TW201641565A - Polytetrafluoroethylene oil-based solvent type dispersion, epoxy resin composition containing polytetrafluoroethylene and the cured material thereof - Google Patents

Abstract

There is provided an oily solvent-based dispersion of polytetrafluoroethylene containing polytetrafluoroethylene having specific surface area of 15 m2/g or less and a fluorine-based additive containing at least a fluorine-based group and a lipophilic group of 0.1 to 50 mass% based on the polytetrafluoroethylene. To provide a polytetrafluoroethylene-containing epoxy resin composition having low dielectric constant and low dielectric loss tangent suitable for an electronic substrate material, an insulation material, an adhesive material or the like by using an epoxy resin composition containing an oily solvent-based dispersion of polytetrafluoroethylene excellent in dispersibility and a cured article thereof.

Description

Polytetrafluoroethylene oil-based solvent dispersion and polytetrafluoroethylene-containing epoxy resin composition, and cured product thereof

The present invention relates to an oil-based solvent dispersion of polytetrafluoroethylene (hereinafter, a case where polytetrafluoroethylene is abbreviated as "PTFE"), and further relates to a PTFE-containing epoxy resin composition and a cured product thereof. More specifically, the oil-based solvent dispersion of PTFE having excellent micro-particle size dispersibility, and the PTFE-containing ring suitable for low dielectric constant and low dielectric tangent of electronic substrate materials, insulating materials, and subsequent materials. An oxy-resin composition, and a cured product thereof.

PTFE is excellent in heat resistance, electrical insulation properties, low dielectric properties, low friction properties, non-adhesive properties, weather resistance, etc., and is used in electronic devices, sliders, automobiles, kitchens, and the like. The PTFE having such characteristics is added as a fine powder to various resin materials (photoresist materials) or rubbers, adhesives, lubricants or oil esters, printing inks, paints, and the like for the purpose of improving the properties of the products.

Such a fine powder of PTFE is usually obtained by emulsion polymerization in the presence of a stabilizer such as water, a polymerization initiator, a fluorine-containing emulsifier, or a paraffin wax. After the fluoroethylene (TFE) monomer is polymerized and obtained as an aqueous dispersion containing PTFE fine particles, it is produced by concentration, aggregation, drying, etc. (see, for example, JP-A-2012-92323).

As a method of adding this PTFE fine powder to a resin material or the like, for example, a method in which a PTFE dispersion is dispersed and mixed in water or an oily solvent, such as direct mixing, is known. It can be uniformly mixed by being added after being dispersed in water or an oily solvent.

However, the PTFE fine powder particles have a strong cohesive force, and in particular, in an oily solvent, the fine particle diameter, the low viscosity, and the storage stability are excellent, and there is a problem that dispersion is difficult.

On the other hand, in electronic materials, materials having a low specific dielectric ratio and a low dielectric tangent are required in recent years. Although an epoxy resin composition widely used as a substrate or a sealing material for an electronic device is used because of excellent adhesion or heat resistance, it has a problem that it is higher than a dielectric constant or a dielectric tangent.

Although the specific dielectric ratio of the epoxy resin material used as the substrate or sealing material of the electronic device differs depending on the composition, it is displayed in the range of 2.5 to 6.

Here, although PTFE is widely known as a resin material having a low specific dielectric constant and a low dielectric tangent, it has problems such as adhesion or poor compatibility with other resins, and thus it is less used as an electronic material. .

As a material having a low specific dielectric constant and a low dielectric tangent, PTFE (specific dielectric ratio 2.1) having the most excellent properties in a resin material has been attracting attention, but it is used by mixing and mixing PTFE or the like in various resin materials. It is limited (refer to, for example, Japanese Laid-Open Patent Publication No. 2001-49068).

Since the melt-mixing system is mixed in a state in which the resin is softened by heating, it is not suitable for mixing with a thermosetting resin material, a reactive resin material, or a resin material having a lower heat resistance than PTFE, and is not suitable as a mixture. A method of adding a specific dielectric constant or dielectric tangent of an epoxy resin material.

On the other hand, as a resin composition which does not impair the characteristics of the resin even if the PTFE filler is blended, and which has excellent low dielectric property, it is known to contain an epoxy resin represented by a specific formula as a hardener. A resin composition characterized by a phenol resin and a PTFE filler represented by a specific formula (see, for example, JP-A-2013-79326).

In the resin composition, the PTFE filler having an average particle diameter of 3 μm is dispersed by a bead mill together with an epoxy resin, a phenol resin or the like in the examples, and thus the present invention has not been obtained as a low ratio due to poor dispersibility. Dielectric composition, low dielectric tangent epoxy resin composition.

In such a situation, it is required to widely use an epoxy resin composition in which an PTFE is uniformly dispersed in an epoxy resin material such as an electronic material to have a low specific dielectric constant and a low dielectric tangent.

