CA2223082A1

CA2223082A1 - Sanitary napkin

Info

Publication number: CA2223082A1
Application number: CA002223082A
Authority: CA
Inventors: Maki Hasegawa
Original assignee: Individual
Current assignee: Procter and Gamble Co
Priority date: 1995-06-02
Filing date: 1996-05-09
Publication date: 1996-12-05
Also published as: WO1996038110A1; EP0830120A4; NO975532L; BR9608536A; KR100621371B1; HUP9901429A3; HUP9901429A2; EG20715A; JPH08322879A; MX9709260A; TW338314U; JP2974934B2; CN1120698C; NO975532D0; KR19990022241A; CO4700393A1; EP0830120A1; CZ383597A3; TR199701485T1; AU712928B2

Abstract

This invention is a sanitary napkin (2) comprising a fluid permeable top sheet (4), a fluid impermeable back sheet (6), and an absorbent core (8) disposed between said both sheets, the back sheet (6) having a shape complementary to a contour of the sanitary napkin (2), being substantially elongate, and being wider (16) at a rearward portion thereof than at a forward portion (20) thereof, the absorbent core (8) being narrower than the forward portion of the back sheet (6), a first adhesive layer (14) being disposed on a side of the back sheet (6) in a region where the absorbent core (8) is present, second adhesive layers (28) being disposed on the same side of the back sheet (6) in a rearward portion of the back sheet (6), which is on both sides of the absorbent core (8) and in which the absorbent core (8) is absent, and the first adhesive layer (14) securing the sanitary napkin to the inside of underwear, and the second adhesive layers (28) securing the rearward portion of the back sheet spread inside the underwear.

Description

SANITARY NAPKIN
FIELD OF T~ INVENTION
s The present invention relates to a sanitary napkin which is worn on a female body to absorb body fluid, more spe~ific~lly to a sanitary napkin having a fol~dportion made wider than a r~ w~d portion Sanitary napkins have been used as con c~;or~l means which are worn on female bodies for abs~ ~ body fluid Typically the convc~.tional sanita~y napkinshave CQ~ widths from the front ofthe body of a wearer to the back thereo~ Such napkins, because of their shape, because of their co~.s~ widths, have high pro~ Q~ e~ y and are ad~ o~Js in material saving It cannot be said, ku. _~er that such napkins are not s~ - ;e~.~ly pr.,~ e for ~uid le9L'SI,ge at the rear pûl liGlLs That is, for a long time use of such napkins in sleeping at night, pr~ tion offluid leakage at the backward portion ofthe Iying body is a s;~ l problem To 20 solve this problem, sanitary napkins having portions thereof corre-s~~ g to the backward portion of the body of a wearer of the sanitary napkins made wider thanthe f~ d po- Iions thereof are used Such s~lit&~l napkins have probl-mc that the s~..l~ napkins cannot be 25 secured stable to undh. ~r because of the wider r~- ~d p~-lions, the side ~s.lions of the re&~ ~d pû.lions are turned up in use and jeopa~di~e the long-time leakage p.~ ion I~n packaging the individual sal~y napkins, the wider portions makc the individual packages large, and in packaging the individual napkins with the wider pû.Lons folded, it is nrces~- y that the wider po.lions are kept folded until the 30 paclcaga are completed, which makes their pro~u~ion ~liffi~
An object of the present invention is to provide a s~lit~ napkin which has a witer rca~ward portion to thereby prevent fluid leqL-age Another object ofthe present invention is to provide a sarul~ napkin a wider ~d portion of which is stable to effect fluid leakage pl~ ltion Further another object of the present invention is to provide a s~.it~r napkin a wider rearward portion of which can be folded stable SIJMMARY OF T~ INVENTION

CA 02223082 l997-l2-02 W O 96/38110 PCTrUS96/06572 The sanitary napin according to the present invention CGlllpl;~S a fluid perrneable topsl,e~l dis~,osed on a side of the sanitary napkin, which is to be opposed to the body of a wearer, a fluid ;",pe. ~able bacL~l-eet dispose~ on a side of the sanitary napkin, which is to be opposed to unde. .. ~r of the wearer, and an absorbent 5 core .l;~yosed between said both sheets, the barL ~hC~t having a shape which agrees with a cGlllour of the sanitary napkin and which is Sll~Ga~ lly elongate from the front to the back of the body of the wearer, and being wider at a rearward portion thereof cG"~spond~-~ to a rearward part of the body of the wearer than at a fc., ~ d portion thereof cG"~syonding to a forward part of the body of the wearer, the 10 abso,b.,.,l core being na.,~. c~ than the forward portion of the bzcLcheet a first adhesive layer being d;~osed on a side of the backsheet to be opposed to the unde.-.~,ar in a region where the absG,l,cllt core is present, second adhesive layers being ~1 ~yO~d on the side of the backsheet to be opposed to the unde.-.car in pGll;ons of the rearward portion of the b~L~l~eet which is on both sides of the 5 abs~.l,cnl core and in which the absG.l..,nt core is absent, and the first adhesiw laya securing the sanitary napkin to the inside of the underwear, and the second adhesive layers securing the rearward portion of the bacL-cheet spread wider inside the ul.d~...~.

