JPH0598516A - Polyester heat-bondable composite fiber - Google Patents

Abstract

(57) [Summary] [Purpose] A polyester system that is excellent in cushioning properties, has excellent durability and stability, and is highly breathable, and is suitable for producing stable and evenly manufactured cushioning materials in a simple process. Provide a heat-bondable fiber. A composite fiber comprising a polyester having a melting point of 200 ° C. or higher and a polyether ester block copolymer (P), wherein the P component is A: terephthalic acid 40-9.
0 mol%, an acid component having 10 to 40 mol% of isophthalic acid, B: a glycol component mainly containing 1,4-butanediol, C: a poly (alkylene oxide) glycol component having an average molecular weight of 1000 to 4000, and C The copolymerization amount Wc of the components is 40 to 55 wt%, the copolymerization ratio A _I of isophthalic acid is larger than 60-Wc, and the intrinsic viscosity is 1.
0 or more, the melting point is 160 to 200 ° C., the oxidative decomposition initiation temperature is 200 ° C. or more, and the P component has a fiber cross-section ratio of 40%.
Thermoadhesive conjugate fiber occupying the above.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester-based thermoadhesive conjugate fiber, and more particularly to a thermoadhesive conjugate fiber suitable for adhering polyethylene terephthalate (hereinafter sometimes referred to as PET) fibers. is there.
More specifically, the present invention relates to a heat-adhesive conjugate fiber which, when used as a non-woven fabric made of polyester fiber or a cushioning material such as cotton wool, has excellent elastic properties (compression property, extension property) and shape retention.

[0002]

2. Description of the Related Art At present, in the field of cushion materials such as furniture and beds, urethane foam, polyester fiber stuffed cotton, resin cotton or polyester cotton bonded with polyester fiber are used.

However, the urethane foam has the problems that it is difficult to handle chemicals and the like used during the manufacture and that the CFCs are discharged. In addition, the compression characteristics of the obtained urethane foam are hard in the initial stage of compression and show a unique characteristic of suddenly sinking, resulting in poor cushioning. Often not liked as a material. Further, since the polymer is soft and foamed, there is a drawback that the density must be increased in order to exhibit the resilience against compression. In addition, since the fibers and structure are not fixed in the polyester fiber wadding, there is a drawback that the shape and shape of the cotton stuff may collapse during use, or the fibers may move or the crimp may deteriorate, resulting in a large decrease in bulk and repulsion. ..

On the other hand, resinous cotton or hard cotton in which polyester fibers are bonded with a resin or a low-melting polymer (for example, Japanese Patent Laid-Open No. 58-58).
-31150 gazette), the adhesion is weak, the adhesion part has low durability, the adhesion is destroyed during use, and the form and the repulsion property are greatly reduced. There are drawbacks such as not being able to do so. In order to improve the cushioning property, a cushioning material in which entangled parts of polyester fibers are adhered with a urethane foam binder is proposed as in Japanese Patent Laid-Open No. 62-102712, but since it is impregnated with a solution type urethane, it is processed. There are problems that it is easy to be spotted and it is troublesome to handle, the adhesion between urethane and fiber is low, it is easily broken when the entanglement part is largely deformed due to the low elongation of the binder, and the durability is low. is there.

[0005]

SUMMARY OF THE INVENTION In view of the above problems of the prior art, the present invention provides a cushioning material having excellent cushioning properties, excellent durability and stability, and high breathability in a simple process. It is an object of the present invention to provide a polyester-based heat-adhesive conjugate fiber that is suitable to be manufactured without any treatment.

[0006]

Means for Solving the Problems As a result of intensive studies for achieving the above-mentioned object, the present inventor has found that a polyether ester block copolymer composed of specific constituents and having specific properties is heated. It has been found that when a polyester-based heat-adhesive conjugate fiber as an adhesive component is applied to a cushion material, a cushion material excellent in the above properties can be obtained. The present inventor has completed the present invention as a result of further studies based on such findings.

