JPS6338468B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a polyester synthetic fiber in which the fiber surface forms a random surface with irregular irregularities and further has ultrafine irregularities within the irregularities forming the random surface. Traditionally, various organic synthetic fibers, especially melt-spun synthetic fibers, have a unique waxy feel due to the smoothness of the fiber surface, and have a texture that affects friction, such as the dry feel and squeaking of silk, silk ringing, etc. The characteristics related to slippery texture, such as the smooth texture of cotton, were inferior to those of natural fibers. In addition, synthetic fibers produced by melt-spinning have a unique specular luster, and even when dyed, they have the disadvantage that it is difficult to obtain the depth of color compared to natural fibers such as wool and silk. Various methods have been disclosed for the purpose of solving these drawbacks. For example, in Japanese Patent Publication No. 45-39055, silica with a particle size of 10 to 150 microns is contained in an amount of 0.05 to 30% based on the weight of the polymer to form protrusions on the fiber surface and improve the friction characteristics of the fiber surface. Disclosed. Also, special public service in 1977-
In No. 26887, an amorphous undrawn fiber is brought into contact with a crystallizing agent, and by removing the crystallizing agent, an amorphous core and a crystallized sheath are formed, and by drawing this, unevenness is created on the fiber surface. A method for obtaining the is disclosed. However, although the friction properties of fibers obtained by these methods can be improved to some extent, it cannot be compared with the texture of natural fibers, and the fiber surface has large irregularities and is coarse in density. As a result, it lacked gloss and transparency, and when dyed, it lacked sharpness compared to normal smooth fibers, resulting in pastel-like colors and no deep colors. On the other hand, various attempts have been made to improve the surface morphology and properties of fibers by removing heterogeneous mixtures present inside the fibers. An example of this is a method of extracting a part of two-component fibers made from polymer blends or composite spinning, but this method leaves a void inside after extraction, devitrification, and lack of luster, and the color does not change even after dyeing. At present, the depth of color cannot be obtained, and the variation in unevenness is too coarse in composite spinning, making it impossible to obtain the expected good gloss and depth of color. Other examples include Tokko Sho 43-14186, Tokko Sho No.
As in No. 43-16665, fine particulate inert substances are contained in the fibers, and the fine particulate inert substances are removed by treatment with an acid or alkali that does not damage the fibers and dissolves the fine particulate inert substances. A method of making the surface rough is also known. However, although this method has a matting effect, the stretching creates cavities, and the removal of particles also increases the cavities, resulting in fibers that lack transparency, and when dyed, they become whitish, or in other words, pastel colors. I end up. Furthermore, it is known that knitted fabrics made of polyester synthetic fibers are treated with alkali to hydrolyze the fiber surface and impart flexibility to the knitted fabrics. Even when knitted fabrics are treated with alkali, no noticeable effect other than softening can be imparted compared to untreated fibers or knitted fabrics. As mentioned above, in the known methods of treating fibers with solvents, it is difficult to obtain a characteristic effect when it comes to imparting a fine uneven shape, and it is difficult to understand how much unevenness should be used to achieve quality merits as a textile product. The results are unclear, and none of them can give satisfactory results in terms of gloss, vividness of dyed products, and depth of color.
Also, the texture could not be satisfactory. On the other hand, a method of irradiating organic synthetic fibers with plasma in a glow discharge plasma to give the fiber surface an unevenness of 0.1 to 0.5μ to improve color development (Japanese Unexamined Patent Publication No. 1983-1999-1)
No. 99400) was found. When organic synthetic fibers are subjected to low-temperature plasma treatment, fine irregularities are formed on their surfaces, and most of these irregularities are formed in the form of ridges orthogonal to the fiber axis. This is thought to be significantly involved in the orientation during the fiber formation stage, and is a phenomenon observed when plasma etching is performed on the surface of a fiber with uniaxial molecular orientation that has been given a degree of stretching that normally provides fiber performance. . This ridge-like unevenness is different from the direction of the unevenness formed on the surface of the fiber of the present invention, which will be described later, in that it is perpendicular to the fiber axis, and the size and shape of the ridge-like unevenness are different from the surface of the fiber of the present invention. There is no randomness seen in the size and shape of the unevenness formed in , but there is strong regulation and uniformity. Therefore, in the case of such ridge-like unevenness perpendicular to the fiber axis, there is a coloring effect when viewed from an angle perpendicular to the ridges, but it is inferior when viewed from an angle parallel to the ridges. For this reason, when looking at the fibrous aggregate as a whole, for example, as a cloth, the improvement in color development is not as great as expected, and even if a large effect is attempted, long irradiation is required, making it less practical in terms of cost. There was a problem. In addition, the plasma irradiated surface has limited ridge-like irregularities, so the gloss modification effect is small, and not only is the color development inferior, but a problem unique to plasma etching is that the irradiated surface becomes uneven, but the inside between the fibers is uneven. There was a problem in that the improvement effect in terms of texture was still insufficient. In this way, fibers with excellent color development that eliminate the waxiness and specular luster characteristic of synthetic fibers, and their manufacturing methods, have been studied in terms of their effectiveness, quality, industrial productivity, technical stability, and economic constraints. However, all of them lacked feasibility for industrialization. In view of such quality problems, the present invention has been developed by examining technology for making the surface of polyester-based synthetic fibers uneven, and has conducted intensive research on the quality merits and the problem of uneven shapes for that purpose, and can be used as an industrially stable production technology. This is a search to find a method. That is, an object of the present invention is to provide a polyester synthetic fiber that has both improved optical properties and tactility. Another purpose is to have a fine and complex uneven shape on the fiber surface, which allows the dyed product to have excellent color development and deep color, and also to have an excellent texture similar to silk. It is an object of the present invention to provide a polyester-based synthetic fiber having the following properties. Another object of the present invention is to provide a method for industrially stably producing polyester synthetic fibers having fine and complicated surface irregularities. Further objects will become apparent from the following description and examples. In order to achieve the above objects, the present invention relates to a method for producing polyester synthetic fibers having the following structure as an uneven structure on the surface of the fibers. That is, the present invention provides the following methods: a. A sol of inert fine particles with an average particle size of 100 microns or less is added to the glycol component in advance to dilute it, or/and is added to the slurry of the acid component and the glycol component. b. The diluted sol is added to the system before the start of the esterification reaction or transesterification reaction so that the content of inert fine particles is 0.5 to 10% by weight based on the produced polymer. or after the start of the reaction, (i) into the esterification reaction system at temperatures below 295°C in the case of a continuous method or below 265°C in the case of a batch method; (ii) into the transesterification system. In the case of continuous method, the temperature is 235℃ or less, and in the case of batch method, it is 200℃ or less. Polymerizing the esterified product or transesterified product to obtain a polyester polymer having a number average degree of polymerization of 70 or more; d melt-spinning the polyester polymer by a conventional method to obtain a 0.1 to 0.5 micron particle consisting of the inert fine particles; Producing a fine particle-containing polyester fiber, in which at least 5 secondary particles as defined below are present per 10 square microns, and no more than 20 secondary particles with a particle size exceeding 5 microns are present in 1 cubic millimeter of fiber, e) A method for producing polyester synthetic fibers in which the surface of the obtained fibers is eluted and eroded using a solvent that is soluble or decomposable for the fibers. However, secondary particles are defined as particles whose single particle size has been enlarged to the extent that they can be identified. A group of particles in which the distance between the centers of adjacent single particles is less than twice the diameter of a single particle when seen in an electron micrograph is defined as a secondary particle. ” regarding. Here, in order to clarify the definition of the uneven state of the fiber surface in the present invention, it will be explained using drawings. The first example is a general example of the surface curve of a fiber cross section.
