JPS5976959A - Nonwoven fabric - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bulky nonwoven fabric having a low basis weight, high strength, softness, and excellent texture without feeling slimy.

Demand for nonwoven fabrics has grown rapidly in recent years, especially for
Among O~50 f/nf, low basis weight nonwoven fabrics of 15~8597 yd are frequently used as disposable nonwovens in the field of sanitary materials. Nonwoven fabrics in this field are required to have a low basis weight, bulk, strong sieving strength, and at the same time, have little fuzz, have a soft texture, and are pleasant to the touch. The conventionally widely used binder-adhesive fabrics have the problem that the texture becomes hard when the amount of binder used increases in response to the demand for increased strength. For applications such as surface materials for napkins and the like, the types of binders that can be used are severely restricted due to the amount of residual formalin required by law, and hydrophobic synthetic fibers such as polypropylene and polyester tend to be the mainstream raw materials for nonwoven fabrics. It is becoming increasingly difficult both technically and economically to maintain both strong and soft texture with the binder adhesive type.

In addition to this background, due to low equipment costs and low energy consumption, so-called binder-free nonwoven fabric manufacturing methods that fix the structure of nonwoven fabric constituent fibers by fusing thermally adhesive fibers are attracting attention. It has achieved some results.

However, hydrophobic synthetic fibers such as polypropylene and polyester inherently have a waxy and slimy feel, and especially those with a thin fineness have a strong slimy feel on the sides. Discomfort caused by a slimy feeling has become a new problem in products that come into direct contact with pressure, such as hygiene products, which are the main uses of nonwoven fabrics.

In order to solve the above-mentioned problems, the present inventors have conducted intensive research on bulky non-woven fabrics with low basis weight, high strength, softness and excellent texture without a slimy feeling. The present invention was completed based on the knowledge that the desired objective could be achieved by using heat-adhesive fibers.

The foamed fiber used in the present invention has a single fiber fineness of 0.5 to
It is a 6 denier parallel type or sheath-core type composite fiber. In the parallel type, only the composite component that dominantly forms the fiber surface along the fiber axis direction is the sheath and in the sheath-core type. It refers to a polypropylene or polyester foamed conjugate fiber that has a structure in which only the components substantially contain foamed cells and some of the cells are opened on the fiber surface.

When the single fiber fineness of the foamed fibers exceeds 6 denier, the texture of the resulting nonwoven fabric becomes hard, and when it is less than 0.5 denier, the nonwoven fabric has a waxy and slimy texture, and Processing troubles occur during the forming process, both of which are undesirable.

The total amount of foamed composite fibers relative to the amount of mold is 30% or more and 80%
Must be less than or equal to If the foam fiber content is less than 80%, the effect of improving the texture of the nonwoven fabric (reducing the slimy feeling) will be small, and if it exceeds 80%, the content of the thermal adhesive fibers described below will be less than 20%. For example, (rl"I"HPl') was disclosed in 1982.

In the nonwoven fabric of the present invention, the fibers constituting the nonwoven fabric are fixed by thermoadhesive fibers, and the form is stabilized.1.For the nonwoven fabric with one binder type, the web is immersed in a binder liquid, or the binder liquid is sprayed onto the web. 1. Since the foamed fibers are manufactured by drying after drying, the binder covers the surface of the foamed fibers, making it impossible to take advantage of the good texture that is characteristic of the foamed fibers. On the other hand, in nonwoven fabrics using thermoadhesive fibers, adhesion occurs only at the contact points between the fibers that make up the nonwoven fabric, such as foamed fibers, and the thermoadhesive fibers.
The foamed fibers are non-woven while retaining their original characteristic texture.

Thermal adhesive fibers include fibers of a single composition (single type thermal adhesive fibers) composed of fiber-forming thermoplastic polymers such as polypropylene, polyethylene, polyester, polyamide, polyvinyl chloride, etc., or fibers with different melting points. There is a composite heat-adhesive fiber made by combining a plurality of components and spun into composite fibers. As the single type thermally bondable fiber, fibers such as polypropylene, polyethylene, and low melting point polyester, which have relatively low melting points and softening points, are preferably used because they can be easily thermally bonded. Composite heat-adhesive fibers can be formed into a fiber shape by having their low-melting point components supported by high-melting-point components, so they can be used not only in the case of single-type heat-adhesive fibers, but also in materials with even lower melting points. In addition, during the heat treatment for adhesion, only the low melting point component is plasticized, and the high melting point component maintains the fiber shape, so there is less thermal deformation of the web, compared to when using a single type thermal adhesive fiber. It has the advantage that a nonwoven fabric with a bulky and flexible texture can be obtained.

As such a composite type thermally adhesive fiber, Japanese Patent Publication No. 55-1
7807. Examples include composite fibers disclosed in Japanese Patent Publication No. 55-26209, etc., in which polypropylene is a high melting point component and a polyethylene, ethylene-vinyl acetate co-x polymer, or a saponified product of the copolymer is a low melting point component.

These heat-adhesive fibers account for 20% by weight or more of the weight of the nonwoven fabric,
They are mixed and used within a range of 70% or less.

