JP3129460B2 - Thermal adhesive fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-adhesive fiber which is particularly useful for cushioning materials having excellent heat resistance, durability, comfort and safety.

[0002]

2. Description of the Related Art As a heat-adhesive fiber, a polyester-based non-elastomeric low-melting-point polymer having a sheath portion is known, but when it is applied to a cushion material, its 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, a hollow core component (JP-A-62-299514, JP-A-63-2649)
No. 15 is proposed, but it is bulky,
The heat resistance is insufficient. In addition, since the adhesive component is hard, appropriate elasticity is required to be controlled by crimping of the base material. Therefore, even when used at room temperature, crimping is promoted, and furthermore, destruction of the bonding point is prevented. There is a problem that it is difficult to maintain elasticity because of promotion. From the viewpoint of lightness, olefin-based heat-adhesive 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 toxicity of combustion gas (toxicity index)
Polyesters are also preferred because they have toxicity as low as olefins. However, olefins are susceptible to self-oxidation and may be decomposed and ignited when exposed to heat storage conditions for a long time, and are not superior to polyesters. Polyester elastomer fibers are
It is known in 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-mentioned problems, and provides a heat-adhesive fiber suitable for use in cushioning materials having excellent heat resistance, elasticity, safety, and comfort. Is the subject.

[0004]

Means for Solving the Problems The present invention, 200 ° C. sheath component melting point 0.99 ° C. or more of the following polyester elastomer, a fiber core component consists of melting point 220 ° C. or more polyester, core portion of the fiber It has a hollow part,
The thermoadhesive fiber is characterized in that the fiber is stretched in two steps and then heat set, and the fiber has an initial tensile resistance at 70 ° C. of 10 g / denier or more.

[0005] The polyester elastomer as a sheath component of the present invention is a polyester copolymer elastomer.
Is preferred. More specifically, aromatic dicarboxylic acids, aliphatic diols, and poly (alkylene oxide) glyco-
Terephthalic acid,
1,4 butanediol and a number average molecular weight of about 300 to
Elastomers consisting of 6000 poly (alkylene oxide) glycols are preferred. If necessary, one or both of a dicarboxylic acid other than terephthalic acid and a low molecular weight diol other than 1,4 butanediol can be added. As the dicarboxylic acid other than the terephthalic acid,
Examples include isophthalic acid, phthalic acid, adipic acid, and sebacic acid. Examples of diol components other than 1,4 diol include ethylene glycol, trimethylene glycol, and pentamethylene glycol. it can. Further, 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. Particularly preferred is poly (tetramethylene oxide) glycol. A particularly preferred polyester polyether copolymer elastomer used in the present invention is JP-B-53-19 / 1978.
No. 638, Japanese Patent Publication No. 55-27697, and the like, and copolymerized polyesters containing polybutylene terephthalate and polytetramethylene oxide glycol as main components. Other additives include third components such as various copolymer components, cross-linking agents, colorants, 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.

The polyester forming the core component of the present invention includes polyethylene terephthalate, polybutylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene naphthalate, and copolyesters thereof. Etc. can be exemplified. In addition, as a third component, various copolymer components, coloring agents, light stabilizers, matting agents, etc. are added in a range that does not generate toxic gas at the time of combustion, does not promote hydrolysis, and does not easily cause plastic deformation at 60 ° C. or less. it can.

[0007]

