JP2005261453A - Pressure sensitive adhesive sheet for paper diaper inside and paper diaper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure sensitive adhesive sheet for a paper diaper inside and a paper diaper, even if being directly stuck to the skin, preventing the skin surface from getting stuffy and preventing contact dermatitis and flare by infiltrating moisture caused by sweating. <P>SOLUTION: This pressure sensitive adhesive sheet for the paper diaper inside is used, when the paper diaper is worn, by being fixed to the inside of the paper diaper in such a form that the pressure sensitive adhesive layer surface can directly contact with the skin of a wearer, and the water-vapor transmission ratio (under a temperature 40°C, a humidity 30 %RH and the thickness of the pressure sensitive adhesive 100 μm) of the pressure sensitive adhesive is 800 g/m<SP>2</SP>day or more. Alternatively, when the paper diaper is worn, the pressure sensitive adhesive layer surface is fixed to the inside of the paper diaper in such a form as to directly contact with the skin of the wearer and the pressure sensitive adhesive layer comprises pressure sensitive adhesive mainly composed of polyether-based copolymer having at least single alkenyl group in a molecule. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pressure-sensitive adhesive sheet for the inner surface of a paper diaper that is used to increase adhesion to a wearer when wearing a paper diaper, and a paper diaper using the pressure-sensitive adhesive sheet for the inner surface of the paper diaper, and more specifically, pressure-sensitive adhesive for the inner surface of a paper diaper. Used for wearing disposable diapers with the adhesive surface of the sheet in direct contact with the skin of the wearer, and prevents moisture irritation and redness even when applied for a long time due to the moisture permeability of the adhesive composition. The present invention also relates to a pressure-sensitive adhesive sheet for inner surfaces of paper diapers that can be prevented and a paper diaper using the pressure-sensitive adhesive sheet for inner surfaces of a paper diaper.

  Conventionally, as a means for fixing a paper diaper to a wearer, a means for fixing using a fixing member such as an adhesive sheet is widely used on the outer surface of the paper diaper (that is, in a form that does not directly contact the wearer's skin). (See Patent Document 1). However, when fixing on the outer surface of the paper diaper using a fixing member such as an adhesive sheet, it is difficult for the wearer to wear the paper diaper with excellent adhesion (fitness) and excellent leakage prevention. . If the adhesiveness to the wearer of a paper diaper is not enough, a wearer's usability will worsen. Moreover, if it is not worn with sufficient leakage prevention properties, leakage of excrement, diffusion of excrement odor, and the like may occur. In addition, for example, when a baby diaper is worn by an infant, even if the paper diaper can be worn with sufficient adhesion and leakage prevention properties when worn, if the diaper becomes large after eating after wearing the paper diaper, The adhesiveness and the leakage prevention property are lowered to cause problems such as a decrease in the feeling of use of the disposable diaper as described above, leakage of excrement, and diffusion of excrement odor.

  Therefore, in order to increase the adhesion to the wearer of the paper diaper and the prevention of leakage, there is a method in which the paper diaper is directly attached to the skin to the wearer via an adhesive sheet at the waist opening of the paper diaper or the leg opening. May be valid. However, when a conventional pressure-sensitive adhesive is used for such a purpose, there is a possibility that it may have an adverse effect on skin such as stuffiness, redness, and rash.

Japanese Patent Laid-Open No. 5-17728

Therefore, even if the object of the present invention is directly attached to the skin, a paper diaper that can permeate moisture caused by perspiration to suppress or prevent the skin surface from becoming stuffy and to suppress or prevent skin irritation and redness. It is an object of the present invention to provide an inner surface pressure-sensitive adhesive sheet and a paper diaper using the inner surface pressure-sensitive adhesive sheet.
Another object of the present invention is to provide excellent adhesive performance even when no tackifying resin is used in the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer or even when the amount used is reduced. An object is to provide a pressure-sensitive adhesive sheet for the inner surface of a paper diaper and a paper diaper using the pressure-sensitive adhesive sheet for the inner surface of a paper diaper.
Still another object of the present invention is to provide a paper diaper inner surface pressure-sensitive adhesive sheet that can improve adhesion to a wearer of a paper diaper and leakage prevention, and a paper diaper using the paper diaper inner surface pressure-sensitive adhesive sheet.

  As a result of intensive studies to achieve the above object, the inventors of the present invention have adopted an adhesive having moisture permeability as the adhesive constituting the adhesive layer, and for the inner surface of the paper diaper fixed to the inner surface of the paper diaper. It has been found that even if the adhesive sheet is directly pasted, moisture due to sweating when wearing a paper diaper can escape through the adhesive layer to suppress or prevent stuffiness. Further, when the pressure-sensitive adhesive layer is composed of a pressure-sensitive adhesive mainly composed of a specific polymer, it is possible to use an additional component such as a tackifying resin or a softener other than the main polymer as the pressure-sensitive adhesive component, or those It has been found that even if the amount of use is reduced, excellent adhesion performance can be exhibited. The present invention has been completed based on these findings.

That is, the present invention is an adhesive sheet that is used by being fixed to the inner surface of a paper diaper in a form that allows the surface of the adhesive layer to directly contact the wearer's skin when the paper diaper is worn, Provided is a pressure-sensitive adhesive sheet for the inner surface of a disposable diaper, wherein the moisture permeability of the layer (temperature: 40 ° C., humidity: 30% RH, pressure-sensitive adhesive layer thickness: 100 μm) is 800 g / m ² · day or more.

  Further, the present invention is an adhesive sheet that is used by being fixed to the inner surface of a paper diaper in a form that allows the surface of the adhesive layer to be in direct contact with the wearer's skin when the paper diaper is worn. Provided is a pressure-sensitive adhesive sheet for the inner surface of a disposable diaper, characterized in that the layer is composed of a pressure-sensitive adhesive mainly composed of a polyether polymer having at least one alkenyl group in the molecule. The number average molecular weight of the polyether polymer is preferably 5,000 to 50,000.

  In the present invention, the pressure-sensitive adhesive layer is preferably a porous pressure-sensitive adhesive layer, and the porous pressure-sensitive adhesive layer can be formed by applying a pressure-sensitive adhesive in a fibrous form. Furthermore, the pressure-sensitive adhesive layer may be formed by applying a solventless pressure-sensitive adhesive.

