Method of decorating metal fittings and the fittings themselves

Abstract

The UV printing ensures that the decoration is securely fixed to the metal fittings. [Solution] In the present invention, a metal fitting 1 such as a bag clasp has a metal fitting body 10 and a decorative part 6 provided on the surface of the metal fitting body 10, wherein the decorative part 6 comprises, in order from the bottom layer, a surface modification layer, a primer layer, a UV printing layer that exhibits decoration, and a transparent top coat layer. The surface modification layer is a film of silicon dioxide fine particles attached to the surface of the metal fitting body 10, the UV printing layer is a layer printed with UV ink that hardens when irradiated with ultraviolet light, the primer layer is an adhesive layer that adheres the UV printing layer to the surface modification layer, and the top coat layer is formed of a glass coating agent.

Description

Technical Field

[0001] The present invention relates to a method for decorating a metal fitting and the metal fitting, and more particularly to a method for decorating a metal fitting such as a fastener attached to a bag and the metal fitting.

Background Art

[0002] (Background Art) Regarding leather products such as bags (handbags) and wallets that are carried and used, as one method of differentiating from other leather products, it is common to decorate the leather that constitutes the main body of the bag or wallet, and patterns are printed on the leather. In recent years, due to the influence of infectious diseases such as COVID-19, bags are often overly disinfected. Originally, leather is easily damaged by the penetration of alcohol or water for sterilization, but through the efforts of the leather product industry, improvements such as water-repellent and waterproof treatments have been made, and more products can repel alcohol and water. On the other hand, due to the above-mentioned water-repellent and waterproof treatments, it has become impossible to successfully fix the pattern even when trying to print a pattern on the leather. Under the above background, the inventor of the present application explored free expression for bags and focused on fasteners that can accentuate and enhance the bags.

[0003] Fasteners provided on bags such as handbags generally use metal ones, that is, metal fittings, such as hooks, rivets, and crimps. Therefore, the color of off-the-shelf fasteners attached to bags is limited to metallic colors such as silver (nickel), gold, antique gold, black nickel, etc., and does not give a novel feeling on the decorative surface. Among imported products, especially some fasteners made in China, there are those that paint the metal fitting with a paint like enamel to give a color other than metallic colors, but they are only painted with a single primary color and cannot be said to be highly decorative. It can be said that it is difficult to give a small fastener a novel color appearance other than the primary color with paint. On the other hand, if the fastener is made of resin, it may be relatively easy to change the color of the fastener to something other than a primary color by adjusting the mixture of pigments added to the resin.

[0004] However, the fasteners used in bags require strength, and resin fasteners made to the same dimensions as metal fittings cannot provide the same strength. If you try to achieve the same strength as metal fittings with resin, the fasteners will inevitably become thick and clunky, and if you dislike that clunkiness, you ultimately have no choice but to rely on metal fittings. As mentioned above, bag fasteners can only be made of metal, but on the other hand, in recent years there has been a growing demand for bags that are unique and personal, down to the smallest detail. Currently, the only way to enhance the decorative appeal of metal fittings is to add logos through metalworking. Even when adding logos to metal fittings, the reality is that it's only possible to produce a certain quantity (or place an order with a processing company) to create a mold for the logo, which requires a minimum order of 1000 pieces. Therefore, metalworking using molds was not a suitable means of meeting the individual needs of a small number of diverse designs required for differentiation.

[0005] The inventor of this application sought a free method of decorating the above-mentioned metal fittings and diligently investigated whether it would be possible to realize the decorations designed by a designer onto the metal fittings using UV printing with a UV printer. UV printing offers high color reproduction, and the phenomenon of changes in gloss and intensity of colors as the ink dries is less likely to occur. Furthermore, by instantly curing the ink with ultraviolet (UV) light, it is possible to express colors that match the designer's vision. UV printing, in particular, offers a faster drying time compared to oil-based printing, allowing for quicker transitions to the next stage of the process. Its fast-drying properties also make it possible to print on materials other than paper, such as PP (polypropylene), PET (polyethylene terephthalate), and PC (polycarbonate). As an example of the above-mentioned UV printers, inkjet printers that print using UV ink that hardens under ultraviolet light are becoming widespread and are already being used to print designs on plastic cases and plates, such as protective cases for smartphones (Patent Document 1).

[0006] Furthermore, with UV printers, design data can be entered using the included software, allowing for free printing of designs based on the entered data. UV printing using a UV printer makes it easy to change designs, and can meet the needs of small-batch decoration. The inventors of this invention have confirmed that, through their experiments, it is possible to freely apply decorative designs to the surface of metal fasteners used in bags, wallets, and other items, even designs that were previously impossible to apply, by printing using the UV printer described above. For example, unique patterns and characters can be freely expressed on the surface of the metal fasteners.

[0007] However, even though it was possible to add freely designed decorations to the above-mentioned metal fittings, it was found that decorations printed with UV ink on the metal surface peeled off easily, and it was difficult to ensure that the UV ink would adhere well enough to withstand use as a fastener. Specifically, after attaching adhesive tape to the surface of the metal fittings and then peeling off the adhesive tape, the UV-printed decoration (decorative part) stuck to the adhesive tape and peeled off. The inventors of this application conducted further studies and, prior to UV printing, focused on a technique used in automobile sheet metal painting to modify the surface to be painted in order to improve paint adhesion, and considered whether this could be used to fix UV printing to the metal fittings mentioned above. Originally, painting large metal materials such as automobile bodies and buildings is primarily for rust prevention and not for the purpose of applying intricate decorations. The inventor of this invention, through his unconventional thinking, focused on a technology that could be used for painting large metal materials like those described above.

