CN107922655B

CN107922655B - Film for metal film lamination

Info

Publication number: CN107922655B
Application number: CN201680046478.5A
Authority: CN
Inventors: 筑摩和哉; 佐佐木伸明; 石田干祥; 川崎阳一
Original assignee: Mitsubishi Chemical Corp
Current assignee: Mitsubishi Chemical Corp
Priority date: 2015-09-30
Filing date: 2016-02-29
Publication date: 2021-11-19
Anticipated expiration: 2036-02-29
Also published as: CN107922655A; KR20200023550A; TW201712086A; TWI734682B; KR20180018686A; KR102216456B1; WO2017056523A1

Abstract

The invention provides a patterned film for metal film lamination, which has good adhesion to a metal layer even under high temperature and high humidity conditions, does not discolor the metal layer, can inhibit oligomer precipitation generated during heat treatment, and can avoid the bad condition caused by poor patterning even when the patterned metal layer is deformed in shape, the metal film lamination film is patterned finely, the pattern width is designed to be narrower, and the film is designed to be used in the type of high-sensitivity wiring substrate with high-precision response of the wiring substrate. Provided is a film for laminating a metal film, which has a coating layer formed from a coating liquid containing a crosslinking agent in an amount of 70 wt% or more relative to a nonvolatile component on at least one polyester film surface, and which satisfies the following formula (1). In the formula, | SMD-STD | < 0.4 … (1) (in the above formula, SMD represents the shrinkage rate (%) in the film Moving Direction (MD), STD represents the shrinkage rate (%) in The Direction (TD) perpendicular to the film moving direction), and the heating conditions were 150 ℃ and 90 minutes.

Description

Film for metal film lamination

Technical Field

The present invention relates to a film for metal film lamination in which a patterned metal layer is laminated, and more particularly to a film which has good adhesion to a metal layer, good patterning of a metal layer, and good pattern shape, and is suitable for use in, for example, a flexible double-sided circuit board, and a component for a touch panel (for example, a conductive film).

Background

Conventionally, polyester films have been used in various fields by taking advantage of their mechanical properties, optical properties, dimensional stability, and the like. As an example thereof, a flexible substrate application can be exemplified.

In recent years, electronic devices such as televisions, cellular phones, notebook personal computers, digital cameras, game machines, and the like have been rapidly reduced in size, thickness, and weight, and materials used for these devices have been demanded to have high density and high performance, which can accommodate components in a small space.

As a material that can meet such a demand, a flexible double-sided printed wiring board that is thin, can be folded into a narrow space, and has excellent bending resistance is widely used.

However, a flexible double-sided printed wiring board (flexible circuit board) used for a movable portion of a folding mobile phone, a sliding mobile phone, or the like, which is highly demanded for high density, is required to have more excellent flexibility. In the structure of the conventional flexible printed wiring board, there is a technical problem that disconnection occurs after long-term use in the case of multilayering, and it is not satisfactory for applications requiring high bending resistance.

Therefore, as a countermeasure for achieving high bending resistance, for example, it is necessary to make the flexible double-sided printed wiring board itself thin, and studies are being made to make the insulating film itself thin, for example.

On the other hand, due to the shrinkage rate characteristic which is a characteristic of the polyester film, there is a technical problem that the shape (for example, lattice shape) of the patterned metal layer is deformed and the wiring board cannot respond (react), and it is not satisfactory for an application requiring high response of the wiring board.

Therefore, as a countermeasure for achieving a higher wiring board height, for example, a study for preventing pattern deformation of a flexible double-sided printed wiring board has been conducted.

As an example of a flexible double-sided printed circuit board, patent document 1, for example, describes a metal film lamination film having a 3-layer metal film lamination film structure in which a copper foil is bonded to an insulating film with an adhesive.

However, in the film structure for stacking 3 metal films, in order to obtain a desired wiring pattern, etching is performed not only in a direction perpendicular to the substrate surface but also in a side etching in which etching is performed in a planar direction (side wall surface) at the time of etching, and there is a tendency that the cross-sectional shape of the wiring portion is easily formed into a trapezoidal shape with a wide bottom portion, and as a result, there is a problem that it is difficult to make a pitch of the wiring pattern narrow. In this structure, since the copper foil is adhered to the surface of the insulating film via the adhesive layer, there is a natural limit to the thinning of the conductor layer due to the copper foil.

As a film forming method for stacking the 2 metal films, for example, patent document 2 describes forming a copper coating film layer having a uniform thickness on an insulating film by a plating method. The method includes the following manufacturing method: before forming the copper coating layer by electroplating, a base metal layer containing a metal other than copper, such as chromium, chromium oxide, or nickel, is formed on the insulating film to a predetermined thickness by a dry plating method such as vacuum deposition, sputtering, or ion plating

Left and right, thereafter, a thin copper layer by a dry plating method and an electroless copper plating film by electroless plating are formed in this order.

In patent document 3, as a material of a flexible double-sided printed wiring board, adhesion between an insulating film and a base metal layer is insufficient in a 2-layer metal film lamination film. Therefore, the base layer present between the insulating film and the metal layer needs to have good adhesion to the insulating film and good adhesion to the metal layer stacked on the base layer.

When the material of the flexible printed wiring board is used under high temperature and high humidity conditions, the material of the flexible printed wiring board cannot be used under high temperature and high humidity conditions due to insufficient adhesion caused by the influence of the underlying layer present between the insulating film and the metal layer and discoloration caused by oxidation of the metal layer. Therefore, under high temperature and high humidity conditions, the base layer present between the insulating film and the metal layer needs to have good adhesion to the insulating film and good adhesion to the metal layer stacked on the base layer, and also needs to be free from discoloration due to oxidation of the metal layer.

For example, in the process of laminating a metal layer by sputtering or in the heating step after patterning the laminated metal layer, thermal damage to the film surface of the polyester film is large, and oligomers (mainly cyclic trimer) tend to precipitate from the film, which may cause contamination of the production apparatus, or film surface protrusion due to precipitation of oligomers on the film surface.

In recent years, as the performance of final parts has been improved, the patterning of the metal film lamination film has become finer and the pattern width has been designed to be narrower.

In general, particles are blended into a polyester film substrate mainly for the purpose of imparting slipperiness and preventing the occurrence of scratches in each step. If the surface roughness of the polyester film substrate is increased by adding more particles and designing, the handling property at the time of processing the substrate is improved, but when the aggregation of the particles is present in the pattern portion of the film for metal film lamination, a problem of poor patterning of the film for metal film lamination often occurs.

On the other hand, when the particles are not mixed in the polyester substrate, damage that occurs when the film passes through a roll pass (roll pass) in each step tends to occur on the entire surface of the film, which often causes a problem of poor patterning of the metal film lamination film, and it is extremely difficult to process a good metal film lamination film.

In addition, with the recent increase in performance of final parts, a wiring board with good response and high sensitivity has been designed.

The polyester film substrate has a shrinkage rate characteristic of shrinking after heating. Due to the difference (Δ S) in shrinkage between the film Moving Direction (MD) and The Direction (TD) orthogonal thereto, the shape of the patterned metal layer tends to be deformed, and the response of the wiring board tends to be lowered, so that a wiring board with high sensitivity cannot be manufactured, and it is extremely difficult to process a film for stacking a patterned metal film into a good one.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 6-132628

Patent document 2: japanese laid-open patent publication No. H8-139448

Patent document 3: japanese laid-open patent publication No. 6-120630

Patent document 4: japanese patent laid-open No. 2014-53410

Disclosure of Invention

Technical problem to be solved by the invention

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a metal film lamination film which has good adhesion to a metal layer even under high-temperature and high-humidity conditions, does not cause discoloration of the metal layer, can suppress precipitation of oligomers which are precipitated when heat treatment is performed at a temperature of about 150 ℃ or 180 ℃ in a step of laminating the metal film and a heating step after patterning of the metal layer after lamination, can suppress deformation of the shape of the patterned metal layer and patterning of the metal film lamination film to be fine, can have a narrower pattern width, and can perform patterning without causing defects due to patterning defects even when used in a type of high-sensitivity wiring substrate designed to have high accuracy in response of the wiring substrate.

Means for solving the problems

The present inventors have conducted extensive studies in view of the above circumstances, and as a result, have found that the above-mentioned technical problems can be easily solved when a polyester film having a specific coating layer is used as a constituent member, and have completed the present invention.

That is, the gist of the present invention is a film for metal film lamination, characterized in that: at least one of the polyester film surfaces has a coating layer formed from a coating liquid containing a crosslinking agent in an amount of 70 wt% or more relative to nonvolatile components, and the coating layer satisfies the following formula (1).

|SMD-STD|≤0.4…(1)

(in the above formula, SMD represents the shrinkage (%) in the film Moving Direction (MD), STD represents the shrinkage (%) in the direction perpendicular to the film moving direction (TD), and the heating conditions were 150 ℃ for 90 minutes.)

In a preferred embodiment of the present invention, the polyester film is a multilayered polyester film comprising at least 3 layers and containing particles having an average particle diameter of 0.1 to 0.6 μm, and satisfies the following formulae (2) and (3).

0＜Ti≤20…(2)

0≤P≤300…(3)

(in the above formula, Ti represents the amount of titanium element (ppm) and P represents the amount of phosphorus element (ppm) in the multilayer polyester film.)

