CN102791237A

CN102791237A - Disposable diaper

Info

Publication number: CN102791237A
Application number: CN2012800002612A
Authority: CN
Inventors: 上田纯子; 菊池响; 大桥直人
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 2011-03-04
Filing date: 2012-03-02
Publication date: 2012-11-21
Also published as: AR088312A1; TWI603725B; JP2014506804A; TW201249410A; JP6025736B2; WO2012120864A1

Abstract

Embodiments of this invention provide a disposable diaper adapted to restrict a change in thickness of the core assembly due to absorption of bodily fluids. A core assembly (4) as a component of a fluid-absorbent structure (5) in a disposable diaper (1) includes fluff wood pulp fibers (41) and superabsorbent polymer particles (42) and is wrapped with wrapping sheets (44a, 44b). The core assembly (4) is formed in a region thereof facing a liquid-pervious bodyside liner (2) with a plurality of depressions (51).

Description

Disposable diaper

Technical field

The disclosure relates to polytype disposable diaper.

Background technology

Known disposable diaper has the liquid-absorbent structure, and this liquid-absorbent structure comprises wooden pulp fibers of fine hair (fluff wood pulp fiber) and the particulate mixture of superabsorbent polymer.

For example; The absorbent structure of disclosed disposable diaper comprises the mixture of superabsorbent polymer granule and the wooden pulp fibers of fine hair in JP 2002-315783A (PTL 1); Wherein, When measuring through the Vortex method, the superabsorbent polymer granule has the Liquid Absorption speed of 40g/g or higher Liquid Absorption rate and 20 seconds or shorter time.

About being used for the absorbent structure of disposable diaper etc., JP H6-503983A (PTL2) has instructed absorbent structure should be able to drain when taking place absorb body fluids at once ideally.Absorbent structure disclosed herein has used the absorber gellant; When in tea bag test (Teabag Test) down during this absorber gellant of test, this absorption gellant can be to absorb artificial urine at least about 40% absorbability as soon as possible in 10 seconds or shorter time.

One of the absorbent commodity of in JP 2009-61063A (PTL 3), describing is exemplified as disposable diaper, and the absorbent structure in this absorbent commodity comprises and guarantees the high superabsorbent polymer granule that passes through liquid speed, liquid absorption capacity and absorption speed.

Reference listing

Patent documentation

PTL?1：JP?2002-315783A

PTL?2：JP?H6-503983A

PTL?3：JP?2009-61063A

Summary of the invention

The problem that invention will solve

According to the inventor's discovery, the diaper that all has following liquid-absorbent structure all is easy to expand into rapidly unacceptable volume when absorbing moisture, and this liquid-absorbent structure comprises the superabsorbent polymer granule as the part of core assembly.The liquid-absorbent structure that expand into this state possibly excessively closely contact with the skin of user, and perhaps uncomfortable feeling is caused to user in the gap between the skin of possibility closed liquid absorbent structure and user therefore.Local and become significantly when being extruded between big and the shank of this part when the part of the liquid-absorbent structure in the crotch region of diaper at user, thus crotch region possibly expand undesiredly and makes outward appearance seem no good cake.Even the liquid-absorbent structure still has the ability of absorb body fluids, seen that mother of this undesired dilation also may judge by accident to changing a new diaper.

The scheme that is used to deal with problems

According to certain embodiments of the present invention, a kind of disposable diaper is provided, it has length direction and width, and said disposable diaper comprises:

Front waist region, rear waist region and the crotch region between said front waist region and said rear waist region; With

At least be formed at the liquid-absorbent structure of said crotch region, said liquid-absorbent structure comprises:

Core assembly, said core assembly are by comprising that the particulate liquid-absorbent mixtures of material of fine hair pulp fibers and superabsorbent polymer forms, and said core assembly is by parcel sheet material parcel; With

Cover the side liner of liquid permeability of the upper surface of said core assembly at least in part.

In this diaper, core assembly is formed with a plurality of recesses recessed on the thickness direction of said core assembly, and in said recess, said mixture and said parcel sheet material are bonded together through hot-melt adhesive;

In said recess, said core assembly have with non-recessed region in the corresponding thickness below 80% of thickness of said core assembly, said non-recessed region is limited to the outside of said recess and between adjacent said recess;

Each recess and near the distance of the center to center between the recess of this recess in the scope of about 2-14mm; And

Said superabsorbent polymer granule has the water absorption of not pressurizeing smaller or equal to 45ml/g that begins measurement in back 5 minutes at the water absorption test that do not pressurize, and has smaller or equal to water absorption under the load of 14g/g.

Description of drawings

Fig. 1 is the plane graph that the part of disposable diaper is dissectd.

Fig. 2 is the sectional view along the diaper of Fig. 1 of the line II-II intercepting of Fig. 1.