[0008] More specifically, the above-mentioned technology used in sheet metal painting involves vaporizing and burning a liquid organometallic substance containing silicon, then blowing the flame onto the surface of a metal sheet to form a film of silicon oxide particles on the surface of the metal sheet, after which painting is performed (Patent Documents 2 and 3). [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2022-39283 [Patent Document 2] Japanese Patent Publication No. 2022-43779 [Patent Document 3] Utility Model Registration No. 3181753 Gazette [Disclosure of the Invention] [Problems that the invention aims to solve]

[0010] Through trial and error by the inventor of this invention, it was found that, while the technology described above is used to modify the surface of large metal materials to ensure paint adhesion, further ingenuity is needed to reliably adhere decorations applied by UV printing to small metal fittings such as bag clasps. Furthermore, in fasteners such as hooks, eyelets, and rivets, which have a pair of male and female parts with protrusions and indentations, and which are fixed to the leather by sandwiching the leather between the two parts and striking them with a tool, the improvement in the adhesion between the silicon dioxide microparticle film and the cured UV ink is insufficient; it is necessary to ensure that the material does not peel off even when struck with a tool. The present invention solves the above problems and makes it possible to provide metal fittings such as bag fasteners with novel decorations, while also providing fittings in which the decorations are less likely to peel off. [Means for solving the problem]

[0011] The present invention provides a metal fitting, such as a bag clasp, having a metal fitting body whose surface is at least made of metal, and a decorative part provided on the surface of the metal fitting body, wherein the decorative part comprises, in order from the metal fitting body side, i.e., the lower layer side, a surface modification layer, a primer layer, a UV printing layer exhibiting decoration, and a transparent topcoat layer, wherein the surface modification layer is a film of silicon dioxide fine particles attached to the surface of the metal fitting body, the UV printing layer is a layer printed with UV ink that hardens when irradiated with ultraviolet light, the primer layer is an adhesive layer that adheres the UV printing layer to the surface modification layer, and the topcoat layer is formed of a glass coating agent. The metal fittings such as clasps on bags mentioned above are fittings attached to leather products such as bags, pouches, wallets, belts, keychains, and watch bands. These metal fittings such as clasps on bags include fasteners for opening and closing parts of bags, wallets, and pouches, fasteners for fishing straps, and fasteners for securing belts and watch bands into loops, as well as fittings attached to leather products solely for decorative purposes. Furthermore, in the present invention, the metal of at least the surface of the fitting is one of aluminum, stainless steel, SS material, or brass, the film of silicon oxide fine particles is a sprayed layer formed by spraying a combustion flame of a silicon-containing organometallic liquid, the primer layer is a layer of adhesive printed with an ultraviolet-curable primer ink that hardens upon irradiation with ultraviolet light, or a layer coated with an adhesive whose components are butyl acetate, methylcyclohexane, and cyclohexane, the glass coat layer is formed of a silicon compound, and the fitting is a metal fastener such as a snap. The fasteners mentioned above include snaps, eyelets, and rivets. Furthermore, the present invention provides a method for decorating the surface of metal fittings, such as bag clasps, which have at least a metallic surface, by UV printing. Prior to the UV printing, a liquid organometallic material containing silicon is vaporized and burned and sprayed onto the surface of the fitting to form a film of silicon oxide particles on the surface of the fitting. After the silicon oxide particle film is formed, a primer is applied to the surface of the fitting. After the UV printing, the surface of the fitting is coated with a glass coating agent as a post-treatment. The metal fittings are fasteners such as snaps. Furthermore, in the present invention, the UV printing uses an inkjet printer equipped with an ink head that ejects UV ink, a mounting table on which the object to be printed is placed, and an ultraviolet irradiation device, wherein the UV ink is cured by irradiation with ultraviolet light, the ultraviolet irradiation device irradiates the photocurable ink ejected onto the object to be printed with ultraviolet light to cure the UV ink, the pre-treated metal fitting is placed on the mounting table as the object to be printed, the UV ink is ejected from the ink head onto the metal fitting on the mounting table to apply the decoration to the surface of the metal fitting, and the ultraviolet light is applied to the surface of the decorated metal fitting. The method involves irradiating the metal fitting with ultraviolet light from an irradiation device, placing the metal fitting on the aforementioned stand, or fitting the metal fitting into a plate-shaped jig having one or more receiving parts into which the pre-treated metal fitting can be fitted, and then placing the jig with the metal fitting into it on the aforementioned stand, using an inkjet printer equipped with a primer ink head that ejects primer ink that hardens when irradiated with ultraviolet light, applying the primer to the surface of the metal fitting by printing prior to the UV printing, and irradiating the printed primer with ultraviolet light from the ultraviolet irradiation device, thereby providing a method for decorating metal fittings. Furthermore, instead of discharging the primer ink from the primer head to print the primer and irradiating the primer with ultraviolet light, the present invention sprays a primer composed of butyl acetate, methyl cyclohexane, and cyclohexane onto the fitting before being placed on the mounting table with dimethyl ether as an aerosol, thereby applying the primer to the surface of the fitting after the formation of the film of the silicon oxide fine particles. The present invention can provide a method for decorating a fitting, which comprises placing the fitting after the primer application on the mounting table and performing the UV printing with an inkjet printer.

