Easy-adhesion film and laminate

Abstract

To provide an easy-adhesion film having excellent adhesion between a film base material composed of a semi-aromatic polyamide resin and a metal layer formed by sputtering or electroless plating, and further excellent properties in terms of plating solution resistance, thermal resistance, blocking resistance, and bending resistance.SOLUTION: An easy-adhesion film has, on a film base material composed of a semi-aromatic polyamide resin, a primer layer that includes an acid-modified polyolefin resin and a crosslinking agent, where the acid-modified polyolefin resin contains an ethylene component as a polyolefin component, and the crosslinking agent is a compound having an epoxy group or an isocyanate group.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an easily adhesive film and a laminate. [Background technology]

[0002] Flexible printed circuit boards (FPCs) are an example of wiring boards used in electronic devices. In recent years, as electronic devices have become thinner and lighter, the demand for durability, such as flexibility, has increased for the base films used in these flexible boards. To address this demand, semi-aromatic polyamide resin films, which are excellent in heat resistance, flexibility, and the like, have been proposed (Patent Document 1).

[0003] Flexible printed circuit boards are produced by using a metal-clad laminate such as a copper-clad laminate (CCL), which is made by laminating copper onto an insulating base film, forming copper wiring by, for example, etching the copper, and then laminating a coverlay film to protect the copper wiring. One method for producing a copper-clad laminate is to laminate copper to a resin film with an adhesive layer, followed by thermocompression bonding. The copper foil used here is typically 18 μm or 35 μm thick, but this is not sufficient to accommodate the fine circuit formation that is required due to the increasing density of various devices in recent years.

[0004] Therefore, attempts have been made to produce copper-clad laminates by applying sputtering or electroless plating to a resin film to form a conductor layer made of metal, and then performing additional copper electroplating as necessary (e.g., Patent Documents 2 and 3). However, these methods of laminating a metal layer directly onto a resin film have the problem that the adhesion between the resin film and the metal is insufficient, and the metal is prone to peeling from the resin film during the electroplating process or reflow soldering process. Furthermore, the heat resistance is also insufficient.

[0005] Furthermore, in order to improve the adhesion between the semi-aromatic polyamide film and various materials, it has been proposed to use an easy-adhesion layer made of polyurethane resin on the surface of the semi-aromatic polyamide film, as in Patent Document 4, for example. However, although the easy-adhesion layer described in Patent Document 4 has excellent adhesion to a semi-aromatic polyamide resin film, it has problems in that it has insufficient adhesion performance to a metal layer formed by sputtering or electroless plating and has poor resistance to plating solutions.

[0006] Also, a method has been proposed in which a resin layer containing an acid-modified polyolefin resin is formed on a substrate and then bonded to a metal foil or the like to form a laminate (Patent Documents 5 and 6). Patent Documents 5 and 6 do not evaluate laminates using semi-aromatic polyamide films as substrates, and also have problems such as blocking when wound into a roll due to the thick adhesive layer. Furthermore, although they describe laminates consisting of a resin film and a metal foil or a resin film and a vapor deposition layer using an acid-modified polyolefin resin, they do not evaluate the adhesion between the semi-aromatic polyamide film and the metal foil or vapor deposition layer. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2023-36604 [Patent Document 2] Japanese Patent Publication No. 2020-012156 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-212143 [Patent Document 4] Patent Publication No. 2021-47295 [Patent Document 5] Patent No. 7215091 [Patent Document 6] Patent No. 5427516 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made to solve the above-mentioned problems, and aims to provide an easily adhesive film that exhibits excellent adhesion between a film substrate made of a semi-aromatic polyamide resin and a metal layer formed by sputtering or electroless plating, and that also exhibits excellent plating solution resistance, heat resistance, blocking resistance, and flex resistance. [Means for solving the problem]

[0009] As a result of extensive research to solve the above problems, the present inventors have found that the above object can be achieved, and have arrived at the present invention. That is, the gist of the present invention is as follows. (1) An easily adhesive film having a film substrate made of a semi-aromatic polyamide resin and a primer layer containing an acid-modified polyolefin resin and a crosslinking agent, wherein the acid-modified polyolefin resin contains an ethylene component as a polyolefin component, and the crosslinking agent is a compound containing an epoxy group or an isocyanate group. (2) A highly adhesive film of (1) that satisfies the following conditions when a 0.1 μm thick copper layer is formed on the primer layer by sputtering or electroless plating and the following peel resistance test is performed. [Peeling resistance test] Cross-cut test conforming to JIS K5600-5-6. [conditions] The peeling state of the copper layer is either Class 0, Class 1, or Class 2. (3) The easily adhesive film of (1) or (2), which contains organic and / or inorganic fine particles in the primer layer. (4) A laminate having a metal layer on the primer layer of the adhesive film of any one of (1) to (3). (5) The laminate of (4), wherein a layer made of metal is further laminated on the metal layer by plating, and the peel strength between the metal layer and the base film is 6 N / cm or more. [Effects of the Invention]

[0010] The highly adhesive film of the present invention has a primer layer of a specific composition on a substrate film made of a semi-aromatic polyamide resin, and therefore has excellent adhesion between the substrate film and the metal layer when a metal layer is formed on the primer layer by sputtering or electroless plating, and also has excellent plating solution resistance, heat resistance, blocking resistance, and flex resistance. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described in detail below. The adhesive film of the present invention has a primer layer on a film substrate made of a semi-aromatic polyamide resin. The primer layer contains an acid-modified polyolefin resin and a compound containing an epoxy group or an isocyanate group as a crosslinking agent.

[0012] The acid-modified polyolefin resin contains an ethylene component as a polyolefin component. The acid-modified polyolefin resin preferably contains an unsaturated carboxylic acid component as the acid component, which improves the adhesion between the substrate film and the metal layer and the film-forming properties of the primer layer. The unsaturated carboxylic acid component is introduced from an unsaturated carboxylic acid or its anhydride. Specific examples of the unsaturated carboxylic acid component include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, fumaric acid, crotonic acid, etc., as well as half esters and half amides of unsaturated dicarboxylic acids. Among these, acrylic acid, methacrylic acid, maleic acid, and maleic anhydride are preferred, with acrylic acid and maleic anhydride being particularly preferred.

[0013] The content of the acid-modified component in the acid-modified polyolefin resin is preferably 0.1 to 10 mass%, more preferably 0.2 to 8 mass%, and even more preferably 0.5 to 6 mass%. If the content of the acid-modified component is less than 0.1 mass%, the acid-modified polyolefin resin will have poor dispersibility in aqueous media and poor solubility in solvents, as described below, making it difficult to obtain a composition for forming a primer layer (primer composition), and may also result in insufficient adhesion to substrate films and metals.

