Resin liquid and method for forming a shaped object

Abstract

Provided are: a resinous liquid suitable for producing shaped objects including three-dimensional metallic structures; and a method for forming a shaped object. The resinous liquid comprises a radical photocurable resin, a heat-curable resin, and an acid catalyst, wherein the heat-curable resin contains a melamine-based crosslinking agent or a benzoguanamine-based crosslinking agent and the heat-curable resin is contained in an amount of 3-60 wt%.

Description

Technical Field

[0001] The present disclosure relates to a resin liquid and a method for forming a molded article.

Background Art

[0002] Japanese Patent Application Laid-Open No. 2019-123909 (Patent Document 1) describes an electroless plating substrate structure using a primer layer, a structure of an electric circuit, and a pretreatment method and an electroless plating method for electroless plating. This electroless plating substrate structure is formed by laminating an insulating substrate, a primer layer, and a catalytic metal layer. In this electroless plating substrate structure, the catalytic metal layer is composed of monodisperse metal nanoparticles with a particle size of 2 to 100 nm, the primer layer has an amino group, the catalytic metal layer is formed on the primer layer by an aqueous solution in which a monodisperse metal nanoparticle group is uniformly dispersed, and the catalytic metal layer and the primer layer are joined via the amino group on the primer layer.

[0003] Japanese Patent Application Laid-Open No. 2012-006234 (Patent Document 2) describes a three-dimensional polymer-metal composite micro-structure and a method for manufacturing the same. In this manufacturing method, a polymer structure is formed by a stereolithography method using a photocurable resin having a reactive group X, and this is immersed in a liquid of metal-containing nanoparticles having a reactive group X' that binds to the reactive group X, and a metal-containing layer such as gold is formed on the polymer structure by the binding of the reactive group X and the reactive group X' to manufacture a polymer-metal composite structure having a three-dimensional structure. An example of the reactive group X is an amino group. The amino group is protected so as to be stable during stereolithography, but is made to generate an active primary amine by contact with water. Patent Document 2 further discloses a method including a step of forming a fine first member having an arbitrary three-dimensional structure by a stereolithography method and a step of forming a fine second member having an arbitrary three-dimensional structure and connected to the first member, and forming a metal-containing layer on only one of the first member or the second member to constitute a fine polymer structure that is an integrally molded product including the first member and the second member. In this case, it is shown that the first member and the second member have different reactive groups.

[0004] Japanese Patent Application Laid-Open No. 2017-218604 (Patent Document 3) describes a method for forming a plating film on a stereolithography product. This method for forming a plating film on a stereolithography product includes a first step of preparing a three-dimensional stereolithography product produced by curing and laminating an epoxy resin layer by layer by stereolithography, and a second step of surface finishing the surface of the stereolithography product by mechanical treatment using an abrasive of #800 to #2000 for polishing treatment, grinding treatment, blasting treatment, or a combination thereof so that the arithmetic mean roughness Ra of the surface is 0.141 μm or more and preferably 0.458 μm or less, and a third step of forming a plating film by performing electroless nickel plating on the surface of the stereolithography product without performing an etching step. In the third step, a sensitizing step of forming a coating film of a tin compound on the surface of the stereolithography product using a sol solution of tin and an activating step of adsorbing a plating catalyst made of palladium on the surface of the stereolithography product using a solution containing palladium ions are performed, and then electroless nickel plating is performed on the surface of the stereolithography product.

[0005] JP-A-2021-006405 (Patent Document 4) describes a method for manufacturing a three-dimensional object from a material having various curing mechanisms. This three-dimensional object manufacturing method includes a step of preparing a carrier and an optically transparent member having a build surface, a step of filling a build region with a polymerizable liquid, the polymerizable liquid including a mixture of a first component of a photopolymerizable liquid and a second component having a different solidifying property from the first component, a step of irradiating the build region with light through the optically transparent member to form a scaffold of a solid polymer from the first component, and moving the carrier in a direction away from the build surface to form a three-dimensional intermediate having the same shape as the three-dimensional object or a shape to be imparted to the three-dimensional object, the three-dimensional intermediate containing the second component carried within the scaffold in an uncured form and / or an unhardened form, and a step of solidifying and / or curing the second component within the three-dimensional intermediate to form a three-dimensional object simultaneously with or subsequent to the irradiation step. The second component includes, for example, a precursor of polyurethane, polyurea, or a copolymer thereof, a silicone resin, or natural rubber, and the solidifying and / or curing step is carried out by heating or microwave irradiation.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0007] As described in Patent Document 1, there is a need to construct a metal structure such as an electric circuit or a shaped object including such a structure using a plating method. In recent years, in particular, there is a need to construct a shaped object including a three-dimensional metal structure. A method for manufacturing a structure or a shaped object including a metal as described in Patent Document 2 requires forming a three-dimensional structure using two or more photocurable resins having different reactive groups separately and then forming a metal-containing layer. Since the process is complicated, it is not sufficiently suitable for constructing a shaped object including a three-dimensional metal structure. Similarly, the plating film formation method for a stereolithography product as described in Patent Document 3 is not sufficiently suitable for constructing a shaped object including a three-dimensional metal structure because an appropriate plating film cannot be formed at locations that cannot be polished. Thus, there is room for improvement in the resin liquid and the shaped object formation method suitable for manufacturing applications of a shaped object including a three-dimensional metal structure. For this reason, it is desired to provide a resin liquid and a shaped object formation method suitable for manufacturing a shaped object including a three-dimensional metal structure.

