JPH0340811A - Modified cross-section polyester fiber - Google Patents

Abstract

PURPOSE:To obtain the subject fiber, having many inverted wedge-shaped grooves parallel to the fiber axis direction and excellent in water absorption rate and amount thereof with soft hand by producing a fiber of a cross-sectional shape having a specified size of a matrix part, number of protruding parts, connecting length, average distance, etc. CONSTITUTION:The objective fiber, obtained by copolymerizing polyethylene terephthalate with polyethylene glycol with preferably 600-4000 molecular weight and having >=1d size of a matrix part 1, >=0.2mum connecting length of protruding parts 2, 5-30 number of the protruding parts 2, 3mum average shortest distance (Li) between the protruding parts 2, the average largest distance (La) of >=1.5 times based on the Li and <=0.8d average size of the protruding parts 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to polyester fibers, and more particularly to polyester fibers having excellent water absorption properties and having a large number of continuous strands in the length direction of the fibers.

[Prior Art] Various attempts have been made to impart water absorbency to polyester fibers. One way to do this is to improve water absorption through irregularly shaped cross sections.For example, JP-A-62
-28405, Japanese Unexamined Patent Publication No. 57-5912, etc.

The former aims to improve water absorption by making the cross section into a ■-shaped cross section, but although the water absorption is improved, it has the drawback of high bending rigidity and the product having a rough and hard texture. was.

Furthermore, although the latter was provided with continuous wedge-shaped slits in the axial direction of the fibers, the improvement in water absorption was insufficient.

Furthermore, techniques using a combination of the cross-sectional shape of fibers and other techniques are also known. For example, Japanese Patent Application Laid-Open No. 56-20612. This technology creates hollow fibers and gives the fiber surface micropores that partially penetrate into the hollow part, but although it has a water absorption effect, the color clarity is insufficient and the frosting is It has disadvantages that are easy to occur.

As mentioned above, various technologies have been disclosed for improving the water absorbency of polyester, but no technology has been disclosed that achieves good water absorption and maintains the excellent fiber physical properties originally possessed by polyester. The reality was that there was no such thing.

On the other hand, although it is not aimed at improving water absorption, there is a fiber similar to the cross-sectional shape of the present invention published in JP-A-52-1.
No. 14772 and No. 64-14321 have been proposed. However, the former shape is significantly different from the shape of the present invention because the protrusion is not connected to the base component.
The effect of improving water absorption, which is the objective of the present invention, is hardly observed. In addition, in the latter case, the protrusions are not actively connected to the parent body, and for this reason, after the sea components have been eluted, most of the protrusions have peeled off, resulting in little improvement in water absorption and the product has not been commercialized. It has the disadvantage that the frosting phenomenon and poor anti-pilling properties become apparent even after drying.

Furthermore, the water absorbency, which is the main objective of the present invention, was also unsatisfactory.

[Problems to be Solved by the Invention] An object of the present invention is to provide a fiber that has the characteristics inherent to polyester fiber and has significantly improved water absorption.

[Means for Solving the Problems] An object of the present invention is to provide a polyester fiber consisting of a matrix part and a protrusion protruding from the matrix part, in which the fineness of the matrix part is 1 d or more, and the fineness of the matrix part and the protrusion part is The connection length is 0.2
Connected over a length of μm or more, the number of protrusions is 5
30 or more, and the average shortest path 1 (Li) between the protrusions is 3 μm or less, and the position of the average shortest distance is 0.5 μm or more outside the base surface, and the average shortest path is 3 μm or less. The average longest distance (La) between the protrusions inside the position of is the average shortest pressure between the protrusions 1ff (Li
), and the average fineness of one protrusion is 0.
．． This can be achieved by using irregular cross-section polyester fibers that are characterized by having good water absorption properties of 8d or less.

The cross-sectional shape of the polyester fiber of the present invention will be explained with reference to FIG.

The base portion and the protrusion portion of the present invention are respectively referred to as l in FIG.
, and 2, the parent part and the protrusion can be distinguished from the cross-sectional shape after dyeing if the dyeability of each polymer is different, or from the shape if the amount of 1102 added is different. When the protrusion and the base part are made of the same polymer, the base part,
and segment the protrusions.

