JP6544906B2 - Ink jet printed matter and method of manufacturing ink jet printed matter - Google Patents

Description

  The present invention relates to an ink receiving layer forming paint and an ink jet print. More specifically, an ink receiving layer forming paint capable of forming an ink receiving layer suitable for applying a UV curable ink, and an ink jet printing of the UV curable ink on the ink receiving layer formed of the paint Ink jet printed matter obtained by

  In recent years, application to various materials of ink jet printing is examined. Specifically, fabric, absorbent substrate such as paper, ceramic siding plate, metal siding plate, concrete block, wood, slate plate, medium density fiber plate (MDF), acrylic plate, PP plate, polycarbonate plate, PVC plate And non-absorptive base materials such as resin boards.

  When ink jet printing is performed on a non-absorptive substrate, it has been proposed to form an ink receiving layer for the purpose of improving the design of the ink jet printed matter and improving the physical properties of the product. For example, Patent Document 1 discloses a decorative construction board in which an ink jet print layer is formed on an ink receiving layer.

  Moreover, as an ink used for inkjet printing, attention to an ultraviolet curing ink is increasing. For example, Patent Document 2 discloses an outdoor colored plate obtained by inkjet printing an ultraviolet curable ink on a substrate. The ultraviolet curable ink is characterized in that it is quick-drying and has high production efficiency as compared with volatile ink such as solvent type or water type. In addition, the ink itself is excellent in water resistance, and the pigment contained in the ink is characterized by being difficult to discolor and fade.

  The ultraviolet curable ink has a feature that the resin is cured instantaneously by being irradiated with the ultraviolet light, and the liquid absorbing property of the surface of the substrate is not required, so the image can be formed without providing the ink receiving layer on the substrate It is possible to form. However, even in the case of the ultraviolet curable ink, depending on the compatibility with the substrate, wetting or repelling may occur, which may affect the formed image quality. Therefore, there is a need for an ink receiving layer suitable for UV curable ink in order to obtain excellent image quality.

  Moreover, in the manufacturing process of an inkjet printed matter, the base-material surface temperature at the time of inkjet printing may differ with used base materials. Therefore, in order to obtain versatility of the ink, development of an ink receiving layer for enabling formation of a high quality image without being influenced by the substrate surface temperature at the time of ink jet printing is also required.

JP, 2008-057131, A JP, 2008-080629, A

  The present invention has been made in view of the above problems, and an ink receiving layer forming paint capable of forming an ink receiving layer suitable for inkjet printing using an ultraviolet curable ink, and the paint It is an object of the present invention to provide an inkjet print obtained by inkjet printing an ultraviolet curable ink on an ink receiving layer and a method for producing the inkjet print.

The ink receiving layer forming paint of the present invention is an ink receiving layer forming paint containing at least an acrylic resin and fine particles, and the calculated Tg of the acrylic resin is in the range of -5 to 30 ° C. The content of the non-volatile component in the paint is 20 to 50% by mass.
It is preferable that the fine particles have a porous shape.
In addition, the ink jet print of the present invention is characterized in that an ink jet print layer of an ultraviolet curable ink is formed on an ink receiving layer made of the ink receiving layer forming paint formed on a substrate. .
Moreover, the method for producing an inkjet print of the present invention is
(1) applying a paint on a substrate to form an ink receiving layer;
(2) After the step (1), a step of applying an ink jet print using a UV curable ink,
(3) A method of producing an inkjet printed matter, comprising the step of curing the ultraviolet curable ink by ultraviolet irradiation after the step (2),
The paint applied in the step (1) contains an acrylic resin having a calculated Tg in the range of -5 to 30 ° C., and further contains 20 to 50% by mass of fine particles with respect to non-volatile components in the paint. It features.

  According to the present invention, in ink jet printing using an ultraviolet curable ink, an ink capable of forming an ink receiving layer capable of forming an image having good image quality without being influenced by the substrate surface temperature It is possible to provide a receiving layer forming paint. Further, according to the present invention, it is possible to provide an inkjet print having a high quality image using an ultraviolet curable ink.

It is a graph which shows the relation between substrate surface temperature at the time of ink jet, and line width about Examples 1-3 given in this specification. It is a graph which shows the relation between substrate surface temperature at the time of ink jet, and line width about comparative examples 1-4 of this statement statement.

An acrylic resin having a calculated Tg in the range of -5 to 30 ° C is used for the ink receiving layer forming paint of the present invention.
Here, the calculated Tg is the glass transition temperature determined by the following equation.

