CN115210300A

CN115210300A - Composite particle, method for producing composite particle, liquid composition, method for producing laminate, and method for producing film

Info

Publication number: CN115210300A
Application number: CN202180018381.4A
Authority: CN
Inventors: 光永敦美; 细田朋也; 笠井涉
Original assignee: Asahi Glass Co Ltd
Current assignee: AGC Inc
Priority date: 2020-03-25
Filing date: 2021-03-22
Publication date: 2022-10-18
Also published as: TW202200703A; JP7511117B2; KR20220158736A; JPWO2021193505A1; WO2021193505A1

Abstract

The present invention addresses the problem of providing composite particles that contain an arbitrary amount of inorganic substances and have desired physical properties such as high polarity. The composite particles of the present invention comprise at least 1 kind of tetrafluoroethylene polymer having a melting temperature of 260 to 320 ℃ and an inorganic substance, wherein the tetrafluoroethylene polymer is selected from the group consisting of a tetrafluoroethylene polymer having a polar functional group and a tetrafluoroethylene polymer having a perfluoro (alkyl vinyl ether) -based unit, and a tetrafluoroethylene polymer having no polar functional group and containing 2.0 to 5.0 mol% of a perfluoro (alkyl vinyl ether) -based unit with respect to the total units.

Description

Composite particle, method for producing composite particle, liquid composition, method for producing laminate, and method for producing film

Technical Field

The present invention relates to composite particles containing a predetermined tetrafluoroethylene polymer and an inorganic substance, a method for producing the same, a liquid composition using the composite particles, a method for producing a laminate, and a method for producing a film.

Background

Patent documents 1 and 2 disclose composite particles of silica and a tetrafluoroethylene polymer. However, the tetrafluoroethylene polymer has extremely low polarity and low affinity with other components, and therefore, it hardly interacts with silica to a high degree. Therefore, it is difficult to incorporate a sufficient amount of silica into the composite particles of the above documents.

In addition, the composite particles of the above documents have low interaction between silica and a tetrafluoroethylene polymer, and therefore, stability of the composite particles itself is not sufficient, and silica is easily detached from the composite particles. Therefore, the interaction between silica and the tetrafluoroethylene polymer must be ensured, and the selection range of silica (the amount of hydroxyl groups of silica, etc.) is easily limited.

Further, due to this limitation, the use form of the composite particles of the above documents is also limited. For example, it is difficult to improve the affinity of the composite particles for a liquid medium, and it is difficult to ensure the dispersion stability because foaming is severe when a liquid composition in which the composite particles are dispersed is prepared.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2016-124729

Patent document 2: international publication No. 2018/212279

Disclosure of Invention

Technical problems to be solved by the invention

The present inventors have conducted extensive studies and found that the above-mentioned problems can be solved by using a predetermined tetrafluoroethylene polymer, and have completed the present invention.

The purpose of the present invention is to provide composite particles which contain an arbitrary amount of inorganic substances and have desired physical properties such as high polarity.

Technical scheme for solving technical problem

[ claim 1] composite particles comprising at least 1 kind of tetrafluoroethylene polymer having a melting temperature of 260 to 320 ℃ and an inorganic substance, wherein the tetrafluoroethylene polymer is selected from the group consisting of a tetrafluoroethylene polymer having a polar functional group and containing a perfluoro (alkyl vinyl ether) -based unit, and a tetrafluoroethylene polymer having no polar functional group and containing 2.0 to 5.0 mol% of a perfluoro (alkyl vinyl ether) -based unit with respect to the total units.

<2> the composite particle according to <1>, wherein a powder kinetic friction angle of the composite particle is 40 degrees or less.

<3> the composite particle according to <1> or <2> above, wherein the inorganic substance is silicon dioxide or boron nitride.

<4> the composite particles according to the above <1> to <3>, wherein the composite particles are spherical or scaly.

<5> the composite particle according to any one of <1> to <4> above, wherein the tetrafluoroethylene polymer is used as a core, and the inorganic substance is provided on the surface of the core.

<6> the composite particle according to <5>, wherein the tetrafluoroethylene polymer core and the inorganic material are in the form of particles, and the average particle diameter of the core is larger than the average particle diameter of the inorganic material.

<7> the composite particle as stated in any one of above <5> or <6>, wherein a ratio of a fluorine element content to an inorganic element content on a surface of the composite particle measured by energy dispersive X-ray spectrometry is less than 1.

<8> the composite particle according to any one of above <1> to <4>, wherein the inorganic substance is a core, and the tetrafluoroethylene polymer is provided on a surface of the core.

<9> the composite particle according to <8> above, wherein the mass of the inorganic substance in the composite particle is larger than the mass of the tetrafluoroethylene polymer.

<10> a method for producing the composite particles according to any one of <1> to <9>, wherein the particles of the tetrafluoroethylene polymer and the particles of the inorganic substance are caused to collide with each other at a temperature equal to or higher than a melting temperature of the tetrafluoroethylene polymer and in a floating state, thereby obtaining the composite particles.

<11> a method for producing the composite particles according to any one of <1> to <9>, wherein the particles of the tetrafluoroethylene polymer and the particles of the inorganic substance are caused to collide with each other in a pressed or sheared state to obtain the composite particles.

<12> a liquid composition comprising the composite particles according to any one of <1> to <9> and a liquid dispersion medium, wherein the composite particles are dispersed in the liquid dispersion medium.

<13> the liquid composition as stated in above <12>, wherein said liquid dispersion medium is at least 1 liquid compound selected from the group consisting of water, amide, ketone and ester.

<14> a method for producing a laminate, wherein the liquid composition <12> or <13> is applied to the surface of a base material layer, and heated to form a polymer layer, thereby obtaining a laminate comprising the base material layer and the polymer layer.

<15> a method for producing a film, which comprises melt-kneading the composite particles of any one of <1> to <9> and a fluoroolefin polymer, and then extruding the mixture to obtain a film.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, composite particles containing an arbitrary amount of inorganic substances and having desired physical properties such as high polarity can be obtained. Further, according to the present invention, a liquid composition containing composite particles and having good dispersion stability, and a laminate and a film highly having good properties (electrical properties, low linear expansion properties, and the like) based on a tetrafluoroethylene polymer and an inorganic substance can be obtained.

Detailed Description

The "average particle diameter (D50)" means a cumulative 50% diameter on a volume basis of an object (particle) determined by a laser diffraction/scattering method. That is, the particle size distribution of the object is measured by a laser diffraction/scattering method, and a cumulative curve is obtained with the total volume of the population of object particles as 100%, and the particle size of a point on the cumulative curve where the cumulative volume reaches 50% is obtained.

"D90" is a cumulative 90% diameter of the object measured in the same manner on a volume basis.

The "powder kinetic friction angle" is a value obtained by measuring an object according to the measurement method defined in JIS Z8835.

The "melting temperature (melting point)" is a temperature corresponding to the maximum value of the melting peak of the polymer measured by Differential Scanning Calorimetry (DSC).

"glass transition temperature (Tg)" means a value measured by analyzing a polymer by a dynamic viscoelasticity measurement (DMA) method.

The "viscosity" is a value obtained by measuring a liquid composition at 25 ℃ and 30rpm using a B-type viscometer. The measurement was repeated 3 times, and the average value of the measured values of 3 times was taken.

"thixotropic ratio" means the viscosity eta obtained by measuring a liquid composition at a rotation speed of 30rpm ₁ Divided by the viscosity eta obtained by measuring the liquid composition at a rotation speed of 60rpm ₂ And the calculated value (η) ₁ /η ₂ )。

The "unit" in the polymer may be a radical formed directly from a monomer or a radical obtained by treating the obtained polymer by a predetermined method to convert a part of the structure. The units based on monomer A contained in the polymer are also referred to simply as "monomer A units".

The composite particles of the present invention (hereinafter also referred to as "the present particles") are particles containing a tetrafluoroethylene polymer having a melting temperature of 260 to 320 ℃ and an inorganic substance.

The tetrafluoroethylene polymer (hereinafter also referred to as "F polymer") is at least 1 selected from the group consisting of a polymer (1) having a polar functional group containing a unit (PAVE unit) based on perfluoro (alkyl vinyl ether) (PAVE) and a polymer (2) having no polar functional group containing 2.0 to 5.0 mol% of the PAVE unit based on the whole units.

