JP5463391B2 - Absorbent articles - Google Patents

Description

  The present invention relates to an absorbent article that has been printed.

Conventionally, absorbent articles such as sanitary napkins, panty liners, incontinence pads, disposable paper diapers are generally made of a liquid-impermeable back sheet made of a polyethylene sheet or a polyethylene sheet laminated nonwoven fabric, and a liquid-permeable surface sheet made of a nonwoven fabric. It has a structure in which an absorbent body made of cotton-like pulp or the like is interposed.
In this type of absorbent article, for various purposes such as obtaining an aesthetic appearance, concealing absorbed excrement, or making it inconspicuous due to camouflage effect, the surface sheet or a sheet between the surface sheet and the absorber It has been proposed to print a pattern on (see, for example, Patent Documents 1 to 3).

JP 2006-181294 A JP 2005-502509 A JP 2002-360620 A

However, the conventional printing object is a nonwoven fabric, and there are problems that precise printing is impossible and printing costs increase due to the reason that the surface fibers are sparse and the surface smoothness is poor.
Further, the conventional pattern printing does not change the appearance before and after absorption, and the degree of use (necessity of replacement) is not known.
Therefore, the main problem of the present invention is that precise printing is possible at low cost, and it has a more aesthetic appearance, can conceal absorbed excrement, or can be made inconspicuous by the camouflage effect, and before and after absorption The object is to provide an absorbent article that can change its appearance and determine the degree of use (necessity of replacement).

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
In an absorbent article having an absorbent body and a covering portion covering the front surface side and the back surface side of the absorbent body,
Between the absorber and the covering portion, a printing sheet formed by printing on a thin paper with water-based ink is interposed,
The printing of the printing sheet is configured to be visible from the outer surface of the absorbent article,
The printing sheet has both a portion printed with the water-based ink and a portion printed with the oil-based ink,
The color of the water-based ink is colorless and transparent or not the same color as the thin paper,
The color of the oil-based ink after drying is colorless and transparent or the same color as the thin paper,
Before the excretion is absorbed, the oil-based ink adhering part is not visible or noticeable,
After the excretion is absorbed, the water-containing ink is absorbed by the non-adhered portion of the oil-based ink without remaining in the oil-ink-attached portion, so that the water-based ink is diffused and permeated to form the thin paper. we intend colored, in the oil-based ink printed portion said without aqueous ink repelled by coloring, the oil-based ink adhesion portion is configured to stand out or stand out against the background of colored portion by the water-based ink,
An absorbent article characterized by the above.

(Function and effect)
The present invention is based on the premise that water-based ink is used. However, if printing is performed only with water-based ink, the printing of the liquid-absorbing portion melts and spreads, and the design effect, concealment, or camouflage effect is impaired. Cheap. On the other hand, when printing with oil-based ink is combined, it is possible to produce a change in appearance with the printed portion of water-based ink while maintaining the design effect, concealment or camouflage effect with the printed portion of oil-based ink.
In particular, since the ink adhering portion by the oil-based ink is hydrophobic, water including water-based ink and excrement is absorbed by the non-adhering portion without remaining in the oil-based ink adhering portion. For this reason, if the colored portion due to water-based ink or excrement and the oil-based ink adhering portion are similar in color, the oil-based ink adhering portion becomes inconspicuous after absorption. On the other hand, if the colored portion due to the water-based ink or excrement and the oil-based ink adhering portion are different colors, the ink adhering portion will come out against the colored portion due to the aqueous ink or excrement.
In addition, since the printing object of the present invention is thin paper, both water-based and oil-based inks are compatible with the pulp fiber, and both inks can be taken into the fiber as well as the surface of the thin paper.
However, since the oil-based ink is hydrophobic, if the area ratio of the adhered portion is too large, the liquid permeability of the printing sheet is impaired. On the other hand, if there are too few oil-based ink adhering parts, there is no point in providing a printing sheet, such as a limited design or a lack of concealment or camouflage effects. Therefore, the total area of the oil-based ink adhering portion is preferably within the above range.

In addition , if the color of the oil-based ink after drying is colorless and transparent or the same color as the thin paper, the ink adhering part is not visible or noticeable before the excrement is absorbed, but the excrement is absorbed after the excrement is absorbed. When water-based ink diffuses and penetrates and the thin paper is colored, the printed portion with oil-based ink is not colored due to the water-based ink being repelled. Appear or stand out. Therefore, the invention described in this section is particularly suitable for concealing absorbed excrement or making it inconspicuous due to the camouflage effect.