Fig. 3 is the ratio enlarged drawing that the annular region III among Fig. 1 is shown.

Fig. 4 is the sectional view along the diaper of Fig. 1 of the line IV-IV intercepting of Fig. 3.

Fig. 5 is the figure similar with Fig. 3, and it is exemplary to show an embodiment.

Fig. 6 is the figure similar with Fig. 1, its exemplary another embodiment that shows.

Fig. 7 is the figure similar with Fig. 4, its exemplary another embodiment that shows.

Fig. 8 is the exemplary figure that illustrates according to the distribution of the recess of another embodiment.

The specific embodiment

The details of the disposable diaper with preferred feature is according to certain embodiments of the present invention described below with reference to accompanying drawing.Each characteristic can be used separately or be used in combination with described other preferred features.

With reference to figure 1, diaper 1 comprises the back-sheet 3 of the side liner 2 of liquid permeability, non-liquid permeability and the liquid-absorbent core assembly 4 between element 2 and 3.The part of the lower surface of the part of the upper surface of the covering core assembly 4 of core assembly 4, side liner 2 and the covering core assembly 4 of back-sheet 3 jointly limits liquid-absorbent structure 5.Liquid-absorbent structure 5 is crossed crotch region 7 and is extended to front waist region 8 and rear waist region 9.In diaper 1, outer sheet 6 is laminated in the outer surface (see figure 2) of back-sheet 3.

Diaper 1 has length direction A and width B, and wherein crotch region 7 is limited at the mid portion on the length direction A, and front waist region 8 is limited at the place ahead of crotch region 7 and the rear that rear waist region 9 is limited at crotch region 7.Opposite ends on length direction A; The a plurality of front waist elastic components 11 that extend along width B and a plurality of back lumbar part elastic components 12 of extending along width B and are fixed between

element

2 and 3 under extended state between side liner 2 and back-sheet 3.

The both sides of diaper 1 on its width B are provided with the leakproof sheet material (containment sheet) 13 of A extension alongst.The inside edge 13a of each leakproof sheet material 13 is formed with sleeve pipe (sleeve) 14, elastic component 16 under extended state along its length A be fixed in the sleeve pipe 14.In addition, diaper 1 along its opposite edges edge 17 be provided with one or more under the extended state alongst A extend, be fixed on the leg elastic member 18 between the outer ledge 19 of back-sheet 3 and each leakproof sheet material 13 through the hot-melt adhesive (not shown).Rear waist region 9 is provided with band securing member 21 respectively at its opposite edges edge.Band securing member 21 is included in diaper 1 respectively and is through the fastening area 22 that user is suitable for removably being anchored on the target area (not shown) of the outer surface that is arranged at front waist region 8 on one's body the time.

The diaper 1 of structure is about the centre line C L symmetry by this way, and centre line C L is divided the size of diaper 1 on width B equally.The scope that the recess 51 that will describe below a plurality of points 23 expressions that illustrate on the side liner 2 of diaper 1 distributes.

With reference to Fig. 2, schematically show the configuration of each member, thereby can easily understand the overlapped mode of each member.With reference to figure 2, core assembly 4 is between side liner 2 and back-sheet 3.Core assembly 4 comprises the cotton paper (tissue paper) 44 of liquid-absorbent mixtures of material 43 and pack mixture 43, and wherein liquid-absorbent mixtures of material 43 comprises wooden pulp fibers 41 of fine hair and superabsorbent polymer granule 42 (for example seeing Fig. 4) at least.Cotton paper 44 for example comprises cotton paper 44a and cotton paper 44b.Mixture 43 can be engaged with each other through hot-melt adhesive HA1 with cotton paper 44.Core assembly 4 joins side liner 2 to and joins back-sheet 3 to through hot-melt adhesive HA3 through hot-melt adhesive HA2.Core assembly 4 forms with back-sheet 3 cooperations with side liner 2 has the liquid-absorbent structure 5 (for example seeing Fig. 4) of a plurality of recesses.Side liner 2 can be crossed the periphery of core assembly 4 with back-sheet 3 and stretch out, and the inner surface of these extensions is bonded together through hot-melt adhesive HA2 and HA3.The outer ledge 19 of each leakproof sheet material 13 joins side liner 2 to through hot-melt adhesive HA4.The inside edge 13a of each leakproof sheet material 13 locates to join to through the hot-melt adhesive (not shown) in the opposite end on length direction A the side liner 2 at front waist region 8 and rear waist region 9 places, but these inside edges 13a does not join the side liner 2 at crotch region 7 places to.Through this configuration, when diaper 1 is through user and elastic component 16 when shrinking on one's body, shown in dotted line among Fig. 2, liner 2 lifts inside edge 13a self from the side.

