CN1085771A

CN1085771A - Sanitary towel with central collecting region

Info

Publication number: CN1085771A
Application number: CN93116829A
Authority: CN
Inventors: P·科尔斯; S·克兰尼克; P·吉安弗兰科
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 1992-07-27
Filing date: 1993-07-27
Publication date: 1994-04-27
Also published as: WO1994002092A1; CA2140036C; EG20052A; AU4655993A; CA2140036A1; MX9304533A; TR28137A; KR100270184B1; KR950702402A; JPH07509383A; AU4358997A

Abstract

In sanitary towel, have one to have the low relatively central collecting region that absorbs gel rubber material density.Central authorities' collecting region can increase liquid diffusion in the vertical, and this has reduced the danger of liquid along the peripheral spill and leakage of sanitary towel.

Description

Sanitary towel with central collecting region

The present invention relates to a kind of sanitary towel, said sanitary towel comprises that the egative film of top flat, one deck liquid impermeable of one deck liquid permeable and one deck are placed on the absorbent cores between top flat and the egative film, this absorbent cores comprises two vertical limits, central collecting region, in collecting region and vertical two border areas between the limit, this absorbent cores comprises that also one deck absorbs gel rubber material, and the density of the absorption gel rubber material in the collecting region of absorbent cores is lower than the density that absorbs gel rubber material in the border area.

This absorbent item is from US-A-4, can recognize in 988,345.

Introduced a kind of absorbent item in this piece patent, absorbent cores comprises having the more low-density liquid handling layer that is in the bottom and contain the fluid storage layer that is in top that absorbs gel rubber material in said absorbent item.The basis weight of the fluid storage layer of top 0.01 to 0.1g/cm ²Between, and can hold the absorption gel rubber material that reaches 60% weight.On fluid storage layer, have collection hole be used for liquid infiltration to below liquid handling layer, liquid can flow along the vertical and horizontal of absorbent item in this one deck.Liquid handling layer has the voidage above 80%, and its basis weight can be made of synthesising foam material or synthetic fibers at 15 to 75 gram/square yards.The liquid that sees through the collection hole on the fluid storage layer is transported to the fluid storage layer segment away from collection hole in liquid handling layer.Because the difference of capillarity power between fluid storage layer and the liquid handling layer, liquid is extracted out from the latter, so thereby the latter is emptied can transmit the body fluid of and then gushing out.

Because the relative broad of liquid handling layer, liquid to the horizontal proliferation of absorbent item side comparatively speaking than being easier to.The purpose of known liquid handling layer is to improve to leave a large amount of distribution of liquid of collection hole and improve infiltration rate under the situation of the gel blockage that does not have absorbing material.Particularly in narrow absorbent item, excessive liquid horizontal proliferation meeting causes undesirable side to pollute.

At U.S. Pat-A-5, introduced a kind of sanitary towel in 009,653 with absorbent cores, its absorbent cores comprises one deck hydrogel material between the piece of cloth of two-layer air lay.This absorbent cores is covered by the fabric that is used to improve the wet-laying that is discharged to the body fluid absorption on the absorbent cores, thus the more efficient use hydrogel material.Though improved liquid vertically flowing in sanitary towel, in the horizontal mobile of liquid also can take place, thereby still might pollute side.

An object of the present invention is to provide a kind of relatively little thickness that has, but but have better fluid distribution performance and absorbent item with relative simple structure.

Another object of the present invention provides a kind of the have lower side pollution level and the absorbent item of higher effective absorbance.

Another purpose of the present invention provides a kind of the have higher gathering speed and the absorbent item of lower cost.

Absorbent item of the present invention is characterized in that comprising the absorption gel rubber material between last fibrous layer and following fibrous layer, the amount that absorbs gel rubber material in collecting region on the fibrous layer of per unit area is less than the amount of the absorption gel rubber material of per unit area in the border area, the density that absorbs gel rubber material in the width of collecting region and the border area is suitable for liquid in absorbent cores, mainly is the conveying on vertically.

By absorbing the amount of gel rubber material in the middle section that reduces sanitary towel's absorbent cores, obtained having the big relatively liquid collecting and the collecting region of conveying capacity than limit portion zone, said edge portion contains in the zone gel rubber material of more amount thereby has higher relatively fluid preservation ability.Surprisingly have been found that the density of the absorption gel rubber material that reduces selectively in the central collecting region, can make sanitary towel have higher effective absorbance (absorbance before the pollution of limit portion occurring).This is for having relatively little thickness, and for example thickness is even more important less than 3 millimeters sanitary towel.This sanitary towel capacity in vertical direction is lower, so need utilize the sorbent surface of sanitary towel best.In order to make thin sanitary towel that enough absorbances be arranged, the density that absorbs gel rubber material in absorbent cores will be higher than the density that absorbs the absorption gel rubber material of gel rubber material and core part fiber mixing portion in the absorbent cores.The density that absorbs gel rubber material is gone up in the big zone of thin sanitary towel because " gel blockage " and increases of can not achieving one's goal, and therefore the absorbance of this sanitary towel is that the density of the absorption gel rubber material of maximum possible when not having gel blockage to occur determines.

Have been found that if the density of absorption gel rubber material is littler than maximum in the collecting region according to the present invention, can obtain the higher effective absorbance.

Because absorbing the amount of gel rubber material in the sanitary towel of the present invention is lower than the sort of gel rubber material that wherein absorbs and evenly is applied to and keeps absorbing on the fibrolaminar whole surface of gel rubber material, or with the mixed uniformly sanitary towel of absorption bulk material of core in absorb the consumption of gel rubber material, so this sanitary towel can use lower cost manufacturing.

Increase in the border area density that absorbs gel rubber material, can also by with core from folding in its limit portion, maybe will contain another that absorb gel rubber material stacking put on the border area of absorbent cores of fiber realized.

From European patent application EP-A-0217666, can recognize a kind of sanitary towel that between its core and top flat, is placed with two or many superabsorbent material bands.A large amount of body fluid can be promptly collected in zone between these absorption bands, particularly urinates, however the core below being positioned at super absorption band, the horizontal proliferation of liquid still clearly takes place.There is tangible liquid crossflow moving on the collecting region of broad.

