JP7339514B2 - Composite, its manufacturing method, and painted metal plate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a composite, a manufacturing method thereof, and a coated metal sheet.

Composites containing a metal plate and a rubber layer joined thereto are widely used, for example, in anti-vibration rubber for automobiles, seismic isolation laminated rubber as building members, health care products, and the like.

For example, as a composite used for oil seals, Patent Document 1 discloses a metal plate, (a) an undercoat adhesive layer containing a phenolic resin and an epoxy resin, and (b) a phenolic resin, a halogenated polymer and a metal oxide. and (c) an acrylic rubber layer, in that order.

Such a composite is prepared by: 1) a step of cleaning or surface-treating the surface of a metal plate by shot blasting or the like; ) A step of applying and drying an undercoat vulcanizing adhesive to form an undercoat adhesive layer; A step of applying and drying the agent to form a topcoat adhesive layer, 4) Laminating an unvulcanized rubber composition on the obtained topcoat vulcanized adhesive layer, and thermocompression bonding with a hot press or the like, It is obtained by allowing the vulcanization of the unvulcanized rubber composition and the vulcanization of the undercoat adhesive layer and topcoat adhesive layer to proceed simultaneously to bond the metal plate and the rubber layer.

A vulcanizing adhesive used for bonding such a metal plate and a rubber layer usually contains a halogenated rubber such as chlorinated rubber or brominated rubber and a vulcanizing agent such as sulfur in order to improve adhesion. including. Examples of such vulcanizing adhesives include a one-layer vulcanizing adhesive that bonds the metal plate and the rubber layer with only one layer, an undercoat vulcanizing adhesive that is applied to the metal plate side, and an undercoat vulcanizing adhesive that is applied to the rubber layer side. There is also a two-layer vulcanizing adhesive that consists of two layers with a topcoat vulcanizing adhesive.

JP 2007-283527 A

However, the method as described above requires a large number of steps until the final composite is obtained, resulting in a problem of low productivity. In particular, it is desired that the above step 1) (the step of washing the surface of the metal plate) and the above step 2) (the step of forming the undercoat adhesive layer on the surface of the metal plate) can be omitted. .

That is, if there is a coated metal plate provided with an undercoat adhesive layer, the above step 3) (the step of forming the topcoat adhesive layer) and the above step 4) (a rubber layer is laminated on the topcoat adhesive layer and heated) A composite body in which the metal plate and the rubber layer are adhered can be obtained only by carrying out the step of crimping. Thus, in order to reduce the number of steps and increase productivity, it is desired to use a coated metal sheet provided with an undercoat adhesive layer (that is, precoating).

However, in a conventional painted metal sheet provided with a vulcanizing primer layer, the undercoat adhesive layer of the laminated painted metal sheet adheres to the back surface of the metal sheet during, for example, being wound into a coil and stored. In addition, there is a problem that the undercoat adhesive layers adhere to each other or crosslink each other (when the metal plate has undercoat adhesive layers on both sides), causing so-called blocking. Therefore, it is desired to obtain a composite having good adhesion between the coated metal sheet and the rubber layer without causing such blocking.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a composite having good adhesiveness, a method for producing the same, and a coated metal sheet used therein that does not cause blocking.

The present invention relates to the following composites, methods for producing the same, and coated metal sheets.

A composite of the present invention comprises a metal plate, a painted metal plate having a primer layer disposed on the metal plate, and a rubber layer disposed on the primer layer of the painted metal plate. The primer layer is made of a cured product of a resin composition containing a curable resin, a curing agent, and an aggregate of wet-process silica particles and substantially free of a rubber component, and the wet-process silica particles have an average The primary particle diameter is 10 to 60 nm, the average particle diameter of the aggregates is 0.1 to 1.0 μm, and the content of the wet silica particles is 3 to 25 with respect to the curable resin. % by mass.

The method for producing a composite of the present invention includes: 1) a curable resin, a curing agent, and an aggregate of wet silica particles, the average primary particle size of the wet silica particles being 10 to 60 nm, and the wet A step of obtaining a resin composition having a silica particle content of 3 to 25% by mass relative to the curable resin and substantially free of a rubber component; and 2) applying the resin composition to a metal plate. and then curing to obtain a coated metal plate having a primer layer made of a cured product of the resin composition; and a step of applying a resin composition for a rubber layer containing a cross-linking agent, followed by cross-linking to obtain a rubber layer.

A coated metal sheet of the present invention is a coated metal sheet to be bonded to a rubber layer, and has a metal sheet, a chemical conversion coating, and a primer layer in this order, and the chemical conversion coating is a chromate-based coating. or a chromate-free film containing a silane coupling agent having an amino group and an organic resin, wherein the primer layer is disposed on the outermost surface of the coated metal plate, and the primer layer is cured It consists of a cured product of a resin composition containing a curable resin, a curing agent, and an aggregate of wet silica particles and substantially free of a rubber component, and the wet silica particles have an average primary particle diameter of 10 to 60 nm. and the average particle size of the aggregate is 0.1 to 1.0 μm, and the content of the wet silica particles is 3 to 25% by mass with respect to the curable resin.

ADVANTAGE OF THE INVENTION According to this invention, the composite which has favorable adhesiveness, its manufacturing method, and the coated metal plate which does not produce blocking used for it can be provided.

FIG. 1 is a schematic cross-sectional view showing an example of the composite of the present invention. FIG. 2 is a schematic cross-sectional view showing another example of the composite of the present invention.

The present inventors have found that in a coated metal plate having a metal plate and a primer layer, the primer layer contains agglomerates of an appropriate size formed by aggregating wet-process silica particles having a small average primary particle size. It has been found that even if the rubber component is not substantially contained, it can be well adhered to a layer containing a rubber component (for example, a rubber layer).

In order to clarify the reason for this, the present inventors observed the state of adhesion at the interface between the primer layer and the rubber layer with a TEM, both when the primer layer contained aggregates and when it did not. As a result, when the primer layer does not contain aggregates, the interface between the primer layer and the rubber layer can be clearly confirmed, whereas when the primer layer contains aggregates, the interface between the primer layer and the rubber layer is clearly visible. It was found that it could not be clearly confirmed.

That is, when the rubber layer is formed by applying the rubber layer resin composition onto the primer layer, the aggregates contained in the primer layer permeate the rubber component contained in the rubber layer into the primer layer, and the aggregates It is considered that the particles are absorbed in minute voids. As a result, the rubber component absorbed in the voids of the aggregates remains in the aggregates even after drying and is vulcanized (cross-linked), resulting in strong adhesion between the primer layer and the rubber layer. It is thought that it will be expressed.

In this way, by using a coated metal plate having a primer layer that exhibits good adhesion to the rubber layer, the conventional step 1) (the step of washing or surface-treating the surface of the metal plate) or the step 2) ) (the step of forming the undercoat adhesive layer) can be omitted. That is, the complex can be obtained with a small number of steps. Furthermore, since the primer layer of the painted metal plate does not substantially contain a rubber component (for obtaining adhesion), for example, the primer layer of the painted metal plate and the Blocking, such as adhesion of the back surface of the metal plate and adhesion of the primer layers to each other, can be suppressed.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail.

1. Composite A composite of the present invention has a coated metal plate and a rubber layer disposed on the primer layer of the coated metal plate.

1-1. Painted Metal Plate The painted metal plate has a metal plate and a primer layer disposed on the metal plate. From the viewpoint of improving the adhesion between the metal plate and the primer layer, the coated metal plate preferably further has a chemical conversion film disposed between the metal plate and the primer layer. Moreover, from the viewpoint of highly suppressing corrosion of the metal plate, it is preferable to further have an antirust layer disposed between the chemical conversion film and the primer layer.

[Metal plate]
The type of metal plate is not particularly limited. Examples of metal sheets include cold-rolled steel sheets, galvanized steel sheets (electrical Zn-based plating, hot-dip Zn-based plating), and alloyed zinc-based steel sheets (alloyed hot-dip Zn-based plating obtained by alloying after hot-dip Zn-based plating). , zinc-based alloy plated steel sheets (hot-dip Zn-Mg-based plating, hot-dip Zn-Al-Mg-based plating, hot-dip Zn-Al-based plating), hot-dip Al-Si-based plated steel sheets, stainless steel sheets (austenite, martensite, ferrite ferrite-martensite two-phase system), aluminum plate, aluminum alloy plate, copper plate, brass plate, titanium plate, etc.

The metal plate may be subjected, if necessary, to a known pre-painting treatment such as degreasing, surface cleaning by corona discharge, or surface roughening by mechanical polishing, pickling, shot blasting, or the like.

The thickness of the metal plate can be appropriately set according to the application of the composite, and can be, for example, 0.2 to 2.0 mm when used as a vibration isolator.

[Chemical conversion coating]
The chemical conversion coating is arranged between the metal plate and the primer layer, and improves adhesion between the metal plate and the primer layer. The chemical conversion treatment film may be arranged at least on a region (joint region) to be joined to the rubber layer on the surface of the metal plate, but may be arranged on the entire surface of the metal plate.

