JP2022142856A - Copolyester composition - Google Patents

Abstract

To provide a copolyester composition that is less prone to yarn breakage during fiber forming and gives a fiber having both of good coloration and long-term antistatic properties.SOLUTION: A copolyester composition contains a sulfoisophthalic acid residue, and contains a sulfonic acid component represented by the following chemical formula of 9.0-45 mol/kg and an alkaline-earth metal of 3.0-15 mol/kg. R-SO3-R is a C7-30 alkyl group or alkylaryl group.SELECTED DRAWING: None

Description

The present invention relates to a copolymer polyester composition. More particularly, the present invention relates to a copolymer polyester composition which is excellent in fiber moldability and has both coloring properties and antistatic properties when made into fibers.

Polyesters, especially polyesters containing polyethylene terephthalate as a main component, are widely used for fibers, films, bottles, etc. due to their excellent mechanical, dynamic and chemical properties.

It is known to incorporate a sulfoisophthalic residue in order to impart dyeability, particularly when used as clothing fibers. Moreover, a method of adding an alkylsulfonate metal salt or an alkaline earth metal as an antistatic agent is known to impart antistatic properties (Patent Documents 1 and 2).

JP 2015-134907 A JP 2019-151831 A

Patent Document 1 discloses a polyester having a sulfoisophthalic acid residue and containing dodecylbenzenesulfonic acid and an alkaline earth metal salt. Amounts are not specifically disclosed. In addition, the content of dodecylbenzenesulfonic acid is low for clothing fibers, and sufficient antistatic properties cannot be obtained due to bleed-out during molding and shedding during long-term use after molding into fiber products. Moreover, the content of the alkaline earth metal is not specifically disclosed, and long-term antistatic properties cannot be obtained.

Although Patent Document 2 discloses an alkaline earth metal as an example of a catalyst, the antistatic property cannot be maintained for a long period of time, probably because bleed-out cannot be prevented with this amount of reaction catalyst.

As a result of investigations to solve the above problems, it was found that the object of the present invention can be achieved by the following means.
(1) A copolyester composition containing a sulfoisophthalic acid residue, containing 9.0 to 45 mol/kg of a sulfonic acid component represented by the following chemical formula, and 3.0 to 15 mol/kg of an alkaline earth metal: A copolymer polyester composition characterized by comprising:
R ^- _SO3-
R is an alkyl group having 7 to 30 carbon atoms, an alkylaryl group

The copolyester composition of the present invention provides clothing that is excellent in productivity, has good appearance (color development), and is comfortable to wear for a long period of time.

The copolymer polyester composition of the present invention is a polyester whose main components are a dicarboxylic acid component and a diol component. Examples of components include ethylene glycol, 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,4-butanediol, and 1,4-cyclohexanedimethanol. Among them, polyethylene terephthalate composed of terephthalic acid and ethylene glycol is preferable because of its excellent heat resistance. Two or more polyesters can be used in combination.

The copolymer polyester composition of the present invention contains a sulfoisophthalic acid residue in order to exhibit dyeability. Sulfoisophthalic acid residues include 5-sulfoisophthalic acid.

It is preferable that the content of the sulfoisophthalic acid residue is 1.2 mol % or more based on the total dicarboxylic acid, because the dyeing amount of the cationic dye provides sufficient dyeability. In addition, it is preferable that the content of the sulfoisophthalic acid residue is 2.2 mol % or less based on the total dicarboxylic acid component, so that decomposition during melting is suppressed, and spinnability and mechanical properties when made into fibers are improved. . More preferably, it is 1.4 to 1.9 mol %.

The copolymer polyester composition of the present invention is characterized by containing 9.0 to 45 mol/kg of a sulfonic acid component represented by the following chemical formula in order to exhibit antistatic properties.
R ^- _SO3-
R is an alkyl group having 7 to 30 carbon atoms or an alkylaryl group. The sulfonic acid component represented by the above chemical formula is hydrophilic, and is known to prevent static electricity by absorbing moisture on the surface of molded articles such as fibers. there is

R of the sulfonic acid component represented by the chemical formula is an alkyl group or an alkylaryl group, and examples of the alkyl group include octane, decane, dodecane, undecane, dodecane, octadecane, and the like. These alkyl groups may be linear or branched. Examples of alkylaryl groups include toluene, butylbenzene, dibutylbenzene, pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene, nonylbenzene, decylbenzene, undecylbenzene, dodecylbenzene and octadecylbenzene. Also, the alkyl group bonded to the aryl group may be linear or branched.

