JP2008036198A - Briefs type throwaway diaper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a briefs type throwaway diaper which has a good appearance, is a good fit when worn, can be easily put on, and is free from the problem the an absorbent body separates during use. <P>SOLUTION: An outer wrapping material includes an abdomen side outer wrapping material 11A arranged on the abdomen side A in an absorbent body 10 and a back side outer wrapping material 11B arranged on a back side B. The abdomen side outer wrapping material 11A and the back side outer wrapping material 11B are joined together to form side sealing portion S, a waist opening portion 50 and leg opening portions 60. The abdomen side outer wrapping material 11A and the back side outer wrapping material 11B have a laminated structure of an outer layer sheet 12 made of an elastic sheet and an inner layer sheet 13 made of an elastic sheet. The outside layer sheet 12 and the inside layer sheet 13 are not joined together in the entire area or the most of the side sealing portions S, the waist opening portion 50 and the leg opening portions 60 with the exception of their respective peripheries. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pants-type disposable diaper.

  Elastic members made of thread rubber, flat rubber, or the like are arranged in an extended state at the waist opening or leg opening of the pant-type disposable diaper, thereby forming a stretchable waist gather or leg gather. In such a configuration, the diaper is fixed to the wearer's body by a portion where the elastic member exists. Therefore, the contraction force acts intensively on the site where the elastic member exists, and the trace of the elastic member, that is, the so-called rubber mark is easily attached to the wearer's body. Moreover, many wrinkles generate | occur | produce in waist gathers or leg gathers by the contraction force of an elastic member. As a result, the fit of diapers is limited.

  In a disposable diaper comprising an absorbent main body including an absorbent core and an outer packaging material joined to the non-skin contact surface side of the absorbent main body separately from the pants-type diaper having such a configuration, a diaper for a wearer For the purpose of improving the fit, there is also known one using an elastic sheet as an outer packaging material (see, for example, Patent Documents 1 and 2). According to such a disposable diaper, since it is not necessary to use a linear elastic member such as rubber thread in order to develop stretchability in the outer packaging material, the appearance and softness of the diaper before or during wearing is excellent. In addition, problems such as rubber marks at the time of wearing by a linear elastic body can be solved. However, in the disposable diaper having such a configuration, even if the outer packaging material has elasticity, the absorbent main body does not substantially have elasticity, so that the elasticity of the outer packaging material is hindered. For this reason, problems such as difficult to put on diapers and difficulty in fitting diapers to the body were likely to occur. Moreover, peeling of the outer packaging material and the absorbent main body was easy to occur.

Japanese Patent Laid-Open No. 3-205053 Japanese Utility Model Publication No. 4-32718

  Therefore, the objective of this invention is providing the underpants type disposable diaper which can eliminate the fault which the prior art mentioned above has.

The present invention comprises an absorbent main body including an absorbent core, and an outer packaging material joined to the non-skin contact surface side of the absorbent main body,
The outer packaging material includes a ventral outer packaging material disposed on the ventral side portion of the absorbent main body, and a backside outer packaging material disposed on the back side portion,
Both side edges of the ventral outer packaging material and the back outer packaging material are joined together to form a pair of side seal portions, a waist opening portion and a pair of leg opening portions,
Each of the ventral outer packaging material and the back outer packaging material has a structure in which an outer layer sheet made of a stretchable sheet and an inner layer sheet made of a non-stretchable sheet are laminated, and the outer layer sheet and the inner layer sheet are The above object is achieved by providing a pants-type disposable diaper that is not joined in the entire region or most of the portion excluding the peripheral portions of the side seal portion, the waist opening portion, and the leg opening portion.

  According to the present invention, there is provided a pants-type disposable diaper that has an excellent appearance, has good fit when worn, is easy to flake, and has no problems such as peeling of the absorbent main body and tearing of the absorbent main body during use. The

  Hereinafter, the underpants type disposable diaper of this invention is demonstrated, referring drawings based on the preferable one Embodiment. The disposable diaper 1 of the present embodiment is disposed between a liquid-permeable top sheet 2, a liquid-impermeable or water-repellent back sheet 3, and both sheets 2, 3, as shown in FIGS. A substantially vertically long absorbent main body 10 having a liquid-retaining absorbent core 4 and an outer packaging material 11 joined to the back sheet 3 side (non-skin contact surface side) of the absorbent main body 10 are provided. .

  In the unfolded state of the diaper 1, the outer packaging material 11 includes an abdominal side outer packaging material 11A disposed on the abdominal side portion A located on one end side in the longitudinal direction of the absorbent main body 10, and the other end portion in the longitudinal direction. It consists of two members with the back side outer packaging material 11B arrange | positioned at the back side part B located in the side. The ventral outer packaging material 11 </ b> A and the back outer packaging material 11 </ b> B have shapes that substantially correspond to the front and back bodies of the pants. The crotch part C is located between the ventral part A and the dorsal part B in the absorbent main body 10, that is, in the central part in the longitudinal direction. The side edges A1, A2 of the ventral outer packaging material 11A and the side edges B1, B2 of the back outer packaging material 11B are joined together, and the disposable diaper 1 is formed with a waist opening 5 and a pair of leg openings 6. ing. By this joining, a pair of side seal portions S, S are formed on the left and right side edges of the disposable diaper 1 to form a pants shape. For these bondings, for example, heat sealing, high frequency sealing, ultrasonic sealing, or the like is used.

  Thus, in the diaper 1 of the present embodiment, the outer packaging material is disposed only on the abdominal side A and the back side B, and no outer packaging material is present on the crotch C. Since the diaper 1 has such a structure, a material such as a sheet-like non-woven fabric as an outer packaging material and an adhesive for joining the material are not interposed in the crotch C, so that air permeability and moisture permeability can be obtained. An advantageous effect is exhibited.

  Moreover, in the crotch part C of the diaper 1 of this embodiment, when a wearer puts a leg in the leg opening part 6 of the diaper 1, the leg opening part 6 is expanded and leg part elastic members 61a and 61b are extended. In this case, the side cuff elastic member 81 is not expanded in the diaper width direction. This is because the leg elastic members 61a and 61b and the side cuff elastic members 81 are arranged as separate members. As a result, the leg opening 6 can be greatly expanded while the width of the crotch portion C is narrowed, and an advantageous effect is obtained that the diaper 1 is less likely to be caught by a part of the wearer's foot or leg. Furthermore, when pulling up the diaper 1 after putting a foot, the advantageous effect that the diaper 1 becomes difficult to catch on a wearer's foot | leg or a part of body is also show | played. That is, there is an advantageous effect that the diaper 1 can be easily worn.

  The top sheet 2, the back sheet 3 and the absorbent core 4 are each rectangular, and are integrated to form a vertically long absorbent main body 10. As the surface sheet 2, the back surface sheet 3, and the absorptive core 4, the thing similar to what was conventionally used for this kind of diaper can be used, respectively. For example, as the absorptive core 4, what is comprised from the particle | grains and fiber material of a superabsorbent polymer, and coat | covered with the tissue paper (not shown) can be used.

