JPH02210023A - Polyester conjugate crimped yarn - Google Patents

Abstract

PURPOSE:To obtain the title crimped yarn excellent in water absorptivity and hygroscopicity by making a conjugate spinning of dense component consisting of polybutylene terephthalate and finely porous component consisting of a specific polyester at a specified ratio in a side-by-side manner. CONSTITUTION:The objective crimped yarn having stretchable performance and special fine pores, comprised of hollow fiber, which can be obtained by conjugate spinning, in a side-by-side manner, of (A) dense component consisting of polybutylene terephthalate with butylene terephthalate unit accounting for >=80mol% of recurring unit and (B) finely porous component consisting of a polyester <=0.55 in intrinsic viscosity with ethylene terephthalate accounting for >=80mol% of recurring unit at the weight ratio A/B=(30:70)-(70:30). This crimped yarn gives a crimp rate (TC2) of >=7% when subjected to boiling water treatment under a load of 2mg/d.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a hollow crimped yarn. More specifically, the present invention relates to a polyester hollow composite crimped yarn that has stretchability, has special micropores, and has excellent water absorption and hygroscopicity.

<Prior Art> Polyester has many excellent properties and therefore has an extremely wide range of uses as a synthetic fiber. However, in recent years, there has been an increasing demand for the functionality of woven fabrics, especially elasticity and water absorption.

There is an increasing demand for materials that simultaneously satisfy moisture absorption properties.

Conventionally, methods for imparting water absorbency and hygroscopicity to polyester fibers include methods of blending hydrophilic compounds into polymers before being molded into fibers, and polyester II! A method has also been proposed in which J fibers are treated with an alkaline aqueous solution to form wrinkle-like micropores arranged in the fiber axis direction on the fiber surface.
All of the fibers produced by these methods had insufficient water absorption or a large decrease in strength, and were not suitable for practical use.

To improve this drawback, we can produce hollow fibers by melt-spinning polyester into polyester fibers that are sufficiently superior in water absorption, hygroscopicity, and durability, and have sufficiently low strength deterioration, and are fibrillated and durable. In this process, a special organic sulfonic acid compound is added, and the resulting hollow fibers are treated with an aqueous solution of an alkali compound to form micropores that are at least partially connected to the hollow part. (Japanese Patent Publication No. 61-31231), this fiber exhibits excellent water absorption and hygroscopicity, but when it is subjected to false twist crimp processing to give it further elasticity, hollow collapse occurs and the water absorption and hygroscopic properties are reduced. There was a problem in that the hygroscopicity was significantly reduced.

(Problems to be Solved by the Invention) The present inventors have arrived at the present invention as a result of intensive research in order to solve the above-mentioned problems and provide a fiber that simultaneously satisfies stretchability, permanent water absorption, and hygroscopicity. This is what I did.

(Means for Solving the Problems) The present inventors focused on the characteristics of polybutylene terephthalate, which shows little deterioration in physical properties against alkali 7A41 and easily exhibits crimp performance without undergoing false twisting and crimp processing, and By disposing it as one component of hollow side-by-side fibers, it imparts elasticity without the need for false twisting and crimp processing, and is a composite material with excellent water absorption and hygroscopicity (hereinafter sometimes referred to as water absorption and hygroscopicity). The present invention was achieved by discovering that crimped yarn can be obtained.

That is, in the present invention, the solid component A made of polybutylene terephthalate and the microporous component B made of polyester having an intrinsic viscosity of 0.55 or less are in a weight ratio of 30:70:30.
Hollow fibers are composited side-by-side at a ratio of 7% when treated with spring water under a load of 2mg/de.
This is a polyester composite crimped yarn characterized by exhibiting the above crimp rate (TC2).

In the present invention, component A, which has polybutylene terephthalate-1 as a solid component, is composed of 80 mol% or more, preferably 90 mol% or more of repeating units of butylene terephthalate units, and does not have a substantially porous structure. There are no (fulfilling) ingredients.

Here, if the butylene terephthalate unit content is less than 80 mol %, the stretching performance targeted by the present invention cannot be obtained. and 20 mol% for polybutylene terephthalate.
Hereinafter, a third component such as isophthalic acid or phthalic acid is preferably used in a proportion of 10 mol% or less.