The particles are a composite material of an F polymer and an inorganic substance, which can contain an arbitrary amount of the inorganic substance and can adjust physical properties such as polarity to a desired state, and which has high stability. The mechanism of action is not clearly understood, but is presumed as follows.

The F polymer is excellent in shape stability such as fibril resistance and has a high-degree-of-freedom conformation in which the restriction of molecular motion at the monomolecular level is alleviated. The F polymer is likely to form fine spherulites at the level of molecular aggregates, and the surface thereof is likely to have a fine uneven structure. Therefore, it is considered that the molecular aggregate of the F polymer (single particles of the F polymer, etc.) can be stably physically and tightly adhered to the inorganic substance without damaging the shape thereof. Further, it is considered that the interaction between the inorganic substances that are closely adhered further promotes the adhesion of the inorganic substances to stabilize the composite particles.

As a result, the present particles contain an arbitrary amount of inorganic substances, in other words, a large amount of inorganic substances, have high stability, and have the physical properties of the F polymer and the physical properties of the inorganic substances at a high level.

The F polymer in the present particle is a polymer containing TFE units and PAVE units.

As PAVE, CF is preferred ₂ ＝CFOCF ₃ 、CF ₂ ＝CFOCF ₂ CF ₃ And CF ₂ ＝CFOCF ₂ CF ₂ CF ₃ (PPVE), more preferably PPVE.

The melting temperature of the F polymer is between 260 and 320 ℃, preferably between 285 and 320 ℃.

The glass transition temperature of the F polymer is preferably from 75 to 125 ℃ and more preferably from 80 to 100 ℃.

The melt viscosity of the F polymer is preferably 1X 10 at 380 ℃ ² ～1×10 ⁶ Pa · s, more preferably 1X 10 ³ ～1×10 ⁶ Pa·s。

If the melting temperature, glass transition temperature and melt viscosity of the F polymer are within these ranges, the above-mentioned mechanism of action tends to be enhanced.

The polar functional group of the polymer (1) may be contained in a unit contained in the polymer or may be contained in a terminal group of the polymer main chain. The latter polymer may, for example, be a polymer having a polar functional group as an end group derived from a polymerization initiator, a chain transfer agent or the like, or a polymer having a polar functional group obtained by plasma treatment or ionizing radiation treatment.

If the polymer F is the polymer (1), the polymer (1) and the inorganic substance in the present particle are easily attached not only physically but also chemically, and the above mechanism of action is easily enhanced.

The polar functional group is preferably a hydroxyl-containing group, a carbonyl-containing group or a phosphono-containing group, and from the viewpoint of easily improving physical properties such as dispersibility of the present particles, the hydroxyl-containing group and the carbonyl-containing group are preferred, and the carbonyl-containing group is more preferred.

As the hydroxyl group-containing group, a group containing an alcoholic hydroxyl group is preferable, and-CF is more preferable ₂ CH ₂ OH、-C(CF ₃ ) ₂ OH and 1, 2-ethanediol (-CH (OH) CH) ₂ OH)。

As the carbonyl group-containing group, preferred are a carboxyl group, an alkoxycarbonyl group, an amide group, an isocyanate group, and a carbamate group (-OC (O) NH) ₂ ) Acid anhydride residue (-C (O) OC (O) -) imide residues (-C (O) NHC (O) -, etc.) or carbonate groups (-OC (O) O-), anhydride residues are more preferred.

When the polymer (1) has a carbonyl group, the number of carbonyl groups in the polymer (1) is 1X 10 carbon atoms per main chain ⁶ The number of the cells is preferably 500 to 5000, more preferably 600 to 3000, and still more preferably 800 to 1500. The number of carbonyl-containing groups in the polymer (1) can be determined by the composition of the polymer or by the method described in International publication No. 2020/145133. In this case, the polymer (1) has a high chemical interaction with the inorganic substance, and the inorganic substance is likely to adhere to the surface of the molecular assembly of the polymer (1) not only physically but also chemically.

The polymer (1) preferably contains, based on the total of the units, 90 to 99 mol% of a TFE unit, 0.5 to 9.97 mol% of a PAVE unit, and 0.01 to 3 mol% of a unit based on a monomer having a polar functional group.

As the monomer having a polar functional group, itaconic anhydride, citraconic anhydride, or 5-norbornene-2, 3-dicarboxylic anhydride (hereinafter, also referred to as "NAH") is preferable, and NAH is more preferable.

Specific examples of the polymer (1) include polymers described in International publication No. 2018/16644.

The polymer (2) is preferably composed of only TFE units and PAVE units, and contains 95.0 to 98.0 mol% of TFE units and 2.0 to 5.0 mol% of PAVE units relative to the whole units.

The content of PAVE units in the polymer (2) is preferably 2.1 mol% or more, more preferably 2.2 mol% or more, relative to the total units.

The degree of freedom of molecular conformation of the polymer is higher, and the above action mechanism is easy to improve.

The polymer (2) having no polar functional group means that the ratio is 1X 10 ⁶ The number of carbon atoms constituting the main chain of the polymer is less than 500, and the number of polar functional groups of the polymer is less than 500. The above-mentioned poleThe number of functional groups is preferably 100 or less, more preferably less than 50. The lower limit of the number of the polar functional groups is usually 0.

The polymer (2) may be produced by using a polymerization initiator or a chain transfer agent which does not generate a polar functional group as an end group of a polymer chain, or may be produced by subjecting a polymer having a polar functional group (e.g., a polymer having a polar functional group derived from a polymerization initiator in an end group of a polymer chain) to a fluorination treatment.

As a method of the fluorination treatment, a method using a fluorine gas is exemplified (see Japanese patent laid-open publication No. 2019-194314).

The particles may contain other polymers besides the F polymer. The proportion of the F polymer in the polymer contained in the present particle is preferably 80% by mass or more, more preferably 100% by mass.

Examples of the polymer other than the polymer F include heat-resistant resins such as aromatic polyesters, polyamide imides, thermoplastic polyimides, polyphenylene ethers and the like.

The inorganic substance in the present particle is preferably an oxide, a nitride, a simple metal, an alloy, and carbon, more preferably silica (silica), a metal oxide (beryllium oxide, cerium oxide, aluminum oxide, basic aluminum oxide, magnesium oxide, zinc oxide, titanium oxide, or the like), boron nitride, and magnesium metasilicate (talc), further preferably an inorganic oxide containing at least 1 element selected from aluminum, magnesium, silicon, titanium, and zinc, talc, and boron nitride, particularly preferably silica and boron nitride, and most preferably silica. The inorganic substance may be ceramic. The inorganic substances may be used in a mixture of 1 or more than 2. When 2 or more kinds of inorganic substances are mixed, 2 kinds of silica may be used, and silica and metal oxide may be used.

The inorganic material is easy to improve the interaction with the F polymer, and the particle can contain more inorganic material. In addition, physical properties based on inorganic substances in a molded article (for example, a polymer layer and a film described later) formed from the present particles are likely to be remarkably exhibited.

The inorganic substance in the present particle preferably contains silica.

The content of silica in the inorganic substance is preferably 50 mass% or more, and more preferably 75 mass% or more. The upper limit of the silica content is 100 mass%.

Preferably, at least a part of the surface of the inorganic substance is surface-treated.

Examples of the surface treatment agent used for the surface treatment include: polyhydric alcohols (trimethylolethane, pentaerythritol, propylene glycol, etc.), saturated fatty acids (stearic acid, lauric acid, etc.), esters thereof, alkanolamines, amines (trimethylamine, triethylamine, etc.), paraffins, silane coupling agents, silicones, polysiloxanes, oxides of aluminum, silicon, zirconium, tin, titanium, antimony, etc., hydroxides thereof, hydrated oxides thereof, phosphates thereof.

As the silane coupling agent, 3-aminopropyltriethoxysilane, vinyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane or 3-isocyanatopropyltriethoxysilane are preferable.

The specific surface area (BET method) of the inorganic substance is preferably 1 to 20m ² A ratio of each gram, more preferably 5 to 8m ² (ii) in terms of/g. In this case, the interaction between the inorganic substance and the F polymer is easily promoted. In addition, the inorganic substance and the F polymer are more uniformly distributed in the molded product (polymer layer or the like), and the physical properties of both are more easily balanced.

