JP3454363B2 - Fiber structure and manufacturing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber structure in which a non-elastic crimped short fiber is used as a matrix, and a contact point is thermally bonded by an elastic composite fiber made of a thermoplastic elastomer to form a network structure. . Further, the present invention relates to a recyclable fibrous structure having excellent cushioning properties, excellent sag resistance and heat resistance durability when used as a cushioning material for furniture, beds, trains, automobiles and the like.

[0002]

2. Description of the Related Art Currently, it is used as a cushion material for furniture, beds, trains, automobiles, etc., using urethane foam, non-elastic crimped fiber wadding,
In addition, resin cotton or hard cotton to which non-elastic crimped fibers are adhered is used.

However, although urethane foam has a good durability as a cushioning material, it has a large feeling of being attached to a floor, is poor in moisture permeability and water permeability, and has a heat storage property. The addition of a halide is required to impart the properties, and the problem of poisoning due to the generation of a large amount of toxic gas in case of fire and damage to the incinerator when it is incinerated due to the difficulty of recycling, and the cost for removing the toxic gas are high. Hang up. For this reason, landfilling has become more frequent, but it is difficult to stabilize the ground, and there is a problem that landfilling sites are limited and costs increase. Further, although it has excellent processability, it also has a problem of pollution of chemicals used during manufacturing. In addition, since the fibers are not fixed to each other in the polyester fiber wadding, the form may collapse during use, the fibers may move, and the crimp may cause the deterioration of bulkiness and elasticity. .

As a resin cotton in which polyester fibers are adhered with an adhesive, for example, a rubber-based adhesive is used, Japanese Patent Application Laid-Open No.
0-11352, JP-A 61-141388, JP-A 61-141391 and the like. Further, as a method using urethane, there is JP-A-61-137732. These cushion materials have poor durability,
In addition, there are problems such as not being able to recycle, complexity of processability and pollution of chemicals used during manufacturing.

Polyester hard cotton, for example, JP-A-58-3
1150, JP-A-2-154050, JP-A-3-220354, etc., but since an amorphous polymer having a brittle adhesive component of the heat-bonding fiber used is used (for example, JP-A-58). -136828, Japanese Patent Application Laid-Open No. 3-
However, there is a problem in that durability is poor such that the bonded portion is brittle and the bonded portion is easily broken during use and the form and elasticity are reduced. As an improved method, a method of entanglement treatment has been proposed in Japanese Patent Laid-Open No. 4-245965, but there is a problem that the brittleness of the bonded portion is not solved and the elasticity is largely reduced. In addition, there is complexity during processing. Further, there is a problem that the bonded portion is hard to be deformed and soft cushioning is hard to be imparted. Therefore, a heat-bonding fiber using a polyester elastomer which is soft and recovers even if it is deformed is disclosed in JP-A-4-240219, and a cushion material using the fiber is disclosed in WO-91 / 19032. Proposed. The adhesive component used in this fiber structure contains 50 to 80 mol% of terephthalic acid in the acid component of the hard segment of polyester elastomer, and the content of polyalkylene glycol as the soft segment is 30 to 50% by weight. If the melting point is 180 ° C. or lower as the composition of other acid components if the content of% is limited,
Since it is recognized that it is the same as the fiber described in the publication, it contains isophthalic acid and the like to increase the non-crystallinity, and the low melt viscosity improves the formation of the heat-bonded portion to form an amoeber-like bonded portion. However, since it is easily plastically deformed, there is a problem that the heat resistance and compression resistance are lowered.

[0006]

DISCLOSURE OF THE INVENTION The present invention has improved the above-mentioned problems of the prior art, and has excellent cushioning property, sag property,
An object of the present invention is to provide a recyclable fibrous structure which has excellent heat resistance and durability, becomes a cushioning material that does not easily get damp when sitting and is comfortable to sit on.

