JPS6233346B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a fabric made of polyester fibers having a deep black color. Conventionally, polyester fibers have been considered to have poor color development compared to natural fibers such as wool and silk, or rayon, triacetate, acrylic, etc. obtained by wet spinning or dry spinning. Chromaticity is classified into the vividness of the color and the depth of the color. The vividness of a color means that both chroma and brightness are high, and the depth of a color means that the chroma is high and the brightness is low. Factors that affect color development include the refractive index of the fiber, cross-sectional shape, surface unevenness, type of dye used, amount of dyeing, etc., and research to improve these factors has been conducted for many years, and polyester There was some improvement in the vividness of the fiber color. For example, there are cationically dyeable polyesters copolymerized with sulfoisophthalic acid. However, there is still no significant improvement in deep colors. In particular, black dyed materials have a so-called "white discoloration" phenomenon in which they appear more whitish than true black.
This is not the preferred black dyed product obtained with triacetate, rayon, wool, etc., and has become a very important topic among those involved in textile research and development. The present inventors have repeatedly researched polyester fibers having a deep black color, and have finally developed a fabric made of polyester fibers having a deeper black color than wool. That is, in the present invention, after or before a polyester fiber containing W weight % of silica is made into a fabric, the weight loss rate WL (%) of the fiber and silica is reduced by WL (%)≧3+20/ A fabric made of polyester fibers that has undergone a weight loss elution treatment to form irregular irregularities on the fiber surface to satisfy W ³ , and the black dyeing of the fabric is compliant with the Japanese Industrial Standards (JIS Z8722, When measuring reflected light under the conditions specified in JIS Z8727), the special spectral reflection ratio S (=R/Ro), defined as the ratio of the amount of reflection R to the amount Ro of reflection of a black sample as a control, is
Over the visible light range from mm to 650 mm 1/S≧0.75+aT√/30929 [where T: number of actual twists or false twists of the basic yarns constituting the fabric, times/m Dr: basic yarns constituting the fabric Denier a of the strip: twist correction value (actual twist, a=1 for untwisted, a=0.56 for false twist)] Made of polyester fiber with a deep black color. It is related to fabric. In the present invention, polyester refers to aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalene-2,6-dicarboxylic acid, fatty acid dicarboxylic acids such as phthalic acid, adipic acid, and sebacic acid, or their esters, and ethylene glycol. diethylene glycol, 1-4-butanediol,
Neopentyl glycol, dichlorohexane
It is a polyester synthesized from a diol compound such as 1,4-dimethanol, and particularly preferably a polyester in which 80% or more of the repeating structural units are ethylene terephthalate units. In addition, the above polyester component is copolymerized with polyalkylene glycol, glycerin, pentaerythritol, methoxypolyalkylene glycol, bisphenol A, sulfoisophthalic acid, etc., or 5% by weight.
A mixture of the following additives, such as a matting agent, a heat stabilizer, a face weight, etc., may also be used. Furthermore, polyester fibers may of course be short fibers or long fibers, and also include conjugates of polyester fibers and other fibers, core-sheath fibers, multicore core-sheath fibers, and the like. In the present invention, the irregular irregularities on the fiber surface refer to the fact that the fiber surface forms a random surface, and within the random surface, a multilayered structure of irregularities having finer irregularities is formed. The large irregularities forming the random surface mainly mean irregularities on the order of visible light wavelength, and the fine irregularities mean fine irregularities of 50 to 200 millimicrons. Here, a random surface typically means a surface with a mixture of convex parts with irregular peak heights and concave parts with irregular valley depths, but the height of the peaks of the convex parts is approximately Similarly, a surface in which the depth of the valleys of the concave portions is irregular, and conversely, a surface in which the depth of the valleys in the concave portions are approximately the same but the height of the peaks of the convex portions are irregular are also included as random surfaces. In this fiber, the above-mentioned fine irregularities are present all over the entire area of the concave or convex parts themselves, singly or partially overlapping, and have extremely fine and complex irregularities. It is thought that its presence contributes to its effect. Various surface roughening methods have been proposed in the past, but none have yet been able to form such a random surface with fine and irregular irregularities, and therefore there have been no reports that color development has been improved by surface roughening. 1st
