WO2024034544A1

WO2024034544A1 - Structural body and method for producing structural body

Info

Publication number: WO2024034544A1
Application number: PCT/JP2023/028643
Authority: WO
Inventors: 和樹木村; 啓介宍戸; 太一大久保; 翔太新蔵
Original assignee: 三井化学株式会社
Priority date: 2022-08-10
Filing date: 2023-08-04
Publication date: 2024-02-15

Abstract

A structural body comprising: a metallic member having a surface in which at least one fine structure selected from among dendritic structures, acicular structures, and particular structures has been formed; and a resinous member bonded to the surface of the metallic member in which the fine structure has been formed. The resinous member has a tensile modulus at 23°C of 500 MPa or less or includes a heat-curable elastomer.

Description

Structure and method for manufacturing the structure

The present disclosure relates to a structure and a method for manufacturing the structure.

As a method for manufacturing a structure consisting of a metal member and a rubber member made of a thermosetting elastomer, various methods are known, such as a method of vulcanizing unvulcanized rubber while the metal member is in contact with the unvulcanized rubber. It is being These methods generally require complicated work processes such as surface treatment of metal parts and application of adhesive to improve adhesion to rubber parts, and there is room for improvement in terms of production efficiency. .
As a method for directly bonding a metal member and a rubber member without using an adhesive, for example, Patent Document 1 describes an ethylene/α-olefin copolymer having an ethylene unit and an α-olefin unit having 3 or more carbon atoms. It has been proposed to use a rubber composition containing a sulfur-containing silane coupling agent, and a sulfur-containing vulcanizing agent.

Patent Document 1: International Publication No. 2018/212180

In the method described in Patent Document 1, a silane coupling agent containing a sulfur atom is blended into a rubber composition to increase adhesive strength to metal members, but its use is limited to cases where a specific type of elastomer is used. Limited. Therefore, there is a need for a method for producing a composite that exhibits excellent adhesion to metal members regardless of the type of elastomer.

In view of the above circumstances, an object of an embodiment of the present disclosure is to provide a structure with excellent versatility in the materials used, and a method for manufacturing the same.

Means for solving the above problems include the following embodiments.
<1> A metal member having a surface on which at least one microstructure selected from a dendritic structure, a needle-like structure, and a particulate structure is formed;
a resin member bonded to the surface of the metal member on which the fine structure is formed;
The resin member is a structure having a tensile modulus of elasticity of 500 MPa or less at 23°C.
<2> A metal member having a surface on which at least one or more microstructures selected from a dendritic structure, a needle-like structure, and a particulate structure are formed;
a resin member bonded to the surface of the metal member on which the fine structure is formed;
A structure in which the resin member includes a thermosetting elastomer.
<3> The structure according to <1> or <2>, wherein the fine structure has an average thickness of 1 nm to 1000 nm.
<4> The structure according to any one of <1> to <3>, wherein the surface has an average ten-point roughness (Rzjis) of 2 μm to 100 μm.
<5> The structure according to any one of <1> to <4>, wherein the average value of the average length (RSm) of the surface roughness curve element is 10 μm to 500 μm.
<6> _The absorbance A ₁ of the absorption peak at 3400 ^cm ⁻¹ observed by Fourier transform infrared spectroscopy of the surface, and the absorbance A 0 at 3400 cm ⁻¹ of the straight line connecting the absorbance at 3800 cm −1 and the absorbance at 2500 cm ⁻¹ The structure according to any one of <1> to <5>, wherein the difference (A ₁ - A ₀ ) between the structure and the structure is 0.03 or less.
<7> The structure according to claim 1, wherein the resin member includes a thermosetting elastomer or a thermoplastic elastomer.
<8> A step of preparing a metal member having a surface on which at least one microstructure selected from a dendritic structure, an acicular structure, and a particulate structure is formed;
The method according to any one of <1> to <7>, comprising the step of applying heat and pressure to the resin member while the resin member is in contact with the surface on which the fine structure of the metal member is formed. Method of manufacturing the structure.

According to one embodiment of the present disclosure, a structure with excellent versatility in the materials used and a method for manufacturing the same are provided.

It is a cross-sectional SEM image of a sample produced in an example. 2 is a partially enlarged image of the cross-sectional SEM image shown in FIG. 1.

In the present disclosure, a numerical range indicated using "~" indicates a range that includes the numerical values written before and after "~" as the minimum value and maximum value, respectively.
In the numerical ranges described step by step in this disclosure, the upper or lower limit stated in one numerical range may be replaced by the upper or lower limit of another numerical range described step by step, and , may be replaced with the values shown in the examples.
In the present disclosure, if 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.

<Structure>
(First embodiment)
A first embodiment of the structure of the present disclosure includes:
A metal member having a surface on which at least one or more microstructures selected from a dendritic structure, a needle-like structure, and a particulate structure are formed;
a resin member bonded to the surface of the metal member on which the fine structure is formed;
The resin member is a structure having a tensile modulus of elasticity of 500 MPa or less at 23°C.

