JPH0610212A - Low-temperature dyeable polyester fiber - Google Patents

Abstract

PURPOSE:To provide the subject polyester fiber excellent in low-temperature dyeing properties and color fastness. CONSTITUTION:This polyester fiber is composed of a polyethylene terephthalate- based polyester having 0.5 to 0.7 intrinsic viscosity, in which 0.5 to 5.0mol% sulfonic acid phosphonium salt represented by the formula (A is an aromatic group or an aliphatic group; X1 and X2 are each an ester-forming group; n is a positive integer; R1 to R4 are each H, an alkyl, an aryl or a hydroxyalkyl and the molecular weight is >=60 in total) is copolymerized and exhibits 0.02 to 0.05 birefringence, 1.32 to 1.35g/cm<3> density and >=0% elongation at 95 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester fiber used for clothing, and more particularly to a polyester fiber which can be dyed in a dark to medium color at a low temperature of 100 ° C. or lower.

[0002]

2. Description of the Related Art Generally, polyester fibers, especially polyethylene terephthalate fibers, are used for various purposes because of their strength and many other excellent properties. On the other hand, polyethylene terephthalate fiber has poor dyeability and requires special equipment for dyeing at a high temperature and high pressure of around 130 ° C. Also, it is used in combination with fibers such as wool and acrylic, which deteriorate in properties due to high temperature dyeing. There are some drawbacks such as the limitation.

Several attempts have been made to improve the dyeability of polyethylene terephthalate fiber and to make it dyeable at a low temperature. For example, a method of using a carrier at the time of dyeing is known, but a special carrier is required, and a dyeing solution There are drawbacks such as difficult post-treatment.

As a polyethylene terephthalate with improved dyeability, a copolymer of a metal sulfonate group-containing compound and polyethers is known. However, in order to realize the above low-temperature dyeability, a considerable amount of copolymerization rate is required, and in this case, there is a drawback that the dyeing fastness is inferior.

As another method for improving the dyeability, attempts have been made without chemical modification, and for example, methods such as high speed spinning, high draft spinning, and modified cross-sectioning are known. However, although an approach using only these physical modifying means can obtain a certain level of dyeability, it was impossible to enhance the dyeability to the level of normal pressure boil dyeability.

Naturally, a combination of these modification methods, for example, high-speed spinning of polyester chemically modified with polyethylene glycol or the like has been proposed.
It did not reach a medium to deep dyeing at a temperature lower than 00 ° C.

[0007]

DISCLOSURE OF THE INVENTION The present invention solves the drawbacks of the conventional method, and has a dyeing property which is not available in the past, for example, 100 ° C.
An object of the present invention is to provide a polyester fiber that can be dyed in a dark to medium color at the following low temperatures.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies from the viewpoint of both polymer modification and fiber fine structure modification in order to achieve the above object, and as a result, have a specific copolymerization component and a specific copolymerization component. The polyester fiber having the above-mentioned fiber microstructure was found to have improved dyeability and completed the present invention.

That is, the present invention has the following general formula

[0010]

[Chemical 2]

[Wherein A is an aromatic group or an aliphatic group, X ₁
And X ₂ are the same or different ester-forming functional groups, n
Is a positive integer, R ₁ , R ₂ , R ₃ and R ₄ are hydrogen atoms,
The same or different groups selected from an alkyl group, an aryl group and a hydroxyalkyl group, wherein R ₁ , R ₂ and R
The total molecular weight of ₃ , R ₄ is 60 or more. ] The phosphonium sulfonate represented by
A polyester fiber mainly composed of polyethylene terephthalate having an intrinsic viscosity of 0.5 or more and 0.7 or less, which is copolymerized in a ratio of not less than mol% and not more than 5.0 mol%,
The birefringence Δn is 0.02 or more and 0.05 or less, and the density ρ is 1.
A low-temperature dyeable polyester fiber characterized by having an elongation rate of 32% / cm ³ or more and 1.35 g / cm ³ or less and an elongation at 95 ° C. of 0% or more.

The polyester referred to in the present invention has ethylene terephthalate as a main repeating unit, but may be a polyester in which a part of the terephthalic acid component is replaced with another difunctional carboxylic acid component, and / or a glycol component. It may be a polyester in which a part of is replaced with another glycol or other diol component.

