WO2022044868A1 - Cladding composition, and method for manufacturing metal/resin joined member - Google Patents

Abstract

In the present invention, a cladding composition containing a metal powder, a binder, and an organic solvent is used when joining a metal substrate and a resin member. A first metal powder and a second metal powder are used in combination as the metal powder. A metal having a lower corrosion electric potential than the metal constituting the first metal powder is selected as the metal constituting the second metal powder. There is also used a manufacturing method having a step for applying the cladding composition to at least part of a metal substrate, a step for irradiating the section of the metal substrate to which the cladding composition was applied with a laser, a step for positioning a resin member on the section of the metal substrate that was irradiated with the laser, and a step for heating the interface between the resin member and the portion irradiated with the laser and joining the metal substrate and the resin member.

Description

Method for manufacturing a composition for cladding and a metal / resin bonding member

The present invention relates to a cladding composition and a method for manufacturing a metal / resin bonding member. This application claims priority based on Japanese Patent Application No. 2020-143895 filed in Japan on August 27, 2020, the contents of which are incorporated herein by reference.

In recent years, from the viewpoint of environmental load, reduction of carbon dioxide (CO ₂ ) emissions is naturally required in automobiles.
On the other hand, hybrid vehicles and electric vehicles that reduce the consumption of gasoline, which is a fuel, are being produced. In addition, in order to improve fuel efficiency, attention is being paid to reducing the weight of the vehicle body, and studies are underway to apply a lighter and more durable new material to the vehicle body.

Examples of the new material include those in which different materials are joined together.
Adhesives are commonly used when joining dissimilar materials together. However, the use of an adhesive has a large environmental load, the adhesive itself deteriorates over time, and there is a problem in terms of bonding strength.

As a technique for solving such a problem, a method of joining different kinds of materials without using an adhesive has been proposed.
For example, in Patent Document 1, a metal powder is adhered to one surface of a metal substrate and irradiated with a laser to form a superimposed fine particle structure alloyed with the metal substrate, and the superimposed fine particles are formed. A joining method for joining a metal base material and a resin member by pressing a resin member against a structure and irradiating the interface with a laser to heat the structure is disclosed.

Japanese Patent No. 5935559

However, in the joining method described in Patent Document 1, powdered metal is applied to the metal base material. Therefore, when the metal base material is arranged on an inclined surface, the metal base material and the resin member are combined. Difficult to join stably.
Further, in an accelerated test under high temperature and high humidity, the bonding strength between the metal base material and the resin member tends to decrease, and it is difficult to maintain the bonding strength between the two.
Further, there is also a problem that it is conventionally difficult to join the metal base material and the resin member in an environment unsuitable for the use of powder, such as vibration of the joining place.

The present invention has been made in view of the above circumstances, and the bonding strength between the metal base material and the resin member is higher and the deterioration of the bonding strength over time in a specific environment is suppressed without using an adhesive. An object of the present invention is to provide a method for manufacturing a metal / resin joint member. Another object of the present invention is to provide a cladding composition capable of stably bonding a metal base material and a resin member and suppressing deterioration of the bonding strength over time.

In order to solve the above problems, the present invention has adopted the following configuration.
That is, in the first aspect of the present invention, the metal containing the first metal powder, the second metal powder, the binder, and the organic solvent, and the metal constituting the second metal powder is the first. It is a composition for cladding characterized by being a metal having a lower corrosion potential than the metal constituting the metal powder of.

A second aspect of the present invention is a method for manufacturing a metal / resin joining member in which a metal base material and a resin member are joined, and a bracket of the first aspect of the present invention is applied to at least a part of the metal base material. The step (i) of applying the coating composition, the step (ii) of irradiating the coating portion of the cladding composition on the metal substrate with a laser, and the step of irradiating the laser irradiation portion of the metal substrate with the metal substrate. Having a step (iii) of arranging the resin member and a step (iv) of heating the interface between the laser irradiation unit and the resin member to join the metal base material and the resin member. This is a characteristic method for manufacturing a metal / resin joint member.

According to the method for manufacturing a metal / resin bonding member of the present invention, the bonding strength between the metal base material and the resin member is higher and the deterioration of the bonding strength over time in a specific environment is suppressed without using an adhesive. Metal / resin joint members can be manufactured.
Further, according to the cladding composition of the present invention, the metal base material and the resin member can be stably bonded, and the deterioration of the bonding strength between the metal base material and the resin member with time can be suppressed.