Dicarboxylic acids such as methyl terephthalic acid and adipic acid, and diglycols such as ethylene glycol, trimethylene glycol and neopentyl glycol may be copolymerized, and a small amount of other polymers or titanium oxide 9 calcium carbonate, etc. may be copolymerized. It may also contain matting agents and other known additives.

On the other hand, in component B, 80 mol% or more, preferably 90 mol% or more of the repeating units must be composed of ethylene terephthalate.

Here, if the ethylene terephthalate unit content is less than 80 mol %, the washing resistance, weather resistance, etc. inherent in polyester as a dyed product deteriorates, which is not preferable.

The cross section of the composite crimped yarn of the present invention comprising the above-mentioned A and B components is shown, for example, in FIGS. 1 to 4, but there is no particular restriction on its external shape. On the other hand, B is a microporous component, that is, a component in which micropores exist over the entire cross section. Taking into consideration, A:B=30:70-70:3
The range is 0.

The micropores preferably have a diameter of o, ooi ~ 5 μm,
The length is 50 times or less the diameter, the pores are arranged in the fiber axis direction, are scattered over the entire surface of the porous component of the cross section of the tm fiber, and at least a part of the pores communicates with the hollow part.

By the way, in the present invention, in order to obtain a cotton yarn that exhibits a TC of 7% or more when subjected to spring water treatment under a load of 2[/de], it is important to use the B component consisting of polyethylene terephthalate. The intrinsic viscosity [η] (that is, the intrinsic viscosity of m fibers) must be 0.55 or less.

When this value is larger than 0.55, a composite yarn with a high crimp rate cannot be obtained.On the other hand, there is no particular restriction on the lower limit of [η]B, but approximately 0.3 is usually appropriate.

In contrast, A made of polybutylene terephthalate
The intrinsic viscosity [η]A of the component (that is, the intrinsic viscosity of the fiber) is not particularly limited, but when composite spinning is performed with component B consisting of polyethylene terephthalate, the molecular orientation of component A polybutylene terephthalate degree is B
The degree of molecular orientation is higher than that of the component polyethylene terephthalate-1, and the mechanical properties such as crimp expansion and contraction after stretching are largely influenced by the properties of component A consisting of polybutylene terephthalate. In order to maintain the mechanical function of the composite crimped yarn weaving or fabric, the intrinsic viscosity [η]A of the A component is preferably 0.7 or more, more preferably 0.8 or more.

On the other hand, there is no particular restriction on the upper limit, but about 1.5 is appropriate from the viewpoint of silk-spinning properties and the like.

In addition, regarding the hollowness ratio of hollow composite fibers, if this value is too low, water absorption due to hollow composite fibers will decrease.

On the other hand, if the hygroscopicity is too high, the hollow part becomes easy to collapse, and once it collapses, water absorption and hygroscopicity decrease, so the hollowness ratio, that is, the hollowness relative to the apparent cross-section of the fiber, The proportion of the cross section of the part is preferably in the range of 5 to 50%.

Next, a method for manufacturing the hollow composite fiber of the present invention will be described.

First, composite spinning is performed to form a side-by-side type hollow fiber specified as solid/component A consisting of polybutylene terephthalate. At that time, a conventionally known spinneret, for example,
-19108 and Japanese Patent Publication No. 41-16125. In particular, as described in Japanese Utility Model Publication No. 42-19536, both component polymers immediately after being discharged can be melt-spun. If a spinneret is used that is joined to form a hollow portion directly below the spinneret, stable spinning can be achieved.

That is, when polymers with different melt flow viscosities are extruded from the same hole at the same discharge ratio, the polymer with a lower flow viscosity will have a higher discharge linear velocity than the polymer with a higher flow viscosity.
Immediately after discharge, the discharged composite yarn bends and adheres to the spinneret surface, a so-called kneeling phenomenon, which causes a decrease in spinning stability.

However, if the die described in Japanese Utility Model Publication No. 42-19536 is used, even if the melt flow viscosity of each discharged polymer is different, the speed during compounding will be almost the same.
Stable spinning is possible without any kneeling phenomenon.

