JP2023035477A - Thermoplastic polyimide, crosslinked polyimide, adhesive film, laminate, cover lay film, copper foil with resin, metal-clad laminate, circuit board and multilayer circuit board - Google Patents

Abstract

To provide polyimide which uses dimer diamine as a raw material, and can suppress transfer loss of a high-frequency signal when applied to a circuit board by a low dielectric loss tangent.SOLUTION: A thermoplastic polyimide contains 40 mol% or more of a diamine residue derived from a dimer diamine composition with respect to the total diamine residue, and 2-40 mol% of the total of a diamine residue derived from a diamine compound represented by the general formula (1). In the general formula (1), a connection group A represents a single bond and -COO- or -CONH-, a substituent E represents a hydrogen atom, a monovalent alkyl group which may be substituted with a halogen atom and has 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a vinyl group, an acrylic group, a methacrylic group or an allyl group, m represents 1 to 2, and p and q represent integers of 0 to 4.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a thermoplastic polyimide useful as a material for electronic parts, a crosslinked polyimide using the same, an adhesive film, a laminate, a coverlay film, a resin-coated copper foil, a metal-clad laminate, a circuit board, and a multilayer circuit board.

2. Description of the Related Art In recent years, as the performance of electronic devices is progressing, it is necessary to deal with higher frequency transmission signals. 2. Description of the Related Art When transmitting a high-frequency signal, if the transmission loss in the transmission path is large, problems such as the loss of the electrical signal and the increase in signal delay time occur. Therefore, in the future, it will be important to reduce transmission loss in circuit boards such as flexible printed circuit boards (FPCs).

In order to efficiently transmit high-frequency signals in a circuit board, it is important to reduce the dielectric loss tangent of the insulating resin layer including the adhesive layer. In order to reduce the dielectric loss tangent of the insulating resin layer, generally, a method of reducing the polar structure in the resin composition to reduce the polarity, or a method of adopting a crystalline structure like a liquid crystalline polymer is used.

Polyimide is widely used as a material for insulating resin layers of FPCs, but since polyimide for adhesive layers requires thermocompression processability, a crystalline structure that is easily irreversibly cured cannot be applied.

Patent Documents 1 and 2 attempt to reduce the dielectric loss tangent by using dimer diamine, which is an aliphatic diamine, as a raw material for polyimide.

However, in Patent Document 1, a low dielectric loss tangent is attempted by copolymerizing dimer diamine and phenylenediamine. The specifically disclosed examples use aromatic phenylenediamine in 33 to 58 mol % of the total diamine compound. Therefore, there is a concern that the adhesiveness and thermocompression bonding workability required for the polyimide for the adhesive layer may be deteriorated, and the varnish life may be deteriorated due to the deterioration of the solubility.

Further, in Patent Document 2, polyimide obtained by copolymerizing dimer diamine and a flexible diamine compound realizes a low dielectric loss tangent while ensuring adhesiveness. However, the polyimide film described in Patent Literature 2 has a dielectric loss tangent of 0.002 or more, and further improvement is required in view of the fact that the frequency of transmission signals will continue to increase in the future.

JP 2020-117631 A JP 2018-140544 A

An object of the present invention is to provide a polyimide that uses dimer diamine as a raw material and is capable of suppressing transmission loss of high-frequency signals when applied to a circuit board due to its low dielectric loss tangent.

As a result of intensive research by the present inventors, a polyimide obtained by copolymerizing a dimer diamine and a rigid diamine compound having a biphenyl skeleton or terphenyl skeleton or a -COO- group or a -CONH- group in the molecule is , the molecular mobility is suppressed and a low dielectric loss tangent is exhibited, thereby completing the present invention.

That is, the thermoplastic polyimide of the present invention is a thermoplastic polyimide containing an acid dianhydride residue derived from an acid dianhydride component and a diamine residue derived from a diamine component.
The thermoplastic polyimide of the present invention is a dimer-diamine composition mainly composed of a dimer-diamine in which two terminal carboxylic acid groups of a dimer acid are substituted with primary aminomethyl groups or amino groups with respect to all diamine residues. It contains 40 mol% or more of the diamine residue derived from the diamine residue and contains a total of 2 to 40 mol% of the diamine residue derived from the diamine compound represented by the following general formula (1). Characterized by

In the general formula (1), the connecting group A represents a single bond or a divalent group selected from -COO- or -CONH-, the substituent E is independently a hydrogen atom, even if substituted with a halogen atom a monovalent alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a vinyl group, an acrylic group, a methacrylic group or an allyl group; m is an integer of 1 to 2; p and q are Each independently represents an integer from 0 to 4.

The thermoplastic polyimide of the present invention may have a weight average molecular weight (Mw) within the range of 5,000 or more and 200,000 or less.

The thermoplastic polyimide of the present invention may contain 10 mol % or more of acid dianhydride residues derived from benzophenonetetracarboxylic acid dianhydride with respect to all acid dianhydride residues.

In the thermoplastic polyimide of the present invention, the diamine residue may contain a diamine residue derived from a diamine compound having a substituent having a carbon-carbon double bond.

In the thermoplastic polyimide of the present invention, a ketone group contained in the thermoplastic polyimide and an amino group of an amino compound having at least two primary amino groups as functional groups form a crosslinked structure through a C=N bond. may be

The thermoplastic polyimide of the present invention may form a crosslinked structure with the carbon-carbon double bond contained in the thermoplastic polyimide.

The adhesive film of the present invention is characterized by containing the above thermoplastic polyimide or crosslinked polyimide.

The adhesive film of the present invention has a dielectric loss tangent (Tan δ ) may be less than 0.002.

A laminate of the present invention is a laminate having a substrate and an adhesive layer laminated on at least one surface of the substrate, wherein the adhesive layer is made of the above adhesive film.

The coverlay film of the present invention is a coverlay film having a coverlay film material layer and an adhesive layer laminated on the coverlay film material layer, wherein the adhesive layer comprises the adhesive film consists of

The resin-coated copper foil of the present invention is a resin-coated copper foil obtained by laminating an adhesive layer and a copper foil, wherein the adhesive layer comprises the adhesive film.

The metal-clad laminate of the present invention is a metal-clad laminate having an insulating resin layer and a metal layer laminated on at least one surface of the insulating resin layer, wherein at least one of the insulating resin layers comprises , the above adhesive film.

The metal-clad laminate of the present invention comprises an insulating resin layer, an adhesive layer laminated on at least one surface of the insulating resin layer, and a metal layer laminated on the insulating resin layer via the adhesive layer. , wherein the adhesive layer comprises the adhesive film.

A metal-clad laminate of the present invention is a first single-sided metal-clad laminate having a first metal layer and a first insulating resin layer laminated on at least one surface of the first metal layer. ,
a second single-sided metal-clad laminate having a second metal layer and a second insulating resin layer laminated on at least one surface of the second metal layer;
arranged to abut on the first insulating resin layer and the second insulating resin layer and laminated between the first single-sided metal-clad laminate and the second single-sided metal-clad laminate A metal-clad laminate comprising an adhesive layer,
The adhesive layer is made of the adhesive film.

The metal-clad laminate of the present invention comprises a single-sided metal-clad laminate having an insulating resin layer and a metal layer laminated on one side of the insulating resin layer, and laminated on the other side of the insulating resin layer. and an adhesive layer formed of the above adhesive film.

The circuit board of the present invention is obtained by wiring the metal layer of the metal-clad laminate.

The circuit board of the present invention comprises a first base material, a wiring layer laminated on at least one surface of the first base material, and the wiring layer on the wiring layer side surface of the first base material. and an adhesive layer laminated so as to cover the substrate, wherein the adhesive layer is made of the adhesive film.

The circuit board of the present invention comprises a first base material, a wiring layer laminated on at least one surface of the first base material, and the wiring layer on the wiring layer side surface of the first base material. A circuit board comprising an adhesive layer laminated so as to cover the and a second base laminated on the surface of the adhesive layer opposite to the first base, The adhesive layer is made of the above adhesive film.

The circuit board of the present invention comprises: a first substrate; an adhesive layer laminated on at least one surface of the first substrate; A circuit board comprising: a second substrate laminated on a surface thereof; and wiring layers respectively laminated on surfaces of the first substrate and the second substrate opposite to the adhesive layer. and the adhesive layer is made of the adhesive film.

A multilayer circuit board of the present invention is a multilayer circuit board comprising a laminate including a plurality of laminated insulating resin layers and at least one or more wiring layers embedded in the laminate,
At least one of the plurality of insulating resin layers is formed of an adhesive layer that has adhesiveness and covers the wiring layer, and the adhesive layer is made of the adhesive film.

The thermoplastic polyimide of the present invention is obtained by copolymerizing the dimer diamine and the diamine compound represented by the general formula (1), so that it has good solubility, low dielectric loss tangent, adhesiveness and thermocompression bonding processability. It is possible to form a polyimide film excellent in Therefore, when the polyimide film obtained from the thermoplastic polyimide of the present invention is applied to a circuit board or the like that transmits high frequency signals in the GHz band (for example, 1 to 40 GHz), the transmission loss in high frequency signal transmission can be effectively reduced. can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the structure of the cross section of the laminated body which concerns on embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the structure of the cross section of the metal-clad laminated board which concerns on embodiment of this invention. FIG. 4 is a schematic diagram showing a cross-sectional configuration of a metal-clad laminate according to another embodiment of the present invention; FIG. 4 is a schematic diagram showing a cross-sectional configuration of a metal-clad laminate according to still another embodiment of the present invention; BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the structure of the cross section of the circuit board which concerns on embodiment of this invention. It is a schematic diagram which shows the structure of the cross section of the circuit board which concerns on another embodiment of this invention. FIG. 4 is a schematic diagram showing a cross-sectional configuration of a circuit board according to still another embodiment of the present invention; 1 is a schematic diagram showing a cross-sectional configuration of a multilayer circuit board according to an embodiment of the present invention; FIG.

Embodiments of the present invention will be described with reference to the drawings as appropriate. Since the thermoplastic polyimide according to one embodiment of the present invention is thermoplastic, it has high adhesiveness and thermocompression bonding processability, and can be used as an adhesive. Hereinafter, the polyimide of this embodiment may be referred to as "adhesive polyimide". The term "thermoplastic polyimide" generally refers to a polyimide that can be softened by heating and solidified by cooling, which can be repeated, and whose glass transition temperature can be clearly confirmed. means a polyimide whose glass transition temperature can be clearly confirmed at . Further, the thermoplastic polyimide is preferably a polyimide whose glass transition temperature can be clearly confirmed in a temperature range of less than 100 ° C. from the viewpoint of thermocompression bonding at low temperatures, and is measured using a dynamic viscoelasticity measurement device (DMA). More preferably, it has a storage modulus of 1.0×10 ⁸ Pa or more at 30° C. and a storage modulus of less than 1.0×10 ⁷ Pa at the glass transition temperature +30° C. On the other hand, "non-thermoplastic polyimide" refers to polyimide that does not soften or exhibit adhesiveness when heated. C. storage modulus is 1.0×10 ⁹ Pa or more and storage modulus at 300° C. is 1.0×10 ⁸ Pa or more.

