JP2024038664A - Coated body - Google Patents

Abstract

To provide a coated body which is excellent in color reproducibility, and can express an image having high sharpness such as a red brick tone pattern.SOLUTION: A coated body includes a base material, and a decorative layer, wherein a surface where the decorative layer is printed has an L* value in a CIE(1976)L*a*b* color space of 40.0 to 98.0, the decorative layer is formed of a plurality of ink containing cyan ink, yellow ink and magenta ink, and the cyan ink contains a white pigment.SELECTED DRAWING: None

Description

The present invention relates to a coated body, and particularly to a coated body that has excellent color reproducibility and is capable of expressing highly sharp images such as a red brick pattern.

In recent years, with the development of printing technology, there has been an increasing demand for printing technology to be applied not only to paper and film, but also to a variety of media and applications, such as three-dimensional objects and outdoor applications. Various printing techniques are also used for exterior building materials.

International Publication No. 2002/100652 (Patent Document 1) describes an invention related to a method for producing inkjet printed matter for outdoor applications such as building walls, outdoor signboards, road signs, and car bodies. After forming a white base coating layer (I) using a white paint containing silica fine particles with an oil absorption of 10 to 400 ml/100 g and a pigment volume concentration of 5 to 90%, An invention of a method for producing an inkjet printed matter, characterized in that a printing layer (II) is formed by an inkjet method using an aqueous ink composition, and a clear coat layer (III) is further formed thereon using a clear paint. Describe it. In Patent Document 1, the formation of the white base coating layer (I) prevents the ink from bleeding and improves the fixing state of the ink, and furthermore, the printing density with the aqueous ink composition increases, resulting in improved color development and finish. It is stated that not only can a printing layer (II) with an excellent appearance be formed, but also an inkjet printed matter with excellent weather resistance etc. can be obtained by providing a clear coat layer (III).

JP 2013-142242A (Patent Document 2) discloses a building board in which an image base layer and an ultraviolet curable ink image layer are sequentially formed on a base material, and the image base layer includes a colored pigment. and porous particles having a specific average particle diameter, BET specific surface area, and oil absorption amount are included in a ratio (volume ratio) of porous particles: colored pigment = 2.5 to 6:1, and An invention of a building board characterized in that the total content of the porous particles and the colored pigment in the geological formation is 15 to 40% (volume concentration) is described. Patent Document 2 states that the image base layer can exhibit excellent wettability and fixability of ultraviolet curable ink, and according to the invention described in Patent Document 2, the image base layer is free from streaks and whitening. It is stated that a building board with a clear image can be provided.

JP 2016-68405A (Patent Document 3) discloses an ink-receiving layer forming paint containing at least an acrylic resin and fine particles, in which the calculated Tg of the acrylic resin is in the range of -5 to 30°C, An invention of an ink-receiving layer-forming paint is described, wherein the content of the fine particles is 20 to 50% by mass based on the nonvolatile components in the paint. Patent Document 3 discloses that such an ink-receiving layer-forming paint is capable of forming an image with good image quality without being affected by the substrate surface temperature in inkjet printing using ultraviolet curable ink. It is described that it is an ink-receiving layer-forming coating material that can form an ink-receiving layer.

JP 2017-115434A (Patent Document 4) discloses a base material, an ink-receiving layer formed on the base material, an ink layer formed on the ink-receiving layer, and a base material so as to cover at least the ink layer. A building board comprising a clear layer formed on the ink-receiving layer, wherein the ink-receiving layer contains a colored pigment, a component (X) consisting of at least one of an extender pigment and a resin bead, and a binder resin, the colored pigment and component (X), the proportion of the colored pigment in the whole is 10.0 to 65.0% by volume, and the ink layer is formed of an ink composition. . Patent Document 4 describes that the color development and color reproducibility of an active energy ray-curable ink composition can be improved by controlling the proportions of colored pigments, extender pigments, and resin beads in the ink-receiving layer.

International Publication No. 2002/100652 Japanese Patent Application Publication No. 2013-142242 Japanese Patent Application Publication No. 2016-68405 Japanese Patent Application Publication No. 2017-115434

Patent Documents 1 to 4 improve the printing technology mainly by the layer on which printing is performed (ink-receiving layer, etc.), but this is not sufficient when printing highly sharp images such as red brick-like patterns, for example. It was difficult to express the color gamut, and color reproducibility was sometimes insufficient.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art described above, and to provide a coated body with excellent color reproducibility and capable of expressing highly sharp images such as red brick-like patterns.

The present inventors believe that in order to improve the color reproducibility of printed matter, it is important to improve the gradation when mixing inks in addition to color development, and have conducted studies on inks. However, it was confirmed that because the visibility of the inks used for printing is not uniform, the gradation when mixing inks becomes low, and the color reproduction area becomes narrow (in other words, the color reproducibility becomes low). did. Specifically, when an ink with low visibility and an ink with high visibility are mixed, a color closer to ink with high visibility will be produced, and the color reproduction range will become narrower. In particular, the visibility of cyan ink is low in the three colors of CMY, cyan (C), magenta (M), and yellow (Y), which causes a decrease in gradation when mixing colors.

Upon further investigation, the present inventors discovered that by adding a white pigment to cyan ink, the visibility of the cyan ink can be improved and the gradation when mixing inks can be improved. Furthermore, when a white pigment is added to the ink, the color development can be improved, and in combination with the brightness (L ^* value) of the printing surface, the color development can be significantly improved. In this way, we discovered that by improving the gradation and color development when mixing inks, it is possible to provide a painted body with excellent color reproducibility and the ability to express highly sharp images such as red brick-like patterns. , we have completed the present invention.

Therefore, the coated body of the present invention is a coated body comprising a base material and a decoration layer, and the surface on which the decoration layer is printed is based on the CIE (1976) L ^* a ^* b ^* color space. L ^* value is 40.0 to 98.0, the decoration layer is formed from a plurality of inks including cyan ink, yellow ink, and magenta ink, and the cyan ink includes a white pigment. It is characterized by a painted body.

In a preferred embodiment of the coated body of the present invention, the yellow ink contains a white pigment.

In another preferred embodiment of the coated body of the present invention, at least one of the plurality of inks is an active energy ray-curable ink containing a polymerizable compound containing alkylene oxide as a constituent unit.

In another preferred embodiment of the coated body of the present invention, the decoration layer is formed from a plurality of dot-shaped inks, and the average dot diameter of the inks is within the range of 70 μm to 250 μm.

In another preferred embodiment of the coated body of the present invention, the coated body further includes an ink-receiving layer, and the surface on which the decoration layer is printed is the surface of the ink-receiving layer.

In another preferred embodiment of the coated body of the present invention, the ink receiving layer contains a crosslinked resin.

According to the present invention, it is possible to provide a coated body with excellent color reproducibility and capable of expressing highly sharp images such as a red brick pattern.

The present invention will be explained in detail below.

The present invention relates to a coated body including a base material and a decorative layer. In this specification, this coated body is also referred to as the "coated body of the present invention."

In this specification, a coated body means a base material on which at least a part of the surface is coated with a decorative layer (specifically, a decorative layer is printed). In the present invention, the decorative layer may be formed directly on the base material, or there may be an additional layer such as an ink receiving layer between the decorative layer and the base material, and the decorative layer may be formed through the additional layer. A layer may be formed on the substrate.

In this specification, a decorative layer refers to a layer whose purpose is to give a design to a base material or to give it a texture different from that of the base material. Here, a design is a shape, pattern, color, or a combination thereof.

In this specification, the term "substrate" refers to an object on which a decorative layer is coated (specifically, a decorative layer is printed).

In this specification, the ink-receiving layer refers to a layer that facilitates ink fixation. For example, when printing a high-definition image on a substrate, it is preferable to form an ink-receiving layer on the substrate and perform printing on the ink-receiving layer.

In the coated body of the present invention, the surface on which the decorative layer is printed has an L ^* value of 40.0 to 98.0 in the CIE (1976) L ^* a ^* b ^* color space, and 50.0 to 98. .0 is preferable. L ^* indicates the lightness of the color; L ^* =0 indicates black, and L ^* =100 indicates white. When the L ^* value of the surface on which the decorative layer is printed is within the range specified above, the color development of the decorative layer can be improved, and in combination with adding a white pigment to the cyan ink described below, It can exhibit excellent color reproducibility. Preferably, the a ^* value is -10.0 to 30.0, and the b ^* value is -25.0 to 40.0.

In this specification, the L ^* value is the correlation amount of lightness calculated by the formula (1) of 4.1 basic coordinates of JIS Z 8781-4:2013, and is calculated by the method or device commonly used in the technical field. For example, it can be measured using a spectrophotometer (eg, eXact, manufactured by X-Rite).

In the coated body of the present invention, when the decorative layer is printed directly on the base material, "the surface on which the decorative layer is printed" refers to the surface of the base material. On the other hand, if there is an additional layer such as an ink-receiving layer between the decorative layer and the base material, and the decorative layer is printed on the base material via the additional layer (in other words, the decorative layer is If the further layer located on the substrate is printed), "the side on which the decorative layer is printed" refers to the surface of the further layer (for example the ink-receiving layer).

If the surface on which the decorative layer is printed is the surface of a further layer (e.g. an ink-receptive layer), the L ^* value of the surface on which the decorative layer is printed is determined by the peeling of the further layer (e.g., the ink-receptive layer) from the substrate. The L ^* value of the further layer (for example the ink-receiving layer) is measured while it remains attached to the substrate without being removed.

If the L ^* value of the base material surface is outside the range of 40.0 to 98.0, adjust the L ^* value of the surface on which the decorative layer is printed by forming an additional layer on the base material surface. can do. Means for adjusting the L ^* value of the further layer within the range specified above include selection of pigment species, adjustment of average dispersed particle size of pigment, adjustment of pigment concentration, use of white pigment, and the like.

In the coated body of the present invention, the decoration layer is formed from a plurality of inks including cyan ink, yellow ink, and magenta ink, where the cyan ink contains a white pigment. By adding a white pigment to the cyan ink, the visibility of the cyan ink can be improved and the gradation when mixing inks can be improved. Note that the visibility of the yellow ink may also be low depending on the type of pigment, and in such cases, it is preferable to add a white pigment to the yellow ink as well. Therefore, in one embodiment of the coated body of the present invention, the cyan ink and the yellow ink contain a white pigment. Furthermore, since color development can be improved by adding a white pigment to the ink, it is preferable to add a white pigment to the yellow ink and/or magenta ink in addition to the cyan ink for the purpose of improving the color development. Therefore, in another embodiment of the coated body of the present invention, the cyan ink, yellow ink, and magenta ink contain a white pigment.

Examples of the white pigment include inorganic pigments such as titanium oxide and zinc sulfide. The amount of white pigment in the ink is, for example, 1 to 25% by mass, preferably 3 to 20% by mass, and more preferably 5 to 15% by mass, based on the total amount of pigments contained in the ink. . If the ratio of the white pigment to the total pigment is too high, it may have an adverse effect on the color tone of the ink. One type of white pigment may be used alone, or two or more types may be used in combination.

As a white pigment, C. I. Pigment White 1, 2, 4, 5, 6, 7, 11, 12, 18, 19, 21, 22, 23, 26, 27, 28, hollow particles, and the like. Among these, C. I. Pigment White 6 etc. are preferably mentioned.

In this specification, visibility means the degree to which a decorative layer can be recognized without being affected by the base material, etc., and generally refers to the degree to which the decorative layer hides the base material, etc. (concealability). The higher the value, the higher the visibility.

In the coated body of the present invention, the decoration layer may be formed from only three colors of ink: cyan ink (Y), magenta ink (M), and yellow ink (Y), but is not limited thereto. Rather, to form a decorative layer, special color inks such as black ink (K), orange ink, green ink, violet ink, light cyan ink, light magenta ink, bright color ink such as metallic or pearl, and even coloring are used. Additional inks such as clear inks not intended for use may also be used.

In the coated body of the present invention, at least one ink among the plurality of inks used to form the decorative layer is preferably an active energy ray-curable ink containing a polymerizable compound containing alkylene oxide as a constituent unit. It is more preferable that all the inks used to form the decorative layer are active energy ray-curable inks containing a polymerizable compound containing alkylene oxide as a constituent unit. By using a polymerizable compound containing alkylene oxide as a structural unit, the wettability of the ink to the printing surface can be improved, and therefore the color development of the decorative layer can be improved. As an example of a polymerizable compound containing alkylene oxide as a constituent unit, a polymerizable compound containing ethylene oxide as a constituent unit has an ether bond containing a structure of -CH ₂ CH ₂ O-, and propylene oxide as a constituent unit. The polymerizable compound contained as has an ether bond containing a structure of -CH ₂ CH(CH ₃ )O- or -CH ₂ CH ₂ CH ₂ O-. Moreover, among the polymerizable compounds containing alkylene oxide as a constitutional unit, there are also polymerizable compounds containing multiple types of alkylene oxides as constitutional units. The amount of the polymerizable compound containing alkylene oxide as a structural unit in the ink is preferably 10 to 90% by mass, more preferably 20 to 85% by mass. The polymerizable compounds containing alkylene oxide as a structural unit may be used alone or in combination of two or more.

In the coated body of the present invention, the decoration layer is preferably formed from a plurality of dot-shaped inks. Thereby, the thickness of the decorative layer can be increased, and the color development of the decorative layer can be further improved. By performing inkjet printing using active energy ray-curable ink, the ink droplets are cured in the form of dots, thereby making it possible to form a decorative layer made of a plurality of dot-shaped inks.

Further, in the coated body of the present invention, when the decorative layer is formed from a plurality of dot-shaped inks, the average dot diameter of the inks is preferably within the range of 70 μm to 250 μm, and preferably within the range of 80 μm to 220 μm. It is more preferably within the range of 90 μm to 190 μm, particularly preferably within the range of 90 μm to 190 μm.