It is a graph which shows the result of having measured the time-dependent change of the bonding strength in the 85/85 test for the bonding member manufactured by using each of the cladding compositions of Example 2 and Comparative Example 1.

(Composition for cladding)
The cladding composition of the present embodiment contains a first metal powder and a second metal powder as metal powder, a binder, and an organic solvent.
The "cladding composition" in the present invention refers to a material that melts and solidifies on the surface of a metal base material that is a base material to form beads (projections of an alloy).

<Metal powder>
As the metal powder in this embodiment, a first metal powder and a second metal powder are used. In addition, the metal constituting the second metal powder is a metal having a lower corrosion potential than the metal constituting the first metal powder.

In the present invention, the "corrosion potential" is a value based on a standard test method for measuring the corrosion potential of an aluminum alloy (standard ASTM G69 of the American Material Testing Association), or a method for measuring the pitting corrosion potential of stainless steel (JIS G 0757). Based values shall be used.
When the former corrosion potential based on the standard ASTM G69 is used, for example, Fig. The corrosion potentials of various metals shown in 5 can be used.
References: UACJ Technical Reports, Vol. 3 (1) (2016), pp. 52-56
"SHE" means a standard hydrogen electrode.

In the present embodiment, it is sufficient that there is at least a difference between the corrosion potential of the metal constituting the first metal powder and the corrosion potential of the metal constituting the second metal powder.
In a preferred embodiment, the difference between the corrosion potential of the metal constituting the first metal powder and the corrosion potential of the metal constituting the second metal powder is 100 mV (vs. SHE) or more, and 150 mV. It is more preferably (vs. SHE) or more, further preferably 200 mV (vs. SHE) or more, and the upper limit of the difference in the corrosion potential may be, for example, 1000 mV (vs. SHE) or less.
When the difference in corrosion potential is at least the lower limit of the above-mentioned preferable range, the bonding strength between the metal base material and the resin member is easily maintained, and deterioration over time is further suppressed.

≪First metal powder≫
Examples of the metal constituting the first metal powder in the present embodiment include aluminum, nickel, chromium, iron, copper, titanium, silicon, stellite, vanadium, or alloys thereof.
The first metal powder may be used alone or in combination of two or more. By combining two or more kinds of metals, it becomes easy to form a porous structure on the bead surface, and for example, it becomes easy to increase the bonding strength between the metal base material and the resin member.
The first metal powder preferably contains at least one selected from the group consisting of aluminum powder and titanium powder, and examples thereof include those containing aluminum powder and titanium powder.

It should be noted that aluminum and titanium tend to be passivated among various metals, and in the natural world, the surface is usually covered with a passivation layer. Therefore, the corrosion potential of aluminum in the present invention is the corrosion potential of passivated aluminum. The corrosion potential of titanium in the present invention is the corrosion potential of passivated titanium.

The content of the first metal powder is preferably 25 to 95% by mass, more preferably 30 to 80% by mass, and 40 to 70% by mass with respect to the total amount (100% by mass) of the cladding composition. Is more preferable, and 50 to 60% by mass is particularly preferable.
When the content of the first metal powder is not less than the lower limit of the above-mentioned preferable range, for example, the bonding strength between the metal base material and the resin member is more likely to be increased, while it is not more than the upper limit of the above-mentioned preferable range. If so, it will be easy to handle as a composition.

≪Second metal powder≫
Examples of the metal constituting the second metal powder in the present embodiment include magnesium and zinc.
The second metal powder may be used alone or in combination of two or more. The second metal powder preferably contains at least one selected from the group consisting of zinc powder and magnesium powder. Alternatively, a powder obtained by alloying magnesium and aluminum and a powder obtained by alloying zinc and aluminum may be used as the second metal powder.

The content of the second metal powder is preferably 0.01 to 20% by mass, more preferably 0.1 to 15% by mass, and 0, based on the total amount (100% by mass) of the cladding composition. .3 to 12% by mass is more preferable, 0.5 to 10% by mass is particularly preferable, and 1 to 10% by mass is most preferable.
When the content of the second metal powder is at least the lower limit of the above-mentioned preferable range, the bonding strength between the metal base material and the resin member is easily maintained, and deterioration with time is further suppressed. On the other hand, if it is not more than the upper limit of the above-mentioned preferable range, for example, the bonding strength between the metal base material and the resin member is likely to be further increased.