Further, although a method of using a fine powder of PTFE for uniformly dispersing PTFE is considered, a fine powder of PTFE is usually used in an emulsion polymerization method in water, a polymerization initiator, a fluorine-containing emulsifier, paraffin or the like. In the presence of a stabilizer, a tetrafluoroethylene (TFE) monomer is polymerized and obtained as an aqueous dispersion containing PTFE fine particles, and then concentrated, aggregated, dried, etc. (see, for example, JP-A-2012-92323). As a method of adding this PTFE fine powder to a resin material or the like, For example, a method in which a PTFE dispersion is dispersed and mixed in water or an oily solvent, other than the method of direct mixing, is known. It can be uniformly mixed by being added after being dispersed in water or an oily solvent.

However, the PTFE fine powder particles have a strong cohesive force, and in particular, in an oily solvent, the fine particle diameter, the low viscosity, and the storage stability are excellent, and there is a problem that dispersion is difficult.

In addition, when it is added to a water-insoluble resin or a photoresist material, and an oil-based solvent-based PTFE dispersion is required, many inventions relating to the aqueous dispersion of PTFE are known (see, for example, Japanese Laid-Open Patent Publication No. 2006-169448 In the case of the aqueous dispersion, there is almost no report on the PTFE dispersion of the oil-based solvent system (see, for example, JP-A-2011-509321).

The technique described in the same literature consists of PTFE particles with at least one mono- or polyolefin-based unsaturated oil or oil mixture, the molecules of the olefin-based unsaturated oil being on the surface of PTFE (primary) particles. Free radical reaction covalent bond/chemical bond, and the permanent charge separation between the surface of the PTFE particle and the bonded oil molecule, and the long-term stability of the PTFE particle in the oil or oil mixture - PTFE Dispersions. Further, the method described in the same literature is carried out by mixing a modified PTFE (latex) polymer having a continuous perfluoro(all oxygen) radical with at least one olefin-based unsaturated oil, and then The modified PTFE (latex) polymer is obtained by mechanical stress or the like, and the preparation method is complicated. The invention described in the same document is completely different from the technical idea (constitution and effect) of the present invention.

The present invention has been made in view of the above problems and the like, and provides an oil-based solvent dispersion of PTFE having excellent particle size, low viscosity, and excellent storage stability. Further, the present invention does not impair the epoxy resin. The state of excellent adhesion or heat resistance also provides a polytetrafluoroethylene (PTFE)-containing epoxy resin composition having a low specific dielectric ratio and a low dielectric tangent, and a cured product thereof.

As a result of careful examination of the above-mentioned problems, the inventors have found that PTFE of the above purpose can be obtained by a predetermined amount of PTFE containing a specific physical property and a fluorine-based additive having a specific functional group with respect to the mass of PTFE. The oily solvent dispersion is used to complete the present invention. The present inventors have found that a PTFE-containing epoxy resin composition having the above object and a cured product thereof can be obtained by containing at least an oil-based solvent dispersion of PTFE which is a specific physical property, an epoxy resin, and a curing agent.

That is, the present invention includes the following (1) to (4).

(1) An oil-based solvent dispersion of polytetrafluoroethylene, comprising a polytetrafluoroethylene and a fluorine-based additive, a polytetrafluoroethylene-based specific surface area of 15 m ² /g or less, and a fluorine-based additive based on polytetraethylene The quality of the vinyl fluoride has at least a fluorine-containing group and a lipophilic group of 0.1 to 50% by mass.

(2) A polytetrafluoroethylene-containing epoxy resin composition, It is characterized in that it contains at least an oil-soluble solvent dispersion of polytetrafluoroethylene, and an average particle diameter of the dispersion state of the dispersion system of the epoxy resin and the hardener or the polytetrafluoroethylene oil-based solvent is 1 μm or less.

(3) The polytetrafluoroethylene-containing epoxy resin composition according to (2), wherein the polytetrafluoroethylene oil-based solvent dispersion system having an average particle diameter of 1 μm or less in a dispersed state contains a primary particle diameter of 5 to 70% by mass. The polytetrafluoroethylene having a thickness of 1 μm or less and the fluorine-based additive having at least a fluorine-containing group and a lipophilic group in an amount of 0.1 to 40% by mass based on the mass of the polytetrafluoroethylene.

(4) A cured product of a polytetrafluoroethylene-containing epoxy resin, which is characterized in that the polytetrafluoroethylene-containing epoxy resin composition of (2) or (3) is cured.

According to the present invention, since the epoxy resin composition in which the PTFE fine particles are uniformly dispersed in the epoxy resin is cured, the adhesiveness and heat resistance of the epoxy resin are not impaired, and the low content can be efficiently obtained. An epoxy resin composition of PTFE which is superior in electrical properties to a dielectric constant and a low dielectric tangent, and a cured resin thereof.

