JP2020138439A - Method for producing decorative article and ink set - Google Patents

Abstract

To provide a method for producing a decorative article that gives a decorative article that is of metallic tone and rich in color variation, in a small number of steps and at low cost, and an ink set.SOLUTION: A method for producing a decorative article: has a pretreatment step of attaching a pretreatment liquid to the surface of a base material, the pretreatment liquid containing water, flat particles, and cationic water-dispersible resin and having a charge density of 50 μeq/g or more; and after the pretreatment step, a step of applying inkjet printing to the surface of the base material, using water and aqueous inkjet ink containing anionic particles.SELECTED DRAWING: None

Description

Embodiments of the present invention relate to a method for producing a decorative object and an ink set.

Conventionally, in order to obtain metallic ornaments with abundant color variations, a combination of foil stamps with different shades such as gold and silver, painting with multiple color paints containing metallic pigments, or metallic pigments A method is used in which inks of a plurality of colors containing the ink are printed by printing using a plate such as a screen.

However, with these methods, when the number of metallic tones increases, the number of work processes increases, the cost increases, and mass productivity is inferior. Also, if you draw a color ink with an inkjet on a silver paint or foil applied to the surface of the base material or a resin in which a metallic pigment is kneaded into the base material, an image rich in metallic color variations will be obtained. However, there is a problem that the inkjet ink bleeds and the image quality is inferior.

Therefore, as Patent Document 1, a reaction in which a first ink containing flat metal particles having an average aspect ratio of 3 or more and 100 or less and a resin having a specific group is applied to a base material and further reacts with the specific group. A method of applying a second ink containing a compound having a sex group has been proposed.

JP-A-2018-13084

However, in Patent Document 1, the flat particles tend to be arranged so as to adhere to the surface of the base material due to their shape, and when the resin component is water-soluble, the resin component is inside the base material for the penetrating base material. There is a problem that the flat particles permeate and cover the plate-like particles, the reaction with the second ink does not work sufficiently, and the image tends to bleed.

Therefore, one object of the present invention is to provide a method for producing a metallic-like ornament that is rich in color variation and suppresses bleeding with a small number of steps.

One embodiment of the present invention includes a pretreatment step of adhering a pretreatment liquid containing water, flat particles, and a cationic water-dispersible resin and having a charge density of 50 μeq / g or more to the surface of a substrate, and a pretreatment step. The present invention relates to a method for producing a decorative object, which comprises, after the pretreatment step, a step of inkjet printing on the surface of a base material using a water-based inkjet ink containing water and anionic particles.
Another embodiment of the present invention is an aqueous inkjet ink containing water, flat particles, and a cationic water-dispersible resin, a pretreatment liquid having a charge density of 50 μeq / g or more, and water, anionic particles. With respect to ink sets, including.

According to the embodiment of the present invention, it is possible to provide a method for producing a metallic-like decorative object in which bleeding is suppressed.

Hereinafter, embodiments of the present invention will be described in detail, but it goes without saying that the present invention is not limited to these embodiments, and various modifications and changes may be made. Further, in the following description, the water-based inkjet ink may be simply referred to as "ink". Further, the particles shall include both liquid particles and solid particles.

The method for producing a decorative object according to the embodiment of the present invention comprises adhering a pretreatment liquid containing water, flat particles, and a cationic water-dispersible resin and having a charge density of 50 μeq / g or more to the surface of a base material. A method for producing a decorative object, which comprises a pretreatment step and, after the pretreatment step, a step of inkjet printing on the surface of a base material using a water-based inkjet ink containing water and anionic particles. Is.

By this method of manufacturing a decorative object, it is possible to produce a metallic-like decorative object in which bleeding is suppressed.
By including the flat particles in the pretreatment liquid, it is possible to give a metallic feeling. Further, by containing the cationic water-dispersible resin, it is possible to obtain an image with less bleeding by reacting with the ink containing anionic particles to aggregate the ink components. Since the cationic resin contained in the pretreatment liquid has a particle shape, even when the flat particles are arranged on the surface of the base material, the cationic resin component is easily exposed on the flat particles and the bleeding of the image is suppressed. It is possible to achieve both a metallic feel and a metallic feel. Moreover, unlike the water-soluble resin, the cationic water-dispersible resin does not dissolve in water once the solvent has volatilized, so that the water resistance of the printed matter is also improved. Further, when the charge density of the pretreatment liquid is 50 μeq / g or more, bleeding is sufficiently suppressed and the image quality of the decorative object can be improved.

<Pretreatment liquid>
As used herein, the term "pretreatment" means that the pretreatment liquid is adhered to the substrate by any means such as coating. Further, the attachment portion may include not only the surface of the base material but also the inside (inner surface).
The pretreatment liquid of the present embodiment is particularly preferably used as a pretreatment liquid before forming a printed image with a water-based inkjet ink.

The pretreatment liquid preferably contains flat particles.
By using the flat particles, it is easy to increase the glossiness of the image obtained by printing after the pretreatment and improve the color development property.
Further, the flat particles easily enter the concave and convex recesses on the surface of the base material and stay on the surface of the base material. The flat particles that remain on the surface of the base material exert a sealing effect on the ink used in the subsequent printing, and the flat particles are arranged parallel to the surface of the base material with a certain probability to be metallic in the image. It is considered that the feeling can be increased and the color development can be improved.

Flat particles are short in at least one direction when an orthogonal three-dimensional coordinate system is applied to the three-dimensional shape of the particles.
Examples of the flat particles include those having a thin and flat shape such as flakes, scales, plates, and flakes. The shape of the flat particles when viewed from one direction is not particularly limited, and may be a polygon such as a circle, an ellipse, a square or a hexagon, or a random (amorphous) shape. You may. Further, the flat particles may have irregularities on the surface.