Outer sheet 6 can be laminated in the outer surface of back-sheet 3 through hot-melt adhesive HA5.

Although liquid-absorbent structure 5 as shown in fig. 1 is crossed crotch region 7 and extended to front waist region 8 and rear waist region 9, the length of liquid-absorbent structure 5 on length direction A can suitably shorten.For example, make liquid-absorbent structure 5 can only be present in crotch region 7, or only be present in crotch region 7 and front waist region 8, or only be present in crotch region 7 and rear waist region 9 thereby can shorten liquid-absorbent structure 5.

In diaper as illustrated in fig. 1 and 21, can be with non-woven fabrics as side liner 2.Non-woven fabrics can be processed by the thermoplastic synthetic fiber, for example ventilative non-woven fabrics, spun-bonded non-woven fabrics and SMS non-woven fabrics, and the SMS non-woven fabrics is made up of spun-bonded non-woven fabrics, melt spraying non-woven fabrics and spun-bonded non-woven fabrics.As an example of ventilative non-woven fabrics, polyethylene and polyacrylic conjugate fibre with fibre fineness (fiber fineness) of about 1-4 dtex (dtex) scope can be at about 10-35g/m ²The basic weight of scope (basis mass) uses down.The film of being processed by the thermoplasticity synthetic resin such as polyethylene film of the gauge that for example has about 5-20 micrometer range can be used as back-sheet 3.The outer surface that outer sheet 6 is used to prevent diaper 1 is as plastics, and makes outer surface as cloth.For realizing this purpose, by the fibre fineness with about 1-4 dtex scope and about 10-20g/m ²The non-woven fabrics that the thermoplasticity synthetic resin of the basic weight of scope is processed can be used as outer sheet 6.

The wooden pulp fibers 41 of fine hair of forming the mixture 43 in the core assembly 4 preferably has about 100-350g/m respectively with superabsorbent polymer granule 42 (see figure 4)s ²The basic weight of scope and be used to make mixture 43 can have preferably at about 300-600g/m ²Total basic weight of scope.The cotton paper of common use or exploitation optionally as the cotton paper 44 of pack mixture 43, for example, has at about 15-20g/m in the correlative technology field ²The cotton paper of the basic weight of scope can be used as the cotton paper 44 of pack mixture 43.

Leakproof sheet material 13 can comprise non-woven fabrics, and more preferably comprises by water-proofing treatment in advance and become to make the non-woven fabrics that has sufficient non-liquid permeability when the diaper 1 actual use.

With reference to figure 3 and 4, liquid-absorbent structure 5 is included on the thickness direction of core assembly 4 from the recessed a plurality of recesses 51 of side liner 2 and is limited to recess 51 outsides and the non-recessed region 52 between adjacent recess 51.

Although do not point out the flat shape of each recess 51 especially, Fig. 3 exemplarily shows the diameter D that recess 51 all has rounded bottom and about 1.5-5mm scope.In the recess of flat shape with non-circular shape, in preferably having, each recess is connected to the flat shape in the circle 56, and this circle 56 has preferred diameter E (see figure 5) in about 1.5-5mm scope.

" diameter " of the recess that here uses is meant the diameter of a circle that in the concave bottom place, connects flat shape.When recess had circular planar form, the diameter of recess was identical with the diameter D of circular planar form.

" distance of center to center " between two recesses that here use be meant the concave bottom place respectively in connect the distance between the center of circle of circle of flat shape.

In the recess of this flat shape with non-circular shape, in the flat shapes that are connected in the circle 56 preferably have 3 points.Although the distribution patterns of the recess 51 in the liquid-absorbent structure 5 is not pointed out especially yet; But; Therein among the distance L of the center to center between recess 51 and the contiguous two or more recesses 51, the distance L of minimum center to center is preferably in the about scope of 2-14mm.That is to say, one of them recess 51 and near the distance L of the center to center between the recess of this recess 51 preferably in the about scope of 2-14mm.Among these many recesses 51, if the distance L of center to center is big relatively less than the quantity of the recess of the vicinity of 2mm, then liquid-absorbent structure 5 may become really up to the mark and can not be out of shape smoothly.Be evenly distributed on the side liner 2 although recess 51 is exemplarily illustrated as, recess 51 also can be distributed at random.

With reference to figure 4, liquid-absorbent structure 5 comprises core assembly 4, cover the side liner 2 of the upper surface side of core assembly 4, cover the back-sheet 3 of the lower face side of core assembly 4.Recess 51 forms with side liner 2.Core assembly 4 comprises the cotton paper 44 of the liquid permeability of liquid-absorbent mixtures of material 43 and conduct parcel sheet material, and wherein liquid-absorbent mixtures of material 43 comprises wooden pulp fibers 41 of fine hair and superabsorbent polymer granule 42 at least.In addition, liquid-absorbent structure 5 comprises and is used for hot-melt adhesive layer HA1, HA2, HA3 and HA5 that these members are engaged with each other.Through using sharp cutting tool cutting also to amplify about 30 times of this cross section to obtain the cross section, can visually confirm the cross sectional shape of core assembly 4 shown in Fig. 4 and liquid-absorbent structure 5 through optics by the liquid-absorbent structure 5 of liquid nitrogen freezing.

