JP3134945B2 - Thermal adhesive composite fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to heat resistance, bulkiness,
The present invention relates to a heat-adhesive conjugate fiber particularly useful for cushioning materials having excellent elasticity, comfort and safety.

[0002]

2. Description of the Related Art As a heat-adhesive conjugate fiber, a polyester-based non-elastomeric low-melting-point polymer having a sheath portion is known. However, when this is applied to a cushion material, the heat resistance and durability are extremely poor. In particular, those containing isophthalic acid as the acid component of the polyester have a large tendency. Thus, as an improvement, those in which the core component is hollowed out (JP-A-62-299514, JP-A-63-264915, etc.) have been proposed. It is enough. Also,
Since the adhesive component is hard, moderate elasticity is required to be controlled by the crimping of the base material, so that even at room temperature use, it promotes crimp setting, and furthermore, to promote the destruction of the bonding point, There are problems such as difficulty in maintaining elasticity. From the viewpoint of lightness, olefin-based heat-adhesive conjugate fibers are known, and even hollow fibers have been proposed. However, the olefin-based resin has a low glass transition temperature and is easily deformed plastically, and thus has extremely poor heat resistance and durability. In addition, it lacks in moisture permeability and water permeability, so it lacks comfort. From the viewpoint of safety, the toxic property (toxicity index) of the combustion gas is preferably such that the polyester type has a toxicity as low as the olefin type. In addition, olefins are prone to self-oxidation,
Exposure to heat storage conditions for extended periods of time risks decomposing and igniting, and is no better than polyester. Polyester elastomer fibers are known in, for example, JP-A-63-6110. However, there is no material suitable for a cushion material, and only a non-woven fabric having no thickness is known.

[0003]

SUMMARY OF THE INVENTION The present invention solves the above problems and provides a heat-adhesive composite suitable for use as a cushioning material having excellent heat resistance, bulkiness, elasticity, safety, and comfort. Is to provide fibers.

[0004]

The present invention employs the following means to solve the above-mentioned problems. That is, in the present invention, the sheath component is a polyester elastomer having a melting point of 150 ° C. or more and 200 ° C. or less, and the core component is a melting point of 220 ° C.
Made of the above polyester, and the core is side-by-side
After the side composite type or the eccentric hollow type is stretched in two steps
10g initial tensile resistance at 70 ° C
/ Denier or more, and a crimped form is a corrugated three-dimensional crimp.

Hereinafter, the present invention will be described in detail. As the polyester elastomer of the present invention, a polyether copolymer elastomer is preferable. More specifically, there are elastomers derived from aromatic dicarboxylic acids, aliphatic diols, and poly (alkylene oxide) glycols, including terephthalic acid, 1,4 butanediol, and poly (alkylene having a number average molecular weight of about 300-6000. Elastomers composed of (oxide) glycols are preferred. If necessary, dicarboxylic acids other than terephthalic acid and 1,4
One or both of low molecular weight diols other than butanediol can be added. Examples of the dicarboxylic acid other than terephthalic acid include isophthalic acid, phthalic acid, adipic acid, and sebacic acid. Examples of the diol component other than 1,4 diol include ethylene glycol, trimethylene glycol, and pentamethylene glycol. it can. Furthermore, examples of the poly (alkylene oxide) glycol include poly (tetramethylene oxide) glycol, poly (1,2 propylene oxide) glycol, poly (1,3 propylene oxide) glycol, and the like. Methylene oxide) glycol is preferred. Particularly preferred polyester polyether copolymer elastomers for use in the present invention include JP-B-53-19638 and JP-B-55-27.
No. 697, for example, a copolymerized polyester containing polybutylene terephthalate and polytetramethylene oxide glycol as main components. Other additives include third components such as various copolymer components, crosslinking agents, adhesives, light stabilizers, matting agents, etc., as long as they do not generate toxic gas during combustion, do not promote hydrolysis, and do not impair elasticity. Can be added.

Examples of the polyester forming the core component of the present invention include polyethylene terephthalate, polybutylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene naphthalate, and copolymerized polyesters thereof. Further, as the third component, various copolymer components such as not generating toxic gas at the time of combustion, not promoting hydrolysis, and hardly causing plastic deformation at 60 ° C. or less, a colorant, a light stabilizer, a matting agent, and the like can be added.

