JP2019049088A - Potential trachychromatic polyester fiber, trachychromatic polyester fiber, method for producing trachychromatic polyester fiber, and woven knitted fabric - Google Patents

Abstract

To provide a potential trachychromatic polyester fiber excellent in trachychromatic properties and a worsted tone feeling.SOLUTION: Provided is a potential trachychromatic polyester fiber made of a polyester resin composition including a polyester resin and generation particles. The polyester resin includes a diethylene glycol component by 6.0 to 10.0 mol%, and the generation particles are derived from a phosphorous compound and an alkaline-earth metal compound or derived from a phosphorous compound, an alkaline-earth metal compound and an alkaline-earth metal compound.SELECTED DRAWING: Figure 2

Description

  The present invention is excellent in deep dyeability at the time of dyeing after performing alkali reduction treatment, latent thick dyeable polyester fiber having a wool-like texture, excellent in deep dyeability at the time of dyeing, and deep dye having a wool-like texture. Polyester fiber, and a method for producing a deep dyed polyester fiber. Further, the present invention relates to a woven or knitted fabric containing a deep dyeing polyester fiber.

  Polyester fibers are widely used in clothing or industrial applications due to their excellent properties such as heat resistance or mechanical properties. However, polyester fibers may be inferior in deep dyeability when dyed because the fiber structure is strong. Therefore, various methods have been proposed to improve the deep dyeability of polyester fibers. For example, in Patent Document 1, a polyester fiber contains inactive fine particles (for example, fine silica particles), is subjected to an alkali reduction treatment to remove the inactive fine particles, and forms fine unevenness on the surface of the fiber. Techniques for expressing sex have been described.

  Further, in Patent Document 2, in order to obtain a polyester fiber having enhanced deep dyeability, a specific amount of metal is added to a synthetic system of a polyester resin composition instead of containing inert fine particles in the polyester fiber. Techniques have been described for the addition of compounds (eg calcium acetate) and certain phosphorus compounds to form particles. The polyester resin composition is spun to obtain polyester fibers, and the particles are removed by, for example, alkali reduction treatment to form fine irregularities on the surface of the fibers.

Japanese Patent Application Laid-Open No. 55-107512 JP, 2011-063646, A

  However, in the technology described in Patent Document 1, there is a problem that the deep dyeability of the polyester fiber is not sufficient, and furthermore, the commercial value or productivity is reduced due to the occurrence of fuzz or thread breakage at the time of spinning. Moreover, even if the technique described in Patent Document 2 is used, the shape of the unevenness present on the fiber surface becomes an elongated groove shape, and it is difficult to achieve sufficient deep dyeability. In addition, fibers having deep dyeing properties suitable for black formal clothing applications etc. have a texture such as wool tone which is a natural fiber (in the present invention, when it is referred to as “eyebrow-like texture”) in order to improve the sense of luxury. In the above-mentioned patent documents, there is still room for improvement in the eyebrow-like texture. Here, as a method for improving the flagellar texture of the deep-dyed polyester fiber, for example, there is known a method for expressing the flagellum tone by a combination of differential shrinkable fibers, etc. However, by devising the polyester fiber itself There is still no known method for simultaneously expressing deep staining and eyebrow tone. The object of the present invention is to improve the problems of the prior art and to obtain a dark dyeable polyester fiber having a dark dyeability at the time of dyeing and an eyebrow-like texture.

In order to solve the above-mentioned problems, the present inventors, in addition to the relationship between the fine pores formed on the monofilament surface of the deep dyeing polyester fiber and the deep dyeing property, the concentration by the diethylene glycol content in the polyester fiber The effects of staining were examined. As a result, by containing a specific amount of diethylene glycol in the fiber, the solubility of the polyester fiber in the basic compound is improved, the alkali dissolution rate (alkali loss rate) is promoted, and the fiber surface derived from the produced particles The fine pores become coarse and fine and have a large depth, and when dyed, they are not only excellent in deep dyeability suitable for black formal clothing applications, etc. but also characteristic of microfibrils on the wool surface It turned out that it can achieve a wool-like texture (eyebrow-like texture) by becoming fine pores, and completed the present invention. Furthermore, it has been found that micropores having a specific size and depth are present in a specific number (at a high density) on the surface of a single fiber, and it is possible to achieve even better deep dyeing, thus completing the present invention. Furthermore, the cross-sectional shape is even more excellent in that it has projections and narrow grooves alternately and is substantially uniform, and the cross sections of the projections and narrow grooves have a rectangular or substantially trapezoidal shape. Having found that deep staining can be achieved, the present invention has been completed.
That is, the present invention provides the following (1) to (12) as the gist.

(1) A latently dyeable polyester fiber comprising a polyester resin composition containing a polyester resin and product particles, wherein the polyester resin contains 6.0 to 10.0 mol% of a diethylene glycol component, and the product particles contain A latently dyeable polyester fiber which is derived from a phosphorus compound and an alkaline earth metal compound or is derived from a phosphorus compound and an alkali metal compound and an alkaline earth metal compound.
(2) The latently dyeable polyester fiber according to (1), wherein the average particle diameter of the produced particles is 0.05 to 0.5 μm.
(3) The alkaline dissolution rate per unit surface area in an aqueous solution having a temperature of 98 ° C. and a concentration of a basic compound of 2% by mass is 10.0 g / (min · m ² ) or more, (1) or (2) ) Latently dyeable polyester fiber.

(4) A latently dyed core-sheath composite polyester fiber comprising a polyester resin composition disposed in the core and a highly soluble polyester resin disposed in the sheath, wherein the polyester resin composition comprises the polyester resin and the produced particles And the polyester resin contains 6.0 to 10.0 mol% of a diethylene glycol component, and the produced particles are derived from a phosphorus compound and an alkaline earth metal compound, or a phosphorus compound and an alkali metal The core portion is derived from a compound and an alkaline earth metal compound, and in the cross section perpendicular to the fiber axial direction of the single fiber, the shape of the core portion is a modified cross-sectional shape having a protrusion and a groove, A latently dyed core-sheath composite polyester fiber, wherein the groove has a rectangular or substantially trapezoidal cross-sectional shape, and the number of projections is 10-32.

(5) The latently dyed core-sheath composite polyester fiber according to (4), wherein the average particle diameter of the produced particles is 0.05 to 0.5 μm.
(6) The alkaline dissolution rate per unit surface area is 10.0 g / (min · m ² ) or more in an aqueous solution in which the core has a temperature of 98 ° C. and the concentration of the basic compound is 2% by mass 4) or latent dyed core-sheath composite polyester fiber of (5).

(7) A concentrated dyed polyester fiber having micropores on the surface of a single fiber and made of a polyester resin, wherein the polyester resin contains 6.0 to 10.0 mol% of a diethylene glycol component, and the micropores are The number is 15 or more in the 5 μm × 5 μm area on the surface of the single fiber, the major axis length is 0.9 μm or less, the minor axis length is 0.6 μm or less, and the depth is A deep dyed polyester fiber which is 250 to 800 nm.

(8) The single fiber is a modified cross-section fiber in which protrusions and narrow grooves are alternately and almost uniformly distributed on the surface,
The cross-sectional shape of the projection and the narrow groove is rectangular or substantially trapezoidal, and the projection and the narrow groove are each continuous in the fiber axis direction,
The deep dyeable polyester fiber according to (7), wherein the number or size of the protrusions satisfies the following (I) to (III).
10 <N <32 (I)
0.3 ≦ W ≦ 2.0 (II)
0.5 W ≦ H ≦ 3.0 W (III)
However, N is the number of protrusions, W is the width (μm) of the protrusions, and H is the height (μm) of the protrusions.
(9) The deep-dyeing polyester fiber of (7) or (8) having an L value of 13.0 or less when subjected to black dyeing as a tubular knitted fabric.

(10) A process for producing a deep dyeing polyester fiber according to (7) or (9), which comprises esterification reaction of a dicarboxylic acid component and a diol component to produce a polyester oligomer, and the polyester oligomer Together with a phosphorus compound and an alkaline earth metal compound, or with a phosphorus compound and an alkali metal compound and an alkaline earth metal compound, and with addition of diethylene glycol, followed by a polycondensation reaction to obtain a polyester resin composition A dark dyed polyester comprising the steps of: obtaining a waste; spinning the polyester resin composition to obtain a latent deep dyeing polyester fiber; and subjecting the latent deep dyeing polyester fiber to alkali reduction treatment How to make fiber.

(11) A process for producing a deep dyeing polyester fiber according to (8) or (9), which comprises esterification reaction of a dicarboxylic acid component and a diol component to form a polyester oligomer, and the polyester oligomer Together with a phosphorus compound and an alkaline earth metal compound, or with a phosphorus compound and an alkali metal compound and an alkaline earth metal compound, and with addition of diethylene glycol, followed by a polycondensation reaction to obtain a polyester resin composition In the process of obtaining the product, composite spinning is performed so that the polyester resin composition is disposed in the core and the easily soluble polyester resin is disposed in the sheath, and the core in the cross section perpendicular to the longitudinal direction of the fiber has protrusions and A latently dyed core-sheath composite polyester having a groove and an irregular cross-sectional shape in which the number of projections is 10 to 32. And a step of obtaining a Wei, a step of subjecting the latent stain resistant core-sheath bicomponent polyester fibers in the caustic treatment, the method for producing a deep dyeing polyester fibers.
(12) A woven or knitted fabric comprising the deep dyeing polyester according to any one of (7) to (9).

  According to the present invention, by containing a specific amount of diethylene glycol in the fiber, the alkali dissolution rate of the polyester fiber to the basic compound is increased, and the fiber surface is compared with the fiber having only micropores by the produced particles. The deep-dyed polyester fiber of the present invention is excellent in deep-dyeing properties (potential deep-dyeing properties) after alkali reduction treatment and has a wool-like texture (flagell-like texture) by making the micropores of the layer deeper and coarser. You can get The deep-dyed polyester fiber of the present invention is more excellent in deep-dyeing properties at the time of dyeing, preferably when fine pores having a specific size and depth are present on the surface of the single fiber, It is possible to obtain a dark dyed polyester fiber which is more excellent and has a wool-like smooth texture when made into a woven or knitted fabric. Furthermore, the cross-sectional shape is characterized by having projections and narrow grooves alternately and approximately uniformly, and the cross sections of the projections and narrow grooves have a rectangular or substantially trapezoidal shape, so that it is possible to It is possible to obtain a further excellent deep dyeable polyester fiber. Furthermore, according to the production method of the present invention, such deep dyeing polyester fibers can be produced with high productivity.

