JP2019052211A - Fluororesin water dispersion - Google Patents

Abstract

To provide a fluororesin water dispersion that has excellent dispersibility and redispersibility, has excellent water repellency, oil repellency, slidability, electric characteristics or the like, and contains fluororesin particles such as polytetrafluoroethylene (PTFE) particles, and provide a coating layer and a composite plating layer wherein the fluororesin water dispersion is used for a plating solution such as a coating liquid or a composite plating solution, to give the material surface the characteristic functions of fluororesin particles, including water repellency, oil repellency, electric characteristics, high slidability, electric characteristics or the like.SOLUTION: A fluororesin water dispersion comprises 1-80 mass% of fluororesin particles wherein a post-dispersion volume average particle diameter Dv is 1 μm-50 μm. A coating layer and a composite plating layer are formed with the fluororesin water dispersion.SELECTED DRAWING: None

Description

  The present invention relates to a fluororesin aqueous dispersion containing fluororesin particles such as polytetrafluoroethylene (PTFE) particles having excellent water repellency, oil repellency, slidability, electrical properties, and the like. The present invention relates to a fluororesin aqueous dispersion that can be suitably used for a plating solution such as the above.

Conventionally, in order to impart slidability and the like to a thermoplastic resin, a mixture of fluorine resin particles such as polytetrafluoroethylene (PTFE) at the time of melt kneading has been commercialized (manufactured by Mitsubishi Engineering Plastics, Iupilon). LSH series).
These usually have fluorine resin particles with a primary particle diameter of several μm to several tens of μm and are dispersed during melt-kneading, so the fluorine resin protrudes from the surface of the thermoplastic resin on the order of μm, and the function of the fluorine resin. Can be sufficiently imparted to the thermoplastic resin. However, its application range has been limited to thermoplastic resins.

  On the other hand, as a method of incorporating fluororesin particles such as PTFE particles that are fluororesin particles into a thin film layer such as a coating layer or a composite plating layer, water in which 0.1 to 0.3 μm of PTFE or the like is dispersed is used. It is known that a dispersion is added to a varnish or a composite plating solution and co-deposited as a coating film or a fluorine resin particle composite plating film such as PTFE. PTFE of an aqueous dispersion such as PTFE existing in the world is known. Is a fine particle having a dispersion average particle diameter of 0.1 to 0.3 μm, etc., so that it is not sufficiently exposed to the coating or composite plating surface, and the water repellency and sliding inherent in fluorine resin particles such as PTFE It was not possible to impart sex and the like.

  Moreover, as a method for solving the above-mentioned point, etc., it can be solved by using fluorine-based resin particles having a dispersion average particle diameter exceeding 1 μm. However, fluorine-based resin particles exceeding 1 μm can quickly form a hard cake. In order to form, it was necessary to mix immediately before using a varnish or a composite plating solution, and it was difficult for those skilled in the art to use it widely.

  On the other hand, as prior arts such as conventional aqueous dispersions containing fluorine-based resin particles and plating solutions using the same, for example, 1) including low-viscosity silicone glycol surfactants and polytetrafluoroethylene powder An aqueous polytetrafluoroethylene dispersion, an electroless nickel plating bath using the same (see, for example, Patent Document 1), 2) Teflon eutectoid electroless nickel plating is applied to the inner surface of a cylindrical mold. Mold for resin roller molding, and the above-mentioned Teflon eutectoid electroless nickel plating to which a softener, a plasticizer and the like are added for the purpose of adjusting viscosity (for example, refer to Patent Document 2), 3) Ni— on the surface In a corrosion-resistant surface treatment chain in which a nickel-based film made of a P-based alloy or the like is formed, PTFE or the like is included as a lubricant in a plating film made of a Ni-P-based alloy or the like Corrosion-resistant surface treatment chain formed with a composite alloy film such as i-P-PTFE (see, for example, Patent Document 3), 4) Electro nickel plating solution for forming a fluororesin particle-dispersed nickel plating film by electroplating. An electronickel plating solution comprising a fluororesin particle and a fluorosurfactant containing a perfluoroalkenyl group as a hydrophobic group and a bromine salt of quaternary ammonium as a hydrophilic group (for example, patent document) 4) is known.

  However, the aqueous dispersion containing the fluorine-based resin particles of Patent Documents 1 to 4 above, such as a plating solution using this, the fluorine-based resin particles are not yet sufficiently exposed to the coating or composite plating surface, and PTFE However, there is a problem in that the water-repellent property and slidability inherent in the fluororesin particles cannot be imparted.

JP-T-2007-501332 (Claims, Examples, etc.) JP-A-2005-297249 (Claims, Examples, etc.) JP 2011-148859 A (Claims, Examples, etc.) JP-T-2014-224314 (Patents, Examples, etc.)

