JP2020055930A - Polyamic acid, polyimide, resin film, metal-clad laminate, and method of manufacturing the same - Google Patents

Abstract

To provide a polyimide film having high dimensional stability and high toughness, a metal-clad laminate, and a method of manufacturing the same.SOLUTION: A polyamic acid contains acid anhydride residues and diamine residues. The polyamic acid contains a PMDA residue derived from pyromellitic dianhydride (PMDA) within the range of 20-100 pts.mol based on 100 pts.mol of the total of the acid anhydride residues, and contains a diamine residue derived from a benzimidazole compound represented by formula (1) within the range of 10-90 pts.mol and a diamine residue derived from a diamine compound represented by formula (2) within the range of 10-90 pts.mol based on 100 pts.mol of the total of the diamine residues.SELECTED DRAWING: None

Description

  The present invention relates to a polyimide which can be suitably used as a member of an electronic component, an auxiliary material, and the like, and a use thereof.

  In recent years, metal-clad laminates composed of polyimide and its composition and metal foil have been used for flexible printed wiring boards (FPCs) used in various electronic devices, flexible solar cells, negative electrode materials for lithium-ion batteries, and suspensions for hard disk drives. LCD materials, organic EL display members, auxiliary materials, flexible electronic devices using printing technology or at least laminates used for the purpose of forming components thereof, etc., have been widely studied, and their use in various applications is expanding. ing.

  In addition, as electronic devices have become smaller, lighter, and more space-saving, metal-clad laminates have been required to be thinner and lighter in addition to the traditional requirements of heat resistance and adhesiveness, as well as fine patterns of metal foil. There has been a demand for improved processability, fine workability of polyimide, higher dimensional stability, mechanical strength, and the like.

  On the other hand, polyimide films are widely used in various fields because they have excellent properties such as heat resistance, cold resistance, chemical resistance, electrical insulation, and mechanical strength. Utilizing the properties of having particularly excellent heat resistance and high rigidity, it is widely used as a base film for manufacturing carrier tapes for FPC and tape automated bonding (TAB). In particular, since FPCs can be mounted three-dimensionally and at high density even in a limited space, they can be used, for example, for wiring of movable parts of electronic devices such as HDDs, DVDs, mobile phones, and smartphones, and for parts such as cables and connectors. Its applications are expanding.

  In the future, electronic devices are expected to be more sophisticated and smaller. Therefore, for example, in FPC, it is considered that the need to use the FPC in a multi-layered state increases. Further, in response to the reduction in thickness of housings of electronic devices such as mobile phones and smartphones, there is an increasing tendency to require thinner circuit boards themselves. However, as the insulating layer becomes thinner as the circuit board itself becomes thinner, the risk of occurrence of defects such as breakage during pattern processing increases. Therefore, it is required to improve the toughness of the polyimide as the insulating layer.

  Patent Document 1 proposes an ultrathin polyimide film having improved tear propagation resistance as polyimide. However, the polyimide film described in Patent Document 1 does not pay attention to the anisotropy of the linear expansion coefficient in the transport direction (MD direction) and the width direction (TD direction), and has a concern about dimensional accuracy.

  Further, a laminate for a wiring board in which a polyimide having a specific chemical structure is used for a polyimide layer has been proposed (for example, Patent Document 2). However, considering the future progress of thinning the insulating layer, there is room for further improvement in the toughness of the polyimide layer.

JP 2014-196467 A JP 2009-4720A

  An object of the present invention is to provide a polyimide film, a metal-clad laminate and a method for producing the same, which have high dimensional stability and high toughness.

  As a result of intensive studies, the present inventors have found that the above problem can be solved by using a polyimide having a specific structure, and have completed the present invention.

That is, the polyamic acid of the present invention is a polyamic acid containing an acid anhydride residue derived from an acid anhydride component and a diamine residue derived from a diamine component,
The acid anhydride residue contains a PMDA residue derived from pyromellitic dianhydride (PMDA) in a range of 20 to 100 mol parts based on a total of 100 mol parts of the acid anhydride residue. And
The diamine residue contains a diamine residue derived from the benzimidazole compound represented by the following formula (1) in a range of 10 to 90 parts by mol based on 100 mol parts of the diamine residue in total. In addition, it contains a diamine residue derived from a diamine compound represented by the following formula (2) in a range of 10 to 90 mol parts.

In the formulas (1) and (2), R is independently a halogen atom, an alkyl group or an alkoxy group which may be substituted with a halogen atom having 1 to 6 carbon atoms, or a monovalent carbon atom having 1 to 6 carbon atoms. A phenyl group or a phenoxy group which may be substituted with a hydrogen group or an alkoxy group, wherein Z ₁ is independently a divalent group containing a single bond, an aromatic ring or a heterocyclic ring, -O-, -S-, -CH _{2 -, - CH (CH 3} ) -, - C (CH 3) 2 -, - CO -, - COO -, - SO 2 -, - NH- or a divalent group selected from -NHCO-, Z ₂ is independently -O -, - S -, - CH 2 -, - CH (CH 3) -, - C (CH 3) 2 -, - CO -, - COO -, - SO 2 -, - NH - or a divalent group selected from -NHCO-, _{n 1} is an integer of from 0 to 3, _{n 2} is independently 0-4 Integer, _{n 3} is an integer of 0 to 2.

  In the polyamic acid of the present invention, the acid anhydride residue contains the PMDA residue in a range of 50 to 100 mol parts with respect to a total of 100 mol parts of the acid anhydride residue. Is also good. In this case, the diamine residue has a diamine residue derived from the benzimidazole compound represented by the formula (1) in a range of 50 to 90 mol parts based on a total of 100 mol parts of the diamine residue. And the diamine residue derived from the diamine compound represented by the formula (2) may be contained in the range of 10 to 50 mol parts, or the diamine residue may be A diamine residue derived from the benzimidazole compound represented by the formula (1) is contained in a range of 10 to 50 mol parts with respect to a total of 100 mol parts of the diamine residue, and the formula (2) )) May be contained in the range of 50 to 90 mol parts of a diamine residue derived from the diamine compound represented by the formula (1).