Advantages of the Invention

[0012] The present invention can impart a novel decoration to a fitting such as a fastener of a bag and make the decoration difficult to peel off. That is, by using UV printing, it is possible to impart decorations with unprecedented hues and designs to the fasteners of bags. In addition, the decoration by the UV printing applied to the surface of a metal with a small decorative surface and many curved surfaces such as a fastener is firmly fixed, and even if the decorative surface is struck with a tool for attachment to leather, the decoration will not fall off.

Brief Description of the Drawings

[0013] [Figure 1] (A) is a schematic side view showing a hook (the head member of the female member) to which the present invention can be applied, (B) is a schematic side view showing a state in which the hook in (B) is decorated by UV printing, and (C) is an enlarged cross-sectional view of the main part of the hook according to the present invention. [Figure 2] (A) is an exploded perspective view of the female member of the hook to which the present invention can be applied, (B) is an explanatory view showing a schematic end face of a state in which the female member of the hook shown in (A) is attached to leather, and (C) is an exploded perspective view of the male member of the hook that fits with the female member of the hook shown in (A) and (B). [Figure 3] (A) is an exploded perspective view of a rivet to which the present invention can be applied, (B) is an exploded perspective view of a crimp to which the present invention can be applied, (C) is a schematic end face view during the assembly (attachment) of the crimp shown in (B), and (D) is a schematic end face view showing a completed state of the assembly (attachment) of the crimp shown in (C). [Figure 4] (A) is a perspective view showing an example of a UV printer used in the implementation of the present invention, and (B) is a front view showing the state where the cover of the UV printer in (A) is open. [Figure 5] (A) is a perspective view of a jig used to place a hook (female member head member) for UV printing on the UV printer shown in FIG. 4, (B) is a partially cut-away enlarged cross-sectional view showing the state during the process of fitting the hook for UV printing into the receiving portion of the jig in (A), and (C) is a perspective view of the jig shown in (B) after being removed from the UV printer after UV printing has been performed on the hook by the UV printer. [Figure 6] (A) is a plan view of the decorative portion of a hook (female member head member) according to an embodiment of the present invention, (B) is an expanded plan view of the cellophane tape pasted onto and peeled off from the decorative portion of the hook in (A), (C) is a plan view of the caulked decorative portion according to an embodiment of the present invention, (D) is an expanded plan view of the cellophane tape pasted onto and peeled off from the decorative portion of the caulked portion in (C), (E) is a plan view of the decorative portion of a hook according to another embodiment of the present invention, (F) is an expanded plan view of the cellophane tape pasted onto and peeled off from the decorative portion of the hook in (E), (G) is a plan view of the decorative portion of a hook of a comparative example, (H) is a perspective view showing the state of pasting and peeling the cellophane tape onto the decorative portion of the hook in (G), and (I) is a perspective view of the cellophane tape pasted onto and peeled off from the decorative portion of the hook in (H).

Embodiments for Carrying out the Invention

[0014] Embodiments according to the present invention will be described below with reference to the following drawings. Regarding the material of this metal fitting 1 (metal fitting body), brass, aluminum, stainless steel, and SS material are suitable. In this example, the metal fitting 1 is made of brass. The metal fitting 1 may be, in addition to fasteners for bags and wallets, a belt buckle or the like, but it is desirable that for any metal fitting, the maximum width in the front, rear, left, and right directions does not exceed 5 cm, and the maximum height does not exceed 2 cm. In this example, the metal fitting 1 is a metal fastener attached to leather products, that is, leather bags such as handbags and leather wallets. The metal fitting 1, shown in detail in Figure 1, is a snap fastener (a spring snap fastener equipped with a spring 8a, also known as a spring snap fastener), and consists of a pair of separate female parts, i.e., female members 2 (Figure 2(A)(B)), and male parts, i.e., male members 11 (Figure 2(C)).

[0015] The female member 2 described above has a head member 3 and a receiving member 7 formed separately from the head member 3 (Figures 2(A) and 2(B)). The head member 3 comprises a substantially disc-shaped head 4 and a shaft portion 5 that protrudes downward from the center of the lower surface of the head 4 (Figures 1(B) and 2(A) and 2(B)). The upper surface of the head member 3 is equipped with a decorative portion 6 that is decorated by UV printing. As shown in Figure 1(C), the decorative part 6 is composed of a surface modification layer 6a, a primer 6b layer, a UV printing layer 6c, and a top coat layer 6d, in order from the surface side, i.e., the bottom side, of the metal fitting body 1 (the head member 3 of the female member 2).

[0016] The surface modification layer 6a is a film of silicon dioxide fine particles attached to the surface of the metal fitting body 10. The surface modification layer 6a, being a film of silicon dioxide fine particles, increases the frictional resistance of the head surface (upper surface) of the head member 3 of the female member 2 on the metal fitting 1, which is a metal surface, and promotes the adhesion of other layers constituting the decorative part 6 to the metal surface. The silicon dioxide nanoparticle film described above is a sprayed layer formed by spraying a combustion flame of a silicon-containing organometallic liquid onto it. The primer layer 6b is an adhesive layer that adheres the UV printing layer to the surface modification layer 6a. In this example, the primer layer 6b is an adhesive layer printed with a UV-curable primer ink that hardens when exposed to ultraviolet light. The UV printing layer 6c is a layer printed with UV ink that hardens when exposed to ultraviolet light, and is used for designs and patterns. To adorn. The top coat layer 6d is a transparent layer formed from a glass coating agent. Specifically, the top coat layer 6, which is a glass coating, is formed from a silicon compound. As described later, even if the metal fitting 1 is struck with a tool to fix it to the leather product, the top coat layer 6 protects the UV printing layer 6c of the decorative part 6, and together with the primer layer 6b, reliably prevents the UV printing layer 6cT from falling off the metal fitting body 10.

