TW202323429A - Liquid composition, laminate, and production methods therefor - Google Patents

Abstract

Provided are: a liquid composition which has excellent uniformity and dispersion stability and has a low viscosity; a method for producing said liquid composition; a method for producing a laminate which is obtained from said composition and has a polymer layer having excellent adhesiveness to a substrate, thermal conductivity, heat resistance, and electrical characteristics; and said laminate. The liquid composition contains: particles of a tetrafluoroethylene-based polymer; spherical silica which has a median diameter d ([mu]m) of 0.6-20 [mu]m (exclusive of 0.6) and a product d*A of the median diameter d and a specific surface area A (m2/g) of 2.7-5.0 [mu]m.m2/g; and a liquid dispersion medium.

Description

Method for producing liquid composition, laminate and the like

The present invention relates to a liquid composition comprising a tetrafluoroethylene polymer and silicon oxide, a method for producing the same, a laminate having a polymer layer formed from the liquid composition, and a method for producing the same.

In recent years, in order to cope with the high speed and high frequency of mobile communication devices such as mobile phones, materials with high thermal conductivity, low linear expansion coefficient, low dielectric constant and low dielectric tangent are being sought for printed substrate materials for communication devices. Tetrafluoroethylene-based polymers with a low dielectric constant and a low dielectric tangent are attracting attention. Various studies have been conducted to obtain materials containing tetrafluoroethylene-based polymers with more excellent physical properties. For example, Patent Document 1 discloses a laminated body comprising tetrafluoroethylene-based polymers and specific silicon oxide particles. The liquid composition is coated on the substrate to form. Patent Document 2 describes adding a non-aqueous dispersion containing polytetrafluoroethylene, ceramic fine particles, and a specific fluorine-based additive to various resin materials. prior art literature patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2019-183005 Patent Document 2: Japanese Patent Laid-Open No. 2016-194017

Problems to be Solved by the Invention Tetrafluoroethylene-based polymers have low surface tension and low affinity with other components such as inorganic particles. Therefore, in a molded article formed of a composition including a tetrafluoroethylene-based polymer and inorganic particles, the dispersibility of the inorganic particles may not be sufficient, and the physical properties of each component may not be sufficiently exhibited. In terms of the liquid composition described in Patent Document 1, from the viewpoint of exhibiting the effect of suppressing the linear expansion of the resulting molded product with a small amount of silicon oxide added, it is appropriate to select silicon oxide particles with a specific surface area of 6.5 m ² /g Among the above, porous silicon oxide particles, microporous silicon oxide particles, hollow silicon oxide particles, etc. That is, there is still room for improvement from the viewpoint of increasing the added amount of silicon oxide to further exhibit the characteristics based on silicon oxide. In the non-aqueous dispersion described in Patent Document 2, when the type of ceramic fine particles as inorganic particles is increased, or the amount of ceramic fine particles is added, or other components are further mixed, the uniformity and dispersion stability of the composition will decrease. The problem that it is difficult to obtain a molded article such as a polymer layer having sufficient properties.

The inventors of the present invention have observed that by using tetrafluoroethylene polymer particles and specific spherical silica, a liquid composition with excellent uniformity and dispersion stability and suppressed viscosity increase can be obtained. In addition, it can be seen that a thick polymer layer can be formed from the above-mentioned liquid composition, which has excellent electrical properties such as adhesion to the substrate, thermal conductivity, heat resistance, and dielectric tangent, and a laminate system having the polymer layer It is used as a material for printed wiring boards and the like, and the present invention has been accomplished. The object of the present invention is to provide a low-viscosity liquid composition excellent in uniformity and dispersion stability, a method for producing the liquid composition, a method for producing a laminate having a polymer layer obtained from the composition, and The laminate.

MEANS TO SOLVE THE PROBLEM This invention has the following aspects. [1] A liquid composition comprising: tetrafluoroethylene-based polymer particles; spherical silica having a median diameter d (μm) greater than 0.6 μm and 20 μm or less, and the median diameter d (μm) and specific surface area The product d×A of A(m ² /g) is 2.7~5.0μm･m ² /g; and a liquid dispersion medium. [2] The liquid composition according to [1], wherein the tetrafluoroethylene polymer is a hot-melt tetrafluoroethylene polymer. [3] The liquid composition according to [1] or [2], wherein the aforementioned tetrafluoroethylene-based polymer is a tetrafluoroethylene-based polymer having an oxygen-containing polar group, which contains perfluoro(alkyl vinyl ether ) is the unit of the subject. [4] The liquid composition according to any one of [1] to [3], wherein the spherical silicon oxide has a specific surface area of 0.2 to 2.0 m ² /g. [5] The liquid composition according to any one of [1] to [4], wherein the maximum IR peak intensity at 3300 to 3700 cm ^-1 originating from bonded silanol groups on the spherical silicon oxide surface is Below 0.2.

[6] The liquid composition according to any one of [1] to [5], wherein the content of the spherical silicon oxide is 10 to 60% by mass relative to the entire mass of the liquid composition, and the tetrafluoroethylene The content of the ethylene-based polymer particles is 10 to 40% by mass, and the content of the aforementioned liquid dispersion medium is 5% by mass or more. [7] The liquid composition according to any one of [1] to [6], wherein the content of the spherical silicon oxide is larger than the content of the tetrafluoroethylene-based polymer particles. [8] The liquid composition according to any one of [1] to [7], further comprising a surfactant. [9] The liquid composition according to any one of [1] to [8], further comprising an aromatic polymer. [10] The liquid composition according to any one of [1] to [9], further comprising an inorganic filler different from the aforementioned spherical silica. [11] The liquid composition according to any one of [1] to [10], which has a viscosity of 50 to 1000 mPa･s.

[12] A method for producing the liquid composition according to any one of [1] to [11], comprising mixing the aforementioned tetrafluoroethylene-based polymer particles, the aforementioned spherical silica, and the aforementioned liquid dispersion medium to obtain a liquid composition. shape composition. [13] A method for producing a liquid composition, which is to manufacture the liquid composition according to any one of [1] to [11], the method is as follows: Kneading a composition containing the aforementioned tetrafluoroethylene-based polymer particles, the aforementioned spherical silica, and a part of the aforementioned liquid dispersion medium to obtain a kneaded product, and further adding the remaining aforementioned liquid dispersion medium to the aforementioned kneaded material and mixing to form The aforementioned liquid composition was obtained. [14] A method for producing a laminate, comprising: applying the liquid composition according to any one of [1] to [11] to the surface of a substrate to form a liquid film composed of the liquid composition, followed by heating Then, the liquid dispersion medium is removed from the liquid film, and a polymer layer comprising the tetrafluoroethylene polymer and the spherical silicon oxide is formed on the surface of the substrate. [15] A laminate comprising: a substrate; and a polymer layer provided on the surface of the substrate and formed of the liquid composition according to any one of [1] to [11], including tetrafluoroethylene It is a polymer and the aforementioned spherical silica.

Invention effect According to the present invention, it is possible to provide a low-viscosity liquid composition having excellent uniformity and dispersion stability, a method for producing the liquid composition, a method for producing a laminate, and the laminate comprising the The polymer layer obtained from the composition has excellent adhesion to the substrate, thermal conductivity, heat resistance and electrical properties.

The following terms have the following meanings. The "melting temperature of a polymer" is a temperature corresponding to the maximum value of a melting peak measured by a differential scanning calorimetry (DSC) method. "Glass transition point of a polymer" is a value determined by analyzing a polymer with a dynamic viscoelasticity measurement (DMA) method. "Average particle size of tetrafluoroethylene-based polymer particles" is the particle size of the particles measured by the laser diffraction and scattering method, and the obtained particle size is the volume-based cumulative 50% particle size (hereinafter also expressed as "D50") ). That is, the particle size distribution of the particles is measured by the laser diffraction and scattering method, and the cumulative curve is calculated with the total volume of the particle group as 100%, and the particle diameter at the point where the cumulative volume becomes 50% on the cumulative curve. The "specific surface area of particles" is a value measured by the gas adsorption (constant volume method) BET multi-point method. "Viscosity" is a value measured for a dispersion liquid at room temperature (25° C.) and at a rotation speed of 30 rpm using a B-type viscometer. The measurement was repeated 3 times, and the average value of the 3 measurements was taken as the viscosity. "Thixotropic ratio" refers to the value calculated by dividing the viscosity η1 obtained by measuring the liquid composition at a rotation speed of 30 rpm by the viscosity η2 obtained by measuring the rotation speed at 60 rpm (η1/η2). The "unit mainly composed of a monomer" means an atomic group mainly composed of one molecule of the aforementioned monomer formed by polymerization of a monomer. The unit may be a unit directly formed by a polymerization reaction, or may be a unit in which a part of the aforementioned unit is converted into another structure by treating a polymer. In the following, the unit whose main component is monomer a is also simply expressed as "monomer a unit".