According to embodiment of sanitary towel of the present invention, the width that it is characterized in that collecting region is 5 to 28 millimeters, preferably about 15 millimeters.

By narrow relatively central collecting region is provided in sanitary towel, make body fluid, particularly menstruation mainly is mobile having increased in the vertical.After the change of absorption gel rubber material was wet, these materials expanded and demonstrate the Liquid Absorption rate and reduce, and so-called " gel blockage " phenomenon promptly occurs.The gel blockage that the absorption gel rubber material of relatively small amount causes in collecting region is also less and demonstrate less flow resistance.On the border of collecting region, owing to become the gel blockage of the absorption gel rubber material that wets, and the horizontal proliferation of liquid is reduced.So entering the longitudinal diffusion of the liquid of collecting region improves.Along with the minimizing of the amount of the absorption gel rubber material in collecting region, the narrow relatively size of central collecting region force the liquid that enters this district concentrate on absorbent item vertically on.

According to absorbent item of the present invention, the embodiment of sanitary towel particularly, it is characterized in that absorbing in the collecting region density of gel rubber material at 0 to 3.59 gram/square feet, the density that absorbs gel rubber material in the border area is 2 to 7.5 gram/square feet for gel strength after being exposed in the synthetic urine in improved AGEP test less than the absorption gel rubber material of 1.2kPa, is 2 to 15 gram/square feet for be exposed to the synthetic gel strength afterwards of urinating in the solution in improved AGEP test greater than the absorption gel rubber material of 1.2kPa.

The absorption gel rubber material of low gel strength in the border area, the absorption gel rubber material of the Aqualon C board of producing such as the Hercules company of Wilmington Del, can cause undesirable gel blockage phenomenon if density is higher than 7.5 gram/square feet, the gel blockage parts transversely that it makes the liquid of pouring into collecting region pass the border area flows.If in the border area, absorb gel rubber material density be lower than all properties that 2 gram/square feet can make sanitary towel be reduced to one unfavorable low-level.Absorption gel rubber material for high-gel strength, as Aquakeep13 SHPS, a kind of by Autochem S.A., Cours Michelet, La Defense, Paris, sodium polyacrylate and Sanwet IM 5600-S that France produces, a kind of by Farbwerke Hoechst AG of Frankfurt, Germany, produce by the grafted crosslinked starch of sodium acrylate, if density greater than 15 gram/square feet, just may cause undesirable gel blockage phenomenon.

Fibrous layer is pressed to form a passage on it is characterized in that in collecting region according to another embodiment of absorbent item of the present invention.

If in the border area of a stacked absorbent cores (wherein absorbing gel rubber material between two-layer fabrics), will absorb gel rubber material, preferred granulated gel material, cloth becomes uniform one deck, saves at collecting region so to absorb gel rubber material and will stay next idle space up and down between the fabric by what absorb that gel rubber material fills.By upper layer of fabric being compressed into the free space of collecting region, just in absorbent cores, constitute a passage, it can be assisted and collect and distribute body fluids.

Replace top fabric is pressed into collecting region, can use a kind of hygroscopic material, as a kind of by for example polyester fiber curl or the elastomeric fabric replacement of low-density collecting region that the synthetic fibers such as PET fiber of winding constitute in the absorption gel rubber material.Moistening preferably can realize by handling collecting region with a kind of wetting agent such as surfactant.

Should be noted that, from EP-A-0173068, learn, move in order to promote the liquid on absorbent item is vertical, and proposed a kind of sanitary towel with vertical passage.But do not mention about in the lateral core material of this passage, whether having and absorb gel rubber material and the density of absorption gel rubber material in the zone at passage place in absorbent item.

Another embodiment of sanitary towel according to the present invention, it is characterized in that top all is to be made of one deck fabric with following fibrous layer, said fabric has two relative vertical edges that are stacked on the collecting region.

In the time will absorbing gel rubber material and be enclosed in the woven, its edge is just overlapping with collecting region, and additional one deck fabric is used to the absorption of the liquid accelerating to gush out and improves the wicking effect in collecting region.

Introduce some embodiment of absorbent item of the present invention below with reference to accompanying drawings in detail.In these accompanying drawings:

Fig. 1 represents the top plan view of sanitary towel, and wherein the overlapping layer part has been cut open to show following structure, and sanitary towel generally has a straight core;

Fig. 2 represents to have the top plan view of the sanitary towel of shaping core;

The profile of health JINYAN cross central line 16 in Fig. 3 presentation graphs 1;

Sanitary towel in Fig. 4 presentation graphs 3, it does not absorb gel rubber material in collecting region;

Sanitary towel in Fig. 5 presentation graphs 4, the fabric above it is pressed into collecting region;

There is a passage in sanitary towel in Fig. 6 presentation graphs 5 on it slice;

Sanitary towel in Fig. 7 and Fig. 8 presentation graphs 3, a woven is sealed the absorption gel rubber material, and vertical edge of fabric is eclipsed;

Fig. 9 a and Fig. 9 b represent the embodiment of another absorbent cores of sanitary towel of the present invention;

Figure 10 represents according to the present invention about the curve chart of sanitary towel's liquid distribution under various loads;

Figure 11 represents another embodiment of the absorbent cores of sanitary towel of the present invention.

The embodiment of the absorbent item in the accompanying drawings belongs to disposable sanitary napkin, is promptly passed by the women to be used to absorb and to hold various Excretas (for example, blood, menstruation and urine) of discharging in the body and the articles for use of just throwing away near the pudendum after using once.But the present invention is not limited only to sanitary towel, but also comprises other absorbent item, and as the pants that women, child use, its absorbance is generally lower than sanitary towel.Although the embodiment of Xiang Ximiaoshuing has so-called " lamination " core in the accompanying drawings, wherein absorb gel rubber material and be as the one deck between two, but the present invention is not limited thereto, also can make absorption gel rubber material and fiber mixing in the core, as by Procter; Camble company is in the U.S. Patent application NO.07/810 of December in 1991 application on the 17th, the introduction in 774, this patent is incorporated by reference here.