When observing liquid-absorbent structure 5 under the flat state in Fig. 3, every 1cm of liquid-absorbent structure 5 ²Surface area on the quantity of quantity and superabsorbent polymer granule 42 of the wooden pulp fibers 41 of fine hair at any regional constant of liquid-absorbent structure 5.That is to say every 1cm of the smooth back-sheet 3 shown in Fig. 4 ²On quantity and the quantity constant of superabsorbent polymer granule 42 of the wooden pulp fibers 41 of fine hair.Opposite, in cross section as shown in Figure 4, core assembly 4 is recessed in recess 51, thus the wooden pulp fibers 41 of fine hair and superabsorbent polymer granule 42 each other more near, and flock together to be closely adhered to each other with.This itself itself meets true with superabsorbent polymer granule 42 to the wooden pulp fibers 41 of fine hair.By this way, superabsorbent polymer granule 42 is in the state that possibly form gel piece.Yet at non-recessed region 52, core assembly 4 is not recessed or recessed significantly unlike recess 51 that kind, so the wooden pulp fibers 41 of fine hair disperses with discrete each other mode with superabsorbent polymer granule 42 fully.In recess 51, mixture 43 utilizes hot-melt adhesive HA1 and engaging of cotton paper 44 to be configured to and is through the shape that user all keeps recess 51 on one's body no matter diaper 1 is whether actual.

Through having the liquid-absorbent structure 5 that can obtain to be in the state shown in Fig. 3 and 4 with liquid-absorbent structure 5 identical components and liquid-absorbent structure depression with uniform thickness size of the gauge that is equal to or greater than non-recessed region 52.The depression that has corresponding to recess 51 can be used for above-mentioned depression with protruding roller, thereby makes that these convexities can be in room temperature or heating lower compression liquid-absorbent structure.The high-precision two-dimensional laser displacement quantifier of the Keyence manufactured of stating after the use (2D Laser Displacement Gauge) is measured recess 51 and the gauge value of non-recessed region 52 in the liquid-absorbent structure 5 comprise core assembly 4, side liner 2, back-sheet 3 and outer sheet 6.In order to measure the gauge of recess 51, from 100cm ²Select 10 recesses 51 in the area, and measure the gauge value of each recess 51 through the bottom of using each recess 51 of laser beam irradiation, and from each measured value calculating mean value.In order to measure the gauge of non-recessed region, from 100cm ²Select 10 zones in the area, use each zone of laser beam irradiation to measure each gauge value, from each gauge value calculating mean value with big relatively gauge.

In the recess 51 of liquid-absorbent structure 5, because recessed effect, wooden pulp fibers 41 mats of fine hair and superabsorbent polymer granule 42 are close to each other.Therefore, even when discharge and absorb body fluids, also can limit the expansion of the wooden pulp fibers 41 of fine hair, equally also can limit because the increase of the superabsorbent polymer granule 42 that the formation gel piece causes.Therefore, can limit the increase of the thickness of liquid-absorbent structure 5 and periphery thereof in the recess 51.Although such remarkable unlike recess 51, the thickness of the liquid-absorbent structure 5 in the non-recessed region 52 increases also can obtain restriction, and this is because the motion of the both sides of non-recessed region 52 as shown in Figure 4 is limited by each recess 51.By this way, compare with the liquid-absorbent structure that is not formed with recess 51, the exemplary liquid-absorbent structure 5 that illustrates helps to prevent that liquid-absorbent structure 5 from unacceptably thickening at the crotch region 7 of diaper 1.That is to say that liquid-absorbent structure 5 can not exceedingly thicken and make the contact skin of itself and user or the space between constriction structure 5 and the user skin unacceptably.With this kind mode, diaper can not cause uncomfortable feeling to user through moisture.Another favourable result can prevent that liquid-absorbent structure 5 from exceedingly thickening and the undesired expansion of this liquid-absorbent structure 5 that thickens when between the shank of user, being extruded.

In order to realize this effect reliably, need to specify the soaking effect of superabsorbent polymer granule 42 equally.From this viewpoint, employed superabsorbent polymer granule 42 preferably shows 45ml/g or the littler water absorption under water absorption and the load that is less than or equal to 14g/g of not pressurizeing.