The liquid composition of the present invention (hereinafter also referred to as "this composition") includes: tetrafluoroethylene polymer (hereinafter also referred to as "F polymer") particles (hereinafter also referred to as "F particle"); Shaped silica (hereinafter also referred to as "this spherical silica"), the median particle size d (μm) is greater than 0.6 μm and not more than 20 μm, and the aforementioned median particle size d and specific surface area A (m ² /g) The product d×A is 2.7~5.0μm･m ² /g; and a liquid dispersion medium. This composition is excellent in uniformity and dispersion stability and has low viscosity. In addition, a thick polymer layer can be obtained from this composition, which has excellent electrical properties such as adhesion to the substrate, thermal conductivity, heat resistance, and low dielectric tangent. The laminated system having such a polymer layer is useful as a material for a printed wiring board or the like having adhesiveness, thermal conductivity, and electrical properties. The reason why the properties of this composition are exhibited is not clear, but it can be speculated as follows, for example.

The surface energy of F polymer is low, and its particles are easy to aggregate with each other. In addition, the affinity between the F polymer and inorganic particles such as silicon oxide is low, and the inorganic particles tend to form aggregates in the polymer layer containing the F polymer and the inorganic particles. This tendency tends to become prominent when the content of inorganic particles is large. The spherical silicon oxide used in this composition (this spherical silicon oxide) has the median particle size d in the aforementioned specific range, and the product d×A of the aforementioned median particle size d and the specific surface area A is in the specific range. From this, we judged that not only the aggregation of silicon oxides in this composition is suppressed, but also the wettability between silicon oxide and liquid dispersion medium is adjusted, and the affinity between spherical silicon oxide and F polymer is relatively increased. We judge that this is because the high degree of interaction between the F particles and the spherical silicon oxide is promoted, so the dispersion stability, low viscosity and other physical properties of the composition are excellent. In addition, we also speculate that for this composition in which the two particles are in a highly interactive state, the self-coagulation (self coagulation) of the F particles and the spherical silica is easily promoted. In other words, the self-coagulation of the F particles and the spherical silica The formation of pseudo-coalescent particles is easily promoted. We judge that this is because the uniformity of this composition is improved, so this composition has excellent physical properties such as dispersion stability and low viscosity.

Moreover, if the two particles highly interact with each other and have excellent physical properties such as dispersion stability and low viscosity, spherical silicon oxide is difficult to form even when the molded product is processed or in the state of the processed molded product. Falling powder, and the spherical silicon oxide is also highly dispersed in the molded product. As a result, we judged that this composition can easily form a molded product, which highly possesses the original physical properties of silicon oxide and F polymer, as well as adhesion to the substrate, thermal conductivity, heat resistance and low dielectric Excellent electrical properties such as tangent.

The F polymer in this composition is a polymer containing units mainly composed of tetrafluoroethylene (TFE) (TFE unit). The F polymer may be thermally fusible or non-thermally fusible. For this composition, it is preferable to use a hot-melt F polymer. In addition, a hot-melt polymer means a polymer having a melt flow rate of 1 to 1000 g/10 minutes at a temperature 20° C. or higher than the melting temperature of the polymer under a load of 49 N. Two or more types of F polymers may be used.

The melting temperature of the hot-melt F polymer is preferably above 200°C, more preferably above 260°C. The melting temperature of F polymer is preferably below 325°C, preferably below 320°C. In such a case, the molded article formed from this composition tends to be excellent in heat resistance. The fluorine content in the F polymer is preferably at least 70% by mass, preferably 72-76% by mass. According to this method, the polymer layer having excellent dispersibility of the spherical silica can be easily obtained even when the F polymer having a high fluorine content and a low affinity with inorganic particles is used due to the above-mentioned mechanism of action. The glass transition point of F polymer is preferably above 50°C, preferably above 75°C. The glass transition point of F polymer is preferably below 150°C, preferably below 125°C.

F polymers include: polymers containing polytetrafluoroethylene (PTFE), TFE units and ethylene units, polymers containing TFE units and propylene units, polymers containing TFE units and perfluoro(alkyl vinyl ether) (PAVE ) as the main unit (PAVE unit) of the polymer (PFA), including TFE units and hexafluoropropylene units (FEP), including TFE units and fluoroalkylethylene as the main unit of the polymer, including TFE A polymer of units and chlorotrifluoroethylene units. PTFE may be non-thermofusible PTFE or thermofusible PTFE. The F polymer is preferably PFA and FEP, and PFA is more preferred. These polymers may further comprise units based on other comonomers. PAVE is preferably CF ₂ =CFOCF ₃ , CF ₂ =CFOCF ₂ CF ₃ and CF ₂ =CFOCF ₂ CF ₂ CF ₃ (hereinafter also denoted as PPVE), and PPVE is preferred.

The F polymer preferably has an oxygen-containing polar group. When the F polymer has an oxygen-containing polar group, the affinity between the F particles and the spherical silica tends to increase, and the spherical silica tends to be well dispersed in the polymer layer. In addition, we judged that when this composition is heated, crosslinking of the polymer F is easily formed, and a polymer layer having excellent mechanical properties is easily obtained. In particular, if the above F polymer is used, the above-mentioned mechanism of action, especially the effect utilizing self-aggregation can be easily exhibited to a high degree. The oxygen-containing polar group can be contained in the monomer-based unit in the F polymer, or it can be contained in the terminal group of the main chain of the F polymer. Examples of the latter include F polymers having oxygen-containing polar groups as terminal groups derived from polymerization initiators, chain transfer agents, etc., and oxygen-containing polar groups obtained by subjecting F polymers to plasma treatment or free ray treatment. Polar group F polymer.

When the F polymer has oxygen-containing polar groups, the number of oxygen-containing polar groups in the F polymer is preferably 100-10000, more preferably 500-5000, relative to 1×10 ⁶ carbons per main chain. The oxygen-containing polar group is preferably a hydroxyl-containing group, a carbonyl-containing group, and an isophosphorous acid-containing group. From the viewpoint of the dispersion of the spherical silica in the polymer layer, the hydroxyl-containing group and the carbonyl-containing group A group is preferable, and a group containing a carbonyl group is more preferable.

The hydroxyl-containing group is preferably a group containing an alcoholic hydroxyl group, preferably -CF ₂ CH ₂ OH, -C(CF ₃ ) ₂ OH and 1,2-diol group (-CH(OH)CH ₂ OH). The carbonyl-containing group is a group containing a carbonyl group (>C(O)), and the carbonyl-containing group is preferably a carboxyl group, an alkoxycarbonyl group, an amide group, an isocyanate group, a carbamate group (-OC(O)NH ₂ ), anhydride residues (-C(O)OC(O)-), imide residues (-C(O)NHC(O)-, etc.) and carbonate groups (-OC(O)O-), Anhydride residues are preferred. The aforementioned carbonyl-containing group may be contained in the monomer unit in the F polymer, or may be contained in the terminal group of the polymer main chain. The latter aspect includes F polymer having the aforementioned carbonyl group-containing group as a terminal group derived from a polymerization initiator, a chain transfer agent, and the like. When the F polymer has carbonyl-containing groups, the number of carbonyl-containing groups in the F polymer is preferably 100 to 10,000, preferably 500 to 5,000, relative to 1×10 ⁶ carbons per main chain. 800~1500 is better. At this time, the affinity between the F polymer and the spherical silica is easily improved. In addition, the number of carbonyl-containing groups in the F polymer can be quantified by the composition of the polymer or the method described in International Publication No. 2020/145133.