  As described above, according to the present invention, it is possible to perform precise printing at a low cost, and the aesthetic appearance is improved, and the absorbed excrement can be concealed or made inconspicuous by the camouflage effect, and before and after absorption. The appearance changes, and advantages such as being able to determine the degree of use (necessity of replacement) are brought about.

It is a perspective view of a pad. It is a top view in the unfolded state of a pad. It is BB sectional drawing of FIG. It is a top view in the development state of the pad which exposed the printing sheet. It is sectional drawing of another example. It is sectional drawing of another example. It is a top view in the unfolded state of a pad. It is BB sectional drawing of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
1 to 3 show a pad 1 according to the present invention, and the pad 1 is provided between a liquid-impermeable back sheet 2 and a liquid-permeable surface sheet 3 (hereinafter simply referred to as a surface sheet). The structure in which the absorber 4 is interposed is provided.
The liquid-impervious back sheet 2 is made of a sheet material having at least water shielding properties such as polyethylene, polypropylene, etc. In addition to this, a non-woven fabric sheet ( In this case, a water-impermeable back sheet is comprised with a waterproof film and a nonwoven fabric.) Etc. can be used. In recent years, those having moisture permeability tend to be suitably used from the viewpoint of preventing stuffiness. The water- and moisture-permeable sheet material is a microporous material obtained by melting and kneading an inorganic filler in an olefin-based resin such as polyethylene or polypropylene to form a sheet, and then stretching in a uniaxial or biaxial direction. A sheet is preferably used.
As the surface sheet 3, a perforated or non-porous nonwoven fabric or a porous plastic film sheet is preferably used. Examples of the material fibers constituting the nonwoven fabric include synthetic fibers such as polyethylene or polypropylene, synthetic fibers such as polyester and polyamide, recycled fibers such as rayon and cupra, and natural fibers such as cotton. A nonwoven fabric obtained by an appropriate processing method such as a lace method, a spun bond method, a thermal bond method, a melt blown method, or a needle punch method can be used. As the plastic film sheet, for example, olefin resins such as polyethylene and polypropylene, polyamide resins such as polyester and nylon, ethylene-vinyl acetate copolymer (EVA), and the like can be preferably used. The nonwoven fabric preferably has a fiber basis weight of about 8 to 50 g / m ² and a thickness of about 0.2 to ² mm.

On the other hand, the absorber 4 interposed between the back sheet 2 and the top sheet 3 is, for example, a mixture of a superabsorbent resin in pulp or a mixture of chemical fibers in a pulp and a superabsorbent resin. Mixed materials are used. A filament aggregate such as cellulose acetate or a non-woven fabric mixed with a superabsorbent resin is also suitable. Superabsorbent resin and pulp can be omitted. Examples of pulp include cellulose fibers such as chemical pulp and molten pulp obtained from wood, and artificial cellulose fibers such as rayon and acetate. Softwood pulp with a longer fiber length is more functional and more expensive than hardwood pulp. It is preferably used in terms of
The absorbent body 4 is wrapped and surrounded by a liquid-permeable packaging sheet 5 in order to quickly retain the shape, diffuse menstrual blood, and the like and prevent reversal of once absorbed menstrual blood and the like. Can do.
Examples of the highly water-absorbing resin include polyacrylate cross-linked products, self-crosslinked polyacrylates, saponified acrylate-vinyl acetate copolymer cross-linked products, cross-linked isobutylene / maleic anhydride copolymer, polysulfone Examples include cross-linked acid salts, and partially cross-linked water-swellable polymers such as polyethylene oxide and polyacrylamide. Among these, those based on acrylic acid or acrylate that are excellent in water absorption and water absorption speed are preferred. A highly water-absorbing resin having water absorption performance can adjust the water absorption force and the water absorption speed by adjusting the crosslinking density and the crosslinking density gradient in the production process. The content of the superabsorbent resin is desirably 10 to 60%. When the content of the superabsorbent resin is less than 10%, sufficient absorbability cannot be provided, and when it exceeds 60%, the entanglement between the pulp fibers disappears, the sheet strength decreases, and tears, cracks, etc. Is likely to occur.

