JP2553271B2 - Nonwoven manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a non-woven fabric having a good texture, and its purpose is to have sufficient strength, soft texture, good impregnability with water, resin, etc. Provided is a non-woven fabric suitable for use in artificial leather, shoe cloth, wipers, various filters, etc., which can be easily processed.

[0002]

2. Description of the Related Art It is known that the thinner the constituent fibers of a nonwoven fabric, the more flexible and supple the nonwoven fabric can be obtained. Although the dry needle punching method is generally used for the entanglement of the non-woven fabric,
In the needle punch method, the fibers are moved and entangled by hooking the fibers on the barbs of the needles, and thus ultrafine fibers having small strength are easily cut and difficult to sufficiently entangle, and can be used only for special fibers such as sea-island fibers.

On the other hand, recently, a non-woven fabric entanglement technique by jetting a high-speed fluid (water needle method) has been developed, which enables the entanglement of ultrafine fibers of 0.5 denier or less, and various methods for producing non-woven fabrics by this method. Have been proposed (JP-A-52-144477 and JP-A-54).
-27066, etc.).

Further, when a non-woven fabric produced by a wet method is entangled by jetting a high-speed fluid, the non-woven fabric-like material has a large apparent density due to the fineness of the fibers and the compression effect of the high-speed fluid, which is improved. As another method, a method has been proposed in which polyvinyl alcohol fibers (PVA fibers) that dissolve in hot water are mixed to form a nonwoven fabric, and then the PVA fibers are dissolved and removed with hot water (JP-A-55-90684).

In this method, however, since the fibers are extra fine fibers, the entanglement by jetting the high-speed fluid is not sufficient for the strength of the non-woven fabric and the abrasion property is poor, and since the PVA fibers are dissolved, the process becomes complicated and special. There are drawbacks such as the need for various devices.

In the wet method, short fibers are usually used, but since the entanglement of the fibers cannot be sufficiently obtained by jetting a high-pressure water stream, fluff easily occurs and the strength is insufficient, and the web is reinforced with a woven or knitted fabric. There is a need to.

[0007]

OBJECT OF THE INVENTION The object of the present invention is to provide an artificial leather, shoe cloth, wiper which has sufficient strength as a non-woven fabric, has a soft texture, has good impregnability with water, resin, etc., and has a simple manufacturing process. An object of the present invention is to provide a non-woven fabric suitable for various uses such as filters.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, "a sulfoisophthalic acid copolymerized polyester fiber having a single yarn fineness of 0.5 denier or less and Δn 0.13 to 0.18 and a single yarn fineness of 0.5 denier, Δn 0.001" is used. 0.1% by weight of sulfoisophthalic acid-copolymerized polyester fiber 20:80 to 80: 2
The method for producing a non-woven fabric is characterized in that a high-speed water fluid is jetted onto the non-woven fabric mixed and produced at a ratio of 0 to entangle the constituent fibers, and then dried and heat treated.

In the present invention, Δn 0.15 to 0.18
Sulfoisophthalic acid copolyester fiber (high Δ
n fiber) is, for example, 0.5 to 7.0 mol% of a metasodium sulfoisophthalic acid component, and 0.5 to 10 mol%.
Melt-spun polyester having a repeating unit containing the isophthalic acid component, and then flow-stretched at a draw ratio of 5 times or more, then neck stretched at 1.05 times or more, and further 2-40% limited shrinkage under moist heat. Can be manufactured by the following method (super draw method).

The sulfoisophthalic acid copolymerized polyester fibers having a Δn of 0.001 to 0.1 (low Δn fibers) are, for example, 0.5 to 7.0 mol% of a metasodium sulfoisophthalic acid component and 0.5. It can be produced by melt-spinning a polyester having a repeating unit containing 10 to 10 mol% of an isophthalic acid component, and then performing flow drawing at a draw ratio of 5 times or more.

The main reason for using the sulfoisophthalic acid-copolymerized polyester fiber here is to improve the dispersibility in water and impart hydrophilicity to the resulting nonwoven fabric, and it is easy to produce ultrafine fibers by the super draw method. That is the case.

