JPH08209553A - Color addition processing of leather and processing unit therefor and color-added leather produced by using the processing unit - Google Patents

Abstract

PURPOSE: To provide the subject new method capable of giving highly accurate images excellent in fastness and capable of quickly forming multicolor images. CONSTITUTION: This color addition processing method for leathers is made up of the following two processes: earlier process: a droplet penetration controlling agent chemically reactive with an ink coloring material is applied to a leather surface area to be subjected to ink color addition by a droplet spray means on the surface of the leather to be subjected to image formation by a droplet spray means; and later process: an image controlling agent chemically reactive with at least the ink coloring material on the leather surface area already subjected to ink color addition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for forming an image on leather made of tanned or retanned leather and fur, which is particularly highly accurate. The image forming method, and the addition processing method and the addition processing apparatus for achieving the simplification and speeding up of these working steps, and the leather or the processed leather obtained after the addition processing is completed. Regarding leather products.

[0002]

2. Description of the Related Art In general, leather, especially natural leather, is defined as a general term for leather obtained by removing tanned leather peeled from animals and tanning it, and further fur tanned with hair still attached. From the preparation process to the tanning process, which is the process from raw leather to tanning, industrially, the following steps are performed.

First of all, for the hide obtained by peeling from an animal,
After undergoing each step (preparation step) of soaking, lining, depilation / lime pickling, division, exfoliation, relime pickling, demineralization / fermentation,
Tanning to make leather with flexibility and heat resistance by using various tanning agents such as chromium compounds and vegetable tannins (tanning process)
Give. If you go to tanning without removing hair, you will get fur.
Usually, these steps are followed by finishing steps such as dyeing, greasing, seasoning, staking, painting, etc., and then processed into the final leather product.

Leather products are used in various fields by taking advantage of the texture of the leather itself. For example, footwear such as shoes, clothing, gloves, clothing such as belts, travel equipment such as bags, trunks, wallets, industrial parts such as belts and gaskets, chairs, furniture such as automobile seats, and others, There are a wide range of harnesses, musical instruments, kendo equipment, etc. In various fields, various animal hides and tanning methods are applied. The wide range of applications also brings about various types of durability and robustness required depending on the application.

In order to solve such a problem, there has been a method in which a texture is created by tanning, dyeing, and greasing, and thereafter, durability and solidity are further improved by drying and painting generally called finishing process. Has been.
Here, the basic method of the coating process includes pretreatment, lower and middle coating, and top coating. However, there are various methods for these steps depending on the use of leather and the type of aesthetic effect, and not all are in this order.

[0006] The conventional dyeing methods for leather include drum dyeing, haspering dyeing, brush dyeing, spray dyeing, etc. In general, the drum dyeing is generally used to uniformly dye the whole. Further, in the painting at the time of finishing, brush painting, spray painting, curtain painting, roll painting and the like have been conventionally used, and by these, leather having various characteristics can be finished.

Details of the process from dyeing to coating of these leathers are various depending on the kind of the product leather. Among them, the chrome leather is as follows. First, after undergoing the above-mentioned preparation step, the leather is made into a state suitable for the subsequent tanning work by removing unnecessary tissues and components by the chemical action and physical / mechanical treatment when it is made into leather. As this tanning process, soaking, chrome tanning,
Water squeeze, shave, and retanning. Then, as a finishing step, the process proceeds to neutralization, dyeing, fatliquoring, water squeezing / stretching, drying, seasoning, staking, tension drying, trimming, silver peeling, coating finishing, and weighing.

Further, since the above-mentioned dyeing method mainly uses a single color, the finishing step involves changing the surface shape due to embossing, suede, velor, nubuck, enamel, etc., so that it can be applied to various leather products. ing.

As described above, the leather products have various applications, but with the diversification of lifestyles in recent years, printing of multicolored and high-definition images is spreading in various product fields. The field of leather is no exception. Even in the past, some parts were used to create multicolored images by screen printing or hand-painting, but these methods are not enough to satisfy market demands in terms of image sharpness. It was

In addition to the image formation on the leather, there is also the current situation that the processing time during the leather production is long. In the various steps for the leather as described above, there are many processes for extracting water from the inside of the leather, such as water squeezing and drying, so that a long work is required in this part. Therefore, in leather production, it is difficult to carry out a continuous flow operation, and a batch operation is inevitable. Both water squeezing and drying use a treatment liquid containing a large amount of water in the previous stage treatment. The reason why such a treatment liquid must be used is that leather originally constitutes a living organism. This is because the natural product used as a raw material has to be changed chemically or physically as a whole. Therefore, a sufficient amount of treatment liquid is prepared for the leather to be treated.

As described above, in each of the steps, a large amount of processing time is required, and most of them are performed by batch operation. In the case of applying leather, further diversification is difficult in terms of production efficiency. However, the production of small lots and many kinds of products is naturally difficult. This can also be a barrier to a wide range of developments that take advantage of various properties of leather, such as feel, heat retention, low temperature dependence of physical properties, appropriate plasticity / elasticity, and strength of cut portion.

On the other hand, the whole leather is immersed in the treatment liquid, but the treatment process is not mainly for changing the physical properties of the leather, that is, for the purpose of dyeing the leather to impart a desired color and protecting the leather surface. Finish coating, etc. (Hereinafter, "finish painting" is abbreviated as "painting" in this specification.)
If the treatment liquid adheres to the leather sufficiently, it is possible to review the conventional method, but in reality it is difficult to establish an alternative method. It is still used today.

Among the conventional dyeing and painting of such leather, a large amount of dye liquor is used for dyeing, and the operation requires a considerable amount of time.
In the case of the most common drum dyeing, the neutralized leather is
While rotating in a drum with warm water of about twice the leather weight at about 50 ° C., a dyeing solution dissolved in about 10% of warm water is added thereto, and the drum is rotated for about 30 minutes. After that, the leather is taken out of the dyeing solution and dried to produce dyed leather. Therefore, the leather was dipped in a dyeing solution containing the coloring material in water, and the coloring material was sufficiently permeated into the leather over a period of time. Therefore, treatment such as mechanical removal of water or drying by heat is inevitable after dyeing. This dyeing can therefore only be processed in a single color and the processing of small quantities of leather is inefficient.

Further, in the past, when the coating was carried out, it was conventionally done to adjust the appearance and durability of the leather whose texture and shape have been adjusted after the dyeing. belongs to. However, in the above-mentioned dyeing process, it is necessary to consider various coating agents depending on the finished state of leather, and it may not be possible to prepare only a specific coating agent in advance. In addition, although the mechanization has progressed considerably by the above-mentioned method, since a device different from the previous dyeing is used, during the transition from dyeing to painting, leather is transported or leather is applied to the painting device. There are many places that require manpower in terms of wearing. Especially because the shape of leather is not standard, it is difficult to automate the mounting.

[0015]

BACKGROUND ART In the realization of high-definition images on this leather,
It has already been proposed by the applicant that the method be an inkjet method. The image formation by the ink jet method is performed by ejecting and landing a plurality of fine ink droplets on the leather, and by the aggregate of these droplets, that is, the dots. The finer the dots, the more dense and high-definition image can be formed. However, as the dots to be recorded on the leather become finer, the behavior of the individual dots on the leather, that is, how the ink penetrates in the thickness direction of the leather and how the ink spreads on the surface of the leather. It was found that the specific gravity, which affects the quality of the resulting image, increases.

Dyeing on leather is the same as dyeing on fabric,
It can be argued by dyeing seats that can be associated with colorants, and more dyeing seats in leather are said to be more than in fabrics. However, unlike leather processed as a fabric like cloth, in the case of leather made by changing the physical properties by various processing steps while keeping the shape of natural skin taken from animals almost as it is,
It was found that the distribution state of the dyeing seats inside and on the surface is a medium that can be recognized as non-uniform from the viewpoint of inkjet coloring. It has also been found that the distribution of dyed seats becomes more difficult for inkjet coloring when the body parts that make up the original animal are different.

