JPH0754253A - Polyester solid fiber for cushioning material - Google Patents

Abstract

PURPOSE:To obtain polyester solid fibers useful for cushioning materials, etc., hardly weakening even by repeated compression and under a high-temperature atmosphere. CONSTITUTION:This polyester solid fibers are obtained by bonding polyester fibers comprising or consisting essentially of a poly(bismethylene cyclohexane terephthalate), having >=80 deg.C glass transition point and >=150 deg.C melting point, with a copolyester-based thermally bondable fibers having >=80 deg.C melting point and has >=5mm thickness and 0.01g/cm<3> density.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester cotton wool which can be a cushioning material which does not easily become set when used for a long period of time or in a high temperature atmosphere.

[0002]

2. Description of the Related Art Conventionally, polyurethane foam has been mainly used as a cushioning material for furniture, such as softeners, chair backs, cushions, beds, and automobile seats. However, polyurethane foam
Problems have been pointed out from the standpoint of safety and environmental protection, such as the generation of nitrogen-containing toxic gases during combustion, and the fact that CFCs used during production destroy the ozone layer above the atmosphere.

Therefore, it is conceivable to use a cushioning material mainly composed of polyester fibers as a material replacing the polyurethane foam. A polyester fiber web is needling-processed or a binder fiber is fusion-bonded together ( For example, there is JP-A-57-35047).

[0004]

Among conventional polyester cushioning materials, those obtained by needling a polyester fiber web tend to cause some of the fibers to fall off or scatter, which is an attempt to prevent this drawback. A material obtained by fusion-bonding with binder fiber is also easily set against repeated compression or compression in a high temperature atmosphere, and the defect that the cushioning property is deteriorated over time has not been solved.

The present invention solves the above-mentioned settling of conventional polyester cushion materials, and is also used in the fields of cottages and beds for furniture, cushion materials for automobile seats, cushions, cushions, mats and the like. It is an object of the present invention to provide a novel solid cotton for polyester cushion material, which is hard to sag even in a high temperature atmosphere.

[0006]

The inventor of the present invention has reached the present invention as a result of earnest studies for developing such a novel cushion material. That is, according to the present invention, polyester fibers having a glass transition temperature of 80 ° C. or higher and a melting point of 150 ° C. or higher, which contains the bismethylenecyclohexane terephthalate unit itself or a main component thereof, are point-bonded by a heat fusion fiber. The present invention provides a polyester cotton wool for cushion material having a thickness of 5 mm or more and a density of 0.015 g / cm ³ or more.

Next, the present invention will be described in detail. In order to obtain the objectionable polyester cushion material of the present invention, it is necessary that the polyester, which is the material of the constituent fibers, has a glass transition temperature of 80 ° C. or higher and a melting point of 150 ° C. or higher.

When the glass transition temperature is lower than 80 ° C., the cushion material is liable to be fragile when subjected to a load in a high temperature atmosphere, which is not preferable for the purpose of the present invention. The cushion material made of the polyester fiber of the present invention has a glass transition temperature of polyethylene terephthalate (about 70) which is the glass transition temperature of the polyester constituting the cushion material.
C.), it is hard to be permanently deformed even when subjected to a load in a high temperature atmosphere, and is unlikely to cause fatigue.

If the melting point is less than 150 ° C., the polymer has a low crystallinity, so that the heat resistance is insufficient, and it is difficult to heat-set during fiber production. For example, volume shrinkage occurs during cotton wool production. Fiber properties are unstable and not practical.

The polyester constituting the cushioning material of the present invention must be a polyester composed of the bismethylenecyclohexane terephthalate unit itself or a copolyester having this as a main constituent. In the case of the copolyester, 70 mol of the constituent is preferable. % Or more is a copolyester having a bismethylene cyclohexane terephthalate unit. Ordinary poly (bismethylenecyclohexane terephthalate) itself has a glass transition temperature of 130.
C., melting point 292.degree. C., which meets the object of the present invention.

