JP2023121657A - Surface texture evaluation method, method of manufacturing metal members, method of manufacturing metal-resin joined bodies, and machine learning device - Google Patents

Abstract

To provide a novel surface texture evaluation method, a method of manufacturing metal members using the same, a method of manufacturing metal-resin joined bodies, and a machine learning device.SOLUTION: A surface texture evaluation method is provided, comprising providing a compound having an alkyl group with 1-20 carbon atoms on a surface of an object, and acquiring data on pores existing on the surface provided with the compound having the alkyl group with 1-20 carbon atoms, where the data is acquired by injecting water into the pores.SELECTED DRAWING: Figure 1

Description

The present invention relates to a surface texture evaluation method, a metal member manufacturing method, a metal-resin bonded body manufacturing method, and a machine learning apparatus.

As a method of roughening the surface of a metal member, a method of etching the surface of the metal member to form an uneven structure of micrometer order has been proposed (see, for example, Patent Document 1).

WO2015/008847

Parameters such as arithmetic average roughness (Ra) obtained using a surface roughness measuring device are widely used for quantitative evaluation of the surface properties of objects. However, when the surface of an object includes a fine uneven structure as described in Patent Literature 1, the existing methods may not be able to fully grasp the surface properties of the object.

In view of the above circumstances, an object of one embodiment of the present disclosure is to provide a novel method for evaluating surface properties, a method for manufacturing a metal member using this method, a method for manufacturing a metal-resin bonded body, and a machine learning device. do.

Means for solving the above problems include the following embodiments.
<1> A step of applying a compound having an alkyl group having 1 to 20 carbon atoms to the surface of an object;
a step of obtaining data on pores existing on the surface to which the compound having an alkyl group having 1 to 20 carbon atoms is applied;
A surface texture evaluation method, wherein the data is obtained by injecting water into the pores.
<2> The surface texture evaluation method according to <1>, wherein the compound having an alkyl group having 1 to 20 carbon atoms is chemically bonded to the surface of the object.
<3> The surface texture evaluation method according to <1> or <2>, wherein the compound having an alkyl group having 1 to 20 carbon atoms forms a self-assembled monolayer on the surface of the object.
<4> The surface properties according to any one of <1> to <3>, wherein the surface to which the compound having an alkyl group having 1 to 20 carbon atoms is applied has a water contact angle of 90° or more. Evaluation method.
<5> The surface texture evaluation method according to any one of <1> to <4>, wherein the object contains metal.
<6> Including a step of roughening the surface of the metal member,
A method for manufacturing a metal member, wherein the conditions for the roughening treatment are determined based on information obtained by the surface texture evaluation method according to any one of <1> to <5>.
<7> A step of roughening the surface of the metal member;
bonding a resin member to the roughened surface of the metal member,
A method for producing a metal-resin bonded body, wherein the conditions for the roughening treatment are determined based on information obtained by the surface property evaluation method according to any one of <1> to <5>.
<8> Information about the surface texture of the metal member obtained by the surface texture evaluation method according to any one of <1> to <5>; a learning unit that learns a function that determines the judgment value based on learning data composed of the judgment value;
The learning unit, based on the learning data, a reward calculation unit that calculates a reward for the result of determining the roughening treatment condition of the metal member or the bonding strength to the resin member using the function;
a function updating unit that updates the function so that the reward calculated by the reward calculating unit increases;
a convergence determination unit that repeats the calculation by the reward calculation unit and the update by the function update unit until a predetermined convergence condition is satisfied.

According to an embodiment of the present disclosure, a novel surface texture evaluation method, a method for manufacturing a metal member using this method, a method for manufacturing a metal-resin joined body, and a machine learning device are provided.

1 is a frequency distribution diagram of pore diameters of test pieces measured in Example 1. FIG. 1 is a frequency distribution diagram of pore diameters of test pieces measured in Example 1. FIG. 1 is a frequency distribution diagram of pore diameters of test pieces measured in Example 1. FIG. 1 is a frequency distribution diagram of pore diameters of test pieces measured in Example 1. FIG. 1 is a frequency distribution diagram of pore diameters of test pieces measured in Example 1. FIG. 1 is a schematic diagram showing an example of a configuration of a machine learning device 100; FIG. 4 is a conceptual diagram showing an example of a machine learning processing routine of the machine learning device 100; FIG.