One of the parameters that can control the average dot diameter is the time from when the ink is printed on the printing surface (in other words, after the ink lands on the printing surface) to when the ink starts to harden (in other words, after the ink lands on the printing surface). There is a standing time (hereinafter referred to as "setting time") until the ink that has landed on the printing surface is irradiated with active energy rays. The wetting and spreading of ink or the permeation process changes depending on the setting time, and the longer the setting time, the larger the average dot diameter tends to be.

The average dot diameter here refers to the diameter of the dots when the ink is printed on the printing surface, and the diameter of the dots at five arbitrary locations for each color of ink is measured using a microscope. The average value of the diameters of all dots is defined as the average dot diameter. If the shape of the dot observed with a microscope is not a neat circle but an ellipse, the longest distance between two points on the outer circumference of the dot is determined as the diameter of the dot.

In the coated body of the present invention, the thickness of the decorative layer is, for example, 1 to 70 μm, and preferably 2 to 60 μm from the viewpoint of improving color development.

Next, the ink used to form the decorative layer will be explained. This applies to any ink unless otherwise specified (for example, unless the ink is specified as cyan ink, etc.). In this specification, the ink used to form the decorative layer is also referred to as "decorative layer ink."

The pigment used in the ink for the decorative layer is not particularly limited as long as it is a pigment normally used in inkjet inks, and any known pigment can be used.

The pigment used for cyan ink is C. I. Pigment Blue 1, 15, 15:1, 15:2, 15:3, 15:4, 15:5, 15:6, 16, 17:1, 24, 24:1, 25, 26, 27, 28, 29, 36, 56, 60, 61, 62, 63, 75, 79, 80 and the like.
Among these, preferred pigments are C.I. I. Pigment Blue 15:3, 15:4, 28 and the like.

The pigment used for magenta ink is C. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22, 23, 31, 32, 38, 41, 48, 48:1, 48:2, 48:3, 48:4, 48:5, 49, 52, 52:1, 52:2, 53:1, 54, 57:1, 58, 60: 1, 63, 64:1, 68, 81:1, 83, 88, 89, 95, 101, 104, 105, 108, 112, 114, 119, 122, 123, 136, 144, 146, 147, 149, 150, 164, 166, 168, 169, 170, 171, 172, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 187, 188, 190, 193, 194, 200, 202, 206, 207, 208, 209, 210, 211, 213, 214, 216, 220, 220, 221, 224, 226, 237, 238, 239, 242, 245, 247, 248, 251, 253, 254, 255, 256, 257, 258, 260, 262, 263, 264, 266, 268, 269, 270, 271, 272, 279, 282 and the like.
Among these, preferred pigments are C.I. I. Pigment Red 101 and the like.

The pigment used for yellow ink is C. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 9, 10, 12, 13, 14, 15, 16, 17, 24, 32, 34, 35, 36, 37, 41, 42, 43, 49, 53, 55, 60, 61, 62, 63, 65, 73, 74, 75, 77, 81, 83, 87, 93, 94, 95, 97, 98, 99, 100, 101, 104, 105, 106, 108, 109, 110, 111, 113, 114, 116, 117, 119, 120, 123, 124, 126, 127, 128, 129, 130, 133, 138, 139, 150, 151, 152, 153, 154, 155, 165, 167, 168, 169, 170, 172, 173, 174, 175, 176, 179, 180, 181, 182, 183, 184, 185, 191, 193, 194, 199, 205, 206, 209, 212, 213, 214, 215, 219 and the like.
Among these, preferred pigments are C.I. I. Pigment Yellow 42, 120, 138, 150, 151, 155, 184, 213 and the like.

Without being limited to the preferred pigments mentioned above, other pigments can also be used in the cyan, magenta and yellow inks.

Although both organic pigments and inorganic pigments can be used in the ink for the decorative layer, it is preferable to use inorganic pigments because they have excellent weather resistance.

The amount of pigment in the ink for the decorative layer is, for example, 1 to 25% by weight, preferably 3 to 25% by weight, and more preferably 5 to 20% by weight. If the amount of pigment is small, even if the pigment has excellent hiding properties, it may not be able to exhibit sufficient hiding properties, and there may be problems in color reproducibility. Moreover, if the amount of pigment is large, the hiding power becomes too high, which may cause difficulty in color reproducibility of mixed colors.

Further, as described above, in the present invention, the cyan ink contains a white pigment, and it is preferable that the yellow ink and/or the magenta ink also contain a white pigment. Details of the white pigment are as described above.

The average dispersed particle diameter D50 of the pigment used in the ink for the decorative layer is preferably within the range of 20 to 500 nm, more preferably within the range of 30 to 450 nm, and more preferably within the range of 40 to 400 nm. It is even more preferable that there be.

Further, the average dispersed particle diameter D50 of the white pigment in the cyan ink is preferably within the range of 50 to 400 nm, more preferably within the range of 60 to 350 nm, and even more preferably 70 to 300 nm. . The same applies if the yellow and magenta inks contain white pigments.

In this specification, the average dispersed particle size D50 of the pigment refers to the 50% particle size ( _D50 ) of the volume-based particle size distribution of the pigment dispersed in the ink, and is measured using a particle size distribution measuring device (e.g. laser diffraction/scattering type It can be determined from the particle size distribution measured using a particle size distribution measuring device). The particle size is expressed as a sphere equivalent diameter determined by laser diffraction/scattering method.

The ink for the decorative layer is preferably an ink for printing with a droplet discharge type printing device, and is particularly preferably an inkjet ink, but is not limited to this, and may be used in a gravure printing method or an offset printing method. It is also possible to perform the printing using various printing methods such as , flexo printing method, screen printing method, and coater method.

A droplet ejection type printing device is a printing device that ejects ink droplets from a printing device (particularly a print head) and makes them land on a base material, and includes an inkjet printer and the like. In this specification, inkjet ink means ink used in inkjet printers.

Examples of inkjet printers include inkjet printers that eject ink using a charge control method or a piezo method. Furthermore, large-sized inkjet printers, specifically inkjet printers intended for printing on articles produced on industrial lines, can also be suitably used.

Further, the ink for the decorative layer is preferably an ink that can be cured by irradiation with active energy rays such as ultraviolet rays, visible light, and electron beams. Such ink is generally referred to as "active energy ray curable ink." A plurality of inks (ink set) including active energy ray curable inks may be referred to as an "active energy ray curable ink set."

The decoration layer ink preferably contains a polymerizable compound and a photopolymerization initiator.

A polymerizable compound undergoes a polymerization reaction via a functional group exhibiting radical polymerizability (for example, a photopolymerizable unsaturated group such as a carbon-carbon double bond constituting an acryloyl group, a methacryloyl group, a vinyl group, or an allyl group). It is a compound that causes A carbon-carbon double bond exhibiting radical polymerizability is also referred to as an "ethylenic unsaturated double bond." The polymerizable compounds may be used alone or in combination of two or more.

Polymerizable compounds are classified as monofunctional polymerizable compounds or polyfunctional polymerizable compounds. Here, the monofunctional polymerizable compound includes a monofunctional polymerizable monomer having one functional group exhibiting radical polymerizability (for example, a monofunctional polymerizable monomer having one polymerizable unsaturated group) and a monofunctional polymerizable monomer having one functional group exhibiting radical polymerizability. Examples include monofunctional polymerizable oligomers having one functional group (for example, monofunctional polymerizable oligomers having one polymerizable unsaturated group). Examples of polyfunctional polymerizable compounds include polyfunctional polymerizable monomers that have two or more functional groups that exhibit radical polymerizability (e.g., polyfunctional polymerizable monomers that have two or more polymerizable unsaturated groups), and those that exhibit radical polymerizability. Examples include polyfunctional polymerizable oligomers having two or more functional groups (for example, polyfunctional polymerizable oligomers having two or more polymerizable unsaturated groups).

In the ink for the decorative layer, when the amount (mass %) of the monofunctional polymerizable compound contained in the ink is A, and the amount (mass %) of the polyfunctional polymerizable compound contained in the ink is 0, It is preferable that .01≦B/A≦0.50 and 30% by mass≦A+B≦95% by mass. In an ink in which the total amount of polymerizable compounds is 30 to 95% by mass, by setting the ratio of polyfunctional polymerizable compounds to monofunctional polymerizable compounds to 0.50 or less, curing shrinkage of the film can be suppressed, and the film It can improve its adhesion. This makes it possible to ensure adhesion to various base materials and coatings. Furthermore, by setting the amounts of the monofunctional polymerizable compound and the polyfunctional polymerizable compound contained in the ink at the ratios specified above, curability and film strength can be ensured. Here, B/A is preferably 0.01 to 0.40. Furthermore, A+B is preferably 40 to 95% by mass.

The polymerizable compound contained in the ink preferably has an average number of functional groups of 1.25 or less, more preferably 1.01 to 1.25. In order to reduce the number of reaction points in the entire system to suppress curing shrinkage and provide an appropriate crosslinked structure to ensure film strength, we investigated the optimal number of reaction points and crosslinking density, and found that the polymerization contained in the ink When the average number of functional groups of the functional compound is 1.25 or less, especially 1.01 to 1.25, it is highly effective in suppressing curing shrinkage of the film, greatly improving the adhesion of the film itself, and increasing the film strength. can be retained. This makes it possible to ensure adhesion and film strength to various substrates and coatings.

In this specification, the average number of functional groups of the polymerizable compound contained in the ink can be calculated as follows.
Average number of functional groups = [total number of ethylenically unsaturated double bonds contained in the polymerizable compound] / [total number of molecules of the polymerizable compound] ... Calculation formula (1)
Here, regarding the "total number of ethylenically unsaturated double bonds contained in the polymerizable compound" in calculation formula (1), the number of ethylenically unsaturated double bonds per molecule of the polymerizable compound is It is calculated by multiplying the total number of molecules of the compound. When multiple types of polymerizable compounds are blended into the ink, calculate the number of ethylenically unsaturated double bonds for each type, and calculate the total number of ethylenically unsaturated double bonds. To tell.
(Example of how to determine the average number of functional groups of a polymerizable compound)
The total amount of the polymerizable compound is 100 parts by mass.
Polymerizable compound A: Number of ethylenically unsaturated double bonds = 1, molecular weight X _A , 30 parts by mass Polymerizable compound B: Number of ethylenically unsaturated double bonds = 2, molecular weight X _B , 70 parts by mass Average number of functional groups = {(1×30/X _A )+(2×70/X _B )}/{(30/X _A )+(70/X _B )}

In order to adjust the average number of functional groups to 1.01 to 1.25, it is useful to use a polyfunctional polymerizable compound having a large ethylenically unsaturated double bond equivalent. The ethylenically unsaturated double bond equivalent is the value obtained by dividing the molecular weight by the number of ethylenically unsaturated double bonds contained in one molecule. When the ethylenically unsaturated double bond is derived from a (meth)acryloyl group, it is also referred to as "acrylic equivalent". Generally, the larger this value is, the wider the distance between crosslinking points is and the lower the crosslinking density, which can contribute to reducing curing shrinkage as a result.

The polymerizable compound contained in the ink preferably contains 40 to 90% by mass of a monofunctional polymerizable compound. When the amount of the monofunctional polymerizable compound is 40% by mass or more based on the entire polymerizable compound, adhesion and flexibility can be improved. Furthermore, if the proportion of the monofunctional polymerizable compound is too high, the film strength and curability will decrease, so the proportion of the monofunctional polymerizable compound to the total polymerizable compound is preferably 90% by mass or less.

The polymerizable compound contained in the ink preferably contains 0.1 to 40% by weight, particularly 0.1 to 30% by weight of a bifunctional polymerizable compound having a molecular weight of 200 to 1,800. From the viewpoint of achieving both adhesion and curability, it is preferable to use a polymerizable compound having two functional groups exhibiting radical polymerizability (bifunctional polymerizable compound). Further, from the viewpoint of suppressing curing shrinkage, it is preferable to use a polymerizable compound having a relatively high molecular weight, and the molecular weight of the bifunctional polymerizable compound is preferably 200 to 1,800, more preferably 200 to 1,500. More preferably, the amount of the bifunctional polymerizable compound having a molecular weight of 200 to 1,800 is 0.1 to 25% by mass based on the entire polymerizable compound.

In the present specification, when the polymerizable compound is an oligomer, its molecular weight can be measured as a polystyrene-equivalent weight average molecular weight measured by gel permeation chromatography.

Examples of the bifunctional polymerizable compound include bifunctional polymerizable monomers and bifunctional polymerizable oligomers. The amount of the bifunctional polymerizable compound in the ink is preferably 0.1 to 40% by weight, more preferably 0.1 to 30% by weight.

It is preferable that the ink for the decorative layer contains a polymerizable compound having a heterocyclic skeleton. By using a polymerizable compound having a heterocyclic skeleton, curability can be improved. Further, the polymerizable compound having a heterocyclic skeleton is preferably a nitrogen-containing polymerizable compound, and more preferably a polymerizable compound whose heterocyclic skeleton contains a nitrogen atom. In particular, a nitrogen-containing polymerizable compound as a polymerizable compound having a heterocyclic skeleton is highly effective in reducing polymerization inhibition caused by oxygen during curing, and can improve the curability of the ink. The amount of the polymerizable compound having a heterocyclic skeleton in the ink is preferably 0.1 to 20% by mass.

It is preferable that the ink for the decorative layer contains a polymerizable compound having a hydroxyl group. By using a polymerizable compound having a hydroxyl group, adhesion to the substrate and film strength can be improved by hydrogen bonds and chemical bonds via the hydroxyl group. Furthermore, like the polymerizable compound having a heterocyclic skeleton, it has the effect of reducing oxygen inhibition during curing, and can be expected to improve curability. Further, in one embodiment of the present invention, the ink contains at least one of a polymerizable compound having a hydroxyl group and a silane compound described below, and preferably contains both a polymerizable compound having a hydroxyl group and a silane compound. The amount of the polymerizable compound having a hydroxyl group in the ink is preferably 0.1 to 20% by mass.