Since the fiber of the present invention is a heat-bonded fiber, it needs a sheath-core structure, and the portion where the sheath portion comes into contact with the base material is bonded and joined with the melted sheath component. The sheath component serving as the adhesive component is a polyester elastomer.
With non-elastomer, if the compressive load of the cushioning material exceeds the stress supported by the crimping of the base material, deformation of the bonding point occurs, and the bonding point is plastically deformed and the structure can not return to the original , Causing significant settling. However, in the case of the elastomer, the structure is restored to the original state by the elastic recovery, so that the set hardly occurs. As such a typical composition, polyurethane is well known. However, since the combustion gas generated at the time of combustion generates a lot of highly toxic cyan gas and the like, there has been an accident of poisoning death during a fire. In the present invention, since the sheath portion is made of polyester elastomer and the core portion is made of polyester, the toxicity of the combustion gas generated at the time of combustion is low, and therefore, accidental death due to poisoning at the time of fire is unlikely to occur. In this respect, it can be said that it is excellent in safety even if it is used for a vehicle where many people enter in a limited space. In the fiber of the present invention, it is necessary to select a composition having good adhesion between the sheath component and the core component. In a combination of compositions with poor adhesiveness, when the sheath is melted and bonded, the melted adhesive component travels down the core and does not bead at the intersection with the fiber but falls down in the form of a raindrop, causing spots at the bonding points. Probably due to the occurrence and the decrease in the number of adhesion points, as a result, the elasticity of the cushion material is reduced, and the heat resistance is also poor. The cause is presumed to be that the load applied to the bonding point increases. This means that when a base material is used, it is preferable that the base material also selects a composition having good adhesiveness with the adhesive component.

The melting point of the sheath component is 150 ° C. or more and 200
It is below ° C. If the temperature is lower than 150 ° C., the plastic deformation at 70 ° C. becomes remarkable, and the heat resistance is inferior. Furthermore, characteristics that are more unfavorable in terms of manufacturing are added. That is, the difference from the melting point of the core component becomes large, the difference in melt viscosity at the time of spinning becomes remarkable, poor distribution occurs, and the thermal decomposition of the adhesive component also becomes remarkable, so that the adhesive force and the load when the cushion material is used Durability is poor. In addition, in order to prevent fusion between fibers, the fiber must be stretched at a low temperature, and therefore, the core component has poor crimp fastness and thermal stability, and has poor heat resistance and sag resistance when used as a cushion material. Inferior and not preferred. At a temperature of 200 ° C. or higher, when the melting point is higher, the fluidity is improved and the heating temperature is set at 20 ° C. or higher, preferably 3 ° C.
It is necessary to increase the temperature by 0 ° C. or more, and when heat treatment is performed at a temperature of 220 ° C. or more, the thermal stability of the core component and the base material (for example, when polyethylene terephthalate is used) is reduced, and the heat resistance and sag resistance when used as a cushion material Is not preferred. Furthermore, since the polyether-based elastomer contains a large amount of poly (alkylene oxide) glycol, if it is exposed to a temperature of 220 ° C. or more in the air for a long time, it is oxidatively degraded due to thermal decomposition. Is not preferred. In addition, when using a conventionally known cushion material manufacturing apparatus from the viewpoint of manufacturing, there is also a problem that the energy efficiency (usually up to 220 ° C.) of the heat fusion apparatus is extremely reduced.

The core of the fiber of the present invention is made of polyester to reduce the toxicity of the combustion gas at the time of combustion, to suppress the rubber elasticity of the sheath at the time of carding, to smoothly open the fiber, and to provide the above-mentioned reinforcing effect. And that even when a general-purpose polyester fiber is used as the base material, the adhesiveness is good and the durability of the bonding point is good. As a material for forming the core portion, a material which is easily crystallized and a material having a good heat resistance with a melting point of 230 ° C. or more are preferable.

[0010] The crimping form of the present invention is a wave-shaped three-dimensional crimping. A preferred crimping form is an inverted wave type three-dimensional crimp,
It may be mixed with spiral winding. Thermo-adhesive conjugate fibers having mechanical crimps are not preferred because of poor bulkiness and elasticity.
The reason for this is that, in mechanical crimping, the bulk of a card web is low, and the bulk is not increased even if it is thermally bonded. In the case of corrugated three-dimensional crimping, the bulk when made into a card web is high, and when it is thermally bonded, by compressing it to a desired thickness, the synergistic effect of using an elastomer as an adhesive component also appears. , Markedly improved elasticity. The preferred number of crimps of the fiber of the present invention is 5 to 20 / in, and the degree of crimp is 10 to 30%. Thus, the texture changes depending on the number and degree of crimping. Since a relatively fine corrugated three-dimensional crimp shows anti-compression properties and improves cushioning properties, it is preferable to set a desired texture with the balance.

