Paint and paint set

Abstract

To provide a quick-drying paint that dries quickly while enabling three-dimensional drawing similar to an oil paint.SOLUTION: A paint cured by irradiation with ultraviolet light contains a pigment, and a medium material containing at least an ultraviolet curable resin and an extender pigment.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to paints and paint sets, and in particular to novel fast-drying paints that dry quickly when exposed to ultraviolet light. [Background technology]

[0002] Paints generally used for painting are divided into two types: paints and watercolors. Oil paints typically contain, as essential ingredients, pigments as coloring agents and binders (also called vehicles or mediums) that are primarily made of drying oil. In addition to the above essential ingredients, oil paints may contain additives such as forming aids and resins for adjustment purposes as needed.

[0003] Oil paints harden when they combine with oxygen in the air, causing the drying oil binder to polymerize. This hardening of oil paints through oxidation is called drying. Because oil paints have a long drying time of several days, they are easy to blend (mix), blur, and wipe off, making them suitable for creating paintings with bright, glossy wet colors. However, when painting with oil paints, subtle shades can be expressed by layering paints, so it is necessary to layer paints on top of fully hardened oil paints. Examples of conventionally used oil paints include those described in Patent Document 1. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 2862961 Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional oil paints such as those described in Patent Document 1 harden through an oxidative polymerization reaction, and therefore require a very long time for the paint to dry. As a result, a large proportion of the painting time is spent on drying, making it difficult to paint efficiently.

[0006] Furthermore, practicing brush techniques and mastering painting techniques takes a lot of time. Techniques for creating three-dimensional paintings by layering multiple layers require time for each layer to dry. Conventional oil paints, such as those described in Patent Document 1, require a significant amount of time to dry, resulting in significant time-consuming learning of painting techniques and wasting a lot of time in art education. Beginners who want to take up oil painting as a hobby can be discouraged by the long drying times. There are also concerns about accidentally knocking over a canvas while the paint is drying, or about the canvas collapsing in an earthquake or other disaster. This makes it difficult to complete time-pressured tasks such as final preparations for an exhibition or competition, or for practical exams.

[0007] To solve these problems, a method is known for shortening the drying time of oil paints by adding a forced drying agent (also known as a quick-drying medium or ciccative) to the oil paint. However, even oil paints prepared with the addition of a forced drying agent still require a drying time of several hours to several days, which is long. In addition, preparation requires time and effort, and the reagent costs are high.

[0008] The present invention has been made in view of the above background, and aims to provide a quick-drying paint that allows for three-dimensional drawing in the same way as oil paints, but dries quickly, and a paint set that includes said paint. [Means for solving the problem]

[0009] As a result of intensive research conducted by the present inventors to solve the above problems, they discovered that the above problems could be solved by using a paint containing an ultraviolet-curable resin and an extender pigment as a medium, and thus completed the present invention. That is, the present invention is as follows. (1) A paint that hardens when exposed to ultraviolet light, comprising a pigment and a medium containing at least an ultraviolet-curable resin and an extender pigment. (2) The paint according to (1), wherein the content of the ultraviolet-curable resin in the paint is 25% by mass or more. (3) The paint according to (1) or (2), wherein the mass ratio of the ultraviolet curable resin to the extender pigment is in the range of 20:80 to 80:20. (4) The paint according to any one of (1) to (3), wherein the extender pigment comprises aluminum hydroxide and calcium carbonate. (5) A paint according to any one of (1) to (4), wherein the pigment is an edible pigment that does not contain heavy metals, and the ultraviolet-curable resin is a resin that complies with the Food Sanitation Act. (6) A method for producing a pigment according to any one of (1) to (5), comprising a step of kneading the pigment with the medium containing the ultraviolet-curable resin and the extender pigment. (7) A paint set for preparing a mixed paint by mixing a paint with an ultraviolet-curable paint solution, the paint set comprising a paint according to any one of (1) to (5) and an ultraviolet-curable paint solution, the ultraviolet-curable paint solution comprising an ultraviolet-curable resin and an organic solvent. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a fast-drying paint that allows for three-dimensional drawing in the same way as oil paints, but dries quickly, and a paint set that includes said paint. DETAILED DESCRIPTION OF THE INVENTION

[0011] The paint and paint set of the present invention will be described in detail below, but the explanation of the constituent elements described below is an example (typical example) of one embodiment of the present invention, and the present invention is not limited to these contents.