〔構造式（１）中、ｎは１～３であり、Ｙはメトキシ基またはエトキシ基であり、ＲはＣ３より選ばれるアルキレン基であり、Ｚは（メタ）アクリロキシ基である。〕 The decoration layer ink preferably contains a polymerizable compound having a silicon atom, and more preferably contains a polymerizable compound represented by the following structural formula (1). By using a polymerizable compound having a silicon atom as the silane compound, adhesion to the base material can be improved. In particular, the polymerizable compound represented by Structural Formula (1) is excellent in the effect of improving adhesion. In the ink, the amount of the polymerizable compound having a silicon atom is preferably 0.1 to 20% by mass.

[In structural formula (1), n is 1 to 3, Y is a methoxy group or ethoxy group, R is an alkylene group selected from C3, and Z is a (meth)acryloxy group. ]

The polymerizable compound is P. I. I. Preferably, the weighted average of the values is less than 2.00. P. I. I. is an abbreviation for Primary Irritation Index, which is translated as primary skin irritation index. The higher the primary skin irritation (P.I.I.), the more chemical irritation is caused to the skin, and the more likely symptoms such as rash will occur. This can make the work environment and personnel dangerous and difficult to handle. Furthermore, monomers that are highly irritating to the primary skin may remain in the film even after the curing process, which may pose a problem. Therefore, P. I. I. A safe ink design with low oxidation is desired. The Antibacterial Products Technology Association (SIAA) lists no irritation or mild irritation (P.I.I. (Primary Irritation Index): less than 2.00) as a safety standard. It is being

P of the polymerizable compound. I. I. The method for calculating the weighted average of values is as follows.
Polymerizable compound A: P. I. I. =P _A , mass ratio = T _A
Polymerizable compound B: P. I. I. = P _B , mass ratio = T _B
P. I. I. Weighted average of = P _A × T _A + P _B × T _B ...Formula (2)

Specific examples of monofunctional polymerizable monomers include isoamyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, and tridecyl (meth)acrylate. ) acrylate, stearyl (meth)acrylate, 2-ethylhexyl-diglycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, ethyl carbitol (meth)acrylate, 2-(2'-vinyloxyethoxy)ethyl (meth)acrylate ) acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 4- t-Butylcyclohexyl (meth)acrylate, cyclohexyl (meth)acrylate, N-(meth)acryloylmorpholine, tetrahydrofurfuryl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl) Methyl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, γ-butyrolactone (meth)acrylate, N-vinylcaprolactam, N-(meth)acryloyloxyethylhexahydrophthalimide, 1-(meth)acryloylpyrrolidine- 2-one, 1-(meth)acryloylpiperidin-2-one, N-vinyl-2-pyrrolidone, N-vinylimidazole, dimethylacrylamide, hydroxyethyl(meth)acrylamide, diethylacrylamide, isopropylacrylamide, dimethylaminopropyl(meth) ) acrylamide, diacetone acrylamide, Nn-butoxymethylacrylamide, N-isobutoxymethylacrylamide, N-methoxymethylacrylamide, N-methylolacrylamide, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, benzyl (meth)acrylate ) acrylate, neopentyl glycol (meth)acrylic acid benzoate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, γ- (meth)acryloxypropyltrimethoxysilane, γ-(meth)acryloxypropyltriethoxysilane, γ-(meth)acryloxypropylmethyldimethoxysilane, γ-(meth)acryloxypropylmethyldiethoxysilane, γ-( Meta)acryloxypropylmethyldipropoxysilane, γ-(meth)acryloxybutylphenyldimethoxysilane, γ-(meth)acryloxypropyldimethylmethoxysilane, γ-(meth)acryloxypropyldiethylmethoxysilane β-(meth) Acryloxyethyltrimethoxysilane, β-(meth)acryloxyethyltriethoxysilane, polyoxyethylene mono(meth)acrylate, polyoxypropylene mono(meth)acrylate, polyoxybutylene mono(meth)acrylate, etc. Examples include those modified with alkylene glycol. Among these, monofunctional polymerizable monomers with extended alkyl chains or alkylene glycol chains are preferable because odor is reduced due to increased molecular weight compared to before chain extension. In this specific example, polymerizable compounds containing alkylene oxide as a constituent unit are modified with polyoxyethylene mono(meth)acrylate, polyoxypropylene mono(meth)acrylate, polyoxybutylene mono(meth)acrylate, or alkylene glycol. It is a monofunctional polymerizable monomer.

Among polyfunctional polymerizable monomers, specific examples of polyfunctional polymerizable monomers (bifunctional polymerizable monomers) having two radically polymerizable functional groups include 1,3-butylene glycol di(meth)acrylate, 1 , 4-butanediol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,7-heptanediol di(meth)acrylate, 1,8 -Octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, 2-butyl-2 -Ethyl-1,3-propanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 2-methyl-1,8-octanediol di(meth)acrylate, diethylene glycol di( meth)acrylate, dipropylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, hydroxy Neopentyl glycol di(meth)acrylate pivalate, PO (propylene oxide) modified neopentyl glycol di(meth)acrylate, cyclohexanedimethanol diacrylate, tricyclodecane dimethanol di(meth)acrylate, dimethylol-tricyclodecane di(meth)acrylate , dicyclopentanyl diacrylate, bisphenol A di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, and the like. In this specific example, the polymerizable compounds containing alkylene oxide as a constitutional unit include diethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, and tripropylene glycol di(meth)acrylate. ) acrylate, tetraethylene glycol di(meth)acrylate, PO (propylene oxide) modified neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and polytetramethylene glycol di(meth)acrylate, meth)acrylate.

Specific examples of polyfunctional polymerizable monomers having three or more functional groups exhibiting radical polymerizability (trifunctional or higher functional polyfunctional polymerizable monomers) include trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri( meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, ethoxylated glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, EO-modified diglycerin tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, EO-modified dipentaerythritol hexa(meth)acrylate, glycerin triacrylate Examples include (meth)acrylate. In this specific example, the polymerizable compounds containing alkylene oxide as a constituent unit include ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, ethoxylated glycerin tri(meth)acrylate, These are ethoxylated pentaerythritol tetra(meth)acrylate, EO-modified diglycerin tetra(meth)acrylate, and EO-modified dipentaerythritol hexa(meth)acrylate.

As used herein, the term (meth)acrylate means methacrylate or acrylate. For example, 2-hydroxyethyl (meth)acrylate is 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate. In addition, when a prefix indicating plurality is attached to a (meth)acrylate, such as di(meth)acrylate, tri(meth)acrylate, etc., each (meth)acrylate may be the same or different. good. Further, (meth)acrylic acid means acrylic or methacrylic acid, and (meth)acrylamide means acrylamide or methacrylamide.

The polymerizable oligomer is preferably an acrylic oligomer. An acrylic oligomer is an oligomer having an acryloyl group or a methacryloyl group as a functional group exhibiting radical polymerizability.

The polymerizable oligomer is preferably a polyfunctional polymerizable oligomer, more preferably a polyfunctional acrylic oligomer. The number of functional groups in the polymerizable oligomer is preferably 2 to 6, and the molecular weight of the polymerizable oligomer is preferably 800 to 20,000. The molecular weight of the polymerizable oligomer is the weight average molecular weight in terms of polystyrene.

Specific examples of acrylic oligomers include polyurethane acrylic oligomers [acrylic oligomers with multiple urethane bonds (-NHCOO-)], polyester acrylic oligomers [acrylic oligomers with multiple ester bonds (-COO-)], polyamino acrylic oligomers [amino group (-NH ₂ )], polyepoxy acrylic oligomer [acrylic oligomer having multiple epoxy groups], silicone acrylic oligomer [acrylic oligomer having multiple siloxane bonds (-SiO-)], polybutadiene acrylic oligomer [butadiene unit] Acrylic oligomers having multiple .

Additionally, the following are known as acrylic oligomers.
Beam set 502H, beam set 505A-6, beam set 550B, beam set 575, beam set AQ-17 (manufactured by Arakawa Chemical Industries),
AH-600, UA-306H, UA-306T, UA-306I, UA-510H, UF-8001G (manufactured by Kyoeisha Chemical Co., Ltd.),
CN910, CN959, CN963, CN964, CN965NS, CN966NS, CN969NS, CN980NS, CN981NS, CN982, CN983NS, CN985, CN991NS, CN996NS, CN2920, CN2921, CN8881NS, CN8883NS, CN9001NS, CN9004, CN9005, CN9009, CN9011, CN9021NS, CN9023, CN9028, CN9030, CN9178NS, CN9290, CN9893NS, CN929, CN989NS, CN968NS, CN9006NS, CN9010NS, CN9025, CN9026, CN9039, CN9062, CN9110NS, CN9029, CN8885NS, CN9013NS, CN973, CN978NS, CN992, CN9167, CN9782, CN9783, CN970, CN971, CN972, CN975NS, CN9165 (manufactured by Sartomer),
U-2PPA, U-6LPA, U-10HA, U-10PA, UA-1100H, U-15HA, UA-53H, UA-33H, U-200PA, UA-200PA, UA-160TM, UA-290TM, UA- 4200, UA-4400, UA-122P (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.),
New Frontier R-1235, R-1220, RST-201, RST-402, R-1301, R-1304, R-1214, R-1302XT, GX-8801A, R-1603, R-1150D (Daiichi Kogyo Seiyaku company),
EBECRYL204, EBECRYL205, EBECRYL210, EBECRYL215, EBECRYL220, EBECRYL230, EBECRYL244, EBECRYL245, EBECRYL264, EBECRYL265, EBECRYL270, EB ECRYL280/15IB, EBECRYL284, EBECRYL285, EBECRYL294/25HD, EBECRYL1259, EBECRYL1290, KRM8200, EBECRYL4820, EBECRYL4858, EBECRYL5129, EBECR YL7100, EBECRYL8210, EBECRYL8254, EBECRYL8301R, EBECRYL8307, EBECRYL8402, EBECRYL8405, EBECRYL8411, EBECRYL8465, EBECRYL8800, EBECRYL8804, EBECRYL8807, EB ECRYL9260, EBECRYL9270, EBECRYL7735, EBECRYL8296, EBECRYL8452, EBECRYL8904, EBECRYL8311, EBECRYL8701, EBECRYL8667 (manufactured by Daicel Allnex),
UV-1700B, UV-6300B, UV-7550B, UV-7600B, UV-7605B, UV-7610B, UV-7630B, UV-7640B, UV-7650B, UV-6630B, UV-7000B, UV-7510B, UV- 7461TE,
UV-2000B, UV-2750B, UV-3000B, UV-3200B, UV-3300B, UV-3310B, UV-3700B, UV6640B (manufactured by Nippon Gosei Kagaku Co., Ltd.),
Art Resin UN-333, UN-350, UN-1255, UN-2600, UN-2700, UN-5590, UN-6060PTM, UN-6200, UN-6202, UN-6300, UN-6301, UN-7600, UN-7700, UN-9000PEP, UN-9200A, UN-3320HA, UN-3320HC, UN-904, UN-906S (manufactured by Negami Kogyo Co., Ltd.),
Aronix M-6100, M-6250, M-6500, M-7100, M-7300K, M-8030, M-8060, M-8100, M-8530, M-8560, M-9050 (manufactured by Toagosei Co., Ltd.)

Specific examples of polymerizable compounds having hydroxyl groups include 2-hydroxyethyl (meth)acrylate, 2-hydroxykipropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6 - Hydroxyhexyl (meth)acrylate, polyoxyethylene mono(meth)acrylate, polyoxypropylene mono(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, caprolactone-modified hydroxyethyl acrylate, etc. Can be mentioned. In addition, the polymerizable compound having a hydroxyl group also includes a polymerizable compound that generates a hydroxyl group by thermal decomposition, such as N-methylolacrylamide. Further, as the polymerizable compound having a hydroxyl group, a synthesized compound or a commercially available product may be used.

Specific examples of polymerizable compounds having silicon atoms include γ-(meth)acryloxypropyltrimethoxysilane, γ-(meth)acryloxypropyltriethoxysilane, β-(meth)acryloxyethyltrimethoxysilane, β -(meth)acryloxyethyltriethoxysilane, γ-(meth)acryloxypropylmethyldimethoxysilane, γ-(meth)acryloxypropylmethyldiethoxysilane, γ-(meth)acryloxypropylmethyldipropoxysilane, γ -(meth)acryloxybutylphenyldimethoxysilane, γ-(meth)acryloxypropyldimethylmethoxysilane, γ-(meth)acryloxypropyldiethylmethoxysilane, and the like. Among these, examples of the polymerizable compound represented by structural formula (1) include γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, and γ-methacryloxypropyldimethylmethoxysilane. It will be done.

Specific examples of polymerizable compounds having a heterocyclic skeleton include N-acryloylmorpholine, N-methacryloylmorpholine, γ-butyrolactone (meth)acrylate, N-vinylcaprolactam, N-acryloyloxyethylhexahydrophthalimide, N-methacryloyloxy Ethylhexahydrophthalimide, 1-acryloylpyrrolidin-2-one, 1-methacryloylpyrrolidin-2-one, 1-acryloylpiperidin-2-one, 1-methacryloylpiperidin-2-one, N-vinyl-2-pyrrolidone, N - Vinylimidazole, tetrahydrofurfuryl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, etc. It will be done. Among these, those containing nitrogen are preferred, and N-acryloylmorpholine is particularly preferred.