In the copolyester of the present invention, if necessary, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, adipic acid, sebacic acid, bisphenol S, ethylene glycol, 1, 4 may be used as long as the object of the present invention is not impaired. -Butanediol, 1,6-hexanediol, diethylene glycol, polyethylene glycol, and other auxiliary materials may be copolymerized, and various additives may be contained.

[0012] When the copolymerization ratio of such a copolymer is too high, the amorphousness becomes high, the melting point is lowered, and the heat resistance is deteriorated. Therefore, the copolymerization ratio is preferably about 30 mol% or less. .

The constituent components of the monomers constituting the copolyester used in the present invention and the co-weight ratio thereof can be selected within a wide range, but in consideration of economical efficiency, versatility and physical properties, the following ones are preferable. . That is, it is a copolyester obtained by copolymerizing 70 to 95 mol% of a bismethylenecyclohexane terephthalate unit and 5 to 30 mol%, preferably 7 to 20 mol% of an ester unit of ethylene glycol and terephthalic acid.

Next, an example of the method for producing the polyester used in the present invention will be specifically described. Terephthalic acid and 1,4
-Bis (4-hydroxymethyl-cyclohexylmethyl) terephthalate and its oligomer obtained by the esterification reaction with cyclohexanedimethanol were transferred to a polymerization reaction vessel and heated at a temperature of 290-310 ° C for 0.5-5.
The polycondensation reaction is performed under reduced pressure of 1 Torr or less for an hour. After polycondensation until the desired intrinsic viscosity is achieved, the pressure is returned to normal pressure with nitrogen gas, the polyester is dispensed in a Tegus shape by pressurization, cooled, and then cut to obtain a chip-shaped polyester.

The polycondensation reaction is usually carried out in the presence of a catalyst, and as the polycondensation reaction catalyst, antimony, germanium, tin, which are generally used in the production of polyesters,
Compounds of metals such as titanium and cobalt, and organic sulfonic acid compounds of sulfosalicylic acid and o-sulfobenzoic anhydride are used. The polycondensation reaction catalyst may be added in advance in the esterification step.

The polyester fiber used in the cushion material of the present invention may be manufactured by the same method as that for general-purpose polyester fiber. Although the production conditions differ depending on the physical properties of the polyester used, they can generally follow conventional techniques. That is,
A general-purpose spinning device may be used for spinning. In addition, during spinning, a stabilizer, a fluorescent agent, a pigment, and a reinforcing material may coexist. The cross-sectional shape of the fiber is round, cross-section, flat, six-leaf,
It may be a W-shaped or triangular cross-section or a hollow cross section.

The spun fiber is cut into short fibers after stretching, heat treatment and crimping, if necessary, continuously or in a separate step. The fineness is not particularly limited and may be determined according to the required characteristics depending on the application, but generally 2 to 200
Denier ones are used.

The heat-fusible fiber which is another component of the polyester cotton wool of the present invention has a polymer having a melting point lower than that of the main polyester fiber as a binder component. As such a heat-bonding fiber, any fiber may be used as long as it is made of a polymer having a melting point of about 10 ° C. or more lower than that of the polyester fiber for the cushion material as a main component,
Olefin-based, polyamide-based, and polyester-based heat-sealing fibers such as polyethylene and polypropylene are preferable.
Among them, polyethylene terephthalate or polybutylene terephthalate is copolymerized with isophthalic acid, diethylene glycol, 1,6-hexanediol, ε-caprolactone, etc., and is a copolyester system having a melting point of 80 ° C. or higher, or polyethylene glycol, polytetramethylene glycol, etc. A polyester elastomer-based heat-sealing fiber having a melting point of 80 ° C. or higher is more preferable.

