JP4774900B2 - Elastic nonwoven fabric and article using the same - Google Patents

Description

  The present invention relates to a stretchable nonwoven fabric and an article using the same. More specifically, the present invention relates to a stretchable nonwoven fabric which is rich in stretch recovery and excellent in texture and formability and an article using the stretchable nonwoven fabric.

  Spunbond non-woven fabrics composed of long fibers have high non-woven strength and excellent productivity, so the price can be reduced, and a wide range of applications such as sanitary materials, medical materials, architecture, civil engineering, agricultural materials, etc. It is used for. In recent years, as the application spreads, the required performance required for spunbonded non-woven fabrics has been diversified.

  Conventionally, spunbonded nonwoven fabrics have high nonwoven fabric strength, but the filament yarns used are non-crimped, and therefore have problems such as poor bulkiness and low texture. In addition, although spunbonded nonwoven fabric has extensibility, since it is inferior in stretchability, so-called stretch recovery properties, various production methods for imparting bulkiness and stretchability to these spunbonded nonwoven fabrics have been proposed. .

  As a manufacturing method for imparting crimp to the long fibers that are constituent fibers and imparting bulkiness to the spunbonded nonwoven fabric, for example, a high molecular weight polymer is melt-spun from a spinneret having a deformed spinning hole, and then a high-speed air current is used. A method for producing a spunbond nonwoven fabric is proposed in which one side surface of this long fiber group is subjected to cooling treatment when drawn and solidified to cause crimping in the long fiber group, and then the long fiber group is laminated and integrated. (For example, refer to Patent Document 1).

  The spunbonded nonwoven fabric obtained by this method is bulky and flexible as compared with non-crimped spunbonded nonwoven fabrics because the volume of the long fiber spacing increases due to crimping of the long fibers. However, since the crimped long fibers adjacent to each other at the time of opening are entangled with each other and the opening is poor, it has a disadvantage that the formation is not uniform, and it is obtained by thermocompression bonding with an embossing roll. Since the thickness of the resulting nonwoven fabric is limited by the height of the embossed convex portion, the bulkiness is not sufficient.

  As a method to compensate for these drawbacks, after laminating a continuous polyolefin fiber with a low thermal shrinkage on both sides of a continuous polyolefin fiber or polyester with a high thermal shrinkage rate, it is integrated by thermocompression bonding. There is proposed a method for producing a bulky and flexible spunbonded nonwoven fabric which is then heat-treated and then thermally contracted (see, for example, Patent Document 2).

In this method, since the continuous long fibers are non-crimped, the spreadability is good, and the non-woven fabric is a bulky non-woven fabric whose thickness is not limited by the height of the embossed convex portion because it is heat-treated and contracted after thermocompression bonding. Was obtained. However, since the long fibers constituting the resin are single-component resins made of polyolefin or polyester, the nonwoven fabric contracted by heat treatment is a non-crimped fiber in which the fiber itself contracts and has an extensibility. Even if it exists, there exists a fault that it is inferior to elongation recovery property. In addition, when fixing between laminates by thermocompression bonding, the continuous long fibers having large thermal shrinkage are processed at a temperature at which they do not shrink, so the processing range is narrow and adhesion between the laminates is insufficient.
Japanese Patent Laid-Open No. 1-148862 JP-A-8-176947

  Under the circumstances described above, for example, there is a demand for a stretchable nonwoven fabric that has an excellent texture and high stretch recovery, preferably excellent in productivity, and can be reduced in cost, and an article using the stretchable nonwoven fabric. Yes.