[0007]

Means for Solving the Problems As a result of intensive studies for achieving the above object, the present inventors have found that a composite fiber made of a thermoplastic elastomer and having elasticity.
The present inventors have found that the object can be achieved by forming a black structure and arrived at the present invention. That is, the present invention is a fiber structure in which a non-elastic crimped short fiber (A) and an elastic composite fiber (B) are three-dimensionally mixed, and the elastic composite fiber (B) is a non-elastic crimped short fiber ( 4) from the melting point of the polymer forming A)
Thermoplastic elastomer (C) having a melting point lower than 0 ° C
And a thermoplastic elastomer (D) having a melting point higher than that of the thermoplastic elastomer by 30 ° C. or more, and the thermoplastic elastomer (C) is exposed on the surface of the composite fiber at least ½ or more, and the fiber (A) And fibers (B) or fibers (B) and fibers (B) at three-dimensionally formed contact points are scattered by heat fusion and have a density of 0.005 to 0.10 g / cm ³ And a thermoplastic elastomer (C) having a melting point at least 40 ° C. lower than the melting points of the fiber structure and the non-elastic crimped short fibers and the polymer constituting the non-elastic crimped short fibers in the heat-adhesive component. A thermoplastic elastomer (D) having a melting point that is at least 30 ° C. higher than that of the adhesive component, and the former (C) is mixed with an elastic composite fiber exposed at least ½ or more on the fiber surface, opened, and expanded. After forming three-dimensional fiber contact points between the functional composite fibers and between the composite fibers and the non-elastic crimped short fibers, heat treatment is performed at a temperature that is at least 10 ° C. higher than the melting point of the thermoplastic elastomer (C) serving as a heat-adhesive component. The method for producing a fiber structure is characterized in that at least a part of the fiber contacts are heat-bonded.

In the fibrous structure of the present invention, an elastic composite fiber composed of a thermoplastic elastomer serving as a heat-adhesive component and a thermoplastic elastomer supporting a network structure is contained in a matrix of inelastic crimped fibers. And a contact point with the non-elastic crimped short fibers are bonded by heat fusion to form a three-dimensional network structure composed of an adhesive point having good elasticity and a thermoplastic elastomer having elasticity.
Since the non-elastic crimped fibers of the matrix are connected by the adhesive points having good stretchability and the three-dimensional network structure, the adhesive points and the three-dimensional network structure can be deformed without being destroyed even when subjected to a large deformation. When the strain is removed, the elasticity of the elastomer is developed and the original structure can be restored. The essential difference between the present invention and WO 91/19032 is that the present invention forms a three-dimensional network structure with elastic composite fibers composed of a thermoplastic elastomer. In the present invention, since the network is formed by the elastic composite fiber, even if it is extremely stretched, it is stretched by the entire three-dimensional network structure of the elastic composite fiber which is excellent in stretchability, and is a non-elastic crimped fiber. Although it does not stretch significantly, and therefore the bonding points are not destroyed, in WO91 / 19032, the bonding points are linearly connected by a fiber made of an inelastic material, and when subjected to a large deformation, the fiber itself is stretched and distorted. In response, a large force is concentrated on the adhesion point and the structure is destroyed, or there are a part where the adhesive component is concentrated in a spindle shape and a part where the adhesive component flows out and only the core component remains. The part is a thin non-elastic fiber, and since it is not sufficiently heat-stretched, its mechanical properties are inferior, and the fiber itself may be broken due to stress concentration. Therefore, the fiber structure of the present invention is more resistant than the fiber structure described in WO91 / 19032 from the point that the entire fiber structure is connected by elastic composite fibers having elasticity of elastomer in a three-dimensional network form. The sag, durability, and cushioning properties are excellent.

The fiber structure of the present invention has a density of 0.005 to 0.005.
It is 0.1 g / cm ³ . If the density is 0.1 g / cm ³ or more, the fiber density becomes excessively high and the thermoplastic elastomer
They are not suitable as a cushioning material because they tend to be fused to each other in an excessively dense manner, the elasticity in the thickness direction is significantly reduced, the air permeability is reduced, and they tend to become stuffy. On the other hand, this density is 0.
If it is less than 005 g / cm ³ , the number of non-elastic crimped short fibers forming a matrix is reduced and the repulsive force as a cushioning material is lost, which is not preferable. In this respect, JP-A-5
It is different from the two-dimensional dense structure described in JP-A 8-197312 or the like for the purpose of reinforcing the tape, ribbon, sheet and the like and easiness of bending.

The preferable content of the elastic composite fiber forming the stretchable three-dimensional network structure in the fiber structure of the present invention is 10% by weight or more and 70% by weight or less, more preferably 20% by weight. % To 50% by weight. If it is less than 5% by weight, the three-dimensional network structure is reduced, and the sag resistance, durability and cushioning property are deteriorated, which is not preferable. If it is 70% by weight or more, the bulkiness and the repulsive force derived from the rigidity of the non-elastic crimped fiber are lowered, and the feeling of floor attachment is increased, so that it is not suitable as a cushioning material.
Further, since the cushion material is a material which is compressed and repelled in the thickness direction, it is preferably at least 5 mm or more, and more preferably 10 mm or more in order to exert its performance.