  The present invention is intended to solve the above-mentioned conventional problems and the like. Polytetrafluoroethylene (excellent in dispersibility and redispersibility, excellent in water repellency, oil repellency, slidability, electrical properties, etc.) Fluorine resin water dispersion containing fluorine resin particles such as (PTFE) particles, and by using this in plating liquids such as coating liquids and composite plating liquids, functions unique to the fluorine resin particles on the material surface An object of the present invention is to provide a coating layer and a composite plating layer imparted with water repellency, oil repellency, electrical properties, high slidability, electrical properties and the like.

  As a result of intensive studies on the above-described conventional problems and the like, the present inventors have included the above-mentioned target fluorine-based resin particles by containing the fluorine-based resin particles having a volume average particle diameter Dv after dispersion in a specific range. It has been found that a resin water dispersion can be obtained, and by using this fluororesin water dispersion for a coating solution or a composite plating solution, it has been found that the above-mentioned target coating layer or composite plating layer can be obtained. The invention has been completed.

That is, the aqueous fluororesin dispersion of the present invention contains 1 to 80% by mass of fluororesin particles having a volume average particle diameter Dv after dispersion of 1 μm to 50 μm.
It is preferable to contain 0.01-5 mass% of water-soluble thickeners.
It is preferable the ratio of the viscosity B of viscosity A and a shear rate of 38.3s ^-1 at a shear rate of 3.83s ^-1 in the fluororesin aqueous dispersion, B / A is less than 0.7.
It is preferable to contain 0.3-30 mass% of nonionic surfactants whose weight average molecular weight Mw is less than 100,000.
It is preferable that an amine is contained as a pH adjuster and the pH is 8.5 or more, and that no preservative, fungicide or antibacterial agent is contained in an amount of 0.5% by mass or more.
The fluorine resin particles are preferably polytetrafluoroethylene.
The coating layer of the present invention is formed using the fluororesin aqueous dispersion having the above-described configuration.
In the coating layer, it is preferable that the volume average particle diameter Dv of the fluorinated resin particles after dispersion and the thickness T1 of the coating layer containing the fluorinated resin particles are adjusted in a range satisfying the following formula (I). .
0.5T1 ≦ Dv ≦ 4T1 (I)
The composite plating layer of the present invention is formed using the fluororesin aqueous dispersion having the above-described configuration.
In the composite plating layer, the volume average particle diameter Dv of the fluorine-based resin particles after dispersion and the thickness T2 of the composite plating layer containing the fluorine-based resin particles are adjusted in a range satisfying the following formula (II). Is preferred.
0.5T2 ≦ Dv ≦ 4T2 (II)

  According to the present invention, a fluorine resin containing fluorine resin particles such as polytetrafluoroethylene (PTFE) particles having excellent dispersibility, redispersibility, water repellency, oil repellency, slidability, electrical properties, and the like. By using this dispersion in a plating solution such as a coating solution or a composite plating solution, water repellency, oil repellency, electrical properties, high sliding, which are functions specific to fluororesin particles, are used on the surface of the material. A coating layer and a composite plating layer imparted with properties and electrical characteristics are provided.

Hereinafter, embodiments of the present invention will be described in detail.
The aqueous fluororesin dispersion of the present invention is characterized by containing 1 to 80% by mass of fluororesin particles having a volume average particle diameter Dv after dispersion of 1 μm to 50 μm.

<Fluorine resin particles>
Examples of the fluorine resin particles that can be used in the present invention include polytetrafluoroethylene (PTFE), fluorinated ethylene-propylene copolymer (FEP), perfluoroalkoxy polymer (PFA), and ethylene-tetrafluoroethylene. Copolymer (ETFE), Chlorotrifluoroethylene copolymer (CTFE), Tetrafluoroethylene-chlorotrifluoroethylene copolymer (TFE / CTFE), Ethylene-chlorotrifluoroethylene copolymer (ECTFE), Polychloro Examples of the fluororesin particles include at least one selected from the group consisting of trifluoroethylene (PCTFE) and polyvinylidene fluoride resin (PVDF) (each single or a mixture of two or more, and the same applies hereinafter).
Among the fluororesin particles, polytetrafluoroethylene (PTFE) particles, ethylene-tetrafluoroethylene copolymer (ETFE) particles, and polyfluoride particles that are extremely excellent in water repellency, oil repellency, slidability, electrical properties, etc. The use of vinylidene resin (PVDF) particles is desirable.
Such fluorine-based resin particles such as polytetrafluoroethylene are obtained by an emulsion polymerization method. For example, a general method such as a method described in a fluorine resin handbook (edited by Takaomi Satokawa, Nikkan Kogyo Shimbun) Can be obtained by the method used in the above. The fluororesin particles obtained by the emulsion polymerization are aggregated and dried, and are recovered as fine particles as secondary particles having a primary particle size aggregated. The manufacturing method of a fluorine resin particle can be used.