The metal powder in the present embodiment contains at least one selected from the group consisting of aluminum powder and titanium powder as the first metal powder, and from the group consisting of zinc powder and magnesium powder as the second metal powder. It is preferable to use a combination containing at least one selected metal powder, and a combination of a first metal powder containing aluminum powder and a titanium powder and a second metal powder containing zinc powder. It is more preferable to use it.

The average particle size of each of the first metal powder and the second metal powder is, for example, about 10 μm or more and 100 μm or less.
The "average particle size of powder" in the present invention means the value of the volume average particle size of powder measured by a known particle size distribution measuring device.

The total content of the first metal powder and the second metal powder is preferably 30 to 95.5% by mass, preferably 40 to 90% by mass, based on the total amount (100% by mass) of the cladding composition. The mass% is more preferable, 50 to 80% by mass is further preferable, and 60 to 70% by mass is particularly preferable.
When the total content of the metal powder is not less than the lower limit of the above-mentioned preferable range, for example, the bonding strength between the metal base material and the resin member is more likely to be increased, while it is not more than the upper limit of the above-mentioned preferable range. If there is, it becomes easy to handle as a composition.

The ratio of the content of the second metal powder to the total content of the first metal powder and the second metal powder is preferably 1 to 25% by mass, preferably 2 to 20% by mass. Is more preferable, 5 to 17.5% by mass is further preferable, and 7 to 15% by mass is particularly preferable.
When the content of the second metal powder is at least the lower limit of the above-mentioned preferable range, the bonding strength between the metal base material and the resin member can be easily maintained, and deterioration with time can be further suppressed. On the other hand, if it is not more than the upper limit of the above-mentioned preferable range, for example, the bonding strength between the metal base material and the resin member is likely to be further increased.

<Binder>
The binder in the present embodiment acts as a dispersant for metal powders and also as a viscosity modifier in the cladding composition.
An organic compound may be used or an inorganic compound may be used as the binder.

Examples of the organic compound in the binder include polyvinyl acetal, cellulose compounds, polyacrylic acid and other acrylic compounds, polyvinyl alcohol, epoxy compounds and the like.
Specific examples of the polyvinyl acetal include polyvinyl formal and polyvinyl butyral.
Specific examples of the cellulose compound include hydroxypropyl cellulose and hydroxyethyl cellulose.

Examples of the inorganic compound in the binder include clay minerals. Specific examples of clay minerals include bentonite, smectite, and montmorillonite.

The binder may be used alone or in combination of two or more.

The binder is preferably an organic compound, and among them, a binder containing polyvinyl acetal is preferable because it has strong adhesiveness to a metal and has good dispersibility with metal powder, and among them, a binder containing polyvinyl butyral is particularly preferable. preferable. Among polyvinyl butyral, for example, those having a mass average molecular weight (Mw) of 10,000 to 80,000, more preferably those having Mw of 20,000 to 60,000, and Mw are more preferable because the bonding strength between the metal base material and the resin member is likely to be increased. Is more preferably 30,000 to 50,000.

Further, the binder is more preferably one containing a cellulose compound because it is easy to adjust the viscosity of the composition. As the cellulose compound, hydroxypropyl cellulose is preferable. Among hydroxypropyl celluloses, for example, those having a Mw of 100,000 to 800,000 are preferable, those having a Mw of 110,000 to 700,000, and those having a Mw of 120,000 to 650000 are preferable because the bonding strength between the metal base material and the resin member is likely to be increased. Is more preferable.

The binder content is preferably 0.01 to 10% by mass, more preferably 0.05 to 7% by mass, and 0.1 to 5% by mass, based on the total amount (100% by mass) of the cladding composition. By mass% is more preferable, 0.2 to 5% by mass is particularly preferable, and 0.5 to 2% by mass is most preferable.
When the binder content is at least the lower limit of the above-mentioned preferable range, for example, the bonding strength between the metal base material and the resin member can be more easily increased, and the applicability of the composition to the metal base material can be improved. Improve more. On the other hand, if it is not more than the upper limit of the above-mentioned preferable range, it becomes easy to handle as a composition.