The adhesive polyimide contains dianhydride residues derived from the dianhydride component and diamine residues derived from the diamine component. When the acid dianhydride and diamine compound as raw materials are reacted in approximately equimolar amounts, the type and amount of acid dianhydride residue and diamine residue contained in the polyimide with respect to the type and molar ratio of the raw materials The molar ratios can be approximately matched.
In the present invention, the term "polyimide" means a resin composed of a polymer having an imide group in its molecular structure, such as polyimide, polyetherimide, polyesterimide, polysiloxaneimide, and polybenzimidazoleimide, in addition to polyimide. .

The acid dianhydride residue and diamine residue constituting the adhesive polyimide are described below together with the raw materials thereof.

(Acid dianhydride)
For the adhesive polyimide, any acid dianhydride generally used for thermoplastic polyimide can be used as a raw material without any particular limitation. Such acid dianhydrides include, for example, 3,3′,4,4′-, 2,3′,3,4′-, 2,2′,3,3′- or 2,3,3 ',4'-benzophenonetetracarboxylic dianhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA ), 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride (DSDA), 4,4′-oxydiphthalic anhydride (ODPA), 4,4′-(hexafluoroisopropylidene)diphthalic acid Anhydride (6FDA), 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (BPADA), p-phenylenebis(trimellitic acid monoester acid anhydride) (TAHQ) , ethylene glycol bisanhydrotrimellitate (TMEG), pyromellitic dianhydride, 2,3′,3,4′-diphenyl ether tetracarboxylic dianhydride, bis(2,3-dicarboxyphenyl) ether anhydride, 3,3'',4,4''-, 2,3,3'',4''- or 2,2'',3,3''-p-terphenyltetracarboxylic dianhydride 2,2-bis(2,3- or 3,4-dicarboxyphenyl)-propane dianhydride, bis(2,3- or 3,4-dicarboxyphenyl)methane dianhydride, bis(2 ,3- or 3,4-dicarboxyphenyl)sulfone dianhydride, 1,1-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, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6 ,7-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-tetracarboxylic dianhydride, 2,3,6,7-(or 1,4,5,8-)tetrachloronaphthalene-1, 4,5,8- (or 2,3,6,7-) tetracarboxylic dianhydride, 2,3,8,9-, 3,4,9,10-, 4,5, 10,11- or 5,6,11,12-perylene-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetra aromatic tetracarboxylic dianhydrides such as carboxylic dianhydrides, thiophene-2,3,4,5-tetracarboxylic dianhydrides, and 4,4'-bis(2,3-dicarboxyphenoxy)diphenylmethane dianhydrides; anhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride 1,2,4,5-cycloheptanetetracarboxylic dianhydride, 1,2,5,6-cyclooctanetetracarboxylic dianhydride and other alicyclic tetracarboxylic dianhydrides can be done.

Here, when cross-linking is performed using a ketone group (carbonyl group) contained in the adhesive polyimide as described later, benzophenonetetracarboxylic dianhydride is preferably used for all dianhydride components. is preferably 10 mol % or more, more preferably 50 mol % or more. In other words, the adhesive polyimide contains acid dianhydride residues derived from benzophenonetetracarboxylic acid dianhydride in an amount of preferably 10 mol % or more, more preferably 50 mol %, based on all acid dianhydride residues. It is preferable to contain mol% or more. Flexibility and heat resistance of the adhesive polyimide are improved by containing 10 mol% or more of the acid dianhydride residue derived from benzophenonetetracarboxylic acid dianhydride in total with respect to the total acid dianhydride residue. Both are easily achieved, and the carbonyl group (ketone group) contributes to the adhesiveness, so the adhesiveness of the adhesive polyimide can be improved. Here, if the content of the acid dianhydride residue derived from benzophenonetetracarboxylic dianhydride is less than 10 mol% in total with respect to the total acid dianhydride residue, the cross-linking point in the cross-linking formation described later Since the number of ketone groups (carbonyl groups) to be used is reduced, it is disadvantageous from the viewpoint of improving solder heat resistance. Incidentally, benzophenonetetracarboxylic dianhydride is 3,3′,4,4′-, 2,3′,3,4′-, 2,2′,3,3′- or 2,3,3′- ,4'-benzophenonetetracarboxylic dianhydride can be used.

(diamine)
For the adhesive polyimide, any diamine compound generally used for thermoplastic polyimide can be used as a raw material without any particular limitation. 40 mol% or more, preferably 40 mol% or more and 98 mol% or less, more preferably 60 mol% or more, of a diamine residue derived from a dimer diamine composition mainly composed of dimer diamine substituted with a group It is contained within the range of 95 mol % or less. By containing the diamine residue derived from the dimer diamine composition within the above range, the solubility of the polyimide can be improved, and the dielectric constant and dielectric loss tangent can be lowered. When the content of diamine residues derived from the dimer diamine composition is less than 40 mol% relative to the total diamine residues, the relative dielectric constant and dielectric loss tangent increase due to the relative increase in polar groups contained in the polyimide. easier to do. In addition, by containing the diamine residue derived from the dimer diamine composition in the above amount, the thermocompression bonding property is improved by lowering the glass transition temperature of the polyimide (lowering Tg) and the internal stress is reduced by lowering the elastic modulus. mitigation becomes possible. On the other hand, if the content of diamine residues derived from the dimer diamine composition exceeds 98 mol% relative to all diamine residues, the mobility of the polyimide molecular chains is excessively increased, and the dielectric loss tangent may increase. .

The dimer diamine composition is a purified product containing the following component (a) as a main component and having controlled amounts of components (b) and (c).

(a) a dimer diamine;
The dimer diamine of component (a) means that the two terminal carboxylic acid groups (--COOH) of the dimer acid are substituted with primary aminomethyl groups ( _--CH.sub.2 -- _NH.sub.2 ) or amino groups ( _--NH.sub.2 ). means a diamine consisting of Dimer acid is a known dibasic acid obtained by an intermolecular polymerization reaction of unsaturated fatty acids, and its industrial production process is almost standardized in the industry. It is obtained by dimerization with Etc. Industrially obtained dimer acids are mainly composed of dibasic acids with 36 carbon atoms obtained by dimerizing unsaturated fatty acids with 18 carbon atoms such as oleic acid, linoleic acid and linolenic acid. To some extent, it contains any amount of monomeric acid (18 carbon atoms), trimer acid (54 carbon atoms), other polymerized fatty acids of 20 to 54 carbon atoms. Moreover, although a double bond remains after the dimerization reaction, in the present invention, the dimer acid includes the one which is further hydrogenated to reduce the degree of unsaturation. The dimer diamine of the component (a) is obtained by substituting the terminal carboxylic acid group of the dibasic acid compound having 18 to 54 carbon atoms, preferably 22 to 44 carbon atoms, with a primary aminomethyl group or an amino group. can be defined as the resulting diamine compound.

As a feature of the dimer diamine, properties derived from the dimer acid skeleton can be imparted. That is, the dimer diamine is a macromolecular aliphatic with a molecular weight of about 560-620, so that the molar volume of the molecule can be increased and the polar groups of the polyimide can be relatively reduced. Such features of the dimer acid-type diamine are considered to contribute to improving the dielectric properties by reducing the dielectric constant and the dielectric loss tangent while suppressing the deterioration of the heat resistance of the polyimide. In addition, since it has two freely moving hydrophobic chains having 7 to 9 carbon atoms and two chain aliphatic amino groups having a length close to 18 carbon atoms, it not only gives the polyimide flexibility, Since polyimide can have an asymmetric chemical structure or a non-planar chemical structure, it is thought that the dielectric constant of polyimide can be lowered.

The dimer-diamine composition used is obtained by increasing the dimer-diamine content of component (a) to 96% by weight or more, preferably 97% by weight or more, and more preferably 98% by weight or more by a purification method such as molecular distillation. It's good. By setting the dimer diamine content of the component (a) to 96% by weight or more, it is possible to suppress the spread of the molecular weight distribution of the polyimide. In addition, if technically possible, it is best that all (100% by weight) of the dimer diamine composition is composed of the dimer diamine of the component (a).

(b) a monoamine compound obtained by substituting a primary aminomethyl group or an amino group for the terminal carboxylic acid group of a monobasic acid compound having 10 to 40 carbon atoms;
The monobasic acid compound having 10 to 40 carbon atoms is a monobasic unsaturated fatty acid having 10 to 20 carbon atoms derived from the dimer acid raw material, and a by-product during the production of dimer acid. is a mixture of monobasic acid compounds within the range of 21 to 40 carbon atoms. A monoamine compound is obtained by substituting the terminal carboxylic acid group of these monobasic acid compounds with a primary aminomethyl group or an amino group.

The monoamine compound of component (b) is a component that suppresses an increase in the molecular weight of polyimide. When polyamic acid or polyimide is polymerized, the monofunctional amino group of the monoamine compound reacts with the terminal acid anhydride group of polyamic acid or polyimide to seal the terminal acid anhydride group, thereby reducing the molecular weight of polyamic acid or polyimide. restrain the increase.

(c) an amine compound obtained by substituting a primary aminomethyl group or an amino group for the terminal carboxylic acid group of a polybasic acid compound having a hydrocarbon group within the range of 41 to 80 carbon atoms (wherein the dimer diamine except for);
The polybasic acid compound having a hydrocarbon group having 41 to 80 carbon atoms is mainly composed of a tribasic acid compound having 41 to 80 carbon atoms, which is a by-product of dimer acid production. It is a polybasic acid compound that Further, polymerized fatty acid other than dimer acid having 41 to 80 carbon atoms may be included. Amine compounds are obtained by substituting the terminal carboxylic acid groups of these polybasic acid compounds with primary aminomethyl groups or amino groups.

The amine compound (c) is a component that promotes an increase in the molecular weight of the polyimide. A trifunctional or higher functional amino group whose main component is a triamine derivative derived from trimer acid reacts with the terminal acid anhydride group of polyamic acid or polyimide to rapidly increase the molecular weight of polyimide. Amine compounds derived from polymerized fatty acids other than dimer acids having 41 to 80 carbon atoms also increase the molecular weight of polyimide and cause gelation of polyamic acid or polyimide.

When quantifying each component by measurement using gel permeation chromatography (GPC), the dimer diamine composition is added to facilitate confirmation of the peak start, peak top and peak end of each component of the dimer diamine composition. Samples treated with acetic anhydride and pyridine are used and cyclohexanone is used as internal standard. Using samples prepared in this way, each component is quantified by area percent of the GPC chromatogram. The peak start and peak end of each component are the minimum values of each peak curve, and the area percentage of the chromatogram can be calculated based on this.

Further, in the dimer diamine composition, the sum of components (b) and (c) should be 4% or less, preferably less than 4%, in terms of area percent in a chromatogram obtained by GPC measurement. By setting the total content of components (b) and (c) to 4% or less, it is possible to suppress broadening of the molecular weight distribution of the polyimide.

Also, the area percentage of the component (b) in the chromatogram is preferably 3% or less, more preferably 2% or less, and still more preferably 1% or less. By setting it in such a range, it is possible to suppress the decrease in the molecular weight of the polyimide, and further to widen the range of the molar ratio of the tetracarboxylic dianhydride component and the diamine component. In addition, the component (b) may not be contained in the dimer diamine composition.