Fox's formula: 1 / Tg = a ₁ / Tg ₁ + a ₂ / Tg ₂ +... + A _n / Tg _n
a ₁ , a ₂ ,..., a _n : Mass fraction of each monomer Tg ₁ , Tg ₂ ,..., Tg _n : Tg of each monomer homopolymer

By using an acrylic resin having a calculated Tg in the range of -5 to 30 ° C., the formed ink receiving layer is in a softened state under inkjet conditions (usually around 25 ° C. for room temperature).
When the ink receiving layer is softened under the ink jet conditions, the surface resistance of the ink receiving layer is increased, and it is possible to suppress excessive wetting and spreading of the landed UV curable ink. In addition, when the ultraviolet curable ink lands on the ink receiving layer in a softened state, erosion of the ultraviolet curable ink in the depth direction with respect to the ink receiving layer is likely to occur, thereby suppressing ink bleeding upon landing and receiving the ink. The adhesion between the layer and the inkjet print layer can be improved.
If the calculated Tg is less than -5 ° C, although ink bleeding is suppressed, depending on the resolution, the applied image may be noticeable as a streaky appearance. In addition, the tackiness of the formed ink receiving layer becomes high, and it becomes difficult to temporarily store the ink receiving layer in a state where the ink receiving layer is formed on the substrate in the process of producing the ink jet printed matter.
On the other hand, when the calculated Tg exceeds 30 ° C., ink bleeding is likely to occur, particularly under inkjet conditions at room temperature, and there is a risk that thin line expression may become difficult. In addition, the erosion of the ultraviolet curable ink in the depth direction with respect to the ink receiving layer is reduced, and the adhesion between the ink receiving layer and the ink jet print layer may not be sufficiently obtained.
In addition, by setting the calculated Tg to the above range, even when the substrate temperature is high (for example, 60 ° C.), the ink receiving layer is in a softened state, and an effect similar to that at room temperature can be obtained. it can.

  Examples of the acrylic resin include acrylic resin, acrylic-styrene resin, acrylic-silicone resin, acrylic-urethane resin and the like.

The ink receiving layer forming paint of the present invention contains fine particles. Here, the fine particles refer to those having an average particle diameter of 1 to 15 μm, a BET specific surface area of 10 m ² / g or more, and an oil absorption amount of 55 ml / 100 g or more according to JIS K-5101-13-2. The fine particles include those by aggregation, those by synthesis, and those by acid treatment. By containing the fine particles, fine irregularities are formed by the fine particles on the surface of the ink receiving layer, which makes it possible to uniformly adhere the landed ultraviolet curable ink. In addition, in the case of applying ink jet printing to a substrate having a concavo-convex pattern or a concavo-convex shape on the surface, the applied ultraviolet curable ink is accumulated in the concave part of the substrate and the ink adhesion amount to the convex part is reduced. It is possible to suppress the whiteness of the image (the phenomenon that the image looks whitish) caused by

The fine particles need to be contained in an amount of 20 to 50% by mass with respect to the non-volatile component in the paint. Here, the non-volatile component in the paint means a component that forms a solid when the ink receiving layer-forming paint is applied and dried.
By setting the content of the fine particles to 20 to 50% by mass with respect to the non-volatile component in the paint, it is possible to form an image in which the streaky feeling is reduced while maintaining the thin line expression.
If the content of the fine particles is less than 20% by mass, the streaks of the image may be noticeable depending on the resolution.
On the other hand, when the content of the fine particles exceeds 50% by mass, the formed ink receiving layer becomes fragile, and there is a possibility that a crack may occur or a film forming property may not be sufficiently obtained.

  The fine particles are preferably in a porous shape. When the fine particles have a porous shape, the ink landed on the surface of the ink receiving layer can be uniformly spread by capillary action.

  Specific examples of the fine particles used in the present invention include calcium carbonate, silica and zeolite as inorganic particles. Examples of organic particles include acrylic beads.

  The paint for forming an ink receiving layer of the present invention may contain, in addition to the above-mentioned acrylic resin and fine particles, a pigment and, if necessary, various additives.

  Examples of the pigment include organic or inorganic pigments. Examples of the organic pigment include nitroso, dyed lakes, azo lakes, insoluble azos, monoazos, disazos, condensed azos, benzimidazolones, and phthalocyanines. , Anthraquinones, perylenes, quinacridones, dioxazines, isoindolines, azomethines and pyrrolopyrroles. As the inorganic pigment, for example, oxides, hydroxides, sulfides, ferrocyanides, chromates, carbonates, silicates, phosphates, carbons (carbon black) and metal powders Etc.

  As various additives, heat stabilizers, antioxidants, preservatives, antifoaming agents, penetrants, reduction agents, leveling agents, pH adjusters, pigment derivatives, polymerization inhibitors, ultraviolet absorbers, light stabilizers, etc. Can be mentioned. It is also possible to appropriately add a solvent such as ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, or benzyl alcohol as a film forming aid.

  Next, a method of producing an ink jet print using the ink receiving layer forming paint of the present invention will be described.