Further, in the polyester of the present invention, additives for matting, antistatic, light resistance and other purposes are contained in an amount of 10 w of the total weight.
Copolymerization and / or blending may be performed at a ratio of t% or less. Further, the polyester fiber of the present invention is required to have an intrinsic viscosity of 0.5 or more and 0.7 or less. When the intrinsic viscosity does not reach 0.5, the mechanical properties of the fiber often become excessively low. On the other hand, when the intrinsic viscosity is more than 0.7, it is more advantageous for improving the dyeability of the present invention, but there is a risk that the spinning condition may be lowered due to the occurrence of yarn breakage in the spinning process.

In the present invention, the following general formula is included in the polymer chain of the above polyester.

[0015]

[Chemical 3]

It is necessary that the phosphonium sulfonic acid salt represented by is copolymerized. In the above general formula, A is an aromatic group or an aliphatic group, preferably an aromatic group. X
₁ and X ₂ are ester-forming functional groups such as a carboxyl group, a chlorocarboxyl group, a hydroxyl group, an acyloxy group, and the like.

[0017]

[Chemical 4]

(Wherein R represents a lower alkyl group or a phenyl group, p represents an integer of 1 or more, and m represents an integer of 2 or more) and the like. X ₁ and X ₂ may be the same or different. R ₁ , R ₂ , R ₃ and R ₄ are a hydrogen atom, an alkyl group, an aryl group or a hydroxyalkyl group, preferably an alkyl group, and particularly preferably a butyl group. This R ₁ , R ₂ , R ₃ , R ₄
May be the same or different. However, the total molecular weight of R ₁ , R ₂ , R ₃ , and R ₄ must be 60 or more for the reason described below. In addition, n is a positive integer, usually 1 or 2.

Such phosphonium sulfonates can generally be easily synthesized by reacting the corresponding sulfonic acids with phosphines or by reacting the corresponding metal sulfonates with phosphonium halides. In the case of synthesizing from sulfonic acid and phosphine, it is not always necessary to isolate and the corresponding sulfonic acid and phosphine may be added to the polyester to be modified to form a salt in the polyester reaction system. However, in the case of synthesizing from a sulfonic acid metal salt and a phosphonium halide, an adverse effect due to the inorganic salt produced, such as a decrease in the softening point due to an excessive side reaction, an adverse effect such that the degree of polymerization cannot be increased occurs It must be added to the polyester after sufficient salt removal.

Specific examples of the sulfonic acid phosphonium salt include 3,5-dicarbomethoxybenzenesulfonic acid tetramethylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid tetrabutylphosphonium salt,
3,5-dicarbomethoxybenzenesulfonic acid tributylmethylphosphonium salt, 2,6-dicarbomethoxynaphthalene-4-sulfonic acid tetrabutylphosphonium salt, 2,6-dicarbomethoxybenzenesulfonic acid tetramethylphosphonium salt, etc. To be

In order to copolymerize the above-mentioned phosphonium sulfonate into the main chain of the polyester, the above-mentioned polyester synthesis may be carried out at an arbitrary stage, preferably the first stage, before the completion of the polyester synthesis.
The above compound may be added at any stage before the reaction in the stage is completed. At this time, if the amount used is too small, the desired dyeability is insufficient. On the other hand, if the amount is too large, the yarn-forming condition becomes poor, and the mechanical properties of the polyester fiber become low. Therefore, the amount is 0.5 mol% or more and 5.0 mol% or less with respect to the difunctional carboxylic acid component constituting the polyester fiber. It is preferred to use in proportion.

The birefringence Δn of the polyester fiber of the present invention must be 0.02 or more and 0.05 or less. Δ
When n does not reach 0.02, the mechanical properties are extremely poor and it cannot be put to practical use. On the other hand, when Δn exceeds 0.05, the dyeability of the polyester fiber has an easy dyeability to the extent that it can be dyed under normal pressure, but there is a limit to the dyeability at low temperatures. In other words, it does not exceed the conventional frame of easily dyeable polyester fiber. On the other hand, Δn is 0.
In the range of 02 to 0.05, an easy dyeing effect which has never been obtained is obtained, and it is possible to dye a medium to dark color even at a low temperature of 100 ° C. or less.

The density ρ of the polyester fiber of the present invention must be 1.32 g / cm ³ or more and 1.35 g / cm ³ or less. When the density does not reach 1.32 g / cm ³ , the polyester fiber has no quality stability and the mechanical properties, thermal properties and dyeability itself change significantly with time.
On the other hand, when the density exceeds 1.35 g / cm ³ , the high dyeability which is the object of the present invention is impossible.