The area percentage of component (c) in the chromatogram is 2% or less, preferably 1.8% or less, and more preferably 1.5% or less. Such a range can suppress a rapid increase in the molecular weight of the polyimide, and further suppress an increase in the dielectric loss tangent of the resin film over a wide frequency range. In addition, the (c) component may not be contained in the dimer diamine composition.

Further, when the area percent ratio (b/c) of the chromatograms of components (b) and (c) is 1 or more, the molar ratio of the tetracarboxylic dianhydride component and the diamine component (tetracarboxylic dianhydride component/diamine component) is preferably 0.97 or more and less than 1.0, and such a molar ratio makes it easier to control the molecular weight of the polyimide.

Further, when the area percent ratio (b/c) of the chromatograms of components (b) and (c) is less than 1, the molar ratio of the tetracarboxylic dianhydride component and the diamine component (tetracarboxylic dianhydride The ratio of polyimide component/diamine component) is preferably 0.97 or more and 1.1 or less, and such a molar ratio makes it easier to control the molecular weight of the polyimide.

The dimer-diamine composition is commercially available, and is preferably purified for the purpose of reducing components other than the dimer-diamine component (a). For example, the component (a) is preferably 96 area percent or more. . The purification method is not particularly limited, but known methods such as distillation and precipitation purification are suitable. Examples of commercially available dimer diamine compositions include PRIAMINE 1073 (trade name), PRIAMINE 1074 (trade name), and PRIAMINE 1075 (trade name) manufactured by Croda Japan.

In addition, the adhesive polyimide contains a total of 2 to 40 mol% of diamine residues derived from at least one selected from diamine compounds represented by the following general formula (1) with respect to all diamine residues. preferably within the range of 5 to 40 mol %, more preferably within the range of 5 to 30 mol %, still more preferably within the range of 10 to 30 mol %. If the total content of diamine residues derived from the diamine compound represented by the general formula (1) is less than 2 mol% with respect to all diamine residues, the effect of lowering the dielectric loss tangent is not sufficiently exhibited. On the other hand, if the total content of diamine residues derived from the diamine compound represented by the general formula (1) exceeds 40 mol% with respect to all diamine residues, adhesiveness and thermocompression bonding workability are reduced. Sometimes.

In the general formula (1), the connecting group A represents a single bond or a divalent group selected from -COO- or -CONH-, the substituent E is independently a hydrogen atom, even if substituted with a halogen atom a monovalent alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a vinyl group, an acrylic group, a methacrylic group or an allyl group; m is an integer of 1 to 2; p and q are Each independently represents an integer from 0 to 4.

By using the diamine compound represented by the general formula (1) together with the dimer diamine composition as the raw material monomer, the molecular motion of the polyimide molecular chains can be suppressed and the dielectric loss tangent can be reduced. That is, the diamine compound represented by the general formula (1) has a highly rigid biphenyl skeleton or terphenyl skeleton in the molecule, or has a highly rigid linking group A of adjacent aromatic rings. Since it has a --COO-- group or --CONH-- group and has a structure in which the two amino groups and the linking group A are in the para position, the molecular structure is highly linear. Therefore, by replacing a portion of the diamine residues with diamine residues derived from the diamine compound represented by the general formula (1), compared to the case where all of the diamine residues are diamine residues derived from the dimer diamine composition, It is thought that it becomes possible to suppress the movement of the polyimide molecular chain as a whole and to achieve a low dielectric loss tangent.

In addition, since the diamine residue derived from the dimer diamine composition has the function of imparting excellent solvent solubility to the adhesive polyimide, the amount of diamine residue derived from the dimer diamine composition is reduced. However, since the diamine compound represented by the general formula (1) has a large effect of lowering the dielectric loss tangent even in a small amount, it impairs the solvent solubility of the adhesive polyimide. A low dielectric loss tangent can be achieved with a small usage amount.

Thus, the diamine compound represented by the general formula (1) has a large effect of suppressing molecular motion, and a small amount can sufficiently lower the dielectric loss tangent. Unlike diamines, there is little fear of lowering the adhesiveness and thermocompression bonding processability required for adhesive applications, and there is no concern of lowering solvent solubility and deteriorating varnish life.

Specific examples of the diamine compound represented by formula (1) include:
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 ), 4,4′-diaminobiphenyl, 2,2′-dimethoxy-4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 3,3′-diethyl-4,4 '-diaminobiphenyl, 3,3'-diethoxy-4,4'-diaminobiphenyl, 3,3'-dipropoxy-4,4'-diaminobiphenyl, 3,3'-n-propyl-4,4'-diamino Biphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3',5,5'-tetramethylbenzidine, 2,2'-ditrifluoromethylbenzidine (TFMB), 4,4'-diamino -2,2',5,5'-tetrachlorobiphenyl, 4,4'-diaminooctafluorobiphenyl, 4-aminophenyl-4'-aminobenzoate (APAB), 4,4'-diaminobenzanilide, 2'-methoxy-4,4'-diaminobenzanilide,2,2'-divinyl-4,4'-diaminobiphenyl (VAB), 4,4'-diamino-p-terphenyl and the like.
Among these, 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB), from the viewpoint of increasing the orientation of the molecular chain and efficiently suppressing the molecular movement from the side chain length and the bonding position, 2,2'-ditrifluoromethylbenzidine (TFMB), and 2,2'-divinyl-4, from the viewpoint of efficiently suppressing the mobility of the molecular chain with the addition of electronic interaction due to the conjugated structure of the side chain. 4'-Diaminobiphenyl (VAB) is preferred.

In addition to the above, the adhesive polyimide may contain a diamine residue derived from a diamine compound generally used for thermoplastic polyimides, as long as the effect of the invention is not impaired.

The adhesive polyimide can be produced by reacting the acid anhydride component and the diamine component in a solvent to form a polyamic acid, followed by heating and ring closure. For example, an acid anhydride component and a diamine component are dissolved in an organic solvent in approximately equimolar amounts and stirred at a temperature within the range of 0 to 100° C. for 30 minutes to 24 hours for a polymerization reaction to obtain a polyimide precursor. A polyamic acid is obtained. In the reaction, the reaction components are dissolved in the organic solvent so that the resulting precursor is within the range of 5 to 50% by weight, preferably within the range of 10 to 40% by weight. Examples of organic solvents used in the polymerization reaction include N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N,N-diethylacetamide, N-methyl-2-pyrrolidone (NMP), 2 -butanone, dimethylsulfoxide (DMSO), hexamethylphosphoramide, N-methylcaprolactam, dimethyl sulfate, cyclohexanone, methylcyclohexane, dioxane, tetrahydrofuran, diglyme, triglyme, methanol, ethanol, benzyl alcohol, cresol and the like. Two or more of these solvents can be used, and aromatic hydrocarbons such as xylene and toluene can also be used in combination. The amount of such an organic solvent to be used is not particularly limited, but the amount used is adjusted so that the concentration of the polyamic acid solution obtained by the polymerization reaction is about 5 to 50% by weight. is preferred.

It is usually advantageous to use the synthesized polyamic acid as a reaction solvent solution, but if necessary, it can be concentrated, diluted, or replaced with another organic solvent. Also, polyamic acid is generally excellent in solvent solubility, and is thus advantageously used. The viscosity of the polyamic acid solution is preferably in the range of 500 mPa·s to 100000 mPa·s. If the thickness is out of this range, defects such as thickness unevenness and streaks are likely to occur in the film during the coating operation using a coater or the like.

The method of imidizing the polyamic acid to form a polyimide is not particularly limited, for example, a heat treatment such as heating for 1 to 24 hours under a temperature condition within the range of 80 to 400 ° C. in the solvent is preferably employed. be done. Moreover, the temperature may be heated under constant temperature conditions, or the temperature may be changed during the process.

In the adhesive polyimide, dielectric properties, thermal expansion coefficient, Physical properties such as tensile modulus and glass transition temperature can be controlled. When the adhesive polyimide has a plurality of structural units, they may be present as blocks or randomly, but preferably randomly.

The adhesive polyimide obtained as described above is a solvent-soluble polyimide that is soluble in an organic solvent such as N-methyl-2-pyrrolidone (NMP) by containing a certain amount or more of residues derived from dimer diamine. and is suitable for application to substrates such as metal foils.

The adhesive polyimide preferably has a weight average molecular weight (Mw) within the range of 5,000 to 200,000. If the Mw of the adhesive polyimide is less than 5,000, it tends to become brittle when formed into a film. On the other hand, if the Mw exceeds 200,000, the viscosity of the varnish will be high, and thickness unevenness will likely occur during coating.
A more preferable range of Mw of the adhesive polyimide is in the range of 10,000 to 60,000, more preferably in the range of 20,000 to 60,000. If the Mw is less than 10,000, the number of highly polar acid terminals increases in the polyimide molecular chain, so that the dielectric constant and dielectric loss tangent tend to increase. Further, when Mw exceeds 60,000, the length of the molecular chain becomes long, so that the effect of copolymerizing the dimer diamine and the diamine compound represented by the general formula (1) becomes difficult to manifest, and the dielectric constant and dielectric constant are reduced. Tangent may tend to rise.

In addition, the adhesive polyimide preferably has a ratio (Mw/Mn) of Mw to number average molecular weight (Mn) in the range of 1.5 to 2.8, more preferably in the range of 1.8 to 2.8. There should be
The ratio Mw/Mn represents polydispersity, and the adhesive polyimide of the present embodiment preferably has a ratio Mw/Mn of 1.5 or more. Even if the Mn is about the same, the higher the degree of dispersion, the higher the frequency of high-molecular-weight substances. Therefore, the motion suppression due to the entanglement of molecules is enhanced, and the dielectric loss tangent can be lowered and the tear strength can be improved. In addition, since Mn represents the number of terminals of the polyimide chain more directly than Mw, the ratio Mw/Mn is set to 2.8 or less, and by balancing with Mn while ensuring a certain degree of dispersion, the polyimide molecule It is possible to suppress an increase in the number of highly polar ends in the chain and suppress an increase in the dielectric constant and dielectric loss tangent. Control of Mn is possible by increasing the content of dimer diamine in the dimer diamine composition (that is, by reducing the trimer component and monomer component), thereby suppressing the spread of the molecular weight of the adhesive polyimide. can be done.

The imide group concentration of the adhesive polyimide is preferably 22% by weight or less, more preferably in the range of 15 to 22% by weight, still more preferably in the range of 18 to 22% by weight. Here, "imide group concentration" means a value obtained by dividing the molecular weight of the imide group (-(CO) ₂ -N-) in the polyimide by the molecular weight of the entire structure of the polyimide. When the imide group concentration exceeds 22% by weight, the molecular weight of the resin itself becomes small, and the low hygroscopicity deteriorates due to the increase in polar groups, resulting in an increase in Tg and elastic modulus.

Adhesive polyimides are most preferably fully imidized structures. However, part of the polyimide may be amic acid. The imidization rate is around 1015 cm ⁻¹ by measuring the infrared absorption spectrum of the polyimide thin film by the single reflection ATR method using a Fourier transform infrared spectrophotometer (commercial product: FT/IR620 manufactured by JASCO Corporation). can be calculated from the absorbance of C═O stretching derived from the imide group at 1780 cm ⁻¹ based on the benzene ring absorber of .

