity of less than or equal to .s. The top sheet is a nonwoven fabric,
The absorbent article according to any one of claims 1 to 7 , wherein the top sheet has a basis weight of 15 g/ ^m2 or more and 40 g/ ^m2 or less.

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