  The polyimide of the present invention is obtained by imidizing any of the above polyamic acids.

The resin film of the present invention is a resin film having a single layer or a plurality of polyimide layers,
The polyimide constituting at least one of the polyimide layers is made of any one of the above polyimides. Here, the total thickness of the polyimide layer made of the polyimide may be 50% or more of the entire thickness, or 5% or more and less than 50% of the total thickness. Is also good.

  Further, the resin film of the present invention may have a thickness in a range of 2 μm or more and 12 μm or less.

  The resin film of the present invention may have a coefficient of linear expansion (CTE) of 30 ppm / K or less.

  Further, the resin film of the present invention may have a tear propagation resistance of 2.5 kN / m or more.

The metal-clad laminate of the present invention is a metal-clad laminate including: an insulating resin layer including a single layer or a plurality of polyimide layers; and a metal layer laminated on at least one surface of the insulating resin layer. hand,
The polyimide constituting at least one of the polyimide layers is any one of the above-mentioned polyimides. Here, the total thickness of the polyimide layer made of the polyimide may be 50% or more of the entire thickness, or 5% or more and less than 50% of the total thickness. Is also good.

  In the metal-clad laminate of the present invention, the metal layer may contain at least one metal element of copper, iron or nickel.

A method for manufacturing a metal-clad laminate according to the present invention includes a metal-clad laminate including: an insulating resin layer including a single layer or a plurality of polyimide layers; and a metal layer stacked on at least one surface of the insulating resin layer. A method of manufacturing a body,
A step of laminating a resin layer of the polyamic acid on the metal layer and imidizing the polyamic acid to form a single layer or a plurality of polyimide layers.

  The polyimide of the present invention has high heat resistance and excellent dimensional stability, and has a high toughness of a polymer due to a rigid structure derived from a monomer, and is used, for example, in a process of manufacturing circuit board materials such as FPCs and electronic components. It is useful as a member to perform. By using the metal-clad laminate of the present invention, the reliability and yield of electronic components and electronic devices can be improved.

  Hereinafter, embodiments of the present invention will be described.

<Polyamic acid>
The polyamic acid of the present embodiment is a precursor of the polyimide of the present embodiment, and contains a specific acid anhydride residue and a specific diamine residue. In the present invention, the acid anhydride residue refers to a tetravalent group derived from tetracarboxylic dianhydride, and the diamine residue refers to a divalent group derived from a diamine compound. It represents that.

<Polyimide>
The polyimide of the present embodiment is obtained by imidizing the above-mentioned polyamic acid, and contains a specific acid anhydride residue and a specific diamine residue.

  Hereinafter, the acid anhydride residue and the diamine residue contained in the polyamic acid and the polyimide of the present embodiment will be described together.

(Acid anhydride residue)
The polyamic acid and the polyimide of the present embodiment contain, as an acid anhydride residue, a tetracarboxylic acid residue derived from pyromellitic dianhydride (PMDA) (hereinafter, also referred to as a “PMDA residue”). I do. Since the PMDA residue has a rigid skeleton, the in-plane orientation of molecules in the polyimide after imidization can be controlled as compared with other general acid anhydride components, and the thermal expansion coefficient (CTE) And the effect of improving the glass transition temperature (Tg).

  From such a viewpoint, the polyamic acid and the polyimide according to the present embodiment have the PMDA residue in an amount of 20 mol parts or more, preferably 50 mol parts or more, more preferably 100 mol parts of the acid anhydride residues in total. The content is controlled so as to be 70 mol parts or more, particularly preferably 80 mol parts or more. If the amount of PMDA residue is less than 20 mol, CTE may increase.

  Examples of the acid anhydride residue other than the PMDA residue contained in the polyamic acid and the polyimide according to the present embodiment include acid anhydride residues that are generally used as a raw material for polyimide. Specifically, for example, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA), 1,4-phenylenebis (trimellitic acid monoester) dianhydride (TAHQ), 3,6,7-naphthalenetetracarboxylic dianhydride (NTCDA), 3,3 ', 4,4'-diphenylsulfonetetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride, 2,3' , 3,4'-biphenyltetracarboxylic dianhydride, 2,2 ', 3,3'-, 2,3,3 ', 4'- or 3,3', 4,4'-benzophenonetetracarboxylic acid Dianhydride, 2,3 ′, 3,4′-diphenylethertetracarboxylic dianhydride, bis (2,3-dicarboxyphenyl) ether dianhydride, 3,3 ″, 4,4 ″-, 2,3,3 '', 4 ''-or 2,2 '', 3,3 ''-p-terphenyltetracarboxylic dianhydride, 2,2-bis (2,3- or 3,4 -Dicarboxy Enyl) -propane dianhydride, bis (2,3- or 3.4-dicarboxyphenyl) methane dianhydride, bis (2,3- or 3,4-dicarboxyphenyl) sulfone dianhydride, 1-bis (2,3- or 3,4-dicarboxyphenyl) ethane dianhydride, 1,2,7,8-, 1,2,6,7- or 1,2,9,10-phenanthrene- Tetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) tetrafluoropropane dianhydride, 2,3,5, 6-cyclohexane dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4,8-dimethyl-1,2,3 , 5,6,7-Hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 2,6- or 2,7-dichloronaphthalene-1,4,5,8-tet Lacarboxylic dianhydride, 2,3,6,7- (or 1,4,5,8-) tetrachloronaphthalene-1,4,5,8- (or 2,3,6,7-) tetracarboxylic Acid dianhydride, 2,3,8,9-, 3,4,9,10-, 4,5,10,11- or 5,6,11,12-perylene-tetracarboxylic dianhydride, cyclo Pentane-1,2,3,4-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride Aromatics such as thiophene-2,3,4,5-tetracarboxylic dianhydride, 4,4'-bis (2,3-dicarboxyphenoxy) diphenylmethane dianhydride, ethylene glycol bisanhydrotrimellitate Examples include tetracarboxylic acid residues derived from tetracarboxylic dianhydrides.