[0012] In this specification, "paint" refers to materials used for painting and coloring paintings and for coloring crafts, etc., and includes pigments and binders. For this reason, "paint" has a completely different composition and use from "ink," which is a colored liquid used for writing or printing. Furthermore, "paint" has a completely different composition and use from "paint," which is a material that is applied to the surface of an object and hardens into a thin film to protect it and provide rust prevention, moisture prevention, corrosion prevention, chemical resistance, and oil resistance.

[0013] (paint) The paint of the present invention contains, as essential components, a pigment and a medium containing at least an ultraviolet-curable resin and an extender pigment.

[0014] The paint of the present invention contains an ultraviolet-curable resin as a medium, and can be instantly cured by irradiating it with ultraviolet light using an ultraviolet irradiator. This significantly reduces the drying time that was a problem with conventional oil paints.

[0015] Furthermore, the paints of the present invention, before exposure to ultraviolet light, are similar to the characteristics of conventional oil paints in that they are easy to blend (blend), blur, and wipe off. Furthermore, similar to the characteristics of conventional oil paints, they can be suitably used for creating paintings using techniques that involve layering multiple painting layers to create a three-dimensional effect, and for creating paintings with bright, glossy wet colors. In other words, the paints of the present invention are completely new paints that solve the problem of oil paints, namely their extremely long drying times, without compromising the excellent characteristics of conventional oil paints, such as their ability to impart a strong three-dimensional effect to brushstrokes or coatings.

[0016] It was previously thought that even if an ultraviolet-curing resin was added to an oil paint containing a pigment as a colorant, the pigment would block the ultraviolet light, and the oil paint, which creates a thickness and gives a three-dimensional effect, would not cure quickly. However, when the present inventors investigated the composition of paints containing ultraviolet-curing resins, they unexpectedly found that paints of a specified composition would cure quickly under ultraviolet light, and would dry quickly even when applied in layers to create a three-dimensional effect. Each component constituting the paint of the present invention will be explained below.

[0017] <Pigments> The pigment is not particularly limited, and inorganic and organic pigments commonly used as colorants for paints can be used. Both non-acid-treated and acid-treated pigments can be used as the pigment, and further, both dry powder and wet cake forms can be used.

[0018] The inorganic pigment is not particularly limited, and examples thereof include iron oxide and carbon black produced by a contact method, a furnace method, a thermal method, etc. The inorganic pigments may be used alone or in combination of two or more.

[0019] The organic pigment is not particularly limited, and examples thereof include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, and chelate azo pigments), polycyclic pigments (such as phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, and quinophthalone pigments), lake pigments (such as basic dye chelates and acid dye chelates), nitro pigments, nitroso pigments, and aniline black. The organic pigments may be used alone or in combination of two or more.

[0020] The average particle size (D50) of the pigment is not particularly limited, but is preferably 20 nm or more and 500 nm or less. If the average particle size is within the above range, the pigment dispersion stability is excellent and the paint tends to be able to be suitably cured by ultraviolet irradiation. The average particle size (D50) is measured, for example, by laser light diffraction / scattering method.

[0021] The pigment content in the paint is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 2% by mass or more. The content is preferably 10% by mass or less, more preferably 9% by mass or less, and even more preferably 8% by mass or less. If the pigment content is within the above range, the pigment can be prevented from inhibiting the curing of the UV-curable resin, and the paint tends to dry well when exposed to UV light.

[0022] <Medium> The medium functions as a binder and contains at least an ultraviolet curable resin and an extender pigment.

[0023] <<UV curable resin>> The ultraviolet curable resin is a monomer or oligomer that initiates polymerization and hardens when irradiated with ultraviolet light, and any conventionally known ultraviolet curable resin can be used.

