CN101074515A - Telescopic nonwoven fabric - Google Patents

Abstract

The invention discloses a Telescopic nonwoven fabric comprises elastic fiber and other elastic fiber or inelastic fiber which is different from the elastic fiber before, the block polymer comprises polymer block A whose main part is aromatic series vinyl-compounds with 10-50 weight % and polymer block B whose main part is the repeated unit in type (1). In the condition of 20 DEG C and 2 Hz, the elasticity storage modulus G' of the dynamic viscoelasticity is 1*104-8*106Pa, and the dynamic loss tangent of the dynamic viscoelasticity tan Delta is below 0.2. In type (1), random one or two in R1-R4 are methyl, the others are hydrogen atom.

Description

Flexible nonwoven fabrics

Technical field

The present invention relates to flexible nonwoven fabrics.

Background technology

The known various flexible nonwoven fabrics that contains the elastomer that constitutes by elastomer resin.For example in Japanese kokai publication sho 62-84143 communique, put down in writing following elastomer nonwoven fabric: contain microfiber, but this microfiber constitutes by containing at least about the A-B-A block copolymer of 10 weight % and the elastic composition of polyolefinic extrusion molding.But above-mentioned microfiber constitutes resin owing to contain polyolefin as it, so cause that therefrom expansion performance is insufficient.

Put down in writing following composite elastic material in Japanese kokai publication hei 5-272043 communique: have the anisotropic elasticity fiber web and the layer of the formed rivel that combines with this fiber web, wherein said anisotropic elasticity fiber web has elastomer meltblown fibers layer and elastomeric filament layer.The material that constitutes elastomeric filament is the elastomer polymer of 40～80 weight % and the resin binder of 5～40 weight %.Like this, elastomeric filament is owing to containing elastomer resin resin in addition, so cause that therefrom expansion performance is insufficient.

Put down in writing following Stretchable composite sheet in TOHKEMY 2002-361766 communique: have the elastic sheet material that is made of fiber or film, the styrene-content that described fiber contains 60～98 weight % is that 10～40 weight %, number-average molecular weight are 70000～150000 phenylethylene elastomer.In above-mentioned fiber or film, except the phenylethylene elastomer, also contain elastomer material, for example olefine kind resin or oil component in addition.Owing to contain these materials, make that the expansion performance of this Stretchable composite sheet is insufficient.

In Japanese kokai publication hei 4-11059 communique, put down in writing following flexible nonwoven fabrics: constitute by the elastomeric fiber of phenylethylene, described phenylethylene elastomer is to carry out hydrogenation by the two keys based on isoprene to block copolymer to obtain, and wherein said block copolymer is by constituting based on the polymer blocks A of styrene with based on the polymer blocks B of isoprene.But this nonwoven fabric has low modulus (modulus), and flexible hysteresis (hysteresis) does not claim fully.

Summary of the invention

The invention provides a kind of flexible nonwoven fabrics, it comprises the elastomer and other elastomer or non-elastic fiber different with this elastomer that contains block copolymer, and described block copolymer is made of based on the polymer blocks A of aromatic ethenyl compound with based on the polymer blocks B of the repetitive of following formula (1) expression 10～50 weight %'s; Described block copolymer is that the elastic energy storage modulus G ' of the dynamic viscoelastic measured under the condition of 2Hz is 1 * 10 20 ℃ and frequency ⁴～8 * 10 ⁶Pa, and be that the dynamic loss tangent value tan δ of the dynamic viscoelastic measured under the condition of 2Hz is (below mention first invent be meant this invention) 0.2 below 20 ℃ and frequency.

In the formula, R ¹～R ⁴In any one or two be methyl, all the other are hydrogen atom.

In addition, the present invention is by providing following flexible nonwoven fabrics, thereby realized above-mentioned purpose, and described flexible nonwoven fabrics comprises and contains the elastomeric elastomer of phenylethylene and other elastomer and/or non-elastic fiber different with this elastomer; The described melt viscosity that contains the formation resin of the elastomeric elastomer of phenylethylene is 100～700Pas in the time of 230 ℃, and fusion tension force is 0.2～2.0cN (below mention second invention be meant this invention).

In addition, in the following description, " the present invention " is meant the general name of first invention and second invention.

Description of drawings

Fig. 1 is the schematic diagram of the preferred embodiment of the expression flexible nonwoven fabrics that is used to make first invention.

Fig. 2 is the vertical view of an example of the expression fibre sheet material of implementing stretch process.

Fig. 3 (a) is the profile along the a-a line of CD direction of fibre sheet material shown in Figure 2.

Fig. 3 (b) is the profile corresponding to Fig. 3 (a) that has produced the state (extended state) of distortion between concavo-convex roller.

Fig. 3 (c) is the profile along the c-c line of CD direction of fibre sheet material shown in Figure 2.

Fig. 3 (d) is the profile corresponding to Fig. 3 (c) that has produced the state (extended state) of distortion between concavo-convex roller.

Fig. 4 is the schematic diagram of cross-section structure of an embodiment of the flexible nonwoven fabrics of second invention.

Fig. 5 is the schematic diagram that expression is used to make the preferred embodiment of flexible nonwoven fabrics shown in Figure 4.

Fig. 6 is that second fiber web in the device shown in Figure 5 forms the schematic diagram of an example of structure that device promptly spins the spinning die head of spray (spinningblown) device for spinning.

The specific embodiment

The present invention will be described according to embodiment preferred below.At first, first invention is described.The flexible nonwoven fabrics of first invention is the aggregate of rubber-like fiber.But, in the scope of not damaging telescopic resilience, can also contain a small amount of non-elastic fiber.The i.e. flexible nonwoven fabrics of first invention or only constitute or contain elastomer and non-elastic fiber and constitute by elastomer.The flexible nonwoven fabrics of first invention for example is the single-layer nonwoven that only is made of elastomer or contains elastomer and the single-layer nonwoven of non-elastic fiber.And in first invention, use the thermoplastic elastomer (TPE) that constitutes by specific block copolymer the resin that constitutes as elastomer.This block copolymer is characterised in that to have following structures and dynamic visco-elastic property.

The block copolymer that uses in first invention contains with the polymer blocks A of aromatic ethenyl compound as main body.As aromatic ethenyl compound, for example can list styrene, p-methylstyrene, a methyl styrene, to t-butyl styrene, α-Jia Jibenyixi, 1-chloro-4-methyl-benzene, to tert-butoxy styrene, dimethylaminomethyl styrene, dimethyl aminoethyl styrene, vinyltoluene etc.In the above-mentioned aromatic compound,, preferably use styrene from the viewpoint of industry.

Polymer blocks A contains 10～50 weight % in block copolymer, preferably contain 15～30 weight %.When the amount of the polymer blocks in the block copolymer is lower than 10 weight %, can not satisfy desired formability of block copolymer and heat resistance.When surpassing 50 weight %, the expansion performance of block copolymer and flexibility descend.

Except polymer blocks A, block copolymer also contains the polymer blocks B based on the repetitive of above-mentioned formula (1) expression.The amount of polymer blocks B in the block copolymer is the nubbin of the amount of the polymer blocks A in the block copolymer.That is, the amount of the polymer blocks B in the block copolymer is 50～90 weight %, is preferably 70～85 weight %.

Except the repetitive that contains formula (1) expression, can also contain the repetitive of following formula (2) expression among the polymer blocks B.The amount of the repetitive of formula (2) expression can contain 20 moles below the % in polymer blocks B, particularly can contain 10 moles below the %.The repetitive that much less, also can not contain formula (2) expression among the polymer blocks B.

In the formula, R ¹～R ⁴Definition as mentioned above.

Polymer blocks A in the block copolymer and the arrangement mode of polymer blocks B have variety of way.From making the good viewpoint of expansion performance of block copolymer, be preferably the arrangement mode of wire, preferred especially basic model is three blocks of A-B-A type.

Block copolymer also has following dynamic visco-elastic property except having above-mentioned structure.Thus, the flexible nonwoven fabrics that contains first invention of the elastomer that is made of this block copolymer is compared with flexible nonwoven fabrics in the past, has high-modulus, and flexible hysteresis becomes good.If have high-modulus, even then in the mass area ratio that reduces flexible nonwoven fabrics in order to improve gas permeability and skin sense of touch, thereby with the fabric thin situation of this nonwoven and reduce under the situation of fibre diameter of elastomer, also can bring into play good expansion performance, thereby be favourable.That is, flexible nonwoven fabrics extends easily, and the intensity when elongation state produce to shrink uprises.Therefore, the flexible nonwoven fabrics that contains first invention of the elastomer that is made of this block copolymer is particularly suitable as whole the sheet material that the skin that for example constitutes Breeches type disposable diaper coats face.

In addition, compare with other general elastomeric fibre, also have acomia viscosity, advantage that viscosity is little by the elastomer that block copolymer constitutes.Therefore, the flexible nonwoven fabrics that contains first invention of the elastomer that is made of this block copolymer also has good skin sense of touch.

Block copolymer is that the elastic energy storage modulus G ' of the dynamic viscoelastic measured under the condition of 2Hz is 1 * 10 20 ℃ and frequency ⁴～8 * 10 ⁶Pa is preferably 5 * 10 ⁴～5 * 10 ⁶Pa, more preferably 1 * 10 ⁵～1 * 10 ⁶Pa.In addition, block copolymer is that the dynamic loss tangent value tan δ of the dynamic viscoelastic measured under the condition of 2Hz is below 0.2 20 ℃ and frequency, is preferably below 0.1, more preferably below 0.05.The lower limit of tan δ value is not particularly limited, and is preferably the smaller the better, but the lower limit that present industrial technology can reach is about 0.005.

Above-mentioned elastic energy storage modulus G ' is the index of elastic component in the Measurement of Dynamic Viscoelasticity of expression block copolymer, promptly represents the index of hardness.On the other hand, dynamic loss tangent value tan δ is with elastic energy storage modulus G ' and elastic loss modulus G " ratio G "/G ' expression, be how many energy the expression block copolymer absorbs when being out of shape index.When the value of the elastic energy storage modulus G ' of block copolymer is lower than lower limit, because modulus is low, so flexible hysteresis is insufficient.When the value of G ' surpasses higher limit, because the modulus height, so need big power, sense of touch hardening during elongation.In addition, owing to produce surrender, residual deformation increases.On the other hand, when the dynamic loss tangent value tan δ of block copolymer surpassed above-mentioned higher limit, the residual deformation during distortion increased, and expansion performance is insufficient.

The Measurement of Dynamic Viscoelasticity of block copolymer is to carry out under 2Hz, the stretch mode at 20 ℃, frequency as mentioned above.The deformation that applies is 0.1%.The Physica MCR500 that concrete mensuration in the present embodiment is to use Anton Paar company to make carries out.In addition, to make length be that 30mm, width are that 10mm, thickness are the sheet of 0.8mm to sample.

Block copolymer can be for example synthetic with following operation.At first, in hydrocarbon solvents such as cyclohexanone, add aromatic ethenyl compound and conjugated diene compound according to suitable order, carry out anionic polymerisation with organo-lithium compound or sodium metal etc. as initator, obtain having copolymer based on two keys of conjugated diene.As conjugated diene compound, use for example 1,3-butadiene, isoprene, pentadiene, hexadiene etc.Especially preferably use isoprene.

Then, the two keys based on conjugated diene of this copolymer are carried out hydrogenation, obtain the block copolymer of target.From the viewpoint of heat resistance and weatherability, the hydrogenation rate based on two keys of conjugated diene is preferably more than 80%, be preferably more than 90% especially.Hydrogenation reaction can use the composite catalyst of precious metal catalyst, organic nickel compound, organic cobalt compound or these compounds and other organo-metallic compounds such as platinum, palladium to carry out.Hydrogenation rate calculates by iodine number deter mination.

