JPH0457917A - Polyester yarn having high strength and high dyeability - Google Patents

Abstract

PURPOSE:To obtain the title yarn having excellent normal-pressure dyeability with basic dye or disperse dye, strength and elongation characteristics, weather resistance, etc., comprising a polyester consisting essentially of ethylene terephthalate and containing a specific copolymerization component and satisfying a specific condition. CONSTITUTION:The objective yarn comprising a yarn which is composed of a polyester having >=80mol% repeating unit made of ethylene terephthalate prepared by copolymerizing a metal sulfonate group-containing isophthalic acid compound A with a straight-chain polyalkylene glycol B having 3-6 methyl groups in the repeating unit and satisfies a=1-3, 8/aXn/4<=b<=25/aXn/4 ((n) is number of methylene groups in repeating unit of polyalkylene glycol) when the amount of the component A copolymerized is a mol % and the amount of the component B copolymerized is bwt.%, >=4.5g/d strength T at break, >=0.150 double refraction n, <=15 % shrinkage percentage in boiling water, etc.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention can be dyed with basic dyes and disperse dyes at normal pressure, has a low alkali weight loss rate, and has excellent mechanical properties and chemical resistance. It relates to superior polyester fibers.

(Prior Art) Polyester fibers, typified by polyethylene terephthalate fibers, have excellent mechanical properties, chemical resistance, weather resistance, etc., and are widely used, including for clothing. However, as a disadvantage of polyester fiber.

Because of its strong molecular structure, it has poor dyeability, and furthermore, it cannot be dyed with ionic dyes such as basic dyes and acidic dyes, so it is difficult to obtain dyed products with bright colors. As an improved method, polyesters that can be dyed with basic dyes have been developed, which are copolymerized with compounds having metal salt sulfonate groups such as 5-sodium sulfoisophthalic acid.

If the dyeing property is not sufficient in normal pressure dyeing or if high dyeing property is to be obtained, a large amount must be copolymerized.

There was a problem that mechanical properties and chemical resistance deteriorated.

Many methods have been proposed to solve these problems, and one example is the 9-order method.

(a) A compound having a metal salt sulfonate group and a polyalkylene glycol compound are copolymerized into polyethylene terephthalate to enable dyeing with a basic dye at normal pressure (JP-A-57-117529).

No. 57-117530, No. 57-63325, No. 5
No. 7-210014, Special Publication No. 59-28672, No. 6
0-54430, etc.) (b) A method of spinning at high speed a polyester copolymerized with a compound having a metal salt sulfonate group (Japanese Patent Publication No. 10126/1982).

(C) A method of spinning polyester copolymerized with polyalkylene glycol at high speed to obtain easily dyeable fibers with 9 disperse dyes (Japanese Patent Publication No. 15725/1983) (d) Compounds in which alkylene oxide is added to bisphenols and metals Method of copolymerizing isophthalic acid having a salt sulfonate group (JP-A-57-121032) (e) Method of copolymerizing 5-sodium sulfoisophthalic acid and adipic acid (JP-A-61-34022) 5) - A method in which 1.0 to 2.5 mol% of sodium sulfoisophthalic acid and a long-chain compound having an ester bond-forming group are copolymerized, and the stretching temperature (hot plate temperature during stretching) and false-twisting temperature are regulated ( (Japanese Patent Publication No. 57-369) However, (a), (C), (In the case of Yama's method, by the copolymerized polyalkylene glycol component.

Weather resistance (light resistance) is poor and it cannot be used as a outer material.Alkali weight loss processing, which is carried out to improve texture and obtain a mild luster, has a high hydrolysis rate, so it is difficult to control it. Mixed fibers with polyester and other fibers,
Cross-knitting, etc. becomes difficult.

Next, in the case of method Q)), the dyeability is excellent because it uses a high-speed spinning method, but the mechanical properties of the fibers, especially the strength, are significantly reduced, and the unique excellent properties of polyester are lost. Furthermore, the cost of capital investment may be too high. Further, in the case of method (e), since adipic acid is used, there are drawbacks such as poor color tone of the polyester produced and poor physical properties depending on the amount of copolymerization. Additionally (for the Ω method.