F The polymer is preferably a polymer comprising TFE units and PAVE units and having oxygen-containing polar groups, preferably a polymer comprising TFE units and PAVE units and having carbonyl-containing groups or hydroxyl-containing groups, including TFE units and PAVE units And a polymer whose main unit is a monomer having a carbonyl group is more preferable. Relative to the total units, the F polymer preferably contains 90-99 mol% of TFE units, 0.5-9.97 mol% of PAVE units, and 0.01-3 mol% of the aforementioned units having carbonyl-containing groups. The body is the unit of the subject. The monomer having a carbonyl-containing group is preferably itaconic anhydride, citraconic anhydride, and 5-norbornene-2,3-dicarboxylic anhydride (hereinafter also referred to as "NAH"). Specific examples of the polymer include those described in International Publication No. 2018/16644. These F polymers are not only excellent in the dispersion stability of their particles, but also more finely and homogeneously distributed in the molded product (polymer layer, etc.) obtained from this composition. Furthermore, fine spherulites are easily formed in the molded product, and the adhesion with other components including the present spherical silicon oxide tends to increase. As a result, it becomes easier to obtain a molded article excellent in various physical properties such as electrical characteristics.

The D50 of the F particles in this composition is preferably 25 μm or less, preferably 10 μm or less, more preferably 8 μm or less. The D50 of F particles is preferably at least 0.1 μm, more preferably at least 0.3 μm, more preferably at least 1 μm. At this time, the aggregation inhibition of the particles and the interaction between the F particles and the spherical silicon oxide are highly balanced, and the dispersion stability of the composition is easily improved. In addition, the present spherical silicon oxide is easily and highly dispersed in the polymer layer.

The bulk density of F particles is preferably 0.15 g/m ² or more. The overall density of F particles is preferably 0.50 g/m ² or less. Also, the specific surface area of the F particles is preferably not more than 25 m ² /g, preferably not more than 8 m ² /g, more preferably not more than 5 m ² /g. The specific surface area of the F particles is preferably not less than 1 m ² /g. At this time, the aggregation of the particles is highly suppressed, and the interaction between the F particles and the spherical silicon oxide is easily enhanced.

Two or more types of F particles may be used. When using two types of F particles, the F particles preferably include heat-melting F polymer particles and non-heat-melting F polymer particles, preferably F polymers with a melting temperature of 200-320°C (suitable for the above-mentioned TFE Units and PAVE units and polymers with oxygen-containing polar groups) particles and non-heat-melting PTFE particles. Furthermore, it is more preferable that the content of the latter particle is larger than the content of the former particle. At this time, the F polymer is appropriately fibrillated while maintaining the physical properties, and the F particles are easily supported in the molded article formed from this composition, and the strength of the molded article is easily further improved. Also, the ratio of the former particles to the total of the former particles and the latter particles is preferably 50% by mass or less, preferably 25% by mass or less. In addition, the ratio at this time is preferably at least 0.1% by mass, preferably at least 1% by mass. The present composition is not only easy to be excellent in dispersion stability, uniformity, and handling, but also easy to form an adhesive molded product with excellent physical properties based on non-thermal fusible PTFE. In addition, at this time, the following aspect is preferable: the D50 of the F polymer particles having a melting temperature of 200 to 320°C is 0.1 to 1 μm and the D50 of the non-thermally fusible PTFE particles is 0.1 to 1 μm, or the melting temperature The D50 of the F polymer particles at 200~320°C is 1~4μm and the D50 of the non-thermofusible PTFE particles is 0.1~1μm. In addition, the non-heat-melting polymer means a polymer that does not have a temperature at which the melt flow rate is 1 g or more and 1000 g or less per 10 minutes under a load of 49 N.

The F particles may also contain resins or inorganic substances other than the F polymer, but it is preferable to use the F polymer as the main component. The content of the F polymer in the F particles is preferably at least 80% by mass, more preferably 100% by mass.

The spherical silica in this composition is solid silica, the median particle size d (μm) is greater than 0.6 μm and not more than 20 μm, and the product of the aforementioned median particle size d and specific surface area A (m ² /g) The d×A position is in the range of 2.7~5.0μm･m ² /g (2.7≦A×d50(μm･m ² /g)≦5.0). If the median particle size d is larger than 0.6 µm, the dielectric tangent can be significantly reduced. On the other hand, when the median diameter d becomes larger, the value of the grind gauge becomes larger (measured by the JIS K5400 grind gauge method). When forming this composition into a polymer layer, for example, from the viewpoint of controlling the minimum thickness of the polymer layer, the median particle size d is preferably greater than 0.6 μm and 10 μm or less, more preferably 1 to 5 μm. In addition, the median particle size d of the present spherical silica is obtained by a laser diffraction particle size distribution measuring device (for example, "MT3300EXII" manufactured by Microtrac BEL Co., Ltd.). Specifically, the spherical silicon oxide powder was dispersed by irradiating the apparatus with ultrasonic waves three times for 60 seconds, and then measured twice for 60 seconds to obtain the average value.

The product d×A of the median particle diameter d of the spherical silica and the specific surface area A is 2.7~5.0μm･m ² /g, preferably 2.7~4.5μm･m ² /g, preferably 2.7~4.0μm ･m ² /g. The theoretical value of d×A is 2.7 (derived from specific surface area=6/(true density of silicon oxide 2.2×median particle size d)), and values below it cannot be achieved in reality. Since the larger the value of d×A, the specific surface area of each particle size becomes larger, which will lead to a larger dielectric tangent, so in order to reduce the dielectric tangent to about 0.0020 or less at a frequency of 1GHz, d×A 5.0 μm･m ² /g or less.

The specific surface area A of the spherical silicon oxide is preferably in the range of 0.2~2.0m ² /g. If the specific surface area is 0.2m ² /g or more, when the present composition contains this spherical silica, since there are sufficient contact points with the F polymer, the adaptability (fitness) with the F polymer becomes better. If it is 2.0m ² /g or less, the dielectric tangent can be reduced, so the molded product obtained from this composition can exhibit an excellent low dielectric tangent, and the dispersibility in the molded product can be improved. In addition, we judged that for the present spherical silica, the presence of particles with a small median particle size or surface roughness contributes to the suppression of thickening of the present composition. The specific surface area A is preferably not more than 1.5 m ² /g, more preferably not more than 1.0 m ² /g, and most preferably not more than 0.8 m ² /g. In addition, it is substantially difficult to obtain a specific surface area A of less than 0.2 m ² /g. In addition, the specific surface area of this spherical silica was obtained by the BET method based on the use of a specific surface area and pore distribution measuring device (for example, "BELSORP-miniIII" manufactured by Microtrac BEL, "BELSORP-miniIII" manufactured by Micromeritics Corporation, " TriStar II", etc.) nitrogen adsorption method.

The true sphericity of the spherical silicon oxide is preferably 0.75~1.0. When the sphericity becomes low, the specific surface area becomes large, so the sphericity is preferably 0.75 or more in order to make it easier to increase the dielectric tangent. The true sphericity is preferably 0.90 or more, more preferably 0.93 or more, and the closer to 1.0, the better. In addition, true sphericity can be expressed by calculating the average value of the ratio (DS/DL) of the smallest diameter (DS) to the largest diameter (DL). The measurement of the largest diameter (DL) and the smallest diameter (DS) is as follows: For any 100 particles in the photographic projection image captured by a scanning electron microscope (SEM), measure the individual maximum diameter (DL) and short diameter (DS) orthogonal to it.

The dielectric tangent of the spherical silicon oxide is preferably 0.0020 or less at a frequency of 1 GHz, preferably 0.0010 or less, and more preferably 0.0008 or less. If the above-mentioned dielectric tangent is 0.0020 or less, an excellent dielectric loss suppression effect can be obtained, so a substrate or sheet with improved high-frequency characteristics can be obtained. Since the smaller the dielectric tangent is, the lower the transmission loss of the circuit can be suppressed, so the lower limit value is not particularly limited. In addition, the dielectric tangent can be measured using a dedicated device (for example, using "Vector Network Analyzer E5063A" manufactured by KEYCOM Co., Ltd.) and using the perturbation method resonator method (measurement conditions: test frequency 1GHz, test temperature about 24°C, The humidity is about 45%, and the number of measurements is 3 times).

