JP3100300B2 - Composite elastic body having multi-stage elongation characteristics and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite elastic body composed of a nonwoven fabric and a sheet-like elastic body, which has different elasticity recovering properties depending on the degree of elongation. This composite elastic body is used for an elastic body used at a part directly in contact with the skin, for example, an elastic body provided at a waist and a crotch part of sanitary goods such as diapers for infants and adults, and a sleeve part of a medical gown. It can be used to advantage.

[0002]

2. Description of the Related Art In recent years, the use of elastic members has been increasing in disposable products such as medical supplies and sanitary articles for the purpose of improving fitness to the body. Is rarely used as it is, and is mostly used in the form of a composite with a nonwoven fabric. In a composite of a nonwoven fabric and a sheet-like elastic body, the sheet-like elastic body is required to have an elasticity function, and the nonwoven fabric is required to have a function of improving a surface state and a function of reinforcing the sheet-like elastic body.

A typical example of such a composite elastic body is disclosed in JP-A-62-84143 and JP-A-62-28456.
No. 62-33889, Kimberly, Inc., US Pat. M. S. (Spunbond /
There is a three-layer composite called meltblown / spunbond). This composite material is obtained by stretching a sheet-like elastic body, bonding the sheet-like elastic body to a nonwoven fabric in an elongated state, and then relaxing the sheet-like elastic body. B.
L. (Stretched Bonding Laminate). According to this method, the range of expansion and contraction is stable, and particularly, the limit expansion corresponds to the range of expansion at the time of manufacturing. Therefore, in a normal use state, there is no further expansion or breakage. However, the use of non-woven fabric more than necessary and the bulkiness of the finished product are disadvantageous for high-speed commercial production.

Japanese Patent Application Laid-Open No. Hei 4-28059 also discloses a system in which fibers are directly entangled with an elastic net, but there is a problem in cost. In order to compensate for these drawbacks, an attempt has been made to obtain a composite having a channel-like structure by line bonding with an elastic film using an extensible nonwoven fabric (Japanese Patent Application Laid-Open No. 5-222601).

[0005] The problem of the prior art as described above is that the elongation limit can be extended over a wide range from the breaking point of the nonwoven fabric to the breaking point of the sheet-like elastic body. It is uncertain whether there is, and there are difficulties in product design. Also, when worn, there is a feeling of anxiety that it is difficult to know how far the hair will break if stretched.

The present invention makes use of the inherent properties of the combined nonwoven fabric and sheet-like elastic body to produce a composite elastic body which is excellent in productivity and economical efficiency and is also excellent in function, and to manufacture this composite elastic body. It is intended to provide a way.

[0007]

According to the present invention, there is provided a nonwoven fabric having extensibility in at least one axial direction and having a breaking elongation of 100% or more in this elongation direction, and an elastic recovery rate of 6%.
A composite elastic body provided with a sheet-like elastic body having 0% or more and a breaking elongation of 200% or more, wherein the nonwoven fabric and the elastic body are connected to each other at a number of joints discontinuous in the elongation direction of the nonwoven fabric. Pre-extension for activation of elongation
By performing the elongation process within a range of 90% or less of the elongation at break,
The stress at 30% elongation obtained is less than 500g / 5cm
Acts as an extensible region (I) that is
The stress increase area (II) and the first stress drop point
(III) transition from the second extensibility region to the second extensibility region, and this transition
Second extensible region from region to second stress drop
(IV) is provided.

[0008] That is, the characteristic of the composite elastic body having an elongation activity of the present invention is that, in the process of uniaxially elongating in a predetermined direction,
Until the first elongation point is reached, the elongation is accompanied by a substantially constant increase in stress. However, when the elongation is further increased after the stress at the first inflection point is maximized, the stress sharply decreases to a certain value. As it continues to elongate, it elongates with a low level of stress and breaks when it reaches the second inflection point.

[0009] Taking a typical example of a composite elastic body,
This will be described with reference to FIG. The composite elastic body of this example is configured by joining the following nonwoven fabric and sheet-like elastic body with discontinuous dots in a direction substantially perpendicular to the elongation direction.

Nonwoven fabric: A hydroentangled web composed of polyester fibers obtained by a card method and having an aspect ratio of 1/4 and a basis weight of 20 g / cm ² .

Elastic body: E. FIG. B. S. 80 parts of resin,
E. FIG. V. A. A 40 μm film obtained by die extrusion of a compound composed of 20 parts.

The curve A in FIG. 1 shows the relationship between the elongation ratio (strain) and stress when the composite elastic body is stretched at a constant speed in the easy stretching direction (CD direction) of the nonwoven fabric (SS).
Curve). Curve B is an SS curve of only the nonwoven fabric, and curve C is an SS curve of only the elastic body.

[0013] The composite elastic body is stretched at first with a suddenly increasing stress with an increase in elongation, and then with an increasing rate of stress as the breaking point of the nonwoven fabric is approached. Then, when the breaking point of the nonwoven fabric is reached, the stress drops sharply. The first inflection point P1 is the breaking point of the nonwoven fabric, and the subsequent elongation is performed with a stress approximating the SS curve of the elastic body alone, and reaches the second inflection point P2. Sometimes breaks completely.

That is, the composite elastic body of the present invention has two stress drop points P1 and P2 in the process of being elongated in a predetermined direction. The first stress drop point P1 is caused by the nonwoven fabric being stretched beyond its extension limit, and the second stress drop point P2 is caused by the elastic body breaking.

The composite elastic body having such a multi-stage elongation characteristic can be advantageously used as a constituent material of a portion which comes into contact with the skin in various uses, particularly in medical or hygiene articles. A specific example is a material for waist gathers of diapers. The diaper's waist gathers are greatly stretched when attached and detached, so they have excellent elasticity and tear by mistake before reaching the breaking limit and knowing that further stretching is impossible. The inconvenience of can be avoided. In the composite elastic body of the present invention, as the elongation characteristic of a general nonwoven fabric, the stress increases as the elongation rate increases, so that the elongation limit can be felt. In addition, if the extension is given by mistake, the nonwoven fabric is broken and the stress as a whole is sharply reduced, but the elastic body is not broken. Until strength is reached, it is allowed by its elasticity.

The nonwoven fabric usable for the composite elastic body of the present invention has extensibility in at least one axial direction, and has a breaking elongation in this elongation direction of 100% or more, preferably 15% or more.
0% or more. When the elongation at break is less than 100%, the range of use as a stretchable material is significantly narrowed, and the practicality is reduced.

The elastic body needs to have an elastic recovery rate of 60% or more and an elongation at break of 200% or more.
Preferably it is at least 250%. If the elastic recovery is less than 60% and the elongation at break is less than 200%, the elasticity required for use in the above-mentioned applications cannot be obtained.

The difference between the breaking elongation of the nonwoven fabric and the breaking elongation of the elastic body is preferably as large as possible.
If it is above, it can be used advantageously for various uses.

The difference between the breaking elongation of the nonwoven fabric and the breaking elongation of the elastic body corresponds to the difference between the first stress drop point and the second stress drop point. This difference is preferably 50% or more.

The simplest form of the composite elastic body of the present invention is
It has a two-layer structure in which a single nonwoven fabric is bonded to a single elastic body, but a three-layer structure in which one elastic body is sandwiched between two nonwoven fabrics each consisting of one or more nonwoven fabrics Can also take a sandwich structure. Alternatively, a four-layer structure in which two elastic bodies each having a nonwoven fabric bonded to one surface thereof are overlapped and joined so that the surfaces to which the nonwoven fabric is not bonded face each other may be adopted. In any case, the nonwoven fabric is exposed on at least one surface of the composite elastic body.

When a nonwoven fabric having two-stage extensibility with different stress levels obtained by hydroentanglement is used as the nonwoven fabric, the level of the breaking strength at the time of the first stress drop due to the breaking of the nonwoven fabric increases. Thus, a composite elastic body having an excellent stopper effect can be obtained.

