WO2002000983A1

WO2002000983A1 - Functional non-woven fabric

Info

Publication number: WO2002000983A1
Application number: PCT/JP2001/005419
Authority: WO
Inventors: Satoru Harigai; Hiromitsu Seike
Original assignee: Matsumoto Yushi-Seiyaku Co., Ltd.
Priority date: 2000-06-26
Filing date: 2001-06-25
Publication date: 2002-01-03
Also published as: JP2005097749A

Abstract

A functional non-woven fabric which is produced by scattering thermally expandable micro-capsules on a fiber aggregate in a web form comprising thermally fusible fibers and optionally non-fusible fibers and subjecting a product containing the fiber aggregate and the micro-capsules to a heat treatment. The functional non-woven fabric is excellent in softness, warmness retaining property, and water or oil absorbing property.

Description

Description Functional nonwovens Technical field

The present invention relates to a nonwoven fabric excellent in flexibility, heat retention, water absorption or oil absorption, and more particularly to a nonwoven fabric suitable for clothing and bedding inner layer materials requiring flexibility. Conventional technology

Non-woven fabric with a heat-expandable mic mouth capsule has many voids inside, and is lightweight and excellent in cushioning, heat insulation, soundproofing, or water absorption. It is used as a mat or towel (see JP-A-58-136629 and JP-A-7-238451).

However, these non-woven fabrics use a binder to fix the heat-expandable microcapsules to the non-woven fabric, and therefore lack flexibility and are required for flexibility, especially for clothing and bedding. Not suitable for inner layer material or towel.

In addition, as a method for producing these, a wet method is used in which a thermally expandable microcapsule dispersed in water or a solvent and a binder are impregnated or coated into a nonwoven fabric manufactured in advance. Not reasonable.

U.S. Pat. No. 3,676,288 discloses a method for producing a hydrophilic nonwoven fabric from hydrophilic fibers and thermally expandable microcapsules. However, this specification does not disclose a nonwoven fabric using a web-like fiber aggregate made of a heat-fusible fiber or a combination thereof with a non-heat-fusible fiber. Disclosure of the invention

An object of the present invention is to provide a novel function excellent in flexibility, heat retention, water absorption or oil absorption. An object of the present invention is to provide a functional nonwoven fabric.

Another object of the present invention is to provide a nonwoven fabric obtained by a rational manufacturing method different from the wet method.

Still other objects and advantages of the present invention will become apparent from the following description. According to the present invention, the above objects and advantages of the present invention are:

A heat-fusible fiber exhibiting heat-fusibility at a temperature of 50 to 150 ° C or a non-heat-fusible fiber exhibiting no heat-fusibility at a temperature of 150 ° C or lower with the heat-fusible fiber; A nonwoven fabric obtained by heat-treating a web-like fiber aggregate composed of a combination of conductive fibers and a precursor aggregate consisting of a heat-expandable micro-force cell dispersed between the fibers of the web-like fiber aggregate Is done.

A feature of the present invention is that, during the nonwoven fabric manufacturing process, a heat-expandable micro force cell is sprayed on a heat-fusible fiber or a web-like fiber aggregate composed of a heat-fusible fiber and a non-heat-fusible fiber, followed by heat treatment. Thereby, at the same time as the microcapsule expands, the fiber-to-fiber and the fiber-to-microcapsule are adhered to each other, and a functional nonwoven fabric excellent in heat retention, water absorption or oil absorption can be produced. In addition, since it is not necessary to use a solder, it is excellent in that a functional nonwoven fabric having excellent flexibility can be obtained.

The heat fusible fiber that can be used in the present invention exhibits heat fusibility at a temperature of 50 to 50 ° C. Such a heat-fusible fiber comprises a thermoplastic polymer having a melting point and / or a softening start temperature of 50 to 150 ° C. As such a thermoplastic polymer, for example, polyolefin and polyester can be preferably mentioned.

Since the temperature of the thermoplastic polymer at the time of producing the nonwoven fabric is usually 150 to 170 ° C., the melting point and / or the softening start temperature must be 150 ° C. or lower. Further, since it is required that the obtained nonwoven fabric does not re-melt with hot water or the like, the melting point and Z or the softening start temperature of the thermoplastic polymer must be 50 ° C or more, preferably 90 ° C or more. .

