JP2003055886A - Method for ink jet printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for ink jet printing by which a print of good printing quality can be afforded in a simple step without selecting the kind of fabric. SOLUTION: This method for the ink jet printing comprises a pretreating step of applying a reactional solution containing a reactant to a fabric, a printing step of jetting droplets of an ink composition containing a pigment colorant to the fabric passing through the pretreating step and a heating step of heating the fabric passing through the printing step at 100-180 deg.C. The pigment colorant is colored resin particles composed of a pigment having the surface coated with a resin colored with a dye.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet textile printing method capable of providing a printed material having a good printing quality in a simple process regardless of the kind of cloth.

[0002]

2. Description of the Related Art Textile and / or image printing methods for woven fabrics, non-woven fabrics and the like made of various fibers are generally screen printing methods, roller printing methods and the like. Since these printing methods require complicated operations such as tracing and plate making for each pattern, it is difficult to reduce the cost, and it is not suitable for small-quantity multi-product production. In order to eliminate such drawbacks of conventional printing methods, read a pattern sample with an image input device such as a scanner,
A method (inkjet printing) in which image processing is performed by a computer and printing is performed on a cloth by an inkjet recording method based on the obtained image information has been proposed and put into practical use. This inkjet recording method is a recording method in which droplets of ink are ejected and the droplets are attached to a recording material to perform printing, and it is particularly advantageous because a high-quality full-color image can be easily obtained. It is widely used in the printing field where paper or the like is used as a recording material.

Fabrics to be subjected to ink-jet printing are
There are various kinds such as cotton cloth, silk cloth, nylon cloth and polyester cloth. Therefore, the inkjet printing method is required to be able to provide a printed material of good printing quality, which is free from bleeding and excellent in color developability, regardless of the type of cloth used. In response to such a request, for example, Japanese Patent Laid-Open No. 9-300
Japanese Patent Laid-Open No. 606 proposes a method of using a hot melt ink containing a wax and a colorant for inkjet printing. However, the printed material obtained by this method was insufficient in color development because the wax remained in the printed portion. In addition, this method requires a means for heating and melting the hot melt ink in addition to the means for performing ordinary ink jet recording, and thus has a problem that the process and the apparatus are complicated and the cost is increased. It was

Therefore, an object of the present invention is to perform vivid and high-density printing on any cloth without complicating the process or apparatus, increasing the cost, etc. An object of the present invention is to provide an inkjet printing method capable of providing a printed product of printing quality.

[0005]

The present invention provides an ink containing a pigment-based colorant for a pretreatment step of adhering a reaction liquid containing a reactive agent to a cloth, and the cloth which has undergone the pretreatment step. A printing step of ejecting droplets of the composition, and a heating step of heating the cloth subjected to the printing step at 100 to 180 ° C., wherein the pigment-based colorant is a resin colored with a dye The above object is achieved by providing an inkjet printing method which is a colored resin particle comprising a pigment coated with.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION First, an ink composition and a reaction liquid used in the inkjet printing method of the present invention will be described below.

The ink composition according to the present invention contains, as a pigment colorant, colored resin particles composed of a pigment whose surface is coated with a resin colored with a dye.

As the resin forming the colored resin particles, it is preferable to use a styrene-acrylic resin from the viewpoint of storage stability of the ink composition such as dispersion stability.
In particular, as the styrene-acrylic resin, styrene,
One or more monomer units selected from the group consisting of substituted styrenes and acrylates, and one or two selected from the group consisting of acrylic acid and methacrylic acid.
It is preferable to use a copolymer containing one or more monomer units.

The average molecular weight of the resin is preferably 10,000 to 10 from the viewpoint of dispersion stability of the colored resin particles.
It is 50,000.

The acid value of the resin is preferably 50 to 280 KOHmg / g from the viewpoint of dispersion stability and ejection stability of the colored resin particles.

