JPH0680237B2 - Inkjet dyeing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an ink jet dyeing method, and more particularly to an ink jet dyeing method capable of expressing a good quality intermediate color and having good color reproducibility with an original image.

(Prior Art) Color ink jet printers have been developed in recent years, and many models have been mass-produced. Basically, these color expressions are carried out in correspondence with the RGB signals of light by using four complementary color inks of yellow, cyan, magenta and black. In this case, the intermediate color is represented by the number of dots or the size of dots per minute unit area (1 pixel). In principle, increase the resolution 1
By increasing the number of dots in pixels, it is possible to express a lot of intermediate colors, but in reality there are limits in terms of cost, accuracy, reliability such as nozzle clogging, printing speed, etc. The current situation is that only color expressions are obtained. 4 shades to improve the intermediate color expression
It has been proposed to use primary colors (JP-A-53-10203).
4, JP-A-58-65666, JP-A-58-201665, etc.). As a result, the range of representation of intermediate colors can be expanded considerably. However, many problems arise when trying to apply ink jets to textile printing of fibers. When dyeing fibers, a delicate and high-quality color tone is required, but when trying to express an intermediate color by the above Dot Tomato Rix, it is very often impossible to obtain a color completely the same as the desired color. Since it is expressed in color, there is a problem that defects such as "irritation" and "moire" occur especially in light colors.

In order to solve this point, it is desirable to use an ink prepared in advance in a desired color, which is disclosed in JP-A-51-9338, JP-A-54-68635, JP-A-56-92092, and JP-A-58-205772. Have already proposed this concrete. However, under the present circumstances, no means has been found for obtaining dyes with high color reproducibility and high quality which are particularly required for dyeing fiber structures.

(Problems to be Solved by the Invention) An object of the present invention is to provide an ink jet dyeing method capable of obtaining a high-quality printed matter having a high degree of color reproducibility and “irritation”, “moire”, “bleeding” and the like. is there.

(Means for Solving Problems) The object of the present invention can be achieved by the following means. That is, when dyeing or printing a fiber structure by an ink jet method, a desired color ink is obtained by mixing two or more kinds of (A) a master ink of at least three colors and a diluted ink containing no dye, and (B) This is achieved by using a master ink and a diluting ink having substantially the same viscosity and anti-bleeding ability, and (C) making the amount of each desired color ink applied per area substantially the same.

In the present invention, as the fiber structure, various natural fibers,
Fibers, yarns made of recycled fibers, semi-synthetic fibers, synthetic fibers,
It refers to a woven fabric, a non-woven fabric, etc., and the material and structure are not particularly limited.

In the present invention, various known methods are used as the ink jet means. Typical examples thereof include, but are not limited to, a charge control type continuous method and an on-demand method.

In a color ink jet system, a system that uses an ink formulated to a desired color without using the four primary colors (hereinafter referred to as a blended color system) usually has the following problems.

(1) It is necessary to prepare as many nozzles as the number of colors of the color design, and it is difficult for the device to support multiple colors (for example, 30 colors or more).

(2) It is complicated because ink preparation, nozzle cleaning, and ink switching are required each time the color design changes.

These problems are fatal in an ordinary computer or a color ink jet printer as a hard copy of a color video, and therefore, four primary color inks are adopted in these. However, the above problems are not fatal when the ink jet technique is applied to dyeing and printing of fibers. That is, in (1), the design of the textile print is usually about 2 to 20 colors, and most of them are 10 colors or less. In textile printing, the quality of each color (color tone, uniformity, depth, etc.) is more important than the number of colors. Therefore, most of the current text tile printing technologies, such as screen printing, use a mixed color system. However, in the current textile print, the problem (2) becomes a problem. That is, every time the design changes, operations such as plate switching, cleaning, and color paste preparation are necessary, and there is a need for improvement. When the primary color ink jet is adopted, this problem will be eliminated, but on the other hand, the problem remains in the color expression as described above. In the case of mixed color system ink jet, part of the problem of (2) remains, but switching of the plate is unnecessary, and the ink switching operation is lower in viscosity than the current printing paste and the cleaning property is It will be improved.

The present invention provides an ink jet dyeing method that improves the color reproducibility and the quality, which are problems when trying to put such a mixed color ink jet system into practical use.

Computer color matching has begun to be used in dip dyeing and screen printing as a means of obtaining a dye mixture for obtaining a desired color. This is to obtain a dye prescription for obtaining a desired color by calculation based on the dye and dyed product data input in advance. The present invention solves the problems that occur when this concept is applied to ink jet dyeing / printing.