The type of flat particles is not particularly limited, and may be, for example, inorganic particles, organic particles, or organic / inorganic composite particles. For example, on the surface of these particles, an inorganic substance such as a metal or a metal oxide, a resin, or the like may be used. You may use the thing coated with the organic substance of.
Specific examples of the inorganic particles include inorganic flat particles such as metal or metal oxide such as glass (for example, silica (SiO2) glass), aluminum, mica (mica), and titanium oxide. Specific examples of the organic particles include organic flat particles such as resin and cellulose produced by a manufacturing method such as pulverization. Among these, inorganic particles are preferable from the viewpoint of mass productivity, cost, and availability.

As the flat particles, for example, particles obtained by coating the surface of particles such as inorganic particles with an inorganic substance such as a metal or a metal oxide or an organic substance such as a resin may be used. Such particles are, for example, those in which the surface of the particles is coated with a metal oxide or the like to further improve the brilliance by utilizing the interference color, or the reflectance of a specific wavelength is increased to add color. It may be.

In order to increase the gloss and reflectance, for example, flat particles made of titanium oxide having a high refractive index or particles surface-coated with titanium oxide can be preferably used. Examples of the particles surface-coated with titanium oxide include particles in which the surface of inorganic particles is coated with titanium oxide. Specific examples of this include particles whose surface is coated with titanium oxide (for example, Iriodin 100 series manufactured by Merck Performance Materials Co., Ltd.) and particles whose surface is coated with titanium oxide (for example, Nippon Sheet Glass Co., Ltd.). Company-made Metashine) and the like. Among these, if coloring is required, for example, a thin film such as titanium oxide is provided on the silica flat particles with a constant thickness such as half of a specific wavelength for which the reflectance is desired to be increased, and interference is caused. Particles using a structural color (for example, Metashine manufactured by Nippon Plate Glass Co., Ltd.) can be preferably used.

The average major axis of the flat particles is the median value obtained by determining the major axis for each of the 20 particles arbitrarily selected in the scanning electron microscope (SEM) photograph. The major axis of the particle is the maximum length of the particle observed by SEM.

If the average major axis of the flat particles is 1 μm or more from the viewpoint of color development and gloss, a metallic feeling can be obtained, but it is difficult to obtain a metallic feeling on a base material having irregularities such as paper. If it is 3 μm or more, it is preferable that it is arranged in parallel even on a base material having irregularities such as paper, and it is easy to obtain a metallic feeling. Further, 6 μm or more is preferable, and 12 μm or more is more preferable. When the average major axis is 1 μm or more, the flat particles easily enter the uneven recesses on the surface of the base material and easily remain on the surface of the base material, so that they can easily exert a sealing effect on the ink used for subsequent printing. Further, since the particles are likely to be arranged parallel to the surface of the base material with a certain probability, it is easy to improve the gloss of the image and also to improve the color development.
The average major axis of the flat particles is preferably 100 μm or less, more preferably 50 μm or less, from the viewpoint of coating the pretreatment liquid.

The average thickness of the flat particles is preferably shorter than the average major axis. The average thickness of the flat particles is preferably 10 nm or more, and may be 100 nm or more, from the viewpoint of image gloss and color development and storage stability of the pretreatment liquid. The thickness of the flat particles is preferably 2 μm or less, more preferably 1 μm or less, still more preferably 0.5 μm or less, from the viewpoint of image gloss and color development and storage stability of the pretreatment liquid. The thickness of the flat particles may be, for example, 10 nm or more and 0.5 μm or less.
The average thickness of the flat particles is preferably one-fourth or less of the major axis in more than half of the particles observed in the SEM photograph, and more preferably one-tenth or less. It is preferably 1/20 or less, and more preferably 1/20 or less.
The average thickness of the flat particles is the median value of the thickness of each of 20 arbitrarily selected particles. The thickness of the flat particles is the length in the axial direction which is the minimum length among the axes orthogonal to the X-axis direction when the direction of the straight line which is the major axis of the particles is the X-axis direction.

Of the particles observed in the SEM photograph, the flat particles preferably have a width of one-fifth or more of the major axis, more preferably one-third or more, and two-half of the particles observed in the SEM photograph. It is more preferably 1 or more. The width and major axis of the particles may be the same length.
The width of the particle is the length in the Z-axis direction when the direction of the straight line which is the major axis of the particle is the X-axis direction and the direction of the straight line which is the thickness of the particle is the Y-axis direction.

One type of flat particles may be used alone, or a plurality of types may be used in combination.
From the viewpoint of color development, the content of the flat particles in the pretreatment liquid is preferably 0.1% by mass or more, more preferably 1% by mass or more, and further preferably 3% by mass or more, based on the total amount of the pretreatment liquid. preferable. The content of the flat particles in the pretreatment liquid is preferably 30% by mass or less, more preferably 25% by mass or less, based on the total amount of the pretreatment liquid, from the viewpoint of stability and coatability of the pretreatment liquid. ..

The pretreatment liquid preferably contains an agglomerating component in order to prevent unnecessary spreading and bleeding of the ink. Inks generally contain components whose surface charge is anionic, and color materials such as pigments are also generally anionic. Therefore, by adhering the cationic component to the surface of the base material in advance using a pretreatment liquid containing the cationic component, an anion-cationic reaction occurs between the ink and the ink component such as a coloring material. It is possible to sufficiently suppress the penetration of the ink into the base material, retain the coloring material on the surface of the base material, and obtain a clear image without bleeding. The cationic component is preferably a water-dispersible resin and water-dispersible resin particles.

Since the cationic resin contained in the pretreatment liquid is not water-soluble but a dispersion, even when the flat particles are arranged on the surface of the base material, the cationic resin component is easily exposed on the flat particles. It is possible to suppress image bleeding and achieve a metallic feel at the same time. Moreover, unlike the water-soluble resin, the cationic water-dispersible resin does not dissolve in water once the solvent has volatilized, so that the water resistance of the printed matter can be improved.

