WO2015152240A1 - Polytetrafluoroethylene dispersion in oily solvent - Google Patents

Abstract

Provided is a polytetrafluoroethylene (PTFE) dispersion in an oily solvent, the dispersion having a small particle diameter, a low viscosity, and excellent storage stability and being suitable for, for example, addition to resist materials and addition to epoxy resin materials. An embodiment of this PTFE dispersion in an oily solvent is an oily-solvent-based dispersion which contains 5-70 mass% polytetrafluoroethylene micropowder having a primary-particle diameter of 1 µm or smaller and further contains a fluorochemical additive containing at least a fluorine-containing group and an oleophilic group, in an amount of 0.1-40 mass% with respect to the mass of the polytetrafluoroethylene micropowder and which has an overall water content, as measured by the Karl Fischer method, of 20,000 ppm or less.

Description

Oil-based solvent dispersion of polytetrafluoroethylene

The present invention relates to an oily solvent-based dispersion of polytetrafluoroethylene suitable for addition of a resist material or an epoxy resin material having a fine particle size, a low viscosity, and excellent storage stability.

In recent years, electronic devices have become faster and more advanced, and higher communication speeds have been demanded. Under these circumstances, low dielectric constants and low dielectric loss tangents are required for various electronic equipment materials. Resist materials such as black matrix materials for liquid crystal displays, insulating materials and substrate materials have low dielectric constants and low dielectric constants. Tangentization is also required.

As a material having a low dielectric constant and a low dielectric loss tangent, polytetrafluoroethylene (PTFE) having the most excellent characteristics among resin materials is attracting attention. PTFE micropowder is mixed in various resin materials. Therefore, the dielectric constant and the dielectric loss tangent of the material can be reduced.

Polytetrafluoroethylene (PTFE) is a material excellent in heat resistance, electrical insulation, low friction characteristics, non-adhesiveness, weather resistance, etc. in addition to the above-mentioned low dielectric constant and low dielectric loss tangent. It is used for electronic devices including insulating materials and substrate materials, sliding materials, automobiles, kitchen utensils and the like. Polytetrafluoroethylene having such properties is used as a micropowder for the purpose of improving product properties by being added to the various resin materials, rubbers, adhesives, lubricants, greases, printing inks, paints, etc. ing.

Such polytetrafluoroethylene micropowder is usually obtained by polymerizing tetrafluoroethylene (TFE) monomer in the presence of a stabilizer such as water, a polymerization initiator, a fluorine-containing emulsifier, and paraffin wax by an emulsion polymerization method. After being obtained as an aqueous dispersion containing polytetrafluoroethylene fine particles, it is produced through concentration, aggregation, drying, and the like (see, for example, Patent Document 1).

As a method for adding the polytetrafluoroethylene micropowder to a resin material, for example, in addition to a method of directly mixing, a method of dispersing in water or an oily solvent and mixing as a PTFE dispersion is known. Yes. By adding after dispersing in water or an oily solvent, it can be mixed uniformly.
However, polytetrafluoroethylene micropowder has a strong cohesive force between particles, and in particular, there is a problem that it is difficult to disperse in an oily solvent in a form having a fine particle size, a low viscosity, and excellent storage stability.

Furthermore, when adding to a water-insoluble resin or resist material, an oil-based solvent-based polytetrafluoroethylene dispersion is required, and many inventions relating to an aqueous dispersion of polytetrafluoroethylene are known. (See, for example, Patent Documents 2 and 3), however, there are almost no reports on oil-based solvent-based polytetrafluoroethylene dispersions compared to this aqueous dispersion (see, for example, Patent Documents 4 and 5). ).
The technique described in Patent Document 4 comprises PTFE particles and at least one mono- or polyolefin-based unsaturated oil or oil mixture, and the molecules of the olefin-based unsaturated oil are radicals on the surface of PTFE (primary) particles. There is permanent charge separation between the oil molecules that are covalently / chemically bound by the reaction and then bound to the PTFE particle surface and fine dispersion of the PTFE particles in the oil or oil mixture. A long-term stable oil-PTFE dispersion, the process of which is modified PTFE (emulsion) polymer with persistent perfluoro (peroxy) radicals mixed with at least one olefinically unsaturated oil, And the modified PTFE (emulsion) polymer is obtained by a method in which it is subjected to mechanical stress, etc. A miscellaneous, also not those using PTFE particles generic, the present invention, the technical idea (structures and effects thereof) is one which differs at all.