BRIEF DESCRIPTION OF THE DRAWINGS
FIG.l is a top view of the sanitay napL,in acco,.ling to one e.,lbodimc~t of thepresent invention.
2s FIG. 2 is a sectional view of the sanitary napkin of FIG. 1 along the line II-II.
FIG. 3 is a top view of the sanitary napkin of FIG l in its folded state.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A p~fe..~d ~ho~ t of the present invcnlion will be e~pl~: ~ed with rcfc~.~cc to the d~a- ~ngs. FIGs. 1 to 3 show the sar.i~r napkin a~s~ding to a first 35 ~ ~bG~ n of the present invention. A napkin generally ~p.c~nlcd by l-,fe.~ncenumber 1 cGlllyl;ses a fluid pc-ll,eable topsl,e. t 4, a fluid illly~,. e?ble backsheet 6 and an absoll,c"t core 8. It is ;lllpoll~lt that fluid dischar~cd by the body of a wearer and does not excessive unpleasant touch to the wearer when the topshe~t 4 directly contacts the skin of the wearer. The topshcet 4 is suitably made of, woven or unwoven fabric of natural fibers or synthetic fibers, lh~."OF!15'1;C ~"lh~lic resin fil n having a number of pores formed in, porous s,vnthetic resin foam, net s,vnthetic foarn, net IL~.l.loplas~ic synthetic resin film, lhe.lllopla~lic ~lltL~lic resin scrim or others. It is illlpoll~t that the backsheet 6 has the filnctio~ that fluid absG,bed by the ~bs3l1,ent core 8 flows out of the napkin to smear the wearer herself and/or her clothes, and is W O 96/38110 PCTrUS96/06572 suit ab1y forrned of flexible fluid il~lp. .lllcable thermoplastic synthetic resin film, such as~polyolefin film. Fspeciqlly suitable film of which the bs~L-chfet 6 include low-density polyethylene film of 0.01 - 0.05 mm thicLnpcc> espec;qlly about 0.025 mrn tl~:c- ~-f 55 (marketed as "MODEL XP 39385" by Ethyl Corp., Visqueen Division, and 5 a_ "SOFLEXX 1401" by Clopay Corp., C;.~.,;nn~l;, Ohio, U.S.A.). It is illl~oll~l that the abso,l,c,lt core 8 d:cl)os~ inle....f~-1iqte between the topsheet 4 and the ba~l~cheet 6 absorbs and holds fiuid which has been disch~,cd by the wearer and pc.lllcalfd the topsllf~,t 4. The absoll,c.l~ core 8 is suitably forrned of, e.g., finely pulverized pulp so called air felt, creped cell~lose-filled cotton, melt blow polyrner, 10 chemically ri~ fie~ mo~lififd or cross linked cellul~se fiber, absGll,cnt synthetic resin foam, tissue paper layer, absG.l,ulg gelling material (which absorbs fluid and gels), or suitable co~k;-~;onC of these materials.
In the shown em~odimPnt~ the top~l-~t 4 is s~Jbs~ ly the same as the 5 bac.~sheet 6 in shape and ~ f r~- onc, The topshc-,l 4 and the backsheet 6 are hot melted uninle~ pted on each other along the entire bolln~lqry edges. The hot melted region 10 of the top and b ~ L ~h~s 4, 6 is ;~ dic~te~ by cross slant lines and by slant lines in FIG. 2. If ~ cce~ y, the topsl-f~l 4 and the to p sheet 6 may be bonded to each other by, e.g., an adhesive. As dcs.,.ibed above, the tOpClc~l 4 and the 20 backsheet 6 have the same shape, and the shape is that of the napkin 2. The absoll,en~ core 8 is laid in the direction of a length of the napkin (up to down in FIG.
1) and has l~bst~ ~1;slly the same vidth (lateral length in FIG. 1) along the entire length.A layer 3 of an adhesive for sc~-ing the napkin to the undc-~.~ of the wearer is ~ pos~ at a poi t;o-~ on the outside surface of the backsheet 6, which2s ~ik~s~ y CGIl-3pQl~Q tO the absorbent core 8. As the adhesive, "Century Adhesive A-305-IV" by Century Adhesive Corp., Co~ nbu~, Ohio, U.S.A. is suitablyused. In the case that the layer 3 of an adhesive is provided on the outside surface of the backsheet 6, preferably the adhesive is covered with a sheet of silicone coated papa for pl~,nth~g the adhesive from cG~ .. n~ n before use.
The top hc~t 4 and the bac~cheet 6 are l~r~ected at a little f~ rd (upward a~ vicwed in FIG. 1) beyond the side edge 8a of the absorbent core 8 lataally outward at posidons on the lCII~ .;3C edges, which are a little offset f~ ud (upward as viewed in FIG. 1). The plujected portions pro~idc wings of the napkin 2.
35 The wings 12 are turned onto the crotch region of underwear when the napkin 2 is used. If nec~ss-~y~ layers 14 of an adhesive for securing the wings to underwear may be disposed on the side of the t ac~cheet 6 to be opposed to the underwear.
The ~opshe~l 4 and the bac~cheet 6 are projected further at a rtal.~v~.i portion of the napkin 2 laterally outward beyond the side edge 8a of the absoll,~,n core 8. This pr~j~ion provides a wider portion 16 which pre~ s leakage at a lo~t~ inslly re&~.~d portion (downward as viewed in FIG. 1). Regions of the napkin 2 c0l,~3porc~ g to the hips of a wearer are the wider portion 16, whereby the leakage e~ect in these regions can be improved.

