Antibacterial photocurable topcoat paint, laminate and method for manufacturing same, packaging container member and method for manufacturing same, and packaging container

Abstract

To provide an antibacterial photocurable finish coating material excellent in adhesiveness with a layer (an under coat film, an ink layer, and the like) disposed on an under layer, and adhesiveness after processing even if curing with a low exposure amount, and capable of forming a finish coated film having antibacterial property, a laminate and a production method of the same, a member for a packaging container and a production method of the same. and a packaging container.SOLUTION: The present invention is related to an antibacterial photocurable finish coating material including: a cationic polymerizable compound (A) having an epoxy group; a polyol (B) having two or three hydroxyl groups in one molecule and a number average molecular weight of 2,000 or less; a cationic photoinitiator (C); a three-functional radical polymerizable monomer (D); a radical photoinitiator (E); a polydimethylsiloxane-based leveling agent (F); and a silver-based compound (G) by a specific compounding amount.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an antibacterial photocurable topcoat paint. It also relates to a laminate having a topcoat film that is a cured product of the antibacterial photocurable topcoat paint and a method for producing the same. It also relates to a packaging container member having the laminate and a method for producing the same, and a packaging container having the packaging container member. [Background technology]

[0002] Photocurable compositions exhibit photocurability through polymerization and crosslinking when exposed to actinic rays such as ultraviolet rays, so they generally do not require a heating step and are therefore highly productive. For this reason, they are particularly useful for adherends that cannot be heated, and are widely used in a variety of applications.

[0003] For example, Patent Document 1 discloses a photocurable resin composition suitable for use in optical three-dimensional modeling. Specifically, the proposed photocurable resin composition contains a cationic polymerizable organic compound, a cationic photopolymerization initiator, an ethylenically unsaturated monomer, a radical photopolymerization initiator, and a polyether polyol having three or more hydroxyl groups per molecule, wherein 60% or more by mass of the ethylenically unsaturated monomer is a polyfunctional monomer having three or more ethylenically unsaturated bonds per molecule. Patent Document 2 also discloses an actinic radiation-curable composition suitable for use as a hard coat film, containing an acrylic compound, an alicyclic epoxy compound, and a curing catalyst. Patent Document 3 also discloses a photocurable composition for antibacterial coatings, which is composed of a photocurable acrylate-based polymerizable monomer containing a silver salt as an antibacterial agent.

[0004] Photocurable compositions are also used as topcoats for metal cans, such as art cans for storing sweets or tea leaves, aerosol cans for insecticides, and pull-top cans. The topcoat functions as a topcoat layer that protects designs, etc., made of an ink layer applied to the surface of the metal can. Such metal cans are available in three-piece and two-piece types. A three-piece can body is manufactured by sequentially forming a primer layer, an ink layer, and a top coat on a flat metal plate, cutting a rectangular piece for one can from the coated metal plate, rolling the rectangular piece into a cylindrical shape with the top coat facing outward, and joining the overlapping ends. The resulting cylindrical can body has open ends. A bottom member is attached to one open end of the cylindrical can body, and a lid member is attached to the other open end to allow contents to be placed inside and removed, completing the packaging container.

[0005] Two-piece can bodies are further divided into types in which a top coat or the like is formed before the metal plate is processed, and types in which a top coat or the like is formed after the metal plate is processed. The former two-piece type can body is manufactured by forming a primer layer, an ink layer, and a top coat layer on a flat metal plate, in that order, and then cutting a small piece for one can from the coated metal plate. This small piece is then molded so that the top coat layer and other layers are on the outer surface of the container, resulting in a cup-shaped member with an integrated peripheral wall (also called a side wall) and bottom (hereinafter sometimes referred to as a "first-coated, second-formed" two-piece type). The shape of the small piece can be selected depending on the shape of the container to be manufactured. The latter two-piece type can body is first produced by cutting a small piece for one can from a flat metal plate. The small piece is then molded into a cup shape with a peripheral wall (side surface) and a bottom surface integrated together. The peripheral wall (side surface) is then processed to increase its height as needed. The outer surface of the peripheral wall (side surface) is then coated with a primer layer, an ink layer, and a top coat in that order (hereinafter sometimes referred to as a "pre-formed, post-coated" two-piece type). The shape of the small piece can be selected depending on the shape of the container to be produced. The manufactured two-piece can body has one end open, and a lid member is attached to the open end to allow the contents to be placed inside and removed, forming a packaging container.

[0006] Alternatively, a packaging container may be formed by attaching a bottom member to one open end of a three-piece cylindrical can body and combining a relatively shallow two-piece member as a lid member with the other open end. Fig. 7 shows a schematic perspective view of such a packaging container. The main body 71 of packaging container 70 is composed of two parts, and the lid 75 is composed of one part. The main body 71 has a cylindrical can body 72 formed by forming a flat coated metal plate into a cylindrical shape and joining it at a seam 74, and a bottom member 73 attached to one open end of this can body 72. The lid 75 is made of a flat coated metal plate with the top and sides three-dimensionally processed into a single part, and is configured to be able to be opened and closed freely relative to the main body 71.

[0007] The can body of an art can is mainly a three-piece type. The can body of a pull-top can and the lid of an art can are mainly two-piece types that are "pre-coated and then formed." The can body of a beverage can and aluminum aerosol can is mainly two-piece types that are "pre-formed and then coated." [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 09-278811 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-102193 [Patent Document 3] Japanese Patent Application Publication No. 8-311373 Summary of the Invention [Problem to be solved by the invention]

[0009] Topcoats used on metal cans are required to have excellent adhesion to a wide variety of surfaces (primer coats, ink layers, etc.) because they are coated on a wide variety of materials. Furthermore, in the case of a three-piece can, when joining the can body to the bottom and lid components, the opening edge of the can body is gradually narrowed, and then the bottom and lid components are deformed by tightening them. In the case of a two-piece can, similar deformation is also applied to the opening edge of the lid when joining the peripheral wall and lid components. Alternatively, the can body (peripheral wall) may be deformed to form irregularities for decorative purposes and to improve strength. The relatively shallow lid components produced in the two-piece can system also undergo similar deformation at the opening edge. Therefore, there is a strong demand in the market for topcoats that can maintain adhesion even after these deformation processes. Furthermore, light-curable topcoats with extremely low solvent content have recently attracted attention from the perspective of reducing environmental impact, and there is a need for technology that can further reduce the amount of radiation exposure required for curing. In addition, there is a demand for paints that can form antibacterial coatings for applications such as beverage cans and powdered milk cans.

[0010] Although the above describes the problems associated with photocurable topcoat paints used on metal cans, similar problems can arise with photocurable topcoat paints in general.

[0011] The present invention has been made in view of the above background, and aims to provide a photocurable topcoat paint that can form a topcoat film that has excellent adhesion to the surface to be coated (undercoat film, ink layer, etc.) even when cured with a low amount of light exposure, that has excellent adhesion after processing, and that also has antibacterial properties; a laminate and a method for manufacturing the same; a component for a packaging container and a method for manufacturing the same; and a packaging container. [Means for solving the problem]

[0012] As a result of extensive research, the present inventors have found that the problems of the present invention can be solved by the following aspects, and have thus completed the present invention. [1]: A cationic polymerizable compound (A) having an epoxy group, a polyol (B) having two or three hydroxyl groups in one molecule and having a number average molecular weight of 2000 or less, and a cationic photopolymerization initiator (C), The composition contains a trifunctional radical polymerizable monomer (D), a radical photopolymerization initiator (E), a polydimethylsiloxane-based leveling agent (F), and a silver-based compound (G), the content of the radical polymerizable monomer (D) is 5 to 35 mass% relative to 100 mass% in total of the cationically polymerizable compound (A), the polyol (B), and the radical polymerizable monomer (D); the content of the cationic photopolymerization initiator (C) is 3 to 15 parts by mass relative to 100 parts by mass in total of the cationic polymerizable compound (A) and the polyol (B); the content of the radical photopolymerization initiator (E) is 1 to 10 parts by mass relative to 100 parts by mass of the radical polymerizable monomer (D); And the antibacterial activity value of the cured coating film according to JIS Z2801 is 2 or more. Antibacterial light-curing topcoat [2]: The antibacterial photocurable topcoat paint according to claim 1, wherein the cured coating film has an antiviral activity value of 2 or more according to JIS L1922. [3]: The antibacterial photocurable topcoat paint according to [1] or [2], having a surface tension of 29 mN / m or less. [4]: A laminate comprising a metal substrate, an undercoat film, an ink layer, and a topcoat film in this order, wherein the topcoat film is a cured product of the antibacterial photocurable topcoat paint described in any one of [1] to [3]. [5]: A laminate having a surface free energy of 25 mJ / m 2 The laminate according to [4] above. [6]: A packaging container member, comprising the laminate according to [4] or [5] in the form of a cylindrical body, the outer surface of the cylindrical body being coated with the topcoat coating film, and the cylindrical body having a seam. [7]: A packaging container member according to [6], wherein the joint on the outer surface of the cylindrical body is coated with a protective coating film. [8]: The packaging container member according to [6] or [7], further comprising a bottom member that closes the opening at the bottom of the cylindrical body. [9]: An integrally molded product formed from the laminate according to [4] or [5], the inner surface of which is concave due to the peripheral wall portion and the bottom surface portion, A packaging container member, wherein the outer surface of the integrally molded product is the topcoat coating film.

[10] : A packaging container comprising a container body having the packaging container member according to [8] or [9], and a lid member attached to the container body to cover the opening of the container body.

[11] : Forming a primer coating on a metal substrate; forming an ink layer on the undercoat film; A method for producing a laminate, comprising applying the antibacterial photocurable topcoat paint according to any one of [1] to [3] onto the ink layer and curing it to form a topcoat film.

[12] : The curing process of the antibacterial light-curable topcoat paint is carried out with an integrated light intensity of 200 mJ / cm 2 of light in the wavelength range of 320 nm or more and 390 nm or less. 2

[11] The method for producing a laminate according to

[11] , wherein the method is carried out by irradiating the laminate so as to:

[13] : Forming a primer coating on a metal substrate; forming an ink layer on the undercoat film;

[0033] Applying the antibacterial photocurable topcoat paint according to any one of [1] to [3] onto the ink layer and curing it to form a topcoat coating film to obtain a laminate; Using the laminate, a cylindrical body is formed, the outer surface of which is the topcoat coating film, and the peripheral wall portion includes a seam; A method for manufacturing a packaging container member, comprising a step of covering the joint on the outer surface of the cylindrical body with a protective coating film.