[Formation of the Invention]

Hereinafter, embodiments of the present invention will be described in detail.

The PTFE oil-based solvent dispersion of the present invention is characterized by comprising PTFE having a specific surface area of 15 m ² /g or less, and fluorine having at least a fluorine-containing group and a lipophilic group in an amount of 0.1 to 50% by mass based on the mass of the PTFE. Additives.

Further, the PTFE-containing epoxy resin composition of the present invention is characterized in that it contains at least a PTFE oil-based solvent dispersion having an average particle diameter of 1 μm or less in a dispersed state, an epoxy resin, and a curing agent.

Further, the PTFE-containing epoxy resin cured product of the present invention is obtained by molding and hardening the PTFE-containing epoxy resin composition of the present invention.

[PTFE oily solvent dispersion]

The PTFE oil-based solvent-based dispersion system to be used in the present invention is not particularly limited as long as it is a PTFE-containing dispersion having an average particle diameter of 1 μm or less in a dispersed state in an oil-based solvent system, but is used, for example, at least by use. A PTFE having a primary particle diameter of 1 μm or less, a fluorine-based additive having at least a fluorine-containing group and a lipophilic group, and the like can be prepared.

Further, the PTFE oil-based solvent dispersion used in the present invention is preferably characterized in that it contains PTFE having a specific surface area of 15 m ² /g or less, and has at least fluorine content of 0.1 to 50% by mass based on the mass of the PTFE. A fluorine-based additive based on a lipophilic group.

PTFE may be used as such oily solvent-based dispersions of the present invention, the primary particle diameter of 1 μ m or less preferred. Further, the PTFE system used in the PTFE oil-based solvent dispersion of the present invention preferably has a specific surface area of 15 m ² /g or less.

Such a fine powder of PTFE is obtained by an emulsion polymerization method, for example The method described in the fluororesin manual (Kurokawa Hiroshi, Nikkan Kogyo Shimbun) can be obtained by a general method. In addition, the PTFE obtained by the emulsion polymerization is agglomerated and dried, and is used as a secondary particle in which the primary particle diameter has been aggregated or recovered as a fine powder. However, a method for producing various fine powders generally used can be used.

The PTFE based on the present invention has a specific surface area of 2 to 15 m ² /g. The "specific surface area" in the present invention (including the examples described later) is a value obtained by a gas adsorption method and using a BET formula.

When the specific surface area of the PTFE exceeds 15 m ² /g, it is difficult to precipitate due to aggregation in an oily solvent, and it is difficult to stably disperse, which is not preferable.

In addition, although the value of the specific surface area of the PTFE is as low as possible, it is preferably 2 m ² /g or more from the viewpoint of manufacturability and cost.

As the specific surface area PTFE which can be used specifically, Dyneon TF fine powder TF-9201Z, DyneonTF fine powder TF-9207Z (all manufactured by 3M Company), Nano FLON 119N, FLUORO E (any of them Shamrock Co., Ltd.) can be used. , TLP 10F-1 (manufactured by Mitsui & DuPont Fluorochemical Co., Ltd.), KTL-500F (manufactured by Kitamura Co., Ltd.), Algoflon L203F (manufactured by SOLVAY Co., Ltd.), and the like.

As the primary particle diameter of PTFE, the average particle diameter (50% by volume diameter, median diameter) of the volume basis measured by laser diffraction, scattering, dynamic light scattering, image imaging, etc. is 1 μm. The following setting is preferably carried out when it is stably dispersed in an oily solvent, and is preferably a dispersion of 0.5 μm or less, more preferably 0.3 μm or less.

When the primary particle diameter of the PTFE exceeds 1 μm , it tends to precipitate easily in an oily solvent, and it is difficult to stably disperse, which is not preferable. In addition, although the lower limit of the average particle diameter is as low as possible, it is preferably 0.05 μm or more from the viewpoint of manufacturability and cost.

Further, although the primary particle diameter of the PTFE of the present invention means a value obtained by a laser diffraction, a scattering method, a dynamic light scattering method, or the like in the polymerization step of the fine powder, the fine powder in a powder state is obtained by drying. When the primary particles are strongly cohesive with each other, it is difficult to easily measure the primary particle diameter by laser diffraction, scattering, dynamic light scattering, or the like, and thus may also mean a value obtained by image imaging. Examples of the measurement device include a dynamic light scattering method by FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.) or a laser diffraction scatter method using Microtrac (manufactured by Nikkiso Co., Ltd.) or by Mac-View. Image imaging method (made by Mountech Co., Ltd.).

In the present invention, it is preferable to contain 5 to 70% by mass of PTFE, more preferably 10 to 60% by mass, based on the total amount of the oil-based solvent dispersion.

