JP2989745B2 - Fiber structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fibrous structure used as a cushioning material, and more particularly, to a fibrous structure having high compressive elasticity and peeling strength, hardly causing sagging and shape change, and excellent in moldability. It is about.

[0002]

2. Description of the Related Art A cushion structure is known in which a high-melting main fiber material and a low-melting binder fiber material are blended, and the fiber intersections of the high-melting main fiber material are thermally fused with binder fibers. . For example, JP-A-58-31
No. 150 discloses 1 to 20 denier, fiber length 30 to 10
0 mm high-melting polyester staple, and a polyester staple having a melting point of 50 ° C. or more lower than the polyester staple, in a weight ratio of 90/10 to 50/50,
The invention describes a polyester fiber cushion material having a density of 0.005 to 0.15 g / cm ³ which is integrally fixed by melting low-melting-point polyester staples. However, according to the present invention, a polyester short fiber which is a main fiber and a heat-fused polyester short fiber having a melting point lower than the melting point of the polyester short fiber which is a binder fiber are mixed, and are integrally fixed by heat fusion of the binder fiber. However, it is merely a matter of fixing both, the adhesion is weak, the compression elasticity is inferior, the peel strength is low, and during use, sagging, causing a change in form, It is insufficient as a fiber cushion material.

[0003] Also, Patent Publication WO091 / 19032
In the publication, an inelastic polyester-based crimped short fiber aggregate is used as a matrix, a thermoplastic elastomer having a melting point 40 ° C. or more lower than the melting point of the polyester polymer constituting the short fiber aggregate is sheathed, and the inelastic polyester is a core. An elastic composite fiber is used as a binder, and both fibers are heat-fused. The density is 0.005 to 0.10 g / cm ³ and the thickness is 5
mm or more, wherein the elastic conjugate fiber present between the heat fusion points has at least one spindle-shaped node along its longitudinal direction. Have been. That is, it is described that by using a specific binder conjugate fiber and making the structure of the intersection point of the fibers specific, a material excellent in compression resilience, compression durability, and compression recovery can be obtained. . However, the present invention is unsatisfactory in that only specific types of binder fibers can be used, and general binder fibers cannot be used.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a fiber structure having excellent compression elasticity and peel strength, and a fiber structure having such characteristics can be prepared by using a general binder fiber. It is intended to be realized using.

[0005]

Means for Solving the Problems The present inventors diligently study a fiber structure which satisfies the above-mentioned problems, and the point of overcoming the above-mentioned problems as a fiber structure is that the main fiber and the binder fiber are entangled with each other. Focusing on that, the main fiber and the binder fiber both have crimps, and even after heat fusion, the binder fibers have a structure that entangles and fuses with the main fibers as fibers that maintain crimps, that is, It has been found that the object is achieved by configuring as follows. That is, the present invention mainly comprises a hollow conjugate fiber A having a three-dimensional crimp as a main fiber and a heat-fused conjugate fiber B as a binder fiber having a number of crimps larger than the number of crimps of the hollow conjugate fiber. Having a portion where the crimp of the fiber A is locally entangled with the crimp of the fiber A and fused to the crimp of the fiber A, and has a peel strength of 160 g / c.
m or more.

[0006]

According to the present invention, as shown in FIG. 1, a heat-fused conjugate fiber B having a crimp number larger than the number of crimps of the hollow conjugate fiber is added to the crimp of the hollow conjugate fiber A having a three-dimensional crimp. By forming a fiber structure in which the crimp is locally entangled and fused as the fiber maintaining the crimp, the compression elasticity of the fiber structure is high, and the peel strength can be high, This is an excellent fibrous structure that is free from sagging or significant change in shape during use as a cushion material. In particular, in the fiber structure of the present invention, the peel strength is as large as 160 g / cm or more. This is because the fiber structure is formed into various forms as a cushion material by a blade method, and the shape does not collapse. This is a very preferable characteristic in that it can be molded stably and accurately to an intended form.

The main fiber constituting the fiber structure of the present invention must be a hollow composite fiber A having a three-dimensional crimp. The crimp is 150-190 ° C, 1
Number of crimps (CPN-A) after dry heat treatment in 0 minutes is 8 to 1
8 pcs / inch is preferred. If the number of crimps is less than 8 / inch, the resulting fiber structure lacks rebound resilience and lacks bulk. Conversely, if the number of crimps exceeds 18 pcs / inch, the resulting fiber structure becomes too hard, which is not preferable. It has been found that a more preferable crimp is 10 to 15 pieces / inch.