(Diamine residue)
The polyamic acid and the polyimide of the present embodiment are derived from a diamine residue derived from a benzimidazole compound represented by the general formula (1) and a diamine compound represented by the general formula (2) as a diamine residue. Containing diamine residues.

In the formulas (1) and (2), R is independently a halogen atom, an alkyl group or an alkoxy group which may be substituted with a halogen atom having 1 to 6 carbon atoms, or a monovalent carbon atom having 1 to 6 carbon atoms. A phenyl group or a phenoxy group which may be substituted with a hydrogen group or an alkoxy group, wherein Z ₁ is independently a divalent group containing a single bond, an aromatic ring or a heterocyclic ring, -O-, -S-, -CH _{2 -, - CH (CH 3} ) -, - C (CH 3) 2 -, - CO -, - COO -, - SO 2 -, - NH- or a divalent group selected from -NHCO-, Z ₂ is independently -O -, - S -, - CH 2 -, - CH (CH 3) -, - C (CH 3) 2 -, - CO -, - COO -, - SO 2 -, - NH - or a divalent group selected from -NHCO-, _{n 1} is an integer of from 0 to 3, _{n 2} is independently 0-4 Integer, _{n 3} is an integer of 0 to 2. Here, “independently” means that in the above formulas (1) and (2), a plurality of substituents R, divalent groups Z ₁ and Z ₂ , and an integer n ₂ may be the same or different. Means that you may. In the above formulas (1) and (2), the hydrogen atoms in the two terminal amino groups may be substituted, for example, -NR ₃ R ₄ (where R ₃ and R ₄ are independently Any substituent such as an alkyl group). The same applies to other diamine compounds.

  The benzimidazole compound represented by the general formula (1) (hereinafter sometimes referred to as “diamine (1)”) has a high planarity because of having a heterocyclic ring, so that the CTE is reduced and the gas is reduced. A polyimide having low permeability is obtained. In addition, it is considered that intermolecular hydrogen bonding derived from the imidazole moiety promotes toughness.

  From such a viewpoint, the polyamic acid and the polyimide according to the present embodiment include the diamine residue derived from the diamine (1) in a range of 10 to 90 mol parts with respect to a total of 100 mol parts of the diamine residue. The content is controlled so as to be preferably in the range of 20 to 80 mol parts, more preferably in the range of 25 to 75 mol parts. When the amount of the diamine residue derived from the diamine (1) is less than 10 parts by mole, CTE may increase, and it becomes difficult to form an intermolecular hydrogen bond derived from an imidazole moiety, and sufficient toughness can be achieved. Disappears. On the other hand, when the amount of the diamine residue derived from the diamine (1) exceeds 90 mol parts, the polarity derived from the imidazole moiety becomes high, and the moisture absorption of the polyimide tends to increase.

  The diamine (1) is preferably a diaminobenzimidazole compound represented by the following formula (3) or (4).

In the formula (3), R ₁ independently represents a single bond or a divalent group containing an aromatic ring.

In the formula (4), Ar ₂ represents a single bond or a divalent group containing an aromatic ring.

  Further, the diaminobenzimidazole compound represented by the formula (3) is more preferably a diamine represented by the general formula (5).

In the formula (5), Ar ₁ represents a single bond or a divalent group containing an aromatic ring. Here, the group Ar ₁ is preferably a divalent group including a phenyl group.

  Examples of the diamine (1) include 4-amino-2- (4-aminophenyl) benzimidazole, 5-amino-2- (4-aminophenyl) benzimidazole, and 6-amino-2- (4-aminophenyl) ) Benzimidazole, 7-amino-2- (4-aminophenyl) benzimidazole, 5-amino-2- (3-aminophenyl) benzimidazole, 4-amino-2- (3-aminophenyl) benzimidazole, 2 , 2'-p-phenylenebis (5-aminobenzimidazole), 2,2'-p-phenylenebis (6-aminobenzimidazole) and the like. Among these, 6-amino-2- (4-aminophenyl) benzimidazole and 5-amino-2- (4-aminophenyl) benzimidazole are particularly preferred.

Further, the diamine compound represented by the general formula (2) (hereinafter sometimes referred to as “diamine (2)”) is an aromatic diamine having two or more benzene rings. The diamine (2), by an amino group and a divalent linking group Z ₂ of which is directly connected to at least two benzene rings is, has a high flexibility with an increased degree of freedom with the polyimide molecular chain, It is considered that this contributes to the improvement of the flexibility of the polyimide molecular chain and promotes toughness. Examples of the linking group _{Z 2, -O -, - CH} 2 -, - C (CH 3) 2 -, - CO -, - SO 2 -, - S- are preferred. Further, it is considered that two or more benzene rings reduce the imide group concentration of the polyimide and promote low moisture absorption. Here, _{n 3} is 1-2 are preferable.

  From such a viewpoint, the polyamic acid and the polyimide according to the present embodiment have a diamine residue derived from the diamine (2) in a range of 10 to 90 mol parts with respect to a total of 100 mol parts of the diamine residue. The content is controlled so as to be preferably in the range of 20 to 80 mol parts, more preferably in the range of 25 to 75 mol parts. If the amount of the diamine residue derived from the diamine (2) is less than 10 parts by mole, the flexibility of the polyimide may be insufficient and the moisture absorption may increase. Further, when the amount of the diamine residue derived from the diamine (2) exceeds 90 mol parts, it is difficult to form an intermolecular hydrogen bond derived from the imidazole site of the diamine residue derived from the diamine (1), and the toughness is increased. Cannot be achieved sufficiently.

  The diamine (2) is preferably a diamine compound represented by the following formula (6).

In the formula (6), Z ₂ is independently -O-, -S-, -CH _2- , -CH (CH ₃ )-, -C (CH ₃ ) _2- , -CO-, -COO-,-. It represents a divalent group selected from SO ₂ —, —NH— and —NHCO—, and n ₃ represents an integer of 0 to 2.

