CN115884996A

CN115884996A - Film

Info

Publication number: CN115884996A
Application number: CN202180050813.XA
Authority: CN
Inventors: 小沼勇辅; 西冈宏司
Original assignee: Sumitomo Chemical Co Ltd
Current assignee: Sumitomo Chemical Co Ltd
Priority date: 2020-08-31
Filing date: 2021-08-31
Publication date: 2023-03-31
Also published as: JP2022041944A; WO2022045359A1; KR20230059170A; TW202219176A

Abstract

The invention provides a film with excellent water absorption resistance and a composition capable of forming the film. A film comprising a polyimide resin (A) and a particulate polymer (B), having a haze of 75% or less, and having a reflection measured by a specular reflection removal methodLightness L of light ^* The film has 37 or less on both sides.

Description

Film

Technical Field

Relates to a film that can be used as a substrate material for printed circuit boards and antenna boards that can be used in high-frequency bands, and a composition capable of forming the film.

Background

With the widespread use of fifth-generation mobile communication systems called 5G, printed wiring boards and the like that can be used for printed circuits and antennas that can cope with high frequency bands have been demanded. However, in the high frequency band, the transmission loss due to the substrate material significantly affects, and therefore, the selection of a substrate material capable of suppressing the transmission loss is important. For example, a copper clad laminate called CCL has a structure in which copper foils are laminated on both surfaces of a resin layer with an adhesive interposed therebetween. Since the transmission loss of the CCL can be suppressed by reducing the dielectric loss, particularly the dielectric loss tangent and the relative permittivity, of the resin layer serving as the transmission path, a film having a low dielectric loss tangent has been studied. For example, patent document 1 discloses a low dielectric resin composition containing a resin (a) such as a polyimide resin and a cyclic olefin (co) polymer (B), and a film having a low dielectric loss tangent formed from the composition. However, even in the film formed of the low dielectric resin composition described in patent document 1, the decrease in the dielectric loss tangent is not necessarily sufficient.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2017-125176

Disclosure of Invention

Problems to be solved by the invention

The inventors of the present application have studied the reduction of the dielectric loss tangent, and as a result, have found that a film formed from the low dielectric resin composition described in patent document 1 may have insufficient water absorption resistance.

Accordingly, an object of the present invention is to provide a film having excellent water absorption resistance and a composition capable of forming the film.

Means for solving the problems

The inventors of the present application have conducted intensive studies to solve the above problems, and as a result, have surprisingly found thatIt was found that, in a film comprising a polyimide resin (A) and a particulate polymer (B), the lightness L of reflected light of the film measured by a regular reflection light removal method ^* When both surfaces of the film were 37 or less, the water absorption resistance of the film could be improved, and the present invention was completed.

That is, the present invention includes the following preferred embodiments.

A film comprising a polyimide resin (A) and a particulate polymer (B), having a haze of 75% or less, and having a lightness L of reflected light measured by a specular reflection light removal method ^* The film has 37 or less on both sides.

A film comprising a polyimide resin (A) and a particulate polymer (B), wherein the film has a haze of more than 75% and a lightness L of reflected light measured by a regular reflection light removal method ^* The film has 80 or less on both sides.

[ 3] the film according to [ 1] or [ 2], wherein the distance between the HSP values of the polyimide resin (A) and the polymer (B) is 6 or more.

[ 4] the film according to any one of [ 1] to [ 3], wherein the average primary particle diameter of the particulate polymer (B) is 15 μm or less.

[ 5] the film according to any one of [ 1] to [ 4], wherein the content of the particulate polymer (B) is 5 to 50% by mass based on the total mass of the polyimide resin (A) and the particulate polymer (B).

The film according to any one of [ 1] to [ 5], wherein the polymer (B) is at least 1 polymer selected from the group consisting of olefin polymers, polyimide polymers, fluorine polymers, silicone polymers, liquid crystal polymers, aramid polymers, styrene polymers and ether polymers.

[ 7] the film according to any one of [ 1] to [ 6], wherein the polymer (B) is a cycloolefin polymer.

The film according to any one of [ 1] to [ 7], wherein at least one of the glass transition temperature and the melting point of the polymer (B) is 100 ℃ or higher.

[ 9] the film according to [ 7] or [ 8], wherein the cycloolefin-based polymer contains a monomer unit (1) derived from a cycloolefin represented by the formula (I).

[ chemical formula 1]

[ in the formula (I), m represents an integer of 0 or more, R ⁷ ～R ¹⁸ Independently of each other, a hydrogen atom, a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms, in R ¹¹ ～R ¹⁴ When there are plural, they may be the same or different, and R ¹⁶ And R ¹⁷ May be bonded to each other and form a ring together with the carbon atom to which they are bonded]

[ 10] A composition comprising a polyimide resin (A), a particulate polymer (B) and a solvent,

the solvent comprises a 1 st solvent and a 2 nd solvent, and the distance between the HSP value of the 2 nd solvent and the particulate polymer (B) is 8.5 or more.

Effects of the invention

According to the present invention, a film having excellent water absorption resistance and a composition capable of forming the film can be provided.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail. The scope of the present invention is not limited to the embodiments described herein, and various modifications can be made without departing from the scope of the present invention.

[ film ]

The film of the present invention has a lightness L of reflected light measured by a specular reflection light removal method when the film contains a polyimide resin (a) and a particulate polymer (B) and has a haze of 75% or less ^* (hereinafter, may be simply referred to as "lightness") is 37 or less on both surfaces of the film, and when the film contains the polyimide resin (A) and the particulate polymer (B) and has a haze of more than 75%, the film has a reflection measured by a specular reflection light removal methodLightness L of light ^* The number of both surfaces of the film is 80 or less.

The inventors of the present application have studied the water absorption resistance of the film, and as a result, have unexpectedly obtained the following findings: the water absorption resistance of the film varies depending on the relationship between the haze and the brightness of the film. Therefore, the inventors of the present application have further studied with attention paid to the lightness of the film, and found that: when the brightness of the film having a haze of 75% or less is 37 or less on both sides of the film, a film having excellent water absorption resistance can be obtained; and, if the brightness of the film having a haze of more than 75% is 80 or less on both sides of the film, a film having excellent water absorption resistance can be obtained.

On the other hand, if the brightness of at least one surface of the film having a haze of 75% or less is greater than 37, the water absorption resistance of the film tends to decrease. When the brightness of at least one surface of the film having a haze of more than 75% is more than 80, the water absorption resistance of the film tends to decrease. When the film absorbs water, the dielectric properties tend to be lowered.

In one embodiment of the present invention, the brightness of the film having a haze of 75% or less is preferably 36.5 or less, more preferably 36 or less, further preferably 34 or less, and particularly preferably 32 or less on both surfaces thereof. When the lightness is not more than the upper limit, the water absorption resistance of the film is easily improved. The lightness of the film is preferably 10 or more, more preferably 20 or more, and further preferably 25 or more on both sides thereof. When the lightness is not less than the lower limit, for example, a roll mark is less likely to occur when the film is stored in a roll. The lightness of the reflected light measured by specular reflection light removal (SCE) in the present invention can be measured by a spectrocolorimeter, for example, by the method described in examples. The haze of the film can be measured using a haze meter according to JIS K7136, and can be measured, for example, by the method described in examples.

In another embodiment of the present invention, the brightness of the film having a haze of more than 75% is preferably 78.5 or less, more preferably 78 or less, further preferably 76 or less, further more preferably 73 or less, and particularly preferably 72 or less on both surfaces thereof. When the lightness is not more than the upper limit, the water absorption resistance of the film is easily improved. The lightness of the film is preferably 30 or more, more preferably 40 or more, further preferably 48 or more, further more preferably 50 or more, and particularly preferably 55 or more on both sides thereof. When the lightness is not less than the lower limit, for example, a roll mark is less likely to occur when the film is stored in a roll.

The brightness of the film can be adjusted by appropriately adjusting the composition of the film, for example, the types of the structural units constituting the polyimide resin (a) and/or the polymer (B) contained in the film, the composition ratios thereof, the molecular weights thereof, the content of the particulate polymer (B) in the film, the particle diameters thereof, the film production conditions, and the like. For example, the brightness of the film can be adjusted to fall within the above range by selecting the type of the polymer (B), the type of the structural unit constituting the polyimide resin (a) and/or the polymer (B), the composition ratio thereof, the content of the particulate polymer (B), the particle diameter thereof, and the method for producing the film, which are described as preferable embodiments in the description below. In particular, when the film is formed by a preferred production method described later, the brightness of the film can be easily adjusted to fall within the above range. In the present specification, unless otherwise specified, "particle diameter" means a mean primary particle diameter and/or a median particle diameter of the particulate polymer (B).

< Polymer (B) >

The polymer (B) is a polymer different from the polyimide resin (a). When the polymer (B) is a polyimide-based resin, it may be any polyimide-based resin that is different from the polyimide-based resin (a), for example, different in the type of monomer unit constituting the resin, the content thereof, and the like.

The polymer (B) is not particularly limited, and examples thereof include olefin polymers, polyimide polymers, fluorine polymers, silicone polymers, liquid crystal polymers, aramid polymers, styrene polymers, and ether polymers. The polymer (B) may be used alone or in combination of two or more. When these are used as the polymer (B), the particle diameter of the polymer (B) is easily decreased, and the dispersibility is easily improved. Further, when these are used as the polymer (B), the lightness and the linear expansion coefficient (hereinafter, sometimes referred to as CTE) of the obtained film are easily reduced, and the dielectric properties and the water absorption resistance of the film are easily improved. Among them, at least 1 polymer selected from the group consisting of olefin polymers, polyimide polymers, fluorine polymers, liquid crystal polymers, styrene polymers, and ether polymers is preferable, olefin polymers are more preferable, at least 1 polymer selected from the group consisting of polyethylene, high density polyethylene, polypropylene, polymethylpentene, and cycloolefin polymers is even more preferable, and cycloolefin polymers are particularly preferable. In the present specification, the dielectric properties include dielectric loss, relative permittivity and dielectric loss tangent, and the dielectric properties are increased or improved, and for example, the dielectric loss, relative permittivity and/or dielectric loss tangent are decreased.

In a preferred embodiment of the present invention, the cycloolefin-based polymer preferably contains a monomer unit (I) derived from a cycloolefin represented by the formula (I).

[ chemical formula 2]

[ in the formula (I), m represents an integer of 0 or more,

R ⁷ ～R ¹⁸ independently of each other, a hydrogen atom, a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms, in R ¹¹ ～R ¹⁴ When a plurality of the compounds exist, they may be the same or different independently of each other, and R is ¹⁶ And R ¹⁷ May be bonded to each other and form a ring together with the carbon atom to which they are bonded]

Hereinafter, the "particle diameter of the particulate polymer (B)" may be simply referred to as "particle diameter".

In the formula (I), m is an integer of 0 or more. From the viewpoint of easy reduction in particle size and CTE, easy improvement in water absorption resistance and heat resistance of the film, and easy availability, the upper limit of m is preferably an integer of 3 or less, more preferably an integer of 2 or less, and still more preferably an integer of 1 or less.

With respect to as R ⁷ ～R ¹⁸ Examples of the hydrocarbyl group having 1 to 20 carbon atoms which is a member of the substituent(s) include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, and a dodecyl group; aryl groups such as phenyl, tolyl, and naphthyl; aralkyl groups such as benzyl and phenethyl; and groups obtained by substituting a part of hydrogen atoms of the alkyl group, the aryl group, and the aralkyl group with a halogen atom. Among them, an alkyl group, an aryl group, or an aralkyl group is preferable from the viewpoint of easily improving the water absorption resistance, dielectric characteristics, and heat resistance of the film and easily lowering the CTE of the film. I.e. R ⁷ ～R ¹⁸ Preferably a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or an aralkyl group having 7 to 20 carbon atoms, and more preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

Examples of the cycloolefin represented by the formula (I) include norbornene, 5-methylnorbornene, 5-ethylnorbornene, 5-butylnorbornene, 5-phenylnorbornene, 5-benzylnorbornene, tetracyclododecene, tricyclodecene, tricycloundecene, pentacyclopentadecene, pentacyclohexadecene, 8-methyltetracyclododecene, and 8-ethyltetracyclododecene. Among them, norbornene is preferable from the viewpoints of availability of raw material monomers, reduction in particle diameter and CTE of the film, and improvement in heat resistance of the film. The cycloolefin represented by the formula (I) may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

In one embodiment of the present invention, the cycloolefin-based polymer preferably has a double bond chain structure of the monomer unit (I). By including such a double-linked chain structure, heat resistance can be easily improved as compared with a polymer having the same content of the monomer unit (I). The presence or absence of the double-link structure may be determined by ¹³ And C-NMR spectrum analysis. For example, in the case of tetracyclodecene-ethylene copolymers, signals from the ethylene-tetracyclodecene-ethylene linkage as the independent chain of tetracyclodecene appeared around 54.7ppm and around 51.1ppm, and signals from the ethylene-tetracyclodecene-ethylene linkage as the double linkage of tetracyclodecene with an endo-exo linkage appeared at 51.5ppm and around 50.8ppm, and signals from the exo-exo (exo-exo) bonded ethylene-tetracyclodecene-ethylene linkage appeared around 55.3ppm and around 54.3ppm, and therefore, it was possible to determine from the pattern of signals around 55ppm and around 50 ppm.

The double-bond chain structure of the monomer unit (I) includes a meso-type double-bond chain represented by the following structural formula (II-1) or the following structural formula (II-2), and/or a racemic-type double-bond chain represented by the following structural formula (III-1) or the following structural formula (III-2).

[ chemical formula 3]

The ratio of the meso type double-link chain to the racemic type double-link chain (hereinafter, may be referred to as meso type double-link chain/racemic type double-link chain) is preferably 0.50 or less, more preferably 0.40 or less, still more preferably 0.30 or less, particularly preferably 0.20 or less, preferably 0.01 or more, and more preferably 0.05 or more. When the ratio of the meso type double bond chain to the racemic type double bond chain is within the above range, the mechanical properties and heat resistance of the film can be easily improved. The ratio of meso form of the double-linked chain to racemic form of the double-linked chain may be used ¹³ C-NMR can be calculated based on the assignments described in "r.a.wendt, g.fink, macromol.chem.phys.,2001,202,3490" and "japanese patent application laid-open No. 2008-285656", and specifically, can be calculated by the method described in examples. As a method for adjusting the meso-type double bond and the racemic-type double bond to fall within the above range, there is a method of selecting a catalyst having an appropriate ligand width with respect to the stack height of the monomer, and the like. As the catalyst, for example, a catalyst described in Japanese patent laid-open No. 9-183809 can be used. In the present specification, the term "mechanical properties" means mechanical properties including bending resistance and elastic modulus, and the term "mechanical properties" means, for example, that bending resistance and/or elastic modulus are increased or improved.

Relative to each otherThe content of the monomer unit (I) in the cycloolefin polymer is preferably 60mol% or more, more preferably 65mol% or more, further preferably 70mol% or more, particularly preferably 75mol% or more, preferably 100mol% or less, more preferably 99mol% or less, and further preferably 98mol% or less, based on the total molar amount of the repeating units constituting the cycloolefin polymer. When the content of the monomer unit (I) is not less than the above lower limit, the glass transition temperature (hereinafter, sometimes referred to as Tg) is easily increased, and hence the CTE of the film is easily decreased, and the lightness of the film is easily decreased, and therefore the water absorption resistance is easily increased. In addition, the mechanical properties such as heat resistance and bending resistance of the film are easily improved. When the content of the monomer unit (I) is not more than the above upper limit, mechanical properties such as bending resistance can be easily improved. The content of the monomer unit (I) may be used ¹³ C-NMR can be calculated based on the assignment described in "r.a.wendt, g.fink, macr omol.chem.phys.,2001,202,3490", for example, by the method described in examples.

The cycloolefin polymer preferably contains at least 1 monomer unit (II) selected from the group consisting of ethylene, a linear α -olefin having 3 to 20 carbon atoms, and an aromatic vinyl compound having 8 to 20 carbon atoms, and more preferably contains a monomer unit (II) derived from ethylene, from the viewpoint of easily lowering the CTE of the film and easily improving mechanical properties such as water absorption resistance and bending resistance.

Examples of the linear α -olefin having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene. Among them, propylene, 1-butene, 1-hexene or 1-octene is preferable, and propylene is more preferable, from the viewpoint of easily lowering the CTE of the film and easily improving the mechanical properties such as water absorption resistance and bending resistance. The linear alpha-olefin having 3 to 20 carbon atoms may be used alone in 1 kind or in combination with 2 or more kinds. The "linear α -olefin" refers to a linear olefin having a carbon-carbon unsaturated double bond at the α -position.

Examples of the aromatic vinyl compound having 8 to 20 carbon atoms include styrene, methylstyrene, dimethylstyrene, ethylstyrene, t-butylstyrene, vinylnaphthalene, vinylanthracene, diphenylethylene, isopropenylbenzene, isopropenyltoluene, isopropenylethylbenzene, isopropenylpropylbenzene, isopropenylbutylbenzene, isopropenylpentylbenzene, isopropenylhexylbenzene, isopropenyloctylbenzene, isopropenylnaphthalene, isopropenylanthracene, and the like. Among them, styrene, methylstyrene or dimethylstyrene is preferable, and styrene is more preferable, from the viewpoints of easiness of obtaining raw material monomers, easiness of lowering the CTE of the film, and easiness of improving mechanical properties such as bending resistance. The aromatic vinyl compound having 8 to 20 carbon atoms may be used alone in 1 kind or in combination with 2 or more kinds.

In one embodiment of the present invention, the cycloolefin polymer preferably contains at least 1 monomer unit (II) selected from the group consisting of ethylene, propylene, and styrene, and more preferably at least 1 monomer unit (II) selected from the group consisting of ethylene and styrene, from the viewpoints of easiness in obtaining raw material monomers, easiness in lowering the CTE of a film, and easiness in improving mechanical properties such as bending resistance.

The content of the monomer unit (II) in the cycloolefin polymer is preferably 0mol% or more, more preferably 0.01mol% or more, further preferably 1mol% or more, further more preferably 2mol% or more, preferably 40mol% or less, more preferably 35mol% or less, further preferably 30mol% or less, and particularly preferably 25mol% or less, based on the total molar amount of the repeating units constituting the cycloolefin polymer. When the content of the monomer unit (II) is not less than the above lower limit, mechanical properties such as bending resistance, processability and moldability of the film are easily improved. When the content of the monomer unit (II) is not more than the above upper limit, the CTE of the film is easily lowered, and the mechanical properties such as water absorption resistance, heat resistance, and bending resistance are easily improved.

In one embodiment of the present invention, the cycloolefin polymer is preferably a cycloolefin copolymer, more preferably a cycloolefin copolymer including a monomer unit (I) derived from a cycloolefin represented by the formula (I) and a monomer unit (II) derived from at least 1 selected from the group consisting of ethylene, a linear α -olefin having 3 to 20 carbon atoms, and an aromatic vinyl compound having 8 to 20 carbon atoms, and further preferably an ethylene-norbornene copolymer including a monomer unit (I) derived from norbornene and a monomer unit (II) derived from ethylene, or a styrene-norbornene copolymer including a monomer unit (I) derived from norbornene and a monomer unit (II) derived from styrene, from the viewpoints of easily improving mechanical properties such as heat resistance, processability, and bending resistance and easily reducing the particle diameter and the CTE.

The cycloolefin polymer may contain other monomer unit (III). Examples of the other monomer constituting the other monomer unit (III) include conjugated dienes such as butadiene and isoprene; 1,4-a non-conjugated diene such as pentadiene; acrylic acid; acrylic esters such as methyl acrylate and ethyl acrylate; methacrylic acid; methacrylic acid esters such as methyl methacrylate and ethyl methacrylate; vinyl acetate, and the like. The other monomer units (III) may be used alone or in combination of two or more.

The polymer (B) may be used alone or in combination of two or more.

In one embodiment of the present invention, the olefin-based polymer other than the cycloolefin-based polymer includes, for example, a polymer containing the monomer unit (II); the aforementioned monomer unit (III); at least 1 monomer unit selected from the group consisting of 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene and vinylcycloalkane; and derivatives thereof, are preferably polyethylene, high-density polyethylene, polypropylene or polymethylpentene, and among these, polypropylene or polymethylpentene is more preferable from the viewpoint of improving heat resistance.

In one embodiment of the present invention, the polyimide-based polymer includes, for example, a polyimide-based polymer soluble in the 1 st solvent.

In one embodiment of the present invention, the fluorine-based polymer is a polymer of an olefin containing fluorine or a modified product thereof, and specifically, there may be mentioned a polymer and a copolymer containing at least 1 kind of monomer unit selected from the group consisting of a fluoroolefin, for example, tetrafluoroethylene, trifluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinylidene fluoride, vinyl fluoride and the like, and there may be mentioned, for example, polytetrafluoroethylene (hereinafter, sometimes referred to as PTFE), perfluoroalkoxyalkane, perfluoroethylene propylene copolymer, ethylene-tetrafluoroethylene copolymer, polyvinylidene fluoride, polychlorotrifluoroethylene, polyhexafluoropropylene and the like. From the viewpoint of improving the dielectric characteristics of the film, the fluoropolymer is preferably a polymer having a structural unit derived from tetrafluoroethylene, more preferably the molar ratio of the structural unit derived from tetrafluoroethylene to the total of all the structural units is 0.25 or more, still more preferably the molar ratio is 0.30 or more, still more preferably 0.50 or more, and particularly preferably 0.75 or more. The molar ratio of each structural unit of the fluoropolymer can be determined by NMR measurement, and for the calculation of the molar ratio, for example, eric B.Twinum et al, "Multidimensional 19F NMR analytes of catalysts from Vinylidenefluoride (VDF) -Hexafluoropropyl (HFP) -Teflon (TFE)", macromolecules,2015, volume 48, phase 11, p.3563-3576 can be referred to. In addition, from the viewpoint of improving solubility in the 1 st solvent, a copolymer of at least 1 selected from the group consisting of vinyl ethers, vinyl esters, and allyl ethers and the monomer unit may be used.

In one embodiment of the present invention, the liquid crystal polymer includes a polymer having a repeating unit of an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid, an aromatic diol, an aliphatic diol, or the like.

Specific examples of the monomer providing the aromatic hydroxycarboxylic acid repeating unit include aromatic hydroxycarboxylic acids such as p-hydroxybenzoic acid, m-hydroxybenzoic acid, o-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 5-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 4' -hydroxyphenyl-4-benzoic acid, 3' -hydroxyphenyl-4-benzoic acid, and 4' -hydroxyphenyl-3-benzoic acid, and alkyl, alkoxy, and halogen substituents thereof, and ester-forming derivatives thereof. Among them, parahydroxybenzoic acid and 6-hydroxy-2-naphthoic acid are preferable from the viewpoint of easily improving the water absorption resistance, mechanical properties and heat resistance of the film.