As shown in Fig. and Fig. 2. In general, surfaces can be roughly divided into surfaces with regular irregularities (FIG. 1) and irregular surfaces (FIG. 2), which are called regular surfaces and random surfaces. A regular surface is a surface cut with a knife with a regularly shaped tip, such as a turned surface, and a random surface is a surface that has been ground or polished with irregularly shaped abrasive grains, such as a lap surface, or a surface that is cast. , and the random surface referred to in the present invention refers to this. Note that the term "random surface" as used in the present invention typically refers to a surface in which convex portions with irregular peak heights and concave portions with irregular valley depths coexist; A surface where the depth of the concave valleys is almost the same and the depth of the concave valleys is irregular, or conversely, a surface where the depth of the concave valleys is almost the same but the height of the convex peaks is irregular are also included as random surfaces. It means something. According to the present invention, in order to eliminate the waxy specular gloss characteristic of melt-spun polyester synthetic fibers and increase the depth of color, the fiber surface has irregular irregularities to form a random surface. It is important that the irregularities forming the random surface further include fine irregularities of 50 to 200 millimicrons. FIG. 3 schematically illustrates a cross-sectional view showing such an uneven state, and shows that fine unevenness exists within the unevenness forming a relatively large random surface. More preferably, the unevenness forming a random surface is defined as the distance on a plane between the lowest point of a concave portion and the lowest point of an adjacent concave portion existing in the outer circumferential direction perpendicular to the fiber axis on the fiber surface. Satisfying the range of 0.2 microns <
It exists at a density of 50. The depth and height of the unevenness can range from 0.05 microns to about 1/3 of the fiber diameter depending on damage to the fiber surface, but the positional relationship between the depressions and protrusions can be expressed by the distance on a plane. When expressed as X according to the above definition, X is 0.2
When there were only microns or less, there was little decrease in specular reflectance, the depth of the color after dyeing was not much different from conventional ones, and the effect of improving frictional behavior was insufficient. If X is larger than 0.7 microns, the reflectance of visible light will be high, and the color will tend to become dull and whitish, making it even less effective. Even if it has irregularities in a range where In this case, the effect of improving color development and the depth of color of polyester fibers is insufficient. In addition, as a result of intensive study of the frictional behavior of fibers, the present inventors have found that simply increasing the friction coefficient of the entire fiber eliminates the waxy feel of polyester synthetic fibers, and improves the feel of silk and the smoothness of cotton. He admitted that he couldn't feel it. In other words, if the fibers are used in a woven or knitted structure that simply has a higher coefficient of friction, it will not only give a rough feel to the touch, but will also increase the hysteresis during the recovery process of the fabric after bending or shearing deformation. This resulted in a loss of drapability and suppleness. In order to change the surface feel of the fabric and not to cause large hysteresis in the deformation recovery characteristics of the fabric, it was important to increase the static friction coefficient and not increase the dynamic friction coefficient too much. In other words, it has been found that when μs/μd is 1.7 or more, preferably 1.9 or more, where μs is the coefficient of static friction and μd is the coefficient of dynamic friction, the sliding texture is improved and the material has an unprecedented feel. The friction coefficient defined here is a measurement of the friction between fibers using the radar method.For short fibers, a small amount of tufts made by combing staples is pasted on the outer circumference of the drum, and the Measure the frictional force with short fibers that are in half-circle contact. For long fibers, strainer filament yarns without bulking are used at 150T/M to 250T/M.
After twisting, 48 fibers were arranged on the outer periphery under a tension of 0.1 g/d on a drum with approximately the same diameter as the short fibers.
Similar to short fibers, the filament yarn is brought into contact with the drum for half a circumference and the frictional force is measured. The static friction coefficient μs is calculated from the initial frictional force when the drum starts rotating, and the dynamic friction coefficient μd is the value calculated from the frictional force when the drum is rotating at a surface speed of 90 cm/min. Even if the fiber has such frictional behavior, it must not exhibit poor pastel color development after dyeing. After researching this problem and the surface structure that controls μs and μd, we found that they are affected by the fine structure of the fiber surface. i.e. 0.2 on the fiber surface
It was found that the desired behavior was obtained in the presence of random surface irregularities of ~0.7 microns. If large random surface irregularities exceeding 0.7 microns become the main feature, the roughness will increase and the texture will not be good. On the other hand, when the unevenness is less than 0.2 microns, the effect of increasing the static friction coefficient μs is not so noticeable. FIG. 4, FIG. 5, and FIG. 6 show scanning electron micrographs showing the surface condition of polyester fibers as an example of the present invention. Figure 4 shows 3000 times the
Moreover, the magnification of FIGS. 5 and 6 is 24,000 times.
