Compositions, laminates and films of tetrafluoroethylene-based polymers

Abstract

This invention provides a composition, and a laminate or film, in which the reduction of electrical properties is suppressed and the absorption rate of the tetrafluoroethylene-based polymer in the ultraviolet wavelength region is improved. This invention comprises particles of a tetrafluoroethylene-based polymer having a fluorine content of 70% by mass or more, and an ultraviolet absorber having a nitrogen-containing heterocyclic structure and hydroxyl groups and a molecular weight of 250 or more. This invention is a laminate or film having at least one layer comprising a tetrafluoroethylene-based polymer having a carbonyl group and a fluorine content of 70% by mass or more, and an ultraviolet absorber having a nitrogen-containing heterocyclic structure and hydroxyl groups and a molecular weight of 250 or more, and having an absorption rate of 80% or more for light with a wavelength of 255–355 nm at a thickness of 1 μm.

Description

[Technical Field]

[0001] The present invention relates to a composition comprising particles of a tetrafluoroethylene polymer and an ultraviolet absorber, and a laminate and a film having a layer comprising a tetrafluoroethylene polymer and an ultraviolet absorber, wherein the light absorption rate of a specific wavelength is within a specific range. [Previous Technology]

[0002] Tetrafluoroethylene polymers possess excellent physical properties such as electrical insulation, water and oil repellency, chemical resistance, and heat resistance, and can be used to form materials such as photoresists, adhesives, electrical insulating layers, lubricants, inks, and coatings. In particular, tetrafluoroethylene polymers have relatively low relative permittivity and dielectric loss tangent, therefore, laminates with tetrafluoroethylene polymer layers are suitable for use in printed wiring boards (see Patent Document 1).

[0003] However, tetrafluoroethylene (TEF) polymers have low light absorption in the ultraviolet wavelength region, while high-output laser irradiation is required during UV (ultraviolet) laser processing of printed wiring boards. When irradiated with such a high-output laser, there are concerns about deformation of the TEF polymer layer due to heat generation. Therefore, it is sometimes attempted to incorporate ultraviolet absorbers into TEF polymers to improve the light absorption in the ultraviolet wavelength region. However, ultraviolet absorbers have poor dispersibility in TEF polymers, and they tend to volatilize or decompose at the molding temperature of TEF polymers. Furthermore, when using ultraviolet absorbers, there is a tendency for the electrical properties of TEF polymers, such as electrical insulation, to decrease. [Prior Art Documents] [Patent Documents]

[0004] Patent Document 1: WO2019 / 087939 [Summary of the Invention]

[0005] [The problem the invention aims to solve]

[0006] These tendencies are more pronounced in tetrafluoroethylene-based polymers with particularly small relative permittivity and dielectric loss tangent and high fluorine content, making it difficult to obtain materials possessing both electrical properties and light absorption in the ultraviolet wavelength region. The inventors are aware of these problems. The inventors have studied combinations of tetrafluoroethylene-based polymers and organic ultraviolet absorbers, and discovered that by combining specific tetrafluoroethylene-based polymers with ultraviolet absorbers, the reduction in electrical properties is suppressed and the absorption rate of the tetrafluoroethylene-based polymer in the ultraviolet wavelength region is improved, thereby achieving the present invention. [Technical Means for Solving the Problem]

[0007] The present invention has the following forms. [1] A composition comprising: particles of a tetrafluoroethylene polymer having a fluorine content of 70% by mass or more, and an ultraviolet absorber having a nitrogen-containing heterocyclic structure and hydroxyl groups and a molecular weight of 250 or more. [2] The composition of [1] wherein the mass ratio of the content of the ultraviolet absorber to the content of the tetrafluoroethylene polymer is 0.001 to 0.1. [3] The composition of [1] or [2] is a liquid composition further comprising a liquid dispersion medium. [4] The composition of [3] wherein the content of the particles of the tetrafluoroethylene polymer is 30% by mass or more. [5] The composition of [3] or [4] wherein the ultraviolet absorber is contained in the composition in the form of particles. [6] The composition of [5] wherein the particles of the ultraviolet absorber are particles coated with a carbamate polymer.

[0008] [7] The composition of any one of [1] to [6] further contains an inorganic filler or a polymer other than the above-mentioned tetrafluoroethylene polymer. [8] The composition of any one of [1] to [7] wherein the above-mentioned tetrafluoroethylene polymer is a polymer having a melting temperature of 260 to 320°C. [9] The composition of any one of [1] to [8] wherein the above-mentioned tetrafluoroethylene polymer is a polymer containing a carbonyl group.

[10] The composition of [9] wherein the above-mentioned tetrafluoroethylene polymer is a polymer having 10 to 5000 carbonyl groups per 1×106 main chain carbons.

[11] The composition of any one of [1] to

[10] wherein the melting point of the above-mentioned ultraviolet absorber is 50 to 200°C.

[12] The composition of any one of [1] to

[11] wherein the hydroxyl group of the above-mentioned ultraviolet absorber is a phenolic hydroxyl group.

[13] The composition of any one of [1] to

[12] wherein the nitrogen-containing heterocyclic structure of the ultraviolet absorber is a triazine structure, a benzotriazole structure or a hydroxyphenyl triazine structure.

[0009]

[14] A laminate having at least one layer comprising a tetrafluoroethylene polymer having a carbonyl group and a fluorine content of 70% by mass or more, and an ultraviolet absorber having a nitrogen-containing heterocyclic structure and hydroxyl groups and a molecular weight of 250 or more, wherein the absorption rate of light with a wavelength of 255 to 355 nm per 1 μm thickness is 80% or more.

[15] A membrane comprising a tetrafluoroethylene polymer having a carbonyl group and a fluorine content of 70% by mass or more, and an ultraviolet absorber having a nitrogen-containing heterocyclic structure and hydroxyl groups and a molecular weight of 250 or more, wherein the absorption rate of light with a wavelength of 255 to 355 nm per 1 μm thickness is 80% or more. [Effects of the Invention]

[0010] According to the present invention, a composition comprising a tetrafluoroethylene-based polymer is provided, which can be used to form a molded article in which the reduction of electrical properties is suppressed and the light absorption rate in the ultraviolet wavelength region is improved. Furthermore, according to the present invention, a laminate having at least one layer comprising a tetrafluoroethylene-based polymer or a film comprising a tetrafluoroethylene-based polymer is provided. The laminate and film have high absorption rates in the ultraviolet wavelength region and excellent electrical properties, and are therefore suitable for use in printed wiring boards.

Implementation Method

[0011] The following terms have the following meanings: "Tetrafluoroethylene-based polymer" refers to a polymer containing units based on tetrafluoroethylene (hereinafter also referred to as TFE units). "Glass transition point (Tg) of the polymer" is a value determined by analyzing the polymer using dynamic viscoelasticity measurement (DMA). "Melting temperature (melting point) of the polymer" is the temperature corresponding to the maximum value of the melting peak measured by differential scanning calorimetry (DSC). "D50" is the average particle size of the target material (particles in a particle cluster), calculated as the cumulative diameter of the particle volume at 50% using laser diffraction. That is, it is the particle size at the point where the cumulative volume reaches 50% by determining the particle size distribution using laser diffraction, setting the total volume of the particle cluster to 100%, and obtaining a cumulative curve on the cumulative curve. "D90" refers to the cumulative volumetric particle size of the object, calculated using the same method as "D50" for the cumulative 90% diameter of the particle volume. "Viscosity" is the value obtained by measuring the liquid composition at room temperature (25°C) and a rotation speed of 30 rpm using a Type B viscometer. The measurement was repeated three times, and the average of the three measurements was taken. "Thixotropic ratio" is the value calculated by dividing the viscosity η1 obtained from the measurement of the liquid composition at 30 rpm by the viscosity η2 obtained from the measurement at 60 rpm (η1 / η2). In polymers, "monomer-based units" refer to atomic groups directly formed from a single monomer molecule through polymerization, and atomic groups formed by converting a portion of these atomic groups into other structures through processing the resulting polymer. Hereinafter, monomer-a-based units will also be abbreviated as "monomer a-units". "Dispersion layer ratio" is calculated by placing 18 mL of the liquid composition into a 30 mL spiral tube and allowing it to stand at 25°C for 14 days. The value is determined by the height of the overall composition and the height of the dispersion layer in the spiral tube after standing, using the following formula. Furthermore, if no dispersion layer is observed after standing and the state remains unchanged, it is considered that the overall height of the composition has not changed, and the dispersion layer ratio is considered 100%. A higher dispersion layer ratio indicates better dispersion stability. Dispersion layer ratio (%) = (height of dispersion layer) / (overall height of composition) × 100. "Foam volume ratio" is calculated by measuring the volume (VN) of the liquid composition at standard atmospheric pressure and 20°C, and the total volume (VV) of the foam when the pressure is reduced to 0.003 MPa, using the following formula. Foam volume ratio [%] = 100 × (VV - VN) / VN.