In the present invention, the following three are essential requirements. That is, (A) a desired ink is obtained by mixing two or more kinds from a group consisting of at least three colors of master ink and a dye-free diluted ink, and (B) having substantially the same viscosity and bleeding prevention ability. Using the master ink and the diluting ink, (C) making the applied amount per area of each compounded ink substantially the same.

The essence of the present invention is not carried out by adjusting the number of dots per unit area or the size of the dots, that is, the applied amount, which is usually adopted in an ink jet, especially in the expression of shades of color, and the dye concentration in the ink is changed. Is constant, and any blending concentration ink uses a master ink and a diluent ink that have the same ink viscosity and bleeding prevention ability so that the same droplet size (application amount) and bleeding behavior are exhibited. is there.

As the master ink used in the present invention, it is necessary to use three or more colors of ink in order to express various compound colors. It is not necessary to use cyan, magenta, and yellow as complementary colors of light for the hue of ink, and yellow, orange, scarlett, red, rubin, blue, navy blue, brown, violet, green, black, etc. used for ordinary dyeing are used. Selected from.

The genus of dyes is not particularly limited and is appropriately selected depending on the fiber material. Typical examples include acid dyes, direct dyes, reactive dyes, cationic dyes, disperse dyes, and pigments.

The dye concentration of the master ink is required to be a sufficient amount for expressing a dark color, and it varies depending on the dye, but a dye raw material having a dye concentration of 2 to 15% is usually used.

Although the solvent of the ink is not limited, the ink containing water as the main medium is preferably used.

The components blended in the master ink may include various components blended in the ordinary ink jet ink. As examples, glycol components as anti-drying / wetting agents, fungicides, chelating agents, pH adjusters, surfactants,
Examples thereof include viscosity modifiers, defoamers, dispersants, binders, and agents for preventing bleeding.

Next, in the present invention, in addition to the master ink, a diluted ink containing no dye is used.

In the present invention, each color of the master ink and the diluted ink are characterized by having substantially the same viscosity and anti-bleeding agent.

Here, when the ink viscosity is 10 cp or less, the difference is within about 2 cp, preferably within 1 cp, and when it is 10 cp or more, the difference is within 20% of the viscosity, preferably 10 cp.
It is within the numerical value within%. Further, the substantially same bleeding preventing ability means that the diffusion pattern when 5 μl of ink is dropped on the fiber structure is almost the same and the difference in the major axis portion is within 2 mm. Such an ink, particularly a diluting ink, can be obtained by finely adjusting the additive component based on the ink composition obtained by removing only the dye component from the master ink. For example, as a drug for finely adjusting the viscosity,
Examples thereof include nonionic or anionic water-soluble polymers. Specifically, nonionic ones include polyethylene glycol and derivatives thereof of various molecular weights, polyvinylpyrrolidone, polyvinyl alcohol, and the like, and anionic ones include sodium alginate, carboxymethylcellulose, and sodium polyacrylate. A nonionic type having a small influence on the ink characteristics other than the viscosity is preferably used. These chemicals are not essential components and can be added in a small amount to the ink as needed. Other important properties are surface tension, anti-drying agent, pH,
This is the amount of chemicals added to prevent bleeding.

When the master ink and diluted ink of the present invention are used, all inks from ultra-light color to dark color have a substantially constant discharge amount from the nozzle head and the same bleeding prevention ability.

Next, in the present invention, it is necessary that the application amount of each desired color ink per area is substantially the same. This is important in terms of color reproducibility and the quality of dyeing and printing (level dyeing and bleeding). In the present invention, in order to make the applied amount constant for each color, the number of dots per unit area may be made constant. That is, in the present invention, as described above, any of the mixed color inks is ejected with the same dot size and has the same bleeding behavior, so that if the number of dots is constant, the applied amount per area can be constant. .

In the present invention, the applied amount is not particularly limited, but it is desirable that the applied amount is the entire amount without any unapplied white spots on the surface of the fiber structure. Depending on the basis weight of the fiber material and fiber structure,
Usually, the amount of applied ink Xg / m ² is preferably in the range of 0.05 × A ≦ × ≦ 0.5 × A (where A represents the basis weight g / m ² of the fiber structure).