Among these, an alkylarylsulfonic acid component in which R is an alkylaryl group is preferable from the viewpoint of compatibility with polyester resins and color tone when used as resins and fibers. In particular, dodecylbenzenesulfonic acid is more preferred as a component.

If the sulfonic acid component is less than 9.0 mol/kg, the antistatic properties of the composition and fiber will be poor, and sufficient comfortable wearability will not be obtained. If the sulfonic acid component exceeds 45 mol/kg, the sulfonic acid component bleeds out during melt spinning, causing contamination of the spinneret and leading to yarn breakage, or worsening the color tone (b value) when the composition and fiber are made. or From the viewpoint of spinnability and color tone, the content of the sulfonic acid component is preferably 9.0 to 36 mol/kg, more preferably 9.0 to 27 mol/kg.

The copolyester composition of the present invention contains an alkaline earth metal in order to reduce bleed-out of the sulfonic acid component during melt spinning and drop-off during long-term use of the molded fiber product due to washing and the like. Although the mechanism by which bleed-out and dropout can be prevented by containing an alkaline earth metal has not been elucidated, the mobility of the sulfonic acid component is increased by ionic bonding of 2 mol of the sulfonic acid component per 1 mol of the alkaline earth metal. It is thought that it will be possible to suppress bleed-out during fiber molding and elution during washing.

The alkaline earth metal content of the present invention is 3.0 to 15 mol/kg. If the alkaline earth metal content is less than 3.0 mol/kg, the effect of suppressing bleed-out of the sulfonic acid component during melt spinning cannot be obtained, causing contamination of the spinneret and leading to yarn breakage. On the other hand, if the content of the alkaline earth metal exceeds 15 mol/kg, the alkaline earth metal and the copolyester are combined to form foreign matters, leading to yarn breakage during melt spinning. From the viewpoints of suppression of bleed-out of the sulfonic acid component and spinnability, the content of alkaline earth metal is preferably 3.0 to 12 mol/kg, more preferably 3.0 to 9.0 mol/kg.

The alkaline earth metals of the present invention are Group II metals of the periodic table. Among these, magnesium and calcium are preferable in terms of ease of ionization and easy availability of compounds.

The copolyester composition of the present invention can contain known additives such as particles typified by titanium oxide and silica, antioxidants, anti-coloring agents, and light stabilizers, as long as the objects of the present invention are not impaired.

Specifically, the copolymer polyester composition of the present invention can be produced as follows.
The method for producing the copolyester composition of the present invention is produced by a known polymerization method such as transesterification or esterification. In the transesterification method, an ester-forming derivative of a dicarboxylic acid and a diol are charged into a reaction vessel and reacted at 150 to 250°C in the presence of a transesterification catalyst. can be obtained by heating to 260-300° C. and reacting for 2.5-5 hours.

In the esterification method, a dicarboxylic acid and a diol are placed in a reaction vessel, and the esterification reaction is performed at 150 to 270°C under nitrogen pressure. It can be obtained by heating to 260 to 300° C. and reacting for 2.5 to 5 hours. Each reaction device may be one each, or may be plural.

The method for producing the copolyester composition of the present invention can also be produced by depolymerizing recycled raw materials (recycled raw materials such as PET bottles) with a diol component such as ethylene glycol, and repolymerizing the resulting monomers or oligomers. be.

Since the copolymer polyester composition of the present invention contains a sulfoisophthalic acid residue, a diester of sodium 5-sulfoisophthalate is added so that the sulfoisophthalic acid residue is 1.2 to 2.2 mol% with respect to the total dicarboxylic acid. do. The timing of adding the diester of sodium 5-sulfoisophthalate is not particularly limited, and it may be added together with other raw materials before the transesterification reaction or the esterification reaction, or after the completion of the transesterification reaction or the esterification reaction, the polymerization reaction. may be added before the start of

Examples of diesters of sodium 5-sulfoisophthalate include residues of sulfoisophthalic acid, dimethyl sulfoisophthalate, diethyl sulfoisophthalate, and diglycol sulfoisophthalate. Two or more sulfoisophthalic acid residues can be used in combination.