The present inventors have intensively studied to solve the above problems. As a result, by adopting the following configuration, the expected purpose is achieved, and the present invention has been completed.
The present invention has the following configuration.
[1] A stretchable nonwoven fabric obtained by thermocompression bonding of a web composed of a composite filament obtained by a spunbond method using an embossing roll, and the composite filament is composed of a low melting point resin and a high melting point resin. The low-melting point resin contains polyethylene, the high-melting point resin contains polyester, and the stretchable nonwoven fabric has a portion where 2 to 100 composite filaments are fused in parallel (hereinafter referred to as a “converging portion”). And a portion where the composite filament is not fused (hereinafter referred to as “non-focusing portion”), and the composite filament of the focusing portion and the non-focusing portion forms a three-dimensional crimp. An elastic nonwoven fabric characterized by that.
[2] The stretchable nonwoven fabric according to the above [1], wherein the low melting point resin is polyethylene and the high melting point resin is polyester.
[3] The stretchable nonwoven fabric according to the above [1] or [2], wherein the melting point of the high melting point resin is higher by 5 ° C. or more than the melting point of the low melting point resin.
[4] The polyethylene is at least one selected from the group of crystalline polyethylene having a density of 0.910 to 0.960 g / cm ³ , comprising high density polyethylene, low density polyethylene, and linear low density polyethylene, and the polyester is The stretchable nonwoven fabric according to any one of [1] to [3], which is polyethylene terephthalate or polybutylene terephthalate.
[5] The stretchable nonwoven fabric according to any one of [1] to [4], wherein the stretch recovery rate at 20% stretch in the width direction of the stretchable nonwoven fabric is 90% or more.
[6] The stretchable nonwoven fabric according to any one of the above [1] to [5], wherein the ratio between the breaking strength in the longitudinal direction of the stretchable nonwoven fabric and the 5% elongation strength is 1.5 or less.
[7] A composite nonwoven fabric obtained by laminating the stretchable nonwoven fabric according to any one of [1] to [6] and another sheet.
[8] A wiper using the stretchable nonwoven fabric according to any one of [1] to [6] or the composite nonwoven fabric according to [7].
[9] A packaging material using the stretchable nonwoven fabric according to any one of [1] to [6] or the composite nonwoven fabric according to [7].
[10] A cushioning material using the stretchable nonwoven fabric according to any one of [1] to [6] or the composite nonwoven fabric according to [7].
[11] A medical material for trauma using the stretchable nonwoven fabric according to any one of [1] to [6] or the composite nonwoven fabric according to [7].

  The stretchable nonwoven fabric according to a preferred embodiment of the present invention has, for example, both excellent texture and high stretch recovery. Moreover, since the stretchable nonwoven fabric according to a preferred embodiment of the present invention can be easily obtained by a single heat treatment in the production process of the spunbond method, high productivity and cost reduction are possible. Furthermore, the article according to a preferred embodiment of the present invention is suitable for the fields of cushioning materials, packaging materials, and medical materials for trauma, which require excellent texture and high stretch recovery.

Hereinafter, the present invention will be described in detail.
The stretch nonwoven fabric of the present invention is a stretch fabric obtained by forming a thermocompression bonding portion with an embossing roll from a composite filament composed of a low melting point resin and a high melting point resin, obtained by a spunbond method. It is a nonwoven fabric. The composition of the composite filament requires that the low melting point resin contains polyethylene and the high melting point resin contains polyester, and may be composed of only polyethylene and only polyester. By combining these thermoplastic resins into a composite filament, it is possible to develop three-dimensional crimps in the subsequent thermocompression bonding step. Moreover, this stretchable nonwoven fabric may contain fibers other than the composite filament made of a low melting point resin and a high melting point resin, obtained by a spunbond method. This stretchable nonwoven fabric is composed of 2 to 100, preferably 10 to 100, more preferably 50 to 100 of the composite filaments, and a composite (hereinafter referred to as a “converging portion”) in which the composite filaments are fused in parallel. The filament has a non-fused portion (hereinafter referred to as “non-focusing portion”), and the composite filament of the focusing portion and the non-focusing portion forms a three-dimensional crimp. In order to obtain such a web, it can be suitably obtained by pulling and drawing a filament group discharged from a spinneret into an air soccer ball of a gun type slot in a spinning process by a spunbond method. Further, in the step of forming the thermocompression bonding part, by partially thermocompression bonding this web using an embossing roll having a convex area ratio in the range of 4 to 30% with respect to the total area of the embossing roll, To form a nonwoven fabric. At the same time, since the web comes into contact with a portion other than the convex portion of the embossing roll, a heat shrinkage action occurs and a three-dimensional crimp is developed. In particular, the basis weight of the web is 10 to 150 g / m ² , and the clearance between the two sets of embossing rolls is particularly preferably 0 to 80 μm for the expression of steric crimps. The non-woven fabric obtained by the above production conditions is formed by 2-100 composite filaments arranged in parallel and weakly joined in parallel by fusion. The unfocused portion that has been unwound and the focused portion where the weak junction remains are formed. In this nonwoven fabric, the thermocompression bonding part and the non-compression bonding part are formed by partially thermocompression of filaments in the web by the convex part of the embossing roll.

  The manufacturing apparatus used for the spunbond method, which is a method for manufacturing the stretchable nonwoven fabric of the present invention, will be described. The spunbond spinning device is an extruder for melting thermoplastic resin and discharging it from the spinneret as a filament, an air soccer ball for pulling and stretching the filament group discharged from the spinneret, and opening the discharged filament group An opening device such as a flap, a conveyor having a suction device for carrying a fleece group (which may be referred to as a “web” in this specification) formed by accumulating discharged filament groups, and the web It comprises a heat embossing device for thermocompression bonding with an embossing roll. By using these production apparatuses, a long-fiber nonwoven fabric can be produced from a thermoplastic resin.

