JPH0892468A - Polyester composition for binder fiber - Google Patents

Abstract

PURPOSE: To provide a polyester composition for use as binder fibers which has a low melting point and excellent crystallizability and can be efficiently granulated and formed into fibers. CONSTITUTION: This composition comprises a polyester, as the main component, consisting mainly of structural units represented by the formula (OC(CH2 )m CO-O (CH2 )n O (wherein (m) is an integer of 10 to 20 and (n) is an integer of 2 to 4) and having an intrinsic viscosity of 0.5 or higher and a swelling synthetic mica incorporated during the synthesis of the polyester in an amount of 0.01 to 5wt.% based on the composition. It has a melting point as measured with a differential scanning calorimeter of 80 to 120 deg.C, a difference between the melting point and the crystallization temp. during cooling of 20 deg.C or smaller, and a heat generation rate during crystallization upon cooling of 20ml/sec or higher.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester composition for a binder fiber which has a low melting point, exhibits excellent crystallinity, and has good operability during granulation and spinning.

[0002]

2. Description of the Related Art Recently, constituent fibers (main fibers) in roofing materials, automobile interior materials, non-woven fabrics used as carpet base cloths, and fiber structures such as pillows and mattresses.
Hot-melt type binder fibers have been widely used for the purpose of adhering each other.

Polyester fibers, which are relatively inexpensive and have excellent physical properties, are most often used as the main fiber, and the binder fiber for adhering them is also preferably of the polyester type. Have been proposed (for example, US Pat. No. 4,129,675 and many others).

By the way, for fiberizing binders,
Copolyesters with an adhesion temperature of 110-220 ° C are used. However, many of these copolyesters do not show a clear melting point. Of these, the polyester with the lowest adhesion temperature, 110 ° C, has a softening point of around 60 ° C and does not show a clear melting point peak (amorphous polyester). Therefore, during cutting during chip manufacturing or during chip drying, In addition, there is a problem that blocking occurs during transportation and tacking occurs during yarn making.

Recently, the use of binder fibers has been diversified, and there is a demand for a binder fiber having a lower practical bonding temperature than the conventional ones. In order to satisfy this demand, it has been studied to use a copolyester obtained by copolymerizing a long-chain aliphatic compound, but it has been extremely difficult to produce a binder fiber in terms of blocking and tacking.

Further, as a polyester binder fiber, in JP-A-63-6110, a linear aliphatic dicarboxylic acid component having 14 or more carbon atoms and a linear alkylene glycol component having 4 or more carbon atoms are used. Although what uses polyester as an adhesive component is disclosed, the heat generated during crystallization is small if this polyester is simply used.
There was a problem that fusion between single yarns was likely to occur and card passing property was poor.

In order to solve this problem, the present inventors have
Previously, there has been proposed such an aliphatic polyester in which inorganic inert particles are blended as a crystal nucleating agent (Japanese Patent Laid-Open Publication No. Hei 4-
170463 publication). However, the effects of inorganic compounds such as talc, silica, glass chopped strands, titanium oxide, and calcium silicate disclosed in this publication are insufficient, and there is a problem that blocking and tacking are likely to occur particularly in summer. It had been.

[0008]

The present invention has a low melting point,
Moreover, it is intended to provide a polyester composition for a binder fiber, which contains an aliphatic polyester having excellent crystallinity as a main component and provides a binder fiber having good operability during spinning and good card passing property.

[0009]

Means for Solving the Problems As a result of intensive research to solve the above problems, the present inventors have found that it is effective to incorporate swelling synthetic mica into the aliphatic polyester as described above. Heading, arrived at the present invention.

That is, the gist of the present invention is as follows. A polyester composition mainly composed of a structural unit represented by the following formula, having a limiting viscosity of 0.5 or more as a main component, and containing 0.01 to 5% by weight of the composition of swellable synthetic mica during the synthesis of the polyester. , The melting point measured by a differential scanning calorimeter is 80 to 120 ℃, and the difference between the melting point and the crystallization temperature during cooling is 20 ℃ or less, and the heat generation rate during crystallization under cooling is 20 mJ / sec or more. A characteristic polyester composition for binder fibers. _{-OC (CH 2) mCO-O} (CH 2) nO- , where, m is 10 to 20, n is an integer of 2-4.

In the present invention, the measurement with the differential scanning calorimeter is performed under the following conditions. That is, in a nitrogen stream,
After raising the temperature from 0 ° C to 150 ° C at a heating rate of 10 ° C / min and holding for 5 minutes, the temperature was lowered to 0 ° C at a cooling rate of 10 ° C / min, and the cooling crystallization temperature (Tc) was measured. Hold the temperature for a minute, raise the temperature again to 150 ° C at a temperature rising rate of 10 ° C / min, and measure the melting point (Tm). The difference between the melting point Tm at the time of reheating and the cooling crystallization temperature Tc is ΔT. Further, the height of the peak top at the time of temperature falling crystallization is defined as the heat generation rate HF (mJ / sec).

The present invention will be described in detail below.

