JP2003247122A - Hot-melt adhesive polyester fiber and cushioning material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot-melt adhesive polyester fiber used for heat resistant cushioning materials in applications exposed under relatively high temperature such as vehicle, and provide the cushioning material. <P>SOLUTION: The hot-melt adhesive polyester fiber is constituted by using a polymer prepared by melting and mixing a modified polypropylene terephthalate (polyester A) having 180-220°C melting point and a polyester B having ≤180°C melting point in a weight mixing rate A/B=10/90-80/20. The cushioning material is constituted by adhering a basic fabric with the hot-melt adhesive fiber. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester heat-bonding fiber and a cushioning material using the same.

More specifically, the present invention relates to a polyester heat-bonding fiber and a cushioning material used as a cushioning material having heat resistance for applications such as those for vehicles which are frequently exposed to a relatively high temperature environment.

[0003]

2. Description of the Related Art Recently, in a non-woven fiber structure used as a fiber cushioning material for roofing materials, automobile interior materials, carpet base materials, cushioning materials, etc., the constituent fibers of the fiber structure (hereinafter referred to as base material fibers) The heat-bonding fiber has been widely used for the purpose of bonding between each other.

As a base material fiber of a fiber cushion material, a relatively inexpensive and excellent polyester fiber is often used, and a heat-bonded fiber for adhering the base material fiber is also made of a polyester material because of its ease of recycling. Many things are used.

For example, in a core-sheath type composite fiber in which the polyester heat-bonding fiber has a core component of polyethylene terephthalate (hereinafter referred to as PET) and a sheath component is a low melting point PET copolymerized with an isophthalic acid (hereinafter referred to as IPA) component, The copolymerization rate of the IPA component of the low melting point polyester is designed according to the temperature at which the heat-bonding fibers are bonded.

Generally, when the copolymerization rate of IPA increases, the melting temperature of the copolymerized PET measured by a differential scanning calorimeter (hereinafter referred to as DSC) decreases. In this case, the melting temperature means a temperature corresponding to an endothermic peak measured by DSC. For example, when the melting temperature of homo-PET having no copolymerization component is measured by DSC, an endothermic peak is confirmed in the range of 250 to 260 ° C., but IPA 20 mol% copolymerized PET
Then, the endothermic peak tends to decrease to about 210 ° C., and the temperature region where the endothermic peak is observed tends to be widened. Further, in the case of 40 mol% IPA-copolymerized PET, the melting temperature drops to about 110 ° C., but the melting temperature region becomes too wide, and the endothermic amount at the time of melting drops, and the melting peak cannot be observed. In this case, DSC
Since it becomes impossible to measure the melting temperature, the melting temperature is measured with a melting point microscope or the like.

On the other hand, for example, when a cushion material having PET as a base material is heat-bonded by heat-bonding raw cotton, it is heat-treated at a temperature of 220 ° C. or lower in consideration of heat resistance of the base material. In order to cope with such a heat-bonding temperature, JP-A-58-419
No. 12, JP-A-2-139466, JP-A-6
In JP-A-280147 and the like, a method is used in which IPA 40 mol% copolymerized PET is used as a heat-adhesive component to lower the melting temperature to about 110 ° C. for use. But,
As described above, when 40 mol% of IPA is copolymerized, the melting temperature is lowered, but the temperature range is widened, the melting start temperature is significantly lowered, and melting is gradually started from around 70 ° C.

As described above, the polyester heat-bonded raw cotton is generally I in order to enable bonding at a practical bonding temperature.
Copolymerized PET obtained by copolymerizing PA in an amount of 30 to 50 mol% is widely used, but the melting start temperature of the heat-adhesive component is 70%.
Since the temperature is lowered to -80 ° C, if the heat-bonded cushion material is exposed to an environment of 90-100 ° C, a part of the adhesive point is remelted, the adhesive point is removed, and the cushion material is deformed. It has drawbacks.

Therefore, in the case where the material is exposed to an environment of 90 to 100 ° C., such as the use as a ceiling material for automobiles, the polyester heat-bonded raw cotton made of simple IPA copolymer PET has a heat resistance of the cushion material. I couldn't use it.

In order to improve the heat resistance, JP-A-7-119
No. 011 and Japanese Patent Laid-Open No. 2000-160430 propose special copolyesters, but all of them require a special component to be used as a copolymerization component, which reduces raw material costs and complicated polymer production steps. Therefore, there is a problem that the manufacturing cost becomes high.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyester thermal bonding fiber and a cushioning material used for a cushioning material having heat resistance, which cannot be achieved by the above-mentioned prior art, at low cost and easily. is there.