[14] : Forming a primer coating on a metal substrate; forming an ink layer on the undercoat film;

[0033] Applying the antibacterial photocurable topcoat paint according to any one of [1] to [3] onto the ink layer and curing it to form a topcoat coating film to obtain a laminate; A method for manufacturing a packaging container member, comprising a step of using the laminate to form an integrally molded product whose inner surface is concave due to the peripheral wall portion and the bottom surface portion, and whose outer surface is the topcoat coating film.

[15] : The curing process of the antibacterial light-curable topcoat paint is carried out with an integrated light intensity of 200 mJ / cm 2 of light in the wavelength range of 320 nm or more and 390 nm or less. 2 The method for producing a packaging container member according to

[13] or

[14] , wherein the method is carried out by irradiating the member so as to: [Effects of the Invention]

[0013] The present invention has the excellent effect of providing an antibacterial photocurable topcoat coating that can form a topcoat film that has excellent adhesion to the surface to be coated (undercoat film, ink layer, etc.) and also has excellent adhesion after processing, and that has high antibacterial properties, even when cured with a low exposure dose; a laminate and a method for producing the same; a packaging container member and a method for producing the same; and a packaging container. 2 The present invention provides an antibacterial photocurable topcoat paint that can form a topcoat film that has excellent adhesion to the surface to be coated (undercoat film, ink layer, etc.) and also has excellent adhesion after processing, by irradiating it with light in the UVA wavelength range (320-390 nm) described below; a laminate and a method for manufacturing the same; a packaging container component and a method for manufacturing the same; and a packaging container. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 2 is a schematic top view showing an example of a laminate according to the present embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1. [Figure 3] 3 is a cross-sectional view taken along line III-III in FIG. 1 (a modified example of FIG. 2). [Figure 4] FIG. 2 is a schematic perspective view showing an example of a packaging container member according to the present embodiment. [Figure 5] FIG. 5 is a partially enlarged explanatory view of region V in FIG. 4. [Figure 6] 3A to 3C are schematic explanatory views of essential parts illustrating an example of a method for joining members for packaging containers according to the present embodiment. [Figure 7] FIG. 1 is a schematic perspective view showing an example of a metal can in which a container body made of two parts and a lid member made of one part are combined. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention will be described in detail below. Needless to say, other embodiments are also included within the scope of the present invention as long as they are consistent with the spirit of the present invention. Furthermore, in this specification, a numerical range specified using "to" includes the numerical values ​​written before and after "to". Furthermore, in this specification, "film" and "sheet" are not distinguished by thickness. Furthermore, unless otherwise noted, the various components appearing in this specification may be used independently, either singly or in combination of two or more types. Furthermore, the same reference numerals are used to designate identical or equivalent components.

[0016] [[Antibacterial light-curing topcoat]] The antibacterial photocurable topcoat paint (hereinafter referred to as "the paint") according to this embodiment contains a cationically polymerizable compound (A) having an epoxy group (hereinafter referred to as "cationically polymerizable compound (A)"), a polyol (B) having two or three hydroxyl groups per molecule and a number-average molecular weight of 2000 or less (hereinafter referred to as "polyol (B)"), a cationic photopolymerization initiator (C), a trifunctional radically polymerizable monomer (D) (hereinafter referred to as "radically polymerizable monomer (D)"), a radical photopolymerization initiator (E), a polydimethylsiloxane-based leveling agent (F) (hereinafter referred to as "leveling agent (F)"), and a silver-based compound (G). The content of the radically polymerizable monomer (D) is 5 to 35% by mass relative to 100% by mass of the total of the cationically polymerizable compound (A), polyol (B), and radically polymerizable monomer (D). The content of the cationic photopolymerization initiator (C) is 3 to 15 parts by mass per 100 parts by mass of the total of the cationic polymerizable compound (A) and polyol (B), and the content of the radical photopolymerization initiator (E) is 1 to 10 parts by mass per 100 parts by mass of the radical polymerizable monomer (D). The antibacterial activity value according to JIS Z2801 of the cured coating film formed from this coating material is 2 or more.

[0017] By applying this paint to a surface to be coated and irradiating it with actinic rays, a cured topcoat film is formed on the surface. The topcoat film is a topcoat layer that functions as a finishing varnish. The topcoat film can protect the surface to be coated. Furthermore, if the surface to be coated is printed, the topcoat film can adequately protect the printed surface during processing and transportation of the surface, and can also improve the adhesion of the printed layer.

[0018] This coating material can be obtained by uniformly mixing the components. The term "cured product" refers to the coating material cured by irradiating it with actinic rays. Examples of actinic rays include ultraviolet rays, visible light, infrared rays, X-rays, alpha rays, beta rays, and gamma rays. Among these, ultraviolet rays and visible light are preferred in terms of ease of handling, with ultraviolet rays being more preferred, and the UVA wavelength range being particularly suitable. In this specification, the UVA wavelength range refers to wavelengths of 320-390 nm.

[0019] The uses of the present coating material are not particularly limited, and the material of the surface to be coated is not particularly limited. The present coating material can be widely used, for example, as a coating material for a topcoat film to cover a surface to be coated that has formed on it an intermediate layer such as a primer film and / or a printed ink layer. It can also be used for applications in which the coating material is applied directly onto the substrate.

[0020] This paint is particularly suitable as a topcoat for printed metal cans. Metal cans can be manufactured by processing a laminate consisting of a primer coat, an intermediate ink layer, and a topcoat coat, i.e., the three-piece method mentioned above, the two-piece pre-coated and post-formed method, or the pre-formed and post-coated method.

[0021] Generally, when a cationic polymerizable component is used as the photopolymerizable component of a paint, the curing speed required to obtain a coating film is slower than when a radically polymerizable component is used. One way to increase the curing speed is to increase the amount of cationic photopolymerization initiator (C). However, if the amount of initiator is too high, while the surface layer cures quickly, the deeper the layer, the more light is absorbed by the cationic photopolymerization initiator (C) contained in the coating film in the relatively upper layers, making it difficult for sufficient light to reach the deeper layers, thereby hindering uniform curing. Furthermore, when a cationic polymerizable component is used, a curing rate of 250 mJ / cm is usually required. 2 (UVA wavelength range) or more, and in some cases, 1J / cm 2 On the other hand, radically polymerizable components generally have a fast curing speed, but they tend to become hard and brittle due to their large curing shrinkage, and their adhesion tends to decrease compared to cationically polymerizable compounds (A).

[0022] This coating composition, which combines a cationically polymerizable component and a radically polymerizable component and a leveling agent (F), provides a photocurable topcoat coating that exhibits excellent curability even when cured at low exposure doses, and can form a topcoat film that exhibits excellent adhesion to the surface to be coated (undercoat film, ink layer, etc.) and also exhibits excellent adhesion after processing. By combining a cationically polymerizable compound (A) having an epoxy group and a polyol (B) as the cationic component with a specific amount of a trifunctional radically polymerizable monomer (D) as the radical component, curing at low exposure doses is possible, and the curing speed and cure shrinkage can be appropriately controlled. In particular, this coating composition exhibits excellent curability even when cured at low exposure doses, even at an integrated light dose of 200 mJ / cm. 2 It is suitable for applications that irradiate light in the UVA wavelength range below.

[0023] Furthermore, by combining the leveling agent (F) with the above-mentioned components, it is possible to significantly improve adhesion to the surface to be coated (undercoat film, ink layer, etc.). Furthermore, by combining the above-mentioned components with the specific amounts of the cationic photopolymerization initiator (C) and the radical photopolymerization initiator (E), it is possible to provide a photocurable topcoat paint that can suppress curing inhibition while also improving adhesion after processing. Although the present paint is suitable for use in low light exposure, this does not mean that the paint can be exposed to high light exposure. Each component of the present paint will be described in detail below.

[0024] [Cationically polymerizable compound (A)] The cationically polymerizable compound (A) is a compound having at least one epoxy group, and is preferably a polyfunctional epoxy compound having two or more epoxy groups. It refers to a compound that polymerizes or crosslinks by cations. It is preferable to use 60 to 100 mass% of the cationically polymerizable compound (A) having two or more epoxy groups in 100 mass% of the cationically polymerizable compound (A). From the viewpoint of effectively suppressing cure shrinkage, it is more preferable to use 60 to 100 mass% of the cationically polymerizable compound (A) having two epoxy groups in 100 mass% of the cationically polymerizable compound (A).

[0025] Specific examples of the cationically polymerizable compound (A) include a cationically polymerizable compound (a1) having an alicyclic epoxy group (hereinafter also referred to as "compound (a1)" or alicyclic epoxy compound (a1)), a cationically polymerizable compound (a2) having a glycidyl ether group (hereinafter also referred to as "compound (a2)" or compound (a2) having a glycidyl ether group), and the like.

[0026] As the cationically polymerizable compound (A), an alicyclic epoxy compound (a1) is preferred from the viewpoint of reducing cure shrinkage and optimizing the cure speed. Furthermore, from the viewpoint of improving processing adhesion, it is preferable to use a compound (a2) having a glycidyl ether group in combination. By combining a highly reactive compound (a1) with a compound (a2) whose reactivity is lower than that of (a1), the balance between cure speed, cure shrinkage, and processing adhesion can be easily adjusted. Furthermore, while excellent film-forming properties can be obtained by using compound (a1), the viscosity can be adjusted with compound (a2) to improve coatability. A more preferred combination of compound (a1) and compound (a2) is a combination of a cationically polymerizable compound having a bifunctional alicyclic epoxy group and a cationically polymerizable compound having a bifunctional glycidyl ether group.