  The substrate is not particularly limited as long as the ink receiving layer can be formed. In addition, in the case of a substrate to which the ink receiving layer does not easily adhere, an undercoat layer can be provided in advance on the substrate in order to improve the adhesion between the substrate and the ink receiving layer. The paint for forming the undercoat layer may be any of a water-based paint, a solvent-based paint, and an ultraviolet-curable paint. Among them, a water-based paint is preferable in terms of workability, safety, and adhesion with the ink receiving layer. Paint is desirable.

Next, the ink receiving layer is formed by applying the above-described ink receiving layer-forming paint on the substrate or the undercoat layer. At this time, the coating amount of the ink receiving layer forming paint is preferably 10 to ²⁰⁰ g / m ² (dry state).
If the coating amount is less than 10 g / m ² , there is a possibility that the substrate surface can not be completely covered, and if it exceeds 200 g / m ² , the thickness of the ink receiving layer becomes large and cracks may occur.

  The thickness of the ink receiving layer to be formed is preferably 10 to 150 μm. If the thickness of the ink receiving layer to be formed is less than 10 μm, the ink receiving layer may not completely cover the substrate surface, and if it exceeds 150 μm, the ink receiving layer may be cracked.

  The application of the ink receiving layer forming paint can be performed by a spray, a curtain flow coater, a roll coater or the like, and is not particularly limited.

  The ink receiving layer can be dried by hot air drying, air drying, drying by a heater, drying by a hot plate, or the like, and is not particularly limited. The drying temperature and time may be appropriately determined, but the drying temperature is preferably 60 to 150 ° C., and the drying time is preferably 0.5 to 30 minutes.

  Next, a UV curable ink is applied by an inkjet method on the formed ink receiving layer, and then cured to form an inkjet print layer.

  The UV curable ink used herein contains a reactive monomer, a reactive oligomer, a photopolymerization initiator, a pigment, and further, various additives as necessary. As the pigment, the same ones as those described in the ink receiving layer forming paint can be used.

  The pigment weight concentration of the ultraviolet curable ink is preferably 0.5 to 20 parts by weight in 100 parts by weight of the ultraviolet curable ink. When the weight concentration of the pigment is less than 0.5 parts by weight, coloring may be insufficient, and an intended "image" may not be formed. In addition, when the pigment weight concentration exceeds 20 parts by weight, the viscosity of the ultraviolet curable ink becomes too high, and there is a possibility that the ink can not be discharged from the nozzle of the ink jet printer. Here, the pigment weight concentration is the pigment concentration with respect to the non-volatile component of the ultraviolet curable ink.

Examples of the reactive monomer used for the ultraviolet curable ink include hexafunctional acrylates such as dipentaerythritol hexaacrylate and modified products thereof; pentafunctional acrylates such as dipentaerythritol hydroxypentaacrylate; pentaditrimethylolpropane tetraacrylate Trifunctional acrylate such as pentaerythritol tetraacrylate; trifunctional acrylate such as trimethylolpropane triacrylate, pentaerythritol triacrylate, tris (2-hydroxyethyl) isocyanurate triacrylate, glyceryl triacrylate; neopentyl glycol dihydroxypivalate Acrylate, polytetramethylene glycol diacrylate, trimethylolpropane acrylic acid Breath ester, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol (200) diacrylate, polyethylene glycol (400) diacrylate, polyethylene glycol (600) diacrylate, neopentyl glycol diacrylate 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, dimethylol-tricyclodecane diacrylate, bisphenol A diacrylate and the like Difunctional acrylates; and caprolactone acrylate, tridecyl acrylate, isodecyl acrylate, isooctyl Crylates, isomyristyl acrylate, isostearyl acrylate, 2-ethylhexyl-diglycol diacrylate, 2-hydroxybutyl acrylate, 2-acryloyloxyethyl hexahydrophthalic acid, neopentyl furicol acrylic acid benzoate, isoamyl acrylate, lauryl Acrylate, stearyl acrylate, butoxyethyl acrylate, ethoxy-diethylene glycol acrylate, methoxy-triethylene glycol acrylate, methoxy-polyethylene glycol acrylate, methoxydipropylene glycol acrylate, phenoxyethyl acrylate, phenoxy-polyethylene glycol acrylate, nonylphenol acrylate, tetrahydrofurfuryl acrylate relay , Isobornyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-acryloyloxyethyl-succinic acid, 2-acryloyloxyethyl-phthalic acid, 2 And monofunctional acrylates such as acryloyloxyethyl-2-hydroxyethyl-phthalic acid. Among them, bifunctional monomers are preferable in that they are excellent in toughness and flexibility. Among the bifunctional monomers, aliphatic reactive monomers consisting of a hydrocarbon, in particular 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, 1,3-butanediol in that they are resistant to yellowing. Preferred are diacrylate, 1,4-butanediol diacrylate, 1,9-nonanediol diacrylate and the like.
The reactive monomer further includes a reactive monomer obtained by adding a functional group of phosphorus, fluorine, ethylene oxide or propylene oxide to the reactive monomer. Moreover, these reactive monomers can be used individually or in combination of 2 or more types.