Examples of inorganic materials include silica fillers (made by Yadouma corporation (1245089124831246312473) "the" admafin (registered trademark) "series, made by Astro chemical industries, inc. (made by" FINEX (registered trademark) "series, made by SAKO K.K.) "electrochemical Boron Nitride (Denka Boron Nitride)" series (grade "GP", "HGP"), manufactured by Nippon electrochemical Co., ltd.).

The inorganic material is preferably in the form of particles, more preferably in the form of spheres, needles (fibers) or plates (columns). Specific shapes of the inorganic substance include spherical, scaly, lamellar, foliate, almond-shaped, columnar, crowned, equiaxial, foliate, mica-shaped, massive, flat, wedge-shaped, rosette-shaped, mesh-shaped, and square columnar shapes, and spherical and scaly shapes are preferable. When an inorganic material having such a shape is used, the uniformity of the distribution of the inorganic material in the molded product (polymer layer or the like) is improved, and the function thereof is easily improved. The inorganic substance is preferably spherical silica or scaly boron nitride.

The spherical inorganic material is preferably approximately spherical. The approximately spherical shape means that the ratio of the minor axis to the major axis of the spherical particles is 0.5 or more and the ratio of the spherical particles to the major axis of the spherical particles is 95% or more when the particles are observed by a Scanning Electron Microscope (SEM). In this case, the ratio of the minor axis to the major axis of the inorganic particles is preferably 0.5 or more, more preferably 0.8 or more, and the ratio of the minor axis to the major axis is preferably less than 1. When the highly spherical inorganic particles are used, the inorganic substance and the F polymer in the molded article (such as a polymer layer) are more uniformly distributed, and the physical properties of the two are more easily balanced.

When the inorganic substance is in the form of a scale, the inorganic substance in the molded product tends to form a channel, and the thermal conductivity of the molded product tends to be better.

The aspect ratio of the scaly inorganic substance is preferably 5 or more, more preferably 10 or more. The aspect ratio is preferably 1000 or less.

The average major axis (average of the longitudinal diameter) of the scaly inorganic substance is preferably 1 μm or more, more preferably 3 μm or more. The average major axis is preferably 20 μm or less, more preferably 10 μm or less. The average minor axis (average of the diameters in the short direction) is preferably 0.01 μm or more, more preferably 0.1 μm or more. The average minor axis is preferably 1 μm or less, more preferably 0.5 μm or less. In this case, the inorganic substance and the F polymer in the molded article (polymer layer and the like) are more uniformly distributed, and the physical properties of both are more easily balanced.

The scaly inorganic substance may have a single-layer structure or a multi-layer structure.

The latter inorganic substance may, for example, be an inorganic substance having a hydrophobic portion on the surface and a hydrophilic portion inside. Specific examples thereof include inorganic substances having a hydrophobic layer, a hydrophilic layer (aqueous layer), and a hydrophobic layer in this order. The water content of the hydrophilic layer is preferably 0.3 mass% or more. In this case, not only the dispersion state of the present particles in the liquid composition is easily stabilized, but also the orientation of the inorganic substance in the molded article (polymer layer or the like) is further improved, and a molded article (polymer layer or the like) highly having the physical properties of the F polymer and the inorganic substance is easily obtained.

The D50 of the present particles is preferably 40 μm or less, more preferably 10 μm or less, still more preferably 6 μm or less, and particularly preferably 4 μm or less. The D50 of the present particles is preferably 0.01 μm or more, more preferably 0.1 μm or more, and still more preferably 1 μm or more.

The D90 of the present particles is preferably 50 μm or less, more preferably 20 μm or less, and particularly preferably 10 μm or less.

When the D50 and D90 of the present particles are within the above range, the dispersion stability of the present particles in the liquid composition and the physical properties of a molded article (such as a polymer layer) obtained from the liquid composition can be improved more easily.

The powder kinetic friction angle of the present particles is preferably 40 degrees or less, more preferably 30 degrees or less, and still more preferably 20 degrees or less. The particle preferably has a kinetic friction angle of 5 degrees or more. In this case, the particles are less likely to aggregate, and the dispersion stability of the particles in the liquid composition is likely to be improved. In addition, the present particles can be easily dispersed in a liquid composition with less force. When the polymer F in the present particle is the polymer (1), the dynamic friction angle of the powder is easily developed.

The present particles are preferably produced by the following method: that is, the method of colliding the F polymer particles with the inorganic particles at a temperature equal to or higher than the melting temperature of the F polymer and in a floating state (hereinafter, also referred to as "dry method a"), the method of colliding the F polymer particles with the inorganic particles in a pressed or sheared state (hereinafter, also referred to as "dry method B"), and the method of solidifying the F polymer particles after contacting the F polymer particles with the inorganic particles in a liquid (hereinafter, also referred to as "wet method").

In the dry method a, for example, the F polymer particles and the inorganic particles are supplied in a high-temperature turbulent atmosphere, and the F polymer particles and the inorganic particles are combined by applying stress to the particles by collision. This dry method a is also sometimes referred to as a hybrid treatment.

The atmosphere is formed by a gas. Examples of the gas that can be used include air, oxygen, nitrogen, argon, and a mixed gas thereof.

The polymer particles and the inorganic particles may be supplied as a previously mixed mixture in an atmosphere at once, or may be supplied separately in an atmosphere.

When the polymer particles and the inorganic particles are supplied under a high-temperature atmosphere, the particles are preferably not aggregated with each other. As this method, a method of floating particles in a medium (gas or liquid) can be employed. Mixtures of gases and liquids may also be used as the medium.

In the dry method a, the polymer particles F and the inorganic particles may be supplied after the high-temperature turbulent atmosphere is prepared, or the medium may be heated after the polymer particles F and the inorganic particles are suspended in the medium to form the high-temperature turbulent atmosphere.

As an apparatus usable in the former case, there may be mentioned an apparatus (for example, an apparatus for mechanically manufacturing a "hybrid system" (manufactured by a nelamine mechanical manufacturing method) in which particles are stirred by a stirring body (for example, a stirring blade) rotating at a high speed in a cylindrical container and at the same time, stress is applied to hold the particles between an inner wall of the container and the stirring body.

The temperature of the atmosphere is preferably not lower than the melting temperature of the F polymer, more preferably 260 to 400 ℃, and further preferably 320 to 380 ℃.

In the case where the inorganic particles contain a large amount of aggregates formed by the aggregation of the primary particles, the aggregates may be broken up before being supplied to the high-temperature atmosphere.

Examples of the method for crushing the aggregates include a method using a jet mill, a pin mill, and a hammer mill.

In the dry method B, for example, the polymer particles and the inorganic particles are pressed against the inner peripheral surface (receiving surface) of a cylindrical rotating body rotating around the central axis by a centrifugal force, and the pressing force or the shearing force is applied to the particles by the synergistic action of the inner peripheral surface and an inner stator disposed at a minute distance from the inner peripheral surface, thereby combining the particles. This dry method B is also sometimes called mechanofusion treatment.

The atmosphere in the cylindrical rotating body may be an inert gas atmosphere or a reducing gas atmosphere. The temperature of the atmosphere is preferably below the melting temperature of the F polymer, more preferably below 100 ℃.

The distance between the inner peripheral surface of the cylindrical rotating body and the inner stator can be appropriately set according to the average particle diameters of the F polymer particles and the inorganic particles. The separation distance is preferably 1 to 10mm in general.

The rotational speed of the cylindrical rotating body is preferably 500 to 10000rpm. In this case, the production efficiency of the present particle is easily improved.

When the inorganic particles contain a large amount of aggregates formed by the aggregation of the primary particles, the aggregates may be crushed in the same manner as described in the above-mentioned dry method a before being supplied into the cylindrical rotating body.

The dry method B may be performed by using a pulverization mixing apparatus including a rotary tank having a pulverization mixing chamber with an elliptical (irregular) cross section in which a rotary shaft is arranged in a horizontal direction, and a pulverization mixing blade having an elliptical (irregular) cross section which is rotatably inserted into the pulverization mixing chamber of the rotary tank, the rotary shaft being arranged concentrically with the rotary shaft of the rotary tank.

In this pulverizing and mixing apparatus, the polymer particles and the inorganic particles are pressed between the short diameter portion of the pulverizing and mixing chamber and the long diameter portion of the pulverizing and mixing blade, and the particles are combined by applying a pressing force or a shearing force.