The non-elastic crimped short fibers (A) of the matrix constituting the fiber structure of the present invention are not particularly limited as long as they can be regenerated by using a thermoplastic polymer.
Considering mechanical properties, heat resistance properties, generation of toxic gas during combustion, etc., preferably polyester fiber, for example,
Polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycyclohexylene dimethylene terephthalate (PCHDT), polybutylene terephthalate (PBT), polyarylate, and the like, and combinations thereof. Spinning polymer selected from polymerized polyester,
Stretched and crimped crimped short fibers, or at the time of spinning, two types of polymers having different thermal properties from the above polymers are combined and spun into a composite, or a latent crimping ability is imparted by using an asymmetric cooling method, It is a crimped short fiber that is subjected to mechanical crimping as necessary after stretching and / or as it is to develop a three-dimensional crimp.
The fineness, fiber cross-sectional shape, mechanical properties and the like of these polyester crimped short fibers are determined depending on the desired application, but the fineness is usually 3 to 500 denier, preferably 4 to 200.
Denier. The cross-sectional shape is preferably a hollow cross section or a polygonal or multilobe hollow irregular cross section. Among them, the modulus is high even after being formed into a structure (the settling of crimp due to plastic deformation due to strain at room temperature and heating is reduced), and in PET, for example, the initial tensile resistance is preferably 30 g / denier. -More, more preferably 40 g / denier or more, and a cross-sectional shape with a large cross-sectional secondary moment,
It is particularly preferable to use one having a round cross-section ratio of 1.3 times or more, more preferably 1.5 times or more, since the anti-compression property and the heat and sag resistance can be improved. Also, it is particularly preferable to use fibers having a three-dimensional crimp, preferably those having a crimping degree of 20% or more, more preferably 25% or more, since the sag resistance and cushioning property are improved. The reason for this is
The non-elastic crimp short fibers having a three-dimensional crimp with heat-resistant sag resistance and anti-compression property and the elastic composite fibers having elasticity are heat-bonded to each other to form a three-dimensional network structure having elasticity. Therefore, even if a large force is applied in any direction or a large deformation is applied, each elastic composite fiber is gradually deformed and the force or strain can be absorbed by the entire network structure, so that the matrix inelastic winding can be absorbed. Use of crimped fibers
Heat resistance and cushioning property are improved by significantly reducing the fatigue resistance.

The elastic composite fiber (B) forming the three-dimensional network structure having excellent stretchability, which constitutes the fiber structure of the present invention, supports the thermoplastic elastomer and the network structure which are the heat-adhesive components. It is formed with a thermoplastic elastomer. The thermoplastic elastomer as a heat-adhesive component has a melting point of 40 ° C. from the polymer constituting the non-elastic crimped short fibers.
Above, it is particularly preferable that the temperature is lower than 60 ° C. If the melting point difference is less than 40 ° C., the preferable heat treatment temperature during fusion processing is at least 10 ° C. higher than the melting point of the thermoplastic elastomer, and more preferably 20 ° C. higher. On the other hand, it becomes a harsh temperature,
The crimp of the non-elastic crimped short fibers is caused and the mechanical properties are deteriorated, so that the properties as a fiber structure are deteriorated. In addition, a thermoplastic elastomer that forms a network structure
If the adhesive points are formed by heat treatment at a temperature higher than the melting point of, the elastic composite fiber cannot be melted to form a network structure (therefore, the thermoplastic elastomer supporting the network structure is a heat bonding component). The melting point of the thermoplastic elastomer is at least 30 ° C. higher than the melting point of the thermoplastic elastomer, preferably 40 ° C. or higher.) The melting point of the thermoplastic elastomer serving as the heat-adhesive component is preferably 140 ° C. or higher and 190 ° C. or lower. Further, the thermoplastic elastomer, which is a heat-adhesive component, does not occupy at least ½ or more of the fiber surface, the adhesive points are reduced, and an effective stretchable network structure cannot be formed. It is preferable that the heat-adhesive component occupy the entire surface of the fiber because it can be heat-bonded at all of the contacts and an effective elastic network structure can be formed. Further, in order that the thermoplastic elastomer supporting the network structure has a melting point at least 30 ° C. higher than the melting point of the thermoplastic elastomer as a heat-adhesive component, preferably 40 ° C. or more, the soft segment of the elastic component is When the content is reduced, the deformed network structure can be easily restored to the original structure because it is wrapped with the thermoplastic elastomer of the heat-adhesive component having a good stretch recovery property. In such a case, it is preferable that the thermoplastic elastomer on the surface of the elastic composite fiber in the structure is kept in a state where the fluidity thereof is slightly insufficient. The composite ratio of the heat-adhesive component of the thermoplastic elastomer constituting the elastic composite fiber and the component supporting the network structure is 20/80 to.
A range of 70/30 is suitable. The form of the elastic composite fiber may be a side-by-side type, but is preferably a sheath-core type for the reasons described above. Further, it is more preferable to use a hollow sheath core type capable of improving bending rigidity because the cushioning material can have high elasticity.