[0012]

In order to achieve the above object, the present invention has the following constitution.

That is, the polyester heat-bonded fiber of the present invention comprises a modified polypropylene terephthalate (polyester A) having a melting temperature of 180 to 220 ° C. and a melting temperature of 1
Polyester B of 80 ° C. or lower has a weight mixing ratio A / B =
A polyester heat-bonding fiber comprising a polymer melt-mixed within a range of 10/90 to 80/20.

The cushioning material of the present invention is a cushioning material in which the base material fibers are bonded by the above-mentioned polyester thermal bonding fiber according to the present invention.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester thermal bonding fiber of the present invention will be described in detail below.

The thermoadhesive fiber of the present invention has a melting temperature of 1 and a modified polypropylene terephthalate (hereinafter referred to as polyester A) having a melting temperature of 180 to 220 ° C.
Polyester B having a temperature of 80 ° C. or lower has a weight mixing ratio A / B.
= 10/90 to 80/20, which is a polyester heat-bonding fiber composed of a polymer obtained by melt-mixing.

In the present invention, the melting temperature means the temperature corresponding to the endothermic peak that can be confirmed in the melting curve measured by DSC.

Further, in the melting curve measured by DSC, the endothermic peak is not confirmed means the temperature measured by a melting point microscope.

The main constituent of polyester A having a melting temperature of 180 to 220 ° C. must be a modified polypropylene terephthalate composed of repeating units of propylene terephthalate. Generally, the melting temperature of unmodified polypropylene terephthalate (hereinafter referred to as PPT) is 230 to 235 ° C., and the melting temperature must be lowered to use it as the polyester A of the present invention. The melting temperature of PPT can be copolymerized similarly to PET. As the copolymerization component, bifunctional carboxylic acid components such as IPA, phthalic acid, adipic acid and sebacic acid, ethylene glycol, diethylene glycol,
A bifunctional glycol component such as butylene glycol or polyethylene glycol is preferable, and IPA is more preferably copolymerized in view of the production cost and the heat resistance of the polymer. Further, two or more kinds of copolymerization components may be used as long as the effects of the present invention are not impaired.

Polyester B having a melting temperature of 180 ° C. or lower
Is preferably a copolymer of PET, PBT, or PPT with at least one compound, and the copolymerization components include IPA, phthalic acid, adipic acid, sebacic acid, ethylene glycol, diethylene glycol, propylene glycol, butanediol, Polyethylene glycol and polybutylene glycol are preferred. In particular, IPA whose main constituent is a repeating unit of ethylene terephthalate in view of the price of raw materials and the ease of manufacturing method
Copolymerized PET is more preferred. Two or more kinds of copolymerization components may be used as long as the effects of the present invention are not impaired.

According to the knowledge of the present inventors, the polymer B is a component for adhering the cushion material, and the polymer A is a component for suppressing remelting of the adhering point in the range of 90 to 100 ° C.
Is thought to be working. When the melting temperature of the polymer A is lower than 180 ° C., the function of suppressing remelting is deteriorated, and remelting of the bonding point of the thermally bonded cushioning material, which is the object of the present invention, cannot be prevented, which is not preferable.

When a cushion material having a particularly large thickness is manufactured, it is difficult for heat to be transferred to the center of the cloth,
Even if heated with a hot air heater of 220 ° C, if the heating time is short, the temperature of the center of the fabric is 20% lower than the temperature set by the heater.
The temperature rises to as low as -40 ° C, and the adhesive state of the cushion material is significantly reduced. In general, equipment for treating a polyester material can raise the temperature to about 220 ° C. as a level at which the base material polyester is not melted, but the heating time is about 2 to 5 minutes in consideration of productivity. The melting temperature of the polymer A must be 220 ° C. or lower so as not to reduce the adhesiveness in the production under such conditions. Therefore, the melting temperature of polymer A is 1
It is important that the temperature is within the range of 80 to 220 ° C, preferably 185 to 215 ° C. To obtain a copolymerized PBT in the melting temperature range by copolymerizing IPA, IPA
It becomes possible by setting the copolymerization rate to 5 to 25 mol%,
More preferably, it is 10 to 20 mol%.

When the melting temperature of the polymer B exceeds 180 ° C., the adhesion of the cushion material is suppressed and the adhesiveness is deteriorated, which is not preferable. Therefore, it is important that the melting temperature of the polymer B is 180 ° C. or lower, and preferably 160 ° C. or lower.