As block copolymer, also can use commercially available product.As above-mentioned commercially available product, for example can list SEPTON (registration mark) 2004 and the SEPTON (registration mark) 2002 of the styrene-ethylene-propylene-styrene block copolymer that can obtain from the Kuraray of Co., Ltd..

In the elastomer that contains in the flexible nonwoven fabrics of first invention, resinous principle can only be made of above-mentioned block copolymer, also can contain above-mentioned block copolymer and constitute with other resin.When elastomer contained above-mentioned block copolymer and other resin, the content of the block copolymer in the elastomer was preferably 20～80 weight %, is preferably 40～60 weight % especially.

When elastomer contains above-mentioned block copolymer and other resin,, for example can use with the resin as raw material such as thermoplastic elastomer (TPE)s such as rubber or TPO elastomer, polyester elastomer, polyurethanes elastomer as this other resin.Above-mentioned resin also can make up two or more uses.The non-resilient resin of melting spinning such as the polyester resin that perhaps can use polyolefin resin that copolymer by polyethylene, polypropylene, propylene and ethene etc. etc. constitutes, constitute by polyethylene terephthalate etc., polyamide.

As the fibre morphology of elastomer, can list the individual fibers that (1) blend independent by above-mentioned block copolymer or this block copolymer and other resin constitutes; (2) with above-mentioned block copolymer and other resin as core-sheath-type that constitutes resin or parallel composite fiber etc.The preferred especially individual fibers that constitutes separately by above-mentioned block copolymer of using.

Elastomer can be any form in long fiber and the staple fibre.Long fiber is meant that length is the above fiber of 50mm, also comprises continuous fibers.Elastomer is preferably the form of continuous fibers.This is because when elastomer is continuous fibers, can be used to extend continuously from the hot blast of nozzle protuberance, and fibre diameter attenuates so have not only, and the advantage that also reduces of the deviation of fibre diameter.And situation about stretching under cold wind also has same tendency.Thus, the quality when seeing through nonwoven fabric becomes well, and the deviation of the expansion performance of nonwoven fabric reduces.If can obtain the thin fiber of fibre diameter, then can reduce the capacity of hot blast and cold wind, advantage is also arranged aspect manufacturing cost.

From the gas permeability of guaranteeing flexible nonwoven fabrics and the viewpoint that improves expansion performance, the fibre diameter of elastomer is preferably 5～400 μ m, is preferably 10～100 μ m especially.

In the flexible nonwoven fabrics of first invention, except above-mentioned elastomer, can also contain other elastomer.As other elastomer, can list the fiber of thermoplastic elastomer (TPE)s such as for example containing TPO elastomer, polyester elastomer, polyurethanes elastomer.When flexible nonwoven fabrics contained other elastomer, this other elastomer was preferably 5～80 weight % with respect to the ratio of flexible nonwoven fabrics, is preferably 5～50 weight % especially.

As mentioned above, the flexible nonwoven fabrics of first invention can also contain non-elastic fiber, as this non-elastic fiber, can list the fiber that for example is made of polyethylene (PE), polypropylene (PP), polyester (PET and PBT), polyamide etc.According to the form of elastomer, non-elastic fiber can be a staple fibre, also can be long fiber.In addition, non-elastic fiber can be hydrophilic, also can be water proofing property.As non-elastic fiber, also can use core-sheath-type or parallel type composite fibre, cut apart fiber, special-shaped section fiber, crimped fibre, heat-shrinkable fibre etc.These fibers can be used alone, and also can make up two or more uses.When non-elastic fiber was the composite fibre of core-sheath-type, preferred core was that PET, PP, sheath are low-melting point PET, PP, PE.Particularly when using above-mentioned composite fibre, and contain the bonding enhancing of heat fusing between the elastomer of above-mentioned block copolymer, so be preferred.

Particularly preferred non-elastic fiber is to contain polyolefin resin and the fiber that constitutes.As such fiber, can list in filament that (1) blend independent by polyolefin resin or multiple polyolefin resin for example constitutes, core-sheath-type composite fibre that (2) polyolefin resin constitutes sheath portion, (3) parallel composite fiber, the fiber that at least a formation resin is a polyolefin resin, (4) partitioning portion at least a be polyolefin resin cut apart fiber etc.As polyolefin resin, can list for example polyethylene, polypropylene, ethene-alpha-olefin copolymer etc.

Non-elastic fiber is preferably 20～80 weight % with respect to the ratio of flexible nonwoven fabrics, is preferably 30～70 weight % especially.

The flexible nonwoven fabrics of first invention is the aggregate that contains the rubber-like fiber.Manufacturing process as the rubber-like fiber has following method: from nozzle bore with fusion resin extruded, extrusion resin is stretched after the regulation multiplying power, the length that cuts into regulation for example several millimeters to tens of millimeters.Fiber with this method manufacturing is staple fibre (staple fibre).After the staple fibre that obtains is for example used the carding machine combing, by the hot blast that utilizes the hot blast mode blow or heat embossing melt bonded, utilize bonding agent bonding, utilize method such as interweaving of water spray carry out nonwoven fabricization.Promptly the flexible nonwoven fabrics of first invention can be for example hot blast method nonwoven fabric, heat bonding nonwoven fabric, chemical adhesion nonwoven fabric, jet net-spraying method nonwoven fabric etc.

Other method as the manufacturing process of rubber-like fiber for example has following method: from nozzle bore with fusion resin extruded, make the resin elongation of this molten condition of extruding, the meltblown that fiber is attenuated by hot blast; And the spun-bond process that the resin of semi-molten state is stretched by cold wind or mechanical stretching machine.In addition, also has a kind of spray method of spinning (spinning blown) as melt spinning method.Fiber with these method manufacturings is continuous fibers (long filament).Promptly the flexible nonwoven fabrics of first invention for example can be by spinning the nonwoven fabric that spray method, spun-bond process, meltblown etc. form.Be preferably especially by spinning the nonwoven fabric that spray method or meltblown obtain.Represented to be used to make the spinning die head 21 of the spray method of spinning that device had of the flexible nonwoven fabrics of first invention among Fig. 1.

No matter the flexible nonwoven fabrics of first invention is the nonwoven fabric of above-mentioned which kind of form, and the formation fiber of this nonwoven fabric is preferred to be maintained at fibre morphology.Thus, can make the flexible nonwoven fabrics softness of first invention, and can improve gas permeability.

In spinning the spray method, use the spinning die head, on this spinning die head, near the front end of the discharge nozzle of molten polymer, a pair of hot blast discharge portion is center and configuration relatively with the said nozzle, and a pair of cold wind discharge portion is center and configuration relatively with the said nozzle in its downstream.According to spinning the spray method, elongation that fused fiber produces because of hot blast and the cold stretch that produces because of cold wind are carried out continuously, therefore have the advantage of carrying out the shaping of elastic fibre easily.In addition, it is excessively intensive that fiber can not become, and the elastic fibre of the such thickness of similar staple fibre that can be shaped is so also have the advantage that can access the high nonwoven fabric of gas permeability.And then, according to spinning the spray method, can obtain the fiber web of continuous filament yarn.The fiber web of continuous filament yarn is compared with the fiber web of staple fibre, and the fracture when being not easy high the elongation taken place demonstrates flexibility easily, so extremely beneficial in first invention.

As the spinning die head that is used to spin the spray method, can use die head, the spy shown in Fig. 1 of for example special public clear 43-30017 communique to open the die head shown in Fig. 2 that die head, the spy shown in Fig. 2 of clear 62-90361 communique open flat 3-174008 communique.And then can use the die head shown in Fig. 1～Fig. 3 that speciallys permit No. 3335949 communique.

Fiber web through fibre forming is keeping fibre morphology bonding by heat fusing.As the heat fusing adhesive bonding method, can list that the hot blast that utilizes the hot blast mode blows or heat embossing bonding etc.Represented to be used for to make the hot-blast stove 24 of the hot blast mode that device had of the flexible nonwoven fabrics of first invention among Fig. 1.In hot-blast stove 24, can blow out the heated air that is heated to set point of temperature, particularly add hot-air.After fiber web was imported in the hot-blast stove, heated air connected towards the below or towards opposite direction or towards both direction forcibly from this fibroreticulate top.

The condition of hot blast is preferably: the hot blast air quantity is 0.4～3m/ second, and temperature is 80～160 ℃, and travelling speed is 5～200m/ minute, and heat treatment time was 0.5～10 second.Preferred especially hot blast air quantity likens to the normally used hot blast air quantity of hot blast method is big, and preferred especially hot blast air quantity is 1～2m/ second.

As heat embossing,, be preferably 100～400N/cm especially although for example line pressure also depends on and fibroreticulate thickness as processing object is preferably 50～600N/cm usually.In addition,, be preferably 50～160 ℃ usually, be preferably 80～130 ℃ especially although the heating-up temperature of knurling rolls also depends on the kind of formation resin of fiber and the travelling speed of fibre sheet material 10B.

Hot blast by the hot blast mode is handled, and can obtain the fibre sheet material 10B that fiber web forms one.Fibre sheet material 10B is the bar-shape that has certain width and extend in one direction.Fibre sheet material 10B then is transported in the weak engagement device 25.Weak engagement device 25 is made of the embossing device of metal system with metal knurling rolls 26 and relative configuration with it or resinous backing roll 27, disposes the protuberance that embossing is used on the circumferential surface of described knurling rolls 26 regularly.Implement heat embossing processing by 25 couples of fibre sheet material 10B of weak engagement device.Thus, obtained implementing the fibre sheet material 10A of embossing processing.In addition, by in that to utilize weak engagement device 25 to carry out the heat fusing that the heat embossing first being processed carries out bonding, fibroreticulate formation fiber is mutually melt bonded and form one, so the heat embossing processing that utilizes weak engagement device 25 to be carried out not is essential in first invention.Want to make when constituting fiber melt bonded solid, it is effective utilizing weak engagement device 25 to carry out heat embossing processing.In addition, according to weak engagement device 25, except constituting fiber melt bonded, can suppress the advantage of the balling-up of fibre sheet material 10A in addition.

Its processing conditions carries out for bonding the assisting of the heat fusing that is undertaken by hot-blast stove 24 by the heat embossing processing that weak engagement device 25 carries out, so can relatively relax.On the contrary, if the condition of heat embossing processing is too fierce, then the bulkiness of fibre sheet material 10A can suffer damage, and can cause the filming of fiber, thereby the feel and the gas permeability of the flexible nonwoven fabrics that finally obtains played reaction.Go out to send to set the line pressure of heat embossing processing and the heating-up temperature of knurling rolls from this viewpoint.

In the fibre sheet material 10A that obtains by heat embossing processing, as shown in Figure 2, has the junction surface 4 of a large amount of single independent dispersing point shapes.Junction surface 4 forms with the configuration pattern of rule.Junction surface 4 preferences as the flow direction (MD) of fibre sheet material 10A with and the both direction of vertical direction (CD) on form discontinuously.

The fibre sheet material 10A that has implemented heat embossing processing in weak engagement device 25 then is sent to stretching device 30.The structure of stretching device 30 is, the pivot branch of one or two concavo- convex roller 33,34 shifts one's position it up and down by known elevating mechanism, and both intervals can be regulated.As Fig. 1 and Fig. 3 (b) and (d), each concavo- convex roller 33,34 fits loosely between the large-diameter portion 32 of another concavo-convex roller 34 according to the large-diameter portion 31 of a concavo-convex roller 33, and the mode that the large-diameter portion 32 of another concavo-convex roller 34 fits loosely between the large-diameter portion 31 of a concavo-convex roller 33 is combined.Fibre sheet material 10A is nipped between two rollers 33,34 of this state, thus drawing of fiber sheet material 10A.