Among the thermoplastic polymers, examples of polyolefins include (co) polymers containing olefins such as ethylene, propylene, butene 1 and pentene 1 as main components. , In addition, as the polyester, the requirements of the melting point and z or the softening start temperature are required. Any material can be used as long as it satisfies the range. In particular, copolymerized polyesters using terephthalic acid, isophthalic acid, adipic acid, sebacic acid, etc. as the acid component, and ethylene glycol, propylene glycol, tetramethylene glycol, dimethylene glycol, etc. as the glycol component are preferable because they are inexpensive. .

Further, the heat-fusible fiber can be a heat-fusible conjugate fiber composed of the above-mentioned thermoplastic polymer and a fiber-forming polymer having a higher melting point than the thermoplastic polymer. As the fiber-forming polymer, for example, polypropylene and polyester are preferably used because they are inexpensive.

The conjugate type of the heat-fusible conjugate fiber is not particularly limited, and may be either a core-sheath type or a side-by-side type.

Examples of the heat-fusible conjugate fiber include a fiber in which a sheath is made of polyethylene and a core is made of polypropylene, a fiber in which a sheath is made of polyethylene, and a core is made of polyester (polyethylene terephthalate; hereinafter, referred to as PET), and copolymerized with PET. A typical example is a fiber obtained by compounding a polyester in a side-by-side type. Other fibers constituting the web-like fiber aggregate, that is, non-heat-fusible fibers that do not exhibit heat-fusibility at a temperature lower than 150 ° C, are natural fibers such as cotton and semi-synthetic fibers such as rayon. Single or plural fibers such as synthetic fibers such as polypropylene, polyester and the like can be used. It is preferable to use a polyester fiber having a fineness of 5 to 15 denier and a crimp rate of 10 to 30% or a fiber imparted with heat storage heat retention, because the heat retention is further improved. When the fineness is smaller than 5 denier, the effect of improving the heat retention is small, and when the fineness is larger than 15 denier, the flexibility is easily impaired. When the crimping ratio is 10% or less, the effect of improving the heat retention is small, and when it is 30% or more, it becomes difficult to produce a uniform web-like fiber aggregate.

In addition, when hydrophilic fibers such as rayon fiber, pulp fiber, cotton, and highly water-absorbing fiber are mixed as the non-heat-fusible fiber, the water absorption of the nonwoven fabric is further improved, so that it is suitable for toweling and bath mat.

On the other hand, if lipophilic fibers such as polypropylene, polyester and polyurethane are used as non-heat-fusible fibers, the oil absorption of the nonwoven fabric can be improved, It is suitable for oil absorption sheets for foods.

Further, it is preferable to use a fiber having a fineness of 2 denier or less as a part of the non-heat-bonding fiber, because it is easy to hold the thermally expanded green microcapsules in the web-like fiber aggregate.

In the combination of the heat-fusible fibers and the non-heat-fusible fibers, the mixing ratio of the heat-fusible fibers is usually 15% by weight or more, preferably 30% by weight or more. If the amount is less than 15% by weight, the heat-expandable microcapsules may fall off or the strength of the nonwoven fabric may be reduced.

The method for producing the web-like fiber aggregate from the heat-fusible fiber alone or a mixture of the heat-fusible fiber and the non-heat-fusible fiber is not particularly limited, but it is preferable to adopt a card method capable of high-speed processing. .

The heat-expandable microcapsule used in the present invention is a microcapsule containing a thermoplastic polymer as a shell and containing a volatile expanding agent which becomes gaseous at a temperature lower than the softening point of the polymer. The particle size is preferably about 10 to 30 m, more preferably 15 to 25; m. As the thermally expandable microcapsules, those which form microballoons having a particle size of about 50 to 150 zm by flapping at about 130 to 200 ° C. are preferably used.

Examples of the shell-forming thermoplastic polymer include homopolymers and copolymers of monomers such as biel chloride, vinylidene chloride, acrylonitrile, butyl acetate, styrene, and methyl methacrylate. The softening point of such thermoplastic polymers is generally about 100-150 ° C.

Volatile swelling agents that become gaseous at temperatures below the softening point of the shell-forming thermoplastic polymer are volatile swelling agents contained within the microcapsules, such as propane, propylene, butene, normal butane, isobutane, Examples include low-boiling substances such as isopentane, neopentane, normal pentane, hexane, heptane, and petroleum ether.