In the present invention, by appropriately selecting the following conditions, the range of properties that the sheet-like elastic body can have can be expanded, and the function of the elastic body can be further improved. .

Although the stretchability of the stretchable nonwoven fabric is not used in the normal state, the composite does not have stretchability, but the composite is given elastic stretchability such that stretching is activated only by stretching.

As the extensible nonwoven fabric, a nonwoven fabric by hydroentanglement is used, and by selecting the confounding conditions, a nonwoven fabric having good extensibility and a two-stage extensibility such that the stress is increased again from a certain point is used.

As a joining method, a joining structure is adopted in which the joining point is arranged substantially at right angles to the extension direction so as not to cause resistance to extension.

The bonding points of the nonwoven fabric on the front and back sides of the sheet-like elastic body are arranged so that the connection points on the front and back sides do not overlap, thereby preventing the occurrence of defective portions.

Due to the above structural considerations, it is possible to obtain a composite elastic body having good elongation and little residual strain and good stretch recovery.

More specifically, FIG. 2 shows an SS curve when a similar composite elastic body composed of a nonwoven fabric and a sheet-like elastic body is continuously elongated at a constant speed until it breaks. I have. The stress continues to rise until the elongation reaches around 250%, or the nonwoven fabric breaks when it sharply exceeds about 250%, and the stress sharply decreases. However, the reduction in stress stops at a certain value, and this condition continues until complete failure occurs.

On the other hand, the composite elastic body shown in FIG. 2 is preliminarily subjected to elongation activation by performing a pre-stretching treatment under a condition of not more than the breaking elongation of the nonwoven fabric, whereby the composite elastic body shown in FIGS. As shown, the initial elongation modulus decreases in accordance with the degree of pre-stretching, and the structure becomes very easy to elongate. For example, such pre-stretching reduces the stress at 30% elongation to 500 g / 5 cm or less.

FIG. 3 shows 75% (about 30% of the breaking elongation of the nonwoven fabric).
%), And FIG. 4 is 100% (about 40% of the breaking elongation of the nonwoven fabric).
%), And FIG. 5 shows 150% (about 60% of the breaking elongation of the nonwoven fabric).
3 shows an SS curve of a composite elastic body which has been subjected to the preliminary stretching of FIG. This pre-stretching treatment is desirably performed in the range of 30% to 80% with respect to the elongation limit of the nonwoven fabric. If it is less than 30%, a sufficient effect of the pre-stretching treatment cannot be expected. Be careful because there is a danger ahead.

By such pre-stretching treatment, as shown in FIG. 6, the stress at 30% elongation is 500 g / 0.5 c.
m, an extensible region (I) that is not more than m, a sharp stress increasing region (II) that acts as an elongation resistance toward the elongation limit of the nonwoven fabric when elongating more, and a first stress decrease. Transition area from the point to the second extension area (II
A unique SS characteristic having I) and a second extension region (IV) that reaches the second stress drop point via this transition region is exhibited.

When such a composite elastic body having the SS characteristic is applied to, for example, a waist band of an absorbent product, the elastic function of easily following the movement at the time of wearing, and the breakage based on the rise of stress. It is possible to provide both a stopper function that warns of the above and a function that provides a margin to prevent falling off even after breaking.

Such a change in the SS characteristics between before and after the pre-stretching is caused by a systematic change in the non-woven fabric itself and / or the joint between the non-woven fabric and the sheet-like elastic body due to the pre-stretching. Is clearly stated. This change helps the composite elastic body to exhibit excellent performance as an elastic body when used in various applications.

Regardless of the presence or absence of the pre-stretching treatment, the composite elastic body of the present invention exhibits excellent elasticity as an elastic body in the elongation range below the first stress drop point.

FIGS. 7 and 8 show S-type specimens obtained when two typical composite elastic bodies according to the present invention are stretched and relaxed from the unstretched state to 150% which is not more than the breaking elongation of the nonwoven fabric.
It shows an S-curve. This composite elastic body has a first
During the second stretching, a relatively high stress is exhibited due to the structural change of stretching of the two materials of the sheet-like elastic material and the nonwoven fabric, and the nonwoven fabric has already been stretched during the second stretching. Is greatly reduced, and the elasticity of the sheet-like elastic body is substantially expressed as it is. This is the same for the third and subsequent times. The occurrence of such a phenomenon is referred to as “elongation activation” in this specification.

Another major feature of the elongation activation is that, as shown in FIGS. 9 to 13, it exhibits elasticity within the range according to the elongation rate. Therefore, when this material is worn on the body, it expands and contracts in a range corresponding to the movement of the body, and it is possible to provide a very wasteful and flexible fitting structure.

As described above, the elongation activation may be naturally performed at the time of wearing or use after the composite elastic body is attached to the product as described above. However, industrially, before the production of the product or during the production of the product, It is desirable to perform the process by actively incorporating a process of elongation activation by pre-stretching. For example, in the case of manufacturing a product using the composite elastic body as a waist gather or a side elastic member of an absorbent product, for example, (1) When using a composite elastic body that has been activated in advance, And (2) the case where the composite elastic body is subjected to the elongation activation treatment during the manufacturing process. In the former case, the raw material becomes bulky, which makes storage and transportation difficult, but the latter does not have such a problem.
The latter may be more desirable. As a specific method, when feeding into the processing line, widening and expanding with a simple belt tenter or pin tenter device,
By incorporating a deep corrugated or gear-shaped roll into the processing line and performing a partial stretching process on the composite elastic body with this roll, the stretching activation is easily performed. In this case, care must be taken so that the nonwoven fabric does not damage the surface of the elastic body. For the composite elastic body that has been subjected to such extension activation in advance, the SS characteristic for the first extension activation as shown in FIGS. 7 to 13 disappears, and the easy extension property is reduced from the beginning. This shows the S-S characteristics possessed.

[0038] Desirable conditions for such an elongation-active type composite elastic body are that, as described above, the initial elongation does not exert much stress, and when the elongation exceeds a certain range, the resistance rapidly increases. Means that the brake is applied before the break occurs. It is also important that the material has the same elasticity even when it is repeatedly expanded and contracted many times. In other words, small residual strain is also an important performance of the substrate.

When these desirable conditions are represented by numerical values, they are as follows.

That is, when the composite elastic body is measured at a width of 5 cm, the SS curve at the time of the first expansion and contraction has the following characteristics.

The measurements of the physical properties shown below were carried out by a method generally used in this field and based on JIS standards. The main points are as follows. 1. 1. Sample sample Width: 5cm Length: 15cm 2. SS curve measurement conditions Chuck interval: 10 cm Loading speed: 20 cm / min Cycle test The load / unload is repeated three times at 150% elongation to obtain a hysteresis curve. Read the stress at 30% and 100% from the final return point of the hysteresis curve. In addition, the following 5-minute intervals were provided as relaxation times between each cycle.

First measurement → 5 minutes → Second measurement → 5 minutes → Third measurement Stress at 30% elongation This indicates the initial elongation stress, which is the force required for the first expansion when used. If it is too large, it will feel heavy and difficult to stretch, so it is necessary to suppress the stress to an appropriate level. Empirically, it is desirably 1000 g or less, preferably 800 g or less, and more preferably 600 g or less. Stress at 100% elongation This is a stress required for activation of elongation, and this stress differs depending on the usage condition of the object to be extended and used. In general, since the composite elastic body of the present invention has a great feature when used at high elongation, the stress at 100% elongation was selected as an evaluation point on the assumption that it is usually used at 100% or more.