Because the heat treatment temperature during stretching and the heater temperature during false twisting are low, sufficient heat setting is not possible, resulting in poor texture and poor recovery against force and heat after false twisting, and further adjustment of heat shrinkage rate. It has the disadvantage that it cannot be used for textiles where heat shrinkage is important because of its high heat shrinkage rate.

(Problem to be solved by the invention) The present invention is based on the excellent properties unique to polyester fiber.

In other words, the aim is to provide polyester fibers that can be dyed at normal pressure (around 100°C) with basic dyes and disperse dyes without impairing mechanical properties, weather resistance (light resistance), and appropriate alkali weight loss rate. be.

(Means for Solving the Problems) The present inventors have conducted intensive research to solve the above problems, and have obtained the following findings.

(i) Even if a compound having a metal salt sulfonate group that adsorbs basic dyes is copolymerized, the basic dyes will not be adsorbed as theoretically possible because the internal diffusion of the basic dyes will be hindered by the strong molecular structure of the polyester at normal pressure.

In order to achieve high dyeability, the molecular structure of polyester must be disturbed to make it easier for dyes to penetrate into the fibers.

(ii) Copolymerization of compounds with curved molecular structures will significantly reduce strength and elongation properties, so the amount of copolymerization of compounds such as 5-sodium sulfoisophthalate should be kept as small as possible to facilitate the penetration of the dye into the interior of the fibers. <Sh, linear copolymerization components with less deterioration of physical properties should be used, and the copolymerization amount of the component that makes it easier for the dye adsorbed on the 5-sodium sulfoisophthalate component to penetrate into the fibers should be adjusted to a specific ratio. There is a need.

(iii) When a compound having a metal salt sulfonate group and a polyalkylene glycol are copolymerized to make it easier for the basic dye to penetrate into the fiber, the weather resistance (light resistance) depends on the type and amount of copolymerization of the polyalkylene glycol. Since the weight loss rate of polyalkylene glycol and alkali varies greatly, it is necessary to specify the type of polyalkylene glycol and the amount of copolymerization.

(iv) As for the properties of drawn yarn suitable for textiles and false twisting, it is necessary to reduce heat shrinkage due to scouring and dyeing after weaving, and the boiling water shrinkage rate must be approximately 15% or less. In addition, for false-twisting, it is necessary to increase the heat treatment temperature during false-twisting in order to make the fibers bulky after false-twisting and to have excellent recovery properties. must be lowered. By lowering the heat shrinkage rate of the drawn yarn, a processed yarn with excellent shape stability can be obtained.

The present invention has been made based on such knowledge, and the gist thereof is as follows.

80 mol% or more of the repeating units are ethylene terephthalate, and isophthalic acid component A having metal salt sulfonate groups and linear polyalkylene glycol B having 3 to 6 methylene groups in the repeating units are copolymerized. Fibers made of polyester that meet the following 9 requirements [1] to [6]
A high-strength, highly dyeable polyester fiber that satisfies the following.

When the amount of copolymerization to (1) is a mol% and the amount of copolymerization of B is 5% by weight.

1.0≦a≦360 8/a×n/4≦b≦25/a×n/4 [n is the number of methylene groups in the repeating unit of polyalkylene glycol] ■Strength at cutting (T) 4. 5g/d or more ■Birefringence (Δn) 0.150 or more ■Boiling water shrinkage rate
15% or less■ Saturated dye adsorption capacity Dye is extracted with a solvent from 1 g of fibers whose dyeability with basic dyes has reached the saturated dye adsorption amount at 100°C.10.
The transmittance of the diluted solution is 30% or less at the maximum absorption wavelength of the dye.■ Use a 20% aqueous sodium hydroxide solution, and the bath ratio is 1:50. The alkali weight loss rate (V) when subjected to alkali treatment at a temperature of 70°C is ■≦2.5/rrf″o%/min CD o : Fineness of single yarn (denier)] The present invention will be described in detail below.