<Organic solvent>
Examples of the organic solvent in the present embodiment include those that serve as a dispersion medium for the above-mentioned first metal powder, second metal powder, and binder.
Specifically, as such an organic solvent, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-pentyl alcohol, s-pentyl alcohol, t-pentyl alcohol, isopentyl alcohol, 2-methyl-1-propanol, 2- Ethylbutanol, neopentyl alcohol, n-butanol, s-butanol, t-butanol, n-hexanol, 2-heptanol, 3-heptanol, 2-methyl-1-butanol, 2-methyl-2-butanol, 4-methyl -2-Pentanol, 1-butoxy-2-propanol, propylene glycol monopropyl ether, 5-methyl-1-hexanol, 6-methyl-2-heptanol, 1-octanol, 2-octanol, 3-octanol, 4- Chain-structured alcohols such as octanol, 2-ethyl-1-hexanol, 2- (2-butoxyethoxy) ethanol; cyclopentanemethanol, 1-cyclopentylethanol, cyclohexanol, cyclohexanemethanol, cyclohexaneethanol, 1,2,3 , 6-Tetrahydrobenzyl alcohol, exo-norborneol, 2-methylcyclohexanol, cycloheptanol, 3,5-dimethylcyclohexanol, benzyl alcohol, tarpionel and other alcohols with a cyclic structure; γ-butyrolactone and other lactones Ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin; ethylene glycol mono Compounds having an ester bond such as acetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate, monomethyl ethers, monoethyl ethers, monopropyl ethers, monomethyl ethers of the polyhydric alcohols or compounds having the ester bonds. Derivatives of polyhydric alcohols such as monoalkyl ethers such as butyl ether or compounds having an ether bond such as monophenyl ether [among these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferable]. Ring type like dioxane Ethers and esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethylbenzyl ether, Aromatic organic solvents such as cresylmethyl ether, diphenyl ether, dibenzyl ether, phenetol, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, simene, mesitylen, dimethylsulfoxide (DMSO) and the like can be mentioned. Be done.

As the organic solvent, one kind may be used alone, or two or more kinds may be used in combination. The organic solvent preferably contains a derivative of a polyhydric alcohol.
As the derivative of the polyhydric alcohol, the polyhydric alcohol or the monoalkyl ether of the compound having an ester bond is preferable, and specifically, PGMEA and PGME are preferably mentioned.

The content of the organic solvent is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, still more preferably 15 to 40% by mass, based on the total amount (100% by mass) of the cladding composition. , 20-30% by mass is particularly preferable.

<Other ingredients>
The cladding composition of the present embodiment may further contain other components other than the above-mentioned first metal powder, second metal powder, binder and organic solvent.
Examples of other components include carbon powder, surfactant and the like.

The cladding composition of the present embodiment further preferably contains carbon powder. By co-existing the carbon powder, the bead is easily formed by melting and solidifying on the surface of the metal base material which is the base material.
The average particle size of the carbon powder is, for example, about 10 nm or more and 100 μm or less.
The content of the carbon powder is preferably 0.1 to 40% by mass, more preferably 0.5 to 30% by mass, and 1 to 20% with respect to the total amount (100% by mass) of the cladding composition. % By mass is more preferred.
When the content of the carbon powder is not less than the lower limit of the above-mentioned preferable range, for example, the bonding strength between the metal base material and the resin member is more likely to be increased, while it is not more than the upper limit of the above-mentioned preferable range. For example, the fluidity of the composition becomes better.

In the cladding composition of the present embodiment, the mixing ratio (mass ratio) of the carbon powder and the metal powder (first metal powder and second metal powder) is the metal powder / carbon powder. = 3 to 30, more preferably 4 to 20, and even more preferably 5 to 15.
When the mixing ratio (mass ratio) of both is equal to or higher than the lower limit of the above-mentioned preferable range, for example, the bonding strength between the metal base material and the resin member can be more easily increased, while it is equal to or less than the upper limit of the above-mentioned preferable range. If so, the fluidity of the composition becomes better.

Method for Producing Cladding Composition:
The cladding composition of the present embodiment comprises, for example, a step of preparing a mixed solution of a binder and an organic solvent, and a step of mixing the mixed solution with a first metal powder and a second metal powder. It can be manufactured by the method.