That is, according to the present invention, the melting point is 200.
In a composite fiber comprising a polyester component having a melting point of 200 ° C. or higher and a polyether ester block copolymer component having a melting point of 200 ° C. or lower, the polyether ester block copolymer has 40% terephthalic acid based on the total acid component (A). ~ 9
0 mol%, an acid component containing 10 to 40 mol% of isophthalic acid, (B) a glycol component mainly containing 1,4-butanediol, and (C) a poly (alkylene oxide) glycol component having an average molecular weight of 1000 to 4000. And the above (C) in the polyether ester block copolymer
The copolymerization amount of the components is 40 to 55% by weight and satisfies the following formula (i), and the intrinsic viscosity (IV), melting point (Tm) and oxidative decomposition starting temperature (Tdi) of the polyetherester block copolymer are satisfied. Satisfy the formulas (ii) to (iv), and (i) 60-Wc ≦ A _I (ii) 1.0 ≦ IV (iii) 160 ≦ Tm ≦ 200 (iv) 200 ≦ Tdi [where Wc is ( C) a copolymer of the component (wt%), a _I
Represents the copolymerization ratio (mol%) of the isophthalic acid component to the total acid component] and the polyester-based thermal bonding is characterized in that the polyether ester block copolymer component occupies 40% or more in the fiber cross-section peripheral ratio. Composite fibers are provided.

The polyester used for one of the conjugate fibers of the present invention is not particularly limited as long as it has a melting point of 200 ° C. or more and has a fiber-forming property. Among them, polyethylene terephthalate, polybutylene terephthalate, Alternatively, a copolyester obtained by copolymerizing a small amount of the third component with these is preferable.

The copolymerization component preferably used is
For example, dicarboxylic acid components such as isophthalic acid, adipic acid, sebacic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid, propylene glycol, diethylene glycol, neopentyl glycol, polyethylene glycol, p-xylylene glycol , 1,4-cyclohexanedimethanol, diol components such as 5-sodium sulforesorcin, polyfunctional carboxylic acid components such as trimellitic acid and pyromellitic acid, p
Examples thereof include bifunctional monocarboxylic acids such as oxybenzoic acid and p-oxyethoxybenzoic acid.

The polyether ester block copolymer, which is another component of the conjugate fiber of the present invention, has a copolymerization ratio (expressed in mol% based on the total acid component) of all the acid components of the copolymer. 40 to terephthalic acid as
Those containing 90 mol% and 10 to 40 mol% of isophthalic acid are used. Acid components other than terephthalic acid and isophthalic acid include phthalic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, 2,6-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid and 1,4-cyclohexanedicarboxylic acid. Is preferably used.

The polyether ester block copolymer used in the present invention contains 1,4-butanediol as a main glycol component. The term "mainly" used herein means that 80 mol% or more of all glycol components is 1,4.
-Butanediol means that other type glycol component may be copolymerized within the range of 20 mol% or less. The copolymer glycol component preferably used, ethylene glycol, trimethylene glycol,
Examples thereof include 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and the like.

Further, the polyether ester block copolymer used in the present invention has an average molecular weight of 1,000 to 4
It contains 40 to 55% by weight of 000 poly (alkylene oxide) glycol components. Average molecular weight is 100
When it is less than 0, the block property of the obtained block copolymer is deteriorated and the elastic recovery performance becomes insufficient.
If it exceeds 000, poly (alkylene oxide)
It is not preferable because the copolymerizability of the glycol component decreases and the elastic recovery performance becomes insufficient. Further, when the copolymerization amount is less than 40% by weight, even if the composite fiber is heat-bonded and molded into a cushioning material or the like, the desired elastic property of the present invention cannot be obtained. If it exceeds 55% by weight, mechanical properties and durability such as heat resistance and light resistance of the block copolymer are deteriorated, which is not preferable.

Poly (alkylene oxide) glycols preferably used include polyethylene glycol,
Examples thereof include poly (propylene oxide) glycol and poly (tetramethylene oxide) glycol, and poly (tetramethylene oxide) glycol homopolymers are particularly preferable. Furthermore, a random copolymer or a block copolymer in which two or more kinds of repeating carriers constituting the homopolymer are randomly or block-copolymerized may be used, and the homopolymer or the copolymer may be used. You may use the mixed polymer in which 2 or more types of these were mixed.

The polyetherester block copolymer used in the composite fiber of the present invention is required to satisfy the above compositional conditions, but according to the study by the present inventor, it further satisfies the following formula (i). I have found that it is important. (I) 60−Wc ≦ A _I [where Wc represents the copolymerization amount of the C component (% by weight), and A _I represents the copolymerization ratio (mol%) of the isophthalic acid component). ] Since the conjugate fiber of the present invention is usually heat-bonded in air,
When the copolymerization ratio of the C component is large, there is a problem that the mechanical properties of the non-woven fabric, cushioning material and the like, which are easily oxidatively deteriorated in the copolymer, are deteriorated, while the copolymerization amount of the C component is small. In this case, there is a problem that the elastic performance is insufficient and the object of the present invention cannot be achieved. However, in the present invention, it has been found that by satisfying the expression (i) for the copolymerization amount of isophthalic acid, it is possible to suppress oxidative deterioration in air while maintaining the elastic performance at a high level.

