WO2016111130A1 - Polymer blend composition, flexible metal laminate, and flexible printed wiring board - Google Patents

Abstract

The purpose of the present invention is to provide a polymer blend composition which is excellent in terms of adhesiveness, transparency, and dimensional stability. In particular, provided is a material capable of accommodating finer-pitch requests which will become severer in future in COF and other applications. The polymer blend composition is characterized by comprising two or more polyamide-imide resins and by satisfying the following requirements (1) and (2). (1) To include, as an essential component, a polyamide-imide resin (resin α) comprising general formula (1) and general formula (2) as constituent units, the molar ratio of general formula (1) to general formula (2) in the resin α, (general formula (1))/(general formula (2)), being 55/45 to 90/10 (2) To include, as an essential component, a polyamide-imide resin (resin β) which comprises general formula (3) as a constituent unit and which differs in makeup from the resin α.

Description

Polymer blend composition, flexible metal laminate and flexible printed circuit board

The present invention relates to a polymer blend composition, a film using the same, a flexible metal laminate, and a flexible printed board. More specifically, in addition to dimensional stability (low warpage, dimensional change), a polymer blend composition suitable for use in the fields of electrical and electronic equipment that has both adhesiveness and transparency, a film using the same, and a flexible metal laminate And a flexible printed circuit board.

In the present invention, the “flexible metal laminate” is a laminate formed of a metal foil and a film layer (resin layer), and is a laminate useful for manufacturing a flexible printed circuit board, for example. In addition, the “flexible printed circuit board” can be manufactured by a conventionally known method such as a subtractive method using a flexible metal laminate, for example, and a conductor circuit may be partially or entirely covered by a coverlay film. And so-called flexible circuit boards (FPC), flat cables, tape automated bonding (TAB), chip-on-flexible board (COF) circuit boards, and the like, which are coated with screen printing ink or the like.

Polyimide resin is widely used as a resin film for electronic materials because of its excellent insulation reliability in addition to heat resistance and chemical resistance. However, since the polyimide resin is insoluble and infusible, it is necessary to form a film by subjecting the solvent-soluble polyimide precursor to high temperature treatment. As a result, the problem is that the film is colored, the transparency is lowered, and the workability is poor because the procedure is complicated. On the other hand, polyamideimide resin is excellent in solubility and heat-treated at a relatively low temperature to obtain a film having excellent transparency. Therefore, as an alternative material for polyimide resin, an electronic material, particularly a resin film for a flexible metal laminate for COF It is used as

In the case of a flexible metal laminate for COF, when a driver IC is mounted on a substrate, positioning is often performed by irradiating visible light with a wavelength of 400 to 800 nm from the resin film side and performing image recognition processing with a CCD camera or the like. In particular, the resin film is often made of a material having a double bond. In this case, since the resin film has a large absorption below 500 nm, the wavelength range of 600 to 700 nm is generally regarded as particularly important. For this reason, when the light transmittance of the resin film after etching of the flexible metal laminate is low or when the haze is high, the positional accuracy is lowered, and it becomes impossible to cope with the high density and fine pitch of the wiring pattern.

Due to the trend toward fine pitch in recent years, the bonding area between the wiring and the resin film is reduced, and therefore, higher bond strength (peel strength) between the resin film and the metal foil is required. In general, a resin film has a coefficient of linear expansion (CTE) larger than that of metal. However, if the difference in CTE is greatly different, the heat applied when used as an electronic material expands and contracts as a metal laminate, causing a dimensional change. As a result, the wires may come into contact with each other and cause a short circuit. In addition, when the dimensions change, it may be difficult to form the fine pattern circuit itself. Therefore, it is desirable that the CTE of the metal foil and the resin film is equally low. From the above, various attempts have been made to satisfy high transparency, high adhesive strength, and low CTE.

In Patent Document 1, there is a method for producing a metal laminate having a good balance of heat resistance, adhesion, and the like by applying a polyamide imide resin having a high glass transition temperature (Tg) and low CTE onto a copper foil and drying. Are listed. However, in patent document 1, since the copper foil with a large surface roughness was used, there existed a problem that the resin film surface after etching a copper foil became rough and visibility deteriorated by irregular reflection of light. Also, the patternability at a narrow pitch is inferior due to the rough surface roughness of the copper foil, and the copper foil with a high surface roughness shows a high value, but the adhesive strength and patternability can be satisfied at the same time. Not.

In Patent Document 2, a flexible metal laminate having a polyimide insulating layer composed of a plurality of layers on a copper foil by applying a polyimide precursor resin solution to a relatively mirror-finished copper foil having a low surface roughness, followed by drying and curing. Is described. However, this metal laminate has insufficient bare chip mountability and adhesion strength to copper foil with high glossiness and reflectivity, and is further dried and imidized at a high temperature after application of the polyimide precursor resin solution. Therefore, it is inferior in workability. Moreover, since it heat-processes at high temperature, copper foil itself recrystallizes and there exists a problem that it is not suitable for the use for which fine pitch patterning property is requested | required.

Patent Document 3 discloses a technique for improving adhesive strength by laminating two layers of polyamideimide resin on a relatively mirror-finished copper foil.

JP 2008-110612 A JP 2007-214555 A JP 2012-11388 A

However, Patent Document 3 has a problem that the process becomes complicated by laminating two layers, and the productivity is poor. Further, since the thickness increases, there is a problem that it is difficult to reduce the size.

In view of the above problems, an object of the present invention is to provide a polymer blend composition excellent in transparency, adhesiveness, and dimensional stability by blending two kinds of polyamideimide resins as specific components. Furthermore, it is providing the film containing the said polymer blend composition, a flexible metal laminated body, and a flexible printed circuit board.