Sanitary towel 1 shown in Figure 1 comprises the top flat 3 of liquid permeable, the absorbent cores 5 below top flat and the bottom 7 of liquid impermeable.Core 5 has two

vertical limits

9 and 11, and they are generally along the longitudinal extension of the vertical loyal line 13 of core 5.As shown in Figure 2, vertically

limit

9,11 needs not be straight and can be sweeping towards longitudinal centre line, to constitute a kind of effigurate core.Absorbent cores 5 can be used to distribute and flow to the collecting layer covering of the liquid of absorbent cores 5 through top flat 3 with one or more layers.For the sake of clarity, in the sketch map of Fig. 4 to 8, all omitted the collecting layer.Shown in Fig. 3-6, absorbent cores 5 is a laminated construction, wherein absorbs between the fabric 25 that gel rubber material is placed on the fabric 24 on upper strata and

lower floor.Fabric

24,25 can be as the part at the monolayer of sealing absorption gel rubber material 29 as shown in Fig. 7,8,9.

A central collecting region 15 is arranged on core 5, and what be adjacent has two border areas 17 and 19.Central authorities receive the density that absorbs gel rubber material in the district 15 and are lower than the border area, density in the

border area

17,19 for for the absorption gel rubber material of low gel strength between 2 to 7.5 gram/square feet, preferably be about 5.5 gram/square feet, for for the absorption gel rubber material of high-gel strength between 2 to 15 gram/square feet, preferably be about 10 gram/square feet, in collecting region 15, preferably should be 0 gram/square feet.

The density that absorbs gel rubber material does not need rapid variation from the border area to the collecting region, but can for example linearly from high to low reduce, or according to the change of shape of other any needs.

The width W of collecting region, preferably narrow than absorbent cores 5 the narrowest width L, value is at 5 to 28 millimeters.As shown in Figure 2, for the sanitary towel of the core 5 with definite shape, the narrowest lateral dimension L of sanitary towel is positioned at cross central line 16 places, and the size of collection is about 70 millimeters.Vertically there are two horizontal flangings or flank in sanitary towel 1 in the periphery place at it, and it can be used to amount on the trousers edge of user so that sanitary towel locatees with respect to trousers on width and the minimizing side pollutes.

More specifically consider some parts of sanitary towel, in general absorbent cores 5 can be any compressible, comfortable, non-irritating to wearer's skin, can absorb and hold the material of slop.Absorbent cores 5 can be made various sizes and different shape (for example rectangle, water leak shape, or the like).A kind of shape of preferred absorbent cores 5 is Os Canitis shapes shown in Figure 2.This preferred absorbent cores 5 about 22.0 centimeter length (longitudinal size of centrage 13 longitudinally) are in the middle along cross central line 16 about 7.0 centimetres wide (lateral dimensions).For easy manufacturing, the structure of absorbent cores 5 is symmetric, so the wearer need not consciously sanitary towel to be worn on the direction at it to ajust.The structure at middle part basically with wearer's thigh and wearer's crotch place fit, to prevent unnecessary fold.The size that can change absorbent cores 5 is with the amount of the drained liquid volume that adapts to different wearers and expection dimensionally.Absorbent cores 5 can be bonded at respectively on adjacent part such as top flat 3 and the egative film 7 as spray glue or cementing line or bounding point main upper surface and the lower surface with core with any methods known in the art.In use being kept perfectly property and restorability are kept best trap easily thereby this bonding mode makes absorbing material.Preferably, the wet Zhang Qiangdu of absorbent cores 5 on transverse direction is at least every centimetre of about 100.0 grams.Wet Zhang Qiangdu is determined by ASTM standard D 829-29.

Absorbent cores 5 can be with the various liquid absorption material manufacturings that are generally used for disposable sanitary napkin, diaper or other absorbent item.The example of the absorbing material that is fit to comprises wood pulp, the cellulose wadding of creep, the absorbing foams of the pulverizing that is commonly referred to as the air felt, absorbs sponge, synthetic artificial fiber, polymer fiber, the polymeric gel agent of formation hydrogel or the combination of any material that is equal to or these materials.A kind of particularly preferred absorbing material is to absorb gel rubber material or polymeric gel agent.The polymeric gel agent is more such materials, and they contact as water or body fluid with fluid (being liquid), just absorbs this liquid and forms hydrogel thus.By this way, the liquid of pouring into absorbent cores 5 can be aggregated gel collection and maintenance, thereby makes articles for use of the present invention have enhanced absorption rate and/or improved liquid retainability energy.

The polymeric gel agent that is used for absorbent cores 5 is generally by water-fast basically, and lightly crosslinked, part is neutral, and the granule that can form the polymeric material of hydrogel constitutes.This polymeric material can be by polymerisable, and undersaturated, acidiferous monomer makes.Be used to prepare the suitable unsaturated acid monomer that is applicable to polymeric gel agent of the present invention and comprise that those are listed in US-A-4,654, material in 039, this patent name is " polymer composition that is used for the formed hydrogel of absorbing structure ", authorize Brandt on March 31st, 1987, Goldman, and Lnglin, and quote as a reference in the present invention.Preferred monomer comprises acrylic acid, methacrylic acid and 2-acrylamido-2-methyl propane sulfonic acid.Acrylic acid itself is the particularly preferred material that is used to prepare the polymeric gel agent.

In the polymeric gel agent that can form hydrogel, can be grafted on by the polymeric part undersaturated, that acidiferous monomer constitutes on the polymeric component of other type as on starch or the cellulose.Such polyacrylic acid grafted starch material here is preferred especially the use.

The preferred polymeric gel agent that can make from the monomer of general type comprises acryionitrile grafted starch, polyacrylate graft starch, the polyacrylate of hydrolysis, the copolymer and the compositions thereof of maleic anhydride base.Particularly preferably be polyacrylate and polyacrylate graft starch.