For activation of elongation of the composite elastic body of the present invention, 1
At the time of 00% elongation, a stress of 400 g or more is required. Preferably, the stress is 600 g or more, and more preferably 800 g or more. Breaking strength Normally, 400 g or more is sufficient, but desirably 600 g or more improves the safety against accidental breakage in that a sense of resistance indicating the limit of elongation can be more clearly felt. I do.

In such a composite elastic body, the measured stress value after activation is greatly reduced due to the elongation activation. For example, when activated by elongation by 150%, the elongation stress of two or more times at 150% or less is significantly reduced. Such a reduction in elongation stress is desirable in view of the purpose of use of the composite elastic body of the present invention.

Then, the second SS curve was measured using the composite elastic body after elongation activation at 150%.
The following conditions are obtained. It is necessary to reduce the stress to at least 500 g or less by activation of stress elongation at 30% elongation, preferably 400 g or less, more preferably 300 g or less. By selecting such conditions, for example, even when the composite elastic body is used for an infant product, it is possible to avoid excessive compression. Stress at the time of 100% elongation The stress at the time of 100% elongation is greatly reduced after the activation of elongation, and it is easy to elongate.

Therefore, the strength is required to be 100 g or more, more preferably 200 g or more.

An important measure of the elongation recovery force is that the recovery rate is high. In other words, a structure having a small residual strain is desirable. This elongation recovery rate is generally 1
After the elongation recovery at 50% is repeated three times, the performance is evaluated by measuring, and expressed as a recovery rate under such conditions, it is 60% or more, preferably 70% or more.

Next, the members constituting the composite elastic body having such a stretch recovery property will be described.

First, the sheet-like elastic material used is preferably selected from materials having an extensibility of at least 200% and an elongation recovery of at least 60%. Examples of such materials having high performance include urethane, rubber latex foams, isoprene, butadiene-based synthetic rubber films, styrene-based elastomer films such as SIS, SEBS, and SEPS, and polyolefin-based elastomers such as EVA, EMA, and EPDM. Film and polyurethane, S
Melt blown elastomer nonwoven fabrics such as IS and SEBS. Particularly desirably, S having good thermal adhesion is used.
Examples include films, net-shaped molded articles, and melt-blown nonwoven fabrics made of styrene-based elastomers such as IS and SEBS and blended elastomers.

The nonwoven fabric which is another component constituting the composite elastic body of the present invention will be described.

The nonwoven fabric used in the present invention must have high extensibility in the MD or CD direction. Unlike a nonwoven fabric that is particularly easily extensible in the CD direction, a nonwoven fabric that is extensible also in the MD direction has C
It is unavoidable to slightly sacrifice extensibility in the D direction.
Nonwoven fabrics obtained industrially at low cost have specific extensibility in the CD direction. Such non-woven fabrics include non-woven fabrics obtained by hydroentanglement of parallel webs, non-woven fabrics obtained by opening and widening continuous tow fibers, and those obtained by parallelizing spunbond or meltblown, and the like. However, considering the industrial availability, they are roughly divided into the following three groups.

Group 1 The ratio of the elongation percentage in the MD direction to the CD direction (MD / CD
Ratio) of 2 or more, preferably 3 or more, a nonwoven fabric which is hydroentangled using a card web having fibers oriented in the MD direction as a raw material, or a nonwoven fabric obtained by further stretching this nonwoven fabric. This group will be described later in detail.

Group 2 A dry nonwoven fabric, a spunbonded nonwoven fabric or a meltblown nonwoven fabric having an MD / CD ratio of 2 or more, preferably 3 or more, in which the fibers are oriented in the MD direction, which has been parallelized by hot drawing. In addition, a spunbond consisting of a conjugate fiber using a readily soluble polymer such as polyethylene or PET derivative in the sheath and a heat stable polymer such as polypropylene or PET in the core is heated to around the melting point of the easily soluble polymer. Stretched. This nonwoven fabric is thin, has a high degree of orientation in the parallel direction, has no fluff, and is particularly suitable for the present invention.

Group 3 A dry nonwoven fabric, spunbonded nonwoven fabric or meltblown nonwoven fabric having an MD / CD ratio of 2 or more, preferably 3 or more, oriented in the MD direction, along the MD direction, that is, a direction perpendicular to the CD direction. Nonwoven fabric provided with a large number of fine slits, thereby improving extensibility in the CD direction.

The specific value of the extensibility in the MD or CD direction is desirably 100% or more, and more desirably 200% or more.

Due to such extensibility of the nonwoven fabric, it is possible to make the nonwoven fabric follow the behavior of the sheet elastic body by combining it with the sheet elastic body.

The nonwoven fabric has not only such extensibility but also another important performance. That is, when the amount of extension exceeds a certain amount, it shows resistance against further extension.

The nonwoven fabric which can be used most advantageously in the present invention is
It is a hydroentangled nonwoven fabric. This hydro-entangled nonwoven fabric is shown in FIG.
As shown in the figure, it shows almost no elasticity in the MD direction, but shows a large elasticity in the CD direction. When the elongation is about 200%, the stress once increases greatly, and further elongates with this stress. At break point (approximately 260% elongation).
The second-stage stress rise acts as a brake before breaking. Such stress increase point is 150%
Desirably higher than the elongation, more preferably 200
Design to happen at% or more.

In order to exhibit such optimum stretching performance, it is important to combine the fiber configuration of the web with the conditions of hydroentanglement. For example, a nonwoven fabric having the following configuration satisfies such conditions.

Composition of Web A relatively short fiber of about 25 mm to 45 mm and a relatively long fiber of 45 mm to 60 mm are combined as raw staple fibers.

○ Combine fibers that shrink and cause crimping.

Selection of conditions for water entanglement After the entire surface is joined with a fine nozzle, it is partially joined strongly. For example, a three-stage nozzle is used. First stage nozzle diameter: 0.15 mmφ Nozzle interval: 0.5 mm Water pressure: 30 kg / cm ² Second stage nozzle diameter: 0.15 mmφ Nozzle interval: 0.5 mm Water pressure: 50 kg / cm ² Third stage nozzle diameter: 0. 20 mmφ Nozzle interval: 1.0 mm Water pressure: 60 kg / cm ² Thus, a hydroentangled nonwoven fabric having a stripe pattern extending in the MD direction is obtained.

The composite elastic body of the present invention has a structure in which such an extensible nonwoven fabric is bonded to the surface of a sheet-like elastic body or to both front and back surfaces. The connection method may be basically any connection method, but the performance of the obtained composite elastic body may differ depending on the connection method applied. The following factors are important in any connection method.

The bonding is performed such that the direction of easy extension of the nonwoven fabric and the direction of easy extension of the sheet-like elastic body are matched.

A bonding pattern is adopted so that the bonding portion does not hinder the above-mentioned elongation as much as possible. In other words, it is desirable to minimize the number and area of the connecting points in the extending direction. Such bonding can be easily realized by distributing the bonding points in a range of preferably 90 ° ± 10 ° with respect to the elongation direction of the nonwoven fabric.

In the case where the nonwoven fabric is bonded to both sides of the sheet-like elastic body, the gap between one nonwoven fabric and the sheet-like elastic body is
Also, the arrangement of the joints formed between the other nonwoven fabric and the sheet-like elastic body causes a great difference in the stretch characteristics.

Assuming that the thickness of the elastic film in the double-sided bonded structure of the sheet-like elastic body and the nonwoven fabric is, for example, 50 μm, the film thickness can be achieved with one 50 μm film or two 25 μm films. Therefore, as a combination of a sheet-like elastic body and a nonwoven fabric, FIG.
The three cases shown in FIG. 17 can be considered. (1) Two sheet-like elastic bodies 1 each having a thickness of 25 μm
The two composite sheets 20A and 20B, in which the nonwoven fabrics 21 and 22 are joined to the first and second nonwoven fabrics 21 and 22 at the joining portion 3, are stacked, and the sheet-like elastic body 1
1 are joined by means such as a hot press 4 (FIG. 15). (2) Sheet-like elastic bodies 11, 1 each having a thickness of 25 μm
In the case where two composite sheets each having a nonwoven fabric bonded to the composite sheet 2 are stacked, and the sheet-like elastic bodies are bonded to each other at a bonding section 3 by means such as hot pressing (FIG. 16). (3) A case where two nonwoven fabrics 21 and 22 are overlaid on both surfaces of one elastic film 13 having a thickness of 50 μm and are joined by the joint 3 (FIG. 17).