[0012] The composition of the present invention (hereinafter also referred to as "the composition") comprises particles of a tetrafluoroethylene polymer (hereinafter also referred to as "F polymer") having a fluorine content of 70% by mass or more, and an ultraviolet absorber having a nitrogen-containing heterocyclic structure and hydroxyl groups and a molecular weight of 250 or more (hereinafter also referred to as "the ultraviolet absorber"). Furthermore, the laminate of the present invention (hereinafter also referred to as "the laminate") is a laminate having at least one layer comprising a tetrafluoroethylene polymer having a carbonyl group and a fluorine content of 70% by mass or more, and an ultraviolet absorber having a nitrogen-containing heterocyclic structure and hydroxyl groups and a molecular weight of 250 or more, and having an absorption rate of 80% or more for light with a wavelength of 255 to 355 nm per 1 μm thickness (hereinafter also referred to as "the layer"). Furthermore, the membrane of the present invention (hereinafter also referred to as "the membrane") comprises a tetrafluoroethylene polymer having a carbonyl group and a fluorine content of 70% by mass or more, and an ultraviolet absorber having a nitrogen-containing heterocyclic structure and hydroxyl groups and a molecular weight of 250 or more, and a light absorption rate of 255 to 355 nm per 1 μm thickness of the membrane is 80% or more.

[0013] Tetrafluoroethylene polymers are highly rigid polymers with low surface energy, making their particles prone to aggregation and exhibiting poor affinity with other components such as UV absorbers. Therefore, organic UV absorbers, in particular, exhibit poor dispersibility in tetrafluoroethylene polymers and tend to volatilize or decompose at the molding temperature of the tetrafluoroethylene polymer. This tendency is especially pronounced in F polymers with higher fluorine content used in this composition. However, the inventors are aware that by combining a specific organic UV absorber with an F polymer, their affinity is improved, making it less likely for either the F polymer or the UV absorber to aggregate; and the UV absorber has a larger molecular weight, thus easily suppressing volatilization or decomposition of the F polymer at the melt molding temperature. As a result, the light absorption rate of the F polymer in the UV wavelength region can be improved without reducing the electrical properties of the F polymer.

[0014] Examples of this composition include: a powder composition comprising the particles of the polymer F and the particles of the ultraviolet absorber; a liquid composition comprising the polymer F, the ultraviolet absorber, and a liquid dispersion medium; a solid composition, such as a block or granular composition comprising the polymer F, the ultraviolet absorber, and a binder; etc. Furthermore, a liquid dispersion medium means a liquid medium in which the polymer F particles are at least not dissolved. The powder composition is preferably a powder composition used as a molding material or a coating material such as a powder coating. As a liquid composition, depending on the amount or properties of the liquid dispersion medium, examples include a liquid composition as a dispersion with relatively low viscosity, a liquid composition as a dispersion with relatively high viscosity such as a slurry or sol, etc. The liquid composition is preferably a liquid composition used as a coating material such as a paint. In the liquid composition, the ultraviolet absorber may be soluble in the liquid dispersion medium or may exist in the liquid dispersion medium in the form of particles that are not soluble in the liquid dispersion medium. Examples of particles insoluble in the liquid dispersion medium include: particles of the UV absorber itself insoluble in the liquid dispersion medium; particles of the UV absorber coated with a polymer insoluble in the liquid dispersion medium; and particles comprising a mixture of the UV absorber and a polymer insoluble in the liquid dispersion medium. Examples of solid compositions include: sol-like or clay-like solid compositions that contain a liquid medium but lack flowability; and solid compositions containing a thermoplastic polymer (wherein, it is a polymer other than F polymer) or a thermosetting resin or its cured form as a binder. The solid composition is preferably a solid composition used as a molding material. The aforementioned sol-like or clay-like solid compositions are also preferably used as precursors for adding a liquid dispersion medium to the aforementioned liquid composition.

[0015] The fluorine content of the F polymer is 70% by mass or more, preferably 76% by mass or less. More preferably, it is 74% by mass or more. For F polymers with higher fluorine content, the electrophysiological and other physical properties are excellent, but their polarity is relatively low, resulting in lower affinity for ultraviolet absorbers. However, by selecting specific ultraviolet absorbers, compositions with excellent dispersibility or uniformity can be obtained without compromising the physical properties of the F polymer.

[0016] Polymer F can be either thermoplastic or non-thermally plastic. Furthermore, thermoplastic and non-thermally plastic polymers can be used together. A thermoplastic polymer refers to a polymer that, under a load of 49 N, has a melt flow rate of 1–1000 g / 10 min at a temperature of [temperature value missing]. A non-thermally plastic polymer refers to a polymer that, under a load of 49 N, does not have a melt flow rate of 1–1000 g / 10 min at a temperature of [temperature value missing]. Polymer F is preferably thermoplastic. The melting temperature of the thermoplastic polymer F is preferably 260–320 °C, more preferably 285–320 °C. The glass transition point of polymer F is preferably 50 °C or higher, more preferably 75 °C or higher. The glass transition point of polymer F is preferably 125 °C or lower, more preferably 100 °C or lower.

[0017] The polymer F is preferably polytetrafluoroethylene (PTFE), a polymer containing TFE units and ethylene units, a polymer containing TFE units and propylene units, a polymer containing TFE units and units based on perfluoro(alkyl vinyl ether) (hereinafter also referred to as "PAVE units") (hereinafter also referred to as "PFA"), a polymer containing TFE units and fluoroalkyl vinyl units, a polymer containing TFE units and trifluorochloroethylene units, and a polymer containing TFE and hexafluoropropylene units (hereinafter also referred to as "FEP"), more preferably PFA and FEP, and even more preferably PFA. These polymers may further contain units based on other comonomers. PAVE is preferably CF2=CFOCF3, CF2=CFOCF2CF3 and CF2=CFOCF2CF2CF3 (hereinafter also referred to as "PPVE"), and even more preferably PPVE.

[0018] Polymer F preferably has polar functional groups. If polymer F has polar functional groups, the affinity between polymer F and the UV absorber increases, and the uniform dispersibility of the composition is easily increased. Furthermore, at the molding temperature of polymer F when forming the molded article from the composition, the volatilization or decomposition of the UV absorber is easily further suppressed. Polar functional groups are preferably hydroxyl-containing groups, carbonyl-containing groups, and phosphonic acid-containing groups. From the above point of view, hydroxyl-containing groups and carbonyl-containing groups are more preferred. From the point of view that the affinity between components is particularly easily increased due to the formation of hydrogen bonds, carbonyl-containing groups are even more preferred. Hydroxyl-containing groups are preferably alcohol-containing hydroxyl groups, and more preferably -CF2CH2OH, -C(CF3)2OH, and 1,2-ethylene glycol groups (-CH(OH)CH2OH).

[0019] The carbonyl group is preferably a carboxyl group, alkoxycarbonyl group, amide group, isocyanate group, carbamate group (-OC(O)NH2), anhydride residue (-C(O)OC(O)-), amide residue (-C(O)NHC(O)-, etc.), and carbonate group (-OC(O)O-), more preferably anhydride residue. When polymer F has a carbonyl group, the number of carbonyl groups in polymer F is preferably 10 to 5000 per 1×106 main chain carbons, more preferably 50 to 4000, and even more preferably 100 to 2000. In this case, polymer F readily interacts with the UV absorber, and the composition readily exhibits excellent processability and dispersion stability. Furthermore, the number of carbonyl groups in polymer F can be quantified by means of the polymer composition or by the method described in International Publication No. 2020 / 145133.

[0020] The polymer F is preferably a polymer with a melting temperature of 260 to 320°C, containing PAVE units, and more preferably a polymer having polar functional groups (hereinafter also referred to as "polymer (1)"). When the composition containing polymer (1) is processed into a molded article, microspheres are formed in the molded article, and thus the adhesion and other properties of the obtained molded article are easily improved.

[0021] The polar functional groups of polymer (1) may be contained in the monomer units contained in the polymer or in the terminal groups of the polymer backbone. Examples of polymers that are the latter include polymers with polar functional groups derived from polymerization initiators, chain transfer agents, etc. as terminal groups, or polymers with polar functional groups prepared by plasma treatment, offline treatment or radiation treatment. If polymer F is polymer (1), the polymer F particles are likely to have excellent affinity between polymer (1) and the UV absorber, and the composition is likely to have excellent processability or dispersion stability.

[0022] The polymer (1) preferably contains, with respect to all units, 93 to 98.99 mol% of TFE units, 1 to 5 mol% of PAVE units, and 0.01 to 2 mol% of units based on monomers having polar functional groups. Furthermore, the monomers having polar functional groups are preferably itanic anhydride, citrate anhydride, and 5-norphene-2,3-dicarboxylic anhydride (hereinafter also referred to as "NAH"). As a specific example of the polymer (1), the polymer described in International Publication No. 2018 / 16644 can be cited.

[0023] The present F polymer particles are particles containing F polymer, wherein the amount of F polymer in the particles is preferably 80% by mass or more, more preferably 100% by mass. The D50 of the present F polymer particles is preferably 20 μm or less, more preferably 8 μm or less, and even more preferably 5 μm or less. The D50 of the present F polymer particles is preferably 0.1 μm or more, more preferably 0.3 μm or more, and even more preferably 1 μm or more. Furthermore, the D90 of the present F polymer particles is preferably 10 μm or less, and even more preferably 5 μm or less. If the D50 and D90 of the present F polymer particles are within this range, their surface area increases, and the dispersibility of the present F polymer particles can be further improved. The specific surface area of ​​the present F polymer particles is preferably 1 to 25 m² / g.

