CN102257199B - Non-woven fabric - Google Patents

Abstract

Disclosed is a non-woven fabric (10, 110) which comprises composite fibers each comprising a first component and a second component having different melting points from each other, and which has, formed therein, many thermally fused points produced by thermally fusing the intersection points of the composite fibers. When the state of the non-woven fabric (10, 110) is changed from dried state to wet state, the percentage of change in thickness of the non-woven fabric (10, 110) is 15% or more. In a non-woven fabric (10) which is an embodiment of the non-woven fabric, the composite fibers is fibers each comprising a polypropylene resin or a polyethylene terephthalate resin as the first component and a resin having a lower melting point from that of the first component as the second component and has a Young's modulus of 0.2 to 1.0 GPa.

Description

Nonwoven fabric

Technical field

The present invention relates to nonwoven fabric.Nonwoven fabric of the present invention is particularly suitable for for example as the constituent material with the various absorbent commodities headed by menstrual hygiene towel and disposable diaper, using.

Background technology

At present, the face sheet as absorbent commodities such as menstrual hygiene towel and disposable diapers, is widely used nonwoven fabric.In such nonwoven fabric, require to make the liquid supplied with on surface to move to as soon as possible in absorber, on surface the character of residual liquid (liquid residue) not once and make the liquid that is moved not adverse current to the character of nonwoven surface (against returning or getting damp).

If reduce the thickness of nonwoven fabric, generally speaking, liquid residue tails off, but liquid countercurrent becomes many, if strengthen thickness, can prevent liquid countercurrent, but liquid becomes at first and is difficult to move to absorber.In addition, at the residual liquid of the fiber intersection point of the sparse part of fibre density, be difficult to move to absorber, reduce liquid residue and have restriction.Therefore, only merely controlling thickness can not make both with high-level realization.

As the method corresponding to this requirement, known have at the thickness direction of continuous fibers make it to have the method (with reference to patent documentation 1) of hydrophily and fibre density gradient and at the thickness direction of nonwoven fabric, make it to have the method (with reference to patent documentation 2) of hydrophilic gradient.

But, in said method, there is trouble in the processing make it to have gradient, be subject to the restriction of auto levelizer, sometimes cannot obtain the shortcoming of required performance etc.

Prior art document

Patent documentation

Patent documentation 1: JP 2005-314825 communique

Patent documentation 2: JP 2005-87659 communique

Summary of the invention

Liquid residue according to can reduce as uses such as face sheets time and return the novel method of liquid measure, by its use separately or with existing methodical and use, can under condition widely, effectively prevent or alleviate liquid residue and liquid countercurrent.

The invention reside in a kind of nonwoven fabric is provided, it contains and comprises the fusing point composite fibre of different the 1st and the 2nd composition mutually, be formed with the hot melt contact that the intersection point thermal welding between a plurality of these composite fibres forms, while becoming moisture state from drying regime, thickness change is more than 15%.

In addition, the invention reside in a kind of absorbent commodity is provided, it possesses face sheet, back-sheet and the absorber between two sheet materials, and above-mentioned face sheet is above-mentioned nonwoven fabric.

In nonwoven fabric as one embodiment of the present invention, as above-mentioned composite fibre, contain the 1st composition and be acrylic resin or pet resin and the 2nd composition for the resin of the fusing point lower than the 1st composition, the fiber (also this nonwoven fabric being called to nonwoven fabric A below) that Young's modulus is 0.2～1.0GPa.

In nonwoven fabric as other embodiment of the present invention, as above-mentioned composite fibre, contain the thermally extensible fiber that its length is extended because of heating, a face side, there is a plurality of protuberances and recess, form this thermally extensible fiber of this protuberance in their intersection point welding, the heat seal strength on the top of protuberance is higher than the heat seal strength of bottom (below by this nonwoven fabric also referred to as nonwoven fabric B).

Accompanying drawing explanation

Fig. 1 means the ideograph of the device for spinning that can use in the manufacture of low Young's modulus fiber.

Fig. 2 means the stereogram of an embodiment of nonwoven fabric of the present invention.

Fig. 3 is a part of enlarged drawing along the cross section of the nonwoven thickness direction shown in Fig. 2.

Fig. 4 means the ideograph that uses low Young's modulus fiber to manufacture the operation of nonwoven fabric.

Fig. 5 means the figure (figure that is equivalent to Fig. 3) of other embodiment of nonwoven fabric of the present invention.

Fig. 6 (a)～6 (d) is the key diagram of the embodiment action effect of nonwoven fabric of the present invention.

Fig. 7 means suitably the ideograph for the device of the manufacture of nonwoven fabric 110.

Fig. 8 is the ideograph of blowing hot wind portion while seeing from the carriage direction of embossing WEB.

The specific embodiment

Below, based on the preferred embodiment of the present invention explanation the present invention.

Nonwoven fabric of the present invention be contain comprise fusing point mutually different the 1st and the 2nd composition composite fibre, be formed with the nonwoven fabric of the hot melt contact that the intersection point thermal welding between a plurality of these composite fibres forms, the thickness change while being changed to moisture state from drying regime is more than 15%.

Nonwoven fabric as an embodiment of the invention contains the fiber that Young's modulus is 0.2～1.0GPa (below also referred to as low Young's modulus fiber) as the nonwoven fabric that forms fiber.

If nonwoven fabric soaks or form the state of dipping in liquid, the surface tension effects of liquid is in nonwoven fabric.Its result, applies the power that nonwoven thickness is reduced, and by containing low Young's modulus fiber, the thickness of this nonwoven fabric and the fiber spacing in nonwoven fabric are from narrowing down.Thus, the power that absorb from the liquid of absorber is delivered to nonwoven fabric contact skin side more efficiently, and the liquid of nonwoven fabric face side successfully moves from another face side of face side direction of nonwoven fabric.When the face sheet using nonwoven fabric of the present invention as absorbent commodities such as menstrual hygiene towel is used, at the liquid of supplying with towards user's skin one side side, from the face side on this face side direction absorption side, successfully carry out liquid and move.

The Young's modulus of low Young's modulus fiber be preferably 1.0GPa following, more preferably 0.8GPa following, be more preferably below 0.65GPa.Young's modulus is 1.0GPa when following, easily produces the fiber spacing of the nonwoven fabric while absorbing liquid from reducing with thickness, easily obtains the effect that liquid mobility improves.

In addition, the Young's modulus of low Young's modulus fiber be preferably 0.2GPa above, more preferably 0.4GPa, be more preferably 0.5GPa more than.Young's modulus is 0.2GPa when above, and the thickness of drying regime is maintained, and is difficult to cause liquid countercurrent.

In addition, in nonwoven fabric of the present invention, be formed with the hot melt contact (diagram slightly) that the intersection point thermal welding between a plurality of fibers forms.Such hot melt contact can be by forming the WEB that contains Thermoadhesive synthetic fiber and nonwoven fabric enforcement heat treatment.As heat treatment method, preferably hot blast is processed, and particularly preferably the hot blast of ventilating mode is processed.Form the hot melt contact between fiber, preferably at least between low Young's modulus fiber, the hot melt contact that thermal welding forms is contained at mutual intersection point place.In addition, hot melt contact preferably dimensionally disperses conventionally in nonwoven fabric.

Nonwoven fabric, by having the hot melt contact forming between fiber, forms the nonwoven fabric of the caliper recovery excellence after fiber spacing takes out outside nonwoven fabric from the liquid shortening.When face sheet using nonwoven fabric of the present invention as absorbent commodities such as menstrual hygiene towel is used, because the caliper recovery of nonwoven fabric is excellent, be difficult to be moved and return liquid phenomenon (getting damp) to the liquid countercurrent of absorber to face sheet surface.

Nonwoven fabric of the present invention can be both that single-layer nonwoven can be also the nonwoven fabric of sandwich construction.Any situation all preferred at least one face side be take low Young's modulus fiber as main body formation.

For example, during for the nonwoven fabric of single layer structure, the ratio that nonwoven fabric all forms the low Young's modulus fiber in fiber be preferably 50～100 quality %, more preferably 80～100 quality %, be more preferably 90～100 quality %.

On the other hand, during for non-woven fabric with multilayer structure, the ratio that forms the low Young's modulus fiber in whole fibers of nonwoven fabric one side be preferably 50～100 quality %, more preferably 80～100 quality %, be more preferably 90～100 quality %.

The ratio of the low Young's modulus fiber in whole formation fibers of non-woven fabric with multilayer structure be preferably 50～100 quality %, more preferably 80～100 quality %, be more preferably 90～100 quality %.

The Young's modulus that nonwoven fabric forms fiber can operate as follows and measure.

[assay method of Young's modulus]

The thermo-mechanical analysis device TMA/SS6000 that uses Seiko Instruments (strain) to produce.Measuring environment temperature is 25 ℃.As sample, the fibre length of preparing many collections is fiber more than 10mm, and the total weight that makes every fibre length 10mm is 0.5mg, after this plurality of fibers is placed side by side abreast, the distance between chuck of take in device, as 10mm installation, is loaded with certain load state of 0.73mN/dtex.After this, under the condition of 240mN/min, obtain after stress-inflection curves, the gradient of the connecting line of curve when shape is become to 0.1% is Young's modulus.

As low Young's modulus fiber, so long as Young's modulus be 0.2～1.0GPa, by forming the fiber of the hot melt contact that thermal welding forms between the heat treatment of fibre such as hot blast processing, can use without particular limitation.

As the preferred fiber of low Young's modulus fiber, can enumerate sheath portion and contain core-sheath-type Thermoadhesive conjugate fiber that degree of crystallinity that polyvinyl resin (PE), core contain acrylic resin (PP), this acrylic resin (PP) is low etc.

As the preferred fiber of other low Young's modulus fiber, can enumerate sheath portion and contain core-sheath-type Thermoadhesive conjugate fiber that degree of crystallinity that polyvinyl resin (PE), core contain pet resin (PET), this pet resin (PET) is low etc.

As the reason of using these PP and PET in core, due to more cheap than cost with other resin-phase, cause with the poor appropriateness of fusing point of the PE that feel is good, heat sealability is good using in sheath portion gets a promotion in the manufacture of fiber and aspect favourable in the manufacture of nonwoven fabric.

At present, in this Thermoadhesive conjugate fiber, generally speaking, the effect of Thermoadhesive is expressed in low-melting-point resin performance, and resin with high melting point performance maintains the effect of intensity as fiber.On the other hand, when limit makes fibrous refinement limit carry out spinning from molten condition, high-melting-point composition preferentially applies tension force by first solidifying, its result, and the oriented crystalline of promotion resin with high melting point is applicable in maintaining intensity (Young's modulus).

But if make the low fiber of Young's modulus, the state that the resin with high melting point of must directly take is fusing is set low-tension, can not be stable creating conditions under such condition.In addition, if directly take resin with high melting point is that the state of fusing carries out spinning reluctantly, be created in silk thread fracture of slightly small tension force in spinning, form the problem of the silk thread etc. of unstable rugosity, it is difficult stably carrying out spinning.In addition, when even the fiber that not at all easy use Young's modulus is low is manufactured nonwoven fabric, if carry out nonwoven fabric with existing condition, the less thick of nonwoven fabric, form the nonwoven fabric that liquid countercurrent is many, therefore, having physical property that Young's modulus is low is the existing concept of undesirable physical property for fiber.Its result is generally the fiber with 1.5～6.0GPa left and right Young's modulus.

But we are according to method described later, found the manufacture method of the fiber that Young's modulus is low and by its volume the earth nonwoven fabric, the method that effectively utilizes.

In the low composite fibre of Young's modulus, the degree of crystallinity of resin with high melting point of preferably bearing the most of intensity of fiber is low.According to the kind of resin with high melting point, the degree of crystallinity that realizes above-mentioned Young's modulus is naturally different, but while be acrylic resin (PP), preferred degree of crystallinity is below 60%, more preferably below 50%, be more preferably below 45%.

When the resin that forms core is polyethylene terephthalate (PET), preferably degree of crystallinity be below 45%, more preferably below 30%, be more preferably below 15%.

In addition, the resin preferred orientation coefficient of formation core is low.For example, during for acrylic resin, preferred orientation coefficient is below 60%, more preferably below 40%, be more preferably below 25%.During for pet resin (PET), orientation coefficient is preferably below 50%, more preferably below 20%, be more preferably below 10%.

