Surface treatment agent, method for producing film-forming substrate, and film-forming substrate

Abstract

The present invention addresses the problem of providing: a surface treatment agent capable of sufficiently enhancing the coatability of a resin composition on both a metal surface and a resin surface when forming a film of the resin composition on a substrate surface; a method for producing the film-forming substrate; and a film-forming substrate.　The present invention is a surface treatment agent or the like for treating a substrate surface including a metal surface and a resin surface, the surface treatment agent comprising 0.001 to 1.2 mass% of an amine compound that is at least one selected from the group consisting of an alkylamine having an alkyl group having 19-24 carbon atoms, an alkenyl amine having an alkenyl group having 18-22 carbon atoms, and a salt thereof.

Description

Surface treatment agent, method for producing film-forming substrate, and film-forming substrate

[0001] The present invention relates to a surface treatment agent, a method for producing a film-formed substrate, and a film-formed substrate.

[0002] A film-formed substrate having a film of a curable resin composition such as a solder resist or an etching resist formed on the surface of a metal substrate is used, for example, as a printed wiring board coated with solder resist while leaving copper openings for electrical connection by soldering. Such a film-formed substrate is generally produced by disposing a resin composition at desired locations on the surface of the metal substrate by printing using a screen plate or a photo method involving exposure and development, but in recent years, a method of forming a film by drawing a resin composition using an inkjet method has attracted attention.

[0003] The inkjet method has the advantage of not requiring a plate or photomask, requiring fewer steps, and easily forming a film only in the required areas. On the other hand, the inkjet method has the problem that it is prone to bleeding after application because it requires the use of a solder resist or the like with a lower viscosity than conventional methods. Techniques for reducing such bleeding include, for example, surface treatment in which a surface treatment agent is brought into contact with the metal surface on the substrate to adjust the wettability of the metal surface, as described in Patent Documents 1 to 4.

[0004] However, while these conventional surface treatment techniques can improve the wettability of the metal surface on the substrate, they are insufficient in modifying the resin surface when a resin surface is also present on the substrate. Generally, in addition to metal, resin surfaces such as insulating resins may also be present on the substrate surface, and there is a demand for improving the coatability of solder resist on both the metal surface and the resin surface.

[0005] Patent Document 1: JP 2015-192963 A, International Publication No. 2016 / 111035 Pamphlet, International Publication No. 2016 / 111036 Pamphlet, International Publication No. 2019 / 082681 Pamphlet

[0006] The present invention has been made in consideration of the problems of the prior art as described above, and an object of the present invention is to provide a surface treatment agent, a method for producing a film-formed substrate, and a film-formed substrate that can sufficiently improve the coatability of a resin composition on both the metal surface and the resin surface when a film of a resin composition is formed on the surface of a substrate.

[0007] The surface treatment agent of the present invention is a surface treatment agent for treating substrate surfaces, including metal surfaces and resin surfaces, which contains 0.001 mass % or more and 1.2 mass % or less of an amine compound that is at least one kind selected from the group consisting of alkylamines in which the alkyl group has 19 to 24 carbon atoms, alkenylamines in which the alkenyl group has 18 to 22 carbon atoms, and salts thereof.

[0008] In the surface treatment agent of the present invention, the amine compound may be at least one selected from the group consisting of aminononadecane, arachidylamine, henicosylamine, behenylamine, tricosylamine, tetracosylamine, and oleylamine.

[0009] The surface treatment agent of the present invention may have a pH of 4.0 or more and 14 or less.

[0010] The method for producing a film-formed substrate of the present invention is a method for producing a film-formed substrate having a film of a resin composition formed on the surface of the substrate, the method comprising: a surface treatment step of bringing a surface treatment agent into contact with the surface of a substrate having a metal surface and a resin surface, thereby treating the surface so that the contact angles of the metal surface and the resin surface with dipropylene glycol are 35° or more and 100° or less; and a film formation step of forming a film of a resin composition on the surface of the surface-treated substrate by an inkjet method.

[0011] In the method for producing a film-forming substrate of the present invention, the surface treatment agent may contain 0.001% by mass or more and 1.2% by mass or less of an amine compound that is at least one selected from the group consisting of alkylamines having an alkyl group with 19 to 24 carbon atoms, alkenylamines having an alkenyl group with 18 to 22 carbon atoms, and salts thereof.