It is a cross-sectional schematic diagram which shows one embodiment of the different-shaped cross section of the single yarn which comprises the latent deep dyeing core-sheath composite polyester fiber of this invention. It is the photograph (magnification; 5000 times) which image | photographed the single fiber surface of the deep dyeing polyester fiber of this invention obtained in Example 3. FIG. It is the photograph (magnification; 5000 times) which image | photographed the monofilament surface of the polyester fiber which has a micropore obtained by the comparative example 1. FIG. It is a cross-sectional schematic diagram which shows one embodiment of the modified cross section of the single yarn which comprises the deep dyeing polyester fiber of this invention. It is the partial expansion schematic diagram in one embodiment of the variant cross section of the single yarn which constitutes the deep dyeing polyester fiber of the present invention.

Hereinafter, the present invention will be described in detail.
[Latent deep dyeing polyester fiber]
The latently dyed polyester fiber of the present invention comprises a polyester resin composition containing a polyester resin and product particles. The polyester resin contains 6.0 to 10.0 mol% of a diethylene glycol component.
The produced particles are derived from a phosphorus compound and an alkaline earth metal compound, or are derived from a phosphorus compound, an alkali metal compound and an alkaline earth metal compound.

  The polyester resin is, for example, a polyester comprising a terephthalic acid component and an ethylene glycol component, wherein 80 mol% or more of all structural units is ethylene terephthalate, and the polyester resin contains 6.0 to 10.0 mol% of diethylene glycol is there. In addition, the polyester resin may be one to which additives such as commonly used additives, matting agents, antistatic agents, antioxidants and the like are added.

  The produced particles are derived from a phosphorus compound and an alkaline earth metal compound, or derived from a phosphorus compound and an alkali metal compound and an alkaline earth metal compound. The alkali metal compound and the alkaline earth metal compound may be simply referred to as a metal compound. In the present invention, latent deep dyeing refers to, for example, deep dyeing developed by applying alkali reduction treatment to a polyester fiber to drop generated particles and forming micropores on the surface of a single fiber.

  The produced particles are different from known inert fine particles such as silica fine particles, and the production steps of the polyester resin composition individually (synthesis reaction system) without reacting the phosphorus compound and the metal compound described later in advance. Is a particle formed by the reaction of the phosphorus compound and the metal compound.

  The average particle diameter of the produced particles is preferably 0.05 to 0.5 μm, more preferably 0.08 to 0.4 μm. When a deep dyeable polyester fiber is obtained by alkali reduction treatment as the average particle diameter is in the above range, the density of fine pores having an appropriate size and depth as described later is increased (number of particles in specific range) No generation of clogged filters or clogged filters is possible without clogging the filter for filtering the molten polymer when spinning polyester fibers. The average particle diameter of the produced particles can be controlled within the above range, for example, by preferably adding the combination of the phosphorus compound and the metal compound or the addition amount of the phosphorus compound and the metal compound. The preferable combination of the phosphorus compound and the metal compound in the present invention, and the preferable addition amount of the phosphorus compound and the metal compound will be described later. In addition, the range of the size, depth, and number of micropores in the present invention will be described later. In the case where known inert fine particles such as silica fine particles are added without using generated particles, the fine particles become coarse due to aggregation, and micropores having an appropriate size and depth are formed with high density. And the effects of the present invention can not be achieved.

  As a phosphorus compound, phosphoric acid, phosphonic acids, or phosphinic acids are mentioned, for example. Among them, aliphatic phosphoric acids are preferable because the average particle size of the produced particles is not too large, and the dyeability (or latent dyeability) of the polyester fiber and the stability of the spinning process become good. Acid esters are more preferred. Among the phosphoric acid esters, triethyl phosphate (triethyl phosphate) is particularly preferable from the viewpoint of excellent deep dyeability.

  The alkali metal compound is, in particular, an alkali metal salt of a carboxylic acid, and specific examples thereof include lithium acetate, sodium acetate, potassium acetate, lithium benzoate, sodium benzoate or potassium benzoate. Among these, lithium acetate is preferable because the average particle diameter of the produced particles is in the optimum range and byproducts can be suppressed during the polymerization reaction of the polyester.

  The alkaline earth metal compounds are, in particular, alkaline earth metal salts of carboxylic acids, and as specific examples thereof, magnesium acetate, calcium acetate, magnesium oxalate, calcium propionate, calcium stearate, magnesium stearate, calcium benzoate Or manganese acetate. In particular, when a magnesium salt of a carboxylic acid is used, it is preferable because the particle diameter of the produced particles formed in the polyester resin does not become excessive and the deep dyeability and the stability of the spinning process of the polyester fiber become good. . Among them, magnesium acetate is particularly preferable because it is excellent in deep dyeability and handleability.

  The preferable combination of the phosphorus compound and the metal compound controls the average particle diameter of the produced particles in the above range, and obtains polyester fibers (concentrated dyeable polyester fibers, thick dyeable polyester fibers) which are remarkably excellent in deep dyeability. Therefore, a combination of a phosphoric acid ester and a metal salt of acetic acid is preferable, more preferably a combination of triethyl phosphate (triethyl phosphate) and magnesium acetate, and it is most preferable to additionally use lithium acetate in addition to these . When lithium acetate is used alone as the metal compound, the produced particles tend to be too coarse. That is, in the present invention, triethyl phosphate (triethyl phosphate) as a phosphorus compound, a metal compound and the like, in order to exert a synergetic effect of controlling the average particle diameter of the produced particles within the above range and significantly improving the deep staining. The combination of magnesium acetate and lithium acetate is most suitable.

  As described above, the polyester resin contains the diethylene glycol component in a proportion of 6.0 to 10.0 mol%, and the proportion of the diethylene glycol component is preferably 6.5 to 9.5 mol%, and 7 It is more preferable that it is 0.5-9.5 mol%, and it is further more preferable that it is 8.0-9.5 mol%. If the diethylene glycol component is less than 6.0 mol%, the alkali dissolution rate described later can not be sufficiently increased, and the deep dyeing polyester fiber after alkali reduction treatment has a sufficient depth, And, it is not possible to form rough fine pores which are sharp. On the other hand, if it exceeds 10.0 mol%, the yarn strength of the obtained fiber is reduced, and there is a problem in processability.

The alkali dissolution rate of the latent deep dyeing polyester fiber can be adjusted by setting the content of diethylene glycol in a specific range. The alkali dissolution rate is preferably 10.0 g / (min · m ² ) or more, and 12.0 g / (min · m ² ) in an aqueous solution having a temperature of 98 ° C. and a concentration of a basic compound of 2% by mass. The content is more preferably 13.0 g / (min · m ² ) or more. When the dissolution rate is in such a range, when an alkali reduction treatment is performed as described later, it is possible to obtain a deep-dyed polyester fiber which is excellent in deep-dyeing properties and eyebrow-like texture. The reason will be described in detail later. The measurement method of the alkali dissolution rate will be described later in Examples.

[Latent dark dyeable core-sheath composite polyester fiber]
The latent deep-dyeing core-sheath composite polyester fiber of the present invention is obtained by arranging the polyester resin composition in the core portion and arranging the easily soluble polyester resin in the sheath portion. The polyester resin composition comprises a polyester resin and product particles. The polyester resin contains 6.0 to 10.0 mol% of a diethylene glycol component. The produced particles are derived from a phosphorus compound and an alkaline earth metal compound, or are derived from a phosphorus compound, an alkali metal compound and an alkaline earth metal compound.

  Furthermore, in the cross section perpendicular to the fiber axis direction of the single fiber, the shape of the core is a modified cross-sectional shape having a protrusion and a groove, and the cross-sectional shape of the protrusion and the groove is rectangular or substantially trapezoidal. The number of protrusions is 10-32.

  As shown in FIG. 1, the latent deep-dyeing core-sheath composite polyester fiber 1 of the present invention is such that the polyester resin composition 3 is disposed in the core portion and the easily soluble polyester resin 2 is disposed in the sheath portion . And the shape of the core part in the cross section perpendicular | vertical to the fiber axial direction of a single fiber is a deformed cross-sectional shape which has ten to 32 protrusion parts and a groove | channel. Between the adjacent protrusions, there are the same number of grooves as the number of protrusions. In the present invention, the term "soluble" means that elution by a basic compound (alkali) is easy. In the latently dyed core-in-sheath composite polyester fiber of the present invention, the shape of the core portion is substantially the cross-sectional shape of the dark dyed polyester fiber having a modified cross-section which is a preferred embodiment of the present invention. Is identical to This is because the sheath portion of the latent deep-dyeing core-sheath composite polyester fiber of the present invention is eluted with a basic compound (alkali), and further, the core portion surface is eluted to drop out the produced particles. It is for obtaining a deep dyeing polyester fiber.

  The easily soluble polyester resin 2 is preferably one having a dissolution rate to a solvent such as an alkali five times or more faster than the polyester resin 3 described later. Therefore, the easily soluble polyester resin is an aromatic dicarboxylic acid component in which 1 to 3 mol% of the dicarboxylic acid component has a sulfonate group, and contains 5 to 15 mass% of polyalkylene glycol having an average molecular weight of 1000 to 10000. Is preferred.

  As an aromatic dicarboxylic acid component having a sulfonate group, 5-sodium sulfoisophthalic acid, 5-sodium sulfoterephthalic acid, 5-potassium sulfoisophthalic acid, 5-sodium sulfoterephthalic acid, 5-lithium sulfoisophthalic acid, 5- Examples include phosphonium sulfoisophthalic acid and the like. When the aromatic dicarboxylic acid component having a sulfonate group is 1 mol% or more of the dicarboxylic acid component, the dissolution rate with respect to alkali is sufficiently fast. If it is 3 mol% or less, the spinning property is better even at high speeds, and troubles such as thread breakage can be suppressed.