The hollow composite fiber A has a hollow ratio of 13
~ 25% is preferred. A fiber having a hollow ratio of less than 13% is not preferable because the bulk of the fiber structure is insufficient. On the other hand, if the hollow ratio exceeds 25%, the hollow holes of the fibers are easily crushed, which is not preferable. It was found that a more preferable hollow ratio was 15 to 20%.

The fineness of the hollow composite fiber A is preferably 10 to 30 denier. If the hollow fibers have a fineness smaller than 10 denier, the resilience and bulk of the fiber structure will be insufficient. On the other hand, if the fineness exceeds 30 denier, the fibers, and thus the fiber structure, become too hard, which is not preferable. More preferred fineness is 12
It was found to be ~ 25 denier.

The fiber A having a three-dimensional crimp as described above and having a hollow ratio uses a composite polymer component (a) or (b) which causes a difference in shrinkage by heat treatment after the fiber formation as a constituent polymer, and is conventionally known. Can be manufactured in accordance with a conventional method using a hollow composite nozzle. As the configuration of the polymer components (a) and (b), for example, in the case of a polyester-based polymer, the difference in polymerization degree (the difference in intrinsic viscosity)
Combination of polyethylene terephthalate (PET) having PET and PET and copolyester (CO-PE)
S), a combination of PET and copolymerized polybutylene terephthalate (CO-PBT), and a combination of PET and
Various combinations of polymers can be used, such as combinations of styrene with other modified PES. However, in this case, the melting point of the modified polymer is lower than that of the original polymer due to modification such as copolymerization or modification. It is necessary to use a polymer having a melting point higher than the melting point of the fusion-side polymer, and desirably a modified polymer having a melting point higher by at least 30 ° C. than the melting point of the heat-fusion side polymer.

The heat-fused conjugate fiber B constituting the binder fiber of the present invention serves as a binder component of the hollow conjugate fiber A as the main fiber and maintains crimp even after the heat-sealing. It is necessary that the fibers maintain their shape, and it is desirable that the fibers have the following properties. That is, first, since the heat-fused conjugate fiber B maintains the fiber form even after the heat-sealing, the polymer component (c) serving as the core component and the melting point of the polymer component (c) are determined. Either an eccentric core-sheath type composite fiber composed of a polymer component (d) serving as a sheath component having a melting point lower by at least 40 ° C. or a side-by-side type of polymers (c) and (d) having a similar melting point difference And the melting point of the polymer component (d) on the heat fusion side is 30% lower than the melting point of the polymer component on the low melting point side of the hollow composite fiber A as the main fiber.
It is preferable that the relationship has a melting point lower by at least ° C. The difference in melting point between both components (c) and (d) of the heat-fused conjugate fiber B is 40
If the relationship is lower than ° C., the properties of the polymer component (c) that maintains the fiber properties will be impaired at the time of heat fusion, which is not preferable. This relationship is also the same for the relationship between the heat-fusible conjugate fiber and the hollow conjugate fiber A as the main fiber. If the melting point difference of the melting point of the heat-fusion side polymer component (d) becomes close to 30 ° C. or less, the fiber properties of the hollow composite fiber A side during the heat fusion are undesirably impaired.

The crimp of the heat-fused conjugate fiber B is 150 to 19
Number of crimps after dry heat treatment at 0 ° C for 10 minutes (CPN-B)
And the number of crimps (CPN) of the hollow composite fiber A under the same conditions
−A) and ΔCPN [= (CPN−B) − (CPN−
A)] is within a range of 5 or more and 20 or less, and it has been found that a crimped one having a larger number of crimps than the hollow composite fiber A is preferable. If ΔCPN is lower than 5, the peel strength of the obtained fiber structure is low, and the rebound resilience is low. On the other hand, if ΔCPN is higher than 20, the resulting fiber structure becomes hard, which is not preferable.
More preferably, 8 ≦ ΔCPN ≦ 15.