Particularly, because of the price of raw materials and the ease of manufacturing method, I
When PA copolymerized PET is used, the melting temperature can be 180 ° C. or lower by setting the IPA copolymerization rate to 25 to 50 mol%, but more preferably 30 to 40 mol%. The polymers A and B may be added with a matting agent such as titanium dioxide or an additive such as a lubricant.

The weight mixing ratio of the polymer A and the polymer B is 10/90 to 80/20. When the ratio of the polymer A component is less than 10%, the ratio of the polymer A component that suppresses the remelting of the bonding points is too low, and the remelting of the bonding points of the heat-bonded cushioning material which is the object of the present invention is prevented. It is not possible because it cannot be done. On the other hand, if it exceeds 80%, the ratio of the polymer B component having the adhesive property at low temperature is excessively lowered, and the adhesiveness at the time of thermal adhesion is deteriorated, which is not preferable. The weight mixing ratio of the polymer A and the polymer B is more preferably 20/80 to 60/40. The weight ratio here is the weight ratio of the polymer A and the polymer B,
Polymers of other components may be mixed as long as the effects of the present invention are not impaired.

It is known that when two kinds of polyesters are melt-mixed, a transesterification reaction occurs between the polyesters to form a random copolymer through a block copolymer. However, in the present invention, the effect is exhibited by not randomly copolymerizing both polyesters in the mixed polyester.

The heat-bonded fiber of the present invention is preferably one in which at least a part of the melt-mixed polymer of polymer A and polymer B (hereinafter referred to as a heat-bonded component) is exposed around the cross section of the fiber, and it is concentric or eccentric. The core-sheath type, side-by-side type, sea-island type, and the like can be used. If the concentric core-sheath type is used, the spinnability is good, and if the eccentric type is used, the latent crimping property is obtained. Therefore, it is preferable to select an appropriate composite form according to the application.

In the case of the core-sheath form, it is preferable to use polyester having a melting temperature of 220 ° C. or more as the core component and the heat-adhesive component as a sheath component. Is preferred. As the core polyester, polyethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate can be preferably used. In addition, recycled polyester can be used from the viewpoint of resource reuse and environmental protection. Furthermore, the core component may be formed of a mixed polymer of two or more kinds within the range where the effect of the present invention is not impaired, and the core component may be in a bimetal composite form or the like. A matting agent such as titanium dioxide or an additive such as a lubricant may be added to the core component. Core-sheath composite ratio is 20/80 to 80/20
Is preferable, and more preferably 40/60 to 60/40.

The shape of the cross section of the heat-bonding raw cotton (fiber) of the present invention may be circular or irregular. The thermoadhesive fiber of the present invention may be used without being drawn after being spun, or may be used after being drawn, and may be crimped if desired. Further, it can be cut into a desired fiber length. The single fiber fineness of the heat-bonding fiber of the present invention is 50d.
It is preferably tex or less, and more preferably 10 dtex or less.

The cushion material of the present invention is obtained by adhering the base material fibers with the thermal adhesive fiber of the present invention, and the weight ratio of the thermal adhesive fiber contained in the cushion material can be selected according to the application. Further, as long as the effect of the present invention is not impaired, it may be used in combination with a heat-bonding fiber other than the heat-bonding fiber of the present invention.

The matrix fiber used for the cushioning material of the present invention is preferably polyester fiber in terms of cost and recyclability. The base material fiber varies depending on the use, but generally, for example, if the cushioning property and bulkiness are required, 6 to 17 dtex polyester fiber, or
If soft texture is required, 1-6 dte
The polyester fibers of x are preferably used as the matrix fibers. Further, from the viewpoint of resource reuse and environmental protection, a base material fiber made of recycled polyester may be used. Further, two or more kinds of matrix fibers may be used. These base fibers have a mixing ratio of base fiber / thermal bonding fiber of 20/80 to 8
It is advisable to mix in the range of 0/20% by weight.

[0032]

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

The characteristic values defined in the present invention are obtained by the following methods. (1) Melting temperature: a. Differential scanning calorimeter (DSC) under nitrogen stream at 10 ℃
It was measured at a temperature rising rate of / min.

B. When the melting temperature could not be confirmed by the above DSC, the melting start temperature and the melting completion temperature were observed using a melting point microscope at a temperature rising rate of 10 ° C./min, and the melting temperature was determined by the following formula.

Melting temperature (° C.) = (Melting start temperature + melting completion temperature) / 2 (2) Heat resistance evaluation: cushion material 130 mm × 25 m
The test sample obtained by cutting into a shape of m × 10 mm was left for 1 hour in a hot air dryer at 90 ° C. (standing),
The sample was left at room temperature (about 25 ° C.) for 30 minutes (standing), and the thickness Li (mm) of the sample was measured.