  The stretchable nonwoven fabric of the present invention can be produced by appropriately selecting the following processing conditions. As a raw material thermoplastic resin, a low melting point resin (hereinafter sometimes referred to as “component A”) and a high melting point resin (hereinafter sometimes referred to as “component B”) are used. A composite filament having a composite, eccentric sheath-core composite cross-sectional shape is manufactured. Here, the weight ratio of the A component and the B component is preferably in the range of A component / B component = 20/80 to 80/20 wt%, more preferably 40/60 to 60/40 wt%. When the component A is 20% by weight or more, it is preferable that the three-dimensional crimp is easily developed and the stretchability is improved when crimped. Further, if the component A is 80% by weight or less, the long fiber nonwoven fabric containing the composite filament is preferable because it shrinks moderately and has moderate bulkiness and good dimensional stability. Here, in order to make the sectional shape of the filament into a composite, a spunbond spinning apparatus having a spinneret including a spinneret plate for a composite cross section is used. In the present invention, as the cross-sectional shape of the composite filament, a parallel type, a concentric sheath core type or an eccentric sheath core type can be used. However, considering the stability of the kite string, the cross-sectional shape of the concentric sheath core type or the eccentric sheath core type is preferable. Furthermore, in consideration of obtaining good thermal adhesiveness, a low melting point component may be used as the sheath component. At this time, a long fiber nonwoven fabric having good nonwoven fabric strength is obtained.

Specifically, the stretchable nonwoven fabric of the present invention can be produced using the following spunbond method. For example, when producing a sheath-core type composite filament, linear low density polyethylene is used as the low melting point resin for the sheath component, and polyethylene terephthalate is used as the high melting point resin for the core component. These thermoplastic resins as raw materials are respectively put into individual extruders and melt-spun using a spinneret for composite filaments. The filament group discharged from the spinneret is introduced into an air soccer ball having a gun-type slot, pulled and stretched, discharged onto an endless net-like conveyor, and collected. At this time, the composite filaments divided into gun-type slots are lined up in parallel with 2 to 100 composite filaments due to the adhesiveness of the low melting point resin in a semi-solidified state that is becoming a solidified state from a molten state. A portion fused in a bundle (hereinafter referred to as a “converging portion”) is formed. Further, the filament group to be discharged can be opened by passing between a pair of vibrating blades (flaps) or by colliding with a reflecting plate or the like to obtain a uniform web. preferable. The opened filament group is collected as a fleece group (hereinafter sometimes referred to as “web”) on an endless net-shaped conveyor having a suction device on the back surface. The collected fleece group is conveyed while being placed on an endless net-like conveyor, and is an embossing machine (also referred to as a “point bond processing machine”) composed of heated uneven rolls and smooth rolls. It introduce | transduces between the rolls pressurized and thermocompression-bonded. Thereby, the stretchable nonwoven fabric of the present invention is obtained. In addition, thermal shrinkage occurs simultaneously with thermocompression bonding by passing this embossing machine. At this time, since the focusing of the converging portion of the composite filament is weakly bonded so that the converging can be easily solved, it is divided into a non-focusing portion where the focusing is released and a focusing portion where the focusing remains due to this thermal contraction action.
Thus, in order to manufacture the stretchable nonwoven fabric of the present invention, it is obtained by thermocompression bonding the fleece group which is the configuration of the filament bundle as described above. Furthermore, by this thermocompression bonding, the filament fiber exhibits a three-dimensional crimp, and a stretchable effect is obtained. The temperature at which crimps are developed in the filament bundle, that is, the crimp development temperature is about 5 to 30 ° C. lower than the melting point of the low melting point resin. By this heat treatment, crimps appear and the apparent length shrinks. That is, the heat shrinkage stress of the low melting point resin constituting the composite filament is important.

  The degree of fusion between the fibers in the converging portion is preferably in a state that does not hinder the function of exhibiting stretchability, and is preferably in a state in which the fibers are easily separated. In the completely fused state, the resulting nonwoven fabric is not preferred because the texture is impaired. In the manufacturing process by the spunbond method, when the filament group is discharged from the air soccer ball onto the conveyor, the fiber bundle is maintained and is unwound by a small force such as a shrinking action and a weak drawing action after thermocompression bonding. It is necessary.

The basis weight of the nonwoven fabric can be adjusted by, for example, the spinning discharge speed (discharge amount per hour), the moving speed of the endless net-shaped conveyor, or the like. Moreover, the obtained stretchable nonwoven fabric can be heat-treated as a secondary process to further impart stretchability. The basis weight of the stretchable nonwoven fabric of the present invention may be appropriately selected according to the type of thermoplastic resin used and the use of the stretchable nonwoven fabric, but is preferably in the range of 20 to 300 g / m ² , more preferably 20 It is the range of -200 g / m < ² >, When using especially for a sanitary material, the range of 20-100 g / m < ² > is preferable.