[0008] The present disclosure has been made in view of such circumstances, and an object thereof is to provide a resin liquid and a shaped object formation method suitable for manufacturing a shaped object including a three-dimensional metal structure.

Means for Solving the Problems

[0009] The resin liquid according to the present disclosure for achieving the above object includes a photo-radical curable resin, a thermosetting resin, and an acid catalyst, wherein the thermosetting resin includes a melamine-based crosslinking agent or a benzoguanamine-based crosslinking agent, and contains 3% by weight or more and 60% by weight or less of the thermosetting resin.

[0010] The shaped object formation method according to the present disclosure for achieving the above object includes a shaping step of shaping using a resin liquid including a photo-radical curable resin, a thermosetting resin, and an acid catalyst, wherein the thermosetting resin includes a melamine-based crosslinking agent or a benzoguanamine-based crosslinking agent, and further contains 3% by weight or more and 60% by weight or less of the thermosetting resin to obtain a first shaped object, A finishing photocuring step of irradiating the first shaped article with light having a wavelength of 300 nm or more to cause photocuring to obtain a second shaped article; A thermosetting step of heating the second shaped article to 60° C. or higher and 280° C. or lower to cause thermosetting to obtain a third shaped article, and includes.

Advantages of the Invention

[0011] A resin liquid and a shaped article forming method suitable for manufacturing a shaped article including a three-dimensional structure of a metal can be provided.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

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Figure 7

Modes for Carrying Out the Invention

[0013] The resin liquid and the shaped article forming method according to the embodiment of the present disclosure will be described.

[0014] The resin liquid according to this embodiment includes a photo-radical curable resin, a thermosetting resin, and an acid catalyst. This resin liquid includes a melamine-based crosslinking agent or a benzoguanamine-based crosslinking agent as the thermosetting resin. This resin liquid contains 3% by weight or more and 60% by weight or less of the thermosetting resin.

[0015] The method for forming a shaped article according to this embodiment includes a shaping step of shaping using the resin liquid according to this embodiment to obtain a first shaped article, a finishing photocuring step of irradiating the first shaped article with light having a wavelength of 300 nm or more to photocure it to obtain a second shaped article, and a thermosetting step of heating the second shaped article to 60°C or more and 280°C or less to thermoset it to obtain a third shaped article.

[0016] According to the resin liquid and the method for forming a shaped article according to this embodiment, it is possible to provide a resin liquid and a method for forming a shaped article suitable for manufacturing a shaped article including a three-dimensional structure of metal. That is, the first shaped article shaped using the resin liquid may not have sufficient hardness to maintain a three-dimensional structure for a long period or to be handled without breaking the shape. However, since the resin liquid contains a photo-radical curable resin, by the photocuring step, it becomes a second shaped article having sufficient hardness to maintain a three-dimensional structure. Further, since the resin liquid contains a thermosetting resin and an acid catalyst, by the thermosetting step, the second shaped article is completely cured and becomes a third shaped article having an amino group on the surface of the shaped article for supporting a catalyst for electroless plating. That is, by using the resin liquid according to this embodiment and subjecting it to the method for forming a shaped article according to this embodiment, it is possible to obtain a third shaped article that is a base material suitable for manufacturing a shaped article including a three-dimensional structure of metal.

[0017] Hereinafter, the resin liquid and the method for forming a shaped article will be described in detail.

[0018] The resin liquid according to this embodiment includes a photo-radical curable resin, a thermosetting resin, and an acid catalyst, and may further include a filler, a pigment, and other additives.

[0019] The filler, the pigment, and other additives can be used without particular limitation as long as they do not inhibit photo-radical curing and thermosetting to the extent of impairing the object of this embodiment, and do not deactivate the amino group of the thermosetting resin to the extent of impairing the object of this embodiment.

[0020] The photo-radical curable resin is a material that constructs a shaped article serving as a support for retaining a three-dimensional structure of a metal by a curing reaction. In the present embodiment, the concept of the photo-radical curable resin includes those having a relatively small molecular weight as a resin, specifically, prepolymers or monomers that can become photo-radical curable resins. The weight average molecular weight is preferably 150 or more and 20000 or less.

[0021] The photo-radical curable resin includes at least one selected from the group consisting of urethane acrylate, epoxy acrylate, acrylic acrylate, polyester acrylate, and acrylate monomer.

[0022] The photo-radical curable resin preferably contains a photoinitiator. As the photoinitiator, for example, alkylphenone-based photoinitiators, acylphosphine oxide-based photoinitiators, oxime ester-based photoinitiators, thioxanthone-based, intramolecular hydrogen abstraction-type photoinitiators, etc. can be used.