First, the amount of the isophthalic acid component A having a metal salt sulfonate group to be copolymerized into the polyester is suitably 1.0 to 3.0 mol % based on the acid component.

If it exceeds 3.0 mol %, the physical properties of the fibers will be markedly deteriorated, and furthermore, the alkali weight loss rate will be too high, reducing the range of use. Conversely, if it is less than 1.0 mol%, the dyeability with basic dyes will be insufficient.

Next, the most important requirements in the present invention are the type and copolymerization amount of polyalkylene glycol.

Using a linear polyalkylene glycol having 3 to 6 methylene groups constituting a repeating unit, copolymerizing the amount in a specific range determined in correlation with the amount of coelectricity of the isophthalic acid component having a metal salt sulfonate group. is necessary.

The number of ether bonds in the copolymerized polyester affects weather resistance (light resistance), and if the number of methylene groups in the repeating unit of polyalkylene glycol is small, the number of ether bonds increases, so it is necessary to reduce the amount added. Therefore, it is not possible to sufficiently improve dyeability. On the other hand, if the number of methylene groups is too large, the crystal structure of the polyester is disturbed too much, resulting in a decrease in strength. From this point of view, it is appropriate to use a polyalkylene glycol having 3 to 6 methylene groups in the repeating unit. Also 1
If a branched polyalkylene glycol is used, the crystal structure of the polyester is disturbed too much, resulting in a decrease in strength, so it is necessary to use a linear polyalkylene glycol.

The most preferred polyalkylene glycol is polytetramethylene glycol.

The amount of copolymerized polyalkylene glycol is related to the amount of isophthalic acid having a metal salt sulfonate group and the ether bonds constituting the polyester after copolymerization. Polyalkylene glycol is copolymerized to disturb the crystal structure of the isophthalic acid component, which has a metal salt sulfonate group, in order to make it easier for basic dyes to adsorb to the isophthalic acid component, which has a metal salt sulfonate group. amol%
.

When the amount of copolymerized polyalkylene glycol is 5% by weight, it is necessary to satisfy the linear equation.

8/a×n/4≦b≦25/a×n/4 [n is the number of methylene groups in the repeating unit of the polyalkylene glycol, and is 3 to 6. ] This means that if a is large, b can be reduced.

If b is large, a can be reduced, and if both of them are increased, the dyeability will be improved, but the strength and elongation properties will be poor, and if both of them are small, the opposite will occur.

The molecular weight of the polyalkylene glycol is not particularly limited, but if it is too small, the effect of improving dyeability will be poor, and if it is too large, it will cause a decrease in strength. The molecular weight is preferably approximately 400 to 15,000.

Next, the strength at cutting T is different from the cutting strength T (1, that is, the cutting strength divided by the fineness before the tensile test) obtained in a normal tensile test, and the elongation is E (%
), it has a linear relationship.

T=(1+E/100)TO Here, the meaning of the strength T during cutting will be explained.

For example, 1 normal cutting strength T. is 3.5g/d.

When the elongation E is 30%, T is 4.55 g/d. At this time, if T is constant and elongation is 20%, TO is 3.79
g/d, if the elongation is 40%, I To is 3.25 g/d
becomes. Depending on the setting of the stretching ratio, high strength results in low elongation, and low strength results in high elongation. In the case of the present invention, the elongation is suitably in the range of approximately 20 to 40%.

Cutting strength T at this time. There is no problem even if it has the range mentioned above, and it is a characteristic value as a thread.

In other words, the strength T at the time of cutting becomes more important. In addition, in the present invention, it is necessary for T to be 4.5 g/d or more, and if it is less than 4.5 g/d, thread breakage etc. will occur in post-processes such as weaving.

Furthermore, as described above, when the strength is reduced, the excellent properties of polyester fibers are lost.

Next is the birefringence Δn of the drawn yarn, which is 0, 15
It needs to be 0 or more. The excellent mechanical properties of polyester fibers are due to their high orientation compared to other fibers. *If the refractive index Δn is less than 0.150, the strength and elongation properties and initial elastic modulus will be poor. It ends up. usually,
In order to increase the birefringence Δn, the stretching ratio during stretching may be increased.