The primary particle diameter and specific surface area of the fluorine resin particles such as PTFE particles used in the present invention may be fluorine resin particles having a volume average particle diameter Dv after dispersion of 1 μm to 50 μm.
It is preferable that the specific surface area of the fluororesin particles such as PTFE particles to be used is 6.0 m ² / g or less, more preferably 0.1 to 5.0 m ² / g, particularly preferably 0.0. It is desirable that it is 3-4.0 m < ² > / g.
In the present invention (including examples to be described later), the volume average particle diameter Dv is a value measured using a Nikkiso Co., Ltd. Microtrac MT3000. In the present invention (including examples described later), the “specific surface area” is a value obtained by the gas adsorption method using the BET equation.
If the specific surface area of the fluororesin resin particles such as PTFE exceeds 6.0 m ² / g, it is difficult to adjust the volume average particle diameter Dv after dispersion to 1 μm to 50 μm.

The content of these fluorine-based resin particles varies depending on the use of the fluorine-based resin water dispersion, but is 1 to 80% by mass (hereinafter referred to as “% by mass” with respect to the total amount of the fluorine-based resin water dispersion). "Is referred to as"% "), preferably 10 to 65%.
If the content of the fluorine resin particles is less than 1%, the effect of the present invention cannot be exhibited. On the other hand, if the content exceeds 80%, the viscosity becomes too high and the usability is inferior. It may not be possible.

The fluororesin aqueous dispersion of the present invention preferably contains a water-soluble thickener from the viewpoint of improving dispersibility and redispersibility and suppressing sedimentation.
As the thickener that can be used, for example, at least one selected from the group consisting of synthetic polymers such as polyacrylic acids and polyvinyl alcohol, polysaccharides, and celluloses can be used.
Examples of synthetic polymers include polyacrylic acids, polyvinyl alcohol, polyethylene oxide, polyvinyl pyrrolidone, polyvinyl methyl ether, bisacrylamide methyl ether, polyacrylamide, polyethyleneimine, polyethylene glycol, polydioxolane, polystyrene sulfonic acid, and polypropylene oxide. Can be mentioned.
Polysaccharides include xanthan gum, guar gum, casein, gum arabic, gelatin, amylose, agarose, agaropectin, arabinan, curdlan, callose, carboxymethyl starch, chitin, chitosan, quince seed, glucomannan, gellan gum, tamarin seed gum, dextran , Nigeran, hyaluronic acid, pustulan, funolan, pectin, porphyran, laminaran, lichenan, carrageenan, alginic acid, tragacanth gum, archaic gum, locust bean gum and the like.
Examples of celluloses include ethyl cellulose, methyl cellulose, hydroxypropyl cellulose, hydroxymethyl cellulose, carboxymethyl cellulose, crystalline cellulose, and oxidized cellulose.

These water-soluble thickeners are not formulated for the purpose of adsorbing on the fluororesin resin to assist wetting or to obtain repulsive force. A matrix is formed so as to be surrounded by chains or the like, and is blended for the purpose of alleviating caking and aggregation of the fluororesin particles. The technical idea is different from the dispersion stability of a normal dispersant. The water-soluble thickener can be selected from synthetic polymers such as the above polyacrylic acids and polyvinyl alcohol, celluloses such as polysaccharides and oxidized cellulose, and other materials may be used as long as they satisfy the above technical idea. it can.
The content of these water-soluble thickeners is 0.01 to 5%, preferably 0.1 to 3%, based on the total amount of the fluororesin aqueous dispersion.
If the content of the water-soluble thickener is less than 0.01%, the dispersibility and redispersibility cannot be improved and the settling can not be suppressed. On the other hand, if the content exceeds 5%, the viscosity is remarkably increased. This is not preferable because handling during actual use is impaired, and problems such as deterioration in yield during production also occur.

The fluororesin aqueous dispersion of the present invention preferably contains a nonionic surfactant having a weight average molecular weight Mw of less than 100,000 from the viewpoint of improving dispersibility and excellent fluidity.
Examples of the nonionic surfactant that can be used include polyoxyethylene alkyl ether, polyoxyalkylene alkyl ether, polyoxyethylene polycyclic phenyl ether, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl. Ether, polyoxyethylene alkylamine, polyoxyethylene alkylamide, acetylene glycol, acetylene alcohol, a fluorine-based additive having at least a fluorine-containing group and a hydrophilic group, a silicone-based additive containing a modified polysiloxane, a polyester-based additive, Examples thereof include at least one of a silicon-modified acrylate, an acrylic additive, a polyurethane additive, and a styrene acrylic additive.
These nonionic surfactants are required to have a weight average molecular weight Mw of less than 100,000 from the viewpoint of proper adsorption to the surface of the fluororesin particles and securing fluidity in a high shear region, and preferably Preferably has a weight average molecular weight Mw of 5,000 to 80,000. In the present invention, “weight average molecular weight” means a molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).
When a nonionic surfactant having a weight average molecular weight Mw of 100,000 or more is used, the viscosity of the dispersion increases, and there is a possibility that handling becomes impossible when used on site. Moreover, since it may become impossible to process with a disperser in manufacture of a dispersion, it is unpreferable.
In addition, cationic and anionic active agents are not preferable because they may cause aggregation of fluorine-based resin particles due to the influence of ions contained therein or pH change when blended in a coating solution or a composite plating solution. . However, in addition to the nonionic surfactant, if necessary, a combination of a plurality of amphoteric surfactants such as cationic, anionic or betaine can greatly reduce the aggregation risk.