  Examples of the diamine (2) include 3,3′-diaminodiphenylmethane, 3,3′-diaminodiphenylpropane, 3,3′-diaminodiphenylsulfide, 3,3′-diaminodiphenylsulfone, and 3,3-diaminodiphenylether 3,4'-diaminodiphenyl ether, 3,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylpropane, 3,4'-diaminodiphenylsulfide, 3,4'-diaminobenzophenone, (3,3'-bisamino ) Diphenylamine, 1,4-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene (TPE-R), 3- [4- (4-aminophenoxy) phenoxy] benzeneamine, 3- [3- (4-aminophenoxy) phenoxy] benzenamine, 1,3-bis (3-aminophenoxy) benzene APB) 4,4 '-[2-Methyl- (1,3-phenylene) bisoxy] bisaniline, 4,4'-[4-methyl- (1,3-phenylene) bisoxy] bisaniline, 4,4'- [5-Methyl- (1,3-phenylene) bisoxy] bisaniline, bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (3-aminophenoxy) phenyl] propane, bis [4- (3 -Aminophenoxy) phenyl] ether, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy)] benzophenone, bis [4,4 ′-(3-aminophenoxy)] benzanilide 4,4- [3- [4- (4-aminophenoxy) phenoxy] phenoxy] aniline, 4,4 ′-[oxybis (3,1-phenyleneoxy)] bisaniline, bis [4- (4-aminophenoxy) phenyl ] Ether (BAPE ), Bis [4- (4-aminophenoxy) phenyl] ketone (BAPK), bis [4- (3-aminophenoxy)] biphenyl, bis [4- (4-aminophenoxy)] biphenyl, 2,2-bis (4-aminophenoxyphenyl) propane (BAPP) and the like. Among them, 4,4′-diaminodiphenyl ether (4,4′-DAPE), 1,3-bis (4-aminophenoxy) benzene (TPE-R), 1,3-bis (3-aminophenoxy) benzene (APB) and 2,2-bis (4-aminophenoxyphenyl) propane (BAPP) are preferred.

  However, other diamines can be used in combination as long as the object of the present invention is not hindered. As the other diamine, those usually used as a raw material for polyimide can be used. For example, 2,2′-dimethyl-4,4′-diaminobiphenyl (m-TB), 2,2′-diethyl-4 , 4'-Diaminobiphenyl (m-EB), 2,2'-diethoxy-4,4'-diaminobiphenyl (m-EOB), 2,2'-dipropoxy-4,4'-diaminobiphenyl (m-POB) ), 2,2'-n-propyl-4,4'-diaminobiphenyl (m-NPB), 2,2'-divinyl-4,4'-diaminobiphenyl (VAB), 4,4'-diaminobiphenyl, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl (TFMB), p-phenylenediamine (p-PDA), m-phenylenediamine (m-PDA) and the like.

  In the polyamic acid and the polyimide of the present embodiment, the type of the acid anhydride and the diamine, and by selecting the respective molar ratio when using two or more acid anhydrides or diamines, toughness, thermal expansion , Adhesion, glass transition temperature (Tg), etc. can be controlled.

(Synthesis of polyimide)
The polyimide of the present embodiment can be produced by reacting the above-mentioned acid anhydride and diamine in a solvent to generate a precursor resin, and then heat-close the ring. For example, a polyimide precursor is obtained by dissolving an acid anhydride component and a diamine component in an organic solvent in approximately equimolar amounts and stirring at a temperature within a range of 0 to 100 ° C. for 30 minutes to 24 hours to cause a polymerization reaction. A polyamic acid is obtained. In the reaction, the reaction components are dissolved so that the generated precursor is in the range of 5 to 30% by weight, preferably 10 to 20% by weight in the organic solvent. Examples of the organic solvent used for the polymerization reaction include N, N-dimethylformamide, N, N-dimethylacetamide (DMAC), N-methyl-2-pyrrolidone, 2-butanone, dimethylsulfoxide, dimethyl sulfate, cyclohexanone, and dioxane. , Tetrahydrofuran, diglyme, triglyme and the like. Two or more of these solvents can be used in combination, and further, an aromatic hydrocarbon such as xylene or toluene can be used in combination. The amount of the organic solvent used is not particularly limited, but may be such that the concentration of the polyamic acid solution (polyimide precursor solution) obtained by the polymerization reaction is about 5 to 30% by weight. It is preferable to use it after adjusting.

  In the synthesis of polyimide, each of the above-mentioned acid anhydrides and diamines may be used alone or in combination of two or more. By selecting the types of the acid anhydride and the diamine and the respective molar ratios when using two or more acid anhydrides or diamines, it is possible to control the thermal expansion property, the adhesive property, the glass transition temperature, and the like. .

  Usually, the synthesized polyamic acid is advantageously used as a reaction solvent solution, but can be concentrated, diluted, or replaced with another organic solvent, if necessary. Polyamic acid is generally advantageously used because of its excellent solvent solubility. The method of imidizing the polyamic acid is not particularly limited. For example, a heat treatment in which the polyamide acid is heated in the solvent under a temperature condition in the range of 80 to 400 ° C. for 1 to 24 hours is suitably employed.

  The weight average molecular weight of the polyamic acid is, for example, preferably in the range of 10,000 to 400,000, and more preferably in the range of 50,000 to 350,000. If the weight average molecular weight is less than 10,000, the strength of the film tends to decrease and the film tends to become brittle. On the other hand, when the weight average molecular weight exceeds 400,000, the viscosity is excessively increased and defects such as unevenness in film thickness and streaks tend to occur during the coating operation.

<Resin film>
The resin film of the present embodiment has a single layer or a plurality of polyimide layers, and at least one polyimide layer is formed of the polyimide of the present embodiment and may be a film (sheet) made of an insulating resin. It may be a film of an insulating resin laminated on a substrate such as a resin sheet such as a copper foil, a glass plate, a polyimide film, a polyamide film, and a polyester film.

