JPH04245907A - Production of synthetic fiber having good coloring property - Google Patents

Abstract

PURPOSE:To dispose many grooves on the surface of a fiber to provide the fiber having a highly coloring property, each of the grooves having a specific shape in the longitudinal direction of the fiber. CONSTITUTION:When a fiber having grooves in its longitudinal direction is produced by subjecting a bicomponent conjugate fiber to a dissolution treatment to dissolve the component B, the conjugate fiber having a cross section in which the easily soluble component B is divided into four or more portions with the component A, a relation among the ratio of the dissolution rate of the component B, the shape of the component B and the shape of each groove of the fiber after the dissolution of the component B is specified, and the ratio of the width of each groove to the whole circumferential length of the cross section of the fiber is also specified. The grooves having shapes required for the improvement in the color generation are thereby readily produced, and the improvement in the color generation of the fiber is secured.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing synthetic fibers with good color development, and more particularly to a method for producing synthetic fibers with a unique irregular cross section and good color development.

0002

BACKGROUND OF THE INVENTION Thermoplastic synthetic fibers, particularly polyester fibers, have poor color development properties, and various studies have been made heretofore. For example, the invention described in JP-A-52-99400 increases light absorption and improves color development by imparting fine irregularities to the surface of fibers, but this method does not improve black color development. Although an effect was observed, the effect was insufficient, and almost no improvement in chromatic color development was observed.

On the other hand, many proposals have been made regarding composite fibers forming slit-like grooves. For example, JP-A-56-16
Since the invention described in Japanese Patent No. 5015 is not intended to improve color development, the groove shape is not sufficient to increase light absorption, so the effect of improving color development cannot be obtained. Although the invention described in JP-A No. 57-5912 stipulates the ratio of the groove depth and groove width, the absolute value of the groove width and depth is not specified, so the coloring property is not sufficiently improved. You can't get any effect.

[0004] Furthermore, Japanese Patent Application Laid-Open No. 61-282449,
JP-A-1-162813, JP-A-2-26912
The inventions described in JP-A-62-223321 and JP-A-62-223321 are both composite fibers for obtaining ultrafine fibers, in which easily eluting components are arranged so as to surround island components, and the amount of dissolved easily eluting components is reduced. If there is too much, the fibers will split and the color development will be significantly reduced. Furthermore, JP-A-63-105114
The invention described in the publication proposes the provision of a large number of grooves for the purpose of improving dyeability and the color development of fibers having specified particles. In order to achieve this, it is most important to specify the shape of the groove that substantially absorbs light on the fiber surface and the width of the groove in the cross section. Furthermore, sufficient color development cannot be obtained because the cross-sectional shape before elution to create the grooves and the properties of the eluted components have not been specified. As mentioned above, various composite fibers have been proposed, but none of them have been able to sufficiently improve color development.

[0005]

[Problems to be Solved by the Invention] The object of the present invention is to provide a method for producing fibers that have good not only black coloring properties but also chromatic coloring properties by forming highly precise groove shapes along the fiber axis. It is about providing.

[0006]

[Means for Solving the Problems] The present invention solves the problem by dissolving a two-component composite yarn in which the A component divides the B component into four or more parts, thereby mainly dissolving the B component and dissolving the B component into four or more parts. In the method of providing continuous grooves of 1 or more, the relationship between the width c of the B component at the composite yarn stage, the dissolution rate ratio S of the B component to the A component, and the width w of the groove after dissolution satisfies the following formula, A method for producing synthetic fibers with good color development, characterized by providing grooves in which the total width w of the grooves is controlled to be 0.1 or more of the total circumferential length of the fiber.

c+(5/S)-0.5≦w≦c+(15
/S)+1.0 where the units of c and w are μm.

Before describing the present invention in detail, the circumstances by which the present inventors arrived at the present invention will be explained in relation to how important the shape of the grooves is when obtaining fibers with high color development by providing grooves. 3 to 5 are graphs showing the relationship between groove morphology and color development in polyester fibers. FIG. 3 is a graph showing the brightness (hereinafter referred to as L value) when dyed black with respect to the width of grooves that are substantially parallel to the fiber axis. Further, FIG. 4 is a graph similarly showing the relationship between the L value and the depth of the groove. Further, FIG. 5 is a graph showing the relationship between the ratio of the total width of the grooves to the total circumferential length of the fiber and the L value. Figure 3~
As is clear from No. 5, when improving color development by providing grooves in fibers, it is not expected to improve color development simply by providing grooves. In other words, it is understood that it is important to quantitatively specify the width of the groove, the depth of the groove, or the total width of the groove relative to the circumferential length of the fiber. FIG. 1 is a cross-sectional view showing an example of a fiber obtained by the present invention.
has ten protrusions 2, and the same number of approximately triangular grooves 3 as the number of protrusions are present between the protrusions.