(Fineness of the matrix part) The matrix part forms the skeleton of the fiber of the present invention, and has a great influence on the physical properties of the fiber, the texture of the fabric made of this fiber, and the processability including spinning. In this sense, the fineness of the matrix portion must be 1d or more. On the other hand, the fineness of the base portion is preferably 5 d or less, more preferably 3 d or less, in view of the texture represented by the tension and waist of the fabric.

(Connection of Protrusions) The protrusions 2 are substantially connected to the base body part 1. That is, "substantially connected" refers to a state in which when arbitrary ten filaments are photographed and observed, the protrusions are connected with a connection length of 0.2 μm or more. Connection length is 0.
If the thickness is less than 2 μm, the protrusions are likely to peel off from the base portion during various subsequent treatments or when worn as clothing, making it impossible to achieve the object of the present invention.

(Number of protrusions) The number of protrusions per fiber is required to be 5 or more in order to exhibit the water-absorbing effect, preferably 7 or more, more preferably 9 or more. 5 or more If the number of protrusions is small, the effect of improving water absorption is small.If the number of protrusions is large, the effect of improving water absorption is recognized, but if the number exceeds 30, the effect reaches saturation and is meaningless.Preferably 20. The number is preferably 15 or less.

(Positional relationship between the protrusions) Regarding the positional relationship between the protrusions and the protrusion and the positional relationship between the protrusion and the base body, the basic shape is that the protrusion is connected to the base body on the surface of the base body. In the present invention, the distance between the protrusions on the outside (Li in Fig. 1) is smaller than the distance between the protrusions on the outside (La in Fig. 1) where the protrusions are not connected. This has a major feature, and this is fundamentally different from the conventional so-called model, in which the outer part of the fiber has wider spacing. It is thought that this difference in basic shape greatly contributes to the improvement in water absorption.

(Average shortest distance between protrusions) The average shortest distance between protrusions (Li) is an arbitrary 10
This value is the average value obtained by photographically observing a cross section of a filament larger than a book, measuring the shortest distance between each protrusion. It is necessary that the interval is 3 μm or less.

The thickness is preferably 2 μm or less, more preferably 1 μm or less. If the average shortest distance between the protrusions exceeds 3 μm, the water absorbency, which is the objective of the present invention, will decrease, making it impossible to achieve the objective. Note that if the average shortest distance between the protrusions is too low, the water absorbency will decrease, so it is preferably 0.1 μm or more. Here, if there is a portion where the protrusions are not evenly connected, the distance between that portion and the adjacent protrusion is not referred to as the average shortest distance in the present invention. The position of the average shortest distance between the protrusions must be 0.5 μm or more away from the surface of the base body. The reason for this is that if the average shortest distance between the protrusions is too small, the effect of improving water absorption, which is the effect of the present invention, will be reduced. Preferably 1
It is at least μm, more preferably at least 2 μm.

<Average longest distance between protrusions> On the other hand, the average longest distance between protrusions (La) is the distance between protrusions located inside the position of the average shortest distance between protrusions. This refers to the average longest distance, and is the average value obtained by photographically observing the cross section of 10 or more arbitrary filaments, measuring the average longest distance defined above between each protrusion and the protrusion. Note that adjacent portions where the protrusions are not evenly connected are not included in the calculation. The average longest distance between the protrusions must be at least 1.5 times the average shortest distance between the protrusions defined above.

In this way, when the ratio is 1.5 times or more, the water absorption performance increases. Preferably it is 2.0 times or more, more preferably 2.5 times or more. - On the other hand, the larger this ratio is, the more preferable it is, but considering constraints from the appropriate fineness of each of the core and protrusions, and constraints from texture, the preferable ratio is 10 times or less, more preferably 5 times or less, particularly preferably 4 times or less. It is.

(Cross-sectional shape) The cross-sectional shape of the base portion is not particularly limited, and may be substantially circular (FIG. 1), triangular (FIG. 3), or quadrangular (FIG. 4).

In particular, when imparting directional glitter, a substantially triangular cross-sectional shape or a substantially square cross-sectional shape is preferable because it exhibits this effect.

On the other hand, the protrusion is not particularly limited, and a substantially circular cross section (FIGS. 1 to 5), a substantially elliptical cross section, a substantially quadrangular cross section (FIG. 6), etc. are preferably applicable.

