JPS6257920A - Polyester conjugated yarn - Google Patents

Abstract

PURPOSE:The titled yarn preventing see-through phenomena without lowering both deep color properties and clearness, wherein a porous polyester which contains no matting agent and has fine pores on the yarn surface and in its vicinity as a sheath part is positioned around a matting agent-containing polyes ter as a core part. CONSTITUTION:The polyester A containing >=1 wt.% matting agent (e.g., tita nium oxide, etc.,) is positioned as a core part and the porous polyester B which has no matting agent and the formed fine pores V arranged in the fiber axis direction on the yarn surface and in its vicinity is used as a sheath part, to give the aimed yarn. To be concrete, for example, the polyester A as the core component and a polymer containing both a metal-containing phosphorus com pound and an alkaline earth metallic compound for the porous polyester B as the sheath component are subjected to melt spinning by a sheath-core type spinning device, the prepared conjugated yarn is treated with an aqueous solu tion of an alkali compound, an additive in the polymer is eluted and a great number of fine pores are formed on the yarn surface and in its vicinity.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to polyester composite fibers.

More specifically, the present invention relates to a core-sheath type polyester conjugate fiber which has excellent deep color properties and sharpness, and which does not cause a sagging phenomenon when knitted.

(Prior Art) Conventionally, it has been reported in Japanese Patent Laid-Open No. 58-1983 that polyester fibers having a large number of micropores arranged in the fiber axis direction on the fiber surface and in its vicinity have excellent deep color properties and sharpness. 3628
It is well known from publications such as Japanese Patent Application Laid-Open No. 58-104215.

(Problems to be Solved by the Invention) When a matting agent is added to polyester fibers that have improved bathochromic properties and sharpness, the color becomes muddy or pastel-like, and the bathochromic properties , the addition of matting agents is usually not done because it reduces sharpness. Therefore, when it is made into a woven or knitted fabric, it becomes transparent and causes a so-called sagging phenomenon, making it unsuitable for ordinary clothing applications.

The present invention solves the problems of the prior art and improves bathochromic and
The aim is to prevent the shading phenomenon without reducing the sharpness.

(Means for Solving the Problems) The present invention has a polyester A containing at least 1.0% by weight of a matting agent as a core, and a fine polyester containing substantially no matting agent and arranged in the fiber axis direction. This is a polyester composite fiber characterized in that a porous polyester B having a large number of holes formed on the surface of the fiber and in the vicinity thereof is disposed in the sheath portion.

The polyester in the present invention is a polyester having terephthalic acid as the main acid component and at least one type of glycol, preferably at least one alkylene glycol selected from ethylene glycol, trimethylene glycol, and tetramethylene glycol as the main glycol component. The main target is

It may also be a polyester in which part of the terephthalic acid component is replaced with another difunctional carboxylic acid component, and/
Alternatively, it may be a polyester in which a part of the glycol component is replaced with the above-mentioned glycol other than the main component or another diol component.

Examples of difunctional carboxylic acids other than terephthalic acid used here include isophthalic acid, naphthalene dicarboxylic acid, diphenylcarboxylic acid, diphenoxyethane dicarboxylic acid, β-hydroxyethoxybenzoic acid, P-oxybenzoic acid, 5- Examples include aromatic, aliphatic, and alicyclic difunctional carboxylic acids such as sodium sulfoisophthalic acid, adipic acid, sebacic acid, and 1,4-cyclohexanedicarboxylic acid. In addition, examples of diol compounds other than the above-mentioned glycols include cyclohexane-1,
Examples include aliphatic, alicyclic, and aromatic diol compounds such as 4-dimetatool, neopentyl glycol, bisphenol A1, bisphenol S, and polyoxyalkylene glycol. Such polyesters may be synthesized by any method. For example, in the case of polyethylene terephthalate, usually terephthalic acid and ethylene glycol are directly esterified, a lower alkyl ester of terephthalic acid such as dimethyl terephthalate is transesterified with ethylene glycol, or terephthalic acid and ethylene oxide are transesterified. The first stage reaction is to react with the terephthalic acid glycol ester and/or its low polymer, and the first stage reaction product is heated under reduced pressure to polymerize until the desired degree of polymerization is reached. It is produced by a second stage of condensation reaction.