[0024] The F polymer particles may also contain inorganic substances or polymers different from F polymers. Examples of inorganic substances are preferably oxides, nitrides, elemental metals, alloys, and carbon; more preferably, metal oxides such as silica, beryllium oxide, cerium oxide, aluminum oxide, alkali alumina, magnesium oxide, zinc oxide, and titanium oxide; boron nitride, bulk talc, and magnesium metasilicate; further preferably, silica and boron nitride; and most preferably, silica. The F polymer particles containing inorganic substances preferably have a core-shell structure with an F polymer core and an inorganic substance in the shell, or a core-shell structure with an F polymer shell and an inorganic substance in the core. The F polymer particles are obtained, for example, by combining F polymer particles with inorganic particles through collision or aggregation. Examples of polymers other than F polymers include aromatic polymers. Examples of aromatic polymers include aromatic elastomers of styrene elastomers, aromatic polyimides, aromatic maleimides, and aromatic polyamides.

[0025] This composition may also contain two or more types of this F polymer particles. In the case where two types of this F polymer particles are contained, the F polymer particles are preferably a combination of particles of a thermomeltable F polymer (particles of polymer (1), etc.) and particles of a non-thermally meltable F polymer (particles of non-thermally meltable PTFE, etc.). In this case, the uniform dispersion of this composition can be improved, and the physical properties such as electrical properties based on PTFE can be highly exhibited in the molded article obtained from this composition. Furthermore, the ratio of the former particles to the total amount of the two types of this F polymer particles is preferably 50% by mass or less, more preferably 25% by mass or less. Furthermore, the above ratio is preferably 0.1% by mass or more, more preferably 1% by mass or more. Furthermore, it is preferable that the D50 of the former particles is 1 to 4 μm, and the D50 of the latter particles is 0.1 to 1 μm.

[0026] This ultraviolet absorber has a nitrogen-containing heterocyclic structure and hydroxyl groups, and a molecular weight of 250 or more. This ultraviolet absorber can be contained in the composition in the form of particles, or, when the composition contains a liquid dispersion medium, it can be contained in the composition in a state of dissolution in a liquid dispersion medium. The nitrogen-containing heterocyclic structure is a structure in which nitrogen atoms are included as the constituent elements of the ring. Examples of rings include three-membered rings, four-membered rings, five-membered rings, and six-membered rings, preferably unsaturated rings. The number of nitrogen atoms as the constituent elements of the ring is at least 1, and usually less than 4. The constituent elements of the nitrogen-containing heterocyclic ring are usually nitrogen or carbon, but may also include elements other than nitrogen and carbon. The nitrogen-containing heterocyclic ring can be an aromatic heterocyclic ring or a non-aromatic heterocyclic ring, preferably an aromatic heterocyclic ring.

[0027] The hydroxyl group is preferably a phenolic hydroxyl group that bonds to an aromatic ring. The number of hydroxyl groups in this UV absorber is 1 or more, and usually 6 or less. In this case, the interaction between compounds caused by the formation of hydrogen bonds, etc., is enhanced, and the volatilization or decomposition of this UV absorber is easily further suppressed at the molding temperature of the F polymer when the composition is formed into a molded article.

[0028] Examples of nitrogen-containing heterocyclic structures include acrylonitrile, diacylonitrile, acrylonitrile, diacylonitrile, pyrrole, imidazole, pyrazole, triazole, pyridine, diazonium, triazonium, and tetraazonium structures. Also, structures with a benzene ring condensed on these structures can be exemplified, such as indole, isoindole, benzimidazole, purine, benzotriazole, quinoline, isoquinoline, quinazoline, quinoline, alkanoline, and pteridine structures. Furthermore, structures with various substituents on these structures are also possible. From the viewpoint of ultraviolet absorption capacity, triazonium and benzotriazole structures are preferred among these structures.

[0029] Examples of structures containing phenolic hydroxyl groups include phenol, cresol, naphthol, catechol, resorcinol, pyrogallol, hexahydroxybenzene, hydroxybenzophenone, dihydroxybenzophenone, and tetrahydroxybenzophenone, as well as structures with various substituents. Among these structures, phenol is preferred from the viewpoint of ultraviolet absorption capacity.

[0030] This ultraviolet absorber has both the aforementioned nitrogen-containing heterocyclic structure and the aforementioned structure containing hydroxyl groups. These nitrogen-containing heterocyclic structures and hydroxyl-containing structures may further have other substituents. This ultraviolet absorber preferably has a triazine structure or a benzotriazole structure, and a phenol structure. When it has a triazine structure and a phenol structure, this ultraviolet absorber is preferably a structure in which various substituents are substituted onto the hydroxyphenyl triazine structure or the hydroxyphenyl structure.

[0031] The molecular weight of this ultraviolet absorber is 250 or more, preferably 300 or more, and even more preferably 400 or more. Having this molecular weight suppresses the volatilization or decomposition of the F polymer at the molding temperature. For example, when a polymer layer (hereinafter also referred to as the "F layer") containing the F polymer and this ultraviolet absorber is formed by the method described below, the ultraviolet absorber can be present in the F layer. As a result, the light absorption rate in the ultraviolet wavelength region of the obtained molded article becomes higher. The molecular weight of this ultraviolet absorber is typically 1000 or less.

[0032] The melting point of this ultraviolet absorber is preferably 50–200°C, more preferably 60–180°C. When the melting point is within this range, it inhibits the volatilization or decomposition of the F polymer at the molding temperature, and the ultraviolet absorber can be present in the F layer when the F layer is formed. As a result, the light absorption rate in the ultraviolet wavelength region of the obtained molded article becomes higher.

[0033] The thermal decomposition temperature of this ultraviolet absorber is preferably 250°C or higher, more preferably 300°C or higher, and even more preferably 350°C or higher. The thermal decomposition temperature is preferably 400°C or lower. When the thermal decomposition temperature is within this range, the decomposition of the F polymer at the molding temperature is suppressed, and the ultraviolet absorber can be present in the F layer when it is formed. As a result, the light absorption rate in the ultraviolet wavelength region of the obtained molded article becomes higher. Furthermore, the thermal decomposition temperature of the ultraviolet absorber is determined when, under a nitrogen atmosphere, the ultraviolet absorber is heated from 50°C to 400°C at a rate of 10°C / min, and the mass becomes 95% of the initial mass at the start of the heating.

[0034] Commercially available examples of this UV absorber include: BASF's "Tinuvin 326" (molecular weight: 315.8; melting point: 139℃; Tinuvin is a registered trademark), "Tinuvin 405" (molecular weight: 583.8; melting point: 74-77℃), "Tinuvin 460" (molecular weight: 629.8; melting point: 93-102℃), "Tinuvin 900" (molecular weight: 447.6; melting point: 137-141℃), "Tinuvin 928" (molecular weight: 441.6; melting point: 109-113℃), Clariant's "Sanduvor VSU powder" (molecular weight: 312.0; melting point: 123-127℃), and Clariant's "Hastavin PR-25". Gran (molecular weight: 250.0; melting point: 55-59℃), Adekastab LA-F70 (molecular weight: 700; melting point: 144-150℃) manufactured by ADEKA, etc.

[0035] Regarding the mass ratio of the aforementioned polymer F to the aforementioned ultraviolet absorber in this composition, it is preferable that the mass of the polymer F is 1 and the mass of the ultraviolet absorber is 0.001 to 0.1. As the lower limit of the mass ratio of the polymer F to the ultraviolet absorber, from the viewpoint of the dispersion stability and light absorption rate in the ultraviolet wavelength region of the obtained composition, it is more preferably 0.01. Furthermore, from the same viewpoint, the upper limit of the above mass ratio is preferably 0.05, and more preferably 0.03. Through the above-described mechanism of action, the molded article formed from this composition readily exhibits excellent ultraviolet absorption capacity.

[0036] In this composition, from the viewpoint of further improving the light absorption rate in the ultraviolet wavelength region, it can also be used in combination with an ultraviolet absorber different from the present ultraviolet absorber. The ultraviolet absorber different from the present ultraviolet absorber is an ultraviolet absorber that does not have any of the aforementioned nitrogen-containing heterocycles or hydroxyl groups, and can be any of inorganic ultraviolet absorbers or organic ultraviolet absorbers. Examples of such different ultraviolet absorbers include, for example, benzophenone-based ultraviolet absorbers, triazole-based ultraviolet absorbers, triterpenoid-based ultraviolet absorbers, benzoic acid ester-based ultraviolet absorbers, and cyanoacrylate-based ultraviolet absorbers. These ultraviolet absorbers can also be in polymer form. Furthermore, they can also contain hindered amine light stabilizers (HALS), contain antioxidants, or contain both HALS and antioxidants.