W O96/38110 PCTrUS96/06572 The wings 12 and the wider portions 16, which are thus formed beyond both side edge 8a of the abso,l,~.,l core 8 define a neck portion 18 there between. When the napkin 2 is used, ko.._~er, the wings 12 of the napkin 2 are turnet back on 5 underwear of a wearer, an d a~c~:di~ the napkin in use has s~ y the same width longitu~inslly from the forward end 20 thereof to a base 22 of the neck portion 18 and gradually increases the width longitu-lin-s-lly rearward from the base 22 of the neck portion 18.
As desc,il,ed above, the topshe~l 4 and the baclrcheet 6 are hot melted on each other at the hot melted region 10. This melting secures the top~.heel 4 and the backsheet 6 melted on each other at parts thereof outside the forward end edge, the ,~&~d end edBe and the side etBe ofthe su~so.l.c.lt core 8. The topshccl 4 and the backshcet 6 are hot melted on each other further at bases 24 of the wings 12 ands bases 26 ofthc witer portion 16 (the hot melted regions are i..~ cd by slant lines in FIGs. 1 and 2). The hot melting in the hot melted regions ,~ lly secures theparts of the top he~,l 4 and the backsheet 6 which lie outside the boundary edBe of the abso,l.~ core 8 therealong. Thus the absG,l.cnl core 8 is set in pos t;on inside the napkin 2.
As dc.._,il,ed above, the absorbent core 8 has s--bs~- n; lly the sarne width inthe IQr~tU~;n~1 duc~,tion of the napkin 2. This shape of the absG,l,enl core 8 de~ ascs pGI lions thereof to be cut off in pro~ucing the napkin 2, which contributes to lower prod~ ion costs. The absorbent core 8 is absent in the wings 12 and the25 po.lions of the wider portion 16 pr~ected beyond both side edges of the abso l,c~lt cores 8. The absence of the absG-l,c.lt core 8 in the wings 12 adv~ntageo~sly makes the wings 12 flexible enough to be folded. In the p~e;ted po,lions of the wider portion 16, li~ ., the ~'o~nce of the absorbent core 8 lowers rigidity of the pr~ected po,lion~ of the wider portion 16. To compensate the disadvantage of theinSI~- t-'1 rigidity, layers 28 of an adhesive a reprovided on pGI lions of the side of the b~he~ 6 to be opposcd to underweu of a weuer, which (portions) ue in the vnd~r portion 16. When the napkin 2 is used, the p.oje~ted po.~ons of the wider portion 16 are spread inside the under..~r of a weuer and adhaed to the inside sur~ce of the undc. .. ~r by thc adhesive layers 28. The adhesive layers 28 hinder the 35 pr~ected po.lion~ of thc wider portion 16 from peeling off in contact with the body of the weuer.
FIG. 3 shows the sunituy napkin according to the e."bod;",en~ of FIG. 1 with the wing 12 und the proje~led portions ofthe wider portion 16 folded. As shown in FIG. 3, the wing 12 und the proje~led po,lions ofthe wider portion 16 ue folded on the topshc~,l 4 . The adhesive layers 14 on the wings 12 ue covered with a release sheet 30 with a release agent, such as silicone or othas applied to the surface, und the left und the right wings ue i,l~e~onl-ec~ed with each otha by the release sheet 30. The adhesive layers 28 on the projected po,lions ofthe wider portion 16 ue also W O 96/38110 PCTrUS96/06572 covered with a release sheet 32 with a release agent, such as silicone or others, applied to the surface, and the left and the right projected portions of the wider portion 16 are interconnPcled with each other by the release sheet.
s Thus, the portions which are projecled laterally outward beyond the ab~,l.~.d core 8, i.e., the wings 12 and the projected portions of the wider portion 16, are folded onto the top~.he~ 4 towards the transverse center of the absG.l,c~lt core 8 along the side edges 8a, whereby the napkin 2 can have a small width. An individual paç~age of t he napkin 12 can be accordi.,gly small. The wings 12, and the 0 pr~ected portions of the wider portion 16 can be interco~ ed by their l~ye~,lire release sheets, whereby it is not nP~cecc-~y to press the wings 12 and the proje ted po,lions ofthe wider portions 16 folded, and the productiorl line can be simplc.
In the above-desc,ied e.l,bo~ the adhesive layers 3 for s~ing the napkin body 2 to unde.-.~r, and the adhesive layers 16 for ~ ing the proje~te~d po.l;ons of the wider portion 16 from peeling off the und~...car are s~p&ately provided, but in place, the adhesive layers 3 and the adhesive layers 28 may be con~ 1e~ In any case, it is n~c~cc--y that adhesive layers are provided on the backside of the backsheet in the prejected po,lions of the wider portion 16, where 20 the abso,l,~ core 8 is absent. Various design ch~e~5 are possible with the scope of the present invention.
In the sanitary napkin acco~ing to the present in~ tion, the p,~ected portions of the wida portion of the sanitary napkin, which are pos ;;oncd at rw ~ud 2s po,lions of the napkin are to be secured to the inside of l.nde ~.ear by means of the adhesive layers, ~.h~ the proj~cted po,lions of the wider portion are hindered from peeling off the u,ld~ ~, and stably long contribute to the leakage p,~ ~e.l~;on.
Even in a case that b~s~e of no absorbent core in the pr~e ted portions of the wider portion positioned at t he feal~ ~d portion of the s~..l~ napl~n, the 30 p~xted poll;ons ofthe wider portion have no s ~n~r;~ ~ rigidity, there is no risk that the p,oj~cted po.lions ofthe wider portion may peel off.