The structure of this embodiment includes a relatively soft resin member having a tensile modulus of 500 MPa or less at 23°C.
Furthermore, in the structure of this embodiment, at least one fine structure selected from a dendritic structure, a needle-like structure, and a particulate structure is formed on the surface of the metal member that is bonded to the resin member.
As a result of the inventors' studies, when a fine structure is formed on the surface of a metal member that is bonded to a resin member, compared to a case where a fine structure is not formed on the surface of a metal member that is bonded to a resin member, It was found that the bonding strength between the resin member and the metal member was significantly improved. The reason for this is, for example, that a resin member with a tensile modulus of elasticity of 500 MPa or less at 23°C enters the gaps in the microstructure of the surface of a metal member, and if it is adsorbed at the molecular chain level, the resin member and metal member will be separated. It is conceivable that a sufficient microscopic contact area is ensured, making it difficult for the resin member to separate from the metal member.

(Second embodiment)
A second embodiment of the structure of the present disclosure includes:
A metal member having a surface on which at least one microstructure selected from a dendritic structure, a needle-like structure, and a particulate structure is formed;
a resin member bonded to the surface of the metal member on which the fine structure is formed;
The resin member is a structure containing a thermosetting elastomer.

In the structure of this embodiment, the resin member includes a thermosetting elastomer.
Furthermore, in the structure of this embodiment, at least one fine structure selected from a dendritic structure, a needle-like structure, and a particulate structure is formed on the surface of the metal member that is bonded to the resin member.
As a result of the inventors' studies, when a fine structure is formed on the surface of a metal member that is bonded to a resin member, compared to a case where a fine structure is not formed on the surface of a metal member that is bonded to a resin member, It was found that the bonding strength between the resin member and the metal member was significantly improved. The reason for this is, for example, that if the thermosetting elastomer contained in the resin member enters the gaps in the microstructure of the surface of the metal member and is adsorbed at the molecular chain level, the microscopic bonding between the resin member and the metal member may occur. It is conceivable that a sufficient contact area is ensured, making it difficult for the resin member to separate from the metal member.

The structure of the present disclosure achieves excellent bonding strength with the resin member by forming a fine structure on the surface of the metal member. Therefore, there is a wide selection range of materials for the metal members and resin members to be used, and the device has excellent versatility.
Furthermore, in the structure of this embodiment, the resin member is joined to the metal member without using an adhesive or the like. Therefore, processes such as applying adhesive can be omitted, resulting in excellent productivity.

(metal parts)
The material of the metal member included in the structure is not particularly limited as long as a fine structure can be formed on the surface. 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 a metal selected from the above metals. Examples include alloys containing at least one of the following.

The metal member may have a main body and a plating layer formed on the surface of the main body. In this case, a fine structure may be formed on the surface of the plating layer.

The structure is at least one selected from a dendritic structure, a needle-like structure, and a particulate structure formed on the surface of the metal member.
The fine structure may consist only of a needle-like structure, a dendritic structure, or a particulate structure, or may be a mixture of two or more of these structures. Alternatively, fine structures other than these may be included.
The microstructure may include an oxide of a metal component contained in the metal member. For example, if the metal member includes aluminum, the microstructure may include aluminum oxide.

(1) Dendritic structure In the present disclosure, a "dendritic structure" refers to a structure in which fine irregularities are formed on the surface of the metal member by branched protrusions that allow the resin constituting the resin member to enter the surface of the metal member. means a structure in a state of
The branched protrusions include, for example, a trunk rising from the surface of the metal member (main trunk), a branch branching from the main trunk (main branch), a branch branching from the main branch (side branch), and the like.

The average number density of the protrusions constituting the dendritic structure is preferably 3 protrusions/μm or more, more preferably 5 protrusions/μm or more, and even more preferably 10 protrusions/μm or more.
The average number density of the protrusions constituting the dendritic structure is preferably 100 protrusions/μm or less, more preferably 80 protrusions/μm or less, and even more preferably 60 protrusions/μm or less.
When the average number density of the protrusions constituting the dendritic structure is within the above range, the interval between the protrusions is adjusted to the optimum interval for entry of the resin contained in the resin member.

The average height of the protrusions constituting the dendritic structure is preferably 1 nm to 1000 nm, more preferably 30 nm to 900 nm, and even more preferably 50 nm to 800 nm.
When the average height of the protrusions constituting the dendritic structure is within the above range, the height of the protrusions is adjusted to an optimal height for the resin contained in the resin member to enter.

The average number density and average height of the protrusions constituting the dendritic structure are calculated from the cross-sectional profile of the metal member taken by a scanning electron microscope (SEM). Specifically, it is an arithmetic mean value of values measured at ten arbitrary points.