[0012] In the method for producing a film-formed substrate of the present invention, in the film-forming step, the film may be formed by an inkjet method using a resin composition that is cured by heating, ultraviolet irradiation, or light irradiation.

[0013] The method for producing a film-formed substrate of the present invention may further include, prior to the surface treatment step, an etching step of etching the surface of the substrate with a microetching agent.

[0014] In the method for producing a film-formed substrate of the present invention, in the etching step, the metal surface may be etched so that the surface roughness (Ra) is 0.1 μm or more and 0.8 μm or less.

[0015] In the method for producing a film-forming substrate of the present invention, the surface treatment agent may have a pH of 4.0 or more and 14 or less.

[0016] The film-forming substrate of the present invention is a film-forming substrate having a substrate surface including a metal surface and a resin surface, wherein the contact angles of the metal surface and the resin surface with dipropylene glycol are 35° or more and 100° or less, and the surface roughness (Ra) of the metal surface is 0.1 μm or more and 0.8 μm or less, and wherein a film of a resin composition is formed on the substrate surface.

[0017] In the film-forming substrate of the present invention, the resin surface may contain at least one resin selected from the group consisting of polyimide resin, epoxy resin, polyethylene terephthalate resin, polypropylene resin, polyvinyl chloride resin, polyolefin resin, polyurethane resin, and polyacetal resin.

[0018] In the film-forming substrate of the present invention, the resin composition may be cured by heating, ultraviolet irradiation, or light irradiation.

[0019] According to the present invention, when a film of a resin composition is formed on the surface of a substrate, the coatability of the resin composition on both the metal surface and the resin surface can be sufficiently improved.

[0020] Hereinafter, embodiments of the surface treatment agent, the method for producing a film-formed substrate (hereinafter also simply referred to as the production method), and the film-formed substrate of the present invention will be described.

[0021] (First Embodiment: Surface Treatment Agent) The surface treatment agent of this embodiment is a surface treatment agent for treating a substrate surface, including a metal surface and a resin surface, containing 0.001 mass % to 1.2 mass % of at least one amine compound selected from the group consisting of alkylamines having an alkyl group with 19 to 24 carbon atoms, alkenylamines having an alkyl group with 18 to 22 carbon atoms, and salts thereof. By treating the surface of a substrate, including a metal surface and a resin surface, with the surface treatment agent of this embodiment, it is possible to adjust the treated surface to a desired contact angle, as described below.

[0022] <Substrate> The substrate to be treated with the surface treatment agent of the present embodiment is not particularly limited as long as it is a substrate having a metal surface and a resin surface, and examples thereof include circuit boards used in printed wiring boards and the like, and part or all of other various electronic and electrical devices, medical devices, vehicle-mounted devices, automobile parts, parts for marine equipment, and the like.

[0023] The metal constituting the metal surface is not particularly limited, but examples thereof include copper, tin, stainless steel, aluminum, nickel, titanium, and alloys thereof.

[0024] The resin constituting the resin surface is not particularly limited, and examples thereof include at least one resin selected from the group consisting of polyimide resin, epoxy resin, polyethylene terephthalate resin, polypropylene resin, polyvinyl chloride resin, polyolefin resin, polyurethane resin, and polyacetal resin. Epoxy resin is a resin that is often used for FR-4 substrates, which are materials for circuit boards used in printed wiring boards and the like. When the surface treatment agent of this embodiment is used for a circuit board made of a substrate (such as an FR-4 substrate) using an epoxy resin, the metal portion and the epoxy resin portion of the FR-4 substrate become the metal surface and the resin surface present on the substrate surface, and the surface treatment agent of this embodiment comes into contact with both of these surfaces, allowing both surfaces to be surface-treated.

[0025] <Amine Compound> The surface treatment agent of this embodiment contains 0.001% by mass or more and 1.2% by mass or less of at least one amine compound selected from the group consisting of alkylamines (hereinafter simply referred to as alkylamines) in which the alkyl group has 19 to 24 carbon atoms, alkenylamines (hereinafter simply referred to as alkenylamines) in which the alkenyl group has 18 to 22 carbon atoms, and salts thereof. In this embodiment, alkylamines and alkenylamines refer to amine compounds that are aliphatic primary amines and are selected from the group consisting of alkyl groups or alkenyl groups in which the carbon numbers of the aliphatic hydrocarbon groups constituting the alkylamines are the respective carbon numbers mentioned above.

