film

Abstract

To provide a film excellent in water absorption resistance, and a composition which enables formation of the film.SOLUTION: A film contains a polyimide-based resin (A) and a particulate polymer (B), in which the film has a haze of 75% or less, and brightness L* of reflection light measured by a regular reflection light removal method is 37 or less on both sides of the film.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a film that can be used as a substrate material for high-frequency band printed circuit boards and antenna substrates, and a composition that can form the film. [Background technology]

[0002] With the widespread adoption of fifth-generation mobile communication systems, known as 5G, there is a demand for printed circuits and printed wiring boards that can be used for antennas and are compatible with high-frequency bands. However, at high frequencies, transmission loss due to the substrate material becomes significantly more pronounced, making it important to select substrate materials that can reduce transmission loss. For example, copper-clad laminates (CCLs) have a structure in which copper foil is laminated on both surfaces of a resin layer via an adhesive. Since the transmission loss of CCLs can be reduced by reducing the dielectric loss, particularly the dielectric loss tangent and relative permittivity, of the resin layer that serves as the transmission path, films with low dielectric loss tangents have been investigated. 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 with a low dielectric loss tangent formed from the composition. However, even films formed from the low-dielectric resin composition described in Patent Document 1 do not necessarily achieve a sufficient reduction in dielectric loss tangent. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-125176 Summary of the Invention [Problem to be solved by the invention]

[0004] The present inventors have conducted further studies on reducing the dielectric loss tangent and have found that the film formed from the low dielectric resin composition described in Patent Document 1 may not have sufficient water absorption resistance.

[0005] Therefore, an object of the present invention is to provide a film having excellent resistance to water absorption and a composition capable of forming such a film. [Means for solving the problem]

[0006] As a result of extensive research to solve the above problems, the present inventors have surprisingly found that in a film containing a polyimide-based resin (A) and a particulate polymer (B), the brightness L of reflected light measured by a specular reflection elimination method of the film is * The present inventors have found that the water absorption resistance of the film can be improved when the σ is 37 or less on both sides of the film, and have completed the present invention.

[0007] That is, the present invention includes the following preferred embodiments. [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 reflected light brightness L measured by a specular reflection elimination method. * is 37 or less on both sides of the film. [2] A film comprising a polyimide-based resin (A) and a particulate polymer (B), wherein the film has a haze of more than 75% and a reflected light brightness L measured by a specular reflection excluding method. * is 80 or less on both sides of the film. [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 particulate polymer (B) has an average primary particle size of 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 mass % based on the total mass of the polyimide resin (A) and the particulate polymer (B). [6] The film according to any one of [1] to [5], wherein the polymer (B) is at least one polymer selected from the group consisting of an olefin-based polymer, a polyimide-based polymer, a fluorine-based polymer, a silicone-based polymer, a liquid crystal polymer, an aramid polymer, a styrene-based polymer, and an ether-based polymer. [7] The film according to any one of [1] to [6], wherein the polymer (B) is a cycloolefin-based polymer. [8] 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° C. or higher. [9] The cycloolefin polymer is represented by the formula (I): [ka] [In formula (I), m represents an integer of 0 or more, and R 7 ~R 18 each independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms; R 11 ~R 14 When there are multiple R 16 and R 17 may be bonded to each other to form a ring together with the carbon atoms to which they are attached. The film according to [7] or [8], which contains a cycloolefin-derived monomer unit (1) represented by the following formula:

[10] A composition comprising a polyimide resin (A), a particulate polymer (B), and a solvent, The composition comprises a first solvent and a second solvent, and the distance between the HSP values ​​of the second solvent and the particulate polymer (B) is 8.5 or more. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a film having excellent resistance to water absorption and a composition capable of forming the film. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail. Note that the scope of the present invention is not limited to the embodiments described here, and various modifications can be made without departing from the spirit of the present invention.

[0010] 〔film〕 The film of the present invention contains a polyimide-based resin (A) and a particulate polymer (B), and when the haze is 75% or less, the brightness L of reflected light measured by a specular reflection excluding method is * (hereinafter, sometimes simply referred to as "brightness") is 37 or less on both sides of the film, and when the film contains a polyimide-based resin (A) and a particulate polymer (B) and the haze exceeds 75%, the brightness L of the reflected light measured by the specular reflection light elimination method is * is 80 or less on both sides of the film.

[0011] The present inventors have conducted further studies on the water absorption resistance of films and have unexpectedly discovered that the water absorption resistance of a film can change depending on the relationship between the haze and brightness of the film. Therefore, the present inventors have conducted further studies focusing on the brightness of the film and have found that a film with excellent water absorption resistance can be obtained by adjusting the brightness of a film with a haze of 75% or less to 37 or less on both sides of the film, and that a film with excellent water absorption resistance can be obtained by adjusting the brightness of a film with a haze of more than 75% to 80 or less on both sides of the film.

[0012] On the other hand, if the brightness of at least one side of a film with a haze of 75% or less exceeds 37, the water absorption resistance of the film tends to decrease. Also, if the brightness of at least one side of a film with a haze of more than 75% exceeds 80, the water absorption resistance of the film tends to decrease. When a film absorbs water, its dielectric properties tend to decrease.

[0013] In one embodiment of the present invention, the brightness of a film having a haze of 75% or less is preferably 36.5 or less, more preferably 36 or less, even more preferably 34 or less, and particularly preferably 32 or less, on both sides. When the brightness is below the upper limit, the water absorption resistance of the film is easily improved. Furthermore, the brightness of the film is preferably 10 or more, more preferably 20 or more, and even more preferably 25 or more, on both sides. When the brightness is above the lower limit, the film is less likely to become curled, for example, when stored in a rolled state. The brightness of reflected light measured by the specular reflection exclusion (SCE) of the present invention can be measured using a spectrophotometer, for example, by the method described in the Examples. The haze of the film can be measured using a haze meter based on JIS K 7136, for example, by the method described in the Examples.

[0014] In another embodiment of the present invention, the brightness of a film having a haze of more than 75% is preferably 78.5 or less, more preferably 78 or less, even more preferably 76 or less, still more preferably 73 or less, and particularly preferably 72 or less, on both sides. When the brightness is equal to or less than the above upper limit, the water absorption resistance of the film is easily improved. Furthermore, the brightness of the film is preferably 30 or more, more preferably 40 or more, even more preferably 48 or more, still more preferably 50 or more, and particularly preferably 55 or more, on both sides. When the brightness is equal to or more than the above lower limit, the film is less likely to become curled, for example, when stored in a roll.

[0015] The brightness of the film can be adjusted by appropriately adjusting the film composition, such as the type, composition ratio, and molecular weight of the structural units constituting the polyimide resin (A) and / or polymer (B) contained in the film, the content and particle size of the particulate polymer (B) in the film, and the film manufacturing conditions. For example, the brightness of the film can be adjusted to within the above range by selecting the type of polymer (B), the type and composition ratio of the structural units constituting the polyimide resin (A) and / or polymer (B), the content and particle size of the particulate polymer (B), and the film manufacturing method, as described below as preferred embodiments. In particular, when the film is formed by the preferred manufacturing method described below, the brightness of the film can be easily adjusted to within the above range. In this specification, unless otherwise specified, the term "particle size" includes the average primary particle size and / or median diameter of the particulate polymer (B).

[0016] <Polymer (B)> The polymer (B) is a polymer different from the polyimide resin (A). When the polymer (B) is a polyimide resin, it may be a polyimide resin of a different type from the polyimide resin (A), for example, a polyimide resin having a different type or content of monomer units constituting the resin.

[0017] The polymer (B) is not particularly limited, and examples thereof include olefin-based polymers, polyimide-based polymers, fluorine-based polymers, silicone-based polymers, liquid crystal polymers, aramid polymers, styrene-based polymers, and ether-based polymers. The polymer (B) can be used alone or in combination. Using these polymers as the polymer (B) facilitates reducing the particle size of the polymer (B) and improving its dispersibility. Furthermore, using these polymers as the polymer (B) facilitates reducing the brightness and coefficient of linear expansion (hereinafter sometimes referred to as CTE) of the resulting film, while enhancing the film's dielectric properties and water absorption resistance. Among these, at least one polymer selected from the group consisting of olefin-based polymers, polyimide-based polymers, fluorine-based polymers, liquid crystal polymers, styrene-based polymers, and ether-based polymers is preferred, with olefin-based polymers being more preferred. At least one polymer selected from the group consisting of polyethylene, high-density polyethylene, polypropylene, polymethylpentene, and cycloolefin-based polymers is even more preferred, with cycloolefin-based polymers being particularly preferred. In addition, in this specification, the term "dielectric properties" refers to dielectric properties including dielectric loss, dielectric constant, and dielectric loss tangent, and "enhancing or improving the dielectric properties" means, for example, that the dielectric loss, dielectric constant, and / or dielectric loss tangent are reduced.

[0018] In a preferred embodiment of the present invention, the cycloolefin-based polymer is a polymer represented by formula (I): [ka] [In formula (I), m represents an integer of 0 or more, R 7 ~R 18 each independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms; R 11 ~R 14 When there are multiple R 16 and R 17 may be bonded to each other to form a ring together with the carbon atoms to which they are attached. It is preferable that the particulate polymer (B) contains a cycloolefin-derived monomer unit (I) represented by the following formula: Hereinafter, the "particle size of the particulate polymer (B)" may be simply referred to as the "particle size".

[0019] In formula (I), m is an integer of 0 or more. From the viewpoints of facilitating reduction of the particle size and CTE, facilitating improvement of the water absorption resistance and heat resistance of the film, and ease of availability, the upper limit of m is preferably an integer of 3 or less, more preferably an integer of 2 or less, and even more preferably an integer of 1 or less.

[0020] R 7 ~R 18 Examples of the hydrocarbon group having 1 to 20 carbon atoms that is a member of the substituent include alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, octyl, and dodecyl; aryl groups such as phenyl, tolyl, and naphthyl; aralkyl groups such as benzyl and phenethyl; and groups in which some of the hydrogen atoms of the above alkyl, aryl, and aralkyl groups have been substituted with halogen atoms. Among these, alkyl, aryl, and aralkyl groups are preferred from the viewpoints of easily improving the water absorption resistance, dielectric properties, and heat resistance of the film and easily reducing the CTE of the film. That is, R 7 ~R 18 is 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.

[0021] Examples of cycloolefins represented by 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 these, norbornene is preferred from the viewpoints of easy availability of raw material monomers, reduction of particle size and CTE of the film, and improvement of heat resistance of the film. The cycloolefins represented by formula (I) may be used alone or in combination of two or more.

[0022] In one embodiment of the present invention, the cycloolefin polymer preferably contains a double chain structure of the monomer unit (I). By containing the double chain structure, the heat resistance is more likely to be improved than that of a polymer having a similar content of the monomer unit (I). The presence or absence of the double chain structure can be determined by the following: 13 It can be determined by C-NMR spectrum analysis. For example, in the case of a tetracyclodecene-ethylene copolymer, signals derived from an ethylene-tetracyclodecene-ethylene sequence, which is an isolated chain of tetracyclodecene, appear around 54.7 ppm and around 51.1 ppm, signals derived from an ethylene-tetracyclodecene-tetracyclodecene-ethylene sequence, which is a two-chain tetracyclodecene of endo-exo bonds, appear around 51.5 ppm and around 50.8 ppm, and signals derived from an ethylene-tetracyclodecene-tetracyclodecene-ethylene sequence of exo-exo bonds appear around 55.3 ppm and around 54.3 ppm, so it can be determined from the signal patterns around 55 ppm and around 50 ppm.

[0023] The di-chain structure of the monomer unit (I) includes a meso-type di-chain represented by the following structural formula (II-1) or the following structural formula (II-2), and / or a racemo-type di-chain represented by the following structural formula (III-1) or the following structural formula (III-2).

[0024] [ka]

[0025] The ratio of meso-type di-chains to racemo-type di-chains (hereinafter sometimes referred to as meso-type di-chains / racemo-type di-chains) is preferably 0.50 or less, more preferably 0.40 or less, even more preferably 0.30 or less, particularly preferably 0.20 or less, and preferably 0.01 or more, more preferably 0.05 or more. When the ratio of meso-type di-chains to racemo-type di-chains is within the above range, the mechanical properties and heat resistance of the film are easily improved. The ratio of meso-type di-chains to racemo-type di-chains can be, for example, 13 Using C-NMR, the ratio can be calculated based on the assignments described in "RAWendt, G. Fink, Macromol. Chem. Phys., 2001, 202, 3490" and "JP 2008-285656 A," specifically, by the method described in the Examples. One method for adjusting the meso-type double chain and racemo-type double chain ratios within the above ranges is to select a catalyst having an appropriate ligand size relative to the bulkiness of the monomer. For example, the catalyst described in JP 9-183809 A can be used as the catalyst. In this specification, "mechanical properties" refers to mechanical properties including flexural strength and elastic modulus, and "increased or improved mechanical properties" refers to, for example, increased flexural strength and / or elastic modulus.

[0026] The content of the monomer unit (I) in the cycloolefin polymer is preferably 60 mol% or more, more preferably 65 mol% or more, even more preferably 70 mol% or more, particularly preferably 75 mol% or more, and preferably 100 mol% or less, more preferably 99 mol% or less, and even more preferably 98 mol% or less, relative to the total molar amount of repeating units constituting the cycloolefin polymer. When the content of the monomer unit (I) is equal to or greater than the above lower limit, the glass transition temperature (hereinafter sometimes referred to as Tg) is easily increased, thereby easily reducing the CTE of the film, and the brightness of the film is easily reduced, thereby easily improving the water absorption resistance. Furthermore, the heat resistance and mechanical properties such as flex resistance of the film are easily improved. When the content of the monomer unit (I) is equal to or less than the above upper limit, mechanical properties such as flex resistance are easily improved. The content of the monomer unit (I) is 13 Using C-NMR, calculation can be made based on the assignments described in "RAWendt, G. Fink, Macromol. Chem. Phys., 2001, 202, 3490", for example, by the method described in the Examples.

[0027] From the viewpoint of easily reducing the CTE of the film and easily improving mechanical properties such as water absorption resistance and flex resistance, the cycloolefin polymer preferably contains a monomer unit (II) derived from at least one selected from the group consisting of ethylene, linear α-olefins having 3 to 20 carbon atoms, and aromatic vinyl compounds having 8 to 20 carbon atoms, and more preferably contains a monomer unit (II) derived from ethylene.

[0028] Examples of linear α-olefins having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene. Among these, propylene, 1-butene, 1-hexene, or 1-octene is preferred, and propylene is more preferred, from the viewpoints of easily reducing the CTE of the film and easily improving mechanical properties such as water absorption resistance and flex resistance. One type of linear α-olefin having 3 to 20 carbon atoms may be used alone, or two or more types may be used in combination. Note that the term "linear α-olefin" refers to a linear olefin having a carbon-carbon unsaturated double bond at the α-position.

[0029] Examples of aromatic vinyl compounds having 8 to 20 carbon atoms include styrene, methylstyrene, dimethylstyrene, ethylstyrene, tert-butylstyrene, vinylnaphthalene, vinylanthracene, diphenylethylene, isopropenylbenzene, isopropenyltoluene, isopropenylethylbenzene, isopropenylpropylbenzene, isopropenylbutylbenzene, isopropenylpentylbenzene, isopropenylhexylbenzene, isopropenyloctylbenzene, isopropenylnaphthalene, and isopropenylanthracene. Among these, from the viewpoints of easy availability of raw material monomers, ease of reducing the CTE of the film, and ease of improving mechanical properties such as flexural resistance, styrene, methylstyrene, or dimethylstyrene is preferred, and styrene is more preferred. The aromatic vinyl compounds having 8 to 20 carbon atoms may be used alone or in combination of two or more.

[0030] In one embodiment of the present invention, from the viewpoints of easy availability of raw material monomers, ease of reducing the CTE of the film, and ease of improving mechanical properties such as flexural resistance, the cycloolefin-based polymer preferably contains monomer units (II) derived from at least one selected from the group consisting of ethylene, propylene, and styrene, more preferably monomer units (II) derived from at least one selected from the group consisting of ethylene and styrene.

[0031] The content of the monomer unit (II) in the cycloolefin polymer is preferably 0 mol% or more, more preferably 0.01 mol% or more, even more preferably 1 mol% or more, still more preferably 2 mol% or more, and preferably 40 mol% or less, more preferably 35 mol% or less, even more preferably 30 mol% or less, and particularly preferably 25 mol% or less, relative to the total molar amount of repeating units constituting the cycloolefin polymer. When the content of the monomer unit (II) is equal to or greater than the above-mentioned lower limit, the mechanical properties such as flex resistance of the film, as well as processability and moldability, are likely to be improved. When the content of the monomer unit (II) is equal to or less than the above-mentioned upper limit, the CTE of the film is likely to be reduced, and mechanical properties such as water absorption resistance, heat resistance, and flex resistance are likely to be improved.

[0032] In one embodiment of the present invention, from the viewpoint of easily improving mechanical properties such as heat resistance, processability, and flex resistance, as well as water absorption resistance, and easily reducing particle size and CTE, the cycloolefin-based polymer is preferably a cycloolefin-based copolymer, more preferably a cycloolefin-based copolymer containing monomer units (I) derived from cycloolefin represented by formula (I) and monomer units (II) derived from at least one selected from the group consisting of ethylene, linear α-olefins having 3 to 20 carbon atoms, and aromatic vinyl compounds having 8 to 20 carbon atoms, and even more preferably an ethylene-norbornene copolymer containing monomer units (I) derived from norbornene and monomer units (II) derived from ethylene, or a styrene-norbornene copolymer containing monomer units (I) derived from norbornene and monomer units (II) derived from styrene.

[0033] The cycloolefin polymer may contain other monomer units (III). Examples of other monomers constituting the other monomer units (III) include conjugated dienes such as butadiene or isoprene; non-conjugated dienes such as 1,4-pentadiene; acrylic acid; acrylic acid esters such as methyl acrylate or ethyl acrylate; methacrylic acid; methacrylic acid esters such as methyl methacrylate or ethyl methacrylate; and vinyl acetate. The other monomer units (III) can be used alone or in combination of two or more. The polymer (B) may be used alone or in combination of two or more kinds.

[0034] In one embodiment of the present invention, examples of the olefin-based polymer other than the cycloolefin-based polymer include polymers or copolymers containing the monomer unit (II); the monomer unit (III); at least one 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. Polyethylene, high-density polyethylene, polypropylene, or polymethylpentene is preferred, and among these, polypropylene or polymethylpentene is more preferred from the viewpoint of improving heat resistance.

[0035] In one embodiment of the present invention, the polyimide-based polymer may be, for example, a polyimide-based polymer that is soluble in the first solvent.

[0036] In one embodiment of the present invention, the fluoropolymer is a fluorine-containing olefin polymer or a modified product thereof, and specific examples include polymers and copolymers containing at least one monomer unit selected from the group consisting of fluoroolefins, such as tetrafluoroethylene, trifluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinylidene fluoride, vinyl fluoride, etc., such as polytetrafluoroethylene (hereinafter sometimes referred to as PTFE), perfluoroalkoxyalkane, perfluoroethylenepropene copolymer, ethylene-tetrafluoroethylene copolymer, polyvinylidene fluoride, polychlorotrifluoroethylene, polyhexafluoropropylene, etc. From the viewpoint of improving the dielectric properties of the film, the fluoropolymer is preferably a polymer having tetrafluoroethylene-derived structural units, and more preferably, the molar ratio of tetrafluoroethylene-derived structural units to the total of all structural units is 0.25 or more, even more preferably 0.30 or more, even more preferably 0.50 or more, and particularly preferably 0.75 or more. The molar ratio of each constituent unit of the fluoropolymer can be determined by NMR measurement, and for calculating the molar ratio, reference can be made to, for example, Eric B. Twum et al., "Multidimensional 19F NMR Analyses of Terpolymers from Vinylidene Fluoride (VDF)-Hexafluoropropylene (HFP)-Tetrafluoroethylene (TFE)," Macromolecules, 2015, Vol. 48, No. 11, pp. 3563-3576. Furthermore, from the viewpoint of improving solubility in the first solvent, the fluoropolymer may be a copolymer of the monomer unit with at least one selected from the group consisting of vinyl ethers, vinyl esters, and allyl ethers.