The demand wettability tester (Demand Wettability Tester) that uses Scientific Machine&Supply limited liability company system to make is measured the water absorption of not pressurizeing.This tester is designed to use 0.9% the NaCl aqueous solution nylon wire (N-No.250HD that NBC industry is made) as normal saline and 250 meshes.The particulate amount of the superabsorbent polymer that is used to measure is 1 gram.In the present invention, the water absorption of not pressurizeing is meant at the water absorption test that do not pressurize and begins the absorbtivity measured in back 5 minutes.

In order to measure down water absorption of load, use the cylinder of processing by plastic material, internal diameter is formed by 250 mesh nylon wires as 26mm and bottom.Quality is that the superabsorbent polymer granule of S is introduced in this cylinder, and with predetermined weight the piston that it applies load is inserted in the cylinder.Confirm the oeverall quality W1 of this assembly then.The assembly that comprises cylinder is placed on the test vessel that include the 25g normal saline, and is left standstill 60 minutes.When the assembly that from the test vessel, will comprise cylinder takes out, confirm the quality W2 of this assembly, and according to water absorption under the following formula calculated load.

Load is water absorption (g/g)=(W2-W1)/S down

Effect and effect for the absorbent structure 5 that improves diaper 1; Can perhaps can this non-woven fabrics be engaged in side liner 2 whole or part with substituting side liner 2 such as liquid permeability and sheet elements such as non-woven fabrics that on the length direction of diaper 1, have high dispersing liquid ability simultaneously.Be suitable for a non-woven fabrics that is exemplified as more than half composition fibers orientation on the length direction A of diaper 1 as the sheet element of this purposes.In the liquid-absorbent structure 5 in Fig. 4; If it is compressed together that superabsorbent polymer granule 42 is crossed tightly with the wooden pulp fibers of fine hair 41; Then cotton paper 44, side liner 2 and other members are heaved; If the fiber and the excessively restriction of the quilt of the space between the fiber that are used to keep water that perhaps limit in the wooden pulp fibers of fine hair, then the water absorption of liquid-absorbent structure 5 and water absorbing capacity may descend.The part that use such as the sheet elements such as non-woven fabrics with high dispersing liquid ability will be discharged to the liquid on the crotch region is dispersed with to be beneficial on length direction A and prevents leak of liquid and prevent to feel moist.

For the ease of diagram, the Fig. 5 that shows one embodiment of the present invention compares Fig. 3 and shows recess 51 with bigger ratio.With reference to figure 5, in a recess 51a of recess 51, lower surface has the flat shape that is approximately equilateral triangle, is connected to three bights (turning) 55a in the circle 56 in this equilateral triangle has respectively.The diameter E of circle 56 is for example in the scope of about 1.5-5mm.In this special embodiment; In the recess 51 of contiguous recess 51a; At recess 51a with between the recess 51b near recess 51a, bight 55b among three bight 55b of recess 51b faces with a bight 55a among three bight 55a of recess 51a mutually.Between bight 55a that faces with each other and 55b, define non-recessed region 52.Than the situation that bight 55a, 55b do not face with each other between these two

recess

51a and 51b, through the configuration of recess 51a shown in Fig. 5 and recess 51b, the size P of the non-recessed region 51 that between these two

recess

51a and 51b, extends is shorter.The situation that relative size P is bigger in short relatively non-recessed region 52, is restricted to less owing to body fluid absorbs the varied in thickness that causes.

In the diaper shown in Fig. 61, be formed on the distribution density of recess 51 on whole side liner 2 in the liquid-absorbent structure 5, promptly every 1cm ²The quantity of side liner 2 formed recesses 51 is different on length direction A.In Fig. 6, be distributed in the every 1cm on the side liner 2 ² Side liner 2 on the quantity of point 23 in the first area 61 that the mid portion of being observed the A along its length of crotch region 7 limits, be maximum, and in the second area 62 that limits successively towards front waist region 8 and the 3rd zone 63 and/or limiting successively towards rear waist region 9 the 4th the regional the 64 and the 5th regional 65 in little by little or staged reduce.Every 1cm ²The quantity of point represent the quantity of recess 51 and every 1cm ²Recess 51 quantity from the mid portion of crotch region 7 towards front waist region 8 and rear waist region 9 little by little or staged ground reduce.In diaper designed 1 by this way; The mid portion restriction that can observe at the A along its length of crotch region 7 is because the increase of thickness arbitrarily of the liquid-absorbent structure 5 that Liquid Absorption causes; And thereby liquid can be prevented that by absorption promptly liquid from resting on the mid portion of crotch region in second to the 5th zone; Wherein in second to the 5th zone, the existence of recess 51 can be ignored (or not remarkable) to the influence of Liquid Absorption amount.Although do not illustrate,, diaper 1 can only be formed with first area 61, second area 62 and the 3rd zone 63 and not comprise the 64 and the 5th zone 65, the 4th zone.Equally, diaper 1 can only be formed with the 61, the 4th regional the 64 and the 5th zone 65, first area and not comprise second area 62 and the 3rd zone 63.In addition; Can expect a plurality of selections, for example, in one embodiment; Core assembly 4 only exists in crotch region 7 and front waist region 8 with the liquid-absorbent structure 5 that comprises this core assembly 4, and correspondingly only is formed with first area 61, second area 62 and the 3rd zone 63; In one embodiment, core assembly 4 only exists in crotch region 7 and rear waist region 9 with the liquid-absorbent structure 5 that comprises this core assembly 4, and correspondingly only is formed with first area 61, the 64 and the 5th zone 65, the 4th zone.In addition, can expect following replacement embodiment: core assembly 4 only exists in crotch region 7 with the liquid-absorbent structure 5 that comprises this core assembly 4 and correspondingly only is formed with first area 61.