[0014] The olefin component constituting the acid-modified polyolefin resin of the present invention must contain an ethylene component. The inclusion of an ethylene component provides a primer layer with good adhesion to substrate films and metals, and also provides excellent heat resistance, plating solution resistance, blocking resistance, and peel strength after plating lamination. The olefin component may contain an olefin other than ethylene, such as propylene, isobutylene, 1-butene, 1-pentene, or 1-hexene, which may be copolymerized with the ethylene component in the same resin, or may be mixed and used as different resins. The content of the ethylene component in the acid-modified polyolefin resin is preferably 80% by mass or more, and more preferably 90% by mass or more.

[0015] The acid-modified polyolefin resin may contain a (meth)acrylic acid ester component to improve adhesion between the substrate film and the metal layer. The content of the (meth)acrylic acid ester component in the acid-modified polyolefin resin is preferably 1 to 25 mass%, more preferably 2 to 22 mass%, even more preferably 3 to 20 mass%, and particularly preferably 5 to 18 mass%. If the content is less than 1 mass%, dispersion in an aqueous medium may be difficult and sufficient crosslinking may not occur, resulting in poor heat resistance. If the content exceeds 25 mass%, resistance to plating solutions may be insufficient.

[0016] Examples of the (meth)acrylic acid ester component include esters of (meth)acrylic acid with alcohols having 1 to 30 carbon atoms. Among these, esters of (meth)acrylic acid with alcohols having 1 to 20 carbon atoms are preferred from the viewpoint of easy availability. Specific examples of such compounds include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, dodecyl (meth)acrylate, and stearyl (meth)acrylate. Mixtures of these compounds may also be used. Among these, from the viewpoint of improving adhesion to semi-aromatic polyamide resin films and metal layers, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, hexyl acrylate, and octyl acrylate are more preferred, ethyl acrylate and butyl acrylate are more preferred, and ethyl acrylate is particularly preferred. Note that "(meth)acrylic acid" means "acrylic acid or methacrylic acid."

[0017] The acid-modified polyolefin resin may contain other components in addition to the above components. Examples of other components include alkenes and dienes having more than 6 carbon atoms, such as 1-octene and norbornenes, maleic acid esters, such as dimethyl maleate, diethyl maleate, and dibutyl maleate, (meth)acrylic acid amides, alkyl vinyl ethers, such as methyl vinyl ether and ethyl vinyl ether, vinyl esters, such as vinyl formate, vinyl acetate, vinyl propionate, vinyl pivalate, and vinyl versatate, as well as vinyl alcohols obtained by saponifying vinyl esters with a basic compound, 2-hydroxyethyl acrylate, glycidyl (meth)acrylate, (meth)acrylonitrile, styrene, substituted styrenes, carbon monoxide, and sulfur dioxide, and mixtures of these may also be used.

[0018] The acid-modified polyolefin resin may also contain an N-substituted amide structure in which the hydroxyl group of the carboxyl group is substituted with an N,N-dimethylamino group, an N,N-diethylamino group, or the like.

[0019] The melting point of the acid-modified polyolefin resin is preferably 50 to 150°C, more preferably 60 to 130°C, and even more preferably 70 to 110°C. If the melting point is below the above range, the cohesive strength may be weak, resulting in poor adhesiveness, and there is also a risk of blocking when the resin is laminated on a substrate film and wound into a roll. If the melting point exceeds the above range, there is a risk of reduced adhesion to the substrate film and metal layer.

[0020] Examples of acid-modified polyolefin resins include ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylic acid-maleic anhydride copolymers, acid-modified polyethylene, acid-modified ethylene-propylene resins, acid-modified ethylene-butene resins, acid-modified ethylene-propylene-butene resins, acid-modified styrene-ethylene-butylene-styrene, and ethylene-(meth)acrylic acid ester-unsaturated carboxylic acid copolymers obtained by further acrylic-modifying these acid-modified resins with (meth)acrylic acid esters or the like. Among these, ethylene-(meth)acrylic acid-maleic anhydride copolymers are preferred. Furthermore, the acid-modified polyolefin resins may be chlorinated in an amount of 5 to 40% by mass.

[0021] Examples of acid-modified polyolefin resins that can be used include commercially available products such as the Bondine series manufactured by Arkema, the Bestplast series manufactured by Evonik Japan, the Primacol series manufactured by Dow Chemical Company, the Umex series manufactured by Sanyo Chemical Industry Co., Ltd., the Admer series manufactured by Mitsui Chemicals, Inc., and the Toyotack series manufactured by Toyobo Co., Ltd. Commercially available solutions or aqueous dispersions can also be used, such as the Auroren series and Superclone series manufactured by Nippon Paper Chemicals Co., Ltd., the Zaixen series manufactured by Sumitomo Seika Chemicals Co., Ltd., the Unistall series and Chemipearl series manufactured by Mitsui Chemicals, Inc., the Hardlen series manufactured by Toyobo Co., Ltd., and the Arrowbase series manufactured by Unitika Ltd.

[0022] The primer layer included in the adhesive film of the present invention contains a compound containing an epoxy group or an isocyanate group as a crosslinking agent, which makes it possible to obtain an adhesive film that is superior in adhesion between the primer layer and the metal layer, adhesion between the base film and the metal layer, and heat resistance, compared to when other crosslinking agents are used.

[0023] The epoxy compound used in the present invention preferably has two or more epoxy groups in the molecule, more preferably three or more epoxy groups, from the viewpoint of improving adhesiveness and heat resistance. Examples of epoxy compounds include bisphenol A epoxy compounds, bisphenol F epoxy compounds, novolac epoxy compounds, alicyclic epoxy compounds, dicyclopentadiene epoxy compounds, biphenyl epoxy compounds, naphthalene epoxy compounds, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane polyglycidyl ether, pentaerythritol tetraglycidyl ether, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, and polyglycerol polyglycidyl ether. Among these, sorbitol polyglycidyl ether and polyglycerol polyglycidyl ether are preferred because of their high adhesiveness.

[0024] The epoxy equivalent (g / eq.) of the epoxy compound is 600 or less, preferably 400 or less, more preferably 300 or less, and even more preferably 200 or less. If it exceeds 600, adhesion between the base film and metal and sufficient heat resistance may not be obtained.

[0025] Examples of isocyanate compounds that can be used include diisocyanates, triisocyanates, and polyfunctional polyisocyanates derived from these. Examples include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, hexamethylene diisocyanate, bis(4-isocyanatocyclohexyl)methane, and hydrogenated diphenylmethane diisocyanate. Further examples include compounds derived from the diisocyanates, such as isocyanurates, adducts, biuret-type compounds, uretdione compounds, and allophanates of the diisocyanates, prepolymers having isocyanate residues (low polymers obtained from diisocyanates and polyols), triglycidyl isocyanurate, and complexes thereof. These may be used alone or in any combination of two or more.