For comparison, FIG. 7 shows the surface condition of ordinary polyester fibers subjected to ordinary alkali treatment using a scanning electron microscope. Figure 7 is at a magnification of 6000x. As shown in FIG. 7, even if ordinary polyester fibers are simply treated with alkali, only large holes are formed on the fiber surface, and the number of holes is also small. Therefore, although the objective of softening as described above can be achieved, it is not possible to obtain a dyed product with a deep color, and the effect of increasing the coefficient of static friction is not significant. On the other hand, the fibers obtained by the method of the present invention have a surface structure with fine irregularities of 50 to 200 millimicrons, as seen in FIGS. 4, 5, and 6. Typically, a wall consisting of a fine granular structure, as observed in Figure 5, forms fine, multilayered unevenness, and the surface on which the fine and multilayered unevenness is formed. Even though the fibers have the aforementioned density, they form a random surface with irregular irregularities, and are unique in that the surface condition is significantly different from the conventional alkali-treated fibers as seen in Figure 7 above. It is true.
In the fiber of the present invention, the fine irregularities of 50 to 200 millimeters provide a canceling effect due to the phase difference between the reflected lights at the fine irregularities when the incident light incident on the fiber surface is reflected. Furthermore, due to the unevenness that forms an irregular random surface, light incident on the uneven surface is repeatedly scattered and re-scattered around the uneven surface, which reduces the reflected light. It seems that it has. Therefore, due to the above-mentioned specific surface structure, the fibers obtained by the present invention have excellent optical properties that cannot be obtained with conventional alkali-treated polyester fibers or conventional modified polyester fibers. This provides an excellent silky feel and silky texture. This unique structure is created by skillfully using fine particles that are more highly atomized than the fine particulate inert substances conventionally used for fiber modification, that is, fine particles that are atomized to the order of the fine structure inside the fiber. They can be made to appear by elution and erosion of the surface of fibers to which the fine particles have been added. That is,
A sol of a particulate inert substance with an average diameter of 100 millimicrons or less, preferably 60 millimicrons or less, is added to the glycol component in advance to dilute it, or/and the acid component and the glycol component are mixed together. It is added to the slurry and diluted, and the diluted sol is subjected to an esterification reaction or transesterification reaction so that the content of inert fine particles is 0.5 to 10% by weight based on the produced polymer. Add to the system before the start of the reaction, or after the start of the reaction: ii) In the transesterification method, each is added to the transesterification reaction system at a temperature of 235°C or lower in the case of a continuous method or 200°C or lower in the case of a batch method, and the reaction is carried out to obtain an esterified product or transesterified product, respectively. Then, the esterified product or the transesterified product is polymerized to obtain a polyester polymer having a number average degree of polymerization of 70 or more, and the polyester polymer is melt-spun by a conventional method to obtain a 0.1 to 0.5 micron particle consisting of the inert fine particles. There are at least 5 micron secondary particles per 10 square microns, and the particle size is 5
When a fine particle-containing polyester fiber is produced in which there are no more than 20 secondary particles larger than microns in one cubic millimeter of fiber, and the fiber surface layer of the obtained polyester fiber is eluted with a solvent for the fiber,
It was found that non-uniform elution occurs in the microscopic higher-order structure inside the fiber containing fine particles, resulting in extremely fine and complex irregularities appearing on the entire fiber surface. In particular, it has been found that silica sol as a fine particle has good properties in terms of appearance of extremely fine irregularities and stability in processes such as spinning and stretching. For example, 3% by weight of silica with a particle size of 30 mm and a specific gravity of 2.2 g/ ^cm3 is contained in a polyester fiber with a specific gravity of 1.39.
A simple calculation shows that the volume of polyester occupied by one fine particle when uniformly dispersed is approximately
It becomes a cube of 900 angstroms, and the particle size
Similarly, when 15 millimicrons of silica is uniformly dispersed in polyester fibers at 3% by weight, the polyester mass occupied by one single particle is calculated as a cube with one side of about 450 angstroms. It is thought that such a fine high-order structure ranging from several hundred angstroms to about 1,000 angstroms causes non-uniform elution during elution of the fiber surface layer, resulting in the fiber surface having a fine and complicated uneven shape. The added fine particles exist in a single particle state or in a so-called secondary particle state in which single particles are aggregated.
This means that the chip before spinning or the fiber after spinning is larger than the diameter of the single particulate fine particles present in the chip or fiber, and within a thickness of several times the particle diameter.
That is, slice it with an ultramicrotome to a thickness of several tens of millimeters to around 100 millimeters,
It can be observed by enlarging the sliced ultra-thin sections at high magnification using a transmission electron microscope. When the fiber surface is eluted, the non-uniform elution is also affected by the state of dispersion of these fine particles. In the case of completely uniform dispersion of single particles, during elution from the fiber surface,
It is difficult to form irregularities that are several times the diameter of a single particle or more, but in the case of a moderately non-uniform dispersion state, during surface elution, areas with a high density of particles tend to be eroded and eluted, and areas with a low density tend to elute. The concave portion becomes larger and a desirable uneven state is created. It is important that these irregularities occur randomly and uniformly over the entire surface of the fiber. In the present invention, secondary particles are defined as particles in which single particles approach each other at a distance smaller than the diameter of the single particle, that is, the distance between the centers of adjacent single particles is less than twice the diameter. The maximum distance from one end of the secondary particle to the other is defined as the size of the secondary particle. A secondary particle according to this definition is the aforementioned electron micrograph that has been enlarged to the extent that a single particle size can be identified, for example, if the particle size is 10 millimicrons.