The method of forming the dendritic structure on the surface of the metal member is not particularly limited.
For example, a method of contacting a metal member with an oxidizing acidic aqueous solution containing a metal cation having a standard electrode potential E ⁰ at 25° C. of more than −0.2 and less than 0.8, preferably more than 0 and less than 0.5 can be mentioned.
It is preferable that the oxidizing acidic aqueous solution does not contain a metal cation with E ⁰ of -0.2 or less.
Examples of metal cations whose standard electrode potential E ⁰ at 25° C. is more than −0.2 and less than 0.8 include Pb ²⁺ , Sn ²⁺ , Ag ⁺ , Hg ²⁺ , Cu ²⁺ and the like. Among these, Cu ²⁺ is preferable from the viewpoint of the rarity of the metal 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 forming a layer.

Examples of the oxidizing acidic aqueous solution include nitric acid or an acid obtained by mixing nitric acid with any one of hydrochloric acid, hydrofluoric acid, and sulfuric acid. Furthermore, an aqueous percarboxylic acid solution such as 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 nitric acid concentration constituting the aqueous solution is, for example, 10% by mass to 40% by mass, preferably 15% to 38% by mass, or more. Preferably it is 20% by mass to 35% by mass. Further, the concentration of copper ions constituting the aqueous solution is, for example, 1% by mass to 15% by mass, preferably 2% by mass to 12% by mass, and more preferably 2% by mass to 8% by mass.

The temperature at which the metal member is brought into contact with the oxidizing acidic aqueous solution is not particularly limited, but in order to complete the roughening at an economical speed while controlling the exothermic reaction, the temperature is, for example, room temperature to 60°C, preferably 30°C to 50°C. A processing temperature of °C is adopted. The treatment time at this time is, for example, in the range of 1 minute to 15 minutes, preferably 2 minutes to 10 minutes.

(2) Acicular structure In the present disclosure, the term "acicular structure" refers to fine irregularities that allow the resin constituting the resin member to enter the surface of the metal member due to unbranched protrusions on the surface of the metal member. It means a structure in a formed state.

The average number density of the protrusions constituting the needle-like structure is preferably 3 protrusions/μm or more, more preferably 5 protrusions/μm or more, and even more preferably 10 protrusions/μm or more.
The average number density of the protrusions constituting the needle-like structure is preferably 100 protrusions/μm or less, more preferably 80 protrusions/μm or less, and even more preferably 60 protrusions/μm or less.
When the average number density of the protrusions constituting the acicular structure is within the above range, the interval between the protrusions is adjusted to the optimum interval for the resin contained in the resin member to enter.

The average height of the protrusions constituting the needle-like structure is preferably from 1 nm to 1000 nm, more preferably from 30 nm to 900 nm, and even more preferably from 50 nm to 800 nm.
When the average height of the protrusions constituting the needle-like structure is within the above range, the height of the protrusions is adjusted to an optimal height for the resin contained in the resin member to enter.

The average number density and average height of the protrusions constituting the needle-like structure are calculated from the cross-sectional profile of the metal member taken by a scanning electron microscope (SEM). Specifically, it is an arithmetic mean value of values measured at ten arbitrary points.

The method of forming the needle-like structure on the surface of the metal member is not particularly limited.
For example, the method for forming a dendritic structure described above may be used.

(3) Particulate structure In the present disclosure, "particulate structure" refers to a state in which fine irregularities are formed on the surface of the metal member by particles present on the surface of the metal member for the resin constituting the resin member to enter. means structure.

The type of particles constituting the particulate structure is not particularly limited, but examples include silica particles, tin oxide particles, nanodiamond particles, zirconia particles, niobium oxide particles, iron oxide particles, alumina particles, carbon nanofibers, and the like. Among these, silica particles are preferred.

The size of the particles constituting the particulate structure is not particularly limited, but the average particle diameter is preferably 1 nm or more and 100 nm or less, more preferably 1 nm or more and 70 nm or less, still more preferably 1 nm or more and 50 nm or less, and More preferably, it is 1 nm or more and 30 nm or less, particularly preferably more than 1 nm and less than 20 nm.
The particles constituting the particulate structure may be in the form of secondary particles in which a plurality of primary particles are aggregated. In this case, the average particle diameter is the average particle diameter of primary particles constituting the secondary particles.

When the average particle diameter of the particles constituting the particulate structure is within the above range, the interval between the particles is adjusted to the optimum interval for the resin contained in the resin member to enter.

The average particle diameter of the particles constituting the particulate structure can be determined by observing a cross section of a metal member or structure using a transmission electron microscope (TEM), a scanning electron microscope (SEM), or the like.
Specifically, the particle size of the particles constituting the particulate structure observed in the cross section of the metal member or structure is measured, and the average value of the measured values of 100 particles is taken as the average particle size.