The heat-fusible fibers include monocomponent fibers consisting only of the above-mentioned polymer, and core-sheath type, side-by-side type, sea-island type, split type, in which the polymer forms all or part of the surface of the single fiber. Examples include composite fibers such as fibers. Among these, the core-sheath composite fiber in which the core is polyethylene terephthalate and the sheath is a copolyester or copolyester ether elastomer having a good melting point of 80 ° C. or more and having good crystallinity is more preferable from the viewpoints of non-fatigue and soft feeling. . The fineness of the heat fusion fiber is not limited, but is 2
-100 denier is suitable.

The polyester solid cotton of the present invention is prepared by mixing the polyester fibers for the cushioning material and the heat-sealing fibers, forming a web with a carding machine, etc., and then melting the heat-sealing component through a heat treatment device to form the web. It can be obtained by spot-bonding polyester fibers for lumber. In this case, the needling process may be performed before the heat treatment.

The proportion of the heat-sealing fibers used in the present invention is
It may be 10 to 70% of the whole cotton wool, but it can be changed depending on the required characteristics depending on the application. As the heat treatment apparatus, a hot air circulation dryer, a hot air once-through dryer, a saxion drum dryer, a Yankee drum dryer, or the like is used, and the treatment may be performed by selecting the treatment temperature and the treatment time according to the melting point of the heat-sealing fiber.

The polyester cotton of the present invention must have a thickness of 5 mm or more in order to maintain its cushioning property. The upper limit is not particularly limited, but about 150 mm is preferable from the viewpoint of manufacturing equipment, manufacturing cost, and ease of use. The density of the polyester cotton of the present invention is 0.015 g.
/ Cm ³ or more is required. Density is 0.015g / cm
If it is less than ^3, it tends to get tired by repeated compression,
Inappropriate. The upper limit of the density is not specified because it differs depending on the required degree of cushioning property depending on the application.
From the viewpoint of manufacturing cost and the like, it is preferably 0.1 g / cm ³ or less. In order to regulate the thickness and density of the polyester cotton wool of the present invention, while appropriately selecting the basis weight of the web before heat treatment in consideration of the area shrinkage of the web by heat treatment, or incorporating a thickness regulating roll in the heat treatment device, A web may be sandwiched between plates or wire mesh sandwiching a spacer having a predetermined thickness for heat treatment.

[0023]

[Function] The polyester solid cotton for cushion material of the present invention is
It is hard to get tired of repeated compression, and
Since this polyester has a glass transition temperature of 80 [deg.] C. or higher, it is hard to be depressed even when compressed in a high temperature atmosphere of, for example, 70 to 80 [deg.] C. and has very good cushioning property.

[0024]

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. The methods for evaluating various physical properties described in the present invention are as follows. (1) Intrinsic Viscosity Using an equal weight mixture of phenol and ethane tetrachloride as a solvent,
It was measured at a sample concentration of 0.5 g / decitritol and a temperature of 20 ° C. (2) Melting point A differential scanning calorimeter DSC-2 type manufactured by Perkin Elmer was used, and the melting point was measured at a temperature rising rate of 20 ° C./min. (3) Fineness: JIS L-1015 7 ・ 5.1
It was measured by the method A. (4) Strength and elongation: JIS L-1015 7.7
Was measured by the method.

(5) Settling resistance during repeated compression After measuring the thickness of the polyester cushion material, a test piece (10 cm × 10 cm) is sandwiched between parallel plane plates and a load of 15 kg is applied at 60 times per minute. Thickness was measured after a total of 50,000 repeated compression tests.
(%) Was calculated and used as a measure of fatigue resistance. The larger the value of C, the less likely it is to get tired.

(6) Settling resistance under high temperature atmosphere After measuring the thickness of the polyester cushion material, a test piece (10 cm x 10 cm) is sandwiched between parallel plane plates and compressed and fixed to 50% of the original thickness. And put it in a constant temperature bath at a temperature of 70 ° C.
After leaving it for 6 hours, it is taken out, removed from the plane-parallel plate and left for 30 minutes at room temperature, and its thickness is measured. The bulkiness retention rate Cp (%) under a high temperature atmosphere was calculated by the following formula and used as a measure of sag resistance.