  The fineness of the composite filament is not particularly limited, but is preferably in the range of 0.5 to 12 dtex, more preferably 1.5 to 6.0 dtex in terms of texture and productivity. When the single yarn is 0.5 dtex or more, stable spinnability is obtained, so that the productivity is good. When the single yarn is 12 dtex or less, the touch is good when it is used for contact with the skin. Moreover, it is preferable for the single yarn to be in the range of 0.5 to 12 dtex, since moderate fusion occurs between the filaments.

  When the composite filament used in the stretchable nonwoven fabric of the present invention is discharged from an air soccer ball and collected on a conveyor, it is bundled to obtain a group of loose fleeces having moderate voids. In the subsequent heat treatment, when the fleece group contracts, the filament can move easily, and the filament fits in the gap portion of the filament, so that the protrusion and loosening of the filament can be suppressed on the surface of the contracted long-fiber nonwoven fabric. The surface of the long fiber nonwoven fabric becomes smooth.

  Since the thermocompression bonding part of the stretchable nonwoven fabric is composed of filament bundles, the number of fibers present in the thermocompression bonding part is overwhelmingly higher than that of a general stretchable nonwoven fabric, and the breaking strength of the nonwoven fabric is very strong. Become.

  Since the stretchable nonwoven fabric of the present invention has a three-dimensional structure, it has a very soft texture. Specifically, the stretch recovery rate at 20% stretch in the width direction of the nonwoven fabric is 90% or more, preferably 95. % Or more. Since it has this characteristic, the stretchable nonwoven fabric of the present invention can be used for, for example, a bandage, a base material of a hap material, and the like. These secondary products are preferable from the ergonomic point of view of the wearer because they can provide an excellent texture and at the same time can easily follow the movement of the body position during wearing and can give a refreshing feeling.

The stretchable nonwoven fabric of the present invention has excellent stretchability in the width direction of the nonwoven fabric as described above, but hardly has stretchability in the longitudinal direction of the nonwoven fabric.
Even if the general stretchable nonwoven fabric has sufficient stretchability, the breaking strength in the longitudinal direction is low, and if an excessive force is applied, the nonwoven fabric will shrink in the width direction, making it the required prescribed size However, it is difficult to increase the production speed of the product processing line. On the other hand, the stretchable nonwoven fabric of the present invention has a high breaking strength in the longitudinal direction of the nonwoven fabric and the ratio of 5% elongation strength is 1.5 or less. Since the nonwoven fabric hardly elongates, it has a feature that it can be produced without being affected by the width of the nonwoven fabric when it is produced on a product processing line, for example, from a roll, and can be produced at a high speed. The term “with width” means to shrink in the width direction.

Thermocompression bonding is suitably used as a processing method for obtaining the stretchable nonwoven fabric of the present invention. Since thermocompression bonding is a processing method using heat and pressure as compared with hot air heat treatment, there is an advantage that processing can be performed at a temperature lower than the melting point of the low melting point resin to be welded. That is, the thermoplastic conjugate fiber other than the thermocompression bonding portion is preferably used because the fusing action does not occur due to the heat of thermocompression bonding. The area per thermocompression bonding part is preferably 0.04 to 10 mm ² . Further, the area ratio of the heat-bonded fused area is preferably in the range of 4 to 30%, more preferably 5 to 25% with respect to the nonwoven fabric area before crimping. If the area ratio of the heat-bonded fused area is less than 4%, the nonwoven fabric may be insufficient in breaking strength, and if it greatly exceeds 30%, the texture may be hindered.

  Various shapes can be used for the convex shape of the embossing roll used in the present invention. For example, the planar shape of the tip of the convex portion is various, such as a circle, an ellipse, a square, a rectangle, a parallelogram, a rhombus, a triangle, and a hexagon.