In a preferred embodiment, as shown in Figure 7, all parts that recess 51 is formed at core assembly 4 and side liner 2 all are not included in any recess 51.In core assembly 4, mixture 43 is compressed in the direction that the liner 2 from the side extends towards back-sheet 3 with cotton paper 44b, promptly on the thickness direction of core assembly 4, be compressed, so core assembly 4 is formed with recess 51.Side liner 2 flatly extends and is engaged in through hot-melt adhesive HA2 the non-recessed region 52 of core assembly 4.

If the non-woven fabrics of the softish larger volume of quality is formed with recess 51 as side liner 2 and this side liner 2, then the intrinsic quality of side liner 2 may worsen.Can overcome this problem through liquid-absorbent structure 5 according to the embodiment shown in Fig. 7.About cotton paper 44b; Use almost inductile cotton paper 44b in this embodiment; Thereby, can in the process that forms recess 51, more closely contact with mixture 43 at every pair of adjacent recess 51, the non-recessed region 52 that limits between 51 than the situation of using the cotton paper that to extend relatively.As favourable result, non-recessed region 52 can not increase owing to Liquid Absorption make the thickness of itself, even and when guaranteeing Liquid Absorption takes place non-recessed region 52 also can resist expansion well.As remaining advantageous effects of this embodiment, side liner 2 is partly spaced apart with cotton paper 44b, and prevents easily to see the urine color on the core assembly 4 through side liner 2.

Core assembly 4 employed terms " thickness of the thickness of recess 51 and non-recessed region 52 " in the embodiment shown in Figure 7 are meant the one-tenth-value thickness 1/10 that the core assembly 4 that does not comprise side liner 2, back-sheet 3 and outer sheet 6 is measured.Can obtain measured core assembly 4 through in the process of making liquid-absorbent structure 5, before joining side liner 2 and back-sheet 3 to core assembly 4, picking up core assembly 4.

With reference to Fig. 8, Fig. 8 be exemplarily illustrate the distribution patterns of recess 51 on core assembly 4 to observe because the figure of the varied in thickness of the core assembly 4 that causes of absorbing water.As shown in Figure 7, have 17g/m through use ²The cotton paper of basic weight wraps up uniform mixture 43 (see figure 7)s and obtains core assembly 4 to have rectangular cross sectional shape, and wherein mixture 43 comprises: (i) have 220g/m ²The wooden pulp fibers of the fine hair of basic weight; (ii) has 220g/m ²In the multiple superabsorbent polymer granule of basic weight any one, said rectangular cross sectional shape has the length dimension of 410mm and the width dimensions of 145mm.The figure shows cotton paper 44b that is used for core assembly 4 and the recess 51 that is formed on cotton paper 44b.Recess 51 among Fig. 8 all has the flat shape that each length of side Q is the roughly equilateral triangle of 3mm.Recess 51 is positioned at orthohexagonal each bight (turning) that dotted line representes to be located, and wherein between every pair of adjacent recess 51, relevant turning faces with each other with distance P.Table 2 shows core assembly 4 at the thickness at each recess 51 places and core assembly 4 thickness at non-recessed region 52 places.The varied in thickness of core assembly 4 is observed equally when core assembly 4 absorbs replacement artificial moisture urine, and the result that should observe is shown in the table 2.

For this observation, used three types the superabsorbent polymer granule that has different water absorption characters respectively, i.e. SAP-A, SAP-B and SAP-C.These superabsorbent polymer granules are commercial.

According to water absorption rate and the water conservation rate in JIS (Japanese Industrial Standards) K 7223 meters 1.Particularly, the superabsorbent polymer granule of 1.0 grams is placed in the mesh bag, and is immersed in the normal saline 1 hour.From normal saline, pull out mesh bag then and hang 15 minutes to drain normal saline.In this state, measure the amount of the normal saline that is absorbed by the superabsorbent polymer granule, to obtain water absorption rate.After draining normal saline, through centrifuge to mesh bag dehydration and the quality of measuring mesh bag to obtain the water conservation rate.