[0024] UV-curable resins are generally broadly classified into cationic polymerization type epoxy resins and radical polymerization type acrylate resins. The UV-curable resin according to the present invention may be either a cationic polymerization type or a radical polymerization type.

[0025] More specifically, examples of the ultraviolet curable resin that can be used include ultraviolet curable urethane acrylate resin, ultraviolet curable polyester acrylate resin, ultraviolet curable epoxy acrylate resin, ultraviolet curable polyol acrylate resin, ultraviolet curable diallyl phthalate resin, and ultraviolet curable epoxy resin. The ultraviolet curable resin may be used alone or in combination of two or more.

[0026] It is particularly preferable to use an ultraviolet-curable resin that complies with the Food Sanitation Act as the ultraviolet-curable resin. For example, in the paint of the present invention, by combining, for example, an edible food pigment that does not contain heavy metals with an ultraviolet-curable resin that complies with the Food Sanitation Act, it is possible to provide a paint that is safe for the human body. Such a paint can be used from childhood, making it easy for children to learn painting techniques using paint from an early age. It may also be usable by people with allergies. Furthermore, the paint can be used safely by adults, for example, in environments where parents or children are present.

[0027] The above-mentioned UV-curable resins that comply with the Food Sanitation Act refer to synthetic resins that are defined as "synthetic resins" in Article 1 of the Enforcement Order of the Food Sanitation Act and that are cured by UV light, and are listed on the positive list that came into effect on June 1, 2020. UV-curable resins that comply with the Food Sanitation Act can be those that are already commercially available. An example of a UV-curable resin that complies with the Food Sanitation Act is the product name "Ekimate" (manufactured by NSS Co., Ltd.). Furthermore, examples of the above-mentioned edible pigments include titanium dioxide and other known edible natural pigments.

[0028] The content of the ultraviolet-curable resin in the paint is preferably 25% by mass or more, more preferably 35% by mass or more, and even more preferably 45% by mass or more. The content is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less. When the content of the ultraviolet-curable resin is within the above range, the inhibition of curing of the ultraviolet-curable resin by the pigment can be suppressed, and the paint tends to be cured favorably by ultraviolet irradiation.

[0029] <<Extender pigments>> The extender pigment is contained for the purposes of adjusting the concentration, improving physical properties such as viscosity, and improving storage stability. As the extender pigment, any of the conventionally known extender pigments contained in paints can be used. The extender pigment is preferably one that has a refractive index close to that of the ultraviolet curable resin and is transparent in the medium. Extender pigments with excellent lubricity are also preferred.

[0030] Specific examples of extender pigments include aluminum hydroxide, magnesium carbonate, calcium carbonate, barium sulfate, talc, clay, kaolin, silica, alumina silicate, and bentonite. The extender pigments may be used alone or in combination. Among these, aluminum hydroxide, calcium carbonate, and talc are preferred from the viewpoint of transparency and the like.

[0031] It is particularly preferable for the extender pigment to contain aluminum hydroxide and calcium carbonate. Aluminum hydroxide has a low refractive index and is therefore highly transparent. Calcium carbonate has a high refractive index and is therefore less transparent. To ensure that the ultraviolet light from an ultraviolet irradiator penetrates as deep into the paint as possible, highly transparent aluminum hydroxide is suitable as an extender pigment. However, using aluminum hydroxide alone as an extender pigment results in a paint that is very viscous and somewhat difficult to handle. Therefore, it is preferable to mix it with calcium carbonate, which is commonly used and has a smooth texture. This allows the ultraviolet light to penetrate deep into the paint, resulting in an extender pigment with good curing properties and appropriate viscosity.

[0032] When aluminum hydroxide and calcium carbonate are contained as the extender pigment, the mass ratio of aluminum hydroxide to calcium carbonate is preferably 30:70 to 70:30, more preferably 35:65 to 65:35, and even more preferably 40:60 to 60:40. When the mass ratio of aluminum hydroxide to calcium carbonate is within the above range, it tends to be possible to obtain an extender pigment having good curability and appropriate viscosity.

