JPH0796751B2 - Color matching method, masterbatch manufacturing method, and stock solution colored synthetic fiber holder used in these methods - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a color matching method, a masterbatch manufacturing method,
And a stock solution colored synthetic fiber holder used in these methods.

[Conventional technology]

The colored synthetic fibers include those obtained by spinning an uncolored stock solution and then coloring, and those obtained by coloring and spinning the stock solution before spinning. The latter synthetic fibers are referred to as undiluted colored synthetic fibers.

The undiluted colored synthetic fiber is processed and used for products such as mats, carpets, and ropes.

The undiluted colored synthetic fiber is usually colored with a pigment. When the stock solution is colored with the dye, the dye tends to float on the surface of the stock solution and cannot be colored well, whereas the coloring with the pigment does not have such a problem. Moreover, while the color of the fiber colored with the dye is easy to fade, the color of the fiber colored with the pigment is hard to fade.

The stock solution is usually colored with multiple types of pigments provided by the pigment manufacturer. Color swatches are often provided to pigment manufacturers in the form of undiluted synthetic fibers of the desired color. The pigment manufacturer actually prototypes the undiluted colored synthetic fiber by adding a plurality of pigments selected based on the experience up to that time to the undiluted solution according to the color of the color sample. The color of the prototype undiluted colored synthetic fiber and the color of the color sample are visually compared. The trial production of the undiluted colored synthetic fiber and the comparison of both colors are repeated until the two colors match. Then, the pigment maker supplies a pigment masterbatch prepared according to the compounding recipe of each pigment of the undiluted synthetic pigment fiber prototyped so as to match the color of the color sample.

[Problems to be Solved by the Invention]

The method for determining the formulation of each pigment described above requires a skilled technician. Moreover, it takes time to obtain results. The undiluted colored synthetic fiber as a color sample is provided in the cotton state before being processed into products such as mats, but the undiluted colored synthetic fiber in the cotton state must be accurately measured for spectral reflectance with a color measuring device. Is difficult. For that reason, conventionally, it has been necessary to perform the laborious work of actually making a trial production of the undiluted colored synthetic fiber and repeating the comparison with the color of the color sample.

In view of the above circumstances, the present invention, even if not a skilled engineer,
A first object is to provide a color matching method capable of accurately and quickly determining the formulation of each pigment for undiluted solution coloring, and a method for producing a masterbatch containing an accurate concentration of pigment. The second problem is to provide a holder that holds the undiluted solution synthetic fiber during the measurement so that the spectral reflectance of the undiluted solution synthetic fiber can be accurately measured. .

[Means for Solving the Problems]

In order to solve the first problem, the color matching method according to any one of claims 1 to 3, is a stock solution coloring containing a specific single pigment among a plurality of pigments selected to be blended as a sample for pigment data measurement. Synthetic fibers are prepared for each of the pigments, and each of the samples is used in determining the compounding prescription of the color pigment that matches the color of the color sample by using the undiluted solution colored synthetic fibers as these samples and the undiluted solution colored synthetic fibers as the color sample. And individual spectral reflectance of each of the color swatches, each undiluted colored synthetic fibers are densely packed so that the surface to be measured having a constant shape in a state without back-through, and to be measured from the surface to be measured, Based on the spectral reflectance of each sample among these measurement results, using a fixed number method for predicting the coloring state by incorporating only the absorption coefficient of the scattering coefficient and the absorption coefficient of each pigment into the coloring factor, Appropriate combination of pigments Predict the coloring state of the virtual undiluted solution colored synthetic fiber contained in, calculate the spectral reflectance of the virtual undiluted solution colored synthetic fiber from the result, based on this spectral reflectance and the spectral reflectance of the color sample Then, a calculation for comparing the color of the virtual stock solution colored synthetic fiber with the color of the color sample is performed, and when there is no match between the two colors, the calculation processing of the spectral reflectance when the mixing ratio is changed and By repeating the comparison calculation process until it is found that the two colors match each other, the blending prescription of each pigment matching the two colors is obtained.