The cationic water-dispersible resin is a positively charged dispersible resin in which the surface of the dispersible resin is positively charged, and is dispersed in particles without being dissolved in water, and is an oil in water (O / W). ) Type emulsion can be formed. Like the self-emulsifying resin, the cationic functional group of the resin may be present on the surface of the particles, or the surface of the dispersible resin may be surface-treated by attaching a cationic dispersant or the like. The cationic functional group is typically a primary, secondary or tertiary amino group, a pyridine group, an imidazole group, a benzimidazole group, a triazole group, a benzotriazole group, a pyrazole group, a benzopyrazole group and the like. The cationic dispersant is a primary, secondary, tertiary or quaternary amino group-containing acrylic resin, polyethyleneimine, a cationic polyvinyl alcohol resin, a cationic water-soluble polybranched polyesteramide resin, or the like.

The water-dispersible resin can be blended as an oil-in-water type resin emulsion in the production of the pretreatment liquid. Typically, ethylene-vinyl chloride copolymer resin, (meth) acrylic resin, styrene-maleic anhydride copolymer resin, urethane resin, vinyl acetate- (meth) acrylic copolymer resin, vinyl acetate-ethylene copolymer weight. Examples thereof include coalesced resins and resin emulsions thereof. Here, "(meth) acrylic resin" refers to both acrylic resin and methacrylic resin.
These resins may be used alone or in combination of two or more. As will be described later, a resin emulsion in which these resins are combined may be used. As described above, a cationic functional group can be introduced into these resins, or the surface can be surface-treated with a cationic dispersant or the like to give a positive surface charge.

The average particle size of the water-dispersible resin is a volume-based particle size value (median diameter) in the particle size distribution measured by the dynamic light scattering method. As a dynamic light scattering type particle size distribution measuring device, a nanoparticle analyzer nano Partica SZ-100 (manufactured by HORIBA, Ltd.) or the like is used so that the concentration of the water-dispersible resin is 0.5% by mass. It can be diluted with and measured at 25 ° C.

In the pretreatment liquid or the ink described later, the water-dispersible resin may be present in the state of independent fine particles or in the state of aggregates in which independent fine particles are aggregated. The median diameter measured by the light scattering method is defined as the "average particle size". The average particle size of the water-dispersible resin can be measured in the state of the raw material emulsion before preparing the pretreatment liquid or ink, because in the case of ink, the influence of the coloring material (pigment particles) can be eliminated. Preferably, the measured value can be the average particle size of the present embodiment.

As the water-dispersible resin, for example, a resin having an anionic functional group represented by a carboxy group, a sulfo group or the like and a resin having a cationic functional group represented by an amino group or an amide group are combined. It is also preferable to use composite organic particles having a core-shell structure, wherein the core portion is an anionic resin and the shell portion is a cationic resin.

Examples of the anionic resin of the composite organic particles include a resin containing (meth) acrylic acid as a repeating unit, and more specifically, a styrene- (meth) acrylic acid copolymer. Other than styrene and (meth) acrylic acid, vinyl compounds copolymerizable with these may be contained.
The cationic resin (basic resin) of the composite organic particles is, for example, a resin containing a nitrogen-containing monomer, and is a nitrogen heterocycle such as N-vinylpyrrolidone, N-vinylcaprolactam, N-vinyloxazolidone, and N-vinylimidazole. Examples thereof include homopolymers or copolymers containing a compound as a repeating unit. As the comonomer forming the copolymer, for example, one or more general vinyl compounds such as styrene, (meth) acrylic acid ester, vinyl acetate, and acrylamide can be selected and used.

In this case, the ratio of the anionic resin to the cationic resin used is preferably 3 to 10 in terms of mass ratio with respect to the anionic resin 1 in order to make the charge on the particle surface cationic. .. By increasing this ratio, the amount of cationic groups of the resin particles can be increased, and the charge density of the liquid can be increased.
As commercially available products of such composite organic particles, "PP-15" and "PP-17" (both manufactured by Meisei Chemical Works, Ltd.) can be preferably used.

Examples of commercially available products of the cationic water-dispersible resin include Polysol AE-803 (manufactured by Showa Denko Co., Ltd.), which is a cationic acrylic resin emulsion, and Samplex PUE-C200B (stock), which is a cationic water-based urethane resin emulsion. Company Murayama Chemical Research Institute).

The amount of the water-dispersible resin in the pretreatment liquid is preferably 1% by mass or more, more preferably 3% by mass or more, and 5% by mass from the viewpoint of ink fixability on the surface of the base material when treated. It is more preferably% or more. On the other hand, if the viscosity of the treatment liquid is too high, uniform treatment becomes difficult, so the amount of resin is preferably 50% by mass or less, and more preferably 30% by mass or less.

In order to obtain a clear image without bleeding, it is necessary that the pretreatment liquid has sufficiently strong cationic properties. The strength of the cationic property can be known by measuring the charge density. The charge density is preferably 50 μeq / g or more, more preferably 100 μeq / g or more, and even more preferably 180 μeq / g or more.
Here, the charge density is the charge density measured according to the flow potential method. The charge density of the pretreatment liquid is the amount of charge per active ingredient in the pretreatment liquid (unit: μeq / g). The amount of the active ingredient is the total amount of the non-volatile content or the solid content contained in the pretreatment liquid, and is mainly the amount obtained by removing the solvent from the pretreatment liquid. When the water-dispersible resin contains a solvent, the amount of these solvents is also removed to determine the amount of the active ingredient.
Specifically, the pretreatment solution is diluted 100-fold with water, and the reaction end point at which the flow potential of the pretreatment solution becomes 0 V is measured while titrating the diluted pretreatment solution with an N / 400 PVSK solution. The total charge amount of the dilution pretreatment solution can be obtained from the amount of N / 400 PVSK solution used up to the end point of the reaction. The value obtained by dividing the total charge amount of the dilution pretreatment solution by the amount of the active ingredient contained in the dilution pretreatment solution is the charge density (μeq / g) of the pretreatment solution.
As the charge density measuring device, for example, a colloidal particle charge meter (“Model CAS” manufactured by AFG ANALYTIC GmbH) or the like can be used.