No matter be used for what the character of basic polymeric component of polymeric gel agent of the formed hydrogel of absorbent cores 5 of the present invention is, this material generally all is lightly crosslinked.Crosslinkedly make that be used for the polymeric gel agent that forms hydrogel of the present invention becomes water insoluble basically, so crosslink part ground has determined the volume of gel and from the characteristic of the polymer that extracts of the hydrogel of used polymeric gel agent formation.Suitable crosslinking agent is known in the art, for example comprises that those at length are recorded in US-A-076, the cross-linking agent in 663, and this patent was authorized Masuda on February 28th, 1978, and is incorporated by reference here.Preferred cross-linking agents is the di esters or the polyester of undersaturated monocarboxylic acid or polycarboxylic acids and polyhydric alcohol, bisacrylamide and diallylamine or triallylamine.Particularly preferred cross-linking agent is N, N '-methylene-bisacrylamide, trimethylolpropane tri acrylate and triallylamine.Cross-linking agent generally accounts for about 0.001 molar percentage to 5.0 molar percentages in the polymeric material of the prepared hydrogel that forms.More preferably contain the cross-linking agent of 0.01 molar percentage of having an appointment being used for the polymeric gel agent that forms hydrogel of the present invention to 3.0 molar percentages.

The polymeric gel agent lightly crosslinked, that can form hydrogel that can be used in the articles for use of the present invention generally is to be used with the neutral form of their part.For purpose of the present invention, when at least 25.0 molar percentages that are used to constitute polymer preferably the monomer of at least 50.0 molar percentages be when having contained the acidic group monomer with salt-forming cation is neutral this material to be considered to part neutral.Suitable salt-forming cation comprises the ammonium and the amine ion of alkali metal, ammonium, replacement.The monomeric percent of acidic group that contains that is neutralized in all used monomers is referred to as " degree of neutralization " here.

The polymeric gel agent material that is used for the absorbent item shown in Fig. 3 and 8 must have the absorbance that higher comparatively speaking absorption enters the liquid in these articles for use.The absorbance of these materials can be by determining with reference to " gel volume " of selecting the used polymeric gel agent of the present invention for use.

Be used for purpose of the present invention, gel volume can define scorching in the amount of the synthetic urine of any polymeric gel agent absorption that provides, the gram number of the synthetic urine that particularly every gram polymeric gel agent absorbs.Gel volume in synthetic urine can be determined by dry polymeric gel agent to be measured of preparation 0.1-0.2 part and 20 parts synthetic urine suspension.This suspension at room temperature slowly stirs one competent period, and for example about 1 hour, to reach the expansion balance.The gel volume of polymeric gel agent can be from suspension the agent of every gram polymeric gel the percentage by weight of the gram number of synthetic urine and the ratio that forms the shared volume of the liquid of hydrogel and the cumulative volume of suspension are calculated.

The gel volume that is used for the gel of absorbent cores 5 generally is at least the synthetic urine/every gram polymeric gel agent of about 20.0 grams.More preferably, the gel volume of material therefor is about 20.0 to about 60.0, more preferably about 22.0 to the synthetic urine/every gram polymeric gel agent of about 35.0 grams.

In a preferred embodiment, sanitary towel is 70 millimeters along the core width of the minimum of cross central line 16, and central collecting region 15 comprises 0 to 3.5 gram/square feet, and more preferably the such polymerization of 0 gram/square feet absorbs gelatinous mass.The width W of collecting region 15 is 10 to 20 millimeters, preferably about 15 millimeters.The density that polymerization absorbs gel rubber material in

border area

17 and 19 is uniform distribution preferably, on the direction of cross central line, be constant promptly, for width W is that 15 millimeters collecting region density is 4 gram/square feet, for width is that 20 millimeters collecting region density is 5.5 gram/square feet, and the gross density that absorbs gel rubber material in the core is about 3.1 gram/square feet.Sanitary towel's preferred sizes, the density of the width of collecting region and absorption gel rubber material relates to the absorbent item shown in Fig. 2-8, promptly has the sanitary towel of the laminated construction of shaped core 5 and air-flow tissue layer 24 into the net and 25.The gel strength of absorption gel rubber material 29 that is used for the preferred embodiment of the invention is less than 1.2kPa.But the collecting region with low-density absorption gel rubber material also can advantageously be used in combination with the absorption gel rubber material of high-gel strength, and it can and the gel blockage phenomenon can not occur with higher density use.

The density of absorption gel rubber material and the width of central collecting region can change according to gel strength, all different absorption gel rubber materials, the thickness of absorbent cores and the smallest lateral dimension L of absorbent cores in the border area.

The gel strength that absorbs gel rubber material can be measured according to improved absorption gel expansion experiment (AFEP).Improved AGEP experiment measuring gel is exposed at it and absorbs expansion back applied force in synthetic urine solution.Said power is to measure with the annular pressure boots in the sample cavity that tightly is fixed on one 2 cm diameter, and said sample cavity is by Ametek company, Mansfield ﹠amp; Brown branch, 8600 Somerset Drive, Largo, Florida46543, the sample cavity of the accurate object stage of the C1359 type Ametek that USA produces.Ergometer is by Brown Tool ﹠amp; Supply company, Solon, Ohio, " Accuforce " device that USA produces.

Adopt following step:

1. weigh up 0.179g+/-0.001g polymeric gel agent material puts into absorbing cavity.

2. the chamber that will contain sample is put on the fine setting carriage of the accurate desk-top ergometer of Ametek, adjusts sample holder so that pressure shoe is in the center in putting pipe into the time.

3. in sample, add the synthetic urine of 56x Jayco load (10ml) (see and explain 1).

4. with the lift arm of Ametek testing stand, sample is brought up to the position that makes pressure shoe almost touch liquid.

5. with the zero clearing of Ametek ergometer,, be 1cm/Min with its speed height if use curvilinear recorder.

6. illuminator is turned off.

7. utilize the coarse adjustment and the fine setting of accurate platform, it is mutually neat with the top of pressure shoe that sample is risen to liquid level.This can observe and realize by passing pressure shoe.Liquid on the absorbing cavity wall is owing to surface tension demonstrates a leucorrhea.When moving on this leucorrhea is in the chamber, it will block the pressure shoe of silver color.When this leucorrhea is positioned on the top of pressure shoe, the silver color band will occur once more.Disappear up to the silver band with the fine setting adjusting at this point place lower than sample.