The present spherical silica is preferably spherical silica whose viscosity of the kneaded product containing spherical silica measured by the following measurement method is 5000 mPa·s or less. Measurement method: Mix 6 parts by mass of cooked linseed oil and 8 parts by mass of spherical silica according to JIS K 5421:2000, and knead at 2000rpm for 3 minutes to obtain a kneaded product. 1s ^-1 Measure the kneaded product for 30 seconds, and obtain the viscosity at 30 seconds.

The IR peak intensity around 3746 cm ^-1 originating from isolated silanol groups on the surface of the spherical silicon oxide is preferably less than 0.1, preferably less than 0.08, more preferably less than 0.06. The isolated silanol group refers to a silanol (Si—OH) group not bonded to water or the like adsorbed on the silicon oxide particles. The amount of isolated silanol (Si-OH) on the surface of silicon oxide particles is obtained by IR measurement. Specifically, after standardizing the IR spectrum at 800 cm ^-1 and aligning the baselines at 3800 cm ^-1 , the relative value of the Si-OH peak intensity around 3746 cm ^-1 was calculated. If the IR peak intensity around 3746 cm ^-1 originating from the isolated silanol group on the spherical silicon oxide surface is below 0.1, the dielectric loss can be reduced.

Also, the maximum IR peak intensity at 3300-3700 cm ^-1 originating from bonded silanol groups on the surface of the spherical silica is preferably 0.2 or less, preferably 0.17 or less, and more preferably 0.15 or less. The bonded silanol group refers to a silanol (Si-OH) group bonded to water adsorbed on silicon oxide particles or silanol on the surface of silicon oxide. The amount of bonded silanol (Si-OH) on the surface of silicon oxide particles is obtained by IR measurement. Specifically, after standardizing the IR spectrum at 800 cm ^-1 and aligning the baselines at 3800 cm ^-1 , the relative value of the bonded Si-OH peak intensity was calculated from the maximum peak at 3300 to 3700 cm ^-1 . If the maximum IR peak intensity at 3300~3700cm ^-1 originating from bonded silanol groups on the surface of the spherical silicon oxide is less than 0.2, the dielectric loss can be reduced. In addition, the measurement of infrared spectroscopy (IR) spectrum can be performed, for example, by using IR Prestige-21 (manufactured by Shimadzu Corporation), dispersing spherical silicon oxide powder in diamond, and performing the diffuse reflectance method (example of measurement conditions: measurement range 400 ~4000cm ^-1 , resolution 4cm ^-1 , cumulative times 128 times). The dilution of diamond powder is defined as [mass dilution rate]=([sample mass])/([diamond mass]+[sample mass]), so that [mass dilution rate]=85-2.5×[BET ratio surface area].

From the viewpoint of electrical properties such as dielectric tangent and physical properties such as viscosity of the present composition, the present spherical silica is preferably non-porous particles. Specifically, the oil absorption of the spherical silica is preferably less than 100ml/100g, more preferably less than 70ml/100g, most preferably less than 50ml/100g.

Titanium (Ti) contained in the spherical silicon oxide is preferably contained within the range of 30-1500 ppm, more preferably contained within the range of 100-1000 ppm, more preferably contained within the range of 100-500 ppm.

The present spherical silicon oxide may further contain other elements. Examples of other elements include: Na, K, Mg, Ca, Al, Fe. The total content of alkali metals and alkaline earth metals in other elements is preferably less than 2000ppm, more preferably less than 1000ppm, more preferably less than 200ppm.

The spherical silica can also be treated with silane coupling agent. By using a silane coupling agent to treat the surface of the spherical silicon oxide, the residual amount of silanol groups on the surface will be reduced, the surface will be hydrophobized, and the dielectric loss will be increased by inhibiting moisture adsorption, and the affinity with F polymer will be improved. , dispersibility, or the strength of molded products such as polymer layers obtained from this composition is improved. Examples of silane coupling agents include: aminosilane-based coupling agents, epoxy-based silane-based coupling agents, mercaptosilane-based coupling agents, organic silazane compounds, and the like. These can also use 2 or more types together. The attachment amount of the silane coupling agent is preferably set to an amount at which all the silanol groups existing on the surface of the spherical silica can react. Specifically, it is preferably at least 0.01 parts by mass, more preferably at least 0.05 parts by mass, and preferably at most 2 parts by mass, more preferably at most 1 part by mass, based on 100 parts by mass of the present spherical silica.

The present spherical silicon oxide is preferably spherical silicon oxide obtained by heat-treating a spherical silicon oxide precursor formed by a wet method. The wet method refers to a method including the following steps: a step of obtaining a raw material of spherical silicon oxide powder by using a liquid as a silicon oxide source and gelling it. Wet methods include, for example, spray methods, emulsion and gelation methods, and the like.

The pore volume of the spherical silicon oxide precursor obtained by the wet method is preferably 0.3-2.2ml/g. Here, the pore volume is obtained by the BJH method based on the use of a specific surface area and pore distribution measuring device (for example, "BELSORP-miniIII" manufactured by Microtrac BEL, "TriStar II" manufactured by Micromeritics, etc.) The nitrogen adsorption method. The loss on ignition of the silicon oxide precursor obtained by the wet method is preferably 5.0-15.0% by mass. Here, the loss on ignition is determined as the mass loss after heating and drying 1 g of the silicon oxide precursor at 850° C. for 0.5 hours in accordance with JIS K0067.

During the heat treatment, the spherical silicon oxide powder is densified to refine the shell and at the same time reduce the amount of silanol groups on the surface to lower the dielectric tangent. The temperature of heat treatment should be 700~1600℃. The aforementioned heat treatment methods include, for example: heat treatment by standing still, heat treatment by rotary kiln, heat treatment by spray combustion, etc.

The surface of the spherical silicon oxide obtained by the method described above can also be treated with a silane coupling agent, so that the silanol groups present on the surface of the spherical silicon oxide can react with the silane coupling agent. As the silane coupling agent, the above-mentioned compounds may be mentioned, and two or more types may be used in combination. The treatment amount of the silane coupling agent is preferably 0.01 to 5 parts by mass relative to 100 parts by mass of the present spherical silicon oxide. The method of surface treatment with silane coupling agent can be, for example, the dry method of spraying the silane coupling agent on the spherical silicon oxide, or the wet method of dispersing the spherical silicon oxide in a solvent and then adding the silane coupling agent to react.

The liquid dispersion medium contained in the composition is a liquid capable of dissolving, dispersing, or gelling the F particles or the spherical silicon oxide, and the composition is usually in the form of slurry or gel. In addition, liquid means that the viscosity at 25°C is 10 mPa･s or less. From the viewpoint of making the distribution of the present spherical silica uniform in the polymer layer constituting the laminate described later and suppressing voids, the liquid dispersion medium is preferably degassed.

The liquid dispersion medium may be water or a non-aqueous dispersion medium. In addition, the liquid dispersion medium may be an aprotic dispersion medium or a protic dispersion medium. The liquid dispersion medium is a compound that is liquid at 25°C under atmospheric pressure, such as water, alcohol, amide, ketone and ester. Examples of the alcohol include methanol, ethanol, isopropanol, and glycols (ethylene glycol, propylene glycol, 1,3-propanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, etc.). Examples of amides include: N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylacrylamide, 3 -Methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide, N,N-diethylformamide, hexamethyl triamide phosphate, 1,3-dimethyl-2-imidazolidinone, etc. Examples of ketones: acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, methyl n-amyl ketone, methyl isoamyl ketone, 2-heptanone, cyclopentanone, cyclopentanone, Hexanone, Cycloheptanone. Examples of esters include: methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, methyl pyruvate, ethyl pyruvate, methyl methoxy propionate, ethyl ethoxy propionate, Ethyl 3-ethoxypropionate, gamma-butyrolactone, gamma-valerolactone.