[0023] The thermosetting resin may contain an alkylated amino resin, specifically, a melamine-based crosslinking agent or a benzoguanamine-based crosslinking agent.

[0024] The melamine-based crosslinking agent includes methylol melamine or a methylol melamine derivative. As the melamine-based crosslinking agent, melamine, a methylol melamine derivative obtained by condensing melamine and formaldehyde, a compound obtained by reacting methylol melamine with a lower alcohol to partially or completely etherify it, or a mixture thereof can be used. Examples of the lower alcohol include aliphatic alcohols having 1 to 4 carbon atoms. Also, the melamine-based crosslinking agent may be any condensate composed of a monomer or a multimer of dimer or higher, or a mixture thereof. If it is a monomer, hexamethoxymethyl melamine is preferably used. Condensates composed of multimers specifically include imino group-type methylated melamine resins, methylol group-type melamine resins, methylol group-type methylated melamine resins, fully alkylated methylated melamine resins, etc.

[0025] As the benzoguanamine-based crosslinking agent, methylolbenzoguanamine or a methylolbenzoguanamine derivative is included. As the benzoguanamine-based crosslinking agent, benzoguanamine, a methylolated benzoguanamine derivative obtained by condensing benzoguanamine and formaldehyde, a compound obtained by reacting methylolbenzoguanamine with a lower alcohol to partially or completely etherify it, or a mixture thereof can be used. Examples of the lower alcohol include aliphatic alcohols having 1 to 4 carbon atoms. Further, the benzoguanamine-based crosslinking agent may be any of a condensate composed of a monomer or a multimer of dimer or higher, or a mixture thereof. If it is a monomer, tetramethoxymethylbenzoguanamine is preferably used. Specific examples of the condensate composed of a multimer include butylated benzoguanamine resin, methylolbenzoguanamine resin, and the like.

[0026] The benzoguanamine-based crosslinking agent may be used together with a melamine-based crosslinking agent.

[0027] As the acid catalyst, a sulfonic acid-based acid catalyst or a phosphoric acid-based catalyst can be used. For example, a dinonylnaphthalenedisulfonic acid catalyst, a dinonylnaphthalenesulfonic acid catalyst, p-toluenesulfonic acid, or a blocked acid catalyst thereof and a blocked acid catalyst of phosphoric acid can be used.

[0028] As described above, the resin liquid according to this embodiment contains a photo-radical curable resin. Thereby, the second molded article can be cured by a photo-curing step.

[0029] The resin liquid according to this embodiment contains 40% or more and 97% or less, preferably 50% or more and 95% or less of the photo-radical curable resin in terms of mass ratio excluding the solvent. Thereby, the second molded article has a sufficient hardness to maintain a three-dimensional structure by the photo-curing step.

[0030] Since the resin liquid according to this embodiment contains a thermosetting resin containing a melamine-based crosslinking agent or a benzoguanamine-based crosslinking agent and an acid catalyst, through the thermosetting process, the second shaped article is completely cured and becomes a third shaped article having amino groups on its shaped article surface for carrying a catalyst for electroless plating.

[0031] The resin liquid according to this embodiment contains 3% or more and 60% or less, preferably 5% or more and 50% or less of the thermosetting resin in terms of mass ratio excluding the solvent. Thereby, the third shaped article has appropriate strength as a three-dimensional structure of metal through the thermosetting process.

[0032] The resin liquid according to this embodiment may contain a solvent as needed for purposes such as viscosity adjustment.

[0033] The shaped article forming method according to this embodiment includes, as described above, a shaping process for obtaining a first shaped article, a finishing photocuring process for obtaining a second shaped article from the first shaped article, and a thermosetting process for obtaining a third shaped article from the second shaped article.

[0034] The shaping process is a process of obtaining a first shaped article having a shape corresponding to a shaped article including a three-dimensional structure of metal from the resin liquid according to this embodiment.

[0035] The shaping process can be performed by a so-called 3D printer. As methods of 3D printers, for example, the SLA (Stereolithography Apparatus) method of irradiating the resin liquid with light such as dot-shaped ultraviolet light and building a three-dimensional shape by solidifying and stacking the resin little by little from a base, the DPL (Digital Light Projector) method of irradiating the resin liquid with light such as planar ultraviolet light and building a three-dimensional shape by solidifying and stacking the resin from a base, and the MJ (Material Jetting) method (also called the inkjet method) of ejecting the resin liquid from a plurality of nozzles and building a three-dimensional shape by irradiating with light such as ultraviolet light and stacking while curing can be adopted.

[0036] The first shaped object does not necessarily have to be hard enough to maintain a three-dimensional structure for a long time or to be handled without breaking its shape, as long as it has a strength that allows it to be subjected to a photocuring process.

[0037] In the shaping process, the wavelength of the light used to photocure the resin liquid is ultraviolet light of 300 nm or more and 450 nm or less, preferably 350 nm or more and 410 nm or less. By photocuring the resin liquid using light with a wavelength of 300 nm or more, it is possible to suppress the deactivation of amino groups for supporting a catalyst for electroless plating.