As the nonionic surfactant having the above characteristics that can be preferably used, a fluorine-based additive having at least a fluorine-containing group and a hydrophilic group is suitable.
Examples of the fluorine-containing group include a perfluoroalkyl group and a perfluoroalkenyl group. Examples of the hydrophilic group include ethylene oxide, amide group, ketone group, carboxyl group, sulfone group, and the like. Two or more types can be mentioned.
As a fluorine-based additive having at least a fluorine-containing group and a hydrophilic group that can be specifically used, among commercially available megafluoro series containing perfluoroalkyl groups (manufactured by DIC), Megafac F-553, Among the perfluoroalkyl group-containing tangent series (manufactured by Neos) such as MegaFuck F-556 and MegaFuck F-562, FT 683 and the like can be used.

The content of these nonionic surfactants is 0.3 to 30%, preferably 0.5 to 15% by mass, based on the total amount of the fluororesin aqueous dispersion.
If the content of this nonionic surfactant is less than 0.3%, there is a risk of poor dispersion. On the other hand, if it exceeds 30%, the viscosity of the dispersion becomes high, and there is a possibility that handling becomes impossible during use in the field. Moreover, since it may become impossible to process with a disperser in manufacture of a dispersion, it is unpreferable. However, it is possible to ensure fluidity by suppressing the amount of fluorine resin particles to a low level and increasing the ratio of ion-exchanged water in the dispersion. However, a dispersion having a low fluorine resin particle concentration is not preferable because it is uneconomical from the viewpoint of production and transportation.

The fluororesin aqueous dispersion of the present invention preferably contains an amine as a pH adjuster and has a pH of 8.5 or more from the viewpoint of storage stability.
When the pH is less than 8.5, molds grow on the dispersion, and germs grow and spoil, causing extra costs such as refrigeration. Although it is possible to adjust to an acidic area where mold and germs do not propagate, many industrial facilities use stainless steel for the wetted parts, so extra costs are incurred, such as requiring a lining treatment for the wetted parts I will let you.
Examples of amines that can be used include, as specific examples of amines, secondary amines such as monoethanolamine, diethanolamine, dimethylamine, diethylamine, diisopropylamine, and dicyclohexylamine, triethanolamine, tripropanolamine, and triethylamine. , Tertiary amines such as tripropylamine, tributylamine, triamylamine, pyridine, N-methylmorpholine, quaternary ammonium hydroxides of tetramethyl, tetraethyl, tetrapropyl, tetrabutyl, tetraamyl, tetrahexyl, benzyltrimethyl, etc. At least one of them.
The content of these amines may be an amount such that the pH of the fluororesin aqueous dispersion is in the above range, and a suitable amount can be contained.
The pH adjuster contained is an amine, and pH adjusters containing metal ions such as sodium hydroxide may cause aggregation of fluororesin particles when blended in a coating solution or a composite plating solution. This is not preferable. However, a pH adjusting agent other than amines may be used if a combination that does not cause a problem with a specific ion such as sodium is sufficiently considered. However, the versatility to deal with many coating solutions and composite plating solutions is limited.

The fluororesin aqueous dispersion of the present invention contains at least one selected from a preservative, a fungicide, or a fungicide from the viewpoint of storage stability and prevention of spoilage due to secondary contamination. It is preferable that 0.5% or more is not included from the viewpoint of adaptability to a coating solution or a composite plating solution, and more preferably 0.1 to 0.3%.
Preservatives against molds and germs can be enhanced by preservatives, fungicides, or antibacterial agents, but coating and composites such as agglomeration of fluororesin particles when incorporated in coating solutions and composite plating solutions There is a risk that plating may damage the properties that are originally required. In particular, when 0.5% or more of a preservative, a fungicide, a fungicide, or the like is blended, the risk increases.

Examples of preservatives include phenol, sodium omadin, sodium pentachlorophenol, 1,2-benzisothiazolin-3-one, 2,3,5,6-tetrachloro-4 (methylsulfonyl) pyridine, and benzimidazole series. Compounds, and alkali metal salts of benzoic acid, sorbitan acid, and dehydroacetic acid.
Examples of the antibacterial agent include alcohols such as ethanol, hypochlorite, N-chloramines, iodine, copper compounds, zinc compounds, silver compounds, peroxides, bis (hydroxyphenyl) alkanes, 8-hydroxys. In addition to known antimicrobial active ingredients such as quinoline and its derivatives, quaternary ammonium related compounds, carbamic acid and urea derivatives, ethylene oxide, propylene oxide, etc., known antibacterial agents such as halogen compounds, quaternary ammonium compounds, etc. Can be mentioned.
As the fungicides, known ones can be used. Specific examples include, in addition to the known antimicrobial active ingredients, isothiazolone compounds or inclusion compounds of isothiazolone compounds. Moreover, in these antiseptic | preservative, antifungal agent, or antibacterial agent, if there exists a commercial item, they can be used.