Both side portions of the back sheet 2 protrude from both side edges of the top sheet 3, and the elastic band 8 is stretched in the front-rear direction from the protruding portion to the side portion of the top sheet 3, and is pasted with an adhesive HM or the like. Yes. The elastic band 8 is formed by fixing an elongated elastic member such as a rubber thread 9 between the folded sheets in the front-rear direction, and the pad is shown in FIG. As shown, it is transformed into a hull shape. On both the front and rear sides of the absorbent body 4, a sheet (a printing sheet or intermediate sheet 7 described later) in which the top sheet 3 is interposed directly with respect to the liquid-impermeable back sheet 2 or between the absorbent body 4 and the top sheet 3. It is joined indirectly by an adhesive means such as a hot melt adhesive.
Characteristically, between the surface sheet 3 and the absorber 4, the printing sheet 6 formed by printing on thin paper with water-based ink is arrange | positioned. FIG. 4 shows a state in which the top sheet 3 and the elastic band 8 are removed and the print sheet 6 is exposed. The thin paper used for the printing sheet 6 has a basis weight of 8 to 80 g / m ² , particularly 10 to 30 g / m ² and a crepe rate of 1 to 35%, particularly 10 from the viewpoint of liquid permeability and printability. What is -25% is suitable.
Thin paper reduces the volume when absorbing liquid, improves transparency, and improves adhesion with adjacent members, so the appearance of printing changes before and after absorbing liquid, and the design effect and concealment before and after absorbing liquid Alternatively, the camouflage effect can be changed. When utilizing such an effect, the thin paper used for the printing sheet 6 preferably has a opacity change of 50% or more before and after water absorption.

The printing sheet 6 can be arranged on either one side or both sides of the absorber 4 depending on the purpose of printing. For example, in order to exhibit the excrement concealment or the camouflage effect, the printing sheet 6 is provided between the top sheet 3 and the absorber 4 as illustrated. On the other hand, when printing is made visible as a part of the outer surface design of the product with the front sheet 3 being folded in two or three so that the front sheet 3 is inside, the printed sheet 6 is the absorber 4 and the back sheet. 2 is provided. Of course, it can also be provided in both of them. Although not shown, the printing sheet 6 can be arranged so as to enclose the absorber 4. At that time, the seam of the wrapped printing sheet 6 may be arranged on either the top sheet 3 side or the back sheet 2 side.
The printing of the printing sheet 6 may be provided on at least one of the front and back sides of the printing sheet 6, but if the printing is to be conspicuous before the excretion is absorbed, the printing sheet 6 is made up of the top sheet 3 and the absorber 4. When it is provided in the middle, printing may be performed on the surface on the surface sheet 3 side, and when it is provided between the absorber 4 and the back surface sheet 2, the surface on the back sheet 2 side may be printed. In addition, if it is not desired to make the printing stand out before the excretion absorption, it is preferable to perform the printing on the contrary.
Since the printing sheet 6 is covered, it is necessary to see the printing through the covering portion. Specifically, when printing is performed on the side surface of the cover portion of the print sheet 6, the opacity of the cover portion of the print sheet 6 is preferably 90% or less, particularly preferably 75% or less. When the printing sheet 6 is provided on the front surface side of the absorber 4, the covering portion is a portion on the front surface side of the printing sheet 6 (in the illustrated embodiment, only the front sheet 3), and on the back surface side of the absorber 4. When the print sheet 6 is provided, it is a portion on the back side of the print sheet. The opacity can be adjusted by the color of the fiber and the fiber density when the material of the covering portion is a nonwoven fabric, and can be adjusted by the color and thickness in the case of a water shielding sheet such as polyethylene.

The dimensions and arrangement of the print sheet 6 can be appropriately determined according to the printing purpose. For example, in order to display the excrement concealment or the camouflage effect, it is desirable that the print sheet 6 covers at least the center in the front-rear direction of the article. For this reason, the printing sheet 6 extends from the front end to the rear end of the absorbent body 4 in the front-rear direction or from the front end to the rear end of the article, and from one side of the absorbent body 5 or the vicinity thereof in the width direction. It can extend to the other side or its vicinity. In order to exhibit the design effect, it is desirable that the printing sheet 6 covers many parts of the article. For this reason, the print sheet 6 extends from the front end to the rear end of the article in the front-rear direction, and extends from one side portion or the vicinity thereof to the other side portion or the vicinity thereof in the width direction. Can do. Further, when the front and rear display of the article is performed by printing, the print sheet 6 can be disposed only at the front and rear ends of the article.
The printed content is not particularly limited, but in addition to a pattern such as a floral pattern, a symbol (including characters) that represents a specific meaning such as a front-rear display or a used display, or a symbol (including characters) that does not represent a specific meaning ), Or a combination of a plurality of these. In particular, it is preferable that unit patterns such as floral patterns are scattered at a predetermined interval because the degree of freedom in design is high and the camouflage effect is high.

