JPS6257917A - Polyester yarn - Google Patents

Abstract

PURPOSE:Polyester yarn having alkali decomposition resistance and amine decomposition resistance, obtained by adding polyethylene naphthalate polyester to polyethylene terephthalate polyester yarn. CONSTITUTION:The titled polyester yarn comprising (A) polyester yarn comprising a polyester having ethylene terephthalate as a main repeating unit or a copolymer polyester copolymerized with a small amount of a third component (preferably metallic sulfonate group-containing isophthalic acid component), as a main component, mixed with (B) a polyester having ethylene naphthalate as a main repeating unit, wherein crystallization peak of the component B is detected by differential scanning thermal analysis. Preferably the content of the component B satisfies the formula ([A] and [B] are pts.wt. of the components A and B).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application) The present invention relates to polyester fibers. More specifically, the present invention relates to polyester fibers having excellent alkali decomposition resistance and amine decomposition resistance.

(Prior art) Polyester originally has the property of being decomposed by alkalis, amines, etc., and by utilizing this property, in the clothing field, a part of polyester fibers is hydrolyzed (reduced) by alkali treatment, etc. t) Improvement of L texture and/or improvement of gloss has been widely carried out. However, polyester fibers copolymerized with a third component, especially isophthalic Isophthalic fibers containing metal sulfonate groups! ! 2
When polyester fibers are copolymerized and then dyed with a basic dye and subjected to alkali treatment, the weight loss rate is extremely large compared to ordinary polyethylene terephthalate #1M#, making it difficult to achieve uniform sound reduction. It is not possible to improve the feel and/or gloss of such copolyester fibers by alkali treatment.

In order to improve the alkali decomposition resistance of such copolymerized polyester fibers and to make it possible to improve the texture and/or gloss by alkali treatment, for example, the amount of copolymerized isophthalic acid component containing metal sulfonate groups was reduced. The use of polyester has been proposed in JP-A-59-76980 and JP-A-59-53774.

However, even with these methods, the alkali weight loss rate is faster than that of polyester fibers made of ordinary polyethylene terephthalate (CPET), and sufficient dyeing is required to reduce the amount of copolymerization of the isophthalic acid component containing gold y47-sulfonate groups. It has the disadvantage that it is difficult to obtain a good adhesion.

Sincerely, even when using industrial polyester fibers, especially polyester SIWF for rubber reinforcement, and ordinary PET fibers, there is a need for improved thermal stability, and improved hydrolysis resistance and amine decomposition resistance at high temperatures. I'm getting beaten up (・ru.

It is known that polyester fibers having fewer carboxyl groups at the terminals of polyester molecular chains are advantageous for improving such hydrolysis resistance and amine decomposition resistance. It has been proposed to use a reacted polyester (for example, JP-A-54-FI051).

However, if such a method is used, the problem arises that although the terminal power is reduced to lboxyl/yl groups 9, the degree of polymerization of the polyester finally obtained is also reduced.

(Object of the Invention) The object of the present invention is to provide a polyester edge fiber which completely eliminates the characteristics of polyester fibers, especially co-monomer polyesters, and has greatly improved alkali decomposition resistance and amine decomposition resistance. I'm going to do it.

(Structure) As a result of studies to achieve the above object, the present inventors found that polyester copolymerized with a metal sulfonate group-containing isophthalic acid component contains polyethylene naphthalate, which has superior alkali decomposition resistance compared to PET. It was discovered that the polyester fiber obtained by melt blending the polyester fibers has significantly improved alkali decomposition resistance, and the present invention was developed as follows.

That is, the present invention provides a polyester having ethylene terephthalate as a main repeating unit, or a polyester containing ethylene naphthalate at the 34th repeating position (component B), and differential scanning. It is a polyester fiber characterized by a crystallization peak of BM, min detected by hot oil analysis.

Polynisal (component A) as used in the present invention is a polyester having ethylene terephthalate as a main repeating unit, such as polyethylene terephthalate 1 (PET'), and a small amount of a third component, usually 10 mol%. The following may be copolymerized.

As the third component, a metal sulfonate group-containing isophthalic acid component typified by a 5-sodium sulfoisophthalic acid component is preferred.