The content ratio (resin / pigment) of the resin and the pigment in the colored resin particles is 1 / 0.5 to 20.
It is preferably / 1. If the content ratio is less than 1 / 0.5, there is concern about the dispersion stability of the colored resin particles in the ink composition, and if it exceeds 20/1, the storage stability of the ink composition decreases and nozzle clogging occurs. May be caused.

The dye constituting the colored resin particles is a dye which is generally used as a colorant in a dye ink composition for ordinary ink jet recording and is a dye which can be adsorbed by the resin. It can be used without limitation, for example, oil-soluble dyes, disperse dyes,
Direct dyes, acid dyes, basic dyes, reactive dyes and the like can be mentioned, and one or more of these can be used. Of these, it is particularly preferable to use an oil-soluble dye, because it facilitates the production of the colored resin particles that are pigments whose surface is coated with a resin colored with a dye.

As the pigment constituting the colored resin particles, the same pigments generally used as colorants in ordinary pigment ink compositions for ink jet recording can be used. For example, azo lake,
Insoluble azo pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, perylene pigments, perinone pigments, quinacridone pigments, thioindigo pigments, isoindolinone pigments, quinofuraron pigments, dioxazine pigments, anthraquinone pigments, nitro pigments, nitroso pigments, aniline black, etc. Organic pigment, titanium white, zinc white, lead white, carbon black, red iron oxide, vermilion, cadmium red, yellow lead, ultramarine,
Inorganic pigments such as cobalt blue, cobalt violet and zinc chromate can be used. Further, any pigment not listed in the color index can be used as long as it can be dispersed in the aqueous phase.

The dyes and the pigments are basically used by combining those having substantially the same hue on the cloth, but the dyes and the pigments having different hues may be used in combination. Further, as the dye, not only one type of dye but also two or more types of dyes having different color types can be used.

The total content of the dye and the pigment is preferably 1.5 to 5% by weight in the ink composition according to the present invention.
Is. The content ratio of the dye and the pigment (dye / pigment) is preferably 0.2 / 1 to 2/1 in terms of color development and ejection stability.

The colored resin particles are formed by a known microencapsulation method (phase inversion emulsification method), in which the pigment is microencapsulated simultaneously with the coloring of the resin by the dye, and the resin is colored by the dye. Then, the pigment can be microencapsulated, and the like. An example of manufacturing the colored resin particles is as follows.

<Production Example of Colored Resin Particles> The resin is dissolved in an organic solvent, the dye and the pigment are added to dissolve or disperse them, and then water or water is used as a main component. By adding the above liquid, the pigment is encapsulated in the resin colored with the dye (microencapsulation of the pigment). Then, the organic solvent is removed to obtain an intended aqueous dispersion of the colored resin particles. Water may be removed if necessary.

Examples of the organic solvent used in the production of the colored resin particles include ketone solvents such as methyl ethyl ketone and acetone; alcohol solvents such as methanol, ethanol and isopropyl alcohol; chlorine solvents such as chloroform and methylene chloride; benzene; An aromatic solvent such as toluene may be used, and one or more of these may be used.

The average particle diameter of the colored resin particles is preferably 0.5 μm or less, more preferably 0.2 μm or less from the viewpoint of dispersion stability and ejection stability in the ink composition.

The content of the colored resin particles in the ink composition according to the present invention is preferably 3 to 10% by weight.
If the content is less than 3% by weight, the print density is insufficient,
If it exceeds 10% by weight, the storage stability of the ink composition may deteriorate and the nozzle may be clogged.

The ink composition according to the present invention preferably contains a humectant from the viewpoint of improving the ejection stability from the nozzle of the ink jet head. As the moisturizing agent, the same ones as those used in this type of ink composition can be used, and for example, glycerin, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene. Glycol, polypropylene glycol, 1,3-
Propanediol, 1,4-butanediol, 1,2-
Hexanediol, 1,5-pentanediol 1,6-
Hexanediol, 1,2,6-hexanetriol,
Polyols such as pentaerythritol and derivatives thereof such as ethers and esters; lactams such as 2-pyrrolidone, N-methyl-2-pyrrolidone and ε-caprolactam; urea, thiourea, ethyleneurea, 1,3-dimethylimidazolidi Examples thereof include ureas such as non-types; sugars such as maltitol, sorbitol, gluconolactone, maltose, and the like, and one or more of these are used. The content of the moisturizer is preferably 4 to 40% by weight in the ink composition according to the present invention.