[0027] The total content of compound (a1) and compound (a2) in 100% by mass of the cationically polymerizable compound (A) is preferably 60 to 100% by mass. From the viewpoints of curing speed and reduced cure shrinkage, it is preferable that the mass ratio of compound (a1) to compound (a2) is in the range of 100:0 to 60:40. Furthermore, from the viewpoint of processing adhesion, it is more preferable that the mass ratio of compound (a1) to compound (a2) is in the range of 90:10 to 65:35. The alicyclic epoxy group refers to a group that forms an epoxy bond on the ring of a cycloalkane having 4 to 12 carbon atoms. The cationically polymerizable compound (A) can be used alone or in combination of two or more.

[0028] Examples of the alicyclic epoxy compound (a1) include 4-vinylcyclohexene monoepoxide, norbornene monoepoxide, limonene monoepoxide, limonene dioxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, bis-(3,4-epoxycyclohexylmethyl)adipate, 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexanone-meta-dioxane, and 3,4-epoxycyclohexylmethyl methacrylate. Examples of commercially available products include Celloxide 2021P, Celloxide 2081, Celloxide 2000, Cyclomer M100, and Epolead GT-401 (all manufactured by Daicel Corporation).

[0029] Examples of the compound (a2) having a glycidyl ether group include 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane diglycidyl ether, trimethylolpropane triglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, brominated bisphenol A diglycidyl ether, epoxy novolac resin, hydrogenated bisphenol A diglycidyl ether, and 1,4-bis[(oxiran-2-ylmethoxy)methyl]cyclohexane. Examples of commercially available products include Rikaresin HBE-100, Rikaresin DME-100, Rikaresin L-200, Rikaresin BPO-20E, and Rikaresin BEO-60E (all manufactured by New Japan Chemical Co., Ltd.), Denacol EX-121, Denacol EX-141, Denacol EX-145, Denacol EX-212, Denacol EX-211, Denacol EX-201, Denacol EX-252, Denacol EX-850, Denacol EX-851, Denacol EX-612, Denacol EX-313, Denacol EX-314, Denacol EX-421, Denacol EX-321, Denacol EX-321L, and Denacol EX-411 (all manufactured by Nagase ChemteX Corporation).

[0030] From the viewpoint of ensuring and improving adhesion and processability, the content of the cationic polymerizable compound (A) is preferably 50 to 85 mass%, more preferably 55 to 75 mass%, relative to 100 mass% of the cationic polymerizable compound (A), polyol (B), cationic photopolymerization initiator (C), trifunctional radical polymerizable monomer (D), and radical photopolymerization initiator (E).

[0031] [Polyol (B)] The polyol (B) is a compound having two or three hydroxyl groups per molecule and a number average molecular weight (hereinafter, number average molecular weight will be abbreviated as Mn) of 2000 or less. It can be appropriately selected from conventionally known polyols. By using a polyol (B) having two or three hydroxyl groups per molecule, it is possible to improve adhesion during processing.

[0032] As the polyol (B), various polyether polyols, polyester polyols, polycarbonate polyols, polybutadiene glycols, etc. can be used. Examples of polyether polyols include polymers or copolymers of ethylene oxide, propylene oxide, tetrahydrofuran, and the like.

[0033] Examples of polyester polyols include saturated or unsaturated low-molecular-weight diols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-pentanediol, hexanediol, octanediol, 1,4-butylenediol, diethylene glycol, triethylene glycol, dipropylene glycol, and dimer diol, and adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, and glycol. Examples of suitable polyester polyols include polyester polyols obtained by reacting dicarboxylic acids such as taric acid, pimelic acid, suberic acid, azelaic acid, or sebacic acid, or anhydrides thereof; polyester polyols obtained by reacting alkyl glycidyl ethers such as n-butyl glycidyl ether or 2-ethylhexyl glycidyl ether; or monocarboxylic acid glycidyl esters such as versatic acid glycidyl ester with anhydrides of the above dicarboxylic acids in the presence of a hydroxyl group-containing compound such as an alcohol; and polyester polyols obtained by ring-opening polymerization of a cyclic ester compound.

[0034] Examples of polycarbonate polyols include: 1) Reaction products of glycols or bisphenols with carbonate esters, or 2) Reaction products obtained by reacting glycol or bisphenol with phosgene in the presence of an alkali can be used. Examples of glycols that can be used in the above cases 1) and 2) include ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, butylene glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 3,3'-dimethylolheptane, polyoxyethylene glycol, polyoxypropylene glycol, propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, neopentyl glycol, octanediol, butylethylpentanediol, 2-ethyl-1,3-hexanediol, cyclohexanediol, 3,9-bis(1,1-dimethyl-2-hydroxyethyl), 2,2,8,10-tetraoxospiro[5.5]undecane.

[0035] Among these, polyether polyols are preferred as the polyol (B) from the viewpoint of handling.

[0036] Examples of polyether polyols include reaction products obtained by addition polymerization of one or more oxirane compounds using a compound having two or three hydroxyl groups per molecule as an initiator. Examples of compounds having two or three hydroxyl groups per molecule include ethylene glycol (EG), propylene glycol (PG), 1,4-butanediol, neopentyl glycol, butylethylpentanediol, glycerin, and trimethylolpropane. Examples of oxirane compounds include alkylene oxides such as ethylene oxide (EO), propylene oxide (PO), and butylene oxide (BO), and cyclic ether compounds such as tetrahydrofuran (THF).

[0037] The polyether polyol is preferably a polyoxyalkylene polyol having an alkyleneoxy group. Suitable examples include EO-modified trimethylolpropane, PO-modified trimethylolpropane, tetrahydrofuran-modified trimethylolpropane, EO-modified glycerin, PO-modified glycerin, tetrahydrofuran-modified glycerin, polyethylene glycol, polypropylene glycol, polyoxypropylene glyceryl ether, etc. Among these, EO-modified trimethylolpropane, PO-modified trimethylolpropane, EO-modified glycerin, PO-modified glycerin, polyethylene glycol, polypropylene glycol, and polyoxypropylene glyceryl ether are preferred. The terms EO-modified and PO-modified refer to (poly)alkylene oxide modifications such as ethylene oxide modification and propylene oxide modification, and refer to the addition of (poly)alkylene oxide units.

[0038] Commercially available polyether polyols include Sannix TP-400 (Mn: 400), Sannix GP-250 (Mn: 250), Sannix GP-400 (Mn: 400), Sannix GP-600 (Mn: 600), Sannix GP-1000 (Mn: 1000), Sannix PP-200 (Mn: 200), Sannix PP-400 (Mn: 450), Sannix PP-600 (Mn: 600), Sannix PP-1000 (Mn: 1000), Examples of such copolymers include PEG-200 (Mn: 200), PEG-400 (Mn: 400), PEG-600 (Mn: 600), and PEG-1000 (Mn: 1000) (all manufactured by Sanyo Chemical Industries, Ltd.), Exenol 430 (Mn: 430), Exenol 1030 (Mn: 1000), Exenol 420 (Mn: 400), Exenol 720 (Mn: 700), Exenol 1020 (Mn: 1000), and Exenol 2020 (Mn: 2000) (all manufactured by AGC).

[0039] The polyol (B) has a number average molecular weight (Mn) of 2000 or less. By making the Mn of the polyol (B) 2000 or less, dispersibility in the coating material can be improved, and processing adhesion can be made even better. It is more preferably 1700 or less, and even more preferably 1500 or less. The lower limit of the molecular weight of the polyol (B) is not particularly limited, but from the viewpoint of improving curability, it is preferably 100 or more, more preferably 200 or more, and even more preferably 300 or more.

[0040] From the viewpoint of achieving superior processing adhesion and antibacterial properties, the content of polyol (B) is preferably 2 parts by mass or more per 100 parts by mass of cationically polymerizable compound (A). It is more preferably 3 parts by mass or more, and even more preferably 5 parts by mass or more. Furthermore, from the viewpoint of improving curability, it is preferably 30 parts by mass or less. It is more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less.

[0041] The polyol (B) can be used alone or in combination of two or more. The polyol (B) is a compound having two or three hydroxyl groups per molecule, but this does not exclude the inclusion of a polyol having one or four or more hydroxyl groups per molecule in the coating material within the scope of the present invention.

[0042] [Cationic photoinitiator (C)] The cationic photopolymerization initiator (C) refers to a compound that, when irradiated with actinic rays, releases a cation that initiates the polymerization or crosslinking reaction of the cationically polymerizable compound (A).

[0043] A variety of cationic photoinitiators (C) are known, including diazonium compounds, sulfonium compounds, iodonium compounds, and metal complex compounds. Detailed descriptions can be found in "Functional Materials," October 1985, item 5, and "Applications and Markets of UV / EB Curing Technology," CMC, 1989, page 78. Specific examples include triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluorophosphate, triphenyliodonium hexafluoroantimonate, diphenyl(4-(phenylthio)phenyl)sulfonium hexafluoroantimonate, bis(4-(diphenylsulfonio)phenyl)sulfide bis(hexafluoroantimonate), diphenyl(4-(phenylthio)phenyl)sulfonium hexafluorophosphate, and bis(4-(diphenylsulfonio)phenyl)sulfide bis(hexafluorophosphate). Cationic photoinitiators (C) can be used singly or in combination.

[0044] Commercially available products containing the cationic photopolymerization initiator (C) include, for example, CPI-100P (50% active ingredient), CPI-101A (50% active ingredient), CPI-200K (50% active ingredient), CPI-110B (100% active ingredient), CPI-310FG (100% active ingredient), CPI-310B (100% active ingredient), CPI-410S (100% active ingredient), and CPI-410B (100% active ingredient). ), IK-1 (active ingredient 100%) (all manufactured by San-Apro Co., Ltd.), Omnicat 250 (active ingredient 75%), Omnicat 270 (active ingredient 100%), Omnicat 432 (active ingredient 45%) (all manufactured by IGM), WPI-113 (active ingredient 50%) (manufactured by Wako Pure Chemical Industries, Ltd.), AT-6992 (active ingredient 60%), AT-6976 (active ingredient 60%) (all manufactured by Aceto).

[0045] The content of the cationic photopolymerization initiator (C) is 3 to 15 parts by mass per 100 parts by mass of the total of the cationic polymerizable compound (A) and polyol (B). By using this range in the coating material, a topcoat coating film that is a cured film with excellent curability even at low exposure doses can be obtained. In addition, the cure shrinkage and cure speed can be optimized to obtain a coating film with excellent adhesion to the coated surface. Furthermore, a topcoat coating film with excellent adhesion after processing can be obtained. The content of the cationic photopolymerization initiator (C) is preferably 4 to 13 parts by mass, and more preferably 5 to 12 parts by mass.