The fiber of the present invention is a heat-adhesive fiber,
A core structure is required, and a portion of the sheet portion that comes into contact with the base material fiber is adhesively bonded as a melted sheet component. The sheet component serving as the adhesive component is a polyester-based elastomer. In the case of non-elastomer, when the compressive load of the cushioning material exceeds the stress supported by the crimp of the base fiber, the bonding point is deformed, and the bonding point is plastically deformed and the structure returns to its original state. Because it disappears, a significant sag occurs. In the case of the elastomer, since the structure is restored to the original state by the elastic recovery, sag 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. In this respect, it can be said that the safety is excellent even when used for a vehicle having many people 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 the case of a combination of compositions having poor adhesiveness, when the sheet is melted and bonded, the melted bonding component propagates down the core and does not bead at the intersection with the base material, but falls down in the form of a raindrop and the bonding point This may be due to the occurrence of uneven spots and a decrease in the number of adhesion points. As a result, the elasticity of the cushion material is reduced, and the heat resistance and durability are inferior. The cause is presumed to be that the load applied to the bonding point increases. For this reason, 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. Further, in order to prevent fusion between the fibers, the fiber must be stretched at a low temperature, so that the thermal stability of the core component is inferior, and the heat resistance when used as a cushion material is inferior. 20
At a temperature of 0 ° C. or higher, when the melting point is high, the fluidity is improved, and in order for the melt to sufficiently surround the intersection, the heating temperature must be 20 ° C. or higher, preferably 30 ° C. or higher than the melting point. When the heat treatment is performed at a temperature of 220 ° C. or higher, the thermal stability of the core component and the base material (for example, when polyethylene terephthalate is used) decreases, and the heat resistance and sag resistance of the cushion material are inferior. Furthermore, since the polyether-based elastomer contains a large amount of poly (alkylene oxide) glycol, it can be left in the air for a long time.
Exposure to a temperature of not less than ° C. results in oxidative degradation due to thermal decomposition. 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 a very reasonable heat fusion apparatus decreases.

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 and durability of the cushion material are inferior, which is not preferable. 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 sheet portion, and it is necessary to set the stretching heat at a temperature as high as possible (145 ° C. or higher in the present invention).

[0010] The core of the fiber of the present invention is made of polyester to reduce the toxicity of combustion gas during combustion.
Smooth fiber opening by suppressing the rubber elasticity of the sheet part during dating, capable of exerting the above-mentioned reinforcing effect, good adhesiveness and durable adhesion point even when using general-purpose polyester fiber as the base material It is possible to exemplify that the property is good. As a material for forming the core portion, a material that is easily crystallized and a material having a good heat resistance with a melting point of 230 ° C. or more are preferable, and examples thereof include polyethylene terephthalate. Sheet of the fiber of the present invention /
The core ratio is preferably 80 to 20/20 to 80 weight ratio.
If the sheet portion is less than 20% by weight, the adhesive function is undesirably reduced. On the other hand, when the content exceeds 80% by weight, the reinforcing effect as the core part is reduced, and 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. May be. Furthermore,
When the cushioning material is used, there is a problem that the reinforcing effect of the core portion is reduced, and the durability is lowered.
A preferred range is a 40-60 / 60-40 weight ratio. If the denier of the fiber of the present invention is less than 1 denier, it becomes difficult to open the fiber with a normal roller card.
If it exceeds 15 denier, the number of fibers will decrease and the adhesion point will decrease, and the hardness retention will decrease. Therefore, 1 denier or more and 15 denier or less, more preferably 2 denier or more will be used. , 10 denier or less. When the preferred cut length of the fiber of the present invention is less than 30 mm, a normal roller marker is used.
In the case of fiber opening at the time of opening, the amount of cotton fall increases, and if it exceeds 150 mm, it becomes difficult to open the fiber, so that 30 to 150 mm is preferable. As for the crimp of the fiber of the present invention, the crimp form is mechanical crimp, and the number of crimps is 8 to
20 pieces / in and a degree of crimp of 10 to 20% are preferred because they are opened by card opening and are less likely to cause spots. The form of the fiber of the present invention is such that the core portion has a hollow portion, and a form in which the adhesive component can be used efficiently, for example, a cross-shaped shape is particularly preferable.