In the mixed solution of the binder and the organic solvent, the binder concentration is preferably 0.01 to 80% by mass, more preferably 0.1 to 40% by mass, and 1 to 15% by mass with respect to the mixed solution (100% by mass). % Is more preferable.
When the binder concentration is not less than the lower limit of the above-mentioned preferable range, the applicability of the composition to the metal substrate is further improved, while when it is not more than the upper limit of the above-mentioned preferable range, the composition is appropriately applied. It becomes easy to adjust the viscosity.

The mixing ratio (mass ratio) of the mixed solution and the metal powder (first metal powder and second metal powder) is preferably mixed solution / metal powder = 20/80 to 50/50, 20. It is more preferably / 80 to 40/60, and even more preferably 25/75 to 30/70.

When mixing the mixed liquid and the metal powder, a mixed powder in which the metal powder and the carbon powder are mixed may be mixed in advance.

In the cladding composition of the above-described embodiment, the metal powder (first metal powder and second metal powder) is preferably dispersed in a mixed solution of the binder and the organic solvent. Examples of the cladding composition of the embodiment include forms such as pastes, slurries, and suspensions, and pastes are preferable.
The term "paste" as used herein means that the paste has fluidity and high viscosity, and the viscosity is in the range of 1000 cps (1 Pa · s) or more and 200,000 cps (200 Pa · s) or less. The viscosity of the paste indicates a value measured at 25 ° C. using an E-type viscometer.

(Manufacturing method of metal / resin joint member)
The manufacturing method of the first embodiment is a method for manufacturing a metal / resin bonding member in which a metal base material and a resin member are bonded, and the above-mentioned cladding composition is applied to at least a part of the metal base material. The step (i) of coating, the step of irradiating the coating portion of the cladding composition on the metal substrate with a laser (ii), and the step of arranging the resin member on the laser irradiation portion of the metal substrate. A step (iii) of heating the interface between the laser irradiation unit and the resin member to join the metal base material and the resin member (iv).

In the present embodiment, examples of the metal base material as the base material include aluminum alloys, aluminum die casts, stainless steel, SPCC (cold rolled steel sheet) and the like.
In the present embodiment, examples of the resin member include polyamide (nylon 6, nylon 6, 6, etc.), polycarbonate, polypropylene, polyphenylene sulfide (PPS), and the like.

[Step (i)]
In step (i), the above-mentioned cladding composition is applied to at least a part of the metal substrate.
The method of applying the composition for cladding is not particularly limited, and examples thereof include screen application, dispenser, and spraying.
The thickness of the coating film of the cladding composition applied to the metal substrate may be appropriately set according to the compounding components of the composition and the like, and is, for example, about 50 to 200 μm.

[Step (ii)]
In the step (ii), the coated portion of the cladding composition on the metal substrate is irradiated with a laser.
The laser that irradiates the coated portion may be any laser that can heat the metal powder, and examples thereof include a semiconductor laser, a fiber laser, an Nd: YAG laser, and a carbon dioxide gas laser.

The coated part is irradiated with a laser and the metal powder melts. The metal in the molten state is alloyed with the metal base material to form beads (protrusions of the alloy, so-called overlay portions) on the surface of the metal base material. In addition, the binder and the like are burnt down by heating by laser irradiation.

From the viewpoint of the bonding strength between the metal base material and the resin member, the bead preferably has a size (height with respect to the metal base material surface) of 1 μm or more and 200 μm or less. In addition, this bead has a superposed fine particle structure.

In the present invention, the "superimposed fine particle structure" refers to a microstructure in which the fine concavo-convex shape structure is superposed on the fine concavo-convex shape surface. An anchor effect is exhibited by forming beads having a superposed fine particle structure on the surface of the metal substrate.
The superimposed fine particle structure includes the case where an alloy layer made of any of eutectic, solid solution, and intermetallic compound is formed.

[Step (iii)]
In the step (iii), the resin member is arranged on the laser irradiation portion of the metal substrate.
As a method of arranging the resin member on the laser irradiation part, for example, a method of applying a resin composition which is a material of the resin member on the laser irradiation part to form a film, or a method of irradiating a molded body of the resin composition with a laser. There is a method of arranging it on the department.
Further, when arranging the resin member on the laser irradiation portion, it is preferable that the resin member is in contact with and pressed against the metal base material.