[0046] [Trifunctional radical polymerizable monomer (D)] The radical polymerizable monomer (D) is a monomer having three functional groups per molecule that are radically polymerizable and / or crosslinkable. The presence or absence of other functional groups and the number of functional groups are not limited. The content of the radical polymerizable monomer (D) is 5 to 35% by mass relative to 100% by mass of the total of the cationically polymerizable compound (A), polyol (B), and radical polymerizable monomer (D). By making the content 5% by mass or more, excellent adhesion to various surfaces to be coated can be achieved. Furthermore, excellent adhesion after processing can be achieved. Furthermore, by making the content 35% by mass or less, distortion during curing can be reduced. A more preferred range is 6 to 32% by mass, and an even more preferred range is 7 to 30% by mass.

[0047] Suitable examples of the polymerizable group and / or crosslinkable group of the radical polymerizable monomer (D) include a (meth)acryloyl group and a vinyl group. The use of a bifunctional radical polymerizable monomer tends to result in reduced curability, while the use of a tetrafunctional or higher functional radical polymerizable monomer tends to result in reduced adhesion during processing. The use of a trifunctional radical polymerizable monomer (D) provides a coating film that combines curability, adhesion, and post-processing adhesion. The radical polymerizable monomer (D) may be used alone or in combination of two or more. The use of a bifunctional radical polymerizable monomer and a tetrafunctional or higher functional radical polymerizable monomer is not excluded within the spirit of the present invention.

[0048] Examples of the radical polymerizable monomer (D) having a (meth)acryloyl group include trimethylolpropane tri(meth)acrylate, trimethylolpropane ethyleneoxy-modified tri(meth)acrylate, propyleneoxy-modified trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and isocyanuric acid ethyleneoxy-modified tri(meth)acrylate.

[0049] Examples of the radically polymerizable monomer (D) having a vinyl group include trimethylolpropane trivinyl ether and ethyleneoxy-added trimethylolpropane trivinyl ether (TMPEOTVE).

[0050] [Radical photopolymerization initiator (E)] The radical photopolymerization initiator (E) is a compound that releases radicals that initiate the polymerization or crosslinking reaction of the radical polymerizable monomer (D) when irradiated with actinic rays. The content of the radical photopolymerization initiator (E) is 1 to 10 parts by mass per 100 parts by mass of the radical polymerizable monomer (D). By using this range, poor curing can be prevented and an excellent cured film can be obtained. The radical photopolymerization initiator (E) is not particularly limited, and known compounds can be used. Specific examples include benzophenone compounds, dialkoxyacetophenone compounds, α-hydroxyalkylphenone compounds, α-aminoalkylphenone compounds, and acylphosphine oxide compounds.

[0051] Examples of benzophenone compounds include benzophenone, 4-methylbenzophenone, 4-phenylbenzophenone, 4,4'-bis(diethylamino)benzophenone, 4,4'-bis(dimethylamino)benzophenone, [4-(methylphenylthio)phenyl]-phenylmethanone, methyl benzophenone-2-carboxylate, and compounds having two or more benzophenone structures.

[0052] Examples of the dialkoxyacetophenone compounds include 2,2-dimethoxy-2-phenylacetophenone, dimethoxyacetophenone, and diethoxyacetophenone.

[0053] Examples of α-hydroxyalkylphenone compounds include 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, and 2-hydroxy-1-[4-(2-hydroxyethoxy)-phenyl]-2-methyl-1-propan-1-one.

[0054] Examples of α-aminoalkylphenone compounds include 2-methyl-1-[4-(methoxythio)-phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl-1-butanone, and compounds having two or more α-aminoalkylphenone structures.

[0055] Examples of the acylphosphine oxide compounds include diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

[0056] From the viewpoint of the transparency of the cured coating film, it is preferable to use a compound selected from the group consisting of α-hydroxyalkylphenone compounds and acylphosphine oxide compounds.

[0057] Commercially available products include Omnirad 184, 907, 651, 1173, 819, 369E, and TPO H (all manufactured by IGM). The radical photopolymerization initiator (E) may be used alone or in combination of two or more.

[0058] [Polydimethylsiloxane leveling agent (F)] The polydimethylsiloxane leveling agent (F) (hereinafter referred to as "leveling agent (F)") improves the wettability of the underlying layer of this paint with the surface to be coated, making the topcoat film obtained from this paint even flatter. By using the leveling agent (F), it is possible to more appropriately adjust the adhesion to the surface to be coated (primer film, intermediate layer such as ink layer).

[0059] Examples of the leveling agent (F) include polyether-modified polydimethylsiloxanes (those without hydroxyl groups and acryloyl groups, those with hydroxyl groups, and those with acryloyl groups), polyester-modified polydimethylsiloxanes (those without hydroxyl groups and acryloyl groups, those with hydroxyl groups, and those with acryloyl groups), and polyetherester-modified polydimethylsiloxanes (those without hydroxyl groups and acryloyl groups, those with hydroxyl groups, and those with acryloyl groups). The leveling agents (F) may be used alone or in combination.

[0060] Commercially available leveling agents (F) include BYK333, 377, 378, UV3500, and UV3510 (all manufactured by BYK), and TEGO Glide410, 435, and 450 (all manufactured by Evonic).

[0061] The content of the leveling agent (F) can be appropriately selected depending on the type of surface to be coated or the type of protective coating film to be formed on top. From the viewpoint of maintaining good wettability and permeability to the surface to be coated, the content of the leveling agent (F) is preferably 0.005 parts by mass or more per 100 parts by mass of the total of the cationically polymerizable compound (A), polyol (B), cationic photopolymerization initiator (C), radically polymerizable monomer (D), and radical photopolymerization initiator (E). It is more preferably 0.01 parts by mass or more, and even more preferably 0.02 parts by mass or more.

[0062] As described below, a protective coating may be partially formed on the topcoat. Information such as expiration dates may also be printed on the topcoat by inkjet printing or other methods. For this reason, the topcoat is also required to have excellent adhesion to the protective coating or other overlying layers, such as printed information. To ensure excellent adhesion to the surface to be coated and excellent adhesion to layers formed on the topcoat, the content of the leveling agent (F) is preferably 2 parts by mass or less per 100 parts by mass of the total of the cationic polymerizable compound (A), polyol (B), cationic photopolymerization initiator (C), radically polymerizable monomer (D), and radical photopolymerization initiator (E). Setting the amount of the leveling agent within this range also enhances the dispersibility of the leveling agent (F) within the cured film when the coating material is applied to form a cured film. The content is more preferably 1 part by mass or less, and even more preferably 0.8 parts by mass or less.

[0063] <Silver compound (G)> The silver-based compound (G) component of the present invention is a compound containing silver. The silver-based compound (G) functions as an antibacterial agent and can also function as an active ingredient of an antiviral agent, an antifungal agent, or a deodorizer. Therefore, a topcoat film using the silver-based compound (G) can exhibit antiviral effects in addition to antibacterial effects.

[0064] The mechanism by which the topcoat coating of the present invention exhibits antibacterial properties is believed to be as follows: When the silver-based compound (G) comes into contact with moisture, the slight moisture permeability of the polyol (B) allows moisture to penetrate into the silver-based compound. This moisture causes silver ions to elute. The amount of eluted silver ions remains approximately constant over a certain period of time. These positively charged silver ions are attracted to the negatively charged surface of bacteria. This disrupts the electrical balance on the surface of bacteria, rupturing the cell membrane and killing the bacteria. The silver ions then penetrate into cells and bind to intracellular enzymes, thereby inactivating the enzymes. They also react with bacterial DNA, causing it to lose its function and reducing its reproductive ability. It is believed that this antibacterial effect of silver ions completely prevents the proliferation of bacteria on the surface of the coating layer.

[0065] Examples of the silver-based compound (G) include silver compounds such as simple silver, silver oxide, inorganic silver salts such as silver carbonate, silver chloride, silver nitrate, silver sulfate, and silver sulfonate, and organic silver salts such as silver formate and silver acetate. The silver salts may also be supported on zeolite, silica gel, low-molecular-weight glass, calcium phosphate, silicate, molybdenum oxide, titanium oxide, and the like (supported compounds are also referred to as supported compounds or supports). Examples of the support include zeolite-based silver-supported compounds, silica gel-based silver-supported compounds, silicate-based silver-supported compounds, molybdenum oxide-based silver-supported compounds, and titanium oxide-based silver-supported compounds, which support silver compounds such as simple silver, silver oxide, inorganic silver salts, and organic silver salts.

[0066] From the viewpoint of dispersion stability, the silver-based compound (G) is preferably a support in which elemental silver, silver oxide, or an inorganic silver salt such as silver nitrate is supported on a carrier, and more preferably a zeolite-based silver-supported compound or a molybdenum oxide-based silver-supported compound in which a silver compound is supported on zeolite or molybdenum oxide. Zeolite-based silver-supported compounds and molybdenum oxide-based silver-supported compounds are preferred because they have excellent antibacterial and antiviral properties.

[0067] The average primary particle size of the silver-based compound (G) used in the present invention is preferably 5 to 100 nm. The average primary particle size can be measured by directly observing the particles themselves using, for example, a transmission electron microscope (TEM) or a scanning electron microscope (SEM). An average primary particle size of 5 nm or more improves dispersibility, and an average primary particle size of 100 nm or less can form a cured film with better transparency.

[0068] The content of the silver-based compound (G) relative to 100 parts by mass of the total of the cationically polymerizable compound (A), polyol (B), and radically polymerizable monomer (D) of the present invention is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 1.0 to 7 parts by mass. A content of 0.1 part by mass or more makes it possible to obtain a better antibacterial coating film, while a content of 20 parts by mass or less makes it easy to form a coating film with excellent dispersion stability.