In the fluororesin water dispersion of the present invention, water (ion exchange water, distilled water, purified water, pure water, ultrapure water, tap water, etc.) is used as a dispersion medium, but further improves the storage stability. From the viewpoint of assisting the solubility of a material having low solubility in water and promoting the wetting of the fluororesin particles, it is preferable to contain a water-soluble solvent and a dispersant.
Examples of water-soluble solvents that can be used include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, 1,2-propanediol, 1,3-prompandiol, and 1,2-butanediol. 2,3-butanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,5-pentanediol, 2,5-hexanediol, 3-methyl-1,3- Butanediol, 2methylpentane-2,4-diol, 3-methylpentane-1,3,5 triol, 1,2,3-hexanetriol, glycerin, polyethylene glycol, polypropylene glycol, glycerol, diglycerol, triglycerol, Ethylene glycol mono Chill ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, thiodiethanol, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, methyl alcohol, ethyl alcohol , Isopropyl alcohol, n-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, hexyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, benzyl alcohol and the like.
The content of these water-soluble solvents is preferably based on the total amount of the fluororesin aqueous dispersion,
It is preferable to set it as 3 to 10%.

The dispersant that can be used is not particularly limited as long as it can uniformly and stably disperse the fluororesin particles, and various dispersants can be used.
Preferably, the dispersant used from the viewpoint of further improving dispersibility preferably has an acid value, and the dispersant has a weight average molecular weight of 3000 to 50,000, more preferably 5000 to 30,000. Is desirable. In the present invention (including examples and the like to be described later), “acid value” represents the weight (unit, mg) of KOH necessary to neutralize the acid contained in 1 g of the dispersant. The certain acid value (unit: mg · KOH / g) is measured by a method based on JIS K 2501-2003.
Preferable dispersants include acrylic copolymers, polyester copolymers, and the like. Dispersbyk-180, 184, 187, 190, 191, 192, 194, 199, 2010 manufactured by Big Chemie are commercially available products. 2012, 2013, 2015, 2055, 2060, 2061, 2096, EFKA-4550, 4575, 4585, 4560 manufactured by BASF, BR3, A122, 123K, P30, P90 manufactured by COATEX, etc. can be used. .
The content of these dispersants is preferably 0.5 to 15% with respect to the total amount of the fluororesin aqueous dispersion.

The fluororesin aqueous dispersion of the present invention can be obtained by mixing the above fluororesin particles and, if necessary, additives such as a water-soluble thickener, a nonionic surfactant, a pH adjuster and a preservative. . As a mixing method, a normal kneading method can be employed.
In the present invention, point the ratio of the viscosity B of viscosity A and a shear rate of 38.3s ^-1 at a shear rate of 3.83s ^-1 in the fluororesin aqueous dispersion, B / A is the precipitation inhibition of the fluorine resin particles From the viewpoint of improving the handling of the fluororesin particle aqueous dispersion at the work site, it is preferably less than 0.7, more preferably 0.1 to 0.5.
In the present invention, the viscosity is measured using a cone plate viscometer at a shear rate of 3.83 s ⁻¹ (1 rpm) and a shear rate of 38.3 s ⁻¹ (10 rpm). B / A).
In order to make the range of the viscosity ratio, the amount of the fluorine resin particles, the amount of the water-soluble thickener, etc. are suitably combined, and the fluorine resin water dispersion that becomes less than the viscosity ratio by a suitable mixing method or the like. You can get a body.

The fluororesin aqueous dispersion of the present invention configured as described above is characterized by containing 1 to 80% of fluororesin particles having a volume average particle diameter Dv after dispersion of 1 μm to 50 μm. By providing a fluororesin aqueous dispersion suitable for applications such as coating layers or composite plating layers, the function of the fluororesin particles can be utilized to the maximum. Furthermore, it is preferable to use PTFE as the fluorine resin particles. This is because the function imparting ability to PTFE coating and composite plating is the highest among the fluororesin particles.
Therefore, according to the present invention, polytetrafluoroethylene (PTFE) particles, polyvinylidene fluoride resin (PVDF), etc. that are excellent in dispersibility and redispersibility, and excellent in water repellency, oil repellency, slidability, electrical properties, etc. A fluororesin aqueous dispersion containing fluororesin particles can be obtained. As will be described later, by using this as a raw material for a plating solution such as a coating solution or a composite plating solution, the surface of the coating or composite plating can be obtained. It is possible to obtain a coating layer, a composite plating layer, and the like that can sufficiently expose the fluorine-based resin particles and can sufficiently exhibit the water repellency, slidability, etc. inherent to the fluorine-based resin particles such as PTFE.