Further, the ink composition according to the present invention preferably contains an organic solvent as a penetrating agent from the viewpoint of enhancing wettability to the cloth and enhancing penetrability. As the organic solvent, those similar to those used in this type of ink composition can be used. For example, lower alcohols such as ethanol and propanol; cellosolves such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether. Carbitols such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether; ethylene glycol mono-n-butyl ether, diethylene glycol-n-
Examples thereof include glycol ethers such as butyl ether and triethylene glycol-n-butyl ether, and one or more of these may be used. The content of the organic solvent (penetrating agent) in the ink composition according to the present invention is preferably 2 to 15% by weight.

From the same viewpoint, it is preferable that the ink composition according to the present invention contains a surfactant as a penetrating agent. As the surfactant, those similar to those used in this kind of ink composition can be used. For example, fatty acid salts; anionic surfactants such as alkyl sulfate ester salts; polyoxyethylene alkyl ether, poly Nonionic surfactants such as oxyethylene alkyl phenyl ether; Surfynol 6
1, 82, 104, 440, 465, 485 (all are trade names, manufactured by Air Products and Chemicals, Inc.) and other acetylene glycol-based surfactants; cationic surfactants; zwitterionic surfactants. And the like, and one or more of these are used. The content of the surfactant (penetrating agent) in the ink composition according to the present invention is preferably 0.1 to 2% by weight.

As described above, the ink composition according to the present invention may further contain a dispersant, a humectant, and a penetrant in addition to the colored resin particles as a colorant, and water as a balance. . As the water, it is preferable to use pure water or ultrapure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, and distilled water. In particular, water obtained by sterilizing these waters by ultraviolet irradiation, addition of hydrogen peroxide, or the like is preferable because molds and bacteria are prevented from being generated for a long period of time.

The ink composition according to the present invention may further contain, if necessary, antifungal agents / preservatives, antioxidants / ultraviolet absorbers, chelating agents, oxygen absorbers, pH adjusters and the like. One or two or more kinds of various additives usually used in the composition can be contained.

The ink composition according to the present invention preferably has a surface tension of 25 to 40 mN / m, and preferably 28 to 35 mN / m, from the viewpoint of a balance between print quality and reliability as an ink for ink jet recording. More preferably, From the same viewpoint, the viscosity of the ink composition according to the present invention at 20 ° C. is preferably 1.5 to 8 mPa · s, more preferably 2 to 6 mPa · s. In order to keep the surface tension and the viscosity within the above ranges, means such as adjusting the concentration of the colored resin particles, adjusting the type of moisturizing agent, and the addition amount thereof may be used.

Further, the reaction liquid according to the present invention contains a reaction agent having a function of aggregating the ink composition. By preliminarily attaching such a reaction liquid to the cloth in the pretreatment step, the reaction agent and the ink composition come into contact with each other on the cloth in the subsequent printing step, and the reaction agent is mixed with the ink composition. Since the dispersed state of the material is destroyed to form an aggregate on the cloth, it is possible to obtain a high-quality printed material with high color density and less ink bleeding and unevenness.

As the above-mentioned reaction agent, a polyvalent metal salt is preferably used because it can destroy the dispersed and / or dissolved state of the colorant in the ink composition to cause aggregation.