In this stretching process, as shown in Figures 2 and 3, preferably make the position consistency of the large- diameter portion 31,32 of the position at the junction surface 4 on the width of fibre sheet material 10A and concavo-convex roller 33,34.Particularly, as shown in Figure 2, the junction surface that a plurality of junction surfaces 4 form along the linearly arrangement of MD is listed in and has formed multiple row (illustrate among Fig. 2 10 row) on the fibre sheet material 10A, in Fig. 2, for to be positioned at the junction surface row R of the leftmost side ₁Beginning is from each junction surface row R of there every row ₁In the junction surface 4 contained, the position of the large-diameter portion 31 of a concavo-convex roller 33 is arranged to consistent with it, for the 2nd junction surface row R from the left side ₂Beginning is from each junction surface row R of there every row ₂In the junction surface contained, be arranged to the position of the large-diameter portion 32 of another concavo-convex roller 34 consistent with it.Among Fig. 2, the scope shown in the symbol 31,32 be expression fibre sheet material 10A be in the state of being nipped between two concavo- convex rollers 33,34 this constantly, with the equitant scope of circumferential surface of the large- diameter portion 31,32 of each roller.

When fibre sheet material 10A passes through between two rollers 33,34 under the state of being nipped between the concavo- convex roller 33,34, as Fig. 3 (b) and (d), junction surface 4 is overlapping with the large- diameter portion 31,32 of any one concavo-convex roller, on the other hand, not and the zone between the overlapping large-diameter portion of large- diameter portion 31,32, the zone between the promptly above-mentioned junction surface row R is stretched energetically by broad ways.Therefore, can be in the destruction that prevents junction surface 4, the part beyond the junction surface of drawing of fiber sheet material 10A effectively.Its result according to this manufacture method, can make effectively and has high scalability and the damaged and few good flexible nonwoven fabrics of outward appearance of balling-up.

By above-mentioned stretch process, the thickness of fibre sheet material 10A preferably is increased to 1.1 times～4 times before and after stretch process, especially preferably be increased to 1.3 times～3 times.Thus, the fiber of non-elastic fiber layer 2,3 produces plastic deformation and extends, thereby fiber is attenuated.

If the thickness of the fibre sheet material 10A before the stretch process is thin, then has the advantage in the space that the grey cloth that can reduce to carry and take care of fibre sheet material 10A rolls up.

Moreover by above-mentioned stretch process, comparing advantageous variant before the flexural rigidity of fibre sheet material 10A and the stretch process is 30～80%, and special advantageous variant is 40～70%.Thus, can obtain the good and soft nonwoven fabric of drapability.In addition, because the flexural rigidity height of the fibre sheet material 10A before the stretch process, so on transfer line, be not easy to make fibre sheet material 10A to play pleat, thereby be preferred.And, when stretch process, also be easy under the situation that does not play pleat, fibre sheet material 10A be processed, thereby be preferred.

Thickness and the flexural rigidity of fibre sheet material 10 before and after stretch process can be controlled by the spacing of the percentage elongation of non-elastic fiber, the embossed pattern of knurling rolls, concavo- convex roller 33,34 and thickness, the interlock amount of leading section.

Thickness is to try to achieve with following method after placing more than 2 days with the state of no loading flexible nonwoven fabrics under 20 ± 2 ℃, the environment of 65 ± 2%RH.With flexible nonwoven fabrics at 0.5cN/cm ²Loading under be clipped between the flat board, under this state, observe section with 25 times～200 times multiplying power with microscope, obtain the average thickness of each layer.In addition, obtain whole thickness by the distance between the flat board.Entering of relevant fiber, with the intermediate point that enters mutually as thickness.

For fear of bringing damage for fibre sheet material 10A, the preferred right and wrong of circumferential surface of the large- diameter portion 31,32 of concavo- convex roller 33,34 are sharp-pointed.For example, be preferably formed tabular surface into Rack as Fig. 3 (b) and (d).The width W of the front end face of large-diameter portion 31,32 (with reference to Fig. 3 (b)) is preferably 0.3～1mm, is preferably junction surface 4 0.7～2 times in the size of CD direction, is preferably 0.9～1.3 times especially.Thus, the fibre morphology of non-elastic fiber is not easy destroyed, can obtain high-intensity flexible nonwoven fabrics.

The spacing P of large-diameter portion (with reference to Fig. 3 (b)) is preferably 0.7～2.5mm.This spacing P is preferably junction surface 4 1.2～5 times in the size of CD direction, is preferably 2～3 times especially.Can obtain presenting the same outward appearance of cloth and the good flexible nonwoven fabrics of skin sense of touch thus.In addition, junction surface 4 is at the spacing of CD direction (adjacent junction surface row R on the CD direction ₁Between the interval or on the CD direction adjacent junction surface row R ₂Between the interval) be roughly 2 times of spacing P between the large-diameter portion so that the position relationship consistency, because fibre sheet material 10A is in the elongation of CD direction and the reason of necking (necking), if so in 1.6 times～2.4 times scope, then can make position consistency.

The extended state of fibre sheet material 10A on its width of sending from stretching device 30 is disengaged.Promptly extend and alleviated.Its result shows retractility among the fibre sheet material 10A, and this sheet material 10A shrinks along its width.Thus, obtain needed flexible nonwoven fabrics 10.In addition, when removing extended state, can remove extended state fully, also can in the limit of performance retractility, remove extended state down with the state that keeps extended state to a certain degree.

The thickness of the flexible nonwoven fabrics of first invention is preferably 0.05～10mm, is preferably 0.1～5mm especially.In addition, its mass area ratio is preferably 10～300g/m ², be preferably 20～160g/m especially ²Because thickness and mass area ratio are in above-mentioned scope, so the flexible nonwoven fabrics of first invention has the gas permeability and the flexibility of appropriateness, the skin sense of touch is good.Determination of thickness is to try to achieve with following method after placing more than 2 days with the state of no loading flexible nonwoven fabrics under 20 ± 2 ℃, the environment of 65 ± 2%RH.With flexible nonwoven fabrics at 0.5cN/cm ²Loading under be clipped between the flat board, under this state, observe the section of flexible nonwoven fabrics with 50～200 times multiplying power with microscope, obtain each average thickness within the vision respectively, and obtain the average thickness value of 3 field ranges.

Below second invention is described.Second invention not have the point that specifies, above can suiting to be suitable for to first explanation of inventing.In addition, in Fig. 4～Fig. 9, the parts identical with Fig. 1～Fig. 3 are with identical symbolic representation, and omit its explanation.The flexible nonwoven fabrics of second invention has elastic fibrous layer.The flexible nonwoven fabrics and first invention are same, can only be made of elastic fibrous layer, also can be laminated with stiff in fact non-elastic fiber layer as described later as shown in Figure 4 on its at least one face.Elastic fibrous layer contains elastomer.Elastic fibrous layer or only be made of elastomer perhaps contains elastomer and/or non-elastic fiber.Elastomer can use one or more.When containing non-elastic fiber in the elastic fibrous layer, non-elastic fiber can use one or more.

At least a fiber in the elastomer is to contain the elastomeric elastomer of phenylethylene.The elastomer that contains in the elastic fibrous layer or only be the elastomer that contains the elastomeric elastomer of this phenylethylene or this elastomer and other different with this elastomer.

Contain the elastomeric elastomer of above-mentioned phenylethylene or only constitute by this phenylethylene elastomer, perhaps contain this phenylethylene elastomer and other one or more resin and constitute.

The elastomeric elastomer of above-mentioned phenylethylene that contains that uses in second invention is characterised in that it constitutes the melt viscosity and the fusion tension force of resin.The melt viscosity that contains the formation resin of the elastomeric elastomer of above-mentioned phenylethylene is 100～700Pas in the time of 230 ℃.And the fusion tension force that contains the formation resin of the elastomeric elastomer of above-mentioned phenylethylene is 0.2～2.0cN.The melt viscosity of this scope is compared with the elastomeric melt viscosity of phenylethylene that uses in the past and is remained at low levels, and the fusion tension force of this scope is compared the higher level that is in the elastomeric fusion tension force of phenylethylene that uses in the past.That is, the formation fiber that contains the elastomeric elastomer of above-mentioned phenylethylene that uses in second invention is characterised in that to have low melting viscosity and high fusion tension force.By using by the elastomer that resin constitutes that constitutes with above-mentioned feature, the expansion performance of the flexible nonwoven fabrics of second invention is compared further raising with nonwoven fabric in the past.

Particularly, have low melting viscosity and high fusion tension force,, can easily make the continuous fibers of thin diameter so when elastomer is carried out melt spinning, be not easy to produce broken end owing to contain the formation resin of the elastomeric elastomer of above-mentioned phenylethylene.Elastomer can be made thin diameter and go far towards to avoid on the quality of nonwoven fabric, to produce inequality, and go far towards the raising of expansion performance.Elastomer can be made the raising that continuous fibers (long filament) also goes far towards expansion performance.Continuous fibers is meant that in fact continuously for example length is the above fiber of 10cm.

Moreover, have low melting viscosity and high fusion tension force owing to contain the formation resin of the elastomeric elastomer of above-mentioned phenylethylene, so be not easy to produce the flash of light streak (shot) that broken end causes.The result can obtain the good nonwoven fabric of skin sense of touch.So-called flash of light streak, the float that the fiber block that produces because of broken end when being meant melt spinning is such.The reason of its generation is, during melt spinning such as fruit fiber interrupt, then the fiber of Zhong Duaning will shrink, so fiber becomes nahlock.In case produce the flash of light streak, then nonwoven fabric feels rough.

From above viewpoint, the melt viscosity that contains the formation resin of the elastomeric elastomer of above-mentioned phenylethylene is set at 200～700Pas, when particularly being set at 300～600Pas, and expansion performance further improves.The elastomeric fusion tension force of phenylethylene is set at 0.2～1.5cN, when particularly being set at 0.5～1.5cN, same effect is arranged also.

The melt viscosity and the fusion tension force that contain the formation resin of the elastomeric elastomer of above-mentioned phenylethylene use fluidity test machine (キ ヤ ピ ロ グ ラ Off) (the smart mechanism of Japan) to measure.Condition determination is as described below.The drum diameter of plunger bushing (barrel) is 10mm, and piston diameter is 9.55mm.The diameter of the nozzle bore of die head is 1.0mm.Plunger bushing is remained on 230 ℃, resin particle bit by bit packed cylinder on one side use excellent extrusion packing on one side, to avoid sneaking into bubble.Behind the potting resin, resin temperature is kept about 5 minutes up to stable.Melt viscosity is 5mm/ minute viscosity stabilization point mensuration in piston speed.The shear rate of this moment is 60sec ^-1Fusion tension force is 15mm/ minute by measure piston speed under uniform temp, the tension force when draw speed is 15m/ minute is obtained.Measurement result is represented with the mean value of N=3.

Viscosity index during as the fusion of the resin that constitutes elastomer also can adopt in the art as referring generally to target melt index (ASTM D1238,190 ℃, 2.16kg).Melt index is preferably 4～50g/10min, more preferably during 6～20g/min, can be in temperature be set to the temperature range of extruder of lower than common forming temperature (for example 50～100 ℃ lower than forming temperature), the extruder resin when being shaped constrain make lower.In addition, melt index is certain specified temp viscosity index down only, and resin is along with its viscosity decline of rising of temperature, and its decline situation is according to the difference of resin and difference.Therefore, whether good melt index become expression formability a standard, but may not all situations all be fit to.

Present the viewpoint that is clamminess and feels from the viewpoint and the inhibition elastomer of further raising expansion performance, the elastomeric glass transition temperature Tg of above-mentioned phenylethylene that contains in the elastomer is preferably-40～-15 ℃, is preferably-30～-20 ℃ especially.