[0026] Examples of the alkylamine include aminononadecane (nonadecylamine) (carbon number: 19), arachidylamine (icosylamine) (carbon number: 20), henicosylamine (carbon number: 21), behenylamine (carbon number: 22), tricosylamine (carbon number: 23), tetracosylamine (carbon number: 24), etc. Examples of the alkenylamine include oleylamine (carbon number: 18), cis-13-docosenamide (carbon number: 22), etc.

[0027] Examples of the salts of alkylamines and alkenylamines include organic acid salts and inorganic acid salts of alkylamines, organic acid salts and inorganic acid salts of alkenylamines, etc. These amine compounds may be used alone or in combination of two or more.

[0028] The content of the amine compound in the surface treatment agent is 0.001% by mass to 1.2% by mass, or 0.003% by mass to 1.2% by mass, or 0.005% by mass to 1.0% by mass, or 0.01% by mass to 0.3% by mass. By having the content in this range, it is possible to improve the coatability of the resin composition to both the metal and resin surfaces.

[0029] The pH of the surface treatment agent of the present embodiment is not particularly limited, but may be, for example, pH 4.0 or higher and pH 14 or lower, or pH 5.0 or higher and pH 13 or lower, or pH 6.0 or higher and pH 12 or lower. When the surface treatment agent has a pH in the above range, it is preferable because the contact angle can be easily adjusted to the desired range.

[0030] The optimum pH of the surface treatment agent can be appropriately selected depending on the type of amine compound and the type of resin composition from which the film is formed, but for example, when the amine compound contained in the surface treatment agent is an alkenylamine, the pH is preferably 4.0 or more and 14 or less. When the amine compound contained in the surface treatment agent is an alkylamine, the pH is preferably 5.0 or more and 11.0 or less, or 6.0 or more and 10 or less.

[0031] The pH of the surface treatment agent can be adjusted by blending the above-mentioned amine compounds or other known pH adjusters. The pH adjuster is not particularly limited, but examples thereof include those used for pH adjustment, such as hydrochloric acid, sulfuric acid, acetic acid, sodium hydroxide, ammonia, ethanolamine, or salts thereof (e.g., sodium acetate), acetate buffer, phosphate buffer, citrate buffer, citrate phosphate buffer, borate buffer, and Good's buffer, as well as common buffers, chelating agents, and amino acids.

[0032] By treating a metal surface and a resin surface with the surface treatment agent of this embodiment, the contact angles of both surfaces can be easily adjusted to a desired range. Here, the desired contact angle range refers to a predetermined range of contact angles of both surfaces with dipropylene glycol. Examples of the desired contact angle range include contact angles of both the metal surface and the resin surface with dipropylene glycol of 35° to 100°, or 36° to 95°, or 36° to 90°. When the contact angles of both the metal surface and the resin surface with dipropylene glycol are within the above ranges, the application of the resin composition is not impaired, and bleeding can be easily suppressed. More specifically, the contact angle of the metal surface with dipropylene glycol can be 35° to 100°, or 36° to 95°, or 37° to 90°. The contact angle of the resin surface with dipropylene glycol is 35° or more and 100° or less, or 37° or more and 75° or less, or 40° or more and 70° or less.

[0033] In this embodiment, the reason for evaluating the coatability of a resin composition by setting the contact angle with dipropylene glycol within a specific range is as follows. Conventionally, when evaluating the coatability, such as adhesion or spreadability, of a specific substance on the surface of a specific material, the contact angle with the substance has been measured. However, in this case, it is necessary to obtain the specific resin composition to perform the measurement, and it is difficult to measure for compositions that are difficult to obtain. In addition, there is a drawback in that the measurement must be performed for each resin composition, and it is time-consuming to evaluate the coatability of many resin compositions.

[0034] In the case of resin compositions, particularly those that are cured by heating, ultraviolet irradiation, light irradiation, or the like, such as etching resist inks and solder resist inks described below, they are applied to circuit boards or the like in an uncured state to form a film, and therefore it is required to adjust the contact angle of the substrate surface to an appropriate range for the resin composition in an uncured state (the state in which it is actually applied). However, it is extremely cumbersome to obtain all of the wide variety of products, measure the contact angles, and select a resin composition suitable for a specific substrate.