The composition of the thermoplastic elastomer is not particularly limited as long as there is no problem in practical use, but the hard segment is a highly crystalline one, and the soft segment is a polyether or polyester having a relatively large molecular weight. It is preferable to use a block copolymer because the elastic composite fibers forming the heat-bonded portion and the three-dimensional network structure have good stretchability and heat resistance, and the heat resistance and sag resistance of the cushioning material are improved. It is a usage form. A more preferable use form of the present invention is that when the non-elastic crimped fiber is made of polyester, the thermoplastic elastomer is made of a polyester system having good adhesiveness. As the polyester elastomer, a polyester ether block copolymer having a thermoplastic polyester as a hard segment and a polyalkylenediol as a soft segment, or a polyester ester block copolymer having an aliphatic polyester as a soft segment A polymer can be illustrated. More specific examples of the polyester ether block copolymer include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, naphthalene 2.6 dicarboxylic acid, naphthalene 2.7 dicarboxylic acid, and diphenyl 4.4'dicarboxylic acid. 1,
A cycloaliphatic dicarboxylic acid such as cyclohexanedicarboxylic acid, succinic acid, adipic acid, aliphatic dicarboxylic acid such as sebacic acid dimer acid, or at least one dicarboxylic acid selected from ester-forming derivatives thereof,
Aliphatic diols such as 1.4 butanediol, ethylene glycol, trimethylene glycol, tetremethylene glycol, pentamethylene glycol and hexamethylene glycol, 1.1 cyclohexane dimethanol 1
A cycloaliphatic diol such as 4-cyclohexanedimethanol, or at least one diol component selected from ester-forming derivatives thereof, and an average molecular weight of about 3
Tertiary block copolymer composed of at least one of polyalkylenediol such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide-propylene oxide copolymer, etc. Is. The polyester ester block copolymer is a ternary block copolymer composed of at least one dicarboxylic acid, diol and at least one aliphatic polyester such as polylactone having an average molecular weight of about 300 to 3,000. Considering thermal adhesion, hydrolysis resistance, stretchability, heat resistance, etc., the dicarboxylic acid may be terephthalic acid, or naphthalene 2.6.
A ternary block copolymer of 1,4 butanediol as the dicarboxylic acid and the diol component and polytetramethylene glycol as the polyalkylenediol is particularly preferable.

As the polyester constituting the hard segment has better crystallinity, it is less likely to be plastically deformed, and the heat resistance and sag resistance is improved. Further crystallization treatment after melt thermoforming will further improve the heat resistance and sag resistance. The reason for this is not clear, but when the content of terephthalic acid or naphthalene 2.6 dicarboxylic acid is high, the endothermic peak appears more clearly at a temperature below the melting point in the melting curve by a differential scanning calorimeter (DSC). To do. By analogy with this, it is considered that pseudo-crystallization-like cross-linking points are formed and the heat resistance and sag resistance are improved. The preferred amount of terephthalic acid or naphthalene 2.6 dicarboxylic acid is 90 mol% or more, more preferably 100 mol% as an acid component. If the amount of terephthalic acid or naphthalene 2.6 dicarboxylic acid is less than 90 mol, the crystallinity is poor, and thus plastic deformation is likely to occur and the heat resistance and sag resistance are poor. Even if a crystallization treatment is further performed after the melt thermoforming, the heat resistance and sagging resistance are difficult to improve.