  In the present invention, the pressure-sensitive adhesive sheet is a paper diaper that is fixed to the inner surface in such a form that the surface of the pressure-sensitive adhesive layer can be in direct contact with the wearer's skin when the paper diaper is worn. Also included is a paper diaper characterized by being an adhesive sheet for the inner surface of the paper diaper. As such a pressure-sensitive adhesive sheet for the inner surface of a paper diaper, when the paper diaper is worn, the surface of the pressure-sensitive adhesive layer is directly on the skin in at least one site selected from the back, waist, legs, abdomen and buttocks of the wearer. It may be fixed to the inner surface in a form that allows contact.

  According to the pressure-sensitive adhesive sheet for the inner surface of the paper diaper of the present invention, even when directly applied to the skin, moisture caused by sweating is permeated to suppress or prevent stuffiness on the skin surface and to suppress or prevent skin irritation and redness. be able to. Moreover, the pressure-sensitive adhesive sheet for the inner surface of the paper diaper according to the present invention exhibits excellent adhesive performance even if no tackifier resin is used in the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer or the amount of the pressure-sensitive adhesive is reduced. can do. Therefore, according to the paper diaper in which the pressure-sensitive adhesive sheet for the inner surface of the paper diaper is used, the adhesion to the wearer of the paper diaper and the leakage preventing property can be enhanced.

[Adhesive sheet for paper diaper inner surface]
The pressure-sensitive adhesive sheet for the inner surface of the paper diaper of the present invention has a moisture permeability of 800 g / m ² · day or more (temperature (temperature of outside air) 40 ° C., humidity (humidity of outside air) 30% RH, pressure-sensitive adhesive layer thickness 100 μm). One of the characteristics is that it has an agent layer. Thus, when the moisture permeability of the pressure-sensitive adhesive layer (temperature 40 ° C., humidity 30% RH, pressure-sensitive adhesive layer thickness 100 μm) is 800 g / m ² · day or more, the pressure-sensitive adhesive layer is used to make a disposable diaper. Even if the adhesive sheet for the inner surface is applied directly to the skin (directly applied), the adhesive layer allows moisture from perspiration to permeate and suppress or prevent stuffiness on the skin surface, causing skin irritation and redness Can be effectively suppressed or prevented.

The moisture permeability of the pressure-sensitive adhesive layer (temperature 40 ° C., humidity 30% RH, pressure-sensitive adhesive layer thickness 100 μm) is preferably 1200 g / m ² · day or more, and more preferably 2000 g / m ² · day or more. Is preferred. The upper limit of moisture permeability is not particularly limited, but may be, for example, about 4000 g / m ² · day (temperature 40 ° C., humidity 30% RH, pressure-sensitive adhesive layer thickness 100 μm). When the moisture permeability of the pressure-sensitive adhesive layer (temperature: 40 ° C., humidity: 30% RH, pressure-sensitive adhesive layer thickness: 100 μm) is less than 800 g / m ² · day, The problem of redness is likely to occur.

In the present invention, the moisture permeability of the pressure-sensitive adhesive layer (or pressure-sensitive adhesive) can be measured as follows.
(Measurement method of moisture permeability of pressure-sensitive adhesive layer)
(1) Apply an adhesive to the entire surface of the application area on the separator using an applicator, and dry / crosslink as necessary to form an adhesive layer having a thickness of 100 μm (thickness after drying). .
(2) The pressure-sensitive adhesive layer formed on the separator is transferred to one side of a nylon nonwoven fabric (polyamide nonwoven fabric) to produce a pressure-sensitive adhesive sheet. In addition, as said nylon nonwoven fabric, a basic weight uses 40 g / m < ² >. Specifically, as the nylon nonwoven fabric, for example, a trade name “ELTAS” (manufactured by Asahi Kasei Co., Ltd.) can be used.
(3) After putting 20 g of water into a glass cup having a height of 40 mm and an inner diameter of 40 mmφ, as shown in FIG. 1, the adhesive sheet is placed so that the adhesive layer is on the lower side and the opening of the glass cup is covered. The adhesive sheet is fixed to the glass cup by placing it on the upper surface of the glass cup and pasting the periphery of the glass cup using a vinyl tape having a trade name “No. 51” (manufactured by Nitto Denko Corporation).
(4) The glass cup covered with this pressure-sensitive adhesive sheet is placed in a constant temperature and humidity chamber at 40 ° C. and 30% RH for 20 minutes, taken out, weighed, and this weight is taken as the initial weight (W _O ).
(5) Next, it is again put in a constant temperature and humidity chamber of 40 ° C. and 30% RH, taken out after 4 hours, measured for weight (W _H ), and based on the following formula (a): The moisture permeability (g / m ² · day) is calculated.
Moisture permeability = [(W _O −W _H ) × 24] / [(0.02) ² × π × 4] Formula (a)
[In the formula (a), the unit of moisture permeability is g / m ² · day. W _O : initial weight, W _H : weight after 4 hours. π is the circumference and can be 3.14]

  FIG. 1 is a schematic view showing a method for measuring moisture permeability of an adhesive layer. In FIG. 1, 4 is an adhesive sheet, 4a is an adhesive layer, 4b is a nylon nonwoven fabric, 5 is a glass cup (height 40 mm, inner diameter 40 mmφ), 5a is an opening (upper surface) of the glass cup 5, and 6 is water. is there.

  The pressure-sensitive adhesive sheet for the inner surface of the paper diaper of the present invention is mainly composed of a polyether polymer having at least one alkenyl group in the molecule (sometimes referred to as “alkenyl group-containing polyether polymer”). One of the characteristics is that it has an adhesive layer composed of an adhesive. As described above, when a pressure-sensitive adhesive mainly composed of an alkenyl group-containing polyether polymer is used, even if a tackifying resin is not used or the amount used is reduced, sufficient adhesive performance is obtained. Can be demonstrated.

  In addition, although the adhesive sheet for paper diaper inner surfaces of this invention should just satisfy either one of the said 2 characteristics, it is preferable that both of 2 characteristics are satisfied.