In the present disclosure, a numerical range indicated using "to" indicates a range including the numerical values before and after "to" as the minimum and maximum values, respectively.
In the numerical ranges described in stages in the present disclosure, the upper or lower limit values described in a certain numerical range may be replaced with the upper or lower limits of other numerical ranges described in stages, and , may be replaced by the values shown in the examples.
In the present disclosure, when there are multiple substances corresponding to each component in the material, the amount of each component in the material means the total amount of the multiple substances present in the material unless otherwise specified.

<Method for evaluating surface texture>
The surface texture evaluation method of the present disclosure includes:
a step of applying a compound having an alkyl group having 1 to 20 carbon atoms to the surface of an object;
a step of obtaining data on pores existing on the surface to which the compound having an alkyl group having 1 to 20 carbon atoms is applied;
The data is obtained by injecting water into the pores, and is a method of evaluating surface properties.

According to the above method, the surface properties of an object can be accurately evaluated even when the surface of the object contains pores.

In the above method, pore data is obtained by injecting water into the pores on the surface of the object. Hereinafter, a method of obtaining pore data by injecting water into pores on the surface of an object is also referred to as a "water injection method".

In the water injection method, water is injected into the pores on the surface of the object while pressurizing it, and based on the relationship between the applied pressure and the amount of water injected into the pores, the number of pores existing on the surface of the object is reduced. Get data.

The pressure P applied to the object and the diameter D of the pore into which water is injected are inversely proportional, as shown by the following Washburn equation. By determining the injection amount of water while changing the pressure applied to the object stepwise, the abundance for each pore diameter can be determined.

D=-4σ cos θ/P
where D is the diameter of the pore, σ is the surface tension of water, θ is the contact angle of water, and P is the pressure.

Pore data used in the methods of the present disclosure include pore size distribution, average pore size, total pore volume, and the like.

The mercury intrusion method, which has the same principle as the water intrusion method, injects mercury into pores to obtain pore data. Therefore, when the material of the object reacts with mercury such as aluminum alloy, the mercury intrusion method cannot be applied.
The method of the present disclosure allows pore data to be obtained even if the material of the object reacts with mercury. In addition, since mercury is a substance whose release into the environment is restricted, the method of the present disclosure, which uses water instead of mercury, is also excellent in terms of compatibility with living organisms and the environment.

In the method of the present disclosure, a compound having an alkyl group having 1 to 20 carbon atoms is applied to the surface of the object prior to obtaining data on pores on the surface of the object.
In order to accurately obtain pore data by the water injection method, the wettability of water to the surface of the object must be small (that is, the object must be hydrophobic).
By applying a compound having an alkyl group having 1 to 20 carbon atoms to the surface of an object, the surface of the object is hydrophobized. As a result, it is possible to obtain the data of the pores on the surface of the object with high accuracy.

In the compound having an alkyl group having 1 to 20 carbon atoms, the number of carbon atoms in the alkyl group of the compound is not particularly limited as long as it is within the range of 1 to 20 carbon atoms. The number of carbon atoms in the alkyl group may be 3 or more, 5 or more, 10 or more, or 15 or more.
The alkyl group having 1 to 20 carbon atoms may be unsubstituted or substituted, and is preferably unsubstituted.
The alkyl group having 1 to 20 carbon atoms may be linear or branched, preferably linear.
The number of alkyl groups in the compound having an alkyl group of 1 to 20 carbon atoms may be one or two or more, preferably one.

From the viewpoint of effectively hydrophobizing the surface of an object, the compound having an alkyl group of 1 to 20 carbon atoms is preferably a compound that chemically bonds with the surface of the object.

The type of compound having an alkyl group of 1 to 20 carbon atoms that chemically bonds with the surface of the object is not particularly limited, and can be selected according to the material of the surface of the object. For example, when a hydroxyl group exists on the surface of the object, a compound having an alkyl group having 1 to 20 carbon atoms and a functional group that reacts with the hydroxyl group can be selected.

Specific examples of compounds having an alkyl group of 1 to 20 carbon atoms chemically bonded to the surface of an object include phosphonic acid compounds having an alkyl group of 1 to 20 carbon atoms, and alkyl groups of 1 to 20 carbon atoms. Examples include silane compounds, carboxylic acid derivatives, fluorocarbons, thiol derivatives, and the like.