In addition, the technique described in Patent Document 5 describes that “a non-aqueous medium such as a fluoropolymer such as PTFE, an organic solvent having a boiling point of 40 to 250 ° C., and a dispersion stabilizer having a general formula: Rf1- (X) nY [wherein Rf1 is a partially fluorinated alkyl group or a fully fluorinated alkyl group having 1 to 12 carbon atoms, n is 0 or 1, and X is —O—, —COO— or —OCO—, Y is — (CH ₂ ) pH, — (CH ₂ ) pOH or — (OR1) q (OR2) rOH, p is an integer from 1 to 12, and q is from 1 to 12 R is an integer of 0 to 12, and R1 and R2 are alkylene groups having 2 to 4 carbon atoms, provided that R1 and R2 are different from each other. At least one selected, and the water content is 1% or more The fluoropolymer nonaqueous dispersion. "And the like is described, characterized in that it.

However, Patent Document 5 does not have any description or suggestion regarding “polytetrafluoroethylene micropowder having a primary particle diameter of 1 μm or less”. According to paragraph [0041] of Patent Document 5, “when a powdered fluoropolymer is dispersed, a dispersion liquid that hardly reaggregates can be obtained by dispersing in a size of 5 to 500 μm”. In the support of Experimental Examples 1 to 12 as examples, “Lublon L-2 (PTFE)” manufactured by Daikin Industries, Ltd. as a fluoropolymer (in the technical data, the average particle size (50 %) 3.5 μm). In addition, “when the aqueous dispersion is phase-converted, the size is 0.05 to 5 μm”. Thus, in Patent Document 5, it is not assumed that particles of 1 μm or less are used when polytetrafluoroethylene micropowder powder is used, or that it is difficult when powder is dispersed in the dark. Show.
Further, regarding the moisture content, in paragraph [0048] of Patent Document 5, the moisture content is 0.1% or less, preferably 0.1% or more preferably 0.01% or less, paragraph [0049]. Describes that it is important to control the amount of moisture when used in combination with components that dislike moisture, such as electrode active materials. On the other hand, the present invention manages the amount of water not for mixing but for the stability of the dispersion after preparation of the dispersion, and refers to the mixing in Patent Document 5. In addition, Document 5 does not demonstrate the effect of the amount of water in the examples.
Therefore, although the said patent document 5 discloses the proximity | contact technique of this invention, the said technical document (a structure and its effect) differs from the said patent document 5 and this invention.

Furthermore, conventionally, as a method of mixing a powder material such as PTFE micropowder into a resist material, for example, as a method for adjusting a resist material for a black matrix, a colored paste mainly containing a pigment was prepared. Thereafter, a method of mixing with a photosensitive resin composition is known (see, for example, Patent Documents 6 and 7). In the same manner as these methods, after PTFE micropowder is dispersed in an oil-based solvent system, a resist is used. Attempts have been made to mix the materials.

However, the PTFE micropowder as in Patent Documents 6 and 7 has a strong cohesion between particles, and it is difficult to uniformly disperse and mix in a resin material such as a resist material with a fine particle size. There is.
In particular, the resist material is a material that forms a fine pattern by exposure and development. If the particle size of PTFE is large or is not uniformly dispersed, a problem may occur during pattern formation. Therefore, a PTFE dispersion having high dispersibility is required.

Furthermore, there is an epoxy resin material as one of the materials widely used as a substrate or a sealing material for electronic equipment. The relative dielectric constant of the epoxy resin material varies depending on its composition, but is about 2.5-6. It is shown.
On the other hand, as a material having a low relative dielectric constant and a low dielectric loss tangent, polytetrafluoroethylene (PTFE, relative dielectric constant 2.1) having the most excellent characteristics among resin materials is noted as described above. However, it is used by melting and mixing PTFE in various resin materials. (For example, see Patent Document 8)

In the melt mixing as in the above-mentioned Patent Document 8, since the resin is mixed while being heated and softened, it is mixed with a thermosetting resin material, a reactive resin material, a resin material having lower heat resistance than PTFE, or the like. In this case, it is not suitable, and it is not suitable as a method of adding to lower the dielectric constant and dielectric loss tangent of the epoxy resin material.
Under such circumstances, there is a demand for a method and material for mixing PTFE uniformly and at a high concentration in an epoxy resin material widely used for electronic materials.

JP 2012-92323 A JP 2006-169448 A JP 2009-179802 A Special table 2011-509321 gazette JP 2011-225710 A JP-A-6-289216 JP 2008-242377 A JP 2001-49068 A

The present invention intends to solve the above-mentioned conventional problems and the present situation, and is a polycrystal suitable for resist material addition, epoxy resin addition, etc., having a fine particle size, low viscosity and excellent storage stability. An object is to provide an oil-based solvent dispersion of tetrafluoroethylene.