As for the degree of pressing when the resin member is pressed against the metal substrate, generally, the optimum conditions may be selected in the pressure range of 0.1 to 3 MPa. As a result, the joint strength between the two is sufficiently increased.

[Step (iv)]
In the step (iv), the interface between the laser irradiation unit and the resin member is heated to bond the metal base material and the resin member to obtain a metal / resin bonding member.
The method for heating the interface is not particularly limited, and examples thereof include heating by a heater and heating by laser irradiation. The method for heating the interface between the laser irradiation unit and the resin member is preferably heating by laser irradiation.

The bead having a superposed fine particle structure formed on the surface of the metal substrate does not have transparency with respect to the wavelength of the laser. Therefore, in the case of heating by laser irradiation, the laser irradiated on the bead surface is converted into heat. The converted heat propagates to the surface of the resin member that is in contact and pressed, and melts the resin member. The molten resin member permeates the inside of the superimposed fine particle structure, and as a result, the metal base material and the resin member are firmly bonded to each other.

Also, in the case of heating by laser irradiation, the method of irradiating the laser from the resin member side is common. However, when the laser does not pass through the resin member and the other metal base material absorbs the laser, the metal is transmitted by irradiating the laser from the metal base material side, contrary to the general case. The interface between the metal base material and the resin member can be heated by heat.

In the production method of the first embodiment described above, a cladding composition containing a binder and an organic solvent is used and superimposed together with the first metal powder and the second metal powder having different metal corrosion potentials. A bead having a fine particle structure is formed on the surface of the metal substrate. Therefore, the metal constituting the second metal powder having a relatively low corrosion potential acts as a sacrificial anode material with respect to the metal constituting the first metal powder having a relatively high corrosion potential. Corrosion prevention of the entire bead is achieved.
Therefore, according to the manufacturing method of the first embodiment, the bonding strength between the metal base material and the resin member is higher and the deterioration of the bonding strength in a specific environment with time is suppressed without using an adhesive. A metal / resin joint member can be manufactured. The bonding strength of the metal / resin bonding member produced by the production method of the first embodiment is, for example, 35 to 80 MPa.
In addition, according to the manufacturing method of the first embodiment, the bonding strength between the metal base material and the resin member is lowered for a long period of time, especially in an accelerated test under high temperature and high humidity, for example, for more than one month. It is possible to manufacture a metal / resin bonding member that is suppressed and the bonding strength between the two is kept stable.

In addition, the cladding composition used has an appropriate viscosity by containing a binder and an organic solvent together with the metal powder (first metal powder and second metal powder), so that the metal base material has a metal base material. Even when the composition is arranged on an inclined surface, the composition can be reliably applied to the planned joining site.

In addition, the cladding composition used can be applied to the planned joining site in a less uniform amount and in a more uniform state than the conventional metal powder. For this reason, the utilization efficiency of the cladding composition is particularly improved during laser irradiation.

Further, the cladding composition used can be uniformly applied even if the metal base material has a wider size than the conventional metal powder. Therefore, the composition is useful for joining members having a wide size.

In the cladding composition used, since the binder is contained together with the metal powder (first metal powder and second metal powder), a bead having an appropriate coarse and dense distribution and a large unevenness is formed. Cheap. Therefore, the bonding strength can be further increased, and the metal base material and the resin member can be stably bonded.

<Other embodiments>
The method for producing the cladding composition and the metal / resin bonding member according to the present invention is not limited to the above-described embodiment, and for example, in the production method of the first embodiment, the method used for the cladding composition is the first. As the metal powder of No. 1, it is preferable to use a mixed metal powder of one or more metals that are the same as the metal constituting the metal base material and other metals. By applying the cladding composition containing such a mixed metal powder, the compatibility between the metal powder and the metal base material is enhanced. Therefore, beads having an appropriate coarse and dense distribution are likely to be formed on the surface of the metal substrate. As a result, the metal base material and the resin member can be joined more firmly and stably.
Further, as another embodiment, for example, use in the cladding of a composition containing a first metal powder, a second metal powder, a binder, and an organic solvent, wherein the second metal powder is used. Examples of the metal constituting the metal powder include those having a lower corrosion potential than the metal constituting the first metal powder.