The photopolymerization initiator has the effect of starting the polymerization of the above-described polymerizable compound when irradiated with active energy rays. The amount of photopolymerization initiator in the ink is preferably 1 to 15% by weight, more preferably 1 to 12% by weight, and even more preferably 1 to 10% by weight. If the content of the polymerization initiator is less than 1% by mass, the film may be poorly cured, and if it exceeds 15% by mass, precipitates may be generated at low temperatures, making ink ejection unstable. Furthermore, in order to accelerate the initiation reaction of the polymerization initiator, it is also possible to use an auxiliary agent such as a photosensitizer.

Examples of photopolymerization initiators include benzophenone compounds, acetophenone compounds, thioxanthone compounds, and acylphosphine oxide compounds. It is preferable that the wavelengths overlap as much as possible. In particular, the photopolymerization initiator preferably contains an acylphosphine oxide initiator from the viewpoint of coloring during curing and curability when forming a thick film. The photopolymerization initiators may be used alone or in combination of two or more.

Regarding the photopolymerization initiator, it is preferable to use two or more types of initiators having different wavelength ranges. Thereby, the polymerizability of the compound can be improved. In addition, by combining those with two cleavage points and those with one cleavage point, the starting radical concentration can be increased, and the polymerization property and degree of curing can be further improved.

As the acylphosphine oxide initiator, it is preferable to use a monoacylphosphine oxide initiator and a bisacylphosphine oxide initiator in combination. Here, the mass ratio (C:D) of the monoacylphosphine oxide initiator (C) and the bisacylphosphine oxide initiator (D) is particularly preferably from 1:1 to 5:1.

Specific examples of photopolymerization initiators include:
2,2-dimethoxy-1,2-diphenylethan-1-one,
1-hydroxy-cyclohexyl-phenyl-ketone,
2-hydroxy-2-methyl-1-phenylpropan-1-one,
Benzophenone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy- 2-Methylpropionyl)-benzyl]-phenyl}-2-methyl-propan-1-one, phenylglyoxylic acid methyl ester, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane -1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone, 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholine-4 -yl-phenyl)-butan-1-one, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 1,2-octanedione, 1-[4-(phenylthio)-2-(O-benzoyloxime)], ethanone, 1-[9- Examples include ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-,1-(O-acetyloxime), 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, etc. .

Among these, from the viewpoint of ink curability, 2,2-dimethoxy-1,2-diphenylethan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone, Bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl -phosphine oxide and 2,4-diethylthioxanthone are preferable, and from the viewpoint of coloration during curing and curability when forming a thick film, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, (2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide are preferred, with 2,4,6-trimethylbenzoyl-diphenyl - Particular preference is given to phosphine oxide.

〔構造式（２）中、ｎは１～３であり、Ｙはメトキシ基またはエトキシ基であり、ＲはＣ３より選ばれるアルキレン基であり、Ｘはグリシドキシ基またはエポキシシクロヘキシル基である。〕
なお、エポキシシクロヘキシル基とは、シクロヘキシル環を構成する２つの炭素原子と酸素原子でエポキシ基を形成しているシクロヘキシル基であり、エポキシ環とシクロヘキシル環の縮合環構造を有する基である。 The ink for the decorative layer preferably contains a silane coupling agent, and more preferably contains a silane coupling agent represented by the following structural formula (2). By using a silane coupling agent as the silane compound, it is possible to improve adhesion to the substrate. In addition, the silane compound represented by structural formula (2) is also excellent in pigment dispersibility, and can improve the storage stability of the ink. In the ink, the amount of the silane coupling agent is preferably 0.1 to 20% by mass. The silane coupling agent may be used alone or in combination of two or more types.

[In the structural formula (2), n is 1 to 3, Y is a methoxy group or an ethoxy group, R is an alkylene group selected from C3, and X is a glycidoxy group or an epoxycyclohexyl group.]
The epoxycyclohexyl group is a cyclohexyl group in which an epoxy group is formed by two carbon atoms and an oxygen atom that constitute a cyclohexyl ring, and is a group having a condensed ring structure of an epoxy ring and a cyclohexyl ring.

Specific examples of silane coupling agents include glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, and γ-glycidoxysilane. Xypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyldimethylmethoxysilane, γ-glycidoxypropyldimethylmethoxysilane Sidoxypropyl(ethyl)dimethoxysilane, β-3,4-epoxycyclohexylethyltrimethoxysilane, β-3,4-epoxycyclohexylethyltriethoxysilane, 8-glycidoxyoctyltrimethoxysilane, 8-glycidoxy Epoxy group-containing silane coupling agents such as octylmethyldimethoxysilane and 8-glycidoxyoctylmethyldiethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane , N-β-(aminoethyl)-γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, N-β-(aminoethyl)-γ-aminopropyltriethoxysilane Isopropoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltrimethoxysilane, γ-anilinopropyltrimethoxysilane, γ-ureidopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane Methoxysilane, N-vinylbenzyl-γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-8-aminooctyltrimethoxysilane, γ-triethoxysilyl-N-(1,3-dimethyl-butylidene) Examples include amino group-containing silane coupling agents such as propylamine.

Among these, as the silane coupling agent represented by structural formula (2), γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyldimethylmethoxy Examples include silane.

It is preferable that the ink for the decorative layer contains a silane compound. By using a silane compound, the adhesion to the substrate and the dispersibility of the pigment can be improved. In one embodiment of the present invention, the ink contains at least one of a silane compound and the aforementioned polymerizable compound having a hydroxyl group, and preferably contains both the silane compound and the polymerizable compound having a hydroxyl group. In the ink, the amount of the silane compound is preferably 0.1 to 20% by mass. The silane compounds may be used alone or in combination of two or more.

Examples of the silane compound include a polymerizable compound having a silicon atom, preferably a polymerizable compound represented by Structural Formula (1), a silane coupling agent, and preferably a silane coupling agent represented by Structural Formula (2). etc.

The ink for the decorative layer preferably contains at least one of a polymerizable compound represented by Structural Formula (1) and a silane coupling agent represented by Structural Formula (2) as a silane compound; ) It is more preferable to include both the polymerizable compound represented by formula (2) and the silane coupling agent represented by structural formula (2). When the polymerizable compound represented by Structural Formula (1) and the silane coupling agent represented by Structural Formula (2) are used together, the polymerizable compound (E) represented by Structural Formula (1) and the Structural Formula ( The mass ratio (E:F) to the silane coupling agent (F) represented by 2) is particularly preferably from 1:2 to 2:1.

The ink for the decorative layer may further contain a dispersant, if necessary, in order to disperse the pigment. The content of the dispersant is, for example, 0.1 to 5% by mass in the ink. Dispersants may be used alone or in combination of two or more.

The dispersant preferably contains a dispersant having a base value of 30 to 70 mgKOH/g and/or an acid value of 10 to 150 mgKOH/g. By using a dispersant having such a base value and/or acid value, the dispersion stability of the pigment can be improved.

In this specification, "base value" is also referred to as "amine value", and is equivalent to milligrams of potassium hydroxide equivalent to hydrochloric acid or perchloric acid required to neutralize the basic component contained in 1 g of sample. number (unit: mgKOH/g), and can be measured by the method specified in JIS K2501:2003. In addition, "acid value" refers to the number of milligrams of potassium hydroxide (unit: mgKOH/g) required to neutralize the acidic components present in 1 g of sample, and is defined in JIS K2501:2003. It can be measured by

Specific examples of pigment dispersants include:
ANTI-TERRA-U, ANTI-TERRA-U100,
ANTI-TERRA-204, ANTI-TERRA-205,
DISPERBYK-101, DISPERBYK-102,
DISPERBYK-103, DISPERBYK-106,
DISPERBYK-108, DISPERBYK-109,
DISPERBYK-110, DISPERBYK-111,
DISPERBYK-112, DISPERBYK-116,
DISPERBYK-130, DISPERBYK-140,
DISPERBYK-142, DISPERBYK-145,
DISPERBYK-161, DISPERBYK-162,
DISPERBYK-163, DISPERBYK-164,
DISPERBYK-166, DISPERBYK-167,
DISPERBYK-168, DISPERBYK-170,
DISPERBYK-171, DISPERBYK-174,
DISPERBYK-180, DISPERBYK-182,
DISPERBYK-183, DISPERBYK-184,
DISPERBYK-185, DISPERBYK-2000,
DISPERBYK-2001, DISPERBYK-2008,
DISPERBYK-2009, DISPERBYK-2020,
DISPERBYK-2025, DISPERBYK-2050,
DISPERBYK-2070, DISPERBYK-2096,
DISPERBYK-2013, DISPERBYK-2150,
DISPERBYK-2155, DISPERBYK-2163,
DISPERBYK-2164,
BYK-P104, BYK-P104S, BYK-P105,
BYK-9076, BYK-9077, BYK-220S, BYKJET-9150, BYKJET-9151 (manufactured by BYK-Chemie Japan),
Solsperse3000, Solsperse5000,
Solsperse9000, Solsperse11200,
Solsperse13240, Solsperse13650,
Solsperse13940, Solsperse16000,
Solsperse17000, Solsperse18000,
Solsperse20000, Solsperse21000,
Solsperse24000SC, Solsperse24000GR,
Solsperse26000, Solsperse27000,
Solsperse28000, Solsperse32000,
Solsperse32500, Solsperse32550,
Solsperse32600, Solsperse33000,
Solsperse34750, Solsperse35100,
Solsperse35200, Solsperse36000,
Solsperse36600, Solsperse37500,
Solsperse38500, Solsperse39000,
Solsperse41000, Solsperse54000,
Solsperse55000, Solsperse56000,
Solsperse71000, Solsperse76500,
Solsperse J180, Solsperse J200,
SolsperseX300 (manufactured by Lubrizol),
Disparon DA-7301, Disparon DA-325, Disparon DA-375, Disparon DA-234 (manufactured by Kusumoto Kasei Co., Ltd.),
Floren AF-1000, Floren DOPA-15B, Floren DOPA-15BHFS, Floren DOPA-17HF, Floren DOPA-22, Floren DOPA-33, Floren G-600, Floren G-700, Floren G-700AMP, Floren G-700DMEA, Floren G-820, Floren G-900, Floren GW-1500, Floren KDG-2400, Floren NC-500, Floren WK-13E, (manufactured by Kyoeisha Chemical Co., Ltd.),
TEGO Dispers610, TEGO Dispers610S,
TEGO Dispers630, TEGO Dispers650,
TEGO Dispers652, TEGO Dispers655,
TEGO Dispers662C, TEGO Dispers670,
TEGO Dispers685, TEGO Dispers700,
TEGO Dispers710, TEGO Dispers740W,
LIPOTIN A, LIPOTIN BL,
LIPOTIN DB, LIPOTIN SB (manufactured by Evonik Degussa),
PB821, PB822, PN411, PA111 (manufactured by Ajinomoto Fine Techno),
Texahole 963, Texahole 964, Texahole 987, Texahole P60, Texahole P61, Texahole P63, Texahole 3250, Texahole SF71, Texahole UV20, Texahole UV21 (manufactured by Cognis),
Examples include BorchiGenSN88 and BorchiGen0451 (both manufactured by Beaucious).

The ink for the decorative layer may further contain a surface conditioner from the viewpoint of improving wettability. As used herein, the term "surface conditioning agent" refers to a substance that has a hydrophilic site and a hydrophobic site in its molecular structure and can adjust the surface tension of the ink by adding it.

Specific examples of surface conditioning agents include dialkyl sulfosuccinates, alkylnaphthalene sulfonates, anionic surface conditioning agents such as fatty acid salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, Nonionic surface conditioning agents such as polyoxyethylene/polyoxypropylene block copolymers, cationic surface conditioning agents such as alkylamine salts and quaternary ammonium salts, acrylic surface conditioning agents, silicone surface conditioning agents, and fluorine-based surface conditioning agents. Examples include surface conditioning agents. Particularly preferred are silicone surface conditioners and acrylic surface conditioners, and commercially available products from Bikkemie, Evonik, Dow Corning Toray, etc. can be used. Furthermore, in the case of a silicone-based surface conditioner, it is preferable to use a polyether-modified silicone oil having an HLB of 7.6 to 12.

The amount of the surface conditioner can be appropriately selected depending on the purpose of use, but it is preferably 0.01 to 1% by mass in the ink, for example. The surface conditioning agents may be used alone or in combination of two or more.

Specific examples of surface conditioning agents include:
BYK-300, BYK-302, BYK-306, BYK-307, BYK-310, BYK-313, BYK-315N, BYK-320, BYK-322, BYK-323, BYK-325, BYK-326, BYK- 330, BYK-331, BYK-333, BYK-342, BYK-345, BYK-346, BYK-347, BYK-348, BYK-349, BYK-350, BYK-354, BYK-355, BYK-356, BYK-358N, BYK-361N, BYK-370, BYK-375, BYK-377, BYK-378, BYK-381, BYK-392, BYK-394, BYK-399, BYK-3440, BYK-3441, BYK- 3455, BYK-3550, BYK-3560, BYK-3565, BYK-3760, BYK-DYNWET 800N, BYK-SILCLEAN 3700, BYK-SILCLEAN 3701, BYK-SILCLEAN 3720, BYK-UV3500, B YK-UV3505, BYK-UV3510, BYK-UV3530, BYK-UV3535, BYK-UV3570, BYK-UV3575, BYK-UV3576 (manufactured by BYK Chemie Japan),
TEGO Flow 300, TEGO Flow 370, TEGO Flow 425, TEGO Flow ATF 2, TEGO Flow ZFS 460, TEGO Glide 100, TEGO Glide 110, TEGO Glide 130, TEGO Glide 406, TEGO Glide 410, TEGO Glide 411, TEGO Glide 415, TEGO Glide 432, TEGO Glide 435, TEGO Glide 440, TEGO Glide 450, TEGO Glide 482, TEGO GlideA 115, TEGO GlideB 1484, TEGO GlideZG 400 (manufactured by Evonik Japan),
501W ADDITIVE, FZ-2104, FZ-2110, FZ-2123, FZ-2164, FZ-2191, FZ-2203, FZ-2215, FZ-2222, FZ-5609, L-7001, L-7002, L-760 4 , OFX-0193, OFX-0309 FLUID, OFX-5211 FLUID, SF 8410 FLUID, SH3771, SH 3746 FLUID, SH 8400 FLUID, SH 8700 FLUID, Y-7006 (manufactured by Toray Dow Corning),
KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-640, KF-642, KF-643, KF-644, KF-945, KF-6004, KF- 6011, KF-6012, KF-6015, KF-6017, KF-6020, KF-6204, X-22-2516, and X-22-4515 (all manufactured by Shin-Etsu Chemical Co., Ltd.).