  Further, the thickness of the resin film of the present embodiment is preferably in the range of 2 to 12 μm, and more preferably in the range of 3 to 10 μm. If the thickness of the resin film is less than 2 μm, toughness cannot be ensured, so that problems such as breakage during processing are likely to occur. When the thickness of the resin film exceeds 12 μm, foaming frequently occurs in the manufacturing process, and defects in appearance are likely to occur.

  The resin film of the present embodiment has a single-layer polyimide layer composed of the polyimide of the present embodiment, or is a polyimide layer of a plurality of layers, the polyimide layer composed of the polyimide of the present embodiment Is 50% or more of the total thickness of the resin film, the polyimide of the present embodiment (hereinafter, also referred to as “main polyimide (A)”) may have an acid anhydride residue. The PMDA residue is preferably contained in the range of 50 to 100 parts by mol, more preferably in the range of 80 to 100 parts by mol, based on the total 100 parts by mol of the diamine residue. The diamine residue derived from the diamine (1), preferably in the range of 50 to 90 parts by mole, more preferably in the range of 60 to 90 parts by mole, and is derived from the diamine (2). Preferably the amine residue in the range of 10 to 50 molar parts, more preferably be contained in the range of 10 to 40 molar parts. By controlling in such a range, it is possible to improve the dimensional stability due to the low CTE of the resin film. Therefore, it is the most preferable embodiment to apply a polyimide layer composed of polyimide controlled in such a range to the main layer in the resin film, that is, the base film layer.

  Further, the resin film of the present embodiment is a multilayer polyimide layer, and the total thickness of the polyimide layer composed of the polyimide of the present embodiment is 5% or more of the total thickness of the resin film. %, The polyimide of the present embodiment (hereinafter, sometimes referred to as “sub-polyimide (B)”) has a PMDA residue based on a total of 100 mol parts of the acid anhydride residue. Is preferably in the range of 50 to 100 mol parts, more preferably in the range of 80 to 100 mol parts, and the diamine residue derived from the diamine (1) is added to the total of 100 mol parts of the diamine residue. Is contained in the range of preferably 10 to 50 parts by mole, more preferably 10 to 40 parts by mole, and the diamine residue derived from diamine (2) is preferably contained in the range of 50 to 90 parts by mole, Than Mashiku good to contain in the range of 60 to 90 molar parts. By controlling in such a range, dimensional stability and high toughness of the resin film are ensured, and it is preferable to apply the resin film as an adhesive layer to a base material such as a metal layer or another resin layer. Therefore, a resin film having a polyimide layer composed of polyimide controlled in such a range in the surface layer portion is the most preferred embodiment.

  The CTE of the resin film of the present embodiment is preferably 30 ppm / K or less, more preferably 25 ppm / K or less. By controlling to such a range, deformation such as curling can be suppressed, and high dimensional stability can be ensured. Here, CTE is the average value of the coefficient of thermal expansion of the resin film in the MD and TD directions.

  Further, the tear propagation resistance of the resin film of the present embodiment is preferably 2.5 kN / m or more, more preferably 3.0 kN / m or more, and most preferably 3.5 kN / m or more. By controlling in such a range, problems such as breakage during processing can be prevented.

  The method of forming the resin film of the present embodiment is not particularly limited. For example, [1] a method of producing a resin film by applying and drying a polyamic acid solution on a supporting substrate and then imidizing the same (hereinafter, referred to as “ Casting method), [2] a method of applying a polyamic acid solution to a support substrate, drying the resultant, peeling the polyamic acid gel film from the support substrate, and imidizing the gel film to produce a resin film. When the resin film manufactured in the present embodiment is composed of a plurality of polyimide layers, the manufacturing method may be, for example, [3] a method of applying and drying a polyamic acid solution to a supporting substrate. This is repeated a plurality of times, followed by imidization (hereinafter referred to as a sequential coating method). [4] A multilayer structure of polyamic acid is simultaneously applied to a supporting substrate by multilayer extrusion and dried, followed by imidization. (Hereinafter, multilayer extrusion method). The method for applying the polyimide solution (or the polyamic acid solution) on the base material is not particularly limited, and for example, it can be applied with a coater such as a comma, a die, a knife, and a lip. In forming a multilayer polyimide layer, it is preferable to repeat the operation of applying a polyimide solution (or polyamic acid solution) to a substrate and drying the substrate.

  The resin film of the present embodiment may contain an inorganic filler in the polyimide layer, if necessary. Specific examples include silicon dioxide, aluminum oxide, magnesium oxide, beryllium oxide, boron nitride, aluminum nitride, silicon nitride, aluminum fluoride, calcium fluoride, and the like. These can be used alone or in combination of two or more.

<Metal-clad laminate>
The metal-clad laminate of the present embodiment has an insulating resin layer including a single layer or a plurality of polyimide layers, and a metal layer laminated on at least one surface of the insulating resin layer. In this case, at least one of the polyimide layers may be formed using the polyimide of the present embodiment.

  In the metal-clad laminate of the present embodiment, for example, assuming that a polyimide layer formed of the polyimide of the present embodiment is P1, an arbitrary polyimide layer is P2, and metal layers are M1 and M2, When the main polyimide (A) is in the form (hereinafter sometimes referred to as “P1 (A)”), the following structures 1 to 8 are preferably exemplified. Preferably, in order to enhance the adhesion between the insulating resin layer and the metal layer, P2 in contact with at least one surface of the metal layer M1 or M2 has a glass transition temperature (Tg) of, for example, 360 ° C. or less, preferably 200 to 320 ° C. It is preferable that the adhesive layer is formed of a thermoplastic polyimide having a temperature in the range of ° C. Here, the total thickness of P1 is preferably 50% or more of the thickness of the insulating resin layer.

