KR20240037880A - Laminates and electronic devices having laminates - Google Patents

Abstract

A laminate capable of maintaining adhesion of a plating layer not only in its original state but also after a long-term heat resistance test is provided. A laminate is provided sequentially with a support, a primer layer, a metal particle layer, and a metal plating layer on the support, wherein the primer layer contains a phenoxy resin having a weight average molecular weight of 10,000 to 100,000.

Description

Laminates and electronic devices having laminates

The present invention relates to a laminate, and more specifically, to a laminate that can be suitably used in electronic devices such as electromagnetic wave shields, printed wiring boards, integrated circuits, and organic transistors, and to electronic devices using the same.

As electronic devices become smaller and faster, there is a demand for faster and higher performance printed wiring boards. In order to meet this demand, printed wiring boards with a smooth surface and a sufficiently thin conductive layer (metal layer) are required. Additionally, a flexible copper clad laminate (hereinafter abbreviated as “FCCL”) is known as a component of this printed wiring board. FCCL is mainly manufactured by bonding a heat-resistant polymer film and copper foil with an epoxy resin adhesive.

In FCCL using copper foil, an epoxy resin-based adhesive is applied to the surface while the copper foil wound in a roll is pulled out, and the copper foil is further bonded to the polymer film, so the copper foil cannot be sufficiently thin for handling purposes. In addition, it is necessary to roughen the surface of the copper foil to increase adhesion to the polymer film, and to achieve high density and high performance of printed wiring boards, transmission loss is required in the frequency (GHz band) and high transmission speed (several tens of Gbps) regions. There was a problem that caused .

Meanwhile, as a method of thinning the copper layer of FCCL, a metal thin film is formed on the surface of the polymer film by deposition or sputtering, and then the metal thin film is formed by electrolytic copper plating, electroless plating, or a combination of both. Methods for forming copper have conventionally been proposed (for example, Patent Document 1). However, in this method, since a vapor deposition or sputtering method is used to form a metal thin film, large-scale vacuum equipment is required, and there is a problem in that the size of the base material is limited due to the equipment.

In addition, as another method of thinning the copper layer of FCCL, for example, Patent Document 2 discloses that the plating base layer provided between the support and the metal plating layer includes inorganic nanoparticles, a phthalocyanine-based ligand, and a solvent (dispersion medium). It has been proposed to use the composition to improve the adhesion between the support and the plating layer. In addition, Patent Document 3 states that by providing a layer containing a compound having an aminotriazine ring as a primer layer on a support and providing a metal nanoparticle layer on the primer layer, the adhesion between the support and the metal plating layer is improved. It is proposed. In addition, Patent Document 4 proposes that the adhesion between the support and the plating layer is improved by interposing a metal particle layer containing metal particles and a reaction product of a specific epoxy compound and blocked polyisocyanate between the support and the plating layer.

Japanese Patent Publication No. 2015-118044 Japanese Patent Publication No. 2017-218664 International Publication No. 2019/013038 Pamphlet Japanese Patent Publication No. 2020-59185

All of the laminated structures proposed in the above-mentioned Patent Documents 1 to 4 improve the adhesion between the support and the plating layer in a room temperature environment in the normal state, that is, after formation of the plating layer. However, this time, the present inventors conducted a long-term heat resistance test at, for example, 150°C for 300 hours, and found that even if the adhesive had excellent adhesion in the original state, a new problem existed that the adhesion was significantly reduced after the long-term heat resistance test. It turned out.

Therefore, the object of the present invention is to provide a laminate that can maintain the adhesion of the plating layer not only in the normal state but also after a long-term heat resistance test.

In relation to the above problem, the present inventors have found that by using a high molecular weight phenoxy resin in the primer layer, the elongation of the primer layer can be increased and the elastic modulus can be further improved, thereby improving the adhesion of the plating layer immediately after plating (state). I gained knowledge. In addition, it was discovered that by using a high molecular weight phenoxy resin, deterioration such as decomposition of the polymer in the primer layer was suppressed during the long-term heat resistance test, and thus the adhesion of the plating layer could be maintained even after the long-term heat resistance test. The present invention was completed based on this knowledge. That is, the gist of the present invention is as follows.

[1] A laminate comprising a support and a primer layer, a metal particle layer, and a metal plating layer sequentially on the support, wherein the primer layer contains a phenoxy resin having a weight average molecular weight of 10,000 to 100,000.

[2] The laminate according to [1], wherein the primer layer further contains an epoxy resin.

[3] The laminate according to [2], wherein the primer layer contains the phenoxy resin and the epoxy resin in a ratio of 90:10 to 10:90 on a mass basis.

[4] The laminate according to any one of [1] to [3], wherein the primer layer further contains a compound having an aminotriazine ring.

[5] The laminate according to [4], wherein the compound having the aminotriazine ring is an aminotriazine-modified novolak resin.

[6] The laminate according to any one of [1] to [5], wherein the metal particle layer contains metal particles and a compound having a cationic group.

[7] The laminate according to [6], wherein the compound having the cationic group is a compound having a basic nitrogen atom-containing group.

[8] The laminate according to any one of [1] to [7], wherein the support is made of a flexible resin material.

[9] The laminate according to any one of [1] to [8], which is used in electronic devices.

[10] The laminate according to [9], wherein the electronic device is selected from a printed wiring board and an electromagnetic wave shield.

[11] An electronic device including the laminate according to any one of [1] to [10].

According to the present invention, in a laminate sequentially provided with a support, a primer layer, a metal particle layer, and a metal plating layer, a phenoxy resin with a weight average molecular weight of 10,000 to 100,000 is used as the primer layer, thereby enabling heat resistance testing not only in the normal state but also in long-term heat resistance tests. Even later, the adhesion of the metal plating layer can be maintained.

[Laminate]

The laminate according to the present invention includes a support, and on the support, a primer layer, a metal particle layer, and a metal plating layer in that order. Hereinafter, each element constituting the laminate of the present invention will be described.

<Support>

As the support, any material that has the mechanical strength to sequentially stack the primer layer, metal particle layer, and metal plating layer described later can be used without particular restrictions, for example, polyimide resin, polyamideimide resin, poly Amide resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin, polycarbonate resin, acrylonitrile-butadiene-styrene (ABS) resin, polystyrene, cycloolefin polymer, liquid crystal polymer, polyether ether ketone, Acrylic resins such as polyphenylene sulfide resin, polyphenylene sulfone, polyphenylene ether, and poly(meth)methyl acrylate, polyvinylidene fluoride resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl alcohol resin, and polyethylene resin. , polypropylene resin, urethane resin, silicon, silicon carbide, gallium nitride, sapphire, ceramics, glass, glass epoxy resin, glass polyimide, paper phenol, diamond-like carbon, alumina, polyester fiber, polyamide fiber, polyaramid fiber. These include synthetic fibers such as synthetic fibers, inorganic fibers such as carbon fiber, and natural fibers such as cellulose nanofibers. These supports are preferably insulating, and porous ones can be used. Additionally, the support may contain a single material or may be a laminate of multiple materials.