A photograph magnified at least 100,000 times (100,000 times or more if the size is 100 millimicrons) allows for the identification of single particles and secondary particles formed from them. That is, in the present invention, an ultra-thin section with a thickness of 50 to 100 millimeters is made, an enlarged photograph is obtained from the section with a transmission electron microscope to the extent that the single particle diameter can be identified, and the secondary particles are determined from the photograph. This is to determine the dispersion state. According to the studies of the present inventors, a state in which at least 5 secondary particles of 0.1 to 0.5 microns exist per 10 square microns by the above method produces the preferable random unevenness and fine unevenness of the present invention. I found out what to do. However, an extremely agglomerated state of single particles is undesirable because it becomes an unstable factor in the fiber manufacturing process, and it is preferable that 1 mm ³ of the polymer does not contain more than 20 secondary particles with a particle size of more than 5 microns. As an example of obtaining the above-mentioned polyester polymer, it is recommended to use colloidal silica in which fine silica particles with an average particle size of 1 millimicron to 100 millimicrons exist in the form of single particles. This colloidal silica is one in which fine particles containing silicon oxide as a main component exist as a colloid using water, monohydric alcohols, diols, or a mixture thereof as a dispersion medium. When producing a polyester polymer by the direct esterification method, the method of adding colloidal silica to the esterification tank is to add it in advance to a slurry of an acid component and a glycol component and then supply the slurry to the esterification tank. Another method is to add colloidal silica directly to the esterification tank. In the former case, the colloidal silica is preferably first mixed with the glycol component, thoroughly stirred, and then mixed with the acid component to form a slurry. The concentration of colloidal silica before adding to the slurry is preferably 80% or less of the critical concentration (the concentration at which colloids begin to aggregate), but if the concentration is too low, the amount of dispersion medium in the slurry will increase, which is undesirable. .
However, the concentration should be as low as possible. The molar ratio of the glycol component to the acid component is preferably larger in order to improve the dispersibility of the silica particles, but if it is too large, undesirable by-products such as diethylene glycol will increase, for example. The molar ratio should be in the range of 1.01 to 2.0, preferably 1.05 to 1.60, since harmful effects may occur. Further, the slurry is preferably adjusted at a temperature ranging from room temperature to about 100°C and below 120°C. After the slurry is prepared, it may be heated to 120° C. or higher, and heating is more preferable from the standpoint of the esterification step and from the standpoint of improving the dispersion of the silica fine particles. In the case of the latter (direct addition of colloidal silica),
Preferably, the concentration of colloidal silica is as low as possible. For example, when trying to obtain a polyethylene terephthalate polymer, it is recommended to reduce the colloidal silica concentration as much as possible using ethylene glycol. However, if the amount of ethylene glycol is too large, other disadvantages will occur, such as the by-product of diethylene glycol, so the molar ratio of the total glycol component to acid component in the system should be adjusted within a range that does not exceed 2.5. . The silica fine particles are prepared as described above and supplied to the esterification tank. Incidentally, the dispersibility of the silica fine particles is mainly controlled by the temperature of the system at the time of supplying the slurry. That is, if the temperature of the system is too high, the silica fine particles tend to aggregate due to heat shock, and once aggregated, it is almost impossible to redisperse them. Therefore, in the case of continuous polymerization, the temperature of the system should be below 295°C, more preferably below 290°C.
In addition, in the case of batch polymerization, the temperature of the system should be kept below 280℃.
More preferably, the temperature should be 260°C or lower. When attempting to obtain a polyester polymer by a transesterification method, an aqueous dispersion medium of colloidal silica is not preferred because it inhibits the transesterification reaction. In the case of an aqueous dispersion medium, it is necessary to expel water before the transesterification reaction. Colloidal silica is added to the system before the start of the transesterification reaction.
Most preferred in terms of preventing heat shock. When added to the system during or after transesterification, the temperature of the system should be below 235°C for continuous polymerization, more preferably below 215°C, to prevent agglomeration due to heat shock as mentioned above. .
In the case of batch polymerization, the temperature should be 200°C or lower, more preferably 160°C or lower. In any of the above cases, the molar ratio between the glycol component and the acid component is preferably higher from the viewpoint of dispersibility of silica, but the opposite is true from the viewpoint of by-products, and the molar ratio is preferably 3.0 or less. is preferably 2.5 or less. When performing polycondensation, it is more preferable to stir the reaction system as strongly as possible within a reasonable range to apply a large shear stress to the system, from the viewpoint of improving the dispersibility of the silica fine particles. When the reaction system is stirred under the same conditions, in order to increase the shear stress, it is sufficient to increase the degree of polymerization, that is, the viscosity of the system, as much as possible within the practical range and the intended purpose. From this point of view, it is necessary that the number average degree of polymerization is at least 70 or more, preferably 90 or more. Further, if the number average degree of polymerization of the polyester polymer does not exceed 70, sufficient strength for obtaining fibers or films cannot be obtained, and in addition, it is not preferable for dispersing the silica fine particles. This method uses a polyester polymer containing fine particles produced by the above production method and having a number average degree of polymerization of 70 or more, spinning by a conventional method,
Fibers are obtained by stretching or the like. In this case, if the fine particles added to the polymer exceed 100 millimicrons, X, which indicates the unevenness after elution of the fiber surface layer, will increase, and the unevenness forming a random surface will decrease.