As a result of various studies to solve this problem, it was found that this can be achieved by adopting the following forms.

That is, the present invention has the following configuration.

A polymer blend composition comprising a polyamideimide resin having two or more components and satisfying the following requirements (1) and (2).
(1) A polyamideimide resin (resin α) containing the following general formula (1) and general formula (2) as structural units is an essential component, and the molar ratio of general formula (1) and general formula (2) in resin α Is the general formula (1) / (2) = 55/45 to 90/10

(In general formula (1) and general formula (2), R ₁ , R ₂ and R ₃ may be the same or different, and each represents hydrogen, or an alkyl group or alkoxy group having 1 to 4 carbon atoms. Is shown.)
(2) A polyamideimide resin (resin β) having a composition different from that of the resin α containing the following general formula (3) as a structural unit is an essential component.

(In general formula (3), R ₄ and R ₅ may be the same or different and each represents hydrogen, or an alkyl group or alkoxy group having 1 to 4 carbon atoms.)

The composition ratio of resin α and resin β is preferably resin α / resin β = 20/80 to 50/50 weight ratio. Resin β contains trimellitic anhydride as an acid component, and 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride It is preferable that at least one kind selected from the group consisting of the above-mentioned products and o-tolidine as the amine component.

A film containing the polymer blend composition and a flexible metal laminate in which the film is laminated on at least one side of a metal foil.

The flexible metal laminate preferably has a metal foil Rz of 1.2 μm or less, a 60 ° gloss of 200 or more, and an adhesive strength between the metal foil and the film of 7.0 N / cm or more.

The flexible metal laminate preferably has a light transmittance at a wavelength of 600 nm of 55% or more, a haze of 20% or less, and a linear expansion coefficient in the film portion after the metal foil etching. The amount of film distortion at the glass transition temperature in the TMA method is preferably 200 μm or less.

A flexible printed board containing the flexible metal laminate.

The present invention can provide a polymer blend composition excellent in adhesiveness, transparency, and dimensional stability, and a film, a flexible metal laminate, and a flexible printed board containing the polymer blend composition. In particular, a material that can be adapted to fine pitch requirements that will be further developed in the future for COF applications and the like can be obtained.

Hereinafter, the present invention will be described in detail.

(Polymer blend composition)
The polymer blend composition of the present invention is a composition containing two or more components of polyamideimide resin and satisfying the requirements (1) and (2). Two or more components of the polyamideimide resin are preferably mixed uniformly. For example, the polyamideimide resin can be obtained by uniformly mixing two or more types of polyamideimide resin varnish dissolved in an organic solvent and removing the solvent.

Polyamideimide resin (α) having a diphenyl ether skeleton and a phenylene skeleton contributes to transparency and adhesiveness. Further, the polyamideimide resin (β) having a biphenyl skeleton, particularly an o-tolidine skeleton, contributes to dimensional stability (low CTE). In the present invention, a polymer blend composition excellent in transparency, adhesiveness and dimensional stability can be obtained by blending these polyamideimide resins.

Usually, a polymer blend composition containing two or more components of a resin is compatible with these composition ratios in all practical areas below the thermal decomposition temperature, and incompatible in all areas. There are incompatible systems and partially compatible systems that are compatible in a certain region. There are types of partially miscible systems that induce reactions such as nucleation type and spinodal decomposition type depending on the condition of the phase separation state. The uniform polymer blend composition in the present invention refers to a state in which there is no macro phase separation to the extent that scattering by visible light does not occur. When macro phase separation occurs, for example, in the case of a film, a significant decrease in transparency can be confirmed.

[Requirement (1): First component: Resin α]
The requirement (1) will be described. The requirement (1) includes a polyamide-imide resin (hereinafter also referred to as a resin α) containing the general formula (1) and the general formula (2) as structural units as an essential component. Preferably, it is a polyamide-imide resin containing the basic structure represented by the general formula (1) and the general formula (2) as a repeating unit.

In general formula (1) and general formula (2), R ₁ , R ₂ and R ₃ may be the same or different, and each represents hydrogen, an alkyl group having 1 to 4 carbon atoms or an alkoxy group. Show. The carbon number is preferably 1 or more and 3 or less, more preferably 2 or less. Particularly preferably, R ₁ , R ₂ and R ₃ are all hydrogen.

As the acid component constituting the resin α, trimellitic anhydride is essential. Examples of acid components other than trimellitic anhydride include pyromellitic anhydride, phthalic anhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic anhydride, or 3,3 ′, 4,4′- Biphenyltetracarboxylic acid anhydride is mentioned, These can be used alone or in combination of two or more. Of these, pyromellitic acid anhydride and phthalic acid anhydride are preferable.

In addition to the above, as the acid component, trimellitic acid, pyromellitic acid, phthalic acid, isophthalic acid, terephthalic acid, biphenyldicarboxylic acid, diphenyletherdicarboxylic acid, diphenylsulfonedicarboxylic acid, 3 as long as the object of the present invention is not impaired. , 3 ′, 4,4′-benzophenone tetracarboxylic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 4,4′-dicarboxydiphenyl ether tetracarboxylic acid, bisphenol bis (trimellitate), naphthalene-2 , 3,6,7-tetracarboxylic acid and the like, monoanhydrides, dianhydrides, and esterified products can be used alone or as a mixture of two or more.

As the amine component constituting the resin α, 4,4′-diaminodiphenyl ether, p-phenylenediamine, 2,4-diaminotoluene, or diisocyanate corresponding to these, or a mixture of two or more of them should be used. is required.