Further, a major feature of the polyester fiber of the present invention is that it exhibits elongation at 95 ° C. (measured by a thermomechanical analyzer described later). Fibers that shrink at this temperature show a correspondingly easy dyeing property, but it is difficult to obtain an extremely high dyeing property such that a medium to dark color is exhibited at 100 ° C. or less as in the present invention. In addition, the fastness of dyeing often deteriorates. As described above, in the polyester fiber of the present invention, the polyester which has been subjected to the specific chemical modification is set to a somewhat lower molecular orientation (Δn) and crystallinity (ρ) than ordinary polyester fiber, and It is characterized by providing self-stretching properties at low temperatures.

The polyester fiber of the present invention described above can be produced by the following yarn making process. First, the first method is to use the modified polyester from 2500 to 3
It is a method in which the yarn is taken up by spinning at a speed of 500 m / min and heat-treated under a slight overfeed. At this time, it is important to set and combine the spinning speed, the draft rate during spinning, the cooling rate, and the overfeed rate during relaxation heat treatment, the heat treatment temperature, and the heat treatment time. However, it is preferable that the spinning draft rate is higher than that during ordinary polyester fiber production, and the cooling rate is more preferable. Further, a larger overfeed rate and a longer heat treatment time are more preferable, but this is determined in consideration of the performance of the heat treatment process.

Second, to obtain the polyester fiber of the present invention
In the method of (1), the yarn is spun at a spinning speed of 1000 to 25000 m / min, heat treated at a temperature of 110 to 150 ° C. for 30 seconds or more to crystallize, and then stretched to 2.0 to 3.0 times again. This is a method of performing relaxation heat treatment as needed. Although this method has a drawback that it requires many steps and takes a lot of time for yarn making, it has an advantage that not only the extremely high dyeability which is the object of the present invention can be obtained but also the mechanical properties are improved. Also in this yarn making method, it is more preferable that the draft of spinning is high and the cooling rate is high.

The polyester fiber of the present invention may be used alone, but it is more preferable to use it by mixing it with a high shrinkage yarn by taking advantage of the characteristic of self-stretching at 95 ° C. In this case, in addition to the super-easy dyeability described above, a high bulky yarn can be obtained due to the difference in the yarn length from the shrinkage yarn.

The woven or knitted fabric obtained by using the polyester fiber of the present invention can be dyed at a high concentration with a basic dye in addition to the disperse dye. When dyeing with a disperse dye at a low temperature of 90 ° C. or less, it is more preferable to use a dye having a small molecular weight.

[0029]

The reason why the polyester fiber of the present invention can achieve the ultimate dyeability is considered as follows. That is, in the polyester fiber of the present invention, a phosphonium base [PR ₁ R ₂ R ₃ R ₄ ] having a considerably bulky volume is inserted between molecular chains, and as a result, the distance between adjacent molecular chains is widened. Therefore, the total molecular weight of R ₁ , R ₂ , R ₃ and R ₄ needs to be 60 or more. Further, the polyester fiber of the present invention has a lower molecular orientation and higher crystallinity than ordinary fibers. Since the above factors are synergistic, the dye molecules can be extremely easily diffused inside the fiber during the dyeing process.

However, it is customary that the dye is easy to be put in only by the above, but is easily discharged to the outside of the fiber at the same time. In other words, the retention of dye molecules is extremely low, and they easily fall off by washing with hot water. On the other hand, it is pointed out that the polyester fiber of the present invention does not shrink even at a low temperature of 95 ° C. and conversely extends. That is, due to the change in the fiber microstructure at this time, the dye molecules are firmly held between the fiber molecular chains, and the dyeing fastness can be maintained.

[0031]

The present invention will be described with reference to the following examples. The elongation rate defined here was measured using a thermomechanical analyzer TMA standard type manufactured by Rigaku Denki KK under a load of 0.015 g / de and a heating rate of 5 ° C / min.

