JPH07258921A - Polyester-based binder fiber - Google Patents

Abstract

PURPOSE:To obtain a polyester-based binder fiber having excellent adhesiveness and being inexpensively produced in good operation efficiency. CONSTITUTION:This binder fiber comprises a polyalkylene terephthalate A and a polyester B in which the polyester B comprises at least a part of the surface of the fiber. The polyester B is a copolyester which is composed of an aromatic dicarboxylic acid component containing >=10mol% phthalic acid component and a glycol component constituted of 98-70mol% ethylene glycol and 2-30mol% diethylene glycol in which the total amount of the phthalic acid component and diethylene glycol is 8-55mol% based on the whole components of the polyester. The copolyester has >=0.35 intrinsic viscosity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot-melt type polyester binder fiber having excellent adhesiveness.

[0002]

2. Description of the Related Art In recent years, hot-melt type binder fibers have been widely used for the purpose of adhering fibers (main fibers) constituting pillow, bedding padding, quilting padding, mattress padding and the like. As such a binder fiber, a core-sheath type polyolefin fiber having polyethylene as a sheath and polypropylene as a core (Japanese Patent Application Laid-Open No. Sho 58-180614).
No. 58-191215, etc.) and a low softening point copolyester, a polyester fiber having a low softening point copolyester as a sheath and a high softening point polyester as a core, and a polyester fiber structure bonded using the same. Some products have been proposed (US Pat. No. 4,129,675, JP-A-57-66117, etc.).

Polyolefin-based binder fibers are preferable when the main fibers to be adhered are polyolefin fibers, but when the main fibers to be adhered are polyester fibers which have been widely used in recent years, they are incompatible with each other. Since it is a solution system, the adhesive effect is poor, and since a large amount of binder fiber must be used, there is a problem in that the characteristics of the main fiber of interest are impaired.

Currently, polyester binder fibers are
Adhesives containing terephthalic acid, isophthalic acid, and copolyesters containing ethylene glycol as the main component are widely used, but the flowability during melting is poor and the adhesive strength may be insufficient. It was necessary to use a large amount in order to obtain good adhesive strength. Further, in order to manufacture at a lower cost, it is necessary to reduce the amount of copolyester used or to use a raw material supplied at a lower cost.

[0005]

DISCLOSURE OF THE INVENTION The present invention is suitable for adhering a fiber structure having a polyester fiber as a main fiber,
In addition, it is intended to provide a polyester binder fiber having excellent adhesiveness, good operability, and inexpensively produced.

[0006]

Means for Solving the Problems As a result of various studies for solving the above-mentioned problems, the present inventors have decided to use a copolyester having a specific copolymer composition as a composite binder fiber having an adhesive component. Found that
The present invention has been reached.

That is, the gist of the present invention is as follows. A polyester binder fiber comprising a polyalkylene terephthalate A and the following polyester B, wherein the polyester B occupies at least a part of the fiber surface. Polyester B Comprised of an aromatic dicarboxylic acid component containing 10 mol% or more of a phthalic acid component and a glycol component composed of 98 to 70 mol% of ethylene glycol and 2 to 30 mol% of diethylene glycol, and the total amount of the phthalic acid component and diethylene glycol is A copolyester having an intrinsic viscosity of 0.35 or more, which accounts for 8 to 55 mol% of all components constituting the polyester.

The present invention will be described in detail below. The polyalkylene terephthalate A used in the present invention has a melting point of 220 ° C. or higher. Specific examples thereof include polyethylene terephthalate and polybutylene terephthalate, with polyethylene terephthalate being preferred from the viewpoint of strength characteristics.

Polyester B is composed of an aromatic dicarboxylic acid component containing 10 mol% or more of a phthalic acid component and a glycol component consisting of 98 to 70 mol% of ethylene glycol and 2 to 30 mol% of diethylene glycol.

Aromatic dicarboxylic acid components other than phthalic acid components include terephthalic acid, naphthalene dicarboxylic acid,
Although isophthalic acid and the like can be used, terephthalic acid and isophthalic acid are preferable from the economical viewpoint. The proportion of the phthalic acid component in the acid component of the polyester B must be 10 mol% or more, preferably 15 to 50 mol%. If the proportion of the phthalic acid component is less than 10 mol%, the heat treatment temperature at the time of bonding must be extremely high, the main fibers will be softened and the crimp will be impaired, and the strength and bulkiness of the product will decrease. Not preferable.

The glycol component of the polyester B is composed of ethylene glycol and diethylene glycol, but the proportion of diethylene glycol needs to be 2 to 30 mol%, preferably 5 to 20 mol%. . If the proportion of diethylene glycol is less than 2 mol%, the copolyester may have poor fluidity and the adhesive strength may be insufficient, which is not preferable. Further, if the proportion of the diethylene glycol component exceeds 30 mol%, it is difficult to increase the degree of polymerization, and the heat resistance and weather resistance of the copolyester deteriorate, which is not preferable.