Effects of the invention

According to the film for metal film lamination of the present invention, even if the film is exposed to a high-temperature atmosphere of 150 ℃, 90 minutes, 180 ℃, 60 minutes, or the like for a long time and subjected to a severe heat treatment process, the haze of the film due to oligomer deposition is extremely little, the adhesion between the polyester film and the coating layer and the adhesion between the metal layer and the coating layer are good even under high-temperature and high-humidity conditions, the metal layer is not discolored, the patterning of the film for metal film lamination is fine, defects such as poor patterning do not occur even when the film is used in a type in which the pattern width is set to be narrower, and defects such as poor patterning do not occur even when the film is used in a type of a highly sensitive wiring board designed such that the response of the wiring board is highly accurate, and the film for metal film lamination is suitable as, for example, a flexible double-sided circuit board, Or a component for a touch panel (for example, a conductive film) is very valuable in industry.

Detailed Description

First, the polyester film will be explained. The polyester film of the present invention may have a single-layer structure or a multilayer structure, and may have a 2-layer or 3-layer structure, or may have 4 or more layers as long as the structure does not exceed the gist of the present invention, and is not particularly limited.

The polyester is obtained by polycondensation of an aromatic dibasic acid and an aliphatic diol. Examples of the aromatic dibasic acid include terephthalic acid and 2, 6-naphthalenedicarboxylic acid, and examples of the aliphatic diol include ethylene glycol, diethylene glycol and 1, 4-cyclohexanedimethanol. Examples of the representative polyester include polyethylene terephthalate (PET), polyethylene-2, 6-naphthalate (PEN), and the like.

The polyester may be a homopolyester or a copolyester. In the case of the copolyester, the copolyester is a copolymer containing 30 mol% or less of the third component. Examples of the dicarboxylic acid component of the copolyester include one or more of isophthalic acid, phthalic acid, terephthalic acid, 2, 6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and hydroxycarboxylic acids (e.g., p-hydroxybenzoic acid); examples of the diol component include one or more of ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1, 4-cyclohexanedimethanol, neopentyl glycol, and the like.

In the multilayer polyester film, in order to suppress precipitation of oligomers, it is preferable to use a titanium compound (Ti) and a phosphorus compound (P), and as for the content of the compounds, it is preferable to satisfy the following formulae (2) and (3) at the same time.

0＜Ti≤20…(2)

0≤P≤300…(3)

Ti is more preferably in the range of 2 to 10 ppm. When Ti exceeds the upper limit of the above formula (2), an oligomer is by-produced in the step of melt-extruding the polyester, and a film having a high transparency with less oligomer cannot be obtained. Furthermore, it is difficult to cope with optical applications and the like, particularly applications in which the color tone of the coating film is important.

On the other hand, P is more preferably in the range of 5 to 200ppm, particularly preferably 0 to 100 ppm. When P exceeds the upper limit of the above formula (3), gelation occurs during the production of the polyester, and foreign matter is formed, whereby the film quality is deteriorated, and it is difficult to cope with an inspection step involving optical evaluation, for example, for touch panel applications.

By satisfying the above formulae (2) and (3) at the same time, a more significant effect can be obtained in reducing the amount of the oligomer contained in the multilayer polyester film.

In addition, in the layer containing the titanium compound and the phosphorus compound, antimony element is preferably not substantially contained, and usually 10ppm or less, preferably 5ppm or less, and most preferably substantially not contained, that is, 1ppm or less. When the amount of antimony element is too large, the antimony element may be reduced by the phosphorus compound during melt extrusion, aggregated, and become a cause of foreign matter, or the film may be blackened and may have poor transparency

And (4) the process is complete.

The polyester constituting the layer containing the titanium compound and the phosphorus compound in the above-mentioned ranges may be a polyester obtained by melt polymerization, but is preferably used because it is made into a small piece after melt polymerization and the obtained polyester is solid-phase polymerized to obtain a raw material, and when the raw material is used, the amount of oligomers contained in the raw material is reduced.

The amount of the oligomer contained in the layer containing the titanium compound and the phosphorus compound in the above-mentioned range is usually 0.7% by weight or less, preferably 0.5% by weight or less. When the amount of the oligomer contained in the polyester layer is small, the effects of reducing the amount of the oligomer contained in the multilayer polyester film and preventing the oligomer from being precipitated on the film surface can be exhibited extremely high.

In the present invention, a film having a structure in which a polyester having a small oligomer content is coextruded and laminated on at least one surface of a layer made of a polyester having a normal oligomer content may be used, and when having such a structure, the effect of suppressing oligomer precipitation obtained in the present invention can be exhibited to a high degree.

The maximum roughness (St) of the film surface is preferably within a range of 10 to 100nm, more preferably 10 to 50nm, for each surface. When the maximum roughness (St) is less than 10nm, the film surface becomes excessively smooth, and there is a tendency that damage is frequently generated in the multilayer polyester film forming process. On the other hand, when the thickness exceeds 100nm, the frequency of occurrence of disconnection of the wiring tends to increase in the crystallization step of the transparent conductive layer, particularly in a very finely patterned portion having a wiring width of 4 μm or less. Further, when a laminate is produced by bonding a coating film with an adhesive, the haze of the laminate is greatly increased, and the laminate is sometimes unsuitable for use as an optical member from the viewpoint of optical characteristics and visibility.

In the present invention, it is preferable to blend particles having an average particle diameter of 0.1 to 0.6 μm in both outer layers of the multilayer structure mainly for the purpose of imparting slipperiness and preventing scratches in the respective steps.

The particles to be blended are preferably only 1 type, and are not particularly limited as long as they can impart slipperiness, and specific examples thereof include particles such as silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, alumina, and titanium oxide. Furthermore, heat-resistant organic particles described in Japanese patent publication No. 59-5216 and Japanese patent application laid-open No. 59-217755 can also be used. Examples of the other heat-resistant organic particles include a thermosetting urea resin, a thermosetting phenol resin, a thermosetting epoxy resin, and a benzoguanamine resin. In addition, precipitated particles formed by precipitating and finely dispersing a part of a metal compound such as a catalyst in a polyester production process may be used.

On the other hand, the shape of the particles to be used is not particularly limited, and any of spherical, massive, rod-like, flat, and the like can be used. Also, the hardness, specific gravity, color, and the like are not particularly limited.

The content of the particles in the outer layers is usually 0.05 to 1.0 wt%, preferably 0.05 to 0.5 wt%. When the content of the particles is less than 0.05 wt%, the slipperiness of the film may be insufficient, and as a result, appearance defects such as scratches may occur during film processing. On the other hand, when the amount exceeds 1.0% by weight, the film transparency may be insufficient.

In addition, in order to prevent damage or to impart slipperiness, alumina particles are preferably used in the polyester layer constituting the outermost layer of the multilayer polyester film. When the average particle diameter of the alumina particles is outside the above range, the scratch preventing effect and the slipperiness may be poor.

Specific examples of the alumina particles include γ -type and δ -type aluminas obtained by flame hydrolysis using anhydrous aluminum chloride as a raw material.

The method for adding the particles to the polyester is not particularly limited, and a conventionally known method can be used. For example, it may be added at any stage of the production of the polyester constituting each layer, and is preferably added after the completion of the esterification or transesterification reaction.

Further, the method may be performed by: a method of mixing a slurry of particles dispersed in ethylene glycol, water or the like with a polyester raw material using a kneading extruder with an air vent; or a method of mixing the dried pellets with the polyester raw material using a kneading extruder.

In addition to the above-mentioned particles, a conventionally known ultraviolet absorber, antioxidant, antistatic agent, heat stabilizer, lubricant, dye, pigment, and the like may be added to the polyester film as necessary.

The thickness of the polyester film is not particularly limited as long as it is within a range enabling film formation, and is usually 9 to 80 μm, preferably 12 to 75 μm.

The polyester film of the present invention is produced by the following method, but is not limited to the following method.

First, a method of using the above-described polyester raw material and cooling and solidifying the molten sheet extruded from the die by a cooling roll to obtain an unstretched sheet is preferable. In this case, in order to improve the planarity of the sheet, it is preferable to improve the adhesion between the sheet and the rotary cooling drum, and it is preferable to adopt an electrostatic application method and/or a liquid coating method.

Next, the obtained unstretched sheet is stretched in the biaxial direction. In this case, the unstretched sheet is first stretched in one direction by a roller or tenter type stretching machine. The stretching temperature is usually 70 to 120 ℃, preferably 80 to 110 ℃, and the stretching ratio is usually 2.5 to 7 times, preferably 3.0 to 6 times. Then, stretching is performed in a direction orthogonal to the stretching direction in the first stage, wherein the stretching temperature is usually 70 to 170 ℃ and the stretching ratio is usually 3.0 to 7 times, preferably 3.5 to 6 times. Then, the film is heat-treated at a temperature of 180 to 270 ℃ under tension or under 30% relaxation to obtain a biaxially oriented film.

In the above stretching, a method of performing unidirectional stretching in 2 or more stages may be employed. In this case, it is preferable to perform the final stretching ratios in both directions so as to be within the above ranges.