[0026] The content of the crosslinking agent is 0.1 part by mass or more but less than 50 parts by mass, preferably 0.5 to 30 parts by mass, more preferably 1.0 to 10 parts by mass, and even more preferably 1.0 to 5.0 parts by mass, relative to 100 parts by mass of the acid-modified polyolefin resin. If the content of the crosslinking agent is less than 0.1 part by mass, the adhesion between the substrate film and metal and heat resistance will be poor, but if the content is 30 parts by mass or more, not only will the adhesion between the substrate film and metal be poor, but there is also the possibility of blocking when the film is wound into a roll.

[0027] (additives) In the easily adhesive film of the present invention, the primer layer may contain various additives, such as antioxidants, heat stabilizers, weather stabilizers, ultraviolet absorbers, pigments, dyes, organic or inorganic fine particles, crosslinking agents other than epoxy compounds or isocyanate compounds, fillers, antistatic agents, nucleating agents, etc., within the range that does not impair the effects of the present invention.

[0028] In particular, from the viewpoint of improving the slipperiness of the film, preventing blocking, and preventing scratches due to contact with rolls and the like during processing, the primer layer preferably contains organic and / or inorganic fine particles.

[0029] Examples of resins that can be used to make organic fine particles include polyethylene, polypropylene, polystyrene, silicone resin, nylon, acrylic resin, polyacrylonitrile, benzoguanamine-formaldehyde resin, melamine-formaldehyde resin, styrene-divinylbenzene copolymer, and acrylic-divinylbenzene copolymer.

[0030] Examples of inorganic fine particles include fine particles of silica, colloidal silica, alumina, alumina sol, tin oxide, titanium oxide, zinc oxide, niobium oxide, neodymium oxide, lanthanum oxide, zirconium oxide, cerium oxide, and magnesium oxide.

[0031] Among these, colloidal silica and acrylic particles are preferred from the viewpoint of smoothness, anti-blocking properties and transparency of the film.

[0032] The average particle size of the organic and inorganic fine particles is preferably 0.001 to 10 μm, more preferably 0.01 to 5 μm, and even more preferably 0.05 to 2 μm. If the average particle size is less than 0.001 μm, aggregation of the fine particles may reduce the transparency of the adhesive film. If the average particle size exceeds 10 μm, not only is it difficult to achieve sufficient slipperiness and blocking resistance, but the fine particles may also fall off the primer layer depending on the thickness of the primer layer.

[0033] The content of the organic and / or inorganic fine particles is preferably 0.1 to 10 parts by mass, more preferably 1 to 5 parts by mass, per 100 parts by mass of the acid-modified polyolefin resin constituting the primer layer. If the content is less than 0.1 part by mass, sufficient blocking resistance cannot be obtained, while if it exceeds 10 parts by mass, adhesion to the substrate film or metal deteriorates.

[0034] The primer layer may contain a resin other than the acid-modified polyolefin resin, as long as the effects of the present invention are not impaired. Examples of such resins include polyurethane resin, acrylic resin, and polyester resin. Among them, urethane resin is preferred from the viewpoint of improving the heat resistance and blocking resistance of the primer layer.

[0035] The thickness of the primer layer is preferably 0.01 to 10 μm, more preferably 0.05 to 1 μm, and even more preferably 0.1 to 0.5 μm. If the primer layer is too thin, not only will sufficient adhesion between the substrate film and the metal not be obtained, but the fine particles contained in the primer layer may fall off. If the primer layer is too thick, the transparency of the adhesive film may deteriorate and blocking may occur when the film is wound into a roll.

[0036] <Base film> The substrate film constituting the easily adhesive film of the present invention is made of a semi-aromatic polyamide resin. In the present invention, the semi-aromatic polyamide resin is composed of a dicarboxylic acid component and a diamine component, and has an aromatic component in the dicarboxylic acid component or the diamine component.

[0037] The dicarboxylic acid component constituting the semi-aromatic polyamide resin preferably contains terephthalic acid as a main component, and examples of the dicarboxylic acid component other than terephthalic acid include aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, and octadecanedioic acid, and aromatic dicarboxylic acids such as 1,4-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,2-naphthalenedicarboxylic acid, and isophthalic acid. The proportion of terephthalic acid in the dicarboxylic acid component is preferably 60 to 100 mol %.

[0038] The diamine component constituting the semi-aromatic polyamide resin preferably contains as a main component an aliphatic diamine having 4 to 15 carbon atoms, and examples of the aliphatic diamine having 4 to 15 carbon atoms include 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 2-methyl-1,8-octadecanediamine, 4-methyl-1,8-octanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,14-tetradecanediamine, 1,15-pentadecanediamine, etc. These may be used alone or in combination of two or more.

[0039] From the viewpoints of flexibility and film formability, the semi-aromatic polyamide resin is preferably a semi-aromatic polyamide resin comprising a dicarboxylic acid component consisting solely of terephthalic acid (100 mol % terephthalic acid) and a diamine component containing 1,9-nonanediamine and 2-methyl-1,8-octanediamine in a total amount of 60 to 100 mol % in the diamine component, or a semi-aromatic polyamide resin comprising a dicarboxylic acid component consisting solely of terephthalic acid (100 mol % terephthalic acid) and a diamine component containing 1,10-decanediamine.

[0040] By using the semi-aromatic polyamide resin as described above, it is possible to obtain an easily adhesive film that is excellent in flexibility, bending resistance, and heat resistance.

[0041] The semi-aromatic polyamide resin may be copolymerized with lactams such as ε-caprolactam, ζ-enantholactam, η-capryllactam, ω-laurolactam, etc., within the scope of the present invention.

[0042] The semi-aromatic polyamide resin can be produced by any known method, such as solution polymerization or interfacial polymerization using an acid chloride component and a diamine component as raw materials. Alternatively, a prepolymer can be produced using a dicarboxylic acid component and a diamine component as raw materials, and the prepolymer can be polymerized by melt polymerization or solid-state polymerization.

[0043] Furthermore, a terminal-capping agent may be used, if necessary, together with the diamine component, dicarboxylic acid component, and polymerization catalyst to produce the semi-aromatic polyamide resin. From the viewpoint of suppressing thermal decomposition and suppressing an increase in molecular weight, the terminal-capping agent is not particularly limited as long as it is a monofunctional compound that is reactive with the amino group or carboxyl group at the terminal of the semi-aromatic polyamide resin, and examples thereof include monocarboxylic acids, monoamines, acid anhydrides, monoisocyanates, monohalides, monoesters, and monoalcohols.

