WO2017110188A1 - Aqueous dispersion type electrodeposition liquid for insulating-film formation - Google Patents

Aqueous dispersion type electrodeposition liquid for insulating-film formation Download PDF

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Publication number
WO2017110188A1
WO2017110188A1 PCT/JP2016/078424 JP2016078424W WO2017110188A1 WO 2017110188 A1 WO2017110188 A1 WO 2017110188A1 JP 2016078424 W JP2016078424 W JP 2016078424W WO 2017110188 A1 WO2017110188 A1 WO 2017110188A1
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Prior art keywords
electrodeposition
water
electrodeposition liquid
polymer particles
insulating film
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PCT/JP2016/078424
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French (fr)
Japanese (ja)
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洵子 磯村
慎太郎 飯田
桜井　英章
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三菱マテリアル株式会社
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Priority claimed from JP2016166752A external-priority patent/JP6794718B2/en
Application filed by 三菱マテリアル株式会社 filed Critical 三菱マテリアル株式会社
Priority to EP16878086.4A priority Critical patent/EP3395917B1/en
Priority to KR1020187017392A priority patent/KR102595402B1/en
Priority to US16/064,383 priority patent/US10800942B2/en
Priority to CN201680074952.5A priority patent/CN108473813A/en
Publication of WO2017110188A1 publication Critical patent/WO2017110188A1/en

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
    • C09D5/02—Emulsion paints including aerosols
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D179/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen, with or without oxygen, or carbon only, not provided for in groups C09D161/00 - C09D177/00
    • C09D179/04—Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
    • C09D179/08—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
    • C09D5/44—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes for electrophoretic applications
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
    • C09D7/40—Additives

Definitions

  • the present invention relates to a water-dispersed insulating film forming electrodeposition liquid used when an insulating film provided in an insulator such as an insulated wire is formed by an electrodeposition method.
  • an insulator such as an insulated wire whose surface is covered with an insulating film is used for a motor, a reactor, a transformer, and the like.
  • a method for forming an insulating film on the surface of an electric wire a dipping method, an electrodeposition method (electrodeposition coating), or the like is known.
  • the dipping method is a method of forming an insulating film having a desired film thickness by, for example, using a rectangular conductive wire or the like as an object to be coated, dipping it in a paint, pulling it up, and repeatedly drying it. .
  • the electrodeposition method deposits charged paint particles on the object to be coated by applying a direct current to the object to be coated immersed in the electrodeposition paint (electrodeposition liquid) and the electrode inserted in the electrodeposition paint. This is a method of forming an insulating film.
  • the electrodeposition method is attracting attention because it is easier to apply with a uniform film thickness than other methods, and it can form an insulating film with high rust prevention and adhesion after baking. Improvements have been made.
  • a paint used in the electrodeposition method particles of a block copolymerized polyimide having a siloxane bond in the molecular skeleton and an anionic group in the molecule, and having a predetermined average particle size and particle size distribution
  • a suspension type polyimide electrodeposition coating material in which is dispersed is disclosed (for example, see Patent Document 1).
  • This electrodeposition paint has excellent storage stability that is difficult to change even after long-term storage, and by using this electrodeposition paint, an electrodeposition film with high uniformity of film properties can be formed at a high electrodeposition rate. It is supposed to be possible.
  • an electrodeposition material used for the electrodeposition method an electrodeposition material containing a polyamideimide material as a main component and introducing polydimethylsiloxane into the molecular chain of the polyamideimide material is disclosed (for example, see Patent Document 2.)
  • the polyamideimide-based material having a predetermined molecular structure is used, the heat resistance particularly required for the coating of sliding members and the like can be imparted. It is said that cracking of the film can be suppressed.
  • water-soluble polyamideimide is used for the resin, and a continuous film insoluble in water is formed on the conductor surface during electrodeposition. For this reason, if the formation of the film proceeds to some extent, the subsequent electrodeposition efficiency is deteriorated, and it is difficult to form an insulating film having a desired thickness.
  • the present inventors have developed a new electrodeposition liquid having excellent dispersion stability while using polymer particles having no anionic group in the main chain so far. Is engaged in. Polymer particles that do not have an anionic group have no surface property because they do not have an anionic group, and the electrostatic repulsive force between particles becomes small, so the dispersibility in the electrodeposition liquid deteriorates and the particles aggregate. Or, there is a concern that it will easily settle.
  • the newly developed electrodeposition liquid ensures good dispersibility of the polymer particles in the electrodeposition liquid by controlling the average particle size and particle size distribution of the polymer particles under predetermined conditions. Thus, even when stored for several days, the occurrence of aggregation or sedimentation of polymer particles is suppressed.
  • An object of the present invention is a water-dispersed insulating film that is excellent in storage stability, can suppress an increase in the viscosity of an electrodeposition solution even after long-term storage, and can suppress foaming during drying or baking of the coating film It is to provide a forming electrodeposition liquid.
  • the polymer particles are polyamideimide, and the basic compound is water. It is a nitrogen-containing compound having an HSP distance of 35 or more.
  • the second aspect of the present invention is an invention based on the first aspect, wherein the basic compound is an alkylamine compound.
  • the electrodeposition liquid for forming a water-dispersed insulating film according to the first aspect of the present invention contains polymer particles, an organic solvent, a basic compound and water, the polymer particles are polyamideimide, and the basic compound is water and Is a nitrogen-containing compound having an HSP distance of 35 or more.
  • the electrodeposition liquid for forming a water-dispersed insulating film according to the second aspect of the present invention can further enhance the effect of improving the storage stability of the electrodeposition liquid because the basic compound is an alkylamine compound.
  • This electrodeposition liquid for forming a water dispersion type insulating film contains polymer particles, an organic solvent, a basic compound and water. A poor solvent may be contained in addition to water.
  • the polymer particles contained in the electrodeposition liquid are composed of polyamideimide which is a polymer (polymer).
  • the reason why particles made of polyamideimide are used as polymer particles is that heat resistance and flexibility are superior to other polymer particles.
  • the average particle diameter of the polymer particles is not particularly limited from the viewpoint of suppressing foaming during drying or firing, and those having a particle diameter used for general electrodeposition liquid applications can be used.
  • polymer particles having an average particle diameter of preferably 0.05 to 1.0 ⁇ m can be used.
  • the average particle diameter of the polymer particles referred to here is a volume-based median diameter (D 50 ) measured by a dynamic light scattering type particle size distribution analyzer (model name: LB-550, manufactured by Horiba, Ltd.).
  • the polyamideimide which comprises a polymer particle, the polyamideimide etc. which are used for the general electrodeposition liquid use can be utilized as resin which comprises the said polymer particle.
  • it may be a polyamideimide having an anionic group in the main chain, or a polyamideimide having no anionic group in the main chain.
  • the anionic group as such -COOH group (carboxyl group) or -SO 3 H (sulfonic acid group), in a basic solution such as proton is eliminated -COO - nature take on negative charge of such group
  • the polyamideimide constituting the polymer particle has an anionic group in the main chain in order to suppress aggregation or sedimentation of the polymer particle.
  • the polyamideimide particularly has an anionic group. It is not limited to things.
  • polyamideimide having an anionic group in the main chain needs to use a monomer having an anionic group as a monomer used for the synthesis, and the usable monomer is limited, so that the production cost increases. There is. For this reason, in order to reduce the cost, it is desirable to use polymer particles composed of polyamideimide having no anionic group in the main chain.
  • polymer particles composed of polyamideimide having no anionic group in the main chain exhibit a relatively small surface potential. Therefore, dispersibility due to electrostatic repulsion between particles may not be sufficiently obtained, but dispersibility can be enhanced by controlling the particle size, particle size distribution, and the like. For this reason, in addition to suppressing foaming, it is desirable to more strictly control the particle size and particle size distribution of polymer particles in consideration of dispersibility when further reducing costs and suppressing aggregation or sedimentation.
  • the volume-based median diameter (D 50 ) is 0.05 to 0.5 ⁇ m, and the particle diameter is ⁇ of the median diameter (D 50 ).
  • the particles within 30% are preferably 50% (volume basis) or more of all particles. That is, the polymer particles have a median diameter (D 50 ) in the range of 0.05 to 0.5 ⁇ m when the volume-based particle size distribution of the powder comprising the particles is measured, Particles of 50% or more of the number of particles are distributed within a range of ⁇ 30% of the median diameter (D 50 ) (within a range of [D 50 -0.3D 50 ] ⁇ m to [D 50 + 0.3D 50 ] ⁇ m). To do.
  • D 50 median diameter
  • the volume-based median diameter (D 50 ) and the proportion of particles distributed within a range of ⁇ 30% of the median diameter (D 50 ) (volume basis) are both dynamic light scattering particle size distribution measuring devices ( This is based on the volume-based particle size distribution measured by HORIBA, Ltd. (model name: LB-550).
  • the polyamideimide having no anionic group in the main chain means a polyamideimide having no anionic group at least on carbon atoms other than the end of the main chain.
  • the reason why the volume-based median diameter (D 50 ) of the polymer particles having no anionic group in the main chain is preferably in the above range is that if this volume-based median diameter (D 50 ) is too small, it will be described later.
  • the polymer particles may form a continuous film during electrodeposition when forming the insulating layer, and the electrodeposition efficiency gradually decreases, making it difficult to increase the thickness of the insulating layer.
  • the volume-based median diameter (D 50 ) even if the formation of the insulating layer proceeds to some extent by electrodeposition, the subsequent current flow can be easily maintained. The reason is that conductive water contained in the solvent tends to exist between the polymer particles. On the other hand, if the volume-based median diameter (D 50 ) becomes too large, precipitation may occur in the electrodeposition solution stored for several days.
  • the reason why the proportion of particles distributed within a range of ⁇ 30% of the volume-based median diameter (D 50 ) is preferably 50% or more is that even if the proportion of the particles is too small, it is stored for several days. This is because precipitation may occur in the deposited electrodeposition solution.
  • polymer particles having no anionic group have a volume-based median diameter (D 50 ) of 0.08 to 0.25 ⁇ m and are distributed within a range of ⁇ 30% of the median diameter (D 50 ).
  • the proportion of particles is more preferably 75% or more.
  • Polyamideimide constituting polymer particles is a reaction product (resin) obtained by polymerizing a diisocyanate component containing an aromatic diisocyanate component and an acid component containing trimellitic anhydride, etc., as monomers. It is.
  • diisocyanate component examples include diphenylmethane-4,4′-diisocyanate (MDI), diphenylmethane-3,3′-diisocyanate, diphenylmethane-3,4′-diisocyanate, diphenylether-4,4′-diisocyanate, and benzophenone-4,4 ′.
  • aromatic diisocyanates such as diisocyanate and diphenylsulfone-4,4′-diisocyanate.