[0037] In one embodiment of the present invention, examples of the liquid crystal polymer include polymers having, as repeating units, aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aliphatic diols, and the like. Specific examples of monomers that provide aromatic hydroxycarboxylic acid repeating units include aromatic hydroxycarboxylic acids such as parahydroxybenzoic acid, metahydroxybenzoic acid, orthohydroxybenzoic 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, as well as alkyl, alkoxy, or halogen-substituted derivatives thereof and ester-forming derivatives thereof. Among these, parahydroxybenzoic acid and 6-hydroxy-2-naphthoic acid are preferred from the viewpoint of easily improving the water absorption resistance, mechanical properties, and heat resistance of the film.

[0038] Specific examples of monomers that provide aromatic dicarboxylic acid repeating units 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, and 4,4'-dicarboxybiphenyl, as well as alkyl, alkoxy, or halogen-substituted derivatives thereof, and ester-forming derivatives thereof. Among these, terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid are preferred from the viewpoint of easily improving the water absorption resistance, mechanical properties, and heat resistance of the film.

[0039] Specific examples of monomers that provide aromatic diol repeating units 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'-dihydroxybiphenyl ether, alkyl-, alkoxy-, or halogen-substituted versions of these, and ester-forming derivatives of these. Among these, hydroquinone and 3,3'-dihydroxybiphenyl are preferred from the viewpoint of easily improving the water absorption resistance, mechanical properties, and heat resistance of the film.

[0040] Specific examples of monomers that provide aliphatic diol repeating units include aliphatic diols such as ethylene glycol, 1,4-butanediol, and 1,6-hexanediol, as well as acylated products thereof. Among these, ethylene glycol is preferred from the viewpoint of easily improving the water absorption resistance, mechanical properties, and heat resistance of the film.

[0041] In one embodiment of the present invention, the styrene-based polymer is a resin containing at least one styrene in the repeating structural unit, such as polystyrene, ABS resin (acrylonitrile-butadiene-styrene copolymer), AS resin (acrylonitrile-styrene copolymer), etc. Among them, polystyrene is preferred from the viewpoint of ease of improving dielectric properties.

[0042] In one embodiment of the present invention, the ether-based polymer is a resin containing at least one repeating unit containing an ether group in the main chain, and examples thereof include polyetherimide, polyphenylene ether, polyethersulfone, polyetherketone, polyetheretherketone, etc. Among these, polyphenylene ether, polyethersulfone, and polyetheretherketone are preferred from the viewpoint of easily improving the water absorption resistance and dielectric properties of the film.

[0043] In one embodiment of the present invention, the weight-average molecular weight (hereinafter, sometimes abbreviated as Mw) of polymer (B) is preferably 10,000 or more, more preferably 15,000, even more preferably 20,000 or more, even more preferably 30,000 or more, particularly preferably 50,000 or more, especially more preferably 70,000 or more, especially even more preferably 90,000 or more, and is preferably 2,000,000 or less, more preferably 1,000,000 or less, even more preferably 700,000 or less. When Mw is equal to or greater than the above lower limit, the water absorption resistance and heat resistance of the film are easily improved, and the strength is easily improved. When Mw is equal to or less than the above upper limit, the water absorption resistance, mechanical properties, and formability of the film are easily improved.

[0044] In one embodiment of the present invention, the ratio (Mw / Mn) of Mw to number average molecular weight (hereinafter, number average molecular weight may be abbreviated as Mn) of polymer (B) is preferably 2.5 or less, more preferably 2.2 or less, even more preferably 2.0 or less, even more preferably 1.95 or less, particularly preferably 1.90 or less, and preferably 1.30 or more, more preferably 1.50 or more, even more preferably 1.60 or more, particularly preferably 1.65 or more. When the Mw / Mn ratio is below the above upper limit, the water absorption resistance and mechanical properties of the film are easily improved, while when it is above the above lower limit, the formability is easily improved. Note that Mw and Mn can be determined by gel permeation chromatography (hereinafter, sometimes abbreviated as GPC) measurement and standard polystyrene equivalent, for example, by the method described in the Examples.

[0045] In one embodiment of the present invention, from the viewpoint of easily obtaining a film with a reduced CTE, the refractive index of polymer (B) is preferably 1.600 or less, more preferably 1.570 or less, even more preferably 1.550 or less, and is preferably 1.500 or more, more preferably 1.520 or more. The refractive index of polymer (B) can be measured with a refractometer, for example, by the method described in the Examples.

[0046] In one embodiment of the present invention, the CTE of polymer (B) is preferably 110 ppm / K or less, more preferably 80 ppm / K or less, even more preferably 58 ppm / K or less, even more preferably 55 ppm / K or less, particularly preferably 50 ppm / K or less, and preferably 0 ppm / K or more, more preferably 0.01 ppm / K or more, even more preferably 1 ppm / K or more, and even more preferably 5 ppm / K or more. When the CTE of polymer (B) is below the above upper limit, the CTE of the resulting film is easily reduced. Furthermore, when bonding with copper foil to produce a copper-clad laminate, it is preferable to adjust the CTE of the film to around 20 ppm / K from the viewpoint of preventing peeling of the laminate film. A polymer (B) having an optimal CTE can be selected depending on the CTE of the resin to be mixed. The CTE can be measured, for example, by thermomechanical analysis (hereinafter sometimes referred to as TMA) and is determined by the method described in the Examples.

[0047] In one embodiment of the present invention, at least one of the glass transition temperature and melting point of polymer (B) is preferably 100°C or higher. The Tg of polymer (B) is preferably 100°C or higher, more preferably 140°C or higher, even more preferably 160°C or higher, even more preferably 180°C or higher, particularly preferably 200°C or higher, especially more preferably 220°C or higher, especially even more preferably 240°C or higher, and most preferably 260°C or higher, and is preferably 500°C or lower, more preferably 400°C or lower, even more preferably 350°C or lower, and even more preferably 320°C or lower. Furthermore, when polymer (B) is a crystalline polymer having a melting point, the melting point of polymer (B) is preferably 100°C or higher, more preferably 140°C or higher, even more preferably 160°C or higher, even more preferably 180°C or higher, particularly preferably 200°C or higher, especially more preferably 220°C or higher, especially even more preferably 240°C or higher, and most preferably 260°C or higher, and is preferably 500°C or lower, more preferably 400°C or lower, and even more preferably 350°C or lower. When at least one of the Tg and melting point of polymer (B) is above the lower limit, the CTE of the film is likely to be reduced, and mechanical properties such as water absorption resistance, heat resistance, and flex resistance are likely to be improved. When at least one of the Tg and melting point of polymer (B) is below the upper limit, the mechanical properties of the film, particularly repeated flex resistance, are likely to be improved. The Tg of polymer (B) is the softening temperature measured by TMA in accordance with JIS K 7196, and can be measured, for example, by the method described in the Examples. The method for adjusting the Tg and melting point of polymer (B) is not particularly limited, and examples include methods of appropriately adjusting the content of monomer unit (I), Mw, crystallinity, etc. of polymer (B). The Tg and melting point of polymer (B) tend to increase as at least one selected from the group consisting of the content of monomer unit (I), Mw, and crystallinity of polymer (B) increases. The melting point of the polymer (B) can be determined, for example, by using a differential scanning calorimeter (DSC, manufactured by Hitachi High-Tech Science Corporation) and measuring the melting peak temperature from the resulting melting curve.

[0048] In one embodiment of the present invention, the average primary particle size of the particulate polymer (B) is preferably 15 μm or less, more preferably 10 μm or less, even more preferably 5 μm or less, even more preferably 3 μm or less, particularly preferably 1 μm or less, especially more preferably 0.8 μm or less, especially more preferably 0.5 μm or less, and preferably 0.01 μm or more, more preferably 0.03 μm or more, and even more preferably 0.05 μm or more. When the average primary particle size of the particulate polymer (B) is equal to or greater than the above-mentioned lower limit, the mechanical properties of the film are easily improved. When the average primary particle size of the particulate polymer (B) is equal to or less than the above-mentioned upper limit, the particle dispersibility of the particulate polymer (B) is improved and the brightness is easily reduced. As a result, the water absorption resistance of the film is easily improved, and mechanical properties such as the surface smoothness and flex resistance of the film are easily improved. The average primary particle size of the particulate polymer (B) can be determined by image analysis of images taken with an electron microscope. For example, a cross section of the film is observed using a scanning transmission electron microscope (STEM), the particle sizes of 50 or more particles are measured from the observed image, and the average value thereof can be used as the average primary particle size of the particulate cycloolefin copolymer.

[0049] The content of the particulate polymer (B) is typically 1% by mass or more, preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, particularly preferably 20% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 35% by mass or less, particularly preferably 30% by mass or less, based on 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 above the above-mentioned lower limit, the particle dispersibility in the film is easily improved, which makes it easy to reduce the brightness of the film and also to improve the water absorption resistance, surface smoothness, and mechanical properties. When the content of the particulate polymer (B) is below the above-mentioned upper limit, the brightness of the film is easily reduced and the moldability is easily improved. Furthermore, high particle dispersibility in the film increases the uniformity of the thermal conductivity and CTE, and therefore, when the film is used as a resin layer of a CCL, for example, peeling between the film and copper foil is easily suppressed.

[0050] <Method for producing polymer (B)> The polymer (B) may be a commercially available product or may be produced by a conventional method. In one embodiment of the present invention, the polymer (B) is preferably a cycloolefin-based polymer. The method for producing the cycloolefin-based polymer is not particularly limited. For example, the cycloolefin-based polymer is preferably produced by polymerizing a monomer for forming the cycloolefin-based polymer, such as the cycloolefin represented by formula (I), at least one monomer selected from the group consisting of ethylene, linear α-olefins having 3 to 20 carbon atoms, and aromatic vinyl compounds having 8 to 20 carbon atoms, and optionally other monomers, in the presence of a catalyst containing a transition metal complex (α) represented by formula (IV) as one component. In the production of the cycloolefin-based polymer of the present invention, the use of the transition metal complex (α) represented by formula (IV) makes it easy to significantly increase the content of the monomer unit (I) in the cycloolefin-based polymer and to adjust the Tg within the above range.

[0051] [ka] [In 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 in group 16 of the periodic table of elements, T represents an atom in group 14 of the periodic table of elements, D 1 and D 2 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, or a di-substituted amino group having 2 to 20 carbon atoms, which may be the same or different. R 1 ~R 6represents 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 di-substituted amino group having 2 to 20 carbon atoms, or a silyl group having 1 to 20 carbon atoms, which may be the same or different, and which may be optionally bonded to form a ring.

[0052] M is a transition metal element of Group 4 of the Periodic Table of the Elements (IUPAC Inorganic Chemistry Nomenclature Revised Edition 1989), and examples thereof include a titanium atom, a zirconium atom, and a hafnium atom.

[0053] Cp is a group having a cyclopentadienyl skeleton, and examples thereof include cyclopentadienyl, substituted cyclopentadienyl, indenyl, substituted indenyl, fluorenyl, and substituted fluorenyl. Specific examples thereof include a cyclopentadienyl group, a methylcyclopentadienyl group, a tetramethylcyclopentadienyl group, an n-propylcyclopentadienyl group, an n-butylcyclopentadienyl group, an isobutylcyclopentadienyl group, a phenylcyclopentadienyl group, an indenyl group, a methylindenyl group, an n-propylindenyl group, an n-butylindenyl group, an isobutylindenyl group, a phenylindenyl group, a fluorenyl group, a methylfluorenyl group, an n-propylfluorenyl group, a phenylfluorenyl group, and a dimethylfluorenyl group. Of these, preferred are a cyclopentadienyl group, a methylcyclopentadienyl group, a tetramethylcyclopentadienyl group, an n-butylcyclopentadienyl group, an isobutylcyclopentadienyl group, an indenyl group, a methylindenyl group, and a fluorenyl group.

[0054] A is an atom of Group 16 of the periodic table of elements, such as an oxygen atom, a sulfur atom, etc. Among these, an oxygen atom is preferred.

[0055] T is an atom of Group 14 of the periodic table of elements, such as a carbon atom, a silicon atom, a germanium atom, etc. Among these, a carbon atom or a silicon atom is preferred.

[0056] D 1 , D 2 are each independently 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 di-substituted amino group having 2 to 20 carbon atoms, and may be the same or different. Among these, a halogen atom is preferred.

[0057] D 1 , D 2 When is a halogen atom, specific examples include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0058] D 1 , D 2 When is a hydrocarbon group, the number of carbon atoms therein is preferably 1 to 10. Examples of the hydrocarbon group 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 neopentyl group, an n-hexyl group, an 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.

[0059] D 1 , D 2Specific examples of when is a halogenated hydrocarbon group include a fluoromethyl group, a difluoromethyl group, a 1-fluoroethyl group, a 1,1-difluoroethyl group, a 1,2-difluoroethyl group, a 1,1,2-trifluoroethyl group, a tetrafluoroethyl group, a chloromethyl group, a dichloromethyl group, a 1-chloroethyl group, a 1,1-dichloroethyl group, a 1,2-dichloroethyl group, a 1,1,2-trichloroethyl group, a 1,1,2,2-tetrachloroethyl group, a bromomethyl group, a dibromomethyl group, a 1-bromomethyl group, a bromoethyl group, 1,1-dibromoethyl group, 1,2-dibromoethyl group, 1,1,2-tribromoethyl group, 1,1,2,2-tetrabromoethyl group, 2-fluorophenyl group, 3-fluorophenyl group, 4-fluorophenyl group, 2,3-difluorophenyl group, 2,4-difluorophenyl group, 2,5-difluorophenyl group, 2,6-difluorophenyl group, 2,3,4-trifluorophenyl group, 2,3,5-trifluorophenyl group, 2,3,6-trifluorophenyl group, 2,3, 4,5-tetrafluorophenyl group, 2,3,4,6-tetrafluorophenyl group, pentafluorophenyl group, 2-chlorophenyl group, 3-chlorophenyl group, 4-chlorophenyl group, 2,3-dichlorophenyl group, 2,4-dichlorophenyl group, 2,5-dichlorophenyl group, 2,6-dichlorophenyl group, 2,3,4-trichlorophenyl group, 2,3,5-trichlorophenyl group, 2,3,6-trichlorophenyl group, 2,3,4,5-tetrachlorophenyl group, 2,3,4,6-tetrachlorophenyl group Examples thereof include a chlorophenyl group, a pentachlorophenyl group, a 2-bromophenyl group, a 3-bromophenyl group, a 4-bromophenyl group, a 2,3-dibromophenyl group, a 2,4-dibromophenyl group, a 2,5-dibromophenyl group, a 2,6-dibromophenyl group, a 2,3,4-tribromophenyl group, a 2,3,5-tribromophenyl group, a 2,3,6-tribromophenyl group, a 2,3,4,5-tetrabromophenyl group, a 2,3,4,6-tetrabromophenyl group, and a pentabromophenyl group.

[0060] D 1 , D 2Specific examples of when is an alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, an n-pentoxy group, a neopentoxy group, an n-hexoxy group, and an n-octoxy group.

[0061] D 1 , D 2 Specific examples of when is an aryloxy group include a phenoxy group, a 2-methylphenoxy group, a 3-methylphenoxy group, a 4-methylphenoxy group, and a naphthyloxy group.

[0062] D 1 , D 2 is a disubstituted amino group, the disubstituted amino group is an amino group having two bonded substituents, specific examples of which include a dimethylamino group, a diethylamino group, a di-n-propylamino group, a diisopropylamino group, a di-n-butylamino group, a diisobutylamino group, a di-sec-butylamino group, a di-tert-butylamino group, a di-n-hexylamino group, a di-n-octylamino group, and a diphenylamino group.

[0063] R 1 ~R 6 are each independently 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 di-substituted amino group having 2 to 20 carbon atoms, or a silyl group having 1 to 20 carbon atoms, which may be the same or different, and which may further be optionally bonded to form a ring. Among these, a hydrocarbon group having 1 to 20 carbon atoms is preferred.

[0064] R 1 ~R 6When is a hydrocarbon group, the carbon number is preferably 1 to 10. Specific examples thereof 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 neopentyl group, an n-hexyl group, an n-octyl group, a phenyl group, a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, a 2,3-dimethylphenyl group, a 2,4-dimethylphenyl group, a 2,5-dimethylphenyl group, a 2,6-dimethylphenyl group, a 2,3,4-trimethylphenyl group, a 2,3,5-trimethylphenyl group, a 2,3,6-trimethylphenyl group, a 2,3,4,5-tetramethylphenyl group, a 2,3,4,6-tetramethylphenyl group, and a pentamethylphenyl group.

[0065] R 1 ~R 6 Specific examples of when is a halogen atom, a halogenated hydrocarbon group, an alkoxy group, an aryloxy group, or a disubstituted amino group include D 1 , D 2 Specific examples of when is a halogen atom, a halogenated hydrocarbon group, an alkoxy group, an aryloxy group, and a disubstituted amino group include those exemplified above.

[0066] R 1 ~R 6 Specific examples of when is a 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.

[0067] Specific examples of such compounds represented by 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, and 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(cyclopentadienyl)(3-tert-butyl-2-phenoxy)titanium dichloride, isopropylidene(methylcyclopentadienyl)(3-tert-butyl-2-phenoxy)titanium dichloride, isopropylidene(dimethylcyclopentadienyl)(3-tert-butyl-2-phenoxy)titanium dichloride isopropylidene(n-propylcyclopentadienyl)(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(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) Examples of the titanium dichloride include isopropylidene(tetramethylcyclopentadienyl)(2-phenoxy)titanium dichloride, isopropylidene(n-propylcyclopentadienyl)(2-phenoxy)titanium dichloride, isopropylidene(n-butylcyclopentadienyl)(2-phenoxy)titanium dichloride, isopropylidene(isobutylcyclopentadienyl)(2-phenoxy)titanium dichloride, and isopropylidene(phenylcyclopentadienyl)(2-phenoxy)titanium dichloride.

[0068] Other examples include compounds in which titanium in the above specific examples is replaced with zirconium or hafnium, and compounds in which isopropylidene is replaced with dimethylsilylene, diphenylsilylene, or methylene.Furthermore, other examples include compounds in which dichloride is replaced with dibromide, diiodide, dimethyl, dibenzyl, dimethoxide, or diethoxide.

[0069] The transition metal complex (α) represented by the above formula (IV) can be used in combination with various co-catalysts as a catalyst for producing the polymer (B) according to one embodiment of the present invention. The co-catalyst is a compound that interacts with the transition metal complex (α) to generate species active in polymerization with cyclic olefins and alkenyl aromatic hydrocarbons. Examples of such compounds include organoaluminum compounds (β) and / or boron compounds (γ) represented by any of the following formulae (γ1) to (γ3). However, the structure of the active species generated by using these co-catalysts is not clear.

[0070] Formula (γ1) BQ 1 Q 2 Q 3 Formula (γ2) J + (BQ 1 Q 2 Q 3 Q 4 ) - Formula (γ3) (LH) + (BQ 1 Q 2 Q 3 Q 4 ) - [In formulas (γ1) to (γ3), B represents a boron atom in a trivalent state, Q 1 ~Q 4 each 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 + represents an inorganic or organic cation, L represents a neutral Lewis base (LH) + represents a Bronsted acid.]