The liquid dispersion medium may use 2 or more types together. When two or more types are used together, it is better that the liquid dispersion media of different types are compatible. The boiling point of the liquid dispersion medium should be within the range of 50~240°C. The content of the liquid dispersion medium in the composition is preferably at least 5% by mass, preferably at least 20% by mass, and more preferably at least 40% by mass, relative to the overall mass of the composition. The content of the liquid dispersion medium is preferably not more than 80% by mass, preferably not more than 70% by mass. Within the above range, the present composition can be handled as a dispersion liquid or a paste, and its dispersion stability and applicability can be improved more easily.

The content of F particles in this composition is preferably at least 10% by mass, preferably at least 20% by mass, relative to the overall mass of this composition. From the viewpoint of the dispersion stability of the composition, the content of the F particles is preferably 40% by mass or less, preferably 30% by mass or less, based on the overall mass of the composition. The content of the spherical silicon oxide in the composition is preferably at least 10% by mass, preferably at least 20% by mass, relative to the overall mass of the composition. From the viewpoint of the dispersion stability of the composition, the content of the spherical silica is preferably 60% by mass or less, preferably 50% by mass or less, based on the overall mass of the composition.

Also, relative to the overall mass of this composition, the content of the spherical silicon oxide is 10-60% by mass, preferably in the range of 20-50% by mass, and the content of F particles is 10-40% by mass, preferably 10% by mass. ~30% by mass. Furthermore, the content of the spherical silicon oxide in the present composition is preferably higher than the content of the F particles. If it is within the above-mentioned range, it is easy to obtain the present composition which suppresses the increase in viscosity without losing excellent dispersion stability, and it is easy to form a polymer layer with any thickness, especially a thick polymer layer, from this composition.

The total content of the F particles and the spherical silicon oxide in this composition is preferably at least 20% by mass, preferably at least 50% by mass, based on the overall mass of the composition. The total content of the F particles and the spherical silicon oxide is preferably not more than 95% by mass, preferably not more than 75% by mass, relative to the overall mass of the composition.

As required, this composition may further contain an inorganic filler other than the spherical silica. The aforementioned inorganic fillers are different from the spherical silica fillers, for example: boron nitride fillers, aluminum nitride fillers, beryllium oxide fillers, silicate fillers (silicon oxide fillers, wollastonite fillers, talc fillers), Metal oxide (cerium oxide, aluminum oxide, magnesium oxide, zinc oxide, titanium oxide, etc.) filler and magnesium metasilicate (talc) filler. The fillers may also be fired ceramic fillers. The aforementioned inorganic filler can also be surface-treated with a silane coupling agent on at least a part of its surface. The surface-treated inorganic filler has excellent affinity with the F particles, and it is easy to improve the dispersibility of the composition.

From the viewpoint of further improving dispersion stability and handleability, this composition may further contain a surfactant. The surfactant is preferably nonionic. The hydrophilic portion of the surfactant preferably has an oxyalkylene group or an alcoholic hydroxyl group. The hydrophobic part of the surfactant preferably has an ethynyl group, a polysiloxane group, a perfluoroalkyl group or a perfluoroalkenyl group. In other words, the surfactant is preferably an acetylene-based surfactant, a polysiloxane-based surfactant or a fluorine-based surfactant, and a polysiloxane-based surfactant is more preferred.

Specific examples of the surfactant include: "Ftergent (registered trademark)" series (manufactured by NEOS Co., Ltd.), "Surflon (registered trademark)" series (manufactured by AGC Seimi Chemical), "Megafac (registered trademark)" Series (manufactured by DIC Co., Ltd.), "UNIDYNE (registered trademark)" series (manufactured by DAIKIN Industry Co., Ltd.), "BYK-347", "BYK-349", "BYK-378", "BYK-3450", "BYK -3451", "BYK-3455", "BYK-3456" (manufactured by BYK Japan Co., Ltd.), "KF-6011", "KF-6043" (manufactured by Shin-Etsu Chemical Industry Co., Ltd.), "Tergitol" series (manufactured by Dow Chemical Company system, "Tergitol TMN-100X", etc.). When the composition contains a surfactant, the amount is preferably in the range of 1 to 15% by mass of the composition. At this time, the affinity between the components is enhanced, and the dispersion stability and handleability of the composition are more easily improved.

The present composition may further include an aromatic polymer. Aromatic polymers may be thermoplastic or thermosetting. Aromatic polymers can also be contained in the composition in the form of their precursors. The aromatic polymer may be contained in the present composition in the form of particles, or may be dissolved in a liquid dispersion medium. When the present composition contains water, the aromatic polymer is preferably water-soluble.

Examples of aromatic polymers include: aromatic polyimide, aromatic polyimide precursor (polyamic acid or its salt), aromatic polyamide imide, aromatic polyamide imide precursor Aromatic polyetherimide, aromatic polyetherimide precursor, aromatic sulfide resin, aromatic sulfide resin, phenolic resin, aromatic epoxy resin, aromatic polyester resin (liquid crystal aromatic polyester, etc.), aromatic polyester amide (liquid crystalline aromatic polyester amide, etc.), aromatic maleimide, polyphenylene ether, preferably aromatic polyimide precursor, Aromatic polyamide imide and aromatic polyamide imide precursor. In this case, the aromatic polymer is likely to interact with the F polymer, and even the molded article formed of this composition tends to have excellent adhesion to substrates such as metal foils or UV absorption. When the composition contains water, it is preferably a water-soluble aromatic polyimide precursor and a water-soluble aromatic polyimide precursor.

Examples of the aromatic polyimide precursor include polyamic acid in which tetracarboxylic dianhydride and diamine are polymerized in a solvent, or polyamic acid salt in which the polyamic acid is reacted with ammonia water or organic amine. Specific examples of aromatic polyimides or their precursors include: "Neopulim (registered trademark)" series (manufactured by Mitsubishi Gas Chemical Co., Ltd.), "SPIXAREA (registered trademark)" series (manufactured by SOMAR Corporation), "Q-PILON (registered trademark)” series (manufactured by PIRD Technology Research Institute), “WINGO” series (manufactured by WINGO TECHNOLOGY Co., Ltd.), “Tomaido (registered trademark)” series (manufactured by T&K TOKA Co., Ltd.), “KPI-MX” series (manufactured by Kawamura Sangyo Co., Ltd. Manufactured), "UPIA (registered trademark)-AT" series (manufactured by Ube Industries, Ltd.).

Examples of aromatic polyamide imides or their precursors include polyamide imides obtained by reacting diisocyanates and/or diamines with tribasic acid anhydrides (or tribasic acid chlorides) as acid components Resins or their precursors. Specific examples of aromatic polyamideimide or its precursor include "HPC-1000" and "HPC-2100D" (manufactured by Showa Denko Materials Co., Ltd. above).

When the composition further contains an aromatic polymer, the content thereof is preferably at least 0.01% by mass, preferably at least 1% by mass, based on the overall mass of the composition. The content of the aromatic polymer is preferably not more than 5% by mass, more preferably not more than 3% by mass. The content of the aromatic polymer in the composition is preferably less than 10% by mass, preferably 5% by mass or less, relative to the content of the F polymer in the composition. The content of the aromatic polymer is preferably 0.1% by mass or more relative to the content of the F polymer. When the composition contains an aromatic polymer, the aromatic polymer can function as a dispersant or binder between the spherical silica and the F polymer, and it is easy to form a dense polymer layer, and the spherical silica is easy to Highly dispersed in the polymer layer. As long as the content of the aromatic polymer is within the low range mentioned above, the electrical characteristics of the polymer layer are easy to be excellent.

In addition to inorganic fillers, surfactants, and aromatic polymers, the composition may further contain: thixotropy-imparting agents, viscosity regulators, defoamers, silane coupling agents, dehydrating agents, plasticizers, weather-resistant agents, Additives such as oxidizing agent, heat stabilizer, slip agent, antistatic agent, whitening agent, coloring agent, conductive agent, release agent, surface treatment agent, flame retardant, etc.

The viscosity of this composition should be above 10mPa･s, preferably above 50mPa･s. The viscosity of this composition is preferably below 10000mPa･s, preferably below 1000mPa･s, more preferably below 500mPa･s. The viscosity of this composition should be in the range of 50~1000mPa･s. In this case, since this composition is excellent in applicability, it is easy to form a molded article such as a polymer layer having an arbitrary thickness from this composition. The thixotropic ratio of this composition is preferably 1 or more. The thixotropic ratio of the composition is preferably 3 or less, preferably 2 or less. In this case, this composition is not only excellent in coatability, but also excellent in homogeneity, so it is easy to form molded objects such as finer polymer layers.