It is undesirable that the color becomes dull and the whiteness becomes noticeable after dyeing. Therefore, in order to uniformly disperse the fine particles, improve process stability during spinning and drawing, and improve gloss and color depth effects, the fine particle diameter should be 100 millimeters or less, preferably 60 millimeters. The following are desirable. Examples of such fine particles include silica sol, fine particulate silica, alumina sol, fine particulate alumina, ultrafine titanium oxide, calcium carbonate sol, fine particulate calcium carbonate, modified silica sol with good dispersion stability, or other polyesters. Colloids of particulate inert substances with a refractive index close to that of the fibers are used, but the transparency of the fibers
Silica sol was the most effective in terms of color clarity and good gloss. As a result of examining the amount of the fine particles added, it was found that if the amount is less than 0.5% by weight, the unevenness after elution of the surface layer becomes insufficient and no improvement effect on color depth or gloss is observed. 10% by weight of fine particles
If it is added in excess of this amount, spinning becomes extremely difficult and becomes practically impossible. The fine particles
Polyester fibers made by melt-spinning a polymer component containing 0.5 to 10% by weight have a fiber surface shape after stretching that shows streaks in the fiber axis direction, but does not have a finely uneven surface. The above-mentioned surface irregularities can only be achieved by dissolving the fiber surface layer with a solvent that is soluble or decomposable for polyester fibers. When dyeing woven or knitted fabrics, it is preferable to perform elution treatment before dyeing to prevent elution erosion on the fiber surface, and when dyeing yarn or cotton, it is preferable to treat elution corrosion on the cotton, thread, or tow state before dyeing. Processing is preferable in terms of color matching of dyeing. However, even if it is carried out after dyeing, a fine and complex surface unevenness shape will still be obtained, and the surface elution treatment may be selected as appropriate at a desired step. Alkali treatment such as caustic soda is used as an elution and erosion treatment for polyester synthetic fibers, but
It is not limited to this. However, it is preferable to select a common solvent for the polyester component constituting the fiber and the fine particles added to the fiber. Furthermore, it is more preferable to use a common solvent in which the rate of dissolution or decomposition of fine particles is several times to several tens of times higher than that of polyester, since this will make the unevenness on the fiber surface more fine and complex. In this respect, if the fine particles added are silica and the solvent is caustic soda, the dissolution rate of silica is more than 10 times faster than that of polyester, making this an extremely desirable combination. As mentioned above, the fibers used in this method have fine particles in the polyester fibers that are well dispersed in the form of single particles and have a size of 0.1 micron to 0.1 micron.
Secondary particles of 0.5 microns in diameter that are not excessively aggregated exist in a well-dispersed manner. Therefore, when a fiber containing fine particles is treated with an alkali, a large number of fine particles present on the surface of the fiber are first eluted, and from that elution point, fine particles surrounding the inside of the fiber are further eluted one after another in a three-dimensional and non-uniform manner. Therefore, the fine pores formed as a result of its elution become fine and complex pores that penetrate not only in the axial direction of the fiber but also in the circumferential direction of the fiber, and these many pores are independent or partially formed. It overlaps to form extremely fine and irregular irregularities. Conventionally, plasma irradiation is a well-known method for making the surface of fibers uneven, but the unevenness formed on the fiber surface by this plasma irradiation method is regular and uniform as mentioned above, The fibers of the invention are distinguished from those produced by the plasma irradiation method in terms of the difference in the direction of the unevenness and the random size and shape of the unevenness. Furthermore, in the method of the present invention, once the surface irregularities are formed, even if the surface is subjected to surface elution treatment again, the fine particles are uniformly present inside the fibers, so that the surface irregularities as described above can be formed. . In this respect, it is difficult to provide a surface recovery phenomenon when the fiber surface is roughened by plasma irradiation or by foaming. However, the method of the present invention has the unique advantage that when the degree of surface elution reaches 10 to 15% or more in terms of weight loss, a similar surface shape can be obtained even if the surface elution treatment is performed again. Moreover, this is a major feature, as even if the process order is changed, the desired surface shape can be obtained as long as the surface elution treatment is applied, and reprocessing of the dyed product is possible at the product finishing stage. It is something that exists. The change in frictional properties of the polyester fibers obtained by this method as described above before and after treatment with alkali is also unique. That is, before treatment with alkali, the fiber surface has no fine irregularities and exhibits only the same frictional properties as ordinary polyester fiber. However, when this fiber is treated with alkali, the coefficient of static friction between the fibers μs and the coefficient of kinetic friction μd before the alkali treatment are
Compared to the difference (μs-μd) between the fibers and the fibers, the μs-μd after the treatment increases significantly, and the result is a fiber with an excellent slip texture with a μs/μd of at least 1.6 after the treatment. Moreover, this μs-μd increases as the elution rate of the fiber surface increases by treatment with alkali, and the dry feel, creaking, and silky characteristics of silk are obtained. As can be understood from the above explanation, the present invention aims to achieve the intended purpose by giving the fiber surface a unique structure. Needless to say, it can also be applied to manufacturing methods. In this case, fine particles with a diameter of 100 millimicrons or less, preferably 60 millimicrons or less,
Preferably, a polyester polymer containing 0.5 to 10% by weight of silica sol is used as the sheath component or one of the dorsal and abdominal components, and the core component or other dorsal and ventral components contain the above-mentioned fine particles or have different contents. A fiber in which a polymer or a different kind of polymer or a same or different kind of polymer containing no fine particles is arranged, and the surface layer of the fiber is eluted and eroded using a solvent that is soluble or decomposable for the polyester polymer. It is also possible to make synthetic fibers that have finer and more complex irregularities randomly on the fiber surface, and to bring out their characteristics even more by changing the texture, gloss, and texture. Furthermore, the present invention can be made into a shape similar to a pentagon or hexagon by high-order processing such as false twisting and crimp processing,
Trilobal, T-shaped, and 4-shaped fibers are produced by the irregular cross-section nozzle during spinning.
