JP2003172657A - Colorimetric method for article manufactured by heating, toning method, and toning apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make colorimetric work, toning work, and the manufacturing of articles efficient by speedily obtaining the results of colorimetry on the articles manufactured by heating with practically sufficient accuracy. <P>SOLUTION: This colorimetric method for measuring the color of an article (s) manufactured by processes including a heating treatment and measuring the color of the article manufactured by heating includes both a process (a) for performing colorimetry on the article to be measured (s) such as an injection molded article in a temperature-raised state as if extracted from injection molding molds 12 and 14 after manufacturing by a colorimetric apparatus 20 to obtain a color value in the temperature-raised state and a process (b) for correcting the color value in the temperature-raised state into a color value in a temperature-lowered state on the basis of the previously obtained correlation between temperatures and colors of the article through the use of an information processing device such as a computer 40. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color measuring method, a color adjusting method, and a color adjusting apparatus for heat-produced articles. More specifically, heat treatment is performed in the production process such as an injection molded article, and immediately after production. Is a temperature-increased heated article, using a color measurement method for measuring color, and using such a color measurement method,
The present invention is directed to a toning method for adjusting the color of an article by blending materials during manufacturing and a toning device used in such a toning method.

[0002]

2. Description of the Related Art Various industrial products are colored in various colors. To color various items to the desired color,
A coloring material such as a pigment is mixed with a raw material for manufacturing an article, or a coating film containing the coloring material is coated separately from the body of the article. However, the color of the actually manufactured article may be different from the intended color even if a material or coating material that has been toned in advance is used. Therefore, the article is manufactured on a trial basis, the color of the manufactured article is measured, and if the difference from the target color is large, change the material composition of the article or the composition of the coating material, and repeat the test production. Is being carried out.

Further, in the production line, the colors of articles continuously manufactured are measured, and when the difference from the target color becomes large, the material composition is changed and the manufacturing conditions are adjusted as described above. To be done. In particular, in the field of resin molding, a combination of a plurality of preliminarily toned resin materials is used for product molding. The color of the molded product can be easily adjusted by changing the composition of the toning resin material. In this case, of course, not only in mixing the materials for product molding and toning, but also in the production of toning resin material prepared in advance, the toning resin material is experimentally molded, the test piece is measured, and the color measurement is performed. Based on the result, the blending of the toning resin material is adjusted.

In the manufacturing process of industrial products, a process involving heating is often carried out, such as heat molding of raw materials, heat processing of articles, and heat curing of coating films. An article manufactured through such a heat treatment can be obtained at a temperature rise considerably higher than the temperature at which the article is actually used (usually room temperature). In the conventional colorimetric method or colorimetric device, it is common to measure the color of the article after the temperature of the article is sufficiently lowered to the room temperature which is the operating temperature. The reason is that the color of the article is often greatly different between the temperature rising state and the temperature lowering state, and if the color of the article is adjusted based on the result of color measurement in the temperature rising state, the color greatly differs from the target color in the used state. This is because it becomes a colored article.

[0005]

In the above-described conventional color measurement technique, since the color measurement cannot be performed until the temperature of the article is sufficiently lowered after the article is manufactured at the elevated temperature, it is necessary to obtain the color measurement result. There was a problem that it took a long time. In the color matching work described above, if the difference between the color of the manufactured article and the target color is large, it is necessary to immediately change the material composition, etc.,
If it takes a long time to obtain the result of color measurement, it is impossible to change the material composition during that time. In normal color matching work, it is usual to repeat material blending, product manufacturing and color measurement many times to get closer to the target color, so if the color measurement work takes a long time, The efficiency will be greatly reduced.

Further, in a production line in which articles are continuously manufactured, when color measurement is performed in order to control the color of the product, the production is continued during the color measurement work. Even if the production line is stopped or modified when a defect is found as a result of, the large amount of products produced up to that point must be discarded, which is extremely uneconomical. An object of the present invention is to solve the above-mentioned problems of the prior art, to quickly obtain colorimetric results of various articles with practically sufficient accuracy, and to perform colorimetric work and toning work and eventually article manufacture. It is to improve efficiency.

[0007]

A colorimetric method for heating manufactured articles according to the present invention is a method for measuring the color of an article manufactured through a step including heat treatment, in which the temperature is still raised after the manufacturing. (A) to obtain the color value in the temperature rising state by measuring the color of the target article in the state, and the temperature of the article obtained in advance −
And (b) correcting the color value in the temperature rising state to the color value in the temperature falling state based on the color correlation. [Heating-produced articles]
An ordinary industrial product or test product can be applied as long as it is an article manufactured through a process including heat treatment.

Specifically, various resin molded products can be mentioned. Examples of resin molding accompanied by heat treatment include injection molding, extrusion molding, cast molding, and inflation molding. The articles obtained by resin molding include not only those having a three-dimensional shape but also plate-like ones and film-like ones. Cast and forged products such as metals and ceramics and hot-worked products are also included. The article once manufactured may be heat-treated in a heating furnace or the like to change the surface texture. In some cases, a coating or coating is applied to the surface of the article and then heat treatment is performed to form a colored cured film.

The articles include not only those sold or used as industrial products but also test products and inspection products. For example, a toning sample plate used for toning work, an inspection piece used for quality control, and the like can be mentioned. In any case, it is applied to the purpose of measuring the color of an article in a temperature rising state at the stage where a process in which the color may change is completed before the manufacturing is completed. [Raised Temperature State] The specific temperature condition is not particularly limited as long as it is a temperature higher than the temperature assumed as the final use temperature of the article and a temperature that causes a color difference from the use temperature.