In addition, a simultaneous biaxial stretching method may be employed for the production of the polyester film. The simultaneous biaxial stretching method is a method of simultaneously stretching and orienting the above-mentioned unstretched sheet in the machine direction and the width direction while controlling the temperature of the sheet to be usually 70 to 120 ℃, preferably 80 to 110 ℃. The stretch ratio is usually 4 to 50 times, preferably 7 to 35 times, and more preferably 10 to 25 times in terms of area ratio. Then, the film is heat-treated at a temperature of 170 to 270 ℃ under tension or under 30% relaxation to obtain a stretch oriented film. As the simultaneous biaxial stretching apparatus using the stretching method, conventionally known stretching methods such as a screw method, a pantograph method, a linear drive method, and the like can be used.

Next, a coating layer on which the coating film is formed will be described. The coating layer can be formed by coating a coating liquid on the film, on-line coating in the film production process, or off-line coating in which the produced film is coated outside the system.

In order to reduce the increase in the amount of oligomer deposited from the outside to the coating layer due to thermal damage, the coating layer must be formed from a coating solution containing 70 wt% or more of a crosslinking agent with respect to nonvolatile components. The coating liquid may contain other components.

As the crosslinking agent, various known crosslinking agents can be used, and examples thereof include oxazoline compounds, melamine compounds, epoxy compounds, isocyanate compounds, carbodiimide compounds, silane coupling compounds, and the like. Among these, particularly in the case of use for providing a functional layer on a coating layer, an oxazoline compound is preferably used from the viewpoint of improving the durable adhesion. In addition, from the viewpoint of preventing deposition of the ester cyclic trimer onto the film surface due to heating, or improving the durability and coatability of the coating layer, a melamine compound is suitably used.

The oxazoline compound is a compound having an oxazoline group in a molecule, and particularly preferably an oxazoline group-containing polymer, and can be produced by homopolymerization of an addition polymerizable oxazoline group-containing monomer or polymerization with another monomer. Examples of the addition polymerizable oxazoline group-containing monomer include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline, and mixtures of 1 or 2 or more of these monomers can be used. Among them, 2-isopropenyl-2-oxazoline is preferable because it is industrially easily available. The other monomer is not limited as long as it is a monomer copolymerizable with the addition-polymerizable oxazoline group-containing monomer, and examples thereof include (meth) acrylates such as alkyl (meth) acrylates (alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 2-ethylhexyl, and cyclohexyl); unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, styrenesulfonic acid and salts thereof (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.); unsaturated nitriles such as acrylonitrile and methacrylonitrile; unsaturated amides such as (meth) acrylamide, N-alkyl (meth) acrylamide, and N, N-dialkyl (meth) acrylamide (as an alkyl group, methyl, ethyl, N-propyl, isopropyl, N-butyl, isobutyl, tert-butyl, 2-ethylhexyl, cyclohexyl, and the like); vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; α -olefins such as ethylene and propylene; halogen-containing α, β -unsaturated monomers such as vinyl chloride, vinylidene chloride, and vinyl fluoride; and α, β -unsaturated aromatic monomers such as styrene and α -methylstyrene, and 1 or 2 or more of these monomers can be used.

The oxazoline compound has an oxazoline group content of usually 0.5 to 10mmol/g, preferably 3 to 9mmol/g, and more preferably 5 to 8 mmol/g. When the amount is in the above range, the durability of the coating film is improved.

The melamine compound is a compound having a melamine structure among compounds, and for example, an alkylolated melamine derivative, a compound partially or completely etherified by reacting an alcohol with an alkylolated melamine derivative, and a mixture thereof can be used. As the alcohol used for the etherification, methanol, ethanol, isopropanol, n-butanol, isobutanol, and the like are suitably used. Further, as the melamine compound, either a monomer or a 2-or higher-polymer may be used, or a mixture of these may also be used. Further, urea or the like which is co-condensed with a part of melamine may be used, and a catalyst may be used in order to improve the reactivity of the melamine compound.

The epoxy compound is a compound having an epoxy group in the molecule, and examples thereof include a condensate of epichlorohydrin and a hydroxyl group or an amino group of ethylene glycol, polyethylene glycol, glycerin, polyglycerol, bisphenol a, etc., a polyepoxide compound, a diepoxy compound, a monoepoxy compound, a glycidylamine compound, and the like. Examples of the epoxy compound include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether; examples of the diepoxy compound include neopentyl glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, resorcinol diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether; examples of the monoepoxy compound include allyl glycidyl ether, 2-ethylhexyl glycidyl ether, and phenyl glycidyl ether; examples of the glycidyl amine compound include N, N' -tetraglycidyl-m-xylylenediamine, 1, 3-bis (N, N-diglycidylamino) cyclohexane, and the like.

The isocyanate-based compound is isocyanate or a compound having an isocyanate-derived structure represented by blocked isocyanate. Examples of isocyanates include: aromatic isocyanates such as toluene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate; aliphatic isocyanates having an aromatic ring such as α, α, α ', α' -tetramethylxylylene diisocyanate; aliphatic isocyanates such as methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, and hexamethylene diisocyanate; and alicyclic isocyanates such as cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), and isopropylidene dicyclohexyl diisocyanate. Further, there may be mentioned polymers and derivatives of these isocyanates such as biuretized compounds, isocyanurate compounds, uretdione compounds and carbodiimide-modified compounds. These may be used alone or in combination. Among the above isocyanates, aliphatic isocyanates and alicyclic isocyanates are more preferable than aromatic isocyanates in order to avoid yellowing due to ultraviolet rays.

When used in the state of blocking isocyanate, examples of the blocking agent include: phenol compounds such as bisulfite, phenol, cresol, and ethylphenol; alcohol compounds such as propylene glycol monomethyl ether, ethylene glycol, benzyl alcohol, methanol, and ethanol; active methylene compounds such as methyl isobutyrylacetate, dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, and acetylacetone; mercaptan compounds such as butyl mercaptan and dodecyl mercaptan; lactam-based compounds such as epsilon-caprolactam and delta-valerolactam; amine compounds such as diphenylaniline, aniline, and aziridine; amide compounds of acetanilide and acetamide; and oxime compounds such as formaldehyde, acetaldoxime, acetoxime, methylethylketoxime, and cyclohexanone oxime, and these blocking agents may be used alone or in combination of 2 or more.

The isocyanate compound may be used in the form of a monomer, or may be used in the form of a mixture or a combination with various polymers. In order to improve the dispersibility and the crosslinkability of the isocyanate-based compound, a mixture or a combination with a polyester resin or a polyurethane resin is preferably used.

The carbodiimide compound is a compound having a carbodiimide structure, and is a compound having one or more carbodiimide structures in a molecule, and more preferably a polycarbodiimide compound having 2 or more carbodiimide structures in a molecule for better adhesion and the like.

The carbodiimide compound can be synthesized by a conventionally known technique, and usually a condensation reaction of a diisocyanate compound is used. The diisocyanate compound is not particularly limited, and aromatic and aliphatic diisocyanates can be used, and specific examples thereof include tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and the like.

The content of the carbodiimide group in the carbodiimide compound is usually in the range of 100 to 1000, preferably 250 to 700, and more preferably 300 to 500 in terms of carbodiimide equivalent (weight [ g ] of the carbodiimide compound for providing 1mol of the carbodiimide group). When the amount is in the above range, the durability of the coating film is improved.

In addition, in order to improve the water solubility or water dispersibility of the polycarbodiimide compound, a surfactant may be added or a hydrophilic monomer such as a polyalkylene oxide, a quaternary ammonium salt of a dialkyl amino alcohol, or a hydroxyalkylsulfonate may be added to the polycarbodiimide compound, as long as the effects of the present invention are not lost.

These crosslinking agents may be used alone or in combination of 2 or more, but it was found that by combining 2 or more, adhesion to the functional layer and prevention of precipitation of the ester cyclic trimer after heating, which are difficult to be achieved at the same time, can be improved. Among them, an oxazoline compound capable of improving the adhesion to the functional layer and a melamine compound having good properties of preventing the precipitation of an alicyclic trimer after heating are particularly suitable and preferred.

It was also found that it is effective to combine 3 kinds of crosslinking agents in order to further improve the adhesion to the functional layer. The combination of 3 or more kinds of crosslinking agents is most suitably selected from melamine compounds as one of the crosslinking agents, and the combination with melamine compounds is particularly preferably an oxazoline compound and an epoxy compound, a carbodiimide compound and an epoxy compound.

Among these, these crosslinking agents are used for designing to improve the performance of the coating layer by reacting them in the drying process or film forming process. It is presumed that these unreacted crosslinking agents, reacted compounds, or mixtures thereof are present in the resulting coating layer.

When such a crosslinking component is contained, a component for promoting crosslinking, for example, a crosslinking catalyst may be used in combination.

In addition, when forming the coating layer, a polymer may be used in combination in order to improve coating appearance, adhesion when forming the functional layer on the coating layer, or the like.

Specific examples of the polymer include polyester resins, acrylic resins, polyurethane resins, polyethylene resins (such as polyvinyl alcohol), polyalkylene glycols, polyalkylene imines, methyl cellulose, hydroxy cellulose, and starches. Among them, polyester resins, acrylic resins, and urethane resins are preferably used from the viewpoint of improving adhesion to various surface functional layers. However, when the content is increased, the property of preventing the precipitation of the alicyclic trimer after heating may be deteriorated, and therefore, the content is usually 30% by weight or less, preferably 20% by weight or less, and more preferably 10% by weight or less. When the ratio is outside the above range, precipitation of the alicyclic trimer after heating may not be effectively suppressed.