Furthermore, in the polyester B, it is necessary that the total amount of the phthalic acid component and diethylene glycol accounts for 8 to 55 mol% of all the components constituting the polyester. When this ratio is less than 8 mol%,
Since the softening temperature exceeds 200 ° C and the heat treatment temperature at the time of bonding must be extremely high, the main fibers are softened and the crimps are impaired, so the strength and bulkiness of the obtained product are reduced,
Not preferable. On the other hand, if this ratio exceeds 55 mol%,
The softening temperature is lower than 80 ° C, the spinning condition is deteriorated, and the glass transition temperature is lowered, which causes operational problems such as blocking when storing chips and tacking of fibers after spinning. , Not preferable.

Polyester B has an intrinsic viscosity of 0.35
It is necessary that it is at least 0.50, preferably at least 0.50. If the intrinsic viscosity is less than 0.35, the spinnability is poor, especially in the case of composite spinning, which is not preferable.

Polyester B contains other components, such as oxalic acid, adipic acid, sebacic acid, azelaic acid, and decanedicarboxylic acid, and other aliphatic dicarboxylic acids, p-hydroxybenzoic acid, etc., as long as the characteristics of polyester B are not significantly changed. Aromatic hydroxycarboxylic acid, triethylene glycol,
A small amount of a diol such as polyethylene glycol, propanediol, butanediol, pentanediol, hydroquinone or bisphenol A may be contained as a copolymerization component, and a stabilizer and other additives may be contained.

The polyester B can be obtained, for example, as follows. First, an esterification reaction product obtained from phthalic acid (or phthalic anhydride) and ethylene glycol, an esterification reaction product obtained from terephthalic acid and ethylene glycol under esterification reaction conditions under nitrogen gas suppression at a predetermined temperature. Then, a predetermined amount of diethylene glycol is transferred to a polymerization reaction vessel, and a polycondensation reaction is carried out by a conventional method until a copolyester having a predetermined intrinsic viscosity is obtained. The polycondensation reaction is usually carried out in the presence of a polycondensation catalyst, and conventionally used metal compounds such as antimony, germanium, tin, titanium and cobalt are used.

The fiber of the present invention only needs to have at least a part of the fiber surface formed of polyester B, and the form thereof is a conjugate fiber such as a joint type, a core-sheath type, a sea-island type or a multi-layer joint type. A part or all of the components occupying the surface may be formed of polyester B. In particular, the core-sheath type is preferable because of good spinnability.

The composite ratio is preferably 20 to 80% by weight of polyester B. 20 polyester B
If less than 80% by weight, sufficient adhesion cannot be obtained, and 80% by weight
If it exceeds, the spinnability is deteriorated and the strength of the fiber is reduced, which is not preferable.

The binder fiber of the present invention can be produced by compounding polyester A and polyester B, melt-spinning by a conventional method, stretching, and cutting if necessary.

The binder fiber of the present invention is mixed with other fibers as short fibers, passed through a card to make a web, and heat-treated to give a non-woven fabric or a filling. Further, ordinary polyester long fibers may be mixed with the binder fiber of the present invention to form short fibers, and then the web may be formed.

[0020]

The binder fiber of the present invention is excellent because it has a low softening temperature and good fluidity during softening because it uses a specific copolyester in which a phthalic acid component and diethylene glycol are copolymerized as an adhesive component. It is presumed that it shows adhesiveness.

[0021]

EXAMPLES Next, the present invention will be described in detail with reference to examples. In addition, the measuring method of the characteristic value in an Example is as follows. (1) Intrinsic viscosity ([η]) An equal weight mixture of phenol and ethane tetrachloride was used as a solvent, and the temperature was measured at 20 ° C. (2) Softening temperature (Sp) Using the melting point measuring device AMP-1 manufactured by Yanagi Head Office, the heating rate was 10
The softening temperature was determined by determining the penetration temperature in the silicone bath at ° C / min. (3) Nonwoven fabric strength Using a constant speed extension type tensile tester UTM-4-100 made by Orientec Co., using a sample with a width of 25 mm, a sample length of 100 mm and a temperature of 25
It was measured at a temperature of 100 ° C. and a pulling speed of 100 mm / min. (4) Glass transition temperature (Tg), crystallization temperature (Tc) and melting point (Tm) Using a differential scanning calorimeter DSC-2 type manufactured by Perkin Elmer Co.,
It was measured at a temperature rising rate of 20 ° C./min.