From the viewpoint of measurement accuracy, the compound having an alkyl group having 1 to 20 carbon atoms is preferably capable of forming a self-assembled monolayer on the surface of an object.

A self-assembled monolayer has a thickness of about 1 to 2 nanometers, which is extremely thin. Therefore, the presence of a film formed inside the pores by a compound having an alkyl group of 1 to 20 carbon atoms has little effect on the measurement results.

Specific examples of the compound having an alkyl group having 1 to 20 carbon atoms capable of forming a self-assembled monolayer on the surface of an object include a phosphonic acid compound having an alkyl group having 1 to 20 carbon atoms and a phosphonic acid compound having 1 to 20 carbon atoms. A silane compound having an alkyl group of , and a phosphonic acid compound having an alkyl group having 1 to 20 carbon atoms is preferable from the viewpoint of the stability of the formed self-assembled monolayer.

A phosphonic acid compound forms a self-assembled monolayer with a higher density than a silane compound. For example, a silane compound reacts only with hydroxyl groups (OH) present on the surface of an object, whereas a phosphonic acid compound regenerates OH by supplying protons (H ⁺ ) to the surface of the object, resulting in a chain reaction. This is thought to be due to the reaction to Therefore, it is considered that a film formed using a phosphonic acid compound having an alkyl group having 1 to 20 carbon atoms has excellent stability.

There are no particular restrictions on the method of applying the compound having an alkyl group having 1 to 20 carbon atoms to the surface of the object. Specific examples of the application method include a method of applying a liquid in which a compound having an alkyl group of 1 to 20 carbon atoms is dissolved or dispersed on the surface of an object, a method of immersing the object in the liquid, and the like.

Heat treatment may be performed after applying the compound having an alkyl group having 1 to 20 carbon atoms to the surface of the object. By performing heat treatment, for example, chemical bonding between a compound having an alkyl group having 1 to 20 carbon atoms and the surface of an object can be promoted.

The surface of the object to which the compound having an alkyl group having 1 to 20 carbon atoms is applied has a water contact angle of preferably 90° or more, more preferably 110° or more, and 130° or more. is more preferred.

When the contact angle of water on the surface of the object is 90° or more, it can be determined that the surface of the object is sufficiently hydrophobized, and the pore diameter can be accurately measured by the water injection method.

After applying a compound having an alkyl group having 1 to 20 carbon atoms to the surface of the object, data on the pores on the surface of the object is obtained by a water injection method.
The method for acquiring pore data by the water injection method is not particularly limited, and is carried out according to known procedures. For example, it is carried out by injecting water instead of mercury into the pores using a mercury porosimeter used in the mercury intrusion method.
The water used to obtain pore data by the water injection method may be pure water such as ion-exchanged water, or water containing impurities within a range in which the required contact angle can be obtained.

The type of object to be measured by the method of the present disclosure is not particularly limited. In the method of the present disclosure, the surface of an object is hydrophobized by applying a compound having an alkyl group having 1 to 20 carbon atoms to the surface of the object. Therefore, the method of the present disclosure can be applied even to an object having a hydrophilic surface. For example, the method of the present disclosure can be applied even if the object contains metal.

<Manufacturing method of metal member>
A method for manufacturing a metal member of the present disclosure includes a step of roughening the surface of the metal member,
In the method for manufacturing a metal member, the conditions for the roughening treatment are determined based on the information obtained by the above-described method for evaluating surface properties.

In the above method, the conditions for the roughening treatment of the surface of the metal member are determined based on the information obtained by the above-described surface texture evaluation method. Therefore, information that cannot be grasped by parameters such as arithmetic mean roughness (Ra), which is widely used to evaluate the surface properties of metal members, can be accurately reflected in the roughening treatment conditions.

In the above method, the conditions for the roughening treatment of the metal member are determined based on the information obtained by the above-described surface texture evaluation method. The information obtained by the evaluation method of the surface properties includes the pore size distribution, average pore size, total pore volume, etc. of pores existing on the surface of the metal member. These pieces of information are used, for example, as indicators of the bonding strength of the metal member to the resin member.

The material of the metal member is not particularly limited. Specifically, the material of the metal member is a metal selected from iron, copper, nickel, gold, silver, platinum, cobalt, zinc, lead, tin, titanium, chromium, aluminum, magnesium and manganese, and selected from the above metals and alloys containing at least one of

The material of the metal member may be of one type or two or more types.
The metal member may have a main body and a plating layer formed on the surface of the main body.