In addition, when the coating layer is formed, particles may be used in combination for the purpose of improving adhesion and slidability. From the viewpoint of transparency of the film, the average particle diameter thereof is usually 1.0 μm or less, preferably 0.5 μm or less, and more preferably 0.2 μm or less. In order to improve the sliding property more effectively, the lower limit is usually 0.01 μm or more, preferably 0.03 μm or more, and more preferably more than the thickness of the coating layer. Specific examples of the particles include silica, alumina, kaolin, calcium carbonate, organic particles, and the like. Among them, silica is preferable from the viewpoint of transparency.

In addition, in the case of forming the coating layer, a defoaming agent, a coatability improving agent, a thickener, an organic lubricant, an antistatic agent, an ultraviolet absorber, an antioxidant, a foaming agent, a dye, a pigment, and the like may be used in combination as necessary within a range not to impair the gist of the present invention.

The proportion of the crosslinking agent is 70% by weight or more, preferably 80% by weight or more, and more preferably 90% by weight or more, relative to the total nonvolatile content of the coating liquid for forming the coating layer. When the ratio is less than the above range, precipitation of the ester cyclic trimer after heating may not be effectively suppressed.

In the case where melamine is selected as one of the crosslinking agents, the proportion of melamine is usually in the range of 5 to 95% by weight, preferably 15 to 80% by weight, and more preferably 30 to 65% by weight, based on the total nonvolatile components in the coating liquid forming the coating layer, from the viewpoint of preventing precipitation of the ester cyclic trimer after heating. When the ratio is less than the above range, precipitation of the ester cyclic trimer after heating may not be effectively suppressed. When the ratio is above the above range, the coating appearance may be deteriorated.

The thickness of the coating layer is usually in the range of 0.003 to 1 μm, preferably 0.005 to 0.5 μm, and more preferably 0.01 to 0.2 μm, in terms of the thickness of the coating layer on the finally obtained film. When the thickness is less than 0.003. mu.m, the amount of the ester cyclic trimer deposited from the film may not be sufficiently reduced. On the other hand, if the thickness is larger than 1 μm, problems such as deterioration in appearance of the coating layer and easy occurrence of blocking may occur.

As a method for applying the coating liquid to the polyester film, for example, a conventionally known coating method such as air knife coating, blade coating, bar coating, blade coating, extrusion coating, dip coating, reverse roll coating, transfer roll coating, gravure coating, contact roll coating, cast coating, spray coating, curtain coating, calender coating, extrusion coating, and the like can be used.

In order to improve the coating property and adhesion between the coating agent and the film, the film may be subjected to chemical treatment, corona discharge treatment, plasma treatment, or the like before coating.

The film for metal film lamination of the present invention may require high transparency even after being exposed to a high-temperature atmosphere for a long time when used for a touch panel or the like, for example. From such a viewpoint, the film haze change rate (heating haze,. DELTA.H) before and after the heat treatment (150 ℃ C., 90 minutes) is usually 0.5% or less, preferably 0.3% or less, and more preferably 0.1% or less, in order to be suitably used as a member for a touch panel. If Δ H exceeds 0.5%, visibility decreases as the haze of the film increases, and the film may not be suitable for applications requiring high visibility, such as touch panel applications. Further, the lower Δ H means that the precipitation of the oligomer is reduced.

In the film for metal film lamination of the present invention, the amount (OL) of the oligomer (cyclic trimer) extracted from the surface (one side) of the coating layer before and after the heat treatment (150 ℃ C., 90 minutes) with dimethylformamide is usually 1.5mg/m²Hereinafter, it is preferably 1.0mg/m²The following. In OL more than 1.5mg/m²In the case of the post-processing, for example, in a heat treatment step such as a sputtering step, the amount of oligomer deposited may increase and the transparency of the film may decrease with a long-term heat treatment in a high-temperature atmosphere, for example, at 150 ℃ for 90 minutes.

In the prior art, there is a problem that defects such as poor patterning occur in a type designed to make patterning of a metal layer film finer and having a narrower pattern width due to precipitation of oligomers precipitated when heat treatment is performed at a temperature of about 150 ℃ or 180 ℃ in a step of laminating a metal film. The inventors of the present invention considered that the maximum roughness (St) of the outermost surface of the multilayer polyester film substrate constituting the coating film is one of the causes of the patterning failure.

The maximum roughness (St) of the surface of the coating layer before and after the heat treatment of the coating film is usually 10 to 100nm, preferably 10 to 50 nm.

In the coating film of the present invention, it is necessary to consider corrosion caused by long-term contact between the coating layer and the metal layer in the film structure. From such a viewpoint, the material constituting the coating layer is preferably substantially composed of a material containing no halogen plasma substance in the use of the present invention. Specifically, the total amount of halogen ions detected after the coating film is left in pure water at room temperature for 24 hours is preferably 1ppm or less.

As a specific means for satisfying such a condition, for example, a means of avoiding as much as possible the use of an emulsion type material in which a surfactant is used in combination or an antistatic agent plasma material, a water-soluble crosslinking agent is preferably used as a main component (50% or more), more preferably 70% or more as a coating layer constituent material.

The film for metal film lamination of the present invention must satisfy formula (1). The absolute value of the difference (Delta S) in shrinkage upon heating at 150 ℃ for 90 minutes in the film Moving Direction (MD) and The Direction (TD) intersecting with the MD must satisfy the following formula (1).

|SMD-STD|≤0.4…(1)

(in the above formula, SMD represents the shrinkage rate (%) in the film moving direction, and STD represents the shrinkage rate (%) in the direction perpendicular to the film moving direction.)

That is, the absolute value of the difference (Δ S) in shrinkage when heating is performed at 150 ℃ for 90 minutes in the film Moving Direction (MD) and The Direction (TD) perpendicular thereto must be 0.4 or less.

The SMD is usually in the range of 0.1 to 1.5%, preferably 0.1 to 0.7%, and more preferably 0.1 to 0.3%.

The STD is usually in the range of-0.3 to 1.0%, preferably-0.1 to 0.4%, more preferably 0.1 to 0.3%.

When both the SMD and the STD are close to the range of 0.1-0.3%, the pattern width of the metal layer can be designed to be narrower.

Δ S is preferably 0.3 or less. More preferably 0.1 or less. When Δ S exceeds 0.4, the shape of the patterned metal layer is deformed, and the response of the wiring board tends to be lowered, and it is difficult to use the wiring board as a highly sensitive wiring board.

In the conventional technique, when a heat treatment is performed at a temperature of about 150 ℃ or 180 ℃ in a step of laminating a metal film using a coating film of a polyester film substrate, the coating film shrinks, and the shape of a patterned metal layer is deformed due to the difference between MD and TD shrinkage, and the response of a wiring board tends to be lowered. Therefore, a highly sensitive wiring board is required. The present inventors considered that the difference (Δ S) in the thermal shrinkage ratio between MD and TD of the coating film constituting the film for laminating a metal film is one of the causes of the problem.

In a coating film constituting a film for metal film lamination, it is possible to suppress a significant increase in haze caused by precipitation of oligomers from the coating film when used in a processing step under severe conditions such as a heat treatment at a temperature of about 150 ℃ or 180 ℃ or a durability test under a high-temperature and high-humidity atmosphere, suppress the maximum roughness (St) of the film surface before and after the heat treatment to a low level, and set the shrinkage difference (Δ S) between the MD and TD of the coating film to 0.4 or less, and it is possible to solve problems such as patterning failure even in the case of a wiring board type having high sensitivity in which patterning for a film for metal film lamination is designed to be fine, the pattern width is designed to be narrower. Here, MD of the coating film here indicates a film moving direction in the processing step. TD represents a direction perpendicular to the film moving direction in the processing step.

In the present invention, in order to further improve the above-mentioned effect of thermal dimensional stability, it is preferable to perform annealing treatment. As for the annealing treatment, a conventionally known method can be employed. Specifically, for example, the annealing temperature is usually 160 to 200 ℃, preferably 165 to 195 ℃, and more preferably 170 to 190 ℃. The annealing time is usually 1 to 30 seconds, preferably 3 to 20 seconds, and more preferably 5 to 15 seconds. The film moving speed is usually 10 to 300m/min, and the film tension (in the oven) is usually 1 to 10 kg/film width, preferably 1 to 7 kg/film width, more preferably 1 to 5 kg/film width, and the annealing treatment is preferably performed while the film is conveyed.

Next, a metal for forming a metal film laminated film will be described. As the metal, a simple metal substance such as gold, platinum, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, indium, or a solid solution (alloy) of 2 or more metals such as a nickel-chromium alloy can be used. Among them, in view of versatility of metal film formation, cost, ease of removal by etching, and the like, chromium, nickel, titanium, nickel-chromium alloy, aluminum, zinc, copper-nickel alloy, copper-titanium alloy, gold, silver, and copper are preferable, and chromium, nickel, titanium, nickel-chromium alloy, aluminum, zinc, gold, silver, and copper are more preferable. Most preferably copper (also including copper oxide). The metal film layer may be a single layer, or may have a multilayer structure in which 2 or more layers of different metals are stacked.