8. immediately illuminator is turned off.

9. when gel arrives pressure shoe, intervalometer is arranged on 30 minutes and with its startup.

10. do not write down power value (with the gram value) at 5,10,15,20 and 30 minutes.

Calculate

Area (the cm of the reading of pressure=device (g)/pressure shoe ²) * 98.1(kPa)

Note

1.Jayco synthetic urine

The synthetic urine of Jayco is that the amount of these chemical compounds below adding in every liter of solution constitutes.

Na ₂SO ₄2.0g/l

Kcl 2.0g/l

（NH ₄） ₂HPO ₄0.15g/l

（NH ₄）H ₂PO ₄0.85g/l

MgCl ₂∶6H ₂O 0.5g/l

CaCl ₂∶6H ₂O 0.25g/l

2. testing used equipment and sample should be under 25 ℃ the equilibrium temperature.

3. so the pipe interior diameter is that 2 centimetres of pressure shoe surface areas are 3.14cm ²

Still be listed in high-gel strength with the post-absorption gel strength in 5 minutes and absorb gel rubber material, and can in the border area, use with high density greater than the absorption gel rubber material of 1.2kPa.The preferred gel strength that absorbs gel rubber material clocklike is increased to the value that exposes after 30 minutes from the value that exposes 5 minutes usually.

In the preferred embodiment shown in Fig. 3-8, absorbent cores 5 is a kind of laminated construction, and it comprises that one is placed on the absorption gel rubber material between the fabric 24 and 25 of two-layer air lay.A kind of suitable lamination is the WATER-LOCK L-535 absorption lamination (WATER-LOCK is the trade mark by Grain Processing register of company) by the Grain Processing company product of Muscatin Iowa.This super absorption lamination is disclosed in authorized people's such as Pedersen on August 21st, 1984, its denomination of invention is the US-A-4 of " composition and method of making the same that is used for absorbing membrane ", 467, in 012 patent and the denomination of invention of authorizing people such as Lindsay on April 7th, 1981 be the US-A-4 of " lamination absorption process ", 260, in 443 patents, these patents are here quoted as a reference.The aquogel polymer load is every square centimeter 0.005 gram among the WATER-LOCK L535, but the load that has been found that every square centimeter of 0.001-0.009 gram is acceptable.First and second tissue layer 24 and 25 provide a space that holds the absorbing polymeric material, have improved absorbed Excreta and have overflowed the horizontal absorption of absorbent cores 5 and guaranteed absorbing power.Form in the polymeric gelling agent of hydrogel in the non-particulate type that can be formed in fibrous layer, foam or thin film, the content of non-particulate type gel can be about 15% to about 100% of the weight of absorbent cores 5, more preferably about 40% to about 100%, most preferably about 60% to 100%.Two kinds of suitable commercially available non-particulate type absorbing materials that are used for the low gel strength of absorbent cores 5 are by Higashi, Osaka, the trade name that the Choli limited company of Japan produces is a kind of double-deck tacryl material of Lanseal F and by Wilmington, the Hercules of Del, the trade name that Inc. produces is the carboxymethyl cellulose fiber material of Aqualon C.

The Excreta load that the absorbance of absorbent cores 5 should design with the application target for sanitary towel is consistent.In addition, the absorbance of absorbent cores 5 be can change expect the scope of excretory liquid volume amount to adapt to wearer.For example, daily type can have different absorbances with sanitary towel night using type, and that perhaps gives juvenile women's use should have different absorbances with the sanitary towel that those adult females use.

The fabric 31 of wet-laying can overlay on the absorbent cores 5 and extend 3 millimeters from the

edge

9 and 11 of absorbent cores 5.The fabric 31 of this wet-laying is a liquid permeable.The basis weight of gratifying fabric 31 is about every square metre 15.8 gram, and the air transmission coefficient under the pressure reduction of about 12.08 millimeters of water is 30.5 cubic metres every square metre.

Keep globality when preferably, the fabric 31 of this wet-laying is in use wetted.The fabric 31 of this wet-laying preferably restrains for every centimetre 15.0 approximately at the wet tensile strength of cross-sectional direction.The fabric 31 that is suitable for and their manufacturing thereof are disclosed in and authorized Sanford and Sisson on January 31st, 1967, denomination of invention is the U.S. Pat-3 of " making the method for absorption paper and the paper of manufacturing by the mode of printing fiber hinge joint pattern on the paper before dry ", in 301,746.This patent at this as a reference.In a preferred embodiment, those parts of extending out from vertical limit 9 and 11 of absorbent cores 5 of the fabric 31 of wet-laying link to each other with egative film 7.The fabric 31 of this wet-laying can utilize the spray glue method of in prior art known method of attachment such as bonding wire or point to be connected with egative film 7.The fabric of this wet-laying has a lot of effects.Thereby fabric 31 is used to seal any loose superabsorbent material 37 that is placed between cotton paper 31 and the egative film 7 prevents that superabsorbent material 37 from contacting with human body skin.Thereby fabric 31 also is used for improving the excremental horizontal absorption that sucks absorbent cores 5 makes the excremental distribution on the absorbent cores 5 more even.In addition, fabric 31 also has absorbance to a certain degree and can further prevent to arrive and absorbs chip and be absorbed the skin that Excreta that core 5 absorbs rehumidifies the wearer.