In addition, the elastomeric inflection temperature that obtains with differential scanning calorimetry (DSC) of above-mentioned phenylethylene is preferably 200～250 ℃, is preferably 215～250 ℃ especially.Its reason is, the adhesion of physical crosslinking point (the elastomeric situation of phenylethylene is between the styrene block) under the lower temperature a little less than, so the decline of viscosity increases during elevated temperature.

Elastomeric glass transition temperature of phenylethylene and the inflection temperature that obtains with DSC all can be measured by DSC and obtain.Measure under the condition determination that can be in nitrogen atmosphere the sample of 3～5mg be heated with 10/ minute programming rate from-60 ℃ of beginnings and obtain.

As long as satisfy above various rerum naturas, then the elastomeric kind of phenylethylene be not particularly limited.For example as monomer component, can list that (1) contains the monomer component of styrene, ethene and butylene (for example main chain backbone is SEBS), (2) contain the monomer component (for example main chain backbone is SEPS) of styrene, ethene and propylene, the monomer component (for example main chain backbone is SBS) that (3) contain styrene and butylene, the monomer component (for example main chain backbone is SIS) that (4) contain styrene and isoprene etc.Wherein, if use (1) contain the monomer component of styrene, ethene and butylene, monomer component that (2) contain styrene, ethene and propylene or (1) and (2) both, then can be satisfied the phenylethylene elastomer of above-mentioned various rerum naturas easily, so be preferred.

The elastomeric weight average molecular weight of phenylethylene of above-mentioned (1) and (2) is preferably 30,000～200, and 000, be preferably 50,000～150,000 especially.

The preferred especially phenylethylene elastomer that uses is the block copolymer of explanation in first invention.This block copolymer as mentioned above, by constituting of 10～50 weight % based on the polymer blocks A of aromatic ethenyl compound with based on the polymer blocks B of the repetitive of above-mentioned general formula (1) expression.And this block copolymer is that the elastic energy storage modulus G ' of the dynamic viscoelastic measured under the condition of 2Hz is 1 * 10 20 ℃ and frequency ⁴-8 * 10 ⁶Pa, and be that the dynamic loss tangent value tan δ of the dynamic viscoelastic measured under the condition of 2Hz is below 0.2 20 ℃ and frequency.

As mentioned above, containing the elastomeric elastomer of above-mentioned phenylethylene can only be made of as resinous principle this phenylethylene elastomer, also can contain this phenylethylene elastomer and other one or more resin and constitute.When elastomer contained above-mentioned phenylethylene elastomer and other resin, the elastomeric content of the phenylethylene in the elastomer was preferably 20～99 weight %, is preferably 50～80 weight % especially.When containing the elastomeric elastomer of above-mentioned phenylethylene and only be made of this phenylethylene elastomer, above-mentioned melt viscosity is identical with fusion tension force with the melt viscosity of this phenylethylene elastomer itself with fusion tension force.

When elastomer contains above-mentioned phenylethylene elastomer and other resin, as this other resin, can list with first invention in the identical resin of resin that contains in the elastomer that uses.

When elastomer contains above-mentioned phenylethylene elastomer and other resin,, can list the individual fibers that (1) is made of the mixed polymer of above-mentioned phenylethylene elastomer and other resin as the fibre morphology of this elastomer; (2) contain the form of the composite fibre of above-mentioned phenylethylene elastomer and other resin.As this composite fibre, can list core-sheath-type composite fibre, parallel composite fiber, cut apart fiber etc.

Even carrying out melt spinning separately, above-mentioned phenylethylene elastomer also has extraordinary spinnability.By comparison, phenylethylene elastomer in the past is because to carry out the spinnability of melt spinning separately poor, thus want and with other resin with the raising spinnability.But correspondingly, the original expansion performance that has of phenylethylene elastomer suffers damage.Therefore, never can damage the viewpoint of its retractility that had originally and set out, the above-mentioned phenylethylene elastomer that can carry out melt spinning separately is extremely beneficial.That is, in elastomer,, especially preferably only constitute by above-mentioned phenylethylene elastomer as resinous principle.

In addition, in the past,, carried out Fibrotic trial after having carried out making it to contain paraffin wet goods oil component in order to reduce the elastomeric melt viscosity of phenylethylene.Oil component oozes out on the surface of fiber sometimes, might reduce the melt bonded property with other resin therefrom.Contrast there is no need to add oil component in above-mentioned phenylethylene elastomer with it.Not the elastomer of oil composition can improve between the elastomer melt bonded property and and non-elastic fiber between melt bonded property.As a result, in aftermentioned embodiment shown in Figure 4, the joint between elastic fibrous layer 1 and the non-elastic fiber layer 2,3 becomes well, is not easy to take place splitting.And can suppress the surperficial balling-up of flexible nonwoven fabrics 10 '.Moreover owing to do not contain oil component, so when the melt spinning of elastomer, the generation of volatile ingredient tails off, carrying capacity of environment reduces.From these viewpoints, the elastomeric elastomer of phenylethylene that contains in second invention does not preferably contain oil component in fact.What is called does not contain in fact, and does not mean that and do not contain oil component fully, and the oil component of unavoidably sneaking into when making elastomer allows.

Elastomer can be any form in continuous fibers and the staple fibre, and elastomer is preferably the form of continuous fibers.The preferred elastic fiber of using in its reason and first invention is that the reason of continuous fibers is identical.

As mentioned above, the viewpoint from improving expansion performance, cost degradation, boosting productivity contains the elastomeric elastomer of above-mentioned phenylethylene except comprising in elastic fibrous layer, can also contain other elastomer different with this elastomer.As other elastomer, can use with first invention in the identical elastomer of other elastomer that uses.The usage ratio of this other elastomer is also identical with first invention.

In addition,, in elastic fibrous layer, contain the elastomeric elastomer of above-mentioned phenylethylene, can also contain non-elastic fiber except comprising from the viewpoint that improves skin sense of touch and feel, the viewpoint that improves intensity.Perhaps contain the elastomeric elastomer of above-mentioned phenylethylene and other elastomer different, can also contain non-elastic fiber with this elastomer except comprising.As non-elastic fiber, can list with first invention in the identical non-elastic fiber of non-elastic fiber that uses.When elastic fibrous layer contains elastomer and non-elastic fiber and constitutes, from the viewpoint that has good expansion performance, realizes high strength, has good skin sense of touch and improve feel, the former/latter's weight ratio is preferably 20/80～80/20, is preferably 30/70～70/30 especially.

As mentioned above, the flexible nonwoven fabrics of second invention and first invention similarly can only be made of elastic fibrous layer, also can be laminated with stiff in fact non-elastic fiber layer on its at least one face.The schematic diagram of cross-section structure of preferred embodiment of having represented the flexible nonwoven fabrics of second invention among Fig. 4.The formation of the flexible nonwoven fabrics 10 ' of the present embodiment is to be laminated with identical or different stiff in fact non-elastic fiber layer 2,3 on the two sides of elastic fibrous layer 1.

Elastic fibrous layer 1 is the aggregate that contains elastomer.Elastic fibrous layer 1 has the character that can stretch and produce contraction when having removed tensile force.In elastic fibrous layer 1, on a direction parallel with face, the residual deformation when it is shunk is preferably below 20%, is preferably below 10% especially at least.Preferably on any one direction of MD direction and CD direction, satisfy this value at least, more preferably on both direction, all satisfy this value.

The elastomer that contains in the elastic fibrous layer 1 can be made with the same method of manufacture method of the elastomer that uses in inventing with first.

Elastic fibrous layer 1 can be the form that contains the fiber web or the nonwoven fabric of elastomer.For example can be by spinning fiber web or the nonwoven fabric that spray method, spun-bond process, meltblown etc. form.Be preferably especially by spinning the fiber web that the spray method obtains.Use is spun the advantage of spray method as illustrated in first invention.

Although non-elastic fiber layer 2,3 has extensibility, it is stiff in fact fibrage.Here said extensibility, it can be the situation that constitutes the fiber itself elongation, constitute fiber itself not extend although also can be, but two fibers that the intersection point place heat fusing between fiber is bonding are separated from each other, or change by the stereochemical structure recurring structure that forms such as bonding of the heat fusing between the fiber by many fibers, or constitute fiber and broken, thereby any in the situation of fibrage overall elongated.

Fiber as constituting non-elastic fiber layer 2,3 can use the identical fiber of non-elastic fiber that can contain with the conduct that had before illustrated in elastic fibrous layer 1.Non-elastic fiber layer 2,3 can be the fiber web or the nonwoven fabric of continuous filament yarn or staple fibre.Particularly, from the viewpoint of the bulk non-elastic fiber layer 2,3 that can be formed with thickness, above-mentioned non-elastic fiber layer is the fiber web of staple fibre preferably.Two non-elastic fiber layers 2,3 can be the same or different at aspects such as the material that constitutes fiber, mass area ratio, thickness.Constituting fiber is under the situation of core-sheath-type composite fibre, and preferred core is PET, PP, and sheath is low-melting PET, PP, PE.When particularly using above-mentioned composite fibre, and the bonding grow of heat fusing between the formation fiber of elastic fibrous layer, be not easy genetic horizon and peel off, be preferred from this viewpoint.

The thickness of at least one in two non-elastic fiber layers 2,3 is preferably 1.2～20 times of thickness of elastic fibrous layer 1, is preferably 1.5～5 times especially.On the other hand, preferred its mass area ratio of at least one in the units concerned's area quality, two non-elastic fiber layers 2,3 is lower than the mass area ratio of elastic fibrous layer.In other words, the non-elastic fiber layer is preferably little than elastic fibrous layer than elastomer bed thickness and mass area ratio.Because thickness and mass area ratio satisfy aforesaid relation, just become the bulk fibrage that thickness is arranged so the non-elastic fiber layer is compared with elastic fibrous layer.Its result, flexible nonwoven fabrics 10 ' becomes softness and the good nonwoven fabric of feel.

The thickness of relevant non-elastic fiber layer 2,3 itself is preferably 0.05～5mm, is preferably 0.1～1mm especially.On the other hand, the thickness of relevant elastic fibrous layer 1 itself, preferably the thickness than non-elastic fiber layer 2,3 is little, particularly, is preferably 0.01～2mm, is preferably 0.1～0.5mm especially.Determination of thickness is to try to achieve with following method after placing more than 2 days with the state of no loading flexible nonwoven fabrics under 20 ± 2 ℃, the environment of 65 ± 2%RH.With flexible nonwoven fabrics at 0.5cN/cm ²Loading under be clipped between the flat board, under this state, observe section with 25 times～200 times multiplying power with microscope, obtain each average thickness within the vision respectively, and obtain the average thickness value of 3 field ranges.

The mass area ratio of relevant non-elastic fiber layer 2,3 itself from the viewpoint on the surface of even covering elastic fibrous layer and the viewpoint of residual deformation, is preferably 1～60g/m respectively ², be preferably 5～15g/m especially ²On the other hand, the mass area ratio of relevant elastic fibrous layer 1 itself, from the viewpoint of expansion performance and residual deformation, preferably the mass area ratio than non-elastic fiber layer 2,3 is big, particularly, is preferably 5～80g/m ², be preferably 10～40g/m especially ²

The fibre diameter of relevant formation fiber, the fibre diameter of the formation fiber of elastic fibrous layer 1 are preferably 1.2～5 times of fibre diameter of the formation fiber of at least one non-elastic fiber layer 2,3, are preferably 1.2～2.5 times especially.In addition, from the viewpoint of gas permeability and expansion performance, the fibre diameter of the formation fiber of elastic fibrous layer 1 is preferably more than the 5 μ m, is preferably especially more than the 10 μ m, is preferably below the 100 μ m, is preferably especially below the 40 μ m.On the other hand, the fibre diameter of the formation fiber of non-elastic fiber layer 2,3 is preferably 1～30 μ m, is preferably 10～20 μ m especially.That is, as the formation fiber of non-elastic fiber layer 2,3, the preferred use fiber thinner slightly than the formation fiber of elastic fibrous layer 1.Thus, can increase the melt bonded point of the formation fiber of the non-elastic fiber layer 2,3 that is positioned at the top layer.The increase of melt bonded point is effective to preventing that flexible nonwoven fabrics 10 from producing balling-up.And then, can obtain the good flexible nonwoven fabrics of skin sense of touch 10 by using thin slightly fiber.