The type of chemical conversion treatment film is not particularly limited, and may be a chromate film such as a chromate-based or chromate-phosphate-based film, or a chromate-free film. For example, from the viewpoint of reducing environmental load, the chemical conversion coating is preferably a chromate-free coating.

A chromate-free film contains an inorganic compound (not containing chromate) and an organic resin.

Examples of inorganic compounds include silane compounds (eg, silane coupling agents), titanium compounds (eg, Ti—Mo composites), fluoroacid compounds (eg, hexafluorotitanic acid), and zirconium compounds (eg, hexafluorozirconic acid). is included. These inorganic compounds may be used singly or in combination of two or more. Among them, the inorganic compound is preferably a silane compound, and more preferably a silane coupling agent from the viewpoint of easily increasing the adhesion between the metal plate and the primer layer.

The silane coupling agent preferably has an amino group, preferably a primary amino group, from the viewpoint of increasing the reactivity with the epoxy resin and curing agent contained in the primer layer, which will be described later. Examples of silane coupling agents include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-(2-aminoethyl)aminopropyltrimethoxysilane, N-(2-aminoethyl)aminopropylmethyl Dimethoxysilane, N-(2-aminoethyl)aminopropyltriethoxysilane, N-(2-aminoethyl)aminopropylmethyldiethoxysilane, N-(2-aminoethyl)aminopropylmethyldimethoxysilane, and the like.

The organic resin can enhance affinity with the resin contained in the primer layer and enhance adhesion between the chemical conversion film and the primer layer. Examples of organic resins include urethane resins, phenolic resins, N-methylglucamine resins, tannic acid and polyacrylic acid. These organic resins may be used singly or in combination of two or more. Moreover, these organic resins may be cured with a curing agent such as an isocyanate compound or a polycarbodiimide compound.

The adhesion amount of the chemical conversion coating is not particularly limited as long as it is within a range capable of improving the adhesion between the metal plate and the primer layer. For example, in the case of a chromate film, the deposition amount may be adjusted so that the total Cr-equivalent deposition amount is 5 to 100 mg/m ² . In the case of the chromate-free film, the coating amount containing the silane compound should be in the range of 10 to 300 mg/m ² , and the coating amount containing the titanium compound should be in the range of 10 to 500 mg/m ² . In the case of the fluoroacid-based film, the deposition amount may be adjusted so that the deposition amount in terms of fluorine or the deposition amount in terms of total metal elements is in the range of 3 to 100 mg/m ² .

[Antirust layer]
The anticorrosion layer is provided as a metal plate to improve corrosion resistance when it is necessary to protect the metal plate from corrosive environments such as salt damage, such as cold-rolled steel plate and plated steel plate.

The antirust layer is preferably made of a cured product of a resin composition containing a curable resin, a curing agent, and an antirust pigment.

Examples of the curable resin used for the anticorrosive layer include those similar to those exemplified as curable resins used for the primer layer to be described later. The curable resin used for the antirust layer and the curable resin used for the primer layer may be the same or different, and from the viewpoint of facilitating good adhesion to the primer layer, the same resin may be used. is preferred.

Examples of antirust pigments include chromium-based antirust pigments such as calcium chromate and strontium chromate; Contains rust pigments. These anticorrosive pigments may be of one type or may be a combination of two or more types.

The thickness of the antirust layer may be within a range that can impart sufficient corrosion resistance to the coated metal sheet, and is preferably 1 to 20 μm, more preferably 3 to 10 μm.

[Primer layer]
The primer layer is arranged on the metal plate as the outermost layer of the coated metal plate, and adheres (bonds) the metal plate and the rubber layer (or adhesive layer). From the viewpoint of improving the heat resistance of the resulting composite while improving the adhesion between the metal plate and the rubber layer (or adhesive layer), the primer layer contains a curable resin, a curing agent, and wet silica particles. It is preferably composed of a cured product of a resin composition containing an aggregate of

(Curable resin)
The curable resin is not particularly limited as long as it has a functional group (for example, a hydroxyl group) that reacts with the curing agent and has good adhesion to the chemical conversion coating. For example, when the chemical conversion coating contains a silane coupling agent having an amino group, the curable resin contained in the primer layer contains reactive groups (carboxyl group, ester group, epoxy group, ketone group, a halogen group, etc.). In addition, when the chemical conversion treatment film contains a silane coupling agent having an epoxy group, the curable resin contained in the primer layer is a resin having a functional group (carboxyl group, amino group, hydroxyl group, etc.) that can react with the epoxy group. is preferably Above all, good adhesion with the chemical conversion film is obtained from the viewpoint that it is easy to obtain good adhesion without peeling of the coating film during molding, or when the chemical conversion film contains a silane coupling agent having an amino group. The curable resin is preferably a curable polyester resin or an epoxy resin from the viewpoint of being easily cured.

The curable polyester resin is, for example, a hydroxyl group-containing polyester resin, which is a polycondensate of a polyhydric carboxylic acid component and a polyhydric alcohol component.

Examples of polycarboxylic acid components include aromatic polycarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid or its anhydride, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid and trimellitic acid. and anhydrides thereof, and aliphatic polycarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, butanetricarboxylic acid.

Examples of polyhydric alcohol components include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, 1,2- propanediol, neopentyl glycol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-pentanediol, 2,3-pentanediol, 1,4-pentanediol, 1 ,4-hexanediol, 2,5-hexanediol, 3-methyl-1,5-pentanediol, 1,2-dodecanediol, 1,2-octadecanediol, 1,4-cyclohexanediol, 1,4-cyclohexane Aliphatic polyhydric alcohols such as dimethanol, trimethylolpropane (TMP), pentaerythritol (PE), trimethylolethane (TME), erythritol, dipentaerythritol, sorbitol, glycerin;
Aromatic polyhydric alcohols such as bisphenol A alkylene oxide adducts and bisphenol S alkylene oxide adducts are included. The polyhydric alcohol component constituting the hydroxyl group-containing polyester resin preferably contains a trihydric or higher alcohol, and may further contain a dihydric alcohol.

Examples of curable polyester resins also include epoxy-modified polyester resins. The epoxy-modified polyester resin may be obtained, for example, by subjecting a carboxyl group-containing polyester resin and an epoxy compound to an esterification reaction.

The carboxyl group-containing polyester resin as a raw material can be a polycondensate of a polyhydric carboxylic acid component and a polyhydric alcohol component, as described above. However, it is preferable that the ratio of the polyhydric carboxylic acid component/polyhydric alcohol component is adjusted so that the number of carboxyl groups becomes a predetermined amount, or that the polyhydric carboxylic acid component contains a carboxylic acid having a valence of 3 or more. Moreover, the carboxyl group-containing polyester resin as a raw material may be obtained by reacting a hydroxyl group-containing polyester resin with an acid anhydride.

The curable polyester resin has an aromatic skeleton (the polyhydric carboxylic acid component contains an aromatic carboxylic acid component, or the polyhydric alcohol component contains an aromatic polyhydric including alcohol).

Although the number average molecular weight of the curable polyester resin is not particularly limited, it is preferably several thousand to several tens of thousands, specifically 3,000 to 15,000, from the viewpoint of the strength and workability of the coating film. Above all, the number average molecular weight is preferably as high as 5,000 from the viewpoint of increasing the flexibility of the primer layer, making it easier to swell with the oil in the rubber layer (or the solvent in the adhesive layer), and making it easier to improve adhesion. ~15000 is more preferred. The number average molecular weight of the curable polyester resin can be measured in terms of polystyrene by gel permeation chromatography. Specific measurement conditions can be the same as those in the examples described later.

Examples of epoxy resins include bisphenol type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin; phenol novolak type epoxy resin, ortho cresol novolak type epoxy resins, novolac-type epoxy resins that are polyglycidyl ethers of phenol or alkylphenol novolak resins such as bisphenol A novolac-type epoxy resins; Alkylene glycol-type epoxy resins which are polyglycidyl ethers of alkylene glycol such as 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, and pentaerythritol tetraglycidyl ether; diglycidyl orthophthalate, diglycidyl isophthalate, Glycidyl ester-type epoxies such as diglycidyl terephthalate, diglycidyl tetrahydrophthalate, diglycidyl hexahydrophthalate, diglycidyl succinate, diglycidyl adipate, diglycidyl sebacate, and diglycidyl dimer Resin; includes glycidylamine-type epoxy resins such as triglycidyl isocyanurate and tetraglycidyldiaminodiphenylmethane. Among them, an epoxy resin having an aromatic ring (aromatic epoxy resin) is preferable from the viewpoint of easily obtaining adhesion to a metal plate (or chemical conversion film) or easily obtaining a cured coating film with high strength or heat resistance. , bisphenol type epoxy resins are more preferred, and bisphenol A type epoxy resins are even more preferred.