[0035] On the other hand, JIS R3257 "Test method for wettability of substrate glass surface" describes a method for determining the wettability of a substrate glass surface by measuring the contact angle using distilled water. However, since the physical properties of distilled water and a resin composition are significantly different, the contact angle measured using distilled water is not necessarily appropriate for evaluating the adhesion or bleeding tendency of a resin composition.

[0036] From this perspective, investigations were conducted into measurement substances that can be used as substitutes for resin compositions, particularly curable resin compositions such as solder resist, which are suitable for use with the surface treatment agent of this embodiment. As a result, it was found that the free energy of dipropylene glycol is relatively close to that of curable resin compositions, and further that there is a correlation with the contact angle when various curable resin compositions are used, making it ideal for measuring the contact angle of this embodiment.

[0037] Therefore, the contact angle in this embodiment refers to a value measured by the sessile drop method described in JIS R3257 "Test method for wettability of substrate glass surfaces" by replacing distilled water with dipropylene glycol. Specifically, it refers to a value measured by the method shown in the examples described later.

[0038] The surface treatment agent of the present embodiment may contain, in addition to the amine compound, any other components such as an antifoaming agent, a rust inhibitor, a solvent, etc. The surface treatment agent of the present embodiment is preferably a solution in which the amine compound and other components are dissolved in water or another known solvent.

[0039] (Second embodiment: manufacturing method of film-formed substrate) The manufacturing method of the film-formed substrate of this embodiment is a manufacturing method of a film-formed substrate, which includes a surface treatment step of bringing a surface treatment agent into contact with a substrate surface having a metal surface and a resin surface, thereby performing surface treatment so that the contact angles of the metal surface and the resin surface with dipropylene glycol are 35° or more and 100° or less, and a film formation step of forming a film of a resin composition on the surface of the surface-treated substrate by an inkjet method.

[0040] <Film-Formed Substrate> The film-formed substrate produced by the production method of this embodiment is a substrate similar to the substrate in the first embodiment, and is not particularly limited as long as it is a substrate on whose surface a film of a resin composition is formed by an inkjet method.

[0041] Examples of the metal constituting the metal surface of the film-formed substrate include metals similar to the metals constituting the metal surface of the substrate in the first embodiment. Examples of the resin constituting the resin surface of the film-formed substrate include resins similar to the resins constituting the resin surface of the substrate in the first embodiment. Neither the metal nor the resin is limited to the above examples.

[0042] The manufacturing method of this embodiment is particularly suitable for manufacturing a circuit board in which a solder resist is formed as a film on a substrate having a conductor surface (metal surface) made of a metal containing copper, such as copper or a copper alloy (hereinafter simply referred to as copper), and an insulating resin surface.

[0043] <Etching Step> The manufacturing method of this embodiment may optionally include an etching step of etching the substrate surface with a microetching agent prior to the surface treatment step.

[0044] The microetching agent used in the etching process refers to an etching agent that, when brought into contact with a metal surface, slightly etches the metal surface to form fine irregularities on the metal surface (microetching). The microetching agent used in this embodiment is not particularly limited as long as it can microetch the metal that constitutes the metal surface. For example, when the metal is copper, known copper microetching agents, specifically organic acid-based, sulfuric acid-hydrogen peroxide-based, and persulfate-based etching agents, can be used.

[0045] Preferred microetching agents include organic acid-based microetching agents, such as commercially available microetching agents such as aqueous solutions containing organic acids, cupric ions, halide ions, amino group-containing compounds, polymers, etc.

[0046] In the etching process, a microetching agent is brought into contact with the metal surface to etch the surface, forming fine irregularities on the surface. The formation of such fine irregularities improves adhesion between the metal surface and the resin composition. The treatment conditions in the etching process, i.e., treatment time, temperature during treatment with the microetching agent, treatment method such as spraying or immersion treatment, etc., can be adjusted appropriately. In this embodiment, since a resin surface also exists on the substrate surface, the resin surface may also be brought into contact with the etching solution during the etching process, or a resist or the like may be provided on the resin surface to prevent contact with the etching solution.

[0047] In the etching step, the metal surface is treated, for example, so that the surface roughness (Ra) is 0.1 μm or more and 0.8 μm or less, or 0.3 μm or more and 0.7 μm or less. By treating the metal surface so that the surface roughness falls within this range, the adhesion between the metal surface and the resin composition after the subsequent surface treatment step is improved, and bleeding of the resin composition can be suppressed, which makes it easier to improve the coatability. Note that the surface roughness (Ra) in this embodiment refers to the arithmetic mean roughness measured in accordance with JIS B 0601 (2013).