The coating layer, composite plating layer, and the like of the present invention are formed using the fluororesin aqueous dispersion having the above-described configuration.
In the present invention, the fluororesin particles are prepared by preparing a plating solution such as a coating solution and a composite plating solution using the fluororesin aqueous dispersion having the above-described configuration, and coating and plating the surface of the material. A coating layer, a plating layer, or a composite plating layer imparted with water repellency, oil repellency, electrical properties, high slidability, electrical properties and the like, which are unique functions, can be obtained.
As a material for forming the coating layer, plating layer, and composite plating layer, the surface of the material is imparted with water repellency, oil repellency, electrical characteristics, high slidability, etc., which are unique to the above fluororesin particles. The invention is not particularly limited as long as the effects of the invention can be exhibited. For example, computer-related parts such as various terminal boards, printed boards, semiconductors, liquid crystals, organic EL, antennas, film materials for electric and electronic parts such as film capacitors, etc. In addition to being suitable for electrical and electronic parts applications such as, generators, motors, transformers, current transformers, voltage regulators, rectifiers, inverters, relays, power contacts, switches, circuit breakers, switch boards , Other pole rod, electrical equipment parts such as electrical parts cabinet, VTR parts, TV parts, audio parts, audio / video equipment parts such as DVD, lighting parts, Home and office electrical product parts typified by electronic equipment cases such as computers; office computer-related parts, mobile phone-related parts, facsimile-related parts, copier-related parts, and other machine-related parts: microscopes, cameras, etc. It is suitably used for representative optical equipment, precision machine-related parts; aircraft parts, train car parts, automobile parts and the like.

  As a coating method, the coating liquid using the fluororesin aqueous dispersion having the above-described configuration is knife coating method, cast coating method, roll coating method, gravure coating method, blade coating method, rod coating method, air doctor coating method, curtain Coating methods, fakunlan coating methods, kiss coating methods, screen coating methods, spin coating methods, spray coating methods, extrusion coating methods, electrodeposition coating methods, etc. can be used. A coating layer suitable for the surface of the material can be formed by using a roll coating method, a gravure coating method, a cast coating method or the like from the point that the thickness variation is small and the productivity is excellent.

In the present invention, the coating layer preferably has a volume average particle diameter Dv of the fluorinated resin particles after dispersion and a fluorinated resin particle, from the viewpoint of sufficiently exhibiting the inherent properties of the fluorinated resin particles. It is preferable that the thickness T1 of the coating layer to be contained is adjusted in a range satisfying the following formula (I).
0.5T1 ≦ Dv ≦ 4T1 (I)
For example, when the volume average particle diameter Dv is 10 μm, the thickness T1 of the coating layer is preferably 5 μm to 40 μm. When Dv is less than half of T1, the fluororesin particles are less likely to be exposed on the surface of the coating, and thus the function of the fluororesin particles tends not to be effectively expressed. Moreover, when Dv exceeds 4 times of T1, it will be easy to drop | omit from a coating layer, it will become difficult to hold | maintain, and it will become difficult to express the function of a fluorine resin particle effectively. In addition, dropping off from the coating layer can be suppressed by using more irregular particles. Outside of the above range (outside the range of the above formula (I), T1 when the Dv is 10 μm is outside the range of 5 μm to 40 μm), the effect of the present invention can be exhibited more than the case where no coating layer is formed. Within the range of I), the effect of the present invention can be exhibited to a high degree.

The plating method (single layer, composite plating layer formation method) is not particularly limited, and an electroless plating method by preparing a plating solution and a composite plating solution using the fluororesin aqueous dispersion having the above-described configuration, Any method such as an electrolytic plating method, a hot dipping method, a vapor deposition plating method, a dispersion plating method, and a vacuum plating method may be used.
The metal for plating is not particularly limited as long as it can be used for plating. The metal for plating is selected from copper, gold, silver, nickel, platinum, molybdenum, ruthenium, aluminum, tungsten, iron, titanium, chromium, or an alloy containing at least one of these metal elements. Can do. For example, in a printed circuit board or the like, a method may be adopted in which a plating resist having a pattern opposite to the conductor layer (wiring pattern) is formed first, and then the conductor layer (wiring pattern) is formed only by electroless plating. it can.
The composite plating method may be the above electroplating method or electroless plating method. For example, a copper-nickel composite plating layer, a copper-cobalt plating layer, or a nickel plating layer may be formed.

In the present invention, the plating layer (single layer, composite plating layer) is preferably a volume average particle diameter of the fluorinated resin particles after dispersion from the viewpoint of sufficiently exhibiting the inherent properties of the fluorinated resin particles. It is preferable that Dv and the thickness T2 of the plating layer containing the fluorine-based resin particles (the surface side layer in the case of a composite) are adjusted in a range satisfying the following formula (II).
0.5T2 ≦ Dv ≦ 4T2 (II)
For example, when the volume average particle diameter Dv is 5 μm, the thickness T2 of the plating layer is preferably 2.5 μm to 20 μm. If Dv is less than half of T2, the fluororesin particles are less likely to be exposed on the surface of the plating layer, and thus the function of the fluororesin particles tends to be difficult to be expressed effectively. Moreover, when Dv exceeds 4 times T2, it will become easy to drop | omit from a plating layer, it will become difficult to hold | maintain, and it will become difficult to express the function of a fluorine resin particle effectively. In addition, dropping off from the plating layer can be suppressed by using more irregular particles. Outside of the above range (outside the range of the above formula (II), T2 when Dv is 5 μm is outside the range of 2.5 μm to 20 μm), the effect of the present invention can be exhibited more than the case where no coating layer is formed. The effect of the present invention can be exhibited to a high degree within the range of the formula (II).