Adhesive polyimide is an optional component, for example, a plasticizer, other curing resin components such as epoxy resins, curing agents, curing accelerators, organic fillers, inorganic fillers, coupling agents, flame retardants, etc. By appropriately blending, It can be an adhesive composition.

(Crosslinking of adhesive polyimide)
Adhesive polyimides can be crosslinked in a variety of ways. Formation of the crosslinked structure can significantly improve the heat resistance of the adhesive polyimide. Adhesive polyimide with a crosslinked structure (hereinafter sometimes referred to as “crosslinked polyimide”) is an application example of adhesive polyimide and is a preferred form. Since the Mw varies greatly due to the formation of crosslinks, the Mw of the crosslinked polyimide is a different value from the Mw of the adhesive polyimide before the formation of the crosslinks. Cross-linking by imine bonds (C=N bonds) and cross-linking by carbon-carbon double bonds will be described below.

(A) Crosslink formation by imine bond (C=N bond):
When the adhesive polyimide has a ketone group, the amino of the ketone group and an amino compound having at least two primary amino groups as functional groups (hereinafter sometimes referred to as "crosslink-forming amino compound") A crosslinked structure can be formed by reacting the groups to form a C=N bond. Further, an adhesive composition in which an adhesive polyimide having a ketone group is blended with a cross-linking agent is another application example and is a preferred embodiment. Preferred tetracarboxylic dianhydrides for forming adhesive polyimides having ketone groups include, for example, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA), and diamine compounds such as Examples thereof include aromatic diamines such as 4,4'-bis(3-aminophenoxy)benzophenone (BABP) and 1,3-bis[4-(3-aminophenoxy)benzoyl]benzene (BABB).

For the purpose of forming a crosslinked structure, in particular, the BTDA residue derived from BTDA is preferably in the range of 50 mol% or more and 100 mol% or less, more preferably 60 mol, relative to the total acid dianhydride residue. % or more and 100 mol % or less of the adhesive polyimide is preferably reacted with the amino compound for cross-linking. In the present invention, "BTDA residue" means a tetravalent group derived from BTDA.

Examples of cross-linking amino compounds include (I) dihydrazide compounds, (II) aromatic diamines, and (III) aliphatic amines. Among these, dihydrazide compounds are preferred. Aliphatic amines other than dihydrazide compounds tend to form a crosslinked structure even at room temperature, and there is concern about the storage stability of varnishes. On the other hand, aromatic diamines require a high temperature to form a crosslinked structure. When a dihydrazide compound is used, both the storage stability of the varnish and the shortening of the curing time can be achieved. Examples of dihydrazide compounds include oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, dodecanedioic acid dihydrazide, and maleic acid. dihydrazide, fumaric dihydrazide, diglycolic acid dihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, phthalic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, 2,6-naphthoic acid dihydrazide, 4,4-bisbenzene dihydrazide, 1,4- Dihydrazide compounds such as naphthoic acid dihydrazide, 2,6-pyridinedioic acid dihydrazide, and itaconic acid dihydrazide are preferred. The above dihydrazide compounds may be used alone or in combination of two or more.

In addition, amino compounds such as (I) dihydrazide compounds, (II) aromatic diamines, and (III) aliphatic amines are, for example, a combination of (I) and (II), a combination of (I) and (III), Two or more types can also be used in combination across categories, such as combinations of (I), (II) and (III).

In addition, from the viewpoint of making the network structure formed by cross-linking by the cross-linking amino compound denser, the cross-linking amino compound used in the present invention has a molecular weight (when the cross-linking amino compound is an oligomer (weight average molecular weight) is preferably 5,000 or less, more preferably 90 to 2,000, still more preferably 100 to 1,500. Among these, a cross-linking amino compound having a molecular weight of 100 to 1,000 is particularly preferred. When the molecular weight of the cross-linking amino compound is less than 90, only one amino group of the cross-linking amino compound forms a C=N bond with the ketone group of the adhesive polyimide, and the surroundings of the remaining amino groups are steric. , the remaining amino groups tend to be less likely to form C=N bonds.

When cross-linking the ketone groups in the adhesive polyimide and the amino compound for cross-linking, the amino compound for cross-linking is added to the resin solution containing the adhesive polyimide to form cross-links with the ketone groups in the adhesive polyimide. condensation reaction with the primary amino group of the amino compound for use. Due to this condensation reaction, the resin solution is cured into a cured product. In this case, the amount of the cross-linking amino compound to be added is 0.004 mol to 1.5 mol, preferably 0.005 mol to 1.2 mol, in total of the primary amino group per 1 mol of the ketone group. More preferably 0.03 mol to 0.9 mol, most preferably 0.04 mol to 0.6 mol. If the amount of the cross-linking amino compound added is less than 0.004 mol in total for the primary amino group per 1 mol of the ketone group, the cross-linking by the cross-linking amino compound is not sufficient. Heat resistance tends to be difficult to develop, and if the amount of the amino compound for cross-linking exceeds 1.5 mol, the unreacted amino compound for cross-linking acts as a thermoplastic, reducing the heat resistance of the adhesive layer. tend to let

Condensation reaction conditions for crosslink formation are conditions under which the ketone group in the adhesive polyimide reacts with the primary amino group of the amino compound for crosslink formation to form an imine bond (C=N bond). There are no particular restrictions. The temperature of the heat condensation is, for example, 120° C. for reasons such as releasing water generated by the condensation to the outside of the system, or simplifying the condensation step when the heat condensation reaction is subsequently performed after the synthesis of the adhesive polyimide. It is preferably within the range of -220°C, more preferably within the range of 140-200°C. The reaction time is preferably about 30 minutes to 24 hours. The end point of the reaction, for example, using a Fourier transform infrared spectrophotometer (commercial product: FT/IR620 manufactured by JASCO Corporation), by measuring the infrared absorption spectrum, absorption derived from the ketone groups in the polyimide resin near 1670 cm ^-1 It can be confirmed by the decrease or disappearance of the peak and the appearance of an absorption peak derived from the imine group near 1635 cm ⁻¹ .

The heat condensation of the ketone group of the adhesive polyimide and the primary amino group of the amino compound for cross-linking can be carried out by, for example,
(1) A method of adding an amino compound for cross-linking and heating following the synthesis (imidization) of an adhesive polyimide,
(2) An excess amount of an amino compound is charged in advance as a diamine component, and following the synthesis (imidation) of an adhesive polyimide, the remaining amino compound that is not involved in imidization or amidation is used as an amino compound for forming crosslinks. a method of heating with an adhesive polyimide,
or
(3) After processing the adhesive polyimide solution (adhesive composition) to which the above amino compound for cross-linking is added (adhesive composition) into a predetermined shape (for example, after coating on an arbitrary substrate or after forming into a film) how to heat to
etc.

(B) Cross-linking using carbon-carbon double bonds:
Adhesive polyimide contains highly reactive carbon-carbon double bonds (reactive double bonds), making it possible to form crosslinks using these bonds, which can further improve solder heat resistance and flame retardancy. can. For this purpose, the adhesive polyimide is a diamine residue derived from a diamine compound having a substituent containing a reactive double bond (hereinafter referred to as "reactive double bond-containing diamine residue"). There is) is preferably contained. Examples of reactive double bonds include carbon-carbon double bonds contained in vinyl groups, acrylic groups (acrylate groups), methacrylic groups (methacrylate groups), and allyl groups. Therefore, as a diamine compound having a substituent containing a reactive double bond, the substituent E in the general formula (1) is a vinyl group, an acryl group, a methacryl group or an allyl group, and p or q is 1 or more. can be mentioned.

When cross-linking is performed using reactive double bonds, the reactive double bond-containing diamine residues are preferably in the range of 5 mol% or more and 25 mol% or less with respect to all diamine residues in the adhesive polyimide. More preferably, it should be contained within the range of 10 mol % or more and 20 mol % or less. If the diamine residue derived from the diamine compound containing a reactive double bond is less than 5 mol%, cross-linking may be insufficient. Polymerization reactions between groups are likely to occur, making it difficult to form crosslinks.

For cross-linking, it is preferable to react a cross-linking agent with the adhesive polyimide having a reactive double bond-containing diamine residue. The cross-linking agent may be a compound having a functional group in the molecule capable of forming a cross-link by reacting with the reactive double bond in the adhesive polyimide. Examples of such functional groups include vinyl groups and acrylic groups. (acrylate group), methacrylic group (methacrylate group), allyl group, acryloyl group, and the like. Examples of compounds having such functional groups include 1,5-hexadiene, triallylamine, and dipentaerythritol hexaacrylate. A compound containing an atom such as phosphorus in the molecule may be used as the cross-linking agent, and in this case, an effect of improving the flame retardancy of the resin film after cross-linking can be expected.

The cross-linking agent is preferably used within a range of 5 parts by weight or more and 30 parts by weight or less, and 10 parts by weight or more and 25 parts by weight, with respect to 100 parts by weight of the adhesive polyimide having a reactive double bond-containing diamine residue. It is more preferable to be within the following range. If the amount of the cross-linking agent is less than 5 parts by weight, cross-linking will not proceed sufficiently, making it difficult to improve solder heat resistance and flame retardancy. If the amount of the cross-linking agent exceeds 30 parts by weight, the unreacted cross-linking agent may bleed out, or the adhesiveness of the resin film formed may decrease, and the cross-linking agents may react with each other, resulting in poor handling. may decrease.

Cross-linking by the adhesive polyimide having a reactive double bond-containing diamine residue and a cross-linking agent is carried out by reacting the functional group contained in the cross-linking agent with the substituent having the reactive double bond in the adhesive polyimide. will be
For example, (i) a method of synthesizing (imidation) an adhesive polyimide having a reactive double bond-containing diamine residue, followed by heating with the addition of a cross-linking agent, (ii) a reactive double bond-containing diamine residue. After processing a resin composition containing an adhesive polyimide and a cross-linking agent having a predetermined shape (for example, after applying it to an arbitrary substrate or after forming it into a film), it can be performed by a method of heating, etc. .
The reaction conditions for cross-linking are not particularly limited, but, for example, a method of heating within the range of 100 to 220° C., preferably within the range of 120 to 200° C. is preferred. The reaction time is preferably about 30 minutes to 24 hours. Here, a polymerization initiator may be used, if necessary, in order to hasten the initiation of the reaction.

As the polymerization initiator, those commonly used as radical polymerization initiators can be used without particular limitation, and preferred examples include dihalogen compounds, azo compounds, organic peroxides, and the like. Among these, organic peroxides are preferred. Commercially available products can be appropriately selected and used as the polymerization initiator. Preferable examples of such commercially available polymerization initiators include Perbutyl (registered trademark) P (manufactured by NOF Corporation) and Perbutyl (registered trademark) C (manufactured by NOF Corporation).
The polymerization initiator is preferably used within a range of 0.5 parts by weight or more and 2.0 parts by weight or less with respect to 100 parts by weight of the adhesive polyimide having a reactive double bond-containing diamine residue. If the polymerization initiator is less than 0.5 parts by weight with respect to 100 parts by weight of the adhesive polyimide having a reactive double bond-containing diamine residue, the effect of adding the polymerization initiator may not be sufficiently exhibited. On the other hand, if the amount of the polymerization initiator exceeds 2.0 parts by weight, the dielectric loss tangent may deteriorate and the storability and handleability of the resin composition may deteriorate.