[0033] The content of the extender pigment in the paint is preferably 25% by mass or more, more preferably 35% by mass or more, and even more preferably 45% by mass or more. The content is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less. If the content of the extender pigment is within the above range, the paint is likely to become paste-like and to dry quickly when exposed to ultraviolet light.

[0034] The mass ratio of the ultraviolet curable resin to the extender pigment is preferably in the range of 20:80 to 80:20, more preferably in the range of 30:70 to 80:20, even more preferably in the range of 40:60 to 70:30, and particularly preferably in the range of 40:60 to 60:40. If the mass ratio of the ultraviolet curable resin to the extender pigment is within the above range, it is easy to obtain a paste-like paint that dries quickly when exposed to ultraviolet light.

[0035] <<Photopolymerization initiator>> The medium may contain a photopolymerization initiator. The polymerization initiator is not particularly limited as long as it is a compound that can generate radicals in the paint when irradiated with ultraviolet light and initiate polymerization of the ultraviolet-curable resin.

[0036] It is preferable to use a photopolymerization initiator that is suitable for the ultraviolet-curable resin to be used. Examples of radical photopolymerization initiators that can be used include alkylphenone-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, and titanocene-based photopolymerization initiators. Examples of cationic photopolymerization initiators that can be used include iodonium salt-based photopolymerization initiators and sulfonium salt-based photopolymerization initiators.

[0037] Examples of alkylphenone-based photopolymerization initiators include 1-hydroxycyclohexylphenylketone and 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one. Examples of thioxanthone-based polymerization initiators include diethylthioxanthone, 2-isopropylthioxanthone, and 2-chlorothioxanthone. Examples of acylphosphine oxide-based photopolymerization initiators include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0038] Examples of iodonium salt-based photopolymerization initiators include iodonium (4-methylphenyl) [4- (2-methylpropyl) phenyl] hexafluorophosphate, etc. Examples of sulfonium salt-based photopolymerization initiators include bis [4- (diphenylsulfonio) phenyl] sulfide bis hexafluorophosphate, etc.

[0039] When a photopolymerization initiator is contained, the content of the photopolymerization initiator is not particularly limited, but is usually about 0.5 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the ultraviolet curable resin.

[0040] (Other optional ingredients) The paint of the present invention may contain, as necessary, various known additives such as pH adjusters, preservatives or antifungal agents, surfactants, thickeners, waxes, etc. as other optional components. Examples of pH adjusters include inorganic salts such as ammonia, sodium carbonate, sodium phosphate, sodium hydroxide, and sodium acetate, and organic basic compounds such as water-soluble amine compounds such as triethanolamine and diethanolamine. Examples of the antiseptic or antifungal agent include carbolic acid, sodium salt of 1,2-benzisothiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl parahydroxybenzoate, and 2,3,5,6-tetrachloro-4-(methylsulfonyl)pyridine.

[0041] (Paint manufacturing method) The method for producing the paint of the present invention is not particularly limited, and it can be produced using any conventionally known method for producing paints. For example, the paint of the present invention can be produced by weighing out predetermined amounts of the pigment and the medium components including the ultraviolet-curable resin and the extender pigment, and thoroughly kneading them together. When additives are added, they can be further added to the composition obtained by the above method and kneaded together.

[0042] (How to use the paint) The paint of the present invention can be used by simply applying the paint to, for example, a canvas, and then irradiating it with ultraviolet light of a predetermined wavelength using an ultraviolet irradiator. Since the paint dries instantly, typically within 1 to 15 seconds after irradiation, it is possible to immediately apply additional paint without waiting for the paint to dry, as is the case with conventional paints. The ultraviolet irradiator must be able to irradiate ultraviolet light in the wavelength range of approximately 100 to 400 nm, and commercially available ultraviolet irradiators using a mercury-xenon lamp or LED light source can be suitably used.