The operating temperature of general industrial products is often room temperature. 20 to 30 under average environmental conditions in Japan
C is considered to be room temperature. The temperature rising state is a temperature that is higher by 10 ° C. or several tens of ° C. than the normal temperature. In addition,
If the article is a special article whose operating temperature is below zero, it may be considered to be in a temperature-increasing state even at the normal temperature. The upper limit of the temperature in the temperature rising state is a temperature at which color measurement can be practically performed. The measurable temperature of a general colorimeter varies depending on the measurement method and internal structure, but normally the article temperature is 10 to 80 ° C.
It is possible to measure in the range. The ambient temperature of the measurement environment for operating the colorimeter can be in the range of 0 to 40 ° C.

When the temperature of the article immediately after manufacture exceeds such a limit temperature for color measurement, it is effective to measure the color after forced cooling or cooling. Even in this case, since it is not necessary to measure the color after the article is completely cooled to room temperature, the cooling time or the waiting time before starting the color measurement can be short. [Cooling state] The cooling state is a temperature at which the article is used or the color of the article is evaluated. Normal industrial products correspond to the above-mentioned normal temperature, but depending on the article, the temperature may be lower or higher than normal temperature. As the temperature range of the temperature falling state, 10 to 30 ° C can be adopted. The temperature difference between the temperature rising state and the temperature lowering state is effective in the range of 10 to 70 ° C. When the temperature difference between the temperature rising state and the temperature lowering state is small, there is no problem even if the color of the temperature rising state is directly evaluated as the color of the temperature lowering state. If the temperature difference is too large, the error between the color in the temperature-decreasing state predicted from the color in the temperature-elevating state and the actual color increases.

[Color Measurement] An ordinary color measurement device and a normal color measurement method can be adopted according to the characteristics of the article. Specifically, a spectrophotometer can be used. It is preferable that the colorimetric result is output as an electric signal. The color measurement may be performed in contact with the surface of the article, or the color measurement may be performed in a non-contact manner with a space provided between the article and the article. The non-contact colorimeter does not have a risk of damaging the article and is less likely to be adversely affected by heat transfer from the article in a temperature rising state. The color measurement result is usually obtained as a numerical value that specifies a color, that is, a color value. There are various methods for expressing numerical values of colors, and any method may be adopted. There is a method of expressing a color by a point position in space coordinates, and a space in which such a color is arranged is called a color space.
As the color space, the L ^* a ^* b ^* color space is known. L ^* ,
Coordinate positions are indicated corresponding to coordinate axes in three directions in which a ^* and b ^* are orthogonal. As the color value indicating the coordinate position, C ^* indicating the distance from the origin or the coordinate axis or H ^* indicating the phase angle from the coordinate axis can be used. L ^* u ^* v ^* color space or x ^* y ^*
You can also use the z ^* color space.

[Temperature-Color Correlation] This is the correlation between the temperature of the article and the color measured at that temperature. It may be a correlation between two colors that are specific temperatures in the temperature rising state and the temperature falling state, or may be intermittent or continuous in a certain temperature range including the target temperature rising state and the temperature falling state. It may be a correlation between temperature and color. The temperature-color correlation may be a simple linear proportional relationship or a relationship represented by a higher-order function such as a quadratic function.
The higher-order function can be approximated to a lower-order function in consideration of practicality.

As described above, when a color is specified by combining a plurality of color values, each color value has an independent correlation, or a plurality of color values are correlated with each other. May have. The temperature-color correlation can be represented by the correlation of coordinate positions in the color space. For example, the color values of L ^* , a ^* , and b ^{* in} the L ^* a ^* b ^* color space can be represented by the correlation between the color value in the temperature rising state and the color value in the temperature falling state. [Color Value Correction Formula] A formula or a group of formulas for correcting the color value in the temperature rising state to the color value in the temperature decreasing state based on the temperature-color correlation of the article obtained in advance.

Generally, the functional expression F is such that the color value in the temperature falling state = F (the color value in the temperature rising state). By substituting the color value in the temperature rising state into the functional expression F, the color value in the temperature falling state can be obtained. When specifying a color with a plurality of color values, a correction formula common to all color values may be used, or a correction formula different for each color value may be used. [Reference article] In order to obtain the temperature-color correlation, a reference article is prepared in advance, colorimetry is performed at different temperatures, the temperature-color correlation is determined, and color value correction is performed based on the result. You can get the formula.

[0016] The reference article may be an article having exactly the same material and shape structure as the target article, or a test article having a simpler shape structure that exhibits the same characteristics as the target article in terms of color is used. You can also Usually, a simple rectangular plate-shaped or disc-shaped test piece is used. If the color of the reference article is the same as or close to the color of the target article, it can be estimated that the temperature-color correlation is also the same or close to each other, so that the color measurement of the target article can be easily and accurately performed. However, even if a plurality of reference articles having a color different from the color of the target article are combined, the color measurement can be performed with sufficient accuracy.

If the colors of the reference article prepared in advance, that is, the reference colors, which have coordinate positions uniformly arranged in the color space, are combined, accurate measurement can be performed even for the target article having an arbitrary color. Color is possible. For example, if four types of colors of red, yellow, green, and blue are used as the reference colors, the accuracy of color measurement can be sufficiently ensured for almost all colors. It is also possible to adopt a plurality of reference colors in the same system as the color of the target article. The temperature-color correlation is obtained based on the color data in different temperature states obtained for each reference article. A temperature-color correlation is obtained for each color of the reference article, that is, for each reference color.