[0069] It is preferable to prepare the paint with the silver-based compound (G) as a dispersion. The silver-based compound (G) is dispersed in a liquid mixture in which the cationic polymerizable compound (A), polyol (B), trifunctional radical polymerizable monomer (D), and diluent (described later) are mixed in advance with the silver-based compound (G), and the remaining components are then blended to prepare the paint. It is preferable to blend a dispersant to stabilize the dispersion state of the silver-based compound (G). The dispersed particle size D of the silver-based compound (G) in the paint is 50 The dispersed particle size D is preferably 300 nm or less, and more preferably 200 nm or less. 50 Dispersed particle size D can be measured using the dynamic light scattering method with the "Nanotrack UPA" manufactured by Nikkiso Co., Ltd. 50 When the diameter is 300 nm or less, the dispersion stability can be improved.

[0070] Dispersion can be performed using a dispersing machine such as a paint conditioner (manufactured by Red Devil), a ball mill, a sand mill (such as the "Dyno Mill" manufactured by Shinmaru Enterprises), an attritor, a pearl mill (such as the "DCP Mill" manufactured by Eirich), a Coball mill, a homomixer, a homogenizer (such as the "Clearmix" manufactured by M-Technique), a wet jet mill (such as the "Genus PY" manufactured by Genus and the "Nanomizer" manufactured by Nanomizer), or a microbead mill (such as the "Super Apec Mill" or "Ultra Apec Mill" manufactured by Kotobuki Industries Co., Ltd.). When using media in a dispersing machine, glass beads, zirconia beads, alumina beads, magnetic beads, or styrene beads are preferred. It is acceptable to use two or more types of dispersing machines or two or more types of media of different sizes in a stepwise manner.

[0071] <Optional ingredients> The paint may contain an optional diluent. While the diluent is not limited, suitable examples include methyl propylene glycol and propylene carbonate. Depending on the application, the paint may also contain components that impart a gloss or matte finish. The coating material may also contain a photosensitizer (polymerization accelerator) as an optional component. Examples of photosensitizers include amine compounds such as triethanolamine, methyldiethanolamine, triethylamine, and diethylamine; thioxanthone, thioxanthone derivatives, anthraquinone, anthraquinone derivatives, anthracene, anthracene derivatives, perylene, perylene derivatives, benzophenone, and benzoin isopropyl ether.

[0072] Furthermore, other cationically polymerizable compounds and / or radically polymerizable monomers may be added to the coating composition without departing from the spirit of the present invention. Furthermore, other leveling agents than the leveling agent (F) may be added without departing from the spirit of the present invention. Furthermore, wettability improvers, surfactants, plasticizers, ultraviolet absorbers, silane coupling agents, inorganic fillers, resin particles, pigments, dyes, etc. may also be added.

[0073] <Surface tension of this paint, surface free energy of topcoat> From the viewpoint of more effectively improving adhesion to various surfaces to be coated (undercoat films, ink layers, etc.), the surface tension of the present coating material is preferably 29 mN / m or less. It is more preferably 28.5 mN / m or less, and even more preferably 27.5 mN / m or less. The surface tension can be adjusted by adjusting the type and amount of the leveling agent (F) or the type and amount of the diluent. The lower limit of the surface tension is not particularly limited, but is usually 20 mN / m or more.

[0074] In addition, the surface free energy of the topcoat film that has been applied and cured by light irradiation is set to 25 mJ / m from the viewpoint of improving adhesion to the above-mentioned upper layer film. 2 It is preferable that the intensity is 26.5 mJ / m or more. 2 More preferably, 28 mJ / m 2 The surface free energy of the topcoat film can be adjusted by adjusting the type and amount of the leveling agent (F) or the type and amount of wax. The upper limit of the surface free energy is not particularly limited, but is usually 60 mJ / m 2 The following is the result.

[0075] The surface tension of this paint is 29mN / m or less, and the surface free energy of the top coat is 25mJ / m 2 When the above-mentioned features are combined, it becomes possible to more effectively improve adhesion to the undercoat film and ink layer, while significantly increasing the options for materials to be formed on the topcoat film.

[0076] [[Laminate and manufacturing method thereof]] The laminate according to this embodiment (hereinafter also referred to as "the laminate") has at least a substrate and a topcoat film formed on the substrate. This topcoat film is a cured product of the present paint. Examples of the substrate include metal, plastic, glass, ceramics, and wood. Any layer, such as a primer film or an intermediate layer such as an ink layer, can be formed between the substrate and the topcoat film.

[0077] Fig. 1 shows a schematic top view of an example of the present laminate, and Fig. 2 shows a cross-sectional view taken along line II-II in Fig. 1. As shown in Fig. 2, the laminate 10 comprises, in this order, a metal substrate 20, an undercoat film 30, an ink layer 40, and a topcoat film 50. The topcoat film 50 serves as a topcoat layer, as shown in Fig. 1. The production of the laminate 10 includes steps of forming the undercoat film 30 on the metal substrate 20, forming the ink layer 40 on the undercoat film 30, applying the present paint onto the undercoat film 30 and the ink layer 40, and curing the paint by irradiation with actinic light to form the topcoat film 50.

[0078] The integrated light amount for the curing treatment of the topcoat coating film 50 can be appropriately designed. For example, in the case of the present paint, it is 200 mJ / cm 2 By irradiating the coating with light in the wavelength range of 320 nm or more and 390 nm or less, it is possible to provide a topcoat coating film with excellent curability and excellent properties. The lower limit of the accumulated light dose is not particularly limited as long as it can be cured. For example, 50 mJ / cm 2 That's about it.

[0079] The laminate 10 may further include other layers. The laminate 10 has uncoated regions 21, which are to be joined, at both lateral ends (X direction in FIG. 1 ), where the metal substrate 20 is exposed in a linear pattern along the Y direction. This laminate 10 is joined by overlapping the uncoated regions 21 at both ends to form a packaging container member 60, which is a cylindrical welded can as shown in FIG. 4, which will be described later. Providing the uncoated regions 21, where the metal substrate 20 is exposed and not covered with the primer coating film 30 or the like, can prevent poor welding when the welded can is formed.

[0080] The material of the metal substrate 20 is not particularly limited, and examples thereof include tin plate, chrome-plated steel plate, aluminum plate, aluminum alloy plate, surface-treated steel plate such as tin-free steel, aluminum-plated steel plate, nickel-plated steel plate, tin-nickel-plated steel plate, and various alloy-plated steel plates. Alternatively, the metal substrate may be a resin-coated metal plate on which a film made of a thermoplastic resin such as polyester is formed. When a resin-coated metal plate is used as the metal substrate, the resin layer to be coated may contain a white pigment.

[0081] The primer coating film 30 may be configured as a single layer as shown in Figure 2, or may be configured as two layers or three or more layers as shown in Figure 3. When there are two layers of primer coating film 30 as shown in Figure 3, the coating film of the primer coating film 30 that is in direct contact with the metal substrate 20 for the most part will be referred to as the first primer coating film 31, and the coating film further provided on the first primer coating film 31 will be referred to as the second primer coating film 32 for the sake of convenience.

[0082] The first undercoat film 31 can be formed by a known method. For example, the first undercoat film 31 can be formed by applying an undercoat paint for the first undercoat film onto the metal substrate 20, drying it, and curing it. The second undercoat film 32 can be formed by applying, drying, and curing a paint for the second undercoat film on the first undercoat film 31. The paint for the second undercoat film 32 may be applied directly to a portion of the metal substrate 20, dried, and cured. The paint for the first and second primer coating films (hereinafter sometimes referred to as primer paint) can be a composition in which a binder component is dissolved or dispersed in a solvent. A thermosetting compound or a photocurable compound is suitable as the binder component. When a binder component containing a thermosetting compound is used, the primer paint is applied, dried, and then cured by heat. When a binder component containing a photocurable compound is used, the primer paint is cured by irradiation with actinic rays. A thermosetting compound and a photocurable compound may be used in combination. The primer paint can contain a colorless inorganic filler or a colored pigment. For example, an example of a colorless inorganic filler is silica, and an example of a white pigment is titanium dioxide.

[0083] The thickness of the first undercoat coating film 31 and the second undercoat coating film 32 is not particularly limited. The mass per unit area of ​​each coating film is, for example, 1 to 300 mg / dm 2 When the main purpose is to conceal the background color of the metal substrate 20, the concentration can be, for example, 40 to 300 mg / dm 2 It can be said that:

[0084] In the example of the laminate 10 shown in FIG. 3, the ink layer 40 is composed of two layers: a first ink layer 41 and a second ink layer 42. The ink layer may be formed from a single layer or may be formed from multiple layers (more than two layers). The ink layer 40 can be used to form a pattern on the metal substrate or to form a colored layer. The ink layer 40 may be formed over the entire surface of the primer coating film, or may be formed at a desired position as shown in FIG. 3.

[0085] The ink layer 40 can be obtained by plate printing, such as offset printing or screen printing, in which multiple plates are prepared to perform multicolor printing, or inkjet printing, which uses ink droplets sprayed from an ink head. Plate printing and inkjet printing can also be used in combination. In plate printing, when the ink layer is composed of multiple layers, each layer is cured separately. Alternatively, each layer can be provisionally cured, and then the final curing process can be performed after the multiple layers are stacked.

[0086] The ink layer 40 can be obtained, for example, by applying an ink containing a binder component (such as a binder component containing a thermosetting compound, a binder component containing an oxidatively polymerizable compound, or a binder component containing a photocurable compound) and a pigment onto the undercoat film 30 and curing it to form a cured film. Known compounds can be used as the binder component for the ink. Examples include alkyd resin, polyester resin, and epoxy resin. The pigment can be either an organic pigment or an inorganic pigment. A curing agent can also be added as necessary. Optional components such as pigment dispersants, waxes, and stabilizers can also be added.

[0087] There are no limitations on the thickness of each of the first ink layer 41 and the second ink layer 42, but it can be, for example, about 0.1 to 6 μm. In the example of Fig. 3, for example, the first ink is applied to the second undercoat film 32, dried, and cured to form the first ink layer 41, and then the second ink is applied to a desired position, dried, and cured to form the second ink layer 42, thereby obtaining the ink layer 40.