As the polyvalent metal salt (reactant), it is preferable to use a water-soluble salt composed of a polyvalent metal ion having a valence of 2 or more and an anion that binds to the polyvalent metal ion. preferable. Examples of the polyvalent metal ion having a valence of 2 or more include Ca ²⁺ , Cu ²⁺ , Ni ²⁺ , Mg ²⁺ and Zn.
²⁺ , Ba ^{2+ and} other divalent metal ions; Al ³⁺ , Fe
^Examples thereof include trivalent metal ions such as ³⁺ and Cr ³⁺ . In particular, divalent or higher polyvalent metal ions are Ca ²⁺ or Mg.
^The polyvalent metal salt of ²⁺ gives favorable results from two viewpoints of the pH of the reaction solution and the quality of the printed material obtained. Further, as anions, Cl ⁻ , NO ₃ ⁻ ,
I ⁻ , Br ⁻ , ClO ₃ ⁻ , CH ₃ COO ^{− and the} like can be mentioned. Particularly, it is preferably nitrate ion (NO ₃ ⁻ ) or carboxylate ion (CH ₃ COO ⁻ ).

The carboxylate ion has 1 carbon atom.
Those derived from one or two or more carboxylic acids selected from the group consisting of saturated aliphatic monocarboxylic acids having 6 to 6 and carbocyclic monocarboxylic acids having 6 to 10 carbon atoms are preferable. Preferred examples of the saturated aliphatic monocarboxylic acid having 1 to 6 carbon atoms include formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, bivalic acid and hexanoic acid. Formic acid and acetic acid are particularly preferable. The carbon number 1 to
The hydrogen atom on the saturated aliphatic hydrocarbon group of the saturated aliphatic monocarboxylic acid of 6 may be substituted with a hydroxyl group, and a preferable example of such a carboxylic acid is lactic acid. Further, preferred examples of the carbocyclic monocarboxylic acid having 6 to 10 carbon atoms include benzoic acid and naphthoic acid, and more preferred is benzoic acid.

The content of the polyvalent metal salt may be appropriately determined within a range in which the printing quality and the effect of preventing clogging can be obtained, but it is preferably about 0.1 to 40% by weight in the reaction solution. Yes, and more preferably about 5 to 25% by weight.

The reaction liquid contains water together with the reaction agent. As the water, the same water as used in the ink composition can be used. In addition to water, the reaction liquid preferably contains a moisturizer or a penetrant for the purpose of moisturizing, adjusting penetration, adjusting viscosity, and the like. As the moisturizing agent and penetrating agent, the same ones as those used in the ink composition can be used with the same content. Further, the reaction solution may contain, if necessary, one or two of various additives usually used in ink jet recording inks, such as antifungal agents / preservatives, pH adjusters, and dissolution aids.
It is also possible to contain more than one species.

The physical properties such as surface tension and viscosity of the reaction liquid are preferably adjusted in the same manner as in the ink composition.

Next, the ink-jet printing method of the present invention will be described based on its preferred embodiments. The inkjet printing method of the present embodiment includes a pretreatment step of adhering the reaction liquid to a cloth, a printing step of discharging droplets of the ink composition onto the cloth that has undergone the pretreatment step, A washing step of washing the cloth that has been subjected to the printing step with water;
And a heating step of heating the cloth that has been subjected to the water washing step at 100 to 180 ° C.

In the pretreatment step, the reaction solution may be attached to the cloth by immersing the cloth in the reaction solution, coating the reaction solution with a brush or a coating device, and reacting the reaction solution. A known method for attaching a liquid material to a cloth, such as a method of forming an aerosol and spraying it with a spray, can be appropriately used. It is also possible to use a recording head of an inkjet printer to eject droplets of the reaction liquid onto the cloth from the nozzles and attach the droplets to the cloth. In this way, when the inkjet method is adopted as a method for attaching the reaction liquid to the cloth, the pretreatment step and the printing step described later can be performed using the same inkjet printer, and the nozzle arrangement is further devised. By doing so, it is possible to perform both processes in one pass, so that workability and the process can be further simplified. Further, when the reaction liquid is attached to the cloth by using the inkjet method, the reaction liquid can be selectively ejected and attached only to the place where the ink composition is attached, so that the consumption amount of the reaction liquid can be minimized. It is economical because it can be suppressed to.