Additionally, as the support, a substrate containing, for example, synthetic fibers such as polyester fibers, polyamide fibers, and aramid fibers, and natural fibers such as cotton and hemp, may be used. The fiber may have been previously processed.

As the support, a support containing polyimide resin, polyethylene terephthalate, polyethylene naphthalate, glass, cellulose nanofiber, etc., which are often used as a support when forming conductive patterns such as electric circuits, is preferred.

Among the above, the support preferably contains a flexible resin material in order to provide flexibility to the laminate and obtain a final product that can be bent. Specifically, it is preferable that it is in the form of a film or sheet formed by uniaxial or biaxial stretching. Examples of the film-shaped or sheet-shaped support include polyimide film, polyethylene terephthalate film, polyethylene naphthalate film, and polybutylene terephthalate film.

When the shape of the support is film or sheet, the thickness is not particularly limited, but considering flexibility and bendability, it is usually about 1 to 5,000 ㎛, more preferably 1 to 500 ㎛, and 1 to 200 ㎛. It is more preferable.

In order to further increase adhesion to the primer layer described later, the surface of the support may, if necessary, be treated to form fine irregularities without losing smoothness or to introduce functional groups such as hydroxyl, carbonyl, and carboxyl groups. do. For example, methods such as plasma discharge treatment such as corona discharge treatment, dry treatment such as ultraviolet treatment, and wet treatment using water, an aqueous solution such as an acid or an alkali, or an organic solvent, etc. can be mentioned.

<Primer layer>

The primer layer has the function of improving the adhesion between the support described above and the metal particle layer described later. In the present invention, the primer layer contains as an essential component a phenoxy resin having a weight average molecular weight in the range of 10,000 to 100,000. In the present invention, by using a high molecular weight phenoxy resin in the primer layer, the elongation of the polymer can be improved and the elastic modulus can be further improved, thereby improving the adhesion between the support and the metal plating layer. In addition, by using a high molecular weight phenoxy resin, deterioration such as decomposition of the polymer due to heat during the long-term heat resistance test can be suppressed, so the adhesion of the metal plating layer can be maintained even after the long-term heat resistance test.

Phenoxy resin is a polyhydroxypolyether obtained by reacting a dihydric phenol compound with epichlorohydrin, or by reacting a dihydric epoxy compound with a dihydric phenol compound. Bisphenols are examples of divalent phenol compounds. Examples of the phenoxy resin include a phenoxy resin with a bisphenol A structure (skeleton), a phenoxy resin with a bisphenol F structure, a phenoxy resin with a bisphenol S structure, a phenoxy resin with a bisphenol M structure, and a bisphenol P structure. A phenoxy resin having a , a phenoxy resin having a bisphenol Z structure, etc. can be mentioned. In addition, phenoxy resins having skeletal structures such as novolak structure, anthracene structure, fluorene structure, dicyclopentadiene structure, norbornene structure, naphthalene structure, biphenyl structure, and adamantane structure can be mentioned. . These phenoxy resins may be used individually, or two or more types may be mixed. Among these, those having a bisphenol structure are preferable, and bisphenol A skeleton, bisphenol F skeleton, and bisphenol S skeleton are more preferred. Additionally, the terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group.

In the present invention, the weight average molecular weight of the phenoxy resin used is in the range of 10,000 to 100,000. If the molecular weight is 10,000 or more, the plating adhesion after a long-term heat resistance test increases, and if the molecular weight is 100,000 or less, the solubility in organic solvents improves and the coating solution viscosity when forming the primer layer becomes appropriate, thereby improving handling. The preferred weight average molecular weight of the phenoxy resin is 20,000 to 50,000, more preferably 22,000 to 50,000. Additionally, the weight average molecular weight of the phenoxy resin can be adjusted by the molar ratio or reaction time of the epoxy resin and phenol resin in the above reaction. In addition, in this specification, the weight average molecular weight was measured by gel permeation chromatography (GPC) described later and converted to standard polystyrene. For GPC measurement, a high-speed GPC device (HLC-8420GPC, manufactured by Tosoh Corporation) is used as the measuring device, and TSKgelG5000HxL/G4000HxL/G3000HxL/G2000HxL (manufactured by Tosoh Corporation) are used in series as columns. Tetrahydrofuran was used as an eluent, and measurement was performed using an RI detector. In addition, a phenoxy resin generally means a high molecular weight epoxy resin, but in this specification, “epoxy resin” means a weight average molecular weight of less than 10,000, and is distinguished from the above-mentioned phenoxy resin. do.

As the above-mentioned phenoxy resin, commercially available ones may be used, for example, 1256, 4250 (all phenoxy resins containing bisphenol A skeleton), 4275 (bis A/bis F mixed type), YL6794, manufactured by Mitsubishi Chemical Corporation. YL7213, YL7290, YL7482, YL7553, YX8100 (phenoxy resin containing bisphenol S skeleton), YP-70 (bisphenol F type phenoxy resin), ZX-1356-2 (phenoxy resin containing bisphenol A and bisphenol F skeleton), YPB-40PXM40 (phenoxy resin containing bromine), ERF-001M30 (phenoxy resin containing phosphorus resin), FX-280, FX-293, FX-310 (phenoxy resin containing a fluorene skeleton), PKHA, PKHB, PKHB+, PKHC, PKHH, PKHJ, PKFE, etc. manufactured by Gabriel Phenoxies.

In the present invention, it is preferable that the primer layer contains an epoxy resin in combination with the phenoxy resin described above. By using a phenoxy resin and an epoxy resin together, the adhesion of the metal plating layer is further improved as-is and after a long-term heat resistance test.

As the epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, cresol novolak type epoxy resin, phenol novolak type epoxy resin, bisphenol A novolak type epoxy resin, alcohol ether type epoxy resin, Tetrabromobisphenol A-type epoxy resin, naphthalene-type epoxy resin, phosphorus-containing epoxy compound having a structure derived from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide derivative, dicyclopentadiene derivative Examples include epoxy resins with derived structures and epoxidized products of fats and oils such as epoxidized soybean oil. These epoxy resins may be used individually, or two or more types may be used in combination.

Epoxy resins used in combination with phenoxy resins include bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, biphenyl-type epoxy resins, cresol novolak-type epoxy resins, and phenol epoxy resins, since they can further improve the adhesion of the metal plating layer. Aromatic epoxy resins such as rockfish-type epoxy resin and bisphenol A novolak-type epoxy resin are preferable, and bisphenol A-type epoxy resin is especially preferable.

The epoxy equivalent of the epoxy resin is preferably 100 to 5,000 g/equivalent, more preferably 120 to 2,000 g/equivalent, and even more preferably 120 to 250 g/equivalent, since adhesion can be further improved. .