Thermoplastic gallium constituting the composite fiber of the present invention
Stoma is 1-4 butanedio- as a glycol component.
Block and polytetramethylene glycol
And copolymerization of polytetramethylene glycol
It is preferable that the amount is 10% by weight or more and 80% by weight or less.
Yes. The recoverability derived from rubber elasticity is polytetramethylene
It is proportional to the amount of copolymerization of the liquor. At the same time the melting point and heat resistance
It will decrease. Copolymerization of polytetramethylene glycol
If the amount is less than 10% by weight, the recoverability due to rubber elasticity is considerably high.
It is decreasing. On the other hand, if it exceeds 80% by weight, the melting point will decrease.
Inferior heat resistance and development of adhesiveness, resulting in elastic
It is difficult to uniformly spread and spread synthetic fibers, so it is preferable.
Not good. Thermoplastic elastomer, which is the thermoadhesive component of the present invention
The preferred composition of the mer (C) is polytetramethylene glyco
-Copolymerization amount of 40 wt% or more and 70 wt% or less,
It is preferably 50% by weight or more and 60% by weight or less. Heat resistance
In order to maintain the sex, increase the size of the repeating unit of the hard segment.
If it is hardened, the recovery due to rubber elasticity will also be retained,
Increase the average molecular weight of Litetramethylene glycol
It is necessary, but if it is made too large, compatibility will be lost and polymerization will proceed.
Therefore, it is necessary to set an appropriate molecular weight. Good
A preferable average molecular weight is 500 or more and 5000 or less, and particularly preferable.
It is preferably 1000 or more and 3000 or less. 5000 or more
If used, the characteristics at low temperatures will deteriorate significantly, so it is preferable.
Not good. On the other hand, the structure that supports the three-dimensional network structure
The thermoplastic elastomer (D), which is a component, has an appropriate elasticity.
In addition, it has a higher melting point than the heat-adhesive component and is a machine that retains its shape.
No. No. is also required, so the repeat unit of the hard segment is large.
In order to maintain the combability and recoverability derived from rubber elasticity,
Relationship between average molecular weight of tetramethylene glycol and compatibility
It is preferable to use a high molecular weight product of
Good The copolymerization amount of polytetramethylene glycol is 10
% To 50% by weight, more preferably 20% by weight
It is above 40% by weight. In addition, the preferred in the present invention
The molecular weight of a new polyester ether copolymer is 40 ° C.
Phase measured in a mixed solvent of ethanol / tetrachloroethane
Viscosity (η _{sp / c}) Is heat with a high soft segment content
The adhesive component is 1.8 or more. Below 1.8, flow
The adhesive property is improved and the bond point forming property is improved, but the bond point is recovered.
Three-dimensional network formed by the elastic composite fiber having poor elasticity
The plastic deformation of the connection points of the
It is not preferable because it has poor sag and durability. Thermal adhesive component
A more preferable relative viscosity is 2.0 or more and 2.5 or less.
When it is 2.5 or more, the fluidity is a little when heat-bonded at 200 ° C or less.
The adhesive spot formation may be insufficient.
It On the other hand, the component that supports the three-dimensional network structure is
The relative viscosity is slightly low due to the small amount of soft segment.
It The preferred relative viscosity is 1.0 or more, more preferably
By setting it to 1.5 or more, recoverability and toughness can be imparted.
It

In a more preferred embodiment of the present invention, since the copolymer component of polytetramethylene glycol is large in the elastomer component of the elastic composite fiber, the molecular weight is remarkably reduced by thermal decomposition at a high temperature of 250 ° C. or higher. . Therefore, in the present invention, the antioxidant is positively contained in an amount of preferably 1% by weight or more, more preferably 2% by weight or more and 5% by weight or less. With such a composition, spinning at high temperature is also possible, and the hard segment of the component supporting the three-dimensional network structure has a high melting point with high crystallinity, such as terephthalate or naphthalate as the acid component. It is possible to use a large number of repeating units using ethylene glycol, butanediol, cyclohexylene dimethanol, etc. as the glycol component as the glycol component, and the elastic tertiary fiber formed by the elastic composite fiber. The original network structure can have heat resistance and sag resistance. Furthermore, it is possible to perform heat-bonding in air at a high temperature of 200 ° C. or higher by using an elastomer having a high melting point and a high molecular weight, and it is possible to suppress the decrease in the molecular weight at this time. Thus, since the molecular weight of the elastomer can be kept high, the fibrous structure of the present invention has not only improved heat resistance and sag resistance but also markedly improved recovery by rubber elasticity. Preferred antioxidants used in the present invention include:
There are conventionally known hindered phenol compounds and hindered amine compounds. However, a hindered phenol compound which emits no toxic gas upon combustion is particularly preferable. The preferred polyester ether copolymer constituting the fiber assembly of the present invention can be obtained by a conventionally known method such as JP-A-55-120626, but the antioxidant is added in a large amount during the polymerization. Then, it sublimates to cause troubles such as clogging of the polymerization can and the effect of addition is drastically reduced. Therefore, it is preferable to knead under pressure after the polymerization.