  • the acid component includes trimellitic anhydride (TMA), 1,2,5-trimellitic acid (1,2,5-ETM), biphenyltetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride , Diphenylsulfonetetracarboxylic dianhydride, oxydiphthalic dianhydride (OPDA), pyromellitic dianhydride (PMDA), 4,4 '-(2,2'-hexafluoroisopropylidene) diphthalic dianhydride
  • TMA trimellitic anhydride
  • 1,2,5-ETM 1,2,5-trimellitic acid
  • biphenyltetracarboxylic dianhydride benzophenonetetracarboxylic dianhydride
  • Diphenylsulfonetetracarboxylic dianhydride oxydiphthalic dianhydride (OPDA), pyromellitic dianhydride (PMDA), 4,4 '
  • the polyamide-imide resin varnish can be obtained by mixing the diisocyanate component and the acid component in equal amounts and heating in an organic solvent to cause a polymerization reaction.
  • the said isocyanate component and an acid component may each be used individually, and may be used combining several types.
  • the polyamideimide constituting the polymer particles does not have a siloxane bond. This is because if the siloxane bond is present, the siloxane bond is likely to be thermally decomposed, so that the heat resistance of the insulating film may be deteriorated. Since the presence or absence of a siloxane bond results from the use of a monomer containing a siloxane bond, a polymer having no siloxane bond can be obtained by using a monomer that does not contain a siloxane bond.
  • Organic solvents include 1,3-dimethyl-2-imidazolidinone (DMI), N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, tetramethylurea, hexa Polar solvents such as ethyl phosphoric acid triamide and ⁇ -butyrolactam can be used.
  • DMI 1,3-dimethyl-2-imidazolidinone
  • N-methyl-2-pyrrolidone N, N-dimethylformamide
  • N, N-dimethylacetamide dimethyl sulfoxide
  • tetramethylurea hexa Polar solvents
  • water include pure water, ultrapure water, and ion exchange water.
  • examples of the poor solvent include aliphatic alcohols such as 1-propanol and isopropyl alcohol, ethylene glycols such as 2-methoxyethanol, 1-methoxy-2-propanol, and the like. Propylene glycols or the like can be used.
  • the basic compound is a component added to the electrodeposition liquid as a neutralizing agent or a dispersing agent, and a nitrogen-containing compound having an HSP distance of 35 or more with water is used as the basic compound.
  • HSP Hanesen Solubility Parameter
  • This HSP value is composed of three parameters of a dispersion term (dD), a polarity term (dP), and a hydrogen bond term (dH), and shows a unique value for each substance.
  • the HSP value is represented as a vector having 0 in the space as the start point and the coordinate given by the HSP value as the end point.
  • the HSP distance (Ra) is a distance between the coordinates or a vector distance given by the HSP values of two substances, and is generally calculated by the following equation (1).
  • HSP distance [4 ⁇ (dD 1 ⁇ dD 2 ) 2 + (dP 1 ⁇ dP 2 ) 2 + (dH 1 ⁇ dH 2 ) 2 ] 1/2 (1)
  • dD 1 , dP 1 and dH 1 are HSP values of one of the two substances
  • dD 2 , dP 2 and dH 2 are HSP values of the other substance. It shows that the compatibility between the two substances is higher as the substances having a smaller HSP distance calculated by the equation (1).
  • the storage stability of the electrodeposition liquid can be improved by using, as the basic compound contained in the electrodeposition liquid, a nitrogen-containing compound having an HSP distance with water of a predetermined value or more. Thereby, even if the electrodeposition liquid after preparation is preserve
  • the technical reason that the storage stability of the electrodeposition solution is improved by using a nitrogen-containing compound having such physical property values has not been elucidated at present, but the following technical reasons are the main technical reasons. Inferred as The basic compound functions to enhance the dispersibility of the electrodeposition liquid by binding in the polymer structure.
  • the basic compound is hydrophilic, such as 2-aminoethanol
  • the water in the electrodeposition solution tends to approach the polymer particles, so that the polyamideimide is easily hydrolyzed.
  • polar groups such as carboxyl groups and amino groups are generated, so the viscosity of the liquid rises by attracting polar solvents such as DMI and water, and the polymer takes in the solvent and partially gels.
  • polar solvents such as DMI and water
  • the polymer takes in the solvent and partially gels.
  • the upper limit is not particularly limited as long as the HSP distance to water reaches at least 35, but the HSP distance to water is 35 to 45 from the relationship with the HSP value of the nitrogen-containing compound that can be confirmed at present. Are preferred.
  • nitrogen-containing compounds which exhibit such physical property values and are suitable as basic compounds contained in the electrodeposition liquid include alkylamine compounds.
  • alkylamine compounds include primary alkylamines such as propylamine, butylamine, amylamine, hexylamine, octylamine and decylamine, and second alkylamines such as dipropylamine, dibutylamine, diamylamine, dihexylamine and dioctylamine.
  • Tertiary alkylamines such as tertiary alkylamine, tripropylamine, tributylamine, triamylamine, and trihexylamine are listed. Of these, tripropylamine, tributylamine, triamylamine, trihexylamine, and the like are particularly preferable because of their large HSP distance with water and high hydrophobicity.
  • the electrodeposition liquid can be obtained, for example, by the following method.
  • a polyamideimide resin varnish is synthesized using a diisocyanate component, an acid component, and an organic solvent as described above.
  • the diisocyanate component and the acid component as monomers are respectively prepared, and together with these, an organic solvent such as DMI is introduced into the flask at a predetermined ratio.
  • the flask is preferably a four-necked flask equipped with a stirrer, a cooling pipe, a nitrogen introduction pipe, a thermometer, and the like.
  • the mixing ratio of the diisocyanate component and the acid component is preferably set to a ratio of 1: 1 as a molar ratio.
  • the proportion of the organic solvent is preferably a proportion corresponding to 1 to 3 times the mass of the resin obtained after synthesis.
  • the temperature is preferably raised to a temperature of 80 to 180 ° C., and the reaction is preferably carried out for 2 to 8 hours.
  • the prepared polyamideimide resin varnish is further diluted with the organic solvent as necessary,
  • the above-mentioned basic compound is added as a dispersant or neutralizer.
  • a poor solvent may be added as necessary.
  • water is added and dispersed sufficiently at room temperature.
  • the above-mentioned electrodeposition liquid for forming a water-dispersed insulating film is obtained.
  • the electrodeposition coating apparatus 10 is used to electrodeposit the electrodeposition liquid 11 on the surface of the electric wire 12 by an electrodeposition coating method to form an insulating layer 21a.
  • a cylindrical electric wire 13 having a circular cross section that is wound in a cylindrical shape is electrically connected in advance to the positive electrode of the DC power source 14 via the anode 16. And this cylindrical electric wire 13 is pulled up in the direction of the solid line arrow of FIG. 1, and passes through each next process.
  • a cylindrical electric wire 13 is rolled flat by a pair of rolling rollers 17 and 17 to form a rectangular electric wire 12 having a rectangular cross section.
  • the electric wire include a copper wire, an aluminum wire, a steel wire, a copper alloy wire, and an aluminum alloy wire.
  • the electrodeposition liquid 11 is stored in the electrodeposition tank 18 and is preferably maintained at a temperature of 5 to 60 ° C. so that the electrodeposition liquid 11 in the electrodeposition tank 18 has a rectangular shape.
  • the electric wire 12 is passed.
  • a cathode 19 that is electrically connected to the negative electrode of the DC power supply 14 is inserted into the electrodeposition liquid 11 in the electrodeposition tank 18 with a space from the flat rectangular wire 12 passing therethrough.
  • a DC voltage is applied between the rectangular electric wire 12 and the cathode 19 by the DC power source 14.
  • the DC voltage of the DC power supply 14 is preferably 1 to 300 V, and the DC current application time is preferably 0.01 to 30 seconds.
  • negatively charged polymer particles (not shown) are electrodeposited on the surface of the flat wire 12 to form the insulating layer 21 a.
  • an insulating film 21b is formed on the surface of the electric wire 12 by subjecting the flat electric wire 12 having the insulating layer 21a electrodeposited on the surface thereof to a baking treatment.
  • the electric wire 12 having the insulating layer 21a formed on the surface thereof is baked by passing through the baking furnace 22.
  • the baking treatment is preferably performed by a near infrared heating furnace, a hot air heating furnace, an induction heating furnace, a far infrared heating furnace, or the like.
  • the temperature of the baking treatment is preferably in the range of 250 to 500 ° C., and the time of the baking treatment is preferably in the range of 1 to 10 minutes. Note that the temperature of the baking treatment is the temperature of the central portion in the baking furnace.
  • Example 1 In a 2 liter four-necked flask equipped with a stirrer, a condenser, a nitrogen inlet tube and a thermometer, 30.97 g of 1,3-dimethyl-2-imidazolidinone (DMI), diphenylmethane-4,4′-diisocyanate 508 g (30 mmol) and trimellitic anhydride 5.764 g (30 mmol) were charged, and the temperature was raised to 160 ° C.
  • DMI 1,3-dimethyl-2-imidazolidinone
  • diphenylmethane-4,4′-diisocyanate 508 g 30 mmol
  • trimellitic anhydride 5.764 g 30 mmol
  • Examples 2 to 7 and Comparative Example 1 As shown in Table 1 below, the electrodeposition solution was prepared in the same manner as in Example 1 except that the average particle diameter of the polymer particles, the type of the basic compound, and the ratio of each component in the electrodeposition solution were changed. Obtained.
  • the average particle diameter of the polymer particles is a numerical value obtained by changing the ratio of other liquid components, and is a volume-based median diameter (D 50 ) described later.
  • HSP distance from flooded water By substituting the HSP value of water and the HSP value of the nitrogen-containing compound used as the basic compound in each Example or Comparative Example, into the following formula (1), The HSP distance of the contained compound and water was calculated respectively.
  • HSP value of the nitrogen-containing compound an HSP value obtained by software capable of calculating the HSP value from the structural formula of the substance (software name: Hansen Solubility Parameter in Practice (HSPIP)) was used.
  • HSP distance [4 ⁇ (dD 1 ⁇ dD 2 ) 2 + (dP 1 ⁇ dP 2 ) 2 + (dH 1 ⁇ dH 2 ) 2 ] 1/2 (1)
  • volume-based median diameter (D 50 ) measured with a dynamic light scattering particle size distribution analyzer (model name: LB-550, manufactured by Horiba, Ltd.) for the polymer particles synthesized in each Example or Comparative Example The volume-based median diameter (D 50 ) was measured.
  • the insulator was manufactured according to the procedure described later.
  • three insulators having an insulating film thickness of 10 ⁇ m, 20 ⁇ m, and 30 ⁇ m, respectively, were prepared.