As a result of intensive studies on the above-mentioned conventional problems and the like, the present inventors have found that an oil-based solvent-based dispersion of polytetrafluoroethylene of the above object can be obtained by the following first to sixth inventions. It has been completed.

That is, according to the first invention, polytetrafluoroethylene micropowder having a primary particle size of 1 μm or less is 5 to 70% by mass, and a fluorine-based additive containing at least a fluorine-containing group and a lipophilic group is added to the mass of polytetrafluoroethylene. An oil-based solvent dispersion of polytetrafluoroethylene containing 0.1 to 40% by mass based on the Karl Fischer method and having a total water content of 20000 ppm or less.

In the second invention, the oil-based solvent dispersion of polytetrafluoroethylene according to the first invention is characterized in that the water content of the oil-based solvent used in the oil-based solvent-based dispersion is 20000 ppm or less. Is the body.

In the third invention, the oily solvent used in the oily solvent dispersion is γ-butyrolactone, acetone, methyl ethyl ketone, hexane, heptane, octane, 2-heptanone, cycloheptanone, cyclohexanone, cyclohexane, methylcyclohexane, ethylcyclohexane, Methyl-n-pentyl ketone, methyl isobutyl ketone, methyl isopentyl 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 ether, propylene glycol monoacetate, dipropylene Recall monoacetate, propylene glycol diacetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, cyclohexyl acetate, ethyl 3-ethoxypropionate, dioxane, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate , Butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetol, butyl phenyl ether, benzene, ethylbenzene, diethylbenzene , Pentylbenzene, isopropylbenzene, toluene, xylene, shime , 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 Ether, methylphenol monoglycidyl ether, ethylphenol monoglycidyl ether, butylphenol monoglycidyl ether, mineral spirit, 2-hydroxyethyl acrylate, tetrahydrofurfuryl acrylate, 4-vinylpyridine, N-methylpyrrolidone, 2-ethylhexyl acrylate, 2- Hydroxyethyl methacrylate, hydroxypropyl methacrylate, glycy One solvent selected from the group consisting of dimethyl methacrylate, neopentyl glycol diacrylate, hexanediol diacrylate, trimethylolpropane triacrylate, methacrylate, methyl methacrylate, styrene, or two or more of these solvents This is an oily solvent-based dispersion of polytetrafluoroethylene according to the first invention or the second invention.

The fourth invention is characterized in that the average particle diameter of the polytetrafluoroethylene micropowder in the oil-based solvent dispersion by laser diffraction / scattering method or dynamic light scattering method is 1 μm or less. It is an oily solvent-based dispersion of polytetrafluoroethylene according to the third invention.

The fifth invention is the oil-based solvent dispersion of polytetrafluoroethylene according to the first to fourth inventions, further comprising a silicone-based antifoaming agent.

The sixth invention is characterized in that the oil-based solvent dispersion of polytetrafluoroethylene according to any one of the first to fifth inventions is for adding a resist material or an epoxy resin material. To do.

The oil-based solvent dispersion of polytetrafluoroethylene of the present invention has a fine particle size, low viscosity, excellent storage stability, and excellent redispersibility even after long-term storage, especially for resist material addition and epoxy resin addition It can use suitably for. Also, even if it contains a lot of fluorine-based additives, it has excellent antifoaming properties. When added to various resin materials such as resist materials and epoxy resins, rubber, adhesives, lubricants and greases, printing inks and paints, etc. Can be mixed evenly.

Hereinafter, embodiments of the present invention will be described in detail.
The oil-based solvent dispersion of polytetrafluoroethylene according to the present invention comprises 5 to 70% by mass of a polytetrafluoroethylene micropowder having a primary particle size of 1 μm or less, and a fluorine-based additive containing at least a fluorine-containing group and a lipophilic group. Is contained in an amount of 0.1 to 40% by mass with respect to the mass of the polytetrafluoroethylene micropowder.

The polytetrafluoroethylene micropowder used in the present invention has a primary particle size of 1 μm or less.
Such polytetrafluoroethylene micropowder is obtained by an emulsion polymerization method, and is generally used, for example, a method described in a fluorine resin handbook (edited by Takaomi Kurokawa, Nikkan Kogyo Shimbun). It can be obtained by a method. The polytetrafluoroethylene micropowder obtained by the emulsion polymerization is agglomerated and dried, and is recovered as a fine powder as secondary particles with a primary particle size aggregated. Various fine powder production methods can be used.