  The adhesive sheet for the inner surface of the paper diaper of the present invention has a base material as long as it has an adhesive layer that satisfies one of the two characteristics (particularly, both of the two characteristics are satisfied). It does not need to have a base material. Accordingly, as the pressure-sensitive adhesive sheet for the inner surface of the paper diaper, (1) a pressure-sensitive adhesive sheet for the inner surface of the paper diaper having a configuration formed only from the pressure-sensitive adhesive layer (a pressure-sensitive adhesive sheet for the inner surface of the paper diaper), (2) at least one of the base materials An adhesive sheet for the inner surface of a paper diaper having a configuration in which an adhesive layer is formed on the surface (both sides or one side) (adhesive sheet for the inner surface of a paper diaper with a base material) and the like. In the present invention, as the pressure-sensitive adhesive sheet for the inner surface of the paper diaper, the pressure-sensitive adhesive sheet for the inner surface of the paper diaper having the configuration (1) (that is, the pressure-sensitive adhesive sheet for the inner surface of the paper diaper having a configuration formed only from the pressure-sensitive adhesive layer) is suitable. It is.

  In the pressure-sensitive adhesive sheet for paper diaper inner surface of the present invention, the pressure-sensitive adhesive surface may be protected by a known release liner (separator).

  In addition, when the pressure-sensitive adhesive sheet for the inner surface of the paper diaper is a pressure-sensitive adhesive sheet for the inner surface of the paper diaper, it is sufficient that the pressure-sensitive adhesive layer is formed on at least one surface of the base material, and the other surface of the base material A known pressure-sensitive adhesive layer or adhesive layer may be formed.

  Furthermore, the adhesive sheet for the inner surface of the paper diaper may be formed in a form wound in a roll shape, or may be formed in a form in which the sheets are laminated. That is, the pressure-sensitive adhesive sheet for the inner surface of the paper diaper of the present invention can have a form such as a sheet form or a tape form.

(Adhesive layer)
In this invention, as an adhesive which comprises the adhesive layer of the adhesive sheet for paper diaper inner surfaces, the moisture permeability at the time of forming an adhesive layer (temperature 40 degreeC, humidity 30% RH, the thickness of an adhesive layer 100 micrometers) is 800g. The composition is not particularly limited as long as it is at least / m ² · day. Therefore, from this viewpoint, as the pressure-sensitive adhesive, a known or common pressure-sensitive adhesive (for example, an acrylic pressure-sensitive adhesive, a rubber pressure-sensitive adhesive, a silicone pressure-sensitive adhesive, a urethane pressure-sensitive adhesive, etc.) can be used. However, as described above, from the viewpoint of achieving both moisture permeability and the adhesive properties of the pressure-sensitive adhesive sheet for the inner surface of a paper diaper, the pressure-sensitive adhesive includes a polyether polymer (alkenyl group having at least one alkenyl group in the molecule). A pressure-sensitive adhesive mainly comprising (containing polyether polymer) is preferred.

  In the alkenyl group-containing polyether polymer, the alkenyl group is preferably an alkenyl group having a double bond at the terminal (such as a vinyl group or a vinylalkyl group). Specifically, the alkenyl group is preferably a vinyl group; a 1-alkylvinyl group such as 1-methylvinyl group (isopropenyl group), 1-ethylvinyl group, 1-propylvinyl group, 1-isopropylvinyl group, etc. In particular, a vinyl group and a 1-methylvinyl group are preferable. The alkenyl groups may be used alone or in combination of two or more.

The alkenyl group may be directly bonded to the polyether polymer, or may be bonded via another group (such as a divalent organic group). Other groups through which the alkenyl group is bonded to the polyether polymer include, for example, “—O—”, “—OC (═O) —”, “—C (═O) O—”, “ -R ^a O - "," ^{- R a OC (= O)} - "," ^{- R a OC (= O)} O - , "" ^{- R a OC (= O)} NH - , "" - R ^{In addition to “a} C (═O) O—” (R ^a is a divalent organic group), the group “—O—” in these groups is “—S—” or “—NH—”. Can be mentioned. In these exemplified groups, the left side is bonded to the alkenyl group, and the right side is bonded to the polyether polymer.

（式（１）において、Ｒ¹はポリエーテル系重合体を示し、Ｒ²は水素原子又はメチル基を示す。Ｒ³は「−Ｏ−」、「−ＯＣ（＝Ｏ）−」、「−Ｃ（＝Ｏ）Ｏ−」、「−Ｒ⁴Ｏ−」、「−Ｒ⁴ＯＣ（＝Ｏ）−」、「−Ｒ⁴ＯＣ（＝Ｏ）Ｏ−」（なお、これらのＲ³の基は、左側が「ＣＨ₂＝Ｃ（Ｒ²）−」と結合し、右側が「Ｒ¹」と結合する）であり、Ｒ⁴は２価の有機基である。ｍは０又は１であり、ｎは正の整数である） Specifically, preferred alkenyl group-containing polyether polymers include alkenyl group-containing polyether polymers represented by the following formula (1).

(In the formula (1), R ¹ represents a polyether polymer, R ² represents a hydrogen atom or a methyl group. R ³ represents “—O—”, “—OC (═O) —”, “— C (═O) O— ”,“ —R ⁴ O— ”,“ —R ⁴ OC (═O) — ”,“ —R ⁴ OC (═O) O— ”(in these R ³ groups Is bonded to “CH ₂ ═C (R ² ) —” on the left side and bonded to “R ¹ ” on the right side, and R ⁴ is a divalent organic group, m is 0 or 1 , N is a positive integer)

In the formula (1), the R ¹ polyether polymer is not particularly limited as long as it is a polymer having an ether bond in the molecule. For example, as a repeating unit, oxyethylene, oxypropylene, oxyisopropylene, And polyoxyalkylene polymers having one or more oxyalkylenes such as oxytetramethylene. Specifically, examples of the R ¹ polyether polymer include polyoxyethylene, polyoxypropylene, polyoxytetramethylene, oxyethylene-oxypropylene copolymer (for example, polyoxyethylene-polyoxypropylene block copolymer). And oxyethylene-oxypropylene random copolymer).

R ⁴ in R ³ is a divalent organic group, wherein the divalent organic group is not particularly limited, for example, one or more ether bonds may have a divalent hydrocarbon radical Is preferred. As the divalent hydrocarbon group which may have such an ether bond, a divalent hydrocarbon group having 1 to 20 carbon atoms is preferable. Specifically, the divalent hydrocarbon group which may have an ether bond includes an alkylene group (for example, a methylene group, an ethylene group, a trimethylene group, a propylene group, a tetramethylene group, a 2-methyltrimethylene group). , Pentamethylene group, hexamethylene group, etc.) and alkylene-oxy-alkylene groups (for example, ethylene-oxy-ethylene group, ethylene-oxy-trimethylene group, etc.). As the divalent hydrocarbon group, in addition to the above, an oxyalkylene group, an oxycarbonylalkylene group, an oxycarbonyloxyalkylene group (in which these oxy moieties are bonded to an alkenyl group) can also be used. It is.

