JPH06145322A - Copolyester and fiber thereof - Google Patents

Abstract

PURPOSE:To obtain the title crystalline polyester excellent in melt moldability and mechanical properties and useful for producing a fiber excellent in the capability of oriented crystalization by spinning and chemical and heat resistances by forming a specified copolyester having a specified intrinsic viscosity. CONSTITUTION:A copolyester wherein the constituent dicarboxylic acid residues are substantially dicarboxylic acid residues of formula I, the constituent diol residues are substantially diol residues of formulas II and III in a molar ratio of 10/90-70/30, and wherein the intrinsic viscosity is 0.4 or above when measured in a p-chlorophenol/1,1,2,2-tetrachloroethane (40/60 by weight) solvent mixture at 35 deg.C.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel copolyester and a fiber comprising the copolyester. More specifically, it relates to a crystalline copolyester having excellent melt moldability and mechanical properties, and an oriented fiber obtained by melt spinning the copolyester.

[0002]

2. Description of the Related Art Generally, polyesters, particularly polyesters obtained by polymerizing an aromatic dicarboxylic acid such as polyethylene terephthalate and an aliphatic diol, are
Because of its excellent mechanical, physical and chemical properties, it is widely used for textiles for clothing, industrial fibers and other molded products.

In general, polyethylene terephthalate fibers are produced by melt spinning, but unstretched fibers as extruded from the melt do not have sufficient thermomechanical properties,
Practical fibers cannot be obtained until they undergo an oriented crystallization treatment by heating and stretching unstretched fibers. Therefore, the production of fibers requires various equipments for drawing heat treatment and strict control of molding conditions.

As a means for improving this, p-
A method is known in which a rigid component such as hydroxybenzoic acid is copolymerized with a polyester such as polyethylene terephthalate to form a liquid crystal to obtain an unstretched and oriented crystallized fiber. However, since this method copolymerizes a large amount of p-hydroxybenzoic acid, which is a monomer of a high-melting point polymer, in principle, the polymer does not have sufficient flow molding characteristics, and as a fiber requiring high moldability, It has not been put to practical use, and remains used as a resin for injection molding.

[0005]

The main object of the present invention is to remedy the drawbacks of conventional polyesters such as those mentioned above,
It is to provide a novel copolyester having both excellent melt moldability and mechanical properties.

Another object of the present invention is to provide a molecularly oriented fiber comprising the above-mentioned novel copolyester.

[0007]

Means for Solving the Problems The present invention achieves the above-mentioned object. The dicarboxylic acid residue constituting the polyester is substantially composed of the dicarboxylic acid residue (A) below, and the diol residue is A copolyester substantially consisting of the following diol residues (B) and (C) and having a (B) / (C) molar ratio of 10/90 to 70/30, which comprises p-chloro Phenol / 1,1,2,2
The present invention relates to a copolyester and fibers thereof having an intrinsic viscosity of 0.4 or more measured at 35 ° C. using a mixed solvent of tetrachloroethane (weight ratio 40/60).

[0008]

[Chemical 2]

That is, the copolyester of the present invention is a random copolyester substantially consisting of the dicarboxylic acid residue of (A) above and the two diol residues of (B) and (C) above. It is a substantially linear polymer having a molar ratio of (B) / (C) in the diol residue of 10/90 to 70/30.

Polyesters comprising the above-mentioned (A) dicarboxylic acid residue and the above-mentioned (C) diol residue are conventionally known, but in the present invention, a specific amount of the above-mentioned (B) component as a diol component is added thereto. This is a novel polymer that has been polymerized and has never been known. The present inventor develops the orientation in the melt spinning (as-spun orientation) by using a copolymer in which the specific ratio of the component (C) is replaced with the component (B), and even only the melt spinning is performed. The present invention has been achieved by discovering that a fiber having sufficient mechanical properties can be obtained.

Therefore, in the present invention, the copolymerization ratio of the above (B) and (C) in the diol component combined with the above acid component (A) is important, and the unit represented by the above (B) is 10 to 70. It is necessary to include mol%, preferably 20 to 60 mol%, and 90 to 30 mol%, preferably 80 to 40 mol% of the unit represented by the above (C). If the content of the component (B) is less than 10 mol%, the orientation in the melt spinning will decrease, while 70 mol%
If it exceeds, the melting point of the obtained polymer becomes high,
Since it lacks long-term thermal stability under melt molding conditions,
Both are preferable.

The intrinsic viscosity of the copolyester according to the present invention is 0.4 or more, preferably 0.5 to 2.0. If the intrinsic viscosity is less than 0.4, the molded product obtained from the polyester will have insufficient mechanical properties. The intrinsic viscosity referred to here is a value measured by the method described below,
It is a parameter to know the degree of polymerization of polyester.