  The molded article formed with the coating layer and plating layer of the present invention thus obtained is capable of uniformly dispersing the fluorine-based resin particles in the coating layer on the surface to be the material surface, PTFE particles, PVDF It is possible to obtain a molded product having specific functions such as particles, such as water repellency, oil repellency, electrical properties, high slidability, antifouling properties, heat resistance, flame retardancy, and scratch resistance. In the case of thin molded products, elongated molded products, opportunity parts, electrical / electronic parts, fiber materials and film materials, it has a special effect.

  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 11 and Comparative Examples 1 and 2: Preparation of fluororesin aqueous dispersion]
Fluorine resin water dispersion using a kneader in a conventional manner with the formulation shown in Table 1 below (fluorine resin particles, nonionic surfactant, thickener, pH adjuster, preservative, solvent, water) The body was prepared. Each obtained fluororesin aqueous dispersion was evaluated for volume average particle diameter Dv, viscosity ratio (B / A), redispersibility (1 week, 1 month), and coefficient of static friction (coating, composite plating).

(Measurement method of volume average particle diameter Dv)
The volume average particle diameter Dv is a value measured using a Nikkiso Microtrack MT3000.

About the obtained fluororesin aqueous dispersion, the viscosity ratio (B / A) of volume average particle diameter Dv, 1 rpm (A: 3.83 s ⁻¹ ) and 10 rpm (B: 38.3 s ⁻¹ ) by the following measurement method. ) And the pH concentration was measured.
Moreover, redispersibility (1 week, 1 month) and static friction coefficient (coating, composite plating) were evaluated by the following evaluation methods using the obtained fluororesin aqueous dispersion.
These results are shown in Table 1 below.

[Measurement method of viscosity ratio (B / A)]
Using a cone plate viscometer (RE110R, manufactured by Toki Sangyo Co., Ltd.), the shear rate at 25 ° C. was 3.83 s ⁻¹ (1 rpm: A) and the shear rate was 38.3 s ⁻¹ (10 rpm: B). Each viscosity was measured and the viscosity ratio (B / A) was calculated.

(One week, one month redispersibility evaluation method)
The redispersibility for 1 week was evaluated according to the following evaluation criteria by placing the fluororesin aqueous dispersion in a 30 mL glass bottle, standing at room temperature (25 ° C.) for 1 week, and repeatedly turning upside down. One-month redispersibility was also evaluated in the same manner as described above.
Evaluation criteria:
A: No sedimentation (no upside down)
○: Reversal less than 20 times Δ: 20 times or more and less than 100 times ×: 100 times or more

[Evaluation method of static friction coefficient (coating, composite plating)]
Using the obtained fluororesin aqueous dispersion, a coating liquid was prepared by the following preparation method, and coating was performed on an 80 × 200 mm (t = 1 mm) bakelite plate.
Moreover, using the obtained fluororesin aqueous dispersion, a composite plating solution was prepared by the following preparation method, and a composite plating process was performed on an 80 × 200 mm (t = 1 mm) bakelite plate.
The static friction coefficient of each bakelite plate subjected to the coating and composite plating treatment was measured according to JIS K 7125.
A 63 × 63 mm felt was used as the slip piece, and a load of 1.96 N was applied to the slide piece. The static friction coefficient was calculated from the maximum tensile load when the sliding piece was slid at a test speed of 100 mm / min.

(Preparation of coating solution, coating method)
Fluorine resin aqueous dispersion was added to 70 parts by weight of Adhesive 1 (Johncrill 63J, manufactured by BAFS) at a ratio of 9 parts by weight of fluoric resin particles, and the mixture was stirred well to prepare a coating solution. did.
Next, the bakelite plate was fixed on the applicator, a coating film was formed with a 2 mil blade, and the coating was processed by sufficiently drying on a hot plate heated to 100 ° C.
(Preparation of composite plating solution, plating method)
In ion-exchanged water, nickel sulfate (25 g / L), sodium hypophosphite (20 g / L), and citric acid (30 g / L) are blended, and the fluorine resin particle concentration is 10 g / L. A fluororesin aqueous dispersion was added. If necessary, the pH was adjusted to 8-9 with aqueous ammonia to prepare a composite plating solution.
Next, the bakelite plate pretreated by palladium deposition was subjected to composite plating at 90 ° C. for 24 hours in a well-stirred plating bath.