[0017] The receiving member 7 of the female member 2 has a receiving portion 9 on its lower side for fitting the shaft portion 5 of the head member 3 of the female member 2. The receiving member 7 of the female member 2 has a recess 8 on its upper side (Figure 2(A)(B)). The spring 8a, which is a wire, is placed inside the recess 8. The head member 3 of the female member 2 of the hook is attached to the leather k by being integrated with the receiving portion 9 of the female member 2, sandwiching the leather k of the leather product (Figure 2(B)). In detail, a well-known striking base d, which has a recess d1 on its upper surface, is used to receive the head 4 of the head member 3 of the female member 2 which is inverted upside down. The shaft portion 5, which protrudes upward from the head member 3 on the recess d1, is passed through the through hole in the leather k, which has a through hole drilled in it. The tip of the shaft portion 5, which protrudes upward from the leather k through the through hole, is fitted into the receiving portion 9 of the receiving member 7, and by striking it from above with a tool (white arrow in Figure 2(B)), the head member 3 of the female member 2 is made one with the receiving member 7, sandwiching the leather k, and the female member 2 is fixed to the leather.

[0018] The male member 11 described above has a convex member 12 and a sub-receiving member 13 formed separately from the convex member 12 (Figure 2(C)). The convex member 12 comprises a disc-shaped base 14 and a convex portion 15 which is an axis protruding from the center of the lower surface (upper surface in the state shown in Figure 2(C)) of the base 12. The sub-receiving member 13 comprises a disc-shaped sub-base 16 and a sub-receiving portion 17 which penetrates the center of the sub-base 16 vertically and has a cylindrical protrusion around the lower surface (upper surface in the state shown in Figure 2(C)) of the sub-base 16. Although not shown in the diagram, in the above leather product, the protrusion 15 of the male member 11's protrusion 12 is passed through another through hole (sub-through hole) located at a different position from the through hole to which the female member 2 is attached. The tip of the protrusion 15 protruding from the sub-through hole is fitted into the sub-receiving portion 17 of the sub-receiving member 13, and the cylindrical circumference of the sub-receiving portion 17 is crimped, thereby integrating the male member 11's protrusion 12 with the sub-receiving member 13 with the leather in between, and fixing the male member 11 to the leather.

[0019] As described above, by inserting the protrusion 15 of the convex member 12 of the male member 11, which is attached to the leather k, into the recess 8 of the receiving member 7 of the female member 2 of the snap fastener attached to the leather k, against the spring 8a, the protrusions and recesses of the snap fastener are engaged, and the opening of the bag to which the snap fastener is attached can be closed. By removing the protrusion 15 of the convex member 12 of the male member 11 from the recess 8 of the receiving member 7 of the female member 2, against the spring 8a, the engaged protrusions and recesses of the snap fastener are separated, and the opening of the bag can be opened.

[0020] Next, the formation of the decorative part 6 described above will be explained in detail. Regarding the head member 3 (Figure 1(A)) of the female member 2 of the metal fitting 1 (hook) before it is attached to the leather k, The following steps are performed in order: 1) cleaning process, 2) surface modification process, 3) primer application process, 4) printing process, and 5) post-processing process. 1) Cleaning process The cleaning process involves wiping away dirt and oil from the head portion 4 of the head portion 3 of the female component 2, and is performed to improve the adhesion of the decorative portion 6 layer. It is preferable to use a well-known industrial degreasing spray when wiping away the dirt and oil.

[0021] 2) Surface modification process The surface modification process involves vaporizing and burning a silicon-containing organometallic liquid and spraying it onto the surface of the metal fitting 1 (the head 4 of the head member 3 of the female member 2) to form a film of silicon oxide fine particles (surface modification layer 6a) on the surface of the metal fitting 1. Specifically, in the surface modification process, a liquid (liquefied gas) of an organometallic material containing silicon is vaporized and burned, and sprayed onto the surface of the metal fitting 1 to form a film of silicon oxide fine particles on the surface of the metal fitting 1, and a primer is applied to the surface of the metal fitting 1 after the formation of the silicon oxide fine particle film.

[0022] An example of a burner device n suitable for vaporizing and burning a liquid organometallic containing silicon is shown in Fig. 3(E). This burner device n is the same as that shown in Patent Document 3 (Utility Model Registration No. 3181753). Specifically, the burner device n includes a cylinder n50 storing fuel (liquefied gas of organometallic containing silicon), a burner n80 equipped with a hand valve n81 and a torch n82 installed on this burner n80, a fuel passage n60 for feeding the fuel stored in the cylinder n50 to the burner n80, a valve n40 interposed at the connection point between the cylinder n50 and the fuel passage n60, and a valve opening / closing handle n41 for opening and closing the valve n40. The fuel passage n60 has a metal pipe n63 connected to the valve n40, a heat exchanger n64 and a pressure regulator n65 interposed in the pipe n63, and a fuel hose 62 connected to the burner n80. Connection ports n45 of a coupler, which is a pipe joint, and insertion ports n46, which are mating members of the connection ports n45, are provided separately on the pipe n63 and the fuel hose n62. In this burner device n, the liquid fuel fed from the cylinder n50 exchanges heat with the outside air by passing through the heat exchanger n64 to become gaseous fuel. Then, the gaseous fuel is pressure-adjusted by the pressure regulator n65 and fed to the burner n80 via the pipe n63 and the coupler, and is ejected from the torch n82 of the burner n80. In this example, in the burner device n, all the other components except the fuel hose n62, the burner n80, and the torch n82 are fixed at a fixed position in a portable case not shown in the figure.