  The reactive monomer is preferably contained in an amount of 50 to 85 parts by weight in 100 parts by weight of the ultraviolet curable ink. When the content is less than 50 parts by weight, the viscosity of the ultraviolet curable ink becomes high, and there is a possibility that ejection failure may occur when ink jet printing is performed. On the other hand, if it exceeds 85 parts by weight, other components necessary for curing the ink may be insufficient, which may result in curing failure.

Examples of the reactive oligomer used for the ultraviolet curable ink include urethane acrylate, polyester acrylate, epoxy acrylate, silicon acrylate and polybutadiene acrylate, which may be used alone or in combination of two or more. Among them, urethane acrylate is preferable in that it is excellent in toughness, flexibility and adhesion. Among urethane acrylates, aliphatic urethane acrylates composed of hydrocarbon are more preferable in that they are resistant to yellowing.
Moreover, it is also possible to mix and use a reactive monomer in advance to a reactive oligomer. The reactive monomer to be mixed is preferably bifunctional and / or trifunctional. In the mixing of the reactive oligomer and the reactive monomer, the reactive monomer can be appropriately added to such an extent that the performance of the reactive oligomer is not impaired.

  The reactive oligomer is preferably contained in an amount of 1 to 40 parts by weight, more preferably 5 to 40 parts by weight, and still more preferably 10 to 30 parts by weight in 100 parts by weight of the ultraviolet curable ink. . By setting the content of the reactive oligomer in the above range, the cured film of the ultraviolet-curable ink can be made excellent in toughness, flexibility, and adhesion.

Examples of the photopolymerization initiator used for the ultraviolet curable ink include benzoins, benzyl ketals, amino ketones, titanocenes, bisimidazoles, hydroxy ketones and acyl phosphine oxides, and may be used alone or in combination of two or more. It can be used in combination. Among them, hydroxy ketones and acyl phosphine oxides are preferable in that they are highly reactive and are resistant to yellowing.

  The amount of the photopolymerization initiator added is preferably 1 to 15 parts by weight, and more preferably 3 to 10 parts by weight in 100 parts by weight of the ultraviolet curable ink. If the content is less than 1 part by weight, polymerization may not proceed sufficiently and may be uncured. Further, even if it is added in excess of 15 parts by weight, no further improvement in the curing rate or curing rate can be expected, resulting in an increase in cost.

  Further, if necessary, a dispersant may be added to the ultraviolet curable ink for the purpose of dispersing the pigment. Examples of the dispersant include anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, and polymeric dispersants, which may be used alone or in combination of two or more. Can.

  Furthermore, if necessary, the ultraviolet curable ink may further include a sensitizer, a heat stabilizer, an antioxidant, an antiseptic agent, an antifoaming agent, a penetrant, and a resin binder for accelerating the initiation reaction of the photopolymerization initiator. Various additives such as resin emulsions, reduction inhibitors, leveling agents, pH adjusters, pigment derivatives, polymerization inhibitors, UV absorbers and light stabilizers can also be added.

  The UV curable ink is obtained by mixing the above-mentioned raw materials used and dispersing the mixture using a dispersing machine such as a roll mill, a ball mill, a colloid mill, a jet mill or a bead mill, and then filtering it. Can. Among them, a bead mill is preferred in that it can be dispersed in a short time and in a large amount.

  The viscosity of the ultraviolet curable ink is preferably 1 to 20 mPa · s at 50 ° C., and more preferably 2 to 15 mPa · s. If the viscosity is less than 1 mPa · s, it is difficult to adjust the discharge amount, and the discharge of the ink may be unstable. When the viscosity exceeds 20 mPa · s, there is a possibility that the ink can not be discharged.

  The surface tension of the ultraviolet curable ink is more preferably 20 to 30 dyne / cm under 25 ° C. conditions. If the surface tension of the ultraviolet curable ink under 25 ° C. conditions is less than 20 dyne / cm, the wettability of the ultraviolet curable ink itself may be too good, and the image may be blurred. Supply becomes difficult. On the other hand, if the surface tension at 25 ° C. exceeds 30 dyne / cm, the ink may be repelled on the substrate, and the image may be unclear.

  A wetting agent may be added to the ultraviolet curable ink in order to obtain the surface tension described above. The wetting agent to be used may, for example, be a silicone type, an acrylic type, or a fluorine type. Among these, a silicone type and a fluorine type are preferable in that they are excellent in the effect of reducing the surface tension.

Application amount of the ultraviolet curable ink is preferably 1 to 100 g / ^{m 2,} more preferably 1 to 50 g / ^{m 2.} When the application amount is less than 1 g / m ² , sufficient image expression may be difficult, and furthermore, the water resistance of the obtained ink jet print may be deteriorated. In addition, when the application amount exceeds 100 g / m ² , there is a possibility that the applied ultraviolet-curable ink may cause curing failure.

