JP3204344B2 - Elastomer-based heat-bonded conjugate fiber and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester-based heat-bonded conjugate fiber, and particularly to a polyester material having excellent cushioning properties when used as a cushion material such as a nonwoven fabric or cotton padding at room temperature and under heating. The present invention relates to a polyester-based heat-bonded conjugate fiber that can provide durability.

[0002]

2. Description of the Related Art At present, in the field of cushioning materials for furniture and vehicles, foamed urethane, polyester fiber-filled cotton,
Also, resin cotton and polyester hard cotton to which polyester fibers are bonded are known.

[0003] However, foamed urethane has good durability as a cushion, but has a large feeling of flooring, is inferior in moisture permeability and has heat storage properties, and is easily stuffy. Is incinerated because of the need to add halides, causing poisoning due to the generation of toxic gas during a fire, and is difficult to recycle.However, the incinerator is seriously damaged, and the cost of removing toxic gas is high. There is. Further, although the processability is excellent, there is a problem of pollution of chemicals used during the production. Further, in the case of polyester fiber-filled cotton, since the fibers are not fixed, the shape at the time of use is collapsed, the fibers move, and the crimp is set, so that the bulkiness and the elasticity are reduced. .

Japanese Patent Application Laid-Open Publication No. Sho 6 (1994) discloses a resin cotton in which polyester fibers are bonded with an adhesive, for example, a rubber using an adhesive as a rubber.
Nos. 0-11352, JP-A-61-141388 and JP-A-61-141391. Japanese Patent Application Laid-Open No. 61-137732 discloses an example using urethane. These cushioning materials are inferior in durability,
In addition, there are also problems such as being unable to be recycled, troublesome workability and pollution of chemicals used during production.

[0005] Polyester hard cotton, for example, JP-A-58-3
JP-A No. 1150, JP-A-2-154050, JP-A-3-220354, etc., are disclosed in Japanese Patent Application Laid-Open No. Sho 58-58, because the adhesive component of the heat-bonding fiber used is a brittle amorphous polymer. -136828, JP-A-3-
There is a problem that the adhesive portion is brittle and the durability is poor such that the adhesive portion is easily broken during use and the form and elasticity are reduced. As an improved method, a method of performing confounding treatment has been proposed in Japanese Patent Application Laid-Open No. 4-245965, but there is a problem that the brittleness of the bonded portion is not solved and the elasticity is greatly reduced. In addition, there is also complexity in processing. Further, there is a problem that the bonded portion is hardly deformed and it is difficult to provide soft cushioning. For this reason, Japanese Patent Application Laid-Open No. Hei 4-240219 proposes a method for improving a heat-bonding fiber using a polyester elastomer which has a soft bonded portion and recovers even when deformed. The polyester elastomer used for this fiber contains 50 to 80 mol% of terephthalic acid in the acid component of the hard segment and the content of polyalkylene glycol as the soft segment is limited to 30 to 50% by weight. Melting point 180 as other acid component composition
C. or less, since it is considered the same as the fiber described in Japanese Patent Publication No. 60-1404, it contains isophthalic acid and the like and becomes amorphous, and has a low melt viscosity to improve the formation of the heat-bonded portion. However, there is a problem that plastic deformation is apt to occur, and heat resistance and compression resistance are reduced.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and provides a polyester-based cushioning material having excellent cushioning properties, excellent heat resistance and durability, less stuffiness when worn, and recyclable. It is an object of the present invention to provide a polyester-based heat-bonding conjugate fiber suitable for producing a polyester.

[0007]

Means for Solving the Problems Means for solving the above-mentioned problems, that is, the present invention is a composite fiber of a thermo-adhesive component and a non-heat-adhesive component comprising a thermoplastic elastomer, wherein the thermo-adhesive component contains a soft segment. A thermoplastic elastomer having an amount of 30% by weight or more, wherein the non-thermo-adhesive component is a thermoplastic elastomer having a melting point higher than the melting point of the thermo-adhesive component by 30 ° C. or more, and no three-dimensional crimp based on latent crimp ability has not been developed. A polyester elastomer containing 30% by weight or more of an elastomeric heat bonding conjugate fiber and a soft segment as a heat bonding component, and a polyester elastomer having a melting point higher by at least 30 ° C. than the melting point of the heat bonding component. As a component, composite spinning is performed at a temperature at least 20 ° C. higher than the melting point of the non-adhesive component to increase the potential crimpability. Kumishi, after drawing, or then impart mechanical crimps, a method elastomeric thermal bonding conjugate fiber characterized by cutting at a tension as not stretched mechanical crimping.