The method for adjusting the charge density of the pretreatment liquid is not particularly limited, but for example, the amount of the cationic group of the cationic particle in the pretreatment liquid is increased, the amount of counterion of the cationic particle is increased, and the particle having the cationic group is increased. The charge density can be increased by increasing the amount of the particles added. These methods may be a combination of several methods.
As a method for increasing the amount of cationic groups in the cationic particles, it is possible to use a resin having many cationic functional groups as the water-dispersible resin and to increase the ratio of the cationic resin in the composite resin particles as described above. Be done. As a method for increasing the amount of counter ions in the cationic particles, for example, addition of a dispersion aid such as a cationic dispersant can be mentioned. It is possible to increase the charge density of the pretreatment liquid by increasing the amount of particles having a cationic group added, but in the case of particles such as general water-dispersible resin, the charge density is set to 50 μeq / g or more. Since it is necessary to add a considerable amount of particles to the pretreatment liquid, it is preferable to adjust the charge density by increasing the amount of cationic groups of the particles.

Since the charge density of the pretreatment liquid does not depend on the acid value of the resin to be added or the pH of the entire pretreatment liquid, the acid value and pH of the resin added to the pretreatment liquid are different. , There is no big difference in the charge density of the pretreatment liquid.
In addition, the charge density is a value measured by titrating the amount of cations present in excess in the liquid with an anion-regulated liquid as compared with anions, and is different from the electric conductivity which is approximately proportional to the total amount of anions and cations. .. For example, an aqueous sodium chloride solution has a higher electrical conductivity than pure water, but has a charge density of zero like pure water. In addition, during titration, the charge density continues to decrease, and the measurement ends at the point where it becomes zero (isoelectric point), but the conductivity continues to increase during that time.

The solvent of the pretreatment liquid is preferably composed mostly of water, but may contain a water-soluble organic solvent in addition to water, if necessary. As the water-soluble organic solvent, an organic compound that is liquid at room temperature and is soluble in water can be used, and it is preferable to use a water-soluble organic solvent that is uniformly mixed with the same volume of water at 1 atm and 20 ° C. ..
For example, lower alcohols such as methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, 2-methyl-2-propanol;
Glycos such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol;
Glycerins such as glycerin, diglycerin, triglycerin and polyglycerin; acetins such as monoacetin and diacetin;
Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, triethylene glycol monomethyl ether , Triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether and other glycol ethers;
Triethanolamine, 1-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, β-thiodiglycol, sulfolane and the like can be used. The boiling point of the water-soluble organic solvent is preferably 100 ° C. or higher, more preferably 150 ° C. or higher.

These water-soluble organic solvents may be used alone or in combination of two or more as long as they form a single phase with water.
The content of the water-soluble organic solvent is preferably 30% by mass or less (or 50% by mass or less in the solvent) in the treatment liquid from the viewpoint of viscosity adjustment and moisturizing effect.

The pretreatment liquid preferably further contains a surfactant in order to reduce its surface tension so that it can be uniformly applied to the surface of the substrate.

Surfactants are roughly classified into those having an ionic (cationic / anionic / zwitterionic) and nonionic (nonionic) hydrophilic portions. In the present embodiment, the surfactant is nonionic or cationic. It is preferable to use a sex surfactant. From the viewpoint of foaming of the pretreatment liquid, it is more preferable to use a nonionic surfactant that does not easily foam. Further, either a low molecular weight type or a high molecular weight type (generally, one having a molecular weight of about 2000 or more) may be used, but it is preferable to use a high molecular weight type surfactant. The HLB value is preferably about 5 to 20 surfactants.

Examples of the nonionic surfactant include ester-type surfactants such as glycerin fatty acid ester and fatty acid sorbitan ester, and ether-type surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, and polyoxypropylene alkyl ether. , Ether ester type such as polyoxyethylene sorbitan fatty acid ester and the like. As the cationic activator, a quaternary ammonium salt, a dimethylaminopropylamide stearate, an alkylamine salt and the like can be used.

In this embodiment, an acetylene glycol-based surfactant and a silicone-based surfactant can be preferably used. Commercially available products of acetylene glycol-based surfactants include surfinol 104E and 104H, which are acetylene glycols, surfinol 420, 440, 465, and 485, which have a structure in which ethylene oxide is added to acetylene glycol, and acetylene glycols Orfin E-1004, E. -1010, E-1020, EXP. 4001, EXP. 4200, EXP. 4123, EXP. Examples thereof include 4300 and the like (Nisshin Chemical Industry Co., Ltd.), acetylenol E00 and E00P of acetylene glycol, and acetylenol E40 and E100 and the like (Kawaken Fine Chemical Co., Ltd.) having a structure in which ethylene oxide of acetylene glycol is added.

Since the silicone-based surfactant has a very high surface tension lowering ability and contact angle lowering ability, the treatment liquid can be rapidly diffused on the base material surface even if the base material surface is not hydrophilic. As a result, the functional expression component of the treatment liquid can be uniformly fixed on the surface of the base material, so that the ink is uniformly fixed on the treatment portion at the time of printing, and a high-colored and high-quality printed image can be obtained. it can. Among the silicone-based surfactants, a polyether-modified silicone-based surfactant, an alkyl-aralkyl co-modified silicone-based surfactant, and an acrylic silicone-based surfactant are preferable. As a commercially available product, "Silface SAG series" (Nissin Chemical Industry Co., Ltd.) can be preferably used. In terms of cationic properties, Katiogen series manufactured by Dai-ichi Kogyo Seiyaku, Kao's coatamine series, acetamine series and the like can be preferably used.