[0037] This composition is preferably a liquid composition, in which case the composition contains a liquid dispersion medium. The liquid composition may also contain two or more liquid dispersion media; in this case, it is preferable that different types of liquid dispersion media are miscible. Furthermore, the liquid is a compound with a viscosity of 10 mPa·s or less at 25°C, and the same applies below. The boiling point of the liquid dispersion medium is preferably 125–250°C. For this composition containing a liquid dispersion medium having a boiling point within this range, when the composition is brought into contact with a substrate or the like, and the liquid dispersion medium is removed, the polymer particles of this composition flow highly and easily accumulate densely. As a result, a dense molded article can be easily formed from this composition.

[0038] The liquid dispersion medium is a liquid that functions to disperse the polymer particles and to disperse or dissolve the ultraviolet absorber, and is an inert liquid compound at 25°C. The composition having the liquid dispersion medium is a composition containing the polymer particles, the ultraviolet absorber, and the liquid dispersion medium in a liquid state. Normally, the polymer particles are dispersed in the liquid dispersion medium. From the viewpoint of affinity for the ultraviolet absorber having hydroxyl groups as polar functional groups, a polar solvent is preferred as the liquid dispersion medium. The polar solvent can be water or a non-aqueous solvent. Furthermore, the polar solvent can be an aprotic polar solvent or a protic solvent. Furthermore, a single polar solvent can be used, or, for example, two or more can be mixed and combined, such as in the combination of water and N-methyl-2-pyrrolidone. The preferred polar solvents are water, amides, ketones and esters, more preferably water, N-methyl-2-pyrrolidone, γ-butyrolactone, methyl ethyl ketone, cyclohexanone and cyclopentanone, and even more preferably N-methyl-2-pyrrolidone.

[0039] Furthermore, when the composition contains a liquid dispersion medium, the content of the polymer particles in the composition is preferably 30% by mass or more, more preferably 40% by mass or more. The aforementioned content is preferably 60% by mass or less, more preferably 50% by mass or less. In this case, the composition readily exhibits excellent dispersibility, and it is easy to obtain molded articles with excellent electrical properties and smoothness from the composition. Furthermore, in this case, the content of the ultraviolet absorber in the composition is preferably 0.1% by mass or more, more preferably 1% by mass or more. The aforementioned content is preferably 10% by mass or less, more preferably 3% by mass or less.

[0040] Furthermore, when the composition contains the aforementioned liquid dispersion medium, the solid content refers to the total amount of substances forming solid components in the molded article formed from the composition (excluding components other than the liquid dispersion medium). If the total mass of the composition containing the aforementioned liquid dispersion medium is set to 100%, the solid content concentration is preferably 20% by mass or more, more preferably 30% by mass or more. Also, from the viewpoint of the dispersibility of the composition, the solid content concentration is preferably 70% by mass or less, more preferably 60% by mass or less. Regarding the amount of the polymer particles in the solid content, if the total mass of the solid content is set to 100% by mass, it is preferably 50% by mass or more, more preferably 70% by mass or more. The above amounts are preferably less than 100% by mass.

[0041] When the composition is a liquid composition, the ultraviolet absorber in the composition is preferably contained in the composition in the form of particles. In this case, the particles of the ultraviolet absorber are preferably compounds that are insoluble in the liquid dispersion medium and are present in the liquid dispersion medium, or, regardless of their solubility, they are present in the liquid dispersion medium as particles whose surface is coated with a polymer or the like that that is insoluble in the liquid dispersion medium. In the latter case, the particles may also be a mixture of the ultraviolet absorber and a binder containing a polymer or the like that that is insoluble in the liquid dispersion medium. The polymer that is insoluble in the liquid dispersion medium and serves as the polymer coating the surface of the ultraviolet absorber particles or as the binder of the ultraviolet absorber is a polymer other than polymer F, such as thermoplastic polymers, cured resins, polymers that become cured by crosslinking, or oligomers. Specifically, examples include: urethane polymers, acrylate polymers, methacrylate polymers, and polyester polymers. Preferably, these polymers are urethane polymers, acrylate polymers, and methacrylate polymers, and more preferably urethane polymers. The particles containing this UV absorber preferably have a D50 of 20–100 nm and a D90 of 100–300 nm. The content of this UV absorber in the particles containing both the UV absorber and the aforementioned polymers is preferably 10–90% by mass, and more preferably 40–80% by mass. By including this UV absorber in the form of particles in the liquid composition, the composition exhibits excellent uniform dispersibility, and the light absorption rate in the UV wavelength region of the molded article obtained from this composition is easily increased.

[0042] Preferably, the particles of this ultraviolet absorber are coated with a carbamate polymer. Examples of the form of the ultraviolet absorber coated with a carbamate polymer include: particles comprising a mixture of particles of the ultraviolet absorber encapsulated in a carbamate polymer, and particles whose surface is covered with a carbamate polymer (core-shell particles with the ultraviolet absorber as the core and a carbamate polymer as the shell). When the composition is a liquid composition containing a liquid dispersion medium, especially when the composition is a liquid composition containing water, the ultraviolet absorber particles coated with a carbamate polymer not only disperse well in the liquid, but also stabilize the polymer particles and easily improve the rheology of the composition.

[0043] Examples of urethane polymers include: reaction products of polyisocyanates and polyols; reaction products of polyisocyanates, polyols and chain extenders; and reaction products of polyisocyanates, polyols, compounds having active hydrogen groups and hydrophilic groups, and chain extenders.

[0044] Examples of polyisocyanates include hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and 3,3'-dimethyl-4,4'-dicyclohexylmethane diisocyanate. Polyols are preferably polyether polyols or polycarbonate polyols. Examples of polyether polyols include ring-opening addition polymers of ethylene oxide, propylene oxide, butane oxide, and tetrahydrofuran. Examples of polycarbonate polyols include reactants of diols such as 1,4-butanediol, 1,6-hexanediol, and diethylene glycol with diphenyl carbonate or phosgene.

[0045] Examples of active hydrogen groups include hydroxyl, mercapto, and amino groups; examples of hydrophilic groups include carboxyl, sulfonic acid, and polyoxyalkylene groups. Examples of compounds having both active hydrogen and hydrophilic groups include 2,2-dimethylolpropionic acid, 2-hydroxyethanesulfonic acid, and polyethylene glycol. Examples of chain elongating agents include glycols such as ethylene glycol; polyhydroxy compounds such as glycerol and trimethylolethane; and polyamines such as ethylenediamine and 1,6-hexamethylenediamine. The urethane-based polymers are preferably polycarbonate-modified urethane-based polymers or ether-modified urethane-based polymers. These modified polymers are urethane-based polymers obtained using polycarbonate polyols or polyether polyols as polyols.

[0046] As a method for obtaining the ultraviolet absorber coated with a carbamate polymer, an example is to add the ultraviolet absorber to a solution formed by dissolving a reactant of a polyol and a polyisocyanate in an organic solvent, and then emulsify the reactant in water. When the reactant of the polyol and the polyisocyanate is an isocyanate-terminated prepolymer, a diamine may be added as a chain extender as needed to form an aqueous dispersion of the ultraviolet absorber coated with a carbamate polymer. As a more specific method, the following method can be exemplified: when using a urethane prepolymer with isocyanate groups at the molecular ends, the urethane prepolymer is a reactant of a polyol, a polyisocyanate, and a compound having active hydrogen and carboxyl groups. The UV absorber, a neutralizing agent such as triethylamine, and water are sequentially added to a solution in which the prepolymer is dissolved in an organic solvent. Then, a diamine is added as a chain elongating agent to form a urethane polymer. The organic solvent is then removed by distillation to obtain an aqueous dispersion containing the UV absorber coated by the urethane polymer.

[0047] Two or more types of this ultraviolet absorber may also be used. When two or more types of this ultraviolet absorber are used, it is preferable to use two or more types of this ultraviolet absorber having a tri-triple structure, and more preferably to use two or more types of this ultraviolet absorber coated with a urethane polymer and having a tri-triple structure.

[0048] This composition may also contain inorganic fillers, polymers other than polymer F, or curable oligomers other than polymer F (hereinafter also referred to as "other polymers") as needed. Furthermore, the liquid form of this composition may also be a surfactant.

[0049] When the purpose of the inorganic filler is to improve the dielectric constant of the molded article, it is preferable to use inorganic fillers such as perovskite-type strong dielectric fillers or bismuth layered perovskite-type strong dielectric fillers. Examples of perovskite-type strong dielectrics include barium titanate, lead zirconate titanate, lead titanate, zirconium oxide, and titanium oxide. On the other hand, examples of bismuth layered perovskite-type strong dielectrics include bismuth strontium tantalate, bismuth strontium niobate, and bismuth titanate.

[0050] Furthermore, for example, when the purpose is to reduce the dielectric constant and dielectric loss tangent, or the linear expansion rate, of the molded article, an inorganic filler with a low dielectric constant and low dielectric loss tangent, or a low linear expansion rate, is used. The inorganic filler is preferably boron nitride filler, beryllium oxide filler, silica filler, wollastonite filler, or magnesium metasilicate filler (block talc filler).