Here, when the SS curve of the structure shown in FIGS. 15 to 17 is measured, when the length after releasing the tension after 100% elongation is compared with the length before the elongation, (3) It was found that the elastic recovery was improved in the order of (2) and (1) over (2).

In particular, in the case of FIG. 15, the position of the joint 3 between the first set of elastic films 11 and the nonwoven fabric 21 and the joint 3 between the second set of elastic films 12 and the nonwoven fabric 22 are shown.
Are arranged so as to be out of phase so that they do not overlap with each other. In this case, since the position of the joint 3 where the tensile stress tends to concentrate is different between the front and back sides, the tensile strength Becomes better.

In the composite elastic body of the present invention, the form of the joint between the nonwoven fabric and the elastic body is also an important factor. Optimal S-
In order to obtain S characteristics, it is necessary to adopt a bonding form that does not reduce the characteristics of the nonwoven fabric and the characteristics of the sheet-like elastic body. The condition required for this connection is that the connection is discontinuous with respect to the desired direction of elongation. In other words, there is a non-bonded portion between the adjacent bonded portions, and this non-bonded portion gives the composite sheet sufficient extensibility. Also, in the direction intersecting with the elongation direction, it is preferable that each connecting portion is discontinuous so as not to hinder the overall flexibility.

A pattern of a joint portion satisfying such a condition is typically a set of dots having an arbitrary shape such as a circle, a square, and a polygon. These dots may be uniformly distributed over the entire surface of the composite elastic body, but it is also effective to distribute an arbitrary number of sets of joints in an arbitrary pattern.

From an industrial point of view, two relatively thin sheets each having a nonwoven fabric bonded to only one side of the sheet-like elastic body are prepared, and these sheets are overlapped and joined so that the respective sheet-like elastic bodies face each other. Therefore, making a composite elastic body having a nonwoven fabric on both sides is advantageous in increasing production efficiency,
In particular, when a polystyrene-based elastomer film such as SIS or SEBS is used as the sheet-like elastic body, it is extremely rich in self-adhesion, so that it is possible to perform stable double-sided bonding only by pressing two film surfaces together and pressing. It is possible to make a body. This greatly improves productivity and has a great effect on cost reduction.

Regarding the bonding pattern between the nonwoven fabric and the elastic body, the bonding is performed only when the bonding is performed on only one side, or FIGS.
In the composite elastic body in which the nonwoven fabric is joined to the upper and lower surfaces of the elastic body as shown in (1), the connecting portion 3 is formed in a direction substantially orthogonal to the sheet-like elastic body and the nonwoven fabric in the direction of easy extension, preferably 9
It is shown as a strip extending in the direction of 0 ° ± 10 °. This band-shaped connecting portion may be one that bonds the sheet-like elastic body and the nonwoven fabric without a gap in a predetermined area, or from a form of a line or a dot having an arbitrary pattern distributed in the predetermined bonding area. It is also possible to use a connecting part row in which a number of connecting parts are arranged in a predetermined direction.

FIG. 18 to FIG. 20 show typical examples of the pattern of the connecting portion row composed of a set of discontinuous connecting portions. That is, in FIG. 18, a plurality of connecting portion rows 3 extending in directions parallel to each other, in which relatively short linear connecting portions 31 are arranged at appropriate intervals in a direction substantially orthogonal to the direction of easy extension of the composite elastic body.
0 is formed. In the example of FIG. 19, a large number of connecting portions 31 constituting the connecting portion row 30 are oriented substantially perpendicular to the length direction of the connecting portion row. In the case of FIG. 20,
Each coupling portion 31 has a shape similar to “x”. Each connecting portion 31 may have any shape other than the illustrated shape.

Alternatively, as shown in FIG. 21, a pattern in which fine dots are arranged at an appropriate density along a lattice constituted by two sets of parallel lines intersecting at an appropriate angle, and as shown in FIG. Also, a pattern in which rectangles orthogonal to each other are alternately arranged and fine dots are arranged along four sides of each rectangle is also preferable.

At the joining portion for joining the sheet-like elastic body and the nonwoven fabric, the extensibility of these materials is greatly reduced, and the material is made substantially inextensible. Therefore, FIG.
When the connecting portion row 30 is provided so as to extend in a direction substantially perpendicular to the easy extension direction as shown in FIG. 8, the extensibility in the easy extension direction hardly changes. Even if the material has great extensibility in this direction, its extensibility is greatly reduced. Therefore, the composite elastic body shown in FIG. 18 hardly extends in the length direction of the connecting portion row 30.

For example, even when the elastic sheet and the nonwoven fabric are joined by hydroentanglement, the extensibility at the joint is greatly reduced. That is, in the composite elastic body of the present invention, the elasticity is almost lost in the portion where the sheet-like elastic body and the nonwoven fabric are strongly entangled with each other.

However, in the direction perpendicular to the connecting portion row 30, in the process of extending the composite elastic body in the easy extension direction, the composite elastic body is freely extended until it reaches the extension limit of the nonwoven fabric.
When the tension is released at this limit, both the sheet-like elastic body and the nonwoven fabric return to their original lengths. However, when the non-woven fabric is further stretched beyond its elongation limit, there is no change in the sheet-like elastic body, whose elastic limit is extremely high, but as a result of the elongation of the non-woven fabric, its elastic recovery property is lost, and then the tension is released. However, the sheet-like elastic body is restored to its original length, but the nonwoven fabric remains extended. For this reason, when the entire composite elastic body is restored to the original length, the nonwoven fabric becomes longer than the sheet-like elastic body, and the nonwoven fabric sags between the adjacent connecting portion rows.

In the state where the nonwoven fabric is stretched in this manner, when the composite elastic body is again stretched in the easy stretching direction, the tensile force required when the nonwoven fabric is first stretched beyond the extension limit of the nonwoven fabric is significantly larger than the tensile force required when the composite elastic body is stretched beyond the stretching limit. It can be extended with a small force. This is the elongation activation described above.

As can be understood from the above description, the elongation of the composite elastic body in the direction in which the connecting portion or the connecting portion row extends is significantly smaller than that in the direction of easy extension. This means
A composite elastic body composed of a sheet-like elastic body and a non-woven fabric, which has large extensibility in all directions, can be extended only in a desired direction by newly providing a joint or a row of joints under specific conditions. It means that it can be limited.

FIG. 23 shows a substantially rectangular composite elastic body obtained by combining a sheet-like elastic body having a large extensibility in both the x and y directions with a nonwoven fabric. In this composite elastic body, in FIG. 24, except for the central region (A), in the regions (B) and C having appropriate widths extending along four sides thereof, linear couplings extending in a direction substantially orthogonal to each side are shown. The part 3 is newly provided. In this composite elastic body, in the area (A) where the coupling portion 3 is not provided, the composite elastic body can extend in any direction, but in the area (B), it has extensibility only in the x direction.
In addition, the region C has extensibility only in the y direction. FIG. 2
As shown in FIG. 5, in a region (B) extending along two sides located at both ends in the y direction and a region (D) extending in the y direction at the center in the x direction, a plurality of linear couplings extending in this direction are provided. In a region (E) extending along two sides located at both ends in the y direction, when a linear connecting portion 3 inclined at an angle of about 45 ° with respect to this side is provided, In regions other than the region (D), large extensibility is exhibited in the x direction, but in the region (E), extensibility is exhibited only in the oblique direction.