[Color Prediction of Target Article] By using a color value correction formula based on the temperature-color correlation, the color of the target article is corrected to the color value of the temperature drop state by correcting the color of the target article in the cool state. Ask. The color value of the target article in the temperature rising state may be measured by the color measurement method described above. The temperature-color correlation of the reference article, that is, the reference color, and the color value correction formula are obtained in advance. By applying the color of the target article in the temperature rising state to the temperature-color correlation of the reference color or the color value correction formula, the color value of the target article in the temperature falling state can be predicted. It is estimated that the color value correction formula of the reference color that has the same color as the target item in the temperature rising state is used, and the color of the reference color corrected by the color value correction formula in the temperature decreasing state is the color of the target item in the temperature decreasing state. can do. It is also possible to approximate the temperature of the target article in the temperature-decreasing state to the color of the reference color in the temperature-decreasing state from the temperature-color correlation or the color value correction formula of the reference color whose color in the temperature-raising state approximates that of the target article. it can.

From the temperature-color value correlation of a plurality of reference colors,
An accurate color value can be obtained by predicting the color value of the target article in the lowered temperature state. If the reference colors located on both sides of the coordinate position of the heated state of the target article in the color space are used as the plurality of reference colors, the color of the target article can be accurately predicted. The coordinate position in the color space is usually represented by coordinate axes in three directions in which three types of color values are orthogonal. A color value in which the influence of temperature can be ignored can be excluded from the evaluation of the coordinate position in the color space. For example, in the case of the color space L ^* a ^* b ^* , it is possible to ignore the L ^* axis and evaluate only by the coordinate position on the plane formed by the a ^* axis and the b ^* axis.

Assuming that the relative coordinate position relationship between the plurality of reference colors and the color of the target article in the color space does not change between the temperature rising state and the temperature lowering state, the coordinates of the plurality of reference colors in the temperature lowering state. From the position, the coordinate position or color of the target article can be predicted. Specifically, the color value correction formulas for a plurality of reference colors can be obtained by interpolation correction based on the relative positional relationship between each reference color and the target article. . The hue angle H in the L ^* a ^* b ^* color space can be used as the color value expressing the reference color and the color of the target article in the color space. A plurality of reference colors can be selected so that the hue angle H of the color of the target article in the temperature rise state is an intermediate value of the hue angles H of the colors of the plurality of reference colors in the temperature rise state.

[Toning Method] By using the toning method of the present invention, it is possible to perform the toning of the article produced by heating. Toning means matching the color of the manufactured article to a predetermined target color. In the first stage of the color matching work, the color of the material of the article is roughly adjusted to the target color based on past data and theoretical predictions. The color of the article depends on the formulation of the materials used. The color of the article can be changed by the combination and ratio of coloring components such as pigments and dyes in the compounding material.

The material thus prepared is used to produce an article through the steps including the above-mentioned heat treatment. The manufactured article is color-measured by the above-described color-measuring method of the present invention while the temperature is raised. Based on the result, the color of the temperature falling state is predicted. The obtained color of the article is compared with the target color.
Usually, the difference between various color values is evaluated. If the difference in color value from the target color is within the allowable range, the toning is completed. It can be seen that if the same material composition or manufacturing conditions as this article are adopted, an article of the target color can be produced.

If the obtained color of the article is largely different from the target color, the color of the material of the article is readjusted. It is possible to determine a pigment to be increased / decreased or added / removed when readjusting, depending on which color value among the plurality of color values has a large deviation. Using the re-adjusted material, the same manufacturing process, color measurement process in the temperature rising state, re-conditioning process of the article material, until the difference between the color of the article and the target color is within the allowable range,
repeat. [Color Matching Device] As long as a color measuring device that executes the color measuring method of the present invention is incorporated, the other device structure is not particularly limited, and the same technique as a normal color matching device can be applied.

It is preferable that the color measuring device is incorporated in the article manufacturing facility or installed near the manufacturing facility so that the temperature of the target article in the temperature rising state can be measured.
It is preferable that the color measuring device, particularly the color measuring unit or the color meter, has a structure that is not easily affected by heat generation, vibration, and the like of the article in the temperature rising state or the manufacturing apparatus. The article can be taken out of the manufacturing apparatus and moved to another place for color measurement. It is also possible to measure the color of the article placed in the manufacturing apparatus. It is also possible to perform color measurement on the way of a conveyor or the like that conveys articles installed inside or outside the manufacturing facility.

An article can be taken out of the manufacturing apparatus by a robot arm or the like and transferred to the color measuring apparatus, or can be arranged in the color measuring section of the color measuring apparatus. The evaluation of the color measurement result can be performed using an information processing device such as a computer. The information input to the information processing device includes the colorimetric information obtained by the colorimetric device, the information of the target color, and the information about the material combination of the article. The arithmetic unit of the information processing apparatus can compare the colorimetric information with the target color information and correct the material combination so that the color of the article to be manufactured next approaches the target color. Information or database regarding the temperature-color value correlation for each of the plurality of reference colors described above is stored in advance in the information processing device, and from the color measurement information in the temperature-increased state of the target article,
It is possible to calculate color information in the temperature falling state.

The information processing device outputs the corrected material combination information. For output, ordinary output means such as display on a display device, printing on a printer, and lighting of a display lamp is adopted. On the surface of the color-measured article,
Means such as engraving, printing, labeling, etc., and colorimetric information can also be recorded. The color measurement information can be transmitted from the color measurement device to the information processing device by using an information communication unit such as a communication cable or a wireless device. [Toning part] A means or device for adjusting the material composition of the article, that is, the toning part can be incorporated in the toning device based on the output from the information processing device.