The heat-bonding component of the present invention has both a heat-bonding component and a non-heat-bonding component for the purpose of forming a three-dimensional network structure in which matrix fibers are connected by a spiral coil with fibers having elongation recovery properties. It must be a thermoplastic elastomer. Examples of the thermoplastic elastomer include polyether-based glycols, polyester-based glycols, and polyesters having a molecular weight of 300 to 5,000 as soft segments.
Examples thereof include polyester-based elastomers, polyamide-based elastomers, and polyurethane-based elastomers obtained by block-copolymerizing a bone-based glycol or the like. However, polyester fibers are often used in the matrix of the cushioning material from the most preferable use form of the present invention. Therefore, it is preferable that the thermoplastic elastomer be a polyester-based elastomer having good adhesiveness. Examples of the polyester elastomer include 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 having an aliphatic polyester as a soft segment. A polymer can be exemplified. More specific examples of polyester ether block copolymers include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, naphthalene 2.6 dicarboxylic acid, naphthalene 2.7 dicarboxylic acid, and diphenyl 4.4 4 'dicarboxylic acid. 1,
An alicyclic dicarboxylic acid such as 4-cyclohexanedicarboxylic acid, an aliphatic dicarboxylic acid such as succinic acid, adipic acid, 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, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, and 1.1 cyclohexane dimethanol Ru, 1 ・
(4) at least one diol component selected from alicyclic diols such as cyclohexanedimethanol, or ester-forming derivatives thereof, and an average molecular weight of about 3;
A ternary block copolymer comprising at least one of polyalkylenediols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide-propylene oxide copolymer, etc. It is. The polyester ester block copolymer is a ternary block copolymer composed of at least one of the above dicarboxylic acids and at least one of diols and polyester diols such as polylactone having an average molecular weight of about 300 to 3,000. . In consideration of thermal adhesion, hydrolysis resistance, elasticity, heat resistance, etc., the dicarboxylic acid may be terephthalic acid or naphthalene 2.
6 dicarboxylic acid, a tertiary block copolymer of 1.4 butanediol as a diol component, polytetramethylene glycol as a polyalkylenediol or a tertiary block copolymer of a polylactone as a polyesterdiol. Polymers are particularly preferred.

The heat bonding component constituting the conjugate fiber of the present invention is a polyester elastomer containing a soft segment of 30% by weight or more as the heat bonding component. The elastomer of the preferred heat-adhesive component of the present invention is, for example, a block copolymer of 1-4 butanediol and a polyalkylenediol as a glycol component, and a copolymerization amount of the polyalkylenediol is 30% by weight. % Or more and 80% by weight or less. In order to obtain an elastomer, it is necessary that a polyalkylenediol is block-copolymerized. As a result, when the structure undergoes deformation, even if the heat-bonded portion which receives a relatively large stress in a concentrated manner is deformed, the elasticity is developed and the recovery can be achieved when the deformation force is released. The recoverability derived from the rubber elasticity is proportional to the copolymerization amount of the polyalkylenediol. At the same time, the melting point and heat resistance decrease. If the copolymerization amount of the polyalkylenediol is 30% by weight or less, the recoverability due to rubber elasticity is inferior. On the other hand, if the content is 80% by weight or more, the melting point is lowered and the heat resistance is deteriorated. The preferred copolymerization amount of the polyalkylenediol of the present invention is 4
It is from 0% by weight to 70% by weight, more preferably from 50% by weight to 60% by weight. As the polyalkylenediol used in the present invention, known polyalkylenediols can be used, but polytetramethylene glycol is particularly preferred. The preferred average molecular weight is from 500 to 5,000, particularly preferably from 1,000 to 3,000. It is preferable that terephthalic acid, naphthalene 2,6-dicarboxylic acid and the like be contained in an amount of 90 mol% or more as an acid component. More preferably, the content of terephthalic acid or naphthalene 2.6 dicarboxylic acid is 95 mol% or more, particularly preferably 100 mol%. If the content of terephthalic acid or naphthalene 2,6-dicarboxylic acid is large, the crystallinity of the hard segment is improved, plastic deformation is difficult, and heat resistance and sag resistance are improved. If the content of terephthalic acid is less than 90 mol%, the crystallinity of the hard segment is inferior, so that it is likely to be plastically deformed and the heat resistance and sag resistance are inferior. It is not preferable because the heat resistance and sag resistance when further crystallization treatment is performed after the melt thermoforming is inferior. Although the reason is not clear, when the terephthalic acid content is large, an endothermic peak more clearly appears at a temperature lower than the melting point in a melting curve by a differential scanning calorimeter (DSC). By analogy with this, it is considered that pseudo-crystallization-like cross-linking points are formed, and that heat resistance and sag resistance are improved.