This composition can be produced by mixing F particles, this spherical silicon oxide, and a liquid dispersion medium. The mixing method is not particularly limited as long as it is a method that can uniformly mix the F particles, the present spherical silicon oxide, the liquid dispersion medium, and other components according to the needs. Examples include: (a) adding each component at a time or sequentially And the method of mixing, (b) pre-mixing the F particles and the liquid dispersion medium, the spherical silicon oxide and the liquid dispersion medium respectively, and then further mixing the two obtained mixtures, (c) pre-mixing the F particles and the A method of making the spherical silicon oxide into a powder mixture, and then mixing the obtained powder mixture with a liquid dispersion medium, etc. The method of (b) or (c) above is preferable from the viewpoint that the obtained composition is easily homogeneous. In addition, when making this composition further contain inorganic fillers, surfactants, aromatic polymers, and other components that may be added arbitrarily, it is preferable to pre-mix the liquid dispersion medium, F particles, and the spherical silica before mixing. Add to liquid dispersion medium. When the present composition contains an aromatic polymer, it can also be mixed with F particles in a varnish form of the aromatic polymer. Examples of the solvent constituting the varnish include N-methyl-2-pyrrolidone, cyclohexanone, and toluene.

The mixing device used in order to obtain the composition includes: a stirring device equipped with a blade (Henschel mixer, pressurized kneader, Banbury mixer (Banbury mixer), planetary mixer (Planetary mixer), etc. ), milling devices with media (ball mill, attritor, basket mill, sand mill, sand grinder, dyno-mill, disperser , SC mill, spike mill or agitator mill, etc.), and dispersion devices with other mechanisms (microfluidizer, nanomizer, high-pressure homogenizer (ultimaizer, ultrasonic homogenizer, mixer (dissolver), disperser (disper), high-speed impeller, planetary centrifugal mixer, colloid mill, film rotary high-speed mixer, etc.).

In addition, the preferred production method of this composition may include the following production method: knead F particles, this spherical silicon oxide and a part of the liquid dispersion medium in advance to obtain a kneaded product, and then further add the remaining liquid dispersion medium to the aforementioned kneaded mixture and mixed to obtain the present composition. The liquid dispersion medium used for kneading and addition may be the same type of liquid dispersion medium, or may be a different type of liquid dispersion medium. When the composition further includes other components such as inorganic fillers, surfactants, and aromatic polymers, the other components may be mixed during kneading, or may be mixed when adding the remaining liquid dispersion medium to the kneaded mixture. When the F particles, the present spherical silica, and a part of the liquid dispersion medium are kneaded in advance, the mixing method of each component may be, for example, the method of (a), (b) or (c) above. The method of (b) or (c) above is preferable from the viewpoint that the obtained composition is easily homogeneous. Mixing during kneading is preferably carried out using a planetary mixer. A planetary mixer is a stirring device having two shaft stirring blades which rotate and revolve mutually. Mixing at the time of addition is preferably performed using a thin-film rotary type high-speed stirrer. The thin-film rotary high-speed mixer is a stirring device that rotates the F particles and the liquid dispersion medium along the inner wall surface of a cylindrical stirring tank to spread them into a thin film, and mixes them while exerting centrifugal force.

The kneaded product obtained by kneading can be paste (viscosity of 1000~100000mPa･s, etc.), or wet powder (viscosity of 10000~100000Pa･s measured by capillary rheometer (Capilograph) Wet powder (kneading powder), etc.). In addition, the viscosity measured by a capillary rheometer refers to the use of a capillary with a capillary length of 10mm and a capillary radius of 1mm, the furnace body diameter is 9.55mm, the load cell capacity is 2t, and the temperature is 25°C, The shear rate is 1s ^-1 to determine the value.

This composition is useful as a coating material for imparting insulation, heat resistance, corrosion resistance, chemical resistance, water resistance, impact resistance, and thermal conductivity. Specifically, this composition can be used in: printed wiring boards, thermal interface materials, substrates for power modules, coils used in power devices such as motors, automotive engines, heat exchangers, vial bottles, injection Cartridges (syringes), ampoules, medical wires, secondary batteries such as lithium-ion batteries, primary batteries such as lithium batteries, radical batteries, solar batteries, fuel cells, lithium-ion capacitors, hybrid capacitors, capacitors ), capacitors (condenser) (aluminum electrolytic capacitors, tantalum electrolytic capacitors, etc.), electrochromic components, electrochemical switching components, electrode binders, electrode separators, electrodes (positive and negative). Also, this composition is useful as an adhesive for bonding parts. Specifically, this composition can be used for: the bonding of ceramic parts, the bonding of metal parts, the bonding of IC chips or electronic components such as resistors and capacitors in the substrate of semiconductor elements or module parts, the bonding of circuit boards and heat sinks , Bonding of LED chip to substrate.

In particular, this composition is useful as a printed wiring board, specifically, as a material for a polymer layer in a copper foil for forming a polymer layer attached to a copper foil. The surface has a polymer layer formed from the composition. As shown in Table 1 below, spherical silicon oxide itself has excellent electrical properties (especially dielectric tangent) and low linear expansion, but it is difficult to make the polymer layer in the copper foil with the polymer layer attached. The physical properties are highly displayed. As long as the present composition is used, copper foil with a polymer layer attached to the polymer layer can be easily obtained through the above-mentioned mechanism. The polymer layer has the properties of the spherical silicon oxide and the F polymer.

[Table 1]

This composition is suitable for use as the following composition: by applying to at least one of the surfaces of the base material and heating, the polymer layer (hereinafter also referred to as "F layer") comprising the F polymer and the present spherical silicon oxide is suitably used. ”) formed composition. For example, this composition is given to the surface of the substrate to form a liquid film (wet film) composed of this composition, and then heated to remove the liquid dispersion medium from the liquid film, and the composition containing F can be formed on the surface of the substrate. Polymer and the polymer layer of the spherical silica. It is preferable to further calcinate the F polymer of the obtained polymer layer. As long as the F polymer is fired by heating, a laminate having a substrate layer and a polymer layer can be manufactured. The polymer layer is located on the surface of the substrate layer and includes the fired F polymer and the spherical silicon oxide. In addition, the heating for removing the liquid medium and the heating for firing the F polymer can be performed continuously.

Substrates include metal substrates such as copper, nickel, aluminum, titanium and their alloys and other metal foils; tetrafluoroethylene-based polymers, polyimides, polyarylates, polystyrene, polyallyl foil ( Polyallyl sulfone), polyamide, polyetheramide, polyphenylene sulfide, polyallyl ether ketone, polyamide imide, liquid crystalline polyester, liquid crystalline polyester amide and other heat resistant resins Resin films; prepregs that are precursors of fiber-reinforced resin substrates; ceramic substrates such as silicon carbide, aluminum nitride, and silicon nitride; and glass substrates. The shape of the substrate can be flat, curved, or concave-convex. In addition, the shape of the base material may be any of foil shape, plate shape, film shape, and fiber shape.

The ten-point average roughness of the substrate surface should be less than 0.1 μm, preferably less than 0.05 μm. The aforementioned ten-point average roughness is preferably not less than 0.001 μm. Even if it is the said non-roughened base material, as long as the polymer layer excellent in uniformity can be obtained according to this method, the laminated body excellent in peel strength can be obtained. In addition, the ten-point average of the substrate surface is a value specified in Appendix JA of JIS B 0601:2013. The thickness of the base material is preferably 2-100 μm. When the base material is metal foil, the thickness of the base material is preferably 1-35 μm. In addition, the base material may be a copper foil with a carrier, which is an ultra-thin copper foil (thickness 2 to 5 μm) laminated on a carrier copper foil via a release layer. When the base material is a polyimide film, the thickness of the base material is preferably 10-50 μm.