The primary particle size of the polytetrafluoroethylene micropowder is 1 μm in volume-based average particle size (50% volume diameter, median diameter) measured by laser diffraction / scattering method, dynamic light scattering method, image imaging method, etc. The following is necessary for stable dispersion in an oily solvent. Desirably, the dispersion is made 0.5 μm or less, more desirably 0.3 μm or less, whereby a more uniform dispersion is obtained.
When the primary particle diameter of the polytetrafluoroethylene micropowder exceeds 1 μm, it is not preferable because it easily settles in an oily solvent and becomes difficult to disperse stably.
The lower limit of the average particle diameter is better as it is lower, but 0.05 μm or more is preferable from the viewpoint of manufacturability and cost.
The primary particle diameter of the polytetrafluoroethylene micropowder in the present invention indicates a value obtained by a laser diffraction / scattering method or a dynamic light scattering method in the polymerization stage of the micropowder. In the case of micropowder in powder form, the cohesion between primary particles is strong, and it is difficult to easily measure the primary particle size by laser diffraction / scattering method or dynamic light scattering method. The value obtained by may be indicated. As a measuring apparatus, for example, a dynamic light scattering method using FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.), a laser diffraction / scattering method using Microtrack (manufactured by Nikkiso Co., Ltd.), or a Macview (manufactured by Mountec Co., Ltd.). Examples thereof include an image imaging method.

In the present invention, the polytetrafluoroethylene micropowder is contained in an amount of 5 to 70% by mass, preferably 10 to 50% by mass, based on the total amount of the dispersion.
When this content is less than 5% by mass, the amount of the oily solvent is large and the viscosity is extremely lowered, so that the fine particles of the polytetrafluoroethylene micropowder not only easily settle, but also a material such as a resin. When mixed, problems due to a large amount of the oil-based solvent, for example, an unfavorable situation such as time-consuming removal of the solvent may occur. On the other hand, if it exceeds 70% by mass, the polytetrafluoroethylene micropowder tends to aggregate together, and it becomes extremely difficult to stably maintain the state of fine particles in a state having fluidity. It is not preferable.

The fluorine-based additive in the present invention is required to have at least a fluorine-containing group and a lipophilic group, and is not particularly limited as long as it has at least a fluorine-containing group and a lipophilic group. In addition, a hydrophilic group may be contained.
By using a fluorine-based additive having at least a fluorine-containing group and an oleophilic group, the surface tension of an oily solvent serving as a dispersion medium is reduced, and the wettability with respect to the surface of polytetrafluoroethylene is improved, so that polytetrafluoroethylene micropowder In addition to improving the dispersibility of the polytetrafluoroethylene, the fluorine-containing group is adsorbed on the surface of the polytetrafluoroethylene, and the lipophilic group is extended into the oily solvent serving as a dispersion medium. Thus, the dispersion stability is further improved.
Examples of the fluorine-containing group include a perfluoroalkyl group and a perfluoroalkenyl group. Examples of the lipophilic group include one or more of an alkyl group, a phenyl group, and a siloxane group. Examples of the hydrophilic group include one or more of ethylene oxide, amide group, ketone group, carboxyl group, sulfone group and the like.
Specific examples of the fluorine-based additive that can be used include Surflon series (manufactured by AGC Seimi Chemical Co., Ltd.) such as Surflon S-611 containing perfluoroalkyl group, MegaFuck F-555, MegaFuck F-558, MegaFuck A Mega-Fuck series (manufactured by DIC) such as F-563 and a Unidyne series (manufactured by Daikin Industries) such as Unidyne DS-403N can be used.
These fluorine-based additives are appropriately selected depending on the type of polytetrafluoroethylene micropowder used and the oily solvent, but can be used alone or in combination of two or more. is there.

The content of the fluorine-based additive is 0.1 to 40% by mass with respect to the mass of the polytetrafluoroethylene micropowder, preferably 5 to 30% by mass, and more preferably The content is preferably 15 to 25% by mass.
If the content is less than 0.1% by mass relative to the mass of polytetrafluoroethylene, the surface of the polytetrafluoroethylene micropowder cannot be sufficiently wetted with an oily solvent, whereas if it exceeds 40% by mass, the surface is dispersed. It is not preferable because the foaming of the body becomes strong and the efficiency of dispersion is lowered, which may cause problems when the dispersion itself is handled and then mixed with a resin material.