When the content is less than 5% by mass, the amount of the oily solvent is large, and the PTFE fine particles are easily precipitated due to the extreme decrease in viscosity, and the defects are caused by the large amount of the oily solvent when mixed with a material such as an epoxy resin, for example, when the solvent is removed. It takes time and other bad conditions. On the other hand, when the mass exceeds 70 mass%, the PTFE easily aggregates with each other, and it is extremely difficult to maintain the state of the fine particles in a stable fluidity state, which is not preferable.

The fluorine-based additive which can be used in the oil-based solvent-based dispersion of the present invention is not particularly limited as long as it has at least a fluorine-containing group and a lipophilic group, and may further contain a hydrophilic group.

By using at least a fluorine-based additive having a fluorine-containing group and a lipophilic group, the surface tension of the oily solvent of the dispersion medium is lowered, the wettability of the PTFE surface is improved, and the dispersibility of the PTFE is improved, and the surface of the PTFE is sucked. The fluorine-containing group and the oil-soluble solvent in the dispersion medium are elongated, and the steric hindrance of the lipophilic group prevents the aggregation of the PTFE to further improve the dispersion stability.

Examples of the fluorine-containing group include a perfluoroalkyl group and a perfluoroalkenyl group. Examples of the lipophilic group include one or two or more selected from the group consisting of an alkyl group, a phenyl group, and a decyloxy group. Examples of the hydrophilic group include, for example, a hydrophilic group. One or two or more kinds of ethylene oxide or an amine group, a ketone group, a carboxyl group, and a sulfonic acid group.

Specifically, it can be used in the Surflon series (made by AGC Seimei Chemical Co., Ltd.) such as Surflon S-611 containing a perfluoroalkyl group, the Megafac series (made by DIC Corporation) such as Megafac F-555, Megafac F-558, and Megafac F-563, and UNIDYNEDS-403N. UNIDYNE series (made by Daikin Industries Co., Ltd.) can be used.

The type of the PTFE and the oily solvent to be used in the fluorine-based additive may be selected from the following types, and may be used in one type or in combination of two or more types.

The content of the fluorine-based additive is 0.1 to 50% by mass based on the mass of the PTFE, but is preferably 5 to 30% by mass, more preferably 15 to 25% by mass.

When the content is less than 0.1% by mass, the oily solvent does not sufficiently wet the surface of the fine powder of PTFE. On the other hand, when it exceeds 50% by mass, the foaming property of the dispersion becomes strong and the efficiency of dispersion is lowered. It is not preferable because the operability of the dispersion itself or the subsequent occurrence of defects when mixed with a resin material or the like.

The oily solvent dispersion of PTFE of the present invention may be combined with the fluorine-based additive as described above without damaging the effects of the present invention, and other surfactants may be used.

For example, a surfactant such as a nonionic surfactant, an anionic surfactant, or a cationic surfactant, or a polymer surfactant such as a nonionic surfactant, an anionic surfactant, or a cationic surfactant may be used, but it is not limited thereto and can be used.

The above oily dispersion oily solvent used in the present invention is selected, for example, from γ-butyrolactone, acetone, methyl ethyl ketone, hexane, heptane, octane, 2-heptane, cyclopentanone, cyclohexane Ketone, cyclohexane, methylcyclohexane, ethylcyclohexane, methyl-n-amyl ketone, methyl isobutyl ketone, methyl isoamyl ketone, ethylene glycol, diethylene glycol, Propylene glycol, dipropylene glycol, ethylene glycol monoacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monoacetate, diethylene glycol diethyl Ethyl ether, propylene glycol monoacetate, dipropylene glycol monoacetate, propylene glycol diacetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, cyclohexylacetic acid Ester, ethyl 3-ethoxypropionate, dioxane, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methoxypropyl Methyl ester, ethyl ethoxy propionate, anisole, ethyl benzyl ether, tolyl methyl ether, diphenyl ether, dibenzyl ether, phenyl Ether, butylphenyl ether, benzene, ethylbenzene, diethylbenzene, pentylbenzene, cumene, toluene, xylene, methyl cumene, mesitylene, methanol, ethanol, isopropanol, Butanol, methyl monoglycidyl ether, ethyl monoglycidyl ether, butyl monoglycidyl ether, phenyl monoglycidyl ether, methyl diglycidyl ether, ethyl diglycidyl ether, butyl diglycidyl Ether, phenyl diglycidyl ether, methyl phenol monoglycidyl ether, ethyl phenol monoglycidyl ether, butyl phenol monoglycidyl ether, mineral oil, 2-hydroxyethyl acrylate, tetrahydrofurfuryl acrylate, 4 -vinylpyridine, N-methylpyrrolidone, 2-ethylhexyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, glycidyl methacrylate, neopentyl glycol diacrylate, A solvent of one type consisting of hexanediol diacrylate, trimethylolpropane triacrylate, methacrylate, methyl methacrylate, and styrene, or two or more of these solvents.