The polyester used in the present invention has a melting point of 80 ° C.
It is necessary to be above. When the melting point is less than 80 ° C, problems such as blocking of chips and tacking occur when the fibers are formed. In addition, the melting point must be 120 ° C or less in order to use the existing equipment with good thermal efficiency when fiberizing. Furthermore, unless the difference between the melting point and the crystallization temperature at the time of temperature decrease is 20 ° C. or less, tacking or the like occurs during fiber formation, which is not preferable.

The polyester in the present invention is obtained from a linear aliphatic dicarboxylic acid component and an aliphatic glycol component. It is necessary to properly select the combination of m and n in the formula to satisfy the thermal characteristics.

Specific examples of the straight-chain aliphatic dicarboxylic acid component include decane-1,10-dicarboxylic acid and tetradecane-1,14
-Dicarboxylic acid, octadecane-1,18-dicarboxylic acid and ester-forming derivatives thereof are mentioned, but decane-1,10-dicarboxylic acid is economically preferable. As the aliphatic glycol component, ethylene glycol, 1,4-butanediol, 1,3-propanediol or the like is used.

Two or more kinds of dicarboxylic acid components and glycol components may be used in combination, and terephthalic acid, isophthalic acid, phthalic anhydride, 5-sodium sulfoisophthalic acid and succinic acid may be used as long as the effects of the present invention are not impaired. , Glutaric acid, adipic acid, trimellitic acid, sebacic acid,
Oxybenzoic acid, diethylene glycol, propylene glycol, 1,4-cyclohexanedimethanol, 1,6-
Hexane dimethanol or the like may be used in combination as a copolymerization component, or additives such as a matting agent, a stabilizer and a colorant may be added.

The intrinsic viscosity [η] of the polyester of the present invention must be 0.5 or more, preferably 1.0 or more. [Η] is 0.5
If it is smaller, various mechanical and chemical properties are inferior, and
The spinnability is impaired and the performance as a binder fiber becomes insufficient, which is not preferable. However, if [η] is too large, the melt viscosity becomes too high and the spinnability is impaired,
Since it causes gelation and is not preferable, 2.0 or less is desirable.

The polyester of the present invention can be produced by a conventional method. That is, a polyester can be produced by subjecting a dicarboxylic acid component and a glycol component to an esterification or transesterification reaction and then performing a polycondensation reaction.

The polycondensation reaction is usually carried out under reduced pressure of about 0.01 to 10 torr at a temperature of 220 to 280 ° C. until a desired [η] is obtained. The polycondensation reaction is carried out in the presence of a catalyst, and as a catalyst, compounds of metals such as antimony, germanium, tin, titanium, zinc, aluminum, magnesium, potassium, calcium, sodium, manganese, and cobalt which have been conventionally used. Besides, organic sulfonic acid compounds such as sulfosalicylic acid and o-sulfobenzoic anhydride are used.

The catalyst is added in an amount of usually 0.1 × 10 ^{-4 to} 100 × 10 ^-4 mol, preferably 0.5 × 10 ^-4 to 50 × 10 ^-4 mol, and most preferably, 1 mol of the repeating unit of polyester. 1 x 10
^-4 to 10 x 10 ^-4 mol is suitable.

In the present invention, the swellable synthetic mica is mainly composed of a silicic acid salt as a basic structure, and alkali-exchangeable ions such as sodium and lithium are coordinated between layers.
Such a swollen synthetic mica is commercially available as a synthetic mica ME series from Coop Chemical Co., Ltd. and can be used in the present invention.

The swelling synthetic mica preferably has an average particle diameter of 5 μm or less, and if the particle diameter is large, the spinnability is poor. The content of the swelling synthetic mica should be 0.01 to 5% by weight. If the blending amount is too small, the effect as a crystallization accelerator is small, and conversely if the blending amount is too large, the fibers are likely to be cut during spinning or drawing, and the life of the nozzle pack filter is shortened. , It is not possible to manufacture fibers stably.

The swelling synthetic mica needs to be added at the time of synthesizing the polyester, and may be added at the time of esterification or transesterification reaction, or at the stage of polycondensation reaction.

In the present invention, the temperature falling crystallization temperature and the calorific value of the polyester composition can be controlled by the kind and addition amount of the swelling synthetic mica.

By melt spinning the polyester composition of the present invention by a conventional method, binder fibers can be obtained with good operability. When the binder fiber is used, the polyester composition of the present invention can occupy a part or all of the fiber surface, and is usually a conjugate fiber.
Polyethylene terephthalate, polybutylene terephthalate, and high-melting point polyesters containing these as the main components are preferably used as other components in the case of forming the composite fiber.