Although the number average molecular weight of the epoxy resin is not particularly limited, it is preferably about several thousand from the viewpoint of the strength and workability of the coating film. Specifically, the epoxy resin preferably has a number average molecular weight of 400 to 25,000. When the number average molecular weight of the epoxy resin is 400 or more, it is easy to obtain a coating film with good strength, and it is easy to improve corrosion resistance. When the number average molecular weight of the epoxy resin is 25,000 or less, the viscosity of the coating solution does not become too high, so that the coating workability and workability with a roll coater or the like are less likely to be impaired. In addition, since the proportion of solids in the paint does not decrease too much, productivity is less likely to be impaired. Above all, from the viewpoint of increasing the flexibility of the primer layer, making it easier to swell with the oil in the rubber layer (or the solvent in the adhesive layer), and making it easier to improve adhesion, a higher number average molecular weight is preferable. More preferably, the resin has a number average molecular weight of 4,000 to 20,000. The number average molecular weight of the epoxy resin can be measured by the same method as described above.

The epoxy resin may also be a modified epoxy resin (such as an alkanolamine-modified epoxy resin) having a functional group that reacts with an isocyanate group, such as an amino group or a hydroxy group. Above all, from the viewpoint of increasing the affinity with the components contained in the chemical conversion film and the rubber layer and making it easier to obtain good adhesion, the epoxy resin should be a modified epoxy resin having a functional group that reacts with an isocyanate group. is preferred.

The content of the curable resin is preferably 55-88.5% by mass based on the solid content of the resin composition. When the content of the curable resin is 55% by mass or more, the resulting primer layer can not only have sufficient film strength, but also have good scratch resistance, corrosion resistance, water resistance or chemical resistance. I can. When the content of the curable resin is 88.5% by mass or less, the viscosity of the resin composition when forming the primer layer does not become too high, so that the coating workability and processability are less likely to be impaired. From the above viewpoint, the content of the curable resin is more preferably 60 to 85% by mass based on the solid content of the resin composition.

(curing agent)
The curing agent is not particularly limited as long as it can cure the curable resin. Examples of curing agents for curing epoxy resins include amine compounds, acid anhydrides and imidazole compounds. Examples of curing agents for modified epoxy resins and curable polyester resins having amino groups or hydroxyl groups as described above include isocyanate compounds and melamine compounds (methylated melamine compounds, butylated melamine compounds, methyl/ butylated melamine compounds).

Among them, an isocyanate compound is preferable from the viewpoint of imparting flexibility to the primer layer to easily suppress cracks and to easily enhance the adhesiveness to the rubber layer (or adhesive layer). A primer layer obtained by using an isocyanate compound as a curing agent tends to swell moderately due to the solvent in the adhesive layer and the oil in the rubber layer (compared to the case where a melamine-based curing agent is used, for example), and the condensation of wet silica particles does not occur. This is because the reaction points with aggregates are likely to increase.

Examples of isocyanate compounds include aliphatic isocyanate compounds such as hexamethylene diisocyanate (HDI), lysine diisocyanate, and dimer acid diisocyanate (DDI); Alicyclic isocyanate compound; Aromatic isocyanate compounds are included. Among them, aliphatic isocyanate compounds are preferable from the viewpoint of obtaining a primer layer having good adhesion.

The content of the curing agent is preferably 10 to 40% by mass with respect to the curable resin. When the content of the curing agent is 10% by mass or more, the curable resin can be sufficiently cured. As a result, a primer layer with sufficient film strength is easily obtained, and adhesiveness (or bondability) between the primer layer and the adhesive layer is easily obtained. When the content of the curing agent is 40% by mass or less, bleeding out is less likely to occur.

(Aggregate of wet silica particles)
Aggregates are aggregates of wet silica particles (primary particles). The average particle size of aggregates is preferably 0.1 to 1.0 μm. When the average particle size of the aggregates is 0.1 μm or more, there are many voids between the wet silica particles (primary particles) in the aggregates, and oil (or adhesion) when applying the rubber layer resin composition on the primer layer (Organic solvent used when the agent layer composition is applied) tends to be trapped. As a result, the primer layer is easily swollen, and good adhesion is easily obtained. When the average particle size of the aggregates is 1.0 μm or less, the voids between the wet silica particles in the aggregates are not too small, and the reaction points with the rubber-based polymer contained in the rubber layer (or adhesive layer) are increased. Since it does not become too small (it can be increased moderately), the interaction of the rubber layer (or adhesive layer) with the rubber-based polymer is less likely to be impaired. From the same viewpoint, the average particle size of the aggregates is more preferably 0.1 to 0.8 μm.

The average particle size of aggregates can be measured by the following procedure.
First, a cross section of the primer layer is observed with a scanning or transmission electron microscope at a magnification of 2,000 to 20,000. Next, in the obtained observation image, a 400 μm ² region containing many wet silica particle aggregates is selected, and the particle size of the wet silica particle aggregates in that region is measured. By averaging the diameters, the "aggregate average particle diameter" is obtained. In addition, the "particle diameter of the aggregate of particles" is determined by specifying the maximum diameter and the minimum diameter of one aggregate based on the scale displayed during electron microscope observation, and the particles of the aggregate based on the following formula. It can be obtained by calculating the diameter.
Formula: Aggregate particle size = (maximum diameter + minimum diameter) / 2

The average particle size of the aggregates can be adjusted by, for example, the average primary particle size of the particles constituting the aggregates, the type of curable resin to be combined, and the dispersion conditions (bead particle size in the crushing step described later, dispersion time, etc.). can. In order to increase the average particle size of the aggregates, for example, it is preferable to reduce the average primary particle size of the particles constituting the aggregates.

The average primary particle size of the wet silica particles forming the aggregates is preferably 10 to 60 nm. When the average primary particle diameter of the wet-processed silica particles is 60 nm or less, the specific surface area is large, and not only are the wet-processed silica particles easily agglomerated, but also there are many voids between the wet-processed silica particles. It tends to trap a large amount of oil (or an organic solvent during application of the adhesive layer composition) during application. As a result, the primer layer is easily swollen, and good adhesion is easily obtained. When the average primary particle diameter of the wet silica particles is 10 nm or more, the specific surface area is not too small and the voids between the wet silica particles are not too small, so the rubber polymer contained in the rubber layer (or adhesive layer) The number of reaction points with the rubber layer (or adhesive layer) does not become too small, and the interaction with the rubber-based polymer of the rubber layer (or adhesive layer) is less likely to be impaired. From the same viewpoint, the average primary particle size of the wet silica particles is more preferably 10 to 50 nm.

The average primary particle size of the wet silica particles is obtained by observing the cross section of the primer layer with a scanning or transmission electron microscope in the same manner as described above, and averaging the particle sizes of the 20 primary particles that constitute the aggregate of the wet silica particles. can be asked for.
Alternatively, the average primary particle size of the wet silica particles can be obtained by observing the particle sizes of any 20 particles separated and recovered from the primer layer with an electron microscope and calculating their arithmetic mean particle sizes. Separation and recovery of the wet silica particles from the primer layer are performed by, for example, dissolving the primer layer of the coated metal plate in an organic solvent that dissolves the curable resin constituting the primer layer, and then removing the separated wet silica particles. It can be done by filtering and drying.

The wet silica particles preferably have a specific surface area (nitrogen adsorption specific surface area) of 30 to 500 m ² /g. When the specific surface area of the wet silica particles is 10 m ² /g or more, the wet silica particles tend to aggregate moderately. Therefore, as described above, the oil content (or the adhesive layer composition (Organic solvent during application) is easily trapped, and good adhesion is easily obtained between the primer layer and the rubber layer (or adhesive layer). On the other hand, when the specific surface area of the wet silica particles is 500 m ² /g or less, the reaction points with the rubber layer (or adhesive layer) are not too small (because there are moderately many), so the rubber layer (or adhesive layer ) with the rubber-based polymer is less likely to be impaired. From the same viewpoint, the wet silica particles preferably have a specific surface area of 40 to 500 m ² /g.

The specific surface area (nitrogen adsorption specific surface area) of wet silica particles can be measured by the BET method in accordance with JIS Z 8830:2013. Specifically, the specific surface area of the wet silica particles is determined, for example, by dissolving the primer layer of the coated metal plate in an organic solvent that dissolves the curable resin constituting the primer layer, as described above, and then separating. After filtering and drying the wet silica particles, it can be determined by measuring the specific surface area of the obtained wet silica particles.

The type of wet silica particles is not particularly limited as long as the average primary particle size satisfies the above range. Wet silica particles are generally silica particles synthesized by a neutralization reaction between sodium silicate and sulfuric acid. Wet-process silica particles obtained by such a method can be produced by, for example, a direct method of decomposing sodium silicate directly with sulfuric acid; It can be manufactured by an indirect method, etc.

Wet silica particles can be distinguished from dry silica particles by the amount of silanol groups per unit area of the particle surface (SiOH density). Specifically, the SiOH density of the wet silica particles is preferably 5 particles/nm ² or more (eg, 5 to 7 particles/nm ² ). The SiOH density on the particle surface can be measured, for example, by reacting with LiAlH ₄ after drying at a pressure of 15 mmHg or less and a temperature of 120° C. for 3 hours.