The uniform dispersion of the elastic composite fibers in the non-elastic crimped short fiber matrix can be achieved by the following means. That is, the elastic composite fiber of the present invention that forms a three-dimensional network structure with an adhesive point having excellent elasticity can be obtained by spinning into a conventionally known method, for example, a side-by-side type or a sheath-core type structure. it can. If a three-dimensional crimp is developed during processing up to thermoforming, the elastomer is particularly sticky and the yarn has a high friction coefficient, which is a key factor.
When opening, the opening tends to be defective. For this reason, it is preferable to eliminate mechanical crimps that are easy to open. Mechanical crimps can be used as long as the number of crimps is 5 to 30 ridges / inch and the crimp ratio is in the range of 5 to 30%, but preferably 10 to 25 ridges / crimp.
Inch, crimp ratio is 10 to 25%. It is particularly preferable to use an oil agent having a low friction coefficient as the finishing oil agent. Therefore, it is not preferable to use the three-dimensional crimped fiber having a low shrinkage by exhibiting the latent crimping ability as in JP-A-4-240219. The preferred drawing conditions for obtaining the composite fiber having the more preferred fiber aggregate structure of the present invention are as follows.
Stretching at 70 ° C. at 0.8 to 0.9 times the breaking stretch ratio, and then tension heat treatment at 100 ° C. or less to reduce the shrinkage ratio,
It can be obtained by applying a mechanical crimp and supplying and cutting to a cutter with a low tension so that the mechanical crimp does not extend. If the shrinkage is high, the fibrous structure after molding tends to be delaminated, so it is preferable to reduce the shrinkage ratio as much as possible. Opening /
Mixing is carried out by an ordinary card, and the obtained web is spread / mixed and dispersed to form three-dimensional fiber contact points between elastic composite fibers and between composite fibers and non-elastic crimped short fibers. At least some of the fiber contacts are laminated and compressed, and heat-fused with hot air, an inert gas, or superheated steam at a temperature at least 10 ° C. higher than the melting point of the thermoplastic elastomer serving as a heat-bonding component. The fiber contacts are heat bonded and cooled. To obtain a more preferred fibrous structure of the present invention, then, for the reasons set forth above, at least 20% above the melting point of the thermoplastic polyester ether copolymer.
Pseudo-crystallization treatment at a temperature lower than 0 ° C. is preferable because the recoverability is improved. It is more preferable to apply compressive strain of about 10% and heat-treat to improve the recoverability.

The more preferable fiber structure of the present invention thus obtained has a heat resistance and sag resistance close to those of polyurethane foam, which has hitherto been considered impossible with a fiber cushion,
It has excellent cushioning properties and does not get stuffy when worn,
Also, it can be used as a cushioning material that can be recycled.

[0019]

【Example】

Examples 1 and 2 and Comparative Examples 1 to 5 Preparation of Thermal Adhesion Component Dimethyl terephthalate (DMT) or and dimethyl isophthalate (DMI) or naphthalene 2.6 dicarboxylic acid (DMN) as an acid component. As a glycol component, 1-4 butanediol (BG) and polytetramethylene glycol (PTMG) were charged together with a small amount of a catalyst and a stabilizer, and after transesterification by a known method, the temperature was increased and the pressure was reduced. Condensation produced a polyester ether block copolymer elastomer. The produced polyester ether block copolymerization elastomer is pelletized and then heated and vacuum dried, and 0 to 3% by weight of Ionox 330 manufactured by Ciba-Geigy Co. as an antioxidant is mixed and melt-kneaded again.
The pelletized product was sufficiently removed of water with a dry heated inert gas and used as a heat-adhesive component. Table 1 shows the formulation and melting point of the obtained polyester ether block copolymer. For comparison, dimethyl terephthalate was used as the acid component.
(DMT) or and dimethyl isophthalate (DM
I) and ethylene glycol (E) as a glycol component
G) is charged with a small amount of a catalyst and a stabilizer, and transesterified by a known method, followed by polycondensation while heating and decompressing to produce a low melting point inelastic polyester, pelletized, heated and vacuum dried, and then biaxial. Add and knead the antioxidant with an extruder,
It was pelletized again, dried and subjected to a heat-adhesive component. Table 1 shows the formulation and melting point of the obtained low melting point non-elastic polyester.