100 parts of dimethyl terephthalate, 66 parts of ethylene glycol, tetrabutylphosphonium salt of 3,5-dicarboxybenzenesulfonic acid in the amount shown in Table 1 (varied in the range of 0 to 4.3 parts). The range of this amount is 0 to 3.5 mol% based on dimethyl terephthalate.
Corresponds to the range of. The total molecular weight of R ₁ , R ₂ , R ₃ and R ₄ is 228), manganese acetate tetrahydrate 0.03
Part (0.024 mol% relative to dimethyl terephthalate)
Was charged into a transesterification can, and the temperature was raised from 140 ° C. to 230 ° C. in a nitrogen gas atmosphere for 4 hours to distill off the produced methanol to cause a transesterification reaction. The product obtained was subsequently added with 0.03 of a 56% aqueous solution of orthophosphoric acid.
Part (0.033 mol% relative to dimethyl terephthalate)
And antimony trioxide 0.04 part (0.027 mol%)
Was added and transferred to a polymerization vessel. Then 760 over 1 hour
The pressure was reduced from mmHg to 1 mmHg, and simultaneously the temperature was raised from 230 ° C to 280 ° C over 1 hour and 30 minutes. Then, polymerization was carried out at a polymerization temperature of 280 ° C. under a reduced pressure of 1 mmHg or less.

The polyester obtained as described above was dried at 160 ° C. for 4 hours according to a conventional method, and then the pore size was reduced to 0.
Using a spinneret having 36 circular discharge holes of 60 mm, the spinneret was discharged in a molten state at a maximum temperature of 290 ° C., cooled and solidified by a conventional method, and then wound at a speed of 3000 m / min.

This polyester filament is then 2%
Was heat-treated by passing it through a slit heater heated to 220 ° C. at a speed of 400 m / min under the condition of over-feeding to obtain a multifilament of 75 de / 36 fil.

The polyester fiber obtained as described above is knitted, then scoured for 20 minutes at 60 ° C. using a score roll of 2 g / liter, and further dried and conditioned (20 ° C. × 20 ° C.).
65% RH), then disperse dye Sumikaron Navy Blue S-2GL 3% owf, bath ratio 1: 100 and atmospheric pressure 10
It was dyed at 0 ° C, 90 ° C and 80 ° C, respectively.

On the other hand, for the purpose of comparison, the copolymerization ratio of a normal polyester not copolymerized and 3,5-dicarboxybenzenesulfonic acid tetrabutylphosphonium salt is 1.
5 mol% of the above modified polyester was spun at a spinning speed of 1 according to a conventional method.
75d by spinning at 500 m / min, stretching 3.3 times and then heat treating with a slit heater 180 ° C
It was made a multifilament of e / 36fil.

These polyester yarns were also subjected to similar atmospheric dyeing and dyeing test at 130 ° C. using a high pressure dyeing machine.

Table 1 compares the birefringence Δn, density ρ, elongation at 95 ° C., and dyeing test results for the above polyester filaments. However, M in the table is 3,5
-Represents the copolymerization ratio (mol%) of tetrabutylphosphonium dicarboxybenzene sulfonate.

[0039]

[Table 1]

In Table 1, No. No. 1 is an example of unmodified polyester yarn, which is dyed well during high-pressure dyeing, but the dyeability at 100 ° C is one more step short. No.
In the case of 2, the same result is obtained because the degree of modification is low. On the other hand, No. 3 to No. No. 6 was the polyester fiber of the present invention, which had extremely high dyeability and had good dyeing fastness. Especially No. 4 to 6 can be dyed to some extent even at 80 ° C. No. 7 also has a high dyeing effect with a similar high dyeing performance, but copolymerization increases and Δn also decreases, resulting in a mechanical property of 1.2 g / de, which is not preferable in practice. In addition, there are disadvantages that the number of yarn breaks during spinning increases and the cost of modifying the polymer increases.

No. 9 is an example in which the modification of the polymer is carried out, but Δn, ρ and the elongation rate are different from those of the present invention.
In this case, although it is slightly darker than the ordinary polyester fiber (No. 8), it is insufficient for dyeing under normal pressure.

Claims (1)

[Claims] 1. The following general formula: [Wherein A is an aromatic group or an aliphatic group, X ₁ and X ₂ are the same or different ester-forming functional groups, n is a positive integer,
R ₁ , R ₂ , R ₃ and R ₄ are a hydrogen atom, an alkyl group,
The same or different groups selected from an aryl group and a hydroxyalkyl group and having a total molecular weight of R ₁ , R ₂ , R ₃ and R ₄ of 60 or more are shown. ] The phosphonium sulfonate represented by 0.5 mol% or more and 5.0
It is copolymerized at a ratio of not more than mol% and has an intrinsic viscosity of 0.
A polyester fiber mainly composed of polyethylene terephthalate of 5 or more and 0.7 or less and having a birefringence Δn of 0.0
A low-temperature dyeable polyester fiber having a density of 2 or more and 0.05 or less, a density ρ of 1.32 g / cm ³ or more and 1.35 g / cm ³ or less, and an elongation at 95 ° C. of 0% or more.