  • the electrodeposition liquid immediately after the preparation refers to an electrodeposition liquid before 24 hours have passed after the preparation, and the electrodeposition liquid stored for one month after the adjustment means that the adjusted electrodeposition liquid is sealed in a glass bottle.
  • the electrodeposition liquid stored in the atmosphere at a temperature of 25 ° C. for 1 month.
  • the film thickness is a value measured using a micrometer (Mitutoyo Co., Ltd. model name: MDH-25M) after forming an insulating film on the surface of the copper plate.
  • Each insulator was produced by the following procedure. First, the electrodeposition liquid was stored in the electrodeposition tank, and the temperature of the electrodeposition liquid in the electrodeposition tank was adjusted to 25 ° C. Next, an 18 mm square (thickness: 0.3 mm) copper plate and stainless steel plate were prepared as an anode and a cathode, respectively, and these were placed facing each other in the electrodeposition solution. And the DC voltage 100V was applied between the copper plate and the stainless steel plate, and electrodeposition was performed. At that time, the amount of electricity flowing by the coulomb meter was confirmed, and the application of voltage was stopped when the amount of electricity reached a predetermined amount.
  • an insulating film having a film thickness of 10 ⁇ m When an insulating film having a film thickness of 10 ⁇ m is formed, the application of voltage is stopped when the amount of electricity reaches 0.05 C, and when an insulating film having a film thickness of 20 ⁇ m is formed, the amount of electricity is 0.1. When the voltage reached 10 C, the application of voltage was stopped. When an insulating film having a film thickness of 30 ⁇ m was formed, the voltage application was stopped when the amount of electricity reached 0.15 C. Thereby, an insulating layer was formed on the surface of the copper plate.
  • the copper plate having an insulating layer formed on the surface was baked. Specifically, the copper plate on which the insulating layer was formed was held for 3 minutes in a baking furnace maintained at a temperature of 250 ° C. Thereby, an insulator having an insulating film formed on the surface of the copper plate was obtained.
  • the temperature in a baking furnace is the temperature of the center part in a furnace measured with the thermocouple.
  • Examples 1 to 7 using a nitrogen-containing compound whose HSP distance with water is a predetermined value or more as a basic compound bubbles are formed in the insulating film having a thickness of 30 ⁇ m in Examples 2 and 4 to 6. No air bubbles due to foaming at the time of drying or baking were observed in any of the insulating films except that a slight amount of was observed. From this, it was confirmed that the electrodeposition liquids of Examples 1 to 7 using a nitrogen-containing compound having an HSP distance with water as a basic compound of a predetermined value or more are very excellent in storage stability. In particular, in Examples 1 and 7, the HSP distance with water as a basic compound is as large as 43.0 and 42.5, respectively. Therefore, even when the film thickness is 30 ⁇ m, bubbles due to foaming during drying or baking are observed. There wasn't.
  • the present invention can be used for the production of insulated wires used in transformers, reactors, motors, etc. for in-vehicle inverters, as well as power inductors for power supplies of personal computers, smartphones, etc., and other insulators.

Abstract

This aqueous dispersion type electrodeposition liquid for insulating-film formation comprises polymer particles, an organic solvent, a basic compound, and water, and is characterized in that the polymer particles are a polyamide-imide and that the basic compound is a nitrogenous compound having an HSP distance of 35 or greater with respect to water .

Description

水分散型絶縁皮膜形成用電着液Electrodeposition solution for water-dispersed insulation film formation
　本発明は、絶縁電線等の絶縁物が備える絶縁皮膜を、電着法により形成する際に用いられる水分散型絶縁皮膜形成用電着液に関する。
　本願は、２０１５年１２月２２日に日本に出願された特願２０１５－２４９７３９号、および２０１６年８月２９日に日本に出願された特願２０１６－１６６７５２号に基づき優先権を主張し、その内容をここに援用する。 The present invention relates to a water-dispersed insulating film forming electrodeposition liquid used when an insulating film provided in an insulator such as an insulated wire is formed by an electrodeposition method.
This application claims priority based on Japanese Patent Application No. 2015-249739 filed in Japan on December 22, 2015 and Japanese Patent Application No. 2016-166752 filed in Japan on August 29, 2016. The contents are incorporated herein.
　従来から、モーター、リアクトル、トランス等には、電線の表面が絶縁皮膜により被覆された絶縁電線等の絶縁物が用いられている。電線の表面に絶縁皮膜を形成する方法としては、浸漬法や電着法（電着塗装）等が知られている。浸漬法は、例えば被塗装体として平角状の導線等を用い、これを塗料に浸漬して引き上げた後、乾燥させる工程を繰り返し行って、所望の膜厚を有する絶縁皮膜を形成する方法である。一方、電着法は、電着塗料（電着液）に浸漬させた被塗装体と電着塗料に挿入した電極に直流電流を流すことで電気を帯びた塗料粒子を被塗装体側に析出させて絶縁皮膜を形成する方法である。 Conventionally, an insulator such as an insulated wire whose surface is covered with an insulating film is used for a motor, a reactor, a transformer, and the like. As a method for forming an insulating film on the surface of an electric wire, a dipping method, an electrodeposition method (electrodeposition coating), or the like is known. The dipping method is a method of forming an insulating film having a desired film thickness by, for example, using a rectangular conductive wire or the like as an object to be coated, dipping it in a paint, pulling it up, and repeatedly drying it. . On the other hand, the electrodeposition method deposits charged paint particles on the object to be coated by applying a direct current to the object to be coated immersed in the electrodeposition paint (electrodeposition liquid) and the electrode inserted in the electrodeposition paint. This is a method of forming an insulating film.
　電着法は、他の方法よりも、均一な膜厚で塗装するのが容易であり、また、焼き付け後に高い防錆力や密着性を持つ絶縁皮膜を形成できることから注目されており、様々な改良がなされている。例えば、電着法に用いられる塗料として、分子骨格中にシロキサン結合を有し、分子中にアニオン性基を有するブロック共重合ポリイミドの粒子であって、所定の平均粒径及び粒度分布を有する粒子を分散させたサスペンジョン型ポリイミド電着塗料が開示されている（例えば、特許文献１参照。）。この電着塗料は長期保存しても変質しにくい優れた保存安定性を有するとともに、この電着塗料を用いることにより高い電着速度で、膜性状の均一性が高い電着皮膜を形成することができるとされている。 The electrodeposition method is attracting attention because it is easier to apply with a uniform film thickness than other methods, and it can form an insulating film with high rust prevention and adhesion after baking. Improvements have been made. For example, as a paint used in the electrodeposition method, particles of a block copolymerized polyimide having a siloxane bond in the molecular skeleton and an anionic group in the molecule, and having a predetermined average particle size and particle size distribution A suspension type polyimide electrodeposition coating material in which is dispersed is disclosed (for example, see Patent Document 1). This electrodeposition paint has excellent storage stability that is difficult to change even after long-term storage, and by using this electrodeposition paint, an electrodeposition film with high uniformity of film properties can be formed at a high electrodeposition rate. It is supposed to be possible.
　また、電着法に用いられる電着材料として、ポリアミドイミド系材料を主成分として含有し、このポリアミドイミド系材料の分子鎖にポリジメチルシロキサンを導入してなる電着材料が開示されている（例えば、特許文献２参照。）。この電着材料によれば、所定の分子構造を有するポリアミドイミド系材料を使用しているので、特に、摺動部材等の塗装に求められる耐熱性を付与することができ、また、電着塗膜のひび割れ等を抑制できるとされている。 In addition, as an electrodeposition material used for the electrodeposition method, an electrodeposition material containing a polyamideimide material as a main component and introducing polydimethylsiloxane into the molecular chain of the polyamideimide material is disclosed ( For example, see Patent Document 2.) According to this electrodeposition material, since the polyamideimide-based material having a predetermined molecular structure is used, the heat resistance particularly required for the coating of sliding members and the like can be imparted. It is said that cracking of the film can be suppressed.
　上記従来の特許文献１では、分子中にアニオン性基を有するポリイミド粒子を使用しているため、粒子の表面電位が大きく、粒子同士の静電反発力によって分散性が高くなる。そのため、調製後の電着液を数日保管しても粒子の凝集又は沈降の発生が抑制される。しかし、カルボキシル基若しくはスルホン酸基を有するジアミンを用いるか、或いはイミド結合に寄与しないカルボキシル基若しくはスルホン酸基を有するテトラカルボン酸無水物を用いる必要があることから、使用できるモノマーの種類が制限されてしまい、製造コストが高くなる。また、上記従来の特許文献２では、樹脂に水溶性ポリアミドイミドを使用しており、電着中に水に不溶性の連続膜が導体表面に形成される。このため、皮膜の形成がある程度進行すると、その後の電着効率が悪くなり、所望の厚さを有する絶縁皮膜の形成が困難になる等の問題があった。 In the above-mentioned conventional patent document 1, since the polyimide particles having an anionic group in the molecule are used, the surface potential of the particles is large, and the dispersibility is increased by the electrostatic repulsive force between the particles. Therefore, even if the prepared electrodeposition liquid is stored for several days, the occurrence of particle aggregation or sedimentation is suppressed. However, since it is necessary to use a diamine having a carboxyl group or a sulfonic acid group, or a tetracarboxylic acid anhydride having a carboxyl group or a sulfonic acid group that does not contribute to an imide bond, the types of monomers that can be used are limited. As a result, the manufacturing cost increases. Moreover, in the above-mentioned conventional patent document 2, water-soluble polyamideimide is used for the resin, and a continuous film insoluble in water is formed on the conductor surface during electrodeposition. For this reason, if the formation of the film proceeds to some extent, the subsequent electrodeposition efficiency is deteriorated, and it is difficult to form an insulating film having a desired thickness.
　このような従来技術が抱える問題について、本発明者らは、これまでに主鎖中にアニオン性基を持たないポリマー粒子を使用しつつも、分散安定性に優れた新たな電着液の開発に従事している。アニオン性基を持たないポリマー粒子は、アニオン性基を持たないがために表面電位が小さく、粒子同士の静電反発力が小さくなるため、電着液中における分散性が悪化し、粒子が凝集又は沈降しやすくなることが懸念される。このような問題について、新たに開発された電着液では、ポリマー粒子の平均粒径や粒度分布を所定の条件で制御することより、電着液中におけるポリマー粒子の良好な分散性が確保され、これによって数日保管してもポリマー粒子の凝集又は沈降の発生が抑制される。 Regarding the problems of such conventional techniques, the present inventors have developed a new electrodeposition liquid having excellent dispersion stability while using polymer particles having no anionic group in the main chain so far. Is engaged in. Polymer particles that do not have an anionic group have no surface property because they do not have an anionic group, and the electrostatic repulsive force between particles becomes small, so the dispersibility in the electrodeposition liquid deteriorates and the particles aggregate. Or, there is a concern that it will easily settle. With respect to such problems, the newly developed electrodeposition liquid ensures good dispersibility of the polymer particles in the electrodeposition liquid by controlling the average particle size and particle size distribution of the polymer particles under predetermined conditions. Thus, even when stored for several days, the occurrence of aggregation or sedimentation of polymer particles is suppressed.