Needless to say, it may be used in a multi-lobed shape such as a leaf shape, a five-lobed shape, a six-lobed shape, a seven-lobed shape, an eight-lobed shape, etc., and various cross-sectional shapes. The false twisted yarn according to the present invention exhibits the effect of reducing glitter. Therefore, it is advantageous in that it also exhibits an anti-glitter effect on the POY DTY false twisted yarn obtained by high-speed spinning. The polyester polymer referred to in the present invention means that at least about 75% of the repeating structural units are

[Formula] (where -G- is a divalent organic group containing 2 to 18 carbon atoms and connected to the adjacent oxygen atom through a saturated carbon atom) is a glycol dicarboxylate repeating structural unit such as It is. The terephthalate group may be the only dicarboxylate component of the repeating structural unit, or up to about 25% of the repeating structural unit may be an adipate, sebacate, isophthalate,
bibenzoate, hexahydroterephthalate,
Other dicarboxylates such as diphenoxyethane-4,4'-dicarboxylate and 5-sulfoisophthalate groups may also be included. Examples of glycols include polymethylene glycols such as ethylene glycol, tetramethylene glycol, hexamethylene glycol, and 2,2-dimethyl-
Branched chain glycols such as 1,3-propanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, or mixtures thereof can also be used. If desired, up to about 15% by weight of higher glycols such as high molecular weight polyethylene glycols can also be used. Various other substances such as matting agents, gloss improvers, anti-tarnish agents, etc. may also be added to the polymerization mixture if desired. Next, the present invention will be explained with reference to examples, but the present invention is not limited to the following examples. Example 1 An aqueous silica sol having a particle size distribution in the range of 10 to 20 millimicrons and having a concentration of 20% by weight was mixed with ethylene glycol at room temperature, and after thorough stirring, terephthalic acid and the molar ratio of the ethylene glycol and terephthalic acid were mixed. The ratio was adjusted to 1.2 and mixed to obtain a slurry containing silica. This slurry was continuously fed to a batch type esterification tank with a reaction system temperature of 250℃ and an internal pressure of 1.2Kg/cm ² to perform esterification to obtain an esterified product with an esterification rate of 98%, and then the slurry was heated to 285℃. Polymerization was carried out to obtain a polyester polymer with a number average degree of polymerization of 95. Note that Sb ₂ O ₃ was used as a polymerization catalyst. According to the manufacturing method of such polymers, the amount of silica sol added was varied from 0.1% by weight to 15% by weight, each polymer was created, and each was melt-spun.
A drawn yarn of 150 denier and 30 filaments was obtained by ordinary drawing. In the case of 12% by weight and 15% by weight of silica sol, the spinnability was poor and no samples could be obtained. The obtained drawn yarn is subjected to false twisting,
A knitted fabric was created using each of the obtained samples. Each knitted fabric was subjected to alkali weight loss treatment in a 4% by weight caustic soda solution at 95°C. The alkali weight loss rate was checked for each sample, and care was taken to keep it within 3% or more and 6% or less. After each knitted fabric was dyed using the following method, the reflectance of the knitted fabric was measured using a self-recording spectrophotometer model EPR-2 manufactured by Hitachi, and changes in color depth were determined from changes in reflectance.
The uneven shape of the fiber surface was determined from the scanning electron micrograph, and the results are shown in Table 1. Dyeing method Dye: Mitsubishi Kasei Dianix Black HG-SE12%
owf Dispersion and leveling agent: Toho Salt manufactured by Toho Chemical Co., Ltd.
TD0.5g/PH adjuster: Miteshima Chemical ultra MT-N ₂ 0.7
g/bath ratio: 1:30 Temperature rise: Reduction cleaning Hydrosulfite 1g/ Caustic soda (36°B) 1g/ Nonionic activator 1g/ 80℃ x 10
minutes

[Table] When the silica sol was 0.1%, the fiber surface did not have a random surface, and the X, which represents an uneven shape, was 0.7 microns or more. In addition, there is little decrease in reflectance,
No depth of color was developed, and no improvement in gloss was observed. On the other hand, those to which 0.5% or more of silica sol is added have fine irregularities consisting of walls with a granular structure of 50 to 200 millimicrons, and furthermore, a random surface of irregular irregularities including these fine irregularities is formed on the fiber surface. It had been. And although X is not constant,
Asperities satisfying 0.2 to 0.7 microns were present at a density of 10 to 45 per 10 microns of length in the outer circumferential direction perpendicular to the fiber axis. In these cases, a decrease in reflectance was observed, the depth of the black color increased, and the gloss became smooth and good. In Table 1, the silica sol content is 0.5% by weight.
In the above cases, although the differences in color depth and gloss are not clearly shown, the greater the amount added, the deeper the color and the better the gloss. Furthermore, each knitted fabric with a silica sol content of 0.5% by weight or more clearly exhibited an improvement effect on slip hand. Comparative Example 1 Using the same silica sol as in Example 1, Example 1 was prepared so that the silica was 3% by weight based on the polymer.
It was prepared as a slurry under the same conditions. This slurry was supplied to an esterification tank having a reaction system temperature of 285° C. under the same conditions as in Example 1, and esterification and polymerization were performed to obtain a polymer having a number average degree of polymerization of 90. When this polymer was spun, the pressure suddenly increased in just one hour, making it impossible to spin, and the spinning yarns were frequently broken. When this polymer was observed using a phase contrast microscope, it was found that there was severe agglomeration of silica, with more than 60 secondary particles having a particle size exceeding 5 microns per cubic millimeter of polymer. Comparative Example 2 Using the same silica sol as in Example 1, Example 1 was prepared so that the silica was 3% by weight based on the polymer.
It was prepared as a slurry under the same conditions. This slurry was esterified and polymerized under the same conditions as in Example 1 to obtain a polymer with a low number average degree of polymerization of 65. When this polymer was spun and drawn, yarn breakage occurred frequently during spinning due to the weak polymer strength, and yarn breakage and fuzz occurred frequently during drawing, resulting in no product that could be used as fiber. When the polymer was observed under an electron microscope, it was found that the silica particles were dispersed to approximately the same degree as in Example 6, and the dispersibility was good. Example 2 Using the various types of fine particles described below, polyester polymers containing fine particles were produced in the same manner as in Example 1 so that the fine particles accounted for 1.5% by weight of the polymer. Each of these polymers was melt-spun using a conventional method and water bath stretched to produce cut staples of 2.5 denier and 51 mm, and spun yarns of 30'S/1 were produced to form knitted fabrics. Perform alkali reduction and dyeing as shown in Example 1,
The uneven shape of the fiber surface and changes in color depth and gloss of the knitted fabric after dyeing were investigated, and the results are shown in Table 2. As the particle size increases, the depth of color and luster are lost, and the worst example was titanium oxide (approximately 200 millimicrons). Silica sol with a particle size of about 150 mm to 120 mm and a particle size of about 80
Calcium carbonate from millimicrons to 100 millimicrons has a color depth effect of 1, but its quality is inferior to that of particles with small particle sizes, and when the alkali weight loss rate is increased, the color changes due to the occurrence of large irregularities of 0.7 microns or more. Dullness is starting to appear. In the case of alumina powder, the single particle diameter is about 20 millimeters, but in actual spinning conditions, the pressure rise was so severe that a good dispersion state of the fine particles in the polymer could not be obtained. As a result, X as defined in the present invention was 0.7 microns or more, and there was no improvement effect on color depth or gloss. Even when silica powder with a particle size of about 7 mm and fine titanium oxide powder with a particle size of about 30 mm were used, deep black color and good gloss were obtained in both cases.