Similarly, in addition to the above, 3,4′-diaminodiphenyl ether, 4,4′-diamino-3,3′-dimethyldiphenylmethane, o-tolidine, m-phenylene as long as the object of the present invention is not impaired as an amine component. Diamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 3,4-diaminotoluene, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminobenzophenone, 3 , 3′-diaminobenzophenone, 2,6-tolylenediamine, 2,4-tolylenediamine, 4,4′-diaminodiphenyl sulfide, 3,3′-diaminodiphenyl sulfide, 4,4′-diaminodiphenylpropane, 3,3'-diaminodiphenylpropane, 3,3'-diaminodiphenylmethane 4,4'-diaminodiphenylmethane, p-xylenediamine, m-xylenediamine, 1,4'-naphthalenediamine, 1,5'-naphthalenediamine, 2,6'-naphthalenediamine, 2,7-naphthalenediamine, 2 , 2'-bis (4-aminophenyl) propane, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) Benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [ 4- (3-aminophenoxy) phenyl] propane, 4,4′-bis (4-aminophenoxy) biphenyl, 4,4 ′ Bis (3-aminophenoxy) biphenyl and the like, or may be used alone, such as a diisocyanate corresponding to being this, or in combination of two or more.

In the present invention, the resin α having the general formula (1) and the general formula (2) and the resin β having the general formula (3) are blended to maintain the dimensional stability (low CTE) of the film. We found that transparency can be improved. The reason for the improved adhesiveness is that the ether bond of the general formula (1) provides flexibility, and the anchor is that the polymer blend composition easily enters fine irregularities on the surface even with a relatively mirror-finished metal foil. It is conceivable that it contributes to the improvement of the effect and the affinity with the metal foil. Moreover, it is thought that the characteristic that the ether bond of General formula (1) is hard to carry out heat deterioration contributes to the improvement of transparency.

The molar ratio of the general formula (1) to the general formula (2) in the resin α is preferably general formula (1) / general formula (2) = 55/45 to 90/10. More preferably, it is 60/40 to 85/15, and particularly preferably 65/35 to 80/20. If the molar ratio of the general formula (1) is less than 55, the effect of improving the adhesion and transparency by the ether bond of the general formula (1) may not be sufficient. Further, when the molar ratio of the general formula (1) exceeds 90, the soft component easily absorbs stress caused by the thermal history during the manufacturing process, but the resin skeleton becomes too soft, so that when the film is made into a film, Warpage tends to occur.

The structural unit of the general formula (1) contained in the resin α is preferably 55 mol% or more, more preferably 60 mol% or more, further preferably 65 mol% or more, preferably 90 mol% or less, and preferably 85 mol% or less. More preferred is 80 mol% or less. The structural unit of the general formula (2) contained in the resin α is preferably 10 mol% or more, more preferably 15 mol% or more, further preferably 20 mol% or more, preferably 45 mol% or less, and 40 mol%. The following is more preferable, and 35 mol% or less is more preferable. By setting it as the said range, the improvement effect of adhesiveness and transparency and the curvature prevention effect at the time of making a film can be anticipated.

[Requirement (2): Second component: Resin β]
The requirement (2) will be described. The requirement (2) includes a polyamideimide resin (hereinafter, also referred to as a resin β) having a composition different from that of the resin α including the general formula (3) as a structural unit as an essential component. A polyamideimide resin containing the basic structure represented by the general formula (3) as a repeating unit is preferable.

In general formula (3), R ₄ and R ₅ may be the same or different and each represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group. The carbon number is preferably 1 or more and 3 or less, more preferably 2 or less. Particularly preferably, R ₄ and R ₅ both have 1 carbon.

The structural unit of the general formula (3) contained in the resin β is preferably 60 mol% or more, more preferably 65 mol% or more, and further preferably 70 mol% or more. The upper limit is not particularly limited, and may be 100 mol%. If it is less than 60 mol%, low CTE characteristics are not sufficiently exhibited, and use as an insulating material for electrical and electronic equipment such as flexible printed wiring boards tends to be difficult.

Trimellitic anhydride is essential as the acid component constituting the resin β. Acid components other than trimellitic anhydride include 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, or pyromellitic An acid anhydride is mentioned, These can be used individually or in combination of 2 or more types. Of these, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride are preferable.

Further, trimellitic acid, pyromellitic acid, phthalic acid, isophthalic acid, terephthalic acid, biphenyldicarboxylic acid, diphenyletherdicarboxylic acid, diphenylsulfonedicarboxylic acid, 3,3 ′, 4 are not limited as long as the object of the present invention is impaired. , 4′-benzophenone tetracarboxylic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 4,4′- dicarboxydiphenyl ether tetracarboxylic acid, bisphenol bis (trimellitate), naphthalene-2,3,6, Monoanhydrides such as 7-tetracarboxylic acid, dianhydrides, and esterified products can be used alone or as a mixture of two or more.

As an amine component constituting the resin β, o-tolidine, 4,4′-diaminobiphenyl, 2,2′-dimethylbiphenyl-4,4′-diamine, o-dianisidine, or a corresponding diisocyanate alone, Alternatively, a mixture of two or more kinds can be used.