The toning section accommodates materials of a plurality of colors,
Materials of required colors are selected and weighed, and materials of plural colors are mixed to obtain a compounded material having a predetermined toning. These compounding operations are performed based on a command from the information processing device. The material toned and blended in the material toning unit is conveyed to a manufacturing apparatus such as a molding machine and used for manufacturing an article.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Toning Device] The toning device shown in FIGS. 1 to 3 measures the color of an injection molding device 10 for molding a toning sample plate s as an injection-molded product and a toning sample plate s. Color measuring device 2
0 and the toned sample plate s from the injection molding device 10 to the color measurement device 2
A transfer device 30 for transferring to 0, and a computer 40 for controlling processing of colorimetric information and operation of each device 10, 20, 30
It has and. <Toning Sample Plate> The toning sample plate s is a rectangular plate-shaped injection molded product used in the toning operation to evaluate the compounding of the molding material and the color appearing in the injection molded product.

<Injection Molding Device> The injection molding device 10 has the same structure and function as the device structure used in a normal injection molding technique. However, it may have a small size or a simple structure as compared with an apparatus used in a production line of injection molded products. The injection molding device 10 includes a pair of molding dies 1.
2 and 14 and a resin supply unit 50. <Molding Mold> As shown in FIGS. 2 and 3, one molding mold 12 is a fixed mold and the other molding mold 14 is a movable mold. The movable mold 14 is formed with a cavity 15 corresponding to the outer shape of the toning sample plate s. In the fixed mold 12,
A resin filling passage 13 to which the resin is supplied from the resin supply unit 40 is provided, and the resin is supplied to the cavity 15 of the movable molding die 14 in the mold closed state.

<Resin Supply Section> The resin supply section 50 arranged on the back surface of the fixed mold 12 has a resin passage 52 in the center of the cylinder body 51, and the resin passage 52 can rotate and move forward and backward freely. A screw 54 is arranged. The tip of the resin passage 52 is connected to the resin filling passage 13 of the fixed mold 12. Behind the resin passage 52, a hopper 56
Are connected. The hopper 56 is supplied with the toning compound 60 from the toning unit 60. The molding material P such as pellets charged in the hopper 56 is heated in the resin passage 52 and is sent forward while being kneaded by the rotation of the screw 54. The molding material is plasticized by the heat kneading, and the resin R in a plastic state or a liquid state is obtained.

When the screw 54 is advanced, a high pressure is applied to the resin R in the resin passage 52, and the resin R is pumped and filled from the resin filling passage 13 of the fixed molding die 12 into the cavity 15 of the movable molding die 14. When the movable molding die 14 is opened after the resin R filled in the cavity 15 is cured,
The molded toning sample plate s can be taken out from the cavity 15. The operations of the injection molding apparatus 10 and the molding dies 12 and 14 described above can be controlled by the computer 40 capable of transmitting information via the information line 42. <Color Measuring Device> The color measuring device 20 is arranged near the injection molding device 10. The colorimetric device 20 has a colorimetric unit 22 incorporating a colorimeter capable of measuring the surface color of the toning sample plate s in a non-contact manner.

The colorimetric device 20 comprises a movable base 2 which is horizontally movable.
4 and moves in the direction of approaching and separating from the toning sample plate s. The colorimetric device 20 is connected to the computer 40 by an information line 42, and can send colorimetric information to the computer 40 and control the operation of the colorimetric device 20 with the computer 40. <Transfer device> The injection molding device 10 includes a transfer device 30 for the molded toned sample plate s. The transfer device 30 has a horizontal arm 34 that linearly moves in the mold opening direction with respect to a support 32 to the injection molding device 10, and a movable molding mold 14 that linearly moves in the vertical direction with respect to the horizontal arm 34 to open the mold. A vertical arm 36 that moves from between the fixed mold 12 and the fixed molding die 12 to the position of the color measurement device 20, and a grip portion 38 that is provided at the tip of the vertical arm 36 and that holds the toned sample plate s. The grip 38 is rotatable front and back.

The transfer device 30, the resin supply unit 50, and the moving base 24 of the colorimetric device 20 are connected by an information line 42 and operate in conjunction with each other. <Computer> As the computer 40, an ordinary personal computer can be used. Necessary instructions can be input from the keyboard 41. As described above, the computer 40 is connected to the injection molding apparatus 10 including the movable molding die 14 and the resin supply unit 50, the colorimetric device 20, the operating mechanism of the transfer device 30, and the like by the information line 42, and is connected to each other. The necessary information can be exchanged between them.

The computer 40 may only transmit the colorimetric information between the colorimetric device 20 and the colorimetric unit 60, and may also operate the injection molding device 10 and the transfer device 30. It may be monitored or controlled physically. <Toning part> The toning part 60 stores the molding materials P of a plurality of colors. Based on a command from the computer 40, the necessary color materials are mixed in a required ratio to form a toning material. Make P. [Color measurement work] The color measurement work will be sequentially described with reference to FIGS.

<Preparation of Molding Material> As shown in FIG. 1, a pellet P of molding material is put into the hopper 56 of the resin supply section 50. The pellets P are made of a coloring material or a combination thereof that is expected to be suitable for obtaining an injection-molded product exhibiting a desired color, and are preliminarily toned and blended in the toning unit 60. Normally, from a color sample book prepared in advance or multiple types of masterbatch materials and their colorimetric data,
A computer or the like is used to predict an appropriate composition and determine a molding material to be supplied accordingly. For this work, a so-called color matching method is adopted.