As R ³ , “—R ⁴ O—” is preferable, and “—CH ₂ O—” is particularly preferable.

m is 0 or 1, and when m is 0, R ³ is not present and “CH ₂ ═C (R ² ) —” is directly bonded to “R1”.

  n is a positive integer, for example, an integer of 1 to 10 (preferably 1 to 4, more preferably 1 or 2).

In the formula (1), “CH ₂ ═C (R ² ) — (R ³ ) _m —” is any part of the polyether polymer of R ¹ (preferably, the main chain or the side chain) It is only necessary that n bonds are bonded to the terminal ends of the main chain, particularly the terminal of the main chain. Therefore, it can be said in detail that “R ¹ is the main part of the polyether polymer”. When a plurality of “CH ₂ ═C (R ² ) — (R ³ ) _m —” is bonded to the polyether polymer of R ¹ , all or part of “CH ₂ ═C (R ² )-(R ³ ) _m — ”may be bonded to the same site of the polyether polymer, or all may be bonded to different sites.

  As such alkenyl group-containing polyether polymers, for example, known alkenyl group-containing polyether polymers described in JP-A-4-145188, JP-A-5-209164 and the like are used. Can do.

  The alkenyl group-containing polyether polymer has a number average molecular weight of 5,000 to 50,000 (5,000 to 50,000), preferably 10,000 to 30,000 (10,000 to 30,000). 000), more preferably 15,000 or more and 25,000 or less (15,000 to 25,000). When the number average molecular weight of the alkenyl group-containing polyether polymer is less than 5,000, the tackiness of the cured product is lowered, while when it exceeds 50,000, the coating property is lowered.

  In addition, even if the adhesive by an alkenyl-group containing polyether polymer is a solventless type adhesive, it can be applied at room temperature (for example, 23 degreeC). From this point, it can be said that the alkenyl group-containing polyether polymer is excellent as an adhesive component (polymer component or base polymer) of the adhesive constituting the adhesive layer of the adhesive sheet for the inner surface of a disposable diaper.

  A method for producing such an alkenyl group-containing polyether polymer is not particularly limited, and a known or commonly used method can be employed. For example, JP-A-4-145188 and JP-A-5-209164 As described in the publications, a method of introducing an alkenyl group after preparing a polyether polymer, a method of introducing an alkenyl group during preparation of a polyether polymer, and the like can be used.

  As a pressure-sensitive adhesive mainly composed of an alkenyl group-containing polyether polymer (sometimes referred to as “alkenyl group-containing polyether pressure-sensitive adhesive”), a cross-linking agent can be used as long as it mainly comprises a alkenyl group-containing polyether polymer. , Other components such as a catalyst (for example, hydrosilylation catalyst) and a storage stability improver may be contained. The crosslinking agent is not particularly limited as long as it can crosslink an alkenyl group-containing polyether polymer. For example, a compound having at least two hydrosilyl groups in a molecule (“hydrosilyl group-containing compound”). May be suitably used. Examples of the compound containing a plurality of hydrosilyl groups as the crosslinking agent include “compounds having at least two hydrosilyl groups in the molecule” described in JP-A-4-145188 and JP-A-5-209164. (B) component] "etc. are mentioned.

  As the catalyst, when a hydrosilyl group-containing compound is used as a crosslinking agent, a hydrosilylation catalyst can be suitably used. The hydrosilylation catalyst is not particularly limited as long as it is a catalyst that can promote a crosslinking reaction between an alkenyl group-containing polyether polymer and a hydrosilyl group-containing compound. For example, JP-A-4-145188 and Examples thereof include “hydrosilylation catalyst [component (C)]” described in JP-A-5-209164.

  Furthermore, the storage stability improver is not particularly limited as long as it can enhance the storage stability of a composition mainly composed of an alkenyl group-containing polyether polymer. For example, JP-A-4-145188 "Storage stability improver [(E) component in JP-A-5-209164]" described in JP-A-5-209164 and the like.

The pressure-sensitive adhesive (particularly, the alkenyl group-containing polyether-based pressure-sensitive adhesive) is adjusted so that the gel fraction of the pressure-sensitive adhesive composition after crosslinking is 30% by weight or more and 80% by weight or less (30 to 80% by weight). Are preferred. Moreover, what was adjusted so that the storage elastic modulus (G ') of the adhesive composition after bridge | crosslinking might become 1 * 10 < ⁵ > Pa or less at room temperature is preferable. The gel fraction and storage elastic modulus (G ′) of such a crosslinked pressure-sensitive adhesive composition are determined depending on the type and content ratio of the pressure-sensitive adhesive component (particularly, the alkenyl group-containing polyether polymer), the crosslinking agent and the catalyst. It can be controlled by appropriately adjusting the type and the amount of use. When the alkenyl group-containing polyether polymer as the adhesive component has a number average molecular weight of 5,000 to 50,000, the gel fraction of the adhesive composition after crosslinking is less than 30% by weight. There is stickiness even after cross-linking. On the other hand, if it exceeds 80% by weight, the tackiness is lowered and the required adhesive strength may not be obtained.

  In addition, other resin components, such as a tackifier, may be contained in the adhesive, and it does not need to contain it. When the tackifier resin is blended with the pressure-sensitive adhesive, the moisture permeability decreases when the blending amount of the tackifier resin is increased. Therefore, the blending amount of the tackifier resin is preferably as small as possible. Specifically, the compounding amount of the tackifier resin is, for example, 50 parts by weight or less (preferably 30 parts by weight or less, more preferably 20 parts by weight or less, particularly 100 parts by weight of the alkenyl group-containing polyether polymer. It is desirable to select from the range of 10 parts by weight or less.

  In addition to the adhesive, various additives such as a solvent, a filler, a pigment, an ultraviolet absorber, an antioxidant, a nitrogen-containing silane compound, and a silicon compound may be blended. The pressure-sensitive adhesive preferably contains no solvent in order to prevent skin irritation caused by a solvent (organic solvent) remaining in a trace amount even after the drying step. That is, it is preferable to use a solventless adhesive as the adhesive.