  The polyalkylene glycol preferably has an average molecular weight of 1,000 to 10,000. When the average molecular weight is 1000 or more, the glass transition point of the easily soluble polyester resin A does not decrease, and fusion does not easily occur in the spinning process. If it is 10000 or more, the compatibility is good and it is easy to be contained uniformly.

  When the polyalkylene glycol content is 5% by mass or more, the dissolution rate with respect to alkali is sufficiently fast. If the content is 15% by mass or less, the spinning property is improved while maintaining the dissolution rate sufficiently high, and troubles such as thread breakage can be suppressed in the spinning process.

  The polyester resin composition contains a polyester resin and product particles of a specific size.

  The polyester resin is, for example, a polyester comprising a terephthalic acid component and an ethylene glycol component, wherein 80 mol% or more of all structural units is ethylene terephthalate, and the polyester resin contains 6.0 to 10.0 mol% of diethylene glycol is there. Further, in the polyester resin, a commonly used additive, a matting agent, an antistatic agent, an antioxidant and the like may be added.

  The produced particles are different from known inactive fine particles such as silica fine particles as the generated particles in the latent densely dyeable polyester fiber described above, and the below-mentioned phosphorus compound and metal compound are not reacted in advance. By separately adding them to the production stage (synthetic reaction system) of the polyester resin composition, the particles are formed by the reaction of the phosphorus compound and the metal compound. In the present invention, with the latent deep dyeing property, the core-sheath composite polyester fiber as described above is subjected to alkali reduction treatment to elute the sheath portion, and the core portion surface is eluted to dislodge generated particles. , Includes deep-dyeing properties developed by forming micropores on the surface of single fibers.

  The average particle diameter of the produced particles is preferably 0.05 to 0.5 μm, more preferably 0.08 to 0.4 μm. When a deep dyeable polyester fiber is obtained by alkali reduction treatment as the average particle diameter is in the above range, the fine pores having an appropriate size and depth as described later are high density (number of particles within a specific range) It becomes a product particle that can be formed, and it is possible to suppress an increase in pressure or occurrence of thread breakage without clogging of a filter for filtering a molten polymer when spinning a latent deep-dyeing core-sheath composite polyester fiber . The average particle diameter of the produced particles can be controlled within the above range, for example, by preferably adding the combination of the phosphorus compound and the metal compound or the addition amount of the phosphorus compound and the metal compound. The preferable combination of the phosphorus compound and the metal compound in the present invention, and the addition amount of the phosphorus compound and the metal compound will be described later. In addition, the range of the size, depth, and number of micropores in the present invention will be described later. In the case where known inert fine particles such as silica fine particles are added without using generated particles, the fine particles become coarse due to aggregation, and micropores having an appropriate size and depth are formed with high density. And the effects of the present invention can not be achieved.

  As a phosphorus compound, phosphoric acid, phosphonic acids, or phosphinic acids are mentioned, for example. Among them, aliphatic phosphoric acids are preferable because the average particle size of the produced particles is not too large, and the dyeability (or latent dyeability) of the polyester fiber and the stability of the spinning process become good. Acid esters are more preferred. Among the phosphoric acid esters, triethyl phosphate (triethyl phosphate) is particularly preferable from the viewpoint of excellent deep dyeability.

  The alkali metal compound is, in particular, an alkali metal salt of a carboxylic acid, and specific examples thereof include lithium acetate, sodium acetate, potassium acetate, lithium benzoate, sodium benzoate or potassium benzoate. Among these, lithium acetate is preferable because the average particle diameter of the produced particles is in the optimum range and byproducts can be suppressed during the polymerization reaction of the polyester.

  The alkaline earth metal compounds are, in particular, alkaline earth metal salts of carboxylic acids, and as specific examples thereof, magnesium acetate, calcium acetate, magnesium oxalate, calcium propionate, calcium stearate, magnesium stearate, calcium benzoate Or manganese acetate. In particular, when a magnesium salt of a carboxylic acid is used, the particle diameter of the produced particles formed in the polyester resin does not become excessive, and in the process of spinning the concentrated / latent dark / dye core / sheath composite polyester fiber It is preferable because the stability is improved. Among them, magnesium acetate is particularly preferable because it is excellent in deep dyeability and handleability.

  The preferable combination of the phosphorus compound and the metal compound controls the average particle diameter of the produced particles in the above range, and polyester fiber (the latent dyeable core-sheath composite polyester fiber, the dark dyeable polyester fiber) which is remarkably excellent in the deep dyeability From the viewpoint of obtaining a combination of a phosphoric acid ester and a metal salt of acetic acid, more preferably a combination of triethyl phosphate (triethyl phosphate) and magnesium acetate, and additionally using lithium acetate in addition to these Is most preferred. When lithium acetate is used alone as the metal compound, the produced particles tend to be too coarse. That is, in the present invention, triethyl phosphate (triethyl phosphate) as a phosphorus compound, a metal compound and the like, in order to exert a synergetic effect of controlling the average particle diameter of the produced particles within the above range and significantly improving the deep staining. The combination of magnesium acetate and lithium acetate is most suitable.

  As described above, the polyester resin contains the diethylene glycol component in a proportion of 6.0 to 10.0 mol%, and the proportion of the diethylene glycol component is preferably 6.5 to 9.5 mol%, and 7 It is more preferable that it is 0.5-9.5 mol%, and it is further more preferable that it is 8.0-9.5 mol%. If the diethylene glycol component is less than 6.0 mol%, the alkali dissolution rate described later can not be sufficiently increased, and the deep dyeing polyester fiber after alkali reduction treatment has a sufficient depth, And, it is not possible to form rough fine pores which are sharp. On the other hand, if it exceeds 10.0 mol%, the yarn strength of the obtained fiber is reduced, and there is a problem in processability.

The alkali dissolution rate of the core polyester resin can be adjusted by setting the content of diethylene glycol in a specific range. The alkali dissolution rate is preferably 10.0 g / (min · m ² ) or more, and 12.0 g / (min · m ² ) in an aqueous solution having a temperature of 98 ° C. and a concentration of a basic compound of 2% by mass. The content is more preferably 13.0 g / (min · m ² ) or more. When the dissolution rate is in such a range, when an alkali reduction treatment is performed as described later, it is possible to obtain a deep-dyed polyester fiber which is excellent in deep-dyeing properties and eyebrow-like texture. The reason will be described in detail later. The measurement method of the alkali dissolution rate will be described later in Examples.

  Although the composite ratio (mass ratio) of the core and the sheath is not particularly limited, for example, from the balance with the strength, the ease of alkali reduction, etc., the sheath: core = 5: 95 to 40 : In the range of 60.

  In the latently dyed core-sheath composite polyester fiber, micropores (irregular shape on the surface of the monofilament) are generated when the generated particles having the above-described average particle diameter are reduced by alkali by the basic compound on the monofilament surface. Can be the deep-dyed polyester fiber of the present invention, which is a modified cross-section fiber in which protrusions and grooves are alternately and almost uniformly distributed on the surface. The sectional shape of the above-mentioned projection and groove is rectangular or substantially trapezoidal, and both are continuous in the fiber axis direction.

[Dense dyeable polyester fiber]
The deep-dyeing polyester fiber of the present invention is a deep-dyeing polyester fiber having micropores on the surface of a single fiber and comprising a polyester resin containing 6.0 to 10.0 mol% of a diethylene glycol component. The number of the micropores is 15 or more in a 5 μm × 5 μm size area on the surface of the single fiber, the major axis length is 0.9 μm or less, and the minor axis length is 0.6 μm or less And the depth is preferably 250 to 800 nm.

  The deep dyeing polyester fiber of the present invention can be obtained by reducing the alkali of the latent deep dyeing polyester fiber of the present invention described above.

  FIG. 2 is a photograph of the monofilament surface of the deep-dyed polyester fiber of the present invention obtained in Example 3, and FIG. 3 is a photograph of the monofilament surface of the polyester fiber obtained in Comparative Example 1. It is. The polyester fiber of Comparative Example 1 was obtained by the same method as Example 3 except that a polyester resin not containing diethylene glycol was used. As can be understood from the comparison between FIG. 2 and FIG. 3, the produced particles and the specific amount as compared with the polyester fiber obtained using the polyester resin (FIG. 3) having produced particles but not containing diethylene glycol In the deep-dyed polyester fiber of the present invention (FIG. 2) simultaneously satisfied with a polyester resin containing diethylene glycol (FIG. 2), the micropores become rougher on the monofilament surface after the alkali reduction treatment, The depth is greater. As a result of intensive investigations by the present inventors, the reason for this is that the polyester resin is more preferably a specific range to improve the solubility in a basic compound, specifically to accelerate the alkali dissolution rate, by containing diethylene glycol. The size and the number of particles, and the formation of fine fine holes such as fine, is excellent in dark dyeability at the time of dyeing to further promote multiple scattering of incident light as described later, It has been found that it is possible to obtain a textured deep-dyed polyester fiber.

  The relationship between micropores and deep dyeability in deep dyeable polyester fibers is described below. Usually, when light is incident on the surface of the polyester fiber, glare occurs due to the reflection of the incident light, and it is not possible to express a deep color tone or sufficient deep dyeability. However, in the present invention, due to the presence of fine pores of a specific size and depth at a high density, reflected light is reflected on the fiber surface after repeated scattering and re-scattering when incident light is reflected on the single fiber surface. Re-incident light can increase the light absorbed in the fibers. That is, the incident light can be multiple-scattered to the fiber surface to reduce the reflected light, thereby exhibiting excellent deep dyeability and deep color tone.

  The relationship between the micropores and the texture of the eyebrows in the deep-dyed polyester fiber is described below. Heretofore, in polyester fibers having micropores on the surface of monofilaments, the micropores have a small depth and a regular size. However, in the present invention, the fine pores having a specific size and depth, and having a high density of fine pores whose surface is roughened, become a surface having fibril-like fine pores characteristic of wool. As a result, it is possible to obtain a deep dyed polyester fiber excellent in eyebrow-like texture.