特許第５５５５０６３号公報Japanese Patent No. 5555063 特開２００２－２０８９３号公報JP 2002-20893 A
　一方、上記電着液を開発するにあたり、電着液の保存安定性に関して、上述のポリマー粒子の凝集又は沈降の問題とは別の新たな問題が浮上していた。例えば、数日保管した電着液を用い、比較的厚みのある絶縁皮膜を形成するために電着液の塗布量を増加させると、保管中に電着液の粘度が増加すること等に起因して、塗膜の乾燥又は焼成時に発泡が生じやすくなることが分かった。このため、保管後の電着液を用いて所望の厚さの絶縁皮膜を形成するのが困難になるという問題が生じていた。そこで、こうした保存安定性に関する新たな問題点を克服できる電着液の早期開発が求められていた。 On the other hand, in developing the above electrodeposition solution, a new problem emerged regarding the storage stability of the electrodeposition solution, which is different from the above-mentioned problem of aggregation or sedimentation of polymer particles. For example, if the electrodeposition liquid stored for several days is used and the coating amount of the electrodeposition liquid is increased to form a relatively thick insulating film, the viscosity of the electrodeposition liquid increases during storage. Thus, it was found that foaming is likely to occur during drying or baking of the coating film. For this reason, there has been a problem that it becomes difficult to form an insulating film having a desired thickness using the electrodeposition liquid after storage. Therefore, there has been a demand for early development of an electrodeposition solution that can overcome such new problems relating to storage stability.
　本発明の目的は、保存安定性に優れ、長期保存しても電着液の粘度上昇等が抑えられ、塗膜の乾燥又は焼成時に発泡が生じるのを抑制することができる水分散型絶縁皮膜形成用電着液を提供することにある。 An object of the present invention is a water-dispersed insulating film that is excellent in storage stability, can suppress an increase in the viscosity of an electrodeposition solution even after long-term storage, and can suppress foaming during drying or baking of the coating film It is to provide a forming electrodeposition liquid.
　本発明者らは、上述の保存安定性に関する新たな問題点について、更に鋭意研究を重ねた結果、電着液中に通常含まれる、特にポリマー粒子以外の他の成分に特定の性質を有する化合物を選択的に使用することによって、これらを解決できる電着液の開発に至った。 As a result of further earnest studies on the above-mentioned new problems relating to storage stability, the present inventors have found that compounds that are usually contained in the electrodeposition liquid and that have specific properties particularly in other components than the polymer particles As a result, the electrodeposition solution that can solve these problems has been developed.
　本発明の第１の観点は、ポリマー粒子、有機溶媒、塩基性化合物及び水を含有する水分散型絶縁皮膜形成用電着液において、ポリマー粒子がポリアミドイミドであり、塩基性化合物が水とのＨＳＰ距離が３５以上の窒素含有化合物であることを特徴とする。 According to a first aspect of the present invention, in the electrodeposition liquid for forming a water-dispersed insulating film containing polymer particles, an organic solvent, a basic compound and water, the polymer particles are polyamideimide, and the basic compound is water. It is a nitrogen-containing compound having an HSP distance of 35 or more.
　本発明の第２の観点は、第１の観点に基づく発明であって、更に塩基性化合物はアルキルアミン化合物であることを特徴とする。 The second aspect of the present invention is an invention based on the first aspect, wherein the basic compound is an alkylamine compound.
　本発明の第１の観点の水分散型絶縁皮膜形成用電着液は、ポリマー粒子、有機溶媒、塩基性化合物及び水を含有し、ポリマー粒子がポリアミドイミドであって、塩基性化合物が水とのＨＳＰ距離が３５以上の窒素含有化合物である。これにより、電着液の保存安定性が向上し、長期保存しても電着液の粘度上昇等が抑えられ、塗膜の乾燥又は焼成時に発泡が生じるのを抑制することができる。 The electrodeposition liquid for forming a water-dispersed insulating film according to the first aspect of the present invention contains polymer particles, an organic solvent, a basic compound and water, the polymer particles are polyamideimide, and the basic compound is water and Is a nitrogen-containing compound having an HSP distance of 35 or more. Thereby, the storage stability of the electrodeposition liquid is improved, the increase in the viscosity of the electrodeposition liquid is suppressed even when stored for a long time, and foaming can be suppressed from occurring during drying or baking of the coating film.
　本発明の第２の観点の水分散型絶縁皮膜形成用電着液は、塩基性化合物がアルキルアミン化合物であることにより、上述の電着液の保存安定性を向上させる効果をより高められる。 The electrodeposition liquid for forming a water-dispersed insulating film according to the second aspect of the present invention can further enhance the effect of improving the storage stability of the electrodeposition liquid because the basic compound is an alkylamine compound.
本発明の実施形態の電着塗装装置を模式的に表した図である。It is the figure which represented typically the electrodeposition coating apparatus of embodiment of this invention.
　次に本発明を実施するための形態を図面に基づいて説明する。この水分散型絶縁皮膜形成用電着液は、ポリマー粒子、有機溶媒、塩基性化合物及び水を含有する。水以外に貧溶媒を含有してもよい。 Next, modes for carrying out the present invention will be described with reference to the drawings. This electrodeposition liquid for forming a water dispersion type insulating film contains polymer particles, an organic solvent, a basic compound and water. A poor solvent may be contained in addition to water.
　＜ポリマー粒子＞
　この電着液に含まれるポリマー粒子は高分子（ポリマー）であるポリアミドイミドから構成される。ポリマー粒子に、ポリアミドイミドからなる粒子を使用する理由は、他のポリマー粒子に比べて耐熱性、可とう性が優れるからである。 <Polymer particles>
The polymer particles contained in the electrodeposition liquid are composed of polyamideimide which is a polymer (polymer). The reason why particles made of polyamideimide are used as polymer particles is that heat resistance and flexibility are superior to other polymer particles.
　ポリマー粒子の平均粒径は、乾燥又は焼成時の発泡を抑制するという観点からは、特に限定されず、一般的な電着液用途に用いられる粒径のものを使用できる。例えば平均粒径が好ましくは、０．０５～１．０μｍの範囲にあるポリマー粒子等を使用することができる。なお、ここで言うポリマー粒子の平均粒径とは、動的光散乱式粒度分布測定装置（株式会社堀場製作所製 型式名:LB-550）により測定された体積基準のメジアン径（Ｄ50）をいう。 The average particle diameter of the polymer particles is not particularly limited from the viewpoint of suppressing foaming during drying or firing, and those having a particle diameter used for general electrodeposition liquid applications can be used. For example, polymer particles having an average particle diameter of preferably 0.05 to 1.0 μm can be used. The average particle diameter of the polymer particles referred to here is a volume-based median diameter (D 50 ) measured by a dynamic light scattering type particle size distribution analyzer (model name: LB-550, manufactured by Horiba, Ltd.). Say.
　ポリマー粒子を構成するポリアミドイミドについては、一般的な電着液用途に用いられているポリアミドイミド等を、当該ポリマー粒子を構成する樹脂として利用できる。例えば、主鎖中にアニオン性基を有するポリアミドイミドであっても、主鎖中にアニオン性基を有しないポリアミドイミドであってもよい。アニオン性基とは、－ＣＯＯＨ基（カルボキシル基）や－ＳＯ3Ｈ（スルホン酸基）等のように、塩基性溶液中でプロトン等が脱離して－ＣＯＯ－基等のマイナス電荷を帯びる性質を有する官能基をいう。主鎖中にアニオン性基を有するポリアミドイミドによって構成されるポリマー粒子を使用すれば、ポリマー粒子の高い表面電位により、粒子間に大きな静電反発力が得られ、電着液中における分散性が向上し、数日保管してもポリマー粒子の凝集又は沈降が抑制される。 About the polyamideimide which comprises a polymer particle, the polyamideimide etc. which are used for the general electrodeposition liquid use can be utilized as resin which comprises the said polymer particle. For example, it may be a polyamideimide having an anionic group in the main chain, or a polyamideimide having no anionic group in the main chain. The anionic group, as such -COOH group (carboxyl group) or -SO 3 H (sulfonic acid group), in a basic solution such as proton is eliminated -COO - nature take on negative charge of such group A functional group having If polymer particles composed of polyamideimide having an anionic group in the main chain are used, a large electrostatic repulsive force is obtained between the particles due to the high surface potential of the polymer particles, and the dispersibility in the electrodeposition liquid is improved. And the aggregation or sedimentation of polymer particles is suppressed even when stored for several days.
　そのため、ポリマー粒子を構成するポリアミドイミドは、ポリマー粒子の凝集又は沈降を抑制する上では主鎖中にアニオン性基を有するものが望ましいが、発泡の抑制という観点からは、特にアニオン性基を有するものに限られない。また、主鎖中にアニオン性基を有するポリアミドイミドは、その合成に使用するモノマーとしてアニオン性基を有するモノマーを使用する必要があり、使用できるモノマーが制限されることから、製造コストが上がる場合がある。このため、低コスト化を図る上では、主鎖中にアニオン性基を有しないポリアミドイミドにて構成されるポリマー粒子を使用するのが望ましい。 Therefore, it is desirable that the polyamideimide constituting the polymer particle has an anionic group in the main chain in order to suppress aggregation or sedimentation of the polymer particle. However, from the viewpoint of suppressing foaming, the polyamideimide particularly has an anionic group. It is not limited to things. In addition, polyamideimide having an anionic group in the main chain needs to use a monomer having an anionic group as a monomer used for the synthesis, and the usable monomer is limited, so that the production cost increases. There is. For this reason, in order to reduce the cost, it is desirable to use polymer particles composed of polyamideimide having no anionic group in the main chain.