When an epoxy resin is further included in addition to the phenoxy resin in the primer layer, the mixing ratio of the phenoxy resin and the epoxy resin is preferably 90:10 to 10:90, and 85:15 to 15:80 on a mass basis. It is more preferable to be

Furthermore, in the present invention, it is preferable that the primer layer contains a compound having an aminotriazine ring. The compound having an aminotriazine ring may be a low molecular weight compound or a higher molecular weight compound such as a resin.

As a low molecular weight compound having an aminotriazine ring, various additives having an aminotriazine ring can be used. Commercially available products include VT, VD-3, and VD-4 (all manufactured by Shikoku Kasei Co., Ltd.), which are compounds having an aminotriazine ring and a hydroxyl group, and VD-5 (all manufactured by Shikoku Kasei Co., Ltd.), which is a compound having an aminotriazine ring and an ethoxysilyl group. Gaisha), etc. These may be used individually or in combination of two or more types.

The amount of the low molecular weight compound having an aminotriazine ring to be used is preferably 0.1 to 50 parts by mass, more preferably 0.5 to 10 parts by mass, per 100 parts by mass of the resin component.

Resins having an aminotriazine ring include those in which the aminotriazine ring is introduced by a covalent bond into the polymer chain of the resin. Specifically, aminotriazine-modified novolak resin is preferable.

Aminotriazine-modified novolac resin is a novolak resin in which an aminotriazine ring structure and a phenol structure are bonded through a methylene group. Aminotriazine-modified novolak resins include, for example, aminotriazine compounds such as melamine, benzoguanamine, and acetoguanamine, and phenol compounds such as phenol, cresol, butylphenol, bisphenol A, phenylphenol, naphthol, and resorcin. and formaldehyde are cocondensed in the vicinity of neutrality in the presence of a weakly alkaline catalyst such as an alkylamine or without a catalyst, or an alkyl etherified product of an aminotriazine compound such as methyl etherified melamine is reacted with a phenol compound. You can get it by doing it.

It is preferable that the aminotriazine-modified novolac resin has substantially no methylol group. Additionally, the aminotriazine-modified novolak resin may contain molecules in which only the aminotriazine structure is methylene-bonded, molecules in which only the phenol structure is methylene-bonded, etc., which are generated as by-products during its production. Additionally, a small amount of unreacted raw materials may be contained.

Examples of the phenol structure include phenol residue, cresol residue, butylphenol residue, bisphenol A residue, phenylphenol residue, naphthol residue, and resorcin residue. Additionally, the residue here means a structure in which at least one hydrogen atom bonded to the carbon of the aromatic ring is missing. For example, in the case of phenol, it means a hydroxyphenyl group.

Examples of the triazine structure include structures derived from aminotriazine compounds such as melamine, benzoguanamine, and acetoguanamine.

The phenol structure and the triazine structure may be used individually or in combination of two or more types. Moreover, since adhesion can be further improved, a phenol residue is preferable as the phenol structure, and a structure derived from melamine is preferable as the triazine structure.

In addition, the hydroxyl value of the aminotriazine-modified novolak resin is preferably 50 to 200 mgKOH/g, and more preferably 80 to 180 mgKOH/g, since adhesion can be further improved.

Aminotriazine-modified novolak resins may be used individually, or two or more types may be used in combination. In addition, when using an epoxy resin and an aminotriazine-modified novolak resin in combination, from the viewpoint of improving adhesion, the molar ratio of the phenolic hydroxyl group (x) in the aminotriazine-modified novolac resin and the epoxy group (y) in the epoxy resin is (y/x) is preferably in the range of 0.1 to 5, and more preferably in the range of 0.2 to 3.

In addition to the above-described epoxy resin and the compound having an aminotriazine ring, the primer layer may further contain a crosslinking agent as needed. As a crosslinking agent, it is preferable to use polyhydric carboxylic acid. Examples of polyhydric carboxylic acids include trimellitic anhydride, pyromellitic anhydride, maleic anhydride, and succinic acid. These crosslinking agents may be used individually, or two or more types may be used in combination. Moreover, among these crosslinking agents, trimellitic anhydride is preferable because it can further improve adhesion.

Additionally, a curing catalyst may be used to promote the reaction between the epoxy group and various curing agents. Examples of the curing catalyst include tertiary amines, imidazole compounds, organic phosphines, and Lewis acid catalysts.

Tertiary amines include, for example, trimethylamine, triethylamine, tripropylamine, tributylamine, triamylamine, trihexylamine, trioctylamine, trilaurylamine, dimethylethylamine, dimethylpropylamine, and dimethylamine. Butylamine, dimethylamylamine, dimethylhexylamine, dimethylcyclohexylamine, dimethyloctylamine, dimethyllaurylamine, triallylamine, tetramethylethylenediamine, triethylenediamine (triethylenetetramine: TETA), N-methylmor Pauline, 4,4'-(oxydi-2,1-ethanediyl)bis-morpholine, N,N-dimethylbenzylamine, pyridine, picoline, dimethylaminomethylphenol, trisdimethylaminomethylphenol, triethanolamine, N,N'-dimethylpiperazine, tetramethylbutanediamine, bis(2,2-morpholinoethyl)ether, bis(dimethylaminoethyl)ether, N,N',N"-tris(dimethylaminopropyl)hexa Hydro-s-triazine, N,N',N"-tris(dimethylaminoethyl)hexahydro-s-triazine, N,N',N"-tris(2-hydroxyethyl)hexahydro-s- Triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 1,8-diazabicyclo[5.4.0]undecene-1 , 1,4-diazabicyclo[2.2.2]octane, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), etc.

Examples of imidazole compounds include 1-benzyl-2-imidazole (1B2MZ), 2-ethyl-4-imidazole, 2-underimidazole, 1,2-dimethylimidazole, and 1-benzyl-2. -phenylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole (2E4MZ), 2-phenyl-4-methyl-5-hydroxymethylimidazole (2P4MHZ), 2,3 -dihydro-1H-pyrrolo[1,2-a]benzimidazole (TBZ), etc. can be mentioned.

Examples of organic phosphine include triphenylphosphine (TPP), triphenylphosphine-triphenyl borate, tris(p-methoxyphenyl)phosphine, and tetraphenylphosphonium/tetraphenyl borate.

Examples of the Lewis acid catalyst include Lewis acid catalysts such as boronamine trifluoride complex, boronamine trichloride complex, and boronethylamine trifluoride complex.

Among these curing catalysts, it is preferable to use a tertiary amine and an imidazole compound, and it is more preferable to use an imidazole compound since the adhesion can be further improved. In addition, these curing catalysts can be used alone or in combination of two or more types. In addition, the suitable compounding amount of the curing catalyst is preferably 0.3 to 20 parts by mass, more preferably 0.5 to 15 parts by mass, based on 100 parts by mass of the total amount of all resins contained in the primer layer, in terms of solid content.