  In order to promote multiple scattering of incident light to enhance deep dyeability, fineness in size and depth of the size and depth appropriately correspond to the wavelength of visible light (380 to 780 nm) on the single fiber surface of deep dyed polyester fiber It is necessary for the holes to be present at a high density. In order to achieve the size and depth of such fine pores, it is preferable to set the average particle size of the produced particles of the latent deep dyeing polyester fiber in the above range. Specifically, the micropores preferably have a major axis of 0.9 μm or less and a minor axis of 0.6 μm or less, and the major axis is 0.3 to 0.9 μm and the minor axis is 0.1 to 0.6 μm. More preferably, the major axis is 0.4 to 0.8 μm and the minor axis is 0.2 to 0.4 μm. Furthermore, the formation of micropores of such a size can improve the eyebrow-like texture.

  Furthermore, in order to promote multiple scattering of incident light and to realize the eyebrow tone texture, it is preferable that the number of micropores is 15 or more in a 5 μm × 5 μm size area on a single fiber surface, It is more preferable to exist in a number of pieces or more. The upper limit of the number of micropores in the 5 μm × 5 μm region is not particularly limited, but is about 100, and the number of micropores is more preferably 70 or less, still more preferably 50 or less.

  Furthermore, in order to promote multiple scattering of incident light and to realize the eyebrow-like texture, the depth of the micropores is preferably 250 to 800 nm, and more preferably 400 to 800 nm. If the micropore depth is less than 100 nm, multiple scattering can not be promoted. In addition, even if the depth is 250 nm or more, if the size and the number of the micropores do not satisfy the range defined in the present invention, the dyeability and the texture of eyebrows are inferior. In addition, the depth of a micropore is a value measured in the location where the distance from the single fiber surface is the largest.

  As a result of intensive investigations by the present inventors, the addition of diethylene glycol in the polyester fiber increases the depth of the micropores and further makes the micropores coarser, thereby providing more excellent dyeability and an eyebrow-like texture. It has been found that a polyester fiber having the Although the reason is not clear, the present inventors speculate as follows. That is, by setting the content of diethylene glycol in the specific range, the crystallinity of the polyester resin is reduced, the alkali dissolution rate is increased, and the coarser fine pores having a large depth are obtained. Further, it is considered that diethylene glycol lowers the crystallinity, so that the amorphous part in the polyester fiber is increased and the dye adsorption property is improved. The present invention is due to these two synergistic effects. Furthermore, by containing diethylene glycol in a specific range, the dyeing speed can be increased and the productivity can be improved.

  That is, as described above, the concentrated polyester fiber of the present invention promotes the dissolution rate of alkali by containing a specific amount of diethylene glycol, and increases the depth of the micropores formed after the alkali reduction treatment, Further, by setting the size, number and depth of the micropores at the same time in a specific range, the incident light is multi-scattered to reduce the reflected light, which is remarkable. It can develop excellent deep-dyeing and eyebrow-like texture.

Furthermore, it is preferable that the single yarn which comprises the deep dyeing polyester fiber of this invention is a cross-sectional shape as follows. That is, a single fiber is a modified cross-section fiber in which protrusions and fine grooves are alternately and almost uniformly distributed on the surface, and the cross-sectional shape of the protrusions and the fine grooves is rectangular or substantially trapezoidal. The thin grooves are each continuous in the fiber axis direction, and the number or size of the protrusions preferably satisfy the following (I) to (III).
10 <N <32 (I)
0.3 ≦ W ≦ 2.0 (II)
0.5 W ≦ H ≦ 3.0 W (III)
However, N is the number of protrusions, W is the width (μm) of the protrusions, and H is the height (μm) of the protrusions.

  With the cross-sectional shape as described above, the light incident in the narrow groove causes the light scattering on the surface of the fiber to cause multiple scattering in order to cause multiple scattering of the ridges on both sides. The deep dyeing effect is further enhanced.

The preferable cross-sectional shape of the deep dyeing polyester fiber will be described below using FIG.
As shown in FIG. 4, the deep dyeing polyester fiber A has a protrusion B and a groove C.
The number (N) of the protrusions B after the alkaline elution treatment is preferably 10 to 32 on the circumference of the fiber, more preferably 14 to 30 and still more preferably 16 to 25. preferable. When the number is 10 or more, fine grooves for generating multiple scattering are sufficiently present, and the deep dyeing effect is excellent. When the number is 32 or less, fibrillation is difficult and the deep dyeing effect is excellent.

  The relationship between the width W and the height H of the protrusion will be described below. FIG. 5 is a partially enlarged cross-sectional view of the protrusion and the narrow groove in the deep-dyed polyester fiber of the present invention. In FIG. 5, the line on the side surface of the protrusion is extended, and the intersection points of the circumscribed circles of the apexes of the protrusions are 4 and 5, respectively. And let the intersection of the inscribed circle of the deepest part of a thin groove part be 4 ', 5', respectively. Further, middle points of the line segment 4-5 and the line segment 4'-5 'are set to 6, 6' respectively. And let the length of line segment 4-5 be width W of a projection part. The length of the line segment 6-6 'is taken as the height H of the projection.

  The width W of the protrusions is preferably 0.3 to 2 μm, more preferably 0.4 to 1.7 μm, and still more preferably 0.6 to 1.5 μm. When the width W of the protrusions is 0.3 μm or more, fibrillation is difficult as in the case where the number of protrusions is reduced, and the deep dyeing effect is excellent. Further, if the thickness is 2.0 μm or less, the width of the protrusion does not become excessively wide, and the incident light to the narrow groove can be sufficiently secured, so that the deep dyeing effect is excellent.

  The height H of the projection is set in close association with the width W of the projection. Specifically, the width W of the projection is preferably in the range of 0.5 to 3 times, more preferably 0.7 to 2.5 times, and more preferably 1.5 to 2.0 times. Is more preferred. If the height H of the projection is 0.5 or more times the width W, the depth of the narrow groove will not be too shallow and multiple scattering will be sufficiently generated, resulting in a poor deep dyeing effect. Moreover, since a projection part does not become large too much that it is 3.0 times or less and it becomes difficult to generate fibrillation, it is excellent in the deep dyeing effect.

  Since the deep-dyed polyester fiber of the present invention is excellent in deep-dyeability, the L value when subjected to black dyeing after being formed into a tubular knit fabric is preferably 13.0 or less, and is 12.5 or less Is more preferable, and 12.0 or less is more preferable. Details of the method of measuring the L value will be described later in the examples.

  The single-fiber fineness of the deep-dyeing polyester fiber is preferably fine because it is excellent in eyebrow color texture, and is preferably 0.3 dtex or more and 5 dtex or less, for example. Further, the cross-sectional shape of the deep-dyed polyester fiber is not particularly limited, and may be a round cross-sectional shape, and various different cross-sectional shapes (for example, polygonal shapes such as triangles and quadrilaterals, or those having a plurality of projections etc. Although it is not particularly limited, as described above, it is preferable to have a modified cross section having projections of a specific number and a specific size, from the viewpoint of being more excellent in deep dyeability.

The method for producing the deep-dyed polyester fiber of the present invention will be described below.
(First production method)
According to the first production method of the present invention, the step of esterifying a dicarboxylic acid component and a diol component to produce a polyester oligomer (step (I)), a phosphorus compound and an alkaline earth metal are used in the polyester oligomer. A step of adding a compound or adding a phosphorus compound and an alkali metal compound and an alkaline earth metal compound, and adding diethylene glycol and then performing a polycondensation reaction to obtain a polyester resin composition (step (step (step II), a step of spinning the polyester resin composition to obtain a latent deep dyeing polyester fiber (step (III)), and a step of subjecting the latent deep dyeing polyester fiber to alkali reduction treatment (step (IV) And). As described above, in the present specification, an alkali metal compound and an alkaline earth metal compound may be referred to as a metal compound.

<Step (I)>
Terephthalic acid can be mainly used as the dicarboxylic acid component. Other components may be copolymerized according to the purpose, as long as the effects of the present invention are not impaired. As components other than terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 5-sodium sulfoisophthalic acid, 5-tetrabutylphosphonium sulfoisophthalic acid, 4,4'-biphenyldicarboxylic acid, p-hydroxybenzoic acid, adipine Acids, sebacic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-cyclohexyldicarboxylic acid and the like can be mentioned.

  Ethylene glycol can be mainly used as the diol component. Other components may be copolymerized according to the purpose, as long as the effects of the present invention are not impaired. As components other than ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,2-propylene glycol, 2,2-dimethyl-1,3-propanediol (neopentylene glycol), dipropylene Examples include glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dimethylolpropionic acid, poly (ethylene oxide) glycol, or poly (tetramethylene oxide) glycol.

  In step (I), a polyester oligomer is obtained by subjecting a dicarboxylic acid component (a dicarboxylic acid containing terephthalic acid as a main component) and a diol component (a diol containing ethylene glycol as a main component) to an esterification reaction. Here, a polyester oligomer includes a dicarboxylic acid component and a diol component, and in the case of terephthalic acid and ethylene glycol, respectively, bis (2-hydroxyethyl) terephthalate, and further, in one molecule, the repeating unit of ethylene terephthalate is 2 And a compound having an intrinsic viscosity, molecular weight and degree of polymerization which has not yet been raised to the extent that it can be called polyethylene terephthalate, and which has a carboxyl group or a hydroxyethyl group at its end. The esterification reaction can be carried out, for example, at a temperature of 250 ° C. for 3 to 8 hours until such polyester oligomers are formed. In order to detect the reaction rate of the esterification reaction, the amount of water produced can be measured.

  Examples of polyester oligomers include polymellitic carboxylic acids such as trimellitic acid, trimesic acid, trimellitic acid anhydride, pyromellitic acid, trimellitic acid monopotassium salt, glycerin, pentaerythritol, sodium dimethylol ethyl sulfonate, potassium dimethylol propionate And the like may be copolymerized within the scope of achieving the object of the present invention.

<Step (II)>
Diethylene glycol and a metal compound and a phosphorus compound are added to the above polyester oligomer, and then a polycondensation reaction is performed to obtain a polyester resin composition. In the step (II), a reaction of the phosphorus compound and the metal compound occurs together with the polycondensation reaction to form the above-mentioned product particles which are insoluble in the polyester resin.

  Regarding the addition order of the phosphorus compound and the metal compound, the phosphorus compound may precede the phosphorus compound, or the phosphorus compound may be added, or the phosphorus compound and the metal compound may be mixed and simultaneously added.