On the other hand, when attention is paid to the point of view of an image formed by ink jet color addition, the content of the coloring material used in the image prevents clogging of the ejection port caused by evaporation of the ink. In order to maintain the jetting stability of the ink jet droplets, it is necessary to keep the density to the minimum necessary, so it is necessary to have a sufficiently high density and color at the time of finishing. And it is preferable to maintain a high-definition image at a high level during this finishing process. However, if the coating state of the coating agent used for finish coating is non-uniform,
The quality of the image formed before that is also deteriorated. Especially in the field of inkjet recording,
Since the dot density is a fine density such as 300 dpi or 360 dpi, it has been confirmed that the state of image deterioration in the above-mentioned leather is more likely to appear, and the phenomenon that high density ink jet printing characteristics cannot be fully achieved occurs.

[0018]

DISCLOSURE OF THE INVENTION The present invention is based on the background art described above, in which an image is formed by partial addition capable of forming a single color or multiple colors in a desired region, preferably by an inkjet method. In the above, it is possible to control the dispersion of the permeation state of each dot on these leathers, the dispersion of the density depending on the difference in the permeation state of the color-adding ink, or the difference in the spread of the color-added droplet. The first problem is to prevent the dot shape from being disturbed. If this problem is left unattended, there arises a problem that a defective image sharpness due to partial color addition such as an inkjet method or a defective color mixture in a multicolor image occurs. The finer the set of dots, the greater the influence of these colored droplets on the image.

Since the first problem is that various image quality properties appear depending on the type of raw hide and the tanning method, and the tendency of further deterioration can be caused by an increase in image density, the conventional dyeing of leather is It can be said that this is a new technical issue due to another partial addition.

The second technical problem recognized by the present invention based on the above background art is extremely difficult to make a continuous continuous operation from dyeing to painting, and as a result, the time required for these treatments increases. It is to solve the problem. For this reason, the problem of the required time is great even in the case of mass production or in the production of a large number of small products. Further, the problem of waste of excess dyeing liquid and the problem of heat source for drying, which is derived from the dip dyeing method, cannot be ignored.

The second technical problem is a technical problem that can be an obstacle to the maintenance of the image and cost when the image is formed on the leather by the ink jet method.

The present invention has as its main object to solve at least one of the first and second technical problems in the above leather, but as will be understood from the following description, in addition to these problems, Alternatively, it also solves a single issue.

[0023]

SUMMARY OF THE INVENTION The present invention has been made in view of the above technical problems, and a first object of the present invention is to obtain a dot density when a multicolor image is formed on a leather by a droplet ejecting means. Irrespective of the above, it is to stabilize the state of permeation and bleeding of each droplet and achieve high-precision and robust image formation.

A second object is to realize a process in which the image is not deteriorated even in the finishing process due to the image formation by the droplet ejecting means, and accordingly, a multicolor image is formed. It achieves high precision and speed. Therefore, it is necessary to review the conventional method for leather production from a viewpoint different from the past so as to enable continuous operation and automation.

That is, the present invention establishes a color-adding processing method or its processing apparatus that works effectively from the viewpoint of performing image formation with partial color addition or multi-coloring on the leather using the droplet jetting means. Especially. In other words, it is also to overcome the challenges that arise in creating new fields for the use of leather.

The first aspect of the present invention is a leather color-addition processing method having a color-adding step in which image formation is performed on the leather by applying a droplet ejecting means to the leather.
As a pre-step of ink coloring by the droplet jetting means onto the leather with respect to the leather surface side where the image is formed by the droplet jetting means, at least a leather surface area to which ink is added can chemically react with an ink coloring material. An image control agent that chemically reacts with at least the ink coloring material of the leather surface region as a pre-process of applying the droplet permeation control agent and a post-process of ink coloring by the droplet jetting means onto the leather. And a post-applying step.

In this leather coloring method, the absolute amount per unit area of the droplet permeation control agent applied in the preceding step is per unit area of the image control agent applied in the subsequent step. Less than the absolute amount, and the absolute amount per unit area of the droplet permeation control agent applied in the preceding step is less than the amount of coloring material applied per unit area of the ink applied in the coloring step. The sum of the absolute amount per unit area of the droplet permeation control agent applied in the preceding step and the absolute amount per unit area of the image control agent applied in the subsequent step is given in the coloring step. The amount of coloring material applied per unit area of the ink is equal to or more than each, and further, the droplet permeation control agent in the preceding step and the image control agent in the following step are the same material. It is a feature.

Further, as a derivative of these, a color-adding step of performing image formation as color addition on the leather by using the droplet jetting means for the leather, and the leather surface side on which the image is formed by the droplet jetting means. With respect to the leather as a pre-process of ink coloring by means of a droplet jetting means, at least a pre-process of applying a droplet permeation control agent capable of chemically reacting with the coloring material of the ink to the leather surface region to be ink-colored, A method for color-treating leather colored by means of a step of chemically reacting at least ink in the ink-colored leather surface region with a coloring material as a post-step of color-adding ink by means of droplet ejection onto the leather. There is a subsequent step of applying the image control agent, and the absolute amount per unit area of the image control agent applied in the subsequent step is more than the absolute amount per unit area of the droplet permeation control agent applied in the previous step. Characterized by many, And a step additive color of forming an image using the liquid droplet jetting unit as additive color to leather against leather, as a step after the ink additive color by the droplet ejection device to 該皮 leather,
A leather coloring treatment method, comprising a post-process of providing an image control agent that chemically reacts with a coloring material of the ink in the ink-colored leather surface region, the leather being image-formed by the droplet ejecting means. As a pre-step of ink coloring by jetting droplets onto the leather on the surface side, there is a step of applying a droplet permeation control agent capable of chemically reacting with the coloring material of the ink to at least the leather surface area to which the ink is colored. However, the absolute amount per unit area of the droplet permeation control agent applied in the preceding step is smaller than the absolute amount per unit area of the image control agent applied in the subsequent step.

A second aspect of the present invention is a leather color-adding processing method including a color-adding step in which image formation is performed as color-adding to leather by using a droplet-jetting means for leather. In the leather coloration method, at least a modification treatment step capable of substantially modifying the droplet jetting image on the leather is a substantially continuous step with respect to the coloration step by the means. The quality treatment step is a substantially continuous step of one or more reforming treatments performed by using a droplet ejecting means, the reforming treatment step is a finish coating, the coloring step and the reforming step. Between the treatment step and the forced drying step, the droplet jetting means is an inkjet method, after the tanning step including retanning as the leather, neutralization, greasing, water squeezing, stretching and drying Leather, as well as seasonings and stains Use of leather that has been flattened and textured by king, tension drying, edge cutting, etc., and that droplets are jetted from the droplet jetting means to the silver surface and / or the flesh surface of the leather. Including.

Further, as a third aspect of the present invention that appears comprehensively in association with the above-mentioned first and second aspects of the present invention, there is provided an apparatus for executing the above-described leather coloring processing method, which is an image forming apparatus for leather. A leather characterized by comprising: an inkjet recording means for forming the leather as a color addition to the leather; and an imparting means for imparting to the leather a modifying agent capable of substantially modifying a droplet jet image on the leather. It is a color processing device.

An image is formed by the above-described leather coloration processing method, and
It is a leather product characterized by being formed by processing such leather.

As a fourth aspect of the present invention that appears comprehensively, there is provided a leather color-adding method having a color-adding step of performing image formation as color-adding on leather by using a droplet jetting means. As a step immediately before the ink coloring by the droplet jetting means onto the leather with respect to the leather surface side image-formed by the droplet jetting means, at least the leather surface area to which the ink is added can chemically react with the ink coloring material. An image control agent that chemically reacts with at least the ink coloring material of the leather surface area as a step immediately before the application of the droplet permeation control agent and as a step immediately after the ink coloration by the droplet jetting means onto the leather. Immediately after the step of applying, and in addition to the color adding step by the droplet jetting means, at least a modification treatment step capable of substantially modifying the droplet jetting image on the leather is a substantially continuous step. It is leather additive color processing method according to claim.