[0048] The amount of etching by gravimetric method in the etching step is preferably adjusted appropriately to achieve the above-mentioned surface roughness, for example, about 0.5 μm to 2.0 μm, or about 0.7 μm to 1.5 μm. By setting the amount of etching within the above range, it becomes easier to achieve an appropriate surface roughness, and therefore it becomes easier to improve the adhesion between the metal surface and the resin composition after the subsequent surface treatment step.

[0049] By carrying out the etching step, it is possible to sufficiently improve the adhesion between the resin composition and both the metal surface and the resin surface, and at the same time, by carrying out the surface treatment step, it is possible to suppress the metal surface from being roughened after the etching step, which makes bleeding more likely to occur, and therefore it is possible to sufficiently improve both the bleeding suppression effect of the resin composition and the adhesion between the resin composition and both the metal surface and the resin surface.

[0050] <Surface Treatment Step> The manufacturing method of this embodiment includes a surface treatment step of bringing a surface of a substrate having a metal surface and a resin surface into contact with a surface treatment agent to perform surface treatment so that the contact angles of the metal surface and the resin surface with dipropylene glycol are 35° or more and 100° or less.

[0051] In the surface treatment step of this embodiment, when the etching step is carried out, the treatment is carried out using a surface treatment agent capable of adjusting the contact angle of the micro-etched metal surface and resin surface as described above.

[0052] The surface treatment agent that can be used in this embodiment is not particularly limited as long as it is a surface treatment agent that can adjust the contact angle of the metal surface and the resin surface to the above-mentioned range. However, when the surface treatment agent is the surface treatment agent of this embodiment described in the first embodiment, the effect of the production method of this embodiment can be further enhanced.

[0053] Examples of surface treatment agents that can be used in this embodiment include the surface treatment agent of the first embodiment described above, as well as solutions containing, as active ingredients, anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactant solutions, etc. The active ingredients of the surface treatment agent may be used alone or in combination of two or more. In addition to the active ingredients, the surface treatment agent may also contain other optional ingredients such as an antifoaming agent, a rust inhibitor, a solvent, etc. The surface treatment agent is preferably a solution in which the active ingredients and other ingredients are dissolved in water or another known solvent.

[0054] In the surface treatment step of this embodiment, known means can be used for the treatment. For example, the means for contacting the surface treatment agent with the surface of the metal substrate is not particularly limited, and examples thereof include surface treatment means using known liquid agents such as immersion and spraying. The temperature of the surface treatment agent is not particularly limited, and examples thereof include 20°C to 40°C, or 25°C to 35°C. Furthermore, the time for treatment with the surface treatment agent (contact time between the surface treatment agent and the metal substrate) is not particularly limited, and examples thereof include 10 seconds to 2 minutes, or 30 seconds to 1 minute.

[0055] The surface treatment is performed so that the contact angles of the metal surface and the resin surface with dipropylene glycol after the surface treatment are both 35° to 100°, or 36° to 95°, or 36° to 90°. By setting the contact angles of the metal surface and the resin surface with dipropylene glycol within the above ranges, the application of the resin composition is not hindered, adhesion is maintained, and bleeding can be easily suppressed. More specifically, the contact angle of the metal surface with dipropylene glycol can be 35° to 100°, or 36° to 95°, or 37° to 70°. The contact angle of the resin surface with dipropylene glycol can be 35° to 100°, or 37° to 75°, or 40° to 70°.

[0056] Furthermore, when a microetching step is carried out prior to the surface treatment step, the contact angle of the microetched metal surface with dipropylene glycol is, for example, 35° or more and 100° or less, or 40° or more and 95° or less, or 45° or more and 90° or less.

[0057] When the manufacturing method of this embodiment is employed in the manufacture of a circuit board, by setting the contact angles of the metal surface, which is the conductor surface, and the resin surface, which is the insulator, with dipropylene glycol within the above range, bleeding and the like can be suppressed when a curable resin such as an etching resist or a solder resist is formed as a film of a resin composition in a subsequent film formation step.

[0058] <Film Forming Step> The manufacturing method of this embodiment includes a film forming step of forming a film of a resin composition on the surface of the surface-treated metal substrate by an inkjet method.

