JPH083819A - Manufacture of polyester fiber - Google Patents

Abstract

PURPOSE:To prevent the adhesion of foreign materials on the surface of a spinneret and stabilize a spinning process in melt spinning of polyester filament composed of the mixture of polyethylene terephthalate and polybutylene terephthalate. CONSTITUTION:A polyester mixture obtained by mixing (A) a polyester resin having butylene terephthalate as a main recurring unit and obtained by lowering catalyst activity by treating the product polymerized in the presence of a titanate catalyst with a phosphoric acid-based stabilizer and (B) a polyester resin having ethylene terephthalate as a main recurring unit and obtained by lowering the catalyst activity by treating the product polymerized in the presence of germanium oxide catalyst with water, in the weight ratio of (A):(B)=5:95 to 95:5 is subjected to melt spinning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyester fiber in which polyethylene terephthalate (hereinafter abbreviated as PET) and polybutylene terephthalate (hereinafter abbreviated as PBT) are mixed, and more specifically, an ester. The present invention relates to a method for suppressing the exchange reaction and producing a mixed polyester fiber in good process condition.

[0002]

2. Description of the Related Art PET fibers are widely used for clothing because of their excellent mechanical and thermal properties. On the other hand, PB
Since T-fiber also has unique repulsion and stretch elastic recovery properties that PET does not have, it is used in fields with high demands for stretchability such as stockings.

Further, various attempts have been made to obtain new polymer alloy fibers by mixing both polyesters and spinning them. For example, Japanese Unexamined Patent Publication (Kokai) No. 57-193536 discloses that a strong twisted yarn having a high twist-stop setting property and a high wrinkle development property can be obtained by mixing both polyesters. Japanese Patent Publication No. 63-42007 discloses that the mechanical properties of spun yarn are improved during high speed spinning.

However, when the above mixture is melt-spun, the foreign matter on the spinneret surface grows abnormally fast, and as a result, the ejection filament bends and the number of broken yarns increases with the passage of time, resulting in poor process quality. .

[0005]

[Means for Solving the Problems] As a result of intensive investigations, the inventors of the present invention deactivated the polymerization catalyst of both polymers to obtain a PBT / PET mixed fiber yarn having a stable process tone.
When suppressing the transesterification reaction, it was clarified that oligomers and sublimable substances are few, foreign matter on the die surface is reduced, and the mechanical properties of the obtained polyester fiber can be improved.

That is, an object of the present invention is to provide a PBT / PET mixed fiber which is excellent in bathochromic property, elastic recovery property and spinning process property. According to the present invention,
After polymerizing using (A) a titanate-based catalyst, a polyester having butylene terephthalate as a main repeating unit, the catalytic activity of which is reduced by a phosphoric acid-based stabilizer, and (B) a germanium oxide-based catalyst are used for polymerization. After that, a polyester mixture in which a polyester having ethylene terephthalate as a main repeating unit, the catalytic activity of which has been lowered by water treatment, is mixed in a weight ratio of (A) :( B) = 5: 95 to 95: 5 is used. A method for producing a polyester fiber, which comprises melt spinning, is provided.

In the PBT used in the present invention, it is necessary that 80 mol% or more, preferably 90 mol% or more of the repeating unit is composed of butylene terephthalate. If the butylene terephthalate content is less than 80 mol%, the washing resistance, weather resistance and the like will be reduced.

The above polybutylene terephthalate contains 20
The third component, for example, diphthalic acid such as isophthalic acid, phthalic acid, methyl terephthalic acid, adipic acid, or diglycol such as ethylene glycol, trimethylene glycol or neopentyl glycol, is used in a proportion of not more than 10% by mole, preferably not more than 10% by mole. May be copolymerized with a small amount of other polymer or a matting agent such as titanium oxide or calcium carbonate,
Other known additives may be contained.

On the other hand, the PET used in the present invention is
80 mol% or more of repeating units, preferably 90 mol%
The above must be composed of ethylene terephthalate. If the content of ethylene terephthalate is less than 80 mol%, a yarn having an excellent spinning process tone, which is the object of the present invention, cannot be obtained.

The above polyethylene terephthalate contains 20
The third component, for example, the above-mentioned dicarboxylic acids and diglycols such as trimethylene glycol, tetramethylene glycol and neopentyl glycol may be copolymerized in a proportion of not more than mol%, preferably not more than 10 mol%, or a small amount thereof. It may contain other polymer, a matting agent such as titanium oxide or calcium carbonate, and other known additives.