Specific examples of the monomer providing the aromatic dicarboxylic acid repeating unit include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 4,4' -dicarboxybiphenyl, alkyl, alkoxy, halogen-substituted compounds thereof, and ester-forming derivatives thereof. Among them, terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid are preferable from the viewpoint of easily improving the water absorption resistance, mechanical properties, and heat resistance of the film.

Specific examples of the monomer providing the aromatic diol repeating unit include aromatic diols such as hydroquinone, resorcinol, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 4,4 '-dihydroxybiphenyl, 3,3' -dihydroxybiphenyl, 3,4 '-dihydroxybiphenyl, and 4,4' -dihydroxydiphenyl ether, alkyl, alkoxy, or halogen substituents thereof, and ester-forming derivatives thereof. Among them, hydroquinone and 3,3' -dihydroxybiphenyl are preferable from the viewpoint of easily improving the water absorption resistance, mechanical properties and heat resistance of the film.

Specific examples of the monomer providing the aliphatic diol repeating unit include aliphatic diols such as ethylene glycol, 1,4-butanediol, and 1,6-hexanediol, and acylates thereof. Among them, ethylene glycol is preferable from the viewpoint of easily improving the water absorption resistance, mechanical properties and heat resistance of the film.

In one embodiment of the present invention, the styrenic polymer is a resin containing at least 1 styrene in a repeating structural unit, and examples thereof include polystyrene, ABS resin (acrylonitrile-butadiene-styrene copolymer), AS resin (acrylonitrile-styrene copolymer), and the like. Among them, polystyrene is preferable from the viewpoint of easy improvement of dielectric properties.

In one embodiment of the present invention, the ether polymer is a resin containing at least 1 repeating unit containing an ether group in the main chain, and examples thereof include polyether imide, polyphenylene ether, polyether sulfone, polyether ketone, polyether ether ketone, and the like. Among them, polyphenylene ether, polyether sulfone, and polyether ether ketone are preferable from the viewpoint of easily improving the water absorption resistance and the dielectric characteristics of the film.

In one embodiment of the present invention, the weight average molecular weight (hereinafter, the weight average molecular weight may be abbreviated as Mw) of the polymer (B) is preferably 10,000 or more, more preferably 15,000, further preferably 20,000 or more, further more preferably 30,000 or more, particularly preferably 50,000 or more, particularly preferably 70,000 or more, particularly preferably 90,000 or more, preferably 2,000,000 or less, more preferably 1,000,000 or less, and further preferably 700,000 or less. When Mw is not less than the above lower limit, water absorption resistance and heat resistance of the film are easily improved, and strength is easily improved. When Mw is not more than the above upper limit, water absorption resistance, mechanical properties and moldability of the film are easily improved.

In one embodiment of the present invention, the ratio (Mw/Mn) of Mw and the number average molecular weight (hereinafter, the number average molecular weight may be abbreviated as Mn) of the polymer (B) is preferably 2.5 or less, more preferably 2.2 or less, further preferably 2.0 or less, further more preferably 1.95 or less, particularly preferably 1.90 or less, preferably 1.30 or more, more preferably 1.50 or more, further preferably 1.60 or more, and particularly preferably 1.65 or more in terms of polystyrene. When the Mw/Mn ratio is not more than the above upper limit, the water absorption resistance and mechanical properties of the film are easily improved, and when it is not less than the above lower limit, the moldability is easily improved. The Mw and Mn can be determined by gel permeation chromatography (hereinafter, sometimes abbreviated as GPC) measurement and conversion to standard polystyrene, and can be determined, for example, by the method described in examples.

In one embodiment of the present invention, the refractive index of the polymer (B) is preferably 1.600 or less, more preferably 1.570 or less, even more preferably 1.550 or less, preferably 1.500 or more, and more preferably 1.520 or more, from the viewpoint of easily obtaining a film having a reduced CTE. The refractive index of the polymer (B) can be measured by a refractometer, for example, by the method described in examples.

In one embodiment of the present invention, the CTE of the polymer (B) is preferably 110ppm/K or less, more preferably 80 ppm/K or less, further preferably 58ppm/K or less, further more preferably 55ppm/K or less, particularly preferably 50ppm/K or less, preferably 0ppm/K or more, more preferably 0.01ppm/K or more, further preferably 1ppm/K or more, and further more preferably 5ppm/K or more. When the CTE of the polymer (B) is not more than the upper limit, the CTE of the obtained film is easily lowered. In the case of producing a copper-clad laminate by laminating a copper foil, the CTE of the film is preferably adjusted to about 20ppm/K from the viewpoint of preventing peeling of the laminate film. The polymer (B) having the most suitable CTE can be selected according to the CTE of the resin to be mixed. The CTE can be measured by, for example, thermomechanical analysis (hereinafter, sometimes referred to as TMA), and can be determined by the method described in examples.

In one embodiment of the present invention, at least one of the glass transition temperature and the melting point of the polymer (B) is preferably 100 ℃. The Tg of the polymer (B) is preferably 100 ℃ or higher, more preferably 140 ℃ or higher, further preferably 160 ℃ or higher, further more preferably 180 ℃ or higher, particularly preferably 200 ℃ or higher, particularly preferably 220 ℃ or higher, particularly preferably 240 ℃ or higher, most preferably 260 ℃ or higher, preferably 500 ℃ or lower, more preferably 400 ℃ or lower, further preferably 350 ℃ or lower, and further more preferably 320 ℃ or lower. When the polymer (B) is a crystalline polymer having a melting point, the melting point of the polymer (B) is preferably 100 ℃ or higher, more preferably 140 ℃ or higher, further preferably 160 ℃ or higher, further more preferably 180 ℃ or higher, particularly preferably 200 ℃ or higher, particularly preferably 220 ℃ or higher, particularly preferably 240 ℃ or higher, most preferably 260 ℃ or higher, preferably 500 ℃ or lower, more preferably 400 ℃ or lower, and further preferably 350 ℃ or lower. When at least one of the Tg and the melting point of the polymer (B) is not less than the above lower limit, the CTE of the film is easily lowered, and the mechanical properties such as water absorption resistance, heat resistance, and bending resistance are easily further improved. When at least one of the Tg and the melting point of the polymer (B) is not more than the above upper limit, the mechanical properties of the film, particularly the repeated bending resistance, can be easily improved. The Tg of the polymer (B) is a softening temperature measured by TMA in accordance with JIS K7196, and can be measured, for example, by the method described in examples. The method for adjusting Tg and melting point of the polymer (B) is not particularly limited, and examples thereof include a method for appropriately adjusting the content of the monomer unit (I), mw of the polymer (B), and crystallinity. The larger the at least one selected from the group consisting of the content of the monomer unit (I), the Mw of the polymer (B), and the crystallinity, the higher the Tg and the melting point of the polymer (B) tend to be. The melting point of the polymer (B) can be determined, for example, by the following method: the melting peak temperature was measured from the thus-obtained melting curve using a differential scanning calorimeter (DSC, manufactured by Hitachi High-Tech Science Corporation).

In one embodiment of the present invention, the average primary particle diameter of the particulate polymer (B) is preferably 15 μm or less, more preferably 10 μm or less, further preferably 5 μm or less, further more preferably 3 μm or less, particularly preferably 1 μm or less, particularly preferably 0.8 μm or less, particularly preferably 0.5 μm or less, preferably 0.01 μm or more, more preferably 0.03 μm or more, and further preferably 0.05 μm or more. When the average primary particle diameter of the particulate polymer (B) is not less than the above lower limit, the mechanical properties of the film are easily improved. When the average primary particle diameter of the particulate polymer (B) is not more than the above upper limit, the particle dispersibility of the particulate polymer (B) is likely to be improved, and the lightness is likely to be lowered, and as a result, the water absorption resistance of the film is likely to be improved, and the mechanical properties such as the surface smoothness and the bending resistance of the film are likely to be improved. The average primary particle diameter of the particulate polymer (B) can be determined by image analysis of an image captured by an electron microscope. For example, a cross-sectional view of the film can be observed using a Scanning Transmission Electron Microscope (STEM), and the particle diameters of 50 or more particles can be measured from the observed image, and the average value of these particles can be used as the average primary particle diameter of the particulate cycloolefin copolymer.

The content of the particulate polymer (B) is usually 1 mass% or more, preferably 5 mass% or more, more preferably 10 mass% or more, further preferably 15 mass% or more, particularly preferably 20 mass% or more, preferably 50 mass% or less, more preferably 40 mass% or less, further preferably 35 mass% or less, and particularly preferably 30 mass% or less, with respect to the total mass of the polyimide resin (a) and the particulate polymer (B) contained in the film. When the content of the particulate polymer (B) is not less than the above lower limit, the particle dispersibility in the film is easily improved, so that the brightness of the film is easily reduced, and the water absorption resistance, the surface smoothness, and the mechanical properties are easily improved. When the content of the particulate polymer (B) is not more than the above upper limit, the brightness of the film is easily decreased, and the moldability is easily improved. Since the uniformity of thermal conductivity and CTE is high when the dispersibility of particles in the film is high, for example, when the film is used as a resin layer of CCL, peeling between the film and the copper foil is easily suppressed.

< Process for producing Polymer (B) >

The polymer (B) may be a commercially available polymer or may be produced by a conventional method. In one embodiment of the present invention, the polymer (B) is preferably a cycloolefin polymer. The method for producing the cycloolefin polymer is not particularly limited, and for example, it is preferable to produce the cycloolefin polymer by polymerizing a monomer that forms the cycloolefin polymer, for example, a cycloolefin represented by the formula (I), at least 1 monomer selected from the group consisting of ethylene, a linear α -olefin having 3 to 20 carbon atoms, and an aromatic vinyl compound having 8 to 20 carbon atoms, and optionally the other monomer in the presence of a catalyst that uses a transition metal complex (α) represented by the formula (IV) as one component. In the production of the cycloolefin polymer according to the present invention, since the transition metal complex (α) represented by the formula (IV) is used, the content of the monomer unit (I) in the cycloolefin polymer can be easily increased significantly, and the Tg can be easily adjusted to the above range.

[ chemical formula 4]

[ in the formula (IV), M represents a transition metal element of group 4 of the periodic Table of the elements,

cp represents a group having a cyclopentadienyl skeleton,

a represents an atom of group 16 of the periodic Table of the elements,

t represents an atom of group 14 of the periodic Table of the elements,

D ¹ and D ² They may be the same or different and represent a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms or a disubstituted amino group having 2 to 20 carbon atoms.

R ¹ ～R ⁶ Represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, a disubstituted amino group having 2 to 20 carbon atoms or a silyl group having 1 to 20 carbon atoms, and they may be the same or different and may be optionally bonded to form a ring.]

M is a transition metal element of group 4 of the periodic Table of the elements (revised 1989 of IUPAC inorganic chemical nomenclature), and examples thereof include a titanium atom, a zirconium atom, a hafnium atom and the like.

Cp is a group having a cyclopentadienyl skeleton, and examples thereof include cyclopentadienyl group, substituted cyclopentadienyl group, indenyl group, substituted indenyl group, fluorenyl group, and substituted fluorenyl group. Specific examples thereof include cyclopentadienyl, methylcyclopentadienyl, tetramethylcyclopentadienyl, n-propylcyclopentadienyl, n-butylcyclopentadienyl, isobutylcyclopentadienyl, phenylcyclopentadienyl, indenyl, methylindenyl, n-propylindenyl, n-butylindenyl, isobutylindenyl, phenylindenyl, fluorenyl, methylfluorenyl, n-propylfluorenyl, phenylfluorenyl and dimethylfluorenyl. Among them, preferable examples include cyclopentadienyl, methylcyclopentadienyl, tetramethylcyclopentadienyl, n-butylcyclopentadienyl, isobutylcyclopentadienyl, indenyl, methylindenyl or fluorenyl.

A is an atom of group 16 of the periodic Table of the elements, and examples thereof include an oxygen atom, a sulfur atom and the like. Among them, oxygen atom is preferable.

T is an atom of group 14 of the periodic Table of the elements, and examples thereof include a carbon atom, a silicon atom, a germanium atom and the like. Among them, a carbon atom or a silicon atom is preferable.

D ¹ 、D ² Independently of each other, a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms or a disubstituted amino group having 2 to 20 carbon atoms, which may be the same or different. Among them, a halogen atom is preferable.

As D ¹ 、D ² Specific examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

D ¹ 、D ² In the case of a hydrocarbon group, the number of carbon atoms is preferably 1 to 10. Examples of the hydrocarbon group include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a n-pentyl group, a neopentyl group, a n-hexyl group, a n-octyl group, a phenyl group, a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, a naphthyl group, and a benzyl group.

As D ¹ 、D ² <xnotran> , , ,1- , 3292 zxft 3292- , 3426 zxft 3426- , 3474 zxft 3474- , , , ,1- , 3567 zxft 3567- , 3592 zxft 3592- , 3725 zxft 3725- , 4235 zxft 4235- , , ,1- , 4287 zxft 4287- , 5252 zxft 5252- , 6258 zxft 6258- , 6258 zxft 6258- ,2- ,3- ,4- , 6258 zxft 6258- , 6258 zxft 6258- , 6258 zxft 6258- , 6258 zxft 6258- , 6258 zxft 6258- , 6258 zxft 6258- , 6258 zxft 6258- , 6258 zxft 6258- , 6258 zxft 6258- , ,2- ,3- ,4- , 6258 zxft 6258- , 6258 zxft 6258- , 6258 zxft 6258- , 6258 zxft 6258- , 6258 zxft 6258- , 6258 zxft 6258- , 6258 zxft 6258- , 6258 zxft 6258- , 6258 zxft 6258- , ,2- ,3- ,4- , 6258 zxft 6258- </xnotran>Phenyl, 2,4-dibromophenyl, 2,5-dibromophenyl, 2,6-dibromophenyl, 2,3,4-tribromophenyl, 2,3,5-tribromophenyl, 2,3,6-tribromophenyl, 2,3,4,5-tetrabromphenyl, 2,3,4,6-tetrabromphenyl, pentabromophenyl, and the like.

As D ¹ 、D ² Specific examples of the alkoxy group include methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, neopentoxy, n-hexoxy, n-octoxy and the like.

As D ¹ 、D ² Specific examples of the aryloxy group include a phenoxy group, a 2-methylphenoxy group, a 3-methylphenoxy group, a 4-methylphenoxy group, a naphthyloxy group and the like.

So-called D ¹ 、D ² The disubstituted amino group in the case of a disubstituted amino group is an amino group to which 2 substituents are bonded. Specific examples thereof include dimethylamino group, diethylamino group, di-n-propylamino group, diisopropylamino group, di-n-butylamino group, diisobutylamino group, di-sec-butylamino group, di-tert-butylamino group, di-n-hexylamino group, di-n-octylamino group, diphenylamino group and the like.

R ¹ ～R ⁶ Independently of one another, a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, a disubstituted amino group having 2 to 20 carbon atoms or a silyl group having 1 to 20 carbon atoms, and they may be the same or different, and they may optionally bond to form a ring. Among them, a hydrocarbon group having 1 to 20 carbon atoms is preferable.

R ¹ ～R ⁶ In the case of a hydrocarbon group, the number of carbon atoms is preferably 1 to 10. Specific examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, neopentyl group, n-hexyl group, n-octyl group, phenyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 2,3-dimethylphenyl group, 2,4-dimethylphenyl group, 2,5-dimethylphenyl group, 2,6-dimethylphenyl group, 2,3,4-trimethylphenyl group, 2,3,5-trimethylphenyl groupPhenylphenyl, 2,3,6-trimethylphenyl, 2,3,4,5-tetramethylphenyl, 2,3,4,6-tetramethylphenyl, pentamethylphenyl, and the like.

As R ¹ ～R ⁶ Specific examples of the halogen atom, halogenated hydrocarbon group, alkoxy group, aryloxy group and di-substituted amino group include D ¹ 、D ² Examples of the halogen atom, the halogenated hydrocarbon group, the alkoxy group, the aryloxy group and the di-substituted amino group are mentioned above.

As R ¹ ～R ⁶ Specific examples of the silyl group include a trimethylsilyl group, a triethylsilyl group, a tri-n-propylsilyl group, a triisopropylsilyl group, a tri-n-butylsilyl group, a triisobutylsilyl group, a tri-sec-butylsilyl group, a tri-tert-butylsilyl group, and a triphenylsilyl group.

Specific examples of the compound represented by the formula (IV) include isopropylidene (cyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) titanium dichloride, isopropylidene (methylcyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) titanium dichloride, isopropylidene (dimethylcyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) titanium dichloride, isopropylidene (trimethylcyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) titanium dichloride, isopropylidene (tetramethylcyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) titanium dichloride, isopropylidene (n-propylcyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) titanium dichloride, isopropylidene (n-butylcyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) titanium dichloride, isopropylidene (isobutylcyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) titanium dichloride, isopropylidene (phenylcyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) titanium dichloride, isopropylidene (3-tert-butyl-5-methyl-2-phenoxy) titanium dichloride Titanium dichloride, isopropylidene (methylcyclopentadienyl) (3-tert-butyl-2-phenoxy) titanium dichloride, isopropylidene (dimethylcyclopentadienyl) (3-tert-butyl-2-phenoxy) titanium dichloride, isopropylidene (trimethylcyclopentadienyl) (3-tert-butyl-2-phenoxy) titanium dichloride, isopropylidene (tetramethylcyclopentadienyl) (3-tert-butyl-2-phenoxy) titanium dichloride, isopropylidene (n-propylcyclopentadienyl) (3-tert-butyl-2-phenoxy) titanium dichloride, isopropylidene (n-butylcyclopentadienyl) (3-tert-butyl-2-phenoxy) titanium dichloride, isopropylidene (isobutylcyclopentadienyl) (3-tert-butyl-2-phenoxy) titanium dichloride, isopropylidene (phenylcyclopentadienyl) (3-tert-butyl-2-phenoxy) titanium dichloride, isopropylidene (cyclopentadienyl) (2-phenoxy) titanium dichloride, isopropylidene (methylcyclopentadienyl) (2-phenoxy) titanium dichloride, isopropylidene (dimethylcyclopentadienyl) (2-phenoxy) titanium dichloride, isopropylidene (trimethylcyclopentadienyl) (2-phenoxy) titanium dichloride, isopropylidene (2-phenoxy) titanium dichloride, isopropylidene (n-propylcyclopentadienyl) (2-phenoxy) titanium dichloride, isopropylidene (n-butylcyclopentadienyl) (2-phenoxy) titanium dichloride, isopropylidene (isobutylcyclopentadienyl) (2-phenoxy) titanium dichloride, isopropylidene (phenylcyclopentadienyl) (2-phenoxy) titanium dichloride and the like.

In addition, compounds obtained by changing titanium to zirconium or hafnium in the above specific examples, and compounds obtained by changing isopropylidene to dimethylsilylene, diphenylsilylene, or methylene including these compounds can also be exemplified in the same manner. Examples of compounds obtained by changing the dichloride to dibromide, diiodide, dimethyl, dibenzyl, dimethoxy (dimethoxide) and diethoxy (diethoxy) compounds are also given in the same manner.

The transition metal complex (α) represented by the above formula (IV) can be used as a catalyst for producing the polymer (B) according to one embodiment of the present invention in combination with various cocatalysts. The cocatalyst is a compound which interacts with the transition metal complex (α) to generate a polymerization active species for cyclic olefins and alkenyl aromatic hydrocarbons. Examples thereof include an organoaluminum compound (β) and/or a boron compound (γ) represented by any one of the following formulae (γ 1) to (γ 3), but the structure of the polymerization active species generated by using these cocatalysts is not clear.

Formula (gamma 1) BQ ¹ Q ² Q ³

Formula (. Gamma.2) J ⁺ (BQ ¹ Q ² Q ³ Q ⁴ ) ^-

Formula (gamma 3) (L-H) ⁺ (BQ ¹ Q ² Q ³ Q ⁴ ) ^-

[ in the formulae (γ 1) to (γ 3), B represents a boron atom in a valence state of 3,

Q ¹ ～Q ⁴ independently represents a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, a substituted silyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms or a disubstituted amino group having 2 to 20 carbon atoms,

J ⁺ denotes an inorganic or organic cation, and is,

l represents a neutral Lewis base, (L-H) ⁺ Represents a Bronsted acid.]

As the organoaluminum compound (β), a known organoaluminum compound can be used. Specifically, there may be mentioned an organoaluminum compound represented by the formula (. Beta.1), a cyclic aluminoxane having a structure represented by the formula (. Beta.2), and a linear aluminoxane having a structure represented by the formula (. Beta.3), and these may be used alone or in combination of 2 or more.

Formula (. Beta.1) E ¹ _a AlZ _3-a

Formula (. Beta.2) { -Al (E) ² )-O-} _b

Formula (. Beta.3) E ³ {-Al(E ³ )-O-} _c AlE ³ ₂

[ formula (. Beta.1) to formula (. Beta.3) wherein E is ¹ 、E ² And E ³ Independently of each other, a hydrocarbon group having 1 to 8 carbon atoms, and all E ¹ All of E ² And all of E ³ Z may be the same or different and represents hydrogen or halogen, all Z may be the same or different, a represents an integer of 0 to 3, b represents an integer of 2 or more, and c represents an integer of 1 or more.]

Specific examples of the formula (. Beta.1) include trialkylaluminums such as trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, trihexylaluminum and the like; dialkylaluminum chlorides such as dimethylaluminum chloride, diethylaluminum chloride, dipropylaluminum chloride, diisobutylaluminum chloride and dihexylaluminum chloride; alkylaluminum dichlorides such as methylaluminum dichloride, ethylaluminum dichloride, propylaluminum dichloride, isobutylaluminum dichloride and hexylaluminum dichloride; dialkylaluminum hydrides such as dimethylaluminum hydride, diethylaluminum hydride, dipropylaluminum hydride, diisobutylaluminum hydride and dihexylaluminum hydride. Among them, trialkylaluminum is preferable, and triethylaluminum or triisobutylaluminum is more preferable.

E in the formulae (. Beta.2) and (. Beta.3) ² 、E ³ Specific examples thereof include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl and neopentyl. Among them, preferred is methyl or isobutyl. b is an integer of 2 or more, preferably an integer of 2 to 40. c is an integer of 1 or more, preferably an integer of 1 to 40.