As the surfactant, the above-mentioned silicone-based surfactant or the like may be used alone, or a plurality of surfactants having good compatibility with each other may be used in combination.
When a surfactant is used, the content in the pretreatment liquid is preferably about 0.1% by mass or more, more preferably 0.3% by mass or more, and more preferably 0.5% by mass or more. On the other hand, the amount of the surfactant is preferably about 5% by mass or less, more preferably 4% by mass or less, and may be 3% by mass or less.

The pretreatment liquid preferably contains water. Water functions as a solvent for the pretreatment liquid, that is, a vehicle. Water is harmless, highly safe, and does not have the problems of VOCs, so the pretreated substrate can be environmentally friendly.

The water is not particularly limited, and examples thereof include ion-exchanged water, distilled water, ultrapure water, and deionized water.
The content of water in the pretreatment liquid is preferably 15% by mass or more, more preferably 40% by mass or more, and for example, 50% by mass or more, or 60% by mass or more, based on the total amount of the treatment liquid. Good.
The upper limit of the blending amount of water is not particularly limited, but for example, the content of water may be 95% by mass or less.

In addition to the above components, other components can be added to the pretreatment solution as long as the functions of the pretreatment solution are not impaired. Examples of other components include fixing improvers (nonion, cationic resin, etc.), antifoaming agents, pH adjusters, antioxidants, preservatives, and the like.

The method for producing the pretreatment liquid is not particularly limited, and the pretreatment liquid can be appropriately produced by a usual method. For example, it can be produced by putting water, flat particles, and other components into a stirrer such as a three-one motor all at once or by dividing and mixing them. Further, if necessary, a known disperser such as a bead mill may be used.

<Ink set>
An ink set according to an embodiment of the present invention includes the above-mentioned pretreatment liquid and an aqueous inkjet ink containing water and anionic particles.
When the ink set of the present embodiment is used, the flat particles adhering to the base material can suppress or reduce the penetration of the ink into the base material by pre-treating the surface with the above-mentioned pretreatment liquid. Further, the interaction between the cationic water-dispersible resin on the flat particles and the anionic particles in the ink causes the ink to aggregate, and it is possible to form a highly colored image in which bleeding is suppressed. The pretreatment liquid is as described above.
Hereinafter, the water-based inkjet ink will be described.

The ink preferably contains anionic particles. Examples of the anionic particles in the ink include anionic coloring materials and resins whose surface is negatively charged and charged negatively.

As the coloring material, either a pigment or a dye can be used, and both may be used alone or in combination. From the viewpoint of weather resistance and print density of the decorative image, it is preferable to use a pigment as a coloring material.
The content of the coloring material is preferably in the range of 0.01 to 20% by mass with respect to the total amount of ink. Further, the content of the coloring material is more preferably 0.1% by mass or more, further preferably 0.5% by mass or more, further preferably 1% by mass or more, and 15% by mass. % Or less, more preferably 10% by mass or less, and even more preferably 8% by mass or less.

As the dye, a dye generally used in the technical field of printing can be used, and the dye is not particularly limited. Specific examples thereof include basic dyes, acidic dyes, direct dyes, soluble bat dyes, acidic mordant dyes, mordant dyes, reactive dyes, bat dyes, sulfide dyes, etc. Among these, water-soluble dyes, reduction dyes, etc. Those that become more water-soluble can be used. More specifically, azo dyes, rhodamine dyes, methine dyes, azomethine dyes, xanthene dyes, quinone dyes, triphenylmethane dyes, diphenylmethane dyes, methylene blue and the like can be mentioned. These dyes may be used alone or in combination of two or more.

As the pigment, organic pigments such as azo pigments, phthalocyanine pigments, polycyclic pigments and dyed lake pigments, and inorganic pigments can be used. Examples of the azo pigment include soluble azo lake pigments, insoluble azo pigments and condensed azo pigments. Examples of the phthalocyanine pigment include metal phthalocyanine pigments and non-metal phthalocyanine pigments. Polycyclic pigments include quinacridone pigments, perylene pigments, perinone pigments, isoindolin pigments, isoindolinone pigments, dioxazine pigments, thioindigo pigments, anthracinone pigments, quinophthalone pigments, and metal complex pigments. And diketopyrrolopyrrole (DPP) and the like. Typical examples of the inorganic pigment include carbon black and titanium oxide. These pigments may be used alone or in combination of two or more.
As the pigment, an anionic pigment having an anionic group such as a carboxyl group, a sulfonic acid group, a phosphoric acid group, a phosphonic acid group, a phenylsulfonic acid group and a phenylcarboxyl group is more preferable.

A pigment dispersant can be added to the ink, if necessary, in order to improve the dispersion of the pigment in the ink. The pigment dispersant that can be used is not particularly limited as long as it stably disperses the pigment in the solvent. For example, a known pigment represented by a polymer dispersant or a surfactant having a pigment-dispersing ability. It is preferable to use a dispersant. Specific examples of polymer dispersants include Solspers (trade name) series manufactured by Japan Lubrizol Co., Ltd., John Krill (trade name) series manufactured by BASF Japan Ltd., DISPERBYK series manufactured by Big Chemie Japan Co., Ltd., and BYK series. , TEGO Dispers 750W manufactured by Ebonic Japan Co., Ltd., TEGO Dispers 760W and the like. Specific examples of surfactants include nonionic polyoxys such as anionic fatty acid salts, alkyl sulfates, alkyl ether sulfates, and alkylbenzene sulfonates, such as the Demol (trade name) series manufactured by Kao Co., Ltd. Examples thereof include alkylene alkyl ethers.
The content of the pigment dispersant is sufficient as long as the pigment can be sufficiently dispersed in the solvent, and can be appropriately set, for example, in the range of 0.01 to 2 by mass with respect to the pigment 1.