As shown in FIGS. 24 and 25, a composite elastic body having a stretchable direction specified by adding a linear connecting portion to the composite elastic body is, for example, a backsheet having diaper elasticity. When used as a topsheet, shape follow-up by B part as elastic body of waist part, C part and E part as elastic body surrounding leg hole, and A part corresponding to whole expansion and contraction It can contribute to the design of products with excellent characteristics.

FIG. 26 shows a composite elastic body 100 according to another embodiment of the present invention. Although this composite elastic body has extensibility in only one direction, by performing a further partial thermocompression treatment on the composite elastic body, a new thermocompression bonding is performed in the first region 110 located at the center. Since it has not been subjected to the treatment, it has the large extensibility of the original composite elastic body, and in the second regions 111 located at both ends, it has almost no extensibility due to the new thermocompression bonding treatment. The treatment enhances the bond strength. FIG. 2
7, three strip-shaped regions 111 having small extensibility are arranged at predetermined intervals. Further, in FIG. 28, regions 110 with high extensibility are provided on both sides of the band-like region 111 with low extensibility. In any case, the portion having a small degree of expansion and contraction is a portion subjected to a new thermocompression treatment.
The sheet-like elastic body and the nonwoven fabric in this example are made of a material that is easily melted by heating. A nonwoven fabric meeting such a purpose is, for example, a conjugate resin web composed of a combination of polyester and polyethylene, made of polyethylene as a sheath and polyester as a core. E. FIG. B. S. (Styrene, ethylene butadiene reslene block copolymer) is combined with the film. The composite elastic body thus obtained is
It is extremely excellent in ultrasonic sealability and heat sealability, and exhibits excellent performance in high-speed manufacturing in a process.

FIG. 29 shows a composite elastic body formed by laminating a sheet-like elastic body made of an SIS-based film and a non-woven fabric made of hydroentangled PET fibers and performing partial thermocompression bonding. It is a graph which shows the result of having measured the relationship between the processing temperature at the time of thermocompression bonding, and tensile strength at the time of performing a press bonding process. In this graph, reference symbol T1 denotes the SIS constituting the sheet-like elastic body.
, T2 indicates the melting start temperature of PET constituting the nonwoven fabric. As can be seen from FIG.
At T1 or less, thermocompression bonding between the sheet-like elastic body and the nonwoven fabric is scarcely performed, and there is elongation recovery but low tensile strength. However, when thermocompression bonding is performed in the temperature range between T1 and T2, at least a part of the sheet-like elastic body is melted and bonded to the nonwoven fabric, so that the extensibility recoverability is lost, but the tensile strength is low. Significantly improved. Further, when thermocompression bonding is performed at a temperature exceeding T2, both the sheet-like elastic body and the nonwoven fabric are fused, and have almost no extensibility in any direction.

Referring again to FIGS. 26 to 28, the composite elastic body having such characteristics can be obtained by heat-treating the composite elastic body once formed as described above. The sheet-shaped elastic body and the nonwoven fabric directly superimposed so that
It can be configured by bonding by thermal fusion between 10 and region 111 under different conditions. In other words, the region 110 having a high extensibility is subjected to partial thermocompression bonding at a temperature between T1 and T2, and
By performing the entire thermocompression bonding at the above temperature, a composite nonwoven fabric having a desired extensibility can be formed. In this composite nonwoven fabric, the extensibility of the region 110 having high extensibility is limited or restricted by the small extensibility of the region 111, and therefore has a large extensibility in a predetermined elongation direction, but has an extensibility in other directions. It has the property of being extremely small. If the entire thermocompression bonding is performed at a temperature of T2 or more, this portion becomes fragile.

A composite nonwoven fabric in which a region having a large extensibility and a region having a small extensibility are mixed in a desired pattern as described above can be applied to various uses. An example is shown in FIG.
As shown in FIG. 6, the composite nonwoven fabric in which the small extensibility regions 111 are formed on both sides of the large extensibility region 110 can be applied to a tapeless (pants-type) absorbent product.

In the absorbent product shown in FIG. 30, that is, the tapeless diaper, a main body 121 having a structure in which an absorbent is housed between a liquid-permeable top sheet and a liquid-impermeable back sheet is substantially provided at the center thereof. As shown in FIG.
6. Side panel 12 made of composite elastic body 100 shown in FIG.
It has a structure connected by three. This composite nonwoven fabric 100
Are connected to the main body 121 at regions of low extensibility 111 located at both ends thereof, and regions 1 of high extensibility at the central portion
At 10 it is not combined. Therefore, the large extensibility of the region 110 of the composite nonwoven fabric 100 is not hindered, and functions as a side panel, and is firmly bonded to the main body 121 in the regions 11 having high strength at both ends.

FIG. 31 shows a tape-type diaper having a structure in which the side band 124 made of the composite elastic body 100 shown in FIG. The side band 124 is coupled to the main body 121 at a small extensibility region 111 at one end of the composite elastic body 100, and is detachably attached to a coupling region 125 provided on the main body 121 at the other small extensibility region 111 at the other end. A fastener 126 to be connected is attached. The diaper having such a configuration can be easily attached / detached by removing the fastener 126, and the waist of the diaper closely adheres to the waist of the wearer due to the large extensibility of the region 110 as in the case of FIG.

The composite elastic body 100 may be pre-stretched before being applied to the diaper main body 121, or after being applied to the main body 121 by a pre-stretching device incorporated in a diaper production line. It may be pre-stretched.

Hereinafter, examples of the present invention will be described.

[0091]

【Example】

(Example 1) <Production of extensible nonwoven fabric> Polyester fiber (1.5 dx
35 m / m) 50 parts of a polyester-based core-score type heat-soluble conjugate fiber melty (2 d × 51 m / m)
m) 50 parts were mixed and 30 g / m2 using a roller card.
A card web having a basis weight of ² was prepared. The MD / CD direction difference of this web is about MD / CD = 3.5 in intensity ratio.
Met. This web was guided on a net conveyor provided with two types of high-pressure water jets, and subjected to a water entanglement treatment at a speed of about 30 m / min on a net provided with a dewatering zone. The hydroentanglement conditions were as follows.

First processing zone No. of nozzle lines 2 sets • Constituent nozzle diameter: 0.15 mm Interval: 0.6 mm • Water pressure 50 kg / cm ² Second processing zone No. of nozzle lines 2 sets • Constituent nozzle diameter: 0.20 mm Interval: 1.00 mm Water pressure 70 kg / cm ² The web after the entanglement treatment was dewatered and then introduced into a hot air dryer and dried. The maximum temperature was 130 ° C. After passing through the dryer, the film was stretched by about 30% (1.3 times) in a heated state, and then cooled and wound.

The nonwoven fabric thus obtained has a basis weight of 22 g /
m ² , MD / CD = 8. The elongation at break in the C and D directions was about 280%.

<Production of Sheet Elastic Body> Preparation of Compound SEBS resin (trade name "Septon # 800" manufactured by Kuraray)
7 ") 65 parts, EVA resin (trade name" Evaflex P-1907 "manufactured by Mitsui Dupont) 35 parts, and antioxidant (trade name" Luganox 1010 "manufactured by DuPont Mitsui)
Was added and mixed, and the mixture was melt-pelletized to prepare a compound. 230 ° C, 2.1
The MFR (g / 10 min) at a pressure of 6 kg was 7.8.

Molding and Winding of Elastic Film A 20 μm film was molded from the above compound using a die extruder. Since this film has a strong self-adhesive property and cannot be separated from each other if it is wound as it is, the extensible nonwoven fabric was inserted and layered before winding and wound up.