In the pulverizing and mixing device, the rotation direction of the rotary trough and the rotation direction of the pulverizing and mixing blade are preferably opposite to each other, and the rotation speed of the rotary trough is preferably set to be slower than the rotation speed of the pulverizing and mixing blade.

In the crushing and mixing device, the crushing and mixing chamber and the crushing and mixing blade have irregular cross sections, and instantaneous pressing force or shearing force can be repeatedly applied to the fluidized F polymer particles and inorganic particles falling down due to their own weight in the crushing and mixing chamber. Accordingly, the particles can be pulverized and mixed in a short time while reducing adverse effects of heat, and thus the particles having desired characteristics can be easily obtained.

In the wet method, for example, inorganic particles are added and mixed to a dispersion of F-containing polymer particles. Specifically, after the inorganic particles are dispersed in the liquid dispersion medium, they are added to and mixed with the dispersion of the F-containing polymer particles. The method facilitates mixing between the inorganic particles and the F polymer particles.

If the coagulation of the mixture of the F-containing polymer particles and the inorganic particles is initiated by destabilizing the mixture, the F-containing polymer particles and the inorganic particles can be complexed,

when the inorganic substance is silica, colloidal silica is preferably used as the inorganic substance particles.

The dispersion of F-containing polymer particles may be stirred during or after the addition of the inorganic particles.

Examples of the device used for the stirring include a stirring device having blades (stirring blades) such as propeller blades, turbine blades, and shell-type blades.

The stirring speed in this case is only required to be able to efficiently disperse the inorganic particles in the dispersion of the F-containing polymer particles, and it is not necessary to apply a high shear force to the F-containing polymer particles.

From the viewpoint of further improving the adhesion (adhesiveness) to the inorganic particles, it is preferable to perform surface treatment on the F polymer particles before or simultaneously with mixing with the inorganic particles.

The surface treatment may, for example, be a plasma treatment, a corona discharge treatment, an etching treatment, an electron beam irradiation treatment, an ultraviolet irradiation treatment or an ozone exposure treatment, and is preferably a plasma treatment (particularly, a low-temperature plasma treatment).

When the polymer particles F and the inorganic particles are collided by the dry method a and the dry method B, the heat is easily and uniformly transferred to these particles, and the densification and spheroidizing of the present particles are easily performed, which is preferable. In this case, the sphericity of the present particle is preferably 0.5 or more.

Preferred embodiments of the present particle include a particle having an F polymer as a core and an inorganic substance attached to the surface of the core (hereinafter also referred to as "form I"), and a particle having an F polymer as a core and an inorganic substance attached to the surface of the core (hereinafter also referred to as "form II").

Here, the "core" means a core (central portion) necessary for forming the particle shape of the present particle, and does not mean a main component in the composition of the present particle.

The attachment substance (inorganic substance or F polymer) attached to the surface of the core may be attached to only a part of the surface of the core, or may be attached to a large part or the entire surface thereof. In the former case, the adhering substance is adhered to the core surface in a dust-like state, in other words, most of the core surface is exposed. The latter case may be said to be a state in which the adherent covers the surface of the core or a state in which the adherent covers the surface of the core, and the present particle may be said to have a core-shell structure formed of a core and a shell covering the core.

In the case of form I, the core of the F polymer and the inorganic substance are preferably both in the form of particles. In this case, the inorganic substance having a hardness higher than that of the F polymer is exposed on the surface, and the fluidity of the present particle is improved, and the handling property is also easily improved.

In the case of the form I, the core of the F polymer may be composed of a single particle of the F polymer or may be composed of an aggregate of particles of the F polymer.

The present particles of form I are preferably produced by dry method a or dry method B. In this case, it is preferable to set the D50 of the F polymer particles to be larger than the D50 of the inorganic particles and to set the amount of the F polymer particles to be larger than the amount of the inorganic particles. If the present particles are produced by the dry method a or the dry method B with such a relationship set, the present particles of form I can be easily obtained.

The D50 of the inorganic particles is preferably 0.0001 to 0.5, more preferably 0.0001 to 0.1, and further preferably 0.002 to 0.02, based on the D50 of the F polymer particles. Specific preferred embodiments include a form in which the D50 of the F polymer particles exceeds 20 μm and the D50 of the inorganic particles is 10 μm or less, a form in which the D50 of the F polymer particles exceeds 2 μm and the D50 of the inorganic particles is 1 μm or less, and a form in which the D50 of the F polymer particles exceeds 1 μm and the D50 of the inorganic particles is 0.1 μm or less.

The amount of the inorganic particles is preferably 0.1 part by mass or more, more preferably 1 part by mass or more, per 100 parts by mass of the F polymer particles. The upper limit is preferably 50 parts by mass, more preferably 25 parts by mass, and still more preferably 5 parts by mass.

In the present particle of form I thus obtained, the D50 of the F polymer core is larger than the D50 of the inorganic particle and the mass of the F polymer in the present particle is larger than the mass of the inorganic material. In this case, the surface of the F polymer core can be coated with a larger amount of inorganic particles, and the present particles of form I have a core-shell structure. In this case, aggregation between the F polymer particles is suppressed, and composite particles (present particles) in which inorganic particles are attached to the core formed of the F polymer particles alone are easily obtained.

In the form I, the inorganic particles are preferably spherical or flaky, more preferably spherical, and still more preferably substantially spherical. In this case, the ratio of the minor axis to the major axis of the inorganic particles is preferably 0.6 or more, more preferably 0.8 or more. The above ratio is preferably less than 1. The term "spherical" as used herein means not only a spherical shape but also a slightly deformed spherical shape.

When the highly spherical inorganic particles are used, the inorganic substance and the F polymer in the molded article (such as a polymer layer) are more uniformly distributed, and the physical properties of the two are more easily balanced.

In form I, the D50 of the inorganic particles is preferably in the range of 0.001 to 10 μm, more preferably in the range of 0.001 to 0.3. Mu.m, still more preferably in the range of 0.005 to 0.2. Mu.m, and particularly preferably in the range of 0.01 to 0.1. Mu.m. When the D50 is within the above range, the handling properties and flowability of the particles are easily improved, and the dispersion stability is also easily improved.

The particle size distribution of the inorganic particles is preferably 3 or less, more preferably 2.9 or less, as indicated by the D90/D10 value. Here, "D10" is a cumulative 10% diameter on a volume basis of the object, measured in the same manner as D50 and D90. A narrow particle size distribution is preferable from the viewpoint of easy control of the fluidity of the resulting particles.

In form I, at least a part of the surface of the inorganic particles is preferably subjected to surface treatment, and more preferably subjected to surface treatment with a silazane compound such as hexamethyldisilazane or a silane coupling agent. Examples of the silane coupling agent may include the above-mentioned compounds.

In form I, 1 or 2 or more kinds of the inorganic particles may be used in combination. When 2 kinds of inorganic particles are mixed and used, the average particle diameter of each inorganic particle may be different from each other, and the mass ratio of the content of each inorganic particle may be appropriately set according to the required function.

In the form I, it is preferable that a part of the inorganic particles is embedded in the core of the F polymer. Thereby, the inorganic particles have higher adhesion to the core of the F polymer, and the inorganic particles are less likely to fall off from the particles. That is, the stability of the present particles is further improved.

In the present particle of form I, the D50 of the F polymer core is preferably 0.1 μm or more, more preferably more than 1 μm. The upper limit is preferably 100. Mu.m, more preferably 50 μm, and still more preferably 10 μm.

The D50 of the inorganic particles is preferably 0.001 μm or more, more preferably 0.01 μm or more. The upper limit is preferably 10 μm, more preferably 1 μm, and still more preferably 0.1. Mu.m.

The proportion of the F polymer in the present particle of form I is preferably 50 to 99% by mass, and more preferably 75 to 99% by mass. The proportion of the inorganic substance is preferably 1 to 50% by mass, more preferably 1 to 25% by mass.

The ratio of the fluorine element content to the inorganic element content on the surface of the present particle in the form I measured by energy dispersive X-ray spectroscopy is preferably less than 1, more preferably 0.5 or less, and still more preferably 0.1 or less. The above ratio is preferably 0 or more. The target elements in the measurement are 4 elements of carbon, fluorine, oxygen and silicon, and the content of each element may be the ratio (unit: atomic%) of fluorine and silicon in the total.