The term "leather" as used in the present invention mainly means natural leather, and is generally defined as a general term for leather tanned after depilation and fur without depilation. Take leather as an example. Further, the leather suitable for the present invention is not particularly limited, and can be applied to any kind of raw leather and tanning method. Examples of raw skins include mammals such as cows, pigs, horses, goats, sheep and deer, birds such as ostriches, and reptiles such as sea turtles, monitor lizards, pythons and crocodiles. In addition, regarding the tanning method, the tanning method applied depending on the form and use when making a leather product can be applied, and a typical chrome tanning or tanning tanning,
Alternatively, those that use mineral tanning agents such as aluminum tanning, zirconium tanning, titanium tanning, ferric salt tanning, etc., and organic tanning agents such as aldehyde tanning, and also naphthalene-based synthetic tanning agents, phenol-based synthesizing agents. Tanning agent,
Either tanning using a synthetic tanning agent such as resin tanning agent or tanning with oil or fat typified by chamois leather may be used. Also, a combination tanning method in which two or more of these tanning methods are combined is applicable to the present invention.

The term "additive color" is a general term including a single color or a multicolor, which is conventionally used as a general technical term, including dyeing, coloring, painting, and the like. Therefore, after the operation of adding color, the color material that becomes the color element is a form that penetrates inside the leather,
It includes any form such as a form in which the leather is adhered or partially penetrated only near the surface layer of the leather, a form laminated on the surface of the leather, and the like. In addition, in the present invention, when the color addition processing is performed, the conventional finish coating is also included. In this case, although the coloring material is not necessarily contained, the existence form of the non-volatile component contained in the coating material can be grasped in the same manner as the existence form of the coloring material described above.

The present inventor has found the following findings as a result of repeated studies on the behavior of the color-adding droplets for image formation (hereinafter simply referred to as "ink") after reaching the leather. That is, in order to homogenize the image, that is, to homogenize the colors and round each dot shape, it is necessary to keep the penetration depth of the ink in the thickness direction of the leather constant.
Furthermore, even after the completion of ink coloring, in order to add sufficient color developability and stability to the image formed there, the color material that is the source of the image can react appropriately so that image formation using the droplet ejecting means is possible. It has been found that it is particularly important in image formation by an inkjet method.

In order to control the permeation state of the ink in the thickness direction, or the apparent spreading of the ink on the surface, that is, the bleeding state of the surface, so as to obtain a desired form, viewed mainly from the surface of the leather. After the ink reaches the leather, the solvent or dispersion medium of the coloring material that is a constituent of the ink evaporates, and the coloring material solidifies on the spot, stabilizing the movement of the coloring material molecules inside the leather. It is effective to suppress the time until it does. However, since water is generally used as the solvent or dispersion medium here,
After reaching the leather, it takes some time to evaporate. By the time the evaporation is completed, the ink penetrates and bleeds in the leather, and the coloring material contained therein also advances in the same manner. Also, the behavior of this ink is
The presence or absence of adjacent ink dots, the difference in the area within the leather, etc. are also affected, so that the presence state of the color material in each dot varies. In the following description, ink permeation means ink permeation in the thickness direction of leather, and ink bleeding means apparent ink spread on the leather surface.

In order to suppress this variation, it is preferable to stop the evaporation of water in the ink, and it is considered that heat is applied to the ink that has reached the leather. It is not a preferable method considering the fact that it is vulnerable to high heat. Therefore, in controlling the permeation and bleeding of the above-mentioned ink, instead of the physical method by heat, when the ink reaches the leather, the coloring material contained in the ink or the solvent or the dispersion medium in the ink is used. It is preferable to use a chemical method that promotes the reaction of insolubilization or aggregation at a desired time.

Further, in order to add sufficient color developability and stability to the image even after the color addition, it is effective that the coloring material is sufficiently fixed in the leather. Regarding these achievements, applying uniform physical property changes to the entire leather, such as tanning and greasing, except for specific leather,
Difficulty occurs in terms of choice of treatment method and adverse effect on the unique texture of leather. However, if it is performed only on the colored surface area, the difficulty is eliminated. As a result, it is preferable that the coloring material in the ink, including the surface portion of the leather around it, be chemically fixed, that is, fixed.

From the above, in order to stably form an image, a component which can chemically react with the coloring material contained in the ink is used before and after the ink jet coloring step of ejecting the ink. It came to be applied to the upper colored surface area. That is, in consideration of the fact that as the coloring material contained in the inkjet ink or the coloring material conventionally used for dyeing leather, those having ionicity are often used, The color material is caused to undergo a chemical reaction by an ionic bond. The image includes both an image made on the entire surface of the leather and an image made on only a part of the leather. In the following description, anionic dye, which is most widely used as a coloring material and has many types, and an ionic bond with an anionic dye as a chemical reaction are taken as examples. Examples of the anionic dye include acid dyes, direct dyes, metal complex dyes, and reactive dyes. However, the anionic dyes are not limited to these, and may include pigments as long as they have an ionic property when formed into an ink. . Needless to say, a cationic coloring material can be easily applied by reversing the ionicity described below.

In the present invention, in order to control the permeation and bleeding of the ink with respect to the above-mentioned leather, first, the droplet permeation control agent is applied to the leather as a pre-coloring step. As a result, ionic bond between the coloring material contained in the ink and the droplet permeation control agent is generated during the process of the ink permeating or bleeding after the ink reaches the leather in the subsequent coloring process. And the result is
The colorant is insolubilized or dispersed into the solvent or dispersion medium that constitutes the ink. By setting the degree of ionic bond between the coloring material and the droplet permeation control agent to a desired state, it is possible to adjust the shape and density of each dot forming the image. Here, the degree of ionic bond can be changed by the applied amount of the droplet permeation control agent or the degree of ionization, that is, the number of charged portions in the structure of the substance used as the droplet permeation control agent.

The droplet permeation control agent is preferably cationic with respect to the anionic dye, but preferable materials include easy handling, easy presence in the leather, and compatibility with the leather. It is preferable that it has good properties and that it maintains cationicity inside the leather. For example, it can be used from among water-soluble cationic substances. When applying the cationic substance to leather, it can be realized by first making the substance into an aqueous solution state and applying or spraying a desired amount on the leather. Thereafter, this aqueous solution gradually penetrates into the inside of the leather, spreads from the surface to be colored of the leather to the inside, and the solvent water evaporates. At this time, the presence probability of the cation substance in the thickness direction of the leather becomes larger as the surface is closer to the surface.

Here, since the coloring material and the cationic substance come into contact with each other to function, the absolute amount of the droplet permeation control agent per unit area of the leather surface in the preceding step is per unit area of the leather surface of the ink. It works well even if it is less than the absolute amount. This also means that there is no extra substance attached to the leather, so the texture of the leather is not impaired,
The dyeing property of the coloring material in the leather itself is not hindered, and the permeation action of the coloring material can be controlled. In addition, because of the above-described action, there is no particular restriction on the time between application of the droplet permeation control agent and the addition of ink. For example, the process of applying ink after sufficient drying after application, or the process of evaporating the solvent after application, that is, a process immediately before ink addition, or a process of applying ink simultaneously with application, etc. I don't care.

An image is formed on the leather surface by the above-mentioned pre-process and color-adding process. However, as it is, a high-precision image is maintained in the finishing process which is performed after the color-adding and the subsequent leather product processing. Is not perfect.
Therefore, in order to further add color developability and stability to the image and maintain a desired image, an image control agent is applied to the leather as a post-process of coloring. By applying this image control agent, in the color-added area where an image has already been formed on the leather, the fixation of the color material is further strengthened by the reaction due to the ionic bond with the color material, and the color material is surrounded. Stabilizes the color image. Therefore, the area to which the image control agent is applied may be at least an area where color is added.

Since the action here is also caused by the contact between the coloring material and the cationic substance as in the case of the droplet permeation control agent described above, the image control agent is applied after the ink color is added. There is no particular restriction on the time until. For example, it may be either a step of applying an image control agent after sufficient drying after ink coloring or a step of ink permeation during coloring, that is, a step immediately after ink coloring.

However, in the subsequent step, a sufficient amount of the image control agent is required to be bound to the colorant molecules, and therefore a sufficient amount of the image control agent is required. Therefore, the relative relationship between the absolute amount S1 per unit area of the leather surface provided with the droplet permeation control agent as the previous step and the absolute amount S2 per unit area of the leather surface provided with the image control agent as the subsequent step is: In order to more effectively act on image formation, it is preferable that S1 <S2.

