JPH0358054B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is a method for measuring the color difference of dyes. More specifically, it is a method of predicting the color difference of the dyeing result from the liquid color difference of the dye. The color difference of dyes is evaluated based on the color difference of each dyed product obtained by simultaneous dyeing of a standard dye and a sample dye of the same item, with the dyed product of the standard dye as a reference. . In this case, differences in shade appear in the dyed product depending on the purity of both dyes, that is, the ratio of the pigment components contained in each dye. The color characteristics of the dye are determined by correcting the color difference caused by this difference in shading and adjusting it so that the color density is equal. It is evaluated based on the color difference between Furthermore, this color difference can be divided into two types: a so-called hue difference, such as a reddish tendency or a bluish tendency, and a so-called sharpness difference, which relates to the vividness caused by the purity of the color. Normally, when humans evaluate the color of a dye using visual judgment, in addition to the hue difference and sharpness difference mentioned above, we also evaluate the amount of dye used when dyeing to obtain the same color density, that is, the dye density. Currently, the color difference of dyes is evaluated using three values of dyeing power determined from the percentage of the ratio.Preparation of yarn fabric→Preparation of dye solution→Preparation of dyeing bath→Dyeing→Post treatment→Washing→
This is done by comparing a dyed product of a standard dye obtained through drying, a so-called dyeing operation, with a dyed product of a sample dye of the same item. This method requires a great deal of time and effort, and is not accurate enough. Therefore, there is a high demand for an economical, quick, and easy method to accurately evaluate the color difference of dyes. It's summery. Therefore, the present inventors conducted extensive studies using a large amount of experimental data in order to realize this method. As a result, we developed a new method using the absorbance curve of a dye solution. That is, in testing the color characteristics of dyes and measuring the color difference between a sample dye of the same item and a dye as a standard, the present invention uses a solution of the standard dye and a representative sample of the dye of the same item. Prepare each and measure the absorbance curve. Next, using the ratio of the optical densities of the above standard dye and the above representative sample of the same item of dye, the above of the same item of dye is matched to the optical density of the above standard dye. Determine the absorbance curve of a representative sample. Next, the absorption light curve of the dye used as the above standard and the optical density of the dye used as the above standard were matched.
Convert the absorbance curve of the above representative sample of the same item of dye to a transmittance curve, and calculate the tristimulus values X, Y, Z of the above standard dye and the above representative sample of the same item of dye, respectively. Then, it is converted to an isochromatic color system. The chromaticity difference and lightness difference in this color system are determined, and the hue difference component included in this chromaticity difference is defined as the hue difference of the dye solution. The color difference of the dye solution color of the above representative sample of the dye of the same item with respect to the dye of the above standard dye is determined by using the synthetic vector as the difference in sharpness of the dye solution. From the dyeing color difference between the dyes obtained by dyeing using the above standard dye and the above representative sample of the same item of dye, the dyeing color difference between the above standard dye and the above representative sample of the same item of dye, The hue difference and saturation difference or sharpness difference are determined and used as the dye dyeing color difference. (3) Using a statistical method, the dye liquid color difference of
Find the relationship between dye staining color difference. The dye liquid color difference of the sample dye of the same item with respect to the standard dye described above is determined as the hue difference and sharpness difference in the same manner as in the above method. From the dye liquid color difference of the sample dye of the same item with respect to the above standard dye, use the relationship between the dye liquid color difference of and the dye dyeing color difference of . Provided is a dye color difference measuring method characterized by predicting the dye dyeing color difference of the above-mentioned sample dye. This method is based on the fact that the color of the dye solution and the dyeing result correspond exactly. First, using an ordinary spectrophotometer, the absorbance curves in the visible wavelength region are measured for solutions of a standard dye and a sample dye of the same product prepared to a certain solution concentration using an appropriate solvent.
Next, the absorbance curve of the sample dye of the same item is determined by, for example, the ratio of the absorbance in the maximum absorption wavelength band of the standard dye and the sample dye of the same item.