<Production of Single-Sided Nonwoven Fabric> The sheet obtained by laminating the above nonwoven fabric and elastic film is in a temporary bonding state due to the self-adhesion of the film. Guide the sheet in this temporarily joined state onto a 40 mesh plastic net,
A net, an elastic film, and an extensible film woven fabric are stacked in this order, and passed through a pressure device composed of a combination of a heated grit roll and a flat roll to partially fuse and bond the elastic film and the extensible nonwoven fabric. Was. Heating was performed from the nonwoven fabric side. The outline of the heating and pressurizing device is as follows.

Upper roll (grid roll) -Height of peak: 1.0 mm-Width of apex: 1.5 mm-Grid spacing: 3.0 mm-Heating of internal heating medium-Processing temperature: 130 ° C-Surface treatment: chrome plating Processing lower roll (flat roll)・ Surface processing: chrome plating processing ・ Processing temperature: 35 ° C. Pressure: 40 kg / cm ² Winding speed: 20 n / min In this way, the composite elastic body which is a bonded body of the film and the nonwoven fabric is obtained. Obtained. The joining pattern of the composite elastic body had a pattern as shown in FIG.

<Production of double-sided non-woven fabric joined body> The two single-sided non-woven fabric joined together so that their film surfaces face each other to produce a composite elastic body having a non-woven fabric on both sides.

In the case of this example, since the self-adhesion of the films is extremely large, the films are easily joined by overlapping and pressing. In this example, when two flat rolls heated to 80 ° C. were passed, a composite elastic body having a joint structure as shown in FIG. 15 having nonwoven fabrics on both sides joined and integrated was obtained.

<Measurement of SS Curve of Composite Elastic Body> Using the above composite elastic body, an SS curve up to complete fracture was measured. The measurement result is shown in FIG. FIG.
Also, a stress drop point of about 230% based on the breakage of the nonwoven fabric portion and a stress drop point of about 420% based on the breakage of the film are observed.

<Measurement of SS Curve of Stretched Product> Using the composite elastic body, 75%, 100%, 15%
Three types of samples that were subjected to a 0% stretching treatment were prepared. For each of the materials, the SS curve up to the fracture was measured, and the results are shown in FIGS. In any case, the existence of the first stress falling point and the second stress falling point is more clearly observed.

This is presumed to be due to the homogenization of the structure due to the removal of the strain by the stretching treatment.

More importantly, such a stretching treatment greatly reduces the elongation stress in the range of the stretching treatment. This is based on elongation activation, which is an important point of the present invention. Due to such an effect, the stretched composite elastic body has four stretch characteristic regions as shown in FIG.

(Example 2) <Production of extensible nonwoven fabric> Polyester fiber (1/5 d ×
35 parts of polyester fiber (2d × 51m)
m) 50 parts were mixed and 25 g /
An m ² parallel card web was prepared.

The direction difference between the MD and the CD of this web is MD
/ CD = 7. This web is guided on a perforated suction cylinder provided with three nozzles and a dewatering zone,
After water saturation, degassing, and dehydration, the mixture was passed through a nozzle at a speed of 30 m / min, and entangled by a water flow.

First nozzle: 0.12 mmφ × 0.4 mm interval Water pressure 30 kg / cm ² Second nozzle: 0.12 mmφ × 0.4 mm interval Water pressure 50 kg / cm ² Third nozzle: 0.20 mmφ × 1.5 mm interval Water pressure The above entangled web of 60 kg / cm ² was dried and heat-treated to obtain a web-like nonwoven fabric of 30 g / m ² .

The SS curve of this nonwoven fabric up to the first stress drop point in the CD direction was as shown in FIG.

<Preparation of Sheet Elastic Body> A 25 μm film is prepared by extruding a blend resin composed of EMA / EPDM polyolefin elastomer as a sheet elastic body. S- in the CD direction of the sheet-like elastic body
The S curve was as shown in B of FIG.

<One-sided bonded body> The nonwoven fabric and the sheet-like elastic body are superimposed on each other, and placed on a 60-mesh PFT net so that the sheet-like elastic body is on the PFT net side. 110 with
A composite elastic body was obtained by pressing a heating roll at a temperature of 10 ° C. at a linear pressure of 10 kg / cm so that a flat roll was in contact with the net side.

The SS curve of the composite elastic body up to the first stress drop point in the CD direction was as shown in FIG. 32C.

The results of a three-cycle test in which the composite elastic body was repeatedly stretched to 150% and opened repeatedly were as shown in FIG. 7 and had a recovery rate of 75%.

<Both-side joined body> The two single-sided joined bodies were overlaid on the film side, and a flat heating roller at 80 ° C was subjected to a pressure treatment at a linear pressure of 20 kg / cm and a speed of 10 m / min. A stable bonding state was shown. The position of the junction was shifted so that it did not overlap on the front and back. The SS curve of this composite nonwoven fabric up to the first stress drop point in the CD direction was as shown in FIG. 32D.

The results of a three-cycle test in which the composite elastic body was repeatedly stretched to 150% and opened repeatedly were as shown in FIG. 8 and had a recovery rate of 75%.

(Example 3) <One-sided joint of SEBS film and nonwoven fabric> SEB
A composition mainly composed of a resin obtained by blending 25 parts of EVA with S75 parts was extruded to prepare an elastic film having a thickness of 25 μm. The films had a property of self-adhesion easily only by pressure bonding at room temperature.

On one side of this film, a very small amount (about 0.4
g / m ² ) of rubber-based hot melt was sprayed, and the same nonwoven fabric as that used in Example 1 was bonded by pressure bonding over the entire surface.

<Both-side bonded body> Two composites in which a nonwoven fabric was bonded to one side of the above SEBS-based film were prepared, and they were overlapped so that the self-adhesive film side faced up to about 4
When the film was passed between a pair of flat rolls at a linear pressure of 20 kg / cm ² at 0 ° C., a bonded body having non-woven fabrics on both sides where the films were bonded to each other stably was obtained.

The single-sided and double-sided joints configured as described above had the same elongation recovery characteristics as in Example 1.

Example 4 Polypropylene fiber (2d ×
30 parts of polyester fiber (2d x 57m)
m) 30 parts were mixed and 20 g /
to prepare a parallel web of the m ² L This web is MD /
CD = 8.0.

This web was prepared using 40% of SIS as a main component.
g / m ² of a melt-blown non-woven fabric (manufactured by Kuraray Co., Ltd.) on a net conveyor, and overlaid on a nert provided with a plurality of nozzles and a dewatering zone, the stepwise conditions shown in Table 1 below To perform confounding processing.

[0120]

[Table 1] Obtained complex Stage stage Nozzle condition Pressure condition Surface condition ────────── ──────── ───── ──────── 1st stage (preliminary treatment) 0.12mmφ × 0.6mm 30kg / cm ² − 2nd stage (preliminary treatment) 0.12mmφ × 0.6mm 50kg / cm ² Fig. 33 3rd stage (partial confounding) 0.20mmφ × 4.0mm 100kg / cm ² Fig. 34 4th stage (partial non-stretching 0.15mmφ x 0.6mm 70kg / cm ² Fig. 35 conversion process) The surface structure of the composite obtained at each stage is as shown in Fig. 33-Fig. Was. The entangled elastic body obtained in the final stage has a strip-shaped easily stretchable portion 131 and a hardly stretchable portion 132.
In the 50% 3-cycle test, as shown in FIG.
The elongation recovery rate was 0%. On the other hand, the difficult extension portion 132
It showed almost no elasticity, its SS curve was as shown in FIG. 37, and its breaking strength was about 1.2 kg / 50 mm.

[0121] was prepared (Example 5) <extensible nonwoven production> spunbond made of polyester sheath-core type heat easily soluble conjugate fibers (manufactured by Unitika Ltd. trade name "ELEVES") 30 g / m ^2. This spunbond had an MD / CD of 3 and a breaking elongation of 700%.