As mentioned above, the weight ratio of component A consisting of polybutylene terephthalate to component B consisting of polyethylene terephthalate in a composite yarn of component B, that is, the discharge ratio of both components A and B, is determined based on physical properties, stretching performance, water absorption/moisture absorption performance, and spinning stability. Considering that, the A component ratio is 30 to 70%, and the B component ratio is 70%.
The ratio may be set to ~30%.

What is important in expressing the stretchability of the polyester composite #@shrinkage east of the present invention is the intrinsic viscosity [η]B of the B component made of polyethylene terephthalate, which needs to be 0.55 or less. Considering the decrease in [η] under the spinning conditions, a polymer with [η] slightly higher than the desired Uη3B is selected.

This also applies to polybutylene terephthalate.

Next, the yarn that has not been composite spun is cooled with a cooling fluid, and then subjected to spring water treatment by spinning under the following conditions.
It exhibits a desirable crimp and does not require false twist crimp processing.
It becomes a moisture-absorbing fiber with stretch properties. That is, regarding the take-up speed Vo (m/min) of the spun yarn, 150
After taking it through the 10th la at a speed higher than 0 m/min and continuously stretching it at a stretching ratio that satisfies the formula <:DR-1<3 V o -1500, the 20th la (G
After heat setting at 100 to 200°C in R2), the 20th
Between -A and 30th -A, O, -B feed rate (OF)
((FR3 speed/GR2 speed - 1) X1001 is 0
．． After setting the GRl speed to 5 to 4% and performing air entanglement treatment between these four points, #! This is the way to take it.

If the conditions are outside this range, the crimp performance is insufficient or a certain amount cannot be wound continuously, and it is not possible to obtain fibers that are not only stretchable but also hygroscopically and water-absorbing.

If the hollowness ratio of the hollow composite fiber obtained in this way is too low, the effect of improving water absorption and hygroscopicity by making it hollow will decrease, and if it is too high, the hollow part will be easily crushed; Therefore, the hollow ratio, that is, the ratio of the cross section of the hollow portion to the apparent cross section of the fiber, is preferably in the range of 5 to 50%.

Here, we will explain the microporous component B. Generally, this is a fiber made of a composition in which an unmodified polyester contains an organic sulfonic acid compound, preferably an organic sulfonic acid compound having an ester-forming functional group, and is treated with an alkali. to remove the organic sulfonic acid compound.

In this case, there are two compositions. One is a substantial blend of organic sulfonic acid compounds with unmodified polyester (
The other is a composition in which a modified polyester copolymerized with an organic sulfonic acid compound is blended (dispersed) into an unmodified polyester. In the latter case, the modified polyester is removed by alkali treatment.

The sulfonic acid compound used in the present invention is, for example, one represented by the following general formula %. ．． Co 1/2 or Zn 1/2 is preferred, especially Li, Na, and K.

Ca1/2. Mg1/2 is particularly preferable, and Ml is particularly preferably an alkali metal or alkaline earth metal, and among them, Li, Na, and Cat/2°Mg1/2 are particularly preferable.Mn and Ml may be the same or different. , n is 1 or 2.

Y is a hydrogen atom or an ester-forming functional group. 〇 (CHz) 1 inch-0H (where 1 is an integer of 2 or more, p is an integer of 1 or more), etc. are preferred.

Preferred specific examples of such sulfonic acid metal salt compounds include 3-carbomethoxybenzenesulfonic acid Na-5
-Carboxylic acid Na, 3-carbomethoxy benzenesulfonic acid Na-5-carboxylic acid K, 3-carbomethoxy
Benzenesulfonic acid, -5-carboxylic acid, 3-hydroxyethoxycarbonyl benzenesulfonic acid Na-5
-Sodium carboxylate, Na 3-carboxy benzenesulfonate, Na 5-carboxylate, 3-hydroxyethoxycarbonyl benzenesulfone'#! 1Na5-carboxylic acid Mg1/2. Examples include Na-benzenesulfonic acid Na-3,5-dicarboxylic acid Na-benzenesulfonic acid Na-3,5-dicarboxylic acid M g 1/2.