[0071] The organoaluminum compound (β) may be any known organoaluminum compound. Specific examples include organoaluminum compounds represented by formula (β1), cyclic aluminoxanes having a structure represented by formula (β2), and linear aluminoxanes having a structure represented by formula (β3). These may be used alone or in combination of two or more.

[0072] Equation (β1) E 1 a AlZ 3-a Formula (β2) {-Al(E 2 )-O-} b Equation (β3) E 3 {-Al(E 3 )-O-} c AlE 3 2 [In formulas (β1) to (β3), E 1 , E 2 and E 3 each independently represents a hydrocarbon group having 1 to 8 carbon atoms, and all E 1 , all E 2 and all E 3 may be the same or different, Z represents hydrogen or halogen, all Z's 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.]

[0073] Specific examples of the compound of formula (β1) include trialkylaluminums such as trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, and trihexylaluminum; 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; and dialkylaluminum hydrides such as dimethylaluminum hydride, diethylaluminum hydride, dipropylaluminum hydride, diisobutylaluminum hydride, and dihexylaluminum hydride. Among these, trialkylaluminums are preferred, and triethylaluminum or triisobutylaluminum is more preferred.

[0074] E in formula (β2) and formula (β3) 2 , E 3 Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, and a neopentyl group. Of these, a methyl group or an isobutyl group is preferred. 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.

[0075] The above-mentioned aluminoxanes can be produced by various methods. The method is not particularly limited, and may be produced according to a known method. For example, a method of bringing a solution of trialkylaluminum, such as trimethylaluminum, dissolved in a suitable organic solvent, such as benzene or an aliphatic hydrocarbon, into contact with water, or a method of bringing trialkylaluminum, such as trimethylaluminum, into contact with a metal salt containing water of crystallization, such as copper sulfate hydrate, can be exemplified.

[0076] As the boron compound (γ), any of the boron compounds represented by formula (γ1), formula (γ2) or formula (γ3) can be used.

[0077] In formula (γ1), B represents a boron atom in a trivalent state, and Q 1 ~Q 3 Q each 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. 1 ~Q 3 are each independently preferably a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a halogenated hydrocarbon group having 1 to 20 carbon atoms.

[0078] Specific examples of the boron compound represented by formula (γ1) 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, and the like, and preferably tris(pentafluorophenyl)borane.

[0079] In formula (γ2), B represents a boron atom in a trivalent state, and Q 1 ~Q 4 is Q in the above equation (γ1) 1 ~Q 3 It is the same as J + represents an inorganic or organic cation.

[0080] J + Examples of the inorganic cation in the formula (I) include a ferrocenium cation, an alkyl-substituted ferrocenium cation, and a silver cation. J + Examples of the organic cation in the formula include a triphenylmethyl cation. (BQ 1 Q 2 Q 3 Q 4 ) - Examples of the anion 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.

[0081] Specific examples of these combinations include ferrocenium tetrakis(pentafluorophenyl)borate, 1,1'-dimethylferrocenium tetrakis(pentafluorophenyl)borate, silver tetrakis(pentafluorophenyl)borate, triphenylmethyl tetrakis(pentafluorophenyl)borate, triphenylmethyl tetrakis(3,5-bistrifluoromethylphenyl)borate, and the like, with triphenylmethyl tetrakis(pentafluorophenyl)borate being preferred.

[0082] In formula (γ3), B represents boron in the trivalent state, and Q 1 ~Q 4 is Q in the above equation (γ1) 1 ~Q 3 Also, L represents a neutral Lewis base, (LH) + represents a Bronsted acid.

[0083] In formula (γ3), the Bronsted acid (LH) + Examples of the cation include trialkyl-substituted ammonium cation, N,N-dialkylanilinium cation, dialkylammonium cation, and triarylphosphonium cation. (BQ 1 Q 2 Q 3 Q4 ) - Examples of the oxidizing agent include the same as those described above.

[0084] Specific combinations of these include triethylammonium tetrakis(pentafluorophenyl)borate, tripropylammonium tetrakis(pentafluorophenyl)borate, tri(n-butyl)ammonium tetrakis(pentafluorophenyl)borate, tri(n-butyl)ammonium tetrakis(3,5-bistrifluoromethylphenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, N,N-diethylanilinium tetrakis(pentafluorophenyl)borate, and N,N-2,4,6-pentamethylanilinium tetrakis(pentafluorophenyl)borate. Examples of suitable tetrakis(pentafluorophenyl)borate include tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(3,5-bistrifluoromethylphenyl)borate, di-isopropylammonium tetrakis(pentafluorophenyl)borate, dicyclohexylammonium tetrakis(pentafluorophenyl)borate, triphenylphosphonium tetrakis(pentafluorophenyl)borate, tri(methylphenyl)phosphonium tetrakis(pentafluorophenyl)borate, and tri(dimethylphenyl)phosphonium tetrakis(pentafluorophenyl)borate. Among these, tri(n-butyl)ammonium tetrakis(pentafluorophenyl)borate or N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate is preferred.

[0085] As the co-catalyst, it is preferable to use the organoaluminum compound (β) and the compound (γ) in combination.

[0086] The transition metal complex (α) represented by formula (IV), the organoaluminum compound (β) and / or the compound (γ) can be added and used in any order during polymerization, but a reaction product obtained by previously contacting any combination of these compounds may also be used.

[0087] The molar ratio of co-catalyst / transition metal complex (α) is preferably 0.01 to 10,000, more preferably 0.5 to 2,000. When the catalyst component is used in a solution state, the concentration of the transition metal complex (α) is preferably 0.0001 to 5 mmol / L, more preferably 0.001 to 1 mmol / L. The amount of the catalyst component used is preferably 0.00001 to 1 mol%, more preferably 0.0001 to 0.1 mol%, based on the total amount of all monomers used.

[0088] The polymerization method for the polymer (B) according to one embodiment of the present invention is not particularly limited, and any method can be employed, such as a batch or continuous gas phase polymerization method, a bulk polymerization method, a solution polymerization method using a suitable solvent, or a slurry polymerization method.

[0089] When a solvent is used, various solvents can be used as long as they do not deactivate the catalyst. Examples of such solvents include hydrocarbon solvents such as benzene, toluene, pentane, hexane, heptane, and cyclohexane; and halogenated hydrocarbon solvents such as dichloromethane and ethylene dichloride.

[0090] When a solvent is used, the ethylene partial pressure in the system during polymerization is, for example, 50 to 400 kPa, preferably 50 to 300 kPa, and the hydrogen partial pressure is preferably 0 to 100 kPa. When ethylene and hydrogen are introduced into the system, it is preferable to pressurize the system with the hydrogen partial pressure and then pressurize the system with the ethylene partial pressure. After the solution of the cycloolefin represented by formula (I) is introduced into a polymerization reactor, toluene may also be added.

[0091] The polymerization temperature is preferably 50° C. or higher, more preferably 50 to 150° C., and even more preferably 50 to 100° C. A chain transfer agent such as hydrogen can also be added to adjust the molecular weight of the polymer.

[0092] <Polyimide resin (A)> The polyimide 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 resin is produced by imidization. The precursor before the polyimide resin is produced is a polyamic acid. In this specification, a "repeating structural unit" may be referred to as a "structural unit." Furthermore, a "structural unit derived from" may be simply referred to as a "unit," for example, a structural unit derived from a compound may be referred to as a compound unit.

[0093] In a preferred embodiment of the present invention, the polyimide resin (A) is a compound represented by the formula (1): [ka] [In formula (1), X represents a divalent organic group, Y represents a tetravalent organic group, and * represents a bond.] It is preferable that the polyimide resin has a structural unit represented by the following formula: Such a polyimide resin can easily reduce the CTE of the film and can easily improve the mechanical properties such as heat resistance and flex resistance.

[0094] In formula (1), X's each independently represent a divalent organic group, preferably a divalent organic group having 2 to 100 carbon atoms. Examples of divalent organic groups include divalent aromatic groups and divalent aliphatic groups. Examples of divalent aliphatic groups include divalent acyclic aliphatic groups and divalent cyclic aliphatic groups. Among these, divalent cyclic aliphatic groups and divalent aromatic groups are preferred, and divalent aromatic groups are more preferred, from the viewpoints of easily reducing the CTE of the film and easily improving the heat resistance and mechanical properties. The divalent organic group may have a hydrogen atom substituted with a halogen atom, a hydrocarbon group, an alkoxy group, or a halogenated hydrocarbon group. In such cases, the number of carbon atoms in these groups is preferably 1 to 8. In this specification, a divalent aromatic group refers to a divalent organic group having an aromatic group, and may contain an aliphatic group or other substituent as part of its structure. Furthermore, a divalent aliphatic group is a divalent organic group having an aliphatic group, and may contain other substituents as part of its structure, but does not include an aromatic group.

[0095] In one embodiment of the present invention, the polyimide resin (A) may contain multiple types of X, which may be the same or different from one another. Examples of X in formula (1) include groups (structures) represented by formulas (2) to (8), and groups in which a hydrogen atom in a group represented by formulas (5) to (8) is substituted with a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, fluoro group, chloro group, or trifluoromethyl group.

[0096] [ka] [In formula (2) and formula (3), R a and R b each 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 bmay be substituted with a halogen atom, and W is independently a single bond, -O-, -CH2-, -CH2-CH2-, -CH(CH3)-, -C(CH3)2-, -C(CF3)2-, -COO-, -OOC-, -SO2-, -S-, -CO-, or -N(R c )-, and R c represents a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a hydrogen atom or a halogen atom, n is an integer of 0 to 4, t is an integer of 0 to 4, u is an integer of 0 to 4, and * represents a bond. In formula (4), 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 number of carbon atoms in ring A - 2) or less, S1 and S2 each independently represent an integer of 0 to 20, and * represents a bond.]

[0097] Other examples of X in formula (1) include divalent acyclic aliphatic groups such as linear or branched alkylene groups, such as ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, propylene, 1,2-butanediyl, 1,3-butanediyl, 1,12-dodecanediyl, 2-methyl-1,2-propanediyl, and 2-methyl-1,3-propanediyl. Hydrogen atoms in the divalent acyclic aliphatic groups may be substituted with halogen atoms, and carbon atoms may be substituted with heteroatoms, such as oxygen and nitrogen atoms.

[0098] Among these, from the viewpoint of easily achieving high water absorption resistance, high dielectric properties, low CTE, high heat resistance, and high mechanical properties of the film, the polyimide resin (A) in the present invention preferably contains, as X in formula (1), a structure represented by formula (2) and / or a structure represented by formula (3), and more preferably contains a structure represented by formula (2).

[0099] In formula (2) and formula (3), the bond of each benzene ring or cyclohexane ring may be bonded at any of the ortho, meta or para positions, or the α, β or γ positions relative to -W-. From the viewpoint of easily reducing the CTE of the film and easily improving the water absorption resistance, heat resistance and mechanical properties, the bond can be preferably at the meta or para position, or the β or γ position, more preferably at the para or γ position. a and R b are each independently 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 alkyl groups having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 2-methylbutyl, 3-methylbutyl, 2-ethylpropyl, and n-hexyl. Examples of alkoxy groups having 1 to 6 carbon atoms include methoxy, ethoxy, propyloxy, isopropyloxy, butoxy, isobutoxy, tert-butoxy, pentyloxy, hexyloxy, and cyclohexyloxy. Examples of aryl groups having 6 to 12 carbon atoms include phenyl, tolyl, xylyl, naphthyl, and biphenyl. R a and R b The hydrogen atoms contained in may be substituted with halogen atoms, independently of one another, and examples of the halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. Among these, from the viewpoint of easily reducing the CTE of the film and easily improving the water absorption resistance, heat resistance, and dielectric properties, R a and R b are each independently preferably an alkyl group having 1 to 6 carbon atoms or a fluorinated alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms or a fluorinated alkyl group having 1 to 3 carbon atoms, and further preferably a methyl group or a trifluoromethyl group.

[0100] In formula (2) and formula (3), t and u are each independently an integer of 0 to 4, and from the viewpoint of easily reducing the CTE of the film and easily improving the heat resistance and mechanical properties, t and u are preferably an integer of 0 to 2, more preferably 0 or 1.

[0101] In formula (2) and formula (3), W is each independently a single bond, -O-, -CH2-, -CH2-CH2-, -CH(CH3)-, -C(CH3)2-, -C(CF3)2-, -COO-, -OOC-, -SO2-, -S-, -CO- or -N(R c )-, and from the viewpoint of easily reducing the CTE of the film and easily improving the water absorption resistance, heat resistance, and mechanical properties, particularly bending resistance, preferably represents a single bond, -O-, -CH2-, -C(CH3)2-, -C(CF3)2-, -COO-, -OOC-, or -CO-, more preferably represents a single bond, -O-, -CH2-, -C(CH3)2-, or -C(CF3)2-. c represents a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a hydrogen atom or a halogen atom. Examples of the monovalent hydrocarbon group having 1 to 12 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 2-methylbutyl, 3-methylbutyl, 2-ethylpropyl, n-hexyl, n-heptyl, n-octyl, tert-octyl, n-nonyl, and n-decyl groups, which may be substituted with a halogen atom. Examples of the halogen atom include the same as those mentioned above.

[0102] In formulas (2) and (3), n is an integer of 0 to 4, and from the viewpoint of easily reducing the CTE of the film and easily improving the water absorption resistance, heat resistance, and mechanical properties, n is preferably an integer of 0 to 3, more preferably 1 or 2. When n is 2 or more, multiple W, R a and t may be the same or different, and the positions of the bonds of each benzene ring relative to -W- may be the same or different.

[0103] When the polyimide 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, and R in formula (2) a , R b , t, and u are independently W, n, R in formula (3). a , R b , t and u may be the same or different.

[0104] In formula (4), ring A represents a cycloalkane having 3 to 8 carbon atoms. Examples of cycloalkanes include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and preferably cycloalkanes having 4 to 6 carbon atoms. In ring A, the bonds may or may not be adjacent to each other. For example, when ring A is cyclohexane, the two bonds may be in the α-, β-, or γ-position, preferably the β- or γ-position.

[0105] R in equation (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 Examples of the hydrocarbon group having 1 to 20 carbon atoms in formula (4) include those exemplified above, and preferably represents an alkyl group having 1 to 10 carbon atoms. In formula (4), r represents an integer of 0 or more and (the number of carbon atoms in ring A - 2) or less. r is 0 or more and preferably 4 or less. S1 and S2 in formula (4) each independently represent an integer of 0 to 20. S1 and S2 each independently are preferably 0 or more, more preferably 2 or more, and preferably 15 or less.

[0106] Specific examples of the structures represented by formulas (2) to (4) include structures represented by formulas (4') and (9) to (30), in which * represents a bond.

[0107] [ka]

[0108] In a preferred embodiment of the present invention, when X in formula (1) contains a structure represented by formula (2) and / or formula (3), the proportion of structural units represented by X in formula (1) represented by formula (2) and / or formula (3) is preferably 30 mol% or more, more preferably 50 mol% or more, even more preferably 70 mol% or more, particularly preferably 90 mol% or more, and preferably 100 mol% or less, relative to the total molar amount of structural units represented by formula (1). When the proportion of structural units represented by X in formula (1) represented by formula (2) and / or formula (3) is within the above range, the CTE of the film is likely to be reduced, and the water absorption resistance, heat resistance, dielectric properties, and mechanical properties are likely to be improved. The proportion of structural units represented by Y in formula (1) represented by formula (2) and / or formula (3) is, for example, 1 It can be measured using H-NMR, or can be calculated from the ratio of raw materials used.

[0109] In formula (1), Y's each independently represent a tetravalent organic group, preferably a tetravalent organic group having 4 to 40 carbon atoms, and more preferably a tetravalent organic group having 4 to 40 carbon atoms and a cyclic structure. Examples of the cyclic structure include an alicyclic, aromatic ring, and heterocyclic structure. The organic group may have a hydrogen atom substituted with a halogen atom, a hydrocarbon group, an alkoxy group, or a halogenated hydrocarbon group, and in such cases, the number of carbon atoms in these groups is preferably 1 to 8. The polyimide resin (A) of the present invention may contain multiple types of Y's, and the multiple types of Y's may be the same or different. Examples of Y include groups (structures) represented by formulas (31) to (38); groups in which a hydrogen atom in a group represented by formulas (34) to (38) is substituted with a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, fluoro group, chloro group, or trifluoromethyl group; and tetravalent chain hydrocarbon groups having 1 to 8 carbon atoms.

[0110] [ka] [In formulas (31) to (33), R 19 ~R26 each independently 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 may be substituted with halogen atoms, independently of one another, V 1 and V 2 are each independently a single bond, -O-, -CH2-, -CH2-CH2-, -CH(CH3)-, -C(CH3)2-, -C(CF3)2-, -COO-, -OOC-, -SO2-, -S-, -CO-, -N(R j )-, formula (a) or formula (b) [ka] (In formula (a), R 27 ~R 30 each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; Z represents -C(CH3)2- or -C(CF3)2-; i is an integer of 1 to 3; * represents a bond; R j represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom; e and d each independently represent an integer of 0 to 2; f represents an integer of 1 to 3; g and h each independently represent an integer of 0 to 4; and * represents a bond.

[0111] Among these, from the viewpoint of easily reducing the CTE of the film and easily improving the heat resistance and mechanical properties, the polyimide resin in the present invention preferably contains, as Y in formula (1), at least one structure selected from the group consisting of a structure represented by formula (31), a structure represented by formula (32), and a structure represented by formula (33), and more preferably contains a structure represented by formula (31).

[0112] In formulas (31) to (33), R 19 ~R 26are each independently 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 those exemplified above as 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 in formula (2) and formula (3), respectively. R 19 ~R 26 The hydrogen atoms contained in may be substituted with halogen atoms independently of one another, and examples of the halogen atoms include those exemplified above. Among these, from the viewpoint of easily improving the water absorption resistance, heat resistance, and dielectric properties of the film, R 19 ~R 26 are each independently preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and even more preferably a hydrogen atom.

[0113] In equation (31), V 1 and V 2 are each independently a single bond, -O-, -CH2-, -CH2-CH2-, -CH(CH3)-, -C(CH3)2-, -C(CF3)2-, -COO-, -OOC-, -SO2-, -S-, -CO-, -N(R j )-, formula (a) or formula (b), and from the viewpoint of easily reducing the CTE of the film and easily improving the water absorption resistance, heat resistance and mechanical properties, preferably represents a single bond, -O-, -CH2-, -C(CH3)2-, -C(CF3)2-, -COO-, -OOC- or -CO-, more preferably represents a single bond, -O-, -C(CH3)2- or -C(CF3)2-. j represents a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a hydrogen atom or a halogen atom. Examples of the monovalent hydrocarbon group having 1 to 12 carbon atoms include those exemplified above.

[0114] In formula (31), e and d each independently represent an integer of 0 to 2, and are preferably 0 or 1, more preferably e+d=1, from the viewpoint of easily reducing the CTE of the film and easily improving the heat resistance and mechanical properties.

[0115] In formula (32), f represents an integer of 1 to 3, and is preferably 1 or 2, more preferably 1, from the viewpoint of easily reducing the CTE of the film and easily improving the heat resistance and mechanical properties.

[0116] In formula (33), g and h each independently represent an integer of 0 to 4, and from the viewpoint of easily reducing the CTE of the film and easily improving the heat resistance and mechanical properties, g and h are preferably an integer of 0 to 2, more preferably 0 or 1, and even more preferably g+h=0 to 2.

[0117] In formula (a), R 27 ~R 30 are each independently 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 formulas (2) and (3). Among these, from the viewpoint of easily reducing the CTE of the film and easily improving the heat resistance and mechanical properties, R 27 ~R 30 are each independently more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and even more preferably a hydrogen atom.