In addition, in the present invention, the polyester (CBJff1 min) used together with the polyester (component A) is a polyester containing ethylene naphthalate as a main repeating unit, and has a 2,6-naphthalene dicarboxylic acid component and ethylene glycol. Polyethylene naphthalate, which consists of the following components, is typically used.

Note that a part of the 2,6-naphthalene]/;/carboxylic acid component of the above-mentioned bo-noethylene naphthalate may be replaced with other carboxylic acid components, usually up to ]0 mol%, and 4' or ethylene glycylate. A part of the fur component, usually 10 mol% or less, may be replaced with other diol components (.

In the polyester FB'A Vζ of the present invention, a small amount of polyethylene (CB component) is contained in the above-mentioned polynisdel (A component), and differential scanning calorimetry (hereinafter referred to as DSC) is included. It is important that the crystallization peak of component B is detected by
Here, in polyester fibers in which the crystallization peak of component B is not detected, no effect of improving alkali decomposition resistance etc. is observed, and the fibers are formed only of component A and are comparable to the following polyester fibers.

In the present invention, the crystallization peak of component B is at 180
It is preferable that the content of the B component is in the range of 1 to 200-C and satisfies the following formula 13.

[AJ + (BJ) In formula (1), if it is less than 0.5, the effect of improving alkali resistance etc. will be significantly reduced, and if it exceeds 30, the physical properties of the polyester fiber will tend to change drastically. is.

The polyester fiber of the present invention described above can be obtained by melt-blending the A component and the B component in a whole bath, and then melt-spinning the fiber.
Therefore, it can be obtained.

At this time, in the obtained polyester fiber L fiber, DS
The conditions under which the crystallization peak of component B is detected by Cic processing and the spinning condition is good are when the following formulas [■] and [■] are simultaneously satisfied.7+.

35-te(TB 250)Xtn+(TS-250
)Xts<350 --CIIIO15min≦t9+
ts-s 10 minutes ・・・・・・・・・・・・・・・
・CI[l] Here, TB or Ts exceeds 320°C, or the value of the [mouth] formula is 350
Polyester #JII obtained after removing for 10 minutes
In the male, no crystallization peak of component B was detected by DSC, and no improvement effect on alkali decomposition resistance, etc. was observed.

In addition, 'rn or HTS is less than 280℃, or (II)
If the value of the formula 1 or (Ill) is less than 35 or 0.5 minutes, then the Aff component and the B component are uniformly blended.
-'L, the spinning condition becomes stratified.

In the above-mentioned melt blending method, any method can be used for melt blending, and it is preferable to carry out the melt blending using a single-screw double-screw router.

Alternatively, the polymer after melt blending can be made into chips and then subjected to melt spinning, or it can be directly subjected to melt spinning in a molten state without being made into chips.

(Function) Generally, when melt-blending a copolymerized polyester copolymerized with PET or a metal sulfonate group-containing inphthalic acid component, and a smaller amount of polyethylene naphthalate than the polyester, the melt-blending time is Over time, both transform into block copolymers and/or random copolymers.

This indicates that the crystallization peak iD of the polyethylene binder in the polymer obtained by varying the melt blending time
This can be understood from the fact that when measured using SC, the size of the crystallization peak decreases as the melt blending time increases, and KH finally disappears.

On the other hand, in the polyester fiber of the present invention, since the crystallization peak of polyethylene naphthalate is detected by DSCK processing, free polyethylene naphthalate is present in the fiber.

In addition, polyethylene naphthalate has excellent alkali decomposition resistance, and if the crystallization peak of such polyethylene naphthalate is not detected by DSCK, the alkali decomposition resistance is normal for polyester fiber pots made of a single component. From this, it is presumed that in the polyester fiber of the present invention, free 4) polyethylene naphthalate exists at a high density near the outer periphery of the fiber.

(Effect) As shown in the examples below, the polyester fiber of the present invention can withstand the copolymerization iR of the metal sulfonate group-containing isophthalic acid component without reducing the copolymerization iR of the metal sulfonate group-containing isophthalic acid component. It is possible to completely improve the alkali decomposition property.