Configuration 1: M1 / P1 (A)
Configuration 2: M1 / P1 (A) / P2
Configuration 3: M1 / P1 (A) / P2 / M2
Configuration 4: M1 / P2 / P1 (A)
Configuration 5; M1 / P2 / P1 (A) / P2
Configuration 6; M1 / P2 / P1 (A) / P2 / M2
Configuration 7; M1 / P1 (A) / P2 / P1 (A)
Configuration 8; M1 / P1 (A) / P2 / P1 (A) / P2 / M2

In the metal-clad laminate of the present embodiment, for example, when P1 is made of the auxiliary polyimide (B) of the present embodiment (hereinafter, may be referred to as “P1 (B)”), preferably Configurations 9 to 15 are exemplified.Preferably, P2 has a thermal expansion coefficient (CTE) of 30 × 10 ⁻⁶ (1 / K) or less, for example, in order to increase the dimensional stability of the insulating resin layer. Is a low thermal expansion polyimide layer in the range of 10 × 10 ⁻⁶ to 30 × 10 ⁻⁶ (1 / K), and P2 may be applied to the base film layer, where the total thickness of P1 is It is preferable that the thickness be in the range of 5% or more and less than 50% with respect to the thickness of the insulating resin layer.

Configuration 9; M1 / P1 (B) / P2
Configuration 10; M1 / P1 (B) / P2 / P1 (B) / M2
Configuration 11; M1 / P1 (A) / P1 (B)
Configuration 12; M1 / P1 (A) / P1 (B) / M2
Configuration 13; M1 / P1 (B) / P1 (A)
Configuration 14; M1 / P1 (B) / P1 (A) / P1 (B)
Configuration 15; M1 / P1 (B) / P1 (A) / P1 (B) / M2

  In the metal-clad laminate of the present embodiment, the most preferred embodiment is the above-described configuration 1, configurations 11 to 15.

(Metal layer)
The material of the metal layer in the metal-clad laminate of the present embodiment is not particularly limited. For example, copper, stainless steel, iron, nickel, beryllium, aluminum, zinc, indium, silver, gold, tin, zirconium, and tantalum , Titanium, lead, magnesium, manganese, and alloys thereof. Among these, metal elements of copper, iron or nickel are preferable, and copper, copper alloy, stainless steel or Invar containing these metal elements is particularly preferable.

  The thickness of the metal layer is not particularly limited, but is preferably 100 μm or less, and more preferably 10 to 50 μm. From the viewpoints of production stability and handleability, the lower limit of the thickness of the metal layer is preferably 5 μm.

  The metal-clad laminate of the present embodiment is prepared, for example, by preparing a resin film containing the polyimide of the present embodiment, forming a seed layer by sputtering metal, and then forming the metal layer by plating, for example. It may be prepared by forming.

  Further, the metal-clad laminate of the present embodiment may be prepared by preparing a resin film including the polyimide of the present embodiment and laminating a metal foil thereon by a method such as thermocompression bonding. Good.

  In the metal-clad laminate of the present embodiment, the surface of the resin film may be subjected to a modification treatment such as a plasma treatment in order to enhance the adhesion between the resin film and the metal layer.

  Furthermore, the metal-clad laminate of the present embodiment is obtained by casting a coating solution containing the polyamic acid of the present embodiment on a metal layer, drying it to form a coating film, heat treating it, imidizing it, It may be prepared by a method of forming a layer (cast method). The polyamic acid-containing coating liquid of the present embodiment may be cast directly on the metal layer, or may be cast after forming another polyamic acid-containing coating film.

  In the casting method, since the polyamic acid resin layer is imidized in a state of being fixed to the metal foil, a change in expansion and contraction of the polyimide layer in the imidization process is suppressed, and the conveyance direction (MD direction) and the width direction (TD direction) are suppressed. Since the anisotropy of ()) can be reduced, this is a preferred embodiment. In order to effectively suppress foaming, the thickness of the insulating resin layer is preferably in the range of 2 to 12 μm, and more preferably in the range of 3 to 10 μm.

  A preferred embodiment of the metal-clad laminate of the present embodiment is a copper-clad laminate. The copper-clad laminate only needs to include a polyimide layer composed of a single layer or a plurality of layers and a copper foil on at least one surface of the polyimide layer. Further, in order to increase the adhesiveness between the polyimide layer and the copper foil, the layer in contact with the copper foil in the polyimide layer may be a thermoplastic polyimide layer. The copper foil can be provided on one side or both sides of the insulating layer. That is, the copper-clad laminate of the present embodiment may be a single-sided copper-clad laminate (single-sided CCL) or a double-sided copper-clad laminate (double-sided CCL). The copper-clad laminate of this embodiment can be used as an FPC, for example, by forming a copper wiring by processing a wiring circuit by etching a copper foil or the like.

  The metal-clad laminate of the present embodiment is useful mainly as a circuit board material such as an FPC or a member such as a mask used in a process of manufacturing an electronic component. That is, a patterned metal-clad laminate can be obtained by processing the metal layer of the metal-clad laminate of the present embodiment into a pattern by an ordinary method. This patterned metal-clad laminate is, for example, a circuit board represented by FPC, an active element such as a transistor or a diode, or an electronic circuit including a passive device such as a resistor, a capacitor or an inductor. Sensor elements for sensing light, humidity, etc., light-emitting elements, image display elements such as liquid crystal display, electrophoretic display, and self-luminous display, wireless and wired communication elements, arithmetic elements, storage elements, MEMS elements, solar cells, thin-film transistors, etc. It can be used as

  Examples will be shown below, and the features of the present invention will be described more specifically. However, the scope of the present invention is not limited to the examples. In the following examples, various measurements and evaluations are as follows unless otherwise specified.

[Measurement of viscosity]
The viscosity at 25 ° C. was measured using an E-type viscometer (trade name: DV-II + Pro, manufactured by Brookfield). The rotation speed was set so that the torque became 10% to 90%, and two minutes after the start of the measurement, the value when the viscosity was stabilized was read.