[0118] In formula (a), Z represents -C(CH3)2- or -C(CF3)2-. When Z has such a structure, the water absorption resistance, heat resistance, dielectric properties, and mechanical properties of the film are easily improved. i represents an integer of 1 to 3, and is preferably 1 or 2 from the viewpoint of easily reducing the CTE of the film and easily improving the water absorption resistance, heat resistance, and mechanical properties. When i is 2 or more, a plurality of Z and R 27 ~R 30 may be the same as or different from each other.

[0119] Specific examples of the structures represented by formulas (31) to (33) include structures represented by formulas (39) to (51). In these formulas, * represents a bond.

[0120] [ka]

[0121] In one embodiment of the present invention, when Y in formula (1) contains at least one selected from the group consisting of structures represented by formulas (31) to (33), the proportion of structural units represented by Y in formula (1) selected from the group consisting of structures represented by formulas (31) to (33) is preferably 30 mol% or more, more preferably 50 mol% or more, even more preferably 70 mol% or more, particularly preferably 90 mol% or more, and preferably 100 mol% or less, relative to the total molar amount of structural units represented by formula (1). When the proportion of structural units represented by Y in formula (1) selected from the group consisting of structures represented by formulas (31) to (33) is within the above range, the CTE of the film is easily reduced, and the water absorption resistance, heat resistance, dielectric properties, and mechanical properties are easily improved. The proportion of structural units represented by Y in formula (1) selected from the group consisting of structures represented by formulas (31) to (33) is, for example, 1 It can be measured using H-NMR, or can be calculated from the ratio of raw materials used.

[0122] The polyimide resin (A) in the present invention may contain, in addition to the structural unit represented by formula (1), at least one selected from the group consisting of a structural unit represented by formula (52), a structural unit represented by formula (53), and a structural unit represented by formula (54).

[0123] [ka]

[0124] [In formula (52) and formula (53), Y 1 represents a tetravalent organic group, Y 2 represents a trivalent organic group, X 1 and X 2 each independently represents a divalent organic group, * represents a bond. In formula (54), G and X each independently represent a divalent organic group. * represents a bond.]

[0125] In a preferred embodiment of the present invention, in formula (52) and formula (53), Y 1 is the same as Y in formula (1), and X 1 and X 2 has the same meaning as X in formula (1). Y in formula (53) 2 is preferably a group in which one of the bonds of Y in formula (1) is replaced with a hydrogen atom. 2 Examples of the Y include a group in which one of the bonds of the groups (structures) represented by formulas (31) to (38) is replaced with a hydrogen atom; and a trivalent chain hydrocarbon group having 1 to 8 carbon atoms. In one embodiment of the present invention, the polyimide resin contains a plurality of types of Y 1 or Y 2 and multiple types of Y 1 or Y 2 may be the same as or different from each other.

[0126] In formula (54), Gs each independently represent a divalent organic group, preferably a divalent 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, more preferably a divalent organic group having 2 to 100 carbon atoms and having a cyclic structure 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. Examples of the cyclic structure include an alicyclic ring, an aromatic ring, and a heterocyclic structure. Examples of the organic group represented by G include a group represented by formulas (31) to (38) in which two non-adjacent bonds are replaced with hydrogen atoms, and a divalent chain hydrocarbon group having 6 or less carbon atoms, preferably a group represented by formulas (39) to (51) in which two non-adjacent bonds are replaced with hydrogen atoms. X in formula (54) has the same meaning as X in formula (1), and when the polyimide resin contains a structural unit represented by formula (1) and a 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 resin may contain multiple types of X or G, and the multiple types of X or G may be the same or different from one another.

[0127] In one embodiment of the present invention, the polyimide resin (A) comprises a structural unit represented by formula (1), and optionally at least one structural unit selected from the group consisting of a structural unit represented by formula (52), a structural unit represented by formula (53), and a structural unit represented by formula (54). From the viewpoint of easily reducing the CTE of the film and easily improving the water absorption resistance, heat resistance, and dielectric properties, the proportion of the structural unit represented by formula (1) in the polyimide resin (A) is preferably 80 mol% or more, more preferably 90 mol% or more, and even more preferably 95 mol% or more, based on the total molar amount of all structural units contained in the polyimide resin, for example, the structural unit represented by formula (1), and optionally at least one structural unit 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). The upper limit of the proportion of the structural unit represented by formula (1) in the polyimide resin (A) is 100 mol% or less. The above proportion can be expressed, for example, as follows: 1 The CTE can be measured using H-NMR or calculated from the ratio of the raw materials used. The polyimide resin in the present invention is preferably a polyimide resin, from the viewpoints of easily reducing the CTE of the film and easily improving the water absorption resistance, heat resistance, and dielectric properties.

[0128] In one embodiment of the present invention, the polyimide resin (A) of the present invention may contain a halogen atom, preferably a fluorine atom, which can be introduced, for example, by the above-mentioned halogen-containing substituent. When the polyimide resin (A) contains a halogen atom, preferably a fluorine atom, it is easy to improve the water absorption resistance, heat resistance, and dielectric properties, as well as the optical properties. Examples of fluorine-containing substituents suitable for incorporating fluorine atoms into the polyimide resin (A) include a fluoro group and a trifluoromethyl group.

[0129] When the polyimide resin (A) contains halogen atoms, the content of halogen atoms in the polyimide resin (A) is preferably 0.1 to 40 mass%, more preferably 1 to 35 mass%, and even more preferably 5 to 30 mass%, based on the mass of the polyimide resin. When the content of halogen atoms is equal to or greater than the above lower limit, the water absorption resistance, heat resistance, and dielectric properties of the film are likely to be improved. When the content of halogen atoms is equal to or less than the above upper limit, the CTE of the film can be reduced and synthesis is facilitated.

[0130] The imidization ratio of the polyimide resin (A) is preferably 90% or more, more preferably 93% or more, and even more preferably 95% or more, and is usually 100% or less. From the viewpoint of easily improving the dielectric properties, optical properties, and water absorption resistance of the film, it is preferable that the imidization ratio is equal to or greater than the above-mentioned lower limit. The imidization ratio indicates the ratio of the molar amount of imide bonds in the polyimide resin to twice the molar amount of structural units derived from tetracarboxylic acid compounds in the polyimide resin. When the polyimide resin (A) contains a tricarboxylic acid compound, the imidization ratio indicates the ratio of the molar amount of imide bonds in the polyimide resin to the sum of twice the molar amount of structural units derived from tetracarboxylic acid compounds in the polyimide resin and the molar amount of structural units derived from tricarboxylic acid compounds. The imidization ratio can be determined by IR, NMR, or the like.

[0131] The Tg of the polyimide resin (A) is preferably 100°C or higher, more preferably 150°C or higher, even more preferably 200°C or higher, even more preferably 300°C or higher, particularly preferably 350°C or higher, and preferably 550°C or lower. When the Tg of the polyimide resin (A) is equal to or higher than the lower limit, the heat resistance of the resulting film is easily improved and the CTE is easily reduced. When the Tg of the polyimide resin (A) is equal to or lower than the upper limit, the mechanical properties are easily improved. The Tg of the polyimide resin (A) can be determined, for example, by dynamic viscoelasticity measurement (hereinafter sometimes abbreviated as DMA measurement), and can be measured by the method described in the Examples.

[0132] The Mw of the polyimide resin (A), in terms of polystyrene, is preferably 50,000 or more, more preferably 100,000 or more, more preferably 150,000 or more, even more preferably 200,000 or more, even more preferably 250,000 or more, and particularly preferably 300,000 or more, and is preferably 1,000,000 or less, more preferably 800,000 or less, even more preferably 700,000 or less, even more preferably 500,000 or less, and particularly preferably 450,000 or less. When the Mw of the polyimide resin (A) is at or above the lower limit, the water absorption resistance, heat resistance, and mechanical properties of the resulting film are easily improved, and the CTE is easily reduced. When the Mw of the polyimide resin (A) is at or below the upper limit, moldability is easily improved. The Mw of the polyimide resin (A) can be determined, for example, by GPC measurement and converted into standard polystyrene, for example, by the method described in the Examples.

[0133] As described above, the polyimide resin (A) in the present invention includes a precursor of the polyimide resin before imidization. When the polyimide resin (A) is a polyamic acid, the polyamic acid is represented by the formula (1'): TIFF0007732807000012.tif3054 [In formula (1'), Y and X represent Y and X in formula (1), respectively.] It contains a structural unit represented by:

[0134] <Method for producing polyimide resin (A)> The method for producing the polyimide resin (A) is not particularly limited, but it can be produced, for example, 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 the polyamic acid may be carried out. In addition to the tetracarboxylic acid compound, a dicarboxylic acid compound or a tricarboxylic acid compound may also be reacted.

[0135] Examples of the tetracarboxylic acid compound used in the synthesis of the polyimide resin (A) include aromatic tetracarboxylic acid compounds such as aromatic tetracarboxylic acid dianhydrides, and aliphatic tetracarboxylic acid compounds such as aliphatic tetracarboxylic acid dianhydrides. The tetracarboxylic acid compounds may be used alone or in combination of two or more. The tetracarboxylic acid compounds may be dianhydrides or tetracarboxylic acid compound analogs such as acid chloride compounds.

[0136] Specific examples of tetracarboxylic acid compounds include pyromellitic anhydride (hereinafter sometimes abbreviated as PMDA), 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride (hereinafter sometimes abbreviated as BPADA), 1,4,5,8-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride (hereinafter sometimes abbreviated as BPDA), 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride (hereinafter sometimes abbreviated as 6FDA), 4,4'-oxydiphthalic anhydride (hereinafter sometimes abbreviated as ODPA), and (may contain 2,2',3,3'-, 2,3,3',4'- or 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,3',3,4'-diphenylethertetracarboxylic dianhydride, bis(2,3-dicarboxyphenyl)ether dianhydride, 3,3",4,4"-, 2,3,3",4"- or 2,2",3,3"-p-terphenyltetracarboxylic dianhydride, 2,2-bis(2,3- or 3,4- 1,1-bis(2,3- or 3,4-dicarboxyphenyl)ethane dianhydride, 1,2,7,8-, 1,2,6,7- or 1,2,9,10-phenanthrenetetracarboxylic acid dianhydride, 2,2-bis(3,4-dicarboxyphenyl)tetrafluoropropane dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride (hereinafter sometimes abbreviated as HPMDA), 2,3,5,6-cyclohexanetetracarboxylic acid dianhydride Anhydride, 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-phenylenebis(trimellitate anhydride), 3,3',4,4'-Diphenylsulfonetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 2,6- or 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7-(or 1,4,5,8-)tetrachloronaphthalene-1,4,5,8-(or 2,3,6, Examples of suitable tetracarboxylic acid compounds include 2,3,8,9-, 3,4,9,10-, 4,5,10,11-, or 5,6,11,12-perylenetetracarboxylic acid dianhydride, pyrazine-2,3,5,6-tetracarboxylic acid dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic acid dianhydride, thiophene-2,3,4,5-tetracarboxylic acid dianhydride, and bis(2,3- or 3,4-dicarboxyphenyl)sulfone dianhydride. Among these, PMDA, BPDA, 6FDA, BPADA, ODPA, HPMDA, CBDA, and p-phenylenebis(trimellitate anhydride) are preferred, as they can easily reduce the CTE of the film and improve water absorption resistance, heat resistance, dielectric properties, and mechanical properties. These tetracarboxylic acid compounds can be used alone or in combination.

[0137] Examples of diamine compounds used in the synthesis of the polyimide resin (A) include aliphatic diamines, aromatic diamines, and mixtures thereof. In this embodiment, "aromatic diamine" refers to a diamine having an aromatic ring, which may contain an aliphatic group or other substituents as part of its structure. This aromatic ring may be a single ring or a condensed ring, and examples include a benzene ring, a naphthalene ring, an anthracene ring, and a fluorene ring, but are not limited to these. Among these, a benzene ring is preferred. Furthermore, "aliphatic diamine" refers to a diamine having an aliphatic group, which may contain other substituents as part of its structure, but does not have an aromatic ring.

[0138] 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'-diaminodiphenyl (hereinafter sometimes referred to as TFMB), 4,4'-diaminodiphenyl ether, 1,3-bis(3-aminophenoxy)benzene (hereinafter sometimes abbreviated 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, nophenoxy)]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'-methylene-2,6-diethylaniline, 4,4'-methylenedianiline, 3,3'-methylenedianiline, 4,4'-diaminodiphenylpropane, 3,3'-diaminodiphenylpropane, 4,4'-diaminodiphenylethane, 3,3'-diaminodiphenylethane, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,3-diaminodiphenylether, 3,4'-diaminodiphenylether, benzidine, 3,3'-Diaminobiphenyl, 3,3'-dimethoxybenzidine, 4,4"-diamino-p-terphenyl, 3,3"-diamino-p-terphenyl, m-phenylenediamine, p-phenylenediamine (sometimes abbreviated as p-PDA), resorcinol bis(3-aminophenyl) ether, 4,4'-[1,4-phenylenebis(1-methylethylidene)]bisaniline, 4,4'-[1,3-phenylenebis(1-methylethylidene)]bisaniline, bis(p-aminocyclohexyl)methane, bis(p-β-amino-tert-butyl phenyl) 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-tert-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)benzene ethyl)bicyclohexane, 4,4'-diaminodicyclohexylmethane, 4,4"-diamino-p-terphenyl, bis(4-aminophenyl)terephthalate, 1,4-bis(4-aminophenoxy)-2,5-di-tert-butylbenzene, 4,4'-(1,3-phenylenediisopropylidene)bisaniline, 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)dianiline, 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 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, norbornanediamine, 2'-methoxy-4,4'-diaminobenzanilide, 4,Examples of the aromatic hydrocarbon radicals include 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, and 2,5-diaminopyridine. Among these, from the viewpoints of easily reducing the CTE of the film and easily improving the water absorption resistance, heat resistance, dielectric properties, and mechanical properties, 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"-diamino-p-terphenyl, bis(4-aminophenyl)terephthalate, 1,4-bis(4-aminophenoxy) Preferred examples include 1,3-di-tert-butylbenzene, 1,3-APB, 1,4-APB, resorcinol-bis(3-aminophenyl)ether, 4,4'-(1,3-phenylenediisopropylidene)bisaniline, 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, and 4,4'-(hexafluoropropylidene)dianiline. The diamine compounds can be used alone or in combination.

[0139] The polyimide resin (A) may be a compound obtained by further reacting, in addition to the tetracarboxylic acid compound used in the synthesis of the resin, other tetracarboxylic acids, dicarboxylic acids, tricarboxylic acids, and anhydrides and derivatives thereof, within the range that does not impair the various physical properties of the film.

[0140] Other tetracarboxylic acids include water adducts of the anhydrides of the above tetracarboxylic acid compounds.

[0141] Examples of dicarboxylic acid compounds include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and their related acid chloride compounds, acid anhydrides, etc., which may be used alone or in combination of two or more. Specific examples include dicarboxylic acid compounds of terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 3,3'-biphenyldicarboxylic acid, and chain hydrocarbons having 8 or less carbon atoms, as well as compounds in which two benzoic acids are linked by a single bond, -O-, -CH2-, -C(CH3)2-, -C(CF3)2-, -SO2-, or a phenylene group, and acid chloride compounds thereof.

[0142] Examples of tricarboxylic acid compounds include aromatic tricarboxylic acids, aliphatic tricarboxylic acids, and their related acid chloride compounds, acid anhydrides, etc., which may be used alone or in combination of two or more. Specific examples include 1,2,4-benzenetricarboxylic acid anhydride; 2,3,6-naphthalenetricarboxylic acid-2,3-anhydride; and compounds in which phthalic anhydride and benzoic acid are linked via a single bond, -O-, -CH2-, -C(CH3)2-, -C(CF3)2-, -SO2-, or a phenylene group.

[0143] In producing the polyimide resin (A), the amounts of the diamine compound, tetracarboxylic acid compound, dicarboxylic acid compound and tricarboxylic acid compound used can be appropriately selected depending on the desired ratio of each structural unit in the resin. In a preferred embodiment of the present invention, the amount of the diamine compound used is preferably 0.94 mol or more, more preferably 0.96 mol or more, even more preferably 0.98 mol or more, particularly preferably 0.99 mol or more, and is preferably 1.20 mol or less, more preferably 1.10 mol or less, even more preferably 1.05 mol or less, particularly preferably 1.02 mol or less, relative to 1 mol of the tetracarboxylic acid compound. When the amount of the diamine compound used relative to the tetracarboxylic acid compound is within the above range, the CTE of the obtained film is likely to be reduced, and the water absorption resistance, heat resistance, dielectric properties, mechanical properties, and optical properties are likely to be improved.

[0144] The reaction temperature between the diamine compound and the tetracarboxylic acid compound is not particularly limited and may be, for example, 5 to 200°C, and the reaction time is also not particularly limited and 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°C, more preferably 10 to 40°C, and the reaction time is preferably 3 to 24 hours. Such a reaction temperature and reaction time make it easy to reduce the CTE of the obtained film and to improve the water absorption resistance, heat resistance, dielectric properties, mechanical properties, and optical properties.

[0145] The reaction between the diamine compound and 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 alcoholic 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; phenolic 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; acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, methyl isobutyl ether, and the like. Examples of suitable solvents include ketone solvents such as chiral 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 solvents such as N-methylpyrrolidone (hereinafter sometimes abbreviated as NMP); and combinations thereof. Among these, phenolic solvents, amide solvents, and pyrrolidone solvents are preferred from the viewpoint of solubility.

[0146] The reaction of the diamine compound with the tetracarboxylic acid compound may be carried out, as necessary, in an inert atmosphere such as a nitrogen atmosphere or an argon atmosphere or under reduced pressure. For example, it is preferable to carry out the reaction in an inert atmosphere such as a nitrogen atmosphere or an argon atmosphere in a strictly controlled dehydrated solvent while stirring.

[0147] In the imidization step, imidization may be performed using an imidization catalyst, by heating, or a combination of these. Examples of the imidization catalyst used in the imidization step include aliphatic amines such as tripropylamine, dibutylpropylamine, and ethyldibutylamine; alicyclic amines (monocyclic) such as N-ethylpiperidine, N-propylpiperidine, N-butylpyrrolidine, N-butylpiperidine, and N-propylhexahydroazepine; azabicyclo[2.2.1]heptane, azabicyclo[3.2.1]octane, azabicyclo[2.2.2]octane, and azabicyclo[2.2.1]heptane. [3.2.2] Examples of suitable imidation catalysts include alicyclic (polycyclic) amines 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. Furthermore, in order to facilitate the imidization reaction, it is preferable to use an acid anhydride together with the imidization catalyst. Examples of suitable acid anhydrides include conventional acid anhydrides used in imidization reactions, such as 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 carried out in a solvent in which the polyamic acid is dissolved, or may be carried out in a film form, as described below.

[0148] In one embodiment of the present invention, when imidization is carried out, the reaction temperature is usually 20 to 250° C., and the reaction time is preferably 30 minutes to 24 hours, more preferably 1 to 12 hours.

[0149] The polyimide resin (A) may be isolated by separation and purification using a conventional method, for example, a separation means such as filtration, concentration, extraction, crystallization, recrystallization, column chromatography, or a separation means combining these. In a preferred embodiment, the resin can be isolated by adding a large amount of alcohol such as methanol to a reaction solution containing the resin to precipitate the resin, followed by concentration, filtration, drying, etc. <Film> The film of the present invention comprises a polyimide resin (A) and a particulate polymer (B), and has a brightness of 37 or less on both sides of the film when the haze is 75% or less, and a brightness of 80 or less on both sides of the film when the haze is greater than 75%, thus exhibiting excellent water absorption resistance. The film of the present invention has excellent water absorption resistance, which can enhance the dielectric properties of the film. Furthermore, the film of the present invention also has excellent surface smoothness. Therefore, the film of the present invention can possess excellent water absorption resistance, dielectric properties, and surface smoothness all at once.