The fiber of the present invention has an initial tensile resistance at 70 ° C. of 10 g / denier or more. Even if the initial tensile resistance at room temperature is high, the initial tensile resistance at 70 ° C. is 10 g /
If it is less than denier, the heat resistance when used as a cushion material is inferior. The heat resistance and durability are better as the initial tensile resistance at 70 ° C. is higher, and a particularly preferable range is 20 g / denier or more. This effect is considered to indicate a reinforcing effect of the core portion. Therefore, it is closely related to the melting point of the sheath portion, and is as high as possible (145 ° C. in the present invention).
Above) Set stretching heat. The sheath / core ratio of the fiber of the present invention is preferably from 80 to 20/20 to 80% by weight. If the sheath portion is less than 20% by weight, the adhesive function is undesirably reduced. On the other hand, if it exceeds 80% by weight, the reinforcing effect as the core part is reduced, the fiber is stretched by the elongation stress at the time of opening, and when the stress is released, the fiber shrinks, causing uneven opening and difficulty in forming the web. there is and Nalco. Furthermore, the reinforcing effect of the core portion when used as a cushion material is reduced, and there is a problem that durability is reduced, which is not preferable. A preferred range is 60-40 / 40-60% by weight. The cross-sectional shape of the fiber of the present invention, in order to express three-dimensional crimping, a core having side-by-side and having a hollow portion,
The core portion has an eccentric hollow portion, and the deformed cross section has a high second moment of area, so that the adhesive component can be used efficiently. Preferred denier of the fiber of the present invention is
If it is less than 1 denier, it becomes difficult to spread the fiber with a normal roller card. If it exceeds 15 denier, the number of fibers is reduced. Denier or less, more preferred denier is 2 to 10 denier. When the preferred cut length of the fiber of the present invention is 30 mm or less, the amount of cotton falling during opening with a normal roller card increases,
If it exceeds 150 mm, it will be difficult to open the fiber.
50 mm is preferred.

The following is an example of a method for producing the fiber of the present invention.
Conventionally known composite spinning method, for example, JP-A-62-29951
Unstretched yarn can be obtained by the method disclosed in Japanese Patent Application Laid-Open No. 4 (1999) -86. It is assumed that polyethylene terephthalate is used for the core component and polybutylene terephthalate / polytetramethylene oxide glycol block copolymer is used for the sheath component. Each component is separately extruded from an extruder by a conventional method, and the sheath components are joined so as to wrap the core component in the spinning head, and are spun from the orifice hole. The spinning temperature at this time is preferably 280 ° C. or more and 290 ° C. or less as a temperature at which polyethylene terephthalate is melted and melt fracture does not occur, and the decomposition of the copolymer is suppressed. Also, the clearance of the slit where the sheath component flows in is made as narrow as possible (for example, 0.2 mm), and the pressure difference at the junction is 50 kg.
/ Cm ² or less, preferably 10 kg / cm ² or less, it is preferable to balance the low melt viscosity of the sheath component and the high melt viscosity of the core component to prevent poor distribution. More preferably, the pressure of the sheath component is one more than the pressure of the core component.
0 to 50 kg / cm ² higher. As the shape of the orifice, a round shape, a C shape, an anchor shape, or the like can be used. The core portions are merged by a side-by-side type method, and before the orifice junction, they are merged by a normal side-by-side type method, and merged so as to wrap the sheath component at the back of the orifice, for example, spun from a C-type orifice hole. . The undrawn yarn thus obtained is then taken off or drawn continuously. In the present invention, the stretching heat is set at a temperature lower by 5 ° C. to 10 ° C. than the melting point of the sheath portion by two-stage stretching. Melting point: 198 ° C. In the polybutylene terephthalate / polytetramethylene oxide glycol block copolymer, the first stage is stretched at 80 ° C. at a stretch ratio of 70 to 80% of the break stretch ratio, and then the yarn temperature is 190 ° C. and the break stretch ratio is 95%. % And 99% or less. The residence time is preferably at least 0.02 seconds in order to improve the crystallization of the core component. When stretched at a temperature higher than the melting point of the sheath component −5 ° C., fusion occurs. In addition, when high-temperature stretching is performed only in one-step stretching (when the orientation and crystallization are not sufficiently performed), fusion occurs. Next, mechanical crimping is applied, and the heat treatment is relaxed in a tow shape.
Three-dimensional crimps are developed and cut into staples, or staples are first cut to a desired length and then relaxed and heat-treated to develop three-dimensional crimps and form staples. The staples thus obtained are mixed with a base material, or 100% of the fibers of the present invention are spread and laminated with a card, and are constrained and heat-fused to a desired thickness to form a cushion material. Since the obtained cushioning material uses the fiber of the present invention, it is excellent in heat resistance, bulkiness, elasticity, comfort and safety.