Examples of such oily solvents include methyl ethyl ketone, cyclohexanone, butyl glycidyl ether, propylene glycol monomethyl ether acetate, N-methylpyrrolidone, γ-butyrolactone, and isopropanol. Preferably, it is more preferably used depending on the use of the epoxy resin composition, etc., and examples thereof include methyl ethyl ketone, cyclohexanone, and butyl glycidyl ether.

Although the above oily solvent is used in the present invention, it may be used in combination with other oily solvents or other oily solvents may be used depending on the intended use (various resin materials or rubbers, adhesives, lubricants or lubricating oils, printing inks or coatings). Suitable.

Furthermore, although the polarity of the oily solvent used is considered to be high in compatibility with water, the amount of water is too large to hinder the oily solvent of PTFE. Dispersion, which causes the viscosity to rise or the particles to condense with each other. The oily solvent used in the present invention is preferably a water content of 20,000 ppm or less by the Karl Fischer method (0 ≦ water content ≦ 20000 ppm). The measurement of the moisture content by the Karl Fischer method in the present invention (including the examples described later) is measured in accordance with JIS K 0068:2001, and can be measured using MCU-610 (manufactured by Kyoto Electronics Manufacturing Co., Ltd.). By setting the water content in the oil solvent to 20,000 ppm or less, it is possible to further obtain a dispersion of an oily solvent system of PTFE having a fine particle diameter, a low viscosity, and excellent storage stability. Further, although the above-described adjustment of the amount of water or less may be carried out, a dehydration method of an oily solvent generally used may be used, but for example, a molecular sieve or the like can be used.

The content of the oily solvent used in the above oily dispersion of the present invention is the remaining amount of the above PTFE or fluorine-based additive.

The above oily dispersion system of the present invention may further contain a polyoxyalkylene-based antifoaming agent or a fluorine-based antifoaming agent. In particular, when 70% by mass of PTFE is used in a high concentration of 50% by mass of the fluorine-based additive of the mass of PTFE, the foaming property of the dispersion is related to the mixing step of the dispersion, the stability, the resin material, and the like. The situation that caused the problem.

As the defoaming agent which can be used, there are polyoxyalkylene-based or fluorine-based latex type, self-emulsified type, oil type, oil composite type, solution type, powder type, solid type, etc., but it is used together with the oily solvent to be used. Combine and choose the right one. In particular, at the interface between the oily solvent and the PTFE, in order to have an interface between the oil solvent and the air, for example, a hydrophilic or water-soluble polyoxyalkylene-based defoaming agent is preferably used, and it is not limited thereto. Although the content of the defoamer is variable depending on the content (concentration) of PTFE, etc., it is relative to dispersion. The total amount of the body is preferably 1% by mass or less as an active ingredient.

In the dispersion state of the above oily solvent-based dispersion system of the present invention, the average particle diameter of the laser diffraction by PTFE scattering/scattering method or dynamic light scattering method is 1 μm or less.

When PTFE having a primary particle diameter of 1 μm or less is used, the primary particles are usually aggregated, and the secondary particles have a fine particle size of 1 μm or more. By dispersing the secondary particles of PTFE so as to have a particle diameter of 1 μm or less, dispersion is carried out, for example, by using a disperser such as an ultrasonic disperser, a three-roller, a ball mill, a bead mill, or a jet mill. A stable dispersion can also be obtained at low viscosity and long-term storage.

Further, in the present invention, the water content of the PTFE oil-based solvent dispersion measured by the Karl Fischer method is preferably 20,000 ppm or less (0 ≦ water content ≦ 20000 ppm). Although the degreasing solvent contains water, it is also possible to consider the moisture contained in the material such as the fine powder of PTFE or the fluorine-based additive or the water mixed in the manufacturing step of dispersing the PTFE in the oily solvent, by using the oily solvent of the last PTFE. When the water content of the dispersion is 20,000 ppm or less, a PTFE oil-based solvent dispersion which is more excellent in storage stability can be obtained. Further, although the dehydration method of the oil solvent generally used can be used as the adjustment below the water content, for example, a molecular sieve or the like can be used. Further, PTFE can be used in a state where the amount of water is sufficiently lowered by dehydration such as heating or decompression. In addition, after the PTFE oil-based solvent dispersion is produced, the water content can be removed by a molecular sieve or a membrane separation method. However, the water content of the oil-based solvent-based dispersion can be reduced, and it is not particularly limited.

The content of the PTFE oil-based solvent dispersion having an average particle diameter of 1 μm or less in the above dispersed state of the present invention depends on the amount of the PTFE or the oily solvent contained in the dispersion, and the epoxy resin composition. The use of the oil-based solvent in the epoxy resin composition is the final epoxy resin composition, and is removed during curing, so that it is preferably 1 part by mass based on 100 parts by mass of the epoxy resin. ~100 parts by mass, more preferably 1 to 25 parts by mass, adjusted to use a dispersion.