[0150] 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. HSP is the Hansen solubility parameter (δ), which is defined by three parameters (δD, δP, δH) and is expressed by the formula (X): δ 2 =(δD) 2 +(δP) 2 +(δH) 2 (X) [In formula (X), δD represents the London dispersion force term, δP represents the molecular polarization term (dipole-dipole force term), and δH represents the hydrogen bond term] Details regarding HSP are described in "Properties of Polymers" (author: DW Vankrevelen, publisher: Elsevier Scientific Publishing Company, 5th edition, 1989). The Hansen solubility parameters δD, δP, and δH can be calculated using HSPiP (Hansen Solubility Parameters in Practice), a program developed by the group of Dr. Hansen, who proposed the Hansen solubility parameters. Version 4.1.07, for example, can be used. The Hansen Solubility Sphere Method is described in detail below. The target component is dissolved in a solvent with a known HSP value, and the solubility of the component in that specific solvent is evaluated. Solubility is evaluated by visually determining whether each target component dissolves in the solvent. This is performed for multiple solvents. It is preferable to use solvents with widely varying δt values; more specifically, preferably 10 or more, more preferably 15 or more, and even more preferably 18 or more. Next, the solubility evaluation results obtained are input into HSPiP, and the central coordinates (δd, δp, δh) of the obtained Hansen sphere are used as the HSP of the target composition. In addition to the above-mentioned methods, the HSP may be determined from, for example, values ​​in the HSPiP database or literature values, or from the structural formula using HSPiP. In this specification, the value of the Hansen solubility parameter is referred to as the HSP value, and the HSP value represents the value at 25°C. The HSP value of the polyimide resin (A), the HSP value of the polymer (B), and the HSP value of the solvent may each be determined by any of the above-mentioned methods, for example, by the method described in the Examples.

[0151] The distance between the Hansen Solubility Parameters (hereinafter sometimes abbreviated as HSP) of two substances is called the HSP distance. The HSP distance (Ra) is an index that shows the affinity between two substances, and the smaller the value, the higher the affinity between the two substances. Conversely, the larger the Ra value, the lower the affinity between the two substances, i.e., the more difficult it is for them to be compatible. The distance between HSP values ​​is calculated by dividing the Hansen solubility parameters δA and δB of two substances A and B by δA=(δDA, δPA, δHA) δB=(δDB, δPB, δHB) Assuming that, the distance between HSPs (Ra) is calculated by the formula (Y): Ra = [4 × (δDA − δDB) 2 +(δPA‐δPB) 2 +(δHA‐δHB) 2 ] 0.5 (Y) It can be calculated as follows. In this specification, the HSP value and the distance between HSP values ​​are as defined above, and can be determined according to the method described above.

[0152] 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 flexural resistance, as well as dielectric properties, and can have a reduced CTE, even if the distance between the HSP values ​​of the polyimide resin (A) and the polymer (B) is relatively large. Therefore, in the film of the present invention, the distance between the HSP values ​​of the polyimide resin (A) and the polymer (B) is preferably 6.0 or more, more preferably 7.0 or more, and even more preferably 8.0 or more. Furthermore, 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, from the viewpoint of the affinity between the resin and the polymer.

[0153] 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, even more preferably 80% by mass or more, particularly preferably 90% by mass or more, and preferably 100% by mass or less, based on the mass of the film. When the total mass of the polyimide resin (A) and the particulate polymer (B) contained in the film is equal to or more than the above lower limit, the water absorption resistance, dielectric properties, and surface smoothness of the film are likely to be improved.

[0154] 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, with the polyimide resin (A) forming the sea and the particulate polymer (B) forming the islands. Such a composite film is likely to have improved mechanical properties such as water absorption resistance, heat resistance, and flex resistance, as well as dielectric properties, and is likely to have a reduced CTE. By setting the distance between the HSP values ​​of the polyimide resin (A) and the polymer (B) to be equal to or greater than the above-mentioned lower limit, the particulate polymer (B) can be easily dispersed uniformly in the film, thereby producing a film with excellent water absorption resistance.

[0155] In one embodiment of the present invention, the film of the present invention may have a low CTE. The CTE of the film can be appropriately designed depending on the application. When a CCL is produced by laminating it with copper foil, it is preferable to adjust the CTE of the film to around 20 ppm / K from the viewpoint of preventing peeling of the laminated film. The CTE of the film can be adjusted by the CTE and mixing amount of the polyimide resin (A) and particulate polymer (B) to be mixed. From the viewpoint of reducing the CTE, it is preferable to mix a particulate polymer (B) with a high Tg. The CTE can be measured by TMA, for example, by the method described in the Examples.

[0156] The water absorption resistance of the film of the present invention can be evaluated by its water absorption rate. In one embodiment of the present invention, the water absorption rate of the film of the present invention is preferably 1% or less, more preferably 0.8% or less, even more preferably 0.6% or less, even more preferably 0.5% or less, and particularly preferably 0.3% or less. When the water absorption rate of the film is below the above upper limit, it can have excellent water absorption resistance. Therefore, when the film of the present invention is used in the resin layer of a CCL, when the water absorption rate of the film is below the above upper limit, it is easy to improve the dielectric properties and suppress the dielectric loss and transmission loss. Furthermore, the water absorption rate of the film of the present invention may usually be 0.01% or more. The water absorption rate 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 exposure to water vapor, and can be measured, for example, by the method described in the Examples.

[0157] In one embodiment of the present invention, the film of the present invention can have excellent surface smoothness. The surface smoothness of a film can be evaluated by the standard deviation of the average thickness measured in 10 measurement regions obtained by dividing a linear 1 mm area of ​​the film surface into 10 equal 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, even more preferably 1.70 or less, even more preferably 1.50 or less, particularly preferably 1.0 or less, especially more preferably 0.8 or less, and especially more preferably 0.5 or less. When the standard deviation of the average thickness is below the above upper limit, the surface smoothness of the film can be further improved. Therefore, when the film is used as a resin layer for a CCL, for example, high processing accuracy can be easily achieved when increasing the wiring density and miniaturization, and peeling between the film and copper foil can be easily suppressed. 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 even more preferably 0.2 or more. If the standard deviation of the average thickness is equal to or greater than the lower limit, adhesion is likely to be improved due to the anchor effect when the film is attached to copper foil with an adhesive or the like. The standard deviation of the average thickness of the film can be determined by arbitrarily selecting a continuous linear 1 mm area on the film surface, dividing the area into 10 equal parts to set 10 measurement areas, measuring the average thickness in each of the 10 measurement areas using a contact or non-contact film thickness meter, step gauge, surface profiler, or the like, and calculating the standard deviation of the average thickness in each of the obtained measurement areas. For example, it can be determined by the method described in the Examples. The average thickness in each measurement area may be an average calculated from multiple thicknesses measured at any point in that measurement area.

[0158] The film of the present invention may contain additives as needed. Examples of additives include antioxidants, flame retardants, crosslinking agents, surfactants, compatibilizers, imidization catalysts, weathering agents, lubricants, antiblocking agents, antistatic agents, antifogging agents, anti-dripping agents, pigments, and fillers. The additives may be used alone or in combination.

[0159] In one embodiment of the present invention, the film of the present invention exhibits high water absorption resistance, low thermal conductivity variation, low CTE, high heat resistance, and excellent mechanical properties even without the inclusion of a compatibilizer, because the particulate polymer (B) exhibits high particle dispersibility. 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, even more preferably 0.1 parts by mass or less, even more preferably less than 0.1 parts by mass, particularly preferably 0.05 parts by mass or less, particularly preferably 0.01 parts by mass or less, especially more preferably 0.001 parts by mass or less, and most preferably 0 parts by mass, per 100 parts by mass of the polyimide resin (A). Furthermore, for example, when the polyimide resin (A) is a polyimide resin precursor such as polyamic acid and thermal imidization is required during film production, the content of the compatibilizer is preferably less than 0.1 parts by mass within the above range, from the viewpoint of preventing inhibition of imidization by the compatibilizer and deterioration of the film properties due to deterioration of the compatibilizer due to heating. The content of the compatibilizer may be based on 100 parts by mass of the total of the polyimide resin (A) and the particulate polymer (B) instead of 100 parts by mass of the polyimide resin (A).

[0160] The thickness of the film of the present invention can be appropriately selected depending on the application, and is preferably 5 μm or more, more preferably 10 μm or more, even more preferably 20 μm or more, and preferably 500 μm or less, more preferably 300 μm or less, even more preferably 100 μm or less, and particularly preferably 80 μm or less. The film thickness can be measured using a thickness meter or the like, for example, by the method described in the Examples. When the film of the present invention is a multilayer film, the above thickness represents the average thickness of the single layer portion.

[0161] The film of the present invention may be a single-layer film or a multilayer film containing at least one layer made of the film of the present invention. The multilayer film may contain other layers (or other films). In such cases, all layers are included in the film of the present invention. Examples of other layers include functional layers. Examples of functional layers include a primer layer, a gas barrier layer, an adhesive layer, and a protective layer. The functional layers can be used alone or in combination of two or more.

[0162] The film of the present invention may be subjected to a surface treatment such as corona discharge treatment, flame treatment, plasma treatment, or ozone treatment by a method generally employed in industry.

[0163] The film according to one embodiment of the present invention has excellent water absorption resistance and dielectric properties. Therefore, it can be suitably used as a substrate material compatible with high-frequency band printed circuit boards and antenna substrates. For example, CCL has a structure in which copper foil is laminated on both surfaces of a resin layer via an adhesive. When the film of the present invention is used as the resin layer, it has excellent water absorption resistance and small dielectric loss, thereby reducing transmission loss. When the film of the present invention is used as the resin layer, it has high surface smoothness and a reduced CTE, thereby effectively preventing peeling between the copper foil and the resin layer compared to conventional films. Furthermore, it has excellent mechanical properties, particularly bending resistance, making it resistant to plastic deformation and less prone to curling, and can also be used as a flexible substrate material. The film of the present invention can also be suitably used for industrial materials such as automobile parts and electric and electronic parts; and optical materials such as lenses, prisms, optical fibers, and recording media.

[0164] [Film manufacturing method] The method for producing the film of the present invention is not particularly limited, but may be, for example, the following steps: (a) a composition preparation step of preparing a composition containing a polyimide-based 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) A film formation process in which the applied liquid (coating) is dried to form a film. The polyimide resin (A) can be produced by a method comprising the steps of: When the polyimide resin (A) is thermally imidized, a step of completing the imidization reaction may be included.

[0165] <Composition preparation process> The composition contains a polyimide resin (A), a particulate polymer (B), a solvent, and, if necessary, the additives. The composition may be prepared or produced, for example, by mixing the polyimide resin (A), the particulate polymer (B), a solvent, and optionally the additives. However, it is preferable to produce the composition by the following method, because it improves the dispersibility of the particulate polymer (B) in the resulting film, and it is easy to adjust the brightness to 37 or less on both sides of the film when the haze is 75% or less, and it is easy to adjust the brightness to 80 or less on both sides of the film when the haze is more than 75%.

[0166] In a preferred embodiment of the present invention, the method for producing the composition of the present invention comprises the steps of: Step (1) of dissolving the polymer (B) in a first solvent to obtain a polymer (B) solution; a step (2) of contacting the polymer (B) solution with a second solvent and then distilling off the first solvent to obtain a dispersion containing the particulate polymer (B) (hereinafter, sometimes referred to as a particulate polymer (B) dispersion); and a step (3) of adding a polyimide resin (A) to the dispersion of the particulate polymer (B); This production method can suppress the aggregation of particles of polymer (B), making it easy to reduce the particle size and improve dispersibility. Therefore, it is easy to obtain a film with high water absorption resistance, surface smoothness, and excellent mechanical properties. Furthermore, this production method also makes it easy to reduce the brightness of the resulting film.

[0167] Step (1) is a step of dissolving polymer (B) in a first solvent to obtain a polymer (B) solution. The form of polymer (B) dissolved in the first solvent is not particularly limited. The first solvent is not particularly limited as long as it can dissolve polymer (B), and examples include hydrocarbon solvents such as benzene, toluene, pentane, hexane, heptane, cyclohexane, and xylene; and halogenated hydrocarbon solvents such as dichloromethane and ethylene dichloride. Among these, hydrocarbon solvents are preferred. When the first solvent contains a hydrocarbon solvent, the solubility of polymer (B) with the first solvent is increased, making it easier to reduce the particle size of the particulate polymer (B) and improve its dispersibility. 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 is easily obtained (hereinafter, the description of effects after "as a result" may be omitted). The first solvent can be used alone or in combination of two or more types.

[0168] As described above, the first solvent is a solvent in which the polymer (B) dissolves. Herein, the evaluation of "solubility" or "insolubility" can be performed according to the method described in "Evaluation of Solubility" in the Examples.

[0169] In one embodiment of the present invention, the distance between the HSP values ​​of the first solvent and the polymer (B) is preferably 4.0 or less, more preferably 3.0 or less, and even more preferably 2.5 or less. When the distance between the HSP values ​​is equal to or less than the upper limit, the solubility of the first solvent and the polymer (B) is increased, making it easier to reduce the particle size of the particulate polymer (B) and improve its dispersibility. The lower limit of the distance between the HSP values ​​is usually greater than 0.

[0170] In one embodiment of the present invention, the distance between the HSP values ​​of the first solvent and the polymer (B) is preferably smaller than the interaction radius of the polymer (B). This relationship facilitates the dissolution of the polymer (B) in the first solvent, thereby facilitating the reduction of the particle size of the particulate polymer (B) and the improvement of its dispersibility. Furthermore, in this specification, the interaction radius refers to the radius of the Hansen solubility sphere, i.e., the radius of the Hansen solubility sphere, which is the sphere that tends to converge at similar locations, i.e., close coordinates, when the Hansen solubility parameters of multiple solvents capable of dissolving a specific polymer are plotted in three-dimensional HSP space. A solute with a large interaction radius is easily soluble in many solvents, while a solute with a small interaction radius is easily soluble in a few solvents and poorly soluble in many solvents. For a specific unknown polymer, a solubility test is performed to determine whether various solvents are good or poor solvents, and the results are input into HSPiP to calculate the interaction radius of the polymer. Hereinafter, in this specification, the "interaction radius" is as defined above and can be determined according to the above method.

[0171] In one embodiment of the present invention, the first solvent is preferably a solvent in which the polyimide resin (A) does not dissolve, which makes it easy to reduce the particle size of the particulate polymer (B) and improve its dispersibility.

[0172] In one embodiment of the present invention, the distance between the HSP values ​​of the first solvent and the polyimide resin (A) is preferably 5.0 or more, more preferably 6.0 or more, even more preferably 7.0 or more, even more preferably 8.0 or more, and particularly preferably 9.0 or more. When the distance between the HSP values ​​is equal to or greater than the above-mentioned lower limit, the polyimide resin (A) is less likely to dissolve in the first solvent, which makes it easier to suppress the formation of aggregates of the particulate polymer (B). Furthermore, the particle size is easily reduced, which makes it easier to improve dispersibility. Furthermore, the mechanical properties of the resulting film, such as surface smoothness, particle dispersibility, heat resistance, water absorption resistance, and flex resistance, are easily improved, and the CTE is easily reduced. The upper limit of the distance between the HSP values ​​of the first solvent and the polyimide resin (A) is preferably 30.0 or less, more preferably 27 or less, even more preferably 25 or less, even more preferably 23 or less, and particularly preferably 21 or less. When the distance between the HSP values ​​of the first solvent and the polyimide resin (A) is equal to or less than the upper limit, aggregation of the particulate polymer (B) is easily suppressed, which makes it easier to improve the dispersibility of the particles and the particle dispersibility of the resulting film.

[0173] In one embodiment of the present invention, the distance between the HSP values ​​of the first solvent and the polyimide resin (A) is preferably greater than the interaction radius of the polyimide resin (A). This relationship makes it difficult for the polyimide resin (A) to dissolve in the first solvent, which helps to suppress the formation of aggregates of the particulate polymer (B). Furthermore, the particle size is easily reduced, which helps to improve dispersibility. Furthermore, the mechanical properties of the resulting film, such as surface smoothness, particle dispersibility, heat resistance, water absorption resistance, and flex resistance, are easily improved, and the CTE is easily reduced.

[0174] In one embodiment of the present invention, the solubility of polymer (B) in the first solvent is preferably greater than the solubility of polymer (B) in the second solvent. This relationship facilitates the production of particulate polymer (B) with a small particle size and good dispersibility. The solubility of polymer (B) in a solvent can be measured by the following method: 1,000 mg of polymer (B) and 3 mL of solvent are added to a sample bottle and stirred at room temperature for 2 hours. The solid and liquid phases are then separated by filtration, and the solid phase is dried under reduced pressure at 80°C for 2 hours. The mass, X (mg), is measured, and the solubility, Y (mg / mL), can be calculated using the following formula: Y=(1,000-X) / 3 For example, when the polymer (B) corresponds to the definition in this specification that it is "soluble" in the first solvent and "insoluble" in the second solvent, the solubility in the first solvent is obviously greater, and therefore it is not necessary to measure the solubility.

[0175] The content of polymer (B) in the polymer (B) solution is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, still more preferably 0.5% by mass or more, and preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less. When the content of polymer (B) in the solution is equal to or greater than the above-mentioned lower limit, the composition can be easily prepared. When the content of polymer (B) in the solution is equal to or less than the above-mentioned upper limit, a dispersion and a film having a small particle size and high dispersibility can be easily obtained.

[0176] The method for dissolving the polymer (B) in the first solvent is not particularly limited, and for example, the first solvent may be added to the polymer (B), the polymer (B) may be added to the first solvent, or both may be used. Furthermore, depending on the solubility of the first solvent in the polymer (B), dissolution may be achieved by heating or the like.

[0177] Step (2) is a step of contacting the polymer (B) solution with a second solvent, and then distilling off the first solvent to obtain a particulate polymer (B) dispersion.

[0178] The second solvent is not particularly limited as long as it can produce a particulate polymer (B) upon contact with the polymer (B) solution. Examples include amide solvents such as DMAc and DMF; lactone solvents such as GBL and γ-valerolactone; sulfur-containing solvents such as dimethyl sulfone, dimethyl sulfoxide, and sulfolane; carbonate solvents such as ethylene carbonate and propylene carbonate; pyrrolidone solvents such as N-methylpyrrolidone; and combinations thereof. Among these, at least one solvent selected from the group consisting of amide solvents, lactone solvents, and pyrrolidone solvents is preferred, as they are more likely to suppress aggregation of the particulate polymer (B) and have high particle dispersibility, resulting in a film with low brightness, high water absorption resistance, a smooth surface, a low CTE, high heat resistance, and high mechanical properties. These solvents can be used alone or in combination. The particulate polymer (B) dispersion may also contain water, alcohol solvents, ketone solvents, acyclic ester solvents, ether solvents, etc.

[0179] In one embodiment of the present invention, the distance between the HSP values ​​of the second solvent and the polymer (B) is preferably 8.5 or more, more preferably 9.0 or more, even more preferably 10.0 or more, and even more preferably 11.0 or more. When the distance between the HSP values ​​is equal to or greater than the above-mentioned lower limit, aggregation of polymer (B) particles is easily suppressed, and the particle size is easily reduced, thereby improving particle dispersibility. As a result, the brightness of the resulting film is easily reduced, and mechanical properties such as water absorption resistance, particle dispersibility, surface smoothness, heat resistance, and flex resistance are easily improved. Furthermore, the upper limit of the distance between the HSP values ​​of the second solvent and the polymer (B) is preferably 30.0 or less, more preferably 25.0 or less, and even more preferably 20.0 or less. When the distance between the HSP values ​​of the second solvent and the polymer (B) is equal to or less than the above-mentioned upper limit, aggregation of the particulate polymer (B) is easily suppressed, thereby improving particle dispersibility. Furthermore, the brightness of the resulting film is easily reduced, and particle dispersibility is easily improved.