In the present invention, the polybutylene terephthalate (PBT) is polymerized using a titanate catalyst, preferably Ti (OBu) ₄ , and after polymerization,
It is necessary that the catalyst has been deactivated by the addition of a phosphoric acid stabilizer such as H ₃ PO ₄ .

When Ti (OBu) ₄ is added with phosphoric acid H ₃ PO ₄ , the butoxy group (--OBu) of Ti and the hydroxyl group (--OH) of phosphoric acid form an inactive complex by a coordinate bond. As a result, Ti (OB) remaining in the polymer
Most of the activity of u) _{4 as} a polymerization catalyst can be deactivated.

Similarly, polyethylene terephthalate (PET) in the present invention is a germanium oxide type catalyst such as G
It has been polymerized using eO ₂ , and it is necessary that the catalyst is deactivated with water or hot water after the polymerization.

GeO₂Is a low temperature quartz four-coordinate structure
Since it has water solubility, it can be treated with hot water.
And aggregate and recombine. As a result, G remaining in PET
eO ₂Still deactivates its ability as a polymerization catalyst to a considerable extent.
Can be done.

In the present invention, the polyester containing polybutylene terephthalate as the main repeating unit is 5 to 95% by weight of the total amount, and the polyester containing polyethylene terephthalate as the main repeating unit is 95% of the total amount.
It is necessary that the polyester mixture is formed by mixing so as to be ˜5% by weight.

When any of the above constituents exceeds 95%, the above-mentioned characteristics as the polymer alloy fiber are completely lost.

The polyester fiber obtained by the present invention preferably has a total denier of 30 to 200 de and a single yarn denier of 0.3 to 10 de. If the total denier is less than 30 de, or exceeds 200 de, or if the single yarn denier exceeds 10 de, it is unsuitable as a fiber for clothing. Single yarn denier is 0.3d
If it is less than e, the number of single yarn breaks during yarn production increases.

The deactivation of the catalytic activity as used in the present invention means, for example, after treating PBT or PET as described above,
When the repolymerization reaction is carried out at 285 ° C. for 3 hours under 0.1 Torr, the increase in intrinsic viscosity is less than 5%.

In order to enhance the deactivating effect of the catalyst, PBT is used.
In this case, it is important that the phosphoric acid to be added is dispersed in ether, and as an effective addition method thereof, a method of directly adding phosphoric acid to the polymerization kettle at the final stage of the polymerization is preferable.

In the case of PET, it is preferable to leave the chips in water at room temperature for 3 to 5 hours in order to promote recrystallization of GeO ₂ . At this time, if hot water having a temperature near Tg of PET is used, the diffusion of water into the chip is accelerated, and the deactivation treatment can be performed in a short time.

In general, the accumulation of oligomers and sublimates on the spinneret surface causes yarn breakage, so periodic cleaning of the spinneret surface is essential. In particular, in the production of PBT / PET mixed fibers in which the conventional catalytic activity is not deactivated, the growth of foreign matter on the spinneret surface was abnormally fast and the yarn breakage occurred frequently. Generation of oligomers during the process is suppressed, foreign matter in the spinneret is small, and the spinning process condition is extremely good.

Further, the polyester fiber obtained by the present invention is excellent in bathochromism. That is, PET of the same denier
/ PBT mixed fiber and PET alone fiber are dyed under atmospheric pressure (10
(0 ° C.) and high pressure dyeing (130 ° C.), and the L value representing the dyeing ratio was measured. The L value of the mixed fiber dyed under atmospheric pressure was smaller than the L value of the fiber of PET dyed under high pressure, that is, It was found that the dyeing property was high.

Generally, a yarn made of PET is subjected to high-pressure dyeing in order to improve dyeability, but when mixed with fibers that cannot be dyed under high pressure, such as wool, it is subjected to normal pressure. Inevitably, it causes staining spots, which often causes problems during use.

However, the polyester fiber obtained by the present invention has sufficient dyeability even at room temperature dyeing at 100 ° C. or lower, and such a problem cannot occur.

Furthermore, the polyester fiber obtained by the present invention has excellent elastic recovery. The characteristics are PBT
Has a property of contracting to the original stable form by heating after taking a form in which the molecular chain is elongated by extension.

Therefore, by utilizing this elastic recovery property, it becomes possible to satisfy characteristics such as wear fatigue.
In other words, the slack caused by the action of wearing, particularly in the elbows, knees, and the like where stress is concentrated, does not return to its original state after being stretched in the case of a material using fibers of PET alone, which causes fatigue and deformation.