The above-mentioned degree of crystallinity that forms the resin of core is obtained by following method.

[assay method of the degree of crystallinity of fiber]

Degree of crystallinity χ obtains from formula (1).

χ＝(1-(ρc-ρ)/(ρc-ρa))×100 (1)

Here, ρ c is the density of resin crystallization, is 0.936[g/cm in PP ³], be 1.457[g/cm in PET ³] (list of references 3).ρ a is the amorphous density of resin, is 0.850[g/cm in PP ³], be 1.335[g/cm in PET ³] (list of references 3).

In addition, (ρ c-ρ a) * (Lorentz density B-Lorentz density A)/(Lorentz density B-Lorentz density C) (2) for ρ=ρ c-

Here, Lorentz density A obtains from following formula (3).

Lorentz density A=(n ²-1)/(n ²+ 2) (3)

(3) n in formula is mean refractive index, uses the refractive index n of the parallel direction of said determination value _∥refractive index n with vertical direction _⊥, from formula (4), obtain.

n ²＝(n _∥ ²+2n _⊥ ²)/3 (4)

In addition, Lorentz density B can obtain the refractive index of different resins crystallization respectively as n substitution (3) formula, in PP resin, use n=1.52, uses n=1.64 (respectively with reference to list of references 2, list of references 1) in PET resin.In addition, Lorentz density C can obtain the amorphous refractive index of different resins respectively as n substitution (3) formula, in PP resin, use n=1.47, uses n=1.58 (respectively with reference to list of references 2, list of references 1) in PET resin.

[list of references 1] < < Eat and Port リ エ ス テ Le Trees fat Ha Application De Block Star Network > > (publishing house: daily magazine industry XinWen society, first edition, 1989)

[list of references 2] < < POLYMER HANDBOOK > > (A WILEY-INTERSCIENCE PUBLICATION, 1999)

In addition, degree of crystallinity is according to its assay method and condition, and the structure of regarding crystallization as is different, therefore, generally between different measuring methods, condition, cannot comment on its absolute value.

The above-mentioned orientation coefficient that forms the resin of core can be measured by following method.

[assay method of orientation coefficient]

Take the birefringence value of the resin in fiber as C, take the intrinsic birefringence value of resin during as D, orientation coefficient represents with following formula (5).

Orientation coefficient (%)=(C/D) * 100 (5)

The birefringence of the macromolecular chain that intrinsic birefringence refers to resin under state of orientation completely, its value is for example documented in < < shaping and processes To お け ゐ プ ラ ス チ Star Network material > > first edition, subordinate list: in the な プ ラ ス チ Star Network material that the processing To that is shaped represents with い ら れ ゐ (プ ラ ス チ Star Network shaping processing association Knitting, シ グ マ publish, and on February 10th, 1998 issues).

Birefringence in composite fibre, by Polarizer is installed in interference microscope, is measured under the polarisation with respect to fiber axis parallel direction and vertical direction.As maceration extract, the standard refraction liquid that uses Cargille company to produce.The refractive index of maceration extract is measured by Abbe refractometer.From utilizing the interference fringe of the composite fibre that interference microscope obtains, with the computational methods of recording, obtain the refractive index n with respect to the parallel direction of fiber axis in below with reference to document 3 _∥refractive index n with vertical direction _⊥, calculate the birefringence as both differences.

[list of references 3] < < プ ラ ス チ Star Network formed products high order Agencies makes and resolves into Door > > (editor (society) プ ラ ス チ Star Network is shaped and processes association, first edition, 2006)

The Thermoadhesive conjugate fiber that can preferably use as low Young's modulus fiber, for example, take vinyl (PE) and acrylic resin (PP) is raw material, manufacturing sheath portion while being PE, the core core-sheath-type composite fibre that is PP, can manufacture by suppressing the crystallization of the acrylic resin of core.

In addition, the Thermoadhesive conjugate fiber that can preferably use as low Young's modulus fiber, for example, take vinyl (PE) and pet resin (PET) is raw material, manufacturing sheath portion while being PE, the core core-sheath-type composite fibre that is PET, can manufacture by suppressing the crystallization of the pet resin of core.

The degree of crystallinity or the degree of orientation limit that for limit, suppress resin with high melting point maintain or improve the tension force in spinning, can relatively make solidifying with respect to resin with high melting point of low-melting-point resin accelerate, and make to bear tension force on sheath resin.Here, solidify the state that refers to that viscosity rises rapidly on spinning threadling.As its method, can enumerate by making the spinning temperature of resin with high melting point improve, improve spinning speed compared with the spinning temperature of low-melting-point resin and strengthen severing speed, thereby accelerate the crystallization speed of low-melting-point resin and accelerate curing method; When sheath portion is used low-melting-point resin, improve all spinning temperatures and make the first cooling method of sheath; In sheath resin, coordinate nucleator and promote method of crystallization etc.

The extrusion temperature of low-melting-point resin composition (spinning temperature) is preferably with respect to the temperature of high 80～250 ℃ of the fusing point of this resin, the more preferably temperature of high 130～170 ℃.

In addition, resin with high melting point preferably above with the temperature of the same degree of spinning temperature with low-melting-point resin, preferably with high 30 ℃ above, more preferably with high 50 ℃ of above temperature, carry out spinning.

As the nucleator that promotes sheath resin crystallization, can preferably use 1,3:2,4-dibenzylidene sorbitol, 1,3:2, Arrcostab (preferably carbon number is 8～22 Arrcostabs) the class nucleator of the aliphatic polyacid of the Arrcostab of the ester ring type polyacid of diacetyl compounds class nucleator, tetrahydrophthalic acid and the hexahydrophthalic acid etc. of 4-bis-(to methyl benzal) D-sorbite etc. (preferably carbon number is 8～22 Arrcostabs) class nucleator, adipic acid, decanedioic acid and azelaic acid etc., three (2-methylcyclohexyl acid amides) of tricarballylic acid etc.Add mineral-type pigment also to produce same effect.

Said method can be used separately any one, also can be used in combination a plurality of methods.In addition, can combine and spin a hauling speed higher than method of existing general speed etc.

In addition, the hauling speed that spins silk be preferably 500m/ minute above, more preferably 1000m/ minute above, be more preferably more than 1500m/ minute.

Device for spinning shown in Fig. 1 possesses extrusion device 1,2 and the spinneret 3 of two systems that comprise extruder 1A, 2A and gear pump 1B, 2B.Each resinous principle by extruder 1A, 2A and gear pump 1B, 2B melting and metering, at the interior interflow of spinneret 3, is discharged from nozzle.The shape of spinneret 3 is suitably selected according to the form of object composite fibre.In a preferred embodiment, to form resin that the resin of sheath portion surround to form core state around, from nozzle, discharge two kinds of resinous principles, such nozzle is formed with a plurality of with the state disperseing in border circular areas.Draw-gear 4 is set under spinneret 3, and the molten resin of discharging from nozzle draws downwards with the speed of regulation.In embodiment shown in Fig. 1, at suitable low Young's modulus fibre bundle of accommodating traction in accommodating part 6.

The low Young's modulus fiber of manufacturing by said method is crispaturaed and is processed and heat treated after spinning, and does not preferably carry out in fact stretch processing.That is, low Young's modulus fiber drawing of fiber not preferably.In addition, the processing example of crispaturaing, as implemented with apparatus for crimping (not shown), then, is processed (not shown) through super-dry, with shearing device (not shown), is cut to the length of regulation and forms staple fibre.

From making to form between fiber the viewpoint of the hot melt contact that thermal welding forms, the resinous principle that forms the sheath portion of the core-sheath-type composite fibre using as low Young's modulus is preferably polyvinyl resin.As polyvinyl resin, can use low density polyethylene (LDPE) (LDPE), high density polyethylene (HDPE) (HDPE), straight chain shape low density polyethylene (LDPE) (LLDPE) etc., but preferred density is 0.941g/cm ³above high density polyethylene (HDPE).As the polyvinyl resin in the application, except being separately the situation of polyvinyl resin, also comprise the situation of mixing other resin.As other resin mixing, can enumerate acrylic resin, ethylene-vinyl acetate copolymer (EVA), ETHYLENE-VINYL ALCOHOL COPOLYMER thing (EVOH) etc.Wherein, the resinous principle of formation sheath portion more than 50 quality % in the resinous principle of sheath portion is preferably polyvinyl resin, particularly preferably 70～100 quality % are polyvinyl resin.

The preferred example of the resinous principle of the core-sheath-type composite fibre core using as the low Young's modulus fiber of formation, can enumerate acrylic resin.The low resin of the preferred degree of crystallinity as above of acrylic resin, in addition, the resin that preferred orientation coefficient is low.Acrylic resin in this application, except being separately the situation of polyvinyl resin, also comprises the situation of mixing other resin.As other resin mixing, can enumerate polyvinyl resin etc.Wherein, 70 quality % in the resinous principle of the preferred core of resinous principle of formation core are acrylic resin above, particularly preferably 80～100 quality % are acrylic resin.

Other preferred example of the resinous principle of the core-sheath-type composite fibre core using as the low Young's modulus fiber of formation, can enumerate pet resin.The low resin of the preferred degree of crystallinity as above of pet resin, in addition, the resin that preferred orientation coefficient is low.Pet resin in the application, except being separately the situation of pet resin, also comprises the situation of mixing other resin.As other resin mixing, can enumerate polyvinyl resin etc.Wherein, 70 quality % in the resinous principle of the preferred core of resinous principle of formation core are pet resin above, particularly preferably 80～100 quality % are pet resin.

In addition, the preferred core of core-sheath-type composite fibre using as low Young's modulus fiber and the sectional area ratio (core: sheath) be 2: 8～8: 2, more preferably 4: 6～7: 3 of sheath portion.

In addition, the concrete purposes of the rugosity of low Young's modulus fiber (fiber number) basis such as nonwoven fabric etc. is selected suitable scope, but from really obtaining the reduction of Young's modulus and the viewpoint being told on by it, be preferably 1.0～10.0dtex, 2.0～8.0dtex more preferably.

Fig. 2 and Fig. 3 mean the figure of the 1st embodiment nonwoven fabric 10 of nonwoven fabric of the present invention.Nonwoven fabric 10 is examples of above-mentioned nonwoven fabric A.

The nonwoven fabric 10 of the 1st embodiment, for example, as shown in Figure 4, that to take the staple fibre of low Young's modulus fiber be raw material, use carding machine 11 to form after WEB 12, the heat embossing device 13 that these WEB 12 importings are possessed to pair of rolls 14,15 carries out embossing processing, then utilizes the hot blast treating apparatus 17 enforcement heat treatments of ventilating mode to obtain to the WEB 16 after ventilation processing.

In the pair of rolls of using in embossing processing, one is to be formed with the knurling rolls 14 of protuberance for the embossing of clathrate pattern at side face, another be have level and smooth side face, with the smooth roller 15 of this knurling rolls subtend configuration.Embossing processing is by carrying out WEB pressurization compression between the protuberance at knurling rolls 14 and the level and smooth side face of smooth roller 15.Thus, can obtain having the nonwoven fabric of the part 19 that the part (embossed portion) 18 of the thin thickness being processed to form by embossing and thickness are in addition thick.

Nonwoven fabric 10 forms the male and fomale(M&F) 10b with concaveconvex shape in one side, at another side, form smooth or less than the concavo-convex degree of above-mentioned male and fomale(M&F) tabular surface 10a.

The part 19 that thickness in nonwoven fabric 10 is thick and the part 18 of thin thickness form protuberance 119 and recess 118 in the male and fomale(M&F) 10b of nonwoven fabric 10.Recess 118 has be parallel to each other the 1st 118a of wire portion extending and the 2nd 118b of wire portion that is parallel to each other and extends, and the 1st 118a of wire portion and the 2nd 118b of wire portion form predetermined angular and intersect.Protuberance 119 is formed in the diamond shaped closed area of recess 118 encirclements.

(volume the earth is manufactured the method for the nonwoven fabric of low Young's modulus)

In current vent method, more than wind speed is generally 0.8m/sec, in order to make the nonwoven fabric volume of low Young's modulus large, wind speed particular importance, preferably with 0.1～0.8m/sec, more preferably the wind speed with 0.1～0.5m/sec carries out.By forming low wind speed, can because damaging, wind speed not form fusion point by nonwoven fabric.