[0010] The non-heat-adhesive component constituting the heat-adhesive fiber of the present invention, when the heat-adhesive component is caused to flow to form a heat-adhesive point,
For the purpose of forming a three-dimensional network structure having a stretch recovery property connecting the matrix fibers without flowing, the melting point of the non-heat-bonding component is at least three times higher than the melting point of the heat-bonding component.
0 ° C or higher. When the temperature is higher than the melting point of the heat bonding component by less than 30 ° C., the temperature of the heat bonding is 10 to 30 ° C. higher than the melting point of the heat bonding component. The heat bonding component also flows,
It is not preferable because a three-dimensional network structure having a stretch recovery property connecting the matrix fibers cannot be formed. The melting point of the non-heat-bonding fiber of the present invention is 3 times lower than the melting point of the heat-bonding component.
Preferably, the temperature is increased by 5 ° C. or more, more preferably, by 40 ° C. or more. It should be noted that a three-dimensional network having a stretch-recovery property connecting the matrix fibers formed by the non-heat-bonding component.
The elastic structure has a larger elastic recovery limit strain than the inelastic polymer fiber, has a good recovery property due to the development of rubber elasticity even when subjected to large deformation due to a large force, and has a good heat resistance at the pseudo cross-linking point due to the crystal structure formation. The soft segment content should be at least 5% by weight. When the soft segment content is less than 5% by weight, rubber elasticity peculiar to the elastomer is hardly developed, and when formed into a cushion material, the elastic function of a three-dimensional network structure connecting matrix fibers is inferior, and the fiber as a cushion material is used. It is not preferable because the cushioning property and the anti-sagging property of the structure are inferior. On the other hand, if the content of the soft segment exceeds 50% by weight, the melting point is greatly reduced, and it is necessary to lower the melting point of the heat bonding component. Thus, a problem of fusion occurs during melt spinning, and the recoverability at low temperatures is improved. However, the content of the hard segment is reduced, and the heat resistance of the pseudo-crosslinking point due to the formation of the crystal structure is reduced, so that the heat resistance and sag resistance of the cushion material is undesirably reduced. The soft segment content of the non-heat-bonding component of the present invention is preferably 5 to 50% by weight, more preferably 1 to 50% by weight.
0 to 45% by weight. In order to improve the heat resistance of the hard segment, the average molecular weight of the soft segment is preferably such that the number of repeating units is large, preferably 500 to 40.
00, more preferably 1000 to 3000. In addition, if the acid component of the hard segment contains a component that lowers crystallinity, for example, isophthalic acid or the like, it is easily plastically deformed and the melting point is lowered. It is preferable that the content be as small as possible because it causes a decrease in durability, and it is more preferable not to contain it.