  The thickness of the pressure-sensitive adhesive layer (thickness after drying) is, for example, about 50 to 200 μm (preferably 70 to 120 μm). If the thickness of the pressure-sensitive adhesive layer is thin, it will be difficult to obtain sufficient adhesive strength. On the other hand, if it is too thick, it will be difficult to obtain sufficient curing at the time of thermal curing, and the influence on cost needs to be considered. It is.

(Base material)
When the pressure-sensitive adhesive sheet for the inner surface of the paper diaper of the present invention is a pressure-sensitive adhesive sheet for the inner surface of a paper diaper with a substrate, the substrate (base material for the pressure-sensitive adhesive sheet) used for the pressure-sensitive adhesive sheet for the inner surface of the paper diaper is not particularly limited, Since a nonwoven fabric [especially, a polypropylene nonwoven fabric that is inexpensive and has a good texture (feel)] is generally used on the inner surface of the sheet, a nonwoven fabric (particularly, a polypropylene nonwoven fabric) is suitable as the base material for the pressure-sensitive adhesive sheet. Can be used. More specifically, as the base material for the pressure-sensitive adhesive sheet, for example, a known non-woven fabric such as a non-woven fabric made of polypropylene, a non-woven fabric made of nylon, or a non-woven fabric made of rayon can be used (non-woven fabric made of natural fibers, non-woven fabric made of synthetic fibers, etc.) In particular, a polypropylene non-woven fabric which is the same non-woven fabric as the non-woven fabric used on the inner surface of the paper diaper can be suitably used.

  Moreover, as a base material for adhesive sheets, the nonwoven fabric formed with the fiber (fiber substance) which has a polyacrylic acid sodium salt as one component or a main component (it may be called a "polyacrylic acid sodium salt fiber type nonwoven fabric"). ) Can also be used. Such a polyacrylic acid sodium salt fiber non-woven fabric can exhibit high water absorption and high water absorption. Therefore, when using a poly (sodium acrylate) non-woven fabric, the pressure-sensitive adhesive layer permeates moisture generated by perspiration, and the poly (sodium acrylate) non-woven fabric absorbs this moisture. The Therefore, moisture due to perspiration is absorbed by the polyacrylic acid sodium salt fiber-based nonwoven fabric through the adhesive layer, so that the effect of further suppressing or preventing skin stuffiness and further preventing or preventing skin irritation and redness. Played.

  As such a polyacrylic acid sodium salt fiber non-woven fabric, for example, trade name “BEL OASIS” (manufactured by Kanebo Gosei Co., Ltd., polyacrylic acid sodium salt polymer) is commercially available.

  In the nonwoven fabric, the fiber diameter, fiber length, basis weight, etc. are not particularly limited. A nonwoven fabric may be comprised only from 1 type of fiber, and may be comprised combining multiple types of fiber.

  Moreover, as a base material for adhesive sheets, as base materials other than a nonwoven fabric, the base materials by fibers, such as a cloth or a knitted fabric base material and a textile fabric base material, can also be used, for example.

  The thickness in particular of the base material for adhesive sheets is not restrict | limited, For example, it is about 10-500 micrometers (preferably 12-200 micrometers, More preferably, it is about 15-100 micrometers). The base material for pressure-sensitive adhesive sheets may have either a single layer or a multilayer.

  In addition, in order to improve anchor property with an adhesive, the primer may be apply | coated to the surface (adhesive layer formation surface) by the side of the adhesive layer of the base material for adhesive sheets. The adhesive sheet substrate may be subjected to various treatments such as back treatment and antistatic treatment as necessary.

(Production method)
The pressure-sensitive adhesive sheet for the inner surface of the paper diaper of the present invention has at least the pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer can be formed on a predetermined surface using a known or common coating method. Specifically, as an adhesive coating method, an appropriate coating method such as a roll coating method or a die coating method can be selected, but a comma reverse coating method, a melt blow or a curtain spray method are preferable, and a comma reverse method is particularly preferable. The coating method and curtain spray method are most suitable.

  When the curtain spray method is used, a pressure-sensitive adhesive can be applied in a fibrous form on a predetermined surface (for example, on a substrate or a release liner), and a porous pressure-sensitive adhesive layer (porous pressure-sensitive adhesive layer) can be formed. Can be formed. When the pressure-sensitive adhesive layer is a porous pressure-sensitive adhesive layer, sweat can be further permeable to moisture, and an effect of further preventing skin irritation and redness can be achieved. At this time, the pressure-sensitive adhesive sheet for the inner surface of the paper diaper comprises a porous pressure-sensitive adhesive layer (such as a porous pressure-sensitive adhesive layer formed by applying a pressure-sensitive adhesive in the form of a curtain spray) and a water-absorbing nonwoven fabric or a hygroscopic nonwoven fabric (polyester). Water, such as sweat that has permeated through the porous pressure-sensitive adhesive layer, water-absorbing non-woven fabric or moisture-absorbing as a base material for the pressure-sensitive adhesive sheet. Can be absorbed by the conductive non-woven fabric, and as a result, further rash and redness can be prevented. In particular, when the pressure-sensitive adhesive sheet for the inner surface of a paper diaper is composed only of a porous pressure-sensitive adhesive layer (such as a porous pressure-sensitive adhesive layer formed by applying a pressure-sensitive adhesive in the form of a curtain by a curtain spray method), the porous pressure-sensitive adhesive sheet Since the agent layer can be applied directly to the inner surface of the paper diaper, sweat can be further permeated and absorbed by the paper diaper, and as a result, further rash and redness can be prevented. become.

  The pressure-sensitive adhesive layer is usually formed entirely on a predetermined surface of a base material or a release liner, but may be partially formed, for example, in stripes using stripe coating, It may be partially formed in the shape of dots using coating.

  The moisture permeability of the pressure-sensitive adhesive layer is as described above, regardless of the form of the pressure-sensitive adhesive layer, as described above, over the entire coated area of the substrate or release liner (for example, the entire surface of one side) Measured as moisture permeability when applied to a uniform or almost uniform thickness. Therefore, even if the pressure-sensitive adhesive layer is formed in a fiber shape, a stripe shape, or a dot shape, the moisture permeability of the pressure-sensitive adhesive layer is uniform or almost uniform over the entire coated area on the substrate using the same pressure-sensitive adhesive. It can be measured as an adhesive layer formed by coating.