Similarly, other than the above, 4,4′-diaminodiphenylsulfone, 3,3′-diaminodiphenylsulfone, 4,4′-diaminodiphenylmethane, 3,3 ′ may be used as an amine component within the range not impairing the object of the present invention. -Diaminodiphenylmethane, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'- Diaminobiphenyl, 3,3′-diethyl-4,4′-diaminobiphenyl, 2,2′-dimethyl-4,4′-diaminobiphenyl, 2,2′-diethyl-4,4′-diaminobiphenyl, 3, 3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-diethoxy-4,4'-diaminobiphenyl, 4,4 ' Diaminobenzophenone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, p-phenylenediamine, m-phenylenediamine, 3,3'-diaminobenzanilide, 4,4'-diamino Benzanilide, 2,6-tolylenediamine, 2,4-tolylenediamine, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 4,4'-diaminodiphenylpropane, 3,3 ' -Diaminodiphenylpropane, p-xylenediamine, m-xylenediamine, 1,4-naphthalenediamine, 1,5-naphthalenediamine, 2,6-naphthalenediamine, 2,7-naphthalenediamine, 2,2'-bis ( 4-aminophenyl) propane, 1,3-bis (3-aminophenoxy) benzene, , 3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, bis [4- (4- Aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] propane, 4,4′-bis (4-aminophenoxy) biphenyl, 4 , 4′-bis (3-aminophenoxy) biphenyl or the like, or diisocyanates corresponding to these, or a mixture of two or more thereof can be used.

Among the acid component and amine component, a particularly preferred combination is a polyamideimide resin mainly composed of repeating units selected from the following monomer components.

<Acid component>
Trimellitic anhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride.
<Amine component>
o-Tolidine, 2,4-tolylenediamine, or the corresponding diisocyanate.

Resin α and resin β used in the present invention can be synthesized (polymerized) by an ordinary method. For example, there are an isocyanate method, an acid chloride method, a low temperature solution polymerization method, a room temperature solution polymerization method, etc., but from the viewpoint of production cost, a particularly preferable production method is an isocyanate method in which a polymer varnish can be obtained by a decarboxylation reaction. .

Solvents used for polymerization include amides such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, 1,3-dimethyl-2-imidazolidinone Solvents, sulfur solvents such as dimethyl sulfoxide and sulfolane, ketone solvents such as cyclohexanone and methyl ethyl ketone, nitro solvents such as nitrobenzene and nitroethane, ether solvents such as diglyme and tetrahydrofuran, nitrile solvents such as acetonitrile and propionitrile And ester solvents such as γ-butyllactone and γ-valerolactone can be used alone or as a mixed solvent.

The composition ratio of resin α and resin β is preferably resin α / resin β = 20/80 to 50/50 (weight ratio). More preferably, it is 25/75 to 40/60 (weight ratio). If the resin α is too much (exceeds 50 (weight ratio)), the low CTE characteristic of the resin β is not sufficiently exhibited, and it becomes difficult to use it as an insulating material for electrical and electronic devices such as flexible printed wiring boards. Tend. Conversely, if the amount of the resin α is too small (less than 20 (weight ratio)), the properties of the resin α, particularly properties such as adhesive strength and transparency may not be exhibited.

In the polymer blend composition of the present invention, the content of the resin α is preferably 10 to 50% by weight, more preferably 15 to 50% by weight, and still more preferably 20 to 50% by weight based on the total weight of the polymer blend composition. %. When the content of the resin α exceeds 50% by weight, the CTE increases, and it tends to be difficult to use as an insulating material for electric and electronic devices such as flexible printed wiring boards. When the content of the resin α is less than 10% by weight, characteristics inherent to the polymer including the structure represented by the general formula (1), particularly characteristics such as adhesive strength and transparency, tend not to be maintained.

The polymer blend composition of the present invention was directly laminated on a metal foil having a 10-point average roughness (Rz) of 1.2 μm or less and a 60 ° gloss of 200 or more without using an adhesive, and IPC-FC241 ( According to IPC-TM-650, 2.4.9 (A)), the adhesive strength between the metal foil and the polymer blend composition layer (film layer) when a circuit pattern is formed by the subtractive method is 7.0 N / cm. It is preferable to have the above.

<Polyamideimide resin solution>
The molecular weight of the polyamideimide resin α and the resin β is a molecular weight corresponding to 0.1 to 2.8 dl / g in N-methyl-2-pyrrolidone (polymer concentration 0.5 g / dl) with a logarithmic viscosity at 30 ° C. And more preferably those having a molecular weight corresponding to 0.3 to 2.5 dl / g. If the logarithmic viscosity is less than 0.1 dl / g, mechanical properties may be insufficient when formed into a molded product such as a film, and if it exceeds 2.8 dl / g, the solution viscosity becomes high. May be difficult. As an appropriate solution viscosity, the vertical viscosity at 25 ° C. is in the range of 50 to 1000 dPa · s. When the viscosity is out of the above range, the coatability may be lowered.

The concentration of the polyamideimide resin α and the resin β solution (polymer blend composition solution) can be selected from a wide range, but is generally preferably about 5 to 40% by weight, more preferably about 8 to 30% by weight. preferable. When the concentration is out of the above range, drying efficiency is deteriorated, and it is feared that formation of a smooth surface becomes difficult and a necessary amount of heat increases. As a preferred solvent for the polyamideimide resin solution, N, N-dimethylformamide, 1,3-dimethyl-2-imidazolidinone, tetramethylurea, sulfolane, dimethylsulfone, and the like are used as dilution solvents after polymerization because of coating properties and the like. Oxides, γ-butyrolactone, cyclohexanone, cyclopentanone and the like are preferable, and N, N-dimethylacetamide and N-methyl-2-pyrrolidone are particularly preferable. Some of these can be replaced with hydrocarbon organic solvents such as toluene and xylene, ether organic solvents such as diglyme, triglyme and tetrahydrofuran, and ketone organic solvents such as methyl ethyl ketone and methyl isobutyl ketone. In addition, since these solvents can also be applied as solvents during polymerization, the polymerization solution can be applied as it is, so that a resin solution having excellent processability can be easily obtained.

