JP2000239958A - Nonwoven fabric for hook-and-loop fastener female material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a nonwoven fabric for hook-and-loop fastener female materials having good touch feeling even when used in direct contact with skin and having comfortable wearing property not damaging skin and shape stability by which hook-and-loop female material is not readily stretched or not broken also in repeated detachment of contact part. SOLUTION: This nonwoven fabric comprises a thermoplastic synthetic fiber having 1-8 denier single yarn fineness, in which joining part jointing to male material is formed on one side and simultaneously satisfies the following formulas (1) to (3) (1): Young's modulus in shear direction >=0.8 kgf/cm2. (2): yield point strength in shear direction >=3.0 kgf/5 cm. (3): compressive bending resistance <=300 gf.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simple hook-and-loop fastener for use in disposable applications such as diapers and surgical gowns.

[0002]

2. Description of the Related Art Conventionally, hook-and-loop fasteners have been formed from a pair of a female material having a loop or arch-shaped joint and a male material having a mushroom-shaped or saw-shaped projection joined to the female-material joint. It is used in various fields including clothing, daily necessities, interior materials, industrial materials, etc. due to its ease of use. In general, as the male material of the hook-and-loop fastener, a material formed of a synthetic resin such as nylon, polyethylene, or polypropylene and having mushroom-like or saw-like projections is known, while the female material is nylon or polyester. And a woven or knitted material having a multifilament or monofilament loop or an arch-shaped joint on one side of a synthetic resin such as polypropylene.
When such a surface fastener male material and female material are crimped,
Very strong bonding strength and high bonding durability can be obtained.

[0003] However, in a disposable application, a very high durability and a very high joining strength are not required. Therefore, a female material of the hook-and-loop fastener suitable for the disposable application is disclosed, for example, in Japanese Patent Application Laid-Open No. 6-33359. A female surface fastener made of a long-fiber non-woven fabric having a wrinkle portion is disclosed in JP-A-26462, in which a long fiber web made of a polypropylene-based resin is pressed by a pair of hot-press rolls having a temperature difference. Fastener female materials have been proposed as having excellent joining durability and cost. On the other hand, Japanese Patent Laid-Open No. 7-1
Japanese Patent Application Publication No. 71011 proposes a female fastener material in which a web is needle-punched to form a large number of loops on one side and the other side is fixed with an adhesive substance.

[0004] However, generally speaking, fastener materials are used in a state of being bonded to other equipment and are often used only for the joining function. Therefore, the above-mentioned female material also has high joining strength and durability of joining strength except for cost. Has been proposed as a feature.

[0005] However, recently, there has been a demand for a disposable product which has a nonwoven fabric and a bonding function while making use of the air permeability and flexibility of the nonwoven fabric, instead of being combined with other equipment. Not only has moderate joining strength,
Demand for fastener female material that feels good even when used in direct contact with the skin and does not hurt the skin, and for fastener female material where the fastener nonwoven fabric does not easily stretch or break even when the joint is repeatedly attached and detached The demand for is increasing.

[0006] From the above viewpoint, when catching the female material of the surface fastener proposed above, for example, a female material for a surface fastener made of a long-fiber nonwoven fabric having a wrinkle portion disclosed in Japanese Patent Application Laid-Open No. 6-33359,
The female material for a surface fastener obtained by hot-pressing a long fiber web containing a polypropylene resin disclosed in Japanese Patent Application Laid-Open No. Hei 7-26462 cannot not only obtain the necessary bonding strength, but also obtains a non-woven fastener material when the bonding portion is repeatedly attached and detached. It has the disadvantage that it is easily deformed.

[0007] Further, in the case of a female fastener material in which a web is formed by needle-punching a web disclosed in Japanese Patent Application Laid-Open No. 7-171011 and one surface is fixed with an adhesive substance, the bonding strength is sufficient and the material does not deform even in repeated detachment. Although it has form retention, the other surface that is fixed by the adhesive substance comes into contact with the skin, so it has a rough and hard feel and has a poor touch,
It has a drawback that it may hurt the skin.

[0008]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks of the prior art and has not only a proper bonding strength but also a good touch even when used in direct contact with the skin. It is an object of the present invention to provide a female fastener material having excellent form stability that does not damage the wearing comfort and that the female nonwoven fabric does not easily stretch or break even when the joint portion is repeatedly attached and detached.