[0023] As the above burner device n, Flame Bond (registered trademark / product name Flame Bond FB-5) sold by Soft99 Corporation (2-6-5, Tanima, Chuo-ku, Osaka) can be used. As a cartridge of the liquefied gas of organometallic containing silicon used for Flame Bond, it is preferable to adopt "Flame Bond dedicated gas cartridge GC-04S" (product name) sold by Soft99 Corporation, which contains isobutane and silicone as the contents (components) in particular. The liquefied gas described above can be one that has a fuel composition that generates a flame that comes into contact with the metal fitting 1 through combustion, as described in Patent Document 2 (Japanese Patent Publication No. 2022-43779). More specifically, the above fuel composition contains a flammable component, a surface modifier, and a modifier. The flammable component is a flammable compound, and examples include flammable gases such as natural gas, methane gas, ethane gas, propane gas, butane gas, ethylene gas, petroleum gas, and acetylene gas, or liquefied flammable gases. Other examples of flammable components include paraffinic solvents such as n-hexane, n-heptane, n-octane, isooctane, and mineral turpentine; naphthenic solvents such as cyclopentane and cyclohexane; petroleum solvents such as gasoline and kerosene; and alcoholic solvents such as methyl alcohol, ethyl alcohol, and isopropyl alcohol. As the flammable component, flammable gas, particularly butane gas, is preferred.

[0024] The surface modifier described above is selected from the group consisting of silicon-containing organic compounds, titanium-containing organic compounds, and aluminum-containing organic compounds. Examples of silicon-containing compounds include siloxane compounds. Examples of the siloxane compounds mentioned above include dimethylpolysiloxane (e.g., hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, etc.), dihydrotetramethyldisiloxane, hexamethyltrisiloxane, pentamethyltrihydrotrisiloxane, cyclic methylhydrotetrasiloxane, cyclic methylhydropentasiloxane, cyclic dimethyltetrasiloxane, cyclic methyltrifluoropropyltetrasiloxane, cyclic methylphenyltetrasiloxane, cyclic diphenyltetrasiloxane, methylhydropolysiloxane with methyl-sealed ends, phenylhydropolysiloxane with methyl-sealed ends, and methylphenylpolysiloxane. These siloxane compounds can be used individually or in combination of two or more. Dimethylpolysiloxane is preferred as the siloxane compound from the viewpoint of non-flammability, purity, and cost.

[0025] Examples of titanium-containing compounds include alkyl titanium compounds. Examples of alkyl titanium compounds include titanium tetraisopropoxide, titanium tetran-butoxide, titanium butoxide dimer, titanium tetra-2-ethylhexoxide, titanium diisopropoxybis(acetylacetonate), titanium tetraacetylacetonate, titanium di-2-ethylhexoxybis(2-ethyl-3-hydroxyhexoxide), and titanium diisopropoxybis(ethylacetoacetate). These alkyl titanium compounds can be used individually or in combination of two or more. From the viewpoint of non-flammability, purity, and cost, titanium tetraisopropoxide is preferred as the alkyl titanium compound. These titanium-containing compounds can be used individually or in combination of two or more.

[0026] Examples of the above-mentioned aluminum-containing compounds include alkylaluminum compounds. Examples of alkylaluminum compounds include aluminum ethylate, aluminum isopropylate, aluminum diisopropylate monosecondary butyrate, aluminum secondary butyrate, aluminum ethyl acetacetate diisopropylate, aluminum trisethyl acetacetate, aluminum alkyl acetacetate diisopropylate, aluminum bisethyl acetacetate monoacetylacetonate, aluminum trisacetylacetonate, aluminum oxide isopropoxide trimer, aluminum oxide octylate trimer, and aluminum oxide stearate trimer. These alkylaluminum compounds can be used alone or in combination of two or more types.

[0027] Preferably, the surface modifier is a silicon-containing compound or a titanium-containing compound, more preferably a silicon-containing compound, even more preferably a polysiloxane compound, and particularly preferably hexamethyldisiloxane. The surface modifier may be in any state, such as gas, liquid (vapor), or solid (dust). Preferably, the surface modifier is included in the fuel composition in liquid form. Modification aids are organic compounds (excluding the flammable components and surface modifiers mentioned above) that improve the surface modification performance of surface modifiers by promoting the radicalization of surface modifiers and stabilizing them in a radical state.

[0028] 3) Primer application process and 4) Printing process In the primer application process, the primer 6b layer is formed by applying the above-mentioned primer. Specifically, an inkjet printer similar to the one shown in Patent Document 1 (Japanese Patent Publication No. 2022-39283) is used, and in particular, an inkjet printer equipped with a primer ink head m30 that ejects primer ink that hardens when irradiated with ultraviolet light as shown in Figures 4(A) and (B), an ink head m31 that ejects UV ink, a mounting table (table m35) on which the object to be printed (metal fitting 1) is placed, and ultraviolet irradiation devices m41 and m42. As the inkjet printer, Roland DG Corporation (Hamamatsucho Building 10F, 1-18-16 Hamamatsucho, Minato-ku, Tokyo) VersaUV300D, 300, and 200 (product names) can be used. The above-mentioned inkjet printer (hereinafter simply referred to as printer m10) will be described below. The M10 printer prints on the material to be printed. The M10 printer is a flatbed type printer equipped with the M12 enclosure. An internal space m12S is formed in the housing m12. The housing m12 comprises a base member m13, a case m15, a front cover m23, and an operation panel m25.