  As shown in FIG. 5, the absorbent core 4 in the present embodiment includes an hourglass-shaped central absorbent body 41 and a pair of side absorbent bodies 42, 42 provided symmetrically on both sides of the central absorbent body 41. is doing. The central absorbent body 41 and the pair of side absorbent bodies 42 are separated from each other at least at the crotch portion. One side in the longitudinal direction and the other part in the longitudinal direction of the side absorbent body 42 are connected to each other at one longitudinal part (abdominal side) and the other longitudinal part (back side) of the central absorbent body 41, respectively. Therefore, between the central absorbent body 41 and the pair of side absorbent bodies 42 and 42, cut-out portions 43 and 43 having a shape that is punched are formed. One part in the longitudinal direction, the central part in the longitudinal direction, and the other part in the longitudinal direction are each region when the absorbent core 4 is divided into three regions so as to be divided into approximately three equal parts in the longitudinal direction. When the absorptive core 4 has the separation part 43, the both-sides edge part of the absorptive core 4 will stand up easily. Moreover, since the width | variety of the absorptive core 4 whole will become narrow if the absorptive core 4 is pressed in the width direction, the shrinkage | contraction of the width direction of the outer packaging material 11 is hard to be inhibited. When both side edges of the absorbent core 4 stand up, the width of the absorbent main body 10 when the diaper 1 is viewed from the skin contact surface side with the waist opening 5 of the diaper 1 widened is reduced. This makes it easier to pass.

  The shape of the absorbent core 4 in plan view is not limited to the shape shown in FIG. 5. For example, the side absorbent body 42 is connected to the central absorbent body 41 only at one of the longitudinal direction one part or the longitudinal direction other part. The shape, the shape in which the side absorber 42 is not connected to the central absorber 41 (separated), or the shape not having the separation portion 43 may be used (none of which is shown).

  As shown in FIGS. 2 and 4, side cuffs 8 and 8 made of a liquid-resistant or water-repellent and breathable material are formed on the left and right sides of the absorbent main body 10 in the longitudinal direction. . In the vicinity of the free end of each side cuff 8, a side cuff elastic member 81 is arranged in an extended state. Accordingly, when the disposable diaper 1 assembled as shown in FIG. 1 is worn, the side cuff 8 is erected by contraction of the side cuff elastic member 81, and the liquid in the width direction of the absorbent main body 10 is raised. Is prevented from flowing out. As shown in FIGS. 3 and 4, the sheet material 82 for forming the side cuffs 8, 8 has a predetermined width portion 82 </ b> S on the outer side in the width direction of the absorbent main body 10, and the skin contact surface side of the back sheet 3. And is fixed between the absorbent core 4 and the back sheet 3.

  Each of the ventral outer packaging material 11A and the back outer packaging material 11B has a structure in which an outer layer sheet 12 made of an elastic sheet and an inner layer sheet 13 made of a non-elastic sheet are laminated. The outer layer sheet 12 forms the outer surface of the diaper. On the other hand, the inner layer sheet 13 is disposed on the inner surface side of the outer layer sheet 12. The stretchable sheet forming the outer layer sheet 12 only needs to have stretchability in at least the diaper width direction (the left-right direction in FIG. 2) when the diaper is in an unfolded state. The non-stretchable sheet that forms the inner layer sheet 13 does not have stretchability at least in the diaper width direction when the diaper is in a developed state. Details of the outer layer sheet 12 and the inner layer sheet 13 will be described later.

  In the disposable diaper 1 of this embodiment, as shown in FIG.3 and FIG.4, between the outer-layer sheet | seat 12 and the inner-layer sheet | seat 13 in each of the abdominal-side outer packaging material 11A and the back-side outer packaging material 11B, side seal part A1, A2, B1, and B2 are joined to each other by heat sealing, high frequency sealing, or ultrasonic sealing, and the peripheral edge 50 of the waist opening 5 and the peripheral edge 60 of each of the pair of leg openings 6 are hot melt type. They are joined together by adhesives 52 and 62 such as adhesives. And between the outer layer sheet | seat 12 and the inner layer sheet | seat 13 in each of the abdominal side outer packaging material 11A and the back side outer packaging material 11B is not joined in the most part except these parts.

  Specifically, between the outer layer sheet 12 and the inner layer sheet 13, the side seal portions A 1, A 2, B 1, B 2, the peripheral edge portion 50 of the waist opening 5, and the peripheral edge portions 60 of each of the pair of leg openings 6. The abdomen outer packaging material 11A and the back outer packaging material 11B are joined at the central part of the diaper width direction, and are not joined at other parts.

  Thus, by setting it as the structure which does not join between the outer layer sheet | seat 12 and the inner layer sheet | seat 13 in the wide range in 11A of ventral | abdominal outer packaging materials, and the back side outer packaging material 11B, these outer packaging materials 11A and 11B are adhesive agents. The hardened part can be minimized. As a result, the outer surface of the diaper and the inner surface of the outer packaging material 11A, 11B that is not covered with the absorbent main body 10 can be made soft and comfortable. Moreover, when a breathable sheet is used as the outer layer sheet 12 and the inner layer sheet 13, the breathability is maintained well, so that a diaper that is not stuffy can be provided. Furthermore, since the outer peripheral sheet 12 and the inner layer sheet 13 are joined to each other at the peripheral edge portions 50 and 60 of the waist opening 5 and the pair of leg openings 6, the elastic outer packaging material 11 </ b> A is formed at the waistline portion. , 11B can provide an appropriate fit.

  A plurality of waist elastic members 51 and 51 are arranged along the peripheral edge of the waist opening 5 at the peripheral edge 50 of the waist opening 5 in each of the ventral outer packaging material 11A and the back outer packaging material 11B. Yes. These waist elastic members 51 and 51 are fixed in an extended state between the outer layer sheet 12 and the inner layer sheet 13 via an adhesive 52.

  In addition, leg elastic members 61 a and 61 b are arranged along the peripheral edge of the leg opening 6 on the peripheral edge 60 and 60 of the leg opening 6 in the ventral outer packaging material 11 </ b> A and the back outer packaging material 11 </ b> B. Yes. These leg elastic members 61 a and 61 b are fixed in an extended state between the outer layer sheet 12 and the inner layer sheet 13 via an adhesive 62. As the waist elastic member 51 and the leg elastic members 61a and 61b, elastic materials such as natural rubber, polyurethane resin, foamed urethane resin, and hot melt elastic member are made into a thread (thread rubber) or a belt (flat), respectively. Those formed into (rubber) are preferably used.

  In this way, thread-like or belt-like elastic members 51, 61a, 61b are sandwiched between the outer layer sheet 12 and the inner layer sheet 13 at the peripheral edge portions 50, 60 of the waist opening 5 and the pair of leg openings 6, respectively. By fixing in the state, the fit of these parts can be enhanced without being restricted by the expansion and contraction characteristics of the outer packaging materials 11A and 11B. Further, since the thread-like or belt-like elastic members 51, 61a, 61b can be fixed in a state of being sandwiched between the outer layer sheet 12 and the inner layer sheet 13, such an elastic member is fixed to the outer packaging material made of one sheet. Compared with the case where it does, it can prevent that an elastic member gives a wearer an uncomfortable feeling, and can also prevent that the external appearance of a diaper is deteriorated.

  In particular, with respect to the elastic members 61a and 61b arranged in the leg opening 6, the presence of the elastic members 61a and 61b in the leg opening 6 improves the fit and prevents the diaper 1 from slipping off. Can do. Further, since the leg elastic member does not exist in the crotch part C, the diaper 1 is more easily raised, and the rubber marks due to the elastic members 61a and 61b are hardly attached.

  Further, with respect to the elastic members 61a and 61b arranged in the leg opening 6, the portion located closest to the crotch portion is not substantially stretchable, so that the absorbent main body 11 is formed in the crotch portion. The width is prevented from being narrowed and liquid leakage is prevented. The part preferably includes at least a part of the elastic members 61 a and 61 b that overlaps the absorbent main body 11. In order to prevent the elastic members 61a and 61b from being substantially stretchable, for example, of the elastic members 61a and 61b held and fixed to the outer layer sheet 12 and the inner layer sheet 13 in an expanded state, the absorbent main body 11 and The overlapping portion may be cut by a large number of cutting portions so that stretchability does not appear in the portion.