However, in the case of the mixed fiber with PBT, the elastic recovery is exhibited even at room temperature, and the fiber is almost completely recovered by the heat of the iron or the like. Therefore, the yarn is most suitable for the design of textiles with less fatigue and deformation. .

In the present invention, the mixed fiber can be produced by ordinary melt spinning including high speed spinning. The undrawn yarn spun, like drawing-heat treatment-winding
The spinning may be carried out in separate steps, or the spinning may be completed only by the spinning step by high-speed spinning.

Regarding the mixing method of PBT / PET, any one of a method of mixing in a chip shape before being put into the hopper of a melt spinning machine, a method of plasticizing and melting and then mixing in a molten state, and other conventionally known mixing methods May be adopted,
In order to secure the stability of spinning, it is preferable to make the residence time of both polymers in a mixed state as short as possible.

When the thus-obtained spun-up yarn (undrawn yarn) or drawn yarn drawn at a predetermined draw ratio is subjected to false twisting, higher crimpability may be imparted. it can.

This is because PBT / PE having different heat shrinkage stresses.
This is due to the latent crimping force generated at the T interface,
A mixed fiber of PBT and PET in which the activity of the polymerization catalyst is not deactivated becomes a copolymer by transesterification, and it is not possible to obtain a high crimpability like the polyester fiber obtained by the present invention.

For the above false twisting, any false twisting device such as a spindle false twisting device, a friction false twisting device, a fluid false twisting device, and an arbitrary heater such as a contact or non-contact heater can be used.

The false twist heater temperature can be arbitrarily selected in the range of 80 to 220 ° C. However, if the draw ratio is small, untwisted parts will be formed and the texture of the fabric will be deteriorated. Is preferred.

The false-twisted yarn thus obtained has a bathochromic property, an excellent elastic recovery property, an appropriate texture and a high bulkiness.

Further, the polyester fiber obtained in the present invention is mixed or twisted with other yarns, such as polyester crimped yarn, polyester flat yarn, nylon crimped yarn, nylon flat yarn, etc., if necessary, and is conventionally used. It is possible to create a non-woven fabric texture.

[0036]

EXAMPLES The present invention will be described in more detail with reference to the following examples. In the examples, the amount of oligomers in the fiber, which is an index of yarn-forming stability, sublimable foreign matter, process tone, yarn mechanical properties, and depth The color property and elastic recovery property are measured by the following methods.

(A) Intrinsic viscosity of chips PBT and PET chips before mixing were measured using a 35 ° C. solution of orthochlorophenol.

(B) Amount of Oligomer Containing Yarns 3 g of yarns were placed in a Soxhlet extractor and subjected to reflux extraction with chloroform for 6 hours. The extract was filtered with a filter paper to dry the filtrate, and then the oil component was removed. Elution fractionation was carried out with an n-hexane / ethanol mixed solution, and the amount of oligomer contained in the yarn was weighed.

(C) Generation of sublimate: 2 g of the yarn is placed on the heater, a separable flask having a volume of 500 ml is covered, and the temperature of the heater is 300 ° C. for about 5 minutes.
After heating for a period of time, the sublimate was adsorbed to the flask and visually judged.

(D) Condition of spinning process PBT and PET chips are dried at 160 ° C. for 5 hours, then spun at a cylinder temperature of 285 to 295 ° C., a spinneret temperature of 285 ° C. and a winding speed of 1500 m / min, and a denier after stretching is 75.
Adjust the discharge rate to be de / 72 filament,
After continuous operation for 96 hours, the presence or absence of yarn breakage and the accumulated state of foreign matter on the spinneret surface were examined.

(E) Bathochromic property Macbeth Co. spectrophotometer Macbeth Color--
L values were measured using EYE, model M-2020PL. The smaller the L value is, the darker the color is.

(F) Elastic recovery rate A tension of 50 mg / de is applied to the yarn and the yarn is wound on a hank frame to take a hank of about 300 de. After making the cassette, hang an initial load of 10 mg / de on one end of the cassette to obtain an initial cassette length l ₀
Measure (cm).

Then, a heavy load (weight Xg / de) is suspended and the length l ₁ (cm) after 1 minute is measured. At this time, the expansion rate El (%) is calculated by the following formula. El = (l ₁ −l ₀ ) / l ₀ × 100

Then, the heavy load is removed and 10 mg / de
In boiling water at 100 ° C under the initial load of 2
Process for 0 minutes. Immediately after boiling water treatment, remove the initial load,
Let it dry naturally for 24 hours.