The following is an example of the method for producing the heat-adhesive fiber of the present invention. Conventionally known composite spinning methods, for example,
An undrawn yarn can be obtained by the method described in Japanese Patent Application Laid-Open No. 299514/1992. Polyethylene terephthalate, sealant as core component
It is assumed that a polybutylene terephthalate / polytetramethylene oxide glycol block copolymer is used as the polymer component. Each component is separately extruded from the 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 is not generated and the decomposition of the copolymer is suppressed. Also, the clearance of the slit portion into which the sheath component flows is made as narrow as possible (for example, 0.2 mm) so that the pressure difference at the merging portion is 50 kg / cm ² or less, preferably 10 kg / cm ² or less. It is preferred to balance the low melt viscosity of the components with the high melt viscosity of the core components to prevent poor distribution. More preferably, the pressure of the sheath component is 10 to 50 kg / cm ² higher than the pressure of the core component.
As the shape of the orifice, a round shape, a C shape, an anchor shape, or the like can be used.
The undrawn yarn thus obtained is then taken off or drawn continuously. The stretching heat is set at a temperature 5 ° C. to 10 ° C. lower than the melting point of the sheet portion by two-stage stretching. Melting point 198
In the case of polybutylene terephthalate / polytetramethylene oxide glycol block copolymer,
Stretching at 70 to 80% of the breaking stretching ratio at
Next, at a yarn temperature of 190 ° C., 95% or more of the breaking draw ratio 9
The stretching heat setting is preferably 9% or less. The residence time is preferably at least 0.02 seconds in order to improve the crystallization of the core component. When the film is stretched at a temperature higher than the melting point of the sheet component minus 5 ° C., it fuses. 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. Preferably, in order to preheat and apply crimp and fix crimp, it is then restrained and set. Subsequently, the staple is cut into a desired length. When using in a tow shape, take it off without cutting. The staples thus obtained are mixed with the base material,
Alternatively, 100% of the fiber of the present invention is spread and laminated with a card, and is 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 and durability, elasticity, comfort and safety.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Polybutylene terephthalate as a sheath component
(PBT) and polybutylene isophthalate (PBI)
By changing the composition ratio of polytetramethylene oxide glycol (PTMG) having a molecular weight of 1,000 and melting point of 130
A block copolymer elastomer pellet at ~ 220 ° C was prepared. As the core component, polyethylene terephthalate (PET) having a melting point of 265 ° C. and an intrinsic viscosity of 0.63 is used, and at 283 ° C., the weight ratio of the sheet and the core is changed, and the drawn yarn becomes 4 denier. 1300
An undrawn drawn yarn was obtained at m / min. The undrawn yarn was drawn in two stages while being aligned. 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 a temperature at which the maximum tow temperature did not fuse and at a part lower temperature at 95% of the maximum stretching ratio. . The tow to which mechanical crimping was applied continuously by a press-type crimper was cut into 51 mm to obtain a staple. In the characteristics, the initial tensile resilience at 70 ° C. was determined by enclosing the measuring section of a small Tensilon manufactured by Toyo Boldwin Co., Ltd. in a hot-air oven, and setting a sample with an effective sample length of 25 mm attached to a thread on the chuck. The gap between the chucks was reduced to 2 mm, the yarn of the sample was loosened, and heated with hot air of 70 ± 2 ° C. for 15 minutes. Then, the hot air circulation was stopped and extended, and the stress-strain curve was determined. The stress per denier at 100% elongation from the tangent line is determined (average value of n = 50), and this value is defined as the initial tensile resistance at 70 ° C. The toxicity index of combustion gas is JIS-K-72
It shows the integrated value of the value obtained by dividing each combustion gas amount (mg / g) measured by the method of No. 17 by lethal dose (mg / 10l) 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-adhesive fiber for a cushion material, a base material was prepared by the following method and evaluated as a cushion material. As the base material, polyethylene 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. 80 ° C hot water, 2nd stage tow temperature 200 ° C
After applying mechanical crimping, the film was cut to 64 mm, and then subjected to free heat treatment with hot air at 165 ° C. to develop three-dimensional crimping, 14 denier, strength 4.6 g / denier, and elongation. Degree 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.