[0059] Examples of resin compositions used in the film formation process of this embodiment include curable resin compositions such as etching resist ink and solder resist ink, which are cured by heating, ultraviolet light, or light irradiation. While known etching resist inks and solder resist inks can be appropriately selected and used, it is preferable that they have a viscosity adjusted to a level that allows application by inkjet printing. For example, etching resist inks are desirable as resin compositions that are cured by ultraviolet light after application and can be stripped with an alkaline aqueous solution. Specific examples include those containing a carboxyl group-containing monomer, a monofunctional monomer, a polyfunctional monomer, a photopolymerization initiator, and other optional components. Preferred solder resist inks are resin compositions that are curable by heat, ultraviolet light, or light irradiation and that are heat-resistant after curing. Specific examples include those containing a combination of the various monomers used in the etching resist ink, as well as a curing agent such as an epoxy compound or an isocyanate compound and various optional components.

[0060] In the film formation step, a known inkjet device is used to apply a resin composition in a desired pattern to a metal surface and / or a resin surface that has been subjected to an etching treatment and a surface treatment. For example, the manufacturing method of this embodiment can be applied when applying a solder resist to the outermost layer of a printed wiring board, or when applying an etching resist or a plating resist to an inner layer.

[0061] In the manufacturing method of this embodiment, an additional treatment step may be performed after the film formation step. For example, after forming a solder resist film in the film formation step, a plating step may be performed in which plating is performed on the metal surface exposed through the openings in the solder resist. In this case, by performing the etching step and surface treatment step as described above, the adhesion of the resin composition such as the solder resist can be improved and the penetration of the plating solution can be suppressed.

[0062] In the manufacturing method of this embodiment, known processing steps such as a cleaning step and a drying step may be carried out between the etching step, the surface treatment step and the film formation step.

[0063] (Third embodiment: film-formed substrate) Next, the film-formed substrate of this embodiment will be described. The film-formed substrate of this embodiment is not limited to being produced by the above-mentioned method for producing a film-formed substrate of this embodiment and / or by using the surface treatment agent of this embodiment, but can also be produced by the production method of this embodiment and / or by using the surface treatment agent of this embodiment.

[0064] The film-formed substrate of this embodiment is a film-formed substrate in which a film of a resin composition is formed on the surface of a metal substrate, and the contact angle of the metal substrate surface is 35° or more and 100° or less and the surface roughness (Ra) is 0.1 μm or more and 0.8 μm or less.

[0065] The film-formed substrate of this embodiment is a substrate that can suppress the bleeding of the resin composition and has high adhesion between the resin composition and the metal surface and the resin surface. The film-formed substrate of this embodiment can be used as a printed wiring board or the like in which a solder resist film as a resin composition is formed between metal conductors as a metal surface. In addition, it can be used for, for example, various electronic and electrical devices, medical devices, vehicle-mounted devices, automobile parts, parts for marine equipment, etc.

[0066] The surface treatment agent, the method for producing a film-formed substrate, and the film-formed substrate according to the present embodiment are as described above, but the embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims rather than the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0067] Next, examples of the present invention will be described together with comparative examples, but the present invention should not be construed as being limited to the following examples.

[0068] "Test 1" <Preparation of Test Substrate> A plated plate (manufactured by Aiko Machinery Manufacturing Co., Ltd.: 12 cm x 12 cm) having a copper plating layer with a thickness of 35 μm was prepared as a test substrate. Furthermore, this test substrate was etched by spraying an organic acid microetching agent (manufactured by MEC Co., Ltd., CZ series) on one side at a temperature of 25°C and a spray pressure of 0.1 MPa, adjusting the etching time so that an etching depth of 1.0 μm was achieved on one side of the test substrate. The surface that was rinsed with water was used as the treated surface, and a microetched substrate was prepared. Furthermore, a copper-clad laminate material for printed circuits (trade name MCL-E-67, manufactured by Resonac Co., Ltd.) was cut to a size of 12 cm x 12 cm, and the resin surface (epoxy resin) was used as the treated surface, and a resin substrate was prepared.