Wet-process silica particles can be obtained by pulverizing wet-process silica as a raw material with a bead mill or the like. The wet-process silica used as a raw material may be a commercially available product, examples of which include Nipsil VN3 (manufactured by Nippon Silica Industry Co., Ltd.), Carplex CS-5 (manufactured by Shionogi Pharmaceutical Co., Ltd.), Starsil S (Kamishima Chemical Industry Co., Ltd.) Co., Ltd.), Tokusil US (manufactured by Tokuyama Co., Ltd.), Silton R-2 (manufactured by Mizusawa Chemical Industry Co., Ltd.), Vulkasil S (manufactured by Bayer AG (Germany)), etc., and have an average secondary particle size of 30 μm or less, Grades of 5 μm or less are preferably used.

The content of wet silica particles is preferably 3 to 25% by mass with respect to the curable resin contained in the primer layer. When the content of the particles is 3% by mass or more, the adhesion between the primer layer and the rubber layer (or adhesive layer) can be sufficiently enhanced, and the adhesion between the primer layer and the rubber layer (or adhesive layer) can be partially enhanced. Interfacial peeling between the layers can be made difficult to occur. When the content of the wet silica particles is 25% by mass or less, it is easy to prevent the primer layer from becoming brittle. As a result, cohesive failure of the primer layer during processing of the coated metal sheet can be easily suppressed, and deterioration of workability can be suppressed. From the above viewpoint, the content of the wet silica particles is preferably 4 to 20% by mass with respect to the curable resin contained in the primer layer.

Aggregates of wet silica particles may be uniformly present in the primer layer, or may be unevenly distributed in the thickness direction. From the viewpoint of enhancing the adhesion between the primer layer and the rubber layer (or adhesive layer), the aggregate of the wet silica particles should be contained in at least the rubber layer (or adhesive layer) side surface layer of the primer layer. Just do it.

Thus, the primer layer containing aggregates of wet-process silica particles has good adhesiveness to the rubber layer (or adhesive layer) without containing a rubber component unlike the conventional primer layer. Therefore, the primer layer can be substantially free of rubber components. Specifically, the content of the rubber component is 1% by mass or less, preferably 0.1% by mass or less, relative to the curable resin contained in the primer layer.

(other ingredients)
For the primer layer, if necessary, iron oxide, various baked pigments, coloring pigments such as cyanine blue and cyanine gray, extender pigments such as calcium carbonate, clay, barium sulfate, metal powder such as aluminum powder, bone agent, and antifoaming agent. , a leveling agent, a surface modifier, a viscosity modifier, a dispersant, a wax, an antirust pigment, and other components other than those mentioned above. Examples of other components may include rust-preventive pigments other than those described above, but they are not required when providing a rust-preventive layer between the primer layer and the metal plate. Among them, the primer layer preferably further contains an aggregate. This is because the addition of the aggregate tends to further increase the dispersibility of the aggregates of the wet silica particles.

About aggregate:
Aggregates can improve the film hardness and abrasion resistance of the primer layer, and can provide unevenness to the surface of the primer layer to improve the appearance. The aggregate may be an inorganic aggregate or an organic aggregate. The shape of the aggregate is not particularly limited, and may be scaly, fibrous, granular, or massive.

Examples of scale-like inorganic aggregates include glass flakes, barium sulfate flakes, graphite flakes, synthetic mica flakes, synthetic alumina flakes, silica flakes, mica-like iron oxide (MIO). Examples of fibrous inorganic aggregates include potassium titanate fibers, wollastonite fibers, silicon carbide fibers, alumina fibers, alumina silicate fibers, silica fibers, rock wool, slag wool, glass fibers, and carbon fibers. Examples of organic aggregates include acrylic particles, polyacrylonitrile particles. Examples of particulate or massive inorganic aggregates or matting agents include glass beads.

If the aggregate is granular, the average primary particle size can typically be greater than 100 nm. In the manufacturing process of the primer layer containing the aggregate, from the viewpoint of preventing fine particles due to pulverization (crushing) and maintaining the initial particle size of the aggregate, as described later, aggregates of wet silica particles After preparing the resin composition containing, it is necessary to add an aggregate and disperse it by disper stirring or the like.

(physical properties)
The thickness of the primer layer is not particularly limited as long as the metal plate (or chemical conversion film) and the rubber layer (or adhesive layer) can be sufficiently adhered.

From the above viewpoint, the thickness of the primer layer is preferably 1 to 30 μm. When the thickness of the primer layer is 1 μm or more, good adhesion to the rubber layer (or adhesive layer) is likely to be obtained. Moreover, when the thickness of the primer layer is 30 μm or less, the thickness of the coated metal sheet can be easily reduced. From the above viewpoint, the thickness of the primer layer is more preferably 3 to 20 μm, further preferably 5 to 10 μm. In addition, when the primer layer is composed of two or more layers, the thickness of the primer layer refers to the total thickness thereof.

The primer layer may be composed of one layer, or may be composed of two or more layers. For example, when the coated metal plate has an antirust layer, the primer layer is preferably composed of one layer. In addition, when the coated metal plate does not have an antirust layer, the primer layer is a first primer having a relatively low content of aggregates of wet silica particles disposed on the metal plate (or chemical conversion coating) side. and a second primer layer having a relatively high content of agglomerates of wet silica particles disposed on the rubber layer (or adhesive layer) side. The first primer layer may contain an antirust pigment from the viewpoint of enhancing the corrosion resistance of the metal plate.

1-2. Rubber Layer A rubber layer is placed on the primer layer of the painted metal sheet. The rubber layer is made of a cross-linked product of a resin composition for a rubber layer containing a first rubber-based polymer as raw materials and a first cross-linking agent.

(First rubber polymer)
The first rubber-based polymer is not particularly limited, and may be a diene-based polymer or a non-diene-based polymer.

Examples of diene polymers include butadiene rubber (BR), isoprene rubber (IR), isobutylene isoprene rubber (IIR), nitrile butadiene rubber (NBR), chloroprene rubber (CR), nitrile isoprene rubber (NIR), natural rubber (NR), vinyl pyridine butadiene rubber (PBR), styrene butadiene rubber (SBR), carboxystyrene isoprene rubber (XSBR), carboxy-nitrile butadiene rubber (XNBR). Among them, nitrile-butadiene rubber (NBR) and styrene-butadiene rubber (SBR) are preferred, and natural rubber (NR) and nitrile-butadiene rubber (NBR) are more preferred from the viewpoint of adhesion and versatility.

Examples of non-diene polymers include ethylene propylene diene rubber (EPDM), chlorosulfonated polyethylene (CSM), acrylic rubber (ACM), urethane rubber (U), silicone rubber (Q), epichlorohydrin rubber (ECO ) is included. Among them, ethylene propylene rubber (EPDM) is preferable from the viewpoint of versatility.

(First cross-linking agent)
The first cross-linking agent may be selected according to the type of the first rubber polymer as a raw material. Examples of the first cross-linking agent include sulfur (e.g. Hosoi Chemical Co., Ltd. fine powder sulfur 200 mesh), oxime compounds (e.g. dimethylglyoxime (DMG), diacetylmonoxime (DAM)), polyamine compounds (e.g. N,N' -dicinnamylidene-1,6-hexanediamine, hexamethylenediamine monocarbonate, 4,4'-methylenebis(cyclohexylamine) carbamate), organic peroxides (e.g. dicumyl peroxide, cumene hydroperoxide, p-methane hydroperoxide). oxide, 2,5-dimethylhexane-2,5-dihydroperoxide, di-t-butyl-peroxide, benzoyl peroxide, m-toluyl peroxide, 2,5-dimethyl-2,5-di(t- butylperoxy)hexane), polyol compounds (eg 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)perfluoropropane, hydroquinone).

Oxime compounds can be used as cross-linking agents for diene polymers such as isobutylene isoprene rubber (IIR), nitrile-butadiene rubber (NBR), and styrene-butadiene rubber (SBR). A polyamine compound can be used for a rubber-based polymer (CR, ACM, etc.) having a halogen atom serving as a cross-linking point. Organic peroxides can be used as cross-linking agents for many rubber-based polymers, except for some such as IIR. One type of cross-linking agent may be used, or two or more types may be used in combination.

The content of the first cross-linking agent is preferably, for example, 3 to 10% by mass with respect to the first rubber polymer as a raw material.

(other ingredients)
The rubber layer resin composition may further contain other components than those described above, if necessary. Examples of other ingredients include heat resistant rubber polymers, plasticizers, anti-aging agents, cross-linking accelerators, reinforcing agents, and the like.

About heat resistant rubber polymer:
The rubber layer resin composition may further contain a polymethylene chain-based rubber polymer as a heat-resistant rubber polymer. For example, a diene polymer containing many double bonds in its molecule has poor heat resistance. Thermal deterioration of the layer resin composition can be further suppressed.

The content of the polymethylene chain rubber polymer is preferably 0 to 60% by mass, more preferably 10 to 50% by mass, more preferably 15 to 35% by mass, relative to the first rubber polymer as a raw material. is more preferable.