From forming the viewpoint of the hot melt contact between fiber, more than the temperature that hot blast is processed is preferably the fusing point of resinous principle of the sheath portion that forms low Young's modulus fiber, particularly preferably with respect to the temperature of high 5～15 ℃ of this fusing point.

Fig. 5 means the figure of nonwoven fabric 10A of the 2nd embodiment of nonwoven fabric of the present invention.To the 2nd embodiment, do not have the aspect of special instruction identical with the nonwoven fabric 10 of the 1st embodiment.

The nonwoven fabric 10A of the 2nd embodiment obtains as follows: as nonwoven fabric manufacture, with fiber, commercially available Young's modulus is greater than in the WEB of 1.0GPa, Thermoadhesive conjugate fiber below 6.0GPa containing at present, the WEB of the staple fibre that lamination contains 100% low Young's modulus fiber, they are implemented to heat embossing processing integratedly, further implement to utilize the hot blast of ventilating mode to process.

The nonwoven fabric 10A of the 2nd embodiment comprises the 1st layer 100 of containing commercially available general fiber and the 2nd layer 101 of containing low Young's modulus fiber.The fiber that layers 1 and 2 preferably forms each layer has the hot melt contact between fiber, and in addition, preferably the formation fiber of the formation fiber of the 1st layer and the 2nd layer has the hot melt contact that thermal welding forms.When the face sheet using nonwoven fabric 10A as absorbent commodities such as menstrual hygiene towel is used, the 2nd layer 101 of containing low Young's modulus fiber used towards absorbing side.

As shown in Fig. 6 (a), by the face side that contains low Young's modulus fiber towards absorber 7 sides, as the face sheet of the absorbent commodities such as menstrual hygiene towel, use the 1st and when the nonwoven fabric 10 of the 2nd embodiment, 10A, face side towards user's skin one side is supplied with to the liquid 20 such as menses, nonwoven fabric is soaked (or impregnated) by liquid,, as shown in Fig. 6 (b), the surface tension effects of this liquid 20 is in the surface of non-woven skin contact surface side.Because surface tension inwardly acts at liquid surface, therefore, under this state, play a role and nonwoven thickness is reduced.Low Young's modulus fiber in this nonwoven fabric is easily out of shape, and is subject to thus this power, the less thick of the thickness of this nonwoven fabric, part 19 that particularly thickness except embossed portion is large.When an end face capillaceous is exerted pressure with certain size, the pressure acting on another end face in length capillaceous, be that the thickness of nonwoven fabric is more hour more close to original pressure (loss is few).According to this principle, by the less thick of nonwoven fabric, the power absorbing from the liquid of absorber less reduces the surface that acts on nonwoven fabric contact skin side, the effect efficiently in the integral body of nonwoven thickness direction or broad range that becomes of the strong capillary force of absorber.In addition, by fiber spacing, from narrowing down, the capillary force of nonwoven fabric itself also has the effect that becomes large.These results are as shown in Fig. 6 (c) and Fig. 6 (d), and liquid 20 sees through nonwoven fabric smoothly, are absorbed body 7 and absorb.These thickness and fiber spacing from minimizing be the temporary phenomenon of liquid while passing through.Along with liquid moves to absorber 20, owing to acting on the amount of liquid of nonwoven surface, tail off, the power that the surface tension of liquid applies nonwoven fabric reduces.Its result as shown in Fig. 6 (d), the caliper recovery of nonwoven fabric.Along with surperficial liquid disappears, thickness restores, therefore, residual liquid hardly in face material, thickness restores.After liquid, almost revert to original thickness.As a result, be difficult to occur the liquid countercurrent phenomenon (get damp) of liquid 20 from absorber adverse current to face sheet surface.

The rate of change of the drying regime of nonwoven fabric of the present invention and the nonwoven thickness of moisture state is preferably more than 15%, more preferably more than 20%, be more preferably more than 25%.The assay method of thickness and nonwoven thickness rate of change is narrated in an embodiment.

In addition, nonwoven fabric of the present invention from moisture state, be changed to drying regime again time nonwoven thickness recovery rate be preferably more than 70%, more preferably more than 80%, be more preferably more than 90%.The assay method of recovery rate is narrated in an embodiment.

In nonwoven fabric 110 as other embodiment of the present invention, as comprising fusing point mutually different the 1st composition and the composite fibre of the 2nd composition, contain the thermally extensible fiber that its length is extended because of heating, a face side, there is a plurality of protuberances 119 and recess 118, form this thermally extensible fiber of this protuberance 119 in their intersection point welding, the heat seal strength on the top of protuberance 119 is higher than the heat seal strength of bottom.

Nonwoven fabric 110 is aspect the form having as shown in Figures 2 and 3, identical with above-mentioned nonwoven fabric 10.Therefore, with reference to Fig. 2 form identical with nonwoven fabric 10 with Fig. 3 explanation.

Nonwoven fabric 110 forms single layer structure.Nonwoven fabric 110 is almost smooth in its one side (back side 10a in Fig. 3), and another side (the positive 10b in Fig. 3) forms the concaveconvex shape with a plurality of protuberances 119 and recess 118.That is, be the nonwoven fabric that is endowed three-dimensional shape.The formation fiber that recess 118 contains nonwoven fabric 110 is by densification, welding and the weld portion forming.As the formation method of weld portion, can enumerate and follow hot embossing processing etc.On the other hand, protuberance 119 forms non-weld portion.The thickness of recess 118 is less than the thickness of protuberance 119.Protuberance 119 forms the shape of swelling towards the face side (upper face side in Fig. 3) of nonwoven fabric 110.Formation fiber with nonwoven fabric 110 in protuberance 119 is full of.In protuberance 119, the formation fiber of nonwoven fabric 110 is in their intersection point welding.In protuberance 119, due to thermal welding between thermally extensible fiber, the fine hair in nonwoven fabric 110 surfaces is difficult to fluff.Between fiber, whether thermal welding is observed nonwoven fabric 110 by scanning electron microscope judges.

Recess 118 has the 1st 118a of wire portion extending to a direction in parallel to each other.In addition, recess 118 has the 2nd 118b of wire portion that the mode to intersect with the 1st wire portion is extended to a direction in parallel to each other.By two 118a of wire portion, 118b, intersect to form close-shaped rhombus part.This diamond-shaped portion is divided formation protuberance 119.That is, protuberance 119 is surrounded and is formed by continuous close-shaped recess 118.

As it, form fiber, the thermally extensible fiber that nonwoven fabric 110 contains the fiber extending because of heating as its length.As thermally extensible fiber, for example, can enumerate the fiber that the crystalline state of resin is extended because heating changes.Various thermally extensible fibers in nonwoven fabric 110 with the state that extended because of heating and/or can exist because of the state that heating is extended.That is,, in nonwoven fabric 110, contain the thermally extensible fiber of the state extending because of heating or contain and can or contain this two kinds of fibers because of the thermally extensible fiber of heating elongation state.Narrate in the back the details of thermally extensible fiber.

In each protuberance 119 of nonwoven fabric 110, form its thermally extensible fiber in their intersection point place welding.Nonwoven fabric 110 has one of feature in this heat seal strength.Specifically, heat seal strength is that protuberance 119 tops are higher than bottom.By the heat seal strength between the thermally extensible fiber in protuberance 119 is formed like this, if nonwoven fabric 110 is soaked by liquid, thickness reduces, the advantageous effects that realization can make this liquid effectively see through.Meanwhile, nonwoven fabric 110 realizations this liquid after liquid sees through is difficult to the advantageous effects at remained on surface.Its reason is because heat seal strength is different, the cause that deflection when nonwoven fabric 110 is soaked by liquid creates a difference.Limit is described in detail with reference to Fig. 6 (a)～Fig. 6 (d) limit.

As shown in Fig. 6 (a), by nonwoven fabric 110 using have in this nonwoven fabric 110 protuberance and recess the mode facing to user's skin when being disposed on absorber 7, using as the face sheet of the absorbent commodities such as menstrual hygiene towel, in the face side towards user's skin, the liquid such as menses 20 are drained, if nonwoven fabric 110 is soaked (or impregnated) by liquid 20,, as shown in Fig. 6 (b), the surface tension effects of liquid 20 is in the surface of the skin surface side of nonwoven fabric 110.Because the surface of surface tension at liquid 20 upcountry acts on, therefore, under this state, play a role and make to reduce nonwoven fabric 110 thickness.Now, and compare as the top at the high position of heat seal strength, in protuberance 119 as the bottom at the low position of heat seal strength due to easily distortion and be easily subject to the impact of this power of thermally extensible fiber.Its result, in protuberance 119, more to bottom, the deformation extent of thermally extensible fiber is larger, and fiber spacing uprises from shortening fibre density.That is, with absorb liquid 20 before compare, in protuberance 119, more to its underpart, fibre density is higher.

But, when an end face capillaceous is exerted pressure with certain size, the pressure acting on another end face in length capillaceous, be that the thickness of the nonwoven fabric 110 in Fig. 6 is more hour more close to original pressure (loss is few).According to this principle, by the less thick of nonwoven fabric 110, absorb the surface that the power from the liquid of absorber 7 less reduces the skin surface side that acts on nonwoven fabric 110, the effect efficiently in the integral body of the thickness direction of nonwoven fabric 110 or broad range of the strong capillary force of absorber 7.In addition, by fiber spacing, from narrowing down, also there are nonwoven fabric 110 capillary forces own to become large effect.These results are as shown in Fig. 6 (c) and Fig. 6 (d), and liquid 20 sees through nonwoven fabric 110 smoothly, are absorbed body 7 and absorb.

These thickness and fiber spacing from minimizing be liquid 20 by time temporary phenomenon.Along with liquid 20 moves to absorber 7, owing to acting on, the quantitative change of liquid 20 on nonwoven fabric 110 surfaces is few, and the surface tension effects of liquid 20 reduces in the power of nonwoven fabric 110.Its result is as shown in Fig. 6 (d), and the thickness of nonwoven fabric 110 restores.Along with liquid in nonwoven fabric 110 surfaces 20 disappears, the thickness of nonwoven fabric 110 restores, and therefore, almost there is no residual liquid 20 on nonwoven fabric 110, and its thickness restores.Nonwoven fabric 110 after liquid 20 passes through almost recovers original thickness.Its result, is difficult to produce liquid 20 from the contrary phenomenon of returning to nonwoven fabric 110 surfaces of absorber 7.

From making the more significant viewpoint of above-mentioned favourable effect, preferably the heat seal strength between the thermally extensible fiber in protuberance 119 from the top of protuberance 119 to bottom step-down slowly.For example, be preferably placed at heat seal strength between the thermally extensible fiber of corresponding position B of the protuberance in top P1, midriff P2, recess adjacent portion P3 and the back side 10a of the protuberance 119 shown in Fig. 3 from P1 to P3 gradually step-down, again from P3 to B step-down gradually.In order to control in this wise the heat seal strength between thermally extensible fiber, for example, can manufacture nonwoven fabric 110 according to manufacture method described later.

Heat seal strength between thermally extensible fiber in the protuberance 119 of nonwoven fabric 110 is measured with following method.Rosette (diameter 70mm, 300g) with polyurethane foam (the ウ レ タ Application Off オ mono-system モ Le ト Application MF30 that BRIDGESTONE (strain) produces, thickness 5mm) covering surfaces is installed on rotating shaft.It is position of rotation that disc centre departs from radius 20mm position from rotating shaft center be take in installation site.Below nonwoven fabric, lay polyurethane foam same as described above.Then, the mensuration face of nonwoven fabric is usingd flatly as fixing on platform above.On nonwoven fabric, carry above-mentioned disk.Now, the loading applying on nonwoven fabric is only the deadweight of disk.Under this state, make rotating shaft rotation, on nonwoven fabric, make disk circumference motion.Circular motion take turn clockwise 2 weeks, be rotated counterclockwise 2 weeks and carry out as 1 group.Circular motion speed is now that every motion 1 week was 3 seconds.Carry out after 10 groups of these circular motion, be collected in the fiber of extracting of the polyurethane foam surface attachment that covers disk, measure number of fiber.The number of fiber of extracting is more, represents that heat seal strength is lower.According to the method, using respectively the top P1 of protuberance and as the protuberance corresponding position B in the back side 10a of bottom with mensuration face (, positive 10b side and the rear side 10a of nonwoven fabric 110 of take is mensuration face), respectively the radical of extracting of protuberance upper and lower is measured.If the radical of extracting on protuberance top is that the radical of extracting of a, protuberance bottom is b, the gradient ratio of heat seal strength represents with calculating formula a/b.If this than being less than 1, represents that the heat seal strength on protuberance top is higher than the heat seal strength of protuberance bottom.