The printing ink is not particularly limited as long as a water-based ink is used, but it is colorless and transparent or the same color as crepe paper is avoided. In order to enhance the concealment or camouflage effect of the excrement, the color of the water-based ink is preferably similar to the color of the excrement, but in order to enhance the design effect, it is preferably a different color.
As one preferred form, it is proposed to use a water-based ink with a plurality of color components having different solubility and color in water. When such a water-based ink is used, even if it is single color printing before dissolution, after the ink is dissolved, the color components are separated due to the difference in solubility and become striped. Therefore, what was initially a single color can be changed into a plurality of colors after water absorption, thereby bringing about a change in appearance before and after use.
In addition, a form having a plurality of water-based ink printing portions having different colors is also proposed. This form includes so-called color printing. As an example, a form in which a background color is solidly applied and a design or the like is printed on the background with a different color, or each part of the design is printed in a different color. Can be mentioned. In such a form, when the excrement is absorbed, a plurality of water-based inks having different colors are melted and color mixing occurs, whereby a change in appearance before and after use can be brought about. In this embodiment, it is desirable to arrange the printed portions of each color as close to ten as the mixing of the colors occurs.

  As a reference form, a form is proposed in which an embossed recess extending from the covering portion to the absorber 4 via the printing sheet 6 is formed. Such an embossed recess includes, for example, a fit emboss 10 that is often used to improve fit to the body (particularly in sanitary napkins) as shown in FIGS. 7 and 8, but is not limited thereto. However, it includes a form in which a pattern similar to the printed content (for example, a floral pattern as shown in FIG. 2) or the like is formed by the embossed recesses. The portion where the embossed recess is formed has a high density. The liquid moves from the low density side to the high side. Therefore, in this embodiment, when the excrement is absorbed, the ink dissolved by moisture gathers in the embossed concave portion having a high density, and the embossed concave portion becomes colored and stands out, so that the appearance before and after use can be changed. For example, when a single-color solid printing was applied to a printing sheet with water-based ink and a pattern or the like was given by an embossed recess, the embossed recess that was not conspicuous at the beginning was colored in the excrement absorbing part, as if it was initially absent The effect is as if a design has appeared. Also, for example, when printing a pattern or the like on a printing sheet with water-based ink and adding a pattern or the like with an embossed recess, only the pattern of the water-based ink printed portion is initially conspicuous and the embossed recess is not conspicuous. However, after absorption of excrement, the design of the water-based ink printed portion is blurred or disappeared, and the design of the embossed recess is colored, so that the effect is as if the design has changed.

And in this invention, combining water-based ink printing part and oil-based ink printing part is proposed. The oil-based ink is suitable for applying a design that does not change before and after absorption because the ink does not bleed due to liquid absorption. If only water-based printing is used, the printing of the liquid absorption part will melt and bleed, and the design effect, concealment or camouflage effect will tend to be impaired. While maintaining the effect and the concealment or camouflage effect, it is possible to produce a change in appearance by the printed portion with water-based ink.
In particular, as in the present invention, if the oil-based ink is colorless and transparent or the same color as the thin paper, the oil-based ink adhering portion is not visible or noticeable before absorption of the water-based ink or excrement, but the excrement After absorption of water, when excrement and water-based ink diffuse and permeate and the crepe paper of the printing sheet 6 is colored, the printing portion with oil-based ink is repelled and the water-based ink is not repelled. Since the portion appears to stand out or becomes conspicuous with a colored portion due to water-based ink or the like as a background, it is particularly suitable for concealing the absorbed excrement or making it inconspicuous due to the camouflage effect. From this viewpoint, oil-based inks having high water repellency are suitable.

In addition, a deodorizer, an antibacterial agent, a pH adjuster, a fragrance | flavor, surfactant, and various indicator agents can also be mix | blended with printing ink irrespective of water nature and oiliness.
Although the total area of the oil-based ink print portion can be determined as appropriate, the proportion of the print sheet 6 is preferably 1 to 90%, particularly preferably 5 to 75%. If the area ratio of the oil-based ink adhering portion is too large, the liquid permeability of the printing sheet 6 is impaired. On the other hand, if there are too few oil-based ink adhering parts, the meaning of providing the printing sheet 6 will be lost, for example, the design is limited, and the concealment or camouflage effect becomes poor.
The printing method of the printing sheet 6 is not particularly limited in both cases of water-based ink and oil-based ink, and letterpress printing, planographic printing, intaglio printing, stencil printing, and inkjet printing can also be applied.

<Other embodiments>
(A) When the packaging sheet 5 of the absorbent body 4 is a thin paper, the packaging sheet 5 can be printed to obtain the printed sheet of the present invention. Thereby, the effect similar to having arrange | positioned the printing sheet 6 to the front and back both sides of the absorber 4 is exhibited. Also, without changing the assembly line only by changing the material
Articles can be manufactured.