FIG. 1 is an overall appearance photograph showing the surface state of the stretchable nonwoven fabric of the present invention. The vertical direction of the photograph is the longitudinal direction, and the horizontal direction is the width direction. FIG. 2 is an electron micrograph showing a state where a converging portion and a non-focusing portion where the composite filaments of the stretchable nonwoven fabric of the present invention are weakly joined in a bundle are mixed. FIG. 3 is an electron micrograph in which the thermocompression bonding portion of FIG. 2 is enlarged. FIG. 4 is an electron micrograph showing the surface state of a composite long fiber nonwoven fabric made of general polyethylene and polyester. FIG. 5 is an electron micrograph in which the thermocompression bonding portion of FIG. 4 is enlarged.
As is apparent from FIGS. 1 to 3, the stretchable nonwoven fabric of the present invention has a mixed portion and a non-focused portion in which composite filament yarns are arranged in parallel and weakly joined in a bundle, as compared with a general composite long fiber nonwoven fabric. Most of the thermocompression bonding part forms a thermocompression bonding point at the converging part. Further, the non-focusing portion has almost no thermocompression bonding point, and has a bundled state. Thus, the filament yarn concentrated on the thermocompression bonding portion is concentrated in the longitudinal direction of the nonwoven fabric, so that the stretchable nonwoven fabric obtained has a higher breaking strength than the longitudinal direction of the nonwoven fabric. Moreover, the nonwoven fabric with a moderate space | gap is obtained because it is in the state where the convergence part and the non-focusing part were mixed. Thus, the stretchable nonwoven fabric of the present invention exhibits excellent stretchability in the width direction.

  The composite filament used in the present invention needs to be weakly bonded to each other to form a fiber bundle, and further to cause a contracting action by heat treatment. Therefore, as a result of examining the composition and combination of various thermoplastic resins, when the solidification temperatures of the two types of thermoplastic resins to be combined differ in composite spinning, if the solidification of one thermoplastic resin occurs first, the other heat In the plastic resin, a phenomenon that orientation relaxation was observed in the process of cooling to the solidification temperature was observed. Further, in composite spinning, it is necessary to show a tendency that the molecular orientation of the low melting point resin having a low solidification temperature is remarkably lowered and the thermal shrinkage is increased. Further, this tendency appears more conspicuously if the melting point difference between the two thermoplastic resins to be combined is large. In consideration of the texture and the like, the combination of thermoplastic resins is most suitable for polyethylene as a low melting point resin and polyester as a high melting point resin.

In the present invention, the melting point of the low melting point resin and the high melting point resin needs to be higher than that of the low melting point resin, and the difference in melting point is 5 ° C. or more, preferably 10 ° C. or more. More preferably, it is 30 ° C. or higher.
In the present invention, the combination of the low melting point resin and the high melting point resin can be appropriately selected from the relation of the melting point as described above. Specifically, as the polyethylene, at least one selected from the group consisting of high-density polyethylene having a density of 0.910 to 0.960 g / cm ³ , low-density polyethylene and linear low-density polyethylene is preferably used. As the polyester, polyethylene terephthalate or polybutylene terephthalate can be preferably used.

  Further, the low melting point resin and the high melting point resin may be mixed with other thermoplastic resins, respectively, or each may be composed of a single thermoplastic resin. Examples of other thermoplastic resins include polyolefins such as polyethylene and polypropylene, polyesters such as polybutylene terephthalate and polyethylene terephthalate, polyamides such as nylon 6, nylon 66 and aromatic nylon, polyvinyl alcohol such as vinylon, and polycaprolactan. For example, biodegradable resins such as

In the present invention, the low melting point resin contains polyethylene having a density of 0.910 to 0.960 g / cm ³ . As the polyethylene, for example, low-density polyethylene, linear low-density polyethylene, high-density polyethylene and the like that are usually used industrially can be used, and these may be used alone, or a mixture thereof, or These may be used by mixing with other thermoplastic resins. In the present invention, not only polyethylene polymerized using a Ziegler / Natta catalyst but also polyethylene polymerized using a metallocene catalyst can be used. Density polyethylene is preferably in the range of 0.910~0.960g / cm ^3, a range of 0.910~0.940g / cm ³ is particularly preferred. As the polyethylene in this range, a homopolymer whose monomer component is composed only of ethylene or a copolymer of ethylene and an α-olefin other than ethylene can be used, and the melting point is about 100 to 130 ° C. If the density is less than 0.910 g / cm ³ , the fibers are strongly fused, which may cause a problem in the texture. On the other hand, if the density exceeds 0.960 g / cm ³ , when the fineness is reduced, weak bonding does not occur, shrinkage is suppressed, and the required bulk may be difficult to obtain. Moreover, when an elastic nonwoven fabric is obtained by increasing the fineness, the texture tends to be lowered. The MFR (melt mass flow rate) of the low-melting-point resin used in the present invention is not particularly limited as long as it is in a numerical range in which fiberization is possible.

  In the present invention, the high melting point resin contains polyester. As polyester, the acid component is an aromatic dicarboxylic acid such as terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid or the like, or an aliphatic dicarboxylic acid such as adipic acid or sebacic acid or esters thereof, and an alcohol component. As a homopolymer polyester or copolymer polyester synthesized from a diol compound such as ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, etc. Acids, 5-sodium sulfoisophthalic acid, polyalkylene glycol, pentaerythritol and the like are added or copolymerized. These may be used alone, or may be used as a mixture thereof or as a mixture of these with other thermoplastic resins.