When the single yarn fineness of the high Δn fiber exceeds 0.5 denier, the flexibility of the product becomes poor. High Δn Fiber Δn
Is less than 0.13, the strength of the fiber becomes insufficient,
When it exceeds 8, the modulus of the fiber becomes too high, and the texture of the product becomes coarse and hard. If the Δn of the low Δn fiber is less than 0.001, the spinnability becomes poor, and if it exceeds 0.10, the adhesive strength at the time of papermaking becomes low and the papermaking becomes impossible.

[0013] Generally, as a method for increasing the strength of a web, there is known a method of utilizing thermal adhesiveness of ethylene vinyl alcohol fiber, copolymer low melting point polyester fiber, polyethylene-polypropylene composite fiber and the like. Adhesive fibers are not suitable because the web is fixed and the texture is hardened.

In the present invention, by using a low Δn fiber having a Δn of 0.01 to 0.1 in place of the conventional heat-fusible fiber, a strength sufficient for papermaking is imparted, and the fibers are entangled with a water needle. You're getting enough web strength.

The ratio of high Δn fibers to low Δn fibers is 20:
A ratio of 80 to 80:20 is good. If the proportion of high Δn fibers is too large, the adhesive strength will be insufficient, and if the proportion of low Δn fibers is too large, the nonwoven fabric will be highly shrunk and the texture will be hardened.

Polyester fibers include polyethylene phthalate, polybutylene terephthalate, or isophthalic acid, isophthalic acid sodium sulfonate,
It is a fiber made of a copolymer obtained by copolymerizing polyoxybenzoate and the like.

The fiber length is preferably 3 to 20 mm. If it is too short, the entanglement strength of the fiber will be difficult to appear, and if it is too long, dispersibility in water will be poor.

As the method for producing the non-woven fabric, there are a dry method using a needle punch and a wet papermaking method from an aqueous dispersion.
In the dry method, the wet papermaking method is particularly preferable because the fiber diameter is small and the fibers are cut by a needle punch so that the entanglement strength is difficult to be produced. In the case of the wet papermaking method, fibers are dispersed in water at an appropriate concentration, mixed and stirred to form a uniform slurry, and water is filtered on a wire net to collect the fibers.

In order to obtain a uniform slurry dispersion, it is advisable to add, for example, a polyethylene glycol copolymerized polyester hydrophilizing agent and / or a thickening agent such as polyacrylamide, polyvinyl alcohol or carboxymethyl cellulose. The papermaking method may be any of the generally used short-netting method, long-netting method, or cylinder method.

As the laminating method, a combination of a generally used short-mesh method, long-mesh method and circular-mesh method can be used.
The non-woven web thus obtained is jetted with a high-speed water fluid to entangle the constituent fibers. To further increase the strength of the non-woven fabric, a woven or knitted fabric is placed on the back surface or in the middle of the non-woven fabric and jetted at high speed.

A method of entanglement of constituent fibers by jetting a high-speed water flow is disclosed in, for example, US Pat. Nos. 3,508,308 and 3,620,903. When jetting a high-speed water stream, it is preferable to place a non-woven fabric on a wire mesh of 40 to 200 mesh, suck it from below and drain it. For example, pressure injection is performed at 10 to 100 kg / cm ² by a pump using an injection nozzle having a diameter of 0.05 to 0.5 mm.

The non-woven fabric thus obtained is impregnated with a resin such as polyurethane or vinyl chloride, subjected to backing and the like, and then buffed on the surface with emery paper or the like to obtain a good artificial leather. You can Further, after the wet papermaking, it may be dried at 90 to 150 ° C. with a Yankee, an oven dryer or the like, and then a high-pressure water stream may be jetted.

The basis weight of the non-woven fabric may be appropriately selected according to the application, but it is generally preferably 30 to 500 g / m ² .

[0024]

EFFECT OF THE INVENTION Since the nonwoven fabric of the present invention uses ultrafine fibers, it has a soft texture and has a capillary structure, so that it has good impregnability with water and resin liquid, and low Δn fibers. Since the fabrics are bonded together, there is sufficient strength, less fluffing occurs, and since hydrophilic sulfoisophthalic acid copolyester fiber is used, the hydrophilicity of the fiber surface is good, and during papermaking. It has excellent performance such as good water dispersibility.

It is suitable for use in artificial leather, shoe cloth, spectacle wipes, sanitary materials, wipers, various filters and the like.