  The pressure-sensitive adhesive layer is preferably formed by applying a solventless pressure-sensitive adhesive (pressure-sensitive adhesive containing no solvent). That is, the pressure-sensitive adhesive layer can be obtained in a solvent-free production process (solvent-free coating process).

[Paper diapers]
The paper diaper of the present invention (disposable diaper) is an inner surface of the paper diaper as an adhesive sheet that is fixed to the inner surface of the paper diaper so that the adhesive surface can be in direct contact with the skin of the wearer when the paper diaper is worn. A pressure-sensitive adhesive sheet is used. Such a paper diaper may be a so-called “paper diaper with tape” (or also referred to as “disposable diaper with tape”, “open-type disposable diaper”, “open-type disposable diaper”, etc.), or a pants-type disposable diaper. It may be. The paper diaper may be an adult paper diaper or an infant paper diaper, but an infant paper diaper is preferred.

  The site for fixing the adhesive sheet for the inner surface of the paper diaper to the paper diaper is not particularly limited as long as it is the inner surface of the paper diaper, but from the viewpoint of adhesion, leakage prevention, etc., the inner surface of the paper diaper, when the paper diaper is worn The part where the adhesive surface of the adhesive sheet for the inner surface of the paper diaper can directly contact the skin in at least one part selected from the back, waist, legs, abdomen and buttocks of the wearer wearing the paper diaper Is preferred. Specifically, when the adhesive sheet for the inner surface of a paper diaper is a paper diaper with a tape or a pants-type paper diaper, as shown in FIGS. 2 (a) and (b), the inner surface of the paper diaper with a tape is worn. The surface (adhesive surface) of the pressure-sensitive adhesive layer can be fixed in a form capable of directly contacting the wearer's skin at a site that contacts the back, waist, legs, abdomen, or buttocks of the wearer. .

  FIG. 2 is a schematic view showing an example of a paper diaper in which the adhesive sheet for the inner surface of the paper diaper of the present invention is fixed to the inner surface. In FIG. 2, 1 is an adhesive sheet for the inner surface of a paper diaper, 2 is a paper diaper with tape, 21 is an inner surface of the paper diaper 2 with tape, 22 is an outer surface of the paper diaper 2 with tape, 23 is a fastener tape, 24 is a receiving portion of the fastener tape 23, 2a is a back side portion of the paper diaper 2 with tape, 2b is a waist side portion of the paper diaper 2 with tape, 2c is a leg side portion of the paper diaper 2 with tape, 2d is a belly side portion of the paper diaper 2 with tape, and 2e is a paper diaper 2 with tape. 3 is a back side part of the pant-type paper diaper 3, 3 b is a waist side part of the pant-type paper diaper 3. 3c is a leg side part of the pants-type paper diaper 3, 3d is a ventral part of the pants-type paper diaper 3, and 3e is a bottom side part of the pants-type paper diaper 3. 2 to 3 show the paper diaper 2 with tape and the pants-type paper diaper 3 as viewed from the front, the bottom part 2e of the paper diaper 2 with tape and the bottom part 3e of the pant-type paper diaper 3 are Although it is shown in a small area because it is almost invisible, it includes the entire lower part of the back side of each paper diaper. Moreover, although not shown in figure, the sheet | seat diaper inner surface adhesive sheet 1 is being fixed to the both sides on the right and left sides (2e, 3e) of the inner surface of each paper diaper (2, 3), respectively.

  Thus, the adhesive sheet for inner surfaces of a paper diaper can be fixed to various parts of the inner surface of the paper diaper. At this time, the pressure-sensitive adhesive sheet for the inner surface of the paper diaper may be fixed to each part of the inner surface of the paper diaper, or one sheet of the pressure-sensitive adhesive sheet for the inner surface of the paper diaper may be fixed in a form in which each part is continuous. Specifically, when the paper diaper is, for example, a paper diaper with a tape, as shown in FIG. 2 (a), the adhesive sheet for the inner surface of the paper diaper is fixed to the back side portion and the waist side portion of the paper diaper. In this case, the adhesive sheet for the inner surface of the paper diaper may be fixed to each of the back portion and the waist portion of the inner surface of the paper diaper. Also, as shown in FIG. One sheet of adhesive sheet for the inner surface of the paper diaper may be fixed in a continuous form from the part to the other waist side part via the back side part.

  On the other hand, when the paper diaper is, for example, a pants-type paper diaper, when the adhesive sheet for the inner surface of the paper diaper is fixed to the back portion, the waist portion, and the ventral portion of the inner surface of the paper diaper, FIG. As shown in FIG. 4, the adhesive sheet for the inner surface of the paper diaper may be fixed to each of the back side portion, the waist side portion, and the abdominal side portion of the inner surface of the paper diaper. One adhesive sheet for the inner surface of the paper diaper may be fixed in a form of one circumference around the back side part, one waist side part, the abdominal side part and the other waist side part.

  3-4 is the schematic which shows the other example of the paper diaper by which the adhesive sheet for paper diaper inner surfaces of this invention is being fixed to the inner surface. In FIGS. 3-4, each code | symbol is the same as the above.

  Moreover, only one sheet of adhesive sheet for the inner surface of a paper diaper may be used for each part of the inner surface of the paper diaper, or two or more adhesive sheets for the inner surface of a paper diaper may be used. Of course, only one adhesive sheet for the inner surface of the paper diaper may be used on the inner surface of the paper diaper, or two or more adhesive sheets for the inner surface of the paper diaper may be used.

  In addition, when the adhesive sheet for the inner surface of the paper diaper is a base material-less type adhesive sheet for the inner surface of the paper diaper, the adhesive sheet for the inner surface of the paper diaper is attached to the inner surface of the paper diaper by sticking to the inner surface of the paper diaper using one adhesive surface. Can be fixed.

  On the other hand, when the pressure-sensitive adhesive sheet for the inner surface of the paper diaper is a pressure-sensitive adhesive sheet for the inner surface of the paper diaper with a base having both sides of the pressure-sensitive adhesive surface, the pressure-sensitive adhesive layer having moisture permeability or the alkenyl group-containing polyether polymer is used. The surface of the pressure-sensitive adhesive layer formed of the main pressure-sensitive adhesive is in a form that allows direct contact with the wearer's skin, and is applied to the inner surface of the paper diaper using the other pressure-sensitive adhesive layer. The inner surface adhesive sheet can be fixed to the inner surface of the paper diaper. At this time, the other pressure-sensitive adhesive layer may be a pressure-sensitive adhesive layer having moisture permeability or a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive mainly composed of the alkenyl group-containing polyether polymer. It may be an agent layer.