A self-dispersing pigment whose surface is modified with a hydrophilic functional group may be used. Examples of commercially available self-dispersing pigments include CAB-O-JET series manufactured by Cabot Japan Co., Ltd. (CAB-O-JET200, 300, 250C, 260M, 270Y, 465M) and BONJET series manufactured by Orient Chemical Industry Co., Ltd. (BONJET BLACK CW-1, CW-2, CW-4) and the like. Microencapsulated pigments in which the pigments are coated with a resin may be used.

The ink preferably contains a water-dispersible resin. Thereby, the fixability of the ink can be improved.

As the water-dispersible resin, it is preferable to use an anionic water-dispersible resin having a negatively charged particle surface and a negative charge. This is capable of forming an oil-in-water (O / W) emulsion by dispersing in particles without being dissolved in water. An anionic functional group of the resin may be present on the particle surface, such as a self-emulsifying resin, or a surface treatment such as attaching an anionic dispersant to the surface of the dispersible resin may be performed. .. The anionic functional group is typically a carboxy group, a sulfo group or the like, and the anionic dispersant is an anionic surfactant or the like. When the surface is anionic, a chemical interaction with the cationic water-dispersible resin in the pretreatment liquid is obtained, and as a result, the fixing of the coloring material is further strengthened and the durability of the image is further improved. Can be enhanced.
Here, the strength of the anionic property can be expressed by the charge density measured by the flow potential method as described above, and the ink to be measured with a colloidal particle charge meter (AFGANALYTIC GmbH, Model CAS) is ion-exchanged water. The value measured using a 0.0025N polyallyl dimethyl-ammonium chloride solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a titrant using a solution diluted 100-fold with -20 μeq / g or less. It is preferable, further, it is preferably −40 μeq / g or less.

As the type of resin, it is preferable to use a resin that forms a transparent coating film. In addition, it can be blended as a resin emulsion in the production of ink. Typically, ethylene-vinyl chloride copolymer resin, (meth) acrylic resin, styrene-maleic anhydride copolymer resin, urethane resin, vinyl acetate- (meth) acrylic copolymer resin, vinyl acetate-ethylene copolymer weight. Examples thereof include coalesced resins and resin emulsions thereof, which can be used alone or in combination of two or more. Here, "(meth) acrylic resin" refers to both acrylic resin and methacrylic resin. As described above, an anionic functional group can be introduced into these resins, or a surface treatment with an anionic dispersant or the like can be applied to give a negative surface charge.

Of these water-dispersible resins (or emulsions thereof), urethane resins (emulsions) are preferably used from the viewpoint of stable ejection performance from the inkjet head and adhesion to the substrate. Specific examples of such a resin emulsion include Superflex 300, 460, 420, 470, 460S, 150HS, 740 manufactured by Daiichi Kogyo Seiyaku Co., Ltd., and NeoRez R-9660, R-2170, R-966 manufactured by DSM Corporation. , R-967, R-650, R-986, R-9603, ADEKA Co., Ltd. ADEKA Bontiter HUX-370, 380 and the like.

Further, from the viewpoint of stability in ink, it is also preferable to use a (meth) acrylic resin or a (meth) acrylic resin copolymer. Specifically, Movinyl 702, 1711, 6520, 8020 manufactured by Japan Coating Resin Co., Ltd., John Krill 7100, PDX-7370, PDX-7341, PDX-7341 manufactured by BASF Japan Ltd., Boncoat EC-905EF, 5400EF manufactured by DIC Corporation, Examples thereof include CG-8400 and Neocryl BT-62 manufactured by DSM Corporation.
The water-dispersible resin may be composed of a single resin emulsion such as a urethane resin or an acrylic resin, or may be composed of a combination of a plurality of resin emulsions.

The water-dispersible resin forming the emulsion may have a particle size suitable for inkjet printing, and generally has an average particle size (medium diameter measured by a volume standard by a dynamic light scattering method) of 300 nm or less. Is preferable. A more preferable value of the average particle size is 250 nm or less, a further preferable value is 200 nm or less, and a further preferable value is 150 nm or less. The lower limit of the average particle size is not particularly limited, but from the viewpoint of storage stability of the ink, it is preferably about 5 nm or more, and more preferably 10 nm or more.

The amount of the water-dispersible resin (solid content) in the ink is preferably 1: 0.5 to 1: 7 (mass ratio) in terms of the ratio of the coloring material to the resin (coloring material: resin). By setting the resin content in this range, it is possible to sufficiently ensure the water scratch resistance and high image quality of the image printed on the surface of the base material. If the ratio of the resin to the color material 1 is less than 0.5, the fixability of the pigment may be deteriorated, and if it is larger than 7, the viscosity may be high and the ink may not be ejected from the head for ejecting the ink. There is.

In addition, a surface tension lowering agent is added to the ink in order to reduce the surface tension of the ink, ensure ejection stability when introduced into the inkjet head, and quickly allow the ink to penetrate into the substrate to be printed. be able to. As the surface tension lowering agent, a surfactant having an effect of further suppressing the aggregation of the water-dispersible resin, for example, a nonionic surfactant or an anionic surfactant similar to that blended in the pretreatment liquid. Agents can also be used. A surfactant having both a pigment dispersion function and a surface tension lowering function may be used.

As anionic surfactants, Kao Corporation's Emar series (Emar 0, Emar 10, Emar 2F, Emar 40, Emar 20C), Neoperex series (Neoperex GS, Neoperex G-15, Neoperex G-25) , Neo Perex G-65), Perex Series (Perex OT-P, Perex TR, Perex CS, Perex TA, Perex SS-L, Perex SS-H), Demor Series (Demor N, Demor NL, Demor RN, Demor) MS).

The amount of the surface tension lowering agent in the ink is preferably about 0.1% by mass or more, more preferably 0.3% by mass or more, and further preferably 0.5% by mass or more. On the other hand, the amount of the surface tension lowering agent is preferably about 5% by mass or less, more preferably 4% by mass or less, and may be 3% by mass or less.