Next, the polyetherester block copolymer used in the conjugate fiber of the present invention has quality such as process stability during production of the conjugate fiber, thermal adhesion of the conjugate fiber, and elastic properties of the adhesive-treated product. In order to ensure the above, it is also important that the intrinsic viscosity IV, the melting point Tm, and the oxidative decomposition initiation temperature of the copolymer are within appropriate ranges.

That is, it is necessary to satisfy the following expressions (ii) to (iv). (Ii) 1.0 ≦ IV (iii) 160 ≦ Tm ≦ 200 (iv) 200 ≦ Tdi where IV is the intrinsic viscosity measured with a 35 ° C. orthochlorophenol solution, and Tm is the differential scanning calorimeter (DS).
C) is the melting point, and Tdi is the oxidative decomposition initiation temperature measured by DSC in an air atmosphere.

When the IV is less than 1.0, it is presumed that it is due to the broad molecular weight distribution of the polyetherester block copolymer, but the molecular weight reduction due to thermal decomposition of the copolymer. It is not preferable because the mechanical properties and elastic performance of the obtained non-woven fabric, cushioning material, and other adhesive-treated products are greatly reduced.

If the melting point exceeds 200 ° C.,
The heat treatment temperature when manufacturing non-woven fabrics and cushion materials is 2
The temperature must be set to 00 ° C. or higher, and during this heat treatment, thermal decomposition of the block copolymer occurs, resulting in deterioration of mechanical properties and elastic performance of the adhesive-treated product obtained. On the other hand, when the melting point is less than 160 ° C., the oxidation resistance of the polyether ester block copolymer is generally inferior in the molten state, and therefore, 180 ° C. which is usually used for the adhesion treatment.
It is difficult to obtain a product having desired elastic performance and mechanical properties because it undergoes oxidative decomposition even at a moderate heat treatment temperature. Although it is possible to lower the heat treatment temperature to prevent this, it is presumed that the melt viscosity of the copolymer is increased when it is used in a mixture with other fiber types, and the adhesiveness is lowered, resulting in the Not only the purpose is not achieved, but also the heat resistance of the obtained product is insufficient, which is not preferable.

Further, the oxidative decomposition starting temperature must be 200 ° C. or higher. If the temperature is lower than 200 ° C., the polyether ester block copolymer should be used in the heat-bonding treatment in air as described above. Oxidative deterioration of the polymer makes it impossible to obtain the intended adhesively treated product.

In order to increase the oxidative decomposition initiation temperature, the copolymerization amount of poly (alkylene oxide) glycol is decreased, the copolymerization ratio of acid components other than terephthalic acid such as isophthalic acid is decreased, and the melting point is increased. , Poly (alkylene oxide) glycol with high resistance to oxidative deterioration,
For example, it is possible to use polytetramethylene glycol or to use an antioxidant together. However, if only one method is adopted, the elastic performance is deteriorated and the effect of improving the oxidative decomposition start temperature is insufficient. To do. However, by appropriately combining the above measures within a range that satisfies the above-mentioned polymer composition, the oxidative decomposition start temperature can be set to 200 ° C. or higher while maintaining the elastic recovery performance.

The polyether ester block copolymer described in detail above can be produced by a conventionally known method for producing a copolyester. Specifically, a terephthalic acid component, an isophthalic acid component, and a dicarboxylic acid component other than these, a glycol component mainly containing 1,4-butanediol, and a poly (alkylene oxide) glycol are put in a reactor, and a catalyst Transesterification reaction or esterification reaction in the presence or absence, then polycondensation reaction in the presence of a catalyst under high vacuum,
This is a method of raising the polymerization degree to a desired level. At this time, it is preferable to add an antioxidant (for example, a hindered phenol compound, a hindered amine compound, etc.) if necessary.

In the present invention, such a polyetherester block copolymer includes a matting agent, a pigment (for example, carbon black, etc.), an ultraviolet absorber (for example, a benzophenone-based compound, etc.), as in ordinary polyesters.
It does not matter even if it contains a benzotriazole compound, a sacylate compound, etc.), a crosslinking agent (isocyanate compound, etc.) and the like.