  From the viewpoint of making the above-described effect more prominent, the width W3 of the leg elastic member 61a, 61b that is located closest to the crotch portion and does not substantially have stretchability (see FIG. 2) Is set equal to the width of the joint where the abdomen outer packaging material 11A and the back outer packaging material 11B are joined to the absorbent article 11 (the width W2 of the main body joint 15 described later, see FIG. 4), or It is preferable to set larger than that.

  In the disposable diaper 1 according to the present embodiment, the width of the region where the outer layer sheet 12 and the inner layer sheet 13 are joined to each other at the peripheral edge 50 of the waist opening 5 is the ventral outer packaging material 11A and the back outer packaging material 11B. For each, it is preferably within 70 mm from the peripheral edges 5a and 5b of the waist opening, and more preferably within 60 mm. The width of the region where the outer layer sheet 12 and the inner layer sheet 13 are joined to each other on the peripheral edge 60 of the leg opening 6 is the same as that of the leg opening 6 in each part of the ventral outer packaging material 11A and the back outer packaging material 11B. It is preferably within 50 mm from the peripheral edge, and more preferably within 30 mm.

  In addition, in the diaper width direction in each of the ventral outer packaging material 11A and the back outer packaging material 11B, the total length (L1 + L2) of the portion where the outer layer sheet 12 and the inner layer sheet 13 are not joined is the left and right side seal portions. The length La (Lb) between A1 and A2 is preferably 60% or more, more preferably 70% or more, and further preferably 75% or more.

  The area of the portion where the outer layer sheet 12 and the inner layer sheet 13 are not joined to each other in the ventral outer packaging material 11A and the back outer packaging material 11B is 60 with respect to the areas of the ventral side A and the back side B, respectively. It is preferably ~ 100%, more preferably 70-100%. Those satisfying this numerical value are referred to as “whole area or most part”.

  As shown in FIG. 2, the dimensions and ratios of the respective parts described in this specification are in a natural state (external force such as tension is applied) with the diaper in an unfolded state and the contraction force by the elastic members of the waist opening and the leg opening is released. The value measured in the state of not acting) or based on it. In addition, each measured value is measured based on the dimension of the outer layer sheet in a natural state.

  In the disposable diaper 1 of the present embodiment, the outer layer sheet 12 and the inner layer sheet 13 are joined to each other in the diaper width direction center of each of the abdominal outer packaging material 11A and the back outer packaging material 11B. Both sheets 12 and 13 are joined at a joint 14 having a predetermined width extending in the longitudinal direction of the diaper. Since both the sheets 12 and 13 are joined at the joint portion 14, the appearance before and during wearing of the diaper can be further improved. Further, when a disposal tape (not shown) is provided on the outer surface of the abdominal outer packaging material 11A or the back outer packaging material 11B, the disposal tape is firmly fixed by fixing the disposal tape to the central part in the diaper width direction. Can be fixed. The disposal tape is a tape that holds the diaper in a rolled state, and various conventionally known tapes can be used.

  When the back sheet 3 is provided with a design such as a pattern, characters, or other symbols due to the fact that the ventral outer packaging material 11A and the back outer packaging material 11B are joined at the joining portion 14, the outer side of the diaper Therefore, there is an advantage that the design can be clearly seen. The width W1 of the joint portion 14 between the outer layer sheet 12 and the inner layer sheet 13 at the central portion in the diaper width direction of the ventral outer packaging material 11A and the back outer packaging material 11B is 0 to 40% of the width W of the absorbent main body 10. It is preferable that it is 0 to 30%. If the width W1 of the joint portion 14 is within 40% of the width W of the absorbent main body 10, inhibition of stretchability is unlikely to occur.

  As for the absorptive main body 10, in the part except the both ends of the longitudinal direction, as shown in FIG.3 and FIG.4, only the center part of the width direction is 11A of stomach side outer packaging materials and the backside packaging material 11B by the main body junction part 15, respectively. The inner layer sheet 13 is joined. In a state where the ventral outer packaging material 11A is contracted, the ratio of the total area T2 of the joining portion of the absorbent main body 10 and the ventral outer packaging material 11A to the area T1 of the absorbent main body 10 facing the ventral outer packaging material 11A. T2 / T1 is preferably 0.6 or more, particularly preferably 0.65 or more. Similarly, in a state where the back side outer packaging material 11B is contracted, the area T1 ′ of the surface opposite to the back side outer packaging material 11B in the absorbent main body 10 is a joint portion between the absorbent main body 10 and the back outer packaging material 11B. The ratio T2 ′ / T1 ′ of the total area T2 ′ is preferably 0.6 or more, particularly preferably 0.65 or more. By doing in this way, peeling of the absorptive main body 10 during mounting | wearing of the diaper 1, or destruction becomes difficult to occur. T2 / T1 and T2 '/ T1' may be the same or different. The upper limit value of T2 / T1 and T2 '/ T1' is most preferably 1.

  The width W1 of the joint portion 14 between the outer layer sheet 12 and the inner layer sheet 13 in the diaper width direction center of each of the ventral outer packaging material 11A and the back outer packaging material 11B is 0 to 40% of the width W of the absorbent main body 10. It is preferable that it is 0 to 30%. By making it within this range, the stretchability is hardly inhibited.

  The main body bonding portion 15 is in the form of a band extending in the longitudinal direction, and one main body bonding portion 15 is provided at the central portion in the diaper width direction. The width W2 of the main body joint portion 15 is preferably 70% or more of the width W on the non-skin contact surface side of the absorbent main body 10 in each of the abdominal side A and the back side B, and is 75% or more. More preferably. By doing in this way, peeling of the absorptive main body 10 during mounting | wearing of the diaper 1, or destruction becomes difficult to occur.

  In the present invention, in the state where the side seal portion S is separated and the ventral outer packaging material 11A and the back outer packaging material 11B are deployed, the substantial width of the inner layer sheet 13 is the width of the outer layer sheet 12 in a contracted state. Is wider than. That is, in the state in which the ventral outer packaging material 11A and the back outer packaging material 11B are deployed, the outer layer sheet 12 is in a contracted state due to its contraction force, but the inner layer sheet 13 is made of a non-stretchable sheet, and thus has a width. Almost no narrowing. Therefore, the inner layer sheet 13 is loosened in the width direction with respect to the outer layer sheet 12. Such a slackened inner layer sheet 13 is virtually separated from the outer layer sheet 12, and the width of the inner layer sheet 13 when the slackness of the inner layer sheet 13 is eliminated is defined as “substantial width of the inner layer sheet 13”.

  The substantial width of the inner layer sheet 13 is preferably 1.3 to 4.0 times, more preferably 1.5 to 3.0 times the width of the outer layer sheet 12 in a contracted state. The ventral outer packaging material 11 </ b> A and the back outer packaging material 11 </ b> B having such a configuration can be manufactured by, for example, a manufacturing method described later.

  In the pants-type disposable diaper 1 of the present embodiment configured as described above, the inner layer sheet 13 is substantially in a state where the side seal portion S is separated and the abdominal outer packaging material 11A and the back outer packaging material 11B are deployed. The width is wider than the width of the contracted outer layer sheet 12. Due to this and the fact that the outer layer sheet 12 of the outer packaging material 11A, 11B is formed from an elastic sheet, the appearance and fit of the diaper when worn are improved. Further, since the inner layer sheet 13 of the abdominal outer packaging material 11A and the back outer packaging material 11B is formed of a non-stretchable sheet, even if the abdominal outer packaging material 11A and the back outer packaging material 11B extend in the width direction during use. The inner layer sheet 13 is slack, and the absorbent main body 10 is peeled off from the abdominal outer packaging material 11A and the back outer packaging material 11B, and problems such as tearing of the abdominal outer packaging material 11A and the back outer packaging material 11B hardly occur. Further, the skin contact surface side of the ventral outer packaging material 11A and the back outer packaging material 11B has good tactile sensation and texture, and is excellent in softness.