The decoration layer ink may contain an ultraviolet absorber. Ultraviolet absorbers have the effect of absorbing ultraviolet rays and preventing deterioration caused by ultraviolet rays. Examples of the ultraviolet absorber include cyanoacrylate compounds, benzophenone compounds, benzoate compounds, benzotriazole compounds, hydroxyphenyltriazine compounds, benzylidenecamphor compounds, and inorganic fine particles.

Specific examples of ultraviolet absorbers include:
2,4-dihydroxybenzophenone,
2-hydroxy-4-methoxybenzophenone,
2-hydroxy-4-methoxybenzophenone-5-sulfonic acid,
2-hydroxy-4-octoxybenzophenone,
2-hydroxy-4-dodecyloxybenzophenone-2-hydroxy-4-benzyloxybenzophenone,
bis(5-benzoyl-4-hydroxy-2-methoxyphenyl)methane,
2,2'-dihydroxy-4-methoxybenzophenone,
2,2'-dihydroxy-4,4'-dimethoxybenzophenone,
2,2',4,4'-tetrahydroxybenzophenone,
2-hydroxy-4-methoxy-2'-carboxybenzophenone,
2-(2'-hydroxy-5'-methylphenyl)benzotriazole 2-[2'-hydroxy-3',5'-bis(α,α-(dimethylbenzyl)phenyl]benzotriazole,
2-(2'-hydroxy-3',5'-di-t-butylphenyl)benzotriazole,
2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole,
2-(2'-hydroxy-3',5'-di-t-butylphenyl)-5-chlorobenzotriazole,
2-(2'-hydroxy-3',5'-di-t-amylphenyl)benzotriazole,
2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole,
2,2'-methylene-bis[4-(1,1,3,3-tetramethylbutyl)-6-(2N-benzotriazol-2-yl)phenol],
A condensate of methyl-3-[3-t-butyl-5-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]propionate and polyethylene glycol,
2-(2-hydroxyphenyl)benzotriazole,
2-(2'-hydroxy-5'-methylphenyl)benzotriazole,
2,6-di-t-butylphenyl-3',5'-di-t-butyl-4'-hydroxybenzoate,
Examples include hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate.

In the ink, the amount of ultraviolet absorber is preferably in the range of 0.1 to 15% by weight, more preferably 0.5 to 10% by weight, even more preferably 1 to 5% by weight. If the amount of ultraviolet absorber is too large, the film may not be sufficiently cured. The ultraviolet absorber may be used alone or in combination of two or more types, but it is preferable that the ultraviolet absorber contains at least two types of ultraviolet absorbers. By using multiple types of ultraviolet absorbers with different structures, the effects of the ultraviolet absorbers can be further sustained.

The decoration layer ink may contain a radical scavenger. A radical scavenger can capture free radicals and the like and improve photostability. Further, substances that react with free radicals and have a function of preventing polymerization reactions (so-called polymerization inhibitors) are also included in radical scavengers.

Examples of the radical scavenger include hindered amine compounds, hydroquinone compounds, phenol compounds, phenothiazine compounds, nitroso compounds, N-oxyl compounds, and particularly preferred are hindered amine light stabilizers (HALS).

Specific examples of radical scavengers include bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1-{2-(3-(3,5-di-t-butyl-4- hydroxyphenyl)propionyloxy)ethyl}-2,2,6,6-tetramethylpiperidine, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro{4. 5} Hindered amine compounds such as decane-2,4-dione, phenol, o-, m- or p-cresol, 2-t-butyl-4-methylphenol, 6-t-butyl-2,4-dimethylphenol , 2,6-di-t-butyl-4-methylphenol, 2-t-butylphenol, 4-t-butylphenol, 2,4-di-t-butylphenol, 2-methyl-4-t-butylphenol, 4- Phenolic compounds such as t-butyl-2,6-dimethylphenol, hydroquinone, hydroquinone monomethyl ether, methylhydroquinone, 2,5-di-t-butylhydroquinone, 2-methyl-p-hydroquinone, 2,3-dimethylhydroquinone , trimethylhydroquinone 4-methylbenzcatechin, t-butylhydroquinone, 3-methylbenzcatechin, 2-methyl-p-hydroquinone, 2,3-dimethylhydroquinone, trimethylhydroquinone, t-butylhydroquinone, benzoquinone, t-butyl-p - Hydroquinone compounds such as benzoquinone, 2,5-diphenyl-p-benzoquinone, phenothiazine compounds such as phenothiazine, nitroso compounds such as N-nitroso-N-phenylhydroxylamine ammonium, N-nitroso-N-phenylhydroxylamine aluminum salt, etc. system compounds, 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-oxo-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-methoxy-2 , 2,6,6-tetramethyl-piperidine-N-oxyl and other N-oxyl compounds.

In the ink, the amount of the radical scavenger is preferably 10% by mass or less, more preferably 7% by mass or less, and even more preferably 5% by mass or less. If the amount of radical scavenger is too large, it may cause poor curing. The lower limit of the content of the radical scavenger in the ink is, for example, 0.01% by mass or more, preferably 0.1% by mass or more, and more preferably 0.5% by mass or more. The radical scavengers may be used alone or in combination of two or more.

The decoration layer ink may contain resin. The resin has the role of forming a film on the substrate while capturing solid components such as pigments, and contributes to improving the adhesion of the ink to the substrate.

Specific examples of resins include polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, vinyl chloride resin, chlorinated rubber, chlorinated polyethylene resin, chlorinated polypropylene resin, chlorinated ethylene-vinyl acetate resin, acrylic resin, and polystyrene resin. , polyamide resin, polyurethane resin, polyolefin resin, silicone resin, fluororesin, epoxy resin, polyester resin, ketone resin, phenolic resin, polyvinyl alcohol, polyvinyl alcohol derivative (anion-modified polyvinyl alcohol, etc.), cellulose, cellulose derivative (hydroxymethyl cellulose, Hydroxyethyl cellulose, cellulose acetate, etc.), rosin resins, alkyd resins, alginic acid, alginic acid derivatives (alginic acid propylene glycol ester, etc.). Also included are modified products of these resins. For example, in the case of a resin having a hydroxyl group, modifications such as hydroxyalkyl etherification modification and carboxylic acid modification can be mentioned.

The amount of resin in the ink is preferably in the range of 25% by weight or less, particularly 20% by weight or less, more preferably 15% by weight or less. Too much resin may cause poor curing. The lower limit of the resin content in the ink is, for example, 0.1% by mass or more, preferably 0.3% by mass or more. One type of resin may be used alone, or two or more types may be used in combination.

Other ingredients of the decorative layer ink include antioxidants, plasticizers, rust preventives, solvents, antibacterial agents, antiviral agents, viscosity modifiers, fillers, antifoaming agents, charge control agents, and stress relaxation agents. , a penetrating agent, a light guiding material, a glittering material, a magnetic material, a fluorescent material, and other additives may be included as necessary.

The ink for the decorative layer can be prepared by mixing various components that are appropriately selected as necessary. Furthermore, in order to prevent head nozzles from clogging due to impurities, it is preferable to filter the ink using a filter.

The ink for the decorative layer preferably has a viscosity of 5 to 25 mPa·s, more preferably 5 to 20 mPa·s, at 20°C to 55°C. Since the temperature at which the ink is ejected is preferably 20° C. to 55° C., good ejection stability can be obtained if the ink viscosity is within the range specified above. Ink viscosity can be measured using a cone-plate viscometer.

The surface tension of the decorative layer ink at 25° C. is preferably 20 to 35 mN/m, more preferably 23 to 33 mN/m. If the ink surface tension at 25° C. is within the range specified above, good ejection stability can be obtained. Ink surface tension can be measured by the plate method.

For the cyan ink, magenta ink, and yellow ink used to form the decorative layer, regarding the hiding rate (%) of a dry film with a thickness of 10 μm formed from each ink, the hiding rate in the case of cyan ink is Ch, and the hiding rate for magenta is Ch. When the hiding rate of ink is Mh, and the hiding rate of yellow ink is Yh, Ch, Mh and Yh are preferably all 10% or more, more preferably 20% or more. When Ch, Mh and Yh are within the ranges specified above, color development can be improved. In addition, if the hiding rate is too high, the saturation will decrease and the color will become dull, and when ejecting ink from an inkjet printer to create a mixed color expression, the second ink droplet will be placed on top of the first ink droplet. When droplets overlap, it is undesirable from the viewpoint of color reproducibility of mixed colors if the first ink droplet is covered up by the second ink droplet to the extent that it affects the color development of the first ink droplet. . Therefore, Ch, Mh and Yh are all preferably within the range of 55±25% (30% to 80%), and preferably within the range of 55±20% (35% to 75%). More preferably, it is within the range of 55±15% (40% to 70%).

The cyan ink, magenta ink, and yellow ink used to form the decorative layer are expressed by the following relational expressions (1) to (3):
Formula (1) 0 ≦ |Ch−Mh| ≦ 25%
Formula (2) 0 ≦ |Mh-Yh| ≦ 25%
Formula (3) 0 ≦ |Yh-Ch| ≦ 25%
It is preferable to satisfy all of the relational expressions (4) to (6):
Formula (4) 0 ≦ |Ch−Mh| ≦ 23%
Formula (5) 0 ≦ |Mh-Yh| ≦ 23%
Formula (6) 0 ≦ |Yh-Ch| ≦ 23%
It is more preferable to satisfy all of the following. When Ch, Mh, and Yh satisfy the above relational expressions (1) to (3), particularly relational expressions (4) to (6), it is possible to improve the gradation property when mixing colors.

In this specification, the hiding rate of a dry film is measured according to method B (hiding rate test paper) of JIS K-5600-4-1:1999. A specific measurement example is shown below.
After printing a monochrome solid image on the white and black areas of the hiding rate test paper using an inkjet printer, each L ^* value is measured using a spectrophotometer, and it is derived by taking the ratio of the two values.
Example: When the L ^* value of the dry ink film on the white printed area is Lw, and the L ^* value of the ink dry film on the black printed area is Lb, the hiding rate of the dry film can be calculated using the following relational expression (7). can.
Formula (7) Hiding rate (%) = 100×Lb/Lw
Note that the dry ink film thickness when measuring the hiding rate is 10 μm.
In this specification, for example, an ink dry film is produced by the method shown below.
(Example) Using an inkjet printer [for example, an inkjet printer equipped with a KM1024-LHB head (42 pl droplets, manufactured by Konica Minolta)], print each CMY monochrome solid image (resolution 360 x 360 dpi) on a white background on a concealment rate test paper. Print on the black background. Thereafter, the ink is cured using a metal halide lamp to obtain a dried ink film. The thickness of the dried ink film is measured with a micrometer (for example, MDC-25MJ, manufactured by Mitutoyo Co., Ltd.).

As a means for adjusting the hiding rate of cyan ink, magenta ink, and yellow ink, it is preferable to use a white pigment. For this reason, it is preferable to use a white pigment in yellow ink and magenta ink in addition to cyan ink. Other examples include selection of pigment types and pigment particle diameters used in each color ink. The pigments contained in each color ink may be used alone or in combination of two or more.

Regarding the color mixture of cyan ink, magenta ink, and yellow ink used for forming the decorative layer, CIE (1976) 1:1 ratio of cyan ink, magenta ink, and yellow ink expressed in L ^* a ^* b ^* color space: The L ^* value of the dry film formed by mixing colors at a volume ratio of 1 is preferably within the range of 30 to 90, more preferably within the range of 35 to 85, and is within the range of 40 to 80. It is even more preferable. In addition, the L ^* value of a dry film formed by mixing cyan ink and magenta ink at a volume ratio of 1:1 expressed in the CIE (1976) L ^* a ^* b ^* color space is within the range of 30 to 80. It is preferably within the range of 30 to 75, more preferably within the range of 30 to 70. CIE (1976) L ^* a ^* b ^* The L ^* value of the dry film formed by mixing cyan ink and yellow ink at a volume ratio of 1:1 expressed in the color space must be within the range of 40 to 85. is preferably within the range of 40 to 80, more preferably within the range of 45 to 80. CIE (1976) L ^* a ^* b ^* The L ^* value of the dry film formed by mixing magenta ink and yellow ink in a 1:1 volume ratio expressed in color space must be within the range of 35 to 80. is preferably within the range of 35 to 75, more preferably within the range of 40 to 75. L ^* indicates the brightness (lightness) of the color, where L ^* =0 indicates black and L ^* =100 indicates white. The above L ^* value is obtained, for example, on a white background portion of a hiding rate test paper. If the L ^* value when the inks are mixed is within the range specified above, the brightness and darkness of each color will be balanced, and the color mixture from light to dark colors will be excellent in expression. Note that a ^* and b ^* indicate chromaticity indicating hue and saturation. a ^* represents the position of the color between red and green, with negative values indicating green and positive values indicating red. b ^* represents the position of the color between yellow and blue, with negative values indicating blue and positive values indicating yellow.