Example 1 A slurry of phthalic acid (PA) and ethylene glycol (EG) was placed in an esterification reaction can equipped with a stirrer and a packed tower, and the temperature was 200 ° C. and the packed tower temperature while stirring under normal pressure.
The esterification reaction was carried out for 5 hours under the condition of 130 ° C. while removing the by-product water out of the reaction system to obtain an esterified product with a reaction rate of 95%. Further, a slurry of terephthalic acid (TPA) and EG is continuously supplied to an esterification reaction vessel containing bis (β-hydroxyethyl) terephthalate and its low polymer, and the temperature is 250 ° C and the pressure is 0.05 kg / cm ² The reaction was carried out under the conditions of G and a residence time of 8 hours to continuously obtain an esterified product with a reaction rate of 95%. The esterified product was transferred to the polycondensation reactor at the molar ratio shown in Table 1, and diethylene glycol (DEG) having the molar ratio shown in Table 1 and antimony trioxide as a polycondensation catalyst were added at 2 × 10 ^-4 mol / acid component. Mol and was added and the temperature of the reactor was raised to 280 ° C. in 30 minutes and the pressure in the reactor was gradually reduced to less than 0.1 torr after 60 minutes. The polycondensation reaction was carried out for 3 hours with stirring under these conditions to obtain a copolyester having the characteristic values shown in Table 1. This copolyester and [η] 0.68, polyethylene terephthalate having a Tm of 256 ° C. were used with a concentric core-sheath type composite melt spinning device and a spinning spinneret with 225 discharge holes to produce a spinning temperature of 270 ° C.
With a discharge rate of 250 g / min and a composite weight ratio of 1: 1, melt spinning was carried out so that the former became a sheath, and after cooling, it was wound at a speed of 800 m / min to obtain a composite undrawn yarn. This unstretched yarn was bundled into a 100,000 denier tow, stretched at a stretching temperature of 45 ° C and a draw ratio of 3.2, crimped with a push-in crimper, and then length 51 mm.
It was cut into pieces to obtain a binder fiber having a fineness of 4 denier.
30 parts by weight of this binder fiber and 70 parts by weight of polyethylene terephthalate fiber having a length of 51 mm and a fineness of 2 denier were mixed and passed through a card to make a web having a basis weight of 50 g / m ² at 200 ° C.
Heat treatment was carried out for 2 minutes on the rotary dryer. The tensile strength of the resulting nonwoven fabric is shown in Table 1.

Examples 2 to 9 and Comparative Examples 1 to 4 Example 1 was repeated except that the molar ratio of PA / TPA / EG / DEG was as shown in Table 1. The results are shown in Table 1. In Comparative Example 1, the chips were partially blocked when the chips were stored, or the fibers after spinning were partially tacked, so that a sufficient product amount could not be obtained. In Comparative Example 2, the polycondensation reaction was carried out for 1 hour and then discharged, but the spinnability was poor, probably because the intrinsic viscosity was low and the fluidity was too high, and a sufficient product amount could not be obtained.

Example 10 Example 10 was repeated except that phthalic anhydride was used instead of PA. The results are shown in Table 1.

Example 11 Example 11 was repeated except that polybutylene terephthalate was used as the core component instead of polyethylene terephthalate. The results are shown in Table 1.

Example 12 The same procedure as in Example 1 was carried out except that the composite spinning form was changed to the joint type instead of the concentric core-sheath type. The results are shown in Table 1.

Example 13 An esterified product obtained in the same manner from an esterified product, isophthalic acid (IPA) and EG was charged in a polycondensation reactor so that the molar ratio of TPA to IPA was 50/50. The same procedure as in Example 1 was performed. The results are shown in Table 1.

Example 14 Example 1 was repeated except that the esterified product obtained from the esterified product, IPA and EG in the same manner was charged into the polycondensation reactor so that the molar ratio of TPA to IPA was 67/33. I went the same way. The results are shown in Table 1.

[0029]

[Table 1]

[0030]

According to the present invention, a copolyester having a low softening point and a good fluidity at the time of softening is used as an adhesive component, so that the main fibers can be quickly and effectively bonded at a low heat treatment temperature. You can In addition, this copolyester is relatively inexpensive and does not block when storing chips, or the fiber after spinning does not tack, so by using this copolyester as an adhesive component, operability is improved. The binder fiber can be manufactured well and at low cost. The binder fiber of the present invention is particularly suitable for bonding a fiber structure containing a polyester fiber having a high softening temperature such as polyethylene terephthalate as a main fiber.

Claims (1)

[Claims] 1. A polyester binder fiber comprising a polyalkylene terephthalate A and the following polyester B, the polyester B occupying at least a part of the fiber surface. Polyester B Comprised of an aromatic dicarboxylic acid component containing 10 mol% or more of a phthalic acid component and a glycol component composed of 98 to 70 mol% of ethylene glycol and 2 to 30 mol% of diethylene glycol, and the total amount of the phthalic acid component and diethylene glycol is A copolyester having an intrinsic viscosity of 0.35 or more, which accounts for 8 to 55 mol% of all components constituting the polyester.