  In the ventral outer packaging material 11A and the back outer packaging material 11B, the outer layer sheet 12 made of a stretchable sheet and the inner layer sheet 13 made of a non-stretchable sheet are hardly adhered to each other. There is little influence, and thereby the stretchability of the ventral outer packaging material 11A and the back outer packaging material 11B is good. Further, when the outer layer sheet 12 of the ventral outer packaging material 11A and the back outer packaging material 11B is released from the extended state, the absorbent main body 10 does not shrink accordingly, so that the diaper has an excellent appearance. Become. And the absorptive performance of the absorptive main body 10 can be maintained. Therefore, even if the width W2 of the main body joint portion 15 is set wide, the stretchability in the width direction of the abdominal outer packaging material 11A and the back outer packaging material 11B is not inhibited.

  Next, the outer layer sheet 12 and the inner layer sheet 13 used for the ventral outer packaging material 11A and the back outer packaging material 11B of the diaper 1 of the present embodiment will be described. The outer layer sheet 12 has elasticity as described above. “Stretchability” refers to an extensible sheet (a sheet that extends more than twice in length) having a maximum elongation of 100% or more in at least one direction and an elongation in one direction having a maximum elongation of 100% or more. It means that the elongation recovery rate (elongation recovery rate at 100% elongation) when stretched to 100% and then contracted is at least 70% or more. In the case of an elastic sheet having a plurality of directions having a maximum elongation of 100% or more, the elongation recovery rate may be 70% or more in only one of the directions.

  The outer layer sheet 12 can extend larger in the diaper width direction than in the diaper longitudinal direction (vertical direction in FIG. 2). More specifically, in the diaper width direction, it stretches greatly and contracts after stretching (maximum elongation of 100% or more and elongation recovery rate of 70% or more), but in the diaper longitudinal direction, it stretches only slightly (for example, , Maximum elongation of 50% or less).

The elongation recovery rate of the elastic sheet is measured by the following measuring method.
[Method for measuring elongation recovery rate]
A sample piece of an elastic sheet having a length of 50 mm and a width of 25 mm is prepared, and the sample piece is fixed at a chuck interval K0 using a tensile tester ("Tensilon" RTC-1150A manufactured by Orientec Co., Ltd.) and 300 mm / min. After stretching to 100% stretched length K2 (K2 = K0 × 2) at the same speed, after starting to return at the same speed as the tensile speed, the length of the sample piece was restored after stretching. The length is K1. The elongation recovery rate at 100% elongation is calculated from the following equation.
Elongation recovery rate at 100% elongation (%) = [(K2−K1) / (K2−K0)] × 100

  As the stretchable sheet forming the outer layer sheet 12, various sheets having stretchability can be used. For example, the outer layer sheet 12 is preferably formed of a nonwoven fabric made of thermoplastic fibers from the viewpoint of improving air permeability. In addition, the outer layer sheet 12 is preferably made of a laminated sheet from the viewpoint of improving the texture, and at least the layer on the non-skin contact surface side is formed of an air-through nonwoven fabric. An elastic sheet made of elastic fiber (elastomer) having elasticity is generally not preferable from the viewpoint of texture because it gives a slimy feeling when touched.

  More specifically, as the stretchable sheet forming the outer layer sheet 12, for example, (1) a sheet in which a stretchable fiber layer is integrated on both sides or one side of an elastic fiber layer, and (2) a net-like sheet Preferably, a sheet in which stretchable fiber layers are integrated on both sides or one side of the elastic sheet, and (3) a sheet in which stretchable fiber layers are integrated on both sides or one side of the elastic film are preferably used. Can do. Examples of the method of integrating the elastic fiber layer and the extensible fiber layer include, for example, laminating them and hydroentangled them, or entangled fibers by air-through, etc., heat embossing, adhesive, ultrasonic bonding, etc. The method of letting it be mentioned.

  As the sheet of (1), for example, (a) a substantially inelastic non-elastic fiber layer is disposed on at least one surface of the elastic fiber layer, and both fiber layers have a fiber form of the constituent fibers of the elastic fiber layer. In a state where the fibers are kept in contact with each other by thermal fusion at the intersection of the fibers, a part of the constituent fibers of the inelastic fiber layer has entered the elastic fiber layer and / or a part of the constituent fibers of the elastic fiber layer Examples include stretchable nonwoven fabrics that are in a state of entering into the inelastic fiber layer. Moreover, as said (1)-(3) sheet | seat, it has (b) the elastic layer which has elastic elasticity, and a substantially inelastic nonelastic fiber layer, and both the said layers are laminated | stacked on the thickness direction. A stretchable sheet obtained by stretching a partially bonded laminated sheet can be preferably used.

  The stretchable nonwoven fabric (a) will be described. At the interface between the elastic fiber layer and the non-elastic fiber layer and in the vicinity thereof, the intersection of the constituent fiber of the elastic fiber layer and the constituent fiber of the non-elastic fiber layer is heat-sealed, and it is bonded substantially uniformly over the entire surface. Has been. By joining all over, it is prevented that both layers are separated and a space is formed, and a stretchable nonwoven fabric having a multi-layer structure with a sense of unity, such as a single nonwoven fabric. "The state in which the constituent fibers of the elastic fiber layer maintain the fiber form" means that even if most of the constituent fibers of the elastic fiber layer are given heat, pressure, etc., the film or film-fiber structure A state that is not deformed. In the elastic fiber layer, the intersections of the constituent fibers are thermally fused in the layer. Similarly, in the non-elastic fiber layer, the intersection of the constituent fibers is thermally fused in the layer.

  When non-elastic fiber layers are arranged on both sides of the elastic fiber layer, at least one of the constituent fibers is in a state where a part of the constituent fibers enter the elastic fiber layer and / or one of the constituent fibers of the elastic fiber layer. The part is in a state of entering at least one of the inelastic fiber layers. In order to allow the constituent fibers of the non-elastic fiber layer to enter the elastic fiber layer and / or to allow the constituent fibers of the elastic fiber layer to enter the non-elastic fiber layer, the constituent fibers of the elastic fiber layer and the constituent fibers of the non-elastic fiber layer are changed. It is preferable that at least one of the non-elastic fiber and the elastic fiber is in a web state (a state where heat fusion is not performed) before the heat fusion treatment. From the viewpoint of allowing the constituent fibers to enter other layers, the fiber layer in the web state is preferable because the short fibers have a higher degree of freedom than the long fibers.

  Moreover, it is preferable to use the air-through method in order to allow the constituent fibers of the non-elastic fiber layer to enter the elastic fiber layer and / or to allow the constituent fibers of the elastic fiber layer to enter the non-elastic fiber layer. By using the air-through method, the constituent fibers can be made to enter the opposing fiber layer, and the constituent fibers can be easily made to enter from the opposing fiber layer. Further, by using the air-through method, it becomes easy to allow the constituent fibers of the inelastic fiber layer to enter the elastic fiber layer while maintaining the bulkiness of the inelastic fiber layer. In particular, when the constituent fibers of the inelastic fiber layer are entangled with the constituent fibers of the elastic fiber layer, it is preferable that they are entangled only by the air-through method. In order to entangle the fibers by the air-through method, the gas blowing pressure, the blowing speed, the basis weight and thickness of the fiber layer, the conveyance speed of the fiber layer, etc. may be adjusted appropriately. Preferably it is done.