An example of a value other than the L ^* value is a color mixture of cyan ink, magenta ink, and yellow ink expressed in the CIE (1976) L ^* a ^* b ^* color space at a volume ratio of 1:1:1. The a ^* and b ^* values of the dried film are −1 to −23 and −48 to −18, respectively, and are 1 from cyan and magenta inks expressed in CIE (1976) L ^* a ^* b ^* color space. The a ^* and b ^* values of the dry film formed by color mixing at a volume ratio of :1 are 25 to 65 and -13 to 58, respectively, and are expressed in the CIE (1976) L ^* a ^* b ^* color space. The a ^* value and b ^* value of the dry film formed by mixing cyan ink and yellow ink at a volume ratio of 1:1 are −20 to 8 and 38 to 88, respectively, according to CIE (1976) L ^* a ^* b ^* The a ^* value and b ^* value of the dry film formed by mixing magenta ink and yellow ink at a volume ratio of 1:1 expressed in color space are -20 to 8 and 38 to 88, respectively. The above a ^* value and b ^* value are obtained, for example, on the white background portion of a hiding rate test paper.

A dry film formed by mixing cyan ink, magenta ink, and yellow ink in a volume ratio of 1:1:1, a dry film formed by mixing cyan ink, magenta ink, and yellow ink in a volume ratio of 1:1, cyan ink and As a means of adjusting L ^* a ^* b ^* of a dry film formed by mixing yellow ink at a volume ratio of 1:1, and a dry film formed by mixing colors of cyan ink and yellow ink at a volume ratio of 1:1. Examples include selection of pigment types. In particular, a dry film formed by mixing cyan ink, magenta ink, and yellow ink in a volume ratio of 1:1:1, a dry film formed by mixing cyan ink and magenta ink in a volume ratio of 1:1, and cyan. The L ^* value of the dry film formed by mixing ink and yellow ink in a 1:1 volume ratio, and the dry film formed by mixing cyan ink and yellow ink in a 1:1 volume ratio, within the range specified above. As a means for adjusting, it is preferable to use a white pigment. For this reason, it is preferable to use a white pigment in yellow ink and magenta ink in addition to cyan ink. Further, in addition to selecting the type of pigment used in each color ink, adjustment of the average dispersed particle diameter of the pigment, adjustment of the pigment concentration in the ink, etc. can be mentioned.

In this specification, the L ^* value is the correlation amount of lightness calculated by the formula (1) of 4.1 basic coordinates of JIS Z 8781-4:2013, and the a ^* value and the b ^* value are calculated according to the CIE ( 1976) In the L ^* a ^* b ^* color space, it is a color coordinate calculated by the formula (2) and formula (3) of 4.1 basic coordinates of JIS Z 8781-4:2013, and is commonly used in the technical field. It can be measured without particular limitation depending on the method (or device) used; for example, it can be measured using a spectrophotometer (for example, eXact, manufactured by X-Rite).

In this specification, color mixing refers to a method of printing monochrome solid images overlappingly. For example, a dry film formed by mixing cyan ink, magenta ink, and yellow ink at a volume ratio of 1:1:1 is a monochrome solid image printed from cyan ink at a volume ratio of 1:1:1. Refers to a dry film obtained by overlapping printing of a single-color solid image printed from magenta ink and a single-color solid image printed from yellow ink.

It is particularly preferable that printing using the ink for the decorative layer be performed by an inkjet printing method. Various inkjet printers can be used for inkjet printing. Examples of inkjet printers include inkjet printers that eject ink using a charge control method or a piezo method. Furthermore, large-sized inkjet printers, specifically inkjet printers intended for printing on articles produced on industrial lines, can also be suitably used.

When the ink for the decorative layer is an active energy ray-curable ink, the layer formed by printing is cured by irradiation with active energy rays such as ultraviolet rays. As a light source for active energy rays, a high-pressure mercury lamp, a metal halide lamp, an LED lamp, etc. can be used. Furthermore, the wavelength of the active energy rays irradiated to cure this layer preferably overlaps with the absorption wavelength of the photopolymerization initiator, and the main wavelength of the active energy rays is preferably 350 to 400 nm. The cumulative amount of active energy rays is preferably in the range of 100 to 2000 mJ/cm ² .

In printing, by appropriately selecting discharge conditions and subsequent curing conditions, it is possible to achieve a surface finish such as a glossy or matte finish. For example, if the ink spreads and then hardens after some time, it will become glossy, and if the ink droplets harden while remaining lens-shaped, it will become matte.

In the coated body of the present invention, the decorative layer has excellent color reproducibility and can express images with high sharpness. Here, examples of images with high sharpness include red brick-like patterns, blue marble-like patterns, portraits, and the like.

In the coated body of the present invention, the base material is, for example, epoxy resin, ABS resin, polycarbonate, polyvinyl chloride, polystyrene, acrylic resin, such as polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polyolefin, such as polypropylene ( Plastic base materials such as PP), metal base materials such as steel, galvanized steel, tin-plated steel, stainless steel, magnesium alloy, aluminum, aluminum alloy, titanium, titanium alloy, cement, mortar, concrete, slate, plaster, silicon Inorganic base materials other than metals such as calcium acid, glass, ceramics, calcium carbonate, marble, artificial marble, wood base materials such as wood, paper base materials, composite bases that combine two or more of these base materials Examples include wood. Composite base materials include, for example, composite base materials such as wood fiber reinforced cement boards, fiber reinforced cement boards, fiber reinforced cement/calcium silicate boards, metal base materials that have been subjected to various surface treatments, such as oxidation treatments, and Examples include plastic substrates whose surfaces are coated with an inorganic substance (for example, plastic substrates coated with glass).

There are various shapes of base materials, such as two-dimensional base materials such as film, sheet, and plate shapes, and three-dimensional base materials that are three-dimensional objects with complex shapes. The surface of the base material may be smooth or may have unevenness.

The surface of the base material may be subjected to pretreatment such as degreasing treatment, chemical conversion treatment, polishing, etc., or coating with a sealer or primer.

Specific examples of base materials include plastic materials such as PVC sheets, tarpaulin, plastic cardboard (plastic cardboard), and acrylic boards; coated paper (specifically, resin coated paper), art paper, cast paper, slightly coated paper, Paper such as high-quality paper, synthetic paper, and inkjet paper; Wooden building materials made from wood such as veneer, plywood, particle board, and medium density fiberboard (MDF); Ceramic siding boards, flexible boards, calcium silicate boards, Inorganic building materials such as gypsum slag barlite boards, wood chip cement boards, pulp cement boards, precast concrete boards, lightweight aerated concrete (ALC) boards, and gypsum boards; metal building materials such as aluminum, iron, and stainless steel, PCM steel boards, tiles, and glass boards etc.

The base material may be a building material such as an exterior material or an interior material. For example, examples of exterior building materials include building materials used for roofs, walls, etc., and examples of interior building materials include building materials used for floors, ceilings, walls, etc.

Preferably, the coated body of the present invention further includes an ink-receiving layer in addition to the base material and the decorative layer. By providing an ink-receiving layer, ink fixation can be improved. When the coated body of the present invention includes a base material, an ink-receiving layer, and a decorative layer, the surface on which the decorative layer is printed is the surface of the ink-receiving layer. That is, in this embodiment, the coated body includes a decoration layer formed on the ink receiving layer. Further, the ink-receiving layer may be formed directly on the base material, or there may be an additional layer between the base material and the ink-receiving layer (for example, a layer for improving the fixation of the ink-receiving layer to the base material). may exist.

In the coated body of the present invention, the ink receiving layer preferably contains a crosslinked resin. The crosslinked resin can prevent excessive penetration of ink into the ink-receiving layer and improve color development.

When the coated body of the present invention includes an ink-receiving layer, the surface of the ink-receiving layer is the surface on which the decorative layer is printed, so that the ink-receiving layer makes L ^* of the surface on which the decorative layer is printed. The value can be adjusted. Examples of means for adjusting the L ^* value of the ink-receiving layer include selection of the pigment type, adjustment of the average dispersed particle diameter of the pigment, adjustment of the pigment concentration, and use of a white pigment. In particular, the ink-receiving layer preferably contains a white pigment.

When the coated body of the present invention is an exterior building material, the ink-receiving layer is preferably formed from a water-based paint. Water-based paints are preferable from the viewpoint of environmental conservation because they do not contain volatile organic compounds or have a small content of volatile compounds.

The ink-receiving layer can be formed by applying an ink-receiving layer coating material to the surface of the base material, and then forming a film by drying or the like.

The paint for the ink-receiving layer preferably contains an aqueous dispersion of resin particles containing a resin, and in this resin, the proportion of structural units derived from a monomer having a cyclic structure is more than 0 and 28% by mass or less. Preferably used.

The resin used for the ink-receiving layer is not particularly limited, and includes, for example, a polymer containing a structural unit derived from a monomer without a cyclic structure, a structural unit derived from a monomer without a cyclic structure, and a structural unit derived from a monomer having a cyclic structure. and polymers containing. Each of the structural unit derived from a monomer without a cyclic structure and the structural unit derived from a monomer having a cyclic structure may be used alone, or two or more types may be used in combination.

Examples of monomers having a cyclic structure include alicyclic group-containing unsaturated hydrocarbons, aromatic ring-containing unsaturated hydrocarbons, alicyclic group-containing unsaturated carboxylic acids, alicyclic group-containing unsaturated carboxylic acid esters, and alicyclic group-containing unsaturated hydrocarbons. Unsaturated carboxylic acid amide containing a cyclic group, unsaturated carboxylic acid containing an aromatic ring, unsaturated carboxylic acid ester containing an aromatic ring, unsaturated carboxylic acid amide containing an aromatic ring, alkoxysilane containing an alicyclic group, alkoxysilane containing an aromatic ring, etc. can be mentioned. The alicyclic group and aromatic ring may have a heteroatom such as a nitrogen atom or an oxygen atom in the ring, or may have a substituent.

The alicyclic group is not particularly limited, and includes, for example, alicyclic hydrocarbon groups such as cycloalkyl groups (e.g., cyclohexyl group) and cycloalkenyl groups (e.g., cyclohexenyl group); alicyclic groups such as piperidyl group; Examples include heterocyclic groups. The aromatic ring is not particularly limited, and includes, for example, aromatic carbocycles such as benzene ring, naphthalene ring, and anthracene ring; and aromatic heterocycles such as pyridine ring.

Specific examples of the alicyclic group-containing unsaturated hydrocarbon include vinylcyclohexane. Specific examples of aromatic ring-containing unsaturated hydrocarbons include styrene and the like. Specific examples of the alicyclic group-containing unsaturated carboxylic acid include 3-cyclohexyl acrylic acid. Specific examples of the alicyclic group-containing unsaturated carboxylic acid ester include cyclohexyl (meth)acrylate, glycidyl methacrylate, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, and the like.

Specific examples of the alicyclic group-containing unsaturated carboxylic acid amide include N-cyclohexyl (meth)acrylamide and the like. Specific examples of the aromatic ring-containing unsaturated carboxylic acid include 3-phenyl (meth)acrylic acid. Specific examples of the aromatic ring-containing unsaturated carboxylic acid ester include phenyl (meth)acrylate. Specific examples of the aromatic ring-containing unsaturated carboxylic acid amide include N-phenyl (meth)acrylamide and the like. Specific examples of the alicyclic group-containing alkoxysilane include 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane.

Specific examples of the aromatic ring-containing alkoxysilane include 3-phenoxypropyltrimethoxysilane and 3-phenoxypropyltriethoxysilane. From the viewpoint of color development of the ink-receiving layer, cyclohexyl methacrylate, styrene, glycidyl methacrylate, 3-glycidoxypropyltriethoxysilane, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate and the like are preferred.

Monomers without a cyclic structure are not particularly limited, and include, for example, linear or branched unsaturated hydrocarbons, linear or branched unsaturated carboxylic acids, and linear or branched unsaturated carboxylic acids. Examples include acid esters, linear or branched unsaturated carboxylic acid amides, and the like. Specific examples of linear or branched unsaturated hydrocarbons include ethylene, propylene, and the like. Specific examples of linear or branched unsaturated carboxylic acids include (meth)acrylic acid.

Specific examples of linear or branched unsaturated carboxylic acid esters include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. ; Alkenyl (meth)acrylates such as allyl (meth)acrylate; 3-(meth)acryloyloxypropyltrialkoxysilanes such as 3-(meth)acryloyloxypropyltrimethoxysilane and 3-(meth)acryloyloxypropyltriethoxysilane; etc. Specific examples of linear or branched unsaturated carboxylic acid amides include diacetone (meth)acrylamide and the like.

As the monomer having no cyclic structure, methyl methacrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, butyl methacrylate, methacrylic acid, diacetone acrylamide, 3-methacryloyloxypropyltrimethoxysilane, and allyl methacrylate are preferred.

In the resin used for the ink-receiving layer, the ratio of structural units derived from monomers having a cyclic structure is preferably greater than 0 and 28% by mass or less, more preferably 0.01 to 26% by mass, and even more preferably 0.1 to 28% by mass. It is 25% by mass. The presence of a small amount of a monomer having a cyclic structure can be expected to be effective in adjusting the dot diameter.

The resin used in the ink-receiving layer is a polymer containing preferably 25 to 85% by mass of at least one structural unit derived from an ethylenically unsaturated monomer having a solubility parameter of 9.50 to 13.0. The solubility parameter is a guideline for determining compatibility, and there are various calculation methods and actual measurement methods, but in this specification, the solubility parameter of a monomer is calculated by the Hoy method based on the structure. Solubility Parameter

In this specification, the ethylenically unsaturated monomer refers to a monomer that has a double bond in its molecule and causes a polymerization reaction through addition to this double bond. The ethylenically unsaturated monomer is not particularly limited, and includes, for example, those having the above-mentioned double bond among those exemplified above as monomers having no cyclic structure and monomers having a cyclic structure.