[0021]

[Table 1]

Preparation of Thermally Adhesive Fibers The resulting polyester ether block copolymer was prepared by using a thermal adhesive component as a sheath component, a component supporting a stretchable three-dimensional network structure, or a comparative polybutylene terephthalate. (PBT) and polyethylene terephthalate (PET) were used as core components, and the unstretched yarn was obtained by spinning at a spinning temperature of 260 ° C. to 285 ° C. by a conventional method with a weight ratio of the sheath / core of 50/50. Then, it is stretched 3.4 times in a warm bath at 50 ° C., then heat-treated at a fixed length at 90 ° C. for dry heat, and after applying a finishing oil agent, mechanical crimping is applied by a crimper so that the mechanical crimp does not extend. It was supplied to the cutter with tension and cut into 51 mm to prepare a 4-denier heat-bonded composite short fiber. The properties of the fibers obtained are shown in Table 2. Assuming that the relative viscosity of the polyester ether block copolymer of the sheath component in the fiber and the low-melting point inelastic polyester has an additive property to the solution viscosity, the core components of both components are the same under the same spinning conditions. It was determined as the relative viscosity of the fiber obtained by supplying the components and the relative viscosity corrected by the composition ratio in the fiber.

[0023]

[Table 2]

Preparation of Fiber Structure 30% of the resulting heat-bonded composite short fibers having mechanical crimps,
It is a hollow of 13 denier made by a conventional method and has 3 protrusions on the outside.
70% PET short fiber with three-dimensional crimp in the cross section
And the web obtained by mixing and opening the fibers with a card having a density of 0.
Compressed so as to be 03G / cm ³ was heat-treated for 5 minutes with hot air at 0.99 ° C. to 210 ° C., and molded into the cushion material of the plate, once compressed so that after cooling, the density is 0.04 g / cm ^3,
A cushioning material was obtained by re-heat treatment for 30 minutes with hot air at 100 ° C. and cooling. For comparison, were prepared in the same manner without reheating what the density of ones and 0.12 g / cm ³ of 0.004 g / cm ^3. Table 3 shows the preparation conditions and the finished state of the cushion material, and Table 4 shows other characteristics of the obtained cushion material. The compression residual strain of 70 ° C., the repeated compression residual strain at room temperature, and the impact resilience are according to the method of JISK-6401. The compression hardness of 25% is 25% of the thickness of the cushion material with a disk of φ150 mm in Tensilon manufactured by Baldwin.
It is measured as the compression force during compression. As for the sitting comfort, 10 panelists were allowed to sit in the room at 30 ° C. for 1 hour each, and the feeling of sitting on the floor, sitting comfort, and stuffiness were evaluated. If the buttocks and thighs were sore that the person could not sit for 1 hour, the sitting comfort was poor.

[0025]

[Table 3]

[0026]

[Table 4]

Since the cushioning materials of Examples 1 and 2 of the present invention have the elastic network structure made of the elastic composite fiber, they are excellent in cushioning property, excellent resistance to heat and heat at high temperature, and excellent at room temperature. Shows sag resistance. Furthermore, it is a cushioning material that hardly feels like being on the floor, is resistant to stuffiness, and allows you to sit for a long time. In particular, the most preferred embodiment of the present invention is a cushioning material which exhibits heat resistance and fatigue resistance similar to urethane foam, and which is comfortable to sit on. Comparative Example 1 shows the case where a known elastomer in which an amorphous component is copolymerized in order to lower the melting point is used for the sheath and an elastic composite fiber whose core is made of non-elastic polyester is used. The bonding points are sufficiently formed in the shape of an ammo, and the spindle-shaped nodes are also formed.However, the elastomer is easily plastically deformed, and the elastomer component surrounding the core is eliminated, so that the network -Since the non-elastic polymer is connected, the heat resistance and sag resistance are poor and the cushioning material is inferior. Comparative Example 2 in which the thermo-adhesive component is a non-elastic polymer having the same morphology
Shown in. The adhesive component is brittle and plastic deformation easily occurs, so the heat resistance is particularly poor, and the settling resistance at room temperature is poor, and since it has a hard texture due to lack of elasticity, it does not feel like sticking to the floor but the buttocks and thighs. It is a cushioning material that makes it difficult to sit for a long time because it is pressed and becomes painful. Comparative Example 3 shows a case where the difference in melting point between the elastic composite fiber and the adhesive component is small. Since the core component of the elastic composite fiber does not participate in the formation of the network structure, the number of bonding points is reduced, and the heat resistance durability and cushioning property are slightly deteriorated. Comparative Example 4 shows the case where the density is small outside the range of the present invention. When a constant strain is applied, the fibers are bulky and the stress received by each fiber is significantly reduced, so the fatigue at 50% strain is not bad, but it is too fluffy and cannot be used as a cushioning material. Comparative Example 5 is a high density which is outside the scope of the present invention. Since it becomes almost a polymer block and a large compressive force for crushing the block is required for 50% compression, repeated compressive residual strain and 25% compression hardness exceed the capability of the measuring instrument and are difficult to measure. Of course, sitting comfort was the same as sitting on a polymer, which was the worst. In addition, the cushion materials of Examples 1 and 2 were tested by the 45 ° mesenamine method and 4
As a result of evaluating the flame retardancy by the 5 ° alcohol lamp method,
All the cushion materials of Examples 1 and 2 passed. The result of evaluating the polyurethane foam for comparison was a failure. Moreover, the results of measuring the toxicity index of the combustion gas by the method of JISK-7217 are 5.1 for all the cushion materials of Examples 1 and 2, and the foam polyurethane is as high as 7.5, which is a preferred embodiment of the present invention. It is shown that the fiber structure of is highly safe.