The method of forming the particulate structure on the surface of the metal member is not particularly limited.
For example, the surface of the metal member may be immersed in a dispersion of particles to form a particulate structure, or a dispersion of particles to form a particulate structure may be spray applied to the metal surface. .

The average thickness of the fine structure formed by the particulate structure is preferably from 1 nm to 1000 nm, more preferably from 10 nm to 500 nm, even more preferably from 30 nm to 200 nm, and even more preferably from 50 nm to 100 nm. is most preferable.

The average thickness of the microstructure is calculated from the cross-sectional profile of the metal member using a scanning electron microscope (SEM). Specifically, it is the arithmetic mean value of the values measured at ten arbitrary points on the cross-sectional profile of a portion of the metal member having an uneven structure on its surface.

From the viewpoint of increasing the bonding strength with the resin member, it is preferable that the surface of the metal member on which the fine structure is formed satisfies at least one of the following (1) and (2).
(1) The average value of ten-point average roughness (Rzjis) is 2 μm to 100 μm.
(2) The average value of the average length (RSm) of the roughness curve elements is 10 μm to 500 μm.

When the surface of the metal member satisfies at least either (1) or (2), the surface of the metal member has a nanometer-order fine structure (hereinafter also referred to as a fine rough surface) and a micrometer-order uneven structure ( It can be determined that this is a state in which a base rough surface (hereinafter also referred to as a base rough surface) is formed (hereinafter also referred to as a double rough surface).

In the present disclosure, the ten-point average roughness (Rzjis) of the surface of a metal member is measured in accordance with JIS B0601:2001 (corresponding international standard: ISO4287).
In the present disclosure, the average length (RSm) of the surface roughness curve element of a metal member is measured in accordance with JIS B0601:2001 (corresponding international standard: ISO4287).

The average value of the ten-point average roughness (Rzjis) on the surface of the metal member is preferably in the range of 5 μm to 80 μm, more preferably 8 μm to 60 μm, and even more preferably 10 μm to 50 μm.
The average value of the ten-point average roughness (Rzjis) on the surface of the metal member is the arithmetic mean value of the values measured at arbitrary ten points on the surface of the metal member having an uneven structure.

The average value of the average length (RSm) of the roughness curve elements on the surface of the metal member is preferably in the range of 50 μm to 450 μm, more preferably 70 μm to 400 μm, still more preferably 70 μm to 350 μm, even more preferably 70 μm to 300 μm. It is in.
The average value of the average length (RSm) of the roughness curve elements on the surface of the metal member is the arithmetic mean value of the values measured at ten arbitrary points on the surface of the metal member having an uneven structure.

A metal member having a base roughened surface formed on the surface can be obtained by, for example, performing a roughening treatment on the surface of the metal member.
As a method for roughening a metal member, 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 anodic oxidation as disclosed in Japanese Patent No. 4541153; an acid-based etching agent (preferably , an inorganic acid, ferric ion or cupric ion) and, if necessary, an acid-based etching agent aqueous solution containing manganese ion, aluminum chloride hexahydrate, sodium chloride, etc.; International Publication No. A method of immersing the surface of a metal member in one or more aqueous solutions selected from hydrated hydrazine, ammonia, and water-soluble amine compounds as disclosed in 2009/31632 (NMT method); JP 2008-162115 Examples include a hot water treatment method as disclosed in the above publication; and roughening treatment such as blasting treatment.

The roughening treatment of the metal member may include forming a porous plating layer on the surface of the metal member as described in Japanese Patent No. 5366076.

Among the above methods, treatment with an acid-based etching agent is preferred from the viewpoint of increasing the bonding strength of the metal member to the resin member.
Examples of the treatment with an acidic etching agent include a method in which the following steps (1) to (4) are performed in this order.

(1) Pre-treatment step A pre-treatment is performed to remove the film made of oxide film, hydroxide, etc. present on the surface of the metal member. Usually, mechanical polishing or chemical polishing treatment is performed. If the surface of the metal member is heavily contaminated with machine oil or the like, treatment with an alkaline aqueous solution such as a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution, or degreasing may be performed.

(2) Treatment step with a zinc ion-containing alkaline aqueous solution In a zinc ion-containing alkaline aqueous solution containing alkali hydroxide (MOH) and zinc ions (Zn ²⁺ ) at a mass ratio (MOH/Zn ²⁺ ) of 1 to 100, The treated metal member is immersed to form a zinc-containing film on the surface. Note that M in the MOH is an alkali metal or an alkaline earth metal.

(3) Treatment step with acid-based etching agent After step (2), the metal member is treated with an acid-based etching agent containing at least one of ferric ions and cupric ions, and an acid. The zinc-containing film on the surface is eluted and a fine uneven shape on the order of micrometers is formed.