In addition, as other organic sulfonic acid compounds, those represented by the following general formula % are preferred.In formula 6, Z represents only 3 aromatic groups or aliphatic hydrocarbon groups; Preferably, 0M represents a metal or hydrogen atom, and an alkali metal is particularly preferred. R1 represents an ester-forming functional group, and a preferred specific example is OO-C[0(CH2)J]m0H1I (CHz OHl-O -+CH2sun"r-t O (CH2s7sm OH
(However, R is a lower alkyl group or a phenyl group, 9 is an integer of 2 or more, m is an integer of 0 or 1 or more, and n is an integer of 1 or more).

R2 represents an ester-forming functional group or a hydrogen atom that is the same as or different from R1, and is preferably an ester-forming functional group. A preferred specific example of such an organic sulfonic acid compound is 3,5-di(carboxylic acid). Sodium (or potassium) methoxy)benzenesulfonate, 1.
Examples include sodium (or potassium) 8-di(carbomethoxy)naphthalene-3-sulfonate and sodium (or potassium) 2,5-bis(hydroxyethoxy)benzenesulfonate.

In order to produce a modified polyester copolymerized with an organic sulfonic acid compound, a predetermined amount of the organic sulfonic acid compound may be added at any stage, preferably before the completion of the first stage reaction. If the amount of the sulfonic acid compound added is too small, the water absorption and hygroscopicity of the final composite hollow fiber will be insufficient; on the other hand, if it is too large, it will be difficult to synthesize modified polyester, or it will be difficult to make fibers such as spinning. Since troubles are likely to occur during the process, 2%
A range of 16 mol% to 16 mol% is preferable.

The modified polyester thus obtained is blended with unmodified polyester to form a mixed polyester.

Any method may be used to mix the modified polyester and unmodified polyester, but if a partition reaction occurs between the modified polyester and unmodified polyester, the resulting composite hollow fibers will contain The diameter of the pores becomes small, and in extreme cases, that is, when the partition reaction progresses completely, no pores are formed. Therefore, it is preferable to avoid partition reaction between modified polyester and unmodified polyester as much as possible, although it may occur to some extent.

Preferred blending methods include, for example: (1) A method in which modified polyester and unmodified polyester are mixed in the form of powder at both ends, and the mixture is supplied to the spinning process either as is or after being formed into a stubble. (2) At the end of polymerization? Unmodified (or modified) in J melt state
A method of adding modified (or unmodified) polyester to polyester, melt-mixing it, and supplying it to the spinning process either as it is or after it is turned into a tube. ■ Modified polyester and unmodified polyester are combined in a molten state to form a static Examples include a method of mixing with a mixer, an extrusion screw, etc., and supplying the mixture to the spinning process as it is or after forming it into a chip.

The amount of modified polyester added to unmodified polyester is
If the amount is too low, the water absorption and hygroscopicity of the composite hollow fiber obtained will be insufficient, and if the amount is too high, the strength will be significantly reduced due to treatment with an aqueous solution of an alkali compound after spinning. 5-1
The polyester component serving as the base of the modified polyester and the unmodified polyester may be the same or different, and the modified polyester and the unmodified polyester may have different degrees of polymerization. May be the same or different.

The cross section of the hollow composite fiber obtained as described above must have a constant hollowness ratio, the polyethylene terephthalate component reaches from the fiber surface to the hollow part, and if it is composited side-by-side, its external shape etc. There is no need to specifically limit this.

Micropores can be formed by removing a portion of the modified polyester containing a specific sulfonic acid compound in component B of the hollow composite. For this purpose, the fibers in the form of yarn or fabric are immersed in an aqueous solution of an alkaline compound.

The alkaline compounds used here include sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, and sodium carbonate.

Examples include potassium carbonate. Among them, sodium hydroxide and potassium hydroxide are particularly preferable.The concentration of the aqueous solution of the alkali compound depends on the type of the alkali compound,
Although it varies depending on the processing conditions etc., the range of 0.01 to 40% by weight is generally preferable, and the range of 1 to 30% by weight is particularly preferable. The processing temperature is preferably in the range of room temperature to 100°C. The processing time is 1 minute. It is sufficient if it is within the range of ~4 hours, and
The amount of modified polyester eluted and removed by treatment with this aqueous solution of an alkali compound is appropriately adjusted to a range of 2 to 50% by weight based on the weight of component B in the fiber.