The calculated glass transition temperature of the resin is preferably -15 to 85°C, more preferably -10 to 50°C, and even more preferably -5 to 40°C, from the viewpoint of reducing unreacted monomers. . When the calculated glass transition temperature is -15°C or higher, a sticky feeling is unlikely to remain after drying. When the calculated glass transition temperature is 85° C. or lower, drying is less likely to be delayed. As used herein, the term "calculated glass transition temperature" refers to the glass transition temperature calculated using the Fox equation.

A method for producing an aqueous dispersion of resin particles containing a resin includes, for example, using a conventional method to prepare a monomer without a cyclic structure, a monomer without a cyclic structure, and a monomer with a cyclic structure in an aqueous medium containing water as a main component. It can be produced by subjecting to emulsion polymerization, etc.

The resin content in the ink receiving layer is preferably 10 to 60% by weight, more preferably 20 to 45% by weight. When the resin content is 10 to 60% by mass, the monomer of the ink for the decorative layer is unlikely to remain in the ink-receiving layer after printing the decorative layer, and while maintaining excellent color development performance, Adhesion between the ink receiving layer and the decorative layer can be improved.

The paint for the ink-receiving layer may contain a pigment in addition to the water dispersion described above. The pigment is not particularly limited, and examples thereof include coloring pigments (eg, white pigments), antirust pigments, extender pigments, etc. that are commonly used in the paint industry.

Specific examples of coloring pigments, antirust pigments, and extender pigments include titanium oxide, red iron oxide, yellow iron oxide, carbon black, aluminum tripolyphosphate, zinc phosphate, condensed aluminum phosphate, barium metaborate, calcium carbonate, and sulfuric acid. Inorganic pigments such as barium, kaolin, talc, clay, mica, alumina, alum, clay, magnesium hydroxide, and magnesium oxide, as well as phthalocyanine blue, phthalocyanine green, naphthol red, quinacridone red, benzimidazolone yellow, Hansa yellow, and benzene. Examples include organic pigments such as imidazolone orange and dioxazine violet. The pigments may be used alone or in combination of two or more.

The pigment content in the ink receiving layer is preferably 35 to 85% by weight, more preferably 40 to 75% by weight. When the content of the pigment is 35 to 85% by mass, the monomer of the ink for the decorative layer is unlikely to remain in the ink-receiving layer after printing the decorative layer, and while maintaining excellent color development performance, Adhesion between the ink receiving layer and the decorative layer can be improved.

The coating material for the ink-receiving layer may further contain a film-forming aid. From the viewpoint of film-forming properties, the content of the film-forming aid is preferably 0 to 10% by mass based on the above-mentioned paint.

In addition to the above-mentioned components, the paint for the ink-receiving layer also contains additives commonly used in the paint industry, such as photopolymerization initiators, light stabilizers, polymerization inhibitors, organic solvents, antioxidants, and silane coupling agents. Agents, plasticizers, antifoaming agents, surface conditioning agents, wetting and dispersing agents, rheology control agents, ultraviolet absorbers, viscosity modifiers, preservatives, etc. may be appropriately selected and blended within a range that does not impede the purpose of the present invention. Good too.

The ink absorption rate of the ink receiving layer is preferably 100% or less, more preferably 90% or less, and even more preferably 85% or less. When the ink absorption rate is 100% or less, the amount of monomers in the active energy ray-curable ink remaining in the ink receiving layer in an uncured state can be reduced, and odor generation from the coated body can be effectively prevented. It can be suppressed.

In this specification, the ink absorption rate of the ink receiving layer can be measured as follows.
The paint for the ink-receiving layer is applied to a hard PVC board preheated to 60° C. using a 20 mil applicator, and dried at 100° C. for 3 minutes (downwind). The dry film is peeled off and cut into pieces of 50 mm in length x 50 mm in width, and the mass of the cut dry film is measured. Put 100 g of UV ink (black) into a 200 ml glass container, and then add the cut dry film. After immersion at 50°C for 24 hours, the membrane was taken out and placed on a Kim Towel (Crescia Co., Ltd.), and then a Kim Towel was placed on top of the Kim Towel to sandwich the membrane, and the membrane surface was exposed to UV light under a load of 500 g. Remove the ink and measure the mass of the dry film. The ink absorption rate is calculated using the following formula from the change in mass of the dry film before and after immersion.
Calculation formula:
{(mass after immersion - mass before immersion)/mass before immersion} x 100 = ink absorption rate (%)

The elongation rate of the ink receiving layer is preferably 10% or more. By setting the elongation rate of the ink-receiving layer to 10% or more, the toughness of the ink-receiving layer tends to be improved. The elongation rate of the ink-receiving layer can be adjusted by adjusting the intermolecular crosslinking density of the resin and the pigment content, which will be described later.

In this specification, the elongation rate of the ink-receiving layer can be measured as follows.
The ink-receiving layer paint is applied to a polypropylene plate using a 20 mil applicator and dried at 23° C. for 24 hours. Thereafter, it is dried at 80°C for 3 hours, and then at 120°C for 30 minutes. Then, the obtained dry film is peeled off and cut into a piece measuring 70 mm in length and 5 mm in width to obtain a test piece.
The test piece was subjected to a tensile test at 23°C and 50% RH using an Autograph AG-100KN I model manufactured by Shimadzu Corporation at a speed of 5 mm/min. Calculate the elongation rate. Here, the length of the test piece in the tensile test is set to 50 mm.
{(Length of test piece at break in tensile test - Length of test piece before test) / (Length of test piece before test)} x 100 = Elongation rate of test piece (ink receiving layer) (%)

In the resin particles in the paint for the ink-receiving layer, it is preferable that crosslinks exist between the resin molecules. When crosslinks exist between resin molecules, (1) the higher the crosslink density, the more suppressed the penetration of the active energy ray-curable ink into the ink-receiving layer. (2) The amount remaining in the ink-receiving layer can be easily reduced, and the generation of odor from the coated body can be effectively suppressed, and (2) the dissolution resistance of the ink-receiving layer to the above-mentioned monomers and solvents can be easily improved.

Crosslinking between resin molecules can be achieved by using crosslinking monomers such as 3-methacryloyloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, glycidyl methacrylate, allyl methacrylate, etc. as raw material monomers when producing the resin. It can be introduced by using in combination. For example, epoxy groups react with carboxyl groups such as acrylic acid and methacrylic acid. The crosslinking monomer used to introduce crosslinking between resin molecules can be used alone or in combination of two or more types.

Furthermore, examples of crosslinking monomers include diacetone acrylamide, N-(butoxymethyl)acrylamide, and the like.

Examples of crosslinking between particles include those introduced via a crosslinking agent such as a compound having an oxazoline group and adipic acid dihydrazide, and those introduced by self-crosslinking of resins between particles. When using a compound having an oxazoline group, the carboxyl group in the resin participates in the crosslinking reaction. When adipic acid dihydrazide is used, carbonyl groups in the resin participate in the crosslinking reaction.

When N-(butoxymethyl)acrylamide is contained in the raw material monomer, the butoxy group is removed by heating, and after the methylol group is generated, the resins present on different particles are self-crosslinked with each other. Each of the crosslinking monomers and crosslinking agents used to introduce crosslinks between particles can be used alone or in combination of two or more.

The ink-receiving layer can be formed by applying an ink-receiving layer coating material to the surface of the base material, and then forming a film by drying or the like. The coating method is not particularly limited, and includes, for example, air spray coating, airless spray coating, electrostatic coating, roll coater coating, flow coater coating, and the like.

The thickness of the ink receiving layer is, for example, 10 to 50 μm. The ink receiving layer may have one layer or multiple layers. Here, when the ink-receiving layer is composed of multiple layers, the thickness of the ink-receiving layer is the total thickness of the multiple ink-receiving layers.

Preferably, the coated body of the present invention further includes a clear layer. The clear layer is preferably formed on the decorative layer from the viewpoint of protecting the decorative layer. The clear layer means a layer whose visible light transmittance is 60% or more when the thickness is 10 μm. By using a layer with high visible light transmittance, the decorative layer can be protected without impairing the design of the decorative layer.

Visible light transmittance means total light transmittance in the visible region (360 nm to 750 nm), and can be measured in accordance with JIS K 7375:2008.

The coated body of the present invention may include a low staining property imparting layer on the outermost layer. Low staining property refers to the ability to make the surface of the painted body difficult to stain. Examples of the low-stain property imparting layer include a photocatalyst layer. The photocatalyst layer is a layer containing a material that exhibits photocatalytic action when irradiated with light such as sunlight. Examples of materials that exhibit photocatalytic action include metal oxides such as anatase titanium oxide, rutile titanium oxide, tin oxide, zinc oxide, and cerium oxide, but are not particularly limited to these materials.

The clear layer and the low-stain property imparting layer contain a resin, a dispersant, a surface conditioner, an antioxidant, a plasticizer, a rust preventive agent, a solvent, an antibacterial agent, an antiviral agent, a viscosity modifier, a filler, an antifoaming agent, Additives such as a charge control agent, a stress relaxation agent, a penetrating agent, a light guiding material, a glittering material, a magnetic material, a phosphor, an ultraviolet absorber, a radical scavenger, and the like can be included as necessary.

The clear layer and the low-stain property imparting layer are organic solvent-based paints and inks that use organic solvents as the main solvent, water-based paints and inks that use water as the main solvent, photocurable paints and inks that use photopolymerizable compounds, and powders. It can be formed from various paints such as paints and inks.

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

(Synthesis example 1)
In a five-neck flask equipped with a stirrer, a reflux condenser, a thermometer, a dropping device, and a nitrogen inlet tube, 386 parts by mass of ion-exchanged water and polyoxyethylene-1-(allyloxymethyl)alkyl ether sulfate ammonium salt (allyloxymethyl) were added. 10 parts by mass of Aquaron KH10 (manufactured by Ichi Kogyo Seiyaku Co., Ltd.) was charged, and the temperature was raised to 80° C. while purging the inside of the reactor with nitrogen. Thereafter, 4 parts by mass of ammonium persulfate was added to the reactor, and then 97 parts by mass of cyclohexyl methacrylate, 531 parts by mass of methyl methacrylate, 299 parts by mass of 2-ethylhexyl acrylate, and 39 parts by mass of methacrylic acid were mixed by stirring in a separate container. 579 parts by mass of ion-exchanged water were continuously added dropwise over 3.5 hours. Thereafter, the mixture was aged at 80° C. for 5 hours while stirring, and then cooled to room temperature. Thereafter, it was neutralized to pH 9 using a 28% by mass ammonia aqueous solution to obtain a resin particle aqueous dispersion 1 having a resin content of 50% by mass.

(Synthesis example 2)
Similar to Synthesis Example 1, synthesis was carried out using the monomer composition shown in Table 1 to obtain a resin particle aqueous dispersion 2 having a resin content of 50% by mass.

*1 Regarding the silane coupling agent KBM503, only the SP value of the organic group is shown.
・CHMA: Cyclohexyl methacrylate ・ST: styrene ・MMA; methyl methacrylate ・EHA: 2-ethylhexyl acrylate ・MAA: methacrylic acid ・KBM503: 3-methacryloyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.)

In Table 1, "derived from a cyclic structure-containing monomer in the resin" is the proportion (mass %) of structural units derived from a monomer having a cyclic structure in the resin. "Derived from a monomer with an SP value of 9.5 to 13.0" refers to the proportion (% by mass) of structural units derived from a monomer having a solubility parameter of 9.50 to 13.0 in the resin.

(Example of preparation of paint for ink-receiving layer)
The raw materials and titania beads were mixed according to the formulation shown in Table 2, and then dispersed in a bead mill. After dispersion, the titania beads were removed, and ink-receiving layer paints A to H were prepared.

1) Titanium oxide, density 3.8 g/cm ³ , (TITONER-62N, manufactured by Sakai Chemical Co., Ltd.)
2) Yellow iron oxide, density 4.1g/cm ³ , (TAROXLL-XLO, manufactured by Titan Kogyo Co., Ltd.)
3) Bengara, density 5.2g/cm ³ , (130ED, manufactured by Toda Pigment Co.)
4) Carbon black, density 2.0g/cm ³ , (Asahi #50, manufactured by Asahi Carbon Co., Ltd.)
5) Heavy calcium carbonate, density 2.7 g/cm ³ , average particle size 2 μm (manufactured by Maruo Calcium)
6) SN Deformer 1316 (manufactured by San Nopco)
7) ASE-60 (manufactured by Rohm and Haas)
8) Proxel A M (manufactured by Arch Chemicals)
9) TINUVIN1130 (manufactured by BASF)
10) Sanol LS-292 (manufactured by Sankyo Kasei Co., Ltd.)

(Example of ink preparation)
According to the formulation shown in Table 3, raw materials and zirconia beads (φ0.65 mm) were mixed and then dispersed in a bead mill. The amounts of each component in Table 3 are shown in parts by mass. After dispersion, the zirconia beads were removed and inkjet inks (cyan inks C1 to C9, yellow inks Y1 to Y3, and magenta inks M1 to M2) were prepared. Next, ink sets were prepared using the ink combinations shown in Tables 4 to 11.

The pigments used in producing the inks used in Examples and Comparative Examples are as shown below.
・DAIPYROXIDE Blue #9410 (C.I. Pigment Blue 28, manufactured by Dainichiseika Industries Co., Ltd.)
・BAYFERROX 130M (C.I. Pigment Red 101, manufactured by LANXESS)
・TAROX synthetic iron oxide HY-100 (C.I. Pigment Yellow 42, manufactured by Titan Kogyo Co., Ltd.)
・TITONE R-11P (C.I. Pigment White 6, manufactured by Sakai Chemical Industry Co., Ltd.)