[0069] <Surface Treatment Agent> An aqueous solution of each amine compound listed in Table 1 (temperature 25°C, concentration 0.1% by mass) was prepared, and surface treatment agents were prepared by adjusting the solution with hydrochloric acid (35%) and aqueous sodium hydroxide solution (24%) to the pH values ​​listed in Table 1. The pH was measured using a pH / ION METER F-72 (manufactured by HORIBA). A test substrate, a microetched substrate, and a resin substrate constituted a set, and the treated surfaces were treated with each surface treatment agent, as Examples 1 to 20. The surface treatment was performed by immersing the treated surface of each substrate for the time listed in Table 1, followed by rinsing with water and drying. The amine compounds used were as follows: Oleylamine (manufactured by NOF Corporation, carbon number 18 / alkenylamine) Aminononadecane (manufactured by Tokyo Chemical Industry Co., Ltd., carbon number 19 / alkylamine) Behenylamine (manufactured by NOF Corporation, carbon number 22 / alkylamine)

[0070] <Contact Angle Measurement 1> The contact angles of the above surface-treated substrates with respect to dipropylene glycol, solder resist, and distilled water were measured. The contact angle of each test substrate was measured using the sessile drop method described in JIS R3257, "Test method for wettability of substrate glass surfaces." The measurement device used was an automatic contact angle meter DM-501 manufactured by Kyowa Interface Science Co., Ltd. For the measurement of the contact angle with dipropylene glycol, dipropylene glycol (manufactured by Kishida Chemical Co., Ltd.) was used instead of the distilled water described in JIS R3257. For the measurement of the contact angle with solder resist, solder resist (manufactured by Taiyo Ink Co., Ltd., product number IJSR-4000) was used instead of the distilled water described in JIS R3257. The results are shown in Table 1.

[0071]

[0072] As shown in Table 1, in all examples, the contact angles of the test substrate, etched substrate, and resin substrate with dipropylene glycol increased compared to the untreated substrate (comparison example), and could be adjusted to a range of 35° to 100°. For aminononadecane and behenylamine, the contact angles sometimes fell outside this range at pH 12 or higher, but adjusting the pH to less than 10 brought the contact angles within the above range. Furthermore, a comparison of the contact angle measurements with dipropylene glycol and solder resist reveals a correlation when treated with the same amine compound at the same pH. On the other hand, no significant improvement in the contact angle with distilled water was observed for the untreated substrate (comparison example), particularly the resin substrate, with any of the surface treatment agents. In other words, it can be seen that there is no correlation between the contact angle with solder resist and the contact angle with distilled water.

[0073] "Test 2" A surface treatment agent was prepared in the same manner as in Test 1 above, using amine compounds consisting of alkylamines and alkenylamines with different carbon numbers. The pH was adjusted to 10. The amine compounds used were as follows: oleylamine (NOF Corporation, C18 / alkenylamine); aminononadecane (Tokyo Chemical Industry Co., Ltd., C19 / alkylamine); behenylamine (NOF Corporation, C22 / alkylamine); hexylamine (Tokyo Chemical Industry Co., Ltd., C6 / alkylamine); octylamine (Kishida Chemical Co., Ltd., C8 / alkylamine); dodecylamine (Kishida Chemical Co., Ltd., C12 / alkylamine); and tetradecylamine (Tokyo Chemical Industry Co., Ltd., C14 / alkylamine). Test substrates were the same as the etched substrates and resin substrates used in Test 1 above. Each test substrate was surface treated in the same manner as in Test 1, and the contact angle with dipropylene glycol was measured in the same manner as in Test 1. The results are shown in Table 2.

[0074]

[0075] As shown in Table 2, alkylamines with a small number of carbon atoms can improve the contact angle of an etched substrate to some extent, but cannot improve the contact angle of a resin substrate sufficiently.

[0076] "Test 3" Instead of the copper-clad laminate material for printed circuits using the epoxy resin used in Tests 1 and 2, a polyimide resin plate (thickness 0.04 mm, size 40 mm x 40 mm, product name: Kapton, manufactured by DuPont-Toray Co., Ltd.) was used as the resin substrate. This was treated with the surface treatment agent used in Test 2 in the same manner as in Test 1, and the contact angle with dipropylene glycol was measured. The results are shown in Table 3.

[0077]

[0078] As shown in Table 3, the contact angle with respect to polyimide resin was improved compared to the untreated case, and a contact angle of 35° or more was obtained in each example.

[0079] "Test 4" A surface treatment agent was prepared using oleylamine, one of the amine compounds used in Test 1. The pH was adjusted to 8.6. The oleylamine concentration was adjusted to six different concentrations, ranging from 0.001% by mass to 1.2% by mass, and the same substrates as the etched substrate and resin substrate used in Test 1 were treated in the same manner as in Test 1, and the contact angle with dipropylene glycol was measured. The results are shown in Table 4.