The amount of the metal compound added is preferably 10 × 10 ^{−4 to} 100 × 10 ⁻⁴ mol, more preferably 30 × 10 ⁻⁴ to 80 × 10 ⁻⁴ mol, per 1 mol of the acid component constituting the polyester. It is a mole. If the content is 10 × 10 ^-4 or more, product particles of a size sufficient to improve the deep dyeing properties and the eyebrow color texture of polyester fibers can be formed, and the deep dyeing on the polyester fiber surface is possible It is possible to develop the above-mentioned number of micropores necessary to improve the sex and the eyebrow tone. Since generation of coarse particles can be suppressed to 100 × 10 ⁻⁴ mol or less, clogging of the filter for filtering the molten polyester resin composition does not occur during spinning, and stability of the polyester fiber spinning process Can be kept good.

The amount of the phosphorus compound added is preferably 10 × 10 ^{−4 to} 100 × 10 ⁻⁴ mol, more preferably 20 × 10 ^{−4 to} 90 × 10 ⁻⁴ mol, per 1 mol of the acid component constituting the polyester. It is a mole. If the content is 10 × 10 ⁻⁴ mol or more, product particles of a size sufficient to improve the deep dyeability and the eyebrow color texture of the polyester fiber can be formed, and the deep dye on the polyester fiber surface It is possible to develop the above-mentioned number of micropores necessary to improve the sex and the eyebrow tone. Since generation | occurrence | production of coarse production particle | grains can be suppressed as it is 100 * 10 <^-4> mol or less, clogging of the filter which filters the polyester resin composition which fuse | melted does not generate | occur | produce at the time of spinning. The stability can be kept good. The molar ratio between the metal compound and the phosphorus compound is preferably (metal compound) / (phosphorus compound) = 0.5 to 1.5 in order to obtain excellent spinning stability and latent deep dyeing property.

  The addition amount of diethylene glycol is 5.5 to 9 in consideration of diethylene glycol by-produced at the time of reaction in order to set the content of diethylene glycol in the polyester resin constituting the polyester fiber to the above-mentioned range (6 to 10 mol%). It is preferably 0.5 mol%, more preferably 7.5 to 9.5 mol%, and still more preferably 8.5 to 9.5%. It is more preferable that the addition amount of diethylene glycol is within the specified range. An alkali dissolution rate improves that it is 5.5 mol% or more, and the fiber which is excellent in deep dyeing property and eyebrows color texture can be obtained. Moreover, a fiber favorable in processability is obtained, without reducing the intensity | strength of the yarn obtained as it is 9.5 mol% or less. Either of the addition of diethylene glycol and the addition of the metal compound may precede the other.

  Then, a polycondensation catalyst (for example, an ethylene glycol solution) is added to carry out a polycondensation reaction to obtain a polyester resin composition. In the polycondensation reaction system, if necessary, an additive such as a copolymerizable monomer or an anti-coloring agent may be added as an ethylene glycol solution or a dispersion. In this case, the polycondensation reaction is started by distilling off ethylene glycol (removing ethylene glycol under reduced pressure), and the reaction is carried out while distilling off, and then the strand is removed by a conventional method to form a chip. it can. Here, the formation of product particles is started after the polycondensation catalyst is added. And as the solution is distilled off, the solubility of the product decreases and this product precipitates out as particles.

  The intrinsic viscosity (inherent viscosity) of the polyester resin composition is preferably 0.5 to 1.5 dL / g. When the intrinsic viscosity is in this range, the physical properties of the polyester fiber obtained by spinning the resin composition do not decrease, and the polyester resin composition or the polyester fiber is easily produced.

<Step (III)>
As a multifilament yarn, a known spinning method (for example, melt spinning method) is adopted, a preferable spinning nozzle is selected, and the polyester resin composition obtained in step (II) is spun (for example, melt spinning) To obtain a latent deep dyeing polyester fiber of The film may be wound after being wound as an undrawn yarn by a known method, or may be wound after being drawn without being wound once after discharge. In addition, after winding at a speed of 3000 to 9000 m / min, it may be used for yarn processing or weaving / knitting without stretching separately, or after stretching for yarn processing or weaving / knitting May be

  Spinning conditions are not particularly limited. For example, the spinning temperature is 270 to 300 ° C., the drawing speed is 700 to 100 ° C., and the unset yarn once wound at 1000 to 2000 m / min is heat set. The temperature is 120 to 190 ° C., the drawing speed is 200 to 1000 m / min, and the FDY method in which the draw ratio is about 0.65 to 0.85 times the maximum draw ratio of the undrawn yarn can be mentioned. The maximum draw ratio refers to the draw ratio when the undrawn yarn is cut under the conditions of a drawing temperature of 80 ° C., a heat setting temperature of 145 ° C., and a drawing speed of 600 m / min.

  In addition, as a method of spinning and drawing, for example, POY method (a method of winding as semi-undrawn yarn by high-speed spinning at 2000 m / min or more), HOY method (high-speed spinning at 5000 m / min or more) A method of winding as a yarn) or a spin draw method (a method of spinning at 200 m / min or more and continuously drawing without winding once). Moreover, you may extend | stretch after spinning by the POY method. In the spinning using the POY method, the HOY method, or the spin draw method, the spinning temperature is, for example, 270 to 300 ° C.

<Step (IV)>
The basic compound is brought into contact with the surface of the polyester fiber obtained in the step (III) to carry out an alkali reduction treatment, the produced particles present on the surface of the single fiber are detached, and micropores are formed. Further, by adding diethylene glycol, the depth of the micropores is increased, and the micropores become coarse and rough, whereby the deep-dyed polyester fiber of the present invention can be obtained. By alkali reduction treatment, fine pores preferably having a suitable size and depth can be formed at high density on the surface of a single fiber, and the resulting particles and diethylene glycol exhibit excellent deep dyeability and texture of eyelashes. The synergetic effect of The contact with the basic compound can be carried out, for example, by treatment with an aqueous solution of the basic compound. The contact with the basic compound may be carried out after subjecting the polyester fiber to a treatment such as drawing heat treatment or false twisting, if necessary, or may be carried out after the polyester fiber has been made into a fabric.

  Examples of the basic compound used in the step (IV) include sodium hydroxide, potassium hydroxide, tetramethyl ammonium hydroxide, sodium carbonate, potassium carbonate and the like. Among them, sodium hydroxide or potassium hydroxide is preferred. The concentration of the basic compound aqueous solution is, for example, in the range of 0.1 to 30% by mass, although it varies depending on the type of the basic compound or the alkali reduction treatment conditions. The treatment temperature is, for example, in the range of normal temperature to 100 ° C. The alkali loss ratio is, for example, preferably 2% by mass or more, more preferably 5% by mass or more, and still more preferably 10% by mass or more, based on the mass of the deep-dyed polyester fiber.

(Second manufacturing method)
The second production method of the present invention comprises the step of esterifying a dicarboxylic acid component and a diol component to produce a polyester oligomer (step (I '));
A phosphorus compound and an alkaline earth metal compound are added to the polyester oligomer, or a phosphorus compound and an alkali metal compound and an alkaline earth metal compound are added, and diethylene glycol is added, followed by a polycondensation reaction. A step of obtaining a polyester resin composition (step (II ′));
The polyester resin composition is disposed in the core and composite spinning is performed so as to dispose the easily soluble polyester resin in the sheath, and the shape of the core in a cross section perpendicular to the longitudinal direction of the fiber has a protrusion and a groove, Obtaining a latently dyed core-sheath composite polyester fiber having an irregular cross-sectional shape in which the number of protrusions is 10 to 32 (step (III '));
Subjecting the latent deep-dyeing core-sheath composite polyester fiber to alkali reduction treatment (step (IV ')).

<Step (I ')>
As the dicarboxylic acid, mainly terephthalic acid can be used. Other components may be copolymerized according to the purpose, as long as the effects of the present invention are not impaired. As components other than terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 5-sodium sulfoisophthalic acid, 5-tetrabutylphosphonium sulfoisophthalic acid, 4,4'-biphenyldicarboxylic acid, p-hydroxybenzoic acid, adipine Acids, sebacic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-cyclohexyldicarboxylic acid and the like can be mentioned.

  Ethylene glycol can be mainly used as the diol component. Other components may be copolymerized according to the purpose, as long as the effects of the present invention are not impaired. As components other than ethylene glycol, 1,3-propanediol, 1,4-butanediol, diethylene glycol, 1,2-propylene glycol, 2,2-dimethyl-1,3-propanediol (neopentylene glycol), Dipropylene glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dimethylol propionic acid, poly (ethylene oxide) glycol, or poly (tetramethylene oxide) glycol, etc. may be mentioned.

  In the step (I ′), a polyester oligomer is obtained by subjecting a dicarboxylic acid (a dicarboxylic acid containing terephthalic acid as a main component) and a diol (a diol containing ethylene glycol as a main component) to an esterification reaction. Here, a polyester oligomer includes a dicarboxylic acid component and a diol component, and in the case of terephthalic acid and ethylene glycol, respectively, bis (2-hydroxyethyl) terephthalate, and further, in one molecule, the repeating unit of ethylene terephthalate is 2 And a compound having an intrinsic viscosity, molecular weight and degree of polymerization which has not yet been raised to the extent that it can be called polyethylene terephthalate, and which has a carboxyl group or a hydroxyethyl group at its end. The esterification reaction can be carried out, for example, at a temperature of 250 ° C. for 3 to 8 hours until such polyester oligomers are formed. In order to detect the reaction rate of the esterification reaction, the amount of water produced can be measured.

  Examples of polyester oligomers include polymellitic carboxylic acids such as trimellitic acid, trimesic acid, trimellitic acid anhydride, pyromellitic acid, trimellitic acid monopotassium salt, glycerin, pentaerythritol, sodium dimethylol ethyl sulfonate, potassium dimethylol propionate And the like may be copolymerized within the scope of achieving the object of the present invention.

<Step (II ')>
While adding a metal compound and a phosphorus compound to said polyester oligomer, diethylene glycol is added and then a polycondensation reaction is performed, and a polyester resin composition is obtained. In the step (II ′), a reaction of the phosphorus compound and the metal compound occurs together with the polycondensation reaction, and the above-mentioned product particles which are insoluble in the polyester resin are formed.