By correcting the absorbance curve of the sample dye of the same item,
Determine the absorbance curve converted to equal optical density. Next, these two curves are converted into a transmittance curve, and the tristimulus values X, Y, and Z of the color are determined using the usual color expression method. From this, various colorimetric calculations are performed to determine the liquid color difference of the dye solution. is calculated, and then the relationship between the liquid color difference and the dyeing color difference, which has been determined by statistical means, is used to predict the color difference when dyeing from this liquid color difference. The above method may seem complicated at first glance, but once a computer program is created, it can be carried out very easily and efficiently, and is more economical and faster than the method using actual staining tests. Moreover, it is a simple and accurate method for predicting the color difference of dyes. According to the present invention, the following excellent effects can be obtained. (1) By omitting various dyeing-related operations, significant test speed-up, process savings, labor savings, and energy savings can be achieved. (2) The current color difference evaluation method for dyed products has poor accuracy, such as differences in dyeing results due to differences in the type and shape of the dyed product, differences in dyeing methods and dyeing machines, and visual judgment that tends to vary between individuals. Although there are many factors that impair the color difference measurement method of the present invention, since these factors are removed, the accuracy is significantly improved. (3) Since the color difference of dyes can be obtained accurately and quickly, it can be widely used for controlling the dye manufacturing process, and has significant economic effects such as reducing the number of defective products and reducing the waiting time for test results during manufacturing. can get. Next, a typical method of the present invention will be explained in more detail. First, solutions of a dye to be used as a standard and a sample dye of the same item are prepared, and an absorbance curve is measured by spectrophotometric analysis. Next, as shown in Figure 1, the optical density of the sample dye solution of the same item is converted to match the optical density of the standard dye solution using the following formula (1), and the difference in color density is calculated. Obtain an absorbance curve that removes color difference components caused by D′ ₂ 〓＝D ₂ 〓×D ₁ λmax／D ₂ λmax (1) Here, D ₁ λmax is the maximum absorbance of standard dye 1, D ₂ λmax is the maximum absorbance of sample dye 2 of the same item, D ' ₂ λ is the absorbance of a sample dye of the same item adjusted to match the optical density of the standard dye. λmax means maximum absorption wavelength. In addition, in order to achieve better consistency with visual color density, the absorbance in the visible wavelength range is weighted to correspond to the human color sense, and the so-called color is integrated over the entire visible wavelength range. There is also a method of adjusting the concentration stimulation values so that they match. Next, an example of this method will be described. The color density stimulus for the three primary color stimulus values is X′,
Y′ and Z″ are calculated using the following formula (2). This is called concentration stimulation, and is determined for the standard dye and the sample dye of the same product.As a simple method for this, X′, Y′,
It is also possible to substitute the maximum value of Z′ for SQ. For dyes that are close to pure colors, this method may give better results. From this, the absorbance D' ₂ λ of the sample dye of the same item, which is adjusted to have the same color density by performing density correction, is calculated using equation (4). D' ₂ λ=D ₂ λ×SQ ₁ /SQ ₂ (4) Here, SQ ₁ is the SQ of the solution of the standard dye at a given concentration determined by equation (3), and SQ ₂ is the SQ of the solution at the same solution concentration. This is the SQ determined from the absorbance curve of a sample dye solution of the same item. Next, calculate the absorbance of the standard dye and the absorbance of the sample dye of the same item after concentration correction.
Using equation (5), it is converted into transmittance as shown in FIG. T ₁ λ=1/Exp(D ₁ λ/0.4343) T ₂ λ=1/Exp(D' ₂ λ/0.4343) (5) Here, T ₁ λ is the transmittance of the standard dye,
T ₂ λ is the concentration-corrected transmittance of the same sample dye, D ₁ λ is the absorbance of the standard dye, D′ ₂ λ