FIG. 2 is a cross-sectional view showing an example of the two-component composite yarn of the present invention before dissolution treatment. In FIG. 2, the polymer consists of two components: an easily soluble component B (hereinafter referred to as component B) and a poorly soluble component A (hereinafter referred to as component A) each having 10 wedge shapes. By dissolving the two-component composite yarn shown in FIG. 2 with a solvent, component B is eluted and the fiber shown in FIG. 1 is obtained.

[0010] Polymers applicable to the method of the present invention include polyester, polyamide, and polyacrylic, with polyester being particularly preferred. As the polyester, not only homopolyesters but also commonly used copolyesters can be preferably used, and commonly used additives may also be added. Since the fibers obtained by the present invention have improved color development, in order to apply the present invention more effectively,
As component A, it is preferable to use a polymer that causes as little reflection inside the fiber as possible. For this purpose, the amount of particles contained inside the fiber is preferably 0.1% by weight or less, and 0.0% by weight or less.
It is particularly preferred to use a polymer with excellent transparency that is 3% by weight or less.

[0011] In the two-component composite yarn, it is preferable that the dissolution rate of component B, which is eluted by the solvent, is at least twice as high as that of component A, which is relatively difficult to be eluted by the solvent. If the dissolution rate of component B is less than twice that of component A, a large amount of component A will also be dissolved, making it impossible to obtain the fiber cross-sectional shape necessary for improving color development. Therefore, the dissolution rate should be at least twice that of component A. Preferably it is 5 times or more, particularly preferably 20 times or more. However, on the other hand, if the dissolution rate of component B is too high, the disadvantage of increasing instability with respect to various solvents will increase, so the ratio of the dissolution rate of component B to component A is preferably 100 times or less.

As the solvent for component B, an alkaline aqueous solution such as sodium hydroxide is most preferably used. As a means to increase the alkali dissolution rate of component B, in the case of polyester, it is preferable to copolymerize 1 mol% or more of a sulfonic acid metal salt, which can efficiently increase the dissolution rate at the same copolymerization rate. If the copolymerization rate of the sulfonic acid metal salt is less than 1 mol %, the dissolution rate will not increase. It is particularly preferable to copolymerize the sulfonic acid metal salt in an amount of 2.5 mol% or more, more preferably 4 mol% or more. However, copolymerization of 6 mol % or more is not preferable because excessively high copolymerization causes disadvantages such as a significant increase in melt viscosity. A preferred sulfonic acid metal salt as a copolymerization component is 5-sodium sulfoisophthalic acid. In principle, component B is eluted by dissolution treatment, but the surface of component A after component B is eluted is affected by the amount and diameter of fine particles contained in component B. In other words, A
The surface of the component preferably has fine irregularities in view of the effect of improving color development. In order to develop a replica effect, component B preferably contains particles such as titanium dioxide in an amount of 0.1% by weight or more, more preferably 0.4% by weight or more.

[0013] In order to take in sufficient light, the number of grooves after dissolution treatment must be 4 or more, and for this purpose it is necessary to radially divide the B component into 4 or more grooves with the A component. . If there are less than four, the amount of light taken in will be insufficient. The number of divisions is preferably 6 or more, particularly preferably 10 or more, but the division is preferably 15 or less because the effect of improving color development becomes saturated and the thickness of the protrusions becomes thinner, resulting in poor color development. .

In order to fully exhibit the color development which is the object of the present invention, it is important to form the grooves in the direction of the fiber axis as described above. The shape of component B and the dissolution rate ratio of component B to component A at the composite thread stage before elution are very important. In other words, the factors that influence the groove shape after elution are the shape of component B before elution and the dissolution rate ratio of component B to component A.
There is no meaning in determining these two factors independently, and a preferable groove shape that satisfies the coloring properties can only be formed when these two factors are within specified ranges.

That is, the width c of the B component before elution, which will be described later.
It is necessary that the dissolution rate ratio S of the B component to the A component and the width w of the groove after the B component is eluted satisfy the following formula. c+(5/S)-0.5≦w≦c+(15
/S)+1.0 where the units of c and w are μm. If the above relationship is not satisfied, the width of the grooves 3 in the cross section of the fiber will be too narrow, or the width of the protrusions 2 will be too thin, making it difficult for the fiber to exhibit the desired color development. Preferably c+(5/S)≦w≦c+(15/S)+0.
5.