About plasticizer:
Examples of plasticizers include stearic acid. One type of plasticizer may be used, or two or more types may be used in combination. The content of the plasticizer can be, for example, 0.5 to 4.0% by mass with respect to the first rubber polymer as a raw material.

About Anti-Aging Agents:
Examples of anti-aging agents include naphthylamine-based, diphenylamine-based, p-phenylenediamine-based, quinoline-based, hydroquinone derivatives, monophenol-based, polyphenol-based, thiobisphenol-based, hindered phenol-based, and phosphite-based esters. . One type of anti-aging agent may be used, or two or more types may be used in combination. The content of the anti-aging agent may be, for example, 0.5 to 8.0% by mass with respect to the first rubber polymer as a raw material.

About the cross-linking accelerator:
Examples of cross-linking accelerators include guanidine-based, aldehyde-amine-based, aldehyde-ammonia-based, thiazole-based, sulfenamide-based, thiourea-based, thiuram-based, dithiocarbamate-based, xanthate-based, and zinc oxide (zinc white). included. One type of vulcanization accelerator may be used, or two or more types may be used in combination. The content of the cross-linking accelerator may be, for example, 1.0 to 8.0% by mass with respect to the first rubber polymer as a raw material.

About reinforcement:
Examples of reinforcing materials include carbon black, silica, and the like. The content of the reinforcing material is preferably, for example, 10 to 60% by mass with respect to the first rubber polymer. Also, the total content of other components is preferably 30% by mass or less with respect to the rubber layer.

(physical properties)
Although the thickness of the rubber layer can be appropriately set according to the use of the composite, it is preferably 10 μm or more, for example, from the viewpoint of exhibiting sufficient rubber elasticity. When the thickness of the rubber layer is 10 µm or more, the anti-vibration property is easily exhibited. In addition, the thickness of the rubber layer does not need to be set to an upper limit, and may be, for example, 30 mm, as long as it is used for vibration isolation.

1-3. Other Layers The composite of the present invention may further have other layers such as an adhesive layer, if desired. For example, when the rubber layer is a rubber layer such as EPDM that is difficult to obtain adhesion to a primer layer, from the viewpoint of further increasing the adhesion between the primer layer and the rubber layer of the coated metal plate, the primer layer and the rubber layer A further adhesive layer may be disposed between the

[Adhesive layer]
The adhesive layer comprises a crosslinked product of an adhesive composition containing a second rubber polymer and a second crosslinking agent.

(Second rubber polymer)
Examples of the second rubber-based polymer used in the adhesive layer include those exemplified as the first rubber-based polymer used in the rubber layer. For example, when the first rubber polymer contained in the rubber layer is a diene polymer, the second rubber polymer contained in the adhesive layer is preferably a halogenated rubber polymer.

Examples of halogenated rubber-based polymers may be halides of the aforementioned diene-based polymers or non-diene-based polymers. Examples of such halogenated rubber-based polymers include polymers of dichlorobutadiene, polymers of brominated dichlorobutadiene, chloroprene rubber (CR), chlorosulfonated polyethylene (CSM), epichlorohydrin rubber (ECO), Included are brominated or chlorinated rubbers such as chlorinated polyethylene.

(Second cross-linking agent)
The second cross-linking agent can be sulfur or an organic oxide.

(other ingredients)
The adhesive composition may further contain other components such as metal oxides and phenolic resins, if necessary.

Metal oxides can function as coagents or fillers. Examples of metal oxides include titanium oxide, zinc oxide, magnesium oxide, calcium oxide, and the like. Among them, a mixture of titanium oxide and a divalent metal oxide is preferred.

The phenolic resin can have the function of increasing the adhesion between the primer layer and the rubber layer. Examples of phenolic resins include novolak-type phenolic resins and resol-type phenolic resins.

The adhesive composition may be one commercially available as a topcoat vulcanizing adhesive. Examples of such commercial products include Chemlok 210, 215, 607, 5150, 6108, 6110, 6125, 6225, XJ150, XJ551, XJ552, XJ549 from Lord Corporation.

(physical properties)
The thickness of the adhesive layer is not particularly limited as long as it can sufficiently bond the primer layer and the rubber layer. The thickness of the adhesive layer can be, for example, 5-50 μm. When the thickness of the adhesive layer is 5 μm or more, good adhesion between the primer layer and the rubber layer is likely to be obtained. Moreover, when the thickness of the adhesive layer is 30 μm or less, the thickness of the coated metal sheet can be easily reduced. From the above viewpoint, the thickness of the adhesive layer is more preferably 5 to 50 μm, further preferably 10 to 30 μm.

1-4. Layer Configuration FIG. 1 is a schematic cross-sectional view showing an example of the composite of the present invention.

As shown in FIG. 1, the composite 10 has a coated metal plate 20, an adhesive layer 30, and a rubber layer 40 in this order. The coated metal plate 20 has a metal plate 21, a chemical conversion film 22, and a primer layer 23 in this order. The primer layer 23 of the coated metal plate 20 and the rubber layer 40 are well adhered (or bonded) via the adhesive layer 30 . Note that the adhesive layer 30 may be omitted.

Then, the surface layer portion of the primer layer 23 including the adhesive surface with the adhesive layer 30 (rubber layer 40 when the adhesive layer 30 is not provided) is the solvent in the adhesive layer 30 (or the oil content in the rubber layer 40). ) is preferably swollen. Thereby, good adhesion to the adhesive layer 30 (or the rubber layer 40) is likely to be obtained. The swollen portion can be confirmed, for example, by observing a cross section of the primer layer 23 with a low-vacuum SEM.

FIG. 2 is a schematic cross-sectional view showing another example of the composite of the present invention. The composite 10 shown in FIG. 2 is constructed in the same manner as that of FIG. Such composites 10 may have higher corrosion resistance.

2. Method for producing a composite The method for producing a composite of the present invention comprises: 1) a step of obtaining the resin composition; 3) applying a resin composition for a rubber layer onto the primer layer of the obtained coated metal plate, followed by cross-linking to obtain a coated metal plate; and obtaining a bonded (bonded) rubber layer.

About Step 1) In this step, a resin composition containing a curable resin, a curing agent, and an aggregate of the wet-process silica particles and substantially free of a rubber component is prepared.

The method for preparing the resin composition is not particularly limited, but from the viewpoint of facilitating the formation of the aggregates, the raw material wet silica (coarse particles) is pulverized, and the average primary particle size is within the above range. It is preferable to include a step of obtaining particles (crushing step).

The raw material, wet-process silica, may be crushed together with other components (for example, a curable resin, a curing agent, etc.) or separately from the other components. That is, the step of crushing wet silica as a raw material (crushing step) and the step of mixing the crushed wet silica (wet silica particles) and other components (mixing step) may be performed simultaneously, or sequentially. You can go there on purpose. An example of performing the crushing step and the mixing step simultaneously (in one step) includes a method of crushing and mixing wet silica as a raw material and other components. In an example of sequentially performing the crushing step and the mixing step (in separate steps), after crushing the wet silica as a raw material to obtain wet silica particles, the obtained wet silica particles and other components are mixed. method.

For example, from the viewpoint of making the wet silica particles compatible with other components (especially curable resins) and easily forming aggregates of an appropriate size, the raw material wet silica is crushed and mixed with other components. It is preferable to prepare the resin composition through steps. In addition, when the resin composition further contains a component that should not be crushed, such as aggregate, a step of crushing wet silica as a raw material to obtain particles, and the obtained wet silica particles and, for example, aggregate You may prepare a resin composition through the process of stirring and mixing with another component. Note that crushing and mixing is mixing accompanied by pulverization by media, and stirring and mixing is mixing without pulverization by media.

Crushing means include, but are not limited to, bead mills and ball mills.

The mixing means is not particularly limited, but may be the same as the crushing means, or may be stirring means such as a disper.

Wet-process silica, which is a raw material, may repeat dispersion and agglomeration in the process of being crushed. Therefore, the crushing step is preferably carried out while measuring the average primary particle size of the wet silica particles and adjusting the crushing time so that the average primary particle size falls within the above range. Alternatively, the relationship between the crushing conditions (crushing time, etc.) and the average primary particle size of the wet silica particles may be confirmed in advance, and the crushing step may be performed while adjusting the crushing time based on the result.

Step 2) In this step, the obtained resin composition is applied onto a metal plate and then cured. Thereby, a coated metal plate having a primer layer made of a cured product of the resin composition is obtained. Each step will be described below using an example in which a coated metal sheet has a chemical conversion film.

First, a chemical conversion treatment liquid is applied to the surface of a metal plate to form a chemical conversion coating.

The above-mentioned metal plate can be used. The metal plate may be subjected, if necessary, to a known pre-painting treatment such as degreasing, surface cleaning by corona discharge, or surface roughening by mechanical polishing, pickling, shot blasting, or the like.