[0029] The base member m13 comprises a bottom wall m13A, a left side wall m13L, a right side wall m13R, and a support wall m13T. The support wall m13T is supported by the left side wall m13L and the right side wall m13R. The case m15 is attached to the base member m13. An opening m28 is formed in the front of the case m15. The front cover m23 is provided in the case m15 so as to be able to open and close to the opening m28. That is, the front cover m23 is attached to the case m15 so as to be able to rotate around its rear end. By rotating the front cover m23 upward, the internal space m12S and the external space of the housing m12 are connected. The internal space m12S is the space in which printing is performed on the material to be printed by the ink head m31 and the degree of curing of the cured photocurable ink is detected by the contact sensor m50. The front and top of the front cover m23 are provided with windows m23A that allow the interior of the housing m12 to be viewed. Window m23A is made of a transparent acrylic plate. Window m23A is treated to block ultraviolet light so that ultraviolet light from the external space does not reach the internal space m12S.

[0030] The control panel m25 is located on the top surface of the case m15. The control panel m25 allows for operations related to image printing, setting (changing) the intensity of light emitted from the UV irradiation devices m41 and m42, and setting the degree of curing. The control panel m25 includes a display screen m25A that shows printing-related information such as the type of print (e.g., glossiness), resolution, and printing status, as well as input buttons m25B for setting information related to printing and the printed material.

[0031] The printer m10's case m15 contains a guide rail m18, a carriage m20, a primer ink head m30, an ink head m31, the ultraviolet irradiation devices m41 and m42, the contact sensor m50, and a control device m80. The guide rail m18 is located inside the case m15. The guide rail m18 is fixed to the support wall m13T of the base member m13 and extends in the left-right direction, which is the main scanning direction. The ink head m31, the ultraviolet irradiation devices m41 and m42, and the contact sensor 50 are mounted on the carriage m20. The carriage m20 is slidably mounted on the guide rail m18. The carriage m20 moves back and forth along the guide rail m18 by means of a carriage movement mechanism (not shown) equipped with a drive motor. The carriage movement mechanism also causes the guide rail m18 to move back and forth. The carriage movement mechanism described above is controlled by the control device m80. As carriage m20 moves, the ink head m31, ultraviolet irradiation devices m41 and m42, and contact sensor m50 mounted on carriage m20 also move.

[0032] The carriage m20 is equipped with a primer head m30 and multiple ink heads m31. The primer ink head m30 has a nozzle (not shown) that dispenses UV-curable primer ink, which forms the primer layer 6b, onto the workpiece placed on the table m35. The ink heads m31 have nozzles (not shown) that dispense UV-curable ink onto the workpiece placed on the table m35. The primer head m30 and ink heads m31 are each connected to an ink cartridge m34 housed in a case m15 by a flexible ink tube (not shown). The ink cartridge m34 stores the UV-curable primer ink and the UV-curable ink, respectively. The UV-curable inks stored in the M34 ink cartridge are generally composed primarily of well-known acrylic esters.

[0033] The ultraviolet irradiation devices m41 and m42 irradiate the primer ink and ultraviolet-curable ink discharged onto the substrate (metal fitting 1) with ultraviolet light to cure the primer ink and ultraviolet-curable ink. Specifically, as the carriage m20 moves, the primer ink is first discharged sequentially from the nozzle of the primer ink head m30 onto the substrate on the table m35. After the carriage m20 returns to its original position, it starts moving again, and the UV-curable ink is sequentially ejected from the nozzle of the ink head m31 onto the substrate on the table m35 (CYSK color printing). After the carriage m20 returns to its original position once more, it starts moving again, and UV light is sequentially irradiated from UV irradiation devices m41 and m42 onto the substrate (metal fitting 1) coated with primer ink and thermosetting ink. As described above, the operation of printer m10 completes steps 3) primer application and 4) printing, and the formation of the primer layer 6b and the printed layer 6c on the metal fitting 1 (head 4 of head member 3) is completed.

[0034] The control device m80 that controls the printer m10 is a microcomputer. For example, the control device m80 includes an interface (I / F) for receiving print data from external devices such as a host computer, a central processing unit (CPU) that executes instructions for the control program, a ROM (read-only memory) that stores the program executed by the CPU, a RAM (random access memory) used as a working area for expanding the program, and a storage device such as memory that stores the program and various data. The control device m80 may be a computer or the like installed outside the case m15, unlike the example shown.

[0035] Furthermore, when printing the decorative part 6 onto the head member 3 of the female member 2 of the hook shown in Figure 1(A) using the printer m10, it is unstable to place the head member 3 of the female member 2 directly on the table m35. Therefore, the jig g shown in Figure 4 is used to position the head member 3 of the female member 2 on the table m35. The jig g can be made of a non-combustible material such as cardboard or steel. In this example, the jig g is a plate that is roughly rectangular in plan view. The jig g has a receiving part g1 into which the shaft part 5 of the female member 2 can be fitted. The receiving part g1 is a hole with a bottom or a through part that penetrates the jig g, and the inner diameter of the receiving part g1 is the same as or slightly larger than the shaft part 5 of the female member 2 and smaller than the outer diameter of the head member 3 of the female member 2. Therefore, by attaching the shaft part 6 of the head member 3 to the receiving part g1, the head member 3 can be positioned stably with its head 4 facing upwards, and only the head 4 of the head member 3 can be exposed on the upper surface of the jig g. Although the rear head member 3 on which the surface modified layer 6a is formed may be attached to the jig g, in order to prevent the surface modified layer 6a from peeling off due to touching with fingers, the jig g is made of the non-combustible material described above, and the surface modified layer 6a is formed with the head 4 of the head member 3 attached to the jig g. The jig g, on which the head 4 of the head member 3, which has the surface modified layer 6a formed thereon, is placed on the table m35 of the printer m10.