Additionally, the primer layer may, if necessary, contain other resins as components other than those mentioned above. Other resins include, for example, urethane resin, acrylic resin, imide resin, amide resin, melamine resin, phenol resin, urea-formaldehyde resin, blocked polyisocyanate using phenol as a blocking agent, polyvinyl alcohol, and polyvinylpyrrolidone. etc. can be mentioned. These binder resins may be used individually, or two or more types may be used together.

In addition, when forming the primer layer, it is preferable to mix an organic solvent in addition to the above components in order to provide a viscosity that is easy to apply when coating on a support. Examples of organic solvents include toluene, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and isopropyl alcohol.

The amount of the organic solvent used can be appropriately adjusted depending on the coating method used when coating the support and the desired thickness of the primer layer.

Additionally, known additives such as film forming aids, leveling agents, thickeners, water repellent agents, anti-foaming agents, and antioxidants may be added to the coating solution for forming the primer layer as needed.

The primer layer can be formed by applying a coating solution containing the above-described components to part or all of the surface of the support and removing the organic solvent contained in the coating solution by heating or drying it.

The coating method is not particularly limited, and conventionally known coating methods can be applied, for example, gravure method, coating method, screen method, roller method, rotary method, spray method, capillary method, etc. .

After applying the coating liquid to the surface of the support, a common method of removing the organic solvent contained in the coating film is, for example, drying using a dryer and volatilizing the organic solvent. The drying temperature may be set to a temperature within a range that allows volatilization of the organic solvent used and does not adversely affect the support, such as thermal deformation.

The thickness of the primer layer may be adjusted appropriately depending on the intended use of the laminate of the present invention, but is preferably in a range that further improves the adhesion between the support and the metal particle layer described later, and the thickness of the primer layer is preferably 10 nm to 1 μm. And, it is more preferable that it is 10 nm to 500 nm. The thickness of the primer layer can be adjusted by the amount of coating liquid applied to the support.

From the viewpoint of adhesion to the metal particle layer, which will be described later, the surface of the primer layer can be treated, if necessary, by plasma discharge treatment such as corona discharge treatment, dry treatment such as ultraviolet treatment, or wet treatment using water, an acidic or alkaline chemical solution, organic solvent, etc. Surface treatment may be performed.

<Metal particle layer>

The metal particle layer is provided on the above-mentioned primer layer and is a layer provided to form the metal plating layer described later. The metal particle layer is preferably a layer containing a composite of metal particles and an organic compound. In the present invention, it is more preferable that the metal particle layer contains a compound having metal particles and a cationic group.

Metals constituting the metal particles include transition metals or their compounds, and among these, ionic transition metals are preferable. Ionic transition metals include copper, silver, gold, nickel, palladium, platinum, and cobalt, and silver is preferable from the viewpoint of formability of a metal plating layer, which will be described later. In addition, in the present invention, metal particles shall refer to particulate or fibrous particles containing the above-mentioned metal.

When using particulate metal, the average particle diameter is preferably 1 to 100 nm, and more preferably 1 to 50 nm, from the viewpoint of further reducing the resistance value. In addition, in this specification, the average particle diameter means the volume average value (D50) measured by diluting metal particles with a good dispersion solvent and measuring them by a dynamic light scattering method. Also, when using fibrous metal, the fiber diameter is preferably 5 to 100 nm, and more preferably 5 to 50 nm, from the viewpoint of further reducing the resistance value. Additionally, the fiber length is preferably 0.1 to 100 μm, and more preferably 0.1 to 30 μm.

As an organic compound used in combination with metal particles, a compound having a cationic group can be preferably used. The compound having a cationic group not only disperses the above-described metal particles well, but also reacts with the functional group contained in the constituents of the primer layer, for example, the epoxy group contained in the epoxy resin, and forms a layer at the interface between the primer layer and the metal particle layer. It is desirable because it has the function of further improving adhesion. Additionally, the compound having a cationic group may be surface-treated on the metal particles included in the metal particle layer.

As the compound having a cationic group, a compound having a basic nitrogen atom-containing group can be preferably used, for example, polyalkylene imine such as polyethylene imine and polypropylene imine, and a compound in which polyoxyalkylene is added to polyalkylene imine. etc. can be used. A compound in which polyoxyalkylene is added to polyalkylene imine is preferable because it can improve the water dispersion stability of metal particles.

As polyoxyalkylene, for example, random or block structures such as polyoxyethylene and poly(oxyethylene-oxypropylene) can be used. As polyoxyalkylene, it is preferable to use a polyoxyalkylene having an oxyethylene unit from the viewpoint of water dispersion stability of the metal particles, and a polyoxyalkylene having an oxyethylene unit in the range of 10 to 90% by mass based on the total polyoxyalkylene. It is desirable to use

As a compound obtained by adding polyoxyalkylene to polyalkyleneimine, for example, those having a structure containing polyethyleneimine and a polyoxyalkylene structure such as a polyethylene oxide structure can be used.

Polyethyleneimine and polyoxyalkylene may be bonded in a straight chain, or may be bonded by grafting polyoxyalkylene to the side chain of the main chain containing polyethyleneimine.

As a compound in which polyoxyalkylene is added to polyalkyleneimine, specifically, a copolymer of polyethyleneimine and polyoxyethylene, a compound obtained by addition reaction of a part of the imino group present in the main chain and ethylene oxide, etc. can be used. You can. They preferably have a block structure.

As a compound obtained by adding polyoxyalkylene to polyalkyleneimine, one obtained by reacting the amino group of polyalkyleneimine, the hydroxyl group of polyoxyethylene glycol, and the epoxy group of epoxy resin can also be used.

As the polyalkylene imine, a commercial product may be used, for example, Eformin (registered trademark), SP-003, SP-006, SP-012, SP-018, SP-200, P-1000 ( Above, you can use Kabushikigaisha Nippon Shokubai.

The metal particle layer may contain an epoxy resin in addition to the metal particles described above. As the epoxy resin, one similar to that described for the above primer layer can be used. However, when using a compound having a basic nitrogen atom-containing group as the compound having a cationic group, the epoxy resin reacts with the compound having a basic nitrogen atom-containing group. From the viewpoint of suppressing waste, aliphatic epoxy resins can be preferably used, and among them, alicyclic epoxy resins can be used more preferably.

Examples of aliphatic epoxy resins include neopentyl glycol diglycidyl ether, dimethylol cyclohexane diglycidyl ether, 1,4-cyclohexane diglycidyl ether, and 1,3-cyclohexane diglycidyl ether. , 1,2-cyclohexane diglycidyl ether, dimethylol dicyclopentadiene diglycidyl ether, hexahydrophthalic acid diglycidyl ester, hexahydroterephthalic acid diglycidyl ester, 1,4-butanediol diglycidyl. Acyclic aliphatic epoxy resins such as ether and 1,6-hexanediol diglycidyl ether, 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, and ε-caprolactone modified 3. Alicyclic epoxy resins such as ',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, limonenedioxide, dicyclopentadienedioxide, and hydrogenated bisphenol A type diglycidyl ether are included. there is. These aliphatic epoxy resins may be used individually or in combination of two or more types.