The chemical conversion treatment liquid is a solution containing the constituent components of the chemical conversion treatment film described above. For example, the chromate-free chemical conversion treatment liquid can be an aqueous solution containing the aforementioned inorganic compound and an organic resin. If necessary, the chemical conversion treatment liquid may further contain a small amount of alcohol, ketone, or cellosolve-based water-soluble organic solvent in addition to water.

The chemical conversion treatment liquid may further contain a curing agent for curing the organic resin, if necessary. Examples of curing agents include diisocyanate compounds having aromatic rings, isocyanate compounds such as aliphatic diisocyanate compounds, and polycarbodiimide compounds.

The solid content concentration of the chemical conversion treatment liquid is preferably 0.1 to 40% by mass. When the solid content concentration is 0.1% by mass or more, it is easy to obtain a sufficiently thick chemical conversion coating. On the other hand, when the solid content concentration is 40% by mass or less, the storage stability of the chemical conversion treatment liquid is less likely to be impaired. The pH of the chemical conversion treatment solution is preferably adjusted in the range of 3-12.

Then, the chemical conversion treatment solution is applied to the surface of the metal plate subjected to alkali degreasing by a roll coating method, a spray method, a curtain flow method, a spin coating method, a dip coating method, or the like, and dried at room temperature without washing with water. . Although it is possible to form a chemical conversion treatment film by drying at room temperature, it is preferable to shorten the drying time at a temperature of 50° C. or higher in consideration of continuous operation. However, from the viewpoint of reliably suppressing the thermal decomposition of the organic components contained in the chemical conversion film, the drying temperature is preferably 200° C. or less.

Next, the above-described resin composition (primer layer resin composition) is applied onto the obtained chemical conversion film of the metal plate, dried and baked to form a primer layer. When the resin composition for the primer layer contains a curing agent, the baking is performed under conditions that cure the resin composition. In addition, even if the resin composition is completely cured, the surface layer of the primer layer has polar groups derived from epoxy resin, etc., so the oil in the rubber layer (or the solvent in the adhesive layer) may cause Easy to swell.

When the curing agent is an isocyanate compound, the isocyanate compound in the resin composition for the primer layer should be blocked from the viewpoint of improving the storage stability (from the viewpoint of increasing the pot life of the composition for the primer layer). is preferred. As the blocking agent, for example, known ε-caprolactam, methyl ethyl ketone oxime and the like can be used.

The resin composition for the primer layer may further contain a solvent, if necessary, from the viewpoint of improving coating workability. Examples of solvents include alcohol solvents such as methanol, ethanol, isopropanol and 1-butanol, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, and benzene solvents such as xylene. These solvents may be used alone or in combination of two or more.

The method of applying the resin composition for the primer layer is not particularly limited, and may be appropriately selected from known methods.

The drying method of the resin composition for the primer layer is not particularly limited, and the solvent may be volatilized. For example, when the resin contained in the resin composition for the primer layer has a functional group that reacts with the curing agent, the drying temperature may be a temperature at which the solvent can be volatilized within a range in which the resin is not completely cured. The plate temperature reached is preferably 180 to 220° C., for example.

About the step 3) Next, on the primer layer of the obtained coated metal plate, a rubber layer resin composition containing the above-mentioned second rubber polymer and a second cross-linking agent is applied, and A layer made of a resin composition is formed. The rubber layer resin composition may be in the form of a sheet or in the form of a liquid.

The rubber layer resin composition may further contain a solvent. Examples of the solvent contained in the rubber layer resin composition include the same solvents as those contained in the primer layer composition.

When the rubber layer resin composition is liquid, the method for applying the rubber layer resin composition is not particularly limited, and may be, for example, a screen printing method, a roll coating method, a curtain flow method, or a dip coating method.

Next, the rubber layer resin composition applied onto the primer layer of the coated metal plate is crosslinked to obtain a rubber layer composed of a crosslinked product of the rubber layer resin composition.

Crosslinking of the rubber layer resin composition is preferably carried out by heating. The heating method is not particularly limited, but may be, for example, a thermocompression method.

The cross-linking temperature may be a temperature at which the first rubber polymer in the rubber layer resin composition is cross-linked, and may be, for example, 150 to 250° C., depending on the composition of the rubber layer resin composition. The cross-linking time can be, for example, about 2 to 15 minutes.

The pressure at the time of thermocompression bonding may be a level that allows the primer layer and the rubber layer to adhere sufficiently, and may be, for example, 10 to 30 MPa.

Other Steps The method for producing a composite of the present invention may further have other steps as necessary. For example, between step 2) and step 3), a step of 4) applying the adhesive composition described above to the primer layer to form a layer composed of the adhesive composition may be further performed. good too.

The adhesive composition may further contain a solvent as necessary. Examples of the solvent contained in the adhesive composition include those similar to those contained in the primer layer composition. Moreover, the method of applying the adhesive composition is not particularly limited, and may be the same as the method of applying the rubber layer resin composition described above.

In step 3) above, the rubber layer resin composition is applied onto the layer of the adhesive composition obtained in step 4), followed by drying and cross-linking. That is, since the adhesive composition often contains a solvent, it is preferable to crosslink the rubber layer resin composition while drying and crosslinking the adhesive composition.

Drying and crosslinking may be performed simultaneously or sequentially. From the viewpoint of facilitating sufficient adhesion of the primer layer and the rubber layer via the adhesive layer, drying and cross-linking are preferably performed sequentially. That is, after drying the adhesive composition (drying step), it is preferable to crosslink the adhesive composition and the rubber layer resin composition (crosslinking step).

The drying temperature may be any temperature at which the solvent in the adhesive composition can be volatilized, and is usually lower than the crosslinking temperature, such as room temperature to 80°C. The drying time can be, for example, about 2 to 15 minutes.

Moreover, in the cross-linking step, cross-linking of the adhesive composition can be performed together with cross-linking of the resin composition for the rubber layer. Thereby, the adhesion between the primer layer and the adhesive layer can be further enhanced.

3. Use of Composite The composite of the present invention can be used in various applications such as anti-vibration rubber for automobiles, seismic isolation laminated rubber as a building member, and health care products. Automotive anti-vibration rubber can be applied to all rubber/metal composite anti-vibration members, such as arm bushes and mounts. The construction members can be applied to all rubber/metal composite construction members, and examples thereof include bundles, receiving metals, hanging metals, construction gaskets, and the like. As health care products, it can be applied to all health care members that combine rubber and metal, and includes pedometers (registered trademark), thermometers, pulsometers, sphygmomanometers, and the like.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited by these examples.

1. Preparation of materials (1) Metal plate Metal plate M1: Zn-6%Al-3%Mg alloy-plated steel plate with a thickness of 0.5 mm and a coating amount per side of 90 g/m ² Metal plate M2: Cold-rolled with a thickness of 2.0 mm Steel plate Metal plate M3: Hot-dip Zn-plated steel plate with a thickness of 0.8 mm and a coating amount per side of 60 g/m ² Metal plate M4: Thickness of 1.0 mm and a coating amount per side of 45 g/m ² Alloyed hot-dip Zn plating obtained by alloying after Zn plating)
Metal plate M5: Hot dip Al-9% Si plated steel plate with a thickness of 0.8 mm and a coating amount per side of 60 g / m ² Metal plate M6: Stainless steel plate with a thickness of 0.5 mm Metal plate M7: Aluminum plate with a thickness of 1.5 mm Metal Plate M8: Aluminum alloy plate with a thickness of 2.0 mm Metal plate M9: Copper plate with a thickness of 1.0 mm Metal plate M10: Brass plate with a thickness of 1.0 mm Metal plate M11: Titanium plate with a thickness of 0.5 mm The surface of the metal plate was cleaned (hydrophilized) by rinsing with hot water and water after alkali degreasing or pickling immediately before the treatment.

(2) Chemical conversion solution <Preparation of chemical conversion solution C1>
A mixture of N-(2-aminoethyl)aminopropyltriethoxysilane and a urethane resin (mass ratio 6:4) was added to water in which 10% by mass of ethanol was dissolved, and the solid content concentration was 3% by mass. A treatment liquid C1 was obtained.

<Preparation of chemical conversion treatment liquid C2>
A coating type chromate treatment agent (Surfcoat NRC300, manufactured by Nippon Paint Co., Ltd.) was used.

<Preparation of chemical conversion treatment liquid C3>
Using pure water as a solvent, hexavalent chromium ions: 20 g/l, trivalent chromium ions: 20 g/l, phosphoric acid: 40 g/l, silica: 80 g/l, and polymethyl methacrylate: 40 g/l were added. An acid chromium salt-based chemical conversion treatment solution C3 was obtained.

<Preparation of chemical conversion treatment liquid C4>
20 g/L of Ti compound and 40 g/L of phenolic resin were added to pure water (solvent) to obtain chromate-free chemical conversion solution C4.