[0044] Commercially available semi-aromatic polyamide resins can be suitably used, such as "Genesta (registered trademark)" manufactured by Kuraray Co., Ltd., "Xecot (registered trademark)" manufactured by Unitika Ltd., "Reny (registered trademark)" manufactured by Mitsubishi Engineering Plastics Corporation, "Arlen (registered trademark)" manufactured by Mitsui Chemicals, Inc., and "Ultramid (registered trademark)" manufactured by BASF.

[0045] The substrate film is composed of the semi-aromatic polyamide resin, but may contain known additives such as antioxidants, stabilizers, UV absorbers, pigments, dyes, antistatic agents, plasticizers, antioxidants, organic or inorganic particles, fillers, crosslinking agents, etc., provided that the effects of the present invention are not impaired. It is desirable to add particles for the purpose of improving the slip properties and blocking resistance during the production and use of the film.

[0046] The substrate film in the present invention may be a composite film having a laminated structure of two or more layers. Examples of the composite film include a composite film in which no particles are contained in the inner layer but a small amount of particles are contained in the surface layer, and a composite film in which different or the same resins are used for the inner and surface layers. In terms of transparency, it is also preferable that the composite film does not contain particles.

[0047] Furthermore, the surface of the substrate film may be subjected to a pretreatment such as corona treatment, plasma treatment, ozone treatment, chemical treatment, or solvent treatment, taking into consideration the adhesion to the primer layer and the wettability of the surface.

[0048] The thickness of the substrate film is preferably 0.5 to 300 μm, more preferably 15 to 100 μm, even more preferably 25 to 75 μm, and particularly preferably 25 to 50 μm. If the thickness of the substrate film is less than 0.5 μm, not only is it difficult to manufacture, but the stiffness may also be weak, making handling difficult. On the other hand, if the thickness of the substrate film exceeds 300 μm, the stiffness may be too strong, making it difficult to use in applications requiring flexibility. The substrate film may be stretched.

[0049] <Method of manufacturing easy-adhesion film> The method for producing the adhesive film of the present invention by providing a primer layer on the surface of the substrate film will be described below. Specifically, either method can be used, including a method in which a liquid material (primer composition) for forming a primer layer is applied to a biaxially stretched substrate film (offline method), or a method in which a primer composition is applied to a substrate film before biaxial stretching, followed by stretching and heat treatment (inline method).

[0050] The primer composition is, for example, a composition in which the acid-modified polyolefin resin is dissolved or dispersed in an organic solvent or an aqueous medium, and can be obtained by the following methods, although there are no particular limitations on the method.

[0051] To obtain a primer composition, for example, an acid-modified polyolefin resin is dispersed in an aqueous medium containing water, a basic compound, and a hydrophilic organic solvent. The content of the hydrophilic organic solvent is preferably 1 to 50 mass %, more preferably 3 to 30 mass %, and even more preferably 5 to 25 mass %, of the primer composition to ensure uniform dispersion and to provide adequate wettability to the substrate.

[0052] Examples of hydrophilic organic solvents include alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, and cyclohexanol; ketones such as methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, and cyclohexanone; ethers such as tetrahydrofuran and dioxane; ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, and 3-methoxy acetate. Examples of the solvent include esters such as butyl, methyl propionate, ethyl propionate, diethyl carbonate, and dimethyl carbonate; glycol derivatives such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, and ethylene glycol ethyl ether acetate; and further, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 3-methoxy-3-methyl-1-butanol, methoxybutanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, ethyl acetoacetate, 1,2-dimethylglycerin, 1,3-dimethylglycerin, and trimethylglycerin.

[0053] Examples of basic compounds include ammonia, triethylamine, N,N-dimethylethanolamine, isopropylamine, aminoethanol, dimethylaminoethanol, diethylaminoethanol, ethylamine, diethylamine, isobutylamine, dipropylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, n-butylamine, 2-methoxyethylamine, 3-methoxypropylamine, 2,2-dimethoxyethylamine, monoethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine, pyrrole, and pyridine.

[0054] Furthermore, as a method for dissolving or dispersing the acid-modified polyolefin resin in an organic solvent, it is preferable to use an organic solvent containing an aliphatic hydrocarbon, an alicyclic hydrocarbon, a paraffinic solvent, or an isoparaffinic solvent. Specific examples include aliphatic hydrocarbons such as hexane, heptane, octane, nonane, decane, undecane, and dodecane; alicyclic hydrocarbons such as cyclohexane, cyclohexene, methylcyclohexane, dimethylcyclohexane, and ethylcyclohexane; and isoparaffinic solvents such as isododecane and Shellsol TG. These solvents may be used alone or in combination. The organic solvent may contain the hydrophilic organic solvent described above.

[0055] In addition, as a method for producing the easily adhesive film of the present invention, a method can be adopted in which a primer layer is formed on a release film prepared in advance, this layer is bonded to a base film, and then the release film is peeled off to transfer the primer layer to the base film.

[0056] In the in-line method, the primer composition is applied to the substrate film before biaxial stretching while the surface is still in a state of low degree of oriented crystallization, thereby improving adhesion to the formed primer layer. Furthermore, since the substrate film can be heat-treated at a higher temperature while in a tensed state, the adhesion of the primer layer can be improved without degrading the quality of the substrate film. The heat treatment temperature can be set to 250°C or higher, which is the heat-setting temperature of the substrate film. At this temperature, oriented crystallization progresses in the primer layer along with the substrate film. Furthermore, the reaction between the acid-modified polyolefin resin and the crosslinking agent in the primer layer during heat-setting is expected to improve the primer layer's performance, such as adhesion to the substrate film and heat resistance.

[0057] Furthermore, the in-line method is advantageous in terms of cost, since it not only simplifies the manufacturing process but also allows the coating film to be made thinner than the off-line method. When a simultaneous biaxial stretching method is employed in the production of a substrate film, a primer composition is applied to an unstretched film, dried, and then biaxially stretched to a stretching ratio of about 2 to 4 in both the longitudinal and transverse directions at a temperature ranging from the Tg of the resin constituting the substrate film to 50°C higher than the Tg. A preliminary longitudinal stretching of about 1 to 1.2 may be performed before feeding the film into the simultaneous biaxial stretching machine.

[0058] Furthermore, when the sequential biaxial stretching method is adopted, it is preferable from the viewpoint of simplicity and operational reasons to apply a primer composition to a substrate film stretched in a uniaxial direction, and then further stretch the substrate film in a direction perpendicular to the uniaxial direction.

[0059] The primer composition can be applied to the substrate film by any known method, such as gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, dip coating, or brush coating. These methods can be used to apply the primer composition uniformly to the surface of the substrate film.