In the oil-based solvent dispersion of polytetrafluoroethylene in the present invention, other surfactants can be used in combination with the above-mentioned fluorine-based additives within the range not impairing the effects of the present invention. .
For example, nonionic, anionic and cationic surfactants and nonionic, anionic and cationic polymeric surfactants can be used, but the present invention is not limited to these. Can do.

The oily solvent used in the present invention preferably has a water content by the Karl Fischer method of 20000 ppm or less [0 ≦ water content ≦ 20000 ppm].
In the present invention (including examples and the like to be described later), the measurement of water content by the Karl Fischer method is based on JIS K 0068: 2001 and was performed by MCU-610 (manufactured by Kyoto Electronics Industry Co., Ltd.).
Depending on the polarity of the oil-based solvent used, one having high compatibility with water is conceivable. However, when the water content is 20000 ppm or more, the dispersibility of polytetrafluoroethylene micropowder in the oil-based solvent is remarkably inhibited, and the viscosity increases It causes aggregation of particles.
In the present invention, by setting the water content in the oily solvent to 20000 ppm or less, it is possible to obtain a polytetrafluoroethylene oily solvent-based dispersion having a fine particle size, low viscosity, and excellent storage stability. .

Furthermore, the polytetrafluoroethylene oil-based solvent dispersion of the present invention preferably has a water content by the Karl Fischer method of 20000 ppm or less [0 ≦ water content ≦ 20000 ppm].
In addition to the amount of water contained in the oily solvent, the water contained in the material itself such as polytetrafluoroethylene micropowder and fluorine additives, and also in the manufacturing process in which polytetrafluoroethylene micropowder is dispersed in the oily solvent In the end, the polytetrafluoroethylene oil-based solvent dispersion is more excellent in storage stability by reducing the water content of the polytetrafluoroethylene oil-based solvent dispersion to 20000 ppm or less. be able to.

In order to set the water content of the oily solvent to 20000 ppm, a generally used dehydrating method of the oily solvent can be used. For example, molecular sieves or the like can be used. In addition, polytetrafluoroethylene can be used in a state in which the amount of water is sufficiently reduced by dehydration by heating or decompression.
Furthermore, it is possible to remove water using a molecular sieve or a membrane separation method after preparing an oily solvent-based dispersion of polytetrafluoroethylene. Any body can be used without particular limitation as long as it can reduce the water content of the body.

Examples of the oily solvent used in the present invention include γ-butyrolactone, acetone, methyl ethyl ketone, hexane, heptane, octane, 2-heptanone, cycloheptanone, cyclohexanone, cyclohexane, methylcyclohexane, ethylcyclohexane, methyl-n-pentyl ketone. , Methyl isobutyl ketone, methyl isopentyl 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 ether, propylene glycol Monoacetate, dipropylene glycol No acetate, propylene glycol diacetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, cyclohexyl acetate, ethyl 3-ethoxypropionate, dioxane, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, Butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetol, butyl phenyl ether, benzene, ethylbenzene, diethylbenzene, Pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesit Len, 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, Methylphenol monoglycidyl ether, ethylphenol monoglycidyl ether, butylphenol monoglycidyl ether, mineral spirit, 2-hydroxyethyl acrylate, tetrahydrofurfuryl acrylate, 4-vinylpyridine, N-methylpyrrolidone, 2-ethylhexyl acrylate, 2-hydroxyethyl Methacrylate, hydroxypropyl methacrylate, glycidyl methacrylate One solvent selected from the group consisting of rate, neopentyl glycol diacrylate, hexanediol diacrylate, trimethylolpropane triacrylate, methacrylate, methyl methacrylate, styrene, or two or more of these solvents is there.

In the present invention, the above-mentioned oily solvent is used, but it can be used in combination with other oily solvents or other oily solvents, and can be used (various resin materials, rubbers, adhesives). , Lubricant, grease, printing ink, paint, etc.) are selected.
The content of the oily solvent used is the balance of the polytetrafluoroethylene micropowder and the fluorine-based additive.

In the present invention, it is desirable that the average particle diameter of the polytetrafluoroethylene micropowder in the oily solvent dispersion is 1 μm or less by the laser diffraction / scattering method or the dynamic light scattering method.
Even when polytetrafluoroethylene micropowder having a primary particle size of 1 μm or less is used, the primary particles are usually aggregated to form micropowder having a particle size of 1 μm or more as secondary particles. By dispersing the secondary particles of the polytetrafluoroethylene so as to have a particle diameter of 1 μm or less, the dispersion is performed using a dispersing machine such as an ultrasonic dispersing machine, a three-roll, a ball mill, a bead mill, or a jet mill. Thus, a stable dispersion can be obtained even when stored for a long time at a low viscosity.