According to the second aspect of the invention, in addition, a white pigment is included in the undiluted colored synthetic fiber as a sample for pigment data measurement.

According to the invention of claim 3, in addition, when the spectral reflectance is measured, the raw solution colored synthetic fiber is pressed against the back surface of a transparent plate having a flat front and back surface and smooth, so that the back surface of the transparent plate is densely concentrated. The fiber is made to have a flat surface to be measured, and the light for reflectance measurement is applied to the surface to be measured from the transparent plate surface side.

In order to solve the second problem, a method for producing a masterbatch according to claim 4 is a masterbatch according to a compounding recipe of each pigment obtained by the color matching method according to any one of claims 1 to 3. I try to make batches.

In order to solve the third problem, the stock solution synthetic fiber holder for spectral reflectance measurement according to claim 5 is closed at one side with a transparent plate having a smooth front and back surface, and the other side opening. It is composed of a tubular body with a detachable lid body, and the lid body presses the undiluted colored synthetic fibers filled in the tubular body against the transparent plate back surface so that the surface facing the transparent plate back surface is flat. The synthetic fibers are densely packed so that there is no see-through.

[Action]

In the color matching method according to any one of claims 1 to 3, the compounding recipe of each pigment is determined as follows.

(1) First, undiluted colored synthetic fiber as a color sample (hereinafter,
A plurality of pigments to be mixed are selected based on the color of "primed fiber". In this specification, the term "dyed fiber" refers to a fiber that has not yet been processed into a product.

(2) As a sample for measuring pigment data, a dyed fiber containing a specific single pigment of a plurality of selected pigments is prepared for each pigment.

(3) The individual spectral reflectances of each pigment data measurement sample and color sample are measured.

The spun-dyed fibers are densely packed so that the surface to be measured having a constant shape can be seen in a state where there is no back see-through, and accurate spectral reflectance can be measured from the surface to be measured.

(4) Based on the spectral reflectance of each sample, the spectral reflectance of an imaginary primary fiber containing each pigment in an appropriate mixing ratio is calculated.

By using only the absorption coefficient of each pigment as a coloring factor and predicting the coloring state, the coloring state of the virtual original fiber is predicted, and the spectral reflectance of the virtual original fiber is calculated from this prediction result. .

(5) Based on the calculated spectral reflectance and the spectral reflectance of the color sample, a calculation for comparing the color of the virtual original fiber and the color of the color sample is performed.

(6) When the color of the virtual original fiber and the color of the color sample do not match, the mixing ratio of each pigment is changed, and the calculation of the spectral reflectance of the virtual original fiber and the calculation of comparing the two colors are performed. , Repeat until both colors match.

(7) This is a formula for obtaining the blending ratio of each pigment in the virtual primary dyed fiber when the two colors match.

If the white pigment is also included in each sample for measuring pigment data as in the second aspect of the present invention, accurate spectral reflectance corrected for the influence of the white pigment can be obtained from each sample.

According to the third aspect of the present invention, when the spectral reflectance is measured, the original fiber is pressed against the rear surface of the transparent plate whose front and back surfaces are flat, so that the dense original fiber is flat as a measured surface. The surface is stable and can be reproduced with good reproducibility.

According to the invention described in claim 4, a masterbatch having an accurate pigment concentration is produced according to the compounding recipe of each pigment obtained by the color matching method according to any one of claims 1 to 3.

According to the holder of the invention as set forth in claim 5, since the fibrous fibers filled in the tubular body are pressed against the back surface of the transparent plate by the pressing force of the lid behind, during measurement of the spectral reflectance,
It is possible to collect the original fiber so that the flat measured surface without see-through appears on the back surface of the transparent plate.

〔Example〕

Hereinafter, the present invention will be described in detail based on an example thereof.

Examples of pigments selected to be blended include isoindolinone, phthalocyanine blue, carbon black, rouge, titanium yellow, anthraquinone, perylene, perinone, quinacridone, ultramarine, and various azo pigments.