[0060] After applying the primer composition to a substrate film, the medium can be removed by drying and heat treatment, and an easily adhesive film consisting of a dense coating film with the primer layer adhered closely to the substrate film can be obtained. The adhesive film of the present invention has a primer layer on at least one side of the base film, and the primer layer may be provided on both sides of the base film. Furthermore, a layer other than the primer layer may be provided on the side of the base film that does not have the primer layer.

[0061] The substrate film in the present invention may be a composite film having a laminated structure of two or more layers, such as a composite film in which no particles are contained in the inner layer but a very small amount of particles are contained in the surface layer, or a composite film in which different or the same resins are used for the inner and surface layers.

[0062] In addition, the surface of the substrate film may be subjected to a pretreatment such as corona treatment, plasma treatment, ozone treatment, chemical treatment, or solvent treatment, taking into consideration adhesion to the primer layer.

[0063] The laminate of the present invention has a metal layer on the primer layer of the above-described easily adhesive film of the present invention. The metal constituting the metal layer is not particularly limited, and examples thereof include copper, nickel, aluminum, silver, tin, lead, chromium, gold, magnesium, nickel, iron, zinc, zirconium, titanium, silicon, etc. These metals may be used alone or as an alloy of two or more metals. Among these, from the viewpoints of conductivity and cost, it is preferable to use copper or an alloy containing copper.

[0064] The method for laminating a metal layer on the primer layer of the highly adhesive film of the present invention is not particularly limited, and examples include lamination using metal foil, sputtering, and electroless plating. From the viewpoint of ease of controlling the film thickness, sputtering or electroless plating is preferred.

[0065] When a metal layer is laminated on the primer layer of the adhesive film of the present invention by sputtering or electroless plating, the metal layer can be further thickened by electroplating. The metal laminated by sputtering or electroless plating and the metal applied by electroplating may be different metals. Furthermore, after plating, etching may be performed to form circuits, etc.

[0066] The laminate of the present invention can be used, for example, as a bonding sheet, a resin-coated copper foil, a coverlay film, a printed wiring board, a copper-clad laminate, a flat cable, a circuit board for tape automated bonding, and the like. [Example]

[0067] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples. 1. Evaluation Method (1) Adhesion between the base film and primer layer The primer composition described below was applied to a substrate film described below to obtain an easily adhesive film, and the adhesion was evaluated by the cross-cut method according to the method described in JIS K 5600, based on the remaining rate of the primer layer after peeling with cellophane tape. In practice, the remaining rate is preferably 85% or more.

[0068] (2) Adhesion to metal layers A primer composition was applied to a substrate film (described below) and heated for 15 seconds in a hot air dryer set at 240°C to form a primer layer, resulting in an easily adhesive film. The resulting easily adhesive film was then placed inside a sputtering deposition apparatus, the pressure inside the apparatus was reduced, argon gas was introduced, and sputtering was performed using copper as the target. The discharge power and sputtering time required for sputtering were appropriately adjusted to form a 0.1 μm-thick copper layer on the easily adhesive film's primer layer. This copper layer was subjected to a cross-cut test in accordance with JIS K5600-5-6, and the peeling state of the copper layer was visually evaluated using a scale of 0 to 5. In the present invention, it is preferable that the material falls into any one of categories 0, 1 and 2. Category 0: The edges of the cut are completely smooth and there is no peeling on any of the grids. Category 1: Small peeling of the coating at the intersection of the cuts. The affected area of ​​the cross-cuts does not significantly exceed 5%. Category 2: The coating is flaking along the edges of the cuts and / or at the intersections. The cross-cut area is clearly more than 5% affected but not more than 15%. Category 3: The coating has partially or completely peeled off significantly along the edges of the cuts and / or partially or completely peeled off in various areas of the mesh. The cross-cut area is clearly more than 15% affected but not more than 35%. Category 4: The coating is partially or completely torn off in large areas along the edges of the cuts and / or partially or completely torn off in several sections. Not more than 35% of the cross-cut area is affected. Category 5: Any degree of peeling that cannot be classified as Category 4.

[0069] (3) Resistance of the primer layer composition to plating solution In a 3,000 mL glass graduated cylinder, 150 g of copper(II) sulfate pentahydrate (special reagent grade, manufactured by Nacalai Tesque), 1,200 g of ion-exchanged water, 380 g of sulfuric acid (special reagent grade, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 0.275 g of hydrochloric acid (special reagent grade, concentration 35-37%, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 2 g of Lucent Copper A (manufactured by Meltex Corporation), 2 g of Lucent Copper S (manufactured by Meltex Corporation), and 8 g of Lucent Copper SC (manufactured by Meltex Corporation) were added in this order and stirred with a glass rod until the mixture was homogeneous. Subsequently, ion-exchanged water was poured into the same graduated cylinder and the volume was diluted to 2,000 mL. The mixture was further stirred with a glass rod and used as the plating solution for the experiment. The primer composition was poured into a Teflon (registered trademark) container and heated at 50°C for 48 hours and then at 150°C for 1 minute to obtain a coating film with a thickness of 0.5 mm. This coating film was separated from the Teflon (registered trademark) container and cut into five square test pieces with sides of 2 cm. The total weight of these five test pieces was measured and recorded. Five of the above test pieces were placed in a 100 mL polyethylene bottle, which was then filled with plating solution and sealed. The bottle was shaken at a rate of 60 cycles / min for three days in a shaker equipped with a water bath set at 50°C. All test pieces were then removed from the plating solution, thoroughly washed with water, and heated in a hot air dryer set at 60°C for 15 hours to completely remove the water. The total weight of the five test pieces was then measured, and the weight change rate due to immersion in the plating solution was calculated using the following formula. From a practical standpoint, a score of △ or higher is preferable. Weight change rate (%) = 100 × (total weight before immersion in plating solution - total weight before immersion in plating solution) / total weight before immersion in plating solution ○: Absolute value of weight change rate is less than 4% △: Absolute value of weight change rate is 4% or more and less than 10% ×: Absolute value of weight change rate is 10% or more

[0070] (4) Blocking resistance of primer layer A primer composition was applied to the substrate film described below and heated for 15 seconds in a hot air dryer set at 240°C to form a primer layer, resulting in an easily adhesive film. This easily adhesive film was cut into squares with sides of 5 cm, and 20 identical sheets were stacked with the primer layer facing up. A 10 kg load was placed on top of the film and heated for 24 hours in a hot air dryer set at 60°C. The load was then removed from the easily adhesive film and allowed to cool to room temperature. The adhesion between the primer layer surface and the substrate film surface was then examined to evaluate the blocking resistance. From a practical standpoint, a rating of △ or higher is preferable. ◎: Can be peeled off without any resistance. ◯: Weak resistance was felt when peeling off, and a peeling sound was heard, but no whitening was observed on the primer layer after peeling. △: Weak resistance was felt when peeling off, a peeling sound was heard, and whitening of the primer layer was observed after peeling off. ×: Strong resistance was felt when peeling off, and whitening was observed on the primer layer after peeling off.