[0036] 5) Post-processing steps The post-processing step involves applying a well-known glass coating agent for outdoor installations to the head 4 of the metal fitting body 10 (head member 3) that has been removed from the printer m10 after the primer application and printing steps are completed, thereby forming a top coat layer 6d. The glass coating agent for outdoor installations is preferably composed of silicon compounds and petroleum-based solvents, and it is preferable to use "H-7 Glass Coating Agent for Outdoor Installations" (product name) sold by Soft99 Corporation.

[0037] (Example of change) The use of the printer m10 as described above made it possible to perform steps 3) primer application and 4) printing in parallel. Alternatively, the printer m10 may be used to form only the UV printing layer 6c on the metal body 10 (the head 4 of the head member 3), that is, the printer m10 may not apply primer ink, and after performing the surface modification step described above, a primer layer 6b may be formed on the head 4 of the head member 3 before it is placed in the printer m (after performing the primer application step outside the printer m10), and then the printer m10 may be used to form only the UV printing layer 6c on the head 4 of the head member 3 (only the printing step may be performed).

[0038] More specifically, the primer layer 6b may be a layer formed by applying an adhesive whose components are butyl acetate, methylcyclohexane, and cyclohexane. In this case, the primer may not be applied by the printer m10 (the primer ink may not be ejected), but rather the primer consisting of butyl acetate, methylcyclohexane, and cyclohexane may be sprayed onto the metal fitting body 10 from a spray can containing a propellant, dimethyl ether. As the spray-type adhesive (adhesive-containing spray can), "Soft99 Printing Undercoat" (product name) sold by Soft99 Corporation can be used.

[0039] In the above example, the metal used to make up the fasteners (hooks) was brass, but the material of the fasteners may also be aluminum, stainless steel, or SS material. Furthermore, in addition to the snap fasteners shown in Figures 1, 2, and 5, the present invention can also be applied to other metal fittings 1 such as the eyelets shown in Figure 3(A) and the rivets shown in Figures 3(B) to (C).

[0040] The eyelet described above is a metal fitting 1 consisting of a pair of an annular female member 2 and an annular male member 11 formed separately from the female member 2. The male member 6 of the eyelet consists of a cylindrical portion 18 that is inserted into the center of the annular female member 2 and a flange-shaped portion 18a formed at one end of the cylindrical portion 18. A decorative portion 6 is provided on the side of the flange-shaped portion 18a opposite to the cylindrical portion 18. Although not shown in the illustration, the cylindrical portion 18 of the male member 6 is passed through a through hole drilled in the leather of the leather product, and the tip of the cylindrical portion 18 exposed from the through hole is inserted into the hollow center of the female member 2. The leather is then sandwiched between the male member 6 and the female seat 2, and the eyelet can be fixed to the leather by striking it with a tool. In the above, the side of the female member 2 opposite to the side facing the male member 6 (flange-shaped portion 18a) can also be used as the decorative part 6. The configuration of the decorative part 6 in the above eyelet and the method of forming the decorative part 6 are the same as those of the hooks shown in Figures 1 and 2. However, since the male member 11 and female member 2 of the eyelet have a stable shape, unlike the head member 3 of the female member 2 of the snap fastener, they can be placed on the table m35 of the printer m10 without using a jig g.

[0041] The crimping described above is a metal fitting 1 consisting of a female member 2 and a male member 11 formed separately from the female member 2. The female member 6 of the crimping consists of a disc-shaped head member 20a and a cylindrical portion 20 that protrudes downward from the center of the lower surface (upper surface in Figure 3(B)) of the head member 20a. The male component 11 of the rivet comprises a disc-shaped base portion 21a and a hollow shaft 21 that protrudes upward from the center of the upper surface of the base portion 21a. The cylindrical portion 20 of the female component 2 is passed through a through hole drilled in the leather of the leather product (not shown), and the shaft 21 of the male component 11 is inserted into the cylindrical portion 20 (Figure 3(C)). The head component 20a of the female component 2 is then driven in from above with a tool, causing the tip of the shaft 21 to be crushed and expanded (Figure 3(D)). As the tip of the shaft 21 is crushed and expanded, the male component 11 cannot be removed from the female component 2, and the rivet can be fixed to the leather. The head component 20a of the rivet has a decorative portion 6 on its upper surface. Alternatively, the rivet may have a decorative portion 6 on the bottom surface of the base portion 21a. The structure of the decorative part 6 in the above-mentioned crimping mechanism and the method of forming the decorative part 6 are the same as those of the hooks shown in Figures 1 and 2.