[0014]

[Table 1]

[0015]

[Table 2]

The obtained base material and the adhesive fiber are preliminarily mixed with an opener and opened and laminated with a roller card.
Adjusted to 200 g / m ² , apparent density 0.03 ~
It was treated with hot air while adjusting the thickness to 0.04 g / cm ³ 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 cyclic compressive residual strain was measured at 150 ° C disc with a load of 50 kg and 1 Hz using a “Servo Pulser” manufactured by Shimadzu Corporation in a 70 ° C constant temperature room.
And the residual strain after repeated compression for 24 hours (residual strain is measured according to JIS-L-6401), and an accelerated model of a wearing test in a state where the vehicle is heated is assumed. Also, in a room at 30 ° C. and 75% RH, the side material (polyester moquette) is hung on a cushion material cut and formed into a bucket sheet and allowed to sit for 8 hours (separated for 1 hour in a row, 30 minutes in 4 hours) Take 1 for 1 hour in a row
Separation) Wearing feeling is evaluated by questionnaire, and evaluation of sitting comfort such as stuffiness and waist fatigue (○ is 4-5 class, △ is 2-3)
Grade, × represents first grade. ) Was done. The toxicity index of the combustion gas is shown as an integrated value of the value obtained by dividing each combustion gas amount (mg / g) measured by the method of JIS-K-7217 by a lethal dose (mg / 10l) by inhalation for 10 minutes.

For comparison, as a sheath component,
The mixing ratio of terephthalic acid (TPA) and isophthalic acid (IPA) was changed as an acid component, and ethylene glycol (EG) was used as a glycol component. C. and 195.degree. C. polyesters were prepared. A block copolymer elastomer having a melting point of 195 ° C. of diphenylmethane diisocyanate (DMI) and PTMG was prepared by a conventional method. The core ingredients are
Using PET having a melting point of 265 ° C. and an intrinsic viscosity of 0.63, 28
At 3 ° C., the discharge amount was adjusted to 4 denier with the drawn yarn, and the undrawn yarn obtained at 1,300 m / min was then removed.
It was stretched in two steps. The first stage was performed at 80% of warm water at 75% of the maximum stretching ratio, and the second stage was stretched at a temperature at which the maximum tow temperature without fusing was reached at 95% of the maximum stretching ratio.
Next, the characteristics of the staples obtained by cutting the tow having been subjected to mechanical crimping to 51 mm with a press-type crimper are shown in Tables 2 and 3.
Shown in A cushion material was prepared and evaluated in the same manner as in the example. Table 5 shows the results.

[0018]

[Table 3]

[0019]

[Table 4]

[0020]

[Table 5]

As is apparent from Tables 1 to 5, the cushioning material for vehicles using the heat-adhesive fiber of the present invention has a compression hardness (Kg) of 25% (approximately larger than a passing score of 20) showing the target of elasticity. ), 70% compression residual strain (%) indicating a target of heat resistance (passing point 30% or less), repeated compressive residual strain (%) indicating a target of durability (must be smaller than 10). 70 ° C cyclic compressive residual strain (%) showing the target of heat resistance and durability
(Must be smaller than the passing point of 30.), 35 ° C. humidification / waist fatigue (grade) (passing: ／/ ○), and combustion gas toxicity index (passing point of 6 or less) were satisfied. On the other hand, Comparative Example 1 has a problem in terms of heat resistance and durability, Comparative Examples 2 and 3 have a problem in terms of elasticity, heat resistance, and durability, and Comparative Example 4 has a problem in Comparative Example 1. Had similar problems. Comparative Example 5 had problems in heat resistance and durability. In Comparative Example 6, since the binder was urethane, the moisture permeability and water permeability were poor, so that the stuffiness at 35 ° C. was poor, and the toxicity index was also unacceptable.

[0022]

The heat-adhesive fiber of the present invention has good adhesion when used together with other fibers in a cushioning material or the like.
In addition, because of its excellent performance such as low toxicity, it has excellent heat resistance, elasticity, comfort, and safety, and is particularly suitable for vehicles and ships, and also for furniture and beds. It will be suitable.

──────────────────────────────────────────────────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-B 60-1404 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) D01F 8/14 D04H 1/54

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.
A fiber consisting of 0 ℃ more polyesters, the fibers
Has a hollow part, and is stretched in two steps to be set after heat.
And a fiber having an initial tensile resistance at 70 ° C. of 10 g / denier or more.