[0009]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention.

That is, the present invention is a nonwoven fabric made of a thermoplastic synthetic fiber having a single-fiber fineness of 1 to 8 deniers, wherein a joining portion for joining with a male material is formed on one surface, and the following formula (1)
A nonwoven fabric for a hook-and-loop fastener female material, wherein (3) is simultaneously satisfied. (1) Young's modulus in the shear direction ≧ 0.8 kgf / cm ² (2) Yield point strength in the shear direction ≧ 3.0 kgf / 5 cm (3) Bending softness ≦ 300 gf

The thermoplastic synthetic fibers used in the present invention include fibers made of polyester-based polymers such as polyethylene terephthalate and polybutylene terephthalate, polyamide-based polymers such as nylon 6 and nylon 66, and polyolefin-based polymers such as polyethylene and polypropylene. Is mentioned. Further, even in the case of a single-phase form composed of one kind of polymer, a core-sheath type in which two or more kinds of polymers are compounded,
It may be a composite type such as a lamination type or a multi-leaf type. The fiber at the joint of the female material does not easily stretch when peeled after bonding with the male material, and the nonwoven fabric itself easily expands and does not deform due to repeated detachment, so it has low stretchability and shape stability It is preferable to use an excellent polyester-based synthetic fiber.

Further, as the nonwoven fabric constituting the female member of the hook-and-loop fastener, a nonwoven fabric comprising a composite fiber (core-sheath type, bonded type, multi-leaf type, etc.) in which a part of the fiber surface is made of a low-melting polymer is used. When a nonwoven fabric of a mixed fiber type composed of a fiber composed of a low-melting polymer and a fiber composed of a high-melting polymer is adopted, it is subjected to heat treatment to melt the low-melting polymer and bond the constituent fibers together. Is preferred, since the morphological stability of the nonwoven fabric itself is improved and the nonwoven fabric is not easily deformed by repeated attachment and detachment. The low-melting polymer in this case is not particularly limited, and the above-mentioned polyester-based, polyamide-based, and polyolefin-based polymers may be used, but the deformation of the nonwoven fabric itself is prevented, and the polymer is separated from the male material. At this time, it is more preferable that the high melting point polymer and the low melting point polymer are compatible with each other in order to increase the adhesive strength between the constituent fibers in order to prevent the fibers at the joint from falling off.

The fibers constituting the nonwoven fabric may be long fibers, short fibers such as staples, or a mixture or a laminate of both. But,
After bonding with the male material, it is important that the fibers at the bonding portion do not easily fall off the nonwoven fabric body upon peeling and that the nonwoven fabric itself is not easily deformed. Therefore, it is preferable that the nonwoven fabric be composed only of long fibers. If many fibers are dropped, the dropped fibers are clogged in the hooks of the male material, the bonding performance of the hooks is reduced, and the male material is inferior in bonding durability, and at the same time, the surface of the female material is fluffed, resulting in remarkable quality due to repeated use. Causes a decrease.

The fineness of the thermoplastic synthetic fiber must be 1 to 8 denier, more preferably 3 to 6 denier. If the single fiber fineness is less than 1 denier, the strength of the fibers forming the joint is too weak, so the fibers are easily cut when peeling after joining with the male material, the joining strength of the female material, durability in repeated use Properties are significantly reduced. Further, when a fiber loop to be a joining portion is formed by needling, the fiber is easily broken due to abrasion caused by penetration of a needle or the like, and it is not possible to obtain a sufficient joining strength as a female material of a surface fastener.

On the other hand, if the denier exceeds 8 denier, the fiber strength is sufficient, but for example, in an application where a low-weight female fastener is required as a female fastener, a female material joint portion for joining with a male material is required. Since the number of constituent fibers is relatively reduced, it is difficult to bond with the male material, and the female material itself is apt to cause spotting unevenness, so that bonding unevenness that causes a difference in bonding force is generated. Further, since the rigidity of the fiber is increased, the flexibility of the female material is significantly impaired, which is not preferable. As mechanical properties of the nonwoven fabric for a surface fastener female material, the Young's modulus in the shear direction is 0.8 kgf / cm ² or more, and the yield strength in the shear direction is 3.0 kgf / cm ^2.
It needs to be 5 cm or more.