The above aluminoxane can be prepared by various methods. The method is not particularly limited, and the composition may be prepared by a known method. For example, the following methods can be exemplified: a method in which a solution obtained by dissolving trialkylaluminum, for example, trimethylaluminum, in an appropriate organic solvent, for example, benzene, aliphatic hydrocarbon, or the like, is brought into contact with water; a method of producing the compound by bringing trialkylaluminum, for example, trimethylaluminum, into contact with a metal salt containing crystal water, for example, copper sulfate hydrate.

As the boron compound (γ), any of boron compounds represented by the formula (γ 1), the formula (γ 2) or the formula (γ 3) can be used.

In the formula (. Gamma.1), B represents a boron atom in a valence state of 3, and Q ¹ ～Q ³ Independently represent a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, a substituted silyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms or a disubstituted amino group having 2 to 20 carbon atoms, and they may be the same or different. Q ¹ ～Q ³ Independently of one another, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a halogenated hydrocarbon group having 1 to 20 carbon atoms is preferable.

Specific examples of the boron compound represented by the formula (. Gamma.1) include tris (pentafluorophenyl) borane, tris (2,3,5,6-tetrafluorophenyl) borane, tris (2,3,4,5-tetrafluorophenyl) borane, tris (3,4,5-trifluorophenyl) borane, tris (2,3,4-trifluorophenyl) borane, phenylbis (pentafluorophenyl) borane, etc., and tris (pentafluorophenyl) borane is preferably used.

In the formula (. Gamma.2), B represents a boron atom in a valence state of 3, and Q ¹ ～Q ⁴ And Q in the above formula (. Gamma.1) ¹ ～Q ³ The same is true. In addition, J ⁺ Denotes an inorganic or organic cation.

As J ⁺ Examples of the inorganic cation in (b) include ferrocenium cation, alkyl-substituted ferrocenium cation, and silver cation.

As J ⁺ Examples of the organic cation in (b) include trityl cation.

As (BQ) ¹ Q ² Q ³ Q ⁴ ) ^- Examples thereof include tetrakis (pentafluorophenyl) borate anion, tetrakis (2,3,5,6-tetrafluorophenyl) borate anion, tetrakis (2,3,4,5-tetrafluorophenyl) borate anion, tetrakis (3,4,5-trifluorophenyl) borate anion, tetrakis (2,2,4-trifluorophenyl) borate anion, phenylbis (pentafluorophenyl) borate anion, and tetrakis (3,5-bistrifluoromethylphenyl) borate anion.

Specific combinations thereof include ferrocenium tetrakis (pentafluorophenyl) borate, 1,1' -dimethylferrocenium tetrakis (pentafluorophenyl) borate, silver tetrakis (pentafluorophenyl) borate, trityltetrakis (3,5-bistrifluoromethylphenyl) borate, etc., and preferable examples thereof include trityltetrakis (pentafluorophenyl) borate.

In the formula (. Gamma.3), B represents boron in a valence state of 3, and Q ¹ ～Q ⁴ And Q in the above formula (. Gamma.1) ¹ ～Q ³ The same is true. Further, L represents a neutral Lewis base, (L-H) ⁺ Represents a Bronsted acid.

(L-H) in the formula (. Gamma.3) as Bronsted acid ⁺ Examples thereof include trialkyl-substituted ammonium cations, N-dialkylanilinium cations, dialkylammonium cations and triaryl cationsPhosphonium based cations, and the like.

As (BQ) ¹ Q ² Q ³ Q ⁴ ) ^- Examples thereof include the same ions as described above.

Specific combinations thereof include triethylammonium tetrakis (pentafluorophenyl) borate, tripropylammonium tetrakis (pentafluorophenyl) borate, tri (N-butyl) ammonium tetrakis (3,5-bistrifluoromethylphenyl) borate, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, N-diethylanilinium tetrakis (pentafluorophenyl) borate, N-pentafluorophenylborate, N-2,4,6-pentamethylanilinium, N-dimethylanilinium tetrakis (3,5-bistrifluoromethylphenyl) borate, diisopropylammonium tetrakis (pentafluorophenyl) borate, dicyclohexylammonium tetrakis (pentafluorophenyl) borate, triphenylphosphonium tetrakis (pentafluorophenyl) borate, tris (methylphenyl) phosphonium tetrakis (pentafluorophenyl) borate, tris (dimethylphenyl) phosphonium tetrakis (pentafluorophenyl) borate, and the like. Among them, tri (N-butyl) ammonium tetrakis (pentafluorophenyl) borate or N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate is preferable.

As the co-catalyst, it is preferable to use an organoaluminum compound (β) and a compound (γ) in combination.

The transition metal complex (α) represented by the formula (IV), the organoaluminum compound (β) and/or the compound (γ) may be added in any order at the time of polymerization and used, or a reaction product obtained by contacting a combination of any of them in advance may be used.

The molar ratio of cocatalyst/transition metal complex (. Alpha.) is preferably 0.01 to 10,000, more preferably 0.5 to 2,000. When the catalyst component is used in the form of a solution, the concentration of the transition metal complex (. Alpha.) is preferably 0.0001 to 5mmol/L, more preferably 0.001 to 1mmol/L. The amount of the catalyst component used is preferably 0.00001 to 1mol%, more preferably 0.0001 to 0.1mol%, based on the total amount of all monomers used.

The polymerization method of the polymer (B) according to one embodiment of the present invention is not particularly limited, and any method such as a batch or continuous gas phase polymerization method, a bulk polymerization method, a solution polymerization method or a slurry polymerization method using an appropriate solvent, or the like can be used.

When a solvent is used, various solvents can be used under such conditions that the catalyst is not deactivated, and examples of such solvents include hydrocarbon solvents such as benzene, toluene, pentane, hexane, heptane, cyclohexane, and the like; halogenated hydrocarbon solvents such as methylene chloride and dichloroethane.

When a solvent is used, the ethylene partial pressure in the system during polymerization is, for example, 50 to 400kPa, preferably 50 to 300kPa, and the hydrogen partial pressure is preferably 0 to 100kPa. When ethylene and hydrogen are added to the system, it is preferable to pressurize the system by the partial pressure of hydrogen and then to pressurize the system by the partial pressure of ethylene. Alternatively, the solution of the cycloolefin represented by the formula (I) may be fed into the polymerization reaction tank, and then toluene may be further fed.

The polymerization temperature is preferably 50 ℃ or higher, more preferably 50 to 150 ℃, and still more preferably 50 to 100 ℃. A chain transfer agent such as hydrogen may be added to adjust the molecular weight of the polymer.

< polyimide resin (A) >

The polyimide-based resin (a) includes a resin containing a repeating structural unit containing an imide group (hereinafter, sometimes referred to as a polyimide resin), a resin containing a repeating structural unit containing both an imide group and an amide group (hereinafter, sometimes referred to as a polyamideimide resin), and a precursor before the polyimide-based resin is produced by imidization. The precursor before the production of the polyimide resin is polyamic acid. In the present specification, a "repeating structural unit" may be referred to as a "structural unit". In addition, "a structural unit derived from …" may be simply referred to as "a unit", and for example, a structural unit derived from a compound may be referred to as a compound unit or the like.

In a preferred embodiment of the present invention, the polyimide resin (a) preferably has a structural unit represented by formula (1).

[ chemical formula 5]

[ in the formula (1), X represents a 2-valent organic group, Y represents a 4-valent organic group, and represents a connecting bond ]

Such a polyimide resin can easily reduce the CTE of the film and can easily improve mechanical properties such as heat resistance and bending resistance.

X in the formula (1) independently represents a 2-valent organic group, preferably a 2-valent organic group having 2 to 100 carbon atoms. Examples of the organic group having a valence of 2 include an aromatic group having a valence of 2 and an aliphatic group having a valence of 2, and examples of the aliphatic group having a valence of 2 include an acyclic aliphatic group having a valence of 2 and a cyclic aliphatic group having a valence of 2. Among them, from the viewpoint of easily lowering the CTE of the film and easily improving the heat resistance and mechanical properties, a cyclic aliphatic group having a valence of 2 and an aromatic group having a valence of 2 are preferable, and an aromatic group having a valence of 2 is more preferable. In the case of a 2-valent organic group, the hydrogen atom in the organic group may be substituted with a halogen atom, a hydrocarbon group, an alkoxy group or a halogenated hydrocarbon group, and in this case, the number of carbon atoms of these groups is preferably 1 to 8. In the present specification, the aromatic group having a valence of 2 is a 2-valent organic group having an aromatic group, and may contain an aliphatic group or other substituent in a part of the structure. The 2-valent aliphatic group is a 2-valent organic group having an aliphatic group, and may contain other substituents in a part of the structure thereof, but does not contain an aromatic group.

In one embodiment of the present invention, the polyimide-based resin (a) may contain a plurality of kinds of X, and the plurality of kinds of X may be the same as or different from each other. Examples of X in formula (1) include groups (structures) represented by formulae (2) to (8); and those obtained by substituting a hydrogen atom in the groups represented by formulae (5) to (8) with a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a fluoro group, a chloro group, or a trifluoromethyl group.

[ chemical formula 6]

[ formula (2) and formula (3) wherein R ^a And R ^b Independently represents a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, R ^a And R ^b The hydrogen atoms contained in (A) may be substituted independently of each other by a halogen atom, and W independently of each other represents a single bond, -O-, -CH ₂ -、-CH ₂ -CH ₂ -、-CH(CH ₃ )-、-C(CH ₃ ) ₂ -、-C(CF ₃ ) ₂ -、-COO-、-OOC-、-SO ₂ -, -S-, -CO-or-N (R) ^c )-，R ^c Represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom, n is an integer of 0 to 4, t is an integer of 0 to 4, and u is an integer of 0 to 4.

In the formula (4), the ring A represents a cycloalkane having 3 to 8 carbon atoms, and R ^d Represents an alkyl group having 1 to 20 carbon atoms, r represents an integer of 0 or more and (the carbon number of ring A is-2) or less, S1 and S2 independently represent an integer of 0 to 20, and represents a bond.]

Other examples of X in the formula (1) include 2-valent acyclic aliphatic groups such as ethylene, 1,3-propylene, 1,4-butylene, 1,5-pentylene, 1,6-hexylene, 1,2-propylene, 1,2-butanediyl, 1,3-butanediyl, 1,12-dodecanediyl, 2-methyl-1,2-propanediyl, and 2-methyl-1,3-propanediyl, which are linear or branched alkylene groups. The hydrogen atom in the 2-valent acyclic aliphatic group may be substituted with a halogen atom, and the carbon atom may be substituted with a hetero atom such as an oxygen atom, a nitrogen atom, or the like.

Among them, the polyimide-based resin (a) in the present invention preferably contains the structure represented by formula (2) and/or the structure represented by formula (3), and more preferably contains the structure represented by formula (2) as X in formula (1), from the viewpoint of high water absorption resistance, high dielectric characteristics, low CTE, high heat resistance, and high mechanical characteristics, which are easy to achieve film formation.

In the formulae (2) and (3), the linking bonds of the benzene rings or cyclohexane rings may be bonded to the ortho-position and the meta-position, respectively, based on-W-The site or para-site, or any of the α, β, or γ sites may be bonded preferably to the meta or para site, or the β or γ site, or more preferably to the para or γ site, from the viewpoint of facilitating reduction in the CTE of the film and facilitating improvement in the water absorption resistance, heat resistance, and mechanical properties. R ^a And R ^b Independently represents a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, a 2-methyl-butyl group, a 3-methylbutyl group, a 2-ethyl-propyl group, and an n-hexyl group. Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, a propyloxy group, an isopropyloxy group, a butoxy group, an isobutoxy group, a tert-butoxy group, a pentyloxy group, a hexyloxy group, and a cyclohexyloxy group. Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a tolyl group, a xylyl group, a naphthyl group, and a biphenyl group. R ^a And R ^b The hydrogen atoms contained in (a) may be independently substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among them, R is from the viewpoint of easily lowering the CTE of the film and easily improving the water absorption resistance, heat resistance and dielectric characteristics ^a And R ^b Independently of each other, an alkyl group having 1 to 6 carbon atoms or a fluoroalkyl group having 1 to 6 carbon atoms is preferable, an alkyl group having 1 to 3 carbon atoms or a fluoroalkyl group having 1 to 3 carbon atoms is more preferable, and a methyl group or a trifluoromethyl group is further preferable.

In the formulae (2) and (3), t and u are each independently an integer of 0 to 4, and from the viewpoint of facilitating reduction of the CTE of the film and improvement of heat resistance and mechanical properties, an integer of 0 to 2 is preferable, and 0 or 1 is more preferable.

In the formulae (2) and (3), W independently represents a single bond, -O-, -CH ₂ -、-CH ₂ -CH ₂ -、-CH(CH ₃ )-、-C(CH ₃ ) ₂ -、-C(CF ₃ ) ₂ -、-COO-、-OOC-、-SO ₂ -, -S-, -CO-or-N (R) ^c ) -, is easily loweredThe film preferably has a single bond, -O-, -CH-, and is preferably a single bond, from the viewpoint of easily improving the water absorption resistance, heat resistance, and mechanical properties, particularly the bending resistance ₂ -、-C(CH ₃ ) ₂ -、-C(CF ₃ ) ₂ -, -COO-, -OOC-or-CO-, more preferably represents a single bond, -O-, -CH ₂ -、-C(CH ₃ ) ₂ -or-C (CF) ₃ ) ₂ -。R ^c Represents a hydrogen atom, a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom. Examples of the 1-valent hydrocarbon group having 1 to 12 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, a 2-methyl-butyl group, a 3-methylbutyl group, a 2-ethyl-propyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, a tert-octyl group, an n-nonyl group, an n-decyl group and the like, which may be substituted with a halogen atom. Examples of the halogen atom include the same halogen atoms as described above.

In the formulae (2) and (3), n is an integer of 0 to 4, and is preferably an integer of 0 to 3, more preferably 1 or 2, from the viewpoint of easily lowering the CTE of the film and easily improving the water absorption resistance, heat resistance and mechanical properties. When n is 2 or more, a plurality of W, R ^a And t may be the same or different from each other, and the positions of the connecting bonds of the benzene rings based on-W-may be the same or different from each other.

When the polyimide-based resin (a) in the present invention contains both the structure represented by formula (2) and the structure represented by formula (3) as X in formula (1), W, n, R in formula (2) ^a 、R ^b T and u independently of one another may be identical to W, n, R in formula (3) ^a 、R ^b T and u may be the same or different.

In the formula (4), the ring A represents a cycloalkane having 3 to 8 carbon atoms. Examples of the cycloalkane include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane and cyclooctane, and preferred examples thereof include cycloalkanes having 4 to 6 carbon atoms. In ring a, the connecting bonds may or may not be adjacent to each other. For example, when the ring a is cyclohexane, the 2 linkages may be in the α -, β -or γ -position, and preferably in the β -or γ -position.

R in the formula (4) ^d Represents an alkyl group having 1 to 20 carbon atoms. Examples of the alkyl group having 1 to 20 carbon atoms include R ⁷ ～R ¹⁸ The alkyl group in the above examples, which is a hydrocarbon group having 1 to 20 carbon atoms, preferably represents an alkyl group having 1 to 10 carbon atoms. R in formula (4) represents an integer of 0 or more and 2 or less (the number of carbon atoms in ring A). r is 0 or more, preferably 4 or less. S1 and S2 in formula (4) independently represent an integer of 0 to 20. S1 and S2 are independently preferably 0 or more, more preferably 2 or more, and preferably 15 or less.

Specific examples of the structures represented by formulas (2) to (4) include structures represented by formulas (4') and (9) to (30). In these formulae, a represents a bond.

[ chemical formula 7]

In a preferred embodiment of the present invention, when the structure represented by formula (2) and/or formula (3) is contained as X in formula (1), the proportion of the structural unit represented by formula (2) and/or formula (3) in X in formula (1) is preferably 30mol% or more, more preferably 50mol% or more, further preferably 70mol% or more, particularly preferably 90mol% or more, and preferably 100mol% or less, relative to the total molar amount of the structural units represented by formula (1). When the ratio of the structural unit represented by formula (2) and/or formula (3) in X in formula (1) is in the above range, the CTE of the film is easily lowered, and the water absorption resistance, heat resistance, dielectric properties, and mechanical properties are easily improved. The proportion of the structural unit represented by formula (2) and/or formula (3) in Y in formula (1) can be determined, for example ¹ H-NMR, or calculated from the charge ratio of the raw materials.

In the formula (1), Y independently represents a 4-valent organic group, preferably a 4-valent organic group having 4 to 40 carbon atoms, and more preferably a 4-valent organic group having 4 to 40 carbon atoms and having a cyclic structure. Examples of the cyclic structure include alicyclic, aromatic ring, and heterocyclic structure. The hydrogen atom in the organic group may be substituted with a halogen atom, a hydrocarbon group, an alkoxy group or a halogenated hydrocarbon group, and in this case, the number of carbon atoms of these groups is preferably 1 to 8. The polyimide resin (a) in the present invention may contain a plurality of kinds of Y, and the plurality of kinds of Y may be the same or different. Examples of Y include groups (structures) represented by formulae (31) to (38); a group represented by formula (34) to formula (38) wherein the hydrogen atom is substituted with a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a fluoro group, a chloro group or a trifluoromethyl group; chain hydrocarbon groups having 1 to 8 carbon atoms and having a valence of 4.

[ chemical formula 8]

[ formula (31) to formula (33), R ¹⁹ ～R ²⁶ Independently of each other, represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, R ¹⁹ ～R ²⁶ The hydrogen atoms contained in (a) may be substituted independently of each other by halogen atoms,

V ¹ and V ² Independently of each other, represents a single bond, -O-, -CH ₂ -、-CH ₂ -CH ₂ -、-CH(CH ₃ )-、-C(CH ₃ ) ₂ -、-C(CF ₃ ) ₂ -、-COO-、-OOC-、-SO ₂ -、-S-、-CO-、-N(R ^j ) -, formula (a) or formula (b),

[ chemical formula 9]

/>

(in the formula (a), R ²⁷ ～R ³⁰ Independently of each other, a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and Z represents-C (CH) ₃ ) ₂ -or-C (CF) ₃ ) ₂ -, i is an integer of 1 to 3, which represents a bond)

R ^j Represents a hydrogen atom or may be substituted by a halogen atomE and d independently represent an integer of 0 to 2, f represents an integer of 1 to 3, g and h independently represent an integer of 0 to 4, and]

among them, from the viewpoint of easily lowering the CTE of the film and easily improving the heat resistance and mechanical properties, the polyimide-based resin in the present invention preferably contains at least 1 structure selected from the group consisting of the structure represented by formula (31), the structure represented by formula (32), and the structure represented by formula (33) as Y in formula (1), and more preferably contains the structure represented by formula (31).

In the formulae (31) to (33), R ¹⁹ ～R ²⁶ Independently of one another, a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms and the aryl group having 6 to 12 carbon atoms include the alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms and the aryl group having 6 to 12 carbon atoms exemplified above in the formulae (2) and (3), respectively. R ¹⁹ ～R ²⁶ The hydrogen atoms contained in (a) may be independently substituted with a halogen atom, and examples of the halogen atom include the halogen atoms exemplified above. Among them, R is from the viewpoint of easily improving the water absorption resistance, heat resistance and dielectric characteristics of the film ¹⁹ ～R ²⁶ Independently of each other, a hydrogen atom or an alkyl group having 1 to 6 carbon atoms is preferable, a hydrogen atom or an alkyl group having 1 to 3 carbon atoms is more preferable, and a hydrogen atom is further preferable.

In the formula (31), V ¹ And V ² Independently of each other, represents a single bond, -O-, -CH ₂ -、-CH ₂ -CH ₂ -、-CH(CH ₃ )-、-C(CH ₃ ) ₂ -、-C(CF ₃ ) ₂ -、-COO-、-OOC-、-SO ₂ -、-S-、-CO-、-N(R ^j ) The formula (a) or (b) preferably represents a single bond, -O-, -CH-, from the viewpoints of easy lowering of the CTE of the film and easy improvement of the water absorption resistance, heat resistance and mechanical properties ₂ -、-C(CH ₃ ) ₂ -、-C(CF ₃ ) ₂ -, -COO-, -OOC-or-CO-, more preferably represents a single bond、-O-、-C(CH ₃ ) ₂ -or-C (CF) ₃ ) ₂ -。R ^j Represents a hydrogen atom, a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom. Examples of the monovalent hydrocarbon group having 1 to 12 carbon atoms include those exemplified above.

In formula (31), e and d each independently represent an integer of 0 to 2, and are preferably 0 or 1, and more preferably e + d =1, from the viewpoint of facilitating reduction in the CTE of the film and improvement in heat resistance and mechanical properties.

In the formula (32), f represents an integer of 1 to 3, and is preferably 1 or 2, and more preferably 1, from the viewpoint of easily lowering the CTE of the film and easily improving the heat resistance and mechanical properties.

In formula (33), g and h independently represent an integer of 0 to 4, and from the viewpoint of facilitating reduction in the CTE of the film and facilitating improvement in heat resistance and mechanical properties, an integer of 0 to 2 is preferable, an integer of 0 or 1 is more preferable, and an integer of g + h =0 to 2 is even more preferable.

In the formula (a), R ²⁷ ～R ³⁰ Independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms include those exemplified above as the alkyl group having 1 to 6 carbon atoms in the formulae (2) and (3). Among them, R is considered to be easy to lower the CTE of the film and to improve the heat resistance and mechanical properties ²⁷ ～R ³⁰ Independently of each other, a hydrogen atom or an alkyl group having 1 to 3 carbon atoms is more preferable, and a hydrogen atom is further preferable.

In the formula (a), Z represents-C (CH) ₃ ) ₂ -or-C (CF) ₃ ) ₂ -. When Z has such a structure, water absorption resistance, heat resistance, dielectric properties, and mechanical properties of the film can be easily improved. i represents an integer of 1 to 3, and is preferably 1 or 2 from the viewpoint of easily lowering the CTE of the film and easily improving the water absorption resistance, heat resistance and mechanical properties. When i is 2 or more, plural Z and R ²⁷ ～R ³⁰ May be the same as or different from each other.

Specific examples of the structures represented by formulas (31) to (33) include structures represented by formulas (39) to (51). In these formulae, a represents a bond.