By treating with an aqueous solution of an alkaline compound in this way, the B component of the hollow composite fiber is scattered over the cross section,
IIa W1 pores are formed which are arranged in the fiber axis direction and at least a part of which communicates with the hollow part, approximately 0.01 to 3 μm in diameter and 50 times the length or less of the diameter, resulting in excellent water absorption.・
Becomes hygroscopic.

Moreover, since polybutylene terephthalate is used as one of the side-by-side components, crimping occurs and elasticity is exhibited, and at the same time, strength decrease due to alkali weight loss and fibril resistance are improved.

Note that the hollow composite fiber obtained by the method of the present invention includes:
Optional additives as required, such as catalysts.

A coloring inhibitor, N (thermal agent, lfC fuel agent, optical brightener, matting agent 1 coloring agent, inorganic fine particles, etc.) may be included.

(Effects of the Invention) According to the present invention, the presence of hollow portions, which are essential for improving water absorption and hygroscopicity, and the hollow holes are crushed during the false twisting and crimp processing process for imparting elasticity, resulting in less elasticity. The trade-off of water absorption and hygroscopicity being sacrificed in return for provision is resolved. That is, by selecting the solid component A and the microporous component B, specifying their composite ratio, and [η] of the B component,
Even if it is raw silk, a hollow conjugate fiber exhibiting sufficient neutral a capacity can be realized.

Incidentally, preferred embodiments of the hollow fiber of the present invention and a method for producing the same are as follows.

1 Ritsuhuangai a, the micropores in the porous component have a diameter of 0.001 to 5
μm, the length is 50 times or less the diameter, arranged in the fiber axis direction, scattered over the entire surface of the porous component of the cross section of the fiber, and at least a part of which communicates with the hollow part.

b. fl+tl[l pores in which the micropores are formed by removing at least a portion of the sulfonic acid compound represented by the following general formula % from an unmodified polyester in which the sulfonic acid compound is substantially dispersed; To be.

In the above formula, Ml is a metal, and Ml is particularly an alkali metal, an alkaline earth metal, 1Mn 1/2. Co
1/2 or Z n 1/2 is preferable, especially L
i, Na, Cal/2. Mg1/2 is particularly preferred, and Ml is particularly preferably an alkali metal or alkaline earth metal, especially Li, Na, Cal/2. M
gl/2 is particularly preferred; Ml and Ml may be the same or different; n is 1 or 2; Y is a hydrogen atom or an ester-forming functional group, and the functional group is 100OR'' (wherein, Rm is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group) or -〇〇+O (CH2 )
x--OH (where 1 is an integer of 2 or more, p is an integer of 1 or more), etc. are preferred.

C, @pores remove at least a portion of the modified polyester copolymerized with an organic sulfonic acid compound represented by the following general formula % from a composition in which the modified polyester is previously dispersed in component B. g & pores formed by

The enriched component A is a polymer in which 80 mol% or more of the repeating units are butylene terephthalate, and the B component is composed of an unmodified polyester in which an organic sulfonic acid compound represented by the general formula % is dispersed. Intrinsic viscosity of component B [η
] After spinning side-by-side hollow composite fibers under the following conditions so that B is 0.55 or less, Vo > 1500 m 7 minutes < DR-1 < 3 Vo -1500 GR, temperature; 100-200°C GR, ~ GR, overfeed rate: 0.5 to 4% By treating with an aqueous solution of an alkali compound to remove at least a part of the organic sulfonic acid compound in component B of the composite crimped yarn, the diameter is reduced to 0.001%. Forms micropores that are ~5 μm in length and 50 times or less the diameter, arranged in the fiber axis direction, scattered over the entire porous component of the cross section of the fiber, and at least a part of which communicates with the hollow part. thing.

The present invention will be further explained below with reference to Examples.

In the examples, "parts" indicate parts by weight, and the physical properties of the hollow fibers obtained were measured by the following methods.