This non-woven fabric was subjected to a tunnel entrance speed of 20
m / min, a tunnel exit speed of 30 m / min, a hot air tunnel at a temperature of 130 ° C.
The film was hot stretched to about 50% (1.5 times), and then cooled and wound up.

The stretched spunbond thus obtained has a basis weight of 23 g / m ² and a direction difference of MD / CD = 7,
The elongation at break in the direction increased to 180%.

<Production of Elastic Compound> SEPS
(Kuraray product name "Septon # 4033") 45 parts,
30 parts of LDPE (product name “LM31” manufactured by Unitika Ltd.)
Process oil (product name “Diana PW-
380 ") was mixed with 25 parts to obtain a pelletized compound. 230 ° C, 2.16k of this compound
The MFR under g pressure (g / 10 min) was 14.

<Formation of Elastic Film and Bonding of Extensible Nonwoven Fabric>
Was formed. Before the film cools,
After being overlapped with the above-mentioned extensible spun bond and passed through a pair of flat press rolls, it was further passed through a pair of heat embossing rolls described below.

The heat embossing treatment was performed from the nonwoven fabric side.

Upper roll (embossed protrusion roll) , peak height: 0.8 mm, pattern: pattern shown in FIG. 20, grid interval: 3.0 mm, internal heating medium heating, processing temperature: 120 ° C., surface processing: chrome Plating lower roll (flat roll)・ Surface processing: chrome plating processing ・ Temperature: normal temperature pressure: 30 kg / cm ² Thus, a composite elastic body of a film and an extensible nonwoven fabric was obtained by an online process. The obtained composite elastic body exhibited excellent stretch characteristics similar to those of the above-described examples.

[0128]

As described above, in the process of elongation from the unstretched state to the breaking limit, the stress of the composite elastic body of the present invention gradually increases as it approaches the breaking limit of the nonwoven fabric, The stress reaches its maximum just before the breaking limit. Then, when the elongation is further continued, the stress reaches a first stress drop point caused by the breakage of the nonwoven fabric, and the stress drops sharply. Thereafter, the elastic body is stretched to a breakage limit of the elastic body with a small stress. In addition, no matter how far the stage is extended, the original length can be restored by releasing the tension due to the elasticity of the elastic body. Due to such elongation properties, the composite elastic body of the present invention is excellent in elasticity recovery property, and also excellent in surface feel, and is particularly used in a portion directly in contact with the skin, for example, a sleeve of a medical gown. It can be advantageously used for applications such as waist and crotch elastics of sanitary articles.

[Brief description of the drawings]

FIG. 1 is a graph showing an SS curve when a composite elastic body of the present invention, a nonwoven fabric constituting the composite elastic body, and the elastic body are stretched to break.

FIG. 2 is a graph showing an SS curve when the composite elastic body of the present invention is pre-stretched and then stretched to break.

FIG. 3 is a graph showing an SS curve when the composite elastic body of the present invention is stretched and recovered to 75%.

FIG. 4 is a graph showing an SS curve when the composite elastic body of the present invention is stretched and recovered to 100%.

FIG. 5 is a graph showing an SS curve when the composite elastic body of the present invention is stretched and recovered to 150%.

FIG. 6 is a graph showing four different stretch characteristic regions formed when the composite elastic body of the present invention is stretched and recovered to 150%.

FIG. 7 is a graph showing an SS curve of the composite elastic body according to the present invention.

FIG. 8 is a graph showing an SS curve of another composite elastic body according to the present invention.

FIG. 9 is a graph showing an SS curve when the composite elastic body of the present invention is stretched and recovered at a certain ratio.

FIG. 10 is a graph showing an SS curve when the composite elastic body of the present invention is stretched and recovered at a ratio different from that in FIG. 3;

FIG. 11 is a graph showing an SS curve when the composite elastic body of the present invention is stretched and recovered at a ratio different from that in FIG. 3;

FIG. 12 is a graph showing an SS curve when the composite elastic body of the present invention is stretched and recovered at a ratio different from that in FIG. 3;

FIG. 13 is a graph showing an SS curve when the composite elastic body of the present invention is stretched and recovered at a ratio different from that in FIG. 3;

FIG. 14 is a graph showing an SS curve in the MD and CD directions of the hydroentangled nonwoven fabric used in the present invention.

FIG. 15 is a schematic sectional view showing a first arrangement example of the sheet-like elastic body and the nonwoven fabric of the present invention.

FIG. 16 is a schematic sectional view showing a second arrangement example of the sheet-like elastic body and the nonwoven fabric of the present invention.

FIG. 17 is a schematic sectional view showing a third arrangement example of the sheet-like elastic body and the nonwoven fabric of the present invention.

FIG. 18 is a plan view showing a first example of a discontinuous joint pattern applied to the composite elastic body of the present invention.

FIG. 19 is a plan view showing a second example of a discontinuous joint pattern applied to the composite elastic body of the present invention.

FIG. 20 is a plan view showing a third example of a discontinuous joint pattern applied to the composite elastic body of the present invention.

FIG. 21 is a plan view showing a fourth example of a discontinuous joint pattern applied to the composite elastic body of the present invention.

FIG. 22 is a plan view showing a fifth example of a discontinuous joint pattern applied to the composite elastic body of the present invention.

FIG. 23 is a plan view showing the direction of elongation of the composite elastic body of the present invention.

FIG. 24 is a plan view showing a first example of the arrangement of discontinuous joint portions applied to the composite elastic body of the present invention.

FIG. 25 is a plan view showing a second example of the arrangement of discontinuous joints applied to the composite elastic body of the present invention.

FIG. 26 is a plan view showing an example of the arrangement of discontinuous joints applied to the composite elastic body of the present invention.

FIG. 27 is a plan view showing another arrangement example of the discontinuous joint applied to the composite elastic body of the present invention.

FIG. 28 is a plan view showing still another arrangement example of the discontinuous joint applied to the composite elastic body of the present invention.

FIG. 29 is a graph showing the results of measuring the relationship between the processing temperature during thermocompression bonding and the tensile strength of the composite nonwoven fabric of the present invention.

30 is a perspective view showing an absorbent product using the composite elastic body shown in FIG. 13 for a side panel.

FIG. 31 is a perspective view showing an absorbent product using the composite elastic body shown in FIG. 13 for a side panel.

FIG. 32 shows a composite elastic body obtained in Example 1 of the present invention and C of a sheet-like elastic body and a nonwoven fabric used therein.
4 is a graph showing an SS curve in a D direction.

FIG. 33 is an explanatory view showing the surface state of the composite elastic body after the second-stage processing in Example 3 of the present invention.

FIG. 34 is an explanatory diagram showing the surface state of the composite elastic body after the third-stage processing in Example 3 of the present invention.

FIG. 35 is an explanatory view showing the surface state of the composite elastic body after the fourth-stage processing in Example 3 of the present invention.

FIG. 36 is a graph showing an SS curve by a 150% three-cycle test performed using only the elongated portion of the composite elastic body obtained in Example 3 of the present invention.

FIG. 37 is a graph showing an SS curve by a 150% three-cycle test performed using only the hardly stretched portion of the composite elastic body obtained in Example 3 of the present invention.