  Regarding the addition order of the phosphorus compound and the metal compound, the phosphorus compound may precede the phosphorus compound, or the phosphorus compound may be added, or the phosphorus compound and the metal compound may be mixed and simultaneously added.

The amount of the metal compound added is preferably 10 × 10 ^{−4 to} 100 × 10 ⁻⁴ mol, more preferably 30 × 10 ⁻⁴ to 80 × 10 ⁻⁴ mol, per 1 mol of the acid component constituting the polyester. It is a mole. If the content is 10 × 10 ^-4 or more, product particles of a size sufficient for making the dyeability of the polyester fiber good can be formed, and the dyeability on the polyester fiber surface is good. The above-mentioned number of micropores necessary for the development can be developed. Since generation of coarse particles can be suppressed to 100 × 10 ⁻⁴ mol or less, clogging of the filter for filtering the melted flame retardant polyester resin composition does not occur during spinning, and the latent concentrated core can be obtained. The stability of the spinning process of the sheath composite polyester fiber can be kept good.

The amount of the phosphorus compound added is preferably 10 × 10 ^{−4 to} 100 × 10 ⁻⁴ mol, more preferably 20 × 10 ^{−4 to} 90 × 10 ⁻⁴ mol, per 1 mol of the acid component constituting the polyester. It is a mole. If the content is 10 × 10 ^-4 mol or more, produced particles of a size sufficient for making the dyeability of the polyester fiber good can be formed, and the dyeability on the surface of the polyester fiber should be good. The above-mentioned number of micropores necessary for the formation can be developed. Since generation of coarse generated particles can be suppressed to 100 × 10 ⁻⁴ mol or less, clogging of the filter for filtering the melted flame retardant polyester resin composition does not occur during spinning, and latent concentrated dyeing The stability of the spinning process of the polyester / sheath composite polyester fiber can be kept good. The molar ratio between the metal compound and the phosphorus compound is preferably (metal compound) / (phosphorus compound) = 0.5 to 1.5 in order to obtain excellent spinning stability and latent deep dyeing property.

  The addition amount of diethylene glycol is 5.5 to 9 in consideration of diethylene glycol by-produced at the time of reaction in order to set the content of diethylene glycol in the polyester resin constituting the core portion to the above-mentioned range (6 to 10 mol%). It is preferably 0.5 mol%, more preferably 7.5 to 9.5 mol%, and still more preferably 8.5 to 9.5%. It is more preferable that the addition amount of diethylene glycol is within the specified range. An alkali dissolution rate improves that it is 5.5 mol% or more, and the fiber which is excellent in deep dyeing property and eyebrows color texture can be obtained. Moreover, a fiber favorable in processability is obtained, without reducing the intensity | strength of the yarn obtained as it is 9.5 mol% or less. Either of the addition of diethylene glycol and the addition of the metal compound may precede the other.

  Then, a polycondensation catalyst (for example, an ethylene glycol solution) is added to carry out a polycondensation reaction to obtain a polyester resin composition. In the polycondensation reaction system, if necessary, an additive such as a copolymerizable monomer or an anti-coloring agent may be added as an ethylene glycol solution or a dispersion. In this case, the polycondensation reaction is started by distilling off ethylene glycol (removing ethylene glycol under reduced pressure), and the reaction is carried out while distilling off, and then the strand is removed by a conventional method to form a chip. it can. Here, the formation of product particles is started after the polycondensation catalyst is added. And as the solution is distilled off, the solubility of the product decreases and this product precipitates out as particles.

  The intrinsic viscosity (inherent viscosity) of the flame retardant polyester resin composition is preferably 0.5 to 1.5 dL / g. When the intrinsic viscosity is in this range, the physical properties of the latent concentrated core-sheath composite polyester fiber obtained by spinning the resin composition do not decrease, and further, the polyester resin composition or the latent concentrated sheath-core composite polyester fiber is Easy to manufacture.

<Step (III ′)>
A known spinning method (for example, a melt spinning method) is adopted, a preferable spinning nozzle is selected, the polyester resin composition obtained in step (II) is disposed in the core portion, and the easily soluble polyester resin is a sheath portion Composite spinning (for example, melt spinning) is performed to obtain a latent deep-dyeing core-sheath composite polyester fiber as a multifilament yarn, as described in the following. In addition, composite spinning is performed such that the core portion has a modified cross-sectional shape having 10 to 32 protrusions and grooves. The film may be wound after being wound as an undrawn yarn by a known method, or may be wound after being drawn without being wound once after discharge. Moreover, after winding up at the speed of 3000-9000 m / min, you may use for yarn processing or weaving knitting in the state as it is, without extending | stretching separately.

  Spinning conditions are not particularly limited. For example, the spinning temperature is 270 to 300 ° C., the drawing speed is 700 to 100 ° C., and the unset yarn once wound at 1000 to 2000 m / min is heat set. The temperature is 120 to 190 ° C., the drawing speed is 200 to 1000 m / min, and the FDY method in which the draw ratio is about 0.65 to 0.85 times the maximum draw ratio of the undrawn yarn can be mentioned. The maximum draw ratio refers to the draw ratio when the undrawn yarn is cut under the conditions of a drawing temperature of 80 ° C., a heat setting temperature of 145 ° C., and a drawing speed of 600 m / min.

  In addition, as a method of spinning and drawing, for example, POY method (a method of winding as semi-undrawn yarn by high-speed spinning at 2000 m / min or more), HOY method (high-speed spinning at 5000 m / min or more) A method of winding as a yarn) or a spin draw method (a method of spinning at 200 m / min or more and continuously drawing without winding once).

<Step (IV ')>
The basic compound is brought into contact with the surface of the latently dyed core-sheath type polyester fiber obtained in step (III ') to carry out an alkali reduction treatment to elute the soluble polyester resin and to form on the surface of the single fiber The particles fall off to form fine pores. Thereby, the deep dyeable polyester fiber of the present invention is obtained. The alkali reduction treatment makes it possible to form a fiber having a cross-sectional shape having protrusions and grooves, and to form micropores having an appropriate size and depth on the surface of a single fiber at a high density. Due to the fine pores and the atypical cross-sectional shape, a synergetic effect of exhibiting excellent deep staining is exhibited. The contact with the basic compound can be carried out, for example, by treatment with an aqueous solution of the basic compound. The contact with the basic compound may be carried out after subjecting the polyester fiber to a treatment such as drawing heat treatment or false twisting, if necessary, or may be carried out after the polyester fiber has been made into a fabric.

  Examples of the basic compound used in the step (IV ′) include sodium hydroxide, potassium hydroxide, tetramethyl ammonium hydroxide, sodium carbonate, potassium carbonate and the like. Among them, sodium hydroxide or potassium hydroxide is preferred. The concentration of the basic compound aqueous solution is, for example, in the range of 0.1 to 30% by mass, although it varies depending on the type of the basic compound or the alkali reduction treatment conditions. The treatment temperature is, for example, in the range of normal temperature to 100 ° C. The alkali loss ratio is, for example, preferably 2% by mass or more, more preferably 5% by mass or more, and still more preferably 10% by mass or more based on the mass of the latent deep dyed core-sheath composite polyester fiber.

  The deep-dyed polyester fiber of the present invention may be combined with other fibers, for example, into a spun yarn or a mixed yarn. In addition, the form of the deep-dyed polyester fiber of the present invention may be a long fiber or a short fiber, and if necessary, it may be subjected to post-processing such as crimping, false twisting, or treatment with a chemical solution. It may be done.

  The deep-dyed polyester fiber of the present invention is excellent in deep-dyeing properties and also excellent in eyebrow-like texture, and has a high-class feeling. The woven or knitted fabric of the present invention containing such a deep-dyed polyester fiber is suitably used for textiles requiring deep-dyeing properties such as clothing (especially black formal), swimwear, sports innerwear, lingerie or foundation. .

  Hereinafter, the present invention will be specifically described according to examples. The invention is not limited to this example.

The measurement method or evaluation method in the embodiment of the present invention is as follows.
(1) Intrinsic viscosity It measured based on the conventional method on conditions of the temperature of 20 degreeC, using the equal mass mixture of phenol and ethane tetrachloride as a solvent. A Ubbelode viscometer (manufactured by Asahi Kasei Technosystem, "AVS-6") was used as a viscometer.

(2) Average particle size of the generated particles (median diameter)
A solution in which a dark dyeable polyester fiber or a dark dyeable polyester / sheath type polyester fiber is subjected to alkali reduction treatment and eluted with an easily soluble polyester resin to dissolve the dark dyeable polyester fiber in hexafluoroisopropanol On the other hand, measurement was carried out using a laser diffraction / scattering particle size analyzer (manufactured by Shimadzu Corporation, "SALD-7100").

(3) L value Latent deep dyeing polyester fiber or latent deep dyeing core-sheath composite polyester fiber with a knitting machine (Koike Machinery Co., Ltd., number of needles: 300, hook diameter: 3.5 inches) The fabric was knitted on the ground and subjected to alkali reduction treatment and dyeing under the conditions described later to obtain a tubular knitted fabric containing deep dyeing polyester fiber. The L value of the tubular knitted fabric was measured using a color difference meter (Macbeth spectrophotometer CE-3100). The L value indicates that the smaller the value is, the deeper the color is.
(Alkali weight loss treatment)
Using an aqueous sodium hydroxide solution (2% by mass), alkali reduction treatment was performed under the conditions of a temperature of 98 ° C., a time of 30 minutes, and a bath ratio of 1:50 (a weight loss rate of 30%). In the case of latent deep-dye core-in-sheath composite polyester fiber, the step of completely eluting the easily soluble polyester resin in the sheath is regarded as a weight loss rate of 0%, and then alkali weight loss treatment until the weight loss rate reaches 30%. went.
(staining)
A dye agent (Dystar, trade name "Dianix Black HG-FS conc., Disperse dye") was used at a ratio of 7.5% omf. The dyeing was performed at a temperature of 135 ° C. for 30 minutes at a bath ratio of 1:50. Then, reduction washing was performed at 80 ° C. for 20 minutes with an aqueous solution containing sodium hydroxide (0.2 mass%) and hydrosulfite (0.2 mass%).