  Furthermore, the thickness of the ink jet print layer obtained by curing the applied ultraviolet curable ink by a method described later is preferably 1 to 150 μm. If the thickness of the ink jet print layer is less than 1 μm, it may be difficult to obtain sufficient image expression, and furthermore, the water resistance of the obtained ink jet print may be deteriorated. When the thickness exceeds 150 μm, the ink jet print layer may be cracked or peeled off.

  The system of the ink jet printer used for applying the ultraviolet curable ink is not particularly limited. For example, continuous methods such as charge modulation method, micro dot method, charge injection control method and ink mist method, piezo method, pulse jet method, bubble jet (registered trademark) method and on-demand method such as electrostatic suction method It can be used. Further, as a specific ink jet printer, a serial type, a line type and the like can be mentioned, and either of them can be used.

  The serial type causes the serial type printer to scan in the main scanning direction (moving direction of the carriage) by driving the carriage, and discharges ink while intermittently transporting the substrate in the transport direction (sub scanning direction) orthogonal to the main scanning direction. To form an image. In the printer, for example, cartridges of ink such as black (Bk), yellow (Y), magenta (M), cyan (C), etc. are mounted, and in each color cartridge, a plurality of ink discharge nozzles are main-scanned. It is provided along both the direction and the sub-scanning direction. The printer may be provided with an ultraviolet radiation device.

  When a serial type printer is used, the steps of applying ink droplets to a substrate and the step of irradiating ultraviolet light are repeated for each main scan. Here, main scanning means that the head of the serial printer moves on the same line, and the printer head moves once from left to right without moving in the sub scanning direction, from left to right A mode of moving to a plurality of times, a mode of moving once from right to left, a mode of moving a plurality of times from right to left, a mode of making one reciprocation, a mode of reciprocating a plurality of times and the like are included. Every main scanning means that every time the head of the serial printer moves from one line to another (every time movement in the sub scanning direction is performed). At each main scan of the head as described above, curing of the ink by ultraviolet irradiation is performed after the end of the ink application process or in parallel with the ink application process.

    In the line type, discharge nozzles of ink of each color are provided in a line shape across the width direction of the ink jet printer (direction orthogonal to the conveyance direction of the printing base material). For example, black (Bk), yellow (Y), magenta ( Discharge nozzles such as M) and cyan (C) are provided in a line. It is also possible to cure the ink by ultraviolet irradiation after the end of the ink application process with the line type head, or an ultraviolet irradiation device may be provided in this line type printer. When such a line-type printer is used, color change is performed for each printing of one line, and ultraviolet light is irradiated for each color change to cure the ink droplets applied to the substrate.

  When the ultraviolet curing ink is discharged by the ink jet printer, a head equipped with the ink jet printer may be equipped with a heating device, and the ink viscosity may be reduced by heating the ink for discharge. The heating temperature of the ink is preferably 25 to 150 ° C., and more preferably 30 to 70 ° C. If the temperature is less than 25 ° C., the viscosity of the ink may not be reduced, and if the temperature exceeds 150 ° C., the ink may be cured. The heating temperature of the ink is determined in consideration of the heat curing property of the reactive monomer and / or the reactive oligomer contained in the ultraviolet curable ink, and is set lower than the temperature at which the curing starts by the heat.

  As a condition of ultraviolet irradiation for curing the reactive monomer and / or reactive oligomer contained in the ultraviolet curable ink, the output of the ultraviolet lamp is preferably 50 to 280 W / cm, preferably 80 to 200 W / cm. More preferably, it is cm. If the output of the ultraviolet lamp is less than 50 W / cm, the ink may not be sufficiently cured due to the insufficient peak intensity of the ultraviolet light and the integrated light quantity, and if it exceeds 280 W / cm, the substrate is deformed or melted by the heat of the ultraviolet lamp Also, the cured film of the ink may be deteriorated.

  The irradiation time of the ultraviolet light is preferably 0.05 to 20 seconds, and more preferably 0.1 to 10 seconds. If the irradiation time of the ultraviolet lamp is less than 0.05 seconds, the integrated quantity of ultraviolet light may be insufficient, and the ultraviolet curable ink may not be sufficiently cured. Also, if it exceeds 20 seconds, the substrate may be deformed or melted by the heat of the ultraviolet lamp, and the cured film of the ink may be deteriorated.