(B) As shown in FIG. 5, a hydrophilic intermediate sheet 7 can be disposed between the printing sheet 6 and the surface sheet 3. The intermediate sheet 7 should just be hydrophilic with respect to a bodily fluid. Specifically, by using recycled fibers such as rayon and cupra, natural fibers such as cotton, the material itself has hydrophilicity, or synthesis of olefins such as polyethylene or polypropylene, polyesters, polyamides, etc. The fiber which surface-treated with the hydrophilizing agent and provided the hydrophilic property can be used. By disposing such an intermediate sheet 7, it is possible to prevent body fluid once absorbed by the absorbent body 4 from returning to the topsheet 3 side. In this case, the covering portion is the portion of the top sheet 3 and the intermediate sheet 7, and it is preferable to determine the type and density of the fibers so that the opacity when they are superposed is 90% or less. As shown in FIG. 6, the intermediate sheet 7 can be disposed between the printing sheet 6 and the absorber 4. In this case, since the covering portion of the printing sheet 6 is only the surface sheet 3, the opacity of the surface sheet 3 is preferably 90% or less.

(C) When the pad 1 is used while being interposed between the diaper and the crotch, a liquid-permeable back sheet 2 can be used.

(D) A pad-type absorbent article such as a sanitary napkin is generally coated with an adhesive for preventing slippage on the back surface, and a release sheet is attached to cover the adhesive layer. It is sold in the form of individual packaging. Since these portions constitute the coating portion of the present invention, the opacity including these portions is preferably 90% or less, particularly 70% or less.

(E) In the case where the printing sheet 6 is positioned between the absorbent body 4 and the covering portion that covers the surface side of the absorbent body 4, in order to prevent the dissolved water-based ink from passing through the covering portion and adhering to the skin. Moreover, it is preferable that the hydrophilicity of the covering portion covering the surface side of the absorbent body 4 is lower than that of the crepe paper of the printing sheet 6. Specifically, in the above-described embodiment, when the intermediate sheet 7 is included, it is sufficient that the hydrophilicity of at least one of the top sheet 3 and the intermediate sheet 7 is lower than that of the crepe paper of the printing sheet 6. The degree is preferably increased in the order of the top sheet 3, the intermediate sheet 7, and the crepe paper of the printing sheet 6. Such a magnitude relationship of the hydrophilicity can be generated by selecting a material for each part, using a known hydrophilic agent, or the like.
In addition, when the covering portion covering the surface side of the absorbent body 4 is formed of a fiber assembly such as a nonwoven fabric, the fiber density of the covering portion is printed together with or instead of the above-described hydrophilicity relationship. It is also preferable to make it lower than the crepe paper of the sheet 6. Specifically, in the above-described embodiment, when the intermediate sheet 7 is included, it is sufficient that the fiber density of at least one of the top sheet 3 and the intermediate sheet 7 is lower than that of the crepe paper of the printing sheet 6. It is preferable that the density increases in the order of the top sheet 3, the intermediate sheet 7, and the crepe paper of the printing sheet 6. Such a magnitude relationship of the fiber density can be generated by selecting a material of each part or performing compression processing by a nip roll or the like at the time of manufacture.

  The present invention can be applied to a wide range of uses such as sanitary napkins, panty liners, cage sheets, and incontinence pads.

DESCRIPTION OF SYMBOLS 1 ... Pad, 2 ... Back surface sheet, 3 ... Front surface sheet, 4 ... Absorber, 5 ... Wrapping paper, 6 ... Printing sheet, 7 ... Intermediate sheet, 8 ... Elastic band, 9 ... Rubber thread, 10 ... Embossing recessed part.

Claims (1)

In an absorbent article having an absorbent body and a covering portion covering the front surface side and the back surface side of the absorbent body,
Between the absorber and the covering portion, a printing sheet formed by printing on a thin paper with water-based ink is interposed,
The printing of the printing sheet is configured to be visible from the outer surface of the absorbent article,
The printing sheet has both a portion printed with the water-based ink and a portion printed with the oil-based ink,
The color of the water-based ink is colorless and transparent or not the same color as the thin paper,
The color of the oil-based ink after drying is colorless and transparent or the same color as the thin paper,
Before the excretion is absorbed, the oil-based ink adhering part is not visible or noticeable,
After the excretion is absorbed, the water-containing ink is absorbed by the non-adhered portion of the oil-based ink without remaining in the oil-ink-attached portion, so that the water-based ink is diffused and permeated to form the thin paper. we intend colored, in the oil-based ink printed portion said without aqueous ink repelled by coloring, the oil-based ink adhesion portion is configured to stand out or stand out against the background of colored portion by the water-based ink,
An absorbent article characterized by the above.

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