[0071] (5) Adhesion strength between the base film and the metal layer (peel strength after plating) The copper layer-attached laminate prepared in (2) was electroplated with copper using the plating solution prepared in (3) to form a 5 μm-thick copper layer. The laminate was then thoroughly rinsed with water, the water droplets were wiped off, and the laminate was air-dried at room temperature for 3 days. An adhesive tape manufactured by TESA (product number TESA7475) was attached to the edge of the copper layer of the laminate, and the adhesive strength between the copper layer of the laminate and the substrate film was measured in a thermostatic chamber at 23°C using a tensile tester (Shimadzu Corporation Autograph AGS-100B) at a peel angle of 90° and a peel rate of 50 mm / min. For practical purposes, a peel strength of 6 N / cm or more is preferred, 8 N / cm or more is more preferred, and 9.5 N / cm or more is particularly preferred.

[0072] (6) Solder heat resistance (heat resistance) A 2.5cm x 2.5cm sample of the laminate with the copper layer prepared in (5) was dried at 120°C for 30 minutes and then immersed in a molten solder bath at 260°C for 1 minute to evaluate the solder heat resistance according to the following criteria. From a practical standpoint, a rating of △ or better is preferable. 〇: No swelling △: Slight swelling ×: Large swelling

[0073] (7) Flexibility The adhesive film obtained in the examples was cut into a 30 x 100 mm rectangle to prepare a sample. The short sides of the sample were fixed to a durability tester (Yuasa System Equipment Co., Ltd. DLDMLH-FS) so that the minimum distance between the two opposing sides was 1.5 mm. A bending test in which the front side of the sample was folded 180 degrees (with the adhesive layer facing inward) was performed up to 100,000 times, and the bending portion was visually inspected for cracks, creases, whitening, breaks, etc. The bending portion was inspected visually every 10,000 folding cycles. For samples that showed no change in the bending portion or that showed changes in the bending portion but were not problematic for practical use, the bending test was continued. For samples that showed obvious cracks, creases, whitening, breaks, etc. in the bending portion, the test was discontinued. For samples where the test was discontinued, the number of folding cycles at which changes were observed was recorded. After 100,000 folding cycles, the bending resistance was evaluated according to the following criteria. ◯: No cracks or breaks were observed at the bent portion, and no break marks or whitening were observed. △: No cracks or breaks were observed at the bent portion, but break marks remained and whitening occurred. ×: Cracks or breakage occurred at the bent portion.

[0074] The following materials and substrates were used for the primer composition. Manufacturing Example 1 Preparation of aqueous dispersion of acid-modified polyolefin resin (E-1) Using a stirrer equipped with a heater-equipped sealable pressure-resistant 1 L glass container, 100 g of acid-modified polyolefin resin [ethylene-ethyl acrylate-maleic anhydride copolymer, ethylene 92% by mass, ethyl acrylate 6% by mass, maleic anhydride 2% by mass, melting point 105 ° C.], 80 g of isopropanol, 4.0 g of N,N-dimethylethanolamine, and 220 g of water were charged into the glass container and heated and stirred at 130 ° C. for 60 minutes. After cooling to room temperature with stirring, 150 g of water was added, and the water and isopropanol were distilled off under reduced pressure using an evaporator to obtain an aqueous dispersion of polyolefin resin particles (E-1).

[0075] Preparation of aqueous dispersion of acid-modified polyolefin resin (E-2) An acid-modified polyolefin resin [ethylene-ethyl acrylate-maleic anhydride copolymer, 80% by mass of ethylene, 18% by mass of ethyl acrylate, 2% by mass of maleic anhydride, melting point 83°C] was used. An aqueous dispersion (E-2) was obtained in the same manner as in the case of E-1.

[0076] Preparation of aqueous dispersion of acid-modified polyolefin resin (E-3) 280 g of a propylene-ethylene copolymer (propylene / ethylene=81.8 / 18.2 (mass ratio), weight average molecular weight 85,000) was heated and melted in a four-neck flask under a nitrogen atmosphere. Then, while maintaining the system temperature at 180°C, 35.0 g of maleic anhydride as an unsaturated carboxylic acid and 6.0 g of di-t-butyl peroxide as a radical generator were added over 2 hours with stirring, followed by a 1-hour reaction. After the reaction was completed, the resulting reaction product was poured into a large amount of acetone to precipitate a resin. This resin was further washed several times with acetone to remove unreacted maleic anhydride, and then dried under reduced pressure in a vacuum dryer to obtain an acid-modified polyolefin resin [mass ratio: propylene 75.4 / ethylene 16.8 / maleic anhydride 7.8, melting point 70°C]. Using the obtained resin, a milky white polyolefin resin aqueous dispersion (E-3) was obtained in the same manner as in the method described in Japanese Patent No. 3759160 (Japanese Patent Application No. 2005-506371).

[0077] Preparation of aqueous dispersion of acid-modified polyolefin resin (E-4) 280 g of a propylene-butene copolymer (propylene / butene=80 / 20 (mass ratio), weight average molecular weight 100,000) was heated and melted in a four-neck flask under a nitrogen atmosphere. Then, while maintaining the system temperature at 170°C, 25.0 g of maleic anhydride as an unsaturated carboxylic acid and 6.0 g of dicumyl peroxide as a radical generator were added over 1 hour, and the mixture was allowed to react for 1 hour. After the reaction was completed, the resulting reaction product was poured into a large amount of acetone to precipitate a resin. This resin was further washed several times with acetone to remove unreacted maleic anhydride, and then dried under reduced pressure in a vacuum dryer to obtain an acid-modified polyolefin resin [mass ratio: propylene 76.4 / ethylene 19.1 / maleic anhydride 4.5, melting point 70°C]. Using the obtained resin, an aqueous dispersion (E-4) was obtained in the same manner as in the case of E-1, except for the above.

[0078] Production of acid-modified polyolefin resin solution (E-5) A nitrogen-purged separable flask was charged with 25 g of styrene-ethylene-butylene-styrene resin (styrene content 15% by mass), 80 g of xylene (manufactured by Wako Pure Chemical Industries, Ltd.), and 3 g of maleic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.). The mixture was then heated at 30 rpm for 30 minutes at a system temperature of 130°C to dissolve the resin. Next, 2.4 g of dicumyl peroxide dissolved in 10 g of xylene was added dropwise over 30 minutes with stirring, and the mixture was allowed to react at 130°C for 4 hours. After the reaction was completed, the resulting reaction mixture was poured into a large amount of acetone to precipitate the resin. This resin was further washed several times with acetone to remove unreacted maleic anhydride, and then dried under reduced pressure to obtain a SEBS resin with a maleic anhydride content of 2.6% by mass. The resulting resin was stirred in a solvent of 48% by mass of methylcyclohexane and 20% by mass of methyl ethyl ketone so that the solid content concentration of the resulting resin was 20% by mass, to obtain an acid-modified polyolefin solution (E-5).