As a high-molecular compound (synthetic resin) that is an undiluted solution, polypropylene, polyester, polyamide, polyethylene,
Examples thereof include polyacrylonitrile.

The dyed fiber as a sample for measuring pigment data is also made of the same type of resin as that used for the color sample.
Of course, the undyed fiber for a sample is in a state before being processed into a product, for example, in a cotton state, like the undyed fiber as a color sample.

Samples with different pigment concentrations are prepared for each pigment. For example, if there are three types of pigment and the pigment concentration is 100
Assuming that there are 4 kinds of 2 parts by weight, 1 part by weight, 0.5 part by weight, and 0.1 part by weight with respect to parts by weight, as a sample for pigment data measurement,
It will make 12 spun-dyed fibers.

In addition to this, as a blank sample that does not include the selected pigments, a single original fiber is prepared in the same manner as other samples except that the pigment is not added.

In addition, white pigments are often included in the priming fiber for matting and the like. When matting is observed in the swatch-dyed fiber, a white pigment at an appropriate concentration (for example, about 0.17 parts by weight) is also included in the sample for measuring all pigment data and the blank sample. Examples of white pigments include titanium oxide (titanium white), zinc white, lead white, and barium sulfate.

White pigments have a considerable effect on the coloring state of other pigments. Therefore, the white pigment is included in each sample in advance to obtain an accurate spectral reflectance including the influence of the white pigment.

The spectral reflectance of each pigment data measurement sample and color sample is measured as follows.

The disperse fibers are densely packed so that a surface to be measured having a constant shape such as a flat surface (flat surface) appears in the state where there is no see-through, and the spectral reflectance is measured from this surface.

When the background is visible through the back side of the plane, an error due to the background color is included, and accurate spectral reflectance cannot be obtained. If there is no see-through, there is no error due to the background color.

The cotton-colored samples and the swatches of the colored fibers are as they are,
The shape of the measured surface is different. Spectral reflectance is related to the shape of the surface to be measured. Since the difference in the shape of the measured surface of each spun fiber causes an error, an accurate formulation of each pigment cannot be obtained. In order to eliminate this error, the measurement surface of each spun fiber is made into a constant shape. For example, the measured surface is flat. Of course, the surface having a constant shape is not limited to a flat surface, and may have another shape. However, a flat surface is preferred. This is because in the case of a flat surface, there is no portion that becomes a shadow of the measurement light, and as will be described below, a transparent plate can be used to easily form a flat surface as the surface to be measured.

In order to make the surface to be measured flat, for example, FIG.
The original fiber holder shown in (b) is used.

This holder comprises a cylindrical body 10 having one side opening closed by a glass plate (transparent plate) 11 and a detachable lid body 12 at the other side opening. The cylindrical body 10 also includes a ring-shaped permanent magnet 13 on the glass plate 11 side. Both front and back surfaces 11a and 11b of the glass plate 11 are smooth and flat surfaces, and both surfaces 11a and 11b are parallel to each other.

The lid 12 can be fixed by screwing the threaded portion on the inner surface of the lid 12 into the threaded portion at the end of the tubular body 10. If the lid 12 is turned in the opposite direction, the cylinder 10
Get out of. The original fiber is filled so as to overflow from the inside of the cylindrical body 10, and the lid body 12 is screwed in. Then, the original fiber 15 is pressed against the glass plate back surface 11b by the lid 12, and the glass plate back surface 1
The surface facing 1b is flat and dense so that there is no see-through. The length of the cylindrical body 10 is about 10 to 40 mm.
The size is such that 15 can be filled with the amount that does not show through.

For accurate spectral reflectance measurement, it is usually preferable that the following conditions are satisfied.

The denier number of the primary fiber is about 3 to 20.

The bulk density (pressed state) is about 0.2 to 0.6 g / cm ³ .

The thickness seen from the measured surface is 5 mm or more, preferably 10 mm
That is all.

In addition, the cotton-dyed undyed fiber may be finely cut into a length of, for example, about 1 to 3 mm and filled in the cylindrical body.