A metal salt of sulfonic acid is added to the copolyester composition of the present invention. The timing of addition of the metal salt of sulfonic acid is not particularly limited, and it may be added together with other raw materials before the transesterification reaction or esterification reaction, or after the transesterification reaction or esterification reaction is completed and before the polymerization reaction is started. may be added by

Since the copolyester composition of the present invention contains an alkaline earth metal, an alkaline earth metal salt is added. The time of addition of the alkaline earth metal salt is not particularly limited, and it may be added together with other raw materials before the transesterification reaction or esterification reaction, or after the transesterification reaction or esterification reaction is completed and before the polymerization reaction is started. may be added by Also, the alkaline earth metal salt may be added as a catalyst for the esterification reaction or the transesterification reaction. Further, from the viewpoint of promoting ionic bonding between the sulfonic acid component and the alkaline earth metal, it is particularly preferable to pre-mix the compound containing the sulfonic acid component and the compound containing the alkaline earth metal before adding.

Examples of the metal salt of sulfonic acid include a method of adding a metal salt of dodecylbenzenesulfonic acid. Regarding the metal species, alkali metals are preferable from the viewpoint of color tone b value and gelation rate, and sodium, potassium and lithium. is more preferred. Among these, sodium dodecylbenzenesulfonate is particularly preferred from the standpoint of easy availability.

The copolymer polyester composition of the present invention is obtained by diluting a masterbatch of a copolymer polyester composition containing sulfoisophthalic acid residues, a sulfonic acid component represented by the chemical formula, and an alkaline earth metal at a high concentration with another polyester composition. , 9.0 to 45 mol/kg of the sulfonic acid component and 3.0 to 15 mol/kg of the alkaline earth metal are also excellent in productivity, good appearance and long-term antistatic effect can be obtained. .

The method of diluting the masterbatch of the copolyester composition with another polyester composition is not particularly limited, but the copolyester composition of the present invention can be obtained by diluting by a known melt-kneading method.

Further, other polyester compositions for diluting the masterbatch can use recycled raw materials (recycled raw materials such as PET bottles) in addition to ordinary polyester-based raw materials.

The copolyester composition of the present invention can be made into various resin molded articles by using known molding methods such as extrusion molding, blow molding, vacuum molding, and injection molding. It is preferable because it is easy to exhibit preventive properties.

Fibers using the copolymer polyester composition of the present invention can be formed into fibers by suitably using a conventionally known method. For example, a two-step method in which an undrawn polyester yarn obtained by melting and extruding a polyester resin composition is once wound and then drawn, a direct spinning and drawing method in which the spinning step and the drawing step are continuously performed, and a high-speed spinning method. can. Alternatively, a process of winding the yarn as a half-stretched yarn and then stretching the yarn may be employed.

It is preferable that the fiber has a single filament fineness of 10 dtex or less because it is suitable for clothing applications that require antistatic properties. Since the copolyester composition of the present invention can be made into a fiber by a single yarn, it is possible to obtain a fine single yarn fineness fiber, and it is also possible to obtain a single yarn fineness fiber of 1 dtex or less.

The present invention will be described in more detail with reference to the following examples. In addition, physical property values in the examples were measured by the following methods.

(1) Color tone of composition (b value)
The Hunter value (b value) was measured using a color difference meter (SM color computer, model: SM-T45, manufactured by Suga Test Instruments Co., Ltd.), and the b value of the fiber was judged according to the following criteria.
○ (excellent): 10.8 or more and 13.6 or less △ (practical): 9.4 or more and less than 10.8, or greater than 13.6 and 14.0 or less × (not practical): 9. Less than 4, or 14.0 or more (2) Quantitative determination of the sulfonic acid component represented by the chemical formula in the composition Dissolve the composition or fiber in dichloromethane, reprecipitate with methanol, centrifuge, and remove the supernatant. Collect. The supernatant was gently blown with nitrogen gas while being heated to 40° C., concentrated, diluted with methanol, and used as an LC/MS sample. The sulfonic acid component represented by the chemical formula in the LC/MS sample was qualitatively determined using an LC-MS device. In addition, a calibration curve was prepared in advance using a standard solution of the sulfonic acid component corresponding to the chemical formula, and the sulfonic acid component represented by the chemical formula in the composition and fiber was quantified from the total value of free acid and salt.