Overlay on the fabric 31 of wet-laying can be that wiping of liquid permeable smeared and collected sheet 33.In a preferred embodiment, wiping and smearing collection sheet 33 is nonwoven sheet, as is made into the oblique textured fiber sheet of 70%/30% netted rayon/polyester.Suchly be made into netted fiber by E.I.Dupont Nemours and Company of Wilimington, Delaware makes, the trade name that can buy from the market for " SONTARA(SONTARA is the trade mark by E.I.DupontNemours P Company registration).These fibers have the suitable model of many kinds, but model 8407, owing to it the mesh style and every square centimeter 0.005 the gram basis weight and about 0.04 millimeter thickness become preferably.This is wiped to smear and collects sheet 33 and extend out from the edge of the fabric 31 of wet-laying and also link to each other with egative film 7.Wipe to smear and collect sheet 33 and combine the excremental horizontal absorption that has greatly improved on the absorbent cores 5, make the more uniform distribution of Excreta on the absorbent cores that enters with central collecting region 15.It is very important wiping and smearing that the horizontal absorption of collecting sheet 33 combines for following argumentation with the longitudinal diffusion of liquid in central collecting region 15.Sanitary towel in the bigger prior art of many volumes only depends on the vertical absorption of the height on the point of Excreta initial deposition.In other words, because the absorbent cores of this sanitary towel is quite thick, they can absorb a large amount of Excretas by its thickness, and have only utilized the very little part of its surface area or its horizontal absorbance.Yet the vertical by comparison absorption of thin sanitary towel 10 of the present invention is just less.So, for a large amount of relatively absorbed Excretas, use can be laterally and longitudinally, thereby Excreta is distributed to make on the high surface area of absorbent cores 5 that Excreta can vertically be sponged faster and better wipe to smear and collect sheet 33, with central collecting region 15, be very ideal.

Overlay to wipe and smear that to collect on the sheet 33 be the top flat 3 of liquid permeable.In a preferred embodiment, top flat 3 and wiping is smeared and is collected sheet 33 and is the top flats 3 by spray glue and wipes and smear surperficial bonding the linking together of collecting sheet 33.Top flat 3 is submissive, soft feel, non-irritating to wearer's skin.In addition, top flat 3 is liquid permeable, can make liquid pass its thickness at an easy rate.The top flat 3 that is fit to can be by a variety of materials manufacturing such as polymeric material, the thermoplastic film of molding, foraminous plastic foil, porose foam, reticulated polymer foam, natural fiber (for example, wood or cotton fiber), synthetic fibers (for example polyester or polypropylene fibre) or natural and compositionss synthetic fibers, wherein preferably foraminous form film.Why form film preferably is because they are permeable for liquid and do not absorb liquid as top flat 3.Therefore the surface that contacts with human body of form film keeps dry, thereby has reduced the chance of the health of making dirty and created more comfortable sensation for the wearer.Suitable form film is disclosed in the following United States Patent (USP), US-A-3, and 929,135, denomination of invention is " having taper absorbing structure capillaceous ", December was authorized Thompson on the 30th in 1975; US-A-4,324,246, denomination of invention is " disposable absorbent article of anti-pollution top flat ", authorizes Mullane and Smith April 13 nineteen eighty-two; US-A-4,324,314, denomination of invention is " elastic-plastic fabric with like fibrous character ", authorizes Radel and Thompson August 3 nineteen eighty-two; US-A-4,463,045, denomination of invention is " having the three-dimensional plastic fabric that the macroscopic view of mat surface and sense of touch as cloth is expanded ", and on July 31st, 1984 was authorized Ahr Louis Mullane and Ouellette: above patent is incorporated by reference in this application.

In a preferred embodiment of the invention, the surface of top flat 3 is hydrophilic.Comparing hydrophilic surface with non-hydrophilic surface can help liquid to see through top flat 3 quickly.This has reduced menstruation and has flowed out top flat 3 and be not absorbed the probability that core 5 absorbs.In a preferred embodiment, the surface of top flat 3 is by the surface being handled the hydrophilic body surface made from a kind of surfactant.Preferably, surfactant is distributed on the surface of top flat 3 substantially equably and fully.This can utilize in this area any known ordinary skill to finish.For example, surfactant can utilize spraying, smears, or carries to roll and be applied on the top flat.This external surfactants can also mix in the polymeric material that constitutes film topsheet between the nonwoven top flat fiber or within.

Egative film 7 is adjacent with absorbent cores 5.In a preferred embodiment, absorbent cores can be fixed on the egative film 7.Any technology known in the art all can be used for this purpose as spray glue or linear or some shape adhesive coating.Egative film 7 has generally been determined the outer surface of sanitary towel.Egative film 7 can be any impenetrable liquid and prevent to being absorbed and retained in the medicated clothing that the Excreta in the absorbent cores 5 is made dirty and contacted with the outer surface of sanitary towel, as the material of underpants.In a preferred embodiment as shown in figs. 1 and 6, egative film 7 is the barrier layers made from thin plastic.The material of other softish liquid impermeable also can use.Preferably, egative film 7 is that thickness is about 0.012 millimeter to about 0.051 millimeter polyethylene film.As used here, term " softish " refers to material therefor quality soft general shape or profile easy and human body and fits.

Suitable polyethylene film is No. 8020 thin film of being produced and being sold on market by Monsanto chemical company.Egative film 7 is preferably handled and is made it have more the same outward appearance of cloth through embossing and/or surface roughening.In addition, thus egative film 7 should allow steam to run out of from absorbent cores 5 prevents that Excreta from overflowing egative film 7.

Preferably, thus the length of top flat 3 and egative film 7 and width are generally greater than absorbent cores 5 that they extend the

edge

9 and 11 and link together by rights of absorbent cores 5.As used herein, term " connection " comprises structure that one of them first parts and one second parts directly link to each other and wherein by first parts are fixed on the intermediate member, and this intermediate member is fixed on the structure that the mode on second parts links to each other first parts and second parts indirectly.In one embodiment, egative film 7 and top flat 3 be oval-shaped and extend absorbent cores 5 at least about 1 centimetre distance, and they utilize that attachment means known is connected to each other directly together in the prior art at extended spot.Connected mode can be for example even successive tack coat, the array with the tack coat of certain pattern or the bonding wire that separates or adhesive spots.

In Fig. 4, collecting region 5 does not comprise that absorb gel rubber material therefore can compress into collecting region 5 and form a passage 30 as shown in Figure 5 going up synusia 24.Also top flat 3 can be compressed into passage 30 so that a groove longitudinally to be provided on a side of sanitary towel and Body contact, this helps to increase the longitudinal diffusion of liquid along top flat 3.As shown in Fig. 7 and 8,

sheet

24 and 25 can be the part of its side and collecting region 5 eclipsed monolithics up and down, thereby the auxiliary liquid that absorbs in the vertical of the additional fabric of one deck is arranged in collecting region.Fig. 9 a and 9b represent that how produced by one piece material 35 absorbent cores is, the band 37 that wherein contains low-density absorption gel rubber material is that symmetry is placed.Sheet 35 is done e shape folding after, low-density absorbs gel rubber material band 37 is positioned at collecting region 15 shown in Fig. 9 b center.