In the present invention, from the viewpoint of inhibition of reaction with a compound having a basic nitrogen atom-containing group in the coating solution for forming a metal particle layer and compatibility with solvents described later, alicyclic epoxy resins are preferred, especially 3', 4'-Epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate and ε-caprolactone modified 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate can be preferably used. .

As the above-mentioned epoxy resin, commercially available ones may be used, for example, ADEKA RESIN EP-4080S, EP-4085S, EP-4088S (above, manufactured by ADEKA Corporation), Celoxide 2021P, Celoxide 2081, Celoxide. 2083, Celoxide 2085, Celoxide 8010, EHPE 3150, EPOLEAD PB 3600, EPOLEAD PB 4700 (above, manufactured by Daicel Corporation), Denacol EX-121, EX-211, EX-212, EX-212L. , EX-214, EX-214L, EX-216, EX-216L, EX-252, EX-252L, EX-321, EX-321L, EX-830, EX-830L. , EX-850, EX-850L (manufactured by Nagase Chemtex Co., Ltd.), Showfree CDMDG, PETG (manufactured by Showa Denko Co., Ltd.), etc.

The metal particle layer can be formed by dissolving or dispersing the above components in a suitable solvent to prepare a coating solution, applying it on a primer layer to form a coating film, and drying the coating film to remove the solvent.

As a solvent used in the coating solution for forming a metal particle layer, for example, in addition to aqueous media such as distilled water, ion-exchanged water, pure water, and ultrapure water, organic solvents such as alcohol, ether, ester, and ketone can be used.

Examples of alcohol include methanol, ethanol, n-propanol, isopropyl alcohol, n-butanol, isobutyl alcohol, sec-butanol, tert-butanol, heptanol, hexanol, octanol, nonanol, decanol, and undecorate. Canol, dodecanol, tridecanol, tetradecanol, pentadecanol, stearyl alcohol, allyl alcohol, cyclohexanol, terpineol, terpineol, dihydroterpineol, ethylene glycol monomethyl ether, ethylene glycol Monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether , tripropylene glycol monomethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, etc. can be used.

For the coating solution, a combination of ketone solvents such as acetone, cyclohexanone, and methyl ethyl ketone can be used to adjust the physical properties. In addition, ester solvents such as ethyl acetate, butyl acetate, 3-methoxybutyl acetate, and 3-methoxy-3-methyl-butyl acetate, hydrocarbon solvents such as toluene, and especially hydrocarbon solvents with 8 or more carbon atoms can be used.

Hydrocarbon solvents with a carbon number of 8 or more include, for example, octane, nonane, decane, dodecane, tridecane, tetradecane, cyclooctane, xylene, mesitylene, ethylbenzene, dodecylbenzene, tetralin, trimethylbenzenecyclohexane, etc. Non-polar solvents may be used in combination as needed. Additionally, mixed solvents such as mineral spirits and solvent naphtha may be used together.

Other solvents include, for example, 2-ethyl 1,3-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, 1,2-butanediol, 1,4-butanediol, 2,3-butanediol, glycerin, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol mono Butyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, etc. can be used.

The coating liquid for forming a metal particle layer may contain a surfactant, an antifoaming agent, a rheology modifier, etc. as needed from the viewpoint of improving wettability, etc. when applying to the primer layer.

The content of metal particles contained in the coating solution for forming a metal particle layer is preferably 1 to 90% by mass, more preferably 5 to 60% by mass, and even more preferably 10 to 40% by mass, based on the entire coating solution. do. Moreover, the content of the compound having a cationic group is preferably 0.01 to 10% by mass, and more preferably 0.05 to 5% by mass, based on the entire coating liquid. In addition, when the coating solution is applied and dried to form a metal particle layer (i.e., when the solvent is removed), the epoxy resin is preferably contained in an amount of 0.01 to 10% by mass, and is preferably 0.05 to 5% by mass in the metal particle layer. It is more desirable to have

The metal particle layer may be a layer provided on the entire surface of the primer layer, or may be a layer provided on a part of the surface of the primer layer. Examples of forming a metal particle layer on a part of the surface of the primer layer include, specifically, a thin line-like layer formed by strokes on the surface of the primer layer. The fine wire-like layer is suitable when the laminate according to the present invention is used for a printed wiring board or the like. In this case, the width (line width) of the thin line layer (pattern) is approximately 0.01 to 200 μm, preferably approximately 0.01 to 150 μm.

The metal particle layer preferably has a thickness of 0.01 to 100 μm in order to form a conductive pattern with low resistance and excellent conductivity. Additionally, when the metal particle layer is in the form of fine wires, its thickness (height) is preferably in the range of 0.05 to 50 μm. The thickness of the metal particle layer can be adjusted by the amount of coating liquid applied to the primer layer.

Methods for applying the coating liquid for forming a metal particle layer to the primer layer include, for example, reverse printing methods such as relief plate reverse printing, inkjet printing, screen printing, offset printing, gravure printing, and spin coating. Examples include spray coating, bar coating, die coating, slit coating, roll coating, and dip coating. In addition, when applying (printing) in a thin line shape of approximately 0.01 to 100 μm, which is required when realizing increased density of electronic circuits, etc., it is preferable to adopt the inkjet printing method.

<Metal plating layer>

The metal plating layer constituting the laminate of the present invention provides a highly reliable wiring pattern that can maintain good conductivity without causing disconnection over a long period of time, for example, when the laminate is used for a printed wiring board or electromagnetic wave shield. It is a layer prepared for the purpose of forming a layer.

The metal plating layer is a layer formed on the above-mentioned metal particle layer, but a method of forming it by plating is preferable. Examples of this plating treatment include wet plating methods such as electrolytic plating and electroless plating that can easily form a metal plating layer. Additionally, two or more of these plating methods may be combined. For example, after electroless plating, electrolytic plating may be performed to form a metal plating layer.

The electroless plating method is a method of forming an electroless plating layer including a metal film by, for example, contacting the metal constituting the metal particle layer with an electroless plating solution to precipitate metals such as copper contained in the electroless plating solution. Examples of electroless plating solutions include those containing metals such as copper, silver, gold, nickel, chromium, cobalt, and tin, a reducing agent, and solvents such as an aqueous medium and an organic solvent.

Examples of the reducing agent include dimethylaminoborane, hypophosphorous acid, sodium hypophosphite, dimethylamineborane, hydrazine, formaldehyde, sodium borohydride, and phenol.