(3) Quantification of sulfoisophthalic acid residues in the composition The S element content in the polymer was quantified with a fluorescent X-ray spectrometer (ZSR-100e) manufactured by Rigaku Co., Ltd., and represented by the chemical formula quantified in (2). After subtracting the S element content derived from the sulfonic acid component, it was converted to the amount of sulfoisophthalic acid residue.

(4) Determination of Alkaline Earth Metals in Composition The content of alkaline earth metals in the polymer was analyzed with a fluorescent X-ray analyzer (ZSR-100e) manufactured by Rigaku Corporation.

(5) Spinnability (thread breakage)
After vacuum drying at 150°C for 10 hours, a spinneret having 192 round holes with a diameter of 0.17 mm and a discharge hole length of 0.45 mm was used to spin at a spinning temperature of 285°C, a discharge rate of 38 g/min, and a spinning speed of 2000 m/min. The number of yarn breakages (times/ton) when 1 ton of spinning was performed under the conditions was counted and judged according to the following criteria.
○ (excellent): 1.0 times/ton or less △ (practical): greater than 1.0 times/ton and 1.5 times/ton or less × (not practical): greater than 1.5 times/ton.

(6) False Twisting The obtained undrawn yarn was subjected to drawing and false twisting at a draw ratio of 1.5 times using a disk false twisting machine, and the false twisting properties thereof were evaluated according to the following criteria.
◯ (excellent): No thread breakage and almost no dirt on the disc.
(triangle|delta) (workable): There is no thread breakage, but the disc is stained.
x (impossible): Thread breakage occurs frequently. Or, cotton-like dirt adheres to the disc or guide.

(7) Measurement of resistivity of composition (antistatic property)
After thoroughly scouring the sample in a 0.2% by weight weakly alkaline aqueous solution of an anionic surfactant to remove oils and the like, the sample was thoroughly rinsed with water and dried. Then, the sample is aligned into a fiber bundle having a length (L) of 5 cm and a total fineness (D) of 2200 dtex, and is subjected to conditions of a temperature of 10° C. and a humidity of 10% RH (water vapor partial pressure of 0.93 mmHg) for 2 days. After the moisture is left to stand and conditioned, the resistance of the sample is measured at an applied voltage of 500 V using a vibrating capacitive micro-potential measuring device, and the volume resistivity ρ is calculated from the following equation.
ρ=(R×0.9D)/(9×10 ⁵ ×L×d×10 ⁴ )
ρ: specific volume resistance (Ω·cm), R: resistance (Ω), D: total fineness (dtex), L: sample length (cm), d: sample density (g/m ² ).
Using the calculated value ρ, determination was made according to the following criteria.
○ (excellent): 50×10 ⁸ Ω・cm or less △ (practical): greater than 50×10 ⁸ Ω・cm and 100×10 ⁸ Ω・cm or less × (not practical): 100×10 ⁸ Ω・cm larger than cm.

(8) Fiber dyeability (L value)
A tubular knitted fabric was produced from the obtained textured yarn, and this tubular knitted fabric was subjected to C.I. I. Dyeing was performed for 60 minutes in a 95° C. hot aqueous solution with a bath ratio of 1:100 consisting of 5% owf of Basic Blue 66, 0.5 ml / l of acetic acid, and 0.2 g / l of sodium acetate, and the measurement method of (1) was performed. The color tone L value was obtained and judged according to the following criteria.
○ (excellent): less than 45 × (not practical): 45 or more.