When the content of the PTFE is 1 part by mass or more based on 100 parts by mass of the epoxy resin, electrical properties of a low specific dielectric constant and a low dielectric tangent can be exhibited, and the content is set to 100 parts by mass or less. The effect of the present invention can be exerted without impairing the adhesion or heat resistance of the epoxy resin.

In addition, since the oil-based solvent dispersion contains PTFE having an average particle diameter of 1 μm or less in a dispersed state, it is excellent in fine particle diameter, low viscosity, and storage stability, and is excellent in re-dispersibility even after long-term storage. Moreover, even if it contains a large amount of fluorine-based additives, it is excellent in defoaming property, and can be uniformly dispersed when it is added to an epoxy resin composition.

The oily solvent dispersion system of the present invention is used in an amount of 0.1 to 50% by mass of the PTFE having a specific surface area of 15 m ² /g or less and a fluorine-based additive having at least a fluorine-containing group and a lipophilic group. The dispersion is carried out by using a dispersing machine such as an ultrasonic disperser, a three-roller, a ball mill, a bead mill, or a jet mill, and the average particle diameter (secondary particle) of the PTFE by the dynamic light scattering method in the dispersed state is 1. A fine particle size of not more than μ m and a stable dispersion can be obtained even when stored at a low viscosity (20 mPa·s or less) for a long period of time.

Further, in the present invention, the water content of the PTFE oil-based solvent dispersion of the Karl Fischer method is preferably 20,000 ppm or less (0 ≦ water content ≦ 20000 ppm). In addition to the moisture content of the degreasing solvent, it is also possible to consider the moisture contained in the material such as the fine powder of PTFE or the fluorine-based additive or the moisture mixed in the manufacturing step of dispersing the PTFE in the oily solvent, but finally borrowing When the moisture content of the oil-based solvent dispersion of PTFE is 20,000 ppm or less, a PTFE oil-based solvent dispersion which is more excellent in storage stability can be obtained. Further, although the dehydration method of the oil solvent generally used can be used as the adjustment below the water content, for example, a molecular sieve or the like can be used. Further, PTFE can be used in a state where the amount of water is sufficiently lowered by dehydration such as heating or decompression. In addition, after the PTFE oil-based solvent dispersion is produced, the water content can be removed by a molecular sieve or a membrane separation method. However, the water content of the oil-based solvent-based dispersion can be reduced, and it is not particularly limited.

The oleic solvent dispersion system of the present invention having the above-described constitution of PTFE is used by using PTFE having a specific surface area of 15 m ² /g or less and a fluorine-based additive having at least a fluorine-containing group and a lipophilic group. ~50% by mass, excellent in micro-grain, low-viscosity, and storage stability, and excellent in dispersibility after long-term storage. In addition, even if a large amount of the fluorine-based additive is contained, it is excellent in defoaming property, and can be uniformly dispersed when added to various resin materials, rubbers, adhesives, lubricants, lubricating oils, printing inks, paints, and the like.

[epoxy resin]

As the epoxy resin used in the present invention, an epoxy resin containing an average of one or more epoxy groups (oxyethylene rings) may be used, and examples thereof include a bisphenol F type epoxy resin and a bisphenol A type epoxy resin. Phenolic varnish type epoxy resin, cresol novolac type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, dicyclopentadiene type epoxy resin, aralkyl type epoxy resin, biphenyl aryl At least one of an alkyl epoxy resin and a hydrogenated epoxy resin or an alicyclic epoxy resin obtained by hydrogenating a phenyl group of the above various epoxy resins.

The epoxy resin which can be used in the present invention is not limited to the above-mentioned resin as long as it has one or more epoxy groups in one molecule, but bisphenol A, hydrogenated bisphenol A, cresol novolac, and the like are suitable.