On the other hand, the applied amount S1 in the preceding step has a correlation with the absolute amount D of the coloring material contained in the ink applied in the subsequent coloring step per unit area of the leather surface. That is, the contact state between the two can change the progressing state of the coloring material in the ink inside the leather, but in that case, it is preferable that S1 <D in order to obtain the desired state without inhibiting the penetration of the ink. .

Further, in order to efficiently operate the effects of the pre-process and the post-process on various leathers or images,
It is preferable that S1 + S2 ≧ D. As a result, no unreacted portion remains with respect to the coloring material, and the applied amount of each of the coloring materials functions in a sufficiently small amount relative to the weight of the leather, so that the texture of the leather is not damaged.

As described above, in both the liquid drop permeation control agent and the image control agent, a cationic substance is used for the purpose of causing an ionic reaction with the coloring material. Specific examples thereof are as follows. It is something.

First, the following can be selected from the cationic substances containing a surfactant capable of promoting the permeation of liquid. For example, primary, secondary or tertiary amine salt type compounds such as laurylamine, coconut amine, stearylamine, rosinamine and the like hydrochlorides and acetates, lauryltrimethylammonium chloride, lauryldimethylbenzylammonium chloride, benzyltributylammonium chloride, Quaternary ammonium salt type compounds such as benzalkonium chloride, pyridinium salt type compounds such as cetylpyridinium chloride and cetylpyridinium bromide, imidazoline type cationic compounds such as 2-heptadecenyl-hydroxyethylimidazoline, dihydroxyethylstearylamine and the like Preferable examples include ethylene oxide adducts of higher alkyl amines.

Further, as a substance capable of increasing the apparent colorant molecule together with the colorant binding and aggregation, the following can be selected from the cationic polymer substances. For example, water-soluble cationic polymers such as polyallylamine salt, polyallylsulfone, dimethyldiallylammonium chloride, polyaminesulfone salt, polyvinylamine salt, and chitoate acetate are preferable. Further, even if it is usually nonionic, it is possible to use a substance obtained by adding a cationic group to a part of the substance. Specific examples include vinylpyrrolidone and aminoalkyl alkylate 4
Examples thereof include copolymers with a quaternary salt, copolymers with acrylamide and a quaternary salt of aminomethyl acrylamide, and the like. These substances are satisfactory if they are water-soluble, but they may be dispersions such as latex and emulsion. Other than water-soluble substances, the solvent is not limited to these as long as a solvent that does not attack the leather is used.

These droplet permeation control agents and image control agents are
One kind or two or more kinds may be blended and applied by appropriately selecting from the substance group exemplified above according to the leather on which an image is formed. Further, they may have different compositions or the same composition. Further, known surfactants, various binders and the like may be added, if necessary, in order to adjust the viscosity, volatility and the like depending on the required function and the kind of leather used.

Further, as a method of applying these, coating, spraying, etc. can be mentioned.
It is possible to use a roll coater, a spray gun, or an inkjet head for which the amount of application can be easily adjusted. In particular, the ejection from the inkjet head can give only the area to which ink is added in accordance with the image signal when the ink is added, so the texture can be suppressed to the minimum necessary for leather. Of course, the processing can be performed without damage, and it is also effective for color addition only in a partial area of leather.

Further, there is an invention of a further developed form, which is derived from the configuration described above. That is, it is not necessary to set restrictions on the time from the previous process to the color-adding process and the time from the color-adding process to the subsequent process. Rather, it is important that the processing agent used in the pre-process or the post-process is surely applied to the leather and the image in order to cause the reaction described above. Therefore, the pre-process, the coloring process, and the post-process do not necessarily have to be consecutive at the same location. That is, for the color-added leather that has been subjected to the step of applying the droplet permeation control agent in advance and the step of applying the color by the droplet ejecting means, it is performed at a different place or at a different date and time from when those steps are performed. The post-process of applying the control agent is also one of the present inventions. In addition, for leather that is set in advance to undergo the color-adding process by the droplet ejecting means and the post-process of applying the image control agent, before performing the process after the color-adding process at a different place or at a different date and time. The process is another invention.

Next, the second aspect of the present invention will be described.

With these constructions, focusing on the above-mentioned second technical problem, the clue of the improvement was found from the requirements of the conventional processes from dyeing to finishing. In the conventional process, since it is common to use a liquid processing agent in both dyeing and coating processes, a processing method is performed by applying a droplet jet, that is, an inkjet method to perform the processing process. We have achieved the simplification and substantial continuity of. Moreover, it has become possible to stably create high-definition multicolor images.

Generally, an ink jet head used in the ink jet system is constructed by integrating and arranging a plurality of liquid droplet ejecting nozzles. In operation, the ink jet head is made to scan at a constant cycle so that one of the plurality of nozzles is ejected. A drive signal is given to each one to control the ejection timing and ejection amount of the droplet for each nozzle. In other words, leather that has undergone tanning and retanning from the preparation process is subjected to flattening and texture adjustment by greasing, stretching, seasoning, etc. without dyeing, and then ink coloring with an inkjet method. It is possible to carry out the color-adding step of forming an image by the above, and subsequently the finish coating for modifying the image forming surface, that is, the modifying step, as a substantially continuous step.

That is, in the case of ink jet color addition, the ink is sprayed only on the portion where the image is to be formed to adhere and penetrate the leather, so that the coloring material in the ink does not adhere to the portion unrelated to the image. Therefore, the surface condition, texture, or dry condition of the leather does not change significantly before and after this coloring, so that it is possible to carry out a modification treatment, that is, coating, by an inkjet method subsequent to the coloring process. This has the effect of increasing efficiency and productivity, reduces the load of drying for solvent removal due to the use of a large amount of dye liquor, compared to the conventional dyeing and painting, and the amount of treatment liquid. Also, since it is possible to finely control the liquid droplets ejected from the nozzle of the inkjet head, it is possible to eliminate the waste of the used amount, simplify the coating film adjustment at the time of painting, and shorten the time. In other words, in the color addition process, the amount of ink corresponding to the minimum required color material can be used, so there is almost no need to wash off the undyed color material after that, and the color material can be effectively used. Becomes Further, the injection amount of the reforming treatment liquid can be set arbitrarily and can be adjusted to a constant amount, so that the adverse effect of impairing the texture and glossiness does not occur.

As a result, it is possible to freely and easily perform multicolor images and grayscale images, which could not be achieved by the conventional method. When performing inkjet color addition, it is important to keep the distance between the surface to be colored and the ink ejection port of the inkjet head always constant in order to maintain stable image quality. In the past, since the stretching work that was conventionally performed in the finishing process is performed before coloring, it is possible to attach flat leather to the coloring device and it is in a very good state for inkjet coloring processing. can do. Besides, seasoning, staking,
Since the moisturizing is already performed after finishing drying, the moisturizing which has been conventionally performed in the finishing step is unnecessary, and it is possible to avoid disturbing the image formed by the ink addition.

On the other hand, conventionally, the coating has been intended to protect the leather surface, and the inkjet modification treatment may be performed on the entire surface on which the image is present. Depending on the part,
Also in this respect, the inkjet method is easy to control. It is also possible to use a plurality of inkjet heads at the same time to change the type of processing liquid supplied to each inkjet head, or to change the type of processing liquid for each nozzle and to use these modified processing liquids according to the purpose. It's easy.

Further, in the conventional coating, it was general to apply multiple coatings by using various kinds of finishing agents in order to obtain a desired finished state of leather, but this is also a multistep inkjet reforming treatment step. It is also possible to make them parallel and continuous. Furthermore, by incorporating a coloring material into the modifying treatment agent according to the intended use of the leather product, it is easy to incorporate it as a continuous treatment device in the same manner.