In addition to the above components, other components such as antifoaming agents, pH adjusters, antioxidants, preservatives, and dispersion aids can be added to the ink as long as the functions of the ink are not impaired. The dispersion aid referred to here is a dispersant additionally added to the pigment dispersion that has already been dispersed, and a general dispersant can be used as the dispersion aid.

The method for producing the ink is not particularly limited, and the ink can be appropriately produced by a known method. For example, all the components can be collectively or divided and dispersed in a known disperser such as a bead mill, and if desired, can be prepared by passing through a known filter such as a membrane filter. For example, a mixed solution in which the entire amount of water and the coloring material is uniformly mixed is prepared in advance, dispersed by a disperser, and then the remaining components are added to the dispersant and passed through a filter. Can be done.

The ink set may contain a plurality of the above-mentioned pretreatment liquids and / or water-based inkjet inks, if necessary. The ink set may contain, for example, other inks and / or treatment liquids, if necessary.

<Manufacturing method of decorations>
In the method for producing a decorative object according to an embodiment of the present invention, the above-mentioned pretreatment liquid is attached to the surface of the base material, and after the pretreatment step, the above-mentioned water-based inkjet ink is used to prepare the base material. Includes a step of inkjet printing on the surface.
In the method for producing a decorative object of the present embodiment, the flat particles adhering to the base material can suppress or reduce the permeation of the ink into the base material by pre-treating the surface with the above-mentioned pretreatment liquid. Therefore, a highly colored image can be formed on the surface of the base material.
The pretreatment liquid and ink are as described above. As described above, "decorated" is synonymous with decoration and means forming a printed image, and "decorated" means having a printed image. This decorated portion may be an object, that is, the entire surface or a part of the base material.

The base material that can be used by the present invention is not particularly limited, and is a permeation base material such as paper, cloth, functional porous material (humidity control, sound absorption, heat insulation, etc.), wood, concrete, resin sheet, metal plate, varnish, etc. A low-penetration or non-penetrating substrate such as coated wood or ceramic can be preferably used. The present invention can exert a great effect particularly on a penetrating base material.

Adhesion of the pretreatment liquid to the substrate surface may be performed by uniformly applying the pretreatment liquid to the substrate surface using a brush, a roller, a bar coater, an air knife coater, or a spray, or inkjet printing or gravure. This may be done by printing the image by a printing means such as printing or flexographic printing. That is, the pretreatment liquid may be applied to the entire surface of the base material surface, or may be applied only to necessary places, for example, only to places where inkjet printing using the above ink is performed. Further, the attachment location of the pretreatment liquid may include not only the surface of the base material but also the inside (inner surface) of the pores.

The coating amount (adhesion amount) of the pretreatment liquid cannot be specified uniformly because it differs depending on the type and material of the base material, but the coating area is required to achieve a certain color development and gloss of the decorative image. as non-content per, for example, it is preferably ^1g / ^{m 2 ~50g} / m 2 ^{approximately,} and more preferably 5g / ^{m 2} ~30g / m 2 approximately.

The coating amount (adhesion amount) of the pretreatment liquid is preferably 0.1 g / m ² or more, more preferably 0.2 g / m ² or more, as the coating amount of the flat particles. When the coating amount (adhesion amount) of the pretreatment liquid is 0.1 g / m ² or more as the coating amount of the flat particles, it is easy to improve the color development property. Further, the coating amount of the pretreatment liquid (adhesion amount) is preferably 5.0 g / ^{m 2} or less as a coating amount of the flat particles, more preferably not more than ^{3.0g / m 2, 1.0g / m} 2 The following is more preferable. The coating amount of the pretreatment liquid (adhesion amount) is, as a coating amount of the flat particles, for ^example, be ^{0.1g / m 2 ~1.0g / m 2} .

The base material may be heated after the pretreatment liquid is applied, the water and other volatile components in the pretreatment liquid are completely volatilized, and the flat particles in the pretreatment liquid are fixed to the base material by the water-dispersible resin. Can be made to. The method for heating the base material is arbitrary, and the heating temperature is not particularly limited, and can be heated in the range of, for example, 50 to 200 ° C.

In the inkjet printing step, the above-mentioned water-based inkjet ink is used for inkjet printing on the surface of the base material.

Inkjet printing using a water-based ink on a base material can be performed using a general recording head, and there are no particular restrictions on the printing method, the apparatus used, and the like. After printing (decoration), by drying, water and other volatile components are volatilized from the inkjet-printed ink on the surface of the base material, and an image containing a coloring material or the like is provided. Is obtained.
The recording area of the image is not particularly limited, and any pattern or character, or a combination of the pattern and the character can be freely selected.

In order to obtain a high-quality decorative image, (i) reduce the ink droplets, (ii) slow down the printing speed, (iii) perform one-way printing, and (iv) print while warming the substrate. , (V) It is effective to use printing conditions such as printing by combining these methods.

The base material may be heated after the printing is completed, the water in the ink and other volatile components may be completely volatilized, and the coloring material in the ink may be fixed to the base material by the water-dispersible resin. The method of heating the substrate is arbitrary, and can be heated in the range of, for example, 50 to 200 ° C.

The method for producing the decoration may include other steps, if necessary.
For example, another arbitrary treatment may be performed before the pretreatment with the pretreatment liquid. In addition, the substrate before printing may be subjected to any other treatment after the pretreatment step with the pretreatment liquid.

The device for decorating is not particularly limited, but for example, a mounting portion for mounting the base material, a pretreatment liquid coating portion for applying the pretreatment liquid to the surface of the base material, and the like. A decorating device can be used that includes at least an inkjet recording head arranged for ejecting ink and performing inkjet printing, and more preferably an optional heating unit for heating the substrate.

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples. Unless otherwise specified, "%" is "mass%". The blending amount of each component in the table is also indicated by "mass%".