[Measurement of thermal expansion coefficient (CTE)]
The polyimide film (3 mm × 15 mm) was heated from room temperature to 260 ° C. at a rate of 20 ° C./min while applying a load of 5.0 g using a thermomechanical analyzer (TMA), and then heated at 5 ° C./min. The tensile test was performed under a temperature condition in which the temperature was decreased from 260 ° C. to 30 ° C. at a temperature decreasing rate. The coefficient of thermal expansion was measured from the amount of elongation of the polyimide film with respect to the temperature at the time of cooling.

[Measurement of tear propagation resistance]
A polyimide film (63.5 mm × 50 mm) was prepared, and a cut having a length of 12.7 mm was made in the polyimide film, and measurement was performed using a light load tearing tester (manufactured by Toyo Seiki Co., Ltd.).

[Workability evaluation]
The metal-clad laminate was subjected to pattern processing in which a part of the metal layer was etched by a roll-to-roll process, and workability evaluation for evaluating whether or not the polyimide film was torn was performed. The case where no break occurred in the polyimide film was evaluated as “OK”, and the case where break occurred occurred was evaluated as “impossible”.

The abbreviations used in this example indicate the following compounds.
APBIZ: 5-amino-2- (4-aminophenyl) benzimidazole TPE-R: 1,3-bis (4-aminophenoxy) benzene m-TB: 2,2'-dimethyl-4,4'-diaminobiphenyl DAPE: 4,4'-diaminodiphenyl ether APBOZ: 5-amino-2- (4-aminophenyl) benzoxazole MABA: 4,4'-diaminobenzanilide DABA: 2'-methoxy-4,4'-diaminobenzanilide PMDA: pyromellitic dianhydride BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride,
BTDA: benzophenone-3,4,3 ', 4'-tetracarboxylic dianhydride DMAc: N, N-dimethylacetamide

[Examples 1 to 3]
In order to synthesize the polyamic acids a to c, a solvent DMAc was added to a 500 ml separable flask so as to have a solid content concentration shown in Table 1 under a nitrogen stream, and a diamine component shown in Table 1 was added. The acid anhydride component was dissolved with stirring. Thereafter, the solution was continuously stirred at room temperature for 4 hours to carry out a polymerization reaction to prepare a yellow-brown viscous solution of polyamic acids ac.

(Synthesis Examples 1 to 10)
In order to synthesize the polyamic acids d to m, under a nitrogen stream, a solvent DMAc was added to a 500 ml separable flask so as to have a solid content concentration shown in Table 1, and a diamine component shown in Table 1 was added. The acid anhydride component was dissolved with stirring. Thereafter, the solution was continuously stirred at room temperature for 4 hours to carry out a polymerization reaction to prepare a viscous yellow-brown solution of polyamic acid d-m.

[Examples 4 to 10]
As shown in Table 3, a solution of polyamic acids a to c was applied to the glossy surface of copper foil 1 (electrolytic copper foil, thickness: 12 μm) using an applicator as shown in Table 3, and was applied at 50 to 130 ° C for 1 to 60. After drying for minutes, a stepwise heat treatment was further performed in a temperature range of 130 ° C. to 360 ° C. to form any of the polyimide layers a to c on the copper foil, thereby preparing metal-clad laminates 1 to 7.

  Using an aqueous ferric chloride solution, the copper foils of the metal-clad laminates 1 to 7 were removed by etching to prepare polyimide films 1 to 7. Table 3 shows the results of evaluating the tear propagation resistance, coefficient of thermal expansion (CTE), and workability of each polyimide film. Here, in Table 3, CTE (MD) indicates the CTE in the MD direction, and CTE (TD) indicates the CTE in the TD direction.

(Reference Examples 1 to 9)
As shown in Table 4, a solution of polyamic acid d-1 was applied to the glossy surface of the copper foil 1 using an applicator, and dried at 50-130 ° C. for 1-60 minutes. Stepwise heat treatment was performed in a temperature range of 360 ° C. to form one of the polyimide layers d to l on the copper foil, thereby preparing metal-clad laminates 8 to 16.

  Using an aqueous ferric chloride solution, the copper foils of the metal-clad laminates 8 to 16 were removed by etching to prepare polyimide films 8 to 16. Table 4 shows the results of evaluating the tear propagation resistance, coefficient of thermal expansion (CTE), and workability of each polyimide film. Here, in Table 4, CTE (MD) indicates the CTE in the MD direction, and CTE (TD) indicates the CTE in the TD direction.

[Example 11]
A solution of polyamic acid b was uniformly applied to the glossy surface of the copper foil 1 so that the thickness after heat treatment was about 2 μm, and dried at 50 to 130 ° C. for 1 to 60 minutes to remove the solvent. A solution of polyamic acid m was uniformly applied thereon so that the thickness after heat treatment was about 8 μm, and dried at 50 to 130 ° C. for 1 to 60 minutes to remove the solvent. Further, a solution of polyamic acid b was uniformly applied thereon so that the thickness after the heat treatment was about 2 μm, and dried at 50 to 130 ° C. for 1 to 60 minutes to remove the solvent. Thereafter, a stepwise heat treatment was performed from 130 ° C. to 360 ° C. to form an insulating resin layer 17 composed of a polyimide layer b / a polyimide layer m / a polyimide layer b on the copper foil, thereby preparing a metal-clad laminate 17.

  Using an aqueous ferric chloride solution, the copper foil of the metal-clad laminate 17 was removed by etching to prepare a polyimide film 17. Table 5 shows the results of evaluating the tear propagation resistance, coefficient of thermal expansion (CTE), and workability of the polyimide film 17. Here, in Table 5, CTE (MD) indicates the CTE in the MD direction, and CTE (TD) indicates the CTE in the TD direction.

[Examples 12 to 14]
Similarly to Example 11, in order to prepare metal-clad laminates 18 to 20, as shown in Table 5, by changing the type of polyamic acid and the thickness after heat treatment, forming insulating resin layers 18 to 20, Metal-clad laminates 18 to 21 were prepared.

  Using an aqueous ferric chloride solution, the copper foils of the metal-clad laminates 18 to 20 were removed by etching to prepare polyimide films 18 to 20. Table 5 shows the results of evaluating the tear propagation resistance, coefficient of thermal expansion (CTE), and workability of each polyimide film.