The pellets P charged into the hopper 56 are melted and kneaded while moving in the resin passage 52 to become molten resin R. <Injection molding> When the screw 54 is advanced in the resin passage 52 of the resin supply unit 50, a high pressure is applied to the resin R on the tip side of the resin passage 52, and the resin filling passage 1 of the fixed molding die 12 is applied.
The resin R is pressure-filled into the cavity 15 of the movable mold 14 through the step 3. <Mold Opening> As shown in FIG. 2, when the resin R in the cavity 15 is cured, the toned sample plate s is molded. The movable mold 12 is opened.

Horizontal arm 34 and vertical arm 3 of transfer device 30
6 is operated, the grip portion 38 is arranged on the front surface of the movable molding die 12 that has been opened, and the toning sample plate s protruding from the movable molding die 12 is gripped by the grip portion 38. The toning sample plate s is
It has just hardened and is still warm. <Color measurement work> As shown in FIG. 3, the grip portion 38 of the transfer device 30 is inverted to turn over the posture of the toned sample plate s. The toning sample plate s is arranged in front of the color measurement unit 22 of the color measurement device 20. The colorimetric unit 22 of the colorimetric device 20 that has moved on the moving table 24 approaches the surface of the toned sample plate s, and measures the surface color of the toned sample plate s.

At this time, the toned sample plate s is still in a temperature rising state, for example, about 50.degree. The color measurement information obtained by the color measurement device 20 is sent to the computer 40. <Color Prediction of Toned Sample Plate> Based on the colorimetric information in the temperature-increased state of the toned sample plate s sent to the computer 40, and the database information about the temperature-color correlation stored in the computer 40. First, a calculation for predicting the color of the toned sample plate s in the lowered temperature state is performed. Details of the prediction calculation will be described later. As a result of the calculation, the color of the temperature-falling state of the toned sample plate s which is still in the temperature-rising state can be known.

On the screen of the computer 40, it is possible to display information such as the color of the temperature falling state, the color of the temperature rising state, and the color difference between the two. The color measurement result can also be used for color matching work. [Color matching method] The color matching of the injection-molded product is performed using the above-described color measurement method. First, the above-described colorimetric work is performed using a molding material having a predesigned composition. In order to obtain accurate and stable colorimetric results, injection molding and colorimetry are performed multiple times using the same molding material, the colorimetric information obtained is comprehensively judged, and injection molding is performed using that molding material. It is preferable to evaluate the color of the product.

If the result of the color measurement is different from the target color, the composition of the molding material is corrected. Usually, the color difference between the target color and the colorimetric result is quantified, and the quantified color information of the molding material whose color information is known in advance is combined to newly add or reduce the molding material. Find the combination combination of. Such a toning process is a technique known as a normal toning process using a computer, that is, computer color matching. When the corrected composition of the molding material is determined, the molding material P, which has been subjected to the color-mixing by the color-matching section 60, is put into the hopper 56 of the resin supply section 50 according to the decided mix-up, and the injection molding and the color measurement work are performed again. To do.

Such an operation is repeated until the difference between the color measurement result of the toning sample plate s and the target color falls within the allowable value. Once the proper molding compound formulation is obtained, the toning operation is complete. [Automatic Color Matching System] FIG. 4 illustrates an automatic color matching system using the color matching method and apparatus described above. (1) Weigh and mix raw materials. If a raw material tank or hopper that separately stores a plurality of resin raw materials having different colors, a weighing instrument, a stirring mixer, and the like are combined, and the operations of these devices are controlled by the computer 40, the computer 4
A molding material can be prepared by combining the raw materials according to the instruction No. 0 in a predetermined composition.

(2) Color matching section 6 equipped with a metering and mixing device
0 and the hopper 56 of the resin supply unit 50 described above are connected to each other by a powdery or granular material conveying means such as an air transportation pipe or a belt conveyor, so that the molding material can be automatically charged. (3) The steps from injection molding to the color measurement of the molded humidity control sample plate s and the removal of the humidity control sample plate s after the molding material P is charged into the hopper 56 have been described in the above embodiment. As described above, the automatic work is performed according to the instruction from the computer 40. (4) In the computer 40 to which the colorimetric information has been input, a pass / fail judgment is made. If the target color has been obtained, it is OK and the toning operation is completed.

(5) If the difference from the target color is large, the color is unacceptable (NG), and after the correction calculation of the composition is performed, the above-described work is repeated from the raw material measurement based on the corrected composition. In such an automatic color-matching system, once the target color is determined, all the subsequent color-matching operations can be performed automatically to complete the color-matching operation. Since no manual labor or adjustment operation is required by the operator, it is possible to advance the color matching work at midnight or on holidays when there is no operator. It is also possible for one worker to simultaneously perform multiple toning operations. Since individual differences and variations in measurement are eliminated depending on the degree of skill of the operator, it is possible to stably obtain a toning result with the required accuracy.

[Reference Color Temperature-Color Correlation] A procedure for obtaining the reference color temperature-color correlation used in the calculation by the computer 40 will be described. As a standard color, red,
A large number of reference articles (toning sample plates s) belonging to four groups of yellow, green, and blue are manufactured. The color of each reference article is measured in a temperature rising state (T ₁ = 50 ° C.). Colorimetric data (T ₁ = 50 ° C.): [L ^* ₁ , a ^* ₁ , b ^* ₁ ,
H ₁ , C ₁ ] The same reference article is subjected to color measurement even in a cooled temperature-down state (T ₀ = 30 ° C.).