The annotations in the table are as follows.
a) Surface conditioner TEGO-Glide 410 (manufactured by Evonic)
b) Pigment dispersant TEGO-Dispers 685 (manufactured by Evonic)

Below, a method for producing an ink-receiving layer, a method for producing a printed matter for evaluation, an evaluation method and criteria for the average dot diameter, L ^* value, color reproducibility of mixed colors, and sharpness and color development of the printed matter will be explained.

<Method for producing ink-receiving layers A to H>
A water-based sealer (manufactured by Dainippon Toyo Co., Ltd., product name: Water-based Mighty Sealer Multi) was applied to the surface of a slate board (150 mm x 70 mm x 5 mm, manufactured by TP Giken Co., Ltd.) using air spray at a coating amount of ¹⁰⁰ g/m2. A sealer-coated base material was prepared by drying at room temperature for 2 hours. With the sealer-coated base material heated to 60°C, the above-mentioned ink-receiving layer paints A to H were applied by air spray to the sealer-coated surface of the base material at a coating amount of 120 g/ ^m2 . . Thereafter, it was dried for 3 minutes in a drying oven set at 100° C. to produce base materials having ink receiving layers A to H.

<Method for producing printed matter for evaluation>
Using an inkjet printer equipped with an inkjet head (KM1024-LHB) manufactured by Konica Minolta, Inc., each combination of CMY and CMY was printed at a printing density ratio (volume ratio) of 50:50:50 at a resolution of 360 x 360 dpi. Adjust the monochrome solid image with a printing density ratio (volume ratio) of two colors of 100:100, and compare the white part of the hiding rate test paper (JIS standard product) with the base material or ink shown in Tables 4 to 11. The adjusted image was superimposed and printed on the receiving layer. After printing, the setting time shown in Tables 4 to 11 was set, and after the setting time had elapsed, the ink was cured using a metal halide lamp to obtain an ink dry film (decoration layer). In this way, printed matter was prepared for evaluating the L ^* value and the color reproducibility of mixed colors.
The printed matter for evaluating the average dot diameter was prepared by adjusting a solid image of each CMY color at a printing density of 3%, and printing the adjusted image on the base material or ink receiving layer shown in Tables 4 to 11. The setting times shown in 4 to 11 were set, and after the setting time had elapsed, the samples were manufactured by curing using a metal halide lamp.
In addition, in the evaluation of the L ^* value and the color reproducibility of mixed colors, the decoration layer on the white background part of the hiding rate test paper is compared with the decoration layer on the base material or ink receiving layer. The setting time after printing was adjusted on the white part of the hiding rate test paper so that the average dot diameter on the white part of the hiding rate test paper was equal to the average dot diameter on the base material or ink receiving layer. The average dot diameter was calculated by observing an image magnified 200 times with a microscope (Keyence Corporation).

The annotations added to the base materials in Tables 4 to 11 are as follows.
c) Polyvinyl chloride gray (manufactured by TP Giken)
d) Photo paper Glossy paper KJ-G13A4-10N (manufactured by KOKUYO)

<Average dot diameter>
The cyan ink, magenta ink, and yellow ink printed on the base material or ink-receiving layer were measured using a microscope (VHX-S550, manufactured by Keyence Corporation) for the printed matter produced according to the above <Method for producing printed matter for evaluation>. The average dot diameter was determined from a photographic image magnified 200 times. The results are shown in Tables 4-11. The unit of the average dot diameter shown in the table is μm.

<L ^* value>
The L ^* value of the surface on which the decorative layer is formed (i.e., the base material or the ink receiving layer formed on the base material) in the above <Method for producing printed matter for evaluation> was measured. Furthermore, the L ^* value of the decorative layer formed on the base material or the ink-receiving layer was measured using the printed matter produced in the above <Method for producing printed matter for evaluation>. A spectrophotometer (eg, eXact, manufactured by X-Rite) was used to measure the L ^* value. The results are shown in Tables 4-11.
In Tables 4 to 11, the L ^* value of the decorative layer shown in the item "C:M:Y" is based on the printing density ratio (volume ratio) of cyan ink: magenta ink: yellow ink of 50:50:50. This is the L ^* value of the printed decorative layer, and the L ^* value of the decorative layer shown in the "C:M" item is the printing density ratio (volume ratio) of cyan ink: magenta ink of 100:100. This is the L ^* value of the decorative layer printed in the "M:Y" item, and the L ^* value of the decorative layer is the printing density ratio (volume ratio) of magenta ink: yellow ink of 100:100. ), and the L ^* value of the decorative layer shown in the item "Y:C ^" is the printing density ratio (volume) of yellow ink: cyan ink of 100: This is the L ^* value of the decorative layer printed with the ratio (ratio).

<Evaluation method of color reproducibility of mixed colors>
The hue angle, a ^* value, and b ^* value of the decorative layer produced according to the above <Method for producing printed matter for evaluation> were measured. For each color combination, the tonality of the color mixture can be determined from the difference in hue angle (y described later) between the decorative layer prepared on the white background part of the hiding rate test paper and the decorative layer prepared on the base material or ink receiving layer. evaluated. Further, the color density of the mixed color was evaluated from the color difference between the a ^* value and b ^* (ΔC _ab described later). The results are shown in Tables 4-11. When the above y and ΔC _ab both showed a result of ◎ or ○ according to the evaluation criteria for each evaluation described below, the color reproducibility of mixed colors was considered to be excellent.

y can be calculated from formula (3) from the hue angle measured using a spectrophotometer (eXact, manufactured by X-Rite) for the decorative layer produced according to the above <Method for producing printed matter for evaluation>.
y = ∠H° _A - ∠H° _B ...Formula (3)
In formula (3), ∠H° _A indicates the hue angle of the decorative layer prepared on the white background part of the hiding rate test paper, and ∠H° _B indicates the hue of the decorative layer prepared on the base material or ink-receiving layer. Show the corner.
In Tables 4 to 11, "y" shown in the "C:M:Y" item indicates that cyan ink: magenta ink: yellow ink is printed at a printing density ratio (volume ratio) of 50:50:50. It is a value calculated from the hue angle of the decorative layer, and "y" shown in the "C:M" item is printed with cyan ink: magenta ink at a print density ratio (volume ratio) of 100:100. It is a value calculated from the hue angle of the decorative layer, and "y" shown in the "M:Y" item is printed with a print density ratio (volume ratio) of magenta ink: yellow ink of 100:100. It is a value calculated from the hue angle of the decorative layer, and "y" shown in the "Y:C" item is printed with a printing density ratio (volume ratio) of yellow ink: cyan ink of 100:100. This value is calculated from the hue angle of the decorative layer.

ΔC _ab is the a ^* value and b ^* value of the decorative layer produced according to the above <Method for producing printed matter for evaluation> using a spectrophotometer (eXact, manufactured by X-Rite). It can be calculated from equation (4) using
ΔC _ab = ((a ₁ - b ₁ ) ² - (a ₂ + b ₂ ) ² ) ^1/2 ...Equation (4)
In formula (4), _a1 indicates the a ^* value of the decorative layer prepared on the white background part of the hiding rate test paper, and _b1 indicates the b ^* value of the decorative layer fabricated on the white background part of the hiding rate test paper. , a ₂ indicates the a ^* value of the decorative layer produced on each base material, and b ₂ indicates the b ^* value of the decorative layer produced on each base material.
In Tables 4 to 11, "ΔC _ab " shown in the "C:M:Y" item is printed at a printing density ratio (volume ratio) of cyan ink: magenta ink: yellow ink of 50:50:50. "ΔC _ab " shown in the "C:M" item is a value calculated from the a ^* value and b ^* value of the decorative layer in which the cyan ink: magenta ink is printed at a printing density ratio of 100:100 ( It is a value calculated from the a ^* value and b ^* value of the decorative layer printed at the volume ratio), and "ΔC _ab " shown in the "M:Y" item is the magenta ink: yellow ink 100 It is a value calculated from the a ^* value and b ^* value of the decorative layer printed at a print density ratio (volume ratio) of :100, and "ΔC _ab " shown in the "Y:C" item is: This is a value calculated from the a ^* value and b ^* value of a decorative layer printed with yellow ink:cyan ink at a print density ratio (volume ratio) of 100:100.

<Evaluation of color reproducibility of mixed colors 1> Toneality of mixed colors For the decorative layer produced according to the above <Method for producing printed matter for evaluation>, y was calculated using the method described in <Method for evaluating color reproducibility of mixed colors> above. The tonality of color mixture was evaluated based on the following evaluation criteria. The results are shown in Tables 4-11.
(Evaluation criteria)
◎=y calculated for each mixed color printed matter all satisfies 0≦y≦10.
◯ = All y calculated for each mixed color printed matter satisfy y≦15, but at least a part of y satisfies 10<y≦15.
Δ=The y calculated for each mixed color printed matter all satisfy y≦25, but at least a part of y satisfies 15<y≦25.
×=y calculated for each mixed color printed matter partially or completely satisfies y>25.
If ◎, the color tone when mixing colors is not easily affected by the L ^* value of the base material or ink receiving layer, and a wide variety of colors can be expressed. If it is ○, the influence of the L ^* value of the base material or ink receiving layer is small, although it is not as bad as ◎, and the tonality of color mixture is excellent. If it is △, it can be seen that the tonality of the color mixture has decreased. If it is ×, it can be said that there is almost no tonality when mixing colors.

<Evaluation of color reproducibility of mixed colors 2> Color density of mixed colors Calculate ΔC _ab with the method described in <Method for evaluating color reproducibility of mixed colors> above for the decorative layer produced according to the above <Method for producing printed matter for evaluation> The color density of the mixed colors was evaluated based on the following evaluation criteria. The results are shown in Tables 4-11.
(Evaluation criteria)
◎=ΔC _ab calculated for each mixed color printed matter all satisfies 0≦ΔC _ab ≦10.
○=ΔC _ab calculated for each mixed color printed matter all satisfy ΔC _ab ≦20, but at least a part of ΔC _ab satisfies 10<ΔC _ab ≦20.
Δ=ΔC _ab calculated for each mixed _{color printed matter is ΔC ab ≦} 30, but at least a part of ΔC _ab satisfies 20<ΔC _ab ≦30.
×=ΔC _ab calculated for each mixed color printed matter partially or completely satisfies ΔC _ab >30.
If it is ◎, the color development is not easily affected by the L ^* value of the base material or the ink receiving layer, and the color reproducibility of mixed colors is excellent. If it is ○, although it is not as great as ◎, the influence of the L ^* value of the base material or ink-receiving layer is small, and mixed color reproduction with excellent visibility can be achieved. If it is Δ, the color becomes dull, and the color reproducibility as well as the color development of mixed colors are reduced. If it is ×, the color becomes dull and the color reproducibility of mixed colors is lost.

<Evaluation of sharpness and color development>
An inkjet printer equipped with an inkjet head (KM1024-LHB) manufactured by Konica Minolta, Inc. was used, and after each ink was filled into the inkjet printer, 5. Image identification number N3 described in Data Expression Method and Definition A fruit basket (basket) is printed on the base material or ink receiving layer shown in Tables 4 to 11, and the setting time shown in Tables 4 to 11 is set. After a period of time, it was cured using a metal halide lamp. The visibility and color development of the printed matter were visually evaluated, and the color density of the mixed color was evaluated based on the following evaluation criteria. The results are shown in Tables 4-11.
(Evaluation criteria)
◎= Both the detailed texture and color vividness of a fruit basket can be reproduced with excellent quality.
○=The border of the image of the fruit basket (basket) is clear and the color vividness is excellent.
△=There are parts where the border lines of the fruit basket image appear blurred, or where the colors are less vivid.
×=The color of the entire image is very dull, or the border line is unclear.
If ◎, the texture is expressed down to the details of the fruit basket (basket), and the colors are vivid, indicating that the painted body is suitable for expressing highly sharp images such as red brick-like patterns. . If it is ○, although it is not as good as ◎, an image with vivid colors can be obtained and the border lines are clear, so it is possible to express an image with high sharpness. If it is Δ, a printed image of a fruit basket in which the colors of each fruit are reproduced can be obtained, but there are some areas where the border lines are ambiguous and areas where the colors are less vivid. If it is ×, the color is too dull and the original color of the fruit or basket cannot be expressed, or the border line or image is unclear, making it unsuitable for printing.

<Overall evaluation of examples>
In Examples 2, 4, 6 to 8, 12, 14, 16, 18, 20, 23 and 24, the evaluation results of mixed color gradation, mixed color density, sharpness and color development were ○, and color reproduction was good. It is a coated body that has excellent properties and can produce highly sharp images. Examples 1, 3, 5, 9 to 11, 13, 15, 17, 19, 21 to 22, and 25 to 31 had evaluation results of ◎ for gradation of mixed colors, color density of mixed colors, sharpness, and color development. This coated body has particularly excellent color reproducibility and is suitable for expressing highly sharp images such as red brick-like patterns.

Claims (6)

A painted body comprising a base material and a decorative layer,
The surface on which the decorative layer is printed has an L ^* value of 40.0 to 98.0 in the CIE (1976) L ^* a ^* b ^* color space,
The decoration layer is formed from a plurality of inks including cyan ink, yellow ink, and magenta ink,
A painted body, wherein the cyan ink contains a white pigment. The painted body according to claim 1, wherein the yellow ink contains a white pigment. The coated body according to claim 1 or 2, wherein at least one ink among the plurality of inks is an active energy ray-curable ink containing a polymerizable compound containing alkylene oxide as a constituent unit. The coated body according to claim 1 or 2, wherein the decorative layer is formed from a plurality of dot-shaped inks, and the average dot diameter of the ink is within a range of 70 μm to 250 μm. The coated body according to claim 1 or 2, wherein the coated body further includes an ink-receiving layer, and the surface on which the decoration layer is printed is the surface of the ink-receiving layer. . The coated body according to claim 5, wherein the ink receiving layer contains a crosslinked resin.