The form of the heat-fused conjugate fiber B having the above characteristics is preferably an eccentric core-sheath type or side-by-side type conjugate fiber as described above.
It is more preferable that the composite component (c) and (d) be of an eccentric core-sheath type in which the surface area of the fused portion is large in terms of difficulty in peeling.

The ratio of the composite component constituting the heat-fused conjugate fiber B is 0.3 ≦ (d) / (d) for the polymer component (c) on the high melting point side and the polymer component (d) on the heat fusion side.
It is preferable to fall within the range of {(c) + (d)} ≦ 0.7. When this ratio is smaller than 0.3, the amount of the polymer component (d) on the heat-sealing side is reduced, and the peel strength as a fiber structure is low. When the ratio of the polymer component (d) on the heat-fusion side exceeds 0.7, the heat-fused conjugate fiber B is unlikely to exhibit crimp, and the rebound resilience is low. . It has been found that the composite ratio is more preferably in the range of 0.4 or more and 0.6 or less.

When the heat-fused conjugate fiber B is an eccentric core-sheath type conjugate fiber, the eccentricity x / R at which the core component (c) and the sheath component (d) are eccentric is 0.05 or more and 0 or more. .55 or less. Here, x / R means that the cross-sectional radius of the entire conjugate fiber including the core portion in the sheath portion is R, and the distance from the center point of the cross-section of the conjugate fiber to the center point of the core component is x. It is. When the eccentricity x / R is smaller than 0.05, the crimp of the heat-fused conjugate fiber B is less likely to be exhibited, and thus the resilience of the fiber structure is reduced. In addition, this eccentricity x / R is 0.
Even if it is larger than 55, the crimping of the heat-fused conjugate fiber B becomes difficult to occur, and the resilience of the fiber structure becomes low.
It was found that more preferably 0.10 ≦ d / R ≦ 0.5.

The fineness of the heat-fused conjugate fiber B is preferably 3 to 10 denier. If the fineness is less than 3, the rebound resilience as a fiber is low, and if it is more than 10, the peel strength as a fiber structure is low and hard, which is not preferable. More preferably 4 to 8
It turned out to be in the denier range.

The polymer component (d) on the heat fusion side of the heat fusion composite fiber B may be an amorphous polymer or a crystalline polymer. As the amorphous polymer, in the case of a polyester type, for example, a PET type P modified with isophthalic acid and ethylene oxide bisphenol sulfone is used.
ES is mentioned, and as the crystalline polymer, for example, isophthalic acid-modified polybutylene terephthalate is mentioned. The type of the polymer of the heat-fusion side polymer component (d) may be changed according to the type of the polymer component (c) on the high melting point side. The polymer is selected so that it melts at a temperature at least 40 ° C. below its softening point.

The heat-fused conjugate fiber B can also be produced by using a conjugate polymer component as described above and using a conventionally known conjugate nozzle according to a conventional method.

The fiber structure of the present invention is prepared by blending the hollow composite fiber A as the main fiber and the heat-fusible composite fiber B as the binder fiber, and using a card to form a web by a conventional method. 1. The electron micrograph of FIG. 1 having a portion in which the crimp of the heat-fused conjugate fiber B is locally entangled with the three-dimensional crimp of the hollow conjugate fiber A and heat-bonded. It has the structure shown by.

The fiber structure of the present invention has a density of 0.01 to 0.10 for its use as a cushion material.
g / cm ^3, and its peeling strength needs to be 160 g / cm or more. If the density is less than 0.01 g / cm ³ , the cushion material is too soft and inferior in workability.
If the density is more than 10 g / cm ³ , the hardness is too hard, and both have poor cushioning properties, which is not preferable.

In order to obtain such density and peel strength, the mixing ratio of the hollow composite fiber A and the heat-fusible composite fiber B is
A / B = 50-90 / 50-10 is preferred. When A / B is smaller than 50/50, the hardness of the fibrous structure is too hard and the cushioning property is insufficient. A / B is 90
If the ratio is larger than / 10, the hardness of the fibrous structure is too soft, the peel strength is insufficient, and the workability is poor.