  The thermoplastic resin used in the present invention further includes an antioxidant, a light stabilizer, an ultraviolet absorber, a neutralizer, a nucleating agent, an epoxy stabilizer, a lubricant, an antibacterial agent, a flame retardant, an antistatic agent, a pigment, You may add a plasticizer, a hydrophilic agent, etc. suitably as needed.

  The stretchable nonwoven fabric of the present invention can be made into a composite nonwoven fabric by laminating at least one sheet selected from films, nonwoven fabrics, webs, woven fabrics, knitted fabrics, and fiber bundles other than the stretchable nonwoven fabric. The material to be laminated is preferably a material that does not inhibit the stretch of the stretchable nonwoven fabric. Specifically, a material that can be stretched by 20% or more of the composite nonwoven fabric laminated with the stretchable nonwoven fabric is preferred. For example, a material made into a non-woven fabric by a melt blow method using a thermoplastic elastomer resin such as a polystyrene elastomer, a polyolefin elastomer, a polyester elastomer, a polyurethane elastomer or the like, or a material made into a net or a film can be used. Moreover, the material made into the knitted fabric after we fiberized using thermoplastic elastomer resins, such as a polystyrene elastomer, a polyolefin elastomer, a polyester elastomer, and a polyurethane elastomer, is mentioned. In addition, webs, non-woven fabrics, woven fabrics, and knitted fabrics that are structurally elastic by crimping or the like instead of an elastomer material may be used. Furthermore, the material which laminated | stacked the web obtained by the card | curd method or the air raid method by the water jet method, the point bond method, and the through air method is mentioned.

  Examples of textile products using the stretchable nonwoven fabric or composite nonwoven fabric of the present invention include sanitary materials such as disposable diaper stretchable members, diaper stretchable members, sanitary article stretchable members, and diaper cover stretchable members. Medical materials for trauma such as elastic members, elastic tape, adhesive bandages, elastic members for clothes, clothing interlining, insulation and heat insulating materials for clothing, protective clothing, hats, masks, gloves, supporters, elastic bandages, Various filters such as base material for poultice material, base material for plaster material, anti-slip base material, vibration absorbing material, finger sack, air filter for clean room, filter for liquid, oil / water separation filter, electret filter with electret processing, separator , Insulation material, coffee bag, food packaging material, filling cushioning material, automotive ceiling skin material, soundproof material, cushioning material, speaker dustproof , Air cleaner materials, insulator skins, backing materials, adhesive non-woven sheets, various automotive materials such as door trims, various cleaning materials such as copier cleaning materials, carpet surface materials and backing materials, agricultural sheets, drain materials Examples include, but are not limited to, shoe members such as sports shoe skins, bag members, industrial sealing materials, wiping materials, sheets, and the like.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention in detail, this invention is not limited at all by these. In addition, the term and the measuring method of a physical property in an Example and a comparative example are as follows.

(1) Melt mass flow rate (MFR): Measured according to JIS K 7210.
Raw material polyethylene resin: Condition 4 of JIS Table 1

(2) Intrinsic viscosity of polyester Using a mixed solvent of equal weight of phenol and ethane tetrachloride, the viscosity was measured at a concentration of 0.5 g / 100 ml and a temperature of 20 ° C.

(3) Density The density was measured according to JIS K 7112.

(4) Resin melting point (DSC)
It measured based on JISK7122.

(5) A test piece having a 5% elongation strength in the longitudinal direction of the nonwoven fabric, a breaking strength width of 25 mm, and a length of 150 mm is prepared, and a tensile tester Autograph AG-500 (Shimadzu Corporation) is used to set the gap between chucks to 100 mm. Set and secure the specimen. At a tensile rate of 100 mm / min, the strength when the nonwoven fabric was stretched by 5% and the strength when stretched until the nonwoven fabric was broken were measured.

(6) Specific strength ratio of 5% elongation strength and breaking strength in the longitudinal direction of the nonwoven fabric = breaking strength / 5% elongation strength

(7) Elongation recovery rate in the width direction of the nonwoven fabric: measured according to JIS L1096 A test piece of 50 mm in the longitudinal direction of the nonwoven fabric and 150 mm in the width direction was prepared, and tensile tester Autograph AG-500 (Shimadzu Corporation) The test piece was fixed by setting the gap between chucks to 100 mm. After pulling up to 120 mm under the condition of a test speed of 100 mm / min, let it pass for 1 minute in that state, then return to the original position at the same speed to release the load, and let the length L (mm) after standing for 3 minutes The elongation recovery rate was calculated by the following formula.
Elongation recovery rate (%) = {(120−L) / 20} × 100
It should be noted that the elongation recovery rate obtained by the above equation is sufficient if it is 90% or more.