The thickness of the metal film formed on the coating layer surface of the coating film is not particularly limited, but is usually in the range of 5 to 500nm, preferably 10 to 300 nm. When the layer thickness of the metal layer is less than 5nm, the metal layer may be easily cracked. On the other hand, when the thickness of the metal layer exceeds 500nm, it takes a long time to form the metal layer, and the cost tends to be high.

As a method for forming the metal layer on the coating layer, a conventionally known method can be used. Specifically, the metal oxide film is preferably formed by 1 or more methods selected from a vapor deposition method, a sputtering method, and an ion plating method, and particularly preferably formed by a sputtering method. The above methods may be used in combination of 2 or more, or may be used singly.

In the vapor deposition method (vacuum vapor deposition method), it is preferable that a support (corresponding to a double-sided coating film in the present invention) is placed in a vacuum vessel, and a metal layer is formed on the coating layer by heating and evaporating the metal.

In the sputtering method, it is preferable that a support (corresponding to a double-sided coating film in the present invention) is placed in a vacuum vessel, an inert gas such as argon is introduced, a direct current voltage is applied, the ionized inert gas is made to collide with a target metal, and a metal layer is formed on the coating layer by the knocked-out metal.

In the ion plating method, it is preferable that a support (corresponding to a double-sided coating film in the present invention) is placed in a vacuum vessel, and a metal is heated and evaporated in a glow discharge atmosphere, so that a metal layer is formed on the coating layer by the ionized evaporated metal.

In the patterning, it may be performed by using a technique known in the art. For example, the disclosure is made in Japanese patent laid-open No. 2014-150118.

Examples

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples as long as the invention does not exceed the gist thereof. In the examples and comparative examples, "parts" means "parts by weight". The measurement method and the evaluation method used in the present invention are as follows.

(1) Method for measuring intrinsic viscosity of polyester:

1g of the polyester from which the other polymer components incompatible with the polyester and the pigment were removed was precisely weighed, and 100ml of a mixed solvent of phenol/tetrachloroethane (weight ratio) 50/50 was added to dissolve the polyester, and the measurement was performed at 30 ℃.

(2) Average particle diameter (d50) and particle size distribution:

the average particle diameter was determined by measuring the size of particles by a sedimentation method based on the Stokes' law of resistance using a centrifugal sedimentation type particle size distribution measuring apparatus SA-CP3 manufactured by Shimadzu corporation. The particle size distribution was determined in the same manner as the method for measuring the average particle size. That is, the particle size distribution ratio (R) was calculated from the following formula by integrating the particle sizes of the large particles in the equivalent spherical distribution.

(r) ═ particle diameter at 25% cumulative weight of particles/particle diameter at 75% cumulative weight of particles

(3) Method for determining the amount of oligomers contained in the polyester starting material:

about 200mg of the polyester raw material was weighed out and dissolved in 2ml of a mixed solvent of chloroform/HFIP (hexafluoro-2-isopropanol) in a ratio of 3: 2. After the dissolution, 20ml of chloroform was added thereto, and 10ml of methanol was added little by little. The precipitate was removed by filtration, and the precipitate was further washed with a mixed solvent of chloroform and methanol at a ratio of 2: 1, and the filtrate and the washing solution were recovered, concentrated by an evaporator, and then dried and solidified. The dried condensate was dissolved in 25ml of DMF (dimethylformamide), and the solvent solution was subjected to liquid chromatography (LC-7A, manufactured by Shimadzu corporation) to determine the amount of oligomer in DMF, which was divided by the amount of polyester starting material dissolved in the chloroform/HFIP mixed solvent to obtain the amount of oligomer contained (wt%). The amount of oligomers in DMF was determined from the peak area ratio of the peak area of the standard sample to the peak area of the measurement sample (absolute calibration curve method).

(4) Method for measuring the amount of oligomer contained in the coating film:

the coating film was weighed to about 200mg and dissolved in 2ml of a mixed solvent of chloroform/HFIP (hexafluoro-2-isopropanol) at a ratio of 3: 2. After the dissolution, 20ml of chloroform was added thereto, and 10ml of methanol was added little by little. The precipitate was removed by filtration, and the precipitate was further washed with a mixed solvent of chloroform and methanol at a ratio of 2: 1, and the filtrate and the washing solution were recovered, concentrated by an evaporator, and then dried and solidified. The dried cured product was dissolved in 25ml of DMF (dimethylformamide), and the solution was subjected to liquid chromatography (LC-7A, manufactured by Shimadzu corporation) to determine the amount of oligomer in DMF, which was divided by the amount of the coating film dissolved in the chloroform/HFIP mixed solvent to obtain the amount of oligomer contained (wt%). The amount of oligomers in DMF was determined from the peak area ratio of the peak area of the standard sample to the peak area of the measurement sample (absolute calibration curve method).

For the preparation of the standard sample, the oligomer (ester cyclic trimer) was accurately weighed in advance and dissolved in an accurately weighed amount of DMF to prepare the sample. The concentration of the standard sample is preferably in the range of 0.001 to 0.01 mg/ml.

The conditions of the liquid chromatography are as follows.

Mobile phase A: acetonitrile

Mobile phase B: 2% aqueous acetic acid solution

Column: "MCI GEL ODS 1 HU" manufactured by Mitsubishi chemical corporation "

Column temperature: 40 deg.C

Flow rate: 1 ml/min

Detection wavelength: 254nm

(5) Thickness of laminated polyester layer:

after the film of the small piece was fixed and molded with an epoxy resin, the film was cut with a microtome, and the cross section of the film was observed with a transmission electron microscope photograph. In this cross section, 2 interfaces formed by light and dark substantially parallel to the film surface were observed. The distance between the 2 interfaces and the film surface was measured from 10 photographs, and the average value was defined as the laminate thickness.

(6) Quantification of the amounts of metal elements and phosphorus elements in the polyester film:

the amount of elements in the film was determined by monolithic measurement using a fluorescence X-ray analyzer (model "XRF-1500" manufactured by Shimadzu corporation) under the conditions shown in Table 1 below by the FP method. The detection limit of the method is usually about 1 ppm.

[ Table 1]

(7) Thickness of the coating layer:

the membrane was fixed using embedding resin, the section was cut with a microtome, and 2% osmic acid was stained at 60 ℃ for 2 hours to prepare a sample. The obtained sample was observed with a transmission electron microscope (JEM 2010, Japan Electron Ltd.) to measure the thickness of the coating layer. The total 15 spots of the film were measured, and the average of 9 spots after removing 3 spots from the side with the larger value and 3 spots from the side with the smaller value was defined as the coating thickness.

(8) The method for measuring the amount of Oligomer (OL) extracted from the surface of the coating layer of the coating film constituting the film for laminating a metal film comprises:

the coated film was previously heated in air at 150 ℃ for 90 minutes. Then, the heat-treated film was formed into a box-like shape having an upper open longitudinal and transverse dimension of 10cm and a height of 3cm and having a measuring surface (coating layer) as an inner surface. Subsequently, 4ml of DMF (dimethylformamide) was added to the tank prepared in the above manner, and after leaving for 3 minutes, the DMF was recovered. The recovered DMF was subjected to liquid chromatography (LC-7A, manufactured by Shimadzu corporation), the amount of oligomer in the DMF was determined, and this value was divided by the area of the membrane in contact with the DMF to obtain a membrane tableAmount of flour oligomer (mg/m)²). The amount of oligomers in DMF was determined from the peak area ratio of the peak area of the standard sample to the peak area of the measurement sample (absolute calibration curve method) (plane A). The opposite surface side (B-side) was also measured by the same method as described above, and the amount of Oligomer (OL) extracted from the surface of the coating layer was determined.

For the preparation of the standard sample, the oligomer (cyclic trimer) was accurately weighed and previously separated and dissolved in an accurately weighed amount of DMF to prepare the sample. The concentration of the standard sample is preferably in the range of 0.001 to 0.01 mg/ml.

The conditions of the liquid chromatography are as follows.

Mobile phase A: acetonitrile

Mobile phase B: 2% aqueous acetic acid solution

Column: "MCI GEL ODS 1 HU" manufactured by Mitsubishi chemical corporation "

Column temperature: 40 deg.C

Flow rate: 1 ml/min

Detection wavelength: 254nm

(9) Measurement of coating film haze (H0):

for the sample film, the haze of the film was measured in accordance with JIS-K-7136 by using "HM-150" manufactured by color research institute in village.

(10) Measurement of haze (H1) of coated film after heat treatment:

the haze of the film was measured in the same manner as in (5) after the sample film was treated under the predetermined heat treatment conditions (150 ℃ C., 90 minutes).

(11) Measurement of haze Change amount (heating haze,. DELTA.H) of coating film:

the change in haze (heating haze,. DELTA.H) of the coated film was calculated from the measured values in the items (7) and (8).

ΔH＝(H1)-(H0)

The lower Δ H means that the less oligomer is precipitated by the high-temperature treatment, and the better the Δ H is.

(12) Maximum roughness (St) of the coating film surface (before heat treatment):

the surface roughness (St) of the measurement surface of the sample film was measured by a non-contact surface measurement system "Micromap 512 by Micromap corporation" using a direct phase detection interferometry, so-called 2-beam interferometry using michael interference. The measurement wavelength was set to 530nm, the objective lens was used at 20 times, the 20 ° field of view measurement was performed, the total of 12 points were measured, and the average of 10 points excluding the maximum value and the minimum value among the measured values was taken as the surface roughness (St). According to the above measurement method, the surface roughness (St1) (a-plane) of the film surface before the heat treatment is measured in the coating film. The surface roughness of the opposite surface (surface B) was also measured by the same method as described above (St 2).