From further raising liquid permeability with further prevent the viewpoint of liquid countercurrent, the thermally extensible fiber preferred hydrophilic degree that forms protuberance 119 is that protuberance 119 tops are lower than bottom.By forming such hydrophilicity, form the gradient uprising to bottom hydrophilicity from protuberance 119 tops.This gradient forms driving force, and liquid is easily absorbed to bottom from the top of protuberance, and the permeability of liquid improves.Once liquid sees through, this gradient forms the barrier to liquid countercurrent, therefore, prevents that the effect of liquid countercurrent from becoming remarkable.For example, the hydrophilicity that is preferably placed at top P1, the midriff P2 of the protuberance 119 shown in Fig. 3, the protuberance corresponding position B in recess adjacent portion P3 and back side 10a uprises gradually, from P3, to B, uprises gradually from P1 to P3.In order to control in this wise hydrophilic degree, for example, when making hydrophilizing agent be attached to thermally extensible fiber, can manufacture nonwoven fabric 110 according to manufacture method described later.

Hydrophilizing agent adhere to by fiber surface, use the method for hydrophilizing agent and in the resin that forms fiber, sneak in advance hydrophilizing agent, the method for using this resin to carry out spinning realizes.Hydrophilizing agent is to make the hydrophily of fiber surface than making hydrophilizing agent adhere to the material of front raising.From improving hydrophilic viewpoint, with respect to the weight of thermally extensible fiber, the adhesion amount of hydrophilizing agent is preferably 0.1～0.6 % by weight, 0.2～0.5 % by weight more preferably.As hydrophilizing agent, can use the material identical with the hydrophilizing agent using in this technical field.As such hydrophilizing agent, various surfactants can be used as typical material and enumerate.

As surfactant, can use anion, CATION, amphion and non-ionic surfactant etc.As the example of anion surfactant, can enumerate alkylphosphonic, alkyl ether phosphate, Acidic phosphates salt, dialkyl sulfosuccinates, alkylbenzenesulfonate, alkylsulfonate, alkyl sulfate, secondary alkyl sulfate etc. (arbitrary alkyl all preferred carbon number is 6～22).As alkali metal salt, can enumerate sodium salt, sylvite etc.Example as cationic surfactant, can enumerate alkyl (or thiazolinyl) trimethyl-ammonium halide, dialkyl group (or thiazolinyl) dimethyl ammonium halide, alkyl (or thiazolinyl) halogenation pyridine etc., it is 6～18 alkyl or alkenyl that these compounds preferably have carbon number.As the halogen in above-mentioned halide, can enumerate chlorine, bromine etc.Example as zwitterionic surfactant, can enumerate alkyl (carbon number is 1～30) dimethyl betaine, alkyl (carbon number is 1～30) amido alkyl (carbon number is 1～4) dimethyl betaine, alkyl (carbon number is 1～30) dihydroxy alkyl (carbon number is 1～30) betaine, betaine type amphoteric ionic surface active agent and alanine type [alkyl (carbon number is 1～30) the aminopropan acid types such as sulfobetaines type amphoteric surfactant, alkyl (carbon number is 1～30) imino-diacetic propionic acid type etc.] zwitterionic surfactant, the amino acid type amphoteric ionic surface active agents such as glycine type [alkyl (carbon number is 1～30) amion acetic acid type etc.] zwitterionic surfactant, the sulfamic acid amphoteric ionic surface active agents such as alkyl (carbon number is 1～30) taurine type.Example as non-ionic surface active agent, can enumerate fatty acid glyceride, poly-(preferably n=2～10) fatty acid glyceride, the polyol fatty acid esters such as sorbitan fatty acid esters (all the carbon number of preferred fatty acid is 8～22), the oxyalkylene addition product of above-mentioned polyol fatty acid ester (preferably addition molal quantity is 2～20 moles), polyoxyalkylene (addition molal quantity is 2～20 moles) alkyl (carbon number is 8～22) acid amides, polyoxyalkylene (addition molal quantity is 2～20 moles) alkyl (carbon number is 8～22) ether, polyoxyalkylene modified polyorganosiloxane, amino modified polysiloxane etc.Special in for obtaining the combination of desired hydrophilic preferred surfactant or surfactant, can enumerate alkyl phosphoric acid sylvite, polyoxyethylene alkylamide and alkyl betaine, alkyl phosphoric acid sylvite and mersolates, polyoxyethylene alkyl amine and polyglycereol one alkylates, polyoxyethylene alkylamide and stearoyl phosphate kalium salt, polyoxyethylene alkylamide and polyglycereol one alkylates, mersolates and stearoyl phosphate kalium salt, alkyl ether potassium phosphate and polyglyceryl fatty acid ester, polyoxyethylene alkylamide and dialkyl sodium sulfosuccinate salt, polyoxyethylene polyoxypropylene modified polyorganosiloxane and dialkyl sodium sulfosuccinate salt, polyglyceryl fatty acid ester and dialkyl sodium sulfosuccinate salt, sorbitan fatty acid esters and dialkyl sodium sulfosuccinate salt, polyoxyethylene alkylamide and polyglyceryl fatty acid ester, polyoxyethylene alkylamide and sorbitan fatty acid esters, polyoxyethylene alkyl amine and sorbitan fatty acid esters, polyoxyethylene polyoxypropylene modified polyorganosiloxane and polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene modified polyorganosiloxane and polyglyceryl fatty acid ester, polyoxyethylene polyoxypropylene modified polyorganosiloxane and sorbitan fatty acid esters, sorbitan fatty acid esters and polyoxyethylene alkyl ether, polyglyceryl fatty acid ester and sorbitan fatty acid esters, polyglyceryl fatty acid ester and polyoxyethylene alkyl ether etc.As long as these preferred surfactants and preferred surfactant combination contain these surfactants, also can contain other surfactant etc.

Hydrophilic degree can be evaluated the contact angle of thermally extensible fiber by measuring water.Contact angle value is less, and to be evaluated as hydrophily higher.Contact angle is measured with following methods.As determinator, the automatic contact angle meter MCA-J that uses consonance interface science Co., Ltd. to produce.In contact angle determination, use distilled water.The liquid measure that to discharge from ink-jetting style water droplet discharge portion (CLUSTER TECHNOLOGY society produces, and discharge portion aperture is the pulse ejector filler CTC-25 of 25 μ m) is set as 20 skin liters, and water droplet drips directly over fiber.At the high speed recording apparatus being connected with horizontally disposed camera, record the state dripping.From after carry out the viewpoint that image is resolved, wish that recording apparatus is the personal computer that is assembled with high speed trap setting.In this mensuration, picture is recorded a video with every 17msec.In the image of recording, the initial image that water droplet is dripped on fiber be take attached software FAMAS, and (version of software is 2.6.2, analytic method is sessile drop method, analytic method is θ/2 method, image processing algorithm is areflexia, image processing image pattern is animation, and threshold level is 200, does not carry out radian correction.) carry out image and resolve, calculate face that water droplet contacts with air and the angle of fiber formation, as contact angle.In addition, test sample (taking out the fiber obtain from nonwoven fabric) is the fiber that is arranged in the top P1 of the protuberance shown in Fig. 3 from top layer with fibre length 1mm severing and is positioned at the protuberance corresponding position B of back side 10a, on the sample stage of contact angle meter, load this fiber, maintain level, 2 places different to this 1 fiber measure contact angle.In above-mentioned each position, with to following 1 contact angle that calculates N=5 root of decimal point, the average value of the measured value that adds up to 10 places (following the 2nd of decimal point rounds up) is defined as to contact angle separately.If the contact angle of protuberance top P1 is the contact angle of protuberance corresponding position B in α, back side 10a while being β, if the hydrophilic gradient representing with α/β ratio is greater than 1, represent that the hydrophily on protuberance top is lower than the hydrophily of protuberance bottom.

In protuberance 119, from further raising liquid permeability with further prevent the viewpoint of liquid countercurrent, preferably the fibre density on its top is lower than the fibre density of bottom.By form such gradient in fibre density, form the gradient uprising to bottom capillary force from the top of protuberance 119.This gradient forms driving force, and liquid is easily absorbed to bottom from the top of protuberance, and the permeability of liquid improves.Once liquid sees through, this capillary force gradient forms the barrier to liquid countercurrent, therefore, prevents that the effect of liquid countercurrent from becoming remarkable.For such capillary force gradient is set in nonwoven fabric 110, for example, can manufacture nonwoven fabric 110 according to manufacture method described later.

Fibre density is measured with following method.Cutting nonwoven fabric 110, makes its summit of containing protuberance, and the length parallel with MD direction (mechanical flow direction) is greater than 1mm and CD direction (with the direction of above-mentioned MD direction quadrature) width is 0.5～1.0mm.MD direction cross section with the nonwoven fabric of this cutting up loads on black platform, and (KEYENCE of Co., Ltd. produces, and VHX-900) obtains the cross section enlarged photograph along MD direction to use microscope.Use image analysis software (NexusNewQube) to carry out pattern dissection process to the data of this enlarged photograph (jpeg).Particularly, thickness direction carries out decile (protuberance upper side and protuberance lower side), MD direction is carried out binary conversion treatment to 1mm scope, and protuberance upper side and protuberance lower side are obtained to the spacial area occupation ratio of fiber (%).Fibre density X using this area occupation ratio separately as protuberance upper side, the fibre density Y of protuberance lower side, will using value that calculating formula Y/X calculates as fibre density gradient ratio.10 places by it to nonwoven fabric carry out, and try to achieve mean value.If this fibre density gradient ratio is greater than 1, represent that the fibre density on protuberance top is low, the fibre density of protuberance bottom is high.

Nonwoven fabric 110 is the nonwoven fabric that contain thermally extensible fiber.The thermally extensible fiber particularly preferably using is to comprise the 1st resinous principle that contains resin with high melting point and contain having fusing point or softening point is (following lower than the composite fibre of the 2nd resinous principle of the low-melting-point resin of the fusing point of the 1st resinous principle, this fiber is called to " thermally extensible composite fibre "), the 2nd resinous principle is along the length direction continued presence of at least a portion of fiber surface.The 1st resinous principle in thermally extensible composite fibre is that composition, the 2nd resinous principle of this fiber thermally extensible of expression is the composition of expressing this fiber thermal welding.Thermally extensible composite fibre is generally binary class, but can be also multicomponent classes more than three compositions.

Thermally extensible composite fibre can be because heat be extended in the temperature of the fusing point lower than the 1st resinous principle.Like this, thermally extensible composite fibre is than the temperature of high 10 ℃ of the 2nd resinous principle fusing point, while not having the resin of fusing point, the thermal stretching rate during in the temperature than high 10 ℃ of softening point is preferably 0.5～20%, is particularly preferably 3～20%, is especially preferably 5～20%.The nonwoven fabric 110 that contains such thermal stretching rate fiber is by the elongation of this fiber, and volume becomes large or presents three-dimensional outward appearance.For example, the concaveconvex shape on nonwoven fabric 110 surfaces becomes remarkable.

The fusing point of the 1st resinous principle and the 2nd resinous principle, (Seiko Instruments Co., Ltd. produces to use differential scanning type calorimeter, DSC6200), with 10 ℃/min of programming rate, carry out the heat analysis of the fiber sample (example weight 2mg) of very thin severing, measure the melting peak temperature of each resin.Fusing point is with this melting peak temperature definition.When the fusing point of the 2nd resinous principle can not clearly be measured with the method, this resin is defined as " resin that there is no fusing point ".Now, as the molecule of the 2nd resinous principle, start mobile temperature, using the temperature of the 2nd resinous principle welding when the degree of fusion point intensity that can instrumentation fiber as softening point.