The conjugate fiber of the present invention needs to have latent crimping ability. However, it is necessary that the latent crimping ability is not expressed.
Because of the potential crimping ability, just before thermal bonding molding,
When heated, coiled crimps are developed and the heat-bonded conjugate fibers are wound around each other and the base material, and then further heated to a high temperature to melt the heat-bonded component, and the contact portions are adhered to each other, and connected by the stretchable conjugate fiber. A coil-shaped three-dimensional network structure is formed. For this reason, the required latent crimping ability of the preferred conjugate fiber of the present invention is 2 or more as the latent crimping ability (1 / ρ) developed when subjected to free treatment at 110 ° C. under dry heat. If it is less than 2, the winding around the base material will be insufficient, and the coil diameter of the coil itself will increase, and the spring effect will decrease. More preferably, the latent crimpability of the present invention is 1 / ρ of 3 or more. Since the cushioning material obtained by using such a conjugate fiber of the present invention has both the elasticity of the fiber itself and the elasticity of the coil spring, the cushioning material is rich in elasticity, and it has been considered that a fiber cushion is impossible in the past. It becomes possible to have heat resistance and sag similar to foamed polyurethane. The composite ratio of the heat bonding component and the non-thermal bonding component is preferably 10/90 to 70/3.
0. If the amount of the heat-adhesive component is small, the rubber elasticity function at the bonding point decreases, and the elasticity decreases, which is not preferable. On the other hand, if the amount of the non-heat-bonding component is small, the coil spring function between the three-dimensional network structures is reduced, and the recovery and elasticity are reduced. A more preferred composition ratio is 30/70 to 60/40. The method of imparting the latent crimping ability can be obtained by spinning into a conventionally known method, for example, a structure of a side-by-side type, an eccentric sheath-core type or the like. Then, it is stretched. Preferred stretching conditions are as follows: the stretching temperature is 70 ° C. or lower in a warm bath, and the breaking stretching ratio is about 0.8.
It is obtained by stretching at a magnification of ~ 0.9 times, applying mechanical crimp at low temperature, and feeding and cutting the cutter with low tension so that the mechanical crimp does not elongate. Stretching at a high temperature is not preferred because the potential crimpability decreases. Also, if a three-dimensional crimp is developed before thermoforming, it is not preferable because winding adhesion becomes difficult during thermoforming. Also, the elastomer is sticky,
Since the friction of the yarn is high, the fiber opening tends to be poor at the time of card opening, and it is necessary to maintain a mechanical crimp that is easy to open. The mechanical crimp has a crimp number of 5 to 30 ridges / inch and a crimp rate of 5 to 30.
% Can be used, but preferably the number of crimps is 1
0 to 25 ridges / inch, crimp rate is 10 to 25%. It is particularly preferable to use an oil agent having a low friction coefficient as the finishing oil agent.

Preferred polyester resins in the present invention
As for the molecular weight of tellurium, the relative viscosity (η _{sp / c} ) measured in a phenol / tetrachloroethane mixed solvent at 40 ° C. is 1.8 or more for the thermal adhesive component. If it is less than 1.8, the fluidity is improved, but the recovery of the bonding point is reduced, and the heat resistance and durability of the fiber structure are reduced. If it is 2.5 or more, the fluidity is reduced, and the formation of thermal bonding points tends to be insufficient. The more preferable relative viscosity of the heat bonding component is 2.0 or more and 2.5 or less. On the other hand, since the non-adhesive component forming the stretchable three-dimensional network structure is provided with heat resistance, the content of the hard segment is larger than that of the heat-adhesive component, and the relative viscosity is slightly lower. The preferred relative viscosity is 1.0 or more, more preferably 1.5 or more, as described in JP-A-4-240219, which can impart recoverability and toughness. When the thermal stability is as high as 250 ° C. or more, the molecular weight is significantly reduced due to thermal decomposition due to the large copolymerization amount of For this reason, in the present invention, the antioxidant is positively added preferably in an amount of 1% by weight or more, more preferably 2% by weight or more.
% By weight and 5% by weight or less. With such a composition, spinning at a high temperature is also possible, and the non-adhesive component is an elastomer having a high melting point, for example, a hard segment component of polybutylene terephthalate or polyethylene terephthalate.
And polybutylene naphthalate, or an elastomer having a repeating unit of the copolymer component increased and having a melting point of 220 ° C. or more can be used. Furthermore,
The thermal bonding can be performed by melting and bonding at a high temperature of 200 ° C. or more in air, and a decrease in molecular weight at this time can be suppressed. Thus, since the molecular weight of the elastomer can be kept high, the molded article also has a remarkably improved recoverability due to rubber elasticity. Preferred antioxidants used in the present invention include conventionally known hindered phenol compounds and hindered amine compounds. However, no toxic gas is emitted during combustion.
Dofenol compounds are preferred. The polyester elastomer used for the fiber of the present invention is described in, for example,
Although it can be obtained by a conventionally known method such as 120626, if an antioxidant is added in a large amount at the time of polymerization, it will sublimate and cause troubles such as clogging of a polymerization can, and the effect of addition is drastically reduced. Or kneading with a twin-screw extruder after pelletizing.

