Surface treatment agent

Abstract

To provide a surface treatment agent which can sufficiently improve coatability of a resin composition with respect to both a metal surface and a resin surface when a film of the resin composition is formed on a base material surface, a method for producing a film formation base material, and a film formation base material.SOLUTION: A surface treatment agent for treating a base material surface including a metal surface and a resin surface contains 0.001 mass% or more and 1.2 mass% or less of an amine compound which is at least one selected from the group consisting of alkylamine having an alkyl group having 19 to 24 carbon atoms, alkenylamine having an alkenyl group having 18 to 22 carbon atoms and salts thereof.SELECTED DRAWING: None

Description

[Technical Field]

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

[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 that it does not require a plate or a photomask, has a small number of steps, and is easy to form a film only on the required area. On the other hand, the inkjet method requires the use of a solder resist or the like with a lower viscosity than conventional methods, which poses a problem of easy bleeding after application. 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 in order 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. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-192963 [Patent Document 2] International Publication No. 2016 / 111035 Brochure [Patent Document 3] International Publication No. 2016 / 111036 Brochure [Patent Document 4] International Publication No. 2019 / 082681 Brochure Summary of the Invention [Problem to be solved by the invention]

[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. [Means for solving the problem]

[0007] The surface treatment agent of the present invention is a surface treatment agent for treating substrate surfaces, including metal surfaces and resin surfaces, containing 0.001 mass % to 1.2 mass % 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.

[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 comprises 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 mass % or more and 1.2 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 comprising 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. [Effects of the Invention]

[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. DETAILED DESCRIPTION OF THE INVENTION

[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 substrate surfaces, including metal surfaces and resin surfaces, containing 0.001 mass % or more and 1.2 mass % or less of an amine compound that is at least one type 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, the treated surface can be adjusted to a desired contact angle as described below.

[0022] <Base material> 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 parts for various other electronic and electrical devices, medical devices, vehicle-mounted devices, automobile parts, and marine equipment.

[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, but 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 in FR-4 substrates, which are materials for circuit boards used in printed wiring boards, etc. When the surface treatment agent of this embodiment is used on a circuit board made of a substrate using an epoxy resin (such as an FR-4 substrate), the metal portion and the epoxy resin portion of the FR-4 substrate become the metal surface and the resin surface present on the surface of the base material, 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 compounds> 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 having an alkyl group with 19 to 24 carbon atoms (hereinafter also simply referred to as alkylamines), alkenylamines having an alkenyl group with 18 to 22 carbon atoms (hereinafter also simply referred to as alkenylamines), and salts thereof. In this embodiment, alkylamine and alkenylamine refer to aliphatic primary amines, which are amine compounds selected from the group consisting of alkyl groups and alkenyl groups, each having the above-mentioned carbon number in the aliphatic hydrocarbon group.

[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), and tetracosylamine (carbon number 24). Examples of the alkenylamine include oleylamine (having 18 carbon atoms) and cis-13-docosenamid (having 22 carbon atoms).

[0027] Examples of the salts of alkylamines and alkenylamines include organic acid salts and inorganic acid salts of alkylamines, and organic acid salts and inorganic acid salts of alkenylamines. 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 or more and 1.2% by mass or less, or 0.003% by mass or more and 1.2% by mass or less, or 0.005% by mass or more and 1.0% by mass or less, or 0.01% by mass or more and 0.3% by mass or less. By ensuring that the content is within this range, it is possible to improve the coatability of the resin composition on 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 to 14. When the amine compound contained in the surface treatment agent is an alkylamine, the pH is preferably 5.0 to 11.0, or 6.0 to 10.

[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, Good's buffer, and other 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, it is possible to easily adjust the contact angles of both surfaces to a desired range. Here, the desired range of contact angles means that the contact angles of both surfaces with dipropylene glycol are within a predetermined range. The desired range of contact angles means that the contact angles of the metal surface and the resin surface with dipropylene glycol are both 35° or more and 100° or less, or 36° or more and 95° or less, or 36° or more and 90° or less. When the contact angles of the metal surface and the resin surface with dipropylene glycol are both within the above ranges, the coating properties of the resin composition are not impaired and bleeding can be easily suppressed. More specifically, the contact angle of the metal surface with dipropylene glycol is 35° or more and 100° or less, or 36° or more and 95° or less, or 37° or more and 90° or less. 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 the present embodiment, the reason for evaluating the coatability of the 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 and spreadability, of a specific substance on the surface of a specific material, the contact angle of 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, since the measurement must be performed for each resin composition, there is a drawback in that 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] Meanwhile, 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, and a solvent. The surface treatment agent of this embodiment is preferably a solution in which the amine compound and other components are dissolved in water or other known solvents.