When copolymerizing a compound with a curved molecular structure such as 5-sodium sulfoisophthalic acid, if a high stretching ratio is used to achieve high orientation, the yarn may break or the residual elongation will be low. During post-processing, thread breakage and fluff are more likely to occur, causing trouble. Therefore, in the present invention, the amount of copolymerization of 5-sodium sulfoisophthalic acid, etc. is suppressed, and polyalkylene glycol having a linear molecular structure is copolymerized, so that basic dyes can easily penetrate into the fibers and are highly oriented. It is the thread of the thread.

Next is the diving shrinkage rate, which needs to be 15% or less. As mentioned above, if the flood shrinkage rate exceeds 15%, when used for textiles, the shrinkage becomes large during the scouring and dyeing processes after weaving, making it unsuitable. Furthermore, when used for processing systems, the shape of the processed yarn It is not possible to increase the heat treatment temperature during false twisting to increase stability. If the heat treatment temperature during false twisting is increased in a region where the flood shrinkage rate of the drawn yarn exceeds 15%, untwisting or yarn breakage will occur frequently, and the texture of the processed yarn will be poor.

Therefore, the flood shrinkage rate of the drawn yarn should be 15% or less.

When performing false twisting, it is necessary to increase the heat treatment temperature during false twisting.

Next is the dye adsorption capacity of basic dyes, which is 100
The saturated dye adsorption capacity in normal pressure dyeing at ℃ must satisfy the following conditions. That is, the dye is extracted with a solvent from 1 g of dyed material that has reached the saturated dye adsorption amount, and 10100O
It is necessary that the transmittance of the diluted solution is 30% or less at the maximum absorption wavelength of the dye. When this transmittance exceeds 30%, less dye is adsorbed to the fibers, and it cannot be said that the dyeing properties at normal pressure are excellent. Note that the saturated dye adsorption amount is the amount of dye adsorption that no longer adsorbs dye even if the dye concentration and dyeing time are increased, and the permeability of a solution obtained by diluting the dye extracted from dyed fibers to a certain amount is If there is no change, it can be said that the saturated dye adsorption amount has been reached. According to experiments by the present inventors, when dyeing with a normal basic dye at normal pressure and 100° C., a saturated dye adsorption amount is reached if the dye concentration is 20% OWF and the dyeing time is 60 minutes.

Next is the alkali weight loss rate, which is related to the surface area of the fibers; if the total fineness is constant, the speed will be lower if the single yarn fineness D0 is large, and conversely, the speed will be smaller depending on the single yarn fineness. The smaller the value, the greater the speed. Therefore, the alkali weight loss rate is inversely proportional to the square root of the single filament fineness.The alkali weight loss rate in the present invention is as follows:
It is necessary that the alkali weight loss rate V when subjected to alkali treatment at a bath ratio of 1:50° and a temperature of 70°C satisfies the following formula.

■≦2.5/7 work τ%/min If this exceeds this, the alkali weight loss rate will be too different from that of polyethylene terephthalate, and it will be mixed or knitted with polyethylene terephthalate fibers, or even mixed with other fibers or knitted. becomes difficult.

Finally, regarding the spinning and drawing conditions for producing the polyester fiber of the present invention, it is desirable that the spinning speed be 1000 m/min or more and the heat treatment temperature during drawing be 150° C. or more. If the spinning speed is less than 1000 rn/min, the drawability will be poor and the heat treatment temperature during drawing to suppress the heat shrinkage rate cannot be increased.

Furthermore, thread breakage and single thread breakage occur frequently. Also.

Although stretching is possible even if the heat treatment temperature during stretching is low,
If the heat treatment temperature during stretching is low, the heat shrinkage rate will be high, and as mentioned above, it may not be possible to use it as yarn for textiles, or when it is used for false twisting, it is not possible to increase the heat treatment temperature in the false twisting process. .

The resulting processed yarn has poor shape stability. Further, when the drawn yarn is subjected to false twist processing, the heat treatment temperature is preferably 160° C. or higher.