As a method for roughening treatment of metal members, a method using a laser as disclosed in Japanese Patent No. 4020957 _; A method of immersion; a method of treating the surface of a metal member by anodization, as disclosed in Japanese Patent No. 4541153; an acid-based etchant (preferably, , inorganic acids, ferric ions or cupric ions) and, if necessary, an acidic etchant aqueous solution containing manganese ions, aluminum chloride hexahydrate, sodium chloride, etc.; A method of immersing the surface of a metal member in an aqueous solution of one or more selected from hydrazine hydrate, ammonia, and water-soluble amine compounds as disclosed in 2009/31632 (NMT method); Hot water treatment as disclosed in JP-A-2003-200030; and roughening treatment such as blasting.

The roughening treatment of the metal member may be to form a porous plated layer on the surface of the metal member as described in Japanese Patent No. 5366076.

Among the above methods, treatment with an acid-based etchant is preferable from the viewpoint of increasing the bonding strength of the metal member to the resin member.
The treatment with an acid-based etchant includes, for example, a method of performing the following steps (1) to (4) in this order.

(1) Pretreatment Step A pretreatment is performed to remove oxide films, hydroxide films, and the like present on the surface of the metal member. A mechanical polishing or chemical polishing process is usually performed. If the surface of the metal member is significantly contaminated with machine oil or the like, it may be treated with an alkaline aqueous solution such as an aqueous sodium hydroxide solution or an aqueous potassium hydroxide solution, or degreased.

(2) Treatment step with zinc ion- ^{containing alkaline} aqueous solution The treated metal member is immersed to form a zinc-containing coating on the surface. M in MOH is an alkali metal or an alkaline earth metal.

(3) Treatment step with an acid-based etchant After step (2), the metal member is treated with an acid-based etchant containing at least one of ferric ions and cupric ions and an acid to remove the metal member. The zinc-containing coating on the surface is eluted, and micrometer-order fine irregularities are formed.

(4) Post-treatment process After the above process (3), the metal member is washed. It usually consists of washing and drying operations. An ultrasonic cleaning operation may be included for desmutting.

The roughening treatment of the metal member may be performed twice or more. For example, the above steps (1) to (4) are performed to form a micrometer-order uneven structure (base rough surface) on the surface of the metal member, and then a nanometer-order uneven structure (fine rough surface) is formed. You may

As a method of forming a fine rough surface after forming a base rough surface on the surface of a metal member, for example, the metal member on which the base rough surface is formed is subjected to a standard electrode potential E ⁰ exceeding −0.2 at 25° C. and 0.0. A method of contacting with an oxidizing acidic aqueous solution containing 8 or less, preferably more than 0 and 0.5 or less metal cations can be mentioned.
The oxidizing acidic aqueous solution preferably does not contain a metal cation having E ⁰ of -0.2 or less.
Metal cations having a standard electrode potential E ⁰ of more than −0.2 and less than or equal to 0.8 at 25° C. include Pb ²⁺ , Sn ²⁺ , Ag ⁺ , Hg ²⁺ , Cu ²⁺ and the like. Among these, Cu ²⁺ is preferable from the viewpoint of metal scarcity and the safety and toxicity of the corresponding metal salt.
Compounds that generate Cu ²⁺ include inorganic compounds such as copper hydroxide, cupric oxide, cupric chloride, cupric bromide, copper sulfate, and copper nitrate. Copper oxide is preferable from the viewpoint of the efficiency of imparting a thin layer.

Examples of the oxidizing acidic aqueous solution include nitric acid and a mixture of nitric acid with hydrochloric acid, hydrofluoric acid, or sulfuric acid. Further, an aqueous solution of percarboxylic acid represented by peracetic acid and performic acid may be used. When nitric acid is used as the oxidizing acidic aqueous solution and cupric oxide is used as the metal cation-generating compound, the concentration of nitric acid constituting the aqueous solution is, for example, 10% by mass to 40% by mass, preferably 15% by mass to 38% by mass, and more. It is preferably 20% by mass to 35% by mass. The concentration of copper ions constituting the aqueous solution is, for example, 1% to 15% by mass, preferably 2% to 12% by mass, more preferably 2% to 8% by mass.