  After the UV curable ink is cured by UV irradiation to form an ink jet print layer, a clear coating may be further applied thereon. The clear coating is applied after the formation of the ink jet print layer in order to adjust the appearance such as gloss and to improve the weather resistance. The clear paint used for the clear coating may be either water-based or solvent-based, but is preferably a water-based paint in terms of workability and safety. The clear paint is composed of a pigment, a resin, and various additives as required. As the resin and various additives, the same ones as those described in the ink receiving layer-forming coating can be used. The pigment used in the clear coating is a matting agent, and specific examples thereof include silica, resin beads and the like. If a clear clear paint layer is desired, no or only a small amount of matting agent is included. On the contrary, when it is desired to make a clear paint layer having a matte feeling, it is designed to contain a large amount of a matting agent. However, if too much is added, the image quality and physical properties of the resulting ink jet printed matter deteriorate, so the pigment weight concentration in the clear paint is preferably 15 parts by weight or less in 100 parts by weight of the clear paint. If the weight concentration of the pigment in the clear coating exceeds 15 parts by weight, the image formed by the ink jet print layer located in the lower layer may not be clearly seen, and the water resistance of the obtained ink jet print may be deteriorated. There is also.

The application amount of the clear paint is preferably 3 to 150 g / m ² (dry state). If the coating amount is less than 3 g / m ² , the substrate surface may not be completely covered, and if it exceeds 150 g / m ² , the clear paint layer may be easily cracked.

  The thickness of the clear paint layer is preferably 3 to 100 μm. If it is less than 3 μm, the substrate surface may not be completely covered, and if it exceeds 100 μm, the clear paint layer may be easily cracked.

  As the application method and the drying method of the clear paint, the same methods as those described for the ink receiving layer forming paint can be applied.

  Thus, the inkjet print according to the present invention can be obtained.

  Next, the present invention will be described by way of examples, but the present invention is not necessarily limited to these examples.

Example 1
<Ink Receiving Layer Forming Process>
The mixture was mixed according to the following formulation, stirred for 10 minutes, and filtered through 80 mesh to obtain an ink receiving layer-forming paint.

Acrylic resin: Acrnal YJ2720D 100 parts by weight (Resin content 48.0%, acrylic-styrene emulsion, Tg = 9 ° C., BASF Japan Ltd.)
-Coalescent agent: 1 part by weight of Kyowanol M (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, manufactured by Kyowa Hakko Chemical Co., Ltd.)
Fine particles: 20 parts by weight of callite KT (100% pigment content, calcium carbonate, manufactured by Taiyo Kagaku Co., Ltd.)
10 parts by weight of water

At this time, the content of the fine particles with respect to the non-volatile component in the paint was 29.4% by mass.

Next, the obtained ink-receiving layer-forming paint is applied to a slate plate by an air spray to a coating amount of 30 g / m ² (dry state), and then dried at 80 ° C. for 10 minutes. A layer was formed.

<Inkjet printing process>
The mixture was mixed according to the following formulation, dispersed using a bead mill disperser, and then filtered to remove impurities, to prepare a homogeneous ultraviolet-curable blue ink.

Blue pigment: 3 parts by weight of HOSTAPERM Blue P-BFS (CI Pigment Blue 15: 4 copper phthalocyanine blue, manufactured by Clariant Japan Ltd.)
Dispersing agent: Disperbyk-168 3 parts by weight (polymer based dispersing agent, manufactured by BykChemie)
· Reactive oligomer: CN985B88 20 parts by weight (aliphatic urethane acrylate, bifunctional, Sartomer Co., Ltd. product)
· Reactive monomer: 68.3 parts by weight of SR238F (1,6-hexanediol diacrylate, bifunctional, manufactured by Sartomer Corporation)
Photopolymerization initiator: DAROCUR 1173 5 parts by weight (2-hydroxy-2-methyl-1-phenyl-propan-1-one, Ciba Specialty Chemicals Co., Ltd.)
・ Wetting agent: DOW CORNING TORAY 32 ADDITIVE
0.7 parts by weight (Silicone-based wetting agent, manufactured by Toray Dow Corning Silicone Co., Ltd.)

The viscosity of the produced blue ink was 8.5 mPas at 50 ° C., and the surface tension was 25.0 dyne / cm at 25 ° C.

Then, using the ink jet printer, the blue ink was applied onto the ink receiving layer under the following conditions. In addition, the base-material surface temperature of the slate board at the time of ink provision was made into predetermined | prescribed temperature using shelf dryer (model | form: AD-420 Advantec Co., Ltd.). The surface temperature was measured using a non-contact thermometer (SK-8900, manufactured by Sato Meter Co., Ltd.).

イ ン ク ジ ェ ッ ト Inkjet coating conditions a) Nozzle diameter: 40 (μm)
B) Applied voltage: 50 (V)
C) Pulse width: 15 (μs)
D) Driving frequency: 5 (KHz)
E) Resolution: 400 (dpi)
F) Head heating temperature: 60 (° C)
A) Ink application amount: 7 (g / m ² )
Substrate surface temperature: 25, 40, 60, 80 (° C)

<UV-curable ink curing process>
Next, the ultraviolet curable ink was cured under the following conditions to obtain an ink jet printed matter.