[0042] As shown in Figure 6(A), by implementing the metal fitting decoration method of the present invention (forming a primer layer by spraying without applying a primer with printer m10), it was possible to form a decorative part 6 on the head 4 of the head member 3 of the female member 2 of a brass snap fastener. It was confirmed that the decorative part 6 did not peel off the head 4 even when cellophane tape t was applied to the head 4 shown in Figure 6(A) and peeled off (Figure 6(B)). Furthermore, as shown in Figure 6(C), by implementing the metal fitting decoration method of the present invention (forming a primer layer by spraying without applying a primer with printer m10), it was possible to form decorative parts 6 on the head member 20a of the female member 2 of a brass crimp and the base part 21a of the male member 11, respectively. It was confirmed that the decorative part 6 did not peel off the head 4 even when cellophane tape t was applied to the head member 20a of the female member 2 and the base part 21a of the male member 11, respectively, as shown in Figure 6(C) (Figure 6(D)). As shown in Figure 6(E), by implementing the metal fitting decoration method of the present invention (applying a primer with printer m10 to form a primer layer), a decorative part 6 was formed on the head 4 of the head member 3 of the female member 2 of the hook. It was confirmed that the decorative part 6 did not peel off the head 4 even when cellophane tape t was applied to the head 4 shown in Figure 6(E) and peeled off (Figure 6(F)). Even when a fingernail was pressed against each of the decorative parts 6 in Figure 6(A),(C), and(E), no damage to the decorative parts 6 was observed. On the other hand, in the brass snap shown in Figure 6(G), where the decorative part was formed using only UV printing, when cellophane tape t was attached to the head 4 shown in Figure 6(A) and peeled off (Figure 6(H)), the decorative part 6 peeled off from the head 4 (Figure 6(I)). As shown in the example in Figure 6 above, the present invention can be said to be able to reliably fix decorations applied by UV printing to metal fittings. [Explanation of Symbols]

[0043] 1 Metal fittings 2 Female component 3 Head member 4 head 5. Shaft section 6. Decorative parts 6a Surface modified layer 6b Primer layer 6c UV printing layer 6D top coat layer 7 Receiving member 8 recesses 8a Spring 9 Receiving section 10 Metal fittings 11 Male member 12 Convex member 13 Sub-receiving member 14 Base 15 Convex part 16 Sub-substrates 17 Sub-receiving section g jig g1 (receiving part of jig g)

Claims

1. A metal fitting such as a bag clasp, comprising a metal body whose surface is at least made of metal, and a decorative part provided on the surface of the metal body, The decorative part comprises, in order from the metal fitting body side, i.e., the lower layer side, a surface modification layer, a primer layer, a UV printing layer exhibiting decoration, and a transparent topcoat layer. The surface modification layer is a film of silicon dioxide fine particles attached to the surface of the metal fitting body. The aforementioned UV printed layer is a layer printed with UV ink that hardens upon irradiation with ultraviolet light. The primer layer is an adhesive layer that adheres the UV printing layer to the surface modification layer. The metal fitting is characterized in that the top coat layer is formed of a glass coating agent.

2. The metal of at least the surface of the aforementioned fitting is one of aluminum, stainless steel, SS material, or brass. The film of silicon dioxide fine particles is a sprayed layer formed by spraying a combustion flame of a silicon-containing organometallic liquid onto it. The primer layer is either a layer of adhesive printed with an ultraviolet-curable primer ink that hardens upon irradiation with ultraviolet light, or a layer coated with an adhesive whose components are butyl acetate, methylcyclohexane, and cyclohexane. The aforementioned glass coating layer is formed from a silicon compound. The fitting is a metal fastener such as a snap, as described in claim 1.

3. This involves applying UV printing to the surface of metal fittings, such as bag clasps, which have at least a metal surface. As a pretreatment prior to the UV printing, a liquid organometallic material containing silicon is vaporized and burned and sprayed onto the surface of the metal fitting to form a film of silicon oxide fine particles on the surface of the metal fitting, and a primer is applied to the surface of the metal fitting after the formation of the silicon oxide fine particle film. The surface of the metal fitting after UV printing is coated with a glass coating agent as a post-treatment. A method for decorating metal fittings, characterized in that the fittings are fasteners such as snaps.

4. The aforementioned UV printing uses an inkjet printer equipped with an ink head that ejects UV ink, a mounting table on which the material to be printed is placed, and an ultraviolet irradiation device. The UV ink is cured by irradiation with ultraviolet light, and the ultraviolet irradiation device irradiates the photocurable ink dispensed onto the substrate with ultraviolet light to cure the UV ink. The pre-treated metal fitting is placed on the aforementioned stand as the material to be printed, UV ink is ejected from the ink head onto the metal fitting on the aforementioned stand to apply the decoration to the surface of the metal fitting, and ultraviolet light is irradiated onto the decorated surface of the metal fitting from the ultraviolet irradiation device. The metal fitting is placed on the aforementioned stand, or the metal fitting is fitted into a plate-shaped jig having one or more receiving parts into which the pre-processed metal fitting can be fitted, and the jig with the metal fitting fitted is placed on the aforementioned stand. The method for decorating metal fittings according to claim 3, characterized in that the inkjet printer used is equipped with a primer ink head that ejects primer ink that hardens when exposed to ultraviolet light, and prior to the UV printing, the primer is applied to the surface of the metal fitting by printing, and the printed primer is exposed to ultraviolet light using the ultraviolet irradiation device.

5. The method for decorating metal fittings according to claim 4, characterized in that, instead of ejecting the primer ink from the primer head to print the primer and irradiating the primer with ultraviolet light, a primer consisting of butyl acetate, methylcyclohexane, and cyclohexane is sprayed onto the metal fitting before it is placed on the stand described above using dimethyl ether as a propellant, thereby applying the primer to the surface of the metal fitting after the formation of a film of silicon dioxide fine particles, and the metal fitting after the primer has been applied is placed on the stand described above and the UV printing is performed with an inkjet printer.

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