[ chemical formula 10]

In one embodiment of the present invention, when at least 1 selected from the group consisting of the structures represented by formulae (31) to (33) is contained as Y in formula (1), the proportion of the structural unit represented by at least 1 selected from the group consisting of the structures represented by formulae (31) to (33) in Y in formula (1) is preferably 30mol% or more, more preferably 50mol% or more, further preferably 70mol% or more, particularly preferably 90mol% or more, and preferably 100mol% or less, relative to the total molar amount of the structural units represented by formula (1). When the proportion of the structural unit represented by at least 1 selected from the group consisting of the structures represented by formulae (31) to (33) in Y in formula (1) is in the above range, the CTE of the film is easily lowered, and the water absorption resistance, heat resistance, dielectric properties, and mechanical properties are easily improved. The proportion of the structural unit represented by at least 1 selected from the group consisting of the structures represented by formulae (31) to (33) in Y in formula (1) may be, for example, used ¹ H-NMR, or the ratio of the raw materials charged may be calculated.

The polyimide-based resin (a) in the present invention may contain, in addition to the structural unit represented by formula (1), at least 1 selected from the group consisting of the structural unit represented by formula (52), the structural unit represented by formula (53), and the structural unit represented by formula (54).

[ chemical formula 11]

[ formula (52) and formula (53) wherein Y ¹ Represents a 4-valent organic group, and a salt thereof,

Y ² represents a 3-valent organic group, and a salt thereof,

X ¹ and X ² Independently of one another, represent a 2-valent organic group,

* Representing a connecting bond.

In the formula (54), G and X independently represent a 2-valent organic group,

* Representing a connecting bond. ]

In a preferred embodiment of the present invention, in the formulae (52) and (53), Y is ¹ Synonymous with Y in formula (1), X ¹ And X ² Is synonymous with X in the formula (1). Y in the formula (53) ² Preferred is a group in which any of the bonds of Y in formula (1) is replaced with a hydrogen atom. As Y ² Examples thereof include: a group in which any of the connecting bonds of the groups (structures) represented by the formulae (31) to (38) is replaced with a hydrogen atom; chain hydrocarbon groups having 1 to 8 carbon atoms and having a valence of 3. In one embodiment of the present invention, the polyimide-based resin may contain a plurality of kinds of Y ¹ Or Y ² Plural kinds of Y ¹ Or Y ² May be the same or different from each other.

In formula (54), G is independently a 2-valent organic group, preferably a 2-valent organic group having 2 to 100 carbon atoms which may be substituted with a hydrocarbon group having 1 to 8 carbon atoms or a fluorine-substituted hydrocarbon group having 1 to 8 carbon atoms, and more preferably a 2-valent organic group having 2 to 100 carbon atoms which may be substituted with a hydrocarbon group having 1 to 8 carbon atoms or a fluorine-substituted hydrocarbon group having 1 to 8 carbon atoms and has a cyclic structure. Examples of the cyclic structure include alicyclic, aromatic ring, and heterocyclic structure. Examples of the organic group of G include a group in which 2 nonadjacent bonds of the groups represented by formulae (31) to (38) are replaced with a hydrogen atom, and a 2-valent chain hydrocarbon group having 6 or less carbon atoms, and preferably include a group in which 2 nonadjacent bonds of the groups represented by formulae (39) to (51) are replaced with a hydrogen atom.

X in formula (54) is synonymous with X in formula (1), and when the polyimide-based resin includes the structural unit represented by formula (1) and the structural unit represented by formula (54), X in each structural unit may be the same or different. In one embodiment of the present invention, the polyimide-based resin may contain a plurality of X or G, and the plurality of X or G may be the same as or different from each other.

In one embodiment of the present invention, the polyimide-based resin (A)Comprises a structural unit represented by the formula (1) and, in some cases, at least 1 structural unit selected from the group consisting of a structural unit represented by the formula (52), a structural unit represented by the formula (53) and a structural unit represented by the formula (54). In the polyimide resin (a), the proportion of the structural unit represented by formula (1) is preferably 80mol% or more, more preferably 90mol% or more, and still more preferably 95mol% or more, based on the total molar amount of all the structural units contained in the polyimide resin, for example, the structural unit represented by formula (1), and in some cases, at least 1 structural unit selected from the structural unit represented by formula (52), the structural unit represented by formula (53), and the structural unit represented by formula (54). The upper limit of the proportion of the structural unit represented by the formula (1) in the polyimide resin (a) is 100mol% or less. The above ratio can be used, for example ¹ H-NMR, or the ratio of the raw materials charged may be calculated. The polyimide resin in the present invention is preferably a polyimide resin, because the CTE of the film is easily reduced and the water absorption resistance, heat resistance, and dielectric characteristics are easily improved.

In one embodiment of the present invention, the polyimide resin (a) in the present invention may contain a halogen atom, preferably a fluorine atom, which can be introduced by using, for example, the above-mentioned substituent containing a halogen atom. When the polyimide resin (a) contains a halogen atom, preferably a fluorine atom, the water absorption resistance, the heat resistance and the dielectric characteristics are easily improved, and the optical characteristics are also easily improved. Examples of the preferable fluorine-containing substituent for allowing the polyimide resin (a) to contain a fluorine atom include a fluorine group and a trifluoromethyl group.

When the polyimide resin (a) contains a halogen atom, the content of the halogen atom in the polyimide resin (a) is preferably 0.1 to 40% by mass, more preferably 1 to 35% by mass, and even more preferably 5 to 30% by mass, based on the mass of the polyimide resin. When the halogen atom content is not less than the lower limit, the water absorption resistance, heat resistance and dielectric characteristics of the film can be easily improved. When the content of the halogen atom is not more than the above upper limit, the CTE of the film can be reduced and the synthesis becomes easy.

The imidization ratio of the polyimide resin (a) is preferably 90% or more, more preferably 93% or more, further preferably 95% or more, and usually 100% or less. The imidization ratio is preferably not less than the above-described lower limit from the viewpoint of easily improving the dielectric characteristics, optical characteristics, and water absorption resistance of the film. The imidization ratio indicates a ratio of a molar amount of imide bonds in the polyimide-based resin to a value 2 times a molar amount of structural units derived from a tetracarboxylic acid compound in the polyimide-based resin. When the polyimide resin (a) contains a tricarboxylic acid compound, the imidization ratio indicates a ratio of a value of a molar amount of imide bonds in the polyimide resin to a value 2 times a molar amount of structural units derived from a tetracarboxylic acid compound in the polyimide resin to a total of the molar amounts of structural units derived from the tricarboxylic acid compound. The imidization ratio can be determined by an IR method, an NMR method, or the like.

The Tg of the polyimide resin (a) is preferably 100 ℃ or higher, more preferably 150 ℃ or higher, even more preferably 200 ℃ or higher, even more preferably 300 ℃ or higher, particularly preferably 350 ℃ or higher, and preferably 550 ℃ or lower. When the Tg of the polyimide resin (a) is not less than the above lower limit, the heat resistance of the resulting film is easily improved, and the CTE is easily lowered. When the Tg of the polyimide resin (a) is not more than the above upper limit, the mechanical properties are easily improved. The Tg of the polyimide resin (a) can be determined by, for example, performing dynamic viscoelasticity measurement (hereinafter, DMA measurement may be omitted), and can be measured by the method described in examples.

The Mw of the polyimide resin (a) is preferably 50,000 or more, more preferably 100,000 or more, more preferably 150,000 or more, further preferably 200,000 or more, further more preferably 250,000 or more, particularly preferably 300,000 or more, preferably 1,000,000 or less, more preferably 800,000 or less, further preferably 700,000 or less, further more preferably 500,000 or less, and particularly preferably 450,000 or less in terms of polystyrene conversion. When the Mw of the polyimide resin (a) is not less than the above lower limit, the water absorption resistance, heat resistance and mechanical properties of the resulting film can be easily improved, and the CTE can be easily reduced. When the Mw of the polyimide resin (a) is not more than the upper limit, moldability is easily improved. The Mw of the polyimide resin (a) can be determined by GPC measurement or conversion to standard polystyrene, for example, by the method described in examples.

As described above, the polyimide resin (a) in the present invention includes a precursor before imidization of the polyimide resin. When the polyimide resin (a) is a polyamic acid, the polyamic acid includes a structural unit represented by the formula (1').

[ in the formula (1'), Y and X represent Y and X in the formula (1), respectively ]

< method for producing polyimide resin (A) >

The method for producing the polyimide resin (a) is not particularly limited, and for example, it can be produced by a method including a step of reacting a diamine compound with a tetracarboxylic acid compound to obtain a polyamic acid, and a step of imidizing the polyamic acid. When the polyimide resin (a) is a polyamic acid, the step of obtaining a polyamic acid may be performed. In addition to the tetracarboxylic acid compound, a dicarboxylic acid compound or a tricarboxylic acid compound may be reacted.

Examples of the tetracarboxylic acid compound used for the synthesis of the polyimide resin (a) include aromatic tetracarboxylic acid compounds such as aromatic tetracarboxylic acid dianhydride; and aliphatic tetracarboxylic acid compounds such as aliphatic tetracarboxylic dianhydride. The tetracarboxylic acid compound may be used alone or in combination of 2 or more. The tetracarboxylic acid compound may be a tetracarboxylic acid compound analog such as an acid chloride compound, other than the dianhydride.

<xnotran> , (, PMDA), '- (' - ) (, BPADA), - , ',' - (, BPDA), '- ( ) (, 6 FDA),' - (, ODPA), ',' -, ',4' - ',' - , ',' - , ',' - , ',' - , (- ) , "," -, ",4" - "," - , - (- - ) - , (- - ) , - (- - ) , -, - - , - (- ) , - (, HPMDA), - , </xnotran> 2,3,6,7-Naphthalenetetracarboxylic dianhydride, 1,2,5,6-Naphthalenetetracarboxylic dianhydride, cyclopentane-1,2,3,4-Tetracarboxylic dianhydride, 4,4 '-bis (2,3-dicarboxyphenoxy) diphenylmethane dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride (hereinafter, sometimes abbreviated as CBDA), norbornane-2-spiro- α' -spiro-2 ″ -norbornane-5,5 ',6,6' -tetracarboxylic anhydride, p-phenylene bis (trimellitic anhydride), 3,3',4,4' -diphenylsulfone tetracarboxylic dianhydride, 4,4-anthracenetetracarboxylic dianhydride, 4,4-dimethyl-4,4-hexahydronaphthalene-4,4-tetracarboxylic dianhydride, 4,4-or 4,4-dichloronaphthalene-4,4-tetracarboxylic dianhydride, 4,4- (or 4,4-) tetrachloronaphthalene-4,4- (or 4,4-) tetracarboxylic dianhydride, 4,4-, or 4,4-perylenetetracarboxylic dianhydride, pyrazine-4,4-tetracarboxylic dianhydride, pyrrolidine-4,4-tetracarboxylic dianhydride, thiophene-6258-zxft 6258-tetracarboxylic dianhydride, 6258-bis-4,4-phenylsulfone dianhydride, and the like. Among them, PMDA, BPDA, 6FDA, BPADA, ODPA, HPMDA, CBDA, and p-phenylene bis (trimellitic anhydride) are preferable from the viewpoint of easily lowering the CTE of the film and easily improving the water absorption resistance, heat resistance, dielectric properties, and mechanical properties. These tetracarboxylic acid compounds may be used alone or in combination of two or more.

Examples of the diamine compound used for the synthesis of the polyimide resin (a) include aliphatic diamines, aromatic diamines, and mixtures thereof. In this embodiment, the "aromatic diamine" refers to a diamine having an aromatic ring, and may contain an aliphatic group or other substituent in a part of the structure thereof. The aromatic ring may be a monocyclic ring or a fused ring, and examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, a fluorene ring and the like, but are not limited thereto. Among them, benzene ring is preferable. The term "aliphatic diamine" means a diamine having an aliphatic group, which may contain other substituents in a part of the structure thereof, but does not have an aromatic ring.

Specific examples of the diamine compound include 1,4-diaminocyclohexane, 4,4 '-diamino-2,2' -dimethylbiphenyl (hereinafter, sometimes referred to as m-TB), 4,4 '-diamino-3,3' -dimethylbiphenyl, 2,2 '-bis (trifluoromethyl) -4,4' -diaminobiphenyl (hereinafter, sometimes referred to as TFMB), 4,4 '-diaminodiphenyl ether, 1,3-bis (3-aminophenoxy) benzene (hereinafter, sometimes referred to as 1,3-APB), 1,4-bis (4-aminophenoxy) benzene (hereinafter, sometimes abbreviated as 1,4-APB), 1,3-bis (4-aminophenoxy) benzene, 2,2' -bis [4- (4-aminophenoxy) phenyl ] propane (hereinafter sometimes referred to as BAPP), 2,2 '-dimethyl-4,4' -diaminobiphenyl, 3,3 '-dihydroxy-4,4' -diaminobiphenyl, 2,2-bis- [4- (3-aminophenoxy) phenyl ] propane, bis [4- (4-aminophenoxy) ] biphenyl, bis [4- (3-aminophenoxy) biphenyl, bis [1- (4-aminophenoxy) ] biphenyl, bis [1- (3-aminophenoxy) ] biphenyl, bis [4- (4-aminophenoxy) phenyl ] methane, bis [4- (3-aminophenoxy) phenyl ] methane, bis [4- (4-aminophenoxy) phenyl ] ether, bis [4- (3-aminophenoxy) phenyl ] ether, bis [4- (4-aminophenoxy) ] benzophenone, bis [4- (3-aminophenoxy) ] benzophenone, 2,2-bis- [4- (4-aminophenoxy) phenyl ] hexafluoropropane, 2,2-bis- [4- (3-aminophenoxy) phenyl ] hexafluoropropane, 4,4 '-methylenedi-o-toluidine, 4,4' -methylenedi-2,6-xylidine, 4,4 '-methylenedi-2,6-diethylaniline, 4,4' -methylenedianiline, 3,3 '-methylenedianiline, 4,4' -diaminodiphenylpropane, 5678 '-diaminodiphenylpropane, 7439' -diaminodiphenylethane, 8624 '-methylenediphenyl-359692' -diaminodiphenylethane, p-429635 '-diaminodiphenylethylene-429635' -diaminodiphenylene ether, and a bis- (3 '-diaminodiphenyl-429635' -methylenediphenyl-359635 '-methylenediphenyl-429635' -triphenylmethane, bis (p-aminocyclohexyl) methane, bis (p- β -amino-t-butylphenyl) ether, bis (p- β -methyl- δ -aminopentyl) benzene, p-bis (2-methyl-4-aminopentyl) benzene, p-bis (1,1-dimethyl-5-aminopentyl) benzene, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,4-bis (β -amino-t-butyl) toluene, 2,4-diaminotoluene, m-xylene-2,5-diamine, p-xylene-2,5-diamine, m-xylylenediamine, p-xylylenediamine, piperazine, 4,4 '-diamino-2,2' -bis (trifluoromethyl) bicyclohexane, 4,4, p-dicyclohexylmethane 4,4 '-diaminop-terphenyl, bis (4-aminophenyl) terephthalate, 1,4-bis (4-aminophenoxy) -2,5-di-tert-butylbenzene, 4,4' - (1,3-phenylenediisopropylidene) dianiline, 1,4-bis [2- (4-aminophenyl) -2-propyl ] benzene, 2,4-diamino-3,5-diethyltoluene, 2,6-diamino-3,5-diethyltoluene, 4,4 '-bis (3-aminophenoxy) biphenyl, 4,4' - (hexafluoropropylidene) diphenylamine, 1,2-diaminoethane, 1,3-diaminopropane, 58 zxft 6258-diaminobutane 3558, 1,5 diaminopentane, 1,6 diaminohexane, 1,2 diaminopropane, 1,2 diaminobutane, 1,3 diaminobutane, 2-methyl-1,2 diaminopropane, 2-methyl-1,3 diaminopropane, 1,3 bis (aminomethyl) cyclohexane, 1,4 bis (aminomethyl) cyclohexane, norbornane diamine, 2' -methoxy-4,4 ' -diaminobenzanilide, 4,4' -diaminobenzanilide, bis [4- (4-aminophenoxy) phenyl ] sulfone, bis [4- (3-aminophenoxy) phenyl ] sulfone 9,9-bis [4- (4-aminophenoxy) phenyl ] fluorene, 9,9-bis [4- (3-aminophenoxy) phenyl ] fluorene, 4,4' -diaminodiphenyl sulfide, 3,3' -diaminodiphenyl sulfide, 4,4' -diaminodiphenyl sulfone, 3,3' -diaminodiphenyl sulfone, 2,5-diamino-1,3,4-oxadiazole, bis [4,4' - (4-aminophenoxy) ] benzanilide, bis [4,4' - (3-aminophenoxy) ] benzanilide, 2,6-diaminopyridine, 2,5-diaminopyridine, and the like. Among them, 1,4-diaminocyclohexane, 4,4 '-diaminodiphenyl ether, TFMB, 4,4' -methylenedianiline, 3,3 '-methylenedianiline, p-PDA, BAPP, 4,4' -diaminodicyclohexylmethane, 4,4 '-diamino-2,2' -bis (trifluoromethyl) bicyclohexane, m-TB, 4,4 "-diaminop-terphenyl, bis (4-aminophenyl) terephthalate, 1,4-bis (4-aminophenoxy) -2,5-di-tert-butylbenzene, 1,3-APB, 3428 zxft 6528-APB, resorcinol-bis (3-aminophenyl) ether, 3476 zxft 6595-di-tert-butylbenzene, 6828-zxft 3726-diethylpropylidene [ 3-3534-zxft ] phenylene, bis (3-aminopropyl) 3527-3625-propyl-bis (3527-3-3625-zxft-phenyl) diphenylamine, 3427-bis (3-aminopropylidene) triphenylidene) benzene, 3427-bis (3-3534-zxft 3-propyl-3-bis (3-3625-zxft 3-3625-propyl-3625-3-phenyl) diphenylamine, 3452, etc. are preferable. The diamine compound may be used alone or in combination of two or more.

The polyimide resin (a) may be a resin obtained by further reacting other tetracarboxylic acids, dicarboxylic acids, tricarboxylic acids, anhydrides thereof, and derivatives thereof in addition to the tetracarboxylic acid compound used for the resin synthesis, within a range that does not impair various physical properties of the film.

Examples of the other tetracarboxylic acid include water adducts of anhydrides of the above tetracarboxylic acid compounds.

Examples of the dicarboxylic acid compound include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and the like, and acid chloride compounds and acid anhydrides thereof, and 2 or more of them may be used alone or in combination. Specific examples thereof include terephthalic acid; isophthalic acid; naphthalenedicarboxylic acid; 4,4' -biphenyldicarboxylic acid; 3,3' -biphenyldicarboxylic acid; dicarboxylic acid compound of chain hydrocarbon having 8 or less carbon atomsAnd 2 benzoic acids via a single bond, -O-, -CH ₂ -、-C(CH ₃ ) ₂ -、-C(CF ₃ ) ₂ -、-SO ₂ -or phenylene group-linked compounds, and acid chloride compounds thereof.

Examples of the tricarboxylic acid compound include aromatic tricarboxylic acids, aliphatic tricarboxylic acids, and similar acid chloride compounds and acid anhydrides thereof, and 2 or more of them may be used alone or in combination. Specific examples thereof include an anhydride of 1,2,4-benzenetricarboxylic acid; 2,3,6-naphthalene tricarboxylic acid-2,3-anhydride; phthalic anhydride and benzoic acid through single bond, -O-, -CH ₂ -、-C(CH ₃ ) ₂ -、-C(CF ₃ ) ₂ -、-SO ₂ -or phenylene groups.

In the production of the polyimide-based resin (a), the amounts of the diamine compound, the tetracarboxylic acid compound, the dicarboxylic acid compound and the tricarboxylic acid compound to be used may be appropriately selected depending on the ratio of each structural unit of the desired resin.

In a preferred embodiment of the present invention, the diamine compound is used in an amount of preferably 0.94mol or more, more preferably 0.96mol or more, further preferably 0.98mol or more, particularly preferably 0.99mol or more, preferably 1.20mol or less, more preferably 1.10mol or less, further preferably 1.05mol or less, particularly preferably 1.02mol or less, based on 1mol of the tetracarboxylic acid compound. When the amount of the diamine compound used is within the above range with respect to the tetracarboxylic acid compound, the CTE of the resulting film is easily lowered, and the water absorption resistance, heat resistance, dielectric properties, mechanical properties, and optical properties are easily improved.

The reaction temperature of the diamine compound and the tetracarboxylic acid compound is not particularly limited, and may be, for example, 5 to 200 ℃ or the reaction time may be, for example, about 30 minutes to 72 hours. In a preferred embodiment of the present invention, the reaction temperature is preferably 5 to 50 ℃, more preferably 10 to 40 ℃ and the reaction time is preferably 3 to 24 hours. When the reaction temperature and the reaction time are set as described above, the CTE of the obtained film is easily lowered, and the water absorption resistance, the heat resistance, the dielectric property, the mechanical property, and the optical property are easily improved.

The reaction of the diamine compound with the tetracarboxylic acid compound is preferably carried out in a solvent. The solvent is not particularly limited as long as it does not affect the reaction, and examples thereof include alcohol solvents such as water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, 1-methoxy-2-propanol, 2-butoxyethanol, and propylene glycol monomethyl ether; phenol solvents such as phenol and cresol; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ -butyrolactone (hereinafter, sometimes referred to as GBL), γ -valerolactone, propylene glycol methyl ether acetate, and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane, and heptane; alicyclic hydrocarbon solvents such as ethylcyclohexane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorine-containing solvents such as chloroform and chlorobenzene; amide solvents such as N, N-dimethylacetamide (hereinafter sometimes referred to as DMAc) and N, N-dimethylformamide (hereinafter sometimes referred to as DMF); sulfur-containing solvents such as dimethyl sulfone, dimethyl sulfoxide and sulfolane; carbonate solvents such as ethylene carbonate and propylene carbonate; pyrrolidone-based solvents such as N-methylpyrrolidone (hereinafter, sometimes abbreviated as NMP); combinations thereof, and the like. Among them, a phenol-based solvent, an amide-based solvent, and a pyrrolidone-based solvent can be preferably used from the viewpoint of solubility.

The reaction of the diamine compound with the tetracarboxylic acid compound can be carried out under an inert atmosphere such as a nitrogen atmosphere or an argon atmosphere or under reduced pressure as necessary, and for example, it is preferably carried out under an inert atmosphere such as a nitrogen atmosphere or an argon atmosphere while stirring in a strictly controlled dehydration solvent.