[0088] The topcoat film 50 is formed on the undercoat film 30 and the ink layer 40 so as to cover them. The photocurable topcoat paint of the present paint is applied onto the undercoat film 30 and the ink layer 40 of the laminate 10, and is cured by irradiation with actinic rays to form the topcoat film 50. For coating, a known coating device can be used, such as a Mayer bar, applicator, brush, spray, roller, gravure coater, die coater, microgravure coater, lip coater, comma coater, curtain coater, knife coater, reverse coater, or spin coater. The light source of actinic rays can be appropriately selected. In the case of irradiating ultraviolet rays, examples of the light source include a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, an LED lamp, a xenon lamp, and a metal halide lamp.

[0089] The thickness of the topcoat film can be appropriately selected depending on the application, but is preferably 2 to 20 μm, more preferably 3 to 15 μm.

[0090] <Modification> Other examples of the laminate include a laminate having a metal substrate, an undercoat coating film, and a topcoat coating film laminated in this order, and a laminate having a topcoat coating film formed directly on a metal substrate.In addition, paper, plastic film, wood material, glass, stone, etc. can also be used as the substrate instead of a metal substrate.

[0091] [[Packaging container components and their manufacturing methods]] The packaging container member according to this embodiment has a member formed using the present laminate. Fig. 4 is a schematic perspective view showing an example of the packaging container member, and Fig. 5 is a partially enlarged explanatory view of the cross section of region V in Fig. 4. The packaging container member 60 is a cylindrical body made of the present laminate, and the outer surface of this cylindrical body is coated with a top coat film 50 formed using the present paint. The cylindrical body has a seam 61. The seam 61 of the packaging container member 60 is formed by overlapping and joining the uncoated regions 21, which are to be welded at both ends of the laminate 10 in the X direction, shown in Fig. 1. A protective coating film 62 is formed on the seam 61 on the outer surface 22 of the cylindrical body (see Fig. 5).

[0092] As shown in FIG. 5, the protective coating film 62 covers the area from the seam 61 on the outer surface 22 of the metal substrate 20 at its center to the upper surface of the edge of the adjacent topcoat coating film 50. This protects and reinforces the seam 61 and enhances the aesthetic appeal of the packaging container member. An inner protective layer (not shown) may be formed on the inner surface 23 of the metal substrate 20. The protective coating film 62 may be formed by a known method. For example, it may be obtained by applying and drying a protective paint. Alternatively, the protective coating film 62 may be cured by heat or light after drying to form a cured film. Alternatively, a protective tape may be applied instead of the protective coating film.

[0093] In addition to the above-mentioned methods, various known methods such as welding, adhesives, soldering, and crimping can be used to join the laminate 10 into a cylindrical body. FIG. 6 shows a schematic top view of the crimped portion of packaging container members joined by crimping. As shown in the figure, both ends of the laminate 10 in one direction are overlapped, folded, and wrapped to join the cylindrical body. In the laminate 10, the outer side of the packaging container member 60 is the top coat film 50, and the inner side is the metal substrate 20. Note that when joining by crimping, a laminate may be used in which the uncoated region 21 (see FIG. 1) is not provided, and the undercoat film 30, ink layer 40, and top coat film 50 are provided on the entire surface of the metal substrate 20. Furthermore, when joining by crimping, a protective coating film to cover the joint is not required.

[0094] The cylindrical packaging container member 60 functions as the can body. When manufacturing a three-piece can, a packaging container member (not shown) can be used in which a bottom member that closes the lower opening of the cylindrical body that becomes the can body is joined by welding or the like. The packaging container member can be suitably used as a packaging container member for canned goods or a packaging container member for spray cans.

[0095] <Modification> Another example of a packaging container member of this embodiment is a packaging container member formed from an integrally molded product formed from the sheet-like present laminate and having a recessed peripheral wall and bottom surface. A top coat film formed from the present paint is formed on the outer surface of this integrally molded product. This can be suitably used as a packaging container member for two-piece cans that contain food or the like. Since this laminate uses a top coat film that has excellent adhesion after processing, it can also be suitably used as a packaging container member having such an integrally molded product. In the above embodiment, an example was given in which a metal can was formed using a laminate, but after the metal can was formed, the present coating material can also be used for applications in which a topcoat coating film or the like is formed by applying the coating material to the formed metal can using a spray, a roll, or the like.

[0096] [[Packaging containers]] The packaging container of this embodiment includes a container body having the packaging container member of the present invention, and a lid member attached to the container body to cover the opening of the container body. The container body can be, as described above, a packaging container member in which a bottom member that closes the lower opening of a cylindrical body that becomes the can body is joined by welding or the like, or, as described in the modified example, a packaging container member in which the cylindrical peripheral wall and bottom are integrally molded. The opening of the container body refers to the opening for removing the contents contained in the container body. The lid member can be attached to the container body, as in the case of a pull-tab can, or it can be a recessed lid that can be opened and closed freely and is made of a single part, as described in Figure 7. [Example]

[0097] The present invention will be described in more detail below, but the following examples are not intended to limit the scope of the invention. In the examples, "parts" and "%" represent "parts by mass" and "% by mass", respectively, unless otherwise specified.

[0098] The average primary particle size of the silver-based compound (G) and the dispersed particle size of the silver-based compound (G) were measured by the following method.

[0099] [Average primary particle size of silver-based compound (G)] The average primary particle diameter was determined by observing with a transmission electron microscope (TEM) using a JEM-2010 transmission electron microscope manufactured by JEOL Ltd., measuring the minor axis diameter and major axis diameter of 10 primary particles, and averaging the measurements to determine the average primary particle diameter.

[0100] [Dispersed particle size of silver-based compound (G)] Dispersed particle size D 50 was measured using the dynamic light scattering method with "Nanotrac UPA" manufactured by Nikkiso Co., Ltd. <Production of Silver-Based Compound Dispersion> (Silver-based compound dispersion 1) A dispersion of silver ions-loaded zeolite was prepared in the following manner. 200 parts of silver ion-supported zeolite (Novalon AGT330, manufactured by Toagosei Co., Ltd.), 10 parts of DisperBYK-111 (manufactured by BYK Japan Co., Ltd.) as a dispersant, and 800 parts of Celloxide 2021P (manufactured by Daicel Corporation) were mixed and dispersed under the following conditions. The average primary particle diameter was 30 nm, and the dispersed particle diameter D 50 Dispersion 1 containing a silver-based compound (GI) having a particle size of 80 nm was prepared. Pre-dispersion: Disperse for 1 hour using zirconia beads (1.25 mm) as the medium in a paint shaker. Main dispersion: Zirconia beads (0.1 mm) were used as media and the mixture was dispersed for 1 hour using a Kotobuki Industries Co., Ltd. disperser UAM-015.

[0101] (Silver-based compound dispersion 2) A dispersion of silver ions-loaded molybdenum oxide was prepared in the following manner. 195 parts of sodium molybdate dihydrate (Kanto Chemical Co., Ltd.) was dissolved in 3000 parts of ion-exchanged water, and a solution of 273 parts of silver nitrate (Kanto Chemical Co., Ltd.) dissolved in 3000 parts of ion-exchanged water was added dropwise to the solution over 30 minutes while stirring to obtain a precipitate. This was filtered, washed with ion-exchanged water, and thoroughly dried at 100°C. 200 parts of this was used instead of Novalon AGT330 in Silver-Based Compound Dispersion 1, and a dispersion having an average primary particle size of 25 nm and a dispersion particle size D 50 Dispersion 2 containing a silver-based compound (GII) having a particle size of 70 nm was prepared.

[0102] (Silver-based compound dispersion 3) A dispersion of silver ions-loaded zeolite was prepared in the following manner. A silver-based compound dispersion having an average primary particle size of 30 nm and a dispersed particle size D 50 Dispersion 3 containing a silver-based compound (GIII) having a particle size of 90 nm was prepared.

[0103] (Silver-based compound dispersion 4) A dispersion of silver ion-loaded silicate was prepared in the following manner. The average primary particle size was 40 nm and the dispersion particle size D 50 Dispersion 4 was prepared containing a silver-based compound (GIV) having a particle size of 110 nm.

[0104] [Example 1] The components shown in Table 1 were blended to obtain photocurable topcoat paint N1 according to Example 1. In Table 1, the blending amount of each component is in parts by mass. Specifically, 13.89 parts of the silver-based compound dispersion 2 (containing 2.75 parts of the silver-based compound (GII)) was mixed with 49.67 parts of a bifunctional alicyclic epoxy compound, "Celloxide 2021P (manufactured by Daicel Corporation)" as the cationic polymerizable compound (A), for a total addition amount of 60.67 parts of (A). Next, 20 parts of a bifunctional glycidyl ether, "RD-111 (manufactured by Aditya Corporation)" and 5.5 parts of a polyether polyol, "Excenol 420 (manufactured by AGC Corporation)" having two hydroxyl groups and a number average molecular weight of about 400, as the polyol (B) were mixed and stirred with a disperser. To this, 8 parts of "AT-6992 (manufactured by Aceto)" with a non-volatile content of 60% by weight (including 4.8 parts of cationic photopolymerization initiator (C)), 5.5 parts of the trifunctional radical polymerizable monomer "Miramer M3130 (manufactured by Miwon)" as the radical polymerizable monomer (D), 0.3 parts of "Omnirad 1173 (manufactured by IGM)" with a non-volatile content of 100% by weight as the radical photopolymerization initiator (E), and 0.03 parts of "BYK377 (manufactured by BYK)" with a non-volatile content of 100% by weight as the leveling agent (F) were blended in this order and stirred again with a disperser to produce the photocurable topcoat paint N1 of Example 1. The surface tension of the photocurable topcoat paint N1 was 28.7 mN / m. Using the obtained photocurable topcoat paint N1, laminates of test pieces I, II, and III described below were prepared and various evaluations were carried out.

[0105] <Surface tension of photocurable topcoat paint> The surface tension of the photocurable topcoat paint was measured by the plate method in an environment of 25°C using a surface tensiometer (CBVP-Z) manufactured by Kyowa Interface Science Co., Ltd.

[0106] [Examples 2 to 41], [Comparative Examples 1 to 12] Photocurable topcoat paints N2 to N41 and N101 to N111 were obtained in the same manner as in Example 1 according to the formulations shown in Tables 1 to 5, and laminates of test pieces I, II, and III were prepared for each photocurable topcoat paint, and various evaluations were performed.