After mounting the undyed fiber on the holder, the spectral reflectance is measured by a spectrophotometer (colorimeter). FIG. 2 shows a system for measuring the spectral reflectance.

The permanent magnet 13 is attracted to the metal case of the spectrophotometer to fix the original fiber holder 1. Light from a light source (for example, a xenon lamp) 21 is transmitted through a metal integrating sphere 22 to the surface 11 of the glass plate.
Irradiation of the primary fiber from a. The reflected light from the original fiber enters the lens 23 → slit 24 → collimator lens 25 → reflective diffraction grating 26, is split by this diffraction grating 26, and further passes through an integrator lens 27 and a light receiving element array 28.
to go into. The reflected light is converted into an electric signal by the light receiving element array 28, and the electric signal is processed by the signal processing circuit 29,
It is sent to and stored in the memory unit 30 of a computer or the like. 31 is a power supply for lighting the light source.

In the light receiving element array 28 of the spectrophotometer, 20 light receiving elements are arranged, and each light receiving element detects the reflected light intensity for each equal wavelength interval of 20 nm, so that the spectral reflectance can be measured.

Among the reflected light, there is the reflected light of the glass plate 11 itself, but this reflected light causes an error, and therefore it is preferable to remove it.
For example, the integrating sphere 22 is provided with a window 22a for removing specular reflection light,
The reflected light of the glass plate 11 itself is guided from the window 22a to the outside of the integrating sphere 22. If the front and back surfaces of the glass plate 11 are not flat and parallel, it becomes difficult to remove the reflected light from the glass plate 11 itself. When the surface to be measured has a constant shape by using a transparent plate, it is preferable that the transparent plate has flat front and back surfaces and is parallel. in this case,
The measured surface becomes a flat surface.

The above holder was used to measure the spectral reflectance of ten undyed fibers produced under the same conditions so that a flat surface appeared, and the average value was set to 100%, and the width of variation was examined. The width of variation was 0.9%, which was very small.

For reference, the width of the dispersion of the spectral reflectance was investigated in the same manner as above except that the filling amount of the original fiber was reduced and the original fiber was not pushed by the lid so that the flat surface did not appear. However, the width of the variation was very large at 7% or more.

The method for providing a uniform-shaped surface on the densely-bonded primary fibers is not limited to the above.

Based on the spectral reflectance obtained from each pigment data measurement sample, calculate the spectral reflectance of an imaginary primary fiber containing each pigment selected to be blended in an appropriate blending ratio as follows. .

First, the mathematical formulas used in the calculation procedure will be described.

The coloring state Km / Sm of the original fiber is represented by the following formula (1). Equation (1) is called the Duncan equation. The scattering coefficient of the pigment of each sample S ₁ ~Si, the absorption coefficient K ₁ ~
Ki, scattering coefficient of uncolored blank sample is Ss, absorption coefficient is
Ks, and the amount of each pigment and synthetic resin is P ₁ , P ₂ ,
…, Pi and Ps.

On the other hand, the relationship between the spectral reflectance R and the coloring state K / S of the object to be colored is represented by the following equation (2) called the Kubelka-Munk equation or the following equation (3). Expression (3) is an inverse conversion expression of Expression (2).

As for the spectral reflectance R of the equations (1) and (2), the spectral reflectance R ′ obtained from the surface to be measured by the spectrophotometer was converted by the following equation (4) called the Sanderson equation. It is a thing. The following expression (5) is an inverse conversion expression of the expression (4).

k ₁ is expressed by the following Fresnel equation. k ₁ = (n-1) ² / (n + 1) ² ; n is the refractive index of the synthetic resin for the primary fiber K ₂ is the ratio of the light that is directed from the inside of the object to the surface and is reflected back by the surface Is.

In the case of the primary fiber, k ₁ is often set to about 0.04 and k ₂ is set to about 0.555.