[0038] The first shaped object is finish-cured by a finish photocuring process to become a second shaped object having a hardness sufficient to maintain a three-dimensional structure for a long time or to be handled without breaking its shape.

[0039] In the finish photocuring process, ultraviolet light of 300 nm or more and 450 nm or less, preferably 350 nm or more and 410 nm or less, is irradiated onto the first shaped object. Thereby, while curing the first shaped object, it is possible to suppress the deactivation of amino groups for supporting a catalyst for electroless plating.

[0040] The second shaped object is heat-cured by a heat-curing process to be completely cured, and becomes a third shaped object having amino groups for supporting a catalyst for electroless plating on the surface of the shaped object. In the heat-curing process, the second shaped object is heat-cured by heating to 60°C or more and 280°C or less. If the heating temperature in the heat-curing process is too low, the time required for heat-curing may become too long. If it is too high, any of the components of the third shaped object may be altered or deteriorated. If the time required for heat-curing may be long, a heating temperature of 60°C or less may be adopted. Also, if any of the components of the third shaped object is not altered or deteriorated, a heating temperature of 280°C or more may be adopted. In many cases, a heating temperature of 80°C or more and 150°C or less is suitable.

[0041] The third shaped article is then subjected to a catalyst loading step of forming a catalyst loading region on its surface that supports metal nanoparticles. The catalyst loading region can be easily subjected to an electroless plating process for electroless plating. As will be described later, the third shaped article serves as a base material suitable for manufacturing a shaped article including a three-dimensional structure of metal.

[0042] In the catalyst loading step, metal nanoparticles are adsorbed and supported on the amino groups present on the surface of the third shaped article. Therefore, before the catalyst loading step, by forming a region where the amino groups on the surface of the third shaped article are deactivated and a region where the amino groups are not deactivated and are retained, it is possible to achieve the loading of metal nanoparticles only on the region where the amino groups are not deactivated and are retained in the catalyst loading step. That is, it is possible to achieve electroless plating only on the region where the amino groups are not deactivated and are retained.

[0043] As an example of a step for realizing a method of forming a region where the amino groups on the surface of the third shaped article are deactivated and a region where the amino groups are not deactivated and are retained, a pattern forming step is mentioned, in which a part of the surface of the third shaped article is irradiated with light having a wavelength of less than 300 nm (deep ultraviolet light) to form an irradiated region irradiated with light having a wavelength of less than 300 nm and a non-irradiated region not irradiated with light having a wavelength of less than 300 nm.

[0044] In the pattern forming step, by irradiating a part of the surface of the third shaped article with light having a wavelength of less than 300 nm (that is, performing partial irradiation with light having a wavelength of less than 300 nm), a region where the amino groups on the surface of the third shaped article are deactivated can be formed. Note that on the surface of the third shaped article, the non-irradiated region becomes a region where the amino groups are not deactivated and are retained.

[0045] By forming a region where the amino groups are deactivated and a region where the amino groups are not deactivated and are retained, as in the pattern forming step, it is possible to depict the shape of the plated portion, that is, the three-dimensional structure of metal, in the plating step. That is, by the pattern forming step, the catalyst loading step, and the plating step, a three-dimensional structure of metal can be constructed using the third shaped article as a base material.

[0046] In the pattern formation process, for partial irradiation with light having a wavelength of less than 300 nm, a photomask such as a quartz mask or a metal mask may be used, or partial irradiation with a deep ultraviolet laser may be performed.

[0047] The pretreatment solution for electroless plating used in the catalyst support process is preferably a colloidal solution containing metal nanoparticles that serve as a catalyst for reduction-type electroless plating. The pretreatment solution for electroless plating is preferably a pretreatment solution for electroless plating composed of metal nanoparticles of Group IB or VIIIB of the periodic table, sugar alcohol, and water.

[0048] The pretreatment solution for electroless plating preferably has a pH of 6.5 or more and 8.0 or less, and a zeta potential of -50 mV or more and -80 mV or less. In the pretreatment solution for electroless plating, the metal nanoparticles preferably have an average particle size of 10 nm or more and 40 nm or less, and a metal concentration of 50 mg / L or more and 200 mg / L or less. Also, in the pretreatment solution for electroless plating, the sugar alcohol concentration is preferably 0.05 g / L or more and 1.0 g / L or less.

[0049] The metal nanoparticles are nanoparticles of elements of Group IB or VIIIB of the periodic table. Specifically, they are gold (Au), silver (Ag), copper (Cu), platinum (Pt), palladium (Pd), rhodium (Rh), iridium (Ir), ruthenium (Ru), nickel (Ni), cobalt (Co), and iron (Fe). These metals can be dispersed in the liquid in a stable colloidal state by sugar alcohol. In particular, the metal nanoparticles are preferably colloidal nanoparticles of gold (Au), platinum (Pt), or palladium (Pd).

[0050] The sugar alcohol is preferably at least one or more selected from the group consisting of tritol, tetritol, pentitol, hexitol, heptitol, octitol, inositol, quercitol, and pentaerythritol.