If the Young's modulus of the female material is less than 0.8 kgf / cm ² , the female material cannot withstand the force in the shear direction applied at the time of joining with the male material, and easily expands. The use performance of the installed product is reduced. Also,
If the yield point strength of the female material is less than 3.0 kgf / 5 cm, the female material easily shifts to plastic deformation due to the shear force applied at the time of joining with the male material, and the structure of the nonwoven fabric collapses. Would. Therefore, in the female material of the present invention, the Young's modulus in the shear direction and the yield point strength must satisfy the above numerical ranges.

The nonwoven fabric satisfying the above mechanical properties includes
For example, there is a material in which fibers constituting the nonwoven fabric are mainly arranged in a shearing direction at the time of joining with the male material. In order to obtain such a nonwoven fabric, it is preferable to arrange the fibers in a desired direction in the web forming step.
When the constituent fibers of the nonwoven fabric are short fibers, the shear direction is MD
In the case of the direction (mechanical direction), a parallel web in which fibers are mainly arranged in the MD direction is used as the web, and in the case where the shear direction is the CD direction (direction orthogonal to the mechanical direction), the parallel web is cross-laid. It is preferable to use a cross-laid web in which fibers are mainly arranged in the CD direction.

When the constituent fibers of the non-woven fabric are long fibers, it is preferable to prepare a web by a spun bond method from the viewpoint of the flexibility of the obtained non-woven fabric, and if the shear direction is the MD direction, melt spinning and take-up. When the opened web is deposited on a net conveyor or the like, for example, the web mainly arranged in the MD direction can be easily obtained by increasing the net conveyor speed. On the other hand, if the shear direction is the CD direction, the device can be swung in the CD direction in the fiber opening step to arrange the fibers in the CD direction.

As a method other than arranging the fibers, when a nonwoven fabric is formed by performing needle punching, the amount of oil applied to the web during needling is reduced, and the amount of oil applied to the finally obtained nonwoven fabric is reduced. It is mentioned. That is, in general, during the needle punching process, the fibers are easily entangled, and, in order to reduce the frictional resistance between the fibers and between the fibers and the needle, in order to not easily cut the fibers caught on the needle blade, An oil agent is applied to a web to be processed before needle punching. The needle-punched nonwoven fabric thus obtained has an oil agent attached,
Since the frictional resistance between the fibers is small and the fiber is slippery, the fiber slides against the tensile force, and is inferior in the form stability of the nonwoven fabric and easily stretched. Therefore, by reducing the amount of oil applied before needle punching, the amount of oil adhering to the obtained needle-punched nonwoven fabric is reduced. , Maintain strong entanglement and improve the morphological stability of the nonwoven fabric. The post-treatment may be performed on the needle-punched nonwoven fabric to which the oil agent has adhered to remove the oil agent. The amount of the oil agent attached to the needle punched nonwoven fabric is preferably 0.2 wt% or less. When the needle-punched non-woven fabric is used as the non-woven fabric for female material, the non-woven fabric may have both the above-mentioned fiber arrangement and the amount of the oil agent attached.

The joint of the female material, which is responsible for joining with the male material, is an aggregate of fiber loops in which both ends of the fiber are buried in the nonwoven fabric. As a method of forming a joint portion, which is an aggregate of fiber loops, on a nonwoven fabric surface, a method of performing a needle punch on a nonwoven web made of thermoplastic synthetic fiber to form a large number of fiber loops on the nonwoven fabric surface, Hot pressing is performed using an embossing roll having irregularities on the roll surface, and the constituent fibers of the nonwoven web abutting on the convex portion of the embossing roll are thermocompression-bonded. There is a method in which fibers are formed, and the fibers are joined to a male material as a fiber loop. Further, as a constituent fiber of the nonwoven fabric, a fiber having a crimp (including a mechanical crimp and a three-dimensional crimp) may be used, and a male hook may be hooked on the crimp portion.