[the thermal stretching rate of fiber]

The thermally extensible rate of fiber is measured with following methods.The thermo-mechanical analysis device TMA/SS6000 that uses Seiko Instruments (strain) to produce.As sample, the fibre length of preparing many collections is fiber more than 10mm, and the total weight that makes every fibre length 10mm is 0.5mg, and after this plurality of fibers is placed side by side abreast, the distance between chuck of take in device is 10mm installation.Making to measure initial temperature is 25 ℃, with certain load state of the 0.73mN/dtex that loads, with the programming rate intensification of 5 ℃/min.Measure elongate fiber amount now, the elongation Cmm while reading than the high 10 ℃ of temperature of the 2nd resinous principle fusing point (being softening point while there is no the resin of fusing point).The thermal stretching rate of fiber is from (C/10) * 100[%] calculate.Take above-mentioned temperature measuring thermal stretching rate reason as, as described later, while manufacturing nonwoven fabric 110 making the intersection point heat fusing of fiber, conventionally with the fusing point of the 2nd resinous principle or softening point is above and to manufacturing than the scope of these high 10 ℃ of left and right temperature.

While judging the thermally extensible of fiber from nonwoven fabric taking-up fiber, use following method.First, collect respectively the fiber at 5 each positions shown in the Fig. 3 that is positioned at nonwoven fabric.The fibre length of collecting is more than 1mm, below 5mm.The fiber of collection is sandwiched in to microscope with in sample, measures the fiber total length sandwiching.The microscope VHX-900, the camera lens VH-Z20R that use KEYENCE to produce, observe above-mentioned fiber with the multiplying power of 50～100 times, uses the instrumentation instrument that is assembled in device to look like to measure to this observation.The length that the said determination of usining obtains is as " the fiber total length of collecting from nonwoven fabric " Y.In the sample container (name of an article: robot container 52-023P, 15 μ L, aluminum) that the DSC6200 that SII NanoTechnology Co., Ltd. produces uses, put into the fiber of having measured total length.The container of putting into above-mentioned fiber is placed in to the sample mounting table being set in advance as than the heating furnace of the DSC6200 of the low 10 ℃ of temperature of the fusing point of the 1st resinous principle.With the temperature of the thermocouple measurement that arranges under the sample mounting table at DSC6200 (the expression title in instrumentation software: specimen temperature) reach than the fusing point of the 1st resinous principle low 10 ℃ ± temperature range of 1 ℃ after, heating 60sec, after this takes out rapidly.Fiber after heat treated is taken out from the sample container of DSC, be sandwiched in microscope with in sample, measure the fiber total length sandwiching.In mensuration, the microscope VHX-900, the camera lens VH-Z20R that use KEYENCE to produce, observe above-mentioned fiber with the multiplying power of 50～100 times, uses the instrumentation instrument that is assembled in device to look like to measure to this observation.The length that the said determination of usining obtains is as " the fiber total length after heat treated " Z.Thermal stretching rate (%) is from calculating with following formula.

÷ Y * the 100[% of thermal stretching rate (%)=(Z-Y)]

This value is defined as to the thermal stretching rate of the fiber taking out from nonwoven fabric.This thermal stretching rate is greater than at 0 o'clock, can judge that fiber is thermally extensible fiber.

Kind to the 1st resinous principle and the 2nd resinous principle is not particularly limited, so long as have the resin of fiber forming property power.Special in can easily carrying out the aspect of the manufacture of nonwoven fabric 110 by thermal welding, preferably the fusing point of two kinds of resinous principles the difference poor or fusing point of the 1st resinous principle and the softening point of the 2nd resinous principle be 20 ℃ above, be particularly preferably more than 25 ℃.When thermally extensible composite fibre is core-sheath-type, use the fusing point of core composition higher than the fusing point of sheath composition or the resin of softening point.Particularly preferably use and take the core-sheath-type thermally extensible composite fibre that polypropylene (PP) or polyethylene terephthalate (PET) be sheath as core, the fusing point of take lower than the resin of these fusing points.Preferred compositions as the 1st resinous principle and the 2nd resinous principle, as take 2nd resinous principle of the 1st resinous principle during as PP, can enumerate polyethylene, ethylene propylene copolymer, the polystyrene etc. such as high density polyethylene (HDPE) (HDPE), low density polyethylene (LDPE) (LDPE), straight chain shape low density polyethylene (LDPE) (LLDPE).In addition, while using the polyester resin of PET, polybutylene terephthalate (PBT) (PBT) etc. as the 1st resinous principle, as the 2nd resinous principle, except the example of above-mentioned the 2nd resinous principle, can enumerate PP, copolyester etc.In addition, as the 1st resinous principle, can also enumerate the copolymer of more than two kinds of polyamide polymers and above-mentioned the 1st resinous principle, in addition, as the 2nd resinous principle, also can enumerate the copolymer of more than two kinds of above-mentioned the 2nd resinous principle etc.They can be appropriately combined.

The fiber length of thermally extensible composite fibre can be used suitable length according to the manufacture method of nonwoven fabric 110.For example, while making nonwoven fabric 110 with comb and parallel cotton fibers prior to spinning legal system as described later, optimum fiber length is 30～70mm left and right.Then the fibre length of the thermal welding composite fibre of narration is also same.

The fibre diameter of thermally extensible composite fibre can suitably be selected according to the concrete purposes of nonwoven fabric 10.When the component parts of the absorbent commodities such as face sheet using nonwoven fabric 110 as absorbent commodity is used, preferably use 10～35 μ m, particularly preferably use the fibre diameter of 15～30 μ m.Then the fibre diameter of the thermal welding composite fibre of narration is also same.In addition, the fibre diameter of thermally extensible composite fibre is because elongation diminishes, and above-mentioned fibre diameter refers to the fibre diameter while using nonwoven fabric 110 in practice.

As thermally extensible fiber, for example, can use the fiber of recording in No. 4131852 communique of patent, JP 2005-350836 communique, JP 2007-303035 communique, JP 2007-204899 communique, JP 2007-204901 communique and JP 2007-204902 communique, JP 2008-101285 communique etc.

Nonwoven fabric 110 both can only consist of thermally extensible fiber, or also can contain other fiber beyond the thermally extensible fiber, for example, contain the core-sheath-type thermal welding composite fibre that 2 kinds of different compositions of fusing point and stretched processing form the non-thermally extensible that its length in fact do not extend because of heating and form.In addition, also can additionally contain the fiber (such as natural fabric, artificial silk and the acetate fiber etc. of cotton and paper pulp etc.) originally without thermal welding.When nonwoven fabric 110 also contains other fiber formation except thermally extensible fiber, the ratio of the thermally extensible fiber in this nonwoven fabric 110 be preferably 30 % by weight above, be particularly preferably 50 % by weight more than, the ratio of other fiber be preferably 70 % by weight following, be particularly preferably below 50 % by weight.

Then, limit is with reference to the applicable manufacture method of Fig. 7 limit explanation nonwoven fabric 110.Device 120 shown in Fig. 7 possesses WEB manufacturing department 130, embossing processing department 140, the attached portion 150 of blowing hot wind.In WEB manufacturing department 130, be used as the fiber (the thermally extensible composite fibre of state before extending) of the raw material of nonwoven fabric 110 to manufacture WEB 110a.WEB 110a has the 1st 1101 and is positioned at the 2nd 1102 with its opposition side.The 1st 1101 is the face with smooth roller 142 butts in embossing described later processing part 140, and in blowing hot wind described later portion 150, is and opposed of the conveyer belt 152 consisting of aeration WEB shape thing.The 2nd 1102 is the face with pattern roller 141 butts in embossing processing department 140, and in blowing hot wind portion 150, by the face of blowing hot-air.

As WEB manufacturing department 130, for example, can use carding machine 131 as shown in the figure.According to the concrete purposes of nonwoven fabric 110, also can use other WEB manufacturing installation, for example airflow net forming apparatus, replaces carding machine 131.The WEB 110a manufacturing by carding machine 131, it forms the state in loose complexing between fiber, does not obtain yet the shape stability as sheet.Therefore, in order to give the shape stability as sheet material to WEB 110a, in embossing processing department 140, this WEB 110a is processed, form embossing WEB 110b.

Embossing processing part 140 possesses the pair of rolls 141,142 of clamping WEB 110a and subtend configuration.Roller 141 forms by be formed with a plurality of concavo-convex metal pattern rollers at its side face.Relief pattern in this pattern roller can suitably be selected according to the concrete purposes of nonwoven fabric 110.For example, when forming the embossed pattern of the diamond check shape shown in Fig. 2, can on the side face of roller 141, form protuberance that should diamond check shape.In addition, while wishing to form the embossed pattern (not shown) of point-like on nonwoven fabric 110, can on the side face of roller 141, form putting the protuberance of shape.On the other hand, roller 142 consists of the level and smooth smooth roller of its periphery.Roller 142 is metal system, rubber system, made of paper etc.

In embossing processing department 140, with two rollers 141,142, clamp WEB 110a and carry out embossing processing.Particularly, by following hot densification, using the thermally extensible fiber densification of the formation fiber as WEB 110a, on this WEB 110a, form a plurality of embossed portion, manufacture embossing WEB 110b.In this manufacture method, roller 141 and roller 142 are the structures that can heat, and when 140 running of embossing processing department, at least pattern roller 141 is heated to set point of temperature.Smooth roller 142 both can be heated also and can not be heated.

In embossing processing department 140, heating as with WEB 110a face in the pattern roller 141 of roller of the 2nd 1102 butts, more than its temperature being remained on to the fusing point of the 2nd resinous principle in thermally extensible fiber.Meanwhile, using as with WEB 110a face in the temperature of smooth roller 142 of roller of the 1st 1101 butts remain the fusing point lower than the 2nd resinous principle in thermally extensible fiber.About smooth roller 142, both can with the state being heated, not use, its temperature is remained to the fusing point lower than the 2nd resinous principle, or also can be limited with the temperature not reaching more than the 2nd resinous principle fusing point, with the state being heated, use.By the temperature of such setting two rollers 141,142, can obtain reliably having given the embossing WEB 110b of shape stability.

From giving reliable shape stability, expressing high strength, in addition, from giving the viewpoint of soft skin feel, the fusing point of establishing the 2nd resinous principle be Mp (℃), more than the heating-up temperature of pattern roller 141 is preferably Mp, more preferably below above, the Mp+20 of Mp ℃.On the other hand, about smooth roller 142, preferably the temperature of smooth roller 142 is remained from normal temperature to Mp, more preferably remain below Mp-20 ℃ of above, Mp-5 ℃.By embossing processing department is set in to these temperature ranges, makes thermally extensible fiber not express essence and extend." essence is not expressed " is to get rid of to make consciously thermally extensible fiber extend, and is the meaning that allows inevitable thermally extensible fiber that temperature fluctuation in embossing processing department 140 etc. causes to extend a little.

The embossing WEB 110b that gives shape stability with the processing of embossing processing part 140 is then transported to blowing hot wind portion 150.When embossing WEB 110b is transported to blowing hot wind portion 150 from embossing processing department 140, preferably the speed increasing ratio of the peripheral speed v2 of the conveyer belt 152 of the blowing hot wind part 150 of the peripheral speed v1 of the pattern roller with respect in embossing processing part 140 and smooth roller ((v2-v1)/v1 * 100) inhibition is below 8%, is particularly preferably below 6%.In common embossing processing, because the heating-up temperature of each roller is relatively high, cause that thus embossing WEB 110b is easily attached at roller side face, be especially easily attached at smooth roller 142 sides.Now, must improve speed increasing ratio, forcibly embossing WEB 110b be peeled from roller side face.But, improve speed increasing ratio and be accompanied by embossing WEB 110b is applied to excessive pressure, therefore, its result produces and is difficult to make nonwoven fabric 110 volumes to become large improper.With respect to this, in this manufacture method, as mentioned above, because the heating-up temperature of roller is relatively low, special in the temperature of smooth roller 142 is low, therefore, even if reduce speed increasing ratio, embossing WEB 11b also easily peels from roller periphery.Its result, does not apply excessive pressure to embossing WEB 110b, can make nonwoven fabric 110 volumes become large.