In order to further improve the low linear expansion and adhesiveness of the laminate, the outermost surface of the substrate can be further surface treated. Surface treatment methods include: annealing treatment, corona treatment, plasma treatment, ozone treatment, excimer treatment, silane coupling agent treatment. The annealing conditions should be temperature 120~180°C, pressure 0.005~0.015MPa, and time 30~120 minutes. Examples of gases used in plasma treatment include oxygen, nitrogen, rare gases (argon, etc.), hydrogen, ammonia, and vinyl acetate. These gases may be used in combination of two or more.

The method of applying this composition to the surface of the substrate may be any method as long as it can form a stable liquid film (wet film) composed of this composition on the surface of the substrate, and examples include coating methods, droplet discharge methods, The dipping method is preferably a coating method. As long as the coating method is used, a liquid film can be efficiently formed on the surface of the metal substrate with simple equipment. Coating methods include: spray coating, roll coating, spin coating, gravure coating, micro gravure coating, gravure flat plate, doctor blade coating, contact coating, rod coating, die coating, Fountain Meyer bar coating (fountain meyer bar) method, slot die coating method.

The F layer is preferably formed by heating to a high temperature to burn the polymer after removing the liquid dispersion medium from the liquid film (wet film) by heating. The removal temperature of the liquid dispersion medium should be as low as possible, preferably 50~150°C lower than the boiling point of the liquid dispersion medium. For example, when N-methyl-2-pyrrolidone having a boiling point of about 200°C is used, it should be heated at 150°C or lower, preferably 100 to 120°C. In the step of removing the liquid dispersion medium, air may be blown to facilitate the removal of the liquid dispersion medium by air drying. During the heating at this time, the liquid dispersion medium does not necessarily have to be completely removed, and it is only necessary to remove until the layer formed by the accumulation of F particles can maintain a self-supporting film (Self-supporting film).

After removing the liquid dispersion medium, it is advisable to heat the polymer layer on the substrate to the temperature range where the F polymer is fired to form the F layer containing the fired product of the F polymer, for example, it is preferably in the range of 300~400°C Firing F polymer. The F layer preferably contains a fired product of the F polymer. The heating device in each heating can be an oven and a ventilated drying furnace. The heat source in the device can be a contact heat source (hot air, hot plate, etc.), or a non-contact heat source (infrared rays, etc.). Each heating may be performed under normal pressure or under reduced pressure. The gas environment in each heating can also be any one of air environment, inert gas (helium, neon, argon, nitrogen, etc.) gas environment. The F layer is formed through the steps of applying this composition to the surface of the substrate and heating. For the purpose of obtaining a thick F layer, the application and heating of the present composition may be repeated multiple times to form the F layer. For example, this composition may be applied to the surface of the base material and heated to form the F layer, and further this composition may be applied to the surface of the F layer and heated to form the second layer F layer. In addition, in the step of applying the present composition to the surface of the substrate and heating to remove the liquid dispersion medium, the F layer may be formed by further applying the present composition to the surface and heating.

The thickness of the F layer is preferably at least 50 μm, preferably at least 100 μm. The thickness of the F layer is preferably 1000 μm or less. Even when the F layer is relatively thick, the polymer layer with excellent dispersibility of the spherical silica can still be obtained through the above mechanism.

The peel strength between the F layer and the substrate layer should be above 10N/cm, preferably above 15N/cm. The aforementioned peel strength is preferably 100 N/cm or less. In addition, the tensile strength of the F layer is preferably 5 MPa or more, preferably 10 MPa or more. The aforementioned tensile strength is preferably 100 MPa or less. By using this composition, it is possible to easily form a laminate excellent in the peel strength between the F layer and the substrate layer and the tensile strength of the F layer without impairing the physical properties of the F polymer in the F layer.

The composition may be applied to only one surface of the substrate, or may be applied to both surfaces of the substrate. In the former case, a laminate having a substrate layer and an F layer located on a single surface of the substrate layer can be obtained, and in the latter case, a laminate having a substrate layer and an F layer positioned on both surfaces of the substrate layer can be obtained. A laminate of F layers on the surface. A preferred specific example of the laminate can be mentioned: a metal clad laminate having a metal foil and an F layer positioned on at least one surface of the metal foil; Multilayer film of F layers on both surfaces. Since these laminates are excellent in various physical properties such as electrical characteristics, they are suitable as materials for printed circuit boards and the like, and can be used in the manufacture of flexible printed circuit boards or rigid printed circuit boards.

Other substrates may be further laminated on the outermost surface of the laminate. Examples of other substrates include metal substrates, heat-resistant resin films, prepregs that are precursors of fiber-reinforced resin boards, laminates with heat-resistant resin films, and laminates with prepreg layers. Examples of the metal substrate include the above-mentioned metal substrates. The heat-resistant resin film is a film containing one or more heat-resistant resins, and examples of the heat-resistant resin include the above-mentioned resins. Furthermore, the base material can also be removed from a laminated body. In this case, a film composed of a single F layer can be obtained.

Laminates, laminates of laminates and other substrates, and films composed of F layers are used as antenna parts, printed substrates, aircraft parts, automotive parts, sports equipment, food industry supplies, paints, cosmetics, etc. Specifically, it can also be suitably used as the following examples: wire covering materials (aircraft wires, etc.), enameled wire covering materials used in motors such as electric vehicles, electrical insulating tapes, insulating tapes for oil drilling, materials for printed circuit boards , separation membrane (precision filtration membrane, ultrafiltration membrane, reverse osmosis membrane, ion exchange membrane, dialysis membrane, gas permeation membrane, etc.), electrode binder (for lithium secondary battery, fuel cell, etc.), copy roll (copy roll ), furniture, automotive dashboards, housings for home appliances, sliding components (load bearings, sliding shafts, valves, bearings, bushings, seals, thrust washers, wear-resistant parts, pistons, sliding Switches, gears, cams, belt conveyors, food conveyor belts, etc.), wear pads, wear strips, tube lights, test sockets, wafer guides, wear parts of centrifugal pumps, hydrocarbon/pharmaceutical and water supply pumps , tools (shovels, files, awls, saws, etc.), boilers, hoppers, pipe fittings, ovens, baking molds, chutes, molds, toilets, container covering materials, power components, transistors, thyristors , commutators, transformers, power MOS FETs, CPUs, heat sinks, metal radiators, blades of windmills or wind power generation equipment or aircraft, heat dissipation substrates for automobiles, wireless communication devices (for example, International Publication No. 2020/008691 and the heat dissipation member of the wireless communication device described in International Publication No. 2020/031419).

The composition, the method for producing the composition, the method for producing a laminate having a polymer layer formed of the composition, and the laminate have been described above, but the present invention is not limited to the configurations of the above embodiments. . For example, this composition and the above-mentioned laminate may add other arbitrary structures to the structure of the above-mentioned embodiment, and may replace it with the arbitrary structure which can exhibit the same function. In addition, the manufacturing method of this composition and the manufacturing method of the said laminated body may add other arbitrary steps in the structure of the said embodiment, and may replace with the arbitrary steps which produce the same effect. Example

Hereinafter, the present invention will be described in detail by means of examples, but the present invention is not limited thereto. 1. Preparation of each component [F particle] F particle 1: a particle (D50: 2.1 μm) composed of F polymer 1, the F polymer 1 is 97.9 mol%, 0.1 mol%, 2.0 mol% Contains TFE unit, NAH unit and PPVE unit in sequence, fluorine content is 76% by mass, and has 1000 carbonyl-containing groups relative to 1×10 ⁶ carbons per main chain. F particle 2: a particle (D50: 2.5 μm) composed of F polymer 2, the F polymer 2 contains TFE unit and PPVE unit in order of 97.5 mole % and 2.5 mole %, and the fluorine content is 76 mass %, and relative to 1×10 ⁶ carbons per main chain, the number of carbonyl-containing groups is less than 25. [Spherical silica] Spherical silica 1: Silica powder ("H-31" manufactured by AGC Si-Tech Co., Ltd., median diameter d = 3.5 μm, Ti content 300 ppm) produced by a wet method was prepared at 1300 Spherical silicon oxide powder after heat treatment at ℃ for 1 hour (median particle size d=3μm, specific surface area 1.3m ² /g) Spherical silicon oxide 2: Spherical silicon oxide produced from raw material silicon oxide by VMC method Silicon ("SC-04" manufactured by Admatechs Co., Ltd., median particle size d=1.5 μm, specific surface area 4.5 m ² /g, Ti content 28 ppm) spherical silicon oxide 3: median particle size d=0.6 μm, specific surface area 6.2 m ² /g of spherical silica [liquid dispersion medium] NMP: N-methylpyrrolidone [surfactant] Surfactant 1: non-ionic surfactant (Ftergent710FL)