(Fineness of protrusions) Since protrusions form not only the surface of the fibers but also the surface of the fabric, the fineness of the protrusions should be 0°8d or less in order to achieve a soft texture. If you want to make the texture even softer, it is preferably 0.4d or less, and if you want to make it even softer, it is preferably 0.2d or less.

(Polymer) Polyethylene terephthalate is particularly preferred as the polymer constituting the matrix, but depending on its use, commonly known copolymerization components such as isophthalic acid, 5-sodium sulfoisophthalic acid, etc. Copolymerized polyesters such as dicarboxylic acids and diols typified by polyethylene glycol can be used.On the other hand, the polymer for the protrusions is not particularly limited, and can be determined depending on the use of the fiber.

To further improve water absorption, the molecular weight is 600 or more, 400
Polyethylene terephthalate copolymerized with 0 or less polyethylene glycol (PEG) can be preferably used.

The fiber of the present invention can be produced, for example, as follows.

That is, a composite yarn consisting of three components 1, 2.3 as shown in FIG. 2 is produced. At this time, polymers can be selected for the base portion 1 and the protrusion portion 2 according to the respective purposes described above. However, since the sea component 3 obtains the fiber of the present invention by eluting the sea component from the three-component fiber, it is preferable that the sea component has a different solubility from that of the matrix portion and the protrusion portion. In other words, it is preferable that the solubility of the sea component is clearly greater than the solubility in the matrix and protrusions. Particularly preferably, the solubility is 1
It is 0 times or more higher, more preferably 30 times or more. Further, as for the polymer species of the sea component, polyester may be used, but polymers having completely different solubility from polyester, such as polyolefin, can also be effectively used. The advantage of using polyolefin is that the matrix and protrusions are hardly affected by the solvent when eluting sea components.

The melt viscosity of the sea component for these protrusions is 0°2 or more,
1.2 or less is preferable. This is because the shape of the protrusion is greatly affected by the melt viscosity ratio of the sea component.
More preferably, it is 0°3 or more and 0.8 or less. Regarding the silk spinning method, first, a core 1 having a protrusion 2 is made to form a composite flow with the sea component as a sheath, but this core-sheath composite flow is not a concentric composite flow, but the position of the protrusion is adjusted to the final three-component composite flow. It is preferable that the core-sheath composite flow is eccentric toward the center when The eccentricity is preferably such that it is eccentric by 10% or more of the radius in the direction of the center of the three-component composite flow, when the state where the center of the protrusion in the sea component is located at the center of the sea component is 0%. It is preferably 30% or more.

The sea component for this and the position of the protrusion channel of the mouthpiece hole for forming the protrusion are 10% as in the eccentric state of the composite flow above.
It is preferably at least 30%, particularly preferably at least 30%. Forming six or more of these two-component composite flows for each filament,
These composite polymer streams are then distributed around the matrix 1 at equal intervals, discharged from one nozzle, and wound up as an undrawn yarn. Stretching is then carried out in a conventional manner.

Of course, regarding the spinning method, the direct spinning method (DS)
D>, a method of obtaining the raw yarn at once by POY drawing or ultra-high speed spinning can also be adopted.

The fibers and fabrics of the present invention can be obtained by making the obtained yarn into woven or knitted fabrics as appropriate, and then alkali treatment at 98°C with a 1% by weight or more NaOH aqueous solution to elute sea component 3. can.

[Example] The present invention will be explained in more detail by giving examples.

The measurement methods described in the Examples below are as follows.

(Water absorption by bi-leg method) A fabric consisting of horizontal and vertical threads was cut into strips of 15 cm in length, and the lower end was immersed in distilled water at 20 ± 2°C, and the water absorption height after 10 minutes was measured. was measured. The height of the water is (mm)
).

Example 1 The polymer of the base part and the protrusion part has an intrinsic viscosity of 0.63
of polyethylene terephthalate and 5-sodium sulfoisophthalic acid as a polymer for the sea component.
A copolymerized polyethylene terephthalate having an intrinsic viscosity of 0.55 and having a mol% copolymerization was prepared. These dry polymers are individually melted to once produce a three-component composite gold thread as shown in FIG. To do this, first, with the protrusion 2 as the core,
In order to create an eccentric core-sheath composite flow using sea component 3 as a sheath, an eccentric core-sheath composite polymer flow is formed from the eccentric mouth hole to each final discharge nozzle ↓ 10 units per hole, and then these composite polymer flows are They are arranged at equal intervals around part l and discharged from one final nozzle.