(13) Maximum roughness (St) measurement of the coating film surface (after heat treatment):

in the same manner as in (12) above, the surface roughness (St3) (surface a) of the film surface after the heat treatment at 150 ℃ for 90 minutes was measured in the coating film.

The surface roughness of the opposite surface (surface B) was also measured by the same method as described above (St 4).

(14) Determination of the maximum roughness (St) of the surface of the patterned metal layer region:

in the coating film, a copper oxide layer having a thickness of 20nm was formed on the film surface by a reactive sputtering method. After a patterned (narrowest part: 20 μm) photoresist was applied on the copper oxide layer and dried and cured, the resulting copper oxide layer was immersed in a 4% aqueous solution of ferric chloride to be subjected to etching treatment. The obtained patterned copper oxide layer was crystallized by a heat treatment at 150 ℃ for 90 minutes. The surface roughness (St5) (surface a) of the metal layer region of the obtained patterned copper oxide layer was measured in the same manner as in (12) above.

(15) Determination of the maximum roughness (St) of the surface of the patterned metal layer region:

when a metal layer is present on the opposite side (side B) of (14), patterning is performed in the same manner as in (14) above, and the surface roughness of the metal layer region of the obtained patterned copper oxide layer is measured in the same manner as in (12) above (St 6).

(16) Maximum roughness (St) of the surface of the region where the patterned metal layer was not provided was measured:

the surface roughness (St) of the non-metallic layer region of (14) was measured by the same method as in (12) above (St7) (surface a).

(17) Maximum roughness (St) of the surface of the region where the patterned metal layer was not provided was measured:

the surface roughness (St) of the non-metallic layer region of (14) was measured by the same method as in (12) above (St8) (surface B).

(18) Measurement of shrinkage ratio (SMD, STD) of coating film:

the sample film was subjected to a heat treatment in an oven maintained at a predetermined temperature (150 ℃) for 90 minutes in a tension-free state, and the lengths of the samples before and after the heat treatment were measured and calculated by the following equation. Both MD and TD of the coating film were measured.

Shrinkage { (sample length before heat treatment) - (sample length after heat treatment) }/(sample length before heat treatment) × 100

(19) Evaluation of adhesion to metal layer (before heating and humidifying) (practical characteristic replacement evaluation):

in the coating film, a copper oxide layer having a thickness of 20nm was formed on the coating layer surface of the coating film by a reactive sputtering method. After a patterned photoresist was applied on the copper oxide layer and dried and cured, the resulting copper oxide layer was immersed in a 4% aqueous solution of ferric chloride to be subjected to etching treatment so that the copper oxide layer remained in a width of 3 mm. The obtained patterned copper oxide layer was crystallized by heat treatment at 150 ℃ for 90 minutes. Next, a tensile test was performed in the 90-degree direction according to JISC 5016 using "Ezgraph" manufactured by shimadzu corporation, and the adhesion force to the metal layer was measured and determined according to the following criteria (surface a). When a metal layer is present on the opposite surface side (B-surface), measurement is performed in the same manner as described above, and determination is performed according to the following determination criteria.

Reference for judgment

A: adhesion of 0.5N/mm or more, good adhesion (grade having no practical problem)

B: adhesion of 0.3 to 0.4N/mm, general adhesion (grade which may have problems in practical use)

C: adhesion force of 0.2N/mm or less, poor adhesion (grade having practical problems)

(20) Evaluation of adhesion to metal layer (after heating and humidifying) (practical characteristic replacement evaluation):

in the coating film, a copper oxide layer having a thickness of 20nm was formed on the coating layer surface of the coating film by a reactive sputtering method. After a patterned photoresist was applied on the copper oxide layer and dried and cured, the resulting copper oxide layer was immersed in a 4% aqueous solution of ferric chloride to be subjected to etching treatment so that the copper oxide layer remained in a width of 12 mm. The obtained patterned copper oxide layer was crystallized by heat treatment at 150 ℃ for 90 minutes. Thereafter, the mixture was placed in a constant temperature bath maintained at 85 ℃ and 85% RH humidity for 48 hours. Thereafter, the adhesion force to the metal layer was measured in the same manner as in (11) above, and the determination was performed according to the following criteria (surface a). When a metal layer is present on the opposite surface side (B-surface), measurement is performed in the same manner as described above, and determination is performed according to the following determination criteria.

Reference for judgment

(21) Evaluation of discoloration of metal layer (practical characteristic replacement evaluation):

in the coating film, a copper oxide layer having a thickness of 20nm was formed on the coating layer surface of the coating film by a reactive sputtering method. Thereafter, the substrate was placed in a constant temperature bath maintained at 85 ℃ and 85% RH humidity for 48 hours, and then the surface of the copper oxide layer on the surface of the film for metal film lamination was visually observed to perform the judgment (surface A) according to the following judgment standards. When a metal layer is present on the opposite surface side (B-surface), measurement is performed in the same manner as described above, and determination is performed according to the following determination criteria.

Reference for judgment

A: no discoloration, good (grade with no practical problems)

B: slight discoloration was observed (grade which may be problematic in practical use)

C: color change was confirmed (grade having practical problems)

(22) Evaluation of pattern shape (deformation) after copper layer patterning:

in the coating film, a copper oxide layer having a thickness of 20nm was formed on the coating layer surface of the coating film by a reactive sputtering method. A patterned photoresist (12 μm in diameter) was applied in a grid pattern on the copper oxide layer, and the resulting copper oxide layer was dried and cured, and then immersed in a 4% aqueous solution of ferric chloride to perform etching treatment. The obtained patterned copper oxide layer was observed with a measuring microscope for dimensional change (X, Y) of a lattice pattern (length of X before heating was 3.00mm and length of Y before heating was 3.00mm) before and after heat treatment at 150 ℃x90 minutes, and was judged according to the following criteria. The deformation of the shape of the patterned metal layer is caused by the shrinkage difference between MD and TD of the coating film. Therefore, in this evaluation, evaluation was performed on the a-plane for convenience.

(criteria for determination)

A: the difference in length between X and Y after heating is 0.01mm or less (a grade which shows little dimensional change before and after heating and has no practical problems)

B: the difference in length between X and Y after heating exceeded 0.01mm (a practically problematic grade due to dimensional change before and after heating treatment)

In this evaluation, the evaluation was performed in a lattice pattern, but the evaluation is not limited thereto.

(23) Evaluation of wiring disconnection after copper layer patterning (evaluation of practical characteristics of heat resistance replacement):

in the coating film, a copper oxide layer having a thickness of 20nm was formed on the film surface by a reactive sputtering method. A patterned photoresist (the most detailed portions: 4 μm, 8 μm, 12 μm, and 20 μm) was linearly coated on the copper oxide layer, and after drying and curing, the copper oxide layer obtained was immersed in a 4% aqueous solution of ferric chloride and subjected to etching treatment. The obtained patterned copper oxide layer was crystallized by heat treatment at 150 ℃ for 90 minutes.

The obtained patterned copper oxide layer was examined at 100 places at a magnification of 40 times with an optical microscope (model: VHX-200, manufactured by KEYENCE CORPORATION) for the area to be the most detailed part, and the presence or absence of the disconnection of the copper oxide layer was examined, and the disconnection of the patterned wiring (A-plane) was evaluated according to the following criteria. The opposite surface side (B-surface) was also examined in the same manner as described above, and was judged according to the following judgment criteria.

Reference for judgment

A: no disconnection of copper wiring was observed on both surfaces A and B

B: no disconnection of copper wiring was observed on both surfaces A and B, but cracking of the wiring was observed

C: quantification of the amount of halide ions in the copper wiring disconnection (24) coating film of 1 or more was confirmed on both surfaces a and B:

the sample film (coating film) was cut into a 10cm square and immersed in pure water at room temperature for 24 hours. Then, the amount of the detected halide ion was measured by ion chromatography under the following measurement conditions.

(conditions for ion chromatography measurement)

An analysis device: DX-320 manufactured by DIONEX corporation

Separating the column: ion Pac AS15(4mm X250 mm)

Protection of the column: ion Pac AG15(4mm X50 mm)

And (3) removing the system: ASRS-ULTRA (external demodulation mode, 100mA)

A detector: conductivity detector

Eluent: 7mM KOH (0 to 20 minutes)

45mM KOH (20 to 30 minutes)

(use of eluent generator EG40)

Eluent flow rate: 1.0 ml/min

Sample injection amount: 250 μ l

(criteria for determination)

A: the amount of the halogen ion is 1ppm or less (grade having no practical problem)

B: the amount of the halide ion exceeds 1ppm (which may cause problems in practice)

(25) And (3) comprehensive evaluation:

in the films for metal film lamination patterned on the coating layer surface of the coating film obtained in examples and comparative examples, comprehensive evaluation was performed according to the following criteria based on the adhesion to the metal layer (before and after heating and humidifying), evaluation of discoloration of the metal layer, pattern shape (deformation) after copper layer patterning, and evaluation of wiring disconnection after copper oxide layer patterning.