The temperature at which the metal member on which the base rough surface is formed is brought into contact with the oxidizing acidic aqueous solution is not particularly limited. A treatment temperature of 30° C. to 50° C. is preferably employed. The treatment time at this time is, for example, in the range of 1 minute to 15 minutes, preferably 2 minutes to 10 minutes.

Applications of the metal member are not particularly limited. For example, in addition to a metal-resin bonded body to be described later, an antibacterial member and the like can be used.

<Manufacturing method of metal-resin joined body>
The method for manufacturing a metal-resin bonded body of the present disclosure includes:
A step of roughening the surface of the metal member;
bonding a resin member to the roughened surface of the metal member,
In the method for producing a metal-resin bonded body, the conditions for the roughening treatment are determined based on the information obtained by the above-described method for evaluating surface properties.

In the present disclosure, the state in which the metal member and the resin member are "joined" means the state in which the metal member is fixed to the resin member without using an adhesive, screws, or the like.

The state in which the metal member is joined to the resin member can be formed, for example, by applying the material of the resin member in a state of fluidity due to melting or softening to the roughened surface of the metal member. When the material of the resin member is in a fluid state, the material of the resin member penetrates into the uneven structure of the roughened surface of the metal member to exhibit an anchor effect, and the resin member firmly adheres to the surface of the metal member. Join.

In the above method, the conditions for the roughening treatment of the metal member are determined based on the information obtained by the above-described surface property evaluation method. Information obtained by the evaluation method of surface properties includes the pore size distribution, average pore size, total pore volume, etc. of pores present on the surface of the metal member. These pieces of information are used, for example, as indicators of the bonding strength of the metal member to the resin member.

The type of resin contained in the resin member is not particularly limited, and may be thermoplastic resin, thermosetting resin, thermoplastic elastomer, thermosetting elastomer, or the like.
Thermoplastic resins include polyethylene (PE), polypropylene (PP), polystyrene (PS), acrylonitrile/styrene resin (AS), acrylonitrile/butadiene/styrene resin (ABS), methacrylic resin (PMMA), polyvinyl chloride (PVC ), polyamide (PA), polyacetal (POM), ultra-high molecular weight polyethylene (UHPE), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polymethylpentene (TPX), polycarbonate (PC), modified polyphenylene ether (PPE ), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), liquid crystal resin (LCP), polytetrafluoroethylene (PTFE), polyetherimide (PEI), polyarylate (PAR), polysulfone (PSF), poly Ethersulfone (PES), polyamideimide (PAI), and the like can be mentioned.
Thermosetting resins include phenol resins, urea resins, melamine resins, unsaturated polyesters, alkyd resins, epoxy resins, diallyl phthalate, and the like.
Examples of thermoplastic elastomers include styrene-based thermoplastic elastomers, polyester-based thermoplastic elastomers, urethane-based thermoplastic elastomers, amide-based thermoplastic elastomers, and the like.
Thermosetting elastomers include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), chloroprene rubber (CR), acrylonitrile-butadiene copolymer rubber ( NBR) and other diene rubbers, butyl rubber (IIR), ethylene-propylene rubber (EPM), urethane rubber, silicone rubber, acrylic rubber and other non-diene rubbers.
The resin contained in the resin member may be in the form of ionomer or polymer alloy.
The resin contained in the resin member may be of one type or two or more types.

The resin member may contain various compounding agents in addition to the resin. Compounding agents include fillers such as glass fibers, carbon fibers, inorganic powders, heat stabilizers, antioxidants, pigments, weathering agents, flame retardants, plasticizers, dispersants, lubricants, release agents, antistatic agents, etc. is mentioned.

When the resin member contains a component other than the resin, the proportion of the resin in the entire resin member is preferably 10% by mass or more, more preferably 20% by mass or more, and further preferably 30% by mass or more. preferable.

The step of joining the resin member to the roughened surface of the metal member can be performed by a known method such as injection molding.

<Machine learning device>
The machine learning device of the present disclosure includes: information on the surface texture of the metal member obtained by the above-described surface texture evaluation method; and a roughening treatment condition of the metal member or a determination value regarding the bonding strength to the resin member. a learning unit that learns a function that determines the judgment value based on learning data;
The learning unit, based on the learning data, a reward calculation unit that calculates a reward for the result of determining the roughening treatment condition of the metal member or the bonding strength to the resin member using the function;
a function updating unit that updates the function so that the reward calculated by the reward calculating unit increases;
and a convergence determination unit that repeats the calculation by the reward calculation unit and the update by the function update unit until a predetermined convergence condition is satisfied.