　一方、主鎖中にアニオン性基を有しないポリアミドイミドにて構成されるポリマー粒子は、表面電位が比較的小さい値を示す。そのため、粒子間の静電反発力による分散性が十分に得られない場合があるが、粒径や粒度分布等の制御により分散性を高めることは可能である。このため、発泡の抑制に加え、更に低コスト化や凝集又は沈降の抑制を図る場合には、分散性を考慮してポリマー粒子の粒径や粒度分布をより厳密に制御することが望ましい。主鎖中にアニオン性基を有しないポリマー粒子を使用する場合、その体積基準のメジアン径（Ｄ50）が０．０５～０．５μｍであり、かつ粒子径がメジアン径（Ｄ50）の±３０％以内に有る粒子が全粒子の５０％（体積基準）以上であることが好ましい。即ち、このポリマー粒子は、該粒子からなる粉末について体積基準の粒度分布を測定したときに、メジアン径（Ｄ50）が０．０５～０．５μｍの範囲内を示し、かつ当該粒度分布において全粒子数の５０％以上の粒子が、メジアン径（Ｄ50）の±３０％の範囲内（［Ｄ50－０．３Ｄ50］μｍ～［Ｄ50＋０．３Ｄ50］μｍの範囲内）に分布するものである。なお、上記体積基準のメジアン径（Ｄ50）及びメジアン径（Ｄ50）の±３０％の範囲内に分布する粒子の割合（体積基準）は、いずれも動的光散乱式粒度分布測定装置（株式会社堀場製作所製 型式名:LB-550）にて測定した体積基準の粒度分布に基づくものである。また、主鎖中にアニオン性基を有しないポリアミドイミドとは、少なくとも、その主鎖末端以外の炭素原子にアニオン性基を有しないポリアミドイミドをいう。主鎖中にアニオン性基を有しないポリマー粒子の体積基準のメジアン径（Ｄ50）が上記範囲であることが好ましい理由は、この体積基準のメジアン径（Ｄ50）が小さくなりすぎると、後述の絶縁層を形成するときの電着中に、ポリマー粒子が連続膜を形成して、次第に電着効率が低下し、絶縁層の厚膜化が困難になる場合があるからである。また、体積基準のメジアン径（Ｄ50）の制御により、電着によって絶縁層の形成がある程度進行しても、その後の電流の流れを良好に保ちやすくすることができる。その理由は、溶媒中に含まれる導電性のある水が、ポリマー粒子間に存在しやすくなるためである。一方、体積基準のメジアン径（Ｄ50）が大きくなりすぎると、数日保管した電着液に沈殿が生じる場合がある。また、体積基準のメジアン径（Ｄ50）の±３０％の範囲内に分布する粒子の割合が５０％以上であることが好ましい理由は、該粒子の割合が少なくなりすぎても、数日保管した電着液に沈殿が生じる場合があるからである。このうち、アニオン性基を有しないポリマー粒子は、体積基準のメジアン径（Ｄ50）が０．０８～０．２５μｍであり、かつメジアン径（Ｄ50）の±３０％の範囲内に分布する粒子の割合は７５％以上であることがより好ましい。 On the other hand, polymer particles composed of polyamideimide having no anionic group in the main chain exhibit a relatively small surface potential. Therefore, dispersibility due to electrostatic repulsion between particles may not be sufficiently obtained, but dispersibility can be enhanced by controlling the particle size, particle size distribution, and the like. For this reason, in addition to suppressing foaming, it is desirable to more strictly control the particle size and particle size distribution of polymer particles in consideration of dispersibility when further reducing costs and suppressing aggregation or sedimentation. When polymer particles having no anionic group in the main chain are used, the volume-based median diameter (D 50 ) is 0.05 to 0.5 μm, and the particle diameter is ±± of the median diameter (D 50 ). The particles within 30% are preferably 50% (volume basis) or more of all particles. That is, the polymer particles have a median diameter (D 50 ) in the range of 0.05 to 0.5 μm when the volume-based particle size distribution of the powder comprising the particles is measured, Particles of 50% or more of the number of particles are distributed within a range of ± 30% of the median diameter (D 50 ) (within a range of [D 50 -0.3D 50 ] μm to [D 50 + 0.3D 50 ] μm). To do. The volume-based median diameter (D 50 ) and the proportion of particles distributed within a range of ± 30% of the median diameter (D 50 ) (volume basis) are both dynamic light scattering particle size distribution measuring devices ( This is based on the volume-based particle size distribution measured by HORIBA, Ltd. (model name: LB-550). Further, the polyamideimide having no anionic group in the main chain means a polyamideimide having no anionic group at least on carbon atoms other than the end of the main chain. The reason why the volume-based median diameter (D 50 ) of the polymer particles having no anionic group in the main chain is preferably in the above range is that if this volume-based median diameter (D 50 ) is too small, it will be described later. This is because the polymer particles may form a continuous film during electrodeposition when forming the insulating layer, and the electrodeposition efficiency gradually decreases, making it difficult to increase the thickness of the insulating layer. In addition, by controlling the volume-based median diameter (D 50 ), even if the formation of the insulating layer proceeds to some extent by electrodeposition, the subsequent current flow can be easily maintained. The reason is that conductive water contained in the solvent tends to exist between the polymer particles. On the other hand, if the volume-based median diameter (D 50 ) becomes too large, precipitation may occur in the electrodeposition solution stored for several days. The reason why the proportion of particles distributed within a range of ± 30% of the volume-based median diameter (D 50 ) is preferably 50% or more is that even if the proportion of the particles is too small, it is stored for several days. This is because precipitation may occur in the deposited electrodeposition solution. Among these, polymer particles having no anionic group have a volume-based median diameter (D 50 ) of 0.08 to 0.25 μm and are distributed within a range of ± 30% of the median diameter (D 50 ). The proportion of particles is more preferably 75% or more.
　ポリマー粒子を構成するポリアミドイミドは、モノマーに、芳香族ジイソシアネート成分を含むジイソシアネート成分と、トリメリット酸無水物等を含む酸成分とを用い、これらを重合反応させて得られる反応生成物（樹脂）である。 Polyamideimide constituting polymer particles is a reaction product (resin) obtained by polymerizing a diisocyanate component containing an aromatic diisocyanate component and an acid component containing trimellitic anhydride, etc., as monomers. It is.
　ジイソシアネート成分としては、ジフェニルメタン－４，４’－ジイソシアネート（ＭＤＩ）、ジフェニルメタン－３，３’－ジイソシアネート、ジフェニルメタン－３，４’－ジイソシアネート、ジフェニルエーテル－４，４’－ジイソシアネート、ベンゾフェノン－４，４’－ジイソシアネート、ジフェニルスルホン－４，４’－ジイソシアネート等の芳香族ジイソシアネートが挙げられる。 Examples of the diisocyanate component include diphenylmethane-4,4′-diisocyanate (MDI), diphenylmethane-3,3′-diisocyanate, diphenylmethane-3,4′-diisocyanate, diphenylether-4,4′-diisocyanate, and benzophenone-4,4 ′. And aromatic diisocyanates such as diisocyanate and diphenylsulfone-4,4′-diisocyanate.
　また、酸成分としては、トリメリット酸無水物（ＴＭＡ）、１，２，５－トリメリット酸（１，２，５－ＥＴＭ）、ビフェニルテトラカルボン酸二無水物、ベンゾフェノンテトラカルボン酸二無水物、ジフェニルスルホンテトラカルボン酸二無水物、オキシジフタル酸二無水物（ＯＰＤＡ）、ピロメリット酸二無水物（ＰＭＤＡ）、４，４’－（２，２’－ヘキサフルオロイソプロピリデン）ジフタル酸二無水物等の芳香族酸無水物が挙げられる。 The acid component includes trimellitic anhydride (TMA), 1,2,5-trimellitic acid (1,2,5-ETM), biphenyltetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride , Diphenylsulfonetetracarboxylic dianhydride, oxydiphthalic dianhydride (OPDA), pyromellitic dianhydride (PMDA), 4,4 '-(2,2'-hexafluoroisopropylidene) diphthalic dianhydride An aromatic acid anhydride such as
　これらジイソシアネート成分と酸成分とを等量ずつ混合し、有機溶媒中で加熱して重合反応させることにより、ポリアミドイミド樹脂ワニスを得ることができる。なお、上記イソシアネート成分と酸成分はそれぞれ１種類ずつ用いても良いし、複数の種類を組み合わせて使用しても良い。 The polyamide-imide resin varnish can be obtained by mixing the diisocyanate component and the acid component in equal amounts and heating in an organic solvent to cause a polymerization reaction. In addition, the said isocyanate component and an acid component may each be used individually, and may be used combining several types.
　また、ポリマー粒子を構成するポリアミドイミドは、シロキサン結合を有しないものであることが好ましい。シロキサン結合を有すると、シロキサン結合が熱分解しやすいため、絶縁皮膜の耐熱性が劣化する不具合が生じることがあるからである。シロキサン結合の有無は、シロキサン結合を含有するモノマーを使用することに起因するため、シロキサン結合を含有しないモノマーを使用することにより、シロキサン結合を有しないポリマーとすることができる。 Moreover, it is preferable that the polyamideimide constituting the polymer particles does not have a siloxane bond. This is because if the siloxane bond is present, the siloxane bond is likely to be thermally decomposed, so that the heat resistance of the insulating film may be deteriorated. Since the presence or absence of a siloxane bond results from the use of a monomer containing a siloxane bond, a polymer having no siloxane bond can be obtained by using a monomer that does not contain a siloxane bond.
　＜有機溶媒、水、貧溶媒＞
　有機溶媒には、１，３－ジメチル－２－イミダゾリジノン（ＤＭＩ）、Ｎ－メチル－２－ピロリドン、Ｎ，Ｎ－ジメチルホルムアミド、Ｎ，Ｎ－ジメチルアセトアミド、ジメチルスルホキシド、テトラメチル尿素、ヘキサエチルリン酸トリアミドや、γ－ブチロラクタム等の極性溶剤を使用することができる。また、水には、純水、超純水、イオン交換水等が挙げられる。また、水以外に貧溶媒を含有する場合には、貧溶媒には、１－プロパノール、イソプロピルアルコール等の脂肪族アルコール類、２－メトキシエタノール等のエチレングリコール類、１－メトキシ－２－プロパノール等のプロピレングリコール類等を使用することができる。 <Organic solvent, water, poor solvent>
Organic solvents include 1,3-dimethyl-2-imidazolidinone (DMI), N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, tetramethylurea, hexa Polar solvents such as ethyl phosphoric acid triamide and γ-butyrolactam can be used. Examples of water include pure water, ultrapure water, and ion exchange water. When a poor solvent is contained in addition to water, examples of the poor solvent include aliphatic alcohols such as 1-propanol and isopropyl alcohol, ethylene glycols such as 2-methoxyethanol, 1-methoxy-2-propanol, and the like. Propylene glycols or the like can be used.