If the heat treatment temperature during false twisting is low, the shape stability will be poor as described above.

Note that the polyester fiber of the present invention may be made into a different shrinkage blend yarn or a different shrinkage blend yarn, or may be inter-knitted or inter-woven with other fibers (especially wool or silk).

(Example) Next, the present invention will be explained by way of examples.

Note that the characteristic values in one example were measured by the following method.

Intrinsic viscosity [η] Using a mixed solvent of equal amounts of phenol and tetrachloroethane,
Measured at 20°C.

Strength and elongation characteristics Tensilon tlTM-4-100 manufactured by Orientic Co., Ltd.
The measurement was carried out using a mold with a sample length of 50 cm and a tensile speed of 50 cm/min.

Alkali weight loss rate 20% sodium hydroxide aqueous solution, bath ratio 1:50
．． The weight loss rate was determined by processing at a temperature of 70°C for 15 minutes.

The weight loss rate was divided by 15 and calculated.

Boiling water shrinkage rate Using an ε meter manufactured by Toyobo Engineering Co., Ltd.

Sample length 50cm, processing temperature 98℃, load 0.001g
/d.

Measurement was performed with a processing time of 10 seconds.

Saturated dye adsorption capacity The drawn yarn was knitted into a tube and dyed under the following conditions.

Basic dye 20%owf acetic acid 0.2mi! / l Sodium acetate 0.2g/ji! Bath ratio: 1:50 Temperature: 100°C Dyeing time: 60 minutes After dyeing, 1 g of tubular knitted fabric was taken, and the dye was extracted using 50 rnl of dimethylformamide at 60°C, and diluted to 1000 mL with water. The transmittance of this liquid was measured using a spectrophotometer model BPS-3T manufactured by Hitachi, Ltd. at the maximum absorption wavelength of the dye used.

Birefringence Δn Measured using white light using a Nikon P-shaped polarizing microscope.

Light fastness The drawn yarn was dyed in a tube, and then treated using a carbon arc fade meter manufactured by Zenben Kagaku Co., Ltd. under the following conditions, and the degree of discoloration was visually determined.

Arc voltage 130V Current 16A In-flight temperature: 63℃ Processing time: 40 hours Elongation rate and elastic modulus of processed yarn It was measured according to the JIS L 1077 method.

Examples 1 to 3 and Comparative Examples 1 to 4 The intrinsic viscosity [η] of copolymerized compounds shown in Table 1 containing terephthalic acid and ethylene glycol as main components was 0.
70 polyesters were prepared.

5-5SIP: 5-sodium sulfoisophthalate PTMG: 1-lihexamethene glycol (
Molecule 11l10000) PT: polytetramethylene glycol (molecular weight 5000) PBG: jt triethylene glycol (molecular weight 1000) After drying these polyesters under reduced pressure by a conventional method, 9 using a conventional spinning device, Examples 1 to 3 and Comparative Examples 1 to 3 are spinning speeds of 14
Comparative Example 4 was spun at a spinning speed of 6000 m/min. In addition, at this time, the brand after stretching is 75 d/3
The discharge amount was corrected to be 6f. However, comparative example 4
The discharge amount was corrected so that the brand after spinning was 75d/36f.

The obtained undrawn yarn was drawn at the draw ratio (DR) shown in Table 2 so that the residual elongation was about 30%, other conditions being the same.
Stretching was carried out at a preheating roller temperature of 70°C and a heat treatment plate temperature of 165°C (comparative example 4 was not stretched).

did.

After drying the dyed tubular knitted fabric, the saturated dye adsorption capacity (permeability) was measured.

The results are shown in Table 4.

Sl. . : Boiling water shrinkage rate These drawn yarns were knitted into tubes and dyed using the basic dye shown in Table 3 under the conditions for measuring saturated dye adsorption capacity. The tubular knitted fabric was dyed under the same conditions as the conditions for measuring saturated dye adsorption ability, except that the dyestuff was 2% owf, and the light fastness was measured.