Production Example 1 26 g of tetrabutyl titanate was added to 64.2 kg of bis (4-hydroxymethyl-cyclohexylmethyl) terephthalate and its oligomer obtained by the esterification reaction of 1,4-cyclohexanedimethanol and terephthalic acid. , Temperature 280 ℃, under nitrogen gas pressure control 3.6kg
The esterification reaction was carried out for 2 hours at / cm ² . The obtained esterified product was transferred to a polycondensation reactor and subjected to polycondensation reaction at a temperature of 305 ° C. and a pressure of 0.4 torr for 3 hours to obtain a polyester (A). The obtained polyester (A) had a glass transition temperature of 130 ° C., a melting point of 292 ° C. and an intrinsic viscosity of 0.71.

Production Example 2 Bis (4-hydroxymethyl-cyclohexylmethyl) terephthalate and its oligomer obtained by esterification reaction of 1,4-cyclohexanedimethanol and terephthalic acid, 64.2 kg, 4.3 kg terephthalic acid,
2.0 kg of ethylene glycol and 26 g of tetrabutyl titanate were added, and the temperature was 260 ° C. and nitrogen gas pressure was 3.6.
The esterification reaction was carried out at kg / cm ² for 2 hours. The obtained esterified product was transferred to a polycondensation reactor and subjected to polycondensation reaction at a temperature of 290 ° C. and a pressure of 0.4 torr for 3 hours to obtain a copolyester (B). The obtained copolyester (B) had a copolymerization amount of terephthalic acid units of 10 mol%, a glass transition temperature of 119 ° C., a melting point of 264 ° C., and an intrinsic viscosity of 0.72.

Production Example 3 Bis (β-hydroxyethyl terephthalate) obtained by the esterification reaction of terephthalic acid and ethylene glycol and its oligomer (45.0 kg) were added with 26 g of tetrabutyl titanate, and the temperature was 250 ° C. under nitrogen gas suppression. The esterification reaction was carried out for 2 hours at 3.6 kg / cm ² . The obtained esterified product was transferred to a polycondensation reactor, and the temperature was adjusted to 28
Polycondensation reaction was carried out at 0 ° C. and a pressure of 0.4 torr for 3 hours to obtain polyester (C). The obtained polyester (C, polyethylene terephthalate) has a glass transition temperature of 70.
C., melting point 255.degree. C., intrinsic viscosity 0.72.

Example 1 The polyester (A) obtained in Production Example was spun, stretched and crimped by a usual method for producing a hollow fiber, dried and heat-set at 170 ° C., and then cut to obtain a fineness of 6d and a fiber length. A short fiber having a yarn quality of 51 mm, a single yarn strength of 4.3 g / d and a single yarn elongation of 48% was obtained. Copolymerization of this short fiber with PET as a core component, terephthalic acid, and 1,4-butanediol / 1,6-hexanediol (molar ratio 68/32) as constituents and having good crystallinity and a melting point of 170 ° C. Polyester heat-sealing fiber (strength: 5.3 g / d, elongation: 52%, fineness: 2 denier, cutting length: 51 mm) having a core / sheath weight ratio of 50/50 with a polyester as a sheath component at a weight ratio of 80:20. Blended
After passing through a carding machine, stack with a cross-lapper and have a basis weight of 60
Needling was performed at a needle density of 240 needles / cm ² through a needle locker room having a barbed needle with a web of 0 g / m ² . Further, this web was put between wire nets having a spacer of 20 mm in thickness and heat-treated for 10 minutes in a hot air circulating dryer at 180 ° C. while controlling the thickness to obtain the solid of Example 1 having a thickness of 20 mm. Got cotton.
As a result of evaluating the cushioning property of this cotton, C = 95%, Cp
= 91%, and the sag resistance during repeated compression and in a high temperature atmosphere was also good.