In other words, the present particles of form I having the above mass ratio are particles whose surfaces are highly coated with an inorganic substance, and not only the particles based on an inorganic substance are excellent in physical properties (e.g., dispersibility in a liquid), but also a molded article formed therefrom is likely to have high physical properties of an inorganic substance and physical properties of an F polymer.

The present particles of form I may be further subjected to surface treatment depending on the physical properties of the inorganic substance attached to the surface. Specific examples of the surface treatment include a method of surface-treating the present particles in the form I of inorganic silica with a siloxane (e.g., polydimethylsiloxane) or a silane coupling agent.

The surface treatment can be carried out by mixing the dispersion liquid in which the particles are dispersed with a siloxane or silane coupling agent, reacting the siloxane or silane coupling agent, and then recovering the particles.

The silane coupling agent is preferably the above compound.

By this method, not only the amount of silica on the surface of the present particle but also the surface properties thereof can be further adjusted.

In the case of form II, at least a part of the F polymer is preferably fused to the surface of the inorganic core. Thus, the adhesion of the F polymer to the inorganic core is further improved, and the F polymer particles are less likely to fall off from the particles. That is, the stability of the present particles is further improved.

The inorganic core is preferably in the form of particles. In this case, the surface of the inorganic core in the present particle is easily coated with the F polymer, and therefore, the present particle is easily prevented from being aggregated.

The particles of form II are also preferably produced by the dry method a or the dry method B. In this case, it is preferable to set the D50 of the inorganic particles to be larger than the D50 of the F polymer particles and to set the amount of the inorganic particles to be larger than the amount of the F polymer particles. If the present particles are produced by the dry method a or the dry method B with such a relationship set, the present particles of form II can be easily obtained.

The D50 of the F polymer particles is preferably 0.0001 to 0.02, more preferably 0.002 to 0.1, based on the D50 of the inorganic particles.

The amount of the F polymer particles is preferably 0.1 part by mass or more, more preferably 1 part by mass or more, per 100 parts by mass of the inorganic particles. The upper limit is preferably 50 parts by mass, more preferably 10 parts by mass, and still more preferably 3 parts by mass.

In the present particle of form II thus obtained, the D50 of the inorganic core is larger than the D50 of the F polymer particle and the mass of the inorganic substance in the present particle is larger than the mass of the F polymer. In this case, the surface of the inorganic core is coated with a larger amount of the F polymer particles, and the present particles of form II have a core-shell structure.

In the present particle of form II, the D50 of the inorganic core is preferably 0.1 μm or more, more preferably more than 1 μm. The upper limit is preferably 30 μm, more preferably 6 μm.

The proportion of the inorganic substance in the present particles of form II is preferably 50 to 99% by mass, and more preferably 60 to 90% by mass. The proportion of the F polymer is preferably 1 to 50% by mass, more preferably 10 to 40% by mass.

The liquid composition of the present invention (hereinafter also referred to as "the present composition") is a composition comprising the present particles and a liquid dispersion medium, and the present particles are dispersed in the liquid dispersion medium.

The particles exhibit sufficiently high polarity and can be stably dispersed even when added in a large amount to a liquid dispersion medium. In addition, the F polymer and the inorganic substance are more uniformly distributed in the molded article (polymer layer, film, etc.) formed from the liquid composition, and the physical properties (electrical properties, adhesiveness, etc.) based on the F polymer and the physical properties (low linear expansion, etc.) based on the inorganic substance are likely to be highly exhibited.

The liquid dispersion medium of the present invention is a liquid compound which functions as a dispersion medium for the present particles and is inert at 25 ℃. The liquid dispersion medium may be water or a nonaqueous dispersion medium. The number of the liquid dispersion medium may be 1 or 2 or more. In this case, it is preferable that different kinds of liquid compounds are compatible with each other.

The boiling point of the liquid dispersion medium is preferably from 125 to 250 ℃. When the amount of the liquid dispersion medium is within this range, the particles are highly fluidized and densely packed when the liquid dispersion medium is removed from the liquid composition, and as a result, a dense molded product (polymer layer or the like) is easily formed.

The liquid dispersion medium is preferably at least 1 liquid compound selected from water, amides, ketones and esters, and more preferably water, N-methyl-2-pyrrolidone, γ -butyrolactone, methyl ethyl ketone, cyclohexanone and cyclopentanone, from the viewpoint of improving the dispersion stability of the particles in the present composition.

When the liquid dispersion medium contains an aprotic polar solvent such as N-methyl-2-pyrrolidone, at least a part of the surface of the inorganic substance in the present particles is preferably surface-treated with a silane coupling agent having at least 1 group selected from an amino group, a vinyl group and a (meth) acryloyloxy group, and more preferably surface-treated with a phenylaminosilane.

When the liquid dispersion medium contains a nonpolar solvent such as toluene, at least a part of the surface of the inorganic substance in the present particles is preferably subjected to a hydrophobic treatment, and is preferably subjected to a surface treatment with a silane coupling agent having at least 1 kind of group selected from an alkyl group and a phenyl group.

In addition, when the liquid dispersion medium contains a protic polar solvent such as water, the inorganic substance in the present particles is preferably not subjected to surface treatment.

In the case of combining the above liquid dispersion medium with an inorganic substance, the dispersion stability of the present composition tends to be better.

The content of the present particles in the present composition is preferably 1 to 50% by mass, more preferably 10 to 40% by mass.

The content of the liquid dispersion medium in the present composition is preferably 50 to 99% by mass, more preferably 60 to 90% by mass.

From the viewpoint of further improving the dispersion stability of the present particles, suppressing the sedimentation of the particles, and improving the handling properties, the present composition preferably further contains a surfactant. The surfactant is preferably a nonionic surfactant.

The hydrophilic site of the surfactant preferably has an oxyalkylene group or an alcoholic hydroxyl group.

The hydrophobic portion of the surfactant preferably has an alkyl group, an ethynyl group, a polysiloxane group, a perfluoroalkyl group, or a perfluoroalkenyl group. The surfactant is preferably a polyoxyalkylene alkyl ether, an acetylene type surfactant, a silicone type surfactant, or a fluorine type surfactant, and more preferably a silicone type surfactant. The silicone-based surfactant may be used in combination with a polyoxyalkylene alkyl ether.

Specific examples of the surfactant include "Ftergent" series (manufactured by Nippon laboratories, inc. (124935812412473), the "Surflon" series (manufactured by AGC Qing beautification chemical company, inc. (1245212511246520, 1251112559), the "MEGA FACE" series (manufactured by DIC corporation), the "Unidyne" series (manufactured by Dajin industries, inc. (124521246112461124616161102; "BYK-347", "BYK-349", "BYK-378", "BYK-3450", "BYK-3451", "BYK-3455", "BYK-3456" (manufactured by bisk chemical japan corporation (124991248312463\12597125112512572125975), "KF-6011", "KF-6043" (manufactured by shin-over chemical industry corporation, japan patent company No. v.l.).

When the present composition contains a surfactant, the content thereof is preferably 1 to 15% by mass. In this case, the dispersion stability of the particles in the present composition is more easily improved.

The viscosity of the present composition is preferably 50 mPas or more, more preferably 100 mPas or more. The viscosity of the present composition is preferably 1000 mPas or less, more preferably 800 mPas or less. In this case, since the composition is excellent in coatability, a molded article (polymer layer or the like) having an arbitrary thickness can be easily formed.

The thixotropic ratio of the present composition is preferably 1.0 or more. The thixotropic ratio of the present composition is preferably 3.0 or less, more preferably 2.0 or less. In this case, the composition is excellent not only in coatability but also in homogeneity, and therefore, a more dense molded product (such as a polymer layer) is easily formed.

The present compositions may also comprise polymers other than the F polymer or precursors thereof. As the polymer or its precursor, polytetrafluoroethylene (PTFE), a Polymer (PFA) containing a TFE unit and a PAVE unit, a polymer (FEP) containing a TFE unit and a hexafluoropropylene-based unit, a polymer (ETFE) containing a TFE unit and an ethylene-based unit, polyvinylidene fluoride (PVDF), polyimide, polyarylate, polysulfone, polyarylsulfone, polyamide, polyetheramide, polyphenylene ether, polyphenylene sulfide, polyaryletherketone, polyamideimide, liquid crystalline polyester, liquid crystalline polyesteramide, epoxy resin, maleimide resin, or the like may be cited. The PFA may be an F polymer, or may be PFA other than the F polymer.