Next, the present invention will be described in detail with reference to examples. All parts in the examples are parts by weight, and the following evaluation items were based on the following measuring methods. (1) Basis weight: Measured according to JIS P-8124. (2) Strength: Measured by Instron (kg / 1.5 cm). (3) Flexibility: According to the cantilever method. (4) Hydrophilicity: measured by the wicking method.

[0027]

Examples 1 to 4, Comparative Examples 1 and 2 Melt polyethylene terephthalate having a repeating unit containing 4.5 mol% of metasodium sulfoisophthalic acid component and 4.5 mol% of isophthalic acid component. After spinning, the film was flow-stretched at a draw ratio of 10 times, then neck-drawn at a draw ratio of 1.5, and then subjected to a 5% limiting shrinkage treatment under moist heat to obtain 0.2.
Denier (Δn 0.135) high Δn fibers were cut to a length of 5 mm. On the other hand, a polyethylene terephthalate having a repeating unit containing 4.5 mol% of metasodium sulfoisophthalic acid component and 3 mol% of isophthalic acid component was melt-spun and then flow-stretched at a draw ratio of 10 to obtain. Single yarn fineness 0.2 denier, Δn 0.004 low Δn
The fibers were cut to 10 mm. Both were mixed at the mixing ratio shown in Table 1 to make 100 parts in total, and dispersed in 100,000 parts of water at room temperature to obtain a slurry. To improve the dispersion of fibers, 100 ppm of polyethylene glycol-polyester copolymer hydrophilizing agent and 50 ppm of polyacrylamide were added to the slurry. These slurries were paper-made by a short-net paper machine to prepare a non-woven web having a basis weight of 200 g / m ² , and then a high-speed water stream was jetted onto the obtained web to entangle the fibers.

The high-speed water flow was jetted by placing a non-woven fabric on a 100-mesh wire mesh and applying a pressure of 60 kg / cm ² from a nozzle having a diameter of 0.2 mm from above 30 mm. The nonwoven fabric was dried with an oven dryer at 120 ° C. for 10 minutes. The performance of the obtained nonwoven fabric is shown in Table 1.

[0029]

[Table 1]

[0030]

[Example 5] Paper was made with a short screen under the same conditions as in Example 2, and then Δn 0.145, single yarn fineness 0.2 denier, high Δn polyester fiber with fiber length 10 mm and Δn 0.08, single yarn fineness 0.2. Denier and low Δn polyester fiber having a fiber length of 10 mm were mixed at a mixing ratio of 80:20 to prepare a slurry, and the nonwoven web obtained by making paper with a cylinder machine was made into paper. 2
A layered nonwoven fabric was obtained. Then, after injecting a high-speed water fluid similarly to Example 2, it dried at 120 degreeC with the oven dryer for 10 minutes. The performance of the obtained nonwoven fabric is shown in Table 2.

[0031]

[Table 2]

[0032]

Comparative Example 3 Δn 0.150, 0.5 having a repeating unit containing 4.5 mol% of metasodium sulfoisophthalic acid component and 4.5 mol% of isophthalic acid component.
Denier, Δn 0.004 having a repeating unit containing polyethylene terephthalate fiber having a fiber length of 10 mm, 4.5 mol% of metasodium sulfoisophthalic acid component and 3 mol% of isophthalic acid component, single yarn fineness of 1 denier,
The same treatment as in Example 1 was carried out except that polyethylene terephthalate fiber having a fiber length of 10 mm was used. Table 3 shows the performance of the obtained nonwoven fabric.

[0033]

[Table 3]

[0034]

[Example 6] The two-layer laminated nonwoven fabric obtained in Example 5 was impregnated with a 28% dimethylformamide (DMF) solution of a polyether-based urethane elastomer, and then squeezed with a mangle to 80% of the pickup, and then put into water. After the polyurethane was solidified, it was washed with water and dried at 120 ° C. for 10 minutes. The surface of the obtained polyurethane-impregnated non-woven fabric was buffed with 240 mesh emery paper to obtain artificial leather. The performance of the obtained artificial leather is shown in Table 4.