corresponds to the absorbance of the sample dye of the same item after concentration correction. Next, using equation (6), the tristimulus values of the dye solution are determined for the standard dye and the sample dye of the same item. X=K∫PλxλTλdλ Y=K∫PλyλTλdλ Z=K∫PλzλTλdλ (6) K=100／∫Pλλdλ (7) Here, λ, λ, and λ are spectral tristimulus values, and JISZ8728 (2° visual field or 10 These are stipulated in Table 1 of ゜Display method using X, Y, Z system of colors in visual field). Pλ is the spectral distribution of the standard light, Tλ is the transmittance of the standard dye or sample dye of the same item, and λ is the wavelength. Since the X, Y, and Z values obtained here have the same absorbance of λmax, they correspond to the displayed color values when the concentrations of the standard dye and the sample dye of the same item are also the same. Then, it is converted into the color isometric color system, for example, the CIE1976 (L ^* a ^* b ^* ) color system recommended by CIE. L ^* = 1116 (Y/Yo) 1/3 - 16 a ^* = 500 [(X/Xo) 1/3 - (Y/Yo) 1/3] b ^* = 200 [(Y/Yo) 1/3 −(Z/Zo)1/3] (8) Here, in the case of standard light D ₆₅ (10° field of view), Xo=94.811 Yo=100.0 Zo=107.334. Next, from this color system, the liquid color difference between the sample dye of the same item and the standard dye is determined, and the relationship between the hue difference and sharpness difference in this color system is as shown in FIG. In the case of chromatic colors, the brightness difference component included in the sharpness difference is small, so it is possible to use the saturation difference to make the sharpness difference. In Figure 3, P1 is the chromaticity point of the standard dye, P2
is the density-corrected chromaticity point of the sample dye of the same item. P3 is the intersection of the straight line connecting the origin (achromatic color) and P2, that is, the isohue line, and the perpendicular line below P1. Here, the distance between P1 and P3 corresponds to the hue difference component of the color difference, and the distance between P2 and P3 corresponds to the sharpness difference component of the color difference. Note that P2 is the chromaticity point of the sample dye of the same item that has been adjusted to match the color density with respect to the standard dye, so the color difference related to the density difference is zero, so the above 2. The two color differences represent a hue difference and a sharpness difference. Here L ^* is a ^* at the origin (achromatic color)
b ^* The coordinate axis perpendicular to the plane. From this, the color difference can be approximately determined using equation (9). △E=√(△L ^* ) ² +(△a ^* ) ²⁺ (△b ^* ) ² △EBr=√(△L ^* ) ² +△｛(a ^* ) ²⁺ (b ^* ) ² △EH =√(△E) ² −(△EBr) ² (9) Here, △E is the color difference between the two colors, △EH is the hue difference,
△EBr represents the sharpness difference. Next, a method of converting the liquid color difference into a dyeing color difference will be explained. The liquid color difference can be converted into a dye color difference by multiplying it by a specific coefficient. To determine this unique coefficient, first, the liquid color difference is determined using the method described above for a standard dye and a representative sample of the same dye. Also, using the ratio of the absorbance of the same dye at the maximum absorption wavelength of a standard dye (D ₁ λmax) to the absorbance at the maximum absorption wavelength of a representative sample of the same dye (D ₂ Bλmax), or, Using the ratio of the total color density stimulation value (SQ ₁ ) of a standard dye to the total color density stimulation value (SQ ₂ ) of a representative sample of the same dye, adjust the staining density so that equal color density is obtained. Adjust and perform the staining test. next,
The spectral reflectance of these dyed materials is measured, and the tristimulus values X, Y, and Z are determined using equation (10). X=K∫Pλλpλdλ Y=K∫Pλλpλdλ Z=K∫Pλλpλdλ (10) K=100/∫Pλyλdλ (11) Here, λ, λ, and λ are spectral tristimulus values, and JISZ8728 (2° visual field or 10° visual field The method of displaying colors in the X, Y, Z system) is specified in Table 1, etc. Pλ is the standard spectral distribution of light,
Pλ is the spectral reflectance of the dyed material, and λ is the wavelength. Next, it is converted to an isochromatic color system using equation (8), and L ^* a ^*
After determining b ^* , use equation (9) to calculate the hue difference of the dyed product,
Find clarity. The relationship between the liquid color difference and the dyeing color difference determined by the above method is as shown in FIGS. 4-1 and 4-2. The slope of the straight line in Figures 4-1 and 4-2 shows the relationship between the liquid color difference and the dyeing color difference, and the coefficient related to the slope of this straight line is the unique coefficient to be determined. Color differences can be converted to dye differences. For example, according to the examples in Figures 4-1 and 4-2, the liquid color hue difference of 1.0 becomes the dyeing hue difference of 0.075,
A liquid color sharpness difference of 0.5 corresponds to a dyeing sharpness difference of 0.45.