  In the hot air treatment (particularly, the air-through method), a part of the constituent fibers of the non-elastic fiber web enters the elastic fiber web, and at the same time, the constituent fibers of the non-elastic fiber web and / or the constituent fibers of the non-elastic fiber web are elastic. The constituent fibers of the fiber web are heat-sealed at their intersections. In this case, care should be taken so that the constituent fibers of the elastic fiber web do not become a film or film-fiber structure by the hot air treatment.

  The elastic fiber layer has a property that it can be stretched and contracts when tension is released. The elastic fiber layer preferably has a residual strain of 20% or less, particularly 10% or less when contracted after 100% elongation in at least one direction parallel to the surface. This residual strain value is preferably satisfied at least in the diaper width direction, and more preferably in both the diaper width direction and the diaper longitudinal direction.

  The elastic fiber layer is an aggregate of fibers having elasticity. Examples of a method for forming an elastic fiber include a melt blown method in which a molten resin is extruded from a nozzle hole, and the extruded molten resin is elongated with hot air to thin the fiber, and a semi-molten resin is cooled with cold air. There is also a spunbond method in which stretching is performed by a mechanical draw ratio. As a special method of the melt blown method, there is a spinning blow method in which the spun bond method is combined with the melt blown method.

  The elastic fiber layer may be in the form of a web or a nonwoven fabric made of elastic fibers. For example, it may be a web or a non-woven fabric formed by a spinning blow method, a spun bond method, a melt blow method, or the like. As the constituent fiber of the elastic fiber layer, for example, a fiber made of thermoplastic elastomer, rubber or the like can be used. In particular, fibers made from thermoplastic elastomers can be melt-spun using an extruder in the same way as ordinary thermoplastic resins, and the fibers thus obtained are easily heat-sealed. Is suitable for stretchable nonwoven fabrics.

  Examples of the thermoplastic elastomer include styrene elastomers such as SBS, SIS, SEBS, and SEPS, olefin elastomers, polyester elastomers, and polyurethane elastomers. These can be used individually by 1 type or in combination of 2 or more types.

  The inelastic fiber layer has extensibility but is substantially inelastic. As used herein, extensibility refers to the case where the constituent fiber itself is stretched, and even if the constituent fiber itself is not stretched, the two fibers that have been heat-sealed at the intersection of the fibers are separated from each other, or the fibers are heat-sealed. For example, the three-dimensional structure formed by a plurality of fibers may be structurally changed, the constituent fibers may be broken, and the entire fiber layer may be elongated.

  Examples of the fibers constituting the inelastic fiber layer include fibers made of polyethylene (PE), polypropylene (PP), polyester (PET or PBT), polyamide, and the like. The fibers constituting the inelastic fiber layer may be short fibers or long fibers, and may be hydrophilic or water repellent. Further, core-sheath type or side-by-side composite fibers, split fibers, irregularly shaped cross-section fibers, crimped fibers, heat-shrinkable fibers, and the like can also be used. These fibers can be used singly or in combination of two or more. The inelastic fiber layer can be a continuous filament or short fiber web or nonwoven.

  The stretchable sheet (b) will be described. This stretchable sheet is a laminate sheet in which substantially inelastic nonelastic fiber layers are laminated on both sides or one side of an elastic layer having elastic stretchability, and these are partially joined in a regular pattern. It can be obtained by stretching.

  This laminated sheet is manufactured as follows, for example. On the fiber web (first inelastic fiber layer) supplied from the card machine, an elastic fiber is supplied to form an elastic layer, on which another card machine or fiber web (second inelastic fiber layer) is formed. Fiber layer). The obtained laminated sheet having a three-layer structure is subjected to hot air treatment by an air-through dryer. The laminated sheet after the hot air treatment is subjected to hot embossing by an embossing device including an embossing roll in which embossing convex portions are regularly arranged on the peripheral surface and an anvil roll arranged to face the embossing roll. In addition, although the hot air process with a dryer is performed for the purpose of the heat | fever fusion | bonding of an elastic fiber and a non-elastic fiber, and the penetration | invasion of a fiber, this hot air process can also be abbreviate | omitted.

  The elastic layer preferably includes elastic fibers made of an elastic material. Examples of the elastic material include thermoplastic elastomers, rubbers, ethylene / propylene copolymers, and the like. Among these, thermoplastic elastomers are preferable because a fibrous elastic body can be formed relatively easily. Examples of the thermoplastic elastomer include polyurethane, styrene (SBS, SIS, SEBS, SEPS, etc.), olefin (copolymers such as ethylene, propylene, butene, etc.), vinyl chloride, and polyester. These can be used individually by 1 type or in combination of 2 or more types. The content of elastic fibers made of an elastic material in the elastic layer is preferably 50 to 100% by weight, particularly 75 to 100% by weight. As an elastic layer, it can replace with what consists of a fiber layer, and a film-like thing, a net-like thing, etc. can also be used. As the film or net forming material, the above-mentioned various elastic materials can be used.

  Next, the non-stretchable sheet forming the inner layer sheet 13 will be described. The non-stretch sheet refers to a sheet having an elongation recovery rate (%) measured by the above [Method for measuring elongation recovery rate] of 20% or less, or a sheet that breaks before 100% elongation. The non-stretchable sheet may or may not have extensibility, but the maximum elongation is preferably 90% or less.

  As the non-stretch sheet, a nonwoven fabric, a laminated material of a nonwoven fabric and a resin film, a porous film, and the like are preferable. The non-stretch sheet is preferably formed from a nonwoven fabric made of thermoplastic fibers from the viewpoint of improving air permeability and texture, and is formed from a water-repellent nonwoven fabric from the viewpoint of preventing excrement leakage. Are preferred.

  Further, as described above, the outer layer sheet 12 is generally lower in sheet strength than the inner layer sheet 13, and therefore, when used, the ventral outer packaging material 11A and the back outer packaging material 11B are torn or erroneous when a diaper is worn. The finger may break through the outer packaging material 11 with a finger. In order to prevent these, the sheet strength of the inner layer sheet 13 is preferably high, and the breaking strength in the diaper width direction and the diaper longitudinal direction is preferably 5 N / 25 mm or more. The breaking strength is measured by the following measuring method.

[Measurement method of breaking strength]
Prepare a sample with a length of 50 mm and a width of 25 mm, set the sample at 30 mm between the chucks, conduct a tensile test at a test speed of 300 mm / min, and use the maximum point load obtained at that time in the diaper width direction and diaper length. The breaking strength in the direction. The measurement is performed on five samples in each of the diaper width direction and the length direction, and the average value of the maximum point load is defined as the breaking strength.

  From the viewpoint of breaking strength, air permeability, and prevention of adhesive bleeding, it is preferable to use a nonwoven fabric obtained from a production method such as spunbond or heat roll as the inner layer sheet 13.

  Next, the suitable manufacturing method of the underpants type disposable diaper of the said embodiment is demonstrated. This manufacturing method is a method for continuously manufacturing the pants-type disposable diaper 1 of the embodiment. In this manufacturing method, as shown in FIG. 6, an outer layer sheet 12 expanded in the width direction is joined to an inner sheet 13 expanded in the width direction to form a ventral outer packaging material and a back outer packaging material. Then, the inner layer sheet 13 and the absorbent main body 10 in these outer packaging materials are joined by a main body joining portion (not shown) while maintaining the stretched state of the outer layer sheet 12 in these outer packaging materials, and then these outer packagings This is a method for manufacturing a pants-type disposable diaper in which the extension force of the material to the outer layer sheet 12 is released and the outer layer sheet 12 is contracted by the contraction force.