The conjugate fiber of the present invention may be used alone as a fiber aggregate such as a nonwoven fabric or a cushion material, or as a mixed aggregate with another fiber (base material) containing 5% by weight or more of the conjugate fiber. good. Preferred mixed base materials include PET, PEN,
High melting point high crystalline polyester such as PCHDT and PB
There is a fiber made of T, good adhesiveness, excellent cushioning property, excellent heat resistance and durability, easy to get stuffy when worn, and easy to produce a fiber assembly that becomes a recyclable polyester cushioning material. Is possible. The fiber aggregate containing the conjugate fiber of the present invention is compressed to an arbitrary density before thermoforming, heat-treated to form a entanglement point due to the appearance of crimp, and the entanglement point and the contact point are fused and integrated. In this case, a fiber molded body having an arbitrary density and hardness can be obtained by thermoforming at a temperature higher by 10 to 120 ° C. than the melting point of the heat bonding component, preferably by 20 to 100 ° C. for the above-mentioned reason. Then, once cooled and solidified, heat-treated at a temperature at least 10 ° C. lower than the melting point of the heat-bonding component, and preferably heat-treated with a strain of 10% or more. Sex is greatly improved. Note that this effect is significantly reduced as the acid component of the adhesive component contains more amorphous components.

[0014]

The present invention will be described in detail below with reference to examples.

Examples and Comparative Examples Preparation of Polyester Elastomer Dimethyl terephthalate (DMT) or dimethyl isophthalate (DMI), dimethylene naphthalate (DMN) as an acid component and a glycol component as an acid component 1-4 Butanediol and polytetramethylene glycol (PTMG) as a soft segment were charged together with a small amount of a catalyst and a stabilizer, followed by transesterification by a known method, followed by polycondensation at elevated temperature and reduced pressure to give polyester ether. A terblock copolymer elastomer was produced. Polyester A formed
The terblock copolymer elastomer is pelletized, heated and vacuum-dried, mixed with 3% by weight of Ionox 330 manufactured by Ciba Geigy as an antioxidant, melt-kneaded again, and dried into a heated inert gas. To remove the water sufficiently, and used as a heat bonding component. Table 1 shows the formulation and melting point of the obtained polyester ether elastomer.
For comparison, dimethyl terephthalate (D
MT) and dimethyl isophthalate (DMI)
A non-elastomeric low-melting polyester was prepared by copolymerizing ethylene glycol (EG) as a polyester component. The characteristics are also shown in Table 1.

[0016]

[Table 1]

Preparation of heat-bonded fiber The obtained elastomer is used as a sheath component and a core component, or
PET or PBT as a core component, and a sheath / core weight ratio of 50
The spinning temperature is adjusted to 260
An undrawn yarn was obtained by spinning at a temperature of from 280C to 285C. The degree of eccentricity was set to 0.15 as a value (L / R) obtained by reducing the distance L from the center of the fiber to the center of the core by the radius R of the fiber. Next, the film was stretched 3.4 times in a warm bath at 50 ° C., applied with a finishing oil, and then mechanically crimped with a crimper.
The machine crimp was supplied to the cutter with a tension that does not extend, and cut into 51 mm to prepare a 4-denier heat-bonded conjugate short fiber. Table 2 shows the properties of the obtained fibers. The latent crimpability (1 / ρ) is shown by the reciprocal of the radius of curvature of the developed helix when subjected to a free treatment at 110 ° C. For comparison, a composite fiber in which the elastomer was used as a sheath component and a core component without eccentricity was also prepared. The characteristics are also shown in Table-2.