According to the manufacturing method of the above-described embodiment, the metal base material and the resin member can be joined more firmly and with high reliability without using an adhesive. Therefore, the manufacturing method to which the present invention is applied is useful as a method for manufacturing a new material that realizes weight reduction of the vehicle body.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

<Preparation of composition for cladding>
(Examples 1 to 3, Comparative Example 1)
Each component shown in Table 1 was mixed to prepare a cladding composition for each example. The morphology of the cladding composition of each example is also described.

In Table 1, each abbreviation has the following meaning. The numerical value in [] is the content in the composition (ratio (mass%) to the total amount (100% by mass) of the composition).
The corrosion potential of the metal constituting the metal powder shown below is a value based on a standard test method (standard ASTM G69) for measuring the corrosion potential of an aluminum alloy.

(M1) -1: Aluminum powder (passivation), volume average particle diameter 37 μm, corrosion potential minus 500 mV (vs. SHE)

(M1) -2: Titanium powder (passivation), volume average particle diameter 28 μm, corrosion potential 300 mV (vs. SHE)

(M2) -1: Zinc powder, volume average particle diameter 25 μm, corrosion potential minus 800 mV (vs. SHE)

(B) -1: Polyvinyl butyral, Mw38000
(S) -1: Propylene glycol monomethyl ether (C) -1: Carbon powder, volume average particle diameter 40 nm

<Manufacturing of metal / resin joint members>
A metal / resin joint member was manufactured using the metal base material and the resin member shown below.
Metal base material: A5052 aluminum plate with a length of 5 cm x width of 2 cm x thickness of 1 mm Resin member: a sheet made of polyphenylene sulfide (PPS) with a length of 5 cm x width of 2 cm x thickness of 1 mm

Step (i):
Each of the cladding compositions of Examples 1 to 3 and Comparative Example 1 described above is applied to the aluminum plate, which is a metal base material, in a pattern having a thickness of 100 μm and a width direction of 2 mm and a length direction of 1.5 cm. did.

Step (ii):
Next, the coated portion of the cladding composition on the aluminum plate was irradiated with a laser to form beads (alloy protrusions) on the surface of the aluminum plate.
For the laser irradiation here, a semiconductor laser having a wavelength of 970 nm, which was shaped into a spot beam having a diameter of 2 mm by using an optical system, was used. The scanning speed of the spot beam was set to 30 mm / s. The spot beam was scanned over a width of 20 mm to irradiate an area of 40 mm ² or more.

Step (iii):
Next, a sheet made of PPS, which is a resin member, was placed on the bead formed on the surface of the aluminum plate and pressed. Pressing is performed by backing from the metal base material side with a metal backing plate, sandwiching the resin member with a glass plate (Tempax, thickness 5 mm), and applying a pressure of 1.4 MPa on the display with a hydraulic pump. rice field.

Step (iv):
Next, the interface between the bead formed on the aluminum plate surface and the sheet made of PPS is heated by irradiating the laser spot of a semiconductor laser shaped into a spot shape from the resin member side to form an aluminum plate. A joining member with a sheet made of PPS was obtained.
The irradiation conditions of the laser spot here were an average output of 150 W, a repetition frequency of 1000 Hz, a duty of 50%, and a scanning speed of 10 mm / s.

<Evaluation (1)>
Regarding the bonding member of the aluminum plate and the sheet made of PPS produced by using each of the cladding compositions of Example 1, Example 2, Example 3, and Comparative Example 1, the bonding strength immediately after production and one week. The joint strength after the 85/85 test was measured by the shear tensile strength test.
From the above-mentioned measured values of the bonding strength, the ratio of the bonding strength, that is, (the bonding strength after the 85/85 test) / the bonding strength immediately after production was determined. It can be said that the closer this ratio is to 1, the more the joint strength is maintained, that is, the deterioration of the joint strength with time is suppressed.
The results are shown in Table 2.

About the 85/85 test: Here, a test was conducted in which the joining member of the aluminum plate and the sheet made of PPS was stored in a tank having a temperature of 85 ° C. and a relative humidity of 85% for one week.