(4) Post-treatment step After the above step (3), the metal member is cleaned. It usually consists of washing with water and drying operations. Ultrasonic cleaning operations may be included for smut removal.

If necessary, the roughening treatment of the metal member may be performed two or more times.

To obtain a metal member having a double rough surface structure by forming a base rough surface on the surface of the metal member and then forming a fine structure (fine rough surface) on the surface of the metal member on which the base rough surface has been formed. Can be done.

From the viewpoint of achieving good bonding strength, the absorbance A ₁ of the absorption peak at 3400 cm ^-1 observed by Fourier transform infrared spectroscopy of the surface of the metal member, the absorbance at 3800 cm ^-1 and the absorbance at 2500 cm ^-1 are It is preferable that the difference between the connecting straight line and the absorbance A ₀ at 3400 cm ⁻¹ (A ₁ −A ₀ ) is 0.03 or less.

The broad absorption peak with a peak top at 3400 cm ⁻¹ observed in the FTIR measurement is estimated to be a peak resulting from aluminum hydroxide or aluminum hydrated oxide.
Therefore, the absorbance difference (A ₁ - _{A 0} ) is an index indicating the degree of retention of hydroxyl groups on the surface of the metal member, and the smaller the value of the absorbance difference (A ₁ - A ₀ ), the more hydroxyl groups exist on the surface of the metal member. The amount of hydroxyl groups is small.
The reason why good bonding strength is maintained when the absorbance difference is 0.03 or less is not necessarily clear, but the present inventors think as follows.
The larger the amount of hydroxyl groups present on the surface of a metal member (that is, the larger the value of the absorbance difference (A ₁ - _{A 0} )), the easier it is for the metal member to adsorb moisture in the surrounding environment, forming a layer of water molecules on the surface. It becomes easier to form. This water molecule layer causes a decrease in the bonding strength of the metal member to the resin member. When the value of the absorbance difference (A ₁ -A ₀ ) is 0.03, the amount of moisture adsorbed on the surface of the metal member on which the fine structure is formed is sufficiently small, and good bonding strength is achieved.
The absorbance difference (A ₁ −A ₀ ) may be 0.02 or less, or 0.015 or less. The absorbance difference (A ₁ -A ₀ ) may be 0.005 or more, or 0.01 or more.
The absorbance difference (A ₁ -A ₀ ) is determined from an FTIR chart obtained by employing a high-sensitivity reflection method (RAS method) and setting the incident angle of infrared light to 85°.

(Resin member)
In the present disclosure, the tensile modulus of elasticity at 23°C of a resin member is measured using a tensile tester in accordance with JIS K6254 (2016) at a measurement temperature of 23°C, 50% RH, and a tensile speed of 50 mm/min. do.
Examples of the resin member having a tensile modulus at 23° C. of 500 MPa or less include resin members containing a thermoplastic elastomer or a thermosetting elastomer as a resin.

Examples of thermoplastic elastomers include styrene elastomers, polyolefin elastomers, polyurethane elastomers, polyester elastomers, and polyamide elastomers. Furthermore, a blend of two or more elastomers selected from these can also be used.

Examples of thermosetting elastomers include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), chloroprene rubber (CR), and acrylonitrile-butadiene copolymer rubber ( Non-diene rubbers such as NBR), butyl rubber (IIR), ethylene/propylene rubber (EPM), ethylene/α-olefin/non-conjugated polyene copolymers, urethane rubber, silicone rubber, acrylic rubber, etc. Can be mentioned. Furthermore, a blend of two or more elastomers selected from these can also be used.

Among thermosetting elastomers, ethylene/α-olefin/nonconjugated polyene copolymers are preferred because their raw material costs are relatively low, they exhibit excellent mechanical properties, and molded products with good rubber elasticity can be obtained. preferable.
In the present disclosure, an ethylene/α-olefin/non-conjugated polyene copolymer (hereinafter also referred to as “copolymer (A)”) refers to a structural unit derived from ethylene, a structural unit derived from an α-olefin, and a non-conjugated polyene copolymer. It means a copolymer containing a structural unit derived from a conjugated polyene.

Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, Examples include α-olefins having 3 to 20 carbon atoms such as 1-hexadecene and 1-eicosene. Among these, α-olefins having 3 to 10 carbon atoms such as propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene are preferred, and propylene and 1-butene are more preferred. The copolymer (A) may contain structural units derived from one or more α-olefins.

Examples of the non-conjugated polyene include cyclic or chain-shaped non-conjugated polyenes. Examples of the cyclic non-conjugated polyene include 5-ethylidene-2-norbornene (ENB), dicyclopentadiene, 5-vinyl-2-norbornene (VNB), norbornadiene, and methyltetrahydroindene. Examples of the linear nonconjugated polyene include 1,4-hexadiene, 7-methyl-1,6-octadiene, 8-methyl-4-ethylidene-1,7-nonadiene, and 4-ethylidene-1,7-undecadiene. can be mentioned. From the viewpoint of availability and heat resistance of the resulting molded product, ENB and VNB are preferred as the non-conjugated polyene. The copolymer (A) may contain structural units derived from one or more non-conjugated polyenes.