<Manufacturing of pretreatment liquid>
Each material shown in Tables 1 and 2 is premixed at the ratios shown in Tables 1 and 2, and then stirred with a rotating blade of 10 cm at 400 rpm for 10 minutes to pretreat Examples 1 to 10 and Comparative Examples 1 to 4. I got the liquid.

Details of each material shown in Tables 1 and 2 are as follows.
"Metashine 1030RY: Nippon Sheet Glass Co., Ltd., titanium oxide coated glass flakes, average major axis 30 μm
"MagnaPearl 3000": Titanium oxide coated mica manufactured by BASF Japan Ltd., average major axis 4 μm
"Alpaste EMR-D5660": Titanium oxide-coated aluminum flake aqueous dispersion manufactured by Toyo Aluminum K.K., average major axis 10 μm
"PP-17": Made by Meisei Chemical Works, Ltd., Cationic water-dispersible composite resin aqueous dispersion, average particle size 2.5 μm
"Aquatex AC-3100": Made by Japan Coating Resin Co., Ltd., Cationic aqueous ethylene / methacrylic acid aqueous dispersion, average particle size 0.7 μm
"Himax SC-700L": manufactured by Himax Co., Ltd., polyvinyl amidine-based water-soluble cationic resin "magnesium chloride hexahydrate": manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., purity 97% (in the example, anhydrous magnesium chloride amount) Converted to)
"Silface SAG002": Nisshin Kagaku Kogyo Co., Ltd., Silicone surfactant "Surfinol 485": Nissin Kagaku Kogyo Co., Ltd., acetylene glycol-based surfactant "Seahoster KE-P250": Nippon Catalyst Co., Ltd. Manufactured by, silica particles for water dispersion, particle size 2.5 μm
"Diethylene glycol": manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

In the above materials, the "average particle size" of the resin is determined by using a dynamic light scattering type particle size distribution measuring device "nanoparticle analyzer nanoPrtica SZ-100" (manufactured by Horiba Seisakusho Co., Ltd.). Is diluted with purified water so that the particle concentration is 0.5% by mass, and is a volume-based median diameter measured at a temperature of 25 ° C.

In the above material, the average major axis of the flat particles is the median value of the major axis obtained for each of the 20 particles arbitrarily selected in the SEM photograph.

<Ink manufacturing>
The following materials were premixed at the ratios shown below, and then stirred with a 10 cm rotating blade at 400 rpm for 10 minutes to obtain magenta (M) ink.
"CAB-O-JET 465M": Made by Cabot Japan Co., Ltd., water-based self-dispersed magenta pigment dispersion, active ingredient 15.2%, 30.0% by mass
"ADEKA BONTITER HUX-370": ADEKA CORPORATION, anionic water-based urethane resin emulsion, active ingredient 33.0%, 8.0% by mass
"Diethylene glycol": manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 20.0% by mass
"Silface SAG002": manufactured by Nissin Chemical Industry Co., Ltd., silicone-based surfactant, 100% active ingredient, 1.0% by mass
"Ion-exchanged water" 41.0% by mass

<Manufacturing of decorations>
The pretreatment liquids of Examples and Comparative Examples shown in Tables 1 and ² were applied to a thin mouth of ideal paper (manufactured by Riso Kagaku Corporation) at an amount of 10 g / m ² . The pretreatment liquid was applied by spraying, and after the treatment, it was dried in an oven at 120 ° C. for 30 minutes to obtain a pretreatment article. Then, the above-mentioned ink was introduced into the ink head of a commercially available water-based pigment inkjet printer, and a fine K character of font 6 and a solid image of 5 cm × 5 cm were printed. After the printing was completed, the product was heated and dried in an oven at 120 ° C. for 30 minutes and used as a decoration.

The decorated base materials of each of the Examples and Comparative Examples obtained as described above were evaluated as follows.

<Blur>
The bleeding was determined by observing the bleeding on the fine edge of K in the printed matter with a microscope and using the following evaluation criteria. The results are shown in "Blur" in Tables 1 and 2.
AA: No bleeding A: Almost no bleeding B: Bleeding but no problem in practical use C: Severe bleeding is problematic in practical use

<Metallic feeling>
The metallic feeling was judged by visually observing the printed matter and using the following evaluation criteria. The results are shown in "Metallic feeling" in Tables 1 and 2.
AA: Very strong metallic feeling A: Strong metallic feeling B: Weak metallic feeling C: No metallic feeling

<Water resistance of printed matter>
The water resistance of the printed matter is evaluated by applying a load of 100 g to a cotton swab soaked in water, repeating a reciprocation of 2 cm in length on the solid part of the printed matter, measuring the number of times the solid part begins to peel off, and evaluating it according to the following criteria. did. The results are shown in "Water resistance" in Tables 1 and 2.
A: 50 times or more B: 20 to 49 times C: Less than 20 times

In Examples 1 to 10 which were pretreated with a pretreatment liquid containing water, flat particles, and a cationic water-dispersible resin and having a charge density of 50 μeq / g or more, bleeding, metallic feeling, and water resistance were observed. Excellent results were shown in all items of sex.
On the other hand, in Comparative Example 1 having a charge density of less than 50 μeq / g and Comparative Examples 2 to 4 not containing the cationic water-dispersible resin, image bleeding occurred, and Comparative Examples 2 to 4 were printed matter. The evaluation result was also low in terms of water resistance.

Claims (3)

After the pretreatment step of adhering a pretreatment liquid containing water, flat particles, and a cationic water-dispersible resin and having a charge density of 50 μeq / g or more to the surface of the substrate, and the pretreatment step, A method for producing a decorative object, which comprises a step of inkjet printing on the surface of a base material using a water-based inkjet ink containing water and anionic particles.
The method for producing a decorative object according to claim 1, wherein the charge density of the pretreatment liquid is 100 μeq / g or more.
An ink set containing a pretreatment liquid containing water, flat particles, and a cationic water-dispersible resin and having a charge density of 50 μeq / g or more, and an aqueous inkjet ink containing water and anionic particles.