[0180] In one embodiment of the present invention, the distance between the HSP values ​​of the second solvent and the polymer (B) is preferably greater than the interaction radius of the polymer (B). In this relationship, the polymer (B) is less likely to dissolve in the second solvent, making it easier to reduce the particle size of the particulate polymer (B) in the particulate polymer (B) dispersion and to improve dispersibility.

[0181] In one embodiment of the present invention, the second solvent is preferably a solvent in which the polymer (B) does not dissolve. Such a solvent makes it easy to suppress aggregation of the particulate polymer (B), making it easy to reduce the particle size and improve the dispersibility of the particles.

[0182] In one embodiment of the present invention, the second solvent is preferably a solvent in which the polyimide resin (A) dissolves. Such a solvent facilitates dispersion of the particulate polymer (B) with small particle diameters in the resulting composition and film. Furthermore, the film readily forms a sea-island structure.

[0183] In one embodiment of the present invention, the HSP value distance between the second solvent and the polyimide resin (A) is preferably 10.0 or less, more preferably 9.5 or less, even more preferably 9.0 or less, particularly preferably 8.5 or less, and is preferably 0.01 or more, more preferably 0.1 or more. When the HSP value distance is equal to or less than the above upper limit, the affinity between the second solvent and the polyimide resin (A) can be improved, and therefore the particulate polymer (B) is dispersed with a small particle size in the obtained composition and film, and particle dispersibility is easily improved.

[0184] In one embodiment of the present invention, the distance between the HSP values ​​of the second solvent and the polyimide resin (A) is preferably smaller than the interaction radius of the polyimide resin (A). With this relationship, the polyimide resin (A) is easily dissolved in the second solvent, and the particulate polymer (B) is easily dispersed in the resulting composition with a small particle size, which facilitates particle dispersibility.

[0185] The method for contacting the polymer (B) solution with the second solvent is not particularly limited, and examples thereof include a method of mixing the polymer (B) solution with the second solvent. Specific examples include a method of adding the polymer (B) solution to the second solvent, and a method of adding the second solvent to the polymer (B) solution. By contacting in this manner, a particulate polymer (B) having a small particle size can be precipitated or dispersed in a mixture of the second solvent and the first solvent. Note that, within a range that does not cause aggregation of the particulate polymer (B), a small amount of polyimide resin (A) or other additives may be added at any timing during step (2).

[0186] The amount of the polymer (B) solution to be contacted with the second solvent is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.3 parts by mass or more, particularly preferably 0.7 parts by mass or more, and is preferably 100 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 3 parts by mass or less, particularly preferably 1.5 parts by mass or less, per part by mass of the second solvent. When the amount of the polymer (B) solution to be contacted with the second solvent is within the above range, aggregation of the particulate polymer (B) is easily suppressed, making it easy to reduce the particle size and improve the dispersibility of the particles.

[0187] In step (2), the polymer (B) solution is contacted with the second solvent, and then the first solvent is distilled off. By distilling off the first solvent, the dispersion stability of the particulate polymer (B) can be improved. Furthermore, by distilling off the first solvent, the polymer (B) may be further precipitated. The first solvent only needs to be at least partially distilled off or removed, and the first solvent may remain in the dispersion containing the particulate polymer (B). From the viewpoints of easily suppressing aggregation of the polymer (B) and facilitating the preparation of the dispersion, it is preferable that the first solvent partially remains or is partially contained in the dispersion of the particulate polymer (B).

[0188] In step (2), the method for distilling off the first solvent is not particularly limited, and an example thereof is a method of distilling off under reduced pressure using an evaporator or the like. The pressure and temperature during distillation can be appropriately selected depending on the properties of the first solvent and the second solvent, such as their boiling points. In this production method, the first solvent is distilled off from a mixture of the first solvent and the second solvent, and therefore the boiling point of the first solvent is usually lower than that of the second solvent.

[0189] The content of the first solvent contained in the particulate polymer (B) dispersion obtained after distillation of the first solvent is preferably 120 parts by mass or less, more preferably 100 parts by mass or less, even more preferably 60 parts by mass or less, even more preferably 45 parts by mass or less, particularly preferably 40 parts by mass or less, particularly more preferably 35 parts by mass or less, particularly more preferably 30 parts by mass or less, particularly even more preferably less than 30 parts by mass, and most preferably 25 parts by mass or less, and preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more, relative to 100 parts by mass of the second solvent. When the content of the first solvent is below the above-mentioned upper limit, aggregation of the particulate polymer (B) is easily suppressed, making it easy to reduce the particle size and improve the particle dispersibility. 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. Furthermore, when the content of the first solvent is above the above-mentioned lower limit, it is easy to prepare the dispersion. The content of the first solvent in the particulate polymer (B) dispersion can be measured by gas chromatography, and can be calculated, for example, by the method described in the Examples.

[0190] 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, even more preferably 90% by mass or more, particularly preferably 95% by mass or more, relative to the mass of the dispersion, and is preferably 99.99% by mass or less, more preferably 99.9% by mass or less, even more preferably 99% by mass or less, particularly preferably 95% by mass or less. When the solvent content is within the above range, aggregation of the particulate polymer (B) is easily suppressed, making it easy to reduce the particle size and improve the dispersibility of the particles. As a result, the water absorption resistance, particle dispersibility, surface smoothness, mechanical properties, etc. of the obtained film are easily improved.

[0191] In one embodiment of the present invention, the solvent contained in the particulate polymer (B) dispersion may contain a solvent other than the first solvent and the second solvent, as long as the effects of the present invention are not impaired. The other solvent is not particularly limited, and any conventional solvent can be used. In one embodiment of the present invention, the total mass of the first solvent and the second solvent is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more, and preferably 100% by mass or less, based on the mass of the solvent contained in the dispersion. When the total mass of the first solvent and the second solvent is within the above range, aggregation of the particulate polymer (B) is easily suppressed, making it easy to reduce the particle size and improve the dispersibility of the particles. As a result, the water absorption resistance, particle dispersibility, surface smoothness, mechanical properties, etc. of the resulting film are easily improved.

[0192] The content of the particulate polymer (B) contained in the particulate polymer (B) dispersion obtained after distilling off the first solvent is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 1% by mass or more, and is preferably 50% by mass or less, more preferably 30% by mass or less, even more preferably 10% by mass or less, 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 within 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, particle dispersibility, surface smoothness, and mechanical properties are easily improved.

[0193] The particulate polymer (B) dispersion preferably contains particulate polymer (B) having a median diameter of 0.01 to 15 μm. The median diameter of the particulate polymer (B) is preferably 0.01 μm or more, more preferably 0.03 μm or more, and even more preferably 0.05 μm or more, and is preferably 15 μm or less, more preferably 10 μm or less, even more preferably 5 μm or less, even more preferably 3 μm or less, particularly preferably 1 μm or less, especially more preferably 0.8 μm or less, and especially more preferably 0.5 μm or less. When the median diameter of the particulate polymer (B) in the dispersion is at least the above-mentioned lower limit, the dielectric properties of the film formed from the composition are easily improved, and the film is easily produced. When the median diameter of the particulate polymer (B) in the dispersion is at most the above-mentioned upper limit, the brightness of the film formed from the composition is easily reduced, and mechanical properties such as particle dispersibility, water absorption resistance, surface smoothness, and flex resistance are easily improved. The median diameter of the particulate polymer (B) in the dispersion can be determined by laser diffraction scattering particle size distribution measurement. For example, as described in the Examples, the particulate polymer (B) dispersion is diluted with a solvent to prepare a dispersion sample, and the obtained dispersion sample is measured using a laser diffraction / scattering particle size distribution analyzer (manufactured by Malvern Panalytical, model: NanоZS, refractive index: 1.70-0.20i). In this specification, the median diameter is also referred to as D50, and indicates the value at which the number of particles of the particulate polymer (B) on the smaller side is equal to the number of particles on the larger side.

[0194] Step (3) is a step of adding a polyimide resin (A) to a dispersion of a particulate polymer (B). In step (3), the polyimide resin (A) may be in the form of a solid, preferably a powder, or may be in the form of a varnish obtained by dissolving the polyimide resin (A) in a predetermined solvent, such as a second solvent. In one embodiment of the present invention, in step (3), the polyimide resin or polyamic acid may be added in the form of a solid, preferably a powder, or 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, even more preferably 5% by mass or more, even more preferably 10% by mass or more, and preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, based on the mass of the varnish. When the content of the polyimide resin (A) in the varnish is within the above range, film formation is facilitated, which is advantageous from the viewpoint of film production.

[0195] The content of the polyimide resin (A) added in step (3) is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 65% ​​by mass or more, and preferably 95% by mass or less, more preferably 93% by mass or less, and even more preferably 90% by mass or less, based on the total mass of the polymer (B) and polyimide resin (A) in the particulate polymer (B) dispersion. When the content of the polyimide resin (A) added in step (3) is equal to or greater than the above-mentioned lower limit, film formation becomes easier, which is advantageous from the viewpoint of film production. Furthermore, when the content of the polyimide resin (A) added in step (3) is equal to or less than the above-mentioned upper limit, the dispersibility of the particulate polymer (B) in the dispersion and composition is likely to be improved, which tends to reduce variations in physical properties such as brightness, thermal conductivity, and thermal diffusivity of the resulting film, and tends to improve water absorption resistance, particle dispersibility, surface smoothness, and mechanical properties.

[0196] The method for adding the polyimide resin (A) to the particulate polymer (B) dispersion is not particularly limited, and the polyimide resin (A) may be added all at once, or may be added in multiple portions.

[0197] The composition preparation process according to one embodiment of the present invention may include steps other than steps (1) to (3), and may use polymers or additives other than the polyimide resin (A) and the polymer (B), such as the additives exemplified above, within the scope of not impairing the effects of the present invention. In a preferred embodiment of the present invention, the polyimide resin (A) is added to a dispersion of the particulate polymer (B), but the powder form of the polymer (B) may also be added to a varnish of the polyimide resin (A). As shown in the above step (3), the varnish of the polyimide resin (A) may be obtained by dissolving the polyimide resin (A) in a predetermined solvent, for example, a second 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 polyamic acid and a synthesis solvent).

[0198] The content of the particulate polymer (B) contained in the composition obtained in the composition preparation step is usually 1% by mass or more, preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, particularly preferably 20% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 35% by mass or less, particularly preferably 30% by mass or less, based on the total mass of the polyimide resin (A) and the particulate polymer (B). When the content of the particulate polymer (B) contained in the composition is above the above-mentioned lower limit, the dispersibility of the particulate polymer (B) is easily increased, which makes it easy to reduce the brightness of the obtained film and improves the water absorption resistance, particle dispersibility, surface smoothness, and mechanical properties. When the content of the particulate polymer (B) contained in the composition is below the above-mentioned upper limit, the brightness of the film is easily reduced and film formation is facilitated, which is advantageous from the viewpoint of film production. High particle dispersibility in the film increases the uniformity of the thermal conductivity or thermal diffusivity and the CTE, making it easier to prevent peeling between the film and copper foil when the film is used as a resin layer for CCL, for example. In a preferred embodiment of the present invention, the polyimide resin (A) is added to a dispersion of the particulate polymer (B), but the polymer (B) in powder form may also be added to a varnish of the polyimide resin (A).

[0199] 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% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, and is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, still more preferably 20% by mass or less, and particularly preferably 10% by mass or less. When the total mass of the polyimide resin (A) and the particulate polymer (B) contained in the composition is within the above range, the water absorption resistance, dielectric properties, and surface smoothness of the film are likely to be improved.

[0200] The content of the first 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, even more preferably 45 parts by mass or less, even more preferably 30 parts by mass or less, particularly preferably less than 30 parts by mass, particularly preferably 25 parts by mass or less, and preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more, relative to 100 parts by mass of the second solvent. When the content of the first solvent is below the above-mentioned upper limit, aggregation of the particulate polymer (B) is easily suppressed and the particle size is easily reduced, thereby easily improving dispersibility. Therefore, a film having low brightness, high water absorption resistance, surface smoothness, and excellent mechanical properties is easily obtained. Furthermore, when the content of the first solvent is below the above-mentioned upper limit, the film's thermal conductivity or thermal diffusivity uniformity, surface smoothness, and mechanical properties are easily improved. Furthermore, when the content of the first solvent is above the above-mentioned lower limit, the composition is easily prepared.

[0201] The content of the solvent in the composition obtained in the composition preparation step is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, particularly preferably 90% by mass or more, and preferably 99% by mass or less, more preferably 97% by mass or less, and even more preferably 95% by mass or less, based on the mass of the composition. When the solvent content is within the above range, aggregation of the particulate polymer (B) is easily suppressed, and the particle size is easily reduced, which makes it easy to improve dispersibility. Therefore, a film having high water absorption resistance, surface smoothness, and excellent mechanical properties is easily obtained. Furthermore, when the solvent content is above the above lower limit, the resulting composition is easily kneaded, which makes it easy to improve the formability of the film. When the solvent content is below the above upper limit, it is easy to suppress sedimentation or floating of the particulate polymer (B) in the resulting composition, which makes it easy to improve the dispersibility of the particulate polymer (B).

[0202] The solvent contained in the composition obtained in the composition preparation step may contain a solvent other than the first solvent and the second solvent, as long as the effects of the present invention are not impaired. The other solvent is not particularly limited, and any conventional solvent can be used. In one embodiment of the present invention, the total mass of the first solvent and the second solvent is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and preferably 100% by mass or less, based on the mass of the solvent contained in the composition. When the total mass of the first solvent and the second solvent is within the above range, aggregation of the particulate polymer (B) is easily suppressed, and the particle size is easily reduced, which makes it easy to improve dispersibility. Therefore, a film having high water absorption resistance, surface smoothness, and excellent mechanical properties can be easily obtained.

[0203] The median diameter of the particulate polymer (B) in the composition obtained in the composition preparation step can be selected from the same range as the median diameter of the particulate polymer (B) in the dispersion. The method for determining the median diameter of the particulate polymer (B) in the composition is not particularly limited, and can be determined, for example, using a centrifugal sedimentation particle size distribution analyzer or an ultrasonic attenuation particle size distribution analyzer. In step (3), when the composition is formed by adding polyimide resin (A) to the particulate polymer (B) dispersion in an amount that does not affect the particle diameter of the particulate polymer (B), the particle diameter in the dispersion can also be measured and used as the particle diameter in the composition.

[0204] The composition obtained in the composition preparation step may contain the additives exemplified above, if necessary. In one embodiment of the present invention, the composition of the present invention is produced by the above-described method of the present invention, and therefore, even without containing a compatibilizer, the particle size of the particulate polymer (B) is small and the dispersibility is excellent. Therefore, the content of the compatibilizer in the composition of the present invention is preferably 5 parts by mass or less, more preferably 1 part by mass or less, even more preferably 0.1 parts by mass or less, even more preferably less than 0.1 parts by mass, particularly preferably 0.05 parts by mass or less, particularly preferably 0.01 parts by mass or less, especially more preferably 0.001 parts by mass or less, and most preferably 0 parts by mass, per 100 parts by mass of the polyimide resin (A). Furthermore, when the polyimide resin (A) is a polyimide resin precursor such as polyamic acid and thermal imidization is required during film production, the content of the compatibilizer is preferably less than 0.1 parts by mass within the above range, from the viewpoint of preventing the compatibilizer from inhibiting imidization and preventing deterioration of film properties due to the compatibilizer's deterioration due to heating. The content of the compatibilizer may be based on 100 parts by mass of the total of the polyimide resin (A) and the polymer (B) instead of 100 parts by mass of the polyimide resin (A).

[0205] (Coating process and film forming process) 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.

[0206] In the coating step, the composition is applied to a substrate to form a coating film by a known coating method, such as roll coating methods such as wire bar coating, reverse coating, and gravure coating, die coating, comma coating, lip coating, spin coating, screen printing coating, fountain coating, dipping, spraying, curtain coating, slot coating, and drip molding.

[0207] Examples of the substrate include copper plates (including copper foil), SUS plates (including SUS foil and SUS belt), glass substrates, PET films, PEN films, other polyimide resin films, polyamide resin films, etc. Among these, from the viewpoint of excellent heat resistance, copper plates, SUS plates, glass substrates, PET films, PEN films, etc. are preferred, and from the viewpoints of adhesion to the film and cost, copper plates, SUS plates, glass substrates, PET films, etc. are more preferred.

[0208] In the film formation step, the coating film is dried and peeled off from the substrate to form a film. In one embodiment of the present invention, when the substrate is copper foil, the coating film is formed without peeling off the copper foil, and the resulting laminate in which the film is laminated on the copper foil can be used as a copper-clad laminate. In the case of peeling, a drying step for drying the film after peeling may be further performed. The drying temperature of the coating film can be appropriately selected depending on the heat resistance of the polyimide resin (A), etc., but in one embodiment of the present invention, it can be performed at a temperature of 50 to 450°C, preferably 70 to 400°C, and in another embodiment of the present invention, it can be performed at a temperature of 50 to 350°C, preferably 70 to 300°C. In a preferred embodiment of the present invention, stepwise drying is preferred. Stepwise drying allows the composition to be dried uniformly, which makes it easier to reduce the brightness of the resulting film, thereby making it easier to improve water absorption resistance. In addition, the Tg of the resulting film is improved, making it easier to reduce the CTE and improve the mechanical properties and surface smoothness. For example, the coating may be heated at a relatively low temperature of 50 to 150°C, followed by heating at 200 to 450°C, preferably 200 to 350°C. The drying or heating time is preferably 5 minutes to 10 hours, more preferably 10 minutes to 5 hours. By gradually heating from a low temperature to a high temperature within this range, the water absorption resistance, uniformity of thermal conductivity or thermal diffusivity, optical properties, and Tg of the resulting film are likely to be improved. If necessary, the coating may be dried in an inert atmosphere such as nitrogen or argon, under vacuum or reduced pressure, and / or under ventilation. When drying is performed in stages, the coating film may be peeled off from the substrate between stages and then continued to dry, or the coating film (film) may be peeled off from the substrate after all drying steps are completed. For example, the coating film may be peeled off from the substrate after the first stage of drying and then the second and subsequent stages of drying may be performed, or the coating film (film) may be peeled off from the substrate after all drying steps are completed. The first stage of drying may be preliminary drying.

[0209] When the substrate is a copper foil, the film may be peeled off from the copper foil substrate by, for example, etching the copper foil with a ferric chloride solution or the like.

[0210] In one embodiment of the present invention, when the polyimide resin (A) in the composition is a polyimide resin precursor, such as a polyamic acid, and a polyimide resin is produced during film production, the composition is preferably applied to a substrate and then heated for thermal imidization. This heating allows for simultaneous drying to remove the solvent and thermal imidization. The drying and imidization temperatures are typically in the range of 50 to 450°C, and from the standpoint of easily obtaining a smooth film with excellent water absorption resistance, it is preferable to heat in stages. For example, the solvent may be removed by heating at a relatively low temperature of 50 to 150°C, and then the composition may be heated in stages to a temperature in the range of 300 to 450°C. The heating time can be selected, for example, from the same range as above.

[0211] When the film of the present invention is a multilayer film, it can be produced by a multilayer film forming method such as coextrusion, extrusion lamination, thermal lamination, or dry lamination.

[0212] [Composition] The present invention also encompasses a composition comprising a polyimide resin (A), a particulate polymer (B), and a solvent, the solvent comprising a first solvent and a second solvent, wherein the distance between the HSP values ​​of the second solvent and the particulate polymer (B) is 8.5 or greater. In a preferred embodiment of the present invention, the composition of the present invention is preferably the composition described in the above section [Film production method], and the polyimide resin (A), particulate polymer (B), and solvent contained in the composition are the same as those described in the sections [Film] and [Film production method].