[Explanation of symbols]

 Reference Signs List 3 joining part 4 hot press 11, 12 sheet-like elastic body 21, 22 nonwoven fabric 30 joining part row 31 joining part 100 composite elastic body 110 first region 111 second region 121 main body 122 leg hole 123 side panel 124 side band 125 Binding region 126 Fastener 131 Easy-to-extensible part 132 Hard-to-extensible part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI A61F 13/494 B32B 27/12 13/56 A41B 13/02 H B29C 65/02 KB32B 5/04 27/12 (58) Survey Field (Int.Cl. ⁷ , DB name) D04H 1/00-18/00 B32B 1/00-35/00

Claims (29)

(57) [Claims] 1. A nonwoven fabric having extensibility in at least one axial direction and having an elongation at break of 100% or more in this elongation direction, and a sheet having an elastic recovery rate of at least 60% and an elongation at break of 200% or more. A composite elastic body having a shape elastic body,
The nonwoven fabric and the elastic body is coupled to one another in discrete number of attachment portions with respect to the extending direction of the nonwoven fabric, elongation
Pre-stretching for activation is performed at 90% or less of breaking elongation.
The stress at 30% elongation obtained by performing in the range
Easily extensible region (I) of not more than 500 g / 5 cm
And the stress increase region (II) that acts as extension resistance,
Transition region from 1 stress drop point to 2nd extensibility region
(III) and from this transition region to the second point of stress drop
A composite elastic body having a second extensible region (IV) . 2. The composite elastic body according to claim 1 , wherein a difference between the first stress drop point and the second stress drop point is 50% or more. 3. The elongation at break of the nonwoven fabric is 150% or more,
The composite elastic body according to claim 1 or 2 , which is preferably at least 200%. 4. When the SS curve is measured in an unstretched state, the stress at 30% elongation is 1000 g or less, the stress at 100% elongation is 400 g or more, and the breaking strength is 400 g per 5 cm width. As described above, when the elongation at break is 200% or more, and the SS curve is measured in an elongation state of 200% or less, the stress at 30% elongation is 500 g or less as a measurement value per 5 cm width. , at 100% elongation stress is 100g or more, has a value, and further at 150% elongation, when repeatedly measured three times a recovery claim its recovery rate is 60% or more
The composite elastic body according to any one of Items 1 to 3 . 5. When the SS curve is measured in an unstretched state, a stress per 30 cm elongation is 800 g or less, a stress at 100% elongation is 600 g or more, and a breaking strength is 600 g per 5 cm width. As described above, when the elongation at break is 200% or more, and the SS curve is measured in an elongation state of 200% or less, the stress at 30% elongation is 300 g or less as a measurement value per 5 cm width. , at 100% elongation stress is 200g or more, has a value, and further at 150% elongation, when repeatedly measured three times a recovery claim its recovery rate is 70% or more
The composite elastic body according to any one of Items 1 to 3 . Wherein said nonwoven fabric, tow extended and broadened nonwoven, stretching parallelism spunbonded nonwoven or composite elastic material of any one of claims 1 to 5 is stretched parallelized meltblown nonwoven fabric. Wherein said nonwoven fabric is a nonwoven fabric obtained by hydroentangling, and is characterized in that with a two-stage extensibility of different stress levels according to any one of claims 1 to 6 Composite elastic body. 8. The nonwoven fabric according to claim 1, wherein the second stage has an extension of 15
The composite elastic body according to claim 7 , wherein the composite elastic body occurs after 0% elongation. 9. The nonwoven fabric has a structure in which the orientation of the fiber in the MD direction is enhanced by a hot drawing treatment in the MD direction.
The extensibility in the CD direction is enhanced .
9. The composite elastic body according to any one of 8 . Wherein said nonwoven fabric, claim by increasing the orientation of the CD direction of the fibers by the widening process to the CD direction, in which extensibility in the MD direction is enhanced
10. The composite elastic body according to any one of 1 to 9 . 11. The composite elastic body according to claim 1 , wherein the nonwoven fabric is made of a heat-meltable material. 12. The method of claim 11, wherein the sheet-like elastic body, according to claim 1 to 1, characterized in that it is composed of a readily heat fusible material
2. The composite elastic body according to any one of 1. 13. The elastic body may be urethane, rubber latex foam, isoprene, butadiene synthetic rubber film, SIS, SEBS or SEPS styrene elastomer film, EVA, EMA, or
Is a polyolefin-based elastomer film of EPDM ,
Or polyurethane, SIS claims 1 to 12 or a Mel <br/> Toblerone elastomer nonwoven SEBS,
The composite elastic body according to any one of the above. 14. The composite elastic body according to claim 1 , wherein the nonwoven fabric is bonded to both sides of the elastic body. 15. The two elastic bodies nonwoven on one surface each of which is coupled, claims having a four-layer structure in which the nonwoven fabric is not bonded surface is bonded by superposing so as to face the elastic body 14. The composite elastic body according to any one of 1 to 13 . 16. The composite elastic body according to claim 14 , wherein one of the nonwoven fabrics is hydrophilic and the other nonwoven fabric is hydrophobic. 17. The nonwoven fabric and the elastic body, claim are joined by spot arranged randomly 1-16
The composite elastic body according to any one of the above. 18. A bonding portion between the sheet-like elastic body and the first non-woven fabric, wherein a first non-woven fabric is arranged on one surface of the elastic body and a second non-woven fabric is arranged on the other surface. 18. The composite elastic body according to claim 17 , wherein the joint part between the sheet-like elastic body and the second nonwoven fabric is distributed to a position that does not largely overlap. Coupling portion 19. coupling the said sheet-like elastic member nonwoven, characterized in that it extends in a band shape in a direction substantially orthogonal to the extending direction of the nonwoven fabric according
Item 17. The composite elastic body according to any one of Items 1 to 16 . Claims 20. A coupling unit for coupling the said sheet-like elastic member nonwoven, characterized in that to form a coupling portion rows extending in a direction substantially orthogonal to the extending direction of the nonwoven fabric 17. The composite elastic body according to any one of 1 to 16 . 21. The sheet-like elastic body and the nonwoven fabric are bonded by thermocompression bonding only at a predetermined portion at a temperature equal to or higher than the melting start temperature of the sheet-like elastic body and equal to or lower than the melting start temperature of the nonwoven fabric. Claims wherein by forming a portion having lower extensibility than other portions, directionality is given to the extensibility.
21. The composite elastic body according to 19 or 20 . 22. The composite elastic body according to claim 21 , wherein the low-extensibility portion is provided in a belt shape. 23. A highly extensible region formed by partially joining the sheet-like elastic body and the nonwoven fabric, and the sheet-like elastic body and the nonwoven fabric are joined substantially over the entire surface. It constructed by, according to any one of claims 1 to 22, characterized in that it comprises a comparison to extension of the very small low-stretch region <br/> and the high stretch region Composite elastic body. 24. The composite elastic body according to claim 23 , wherein said low-extensibility region is formed in a plurality of strip-shaped connecting portions extending in parallel with each other. 25. The composite elastic body according to claim 23 , wherein the low elongation regions are formed at both ends. 26. An absorbent body provided with an absorbent body therein capable of covering the waist of a wearer, wherein the composite elastic body according to claim 25 is attached to the absorbent body at a low extension portion at one end thereof. An absorbent product, wherein the binding device is attached to the low extension portion at the other end. 27. An absorbent body having an absorbent body therein capable of covering the waist of a wearer, wherein the composite elastic body according to claim 25 forms a side panel. Product. 28. It has extensibility in at least one axial direction,
A nonwoven fabric having a breaking elongation of 100% or more in this elongation direction, an elastic recovery rate of 60% or more, and a breaking elongation of 200%
The step of superimposing the sheet-like elastic body as described above, and the step of bonding the nonwoven fabric and the elastic body to each other at a number of discontinuous joints with respect to the elongation direction of the nonwoven fabric,
To the resulting elongation direction of the composite the non-woven fabric, characterized in that it comprises a step of prestretching in lower elongation than the breaking limit of the non-woven fabric, the stress at 30% elongation 50
An extensible region (I) such as 0 g / 5 cm or less;
The stress increasing region (II) acting as elongation resistance and the first
Transition region from the stress drop point to the second extensibility region (II
I) and from this transition area to the second stress drop point
A method for producing a composite elastic body having a second extensible region (IV) . 29. The elongation amount in the preliminary elongation step,
The method according to claim 28 , wherein the amount of elongation at break elongation of the nonwoven fabric is 40% to 80%.