[0035]

[Table 4]

[0036]

Comparative Example 4 Polyethylene terephthalate having a repeating unit containing 4.5 mol% of metasodium sulfoisophthalic acid component and 4.5 mol% of isophthalic acid component was melt-spun and then stretched 7 times. Flow stretched at a draw ratio, then neck stretched at 1.5 times, then 5% under moist heat.
Single yarn fineness 0.2 denier, Δ
High Δn obtained by cutting ultrafine fibers of n0.120 to a fiber length of 5 mm
Polyethylene terephthalate having a repeating unit containing 80 parts of fibers, 4.5 mol% of metasodium sulfoisophthalic acid component and 3 mol% of isophthalic acid component was melt-spun and then flow-stretched at a draw ratio of 10 times. The procedure of Example 1 was repeated except that 20 parts of short fibers obtained by cutting low Δn fibers having a single yarn fineness of 0.2 denier and Δn 0.04 into 10 mm were mixed to make a total of 100 parts. The performance of the obtained nonwoven fabric is shown in Table 5.

[0037]

Comparative Example 5 Polyethylene terephthalate having a repeating unit containing 4.5 mol% of metasodium sulfoisophthalic acid component and 4.5 mol% of isophthalic acid component was melt-spun and then stretched 20 times. Flow stretched at a draw ratio, then neck stretched at 1.5 times, then 5% under moist heat.
Single yarn fineness 0.2 denier, Δ
High Δn obtained by cutting ultrafine fibers of n0.190 to a fiber length of 5 mm
Polyethylene terephthalate having a repeating unit containing 70 parts of fiber, 4.5 mol% of metasodium sulfoisophthalic acid component and 3 mol% of isophthalic acid component was melt-spun and then flow-stretched at a draw ratio of 10 times. The obtained single yarn fineness 0.2 denier, Δn 0.04 low Δn fiber 1
The same treatment as in Comparative Example 3 was performed except that 30 parts of short fibers cut to 0 mm were mixed to make a total of 100 parts. The performance of the obtained nonwoven fabric is shown in Table 5.

[0038]

[Table 5]

[0039]

Comparative Example 6 Polyethylene terephthalate having a repeating unit containing 4.5 mol% of metasodium sulfoisophthalic acid component and 4.5 mol% of isophthalic acid component was melt-spun and then stretched 10 times. Flow stretched at a draw ratio, then neck stretched at 1.5 times, then 5% under moist heat.
Single yarn fineness 0.2 denier, Δ
High Δn obtained by cutting ultrafine fibers of n 0.140 into a fiber length of 5 mm
After melt-spinning polyethylene terephthalate having a repeating unit containing 80 parts of fibers, 4.5 mol% of metasodium sulfoisophthalic acid component and 3 mol% of isophthalic acid component, flow drawing was performed at a draw ratio of 15 times. The single yarn fineness of 0.2 denier and the low Δn fiber of Δn 0.11 obtained by the above were mixed with 20 parts of short fibers cut into a fiber length of 10 mm to make a total of 1
Processing was carried out in exactly the same manner as Comparative Example 3 except that the amount was changed to 00 parts. The performance of the obtained nonwoven fabric is shown in Table 5.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display area D21H 13/24 D21H 5/20 D 15/00

Claims (2)

(57) [Claims] 1. A single yarn fineness of 0.5 denier or less, Δn0.
Sulfoisophthalic acid copolymerized polyester fiber of 13 to 0.18 and single yarn fineness of 0.5 denier or less, Δn0.0
After the sulfoisophthalic acid copolymerized polyester fibers of 01 to 0.1 were mixed at a weight ratio of 20:80 to 80:20, a high-speed water fluid was jetted to a nonwoven fabric made into paper to entangle the constituent fibers. A method for producing a non-woven fabric, which comprises performing a dry heat treatment. 2. Single yarn fineness of 0.5 denier or less, Δn0.
Sulfoisophthalic acid copolymerized polyester fiber of 13 to 0.18 and single yarn fineness of 0.5 denier or less, Δn0.0
01-0.1 sulfoisophthalic acid copolyester fibers were mixed at a weight ratio of 20:80 to 80:20 into a non-woven fabric, and a single yarn fineness of 0.5 to 6.0 denier, Δn0. 13 to 0.18 polyester fiber and single yarn fineness 0.5 to 6.0 denier, Δn 0.001 to 0.
The polyester fiber of No. 1 is mixed at a ratio of 20:80 to 80:20, and a high-speed water fluid is jetted to a laminated non-woven fabric to entangle the constituent fibers, followed by dry heat treatment. And a method for producing a non-woven fabric.