In addition, when calculating the coefficient related to the above gradient,
These relationships can be determined with higher accuracy by performing regression analysis or the like using a statistical method using a large number of samples. Next, a specific implementation method will be explained using examples. In the text, parts represent parts by weight. Example 1 (i) Among the reactive dyes, Color Index No. Reactive Bread 112 was first mixed with a 0.0025% aqueous solution of a standard dye and a sample dye of the same item using an ordinary spectrophotometer to detect visible wavelengths. Measure the absorbance curve of the area (1 and 2 in Figure 5). Next, using equation (1), an absorbance curve is determined in which the optical density of the sample dye of the same item matches the optical density of the standard dye (3 in Figure 5). In FIG. 5, 1 is a standard dye, and 2 is a sample dye of the same item. Next, the absorbance of the standard dye and the concentration-corrected absorbance of the sample dye of the same item are calculated using the formula
Convert to transmittance using (5) (Figure 6). In FIG. 6, 1 is a standard dye, and 2 is a sample dye of the same item. Using these transmittances, calculate the tristimulus values X, Y, and Z for the standard dye and the sample dye of the same item according to equation (6). The tristimulus values X, Y, and Z of the standard dye are: X=78.02 Y=64.02 Z=66.72. Tristimulus values X, Y, Z of sample dyes of the same item
are: X=78.11 Y=64.12 Z=66.68. Then, using Equation (8), an isometric color system, for example, CIE, was recommended. Convert to CIE1976 (L ^* a ^* b ^* ) color system. The L ^* a ^* b ^* of the standard dye is L ^* =84.01 a ^* =37.57 b ^* =1.73. L ^* a ^* b ^* of sample dyes of the same item are L ^* = 84.06 a ^* = 37.54 b ^* = 1.85. Next, from this color system, using equation (9) to find the liquid color difference between the sample dye of the same item and the standard dye, the hue difference is 0.13 and the sharpness difference is 0.06. (ii) On the other hand, add 0.2 parts of the standard dye and 0.14 parts of a representative sample of the same dye in an amount (depending on the representative sample dye used) that will give the same color density as the standard dye. Dissolve in 200 parts of water, add 20 parts of anhydrous mirabilite, add 10 parts of cotton, and raise the temperature to 50°C. Then, after 30 minutes have passed, 4 parts of anhydrous soda carbonate is added and dyeing is carried out at the same temperature for 1 hour. After dyeing, washing with water, soaping,
Dye dyeing difference is obtained by determining the dyeing color difference of a representative sample of the same item of dye with respect to the standard dye of the dyed product obtained by drying as the hue difference and saturation difference or sharpness difference. Next, by the method described in (i), the dye liquid color difference is determined by using the liquid color difference of a representative sample of the same dye with respect to the standard dye as a hue difference and a sharpness difference. Regression analysis is performed using these dye staining color differences and liquid color differences, and the relationship between the dye staining color differences and the liquid color differences is determined as a regression line. (Figure 7) The predicted value of the staining result obtained using a regression line from the liquid color difference of the sample dye of the same item with respect to the standard dye obtained in (i), and the staining of the sample dye obtained by actual staining. The color differences are listed in Table 1.

[Table] Table 2 shows the results of the predicted dyeing values obtained using different sample dyes 1-4 in the same manner as above, in comparison with the actual dyeing results.

[Table] As shown in the above experimental results, the predicted value of the staining result obtained by the above method (staining predicted value) is in very good agreement with the value actually obtained by staining (staining result). Ta. Example 2 (i) Among disperse dyes that are poorly soluble or insoluble in water, in Color Index No. Disperse Blue 301, first, 0.005 part of the standard dye and a sample dye of the same item were mixed with 80 % acetonitrile to make 100 parts, and measure the absorbance curve in the visible wavelength region using a conventional spectrophotometer (1 and 2 in Figure 8). In FIG. 8, 1 is a standard dye, and 2 is a sample dye of the same item. Next, using these absorbances, the color density stimulus values X', Y',
Using Z′ and equation (3), determine the total color density stimulus value SQ. Color density stimulus value X′ of the standard dye,
Y', Z' and total color density stimulus value SQ are X'=63.00 Y'=63.00 Z'=18.9 SQ=144.91. Color density stimulus value of sample dye of the same item
X', Y', Z', and the total color density stimulus value SQ are: X'=62.77 Y'=62.91 Z'=19.77 SQ=145.45. Next, using this SQ value, calculate the absorbance of the sample dye of the same item, which has been adjusted to have the same color density as the standard dye, using equation (4) (3 in Figure 8). Next, the absorbance of the standard dye and the absorbance of the sample dye of the same item after concentration correction are calculated using the formula
Convert to transmittance using (5) (Figure 9). 9th
In the figure, 1 is a standard dye, and 2 is a sample dye of the same item whose concentration has been adjusted. Using these transmittances, calculate the tristimulus values X, Y, and Z for the standard dye and the sample dye of the same item according to equation (6). The tristimulus values X, Y, and Z of the standard dye are: X=26.32, Y=27.55, and Z=72.03. Tristimulus values X, Y, Z of sample dyes of the same item