The polyester-based thermoadhesive conjugate fiber of the present invention is a composite spinning of the above-described polyester component having a melting point of 200 ° C. or higher and a polyether ester block copolymer component of 200 ° C. or lower. in this case,
The composite ratio is not particularly limited, but the ratio of the block copolymer component to the total perimeter of the cross section of the composite fiber, that is, the fiber cross section peripheral ratio is preferably 40% or more, for example, side-by-side bimetal type, core-sheath type. Alternatively, an eccentric core-sheath type composite fiber in which it is eccentric can be exemplified. Among them, the eccentric core-sheath type composite fiber is preferable because the crimpability can be easily developed by heat treatment or the like, and thus the passability in the card process is improved.

Furthermore, the thermoadhesive conjugate fiber of the present invention comprises
It is preferable that the fiber is drawn 1.5 times or more. The cushion material formed by the stretched fibers has higher elasticity and lesser fatigue than the cushion material using the unstretched fibers. The reason for this is not clear, but during the process in which the stretched fiber is heat-treated in a relaxed state, relaxation of the amorphous portion of the block copolymer component occurs, resulting in a polymer structure with more excellent elastic properties. It is presumed that it is maintained even after being molded into a cushion material or the like.

The composite fiber of the present invention preferably has a low shrinkage ratio, and is preferably heat-set. That is, when the shrinkage rate is high, the shrinkage is remarkably contracted during the heat-bonding process, the heat-bonding efficiency between the fibers is lowered, and the repulsion property of the obtained cushioning material is lowered, and also the texture becomes extremely hard.

The composite fiber of the present invention may be a fiber aggregate such as a non-woven fabric or a cushioning material alone, or may be a mixture aggregate with another fiber containing 20% by weight or more of the conjugate fiber. Among them, when a fiber made of polyester such as polyethylene terephthalate or polybutylene terephthalate is used as the mixed fiber, not only the composite fibers of the present invention but also the thermal adhesion between the mixed fiber and the composite fiber is good. Therefore, it is possible to obtain a fiber assembly such as a cushion material having excellent mechanical properties and elastic properties.

In order to heat-treat and fuse and integrate the fiber assembly containing the conjugate fiber of the present invention, it is about 20 to 40 ° C. higher than the melting point of the block copolymer to form the conjugate fiber. The treatment may be performed at a temperature lower than the melting points of the polyester component and other fibers mixed in the fiber assembly.
If this processing temperature is too low, it will not be possible for the molten polymer to flow and bond well to the entangled parts, and the number of fibers that are entangled by heat fusion will be reduced and the resilience of the fiber aggregate of the cushioning material will decrease. descend. On the other hand, if the processing temperature is too high, the block copolymer is deteriorated due to heat, resulting in poor elasticity and marked discoloration.

[0028]

INDUSTRIAL APPLICABILITY In the fiber assembly comprising the polyester-based heat-adhesive conjugate fiber of the present invention, the fibers are heat-sealed by heating, and the fusion point is a polyetherester block co-polymer having a specific performance. Since it is formed from a united body, there is no deterioration of properties such as elastic performance and mechanical performance in the bonding process, and the strength and elastic properties of the fiber assembly (deformation recovery)
And the like are extremely excellent. Especially, when it is mixed with ordinary polyester short fibers to form a cushioning material, it has less initial hardness in compression than conventional foamed urethane foam, has a large resilience, and increases in proportion to the amount of compression. As a result, it is possible to obtain a product having excellent properties such that the feeling of bottoming is extremely small, and the density is low and the air permeability is good, so that there is no fear of getting stuffy. Also, because the adhesiveness between fibers is good, it has the characteristics that the bonded part during deformation is less likely to be broken, and that it is easily deformed but has good recoverability. Its durability against repeated compression is the durability of urethane. That's right.

In producing these fiber aggregates, a uniform product can be easily obtained by a simple and short process of heat treatment after forming a web. Moreover, the hardness can be arbitrarily changed in both the thickness direction and the plane direction by changing the mixing ratio of fibers, the constitution, or the density of the fiber aggregate.

Therefore, the cushioning material using the composite fiber of the present invention is excellent in cushioning property, durability and stability, has high breathability, is resistant to stuffiness, is less likely to cause uneven processing, and is diversified in processing. Easy cushion material,
The range of use thereof is suitable for various cushion materials such as furniture, beds, bedding, and cushions for seats.

[0031]

EXAMPLES The present invention will be specifically described with reference to the following examples. In the examples, all "parts" indicate parts by weight. In addition,
The evaluation in the examples was measured by the following method.