  From the results of Reference Examples 1 to 9, when the tear propagation resistance of the polyimide film was less than 2.5 kN / m, the toughness was insufficient. In particular, in the case of a polyimide film having a thickness of 12 μm or less, tearing was observed during processing. . On the other hand, it can be seen that the polyimide films of Examples 1 to 14 do not break during processing and can provide a metal-clad laminate suitable as an FPC material having a thin insulating layer.

The embodiments of the present invention have been described in detail for the purpose of illustration, but the present invention is not limited to the above embodiments.

Claims (16)

An acid anhydride residue derived from an acid anhydride component, and a diamine residue derived from a diamine component, comprising a polyamic acid,
The acid anhydride residue contains a PMDA residue derived from pyromellitic dianhydride (PMDA) in a range of 20 to 100 mol parts based on a total of 100 mol parts of the acid anhydride residue. And
The diamine residue contains a diamine residue derived from the benzimidazole compound represented by the following formula (1) in a range of 10 to 90 parts by mol based on 100 mol parts of the diamine residue in total. And a polyamic acid containing a diamine residue derived from a diamine compound represented by the following formula (2) in a range of 10 to 90 mol parts.

[In the formulas (1) and (2), R is independently a halogen atom, an alkyl group or an alkoxy group which may be substituted with a halogen atom having 1 to 6 carbon atoms, or a monovalent having 1 to 6 carbon atoms. A phenyl group or a phenoxy group which may be substituted with a hydrocarbon group or an alkoxy group, wherein Z ₁ is independently a divalent group containing a single bond, an aromatic ring or a heterocyclic ring, -O-, -S-,- A divalent group selected from CH ₂ —, —CH (CH ₃ ) —, —C (CH ₃ ) ₂ —, —CO—, —COO—, —SO ₂ —, —NH— or —NHCO— , -O _{Z 2} is independently _{-, - S -, - CH} 2 -, - CH (CH 3) -, - C (CH 3) 2 -, - CO -, - COO -, - SO 2 -, - NH- or a divalent group selected from -NHCO-, _{n 1} is an integer of 0 to 3, _{n 2} is 0 independently Integer, _{n 3} is an integer of 0 to 2. ] The acid anhydride residue contains the PMDA residue in a range of 50 to 100 mol parts based on a total of 100 mol parts of the acid anhydride residue,
The diamine residue contains a diamine residue derived from the benzimidazole compound represented by the formula (1) in a range of 50 to 90 mol parts based on a total of 100 mol parts of the diamine residue. The polyamic acid according to claim 1, further comprising a diamine residue derived from the diamine compound represented by the formula (2) in a range of 10 to 50 mol parts. The acid anhydride residue contains the PMDA residue in a range of 50 to 100 mol parts based on a total of 100 mol parts of the acid anhydride residue,
The diamine residue contains a diamine residue derived from the benzimidazole compound represented by the formula (1) in a range of 10 to 50 mol parts based on a total of 100 mol parts of the diamine residue. The polyamic acid according to claim 1, further comprising a diamine residue derived from the diamine compound represented by the formula (2) in a range of 50 to 90 mol parts.   A polyimide obtained by imidizing the polyamic acid according to claim 1.   A polyimide obtained by imidizing the polyamic acid according to claim 1. A resin film having a single layer or a plurality of polyimide layers,
A resin film comprising the polyimide according to claim 4, wherein the polyimide constituting at least one of the polyimide layers is a polyimide film. A resin film having a single layer or a plurality of polyimide layers,
The polyimide constituting at least one layer of the polyimide layer is made of the polyimide according to claim 4, and the total thickness of the polyimide layer made of the polyimide according to claim 4 is 50% or more with respect to the entire thickness. A resin film, characterized in that: A resin film having a single layer or a plurality of polyimide layers,
The polyimide constituting at least one layer of the polyimide layer is made of the polyimide according to claim 5, and the total thickness of the polyimide layer made of the polyimide according to claim 5 is 5% or more with respect to the entire thickness. A resin film having a content of less than 50%.   The resin film according to any one of claims 6 to 8, wherein the thickness is in a range of 2 µm or more and 12 µm or less.   The resin film according to any one of claims 6 to 9, wherein a coefficient of linear expansion (CTE) is 30 ppm / K or less.   The resin film according to any one of claims 6 to 10, wherein the tear propagation resistance is 2.5 kN / m or more. An insulating resin layer including a single layer or a plurality of polyimide layers, and a metal layer laminated on at least one surface of the insulating resin layer, a metal-clad laminate including:
A metal-clad laminate, wherein the polyimide constituting at least one of the polyimide layers comprises the polyimide according to claim 4 or 5. An insulating resin layer including a single layer or a plurality of polyimide layers, and a metal layer laminated on at least one surface of the insulating resin layer, a metal-clad laminate including:
The polyimide constituting at least one layer of the polyimide layer is made of the polyimide according to claim 4, and the total thickness of the polyimide layer made of the polyimide according to claim 4 is 50% or more with respect to the entire thickness. A metal-clad laminate, characterized in that: An insulating resin layer including a single layer or a plurality of polyimide layers, and a metal layer laminated on at least one surface of the insulating resin layer, a metal-clad laminate including:
The polyimide constituting at least one layer of the polyimide layer is made of the polyimide according to claim 5, and the total thickness of the polyimide layer made of the polyimide according to claim 5 is 5% or more with respect to the entire thickness. A metal-clad laminate characterized by being within a range of less than 50%.   The metal-clad laminate according to claim 12, wherein the metal layer contains at least one metal element of copper, iron, or nickel. An insulating resin layer including a single layer or a plurality of polyimide layers, and a metal layer laminated on at least one surface of the insulating resin layer, a method for manufacturing a metal-clad laminate including:
A step of laminating the polyamic acid resin layer according to claim 1 on the metal layer and imidizing the polyamic acid to form a single layer or a plurality of polyimide layers. Of producing a metal-clad laminate.