(3) Primer layer resin composition <Preparation of primer layer resin compositions 1 to 5, 7 to 21 and 25>
100 parts by mass of curable polyester 1 (number average molecular weight 12000), 10 parts by mass of an isocyanate compound (curing agent 1) obtained by blocking hexamethylene diisocyanate (HDI) with ε-caprolactam, and shown in Table 1 or 2 Raw materials for additive materials of types and amounts, mixed solvents (solvent naphtha coal tar naphtha: 30%, cyclohexanone: 30%, n-butanol: 5%, ethylene glycol monobutyl ether: 5%) were mixed in a bead mill (Mitsubishi FREQROL E500 ) at 25° C. (crushing and mixing 1) to obtain primer layer resin compositions 1 to 5, 7 to 21 and 25. The average primary particle size of the particles of the additive material after crushing and mixing was adjusted by adjusting the crushing time.

<Preparation of resin composition 6 for primer layer>
A primer layer resin composition 6 was obtained in the same manner as the primer layer resin composition 3, except that the mixture was not crushed and mixed by a bead mill but was stirred and mixed by a disper.

<Preparation of primer layer resin composition 22>
A primer layer resin composition 22 was obtained in the same manner as the primer layer resin composition 3, except that zinc oxide shown in Table 2 was used as the raw material of the additive material.

<Preparation of primer layer resin composition 23>
A primer layer resin composition 23 was obtained in the same manner as the primer layer resin composition 3 except that the additive material was changed to the chlorinated rubber shown in Table 2.

<Preparation of resin composition 24 for primer layer>
A primer layer resin composition 24 was obtained in the same manner as the primer layer resin composition 3 except that no additive material was added.

<Preparation of primer layer resin compositions 26 to 35>
Primer layer resin compositions 26 to 35 were obtained in the same manner as primer layer resin composition 3, except that the types of the curable resin and curing agent were changed as shown in Table 2.

<Preparation of resin composition 36 for primer layer>
Wet silica, which is the raw material of the additive material, is treated with a bead mill at 25 ° C. in the presence of a mixed solvent (solvent naphtha coal tar naphtha: 30%, cyclohexanone: 30%, n-butanol: 5%, ethylene glycol monobutyl ether: 5%). After crushing and mixing (crushing and mixing 2) with other components, a primer layer resin composition 36 was obtained in the same manner as the primer layer resin composition 3, except that the mixture was stirred and mixed with other components using a disper.

The compositions of the primer layer resin compositions 1 to 18 thus obtained are shown in Table 1, and the compositions of the primer layer resin compositions 19 to 36 are shown in Table 2. The average primary particle size and specific surface area in Tables 1 and 2 are values after crushing and mixing (or after stirring and mixing).

In addition, the abbreviations in the table indicate the following.
(Curable resin)
Curable polyester 1: hydroxy group-containing high molecular weight polyester resin (hydroxy group-containing aromatic polyester, number average molecular weight: 12000, Tg: 75 ° C.)
Curable polyester 2: hydroxy group-containing low molecular weight polyester resin (hydroxy group-containing aromatic polyester, number average molecular weight 3000, Tg: 65 ° C.)
Curable polyester 3: epoxy-modified polyester resin (epoxy-modified carboxy group-containing aromatic polyester, number average molecular weight 4000, Tg: 63° C.)
Curable polyester 4: Epoxy-modified high-molecular-weight polyester (epoxy-modified carboxy group-containing aromatic polyester, number average molecular weight: 14000, Tg: 70°C)
Epoxy 1: amine-modified epoxy resin (number average molecular weight: 5000, Tg: 60 ° C.)
Epoxy 2: amine-modified high molecular weight epoxy resin (number average molecular weight: 20000, Tg: 65 ° C.)

(curing agent)
Curing agent 1: isocyanate compound mainly composed of hexamethylene diisocyanate (HDI) and blocked with ε-caprolactam Curing agent 2: methylated melamine curing agent Curing agent 3: butylated melamine curing agent Curing agent 4: methyl/butyl melamine curing agent

(Particles used as raw materials)
Wet silica: CARPLEX CS-8 manufactured by Evonik Japan (average secondary particle size: 4.6 μm, average primary particle size: 100 nm, SiOH density: 6 particles/nm ² )
Zinc oxide: #3 manufactured by Sakai Chemical Industry Co., Ltd. (average secondary particle size: 4 μm)

The number average molecular weight of the resin contained in the resin composition for the primer layer, the average primary particle size and the specific surface area of the additive material were measured by the following methods.

(Number average molecular weight)
The number average molecular weight of the resin was measured by gel permeation chromatography. Specifically, it was measured under the following measurement conditions.
<Measurement conditions>
Eluent: THF
Flow rate: 1.0ml/min
Temperature: 40°C
Detector: Differential Refractometer

(Average primary particle size)
After the obtained resin composition for a primer layer was applied onto a glass plate, the dried coating film was observed with an electron microscope to measure the particle size of 20 arbitrary particles. The arithmetic mean particle size of them was taken as the "average primary particle size of the additive material".

(Specific surface area)
Particles were separated from the obtained resin composition for primer layer, and the specific surface area (nitrogen adsorption specific surface area) was measured by the BET method in accordance with JIS Z 8830:2013.

(4) Adhesive composition Adhesive composition A1: Chemlock 6125 manufactured by Lord Corporation (main component: chlorinated rubber, secondary component: sulfur (vulcanizing agent), zinc oxide (vulcanizing aid) and high boiling point solvent )
Adhesive composition A2: XJ551 manufactured by Lord Corporation (main component: chlorinated rubber, secondary component: sulfur (vulcanizing agent) and high boiling point solvent)

(5) Resin composition for rubber layer <Uncrosslinked rubber sheet R1>
NBR raw rubber: 100 parts by mass Carbon black (HAF): 50 parts by mass Naphthenic process oil: 20 parts by mass Stearic acid: 1 part by mass Zinc oxide (zinc oxide): 5 parts by mass Sulfur: 2 parts by mass Thiazole cross-linking accelerator: 2 parts by mass

<Uncrosslinked rubber sheet R2>
EPDM raw rubber: 100 parts by mass Carbon black (HAF): 50 parts by mass Naphthenic process oil: 20 parts by mass Stearic acid: 1 part by mass Zinc oxide (zinc oxide): 5 parts by mass Sulfur: 2 parts by mass Thiazole cross-linking accelerator: 2 parts by mass

2. Preparation and Evaluation of Composite <Preparation of Composite 1>
(1) Preparation of Coated Metal Plate A metal plate M1 (thickness 0.5 mm, zinc-6% aluminum-3% magnesium alloy-plated steel plate with a coating weight per side of 90 g/m ² ) was prepared, and the surface was degreased with alkali. After the chemical conversion treatment solution C1 prepared above was applied to the alkaline degreased surface of this metal plate by a bar coating method, it was dried to form a chemical conversion treatment film having a coating amount of 100 mg/m ² . Next, the primer layer resin composition 1 was applied onto the chemical conversion film by a bar coating method, and dried at a plate reaching temperature of 200° C. to form a primer layer with a thickness of 5 μm to obtain a coated metal plate.

(2) Preparation of composite 1 Next, on the primer layer of the obtained coated metal plate, the adhesive composition A1 (CHEMLOCK 6125 manufactured by LOAD) was applied as an adhesive composition by a bar coating method, and then heated to 80 ° C. and dried for 10 minutes to form a layer of the adhesive composition having a thickness of 10 μm. Then, after placing an uncrosslinked rubber sheet R1 having a thickness of 3 mm as a resin composition for a rubber layer on the layer made of the adhesive composition, a heat press is used at a temperature of 160° C. and a pressure of 200 kgf/cm ² for 15 times. The adhesive composition and the uncrosslinked rubber sheet R1 were each crosslinked by thermocompression bonding for a minute. As a result, a composite 1 having a laminated structure of coated metal plate/adhesive layer/rubber layer was obtained.

<Preparation of composites 2 to 53>
Composites 2 to 53 were obtained in the same manner as Composite 1, except that the type of coated metal plate was changed as shown in Tables 3 to 5.

<Production of Composite 54>
Composite 54 was obtained in the same manner as Composite 3 except that the types of adhesive composition and uncrosslinked rubber sheet were changed as shown in Table 5.

<Preparation of Composite 55>
(Resin composition for antirust layer)
A total of 15 parts by mass of aluminum dihydrogen tripolyphosphate, magnesium phosphate, magnesium hydrogen phosphate and zinc phosphate are blended with 100 parts by mass of epoxy 1 (main resin component) and mixed to obtain a resin composition for a rust preventive layer. got stuff

(Preparation of complex)
Then, the resin composition for the antirust layer was applied between the chemical conversion film and the primer layer, dried and cured to form a 5 μm thick antirust layer, and the same procedure as in the coated metal plate 3 was performed. to obtain a coated metal plate. A composite 55 was obtained in the same manner as composite 3, except that this coated metal plate was used.

<Evaluation>
The anti-blocking property of the obtained coated metal sheet, the average particle size of aggregates in the primer layer, and the adhesiveness of the composite were evaluated by the following methods.