[0051] Furthermore, for example, when the purpose is to improve the thermal conductivity or scratch resistance of the molded article, a metal oxide filler is used. The metal oxide is preferably aluminum oxide, lead oxide, iron oxide, tin oxide, magnesium oxide, titanium oxide, zinc oxide, antimony pentoxide, zirconium oxide, lanthanum oxide, neodymium oxide, cerium oxide and niobium oxide, and more preferably aluminum oxide.

[0052] Furthermore, inorganic fillers other than those mentioned above may also be used, such as glass fiber fillers and carbon fillers. Examples of carbon fillers include: carbon fiber, carbon black, graphene, graphene oxide, fullerene, graphite, and graphite oxide. Examples of carbon fibers include: polyacrylonitrile-based carbon fibers, pitch-based carbon fibers, vapor-grown carbon fibers, and carbon nanotubes (single-walled, double-walled, multi-walled, stacked cup type, etc.).

[0053] The shape of the aforementioned inorganic filler is appropriately selected according to the purpose, and can be either granular or fibrous. Granular inorganic fillers can be flake-shaped or spherical. In the case of granular inorganic fillers, the average particle size (D50) is preferably 0.02–200 μm. In the case of fibrous inorganic fillers, the average fiber length is preferably 0.05–300 μm. The average fiber diameter of fibrous inorganic fillers is preferably 0.01–15 μm.

[0054] Regarding the aforementioned inorganic filler, from the viewpoint of the processability and dispersibility of this composition, at least a portion of its surface can also be surface-treated by a silane coupling agent. Specific examples of silane coupling agents include: 3-aminopropyltriethoxysilane, vinyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-isocyanopropyltriethoxysilane.

[0055] Suitable specific examples of inorganic fillers include: silica fillers (Admatechs' "Admafine" series, etc.), zinc oxide surface-treated with esters such as propylene glycol didecanoate (Sakai Chemical Industry Co., Ltd.'s "FINEX" series, etc.), spherical molten silica (DENKA's "SFP" series, etc.), coated with polyols and inorganic substances (Ishihara Sangyo Co., Ltd.'s "Tipaque" series, etc.), rutile titanium dioxide surface-treated with alkyl silanes (Tayca's "JMT" series, etc.), hollow silica fillers (Pacific Cement Corporation's "E-SPHERES" series, Nippon Steel Mining Co., Ltd.'s "SiliNax" series, Emerson & Cuming's "Ecco sphere" series, etc.), talc fillers (NIPPON). The composition includes inorganic fillers such as the "SG" series manufactured by TALC Corporation, block talc fillers (such as the "BST" series manufactured by NIPPON TALC Corporation), and boron nitride fillers (such as the "UHP" series manufactured by Showa Denko Corporation, the "HGP" series manufactured by DENKA Corporation, and the "GP" series manufactured by DENKA Corporation). When the composition contains the above-mentioned inorganic fillers, the ratio of the polymer particles to the inorganic fillers is preferably a ratio where the mass of the polymer particles is 1 and the mass of the inorganic fillers is 0.5 to 2.

[0056] The above-mentioned other polymers are polymers that do not contain TFE units and tetrafluoroethylene-based polymers that contain TFE units and have a fluorine content of less than 70% by mass. Examples of other polymers include: thermoplastic polymers, thermoplastic elastomers, thermosetting polymers, or oligomers. Specifically, examples include: aromatic polyesters, aromatic polyimides, aromatic polyamides, aromatic polyamides, the above-mentioned urethane polymers, aliphatic polyamides, polyphenylene ether, polyphenylene oxide, liquid crystal polyesters, polysaccharides, aliphatic polyamides, polyacrylates, polymethacrylates, polyvinyl butyral, ABR rubber, cellulose, and fluorinated polymers other than F polymers.

[0057] Other polymers are preferably aromatic polyesters, aromatic polyimides, aromatic polyamides, aromatic polyamide-imides, and polyphenylene ethers. Aromatic polyimides can be thermoplastic or thermosetting. Specific examples of aromatic polyimides include: the "Neopulim" series (manufactured by Mitsubishi Gas Chemical Co., Ltd.), the "SPIXAREA" series (manufactured by SOMAR Corporation), the "Q-PILON" series (manufactured by PI Technology Research Institute), the "WINGO" series (manufactured by Wingo Technology Co., Ltd.), the "TOHMIDE" series (manufactured by T&K TOKA Co., Ltd.), the "KPI-MX" series (manufactured by Kawamura Sangyo Co., Ltd.), the "UPIA-AT" series (manufactured by Ube Industries Co., Ltd.), "HPC-1000", and "HPC-2100D" (all manufactured by Showa Denko Materials Co., Ltd.). Examples of fluorinated polymers other than F-polymers include: polyvinylidene fluoride, polyvinylidene fluoride, and polytrifluoroethylene chloride.

[0058] Furthermore, other polymers are preferably nonionic polysaccharides. Examples of nonionic polysaccharides include: glycogen, amylose, agarose, amylopectin, cellulose, dextrin, dextran, fructan, and chitin. Cellulose is preferably carboxymethyl cellulose or hydroxyethyl cellulose. Specific examples of nonionic polysaccharides include: the "SUNROSE" series (manufactured by Nippon Paper Co., Ltd.), the "Metolose" series (manufactured by Shin-Etsu Chemical Co., Ltd.), and "HEC CF Grade" (manufactured by Sumitomo Chemical Co., Ltd.). When this composition contains nonionic polysaccharides, the composition tends to exhibit excellent uniform dispersibility and processability, and the molded articles obtained from this composition tend to exhibit excellent electrical properties.

[0059] This composition may also contain two or more other polymers. The combination of other polymers is preferably a combination of aromatic polymers and nonionic polysaccharides. When this composition contains the aforementioned other polymers, the mass ratio of the polymer particles to the other polymers is preferably a ratio of 1 for the mass of the polymer particles and 0.01 to 0.5 for the mass of the other polymers, more preferably a ratio of 0.03 to 0.3.

[0060] From the viewpoint of improving dispersion stability and processability, this composition, especially the composition containing a liquid dispersion medium, may further contain a nonionic surfactant. The hydrophilic portion of the surfactant preferably has a polyoxyethylene chain or an alcoholic hydroxyl group. The polyoxyethylene chain may consist solely of oxyethyl groups, or it may contain oxyethyl groups and other oxyalkyl groups. In the latter case, the oxyethyl groups and other oxyalkyl groups may be arranged randomly or in a block configuration.

[0061] The hydrophobic portion of the surfactant preferably has an acetylene group, a polysiloxane group, a perfluoroalkyl group, or a perfluoroolefin group. In other words, the surfactant is preferably an acetylene-based surfactant, a silicone-based surfactant, or a fluorine-based surfactant, and more preferably a silicone-based surfactant. Specific examples of this surfactant include: the "FTERGENT" series (manufactured by NEOS Co., Ltd., FTERGENT is a registered trademark), the "Surflon" series (manufactured by AGC Seimei Chemical Co., Ltd., Surflon is a registered trademark), the "MEGAFAC" series (manufactured by DIC Co., Ltd., MEGAFAC is a registered trademark), the "Unidyne" series (manufactured by Daikin Industries, Ltd., Unidyne is a registered trademark), "BYK-347", "BYK-349", "BYK-378", "BYK-3450", "BYK-3451", "BYK-3455", "BYK-3456" (manufactured by BYK-Chemie Japan Co., Ltd.), "KF-6011", and "KF-6043" (manufactured by Shin-Etsu Chemical Co., Ltd.). When the composition contains surfactants, the surfactant content is preferably 1-15% by mass, more preferably 1-5% by mass. In this case, the affinity between components increases, and the dispersion stability of the composition is more easily improved. Furthermore, the residual amount of surfactant in the molded article formed from this composition can be reduced, making it easier to improve the electrical properties of the molded article.

[0062] The viscosity of the liquid composition is preferably 10 mPa·s or more, more preferably 100 mPa·s or more. The viscosity of the liquid composition is preferably 10000 mPa·s or less, more preferably 1000 mPa·s or less. In this case, the liquid composition has excellent coatability, and therefore it is easy to form molded articles such as F polymer layers of arbitrary thickness from the liquid composition. The thixotropic ratio of the liquid composition is preferably 1 or more. The thixotropic ratio of the composition is preferably 3 or less, more preferably 2 or less. In this case, the liquid composition not only has excellent coatability, but also excellent homogeneity, and therefore it is easy to form molded articles such as denser F polymer layers.

[0063] The dispersion ratio of the liquid composition is preferably 60% or more, more preferably 70% or more. The upper limit of the dispersion ratio is 100%. The liquid composition has excellent dispersibility, so it is easy to adjust to this dispersion ratio.

[0064] From the viewpoint of suppressing the reduction of uniformity of component distribution or voids in the molded article obtained from the liquid composition, the foam volume ratio in the liquid composition is preferably less than 10%, more preferably less than 5%. The foam volume ratio is preferably greater than 0%.

[0065] In addition to the above-mentioned components, this composition may also contain thixotropic agents, viscosity modifiers, defoamers, silane coupling agents, dehydrating agents, plasticizers, weathering agents, antioxidants, heat stabilizers, lubricants, antistatic agents, whitening agents, colorants, conductive agents, release agents, surface treatment agents, flame retardants, various fillers and other components.