Next, the method for producing the copolyester of the present invention will be described.

The copolymerized polyester of the present invention is melt-polymerized by heating a mixture of a dicarboxylic acid represented by the following formula (1) or its ester derivative and a diol compound represented by the following formulas (2) and (3). It is manufactured by

[0015]

[Chemical 3]

[In the above formula (1), R is a hydrogen atom,
It is a lower alkyl group having 1 to 5 carbon atoms, a cycloalkyl group or an optionally substituted phenyl group. As a method of synthesizing the diol compound represented by the above formula (2), for example, a method of reacting 4-hydroxyethylphenol with dibromoethane can be adopted.

In the production of the copolyester of the present invention, the dicarboxylic acid represented by the above formula (1) or its ester derivative is used as the dicarboxylic acid component, but in a range that does not impair the crystallinity of the copolyester (for example, 10).
Other dicarboxylic acids, hydroxycarboxylic acids or ester-forming derivatives thereof may be used in combination at a ratio of less than mol%). Examples of such other dicarboxylic acids include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid, 4,
4'-diphenoxyethanedicarboxylic acid, adipic acid,
Sebacic acid, azelaic acid, cyclohexane-1,4-
Examples thereof include dicarboxylic acid. Examples of other hydroxycarboxylic acids include hydroxybenzoic acid, hydroxynaphthoic acid and 4-hydroxycyclohexanecarboxylic acid.

On the other hand, as the diol component, the diol compounds of the above formulas (2) and (3) are used, but in the range that does not impair the crystallinity of the copolyester (for example, 10).
Other diols may be further used in combination at a ratio of less than mol%). Other diols used in combination include straight-chain glycols such as trimethylene glycol, tetramethylene glycol, hexamethylene glycol, octamethylene glycol, neopentylene glycol, propylene glycol, cyclohexanedimethanol, hydroquinone, resorcin, 2,6-dihydroxy. Naphthalene, 4,4 '
-Examples include dihydroxydiphenyl and the like.

However, in the copolyester of the present invention, it is preferable that the content of the components (A), (B), and (C) other than the residues is as small as possible.
The total content is preferably less than 10 mol%.

In the copolyester of the present invention, a mixture of a dicarboxylic acid represented by the above formula (1) or its ester derivative and a diol compound represented by the above formulas (2) and (3) in a specific ratio is reacted by heating. It is manufactured by melt polymerization. This reaction is usually carried out in the presence of a catalyst using a diol component in an amount of 1.0 to 4.0 mol times that of the acid component.

Examples of the catalyst include sodium, potassium, lithium, calcium, magnesium, barium, tin, strontium, zinc, iron, aluminum, cobalt, lead, nickel, titanium, manganese, antimony and the like, oxides, hydrogen. Compounds, hydroxides, halides, inorganic and organic acid salts, complex salts, double salts, alcoholates, phenolates and the like, and these may be used in combination of two or more. In particular, antimony compounds, germanium compounds and titanium compounds are preferably used as the condensation catalyst. Such a catalyst has an acid component of 0.00
About 5 to 0.5 mol% is preferably used. Preferred polymerization temperatures are temperatures between the melting point of the resulting polymer and 320 ° C, preferably between the melting point + 5 ° C and 300 ° C.

Since the copolyester of the present invention can be easily processed and molded into fibers, films and other molded articles, it can be used in various shapes and its industrial significance is extremely large. Further, the copolymerized polyester of the present invention, particularly when used for fibers, causes molecular orientation and crystallization only by winding the spun yarn at a high draft in melt spinning, and has high mechanical properties without post-stretching. It has an excellent molding property that it can express

For example, fibers from the copolyester of the present invention are prepared as follows. That is, the copolymerized polyester of the present invention is dried to obtain the crystalline melting point Tm of the polymer.
It is melted at a temperature higher than (° C.) and lower than 320 ° C., and is extruded from a spinning nozzle and wound to form an unstretched fiber. At this time, the spinning draft is 5 times or more, preferably 20 times or more. The resulting unstretched (as-spun)
The fibers already have practical mechanical properties due to oriented crystallization, but the unstretched fibers can be further stretched or heat treated if desired. When the glass transition temperature of the polymer is Tg (° C.), the stretching or heat treatment is (Tg
It is preferable to carry out at a temperature of -10 ° C or higher and (Tm-10 ° C) or lower.

The copolymerized polyester of the present invention contains
If necessary, other types of thermoplastic polymers, UV absorber stabilizers, antioxidants, plasticizers, lubricants, flame retardants, mold release agents, pigments, nucleating agents, fillers, glass fibers, carbon fibers, etc. Reinforcing agents and the like can be appropriately mixed.