These polymers or their precursors may be dispersed or dissolved in the present composition.

In addition, these polymers or their precursors may be thermoplastic or thermosetting.

The present composition may contain, in addition to the above components, other components such as a thixotropy-imparting agent, a viscosity-adjusting agent, an antifoaming agent, a silane coupling agent, a dehydrating agent, a plasticizer, a weather-resistant agent, an antioxidant, a heat stabilizer, a lubricant, an antistatic agent, a whitening agent, a coloring agent, a conductive agent, a mold release agent, a surface-treating agent, a flame retardant, and various fillers.

In the method for producing a laminate of the present invention (hereinafter also referred to as "method 1"), the composition is applied to the surface of a base material layer, and heated to form a polymer layer, thereby obtaining a laminate including the base material layer and the polymer layer. More specifically, in the present method 1, the present composition is applied to the surface of a base material layer to form a liquid coating film, the liquid coating film is heated to remove a liquid dispersion medium to form a dry coating film, and the dry coating film is heated to be fired to form an F polymer, thereby obtaining a laminate in which the surface of the base material layer includes a polymer layer containing the F polymer and an inorganic substance.

The heating temperature of the liquid coating is preferably 120 to 200 ℃. The heating temperature of the dried film is preferably 250 to 400 ℃, more preferably 300 to 380 ℃.

Examples of the heating method include a method using an oven, a method using a forced air drying oven, and a method of irradiating heat rays such as infrared rays.

Examples of the substrate layer include a metal substrate layer (e.g., a metal foil of copper, nickel, aluminum, titanium, or an alloy thereof), a resin film (e.g., a film of PTFE, polyimide, polyarylate, polysulfone, polyarylsulfone, polyamide, polyetheramide, polyphenylene sulfide, polyaryletherketone, polyamideimide, liquid crystalline polyester, or liquid crystalline polyesteramide), and a prepreg (a precursor of a fiber-reinforced resin substrate).

Administration of the present composition is preferably carried out by coating. Examples of the coating method include a spray method, a roll coating method, a spin coating method, a gravure coating method, a microgravure coating method, a gravure offset coating method, a blade coating method, a kiss coating method, a bar coating method, a die coating method, a jet meyer bar coating method, and a comma coating method.

The thickness of the polymer layer is preferably 0.1 to 150 μm. Specifically, when the base material layer is a metal foil, the thickness of the polymer layer is preferably 1 to 30 μm. When the base material layer is a resin film, the thickness of the polymer layer is preferably 1 to 150 μm, more preferably 10 to 50 μm.

The present composition may be applied to only one surface of the substrate layer, or may be applied to both surfaces of the substrate layer. In the former case, a laminate having a base material layer and a polymer layer on one surface of the base material layer can be obtained, and in the latter case, a laminate of a base material layer and a polymer layer on both surfaces of the base material layer can be obtained. The latter laminate is less likely to warp and therefore has excellent workability in processing.

Specific examples of the laminate include a metal-clad laminate having a metal foil and a polymer layer on at least one surface of the metal foil, and a multilayer film having a polyimide film and polymer layers on both surfaces of the polyimide film.

As the metal foil, a metal foil with carrier including 2 or more layers of metal foil may be used. The metal foil with a carrier may, for example, be a copper foil with a carrier comprising a carrier copper foil (thickness: 10 to 35 μm) and an extra thin copper foil (thickness: 2 to 5 μm) laminated on the carrier copper foil via a release layer. If the copper foil with carrier is used, a fine pattern can be formed by MSAP (modified semi-additive) method. The release layer is preferably a metal layer containing nickel or chromium, or a multilayer metal layer obtained by laminating such metal layers.

As a specific example of the metal foil with a carrier, there may be mentioned "FUTF-5DAF-2" which is a trade name of Futian Metal foil powder Industrial Co., ltd (Futian Metal foil powder Ltd.).

In order to further improve the adhesiveness of the outermost surface (the surface of the polymer layer opposite to the base material layer) of the laminate in the present method 1, it may be further subjected to a surface treatment.

Examples of the method of surface treatment include annealing treatment, corona treatment, plasma treatment, ozone treatment, excimer treatment, and silane coupling treatment.

The annealing treatment is preferably carried out at a temperature of 120 to 180 ℃ under a pressure of 0.005 to 0.015MPa for 30 to 120 minutes.

Examples of the gas used for the plasma treatment include oxygen, nitrogen, a rare gas (e.g., argon), hydrogen, ammonia, and vinyl acetate. These gases may be used in combination of 1 or 2 or more.

In the method 1, another substrate may be laminated on the outermost surface of the laminate.

The other substrate may be a heat-resistant resin film, a prepreg that is a precursor of a fiber-reinforced resin plate, a laminate having a heat-resistant resin film layer, or a laminate having a prepreg layer.

A prepreg is a sheet-like substrate in which a base material (e.g., chopped jute, woven fabric, etc.) of reinforcing fibers (e.g., glass fibers, carbon fibers, etc.) is impregnated with a thermosetting resin or a thermoplastic resin.

The heat-resistant resin film is a film containing 1 or more heat-resistant resins. Examples of the heat-resistant resin include polyimide, polyarylate, polysulfone, polyarylsulfone, aramid, aromatic polyetheramide, polyphenylene sulfide, polyaryletherketone, polyamideimide, liquid crystalline polyester, and liquid crystalline polyesteramide. Polyimides (particularly aromatic polyimides) are preferred.

As a method of stacking, a method of hot-pressing a stacked body and another substrate may be mentioned.

The hot pressing conditions when the other substrate is a prepreg are preferably a temperature of 120 to 400 ℃, an atmospheric pressure of 20kPa or less, and a pressurization pressure of 0.2 to 10MPa.

The laminate in the method 1 has a polymer layer having excellent electrical characteristics, and is therefore suitable as a printed circuit board material. Specifically, the laminate of the present invention can be used for the production of a printed circuit board as a flexible metal clad laminate or a rigid metal clad laminate, and is particularly suitable for the production of a flexible printed circuit board as a flexible metal clad laminate.

A printed board can be obtained by etching a metal foil of a laminate (polymer layer-attached metal foil) whose base layer is a metal foil to form a transmission circuit. Specifically, the printed board can be manufactured by a method of processing a metal foil into a predetermined transmission circuit by etching or a method of processing a metal foil into a predetermined transmission circuit by an electroplating method (a semi-additive process (SAP method), an MSAP method, or the like).

A printed substrate made of a metal foil with a polymer layer has a transmission circuit formed of the metal foil and the polymer layer in this order. Specific examples of the structure of the printed board include: transmission circuit/polymer layer/prepreg layer, transmission circuit/polymer layer/prepreg layer/polymer layer/transmission circuit.

In the production of the printed circuit board, an interlayer insulating film may be formed on the transmission circuit, a solder resist may be laminated on the transmission circuit, or a cover lay film may be laminated on the transmission circuit. These interlayer insulating films, solder resists, and cover films can also be formed from the present composition.

In the method for producing a film of the present invention (hereinafter also referred to as "method 2"), the particles and the fluoroolefin polymer are melt-kneaded and then extrusion-molded to obtain a film.

Since the present particles contain the F polymer having high interaction (compatibility) with the fluoroolefin polymer, the F polymer, the fluoroolefin polymer and the inorganic substance are uniformly distributed in the film obtained by uniformly melt-kneading the both, and physical properties (particularly electrical properties) based on the F polymer and the fluoroolefin polymer and physical properties (low linear expansion properties and the like) based on the inorganic substance are easily highly exhibited.

The fluoroolefin polymer melt-kneaded with the present pellets may be an F polymer, or a polymer containing a fluoroolefin-based unit other than the F polymer.

The fluoroolefin polymer may, for example, be PTFE, PFA, FEP, ETFE or PVDF. The PFA may be an F polymer, or may be PFA other than the F polymer.

The melting temperature (melting point) of the fluoroolefin polymer is preferably 160 to 330 ℃.

The glass transition temperature of the fluoroolefin polymer is preferably 45 to 150 ℃.