When the coloring state Km / Sm of the primary fiber is predicted using the equation (1), usually both the scattering coefficient and the absorption coefficient of the pigment must be the coloring factors. This is because the scattering of pigment particles cannot be ignored. At this time, the scattering coefficient and the absorption coefficient of each pigment must be calculated individually. A method of predicting a coloring state using both coefficients as a coloring factor is usually called a two-constant method.

However, in the color matching method of the present invention, the coloring state can be predicted by removing the scattering coefficient of the pigment from the coloring factors.
This is because the scattering coefficient of the densely deposited fiber aggregate itself is significantly larger than the scattering coefficient of the pigment, and a sufficiently accurate prediction result of the coloring state can be obtained even if the influence of the scattering of the pigment on the coloring is ignored. . The large scattering coefficient of the densely packed fiber itself is because when the densely packed fibers are densely packed, light is diffusely reflected on the surfaces of many intricately bonded fibers. In this case, the formula (1) is rewritten as the formula (6) described later.
The method of predicting the coloring state using only the absorption coefficient as the coloring factor is called the constant number method. In the case of predicting the coloring state of the cloth by the dye, the constant number method is still used because the scattering of the dye itself is small. As with dyes, they have found that the coloring state can be predicted using the fixed number method.

However, C ₁ , C ₂ , ..., Ci ,: Pigment concentration Each (Ki / Ss) of the formula (6) is calculated by the following formula (7).
Note that (Ki / Si) and (Ks / Ss) are obtained by applying the spectral reflectance Ri of the pigment data measurement sample i and the spectral reflectance Rs of the blank sample to the equation (2).

(Ki / Ss) = (Ki / Si) − (Ks / Ss) (7) The one-constant method has an advantage that the number of pigment data measurement samples is smaller than that of the two-constant method.

In the case of the two-constant method, 5 to 6 samples are prepared for each pigment in order to separately obtain the absorption coefficient and the scattering coefficient of the pigment. In the case of the constant number method, only one sample is required for each pigment.
Of course, in any case, it is the required number at one pigment concentration.

On the other hand, (Ki / Ss) often changes depending on the pigment concentration. We also made samples for measuring pigment data with different pigment concentrations,
By measuring the relationship between (Ki / Ss) of each pigment and the pigment concentration over a wide concentration range, a more accurate prediction result of the coloring state can be obtained. Specifically, at several concentrations (Ki / Ss)
Is measured, and the intermediate concentration (Ki / Ss) is calculated and used by first-order approximation.

However, in the case of the two-constant method, 5 to 6 samples are required for each concentration, so that the number of samples remarkably increases. In the case of the one-constant method, only one sample is required for each concentration, so the number of samples does not increase so much. Moreover, in the case of the two-constant method, the amount of data significantly increases, and it becomes necessary to increase the capacity of the memory section.

If a white pigment is also added to the sample for measuring pigment data, an accurate spectral reflectance corrected for the influence of the white pigment can be obtained from each sample. The effect of the white pigment is remarkable when the color pigment is a light color such as yellow or the color pigment concentration is low.

It is also possible to separately prepare a sample for measuring pigment data containing only a white pigment, obtain the relationship between the concentration of the white pigment and the absorption coefficient, and use this relationship to correct the spectral reflectances of other pigments by calculation. But this is very difficult. That is, the white pigment does not absorb light and the absorption coefficient is almost 0, and the relationship between the concentration of the white pigment and the absorption coefficient cannot be obtained from the pigment data measuring sample containing only the white pigment. In addition, the degree of influence of the white pigment changes intricately depending on the type of pigment used in combination and the pigment concentration.
This is also because the correction amount cannot be obtained from the pigment data measurement sample containing only the white pigment. Therefore, the method of adding a white pigment to each pigment data measurement sample is effective.

Specifically, the spectral reflectance of the virtual primary fiber is calculated as follows.

(A) Using the formula (4), the spectral reflectances Ri ′ and Rs ′ obtained from the pigment data measurement sample and the blank sample are calculated as follows.
Convert to Ri, Rs.