[0107] The components in Tables 1 to 5 are as follows: (cationically polymerizable compound (A), etc.) AI: Celloxide 2021P, manufactured by Daicel Corporation, a bifunctional alicyclic epoxy compound. · AII: RD-111, manufactured by Aditya, difunctional glycidyl ether. AIII: Epogose BD(D), manufactured by Yokkaichi Synthetic Co., Ltd., bifunctional glycidyl ether. AIV: Aron Oxetane OXT-101, manufactured by Toagosei Co., Ltd., monofunctional oxetane. (Polyol (B), etc.) ·BI:Excenol420: AGC Corporation, a polyether polyol with two hydroxyl groups and a number average molecular weight of approximately 400. BII: Excenol 1030, manufactured by AGC, a polyether polyol with three hydroxyl groups and a number average molecular weight of approximately 1,000. · BIII: Sannix GP-400, manufactured by Sanyo Chemical Industries, Ltd., a polyether polyol having three hydroxyl groups and a number average molecular weight of approximately 400. BIV: Excenol 2020, manufactured by AGC, a polyether polyol with two hydroxyl groups and a number average molecular weight of approximately 2000. BV: Excenol 3020, manufactured by AGC, a polyether polyol with two hydroxyl groups and a number average molecular weight of approximately 3,000. BVI: K-Flex A-308, manufactured by King Co., a polyester polyol with two hydroxyl groups and a number average molecular weight of approximately 600. BVII: K-Flex 188, manufactured by King Co., a polyester polyol with two hydroxyl groups and a number average molecular weight of approximately 500. (Cationic Photopolymerization Initiator (C)) ·CI:AT-6992, Aceto, Triarylsulfonium Hexafluorophosphate Salts, (active ingredient 60%). CII: AT-6976, Aceto, Triarylsulfonium Hexafluoroantimonate Salts, (active ingredient 60%). (Radical polymerizable monomer (D), etc.) · DI: Miramer M3130 (trimethylolpropane ethyleneoxy modified triacrylate), manufactured by Miwon. DII: Visocat #295 (trimethylolpropane triacrylate), manufactured by Osaka Organic Co., Ltd. DIII: Aronix M-315 (isocyanuric acid ethyleneoxy-modified tri(meth)acrylate), manufactured by Toagosei Co., Ltd. DIV: KAYARAD DPHA (Dipentaerythritol Hexaacrylate): Manufactured by Nippon Kayaku Co., Ltd. (Radical Photopolymerization Initiator (E)) EI: Omnirad 1173 (active ingredient 100%) 2-hydroxy-2-methyl-1-phenyl-propan-1-one, manufactured by IGM EII: Omnirad 184 (active ingredient 100%) 1-hydroxy-cyclohexyl phenyl ketone, manufactured by IGM (Polydimethylsiloxane leveling agent (F) FI: BYK377 (100% active ingredient), manufactured by BYK, polyether-modified polydimethylsiloxane (with hydroxyl groups) FII: BYK-UV3500 (100% active ingredient), manufactured by BYK, polyether-modified polydimethylsiloxane (containing acryloyl groups) FIII: BYK333 (100% active ingredient), manufactured by BYK, polyether-modified polydimethylsiloxane (containing neither hydroxyl nor acryloyl groups) (Silver compound (G)) GI: Novalon AGT330 (silver ion-supported zeolite), manufactured by Toagosei Co., Ltd. GII: Produced using silver ion-supported molybdenum oxide, sodium molybdate dihydrate (Kanto Chemical Co., Ltd.), and silver nitrate (Kanto Chemical Co., Ltd.) GIII: Zeomic AJ10N (silver ion-supported zeolite), manufactured by Sinanen Zeomic Co., Ltd. GIV: AIS-NAZ320 (silver ion-supported silicate), manufactured by JGC Catalysts and Chemicals Co., Ltd.

[0108] [Table 1]

[0109] [Table 2]

[0110] [Table 3]

[0111] [Table 4]

[0112] [Table 5]

[0113] [Preparation of Test Piece I (Laminate Composed of Metal Substrate / Undercoat Coating 1 / Topcoat Coating)] Primer 1 ("S48-1281" (containing polyester resin and amino resin), manufactured by Toyochem Co., Ltd.) was applied to a tin plate having a thickness of 0.24 mm, and heated at 180°C for 10 minutes to form a coating of 20 mg / dm 2 Primer coating film 1 was obtained.

[0114] Next, the photocurable topcoat paints N1 to N41 and N101 to N111 obtained in Examples 1 to 41 and Comparative Examples 1 to 10 and 12 were applied onto the undercoat film 1, respectively, and irradiated with ultraviolet light under the following conditions to obtain a coating of 70 mg / dm 2 A topcoat coating of Irradiation conditions: JATEC UV irradiation device, 160W high-pressure mercury lamp, conveying speed 25m / min, cumulative UVA light intensity 100mJ / cm 2 .

[0115] The photocurable topcoat paint N110 of Comparative Example 10 did not provide a cured film under the above conditions. Therefore, a laminate was produced under changed conditions, and this laminate was designated Comparative Example 11. Specifically, the process up to coating was the same as in Comparative Example 10, and the photocurable topcoat paint N110 was used, with only the ultraviolet irradiation conditions changed. The ultraviolet irradiation conditions were as follows: the conveying speed was changed to 5 m / min, the accumulated light dose was 500 mJ / cm 2 It was decided.

[0116] For each laminate of Test Piece I, the surface free energy, initial curing property, adhesion, and adhesion after processing were evaluated according to the methods described below.

[0117] [Preparation of Test Piece II (Laminate consisting of Metal Substrate / Undercoat 1 / Ink Layer 1 / Topcoat)]

[0118] Primer coating film 1 was formed on a 0.24 mm thick tinplate in the same manner as for test piece I. Next, UV-curable ink 1 ("MDK UV Black M-1", manufactured by Toyo Ink Co., Ltd.) was printed on primer coating film 1, and then, using a 160 W high-pressure mercury lamp, the ink was irradiated at a conveying speed of 25 m / min with an integrated light intensity of 100 mJ / cm. 2 By irradiating UVA rays at 20mg / dm 2 Ink layer 1 was obtained.

[0119] Next, on the ink layer 1, 70 mg / dm of photocurable topcoat paints N1 to N41 and N101 to N111 were applied in the same manner as in the case of test piece I. 2 The surface free energy of each topcoat coating is shown in Table 6. In addition, as in the case of Test Piece I, the initial curing property, adhesion, and adhesion after processing were evaluated according to the methods described below.

[0120] <<Surface free energy of topcoat coating>> The surface free energy of the topcoat coating film of test piece I of each example and comparative example was determined using a contact angle meter (Drop Master) manufactured by Kyowa Interface Science Co., Ltd. Specifically, the contact angles of water, diiodomethane, and n-hexadecane with the topcoat coating film surface in an environment of 25°C were measured, and the surface free energy was calculated using the Kitazaki-Hata theory (Kitazaki, Hata, Journal of the Adhesion Society of Japan, Vol. 8, No. 3, (1972), etc.).

[0121] <<Initial cure of topcoat film on test pieces I and II>> Immediately after preparation of each test piece I and II, i.e., immediately after irradiation with ultraviolet light, the surface of the topcoat film of each test piece was touched with a finger, and the time required for the tackiness to disappear was determined. Tackiness refers to the degree of stickiness. The evaluation criteria were as follows. From the viewpoint of industrial productivity, a standard of 4.0 or higher is required. 5.0: Tack loss time is less than 3 seconds. 4.5: Tack loss time is between 3 and 7 seconds. 4.0: Tack loss time is between 7 and 10 seconds. 3.5: Tack disappearance time is 10 seconds or more but less than 15 seconds. 3.0: Tack disappearance time is between 15 and 20 seconds. 2.5: Tack disappearance time is between 20 and 25 seconds. 2.0: Tack disappearance time is between 25 and 30 seconds. 1.5: Tack disappearance time is between 30 seconds and 60 seconds. 1.0: The tackiness of the coating surface does not disappear even after 60 seconds or more.

[0122] <<Adhesion of topcoat film on test pieces I and II>> At least 3 minutes after preparation of each of the test specimens I and II (at least 3 minutes after UV irradiation), 25 grid-like notches were made at 2 mm intervals on the topcoat surface of each test specimen. Cellophane tape was applied to the entire grid, and the cellophane tape was then peeled off in a first peel test. Subsequently, new cellophane tape was applied to the same location on the sample, and a second peel test was conducted. After the two peel tests, the total peeled area (%) was calculated and evaluated according to the following criteria. For practical purposes, a standard of 4.0 or higher is required. The cellophane tape used was LP-18 manufactured by Nichiban Co., Ltd. 5.0:0% (no peeling). 4.5: Peeling area is less than 10%. 4.0: Peeling area is 10% or more but less than 20%. 3.5: Peeling area is 20% or more but less than 30%. 3.0: Peeling area is 30% or more but less than 40%. 2.5: Peeling area is 40% or more but less than 50%. 2.0: Peeling area is 50% or more but less than 60%. 1.5: Peeling area is 60% or more but less than 70%. 1.0: Peeling area is 70% or more.

[0123] <<Adhesion of the topcoat film on test pieces I and II after processing>> Test specimens I and II were each processed by dropping a core onto the back of a tinplate so that the topcoat surface was convex. Specifically, a Dupont impact tester was used, with the core tip having a 1 / 2-inch radius, a drop height of 50 cm, and a drop weight of 300 g. A peel test was then conducted twice on the topcoat surface of the processed area of ​​each test sample, in which cellophane tape was applied and peeled off. The cellophane tape was applied and peeled off from the same location. After two tests, the total peeled area (%) was calculated and evaluated according to the following criteria. For practical purposes, a rating of 4.0 or higher is required. 5.0:0% (no peeling). 4.5: Peeling area is less than 10%. 4.0: Peeling area is 10% or more but less than 20%. 3.5: Peeling area is 20% or more but less than 30%. 3.0: Peeling area is 30% or more but less than 40%. 2.5: Peeling area is 40% or more but less than 50%. 2.0: Peeling area is 50% or more but less than 60%. 1.5: Peeling area is 60% or more but less than 70%. 1.0: Peeling area is 70% or more.