In the end, silica sol with a particle size of 80 to 90 millimicrons is suitable in all respects;
Silica sols from 10 to 60 millimicrons were superior.

[Table] *Depth of black color: Determination by sensory test
The higher the value, the deeper the color, and the lower the value, the duller the color.
Example 3 Using an aqueous silica sol with a particle size of approximately 45 millimicrons and a concentration of 40% by weight, Polymer A was prepared in the same manner as in Example 1, with an amount of 3% by weight added to the silica sol.
I got it. The intrinsic viscosity of this was measured as a solution of orthochlorophenol at 25°C and was 0.51. Separately, polyethylene terephthalate B containing no additives and having an intrinsic viscosity of 0.75 was prepared. Eccentric type core-sheath composite spinning was performed by combining component A and component B. At this time, A component is used as a sheath component, and B
The component was made into an eccentric core component. After composite spinning, it was drawn and then passed through a hollow heater at 185° C. for overfeeding to develop latent crimp, to obtain a crimped yarn of 75 denier and 36 filaments. Titanium oxide (particle size approx. 200
A false-twisted yarn of 75 denier 36 filament polyester filament containing 0.02% by weight (millimicrons) was prepared. Each of these two types of yarn has a vertical density of 125
A 2/2 twill fabric with a width of 95 lines/inch and a width density of 95 lines/inch was created. In each conventional dyeing process, the fiber surface was subjected to elution erosion treatment after heat setting. Caustic soda was used as the solvent, and the surface was leached and eroded by reducing the amount by about 15%. Following this, a normal dyeing finish was carried out and the texture and appearance were evaluated. The polyester eccentric core-sheath composite yarn using the A component and the B component has a soft and supple texture and is similar to pure silk twill habutae, and is superior to the polyester false twisted yarn of the control sample in terms of color development and depth of color. It was far superior. Example 4 Using polymers A and B obtained in Example 3,
A composite fiber with a back structure was melt-spun using a conventional device. The composite ratio was A:B=6:4. After stretching, the yarn was passed through a hollow heater at 180° C. at an overfeed rate of 50% to undergo a relaxation treatment to develop latent crimp, thereby obtaining a crimped yarn of 75 denier and 36 filaments. A knitted fabric was prepared from this crimped yarn and subjected to heat treatment and caustic soda treatment in the same manner as in Example 3 to reduce the weight by approximately 10%. When the fibers were taken out from the knitted fabric and the surface was observed using a scanning electron microscope photograph, it was found that the fine and uneven tandem surface described in the present invention was observed on the outside of the crimped form over approximately 60% of the fiber perimeter length. It was done. The knitted fabric sample had no sparkling luster even in direct sunlight and was soft and supple to the touch. Example 5 An aqueous silica sol having an average particle size of 15 mm and a concentration of 20% by weight was mixed with ethylene glycol at room temperature, thoroughly stirred, and then mixed with terephthalic acid to form a slurry. Next, this slurry was subjected to esterification and polycondensation, and the intrinsic viscosity [η] was 0.67.
Polyethylene terephthalate containing 3% by weight of silica was obtained. In addition, the average particle size is 45 millimicrons, and the concentration is 20% by weight.
Polyethylene terephthalate having an intrinsic viscosity [η] of 0.69 and containing 3% by weight of silica was obtained in the same manner as above using the aqueous silica sol. As a control, polyethylene terephthalate having an intrinsic viscosity [η] of 0.69 and containing 0.45% by weight of titanium oxide was obtained by using titanium oxide having an average particle size of 200 millimicrons and performing the same operation as above. Each polymer was then spun and drawn in a conventional manner to create fibers with a round cross section (75 denier,
36 filaments) and T-shaped cross-section fibers (75 denier, 36 filaments) were obtained, respectively. The filament yarn is twisted at 250T/M in the Z direction, resulting in a raw density of 104/inches (vertical), 85/inches/inches (horizontal), and a finished density of vertical (vertical).
Created a habutae fabric of 119 pieces/inch and 100 pieces/inch horizontally. In the scouring and finishing process of textiles, the fiber surface was subjected to elution treatment using a caustic soda solution after heat setting. Table 3 shows the weight loss rate and the sensory test results for the feel of Habutae. On the other hand, in order to more accurately grasp the frictional behavior of filament yarns, the filament yarns used in textiles are made into a skein shape in advance, subjected to scouring treatment and heat history under the same conditions as those used in the scouring and finishing process of textiles, and then subjected to fiber surface elution treatment. I did it. The elution treatment conditions at this time were the same as those for the woven fabric. Regarding the thus obtained filament yarn after the surface elution treatment, the uneven shape of the fiber surface was observed using a scanning electron microscope photograph, and the friction coefficient between the yarns was measured using the radar method defined above. The surface of filament yarn is 50 to 200
Millimicron fine irregularities were present over the entire surface, and furthermore, there was a random surface with large irregular irregularities including these fine irregularities. The irregularities forming this random surface are
The unevenness satisfying 0.2 to 0.7 microns is 13 per 10 microns in the outer circumferential direction perpendicular to the fiber axis.
They existed at a density of 40 to 40. The values of the static friction coefficient μs, dynamic friction coefficient μd, and μs/μd of these filament yarns are also listed in Table 3.
As a control, measurements were also conducted on samples that had not been subjected to surface elution treatment. The sample in this case also underwent the same history as the others except for the elution process. As can be seen from Table 3, the yarn according to the present invention has a significantly increased μs due to the surface elution treatment.