2. Production example of liquid composition [example 1] Obtained by kneading 25 parts by mass of F particles 1, 50 parts by mass of spherical silicon oxide 1, 5 parts by mass of surfactant 1, and 20 parts by mass of NMP with a self-rotating and revolving mixer (defoaming Rentaro, manufactured by THINKY Co., Ltd.) 55 parts by mass of NMP was further added to the pasty kneaded mixture and stirred at 2000 rpm for 5 minutes to obtain a liquid composition 1 . The viscosity of the obtained liquid composition 1 is less than 100mPa･s. [Example 2] Liquid composition 2 was obtained in the same manner as in Example 1 except that 50 parts by mass of spherical silicon oxide 2 was used instead of 50 parts by mass of spherical silicon oxide 1 . The viscosity of the obtained liquid composition 2 is greater than 100 mPa·s. [Example 3] Liquid composition 3 was obtained in the same manner as in Example 1, except that 50 parts by mass of spherical silicon oxide 3 was used instead of 50 parts by mass of spherical silicon oxide 1 . The viscosity of the obtained liquid composition 3 is greater than 100 mPa·s. [Example 4] Liquid composition Liquid composition 4 was obtained in the same manner as in Example 1, except that 25 parts by mass of F particle 2 was used instead of 25 parts by mass of F particle 1 . The viscosity of the obtained liquid composition 4 is less than 100mPa·s.

3. Manufacturing example of laminated body [Example 4] The liquid composition 1 was applied on the surface of copper foil (thickness: 18 μm) to form a wet film. Next, the metal foil on which the wet film was formed was passed through a drying oven at 120° C. for 5 minutes, and dried by heating to obtain a dry film. Afterwards, the dry film was heated at 380° C. for 3 minutes in a nitrogen oven. In this way, a laminate 1 of copper foil with a polymer layer is produced. The copper foil with a polymer layer has a copper foil and a polymer layer (thickness: 50 μm) as a molded product. The polymer layer is located on the copper foil. The surface also contains F polymer and spherical silicon oxide 1 . [Example 5~7] In the same manner as in Example 4, except for changing the liquid composition used, laminate 2 was obtained from liquid composition 2 (Example 5), laminate 3 was obtained from liquid composition 3 (Example 6), and laminate 3 was obtained from liquid composition 3 (Example 6). Laminated body 4 was obtained from composition 4 (Example 7).

4. Evaluation 4-1. Dispersion stability of liquid composition After each liquid composition was left to stand at 25° C. for 30 days, the dispersion state was observed visually, and the long-term dispersion stability was evaluated based on the following criteria. The results are shown in Table 2. ＜Evaluation criteria＞ 〇: Viscosity is not increased and component sedimentation is not confirmed △: Although layer separation can be confirmed, it can be easily redispersed, and viscosity increase after redispersion is not confirmed. ×: Viscosity increase or component sedimentation can be confirmed

[Table 2]

4-2. Evaluation example of laminated body As a result of visually confirming the surface of the polymer layer in each laminate, the order of smoothness was laminate 1, laminate 4, laminate 3, and laminate 2 in descending order. In addition, for each laminate, the copper foil was removed by etching with an aqueous solution of ferric chloride to obtain a separate polymer layer, and a 180 mm square test piece was cut out, and the linear expansion coefficient was measured according to JIS C 6471: 1995. As a result of measuring the linear expansion coefficient, the order of the linear expansion coefficient from low to high is the polymer layer of laminate 1, the polymer layer of laminate 4, the polymer layer of laminate 3, and the polymer layer of laminate 2. Furthermore, as a result of measuring the dielectric tangent of each polymer layer by SPDR (Split Post Dielectric Resonator: split post dielectric resonator method, measurement frequency: 10 GHz), the dielectric tangent of the polymer layer of laminate 1 is the lowest.

4. Example of film production [Example 8] Except that the thickness of the polymer layer as a molding was 150 μm, copper foil with a polymer layer was produced from each liquid composition in the same manner as in Example 4, and the copper foil was further etched away to produce a separate film. The surface smoothness of the obtained film was the highest for the film formed from the liquid composition 1.

Industrial availability According to the present invention, a liquid composition with excellent uniformity and dispersion stability and low viscosity can be obtained. A laminate obtained from this liquid composition has excellent electrical properties such as low dielectric tangent, and can be suitably used as a material for a printed wiring board, for example. In addition, all contents of the specification, scope of claims and abstract of Japanese Patent Application No. 2021-193907 filed on November 30, 2021 are cited here, and incorporated as the disclosure of the specification of the present invention.

(none)

Claims (15)

A liquid composition comprising: tetrafluoroethylene-based polymer particles; spherical silicon oxide, wherein the median particle diameter d (μm) is greater than 0.6 μm and not more than 20 μm, and the aforementioned median particle diameter d and specific surface area A (m ² /g), the product d×A is 2.7~5.0μm･m ² /g; and a liquid dispersion medium. The liquid composition according to claim 1, wherein the tetrafluoroethylene polymer is a hot-melt tetrafluoroethylene polymer. The liquid composition according to claim 1 or 2, wherein the aforementioned tetrafluoroethylene-based polymer is a tetrafluoroethylene-based polymer having oxygen-containing polar groups, which contains units mainly composed of perfluoro(alkyl vinyl ether) . The liquid composition according to any one of claims 1 to 3, wherein the specific surface area of the aforementioned spherical silicon oxide is 0.2~2.0m ² /g. The liquid composition according to any one of claims 1 to 4, wherein the maximum IR peak intensity at 3300-3700 cm ^-1 derived from bonded silanol groups on the surface of the spherical silicon oxide is 0.2 or less. The liquid composition according to any one of Claims 1 to 5, wherein the content of the spherical silicon oxide is 10 to 60% by mass relative to the entire mass of the liquid composition, and the tetrafluoroethylene-based polymer particles are The content is 10 to 40% by mass, and the content of the aforementioned liquid dispersion medium is 5% by mass or more. The liquid composition according to any one of claims 1 to 6, wherein the content of the aforementioned spherical silicon oxide is larger than the content of the aforementioned tetrafluoroethylene-based polymer particles. The liquid composition according to any one of claims 1 to 7, further comprising a surfactant. The liquid composition according to any one of claims 1 to 8, further comprising an aromatic polymer. The liquid composition according to any one of claims 1 to 9, further comprising an inorganic filler different from the aforementioned spherical silica. The liquid composition according to any one of Claims 1 to 10 has a viscosity of 50~1000mPa･s. A method for producing the liquid composition according to any one of claims 1 to 11, comprising mixing the tetrafluoroethylene-based polymer particles, the spherical silicon oxide, and the liquid dispersion medium to obtain the liquid composition. A method for producing a liquid composition is to manufacture the liquid composition according to any one of claims 1 to 11, the method is as follows: Kneading a composition containing the aforementioned tetrafluoroethylene-based polymer particles, the aforementioned spherical silica, and a part of the aforementioned liquid dispersion medium to obtain a kneaded product, and further adding the remaining aforementioned liquid dispersion medium to the aforementioned kneaded material and mixing to form The aforementioned liquid composition was obtained. A method for manufacturing a laminate, which is to apply the liquid composition according to any one of Claims 1 to 11 on the surface of the substrate to form a liquid film composed of the aforementioned liquid composition, and then heat the The film removes the liquid dispersion medium, and forms a polymer layer comprising the tetrafluoroethylene-based polymer and the spherical silicon oxide on the surface of the substrate. A laminate comprising: substrate; and The polymer layer, which is provided on the surface of the aforementioned substrate and is formed of the liquid composition according to any one of claims 1 to 11, includes a tetrafluoroethylene polymer and the aforementioned spherical silicon oxide.