[0016] What has a great influence on the fiber cross section in order to sufficiently exhibit the effect of improving color development is the dissolution rate ratio of the B component and the shape of the A component and B component at the composite yarn stage. The widths a and b of the A component are preferably 5 μm or more, particularly preferably 7 μm or more. The widths a and b of the A component are 5
If it is less than μm, the width of the protrusions of the resulting fibers will be narrow, the amount of transmitted light will increase, and the color development will be insufficient. A depending on fineness
Since the width of the component and the width of the B component are determined, if the A component is too large, the width of the B component will become small.
is preferably 20 μm or less. Note that the widths of the A component and B component are determined by the method described later.

[0017] The shape of the B component is such that the width c of the B component is 1.0 μm.
The thickness is preferably 2.0 μm or more, particularly preferably 2.0 μm or more. The width d of the B component is preferably 0.7 μm or more, particularly preferably 1.0 μm or more. B component width c
If it is less than 1.0 μm, the amount of light taken into the fiber will be insufficient, resulting in insufficient color development improvement effect.

[0018] In order to increase the effect of improving color development, it is necessary to allow more light to enter, and for this purpose, it is effective to increase the proportion of grooves on the outer periphery of the fibers as much as possible. Therefore, it is necessary that the sum of the widths of the grooves relative to the entire circumferential length of the fiber cross section after melting treatment is 0.1 or more, preferably 0.3 or more. For this purpose, it is preferable that the ratio of the width of the A component to the total circumferential length of the fiber cross section before melting treatment is 0.90 or less. Particularly preferably, it is 0.8 or less.

Increasing the length of component B increases the depth of the groove after melting and loss, which is preferable, but on the other hand, it has the disadvantage that the fibers tend to break. Therefore, the length of the B component is preferably 0.40 times or less of the fiber thickness in the center direction of the B component. The length of the B component is 0.4 of the fiber thickness in the center direction of the B component.
If it exceeds 0 times, it is not preferable because the resulting fibers are easily broken and the color development becomes insufficient, probably because the amount of transmitted light incident on the fibers increases. Preferably it is 0.25 times or less.

Further, in order to prevent fiber cracking, it is preferable that all the A components are continuous in the cross section of the fiber, and it is not preferable that the A component is discontinuous due to the B component.

The two-component composite yarn thus obtained is
By dissolving in a hot solvent such as a hot alkaline aqueous solution, component B is mainly eluted. Ratio is 0.8 or more, protrusion thickness is 1μ
If the number of grooves is 4 or more, fibers with 4 or more grooves can be obtained. In this case, the dissolution treatment may be carried out at any stage, but it is preferably carried out after the fabric is made, since handling is easy.

[0022] In order to make the fibers obtained by the present invention more highly colored, it is important to absorb more light, and the groove width is preferably 1.5 μm or more, particularly preferably 2.5 μm or more. be. In order to absorb more incident light inside the fiber, it is advantageous for the groove to be deep, and the depth of the groove is preferably 2.0 μm or more, particularly preferably 3.0 μm.
m or more. In addition, in order to absorb more light inside the fiber, it is advantageous to have a larger ratio of the groove depth to the groove width, and the ratio of the groove depth to the groove width is preferably 1.2 or more. 5 or more is particularly preferred.

The fibers obtained by the present invention do not significantly reduce the effect of improving color development depending on the polymer type, so they can be made with polymers having a wide range of melt viscosities, various copolymerized polymers depending on the purpose, and various additives. It can be applied to an extremely wide range of polymers, such as polymers that have The method for producing fibers of the present invention can be widely used. The spinning speed can be applied to any spinning speed range of 800 m/min to 2000 m/min to obtain undrawn yarn, 2000 m/min to 4000 m/min to obtain POY, and even 4000 m/min or more. Of course, direct spinning and drawing can also be effectively used.

[0024] The cross-sectional shape of the fibers can be any of the commonly used cross-sections such as circular, three-lobed, five-lobed, and flat. Among these, a flat cross-sectional shape can be preferably used because it has a substantially long circumference.

The fibers obtained in the present invention may be used as raw silk, but they can also be effectively used in various processed yarns such as strongly twisted yarns and false twisted yarns without impairing the improvement in color development. It is preferable to apply post-processing for the purpose of high color development to the fibers obtained in the present invention because the color development is further improved.