If necessary, the polymer blend composition of the present invention may be added to the above-described polymer blend composition for the purpose of improving various properties of the flexible metal laminate or flexible printed circuit board, such as mechanical properties, electrical properties, slipperiness, and flame retardancy. Other resins, organic compounds, and inorganic compounds may be mixed or reacted to be used in combination. For example, lubricant (silica, talc, silicone, etc.), adhesion promoter, flame retardant (phosphorus, triazine, aluminum hydroxide, etc.), stabilizer (antioxidant, UV absorber, polymerization inhibitor, etc.), plating activity Agents, organic and inorganic fillers (talc, titanium oxide, silica, fluorine polymer fine particles, pigments, dyes, calcium carbide, etc.), silicone compounds, fluorine compounds, isocyanate compounds, blocked isocyanate compounds, acrylic resins, urethanes Resin, polyester resin, polyamide resin, epoxy resin, phenolic resin and organic compounds, or these curing agents, silicon oxide, titanium oxide, calcium carbonate, iron oxide and other inorganic compounds do not hinder the purpose of this invention Can be used together in a range. In addition, if necessary, a catalyst for polyimide formation such as aliphatic tertiary amine, aromatic tertiary amine, heterocyclic tertiary amine, aliphatic acid anhydride, aromatic acid anhydride, hydroxy compound, etc. It may be added. For example, triethylamine, triethylenediamine, dimethylaniline, pyridine, picoline, isoquinoline, imidazole, undecene, hydroxyacetophenone and the like are preferable, and pyridine compound, imidazole compound and undecene compound are particularly preferable. Among them, benzimidazole, triazole, 4 -Pyridinemethanol, 2-hydroxypyridine and diazabicyclo [5.4.0] undecene-7 are preferred, and 2-hydroxypyridine and diazabicyclo [5.4.0] undecene-7 are more preferred.

<Film>
The film of the present invention is a film containing a polymer blend composition, and can be produced using the polymer blend composition solution (varnish). Applying the polymer blend composition solution (varnish) on a support such as a metal foil, endless belt, drum, carrier film, etc., drying the coating, and optionally heat-treating the film after peeling off the support. It is formed by.

(Coating)
As a method of applying the polymer blend composition to a support such as a metal foil, a conventionally known method can be applied, for example, roll coater, knife coater, doctor, blade coater, gravure coater, die coater, reverse coater. It can apply | coat by etc.

(Dry)
The drying conditions after casting the polymer blend composition solution are not particularly limited, but in general, the polymer blend composition solution was initially dried at a temperature 70 to 130 ° C. lower than the boiling point (Tb (° C.)) of the solvent used in the polymer blend composition solution. Thereafter, secondary drying (heat treatment) is preferably performed at a temperature near or above the boiling point of the solvent. When the initial drying temperature is higher than (Tb-70) ° C., foaming occurs on the coated surface, and unevenness of the residual solvent in the thickness direction of the resin layer (polymer blend composition layer) increases, resulting in loose film. There is a case. In addition, warping (curl) may occur in the flexible metal laminate on which the film is laminated, and warping of the flexible printed circuit board obtained by processing the circuit may be increased.
On the other hand, when the drying temperature is lower than (Tb-130) ° C., the drying time becomes longer and the productivity may be lowered. The initial drying temperature varies depending on the type of solvent, but is generally about 60 to 150 ° C., preferably about 80 to 120 ° C. The time required for the initial drying is generally an effective time for the solvent remaining rate in the coating film to be about 5 to 40% by weight under the above temperature conditions, but generally about 1 to 30 minutes, Especially about 2 to 15 minutes.

The secondary drying (heat treatment) may be performed at a temperature near or above the boiling point of the solvent, but is generally 150 to 500 ° C., preferably 200 to 400 ° C. When the secondary drying temperature is low, the drying time becomes long and the productivity may decrease. If it is too high, the deterioration reaction proceeds depending on the resin composition, the resin film may become brittle, and the cost may increase. The time required for the secondary drying is generally an effective time for the solvent remaining amount in the coating film to be 1% by weight or less under the above-mentioned temperature conditions. is there.

In the present invention, initial drying and secondary drying may be performed under an inert gas atmosphere or under reduced pressure. Examples of the inert gas include nitrogen, carbon dioxide, helium, and argon, but it is preferable to use easily available nitrogen. When the reaction is performed under reduced pressure, the reaction is preferably performed under a pressure of about 10 ⁻⁵ to 10 ³ Pa, preferably about 10 ⁻¹ to 200 Pa.

In the present invention, both the initial drying and heat treatment methods are not particularly limited, but can be performed by a conventionally known method such as a roll support method or a floating method. Moreover, continuous heat treatment in a heating furnace such as a tenter type is also possible.

The film containing the polymer blend composition of the present invention thus obtained can obtain a tough film with mechanical properties, that is, high strength and high elongation, without impairing the low CTE property of the resin β.

Although the thickness of the film can be selected from a wide range, it is generally about 5 to 100 μm, preferably about 10 to 50 μm, after drying. When the thickness is less than 5 μm, the mechanical properties such as film strength and handling properties are inferior. On the other hand, when the thickness exceeds 100 μm, the properties such as flexibility and workability (drying property, coating property) are deteriorated. There are things to do.

In addition, surface treatment may be performed as necessary. For example, surface treatment such as hydrolysis, corona discharge, low temperature plasma, physical roughening, and easy adhesion coating treatment can be performed.