As the electroless plating solution, if necessary, monocarboxylic acids such as acetic acid and formic acid; Dicarboxylic acid compounds such as malonic acid, succinic acid, adipic acid, maleic acid, and fumaric acid; Hydroxycarboxylic acid compounds such as malic acid, lactic acid, glycolic acid, gluconic acid, and citric acid; Amino acid compounds such as glycine, alanine, iminodiacetic acid, arginine, aspartic acid, and glutamic acid; Organic acids such as aminopolycarboxylic acid compounds such as iminodiacetic acid, nitrilotriacetic acid, ethylenediaminediacetic acid, ethylenediaminetetraacetic acid, and diethylenetriaminepentaacetic acid, or soluble salts of these organic acids (sodium salt, potassium salt, ammonium salt) etc.), those containing complexing agents such as amine compounds such as ethylenediamine, diethylenetriamine, and triethylenetetramine can be used.

The electrolytic plating method, for example, applies electricity to the surface of the metal constituting the metal particle layer or the electroless plating layer (film) formed by electroless treatment while the electrolytic plating solution is in contact, thereby plating metals such as copper contained in the electrolytic plating solution. This is a method of forming an electrolytic plating layer by depositing it on the surface of the metal particles constituting the metal particle layer provided on the cathode or the electroless plating layer formed by electroless treatment.

Examples of electrolytic plating solutions include those containing sulfides of metals such as copper, nickel, chromium, cobalt, and tin, sulfuric acid, and an aqueous medium. Specifically, those containing copper sulfate, sulfuric acid, and an aqueous medium can be mentioned.

As a method of forming a metal plating layer, a method of performing electroless plating followed by electrolytic plating is preferable because it is easy to control the film thickness of the metal plating layer to a desired film thickness from a thin film to a thick film.

The film thickness of the metal plating layer is preferably 1 to 50 μm. The film thickness of the metal plating layer can be adjusted by controlling the processing time, current density, amount of plating additive used, etc. in the plating process when forming the metal plating layer.

<Use of laminate>

In the laminate according to the present invention, not only does the metal plating layer formed on the surface not peel off under certain conditions, but the adhesion of the metal plating layer is maintained even when placed at a high temperature of 150°C for a long time. Therefore, the formation of circuit formation substrates used in electronic circuits, integrated circuits, etc., the formation of peripheral wiring constituting organic solar cells, electronic book terminals, organic EL, organic transistors, flexible printed circuit boards, RFID, etc., and the electromagnetic waves of plasma displays. It can be used especially for applications requiring durability, such as shield wiring. In particular, the conductive pattern to which the above-described plating treatment has been applied can form a highly reliable wiring pattern that can maintain good current conductivity without causing disconnection or the like over a long period of time, and is therefore used in, for example, flexible printed circuit boards (FPC) or electromagnetic wave shields. It is possible to use it for electronic devices such as:

As an embodiment of the present invention, a laminate having a primer layer, a metal particle layer, and a metal plating layer sequentially provided on one side of the support has been described as an example. However, as another embodiment of the present invention, a primer layer is also provided on the opposite side of the support, It may be a laminate provided sequentially with a metal particle layer and a metal plating layer.

Example

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the examples. In addition, in the following, “part” and “%” are all based on mass unless otherwise specified.

<Preparation of phenoxy resin>

As follows, three types of phenoxy resins (P-1) to (P-3) were synthesized.

[Synthesis Example 1: Phenoxy Resin (P-1)]

In a reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing pipe, and cooling pipe, 100 parts by mass of bisphenol A type epoxy resin (Epiclon EXA-850CRP manufactured by DIC Corporation, solid content 100% by mass, epoxy equivalent weight 173 g/eq), 65 parts by mass of bisphenol A (ratio of the number of moles of the epoxy group (E1) to the number of moles of the phenolic hydroxyl group (F1) (E1/F1) = 1.01) and 15 parts of cyclohexanone as a reaction solvent were added, and the mixture was heated at 100°C under a nitrogen atmosphere. The temperature was raised to Next, after adding 0.1 part of methyltriphenylphosphonium bromide as a catalyst, the internal temperature was raised to 140°C. As the reaction progressed, the reaction solution began to thicken, so 72 parts of cyclohexanone was added in several portions as appropriate, and the reaction was carried out while keeping the torque of the stirrer constant. In addition, the reaction temperature was 140 to 145°C when the non-volatile content was 80% or more, and thereafter, the reaction was performed at reflux temperature. Samples were collected during the reaction, and the average molecular weight was measured by GPC. The reaction was continued until the weight average molecular weight reached 20,000. After confirming that the molecular weight was above, the reaction was terminated. Next, cyclohexanone was added and stirred to obtain a phenoxy resin (P-1) with a solid content of 15% by mass.

[Synthesis Example 2: Phenoxy Resin (P-2)]

In a reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing pipe, and cooling pipe, 100 parts by mass of bisphenol A type epoxy resin (Epiclon EXA-850CRP manufactured by DIC Corporation, solid content 100% by mass, epoxy equivalent weight 173 g/eq), 65 parts by mass of bisphenol A (ratio of the number of moles of the epoxy group (E1) to the number of moles of the phenolic hydroxyl group (F1) (E1/F1) = 1.01) and 15 parts of cyclohexanone as a reaction solvent were added, and the mixture was heated at 100°C under a nitrogen atmosphere. The temperature was raised to Next, after adding 0.1 part of methyltriphenylphosphonium bromide as a catalyst, the internal temperature was raised to 140°C. As the reaction progressed, the reaction solution began to thicken, so 72 parts of cyclohexanone was added in several portions as appropriate, and the reaction was carried out while keeping the torque of the stirrer constant. In addition, the reaction temperature was 140 to 145°C when the non-volatile content was 80% or more, and thereafter, the reaction was performed at reflux temperature. Samples were collected during the reaction, and the average molecular weight was measured by GPC. The reaction was continued until the weight average molecular weight reached 45,000. After confirming that the molecular weight was the above, the reaction was terminated. Next, cyclohexanone was added and stirred to obtain a phenoxy resin (P-2) with a solid content of 15% by mass.

[Synthesis Example 3: Phenoxy Resin (P-3)]

In a reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing pipe, and cooling pipe, 100 parts by mass of bisphenol A type epoxy resin (Epiclon EXA-850CRP manufactured by DIC Corporation, solid content 100% by mass, epoxy equivalent weight 173 g/eq), 65 parts by mass of bisphenol A (ratio of the number of moles of the epoxy group (E1) to the number of moles of the phenolic hydroxyl group (F1) (E1/F1) = 1.01) and 15 parts of cyclohexanone as a reaction solvent were added, and the mixture was heated at 100°C under a nitrogen atmosphere. The temperature was raised to Next, after adding 0.1 part of methyltriphenylphosphonium bromide as a catalyst, the internal temperature was raised to 140°C. As the reaction progressed, the reaction solution began to thicken, so 72 parts of cyclohexanone was added in several portions as appropriate, and the reaction was carried out while keeping the torque of the stirrer constant. In addition, the reaction temperature was 140 to 145°C when the non-volatile content was 80% or more, and thereafter, the reaction was performed at reflux temperature. Samples were collected during the reaction, and the average molecular weight was measured by GPC. The reaction was continued until the weight average molecular weight reached 100,000. After confirming that the molecular weight was above, the reaction was terminated. Next, cyclohexanone was added and stirred to obtain a phenoxy resin (P-3) with a solid content of 15% by mass.