[0066] This composition is obtained by mixing the above-mentioned polymer particles, the ultraviolet absorber, the above-mentioned inorganic filler as needed, the above-mentioned other polymers, liquid dispersion medium, surfactant and other components.

[0067] When adding the aforementioned inorganic filler, other polymers, or other components, they can be added when mixing the aforementioned polymer particles with the aforementioned UV absorber; alternatively, the inorganic filler, other polymers, or other components can be mixed with the UV absorber beforehand, and then the polymer particles can be added thereto; alternatively, the polymer particles can be mixed with the inorganic filler, other polymers, or other components beforehand, and then the UV absorber can be added thereto. When adding inorganic fillers, other polymers, and other components, they can be added separately; they can be added together; or they can be mixed beforehand to prepare a masterbatch, and then the masterbatch can be added.

[0068] Furthermore, when the composition contains the aforementioned liquid dispersion medium, the polymer particles and the ultraviolet absorber can be added to the liquid dispersion medium; alternatively, the polymer particles can be mixed with the liquid dispersion medium, and then the ultraviolet absorber can be added thereto; alternatively, the ultraviolet absorber can be mixed with the liquid dispersion medium, and then the polymer particles can be added thereto. When mixing the polymer particles, the ultraviolet absorber, and the liquid dispersion medium, degassing can be performed while mixing. Furthermore, after mixing the polymer particles, the ultraviolet absorber, and the liquid dispersion medium, the mixture can be left to stand for a period of time. The addition of the aforementioned inorganic filler, other polymers, other components, or liquid dispersion medium can be carried out continuously or intermittently.

[0069] As a suitable form in which the composition includes water as a liquid dispersion medium, it may also include a form that further includes a nonionic surfactant, or a form in which the UV absorber is coated with an acrylate polymer. In this case, the nonionic surfactant can be the same as the nonionic surfactant described above. As the UV absorber in this case, a UV absorber coated with an acrylate polymer and having a benzotriazole structure or a hydroxyphenyltriazine structure may be cited as an example, and more suitable is a UV absorber coated with an acrylate polymer and having a hydroxyphenyltriazine structure. Specific examples of such UV absorbers include: "UC-3140" manufactured by ADEKA, "Tinuvin 479-DW(N)" (Tinuvin is a registered trademark) manufactured by BASF, and "Tinuvin 477-DW(N)". The composition is preferably prepared by mixing a composition comprising the present F polymer particles, a nonionic surfactant and water with a composition comprising the present ultraviolet absorber, a nonionic surfactant and water.

[0070] The present composition, excluding the aforementioned liquid dispersion medium, is typically in the form of a powder or granules, or other solid form. The solid form of the present composition may also be a compound obtained by melt-blending the aforementioned F polymer particles with the aforementioned ultraviolet absorber, the aforementioned inorganic filler added as needed, other polymers, or other components. If this compound is melt-formed, a film or other molded product containing the aforementioned F polymer and the aforementioned ultraviolet absorber can be obtained. Examples of melt-forming include extrusion molding and injection molding, with extrusion molding being preferred. Extrusion molding can be performed using a single-screw extruder, a multi-screw extruder, or the like. Melt-blending can be performed within the aforementioned extruder, and film can be directly extruded without removal; alternatively, the present composition can be pre-melted to form granules, which can then be used for extrusion molding, injection molding, etc.

[0071] The film obtained by the above melt forming can be used alone or laminated with other films or substrates to form a laminate. Examples of methods for manufacturing the laminate include: using a co-extruder as the extruder to extrude the composition together with the raw material of the substrate; extruding the composition onto the substrate; and hot-pressing the extruded part of the composition to the substrate.

[0072] When the composition contains a liquid dispersion medium, contacting the composition with a substrate or the like, followed by drying and firing, can form a laminate having an F layer and a substrate. Suitable forms of such a laminate include a metal foil laminate having a metal foil and an F layer formed on at least one surface thereon, and a multilayer film having a resin film (especially a polyimide film) and an F layer formed on at least one surface thereon. Furthermore, the substrate can be removed from the metal foil laminate or multilayer film by etching or dissolving, or the F layer can be peeled off from the substrate to form a film with a single F layer.

[0073] In the manufacture of the above-mentioned laminate, it is sufficient to form an F layer on at least one side of the substrate surface. The F layer may be formed only on one side of the substrate or on both sides of the substrate. The surface of the substrate may also be surface treated with a silane coupling agent or the like. When in contact with the liquid composition, coating methods such as spraying, roller coating, spin coating, gravure coating, microgravure coating, gravure offset coating, blade coating, contact coating, bar coating, die coating, injection Müller bar coating, and slot die coating can be used.

[0074] Preferably, layer F is formed by heating the F polymer after removing the liquid dispersion medium by heating. The removal temperature of the liquid dispersion medium is preferably 50-150°C lower than the boiling point of the liquid dispersion medium. For example, when using N-methyl-2-pyrrolidone with a boiling point of approximately 200°C, heating is preferably performed at 100-120°C, below 150°C. It is also preferable to blow air during the step of removing the liquid dispersion medium.

[0075] Preferably, after removing the dispersion medium, the substrate is heated to the temperature range for firing the F polymer to form the F layer, and preferably the polymer is fired in a range of, for example, 300 to 400°C. The F layer is preferably a fired product containing the F polymer. The F layer is formed as described above by contacting, drying, and firing the composition containing the liquid dispersion medium. These steps may be performed once or more. For example, the composition described above is coated, and the liquid dispersion medium is removed by heating to form a film. Alternatively, the liquid composition described above may be coated onto the formed film, the liquid dispersion medium may be removed by heating, and then the polymer may be fired by heating to form the film. From the viewpoint of easily obtaining a thick film with excellent smoothness, it is preferable to perform the coating, drying, and firing steps of the composition twice.

[0076] The thickness of the F layer is preferably 0.1 μm or more, more preferably 1 μm or more. The upper limit of the thickness is 200 μm. Within this range, an F layer with excellent crack resistance can be easily formed. The peel strength between the F layer and the substrate layer is preferably 10 N / cm or more, more preferably 15 N / cm or more. The above peel strength is preferably 100 N / cm or less. If this composition is used, the laminate can be easily formed without impairing the physical properties of the F polymer in the F layer. The porosity of the F layer is preferably 5% or less, more preferably 4% or less. The porosity is preferably 0.01% or more, more preferably 0.1% or more. Furthermore, the porosity is determined by image processing of an SEM image of the cross-section of the molded article observed using a scanning electron microscope (SEM), and the ratio (%) is obtained by dividing the area occupied by the porosity portion of the F layer by the area of ​​the F layer. The area occupied by the gap is calculated by approximating the gap as a circle.

[0077] Examples of substrate materials include metal substrates such as metal foils made of copper, nickel, aluminum, titanium, and their alloys; and resin films such as polyimide, polyarylate, polyurethane, polyarylurethane, polyamide, polyetheramide, polyphenylene sulfide, polyaryletherketone, polyamideimide, liquid crystal polyester, and liquid crystal polyesteramide, which serve as prepregs for fiber-reinforced resin substrates. Examples of substrate shapes include planar, curved, and uneven surfaces, and further, foil, plate, film, and fibrous forms. Specific examples of laminates include metal foil laminates having a metal foil and an F layer on at least one surface of the metal foil, and multilayer films having a polyimide film and F layers on both surfaces of the polyimide film. These laminates exhibit excellent electrical properties and other physical properties, making them suitable as printing substrate materials. Specifically, this laminate can be used to manufacture flexible printed circuit boards or rigid printed circuit boards.

[0078] Examples of a laminate consisting of the F layer and other substrates include metal substrate / F layer / other substrate layer / F layer / metal substrate, metal substrate layer / other substrate layer / F layer / other substrate layer / metal substrate layer, etc. Each layer may further include glass cloth or filler.

[0079] The laminated system of the present invention comprises at least one layer (this layer) containing an F polymer having a carbonyl group and the present ultraviolet absorber, and having an absorption rate of 80% or more for light with a wavelength of 255-355 nm per 1 μm thickness. In other words, it is a laminated body having a layer with a higher light absorption rate in the ultraviolet region of 255-355 nm. Furthermore, the light absorption rate for light with a wavelength of 255-355 nm per 1 μm thickness is determined by measuring the light absorption rate of this layer using a commercially available spectrophotometer and converting the thickness to 1 μm.

[0080] The light absorption rate is preferably 85% or more, more preferably 90% or more. The upper limit of the light absorption rate is 100%. The definition and scope of the F polymer containing a carbonyl group and the ultraviolet absorber, as well as their suitable forms, are the same as those in the above-described composition. Furthermore, this layer may further include inorganic fillers, other polymers, and other components. The definition and scope of the inorganic fillers, other polymers, and other components, as well as their suitable forms, are the same as those in the above-described composition. As a layer included in this laminate that is different from this layer, examples of substrates that can be used when obtaining a laminate from the above-described composition can be cited. The thickness of this layer is preferably 0.1 μm or more, more preferably 1 μm or more. The upper limit of the thickness is 200 μm.