Polyester A according to the invention contains at least 1.0% by weight of a matting agent. If the content of the matting agent is less than 1.0% by weight, a sufficient anti-staining effect cannot be obtained. As the matting agent, conventionally known matting agents such as titanium oxide are used.

On the other hand, porous polyester B does not substantially contain a matting agent and has a large number of micropores (2) arranged in the fiber axis direction on the fiber surface and in its vicinity. Here, "substantially free of matting agent" means that it does not contain a matting agent to the extent that it adversely affects deep color and vividness, and usually contains no more than 0.2% by weight of matting agent. It is permissible to include agents. The micropores (3) have a maximum frequency in the frequency distribution of 0.000 mm in width in the cross-sectional direction perpendicular to the fiber axis.
The micropores (2) must not reach the core polyester A, and the length in the fiber axis direction must be within the range of 0.1-5 μm. is preferable for improving clarity.

As shown in FIGS. 1 to 4, the polyester composite fiber of the present invention consists of a polyester A containing 0.1% by weight or more of a matting agent as a core, and a porous polyester B having micropores.
Place it in the sheath. The composite cross-sectional area ratio of polyester A and porous polyester B is preferably 30:0 to 70:30 in order to achieve both bathochromic properties, sharpness, and prevention of scratches.

In particular, the cross-sectional shape of the polyester composite fiber of the present invention is
It is preferable to use a modified shape having three or more lobes as shown in FIGS. 2 to 4, since this improves sharpness and provides fibers with bulk and crispness. Note that FIG. 5 is a perspective view of the polyester composite fiber shown in FIG. 2.

The method for producing the polyester composite fiber of the present invention includes polyester A containing 1.0% by weight or more of a matting agent, a porous polyester B polymer containing a metal-containing phosphorus compound, and an alkaline earth metal compound. is melt-spun using a core-sheath type composite spinning device so that the former is located in the core and the latter is located in the sheath, and then the additives in the porous polyester everyday polymer are removed using an aqueous solution of an alkaline compound.
A method may be mentioned in which a large number of micropores are formed on the fiber surface and its vicinity by eluting more than % by weight.

The polymer for porous polyester B can be prepared at any stage until the synthesis of the polyester is completed by using the following general formula % formula % (0.5 to 3 mol% based on the acid component constituting the al polyester). and R2 are hydrogen atoms or -valent organic groups, R1 and R2 may be the same or different, M is an alkali metal or alkaline earth metal, m is 1 when M is an alkali metal, M 1 if is an alkaline earth metal
/2. ) and (bl
It is obtained by adding 0.5 to 1.2 times the mole of the alkaline earth metal compound to the metal-containing phosphorus compound without reacting (al and (bl) in advance, and then completing the synthesis of polyester. be able to.

In addition, the treatment with an aqueous alkali compound solution to form a large number of micropores in polyester B can be performed at any stage after melt composite spinning, and after processing such as heating, it can be further processed into a fabric. You can go later.

Examples of the alkali compound used here include sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, sodium carbonate, potassium carbonate, and the like. Among these, sodium hydroxide and potassium hydroxide are particularly preferred.

The concentration of such an aqueous solution of an alkali compound varies depending on the type of alkali compound, processing conditions, etc., but is usually 0.01.
The range of 40% to 40% by weight is preferred, and the range of 0.1 to 30% by weight is particularly preferred. The treatment temperature is preferably in the range of room temperature to 100 degrees Celsius, and the treatment time is usually in the range of 1 minute to 4 hours. Further, the amount of the alkaline compound eluted and removed by treatment with the aqueous solution should be in the range of 2% by weight or more based on the weight of the fiber.