Specific examples of the copolymer (A) include ethylene/propylene/non-conjugated polyene copolymers (ethylene/propylene/diene rubber, etc.) and ethylene/1-butene/non-conjugated polyene copolymers.

The thermosetting elastomer may contain a crosslinking agent (vulcanizing agent). Examples of the crosslinking agent include sulfur-based crosslinking agents, peroxide-based crosslinking agents, resin-based crosslinking agents, amine-based crosslinking agents, polyol-based crosslinking agents, etc., and can be selected depending on the type of thermosetting elastomer.

The thermosetting elastomer may contain a crosslinking aid (vulcanization aid). Thiazole compounds and sulfenamide compounds are used as crosslinking aids. Examples include thiuram compounds, dithiocarbamates, guanidine compounds, and allyl compounds, which can be selected depending on the type of thermosetting elastomer.

The resin member may contain components other than those mentioned above. Ingredients other than those mentioned above include oil, fatty acids such as stearic acid, fillers such as glass fiber, carbon fiber, and inorganic powder, heat stabilizers, antioxidants, pigments, weathering agents, flame retardants, plasticizers, and dispersions. agent, lubricant, mold release agent, antistatic agent, etc.

When the resin member contains components other than 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 even more preferably 30% by mass or more. preferable.

<Method for manufacturing structure>
A method for manufacturing a structure according to the present disclosure includes a step of preparing a metal member having a surface on which at least one microstructure selected from a dendritic structure, an acicular structure, and a particulate structure is formed;
The method includes the step of applying heat and pressure to the resin member while the resin member is in contact with the surface of the metal member on which the fine structure is formed.

According to the above method, a structure with excellent bonding strength can be manufactured even if the resin member has a tensile modulus of elasticity at 23° C. of 500 MPa or less or contains a thermosetting elastomer.

The above method is particularly suitable when the resin member includes a thermosetting elastomer. Specifically, by applying heat while a resin member containing an uncured thermosetting elastomer is in contact with a surface of a metal member on which a fine structure is formed, a curing reaction of the thermosetting elastomer occurs. In addition, by applying pressure while the resin member containing the uncured thermosetting elastomer is in contact with the surface of the metal member on which the microstructure has been formed, the uncured thermosetting elastomer is made to have a microstructure. By penetrating into gaps and adsorbing at the molecular chain level, it exhibits an excellent anchoring effect.

The method of applying heat and pressure to the resin member in contact with the metal member is not particularly limited, and can be carried out by known methods such as press molding, injection molding, and compression molding.
The resin member may or may not have fluidity before applying heat and pressure while in contact with the metal member.

(Usage of structure)
The use of the structure of the present disclosure is not particularly limited.
For example, sealing members such as waterproof packing, oil-proof packing, liquid-proof packing, vacuum packing, packing for pressure equipment, vibration-absorbing members, vibration-suppressing members, stress relaxation members, members for mobile devices, solar cell members, and lithium ion batteries. Examples include parts for industrial use, parts for housing and construction, parts for automobiles, and parts for aerospace.

Hereinafter, embodiments according to the present disclosure will be described with reference to Examples. Note that the present disclosure is in no way limited to the description of these examples.

<Metal member A>
An aluminum alloy plate (thickness: 2.0 mm) having alloy number A5052 specified in JIS H4000 was cut into a length of 220 mm and a width of 25 mm, and degreased. Thereafter, an area of 60 mm from one end was masked with masking tape.
The masked aluminum alloy plate was immersed for 2 minutes in a treatment tank 1 filled with an alkaline etching agent (30°C) containing 19.0% by mass of sodium hydroxide and 3.2% by mass of zinc oxide, Washed with water. Next, the obtained aluminum alloy plate was treated with an acid-based etching aqueous solution ( The sample was immersed for 6 minutes in a treatment tank 2 filled with a temperature of 30° C., and then agitated. The above processing steps are referred to as "processing 1." Next, ultrasonic cleaning was performed under running water (in water for 1 minute).

After treatment 1, the aluminum alloy plate was treated with an acid-based etching aqueous solution (40% by mass) containing 6.3% by mass of cupric oxide (5.0% by mass as Cu2+) and 30.0% by mass of nitric acid. The sample was immersed for 5 minutes in a treatment tank 3 filled with a temperature of 30.degree. C.) and agitated. The above processing steps are referred to as "processing 2." Next, the aluminum alloy plate was washed with running water and dried at 80° C. for 15 minutes. The standard electrode potential E0 of Cu2+ used in Process 2 is +0.337 (V vs. SHE). The aluminum alloy plate after processing 2 was designated as metal member A.