[0079] Epoxy compounds C-1: Nagase ChemteX Corporation, Denacol EX-614, sorbitol polyglycidyl ether, multifunctional epoxy resin (having 3 or more epoxy groups), epoxy equivalent 167 C-2: Nagase ChemteX Corporation, Denacol EX-832, polyethylene glycol diglycidyl ether, bifunctional epoxy resin (having two epoxy groups), epoxy equivalent 284 C-3: Nagase ChemteX Corporation, Denacol EX-421, diglycerol polyglycidyl ether, multifunctional epoxy resin, epoxy equivalent 159 C-4: Nagase ChemteX Corporation, Denacol EX-861, polyethylene glycol diglycidyl ether, bifunctional epoxy resin, epoxy equivalent 551

[0080] Isocyanate compounds D-1: Mitsui Chemicals, Inc., Stabio D-370N, 1,5-pentamethylene diisocyanate

[0081] Oxazoline compounds W-1: Nippon Shokubai, Epocross, WS-700

[0082] Colloidal silica (particles) P-1: Fuso Chemical Co., Ltd., Quattron PL-7 Acrylic fine particles P-2: (Nippon Shokubai Eposter IX-3-BR-WA-01-02)

[0083] Polyurethane aqueous dispersion U-1: Polyester polyurethane (Tg: approx. 70°C, Mw: 40300, acid value: 33 mg KOH / g)

[0084] The following resins constituting the substrate film and the substrate film were used. (1) Semi-aromatic polyamide resin Semi-aromatic polyamide resin (T-1) 1343 g of 1,9-nonanediamine (NDA), 237 g of 2-methyl-1,8-octanediamine (MODA), 1627 g of terephthalic acid (TPA) (average particle size 80 mm) (NMDA:MODA:TPA = 85:15:99, molar ratio), 48.2 g of benzoic acid (BA) (4.0 mol % with respect to the total number of moles of dicarboxylic acid components and diamine components), 3.2 g of phosphorous acid (PA) (0.1 mass % with respect to the total amount of dicarboxylic acid components and diamine components), and 1100 g of water were placed in a reactor, and the atmosphere was replaced with nitrogen. The above raw materials were stirred at 80°C for 0.5 hours at 28 revolutions per minute, then heated to 230°C and heated at 230°C for 3 hours. After cooling, the reaction product was removed. The reaction product was pulverized and then heated in a dryer under a nitrogen stream at 220°C for 5 hours to undergo solid-state polymerization. The solid-phase polymer was melt-kneaded at a cylinder temperature of 320°C, extruded into a strand, cooled, and cut to prepare pellets of semi-aromatic polyamide resin (T-1).

[0085] (2) Preparation of silica-containing master chips 98 parts by mass of the semi-aromatic polyamide resin (T-1) obtained in Production Example 1 and 2 parts by mass of silica (Sylysia 310P, manufactured by Fuji Silysia Chemical Ltd., average particle size 2.7 μm) were melt-kneaded to produce a master chip (M1) containing 2% by mass of silica.

[0086] Production of semi-aromatic polyamide film (F-1) The semi-aromatic polyamide resin (T-1), the heat stabilizer, and the master chip (M1) were mixed so that the amounts of the heat stabilizer (Sumitomo Chemical Co., Ltd., "Sumilizer GA-80") and the silica were 0.2 and 0.1 parts by mass, respectively, per 100 parts by mass of the semi-aromatic polyamide resin (T-1). This mixture was melted in a 65 mm single-screw extruder with cylinder temperatures set to 295°C (front stage), 320°C (middle stage), and 320°C (rear stage), extruded into a sheet from a T-die set at 320°C, and cooled by electrostatically adhering it to a cooling roll set at a surface temperature of 40°C, yielding a substantially unoriented, unstretched sheet with a thickness of 205 μm. Next, biaxial stretching was performed using a flat-type sequential stretching machine. First, the unstretched film was heated to 130°C using roll heating or infrared heating, and stretched in the machine direction (longitudinal direction) at a stretch ratio of 2.3 to obtain a machine-stretched film. Subsequently, while both ends of the machine-stretched film were held with clips, it was introduced into a transverse stretching machine and subjected to sequential biaxial stretching. Inside the transverse stretching machine, the preheating zone temperature was 110°C, the stretching zone temperature was 148°C, and the stretch ratio was 1.8. After stretching, the film was heat-set at 270°C for 5 seconds in the first half of the heat-setting zone, and immediately thereafter at 275°C for 5 seconds in the second half of the heat-setting zone, followed by relaxation in the width direction at a relaxation rate of 3.0%, to obtain a 50 μm-thick semi-aromatic polyamide film F-1.

[0087] Example 1 The aqueous dispersion (E-1) of the acid-modified polyolefin resin and the epoxy compound (C-1) were mixed so that the solid content mass ratio was 100 / 1 to obtain a primer composition. The obtained primer composition was applied to a corona-treated semi-aromatic polyamide film (F-1) so that the thickness after drying would be 0.5 μm, and the coating was dried at 150°C for 30 seconds to form a primer layer, thereby obtaining an easily adhesive film. A laminate in which a metal layer was laminated on the primer layer of the adhesive film was obtained by the methods described in evaluation methods (2), (4) and (5).

[0088] Examples 2 to 28 As shown in Tables 1 and 2, acid-modified polyolefin resins, crosslinking agents, and particles were mixed with different types and contents to prepare primer compositions, and the primer compositions were applied so that the thickness of the primer layer was as shown in Tables 1 and 2 to obtain easy-adhesion films. The same operations as in Example 1 were performed to obtain easy-adhesion films and laminates. The evaluation results are summarized in Tables 1 and 2.