After dyeing, this polyester composite yarn can be coated with a polymer having a lower refractive index than porous polyester fiber B, such as dimethylpolysiloxane or tetrafluoroethylene-propylene copolymer, to further improve its bathochromic properties. , clarity can be improved.

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

Parts and % in Examples indicate parts by weight and % by weight, and the depth of color when dyeing the obtained polyester fibers, the opacity of the fabric, and the size of micropores were measured by the following methods.

As a measure of the depth of the color, bathochromicity (K/S) was used. This value is the spectral reflectance R of the sample cloth for Shimadzu RC-3.
It was measured using a 30-type self-recording spectrophotometer and was obtained from the Kubelka-Munk 2 shown below.

The larger this value is, the greater the deep color effect is.

K/S=(1-R) 2/2R Note that K represents an absorption coefficient and S represents a scattering coefficient.

ii) Opacity Opacity - (Reflectance on the standard black backing plate (reflectance 6%)) ÷ (Reflectance on the mark white backing plate (reflectance 91%)) X100 (%) Regarding the transparency value, if the reflectance is equal when backed with a black backing plate and a white backing plate, it means that it is a completely opaque material with 100% opacity.On the other hand, when backed with a black backing plate When the reflectance is 0%, the opacity is 0%, indicating that the material is completely transparent.

iii) Size of micropores The surface of porous polyester fiber B was photographed with an electron microscope at a magnification of 3,000 times and measured.

Example 1 In the polymerization reaction step of polyethylene terephthalate, 0.7 mol% of calcium phosphoric acid diester calcium salt was added to dimethyl terephthalate and 0.9 times the mol of calcium acetate to the phosphoric acid diester calcium salt, Intrinsic viscosity 0.642. A polymer for porous polyester B having a softening point of 259°C was obtained.

On the other hand, polyethylene terephthalate containing 1.2% by weight of titanium oxide, having an intrinsic viscosity of 0.64 and a softening point of 260°C was used as polyester A, and was spun at 290°C from a core-sheath composite spinning device together with the porous polyester B polymer.
Melt-spun it at a speed of 1.300 m7 minutes,
A modified cross-section conjugate fiber having a core made of polyester A and a sheath made of porous polyester B polymer and having three earlobes was obtained. This composite fiber was stretched 3.037 times between a supply roller heated to 85°C and a stretching roller, and further 185°
Heat treatment was performed in a slit heater of C to obtain a polyester core/sheath composite fiber of 50 denier/36 filaments.

A plain woven fabric was prepared using the obtained composite fibers for the warp and weft. Next, it was subjected to a relaxing treatment using a rotary washer at boiling temperature for 20 minutes, and then treated with a 3.5% aqueous sodium hydroxide solution at boiling temperature to obtain a fabric with a weight loss rate of 20%.

The fabric after this alkali treatment is Dianix Black.
, HG-FS (Mitsubishi Chemical Industries ■ product) 15% owf
After staining at 13°C for 60 minutes, sodium hydroxide Ig/I
! and 'Hydrosulfide Ig/j! A black-dyed cloth was obtained by reduction washing with an aqueous solution containing the following at 70° C. for 20 minutes. The color depth (K/S) of this black dyed cloth was 26.2, the opacity was 88.2%, and it had excellent bathochromic properties and sharpness, and was free from shading. In addition, the bulkiness was good, and the texture was excellent with a crisp feel. As shown in FIGS. 3 and 5, the polyester composite fibers constituting the fabric are irregular cross-section fibers having three earlobes, with polyester A containing a matting agent located in the core and a sheath. It was a composite fiber with a core-sheath structure in which porous polyester B, which does not contain a matting agent, was located in a portion thereof (composite area ratio, polyester A: polyester B = 45: 55). In addition, the micropores of porous polyester B are distributed on the fiber surface and its vicinity, and do not reach the core polyester A, and the value with the maximum frequency in the frequency distribution is perpendicular to the fiber axis. Width in cross-sectional direction is 0.4 μm, length in fiber direction is 0.8
It was μm.