[0026] The particle amount, L value, and fiber cross-sectional shape in the present invention were measured by the following method. A. Particle amount: 100g of polyester was dissolved in 900cc of orthochlorophenol, and the solution was heated at a speed of 14,000 min.
After centrifuging for 60 minutes, separate the supernatant, add orthochlorophenol, repeat the centrifugation to remove the polyester component, and then divide the resulting weight by the weight of the polyester used for dissolution. It is expressed as a value.

B. L value: A cylindrical knitted fabric was created by aligning two strands using a 24-gauge tube knitting machine and refined. Continue to 180℃
After the dry heat treatment, dissolution treatment is performed with an aqueous sodium hydroxide solution, and then the dye Dianix Black B
G-FS200 7% OWF. At this time, Sunsolt 1200 0.5g/liter and Fixer PH5000 0.5g/liter were used as auxiliaries. Dyeing is carried out at a bath ratio of 1:100 at a dyeing temperature of 130° C. for 60 minutes. Next, reduction cleaning was performed at 80° C. for 20 minutes using hydrosulfite 2 g/liter, sanded 0.5 g/liter, and caustic soda 0.5 g/liter. After drying the obtained dyed tubular knitted fabric, the lightness (L) value was measured using an SM color computer SM-3 manufactured by Suga Test Instruments Co., Ltd.

C. The width of the A component and the B component was determined by dyeing the two-component composite yarn before elution to give a dyeing difference between the A component and the B component, and plotting the width as shown in FIG. 6. (a) Width a of A component: In Fig. 6, line segment DC connecting boundary points D and C' between A component and B component on the surface of the composite yarn
' is the length. (b) Width b of component A: line segment EF connecting the midpoint E of line segment CD in Figure 6 and the boundary point F between component A and component B in the internal direction of the composite yarn
The line segment EF passes through a 10% point from the point F of the line segment EF at
When boundary points G, H and G', H' are perpendicular to If it is longer than 0.40 times the thickness of the composite yarn, it is the width of the A component at a point 0.40 times the thickness of the composite yarn from the surface of the composite yarn of the B component. (c) Width c of component B: line segment CD in FIG. (d) Width d of component B: If the length of line segment GH in FIG. This is the width of component B at a point 0.40 times the thickness of the composite yarn from the surface of the composite yarn of component B.

D. The shape of the grooves and protrusions The cross-sectional shape of the fiber after elution was determined by making a section with a thickness of about 5 μm and observing it with a scanning electron microscope. The cross-sectional shape is schematically shown in FIG. (a) Groove width w: Draw a common tangent that touches the protrusions on both sides of the relevant groove, let the contact points be K and L, and line segment KL
Let M be the midpoint of Further, the deepest point of the groove is defined as point R, the line segment connecting point M to point R is defined as line segment MR, and its length is defined as e. On line segment MR, from point M to a point 5% of line segment MR as point N
Let the length of the line segment MN be f. Line segment MR passing through point N
Draw a line perpendicular to , and the intersections with the protrusions on both sides are P, respectively.
When Q, the length of the line segment PQ is the width w of the groove. (b) Groove depth: ef in FIG. (c) Thickness of protrusion: Draw the adjacent groove in the same way according to the method in (a), and draw each point corresponding to points K, L, M, N, P, Q, R as K', L', M', N', P', Q',
When R' is assumed, the length of the line segment QP' is the thickness of the protrusion. (d) Ratio of the total width w of the grooves to the total circumferential length: When the total circumferential length is the sum of the total thickness of the protrusions over the entire fiber cross section and the total width of the grooves, the width of the grooves to the total circumferential length Expressed as a ratio of the sum of w.

[0030]

EXAMPLES The features of the present invention will be further explained in detail in the following examples.

Example 1 Polyethylene terephthalate containing 0.02% by weight of particles and having an intrinsic viscosity of 0.67 as component A and 2.5 mol% of 5-sodium sulfoisophthalate as component B were copolymerized. , polyethylene terephthalate containing 0.3% by weight of titanium dioxide and having an intrinsic viscosity of 0.56 was used. The dissolution rate of component B in these polyesters was 8.5 times that of component A. Component A divides component B into 10, and the weight ratio of component A/component B is 8.
Melt spinning was performed at a composite ratio of 0/20, followed by stretching. The obtained polyester fiber had a single yarn denier of 7.1 denier. As a result of dyeing this fiber with a basic dye and observing the cross section of the fiber, the width c of the B component was 1.
1 μm, the width d of the B component is 0.9 μm, the width a of the A component is 7
．． The width b of the A component was 7.8 μm, and the length of the B component was 2.8 μm. The obtained drawn yarn was used to make a 24-gauge jersey knitted fabric, and this knitted fabric was then refined and treated with 32% by weight of sodium hydroxide in a hot aqueous solution of 98°C.
Dissolved. After dissolution treatment, this knitted fabric is disassembled and
When the disassembled fibers were observed using a scanning electron microscope, the groove width w was 2.5 μm, the groove depth was 3.3 μm,
The width of the protrusion was 3.0 μm. On the other hand, as a result of measuring the L value after dyeing the knitted fabric black, the L value was 11.4.
It showed very good color development. In addition, this knitted fabric had a smooth texture and good water absorption.