The machine learning device can be used, for example, to optimize roughening treatment conditions for metal members and to predict the bonding strength of roughened metal members to resin members.

The machine learning device of the present disclosure may further include a determination unit that determines the determination value using the function learned by the learning unit from the input information about the surface texture of the metal member.

FIG. 6 is a schematic diagram showing an example of the configuration of the machine learning device 100. As shown in FIG. The machine learning device 100 having the configuration shown in FIG. 6 can be configured by a computer including a CPU, a RAM, and a ROM storing programs and various data for executing a machine learning processing routine, which will be described later. The machine learning device 100 includes an input section 10 , a computing section 20 and an output section 90 .

The input unit 10 receives a plurality of pieces of learning data composed of information on the surface texture of the metal member and judgment values on the roughening treatment condition of the metal member or the bonding strength to the resin member. The input unit 10 also receives information about the surface texture of the metal member, which is the object of determination.

The calculation unit 20 includes a learning data storage unit 30 , a learning unit 40 , a trained model storage unit 50 and a determination unit 60 .

A plurality of learning data received by the input unit 10 are stored in the learning data storage unit 30 .
A learning unit 40 learns a function for determining a judgment value based on a plurality of pieces of learning data.
Specifically, the learning unit 40 includes a reward calculation unit 42 , a function update unit 44 and a convergence determination unit 46 .
The reward calculation unit 42 calculates a reward for the result of determining the joint strength of the metal member to the resin member using a function based on each of the plurality of learning data.
The function updating unit 44 updates the function based on the reward calculated for each of the plurality of learning data by the reward calculating unit 42 so as to increase the reward.
The convergence determination unit 46 causes the calculation by the reward calculation unit 42 and the update by the function update unit 44 to be repeated until a predetermined convergence condition is satisfied.
The learned model storage unit 50 stores functions learned by the learning unit 40 .
The determination unit 60 uses the function learned by the learning unit 40 from the information about the surface texture of the metal member input as the determination target, and determines the roughening treatment condition of the metal member or the determination value regarding the bonding strength to the resin member. decide.

Each component of the machine learning device of this embodiment is not particularly limited, and may be each component of a known machine learning device.

FIG. 7 is a conceptual diagram showing an example of a machine learning processing routine of the machine learning device 100. As shown in FIG.
When the input unit 10 receives multiple learning data, the machine learning device 100 stores the multiple learning data in the learning data storage unit 30 . Then, the machine learning device 100 executes the machine learning processing routine shown in FIG.

First, in step S100, for each of a plurality of learning data, based on the learning data, a reward for the result of determining the state of the surface texture of the object using the current function is calculated.
In step S102, the function is updated so as to increase the reward based on the reward calculated for each of the plurality of learning data in step S100.
A step S104 determines whether or not a predetermined convergence condition is satisfied, and if the convergence condition is not satisfied, the process returns to step S100. On the other hand, when the convergence condition is satisfied, the process proceeds to step S106.
In step S106, the finally updated function is stored in the learned model storage unit 50, and the learning processing routine ends.
When the input unit 10 receives the information about the surface texture of the metal member input as the determination target, the determination unit 60 of the machine learning device 100 uses the information about the surface texture of the metal member input as the determination target to determine whether the learning unit 40 Using the function learned by , a determination value regarding the roughening treatment condition of the metal member or the bonding strength to the resin member is determined and output by the output unit 90 .

Hereinafter, embodiments according to the present disclosure will be described with reference to examples. The present disclosure is by no means limited to the description of these examples.

<Example 1>
(1) Preparation of Test Specimen On the surface of a plate (20 cm×20 cm×0.03 cm) made of aluminum alloy (A5052), an acid etchant was used to form a micrometer-order concave-convex structure.
When the surface of the aluminum alloy plate subjected to the above treatment was observed with an electron microscope, a large number of pores (recesses) having a pore diameter of about 0.1 μm to 10 μm were formed.

The roughened aluminum alloy plate was immersed in an ethanol solution of n-octadecylphosphonic acid (5 mmol/L) for 20 seconds. After that, the aluminum alloy plate was washed with ethanol and dried at 80° C. for 20 minutes to obtain a test piece.