Colorimetric data (T ₀ = 30 ° C.): [L ^* ₀ , a ^{*
_{0, b * 0, H 0}} , C 0 ] At this time, the reference article of the same color and color measurement plurality increments, by obtaining an average value of each color value, accurate data can be obtained. In the group of each color system such as red, the correlation between the colorimetric data in the temperature rising state and the colorimetric data in the temperature falling state is expressed by the following color value correlation formula, and the coefficient of each dimension term is calculated by the least squares method. Apply to obtain. If it is a two-dimensional functional expression such as the following expression, the color value correlation expression can be obtained with sufficient accuracy for practical use. Color value correlation ^{_{equation: L * 0 = α L (}} L * 1) 2 + β L (L * 1) + γ L a * 0 = α a (a * 1) 2 + β a (a * 1) + γ a b * 0 = Α _b (b ^* ₁ ) ² + β _b (b ^* ₁ ) + γ _b color correction coefficient [α _L , β _L , γ _L , α _a , β _a , γ _a , α _b ,
β _b , γ _b ] is the temperature rise state of the reference color in each color system (5
0 ° C) [L ^* ₁ , a ^* ₁ , b ^* ₁ ] and temperature drop state (30 ° C) [L
^[* ₀ , a ^* ₀ , b ^* ₀ ] and the reference data represent the temperature-color correlation.

Such reference data is obtained for each reference color or each color system, collected in a database, and recorded or stored in a computer. After the result of color measurement is obtained for the target object for color measurement in the temperature rising state and the temperature lowering state, the color measurement result can be used as one of the accumulated data in the database. By doing so, as the number of colorimetric examples of the target article increases, the content of the database is enhanced and accurate prediction becomes possible. [Color Prediction of Temperature Decreasing State of Toned Sample Plate] The target article is subjected to color measurement in a temperature increasing state (T ₁ = 50 ° C.).

Colorimetric data (T ₁ = 50 ° C.): [L ^* _1T , a
^{_{* 1T, b * 1T, H}} 1T, C 1T ] In the color plane a ^* b ^* shown in FIG. 5 (T _1), the color coordinates X ₁ of the target article, the phase angle H _1T clockwise from the a ^* axis Have From the database, reference color data whose phase angle H _1A is smaller than the phase angle H _1T of the color coordinate X _{1 and} whose color coordinate A ₁ is as close as possible is selected. The illustrated color coordinate A ₁ represents the red reference color A. Color correction coefficient of reference color A: [α _LA , β _LA , γ _LA , α _aA , β _aA , γ _aA , α _bA , β _bA ,
γ _bA ] Reference color data having a color coordinate B ₁ having a phase angle H _1B larger than the phase angle H _1T of the color coordinate X ₁ and being as close as possible is selected from the database. The illustrated color coordinate B ₁ represents the yellow-based reference color B.

Color correction coefficient of reference color B: [α _LB , β _LB , γ _LB , α _aB , β _aB , γ _aB , α _bB , β _bB ,
gamma _bB] in the color plane a ^* b ^* first quadrant, the color coordinates X ₁ of the target article, the reference color A, none of the color coordinate A _1, B ₁ and B is present, color planes a ^* b ^* of X ₁ exists inside the fan shape sandwiched by two straight lines extending from the origin 0 to A ₁ and B ₁ . The color coordinate X ₁ corresponds to an intermediate color between red and yellow. FIG. 5 (T ₀ ) shows the color coordinates A ₀ and B ₀ of the reference colors A and B in the lowered temperature state (T ₀ = 30 ° C.).

From the color coordinates A ₀ , B ₀ , the color coordinates X ₀ [L ^* _0T , a ^* _0T , b ^* _0T ] in the temperature-decreasing state of the target article are predicted. The following color value correction formula (1) is used. Color value correction equation _{^{(1): L * 0T =}} f LB | H 1T -H 1A | / | H 1B -H 1A | + f LA |
_{H 1B -H 1T | / | H} 1B -H 1A | a * 0T = f aB | H 1T -H 1A | / | H 1B -H 1A | + f aA |
_{H 1B -H 1T | / | H} 1B -H 1A | b * 0T = f bB | H 1T -H 1A | / | H 1B -H 1A | + f bA |
H _1B −H _1T | / | H _1B −H _1A | Here, f _LA , f _LB , f _aA , f _aB , f _bA , and f _bB are obtained by the color value correction coefficient formulas (A) and (B).

Color value correction coefficient formula (A): f _LA = α _LA (L ^* _1T ) ² + β _LA (L ^* _1T ) + γ _LA f _aA = α _aA (a ^* _1T ) ² + β _aA (a ^* _1T ) + Γ _aA f _bA = α _bA (b ^* _1T ) ² + β _bA (b ^* _1T ) + γ _bA f _LA , f _aA , and f _bA are the temperature drop states of the target article using the color value correlation formula for the reference color A. Means the result of predicting the color of. Color value correction coefficient formula (B): f _LB = α _LB (L ^* _1T ) ² + β _LB (L ^* _1T ) + γ _LB f _aB = α _aB (a ^* _1T ) ² + β _aB (a ^* _1T ) + γ _aB f _bB = α _bb (b ^* _1T ) ² + β _bB (b ^* _1T ) + γ _bB f _LB , f _aB , and f _bB are the color values of the reference color B, and are _calculated by It means the predicted result.