　＜塩基性化合物（分散剤又は中和剤）＞
　塩基性化合物は、中和剤又は分散剤として電着液中に添加される成分であり、この塩基性化合物には、水とのＨＳＰ距離が３５以上の窒素含有化合物を使用する。ここで、ＨＳＰ（Hansen Solubility Parameter：ハンセン溶解度パラメータ）とは、ある物質がある物質にどれくらい溶けるかを示す溶解性の指標として用いられる値である。このＨＳＰ値は分散項（ｄＤ）、極性項（ｄＰ）、水素結合項（ｄＨ）の３つのパラメータで構成され、各物質ごとに固有の値を示す。これら３つのパラメータは、３次元空間（ハンセン空間）内の座標とみなすことができるため、ＨＳＰ値は上記空間内の０を始点、ＨＳＰ値によって与えられる座標を終点とするベクトルとして表される。ＨＳＰ距離（Ｒａ）とは、２つの物質のＨＳＰ値によって与えられる上記座標間の距離又はベクトル間距離のことであり、一般に下記式（１）により算出される。 <Basic compound (dispersing agent or neutralizing agent)>
The basic compound is a component added to the electrodeposition liquid as a neutralizing agent or a dispersing agent, and a nitrogen-containing compound having an HSP distance of 35 or more with water is used as the basic compound. Here, HSP (Hansen Solubility Parameter) is a value used as a solubility index indicating how much a certain substance is dissolved in a certain substance. This HSP value is composed of three parameters of a dispersion term (dD), a polarity term (dP), and a hydrogen bond term (dH), and shows a unique value for each substance. Since these three parameters can be regarded as coordinates in a three-dimensional space (Hansen space), the HSP value is represented as a vector having 0 in the space as the start point and the coordinate given by the HSP value as the end point. The HSP distance (Ra) is a distance between the coordinates or a vector distance given by the HSP values of two substances, and is generally calculated by the following equation (1).
　ＨＳＰ距離＝[４×(ｄＤ1－ｄＤ2)2＋(ｄＰ1－ｄＰ2)2＋(ｄＨ1－ｄＨ2)2]1/2　（１） HSP distance = [4 × (dD 1 −dD 2 ) 2 + (dP 1 −dP 2 ) 2 + (dH 1 −dH 2 ) 2 ] 1/2 (1)
　上記式（１）中、ｄＤ1、ｄＰ1、ｄＨ1は、２つの物質のうちの一方の物質のＨＳＰ値であり、ｄＤ2、ｄＰ2、ｄＨ2は他方の物質のＨＳＰ値である。この式（１）により算出されるＨＳＰ距離が小さい値を示す物質同士程、２つの物質の相溶性が高いことを示している。水とのＨＳＰ距離が３５以上の窒素含有化合物とは、水のＨＳＰ値（ｄＤ＝１５．５、ｄＰ＝１６、ｄＨ＝４２．３）と窒素含有化合物のＨＳＰ値を上記式（１）に代入して算出される値（ＨＳＰ距離）が３５以上の値となる窒素含有化合物である。 In the above formula (1), dD 1 , dP 1 and dH 1 are HSP values of one of the two substances, and dD 2 , dP 2 and dH 2 are HSP values of the other substance. It shows that the compatibility between the two substances is higher as the substances having a smaller HSP distance calculated by the equation (1). The nitrogen-containing compound having an HSP distance of 35 or more with water means that the HSP value of water (dD = 15.5, dP = 16, dH = 42.3) and the HSP value of the nitrogen-containing compound are expressed in the above formula (1). A nitrogen-containing compound having a value (HSP distance) calculated by substitution of 35 or more.
　電着液中に含まれる塩基性化合物に、水とのＨＳＰ距離が所定値以上の窒素含有化合物を使用することにより、電着液の保存安定性を向上させることができる。これにより、調製後の電着液を長期保存しても電着液の粘度上昇等が抑えられ、塗膜の乾燥又は焼成時に発泡が生じて膜厚が低下するのを抑制できる。このような物性値を示す窒素含有化合物を使用することで電着液の保存安定性が向上する技術的理由は、現在では解明されていないが、例えば次の理由等がその主立った技術的理由として推察される。塩基性化合物はポリマー構造中に結合して電着液の分散性を高める働きをする。塩基性化合物が２－アミノエタノールのように親水性であると、ポリマー粒子に電着液中の水が近づきやすくなるため、ポリアミドイミドが加水分解されやすくなる。ポリアミドイミドが加水分解されると、カルボキシル基やアミノ基といった極性基が生じるため、ＤＭＩ等の極性溶媒や水を引き付け、ポリマーが溶媒を取り込んで一部ゲル化することで液粘度が上昇することが考えられる。一方、水とのＨＳＰ距離が大きく水との親和性が低い、即ち疎水性が高い塩基性化合物を用いると、ポリマー粒子に水を近づけにくいので、上述のような加水分解に伴う電着液の変化を抑制できると考えられる。なお、水とのＨＳＰ距離が少なくとも３５に達する窒素含有化合物であれば特に上限については限定されないが、現在確認できる窒素含有化合物のＨＳＰ値との関係等から、水とのＨＳＰ距離が３５～４５であるものが好ましい。 The storage stability of the electrodeposition liquid can be improved by using, as the basic compound contained in the electrodeposition liquid, a nitrogen-containing compound having an HSP distance with water of a predetermined value or more. Thereby, even if the electrodeposition liquid after preparation is preserve | saved for a long period, the viscosity raise of an electrodeposition liquid etc. are suppressed, and it can suppress that foaming arises at the time of drying or baking of a coating film, and a film thickness falls. The technical reason that the storage stability of the electrodeposition solution is improved by using a nitrogen-containing compound having such physical property values has not been elucidated at present, but the following technical reasons are the main technical reasons. Inferred as The basic compound functions to enhance the dispersibility of the electrodeposition liquid by binding in the polymer structure. If the basic compound is hydrophilic, such as 2-aminoethanol, the water in the electrodeposition solution tends to approach the polymer particles, so that the polyamideimide is easily hydrolyzed. When the polyamideimide is hydrolyzed, polar groups such as carboxyl groups and amino groups are generated, so the viscosity of the liquid rises by attracting polar solvents such as DMI and water, and the polymer takes in the solvent and partially gels. Can be considered. On the other hand, when using a basic compound having a large HSP distance with water and low affinity with water, that is, having a high hydrophobicity, it is difficult to bring water close to the polymer particles. It is thought that change can be suppressed. The upper limit is not particularly limited as long as the HSP distance to water reaches at least 35, but the HSP distance to water is 35 to 45 from the relationship with the HSP value of the nitrogen-containing compound that can be confirmed at present. Are preferred.
　このような物性値を示し、電着液中に含まれる塩基性化合物として好適な窒素含有化合物としては、具体的にはアルキルアミン化合物が挙げられる。更に、アルキルアミン化合物としては、例えばプロピルアミン、ブチルアミン、アミルアミン、ヘキシルアミン、オクチルアミン、デシルアミン等の第１級アルキルアミンや、ジプロピルアミン、ジブチルアミン、ジアミルアミン、ジヘキシルアミン、ジオクチルアミン等の第２級アルキルアミン、トリプロピルアミン、トリブチルアミン、トリアミルアミン、トリヘキシルアミン等の第３級アルキルアミンが挙げられる。このうち、水とのＨＳＰ距離が大きく、高い疎水性を示すことから、トリプロピルアミン、トリブチルアミン、トリアミルアミン、トリヘキシルアミン等が特に好ましい。 Specific examples of nitrogen-containing compounds which exhibit such physical property values and are suitable as basic compounds contained in the electrodeposition liquid include alkylamine compounds. Furthermore, examples of the alkylamine compound include primary alkylamines such as propylamine, butylamine, amylamine, hexylamine, octylamine and decylamine, and second alkylamines such as dipropylamine, dibutylamine, diamylamine, dihexylamine and dioctylamine. Tertiary alkylamines such as tertiary alkylamine, tripropylamine, tributylamine, triamylamine, and trihexylamine are listed. Of these, tripropylamine, tributylamine, triamylamine, trihexylamine, and the like are particularly preferable because of their large HSP distance with water and high hydrophobicity.
　＜電着液の調製＞
　電着液は、例えば、次のような方法で得ることができる。先ず、上述のようにジイソシアネート成分と酸成分と有機溶媒とを用いて、ポリアミドイミド樹脂ワニスを合成する。具体的には、モノマーとしての上記ジイソシアネート成分と上記酸成分をそれぞれ準備し、これらとともに、ＤＭＩ等の有機溶媒をフラスコ内へ所定の割合で投入する。フラスコには、撹拌機や、冷却管、窒素導入管、温度計等を備えた四つ口フラスコを用いるのが好ましい。上記ジイソシアネート成分と酸成分の配合比は、モル比で１：１となる割合とするのが好ましい。また、有機溶媒の割合は、合成後に得られる樹脂の質量の１～３倍に相当する割合とするのが好ましい。これらをフラスコ内へ投入した後は、好ましくは８０～１８０℃の温度まで昇温させ、好ましくは２～８時間反応させる。 <Preparation of electrodeposition solution>
The electrodeposition liquid can be obtained, for example, by the following method. First, a polyamideimide resin varnish is synthesized using a diisocyanate component, an acid component, and an organic solvent as described above. Specifically, the diisocyanate component and the acid component as monomers are respectively prepared, and together with these, an organic solvent such as DMI is introduced into the flask at a predetermined ratio. The flask is preferably a four-necked flask equipped with a stirrer, a cooling pipe, a nitrogen introduction pipe, a thermometer, and the like. The mixing ratio of the diisocyanate component and the acid component is preferably set to a ratio of 1: 1 as a molar ratio. The proportion of the organic solvent is preferably a proportion corresponding to 1 to 3 times the mass of the resin obtained after synthesis. After putting them into the flask, the temperature is preferably raised to a temperature of 80 to 180 ° C., and the reaction is preferably carried out for 2 to 8 hours.
　その後、必要に応じて、上述の有機溶媒で希釈させることにより、不揮発分として合成したポリアミドイミド樹脂を、好ましくは２０～５０質量％の割合で含有するポリアミドイミド樹脂ワニスが得られる。 Thereafter, if necessary, by diluting with the above-mentioned organic solvent, a polyamideimide resin varnish containing a polyamideimide resin synthesized as a non-volatile content, preferably in a proportion of 20 to 50% by mass, is obtained.
　このように合成されたポリアミドイミド樹脂ワニスから、水分散型絶縁皮膜形成用電着液を調製するには、上記調製したポリアミドイミド樹脂ワニスを、必要に応じて上記有機溶媒で更に希釈し、ここに分散剤又は中和剤として上述の塩基性化合物を添加する。このとき、必要に応じて貧溶媒を添加しても良い。そして、好ましくは回転速度８０００～１２０００ｒｐｍにて撹拌しながら、常温下で水を添加して十分に分散させる。貧溶媒を添加する場合には、電着液中の各成分の好ましい割合は、ポリアミドイミド樹脂／有機溶媒／貧溶媒／水／塩基性化合物＝１～１０質量％／６０～７９質量％／残部／１０～２０質量％／０．０５～０．３質量％である。 In order to prepare a water-dispersed insulating film-forming electrodeposition solution from the polyamideimide resin varnish synthesized as described above, the prepared polyamideimide resin varnish is further diluted with the organic solvent as necessary, The above-mentioned basic compound is added as a dispersant or neutralizer. At this time, a poor solvent may be added as necessary. Then, while stirring at a rotational speed of preferably 8000 to 12000 rpm, water is added and dispersed sufficiently at room temperature. When a poor solvent is added, the preferred proportion of each component in the electrodeposition solution is polyamideimide resin / organic solvent / poor solvent / water / basic compound = 1 to 10% by mass / 60 to 79% by mass / balance. / 10 to 20% by mass / 0.05 to 0.3% by mass.