紫外線 UV irradiation conditions a) Lamp type: Metal halide lamp i) Output: 100 (W / cm)
Exposure time: 0.5 (seconds)
E) Irradiation height: 10 (cm)
O) Timing from printing to irradiation: 5 (seconds)

The obtained inkjet printed matter was evaluated by the following evaluation method. The results are shown in Table 1.
Further, the relationship between the substrate surface temperature and the line width at the time of ink jet is shown in FIG.

<Evaluation method>
(1) Image quality (thin line expression)
Under each condition of substrate surface temperature (25 ° C., 40 ° C., 60 ° C., 80 ° C.), a 60 μm thin line image is inkjet printed, and the line width of the actual image formed on the obtained inkjet print is measured did. Next, based on the measurement results, the image quality (thin line expression) was evaluated according to the following criteria.

○: Line width is 200 μm or less Δ: Line width is more than 200 μm, 300 μm or less ×: Line width is more than 300 μm

Next, the thin line expression results obtained under each condition of the substrate surface temperature (25 ° C., 40 ° C., 60 ° C., 80 ° C.) were comprehensively evaluated. The thing which became (circle) under all temperature conditions was passed: (circle) and the others were made into rejection: x.

(2) Image quality (solid expression)
The solid pattern is inkjet-printed under each condition of the substrate surface temperature (25 ° C., 40 ° C., 60 ° C., 80 ° C.), and the actual image formed on the obtained inkjet print is visually confirmed, The image quality (solid expression) was evaluated according to the following criteria.

○: Solid expression is uniform (the background is clearly hidden by the image)
X: Solid expression is not uniform (Motoring (* 1) is confirmed, streak grade (* 2), etc.)

(* 1) Moto ring: Non-uniform ink landed (* 2) Stripe quality: Image has noticeable streaks and can not cover the ground clearly

Next, the solid expression results obtained under each condition of the substrate surface temperature (25 ° C., 40 ° C., 60 ° C., 80 ° C.) were comprehensively evaluated. The thing which became (circle) under all temperature conditions was passed: (circle) and the others were made into rejection: x.

(3) Cracking Property of the Surface of the Ink Receiving Layer The surface of the ink receiving layer was visually observed, and the cracking property of the surface of the ink receiving layer was evaluated using the grade of cracking specified in JIS K5600-8-4.

○: grade 0 to 1 ×: grade 2 to 5

JIS JIS K 5600-8-4 standard: Crack grade 1: not visible even if magnified 10 times Grade 2: visible if magnified 10 times Grade 3: finally recognized with a properly corrected visual acuity Grade 4: large cracks generally reaching 1 mm wide Grade 5: very large cracks generally exceeding 1 mm wide

[Example 2] The resin in the ink receiving layer forming paint was changed to acrylic resin: acrylic YJ2746DS (resin content 50.0%, acrylic-styrene emulsion, Tg = -2 ° C, manufactured by BASF Japan Ltd.) An inkjet print was produced in the same manner as in Example 1 except for the above.
The evaluation results of the obtained ink jet printed matter are shown in Table 1.
Further, the relationship between the substrate surface temperature and the line width at the time of ink jet is shown in FIG.

[Example 3]
Example 1 except that the resin in the ink receiving layer forming paint is changed to acrylic resin: Acronal YJ2716D (resin content 48.0%, acrylic-styrene emulsion, Tg = 25 ° C., manufactured by BASF Japan Ltd.) An inkjet print was produced in the same manner as in the above.
The evaluation results of the obtained ink jet printed matter are shown in Table 1.
Further, the relationship between the substrate surface temperature and the line width at the time of ink jet is shown in FIG.

Comparative Example 1
Example except that the resin in the ink receiving layer forming paint is changed to acrylic resin: Acronal YJ2741D (resin content 56.0%, acrylic-styrene emulsion, Tg = −16 ° C., manufactured by BASF Japan Ltd.) In the same manner as in 1, an inkjet print was produced.
The evaluation results of the obtained ink jet printed matter are shown in Table 1.
Further, the relationship between the substrate surface temperature and the line width at the time of ink jet is shown in FIG.

Comparative Example 2
Example 1 except that the resin in the ink receiving layer forming paint is changed to acrylic resin: Acronal YJ2770D (resin content 48.5%, acrylic-styrene emulsion, Tg = 43 ° C., manufactured by BASF Japan Ltd.) An inkjet print was produced in the same manner as in the above.
The evaluation results of the obtained ink jet printed matter are shown in Table 1.
Further, the relationship between the substrate surface temperature and the line width at the time of ink jet is shown in FIG.

Comparative Example 3
An inkjet print was produced in the same manner as in Example 1 except that the fine particle content in the ink receiving layer-forming paint was changed to be 15% by mass with respect to the non-volatile component in the paint.
The evaluation results of the obtained ink jet printed matter are shown in Table 1.
Further, the relationship between the substrate surface temperature and the line width at the time of ink jet is shown in FIG.