Example 2 The procedure of Example 1 was repeated except that the copolyester (B) was used instead of the polyester (A), and the cushioning property was evaluated. The sag resistance in a high temperature atmosphere was good.

Examples 3 to 4 and Comparative Example 1 In Example 2, the amounts of terephthalic acid and ethylene glycol were changed to change the copolymerization rate of terephthalic acid to 20,
30 and 60% (the obtained polyesters are referred to as polyester (D): Example 3, polyester (E): Example 4 and polyester (F): Comparative example 1, respectively).
A cushion material was prepared in the same manner as in Example 1 except for the above, and the sag resistance during repeated compression and in a high temperature atmosphere was measured. The results are shown in Table 1. The results of Examples 3 and 4 were good, but the polyester used in Comparative Example 1 did not show a melting point peak in the differential scanning calorimeter, and therefore had insufficient heat resistance and was heat set in the short fiber manufacturing process. I couldn't. Perhaps because of this, the sag resistance in a high temperature atmosphere was insufficient.

Comparative Example 2 A cushion material was obtained in the same manner as in Example 1 except that the polyester (C) obtained in Production Example 3 was used. This cushion material had insufficient sag resistance during repeated compression and in a high temperature atmosphere. Table 1
The results of Examples 1 to 4 and Comparative Examples 1 and 2 are collectively shown in.

[0034]

[Table 1]

Examples 5 to 9 In Example 1, various kinds of dicarboxylic acid components and glycol components as shown in Table 1 were used as the type of polyester as the heat-sealing component of the sheath component of the polyester-based heat-sealing fiber. Cotton wool of Examples 5 to 9 was obtained in the same manner as in Example 1 except that the polyester was changed to the web heat treatment temperature shown in Table 2. Table 2 shows the evaluation results of the cushioning properties of Examples 5 to 9.

[0036]

[Table 2]

With regard to the cotton wool of Examples 5 to 9, the results of measuring the sag resistance during repeated compression and in a high temperature atmosphere were both good.

Examples 10 to 11 and Comparative Examples 3 to 4 In Example 5, the thickness of the spacer that regulates the thickness at the time of heat treatment is changed to 20 mm to be 7 mm, 35 mm and 55 mm (respectively Example 10, 11 and Comparative Example 3), and the weight of the web before heat treatment is changed from 600 g / m ² to 120 g / m ² and the thickness of the spacer that regulates the thickness during heat treatment is changed from 20 mm to 4 mm. Cotton wool of Examples 10 to 11 and Comparative Examples 3 to 4 was obtained in the same manner as in Example 5 except for (Comparative Example 4). Table 3 shows the evaluation results of the thickness, density, feel and sag resistance of the cotton wool of Examples 10 to 11 and Comparative Examples 3 to 4.

[0039]

[Table 3]

Although Examples 10 and 11 had a satisfactory feel and sag resistance as a cotton wool, Comparative Example 3 in which the density of the cotton wool was low was easy to sag. Further, in the case of Comparative Example 4 having an insufficient thickness, there is a feeling of flooring,
It was unsatisfactory as a cushion material.

[0041]

EFFECT OF THE INVENTION The polyester cotton wool of the present invention is resistant to sagging against repeated compression and compression in a high temperature atmosphere. Therefore, for example, when it is used as a cotton stuffing for cushions, it absorbs an impact and is comfortable to sit on forever. Further, since it does not easily sag over time and has a certain thickness or more, it has no floor feeling, and is suitable as a cotton pad or bed for furniture, a cushion material for automobile seats, and a mattress.

Claims (1)

[Claims] 1. A bismethylenecyclohexane terephthalate unit itself or a polyester fiber having a glass transition temperature of 80 ° C. or higher and a melting point of 150 ° C. or higher, which is a main constituent component thereof, is point-bonded by a heat-sealing fiber, Polyester cotton for cushion material having a thickness of 5 mm or more and a density of 0.015 g / cm ³ or more.