　以上の工程により、上述の水分散型絶縁皮膜形成用電着液が得られる。 Through the above steps, the above-mentioned electrodeposition liquid for forming a water-dispersed insulating film is obtained.
　＜絶縁物の製造＞
　続いて、上記水分散型絶縁皮膜形成用電着液を用いて金属表面に絶縁皮膜が形成された絶縁物の製造方法について、電線の表面に絶縁皮膜が形成された絶縁電線の製造方法を例に図面に基づいて説明する。図１に示すように、電着塗装装置１０を用いて上記電着液１１を電着塗装法により電線１２の表面に電着させて絶縁層２１ａを形成する。具体的には、予め、円筒状に巻き込んである横断面円形の円柱状の電線１３を、直流電源１４の正極に陽極１６を介して電気的に接続しておく。そして、この円柱状の電線１３を図１の実線矢印の方向に引上げて次の各工程を経る。 <Manufacture of insulators>
Subsequently, an example of a method for manufacturing an insulated wire in which an insulating film is formed on the surface of an electric wire is described as an example of a method for manufacturing an insulator in which an insulating film is formed on a metal surface using the water-dispersed insulating film forming electrodeposition liquid. Will be described with reference to the drawings. As shown in FIG. 1, the electrodeposition coating apparatus 10 is used to electrodeposit the electrodeposition liquid 11 on the surface of the electric wire 12 by an electrodeposition coating method to form an insulating layer 21a. Specifically, a cylindrical electric wire 13 having a circular cross section that is wound in a cylindrical shape is electrically connected in advance to the positive electrode of the DC power source 14 via the anode 16. And this cylindrical electric wire 13 is pulled up in the direction of the solid line arrow of FIG. 1, and passes through each next process.
　先ず、第１の工程として、円柱状の電線１３を一対の圧延ローラ１７，１７により扁平に圧延して、横断面長方形の平角状の電線１２を形成する。電線としては、銅線、アルミ線、鋼線、銅合金線、アルミ合金線等が挙げられる。次いで、第２の工程として、電着液１１を電着槽１８に貯留し、好ましくは５～６０℃の温度に維持して、この電着槽１８内の電着液１１中に平角状の電線１２を通過させる。ここで、電着槽１８内の電着液１１中には、通過する平角状の電線１２と間隔を設けて直流電源１４の負極に電気的に接続された陰極１９が挿入される。電着槽１８内の電着液１１中を平角状の電線１２が通過する際に、直流電源１４により直流電圧が平角状の電線１２と陰極１９との間に印加される。なお、このときの直流電源１４の直流電圧は１～３００Ｖとするのが好ましく、直流電流の通電時間は０．０１～３０秒とするのが好ましい。これにより、電着液１１中で、マイナスに帯電したポリマー粒子（図示せず）が平角状の電線１２の表面に電着されて絶縁層２１ａが形成される。 First, as a first step, a cylindrical electric wire 13 is rolled flat by a pair of rolling rollers 17 and 17 to form a rectangular electric wire 12 having a rectangular cross section. Examples of the electric wire include a copper wire, an aluminum wire, a steel wire, a copper alloy wire, and an aluminum alloy wire. Next, as a second step, the electrodeposition liquid 11 is stored in the electrodeposition tank 18 and is preferably maintained at a temperature of 5 to 60 ° C. so that the electrodeposition liquid 11 in the electrodeposition tank 18 has a rectangular shape. The electric wire 12 is passed. Here, a cathode 19 that is electrically connected to the negative electrode of the DC power supply 14 is inserted into the electrodeposition liquid 11 in the electrodeposition tank 18 with a space from the flat rectangular wire 12 passing therethrough. When the rectangular electric wire 12 passes through the electrodeposition liquid 11 in the electrodeposition tank 18, a DC voltage is applied between the rectangular electric wire 12 and the cathode 19 by the DC power source 14. At this time, the DC voltage of the DC power supply 14 is preferably 1 to 300 V, and the DC current application time is preferably 0.01 to 30 seconds. As a result, in the electrodeposition liquid 11, negatively charged polymer particles (not shown) are electrodeposited on the surface of the flat wire 12 to form the insulating layer 21 a.
　次に、表面に絶縁層２１ａが電着された平角状の電線１２に対し、焼付処理を施すことにより、電線１２の表面に絶縁皮膜２１ｂを形成する。この実施の形態では、表面に上記絶縁層２１ａが形成された電線１２を、焼付炉２２内を通過させることにより焼付処理を行う。上記焼付処理は、近赤外線加熱炉、熱風加熱炉、誘導加熱炉、遠赤外線加熱炉等により行われることが好ましい。また焼付処理の温度は２５０～５００℃の範囲内であることが好ましく、焼付処理の時間は１～１０分間の範囲内であることが好ましい。なお、焼付処理の温度は焼付炉内の中央部の温度である。焼付炉２２を通過することにより、電線１２の表面を絶縁皮膜２１ｂで被覆した絶縁電線２３が製造される。 Next, an insulating film 21b is formed on the surface of the electric wire 12 by subjecting the flat electric wire 12 having the insulating layer 21a electrodeposited on the surface thereof to a baking treatment. In this embodiment, the electric wire 12 having the insulating layer 21a formed on the surface thereof is baked by passing through the baking furnace 22. The baking treatment is preferably performed by a near infrared heating furnace, a hot air heating furnace, an induction heating furnace, a far infrared heating furnace, or the like. The temperature of the baking treatment is preferably in the range of 250 to 500 ° C., and the time of the baking treatment is preferably in the range of 1 to 10 minutes. Note that the temperature of the baking treatment is the temperature of the central portion in the baking furnace. By passing through the baking furnace 22, an insulated wire 23 in which the surface of the wire 12 is covered with an insulating film 21b is manufactured.
　次に本発明の実施例を比較例とともに詳しく説明する。 Next, examples of the present invention will be described in detail together with comparative examples.
　＜実施例１＞
　攪拌機、冷却管、窒素導入管及び温度計を備えた２リットルの四つ口フラスコに１，３－ジメチル－２－イミダゾリジノン（ＤＭＩ）３０．９７ｇ、ジフェニルメタン－４，４’－ジイソシアネート７．５０８ｇ（３０ミリモル）及び無水トリメリット酸５．７６４ｇ（３０ミリモル）を仕込み、１６０℃まで昇温させた。約６時間反応させることにより、数平均分子量が４００００のポリマー（ポリアミドイミド樹脂）を合成し、ポリアミドイミド樹脂（不揮発分）の濃度が３０質量％のポリアミドイミドワニス（ポリアミドイミド樹脂／ＤＭＩ＝３０質量％／７０質量％）を得た。 <Example 1>
In a 2 liter four-necked flask equipped with a stirrer, a condenser, a nitrogen inlet tube and a thermometer, 30.97 g of 1,3-dimethyl-2-imidazolidinone (DMI), diphenylmethane-4,4′-diisocyanate 508 g (30 mmol) and trimellitic anhydride 5.764 g (30 mmol) were charged, and the temperature was raised to 160 ° C. By reacting for about 6 hours, a polymer (polyamideimide resin) having a number average molecular weight of 40,000 was synthesized, and a polyamideimide varnish (polyamideimide resin / DMI = 30 mass) having a polyamideimide resin (nonvolatile content) concentration of 30 mass%. % / 70 mass%).
　次いで、上記得られたポリアミドイミドワニス１．７ｇをＤＭＩ４．８ｇで更に希釈し、貧溶媒として１－メトキシプロパノール１．７ｇ、塩基性化合物としてトリプロピルアミン０．０２ｇを加えた後、この液を回転速度１００００ｒｐｍの高速で撹拌しつつ、常温（２５℃）下で水１．８ｇを添加した。これにより、ポリアミドイミド微粒子が分散する電着液（ポリアミドイミド樹脂／ＤＭＩ／貧溶媒／水／塩基性化合物＝５質量％／６０質量％／１７質量％／１８質量％／０．２質量％）を得た。 Next, 1.7 g of the polyamideimide varnish obtained above was further diluted with 4.8 g of DMI. After adding 1.7 g of 1-methoxypropanol as a poor solvent and 0.02 g of tripropylamine as a basic compound, While stirring at a high speed of 10,000 rpm, 1.8 g of water was added at room temperature (25 ° C.). Thereby, the electrodeposition liquid in which the polyamideimide fine particles are dispersed (polyamideimide resin / DMI / poor solvent / water / basic compound = 5 mass% / 60 mass% / 17 mass% / 18 mass% / 0.2 mass%) Got.
　＜実施例２～７及び比較例１＞
　以下の表１に示すように、ポリマー粒子の平均粒径、塩基性化合物の種類、及び電着液中の各成分の割合を変更したこと以外は、実施例１と同様にして電着液を得た。なお、ポリマー粒子の平均粒径は、他の液成分の割合を変更したことにより得られた数値であり、後述する体積基準のメジアン径（Ｄ50）である。 <Examples 2 to 7 and Comparative Example 1>
As shown in Table 1 below, the electrodeposition solution was prepared in the same manner as in Example 1 except that the average particle diameter of the polymer particles, the type of the basic compound, and the ratio of each component in the electrodeposition solution were changed. Obtained. The average particle diameter of the polymer particles is a numerical value obtained by changing the ratio of other liquid components, and is a volume-based median diameter (D 50 ) described later.
　＜比較試験及び評価＞
　実施例１～７及び比較例１で得られた電着液等について、以下の(i)～(iii)の評価を行った。これらの結果を以下の表１又は表２に示す。 <Comparison test and evaluation>
The following (i) to (iii) were evaluated for the electrodeposition solutions obtained in Examples 1 to 7 and Comparative Example 1. These results are shown in Table 1 or Table 2 below.
　(i) 水とのＨＳＰ距離：下記式（１）に、水のＨＳＰ値と、各実施例又は比較例で塩基性化合物として使用した窒素含有化合物のＨＳＰ値をそれぞれ代入することにより、各窒素含有化合物と水のＨＳＰ距離をそれぞれ算出した。窒素含有化合物のＨＳＰ値として、物質の構造式からＨＳＰ値を計算できるソフトウエア（ソフト名：Ｈａｎｓｅｎ　Ｓｏｌｕｂｉｌｉｔｙ　Ｐａｒａｍｅｔｅｒ　ｉｎ　Ｐｒａｃｔｉｃｅ（ＨＳＰｉＰ））により得たＨＳＰ値を用いた。 (i) HSP distance from flooded water: By substituting the HSP value of water and the HSP value of the nitrogen-containing compound used as the basic compound in each Example or Comparative Example, into the following formula (1), The HSP distance of the contained compound and water was calculated respectively. As the HSP value of the nitrogen-containing compound, an HSP value obtained by software capable of calculating the HSP value from the structural formula of the substance (software name: Hansen Solubility Parameter in Practice (HSPIP)) was used.