In the imidization step, imidization may be performed using an imidization catalyst, or imidization may be performed by heating, or a combination thereof may be used. Examples of the imidization catalyst used in the imidization step include aliphatic amines such as tripropylamine, dibutylpropylamine, and ethyldibutylamine; n-ethylpiperidine, N-propylpiperidine, N-butylpyrrolidine, N-butylpiperidine, and N-propylhexahydroazepino

Alicyclic amines (monocyclic); azabicyclo [2.2.1]Heptane, azabicyclo [3.2.1]Octane, azabicyclo [2.2.2]Octane, and azabicyclo [3.2.2 ]]Alicyclic amines (polycyclic type) such as nonane; and aromatic amines such as pyridine, 2-methylpyridine (2-picoline), 3-methylpyridine (3-picoline), 4-methylpyridine (4-picoline), 2-ethylpyridine, 3-ethylpyridine, 4-ethylpyridine, 2,4-dimethylpyridine, 2,4,6-trimethylpyridine, 3,4-cyclopentenopyridine, 5,6,7,8-tetrahydroisoquinoline, and isoquinoline. In addition, from the viewpoint of facilitating the imidization reaction, it is preferable to use an acid anhydride together with an imidization catalyst. Examples of the acid anhydride include common acid anhydrides used in the imidization reaction, and specific examples thereof include aliphatic acid anhydrides such as acetic anhydride, propionic anhydride, and butyric anhydride, and aromatic acid anhydrides such as phthalic acid. The imidization step by heating may be performed in a solvent in which the polyamic acid is dissolved, or may be performed in a film-formed state as described later.

In one embodiment of the present invention, when imidization is performed, the reaction temperature is usually 20 to 250 ℃ and the reaction time is preferably 30 minutes to 24 hours, more preferably 1 to 12 hours.

The polyimide resin (a) can be separated by separation and purification by a common method, for example, separation means such as filtration, concentration, extraction, crystallization, recrystallization, and column chromatography, or separation means combining these, and in a preferred embodiment, the resin can be separated by precipitating a large amount of an alcohol such as methanol into a reaction solution containing the resin, and then concentrating, filtering, and drying the resin.

< film >

The film of the present invention comprises a polyimide resin (a) and a particulate polymer (B), and has excellent water absorption resistance because the brightness of the film is 37 or less on both sides of the film when the haze is 75% or less, and the brightness of the film is 80 or less on both sides of the film when the haze is more than 75%. The film of the present invention has excellent water absorption resistance, and as a result, the dielectric characteristics of the film can be improved. The film of the present invention also has excellent smoothness of the film surface. Therefore, the film of the present invention can have excellent water absorption resistance, dielectric properties, and surface smoothness at the same time.

In the film of the present invention according to one embodiment of the present invention, the distance between the HSP values of the polyimide resin (a) and the polymer (B) is preferably 6 or more.

The HSP is the hansen solubility parameter (δ), defined as a three-dimensional parameter of (δ D, δ P, δ H), and is represented by formula (X).

δ ² ＝(δD) ² +(δP) ² +(δH) ² ···(X)

[ in the formula (X), δ D represents London dispersion force term, δ P represents molecular polarization term (dipole force term), and δ H represents hydrogen bond term ]

Details concerning HSP's are described in "PROPERTIES OF POLYMERS" (author: D.W. VANKREVELEN, press: ELSEVIER SCIENTFIC PUBLISHING COMPANY, 5 th edition, 1989). δ D, δ P, and δ H of Hansen Solubility Parameters can be calculated using HSPiP (Hansen Solubility Parameters in Practice), which is a program developed by a team of Hansen doctors who propose Hansen Solubility Parameters, and for example, ver.4.1.07 or the like can be used. The hansen lyosphere method will be described in detail below. A target component is dissolved in a solvent having a known HSP value, and the solubility of the component in a specific solvent is evaluated. The solubility was evaluated by visually judging whether or not the target components were dissolved in the solvent. This evaluation was performed for a variety of solvents. The solvent having a large difference in δ t is preferably used for the kind of the solvent, and more specifically, 10 or more, more preferably 15 or more, and still more preferably 18 or more kinds are used. Next, the central coordinates (δ d, δ p, δ h) of Hansen (Hansen) beads obtained by inputting the obtained evaluation result of solubility to HSPiP were set as HSP of the target composition. In addition to the above-described method, HSP may be obtained from a structural formula using HSPiP, for example, using numerical values and literature values of a database of HSPiP. In the present specification, the value of the hansen solubility parameter is referred to as an HSP value, and the HSP value indicates a value at 25 ℃. The HSP value of the polyimide resin (a), the HSP value of the polymer (B), and the HSP value of the solvent can be determined by any of the methods described above, and can be determined by the methods described in examples, for example.

The distance between hansen solubility parameters (hereinafter sometimes abbreviated as HSP) of two substances is referred to as the distance between HSP values. The inter-HSP distance (Ra) is an index indicating the affinity between two substances, and a smaller value indicates a higher affinity between two substances. Conversely, a larger value of Ra means that the two substances have a lower affinity, i.e., are less soluble.

For the distance between HSP values, if it is assumed that the hansen solubility parameters δ a and δ B of each of the two substances a and B are:

δA＝(δDA，δPA，δHA)

δB＝(δDB，δPB，δHB)

the inter-HSP distance (Ra) can be calculated using formula (Y).

Ra＝[4×(δDA-δDB) ² +(δPA-δPB) ² +(δHA-δHB) ² ] ^0.5 ···(Y)

In the present specification, the HSP value and the distance between HSP values can be determined by the above-described method, as defined above.

In a preferred embodiment of the present invention, the film of the present invention has excellent mechanical properties such as water absorption resistance, heat resistance and bending resistance and dielectric properties even when the distance between the HSP values of the polyimide resin (a) and the polymer (B) is large, and the CTE can be reduced. Therefore, in the film of the present invention, the distance between the HSP values between the polyimide resin (a) and the polymer (B) is preferably 6.0 or more, more preferably 7.0 or more, and still more preferably 8.0 or more.

In addition, from the viewpoint of affinity between the resin and the polymer, the distance between the HSP values of the polyimide resin (a) and the polymer (B) is preferably 30 or less, more preferably 25 or less, even more preferably 20 or less, and even more preferably 15 or less.

In one embodiment of the present invention, the total mass of the polyimide resin (a) and the particulate polymer (B) contained in the film is preferably 40% by mass or more, more preferably 60% by mass or more, still more preferably 80% by mass or more, particularly preferably 90% by mass or more, and preferably 100% by mass or less, relative to the mass of the film. When the total mass of the polyimide-based resin (a) and the particulate polymer (B) contained in the film is not less than the lower limit, the water absorption resistance, dielectric properties, and surface smoothness of the film are easily improved.

In a preferred embodiment of the present invention, the film of the present invention is preferably a composite film in which the particulate polymer (B) is dispersed, preferably uniformly dispersed, in the polyimide resin (a). For example, the composite film preferably has a sea-island structure, the polyimide resin (a) is sea, and the particulate polymer (B) is island. Such a composite film is easy to improve mechanical properties such as water absorption resistance, heat resistance, and bending resistance, and dielectric properties, and to lower the CTE. When the distance between the HSP values of the polyimide resin (a) and the polymer (B) is not less than the lower limit, the particulate polymer (B) can be easily and uniformly dispersed in the film, and a film having excellent water absorption resistance can be obtained.

In one embodiment of the invention, the films of the invention can have a low CTE. The CTE of the film may be designed appropriately according to the application. In the case of producing a CCL by laminating a copper foil, the CTE of the film is preferably adjusted to about 20ppm/K from the viewpoint of preventing peeling of the laminated film. The CTE of the film can be adjusted by the CTE, the amount of the particulate polymer (B) to be mixed, and the like of the polyimide resin (a). From the viewpoint of lowering the CTE, it is preferable to mix a particulate polymer (B) having a high Tg. The CTE can be measured by TMA, for example, by the method described in examples.

The water absorption resistance of the film of the present invention can be evaluated by the water absorption of the film. In one embodiment of the present invention, the water absorption of the film of the present invention is preferably 1% or less, more preferably 0.8% or less, further preferably 0.6% or less, further more preferably 0.5% or less, and particularly preferably 0.3% or less. If the water absorption rate of the film is not more than the upper limit, the film can have excellent water absorption resistance. Therefore, when the water absorption of the film is not more than the upper limit, the dielectric characteristics are easily improved and the dielectric loss and the transmission loss are easily suppressed when the film of the present invention is used for the resin layer of the CCL. The water absorption of the film of the present invention may be usually 0.01% or more. The water absorption of the film of the present invention can be determined by exposing the film to water vapor for a certain period of time and measuring the mass of the film before and after the water vapor exposure, and can be measured, for example, by the method described in examples.

In one embodiment of the present invention, the film of the present invention can have excellent surface smoothness. The surface smoothness of the film was evaluated by the standard deviation of the average thickness obtained in 10 measurement regions obtained by dividing the area of 1mm in a straight line on the film surface into ten parts. In one embodiment of the present invention, the standard deviation of the average thickness of the film of the present invention is preferably 2.5 or less, more preferably 2.0 or less, further preferably 1.70 or less, further more preferably 1.50 or less, particularly preferably 1.0 or less, particularly preferably 0.8 or less, and particularly preferably 0.5 or less. When the standard deviation of the average thickness is equal to or less than the upper limit described above, the surface smoothness of the film can be further improved, and therefore, for example, when the film is used as a resin layer of CCL, it is easy to achieve high processing accuracy in densification and miniaturization of wiring, and it is easy to suppress peeling between the film and the copper foil. The lower limit of the standard deviation of the average thickness is usually 0.01 or more, preferably 0.05 or more, more preferably 0.1 or more, and further preferably 0.2 or more. When the standard deviation of the average thickness is not less than the above lower limit, when the copper foil is bonded with an adhesive or the like, for example, the anchoring effect is easily utilized to improve the adhesion. The standard deviation of the average thickness of the film can be found by: an area of 1mm in a continuous straight line on the film surface was arbitrarily selected, and this area was divided into ten equal parts to set 10 measurement areas, and then the average thickness in each of the 10 measurement areas was measured using a contact or non-contact film thickness meter, a level difference meter, a surface shape measuring instrument, or the like, and the standard deviation of the average thickness in each of the obtained measurement areas was calculated. For example, the method can be determined by the method described in examples. The average thickness in each measurement region may be an average value calculated from a plurality of thicknesses measured at arbitrary points in the measurement region.

The film of the present invention may contain additives as needed. Examples of the additives include antioxidants, flame retardants, crosslinking agents, surfactants, compatibilizers, imidization catalysts, weather resistant agents, lubricants, antiblocking agents, antistatic agents, anti-clouding agents, non-dropping agents, pigments, and fillers. The additives may be used alone or in combination of two or more.

In one embodiment of the present invention, the film of the present invention exhibits high particle dispersibility even without containing a compatibilizing agent, and therefore can exhibit high water absorption resistance, low variation in thermal conductivity, low CTE, high heat resistance, and high mechanical properties. Therefore, in the film of the present invention, the content of the compatibilizer is preferably 5 parts by mass or less, more preferably 1 part by mass or less, further preferably 0.1 part by mass or less, further more preferably less than 0.1 part by mass, particularly preferably 0.05 part by mass or less, particularly preferably 0.01 part by mass or less, particularly preferably 0.001 part by mass or less, and most preferably 0 part by mass, per 100 parts by mass of the polyimide resin (a). In addition, for example, when the polyimide resin (a) is a precursor of a polyimide resin such as polyamic acid and thermal imidization is required in producing a film, the content of the compatibilizing agent is preferably less than 0.1 part by mass in the above range from the viewpoint of preventing inhibition of imidization by the compatibilizing agent and deterioration of film properties due to deterioration of the compatibilizing agent by heating. The content of the compatibilizer may be a content based on 100 parts by mass of the total of the polyimide resin (a) and the particulate polymer (B) in place of 100 parts by mass of the polyimide resin (a).

The thickness of the film of the present invention may be appropriately selected depending on the application, and is preferably 5 μm or more, more preferably 10 μm or more, further preferably 20 μm or more, preferably 500 μm or less, more preferably 300 μm or less, further preferably 100 μm or less, and particularly preferably 80 μm or less. The thickness of the film can be measured using a film thickness meter or the like, and can be measured, for example, by the method described in examples. When the film of the present invention is a multilayer film, the thickness represents an average thickness of a single layer portion.

The film of the present invention may be a single-layer film, or may be a multilayer film comprising at least 1 layer formed of the film of the present invention. The multilayer film may comprise other layers (or other films). In such a case, all layers are also included and referred to as the film of the present invention. Examples of the other layer include a functional layer and the like. Examples of the functional layer include an undercoat layer, a gas barrier layer, an adhesive layer, and a protective layer. The functional layers may be used alone or in combination of two or more.

The film of the present invention may be subjected to surface treatment such as corona discharge treatment, flame treatment, plasma treatment, ozone treatment, and the like by a method generally used industrially.

The film according to one embodiment of the present invention is excellent in water absorption resistance and dielectric characteristics. Therefore, the present invention can be suitably used for a printed circuit board for high-frequency band, a substrate material for an antenna substrate, and the like. For example, the CCL has a structure in which copper foils are laminated on both surfaces of a resin layer with an adhesive interposed therebetween. When the film of the present invention is used as the resin layer, the film has excellent water absorption resistance and a small dielectric loss, and thus can reduce transmission loss. When the film of the present invention is used as the resin layer, the surface smoothness is high and the CTE is reduced, so that the peeling between the copper foil and the resin layer can be effectively suppressed as compared with the conventional resin layer. Further, since mechanical properties, particularly bending resistance, are excellent, resistance to plastic deformation is high, and a winding mark is not easily generated.

Further, the film of the present invention can be suitably used for industrial materials such as automobile parts, electric and electronic parts, and the like; optical materials such as lenses, prisms, optical fibers, and recording media.

[ method for producing film ]

The film of the present invention can be produced by a method including, for example, the following steps:

(a) A composition preparation step of preparing a composition containing a polyimide resin (A), a particulate polymer (B) and a solvent;

(b) A coating step of applying the composition to a substrate to form a coating film; and

(c) And a film formation step of drying the applied liquid (coating film) to form a film.

When the thermal imidization of the polyimide resin (a) is performed, a step of terminating the imidization reaction may be included.

< preparation Process of composition >

The composition comprises a polyimide resin (A), a particulate polymer (B), a solvent, and, if necessary, the additive. The composition can be prepared or produced by, for example, mixing the polyimide resin (a), the particulate polymer (B), the solvent, and any of the above additives, but is preferably produced by the following method from the following viewpoints: the dispersibility of the particulate polymer (B) in the obtained film is improved, and when the haze is 75% or less, the brightness is easily adjusted to 37 or less on both sides of the film, and when the haze is more than 75%, the brightness is easily adjusted to 80 or less on both sides of the film, and as a result, a film having excellent water absorption resistance is easily obtained.

In a preferred embodiment of the present invention, the method for producing the composition of the present invention comprises the steps of:

a step (1) of dissolving a polymer (B) in a 1 st solvent to obtain a polymer (B) solution;

a step (2) of bringing the polymer (B) solution into contact with a solvent (2) and then distilling off the solvent (1) to obtain a dispersion liquid containing the particulate polymer (B) (hereinafter, sometimes referred to as a particulate polymer (B) dispersion liquid); and

a step (3) of adding a polyimide resin (A) to the dispersion of the particulate polymer (B).

When such a production method is used, aggregation of the polymer (B) particles can be suppressed, and thus the particle diameter is easily reduced and the dispersibility is easily improved. Therefore, a film having high water absorption resistance, surface smoothness and high mechanical properties can be easily obtained. In addition, when such a production method is used, the brightness of the obtained film is easily reduced.

The step (1) is a step of dissolving the polymer (B) in the 1 st solvent to obtain a polymer (B) solution. The form of the polymer (B) dissolved in the 1 st solvent is not particularly limited. The 1 st solvent is not particularly limited as long as the polymer (B) is soluble, and examples thereof include hydrocarbon solvents such as benzene, toluene, pentane, hexane, heptane, cyclohexane, xylene, and the like; halogenated hydrocarbon solvents such as methylene chloride and dichloroethane. Among them, a hydrocarbon solvent is preferable. When the 1 st solvent contains a hydrocarbon-based solvent, the solubility of the polymer (B) and the 1 st solvent is high, and therefore, the particle diameter of the particulate polymer (B) is easily reduced and the dispersibility is easily improved. As a result, a film having low brightness, high water absorption resistance, a smooth surface, high particle dispersibility, high heat resistance, high mechanical properties, and a low CTE can be easily obtained (hereinafter, the description of the "as a result" and subsequent effects may be omitted). The 1 st solvent may be used alone or in combination of two or more.

As described above, the 1 st solvent is a solvent in which the polymer (B) is soluble. In the present specification, the evaluation of "dissolution" or "insolubilization" may be performed according to the method described in < evaluation of solubility > in examples.

In one embodiment of the present invention, the distance between the HSP values of the 1 st solvent and the polymer (B) is preferably 4.0 or less, more preferably 3.0 or less, and further preferably 2.5 or less. When the distance between HSP values is not more than the above upper limit, the solubility of the 1 st solvent and the polymer (B) is increased, and therefore, the particle diameter of the particulate polymer (B) is easily decreased and the dispersibility is easily improved. The lower limit of the distance between HSP values is typically greater than 0.

In one embodiment of the present invention, it is preferable that the distance between the HSP value of the 1 st solvent and the polymer (B) is smaller than the interaction radius of the polymer (B). In this relation, the polymer (B) is easily dissolved in the 1 st solvent, and thus the particle diameter of the particulate polymer (B) is easily reduced and the dispersibility is easily improved. In the present specification, the interaction radius refers to the radius of a hansen-soluble sphere, which is a sphere in which the plotted points of good solvents tend to be spherically aggregated at the coordinates, which are positions similar to each other, that is, positions close to each other, when hansen-solubility parameters of good solvents, which are a plurality of solvents capable of dissolving a specific polymer, are plotted in a three-dimensional HSP space. It can be said that a solute having a large interaction radius is easily soluble in most solvents, and a solute having a small interaction radius is easily soluble in few solvents but hardly soluble in most solvents. For an unknown specific polymer, a solubility test was performed to investigate whether each solvent was a good solvent or a poor solvent, and the results were input to HSPiP to calculate the interaction radius of the polymer. Hereinafter, in the present specification, the "interaction radius" can be obtained by the above-described method, as defined above.

In one embodiment of the present invention, the 1 st solvent is preferably a solvent in which the polyimide resin (a) is insoluble. Such a solvent makes it easy to reduce the particle diameter of the particulate polymer (B) and to improve the dispersibility.

In one embodiment of the present invention, the distance between the HSP values between the 1 st solvent and the polyimide-based resin (a) is preferably 5.0 or more, more preferably 6.0 or more, still more preferably 7.0 or more, still more preferably 8.0 or more, and particularly preferably 9.0 or more. When the distance between HSP values is not less than the lower limit, the polyimide resin (a) is hardly soluble in the 1 st solvent, so that the formation of aggregates of the particulate polymer (B) is easily suppressed, and the particle diameter is easily reduced, thereby easily improving the dispersibility. In addition, the mechanical properties such as surface smoothness, particle dispersibility, heat resistance, water absorption resistance, and bending resistance of the obtained film are easily improved, and the CTE is easily lowered. The upper limit of the distance between the HSP value of the 1 st solvent and the polyimide resin (a) is preferably 30.0 or less, more preferably 27 or less, still more preferably 25 or less, still more preferably 23 or less, and particularly preferably 21 or less. When the distance between the HSP values of the 1 st solvent and the polyimide resin (a) is not more than the upper limit, aggregation of the particulate polymer (B) is easily suppressed, and therefore, the dispersibility of the particles is easily improved, and the dispersibility of the particles of the obtained film is easily improved.

In one embodiment of the present invention, the HSP value distance between the 1 st solvent and the polyimide-based resin (a) is preferably larger than the radius of interaction of the polyimide-based resin (a). In this relation, the polyimide resin (a) is hardly soluble in the 1 st solvent, so that the formation of aggregates of the particulate polymer (B) is easily suppressed, and the particle diameter is easily reduced, thereby easily improving the dispersibility. In addition, the mechanical properties such as surface smoothness, particle dispersibility, heat resistance, water absorption resistance, and bending resistance of the obtained film are easily improved, and the CTE is easily lowered.

In one embodiment of the present invention, it is preferable that the solubility of the polymer (B) in the 1 st solvent is greater than the solubility of the polymer (B) in the 2 nd solvent. In such a relation, the particulate polymer (B) having a small particle diameter and good dispersibility can be easily obtained. The solubility of the polymer (B) in the solvent can be measured by the following method. To a sample bottle were added 1,000mg of polymer (B) and 3mL of a solvent, and the mixture was stirred at room temperature for 2 hours. Subsequently, the solid phase was separated from the liquid phase by filtration, and the mass after drying the solid phase at 80 ℃ for 2 hours under reduced pressure was measured: x (mg) can be used to determine the solubility Y (mg/mL) by the following formula.

Y＝(1,000-X)/3

For example, in the definition of the present specification, when the polymer (B) is "dissolved" in the 1 st solvent and is "insoluble" in the 2 nd solvent, the solubility in the 1 st solvent is significantly higher, and therefore the solubility may not be measured.

The content of the polymer (B) in the polymer (B) solution is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, further preferably 0.1% by mass or more, further more preferably 0.5% by mass or more, preferably 20% by mass or less, more preferably 10% by mass or less, and further preferably 5% by mass or less. When the content of the polymer (B) in the solution is not less than the above lower limit, the composition can be easily produced. When the content of the polymer (B) in the solution is not more than the above upper limit, a dispersion and a film having a small particle diameter and high dispersibility can be easily obtained.

The method for dissolving the polymer (B) in the 1 st solvent is not particularly limited, and for example, the 1 st solvent may be added to the polymer (B), the polymer (B) may be added to the 1 st solvent, or both of them may be added. Depending on the solubility of the 1 st solvent in the polymer (B), the polymer (B) may be dissolved by heating or the like.

The step (2) is a step of: after the polymer (B) solution was brought into contact with the 2 nd solvent, the 1 st solvent was distilled off to obtain a particulate polymer (B) dispersion.