As mentioned above, in order to impart heat resistance to the adhesive polyimide, examples of cross-linking formation by imine bond (C=N bond) and cross-linking formation using double bond between carbon atoms have been described, but the examples are not limited to these. do not have. As a method for curing polyimide, for example, epoxy resin, epoxy resin curing agent, maleimide, activated ester resin, compound having an unsaturated bond such as a resin having a styrene skeleton, or the like may be blended and cured.

[Adhesive composition]
Since the adhesive polyimide is solvent-soluble, it can be used in the form of a solvent-containing adhesive composition (polyimide solution). That is, the adhesive composition contains adhesive polyimide and a solvent capable of dissolving this adhesive polyimide. In addition, the adhesive composition can contain, as optional components, the above amino compound for cross-linking, a cross-linking agent capable of forming cross-links by reacting with the above-mentioned reactive double bond, and a polymerization initiator. The adhesive composition contains adhesive polyimide as the main component of the resin component, preferably 70% by weight or more of the resin component, more preferably 90% by weight or more of the resin component, and most preferably as the entire resin component. In addition, the main component of the resin component means a component contained in an amount exceeding 50% by weight with respect to the total resin component.

The solvent is not particularly limited as long as it can dissolve the adhesive polyimide. methyl-2-pyrrolidone (NMP), 2-butanone, dimethylsulfoxide (DMSO), hexamethylphosphoramide, N-methylcaprolactam, dimethyl sulfate, cyclohexanone, methylcyclohexane, dioxane, tetrahydrofuran, diglyme, triglyme, methanol, ethanol, benzyl alcohol, cresol, acetone and the like. Two or more of these solvents can be used in combination, and aromatic hydrocarbons such as xylene and toluene can also be used in combination.

In the adhesive composition, the compounding ratio of the adhesive polyimide and the solvent is not particularly limited as long as the viscosity of the composition can be maintained to the extent that it can be coated. The viscosity of the adhesive composition is preferably within the range of, for example, 500 mPa·s to 100000 mPa·s. If the thickness is out of this range, defects such as thickness unevenness and streaks are likely to occur in the resin film during the coating operation.

The adhesive composition may contain optional components, such as plasticizers, other curing resin components such as epoxy resins, curing agents, curing accelerators, organic fillers, inorganic fillers, coupling agents, as long as the effects of the invention are not impaired. Solvents, flame retardants, and the like can be appropriately blended.

[Polyimide film/adhesive film]
A polyimide film according to one embodiment of the present invention is obtained by processing the above adhesive polyimide or crosslinked polyimide into a film shape. The polyimide constituting the polyimide film contains 40 mol% or more of diamine residues derived from the dimer diamine composition with respect to all diamine residues, and at least one selected from diamine compounds represented by the general formula (1) It contains in the range of 2 to 40 mol % total diamine residues derived from the seeds.

The polyimide film preferably has a dielectric loss tangent (Tan δ) at 10 GHz measured by a split post dielectric resonator (SPDR) after conditioning for 24 hours under constant temperature and humidity conditions (normal state) of 23 ° C. and 50% RH. It is less than 0.002, more preferably 0.0018 or less, and the dielectric constant (ε) is 3.0 or less, preferably 2.7 or less. If the dielectric loss tangent (Tan δ) and relative permittivity (ε) exceed the above values, when applied to a circuit board, it leads to an increase in dielectric loss, and the transmission path of high frequency signals in the GHz band (eg, 1 to 40 GHz). In this case, problems such as loss of electrical signals are likely to occur.

A preferred form of polyimide film is an adhesive film. The adhesive film preferably contains 70% by weight or more of the resin component as a main component, more preferably 90% by weight or more of the resin component, and most preferably as the entire resin component, the above adhesive polyimide or crosslinked polyimide. It is not particularly limited as long as it contains the film. In addition, the main component of the resin component means a component contained in an amount exceeding 50% by weight with respect to the total resin component. The adhesive film may be a film (sheet) made of adhesive polyimide or crosslinked polyimide. It may be in a state of being laminated on a resin substrate such as a film. The adhesive film can be appropriately blended with optional components such as plasticizers, other curing resin components such as epoxy resins, curing agents, curing accelerators, organic fillers, inorganic fillers, coupling agents, flame retardants, and the like. .

The method for producing the adhesive film of the present embodiment is not particularly limited, but the following methods [1] to [3] can be exemplified.
[1] An arbitrary base material is coated with an adhesive polyimide in the form of a solution (for example, the state of an adhesive composition) to form a coating film, which is dried at a temperature of, for example, 80 to 180 ° C. to form a film. A method of peeling off from the base material as necessary after curing.
[2] A method in which a solution of polyamic acid, which is a precursor of adhesive polyimide, is applied to an arbitrary base material, dried, imidized to form a film, and then peeled off from the base material as necessary.
[3] A method of applying and drying a solution of polyamic acid, which is a precursor of adhesive polyimide, to an arbitrary base material, then peeling off the polyamic acid gel film from the base material and imidizing it to form an adhesive film.
The method of applying the adhesive polyimide solution (or the polyamic acid solution) onto the base material is not particularly limited, and it can be applied, for example, by a comma, die, knife, lip coater, or the like.

Next, a laminate, a metal-clad laminate, a circuit board, and a multilayer circuit board, which are preferred embodiments to which an adhesive film is applied, will be described with specific examples.

[Laminate]
A laminate 100 according to one embodiment of the present invention, for example, as shown in FIG. The adhesive layer 20 is made of the above adhesive film. Note that the laminate 100 may include arbitrary layers other than those described above. Examples of the substrate 10 in the laminate 100 include inorganic material substrates such as copper foil and glass plates, and resin material substrates such as polyimide films, polyamide films, and polyester films. The laminate 100 can be produced according to any one of [1] to [3] of the method for producing an adhesive film, except that it is not separated from the base material 10 . Alternatively, the laminate 100 may be manufactured by separately preparing the substrate 10 and the adhesive film and bonding them together.
Preferred embodiments of the laminate 100 include a coverlay film, a resin-coated copper foil, and the like.

[Coverlay film]
Although not shown, the coverlay film, which is one aspect of the laminate 100, includes a coverlay film material layer as the base material 10 and an adhesive layer laminated on one side of the coverlay film material layer. 20, and the adhesive layer 20 is made of the adhesive film. In addition, the coverlay film may contain arbitrary layers other than the above.

The material of the coverlay film material layer is not particularly limited, but polyimide films such as polyimide resins, polyetherimide resins, and polyamideimide resins, polyamide films, polyester films, and the like can be used, for example. Among these, it is preferable to use a polyimide film having excellent heat resistance. In addition, the coverlay film material may contain a black pigment in order to effectively exhibit light-shielding properties, concealability, and design properties. Optional ingredients such as matte pigments to suppress gloss can be included.

The thickness of the coverlay film material layer is not particularly limited, but is preferably in the range of 5 μm or more and 100 μm or less, for example.
Although the thickness of the adhesive layer 20 is not particularly limited, it is preferably in the range of 10 μm or more and 75 μm or less, for example.

The coverlay film of this embodiment can be manufactured by the method illustrated below.
First, as a first method, polyimide to be the adhesive layer 20 is applied to one side of the coverlay film material layer in a solution state (for example, a varnish containing a solvent is preferable, and an adhesive composition is preferable). After coating, the adhesive layer 20 is formed by drying at a temperature of 80 to 180° C., for example, to form a coverlay film having the coverlay film material layer and the adhesive layer 20 .

As a second method, the polyimide for the adhesive layer 20 is applied in the form of a solution (for example, a varnish containing a solvent, preferably an adhesive composition) on an arbitrary base material. For example, after drying at a temperature of 80 to 180° C., the resin film for the adhesive layer 20 is formed by peeling, and this resin film is bonded to the coverlay film material layer at a temperature of 60 to 220° C., for example. A coverlay film can be formed by thermocompression bonding.

[Copper foil coated with resin]
The resin-coated copper foil, which is another aspect of the laminate 100, is a copper foil with an adhesive layer 20 laminated on at least one side of the copper foil as the base material 10, although not shown. It consists of an agent film. In addition, the resin-coated copper foil of the present embodiment may include arbitrary layers other than those described above.

The thickness of the adhesive layer 20 in the resin-coated copper foil is preferably, for example, within the range of 0.1 to 125 μm, more preferably within the range of 0.3 to 100 μm. If the thickness of the adhesive layer 20 is less than the above lower limit, problems such as insufficient adhesion may occur. On the other hand, if the thickness of the adhesive layer 20 exceeds the above upper limit, problems such as reduced dimensional stability will occur. Moreover, from the viewpoint of lowering the dielectric constant and the dielectric loss tangent, it is preferable to set the thickness of the adhesive layer 20 to 3 μm or more.

The material of the copper foil in the resin-coated copper foil preferably contains copper or a copper alloy as a main component. The thickness of the copper foil is preferably 35 μm or less, more preferably within the range of 5 to 25 μm. The lower limit of the thickness of the copper foil is preferably 5 μm from the viewpoint of production stability and handling. The copper foil may be rolled copper foil or electrolytic copper foil. Moreover, as a copper foil, the copper foil marketed can be used.

The resin-coated copper foil may be prepared, for example, by sputtering a metal onto an adhesive film to form a seed layer, followed by forming a copper layer, for example, by copper plating, or by combining an adhesive film and a copper foil. may be prepared by laminating by a method such as thermocompression bonding. Furthermore, in order to form the adhesive layer 20 on the copper foil with resin, a coating liquid of adhesive polyimide or its precursor is cast, dried to form a coating film, and then subjected to necessary heat treatment. may be prepared using

[Metal clad laminate]
(First aspect)
A metal-clad laminate according to an embodiment of the present invention comprises an insulating resin layer and a metal layer laminated on at least one surface of the insulating resin layer, at least one of the insulating resin layers comprising the above-mentioned It consists of an adhesive film. In addition, the metal-clad laminate of the present embodiment may contain arbitrary layers other than those described above.

(Second aspect)
A metal-clad laminate according to another embodiment of the present invention comprises an insulating resin layer 30, an adhesive layer 20 laminated on at least one surface of the insulating resin layer 30, and A so-called three-layer metal-clad laminate 101 including a metal layer M laminated on an insulating resin layer 30 via an adhesive layer 20, and the adhesive layer 20 is made of the adhesive film. . In addition, the three-layer metal-clad laminate 101 may contain arbitrary layers other than the above. In the three-layer metal-clad laminate 101, the adhesive layer 20 may be provided on one side or both sides of the insulating resin layer 30, and the metal layer M may be provided on one side or both sides of the insulating resin layer 30 with the adhesive layer 20 interposed therebetween. It suffices if it is provided on both sides. That is, the three-layer metal-clad laminate 101 may be a single-sided metal-clad laminate or a double-sided metal-clad laminate. A single-sided FPC or a double-sided FPC can be manufactured by etching the metal layer M of the three-layer metal-clad laminate 101 for wiring circuit processing.

The insulating resin layer 30 in the three-layer metal-clad laminate 101 is not particularly limited as long as it is made of an electrically insulating resin. Examples include fluoroethylene, silicone, ETFE, etc., but it is preferably composed of polyimide. The polyimide layer forming the insulating resin layer 30 may be a single layer or multiple layers, but preferably includes a non-thermoplastic polyimide layer.