[0013]

【Example】

Examples 1 to 6 and Comparative Examples 1 to 7 Polybutylene terephthalate (PB) was used as a sheath component.
T) and a polytetramethylene oxide glycol (PTMG) having a molecular weight of 1000 were changed so that the melting point was 1
A block copolymer elastomer pellet at 30 to 220 ° C was prepared. As a core component, polyethylene terephthalate (P) having a melting point of 265 ° C. and an intrinsic viscosity (IV) of 0.63 is used.
ET) and polyethylene terephthalate having an intrinsic viscosity of 0.56 (weight ratio: 50/50).
From the mold orifice, the discharge amount was adjusted so as to be 6 denier with the drawn yarn, and the yarn was spun out to obtain an undrawn yarn at 1,800 m / min. As the core component, the melting point is 265 ° C. and the intrinsic viscosity is 0.
Only polyethylene terephthalate having an intrinsic viscosity of 0.3.
Using only polybutylene terephthalate of No. 80 and a copolymer polyester having a melting point of 195 ° C., which will be described later, and forming a hollow eccentric sea core yarn, the center of the core is shifted from the center of the orifice to eccentricity. In the same state and spun from a C-type orifice in the same manner to obtain an undrawn yarn. The undrawn yarn was drawn in two stages while being aligned. 1st stage, 8
Perform at 75% of the maximum stretching ratio with warm water at 0 ° C.
Stretched at 5%. Continuously, the tow which had been mechanically crimped by a press-type crimper was cut into 51 mm, and then subjected to relaxing heat treatment with hot air at the same temperature as the two-stage stretching temperature to develop three-dimensional crimp and obtain staples. In the characteristics, the initial tensile resistance at 70 ° C. was measured by surrounding the measuring part of Toyo Baldwin's small Tensilon with a hot air oven, loosening the yarn of the attached effective sample, and heating with hot air of 70 ± 2 ° C. for 15 minutes. Then, the hot air circulation is stopped and extended, and the stress is strained. A stress per strain at the time of 100% elongation is obtained from the tangent of the maximum slope of the curve (an average value of n = 50). Is defined as the initial tensile resistance at 70 ° C. The toxicity index of combustion gas is JIS-K-7217.
The amount of each combustion gas (mg / g) measured by the above method is divided by the lethal dose (mg / 101) by inhalation for 10 minutes. Another evaluation method is based on the method of JIS-L-1063.

In order to show that the fiber of the present invention exhibits excellent performance when used as a heat bonding fiber for a cushion material, a base material was prepared by the following method and evaluated as a cushion material. As the base material, polybutylene terephthalate having an intrinsic viscosity of 0.65 and 0.55 was spun from a C-type orifice at 285 ° C. to obtain a 45-denier undrawn yarn. Hot water, second stage tow temperature 200 ° C
And then cut to 64 mm after mechanical crimping, then develop a three-dimensional crimp by free heat treatment with hot air at 165 ° C., 14 denier, strength 4.6 g / denier, elongation 3
6%, initial tensile resistance 46 g / denier, number of crimps 18
A staple (base material) having crests / in, a degree of crimp of 28%, and a hollow ratio of 28% was obtained. Tables 1 and 2 show the characteristics of the obtained staples.
Shown in

[0015]

[Table 1]

[0016]

[Table 2]

The obtained base material and the adhesive fiber are preliminarily mixed with an opener, opened and laminated with a roller card, and a basis weight 1 is obtained.
Adjusted to 200 g / m ² , apparent density 0.03 ~
It was treated with hot air while adjusting the thickness to 0.04 g / m ² to prepare a cushion material. Table 4 shows the properties of the obtained cushion material. Among the evaluation items of the characteristics, apparent bulk density, 70 ° C. compression residual strain, and repetitive compression residual strain are as follows:
It conforms to JIS-L-6401. 70 ° C repeated compressive residual strain was measured using a “servo pulser” manufactured by Shimadzu Corporation in a 70 ° C constant temperature room, with a 150 mm disk and a load of 50 kg, 1H.
Residual strain after repeated compression at 40,000 times in z (residual strain is measured in accordance with JIS-L-6401). Side land (polyester moquette)
And sit for 8 hours (separate for 1 hour in a row, eat 30 minutes in a 4 hour period, then separate for 1 hour in a row). Was evaluated. Combustion gas toxicity index is JI
Each combustion gas amount (mg) measured by the method of SK-7217
/ G) divided by the lethal dose (mg / 101) after inhalation for 10 minutes.