In the embodiment shown in fig. 11, the layer of absorbent cores 5 24 and 25 is folded in half, thus in the

border area

17 and 19 places, absorbent cores comprises two-layer absorption gel rubber material, and has only one deck to absorb gel rubber material at central collecting region 15.Can comprise hydrophilic fabric or not have grain material, or the layer of absorbent 30 of hydrophilic coating can be extended in the bottom of collecting region 15 and the interlayer of the absorption gel rubber material 29 in

border area

17 and 19.

Replacement can contain a pair of contain the fibrous layer that absorb gel rubber material on of a pair of fibrous layer that separates below the place, border area overlays that absorbs gel rubber material with the folding method that obtains double-deck absorption gel rubber material of core in 17 and 19 places in the border area.Fibrolaminar open side can be used for example PUR 26 sealed-off.

Should be noted that collecting region 15 need not extend on the whole length of absorbent cores 5, but only overflow from the not end of absorbent cores to prevent liquid at the middle section of absorbent cores.

In order to prove that sanitary towel of the present invention compares with a kind of similar sanitary towel that has equally distributed absorption gel rubber material on the whole surface of absorbent cores and has enhanced properties of product, and sanitary towel is got wet with the mode that progressively increases load.Experiment condition and the experiment product will provide below.Experimental results reduction is in table I, II, III and Fig. 9.

The product of being tested

Reference product comprises the shaping laminated core, and its length is 207 millimeters, is 70 millimeters along the width of cross central line 16.The use density of the absorption gel rubber material of the L-074 model that can buy from Shokubai is 5.5 gram/square feet.

The sanitary towel of the present invention of being tested comprises first type, and its central collecting region width is 15 millimeters and does not contain absorption gel rubber material (A type); With second type, its central collecting region width is 20 millimeters and does not contain absorption gel rubber material (Type B), all is 5.5 gram/square feet for the density that absorbs gel rubber material in A type and the Type B border area.The size of sanitary towel of the present invention is consistent with reference product with the making material.

Load and width distribution

In order to measure the ratio of liquid horizontal proliferation and longitudinal diffusion under the different loads condition, sanitary towel to be got wet with the paper industrial liquid, the viscosity of said liquid is 16.5cps, wherein comprises:

Glycol 80g/l

Sodium chloride 10g/l

Sodium bicarbonate 4g/l

Carboxymethyl cellulose 18g/l

Sanitary towel is launched into an even curface, the center of absorbent cores 5 is marked on the top layer of each sanitary towel.As shown in Figure 2, the center of absorbent cores 5 is corresponding to the cross point of longitudinal centre line 13 with cross central line 16.2 milliliters liquid were added to the center of sanitary towel in 4 seconds with the PA-SF 5 type compressor pumps of IKA product.Finish charge into 5 minutes after, measure the solstics that liquid reaches on the direction of longitudinal centre line 13 and cross central line 16.Provided reference product and had 20 millimeters results that do not contain sanitary towel's liquid width under different loads of the collecting region width (Type B) that absorbs gel rubber material in the table I.

The comparison of table I load and width distribution

Load (ml)	The dispersion of distribution (cm) reference product Type B
			2	4.1	4.0
6	6.6	5.8
			10	7	6.5
12	7	6.8
			14	7	7

Demonstrate for the sanitary towel with central collecting region from the table I, liquid arrives

vertical edge

9,11 of core 5 after absorbing 14ml liquid, and at this load value place, the dispersion of distribution equals the narrowest width of absorbent cores, promptly 70 millimeters.This means the effective absorbance of effective absorbance of the sanitary towel with collecting region greater than reference product, for reference product, when 10 milliliters load value, liquid just reaches 9,11 places, vertical edge of this product.

The comparison of length and width distribution

According in above-mentioned experiment to the length of liquid distribution and the measurement of width, calculate A type sanitary towel (width of collecting region is 15 millimeters) and have and do not contain the length of liquid distribution of sanitary towel's (C type) that the density that absorbs gel rubber material, measures collecting region that width is 25mm, absorbs in the border area gel rubber material is 5.5 grams/every square feet and the ratio (l/w) of width.To another kind of similar with the A type, but the density that absorbs gel rubber material in collecting region sanitary towel of (D type) between 1-2 gram/every square feet also tests.For sanitary towel's (A type, C type and reference product) of each type, three samples all use the mode that progressively increases liquid load to get wet.Average length and the ratio of width and the result of standard deviation (av.and st.dev) each time is summarized in the table II about three samples of A type, C type and reference product.For D type sanitary towel, only there is a sample to be got wet, thereby do not obtain standard deviation for such sanitary towel with the mode type that progressively increases load.

As show II, clearly more shown from Figure 10, than width distribution, with respect to the load greater than 6ml, comparison increases according to product liquid to some extent in the length with the sanitary towel that does not contain the collecting region that absorbs gel rubber material.By comparing the result of A type and D type, it can also be seen that, in collecting region, do not contain and absorb gel rubber material and can cause bigger length and width distribution, and too high absorption gel rubber material density will cause comparing the length that reduces according to product and the ratio of width in collecting region.For width is 15 millimeters collecting region, and its length and width distribute, and to be better than width be 25 millimeters collecting region.

The table II

Length compares width distribution

Repeat to see through experiment

For A type and C type sanitary towel, the contrast reference product adopts the mode that progressively increases load to carry out the experiment of the time that sees through.Sanitary towel is placed on the flat surface, and the center of absorbent cores is marked on the top flat.An electronics sees through the center of the Kong Yuxin of dish, and 2ml liquid is injected the hole that sees through dish with funnel.With with see through that dish links to each other and if all liq flows away from dish it just stop to count carry out " record " through timer.Liquid is emitted continuously by seeing through dish, and the time is by seeing through the intervalometer record.After 60 seconds, there is the liquid load of 2ml from funnel, to be injected in the sanitary towel, this process repeats all to charge up to 14ml liquid.Three samples of A type, C type and reference product all carry out the loading experiment of every kind of load, the meansigma methods that the time of seeing through is got these products.The result is summarized in the table III.Find out that from the table III for the C type product with big collecting region width (25mm), the time of seeing through is the shortest.The temporal differences that sees through with respect to reference product becomes more obvious for bigger load (greater than 6ml).