Reference for judgment

A: the adhesion to the metal layer (before and after heating and humidifying), the evaluation of the discoloration of the metal layer, the pattern shape (deformation) after patterning the copper layer, and the evaluation of the wiring breakage after patterning the copper oxide layer were all evaluated as ∘ (grade having no practical problems)

B: at least one of the adhesion to the metal layer (before and after heating and humidifying), the evaluation of discoloration of the metal layer, the pattern shape (deformation) after the copper layer patterning, and the evaluation of wiring disconnection after the copper oxide layer patterning was Δ (a level which may cause problems in practical use)

C: at least one of the adhesion to the metal layer (before and after heating and humidifying), the evaluation of the discoloration of the metal layer, the pattern shape (deformation) after the copper layer patterning, and the evaluation of the wiring disconnection after the copper oxide layer patterning was X (a practically problematic grade)

The polyesters used in examples and comparative examples were prepared by the following procedures.

Production of polyester

[ Process for producing polyester (I) ]

100 parts by weight of dimethyl terephthalate and 60 parts by weight of ethylene glycol were used as starting materials, tetrabutyl titanate as a catalyst was added, the mixture was placed in a reactor, the reaction starting temperature was set at 150 ℃, the reaction temperature was slowly increased while methanol was distilled off, and the temperature reached 230 ℃ after 3 hours. After 4 hours, the transesterification reaction was substantially completed. The reaction mixture was transferred to a polycondensation vessel and subjected to polycondensation reaction for 4 hours. That is, the temperature was slowly raised from 230 ℃ to 280 ℃. On the other hand, the pressure was gradually reduced from the normal pressure to 0.3 mmHg. After the reaction was started, the reaction was stopped at a time corresponding to an intrinsic viscosity of 0.55 by changing the stirring power of the reaction vessel, and the polymer was discharged under nitrogen pressure to obtain a polyester (I) having an intrinsic viscosity of 0.59 and an oligomer (cyclic trimer) content of 0.89% by weight.

[ Process for producing polyester (II) ]

Polyester (I) was previously crystallized at 160 ℃ and then subjected to solid-phase polymerization at 220 ℃ under a nitrogen atmosphere to obtain polyester (II) having an intrinsic viscosity of 0.72 and an oligomer (cyclic ester trimer) content of 0.46% by weight.

[ Process for producing polyester (III) ]

100 parts by weight of dimethyl terephthalate and 60 parts by weight of ethylene glycol were used as starting materials, magnesium acetate tetrahydrate as a catalyst was added, and the mixture was placed in a reactor, and the reaction starting temperature was set at 150 ℃. While methanol was distilled off, the reaction temperature was slowly increased to 230 ℃ after 3 hours. After 4 hours, the transesterification reaction was substantially completed. The reaction mixture was transferred to a polycondensation vessel, and after adding orthophosphoric acid, germanium dioxide was added to conduct polycondensation for 4 hours. That is, the temperature was slowly raised from 230 ℃ to 280 ℃. On the other hand, the pressure was gradually reduced from the normal pressure to 0.3 mmHg. After the reaction was started, the reaction was stopped at a time corresponding to an intrinsic viscosity of 0.63 by changing the stirring power of the reaction vessel, and the polymer was discharged under nitrogen pressure to obtain a polyester (III) having an intrinsic viscosity of 0.63.

[ Process for producing polyester (IV) ]

Polyester (IV) was obtained in the same manner as in the production method of polyester (I) except that alumina particles having an average particle diameter of 0.3 μm dispersed in ethylene glycol were added so that the content of the particles based on the polyester became 1.5 wt%. The resulting polyester (IV) had an intrinsic viscosity of 0.59 and an oligomer (ester cyclic trimer) content of 0.87% by weight.

[ Process for producing polyester (V) ]

The alumina particles were produced in the same manner as for the polyester (IV) except that the average particle diameter was changed to 0.04. mu.m, thereby obtaining a polyester (V). The resulting polyester (V) had an intrinsic viscosity of 0.59 and an oligomer (ester cyclic trimer) content of 0.87% by weight.

[ Process for producing polyester (VI) ]

The alumina particles were produced in the same manner as for the polyester (IV) except that the average particle diameter was changed to 0.8. mu.m, thereby obtaining a polyester (VI). The resulting polyester (VI) had an intrinsic viscosity of 0.59 and an oligomer (ester cyclic trimer) content of 0.87% by weight.

[ Process for producing polyester (VII) ]

100 parts by weight of dimethyl terephthalate and 60 parts by weight of ethylene glycol were used as starting materials, 0.09 part by weight of magnesium acetate tetrahydrate as a catalyst was placed in a reactor, the reaction starting temperature was set at 150 ℃, the reaction temperature was gradually increased while removing methanol by distillation, and the temperature reached 230 ℃ after 3 hours. After 4 hours, the transesterification reaction was substantially completed. To the reaction mixture, 0.04 part of ethyl acid phosphate was added, and then 0.04 part of antimony trioxide was added to conduct polycondensation reaction for 4 hours. That is, the temperature was slowly raised from 230 ℃ to 280 ℃. On the other hand, the pressure was gradually reduced from the normal pressure to 0.3 mmHg. After the reaction was started, the reaction was stopped at a time corresponding to an intrinsic viscosity of 0.63 by changing the stirring power of the reaction vessel, and the polymer was discharged under nitrogen pressure. The intrinsic viscosity of the resulting polyester (VII) was 0.63.

Example 1:

the polyester (II), (III) and (IV) were mixed at a ratio of 89.5%, 10% and 0.5% to obtain a mixture as a material for the layer a, and 100% of the polyester (I) was supplied as a material for the layer b to 2 extruders and melted at 285 ℃, respectively, and then the layer a was used as the outermost layer (surface layer) and the layer b was used as the intermediate layer. On a casting drum cooled to 40 ℃, 2 kinds of 3 layers (aba) were coextruded so that the thickness ratio of the laminated polyester film, a: b: a, was 2: 19: 2, and the resultant was cooled and solidified to obtain a non-oriented sheet. Then, the film was stretched 3.3 times in the longitudinal direction at a film temperature of 85 ℃ by using the difference in the peripheral speed of the rolls. Coating layers composed of the coating agents shown in the following table 2 were applied to both sides of the film (upper surface is a side a and lower surface is B side with respect to the film moving direction) in such an amount that the coating amount after drying reached 0.04 μm on one side, then introduced into a tenter, stretched 4.9 times at 120 ℃ in the transverse direction, heat-treated at 235 ℃, relaxed in the transverse direction, and wound up on a roll to obtain a double-sided coating film having a film width of 1000mm, a winding length of 6000m, and a coating layer having a thickness of 23 μm. Among them, compounds constituting the coating layer are exemplified below. Further, the fine adjustment of the STD is performed with the film width after the relaxation in the lateral direction.

(Compound examples)

(A1) The method comprises the following steps Hexamethoxymethylolmelamine

(A2) The method comprises the following steps EPOCROS (manufactured by JASCO Co., Ltd.) oxazoline compound having oxazoline group content of 7.7mmol/g

(A3) The method comprises the following steps EPOCROS (manufactured by JASCO Co., Ltd.) oxazoline compound having 4.5mmol/g oxazoline group content

(A4) The method comprises the following steps Polyglycerol polyglycidyl ether

(A5) The method comprises the following steps Blocked polyisocyanates synthesized as described below

1000 parts of hexamethylene diisocyanate was stirred at 60 ℃ and 0.1 part of tetramethylammonium octylate as a catalyst was added thereto. After 4 hours, 0.2 part of phosphoric acid was added to terminate the reaction, thereby obtaining an isocyanurate type polyisocyanate composition. 100 parts of the obtained isocyanurate type polyisocyanate composition, 42.3 parts of methoxypolyethylene glycol having a number average molecular weight of 400, and 29.5 parts of propylene glycol monomethyl ether acetate were added thereto, and the mixture was held at 80 ℃ for 7 hours. Thereafter, 35.8 parts of methyl isobutyrylacetate, 32.2 parts of diethyl malonate, and 0.88 part of a 28% methanol solution of sodium methoxide were added to the reaction mixture while maintaining the temperature of the reaction mixture at 60 ℃ for 4 hours. 58.9 parts of n-butanol was added, the reaction solution was kept at 80 ℃ for 2 hours, and then 0.86 part of 2-methylhexyl acid phosphate was added to obtain a blocked isocyanate.

(A6) The method comprises the following steps CARBODILITE (manufactured by Nisshinbo Chemical Inc.) carbodiimide equivalent 340 as a polycarbodiimide-based compound

(B1) The method comprises the following steps An aqueous acrylic resin dispersion having a glass transition temperature of 40 ℃ obtained by polymerization in the following composition

Emulsifying polymer of ethyl acrylate/N-butyl acrylate/methyl methacrylate/N-methylolacrylamide/acrylic acid 65/21/10/2/2 (wt%) (emulsifier: anionic surfactant)

(B2) The method comprises the following steps When a polyester polyol comprising 315 parts by weight of terephthalic acid, 299 parts by weight of isophthalic acid, 74 parts by weight of ethylene glycol and 265 parts by weight of diethylene glycol was used as (B2a), (B2a)953 parts by weight of polyester polyurethane comprising 267 parts by weight of isophorone diisocyanate, 56 parts by weight of ethylene glycol and 67 parts by weight of dimethylolpropionic acid was neutralized with ammonia to obtain a water dispersion (23% concentration, 30 mPas viscosity at 25 ℃ C.)