[0022]

EXAMPLES The present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto. In addition,
The peel strength of the fibrous structure in the present specification is a value obtained by measuring the thermal adhesive tear strength of a molded cushion material (heat-fused fibrous structure) according to JASO-M304 using an Instron universal testing machine. . The hardness at the time of compression of 25% or 50% means a load required for compression at the time of compression of 25% or 50% according to a hysteresis curve (strain amount-load curve) by an Instron type universal testing machine. Means a repulsion force (hardness) at the time of sinking, and is a value according to JIS-K6401. Furthermore, the recovery rate after compression means that the molded cushion material is compressed, and the compression is repeated 80,000 times using a device capable of repeating the range between the original thickness and the thickness of 50%. The thickness after measurement is measured, and the ratio of the thickness to the original thickness is expressed as a percentage, which is a value according to JIS-K6401.

Example 1: Using a spinning nozzle for spinning hollow side-by-side type conjugate fiber, using both PET chips having intrinsic viscosity [η] of 0.72 and 0.50,
The hollow composite fiber A was manufactured according to a conventionally known method so that the weight ratio was 1: 1. This hollow composite fiber A
Has a single fiber thickness of 18 denier, a fiber length of 64 mm,
The hollow ratio is 20%, the melting point is 260 ° C., and it has a three-dimensional crimp,
The number of crimps was 8 pieces / inch, and the number of crimps (CPN-A) after dry heat treatment at 190 ° C. for 10 minutes was 12 pieces / inch.

Separately, a polymer chip obtained by copolymerizing an acid component obtained by mixing terephthalic acid and isophthalic acid at 70/30 (mol%) with butylene glycol is used as the sheath component, and the intrinsic viscosity [η] is used as the core component. Is 0.72 P
An eccentric core-sheath type heat-fused conjugate fiber B was manufactured using an ET chip according to a conventionally known method so that the weight ratio between the two was 1: 1. The heat-fused conjugate fiber B has a monofilament thickness of 6 denier, a fiber length of 64 mm, a three-dimensional crimp, a number of crimps of 8 / inch, a dry heat of 190 ° C.,
The crimp number (CPN-B) after the treatment for 0 minutes was 21 pcs / inch, and the melting point of the fusion component was 170 ° C.

70% by weight of the hollow composite fiber A and 30% by weight of the heat-fusible composite fiber B were mixed, and a web was obtained using a card by a conventional method. This was laminated and placed in a flat mold, and heat-treated at 190 ° C. for 10 minutes to obtain a fibrous structure. When this fiber structure was observed with an electron microscope,
It has the structure shown in FIG. 2 and has a crimp of the hollow composite fiber A having a three-dimensional crimp and a portion where the crimp of the heat-fused composite fiber B is locally entangled and fused. Was observed. This fiber structure has a density of 0.031 g /
cm ³ , peel strength 190 g / cm, hardness at 25% compression 40 kg, hardness at 50% compression 130 kg, compression residual strain 27%, recovery rate after repeated compression 91% It was very good as a cushion material such as strong and compressible.

Example 2 Using a spinning nozzle for spinning hollow side-by-side type conjugate fibers, a PET chip having an intrinsic viscosity [η] of 0.63, terephthalic acid and isophthalic acid at 70/30. (Mol%), a PES chip having an intrinsic viscosity [η] of 0.67 obtained by polymerizing an acid component mixed with ethylene glycol, and using a PES chip having a limiting viscosity [η] of 0.67, so that the weight ratio between the two becomes 1: 1. According to the method described above, hollow composite fiber A was produced. The hollow conjugate fiber A has a single fiber thickness of 15 denier, a fiber length of 64 mm, and a hollow ratio of 16
%, A melting point of 260 ° C., a three-dimensional crimp, the number of crimps is 10 / inch, the number of crimps (CPN-A) after dry heat treatment at 150 ° C. for 10 minutes is 14 / inch. Was.

Separately, a polymer chip obtained by copolymerizing an acid component obtained by mixing terephthalic acid and isophthalic acid at a ratio of 55/45 (mol%) with butylene glycol is used as a sheath component, and an intrinsic viscosity [η] is used as a core component. Is 0.72 P
Using an ET chip, a side-by-side type heat-fused conjugate fiber B was manufactured according to a conventionally known method so that the weight ratio between the two becomes 1: 1. The heat-fused conjugate fiber B has a single fiber thickness of 4 denier and a fiber length of 64 m.
m, a three-dimensional crimp, the number of crimps is 6 / inch, the number of crimps (CPN-B) after dry heat treatment at 150 ° C. for 10 minutes is 2
The melting point of the fused component was 150 ° C. at 8 pieces / inch.