For comparison, as a sheath component,
The mixing ratio of terephthalic acid (TPA) and isophthalic acid (IPA) in the acidic part was changed, and ethylene glycol (EG) was used as a glycol component to block diphenylmethane diisocyanate (DMI) and PTMG at a melting point of 195 ° C. by a conventional method. A copolymer elastomer was prepared.
The core component is PET having a melting point of 265 ° C and an intrinsic viscosity of 0.63.
And a polyethylene terephthalate having an intrinsic viscosity of 0.56 (weight ratio: 50/50), and at 283 ° C., a discharge amount was adjusted from a round cross-section orifice to 6 denier with a drawn yarn, and spinning was performed at 1,800 m / min. Then, the undrawn yarn obtained in the above step was drawn and aligned for two-step drawing. The first stage was performed with warm water at 80 ° C. at 75% of the maximum stretching ratio, and the second stage was stretched at 95% of the maximum stretching ratio at the temperature at which the maximum tow temperature without fusion occurred. Next, the tow to which the mechanical crimp was applied was cut into 51 mm by a press-type crimper and then subjected to a relaxing heat treatment to obtain a staple. For comparison, a staple was obtained in the same manner using a copolymer component of polybutylene terephthalate (PBT) and polytetramethylene oxide glycol (PTMG) having a molecular weight of 1000 (melting point: 190 ° C.) as a sheath component. In addition, in order to compare with mechanical crimping, except that the core portion was made only of PET having an intrinsic viscosity of 0.63 and the sheath portion was made of the above-mentioned copolymerized polyester elastomer having a melting point of 195 ° C., and the relaxation heat treatment was not performed. To obtain staples. Table 3 shows the properties of the obtained staples. A cushioning material was prepared and evaluated in the same manner as in Example, except that the web prepared without mixing the base material was thermoformed by compression at a load of 0.5 g / cm ² without adjusting the apparent density. Table 4 shows the results.

[0019]

[Table 3]

[0020]

[Table 4]

As is clear from Tables 1 to 4, the cushioning material for a vehicle using the heat-adhesive conjugate fiber of the present invention has a compression hardness (Kg) of 25% showing the target of elasticity (from a passing score of 20). Large, smaller than 60), 70 which indicates the aim of heat resistance
℃ Compression residual strain (%) (passing point 30% or less), 70 ° C repeated compressive residual strain (%) (approximately less than 30%), which indicates the endurance of heat resistance, 35 ° C humid / waist fatigue (class)
(Pass; ○ / ○), Combustion gas toxicity index (Passing point 6 or less)
In particular, the cushioning material for vehicles using 100% heat-adhesive conjugate fibers has an apparent density (g / cc) showing the prospect of bulkiness (passing point: 0.03
The following are also excellent. On the other hand, Comparative Example 1 has a problem with heat resistance and durability, and Comparative Example 2 has a problem with elasticity and heat resistance. Comparative Example 3 has problems in elasticity, heat resistance and durability, and comfort. Comparative Examples 4 to 6 had problems in bulkiness, elasticity, heat resistance and durability, and sitting comfort. In Comparative Example 7, since the binder component was urethane, the stuffiness was remarkable, and the toxicity index was unacceptable.

[0022]

The heat-adhesive conjugate fiber of the present invention has good performance such as good adhesion and low toxicity.
When used together with other fibers in cushioning materials, it has excellent heat resistance, elasticity, comfort and safety, and is especially suitable for vehicles and ships. (Furniture, bed) can also provide excellent quality.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-49-35621 (JP, A) JP-A-63-112723 (JP, A) JP-A-4-240219 (JP, A) JP-A-3-3 220316 (JP, A) JP-A-4-272224 (JP, A) JP-B-60-1404 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) D01F 8/14 D04H 1 / 54 B68G 5/00

Claims (1)

(57) [Claims] 1. A polyester elastomer having a sheath component having a melting point of 150 ° C. to 200 ° C., and a core component having a melting point of 22 ° C.
Made of polyester at 0 ° C or higher, with core side
No bi-side composite type or eccentric hollow type
After heat setting, the initial tensile resistance at 70 ° C is 1
A heat-adhesive conjugate fiber characterized by being at least 0 g / denier and having a crimped form of corrugated three-dimensional crimp.