As described above, by using the liquid droplet ejecting means, that is, the ink jet system, it is possible to carry out continuous color-adding processing steps, and it is possible to shorten the time required for each step and realize automation, but it is used in each step. Depending on the treatment agent, the treated surface may not reach a sufficiently treated state between the jetting and the subsequent step. In such a case, it is also effective to provide a forced drying step for the treated surface between the steps, if necessary. This is effective when it is provided between the color-adding process including the front-end process and the post-process that have different actions and the modifying process. And this process is also effective as a heat treatment for strengthening the binding between leather and tanning agents, greasing agents, etc., which makes the skin proteins less hydrophilic and strengthens the binding between leather and the treating agent. Is. In such a drying step, an appropriate temperature and time may be appropriately set according to the heat resistance property of the leather, and is not particularly limited. However, as described above, in the case of the treatment by the inkjet method, it is easy to eliminate the unnecessary application of the treatment agent, and therefore, even if these drying steps are simple, the function can be achieved.

On the other hand, it has been mentioned above that in the general dyeing of leather, the binding of protein collagen, which is the main component of leather, and dye molecules is discussed. It can be said that leather is inherently easy to dye because it is present in and is further increased by passing through tanning. Therefore, it can be considered that the penetrability of the ink is the same regardless of whether the surface of the leather is silver or flesh, and when the leather coloring treatment method of the present invention is applied Is applicable on either or both sides, all.

Next, the third and fourth aspects of the present invention will be described.

As described above, by implementing the method for coloring leather according to the present invention, a high-definition image can be realized on the leather. Here, as the ink jet device, a charge control type, an ejecting device using a piezo element, an ejecting device using a heating element, or the like can be adopted. Among them, the ejecting apparatus using a heating element is suitable because it is easy to increase the recording head density. is there. By applying these devices, the leather coloring processing method described above can be realized.

When the present invention is comprehensively realized, in addition to the above, when the coloring process and the modification treatment process are carried out as a substantially continuous process by an inkjet system, the inkjet system used. Since the head is scanned in a constant cycle to perform sequential processing, and the leather itself is also moved accordingly, it is possible to sequentially shift from the area where one processing is completed to the next processing. That is, the pre-process and post-process of the coloring process described in the first embodiment of the present invention can be simultaneously incorporated in these continuous processes. That is, it is possible to provide a color-adding process in which the process immediately before applying the droplet permeation control agent, the color-adding process, the process immediately after applying the image-controlling agent, and the modifying process are substantially continuous.

Hereinafter, the present invention will be specifically described with reference to examples.

[0067]

【Example】

(Embodiment 1) FIG. 1 is a flow chart showing a process from preparation of leather according to the present invention to leather products through coloring and modification treatment on the leather, and FIG. 2 is an ink jet device which is a droplet ejecting means in the present invention. FIG. 4 is a schematic diagram showing a main part of FIG. 4, and FIG. 4 is an overall configuration diagram showing an example of an inkjet color-addition processing device according to the present invention. The present invention will be specifically described based on these drawings.

In FIG. 1, the preparation process and the tanning process are
This is a process of making leather from raw leather by a method that has been conventionally used. In this embodiment, sheep sheep is used as the hide, which is subjected to chrome tanning and white treatment with titanium oxide. The sheep leather thus produced is neutralized with sodium bicarbonate using a drum, and subjected to a fatliquoring treatment in a drum with a fatliquor containing sulfite cod oil as a main component to impart flexibility. Conventionally, after this neutralization, dyeing liquid was added to the drum along with fatliquoring for dyeing, but in the present invention, dyeing is not performed here. Next, a setting machine is used to squeeze out excess water in the leather that has penetrated during neutralization and fatliquoring, and then squeeze and stretch it to a suitable size. After that, dry and dry and add seasoning,
By staking, it loosens up the leather and adds flexibility. After this, after drying with a net and edging, the sheep leather has an appropriate flat shape when it is mounted on an inkjet color-processing device, and it is possible to achieve fixation of a fatliquoring agent and an appropriate amount of water in the leather.

After the steps up to this point are completed, the process proceeds to each step of the color-adding process using the ink jet system. Here, in order to perform these process treatments efficiently, the sheep leather is attached to the transport support member 3 shown in FIG. The configuration of the transport support member 3 is such that the adhesive 32 having a relatively weak adhesive force is applied to the entire one surface of the flat steel plate 31 made of stainless steel. Since the adhesive 32 is provided only for the purpose of fixing the leather 2 so as not to shift, the adhesiveness may be such that the leather 2 does not peel off under its own weight.
Therefore, the leather 2 will not be damaged even when it is removed after the coloring is completed.

Thus, the sheep leather was fixed with the silver side facing outward, and the following droplet permeation control agent was first applied to the silver surface using a spray gun to give an adhesion amount after drying of 1 g / m ² . Spray so that In the following description, “%” indicating the mixing ratio of each component is based on weight unless otherwise specified. After this spraying, drying is performed at room temperature and normal humidity for about 1 hour.

After that, an image is formed on the silver surface which has been subjected to the above-mentioned treatment, by an ink jet coloring device. Since the sheep leather originally has relatively good water absorbency, even in this spraying operation, the time for the components to penetrate into the leather is fast, and the sheep leather is treated sufficiently without using drying means such as raising the temperature. Can be applied. Further, since the above-mentioned droplet permeation control agent contains a surfactant, it is possible to promote the permeation of the entire spray liquid into the leather. Therefore, each component in the droplet permeation control agent after drying can be in a state of permeating into the leather as shown in the schematic view of FIG. 5 (A), not in a state of being laminated on the surface. This FIG.
In the above, 2 is leather, and 201 is a droplet permeation control agent that has been sprayed and penetrated into the leather. To maintain such a state,
Since the surface condition of the coloring area of the leather can be almost the same as before spraying the droplet permeation control agent, it hinders the adhesion of the droplet itself during the coloring operation,
Nor does it change the texture of the entire leather.

Subsequently, an image is formed on the leather 2 by jetting droplets by using the ink jet coloring device shown in FIG.

Here, the operation of this ink-jet color-adding device will be further described. In FIG. 2, reference numeral 1 is an inkjet color processing device, 2 is leather to be colored, and 3 is a conveyance support member fixing the leather. Here, the inkjet head 1 which is the most important part when performing the coloring process
In No. 0, four ink jet units each having many nozzles (not shown) for ejecting liquid drops are arranged and provided on the carriage 12. Further, an ink supply device 11 capable of supplying ink for color addition to the inkjet head 10 is provided with a carriage 13.
It is provided above. And by connecting these through the tube 14, black, cyan, magenta,
The four color inks of yellow are filled in the respective compartments separated by ink to supply the ink from the ink supply device 11 to the inkjet head 10.
In accordance with a signal sent to the inkjet head 10 from 5, the two carriages reciprocate in the direction of arrow A in the figure to scan along the guide rails 17 and 18 attached to the frame frame 16, and
The ink jet head 10 starts ejecting ink according to the image signal, and the leather 2 can be colored. The leather 2 is moved in the direction of the arrow B each time the two carriages move back and forth.
That is, they are sequentially conveyed in the sub-scanning direction, and color is added to the whole. Since the leather 2 is fixed by the transport support member 3 here, it is possible to reliably mount the leather 2 on the inkjet color-adding device and transport it in the sub-scanning direction.

The leather 2 is colored by the above-mentioned operation. The permeation state of the jet droplets in the leather 2 at this time is as follows.
It is shown in FIG. In this manner, the droplets sprayed and permeated into the leather 2 have the same permeation depth into the leather and the surface spread within the region where the droplet permeation control agent has permeated, as in 206. Can be maintained. As a result, it is possible to achieve uniformity of image formation at the time of droplet ejection. On the other hand, in the case where the droplet permeation control agent was not applied,
When droplet ejection is similarly performed on the sheep leather of (A) by the inkjet coloring device of FIG. 2, the droplets are in a penetrating state shown in FIG. 6B. As described above, each droplet causes various states in the depth of penetration into the inside and the spread on the surface even if it is the same leather like 207, and as a result, nonuniformity of image formation occurs. To do.