Shear tensile strength test: The shear tensile strength test in JIS K6850 was used as a reference. The shear tensile strength was calculated from the breaking force and the area of the clad layer for the joining member of the aluminum plate and the sheet made of PPS.

From the results shown in Table 2, when the cladding compositions of Examples 1, 2 and 3 to which the present invention was applied were used, when the cladding composition of Comparative Example 1 was used. In comparison, it can be confirmed that the decrease in the bonding strength after the 85/85 test is suppressed. In particular, when the cladding compositions of Examples 2 and 3 are used, it can be confirmed that the decrease in the bonding strength after the 85/85 test is remarkably suppressed.

<Evaluation (2)>
Further, the 85/85 test for 1000 hours was carried out in the same manner as above for the joining member of the aluminum plate and the sheet made of PPS produced by using each of the cladding compositions of Example 2 and Comparative Example 1. went.
Immediately after production, after 1 week, 2 weeks, 30 days, and 1000 hours, each joint strength was measured by a shear tensile strength test. This result is shown in FIG.

FIG. 1 is a graph showing the results of measuring the change over time in the bonding strength in the 85/85 test for the bonding members manufactured by using the cladding compositions of Example 2 and Comparative Example 1. The vertical axis represents the shear joint strength (MPa) measured by the shear tensile strength test, and the horizontal axis represents the elapsed time (days).

From the results shown in FIG. 1, when the cladding composition of Example 2 to which the present invention was applied was used, the bonding strength after 1000 hours in the 85/85 test was about 90% or more of the initial bonding strength. You can confirm that it is shown.
On the other hand, when the cladding composition of Comparative Example 1 was used, the bonding strength after 1000 hours in the 85/85 test was reduced to about one-third of the initial bonding strength.

From the above results, according to the cladding composition to which the present invention is applied, it is possible to stably bond the metal base material and the resin member and to suppress deterioration of the bonding strength between the metal base material and the resin member over time. It could be confirmed.
Further, it was confirmed that by applying the present invention, it is possible to manufacture a metal / resin bonding member in which deterioration of the bonding strength between the metal base material and the resin member with time in a specific environment is suppressed.

Claims (12)

It contains a first metal powder, a second metal powder, a binder, and an organic solvent.
The metal constituting the second metal powder is a metal having a lower corrosion potential than the metal constituting the first metal powder, and is a composition for cladding. The cladder according to claim 1, wherein the difference between the corrosion potential of the metal constituting the first metal powder and the corrosion potential of the metal constituting the second metal powder is 100 mV (vs. SHE) or more. Composition for ding. The cladding composition according to claim 1 or 2, wherein the second metal powder contains at least one selected from the group consisting of zinc powder and magnesium powder. The cladding composition according to any one of claims 1 to 3, wherein the first metal powder contains at least one selected from the group consisting of aluminum powder and titanium powder. The cladding composition according to any one of claims 1 to 4, wherein the content of the second metal powder is 0.5 to 10% by mass with respect to the total amount of the composition. The cladding composition according to any one of claims 1 to 5, wherein the content of the first metal powder is 25 to 95% by mass with respect to the total amount of the composition. The cladding composition according to any one of claims 1 to 6, wherein the content of the binder is 0.01 to 10% by mass with respect to the total amount of the composition. The cladding composition according to any one of claims 1 to 7, wherein the binder contains polyvinyl acetal. The cladding composition according to any one of claims 1 to 8, further comprising carbon powder. A method for manufacturing a metal / resin bonded member in which a metal base material and a resin member are bonded.
The step (i) of applying the cladding composition according to any one of claims 1 to 9 to at least a part of the metal substrate.
The step (ii) of irradiating the coated portion of the cladding composition on the metal substrate with a laser,
The step (iii) of arranging the resin member on the laser irradiation portion of the metal substrate and the interface between the laser irradiation portion and the resin member are heated to join the metal substrate and the resin member. Step (iv) and
A method for manufacturing a metal / resin joint member. The metal according to claim 10, wherein in the step (iv), the interface between the laser irradiation unit and the resin member is heated by irradiating the laser to join the metal base material and the resin member. / Manufacturing method of resin joint member. The metal / resin bonding member according to claim 10 or 11, wherein the first metal powder is a mixed metal powder of one or more metals that are the same as the metal constituting the metal base material and other metals. Production method.

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