are: X=26.32 Y=27.57 Z=70.80. Next, using Equation (8), it is converted into a color isometric color system, for example, the CIE1976 (L ^* a ^* b ^* ) color system recommended by CIE. Standard value of dye L ^* a ^* b ^*
are L ^* = 59.5 a ^* = 0.82 b ^* = −44.92. The L ^* a ^* b ^* of the sample dye is L ^* =59.522 a ^* =0.72 b ^* =−43.89. Next, from this color system, using equation (9) to determine the liquid color difference between the sample dye of the same item and the standard dye, the hue difference is 0.08 and the sharpness difference is 1.03. (ii) On the other hand, add 0.2 parts of the standard dye and 0.16 parts of a representative sample of the same item of dye to give the same color density as the standard dye (depending on the representative sample dye used); Water 300 each
Add 10 parts of polyester spun system to the inside of the container and dye for 60 minutes at 130°C under pressure. After dyeing,
The dyeing color difference of a representative sample of the same item of dye with respect to the standard dye for dyeing obtained by hot water washing, reduction washing, hot water washing, and drying is expressed as the hue difference, chroma difference, or sharpness difference. , determine the dye staining color difference. Next, by the method described in (i), the dye liquid color difference is determined by using the liquid color difference of a representative sample of the same dye with respect to the standard dye as a hue difference and a sharpness difference. Regression analysis is performed using these dye staining color differences and liquid color differences, and the relationship between the dye staining color differences and the liquid color differences is determined as a regression line. The relational expression between the liquid color difference and the dyeing color difference obtained by regression analysis from the liquid color difference of the sample dye of the same item with respect to the standard dye obtained in (i) Dyeing hue difference = (liquid color hue difference) × 0.16 Dyeing brightness Table 3 lists the predicted value of the dyeing result obtained using the equation: degree difference = (liquid color sharpness difference) x 0.28, and the dyeing color difference of the sample dye obtained through actual dyeing.

[Table] Table 4 shows the results of the predicted dyeing values determined using different sample dyes 1-4 in the same manner as above, in comparison with the actual dyeing results.

[Table] As shown in the above experimental results, the predicted value of the staining result obtained by the above method (staining predicted value) is in very good agreement with the value actually obtained by staining (staining result). Ta.

[Brief explanation of drawings]

Figures 1, 5, and 8 are absorbance curves of dyes, Figures 2, 6, and 9 are transmittance curves of dyes, and Figure 3 is that of CIE1976L ^* a ^* b ^* color system. chromaticity diagram,
FIG. 4-1, FIG. 4-2, and FIG. 7 show the relational expressions between the liquid color difference and the dyeing color difference.

Claims (1)

[Claims] 1. When testing the color properties of dyes and measuring the color difference between a sample dye of the same item and a standard dye, the standard dye and a representative sample of the same item of dye Prepare each solution and measure the absorbance curve. Next, using the ratio of the optical densities of the above standard dye and the above representative sample of the same item of dye, the above of the same item of dye is matched to the optical density of the above standard dye. Determine the absorbance curve of a representative sample. Next, the absorption light curve of the dye used as the above standard and the optical density of the dye used as the above standard were matched.
Convert the absorbance curve of the above representative sample of the same item of dye to a transmittance curve, and calculate the tristimulus values X, Y, Z of the above standard dye and the above representative sample of the same item of dye, respectively. Then, it is converted to an isochromatic color system. The chromaticity difference and lightness difference in this color system are determined, and the hue difference component included in this chromaticity difference is defined as the hue difference of the dye solution. The color difference of the dye solution color of the above representative sample of the dye of the same item with respect to the above standard dye is calculated by using the composite vector with the sharpness difference as the sharpness difference of the dye solution. From the dyeing color difference between the dyes obtained by dyeing using the above standard dye and the above representative sample of the same item of dye, the dyeing color difference between the above standard dye and the above representative sample of the same item of dye, The hue difference and saturation difference or sharpness difference are determined and used as the dye dyeing color difference. By statistical method, the color difference of dye liquid color and
Find the relationship between dye staining color difference. The dye liquid color difference of the sample dye of the same item with respect to the standard dye described above is determined as the hue difference and sharpness difference in the same manner as in the above method. From the dye liquid color difference of the sample dye of the same item with respect to the above standard dye, use the relationship between the dye liquid color difference of and the dye dyeing color difference of . A method for measuring a dye color difference, comprising predicting a dye dyeing color difference of the above-mentioned sample dye.