The heat resistance was calculated from the thickness 10 (mm) of the sample before heat treatment by the following formula.

Heat resistance = {(Li-10) / 10 × 100} (%) As for the superiority and inferiority of the heat resistance, a heat resistance of less than 20% is good, and a heat resistance of 20.
% Or more was judged as defective. Examples 1 to 4 Polypropylene terephthalate chips (polyester A) having an intrinsic viscosity [η] = 0.85 obtained by copolymerizing isophthalic acid in an amount shown in Table 1 were copolymerized with isophthalic acid in an amount shown in Table 1. IPA copolymerized PET chips (polyester B) having an intrinsic viscosity [η] = 0.62 were mixed in the form of chips at the weight mixing ratio shown in Table 1.

Then, the mixed chip polymer was used as a sheath component, polyethylene terephthalate having an intrinsic viscosity [η] = 0.65 was used as a core component, and the core-sheath ratio was 50/50.
It was discharged from the spinneret at 0 ° C. and the undrawn yarn was wound at 1500 m / min. Then, the undrawn yarn is heated in an 80 ° C. hot bath for 3.
After being stretched 3 times, mechanical crimping was applied and then cut into 51 mm.

Next, polyethylene terephthalate short fibers having a hollow section three-dimensional crimp of 6.6 dtex and a fiber length of 64 mm were used as the base material fibers, and the resulting heat-bonded raw cotton was mixed at a weight ratio of 50/50 to open a card. After the fibers were woven, webs were laminated to give a basis weight of 800 g / m ^2, and while being compressed to a thickness of 10 mm, thermoformed with hot air at 200 ° C. for 2 minutes and then cooled to prepare a cushion material. Table 1 shows the heat resistance evaluation results of the obtained cushioning materials. The heat resistance was good. Comparative Examples 1 to 4 Thermal bonding raw cotton was obtained in the same manner as in Examples 1 to 5, except that the polymer A, the polymer B, and the mixing ratio of the polymer A / polymer B were as shown in Table 2. Table 2 shows the heat resistance evaluation results of the cushion materials produced using the obtained heat-bonded raw cotton in the same manner as in Examples 1 to 5. The heat resistance was poor. In particular,
In Comparative Examples 3 and 4, heat resistance could not be evaluated because the cushion material had defective adhesion at the stage of producing the cushion material.

[0040]

[Table 1]

[0041]

[Table 2]

[0042]

Industrial Applicability According to the present invention, it is possible to provide a polyester heat-bonding fiber and a cushioning material which are used as a cushioning material having high temperature heat resistance for applications such as those for vehicles which are frequently exposed to a relatively high temperature environment. .

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3B096 AD04 BA01                 4J002 CF00X CF05W CF06X GK00                 4L035 EE01 FF05 FF06                 4L041 AA07 BA02 BA06 BA21 BD03                       BD11 CA06 CA12 CA14 DD01                       DD05                 4L047 AA21 AA27 AB10 BA09 BA23                       BB06 CC16

Claims (5)

[Claims] 1. A weight mixing ratio A of modified polypropylene terephthalate (polyester A) having a melting temperature of 180 to 220 ° C. and polyester B having a melting temperature of 180 ° C. or less.
/ B = 10/90 to 80/20, wherein the polyester heat-bonded fiber is constituted by using a polymer melt-mixed within the range. 2. Polyester A contains 5 to 25 isophthalic acid.
The polyester heat-bonded fiber according to claim 1, which is a modified polypropylene terephthalate copolymerized by mol%. 3. Polyester B contains isophthalic acid in an amount of 25 to 5
The polyester heat-bonded fiber according to claim 1 or 2, which is a modified polyethylene terephthalate copolymerized with 0 mol%. 4. The polyester heat-bonded fiber has a core-sheath type composite fiber structure, and the sheath component of the composite fiber is a polyester A having a melting temperature of 180 to 220 ° C. and a melting temperature of 180 ° C. or less. Polyester B is a weight mixing ratio A / B
3. A polymer which is melt-mixed within the range of 10/90 to 80/20.
Alternatively, the polyester heat-bonded fiber according to item 3. 5. A cushioning material formed by bonding base material fibers with thermal bonding fibers, the thermal bonding fibers comprising:
A modified propylene terephthalate (polyester A) having a melting temperature of 180 to 220 ° C. and a polyester B having a melting temperature of 180 ° C. or less have a weight mixing ratio A / B = 10/90.
A cushioning material comprising a polymer melt-mixed within a range of 70/30 to 70/30.