The printing step is a step in which droplets of the ink composition are ejected onto the cloth that has been subjected to the pretreatment step and the droplets are attached to the cloth, which is similar to ordinary ink jet printing. In addition, it is performed by an inkjet method using a known inkjet printer. The type (model) of the inkjet printer is not particularly limited,
It is preferable to use a drop-on-demand type inkjet printer. The drop-on-demand type inkjet printer adopts a piezoelectric element recording method that performs recording by using a piezoelectric element arranged in a recording head, and heat energy generated by a heater of a heating resistance element arranged in the recording head. Although there is a thermal jet recording method that performs recording by using, etc., any recording method may be used.

The washing step is a step of washing the cloth that has been subjected to the printing step with water. This washing step is not an essential step in the inkjet printing method of the present invention, but it is preferable to wash the cloth because it can remove the unreacted reaction agent that causes the deterioration of the texture of the cloth. . Also, by performing this water washing step,
It can also be expected to improve the fixing property of the colored resin particles to the cloth,
It is possible to provide a high-quality printed matter having more excellent color developability.

In the heating step, which is the final step in the ink jet recording method of the present embodiment, the printed cloth is
It is a step of heating and drying at 00 to 180 ° C. This heating step is a step for improving the fixability of the colored resin particles, which are the colorant, to the cloth, and imparting sufficient washing fastness and abrasion resistance to the printed material. The heating of the cloth can be performed by appropriately using a known heating means such as an iron, a dryer, and a dryer.

The printed material obtained by the ink jet printing method according to the present embodiment, which comprises the above steps, is free from ink bleeding and the like, and the printed portion is clear and has a high color density, and is of high quality with excellent color developability. It is a printed material and has excellent abrasion resistance and wash fastness.

The present invention can be modified in various ways without departing from the spirit thereof. The inkjet printing method of the present invention comprises a pretreatment step of adhering a reaction liquid containing a reactive agent to a cloth, and a droplet of an ink composition containing a pigment-based colorant for the cloth subjected to the pretreatment step. And a heating step of heating the cloth subjected to the printing step at 100 to 180 ° C., and the pigment-based colorant is a pigment whose surface is coated with a resin colored with a dye. The colored resin particles may be any of the above, and the method of attaching the reaction liquid to the cloth in the pretreatment step, the type and number of the ink composition used in the printing step, the method of heating the cloth in the heating step, and the like are not particularly limited. Further, after the heating step, the cloth may be washed with water and dried in the same manner as in ordinary inkjet printing. If necessary, a soaping process (a process of washing off unfixed colorant with a hot soap solution or the like) may be performed.

[0041]

The present invention will be described in more detail below with reference to examples of the present invention, but the present invention is not limited to these examples.

Example An ink composition (four colors of black, yellow, magenta and cyan) having the composition shown in [Table 1] below was prepared according to the following <Preparation of ink composition>. A reaction solution having the composition shown in [Table 1] below was also prepared.

<Preparation of Ink Composition> 4 parts of oil-soluble dye,
Methyl ethyl ketone 60 parts, isopropyl alcohol 1
6 parts and 20 parts of styrene-acrylic resin were mixed and stirred to obtain a resin solution. 50 parts of this resin solution and 5 parts of pigment were mixed and dispersed with a bead mill using glass beads to obtain a dispersion. And to 55 parts of this dispersion liquid,
After 45 parts of pure water was added dropwise at a rate of 5 ml / min, methyl ethyl ketone and isopropyl alcohol were distilled off using a rotary evaporator to obtain an aqueous dispersion of colored resin particles. A predetermined amount of an ink component other than the colorant and resin shown in [Table 1] below was added to the aqueous dispersion of the colored resin particles thus obtained, and the mixture was stirred to prepare an ink composition.