  This manufacturing method will be described in detail. The first belt-like sheets 120A and 120B are used as the raw fabric of the outer layer sheet 12, and the second belt-like sheets 130A and 130B are used as the raw fabric of the inner layer sheet 13. 1st strip | belt-shaped sheet | seat 120A, 120B is a strip | belt-shaped stretchable sheet which has a stretching property in the longitudinal direction. The second belt-like sheets 130A and 130B are belt-like non-stretchable sheets that do not substantially extend in the longitudinal direction.

  As 1st strip | belt-shaped sheet | seat 120A, 120B, the sheet | seat manufactured beforehand as a strip | belt-shaped sheet | seat which has a stretching property in a longitudinal direction outside a diaper manufacturing line can also be used, but in this manufacturing method, as shown in FIG. In addition, before the step of extending the first belt-like sheets 120A and 120B in the longitudinal direction, the non-stretchable belt-like sheets 120A ′ and 120B ′ are processed to obtain the first belt-like sheets 120A and 120B that exhibit the stretchability. Or a step of obtaining the first belt-like sheets 120A, 120B with improved stretchability by processing the low-stretch belt-like sheets 120A ′, 120B ′, and the first belt-like sheets 120A, A thus obtained. 120B is extended.

  In the present manufacturing method, the process for developing the stretchability or the process for improving the stretchability is an inline process using a pair of tooth groove rolls 71 and 71 in which teeth and grooves are engaged, as shown in FIG. More specifically, the belt-like sheets 120A ′ and 120B ′ in which the non-elastic fiber layers are integrated on both sides or one side of the elastic layer made of an elastic fiber layer, a net-like elastic sheet, an elastic film, or the like are used as a pair of tooth spaces. It is difficult to inhibit expansion and contraction of the elastic layer by biting into the rolls 71 and 71, thereby breaking the non-elastic fiber layer, extending the constituent fibers, or destroying the heat-sealing points between the fibers. The structure is changed. By changing the non-elastic fiber layer into a structure that hardly inhibits the expansion and contraction of the elastic layer, the first belt-like sheets 120A and 120B that exhibit or improve the stretchability are obtained.

  In this way, before the step of extending the first belt-like sheets 120A, 120B in the longitudinal direction, the non-stretchable or low-stretch belt-like sheets 120A ′, 120B ′ are processed inline to develop stretchability. Or by providing the process which raises a stretching property, the stretching property equivalent to the sheet | seat manufactured previously as a strip | belt-shaped sheet | seat which has a stretching property in a longitudinal direction outside a diaper manufacturing line is obtained. The width of the non-stretchable or low stretchable belt-like sheets 120A ′ and 120B ′ is set to 100 to 180% of the width of the first belt-like sheets 120A and 120B in consideration of the width shrinkage when processed inline. It is preferable to set it to 120 to 160%.

  In this manufacturing method, the first belt-like sheets 120A and 120B obtained as described above are stretched between the first nip roll 72 and the second nip roll 73 while being continuously conveyed. Each of the first nip roll 72 and the second nip roll 73 is composed of a pair of rolls, and the rotational speed (peripheral speed, sheet thickness) of the pair of rolls constituting the second nip roll 73 rather than the pair of rolls constituting the first nip roll 72. Driven to increase the feed rate). The pair of turning rolls 75a and 75a turns the first belt-like sheets 120A and 120B extended so as to join the second belt-like sheets 130A and 130B.

  Next, the second belt-like sheets 130A and 130B (inner layer sheet 13) expanded in the width direction and the first belt-like sheets 120A and 120B (outer layer sheet 12) expanded in the width direction are bonded and bonded together. . Since the second belt-like sheets 130A and 130B are non-stretchable sheets and the first belt-like sheets 120A and 120B are stretchable sheets, the second belt-like sheets 130A and 130B in a substantially non-stretched state, The first belt-like sheets 120A and 120B in a state where the shrinkage is developed are bonded together.

  In this manufacturing method, the first belt-like sheets 120A and 120B and the second belt-like sheets 130A and 130B are bonded between the first belt-like sheet 120A and the second belt-like sheet 130A as shown in FIG. The leg elastic member 61a and the waist elastic member 51 are sandwiched, and the leg elastic member 61b and the waist elastic member 51 are sandwiched between the first belt-like sheet 120B and the second belt-like sheet 130B. . Specifically, before superimposing the first belt-like sheet 120A and the second belt-like sheet 130A, either one of the first belt-like sheet 120A and the second belt-like sheet 130A or a predetermined part on the opposing surface of both are provided. The adhesive members 52 and 62 for fixing the elastic members are applied, and the elastic members 61a and 51 are sandwiched in an expanded state, and the first belt-like sheet 120A and the second belt-like sheet 130A are paired with a pair of nip rolls 74, 74, the elastic members 61a and 51 are fixed and the first belt-like sheet 120A and the second belt-like sheet 130A are joined. The same applies to the joining of the first belt-like sheet 120B and the second belt-like sheet 130B.

  The leg elastic members 61a and 61b are moved between the belt-like sheets 120A and 130A and between the belt-like sheets 120A and 130B while being swung by a known rocking guide in a direction perpendicular to the flow direction of the belt-like sheets 120A, 120B, 130A and 130B. Introduce. The turning roll 75b turns the conveying direction of the belt-like sheets 130A and 130B in a predetermined direction. By bonding the first belt-like sheets 120A and 120B and the second belt-like sheets 130A and 130B, the ventral outer packaging material continuum 110A and the back outer packaging material continuum 110B that are limited in the extent of extension in the longitudinal direction are obtained. The pair of turning rolls 75c and 75c turn the conveying direction of the ventral outer packaging material continuous body 110A and the back outer packaging material continuous body 110B in a predetermined direction.

  In this manufacturing method, the first belt-like sheets 120A and 120B are bonded to the second belt-like sheets 130A and 130B in a state where the first belt-like sheets 120A and 120B are elongated in the longitudinal direction. Is joined to the second belt-like sheets 130A and 130B in a state where the sheet is small (so-called width-reduced state). Therefore, the first belt-like sheets 120A and 120B used as the raw sheet of the outer layer sheet 12 take into account the width shrinkage due to the elongation, and the width before the longitudinal stretching (the same as the width in the non-stretched state) is the second belt-like sheet. The use of 100 to 140% of the width of the first belt-like sheets 120A and 120B after being joined to 130A and 130B means that the first belt-like sheets 120A and 120A are stretched in the longitudinal direction due to the width shrinkage caused by the stretching. From the viewpoint of preventing the width of 120B from becoming smaller than the width of the second belt-like sheets 130A and 130B, it is more preferable to use 110-130%. The elongation rate of the first belt-like sheets 120A and 120B when being joined to the second belt-like sheets 130A and 130B is, for example, 1.3 to 4.0 times, and more preferably 1.5 to 3.0 times.

  The pants-type disposable diaper 1 of the above embodiment is a conventional so-called cross-flow type pants-type disposable diaper except that the abdomen outer wrapping material continuum 110A and the back wrapping material continuum 110B obtained as described above are used. It can be manufactured in the same manner as the manufacturing method. For example, as shown in FIG. 6, the absorbent main body 10 obtained by cutting the absorbent main body continuous body 101 on the ventral outer packaging material continuous body 110 </ b> A and the back outer packaging material continuous body 110 </ b> B, respectively, with respect to the flow direction. After 90 degrees rotation, the adhesive is fixed intermittently. Further, the diaper continuous body 100 is obtained by removing the semicircular trim 111 for forming the leg opening by a rotary cutter, a laser cutter, or the like.