<Flexible metal laminate>
The flexible metal laminate of the present invention is preferably a two-layer metal laminate in which the film and the metal foil are directly laminated without using an adhesive. Examples of the production method include a laminating method and a casting method, and are not particularly limited. However, it is preferable to produce by a casting method that can be produced at low cost and processability.

The thickness of the metal foil is not particularly limited, but a metal foil of 1 to 50 μm, preferably 3 to 35 μm, more preferably 3 to 18 μm can be suitably used. When the thickness of the metal foil is less than 1 μm, the yield at the time of conveyance is lowered, and when it is thicker than 50 μm, the winding as a long object is poor and the winding property is deteriorated, and the yield may be lowered.

A metal foil having a 10-point average roughness Rz of 1.2 μm or less, preferably 1.0 μm or less, more preferably 0.8 μm or less can be suitably used. If Rz exceeds 1.2 μm, the unevenness of the copper foil is transferred to the resin film, the transparency of the resin film after etching is lowered, and sufficient positioning accuracy may not be ensured.

The glossiness of the metal foil is 200 or more, preferably 300 or more, more preferably 400 or more. The glossiness is measured according to JIS-Z8741-1997, and irradiated at an incident angle of 60 °, and the reflected light at 60 ° is measured. The higher the glossiness is, the lower the surface roughness is, and since there are less undulations reflected in the surface roughness, the surface becomes smoother. Therefore, a higher glossiness is better, but about 800 is sufficient.

The flexible metal laminate of the present invention is preferably formed by directly applying a solution of the polymer blend composition to a metal foil, drying the coating film, and optionally heat-treating it. As the metal foil, copper foil, aluminum foil, steel foil, nickel foil, etc. can be used, composite metal foil that combines these, zinc, chromium, nickel, cobalt, molybdenum compounds, or alloys thereof, Metal foils treated with other metals can also be used. A more preferable metal foil is a copper foil, but a commercially available electrolytic foil or a rolled foil can be used as it is if the above-mentioned characteristics are satisfied. For example, “SV”, “RCF” manufactured by Fukuda Metal Foil Powder Co., Ltd., “GHY” manufactured by Nikko Metal Co., Ltd., or “TQ-M4-VSP” manufactured by Mitsui Metal Mining Co., Ltd. Can be mentioned.

In the present invention, the amount of strain is the amount of change in the film caused by the release of internal stress when the flexible metal laminate is exposed to a temperature higher than the glass transition temperature, and the amount of strain is preferably 200 μm or less. If it exceeds 200 μm, the amount of change is large, the dimensional change of the flexible metal laminate is large, and the positional accuracy during mounting may be insufficient.

The flexible metal laminate of the present invention thus obtained has high mechanical properties of the insulating resin layer, that is, high strength, high strength, without impairing the high transparency, high adhesive strength of the resin α, and the low CTE of the resin β. It is possible to obtain a flexible metal laminate in which an elongation and tough film is laminated.

The adhesive strength between the metal foil and the film in the flexible metal laminate is preferably 7.0 N / cm or more, more preferably 7.5 N / cm or more, and still more preferably 8.0 N / cm or more. If it is less than 7.0 N / cm, the wiring may be peeled off from the substrate due to repeated shrinkage and expansion due to heat generated when used as an electronic component, making it difficult to cope with fine pitch. is there. Therefore, the higher the adhesive strength, the better, but 10.0 N / cm or more is sufficient.

In the present invention, the light transmittance is a characteristic related to the positioning accuracy when the driver is mounted, and the parallel light transmittance at 600 nm is defined as the light transmittance. The light transmittance in the film portion after etching the metal foil of the flexible metal laminate is preferably 60% or more, more preferably 65% or more, and still more preferably 70% or more. If it is less than 60%, the positioning accuracy at the time of mounting described above may be lowered, and it may be difficult to cope with fine pitch.

In the present invention, haze is also a characteristic related to positioning accuracy, similar to light transmittance. Haze is an index of turbidity, and the higher the haze, the lower the transparency of the object and the lower the transmittance. The haze in the film portion after etching the metal foil of the flexible metal laminate is preferably 20% or less, more preferably 15% or less, and still more preferably 13% or less.

The coefficient of linear expansion (CTE) in the film portion after etching the metal foil of the flexible metal laminate is preferably 10 to 25 ppm / K, more preferably 12 to 25 ppm / K, and still more preferably 15 to 25 ppm / K. .

The flexible metal laminate of the present invention is excellent in transparency by specifying the surface characteristics of the copper foil. Furthermore, it is excellent in adhesive force by blending two kinds of polyamideimide resins whose resin composition is specified, and is excellent in dimensional stability and workability by specifying the blend ratio. Therefore, as an electronic material, it can be suitably used not only for FPC, flat cable, and TAB applications but also for COF film carrier tapes that have high needs for miniaturization and high performance and fine wiring pitches.

Hereinafter, the present invention will be described in more detail by experimental examples. The present invention is not particularly limited by the experimental examples.

<Logarithmic viscosity>
Using the polyamideimide resin sample (resin α, resin β) obtained in the experimental example, it was dissolved in N-methyl-2-pyrrolidone so that the polymer concentration was 0.5 g / dl. The solution viscosity and solvent viscosity of the solution were measured at 30 ° C. with an Ubbelohde type viscosity tube, and calculated according to the following formula.
Logarithmic viscosity (dl / g) = [ln (V1 / V2)] / V3
In the above formula, V1 represents the solution viscosity measured with an Ubbelohde type viscosity tube, V2 represents the solvent viscosity measured with an Ubbelohde type viscosity tube, and V1 and V2 represent a polymer solution and a solvent (N-methyl-2-pyrrolidone). Was determined from the time taken to pass through the capillary of the viscosity tube. V3 is the polymer concentration (g / dl).