[0026]

The polyester composition for binder fibers of the present invention is a mixture of swellable synthetic mica during the synthesis of polyester, and the swellable synthetic mica is finely dispersed in the polyester, and this acts as a crystallization accelerator. In the swelling synthetic mica, since an alkali exchange ion such as sodium is coordinated with an interlayer position of a crystal of a silicate salt, a monomer or a polymer enters the interlayer during the reaction and swells. Once swelled, the layer peels off or cracks and is subdivided compared to the particle size at the charging stage, and the action as a crystallization accelerator becomes remarkable. The finely dispersed swellable synthetic mica does not cause secondary agglomeration, has an excellent effect as a crystallization accelerator, and has good spinnability.

Due to the presence of such subdivided swelling synthetic mica, the difference between the melting point and the temperature falling crystallization temperature is 20 ° C.
It is as small as the following, and the heat generation rate during crystallization during cooling is 20 mJ
/ Sec or more, and is rapidly crystallized by cooling, and once crystallized, it does not melt up to around the melting point, and problems such as blocking and tacking do not occur during granulation or melt spinning. Further, when used as a binder fiber, even if the temperature is raised again, a stable state can be maintained up to around the melting point of the polyester, so that the handleability becomes good.

[0028]

EXAMPLES The present invention will now be described by way of examples. In addition, the measuring method of the characteristic value in an example is as follows. Intrinsic viscosity ([η]) Measured at a temperature of 20 ° C using an equal weight mixture of phenol and ethane tetrachloride as a solvent. Melting point (Tm), falling temperature crystallization temperature (Tc), and heat generation rate (HF) Measured under the above-mentioned conditions using a differential scanning calorimeter DSC-7 type manufactured by Perkin Elmer.

Example 1 Decane-1,10-dicarboxylic acid (DDA) and 1.6 times mol of ethylene glycol (EG) of DDA were subjected to an esterification reaction by a conventional method, and 1% by weight of the produced polyester was swellable. Mica: ME-100 manufactured by Coop Chemical Co. was added, and 8 × 10 ^-4 mol of antimony trioxide was added to the esterification reaction product as a catalyst, and polycondensation reaction was carried out at 270 ° C. and 1 torr. It was Extruding the reactants in strands,
After cooling with water, it was cut into chips. The chip was cut smoothly during the production, and no chip blocking occurred. The obtained polyester composition has [η] 1.53, Tm
It was 82 ° C, Tc 66 ° C, and HF 23 mJ / sec. This polyester composition and [η] 0.68 polyethylene terephthalate were mixed using an ordinary melt-spinning apparatus for core-sheath type composite fibers at a spinning temperature of 270 ° C. and a discharge rate of 174 g / min from a spinneret having 265 spinning holes, and a composite. A concentric core-sheath composite fiber with the former sheath was spun at a ratio of 4: 6. There were no problems such as fusion between single yarns and yarn breakage, and spinning could be performed smoothly.

Examples 2 to 7 Using the acids and glycols shown in Table 1, the addition amount of the swelling synthetic mica was changed as shown in Table 1, the same test as in Example 1 was conducted, and the obtained results were obtained. Is shown in Table 1. In all cases, there were no problems during spinning, and the spinning operability was good.

Comparative Examples 1 to 4 Using the acids and glycols shown in Table 1, the addition amount of the swelling synthetic mica was changed as shown in Table 1, the same test as in Example 1 was conducted, and the results obtained. Is shown in Table 1. In Comparative Examples 1 to 3, fusion was generated between the single yarns, and a part of them became ribbon-like, and good fibers could not be obtained. Further, in Comparative Example 4, yarn breakage often occurred during spinning, and spinning could not be smoothly performed.

Comparative Example 5 Instead of the swelling synthetic mica in the example, 2% by weight of non-swelling synthetic mica: MK-110 manufactured by Cope Chemical Co. was blended, and the same test as in Example 1 was carried out. The results are shown in Table 1.
It was shown to. The yarn was often broken during spinning and could not be satisfactorily spun.

[0033]

[Table 1]

In Table 1, the abbreviations for acids and glycols are as follows. 10DA: decane-1,10-dicarboxylic acid 14DA: tetradecane-1,14-dicarboxylic acid 18DA: octadecane-1,18-dicarboxylic acid 2G: ethylene glycol 3G: 1,3-propanediol 4G: 1,4-butanediol

[0035]

Industrial Applicability According to the present invention, there is provided a polyester composition for a binder fiber, which has a low melting point, exhibits excellent crystallinity, and has excellent operability during granulation and spinning.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location D01F 6/62 302 A 6/92 301 Q 8/14 B D04H 1/54 H D06M 15/507

Claims (1)

[Claims] 1. A composition comprising a structural unit represented by the following formula as a main component, a polyester having an intrinsic viscosity of 0.5 or more as a main component, and a swellable synthetic mica at the time of synthesizing the polyester.
A polyester composition containing 0.01 to 5% by weight,
The melting point measured by a differential scanning calorimeter is 80 to 120 ° C, and
A polyester composition for binder fibers, wherein the difference between the melting point and the crystallization temperature during cooling is 20 ° C. or less, and the heat generation rate during crystallization during cooling is 20 mJ / sec or more. _{-OC (CH 2) mCO-O} (CH 2) nO- , where, m is 10 to 20, n is an integer of 2-4.