When the female member and the male member are joined, the hook of the male member must enter into the joint portion of the female member. Therefore, the joint portion needs to have a sufficient degree of spatial freedom for the hook to enter. The porosity of the female nonwoven fabric at the joint is 85
% Is preferable. If the porosity of the joint of the female nonwoven fabric is less than 85%, the male hook tends to be less likely to enter the joint. In addition, the rigidity of the female nonwoven fabric tends to increase, and the flexibility tends to decrease. It is sufficient that the joint has sufficient fibers to join with the male hook, and the upper limit of the porosity is about 99%.

In order to further improve the form stability of the female material, the nonwoven fabric may be impregnated with a binder resin, or may be dipped or coated. As the binder resin used in the present invention, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, acrylonitrile, a combination of two or more monomers such as styrene desired molar ratio Such as a copolymer copolymerized in or a cross-linked binder resin in which the copolymer is cross-linked by a cross-linking agent,
General synthetic resins can be used. The type of the binder resin may be appropriately selected depending on the use of the nonwoven fabric for a hook-and-loop fastener female material.

The amount of the binder resin adhering to the nonwoven fabric is preferably 1 to 15% by weight, more preferably 2 to 10%.
% Is more preferred. The role of the present binder resin is to improve the morphological stability of the nonwoven fabric itself. If the amount of the binder resin attached is less than 1%, the amount is too small to fulfill the role of improving the morphological stability. If it exceeds, the non-woven fabric becomes very rigid, which makes the non-woven fabric unsuitable for use in contact with skin requiring flexibility.

The compression stiffness of the nonwoven fabric for female material of the present invention is 30.
0 gf or less. The flexibility is very sensory and is very dependent on the thickness and the like. However, if the compression stiffness exceeds 300 gf, when the thickness of the non-woven fabric is relatively thick, it becomes difficult to wear when worn. If the thickness is relatively small, it is not preferable because it causes pleasure. It is not preferable because it becomes paper-like and causes skin damage at the end.

[0025]

The present invention will be described below in more detail with reference to examples. However, the present invention is not limited to the following examples. Each characteristic value in the following examples was obtained as follows. (1) Intrinsic viscosity (dl / g) of polyester: 0.5 g of a sample was dissolved in 100 ml of a mixed solvent of phenol and ethane tetrachloride at an equal weight ratio, and measured by a conventional method.

(2) Single-fiber fineness (d): The density of the fiber drawn and thinned by the suction device was corrected using an electron microscope, and determined.

(3) Young's modulus in shear direction (kgf / cm
² ), yield strength in shear direction (kgf / 5cm): 30 direction from nonwoven fabric for hook-and-loop fastener female material in shear direction
A test piece was cut out into a rectangle measuring 5 cm in a direction perpendicular to the cm × shearing direction, and the measurement was carried out using Tensilon RTM-500 manufactured by Toyo Baldwin Co., Ltd. at a chuck distance of 20 cm and a tensile speed of 20 cm / min. N = 5
Is determined, and the Young's modulus in the shear direction (kgf / c
m ² ) and yield strength at shear direction (kgf / 5cm)
And

(4) Porosity (%) of Bonded Section The cross section of the nonwoven fabric is photographed, and the thickness of the nonwoven fabric at the joint formed by loops, crimps, etc. is read. The porosity was calculated from the value, the weight of the nonwoven fabric, and the density of the constituent resin.

(5) Compression stiffness (gf): Nonwoven fabric is MD
A rectangular sample having a size of 5 cm in the direction and 10 cm in the CD direction is cut out, the short side of the sample is aligned with the short side, and the central portion is adhered with a tape to form a cylindrical sample. When the sample is placed on a flat plate and crushed by another flat plate perpendicular to the MD direction axis, the maximum strength applied to the flat plate is reduced by a compression speed of 50 m using a Tensilon RTM-500 manufactured by Toyo Baldwin Co., Ltd.
The measurement was performed at m / min to obtain the compression bending resistance in the MD direction. The direction of the cut sample was changed, and the compression stiffness in the CD direction was determined in the same manner. The measurement was performed at n = 5 in each of the MD and CD directions, and the total average value was defined as the compression bending resistance (gf).