[0043] The paints of the present invention described above have an extremely short drying time, significantly reducing the drying time of artworks. In particular, in techniques involving multiple layers, the drying time for each layer is significantly shorter, significantly reducing the drying time of the artwork. Furthermore, the extremely short drying time allows more time to be devoted to mastering painting techniques. In other words, the number of attempts to practice brush techniques and to explore and research various oil painting techniques can be increased. Furthermore, painting education can be conducted efficiently in art education settings. It also reduces the risk of artworks tipping over or being damaged during drying. Furthermore, it facilitates time-pressured tasks such as final preparations for exhibitions or public competitions, or practical exams.

[0044] Furthermore, the paint of the present invention is easy to operate, even for beginners, because it only requires irradiation with light using an ultraviolet irradiator. Furthermore, due to the recent trend toward mass production and price reduction of ultraviolet-curable resins, it can be manufactured with high performance and low cost. Furthermore, drying does not require a special, expensive, dedicated ultraviolet irradiator, and can be done using a commonly used ultraviolet irradiator.

[0045] (paint set) The paint of the present invention is a paste-like substance and is usually filled into a tube. When painting, the paint may be used as it is when squeezed out of the tube, or it may be diluted with painting solution before use. The paint set of the present invention is a paint set for preparing a prepared paint by mixing a paint with an ultraviolet-curable paint solution, and includes the paint of the present invention and an ultraviolet-curable paint solution.

[0046] <UV-curing paint solution> Art solutions are solutions that have functions such as increasing the adhesive strength of paints, improving spreadability, adjusting gloss, and improving transparency. The art solutions used in conventional paints contain drying oils such as linseed oil, poppy oil, and saffron oil, resins such as dammar resin and mastic resin, and volatile oils such as turpentine and petrol.On the other hand, the art solution for ultraviolet-curable paints (hereinafter sometimes abbreviated as UV paint solution) used in the paints of the present invention contains an ultraviolet-curable resin and an organic solvent.

[0047] That is, the UV paint solution included in the paint set of the present invention uses ultraviolet-curing resin instead of conventional drying oil, uses organic solvent instead of volatile oil, and does not contain resin. Like conventional art solutions, UV paint solutions have functions such as increasing the paint's adhesion, improving spreadability, adjusting gloss, and improving transparency.

[0048] <<UV curable resin>> The UV-curing resin contained in the UV paint solution is the same as that described for the paint.

[0049] The content of the UV-curable resin in the UV paint solution is not particularly limited, but is preferably 10% by mass or more and 90% by mass or less. If the content of the UV-curable resin is within the above range, a mixed paint with excellent adhesion and good spreadability tends to be obtained.

[0050] <<Organic solvents>> The organic solvent contained in the UV paint solution is not particularly limited and may be selected appropriately taking into consideration the solubility and drying properties of the UV-curable resin. The organic solvent is removed by evaporation after application.

[0051] Examples of organic solvents include alcohol-based organic solvents such as methanol, ethanol, 1-propanol, isopropanol, and butanol; ketone-based organic solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester-based organic solvents such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; aliphatic hydrocarbon solvents such as n-hexane, n-heptane, and n-octane; alicyclic hydrocarbon solvents such as cyclohexane, methylcyclohexane, ethylcyclohexane, cycloheptane, and cyclooctane; and aromatic hydrocarbon solvents such as toluene and (o-, m-, and p-)xylene. These organic solvents may be used alone or in combination. Among these, alcohol-based organic solvents are preferred as organic solvents for use in UV paint solutions, with ethanol, 1-propanol, and isopropanol being more preferred.

[0052] The content of organic solvent in the UV paint solution is not particularly limited, but is preferably 10% by mass or more and 90% by mass or less. If the content of organic solvent is within the above range, a mixed paint with excellent adhesion and good spreadability tends to be obtained. [Example]

[0053] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. In the examples, "parts", "%", and the like are based on mass unless otherwise specified.