<Polymer concentration>
Using the polyamideimide resin sample (resin α, resin β) obtained in the experimental example, weighed the polymer resin solution to 0.20 g (W1), and dried in a hot air dryer at 240 ° C. for 1 hour. Thereafter, the weight was measured again (W2), and the polymer concentration was calculated from the amount of polymer that remained without volatilization.
Polymer concentration (% by weight) = (W2 / W1) × 100

<Etching>
The polyamideimide resin sample (resin α, resin β) obtained in the experimental example was applied to metal foil, dried, then immersed in 35% aqueous ferric chloride solution, and the metal foil was completely removed (etched). A single-layer etching film was obtained.

<Glass transition temperature and strain>
TMA (Thermo-mechanical analyzer / manufactured by Seiko Instruments Inc.) was measured under the following conditions by the tensile load method. The glass transition temperature was defined as the intersection of the base line before the endothermic peak and the tangent toward the endothermic peak in the endothermic curve at elevated temperature. The amount of strain was calculated from the inflection point of the baseline and the change length of the endothermic peak point. The sample used the film part after etching the metal foil of the flexible metal laminated body obtained by the experiment example.
Load: 5g
Sample size: 4 (width) x 20 (length) mm
Temperature increase rate: 10 ° C / min Atmosphere: Nitrogen

<Linear expansion coefficient (CTE)>
Using TMA (Thermomechanical Analyzer / Seiko Instruments Co., Ltd.), the tensile load method was used under the following conditions. The sample used the film part after etching the metal foil of the flexible metal laminated body obtained by the experiment example. CTE was calculated from the average value at 100 to 200 ° C. The lower the CTE, the higher the dimensional stability.
Load: 5g
Sample size: 4 (width) x 20 (length) mm
Temperature increase rate: 10 ° C / min Atmosphere: Nitrogen

<Glossiness>
The glossiness of the metal foil was in accordance with the specular glossiness measuring method described in JIS Z8741-1997, and the intensity of light reflected at a reflection angle of 60 ° was measured by irradiating a light source at an incident angle of 60 °. The incident angle here is 0 ° in the direction perpendicular to the light irradiation surface. Measurement was performed using a VG200 gloss meter manufactured by Nippon Denshoku Co., Ltd. The measurement measured the resin application surface of metal foil.

<Adhesive strength>
A circuit pattern was prepared by a subtractive method in accordance with IPC-FC241 (IPC-TM-650, 2.4.9 (A)) from the flexible metal foil laminate sample obtained in the experimental example, and the metal foil and film (polymer The adhesive strength with the blend composition layer) was measured.

<Light transmittance>
Using the film portion after etching the metal foil of the flexible metal foil laminate obtained in the experimental example, the measuring instrument was measured using a spectrophotometer V650 manufactured by JASCO Corporation. In order to measure the parallel light transmittance, an integrating sphere unit that receives diffused light was not used, and measurement was performed in a standard state.
The measurement range was 300 to 800 nm, and the value at 600 nm was read.

<Haze>
Using the film portion after etching the metal foil of the flexible metal foil laminate obtained in the experimental example, the measuring instrument was NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd., and the measurement was performed according to JIS-K7136. The scattered light transmittance divided by the total light transmittance was expressed as a percentage.

<Blend>
Resin α and / or resin β were charged so that the polymer concentration was as shown in Table 1. Dimethylacetamide was used as a diluent solvent, stirred for 2 hours in a 100 ° C. oil bath until uniform, and cooled to room temperature to obtain a polymer blend composition. When blending was not performed, the polymer concentrations shown in Table 1 were diluted with dimethylacetamide.

(Synthesis Example 1 (Resin α))
Trimellitic anhydride (86 mol%, 86.46 g), pyromellitic anhydride (7 mol%, 10.91 g), 4,4′-diisocyanate diphenyl ether (75 mol%, 93.64 g), 1,4-phenylene N-methyl-2-pyrrolidone (390.24 g) was added to diisocyanate (25 mol%, 19.82 g) and diazabicyclo [5.4.0] undecene-7 (0.76 g), and the polymer concentration was 30% by weight. A bull flask was charged. After reacting in an oil bath at 100 ° C. for 5 hours, phthalic anhydride (7 mol%, 7.41 g) was added, stirred for 1 hour, N-methyl-2-pyrrolidone (291.09 g) was added, and polymer was added. After diluting to a concentration of 20% by weight and cooling to room temperature, a polyamideimide resin (α-1) was obtained.

(Synthesis Example 2)
Trimellitic anhydride (100 mol%, 76.85 g), diphenylmethane diisocyanate (100 mol%, 99.10 g), diazabicyclo [5.4.0] undecene-7 (0.61 g) and N-methyl-2-pyrrolidone (564.38 g) was added and charged to a separable flask at a polymer concentration of 20% by weight. After reacting in an oil bath at 100 ° C. for 5 hours, N-methyl-2-pyrrolidone (235.16 g) was added, diluted to a polymer concentration of 15% by weight, and cooled to room temperature to obtain a polyamideimide resin.