The method for dispersing and dispersing the heat-expandable microcapsules in the web-like fiber aggregate is not particularly limited, but a hot-melt resin supply device used for nonwoven fabric production can be employed. The amount of application depends on the basis weight of the nonwoven fabric, but usually 2 to 40 g a / m ^2.

When spraying the thermal expansion microcapsules, microcapsules containing fragrances, deodorants, repellents, ultraviolet absorbers, etc. can be sprayed, and by doing so, it is possible to provide additional functions .

In addition, after dispersing the heat-expandable microcapsules on the web-like fiber aggregate, another web-like fiber aggregate is laminated thereon and heat-treated to obtain a nonwoven fabric having an excellent appearance. It is preferable to laminate a web-like fiber aggregate on the web. As a heat treatment method, for example, a dryer such as a hot air dryer or a suction drum dryer, or a heating roll such as a flat calender or an emboss roll can be used. It is particularly preferable to use a hot air dryer because a nonwoven fabric having excellent flexibility can be obtained. Example

Example 1

Mp 1 2 5 t: polyethylene sheath component of the polyethylene terephthalate (PET) as a core component, over fineness 2 d, the heat-fusible composite fiber having a fiber length of 5 l mm a roller card, the basis weight 5 0 gZm ² A web made of a thermally expandable microcapsule (Matsumoto Microsphere F-3) with a mean particle size of 20 m, containing vinylidene chloride, acrylonitrile and methyl methacrylate copolymer as a shell, and containing normal butane After spraying 0 D) with 10 gZm ^2, a web having a basis weight of 20 g / m ² of the heat-fusible conjugate fiber was laminated, and treated with a hot-air drier at 150 ° C. for 1 minute to obtain a nonwoven fabric. Table 1 shows the performance of the obtained nonwoven fabric.

Example 2

Example 1 was the same as Example 1 except that 50 parts by weight of the same heat-fusible conjugate fiber used in Example 1 as the web, 50 parts by weight of polyester (PET) fiber having a fineness of 1.3 d and a fiber length of 38 mm were used. Similarly, a nonwoven fabric was obtained. Table 1 shows the obtained results.

Example 3

Since the same thermally expandable microcapsules used in Example 1 were sprayed at ²⁰ g / m2, Outside, a nonwoven fabric was obtained in the same manner as in Example 2. Table 1 shows the obtained results.

Example 4

40 parts by weight of the same heat-fusible conjugate fiber used in Example 1 as the web, 20 parts by weight of the same polyester fiber used in Example 2, fineness 6 d, fiber length 64 mm, crimp rate 18% A non-woven fabric was obtained in the same manner as in Example 1 except that 40 parts by weight of the polyester (PET) fiber was used. Table 1 shows the obtained results.

Comparative Example 1

A chemical pound polypropylene nonwoven fabric with a basis weight of 7 O gZm ² is immersed in an aqueous dispersion of 20 parts by weight of the same heat-expandable microcapsules, 20 parts by weight of an acrylic ester-based binder, and 60 parts by weight of water as used in Example 1. Then, the mixture was squeezed so that the pickup ratio became 70% by weight, and then treated with a hot air drier at 150 ° C. for 3 minutes to obtain a non-woven fabric containing 10 g of Zm ² capsules having a thermally expanded micro-mouth. Table 1 shows the obtained results.

Comparative Example 2

A nonwoven fabric was obtained in the same manner as in Example 1, except that the thermally expandable microcapsules were not sprayed. Table 1 shows the obtained results.

Comparative Example 3

A nonwoven fabric obtained by heat-treating the web used in Example 4 having a basis weight of 70 g / m ² with a hot air drier at 150 for 1 minute was used.20 parts by weight of the same thermally expandable microcapsule cell as used in Example 1. Immersion in an aqueous dispersion of 20 parts by weight of an acrylester-based binder and 60 parts by weight of water, squeezed so that the pickup rate becomes 70% by weight, and then treated with a hot air drier for 3 minutes at 150 ° C. Then, a nonwoven fabric containing 10 g / m ^{2 of} the thermal expansion microcapsules was obtained. Table 1 shows the obtained results. Test No. Heat retention rate (%) Bending degree (g)

Example 1 68.3 331

Example 2 68. 5 213

Example 3 70.2 348

Example 4 77. 6 203

Comparative Example 1 67. 8 1430 Comparative Example 2 53. 6 231

Comparative Example 3 67. 9 1360 Evaluation method

[Insulation rate]

Compliant with JISL 1096A method (constant temperature method).