The surface roughness of the metal member A is determined by the ten-point average roughness (Rzjis) and The average length (RSm) of each roughness curve element was measured. As a result, the average value of Rzjis was 18 μm, and the average value of RSm was 139 μm.
・Stylus tip radius: 5μm
・Standard length: 0.8mm
・Evaluation length: 4mm
・Measurement speed: 0.06mm/sec

A sample for cross-sectional observation was prepared by injection molding polypropylene on one side of metal member A, and the cross-section of the sample was observed using a SEM. As a result, as shown in FIG. 1, an uneven structure on the order of micrometers was formed on the surface of the metal member A. Further, as shown in FIG. 2, a fine structure containing dendritic or acicular projections made of aluminum oxide with a height of 100 nm and an interval of about 20 nm was formed on the surface of the uneven structure.

The FT-IR spectrum of the surface of metal member A was measured using a device that combines a Shimadzu Fourier transform infrared spectrophotometer (FTIR) and a high-sensitivity reflectance measuring device (RAS-8000). Measurements were made with the angle set at 85°. ^The _absorbance ^difference ⁽ _A ¹ _{_} -A ₀ ) was 0.01.

<Metal member B>
In the production of metal member A, an aluminum alloy plate that was not subjected to treatment 2 after treatment 1 was used as metal member B.

The surface roughness of the metal member B is determined by the ten-point average roughness (Rzjis) and The average length (RSm) of each roughness curve element was measured. As a result, the average value of Rzjis was 19 μm, and the average value of RSm was 142 μm.

A sample for cross-sectional observation was prepared by injection molding polypropylene on one side of metal member B, and the cross-section of the sample was observed using a SEM. As a result, an uneven structure on the order of micrometers as shown in FIG. 1 was formed on the surface of the metal member B, but a fine structure as shown in FIG. 2 was not formed.
The absorbance difference (A ₁ −A ₀ ) calculated from the FT-IR spectrum of the surface of metal member B was 4.

<Metal member C>
An aluminum alloy plate (thickness: 2.0 mm) having alloy number A5052 specified in JIS H4000 was cut into a length of 45 mm and a width of 18 mm, and degreased.
The same treatment 1 and treatment 2 as for metal member A were performed on the degreased aluminum alloy plate.

The surface roughness was measured in the same manner as for metal member A. As a result, the average value of R _zjis was 18 μm, and the average value of RS _m was 139 μm.

A sample for cross-sectional observation was prepared by injection molding polypropylene on one side of the metal member C, and the cross-section of the sample was observed using a SEM. As a result, an uneven structure on the order of micrometers as observed on the metal member A was formed on the surface of the metal member C. Further, a fine structure including dendritic or acicular projections made of aluminum oxide with a height of about 100 nm and an interval of about 20 nm was formed on the surface of the uneven structure.

The FT-IR spectrum of the surface of metal member C was measured using a device that combines a Shimadzu Fourier transform infrared spectrophotometer (FTIR) and a high-sensitivity reflectance measuring device (RAS-8000). Measurements were made with the angle set at 85°. ^The _absorbance ^difference ⁽ _A ¹ _{_} -A ₀ ) was 0.01.

<Example 1>
Uncured ethylene propylene diene rubber (product name: Mitsui EPT, grade name: A rectangular resin test piece was created by pressing using a mold. This resin test piece was further made in contact with one side of metal member A (both the masking area and the non-masking area) so that the shape of the resin part was 220 mm in length, 25 mm in width, and 2.0 mm in thickness. The sample of Example 1 was prepared by inserting the sample into another mold and press-molding it at 160° C. for 30 minutes at 15 MPa.
In the sample after press molding, the thermoset rubber layer was bonded only to the surface of the metal member A corresponding to the non-masking area.
A 90° peel test was performed on the sample using a peel tester. Specifically, the rubber layer that is not bonded to the metal member A in the masking area is grabbed with the grip of the testing machine, and the rubber layer is pulled at a speed of 50 mm/s in a direction 90 degrees from the surface of the metal member. The strength (N/cm) and the state of peeling when peeled off from metal member A were investigated. The results are shown in Table 1.

<Example 2>
A sample was prepared in the same manner as in Example 1, except that ethylene propylene diene rubber (trade name: Mitsui EPT, grade name: X4010M, manufactured by Mitsui Chemicals, Inc.) compounded with oil (10% by mass) was used. Then, a 90° peel test was conducted. The results are shown in Table 1.

<Example 3>
A sample was prepared in the same manner as in Example 1, except that ethylene propylene diene rubber (trade name: Mitsui EPT, grade name: X4010M, manufactured by Mitsui Chemicals, Inc.) compounded with stearic acid (2% by mass) was used. A 90° peel test was conducted. The results are shown in Table 1.