As shown in Figure 4, elastic fibrous layer 1 and non-elastic fiber layer 2,3 keep engaging with whole face by the heat fusing of fiber intersection point is bonding under the state of fibre morphology at the formation fiber of elastic fibrous layer 1.That is, engagement state is different with the flexible nonwoven fabrics in the past of local engagement.In the flexible nonwoven fabrics 10 of the present embodiment that elastic fibrous layer 1 and non-elastic fiber layer 2,3 engage with whole face, the interface of elastic fibrous layer 1 and non-elastic fiber layer 2,3 and near, the intersection point heat fusing of the formation fiber of the formation fiber of elastic fibrous layer 1 and non-elastic fiber layer 2,3 is bonding, engages equably with whole face in fact.By engaging with whole face, can prevent to produce bulge between elastic fibrous layer 1 and the non-elastic fiber layer 2,3, promptly can prevent two separate and form the space.If between two-layer, produce bulge, the then one sense of elastic fibrous layer and non-elastic fiber layer forfeiture, the feel of flexible nonwoven fabrics 10 ' has a declining tendency.According to the present embodiment, can provide flexible nonwoven fabrics just like the such sandwich construction of the nonwoven fabric of individual layer with one sense.

So-called " the formation fiber of elastic fibrous layer 1 keeps the state of fibre morphology " be not even the nearly all formation fiber that is meant elastic fibrous layer 1 is deformed into the state of film shape or film one fibre structure yet under the situation that has been applied in heat or pressure etc.Because the formation fiber of elastic fibrous layer 1 is in the state that keeps fibre morphology, therefore has the advantage of flexible nonwoven fabrics 10 ' the sufficient gas permeability of the present embodiment of giving.

In the layer of elastic fibrous layer 1, the intersection point generation heat fusing that constitutes fiber is bonding.Equally, in the layer of non-elastic fiber layer 2,3, it is bonding that the intersection point of formation fiber also produces heat fusing.

In in two non-elastic fiber layers 2,3 at least one, be in its part and constitute that fiber enters into the state of elastic fibrous layer 1 and/or the part of elastic fibrous layer constitutes the state that fiber enters at least one non-elastic fiber layer 2,3.Owing to be in above-mentioned state, thereby can promote the integrated of elastic fibrous layer 1 and non-elastic fiber layer 2,3, prevent from more effectively between two-layer, to produce bulge.The result becomes layer and the layer combination of shapes state together with the surface of following each layer.In the formation fiber of non-elastic fiber layer, its part enters into elastic fibrous layer 1 and till the there, or penetrates elastic fibrous layer 1 and arrive another non-elastic fiber layer.When imagination on a macro scale in each layer separately during the face between the connected surfaces fiber, in the fibre space that the inboard from this towards layer forms, the part of other layer constitutes fiber and enters along the sectional thickness direction of above-mentioned layer.When the formation fiber of non-elastic fiber layer enters into elastic fibrous layer 1 and till the there time, this constitute fiber preferred further with the formation fiber interweaving of elastic fibrous layer 1 together.Equally, when the formation fiber of non-elastic fiber layer penetrates elastic fibrous layer 1 and when arriving another non-elastic fiber layer, this constitute fiber preferably with the formation fiber interweaving of another non-elastic fiber layer together.This can be when observing the thickness direction section of flexible nonwoven fabrics with SEM or microscope etc., and the fact that interlayer does not form the space in fact obtains confirming.In addition, said here " interweaving ", being meant the state that fiber fully is intertwined each other, the definition that interweaves does not comprise the state that fibrage only overlaps.Whether being in the state that interweaves for example can judge by the following method: will be when the state that fibrage only overlaps is peeled off fibrage required power and overlapping fibrage also are suitable for it and peel off the required power of fibrage after the bonding hot blast method of heat fusing and compare, in the time can confirming to have substantial difference between the two, can judge the state that interweaves that is in.

For the formation fiber that makes the non-elastic fiber layer enters into elastic fibrous layer and/or makes the formation fiber of elastic fibrous layer enter into the non-elastic fiber layer, preferably before carrying out the processing that the formation fiber heat fusing of the formation fiber of non-elastic fiber layer and elastic fibrous layer is bonding, at least one side of non-elastic fiber or elastomer is fiber web state (also not having the bonding state of heat fusing).Constitute the viewpoint that fiber enters into other layer from making, because compare the free degree of staple fibre with long fiber higher, thereby the fibrage of optimum fiber net state.

In addition, for the formation fiber that makes the non-elastic fiber layer enters into elastic fibrous layer 1 and/or makes the formation fiber of elastic fibrous layer enter into the non-elastic fiber layer, preferably use the hot blast method.By using the hot blast method, can make the formation fiber enter into relative fibrage easily, and the formation fiber is entered from relative fibrage easily.In addition,, can both keep the bulkiness of non-elastic fiber layer, and make the formation fiber of non-elastic fiber layer enter into elastic fibrous layer 1 easily again by using the hot blast method.Penetrate elastic fibrous layer 1 and arrive under the situation of another non-elastic fiber layer at the formation fiber that makes the non-elastic fiber layer, preferably use the hot blast method too.Especially preferably the hot blast method is used in the non-elastic fiber layer and the stacked back of elastic fibrous layer of fiber web state.At this moment, in elastic fibrous layer, it constitutes between fiber can heat fusing bonding.Moreover, illustrated in the manufacture method as described later, owing to implement the hot blast method under given conditions, and in order to make hot blast unobstructed and be provided with the air permeability of the gas permeability of flexible nonwoven fabrics, particularly elastic fibrous layer higher, thereby fiber is entered more equably.Can also use method beyond the hot blast method, for example blow the method for steam.In addition, also can use jet net-spraying method, needle point method etc., but this moment the non-elastic fiber layer bulkiness can suffer damage, perhaps the formation fiber of elastic fibrous layer can be gone to the surface and comes up, the feel of the flexible nonwoven fabrics that obtains has a declining tendency.

Particularly under the situation of the formation fiber interweaving of the formation fiber of non-elastic fiber layer and elastic fibrous layer 1, preferably only adopt the hot blast method to interweave.

In order to adopt the hot blast method to make fiber interweaving, suitably adjust the blowing pressure, blow speed of gas, fibrolaminar mass area ratio and thickness, fibrolaminar travelling speed etc. and get final product.Condition when adopt making common hot blast method nonwoven fabric then can not make the formation fiber of non-elastic fiber layer and the formation fiber interweaving of elastic fibrous layer 1.Illustrated in the manufacture method as described later, by implementing the hot blast method under given conditions, can obtain the flexible nonwoven fabrics of target in second invention.

The hot blast method generally is to make the gas that is heated to set point of temperature connect fibrolaminar thickness direction.In this case, can produce interweaving and fiber intersection point melt bonded of fiber simultaneously.But in the present embodiment, there is no need by making the fiber intersection point melt bonded between the formation fiber of hot blast method in each layer.In other words, the hot blast method is to enter into elastic fibrous layer 1 for the formation fiber that makes the non-elastic fiber layer, or in order to make the formation fiber interweaving of this formation fiber and elastic fibrous layer 1, and make the bonding and essential operation of formation fiber heat fusing of the formation fiber and the elastic fibrous layer of non-elastic fiber layer.In addition, the direction that fiber entered is along with the position relation of passing through between direction and non-elastic fiber layer and the elastic fibrous layer that is heated gas changes.The non-elastic fiber layer preferably makes the melt bonded hot blast method nonwoven fabric that becomes of fiber intersection point by the hot blast method in it constitutes fiber.

Can understand from above explanation, in the preferred version of the flexible nonwoven fabrics of the present embodiment, the thickness direction inside of substantially stiff non-resilient hot blast method nonwoven fabric, contain and constitute the elastic fibrous layer 1 that fiber has kept this state of fibre morphology, a part that becomes this hot blast method nonwoven fabric constitutes that fiber enters into the state of elastic fibrous layer 1 and/or the part of elastic fibrous layer constitutes the state that fiber enters into the non-elastic fiber layer.In preferred scheme, the formation fiber that the part of hot blast method nonwoven fabric constitutes fiber and elastic fibrous layer 1 only interweaves by the hot blast method.Because elastic fibrous layer 1 contains in the inside of hot blast method nonwoven fabric, so the formation fiber of elastic fibrous layer 1 is not present in the surface of flexible nonwoven fabrics in fact.This never can produce the viewpoint of the peculiar sense of being clamminess of elastomer, and to set out be preferred.

In the flexible nonwoven fabrics 10 ' of the present embodiment, as shown in Figure 4, on non-elastic fiber layer 2,3, be formed with small recess.Thus, the section of flexible nonwoven fabrics 10 ' undulate shape on microcosmic.This wave-like is illustrated in the manufacture method as described later, is that the stretch process by flexible nonwoven fabrics 10 ' produces.This wave-like does not have big bad influence to the feel of nonwoven fabric 10 ' itself.Be favourable from the viewpoint that obtains soft and good more nonwoven fabric on the contrary.

Although in Fig. 4, do not show, also can implement embossing processing to the flexible nonwoven fabrics 10 ' of the present embodiment.Embossing processing is carried out for the bond strength that further improves between elastic fibrous layer 1 and the non-elastic fiber layer 2,3.Therefore, if elastic fibrous layer 1 and non-elastic fiber layer 2,3 are fully engaged, then there is no need to carry out embossing processing by the hot blast method.In addition, although embossing processing is to make to constitute between the fiber to engage, it is different with the hot blast method, can not make to constitute between the fiber by embossing processing to interweave.

Below, the preferable production process of the flexible nonwoven fabrics 10 ' of the present embodiment is described with reference to Fig. 5.In Fig. 5, illustrate the preferred manufacturing installation that uses in the manufacture method of flexible nonwoven fabrics 10 ' of the present embodiment.In device shown in Figure 5, have fiber web formation portion 100, hot blast handling part 200 and extension section 300 successively towards the downstream from the upstream side of manufacturing process.

In fiber web formation portion 100, have the 1st fiber web and form device the 21, the 2nd fiber web formation device 22 and the 3rd fiber web formation device 23.Form device 21 and the 3rd fiber web formation device 23 as the 1st fiber web, use carding machine.As carding machine, can use with this technical field in the same carding machine of normally used carding machine, and be not particularly limited.On the other hand, form device 22, use and spin the spray device for spinning as the 2nd fiber web.In spinning the spray device for spinning, has the spinning die head, on this spinning die head, near the front end of the discharge nozzle of molten polymer, a pair of hot blast discharge portion is that the center disposes relatively with the said nozzle, and a pair of cold wind discharge portion is that the center disposes relatively with the said nozzle in its downstream.As spinning the spinning die head that uses in the spray method, for example can use the die head shown in Fig. 1～Fig. 4 of die head shown in special Fig. 2 that opens flat 3-174008 communique and No. 3335949 communique of special permission.

Hot blast handling part 200 has hot-blast stove 24.The structure of hot-blast stove 24 is identical with device shown in Figure 1.After 3 layers of overlapped fiber web were imported in the hot-blast stove, heated air connected towards the below or towards opposite direction or towards both direction forcibly from this fibroreticulate top.

Extension section 300 has weak engagement device 25 and stretching device 30.Stretching device 30 is adjacent with weak engagement device 25, is configured in the downstream of weak engagement device 25.The structure of weak engagement device 25 and stretching device 30 is identical with device shown in Figure 1.