After the addition of these colors, the following image control agent is continuously sprayed onto the silver surface of the imaged sheep leather in the same manner as in the case of spraying the droplet permeation control agent. Is sprayed so that the adhesion amount after drying is 2 g / m ² . Then, it is dried at room temperature and normal humidity for about 1 hour. Here, it is combined with the color material that is forming the image,
Furthermore, in order to cause the molecules to agglomerate to a large extent, the molecular weight of the polyallylsulfone that undergoes an ion reaction is set to be larger than that of the droplet permeation control agent. When this image control agent is sprayed, as shown in FIG. 5C, in the leather, the liquid gradually penetrates from the surface on which the image is formed, that is, the silver surface side. In this process, first, benzalkonium chloride, which has relatively high permeability, forms an ionic bond with the coloring material in the image-formed part, and then this bond is used as a trigger to form a co-dissolved polyallylsulfone. It is connected with the coloring material. By passing through these reactions, the molecules of the coloring material become apparently large, and as a result, it is possible to prevent the coloring material from moving in the leather, stabilize the color development, and make it insoluble in water. It will be possible. That is, the image is stabilized, and the water resistance also appears.

Droplet penetration control agent Benzalkonium chloride 3% Polyallyl sulfone (weight average molecular weight 10,000) 3% Water 94% Image control agent Benzalkonium chloride 1% Polyallyl sulfone (weight average molecular weight 50,000) 5% Water 94%

Through the above process, the image formed by ink jet coloring on the sheep leather can be a stable image in which the dot shapes of the droplets are uniform and the density is high.
In addition, since it contributes to the improvement of robustness such as water resistance, it can be sufficiently satisfied even in the finish coating performed in the next step.

By completing the steps so far,
Imaging on sheep leather was achieved. Subsequently, the process proceeds to the step of modifying the sheep leather on which the image has been formed, and the finishing is performed. FIG. 4 schematically shows a continuous process when the sheep leather is subjected to a modification treatment. In FIG. 4, as the modification treatment step, three steps, that is, each of the finish coatings of the undercoating, the intermediate coating, and the topcoating are continuously performed by the inkjet method by the modification treatment agent injection step. Further, as a component of each of these coating liquids, a coating liquid usually used in spray coating can be used. For example, urethane-based, acrylic-based, and casein-based compounds can be used by appropriately blending them as needed. Hereinafter, the above-mentioned sheep leather modification treatment step will be described with reference to this drawing. In this description, the first, second, and third modification treatment steps will be referred to as undercoating, intermediate coating, and topcoating, respectively.

First, the transport support member 3 to which the leather 2 on which the image has been formed as described above is fixed is installed in the transport section 111 which is configured to be transportable. Then transfer section 1
Reference numeral 11 transfers the transport support member 3 to the sub-scanning belt 103 of the first reforming processing unit 101 by a drive source (not shown). When the transport supporting member 3 reaches the portion of the sub-scanning belt 103, the transport supporting member 3 is subsequently rotated by 90 °, and the back surface of the stainless steel plate side is mounted on the sub-scanning belt 103. Here, the sub-scanning belt 103 is adapted to be fitted to the leather 2 so that the leather 2 can be moved to the spraying portion of the undercoat coating agent. After that, the sub-scanning belt 103 is U
The transport supporting member 3 moves to the upper portion in FIG. 4 along with the movement of the leather 2 at a constant speed, and moves the leather 2 to the spraying portion of the undercoat coating agent. With this move, leather 2
The undercoat coating is started from the end portion of the leather 2 while the back surface is supported by the platen 102. Even after the undercoating of the entire surface of the leather 2 is completed, the operation of the sub-scanning belt 103 is further continued, and finally the transport support member 3 reaches the leather lift 121. Then, the transport support member 3 is disengaged from the fitting with the sub-scanning belt 103 and is moved to the leather lift 121. The leather lift 121 is supported by the support 131 when the transport support member 3 is attached.
Then, the carrier support member 3 is moved to the transfer unit 112.

Thereafter, in the second modification processing section 104, the intermediate coating is continuously applied to the leather 2 which has been subjected to the above-mentioned undercoating. The operation here is the first modification processing step. In the same manner as in the above case, the transport support member 3 is
Attached to the second reforming processing unit 1 at a constant speed in the V direction.
When approaching the spraying unit 04, the intermediate coating liquid is sprayed by an inkjet device, then attached to the leather lift 122, lowered along the columns 132, and moved to the transfer unit 113. Further, the same operation is performed, top coating is performed in the third modification processing unit 107, and finally the transport support member 3 is transferred to the tip of the transfer unit 114, and modification processing of the leather 2, that is, finish coating. Is completed.

In these series of operations, the first reforming processing unit 101, the second reforming processing unit 104, and the third reforming processing unit 107.
Are carried out by an inkjet method, but the mechanism and operation of this part can be applied to the inkjet coloring device of FIG. 2 used in the previous ink coloring step, and therefore the description here will be made. Is omitted. The B direction in FIG. 2, that is, the sub-scanning direction corresponds to the U direction, V direction, and W direction in FIG. 4, respectively.
However, in the case of these modification treatments, the ink supply device 11 in the ink jet coloring device of FIG. 2 may be one room, and the coating liquid used for each may be filled in the room to perform the same operation as that at the time of coloring. You can let me do.

In this embodiment, the leather is moved during each process from the undercoating to the topcoating, but since it is incorporated in a series of operations, the leather is changed even in the portion where the coating material changes. There is no removal or transportation, and no manual parts occur. Further, since the leather movement between these steps is automatically performed, it is possible to save labor as compared with the conventional case. Further, it takes a certain amount of time to move the transport support member 3 to which the leather is attached between the above-mentioned steps, but the treatment immediately before that, that is, the drying of the coating, is performed by this time. It also has the effect of being.

By completing all the operations as described above, it is possible to form a high-definition image on the leather, image deterioration does not occur even in the finish coating, and the processing time can be shortened. From this point onwards, the characteristics of making a leather product are shown, so after measuring, various sewing is performed,
It can be finished into leather products such as bags.

(Embodiment 2) FIG. 7 is an overall configuration diagram of a color-adding processing device according to another embodiment of the present invention, and FIG. 8 is a schematic diagram showing a main part of an ink jet ejecting portion in FIG. These are different from the embodiment 1 in that the droplets are ejected vertically downward and the leather is conveyed in only one direction to simplify the operation. In this color-addition processing device, a color-adding process using ink is performed by the ink-jet ejecting unit 5, and a pre-process and a post-process for this color-adding are performed by the ink-jet ejecting unit 4 and the ink-jet ejecting unit 6, respectively.
Done in. Furthermore, the entire processing apparatus is configured so that the inkjet processing unit 7 performs the modification processing step.
In addition, in explaining the operation of this color-addition processing device,
The main operation of the inkjet method will be described with reference to FIG.

FIG. 8 shows the ink jet ejecting section 5 and the ink jet ejecting section 6 which are portions for performing the color adding step and the post step in the overall structure of the above-described color adding processing apparatus. The operation of the injection unit is basically the same as that described in the first embodiment.
In the inkjet ejection unit 5 provided here,
The inkjet head 50 that ejects the color-added ink as droplets is configured by arranging four inkjet head units each having a plurality of nozzles arranged therein. Further, the inkjet head 50 temporarily stores ink. The ink is supplied by being connected to the auxiliary ink storage chamber 51. In addition, the auxiliary ink storage chamber 51 has a chamber partitioned into inks of four colors of black, cyan, magenta, and yellow, and four inkjet head units of the inkjet head 50. Ink is supplied for each color. Further, ink of each color is supplied to each of the partitioned rooms from a separately provided ink supply device via a tube (not shown). The symbols K, C, M, and Y attached to the auxiliary ink storage chamber 51 represent black, cyan, magenta, and yellow, respectively. The inkjet head 50 and the auxiliary ink storage chamber 51 are both in the carriage 5
2 is provided in the carriage 52 by a signal sent to the inkjet head 50 from an electric system (not shown).
Along the guide rails 53 and 54,
While reciprocatingly moving in the direction of arrow C in the figure for scanning, the ink jet head 50 starts ejecting ink of each color according to the image signal, so that the leather 8 can be colored. Then, each time the carriage 52 reciprocates, the leather 8 is successively conveyed in the direction of arrow E, and the entire color is added.