(4) Number of Micropores Ten single fibers of deep dyeable polyester fiber were randomly collected from the dyed tubular fabric. The surface of this single fiber was photographed at a magnification of 5000 using a scanning electron microscope (SEM). An inspection area of 5 μm in height × 5 μm in width was randomly set in the photographed photograph, and the number of micropores present in this area was counted to obtain an average value of 10 holes.

(5) Size of micropores In the photograph taken in the above (4), 30 micropores present on the fiber surface were randomly selected. The length in the longitudinal direction of the fiber was taken as the major axis, the length in the direction orthogonal to the longitudinal direction was taken as the minor axis, and the average value of each was determined.

(6) Depth of Micropores A single filament of a thick dyeable polyester fiber was collected from the dyed tubular knitted fabric and cut perpendicularly to the fiber axial direction (longitudinal direction). This cut surface was photographed at a magnification of 10000 using a scanning electron microscope (SEM). In this photograph, 30 micropores present on the fiber surface were randomly selected, the depth of the micropores was measured, and the average value was determined. In addition, the depth of the micropores was measured at the place where the distance from the single fiber surface is the largest.

(7) Number and size (width and height) of protrusions
One single fiber of a deep-dyed polyester fiber was collected from the dyed tubular fabric and cut perpendicularly to the fiber axial direction (longitudinal direction). The cut surface was photographed and counted at a magnification of 10000 using a scanning electron microscope (SEM).

(8) Spinnability Evaluation was made according to the following criteria according to the number of yarn breakage at the time of spinning when operating continuously for 24 hours.
○: The number of thread breaks 0 to 1 1: The number of thread breaks 2 to 4 ×: The number of thread breaks 5 or more

(9) Dissolution rate When a latent deep dyeing polyester fiber or latent deep dyeing core-sheath composite polyester fiber is treated with an alkaline solution to form a thick dyeing polyester fiber, the amount of weight change (g) before and after alkali treatment, The alkali dissolution rate per unit surface area (g / (min · m ² )) was calculated and evaluated by the following equation using the processing time (min) and the measurement value of the single yarn fineness (dtex).
Alkali dissolution rate (g / (min · m ² )) = ((fiber weight before alkali treatment−fiber weight after alkali treatment) / (alkali treatment time × surface area of single yarn))
In addition, the surface area S of single yarn was calculated | required from the following calculation formulas.
m: Fiber weight at the time of measurement [g]
π: pi n: number of filaments (n = 24)
x: fineness [dtex]
ρ: density of polyester (ρ = 1.35 × 10 ⁶ ) [g / m ³ ]
In the case of latent deep-dye core-sheath composite polyester fiber, the state in which the easily soluble polyester resin in the sheath is completely eluted is defined as before alkali treatment (weight reduction rate 0%) and subjected to further alkali treatment The (weight loss rate of 30%) was defined as before and after alkali treatment.

(10) Eyebrow-like texture (wool-like texture)
The latent deep-dyed polyester fiber or latent deep-dye core-sheath composite polyester fiber is knitted into a tubular knit fabric using a knitting machine (made by Koike Kikai Seisakusho, number of needles: 300, hook diameter: 3.5 inches), An alkali reduction treatment and dyeing were applied under the above conditions to obtain a tubular knitted fabric containing deep dyeing polyester fibers, and the feel of the tubular knitted fabric was evaluated based on the following criteria.
○: good △: somewhat good ×: poor

Production of Polyester Resin Composition (Polyester Resin Composition Having Solubility in Alkali) <Polyester Resin Composition A>
A slurry of terephthalic acid (TPA) and ethylene glycol (EG) (having a molar ratio of TPA: EG = 1.6) is continuously supplied to an esterification reactor in which a polyester low polymer is present, and the temperature is 250 ° C. and the pressure is The reaction was carried out under the condition of 50 hPa to continuously obtain a polyester low polymer having an esterification conversion rate of 95%. The polyester low polymer was charged into a polycondensation reaction vessel, and the inside of the vessel was replaced with nitrogen. Subsequently, 7.5 mol% of diethylene glycol was added in consideration of the by-product. 3.0 × 10 ^-4 mol of antimony trioxide as a polycondensation catalyst with respect to acid component 1 mol of constituting the polyester, 40 × triethyl phosphate as a phosphorus compound relative to the acid component 1 mol of constituting the polyester 10 ^{- 4} mol, 35 × ^{10 -4} mol of magnesium acetate relative to the acid component 1 mol of constituting the polyester, and, and the lithium acetate was added 35 × ^{10 -4} mol of the acid component 1 mol of constituting the polyester. The pressure was gradually reduced to 1.2 hPa or less after 1 hour. The polycondensation reaction was carried out for 3 hours under the temperature condition of 280 ° C. while stirring under these conditions, and then was dispensed by a conventional method to form a pellet, thereby obtaining a polyester resin composition A having an intrinsic viscosity of 0.69 dL / g.

<Polyester resin composition B to C>
The procedure of polyester resin composition A was repeated, except that the amount of diethylene glycol added was changed to the value shown in Table 1 with respect to 1 mole of the acid component constituting the polyester. The limiting viscosity of each of the polyester resin composition B and the polyester resin composition C was 0.69 dL / g and 0.69 dL / g, respectively.

<Polyester resin composition D>
It is carried out in the same manner as polyester resin composition A, except that only magnesium acetate is used as the metal compound, and the addition of the phosphorus compound is changed to the value shown in Table 1 with respect to 1 mol of the acid component constituting the polyester. Thus, a polyester resin composition D having an intrinsic viscosity of 0.69 dL / g was obtained.

<Polyester resin composition E>
It implemented similarly to polyester resin composition A except not having added diethylene glycol, and obtained polyester resin composition E whose intrinsic viscosity is 0.69 dL / g.

<Polyester resin composition F>
It implemented similarly to polyester resin composition D except not having added diethylene glycol, and obtained polyester resin composition F whose intrinsic viscosity is 0.69 dL / g.

<Polyester resin composition G>
It is carried out in the same manner as polyester resin composition A, except that only lithium acetate is used as the metal compound, and the addition of the phosphorus compound is changed to the value shown in Table 1 with respect to 1 mol of the acid component constituting the polyester. Thus, a polyester resin composition G having an intrinsic viscosity of 0.69 dL / g was obtained.

<Polyester resin composition H>
It implemented similarly to polyester resin composition A except not having added a phosphorus compound and a metallic compound, and obtained polyester resin composition H whose intrinsic viscosity is 0.69 dL / g.

Example 1
The polyester resin composition A was charged into a conventional melt spinning machine and spun from a spinneret having 24 spinning holes. The spun yarn was cooled by an air stream and passed through an oiling device (oil agent feeding device) to apply an oil agent. The yarn was pulled at a spinning speed of 3250 m / min (90 dtex 24 f). The spinning temperature was 280.degree. The obtained yarn is stretched 1.7 times through a heat roller at 80 ° C. with a conventional stretching machine, and further heat treated with a heat plate at 160 ° C. to be wound, and polyester fiber (stretched yarn ( Latent deep dyeing polyester fiber was obtained (56 dtex 24 f).

This latent deep-dyeing polyester fiber is knitted into a tubular fabric by the above-mentioned machine, and using an aqueous solution of sodium hydroxide (2% by mass), the alkali weight is reduced under the conditions of a temperature of 98 ° C., a time of 30 minutes and a bath ratio of 1:50. Treated (weight loss rate 30%). As a result, the deep-dyed polyester fiber of the present invention was obtained, in which the produced particles fell off and coarse pores were formed with a specific size and a specific number.
Next, staining was performed in the following manner. A dye agent (Dystar, trade name "Dianix Black HG-FS conc., Disperse dye") was used at a ratio of 7.5% omf. The dyeing was performed at a temperature of 135 ° C. for 30 minutes at a bath ratio of 1:50. Subsequently, reduction washing was carried out at 80 ° C. for 20 minutes with an aqueous solution containing sodium hydroxide (0.2 mass%) and hydrosulfite (0.2 mass%), and the tubular knitted fabric was subjected to various evaluations.

(Examples 2 to 4)
Example 6 was carried out in the same manner as Example 1, except that polyester resin compositions B to D were used instead of polyester resin composition A.

(Example 5)
The same procedure was performed as in Example 1 except that the nozzles used were changed, and the number of protrusions, the number of fine grooves, and the size of protrusions were changed to the values shown in Table 1. More specifically, a polyester resin (2.0% by mass of sodium sulfonate and 6.0% by mass of polyethylene glycol copolymerized with alkali) was further copolymerized so that polyester resin composition A was disposed in the core. The copolyester is placed in the sheath, and it is introduced into a melt spinning machine for conventional composite spinning, and from the core having 20 protrusions and grooves and the sheath disposed around it The modified cross section fiber is spun out of a spinneret with 24 spinnerets that can be spun. The spun yarn was cooled by an air stream and passed through an oiling device (oil agent feeding device) to apply an oil agent. The yarn was withdrawn at a spinning speed of 3250 m / min (84 dtex 24 f). The obtained yarn is drawn 1.5 times through a heat roller at 85 ° C. with a common drawing machine, and further heat treated with a heat plate at 170 ° C. and wound up to form polyester fiber (drawn yarn ( A latent deep dyeing core-sheath composite polyester fiber) was obtained (56 dtex 24 f). In this polyester fiber, the composite ratio (mass ratio) of the core and the sheath was core: sheath = 81: 19.

  The latent deep-dyeing core-sheath composite polyester fiber was knitted into a tubular knit fabric, subjected to alkali reduction treatment, dyeing and reduction washing under the above conditions, and the tubular knit fabric was subjected to various evaluations.

(Examples 6 to 9)
The procedure of Example 5 was repeated, except that the nozzles used were changed, and the number of protrusions, the number of fine grooves, and the size of the protrusions were changed to the values shown in Table 1.

(Comparative Examples 1 to 3)
The procedure of Example 1 was repeated except that polyester resin compositions E to G were used instead of polyester resin composition A. Comparative Examples 1 and 2. In Comparative Examples 4 and 6 described later, the spinning temperature was 295 ° C.