[0051] Also, the preferred combinations are as follows. When the colloidal nanoparticles are any of platinum (Pt) nanoparticles, palladium (Pd) nanoparticles, or gold (Au) nanoparticles, the sugar alcohol is preferably at least one or more of glycerin, erythritol, xylitol, mannitol, inositol, or pentaerythritol.

[0052] In the catalyst-supporting step, the third shaped article may be brought into contact with the electroless plating pretreatment liquid, for example, by immersing the third shaped article in the electroless plating pretreatment liquid. As a result, metal nanoparticles are adsorbed and supported in the region where the amino groups are not deactivated and are preserved, that is, the non-irradiated region.

[0053] In the plating step, the third shaped article with metal nanoparticles adsorbed on its surface is immersed in a reducing electroless plating solution. As a result, the metal nanoparticles serve as a catalyst for the electroless plating reaction, and the electroless plating reaction proceeds to form a metal film in the non-irradiated region. In this way, a shaped article including a three-dimensional structure of metal formed along the surface shape of the third shaped article can be constructed.

Examples

[0054] Hereinafter, the resin liquid and the shaped article forming method according to this embodiment will be described by way of examples. In the following description, when simply described as “%”, it means “% by weight”.

[0055] (Example 1) A resin solution for forming a shaped article was prepared by mixing 90% of a ready-made photo-radical curable photocurable resin solution (product name: Clear Resin, manufactured by formlabs, containing 15 - 25% methacrylate monomer, 55 - 75% urethane acrylate, and 0.9% acylphosphine oxide-based photoinitiator), 9% of a methylol melamine crosslinking agent (product name: CYMEL303LF, manufactured by Allnex, containing 99% or more of alkylated melamine as the main component), and 1% of a sulfonic acid-based acid catalyst (product name: CYCAT4040, manufactured by Allnex, containing 40% p-toluenesulfonic acid and 54% isopropanol as the main components). In this resin solution, the photo-radical curable photocurable resin accounts for 89%, the thermosetting resin accounts for 10%, and the acid catalyst accounts for 1%.

[0056] This resin solution was put into an SLA-based stereolithography 3D printer (product name: Form2, manufactured by formlabs) for three-dimensional shaping to obtain a cubic lattice-shaped first shaped article having six lattice-shaped surfaces. The light for photocuring used during three-dimensional shaping was ultraviolet light and blue-violet light with a central wavelength of 405 nm and did not contain light with a wavelength less than 300 nm.

[0057] After washing the first shaped article with ethanol, it was irradiated with light having a central wavelength of 405 nm (however, it did not contain light with a wavelength less than 300 nm) for secondary curing to obtain a second shaped article.

[0058] The second shaped article was charged into an oven in the atmosphere with an internal ambient temperature of 100 °C and heated. The heating time (holding time in the oven) was set to 10 minutes. Thereby, the second shaped article was thermally cured to obtain a third shaped article.

[0059] Next, the third shaped article was immersed in a colloidal solution of gold nanoparticles catalyst for electroless plating (product name: Seed Cat CAT-Au10, manufactured by EEJA) as a pretreatment solution for electroless plating to perform pretreatment for reduction-type electroless plating. The temperature of the pretreatment solution for electroless plating during pretreatment was set to 25 °C. The immersion time of the third shaped article in the pretreatment solution for electroless plating during pretreatment was set to 15 minutes.

[0060] By this pretreatment, gold nanoparticle catalysts with a particle size of about 20 nm were uniformly adsorbed and supported on the surface of the third molded article (see Fig. 1).

[0061] Next, the third molded article after pretreatment was immersed in a reducing electroless gold plating solution (product name: AC FAB Au - ACG3000WX, manufactured by EEJA) to perform a reducing electroless plating process. The temperature of the electroless gold plating solution during the plating process was set at 65°C. The immersion time of the third molded article in the electroless gold plating solution during the plating process was set at 20 minutes.

[0062] By this electroless gold plating, a gold film with a thickness of 200 nm, that is, a three - dimensional structure of metal in the shape along the surface of the third molded article (see Fig. 2) was obtained. In Fig. 2, the lattice - like cube shown as the structure 11 is the metal structure formed on the surface of the third molded article according to Example 1. In Fig. 2, a photograph of the state where the structure 11 is held by the base part (sub - material) during three - dimensional molding is shown.

[0063] (Example 2) Example 2 is different from Example 1 in that, instead of the methylol melamine cross - linking agent, a methylol / n - butyrol benzoguanamine cross - linking agent (product name: BX - 4000, manufactured by Nippon Carbide Industries Co., Ltd., containing 99% or more of methylol / n - butyrol benzoguanamine as the main component) was used, and the rest was the same. Similar to Example 1, a three - dimensional structure of metal in the shape along the surface of the third molded article was obtained by electroless gold plating.