(8) Non-woven fabric texture The sensory test by 5 panelists is conducted, and the case where all are judged to be soft is excellent, the case where 3 or more are judged to be soft, and the case where 3 or more are lacking in softness When judged, it was evaluated as “impossible”, and “Excellent” was indicated by “Good”, “Good” by “△”, and “No” by ×.

(9) Filament fineness An arbitrary portion is cut out from the nonwoven fabric, and the cross section of the fiber is observed with a scanning electron microscope (JEOL Datum: model MP-169008-0038), and the average value of the diameters of 20 fibers. Was calculated. The calculated average fiber diameter was converted from the fiber density to the fineness.

(10) Surface observation of non-woven fabric An arbitrary portion is cut out from the non-woven fabric, the surface of the non-woven fabric is observed with a scanning electron microscope (JEOL Datum: model MP-169008-0038), and the number of fibers in the converging portion. (Average of n = 10), the presence or absence of three-dimensional crimps of the composite filament of the converging portion and the non-focusing portion was confirmed.

Examples 1-8, Comparative Examples 1-3
The polyethylene resin shown in Table 1 was used as the low melting point resin (component A), and the polyester resin shown in Table 1 was used as the high melting point resin (component B). Polyethylene terephthalate was used as the polyester.

  The long fiber nonwoven fabrics used in the examples and comparative examples shown in Table 1 were produced by the spunbond method. Specifically, the thermoplastic resin is configured as shown in Table 1, and the thermoplastic resin is put into an individual φ60 mm extruder, the extrusion temperature of the low melting point resin is 240 ° C., and the extrusion temperature of the high melting point resin is 280. The temperature was set to 0 ° C., extrusion was performed so that the ratio of the sheath core volume ratio shown in Table 1 was reached, and melt spinning was performed using a sheath core type or an eccentric sheath core type spinneret. The filament group discharged from the spinneret was introduced into a plurality of air footballs divided into gun-type slots and pulled and drawn to obtain a filament group. Subsequently, the filament group discharged from the air soccer ball was charged by applying it to a corona discharge device, and then opened by passing between a pair of vibrating blades. The opened filament group was collected as a fleece group on an endless net-like conveyor provided with a suction device on the back surface. At this time, the pulling speed of the air soccer was appropriately adjusted according to the type of the filament so that the fineness of the filament was as shown in Table 1. The collected fleece group is transported while being placed on an endless net-like conveyor, and is a pressurized roll of a point bond processing machine composed of an uneven roll and a smooth roll heated at the processing temperature described in Table 1. Introduced in between. The introduced fleece group was a long fiber nonwoven fabric in which the low melting point resin was melted or softened in the area corresponding to the convex portion of the embossing roll and the filaments were thermally fused. The moving speed of the endless net-shaped conveyor was adjusted according to the type of filament so that the basis weight of the long-fiber nonwoven fabric would be the basis weight shown in Table 1. The peripheral speed of the embossing roll was the same as the moving speed of the endless net conveyor. The linear pressure between the rolls was unified to 80 N / mm, and the area ratio of the convex portions was unified to 15%.

  As is clear from Table 1, in Examples 1-8, the obtained long fiber nonwoven fabric had a mixed portion and a non-focused portion in which filament yarns were weakly joined in a bundle shape as shown in FIGS. It had an appearance, and the number of fibers in the converging portion was 80, and it was confirmed that the composite filament of the converging portion and the non-focusing portion had a three-dimensional crimp. These long fiber nonwoven fabrics had a high breaking strength in the longitudinal direction and a small strength ratio. Thus, the long-fiber nonwoven fabric, which is the stretch nonwoven fabric of the present invention, can suppress the width of the nonwoven fabric when taken from the nonwoven fabric roll, is excellent in high-speed productivity, and has a good elongation recovery rate in the width direction. Therefore, it was confirmed that it was excellent in elasticity. Since the long fiber nonwoven fabric which is the stretchable nonwoven fabric of the present invention has an excellent texture, it can be suitably used for applications such as sanitary materials. On the other hand, the long fiber nonwoven fabric obtained in Comparative Example 1 was excellent in texture, but the obtained filament was not a fiber bundle, and no stretchability was observed. The long-fiber nonwoven fabric obtained in Comparative Example 2 was a fiber bundle and had a sufficient strength ratio, but the elongation recovery rate was small, and no stretchability was observed. The long-fiber non-woven fabric obtained in Comparative Example 3 was a fiber bundle, and although some stretchability was observed, the entire filament was fused, and the texture of the non-woven fabric was very poor.