[0039] (Second embodiment: method for producing a film-forming substrate) The method for producing a film-formed substrate of this embodiment 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, and surface-treating the metal surface and the resin 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.

[0040] <Film forming base material> The film-formed substrate manufactured by the manufacturing 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-forming substrate include the same metals as those constituting the metal surface of the substrate in the first embodiment. Examples of the resin that constitutes the resin surface of the film-forming substrate include the same resins as those that constitute the resin surface of the substrate in the first embodiment. Both the metal and the resin are not 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 process> The manufacturing method of this embodiment may optionally include an etching step of etching the substrate surface with a microetchant prior to the surface treatment step.

[0044] The microetching agent used in the etching process is an etching agent that, when brought into contact with a metal surface, slightly etches the metal surface, forming 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 constituting 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 it, forming minute irregularities on the surface. The formation of such fine irregularities improves the adhesion between the metal surface and the resin composition. The treatment conditions in the etching step, ie, the treatment time, the temperature during treatment with the microetching agent, the treatment method such as spraying or immersion treatment, etc., can be adjusted as appropriate. In this embodiment, since a resin surface is also present on the surface of the substrate, the resin surface may also be brought into contact with the etching solution during the etching step, or a resist or the like may be provided on the resin surface to prevent it from coming into 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, preferably 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, 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 tends to improve the coatability. 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 weight in the etching step is preferably adjusted appropriately to achieve the above surface roughness, for example, from 0.5 μm to 2.0 μm, preferably from 0.7 μm to 1.5 μm. By setting the etching amount within the above range, it becomes easier to obtain 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 of the resin composition and the adhesion between the resin composition and both the metal surface and the resin surface.

[0050] <Surface treatment process> The manufacturing method of this embodiment includes a surface treatment step of contacting a surface of a substrate 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.

[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 the surface treatment agent that can be used in this embodiment include the surface treatment agent of the first embodiment described above, as well as solutions containing, as an active ingredient, an anionic surfactant, a nonionic surfactant, a cationic surfactant, an amphoteric surfactant solution, or the like. The active ingredients of the surface treatment agent may be used alone or in combination of two or more kinds. The surface treatment agent may contain, in addition to the above-mentioned active ingredients, 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 ingredient 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 may be 20°C or higher and 40°C or lower, preferably 25°C or higher and 35°C or lower. 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, but may be, for example, 10 seconds or more and 2 minutes or less, preferably 30 seconds or more and 1 minute or less.

[0055] The surface treatment is performed so that the contact angle of the metal surface and resin surface with dipropylene glycol after the surface treatment is 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 properties of the resin composition are not impaired, and adhesion is maintained, while bleeding can be easily suppressed. More specifically, the contact angle of the metal surface with dipropylene glycol is 35° or more and 100° or less, or 36° or more and 95° or less, or 37° or more and 70° or less. 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.

[0056] Furthermore, if a microetching step is carried out prior to the surface treatment step, the contact angle of the microetched metal surface with dipropylene glycol may be, 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 formation process> 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 the resin composition used in the film forming step of this embodiment include curable resin compositions that are cured by heating, ultraviolet light, light irradiation, etc., such as etching resist ink and solder resist ink. The etching resist ink and solder resist ink can be appropriately selected from known inks, but it is preferable that the viscosity of the ink is adjusted to a level that allows application by the inkjet method. For example, the etching resist ink is preferably a resin composition that is cured by ultraviolet light after application and can be peeled off with an alkaline aqueous solution, and specific examples include those containing a carboxyl group-containing monomer, a monofunctional monomer, a polyfunctional monomer, a photopolymerization initiator, and other optional components. The solder resist ink is preferably a resin composition that can be cured by heat, ultraviolet light, or light irradiation and that has heat resistance after curing.Specific examples include those that contain a curing agent such as an epoxy compound or an isocyanate compound and various optional components in addition to a combination of various monomers used in the etching resist ink.

[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, another processing 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 to plate the metal surface exposed through the openings in the solder resist. In this case, by carrying out 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-forming 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 bleeding of the resin composition and has high adhesion between the resin composition and the metal surface and the resin surface. The film-coated substrate of the present 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 metal surfaces, etc. In addition, the film-coated substrate can be used for, for example, various electronic and electrical devices, medical devices, vehicle-mounted devices, automobile parts, marine equipment parts, 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. [Example]

[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 board (manufactured by Aiko Kikai Seisakusho: 12 cm x 12 cm) having a copper plating layer with a thickness of 35 μm was prepared as a test substrate. Furthermore, one side of this test substrate was sprayed with an organic acid microetching agent (CZ series, manufactured by MEC Co., Ltd.) at a temperature of 25°C and a spray pressure of 0.1 MPa, and the etching time was adjusted so that the etching depth on one side of the test substrate was 1.0 μm. The surface that was washed with water was used as the treated surface, and the substrate was prepared as a microetched substrate. Furthermore, a copper clad laminate material for printed circuits (product name MCL-E-67, manufactured by Resonac) was cut to 12 cm x 12 cm to prepare a resin substrate with the resin surface (epoxy resin) as the treated surface.