[0018]

[Table 2]

The obtained heat-bonded conjugate short fiber having a mechanical crimp is 30%, and a 13-denier hollow PET film having a three-dimensional crimp in a cross section having three projections formed by a conventional method. A web obtained by blending and opening 70% of the fibers with a card is compressed to a density of 0.04 g / cm ³ and heated at 150 ° C.
Heat treatment with hot air at ~ 210 ° C for 5 minutes to form a flat cushion material, or compress it to a density of 0.03 g / cm ³ and heat treat it with hot air at 200 to 210 ° C for 5 minutes. Is reduced to 0.04 g / cm ^3, and 10
Heat treatment was performed with hot air of 0 ° C. for 30 minutes, followed by cooling to form a cushion material. Table 3 shows the characteristics of the obtained cushion material. The residual compression at 70 ° C., the residual compression at room temperature, and the rebound resilience are measured according to JIS K-6401.

[0020]

[Table 3]

The cushion material (Examples 1 to 3) prepared using the heat-bonding conjugate fiber of the present invention has excellent cushioning properties.
It shows excellent heat resistance at high temperature and excellent resistance at room temperature. In Comparative Example 1, an elastomer was used as the heat bonding component.
Is an example in which the non-elastomer is used as the non-heat bonding component, so that the heat and sag resistance is inferior. Comparative Example 2 is an example in which the non-thermal bonding component is also melted during thermoforming due to a small difference in melting point, and a three-dimensional network of elastomer fibers cannot be formed, so that heat resistance and sag resistance are poor. Comparative Example 3 is an example in which the heat-sag resistance is inferior because the amount of the soft segment of the thermal adhesive component is small. Comparative Example 4 is an example of a conjugate fiber using a non-elastomer, which is extremely inferior in heat resistance and sag resistance at room temperature to that of an elastomeric material. Comparative Example 5 is an example in which it has no latent crimpability and thus has poor heat and sag resistance. Thus, those deviating from the requirements of the present invention are inferior in heat resistance and sag resistance and sag resistance at room temperature.

[0022]

The heat-bonding conjugate fiber of the present invention has a strong and stretchable bonding point by spirally crimping and bonding the base material when other fibers are used as the base material for the cushioning material or the like. The helix formed and formed at the same time acts as a spring, exhibiting unprecedented excellent cushioning properties, excellent high-temperature resistance to heat, and excellent resistance to room temperature. In particular, the polyester fiber has good adhesiveness, the above performance can be further improved, and moisture permeability and water permeability can be maintained, so that a comfortable seat with little stuffiness can be provided. Further, it can be recovered and reprocessed without separation, and is particularly suitable for seats of automobiles, trains, ships, and the like. Furthermore, it will be suitable for beds and furniture. In addition to cushioning material applications, it is possible to use non-woven fabric materials that can be stretched regardless of low and high weights by utilizing the properties of excellent crimping and the formation of good stretch points. Pads and bra cups, synthetic leather base cloth and base cloth for upholstery cloth, padding for safety material, elastic heat insulating material, elastic wadding layer for seats, elastic non-woven fabric with good breathability, adhesive non-woven fabric for interior materials, etc. Widely applicable. Furthermore, spinning is possible, and the present invention can be applied to clothing applications such as spun yarn and decorative yarn.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-50-118020 (JP, A) JP-A-3-185116 (JP, A) JP-B-56-4722 (JP, B2) (58) Survey Field (Int.Cl. ⁷ , DB name) D01F 8/00-8/18

Claims (2)

(57) [Claims] 1. A a composite fiber with the thermoplastic elastomer by comprising heat-bonding component and a non-heat-bonding component, heat-bonding component is a thermoplastic elastomer of less than 30 wt% soft segment content, non-heat-bonding component is the An elastomeric heat-bonded conjugate fiber comprising a thermoplastic elastomer having a melting point higher than the melting point of the heat-bonding component by 30 ° C. or more, and in which three-dimensional crimping based on latent crimping ability has not been developed. 2. A polyester composition containing at least 30% by weight of a soft segment as a heat bonding component, and a polyester elastomer having a melting point at least 30 ° C. higher than the melting point of the thermal bonding component as a non-thermal bonding component. The composite spinning is performed at a temperature higher than at least 20 ° C. to provide a latent crimping ability, and after stretching, or subsequently, a mechanical crimp is applied, and cut with a tension that does not elongate the mechanical crimp. To produce elastomeric heat-bonded composite fibers.