[0064] (Example 3) Example 3 is different from Example 1. Instead of using an existing radical-curable photocurable resin solution, as the radical-curable photocurable resin solution, 89% of a bifunctional acrylate monomer (product name: IRR 214-K, manufactured by Daicel Ornex, containing 99% of tricyclodecane dimethanol diacrylate as the main component) and 1% of an acylphosphine oxide-based photopolymerization initiator (product name: Omnirad 819, manufactured by IGM Resins B.V., containing 99% of 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide as the main component) were mixed. A resin solution was used. Furthermore, the acid catalyst (product name: CYCAT4040) was replaced with an acid catalyst (product name: NACURE X49-110, manufactured by Kusumoto Chemicals, containing 25% of dinonylnaphthalene disulfonate and 75% of a mixed solvent of isopropanol and isobutanol as the main components). A resin solution was prepared in the same manner as in Example 1, except for this replacement. In this resin solution, the solid content is 90% for the radical-curable photocurable resin solution and 10% for the thermosetting resin.

[0065] This resin solution was put into an SLA-type stereolithography 3D printer (product name: Form2, manufactured by formlabs) for three-dimensional modeling to obtain a first modeled object in the shape of a thick disk. The light for photocuring used during three-dimensional modeling is ultraviolet light and violet light with a central wavelength of 405 nm and does not contain light with a wavelength of less than 300 nm.

[0066] Next, deep ultraviolet light with a central wavelength of 254 nm (product name of the light source: Deep-UV lamp UXM-5001MD, manufactured by Ushio Electric) was irradiated onto the surface of the third modeled object through a quartz photomask to form an irradiated area and a non-irradiated area. The irradiation dose is 1000 mJ / cm 2 (However, the value measured at a central wavelength of 254 nm).

[0067] The third modeled object after forming the irradiated area and the non-irradiated area was pretreated with a pretreatment solution for electroless plating in the same manner as in Example 1.

[0068] Next, the third shaped object after pretreatment was immersed in a reducing electroless gold plating solution (product name: AC FAB Au-ACG3000WX, manufactured by EEJA) to perform reducing electroless plating treatment. The temperature of the electroless gold plating solution during the plating treatment was set at 65°C. The immersion time of the third shaped object in the electroless gold plating solution during the plating treatment was set at 10 minutes.

[0069] By this electroless gold plating, a gold film with a film thickness of 100 nm, that is, a structure in the shape of a metal wiring pattern along the surface of the third shaped object (see Fig. 3), could be obtained on a part of the surface of the disk-shaped third shaped object. In Fig. 3, the linear patterns of the metal shown as structures 31, 32, 33, 34, and 35 are the metal structures according to Example 3 formed on the third shaped object.

[0070] (Example 4) In Example 4, the same commercially available photo radical curable photocurable resin liquid as in Example 1 was used. Different from Example 1, a first shaped object in a rectangular parallelepiped shape with a helical (coil-shaped) tunnel space (flow path) formed inside was obtained in the same manner as in Example 1 by shaping with an SLA method 3D printer.

[0071] This first shaped object was used to obtain a second shaped object in the same manner as in Example 1, and further, a third shaped object was obtained from this second shaped object in the same manner as in Example 1.

[0072] Next, deep ultraviolet light with a central wavelength of 254 nm (product name of the light source: Deep-UV lamp UXM-5001MD, manufactured by USHIO INC.) was irradiated onto the surface of the third shaped object. The irradiation dose was 1000 mJ / cm 2 (however, the value measured at a central wavelength of 254 nm). Since the third shaped object does not transmit deep ultraviolet light, the inner surface of the helical tunnel space in the third shaped object becomes a non-irradiated region, and the other surfaces of the third shaped object become irradiated regions.

[0073] After forming the irradiated region and the non-irradiated region, the third shaped article was pretreated with a pretreatment solution for electroless plating in the same manner as in Example 1, and then an electroless plating treatment was further performed. As a result, a gold film with a thickness of 200 nm was formed only on the inner surface of the helical tunnel space of the third shaped article, that is, a three-dimensional structure of a tubular and helical metal having a shape along the inner surface of the helical tunnel space of the third shaped article (see Fig. 4) could be obtained. In Fig. 4, the tubular and helical structure 41 formed in the helical tunnel space 40 is the metal structure according to Example 4 formed inside the third shaped article.

[0074] (Example 5) Unlike Example 1, in Example 5, as the photo radical curable resin liquid, a resin liquid in which 89% of a bifunctional acrylate monomer (product name: HDDA, manufactured by Daicel Ornex, containing 99% of 1,6-hexanediol diacrylate as the main component) and 1% of an acylphosphine oxide-based photoinitiator (product name: Omnirad 819, manufactured by IGM Resins B.V.) were mixed was used, and the resin liquid was prepared in the same manner as in Example 1 for the rest. Hereinafter, this resin liquid is referred to as the first liquid.

[0075] In Example 5, further, as the photo radical curable resin liquid, a resin liquid in which 99% of a bifunctional acrylate monomer (product name: HDDA, manufactured by Daicel Ornex) and 1% of an acylphosphine oxide-based photoinitiator (product name: Omnirad 819, manufactured by IGM Resins B.V.) were mixed was prepared as the second liquid.