A 3-component composite undrawn yarn of 174 denier and 12 filaments consisting of a matrix portion, a protrusion portion, and a sea component was obtained by the method explained in the above manufacturing method.

At this time, the composite ratio is 1 for the base part, protrusion part, and sea component, respectively.
They were 1, 6 g/min, 5, and 8 g/min.

This undrawn yarn was heated to 269°C using a hot roller at 85°C.
60 denier by stretching at 600 m/min.
A raw yarn of 12 filaments was obtained.

A taffeta fabric is made with these drawn yarns arranged in the warp and weft, and then weight loss treatment is performed at 98°C with an alkaline solution containing 1% NaOH (by weight) to completely dissolve the sea component, resulting in a cross section as shown in Figure 1. A polyester yarn of the present invention having the following properties was obtained.

When this fabric was subjected to a water absorption test using the bileg method, the water absorption height was 29 mm.

Examples 2 to 6 Tests were conducted under the same conditions as in Example 1, except that the composite ratio of the protrusions was changed as shown in Table 1. The water absorption test results are shown in Table 1. The polymer used for the base portion and the protrusion portions in Example 6 was polyethylene terephthalate having an intrinsic viscosity of 0.63, which was copolymerized with 5% by weight of PEG having a molecular weight of 11,000. The water absorption results are as shown in Table 1, and all showed good water absorption.

Comparative Examples 1 to 5 In Comparative Example 1, the number of protrusions per textile water was 4, and in Comparative Example 2, the number of protrusions was 4, and the fineness of the protrusions was changed to 1 denier. In Comparative Example 3, the fineness of the protrusions was set to 0.6 denier, and the average longest distance between the protrusions was smaller than the shortest distance between the protrusions. Comparative Example 4 was the same as Example 1 except that concentric core-sheath composite spinning of the protrusion and the sea component was performed to create a cross-sectional shape of the fiber in which the matrix and the protrusion were not connected at all. Comparative Example 5 used ordinary circular cross-section polyester fibers. In Comparative Example 6, an octlobal cross-section fiber having a degree of deformation of 1.2 was prepared and evaluated from substantially non-copolymerized polyethylene terephthalate.

The water absorbency of this fiber is as shown in Table 1), and it is significantly inferior in water absorbency compared to the example of the present invention. It was obvious.

(Margins below) Table 2 [Effects of the invention] Since the polyester fiber obtained by the present invention has a large number of inverted wedge-shaped grooves parallel to the fiber axis, the water absorption rate,
Both the amount of water absorption is significantly improved compared to conventional polyester fibers.

Furthermore, since there are thin fibers on the surface of the fibers, not only the fibers themselves but also the fabric made of these fibers have a very soft texture. Furthermore, because the distance between the protrusions is small and there are many grooves, the effect of improving the color development of dyed products has been observed. The effect of improving color development is also evident, probably because the amount of light absorbed inside the fiber increases due to the copolymerization of isophthalic acid.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the fiber of the present invention, and FIG. 2 is a cross-sectional view of the fiber of the present invention before the sea component is removed. 1: Base body part 2: Projection part 3: Sea component La: Average longest distance Ll: Average shortest distance 3UA, FIG. 4, FIG. 5, and FIG. 6 are cross-sectional views of the σ fiber of the present invention, and FIG. is a filament other than the one of the present invention.

Claims (1)

[Claims] A polyester fiber whose cross-sectional shape consists of a matrix part and a protrusion protruding from the matrix part, the fineness of the matrix part is 1 d or more, and the connection length of the matrix part and the protrusion part is 0.2 μm
The number of protrusions is 5 or more and 30 or less, and the average shortest distance (Li) between the protrusions is 3 μm or less, and the position of the average shortest distance is The average longest distance between protrusions (
La) is 1 of the average shortest distance (Li) between the protrusions.
An irregular cross-section polyester fiber characterized by having good water absorbency of 5 times or more and an average fineness of one protrusion of 0.8 d or less.