The color coordinate X ₀ of the target article obtained by the color value correction equation (1) is the predicted color value (f _LA , f _aA from the reference color A).
f _bA ) and the predicted color value (f _LB , f _aB , f _bB ) from the reference color B
And are obtained by geometrically interpolating and correcting the color coordinates A ₁ , B ₁ and X ₁ based on the relative phase angle relationship.
The above description is for the case where the color coordinates X ₀ , A ₁ , and B ₁ of the target article are all present in the first quadrant of the color plane a ^* b ^* . The same calculation can be performed when the color coordinate X ₀ exists in the second to fourth quadrants of the color plane a ^* b ^* . However, if any of the color coordinates A ₁ and B ₁ exists in a quadrant different from the color coordinate X ₁ , the color value correction formula (1) is corrected. Specifically, for example, color coordinates X ₀ and B ₁ is the first quadrant, when the color locus for A ₁ is in the fourth quadrant, in place of the phase angle H _1A, substituting the phase angle H _1A + 360 °. If the color coordinates X ₀ and A ₁ is the fourth quadrant, the color locus for B ₁ in the first quadrant, in place of the phase angle H _1B, it may be substituted for the phase angle H _1B + 360 °.

[Example of color measurement] By applying the color measurement method described above,
The color of the specific article was measured. The target article was manufactured by injection molding using a polypropylene resin material. The color was measured immediately after production. The temperature of the article was 50 ° C. 3 items
Color measurement was also performed in a temperature-reduced state in which the temperature was cooled to 0 ° C. From the color measurement result in the temperature rising state, the color in the temperature falling state was predicted using the color value correction formula. The error between the predicted value and the colorimetric value in the lowered temperature state was evaluated by the color difference ΔE ^* . For the standard colors A and B,
From the result of measuring the color in advance in the temperature rising state and the temperature falling state,
The correction coefficient has been obtained. <Example 1> The color of the target article is orange, and L ^* a ^*
b ^* Located in the first quadrant of the color space. The reference color A (red type) and the reference color B (yellow type) are also in the first quadrant.

[0053]

[Table 1]

<Example 2> The color of the target article is green and is located in the second quadrant of the L ^* a ^* b ^* color space.
(Yellow) and the reference color B (Green) are also in the second quadrant.

[0055]

[Table 2]

<Embodiment 3> The target article has a pink color, is located in the fourth quadrant of the L ^* a ^* b ^* color space, and has a reference color A.
(Blue) is the color of the fourth quadrant, and the reference color B (red) is the color of the first quadrant. In this case, the color value correction formula (2)
In, in place of H _1B, calculated by substituting the _{H 1B '= H 1B + 360} °.

[0057]

[Table 3]

<Evaluation> (1) According to the above measurement results, in the temperature rising state and the temperature falling state,
The colorimetric values of the same item are very different. It can be seen that if the colorimetric value in the temperature rising state is directly used as the color of the article, there will be too many errors and it will be inaccurate. On the other hand, in the predicted value of the temperature drop state by the colorimetric method of the present invention, the error with respect to the colorimetric value, that is, ΔE ^* is significantly smaller. The color difference ΔE ^{* from} the colorimetric value at 30 ° C. is so small that it can be ignored in practice. (2) Of the correction coefficients for the reference colors A and B, α _L , α _a , α
_b was 0 in most cases. From this, it can be inferred that even if the term of the α coefficient (quadratic term) in each correction equation is omitted, the prediction accuracy does not decrease so much.

(3) When a similar color measurement was carried out on an achromatic (black and white) article, no color difference was observed between the temperature rising state and the temperature lowering state. From this, it can be inferred that the L ^* value representing the lightness does not significantly affect the prediction accuracy. In the color value correction formula (2) described above, even if the phase angle H is defined by the a ^* b ^* plane angle instead of the solid angle,
This proves that sufficient accuracy can be obtained. [Usage Technology] The technology can be used in any technical field requiring ordinary color measurement and color matching. For example, the following uses are listed.

<Manufacturing of flooring material for construction> As a flooring material for construction, a strip-shaped plate material made of wood or the like is manufactured, and a colored coating film or a protective coating film is formed on the surface thereof. The coating film is cured by heating. The finish color of the flooring material depends not only on the color of the coating material, but also on the color of the natural wood material. It is also susceptible to environmental conditions such as climate. Therefore, the non-contact color measuring device 2 is provided on the running path of the flooring material after the heat curing process.
0 is arranged, and the flooring material (target article) in the temperature rising state is subjected to color measurement. Predict the color at the time of flooring construction from the color measurement results in the temperature rising state. When the difference from the target color designed in advance becomes large, the target color is immediately adjusted by changing the composition of the coating material or the processing conditions. An alarm can also be issued when the difference from the target color exceeds the allowable value.

The colorimetric information is processed by a computer,
It can also be incorporated in an automatic production line by automatically controlling the toning part that mixes the materials of the coating film. <Continuous Paper Making Process> It can be applied to a process for continuously producing colored paper. In the production of colored paper, a method is known in which a dye or pigment is mixed with a paper pulp liquid, the colored paper pulp liquid is continuously made into paper, dried by heating, and then wound to produce a colored roll paper. A non-contact type color measuring device is installed on the running line of the colored paper which has just been heated and dried and is in a temperature rising state. The color of the colored paper is measured, and the color is predicted from the result. When the difference from the target color is evaluated and the formulation of the colored paper pulp liquid is corrected, a colored paper having a constant color is always obtained.