[0081] This laminate can be formed, for example, from a composition comprising an F polymer having a carbonyl group. An example of such a method is the aforementioned method for obtaining a laminate from this composition. By using the aforementioned suitable compound as the F polymer having a carbonyl group and the aforementioned ultraviolet absorber, and ensuring that their amounts are within the aforementioned suitable range, the light absorption rate at wavelengths of 255–355 nm per 1 μm thickness of the laminate can be 80% or more, more preferably 90% or more. The layer exhibits a high absorption rate in the ultraviolet wavelength region while maintaining the electrical properties and other physical properties of the F polymer.

[0082] This membrane comprises an F polymer having a carbonyl group and the ultraviolet absorber, and has an absorption rate of 80% or more for light with a wavelength of 255-355 nm per 1 μm thickness. Furthermore, the light absorption rate is measured by the same method as described above. The light absorption rate of this membrane with a wavelength of 255-355 nm per 1 μm thickness is preferably 85% or more, more preferably 90% or more. The upper limit of the light absorption rate is 100%. The definition and scope of the F polymer having a carbonyl group and the ultraviolet absorber, as well as their suitable forms, are the same as those in the above-described composition. Furthermore, this membrane may also further comprise inorganic fillers, other polymers, and other components. The definition and scope of the inorganic fillers, other polymers, and other components, as well as their suitable forms, are the same as those in the above-described composition.

[0083] The thickness of this film is preferably 0.1 μm or more, more preferably 1 μm or more. The upper limit of the thickness is 200 μm. This film is obtained, for example, by extruding a compound that is obtained by melt-mixing a composition containing an F polymer having a carbonyl group and being in powder or granular form. Alternatively, this film can be obtained by removing a layer different from this layer from the laminate. By using the above-mentioned suitable compound as the F polymer having a carbonyl group and the ultraviolet absorber, and ensuring that their amounts are within the above-mentioned suitable range, the absorption rate of light with a wavelength of 255–355 nm per 1 μm thickness of this film can be 80% or more, more preferably 90% or more.

[0084] This laminate and this film can be used as antenna parts, printed circuit boards, aircraft parts, automotive parts, sporting goods, food industry supplies, coatings, cosmetics, protective films, heat dissipation substrates, heat dissipation parts, etc. Specifically, it can be used as a coating material for electrical wires (such as aircraft wires), electrical insulation tape, insulating tape for oil excavation, material for printed circuit boards, separation membranes (microfiltration membranes, ultrafiltration membranes, reverse osmosis membranes, ion exchange membranes, dialysis membranes, gas separation membranes, etc.), electrode adhesives (for lithium secondary batteries, fuel cells, etc.), replica rollers, outer covers for furniture, automotive dashboards, and home appliances, sliding components (load bearings, sliding shafts, valves, bearings, gears, cams, belt conveyors, food conveyor belts, etc.), tools (shovels, files, awls, saws, etc.), boilers, hoppers, pipes, ovens, baking molds, chutes, molds, toilets, container coating materials, heat dissipation substrates for automobiles, and heat sinks or heat plates for electronic devices (power devices, transistors, thyristors, rectifiers, transformers, power MOS (metal oxide semiconductor), FET (field effect transistor), CPU (central processing unit), etc.). More specifically, it can be used as a casing for computers or monitors, material for electronic devices, interior and exterior parts of automobiles, sealing material for processing machines or vacuum ovens that undergo heat treatment under low oxygen conditions, plasma treatment devices, etc., or heat dissipation parts in processing units such as sputtering or various dry etching devices.

[0085] As described above, the composition comprising polymer F and this ultraviolet absorber exhibits excellent dispersibility of the ultraviolet absorber, allowing the formation of molded articles with high light absorption in the ultraviolet wavelength region without impairing the electrical properties and other physical properties inherent in polymer F. Furthermore, this laminate and this film exhibit high absorption in the ultraviolet wavelength region without impairing the electrical properties and other physical properties inherent in polymer F. Therefore, it has excellent UV processability and can be used in printed wiring boards, etc.

[0086] The present composition, the laminate, and the film have been described above, but the present invention is not limited to the configuration of the above embodiments. For example, other arbitrary configurations may be added to the present composition, the laminate, and the film in the configuration of the above embodiments, or they may be replaced with any configuration that performs the same function. [Example]

[0087] Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited to these examples. 1. Preparation of each component [powder] Powder 1: An aggregate of particles (D50: 2.0 μm) comprising the following polymer (fluorine content: 76 wt%), the polymer comprising 97.9 mol% TFE units, 0.1 mol% NAH units and 2.0 mol% PPVE units, and having 1000 carbonyl groups per 1×106 main chain carbons. Powder 2: An aggregate of particles (D50: 2.4 μm) comprising the following polymer (fluorine content: 76 wt%), the polymer comprising TFE units and PPVE units, and having 40 carbonyl groups per 1×106 main chain carbons.

[0088] [UV Absorbers] UVA1: Hydroxyphenyl triterpenoid UV absorber (molecular weight ≥ 250, melting point 68-102℃, BASF Japan's "Tinuvin 479") UVA2: Hydroxyphenyl triterpenoid UV absorber (molecular weight ≥ 250, melting point 106-108℃, ADEKA's "LA-46") ​​UVA3: Hydroxybenzotriazole UV absorber (molecular weight ≥ 250, melting point 161-166℃, Shipro Kasei's "SEESORB 706") UVA4: 2-(2-hydroxy-5-methylphenyl)benzotriazole (molecular weight 225, melting point 129-133℃) UVA5: Particles of hydroxyphenyl triterpenoid UV absorber coated with acrylate polymers (molecular weight ≥ 250, melting point 68-102℃, BASF Japan's "Tinuvin") 479-DW(N)”. Furthermore, the content of the above-mentioned hydroxyphenyltriazole UV absorber in the particles is 80% by mass or more. UVA6: Benzotriazole UV absorber with phenolic hydroxyl groups (molecular weight ≥ 250, melting point 50-200℃, "UC-3140" manufactured by ADEKA). UVA7: Particles of hydroxyphenyltriazole UV absorber coated with acrylate polymers (molecular weight ≥ 250, melting point 50-200℃, "Tinuvin 477-DW(N)" manufactured by BASF Japan). Furthermore, the content of the above-mentioned hydroxyphenyltriazole UV absorber in the particles is 80% by mass or more. UVA8: Hydroxyphenyltriazole UV absorber (molecular weight ≥ 250, melting point 144-150℃, D50: 54 nm; D90: 213 nm; "Adekastab" manufactured by ADEKA). LA-F70) UVA9: Triglyceride UV absorber without hydroxyl groups [UV absorber dispersion] UVA dispersion 1: Contains UVA8 and UVA9, which are coated with carbonate-modified urethane polymers and dispersed in water in an aqueous dispersion [liquid dispersion medium] NMP: N-methyl-2-pyrrolidone [surfactant] Surfactant 1: A copolymer of CH2=C(CH3)C(O)OCH2CH2(CF2)6F and CH2=C(CH3)C(O)(OCH2CH2)23OH, a nonionic polymer with a fluorine content of 35% by mass. Surfactant 2: Silicone surfactant (BYK-3450 manufactured by BYK-Chemie Japan) [Other polymers] HEC1: Hydroxyethyl cellulose (HEC CF-Y manufactured by Sumitomo Chemical Co., Ltd.) [Varnishes of other polymers] Varnish 1: Aqueous varnish containing aromatic polyamide imide (PAI1) precursors.

[0089] 2. Example of Dispersion Preparation (Example 1) First, powder 1, surfactant 1, and NMP are added to a crucible, followed by zirconia balls. Then, the crucible is rotated at 150 rpm for 1 hour to prepare composition 11. UVA1 and NMP are added to another crucible, followed by zirconia balls. Then, the crucible is rotated at 150 rpm for 1 hour to prepare composition 12. Composition 11 and composition 12 are added to yet another crucible, followed by zirconia balls. Then, the crucible is rotated at 150 rpm for 1 hour to obtain a dispersion 1 containing 100 parts by mass of powder 1 particles, 2 parts by mass of UVA1, 10 parts by mass of surfactant 1, and 128 parts by mass of NMP, with a viscosity of 400 mPa·s.

[0090] (Examples 2-8) Except for changing the types of powder, ultraviolet absorber, surfactant and liquid dispersion medium as shown in Table 1 below, dispersions 2-8 were obtained in the same manner as in Example 1.

[0091] (Example 9) First, powder 1, surfactant 1, varnish 1, HEC 1, and water are added to a crucible, and zirconia balls are added. Then, the crucible is rotated at 150 rpm for 1 hour to prepare composition 91. Composition 91 and UVA dispersion 1 are added to another crucible, and zirconia balls are added. Then, the crucible is rotated at 150 rpm for 1 hour to obtain a dispersion 9 containing particles of powder 1 (100 parts by mass), UVA8 (0.25 parts by mass), UVA9 (0.25 parts by mass), PAI 1 (0.8 parts by mass), HEC 1 (0.5 parts by mass), surfactant 1 (3.5 parts by mass), and water (104 parts by mass), where UVA8 and UVA9 are particles coated with urethane polymers, and the dispersion has a viscosity of 150 mPa·s.