Example 2 The same procedure as in Example 1 was carried out except that the number of B components was reduced to six. As a result of the decrease in the number of grooves after elution, the effect of improving color development was inferior to that in Example 1, but a sufficient effect of improving color development was observed. The results are listed in Table 1.

Example 3 A test was carried out in the same manner as in Example 1 except that the composite ratio of component A/component B was changed to 90/10. As a result, the drawn yarn,
The cross-sectional shape after the dissolution treatment was as shown in Table 1. Further, the L value was 12.4, indicating good color development.

Example 4 The dissolution rate ratio of component B to component A was set to 30,
The same procedure as in Example 1 was carried out except that the composite ratio of component A/component B was 70/30.

Example 5 The same procedure as in Example 1 was carried out except that the dissolution rate ratio of component B to component A was set to 30 as in example 4. The results are shown in Table 1, and as a result of the narrower groove width, it was slightly inferior to Example 1, but showed good color development.

Comparative Example 1 A 24-gauge jersey knitted fabric was made using fibers consisting of only the polyester used as component A in Example 1, with a single yarn fineness of 7 d and a circular cross-sectional shape. Other than that,
The test was conducted in the same manner as in Example 1. The results are shown in Table 1, and the L value was 13.7, which was insufficient.

Comparative Example 2 Same as Example 1 except that the polyester used in Example 5 was used as the B component, the composite ratio of the B component to the whole was 8% by weight, and the dissolution loss rate was 15% by weight. The same procedure was carried out. The cross-sectional shape and fiber properties of the yarn are as shown in Table 1, and although the color development was improved compared to the circular cross-section, it was insufficient.

Comparative Example 3 The same procedure as in Example 1 was carried out except that the number of B components was changed to three. The results are shown in Table 1, and although there was an effect of improving color development, it was insufficient.

[0039]

[Table 1]

[0040]

[Effects of the Invention] The method of the present invention can provide grooves with high accuracy in the fiber axis direction in order to exhibit high coloring properties. Color development can be greatly improved by specifying the cross-sectional shapes of grooves and protrusions without adding post-processing techniques to improve color properties. Color development can be further improved by subjecting the fibers obtained in the present invention to post-processing treatment for improving color development. Therefore, it has the advantage that there are very few restrictive conditions and can be applied to a wide range of applications. In addition, since the fibers obtained by the present invention form continuous grooves in the fiber axis direction, they have a great water absorption effect, and furthermore, because they have many grooves, the fibers obtained by the present invention are used. The fabric has a crisp feel and is useful as a refreshing material.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of a fiber obtained by the present invention.

FIG. 2 is a cross-sectional view showing an example of a two-component composite yarn of the present invention before dissolution treatment.

FIG. 3 is a graph showing the relationship between the width of grooves in polyester fibers and the L value (color development) when dyed black.

[Figure 4] L versus groove depth in polyester fiber
It is a graph showing the relationship between values (color development).

FIG. 5 is a graph showing the relationship between the ratio of the total width of grooves to the total circumferential length of polyester fibers and the L value (color development).

FIG. 6 is an enlarged cross-sectional view of a part of FIG. 2 for explaining the shape of the two-component composite yarn according to the present invention.

FIG. 7 is an enlarged cross-sectional view of a portion of FIG. 1 for explaining the shape of fibers obtained by the present invention.

[Explanation of symbols]

1: Fiber 2:Protrusion 3: Groove A: Hardly soluble component B: Easily eluted component

Claims (1)

[Claims] Claim 1: By dissolving a two-component composite yarn in which the A component divides the B component into four or more parts, the B component is mainly eluted and four or more continuous grooves are provided in the fiber axis direction. In the method, the width c of the B component at the composite yarn stage,
A groove in which the relationship between the dissolution rate ratio S of component B to component A and the width w of the groove after dissolution satisfies the following formula, and the total width w of the groove is controlled to be 0.1 or more of the total circumference of the fiber. 1. A method for producing synthetic fibers with good color development, characterized by imparting the following properties. c+(5/S)-0.5≦w≦c+(15
/S)+1.0 where the units of c and w are μm.