[Synthesis Example 4: Modified Novolak Resin C]

Add 750 parts by mass of phenol, 75 parts by mass of melamine, 346 parts by mass of 41.5% formalin, and 1.5 parts by mass of triethylamine to a flask equipped with a thermometer, cooling tube, flow distribution tube, and stirrer, and raise the temperature to 100°C, paying attention to heat generation. I ordered it. After reacting at 100°C under reflux for 2 hours, the temperature was raised to 180°C over 2 hours while removing water under normal pressure. Next, unreacted phenol was removed under reduced pressure to obtain an aminotriazine-modified novolak resin as novolak resin C. The hydroxyl equivalent weight was 120 g/equivalent.

<Preparation of coating solution for forming primer layer>

[Preparation Example 1: Preparation of coating solution (1) for forming primer layer]

The phenoxy resin (P-1) obtained in Synthesis Example 1 was diluted with cyclohexanone so that the non-volatile content was 2% by mass, and mixed uniformly to obtain a coating liquid for forming a primer layer (1).

[Preparation Example 2: Preparation of coating solution (2) for forming primer layer]

The phenoxy resin (P-2) obtained in Synthesis Example 2 was diluted with cyclohexanone so that the non-volatile content was 2% by mass, and mixed uniformly to obtain a coating liquid for forming a primer layer (2).

[Preparation Example 3: Preparation of coating solution (3) for forming primer layer]

The phenoxy resin (P-3) obtained in Synthesis Example 3 was diluted with cyclohexanone so that the non-volatile content was 2% by mass, and mixed uniformly to obtain a coating liquid for forming a primer layer (3).

[Preparation Example 4: Preparation of coating solution (4) for forming primer layer]

533 parts by mass of the phenoxy resin (P-1) obtained in Synthesis Example 1, 17 parts by mass of epoxy resin A (“EPICLON 850-S” manufactured by DIC Corporation; bisphenol A type epoxy resin, epoxy group equivalent 188 g/equivalent), 3 parts by mass of novolac resin B (“PHENOLITE TD-2131” manufactured by DIC Corporation, hydroxyl equivalent 104 g/equivalent) and 0.5 parts by mass of “TBZ” manufactured by Shikoku Kasei Corporation as curing catalyst 1 were mixed, and cyclohexanone was added. was diluted so that the non-volatile content was 2% by mass, and mixed uniformly to obtain a coating liquid (4) for forming a primer layer.

[Preparation Example 5: Preparation of coating solution (5) for forming primer layer]

267 parts by mass of the phenoxy resin (P-2) obtained in Synthesis Example 2, 60 parts by mass of epoxy resin A (“EPICLON 850-S” manufactured by DIC Corporation; bisphenol A type epoxy resin, epoxy group equivalent 188 g/equivalent), and 0.5 parts by mass of "TBZ" manufactured by Shikoku Kasei Co., Ltd. as the curing catalyst 1, diluted with cyclohexanone so that the non-volatile content is 2% by mass, and mixed uniformly to obtain a coating solution for forming a primer layer (5 ) was obtained.

[Preparation Example 6: Preparation of coating solution (6) for forming primer layer]

133 parts by mass of the phenoxy resin (P-2) obtained in Synthesis Example 1, 70 parts by mass of epoxy resin A (“EPICLON 850-S” manufactured by DIC Corporation; bisphenol A type epoxy resin, epoxy group equivalent 188 g/equivalent), 10 parts by mass of the modified novolak resin C obtained in Synthesis Example 4 and 5 parts by mass of "2E4MZ" manufactured by Shikoku Chemicals Co., Ltd. as the curing catalyst 2 were mixed, and diluted using cyclohexanone so that the nonvolatile content was 2% by mass. , and uniformly mixed to obtain a coating liquid (6) for forming a primer layer.

[Preparation Example 7: Preparation of coating solution (7) for forming primer layer]

67 parts by mass of the phenoxy resin (P-3) obtained in Synthesis Example 3, 76 parts by mass of epoxy resin A (“EPICLON 850-S” manufactured by DIC Corporation; bisphenol A type epoxy resin, epoxy group equivalent 188 g/equivalent), 14 parts by mass of novolac resin B (“PHENOLITE TD-2131” manufactured by DIC Corporation, hydroxyl equivalent 104 g/equivalent) and 0.5 parts by mass of “TBZ” manufactured by Shikoku Kasei Corporation as curing catalyst 1 were mixed, and cyclohexanone was added. was diluted so that the non-volatile matter was 2% by mass, and mixed uniformly to obtain a coating liquid for forming a primer layer (7).

[Preparation Example 8: Preparation of coating solution (8) for forming primer layer]

After mixing 35 parts by mass of epoxy resin A (“EPICLON 850-S” manufactured by DIC Corporation; bisphenol A type epoxy resin, epoxy group equivalent 188 g/equivalent) with 65 parts by mass of modified novolak resin C obtained in Synthesis Example 4, methyl It was diluted with ethyl ketone to a non-volatile content of 2% by mass and mixed uniformly to obtain a mixed resin solution of aminotriazine-modified novolac resin and epoxy resin.

<Preparation of coating solution for forming metal particle layer>

Under a nitrogen atmosphere, a solution of chloroform (30 ml) containing 9.6 parts by mass of p-toluenesulfonic acid chloride was added to a mixture containing 20 parts by mass of methoxypolyethylene glycol (number average molecular weight 2,000), 8.0 parts by mass of pyridine, and 20 ml of chloroform, while cooling on ice and stirring. After adding dropwise for 30 minutes, the mixture was stirred at a bath temperature of 40°C for 4 hours, and 50 ml of chloroform was mixed.

Next, the obtained product was washed with 100 ml of a 5 mass% aqueous hydrochloric acid solution, then washed with 100 ml of a saturated aqueous sodium bicarbonate solution, then washed with 100 ml of a saturated saline solution, dried using anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure. After washing with hexane several times, it was filtered and dried under reduced pressure at 80°C to obtain methoxypolyethylene glycol having a p-toluenesulfonyloxy group.

5.39 parts by mass of methoxypolyethylene glycol having a p-toluenesulfonyloxy group, 20 parts by mass of polyethyleneimine (manufactured by Aldrich, molecular weight 25,000), 0.07 parts by mass of potassium carbonate, and 100 ml of N,N-dimethylacetamide were mixed under a nitrogen atmosphere. It was stirred at 100°C for 6 hours.