In addition, the tubular knitted fabric was subjected to alkali weight loss treatment, and the weight loss rate was calculated.

These results are shown in Table 5.

Light fastness (grade): Small discoloration 1 to 5 Discoloration large Next, these threads are warped, glued, and made into warp threads, 75 d
/36f polyethylene terephthalate yarn as weft,
Weaving was carried out using a water jet loom model 2N-303 manufactured by Tsudakoma Co., Ltd. at a speed of 500 rpm.

Table 6 shows the conditions during weaving and the condition of the fabrics that were dyed with a basic dye (Yomesha 4 in Table 3) after the fabrics were subjected to alkali weight loss processing (20% weight loss on average).

The condition of the fabric is determined by visual inspection in three stages: ○: Uniform Δ: Fuzz is visible on the surface of the fabric In contrast, the fibers of the present invention are excellent in all aspects of dyeability with basic dyes, light resistance, weavability, and the condition of the fabric after dyeing. It can be seen that it is inferior in any of the above items.

Example 4 and Comparative Example 5 The polyester of Example 2 was dried under reduced pressure using a conventional method.
A triangular cross-section yarn was spun in 7 minutes. In addition.

At this time, the discharge amount was adjusted so that the fineness after stretching was 50 d.

This undrawn yarn was drawn using a conventional drawing machine under the drawing conditions shown in Table 7, and the performance of the obtained drawn yarn is shown in Table 8.

Table 8 Table 9 The birefringence Δn was measured by manufacturing round cross-section yarns under the same conditions.

Next, using this drawn yarn, the spindle rotation speed was 335.00 Orpm, the number of twists was 3.6507/M, the overfeed rate was 2%, and the speed was 9 using a Mitsubishi Heavy Industries LS-6 plate twisting machine.
False twisting was performed at a speed of 0 m/min. The heater temperature was 200°C for Example 4 and 1 for Comparative Example 5.
Two conditions were used: 40°C and 200°C.

Table 9 shows the performance of the obtained processed yarn. In addition.

Texture and luster (silky tone) are achieved by tube knitting processed yarn.

Visual evaluation was performed in three stages: ◯ (good), △, and X (poor).

As is clear from Table 9, the processed yarn made of the fibers of the present invention has excellent elasticity, does not cause untwisting, and provides a fabric with excellent texture and gloss.

(Effects of the Invention) According to the present invention, it has excellent atmospheric dyeability with basic dyes and disperse dyes, excellent weather resistance, and almost no trouble in post-processes such as weaving and false twisting.

A polyester fiber with excellent performance is provided.

Patent applicant: Nihon Ester Co., Ltd.

Claims (1)

[Scope of Claims] [1] 80 mol% or more of the repeating units are ethylene terephthalate, and the isophthalic acid component A having a metal salt sulfonate group and the number of methylene groups in the repeating units are 3 to 3.
A fiber made of polyester copolymerized with linear polyalkylene glycol B of No. 6, which meets the following requirements [1]
A high-strength, highly dyeable polyester fiber characterized by satisfying ~[6]. (1) When the copolymerization amount of A is a mol% and the copolymerization amount of B is b weight%, 1.0≦a≦3.0 8/a×n/4≦b≦25/a×n /4 [n is the number of methylene groups in the repeating unit of polyalkylene glycol] (2) Strength at cutting (T) 4.5 g/d or more (3) Birefringence (Δn) 0.150 or more (4) Boiling water shrinkage rate 15% or less (5) Saturated dye adsorption capacity Dye is extracted with a solvent from 1 g of fiber whose dyeability with basic dyes has reached the amount of saturated dye adsorption at 100°C.
The transmittance of the diluted solution is 30% or less at the maximum absorption wavelength of the dye (6) Use a 20% aqueous sodium hydroxide solution, and the bath ratio is 1
: 50, the alkali weight loss rate (V) when treated with alkali at a temperature of 70°C is V≦2.5/√D_0%/min [D_0: Fineness (denier) of single yarn] [2] Polyalkylene glycol is polytetra The high-strength and highly dyeable polyester fiber according to claim 1, which is methylene glycol.