(Synthesis Example 3 (Resin β))
Trimellitic anhydride (80 mol%, 41.50 g), 3,3 ', 4,4'-benzophenonetetracarboxylic acid (12.5 mol%, 10.88 g), 3,3', 4,4'- Biphenyltetracarboxylic acid (7.5 mol%, 5.96 g), o-tolidine diisocyanate (100 mol%, 71.36), diazabicyclo [5.4.0] undecene-7 (0.21 g) with N-methyl -2-Pyrrolidone (600.24 g) was added and charged to a separable flask at a polymer concentration of 15% by weight. After reacting in an oil bath at 100 ° C. for 5 hours, the mixture was cooled to room temperature to obtain a polyamideimide resin (β-1).

(Synthesis Example 4 (Resin β))
Using β-trimellitic anhydride (100 mol%), o-tolidine diisocyanate (80 mol%), and tolylene diisocyanate (20 mol%), the same procedure as in Synthesis Example 3 was carried out to obtain Resin β-2.

(Experimental Examples 1-6)
As shown in Tables 1 and 2, by using a polymer blend composition in which the blend ratio of the resin α was changed, electrolytic copper foil (trade name “CF-T9DA-SV”: manufactured by Fukuda Metal Foil Industry Co., Ltd .: Rz = 0.75 μm, glossiness = 500) using a knife coater and initial drying at 90 ° C. for 8 minutes. Subsequently, it dried until the solvent fully volatilized under vacuum, and the metal laminated body was obtained.
The increase in the blend ratio of the resin α confirmed that the adhesive strength was improved, and that the transmittance was improved and the haze was reduced. Therefore, the presence of the resin α is essential in the present invention. I understand. Also, as the blend ratio of the resin α increases, the linear expansion coefficient also increases. By increasing the blend ratio, the deviation of the linear expansion coefficient from copper increases, so control of the blend ratio is also important. I understand that.

(Experimental example 7)
As shown in Tables 1 and 2, a metal laminate was obtained under the same conditions as in Experimental Example 1 except that the resin composition of the resin α was changed.
By changing the composition of the resin α, the properties of the metal laminate were greatly deteriorated. From this, it can be seen that the composition of the resin α is important in the present invention.

(Experimental examples 8 and 9)
As shown in Tables 1 and 2, a metal laminate was obtained under the same conditions as in Experimental Example 1 except that the blend ratio of the resin α alone was changed.
It was confirmed that the resin α alone does not have a sufficient linear expansion coefficient. From this, it can be seen that the presence of the resin β is important in the present invention.

(Experimental Examples 10 to 13)
As shown in Tables 1 and 2, a metal laminate was obtained under the same conditions as in Experimental Example 1 except that the composition of resin β and the blend ratio were changed.
In the same manner as in Experimental Example 1, it was confirmed that the adhesive strength, light transmittance, and haze were improved by blending the resin α. This also shows that the presence of the resin α is important in the present invention.

(Experimental example 14)
As shown in Table 2, Experimental Example 1 except that the copper foil (trade name “CF-T4X-SV”: Fukuda Metal Foil Industry Co., Ltd .: Rz = 1.28 μm, glossiness = 90) was changed. A metal laminate was obtained under the same conditions.
Although the improvement of adhesive strength was confirmed by increasing the surface roughness Rz and decreasing the glossiness of the copper foil, it was confirmed that the transmittance and haze were greatly deteriorated. From this, it can be seen that the copper foil characteristics are important in the present invention.

Claims (11)

1. A polymer blend composition comprising a polyamideimide resin having two or more components and satisfying the following requirements (1) and (2).
   (1) A polyamideimide resin (resin α) containing the following general formula (1) and general formula (2) as structural units is an essential component, and the molar ratio of general formula (1) and general formula (2) in resin α Is general formula (1) / general formula (2) = 55/45 to 90/10
   

   

   
   

   

   
   (In general formula (1) and general formula (2), R ₁ , R ₂ and R ₃ may be the same or different, and each represents hydrogen, or an alkyl group or alkoxy group having 1 to 4 carbon atoms. Is shown.)
   (2) A polyamideimide resin (resin β) having a composition different from that of the resin α containing the following general formula (3) as a structural unit is an essential component.
   

   

   
   (In general formula (3), R ₄ and R ₅ may be the same or different and each represents hydrogen, or an alkyl group or alkoxy group having 1 to 4 carbon atoms.)
2. 2. The polymer blend composition according to claim 1, wherein the composition ratio of the resin α and the resin β is resin α / resin β = 20/80 to 50/50 weight ratio.
3. Resin β contains trimellitic anhydride as an acid component, and from 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride 3. The polymer blend composition according to claim 1, comprising at least one selected from the group consisting of o-tolidine as an amine component.
4. A film containing the polymer blend composition according to any one of claims 1 to 3.
5. A flexible metal laminate in which the film according to claim 4 is directly laminated on at least one side of a metal foil.
6. 6. A flexible metal laminate in which Rz of the metal foil according to claim 5 is 1.2 μm or less, 60 ° gloss is 200 or more, and the adhesive strength between the metal foil and the film is 7.0 N / cm or more.
7. The flexible metal laminate according to claim 5 or 6, wherein the film portion after etching the metal foil has a light transmittance of 55% or more at a wavelength of 600 nm.
8. The flexible metal laminate according to any one of claims 5 to 7, wherein the film portion after the metal foil etching has a haze of 20% or less.
9. The flexible metal laminate according to any one of claims 5 to 8, wherein the film portion after the metal foil etching has a linear expansion coefficient of 10 to 25 ppm / K.
10. The flexible metal laminate according to any one of claims 5 to 9, wherein in the film portion after etching the metal foil, the amount of film distortion at the glass transition temperature in the TMA method is 200 µm or less.
11. A flexible printed circuit board comprising the flexible metal laminate according to any one of claims 5 to 10.