[Example 1]
(Production of copolymer polyester composition)
In an esterification reactor charged with 1750 kg of a low polymer of bishydroxyethyl terephthalate and maintained at a temperature of 250° C. and a pressure of 1.2×10 ⁵ Pa, 700 ppm of a 20% aqueous solution of tetraethylammonium hydroxide was added to the low polymer. After the addition, a slurry having a molar ratio of ethylene glycol/terephthalic acid of 1.15 was continuously supplied over 3 hours, and only the water produced during the ester reaction was distilled off from the upper stage of the rectification column, and the reaction vessel temperature was raised to 235. While maintaining the temperature at ~245°C, the reaction was carried out until the esterification reaction rate reached 98%. Next, an ethylene glycol dispersion of 5-sodium sulfoisophthalic acid ethylene glycol adduct and lithium acetate dihydrate are mixed in advance, and 1.6 mol % of sulfoisophthalic acid residues and acetic acid are added to the resulting polyester resin composition. Lithium was added to the ester reaction tank over about 10 minutes so that the lithium content was 0.30 mol %, and the mixture was heated and mixed for about 30 minutes at a stirring speed of 100 rpm. Of this, 1435 kg was filtered through a 10 micron filter and transferred to the polymerization reactor.

To the low polymer transferred to the polymerization reactor, TSF-433 (manufactured by Momentive Performance Materials Japan LLC) was added as a silicone compound so as to be 50 ppm with respect to the resulting polyester resin composition. One minute after the addition of the silicone compound, SONGNOX 1010 (manufactured by Songwon Industrial Co., Ltd.) as an antioxidant was 900 ppm in the polyester resin composition obtained, and 200 ppm in terms of cobalt in the polyester resin composition in which cobalt acetate was obtained. , Sodium dodecylbenzenesulfonate (DBS-Na) and magnesium acetate are mixed in advance so that the molar ratio of DBS-Na/magnesium acetate is 3.0, and 12.3 mol of DBS-Na is added to the resulting polyester resin composition. /kg, and magnesium acetate was added so as to be 4.1 mol/kg in terms of magnesium. 10 minutes after the completion of the addition, polyethylene glycol having a number average molecular weight of 1000 (PEG 1000 manufactured by Sanyo Chemical Industries, Ltd.) was added so as to be 1.0% by weight with respect to the resulting polyester resin composition. After 2 minutes have passed after the addition, the pressure is reduced from normal pressure to 0.1 kPa over 45 minutes. (corresponding to intrinsic viscosity (IV) of 0.69 dl/g), the mixture was extruded into water in strand form and immediately cut to obtain a copolymer polyester composition.
The resulting copolymer polyester composition had a sulfoisophthalic acid residue content of 1.6 mol%, a dodecylbenzenesulfonic acid component (DBS component) content of 12.3 mol%, and a magnesium content of 4.1 mol% ( DBS/Mg=3/1), and the color tone b value was excellent at 11.9.
(Evaluation of silk production)
The resulting copolyester composition was vacuum-dried at 150°C for 10 hours, and then spun at a spinning temperature of 285°C and a discharge amount of 38 g using a spinneret having 192 round holes with a diameter of 0.17 mm and a discharge hole length of 0.45 mm. /min and a spinning speed of 2000 m/min. The thread breakage at this time was 0.7 times/ton, indicating excellent reeling properties.

The resulting undrawn yarn was drawn and false twisted at a draw ratio of 1.5 using a disk false twister to obtain a textured yarn of 66 dtex and 96 filaments.

A tubular knitted fabric was produced using the obtained textured yarn, and the dyeability was evaluated. As a result, the L value was 43.2, indicating excellent dyeability. Moreover, as a result of measuring the specific resistance of the obtained textured yarn, ρ was 43×10 ⁸ Ω·cm, indicating excellent antistatic properties.

[Examples 2 to 10]
A copolyester composition was produced in the same manner as in Example 1, except that the additive content shown in Table 1 was used as a target, and yarn production was evaluated. The results are shown in Table 1 [Examples 11 and 12]
A copolymer polyester composition (master batch) was obtained. The resulting copolymerized polyester composition (masterbatch) was melt-kneaded with polyethylene terephthalate having an intrinsic viscosity of 0.66 using a twin-screw melt-kneader at a blending ratio shown in Table 1 at 280°C to obtain a composition. rice field. Table 1 shows the sulfoisophthalic acid residue content, dodecylbenzenesulfonic acid component content, magnesium content and color tone b value in the obtained composition. Furthermore, melt spinning was performed in the same manner as in Example 1, and the results of spinning evaluation are shown in Table 1.
[Example 13]
1,328 kg of flaky recycled PET raw material obtained by crushing and washing PET bottles and 768 kg of ethylene glycol were put into a depolymerization reactor, heated at 200° C. for 2 hours, and then heated to 240° C. over 2 hours. Next, an ethylene glycol dispersion of 5-sodium sulfoisophthalic acid ethylene glycol adduct and lithium acetate dihydrate are mixed in advance, and 1.6 mol % of sulfoisophthalic acid residue and Lithium acetate was added to the ester reaction tank over about 10 minutes so as to make 0.30 mol % lithium acetate, and after heating and mixing for about 30 minutes at a stirring speed of 100 rpm, it was transferred to the polymerization reaction tank while filtering through a 10 micron filter. liquid.