When the leather 8 is colored in the ink jet ejecting section 5 described above, the leather is not originally of a fixed size, and therefore the carriage 52 is reciprocally moved in the area where ink is to be ejected. There can be various areas within that range each time. On the other hand, the ink ejection area from the inkjet head may be set in advance to the maximum ejection area for the leather 8, but with this method, the ink is ejected even on the portion outside the leather 8 and the ink is ejected. It will be wasted. In the inkjet ejection unit of FIG. 8, a leather detection unit 55 that detects the presence of leather is provided near the inkjet head 50 in order to avoid waste of this ink. By interlocking this detection output with the drive signal to the inkjet head, control is performed so as to stop the ejection of ink when the inkjet head 50 is scanning a portion deviated from the leather 8. This leather detector 55
Uses a reflective photo interrupter here. Further, as the leather detection unit 55, it is not necessary to provide a special mechanism, and other than this, a method of combining various light-emitting elements and light-receiving elements or a contact needle is used to detect the leather end by making a slight contact. , There is a method of recognizing the area where the leather 8 exists.

On the other hand, referring to FIG. 7, in parallel with the reciprocating movement of the carriage 52, on the downstream side in the conveying direction of the leather 8,
An inkjet ejecting unit 6 is provided for performing a post-process after ink coloring, that is, for ejecting a liquid image control agent. Returning to FIG. 8 again, the inkjet head 60 in which the image control agent is sprayed in the inkjet spraying section 6 is composed of one inkjet head unit in which a plurality of nozzles are arranged. The head 60 is temporarily connected to the auxiliary processing liquid storage chamber 61 that stores the image control agent, and the image control agent is supplied. An image control agent is supplied to the auxiliary processing liquid storage chamber 61 from a processing liquid supply device separately provided via a tube (not shown). Then, the leather 8 colored by the above-described inkjet ejecting unit 5 operates so as to be subsequently subjected to the post-process by the image control agent.
The inkjet head 60 and the auxiliary treatment liquid storage chamber 61 are both provided on a carriage 62, and the carriage 62 is guided along a guide rail 63 and a guide rail 64 by a signal sent to the inkjet head 60 from an electrical system (not shown). The ink jet head 60 while reciprocating in the direction of arrow D in the figure for scanning.
Then, the image control agent is ejected from all the nozzles, and the immediately following process is performed on the leather 8 immediately after the coloring. Then, the leather 8 is sequentially conveyed in the direction of arrow E every time the carriage reciprocates, and the processing immediately after the whole is performed. In this case as well, in order to detect the area where the leather 8 is present, a leather detection unit 65 made of a reflective photo interrupter is installed in the vicinity of the inkjet head 60, and the ejection control of the image control agent is performed only in the area where the leather is present. There is.

The operations of the ink jet ejecting section 4 for ejecting the liquid droplet permeation control agent and the ink jet ejecting section 7 for ejecting the finish coating agent are the same as those of the ink jet ejecting section 6, and therefore the description will be given here. Omit it.

Referring again to FIG. 7, the leather 8 is conveyed by
This example has the mechanism described below. That is, the leather 8 is provided in advance with an adsorption device 9 for adsorbing the leather from the non-colored surface by suction of air, and the adsorption device 9 moves along the rail 91 in the direction corresponding to the direction E in FIG. It has a mechanism. In order to start the coloring process, first, the leather 8 is installed in the adsorption device 9, and suction of air is started for a certain time by a driving source (not shown), and the leather 8 is lightly sucked and fixed and leveled. Then, the suction device 9 is fed in the direction of arrow E until the tip of the leather 8 reaches the inkjet head 40, and the color adding operation is started. After that, each time the carriage 42 is reciprocated once, the leather 8 installed on the suction device 9 is sequentially sent out in the direction of the arrow E by the reciprocating color width of the ink jet head 40. Then, the leather 8 is sent out at the same speed and reaches the inkjet head 50. Then, the coating process described above is sequentially performed. Similarly, when the coating on the leather 8 is completed, the suction of the leather 8 is released and the operation is completed.

By using the apparatus having such a structure, it is possible to realize a color-adding processing apparatus in which all of the pre-process, the color-adding process, the post-process, and the modifying process are continuous with respect to the leather. be able to. Further, since both the pre-process and the post-process have a relatively short time with the color-adding process, they can be respectively the process immediately before and the process immediately after the color-adding process. Further, in the case of this color-addition processing device, the leather can be easily attached, and since the transport path is also in a straight line, the transport mechanism can be simplified. Therefore, the coloring process on the leather can be automated more efficiently. In addition to these, if it is possible to freely change the installation interval between the ink jet ejecting units in this apparatus, it is possible to adjust the distance between the inkjet ejecting units for drying after finishing the coloring or modifying process including the pre-processing and post-processing. Since the time can be set arbitrarily, it is possible to further expand the application range of the composition of the ink used and various treatment liquids and the ejection amount.

(Embodiment 3) FIG. 9 shows an embodiment in which the form of Embodiment 2 is further developed, and shows an overall configuration diagram of the ink jet color processing apparatus. The inkjet ejecting unit in this example is the same as the inkjet ejecting units 4, 5, 6, 7 described in the second embodiment. In the present embodiment, the drying devices 100 and 110 are installed on the discharge side of each of the inkjet ejecting units arranged on these straight lines. Although not shown in FIG. 9, drying devices are also installed one by one on the discharge side of each of the inkjet ejecting unit 6 and the inkjet ejecting unit 7. By installing such a drying device, the leather 8 enters each drying device immediately after the color-adding process including the front-back process or the modifying process, and forces the solvent component of each jetted processing liquid. It is intended to shorten the time until the subsequent treatment. This makes it possible to shorten the time required for each process and reduce the size of the inkjet color-addition processing device as a whole.

Leather is generally not strong at high temperatures, although it depends on the kind of animal and tanning method. Therefore, the temperature of these dryers does not need to be too high. It is preferable to set the temperature to 60 ° C. or lower, which is also the temperature for general greasing. Further, at such a temperature, it may not be possible to instantaneously dry the leather. Therefore, as the inkjet color processing apparatus of FIG.
It is also possible to stop the movement of the adsorption device 9 at the stage of being transferred into 0 or 110, thereby stopping the leather 8 in the drying device 100 or 110 for a certain time, and controlling the leather 8 to be sufficiently dried. It is valid. In this case, the operation of the inkjet ejecting unit is also controlled to stop in conjunction with the stop.

(Embodiment 4) FIG. 10 shows still another embodiment of the present invention. In the ink jet color processing apparatus of FIG. 7, before the modification processing step and after the modification processing step is completed. The dryer was installed only after. In the coloring process including the pre-process and the post-process, the treatment liquid is not excessively added to the leather 8, so that the drying is not always necessary for each of these processes. Similarly, the finish coating agent in the modification treatment need not be excessively used in order to maintain the texture, which is an important characteristic of leather, so that drying is not always necessary even in this modification treatment step.

On the other hand, since the drying device 100 is installed between the end of the post-process after the addition of color and the progress of the modification treatment process, the effect of heating is exerted in this portion rather than the effect of drying the leather. Give. Thereby, the binding between the coloring material and the leather in the colored leather 8 can be further strengthened. Further, the drying device 110 is installed even after the modification treatment step is completed, so that the fixing property of the finish coating agent to the leather 8 is further improved here. With the above configuration, the deterioration of the color-added image is prevented.

By adopting the above-mentioned constitution, stable image formation and stronger image fastness can be obtained even for leather having a relatively small number of dyeing seats depending on the type of animal and the tanning method. It has become possible. In addition, the leather was easy to handle for the coloring treatment, and the coloring treatment for the leather was quick.

In the above description of the embodiments, the method for processing the entire surface of the leather in each step when performing the color processing on the leather has been described. However, the present invention is not limited to this, and at least the region to be colored on the leather may be subjected to the above-described processing steps in order. That is, when observing any area on the leather, the previous step by the droplet permeation control agent, the ink coloring step,
It suffices that the post-treatment with the image control agent and the modification treatment step are carried out in this order. Therefore, in processing one piece of leather by scanning the inkjet ejection means, the above-mentioned treatment agents are used. It is also within the scope of the present invention to arrange the ink jet ejecting means for sequentially ejecting the above in parallel, and to complete the coloring process on the entire surface of the leather while sequentially applying the treating agent in each of the above steps. .