Under such a condition that the entire surface is applied, many fiber structures require some kind of anti-bleeding means.
In the present invention, the bleeding preventing means is not limited to these, but a method of heating the cloth and a method of pretreating the cloth with a water repellent or conversely an ink absorbent can be used. Further, a method of thickening (gelling), aggregating, and coagulating the ink by the reaction between the additive in the ink and the cloth pretreatment agent can be used. This method is a preferable method because the degree of bleeding does not largely depend on the fiber structure and is substantially constant.

In the present invention, the dye composition for obtaining the desired color is preferably calculated by calculation from the basic data of the master ink dye which is input in advance. The calculation method is known,
For example, Yukio Murata "About computer color matching"("Dyes and chemicals" voL30 (No12) P338-357, 1985)
It is described in. In the present invention, as the input data, it is possible to input the ink jet print at various dye concentrations with the master ink-diluted ink.

The present invention is illustrated in FIG.

Here, A, B, C, ... Are master ink tanks, Z is a diluting ink tank, 10 is a metering pump, M1 to M8 are compounded ink tanks, and H1 to H8 are ink jet heads for M1 to M8. Although the eight-color nozzle is illustrated here, it is of course possible to take an arbitrary number. 20 is a fiber structure. 30
Indicates a computer, and 40 indicates a skiner. The original image is input as image data separated into eight colors by a color scanner or the like. From the reflectance curve of the desired color and the color data, the blending ratio of the master ink and the diluted ink for reproducing the curve is obtained by calculation, and a batch pump or continuous supply and mixing is performed by a calculation pump. The required ink amount can also be obtained from the printing area. When changing colors, M1 to M8,
It is sufficient to wash or replace H1 to H8. If only the design is changed, washing and replacement is unnecessary.

(Effects of the Invention) As described above, in the present invention, the compounded color can be compounded from the master ink of any color, so that the hue can be reproduced well and rational compounding can be performed, and the ink is uniformly applied to the fiber structure Since it is constant, it has a characteristic that good quality is obtained for all colors.

(Example) Master inks of the disperse dyes shown in Table 1 were prepared for polyester fibers. This ink contains an anionic water-soluble polyester for preventing bleeding, and exhibits good bleeding prevention property when ink-jetted onto a cloth pretreated with a metal salt or a cationic agent. As a dye cloth, dry with a solution of calcium chloride 50g / l
%, Dry 120 ° C) polyester palace fabric (weight: 95g)
/ m ² ) was used. As an ink property, the ink viscosity is adjusted to 3.5-by using polyethylene glycol (molecular weight 20000).
It is almost the same as 4.1cp. The bleeding property was indicated by the long diameter of the spot after 1 hour after applying 50 μl of the ink using the above pretreated cloth. When only water was used as a dilution ink for comparison, a dilution ink was prepared using water and a drying inhibitor. The comparative ink does not contain an anti-bleeding agent,
Since the viscosity is not adjusted, it has a large bleeding by itself and has a lower viscosity than the master ink.

Four types of compounded inks were mixed and prepared using the master ink and the diluted ink. Table 2 shows the compounding ratios and physical properties of the prepared inks. The ink has substantially the same physical properties as the master ink I was there. This ink was used for ink jet printing under the following conditions.

Inkujietsuto method: on-demand serial nozzle diameter: 60 microns applied voltage: 40V Resolution: 8 dots / mm nozzle - Cloth distance: 1 mm ink application amount is any inks 22~24g / m ² is constant, there is no bleeding The quality was good and the dyeing was uniform and the difference in hue from the desired color was small.

On the other hand, the comparative diluted inks 1 and 2 were used as the diluted inks to prepare the compounded inks shown in Table 3. Particularly, the light-colored compounded ink has a low viscosity and a low bleeding preventing ability. Similarly, when ink-jet printing is applied, the applied amount is 28 to 29 g / m ² for lightly colored beige and green, which is higher than others.
Bleeding was also observed in a darker color than the desired color.

[Brief description of drawings]

 FIG. 1 is a schematic explanatory view of the method of the present invention.

Claims (2)

[Claims] 1. When dyeing or printing a fiber structure by an ink jet method, a desired color ink is obtained by mixing two or more kinds of (A) a master ink of at least three colors and a diluted ink containing no dye. ,
(B) An ink jet characterized by using a master ink and a diluting ink having substantially the same viscosity and anti-bleeding ability, and (C) making the applied amount per area of each desired color ink substantially the same. Staining method. 2. The desired color ink according to claim 1, wherein the mixing ratio of the master ink to the desired color is obtained by calculation from the basic data of the master ink dye which is input in advance and measured and mixed to obtain the desired color ink. The ink jet dyeing method described.