To the low polymer transferred to the polymerization reactor, TSF-433 (manufactured by Momentive Performance Materials Japan LLC) was added as a silicone compound so as to be 50 ppm with respect to the obtained polyester resin composition. One minute after the addition of the silicone compound, SONGNOX 1010 (manufactured by Songwon Industrial Co., Ltd.) as an antioxidant was 900 ppm in the polyester resin composition obtained, and 200 ppm in terms of cobalt in the polyester resin composition in which cobalt acetate was obtained. , Sodium dodecylbenzenesulfonate (DBS-Na) and magnesium acetate are mixed in advance so that the molar ratio of DBS-Na/magnesium acetate is 3.0, and 12.3 mol of DBS-Na is added to the resulting polyester resin composition. /kg, and magnesium acetate was added so as to be 4.1 mol/kg in terms of magnesium. 10 minutes after the completion of the addition, polyethylene glycol having a number average molecular weight of 1000 (PEG 1000 manufactured by Sanyo Chemical Industries, Ltd.) was added so as to be 1.0% by weight with respect to the resulting polyester resin composition. After 2 minutes have passed after the addition, the pressure is reduced from normal pressure to 0.1 kPa over 45 minutes. (corresponding to intrinsic viscosity (IV) of 0.69 dl/g), the mixture was extruded into water in strand form and immediately cut to obtain a copolymer polyester composition.

The resulting copolymer polyester composition was melt-spun in the same manner as in Example 1, and the spinning was evaluated. Table 1 shows the results. The amount of sulfoisophthalic acid residue in the obtained polyester resin composition was 1.6 mol %, the dodecylbenzenesulfonic acid component (DBS component) was 12.3 mol %, and the magnesium was 4.1 mol % (DBS/Mg = 3/1). The color tone b value was 13.5, and the quality was excellent.

Next, the obtained copolymerized polyester composition was vacuum-dried at 150°C for 10 hours, and then spun at a spinning temperature of 285°C using a spinneret having 192 round holes with a diameter of 0.17 mm and a discharge hole length of 0.45 mm. 1 ton spinning was performed under conditions of a weight of 38 g/min and a spinning speed of 2000 m/min. The yarn breakage at this time was 0.7 times/ton, and stable operation could be performed.

The resulting undrawn yarn was drawn and false twisted at a draw ratio of 1.5 using a disk false twister to obtain a textured yarn of 66 dtex and 96 filaments.

A tubular knitted fabric was produced using the obtained textured yarn, and the dyeability was evaluated. As a result, the L value was 44.2, indicating excellent dyeability. Further, the resistivity of the obtained textured yarn was measured, and ρ was 43×10 ⁸ Ω·cm, indicating good antistatic properties.

[Comparative Examples 1 to 9]
Polymerization and melt spinning were carried out in the same manner as in Example 1, except that the copolymer polyester resin composition was polymerized with the additive content shown in Table 2 as the target, and the spinning was evaluated.

[Comparative Example 10]
Polymerization and melt spinning were carried out in the same manner as in Example 11, except that the copolymer polyester resin composition was polymerized with the additive content shown in Table 2 as the target, and the spinning was evaluated.

Claims (2)

A copolymer polyester composition containing a sulfoisophthalic acid residue, containing 9.0 to 45 mol/kg of a sulfonic acid component represented by the chemical formula below, and 3.0 to 15 mol/kg of an alkaline earth metal. A copolymer polyester composition characterized by R—SO ₃ ^—
R is an alkyl group having 7 to 30 carbon atoms, an alkylaryl group A copolyester composition according to claim 1, wherein the alkaline earth metal is magnesium.