μs/μd has increased to more than 1.7 and around 2.3. A clear correspondence between μs/μd and the texture sensory test results of Habutae textiles was also observed. That is, when μs/μd is 1.7 or more, the tactile sensation begins to change, the slimy feeling disappears, and a squeaky feeling appears. In particular, when μs/μd was 1.9 or higher, the occurrence of silk ringing peculiar to silk was observed.
When we created various types of fabrics other than habutae, which are made of fiber threads that cause ringing and squeaks, we found that neckties are less likely to tighten or lose their shape, and scarves are dry and smooth. In addition, blouses and dresses have a smooth and cool feel similar to silk, making it possible to create products with a new feel that was unimaginable with conventional polyester synthetic fiber fabrics.

[Table] * The higher the sensory test value, the higher the sensory value ** +
...with ringing, -...without ringing Example 6 The main components are ethylene glycol, terephthalic acid, and isophthalic acid, and the polymerization catalyst Sb ₂ O ₃ is used.
Aqueous colloidal silica containing 400 ppm and having a molar ratio of terephthalic acid to isophthalic acid of 92:8 and a molar ratio of ethylene glycol to terephthalic acid of 1.5 has a diameter of 45 millimicrons and a concentration of 20% by weight. was added so that the amount of silica particles was 5% by weight based on the produced polyester, and the mixture was sufficiently stirred to prepare a slurry. Next, the slurry was continuously supplied to an esterification tank with a reaction system temperature of 250°C and an internal pressure of 2 kg/cm ² for 4 hours to perform esterification, and further esterification was performed while raising the temperature to 265°C. An esterified product with an esterification rate of 96.5% was obtained. Subsequently, polymerization was carried out at 285°C to obtain a polyester polymer with a number average degree of polymerization of 90. When this polymer was spun and stretched, it passed through the process very smoothly. When this polymer was observed with an electron microscope, there were an average of 60 secondary particles of 0.1 to 0.5 microns per 10 square microns, and secondary particles with a particle size of more than 5 microns were found to be 1 cubic meter (mm
³ ), and the dispersibility of the added silica was extremely good. Example 7 An esterification tank containing ethylene glycol and terephthalic acid as main components, a molar ratio of ethylene glycol and terephthalic acid of 1.2, an esterification rate of 85%, and a reaction system temperature of 230°C, with ethylene glycol as the dispersion medium. Colloidal silica with a concentration of 30% by weight and a diameter of 25 mm is continuously supplied over 1 hour in an amount such that the silica particles are 7% by weight relative to the polymer produced, and then esterification is completed. This was followed by polycondensation to obtain silica-containing polyethylene terephthalate having a number average degree of polymerization of 95.
When this was spun and stretched, it passed through the process smoothly. When this polymer was observed under an electron microscope
Approximately 200 secondary particles of 0.1 to 0.5 microns were present per 10 square microns, and almost no secondary particles larger than 5 microns in size were found. Example 8 Sodium salt of dimethyl terephthalate and dimethyl 5-sulfoisophthalate (molar ratio 97.5:2.5)
ethylene glycol was adjusted so that the molar ratio of ethylene glycol and acid component was 2.2,
This was combined with sodium acetate as a transesterification catalyst.
Colloidal silica with a diameter of 15 millimicrons and a concentration of 20% by weight using methanol as a dispersion medium is added to a system in which 1000ppm of colloidal silica is added, and a batch type ester is added so that the silica particles account for 0.5% by weight of the resulting polymer. added to the exchange tank. This is heated to perform transesterification and polycondensation, resulting in a number average polymerization degree of 80.
A polyester polymer was obtained. When this was spun and drawn, it passed through the process smoothly. When this polymer was observed under an electron microscope, it was 0.1 to 0.5.
There were about 6 micron secondary particles per 10 square microns, and almost no secondary particles larger than 5 microns were found, indicating that the silica particles had good dispersibility.

[Brief explanation of the drawing]

Figures 1 and 2 are general examples of surface cross-sectional curves, with Figure 1 showing a regular surface and Figure 2 showing a regular surface.
The figure illustrates a random surface. FIG. 3 schematically shows the uneven shape of the present invention. Figures 4 to 6 are examples of scanning electron micrographs showing the surface conditions of the fibers of the present invention.
The magnification is 3000x, and both Figures 5 and 6 are 24000x magnification. Figure 7 is an example of a scanning electron micrograph showing the surface condition of ordinary polyester fibers subjected to ordinary alkali treatment.
The magnification is 6000x.

Claims (1)

[Claims] 1 a. A sol of inert fine particles with an average particle size of 100 microns or less is added in advance to the glycol component and diluted, or/and added to the slurry of the acid component and the glycol component. (b) before the start of the esterification reaction or transesterification reaction, so that the content of inert fine particles is 0.5 to 10% by weight with respect to the resulting polymer; (i) Add it to the esterification reaction system after the start of the reaction at a temperature of 295°C or less in the case of a continuous method or 200°C or less in the case of a batch method; (ii) In the transesterification method, each is added to the transesterification reaction system at a temperature of 235°C or lower in the case of a continuous method or 200°C or lower in the case of a batch method, and the reaction is carried out to obtain an esterified product or transesterified product, respectively, c. Subsequently, the esterified product or the transesterified product is polymerized to obtain a polyester polymer having a number average degree of polymerization of 70 or more, and d) the polyester polymer is melt-spun by a conventional method to obtain 0.1 to 0.5 microns of the inert fine particles. Producing fine particle-containing polyester fibers in which there are at least 5 secondary particles defined below microns per 10 square microns, and where there are no more than 20 secondary particles with a particle size exceeding 5 microns per cubic millimeter of fiber. and (e) a method for producing a polyester synthetic fiber, which comprises subjecting the surface of the obtained fiber to elution and erosion treatment with a solvent that is soluble or decomposable for the fiber. However, secondary particles are a group of particles in which the distance between the centers of adjacent single particles is less than twice the diameter of a single particle, as seen in an electron micrograph magnified to the extent that the single particle diameter can be identified. is a secondary particle.