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

[0070] <Contact angle measurement 1> The contact angles of the above surface-treated substrate with respect to dipropylene glycol, solder resist and distilled water were measured. The contact angle of each test substrate was measured by the sessile drop method described in JIS R3257 "Test method for wettability of substrate glass surface." The measuring 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 respect to the solder resist, solder resist (manufactured by Taiyo Ink Co., Ltd., product number IJSR-4000) was used instead of the distilled water described in the above JIS R3257. The results are shown in Table 1.

[0071] [Table 1]

[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 used as a comparative example, and could be adjusted to a range of 35° to 100°. For aminonanodecane and behenylamine, the contact angles sometimes fell outside this range at pH 12 or higher, but were within the above range by adjusting the pH to less than 10. Furthermore, when the contact angle measurements for dipropylene glycol and solder resist are compared, it is clear that there is a correlation when the same amine compound is used for treatment at the same pH. On the other hand, for the untreated substrate (comparison example), particularly for the resin substrate, no significant improvement in the contact angle with distilled water was observed 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 that were alkylamines and alkenylamines with different numbers of carbon atoms. The pH was adjusted to 10. The amine compounds used were as follows: Oleylamine (NOF Corporation, carbon number 18 / alkenylamine) Aminonanodecane (Tokyo Chemical Industry Co., Ltd., carbon number 19 / alkylamine) Behenylamine (NOF Corporation, carbon number 22 / alkylamine) Hexylamine (Tokyo Chemical Industry Co., Ltd., carbon number 6 / alkylamine) Octylamine (Kishida Chemical Co., Ltd., carbon number 8 / alkylamine) Dodecylamine (Kishida Chemical Co., Ltd., carbon number 12 / alkylamine) Tetradecylamine (Tokyo Chemical Industry Co., Ltd., carbon number 14 / alkylamine) The test substrates used were the same as the etching substrate and resin substrate used in Test 1 above. Each test substrate was subjected to a surface treatment 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] [Table 2]

[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 epoxy resin used in Tests 1 and 2 above, a polyimide resin plate (thickness 0.04 mm, size 40 mm × 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 above in the same manner as Test 1, and the contact angle with dipropylene glycol was measured. The results are shown in Table 3.

[0077] [Table 3]

[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] [Table 4]

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

[0082] "Test 5" <Measurement of bleeding width> The width of the solder resist bleeding was measured using the etching substrate and resin substrate used in Test 1 above. Each test substrate was treated with a solution of one of the amine compounds listed in Table 5 in the same manner as in Test 1. 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.) to a target line width of 100 μm. After application, the substrate was cured. If undissolved amine compound was visually observed after mixing, a commercially available dissolution aid was added to each amine compound solution. After curing, each test substrate was photographed using an optical microscope (device name: Digital Microscope VHS-5000, manufactured by KEYENCE Corporation). The line widths of five randomly selected points on the photograph were measured, and the average of the five points was calculated. As controls, the same measurements were also carried out on untreated substrates (etched substrate and resin substrate) that had not undergone any surface treatment. The results are shown in Table 6.

[0083] [Table 5]

[0084] [Table 6]

[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 a substrate surface, including a metal surface and a resin surface, comprising 0.001 mass % or more and 1.2 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. 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 surface treatment agent has a pH of 4.0 or more and 14 or less.

4. a surface treatment step of contacting a surface of a substrate 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; a film-forming step of forming a film of a resin composition on the surface of the surface-treated substrate by an inkjet method; A method for producing a film-formed substrate, comprising: producing a film-formed substrate having a film of a resin composition formed on the surface of the substrate;

5. 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 the film is formed by an inkjet method using a resin composition that is cured by heating, ultraviolet irradiation, or light irradiation in the film-forming step.

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

8. 8. The method for producing a film-formed substrate according to claim 7, wherein the etching step involves etching the metal surface 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 substrate surface having a metal surface and a resin surface; the contact angle of the metal surface and the resin surface with dipropylene glycol is 35° or more and 100° or less, A film-formed substrate having a film of a resin composition formed on the surface of the substrate, the metal surface having a surface roughness (Ra) of 0.1 μm or more and 0.8 μm or less.

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.

Images