Example 9
20 g / m ² of fabric weight composed of the stretchable nonwoven fabric of Example 1 and three-dimensional crimped polyolefin staple fiber was laminated and placed on a water jet (conveyor belt composed of 80 mesh plain weave, at a conveyor belt speed of 20 m / min. Using a nozzle diameter of 0.1 mm, a nozzle pitch of 1 mm, and a water pressure of 5 MPa, the front and back surfaces were entangled four times to produce a composite nonwoven fabric. A supporter was produced from the composite nonwoven fabric obtained, and this was wound around the knees of five monitors for 24 hours. As a result, the supporter was not displaced or removed due to insufficient tightening.

Example 10
An analgesic agent was applied to the stretchable nonwoven fabric of Example 5 to prepare a hap material, and this was applied to the elbows of five monitors for 24 hours. Following the movement, there was no slippage or peeling of the hap material. This shows that this stretchable nonwoven fabric can also be used as a medical material for trauma such as adhesive bandages.

Example 11
When the stretchable nonwoven fabric of Example 8 was used as a cushioning material for packaging glassware, it was stretchable and adhered to the glassware, functioned as a sufficient cushioning material, and was able to protect the glassware from impact. At the same time, it was found that this stretchable nonwoven fabric can also be used as a packaging material.

Example 12
When the stretchable long-fiber non-woven fabric of Example 3 and the non-woven fabric of Comparative Example 1 were used as wipes for wiping, the wiper made from Example 3 showed very excellent wiping properties compared to the wiper made from Comparative Example 1. It was.

  The stretchable long fiber nonwoven fabric of the present invention can be suitably used not only for sanitary materials such as diapers, but also for applications such as bandages and hap material base fabrics. In addition, it can be used for applications such as body towels, wipers, wiping cloths, packaging materials, and cushioning materials.

It is a whole external appearance photograph which shows the surface state of the elastic nonwoven fabric which concerns on this invention. It is an electron micrograph which shows the state where the convergence part and the non-focusing part which the composite filament thread | yarn of the elastic nonwoven fabric which concerns on this invention weakly joined in the bundle shape were mixed. It is the electron micrograph which expanded the thermocompression bonding part of the elastic nonwoven fabric which concerns on this invention. It is an electron micrograph which shows the surface state of a general composite long fiber nonwoven fabric. It is the electron micrograph which expanded the thermocompression bonding part of the general composite long fiber nonwoven fabric.

Claims (11)

  A web composed of composite filaments obtained by a spunbond method is a stretchable nonwoven fabric obtained by thermocompression bonding with an embossing roll, and the composite filaments are composed of a low-melting resin and a high-melting resin. The resin contains polyethylene, the high melting point resin contains polyester, and the stretchable nonwoven fabric is a portion where 2 to 100 composite filaments are fused in parallel (hereinafter referred to as a “converging portion”). ) And a portion where the composite filament is not fused (hereinafter referred to as “non-focusing portion”), and the composite filament of the focusing portion and the non-focusing portion forms a three-dimensional crimp. Elastic nonwoven fabric.   The stretchable nonwoven fabric according to claim 1, wherein the low melting point resin is polyethylene and the high melting point resin is polyester.   The stretchable nonwoven fabric according to claim 1, wherein the melting point of the high melting point resin is higher by 5 ° C. than the melting point of the low melting point resin. The polyethylene is at least one selected from the group of crystalline polyethylene having a density of 0.910 to 0.960 g / cm ³ consisting of high density polyethylene, low density polyethylene and linear low density polyethylene, and the polyester is polyethylene terephthalate. Or the elastic nonwoven fabric of any one of Claims 1-3 which is a polybutylene terephthalate.   The stretchable nonwoven fabric according to any one of claims 1 to 4, wherein the stretch recovery rate at 20% stretch in the width direction of the stretchable nonwoven fabric is 90% or more.   The stretchable nonwoven fabric according to any one of claims 1 to 5, wherein a ratio between the breaking strength in the longitudinal direction of the stretchable nonwoven fabric and the 5% elongation strength is 1.5 or less.   The composite nonwoven fabric obtained by laminating | stacking the elastic nonwoven fabric of any one of Claims 1-6, and another sheet | seat.   A wiper using the stretchable nonwoven fabric according to any one of claims 1 to 6 or the composite nonwoven fabric according to claim 7.   A packaging material using the stretchable nonwoven fabric according to any one of claims 1 to 6 or the composite nonwoven fabric according to claim 7.   A cushioning material using the stretchable nonwoven fabric according to any one of claims 1 to 6 or the composite nonwoven fabric according to claim 7. A medical material for trauma using the stretchable nonwoven fabric according to any one of claims 1 to 6 or the composite nonwoven fabric according to claim 7.

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