  The abdomen outer wrapping material continuous body 110A and the back wrapping material continuous body 110B are fixed to the absorbent main body 10 while maintaining the stretched state of the first belt-like sheets 120A and 120B. In other words, the absorbent main body 10 is fixed while maintaining the abdomen outer wrapping material continuous body 110 </ b> A and the back wrapping material continuous body 110 </ b> B so as not to shrink due to the contraction force of the first belt-like sheets 120 </ b> A and 120 </ b> B. Next, the side portions 12a and 12b of the abdomen outer wrapping material continuum 110A and the back side wrapping material continuum 110B in the diaper continuum 100 are folded back so as to cover both ends of the absorbent main body 10, and the absorbent main body 10 After fixing each side part 12a, 12b of 110A of belly side outer packaging material continuous bodies and 110B of back side outer packaging material continuous bodies to both ends, the diaper continuous body 100 is folded in two. Next, after forming the side seal portions S and S by heat seal, ultrasonic seal, high frequency seal or the like, or simultaneously with forming the side seal portions S and S, the pants type disposable diaper is cut. 1 can be obtained.

  For example, a method described in JP-A-4-166150 is used as a method of rotating the absorbent main body 10 by 90 degrees and intermittently fixing the absorbent main body 10 on the abdomen outer wrapping material continuous body 110A and the back side outer wrapping material continuous body 110B. Can do. The main body joint (not shown) for fixing the absorbent main body 10 to the ventral outer packaging material continuum 110A and the back outer packaging material continuum 110B includes the absorbent main body 10, the ventral outer packaging material continuum 110A and the back side. It can be applied to either one or both of the outer packaging material continuous body 110B.

  According to this embodiment, in this way, using the belt-like sheet having the stretchability in the longitudinal direction (first belt-like sheets 120A and 120B), good stretchability in the diaper width direction (left-right direction in FIG. 2). A pants-type disposable diaper having high finishing accuracy can be produced stably and continuously.

  That is, even if the first belt-like sheets 120A and 120B are sheets having excellent stretchability in the longitudinal direction, the first belt-like sheets 120A and 120B are obtained by pasting them together with the second belt-like sheets 130A and 130B that are substantially not stretched. The abdomen outer wrapping material continuum 110A and the back wrapping material continuum 110B that are formed are hardly stretched any more, or are slightly stretched when they are slightly stretched (so-called stretched growth). Therefore, if the abdomen outer wrapping material continuum 110A and the back wrapping material continuum 110B are transported with a certain degree of tension, the tension applied to the abdominal wrapping material continuum 110A and the back wrapping material continuum 110B during transportation. Even if fluctuates, fluctuations in the amount of elongation (elongation rate) of the ventral outer packaging material continuum 110A and the back outer packaging material continuum 110B are unlikely to vary.

  Therefore, for example, (b) a position where the trims 111A and 111B are cut out from the ventral outer packaging material continuous body 110A and the back outer packaging material continuous body 110B, and (b) the ventral outer packaging material continuous body 110A and the back outer packaging material continuous body 110B. The joint position when the absorbent main body 10 is joined, (c) the folding position when the diaper continuous body 100 is folded in half, (d) the ventral outer packaging material continuous body 110A fixed to the absorbent main body 10 and the back. Deviation may occur in the sealing position when forming a side seal S by sealing a predetermined portion of the side outer packaging material continuous body 110B, (e) the cutting position when cutting and dividing the diaper continuous body 100 into individual diapers, and the like. A pants-type disposable diaper that is prevented and has high finishing accuracy can be manufactured stably.

  In addition, by partially joining the first belt-like sheets 120A and 120B and the second belt-like sheets 130A and 130B, the abdomen outer wrapping material continuous body 110A and the back side derived from the stretchability of the first belt-like sheets 120A and 120B. Even if the stretchability of the outer wrapping material continuous body 110B is not impaired by the adhesive, or even if it is impaired, the degree is slight, so that the obtained disposable diaper 1 has the stretchability of the first belt-like sheets 120A and 120B. The abdomen outer wrapping material 11A and the back wrapping material 11B extend and contract well in the diaper width direction (left-right direction in FIG. 2), exhibiting a good fit to the wearer's waist, and preventing wearing and leakage prevention Excellent in properties.

  In the embodiment shown in FIG. 6, the first belt-like sheets 120 </ b> A and 120 </ b> B, which are the original fabric of the outer layer sheet 12, are stretched in the longitudinal direction, and then the original fabric of the inner layer sheet 13 remains long. Although it has joined to 2nd strip | belt-shaped sheet | seat 130A, 130B, methods other than this can also be employ | adopted. For example, the first belt-like sheets 120A and 120B are stretched in the width direction, intermittently cut, and then the short objects sequentially generated by the intermittent cutting are connected after being rotated 90 degrees, After forming a long sheet having elasticity in the direction (flow direction), it can be joined to the second belt-like sheets 130A and 130B. As a method (or mechanism) for rotating the short object by 90 degrees, a known method (or mechanism) can be used. Short objects are connected to each other by arranging adjacent short objects so that the end portions in the flow direction overlap each other, and processing such as heat sealing, ultrasonic sealing, and high frequency sealing is performed on the overlapping portions. Can be done.

  Also in such an embodiment, the first belt-like sheet is stretched between the first nip roll 72 and the second nip roll 73, and in this state, the first belt-like sheet is bonded and bonded to the second belt-like sheet. And by using the abdominal-side outer packaging material continuum and the back-side outer packaging material continuum obtained as described above, a pants-type disposable diaper can be stably and continuously produced as in the embodiment shown in FIG. .

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment. For example, in the above-described embodiment, the outer packaging material joined to the non-skin contact surface side of the absorbent main body is composed of the two members of the abdominal outer packaging material and the back outer packaging material. A crotch outer wrapping material may be further disposed on the crotch part located between the ventral part and the back part of the sex main body. In this case, the crotch outer packaging material may be integrated with the ventral outer packaging material and the back outer packaging material.

  Moreover, the coating shape of the joining part 14 which joins the outer layer sheet | seat 12 and the inner layer sheet | seat 13 in the part except the peripheral parts 50 and 60 of the side seal part S and the waist opening part 5 and the leg opening part 6 is the said implementation. It is not restricted to the coating shape in the form (the coating shape over the entire longitudinal direction at the center in the width direction). For example, the coating shape of the joint portion 14 may be a discontinuous (intermittent) coating shape in the width direction. As such a coating shape, as shown to Fig.7 (a), the coating shape in which the several strip-shaped junction part 14 extended in a longitudinal direction was arranged at predetermined intervals in the width direction is mentioned. Moreover, the coating shape of the junction 14 may be a discontinuous (intermittent) coating shape in the longitudinal direction. As such a coating shape, as shown in FIG. 7B, there is a coating shape in which a plurality of strip-shaped joint portions 14 extending in the width direction are arranged at predetermined intervals in the longitudinal direction. The band-shaped joint portion 14 extending in the width direction can be provided only in the central portion in the longitudinal direction or only at both ends in the longitudinal direction. Furthermore, the joining part 14 does not need to be provided.

  As shown in FIG. 8A, the coating shape of the joint portion 14 may be a spiral coating shape, or may be a coating shape (not shown) other than a belt shape. In the joint portion 14 having a coating shape other than the strip shape, as shown in FIG. 8B, the area of the strip region when the minimum stripable region including the joint portion 14 is virtually formed. Is the bonding area of the bonding portion. Even in the joint portion 14 having a coating shape other than the belt shape, the area of the portion where the outer layer sheet 12 and the inner layer sheet 13 are not joined to each other in the ventral side portion A and the back side portion B is as follows. It is preferable that it is 60 to 100% with respect to the area of each side part B, and it is more preferable that it is 70 to 100%.