Blowing hot wind portion 150 possesses cover 151.Embossing WEB 110b is by this cover 151.In addition, blowing hot wind portion 150 possesses the conveyer belt 152 consisting of aeration WEB.Conveyer belt 152 is in cover 151 interior rotations.Embossing WEB 110b loads on conveyer belt 152, is transported in blowing hot wind portion 150.Conveyer belt 152 is formed by resins such as metal and polyethylene terephthalate.

The structure of blowing hot wind portion 150 while representing to see from the carriage direction of embossing WEB 110b in Fig. 8.Conveyer belt 152 and mounting embossing WEB 110b thereon move with the direction of paper quadrature in Fig. 8.In cover 151, by dividing plate 153, be divided into the space of left and right.Space, left and right is communicated with in top and the bottom.In a space in space, left and right, conveyer belt 152 and embossing WEB 110b pass through.At the downside setting of the conveyer belt 152 tabular air cleaner 154 parallel with this conveyer belt 152.At embossing WEB 110b upside, air cleaner 154 is also set.Heat exchanger 155 and circulating fan 156 are set in another space.Heat exchanger 155 can be for the air in heating mantles 151.If make heat exchanger 155 runnings, circulating fan 156 runnings, the air covering in 151 is heated, and limit is by air cleaner 154, and the direction that edge represents with arrow in Fig. 8 circulates.Its result, 2nd 1102 side-blown of hot blast from the face of embossing WEB 110b sent.

By to embossing WEB 110b blowing hot-air, thermally extensible fiber is extended.Now, because the fiber that is arranged in embossing WEB 110b embossed portion is by densification, therefore, even if blowing hot-air does not extend yet.Elongation is being present in embossed portion thermally extensible fiber generation in addition.That is the part that, thermally extensible fiber extends is the part between embossed portion.Like this, a part for thermally extensible fiber is fixed by embossed portion, and the elongated portion of the thermally extensible fiber of elongation loses to the action place of the in-plane of embossing WEB 110b and moves to the thickness direction of this embossing WEB 110b.Thus, form protuberance 119 between embossed portion, it is large that embossing WEB 110b volume becomes.In addition, form and there is the three-dimensional outward appearance that is formed with a plurality of protuberances 119 formation.Like this, embossed portion forms recess 118.

In blowing hot wind, when thermally extensible fiber is extended, the intersection point between welding thermally extensible fiber.In this welding, be present in the closer to the fiber of the 2nd 1102 side positions as blowing hot wind face, the heat seal strength between thermally extensible fiber is higher.On the contrary, in the face of embossing WEB 110b, be present in the closer to the fiber of the position as opposed the 1st 1101 sides of conveyer belt 152, between thermally extensible fiber, the intensity of welding is lower.In order to realize this object, the surface temperature that preferably makes blowing hot-air position in conveyer belt 152 is below the fusing point of the 2nd resinous principle in thermally extensible fiber.Thus, the temperature of thermally extensible fiber that suppresses to be positioned at the 1st 1,101 one sides of embossing WEB 110b rises, and is difficult to cause the welding between thermally extensible fiber.

But, in conveyer belt 152, directly measure the surface temperature at blowing hot wind position and see technically it is very difficult.Therefore, in this manufacture method, index instead, measures the surface temperature (mensuration of this surface temperature is easy) of the conveyer belt 152 after blowing hot wind has just finished, the surface temperature of controlling conveyer belt 152, making this temperature is below the 2nd resinous principle fusing point in thermally extensible fiber.Particularly, in Fig. 7, at conveyer belt 152, from cover 151 positions out, measure the surface temperature of conveyer belt 152.If this is that the surface temperature due to the conveyer belt 152 in this position is below the fusing point of the 2nd resinous principle, can reasonably think that the surface temperature of conveyer belt 152 at position (covering in 151) of blowing hot-air is also below the fusing point of the 2nd resinous principle.

If take the 2nd resinous principle fusing point as Mp (℃), the surface temperature of the conveyer belt 152 of blowing hot wind after just having finished be preferably Mp-20 ℃ above, below Mp, more preferably Mp-10 ℃ above, below Mp.The surface temperature of conveyer belt 152 is measured by for example contact tehermometer ANRITSU DIGITAL THERMOMETER LC-1 SENSER 221K (translational surface is used).

In order to make the surface temperature of conveyer belt 152 become above-mentioned scope, for example, can be set forth in front cooling this conveyer belt 152 of the attached hot blast of conveyer belt 152 blowing up, the surface temperature that makes this conveyer belt 152 is the method below the 2nd resinous principle fusing point.For cooling, for example can at this conveyer belt 152, face in the position before entering in cover 151 as shown in Figure 7, on this conveyer belt 152, make chill roll 157 butts.Chill roll 157 portion's circulation within it cooling fluid, is set as lower than environment temperature.Therefore, by chill roll 157, be connected to conveyer belt 152, cooling this conveyer belt 152, enters in cover 151 with the state of surface temperature step-down.In conveyer belt 152 cooling, can replace chill roll 157 or adopt in addition coldblast etc.

Higher in order to make to be present in the closer to heat seal strength between the fiber thermally extensible fiber of the position of the 2nd 1102 sides as blowing hot wind face, making hot blast is that low wind speed is also effective.From this viewpoint, the pressure reduction with the position (position representing with A in Fig. 8) of conveyer belt 152 top 10cm and the position (position representing with B in Fig. 8) of bottom 10cm be preferably 0.4～5Pa, be particularly preferably 0.4～3.5Pa wind speed blow attached hot blast.Here so-called wind speed refers in practice to the 2nd 1the fiber of 102 sides blows, at the 1st 1101 sides are by the wind speed of leaving away.Preferred wind speed is the ultra micro wind that is less than 0.4m/sec, and it is difficult with airspeedometer, directly calculating this wind speed of mensuration.Therefore, use above-mentioned pressure reduction to represent and replace instrumentation, stipulate this ultra micro wind.In addition, the pressure representative negative pressure of the position representing with A, the negative pressure that the pressure representative of the position representing with B is larger than A position.In addition, in principle, should be the pressure of measuring the extremely near position of embossing WEB 110b, obtain pressure reduction.But, in reality, such be determined at technical to be very difficult, therefore, in this manufacture method, to be the pressure of measuring in the position of leaving up and down 10cm.

The hot blast temperature blowing is temperature more than the 2nd resinous principle fusing point in thermally extensible fiber.Here so-called temperature is the hot blast temperature in embossing WEB 110b surface.But, in reality, because the hot blast temperature in this position is determined at technical, be very difficult, therefore, in this manufacture method, mensuration is from leaving the hot blast temperature of 10cm position on embossing WEB 110b, if this temperature is the temperature more than fusing point of the 2nd resinous principle, it is the temperature more than fusing point of the 2nd resinous principle that the hot blast temperature in embossing WEB 110b surface is also considered as.

If take the 2nd resinous principle fusing point as Mp (℃), on embossing WEB 110b, leave hot blast temperature 10cm position be preferably Mp more than, below Mp+50 ℃, more preferably below above, the Mp+30 of Mp ℃.Hot blast temperature for example passes through thermocouple measurement.

Take hot blast temperature and pressure reduction is condition in above-mentioned scope inside, and the time of blowing hot wind is preferably 1～20 second, is particularly preferably 3～15 seconds.

By adopting the above-mentioned condition that respectively blows, be present in the closer to the fiber of the 2nd 1102 sides, between thermally extensible fiber, the intensity of welding becomes higher.In addition, be present in the closer to the fiber of the 2nd 1102 sides, the elongation degree of thermally extensible fiber becomes larger.That is, be present in the closer to the fiber of the 2nd 1102 sides, fiber spacing is from becoming larger.Say on the contrary, be present in the closer to the fiber of the 1st 1101 sides, fiber spacing is from becoming less.Its result, in the protuberance 119 in the nonwoven fabric 110 obtaining, from its underpart to top, fibre density is step-down slowly.

The embossing WEB 110b that contains the thermally extensible fiber that is attached with in advance hydrophilizing agent is carried out to blowing hot wind, and when this thermally extensible fiber is extended, the result judgement of the present inventor's research obtains, and extends larger position hydrophily and more declines.Therefore, in this manufacture method, be positioned at the thermally extensible fiber that more leans on the 2nd 1102 sides of blowing hot wind face, the degree of elongation becomes larger, and hydrophilic decline becomes larger.Because the face of blowing hot wind is to be formed with protuberance 119 in nonwoven fabric 110 and the face of recess 118, therefore for the nonwoven fabric 110 obtaining, more, to the top of protuberance 119, it is larger that hydrophilic decline just becomes.Say on the contrary, more, to the bottom of protuberance 119, it is higher that hydrophily just becomes.Therefore, in protuberance 119, the back side 10a side from its top P1 to nonwoven fabric 110, in Fig. 3 from P1 to P3 and from P3 to B, the hydrophily of this thermally extensible fiber uprises gradually.

In blowing hot wind in this manufacture method, of course not all thermally extensible fibers all thoroughly extend completely.Therefore, nonwoven fabric 110 is to take thermally extensible fiber as nonwoven fabric raw material manufacture and that contain thermally extensible fiber.

The nonwoven fabric A that the present invention is relevant can apply in a flexible way and reduce the interfibrous distance of low Young's modulus when imbibition and improve logical fluidity and by the characteristic of removing caliper recovery after liquid etc. that has that hot melt contact produces, in various fields, use.

In addition, above-mentioned nonwoven fabric 110 can be applied in a flexible way and when imbibition, be reduced interfibrous distance and prevent that the effect of liquid countercurrent from uprising the characteristic waiting while improving dry after logical fluidity and imbibition, in the use of various fields.

For example, the various parts that can be used as in menstrual hygiene towel, absorbent commodity (particularly disposable hygienic article) that for women, panty liner, disposable diaper, incontinence pad etc. are used from the liquid absorption that health is discharged are used.As such parts, for example, can enumerate face sheet, secondary sheet material (being disposed at the sheet between face sheet and absorber), back-sheet, leakproof sheet material etc.In addition, nonwoven fabric also can be used as people is used with sheet material well with cleaning wipe sheet, skin care.Can also be as uses well such as the wipe sheet that thing is used.The face sheet that particularly nonwoven fabric can be used as the absorbent commodity using from the liquid absorption that health is discharged is used well.

The weight per unit area of nonwoven fabric is suitably selected according to the concrete purposes of the nonwoven fabric as object.The weight per unit area of the nonwoven fabric while using as the face sheet of absorbent commodity is preferably 10～80g/m ², be particularly preferably 15～60g/m ².

Nonwoven fabric 10,10A, 110 are when for example the face sheet using it as absorbent commodity is used, and the thickness of drying regime is preferably 0.5～3mm, is particularly preferably 0.7～3mm.

Recess 118 in nonwoven fabric 10,10A, 110 and the Area Ratio of protuberance 119 represent with embossing rate (embossing area occupation ratio, with respect to the total ratio of recess 118 areas of nonwoven fabric integral body), volume size and the intensity of nonwoven fabric are exerted an influence.From these viewpoints, the embossing rate in nonwoven fabric is preferably 5～35%, is particularly preferably 10～25%.Above-mentioned embossing rate is measured by following method.First, (KEYENCE of Co., Ltd. produces to use microscope, VHX-900), obtain the surperficial enlarged photograph of nonwoven fabric, this nonwoven surface enlarged photograph is measured to the size of recess 118 (being embossed portion) according to scale, calculated the area aggregate value P of the recess 118 in the entire area Q that measures position.Embossing rate can be calculated by calculating formula (P/Q) * 100.

For the absorbent commodity of the liquid absorption of discharging from health, typical case, possesses face sheet, back-sheet and is disposed at the absorber of the liquid retainability between two sheet materials.As usining the absorber of the relevant nonwoven fabric of the present invention while using as face sheet and as back-sheet, can use without particular limitation normally used material in this technical field.

For example, as absorber, can use with the coated fiber assembly being formed by fibrous materials such as paper pulp fibers of the cladded sheet materials such as toilet paper or nonwoven fabric or keep therein the aggregate of absorbable polymer and the absorber that forms.As back-sheet, can use liquid impermeability or the hydrophobic sheet material of the film of thermoplastic resin and the laminated sheet of this film and nonwoven fabric etc.Back-sheet also can have steam breathability.Absorbent commodity can also possess the various parts corresponding to the concrete purposes of this absorbent commodity.Such parts are known to this field practitioner.For example, in disposable diaper and sanitary napkin, be suitable for while using absorbent commodity, can the left and right sides portion on face sheet configure a pair of or more than two pairs stereoscopic protective.