(+) Crimp rate T Cz when subjected to boiling water treatment under a load of 2 parts g/de A tension of 50 cm/de is applied to the sample and the sample is wound into a skein approximately 3
Make a 000de skein. After creating the skein, place 2 on one end of the skein.
Applying a load of 00■/de, the length fo after 1 minute has elapsed
(am) 6 Then remove the load of 200 ■/de and heat to 100℃ with a load of 2 R/de applied.
Treat in spring water for 20 minutes.

Immediately after the boiling water treatment, the entire load is removed and allowed to air dry in a free state for 24 hours. 2 #/again on the air-dried sample
Apply a load of de+ 20OR/de, and the length after 1 minute has passed is 11. (■) 1 then 200 v
Remove the load on sx/de and the length after 1 minute has passed!
2 is measured and the crimp rate TC2 is calculated using the following formula.

! > 1z Te3 (%) = x100! 0 (6) Intrinsic viscosity [η]A of the A component and B component of the spun thread
[η]B Measurements were made using a 35° C. solution of orthochlorophenol for samples in which each component was separately discharged under the same spinning conditions as the composite spinning conditions.

(To) Water absorption rate test method (according to J I 5-L1018) The fibers are made into a cloth, and this cloth is washed with anionic detergent Zab (
Repeat this process a predetermined number of times with a 0.3% aqueous solution of Kao Soap Co., Ltd. at 40°C for 30 minutes in a household electric washing machine, then dry the resulting sample horizontally and place it from a height of 1 cm above the sample. One drop of water (0.04c, c) is dropped, and the time until the water is completely absorbed by the sample and no reflected light is observed is measured.

(c) Water Absorption Measuring Method A sample obtained by drying a fabric is immersed in water for 30 minutes or more, and then dehydrated for 5 minutes in a dehydrator of a household electric washing machine. It was calculated from the weight of the dry sample and the weight of the sample after dehydration using the following formula.

Water absorption rate = (Sample weight after dehydration - Dry sample weight) / Dry sample weight (%) (ν) Strength reduction rate due to alkali treatment Strength of fiber obtained by unwinding the fabric before alkali treatment and after alkali treatment The strength of the fibers obtained by unraveling the fabrics was compared.

&D Using a Gakushin type flat abrasion machine for fibril resistance abrasion fastness testing, using a georgette made of 100% polyethylene terephthalate as the friction cloth, the test cloth was abraded a specified number of times under a load of 500 tons. Check for the occurrence of fibrillation.

Examples and Comparative Examples Containing 0.3% by weight of titanium oxide [η]A=0.9
The polybutylene terephthalate containing 0.3% by weight of titanium oxide [η coA = 0.64 as component A, and the sulfonic acid compound 3-carbomethoxybenzenesulfone Contains 1.3 mol% of Na acid-5-carboxylic acid based on dimethyl terephthalate [η] B = 0.64. Either of two types of polyethylene terephthalate of 0.45 is used as the B component, and a composite spinning agent is used. A from the mouthpiece with a 24H hollow discharge hole,
Discharge spinning speed 2500 with discharge ratio of B component 50:50
After drawing at a speed of m/min and continuously drawing at 4500 m/min, a composite fiber of 75 de/24 filament with a hollowness ratio of 8% was obtained. This multifilament was knitted into a knitted fabric, scoured by a conventional method, dried, and then treated with a 1% aqueous solution of caustic soda at submersion temperature for 120 minutes.

The water absorption rate, water absorption rate, crimp rate and strength reduction rate after alkali treatment of this fabric were as shown in Table 1.

In addition, microscopic observation of these fabrics after 200 abrasions revealed that no fibrillation was observed.

Table PBT = polybutylene terephthalate [η] A = 0.8
f3PET=polyethylene terephthalate [η]A=0
．． 61

[Brief explanation of the drawing]

FIGS. 1 to 4 are diagrams showing examples of cross-sectional shapes of hollow composite fibers of the present invention.

Claims (1)

[Claims] A hollow fiber in which a solid component A consisting of polybutylene terephthalate and a microporous component B consisting of a polyester having an intrinsic viscosity of 0.55 or less are composited side by side in a weight ratio of 30:70 to 70:30. , 2mg/
A polyester composite crimped yarn characterized by exhibiting a crimp rate (TC_2) of 7% or more when subjected to boiling water treatment under a load of de.