The figure schematically shows the surface condition of the roughened fiber obtained by the method of the present invention in a cross-sectional view. Black dots indicate silica particles. As shown in FIG. 1, the present invention involves appropriately dispersing silica in a polymer, and hence in a fiber, in the form of a single particle or in a state close to a single particle state in which several particles are aggregated. It is obtained by eluting the surface with a common solvent for fibers and silica, and the dissolution rate of silica and polyester fibers in the common solvent is significantly higher for silica, so areas with dense silica distribution elute quickly. , which appears to form a complex random surface. Such a unique surface unevenness structure of the order mentioned above is more highly atomized than the particle size of the fine particulate inert substance conventionally used for fiber modification, that is, the fine structure inside the fiber. Skillfully utilizes fine particles that have been atomized to order,
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, the average diameter of the fine particles is 100 millimicrons or less, preferably
0.5 to 60 millimicrons or less of silica particles
A polyester fiber containing 10% by weight of polyethylene terephthalate is melt-spun and drawn to produce a polyester fiber, and the resulting polyester fiber is preferably made into a yarn or made into a fabric with a solvent for the fiber. When the fiber surface layer is eluted with a common solvent for the fiber and the added fine particles, the fine higher-order structure inside the fiber containing the fine particles becomes unevenly eluted, and an extremely fine and complex uneven shape is formed on the entire fiber surface. It is possible. Among the silica to be added, in particular, sol-state silica, that is, colloidal silica, has good properties in terms of appearance of extremely fine irregularities and stability in processes such as spinning and stretching. 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. If the silica particles added to the polymer exceed 100 millimicrons, the irregularities that form the random surface after elution of the fiber surface layer will increase, and the irregularities that form the random surface will decrease, resulting in dull color and white spots after dyeing. It becomes noticeable and undesirable. Therefore, in order to uniformly disperse silica particles, improve the process stability during spinning and drawing, and improve the effects of gloss and color depth, the particle size must be adjusted.
The thickness is desirably 100 millimicrons or less, preferably 60 millimicrons or less. The fine particles referred to in the present invention include, for example, silica sol,
Particulate silica refers to modified silica sol with improved dispersion stability. As a result of examining the amount of silica fine particles added, if it is less than 0.5% by weight,
The unevenness after elution of the surface layer is insufficient, and no improvement effect on color depth or gloss is observed. If more than 10% by weight of fine particles is added, spinning becomes extremely difficult and practically impossible. When dyeing textiles in the form of woven or knitted fabrics, it is preferable to perform elution and erosion treatment on the fiber surface before dyeing, and when dyeing yarn or cotton, it is preferable to perform elution and erosion treatment on the cotton, thread, or tow state before dyeing. Erosion treatment is preferable in terms of color matching. However, even if the dyeing is carried out after dyeing, a fine and complex surface unevenness shape will still be obtained, and the surface elution treatment may be appropriately selected at a desired step. Alkali treatment such as caustic soda is an example of elution and erosion treatment for polyester synthetic fibers.
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 dissolution or decomposition rate of fine particles is several times to several tens of times faster than that of polyester, since this will make the unevenness on the fiber surface more fine and complex. In this respect, when 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. The fabric referred to in the present invention is produced under the above conditions, and in particular, the weight loss elution treatment is performed so that the weight loss rate WL (%) of the threads constituting the fabric is relative to the silica content W (%). It is important to process so that WL (%) ≧ 3 + 20 / W ³ is satisfied. This equation is a relationship that shows the constraint conditions when producing the surface condition of the deep black fiber of the present invention. For example, when the silica content is 3% by weight, the weight loss of polyester is 3.7% by weight. Indicates that it is necessary to do the above. If the weight loss treatment is performed to such an extent that the silica content W does not satisfy the above formula, the special spectral reflection ratio S defined in the present invention will not satisfy the prescribed formula, and a deep black fabric will not be obtained. Of course, if the weight loss rate WL (%) of the yarn exceeds 50% by weight, the characteristics of the yarn will be impaired, so the weight loss rate must be 50% by weight or less. The fabric obtained as described above has an optical mirror surface characteristic of conventional polyester fibers, which was caused by the smooth fiber surface due to the irregular random surface of the fibers that make up the fabric. Reflections are reduced. This is because when the incident light incident on the fiber surface is reflected, the reflected light decreases due to repeated scattering and re-scattering that occur one after another around the irregularities, and furthermore, due to the irregularities on the order of wavelength, the reflected light is reduced. This is thought to be because the reflected lights weaken each other. For this reason, the amount of reflection on the fiber surface decreases, resulting in a decrease in brightness. As mentioned earlier, the depth of the color increases as the brightness decreases. In order to investigate the increase in the depth of black color due to