(B) Applying each spectral reflectance Ri, Rs to the equation (2), each Ki / S
i, Ks / Ss is calculated.

(C) Each Ki / Si and Ks / Ss are applied to the equation (7) to obtain each Ki / Ss.

(D) By applying each Ki / Ss, Ks / Ss, and each appropriately determined pigment concentration C ₁ , C ₂ , ... Ci to the equation (6), the virtual coloring state Km / Sm of the original fiber is obtained. Then, the obtained result is applied to the equation (3) to calculate the spectral reflectance Rm.

Next, based on the spectral reflectance Rm of the virtual original fiber and the spectral reflectance Rn of the color sample, an operation for comparing the color of the virtual original fiber and the color of the color sample is performed. The description will be made assuming that there are three types of pigments.

From the spectral reflectance, the tristimulus values X, Y, Z of the hypothetical fiber and the tristimulus values X ', Y', Z'of the color sample are obtained, and the difference (ΔX, ΔY, ΔZ) between the respective stimulation values is calculated. Then, the color difference ΔE ^* ab (CIE1976L ^* a ^* b ^* color differesce) is calculated, and a calculation is performed to determine whether or not this is a certain value or less. If the difference is equal to or less than a certain value, it is determined that both colors match.

The tristimulus value is calculated by the following equations (8) to (10).

X = KΣR (λ) · x (λ) ρ (λ) Δλ ... (8) Y = KΣR (λ) · y (λ) ρ (λ) Δλ ... (9) Z = KΣR (λ) · z (λ ) Ρ (λ) Δλ ... (10) where x (λ) ρ (λ), y (λ) ρ (λ), z (λ) ρ
(Λ) is a numerical value defined by CIE.

If the color difference is not below a certain value as a result of the calculation, the mixing ratios C ₁ , C ₂ and C ₃ of the respective pigments are changed again, the spectral reflectance Rm of the virtual original fiber is calculated, and the color comparison calculation is Repeat until both colors match.

The new blending ratios C ₁ , C ₂ and C ₃ are obtained as follows.

First, find the following numbers.

_{(∂X / ∂C 1), (} ∂Y / ∂C 1), (∂Y / ∂C 1) (∂X / ∂C 2), (∂Y / ∂C 2), (∂Y / ∂C ₂ ) (∂X / ∂C ₃ ), (∂Y / ∂C ₂ ), (∂Y / ∂C ₃ ), then solves the following three simultaneous equations, and newly uses C ₁ , C ₂ , C Ask for ₃ .

This is a compounding prescription of pigments in which the respective pigment concentrations in the virtual primary fiber that match both colors are obtained.

Needless to say, a computer is used for the prediction of the colored state, the calculation of the predicted spectral reflectance of the virtual primary fiber, and the comparison calculation of both colors.

FIG. 3 shows a basic flow chart of the color matching method of the present invention. The part within the broken line is the part processed by the computer.

The tristimulus value varies depending on the type of illumination light. Normally, the illumination light is changed to sunlight to perform color matching. Alternatively, incandescent lamps or fluorescent lamps may be used as illumination light for color matching. At the same time, the difference between the compounding recipe obtained by using sunlight as the irradiation light and the compounding recipe when the incandescent lamp or the fluorescent lamp is used as the illumination light is also calculated.

In addition, the spectral reflectance Rm of the virtual original fiber is converted into the spectral reflectance Rm ′ by the equation (5) to obtain the spectral reflectance Rm ′ and (4)
It is also possible to perform a calculation for comparing the two colors based on the spectral reflectance Rn ′ of the color sample before conversion by the formula to obtain the blending prescription.

According to the method of the present invention, it takes about one hour (10 hours) to produce results in about three hours,
Moreover, a skilled engineer with about 5 years of experience was required,
Even engineers with 1 to 2 years of experience can obtain sufficiently accurate results.

 Next, the production of the masterbatch will be described.