The 2 nd solvent is not particularly limited as long as it is a solvent capable of forming the particulate polymer (B) by contact with the polymer (B) solution, and examples thereof include amide solvents such as DMAc and DMF; lactone solvents such as GBL and gamma valerolactone; sulfur-containing solvents such as dimethyl sulfone, dimethyl sulfoxide and sulfolane; carbonate solvents such as ethylene carbonate and propylene carbonate; pyrrolidone-based solvents such as N-methylpyrrolidone; and combinations thereof. Among them, from the viewpoint of easily suppressing aggregation of the particulate polymer (B) and having high particle dispersibility, and as a result, easily obtaining a film having low brightness, high water absorption resistance, a smooth surface, a low CTE, high heat resistance, and high mechanical properties, at least 1 selected from the group consisting of amide-based solvents, lactone-based solvents, and pyrrolidone-based solvents is preferable. These solvents may be used alone or in combination of two or more. The dispersion of the particulate polymer (B) may contain water, an alcohol-based solvent, a ketone-based solvent, an acyclic ester-based solvent, an ether-based solvent, and the like.

In one embodiment of the present invention, the distance between the HSP values of the 2 nd solvent and the polymer (B) is preferably 8.5 or more, more preferably 9.0 or more, further preferably 10.0 or more, and further more preferably 11.0 or more. When the distance between HSP values is equal to or more than the lower limit, aggregation of the particles of the polymer (B) is easily suppressed, and the particle diameter is easily reduced, so that the dispersibility of the particles is easily improved. As a result, the brightness of the obtained film can be easily lowered, and the mechanical properties such as water absorption resistance, particle dispersibility, surface smoothness, heat resistance, and bending resistance can be easily improved. The upper limit of the distance between the HSP number of the 2 nd solvent and the polymer (B) is preferably 30.0 or less, more preferably 25.0 or less, and still more preferably 20.0 or less. When the HSP value of the solvent 2 and the polymer (B) is equal to or less than the upper limit, aggregation of the particulate polymer (B) is easily suppressed, and therefore, dispersibility of the particles is easily improved.

In one embodiment of the present invention, it is preferable that the distance between the HSP number of the 2 nd solvent and the polymer (B) is larger than the interaction radius of the polymer (B). In such a relation, since the polymer (B) is hardly soluble in the 2 nd solvent, the particle diameter of the particulate polymer (B) in the particulate polymer (B) dispersion liquid is easily reduced, and the dispersibility is easily improved.

In one embodiment of the present invention, the 2 nd solvent is preferably a solvent in which the polymer (B) is insoluble. Such a solvent can easily suppress aggregation of the particulate polymer (B), and thus can easily reduce the particle diameter and can easily improve the dispersibility of the particles.

In one embodiment of the present invention, the 2 nd solvent is preferably a solvent in which the polyimide-based resin (a) is soluble. In the case of such a solvent, the particulate polymer (B) is easily dispersed in the obtained composition or film in a small particle size. In addition, the membrane easily forms a sea-island structure.

In one embodiment of the present invention, the HSP value distance between the 2 nd solvent and the polyimide-based resin (a) is preferably 10.0 or less, more preferably 9.5 or less, still more preferably 9.0 or less, particularly preferably 8.5 or less, preferably 0.01 or more, more preferably 0.1 or more. When the distance between HSP values is not more than the above upper limit, the affinity between the 2 nd solvent and the polyimide resin (a) can be improved, and therefore, the particulate polymer (B) is easily dispersed in the obtained composition or film with a small particle size, and the particle dispersibility is improved.

In one embodiment of the present invention, the distance between the HSP value of the 2 nd solvent and the polyimide-based resin (a) is preferably smaller than the interaction radius of the polyimide-based resin (a). In this connection, the polyimide resin (a) is easily dissolved in the 2 nd solvent, and therefore, the particulate polymer (B) is easily dispersed in the obtained composition with a small particle size, and the particle dispersibility is easily improved.

The method of contacting the polymer (B) solution with the 2 nd solvent is not particularly limited, and for example, a method of mixing the polymer (B) solution with the 2 nd solvent may be mentioned. Specifically, a method of adding the polymer (B) solution to the 2 nd solvent, and a method of adding the 2 nd solvent to the polymer (B) solution can be exemplified. By bringing the first and second solvents into contact with each other in this manner, the particulate polymer (B) having a small particle diameter can be precipitated or dispersed in the mixed solution of the 2 nd solvent and the 1 st solvent. In the step (2), a small amount of the polyimide-based resin (a) and other additives may be added at any timing as long as aggregation of the particulate polymer (B) does not occur.

The amount of the polymer (B) solution to be contacted with the 2 nd solvent is preferably 0.01 part by mass or more, more preferably 0.1 part by mass or more, further preferably 0.3 part by mass or more, particularly preferably 0.7 part by mass or more, preferably 100 parts by mass or less, more preferably 10 parts by mass or less, further preferably 3 parts by mass or less, and particularly preferably 1.5 parts by mass or less, relative to 1 part by mass of the 2 nd solvent. When the amount of the polymer (B) solution to be contacted with the 2 nd solvent is in the above range, aggregation of the particulate polymer (B) is easily suppressed, and therefore, the particle diameter is easily decreased and the dispersibility of the particles is easily improved.

In the step (2), the polymer (B) solution is brought into contact with the 2 nd solvent, and then the 1 st solvent is distilled off. The dispersion stability of the particulate polymer (B) can be improved by the distillation removal of the first solvent 1. Further, the polymer (B) may be further precipitated by the distillation removal of the 1 st solvent. The 1 st solvent may be at least partially distilled off or removed, and the 1 st solvent may remain in the dispersion liquid containing the particulate polymer (B). From the viewpoint of easily suppressing aggregation of the polymer (B) and easily preparing the dispersion, it is preferable that a part of the 1 st solvent remains or is contained in the particulate polymer (B) dispersion.

In the step (2), the method for distilling off the 1 st solvent is not particularly limited, and a method of distilling off the solvent under reduced pressure using an evaporator or the like can be exemplified. The pressure and temperature at the time of the distillation removal can be appropriately selected depending on the characteristics such as boiling points of the 1 st solvent and the 2 nd solvent. In the present production method, in order to distill and remove the 1 st solvent from the mixed solution of the 1 st solvent and the 2 nd solvent, the boiling point of the 1 st solvent is usually lower than the boiling point of the 2 nd solvent.

The content of the 1 st solvent contained in the particulate polymer (B) dispersion obtained after the 1 st solvent is distilled off is preferably 120 parts by mass or less, more preferably 100 parts by mass or less, further preferably 60 parts by mass or less, further more preferably 45 parts by mass or less, particularly preferably 40 parts by mass or less, particularly preferably 35 parts by mass or less, particularly preferably 30 parts by mass or less, particularly more preferably less than 30 parts by mass, most preferably 25 parts by mass or less, preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and further preferably 0.1 parts by mass or more, relative to 100 parts by mass of the content of the 2 nd solvent. When the content of the 1 st solvent is not more than the above upper limit, aggregation of the particulate polymer (B) is easily suppressed, and therefore, the particle diameter is easily reduced and the dispersibility of the particles is easily improved. As a result, the brightness of the obtained film is easily reduced, and the water absorption resistance, particle dispersibility, surface smoothness, and mechanical properties are easily improved. When the content of the 1 st solvent is not less than the lower limit, the dispersion can be easily prepared. The content of the 1 st solvent in the particulate polymer (B) dispersion can be measured by gas chromatography, and can be calculated, for example, by the method described in examples.

In one embodiment of the present invention, the content of the solvent contained in the particulate polymer (B) dispersion is preferably 50% by mass or more, more preferably 70% by mass or more, further preferably 90% by mass or more, particularly preferably 95% by mass or more, preferably 99.99% by mass or less, more preferably 99.9% by mass or less, further preferably 99% by mass or less, and particularly preferably 95% by mass or less, based on the mass of the dispersion. When the content of the solvent is in the above range, aggregation of the particulate polymer (B) is easily suppressed, so that the particle diameter is easily reduced and the dispersibility of the particles is easily improved. As a result, the water absorption resistance, particle dispersibility, surface smoothness, mechanical properties, and the like of the obtained film are easily improved.

In one embodiment of the present invention, the solvent contained in the particulate polymer (B) dispersion may contain other solvents than the 1 st solvent and the 2 nd solvent within a range not to impair the effects of the present invention. The other solvent is not particularly limited, and a conventional solvent can be used. In one embodiment of the present invention, the total mass of the 1 st solvent and the 2 nd solvent is preferably 50% by mass or more, more preferably 70% by mass or more, further preferably 90% by mass or more, further more preferably 95% by mass or more, and preferably 100% by mass or less, relative to the mass of the solvent contained in the dispersion. When the total mass of the 1 st solvent and the 2 nd solvent is in the above range, aggregation of the particulate polymer (B) is easily suppressed, and therefore, the particle diameter is easily reduced and the dispersibility of the particles is easily improved. As a result, the water absorption resistance, particle dispersibility, surface smoothness, mechanical properties, and the like of the obtained film are easily improved.

The content of the particulate polymer (B) contained in the particulate polymer (B) dispersion obtained after the distillation removal of the 1 st solvent is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, further preferably 1% by mass or more, preferably 50% by mass or less, more preferably 30% by mass or less, further preferably 10% by mass or less, and particularly preferably 5% by mass or less, based on the mass of the particulate polymer (B) dispersion. When the content of the polymer (B) is in the above range, the dispersibility of the particles is easily improved, so that the brightness of the film is easily reduced, and the water absorption resistance, the particle dispersibility, the surface smoothness, and the mechanical properties are easily improved.

The dispersion of the particulate polymer (B) preferably contains the particulate polymer (B) having a median particle diameter of 0.01 to 15 μm. The median particle diameter of the particulate polymer (B) is preferably 0.01 μm or more, more preferably 0.03 μm or more, further preferably 0.05 μm or more, preferably 15 μm or less, more preferably 10 μm or less, further preferably 5 μm or less, further preferably 3 μm or less, particularly preferably 1 μm or less, particularly preferably 0.8 μm or less, and particularly preferably 0.5 μm or less. When the median particle diameter of the particulate polymer (B) in the dispersion is not less than the above-described lower limit, the dielectric characteristics of a film formed from the composition can be easily improved, and the film can be easily produced. When the median particle diameter of the particulate polymer (B) in the dispersion is not more than the upper limit, the brightness of a film formed from the composition is easily reduced, and the mechanical properties such as particle dispersibility, water absorption resistance, surface smoothness, and bending resistance are easily improved. The median particle diameter of the particulate polymer (B) in the dispersion can be determined by scattering particle size distribution measurement using laser diffraction. For example, as described in examples, the particle-shaped polymer (B) dispersion can be obtained by preparing a dispersion sample by diluting the dispersion with a solvent and measuring the obtained dispersion sample with a laser diffraction/scattering particle size distribution measuring apparatus (manufactured by Malvern Panalytical Co., ltd., model: nanoZS, refractive index: 1.70 to 0.20 i). In the present specification, the median diameter is also referred to as D50, and indicates a value at which the number of particles of the particulate polymer (B) on the side having a smaller size than the median diameter is equal to the number of particles on the side having a larger size than the median diameter.

The step (3) is a step of adding the polyimide resin (a) to the dispersion of the particulate polymer (B). The polyimide resin (a) to be added in the step (3) may be in the form of a solid, preferably a powder, or may be in the form of a varnish prepared by dissolving the polyimide resin (a) in a predetermined solvent, for example, the 2 nd solvent. In one embodiment of the present invention, in the step (3), a polyimide resin or a polyamic acid may be added in the form of a solid, preferably a powder, or in the form of a varnish. When the polyimide resin (a) is added in the form of a varnish, the content of the polyimide resin (a) in the varnish is preferably 0.1% by mass or more, more preferably 1% by mass or more, further preferably 5% by mass or more, further preferably 10% by mass or more, preferably 50% by mass or less, more preferably 30% by mass or less, and further preferably 20% by mass or less, based on the mass of the varnish. When the content of the polyimide-based resin (a) in the varnish is in the above range, the film formation is facilitated, and therefore, it is advantageous from the viewpoint of film production.

The polyimide resin (a) added in the step (3) is preferably 50% by mass or more, more preferably 60% by mass or more, further preferably 65% by mass or more, preferably 95% by mass or less, more preferably 93% by mass or less, and further preferably 90% by mass or less, based on the total mass of the polymer (B) and the polyimide resin (a) in the particulate polymer (B) dispersion. When the content of the polyimide-based resin (a) added in the step (3) is not less than the above-described lower limit, the film formation is facilitated, and therefore, it is advantageous from the viewpoint of film production. When the content of the polyimide-based resin (a) added in the step (3) is not more than the above-described upper limit, the dispersibility of the particulate polymer (B) in the dispersion and the composition is likely to be improved, and therefore, variations in physical properties such as brightness, thermal conductivity, and thermal diffusivity of the obtained film are likely to be reduced, and water absorption resistance, particle dispersibility, surface smoothness, mechanical properties, and the like are likely to be improved.

The method of adding the polyimide resin (a) to the dispersion of the particulate polymer (B) is not particularly limited, and the polyimide resin (a) may be added all at once or may be added in plural portions.

The step of preparing the composition according to one embodiment of the present invention may include steps other than the steps (1) to (3) within a range not impairing the effects of the present invention, and a polymer or an additive other than the polyimide resin (a) and the polymer (B), for example, the additives exemplified above, may be used.

In the preferred embodiment of the present invention, the polyimide resin (a) is added to the dispersion of the particulate polymer (B), but the polymer (B) in powder form may be added to the varnish of the polyimide resin (a). As shown in the step (3), the varnish of the polyimide resin (a) may be a varnish obtained by dissolving the polyimide resin (a) in a predetermined solvent, for example, the 2 nd solvent, or may be a resin solution obtained when a precursor of the polyimide resin (a) is synthesized, for example, a polyamic acid solution (a solution containing at least a polyamic acid and a synthesis solvent).

The content of the particulate polymer (B) contained in the composition obtained in the composition preparation step is usually 1 mass% or more, preferably 5 mass% or more, more preferably 10 mass% or more, further preferably 15 mass% or more, particularly preferably 20 mass% or more, preferably 50 mass% or less, more preferably 40 mass% or less, further preferably 35 mass% or less, and particularly preferably 30 mass% or less, with respect to the total mass of the polyimide resin (a) and the particulate polymer (B). When the content of the particulate polymer (B) in the composition is not less than the above-described lower limit, the dispersibility of the particulate polymer (B) is easily improved, and therefore, the brightness of the obtained film is easily reduced, and the water absorption resistance, the particle dispersibility, the surface smoothness, and the mechanical properties are easily improved. When the content of the particulate polymer (B) in the composition is not more than the above upper limit, the brightness of the film is easily reduced, and the film is easily formed, which is advantageous from the viewpoint of film production. Since the uniformity of thermal conductivity, thermal diffusivity, and CTE is high when the dispersibility of particles in the film is high, for example, when the film is used as a resin layer of CCL, the peeling between the film and the copper foil is easily suppressed.

In the preferred embodiment of the present invention, the polyimide resin (a) is added to the dispersion of the particulate polymer (B), but the polymer (B) in powder form may be added to the varnish of the polyimide resin (a).

In one embodiment of the present invention, the total mass of the polyimide resin (a) and the particulate polymer (B) contained in the composition is preferably 1 mass% or more, more preferably 3 mass% or more, further preferably 5 mass% or more, preferably 50 mass% or less, more preferably 40 mass% or less, further preferably 30 mass% or less, further more preferably 20 mass% or less, and particularly preferably 10 mass% or less. When the total mass of the polyimide resin (a) and the particulate polymer (B) contained in the composition is in the above range, the water absorption resistance, the dielectric properties, and the surface smoothness of the film can be easily improved.

The content of the 1 st solvent contained in the composition obtained in the composition preparation step is preferably 100 parts by mass or less, more preferably 60 parts by mass or less, further preferably 45 parts by mass or less, further more preferably 30 parts by mass or less, particularly preferably less than 30 parts by mass, particularly preferably 25 parts by mass or less, preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and further preferably 0.1 parts by mass or more, relative to 100 parts by mass of the content of the 2 nd solvent. When the content of the 1 st solvent is not more than the above upper limit, aggregation of the particulate polymer (B) is easily suppressed, and the particle diameter is easily reduced, whereby the dispersibility is easily improved. Therefore, a film having low lightness, high water absorption resistance, surface smoothness, and high mechanical properties can be easily obtained. When the content of the 1 st solvent is not more than the upper limit, the uniformity of the thermal conductivity or thermal diffusivity, the surface smoothness, and the mechanical properties of the film are easily improved. When the content of the 1 st solvent is not less than the above lower limit, the composition can be easily produced.

The content of the solvent contained in the composition obtained in the composition preparation step is preferably 50% by mass or more, more preferably 60% by mass or more, further preferably 70% by mass or more, further more preferably 80% by mass or more, particularly preferably 90% by mass or more, preferably 99% by mass or less, more preferably 97% by mass or less, and further preferably 95% by mass or less, based on the mass of the composition. When the content of the solvent is within the above range, aggregation of the particulate polymer (B) is easily suppressed, and the particle diameter is easily reduced, whereby the dispersibility is easily improved. Therefore, a film having high water absorption resistance, surface smoothness and high mechanical properties can be easily obtained. When the content of the solvent is not less than the lower limit, the obtained composition is easily kneaded, and thus moldability of the film is easily improved, and when the content is not more than the upper limit, the sedimentation and floating of the particulate polymer (B) in the obtained composition are easily suppressed, and thus the dispersibility of the particulate polymer (B) is easily improved.

The solvent contained in the composition obtained in the composition preparation step may contain other solvents than the 1 st solvent and the 2 nd solvent within a range not impairing the effects of the present invention. The other solvent is not particularly limited, and a common solvent can be used. In one embodiment of the present invention, the total mass of the 1 st solvent and the 2 nd solvent is preferably 50% by mass or more, more preferably 70% by mass or more, further preferably 90% by mass or more, further more preferably 95% by mass or more, and preferably 100% by mass or less, relative to the mass of the solvent contained in the composition. When the total mass of the 1 st solvent and the 2 nd solvent is within the above range, aggregation of the particulate polymer (B) is easily suppressed, and the particle diameter is easily reduced, whereby the dispersibility is easily improved. Therefore, a film having high water absorption resistance, surface smoothness and high mechanical properties can be easily obtained.

The median particle diameter of the particulate polymer (B) in the composition obtained in the composition preparation step may be selected from the same range as the median particle diameter of the particulate polymer (B) in the dispersion. The method for determining the median particle diameter of the particulate polymer (B) in the composition is not particularly limited, and can be determined, for example, by a centrifugal sedimentation type particle size distribution measuring apparatus or an ultrasonic attenuation type particle size distribution measuring apparatus. In the step (3), when the composition is formed by adding the polyimide resin (a) to the dispersion of the particulate polymer (B) in an amount within a range not affecting the particle diameter of the particulate polymer (B), the particle diameter in the dispersion may be measured and used as the particle diameter in the composition.

The composition obtained in the composition preparation step may contain the additives exemplified above as necessary. In one embodiment of the present invention, since the composition of the present invention is produced by the above-described method of the present invention, the particle diameter of the particulate polymer (B) is small and the dispersibility is excellent even if the composition does not contain a compatibilizer. Therefore, in the composition of the present invention, the content of the compatibilizer is preferably 5 parts by mass or less, more preferably 1 part by mass or less, further preferably 0.1 part by mass or less, further more preferably less than 0.1 part by mass, particularly preferably 0.05 part by mass or less, particularly preferably 0.01 part by mass or less, particularly preferably 0.001 part by mass or less, and most preferably 0 part by mass, based on 100 parts by mass of the polyimide resin (a). In addition, when the polyimide resin (a) is a polyimide resin precursor such as polyamic acid and thermal imidization is required in producing a film, the content of the compatibilizing agent is preferably less than 0.1 part by mass in the above range from the viewpoint of preventing inhibition of imidization by the compatibilizing agent and deterioration of film properties due to deterioration of the compatibilizing agent by heating. The content of the compatibilizer may be a content based on 100 parts by mass of the total of the polyimide resin (a) and the polymer (B) in place of 100 parts by mass of the polyimide resin (a).

(coating step and film-Forming step)

The coating step is a step of applying the composition obtained in the steps (1) to (3) to a substrate to form a coating film.

In the coating step, the composition is applied to the substrate by a known coating method to form a coating film. Known coating methods include, for example, a roll coating method such as a wire bar coating method, a reverse coating method, and a gravure coating method, a die coating method, a comma coating method, a lip coating method, a spin coating method, a screen printing coating method, a jet blade coating method, a dipping method, a spraying method, a curtain coating method, a slit coating method, and a casting method.

Examples of the base material include a copper plate (including copper foil), a SUS plate (including SUS foil and SUS ribbon), a glass substrate, a PET film, a PEN film, another polyimide resin film, and a polyamide resin film. Among them, from the viewpoint of excellent heat resistance, preferred examples include a copper plate, an SUS plate, a glass substrate, a PET film, a PEN film, and the like, and more preferred examples include a copper plate, an SUS plate, a glass substrate, a PET film, and the like from the viewpoint of adhesion to a film and cost.

In the film forming step, the coating film may be dried and peeled from the substrate to form a film. In one embodiment of the present invention, when the substrate is a copper foil, a film may be formed without peeling the coating film from the copper foil, and a laminate obtained by laminating the film on the obtained copper foil may be used for the copper-clad laminate. In the case of peeling, a drying step of drying the film may be further performed after the peeling. The drying of the coating film may be appropriately selected depending on the heat resistance of the polyimide resin (a) and the like, and may be performed at a temperature of 50 to 450 ℃, preferably 70 to 400 ℃ in one embodiment of the present invention, or at a temperature of 50 to 350 ℃, preferably 70 to 300 ℃ in another embodiment of the present invention. In a preferred embodiment of the present invention, drying is preferably performed in stages. By stepwise drying, the composition can be uniformly dried, and the brightness of the obtained film is easily reduced, so that the water absorption resistance is easily improved, and in addition, the decrease in CTE due to the increase in Tg of the obtained film, and the improvement in mechanical properties and surface smoothness are easily achieved. For example, the heating may be performed at a temperature of 200 to 450 ℃ and preferably 200 to 350 ℃ after heating at a relatively low temperature of 50 to 150 ℃. The drying or heating time is preferably 5 minutes to 10 hours, more preferably 10 minutes to 5 hours. By heating from low temperature to high temperature in stages in such a range, the water absorption resistance, the uniformity of thermal conductivity or thermal diffusivity, the optical properties, and Tg of the obtained film can be easily improved. If necessary, the coating film may be dried under inert atmosphere conditions such as nitrogen and argon, under vacuum or reduced pressure, and/or under ventilation.

In the case of stepwise drying, the coating film may be continuously dried after the coating film is peeled from the substrate between stepwise drying, or the coating film (film) may be peeled from the substrate after all drying is completed. For example, the coating film may be peeled from the substrate after the 1 st stage of drying and then dried after the 2 nd stage, or the coating film (film) may be peeled from the substrate after all the drying stages have been completed. It should be noted that the drying in stage 1 may be pre-drying.