In the present invention, a silicone-based antifoaming agent can be further added to the oil-based solvent dispersion of polytetrafluoroethylene.
In particular, when the polytetrafluoroethylene micropowder is used at a high concentration of 70% by mass or the fluorine-based additive is used at a high concentration of 40% by mass with respect to the mass of the polytetrafluoroethylene micropowder, the foaming of the dispersion However, this leads to major problems during mixing with the dispersion manufacturing process, stability, resin material, and the like.

Antifoaming agents include silicone emulsion type, self-emulsifying type, oil type, oil compound type, solution type, powder type, solid type, etc., but the most suitable one is selected depending on the combination with the oily solvent used Will be. In particular, it is preferable to use, for example, a hydrophilic or water-soluble silicone-based antifoaming agent in order to exist at the interface between the oily solvent and air rather than the interface between the oily solvent and polytetrafluoroethylene micropowder. Without being limited to these, it can be used. The content of the antifoaming agent varies depending on the content (concentration) of polytetrafluoroethylene micropowder and the like, but is preferably 1% by mass or less as an active ingredient with respect to the total amount of the dispersion.

The polytetrafluoroethylene oily solvent-based dispersion of the present invention configured as described above includes a polytetrafluoroethylene micropowder having a primary particle diameter of 1 μm or less, and a fluorine-based dispersion containing at least a fluorine-containing group and a lipophilic group. By using each specific amount with the additive, the particle size is low, the viscosity is low, and the storage stability is excellent, and the redispersibility is excellent even after long-term storage. In addition, even if it contains a lot of fluorine-based additives, it has excellent antifoaming properties, and evenly mixed when added to various resin materials, rubber, adhesives, lubricants, greases, printing inks, paints, etc. Will be able to.
Accordingly, the oil-based solvent dispersion of polytetrafluoroethylene of the present invention can be added to a resist material such as a photoresist such as a color filter or a black matrix, or a screen printing resist, and can also be used as a substrate or sealing material for electronic equipment. By adding it to the widely used epoxy resin material, it is possible to further lower the dielectric constant and lower the dielectric loss tangent, so that it can be suitably used for resist material addition and epoxy resin material addition it can.

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

[Examples 1 to 8 and Comparative Examples 1 to 7]
Each polytetrafluoroethylene oil-based solvent dispersion was prepared by the following methods. Moreover, about the oil-based solvent to be used, the oil-based solvent used as a water | moisture content is obtained by adding molecular sieves or a water | moisture content. The blending compositions of Examples 1 to 8 and Comparative Examples 1 to 7 are shown in Table 1 below.

Example 1
As polytetrafluoroethylene micropowder, a powder having an average particle diameter of 0.12 μm by laser diffraction / scattering method was used. As the fluorine-based additive, Megafac F-558 (fluorine-containing / lipophilic group-containing oligomer, active ingredient 30 wt%) manufactured by DIC Corporation was used after removing the diluent solvent. In addition, cyclohexanone was used as the oily solvent.

Using the above materials, an oil-based solvent dispersion of polytetrafluoroethylene was prepared according to the formulation shown in Table 1 below. In production, the fluorine-based additive was sufficiently stirred and mixed in the oily solvent, and then polytetrafluoroethylene micropowder was added and further stirred and mixed.
The polytetrafluoroethylene micropowder mixture obtained as described above was dispersed with zirconia beads having a diameter of 0.3 mm using a horizontal bead mill.

The obtained dispersion was subjected to filter filtration in order to remove coarse particles of 1 μm or more to obtain an oily solvent-based dispersion of polytetrafluoroethylene.

(Example 2)
A dispersion was prepared in the same manner as in Example 1 except that the amounts of polytetrafluoroethylene micropowder and fluorine-based additive were varied, and the diameter of the zirconia beads was 1 mm.

Example 3
A dispersion was produced in the same manner as in Example 1 except that the average particle size of the polytetrafluoroethylene micropowder was 0.8 μm.

Example 4
KM-72 (0.05% by mass) made by Shin-Etsu Silicone was added as a silicone-based antifoaming agent after being dispersed in the bead mill, mixed thoroughly and mixed, and then filtered in the same manner as in Example 1. A dispersion was prepared.

(Example 5)
A dispersion was produced in the same manner as in Example 1 except that propylene glycol monomethyl ether acetate (PGMEA) was used as the oily solvent.