〔hardener〕

The above-mentioned hardener for epoxy resin used in the present invention may, for example, be ethylenediamine, triethylenepentamine, hexamethylenediamine, dimer acid-modified ethylenediamine or N-ethylaminopiperazine. Aliphatic amines such as isophorone diamine, m-phenylenediamine, p-phenylenediamine, 3,3'-diaminodiphenyl hydrazine, 4,4'-diaminophenol quinone, 4,4 Aromatic amines such as '-diaminophenol methane and 4,4'-diaminophenol ether, mercaptopropionates, thiol groups such as terminal sulfhydryl compounds of epoxy resins, bisphenol A, bisphenol F, and double Phenol AD, bisphenol S, tetramethyl bisphenol A, tetramethyl bisphenol F, tetramethyl bisphenol AD, tetramethyl bisphenol S, tetrabromobisphenol A, tetrachlorobisphenol A, tetrafluoroethylene Phenol A, bisphenol, dihydroxynaphthalene, 1,1,1-tris(4-hydroxyphenyl)methane, 4,4-(1-(4-(1-(4-hydroxyphenyl))-1-methyl) Benzo)ethylidene)bisphenol, novolac, cresol novolac, bisphenol A novolac, brominated phenol novolac, scented bisphenol A novolac, etc. Phenolic resins, aromatic cyclic hydrogenated polyols of such phenol resins, polyphthalic anhydride, methyltetrahydrophthalic anhydride, tetrahydrophthalic acid, methylhexahydrophthalic anhydride, hexahydrogen Phthalic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, norbornane-2,3-dicarboxylic anhydride, methyl-5-norbornene-2,3-dicarboxylic anhydride , an alicyclic acid anhydride such as methyl-5-norbornane-2,3-dicarboxylic anhydride, an aromatic anhydride such as phthalic anhydride, trimellitic anhydride or pyromellitic anhydride, 2-methylimidazole And imidazoles such as 2-ethyl-4-methylimidazole and 2-phenylimidazole, and salts thereof, reacted by the above aliphatic amines, aromatic amines, and/or imidazoles and epoxy resins The obtained amine adducts, anthraquinones such as diammonium adipate, dimethylbenzylamine, 1,8-diazabicyclo[5.4.0]undecene-7 and the like At least one of an organic phosphine such as triphenylphosphine and dicyanodiamine.

Among these, alicyclic acid anhydrides and aromatic acid anhydrides are preferred, and more preferred are aliphatic cyclic acid anhydrides, particularly preferably methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, norbornane-2,3-di. Carboxylic anhydride, methylnorbornene-2,3-dicarboxylic anhydride.

The amount of the curing agent used is preferably from 1 to 200 parts by mass, more preferably from 2 to 100 parts by mass, per 100 parts by mass of the epoxy resin.

The amount of use is sufficient to carry out a crosslinking reaction in the range of 1 to 200 parts by mass, and an epoxy resin cured product having excellent light resistance, heat resistance, mechanical strength, or dimensional stability can be obtained.

[PTFE-containing epoxy resin composition]

The PTFE-containing epoxy resin composition of the present invention may be blended with a hardening accelerator, an antifoaming agent, a coloring agent, and a fluorescent light in addition to the above components. A suitable amount of a conventionally known additive such as a body, a modifier, an anti-tarnishing agent, an inorganic filler, a decane coupling agent, a light diffusing agent, or a thermally conductive filler.

For use as a hardening (reaction) promoter, for example, imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole, 1,8-diazabicyclo[5.4.0]undecene-7 Others such as tertiary amines and their salts, guanidines such as triphenylphosphine, sulfonium salts such as triphenylphosphonium bromide, amine triazoles, tin octylate, dibutyltin dilaurate, etc. A zinc catalyst such as zinc, a metal catalyst such as aluminum acetonide such as aluminum, chromium, cobalt or zirconium. These hardening (reaction) accelerators may be used singly or in combination of two or more.

The PTFE-containing epoxy resin composition of the present invention can be obtained by molding and hardening in the same manner as the known epoxy resin composition. The molding method and the curing method can be carried out in the same manner as the known epoxy resin composition, and the method inherent to the PTFE-containing epoxy resin composition of the present invention is not required, and is not particularly limited.

The cured PTFE-containing epoxy resin of the present invention may be in the form of a laminate, a molded article, a laminate, a coating film, a film, or the like.

The PTFE-containing epoxy resin composition of the present invention and the cured product thereof are excellent in electrical properties of the low dielectric constant and low dielectric tangent without impairing the adhesion or heat resistance of the epoxy resin. Suitable electronic substrate materials, insulating materials, bonding materials, and the like are known, for example, as materials for sealing materials for electronic components, copper clad laminates, insulating coatings, composite materials, and insulating adhesives.

Example

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples. However, the present invention is not limited to the following examples and the like.

[Preparation of PTFE oily solvent dispersion: dispersion 1~5]

In the oily solvent, the fluorine-based additive was sufficiently stirred and blended as shown in the following Table 1, and then PTFE was further added and stirred and mixed. Then, the obtained PTFE mixed liquid was dispersed in a 0.3 mm diameter zirconium bead using a transverse bead mill to obtain each dispersion 1 to 5.

The average particle diameter of the obtained PTFE of the dispersions 1 to 5 was measured by a laser diffraction ‧ scattering method of Microtrac (manufactured by Nikkiso Co., Ltd.). Further, it was confirmed that the water content of each of the dispersions 1 to 5 measured by the Karl Fischer method was 20,000 ppm or less.

The blending ratio of the dispersions 1 to 5 shown in the following Table 1 in Table 1 below, the average particle diameter of the PTFE of the obtained dispersion.