Above, based on the preferred embodiment of the present invention, the present invention has been described, but the present invention is not limited by above-mentioned embodiment.

For example, exemplified with usining the fiber of Young's modulus 0.2～1.0GPa as the example that forms fiber and contain, but replace, also can use sheath portion resin is the fiber of the elastic resins such as elastomer.In addition, also can use the nonwoven fabric of molten melting point depression.

In addition, for example, in Fig. 4, as the manufacture method of nonwoven fabric, exemplified with implement heat treated example after embossing processing, but replace, also can after hot blast is processed, implement embossing processing.In addition, the embossed portion when nonwoven fabric forms embossed portion forms pattern, can replace clathrate and is made for the arbitrary graphic patterns such as striated, point-like, chessboard trellis, helical form of multiple row.Each point shape when being made for point-like, can be made for the shape arbitrarily such as circle, ellipse, triangle, quadrangle, hexagon, heart type.In addition, also can adopt the clathrate and the shape that is made for tortoise plastron apperance of square or rectangular.

In addition, embossing processing also can replace heat embossing and use ultrasonic wave embossed, high-frequency embossing, only compression and the embossing etc. that do not produce heat fusing.

In addition, according to the present invention, also can provide contain comprise fusing point mutually different the 1st and the 2nd composition, Young's moduluss be the nonwoven fabric (thickness change does not limit) that intersection point between 0.2～1.0GPa composite fibre, this composite fibre is formed with the hot melt contact of a plurality of heat fusings, wherein its 1st composition contains acrylic resin or polyethylene terephthalate, and the 2nd composition contains fusing point lower than the resin of the 1st congruent melting point.

In addition, in the manufacture method of the nonwoven fabric shown in Fig. 7, in embossing processing part 140, allocation plan table roll 141, make the 1st 1101 butts of itself and WEB 110a, and configure smooth roller 142, make itself and the 2nd 1102 butts, but replace, also can configure smooth roller 142, make the 1st 1101 butts of itself and WEB 110a, and allocation plan table roll 141, make itself and the 2nd 1102 butts.Now, smooth roller is remained to the fusing point of the low-melting-point resin in thermally extensible fiber above and pattern roller is remained to the fusing point lower than the low-melting-point resin in thermally extensible fiber.

In addition, nonwoven fabric of the present invention can be both single layer structure, can be also two layers of above sandwich construction.

Embodiment

Below, utilize embodiment to illustrate in greater detail the present invention.But scope of the present invention is not limited by such embodiment.

[embodiment 1]

The manufacture of (1) the 1st layer

At core with using polypropylene in resin, in sheath portion with using polyethylene in resin, with 325 ℃ of core melt temperatures, 280 ℃, sheath portion, utilize melt spinning method, with spinning speed 1500m, manufacture fiber number is the concentric core-sheath-type composite fibre that 3.5dtex, Young's modulus are 0.58GPa.The processing of crispaturaing, but do not carry out especially stretch processing.After crispaturaing, carry out high temperature drying, cut off the fiber obtain and obtain the staple fibre that fibre length is 51mm.The staple fibre that use obtains, utilizes carding machine to form weight per unit area 20g/m ²wEB.

The manufacture of (2) the 2nd layers

The core-sheath-type composite fibre that use is used in the 1st layer, operates equally with the WEB of the 1st layer of use, manufactures the WEB of the 2nd layer of use.

(3) nonwoven fabricization processing

2 kinds of WEB that lamination is manufactured as aforesaid operations, implement ultrasonic wave embossed processing integratedly to this laminated body.Embossing processing is implemented in the mode of knurling rolls and the 1st layer of side butt, smooth roller and the 2nd layer of side butt, embossed pattern is continuous repetition rhombus (inclination grid), the long-diagonal of this non-embossed portion is mechanical flow direction, short diagonal is perpendicular to above-mentioned flow direction, catercorner length is respectively 13mm, 8mm, embossed portion is wire, uses 0.5mm width.

Then, to the processing of ventilating of the laminated body after embossing processing.The heat treatment temperature of ventilation processing is 136 ℃.The wind speed of hot blast is 0.4m/sec, and the processing time is 4sec.

The nonwoven fabric obtaining has part (embossed portion) and the thick part of thickness in addition of thin thickness.In addition, weight per unit area is 40g/m ².

[embodiment 2]

Similarly to Example 1 at core with using polypropylene in resin, in sheath portion with using polyethylene in resin, in the WEB manufacture of using in layers 1 and 2, using and utilizing fiber number that melt spinning method obtains is that 3.5dtex, Young's modulus are 0.64GPa, the fibre length concentric core-sheath-type composite fibre that is 51mm, operation similarly to Example 1, manufactures nonwoven fabric.

[embodiment 3]

At core with using polyethylene terephthalate in resin, in sheath portion with using polyethylene in resin, in the WEB manufacture of layers 1 and 2, use utilizes the concentric core-sheath-type composite fibre that the fiber number that melt spinning method obtains is 45mm for 4.3dtex, Young's modulus for 0.68GPa, fibre length, in addition, operation similarly to Example 1, manufactures nonwoven fabric.

[embodiment 4]

Use core, for polyethylene terephthalate, sheath portion are poly commercially available core-sheath-type composite fibre, utilizes comb and parallel cotton fibers prior to spinning legal system to make weight per unit area for 20g/m ²wEB.

WEB using the WEB of manufacturing as the 2nd layer of use is used, and makes to add up to 40g/m ², and by WEB, use as the 1st layer with the 1st layer of WEB of manufacturing with the same operation of WEB of embodiment 1, in addition, operation similarly to Example 1, manufactures nonwoven fabric.

[embodiment 5]

Overlapping 2 pieces with the 1st layer of embodiment 1 WEB of manufacturing with the same operation of WEB, then, after laminated body ventilate and processed, implement ultrasonic wave embossed processing.The heat treatment temperature of ventilation processing is 136 ℃.Embossing processing is implemented in the mode of knurling rolls and the 1st layer of side butt, smooth roller and the 2nd layer of side butt, embossed pattern is continuous repetition rhombus (inclination grid), the long-diagonal of this non-embossed portion is mechanical flow direction, short diagonal is perpendicular to above-mentioned flow direction, catercorner length is respectively 13mm, 8mm, embossed portion is wire, uses 0.5mm width.

[comparative example 1,2,3]

Except as using the WEB shown in table 1 in the WEB of the 1st layer of use and the WEB of the 2nd layer of use, operate similarly to Example 1 and manufacture nonwoven fabric.The WEB of the WEB of the 1st layer of use and the 2nd layer of use contains poly core-sheath-type composite fibre by the commercially available known portion of sheath arbitrarily making generally to create conditions and forms.

[evaluation]

Thickness when each nonwoven fabric obtaining in embodiment and comparative example is determined to drying regime and moisture state and fiber spacing from.In addition, measure liquid residue and return liquid measure.In table 1, represent these results.

[table 1]

Thickness and fiber spacing from assay method and liquid residue, return liquid measure assay method as follows.

[thickness and fiber spacing from assay method]

[thickness of drying regime and fiber spacing from]

From commercially available menstrual hygiene towel, (Kao Corp produces, trade name " ロ リ エ さ ら さ ら Network Star シ ヨ Application flesh キ レ イ absorbs plumage つ I ") take off after face sheet, absorber is cut to length direction 50mm * width (direction vertical with the length direction of sanitary napkin) 50mm of sanitary napkin, obtains sanitary napkin absorber (using the absorber of sanitary napkin middle body).The nonwoven fabric of determination object is cut to length direction 50mm * width 50mm of sanitary napkin, makes the cut off machine of this nonwoven fabric.On above-mentioned sanitary napkin absorber, load this cut off machine, make the menstrual hygiene towel using determination object nonwoven fabric as face sheet.

Above-mentioned nonwoven thickness is under the state loading on above-mentioned sanitary napkin absorber, with the mensuration of not pressurizeing.Measuring environment is 20 ± 2 ℃ of temperature, relative humidity 65 ± 5%, and (KEYENCE of Co., Ltd. produces, VHX-900) in measuring machine, to use microscope.First, obtain the enlarged photograph in above-mentioned nonwoven fabric cross section.In enlarged photograph, take the object into known dimensions simultaneously.The enlarged photograph in above-mentioned nonwoven fabric cross section is measured to the thickness of nonwoven fabric according to scale.Carry out 3 above operations, the nonwoven thickness [mm] that the mean value of 3 times of take is drying regime.

The fiber spacing of the fiber of formation determination object nonwoven fabric is from trying to achieve by the formula of supposition shown below, based on Wrotnowski.The formula of the supposition based on Wrotnowski generally the fiber spacing of obtaining the fiber that forms nonwoven fabric from time use.According to the formula of the supposition based on Wrotnowski, fiber spacing passes through nonwoven thickness h (mm), weight per unit area e (g/m from A (μ m) ²), form fibre diameter d (μ m), the fibre density ρ (g/cm of the fiber of nonwoven fabric ³), with following formula (6), try to achieve.

[thickness of moisture state and fiber spacing from]

Except determination object thing is the nonwoven fabric of (moisture state) while soaking in liquid, with the same operation of nonwoven thickness evaluation of drying regime and evaluate.In addition, the nonwoven thickness while soaking in liquid, from the disposable dropping 3.0g defiber horse blood in top (the 1st layer of side) of the nonwoven fabric of determination object, measures and flows into the nonwoven thickness after 60 seconds after above-mentioned horse blood.Carry out 3 above operations, using the mean value of 3 times as the nonwoven thickness (mm) of moisture state.

Fiber spacing from (μ m) can with use fiber spacing for calculating drying regime nonwoven fabric from above-mentioned formula similarly obtain.

[thickness while being changed to drying regime again from moisture state and fiber spacing from]

Thickness while being changed to drying regime again from moisture state, on determination object thing, drip liquid after after 3 minutes, the thickness of the thickness of the mensuration of usining from above-mentioned moisture state 2 minutes when being changed to drying regime again from moisture state.

Nonwoven fabric after determination object thing is dropping liquid after 3 minutes, operate equally and evaluate with the nonwoven thickness evaluation of drying regime.In addition, the thickness while being changed to drying regime, from the disposable dropping 3.0g defiber horse blood in top (the 1st layer of side) of the nonwoven fabric of determination object, measures and flows into the nonwoven thickness after 3 minutes after above-mentioned horse blood.Carry out 3 above operations, using the mean value of the 3 times nonwoven thickness [mm] when being changed to drying regime again from moisture state.

Fiber spacing from (μ m) can with use fiber spacing for calculating drying regime nonwoven fabric from above-mentioned formula similarly obtain.

[rate of change of nonwoven thickness]

That use is measured with said method, the thickness A (mm) of drying regime and the thickness B (mm) of moisture state, the thickness change (rate of change of nonwoven thickness) while being changed to moisture state with following formula calculating from drying regime.

The rate of change of nonwoven thickness (%)=[(A-B)/A] * 100 (7)

This value is more than 15%, be in particular 20% when above, can obtain good result.

[recovery rate of nonwoven thickness]

That use is measured with said method, the thickness A (mm) of drying regime, the thickness B (mm) of moisture state and the thickness C (mm) while being changed to drying regime again from moisture state, calculate the caliper recovery rate (recovery rate of nonwoven thickness) while being changed to drying regime again from moisture state with following formula.

The recovery rate of nonwoven thickness (%)=(C/A) * 100 (8)

This recovery rate is preferably more than 70%, more preferably more than 80%, be more preferably more than 90%.

Above-mentioned thickness change is more than 15% and above-mentioned recovery rate is more than 70%, liquid mobile in absorber etc. after, can reduce the liquid residue in nonwoven fabric, can more effectively prevent that the liquid of this absorber etc. from turning back in nonwoven fabric and the liquid countercurrent of nonwoven surface.