Manufacture method to the flexible nonwoven fabrics that used the device with above structure describes below.At first, a pair of fiber web that configuration is made of identical or different non-elastic fiber on fibroreticulate each face that is made of elastomer.In addition, so-called " fiber web that constitutes by elastomer ", not only be meant the fiber web that only constitutes by elastomer, in the scope of the telescopic resilience that does not damage the elastic fibrous layer (layer of representing with symbol 1 among Fig. 4) that forms by this fiber web, also comprise the fiber web that except elastomer, also contains a small amount of non-elastic fiber.

As shown in Figure 5, in fiber web formation portion 100, use stiff staple fibre, make non-elastic fiber net 3 ', and it is transported continuously towards a direction by the carding machine that forms device 21 as the 1st fiber web as raw material.The elastic resin that use is made of phenylethylene elastomer etc. is as raw material, spray the spun fiber accumulations of device for spinning on the conveyer belt that constitutes by the capture WEB by form spinning of device 22 as the 2nd fiber web, make the elastic webs 1 ' of the continuous filament yarn that contains elastomer.With its from conveyer belt strip down and be layered in by the 1st fiber web form that device 21 forms and the non-elastic fiber net 3 ' that transports continuously towards a direction on.The stacked again non-elastic fiber net of making by the carding machine that forms device 23 as the 3rd fiber web 2 ' on this elastic webs 1 '.In the formation of elastic webs 1 ', use the advantage of spinning the spray method as illustrated in first invention.

In addition, after preferably making non-elastic fiber net 3 ' temporary transient melt bonded back or it is temporarily interweaved, directly pile up the elastomer of direct fabrics thereon by heat treatment.Like this, the free degree of elastomer uprises, and easily by wind etc. mutual fiber is further entered, so be preferred.Temporarily melt bonded as what undertaken by heat treatment, can list the hot-rolling method, add the knobbling rolls method, steaming process, hot blast method etc., as temporarily interweaving, can list needle point method, spraying etc.Particularly using hot-rolling method and hot blast method, is being preferred aspect the feel that can not damage nonwoven fabric and reducing aspect the device space.Non-elastic fiber net 3 ' is not preferably reeled in temporary transient melt bonded back or after temporarily interweaving, but directly piles up elastomer thereon with online state.In case reel, just might non-elastic fiber net 3 ' be shriveled because of winding pressure.Temporary transient purpose melt bonded and that temporarily interweave is, when direct melt spinning elastomer and when making its accumulation on fiber web, avoids this fiber web to be blown away by wind etc.

When elastic webs 1 ' for example is made of two kinds of fibers, particularly, when elastic webs 1 ' when containing the elastomeric elastomer of above-mentioned phenylethylene and constitute or when containing elastomeric elastomer of above-mentioned phenylethylene and non-elastic fiber and constitute with other elastomer different with this elastomer, the spinning die head that spins the spray device for spinning as shown in Figure 5 can use spinning die head shown in Figure 6.Spinning die head shown in Figure 6 has spinning-nozzle A and spinning-nozzle B replaces structure arranged.Contain the elastomeric resin of above-mentioned phenylethylene from spinning-nozzle A discharge.On the other hand, discharge other thermoplastic elastomer (TPE) or stiff resin from spinning-nozzle B.

3 fibroreticulate duplexers are sent in the hot-blast stove 24 of hot blast mode, are subjected to hot blast here and handle.Handle by hot blast, the intersection point heat fusing between the fiber is bonding, and elastic webs 1 ' engages with non-elastic fiber net 2 ', 3 ' on its whole.When hot blast was handled, preferably each layer fiber web also do not form one.It is bulk and have the state of thickness also can keep after hot blast is handled that each fiber web had thus, thereby obtain the good flexible nonwoven fabrics of feel.

Make the intersection point heat fusing between the fiber bonding except handling by hot blast, make outside each layer fiber web engage with whole face, also preferably make the part of the non-elastic fiber net 2 ' of the face that blows one side that mainly is arranged in hot blast constitute fiber and enter into elastic webs 1 '.In addition, preferably the condition of handling by the control hot blast makes the part of non-elastic fiber net 2 ' constitute fiber and enters into elastic webs 1 ', the formation fiber interweaving of further preferred and this fiber web 1 '.Perhaps preferably make the part of non-elastic fiber net 2 ' constitute that fiber penetrates elastic webs 1 ' and arrive in the non-elastic fiber net 3 ', and with the formation fiber interweaving of this fiber web 3 '.

Make the part formation fiber of non-elastic fiber net 2 ' enter into elastic webs 1 ' and/or make the part of elastic webs 1 ' constitute the condition that fiber enters into non-elastic fiber net 2 ', the condition of the hot blast in can inventing with first is similarly set.When using the high material of air permeability as the WEB used in the hot blast heat treatment and since air pass through be easy to make fiber further to enter.Equally, when going up direct fabrics elastic webs 1 ' at non-elastic fiber net 3 ', the wind when also being easy to by spinning makes the formation fiber of elastic webs 1 ' enter into non-elastic fiber net 3 '.Be used for the WEB of hot blast processing and the air permeability of the WEB of the direct fabrics that are used for elastomer and be preferably 250～800cm ³/ (cm ²S), be preferably 400～750cm especially ³/ (cm ²S).Above-mentioned condition also is preferred from making the viewpoint that enters equably behind the fiber softening and making the bonding viewpoint of fibers melt.And then, in order to make fiber interweaving, the hot blast air quantity can be set at 3～5m/ second, will blow pressure and be set at 0.1～0.3kPa.The air permeability of elastic webs 1 ' is that it is unobstructed that hot blast becomes, and fiber is entered more equably, thereby be preferred more than the 8m/ (kPas), when more preferably 24m/ (kPas) is above.In addition, the melt bonded good and maximum intensity of fiber increases.And then can also prevent balling-up.

In hot blast is handled, preferably when the part formation fiber of non-elastic fiber net 2 ' entered into elastic webs 1 ', the formation fiber of the formation fiber of non-elastic fiber net 2 ' and/or the formation fiber of non-elastic fiber net 3 ' and elastic webs 1 ' was bonding at their intersection point place heat fusing.At this moment, preferably according to making the elastomer after hot blast is handled keep the condition of fibre morphology to carry out the hot blast processing.That is, the formation fiber of preferred elastic fiber net 1 ' can not become film shape or film one fibre structure because hot blast handles.And, bonding between the formation fiber of non-elastic fiber net 2 ' in hot blast is handled, same at intersection point place heat fusing, between the formation fiber of elastic webs 1 ' and bonding between the formation fiber of non-elastic fiber net 3 ' at intersection point place heat fusing.

Hot blast by the hot blast mode is handled, and can obtain the fibre sheet material 10B that 3 fiber webs form one.Fibre sheet material 10B then is transported to extension section 300.Used the processing method of fibre sheet material 10B of the weak engagement device 25 of extension section 300 and stretching device 30 identical with first invention.Especially, in second invention, by having used the stretching of stretching device 30, the fiber of non-elastic fiber layer 2,3 produces plastic deformation and extends, thereby fiber attenuates, and in addition, also has non-elastic fiber layer 2,3 advantage more bulk, that the skin sense of touch is good and resiliency is good that becomes.

More than the flexible nonwoven fabrics of first of the explanation invention and second invention has the character that can stretch and produce contraction when having removed tensile force.Has retractility at least one direction of flexible nonwoven fabrics direction in its face of first invention and second invention.Has retractility on also can be in face all directions.At this moment, can not avoid the degree of retractility different because of the difference of direction.First invention is compared with flexible nonwoven fabrics in the past with the flexible nonwoven fabrics of second invention, has high-modulus, and flexible hysteresis is good.The direction of relevant maximal dilation, the degree of the retractility of the flexible nonwoven fabrics of first invention and second invention are that 100% o'clock loading of elongation is preferably 20～500cN/25mm, are preferably 40～150cN/25mm especially.Preferably on any one direction of MD direction and CD direction, satisfy this value at least, more preferably on both direction, all satisfy this value.And the residual deformation of the flexible nonwoven fabrics of first invention and second invention when making its contraction from extending 100% state is preferably below 15%, more preferably below 10%.So little value below 7% more preferably.Promptly Shen Suo hysteresis is good.

The flexible nonwoven fabrics of first invention and second invention can be used for various uses such as surgery usefulness clothing class and cleaning sheet from the viewpoint of its good hand feeling and anti pilling property, retractility, gas permeability.Be preferably used as the constituent material of absorbent commodities such as sanitary napkin and disposable diaper especially.For example, can be as the sheet material of the outer surface that constitutes disposable diaper, in order to give sheet material that waistline portion or waist, leg enclose elastic extensions such as portion etc.In addition, can be as the sheet material of the retractility alar part that forms sanitary napkin etc.In addition, even the position beyond above-mentioned also can be used to want to give the position of retractility etc.The mass area ratio of flexible nonwoven fabrics and thickness can suitably be adjusted according to its concrete purposes.For example when the constituent material as absorbent commodity used, the preferred unit area quality was 20～160g/m ²About, thickness is about 0.1～5mm.In addition, the flexible nonwoven fabrics of first invention and second invention is keeping fibre morphology because it constitutes fiber, so softness and gas permeability increase.The flexural rigidity of relevant yardstick as flexibility, it is nonwoven fabric low like this below the 10cN/30mm that first invention and second flexible nonwoven fabrics of inventing are preferably formed bending rigid value.Relevant gas permeability, preferred air permeability is more than the 16m/ (kPas).In addition, the maximum elongation rate of flexible direction is preferably more than 100%.

Flexural rigidity is measured according to JIS L-1096, and adopting cloth flexibility test device (handle-o-meter) is that 8mm, gap width are under the condition of 10mm in the amount of clamp-oning, the mean value when trying to achieve on each flow direction and rectangular with it direction bending.Air permeability is that the AUTOMATIC AIR-PERMEABILITYTESTER KES-F8-AP1 that adopts KATO TECH company to make measures air permeance resistance, and obtains its inverse.

The invention is not restricted to above-mentioned embodiment.For example, the flexible nonwoven fabrics of second invention contains the elastomeric elastomer of phenylethylene and other elastomer and/or non-elastic fiber different with this elastomer as long as comprise when seeing as nonwoven fabric integral body.Therefore, for example has the flexible nonwoven fabrics of 2 layers of elastic fibrous layer in second scope of invention.At this moment, an elastic fibrous layer comprises and contains the elastomeric elastomer of phenylethylene, or except comprising this elastomer, also comprise non-elastic fiber, another elastic fibrous layer comprises other elastomer different with containing the elastomeric elastomer of phenylethylene, or also comprises non-elastic fiber except comprising this elastomer.This nonwoven fabric can also have the non-elastic fiber layer more than 1 layer except having 2 layers of elastic fibrous layer.Moreover, only have by the flexible nonwoven fabrics that contains elastic fibrous layer that the elastomeric fiber of phenylethylene constitutes and the non-elastic fiber layer more than 1 layer also in second scope of invention.

In addition, the flexible nonwoven fabrics 10 ' of above-mentioned embodiment has the form of stacked identical or different stiff in fact non-elastic fiber layer 2,3 on the two sides of elastic fibrous layer 1, but replacing, also can be the form of 2 layers of structure of stacked non-elastic fiber layer on the one side of elastic fibrous layer.Perhaps also can be only by elastic fibrous layer constitute the form of single layer structure.The details of the flexible nonwoven fabrics of the form of these individual layers or 2 layers of structure can suit to be suitable for the relevant explanation to the flexible nonwoven fabrics 10 ' of the above-mentioned embodiment of 3-tier architecture.In addition, be used as the constituent material of absorbent commodity when the flexible nonwoven fabrics of 2 layers of structure, especially for contact with user's skin local time, from skin sense of touch and viewpoint such as prevent to be clamminess, preferably the non-elastic fiber layer is used towards skin one side of wearer.