[0089] [Table 1]

[0090] [Table 2]

[0091] Example 29 The semi-aromatic polyamide resin (T-1), the heat stabilizer, and the master chip (M1) were mixed so that the amounts of the heat stabilizer (Sumitomo Chemical Co., Ltd., "Sumilizer GA-80") and the silica were 0.2 and 0.1 parts by mass, respectively, per 100 parts by mass of the semi-aromatic polyamide resin (T-1). This mixture was melted in a 65 mm single-screw extruder with cylinder temperatures set to 295°C (front stage), 320°C (middle stage), and 320°C (rear stage), extruded into a sheet from a T-die set at 320°C, and cooled by electrostatically adhering it to a cooling roll set at a surface temperature of 40°C, yielding a substantially unoriented, unstretched sheet with a thickness of 205 μm. Next, the unstretched film was heated to 130 ° C. using roll heating or infrared heating, etc., in a flat-type sequential stretching machine and stretched in the longitudinal direction (longitudinal direction) at a stretch ratio of 2.3 times. After the longitudinal stretching, the unstretched film was subsequently coated with the same primer composition as in Example 1 so that the thickness of the easy-adhesion layer after drying and stretching was 0.5 μm. Then, while holding both ends of the longitudinally stretched film with clips, it was introduced into a transverse stretching machine and subjected to sequential biaxial stretching. Inside the transverse stretching machine, the preheating section temperature was 110 ° C., the stretching section temperature was 148 ° C., and the stretch ratio was 1.8 times. After stretching, the film was heat-set at 270 ° C. for 5 seconds in the first half of the heat-setting zone, and immediately thereafter at 275 ° C. for 5 seconds in the second half of the heat-setting zone, and then relaxed at a relaxation rate of 3.0% in the width direction to obtain a biaxially stretched easy-adhesion film with a thickness of 50 μm.

[0092] Examples 30 and 31 The same procedure as in Example 29 was carried out except that the conditions were changed to those shown in the table, to obtain an easily adhesive film and a laminate.

[0093] Examples 32 to 34 (Examples using transparent film substrate) The semi-aromatic polyamide resin (T-1) and a heat stabilizer (Sumitomo Chemical Co., Ltd., "Sumilizer GA-80") were mixed so that the amount of the heat stabilizer was 0.2 parts by mass per 100 parts by mass of the semi-aromatic polyamide resin (T-1). This mixture was melted in a 65 mm single-screw extruder with cylinder temperatures set to 295°C (front stage), 320°C (middle stage), and 320°C (rear stage), extruded into a sheet from a T-die set at 320°C, and cooled by electrostatically adhering it to a cooling roll set at a surface temperature of 40°C, yielding a substantially unoriented, unstretched sheet with a thickness of 205 μm. Next, the unstretched film was heated to 130 ° C. by roll heating or infrared heating using a flat-type sequential stretching machine, and stretched in the longitudinal direction (longitudinal direction) at a stretching ratio of 2.3 times. After the longitudinal stretching, a primer composition was applied to the unstretched film, which was then mixed with an aqueous dispersion of acid-modified polyolefin resin (E-1), an aqueous polyurethane dispersion (U-1), an epoxy compound (C-1), and colloidal silica (P-1) in a solids mass ratio of 80 / 20 / 3 / 5, so that the thickness of the easy-adhesion layer after drying and stretching was 0.5 μm. Then, the longitudinally stretched film was continuously guided to a transverse stretching machine while holding both ends with clips, and sequential biaxial stretching was performed. Inside the transverse stretching machine, the preheating section temperature was 110 ° C., the stretching section temperature was 148 ° C., and the stretching ratio was 1.8 times. After stretching, the film was heat-set at 270°C for 5 seconds in the first half of the heat-setting zone, and immediately thereafter at 275°C for 5 seconds in the second half of the heat-setting zone, followed by a relaxation treatment at a relaxation rate of 3.0% in the width direction, to obtain a biaxially stretched, easily adhesive film having a thickness of 50 μm.

[0094] Comparative Examples 1 to 7 The same operations as in Example 1 were carried out, except that the types and contents of the acid-modified polyolefin resin, crosslinking agent, and particles were changed to meet the conditions shown in Table 3, to obtain an easily adhesive film and a laminate.

[0095] [Table 3]

[0096] Comparative Example 8 The substrate film used in Example 1 without providing a primer layer was subjected to various evaluations.

[0097] Comparative Examples 9 to 11 The substrate films used were polyethylene terephthalate resin film (manufactured by Unitika Ltd., trade name "Emblet", thickness 50 μm), polyimide resin film (manufactured by Toray DuPont Co., Ltd., trade name "Kapton 200H", thickness 50 μm), and polyethylene naphthalate resin film (manufactured by Toyobo Co., Ltd., trade name "Teonex", thickness 50 μm).

[0098] As shown in Examples 1 to 34, the highly adhesive film of the present invention had excellent adhesion to the substrate film, adhesion to the metal layer, peel strength of the plating layer, resistance to plating solution, heat resistance, blocking resistance, and flex resistance.

[0099] On the other hand, as shown in the comparative examples, when a crosslinking agent outside the scope of the present invention was used, adhesion to the metal layer and heat resistance were poor (Comparative Example 1). Comparative Example 2, which used an acid-modified polyolefin resin outside the scope of the present invention, was inferior in adhesion to the metal layer, peel strength of the plating layer, heat resistance, plating solution resistance, and blocking resistance. Comparative Example 7, which did not contain an acid-modified polyolefin resin, was inferior in adhesion to the metal layer, peel strength of the plating layer, and heat resistance. Furthermore, when the primer layer did not contain a crosslinking agent (Comparative Examples 3, 4, 5, and 6), the adhesion to the substrate film, adhesion to the metal layer, heat resistance, peel strength after plating lamination, and blocking resistance were poor. Furthermore, when no primer layer was provided, the adhesion between the substrate film and the metal layer, the peel strength of the plating layer, and the heat resistance were poor (Comparative Example 8).

[0100] Furthermore, when a film other than a semi-aromatic polyamide film was used as the substrate film as in Comparative Examples 9 to 11, the heat resistance and flex resistance were poor.

Claims

1. An easily adhesive film having a primer layer containing an acid-modified polyolefin resin and a crosslinking agent on a film substrate made of a semi-aromatic polyamide resin, the acid-modified polyolefin resin contains an ethylene component as a polyolefin component, An easily adhesive film, wherein the crosslinking agent is a compound containing an epoxy group or an isocyanate group.

2. 2. The adhesive film according to claim 1, wherein a copper layer having a thickness of 0.1 μm is formed on the primer layer by sputtering or electroless plating, and when the peel resistance test described below is performed, the adhesive film satisfies the following conditions. [Peel resistance test] Cross-cut test conforming to JIS K5600-5-6. [conditions] The peeling state of the copper layer is either Class 0, Class 1 or Class 2.

3. The adhesive film according to claim 1 or 2, wherein the primer layer contains organic and / or inorganic fine particles.

4. A laminate comprising a metal layer on the primer layer of the adhesive film according to claim 1 or 2.

5. 5. The laminate according to claim 4, wherein a layer made of metal is further laminated on the metal layer by plating, and the peel strength between the metal layer and the substrate film is 6 N / cm or more.

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