[mensuration of liquid residue (method 1)]

From commercially available menstrual hygiene towel (Kao Corp produces, trade name " ロ リ エ (registration mark) さ ら さ ら Network Star シ ヨ Application flesh キ レ イ absorbs plumage つ I "), take off face sheet, obtain towel absorber.In addition, the nonwoven fabric of determination object is cut to MD50mm * CD50mm, makes cut off machine.Above-mentioned surface patch existence place in above-mentioned sanitary napkin absorber (on sanitary napkin absorber skin contact), configures this cut off machine by the 2nd layer of side towards absorbing side, makes the menstrual hygiene towel using the nonwoven fabric of determination object as face sheet.

State in the use on the surface of menstrual hygiene towel of nonwoven fabric of determination object, the overlapping cylindric propylene substrate that sees through hole with diameter 10mm, applies certain loading of 100Pa to this sanitary napkin.Under such loading, from this propylene substrate, see through hole and flow into 3.0g defiber horse blood.After flowing into above-mentioned horse blood, after 60 seconds, take off propylene substrate, then, measure the weight (W2) of this nonwoven fabric, calculate with the inflow horse blood of measuring in advance before poor (W2-W1) of nonwoven fabric weight (W1).Carry out 3 above operations, the mean value of 3 times of take is liquid residue (mg), and liquid residue is evaluated higher more at least.

[returning the mensuration (method 1) of liquid measure]

Operate equally with the assay method of above-mentioned [returning liquid measure], the nonwoven fabric of determination object is cut to MD150mm * CD50mm, obtain the menstrual hygiene towel using this nonwoven fabric as surface patch.

On the surface of the above-mentioned nonwoven fabric (face sheet) in above-mentioned menstrual hygiene towel, overlapping have a cylindric propylene substrate that sees through hole, and this sanitary napkin is applied to 1.1g/cm ²loading.Under such loading, from this propylene substrate, see through hole and flow into 3.0g defiber horse blood.After flowing into above-mentioned horse blood, after 60 seconds, take off propylene substrate, then, overlapping toilet paper in above-mentioned nonwoven surface, then on this cotton paper overlapping scheelite, this sanitary napkin is applied to the loading of 400Pa.At overlapping scheelite, after 5 seconds, take off this scheelite and toilet paper, measure the weight (W2) of this toilet paper, poor (W2-W1) of the toilet paper weight (W1) before that calculate and measure in advance, overlapping in above-mentioned nonwoven surface.Carry out 3 above operations, with the mean values of 3 times, for returning liquid measure (mg), return liquid measure and evaluate more at least higher.

[embodiment 6～10 and comparative example 4 and 5]

Use is in the single-layer nonwoven 110 of form shown in the device shown in Fig. 7 and Fig. 8, shop drawings 2 and Fig. 3.Pattern roller 141 in device shown in Fig. 7 is to have the roller that live width is the diamond check shape protuberance of 0.5mm.Protuberance area occupation ratio in this pattern roller 141 is 14%.As thermally extensible composite fibre, using core to contain the fiber number that polypropylene (161 ℃ of fusing points), sheath contain polyethylene (126 ℃ of fusing points) is the stable fibers that 4.2dtex, thermal stretching rate are 8%.With the condition manufacture shown in following table 2, obtain nonwoven fabric.In the nonwoven fabric obtaining in each embodiment, the intersection point welding between thermally extensible composite fibre.In addition, to the fiber containing in the nonwoven fabric obtaining in each embodiment, with the method judgement of previously having narrated, have or not thermally extensible, confirm to have thermally extensible.The weight per unit area of the nonwoven fabric obtaining in embodiment and comparative example represents in same table.To the nonwoven fabric obtaining in embodiment and comparative example, with said method, measure every physical property.In addition, with following methods, carry out various evaluations.In table 2, represent these results.

[feel: the harsh feeling that there is no nonwoven surface]

The mode making progress with protuberance on platform is placed nonwoven fabric.10 syndics of take are object, with the following judgment standard of 3 grades, evaluate the sense of touch on palm.Result represents with 10 people's mean value.

Judgment standard

3: clearly without harsh feeling

2: harsh feeling slightly

1: have harsh feeling

Evaluation result

Zero: judgement mean value is more than 2.5, below 3

△: judgement mean value is more than 1.5, is less than 2.5

*: judgement mean value is more than 1, is less than 1.5

[mensuration of liquid residue (method 2)]

The nonwoven fabric of determination object is cut to MD120mm * CD60mm, in addition, after flowing into 3.0g defiber horse blood, after 120 seconds, flow into again 3.0g defiber horse blood, after adding up to inflow 6.0g horse blood, after 60 seconds, take off propylene substrate, in addition, operate equally with above-mentioned [mensuration of liquid residue (method 1)], measure liquid residue.

[returning the mensuration (method 2) of liquid measure]

The nonwoven fabric of determination object is cut to MD120mm * CD60mm, in addition, after flowing into 3.0g defiber horse blood, after 60 seconds, flow into again 3.0g defiber horse blood, after adding up to inflow 6.0g horse blood, after 60 seconds, take off propylene substrate, in addition, operate equally with above-mentioned [returning the mensuration (method 1) of liquid measure], measure and return liquid measure.

[table 2]

^*1: face enter conveyer belt before and from cover, blow immediately air out

From the result shown in table 1, be judged as that nonwoven fabric (product of the present invention) liquid residue obtaining the nonwoven fabric 1～5 of embodiment is few and to return liquid measure few, absorbency, prevent aspect liquid countercurrent excellent.

Knownly, the nonwoven fabric obtaining in embodiment 6～10 (product of the present invention), is judged as that liquid residue is few, liquid permeability is high to result as shown in from table 2.In addition, be judged as and prevent liquid countercurrent, feel excellence.

Industrial utilizability

Nonwoven fabric of the present invention is if soaked by liquid, and thickness reduces can make this liquid effectively see through, and this liquid is difficult to residual from the teeth outwards nonwoven fabric after liquid sees through.

According to absorbent commodity of the present invention, can provide and return the absorbent commodity that liquid measure is few.

Claims (32)

1. a nonwoven fabric, is characterized in that:

Contain and comprise fusing point mutually different the 1st composition and the composite fibre of the 2nd composition, be formed with the hot melt contact that the intersection point thermal welding between a plurality of these composite fibres forms,

Thickness change while being changed to moisture state from drying regime is more than 15%,

Caliper recovery rate while being changed to drying regime again from moisture state is more than 70%,

As described composite fibre, containing the 1st composition and be acrylic resin or pet resin and the 2nd composition is that fusing point is lower than the resin of the 1st composition, the fiber that Young's modulus is 0.2～1.0GPa.

2. nonwoven fabric as claimed in claim 1, is characterized in that:

Described thickness change is more than 20%.

3. nonwoven fabric as claimed in claim 1, is characterized in that:

Described caliper recovery rate while being changed to drying regime again from moisture state is more than 80%.

4. nonwoven fabric as claimed in claim 1, is characterized in that:

Described Young's modulus is below 0.8GPa.

5. nonwoven fabric as claimed in claim 1 or 2, is characterized in that:

The part of the thin thickness that existence is processed to form by embossing and the thick part of this segment thickness, the formation fiber of a face side of the part that at least described thickness is thick is that Young's modulus is the described fiber of 0.2～1.0GPa.

6. nonwoven fabric as claimed in claim 5, is characterized in that:

The formation fiber of another face side of the part that described thickness is thick is that Young's modulus is greater than 1.0GPa, the fiber below 6.0GPa.

7. nonwoven fabric as claimed in claim 1, is characterized in that:

Young's modulus is in the described fiber of 0.2～1.0GPa, and the 1st composition is acrylic resin, and degree of crystallinity is below 60%.

8. nonwoven fabric as claimed in claim 7, is characterized in that:

Described degree of crystallinity is below 45%.

9. nonwoven fabric as claimed in claim 1, is characterized in that:

Young's modulus is in the described fiber of 0.2～1.0GPa, and the 1st composition is pet resin, and degree of crystallinity is below 45%.

10. nonwoven fabric as claimed in claim 9, is characterized in that:

Young's modulus is in the described fiber of 0.2～1.0GPa, and described degree of crystallinity is below 30%.

11. nonwoven fabric as claimed in claim 1, is characterized in that:

Young's modulus is that the described fiber of 0.2～1.0GPa is core-sheath-type composite fibre, and in the resinous principle of formation core more than 70% is acrylic resin or pet resin.

12. nonwoven fabric as claimed in claim 1 or 2, is characterized in that:

Described composite fibre is thermally extensible fiber.

13. nonwoven fabric as claimed in claim 11, is characterized in that:

When the resin of formation core is polypropylene, orientation coefficient is below 60%; During for polyethylene terephthalate, orientation coefficient is below 50%.

14. nonwoven fabric as claimed in claim 11, is characterized in that:

The resinous principle that forms the sheath portion of described core-sheath-type composite fibre is that density is 0.941g/cm ³above high density polyethylene (HDPE).

15. nonwoven fabric as claimed in claim 11, is characterized in that:

In described core-sheath-type composite fibre, the sectional area ratio of core and sheath portion is 2: 8～8: 2.

16. nonwoven fabric as claimed in claim 1 or 2, is characterized in that:

As described composite fibre, contain the thermally extensible fiber that its length is extended because of heating, a face side, have a plurality of protuberances and recess, form the thermally extensible fiber of this protuberance in their intersection point place welding, the heat seal strength on the top of protuberance is higher than the heat seal strength of bottom.

17. nonwoven fabric as claimed in claim 16, is characterized in that:

In protuberance, the fibre density on the top of this protuberance is lower than the fibre density of bottom.

18. nonwoven fabric as claimed in claim 1, is characterized in that:

It is the nonwoven fabric of single layer structure, and the ratio of the described fiber that in whole formation fibers of nonwoven fabric, Young's modulus is 0.2～1.0GPa is 50 quality %～100 quality %.

19. nonwoven fabric as claimed in claim 18, is characterized in that:

The ratio of the described fiber that in whole formation fibers of nonwoven fabric, Young's modulus is 0.2～1.0GPa is 80 quality %～100 quality %.

20. nonwoven fabric as claimed in claim 19, is characterized in that:

The ratio of the described fiber that in whole formation fibers of nonwoven fabric, Young's modulus is 0.2～1.0GPa is 90 quality %～100 quality %.

21. nonwoven fabric as claimed in claim 1, is characterized in that:

It is the nonwoven fabric of sandwich construction, and the ratio of the described fiber that in whole formation fibers of nonwoven fabric, Young's modulus is 0.2～1.0GPa is 50 quality %～100 quality %.

22. nonwoven fabric as claimed in claim 21, is characterized in that:

The ratio of the described fiber that in whole formation fibers of nonwoven fabric, Young's modulus is 0.2～1.0GPa is 80 quality %～100 quality %.

23. nonwoven fabric as claimed in claim 22, is characterized in that:

The ratio of the described fiber that in whole formation fibers of nonwoven fabric, Young's modulus is 0.2～1.0GPa is 90 quality %～100 quality %.

24. nonwoven fabric as claimed in claim 16, is characterized in that:

Protuberance is surrounded and is formed by continuous close-shaped recess.

25. nonwoven fabric as claimed in claim 16, is characterized in that:

The inside of protuberance is full of with the formation fiber of nonwoven fabric.

26. 1 kinds of absorbent commodities, is characterized in that:

It possesses face sheet, back-sheet and the absorber between two sheet materials, and described face sheet is the nonwoven fabric described in any one in claim 1～25.

27. absorbent commodities as claimed in claim 26, is characterized in that:

Described face sheet consists of the nonwoven fabric described in any one in claim 1～9, and in this nonwoven fabric, at least the face side towards this absorption side contains the fiber that Young's modulus is 0.2～1.0GPa.

28. absorbent commodities as claimed in claim 26, is characterized in that:

Described face sheet consists of the nonwoven fabric described in claim 16 or 17, and this nonwoven fabric configures to have the mode facing to user's skin of protuberance and recess in this nonwoven fabric.

29. absorbent commodities as described in any one in claim 26～28, is characterized in that:

It is sanitary napkin.

30. absorbent commodities as described in any one in claim 26～28, is characterized in that:

The thickness of described face sheet drying regime is 0.5～3mm.

31. absorbent commodities as described in any one in claim 26～28, is characterized in that:

The embossing rate of nonwoven fabric is 5～35%.

32. absorbent commodities as claimed in claim 31, is characterized in that:

The embossing rate of nonwoven fabric is 10～25%.