10 mg / d again on naturally dried yarn
The initial load of e is hung and the length after 1 minute is l ₂ (cm)
Is measured, and the residual strain H (%) is calculated by the following equation. H = (l ₂ −l ₀ ) / l ₀ × 100

By the above method, the value of the heavy load X was sequentially changed, and the elongation rate El (%) when the residual strain H (%) became 0 was obtained, and this value was taken as the elastic recovery rate.

Example 1 A PET chip having an intrinsic viscosity [η] = 0.75, in which a GeO ₂ catalyst was used as a polymerization catalyst, was treated with water in a granular form to suppress its catalytic activity, and Ti (OBu) was used.
₄ was used as a polymerization catalyst, and PBT chips having an intrinsic viscosity [η] = 0.84 obtained by adding 8 mmol% of H ₃ PO ₄ to dimethyl terephthalate as a polymerization raw material at the end of the polymerization were dried at 160 ° C. × 4 hours. Blend ratio PE
T80 wt% and PBT 20 wt% were mixed in a chip form.

Then, using a commercially available spinning machine,
Plasticized and melted at 295 ℃, diameter 0.3mm round cross section hole 72
Dispense from a spinneret with a temperature of 285 ° C and a spinning speed of 1
It was wound up at 500 m / min. The discharge amount was adjusted so that the denier after stretching was 75 de.

Further, the wound undrawn yarn was drawn using a commercially available one-stage drawing machine so that the cutting elongation after drawing was 30%.

Comparative Example 1 PET having an intrinsic viscosity [η] = 0.75 using a GeO ₂ catalyst as a polymerization catalyst, and Ti
Intrinsic viscosity [η] = using (OBu) ₄ as a polymerization catalyst
Each 0.88 PBT was dried at 160 ° C. for 5 hours, then mixed in a chip shape at a ratio of 20 wt% PBT and 80 wt% PET, and spun and stretched in the same manner as in Example 1.

The results are shown in Table 1.

[0052]

[Table 1]

As shown in Table 1, in Example 1 in which the polymer having deactivated polymerization catalyst activity was used, oligomers and sublimates were reduced, the spinning process condition was good, and the mechanical properties of the obtained polyester fiber were also good. high.

[Comparative Example 2] 160 PET having an intrinsic viscosity (η) = 0.75 using a GeO ₂ catalyst as a polymerization catalyst was used.
After drying at 5 ° C. for 5 hours, spinning and drawing were performed in the same manner as in Example 1.
Furthermore, the yarn obtained in Example 1 was dyed under the following dyeing conditions.

Dyeing conditions Dye: Eastman Polyester Blue GLF Dye ratio: 4% by weight with respect to the tubular knit material Auxiliary agent: Monogen 0.5% / 1 Bath ratio: 1/100 Temperature × time: 100 ° C. × 60 minutes reduction cleaning treatment Condition Bath composition: Hydrosulfite 2g / l NaoH 2g / l Acylazine-D 2g / l Temperature x time: 80 ° C x 20 minutes

The results are shown in Table 2.

[0057]

[Table 2]

The fiber of Example 1 is excellent in bathochromism and has a very clear color tone. The elastic recovery rate is 15%, which is 100% by heating even after stretching to 15%.
% Means to recover.

On the other hand, in Comparative Example 2, when 5% or more is stretched, residual strain occurs, which causes wearing fatigue.

[0060]

[Effect] According to the present invention, by deactivating the activity of the polymerization catalyst of both PBT / PET polymers, it is possible to prevent foreign matter from adhering to the spinneret surface, and thus excellent in spinning stability, bathochromicity, and elastic recovery. It is possible to provide the polyester fiber.

Further, the above-mentioned fibers alone or by false-twisting and mixing with other yarns can create a texture and a texture which have not been hitherto obtained, and not only woven fabrics but also knitted fabrics or lace curtains. It can be used in the interior field.

Front Page Continuation (72) Inventor Toshinasa Kuroda, 3-4-1, Mihara, Ibaraki City, Osaka Prefecture Teijin Limited Osaka Research Center

Claims (2)

[Claims] 1. A polyester containing, as a main repeating unit, butylene terephthalate, which is obtained by polymerizing (A) a titanate catalyst and then reducing its catalytic activity with a phosphoric acid stabilizer, and (B) a germanium oxide catalyst. A polyester having ethylene terephthalate as a main repeating unit, which has been reduced in its catalytic activity by water treatment after being polymerized using (A) :( B) = 5: 95-9
A method for producing a polyester fiber, which comprises melt-spinning a polyester mixture mixed in a weight ratio of 5: 5. 2. The method for producing a polyester fiber according to claim 1, wherein the polyester fiber is a false twist textured yarn.