[0092] (Example 10) First, powder 1, surfactant 1, HEC 1, varnish 1, and water are added to a crucible, followed by zirconia balls. Then, the crucible is rotated at 150 rpm for 1 hour to prepare composition 101. In another crucible, UVA 8, UVA 9, and water are added, followed by zirconia balls. Then, the crucible is rotated at 150 rpm for 1 hour to adjust composition 102. In yet another crucible, compositions 101 and 102 are added, followed by zirconia balls. Subsequently, the crucible was rotated at 150 rpm for 1 hour to obtain a dispersion 10 containing particles 1 (100 parts by mass), UVA8 (0.25 parts by mass), UVA9 (0.25 parts by mass), PAI1 (0.8 parts by mass), HEC1 (0.5 parts by mass), surfactant 1 (3.5 parts by mass), and water (104 parts by mass). UVA8 and UVA9 are particles not coated with urethane polymers and have a viscosity of 300 mPa·s.

[0093] The types and amounts of components contained in each dispersion, and whether the UVA contained in each dispersion is coated with a carbamate polymer, are summarized in Table 1 below. [Table 1] Dispersion number Powder types UVA types Is UVA coated with carbamate? Types of surfactants Other resins Liquid dispersion medium 1 1(100) 1(2) none 1(10) - NMP(128) 2 1(100) 2(2) none 1(10) - NMP(128) 3 1(100) 3(2) none 1(10) - NMP(128) 4 2(100) 1(2) none 1(10) - NMP(128) 5 1(100) 4(2) none 1(10) - NMP(128) 6 1(100) 5(2) none 1(10) - Water (128) 7 1(100) 6(2) none 1(10) - Water (128) 8 1(100) 7(2) none 2(10) - Water (128) 9 1(100) 8 (0.25) 9 (0.25) have 2(3.5) PAI(0.8) HEC(0.5) Water (104) 10 1(100) 8 (0.25) 9 (0.25) none 2(3.5) PAI(0.8) HEC(0.5) Water (104) ※The numbers in parentheses in each ingredient column indicate the content (parts by mass).

[0094] 3. Example of manufacturing the laminate and film: A bar coater is used to coat the dispersion 1 onto the surface of a strip of copper foil with a thickness of 18 μm to form a wet film. Then, the metal foil with the wet film is passed through a drying oven at 120°C for 5 minutes to dry it by heating, thereby obtaining a dry film. Subsequently, the dry film is heated at 380°C for 3 minutes in a nitrogen oven. This produces a laminate 1 having a metal foil and a polymer layer with a thickness of 5 μm containing molten sintered powder 1 and UVA1 on its surface. The copper foil of the laminate 1 is removed by etching in a ferric chloride aqueous solution to manufacture film 1. Laminates 2-8 and films 2-8 are manufactured in the same manner as film 1, except that dispersions 2-8 are used instead of dispersion 1. Furthermore, by changing the coating conditions in the manufacturing of membrane 1, a polymer layer with a thickness of 25 μm is manufactured from dispersion 9 to form a laminate 9, from which membrane 9 is obtained. In the same manner, laminate 10 and membrane 10 are obtained from dispersion 10.

[0095] 4. Evaluation 4-1. Evaluation of Dispersions 4-1-1. Dispersion Stability After storing dispersions 1 to 10 in containers at 25°C, their dispersibility is confirmed visually, and the dispersion stability is evaluated according to the following criteria. [Evaluation Criteria] 〇: No visible agglomerates. △: Fine agglomerates are visible adhering to the container sidewall. After gentle stirring, they redisperse evenly, and no agglomerates are visible. ×: Fine agglomerates are visible adhering to the container sidewall. Fine agglomerates are also visible adhering to the container sidewall after gentle stirring.

[0096] 4-2. Evaluation of the membrane 4-2-1. Dielectric loss tangent of the membrane For membranes 1 to 10, the dielectric loss tangent of the membrane was measured by SPDR (Split Post Dielectric Resonation) method (measurement frequency: 10 GHz). The dielectric loss tangent of the membrane was evaluated according to the following criteria. [Evaluation Criteria] 〇: Dielectric loss tangent is less than 0.0010. △: Dielectric loss tangent is more than 0.0010 and less than 0.0025. ×: Dielectric loss tangent exceeds 0.0025.

[0097] 4-2-2. Light Absorption Rate of the Membrane For membranes 1 to 10, the absorption rate of ultraviolet light at a wavelength of 355 nm was measured using a spectrophotometer (manufactured by Shimadzu Corporation, "UV-3600"), and the ultraviolet absorption rate per 1 μm thickness of the membrane was calculated. The light transmittance of the membrane was evaluated according to the following criteria. [Evaluation Criteria] 〇: Light absorption rate is 90% or higher. △: Light absorption rate is 80% or higher but less than 90%. ×: Light absorption rate is less than 80%. The evaluation results are summarized in Table 2 below.

[0098] [Table 2] Dispersion or membrane number Evaluation of dispersion Membrane evaluation Dispersion stability Dielectric loss tangent Light absorption rate 1 〇 〇 〇 2 〇 〇 〇 3 〇 〇 〇 4 × △ △ 5 〇 × × 6 〇 〇 〇 7 〇 〇 〇 8 〇 〇 〇 9 〇 〇 〇 10 △ 〇 △

[0099] Furthermore, even when using dispersions 6 to 10 and a polyimide film in a roll-to-roll process involving coating and heating to manufacture a laminate of a polyimide film having a layer containing powder 1 (melted sintered material) and UVA on its surface, it is possible to efficiently and continuously produce laminates formed from the dispersion that exhibit no visible cracks and excellent UV absorption. [Industrial Applicability]

[0100] As can be seen from the above results, the dispersion stability of this composition is excellent. Furthermore, the laminate and the film exhibit excellent ultraviolet absorption capabilities without any reduction in the inherent physical properties of tetrafluoroethylene-based polymers. Moreover, the entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2020-195004, filed November 25, 2020, are incorporated herein by reference as a disclosure of this invention.

Claims

1. A composition comprising: particles of a tetrafluoroethylene-based polymer having a fluorine content of 70% to 76% by mass and a melting temperature of 260 to 320°C; and an ultraviolet absorber having a nitrogen-containing heterocyclic structure and hydroxyl groups and a molecular weight of 250 to 1000, wherein the mass ratio of the ultraviolet absorber to the tetrafluoroethylene-based polymer is 0.001 to 0.05, the tetrafluoroethylene-based polymer having carbonyl groups and the number of carbonyl groups being 50 to 4000 per 1×10⁶ main chain carbons, and the composition being used as a printed circuit board material.

2. The composition of claim 1, which further comprises a liquid composition containing a liquid dispersion medium.

3. The composition of claim 2, wherein the content of the above-mentioned tetrafluoroethylene polymer particles is 30% by mass or more.

4. The composition of claim 2 or 3, wherein the ultraviolet absorber is contained in the composition in the form of particles.

5. The composition of claim 4, wherein the particles of the ultraviolet absorber are particles coated with a urethane polymer.

6. The composition of any one of claims 1 to 3 further contains an inorganic filler or a polymer other than the aforementioned tetrafluoroethylene polymers.

7. The composition of any one of claims 1 to 3, wherein the melting point of the ultraviolet absorber is 50 to 200°C.

8. The composition of any one of claims 1 to 3, wherein the hydroxyl group of the ultraviolet absorber is a phenolic hydroxyl group.

9. The composition of any one of claims 1 to 3, wherein the nitrogen-containing heterocyclic structure of the ultraviolet absorber is a triazine structure, a benzotriazole structure, or a hydroxyphenyl triazine structure.

10. A laminate comprising at least one layer as follows: a tetrafluoroethylene polymer having a carbonyl group and a fluorine content of 70% to 76% by mass and a melting temperature of 260 to 320°C; and an ultraviolet absorber having a nitrogen-containing heterocyclic structure and hydroxyl groups and a molecular weight of 250 to 1000, wherein the mass ratio of the ultraviolet absorber to the tetrafluoroethylene polymer is 0.001 to 0.05, the tetrafluoroethylene polymer having a carbonyl group having a number of carbonyl groups of 50 to 4000 per 1×10⁶ main chain carbons, and an absorption rate of 80% or more for light with a wavelength of 255 to 355 nm per 1 μm thickness, and the laminate being used as a printed circuit board material.

11. A membrane comprising a tetrafluoroethylene-based polymer having a carbonyl group and a fluorine content of 70% to 76% by mass and a melting temperature of 260 to 320°C, and an ultraviolet absorber having a nitrogen-containing heterocyclic structure and hydroxyl groups and a molecular weight of 250 to 1000, wherein the mass ratio of the ultraviolet absorber to the tetrafluoroethylene-based polymer is 0.001 to 0.05, the tetrafluoroethylene-based polymer having a carbonyl group and the number of carbonyl groups being 50 to 4000 per 1×10⁶ main chain carbons, the membrane having a light absorption rate of 80% or more at a wavelength of 255 to 355 nm per 1 μm thickness, and the membrane being used as a printed circuit board material.