The fluoroolefin-based polymer preferably has a polar functional group. Preferably, both the F polymer and the fluoroolefin polymer have polar functional groups. The kind and introduction method of the polar functional group, including the preferred kind and introduction method, are the same as those described in the above-mentioned F polymer.

The melt-kneading of the particles and the TFE polymer is carried out by, for example, a single-shaft kneader. The single-shaft mixer includes a cylinder and 1 screw rotatably provided in the cylinder. When a single-shaft kneader is used, deterioration of the F polymer and TFE polymer during melt kneading can be easily prevented.

In this case, when the total length of the screw is L (mm) and the diameter is D (mm), the effective length (L/D) expressed by the ratio of the total length L to the diameter D is preferably 30 to 45. When the effective length is within the above range, the F polymer and the TFE polymer can be prevented from deteriorating and a sufficient shear stress can be applied to them, and the temperature unevenness of the melt-kneaded material can be easily reduced.

The rotation speed of the screw is preferably 10 to 50ppm.

The molten kneaded product can be discharged from a T-die provided at the front end of the cylinder. Then, the molten kneaded material discharged from the T-die comes into contact with a plurality of cooling rolls to be solidified and formed into a film. The resulting long film is wound up on a take-up roll.

The thickness of the film is preferably 5 to 150. Mu.m, more preferably 10 to 100. Mu.m.

The shape of the film may be a long strip shape or a leaf shape. The longitudinal length of the long film is preferably 100m or more. The upper limit of the length in the longitudinal direction is usually 2000m. The length of the long strip in the short side direction is preferably 1000mm or more, and the upper limit of the length in the short side direction is usually 3000mm.

The obtained film was laminated with a base material layer and then hot-pressed, thereby obtaining a laminate having a polymer layer formed of a film and a base material layer.

The hot pressing conditions are preferably a vacuum at a temperature of 120 to 300 ℃ and an atmospheric pressure of 20kPa or less, and a pressing pressure of 0.2 to 10MPa.

The forms of the base material layer, the printed board using the laminate, and the multilayer printed circuit board, including preferred forms thereof, are the same as those described in method 1.

In addition, a circular die may be used instead of the T-die to manufacture the blown film.

The composite particles, the method for producing the composite particles, the liquid composition, the method for producing the laminate, and the method for producing the film of the present invention have been described above, but the present invention is not limited to the configuration of the above embodiment.

For example, the composite particles and the liquid composition of the present invention may be configured by adding any other arbitrary configuration to the configurations of the above embodiments, or may be replaced with any configuration that exerts the same function.

In the method for producing composite particles, the method for producing a laminate, and the method for producing a film according to the present invention, other arbitrary steps may be added to the structure of the above embodiment, respectively, or may be replaced with arbitrary steps that produce the same effect.

Examples

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

1. Preparation of the Components

[ particles of Polymer ]

Particle 1 of F polymer 1: particles (D50: 2.0 μm) composed of F Polymer 1 (melting temperature: 300 ℃) having a polar functional group comprising 97.9 mol% TFE units, 0.1 mol% NAH units and 2.0 mol% PPVE units

Particles of polymer 2: particles composed of F Polymer 2 (melting temperature: 300 ℃) having no polar functional group, containing 97.5 mol% TFE units and 2.5 mol% PPVE units (D50: 2.6 μm)

Particles of non-F polymer: particles (D50: 2.1 μm) composed of a non-F polymer having no polar functional group (melting temperature: 305 ℃) comprising 98.7 mol% TFE units and 1.3 mol% PPVE units

PTFE particles: particles (D50: 2.4 μm) of fibrillar, non-heat-fusible PTFE

Particle 2 of polymer 1: particles composed of F Polymer 1 (D50: 25 μm)

In addition, the number of carbons in the F polymer 1 was 1 × 10 with respect to the main chain ⁶ The number of carbonyl-containing groups was 1000, and 40 in the F polymer 2. The melt viscosities of the F polymer 1 and the F polymer 2 were 1X 10 at 380 ℃ both ³ ～1×10 ⁶ Pa · s, and the glass transition temperatures of the F polymer 1 and the F polymer 2 are both in the range of 80 to 100 ℃.

[ particles of inorganic substance ]

Silica particles 1: spherical particles made of silica (D50: 0.5 μm, roughly spherical)

Silica particles 2: spherical particles (D50: 0.03 μm, substantially spherical) comprising silica surface-treated with a silane coupling agent

Boron nitride particles: scaly particles (D50: 7.0 μm, aspect ratio: 1000 or less) composed of boron nitride

2. Production of composite particles

(example 1)

A mixture of 98 parts by mass of the particles 1 of the F polymer 1 and 2 parts by mass of the silica particles 1 was prepared.

Then, the mixture is put into a powder processing apparatus (mechanical fusion) including a cylindrical rotating body having a receiving surface on an inner peripheral surface thereof and an inner stator disposed at a minute distance from the receiving surface. Then, the cylindrical rotating body is rotated at a high speed around the central axis. The particles are pressed against the receiving surface by the centrifugal force generated at this time, and the mixture is introduced into a narrow space (pressing space) between the receiving surface and the inner stator, and the particles are collided in a shear state to be processed. The atmospheric temperature of the cylindrical rotating body during the treatment was maintained at 100 ℃ or lower, and the treatment time was 15 minutes.

The obtained treated product was in the form of fine powder. The powder was analyzed by an optical microscope, and it was confirmed that the powder was a composite particle 1 having a core-shell structure in which the F polymer 1 was used as a core and the silica particle 1 was attached to the surface of the core to form a shell.

The ratio of the fluorine element content to the silicon element content (hereinafter also referred to as "F/Si ratio") on the surface of the composite particle measured by energy dispersive X-ray spectrometry was 0.006. The target elements in the measurement are 4 elements of carbon, fluorine, oxygen and silicon, and the content of each element is defined as the ratio (unit: atomic%) of fluorine and silicon in the total.

The composite particle 1 had a spherical shape, a D50 of 20 μm, and a kinetic friction angle of 18 degrees.

After the composite particles 1 were produced, a mixture of 98 parts by mass of the particles 1 of the F polymer 1 and 2 parts by mass of the silica particles 1 was directly charged into the mechanical fusion apparatus without cleaning the mechanical fusion apparatus, and a treated product was obtained, which was the same particles as the composite particles 1.

(example 2)

Composite particles 2 were obtained in the same manner as in example 1, except that a mixture was prepared using 95 parts by mass of the particles 1 of the F polymer 1 and 5 parts by mass of the silica particles 1. The F/Si ratio of the composite particle 2 was 0.337, and the D50 thereof was 30 μm.

(example 3)

Composite particles 3 were obtained in the same manner as in example 1, except that 75 parts by mass of the particles 1 of the F polymer 1 and 25 parts by mass of the silica particles 1 were used to prepare a mixture. The F/Si ratio of the composite particle 3 was 0.672, and the D50 thereof was 40 μm.

(example 4)

Composite particles 4 were obtained in the same manner as in example 2, except that the particles 1 of the F polymer 1 were changed to the particles of the F polymer 2. The F/Si ratio of the composite particles 4 was 0.555, the D50 thereof was 35 μm, and the kinetic friction angle of the powder was 25 degrees.

(example 5)

Composite particles 5 were obtained in the same manner as in example 1, except that the particles 1 of the F polymer 1 were changed to particles of a non-F polymer. The F/Si ratio of the composite particles 5 exceeded 1, the D50 thereof was 50 μm, and the kinetic friction angle of the powder was 45 degrees.

(example 6)

Treatment was performed in the same manner as in example 1, except that the particles 1 of the F polymer 1 were changed to those of PTFE. The resulting treated material was a non-particulate cake.

(example 7)

Composite particles 7 were obtained in the same manner as in example 1, except that a mixture was prepared using 10 parts by mass of the particles 1 of the F polymer 1 and 90 parts by mass of the particles 1 of silica. The composite particle 7 was analyzed by an optical microscope, and was confirmed to be a core-shell structure composite particle in which silica was used as a core and the F polymer 1 was attached to the surface of the core to form a shell.

(example 8)

Composite particles 8 were obtained in the same manner as in example 1, except that the silica particles 1 were changed to the silica particles 2. The F/Si ratio of the composite particles 8 was 0.005, the D50 thereof was 5.5 μm, and the kinetic friction angle of the powder was 16 degrees.