圆 Softness)

Conforms to the JIS L 1096 E method (handle ome overnight method).

Example 5

A nonwoven fabric was obtained in the same manner as in Example 1, except that the same heat-fusible conjugate fiber as used in Example 1 was used in an amount of 30 parts by weight, the fineness was 2d, and the fiber length was 51 mm. Table 2 shows the obtained results.

Comparative Example 4

A non-woven fabric was obtained in the same manner as in Comparative Example 3, except that the same web having a basis weight of 70 gZm ² as used in Example 5 was used. Table 2 shows the results.

Comparative Example 5

A nonwoven fabric was obtained in the same manner as in Example 5, except that the thermally expandable microcapsules were not sprayed. Table 2 shows the results. Table 2

Evaluation method

(Water absorption of nonwoven fabric)

The nonwoven fabric was cut into 40 mm × 40 mm, immersed in tap water at 20 ° C. for 20 minutes, allowed to stand at room temperature for 20 seconds, weighed, and the amount of water absorption per unit area of the nonwoven fabric was determined.

Example 6

A non-woven fabric was obtained in the same manner as in Example 1, except that 30 parts by weight of the same heat-fusible conjugate fiber as used in Example 1 and 70 parts by weight of a polypropylene fiber having a fineness of 2 d and a fiber length of 51 mm were used. Table 3 shows the obtained results.

Comparative Example 6

A nonwoven fabric was obtained in the same manner as in Comparative Example 3, except that the same web as that used in Example 6 was used with a basis weight of 70 gZm ² . Table 3 shows the results.

Comparative Example 7

A nonwoven fabric was obtained in the same manner as in Example 6, except that the thermally expandable microcapsules were not sprayed. Table 3 shows the results.

Table 3 Test Νοι Oil absorbency (g / m ² ) Bending degree (g) Example 6 1210 205 Comparative Example 6 1090 1380 Comparative Example 7 630 166 Evaluation method

(Oil absorption of nonwoven fabric)

Larose method: Measure the saturated oil absorption of a 9 cm ² sample using a contact oil absorption tester. It was converted to g per 1 m ² and described.

Measurement method: Samples and utensils were stored in a constant temperature room at a temperature of 25 ° C and a humidity of 65% for 24 hours or more, and then subjected to measurement. Oil (salad oil (manufactured by Nisshin Oil Co., Ltd.)) was placed in a vat large enough to immerse the sheet, and a sheet of known weight and area was immersed for 3 minutes. Next, the mixture was allowed to stand on a 10-mesh wire net and drained for 1 minute, weighed, and the difference from the initial weight was divided by the area of the sheet to convert to oil absorption per lm ² .

As described above, according to the present invention, the heat-expandable microcapsules are sprayed on the heat-fusible fibers or the web-like fiber aggregate composed of the heat-fusible fibers and the non-heat-fusible fibers, and then heat-treated. As a result, a functional nonwoven fabric having excellent flexibility, heat retention, P-water or oil absorption properties can be obtained.

Claims

The scope of the claims

1.5 to-; heat-fusible fiber exhibiting heat-fusibility at a temperature of L 50 ° C or non-thermal fusion exhibiting no heat-fusibility at a temperature of 150 or less with said heat-fusible fiber A nonwoven fabric obtained by heat-treating a web-like fiber aggregate composed of a combination of adhesive fibers and a precursor aggregate consisting of a heat-expandable micro-force cell dispersed between fibers of the web-like fiber aggregate.

2. The nonwoven fabric according to claim 1, wherein the material of the heat-fusible fiber is polyolefin or polyester.

3. The nonwoven fabric according to claim 1, wherein the non-heat-fusible fiber is a natural fiber, a semi-synthetic fiber, or a synthetic fiber.

4. The nonwoven fabric according to claim 1, wherein the non-heat-fusible fiber is a polyester fiber having a fineness of 5 to 15 denier and a crimp rate of 10 to 30%.

5. The nonwoven fabric according to claim 1, wherein the non-heat-fusible fiber is a hydrophilic fiber or a lipophilic fiber.