The masterbatch is a resin in which each pigment is added together with a dispersant according to the determined formulation. The resin for the masterbatch is of the same type as the resin for the priming fiber, but a resin having a characteristic that the pigment is uniformly dispersed is used.
Usually, when a predetermined amount of masterbatch is added to a predetermined amount of uncolored resin, each pigment has a predetermined concentration.
Thus, the masterbatch contains each pigment in a concentration that is several times darker. Of course, the ratio of each pigment complies with the formulation. When a white pigment is added to the pigment data measurement sample, the master batch is also added with an amount of the white pigment according to the addition concentration.

It is not necessary for one masterbatch to contain all types of pigments. The masterbatch may contain only one pigment, and a masterbatch may be made for each pigment.

The masterbatch may be liquid or solid such as pellets.

Hereinafter, a more specific example will be described.

-Example 1-As a color sample, a polypropylene-dyed fiber having a known pigment type and concentration was prepared. The types of pigments used are as shown in Table 1. In Table 1, titanium oxide is a white pigment, and the concentration of each pigment is shown by the amount (g) added to 300 g of polypropylene.

A polypropylene-dyed fiber was prepared for a sample for measuring pigment data and a blank sample.

In the pigment data measurement sample, the amount of each pigment added was 2 parts by weight, 1 part by weight, 0.5 part by weight, and 0.1 part by weight per 100 parts by weight of the resin.
Four kinds of 1 part by weight were prepared and 0.17 part by weight of titanium oxide was added. The denier number of the dyed fiber of the sample and the color sample is 18. The bulk density when measuring the spectral reflectance is 0.22 g / cm ³ , and the thickness is 10 mm.

Using each of the samples and the swatches of the color samples, the compounding recipe was determined by the color matching method exemplified above. The undyed fiber was filled in a holder in a cotton state. The results are shown in Table 1.

-Example 2-As a color sample, polypropylene-dyed fiber with known pigment type and concentration was prepared. The types and concentrations of the pigments used are as shown in Table 1. Except for this, the compounding formulation was determined in the same manner as in Example 1 by the above-described color matching method. The results are shown in Table 1.

-Example 3- As a color sample, polypropylene-dyed fiber having a known pigment type and concentration was prepared. The types and concentrations of pigments used are as shown in Table 1. Except for this, the compounding formulation was determined in the same manner as in Example 1 by the above-described color matching method. The results are shown in Table 1.

-Example 4- As a color sample, polypropylene-dyed fiber with known pigment type and concentration was prepared. The types and concentrations of pigments used are as shown in Table 1. Except for this, the compounding formulation was determined in the same manner as in Example 1 by the above-described color matching method. The results are shown in Table 1.

For comparison, the calculation results obtained by the two-constant method for the cases of Examples 1 to 4 are also shown in Table 1. In this case, the following samples were prepared and used as samples for measuring pigment data.

One containing only 2 parts by weight of white pigment per 100 parts by weight of resin.

2 parts by weight of colored pigment and white pigment in the following ratio to 100 parts by weight of resin.

Colored pigment: White pigment = 60:40 Colored pigment: White pigment = 30:70 Colored pigment: White pigment = 10:90 2 parts by weight of only 100 parts by weight of colored pigment.

As can be seen from Table 1, the prescription obtained by the present invention is in very good agreement with the actual formulation. A prototype of the original fiber was prepared according to this prescription, and the color of the original fiber was compared with that of the sample. A prototype of the original fiber was prepared according to the prescription by the two-constant method, and when the color of the original fiber was compared with that of the sample, a considerable color difference was observed, and it was found that the formulation was not practical.

In addition, the color sample original fiber, the original fiber according to the prescription obtained in Example 1, and the corresponding original fiber having the prescription by the two-parameter method for comparison were heated and pressed to a thickness of 0.4. mm
Each plate was molded, and the light transmittance was measured and found to be 1.0%, 0.7% and 0.1%. I compared the light transmittances to see how much difference the prescription had from the color sample. It can be seen that the formulation obtained by the method of the present invention is close to the actual formulation.

Next, examples in which the white pigment is not used will be described.