a decrease in brightness, it is necessary to determine the color development level due to the decrease in the amount of visible light reflected from the fibers. Although it is possible to evaluate the black color development with the naked eye, it would be more convenient if it could be quantified. The color development of colors other than black is determined by using a color analyzer to measure the ratio r of the amount of reflection of the sample to the amount of reflection of a white plate of magnesium oxide, which provides complete diffuse reflection over the entire wavelength range of visible light wavelengths. It is calculated from the formula = (1-r) ² /2r and is expressed as a value of K/S. However, the value of r for black is extremely small, and even if a difference in shading is made with the naked eye, almost no difference in r value can be detected. This is thought to be because the reflection amount of the magnesium oxide plate itself is too large. Therefore, in order to define the black color development, the present inventors used a black plate with low reflection amount instead of a white magnesium oxide plate, and compared the reflection amount Ro of this control black plate with the reflection amount R of the sample. I learned that the degree of black coloring can be determined with great accuracy by measuring S=R/Ro, which is defined as: Now, this control black plate is called control black, and S is called special spectral reflection ratio. Furthermore, the value of S decreases as the deeper the black becomes. In other words, the smaller the R, the smaller the value of S becomes. I made it black in color. A conventional color analyzer was used as the measuring device. As a control black, 10 g of 3103toner manufactured by Fuji Xerox Co., Ltd. was taken, dispersed in 25 c.c. of hexane, a slide glass was immersed in the solution, the solution was evenly applied, and the hexane was removed by air-drying. The wavelength from 450 mm to 650 mm as used in the present invention is within the wavelength range of visible light, and is a range in which the value of the special spectral reflection ratio S has little variation. When using the special spectral reflection ratio S as above,
As mentioned above, the weight loss rate WL of fabric (fiber)
(%) is WL relative to the contained silica weight W (%)
(%) ≧ 3 + 20 / W ³ By performing the weight loss elution treatment to satisfy A fabric with a deep black color satisfying /S≧0.75+aT√/30929 can be obtained. What the above formula means is that it is well known that twisting the yarn reduces the reflectance, but this formula was devised to define the special spectral reflection ratio S including the twisting effect. In the above formula, T is the number of actual twists or the number of false twists twisted to the basic yarn or group of basic yarns constituting the fabric, expressed in turns/m. Of course, in the case of no twisting, the value is 0. If both real twist and false twist are applied, compare the actual twist number and false twist number x 0.4 and use the larger true twist number. The basic yarn constituting the fabric referred to herein refers to a yarn having a random surface and having the thickest single yarn denier among the yarns constituting the fabric.
Furthermore, when two or more yarns having random surfaces with the same single yarn denier and yarn denier are included, one of the minimum units is called a basic yarn. Dr is the denier of the basic threads that make up the fabric. a is a value that corrects the difference in the degree of influence on the special spectral reflection ratio S between actual twisting and false twisting,
If the number of twists adopted for T is false twist, it should be 0.56,
Set to 1 for actual twisting or non-twisting. for example,
3400 times/36 filament drawn yarn of 75 denier
When false twisting is applied, two yarns are doubled and actual twist is added at 250 times/m, the basic yarn is 75 denier 36
It is a filament, and T is from 34CO×0.4>250
3400, a is 0.56, and Dr is 75. Therefore, 1/S≧1.28, meaning a fabric that satisfies this. The fabrics mentioned here include woven fabrics, knitted fabrics, nonwoven fabrics, and the like. As described above, the fabric of the present invention is typically formed only from fibers having a random surface due to surface elution, but even when other fibers are partially used, the effect can be improved. Ru. A detailed explanation will be given below based on examples. Example 1 During polyester polymerization, colloidal silica having an average particle diameter of 15 millimeters was dispersed and added to ethylene glycol to obtain polymers with silica concentrations of 0, 1, 2, and 3% by weight. The above polymer is spun and stretched to produce 75 denier 36
A drawn filament yarn was prepared, subjected to actual twisting of S twist and Z twist at 2500 T/M, and after heat setting, the warp yarn and weft yarn were used for trial weaving of jersey fabrics. This fabric was embossed and then heat set to obtain fabrics with various weight loss rates using 40 g of an aqueous sodium hydroxide solution, which is a common solvent for silica and polyester, at 97°C. Then Kayalon poly as dye
Black G-SF at 12% owf and Toho as a dispersant
salt TD0.5g/, Ultra MT-N2 as PH adjuster
0.7g/additionally dyed at 135℃,
Reduction washing was performed at 80° C. for 10 minutes using 1 g of hydrosulfate, 1 g of NaOH, and 1 g of nonionic activator. Table 1 shows the relationship between the value of 1/S calculated from the results of measuring the special spectral reflection ratio S of these fabrics and the weight loss rate, and the relationship between the depth of black color as judged by the naked eye for each weight loss rate.