[0124] <<Antibacterial properties of the topcoat film of test piece I>> The antibacterial properties of each test piece I sample were tested in accordance with the test method of JIS Z2801. A: Antibacterial activity value 3 or higher B: Antibacterial activity value 2 or more, less than 3 C: Antibacterial activity value less than 2

[0125] <<Antiviral properties of the topcoat of test piece I>> The antiviral properties of each test piece I sample were tested in accordance with the JISL1922 test method. A: Antiviral activity value of 3 or more B: Antiviral activity value 2 or more, less than 3 C: Antiviral activity value less than 2

[0126] [Preparation of Test Piece III (Test Piece with Protective Coating 1 Formed on a Laminated Body Consisting of Metal Substrate / Undercoat Coating 1 / Ink Layer 1 / Topcoat Coating)] A laminate consisting of a metal substrate / primer coating film 1 / ink layer 1 / topcoat coating film was prepared using the same procedure as for Test Piece II. Next, a protective coating "HX75-10R" (manufactured by Toyochem Co., Ltd.) was applied to the topcoat coating of this laminate using a bar coater #14, and the condition of the coating was observed after 1 minute. The coverage rate of the protective coating relative to the painted area was calculated and evaluated according to the following criteria. For practical purposes, a rating of 4.0 or higher is required.

[0127] 5.0: The protective coating is not repelled and the painted area is 100% covered with paint. 4.5: Protective paint coverage is 90% or more but less than 100%. 4.0: Protective paint coverage is 80% or more but less than 90%. 3.5: Protective paint coverage is 70% or more but less than 80%. 3.0: Protective paint coverage is 60% or more but less than 70%. 2.5: Protective paint coverage is 50% or more but less than 60%. 2.0: Protective paint coverage is 40% or more but less than 50%. 1.5: Protective paint coverage is 30% or more but less than 40%. 1.0: Protective paint coverage is less than 30%.

[0128] The evaluation results of each example and comparative example are shown in Tables 6 and 7.

[0129] [Table 6]

[0130] [Table 7]

[0131] [Examples 42 to 44] The following test pieces IV, V, and VI were prepared using the antibacterial photocurable topcoat paints N3, 12, and 16. The various physical properties of the topcoat films were evaluated in the same manner as for test pieces I, II, and III.

[0132] [Preparation of Test Piece IV (Laminated Body Consisting of Metal Substrate / Undercoat 2 / Topcoat)] Primer 2 (ZE-1500 (white paint containing polyester resin and amino resin), manufactured by Toyo Printing Inks) was used instead of Primer 1, the heating and drying time was changed to 170°C for 12 minutes, and the coating weight of the primer paint was changed to 150 mg / dm 2 Test piece IV (a laminate consisting of metal substrate / undercoat film 2 / topcoat film) was obtained in the same manner as test piece I, except that:

[0133] [Preparation of test piece V (laminated body consisting of metal substrate / undercoat film 2 / ink layer 1 / topcoat film)] An undercoat film 2 was formed on a 0.24 mm thick tinplate in the same manner as for test piece IV. Then, UV-curable ink 1 was printed on the undercoat film 2 under the same conditions as for test piece II to form a 20 mg / dm 2 An ink layer 1 of the above formula was obtained. Then, the photocurable topcoat paint of each Example and Comparative Example was applied onto this ink layer 1, and cured by irradiating with ultraviolet light under the same conditions as for Test Piece I, to obtain Test Piece IV (laminate) having a topcoat film. The obtained Test Piece IV was evaluated in the same manner as for Test Piece II.

[0134] [Preparation of test piece VI (laminated body consisting of metal substrate / undercoat film 1 / ink layer 2 / topcoat film)] Ink layer 2 was formed using heat-curable ink 2 (CPA-97 Ink, manufactured by Matsui Kagaku Co., Ltd.) instead of UV-curable ink layer 1, and ink layer 2 was cured by heating (heating at 160°C for 10 minutes) instead of UV irradiation. 2 A test piece VI (laminate) having the ink layer 2 was prepared.

[0135] Table 8 shows the results of evaluation of the initial curing property, adhesion and processing adhesion for each of test pieces IV to VI formed using the antibacterial light-curable topcoat paints N3, N12 and N16.

[0136] [Table 8]

[0137] It is confirmed that Comparative Example 1, which contains a high content of radical polymerizable monomer, has poor curability. It is also clear that Comparative Example 9, which does not contain polyol (B), has issues with processing adhesion. Similarly, Comparative Examples 10 and 11, which contain a low amount of cationic photopolymerization initiator (C), have issues with curability and processing adhesion. It is also clear that Comparative Example 12, which does not contain silver-based compound (G), does not exhibit antibacterial or antiviral properties. On the other hand, it is clear that the antibacterial photocurable topcoat paint of this example has excellent curability, excellent adhesion to underlying layers (undercoat film, ink layer, etc.), excellent processing adhesion, and antibacterial properties, even when irradiated with a low exposure dose. [Industrial Applicability]

[0138] The antibacterial photocurable topcoat paint of the present invention has excellent adhesion to underlayers (primer coatings, ink layers, etc.) made of various materials, and is therefore suitable for a wide range of applications where a topcoat film must be formed on a surface to be coated. For example, it is suitable as a photocurable topcoat paint for forming a topcoat film on art cans with printed metal substrates for storing sweets or tea, beverage cans such as beer cans, coffee cans, and fruit drink cans, food cans for fish, meat, and simmered foods, powdered milk cans, spray cans, etc. [Explanation of symbols]

[0139] 10: laminate, 20: metal substrate, 21: uncoated area, 22: outer surface side, 23: inner surface side, 30: primer coating film, 31: first primer coating film, 32: second primer coating film, 40: ink layer, 41: first ink layer, 42: second ink layer, 50: Top coat, 60: packaging container member, 61: joint, 62: protective coating film, 70: packaging container, 71: main body, 72: can body, 73: bottom member, 74: joint, 75: lid.

Claims

1. a cationically polymerizable compound (A) having an epoxy group; a polyol (B) which is a polyether polyol or polyester polyol having two or three hydroxyl groups in one molecule and having a number average molecular weight of 400 or more and 2,000 or less; a cationic photopolymerization initiator (C); a radical polymerizable monomer (D) having only trifunctional (meth)acryloyl groups; a radical photopolymerization initiator (E); Contains a polydimethylsiloxane-based leveling agent (F) and a silver-based compound (G), the content of the radical polymerizable monomer (D) is 5 to 35% by mass relative to 100% by mass of the total of the cationically polymerizable compound (A), the polyol (B), and the radical polymerizable monomer (D); the content of the cationic photopolymerization initiator (C) is 3 to 15 parts by mass relative to 100 parts by mass in total of the cationic polymerizable compound (A) and the polyol (B); the content of the radical photopolymerization initiator (E) is 1 to 10 parts by mass relative to 100 parts by mass of the radical polymerizable monomer (D); and the antibacterial activity value of the cured coating film according to JIS Z2801 is 2 or more. Antibacterial light-curing topcoat paint.

2. 2. The antibacterial photocurable topcoat paint according to claim 1, wherein the cured coating film has an antiviral activity value according to JIS L1922 of 2 or more.

3. 3. The antibacterial photocurable topcoat paint according to claim 1, which has a surface tension of 29 mN / m or less.

4. A laminate comprising a metal substrate, an undercoat coating film, an ink layer, and a topcoat coating film in this order, wherein the topcoat coating film is a cured product of the antibacterial photocurable topcoat paint according to any one of claims 1 to 3.

5. The surface free energy of the topcoat coating film is 25 mJ / m ２ The laminate according to claim 4, wherein the above-mentioned

6. A packaging container member comprising the laminate according to claim 4 or 5 in the form of a cylindrical body, the outer surface of said cylindrical body being coated with said topcoat coating film, and said cylindrical body having a seam.

7. 7. The packaging container member according to claim 6, wherein the outer surface of the cylindrical body is coated with a protective coating film on the joint.

8. 8. The packaging container member according to claim 6, further comprising a bottom member that closes an opening at the bottom of the cylindrical body.

9. 6. An integrally molded article formed from the laminate according to claim 4 or 5, wherein the inner surface side is concave due to the peripheral wall portion and the bottom surface portion, A packaging container member, wherein the outer surface of the integrally molded product is the topcoat coating film.

10. A packaging container comprising: a container body having the packaging container member according to claim 8 or 9; and a lid member attached to the container body to cover an opening of the container body.

11. A primer coating is formed on the metal substrate, forming an ink layer on the undercoat film; A method for producing a laminate, comprising applying the antibacterial photocurable topcoat paint according to any one of claims 1 to 3 onto the ink layer and curing it to form a topcoat film.

12. The step of curing the antibacterial photocurable topcoat paint is carried out with an integrated light amount of light in the wavelength range of 320 nm or more and 390 nm or less of 200 mJ / cm ２ The method for producing a laminate according to claim 11, wherein the method is carried out by irradiating the laminate so as to:

13. A primer coating is formed on the metal substrate, forming an ink layer on the undercoat film; an antibacterial photocurable topcoat paint according to any one of claims 1 to 3 is applied onto the ink layer and cured to form a topcoat film, thereby obtaining a laminate; Using the laminate, a cylindrical body is formed, the outer surface of which is the topcoat coating film, and the peripheral wall portion includes a seam; A method for manufacturing a packaging container member, comprising a step of covering the joint on the outer surface of the cylindrical body with a protective coating film.

14. A primer coating is formed on the metal substrate, forming an ink layer on the undercoat film; an antibacterial photocurable topcoat paint according to any one of claims 1 to 3 is applied onto the ink layer and cured to form a topcoat film, thereby obtaining a laminate; A method for manufacturing a packaging container member, comprising a step of using the laminate to form an integrally molded product whose inner surface is concave due to the peripheral wall portion and the bottom surface portion, and whose outer surface is the topcoat coating film.

15. The step of curing the antibacterial photocurable topcoat paint is carried out with an integrated light amount of light in the wavelength range of 320 nm or more and 390 nm or less of 200 mJ / cm ２ The method for producing a packaging container member according to claim 13 or 14, wherein the method is carried out by irradiating the material so as to satisfy the following conditions:

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