With reference to table 2,200 gram carbamide, 80 gram sodium chloride, 80 gram magnesium sulfate, 80g calcium chloride and about 1 gram pigment (blue No. 1) are dissolved in 10 liters of aqueous solutions in the ion exchange water as artificial urine.The color of artificial urine is blue.

120 milliliters artificial urine with divide three times, at every turn inject 40 milliliters and between injecting continuously at interval 5 minutes mode be injected into the A along its length of core assembly 4 and the mid portion that width B observes, and absorbed by core assembly 4.Use burette to inject artificial urine.The core assembly 4 that is marked with artificial urine is placed on the polyethylene film that places platform.

The distance expression of the center to center of listing in the table 2 is used to form the distance of the depression of recess with the center to center of the pin on the roller (not shown) side face, and the distance that can confirm this center to center is roughly corresponding to the distance of the center to center that is formed on the recess on the core assembly.

The recess of in " thickness of core assembly " hurdle, listing and the one-tenth-value thickness 1/10 of non-recessed region are before core assembly is injected into artificial urine, and the high-precision two-dimensional laser displacement quantifier LJ-G030 through using the Keyence manufactured carries out the value that contact measurement not obtains to being placed on core assembly on the platform.

Inject before the artificial urine with the one-tenth-value thickness 1/10 that injects after the artificial urine and be listed in " varied in thickness of non-recessed region " hurdle, and said one-tenth-value thickness 1/10 is to carry out the value that contact measurement obtains through dial-type (dial) thickness gauge that use has a 50mm diameter.Particularly, the probe of the thick amount meter of dial-type contacts with the core assembly of placing in the plane 4 from the top, and at 6.5g/cm ²Measurement load down thickness gauge is carried out reading.One-tenth-value thickness 1/10 after injecting artificial urine measured in back 5 minutes each the injection.

After 80 milliliters artificial urines have been injected into core assembly 45 minutes, the full-size of the artificial urine on the length direction A that is dispersed in core assembly 4 is carried out 5 times (n=5) measure, and take the mean to obtain " dispersion length " measuring numerical value.

Through in the core assembly 4 of experimental evaluation, inject thickness the increment ((T-T that the little core assembly 4 to acceptable degree of varied in thickness after the artificial urine is limited to non-recessed region for the third time ₀)/T ₀) be less than or equal to 2.2 situation.The superabsorbent polymer granule that can guarantee this increment is limited to SAP-A.In order to make SAP-A guarantee this functional effect; The water absorption of not pressurizeing that assessed value in the table 1 shows the SAP-A that begins to measure in back 5 minutes at the water absorption test that do not pressurize is preferably smaller or equal to 45ml/g; More preferably smaller or equal to 40ml/g; And water absorption is preferably smaller or equal to 14g/g under the load of SAP-A, more preferably smaller or equal to 12g/g.The thickness of the recess of measuring through contact method not is preferably smaller or equal to 80% of the thickness of non-recessed region, and the distance L of the center to center of recess is preferably in the scope of about 2-14mm.

Table 1

Table 2

As an embodiment of the invention, can recess 51 be formed at the surface in the face of back-sheet 3 of core assembly 4, its center dant 51 can get in the back-sheet 3, also can not get in the back-sheet 3.

As another embodiment of the invention, can realize with the form of trousers type diaper with the exemplary disposable diaper that illustrates of the form of open-type diaper 1.

Above-mentioned aspect can dispose at least as follows:

(i) a kind of disposable diaper, it has length direction and width, and said disposable diaper comprises: front waist region, rear waist region and the crotch region between said front waist region and said rear waist region; With

Cover the side liner of liquid permeability of the upper surface of said core assembly at least in part,

Wherein:

A plurality of recesses recessed on the thickness direction of said core assembly are formed at said core assembly at least, and in said recess, said mixture and said parcel sheet material are bonded together through hot-melt adhesive;

The aspect that above-mentioned (i) describes can provide one or more following advantageous effects:

(a) comprise that wooden pulp fibers of fine hair and the particulate core assembly of superabsorbent polymer are formed with a plurality of recesses.Through this processing, can cooperate with the volume and the thickness increase of absorb body fluids time limit coremaking assembly at wooden pulp fibers of fine hair and superabsorbent polymer granule.The diaper that comprises this improved liquid-absorbent structure can overcome or alleviate various problems; For example the liquid-absorbent structure division is expanded to the problem of undesired size and dimension, and/or the liquid-absorbent structure excessively closely contacts the problem that also causes user to feel under the weather through moisture with the skin of user.

The aspect that above-mentioned (i) describes can comprise following at least embodiment:

(ii) said recess is to form with mode that said side liner is faced mutually.