[Table] Even if the weight loss rate is increased when silica is not included,
1/S is 1.22 at most, and there is no depth of color at all. In case of silica content, silica content W (%)
is 1, 2 and 3% by weight, the formula (3+20/
The weight loss rate WL (%) calculated by W ³ ) is 23, 5.5, and 3.7% by weight, respectively, but Table 1 shows that the difference in the effect of weight loss elution treatment before and after the value calculated using the above formula appears. By reducing the amount beyond the value calculated by the above formula, a fabric with deep color can be obtained, and the depth of color is determined by the formula (0.75+aT√/
30929) and is the same value as calculated. That is, in this example, Dr=75, T=2500,
Since a=1, 1/S≧1.45, but even when judged by the naked eye, if 1/S<1.30, there is no depth of black;
When ≦1/S<1.38, the depth of the black color appears slightly,
When 1/S≧1.45, the color is deep black, and when 1/S≧1.63, the color is very deep, similar to wool or triacetate. Example 2 The same drawn yarn as in Example 1 was heated to a heater temperature of 220
℃ and a speed of 90 m/min with a Z twist of 3400 T/M, and a double yarn of S250 T/M was used for the warp and weft yarns to fabricate a prototype Kasidos fabric. After de-sizing and heat-setting this fabric, it was subjected to weight loss treatment and dyeing in the same manner as in Example 1. Table 2 shows the relationship between the weight loss rate of the 1/S value calculated from the results of measuring the special spectral reflection ratio S of these fabrics, and the relationship between the depth of black color determined by the naked eye in each case.

[Table] When silica is not contained, the color does not have depth even if the weight loss rate is increased, and 1/S is at most 1.23. When the silica content is 1, 2, and 3%, the minimum weight loss WL calculated by the formula is 23, 5.5, and 3.7%, respectively. A deep black fabric can be obtained at each content. Moreover, in the case of this example, the basic threads constituting the fabric are 75 denier and 36 filaments, so Dr=75 and T=
3400, a = 0.56, the prescribed formula gives 1/S≧1.27, but even when judged with the naked eye, 1/S≧1.31 shows excellent black depth, and 1/S≧1.45 greatly increases the black depth. It is as black as wool. Example 3 A plain woven fabric was prepared using the drawn yarn having a silica content of 0.3 wt% obtained in Example 1, and after desizing and heat setting, the same weight reduction and dyeing treatments as in Example 1 were performed. Table 3 shows the relationship between the 1/S value calculated from the measurement of the special spectral reflection ratio S of these plain fabrics and the weight loss rate, and the relationship between the depth of black color determined by the naked eye in each case.
Shown below.

[Table] If silica is not contained, the color will not be deep even if the weight loss rate is up to 25%, and 1/S will be 0.70 at most. In addition, when the silica content is 3%, the minimum necessary weight loss rate WL according to the calculation formula is 3.7%, but in this example, the color is already deep with a weight loss rate of 2%.
It can be seen that at a weight reduction rate of 3.7% or more, 1/S is 1/S≧0.75, which is calculated from Dr=75, T=0, and a=1 in this example. In Table 3, when 1/S≧1.05, the depth of the black color increased significantly and became a black color comparable to that of triacetate.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing the mechanism of roughening of the fiber surface by surface elution treatment.

Claims (1)

[Claims] 1. After or before making a polyester fiber containing W weight % of silica into a fabric, the weight reduction rate is determined by using a common solvent for the fibers constituting the fabric and silica.
A fabric made of polyester fibers that has been subjected to a weight loss elution treatment to form fine and irregular irregularities on the fiber surface so that WL (%) satisfies 50≧WL (%)≧3+20/W ³ . When a black dyed fabric detects the reflected light of white light incident at an incident angle of 65° at a reflection angle of 15°, the ratio of the amount of reflection R to the amount of reflection R _p of the black sample as a control. The special spectral reflection ratio S (=R/R _p ) defined as
Over the visible light range from mm to 650 mm 2≧1/S≧0.75+aT√/30929 [where T: number of actual twists or false twists of basic yarns that make up the fabric, times/m Dr: make up the fabric Basic yarn denier a: twist correction value (actual twist, a=1 for untwisted, a=0.56 for false twist)] A polyester fiber with a deep black color that satisfies the following A fabric made of