[0097]

As described above, according to the present invention,
When image formation is performed on leather by using a droplet ejecting means as a color addition to the leather, the behavior of the droplets ejected in the coloring step in the leather is controlled by applying a droplet permeation control agent as a previous step. And, by applying an image control agent as a post-process, it is controlled to a desired state, thereby, the image formed on the leather, with higher definition and good color developability, excellent in fastness. It is possible to do.

In addition to this, among the conventional treatments for leather, attention is focused on treatments not mainly changing the physical properties of the leather itself, that is, dyeing and finish coating, and the processing procedure from the raw leather is reviewed. It has also been found that performing the finish coating in this process by using a droplet jetting means also leads to efficiency improvement in leather production. As a result, it is possible to make the modification treatment process typified by finish coating a substantially continuous process in addition to the above-described color treatment process.

Further, by combining these processing steps, it was possible to realize efficient image formation on leather and automation of finishing. In addition, the combination of processing steps has brought about the advantages of not only processing small quantities of many kinds of products, expressing multicolored and high-definition images, but also solving the problem of discarding excess processing liquid.

Therefore, it is possible to obtain a high-quality, high-quality leather product without any limitation on the conventional use of leather, without significantly increasing the production cost and wasting time. , It has become possible to develop new leather that has never existed before. These can meet the detailed demands of the market in the future.

[Brief description of drawings]

FIG. 1 is a flow chart showing a process from preparation of leather to a leather product through coloring and modifying treatment of leather in an example of the present invention.

FIG. 2 is a main configuration diagram of an inkjet ejection unit in an embodiment of the present invention.

FIG. 3 is a diagram showing a member for fixing and conveying leather in the inkjet ejection unit of FIG.

FIG. 4 is an overall configuration diagram showing an example of an inkjet color-addition processing device according to the present invention.

FIG. 5 is a schematic diagram showing the behavior of ink droplets in the leather when the ink is colored by the inkjet coloring method of the present invention.

FIG. 6 is a schematic diagram showing the behavior of droplets of the ink in the leather when the leather is colored with the ink without using the present invention.

FIG. 7 is a diagram showing a second embodiment of the inkjet color-addition processing device in the embodiment of the present invention.

FIG. 8 is a main configuration diagram of an inkjet ejection unit in the inkjet color processing apparatus of FIG.

FIG. 9 is a diagram showing a third embodiment of the inkjet color-addition processing device in the embodiment of the present invention.

FIG. 10 is a diagram showing a fourth embodiment of the inkjet color-addition processing device in the embodiment of the present invention.

[Explanation of symbols]

 1, 4, 5, 6, 7 Inkjet injection unit 2 Leather 3 Transport support member 8 Leather 9 Adsorption device 100, 110 Drying device 10, 40, 50, 60, 70 Inkjet head

Claims (18)

[Claims] 1. A leather color processing method comprising a color-adding step in which image formation is performed on leather by using a droplet jetting means as a color addition to the leather, the leather being image-formed by the droplet jetting means. As a pre-process of ink coloring by means of droplet ejection onto leather on the surface side, at least a pre-process of applying a droplet permeation control agent capable of chemically reacting with the coloring material of the ink to the leather surface region to which ink is added, A post-process of applying an image control agent that chemically reacts to at least the color material of the ink in the ink-colored leather surface region as a post-process of ink addition by means of a droplet jetting means onto the leather,
A method for color-adding leather, comprising: 2. The absolute amount per unit area of the droplet permeation control agent applied in the preceding step is smaller than the absolute amount per unit area of the image fixing agent applied in the subsequent step. The leather coloring treatment method according to claim 1. 3. The absolute amount of the droplet permeation control agent applied in the preceding step per unit area is smaller than the amount of the coloring material applied per unit area of the ink applied in the coloring step. The leather coloring treatment method according to claim 1 or 2. 4. The sum of the absolute amount per unit area of the droplet permeation control agent applied in the preceding step and the absolute amount per unit area of the image control agent applied in the subsequent step is the additive color. The leather coloration method according to any one of claims 1 to 3, wherein the amount of coloring material applied per unit area of the ink applied in the step is equal to or more than the amount. 5. The leather coloring treatment method according to claim 1, wherein the droplet permeation control agent in the previous step and the image control agent in the subsequent step are made of the same material. . 6. A color-adding step in which image formation is performed on leather by using a droplet jetting means as a color addition to the leather, and a step of applying the image to the surface of the leather by the droplet jetting means is performed on the leather. As a pre-step of ink coloring by the droplet jetting means, a step of at least applying a droplet permeation control agent capable of chemically reacting with a coloring material of the ink to a leather surface region to be ink-colored, In a subsequent step, an image control agent that chemically reacts with at least the ink coloring material in the leather surface area to which the ink is added is added, and the unit area of the droplet permeation control agent applied in the preceding step is The absolute amount per unit area of the image control agent applied in the subsequent step is larger than the absolute amount of. 7. A color-adding step for forming an image on the leather by using a droplet jetting means, and at least an ink-adding step as a post-step of adding ink by the droplet jetting means on the leather. And a post-process of applying an image control agent that chemically reacts with the coloring material of the ink in the leather surface area, the method for adding color to the leather, wherein As a pre-step of adding ink to the leather by means of a droplet jetting means, at least a droplet permeation control agent capable of chemically reacting with the coloring material of the ink is applied to the leather surface area to which the ink is added, The leather coloration processing method, wherein the absolute amount of the droplet permeation control agent applied per unit area is smaller than the absolute amount of the image control agent applied in the subsequent step. 8. A leather color-adding method having a color-adding step of performing image formation as color-adding on leather by using a droplet-jetting means for leather, wherein the color-adding step by the droplet-jetting means is performed. And at least a modification treatment step capable of substantially modifying the droplet jetting image on the leather is a substantially continuous step. 9. The leather coloring process according to claim 8, wherein the modification treatment step is a substantially continuous step of one or more modification treatments performed by using droplet ejecting means. Method. 10. The leather coloring treatment method according to claim 8, wherein the modification treatment step is a finish coating. 11. The method according to claim 8, further comprising a forced drying step between the coloring step and the modification processing step.
11. The leather coloration method according to claim 10. 12. The leather coloring processing method according to claim 8, wherein the droplet ejecting means is an ink jet system. 13. The leather, which has been subjected to a tanning process including retanning, has been subjected to neutralization, fatliquoring, water squeezing, stretching and drying, and further flattening by seasoning, staking, tensioning drying, edging, etc. 13. The leather coloring treatment method according to any one of claims 8 to 12, characterized in that the leather whose texture is finished is used. 14. The droplet jetting from the droplet jetting means,
The method for coloring leather according to any one of claims 8 to 13, which is performed on the silver surface and / or the flesh surface of the leather. 15. An apparatus for executing the leather coloration processing method according to claim 8, wherein the leather is an inkjet recording means for forming an image on the leather as a color addition to the leather. A means for imparting to the leather a modifying agent capable of substantially modifying the droplet jetting image in,
A leather color processing device characterized by being equipped with. 16. A leather characterized in that an image is formed by the leather coloration method according to any one of claims 1 to 14. 17. A leather product, which is formed by processing a leather on which an image is formed by the leather coloration processing method according to claim 1. 18. A leather color-addition processing method comprising a color-adding step of performing image formation on leather by applying a droplet jetting means to the leather, the leather being image-formed by the droplet jetting means. As a step immediately before the ink coloring by the droplet jetting means to the leather on the surface side, at least a step immediately before applying a droplet permeation control agent capable of chemically reacting with the coloring material of the ink to the leather surface area to be ink-colored A step immediately after applying an image control agent that chemically reacts to at least the color material of the ink in the ink-colored leather surface region as a step immediately after the ink coloration by the droplet jetting means onto the leather, and the droplet jetting means The color-adding method according to claim 1, which comprises, as a substantially continuous step, at least a modification treatment step capable of substantially modifying a droplet jetting image on the leather.