80% by weight of the hollow composite fiber A and 20% by weight of the heat-fusible composite fiber B were mixed, and a web was obtained using a card by a conventional method. This was laminated, placed in a flat mold, and heat-treated at 170 ° C. for 10 minutes to obtain a fibrous structure. When this fiber structure was observed with an electron microscope, it had the structure shown in FIG. 3, and the crimp of the heat-fused conjugate fiber B was locally added to the crimp of the hollow conjugate fiber A having a three-dimensional crimp. It was observed that it had a portion that was entangled and fused. This fiber structure has a density of 0.037.
g / cm ³ , peel strength 210 g / cm, hardness at 25% compression 44 kg, hardness at 50% compression 190 kg,
Compression residual strain of 43% and recovery after repeated compression of 85
%, A material excellent in peeling strength, hard as a cushion material, and excellent in resilience was obtained.

Comparative Example 1: P having an intrinsic viscosity [η] of 0.65
Using ET chips, hollow composite fibers A ′ having three-dimensional crimps were produced according to a conventionally known method. The hollow conjugate fiber A ′ has a single fiber thickness of 12 denier and a fiber length of 6
4 mm, hollow ratio 30%, melting point 260 ° C., three-dimensional crimp, the number of crimps is 8 / inch, dry heat 150 ° C., 10 mm
The number of crimps (CPN-A ') after the minute treatment was 10 pcs / inch. On the other hand, terephthalic acid and isophthalic acid
A polymer chip obtained by polymerizing an acid component and ethylene glycol mixed at 45 (mol%) was used as a sheath component, and a PET chip having an intrinsic viscosity [η] of 0.72 was used as a core component. A core-sheath type heat-fused conjugate fiber B ′ according to a conventionally known method so as to be 1: 1.
Was manufactured. The heat-fused conjugate fiber B 'has a single fiber thickness of 4 denier, a fiber length of 64 mm, a mechanical crimp, a number of crimps of 7 / inch, a dry heat of 150 ° C., and a treatment after 10 minutes. Had a crimp number (CPN-B ') of 8 / inch and a melting point of the fused component of 150 ° C. 70% by weight of the hollow composite fiber A 'and 30% of the heat-fusible composite fiber B'
% By weight, and a web was obtained using a card by a conventional method. These were laminated and placed in a flat mold, and heat-treated at 150 ° C. for 10 minutes to obtain a fibrous structure.

When this fiber structure was observed with an electron microscope, the structure shown in FIG. 4 was shown. As can be seen in this micrograph, in the fibrous structure of this example, there is no portion where the crimp of the heat-fused composite fiber is locally entangled with the crimp of the hollow composite fiber having a three-dimensional crimp and is fused. It is observed that they are simply crossed and fused. This fiber structure has a density of 0.042 g / cm ³ and a peel strength of 63 g / cm ³ .
cm, hardness at 25% compression is 26 kg, hardness at 50% compression is 142 kg, compression residual strain is 45%, recovery rate after repeated compression is 83%, peel strength, compression recovery, etc. are low. Was not very good.

The fibrous structure of the present invention is suitable for a cushion material in terms of hardness, and particularly has a large recovery rate after repeated compression and excellent peeling strength, and is used for furniture, beds, and various other seats. It is suitable as a cushion material or the like.

[Brief description of the drawings]

FIG. 1 is an electron micrograph instead of a drawing, showing the fiber morphology and the entangled state of the surface of the fiber structure of the present invention.

FIG. 2 is an electron micrograph instead of a drawing, showing a fiber morphology and an entangled state thereof on the surface of the fiber structure of the example of the present invention.

FIG. 3 is an electron micrograph instead of a drawing, showing the fiber morphology and the entangled state of the surface of the fiber structure of the example of the present invention.

FIG. 4 is an electron micrograph instead of a drawing, showing a fiber form and an entangled state thereof on the surface of a fiber structure of a comparative example.

Claims (1)

(57) [Claims] 1. A fiber structure mainly composed of a hollow composite fiber A having a three-dimensional crimp and a heat-fused composite fiber B having a number of crimps larger than the number of crimps of the hollow composite fiber, The crimp of fiber A has a portion that is locally entangled with the crimp of fiber B and is fused, and the peel strength is 160 g / c.
m or more.