(iii) said disposable diaper also comprises the back-sheet of the non-liquid permeability of the lower surface that covers said core assembly at least in part, and wherein said recess is to form with mode that said back-sheet is faced mutually.

(iv) said recess is formed at said core assembly and said side liner.

(v) said side liner is not included in the said recess.

(vi) said back-sheet is not included in the said recess.

(vii) said liquid-absorbent structure is crossed said crotch region and is extended at least one side in said front waist region and the said rear waist region, and said recess only is formed at said crotch region.

(viii) said liquid-absorbent structure is crossed said crotch region and is extended at least one side in said front waist region and the said rear waist region, and said recess also is formed at least one side's in said front waist region of extending to of said liquid-absorbent structure and the said rear waist region part.

(ix) every 1cm on the surface of said core assembly ²The quantity of the middle said recess that forms reduces towards at least one side said front waist region and the said rear waist region from the mid portion of said crotch region.

(x) every 1cm on the surface of said core assembly ²The quantity of the middle said recess that forms is constant.

(xi) said fine hair pulp fibers in the said core assembly and said superabsorbent polymer granule have at about 100-350g/m separately ²Basic weight in the scope, and said fine hair pulp fibers and said superabsorbent polymer granule have at about 300-600g/m altogether ²Basic weight in the scope.

(xii) disposable diaper according to claim 1 is characterized in that, the particulate density of said superabsorbent polymer that is present in said recess is bigger than the particulate density of said superabsorbent polymer that is present in said non-recessed region.

(xiii) disposable diaper according to claim 1 is characterized in that, said superabsorbent polymer granule has the water absorption of not pressurizeing smaller or equal to 40ml/g.

(xiv) disposable diaper according to claim 12 is characterized in that, said superabsorbent polymer granule has less than water absorption under the load of 12g/g.

(xv) disposable diaper according to claim 1 is characterized in that, the circle that is connected in the said recess wherein has the diameter in about 1.5-5mm scope.

According to the above-mentioned embodiment that (ii) arrives (x), guaranteed the more than one advantageous effects of in (a), mentioning better.

The application requires the rights and interests of japanese publication No.2011-048343, and all disclosures of this japanese publication are herein incorporated by reference.

Claims

1. disposable diaper, it has length direction and width, and said disposable diaper comprises:

Wherein:

2. disposable diaper according to claim 1 is characterized in that, said recess is to form with mode that said side liner is faced mutually.

3. disposable diaper according to claim 1; It is characterized in that; Said disposable diaper also comprises the back-sheet of the non-liquid permeability of the lower surface that covers said core assembly at least in part, and wherein said recess is to form with mode that said back-sheet is faced mutually.

4. disposable diaper according to claim 1 is characterized in that, said recess is formed at said core assembly and said side liner.

5. disposable diaper according to claim 2 is characterized in that, said side liner is not included in the said recess.

6. disposable diaper according to claim 3 is characterized in that said back-sheet is not included in the said recess.

7. disposable diaper according to claim 1 is characterized in that, said liquid-absorbent structure is crossed said crotch region and extended at least one side in said front waist region and the said rear waist region, and said recess only is formed at said crotch region.

8. disposable diaper according to claim 1; It is characterized in that; Said liquid-absorbent structure is crossed said crotch region and is extended at least one side in said front waist region and the said rear waist region, and said recess also is formed at least one side's in said front waist region of extending to of said liquid-absorbent structure and the said rear waist region part.

9. disposable diaper according to claim 1 is characterized in that, every 1cm on the surface of said core assembly ²The quantity of the middle said recess that forms reduces towards at least one side said front waist region and the said rear waist region from the mid portion of said crotch region.

10. disposable diaper according to claim 1 is characterized in that, every 1cm on the surface of said core assembly ²The quantity of the middle said recess that forms is constant.

11. disposable diaper according to claim 1 is characterized in that, said fine hair pulp fibers and said superabsorbent polymer granule in the said core assembly have at about 100-350g/m separately ²Basic weight in the scope, and said fine hair pulp fibers and said superabsorbent polymer granule have at about 300-600g/m altogether ²Basic weight in the scope.

12. disposable diaper according to claim 1 is characterized in that, the particulate density of said superabsorbent polymer that is present in said recess is bigger than the particulate density of said superabsorbent polymer that is present in said non-recessed region.

13. disposable diaper according to claim 1 is characterized in that, said superabsorbent polymer granule has the water absorption of not pressurizeing smaller or equal to 40ml/g.

14. disposable diaper according to claim 12 is characterized in that, said superabsorbent polymer granule has less than water absorption under the load of 12g/g.

15. disposable diaper according to claim 1 is characterized in that, the circle that is connected in the said recess wherein has the diameter in about 1.5-5mm scope.