When the substrate is a copper foil, the film can be peeled from the copper foil as the substrate by etching and removing the copper foil with an iron chloride solution or the like, for example.

In one embodiment of the present invention, when the polyimide resin (a) in the composition is a polyimide resin precursor, for example, polyamic acid, and a polyimide resin is produced in the production of a film, it is preferable to perform thermal imidization by heating after applying the composition to a substrate. By this heating, the drying for removing the solvent and the thermal imidization can be simultaneously performed. The drying and imidization temperature is usually in the range of 50 to 450 ℃, and it is preferable to heat the resin in stages from the viewpoint of easily obtaining a smooth film having excellent water absorption resistance. For example, the solvent may be removed by heating at a relatively low temperature of 50 to 150 ℃ and then heating the mixture in stages to a temperature in the range of 300 to 450 ℃. The heating time may be selected from the same range as the above range, for example.

When the film of the present invention is a multilayer film, it can be produced by a multilayer film forming method such as a coextrusion method, an extrusion lamination method, a thermal lamination method, or a dry lamination method.

[ composition ]

The present invention also includes a composition comprising a polyimide resin (A), a particulate polymer (B), and a solvent, wherein the solvent comprises a 1 st solvent and a 2 nd solvent, and the distance between the HSP value of the 2 nd solvent and the HSP value of the particulate polymer (B) is 8.5 or more. In a preferred embodiment of the present invention, the composition of the present invention is preferably the composition described in the above [ method for producing a film ], and the polyimide-based resin (a), the particulate polymer (B) and the solvent contained in the composition are the same as those described in the above [ film ] and [ method for producing a film ].

The composition of the present invention comprises a polyimide resin (A), a particulate polymer (B) and a solvent, wherein the solvent comprises a 1 st solvent and a 2 nd solvent, and the HSP value distance between the 2 nd solvent and the particulate polymer (B) is 8.5 or more, so that the lightness is reduced, and as a result, a film having improved water absorption resistance can be formed. The composition of the present invention can form a film having a reduced CTE as compared with conventional composite films. In addition, the composition of the present invention can form a film that exhibits excellent mechanical properties such as bending resistance even if the Tg of the polymer (B) is high. Therefore, the composition of the present invention can form a film having excellent mechanical properties such as water absorption resistance, surface smoothness, heat resistance and bending resistance and a reduced CTE.

Examples

The present invention will be described more specifically below with reference to examples and comparative examples, but the present invention is not limited to the following examples. First, the measurement method will be explained.

< brightness >

The composite films obtained in examples and comparative examples were measured for lightness (L) of reflected light on both sides of the film using a spectrophotometer under the following conditions ^* ) Evaluation was carried out.

The device comprises the following steps: CM3700A manufactured by Konica Minolta

Light source: d light source

Incident light: for films, at an angle of 2 ° to the normal direction

Detection mode: reflective SCE

Target mask: LAV cover (measuring range: diameter 8 mm)

Sample determination conditions: the film was set at the position of reflection measurement, and the measurement was performed by shielding the film with a dark box.

< haze >

The composite films obtained in examples and comparative examples were measured under the following conditions using a haze meter according to JIS K7136. The measurement values are the average of the values measured 5 times.

The device comprises the following steps: HM-150 of Kabusura color technology research institute

The number of times of measurement: 5 times of

< Norbornene (NB) content >

The content of norbornene-derived monomer units (also referred to as "NB content") in the cycloolefin copolymer obtained in production example was used ¹³ C-NMR was measured. ¹³ The C-NMR measurement conditions were as follows.

The device comprises the following steps: AVANCE600, 10mm cryoprobe from Bruker

Measuring temperature: 135 deg.C

The determination method comprises the following steps: proton decoupling method

Concentration: 100mg/mL

Cumulative number of times: 1024 times

Pulse width: 45 degree

Pulse repetition time: 4 seconds

Chemical shift value benchmark: tetramethylsilane

Solvent: 1,2-dichlorobenzene-d ₄ And 1,1,2,2-tetrachloroethane-d ₂ Is 85:15, a mixed solvent

The NB content in the cycloolefin copolymer was calculated based on the assignment described in "r.a. wendt, g.fink, macromol. Chem. Phys.,2001,202,3490" based on 1,2-dichlorobenzene (127.68 pp m). In particular, according to the use ¹³ Integral value of signal observed at chemical shift value of 44.0-52.0ppm of spectrum measured by C-NMR: I.C. A _C2,C3 (carbon atoms at positions 2 and 3 of norbornene ring), and an integrated value of a signal observed at a chemical shift value of 27.0 to 33.0 ppm: i is _C5,C6 +I _CE (carbon atoms at positions 5 and 6 and carbon atom at the ethylene part from the norbornene ring) can be obtained by the following formula.

NB content (mol%) = I _C2,C3 /(I _C5,C6 +I _CE )×100

< Hansen Solubility Parameter (HSP) and distance between HSP values >

The Hansen Solubility Parameters (HSP) and the distance between HSP values of the cycloolefin copolymer, the polyimide resin, the solvent and the fluoropolymer obtained in the production examples were determined as follows.

(Hansen solubility parameter of solvent (HSP))

HSP value of solvent Using the value of HSPiP (Ver.4.1.07) database, δ D of GBL was set to 18.0MPa ^0.5 Delta P is 16.6MPa ^0.5 Delta H is 7.4MPa ^0.5 Setting the delta D of DMAc to 16.8MPa ^0.5 Delta P is 11.5MPa ^0.5 Delta H is 9.4MPa ^0.5 Setting delta D of toluene to 18.0MPa ^0.5 Delta P is 1.4MPa ^0.5 Delta H is 2.0MPa ^0.5 。

(HSP of cycloolefin copolymer)

The solubility of the cycloolefin copolymers in various solvents was evaluated. In the evaluation of solubility, a transparent container was charged with 10mL of a solvent (solvent used in reference to the HSPiP database: methyl chloride, 1,4-dichlorobenzene, chloroform, toluene, p-xylene, GBL, DMAc, NMP, water, acetone, diiodomethane, butyl benzoate) having known solubility parameters and 0.1g of a cycloolefin copolymer to prepare a mixed solution. The obtained mixed solution was subjected to ultrasonic treatment for 6 hours in total. The appearance of the mixed solution after the ultrasonic treatment was visually observed, and from the obtained observation results, the solubility of the resin in each solvent was evaluated based on the following evaluation criteria.

(evaluation criteria)

2: the appearance of the mixture was cloudy at room temperature and precipitates were formed, but the appearance of the mixture was transparent by heating to 50 ℃ and stirring with a stirrer for 30 minutes.

1: the appearance of the mixture was clear at room temperature.

0: the appearance of the mixture was cloudy at room temperature, a precipitate was formed, and the appearance of the mixture was not transparent even when the mixture was heated to 50 ℃ and stirred with a stirrer for 30 minutes.

From the results of the evaluation of the solubility of the obtained cycloolefin copolymer in the solvent, HSPiP was used to calculate an HSP value by the Hansen globule method described above.

(HSP of polyimide resin)

The solubility of the polyimide resin in various solvents was evaluated. In the evaluation of solubility, a transparent container was charged with 10mL of a solvent having known solubility parameters (see database of HSPiP, solvent used: acetone, toluene, ethanol, tetrahydrofuran, N-dimethylformamide, dimethyl sulfoxide, hexane, GBL, ethyl acetate, methyl ethyl ketone, propylene glycol monomethyl ether, 1-butanol, N-methylformamide, 1-methylnaphthalene, bromobenzene, 1-methylimidazole, pyrazole, acetic acid) and 0.1g of a polyimide-based resin to prepare a mixed solution. The obtained mixed solution was subjected to ultrasonic treatment for 6 hours in total. The appearance of the liquid mixture after the ultrasonic treatment was visually observed, and from the obtained observation results, the solubility of the resin in each solvent was evaluated based on the following evaluation criteria.

(evaluation criteria)

1: the appearance of the mixture was cloudy.

0: the appearance of the mixed solution is transparent.

Based on the evaluation result of the solubility of the obtained polyimide resin in a solvent, the HSP value was calculated by the hansen photosphere method using HSPiP.

(HSP of fluoropolymer (PTFE))

The HSP value of PTFE is measured by The literature (Marion K. Buckley-Smith, "The Use of Solubility Parameters to Select Membrane Materials for Perposition of Organic Mixtures", huai Katuo University (The University of Waikato), hamilton, new Zealand, 2006, P52). Delta D is 17.1MPa ^0.5 Delta P is 8.1MPa ^0.5 Delta h is 1.3MPa ^0.5 。

(HSP inter-value distance)

The distance between HSP values (Ra) of 2 substances was determined by the following formula (Y).

< meso type double-linked chain/racemic type double-linked chain >

The ratio of meso type double-link chain to racemic type double-link chain (meso type double-link chain/racemic type double-link chain) of norbornene double-link chain of the cycloolefin copolymer obtained in production example was used ¹³ C-NMR was measured under the same conditions as those for the measurement of NB content.

The meso type double strand/racemic type double strand of the norbornene double strand was calculated based on the assignments described in "r.a. wendt, g.fink, macromol.chem.phys.,2001,202,3490" and "jp 2008-285656 a" based on 1,1,2,2-tetrachloroethane (74.24 ppm). Specifically, as for meso type double-linked chain/racemic type double-linked chain, depending on the use ¹³ Integral value of signal observed at chemical shift value of 27.5-28.4ppm of spectrum measured by C-NMR: i is _C5,C6 -m (norbornene from meso type double-linked chain)Carbon atoms at positions 5 and 6 of the ring), an integral value of the signal observed at a chemical shift value of 28.4 to 29.6 ppm: i is _C5,C6 R (carbon atoms at positions 5 and 6 of the norbornene ring derived from the racemic type double bond) is determined by the following formula.

Meso form double-link/racemic form double-link = I _C5,C6 -m/I _C5,C6 -r

< refractive index >

The refractive index of the cycloolefin copolymer obtained in production example was determined as follows: the sheet-like specimen obtained by molding the sheet-like specimen with a thickness of 100 μm by a vacuum press was used, and the measurement was performed under the following conditions.

Equipment: abbe refractometer TYPE-3 manufactured by Atago

Wavelength of light source: 589.3nm

Intermediate liquid: 1-bromonaphthalene

Measuring temperature: 23 + -1 deg.C

< glass transition temperature >

(cycloolefin copolymer)

The Tg of the cycloolefin copolymer obtained in the production example was determined as follows: the softening temperature was measured by TMA in accordance with JIS K7196. Specifically, a sample (thickness: 1.0 mm) obtained by molding a cycloolefin copolymer into a sheet shape by a vacuum press was measured under the following conditions, and the softening temperature was set to the starting temperature (onset) of the displacement when the indenter was sunk into the sample.

The device comprises the following steps: manufactured by Hitachi High-Tech Science Corporation, TMA/SS6200

Diameter of a pressure head: 1mm

Loading: 780mN

Temperature program: the temperature is raised from 20 ℃ to 380 ℃ at the speed of 5 ℃/min

(polyimide resin)

The Tg of the polyimide resin obtained in the production example was determined by the following measurement. Using DMA Q800 manufactured by TA Instrument, measurement was performed under the following test samples and conditions, a tan δ curve which is a ratio of values of loss elastic modulus and storage elastic modulus was obtained, and then Tg was calculated from the uppermost point of the peak of the tan δ curve.

Sample preparation: the length is 5-15mm, and the width is 5mm

Experimental mode: DMA multifrequency Strain (Multi-Frequency-Strain)

Detailed conditions of experimental modes:

(1) Clamp (Clamp): stretching (Tension): film (Film)

(2) Amplitude (Amplitude): 5 μm

(3) Frequency (Frequncy): 10Hz (No variation over the entire temperature range)

(4) Pretension (Preload Force): 0.01N

(5) Force Track (Force Track): 125N

Temperature conditions: (1) temperature rise range: normal temperature to 400 ℃, and (2) heating rate: 5 ℃ per minute

The main data collected: (1) Storage modulus of elasticity (E '), (2) Loss modulus of elasticity (Loss modulus, E "), (3) tan delta (E"/E')

< Mw and Mn of cycloolefin copolymer >

The Mw and Mn in terms of polystyrene of the cycloolefin copolymer obtained in the production example were measured by GPC. GPC measurement was carried out under the following conditions, and a base line on the chromatogram was defined and a peak was designated based on the description of ISO 16014-1.

(GPC apparatus and software)

The device comprises the following steps: HLC-8121GPC/HT (manufactured by Tosoh corporation)

Measurement software: GPC-8020 model II data Collection version 4.32 (manufactured by Tosoh corporation)

Analysis software: GPC-8020 modelII data analysis 4.32 edition (manufactured by Tosoh corporation)

(measurement conditions)

GPC column: to which 3 TSKgel GMH6-HT 7.8mm I.D.. Times.300 mm (manufactured by Tosoh corporation)

Mobile phase: 2,6-di-tert-butyl-4-methylphenol (hereinafter, sometimes referred to as BHT) was added to o-dichlorobenzene (Special grade, manufactured by FUJIFILM Wako Pure Chemical Corporation) at a concentration of 0.1w/V, that is, 0.1g/100mL, and used.

Flow rate: 1 mL/min

Temperature of the column oven: 140 deg.C

Auto-sampler temperature: 140 deg.C

Temperature of the system oven: 40 deg.C

And (3) detection: differential Refractive Index Detector (RID)

RID cell temperature: 140 deg.C

Injection amount of sample solution: 300 μ L

Calibration standard for GPC column: the polystyrene was prepared by weighing standard polystyrene prepared by Tosoh corporation in such a combination as shown in table 1 below, adding 5mL of o-dichlorobenzene having the same composition as that of the mobile phase to each combination, and dissolving the mixture at room temperature for 2 hours. After the calibration of the column was performed using the obtained standard substance for GPC column calibration, the measurement of the sample was performed as follows.

[ Table 1]

Combination 1	F700 0.4mg	F20 0.9mg	A5000 1.2mg
				Combination 2	F288 0.4mg	F10 1.0mg	A2500 1.2mg
Combination 3	F80 0.7mg	F4 1.1mg	A1000 1.3mg
				Combination 4	F40 0.8mg	F2 1.1mg	A500 1.3mg

(conditions for preparation of sample solution)

Solvent: BHT was added to o-dichlorobenzene (Special grade, manufactured by FUJIFILM Wako Pure Chemical Corporation) at a concentration of 0.1w/V, that is, 0.1g/100mL, and used.

Concentration of sample solution: 1mg/mL

Automatic oscillator for dissolution: DF-8020 (manufactured by Tosoh corporation)

Dissolution conditions: 5mg of the sample was sealed in a SUS-made metal mesh bag of 1,000 mesh, the metal mesh bag in which the sample was sealed was put in a test tube, 5mL of o-dichlorobenzene having the same composition as the mobile phase was further added, the test tube was covered with an aluminum foil, the test tube was set on DF-8020, and the mixture was stirred at 140 ℃ for 120 minutes at a stirring speed of 60 cycles/minute. The stirred solution was used as a sample for GPC measurement.

< Mw of polyimide resin >

The Mw of the polyimide resin obtained in the production example was measured in terms of polystyrene by GPC. The GPC measurement was performed under the following conditions.

GPC measurement

(1) Pretreatment method

A DMF eluent (a DMF solution containing 10mmol/L lithium bromide) was added to the sample so that the concentration became 2mg/mL, and the mixture was heated and cooled while stirring at 80 ℃ for 30 minutes, and then the solution was filtered through a 0.45 μm membrane filter to obtain a measurement solution.

(2) Measurement conditions

Column: TSKgel SuperAWM-H x 2+ SuperAW2500 x 1 (6.0 mm ID, 150mm length, 3 connections)

Eluent: DMF (with addition of 10mmol/L lithium bromide)

Flow rate: 1.0 mL/min

A detector: RI detector

Column temperature: 40 deg.C

Injection amount: 100 μ L

Molecular weight standards: standard polystyrene

< evaluation of solubility >

Whether or not the cycloolefin copolymer, PTFE, and polyimide resin were dissolved in the solvents used in the examples and comparative examples was evaluated as follows.

First, a glass screw tube having a volume of solvent of 9.9g to 30mL was measured, and the glass screw tube was further placed in a magnetic stirrer and stirred. 0.1g of a polymer or resin was added thereto, and stirred at 24 ℃ for 24 hours. After stirring for 24 hours, when no solid was visually confirmed and the solution was transparent, it was evaluated as "dissolved". On the other hand, when a solid was visually confirmed or the solution was opaque, the evaluation was "insoluble".

< particle diameters of particulate cycloolefin copolymer in Dispersion and composition, and particle diameters of particulate PTFE in Dispersion and composition >

The median particle diameters of the particulate cycloolefin copolymer in the particulate cycloolefin copolymer dispersions and the particulate PTFE in the particulate PTFE dispersions obtained in the examples and comparative examples were determined by scattering particle size distribution measurement using laser diffraction.

Specifically, the dispersion obtained in example was charged into a glass cell (cell) having a capacity of 3.5mL, and further diluted 1000 times with GBL or DMAc (using the same solvent as the dispersion) to obtain a dispersion sample containing a particulate cycloolefin copolymer or PTFE. The resulting dispersion sample was measured with a laser diffraction/scattering particle size distribution measuring apparatus (manufactured by Malvern Panalytical Co., ltd., model number: nanoZS, refractive index: 1.70 to 0.20 i) to determine the median particle diameter of the particulate cycloolefin copolymer and the particulate PTFE.

In the examples and comparative examples, the polyimide resin was added to the dispersion in an amount within a range not affecting the particle diameters of the particulate cycloolefin copolymer and the particulate PTFE as described above to form the composition, and therefore the median particle diameter of the particulate cycloolefin copolymer and the particulate PTFE in the dispersion was defined as the median particle diameter of the particulate cycloolefin copolymer and the particulate PTFE in the composition.

< thickness of composite film >

The thickness of the composite films obtained in examples and comparative examples was measured at arbitrary 5 points or more using a digital display scale (ID-C112 XBS, manufactured by Mitutoyo Co., ltd.), and the average value of the thickness was defined as the thickness of the composite film.

< content of solvent in particulate cycloolefin copolymer Dispersion and particulate PTFE Dispersion >

The solvent content in the particulate cycloolefin copolymer dispersion and the particulate PTFE dispersion obtained in the examples and comparative examples was measured by gas chromatography. Specifically, the solvent content in the cycloolefin copolymer dispersion and the particle-shaped PTFE dispersion was calculated by single-point calibration through measurement under the following conditions.

The device comprises the following steps: agilent 7890B gas chromatography (manufactured by Agilent Technologies Inc.)

Column: DB-5 (manufactured by Agilent Technologies Inc.)

Carrier gas: helium

Injection port temperature: 200 deg.C

Detector temperature: 250 ℃ C

Internal standard solution: benzyl alcohol

Solvent: chloroform

<CTE>

(CTE of composite film)

The CTE of the composite films obtained in examples and comparative examples was measured by TMA. Specifically, the CTE was calculated under the following conditions by measurement at 50 ℃ to 100 ℃.

The device comprises the following steps: TMA/SS7100 manufactured by Hitachi High-Tech Science Corporation

Indenter (probe) diameter: 3.5mm

Loading: 50.0mN

Temperature program: the temperature is raised from 20 ℃ to 130 ℃ at the speed of 5 ℃/min

Test piece: rectangular parallelepiped of 40mm × 10mm × 50 μm

(CTE of cycloolefin copolymer)

The CTE of the cycloolefin copolymer was measured under the following conditions using TMA, and the CTE of 50 ℃ to 100 ℃ was calculated.

The device comprises the following steps: TMA/SS6200 manufactured by Hitachi High-Tech Science Corporation

Indenter (probe) diameter: 3.5mm load: 38.5mN temperature program: the temperature is raised from 20 ℃ to 130 ℃ at the speed of 5 ℃/min

Test piece: cuboid of 10mm x 1mm

< Water absorption of composite film >

The composite films obtained in examples and comparative examples were cut out in a size of 100mm × 90 mm. The cut composite film was dried at 80 ℃ for 3 hours, and the mass of the composite film was measured as the mass W0 before water vapor exposure.

A cylindrical beaker having a diameter of 75mm was prepared, 150g of water was charged therein, and the beaker was placed on a heating plate set at 120 ℃ to boil the water. The beaker is covered with a metal plate in such a way that steam does not escape during boiling of the water. After the water was sufficiently boiled, the lid of the metal plate was removed, and the composite film was exposed to water vapor by covering the beaker with the film and further covering the beaker with the metal plate so that the surface of the composite film opposite to the surface contacting the glass substrate at the time of film formation of the film was a surface contacting the vapor. After 5 minutes, the composite film was taken out and the mass was measured as the mass W1 after the water vapor exposure. The water absorption (%) of the film was calculated using the following formula.

Water absorption (%) = (W1-W0)/W1X 100

< standard deviation of average thickness of composite film >

The standard deviation of the average thickness of the composite films obtained in examples and comparative examples was calculated as follows.

On the surface of the film fixed to the glass substrate in a close contact manner, a thickness distribution chart (height distribution chart) using the glass substrate as a reference plane in an arbitrary region of a continuous straight line of 1mm was obtained using a palpation type surface texture measuring instrument (Bruker Japan Dektak XTE). This area was divided into ten equal parts to set 10 measurement areas, and then the average thickness (average height) of each of the 10 measurement areas was obtained. Then, the standard deviation of the average thickness of the composite film was calculated from the obtained average thickness data of 10 points in each measurement region.

< details of the reagents >

For the synthesis of cycloolefin copolymer, toluene manufactured by Sumitomo Chemical Co., ltd., styrene manufactured by FUJIFILM Wako Pure Chemical Corporation, 2-norbornene manufactured by Mitsukawa Chemical industry Co., ltd. (hereinafter referred to as "NB"), triisobutylaluminum manufactured by Tosoh Finechem Inc. (hereinafter referred to as "TIBA"), N-dimethylanilinium tetrakis (pentafluorophenyl) borate manufactured by AGC (Co., ltd.) (hereinafter referred to as "AB") were used.

Toluene obtained by dehydration using molecular sieve 13X (manufactured by Union Showa co., ltd.) and activated alumina (manufactured by sumitomo chemical co., ltd., NKHD-24) and then removing dissolved oxygen by blowing nitrogen gas was used.