[Examples 1 to 5 and Comparative Examples 1 to 3: Preparation of a PTFE-containing epoxy resin composition and a cured product thereof]

Using the obtained dispersions 1 to 5, a cured product was prepared using the PTFE-containing epoxy resin composition at the blending ratio shown in Table 2 below.

After sufficiently mixing in the blending ratios shown in Examples 1 to 5 and Comparative Examples 1 to 3, the solvent was removed under reduced pressure at 50 ° C, and the temperature was further lowered while reducing the pressure to 100 ° C. Then, the pressure was released, and the temperature was raised to 180 ° C to obtain a cured product.

The dielectric properties (specific dielectric ratio, dielectric tangent) of the obtained cured products were measured for dielectric specificity and dielectric tangent at 23 ° C and 1 GHz using a Material Analyzer 4291B (manufactured by Agilent Technologies, Inc.).

These results are shown in Table 2 below.

As is apparent from the above Table 2, Examples 1 to 5 within the scope of the present invention lower any specific dielectric constant and dielectric tangent than Comparative Example 1 in which PTFE was not added. On the other hand, Comparative Examples 2 and 3 outside the scope of the present invention and the comparative examples which were not added had almost no change in dielectric ratio, and the dielectric tangent was also a result of almost no change with no addition.

Next, an example of the PTFE oil-based solvent dispersion used in the present invention will be described in detail with reference to examples and comparative examples.

[Examples 11 to 17 and Comparative Example 11]

Eight kinds of PTFE (A to H) of each specific surface area were used as the fluorine-based additive, and a fluorine-containing ‧ lipophilic group-containing oligomer was used as the oil-based solvent. Ethyl ketone modulates an oily solvent dispersion of PTFE. Further, although G and H of the PTFE powder are the same, G is a PTFE powder having a specific surface area adjusted by heating the PTFE powder at a temperature of 270 ° C to change the surface state.

Moreover, in the above preparation, the fluorine-based additive is sufficiently stirred and mixed in the oily solvent, and then PTFE is added, and further stirred and mixed.

The mixed solution of PTFE obtained as described above was dispersed in a 0.3 mm diameter zirconium bead using a transverse bead mill to obtain an oily solvent dispersion of each of PTFE of Examples 11 to 17 and Comparative Example 11. Further, the water content of each of the oil-based solvent dispersions of Examples 11 to 17 and Comparative Example 11 measured by the Karl Fischer method was confirmed to be 20,000 ppm or less.

As each of the obtained oily solutions of Examples 11 to 17 and Comparative Example 11, Evaluation of the dispersion of the agent system, measurement of the average particle diameter and viscosity, specifically, the average particle diameter (nm) of PTFE of each dispersion was measured by FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.), and by the E-type viscometer Each viscosity (mPa‧s, 25 °C) was measured. These results are shown in Table 4 below.

As is apparent from the above Tables 3 and 4, although Examples 11 to 17 were dispersible, Comparative Example 1 outside the scope of the present invention was gelled, and a good dispersion could not be obtained. Further, in Example 17, which had a specific surface area of approximately 15 m ² /g, it was dispersible, but it was an oil-based solvent dispersion having a slightly high viscosity. Further, any of the oily solvent dispersions is excellent in stability.

[Industry Utilization]

The PTFE-containing epoxy resin composition of the present invention and the cured product thereof are a substrate, a sealing material, an insulating material, and the like which are used for an epoxy resin material or the like used in an electronic device.

Claims (4)

An oil solvent dispersion of polytetrafluoroethylene characterized by comprising polytetrafluoroethylene and a fluorine-based additive, wherein the polytetrafluoroethylene has a specific surface area of 15 m ² /g or less, and the fluorine-based additive is relative to polytetrafluoroethylene The mass of ethylene has at least a fluorine-containing group and a lipophilic group of 0.1 to 50% by mass. A polytetrafluoroethylene-containing epoxy resin composition characterized by comprising at least a polytetrafluoroethylene oil-based solvent dispersion, an epoxy resin, and a hardener, and the polytetrafluoroethylene oil solvent dispersion system is dispersed. The average particle size is 1 μm or less. The polytetrafluoroethylene-containing epoxy resin composition according to the second aspect of the patent application, wherein the polytetrafluoroethylene oil solvent dispersion system having an average particle diameter of 1 μm or less in a dispersed state contains 5 to 70% by mass. The polytetrafluoroethylene having a particle diameter of 1 μm or less and the fluorine-based additive having at least a fluorine-containing group and a lipophilic group in an amount of 0.1 to 40% by mass based on the mass of the polytetrafluoroethylene. A polytetrafluoroethylene-containing epoxy resin cured product characterized by curing a polytetrafluoroethylene-containing epoxy resin composition according to claim 2 or 3.