1. Intrinsic viscosity (IV) It measured at 35 degreeC using the ortho chlorophenol solvent.

2. Melting point (Tm) Using a differential scanning calorimeter 1090 type manufactured by Du Pont, measurement was performed at a temperature rising rate of 20 ° C./min to obtain a melting peak temperature.

3. Oxidative decomposition start temperature (Tdi) Using a differential scanning calorimeter 1090 type manufactured by Du Pont, measurement was carried out at an air flow rate of 90 ml / min and a heating rate of 20 ° C./min to obtain the oxidative decomposition start temperature.

4. Measurement of cushioning material's compression resilience and compression durability Density 0.035 g / cm ³ molded into a flat plate,
The cushion material with a thickness of 5 cm is compressed by 1 cm with a cylindrical rod having a flat bottom surface with a cross-sectional area of 20 cm ² and the stress (initial stress)
Was measured. After the measurement, the sample was compressed with a load of 800 g / cm ² for 10 seconds, then de-loaded and left standing for 5 seconds to repeat 360 times of compression and standing, and after 24 hours, the compressive stress was measured again. The ratio% of the stress after repeated compression to the initial stress was defined as the compression durability of the cushion material.

[0036]

Examples 1 to 3 and Comparative Examples 1 to 6 117.1 parts of dimethyl terephthalate, dimethyl isophthalate in the amounts shown in Table 1, 1,4-butadiol (1.4 mole times the acid component), Table 1 The described polytetramethylene glycol,
And tetrabutyl titanate (0.09 for acid component)
(0 mol%) was charged into the reactor, and the transesterification reaction was performed at an internal temperature of 190 ° C. After about 80% of the theoretical amount of methanol had been distilled, the polycondensation reaction was started by raising the temperature and reducing the pressure.
The polycondensation reaction is carried out while gradually reducing the pressure, and after reaching a vacuum of 1 mmHg or less, the reaction is carried out at 240 ° C. for 200 minutes, and then the antioxidant Irganox 1010 is added in an amount of 5% by weight based on polytetramethylene glycol. , The reaction was completed.

After pelletizing the produced polyetherester block copolymer, the polyetherester block copolymer is used as a sheath, polyethylene terephthalate is used as a core, and the weight ratio of core / sheath is 50/50. It was spun by a conventional method. The conjugate fiber is an eccentric core-sheath type conjugate fiber. This fiber was drawn 2.0 times, cut into 64 mm, and then heat-treated with warm water at 95 ° C. to reduce shrinkage and develop crimp, and dried, and then an oil agent was applied. The single yarn fineness of the composite short fibers obtained here is 6 denier.

This polyetherester block copolymerization
40% of composite short fibers containing body and single yarn obtained by a conventional method
Hollow-section polyethylene with a fineness of 6 denier and a fiber length of 64 mm
Mix 60% terephthalate short fiber with a card and
Web (web bulk 120 cm ³/ G) was obtained. This way
Thickness, 5 cm, density 0.035 g / cm³Will be
Put in a flat mold and heat treat at 200 ℃ for 10 minutes.
A flat cushion material was obtained. Of the obtained cushion material
The characteristics are shown in Table 1.

[0039]

[Table 1]

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Claims (1)

[Claims] 1. A composite fiber comprising a polyester component having a melting point of 200 ° C. or higher and a polyether ester block copolymer component having a melting point of 200 ° C. or lower, wherein the polyether ester block copolymer is (A) total acid. An acid component containing 40 to 90 mol% of terephthalic acid and 10 to 40 mol% of isophthalic acid, (B) a glycol component mainly containing 1,4-butanediol, and (C) an average molecular weight of 1,000 to 4000 poly (alkylene oxide)
It is composed of a glycol component, and the copolymerization amount of the component (C) in the polyether ester block copolymer is 40 to 5
5% by weight and satisfying the following formula (i), the intrinsic viscosity of the polyether ester block copolymer (I
V), melting point (Tm) and oxidative decomposition initiation temperature (Tdi) satisfy the formulas (ii) to (iv), and (i) 60-Wc ≦ A _I (ii) 1.0 ≦ IV (iii) 160 ≦ Tm ≤ 200 (iv) 200 ≤ Tdi [where Wc is the copolymerization amount (% by weight) of the component (C), A _I
Represents the copolymerization ratio (mol%) of the isophthalic acid component to the total acid component] and the polyester-based thermal bonding is characterized in that the polyether ester block copolymer component occupies 40% or more in the fiber cross-section ratio. Composite fiber.