(Comparative example 4)
A polyester resin composition A was replaced with a resin composition containing polyethylene terephthalate having an intrinsic viscosity of 0.65 dL / g and containing silica fine particles (average particle diameter: 0.60 μm) in a proportion of 1.5% by mass. The same procedure as in Example 1 was performed.

(Comparative example 5)
Example 6 was carried out in the same manner as Example 1, except that polyester resin composition H was used in place of polyester resin composition A.

(Comparative example 6)
The procedure was carried out in the same manner as in Example 1 except that polyethylene terephthalate having an intrinsic viscosity of 0.65 dL / g was used instead of the polyester resin composition A and charged into a conventional melt spinning machine.

(Comparative example 7)
The procedure of Example 5 was repeated, except that the nozzle used was changed and a polyester resin composition A was replaced with polyethylene terephthalate having an intrinsic viscosity of 0.65 dL / g and put into a conventional melt spinning machine.

  Tables 1 and 2 collectively show the evaluations of Examples 1 to 9 and Comparative Examples 1 to 7.

  As is clear from Table 1, in Examples 1 to 3, although the formed particles having a particle diameter of comparable degree were formed as compared with Comparative Example 1 in which diethylene glycol was not used, a specific amount of diethylene glycol was contained. Because the dissolution rate by alkali reduction treatment is fast, and the micropores on the surface of the fiber are deep and rough, the L value is lower and the deep dyeability is excellent, and the eyebrow color texture is excellent. became. Furthermore, the average particle size of the produced particles formed was in an appropriate range, and the size, number, and particularly depth of the micropores satisfied the range defined in the present invention. Therefore, the L value was sufficiently low, and a polyester fiber excellent in deep dyeability could be obtained.

  2 is a photograph of the surface of the single-dye surface of the deep-dyed polyester fiber of the present invention obtained in Example 3, and FIG. 3 is a photograph of the single-fiber surface of the polyester fiber obtained in Comparative Example 1. It is a photograph (magnification; 5000 times). As can be understood from FIGS. 2 and 3, the deep dyeing polyester fiber according to the present invention of Example 3 has deeper micropores formed on the fiber surface by the addition of diethylene glycol, as compared with Comparative Example 1. It is clear that it is rough.

  In Example 4, by using only magnesium acetate as the metal compound, the average particle diameter of the formed particles was small, but in comparison with Comparative Example 2 in which diethylene glycol was not used, the addition of diethylene glycol resulted in an alkali The dissolution rate by weight loss treatment became faster, and the fine pores on the fiber surface became larger and rougher, and as in Examples 1 to 3, the L value is lower and the dark dyeability is excellent, and the eyebrow-like texture It was also excellent.

  In Examples 5 to 7, by changing the number of projections in the cross section, multiple scattering of incident light is promoted more than in the case of the round cross section compared to Example 1, and thus polyester fibers excellent in deep dyeability are obtained. I was able to. Further, in Example 5, the number of protrusions is larger compared to Example 6, and the multiple scattering of incident light is further promoted, and the width and height of the protrusions are sufficiently long as compared to Example 7. Therefore, multiple scattering of incident light was further promoted, and the deep dyeability was superior. Furthermore, in Example 5, the multiple scattering of incident light is further promoted because the number of protrusions in the cross section, the width of the protrusions, and the height are more preferable ranges as compared with Examples 8 and 9, and deep staining is possible. The polyester fiber which is remarkably excellent in

  In Comparative Example 3, since only lithium acetate was used as the metal compound, the average particle size of the formed particles formed was too large, and the size and number of the micropores were out of the range defined in the present invention. As a result, only polyester fibers having higher L values and inferior deep dyeing properties were obtained. In addition, the filter pressure of the nozzle pack increased rapidly, resulting in poor spinning operability. Furthermore, the eyebrow-like texture was also inferior.

  In Comparative Example 4, regardless of the primary particle diameter of the silica fine particles, the aggregation of the silica fine particles made the micropores too large and the number of micropores was too small, so only polyester fibers inferior to deep dyeing properties were obtained. In addition, cut yarns that are believed to be caused by coarse particles due to aggregation are generated, resulting in poor spinning operability. Furthermore, it was inferior to the eyebrow-like texture.

  In Comparative Example 5, the metal compound and the phosphorus compound are not added, and only the diethylene glycol is contained, and no micropores are formed on the fiber surface, so that the L value is large and only the polyester fiber which is inferior to the deep dyeing property It was not obtained. Furthermore, it was inferior to the eyebrow-like texture.

  In Comparative Example 6, the metal compound, the phosphorus compound and the diethylene glycol were not added, whereby no micropores were formed on the fiber surface, and only the polyester fiber inferior to the deep dyeing property was obtained. Furthermore, it was inferior to the eyebrow-like texture.

  In Comparative Example 7, due to the protrusion of the cross section, the deep dyeing property was superior to that of the round cross sectional shape compared to Comparative Example 6, but no metal compound, phosphorus compound and diethylene glycol were added, thereby Only micropores were not formed on the fiber surface, and only polyester fibers inferior to deep dyeing properties were obtained. Furthermore, it was inferior to the eyebrow-like texture.

1 Latent deep-dyeing core-sheath composite polyester fiber of the present invention 2 Easily soluble polyester resin (sheath)
3 Polyester resin (core)
A Dense polyester fiber B Protrusions C Grooves 4 and 5 Intersection 4 'of line on side of protrusion and circumscribed circle of apex of protrusion 5', line on side of 5 'protrusion and inscribed circle of deepest part of narrow groove Point of intersection 6 middle point 6 'of line segment 4-5 end point of line segment 4'-5'

Claims (12)

A latently dyeable polyester fiber comprising a polyester resin composition containing a polyester resin and product particles,
The polyester resin contains 6.0 to 10.0 mol% of a diethylene glycol component,
The produced particles are characterized in that they are derived from a phosphorus compound and an alkaline earth metal compound, or are derived from a phosphorus compound, an alkali metal compound and an alkaline earth metal compound. Dark dyed polyester fiber.   The latent concentrated polyester fiber according to claim 1, wherein an average particle size of the produced particles is 0.05 to 0.5 m. The alkaline dissolution rate per unit surface area in an aqueous solution having a temperature of 98 ° C. and a concentration of a basic compound of 2% by mass is 10.0 g / (min · m ² ) or more. The latent deep dyeing polyester fiber according to 2. A latently dyed core-sheath composite polyester fiber in which a polyester resin composition is disposed in the core and a highly soluble polyester resin is disposed in the sheath,
The polyester resin composition comprises a polyester resin and product particles,
The polyester resin contains 6.0 to 10.0 mol% of a diethylene glycol component,
The produced particles are derived from a phosphorus compound and an alkaline earth metal compound, or are derived from a phosphorus compound, an alkali metal compound and an alkaline earth metal compound,
The shape of the core in the cross section perpendicular to the fiber axis direction of the single fiber is a modified cross-sectional shape having a protrusion and a groove, and the cross-sectional shape of the protrusion and the groove is rectangular or substantially trapezoidal. The latent dense core / sheath composite polyester fiber, wherein the number of parts is 10 to 32.   The latently dyed core-sheath composite polyester fiber according to claim 4, wherein an average particle diameter of the produced particles is 0.05 to 0.5 m. The core part is characterized in that an alkaline dissolution rate per unit surface area in an aqueous solution having a temperature of 98 ° C. and a concentration of a basic compound of 2% by mass is 10.0 g / (min · m ² ) or more. The latent deep-dyeing core-sheath composite polyester fiber according to claim 4 or 5. A deep-dyed polyester fiber having micropores on the surface of a single fiber and made of a polyester resin, wherein the polyester resin contains 6.0 to 10.0 mol% of a diethylene glycol component,
The number of the micropores is 15 or more in a 5 μm × 5 μm size area on the surface of the single fiber, the major axis length is 0.9 μm or less, and the minor axis length is 0.6 μm or less And deep polyester fiber having a depth of 250 to 800 nm. The single fiber is a modified cross-section fiber in which protrusions and narrow grooves are alternately and almost uniformly distributed on the surface,
The cross-sectional shape of the projection and the narrow groove is rectangular or substantially trapezoidal, and the projection and the narrow groove are each continuous in the fiber axis direction,
The deep dyeable polyester fiber according to claim 7, wherein the number or size of the protrusions satisfies the following (I) to (III).
10 <N <32 (I)
0.3 ≦ W ≦ 2.0 (II)
0.5 W ≦ H ≦ 3.0 W (III)
However, N is the number of protrusions, W is the width (μm) of the protrusions, and H is the height (μm) of the protrusions.   The deep dyeable polyester fiber according to claim 7 or 8, characterized in that the L value is 13.0 or less when subjected to a black dyeing process as a tubular knitted fabric. A method for producing the deep-dyed polyester fiber according to claim 7 or 9,
Esterifying a dicarboxylic acid component and a diol component to form a polyester oligomer;
A phosphorus compound and an alkaline earth metal compound are added to the polyester oligomer, or a phosphorus compound and an alkali metal compound and an alkaline earth metal compound are added, and diethylene glycol is added, followed by a polycondensation reaction. Obtaining a polyester resin composition;
Spinning the polyester resin composition to obtain latent deep dyeing polyester fibers;
And d) subjecting the latent deep dyeing polyester fiber to alkali reduction treatment. A method for producing the deep-dyed polyester fiber according to claim 8 or 9,
Esterifying a dicarboxylic acid component and a diol component to form a polyester oligomer;
A phosphorus compound and an alkaline earth metal compound are added to the polyester oligomer, or a phosphorus compound and an alkali metal compound and an alkaline earth metal compound are added, and diethylene glycol is added, followed by a polycondensation reaction. Obtaining a polyester resin composition;
The polyester resin composition is disposed in the core and composite spinning is performed so as to dispose the easily soluble polyester resin in the sheath, and the shape of the core in a cross section perpendicular to the longitudinal direction of the fiber has a protrusion and a groove, Obtaining a latently dyed core-sheath composite polyester fiber having an irregular cross-sectional shape in which the number of protrusions is 10 to 32;
And d. Subjecting the latent deep dyeing core-sheath composite polyester fiber to alkali reduction treatment. A woven or knitted fabric comprising the deep dyeing polyester according to any one of claims 7 to 9.