(Example) Examples 1 to 4. Comparative Examples 1 to 4 100 parts of dimethyl terephthalate, 8 parts of dimethyl (5-sodium sulfo)isophthalate.

60 parts of ethylene glycol, calcium acetate] water salt 06
Part 06, all transesterified into a mortar under nitrogen gas atmosphere 4
The temperature was raised from 140° C. to 230° C. over time, and the transesterification reaction was carried out while distilling the generated methanol out of the system. During this process, when the internal temperature was 170°C (ester reaction rate 50%), 2 parts of Na acetate was added. Subsequently, 0.058 parts of trimethyl phosphate was added to the obtained raw reaction mixture, followed by 0.04 parts of antimony dioxide, and the mixture was transferred to a polymerization vessel. Next, the pressure was reduced from 760 m119 to lmmHg over 1 hour, and at the same time, the pressure was reduced to 2 mmHg over 1 hour and 30 minutes.
The temperature was raised from 30°C to 285°C. Furthermore 1+mmt1
Step 9: Polyester (A) was obtained by reacting for 2 hours at a polymerization temperature of 285° C. under reduced pressure of 9 or less.

Dimethyl 2,6-naphthalene dicarboxylate 1QO9
, 50 parts of ethylene glycol, Cal/Rum acetate] water salt 0
．． 06 parts were charged into a transesterification mill under nitrogen gas atmosphere 4
The temperature was raised from 140°C to 230°C over a period of time, and the transesterification reaction was carried out while distilling the generated methanol out of the system. The reaction product obtained was added with 0.048 parts of trimenal phosphate, then 0.0 parts of antimony trioxide.
．． 033 parts were added and transferred to a plywood can. Next, the pressure was reduced from 760 mm 11 g to 1 mm 11 g over 1 hour, and at the same time the pressure was reduced from 760 mm 11 g to 1 mm mm 1 L over 1 hour and 30 minutes, and at the same time, the pressure was reduced to 23 mm over 1 hour and 30 minutes.
The temperature was raised from 0°C to 285°C. Further 1ma+19
Polyester CB) was obtained by the following polymerization heat treatment under reduced pressure and reaction at 285° C. for 2 hours.

The amounts of these polyesters (A) and CB) shown in Table 1 were melted using a two-screw ruder at the temperature (TB) and melting time (tB>) shown in Table 1, and then formed into chips.

This chip was spun using a spinneret with 24 circular spinning holes of hole diameter t) and 3 mm, and the spinning temperature (TB) was 285.
℃ under conditions where the polymer residence time (ts) during spinning is 2 minutes, and then stretched to 3.5 times according to a conventional method at ~.
A multifilament of 75 denier/24 filaments was obtained by drawing the multifilament at a double speed.The multifilament was made into a knitted rope, and after scouring and presetting in the usual manner, it was boiled with a 1% aqueous sodium hydroxide solution. Treated at tow temperature for 90 minutes, reduced by 1
Find one car and show it in Table 1 as follows.

Furthermore, the crystallization peak i DS of the polyester (B) component in the polyester forming the multifilament j-
CKL was measured and the results are also listed in Table 1.The DSC measurement conditions at this time are shown below.

Claims (1)

[Scope of Claims] (1) A polyester fiber in which the main component (component A) is a polyester having ethylene terephthalate as a main repeating unit or a copolymerized polyester in which a small amount of a third component is copolymerized. A polyester fiber containing polyester (component B) having ethylene naphthalate as a main repeating unit, and in which a crystallization peak of component B is detected by differential scanning calorimetry. (2) The polyester fiber according to claim (1), wherein the content of component B satisfies the following formula [I]. 0.5≦[B]/[[A]+[B]]×100≦30・
...[I] However, [A] indicates the weight part of the main component (component A) forming the polyester fiber. [B]: Indicates parts by weight of polyester (component B). (3) The polyester fiber according to claim (1), wherein the crystallization peak of component B exists between 180 and 200°C. (4) The polyester fiber according to claim (1), wherein the third component is a metal sulfonate group-containing isophthalic acid component.