(6) Peel strength (gf / cm): JIS L
The test was performed in accordance with the test method for a surface fastener of No. 3416. That is, the sample piece was set to a width of 25 mm and a length of 100 mm, overlapped with a YKK mushroom tape (male material) of the same size, and joined at an end of 50 mm length.
A 2.5 kg iron roller was rolled back and forth and joined. This is Toyo Baldwin Co., Ltd. Tensilon R
Using TM-500, gripping interval 10cm, pulling speed 3
Peeled at 0 cm / min. The strength value was determined from the average of 6 maximum values and 6 minimum values shown when peeling, and the average value of n = 5 was defined as the peeling strength (gf / cm). Peeling strength 5 times repeatedly for each test piece to check durability
(gf / cm) was measured. In the present invention, when the value of the peel strength is 30 to 100 g / cm, it can be said that the bonding strength with the male material is high.

(7) Wearability: Non-woven fabric is 10 cm × 90 c
m, and a mushroom tape made of YKK was stuck to one end and a non-joining surface with a double-sided tape to form a belt-like material. The belt-like material created above was worn for 24 hours so as to directly touch the skin of ten randomly selected panelists, and the wearability was evaluated by the following five-level evaluation based on form stability, flexibility, and soft touch did. Class 5 Very good Class 4 Good Class 3 No problem Class 2 Slightly uncomfortable Class 1 Very uncomfortable In this evaluation, those with an average value of 10 or more of 10 students were judged as passing.

Example 1 A polyethylene terephthalate having an intrinsic viscosity of 0.70 dl / g was melt-spun from a die at a melting temperature of 285 ° C. The fiber to be spun was taken out by air soccer so that the spinning speed was 5000 m / min, and the drawn fiber was collected on a conveyor net so that the weight per unit area (m ² ) became 70 g.

After applying an oil agent (manufactured by Silicone Emulsion DIC Co.) to the long-fiber nonwoven web obtained as described above, the needle density was measured with a needle punching machine (needle: Crown Barb Needle manufactured by Foster). 50 times / cm
^2. Needling is performed at a needle depth of 9 mm, and then an acrylic resin (manufactured by Dainippon Ink and Chemicals, Inc.) is added to the obtained needle-punched non-woven fabric (oil adhering amount: 0.1 wt%) to have a solid adhering amount of 4 wt%. After impregnation as described above, drying was performed to obtain a nonwoven fabric for a hook-and-loop fastener female agent.

Examples 2 and 3 and Comparative Examples 1 and 2 Non-woven fabrics were prepared in the same manner as in Example 1 except that the fineness of single fibers of the constituent fibers and the amount of the binder attached were changed as shown in Table 1.

Table 1 shows the characteristic values and test results of the obtained Examples 1 to 3 and Comparative Examples 1 and 2.

[0036]

[Table 1] As is clear from Table 1, the nonwoven fabric for the surface fastener female material obtained in Examples 1 to 3 has a Young's modulus, a yield point strength, a bending resistance, and a porosity of a joint portion both within the scope of the present invention. For,
It had sufficient bonding strength and comfortable wearing properties. In Comparative Example 1, since the amount of binder attached was large and the compression stiffness was out of the range of the present invention, the morphological stability was excellent, but the mountability was poor. In Comparative Example 2, since the denier of the filament constituent fibers was out of the range of the present invention, the flexibility was poor and the wearability was poor.

[0037]

According to the nonwoven fabric for hook-and-loop fastener female material of the present invention, the fiber loop and the male material hook, which are the joints, can be reliably joined and the shape stability is excellent. Also, the nonwoven fabric for female material is not easily stretched and the nonwoven fabric form is not destroyed. Further, since it has flexibility, it has a good touch even when used in direct contact with the skin, and has a comfortable wearing property that does not damage the skin.

Claims (2)

[Claims] 1. A nonwoven fabric made of a thermoplastic synthetic fiber having a single-fiber fineness of 1 to 8 deniers, having a joint formed with a male material on one surface and simultaneously satisfying the following expressions (1) to (3). Non-woven fabric for hook-and-loop fastener female material, characterized by the following. (1) Young's modulus in the shear direction ≧ 0.8 kgf / cm ² (2) Yield point strength in the shear direction ≧ 3.0 kgf / 5 cm (3) Bending softness ≦ 300 gf 2. The nonwoven fabric for a hook-and-loop fastener female material according to claim 1, wherein a porosity of a joint portion to be joined with the male material is 85% or more.