  The coating shape of the main body joint portion 15 is not limited to the coating shape in the embodiment. FIGS. 9A and 9B are bottom views of another coating shape of the main body joint portion 15 as viewed from the side facing the outer packaging material 11 in the absorbent main body 10. As shown in FIG. 9A, the coating shape of the main body bonding portion 15 is one strip-shaped coating that extends in the longitudinal direction and is disposed at the center in the diaper width direction, and the longitudinal front and rear ends of the absorbent main body 10. It can be set as the shape which consists of an aggregate | assembly with the two strip | belt-shaped coatings extended in the width direction each distribute | arranged to the part. That is, the coating shape of the main body joint 15 shown in FIG. 9A is similar to the capital letter “I” of the alphabet. Further, the coating shape of the main body joint portion 15 may be a shape separated in the diaper width direction, for example, an aggregate of two strip-shaped coatings extending in parallel in the longitudinal direction as shown in FIG. 9B. It can be set as the shape which consists of.

  As shown in FIG. 10A, the coating shape of the main body joint portion 15 may be a spiral coating shape, or may be another coating shape (not shown) other than a belt shape. In the main body joint portion 15 having a coating shape other than the belt shape, as shown in FIG. 10B, the belt-like region when a belt-like region having the minimum area that can include the main body joint portion 15 is virtually formed. Is the bonding area of the main body bonding portion. Also in the main body joint portion 15 having a coating shape other than the belt shape, the absorbent main body 10 and the ventral side with respect to the area T1 of the surface of the absorbent main body 10 facing the ventral outer packaging material 11A in a contracted state. The ratio T2 / T1 of the total area T2 with the joint portion with the outer packaging material 11A is preferably 0.6 or more, particularly preferably 0.65 or more. Similarly, in a state where the back side outer packaging material 11B is contracted, the area T1 ′ of the surface opposite to the back side outer packaging material 11B in the absorbent main body 10 is a joint portion between the absorbent main body 10 and the back outer packaging material 11B. The ratio T2 ′ / T1 ′ of the total area T2 ′ is preferably 0.6 or more, particularly preferably 0.65 or more.

  Further, the joining by the joining portion 14 between the outer layer sheet 12 and the inner layer sheet 13 and the joining by the main body joining portion 15 between the absorbent main body 10 and the outer packaging material 11 are not limited to joining using an adhesive, and are generally performed by heat. It can also be achieved by bonding (embossing, ultrasonic sealing, etc.).

  Further, the joining or engaging position between the both side edges A1, A2 of the ventral outer packaging material 11A and the both side edges B1, B2 of the back outer packaging material 11B is not limited to the position just beside the body, but slightly forward or rearward of the body. It may be a close position.

  Further, on the non-skin contact surface side (outer layer sheet 12 side) of the stomach side outer packaging material 11A or the back side outer packaging material 11B of the disposable diaper 1 described above, it is disposed at a position overlapping with the joining portion 14 such as a hot melt adhesive. By fixing the tape, the disposable diaper 1 that can be disposed of in a compact manner while maintaining the stretchability of the disposable diaper 1 can be obtained.

  Further, when a crotch outer packaging material is disposed in the crotch part located between the abdominal part and the dorsal side part, leg leg elastic members are arranged in an extended state on the left and right side parts of the crotch outer packaging material. Then, the leg gathers may be formed by folding the both sides and fixing the leg elastic member. Alternatively, solid gathers may be arranged on the left and right sides of the crotch outer packaging material.

FIG. 1 is a perspective view showing an embodiment of a pants-type disposable diaper of the present invention. FIG. 2 is a plan view showing a developed state of the disposable diaper shown in FIG. 1. FIG. 3 is an exploded perspective view of the disposable diaper shown in FIG. 1. 4 is a cross-sectional view taken along line IV-IV shown in FIG. FIG. 5 is a plan view showing an absorbent core in the disposable diaper shown in FIG. 1. FIG. 6 is a perspective view showing an embodiment of a method for producing a pants-type disposable diaper of the present invention. Fig.7 (a) and FIG.7 (b) are typical top views which show the example of the coating shape of the junction part of an outer layer sheet and an inner layer sheet, respectively. FIG. 8A is a schematic plan view showing a spiral-shaped joint between the outer layer sheet and the inner layer sheet, and FIG. 8B is a schematic plan view used for explaining the joint area of the spiral-shaped joint. It is. Fig.9 (a) and FIG.9 (b) are typical bottom views which show the example of the coating shape of the main body junction part of an absorptive main body and an outer packaging material, respectively. FIG. 10A is a schematic bottom view showing a spiral-shaped main body joint between the absorbent main body and the outer packaging material, and FIG. 10B is a schematic diagram used for explaining the joint area of the spiral main body joint. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pants type disposable diaper 2 Top sheet 3 Back sheet 4 Absorbent core 5 Waist opening 6 Leg opening 10 Absorbent main body 11A Abdominal outer packaging material 11B Abdominal outer packaging material 12 Outer layer sheet 13 Inner layer sheet 15 Main body joint 100 Diaper continuous Body 110A Ventral outer packaging material continuum 110B Ventral outer packaging material continuum 120A, 120B First strip sheet 130A, 130B Second strip sheet

Claims (5)

An absorbent main body including an absorbent core, and an outer packaging material joined to the non-skin contact surface side of the absorbent main body,
The outer packaging material includes a ventral outer packaging material disposed on the ventral side portion of the absorbent main body, and a backside outer packaging material disposed on the back side portion,
Both side edges of the ventral outer packaging material and the back outer packaging material are joined together to form a pair of side seal portions, a waist opening portion and a pair of leg opening portions,
Each of the ventral outer packaging material and the back outer packaging material has a structure in which an outer layer sheet made of a stretchable sheet and an inner layer sheet made of a non-stretchable sheet are laminated, and the outer layer sheet and the inner layer sheet are The pants type disposable diaper which is not joined in the whole area or most part of the part except the peripheral part of each of the side seal part and the waist opening part and the leg opening part.   The pants-type disposable diaper according to claim 1, wherein a substantial width of the inner layer sheet is 1.3 to 4.0 times a width of the outer layer sheet in a contracted state. Both the ventral outer packaging material and the dorsal outer packaging material are joined to the absorbent main body at a band-shaped joint extending in the longitudinal direction of the absorbent main body,
In a state where the ventral outer packaging material is contracted, the total area T2 of the joining portion of the absorbent main body and the ventral outer packaging material with respect to the area T1 of the absorbent main body facing the ventral outer packaging material is The ratio T2 / T1 is 0.6 or more,
In a state where the backside outer packaging material is contracted, the total area T2 of the joining portion of the absorbent main body and the backside outer packaging material with respect to the area T1 ′ of the surface of the absorbent main body facing the backside outer packaging material. The pants-type disposable diaper according to claim 1 or 2, wherein the ratio T2 '/ T1' is 0.6 or more. The crotch outer wrapping material is further arranged on the crotch part located between the abdominal part and the back side part in the absorbent main body,
The pants-type disposable diaper according to any one of claims 1 to 3, wherein the crotch outer packaging material is joined and integrated with the ventral outer packaging material and the back outer packaging material. The underpants type disposable diaper in any one of Claim 1 thru | or 4 by which the elastic member is distribute | arranged to the leg opening part in the said stomach side outer packaging material and the said back side outer packaging material along this leg opening part.