(Example 6)
As the fluorine-based additive, the same as in Example 1 except that Megafac F-563 (fluorine-containing / lipophilic group-containing oligomer) manufactured by DIC Corporation was 9% by mass and methyl ethyl ketone was used as the oily solvent. A dispersion was prepared by the method described above.

(Example 7)
A dispersion was produced in the same manner as in Example 1 except that cyclohexanone was used by forcibly adding water as an oily solvent.

(Example 8)
Executed except that Megafac F-555 (fluorinated group / hydrophilic group / lipophilic group-containing oligomer, active ingredient 30 wt%) manufactured by DIC Corporation was used as the fluorosurfactant after removing the diluting solvent. A dispersion was produced in the same manner as in Example 1.

(Comparative Example 1)
A dispersion was prepared in the same manner as in Example 1, and then water was forcibly added to obtain a dispersion.

(Comparative Example 2)
A dispersion was produced in the same manner as in Example 1 except that the average particle size of the polytetrafluoroethylene micropowder was 1.2 μm and filtration was not performed after dispersion.

(Comparative Example 3)
A dispersion was prepared in the same manner as in Example 1 except that the water that was forcibly added to cyclohexanone and sufficiently stirred was used as the oily solvent.

(Comparative Example 4)
Except for the amount of the fluorine-based additive Megafac F-558 being 0.025% by mass (with respect to polytetrafluoroethylene micropowder, less than 0.1% by mass), the same method as in Example 1 was used. A dispersion was prepared.

(Comparative Example 5)
Example 1 except that 75% by mass of polytetrafluoroethylene micropowder was added, and MegaFac F-563 (fluorine-containing / lipophilic group-containing oligomer) manufactured by DIC Corporation was used as a fluorine-based additive. An attempt was made to prepare a dispersion by the same method as described above.

(Comparative Example 6)
A dispersion was prepared in the same manner as in Example 1, and then water was forcibly added to obtain a dispersion.

(Comparative Example 7)
A dispersion was prepared in the same manner as in Example 1 except that 75% by mass of polytetrafluoroethylene micropowder was added.

The oil-based solvent dispersions of polytetrafluoroethylene obtained in Examples 1 to 8 and Comparative Examples 1 to 7 were redispersed after storage at 25 ° C. for 1 month according to the following evaluation methods. Property and antifoaming properties were evaluated.
These results are shown in Table 1 below.

(Evaluation method of fluidity of dispersion)
Spreading of the obtained oil-based solvent dispersion of each polytetrafluoroethylene on a PET film with a dropper, and dispersion when tilted 90 degrees suddenly from the standing state in the bottle From the state of movement of the body, the following evaluation criteria were evaluated visually.
Evaluation criteria:
○: Flows smoothly.
(Triangle | delta): It has structural viscosity.
X: Almost no flow.

(Redispersibility evaluation method)
The obtained oil-based solvent dispersions of polytetrafluoroethylene were put in a glass container with a lid (30 ml, the same applies hereinafter), and the redispersibility after storage at 25 ° C. for 1 month was evaluated according to the following evaluation criteria.
Evaluation criteria:
○: Redispersed easily.
Δ: Redispersed.
X: Sufficient stirring is required for redispersion.

(Evaluation method of defoaming properties)
After the obtained oil-based solvent dispersion of polytetrafluoroethylene was sealed in a glass container with a lid, the state of foam after being sufficiently stirred up and down and left and left for 2 minutes was evaluated according to the following evaluation criteria. did.
Evaluation criteria:
○: Almost disappeared.
Δ: Remaining.
×: Does not disappear.

As can be seen from Table 1 above, Examples 1 to 8 within the scope of the present invention were found to have good dispersion fluidity and high storage stability. Example 7, which is within the scope of the present invention, could be redispersed even after storage at 25 ° C. for one month, but Comparative Example 1 and Comparative Examples 3 and 5 having a water content exceeding 20000 ppm were redispersed. Required sufficient agitation. In addition, it was found that Example 4 containing an antifoaming agent also had good foam breakage.
On the other hand, it was found that Comparative Examples 1 to 7 outside the scope of the present invention are inferior in fluidity and storage stability. Further, Comparative Examples 5 and 7 could not be dispersed because the polytetrafluoroethylene micropowder was as large as 75% by mass.