  In addition, when the pressure-sensitive adhesive sheet for the inner surface of a paper diaper is a pressure-sensitive adhesive sheet for the inner surface of a paper diaper with a base that has only one side of the pressure-sensitive adhesive surface, a fixing member such as a pressure-sensitive adhesive or an adhesive is used. By sticking the surface to the inner surface of the paper diaper, the adhesive sheet for the inner surface of the paper diaper can be fixed to the inner surface of the paper diaper.

  In the paper diaper of the present invention, the pressure-sensitive adhesive sheet for the inner surface of the paper diaper is fixed to the inner surface, so that the pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet for the inner surface of the paper diaper is in direct contact with the wearer's skin. Even if it is applied directly and a paper diaper is worn with excellent adhesion and leakage prevention, moisture caused by sweating is permeated to suppress or prevent stuffiness on the skin surface and to suppress or prevent skin irritation and redness. Therefore, it is very useful as a disposable diaper that can be worn with high adhesion and leakage prevention.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

(Example 1)
As a pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer of the inner surface of a paper diaper pressure-sensitive adhesive, a pressure-sensitive adhesive mainly composed of a polyether polymer having at least one alkenyl group in the molecule (this pressure-sensitive adhesive is solvent-free at room temperature) Product name “Syryl Adhesive” (manufactured by Kaneka Chemical Co., Ltd .; number average molecular weight 20000): 100 parts by weight of a curing agent (trade name “CR500” manufactured by Kaneka Chemical Co., Ltd.) ): A pressure-sensitive adhesive composition added with 1.3 parts by weight (sometimes referred to as “pressure-sensitive adhesive A”) was used.

  The pressure-sensitive adhesive A is spread on the separator by a comma direct coating method so that the thickness after drying is 100 μm to form a pressure-sensitive adhesive layer, and then thermally cured at about 130 ° C. for 3 minutes to form a pressure-sensitive adhesive sheet ( A pressure-sensitive adhesive sheet for the inner surface of a paper diaper; sometimes referred to as “pressure-sensitive adhesive sheet A”) was prepared.

  The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet A is passed from one waist side part to the back side part as shown in FIG. 5 on the inner surface of a commercially available paper diaper with tape (open type paper diaper) as shown in FIG. Then, the adhesive on the inner surface of the paper diaper is bonded to the other side of the lower waist side, the ventral region, and the two leg side portions with the non-woven polypropylene surface that is the inner surface of the paper diaper with tape. A paper diaper using the sheet was obtained.

  FIG. 5 is a schematic view showing the disposable diaper produced in Example 1. In FIG. 5, the respective symbols are the same as described above.

(Example 2)
In the same manner as in Example 1, the pressure-sensitive adhesive A was prepared, and using the pressure-sensitive adhesive A, a pressure-sensitive adhesive sheet (pressure-sensitive adhesive sheet A) was produced in the same manner as in Example 1.

  The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet A is placed on the inner surface of a commercially available pants-type paper diaper as shown in FIG. 6, as shown in FIG. 6, the back side part, one waist side part, the ventral side part and the other side. A paper diaper using an adhesive sheet for the inner surface of a paper diaper is obtained by pasting together a non-woven fabric surface made of polypropylene, which is the inner surface of a pants-type paper diaper, on a region around the waist around the waist side region and the two leg side regions. It was.

  FIG. 6 is a schematic view showing a disposable diaper produced in Example 2. In FIG. 6, each symbol is the same as described above.

(Comparative Example 1)
As an adhesive, styrene-isoprene-styrene block copolymer (SIS; about 20% by weight of styrene content): 100 parts by weight of hydrogenated terpene resin (trade name “Clearon P-105” manufactured by Yasuhara Chemical Co .; tackifying resin): 100 parts by weight, paraffin oil (trade name “PW-90” manufactured by Idemitsu Petroleum Co., Ltd .; softener): 30 parts by weight, and titanium white: 20 parts by weight as a pigment were added and mixed (“Adhesive B” )).

  The pressure-sensitive adhesive B is applied onto the separator by a hot melt coating method so as to have a thickness of 100 μm to form a pressure-sensitive adhesive layer, and a pressure-sensitive adhesive sheet (sometimes referred to as “pressure-sensitive adhesive sheet B”). Produced.

  The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet B is placed on the inner surface of a commercially available tape-like paper diaper as shown in FIG. 5 from one waist side part to the other waist part as shown in FIG. Adhesive sheet for inner surface of paper diaper was used by pasting together the non-woven fabric surface made of polypropylene which is the surface of the inner surface of the paper diaper with tape on the site continuous to the side site, the ventral site and the two leg side sites I got a paper diaper.

(Comparative Example 2)
A commercially available pants-type disposable diaper as shown in FIG. 6 was used as it was.

(Evaluation)
About the paper diapers obtained in Examples 1 and 2 and Comparative Examples 1 and 2, the following feeling test is performed, and when the paper diaper is worn, the paper diaper is worn and used (in use). The feeling at the time of evacuation at the time of escaping the worn paper diaper was evaluated.

(Feeling test)
Five adult men and women selected at random were asked to wear the paper diapers obtained in Examples 1 and 2 and Comparative Examples 1 and 2, and the feeling when wearing the paper diapers, wearing the paper diapers The feel during use (during use) and the feel when leaving the disposable diaper are evaluated with the feeling. The feel of was evaluated. The evaluation results are shown in Table 1.
Evaluation criteria ○: All 5 out of 5 people rated it as having a good touch or no problem ○ △: 4 or more of 5 people rated it as having a good touch or no problem △: 2 or more out of 5 people had a problem It was evaluated.