Ion-exchanged water (2 μL) was dropped on the surface of the test piece, and the contact angle was measured 1 minute after dropping. The measurement was performed under the conditions of 24° C. and 31% relative humidity. The contact angle calculated by the tangent method from the image of the water droplet taken with a digital camera was 140°.

(2) Measurement of Pore Size The test piece prepared in (1) above was subjected to vacuum degassing at 25° C. for 10 minutes. Then, the test piece was divided into 16 sheets by dividing each into 4 equal parts lengthwise and widthwise. All 16 divided sheets are put in a mercury porosimeter, and in accordance with the mercury intrusion method (JIS R 1655-2003), the measurement temperature is 25 ° C., the surface tension of ion-exchanged water is 72 mN / m, and the contact angle of ion-exchanged water is 140 °. A volume-based frequency distribution map of pore diameters was obtained by injecting ion-exchanged water under the conditions. The results are shown in FIG. The horizontal axis in the figure indicates the pore diameter (μm), and the vertical axis indicates the number (%) of pores per diameter.

<Example 2>
A frequency distribution map of pore diameters was obtained in the same manner as in Example 1, except that the roughened aluminum alloy plate was immersed in an ethanol solution of n-octadecylphosphonic acid (5 mmol/L) for 7 hours. The results are shown in FIG.

<Example 3>
A pore size frequency distribution map was obtained in the same manner as in Example 1, except that the roughened aluminum alloy plate was immersed in an ethanol solution of n-octadecylphosphonic acid (5 mmol/L) for 16 hours. The results are shown in FIG.

<Example 4>
A pore size frequency distribution map was obtained in the same manner as in Example 1, except that the roughened aluminum alloy plate was immersed in an ethanol solution of n-octadecylphosphonic acid (5 mmol/L) for 50 hours. The results are shown in FIG.

<Example 5>
Same as Example 1, except that the material of the aluminum alloy plate was changed to an aluminum alloy (A1050), and the roughened aluminum alloy plate was immersed in an ethanol solution of n-octadecylphosphonic acid (5 mmol/L) for 50 hours. Then, a frequency distribution map of pore diameters was obtained. The results are shown in FIG.

As shown in FIGS. 1 to 5, the pore data obtained by the method of the present disclosure generally agreed with the state of the surface of the test piece observed in the electron microscope image.
As described above, according to the method of the present disclosure, it was found that even if the surface of an object contains pores, the surface properties of the object can be accurately evaluated.

Claims (8)

a step of applying a compound having an alkyl group having 1 to 20 carbon atoms to the surface of an object;
a step of obtaining data on pores existing on the surface to which the compound having an alkyl group having 1 to 20 carbon atoms is applied;
A surface texture evaluation method, wherein the data is obtained by injecting water into the pores. 2. The surface texture evaluation method according to claim 1, wherein said compound having an alkyl group having 1 to 20 carbon atoms is chemically bonded to the surface of said object. 3. The surface texture evaluation method according to claim 1, wherein the compound having an alkyl group having 1 to 20 carbon atoms forms a self-assembled monolayer on the surface of the object. The surface property evaluation method according to any one of claims 1 to 3, wherein the surface provided with the compound having an alkyl group having 1 to 20 carbon atoms has a water contact angle of 90° or more. The surface texture evaluation method according to any one of claims 1 to 4, wherein the object includes metal. Including a step of roughening the surface of the metal member,
A method for manufacturing a metal member, wherein the conditions for the roughening treatment are determined based on information obtained by the surface texture evaluation method according to any one of claims 1 to 5. A step of roughening the surface of the metal member;
bonding a resin member to the roughened surface of the metal member,
A method for producing a metal-resin bonded body, wherein the conditions for the roughening treatment are determined based on information obtained by the surface texture evaluation method according to any one of claims 1 to 5. Information about the surface texture of the metal member obtained by the surface texture evaluation method according to any one of claims 1 to 5; roughening treatment conditions of the metal member or a judgment value about bonding strength to the resin member; a learning unit that learns a function that determines the judgment value based on learning data consisting of;
The learning unit, based on the learning data, a reward calculation unit that calculates a reward for the result of determining the roughening treatment condition of the metal member or the bonding strength to the resin member using the function;
a function updating unit that updates the function so that the reward calculated by the reward calculating unit increases;
a convergence determination unit that repeats the calculation by the reward calculation unit and the update by the function update unit until a predetermined convergence condition is satisfied.