[0213] The composition of the present invention comprises a polyimide resin (A), a particulate polymer (B), and a solvent, the solvent comprising a first solvent and a second solvent. The distance between the HSP values ​​of the second solvent and the particulate polymer (B) is 8.5 or greater, resulting in reduced brightness and, as a result, a film with improved water absorption resistance. The composition of the present invention can also form a film with a reduced CTE compared to conventional composite films. Furthermore, the composition of the present invention can form a film that exhibits excellent mechanical properties, such as flex resistance, despite the high Tg of the polymer (B). Therefore, the composition of the present invention can form a film that combines excellent mechanical properties, such as water absorption resistance, surface smoothness, heat resistance, and flex resistance, with a reduced CTE. [Example]

[0214] The present invention will be described in more detail 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 described.

[0215] <lightness> The composite films obtained in the examples and comparative examples were evaluated for the brightness of reflected light (L * ) was evaluated on both sides of the film using a spectrophotometer under the following conditions. Device: Konica Minolta CM3700A Light source: D light source Incident light: Irradiated at an angle of 2° from the normal direction to the film Detection mode: Reflection SCE Target mask: LAV mask (measurement range: diameter 8 mm) Sample measurement conditions: The film was placed at the reflection measurement position and covered with a dark box.

[0216] <Haze> The composite films obtained in the examples and comparative examples were measured using a haze meter under the following conditions based on JIS K 7136. The measured value was the average of five measurements. Equipment: HM-150 manufactured by Murakami Color Technology Institute Co., Ltd. Number of measurements: 5

[0217] <Norbornene (NB) content> The content of norbornene-derived monomer units (also referred to as "NB content") in the cycloolefin copolymer obtained in the production example was: 13 Measurement was performed using C-NMR. 13 The C-NMR measurement conditions are as follows: Equipment: Bruker AVANCE600, 10mm cryoprobe Measurement temperature: 135℃ Measurement method: Proton decoupling method Concentration: 100mg / mL Number of times accumulated: 1024 Pulse width: 45 degrees Pulse repetition time: 4 seconds Chemical shift values ​​based on tetramethylsilane Solvent: A mixed solvent of 1,2-dichlorobenzene-d4 and 1,1,2,2-tetrachloroethane-d2 in a volume ratio of 85:15 The NB content in the cycloolefin copolymer was calculated based on 1,2-dichlorobenzene (127.68 ppm) as the standard, based on the assignments described in "RAWendt, G. Fink, Macromol. Chem. Phys., 2001, 202, 3490." Specifically, 13 Signal integral value observed at chemical shift values ​​of 44.0-52.0 ppm in the spectrum chart measured using C-NMR: I C2,C3(derived from the 2nd and 3rd carbon atoms of the norbornene ring), signal integral value observed at chemical shift values ​​of 27.0-33.0 ppm: I C5,C6 +I CE (derived from the carbon atoms at positions 5 and 6 of the norbornene ring and the carbon atom of the ethylene moiety) was calculated using the following formula. NB content (mol%)=I C2,C3 / (I C5,C6 +I CE ) x 100

[0218] <Hansen Solubility Parameter (HSP) and Distance Between HSP Values> The Hansen solubility parameters (HSP) and the distance between HSP values ​​of the cycloolefin copolymer, polyimide resin, solvent and fluoropolymer obtained in the Production Examples were determined as follows.

[0219] (Hansen Solubility Parameter (HSP) of the solvent) The HSP value of the solvent was taken from the database of HSPiP (Ver. 4.1.07), and the δD of GBL was 18.0 MPa. 0.5 , δP is 16.6 MPa 0.5 , δH is 7.4 MPa 0.5 The δD of DMAc is 16.8 MPa. 0.5 , δP is 11.5 MPa 0.5 , δH is 9.4 MPa 0.5 and δD of toluene is 18.0 MPa. 0.5 , δP is 1.4 MPa 0.5 , δH is 2.0 MPa 0.5 It was decided.

[0220] (HSP of cycloolefin copolymer) The solubility of cycloolefin copolymers in various solvents was evaluated. To evaluate solubility, 10 mL of a solvent with known solubility parameters (see the HSPiP database; solvents used: methyl chloride, 1,4-dichlorobenzene, chloroform, toluene, p-xylene, GBL, DMAc, NMP, water, acetone, diiodomethane, and butyl benzoate) and 0.1 g of cycloolefin copolymer were placed in a transparent container to prepare a mixture. The resulting mixture was subjected to ultrasonic treatment for a total of 6 hours. The appearance of the mixture after ultrasonic treatment was visually observed, and the solubility of each resin in the solvent was evaluated based on the observation results and the following evaluation criteria. (Evaluation criteria) 2: At room temperature, the mixture appears cloudy and precipitates have formed, but by heating to 50°C and stirring with a stirrer for 30 minutes, the mixture becomes transparent. 1: The mixture appears clear at room temperature. 0: The appearance of the mixture is cloudy at room temperature, and precipitates have formed. Even after heating to 50°C and stirring with a stirrer for 30 minutes, the appearance of the mixture does not become transparent.

[0221] From the evaluation results of the solubility of the obtained cycloolefin copolymer in a solvent, the HSP value was calculated using HSPiP by the above-mentioned Hansen dissolved sphere method.

[0222] (HSP of polyimide resin) The solubility of polyimide resins in various solvents was evaluated. To evaluate solubility, 10 mL of a solvent with known solubility parameters (see the HSPiP database; solvents used: acetone, toluene, ethanol, tetrahydrofuran, N,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, and acetic acid) was placed in a transparent container and mixed with 0.1 g of polyimide resin. The resulting mixture was subjected to ultrasonic treatment for a total of 6 hours. The appearance of the mixture after ultrasonic treatment was visually observed, and the solubility of each resin in the solvent was evaluated based on the observation results and the following criteria. (Evaluation criteria) 1: The mixture appears cloudy. 0: The appearance of the mixture is transparent.

[0223] From the evaluation results of the solubility of the obtained polyimide resin in a solvent, the HSP value was calculated using HSPiP by the above-mentioned Hansen dissolved sphere method.

[0224] (Fluoropolymer (PTFE) HSP) The HSP value of PTFE was determined from the value given in the literature (Marion K. Buckley-Smith, "The Use of Solubility Parameters to Select Membrane Materials for Pervaporation of Organic Mixtures", The University of Waikato, Hamilton, New Zealand, 2006, p. 52). δD was 17.1 MPa. 0.5 , δP is 8.1 MPa 0.5 , δh is 1.3 MPa 0.5 It was decided.

[0225] (Distance between HSP values) The distance between the HSP values ​​of two substances (Ra) was calculated according to formula (Y).

[0226] <Meso-type dipeptide chain / racemo-type dipeptide chain> The ratio of meso-type norbornene dimers to racemo-type norbornene dimers (meso-type dimers / racemo-type dimers) in the cycloolefin copolymer obtained in the production example was: 13 The measurement was performed using C-NMR under the same conditions as in the measurement of the NB content described above. The meso-type di-chain / racemo-type di-chain ratio of the norbornene di-chain was calculated based on the assignments described in "RAWendt, G. Fink, Macromol. Chem. Phys., 2001, 202, 3490" and "JP 2008-285656 A" using 1,1,2,2-tetrachloroethane (74.24 ppm) as a standard. Specifically, the meso-type di-chain / racemo-type di-chain ratio is 13 Signal integral value observed at chemical shift values ​​of 27.5-28.4 ppm in the spectrum chart measured using C-NMR: I C5,C6 -m (derived from the carbon atoms at positions 5 and 6 of the meso-type two-chain norbornene ring), signal integral value observed at chemical shift value 28.4-29.6 ppm: I C5,C6 -r (derived from the carbon atoms at positions 5 and 6 of the racemo-type two-chain norbornene ring) was calculated using the following formula. Meso-type dipeptide / racemo-type dipeptide = I C5,C6 -m / I C5,C6 -r

[0227] <Refractive index> The refractive index of the cycloolefin copolymer obtained in the Production Examples was determined by measuring under the following conditions using a sheet-like sample formed to a thickness of 100 μm using a vacuum press. Equipment: Atago Co., Ltd. Abbe refractometer, TYPE-3 Light source wavelength: 589.3nm Intermediate solution: 1-bromonaphthalene Measurement temperature: 23±1℃

[0228] <Glass transition temperature> (cycloolefin copolymer) The Tg of the cycloolefin copolymer obtained in the Production Examples was determined by measuring the softening temperature by TMA in accordance with JIS K 7196. Specifically, a sample (thickness: 1.0 mm) obtained by molding the cycloolefin copolymer into a sheet using a vacuum press was measured under the following conditions, and the onset of displacement when the indenter sinks into the sample was taken as the softening temperature. Equipment: Hitachi High-Tech Science, TMA / SS6200 Indenter diameter: 1 mm Load: 780mN Temperature program: 20°C to 380°C at a rate of 5°C / min

[0229] (Polyimide resin) The Tg of the polyimide resin obtained in the Production Examples was determined by the following measurement: Measurement was performed using a DMA Q800 manufactured by TA Instruments under the following conditions and samples to obtain a tan δ curve, which is the ratio of the loss modulus to the storage modulus, and then the Tg was calculated from the apex of the peak of the tan δ curve. Sample: length 5-15mm, width 5mm Experimental mode: DMA Multi-Frequency-Strain Experimental mode detailed conditions: (1) Clamp: Tension: Film (2) Amplitude: 5 μm (3) Frequency: 10Hz (no fluctuations over the entire temperature range) (4) Preload Force: 0.01N (5) Force Track: 125N Temperature conditions: (1) Temperature range: room temperature to 400°C, (2) Temperature rise rate: 5°C / min Main collected data: (1) Storage modulus (E'), (2) Loss modulus (E"), (3) tan δ (E" / E')

[0230] <Mw and Mn of cycloolefin copolymer> The polystyrene-equivalent Mw and Mn of the cycloolefin copolymers obtained in the Production Examples were measured using GPC. The GPC measurement was carried out under the following conditions, and peaks were designated by defining the baseline on the chromatogram based on the description in ISO16014-1.

[0231] (GPC equipment and software) Apparatus: HLC-8121GPC / HT (manufactured by Tosoh Corporation) Measurement software: GPC-8020 model II Data Collection Version 4.32 (Tosoh Corporation) Analysis software: GPC-8020 model II Data Analysis Version 4.32 (Tosoh Corporation)

[0232] (Measurement conditions) GPC column: TSKgel GMH6-HT 7.8 mm ID x 300 mm (Tosoh Corporation), 3 columns connected Mobile phase: Orthodichlorobenzene (Fujifilm Wako Pure Chemical Industries, Ltd., special grade) was used with 2,6-di-tert-butyl-4-methylphenol (hereinafter sometimes referred to as BHT) added at a concentration of 0.1 w / V, i.e., 0.1 g / 100 mL. Flow rate: 1mL / min Column oven temperature: 140°C Autosampler temperature: 140℃ System oven temperature: 40°C Detection: Refractive index detector (RID) RID cell temperature: 140℃ Sample solution injection volume: 300 μL GPC column calibration standard: Standard polystyrene manufactured by Tosoh Corporation was weighed out in the combinations shown in Table 1 below, and 5 mL of orthodichlorobenzene with the same composition as the mobile phase was added to each combination, and the mixture was dissolved at room temperature for 2 hours to prepare a solution. The column was calibrated using the obtained GPC column calibration standard, and then sample measurements were carried out as shown below.

[0233] [Table 1]

[0234] (Sample solution preparation conditions) Solvent: Orthodichlorobenzene (special grade, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) to which BHT was added at a concentration of 0.1 w / V, that is, 0.1 g / 100 mL. Sample solution concentration: 1 mg / mL Automatic dissolution shaker: DF-8020 (Tosoh Corporation) Dissolution conditions: 5 mg of sample was sealed in a 1,000 mesh stainless steel wire bag, the wire bag containing the sealed sample was placed in a test tube, 5 mL of orthodichlorobenzene with the same composition as the mobile phase was added, the test tube was covered with aluminum foil, the test tube was placed in the DF-8020, and stirred at 140°C for 120 minutes at a stirring speed of 60 strokes per minute. GPC measurement was performed on the solution after stirring.

[0235] <Mw of polyimide resin> The polystyrene-equivalent Mw of the polyimide resins obtained in the Production Examples was measured using GPC under the following conditions. GPC measurement (1) Pretreatment method A DMF eluent (DMF solution containing 10 mmol / L lithium bromide) was added to the sample to a concentration of 2 mg / mL, and the mixture was heated at 80°C for 30 minutes with stirring. After cooling, the mixture was filtered through a 0.45 μm membrane filter to prepare a measurement solution. (2) Measurement conditions Column: TSKgel SuperAWM-H x 2 + SuperAW2500 x 1 (inner diameter 6.0 mm, length 150 mm, 3 columns connected) Eluent: DMF (10 mmol / L lithium bromide added) Flow rate: 1.0mL / min Detector: RI detector Column temperature: 40℃ Injection volume: 100μL Molecular weight standard: Standard polystyrene

[0236] <Evaluation of solubility> The evaluation of whether the cycloolefin copolymer, PTFE, and polyimide resin were soluble in the solvents used in the Examples and Comparative Examples was carried out as follows. First, 9.9 g of solvent was weighed into a 30 mL glass screw tube and stirred with a magnetic stirrer. 0.1 g of polymer or resin was added and stirred at 24°C for 24 hours. After 24 hours of stirring, if no solids were visible and the solution was transparent, it was rated as "dissolved." On the other hand, if solids were visible or the solution was opaque, it was rated as "not dissolved." <Particle size of particulate cycloolefin copolymer in dispersion and composition, and particle size of particulate PTFE in dispersion and composition> The median 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 the examples was placed in a 3.5 mL glass cell and further diluted 1000 times with GBL or DMAc (using the same solvent as the dispersion) to obtain a dispersion sample containing particulate cycloolefin copolymer or PTFE. The obtained dispersion sample was measured using a laser diffraction / scattering particle size distribution analyzer (manufactured by Malvern Panalytical, model: NanоZS, refractive index: 1.70-0.20i) to determine the median diameter of the particulate cycloolefin copolymer and particulate PTFE. As described above, in the examples and comparative examples, the polyimide resin was added to the dispersion in an amount that did not affect the particle diameters of the particulate cycloolefin copolymer and particulate PTFE to form the composition, and therefore the median diameters of the particulate cycloolefin copolymer and particulate PTFE in the dispersion were taken as the median diameters of the particulate cycloolefin copolymer and particulate PTFE in the composition.

[0237] <Thickness of composite film> The thickness of the composite films obtained in the examples and comparative examples was measured at any five or more points on the film using a Digimatic Indicator (ID-C112XBS, manufactured by Mitutoyo Corporation), and the average value of these measurements was used as the thickness of the composite film.

[0238] <Solvent Content in Particulate Cycloolefin Copolymer Dispersion and Particulate PTFE Dispersion> The solvent contents in the particulate cycloolefin copolymer dispersions and particulate PTFE dispersions obtained in the examples and comparative examples were measured by gas chromatography. Specifically, the measurements were carried out under the following conditions, and the solvent contents in the cycloolefin copolymer dispersions and particulate PTFE dispersions were calculated by the following inspection method. Apparatus: Agilent 7890B gas chromatograph (Agilent Technologies, Inc.) Column: DB-5 (Agilent Technologies) Carrier gas: Helium Inlet temperature: 200℃ Detector temperature: 250℃ Internal standard solution: benzyl alcohol Solvent: Chloroform

[0239] <cte> (CTE of composite film) The CTE of the composite films obtained in the examples and comparative examples was measured by TMA. Specifically, the measurement was carried out under the following conditions, and the CTE was calculated from the temperature range of 50°C to 100°C. Equipment: Hitachi High-Tech Science TMA / SS7100 Indenter (probe) diameter: 3.5 mm Load: 50.0mN Temperature program: 20°C to 130°C at a rate of 5°C / min Test piece: 40mm x 10mm x 50μm rectangular parallelepiped

[0240] (CTE of cycloolefin copolymer) The CTE of the cycloolefin copolymer was measured using TMA under the following conditions, and the CTE at 50°C to 100°C was calculated. Equipment: Hitachi High-Tech Science TMA / SS6200 Indenter (probe) diameter: 3.5 mm Load: 38.5 mN Temperature program: 20°C to 130°C at a rate of 5°C / min Test piece: 10mm x 10mm x 1mm rectangular parallelepiped

[0241] <Water absorption rate of composite film> The composite films obtained in the examples and comparative examples were cut into pieces measuring 100 mm × 90 mm. The cut composite films were dried at 80°C for 3 hours, and then the mass of the composite film was measured and designated as the mass W0 before exposure to water vapor. A cylindrical beaker with a diameter of 75 mm was prepared, and 150 g of water was placed in it. The beaker was then placed on a hot plate set to 120°C and the water was brought to a boil. While the water was boiling, the beaker was covered with a metal plate to prevent steam from escaping. After the water had sufficiently boiled, the metal plate lid was removed, and the beaker was covered with the composite film, with the side opposite to the side that had been in contact with the glass substrate during film formation being the side that came into contact with the steam. This was then covered with another metal plate, and the composite film was exposed to water vapor. After 5 minutes, the composite film was removed and its mass was measured, and this was taken as the mass after water vapor exposure, W1. The water absorption (%) of the film was calculated using the following formula: Water absorption rate (%)=(W1-W0) / W1×100

[0242] <Standard deviation of average thickness of composite film> The standard deviation of the average thickness of the composite films obtained in the examples and comparative examples was calculated as follows. A thickness profile (height profile) was obtained for any continuous linear 1 mm area on the surface of a film fixed to a glass substrate in close contact with the surface using a tactile surface profilometer (Dektak XTE, Bruker Japan Co., Ltd.), with the glass substrate as the reference plane. The area was divided into 10 equal measurement areas, and the average thickness (average height) for each of the 10 measurement areas was determined. The standard deviation of the average thickness of the composite film was then calculated from the average thickness data for the 10 points in each measurement area.

[0243] <Reagent details> To synthesize the cycloolefin copolymer, toluene manufactured by Sumitomo Chemical Co., Ltd., styrene manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 2-norbornene (hereinafter referred to as NB) manufactured by Arakawa Chemical Industries, Ltd., triisobutylaluminum (hereinafter referred to as TIBA) manufactured by Tosoh Finechem Corporation, and N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate (hereinafter referred to as AB) manufactured by AGC Corporation were used.

[0244] The toluene was dehydrated using molecular sieves 13X (manufactured by Union Showa Co., Ltd.) and activated alumina (manufactured by Sumitomo Chemical Co., Ltd., NKHD-24), and then nitrogen gas was blown in to remove dissolved oxygen before use.

[0245] NB was dissolved in toluene, dehydrated using molecular sieves 13X (Union Showa Co., Ltd.) and activated alumina (NKHD-24, Sumitomo Chemical Co., Ltd.), and then nitrogen gas was blown into the solution to remove dissolved oxygen (hereinafter referred to as NB solution). The NB concentration in the NB solution was measured using gas chromatography.

[0246] Isopropylidene(cyclopentadienyl)(3-tert-butyl-5-methyl-2-phenoxy)titanium dichloride (hereinafter referred to as complex) was synthesized according to the method described in Japanese Patent Application Laid-Open No. 9-183809.