[Test Example 1: Test for adding resist material]
Furthermore, using the polytetrafluoroethylene oil-based solvent-based dispersion for adding a resist material obtained in Example 5 above, a photosensitive resin composition having a photopolymerizable monomer with reference to Patent Documents 6 and 7, etc. After forming a thin film by mixing with a product, it was found that a pattern could be formed by exposure and development. Moreover, when the dielectric constant of the film after curing was measured, it was found that the reduction of the dielectric constant could be adjusted according to the amount added.

[Test Examples 2 to 5: Test for addition of epoxy resin material]
Furthermore, using the oil-based solvent dispersion of polytetrafluoroethylene obtained in Example 1 above, after mixing with the epoxy resin material at each blending amount shown in Table 2 below, the oil-based solvent is heated and removed, Cured at a temperature of 180 ° C. for 8 hours to obtain a cured product.
For each of the cured epoxy products of Test Examples 2 to 5, the relative dielectric constant at 23 ° C. and 1 GHz was measured using a material analyzer 4291B (manufactured by Agilent Technologies).
These results are shown in Table 2 below.

Each of the epoxy cured products of Test Examples 2 to 5 shown in Table 2 above can be cured, and from Test Example 2 not containing a polytetrafluoroethylene oil-based dispersion, the addition amount of Comparative Examples 3 to 5 is It has also been found that the relative permittivity can be reduced as it increases.

The oil-based solvent dispersion of polytetrafluoroethylene in the present invention is a substrate composed of various resin materials, for example, resist materials used for color filters and black matrices, epoxy resin materials used for electronic devices, etc. It is uniformly added to each material such as sealant and insulating material, rubber, adhesive, lubricant, grease, printing ink and paint, etc. to improve the electrical characteristics or to give the characteristics possessed by polytetrafluoroethylene Thus, it can be used for the purpose of improving various product characteristics, and can be used for electronic devices, sliding materials, automobiles, kitchen utensils and the like.

Claims (6)

5 to 70% by mass of polytetrafluoroethylene micropowder having a primary particle size of 1 μm or less, and 0.1 wt.% Of a fluorine-containing additive containing at least a fluorine-containing group and a lipophilic group to the mass of polytetrafluoroethylene micropowder. An oily solvent-based dispersion of polytetrafluoroethylene, characterized in that it contains ˜40% by mass, and the total water content by the Karl Fischer method is 20000 ppm or less. 2. The oil-based solvent dispersion of polytetrafluoroethylene according to claim 1, wherein the oil-based solvent used in the oil-based solvent-based dispersion has a water content by a Karl Fischer method of 20000 ppm or less. The oily solvent used in the oily solvent dispersion is γ-butyrolactone, acetone, methyl ethyl ketone, hexane, heptane, octane, 2-heptanone, cycloheptanone, cyclohexanone, cyclohexane, methylcyclohexane, ethylcyclohexane, methyl-n-pentyl ketone. , Methyl isobutyl ketone, methyl isopentyl 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 ether, propylene glycol Monoacetate, dipropylene glycol mono Cetate, propylene glycol diacetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, cyclohexyl acetate, ethyl 3-ethoxypropionate, dioxane, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, acetic acid Butyl, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetol, butyl phenyl ether, benzene, ethylbenzene, diethylbenzene, pentyl Benzene, isopropylbenzene, toluene, xylene, cymene, 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, ethylphenol monoglycidyl ether, butylphenol monoglycidyl ether, mineral spirit, 2-hydroxyethyl acrylate, tetrahydrofurfuryl acrylate, 4-vinylpyridine, N-methylpyrrolidone, 2-ethylhexyl acrylate, 2-hydroxyethyl methacrylate , Hydroxypropyl methacrylate, glycidyl methacrylate 1 type of solvent selected from the group consisting of thione, neopentyl glycol diacrylate, hexanediol diacrylate, trimethylolpropane triacrylate, methacrylate, methyl methacrylate, styrene, or two or more of these solvents The oily solvent-based dispersion of polytetrafluoroethylene according to claim 1 or 2. The average particle diameter of the polytetrafluoroethylene micropowder in the oil-based solvent-based dispersion by a laser diffraction / scattering method or a dynamic light scattering method is 1 μm or less, according to any one of claims 1 to 3 An oily solvent-based dispersion of the polytetrafluoroethylene described. The oil-based solvent-based dispersion of polytetrafluoroethylene according to any one of claims 1 to 4, further comprising a silicone-based antifoaming agent. The oil-based solvent dispersion of polytetrafluoroethylene according to any one of claims 1 to 5, wherein the oil-based solvent dispersion of polytetrafluoroethylene is used for addition of a resist material or an epoxy resin material. body.