-Example 5-A white pigment (titanium oxide) was not added to the color sample and the sample for measuring pigment data, and the pigment composition was as shown in Table 2 and the same as in Example 1 except that The prescription was calculated.

-Example 6-A compound was prepared in the same manner as in Example 1 except that the white pigment (titanium oxide) was not added to the color sample and the sample for measuring pigment data, and the pigment composition was as shown in Table 2. The prescription was calculated.

According to the compounding recipe thus obtained, a primary dyed fiber was produced and visually compared with a color sample, and it was found to be in good agreement.

[Advantages of the Invention] As described above, in the color matching method according to the first to third aspects, an accurate formulation of each pigment can be quickly and easily obtained.

In the method for producing a masterbatch according to claim 4, a masterbatch containing each pigment in an accurate concentration can be obtained.

By using the holder according to the fifth aspect, the accurate spectral reflectance of the original fiber can be easily measured.

[Brief description of drawings]

FIGS. 1 (a) and 1 (b) are views showing an example of a holder according to the invention of claim 5, wherein FIG. 1 (a) is a sectional view and FIG. 1 (b) is an exploded perspective view. FIG. 2 is an explanatory view showing a system for measuring the spectral reflectance of the original fiber.
FIG. 3 is a basic flowchart of the color matching method of the present invention. 1 ... Holder, 10 ... Cylindrical body (cylindrical body) 11 ... Glass plate (transparent plate), 12 ... Lid body 15 ... Original fiber

Claims (5)

[Claims] 1. A stock solution coloring synthetic fiber containing a specific single pigment among a plurality of pigments selected to be blended is prepared for each pigment as a sample for measuring pigment data, and the stock solution coloring is carried out for each of these samples. In determining the blending prescription of each pigment that matches the color of the color sample using the synthetic fiber and the undiluted colored synthetic fiber as the color sample, the individual spectral reflectance of each of the sample and the color sample is calculated as follows. Is densely packed so that the surface to be measured of a constant shape comes out in a state without see-through, and the measurement is performed from the surface to be measured, based on the spectral reflectance of each sample among these measurement results, Using the constant number method that predicts the coloring state by incorporating only the absorption coefficient of the scattering coefficient and the absorption coefficient of each pigment into the coloring factor, a virtual undiluted synthetic fiber containing each pigment in an appropriate blending ratio is used. Predict the coloring state Then, the spectral reflectance of the virtual stock solution colored synthetic fiber is calculated from the result, and the color of the virtual stock solution colored synthetic fiber and the color of the color sample are calculated based on this spectral reflectance and the spectral reflectance of the color sample. When the two colors are not coincident with each other, the spectral reflectance calculation process and the comparison calculation process of both colors when the mixing ratio is changed are repeatedly performed until the two colors agree with each other. , A color matching method that seeks the formulation of each pigment that matches both colors. 2. The color matching method according to claim 1, wherein the undiluted colored synthetic fiber as a sample for measuring pigment data also contains a white pigment. 3. When measuring the spectral reflectance, by pressing the undiluted solution-colored synthetic fibers against the back surface of a transparent plate having a flat front and back surface, the flat measured surface of the undiluted solution-colored synthetic fibers is measured. The surface of the transparent plate is irradiated with light for measuring the reflectance so that the surface to be measured is exposed.
The color matching method described in any of the above. 4. A method for producing a masterbatch, which comprises producing a masterbatch according to the compounding recipe of each pigment obtained by the color matching method according to any one of claims 1 to 3. 5. A jig used in the method according to any one of claims 1 to 4, wherein the opening on one side is closed by a transparent plate having flat and smooth front and back surfaces, and the opening on the other side is formed. It is composed of a tubular body with a detachable lid body, and the lid body presses the undiluted colored synthetic fibers filled in the tubular body against the transparent plate back surface, so that the surface facing the transparent plate back surface is flat. An undiluted synthetic fiber holder for measuring spectral reflectance, in which the synthetic fibers are densely packed so that there is no see-through.