Next, 300 ml of a mixed solution of ethyl acetate and hexane (volume ratio of ethyl acetate/hexane = 1/2) was added, and after vigorous stirring at room temperature, the solid product was filtered. The solid was washed with 100 ml of a mixed solution of ethyl acetate and hexane (volume ratio of ethyl acetate/hexane = 1/2) and then dried under reduced pressure to obtain a compound in which polyethylene glycol is bonded to polyethyleneimine.

138.8 parts by mass of an aqueous solution containing 0.592 parts by mass of the obtained polyethyleneimine and polyethylene glycol bonded compound and 10 parts by mass of silver oxide were mixed and stirred at 25°C for 30 minutes. Next, 46 parts by mass of dimethylethanolamine was gradually added while stirring, and stirred at 25°C for 30 minutes. Subsequently, 15.2 parts by mass of a 10% by mass ascorbic acid aqueous solution was gradually added while stirring, and stirring was continued for 20 hours to obtain a silver dispersion.

A mixed solvent of 200 ml of isopropyl alcohol and 200 ml of hexane was added to the obtained silver dispersion, stirred for 2 minutes, and then concentrated by centrifugation at 3000 rpm for 5 minutes. After removing the supernatant, a mixed solvent of 50 ml of isopropyl alcohol and 50 ml of hexane was added to the precipitate, stirred for 2 minutes, and then concentrated by centrifugation at 3000 rpm for 5 minutes. After removing the supernatant, 20 parts by mass of water was added to the precipitate, stirred for 2 minutes, and the organic solvent was removed under reduced pressure. After further adding 10 parts by mass of water and stirring and dispersing, the dispersion was frozen by leaving it in a freezer at -40°C for 1 week, and then treated with a freeze dryer (FDU-2200, manufactured by Tokyo Rika Kikai Co., Ltd.) for 24 hours. By doing so, cationic silver particles containing flake-like masses with a gray-green metallic luster were obtained.

The obtained powder of cationic silver particles was dispersed in a mixed solvent of 45 parts by mass of ethylene glycol and 55 parts by mass of ion-exchanged water, and a coating liquid for forming a metal particle layer having a content of cationic silver particles of 5% by mass was prepared.

<Production of laminates (1) to (8)>

Each primer layer forming coating solution (1) to (8) obtained above was applied to the surface of a polyimide film (“Kapton 150EN-A” manufactured by Toray DuPont Co., Ltd.; thickness 38 μm) using a tabletop small coater (K). Using Printing Propa, RK Print Coat Instrument Co., Ltd., it was applied so that the thickness of the coating film after drying was 300 nm. Next, a primer layer was formed on the surface of the polyimide film by drying at 155°C for 5 minutes using a hot air dryer.

Subsequently, the coating liquid for forming a metal particle layer obtained above was applied to the surface of the primer layer using a bar coater so that the film thickness after drying was 100 nm. Next, the metal particle layer was formed by drying at 140°C for 5 minutes.

The metal particle layer formed as described above is set to the cathode side, phosphorus-containing copper is set to the anode side, and electrolytic plating is performed for 18 minutes at a current density of 2 A/dm ² using an electrolytic plating solution containing copper sulfate, thereby forming a layer on the metal particle layer. A copper plating layer (8 μm thickness) was formed. As the electrolytic plating solution, 70 g/L of copper sulfate, 200 g/L of sulfuric acid, 50 mg/L of chlorine ion, and 5 ml/L of additive (Toprutina SF-M, Okuno Seiyaku Kogyo Co., Ltd.) were used.

In this way, laminates (1) to (8) in which the support, primer layer, metal particle layer, and metal plating layer were sequentially laminated were obtained. In addition, the number of the coating solution for forming a primer layer corresponds to the number of the laminate. For example, the coating solution for forming a primer layer (1) corresponds to the laminate (1).

<Adhesion evaluation (in condition)>

For each laminate obtained above, the peel strength was measured using 4000Plus manufactured by Nordson DAGE in a room temperature environment. Additionally, the lead width used for measurement was 5 mm, and the peel angle was 90°. In addition, the peel strength tends to show a higher value as the thickness of the metal plating layer becomes thicker, but in this specification, the peel strength was measured based on the measured value at a thickness of 8 μm of the metal plating layer.

From the measured peel strength before heating, adhesion was evaluated according to the following criteria.

A: The peel strength value is 600 N/m or more.

B: The peel strength value is 450 N/m or more and less than 600 N/m.

C: The peel strength value is 250 N/m or more and less than 450 N/m.

D: The peel strength value is less than 250 N/m.

The evaluation results were as shown in Table 1 below.

<Adhesion evaluation (long-term heat resistance test)>

Each laminate obtained above was stored and heated in a dryer set at 150°C for 300 hours. After heating, each laminate was cooled to room temperature, and the peeling strength was measured in the same manner as above.

Using the measured peeling strength values before and after heating, the retention rate before and after heating was calculated, and the degree of heat resistance retention was evaluated according to the following criteria.

A: The retention rate is over 80%.

B: The retention rate is 60% or more and less than 80%.

C: The retention rate is 30% or more and less than 60%.

D: The retention rate is less than 30%.

The evaluation results were as shown in Table 1 below.

As is clear from the adhesion evaluation results shown in Table 1, the laminates (laminated bodies (1) to (7)) using a phenoxy resin having a specific molecular weight as the primer layer all have a peeling strength of 450N/ m or more, and has a retention rate of 80% or more of the peeling strength as-is even after a long-term heat resistance test. In other words, it can be seen that all adhesion evaluations after the state trial and long-term heat resistance test are excellent.

In contrast, in the laminate (laminated body 8) that does not use a phenoxy resin as a primer layer, the peeling strength in the as-is state is high, but the retention rate is only 8% after the long-term heat resistance test, and stable adhesion is not achieved. don't have That is, compared to the examples, it can be seen that the adhesion evaluation after the long-term heat resistance test is poor.

Claims (11)

A laminate comprising a support and a primer layer, a metal particle layer, and a metal plating layer sequentially on the support, wherein the primer layer contains a phenoxy resin having a weight average molecular weight of 10,000 to 100,000. According to paragraph 1,
A laminate wherein the primer layer further includes an epoxy resin. According to paragraph 2,
A laminate wherein the primer layer contains the phenoxy resin and the epoxy resin in a ratio of 90:10 to 10:90 on a mass basis. According to paragraph 1,
A laminate in which the primer layer further contains a compound having an aminotriazine ring. According to clause 4,
A laminate wherein the compound having the aminotriazine ring is an aminotriazine-modified novolak resin. According to paragraph 1,
A laminate in which the metal particle layer contains metal particles and a compound having a cationic group. According to clause 6,
A laminate wherein the compound having the cationic group is a compound having a basic nitrogen atom-containing group. According to paragraph 1,
A laminate wherein the support is made of a flexible resin material. According to any one of claims 1 to 8,
Laminate used in electronic devices. According to clause 9,
A laminate in which the electronic device is selected from printed wiring boards and electromagnetic wave shields. An electronic device provided with the laminate according to any one of claims 1 to 8.