JPH06145323A - 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 the capability of oriented crystallization 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 formulas I and/or II, the constituent diol residues are substantially diol residues of formulas III and IV in a molar ratio of 10/90-70/30 and wherein the intrinsic viscosity is 0.4 or above when measured in a p-xhlorophenol/1,1,2,2/tetrachloroethane (40-60 by weight) solvent mixture.

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 or polyethylene-2,6-naphthalate and an aliphatic diol are mechanically
Due to its excellent physical and chemical properties, it is widely used for clothing, industrial fibers, and other molded products.

Generally, polyethylene terephthalate or polyethylene-2,6-naphthalate 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 equipment 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.

[0005]

The main object of the present invention is to remedy the drawbacks of conventional polyesters such as those mentioned above,
It is intended to provide a novel copolyester having 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]

The present invention achieves the above-mentioned object, wherein the dicarboxylic acid residue constituting the polyester is substantially the following (A) and / or (B) And the diol residue is substantially the following (C) and the following (D) diol residue, and (C) /
A copolymerized polyester having a molar ratio of (D) of 10/90 to 70/30, wherein p-chlorophenol / 1,
1,2,2-Tetrachloroethane (weight ratio 40/60)
The intrinsic viscosity measured at 35 ° C using the mixed solvent of is 0.4
The present invention relates to a copolyester and fibers thereof characterized by the above.

[0008]

[Chemical 2]

That is, the copolyester of the present invention is substantially composed of the above-mentioned (A) and / or (B) dicarboxylic acid residues and the above-mentioned (C) and (C) diol residues. Copolymerized polyester having a molar ratio of (C) / (D) in the diol residue of 10/9
It is a substantially linear polymer of 0-70 / 30.

The naphthalene-2,6-dicarboxylic acid residue of the above (A) or the 6,6 '-(di-β-of the above (B)
Although a polyester comprising a naphthoxyethane) dicarboxylic acid residue and an ethylene glycol residue of the above (D) is conventionally known, the copolymerized polyester of the present invention can be used as a diol component in addition to the above (D) component and above (C). It is a novel copolymer which is obtained by copolymerizing the components in a specific ratio and has never been known.

In the copolymer of the present invention, by copolymerizing the above component (C) in an amount of 10 to 70 mol%, the molecular orientation (as-spun orientation) in melt spinning becomes large, and melt spinning alone is sufficient. It exhibits a unique property that it can be made into a fiber having excellent mechanical properties.

Therefore, in the copolyester of the present invention, the unit represented by the above formula (C) is used as a diol component to be combined with the above dicarboxylic acid component, in an amount of 10 to 70 mol% of all diol residues, and It is necessary to contain the unit represented by the above formula (D) in an amount of 30 to 90 mol% of all diol residues. Here, when the unit of the above formula (C) is less than 10 mol%, the orientation in melt spinning is lowered,
On the other hand, when it exceeds 70 mol%, the melting point of the obtained polymer becomes high and the thermal stability for a long time under the melt molding condition is lacking, so that both are preferable.

As the dicarboxylic acid component, the above-mentioned (A) and (B) may be used alone or in combination. When they are used in combination, one of the components is 60 of the total acid component. It is preferable to occupy at least mol%, particularly at least 70 mol%.

According to the research conducted by the present inventors, when the acid component is substantially the above (A), the molar ratio (C) / (D) of the copolymerization of the diol components (C) and (D). 30/70 ~
It is preferably 60/40, and when the acid component is substantially (B), the copolymerization molar ratio (C) /
It has been found that (D) is preferably 30/70 to 70/30 in terms of moldability and mechanical properties of the molded product (fiber).

That is, by selecting the copolymerization molar ratio (C) / (D) of the diol component corresponding to the acid component as described above, both the orientation and the spinning stability in melt spinning are sufficiently satisfied. It can be a polymer.

The intrinsic viscosity of the polyester 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, and serves as a parameter indicating the degree of polymerization of the polymer.

The copolymerized polyester of the present invention can be used for the melting point measurement, elemental analysis and infrared absorption spectrum analysis (I
R) and nuclear magnetic absorption spectrum analysis (NMR).

The copolyester of the present invention comprises at least one aromatic dicarboxylic acid or its ester derivative represented by the following formulas (1) and (2) and two types represented by the following formulas (3) and (4). It is produced by heating and reacting a mixture of the above diol with a diol and performing melt polymerization.

[0019]

[Chemical 3]

[In the above formulas (1) and (2), R
Is a hydrogen atom, 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 a Grignard compound obtained by a reaction of dibromobenzene and magnesium with ethylene oxide can be adopted.

In the case of producing the copolyester of the present invention, the dicarboxylic acid component is represented by the above formulas (1) and (2).
At least one dicarboxylic acid or ester thereof is used, but another dicarboxylic acid, hydroxycarboxylic acid or ester-forming derivative thereof may be used within the range not impairing the crystallinity of the copolyester (eg, a ratio of less than 10 mol%). You may use together. Such other dicarboxylic acids include, for example, terephthalic acid, isophthalic acid, 4,
4'-biphenyldicarboxylic acid, 4,4'-diphenoxyethanedicarboxylic acid, adipic acid, sebacic acid, azelaic acid, cyclohexane-1,4-dicarboxylic acid and the like can be mentioned. Other hydroxycarboxylic acids include hydroxybenzoic acid, hydroxynaphthoic acid, 4-
Examples thereof include hydroxycyclohexanecarboxylic acid.

On the other hand, both diol compounds of the above formulas (3) and (4) are used as the diol component, but other diols may be used in combination as long as the crystallinity of the copolyester is not impaired. 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. Examples thereof include naphthalene and 4,4'-dihydroxydiphenyl.