(B3) The method comprises the following steps Polyvinyl alcohol (degree of saponification 88 mol%, degree of polymerization 500)

(C1) The method comprises the following steps 2-amino-2-methylpropanoate hydrochloride as melamine crosslinking catalyst

(D1) The method comprises the following steps A quaternary ammonium salt group-containing polymer.

2-hydroxy-3-methacryloxypropyltrimethylammonium salt polymers

And (3) balancing ions: number average molecular weight of methanesulfonic acid group: 30000

(F1) The method comprises the following steps Silica particles having an average particle diameter of 0.07. mu.m.

(F2) The method comprises the following steps Alumina-modified silica particles having an average particle diameter of 0.02 μm.

Next, on the surface of the coating layer of the obtained coating film, a copper oxide layer was laminated on both sides by a sputtering method so that the thickness thereof became 20nm, a patterned photoresist was applied on the copper oxide layer, and after drying and curing, the obtained copper oxide layer was immersed in a 4% aqueous solution of ferric chloride and subjected to etching treatment, thereby obtaining a patterned film for laminating both-side metal films. The properties of the obtained film are shown in tables 10 to 16 below.

Examples 2 to 19:

a film was produced in the same manner as in example 1, except that the coating layer composed of the coating agent composition shown in table 2 below, the compounding of the raw materials (tables 3 to 9 below), the longitudinal stretching magnification, the lateral stretching magnification, the primary crystal temperature, the thickness composition ratio, the film thickness, and the film width after relaxation in the lateral direction were different in example 1, and a film was obtained. The properties of the obtained film are shown in tables 10 to 16 below.

Example 20:

a film was produced in the same manner as in example 6, except that the amount of the coating layer in example 6 was changed. The properties of the obtained film are shown in tables 10 to 16 below.

Example 21:

in example 1, a film was produced in the same manner as in example 1 except that the film produced was placed outside the system in a hot air oven, and the film was again heated (off-line annealing) at a film conveying speed of 60m/min and at 180 ℃ for 10 seconds under the condition that the film tension (in the oven) was set to 3kg/1000mm width. The properties of the obtained film are shown in tables 10 to 16 below.

Example 22:

in example 10, a film was produced in the same manner as in example 1 except that the film produced was placed outside the system in a hot air oven, and the film was again heated (off-line annealing) at a film conveying speed of 60m/min and at 190 ℃ for 10 seconds under the condition that the film tension (in the oven) was set to 3kg/1000mm width. The properties of the obtained film are shown in tables 10 to 16 below.

Example 23:

in example 11, a film was produced in the same manner as in example 11 except that the film produced was placed outside the system in a hot air oven, and the film was again heated (off-line annealing) at a film conveying speed of 60m/min and at 170 ℃ for 10 seconds under the condition that the film tension (in the oven) was set to 3kg/1000mm width. The properties of the obtained film are shown in tables 10 to 16 below.

Example 24:

in example 6, a film was produced in the same manner as in example 6 except that the film produced was placed outside the system in a hot air oven, and the film was again heated (off-line annealing) at a film conveying speed of 60m/min and at 160 ℃ for 10 seconds under the condition that the film tension (in the oven) was set to 3kg/1000mm width. The properties of the obtained film are shown in tables 10 to 16 below.

Example 25:

a film was produced in the same manner as in example 22 except that in example 22, a copper oxide layer was stacked only on the surface of the coating layer on the a-side of the coating film by a sputtering method so that the thickness thereof became 20nm, a patterned photoresist was coated on the copper oxide layer, the copper oxide layer was dried and cured, and the obtained copper oxide layer was immersed in a 4% aqueous solution of ferric chloride and subjected to etching treatment to obtain a patterned film for stacking a single-side metal film. The properties of the obtained film are shown in tables 10 to 16 below.

Comparative examples 1 to 7:

a film was produced in the same manner as in example 6, except that in example 6, the coating layer was changed to a coating layer having a composition of a coating agent shown in table 2 below. The properties of the obtained film are shown in tables 10 to 16 below.

In comparative examples 5, 6 and 7, in the evaluation of the discoloration of the metal layer (21), the discoloration of the surface of the copper oxide layer on the surface of the film for metal film lamination was also confirmed at 24 hours, which is an intermediate point of 48 hours after being placed in the thermostatic bath, and as a result, the discoloration was confirmed at 24 hours. The properties of the obtained film are shown in tables 10 to 16 below.

Comparative example 8:

a film was produced in the same manner as in example 1, except that the coating layer was not provided in example 1. The properties of the obtained film are shown in tables 10 to 16 below.

Comparative examples 9 to 11:

a film was produced in the same manner as in example 6, except that the material of the layer a was changed in example 6.

Comparative example 12:

in example 6, the surface of the double-sided coating film was roughened by changing the polyester (IV) of the surface layer to the polyester (VI) and producing the same as in example 1, and as a result, it was difficult to cope with patterning processing of the narrowest portion of 4 μm in the wiring disconnection evaluation after patterning the copper layer (23). The properties of the obtained film are shown in tables 10 to 16 below.

Comparative example 13:

a film was produced in the same manner as in example 6 except that the polyesters (III), (IV), and (VII) were mixed in proportions of 10%, 0.5%, and 89.5% as the raw materials for the layer a in the example. The properties of the obtained film are shown in tables 10 to 16 below.

Comparative example 14:

a film was produced in the same manner as in example 1, except that in example 1, the transverse stretching magnification and the width of the relaxed film in the transverse direction were different. The properties of the obtained film are shown in tables 10 to 16 below.

Comparative example 15:

a film was produced in the same manner as in example 18, except that in example 18, the transverse stretching magnification and the width of the film after relaxation in the transverse direction were different. The properties of the obtained film are shown in tables 10 to 16 below.

The coating agent compositions of the coating layers used in the examples and comparative examples are shown in table 2 below.

The polyester used in the examples and comparative examples was compounded with the raw materials for the surface layer and the intermediate layer as shown in tables 3 to 9 below.

The properties of the films obtained in the examples and comparative examples are shown in tables 10 to 16 below.

[ Table 2]

[ Table 3]

[ Table 4]

[ Table 5]

[ Table 6]

[ Table 7]

[ Table 8]

[ Table 9]

[ Table 10]

[ Table 11]

[ Table 12]

[ Table 13]

[ Table 14]

[ Table 15]

[ Table 16]

Claims

1. A film for metal film lamination, characterized in that:

at least one polyester film surface has a coating layer formed from a coating solution containing a crosslinking agent in an amount of 70 wt% or more relative to a nonvolatile component, and a metal layer is formed on the coating layer in an adhering manner,

the crosslinking agent contains a combination of 2 or more of oxazoline compounds and melamine compounds, or a combination of 3 or more of melamine compounds, carbodiimide compounds and epoxy compounds,

the maximum roughness (St) of the surface of the coating layer after the heat treatment is 10 to 100nm,

the polyester film is a multilayer polyester film having 3 layers and contains particles having an average particle diameter of 0.1 to 0.6 μm,

the polyester is a homopolyester or a copolyester,

the homopolyester is obtained by polycondensing an aromatic dicarboxylic acid and an aliphatic diol, wherein the aromatic dicarboxylic acid of the homopolyester is a dicarboxylic acid selected from terephthalic acid and 2, 6-naphthalenedicarboxylic acid, and the aliphatic diol is a diol selected from ethylene glycol and diethylene glycol;

the copolyester is a copolymer containing 30 mol% or less of a third component, and the dicarboxylic acid component of the copolyester is one or more selected from isophthalic acid, phthalic acid, terephthalic acid, 2, 6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and hydroxycarboxylic acid; the dihydric alcohol component is one or more than two selected from ethylene glycol, diethylene glycol, propylene glycol, butanediol, and neopentyl glycol,

the film for metal film lamination satisfies the following formulas (1) to (3),

in the formula (1) | SMD-STD | < 0.4 … (1), SMD represents a shrinkage rate in the film Moving Direction (MD) in units, STD represents a shrinkage rate in The Direction (TD) orthogonal to the film moving direction in units, heating conditions were 150 ℃ for 90 minutes,

0＜Ti≤20…(2)

0≤P≤300…(3)

in the above formulae (2) and (3), Ti represents the amount of titanium element in ppm and P represents the amount of phosphorus element in ppm in the multilayer polyester film.

2. The film for metal film lamination according to claim 1, wherein:

satisfies the following formula (4),

Sb≤10…(4)

in the above formula, Sb represents the amount of antimony element in the multilayer polyester and is expressed in ppm.

3. The film for metal film lamination according to claim 2, wherein:

as the particles, at least alumina particles are contained.

4. The film for metal film lamination according to claim 1, wherein:

the total amount of halide ions in the coating liquid is 1ppm or less.

5. The film for metal film lamination according to claim 4, wherein:

the coating liquid contains a surfactant or a hydrophilic monomer.

6. The film for metal film lamination according to claim 1, wherein:

the coating liquid contains particles having an average particle diameter of 1.0 [ mu ] m or less.

7. A metal film laminated film characterized by comprising:

a metal layer formed on the coating layer side of the film for metal film lamination according to any one of claims 1 to 6.

8. The metal film laminate film as claimed in claim 7, wherein:

the metal layer comprises copper.