Comparative Example 4
An inkjet print was produced in the same manner as in Example 1 except that the fine particle content in the ink receiving layer-forming paint was changed to 55% by mass with respect to the non-volatile component in the paint.
The evaluation results of the obtained ink jet printed matter are shown in Table 1.
Further, the relationship between the substrate surface temperature and the line width at the time of ink jet is shown in FIG.

As shown in Table 1 and FIG. 1, all of the inkjet prints obtained in Examples 1 to 3 were capable of obtaining high-quality images. In addition, since the thin line expression and the solid expression are excellent under a wide range of substrate temperature conditions, and the change in line width due to the difference in the substrate temperature is also small, the image quality stability is excellent. There was also no problem with regard to the crackability of the surface of the ink receiving layer.
On the other hand, the ink jet printed matter obtained in Comparative Example 1 was conspicuous in moto ring and streak quality and inferior in solid expression.
Further, as shown in Table 1 and FIG. 2, the inkjet printed material obtained in Comparative Example 2 can express thin lines under the conditions where the substrate surface temperature is set to 60 ° C. or 80 ° C. When the surface temperature was set to 25 ° C., the line width was large and inferior to thin line expression. That is, in the inkjet printed material obtained in Comparative Example 2, the image quality was affected by the substrate surface temperature at the time of inkjet, and the image quality stability at the time of production was inferior.
In addition, the ink jet printed matter obtained in Comparative Example 3 had a noticeable moto ring and was inferior in solid expression. Comparative Example 3 is a thin line representation similar to that of Example 2 in thin line representation, but is inferior to solid representation as compared with Example 2. As the reason, in Example 2, it is considered that the ink is uniformly spread by the action of the fine particles in the formed ink receiving layer (capillary phenomenon and the like), and the occurrence of moto ring can be suppressed. On the other hand, in Comparative Example 3, the content of the fine particles is small, the action of the fine particles can not be sufficiently obtained, and the wetting and spreading of the ink is insufficient, and it is considered that motoring has occurred.
Further, in the ink jet printed matter obtained in Comparative Example 4, since the ink penetrated in the depth direction at the time of applying the ink due to the occurrence of the crack on the surface of the ink receiving layer, the ink did not sufficiently wet and spread. The quality was noticeable and inferior to solid expression.

Claims (2)

A substrate, formed on the substrate, and an ink-receiving layer composed of ink-receiving layer formed coating is formed on the ink-receiving layer, and an ink jet printing layer formed me by the ultraviolet curable ink ,
The base material is any of a ceramic siding plate, a metal siding plate, and a slate plate,
The dry coating amount of the ink receiving layer forming paint is 10 to 200 g / m ² ,
The ink receiving layer forming paint contains an acrylic resin and fine particles,
The calculated Tg of the acrylic resin is in the range of -5 to 30 ° C,
The content of the fine particles is 20 to 50% by mass with respect to the non-volatile component in the paint,
The fine particles are calcium carbonate having a porous shape,
The UV curable ink is eroded in the depth direction of the ink receiving layer, and is blurred by calcium carbonate having the porous shape contained in the ink receiving layer,
The ultraviolet curable ink contains a reactive monomer, a reactive oligomer, a photopolymerization initiator, and a pigment,
The reactive monomer is a group consisting of 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate and 1,9-nonanediol diacrylate At least one selected from
The inkjet print, wherein the reactive oligomer is at least one selected from the group consisting of urethane acrylate, polyester acrylate, epoxy acrylate, silicon acrylate and polybutadiene acrylate . (1) applying an ink receiving layer forming paint on a substrate to form an ink receiving layer;
(2) After the step (1), a step of applying an ink jet print using a UV curable ink,
(3) (2) after the step, and curing the ultraviolet curable ink by ultraviolet radiation, consist,
The base material is any of a ceramic siding plate, a metal siding plate, and a slate plate,
The ink-receiving layer forming coating comprises a A acrylic resin and fine particles,
The calculated Tg of the acrylic resin is −5 to 30 ° C. ,
The content of the fine particles is 20 to 50% by mass against the nonvolatile component in the paint,
The fine particles, Ri calcium carbonate der having a porous shape,
The ultraviolet curable ink contains a reactive monomer, a reactive oligomer, a photopolymerization initiator, and a pigment,
The reactive monomer is a group consisting of 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate and 1,9-nonanediol diacrylate At least one selected from
The reactive oligomer is at least one selected from the group consisting of urethane acrylate, polyester acrylate, epoxy acrylate, silicon acrylate and polybutadiene acrylate,
In the step (2), the UV curable ink is eroded in the depth direction of the ink receiving layer, and the UV curable ink landed on the ink receiving layer by calcium carbonate having the porous shape. A method for producing an ink jet print , comprising the step of bleeding .

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