[0247] [Production of Cycloolefin Copolymer Solution 1] <Production Example 1> An autoclave with its interior dried under reduced pressure was charged with 1,501 mL of NB solution (NB concentration: 3.00 mol / L) and heated to 60°C. While stirring, the system was pressurized to an ethylene partial pressure of 100 kPa, and then 4.0 mL of a hexane solution of TIBA (concentration: 1.0 mol / L), 0.16 g of AB, and 10.0 mL of a toluene solution of the complex (concentration: 10 mmol / L) were added to initiate the polymerization of ethylene and NB. During the polymerization, the temperature in the system was maintained at 60°C, and ethylene was continuously supplied to maintain the pressure in the system at the initial value. Three hours after the start of polymerization, 5.0 mL of water was added to terminate the polymerization, and the solution in the autoclave was discharged. 1,500 g of toluene and 100 g of magnesium sulfate were added to the discharged solution and stirred. Next, 100 mL of water was added and stirred, and the solid was removed by filtration. The resulting liquid was added dropwise to acetone, and the precipitated powder was isolated by filtration. The isolated powder was further washed with acetone and dried under reduced pressure at 120°C for 2 hours to obtain 210.0 g of cycloolefin copolymer. The resulting cycloolefin copolymer had an NB content of 84.1 mol%, a Tg of 293°C, an Mw of 521,000, an Mw / Mn of 1.87, and a CTE of 49.4 ppm / K. The δD of the cycloolefin copolymer was 17.7 MPa. 0.5 and δP is 2.1 MPa. 0.5 and δH is 3.9 MPa. 0.5 The meso-type double chain / racemo-type double chain ratio was 0.19, and the refractive index was 1.538. The synthesis conditions for Production Example 1 are shown in Table 2. This cycloolefin copolymer was dissolved in a toluene solution at a concentration of 2% by mass, to obtain cycloolefin copolymer solution 1.

[0248] [Table 2]

[0249] [Production of crushed cycloolefin copolymer powder] <Production Example 2> A reactor with the interior dried under reduced pressure was charged with 611.7 L of NB solution (NB concentration: 3.00 mol / L) and heated to 60°C. While stirring, the system was pressurized to 100 kPa of ethylene partial pressure, and then 0.51 L of a hexane solution of TIBA (concentration: 0.6 mol / L), 40.8 L of a toluene solution of AB (concentration: 1.0 mmol / L), and 2.0 L of a toluene solution of the complex (concentration: 10 mmol / L) were added to initiate the polymerization of ethylene and NB. The temperature in the system was maintained at 60°C during the polymerization, and ethylene was continuously supplied to maintain the pressure in the system at the initial value. After the ethylene consumption reached 3.0 kg from the start of polymerization, 1.0 L of water was added to terminate the polymerization. 612 L of an aqueous NaOH solution (concentration: 0.1 mol / L) was added to the reactor and stirred for 30 minutes. The stirring was stopped, the aqueous solution was removed, and 612 L of water was added and stirred for 30 minutes. Further, 612 L of water was added and stirred for 30 minutes. Then, a solution of 942 L of toluene and 49.5 L of acetone was added to the reaction vessel, followed by 314 L of acetone. The precipitated powder was isolated by filtration. The isolated powder was further washed with acetone and dried under reduced pressure at 120°C for 2 hours to obtain 60.0 kg of cycloolefin copolymer. The obtained cycloolefin copolymer had an NB content of 92.3 mol%, a Tg of 308°C, an Mw of 852,000, and an Mw / Mn of 1.81. The δD of the cycloolefin copolymer was 17.7 MPa. 0.5 and δP is 2.1 MPa. 0.5 and δH is 3.9 MPa. 0.5 and the CTE was 44.5 ppm / K. This cycloolefin copolymer was pulverized in a counter jet mill manufactured by Hosokawa Micron Corporation and classified using a filter to obtain a pulverized powder of cycloolefin copolymer, which was particles with a median diameter of 2.6 μm.

[0250] [Preparation of Cycloolefin Copolymer Solution 2] <Production Example 3> 1,427 mL of NB solution (NB concentration: 3.00 mol / L) and 55.2 mL of styrene were added to an autoclave whose interior had been dried under reduced pressure, and the temperature was raised to 80°C. While stirring the system, 3.0 mL of a hexane solution of TIBA (concentration: 1.0 mol / L), 0.32 g of AB, and 15.0 mL of a toluene solution of the complex (concentration: 10 mmol / L) were added to initiate the polymerization of NB and styrene. The temperature of the system was maintained at 80°C during the polymerization. Two hours after the start of polymerization, 3.0 mL of water was added to terminate the polymerization, and the solution in the autoclave was removed. The resulting liquid was added dropwise to acetone, and the precipitated powder was isolated by filtration. The isolated powder was further washed with acetone and dried under reduced pressure at 150°C for 2 hours, yielding 198.3 g of cycloolefin copolymer. The obtained cycloolefin copolymer had an NB content of 96.3 mol%, an Mw of 79,000, an Mw / Mn of 1.83, and a Tg of over 300° C. The δD of the cycloolefin copolymer was 17.7 MPa. 0.5 and δP is 2.1 MPa. 0.5 and δH is 3.9 MPa. 0.5 The synthesis conditions for Production Example 3 are shown in Table 3. This cycloolefin copolymer was dissolved in a toluene solution at a concentration of 2% by mass to obtain cycloolefin copolymer solution 2.

[0251] [Table 3]

[0252] [Synthesis of polyimide resin] <Production Example 4> A reactor equipped with a separable flask, a silica gel tube, a stirrer, and a thermometer, and an oil bath were prepared. After creating a nitrogen atmosphere in the flask using dry nitrogen, 75.52 g of 6FDA and 54.44 g of TFMB were added. While stirring at 400 rpm, 519.84 g of DMAc was added, and stirring continued until the contents of the flask became a homogeneous solution. The temperature inside the vessel was then adjusted to 20-30°C using an oil bath, and stirring continued for an additional 20 hours to allow the reaction to produce polyamic acid. After 30 minutes, the stirring speed was changed to 100 rpm. After stirring for 20 hours, the reaction system temperature was returned to room temperature, and 649.8 g of DMAc was added to adjust the polymer concentration to 10% by mass. Furthermore, 32.27 g of pyridine and 41.65 g of acetic anhydride were added, and the mixture was stirred at room temperature for 10 hours to carry out imidization. The polyimide varnish was then removed from the reactor. The obtained polyimide varnish was dropped into methanol to cause reprecipitation, and the obtained powder was heated and dried to remove the solvent, yielding a polyimide resin as a solid. The δD of the obtained polyimide resin was 18.1 MPa. 0.5 and δP is 8.3 MPa. 0.5 and δH is 9.3 MPa. 0.5 The polyimide resin had an Mw of 334,300 and a Tg of 361°C.

[0253] [Synthesis of polyamic acid] <Production Example 5> A reactor equipped with a separable flask, a silica gel tube, a stirrer, and a thermometer, and an oil bath were prepared. 27.83 g of BPDA, 13.76 g of PMDA, and 34.00 g of m-TB were placed in the flask. While stirring at 400 rpm, 428.35 g of DMAc was added, and stirring was continued until the contents of the flask became a homogeneous solution. Next, stirring was continued for an additional 3 hours while adjusting the temperature inside the vessel to between 20 and 30°C using an oil bath, resulting in a polyamic acid solution dispersed in the solvent.

[0254] Example 1 100.0 g of the cycloolefin copolymer solution 1 obtained in Production Example 1 and 98.0 g of GBL were mixed, and the toluene was removed by vacuum distillation at 50 hPa and 80°C so that the toluene content was 7 parts by mass per 100 parts by mass of GBL, thereby obtaining a particulate cycloolefin copolymer dispersion. To 32.1 g of the resulting dispersion (1.9 mass% cycloolefin copolymer), 1.9 g of the polyimide resin obtained above was added to obtain a polyimide-cycloolefin copolymer mixed solution, resulting in a composition. The median diameter of the particulate cycloolefin copolymer in the dispersion and composition, measured by the above method, was 0.15 μm. No cycloolefin copolymer aggregates larger than 1 mm were observed in the resulting composition. The resulting composition was cast onto a glass substrate at a linear speed of 0.4 m / min to form a coating film. The coating film was heated at 70°C for 60 minutes, peeled from the glass substrate, and then fixed in a metal frame and heated at 200°C for 1 hour to obtain a 60 μm-thick polyimide-cycloolefin copolymer composite film. The content of particulate cycloolefin copolymer in the resulting composite film was 24 mass% relative to the total mass of the polyimide resin and particulate cycloolefin copolymer. The CTE of the resulting composite film was 44 ppm / K. The standard deviation of the average thickness of the resulting composite film was 0.4, and the film surface had excellent smoothness. The haze of the resulting composite film was 44.8%. The distance between the HSP values ​​of the cycloolefin copolymer and polyimide resin used in Example 1 was 8.3, the distance between the HSP values ​​of the cycloolefin copolymer and toluene was 2.1, the distance between the HSP values ​​of the polyimide resin and toluene was 10.0, the distance between the HSP values ​​of the cycloolefin copolymer and GBL was 14.9, and the distance between the HSP values ​​of the polyimide resin and GBL was 8.5. According to the above solubility evaluation method, the cycloolefin copolymer used in Example 1 was dissolved in toluene but not in GBL, and the polyimide resin was dissolved in GBL but not in toluene.

[0255] Example 2 A particulate cycloolefin copolymer dispersion was obtained in the same manner as in Example 1, except that toluene was removed by vacuum distillation at 50 hPa and 80°C so that the toluene content was 20 parts by mass per 100 parts by mass of GBL, and a particulate cycloolefin copolymer dispersion was obtained. To 35.9 g of the obtained particulate cycloolefin copolymer dispersion (1.7 mass % cycloolefin copolymer), 1.9 g of the polyimide resin obtained above was added to obtain a polyimide-cycloolefin copolymer mixed solution composition. The median diameter of the particulate cycloolefin copolymer in the dispersion and composition measured by the above method was 0.14 μm. No cycloolefin copolymer aggregates exceeding 1 mm were observed in the obtained composition. 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 obtained composite film was 24 mass % relative to the total mass of the polyimide resin and the particulate cycloolefin copolymer. The CTE of the obtained composite film was 44 ppm / K. The standard deviation of the average thickness of the obtained composite film was 0.37, and the film surface smoothness was also excellent. The haze of the obtained composite film was 50.5%.

[0256] Example 3 A particulate cycloolefin copolymer dispersion was obtained in the same manner as in Example 1, except that toluene was removed by vacuum distillation at 50 hPa and 80°C so that the toluene content was 30 parts by mass per 100 parts by mass of GBL, and a particulate cycloolefin copolymer dispersion was obtained. To 38.8 g of the obtained particulate cycloolefin copolymer dispersion (1.5 mass % cycloolefin copolymer), 1.9 g of the polyimide resin obtained above was added to obtain a polyimide-cycloolefin copolymer mixed solution composition. The median diameter of the particulate cycloolefin copolymer in the dispersion and composition measured by the above method was 0.13 μm. No cycloolefin copolymer aggregates exceeding 1 mm were observed in the obtained composition. 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 obtained composite film was 24 mass % relative to the total mass of the polyimide resin and the particulate cycloolefin copolymer. The CTE of the obtained composite film was 45 ppm / K, and the film surface was also excellent in smoothness. The haze of the obtained composite film was 65.7%.

[0257] Example 4 2.73 g of the cycloolefin copolymer crushed powder and 52.03 g of DMAc were mixed and stirred to obtain a dispersion liquid, the toluene content of which was 1.3 parts by mass per 100 parts by mass of DMAc. To the obtained dispersion, 100 g of polyamic acid solution (15% by mass of polyamic acid) was added to obtain a composition as a polyamic acid-cycloolefin copolymer mixed solution. The median diameter of the particulate cycloolefin copolymer in the dispersion and composition measured by the above method was 2.6 μm. No cycloolefin copolymer aggregates larger than 1 mm were observed in the obtained composition. The resulting composition was applied to a glass substrate by drip casting at a linear speed of 0.4 m / min to form a coating film. The coating film was heated at 50°C for 80 minutes, and the polyamic acid-cycloolefin copolymer composite film was peeled off from the glass substrate. The film was then fixed in a metal frame and further heated at 360°C for 15 minutes under a nitrogen atmosphere to imidize the polyamic acid, resulting in a 50 μm-thick polyimide-cycloolefin copolymer composite film. The content of the particulate cycloolefin copolymer in the resulting film was 15.4 mass% relative to the total mass of the polyimide resin and particulate cycloolefin copolymer. The CTE of the resulting composite film was 19 ppm / K, and the film surface had excellent smoothness. The haze of the resulting composite film was 98.9%. The distance between the HSP values ​​of the cycloolefin copolymer and polyamic acid used in Example 4 was 6.0 or more, and the distance between the HSP values ​​of the cycloolefin copolymer and DMAc was 11.5. In addition, the distance between the HSP values ​​of the cycloolefin copolymer used in Example 4 and the polyimide resin obtained by imidizing the polyamic acid was 6.0 or more. According to the above-mentioned solubility evaluation method, the cycloolefin copolymer used in Example 4 was dissolved in toluene but not in DMAc, and the polyamic acid was dissolved in DMAc but not in toluene.

[0258] Example 5 5.69 g of particulate PTFE (manufactured by Polysciences Inc., melting point: 320°C, Mw: 20,000), 41.9 g of DMAc, and 0.2 g of toluene were mixed and stirred to obtain a dispersion. The toluene content of the obtained dispersion was 0.5 parts by mass per 100 parts by mass of DMAc. 100 g of polyamic acid solution (15% by mass of polyamic acid) was added to the obtained dispersion to obtain a composition as a polyamic acid-PTFE mixed solution. The median diameter of the particulate PTFE in the dispersion and composition measured by the above method was 3 μm. No PTFE aggregates larger than 1 mm were observed in the obtained composition. The resulting composition was applied to a glass substrate by drip casting at a linear speed of 0.4 m / min to form a coating film. The coating film was heated at 50°C for 80 minutes, and the polyamic acid-PTFE composite film was peeled off from the glass substrate. The film was then fixed in a metal frame and heated stepwise to 360°C over 30 minutes under a nitrogen atmosphere to imidize the polyamic acid, resulting in a 50 μm-thick polyimide-PTFE composite film. The particulate PTFE content of the resulting film was 27.5 mass% relative to the total mass of the polyimide resin and PTFE. The CTE of the resulting composite film was 17 ppm / K, and the film surface had excellent smoothness. The haze of the resulting composite film was 88.0%. The distance between the HSP values ​​of the PTFE and polyamic acid used in Example 5 was 6.0 or more, and the distance between the HSP values ​​of the PTFE and DMAc was 9.5. The distance between the HSP values ​​of the PTFE and polyimide resin obtained by imidizing the polyamic acid used in Example 5 was also 6.0 or more. According to the above solubility evaluation method, the PTFE used in Example 5 was not dissolved in DMAc. Furthermore, the polyamic acid was dissolved in DMAc but not in toluene.

[0259] [Example 6] 100.0 g of the obtained cycloolefin copolymer solution 2 and 98.0 g of DMAc were mixed, and the toluene was removed by distillation under reduced pressure at 50 hPa and 80°C for 2 hours so that the toluene content was 0.6 parts by mass per 100 parts by mass of DMAc, thereby obtaining a particulate cycloolefin copolymer dispersion. The median diameter of the particulate cycloolefin copolymer in the particulate cycloolefin copolymer dispersion measured by the above method was 0.13 μm. To 10.92 g of the obtained particulate cycloolefin copolymer dispersion (particulate cycloolefin copolymer 2.0 mass %) was added 8.0 g of the polyamic acid solution to obtain a polyamic acid-cycloolefin copolymer mixed solution composition. In the obtained composition, no cycloolefin copolymer aggregates exceeding 1 mm were observed. The resulting composition was applied to a glass substrate by drip casting at a linear speed of 0.4 m / min to form a coating film. The coating film was heated at 70°C for 60 minutes, and the polyamic acid-cycloolefin copolymer composite film was peeled off from the glass substrate. The film was then fixed in a metal frame and heated in a nitrogen atmosphere to 360°C in stages over 30 minutes to imidize the polyamic acid, resulting in a 30 μm-thick polyimide-cycloolefin copolymer composite film. The content of the particulate cycloolefin copolymer in the resulting film was 15.4 mass% based on the total mass of the polyimide resin and particulate cycloolefin copolymer. The CTE of the resulting composite film was 18 ppm / K, and the surface smoothness of the resulting composite film was also excellent. The haze of the resulting composite film was 96.6%. The distance between the HSP values ​​of the cycloolefin copolymer and polyamic acid used in Example 6 was 6.0 or more, the distance between the HSP values ​​of the cycloolefin copolymer and toluene was 2.1, and the distance between the HSP values ​​of the cycloolefin copolymer and DMAc was 11.5. Furthermore, the distance between the HSP values ​​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-mentioned solubility evaluation method, the cycloolefin copolymer used in Example 6 was dissolved in toluene but not in DMAc. The polyamic acid used in Example 6 was dissolved in DMAc but not in toluene.

[0260] Comparative Example 1 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 50 hPa and 80°C so that the toluene content was 40 parts by mass relative to 100 parts by mass of GBL to obtain a particulate cycloolefin copolymer dispersion. The median diameter of the particulate cycloolefin copolymer in the dispersion and composition measured by the above method was 0.13 μm. To 41.8 g of the resulting dispersion (1.4 mass % cycloolefin copolymer), 1.9 g of the polyimide resin obtained above was added to obtain a polyimide-cycloolefin copolymer mixed solution composition. No cycloolefin copolymer aggregates larger than 1 mm were observed in the resulting composition. 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 obtained composite film was 24 mass % relative to the total mass of the polyimide resin and the particulate cycloolefin copolymer. The CTE of the obtained composite film was 44 ppm / K. 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%.

[0261] The haze, brightness, and water absorption of the polyimide-cycloolefin copolymer composite films and polyimide-PTFE composite films obtained in the Examples and Comparative Examples were measured according to the methods described above. The results are shown in Table 4. The brightness of the composite film was measured on both sides of the film, with the brightness of the side that was in contact with the glass substrate during film formation being indicated as L1 and the brightness of the opposite side being indicated as L2. Table 4 also shows the toluene content per 100 parts by mass of GBL or DMAc in the particulate cycloolefin copolymer dispersions and particulate PTFE dispersions in the Examples and Comparative Examples.

[0262] [Table 4]

[0263] As shown in Table 4, the films obtained in Examples 1 to 6 had low water absorption rates and were superior to Comparative Example 1 in water absorption resistance.< / cte>

Claims

1. A film comprising a polyimide-based resin (A) and a particulate polymer (B), the film having a haze of 75% or less and a reflected light brightness L measured by a specular reflection light excluding method. ＊ is 37 or less on both sides of the film, The polyimide resin (A) is represented by the formula (1): 【Chemical 1】 [In formula (1), X represents a divalent organic group, Y represents a tetravalent organic group, and * represents a bond.] It has a constitutional unit represented by The particulate polymer (B) has an average primary particle diameter of 3 μm or less.

2. A film comprising a polyimide-based resin (A) and a particulate polymer (B), the film having a haze of more than 75% and a reflected light brightness L measured by a specular reflection excluding method. ＊ is 80 or less on both sides of the film, The polyimide resin (A) is represented by the formula (1): 【Chemistry 2】 [In formula (1), X represents a divalent organic group, Y represents a tetravalent organic group, and * represents a bond.] It has a constitutional unit represented by The particulate polymer (B) has an average primary particle diameter of 3 μm or less.

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

4. 4. The film according to claim 1, 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).

5. The film according to any one of claims 1 to 4, wherein the polymer (B) is at least one polymer selected from the group consisting of an olefin-based polymer, a polyimide-based polymer, a fluorine-based polymer, a silicone-based polymer, a liquid crystal polymer, an aramid polymer, a styrene-based polymer, and an ether-based polymer.

6. The film according to any one of claims 1 to 5, wherein the polymer (B) is a cycloolefin-based polymer.

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

8. The cycloolefin-based polymer has the formula (I): 【Chemistry 3】 [In formula (I), m represents an integer of 0 or more, and R ７ ~R １８ each independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms; R １１ ~R １４ When a plurality of R １６ and R １７ may be bonded to each other to form a ring together with the carbon atoms to which they are attached. The film according to claim 6 or 7, comprising a cycloolefin-derived monomer unit (1) represented by the following formula:

Images