(example 9)

First, a mixture of 70 parts by mass of the particles 2 of the F polymer 1 and 30 parts by mass of the boron nitride particles was prepared.

Then, the mixture is put into a powder processing apparatus (hybrid system) in which particles are stirred by a stirring blade rotating at a high speed in a cylindrical container and are held between the inner wall of the container and a stirring body by applying stress. Next, the particles 2 of the F polymer 1 and the boron nitride particles are caused to collide with each other while floating in a high-temperature turbulent atmosphere, and a stress is applied between them to perform a composite treatment. The temperature in the apparatus during the treatment was maintained at 100 ℃ or lower under a nitrogen atmosphere, and the treatment time was 15 minutes.

The obtained treated product was in the form of fine powder. The powder was analyzed by an optical microscope, and it was confirmed that the powder was a core-shell structure composite particle 9 in which the F polymer 1 was used as a core and boron nitride particles were attached to the surface of the core to form a shell.

The composite particles 9 were spherical, had a D50 of 35 μm, and had a powder kinetic friction angle of 26 degrees.

3. Evaluation of

3-1 evaluation of Dispersion stability

The composite particles 1 to 5 and 7 to 9 were dispersed in water to prepare a dispersion, and after leaving to stand for a predetermined time, the dispersion stability was evaluated according to the following criteria.

[ evaluation standards ]

Good: foaming was suppressed during preparation, and no deposit was formed after standing at 25 ℃ for 3 days after preparation.

And (delta): foaming occurred during preparation, but no sediment was generated after standing at 25 ℃ for 3 days after preparation.

X: a deposit was formed after standing at 25 ℃ for 3 days.

As a result, the composite particles 1,2, and 7 to 9 were "good", the composite particles 3 and 4 were "Δ", and the composite particle 5 was "x". The composite particles 8 take the longest time to generate deposits.

3-2 evaluation of dusting and warping

First, each of the composite particles 1 to 4 and 7 to 9 and N-methyl-2-pyrrolidone (NMP) were charged into a pot, and after zirconia balls were charged into the pot, the pot was rolled at 150rpm × 1 hour to prepare a liquid composition.

Then, the liquid composition was applied to the surface of the long copper foil by a bar coater to form a liquid coating film. Next, the metal foil on which the liquid coating film was formed was passed through a drying oven at 120 ℃ for 5 minutes, and dried by heating to obtain a dried coating film. Then, the dried film was heated at 380 ℃ for 3 minutes in a nitrogen furnace. Thus, a laminate comprising a copper foil and a polymer layer comprising a polymer-containing melt-fired product and an inorganic substance on the surface thereof was obtained.

Subsequently, the dry film was evaluated for dusting and warpage of the laminate.

The edge of the dried film was visually confirmed, and the dry film was evaluated for flaking according to the following criteria.

[ evaluation criteria for flaking ]

Good: no detachment was observed at the edge of the dried film.

And (delta): the edge of the dried film was partially peeled off.

X: the edge of the dried film was found to fall off over a wide range.

Further, a 180mm square test piece was cut out from the laminate, and the test piece was measured according to the measurement method prescribed in JIS C6471.

[ evaluation criteria for warpage ]

Good: the linear expansion coefficient is less than +/-20 ppm/DEG C.

X: the linear expansion coefficient is more than plus or minus 20 ppm/DEG C.

These results are shown in table 1 below.

[ Table 1]

	Powder falling	Warp of
			Composite particle 1	○	○
Composite particle 2	△	○
			Composite particles 3	△	×
Composite particles 4	×	×
			Composite particles 7	○	○
Composite particles 8	○	○
			Composite particles 9	○	○

4. Manufacture of membranes

(example 10)

The composite particles 1 (50 parts by mass) and the particles 1 (50 parts by mass) of the F polymer 1 were stirred by a stirrer to prepare a mixture. Using a single-shaft extruder (with 700mm wide clothes-hanger die)

Single-shaft extruder) at a die temperature of 340 ℃ to obtain a film 1 having a width of 500mm, a length of 100m and a thickness of 25 μm. The film 1 has a decreased linear expansion coefficient as compared with the film formed of only the F polymer 1.

Industrial applicability of the invention

The composite particles of the present invention have excellent dispersion stability in a liquid composition. The liquid composition can be used for producing molded articles (laminates, films, etc.) having high physical properties based on the F polymer and properties based on inorganic substances. The molded article of the present invention is useful as an antenna member, a printed circuit board, an airplane member, an automobile member, a sports equipment, a food industrial product, a paint, a cosmetic, and the like, and specifically, as a heat radiating member (a heat radiating member for an electronic device, an engine, and the like), an electric wire coating material (an electric wire for an airplane, and the like), an electrically insulating tape, an insulating tape for oil excavation, a material for a printed circuit board, a separation film (a microfiltration membrane, an ultrafiltration membrane, a reverse osmosis membrane, an ion exchange membrane, a dialysis membrane, a gas separation membrane, and the like), an electrode adhesive (for a lithium secondary battery, a fuel battery, and the like), a copying roll, furniture, an automobile instrument panel, a cover for a home electric appliance, and the like, an outer surface coating material for a sliding member (a load bearing, a sliding shaft, a valve, a bearing, a gear, a cam, a conveyor belt, a food conveyor belt, and the like), a tool (a shovel, a file, a awl, a saw, a container coating material, a heat exchanger (a fin, a heat pipe, and the like) for a cooling and the like).

Claims

1. Composite particles comprising at least 1 kind of tetrafluoroethylene polymer having a melting temperature of 260 to 320 ℃ and an inorganic substance, wherein the tetrafluoroethylene polymer is selected from the group consisting of a tetrafluoroethylene polymer having a polar functional group and a tetrafluoroethylene polymer having a perfluoro (alkyl vinyl ether) -based unit, and a tetrafluoroethylene polymer having no polar functional group and containing a perfluoro (alkyl vinyl ether) -based unit in an amount of 2.0 to 5.0 mol% based on the total units.

2. The composite particle according to claim 1, wherein the powder kinetic friction angle of the composite particle is 40 degrees or less.

3. The composite particle according to claim 1 or 2, wherein the inorganic substance is silica or boron nitride.

4. The composite particle according to any one of claims 1 to 3, wherein the composite particle is spherical or scaly.

5. The composite particle according to any one of claims 1 to 4, wherein the tetrafluoroethylene polymer is used as a core, and the inorganic substance is present on the surface of the core.

6. The composite particles according to claim 5, wherein the core of the tetrafluoroethylene polymer and the inorganic substance are each in a particulate form, and the average particle diameter of the core is larger than the average particle diameter of the inorganic substance.

7. The composite particle according to claim 5 or 6, wherein a ratio of a fluorine element content to an inorganic element content of the surface of the composite particle measured by energy dispersive X-ray spectroscopy is less than 1.

8. The composite particle according to any one of claims 1 to 4, wherein the inorganic substance is used as a core, and the tetrafluoroethylene polymer is provided on the surface of the core.

9. The composite particle according to claim 8, wherein the inorganic substance in the composite particle has a mass larger than that of the tetrafluoroethylene-based polymer.

10. A method for producing the composite particle according to any one of claims 1 to 9, wherein the composite particle is obtained by colliding the tetrafluoroethylene polymer particle and the inorganic substance particle at a temperature equal to or higher than the melting temperature of the tetrafluoroethylene polymer and in a suspended state.

11. A method for producing the composite particles according to any one of claims 1 to 9, wherein the composite particles are obtained by colliding the particles of the tetrafluoroethylene polymer and the particles of the inorganic substance in a pressed or sheared state.

12. A liquid composition comprising the composite particles according to any one of claims 1 to 9 and a liquid dispersion medium, wherein the composite particles are dispersed in the liquid dispersion.

13. The liquid composition of claim 12, wherein the liquid dispersion medium is at least 1 liquid compound selected from the group consisting of water, amides, ketones, and esters.

14. A method for producing a laminate, wherein the liquid composition according to claim 12 or 13 is applied to the surface of a base material layer, and heated to form a polymer layer, thereby obtaining a laminate comprising the base material layer and the polymer layer.

15. A method for producing a film, wherein the composite particles according to any one of claims 1 to 9 and a fluoroolefin polymer are melt-kneaded and then extrusion-molded to obtain a film.