The thickness of the insulating resin layer 30 in the three-layer metal-clad laminate 101 is, for example, preferably within the range of 1 to 125 μm, more preferably within the range of 5 to 100 μm. If the thickness of the insulating resin layer 30 is less than the above lower limit, problems such as insufficient electrical insulation may occur. On the other hand, if the thickness of the insulating resin layer 30 exceeds the above upper limit, problems such as warping of the metal-clad laminate will occur.

The thickness of the adhesive layer 20 in the three-layer metal-clad laminate 101 is, for example, preferably within the range of 0.1 to 125 μm, more preferably within the range of 0.3 to 100 μm. In the three-layer metal-clad laminate 101 of the present embodiment, if the thickness of the adhesive layer 20 is less than the above lower limit, problems such as insufficient adhesion may occur. On the other hand, if the thickness of the adhesive layer 20 exceeds the above upper limit, problems such as reduced dimensional stability will occur. From the viewpoint of reducing the dielectric constant and dielectric loss tangent of the entire insulating layer, which is a laminate of the insulating resin layer 30 and the adhesive layer 20, the thickness of the adhesive layer 20 is preferably 3 μm or more.

Further, the ratio of the thickness of the insulating resin layer 30 to the thickness of the adhesive layer 20 (thickness of the insulating resin layer 30/thickness of the adhesive layer 20) is preferably in the range of 0.1 to 3.0, for example. It is more preferably in the range of 0.15 to 2.0. Warping of the three-layer metal-clad laminate 101 can be suppressed by using such a ratio. Moreover, the insulating resin layer 30 may contain a filler if necessary. Examples of fillers include silicon dioxide, aluminum oxide, magnesium oxide, beryllium oxide, boron nitride, aluminum nitride, silicon nitride, aluminum fluoride, calcium fluoride, metal salts of organic phosphinic acids, and the like. These can be used singly or in combination of two or more.

(Third aspect)
A metal-clad laminate according to still another embodiment of the present invention is, for example, as shown in FIG. A tension laminate 102 is shown. The laminated metal-clad laminate 102 includes a first single-sided metal-clad laminate 41, a second single-sided metal-clad laminate 42, a first single-sided metal-clad laminate 41, and a second single-sided metal-clad laminate. and an adhesive layer 20 laminated between 42, the adhesive layer 20 being made of the adhesive film.
Here, the first single-sided metal-clad laminate 41 has a first metal layer M1 and a first insulating resin layer 31 laminated on at least one surface of the first metal layer M1. ing. The second single-sided metal-clad laminate 42 has a second metal layer M2 and a second insulating resin layer 32 laminated on at least one surface of the second metal layer M2. The adhesive layer 20 is arranged so as to contact the first insulating resin layer 31 and the second insulating resin layer 32 . Note that the laminated metal-clad laminate 102 may contain arbitrary layers other than those described above.

The first insulating resin layer 31 and the second insulating resin layer 32 in the laminated metal-clad laminate 102 have the same configuration as the insulating resin layer 30 in the three-layer metal-clad laminate 101 of the second embodiment. good.
For the lamination-type metal-clad laminate 102, a first single-sided metal-clad laminate 41 and a second single-sided metal-clad laminate 42 are prepared, and the first insulating resin layer 31 and the second insulating resin layer 32 are laminated. It can be manufactured by placing an adhesive film between and laminating.

(Fourth aspect)
A metal-clad laminate according to still another embodiment of the present invention, for example, as shown in FIG. and an adhesive layer 20 laminated on the other surface of the insulating resin layer 33, wherein the adhesive layer 20 is the above It consists of an adhesive film. In addition, the metal-clad laminate 103 with an adhesive layer may contain arbitrary layers other than the above.
The insulating resin layer 33 in the adhesive layer-attached metal-clad laminate 103 may have the same configuration as the insulating resin layer 30 in the three-layer metal-clad laminate 101 of the second embodiment.
The metal-clad laminate 103 with an adhesive layer can be manufactured by preparing a single-sided metal-clad laminate having an insulating resin layer 33 and a metal layer M, and bonding an adhesive film to the insulating resin layer 33 side.

In the metal-clad laminate of any one of the first to fourth embodiments illustrated above, the material of the metal layer M (including the first metal layer M1 and the second metal layer M2; the same shall apply hereinafter) includes: Examples include, but are not limited to, copper, stainless steel, iron, nickel, beryllium, aluminum, zinc, indium, silver, gold, tin, zirconium, tantalum, titanium, lead, magnesium, manganese, and alloys thereof. Among these, copper or a copper alloy is particularly preferable. The material of the wiring layer in the circuit board, which will be described later, is also the same as that of the metal layer M.

The thickness of the metal layer M is not particularly limited, but when using a metal foil such as a copper foil, the thickness is preferably 35 μm or less, more preferably in the range of 5 to 25 μm. The lower limit of the thickness of the metal foil is preferably 5 μm from the viewpoint of production stability and handling. When copper foil is used, it may be rolled copper foil or electrolytic copper foil. Moreover, as a copper foil, the copper foil marketed can be used. In addition, the metal foil may be subjected to surface treatment with, for example, siding, aluminum alcoholate, aluminum chelate, silane coupling agent, etc., for the purpose of rust prevention treatment and adhesion strength improvement.

[Circuit board]
(First aspect)
A circuit board according to an embodiment of the present invention is formed by wiring the metal layer of the metal-clad laminate of any one of the above-described embodiments. A circuit board such as an FPC can be manufactured by patterning one or more metal layers of a metal-clad laminate into a wiring layer (conductor circuit layer) by a conventional method. In addition, the circuit board may be provided with a coverlay film that covers the wiring layer.

(Second aspect)
A circuit board 200 according to another embodiment of the present invention includes, for example, a first base material 11 and a wiring layer 50 laminated on at least one surface of the first base material 11, as shown in FIG. and an adhesive layer 20 laminated so as to cover the wiring layer 50 on the wiring layer 50 side surface of the first base material 11, and the adhesive layer 20 is made of the adhesive film. . Note that the circuit board 200 may include arbitrary layers other than those described above.
The first base material 11 in the circuit board 200 may have the same configuration as the insulating resin layer of the metal-clad laminate. The circuit board 200 includes a first base material 11 and a wiring layer 50 laminated on at least one surface of the first base material 11, and an adhesive film is attached to the wiring layer 50 side of the circuit board. can be manufactured by

(Third aspect)
A circuit board 201 according to still another embodiment of the present invention includes, for example, a first base material 11 and a wiring layer 50 laminated on at least one surface of the first base material 11, as shown in FIG. , the adhesive layer 20 laminated so as to cover the wiring layer 50 on the surface of the first base material 11 on the wiring layer 50 side, and the surface of the adhesive layer 20 opposite to the first base material 11 and a laminated second base material 12, and the adhesive layer 20 is made of the adhesive film. Note that the circuit board 201 may include arbitrary layers other than those described above. The first base material 11 and the second base material 12 in the circuit board 201 may have the same structure as the insulating resin layer of the metal-clad laminate.
The circuit board 201 is provided on the wiring layer 50 side of the circuit board provided with the first base material 11 and the wiring layer 50 laminated on at least one surface of the first base material 11 via an adhesive film. It can be manufactured by laminating the second base material 12 .

(Fourth aspect)
A circuit board 202 according to still another embodiment of the present invention includes, for example, a first base material 11 and an adhesive layer laminated on at least one surface of the first base material 11, as shown in FIG. 20, the second base material 12 laminated on the surface of the adhesive layer 20 opposite to the first base material 11, and the adhesive layers of the first base material 11 and the second base material 12 Wiring layers 50 and 50 are laminated on the surface opposite to 20, and the adhesive layer 20 is made of the adhesive film. Note that the circuit board 202 may include arbitrary layers other than those described above. The first base material 11 and the second base material 12 in the circuit board 202 may have the same structure as the insulating resin layer of the metal-clad laminate.
The circuit board 202 includes a first base material 11, a wiring layer 50 laminated on at least one surface of the first base material 11, and a second base material 12. , and a wiring layer 50 laminated on at least one surface of the second base material 12 are prepared, respectively, and the first base material 11 of the first circuit board and the second circuit board are prepared. It can be manufactured by arranging an adhesive film between two circuit boards and the second base material 12 and laminating them together.

[Multilayer circuit board]
A multilayer circuit board according to one embodiment of the present invention includes a laminate in which a plurality of insulating resin layers are laminated, and one or more wiring layers embedded in the laminate, and comprises a plurality of insulating resin layers. At least one or more of the resin layers is formed of an adhesive layer 20 that has adhesiveness and covers the wiring layer, and the adhesive layer 20 is made of the adhesive film. In addition, the multilayer circuit board of the present embodiment may include arbitrary layers other than the above.
For example, as shown in FIG. 8, the multilayer circuit board 203 of the present embodiment has at least two insulating resin layers 34 and at least two wiring layers 50. At least one of the wiring layers 50 The layers are covered with an adhesive layer 20 . The adhesive layer 20 covering the wiring layer 50 may partially cover the surface of the wiring layer 50 or may cover the entire surface of the wiring layer 50 . Moreover, the multilayer circuit board 203 may optionally have a wiring layer 50 exposed on the surface of the multilayer circuit board 203 . Moreover, it may have an interlayer connection electrode (via electrode) in contact with the wiring layer 50 . The wiring layer 50 is formed by forming a conductor circuit in a predetermined pattern on one side or both sides of the insulating resin layer 34 . The conductive circuit may be patterned on the surface of the insulating resin layer 34, or may be patterned in a damascene (embedded) manner. The insulating resin layer 34 in the multilayer circuit board 203 may have the same structure as the insulating resin layer in the metal-clad laminate.

Since the circuit board and the multilayer circuit board of each of the above embodiments are provided with the adhesive layer 20 containing adhesive polyimide, transmission loss can be reduced even in high-frequency transmission.

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

[Method for measuring amine value]
About 2 g of the dimer diamine composition was weighed into a 200-250 mL Erlenmeyer flask, phenolphthalein was used as an indicator, and a 0.1 mol/L ethanolic potassium hydroxide solution was added dropwise until the solution exhibited a light pink color. , in about 100 mL of neutralized butanol. Add 3 to 7 drops of phenolphthalein solution thereto, and titrate with stirring with 0.1 mol/L ethanolic potassium hydroxide solution until the sample solution turns pale pink. Five drops of bromophenol blue solution are added thereto, and titration is performed with stirring with a 0.2 mol/L hydrochloric acid/isopropanol solution until the sample solution turns yellow.
The amine value is calculated by the following formula (1).
Amine value = {(V ₂ ×C ₂ )−(V ₁ ×C ₁ )}×M _KOH /m (1)
Here, the amine value is a value expressed in mg-KOH/g, and M _KOH is the molecular weight of potassium hydroxide, 56.1. Further, V and C are the volume and concentration of the solution used for titration, respectively, and the subscripts 1 and 2 are 0.1 mol/L ethanolic potassium hydroxide solution and 0.2 mol/L hydrochloric acid/isopropanol solution, respectively. represents Additionally, m is the sample weight in grams.

[Measurement of weight average molecular weight (Mw) and number average molecular weight (Mn) of polyimide]
The weight average molecular weight was measured by gel permeation chromatography (manufactured by Tosoh Corporation, using HLC-8220GPC). Polystyrene was used as a standard substance, and tetrahydrofuran (THF) was used as a developing solvent.