NB is a solution (hereinafter referred to as NB solution) obtained by dissolving NB in toluene, dehydrating it with molecular sieve 13X (manufactured by Union Showa co., ltd.) and activated alumina (manufactured by sumitomo chemical co., ltd., NKHD-24), and then removing dissolved oxygen by blowing nitrogen gas. The NB concentration in the NB solution was measured by gas chromatography.

As isopropylidene (cyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) titanium dichloride (hereinafter referred to as a complex), isopropylidene (cyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) titanium dichloride synthesized according to the method described in japanese unexamined patent publication No. 9-183809 was used.

[ production of cycloolefin copolymer solution 1]

< production example 1>

1,501mL of NB solution (NB concentration: 3.00 mol/L) was added to the autoclave whose interior was dried under reduced pressure, and the temperature was raised to 60 ℃. While stirring the system, the ethylene partial pressure: after pressurization at 100kPa, 4.0mL (concentration: 1.0 mol/L) of a hexane solution of TIBA, 0.16g of AB and 10.0mL (concentration: 10 mmol/L) of a toluene solution of a complex were added to start the polymerization of ethylene and NB. In the polymerization, theThe temperature in the system was maintained at 60 ℃ and ethylene was continuously supplied to maintain the pressure in the system at the initial value. After 3 hours had elapsed since the start of the polymerization, 5.0mL of water was added to stop the polymerization, and the solution in the autoclave was discharged. To the discharged solution were added 1,500g of toluene and 100g of magnesium sulfate, followed by stirring, then 100mL of water was added and stirred, and the solid was removed by filtration. The obtained liquid was added dropwise to acetone, and the precipitated powder was separated by filtration. The separated powder was further washed with acetone and dried at 120 ℃ for 2 hours under reduced pressure to obtain 210.0g of a cycloolefin copolymer. The cycloolefin copolymer obtained had an NB content of 84.1mol%, a Tg of 293 ℃, an Mw of 521,000, an Mw/Mn of 1.87 and a CTE of 49.4ppm/K. The delta D of the cycloolefin copolymer was 17.7MPa ^0.5 Delta P is 2.1MPa ^0.5 Delta H is 3.9MPa ^0.5 The meso form double bond/racemic form double bond was 0.19, and the refractive index was 1.538. The synthesis conditions of production example 1 are shown in table 2. This cycloolefin copolymer was dissolved in a toluene solution at a concentration of 2 mass% to obtain a cycloolefin copolymer solution 1.

[ Table 2]

[ production of cycloolefin copolymer crumbs ]

< production example 2>

611.7L of NB solution (NB concentration: 3.00 mol/L) was charged into the autoclave, the interior of which was dried under reduced pressure, and the temperature was raised to 60 ℃. While stirring the system, the ethylene partial pressure: after pressurization at 100kPa, 0.51L (concentration: 0.6 mol/L) of a hexane solution of TIBA, 40.8L (concentration: 1.0 mmol/L) of a toluene solution of AB and 2.0L (concentration: 10 mmol/L) of a toluene solution of a complex were added to start the polymerization of ethylene and NB. During the polymerization, the temperature in the system was maintained at 60 ℃ and ethylene was continuously supplied to maintain the pressure in the system at the initial value. After the amount of ethylene consumed reached 3.0kg from the start of the polymerization, 1.0L of water was added to stop the polymerization. To the direction ofA NaOH aqueous solution 612L (concentration: 0.1 mol/L) was added to the reaction vessel, and the mixture was stirred for 30 minutes. The stirring was stopped, the aqueous solution was drained, 612L of water was added, and stirring was carried out for 30 minutes. Further, 612L of water was added thereto, and after stirring for 30 minutes, a solution obtained by mixing 49.5L of acetone with 942L of toluene was added to the reaction vessel, and then 314L of acetone was added thereto, and the precipitated powder was separated by filtration. The separated powder was further washed with acetone and dried at 120 ℃ for 2 hours under reduced pressure to obtain 60.0kg of a cycloolefin copolymer. The cycloolefin copolymer obtained had an NB content of 92.3mol%, a Tg of 308 ℃ and an Mw of 852,000 and an Mw/Mn of 1.81. Further, the cycloolefin copolymer had a delta D of 17.7MPa ^0.5 Delta P is 2.1MPa ^0.5 Delta H is 3.9MPa ^0.5 The CTE was 44.5ppm/K.

The cycloolefin copolymer was pulverized by a reverse-jet mill manufactured by Hosokawa Micron Corporation and classified by a filter, thereby obtaining a pulverized powder of the cycloolefin copolymer as particles having a median particle diameter of 2.6. Mu.m.

[ production of cycloolefin copolymer solution 2]

< production example 3>

1,427mL of NB solution (NB concentration: 3.00 mol/L) and 55.2mL of styrene were added to an autoclave having its interior dried under reduced pressure, and the temperature was raised to 80 ℃. While stirring the system, 3.0mL (concentration: 1.0 mol/L) of a hexane solution of TIBA, 0.32g of AB, and 15.0mL (concentration: 10 mmol/L) of a toluene solution of a complex were added to start the polymerization of NB and styrene. During the polymerization, the temperature in the system was maintained at 80 ℃. After 2 hours had elapsed since the start of the polymerization, 3.0mL of water was added to stop the polymerization, and the solution in the autoclave was discharged. The obtained liquid was added dropwise to acetone with respect to the discharged solution, and the precipitated powder was separated by filtration. The separated powder was further washed with acetone and dried at 150 ℃ for 2 hours under reduced pressure to obtain 198.3g of a cycloolefin copolymer. The cycloolefin copolymer obtained had an NB content of 96.3mol%, an Mw of 79,000, an Mw/Mn of 1.83, a Tg of more than 300 ℃. Further, the cycloolefin copolymer had a delta D of 17.7MPa ^0.5 Delta P is 2.1MPa ^0.5 Delta H is 3.9MPa ^0.5 . Will be provided withThe synthesis conditions of production example 3 are shown in table 3. This cycloolefin copolymer was dissolved in a toluene solution at a concentration of 2 mass% to obtain a cycloolefin copolymer solution 2.

[ Table 3]

[ Synthesis of polyimide resin ]

< production example 4>

A reactor equipped with a silicone tube, a stirrer, and a thermometer in a separable flask, and an oil bath were prepared. After the flask was made to have a nitrogen atmosphere using dry nitrogen, 6FDA 75.52g and TFMB 54.44g were charged. While stirring at 400rpm, DMAc 519.84g was added and stirring was continued until the contents of the flask became a homogeneous solution. Then, the reaction was continued for 20 hours while adjusting the temperature in the container to a range of 20 to 30 ℃ by using an oil bath, and the reaction was allowed to proceed to produce polyamic acid. After 30 minutes, the stirring speed was changed to 100rpm. After stirring for 20 hours, the reaction system temperature was returned to room temperature, and DMAc 649.8g was added thereto so that the polymer concentration became 10 mass%. Further, 32.27g of pyridine and 41.65g of acetic anhydride were added thereto, and the mixture was stirred at room temperature for 10 hours to effect imidization. The polyimide varnish was taken out of the reaction vessel. The obtained polyimide varnish was dropped into methanol to reprecipitate, the obtained powder was dried by heating, and the solvent was removed to obtain a solid component, thereby obtaining a polyimide resin. The resulting polyimide resin had a delta D of 18.1MPa ^0.5 Delta P is 8.3MPa ^0.5 Delta H is 9.3MPa ^0.5 . The polyimide resin had an Mw of 334,300 and a Tg of 361 ℃.

[ Synthesis of Polyamic acid ]

< production example 5>

A reactor equipped with a silicone tube, a stirrer, and a thermometer in a separable flask, and an oil bath were prepared. The flask was charged with 27.83g of BPDA, 13.76g of PMDA, and 34.00g of m-TB. While stirring at 400rpm, DMAc 428.35g was added and stirring was continued until the contents of the flask became a homogeneous solution. Then, the reaction was continued for 3 hours while adjusting the temperature in the container to a range of 20 to 30 ℃ by using an oil bath, and the reaction was allowed to proceed to obtain a polyamic acid solution in a state of being dispersed in a solvent.

[ example 1]

100.0g of the cycloolefin copolymer solution obtained in production example 1 and 98.0g of GBL were mixed, and toluene was distilled off under reduced pressure at 50hPa and 80 ℃ so that the toluene content became 7 parts by mass based on 100 parts by mass of GBL, to obtain a particulate cycloolefin copolymer dispersion.

To 32.1g of the obtained dispersion (cycloolefin copolymer: 1.9% by mass) was added 1.9g of the polyimide resin obtained above to obtain a composition as a polyimide-cycloolefin copolymer mixed solution. The median particle diameter of the particulate cycloolefin copolymer in the dispersion and the composition measured by the above-mentioned method was 0.15. Mu.m. In the resulting composition, no aggregates of the cycloolefin copolymer having a size of more than 1mm were observed.

The obtained composition was cast on a glass substrate, and a coating film was formed at a linear speed of 0.4 m/min. The coating film was heated at 70 ℃ for 60 minutes to peel the film from the glass substrate, and then the film was fixed with a metal frame and further heated at 200 ℃ for 1 hour to obtain a polyimide-cycloolefin copolymer composite film having a thickness of 60 μm. The content of the particulate cycloolefin copolymer in the composite film obtained was 24 mass% based on the total mass of the polyimide resin and the particulate cycloolefin copolymer. Further, the CTE of the obtained composite film was 44ppm/K. The standard deviation of the average thickness of the obtained composite film was 0.4, and the smoothness of the film surface was also excellent. The haze of the obtained composite film was 44.8%.

The HSP value of the cycloolefin copolymer used in example 1 was 8.3 from the polyimide resin, the HSP value of the cycloolefin copolymer from toluene was 2.1, the HSP value of the polyimide resin from toluene was 10.0, the HSP value of the cycloolefin copolymer from GBL was 14.9, and the HSP value of the polyimide resin from GBL was 8.5.

According to the above evaluation method of solubility, the cycloolefin copolymer used in example 1 was dissolved in toluene without being dissolved in GBL. In addition, the polyimide resin is soluble in GBL, but not in toluene.

[ example 2]

A particulate cycloolefin copolymer dispersion was obtained in the same manner as in example 1 except that toluene was distilled off under reduced pressure at 50hPa and 80 ℃ so that the toluene content became 20 parts by mass with respect to 100 parts by mass of GBL, and the particulate cycloolefin copolymer dispersion was obtained.

To 35.9g of the obtained particulate cycloolefin copolymer dispersion (cycloolefin copolymer: 1.7% by mass) was added 1.9g of the polyimide resin obtained above as a polyimide-cycloolefin copolymer mixed solution to obtain a composition. The median particle diameter of the particulate cycloolefin copolymer in the dispersion and the composition measured by the above-mentioned method was 0.14. Mu.m. In the resulting composition, no aggregates of the cycloolefin copolymer having a size of more than 1mm were observed.

A polyimide-cycloolefin copolymer composite film having a thickness of 60 μm was obtained in the same manner as in example 1 except that the obtained composition was used. The content of the particulate cycloolefin copolymer in the composite film obtained was 24 mass% based on the total mass of the polyimide resin and the particulate cycloolefin copolymer. Further, the CTE of the obtained composite film was 44ppm/K. The standard deviation of the average thickness of the obtained composite film was 0.37, and the smoothness of the film surface was also excellent. The haze of the obtained composite film was 50.5%.

[ example 3]

A particulate cycloolefin copolymer dispersion was obtained in the same manner as in example 1 except that toluene was distilled off under reduced pressure at 50hPa and 80 ℃ so that the toluene content became 30 parts by mass with respect to 100 parts by mass of GBL, and the particulate cycloolefin copolymer dispersion was obtained.

To 38.8g (cycloolefin copolymer: 1.5% by mass) of the obtained particulate cycloolefin copolymer dispersion was added 1.9g of the polyimide resin obtained above as a polyimide-cycloolefin copolymer mixed solution to obtain a composition. The median particle diameter of the particulate cycloolefin copolymer in the dispersion and the composition measured by the above-mentioned method was 0.13. Mu.m. In the resulting composition, no aggregates of the cycloolefin copolymer having a size of more than 1mm were observed.

A polyimide-cycloolefin copolymer composite film having a thickness of 60 μm was obtained in the same manner as in example 1 except that the obtained composition was used. The content of the particulate cycloolefin copolymer in the composite film obtained was 24 mass% based on the total mass of the polyimide resin and the particulate cycloolefin copolymer. The CTE of the obtained composite film was 45ppm/K, and the smoothness of the film surface was also excellent. The haze of the obtained composite film was 65.7%.

[ example 4]

A dispersion was obtained by mixing 2.73g of a pulverized cycloolefin copolymer and 52.03g of DMAc and stirring the mixture. The toluene content of the obtained dispersion was 1.3 parts by mass with respect to 100 parts by mass of DMAc.

To the obtained dispersion, 100g of a polyamic acid solution (polyamic acid: 15% by mass) was added to obtain a composition as a polyamic acid-cycloolefin copolymer mixed solution. The median particle diameter of the particulate cycloolefin copolymer in the dispersion and the composition measured by the above-mentioned method was 2.6. Mu.m. In the resulting composition, no aggregates of the cycloolefin copolymer having a size of more than 1mm were observed.

The obtained composition was cast on a glass substrate, and a coating film was formed at a linear speed of 0.4 m/min. The coating film was heated at 50 ℃ for 80 minutes to peel the polyamic acid-cycloolefin copolymer composite film from the glass substrate, and then the film was fixed with a metal frame, and further heated at 360 ℃ for 15 minutes in a nitrogen atmosphere to imidize the polyamic acid, thereby obtaining a polyimide-cycloolefin copolymer composite film having a thickness of 50 μm. The content of the particulate cycloolefin copolymer in the obtained film was 15.4% by mass based on the total mass of the polyimide resin and the particulate cycloolefin copolymer. The CTE of the obtained composite film was 19ppm/K, and the smoothness of the film surface was also excellent. The haze of the obtained composite film was 98.9%.

The HSP value of the cycloolefin copolymer used in example 4 was 6.0 or more from the polyamic acid, and the HSP value of the cycloolefin copolymer was 11.5 from the DMAc. The HSP value of the cycloolefin copolymer used in example 4 and the HSP value of the polyimide resin obtained by imidizing the polyamic acid are 6.0 or more.

According to the above evaluation method of solubility, the cycloolefin copolymer used in example 4 was dissolved in toluene, but not in DMAc. In addition, the polyamic acid was soluble in DMAc, but not in toluene.

[ example 5]

5.69g of granular PTFE (manufactured by Polysciences Inc., melting point: 320 ℃ C., mw:20,000), 41.9g of DMAc, and 0.2g of toluene were mixed and stirred to obtain a dispersion. The toluene content of the obtained dispersion was 0.5 part by mass with respect to 100 parts by mass of DMAc.

To the obtained dispersion, 100g of a polyamic acid solution (polyamic acid 15 mass%) was added to obtain a composition as a polyamic acid-PTFE mixed solution. The median particle diameter of the particulate PTFE in the dispersion and composition measured by the above method was 3 μm. In the obtained composition, no agglomerates of PTFE larger than 1mm were observed.

The obtained composition was cast on a glass substrate, and a coating film was formed at a linear speed of 0.4 m/min. The coating film was heated at 50 ℃ for 80 minutes to peel the polyamic acid-PTFE composite film from the glass substrate, and then the film was fixed with a metal frame, and further, the polyamic acid-PTFE composite film was heated to 360 ℃ in stages for 30 minutes under a nitrogen atmosphere, whereby the polyamic acid was imidized to obtain a polyimide-PTFE composite film having a thickness of 50 μm. The content of the particulate PTFE in the film obtained was 27.5 mass% based on the total mass of the polyimide resin and the PTFE. The CTE of the obtained composite film was 17ppm/K, and the smoothness of the film surface was also excellent. The haze of the obtained composite film was 88.0%.

The HSP value of the polyamic acid and PTFE used in example 5 were 6.0 or more, and the HSP value of the DMAc and PTFE were 9.5. Further, the HSP value of the PTFE used in example 5 and the HSP value of the polyimide resin obtained by imidizing the polyamic acid are 6.0 or more.

The PTFE used in example 5 was insoluble in DMAc according to the above-described method for evaluating solubility. In addition, the polyamic acid was soluble in DMAc, but not in toluene.

[ example 6]

The resulting cycloolefin copolymer solution (2.0 g) was mixed with DMAc (98.0 g) and the toluene was distilled off under reduced pressure at 50hPa and 80 ℃ for 2 hours so that the toluene content became 0.6 part by mass based on 100 parts by mass of DMAc, thereby obtaining a particulate cycloolefin copolymer dispersion. The median particle diameter of the particulate cycloolefin copolymer in the particulate cycloolefin copolymer dispersion measured by the above-mentioned method was 0.13. Mu.m.

To 10.92g (2.0 mass% of the particulate cycloolefin copolymer) of the obtained particulate cycloolefin copolymer dispersion, 8.0g of a polyamic acid solution was added as a polyamic acid-cycloolefin copolymer mixed solution to obtain a composition. In the resulting composition, no aggregates of the cycloolefin copolymer having a size of more than 1mm were observed.

The obtained composition was cast on a glass substrate, and a coating film was formed at a linear speed of 0.4 m/min. The coating film was heated at 70 ℃ for 60 minutes to peel the polyamic acid-cycloolefin copolymer composite film from the glass substrate, and then the film was fixed with a metal frame, and further, the polyamic acid-cycloolefin copolymer composite film was heated to 360 ℃ in a nitrogen atmosphere in stages for 30 minutes, whereby the polyamic acid was imidized to obtain a polyimide-cycloolefin copolymer composite film having a thickness of 30 μm. The content of the particulate cycloolefin copolymer in the film obtained was 15.4% by mass based on the total mass of the polyimide resin and the particulate cycloolefin copolymer. The CTE of the obtained composite film was 18ppm/K, and the surface smoothness of the obtained composite film was also excellent. The haze of the obtained composite film was 96.6%.

The HSP value of the cycloolefin copolymer used in example 6 and the polyamic acid were 6.0 or more, the HSP value of the cycloolefin copolymer and toluene was 2.1, and the HSP value of the cycloolefin copolymer and DMAc was 11.5. The distance between the HSP value of the cycloolefin copolymer used in example 6 and the polyimide resin obtained by imidizing the polyamic acid was 6.0 or more.

According to the above evaluation method of solubility, the cycloolefin copolymer used in example 6 was dissolved in toluene without being dissolved in DMAc. The polyamic acid used in example 6 was dissolved in DMAc, but not in toluene.

[ comparative example 1]

A particulate cycloolefin copolymer dispersion was obtained in the same manner as in example 1 except that the toluene was distilled off under reduced pressure at 50hPa and 80 ℃ so that the toluene content became 40 parts by mass with respect to 100 parts by mass of GBL, and the particulate cycloolefin copolymer dispersion was obtained. The median particle diameter of the particulate cycloolefin copolymer in the dispersion and the composition measured by the above-mentioned method was 0.13. Mu.m.

To 41.8g of the obtained dispersion (cycloolefin copolymer: 1.4% by mass) was added 1.9g of the polyimide resin obtained above as a polyimide-cycloolefin copolymer mixed solution to obtain a composition. In the resulting composition, no aggregates of the cycloolefin copolymer having a size of more than 1mm were observed.

A polyimide-cycloolefin copolymer composite film having a thickness of 60 μm was obtained in the same manner as in example 1 except that the obtained composition was used. The content of the particulate cycloolefin copolymer in the composite film obtained was 24 mass% based on the total mass of the polyimide resin and the particulate cycloolefin copolymer. The CTE of the obtained composite film was 44ppm/K. In addition, the standard deviation of the average thickness of the obtained composite film was 1.77. The haze of the obtained composite film was 69.3%.

The haze and brightness of the polyimide-cycloolefin copolymer composite films and the polyimide-PTFE composite films obtained in the examples and comparative examples, and the water absorption of the composite films were measured in the above-described manner. The obtained results are shown in table 4. The lightness of the composite film was measured on both sides of the film, and the lightness of the surface in contact with the glass substrate at the time of film formation of the film was represented by L1, and the lightness of the surface opposite thereto was represented by L2. In the examples and comparative examples, the toluene content of the particulate cycloolefin copolymer dispersion and the particulate PTFE dispersion relative to 100 parts by mass of GBL or DMAc is also shown in table 4.

[ Table 4]

As shown in table 4, the films obtained in examples 1 to 6 had low water absorption and were superior in water absorption resistance to comparative example 1.

Claims

1. A film comprising a polyimide resin (A) and a particulate polymer (B), wherein the film has a haze of 75% or less and a lightness L of reflected light measured by a specular reflection light removal method ^* The number of the film is 37 or less on both sides.

2. A film comprising a polyimide resin (A) and a particulate polymer (B), wherein the film has a haze of more than 75% and a lightness L of reflected light measured by a specular reflection light removal method ^* The number of the film is 80 or less on both sides of the film.

3. The film according to claim 1 or 2, wherein the distance between the HSP value of the polyimide-based resin (A) and the HSP value of the polymer (B) is 6 or more.

4. The film according to any one of claims 1 to 3, wherein the particulate polymer (B) has an average primary particle diameter of 15 μm or less.

5. The film according to any one of claims 1 to 4, wherein the content of the particulate polymer (B) is 5 to 50% by mass based on the total mass of the polyimide resin (A) and the particulate polymer (B).

6. The film according to any one of claims 1 to 5, wherein the polymer (B) is at least 1 polymer selected from the group consisting of olefin-based polymers, polyimide-based polymers, fluorine-based polymers, silicone-based polymers, liquid crystal polymers, aramid polymers, styrene-based polymers, and ether-based polymers.

7. The film according to any one of claims 1 to 6, wherein the polymer (B) is a cycloolefin-based polymer.

8. The film according to any one of claims 1 to 7, wherein at least one of the glass transition temperature and the melting point of the polymer (B) is 100 ℃ or higher.

9. The film according to claim 7 or 8, wherein the cycloolefin-based polymer comprises a monomer unit (1) derived from a cycloolefin represented by the formula (I),

[ chemical formula 1]

In the formula (I), m represents an integer of 0 or more, R ⁷ ～R ¹⁸ Independently of one another, a hydrogen atom, a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms in R ¹¹ ～R ¹⁴ When there are plural, they may be the same or different, and R ¹⁶ And R ¹⁷ May be bonded to each other and form a ring together with the carbon atom to which they are bonded.

10. A composition comprising a polyimide resin (A), a particulate polymer (B) and a solvent,

the solvent includes a 1 st solvent and a 2 nd solvent, and the HSP value of the 2 nd solvent and the particulate polymer (B) is 8.5 or more.