[0076] The first liquid and the second liquid were put into a printer (product name: LaboJet, manufactured by Microjet) using the MJ method (inkjet method), and three-dimensionally shaped to obtain a disk-shaped first shaped object similar to that of Example 3. In Example 5, the first liquid and the second liquid were separately applied, and the portion where the metal wiring pattern was to be formed in the first shaped object was constructed with the first liquid. In the three-dimensional shaping of the first shaped object, each time two-dimensional drawing was performed with the first liquid and the second liquid, ultraviolet light with a central wavelength of 340 nm using an LED as a light source was irradiated for photocuring, and by repeating this, the three-dimensional structure of the first shaped object was constructed.

[0077] After the first shaped object was washed with ethanol, it was irradiated with ultraviolet light having a central wavelength of 340 nm (however, light having a wavelength of less than 300 nm was not included) for secondary curing to obtain a second shaped object.

[0078] A third shaped object was obtained from this second shaped object in the same manner as in Example 1.

[0079] Different from Example 3, this third shaped object did not form an irradiation region, and as it was, pretreatment with a pretreatment liquid for electroless plating and electroless gold plating with an electroless gold plating liquid were performed in the same manner as in Example 3. As a result, as a structure in the shape of a metal wiring pattern according to Example 5, a metal structure similar to the metal structure according to Example 3 was obtained.

[0080] (Example 6) Example 6 is different from Example 1. Instead of using a ready-made radical-curable photocurable resin solution, as the radical-curable photocurable resin solution, 89% of a bifunctional acrylate monomer (product name: IRR 214-K) and 1% of an acylphosphine oxide-based photoinitiator (product name: Omnirad TPO H, manufactured by IGM Resins B.V., containing 99% of 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide as the main component) were mixed to prepare a resin solution. Further, a sulfonic acid-based acid catalyst (product name: CYCAT4040) was used instead of the phosphate-based acid catalyst (product name: NACURE 4167, manufactured by Kusumoto Chemicals, containing 25% of phosphate and 75% of a mixed solvent of isopropanol and isobutanol as the main components). Otherwise, it was the same as Example 1. Similar to Example 1, a three-dimensional metal structure along the surface of the third shaped object could be obtained by electroless gold plating.

[0081] (Example 7) Example 7 is different from Example 1. Instead of using a ready-made radical-curable photocurable resin solution (product name: Clear Resin), 90% of another ready-made radical-curable photocurable resin solution (product name: High Temp, manufactured by formlabs, containing 60 - 80% of acrylate monomer, 25 - 45% of urethane acrylate, and 1.5% of an acylphosphine oxide-based photoinitiator as the main components) was used, and the resin solution for forming the shaped object was prepared in the same manner as in Example 1 for the rest.

[0082] For the three-dimensional shaping of the first shaped object, an SLA-type stereolithography 3D printer (product name: Space Art, manufactured by TKR), which is different from that in Example 1, was used. Otherwise, the first and second shaped objects were obtained in the same manner as in Example 1.

[0083] The second shaped object, different from Example 1, was charged into an atmospheric oven with an internal ambient temperature of 280°C and heated. The heating time (holding time in the oven) was set to 3 minutes. Thereby, the second shaped object was thermally cured to obtain the third shaped object.

[0084] Similarly to Example 1, an electrolytic nickel plating was carried out to obtain a three-dimensional structure of metal having a shape along the surface of the third shaped article.

[0085] (Example 8) In Example 8, the formulation amounts of the photo radical curable photocurable resin liquid and the thermosetting resin were changed to confirm the influence on the metal structure.

[0086] In Example 8, different from Example 1, instead of the existing photo radical curable photocurable resin liquid, as the photo radical curable photocurable resin liquid, 80% of a bifunctional acrylate monomer (product name: IRR 214-K), 19% of a bifunctional acrylate monomer (product name: HDDA), and 1% of an acylphosphine oxide-based photopolymerization initiator (product name: Omnirad TPO H, manufactured by IGM Resins B.V., containing 99% of 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide as the main component) were mixed resin liquid was used.

[0087] As in Example 1, a methylol melamine crosslinking agent (product name: CYMEL303LF) was used as the thermosetting resin.

[0088] As in Example 1, an acid catalyst (product name: CYCAT4040) was also used as the acid catalyst.

[0089] The above photo radical curable photocurable resin liquid, thermosetting resin, and acid catalyst were formulated as shown in Table 1 below to prepare resin liquids 1 to 7 for forming shaped articles with different contents of methylol melamine crosslinking agent (thermosetting resin).

[0090]

Table 1

[0091] For the three-dimensional shaping of the first shaped object, an SLA-based stereolithography 3D printer (product name: Space Art, manufactured by TKR), which is different from that in Example 1, was used, and the shape to be shaped was a cubic frame (12 sides). Otherwise, in the same manner as in Example 1, after obtaining the third shaped object using Resin Liquids 1 to 7, electroless gold plating was performed on each of the third shaped objects in the same manner as in Example 1.

[0092] Regarding the third shaped object using Resin Liquids 1 to 7 and the electroless gold plating applied thereto, the formability and the quality of the plating were evaluated.