[0028]

Industrial Applicability The fiber structure of the present invention has a structure in which the non-elastic crimped short fibers are heat-bonded with the thermoplastic elastomer component by the elastic composite fiber composed of the thermoplastic elastomer in the matrix of the non-elastic crimped short fibers. As it is a fibrous structure that forms a three-dimensional network structure with excellent elasticity, it has excellent cushioning properties, excellent heat resistance and durability, and excellent sag resistance. A fiber structure suitable for a cushioning material that is comfortable to sit on. In particular, the fiber structure of the most preferred embodiment of the present invention exhibits excellent heat resistance and durability similar to foamed polyurethane, and excellent settling resistance, and is the most suitable fiber structure for a cushioning material with higher safety than foamed polyurethane. The body and its manufacturing method. Further, since the elastic composite fiber is a fiber structure made of a thermoplastic polymer, it can be recycled as a fiber structure again by opening and remolding, and it is very useful for preservation of the global environment. Useful applications of the fiber structure of the present invention,
It is especially suitable for automobiles, railway vehicles, and ships that have severe operating conditions. Of course, it is also suitable for furniture and bed applications.

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-4-357990 (JP, A) JP-A-5-163657 (JP, A) JP-A-5-163658 (JP, A) JP-A-5- 247819 (JP, A) International publication 91/019032 (WO, A1) (58) Fields surveyed (Int.Cl. ⁷ , DB name) D04H 1/00-18/00 B68G 1/00-15/00 D01F 1 / 00-13/04

Claims (2)

(57) [Claims] 1. A fibrous structure obtained by three-dimensionally mixing non-elastic crimped short fibers (A) and elastic composite fibers (B),
The elastic conjugate fiber (B) has a thermoplastic elastomer (C) having a melting point of 40 ° C. or more lower than that of the polymer forming the non-elastic crimped short fiber (A), and a melting point of 30 ° C. or more higher than the thermoplastic elastomer. The thermoplastic elastomer (D) has, and the thermoplastic elastomer (C) is exposed on the surface of the composite fiber at least ½ or more,
At the contact points where the fibers (A) and the fibers (B) or the fibers (B) and the fibers (B) are three-dimensionally formed, the portions bonded by heat fusion are scattered, and the density is 0.005 to 0. 10
A fibrous structure characterized in that it is g / cm ³ . 2. The melting point of the non-elastic crimped short fibers and the polymer constituting the non-elastic crimped short fibers in the heat-bonding component is at least 4 from the melting point.
Thermoplastic elastomer (C) having a melting point lower than 0 ° C
And a thermoplastic elastomer (D) having a melting point at least 30 ° C. higher than that of the heat-adhesive component, and the former (C) is mixed with the elastic composite fiber exposed at least ½ or more on the fiber surface to open and elastic After forming a three-dimensional fiber contact between the composite fibers and between the composite fiber and the non-elastic crimped short fiber,
A method for producing a fiber structure, which comprises heat-treating at a temperature at least 10 ° C. higher than a melting point of a thermoplastic elastomer (C) as a heat-bonding component to thermally bond at least a part of the fiber contacts.