In addition, when the nonwoven fabric of second invention is on the one side at least at elastic fibrous layer when configuration non-elastic fiber layer and the formation that forms, the structure of elastic fibrous layer and non-elastic fiber layer is not limited to structure shown in Figure 4.

In addition, in method shown in Figure 2, stretching is to carry out under not by the state of the minor diameter clamping of the large-diameter portion of a concavo-convex roller and another concavo-convex roller at fibre sheet material 10A, but interval is between the two narrowed down, under the state that fibre sheet material 10A is clipped between the two, stretch.That is, also can under the state that touches the end across fibre sheet material, stretch.In addition, stretching process also can use the spy to open the method for putting down in writing in the flat 6-133998 communique.

In addition, in above-mentioned manufacture method, be that fibre sheet material 10A is stretched along the CD direction, replace, also can stretch along the MD direction.

Below, by embodiment the present invention is described in further detail.But scope of the present invention is not subjected to the restriction of this embodiment.Short of specializing, then " % " and " part " represents " weight % " and " weight portion " respectively.

Embodiment 1-1

Present embodiment is first inventive embodiment.Use device shown in Figure 1 to make flexible nonwoven fabrics.At first form elastic webs according to following method.As block copolymer, use the SEPTON (registration mark) 2004 of the styrene-ethylene-propylene-styrene block copolymer of the Kuraray of Co., Ltd. system.The styrene that contains 18 weight % in this block copolymer is as polymeric blocks A, and the ethylene-propylene of 82 weight % is as polymeric blocks B.This block copolymer has been carried out Measurement of Dynamic Viscoelasticity, and the elastic energy storage modulus of result under 20 ℃ and 2Hz is 1.9 * 10 ⁵Pa, dynamic loss tangent value tan δ is 0.02.In addition, as the resin of the non-elastic fiber of different other with it, use the acrylic resin (homopolymerization) of MFR as 60g/10min.Use above-mentioned resin to form the elastic webs that the blended fiber by 2 kinds of resins constitutes.2 extruders are used in fibroreticulate formation, use extruder separately to make each resin be 290 ℃ of following fusions and extrude from spinning-nozzle at die head temperature, and the spray method is spun in employing makes fiber accumulations on WEB.Spinning-nozzle has the shape that each resin is alternately extruded.SEPS and polyacrylic weight rate are set at 50/50.The fibre diameter of elastomer is 25 μ m.The fibre diameter of non-elastic fiber is 18 μ m.Fibroreticulate mass area ratio is 15g/m ²

This fiber web is imported in heat-treating machine, blow hot blast and heat-treat with the hot blast mode.Heat treated condition is, the temperature on the WEB is 140 ℃, and the hot blast air quantity is 2m/ second, and blowing pressure is 0.1kPa, and the time of blowing was 15 seconds.The fiber web that has obtained containing 2 kinds of fibers by this heat treatment forms the fibre sheet material of one.

Then above-mentioned fibre sheet material is implemented heat embossing processing.Heat embossing processing uses the embossing device with the protruding roller of embossing and smooth metallic roll to carry out.As the protruding roller of embossing, use spacing to be the protruding roller of the point-like of the protuberance of 2mm as the spacing of 2mm, CD direction with a large amount of MD directions.The temperature of each roller is set at 120 ℃, and line pressure is set at 300N/cm.Obtain having formed the fibre sheet material at junction surface with the pattern of rule by this embossing processing.This fibre sheet material is implemented stretch process.Stretch process uses the stretching device with a pair of tooth space roller to carry out, and this tooth space roller has extension and engaged teeth groove on axis direction in circumferential surface portion.By stretch process above-mentioned fibre sheet material is stretched along the CD direction.Obtain 35g/m flexible on the CD direction thus ²Flexible nonwoven fabrics.In addition, the travelling speed of each operation is 10m/ minute.

Embodiment 1-2

Present embodiment is first inventive embodiment.As block copolymer, use the SEPTON (registration mark) 2002 of the styrene-ethylene-propylene-styrene block copolymer of the Kuraray of Co., Ltd. system.The styrene that contains 30 weight % in this block copolymer is as polymeric blocks A, and the ethylene-propylene of 70 weight % is as polymeric blocks B.This block copolymer has been carried out Measurement of Dynamic Viscoelasticity, and the elastic energy storage modulus of result under 20 ℃ and 2Hz is 3.0 * 10 ⁵Pa, dynamic loss tangent value tan δ is 0.03.In addition, employing and the same method of embodiment 1-1 obtain flexible nonwoven fabrics.

Comparative example 1-1

As block copolymer, use the HYBRAR (registration mark) 7311 of the styrene-ethylene base isoprene-styrene block copolymer of the Kuraray of Co., Ltd. system.The styrene that contains 12 weight % in this block copolymer, the vinyl isoprene of 88 weight %.This block copolymer has been carried out Measurement of Dynamic Viscoelasticity, and the elastic energy storage modulus of result under 20 ℃ and 2Hz is 1.0 * 10 ⁶Pa, dynamic loss tangent value tan δ is 0.3.In addition, employing and the same method of embodiment 1-1 obtain flexible nonwoven fabrics.

Comparative example 1-2

As block copolymer, use TUFTEC (registration mark) H1031 of the styrene-ethylene-butylene-styrene block copolymer of Asahi Chemical Corp's system.The styrene that contains 30 weight % in this block copolymer, ethene-butylene of 70 weight %.This block copolymer has been carried out Measurement of Dynamic Viscoelasticity, and the elastic energy storage modulus of result under 20 ℃ and 2Hz is 1.0 * 10 ⁷Pa, dynamic loss tangent value tan δ is 0.03.In addition, employing and the same method of embodiment 1-1 obtain flexible nonwoven fabrics.

Estimate

The characteristic of the flexible nonwoven fabrics that is obtained by embodiment and comparative example is as shown in table 1 below.The assay method of each project in the table is as described below.

＜elongation 100% o'clock intensity, residual deformation 〉

Be 50mm, be the test film of the size cutting-out rectangle of 25mm along perpendicular direction according to flexible direction along flexible nonwoven fabrics.Test film is installed on the cupping machine (Shimadzu Seisakusho Ltd.'s system).Chuck spacing during installation is set at 25mm.Make the flexible direction elongation 150mm (chuck at interval become 50mm) of test film with 300mm/ minute speed, make it get back to initial length with 300mm/ minute speed at once along test film, with the relation record of the percentage elongation of this moment and tensile force on record-paper.Percentage elongation is represented with following formula.

The length (mm) of percentage elongation (%)=elongation/initial length (mm) * 100

That is, in the said determination method, it is 100% that test film is extended up to percentage elongation.The tensile force of this moment is set at 100% o'clock intensity of elongation.

Can produce residual deformation when usually, elastomer extends.Residual deformation (%) is decided to be when 100% percentage elongation is got back to initial length (percentage elongation is 0%) (recovery process), and tensile force becomes 0 o'clock percentage elongation.Estimate expansion performance with residual deformation, residual deformation is more little, and then expansion performance is good more.The value of the preferred residual deformation in the flexible nonwoven fabrics of the present invention as mentioned above.

Table 1

		Embodiment 1-1	Embodiment 1-2	Comparative example 1-1	Comparative example 1-2
						Elastomer	Elastic energy storage modulus G ' (Pa)	1.9×10 5	3.0×10 5	1.0×10 6	1.0×10 7
Dynamic loss tangent value tan δ	0.02	0.03	0.3	0.03
					Non-elastic fiber		The resin kind	Polypropylene	Polypropylene	Polypropylene	Polypropylene
MFR	60	60	60	60
						Weight average molecular weight	124,000	124,000	124,000	124,000
The weight rate of elastomer and non-elastic fiber		50/50	50/50	50/50							50/50
					Extend 100% o'clock intensity (cN/25mm)		75	100	85	150
Residual deformation (%)		6	9	20							18

As can be known from the results of Table 1, the nonwoven fabric of embodiment is compared with the nonwoven fabric of comparative example, and residual deformation is little, and expansion performance is good.

Embodiment 2-1

Present embodiment is second inventive embodiment.Form elastic webs according to following method.As the resin that is used for elastomer, the melt viscosity when using 230 ℃ is 300Pas, the fusion tension force SEBS as 1.3cN.In addition, as the resin of other different with it non-elastic fibers, use the acrylic resin (homopolymerization) of MFR as 60g/10min (230 ℃, 2.16kg).Use above-mentioned resin to form the elastic webs that the blended fiber by 2 kinds of resins constitutes.2 extruders are used in the formation of fiber web 1, use extruder separately to make each resin be 290 ℃ of following fusions and extrude from spinning-nozzle at die head temperature, and the spray method is spun in employing makes fiber accumulations on WEB.Spinning-nozzle has the shape that each resin is alternately extruded as shown in Figure 6.SEBS and polyacrylic weight rate are set at 50/50.The fibre diameter of elastomer is 25 μ m.The fibre diameter of non-elastic fiber is 18 μ m.Fibroreticulate mass area ratio is 40g/m ²

This fiber web is imported in heat-treating machine, blow hot blast and heat-treat with the hot blast mode.Heat treated condition is, the temperature on the WEB is 140 ℃, and the hot blast air quantity is 2m/ second, and blowing pressure is 10kPa, and the time of blowing was 15 seconds.The fiber web that has obtained containing 2 kinds of fibers by this heat treatment forms the fibre sheet material of one.

Then fibre sheet material is implemented heat embossing processing.Heat embossing processing uses the embossing device with the protruding roller of embossing and smooth metallic roll to carry out.As the protruding roller of embossing, use spacing to be the protruding roller of the point-like of the protuberance of 2mm as the spacing of 2mm, CD direction with a large amount of MD directions.The temperature of each roller is set at 130 ℃, and line pressure is set at 300N/cm.Obtain having formed the fibre sheet material at junction surface with the pattern of rule by this embossing processing.

Fibre sheet material is implemented stretch process.Stretch process uses the stretching device with a pair of concavo-convex roller that alternately is formed with large-diameter portion and minor diameter on axis direction to carry out.Spacing P between the large-diameter portion is 1.0mm.By stretch processing fibre sheet material is stretched along the CD direction.Obtaining mass area ratio flexible on the CD direction thus is 40g/m ²Nonwoven fabric.In addition, the travelling speed of each operation is 10m/ minute.

Embodiment 2-2

Present embodiment is second inventive embodiment.As the resin that is used for elastomer, the melt viscosity when using 230 ℃ is 600Pas, the fusion tension force SEBS as 0.2cN.In addition, the same method of employing and embodiment 2-1 is made flexible nonwoven fabrics.The fibre diameter of elastomer is 30 μ m.The fibre diameter of non-elastic fiber is 18 μ m.The mass area ratio of elastic webs is 40g/m ²

Embodiment 2-3

Present embodiment is second inventive embodiment.Use device shown in Figure 5 to make flexible nonwoven fabrics shown in Figure 4.At first, be that 17 μ m, fibre length are staple fibre (core: PET, the sheath: PE) be supplied to carding machine, form the non-elastic fiber net 3 ' that is made of carding fiber net of 51mm with diameter.The mass area ratio of fiber web 3 ' is 10g/m ²Go up stacked elastic webs 1 ' at this non-elastic fiber net 3 '.