[0093] The evaluation of the formability of the third shaped object was performed by measuring the length of four sides. The evaluation was divided into three levels. Those that could be shaped as per the shaping design information data (drawing) used in the 3D printer were evaluated as good, i.e., Evaluation A. When a dimensional error of 10% or more and 20% or less occurred with respect to the design information data and deformation was observed in the third shaped object, it was evaluated as Evaluation B. Those with further deformation than Evaluation B were defined as Evaluation C, which is a defective non-shapable case. In other words, when it could be shaped better than Evaluation B, it was Evaluation A.

[0094] The evaluation of the plating on the third shaped object was performed based on the measurement results of the gold film thickness at six points using a fluorescent X-ray film thickness measuring device (SFT9550, manufactured by Hitachi High-Technologies Corporation). The evaluation was divided into three levels. Those in which a gold film with an average film thickness of 150 to 250 nm could be formed on the surface of the shaped object were evaluated as good, i.e., Evaluation A. When a gold film with an average film thickness of 50 to 150 nm was formed, it was evaluated as Evaluation B, which is a non-uniform plating film. When the detected average film thickness was less than 50 nm, it was defined as Evaluation C, which is no plating deposition.

[0095] The following Table 2 shows the evaluation results of the formability and the evaluation results of the plating for the third shaped object using Resin Liquids 1 to 7 and the electroless gold plating applied thereto. Also, FIGS. 5, 6, and 7 show photographs of the third shaped objects using Resin Liquids 1, 3, and 7, i.e., the shaped objects with a thermosetting resin content of 1%, 10%, and 70%.

[0096]

Table 2

[0097] As shown in Table 2, when the resin liquid for forming a shaped article is Resin Liquids 2 to 6 (the content of the thermosetting resin is 5% to 50%) (for example, see FIG. 6), the formability and plating property were good. On the other hand, when the content of the thermosetting resin is 1%, exposure of the base material was observed and the plating was not good (for example, see FIG. 5). Further, when the content of the thermosetting resin is 70%, it is shaped into a distorted shape, a dimensional error exceeding 20% occurs and it is a poor shape, and plating could not be performed either (for example, see FIG. 7). Therefore, the content of the thermosetting resin in the resin liquid for forming a shaped article may be 3% by weight or more and 60% by weight or less, and preferably 5% by weight or more and 50% by weight or less.

[0098] As shown in these examples, according to the resin liquid and the shaped article forming method according to the present embodiment, a shaped article including a three-dimensional structure of a metal can be easily constructed. The three-dimensional structure of a metal that can be constructed by the resin liquid and the shaped article forming method according to the present embodiment can be used, for example, as an electrical wiring pattern.

[0099] As described above, it is possible to provide a resin liquid and a shaped article forming method suitable for manufacturing a shaped article including a three-dimensional structure of a metal.

[0100] In addition, the configurations disclosed in the above-described embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in other embodiments as long as no contradiction occurs. Further, the embodiments disclosed in this specification are examples, and the embodiments of the present disclosure are not limited thereto, and can be appropriately modified within the scope not departing from the object of the present disclosure.

Industrial Applicability

[0101] The present disclosure can be applied to a resin liquid and a shaped article forming method.

Explanation of Signs

[0102] 11: Structure 31, 32, 33, 34, 35: Structures 40: Helical tunnel space 41: Structure

Claims

1. It contains a photo-radical curable resin, a thermosetting resin, and an acid catalyst. As the thermosetting resin, it contains a melamine-based crosslinking agent or a benzoguanamine-based crosslinking agent. Furthermore, it is shaped using a resin liquid containing 3% by weight or more and 60% by weight or less of the thermosetting resin to obtain a first shaped object, which is a shaping step; A finishing photo-curing step of irradiating the first shaped object with light having a wavelength of 300 nm or more to photo-cure it to obtain a second shaped object; A thermosetting step of heating the second shaped object to 60°C or more and 280°C or less to thermoset it to obtain a third shaped object; A pattern forming step of irradiating a part of the surface of the third shaped object with light having a wavelength of less than 300 nm to form an irradiated region irradiated with light having a wavelength of less than 300 nm and a non-irradiated region not irradiated with light having a wavelength of less than 300 nm. A method for forming a shaped object including a three-dimensional structure of a metal.

2. The method for forming a shaped object including a three-dimensional structure of a metal according to claim 1, further including a catalyst loading step of bringing a pretreatment liquid for electroless plating containing metal nanoparticles and water into contact with the surface of the third shaped object to load the metal nanoparticles on the non-irradiated region of the third shaped object to form a catalyst loading region.

3. The method for forming a shaped object including a three-dimensional structure of a metal according to claim 2, further including a plating step of performing electroless plating on the catalyst loading region.

4. The irradiated region is a region where the amino groups present on the surface of the third shaped object are deactivated, The non-irradiated region is a region where the amino groups are not deactivated but are retained. A method for forming a shaped object including a three-dimensional structure of a metal according to any one of claims 1 to 3.

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