[0080]

[0081] As shown in Table 4, the contact angle was improved compared to the untreated substrate at any concentration.

[0082] Test 5: Measurement of Bleed Width The bleed width of the solder resist was measured using the etched substrate and resin substrate used in Test 1 above. Each test substrate was treated in the same manner as Test 1 with a solution of each amine compound listed in Table 5. A solder resist (manufactured by Taiyo Ink Co., Ltd., product number IJSR-4000) serving as a resin composition was then applied to the substrate using an inkjet solder resist applicator (device name: CPS6151, manufactured by Microcraft Co., Ltd.) with a target line width of 100 μm. After application, the substrate was allowed to fully cure. Note that a commercially available dissolution aid was added to each amine compound solution if undissolved amine compound was visually observed after mixing. Each cured test substrate was photographed with an optical microscope (device name: Digital Microscope VHS-5000, manufactured by KEYENCE Corporation), and the line width was measured at any five points on the photograph. The average of the five points was calculated. As controls, similar measurements were also performed on untreated substrates (etched substrate and resin substrate) without any surface treatment. The results are shown in Table 6.

[0083]

[0084]

[0085] As shown in Table 6, for the etched substrate, both the Examples and the Comparative Example achieved a line width closer to the target of 100 μm than the untreated substrate, i.e., bleeding was suppressed. For the resin substrate, bleeding was suppressed compared to the untreated substrate in each Example, but was equivalent to the untreated substrate in the Comparative Example.

Claims

1. A surface treatment agent for treating substrate surfaces, including metal surfaces and resin surfaces, containing 0.001% by mass or more and 1.2% by mass or less of at least one amine compound selected from the group consisting of alkylamines in which the alkyl group has 19 to 24 carbon atoms, alkenylamines in which the alkenyl group has 18 to 22 carbon atoms, and salts thereof.

2. The surface treatment agent according to claim 1, wherein the amine compound is at least one selected from the group consisting of aminononadecane, arachidylamine, henicosylamine, behenylamine, tricosylamine, tetracosylamine, and oleylamine.

3. The surface treatment agent according to claim 1 or 2, wherein the pH of the surface treatment agent is 4.0 or more and 14 or less.

4. A method for producing a film-formed substrate, comprising: a surface treatment step of contacting a substrate surface having a metal surface and a resin surface with a surface treatment agent to treat the surface so that the contact angles of the metal surface and the resin surface with dipropylene glycol are 35° or more and 100° or less; and a film formation step of forming a film of a resin composition on the surface of the surface-treated substrate by an inkjet method.

5. The method for producing a film-forming substrate according to claim 4, wherein the surface treatment agent contains 0.001% by mass or more and 1.2% by mass or less of at least one amine compound selected from the group consisting of alkylamines having an alkyl group with 19 to 24 carbon atoms, alkenylamines having an alkenyl group with 18 to 22 carbon atoms, and salts thereof.

6. The method for producing a film-formed substrate according to claim 4 or 5, wherein in the film-forming step, the film is formed by an inkjet method using a resin composition that is cured by heating, ultraviolet irradiation, or light irradiation.

7. The method for producing a film-formed substrate according to claim 4 or 5, further comprising an etching step of etching the substrate surface with a microetching agent prior to the surface treatment step.

8. The method for producing a film-formed substrate according to claim 7, wherein in the etching step, the metal surface is etched so that the surface roughness (Ra) is 0.1 μm or more and 0.8 μm or less.

9. The method for producing a film-forming substrate according to claim 4 or 5, wherein the surface treatment agent has a pH of 4.0 or more and 14 or less.

10. A film-formed substrate having a substrate surface with a metal surface and a resin surface, wherein the contact angles of the metal surface and the resin surface with dipropylene glycol are 35° or more and 100° or less, and the surface roughness (Ra) of the metal surface is 0.1 μm or more and 0.8 μm or less, and wherein a film of a resin composition is formed on the substrate surface.

11. The film-forming substrate according to claim 10, wherein the resin surface contains at least one resin selected from the group consisting of polyimide resin, epoxy resin, polyethylene terephthalate resin, polypropylene resin, polyvinyl chloride resin, polyolefin resin, polyurethane resin, and polyacetal resin.

12. The film-forming substrate according to claim 10 or 11, wherein the resin composition is cured by heating, ultraviolet irradiation, or light irradiation.

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