Form elastic webs 1 ' according to following method.As the resin that is used for elastomer, the melt viscosity when using 230 ℃ is 300Pas, the fusion tension force SEBS (SEBS) as 1.3cN.In addition, as the resin of other different with it elastomers, the melt viscosity when using 230 ℃ is 1500Pas, the fusion tension force SEBS (the 2nd SEBS) as 1.0cN.Use above-mentioned resin to form the elastic webs 1 ' that the blended fiber by 2 kinds of resins constitutes.2 extruders are used in the formation of fiber web 1 ', use extruder separately to make each resin be 290 ℃ of following fusions and extrude from spinning-nozzle at die head temperature, and the spray method is spun in employing makes fiber accumulations on WEB.Spinning-nozzle has the shape that each resin is alternately extruded as shown in Figure 6.The weight rate of the one SEBS and the 2nd SEBS is set at 80/20.The fibre diameter of the elastomer that is made of a SEBS is 25 μ m.The fibre diameter of the elastomer that is made of the 2nd SEBS is 35 μ m.The mass area ratio of fiber web 1 ' is 20g/m ²

Go up stacked by the non-elastic fiber net 2 ' that constitutes with above-mentioned same staple fibre in elastic webs 1 '.The mass area ratio of fiber web 2 ' is 10g/m ²

Above-mentioned 3 layers of fibroreticulate duplexer are imported in the heat-treating machines, blow hot blast and heat-treat with the hot blast mode.Heat treated condition is, the temperature on the WEB is 140 ℃, and the hot blast air quantity is 2m/ second, and blowing pressure is 10kPa, and the time of blowing was 15 seconds.Obtained the fibre sheet material 10B of 3 layers of fiber web formation one by this heat treatment.

Then fibre sheet material 10B is implemented heat embossing processing.Heat embossing processing uses the embossing device with the protruding roller of embossing and smooth metallic roll to carry out.As the protruding roller of embossing, use spacing to be the protruding roller of the point-like of the protuberance of 2mm as the spacing of 2mm, CD direction with a large amount of MD directions.The temperature of each roller is set at 120 ℃, and line pressure is set at 300N/cm.Obtain having formed the fibre sheet material 10A at junction surface with the pattern of rule by this embossing processing.

Fibre sheet material 10A is implemented stretch process.Stretch process uses the stretching device with a pair of concavo-convex roller that alternately is formed with large-diameter portion and minor diameter on axis direction to carry out.Spacing P between the large-diameter portion is 1.0mm.By stretch processing fibre sheet material 10A is stretched along the CD direction.Obtaining mass area ratio flexible on the CD direction thus is 40g/m ²Nonwoven fabric.In addition, the travelling speed of each operation is 10m/ minute.

Comparative example 2-1

As the resin that is used for elastomer, the melt viscosity when using 230 ℃ is 1500Pas, the fusion tension force SEBS resin as 1.0cN.In addition, as the resin of other different with it non-elastic fibers, use the acrylic resin (homopolymerization) of MFR as 60g/10min (230 ℃, 2.16kg).Use above-mentioned resin and embodiment 2-1 similarly die head temperature be 290 ℃ down with spinning spray method shaped resilient fiber web 1 ', elastomer can not attenuate as a result, quality difference and inhomogeneous can not obtain flexible nonwoven fabrics.Even die head temperature is increased to 320 ℃, elastomer is attenuated, quality difference and inhomogeneous can not obtain flexible nonwoven fabrics.

Estimate

The characteristic of the flexible nonwoven fabrics that is obtained by embodiment and comparative example is shown in following table 2 and table 3.The assay method of each project in the table is as described below.

＜intensity, percentage elongation and residual deformation 〉

Be 50mm, be the test film of the size cutting-out rectangle of 25mm along direction according to flexible direction with its quadrature along flexible nonwoven fabrics.Test film is installed on the TENSILON RTC1210A of ORIENTEC company manufacturing.The chuck spacing is 25mm.Make the flexible direction elongation of test film with 300mm/ minute speed, measure the loading of this moment along nonwoven fabric.With the loading of maximum point of this moment as maximum intensity.In addition, be B with test film length setting at this moment, when original test film length setting is A, in case (B-A)/and A} * 100 are maximum elongation rate (%).In addition, extend 100% cyclic test, obtain 100% o'clock intensity of elongation at 100% o'clock from the loading of extending.Moreover, after the elongation 100%, make it get back to initial point with identical speed, measure the ratio of irrecoverable length this moment, be worth as residual deformation with this.

＜flexural rigidity 〉

Using the smart mechanism of Daiei science to make made HOM-3 measures.

Table 2

				Embodiment 2-1	Embodiment 2-2	Embodiment 2-3
							Elastic fibrous layer	Elastomer	The resin kind		SEBS	SEBS	SEBS
Melt viscosity (Pas)		300	600	300
					Fusion tension force (cN)				1.3	0.2	1.3
Tg(℃)		-25	-28	-25
					The DSC inflection temperature (℃)				215	230	215
Melt index (g/10min)		6.3	3	6.3
					Elastic energy storage modulus G ' (Pa)				2.0×10 6	3.0×10 6	2.0×10 6
Dynamic loss tangent value tan δ		0.09	0.05	0.09
					Weight average molecular weight				137,000	94,000	137,000
Other elastomer	The resin kind		-	-								SEBS
					Melt viscosity (Pas)			-	-	1500
	Fusion tension force (cN)		-	-							1.0
					Tg(℃)			-	-	-60
	The DSC inflection temperature (℃)		-	-							220
					Melt index (g/10min)			-	-	0.2
	Weight average molecular weight		-	-							145,000
					Non-elastic fiber	The resin kind		Polypropylene	Polypropylene	-
MFR(g/10min)		60	60	-
						Weight average molecular weight		124,000	124,000	-
The weight rate of elastomer and other elastomer or non-elastic fiber			50/50	50/50							80/20
					Estimate	The elastic fibrous layer formability			○	○		○
Thickness (mm)		Before the stretching	0.40	0.45							0.55
						After the stretching	0.85	0.95	1.25
		Flexural rigidity (cN/30mm)		Before the stretching						1.8	2.0	2.2
After the stretching	1.4					1.5	1.2
				Maximum intensity (cN/25mm)				800	850	300
Maximum elongation rate (%)			260				250				230
				Extend 100% o'clock intensity (cN/25mm)				95	100	75
Residual deformation (%)			10				12				8

Table 3

				Comparative example 2-1
					Elastic fibrous layer	Elastomer	The resin kind		SEBS
Melt viscosity (Pas)		1500
			Fusion tension force (cN)				1.0
Tg(℃)		-60
			The DSC inflection temperature (℃)				220
Melt index (g/10min)		0.2
			Elastic energy storage modulus G ' (Pa)				8.5×10 6
Dynamic loss tangent value tan δ		0.03
			Weight average molecular weight				145,000
Other elastomer	The resin kind							-
			Melt viscosity (Pas)			-
	Fusion tension force (cN)						-
			Tg(℃)			-
	The DSC inflection temperature (℃)						-
			Melt index (g/10min)			-
	Weight average molecular weight						-
			Non-elastic fiber	The resin kind		Polypropylene
MFR(g/10min)		60
				Weight average molecular weight		124,000
The weight rate of elastomer and other elastomer or non-elastic fiber							50/50
			Estimate	The elastic fibrous layer formability				* can not sheet materialization
Thickness (mm)		Before the stretching					-
				After the stretching	-
		Flexural rigidity (cN/30mm)				Before the stretching	-
After the stretching	-
				Maximum intensity (cN/25mm)			-
Maximum elongation rate (%)			-
				Extend 100% o'clock intensity (cN/25mm)			-
Residual deformation (%)			-

From the result shown in table 2 and the table 3 as can be known, the nonwoven fabric of embodiment is compared with the nonwoven fabric of comparative example, and expansion performance is good.

In addition, observe the section of the nonwoven fabric of embodiment with SEM, in all as a result nonwoven fabric, it is bonding that the formation fiber of elastic fibrous layer and the formation fiber of non-elastic fiber layer have all produced heat fusing, and these fibrages engage with whole face.In addition, confirmed that the part formation fiber of non-elastic fiber layer enters into the thickness direction of elastic fibrous layer.The formation fiber of elastic fibrous layer is keeping fibre morphology.

As above detailed description, the flexible nonwoven fabrics of first invention is compared with flexible nonwoven fabrics in the past, has high-modulus, and flexible hysteresis is good.Therefore,, also show good expansion performance,, extend easily, have the convergent force of appropriateness so quality is thin and gas permeability and skin sense of touch are good even the flexible nonwoven fabrics of first invention reduces the use amount of elastomer.

The flexible nonwoven fabrics of second invention is compared with flexible nonwoven fabrics in the past, and expansion performance improves more.Particularly, because the fibre diameter that constitutes fiber is attenuated and the continuous fibers that is shaped easily, so can further improve expansion performance thus.Moreover, owing to do not contain other resinous principle and oil component, only form elastomer easily, so can further improve expansion performance thus by elastomer resin.In addition, when stacked non-elastic fiber layer on elastic fibrous layer, two-layer joint is good, is not easy to take place splitting.

Claims (11)

1, flexible nonwoven fabrics, it comprises the elastomer and other elastomer or non-elastic fiber different with this elastomer that contains block copolymer, and described block copolymer is made of based on the polymer blocks A of aromatic ethenyl compound with based on the polymer blocks B of the repetitive of following formula (1) expression 10～50 weight %'s; Described block copolymer is that the elastic energy storage modulus G ' of the dynamic viscoelastic measured under the condition of 2Hz is 1 * 10 20 ℃ and frequency ⁴～8 * 10 ⁶Pa, and be that the dynamic loss tangent value tan δ of the dynamic viscoelastic measured under the condition of 2Hz is below 0.2 20 ℃ and frequency,

In the formula, R ¹～R ⁴In any one or two be methyl, all the other are hydrogen atom.

2, flexible nonwoven fabrics as claimed in claim 1, wherein, polymer blocks B also contains the following repetitive with following formula (2) expression of 20 moles of %,

In the formula, R ¹～R ⁴Definition identical with the definition in the described formula (1).

3, flexible nonwoven fabrics as claimed in claim 1, wherein, the basic model of block copolymer is A-B-A.

4, flexible nonwoven fabrics as claimed in claim 1, wherein, described elastomer only is made of described block copolymer or contains described block copolymer and other thermoplastic elastomer (TPE).

5, flexible nonwoven fabrics as claimed in claim 1, wherein, described non-elastic fiber contains polyolefin resin.

6, flexible nonwoven fabrics, it comprises and contains the elastomeric elastomer of phenylethylene and other elastomer and/or non-elastic fiber different with this elastomer; The melt viscosity that contains the formation resin of the elastomeric elastomer of described phenylethylene is 100～700Pas in the time of 230 ℃, and fusion tension force is 0.2～2.0cN.

7, flexible nonwoven fabrics as claimed in claim 6, wherein, the elastomeric glass transition temperature Tg of described phenylethylene is-40～-15 ℃, the inflection temperature that is obtained by differential scanning calorimetry DSC is 200～250 ℃.

8, flexible nonwoven fabrics as claimed in claim 6, wherein, described phenylethylene elastomer is to contain styrene, ethene and the butylene elastomer as the monomer whose composition, or contains styrene, ethene and the propylene elastomer as the monomer whose composition, or above-mentioned two kinds of elastomers.

9, flexible nonwoven fabrics as claimed in claim 6 wherein, contains the elastomeric elastomer of described phenylethylene and only is made of this phenylethylene elastomer, or contains described phenylethylene elastomer and other thermoplastic elastomer (TPE).

10, flexible nonwoven fabrics as claimed in claim 6, wherein, this flexible nonwoven fabrics has elastic fibrous layer, and described elastic fibrous layer comprises described elastomer and/or the described non-elastic fiber that contains elastomeric described elastomer of described phenylethylene and other different with this elastomer; Described elastic fibrous layer at least the one side on dispose stiff in fact non-elastic fiber layer.

11, flexible nonwoven fabrics as claimed in claim 1, wherein, the melt viscosity of described block copolymer is 100～700Pas in the time of 230 ℃, and fusion tension force is 0.2～2.0cN.

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