If the mixing amount is less than 2%, it is difficult to obtain sufficient strength of the nonwoven fabric, and fluffing occurs on the surface of the nonwoven fabric, which is undesirable. If the mixing amount exceeds 70%, the content of foamed fibers relative to the weight of the nonwoven fabric will be less than 3Q'72 and the feel of the nonwoven fabric will deteriorate, so it is preferably 2.

Note that it is also possible to use a single type of heat-adhesive fiber.
It is also possible to use a mixture of multiple types u'! F,
Naturally, the melting point of the thermally adhesive component of the thermally adhesive fiber is lower than the melting point of the foamed component of the foamed fiber, preferably 20
It is necessary that the temperature is lower than °C.

The nonwoven fabric of the present invention includes foamed fibers of 30% to 80%,
As long as the condition of 20% to 70% heat-adhesive fibers is satisfied, additional fibers can be mixed. The other fibers mentioned here may be any fibers that do not melt or deteriorate during heat treatment for making non-woven fabrics, such as natural fibers such as cotton, linen, and wool, semi-synthetic fibers such as rayon and acetate, polyester, nylon, and polypropylene. Synthetic fibers such as, etc. can be used.

The foamed fibers, heat-adhesive fibers and other fibers are mixed and formed into a homogeneously mixed fiber aggregate of a predetermined basis weight using a conventional card, random univer, or dry bulb method. This fiber aggregate is then heat-treated at a temperature above the melting point of the heat-adhesive component of the heat-adhesive fiber and below the melting point of the foamed fibers and other fibers to form a cine-woven fabric. This heat treatment may be performed using either dry heat or steam heat, and for example, a thermal calendar roll, a suction dryer, a Yankee dryer, etc. can be used.

The nonwoven fabric obtained in this way has no waxy, slimy feel that is typical of ordinary polypropylene fibers or polyester fibers bonded together with heat-adhesive fibers, and has a dry and comfortable feel when it comes in direct contact with the skin. f: The nonwoven fabric of the present invention has a heat-adhesive component of the heat-adhesive fiber. Is it due to the wedge effect caused by the holes that melt into the crack grooves based on the air bubbles that have opened on the surface of the foam fibers? It is said that the strength of the nonwoven fabric required for woven fabrics has been significantly improved, and the generation of fuzz has been extremely suppressed! It is a shrine to the symbol V.

In terms of λ, the nonwoven fabric of the present invention has a 1 degree improvement due to the optical effect of the bubbles present in the foamed fibers, and even without the use of brighteners, it has less transparency and a luxurious look. The presence of the air bubbles increases the bending rigidity of the fibers, resulting in a rich sense of bulk.

The test methods used in the 86 Examples and Comparative Examples to specifically demonstrate the present invention are shown below.

Non-woven fabric JIS L 1096 General textile test method Texture: Sensory test shows that it is slimy! , No feeling at all was marked ◎, very little feeling was marked 09, △ was strong, and very strong was marked ×.

Fuzzing: If the surface of the fabric is not uniform, rub it with your finger and apply it with the naked eye.If the fuzz is not noticeable at all, 1<74+○ if it is barely noticeable, and if it is noticeable, go to ′. Items that stand out in Sister I's work are marked with an x.

Implementation f! l 1-5. Comparative Examples 1 to 3 Each of the horizontal cord mixtures having the compositions shown in the table a was passed through a card machine to form a web with a basis weight of approximately 20 f, and the next item i
The non-viscous fabric was made into a non-viscous fabric by drying it in a Zakujo drum dryer adjusted to 45°C. The planned results of the fluff and texture of the obtained non-woven fabric are also shown in Table 1.

Procedure Amendment Kazuo Wakasugi, Commissioner of the Patent Office, December ZZ, 1157 Ura Showa 1, Indication of the case, Patent Application No. 185467 filed in 1985, 2, Name of the invention, Furufu 8, Name of the person making the amendment. Related Patent applicant: 3-6 Nakanoshima, Kita-ku, Osaka-shi, Osaka Prefecture. i82 (〒530
) (207) Chisso Corporation Representative Sadao Nogi 4, Agent 2-8 Shinjuku, Shinjuku-ku, Tokyo. Town No. 1 (160) 5. Date of amendment order (voluntary amendment) 6. Number of inventions increased by amendment (-2 7. Supplement + Ii subject matter #III 11: "Detailed explanation of the invention" Persimmon.

8. Contents of the sleeve j1 ('') Page 5, line 6, ``7:11.I 1982-''
111 Gusho 57-15 l (disclosed in No. 148).

that's all

Claims (1)

[Claims] It is a parallel type or sheath-core type composite fiber with a single fiber fineness of 0.5 to 6 denier, and in the parallel type, only the composite component that dominantly forms the fiber surface along the fiber axis direction is In the case of the sheath-core type, a fiber assembly or fiber assembly consisting solely of polypropylene or polyester foamed conjugate fiber in which only the sheath component substantially contains foamed cells and has a structure in which some of the cells are opened on the fiber surface. Heat-treating a fiber mixture consisting of 30-80% by weight of a mixed fiber aggregate with other fibers containing 30% by weight or more of the foamed conjugate fibers and 70-20% by weight of heat-adhesive fibers, based on the whole body,
A nonwoven fabric having a basis weight of 10 to 501/y, characterized in that the fiber structure is stabilized by fusing the heat-adhesive fibers.