[0044]

[Table 1]

<Preparation of printed material 1> An ink jet printer (trade name "PM5000C", manufactured by Seiko Epson Corp.) was used in a conventional manner, and the ink composition of four colors and the reaction liquid were applied to the cloth. Then, the reaction liquid and the ink composition were sequentially discharged and attached by an inkjet method to obtain a printed fabric. As the cloth, five kinds of nylon taffeta cloth, cotton cloth, silk cloth, polyester cloth and wool muslin cloth were used. Each of these five types of printed fabrics was used to make 1
After heating at 35 ° C. for 5 minutes, it was washed with water and dried with an iron to obtain a printed material 1. The five types of printed materials 1 thus obtained were all high-quality printed materials having no ink bleeding, a clear printed portion, a high color density, and excellent color developability.

<Preparation of Printed Fabric 2> Further, before heating the printed fabric, the printed fabric was washed with water to remove excess unreacted reactant, and A printed matter 2 was obtained in the same manner as in Preparation. The five kinds of printed materials 2 thus obtained all have good printing quality as the printed material 1, and in addition to having a good texture,
The printed material had a good feel to the skin.

[0047]

EFFECT OF THE INVENTION The ink jet printing method of the present invention can provide a printed material of good printing quality in a simple process regardless of the kind of cloth.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4H057 AA02 CA03 CB02 DA01 DA34                       FA17 GA06 GA21 HA01 HA05                       JA10 JB03                 4J039 AD03 AD09 BC75 BD02 BE01                       BE02 BE07 BE12 BE22 BE33                       FA03 GA24

Claims (17)

[Claims] 1. A pretreatment step of adhering a reaction liquid containing a reaction agent onto a cloth, and a droplet of an ink composition containing a pigment-based colorant is discharged onto the cloth subjected to the pretreatment step. The printing process and the cloth subjected to the printing process are 100-
And a heating step of heating at 180 ° C., wherein the pigment-based colorant is a colored resin particle composed of a pigment whose surface is coated with a resin colored with a dye. 2. Between the printing step and the heating step,
The inkjet printing method according to claim 1, further comprising a water washing step of washing the cloth with water. 3. The reactive agent is a polyvalent metal salt.
Or the inkjet printing method described in 2. 4. The inkjet printing method according to claim 1, wherein the resin is a styrene-acrylic resin. 5. The acid value of the resin is 50 to 280 KOHm.
The inkjet printing method according to claim 1, wherein the inkjet printing method is g / g, and the average molecular weight is 10,000 to 50,000. 6. The inkjet printing method according to claim 1, wherein the pretreatment step is performed by discharging droplets of the reaction liquid onto the cloth by an inkjet method. 7. The dye according to claim 1, which is an oil-soluble dye.
6. The inkjet printing method according to any one of 6 above. 8. A pigment-based colorant used in the inkjet printing method according to any one of claims 1 to 7, which is a colored resin particle comprising a pigment whose surface is coated with a resin colored with a dye. 9. The colored resin particles according to claim 8, wherein the resin is a styrene-acrylic resin. 10. The acid value of the resin is 50 to 280 KOH.
mg / g, average molecular weight 10,000 to 50,000
The colored resin particle according to claim 8 or 9. 11. The dye according to claim 8, which is an oil-soluble dye.
10. The colored resin particles according to any one of 10 to 10. 12. An ink composition used in the inkjet printing method according to claim 1.
An ink composition containing 3 to 10% by weight of colored resin particles consisting of a pigment whose surface is coated with a resin colored with a dye. 13. The ink composition according to claim 12, further comprising a moisturizing agent and a penetrating agent. 14. The ink composition according to claim 13, wherein the humectant is contained in an amount of 4 to 40% by weight, and the penetrant contains an organic solvent in an amount of 2 to 15% by weight and a surfactant in an amount of 0.1 to 2% by weight. object. 15. A reaction solution for use in the inkjet printing method according to claim 1, which contains a reaction agent, a humectant and a penetrant. 16. The reaction solution according to claim 15, which contains 4 to 40% by weight of the humectant, and 2 to 15% by weight of an organic solvent and 0.1 to 2% by weight of a surfactant as the penetrant. . 17. A printed article printed by the inkjet printing method according to claim 1.