(Blocking resistance)
The painted metal plate was cut into a size of 50 mm x 50 mm to obtain two test pieces. The two sample pieces were laminated so that the coated film surfaces were in contact with each other, and held for 24 hours under a temperature of 50° C. and a pressure of 2 MPa. After that, the adhesion state (presence or absence of blocking) of the two sample pieces was visually observed and evaluated based on the following criteria.
◯: No blocking occurred ×: Blocking occurred If ◯, it was judged to be good.

(Average particle size of aggregates)
The average particle size of aggregates of particles contained in the primer layer of the coated metal plate was observed with a scanning electron microscope at a magnification of 2,000 to 20,000. A region of 400 μm ² containing many particle aggregates is selected from the obtained observation image, the particle size of the particle aggregates in that region is measured, and the particle sizes of 20 aggregates are averaged to obtain “ "Average particle diameter of aggregates".
In addition, the "particle diameter of the aggregate of particles" is determined by specifying the maximum diameter and minimum diameter of one aggregate from the scale displayed during electron microscope observation, and calculating the particle diameter of the aggregate based on the following formula. It was obtained by calculating
Formula: Aggregate particle size = (maximum diameter + minimum diameter) / 2

(Adhesiveness)
The adhesion between the primer layer/adhesive layer of the resulting composite is 90 degrees in accordance with JIS K6854-1: 1999 (adhesive-peeling adhesive strength test method-Part 1: 90 degree peeling). Measured by a peel test. The 90-degree peel test was performed using a test piece having a width of 25 mm and a length of 150 mm at a tensile speed (moving speed) of 50 mm/min. Then, the adhesiveness was evaluated based on the following criteria.
◎: 90% or more of the peeled interface is cohesive (internal) failure of the rubber layer, and the rest is interfacial failure of the primer layer / adhesive layer, and extremely excellent adhesion ○: 70% or more and less than 90% of the peeled interface is cohesive (internal) failure of the rubber layer, and the other is interfacial failure of the primer layer / adhesive layer, excellent adhesion △: Less than 70% of the peeled interface is cohesive (internal) failure of the rubber layer, Others are interfacial failure of the primer layer/adhesive layer, and the adhesion is poor. x: All peeled interfaces are interfacial failure of the primer layer/adhesive layer, and the adhesion is poor.

Table 3 shows the evaluation results of composites 1 to 25, Table 4 shows the evaluation results of composites 26 to 40, and Table 5 shows the evaluation results of composites 41 to 55.

As shown in Tables 3 to 5, none of the coated metal plates other than coated metal plate 23 caused blocking. Moreover, it can be seen that all of the composites of the present invention have good adhesiveness.

It is also found that the higher the molecular weight of the resin contained in the primer layer, the higher the adhesiveness (comparison between composites 3 and 26). This is presumably because resins with higher molecular weights have higher flexibility in the resulting primer layer and tend to swell with the solvent of the adhesive layer.

It is also found that the use of an isocyanate compound as the curing agent further increases the adhesiveness (comparison of composites 3 and 35 to 39). This is probably because the isocyanate compound gives a primer layer with higher flexibility and is easily swollen by the solvent of the adhesive layer.

In addition, the thickness of the primer layer (comparing composites 3 and 31 to 34), the type of chemical conversion coating (comparing composites 3 and 51 to 53), or the type of metal plate (composites 3 and 41 to 50) It can be seen that good adhesiveness can be obtained even if the (comparison) is changed. Also, it can be seen that good adhesion can be obtained even if the type of rubber is changed (comparison between composites 3 and 54).

In addition, when composites 3 and 55 were evaluated for adhesion and corrosion resistance (JIS-Z2371 compliant, corrosion resistance in a 35°C 5% NaCl salt spray test), composite 55 was as good as composite 3. It was confirmed that while having adhesiveness, it had higher corrosion resistance than Composite 3.

On the other hand, as shown in Table 3, composite 24 in which the primer layer does not contain aggregates of wet silica particles, composite 5 in which the average particle size of the aggregates contained in the primer layer is outside the range of the present application, and No. 6 does not provide sufficient adhesiveness. On the other hand, it can be seen that the composite 24 containing the rubber component instead of the aggregate of wet silica particles has relatively good adhesiveness, but causes blocking.

Moreover, as shown in Table 3, it can be seen that composites 19 and 20, in which the content of wet silica particles contained in the primer layer exceeds 25% by mass relative to the resin, cannot be made into a paint in the first place. On the other hand, composites 7, 11 and 15 in which the content of wet-process silica particles contained in the primer layer is less than 3% by mass relative to the resin do not exhibit sufficient adhesiveness.

ADVANTAGE OF THE INVENTION According to this invention, the composite which has favorable adhesiveness, its manufacturing method, and the coated metal plate which does not produce blocking used for it can be provided.

REFERENCE SIGNS LIST 10 composite 20 coated metal plate 21 metal plate 22 chemical conversion coating 23 primer layer 24 antirust layer 30 adhesive layer 40 rubber layer

Claims (18)

A composite comprising a painted metal plate having a metal plate and a primer layer disposed on the metal plate, and a rubber layer disposed on the primer layer of the painted metal plate,
The primer layer is made of a cured product of a resin composition containing a curable resin, a curing agent, and an aggregate of wet silica particles, and substantially free of a rubber component,
The curable resin is a curable polyester resin or epoxy resin,
The wet silica particles have an average primary particle size of 10 to 60 nm, and the aggregates have an average particle size of 0.1 to 1.0 μm,
The content of the wet silica particles is 3 to 25% by mass with respect to the curable resin,
The thickness of the primer layer is 1 to 20 μm,
Complex. The wet silica particles have a specific surface area of 30 to 500 m ² /g.
A composite according to claim 1 . The curing agent is an isocyanate compound,
A composite according to claim 1 or 2 . The isocyanate compound is an aliphatic isocyanate,
A composite according to claim 3 . The rubber layer is a crosslinked product of a rubber layer resin composition containing a first rubber polymer and a first crosslinking agent,
It further has an adhesive layer disposed between the primer layer and the rubber layer and made of a crosslinked product of an adhesive composition containing a second rubber polymer and a second crosslinking agent.
The complex according to any one of claims 1-4 . The coated metal plate further includes a chemical conversion coating made of a chromate-based coating or a chromate-free coating containing a silane coupling agent having an amino group and an organic resin, disposed between the metal plate and the primer layer. have
A complex according to any one of claims 1-5 . The thickness of the primer layer is 3 to 20 μm,
A complex according to any one of claims 1-6 . 1) Contains a curable resin, a curing agent, and an aggregate of wet silica particles, the curable resin is a curable polyester resin or an epoxy resin, and the average primary particle size of the wet silica particles is 10 to 60 nm. and the content of the wet silica particles is 3 to 25% by mass with respect to the curable resin, and obtaining a resin composition substantially free of a rubber component;
2) a step of applying the resin composition onto a metal plate and then curing the resin composition to obtain a coated metal plate comprising a cured product of the resin composition and having a primer layer with a thickness of 1 to 20 μm ;
3) a step of applying a rubber layer resin composition containing a first rubber-based polymer and a first cross-linking agent onto the primer layer of the coated metal plate, followed by cross-linking to obtain a rubber layer;
having
A method for manufacturing a composite. The step 1) is
A step of crushing wet-process silica as a raw material to obtain wet-process silica particles having the average primary particle size,
A method for producing the composite according to claim 8 . The wet silica particles have a specific surface area of 30 to 500 m ² /g.
A method for producing the composite according to claim 8 or 9 . The curing agent is an isocyanate compound,
A method for producing the composite according to any one of claims 8 to 10 . The isocyanate compound is an aliphatic isocyanate,
A method for producing the composite according to claim 11 . 4) further comprising the step of applying an adhesive composition containing a second rubber polymer and a second cross-linking agent onto the primer layer to form a layer composed of the adhesive composition;
In the step 3), the rubber layer resin composition is applied onto the layer made of the adhesive composition.
A method for producing the composite according to any one of claims 8 to 12 . A painted metal plate for bonding with a rubber layer, comprising:
Having a metal plate, a chemical conversion coating, and a primer layer in this order,
The chemical conversion coating is a chromate-based coating or a chromate-free coating containing a silane coupling agent having an amino group and an organic resin,
The primer layer is arranged on the outermost surface of the coated metal plate,
The primer layer is made of a cured product of a resin composition containing a curable resin, a curing agent, and an aggregate of wet silica particles, and substantially free of a rubber component,
The curable resin is a curable polyester resin or epoxy resin,
The wet silica particles have an average primary particle size of 10 to 60 nm, and the aggregates have an average particle size of 0.1 to 1.0 μm,
The content of the wet silica particles is 3 to 25% by mass with respect to the curable resin,
The thickness of the primer layer is 1 to 20 μm,
Painted metal plate. The wet silica particles have a specific surface area of 30 to 500 m ² /g.
A coated metal sheet according to claim 14 . The curing agent is an isocyanate compound,
A coated metal sheet according to claim 14 or 15 . The isocyanate compound is an aliphatic isocyanate,
17. A coated metal sheet according to claim 16 . The thickness of the primer layer is 3 to 20 μm,
The coated metal sheet according to any one of claims 14-17 .

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