[0054] [Raw materials] The raw materials used in the examples, reference examples and comparative examples are as follows. (UV curing resin) Urethane acrylate resin (product number: CH-S-1693 (DIC Corporation), viscosity 300 to 900 mPa·s) (extender pigment) Calcium carbonate (product name: Hakuenka DD (Shiraishi Kogyo Co., Ltd.)) Aluminum hydroxide (product name: G-15A fine aluminum hydroxide (Kusaba Chemical Co., Ltd.)) (pigment) <p1>White Titanium Oxide Color Index Name: PW6 (Sold by Kusakabe Co., Ltd.) <p2>Black Carbon Black Color Index Name: PBk7 (Sold by: Kusakabe) <p3>Naphthol Red (Color Index: PR170) (Sold by: Kusakabe) <p4>Blue Ultramarine Color Index Name: PB29 (Sold by: Kusakabe) <p5>Yellow Monoazo Yellow Color Index Name: PY3 (Sold by Kusakabe) (UV-curable ink) UV-curable ink (product name: UV ink Light Magenta, product number: SPC-0371Lm-6 (Mimaki Engineering Co., Ltd.)) (Commercially available paints) <op1>White paint (Product name: Practice Paint Set / Permanent White, Product number: 6S-12 (Kusakabe)) <op2>Black paint (Product name: Practice Paint Set / Ivory Black, Product Number: 6S-12 (Kusakabe)) <op3>Red paint (Product name: Practice Paint Set / Pure Red, Product number: 6S-12 (Kusakabe)) <op4>Blue paint (Product name: Practice Paint Set / Ultramarine, Product number: 6S-12 (Kusakabe)) <op5>Yellow paint (Product name: Practice Paint Set / Permanent Yellow Lemon, Product Number: 6S-12 (Kusakabe))

[0055] (extender pigment) The extender pigments were prepared as follows: Table 1 shows the blending ratios of each of the extender pigments A1 to A3. <Extender Pigment A1> 50 parts by mass of the calcium carbonate and 50 parts by mass of aluminum hydroxide were weighed and mixed to prepare extender pigment A1. <Extender pigments A2 and A3> Extender pigments A2 and A3 were prepared in the same manner as for extender pigment A1, except that the blending ratios were changed as shown in Table 1.

[0056] [Table 1]

[0057] (medium) <Preparation of medium> The media were prepared as follows: Table 2 shows the blending ratios of each of the media B1 to B9. <<Medium B1>> 50 parts by mass of the ultraviolet curable resin and 100 parts by mass of the extender pigment A1 were weighed and mixed to prepare a medium B1. <<Medium B2~Medium B9>> Medium B2 to Medium B9 were prepared in the same manner as Medium B1, except that the extender pigments and blending ratios were changed as shown in Table 2. <<Medium B10>> The above ultraviolet curable ink was used as a medium B10 in Reference Example 1.

[0058] <Evaluation of media> The suitability of the medium was evaluated as follows: (a) Evaluation of hardening properties The resulting medium was applied to a certain thickness on drawing paper and irradiated with ultraviolet light at wavelengths of 390 to 395 nm for 10 seconds using an ultraviolet irradiator. After irradiation, the curing of the medium was evaluated visually and by placing paper on the coated surface to check the degree of color transfer to the paper. The results are shown in Table 2. ◎: There is absolutely no color transfer to the paper, which is very good (no practical problems). Good: Almost no color transfer to the paper (no practical issues). △: There is some color transfer to the paper, but it does not interfere with practical use (almost no problem in practical use). ×: Color transfer to paper, hardly cured (problem in practical use).

[0059] (b) Viscosity evaluation The resulting medium was applied to drawing paper in a uniform thickness, and the viscosity was evaluated according to the following criteria to determine whether it was the optimum viscosity for use as a paint, and whether it had the optimum creamy or paste-like viscosity for paint. The results are shown in Table 2. ◎: Very good (no practical problems). Good (no practical problems). △: The viscosity is slightly high or low for use as a paint, but does not cause any problems in practical use (almost no problems in practical use). ×: Viscosity is too high or too low to be used as a paint (problems in practical use).

[0060] In Reference Example 1, the above ultraviolet-curable ink (product name: UV ink Light Magenta, product number: SPC-0371Lm-6 (manufactured by Mimaki Engineering Co., Ltd.)) was used instead of the medium, and the curability and viscosity were similarly evaluated. The results are shown in Table 2.