(Measurement test of moisture permeability of adhesive layer)
About the adhesive layer by the adhesive A used in Examples 1-2, and the adhesive layer by the adhesive B used in the comparative example 1, the moisture permeability was measured with the measuring method of the moisture permeability of the following adhesive layer. However, the moisture permeability of the adhesive layer by the adhesive A was 1300 g / m ² · day, and the moisture permeability of the adhesive layer by the adhesive B was 70 g / m ² · day.
(Measurement method of moisture permeability of pressure-sensitive adhesive layer)
The adhesive is applied to the entire surface of the application area on the separator using an applicator, dried and crosslinked, and after forming an adhesive layer having a thickness of 100 μm (thickness after drying), the adhesive The layer is transferred to one side of a nylon nonwoven fabric (trade name “ELTAS” manufactured by Asahi Kasei Corporation; basis weight 40 g / m ² ) to produce an adhesive sheet. This pressure-sensitive adhesive sheet is placed on the upper surface of a glass cup (height 40 mm and inner diameter 40 mmφ) containing 20 g of water with the pressure-sensitive adhesive layer on the bottom, and the product name “No. 51” (Nitto) Affixed to a glass cup using a vinyl tape manufactured by Denko Co., Ltd. Thereafter, the glass cup covered with the pressure-sensitive adhesive sheet is placed in a constant temperature and humidity chamber at 40 ° C. and 30% RH for 20 minutes, taken out, weighed, and this weight is defined as the initial weight (W _O ). Further, after that, the sample was again placed in a constant temperature and humidity chamber at 40 ° C. and 30% RH, taken out after 4 hours, measured for weight (W _H ), and based on the following formula (a), the moisture permeability ( g / m ² · day) is calculated.
Moisture permeability = [(W _O −W _H ) × 24] / [(0.02) ² × π × 4] Formula (a)
[In the formula (a), the unit of moisture permeability is g / m ² · day. W _O : initial weight, W _H : weight after 4 hours. π is 3.14]

As described above, when the paper diaper according to the example is used, even when the adhesive sheet for the inner surface of the paper diaper fixed to the paper diaper is directly attached to the skin, the stuffy skin surface is suppressed or prevented, and skin irritation and redness are effectively prevented. Can be suppressed or prevented. This seems to be because the moisture permeability of the pressure-sensitive adhesive used in the examples is 800 g / m ² · day or more.

  Further, in the examples, an adhesive mainly composed of a polyether polymer having at least one alkenyl group in the molecule is used, so that it can be directly applied to the skin with excellent adhesiveness. In addition, since the pressure-sensitive adhesive does not contain a tackifier resin or a solvent (particularly an organic solvent), adverse effects on the skin can be minimized.

It is the schematic which shows the measuring method of the water vapor transmission rate of an adhesive layer. It is the schematic which shows an example of the paper diaper by which the adhesive sheet for paper diaper inner surfaces of this invention is being fixed to the inner surface. It is the schematic which shows the other example of the paper diaper by which the adhesive sheet for paper diaper inner surfaces of this invention is being fixed to the inner surface. It is the schematic which shows the other example of the paper diaper by which the adhesive sheet for paper diaper inner surfaces of this invention is being fixed to the inner surface. It is the schematic which shows the paper diaper produced in Example 1. FIG. It is the schematic which shows the paper diaper produced in Example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Adhesive sheet for inner side of paper diaper 2 Paper diaper with tape 21 Inner surface of paper diaper 2 with tape 22 Outer surface of paper diaper 2 with tape 23 Fastener tape 24 Receiving part of fastener tape 23 2a Back side part of inner side of paper diaper 2 with tape 2b Paper diaper 2 with tape 2c Leg side part of the inner surface of the paper diaper 2 with tape 2d Ventral part of the inner surface of the paper diaper 2 with tape 2e Bottom part of the inner surface of the paper diaper 2 with tape 3 Pant type paper diaper 31 Inner side of the pant type paper diaper 3 32 Outer surface of the pants-type paper diaper 3 3a Back side portion of the inner surface of the pants-type paper diaper 3 3b Waist side portion of the inner surface of the pants-type paper diaper 3 3c Leg portion of the inner surface of the pants-type paper diaper 3 3d Part 3e Bottom side part of the inner surface of the pants-type disposable diaper 3 4 Adhesive sheet 4a Chakuzaiso 4b nylon nonwoven 5 glass cup 5a open mouth of a glass cup 5 (top)
6 Water

Claims (8)

A pressure-sensitive adhesive sheet that is used by being fixed to the inner surface of a paper diaper in a form that allows the surface of the pressure-sensitive adhesive layer to be in direct contact with the skin of the wearer when the paper diaper is worn, and the moisture permeability (temperature) of the pressure-sensitive adhesive layer 40 ° C., humidity of 30% RH, thickness 100μm of the pressure-sensitive adhesive layer), the pressure-sensitive adhesive sheet for a disposable diaper inner surface, characterized in that at 800g / m ² · day or more. A pressure-sensitive adhesive sheet that is used by being fixed to the inner surface of a paper diaper in a form that allows the surface of the pressure-sensitive adhesive layer to be in direct contact with the skin of the wearer when the paper diaper is worn, wherein the pressure-sensitive adhesive layer is in the molecule A pressure-sensitive adhesive sheet for the inner surface of a disposable diaper, characterized by comprising a pressure-sensitive adhesive mainly comprising a polyether polymer having at least one alkenyl group. The pressure-sensitive adhesive sheet for the inner surface of a disposable diaper according to claim 2, wherein the polyether polymer has a number average molecular weight of 5,000 to 50,000. The pressure-sensitive adhesive layer according to any one of claims 1 to 3, wherein the pressure-sensitive adhesive layer is a porous pressure-sensitive adhesive layer. The pressure-sensitive adhesive sheet for an inner surface of a disposable diaper according to claim 4, wherein the porous pressure-sensitive adhesive layer is formed by applying a pressure-sensitive adhesive in a fibrous form. The pressure-sensitive adhesive sheet for an inner surface of a paper diaper according to any one of claims 1 to 5, wherein the pressure-sensitive adhesive layer is formed by applying a solventless pressure-sensitive adhesive. The pressure-sensitive adhesive sheet is a paper diaper that is fixed to the inner surface in such a form that the surface of the pressure-sensitive adhesive layer can be in direct contact with the wearer's skin when the paper diaper is worn, and the pressure-sensitive adhesive sheet is the first aspect of the present invention. A paper diaper, which is the pressure-sensitive adhesive sheet for the inner surface of the paper diaper according to any one of items 6 to 6. When the pressure-sensitive adhesive sheet for the inner surface of a paper diaper is worn with a paper diaper, the surface of the pressure-sensitive adhesive layer may come into direct contact with the skin in at least one region selected from the back, waist, legs, abdomen and buttocks of the wearer 8. The disposable diaper according to claim 7, which is fixed to the inner surface in a possible form.

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