[Calculation of aromatic ring ratio of dimer diamine composition]
The aromatic ring ratio of the dimer diamine composition was calculated by the following procedure. First, about 50 μl of the dimer diamine composition was dissolved in 550 μl of THF-d8 to prepare a sample. Liquid 1H-NMR measurement was performed on the prepared sample at room temperature using an FT-NMR device (JNM-ECA400 manufactured by JEOL). The integrated value of the 1H peak derived from the _CH2 group directly connected to the _NH2 group found at 2.6-2.9 ppm is compared to the integrated value of the 1H peak derived from the aromatic ring found at 6.6-7.2 ppm. From the ratio, the ratio of aromatic rings was calculated according to the following formula.
Aromatic ring ratio [mol%] = (Z / Y) × 100
[Here, Y means the integrated value of the 1H peak at 2.6-2.9 ppm and Z means the integrated value of the 1H peak (derived from the aromatic ring) at 6.6-7.2 ppm. ]

[Calculation of area percent of GPC and chromatogram]
(a) a dimer diamine (b) a monoamine compound obtained by substituting a primary aminomethyl group or an amino group for the terminal carboxylic acid group of a monobasic acid compound having 10 to 40 carbon atoms (c) 41 carbon atoms Amine compounds obtained by substituting a primary aminomethyl group or an amino group for the terminal carboxylic acid group of a polybasic acid compound having a hydrocarbon group within the range of ∼80 (excluding the dimer diamine)

For GPC, 20 mg of the dimer diamine composition was pretreated with 200 μL of acetic anhydride, 200 μL of pyridine and 2 mL of THF, and 100 mg of the solution was diluted with 10 mL of THF (containing 1000 ppm of cyclohexanone) to prepare samples. The prepared sample was manufactured by Tosoh Corporation, trade name; using HLC-8220GPC, column: TSK-gel G2000HXL, G1000HXL, flow rate: 1 mL / min, column (oven) temperature: 40 ° C., injection volume: 50 μL. measured in In addition, cyclohexanone was treated as a standard substance for correction of effluent time.

At this time, the peak top of the main peak of cyclohexanone is adjusted so that the retention time is 27 minutes to 31 minutes, and the peak end is 2 minutes from the peak start of the main peak of cyclohexanone, and the peak of cyclohexanone is excluded. Each of the above components (a ) ~ (c) as
(a) the component represented by the main peak;
(b) A component represented by a GPC peak detected at a time later than the minimum value on the time side with a slow retention time in the main peak;
(c) A component represented by a GPC peak detected at an earlier time than the minimum value on the time side where the retention time in the main peak is early;
detected.

[Measurement of dielectric constant and dielectric loss tangent]
Using a vector network analyzer (manufactured by Agilent, trade name: vector network analyzer E8363C) and an SPDR resonator, the resin sheet was left for 24 hours under conditions of temperature: 23 ° C. and humidity: 50%. Dielectric constant (ε) and dielectric loss tangent (Tan δ) were measured.

[Glass transition temperature (Tg)]
The glass transition temperature (Tg) was measured by using a thermomechanical analyzer (TMA: manufactured by Netsch, trade name: TMA4000SA) on a resin sheet with a size of 5 mm × 20 mm from 0 ° C. to 300 ° C. at a heating rate of 5 ° C./ Measurements were made in minutes. The temperature at which the elongation becomes an inflection point when the temperature is raised was defined as the glass transition temperature.

[Tensile modulus]
Tensile modulus was measured by the following procedure. First, a test piece (width 12.7 mm×length 127 mm) was produced from a resin sheet using a tension tester (manufactured by Orientec, trade name: Tensilon). Using this test piece, a tensile test was performed at 50 mm/min to determine the tensile modulus at 25°C.

[Warpage evaluation method]
The evaluation of warpage was performed by the following method. A 25 μm thick polyimide film (manufactured by Toray DuPont, trade name: Kapton 100EN) or a 12 μm copper foil is coated with a polyimide solution so that the thickness after drying is 25 μm, and a test piece is prepared. was made. In this state, place the polyimide film or copper foil on the bottom surface, measure the average warped height of the four corners of the test piece, 5 mm or less is "good", more than 5 mm is "fail" bottom.

The abbreviations used in the examples represent the following compounds.
BTDA: 3,3',4,4'-benzophenonetetracarboxylic dianhydride BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride ODPA: 4,4'-oxydiphthalic anhydride 6FDA : 4,4'-(Hexafluoroisopropylidene) diphthalic anhydride DDA: Aliphatic diamine having 36 carbon atoms (manufactured by Croda Japan Co., Ltd., trade name; purified product of PRIAMINE 1075, amine value: 210 mgKOH/g, cyclic structure and Mixture of chain-structured dimer diamines, component (a): 97.9%, component (b): 0.3%, component (c): 1.8%, aromatic ring ratio: 8.2 mol%)
m-TB: 2,2'-dimethyl-4,4'-diaminobiphenyl TFMB: 2,2'-ditrifluoromethylbenzidine VAB: 2,2'-divinyl-4,4'-diaminobiphenyl APB: 1,3 -bis(3-aminophenoxy)benzene BAPP: 2,2-bis[4-(4-aminophenoxy)phenyl]propane N-12: dodecanedioic acid dihydrazide NMP: N-methyl-2-pyrrolidone OP935: of phosphinic acid Aluminum salt (manufactured by Clariant, trade name: Exolit OP935, aluminum diethylphosphinate, phosphorus content 23%, average particle size 2 μm)
In the above DDA, "%" of the a component, the b component and the c component means the area percentage of the chromatogram in GPC measurement. Further, the molecular weight of DDA was calculated by the following formula.
Molecular weight = 56.1 x 2 x 1000/amine value

[Example 1]
In a 1000 ml separable flask, 46.59 g BTDA (0.1446 mol), 68.83.95 g DDA (0.1288 mol), 4.58 g TFMB (0.0143 mol), 168 g NMP and 112 g of xylene was added and mixed well at 40° C. for 1 hour to prepare a polyamic acid solution. The polyamic acid solution was heated to 190 ° C., heated and stirred for 5 hours, and 98 g of xylene was added to complete imidation. An average molecular weight of 20,339) was prepared.

[Examples 2 to 13]
Polyimide solutions 2 to 13 were prepared in the same manner as in Example 1, except that the raw material compositions shown in Table 1 or Table 2 were used.

[Synthesis Examples 1 to 5]
Polyimide solutions 14 to 18 were prepared in the same manner as in Example 1, except that the raw material compositions shown in Table 2 were used.

[Comparative Example 1]
Polyimide solution 19 was prepared in the same manner as in Example 1, except that the raw material composition shown in Table 2 was used.

[Example 14]
A polyimide solution 1 is applied to one side of a release PET film 1 (manufactured by Higashiyama Film Co., Ltd., trade name: HY-S05, length x width x thickness = 200 mm x 300 mm x 25 μm), and dried at 120 ° C. for 10 minutes. By peeling the adhesive layer from the release PET film 1, an adhesive film 14 having a thickness of 25 μm was obtained. Various evaluation results of the adhesive film 14 are as follows.
ε; 2.7, Tan δ; 0.0016, Tg; 37°C, tensile modulus; 0.8 GPa

[Examples 15-26]
Adhesive films 15-26 were obtained in the same manner as in Example 14, except that polyimide solutions 2-13 were used. Various characteristic evaluation results are shown in Table 3.

[Comparative Examples 2 to 6]
Adhesive films 27-31 were obtained in the same manner as in Example 14, except that polyimide solutions 14-18 were used. Various characteristic evaluation results are shown in Table 3.

[Example 27]
100 g of polyimide solution 1 (30 g as solid content) was blended with 1.1 g of N-12 (0.004 mol), diluted by adding 7.5 g of OP935 and 14.0 g of xylene, and further stirred for 1 hour. By doing so, an adhesive composition 27 was prepared.

[Examples 28-37]
Adhesive compositions 28-37 were prepared in the same manner as in Example 27, except polyimide solutions 2-11 were used.

[Example 38]
The adhesive composition 27 is applied to one side of the release PET film 1 and dried at 80° C. for 15 minutes to obtain a resin sheet 38 having an adhesive layer thickness of 25 μm. An adhesive film 38 having a thickness of 25 μm was obtained by peeling from the substrate.

[Examples 39-48]
Resin sheets 39 to 48 were obtained in the same manner as in Example 38, except that adhesive compositions 28 to 37 were used, and then adhesive films 39 to 48 were obtained.

[Example 49]
Adhesive composition 27 was applied to one side of polyimide film 1 (manufactured by Toray DuPont, trade name: Kapton 50EN, ε = 3.6, tan δ = 0.0084, length x width x thickness = 200 mm x 300 mm x 12 µm). It was applied and dried at 80° C. for 15 minutes to obtain a coverlay film 49 having an adhesive layer thickness of 25 μm. The warpage state of the obtained coverlay film 49 was "good".

[Example 50]
The release PET film 1 was laminated so as to be in contact with the adhesive layer side of the coverlay film 49, and pressure-bonded using a vacuum laminator at a temperature of 160° C. and a pressure of 0.8 MPa for 2 minutes. After that, the adhesive composition 27 is applied to the polyimide film 1 side of the cover lay film 49 with the release PET film 1 pressure-bonded to the adhesive layer side so that the thickness after drying becomes 25 μm, and dried at 80° C. for 15 minutes. did Then, the adhesive composition 27 is laminated so that the release PET film 1 is in contact with the surface to which the adhesive composition 27 has been applied and dried. A polyimide adhesive laminate 50 with adhesive was obtained.

[Example 51]
The adhesive composition 27 was applied to one side of an electrolytic copper foil having a thickness of 12 μm and dried at 80° C. for 15 minutes to obtain a resin-coated copper foil 51 having an adhesive layer thickness of 25 μm. The warping state of the obtained resin-coated copper foil 51 was "good".

[Example 52]
The adhesive composition 27 was applied to one side of an electrolytic copper foil having a thickness of 12 μm and dried at 80° C. for 30 minutes to obtain a resin-coated copper foil 52 having an adhesive layer having a thickness of 50 μm. The warping state of the obtained resin-coated copper foil 52 was "good".

[Example 53]
An adhesive composition 27 was further applied to the surface of the adhesive layer of the resin-coated copper foil 52 and dried at 80° C. for 30 minutes to obtain a resin-coated copper foil 53 having a total adhesive layer thickness of 100 μm. . The warping state of the obtained resin-coated copper foil 53 was "good".

[Example 54]
The adhesive composition 27 is applied to one side of the release PET film 1, dried at 80° C. for 30 minutes, and the adhesive layer is peeled off from the release PET film 1, thereby forming an adhesive film 54 having a thickness of 50 μm. got

[Example 55]
Adhesive film 54, polyimide film 2 (manufactured by DuPont, trade name: Kapton 100-EN, thickness 25 μm, ε = 3.6, tan δ = 0.0084), adhesive film 54 on an electrolytic copper foil having a thickness of 12 μm. And an electrodeposited copper foil with a thickness of 12 μm is sequentially laminated and crimped for 2 minutes at a temperature of 160 ° C. and a pressure of 0.8 MPa using a vacuum laminator, then heated from room temperature to 160 ° C. and heat-treated at 160 ° C. for 4 hours. A copper clad laminate 55 was obtained.