  As is clear from the results of Table 1 above, Examples 1 to 11 according to the present invention have a preferable viscosity ratio (B / A) as compared with Comparative Examples 1 and 2 that are outside the scope of the present invention. It was confirmed that the film was excellent in redispersibility (1 week, 1 month) and had a low coefficient of static friction (coating, composite plating), so that it was highly slidable.

[Examples 12 to 18 and Comparative Example 3: Formation of Coating Layer]
A coating solution using a fluororesin aqueous dispersion was prepared by a conventional method with the formulation shown in Table 2 below.
The volume average particle diameter Dv of the fluorine resin particles in the coating liquid using the obtained fluorine resin aqueous dispersion was measured.
Moreover, the coating liquid using the obtained fluororesin aqueous dispersion was coated on a bakelite plate of 80 × 200 mm (t = 1 mm) to form a coating layer having a thickness shown in Table 2 below.
The coefficient of static friction of each coated bakelite plate was measured in accordance with JIS K 7125.
A 63 × 63 mm felt was used as the slip piece, and a load of 1.96 N was applied to the slide piece. The static friction coefficient was calculated from the maximum tensile load when the sliding piece was slid at a test speed of 100 mm / min.
These results are shown in Table 2 below.

[Examples 19 to 25 and Comparative Example 4: Formation of Composite Plating Layer]
A composite plating solution using a fluororesin aqueous dispersion was prepared by a conventional method with the formulation shown in Table 3 below. Using a plating solution containing nickel sulfate (25 g / L), sodium hypophosphite (20 g / L), citric acid (30 g / L), and adjusted to pH 8-9 with aqueous ammonia as necessary, The treatment was performed at 90 ° C. for 24 hours in a well-stirred plating bath.
The aqueous dispersion of fluororesin particles was adjusted and blended so that the fluororesin particle concentration was 10 g / L. This was repeated until the desired film thickness was obtained.
The obtained composite plating solution using the fluororesin aqueous dispersion was subjected to a composite plating treatment on an 80 × 200 mm (t = 1 mm) bakelite plate.
The coefficient of static friction of each coated bakelite plate was measured in accordance with JIS K 7125.
A 63 × 63 mm felt was used as the slip piece, and a load of 1.96 N was applied to the slide piece. The static friction coefficient was calculated from the maximum tensile load when the sliding piece was slid at a test speed of 100 mm / min.
These results are shown in Table 3 below.

  As is clear from the results of Table 2 and Table 3 above, the coating layer of Examples 12 to 18 and the composite plating layer of Examples 19 to 25 are within the scope of the present invention, and Comparative Example 3 is outside the scope of the present invention. Compared to 4, it was found that the film thickness was suitable for satisfying the above formulas (I) and (II), so that the static friction coefficient was low and high slidability was achieved.

  Various materials such as terminal boards, printed circuit boards, semiconductors, liquid crystals, organic EL, antennas, film materials for electrical and electronic parts such as film capacitors, etc. It is suitable for use in applications such as coating layers that can impart water repellency, oil repellency, electrical properties, high slidability, etc., which are functions unique to fluororesin particles, and plating layers such as composite plating layers. A fluororesin aqueous dispersion that can be obtained is obtained.

Claims (11)

  A fluorine resin aqueous dispersion comprising 1 to 80% by mass of fluorine resin particles having a volume average particle diameter Dv of 1 μm to 50 μm after dispersion.   2. The fluororesin aqueous dispersion according to claim 1, comprising 0.01 to 5 mass% of a water-soluble thickener. The ratio B / A of the viscosity A at a shear rate of 3.83 s ^{-1 to} the viscosity B at a shear rate of 38.3 s ^-1 of the fluororesin aqueous dispersion is less than 0.7. The fluororesin aqueous dispersion as described.   The fluororesin aqueous dispersion according to any one of claims 1 to 3, comprising 0.3 to 30% by mass of a nonionic surfactant having a weight average molecular weight Mw of less than 100,000.   The fluororesin aqueous dispersion according to any one of claims 1 to 4, comprising an amine as a pH adjuster and having a pH of 8.5 or more.   6. The fluororesin aqueous dispersion according to claim 5, which contains no preservative, antifungal agent or antibacterial agent in an amount of 0.5 mass% or more.   The fluororesin aqueous dispersion according to any one of claims 1 to 6, wherein the fluororesin particles are polytetrafluoroethylene.   A coating layer formed using the fluororesin aqueous dispersion according to any one of claims 1 to 7. The coating layer according to claim 8, wherein the volume average particle diameter Dv of the fluorinated resin particles after dispersion and the thickness T1 of the coating layer containing the fluorinated resin particles are adjusted in a range satisfying the following formula (I).
0.5T1 ≦ Dv ≦ 4T1 (I)   A composite plating layer formed using the fluororesin aqueous dispersion according to any one of claims 1 to 7. The composite plating layer according to claim 10, wherein the volume average particle diameter Dv of the fluorine resin particles after dispersion and the thickness T2 of the composite plating layer containing the fluorine resin particles are adjusted in a range satisfying the following formula (II). .
0.5T2 ≦ Dv ≦ 4T2 (II)