Claims

WHAT IS CLAIMED IS

A sanitary napkin comprising a fluid permeable topsheet disposed on a side of the sanitary napkin, which is to be opposed to the body of a wearer, a fluid impermeable backsheet disposed on a side of the sanitary napkin, which is to be opposed to underwear of the wearer, and an absorbent core disposed between said both sheets, the backsheet having a shape which agrees with a contour of the sanitary napkin and which is substantially elongate from the front to the back of the body of the wearer, and being wider at a rearward portion thereof corresponding to a rearward part of the body of the wearer than at a forward portion thereof corresponding to a forward part of the body of the wearer, the absorbent core being narrower than the forward portion of the backsheet a first adhesive layer being disposed on a side of the backsheet to be opposed to the underwear in a region where the absorbent core is present, second adhesive layers being disposed on the side of the backsheet to be opposed to the underwear in portions of the rearward portion of the backsheet which is on both sides of the absorbent core and in which the absorbent core is absent, and the first adhesive layer securing the sanitary napkin to the inside of the underwear, and the second adhesive layers securing the projected portions of therearward portion of the backsheet spread wider inside the underwear.
2. A sanitary napkin according to claim 1, wherein the absorbent core has substantially the same width from the front to the back of the body of the wearer.
3. A sanitary napkin according to claim 2, wherein the portions of wider rearward portion of the backsheet are folded toward a longitudinal center line of the sanitary napkin along the side edges of the absorbent core
4. A sanitary napkin according to claim 3, wherein the portions of wider rearward portion of the backsheet are folded onto the topsheet and side release sheets are applied to the adhesive layers.
5. A sanitary napkin according to claim 4, wherein the forward portions of the backsheet corresponding to the forward part of the body of the wearer are extended laterally outward beyond both sides of the absorbent core in wings which are to be folded onto a crotch region of the underwear.
6. A sanitary napkin according to claim 5, wherein the wings are provided adhesive layers and are folded onto the topsheet side toward a longitudinal center line of the sanitary napkin along the side edges of the absorbent core, and side release sheets are applied to the adhesive layers.