In the copolyester of the present invention, a mixture of a dicarboxylic acid represented by the above formulas (1) and (2) or its ester derivative and a diol represented by the above formulas (3) and (4) is reacted by heating. Although it is produced by melt polymerization, the 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 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.

The copolyester of the present invention can be used in various shapes because it can be easily processed / molded into fibers, films and other molded products, and its industrial significance is extremely large. In addition, the copolyester of the present invention, particularly when used for fibers, only causes the spun yarn to be wound at a high draft in melt spinning to cause oriented crystallization without post-stretching and expresses high mechanical properties. It has the excellent molding characteristics of

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
Other types of thermoplastic polymers, stabilizers for UV absorbers, antioxidants, plasticizers, lubricants, flame retardants, mold release agents, if necessary.
A pigment, a nucleating agent, a filler, or a reinforcing material such as glass fiber or carbon fiber can be added.

[0028]

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.

[0029]

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

The reference example is a production example of 1,4-benzenediethanol which is a raw material of the copolyester of the present invention. In addition, "part" in an example means a "weight part."

Various evaluation items mentioned in the examples were obtained 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 a single fiber having a test length of 25 mm to a constant speed tensile test at a tensile speed of 100% per minute.

[0035]

Reference Example This reference example shows an example of the synthesis of 1,4-benzenediethanol.

36 g of magnesium was dispersed in 900 ml of tetrahydrofuran to obtain 150 g of p-dibromobenzene.
Was dissolved in 600 ml of tetrahydrofuran and added dropwise over 2 hours. A small amount of 1,2-dibromoethane was added to this as a reaction initiator, and the mixture was reacted under a nitrogen atmosphere for 16 hours under reflux. The temperature of this reaction solution is 50 ° C to 60 ° C
The solution of 100 g of ethylene oxide dissolved in 150 g of tetrahydrofuran was added dropwise, and then 6
The reaction was carried out under reflux for an hour.

The reaction mixture was cooled to 0 ° C., 1 liter of dilute hydrochloric acid was added, the organic layer was separated, dried over sodium sulfate, and then tetrahydrofuran and low-boiling substances were distilled off under reduced pressure. The obtained crude product was recrystallized from a tetrahydrofuran / toluene mixed solvent to obtain high-purity benzenediethanol.

[0038]

EXAMPLE 1 17.0 parts of 2,6-naphthalenedicarboxylic acid dimethyl ester, 9.5 parts of ethylene glycol and 0.0048 parts of titanium tetrabutoxide were charged into a flask equipped with a stirrer and a rectifying column, and 185 ° C.
The reaction was carried out by heating while distilling out the methanol produced at a temperature of from 220 ° C to 220 ° C. 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 rectification column and a distillation system, 3.3 parts of 1,4-benzenediethanol was added thereto, and the mixture was replaced with nitrogen under nitrogen.
Heat to 75 ° C and raise to 290 ° C in 30 minutes, gradually reduce pressure at this temperature to 0.2 mmHg in 30 minutes, then
Polymerized for 5 minutes. This polymer had a melting point of 238 ° C. and an intrinsic viscosity of 0.64.

The copolymerization molar ratio of the diol component in the polymer obtained from the distilling monomer at the time of polymerization was 1,4-benzenediethanol 38 to ethylene glycol 62.

This polymer was extruded from a nozzle having a diameter of 0.2 mm and L / D of 3 at a discharge linear velocity of 0.5 m / min using a plunger type melt spinning machine and wound at a speed of 300 m / min to form a monofilament. Obtained. This monofilament is oriented and its physical properties are Young's modulus 19
6 g / de, tensile strength 5.9 g / de, breaking elongation 5.
It was 5%.

[0042]

Example 2 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 to 220 ° C. was added. The reaction was carried out by heating while distilling it out of the system.
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 rectification column and a distillation system, to which 4.15 parts of 1,4-benzenediethanol was added, and then 275 ° C. under nitrogen substitution. The temperature was raised to 290 ° C. in 30 minutes, and the pressure was gradually reduced at this temperature to 0.2 mmHg in 30 minutes.
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 1,4-benzenediethanol 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 form a monofilament. Obtained. This monofilament is oriented and its physical properties are Young's modulus 25
2 g / de, tensile strength 4.5 g / de, breaking elongation 4.
It was 0%.

Claims (4)

[Claims] 1. The dicarboxylic acid residue constituting the polyester is substantially the following (A) and / or the following (B) dicarboxylic acid residue, and the diol residue is substantially the following (C) and ( A copolymerized polyester having a diol residue of D) and a (C) / (D) molar ratio of 10/90 to 70/30, wherein p-chlorophenol / 1,1,2,2- Tetrachlorethane (weight ratio 40 /
A copolyester having an intrinsic viscosity of 0.4 or more measured at 35 ° C. using the mixed solvent of 60). [Chemical 1] 2. The dicarboxylic acid residue constituting the polyester is substantially the above-mentioned (A) dicarboxylic acid residue, and the diol residue is substantially the above-mentioned (C) and (D) diol residue. And the molar ratio of (C) / (D) is 3
The copolyester according to claim 1, which is 0/70 to 60/40. 3. The dicarboxylic acid residue constituting the polyester is substantially the above (B) dicarboxylic acid residue, and the diol residue is substantially the above (C) and (D) diol residue. And the molar ratio of (C) / (D) is 3
The copolyester according to claim 1, which is 0/70 to 70/30. 4. An oriented fiber comprising the copolymerized polyester according to claim 1, 2 or 3.