[Example 56]
A cover lay film 49 was laminated on an electrolytic copper foil having a thickness of 12 μm so that the adhesive layer side of the cover lay film 49 was in contact with the copper foil, and was crimped using a vacuum laminator at a temperature of 160° C. and a pressure of 0.8 MPa for 2 minutes. C. and heat-treated at 160.degree. C. for 2 hours to obtain a copper-clad laminate 56.

[Example 57]
An adhesive film 38 is laminated on a rolled copper foil having a thickness of 12 μm, and then a coverlay film 49 is laminated so that the polyimide film 1 side of the coverlay film 49 is in contact with the adhesive film 38 . Rolled copper foils with a thickness of 12 μm are sequentially laminated and pressed using a vacuum laminator at a temperature of 160 ° C. and a pressure of 0.8 MPa for 2 minutes. A tension laminate 57 was obtained.

[Example 58]
Two resin-coated copper foils 53 are prepared, and a polyimide film 3 (manufactured by DuPont, trade name: Kapton 200-EN, thickness 50 μm, ε=3.6, tan δ = 0.0084), and pressed for 5 minutes at a temperature of 160 ° C. and a pressure of 0.8 MPa using a vacuum laminator, then heated from room temperature to 160 ° C. and heat treated at 160 ° C. for 4 hours. , a copper clad laminate 58 was obtained.

[Example 59]
Adhesive composition 27 is applied to the polyimide side of single-sided copper-clad laminate 1 (manufactured by Nippon Steel Chemical & Materials, trade name; Espanex MC12-25-00UEM, length x width x thickness = 200 mm x 300 mm x 25 μm). Then, it was dried at 80° C. for 30 minutes to obtain an adhesive-attached copper-clad laminate 59 having an adhesive layer thickness of 50 μm. The resin layer side of the single-sided copper-clad laminate 1 is laminated to the adhesive layer side of the adhesive-attached copper-clad laminate 59, and pressed using a small precision press at a temperature of 160° C. and a pressure of 4.0 MPa. After pressing for 120 minutes, a copper-clad laminate 59 was obtained.

[Example 60]
Two adhesive-attached copper-clad laminates 59 are laminated so that the surfaces on the adhesive layer side are in contact with each other, and are pressed using a small precision press at a temperature of 160° C. and a pressure of 4.0 MPa for 120 minutes to form a copper-clad laminate. A plate 60 was obtained.

[Example 61]
An adhesive film 54 is laminated on the resin layer side of the single-sided copper-clad laminate 1, and further laminated thereon so that the resin layer side of the single-sided copper-clad laminate 1 is in contact with the adhesive film 54, and a small precision press is used. was pressed for 120 minutes at a temperature of 160° C. and a pressure of 4.0 MPa to obtain a copper-clad laminate 61 .

[Example 62]
The adhesive composition 27 is applied to one side of the release PET film 1, dried at 80° C. for 15 minutes, and the adhesive layer is peeled off from the release PET film 1, thereby forming an adhesive film 62 having a thickness of 15 μm. got

[Example 63]
An adhesive film 62 is laminated on the resin layer side of the single-sided copper-clad laminate 1, and further laminated thereon so that the resin layer side of the single-sided copper-clad laminate 1 is in contact with the adhesive film 62, followed by a small precision press. was pressed for 120 minutes at a temperature of 160° C. and a pressure of 4.0 MPa to obtain a copper-clad laminate 62 .

[Example 64]
A double-sided copper-clad laminate 2 (manufactured by Nippon Steel Chemical & Materials Co., Ltd., trade name: Espanex MB12-25-00UEG) was prepared, and the copper foil on one side was subjected to circuit processing by etching to form a conductor circuit layer. A wiring board 64A was obtained.

The copper foil on one surface of a separately prepared double-sided copper-clad laminate 2 was removed by etching to obtain a copper-clad laminate 64B.

The adhesive film 38 was sandwiched between the conductor circuit layer side surface of the wiring board 64A and the resin layer side surface of the copper-clad laminate 64B, and in a laminated state, the temperature was 160° C. and the pressure was 4.0 MPa for 120 minutes. A multilayer circuit board 64 was obtained by thermocompression bonding.

[Example 65]
A liquid crystal polymer film (manufactured by Kuraray Co., Ltd., trade name: CT-Z, thickness: 50 μm, CTE: 18 ppm/K, heat distortion temperature: 300° C., ε=3.40, tan δ=0.0022) was used as an insulating substrate. Then, a copper-clad laminate 65 having 18 μm-thick electrolytic copper foil provided on both sides is prepared, and the copper foil on one side is subjected to circuit processing by etching to obtain a wiring board 65A having a conductor circuit layer formed thereon. rice field.

The copper foil on one side of the separately prepared copper-clad laminate 65 was removed by etching to obtain a copper-clad laminate 65B.

The adhesive film 54 was sandwiched between the conductive circuit layer side surface of the wiring board 65A and the insulating substrate layer side surface of the copper-clad laminate 65B, and in a laminated state, the temperature was 160° C. and the pressure was 4.0 MPa. , and thermocompression bonding for 120 minutes to obtain a multilayer circuit board 65 .

Although the embodiments of the present invention have been described above in detail for the purpose of illustration, the present invention is not limited to the above embodiments and various modifications are possible.

DESCRIPTION OF SYMBOLS 10... Base material 11... 1st base material 12... 2nd base material 20... Adhesive bond layer 30, 33, 34... Insulating resin layer 31... First insulating resin layer 32... Second 41 First single-sided metal-clad laminate 42 Second single-sided metal-clad laminate 50 Wiring layer M Metal layer M1 First metal layer M2 Second Metal layer 100 Laminate 101 Three-layer metal-clad laminate 102 Laminated metal-clad laminate 103 Metal-clad laminate with adhesive layer 200, 201, 202 Circuit board 203 Multi-layer circuit board

Claims (20)

A thermoplastic polyimide containing an acid dianhydride residue derived from an acid dianhydride component and a diamine residue derived from a diamine component,
40 mol of diamine residues derived from a dimer-diamine composition containing dimer-diamine as a main component in which two terminal carboxylic acid groups of a dimer acid are substituted with primary aminomethyl groups or amino groups with respect to all diamine residues % or more and contains a total of 2 to 40 mol % of diamine residues derived from a diamine compound represented by the following general formula (1).

[In the formula (1), the linking group A represents a single bond or a divalent group selected from -COO- or -CONH-, and the substituent E is independently a hydrogen atom, even if substituted with a halogen atom a monovalent alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a vinyl group, an acrylic group, a methacrylic group or an allyl group; m is an integer of 1 to 2; p and q are Each independently represents an integer from 0 to 4. ] 2. The thermoplastic polyimide according to claim 1, having a weight average molecular weight (Mw) in the range of 5,000 to 200,000. 3. The thermoplastic polyimide according to claim 1, which contains 10 mol % or more of acid dianhydride residues derived from benzophenonetetracarboxylic acid dianhydride relative to all acid dianhydride residues. 3. The thermoplastic polyimide according to claim 1, wherein the diamine residue contains a diamine residue derived from a diamine compound having a substituent having a carbon-carbon double bond. A ketone group contained in the thermoplastic polyimide according to claim 3 and an amino group of an amino compound having at least two primary amino groups as functional groups form a crosslinked structure by a C=N bond. Crosslinked polyimide. 5. A crosslinked polyimide in which the carbon-carbon double bonds contained in the thermoplastic polyimide according to claim 4 form a crosslinked structure. An adhesive film comprising the thermoplastic polyimide according to any one of claims 1 to 4 or the crosslinked polyimide according to claim 5 or 6. The dielectric loss tangent (Tan δ) at 10 GHz measured by a split post dielectric resonator (SPDR) is less than 0.002 after conditioning for 24 hours under constant temperature and humidity conditions (normal state) of 23°C and 50% RH. The adhesive film of Claim 7. A laminate having a substrate and an adhesive layer laminated on at least one surface of the substrate,
A laminate, wherein the adhesive layer comprises the adhesive film according to claim 7 or 8. A coverlay film having a coverlay film material layer and an adhesive layer laminated on the coverlay film material layer,
A coverlay film, wherein the adhesive layer comprises the adhesive film of claim 7 or 8. A resin-coated copper foil obtained by laminating an adhesive layer and a copper foil,
A resin-coated copper foil, wherein the adhesive layer comprises the adhesive film according to claim 7 or 8. A metal-clad laminate having an insulating resin layer and a metal layer laminated on at least one surface of the insulating resin layer,
A metal-clad laminate, wherein at least one of said insulating resin layers comprises the adhesive film according to claim 7 or 8. A metal-clad laminate having an insulating resin layer, an adhesive layer laminated on at least one surface of the insulating resin layer, and a metal layer laminated on the insulating resin layer via the adhesive layer. hand,
A metal-clad laminate, wherein the adhesive layer comprises the adhesive film according to claim 7 or 8. a first single-sided metal-clad laminate having a first metal layer and a first insulating resin layer laminated on at least one surface of the first metal layer;
a second single-sided metal-clad laminate having a second metal layer and a second insulating resin layer laminated on at least one surface of the second metal layer;
arranged to abut on the first insulating resin layer and the second insulating resin layer and laminated between the first single-sided metal-clad laminate and the second single-sided metal-clad laminate A metal-clad laminate comprising an adhesive layer,
A metal-clad laminate, wherein the adhesive layer comprises the adhesive film according to claim 7 or 8. A single-sided metal-clad laminate having an insulating resin layer and a metal layer laminated on one side of the insulating resin layer; and an adhesive layer laminated on the other side of the insulating resin layer. 9. A metal-clad laminate, wherein said adhesive layer comprises the adhesive film of claim 7 or 8. A circuit board obtained by wiring the metal layer of the metal-clad laminate according to any one of claims 12 to 15. A first base material, a wiring layer laminated on at least one surface of the first base material, and a wiring layer laminated on a surface of the first base material on the wiring layer side so as to cover the wiring layer A circuit board comprising an adhesive layer,
A circuit board, wherein the adhesive layer comprises the adhesive film according to claim 7 or 8. A first base material, a wiring layer laminated on at least one surface of the first base material, and a wiring layer laminated on a surface of the first base material on the wiring layer side so as to cover the wiring layer A circuit board comprising an adhesive layer and a second substrate laminated on a surface of the adhesive layer opposite to the first substrate,
A circuit board, wherein the adhesive layer comprises the adhesive film according to claim 7 or 8. A first substrate, an adhesive layer laminated on at least one surface of the first substrate, and a second substrate laminated on the surface of the adhesive layer opposite to the first substrate and a wiring layer laminated on each of the surfaces of the first base material and the second base material opposite to the adhesive layer,
A circuit board, wherein the adhesive layer comprises the adhesive film according to claim 7 or 8. A multilayer circuit board comprising a laminate including a plurality of laminated insulating resin layers and at least one or more wiring layers embedded in the laminate,
At least one or more of the plurality of insulating resin layers is formed of an adhesive layer that has adhesiveness and covers the wiring layer,
A multilayer circuit board, wherein the adhesive layer comprises the adhesive film according to claim 7 or 8.

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