<Example 4>
A layer of polyolefin thermoplastic elastomer (trade name: Milastomer S650BS, manufactured by Mitsui Chemicals, Inc.) was formed on one side of metal member C by insert molding, and a sample for a shear test having a shape specified in ISO-19095 was prepared. .
Using the obtained sample, the metal part was fixed horizontally on a pedestal, and the tip of the resin part was chucked using a tensile testing machine so that the distance between the chucks (distance between the metal part and the chuck part) was 20 mm. A peel test was conducted by pulling the resin part up at a speed of 10 mm/sec in a direction of 90° to the bonding surface. The strength (N/cm) and the state of peeling when the olefin thermoplastic elastomer layer was peeled off from the metal member C were examined. The results are shown in Table 1.

<Example 5>
A sample was prepared in the same manner as in Example 4, except that a polyolefin thermoplastic elastomer (trade name: Milastomer S450B, manufactured by Mitsui Chemicals, Inc.) was used, and a 90° peel test was conducted. The results are shown in Table 1.

<Example 6>
A sample was prepared in the same manner as in Example 4 except that a polyurethane thermoplastic elastomer (trade name: Elastran C70A11FG, manufactured by BASF) was used, and a 90° peel test was conducted. The results are shown in Table 1.
The reason why the 90° peel test showed interfacial peeling is because the strength of the resin itself was high and material failure did not occur, and it can be evaluated that sufficient bonding strength was achieved.

<Example 7>
A sample was prepared in the same manner as in Example 4, except that a polyamide thermoplastic elastomer (trade name: Pebax 2533, manufactured by Arkema) was used, and a 90° peel test was conducted. The results are shown in Table 1.
The reason why the 90° peel test showed interfacial peeling is because the strength of the resin itself was high and material failure did not occur, and it can be evaluated that sufficient bonding strength was achieved.

<Comparative example 1>
A sample was prepared in the same manner as in Example 1 except that metal member B was used instead of metal member A, and a 90° peel test was conducted. The results are shown in Table 1.

<Comparative example 2>
A sample was prepared in the same manner as in Example 2 except that metal member B was used instead of metal member A, and a 90° peel test was conducted. The results are shown in Table 1.

<Comparative example 3>
A sample was prepared in the same manner as in Example 3 except that metal member B was used instead of metal member A, and a 90° peel test was conducted. The results are shown in Table 1.

As shown in Table 1, the samples of the example fabricated using metal member A and metal member C with microstructures formed on their surfaces showed material failure in the peel test and exhibited excellent bonding strength. was confirmed. In particular, the samples of Examples 1 to 3 that used thermosetting elastomer as the resin member had higher bonding strength than the samples of Comparative Examples 1 to 3 that were fabricated using metal member B on which no microstructure was formed. has improved markedly.
As shown in Table 1, according to the present disclosure, the bonding strength to the resin member can be improved by physical means of forming a fine structure on the surface of the metal member. Therefore, the present disclosure is applicable not only to specific types of metal members or resin members.

The disclosure of Japanese Patent Application No. 2022-128431 is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards mentioned herein are incorporated by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference. Incorporated herein by reference.

Claims

A metal member having a surface on which at least one or more microstructures selected from a dendritic structure, a needle-like structure, and a particulate structure are formed;
a resin member bonded to the surface of the metal member on which the fine structure is formed;
The resin member is a structure having a tensile modulus of elasticity of 500 MPa or less at 23°C.
A metal member having a surface on which at least one or more microstructures selected from a dendritic structure, a needle-like structure, and a particulate structure are formed;
a resin member bonded to the surface of the metal member on which the fine structure is formed;
A structure in which the resin member includes a thermosetting elastomer.
The structure according to claim 1 or 2, wherein the average thickness of the fine structure is 1 nm to 1000 nm.
The structure according to claim 1 or 2, wherein the surface has an average ten-point roughness (Rzjis) of 2 μm to 100 μm.
The structure according to claim 1 or 2, wherein the average value of the average length (RSm) of the surface roughness curve element is 10 μm to 500 μm.
The difference between the absorbance A 1 of the absorption peak at 3400 cm −1 observed by Fourier transform infrared spectroscopy of the surface and the absorbance A 0 at 3400 cm −1 of the straight line connecting the absorbance at 3800 cm −1 and the absorbance at 2500 cm −1 The structure according to claim 1 or 2, wherein (A 1 -A 0 ) is 0.03 or less.
The structure according to claim 1, wherein the resin member includes a thermosetting elastomer or a thermoplastic elastomer.
preparing a metal member having a surface on which at least one microstructure selected from a dendritic structure, a needle-like structure, and a particulate structure is formed;
The method for manufacturing a structure according to claim 1 or 2, comprising the step of applying heat and pressure to the resin member while the resin member is in contact with the surface of the metal member on which the fine structure is formed. .