[0061] [Table 2]

[0062] As shown in Table 2, the media for the paint of the present invention met the curing properties and viscosity required for paint. Among these, medium B5 was particularly excellent in curing properties and viscosity. On the other hand, the ultraviolet-curable ink shown in Reference Example 1 had low viscosity and was completely unsuitable for use as a paint.

[0063] In this specification, ultraviolet-curable ink was used in Reference Example 1 for comparison with the present invention. However, since the main purpose of ink is printing or drawing, printability (suitability on a printing machine, workability) and color and gloss after printing are important. On the other hand, paint is used to create artwork, so workability such as curing and viscosity are important. For this reason, ink and paint have very different purposes and required suitability. For example, as shown in Reference Example 1, ultraviolet-curable ink cannot be used as paint.

[0064] (paint) <Preparing paint> The paints of Examples 1 to 15 were prepared as follows: Table 3 shows the blending ratios of Examples 1 to 15.

[0065] <<Example 1>> 99 parts by mass of the medium B5 and 1 part by mass of the pigment P1 were weighed out, and then thoroughly kneaded to prepare the paint of Example 1.

[0066] <<Example 2 ~ Medium 15>> Paints of Examples 2 to 15 were prepared in the same manner as Example 1, except that the pigments and blending ratios were changed as shown in Table 3.

[0067] <<Comparative Examples 1 to 5>> The above commercially available paints OP1 to OP5 were used as Comparative Examples 1 to 5.

[0068] <Evaluation of Paints> The suitability of each paint was evaluated as follows: (c) Evaluation of curing properties after UV irradiation The resulting paint was applied to a certain thickness of drawing paper as a medium, and then irradiated with ultraviolet light at wavelengths of 390 to 395 nm for 1, 5, or 15 seconds. After irradiation, the curing of the medium was evaluated visually and by placing paper on the coating surface to check the degree of color transfer to the paper. The results are shown in Table 3. ◎: There is absolutely no color transfer to the paper, which is very good (no practical problems). Good: Almost no color transfer to the paper (no practical issues). △: There is some color transfer to the paper, but it does not interfere with practical use (almost no problem in practical use). ×: Color transfer to paper, hardly cured (problem in practical use).

[0069] (d) Evaluation of hardening after leaving at room temperature The resulting paint was applied to a certain thickness of drawing paper with a medium, which was then left to stand at room temperature (approximately 25°C) and the time it took for the paint to harden was visually observed. Paints that had not hardened after one week were considered unhardened. The results are shown in Table 3.

[0070] [Table 3]

[0071] It can be seen that the paints of Examples 1 to 15 are fast-drying paints that dry quickly in 1 to 15 seconds after exposure to UV rays. In contrast, the paints of Comparative Examples 1 to 5, which do not contain UV-curable resin, do not harden when exposed to UV rays and require 4 to 6 days at room temperature to dry.

Claims

1. A pigment, a medium containing at least an ultraviolet curable resin and an extender pigment; A paint that hardens when exposed to ultraviolet light, including

2. 2. The paint according to claim 1, wherein the content of said ultraviolet-curable resin in the paint is 25% by mass or more.

3. 2. The paint according to claim 1, wherein the mass ratio of said ultraviolet curable resin to said extender pigment is in the range of 20:80 to 80:

20.

4. 2. The paint of claim 1, wherein said extender pigment comprises aluminum hydroxide and calcium carbonate.

5. The pigment is an edible pigment that does not contain heavy metals, 2. The paint according to claim 1, wherein the ultraviolet-curable resin is a resin that complies with the Food Sanitation Act.

6. A method for producing the paint according to any one of claims 1 to 5, A method for producing a paint, comprising the step of kneading the pigment with the medium containing an ultraviolet-curable resin and an extender pigment.

7. A paint set for preparing a prepared paint by mixing a paint and an ultraviolet-curing paint solution, The paint according to any one of claims 1 to 5, UV-curing paint solution and Including, The ultraviolet-curable paint solution contains an ultraviolet-curable resin and an organic solvent.

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