[0025]

EFFECT OF THE INVENTION The copolyester of the present invention is a material having crystallinity and excellent melt moldability, and can be widely used for fibers, films and molded products. In addition, the fibers are particularly useful for general industrial applications because they have excellent moldability and spin-oriented crystallized properties, and have excellent mechanical properties, heat resistance, and chemical resistance.

[0026]

The present invention will be described below with reference to examples and reference examples, but the examples are for the purpose of explanation and the present invention is not limited thereto.

The reference example is di- [4- (2-hydroxyethyl), which is a raw material of the copolyester of the present invention.
It is an example of production of phenoxy] ethane. In addition, "part" in the example
Means "parts by weight".

The various evaluation items mentioned in the examples were determined as follows.

(A) Melting point: measured by DSC at a temperature rising rate of 10 ° C./min.

(B) Intrinsic viscosity: P-chlorophenol / 1,1,2,2-tetrachloroethane (mixed solvent, mixing weight ratio 4/6) was used as a solvent, the polymer was dissolved, and the polymer concentration was 0. Prepare a solution of 0.5 g / dl, 35 ° C
It was measured at.

(C) Fiber characteristics: Tensile strength, elongation at break, and Young's modulus of fibers were determined by subjecting single fibers having a test length of 25 mm to a constant speed tensile test at a tensile speed of 100% per minute.

[0032]

Reference Example This Reference Example shows a method for synthesizing di- [4- (2-hydroxyethyl) phenoxy] ethane.

P-Hydroxyphenethyl alcohol 6
9 g (0.5 mol) and 28 g (0.5 mol) of KOH were dissolved in 700 ml of water, and 47 g of dibromoethane was dissolved therein.
(0.25 mol) was added dropwise, and the mixture was reacted under reflux for about 8 hours. After cooling, the precipitate was separated by filtration, washed with water, dried, and recrystallized with xylene to obtain di- [4- (2-hydroxyethyl) phenoxy] ethane.

[0034]

Example 1 6,6 ′-(di-β-naphthoxyethane)
22.9 parts of dicarboxylic acid diethyl ester, 6.82 parts of ethylene glycol and 0.0034 part of titanium tetrabutoxide were charged into a flask equipped with a stirrer and a rectification column, and methanol produced at a temperature of 185 ° C to 220 ° C was used as a system. The reaction was carried out by heating while distilling it outside.
After 3 hours, a theoretical amount of methanol was distilled off.

Subsequently, the reaction product was transferred to a polymerization apparatus equipped with a stirrer, a rectifying column and a distilling system, to which di- [4-
(2-Hydroxyethyl) phenoxy] ethane 7.5
After adding 5 parts, the mixture was heated to 275 ° C. under nitrogen substitution, heated to 290 ° C. in 30 minutes, and gradually decompressed at this temperature.
The pressure was adjusted to 0.2 mmHg in 0 minutes and then polymerized for 15 minutes. This polymer had a melting point of 291 ° C. and an intrinsic viscosity of 0.81.

The copolymerization molar ratio of the diol component in the polymer obtained from the distilling monomer at the time of polymerization was di- [4- (2-hydroxyethyl) phenoxy] ethane 48 to ethylene glycol 52.

This polymer was extruded at a linear velocity of 0.5 m / min from a nozzle having a diameter of 0.2 mm and L / D of 3 using a plunger type melt spinning machine and wound at a speed of 100 m / min to obtain a monofilament. did. This monofilament is oriented, and its physical properties are Young's modulus of 260 g.
/ De, tensile strength 3.6 g / de, elongation at break 2.2
%Met.

[0038]

Example 2 A polymer was obtained in exactly the same manner as in Example 1 except that the amount of di- [4- (2-hydroxyethyl) phenoxy] ethane added was 5.3 parts. This polymer had a melting point of 260 ° C. and an intrinsic viscosity of 0.90.

The copolymerization molar ratio of the diol component in the polymer was 33-di- [4- (2-hydroxyethyl) phenoxy] ethane 33 to ethylene glycol, which was determined from the distilling monomer during the polymerization.

The physical properties of the oriented fiber obtained by spinning from this copolymer in the same manner as in Example 1 include Young's modulus of 275 g / de, tensile strength of 4.7 g / de and elongation at break of 3.3%. Met.

Claims (2)

[Claims] 1. The dicarboxylic acid residue constituting the polyester consists essentially of the following (A) dicarboxylic acid residue:
A copolyester having a diol residue consisting essentially of the following (B) and (C) below and having a (B) / (C) molar ratio of 10/90 to 70/30: , P-chlorophenol / 1,1,2,2-tetrachloroethane (weight ratio 40/60) mixed solvent having an intrinsic viscosity of 0.4 or more measured at 35 ° C. Polymerized polyester. [Chemical 1] 2. An oriented fiber comprising the copolyester according to claim 1.