The table III

The time of seeing through

Claims

1, sanitary towel, it comprises the top flat (3) that can see through liquid, can not see through the egative film (7) of liquid, and be arranged on absorbent cores (5) between top flat and the egative film, said absorbent cores (5) comprises two vertical edges (9,11), central authorities' collecting region (15), be positioned at central collecting region (15) and vertical edge (9,11) two border areas (17 between, 19), said core 5 also comprises and contains the layer (24 that absorbs gel rubber material 29,25,29), the density of the absorption gel rubber material in the collecting region (15) of core is lower than border area (17,19) absorb the density of gel rubber material in, it is characterized in that: said absorption gel rubber material (29) is included in fibrous layer and following fibrous layer (24,25) between, the amount that absorbs gel rubber material in collecting region (15) in the fibrous layer of per unit area is lower than the amount that absorbs gel rubber material in the border area in the per unit area, the density that absorbs gel rubber material in the width of the collecting region that is adopted and the border area be suitable for making liquid mainly core vertically on migration.

2, sanitary towel, it comprises the top flat (3) that can see through liquid, can not see through the egative film (7) of liquid, and be arranged on absorbent cores (5) between top flat and the egative film, said absorbent cores (5) comprises two vertical edges (9,11), central authorities' collecting region (15), be positioned at central collecting region (15) and vertical edge (9,11) two border areas (17 between, 19), said core 5 also comprises and contains the layer (24 that absorbs gel rubber material 29,25,29), the density of the absorption gel rubber material in the collecting region (15) of core is lower than border area (17,19) absorb the density of gel rubber material in, it is characterized in that: said absorption gel rubber material (29) is included in fibrous layer and following fibrous layer (24,25) between, border area (17,19) at least than collecting region (15) more and comprise one deck and absorb gel rubber material, the width of used collecting region be suitable for making liquid mainly core vertically on migration.

3, sanitary towel as claimed in claim 2, wherein up and down fibrous layer (24,25) longitudinally edge (9,11) are folding comes, each border area (17,19) comprises at least two pairs of fibrous layers, and one deck absorbs gel rubber material (29) and is included between every pair of fibrous layer.

4, sanitary towel as claimed in claim 2 is characterized in that: layer of absorbent 30 is arranged between the absorption layer of gel material (29) in border area (17,19), and this absorbing material extends the width range of center collecting region (15).

5, sanitary towel, it comprises the top flat (3) that can see through liquid, can not see through the egative film (7) of liquid, and be arranged on absorbent cores (5) between top flat and the egative film, said absorbent cores (5) comprises two vertical edges (9,11), central authorities' collecting region (15), be positioned at central collecting region (15) and vertical edge (9,11) two border areas (17 between, 19), said core also comprises the absorption gel rubber material and absorbs bulk material, preferably fiber or foamy mixed layer, it is characterized in that: this layer is successive, border area and collecting region are arranged in this layer, the density that absorbs gel rubber material in the width of the collecting region that is adopted and the border area be suitable for making liquid mainly core vertically on migration.

6, according to any one the described sanitary towel in the claim 1,2 or 5, wherein the width of collecting region is 5 to 28 millimeters, preferably about 15 millimeters.

7, according to any one described sanitary towel in the claim 1,2 or 5, wherein sanitary towel comprises a cross central line (16), sanitary towel is of a size of 4 to 10 centimetres along cross central line, preferably 6 to 7.5 centimetres, the width of collecting region is 10 to 20 millimeters, preferably about 15 millimeters.

8, according to claim 1, any one described sanitary towel in 2 or 5, the density that wherein absorbs gel rubber material in the collecting region is 0 to 3.59 gram/every square feet, the density that absorbs gel rubber material in the border area is 2 to 7.5 grams/every square feet less than the absorption gel rubber material of about 1.2KPa for be exposed in the synthetic urine back gel strength in improved AGEP experiment, in improved AGEP experiment, be exposed to the absorption gel rubber material of back gel strength in the synthetic urine greater than about 1.2kPa then be 2 to 15 restrain/every square feet.

9, according to claim 1, any one described sanitary towel in 2 or 5, the density that wherein absorbs gel rubber material in the collecting region is 0 to 2 gram/every square feet, preferably about 0 gram/every square feet, the density that absorbs gel rubber material in the border area in improved AGEP experiment, be exposed in the synthetic urine back gel strength less than the absorption gel rubber material of about 1.2kPa be 3.5 to 6.5 restrain/every square feet, preferably about 5.5 grams/every square feet, for be exposed to the absorption gel rubber material greater than about 1.2kPa of back gel strength in the synthetic urine in improved AGEP experiment then is 7 to 12 grams/every square feet, preferably 10 restrain/and every square feet.

10, according to any one the described sanitary towel in the claim 1,2 or 5, it is equally distributed wherein absorbing gel rubber material in the border area.

11, according to any one the described sanitary towel in the claim 1,2 or 5, wherein the length of collecting region is 0.5 to 1 times of core length.

12,, wherein will go up fibrous layer in the collecting region (15) and press down a formation passage (30) according to any one the described sanitary towel in the claim 1,2 or 5.

13,, wherein in collecting region, absorb gel rubber material and replaced with a kind of absorbing material according to any one the described sanitary towel in the claim 1,2 or 5.

14, according to any one the described sanitary towel in the claim 1,2 or 5, wherein collecting region is handled with wetting agent.

15, according to any one the described sanitary towel in the claim 1,2 or 5, wherein collecting region is symmetrical in the longitudinal centre line (13) of sanitary towel.

16, according to claim 1, the described sanitary towel of in 2 or 5 any one, wherein up and down fibrous layer (24,25) is made of woven (35), and said fabric (35) has two eclipsed vertical edges toward each other and in collecting region (15).