Examples 2 to 6 In Example 1, the composite area ratio of polyester A in the core and polyester B in the sheath was variously changed as shown in the table below, and other conditions were the same as in Example 1, and black dyed fabric was prepared. Obtained. The results are shown in the table below. In particular, the composite area ratio of polyester A in the core and polyester B in the sheath was 30.
:70 to 70:30 is preferable since both the deep color property, sharpness and anti-staining effect are good.

Examples 7 to 9 In Example 1, only the cross-sectional shape of the composite fiber is shown in FIG.
The shape was changed to that shown in FIGS. 3 and 4, and other conditions were the same as in Example 1 to obtain a black dyed cloth. The results are shown in the table below, and all were excellent in deep color and clarity, and had good anti-stain effect. In particular, those with irregular cross-sectional shapes having three or more earlobes as shown in Figures 3 and 4 are bulky,
The texture (sharpness) was extremely excellent.

(This page, blank space below) Comparative Example l In Example 1, fibers made only of porous polyester B were used instead of composite fibers, and the other conditions were as in Example 1.
Do the same and get black dyed cloth.

The color depth (K/S) of this black cloth was as high as 28.9, and the deep color property and sharpness were good, but the opacity was 33.2, and the shading phenomenon was observed, making it unsuitable.

Comparative Example 2 In Comparative Example 1, when 1.2% by weight of titanium oxide was added to porous polyester B, the opacity was 98.5, 1, and the sagging phenomenon disappeared, but the depth of the black color (K
/S) decreased to 16.3, resulting in poor deep color and sharpness.

Comparative Example 3 In Example 1, the titanium oxide content of polyester A was limited to 0.8% by weight, and the other conditions were the same as in Example 1 to obtain a black cloth. The color depth (K/S) of this black cloth was 26.7, and it was excellent in deep color property and sharpness, but the opacity was 68.0, and a shading phenomenon occurred, making it unsuitable.

(Effects of the Invention) According to the present invention, the core is made of polyester containing a matting agent of 1.0% or more, and the sheath is made of porous polyester with excellent deep color and clarity. It is possible to improve opacity and prevent blurring without deteriorating bathochromic properties or sharpness. Furthermore, by making the cross-sectional shape an irregular shape with three or more earlobes, the bulkiness is improved and a good crisp texture can be obtained.

[Brief explanation of drawings]

1 to 4 are cross-sectional views showing examples of the polyester conjugate fiber of the present invention, and FIG. 5 is a perspective view of the polyester conjugate fiber shown in FIG. 2. A: Core polyester, B: Sheath polyester, ■: Micropores, L: Earlobe.

Claims (1)

[Scope of Claims] 1. Polyester A containing at least 1.0% by weight of a matting agent is used as a core, and micropores substantially free of matting agent and arranged in the fiber axis direction are formed on the fiber surface and its surface. A polyester composite fiber characterized in that a sheath portion is provided with a plurality of porous polyester B formed nearby. 2. The polyester composite fiber according to claim 1, wherein the composite area ratio of polyester A in the core and polyester B in the sheath is 30:70 to 70:30. 3. The polyester composite fiber according to claim 1 or 2, which has an irregular cross-sectional shape having three or more earlobes. 4. The micropores of porous polyester B have a maximum frequency in the frequency distribution, and the width in the cross-sectional direction perpendicular to the fiber axis is within the range of 0.1 to 0.7 μm, and
The micropores did not reach the core polyester A,
The polyester composite fiber according to claim 1, 2 or 3, wherein the length in the fiber axis direction is within the range of 0.1 to 5 μm.