<Color Steel Sheet Production Line> In the production of color steel sheets, a method is known in which a coiled steel sheet is pulled out and continuously run, and the surface thereof is baked and painted to color the surface. Even if you do not wait until it cools, you can measure the color of the temperature-raised steel plate that has just finished the baking process.
It is possible to quickly evaluate the color of the color steel sheet. Also in this case, if the composition of the baking paint is changed based on the color measurement result, it is possible to efficiently produce a color steel plate with stable color quality. <Color measurement of resin pellets> Applicable to the production of resin pellets which are raw materials for resin molding.

The resin pellets are produced by melt-kneading a material in which a colorant and a resin are mixed in advance, extruding the material into a string shape, cutting the material into appropriate lengths, and cooling and solidifying. The color of the resin pellets determines the color of the resin molded product that is finally manufactured, and thus strict control and adjustment are required. While the resin pellets are completely cooled to room temperature,
If the color of the resin pellet is measured, the color of the resin pellet can be evaluated immediately. If the material composition is changed based on the evaluation result, the color of the resin pellet can be strictly controlled.

[0064]

In the colorimetric method for heat-produced articles according to the present invention, the color of the temperature-decreased state can be immediately obtained by measuring the color of the article in the elevated temperature state immediately after the production. Since it does not take time and effort to cool or wait for the article to cool down, quick and accurate color measurement can be performed. As a result, in the toning work in which the manufacturing of the article and the color measurement are repeated,
There is no unnecessary waiting time, and the efficiency of color matching work can be measured. In a product production line, by immediately performing color inspection on a product immediately after manufacturing, a defective product can be promptly found, and correction or inspection of production conditions can be started. It is possible to reduce waste of defective products sent out until defective products are detected or production is interrupted, and productivity can be improved.

[Brief description of drawings]

FIG. 1 is an overall structural diagram of a color matching device that represents an embodiment of the present invention.

FIG. 2 is an overall structure diagram of the color matching device showing the next work stage.

FIG. 3 is an overall structural diagram of the color matching device showing the next work stage.

FIG. 4 is a block flow chart showing the overall flow of the automatic color matching system.

FIG. 5 is a graph illustrating a color prediction method for a target article.

[Explanation of symbols]

10 Injection molding equipment 12 Fixed mold 14 Movable mold 20 Color measuring device 22 Colorimeter 30 Transfer device 40 computers 42 information line 50 Resin supply section P pellet R Molten resin s Color matching sample plate

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Manji Tsuji             1-35 Morimoto, Itami City, Hyogo Prefecture             -Inside the Osaka factory (72) Inventor Michinari Nakase             1-25 Miyagi, Adachi-ku, Tokyo Sumika Ka             Ra Co., Ltd. Tokyo factory F term (reference) 2G020 AA08 DA02 DA05 DA14 DA15                       DA21 DA34 DA35 DA52

Claims (5)

[Claims] 1. A method for measuring the color of an article manufactured through a step including heat treatment, comprising: measuring the color of a target article which is still in a heated state after the manufacturing, to obtain a color value in the heated state. And (b) a step of correcting the color value of the temperature-increasing state to a color value of the temperature-decreasing state, based on the temperature-color correlation of the article obtained in advance.
A method for colorimetry of a heated article, including: 2. The step (b), as the temperature-color correlation, measuring a plurality of reference articles having different colors under different temperature conditions to obtain color values under different temperature conditions ( temperature-color obtained by a method including c1) and a step (c2) of obtaining a color value correction expression between different temperature states from color values obtained in the previous step (c1) in different temperature states In the color space that specifies the color by the coordinate position using the correlation of, the color obtained for a plurality of reference colors having coordinate positions on both sides of the coordinate position of the color in the heated state of the target article. Interpolate the value correction formula to the color value correction formula for the color of the target article,
The colorimetric method for a heated article according to claim 1, wherein the coordinate position of the color of the target article in the temperature rising state is corrected to the coordinate position of the color of the target article in the temperature decreasing state. 3. In the step (b), the color space is an L ^* a ^* b ^* color space having coordinate values of L ^* , a ^* , and b ^* color values, and the color value correction formula is: It is represented by a correction formula for each color value of L ^* , a ^* , and b ^* , and the plurality of reference colors have a hue angle H ₁ of a color in a temperature rising state of a target article in the L ^* a ^* b ^* color space, The colorimetric method for a heating manufactured article according to claim 2, wherein the reference color is selected so as to have an intermediate value of the hue angle H ₁ of the plurality of reference colors in the temperature rising state. 4. A toning method for adjusting a color of an article manufactured through a step including heat treatment to a predetermined target color, wherein the material composition of the article is adjusted according to the target color. (M), a step (n) of manufacturing an article through a step including the heat treatment using the material prepared in the step (m), and the article obtained in the step (n), Item (1) is measured by the colorimetric method according to any one of (1) to (3) to obtain a color in a lowered temperature, and the color of the article obtained in the step (o) and the target color are compared. Of the heat-produced article including a step (p) of re-adjusting the material composition of the article based on the result, and a step (q) of repeating the step (n) using the re-adjusted material. Toning method. 5. An apparatus used in the color-matching method according to claim 4, wherein the color-measuring apparatus measures the color of the target article obtained in the heating manufacturing step and still in a temperature rising state, and the color-measuring apparatus. The colorimetric information obtained in step 1, the target color information, and the information about the material composition of the article are input,
An information processing device that compares the colorimetric information with the target color information, corrects and calculates the material composition so that the color of the article to be manufactured next approaches the target color, and outputs the corrected material composition information, A color matching device, comprising: an information communication unit that transmits colorimetric information from the color device to the information processing device.