　ＨＳＰ距離＝[４×(ｄＤ1－ｄＤ2)2＋(ｄＰ1－ｄＰ2)2＋(ｄＨ1－ｄＨ2)2]1/2　（１） HSP distance = [4 × (dD 1 −dD 2 ) 2 + (dP 1 −dP 2 ) 2 + (dH 1 −dH 2 ) 2 ] 1/2 (1)
　(ii) 体積基準のメジアン径（Ｄ50）：各実施例又は比較例で合成したポリマー粒子について、動的光散乱式粒度分布測定装置（株式会社堀場製作所製 型式名:LB-550）により測定された体積基準のメジアン径（Ｄ50）を測定した。 (ii) Volume-based median diameter (D 50 ): measured with a dynamic light scattering particle size distribution analyzer (model name: LB-550, manufactured by Horiba, Ltd.) for the polymer particles synthesized in each Example or Comparative Example The volume-based median diameter (D 50 ) was measured.
　(iii) メジアン径（Ｄ50）の±３０％の範囲内に分布する粒子の割合：上記装置により測定した体積基準の粒度分布から、メジアン径（Ｄ50）の±３０％の範囲内（［Ｄ50－０．３Ｄ50］μｍ～［Ｄ50＋０．３Ｄ50］μｍの範囲内）に分布する粒子の全粒子数に占める割合を算出した。 (iii) Proportion of particles distributed within a range of ± 30% of median diameter (D 50 ): From a volume-based particle size distribution measured by the above apparatus, within a range of ± 30% of median diameter (D 50 ) [[ D 50 -0.3D 50 ] μm to [D 50 + 0.3D 50 ] μm) was calculated as the ratio of the particles distributed to the total number of particles.
　(iii) 保存安定性：各実施例及び比較例で得られた調製直後の電着液と、調整後１ヶ月間保管した電着液を用いて、銅板の表面に絶縁皮膜が成膜された絶縁物を作製し、この絶縁皮膜中の気泡の有無を目視にて観察することにより、電着液の保存安定性を評価した。表２中、「無」は、絶縁皮膜中に気泡が１個も確認されなかったことを示す。また、「有」は、絶縁皮膜中に気泡が１個以上確認されたことを示す。 (iii) Storage stability: An insulating film was formed on the surface of the copper plate using the electrodeposition liquid immediately after preparation obtained in each of the examples and comparative examples and the electrodeposition liquid stored for one month after adjustment. An insulating material was prepared, and the storage stability of the electrodeposition liquid was evaluated by visually observing the presence or absence of bubbles in the insulating film. In Table 2, “None” indicates that no bubbles were observed in the insulating film. “Present” indicates that one or more bubbles were confirmed in the insulating film.
　なお、絶縁物の作製は、後述の手順により行った。また、各実施例及び比較例では、各電着液ごとに、絶縁皮膜の膜厚がそれぞれ１０μｍ、２０μｍ、３０μｍの３つの絶縁物をそれぞれ作製した。上記調製直後の電着液とは、調製後、２４時間経過する前の電着液をいい、また、調整後１ヶ月間保管した電着液とは、調整した電着液をガラス瓶に密封し、大気中、２５℃の温度で１ヶ月間保管した電着液である。また、上記膜厚とは、銅板表面に絶縁皮膜を成膜した後、マイクロメータ（株式会社ミツトヨ製 型式名：MDH-25M）を用いて測定した値である。 The insulator was manufactured according to the procedure described later. In each example and comparative example, for each electrodeposition solution, three insulators having an insulating film thickness of 10 μm, 20 μm, and 30 μm, respectively, were prepared. The electrodeposition liquid immediately after the preparation refers to an electrodeposition liquid before 24 hours have passed after the preparation, and the electrodeposition liquid stored for one month after the adjustment means that the adjusted electrodeposition liquid is sealed in a glass bottle. The electrodeposition liquid stored in the atmosphere at a temperature of 25 ° C. for 1 month. The film thickness is a value measured using a micrometer (Mitutoyo Co., Ltd. model name: MDH-25M) after forming an insulating film on the surface of the copper plate.
　各絶縁物は次の手順により作製した。先ず、電着液を電着槽内に貯留し、この電着槽内の電着液の温度を２５℃に調整した。次に、１８ｍｍ角（厚さは０．３ｍｍ）の銅板とステンレス鋼板をそれぞれ陽極、陰極として用意し、電着液中にこれらを互いに対向させて設置した。そして、銅板とステンレス鋼板との間に直流電圧１００Ｖを印加して電着を行った。その際、クーロンメ－タにより流れた電気量を確認し、電気量が所定量に到達したところで電圧の印加を停止した。なお、膜厚が１０μｍの絶縁皮膜を形成する際には電気量が０．０５Ｃに到達したところで電圧の印加を停止し、膜厚が２０μｍの絶縁皮膜を形成する際には電気量が０．１０Ｃに到達したところで電圧の印加を停止し、膜厚が３０μｍの絶縁皮膜を形成する際には電気量が０．１５Ｃに到達したところで電圧の印加を停止した。これにより銅板の表面に絶縁層を形成した。 Each insulator was produced by the following procedure. First, the electrodeposition liquid was stored in the electrodeposition tank, and the temperature of the electrodeposition liquid in the electrodeposition tank was adjusted to 25 ° C. Next, an 18 mm square (thickness: 0.3 mm) copper plate and stainless steel plate were prepared as an anode and a cathode, respectively, and these were placed facing each other in the electrodeposition solution. And the DC voltage 100V was applied between the copper plate and the stainless steel plate, and electrodeposition was performed. At that time, the amount of electricity flowing by the coulomb meter was confirmed, and the application of voltage was stopped when the amount of electricity reached a predetermined amount. When an insulating film having a film thickness of 10 μm is formed, the application of voltage is stopped when the amount of electricity reaches 0.05 C, and when an insulating film having a film thickness of 20 μm is formed, the amount of electricity is 0.1. When the voltage reached 10 C, the application of voltage was stopped. When an insulating film having a film thickness of 30 μm was formed, the voltage application was stopped when the amount of electricity reached 0.15 C. Thereby, an insulating layer was formed on the surface of the copper plate.
　次に、表面に絶縁層が形成された銅板について焼付処理を行った。具体的には、絶縁層が形成された銅板を、２５０℃の温度に保持された焼付炉に３分間保持することにより行った。これにより、銅板の表面に絶縁皮膜が形成された絶縁物を得た。なお、焼付炉内の温度は、熱電対で測定した炉内中央部の温度である。 Next, the copper plate having an insulating layer formed on the surface was baked. Specifically, the copper plate on which the insulating layer was formed was held for 3 minutes in a baking furnace maintained at a temperature of 250 ° C. Thereby, an insulator having an insulating film formed on the surface of the copper plate was obtained. In addition, the temperature in a baking furnace is the temperature of the center part in a furnace measured with the thermocouple.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表１及び表２から明らかなように、調製直後の電着液を用いた場合には、実施例１～実施例７及び比較例１のいずれの絶縁皮膜にも、乾燥又は焼成時の発泡による気泡はみられなかった。 As is apparent from Tables 1 and 2, when the electrodeposition liquid immediately after preparation was used, any insulating film of Examples 1 to 7 and Comparative Example 1 was caused by foaming during drying or firing. There were no bubbles.
　一方、調製後１ヶ月間保管した電着液で成膜した絶縁皮膜について比較してみると、塩基性化合物として水とのＨＳＰ距離が所定値に満たない窒素含有化合物を使用した比較例１では、全ての膜厚の絶縁皮膜に、乾燥又は焼成時の発泡による気泡が発生した。 On the other hand, when comparing the insulating film formed with the electrodeposition liquid stored for one month after the preparation, in Comparative Example 1 using a nitrogen-containing compound whose HSP distance with water is less than a predetermined value as a basic compound, In the insulating film of all film thickness, bubbles were generated due to foaming during drying or firing.
　これに対し、塩基性化合物として水とのＨＳＰ距離が所定値以上の窒素含有化合物を使用した実施例１～実施例７では、実施例２及び実施例４～６の３０μｍ厚の絶縁皮膜に気泡が若干みられた点を除き、いずれの絶縁皮膜にも乾燥又は焼成時の発泡による気泡はみられなかった。このことから、塩基性化合物として水とのＨＳＰ距離が所定値以上の窒素含有化合物を使用した実施例１～実施例７の電着液は、保存安定性に非常に優れることが確認された。特に、実施例１及び実施例７では、塩基性化合物として水とのＨＳＰ距離がそれぞれ４３．０及び４２．５と大きいため、膜厚が３０μｍでも、乾燥又は焼成時の発泡による気泡はみられなかった。 On the other hand, in Examples 1 to 7 using a nitrogen-containing compound whose HSP distance with water is a predetermined value or more as a basic compound, bubbles are formed in the insulating film having a thickness of 30 μm in Examples 2 and 4 to 6. No air bubbles due to foaming at the time of drying or baking were observed in any of the insulating films except that a slight amount of was observed. From this, it was confirmed that the electrodeposition liquids of Examples 1 to 7 using a nitrogen-containing compound having an HSP distance with water as a basic compound of a predetermined value or more are very excellent in storage stability. In particular, in Examples 1 and 7, the HSP distance with water as a basic compound is as large as 43.0 and 42.5, respectively. Therefore, even when the film thickness is 30 μm, bubbles due to foaming during drying or baking are observed. There wasn't.
　本発明は、パーソナルコンピュータ、スマートフォン等の電源用パワーインダクタのほか、車載用インバータのトランス、リアクトル、モーター等に使用される絶縁電線や、その他の絶縁物の製造に利用することができる。 The present invention can be used for the production of insulated wires used in transformers, reactors, motors, etc. for in-vehicle inverters, as well as power inductors for power supplies of personal computers, smartphones, etc., and other insulators.
　１１　電着液 11 Electrodeposition solution

Claims (2)

  1. 　ポリマー粒子、有機溶媒、塩基性化合物及び水を含有する水分散型絶縁皮膜形成用電着液において、
    　前記ポリマー粒子がポリアミドイミドであり、
    　前記塩基性化合物が水とのＨＳＰ距離が３５以上の窒素含有化合物である
    　ことを特徴とする水分散型絶縁皮膜形成用電着液。     In the electrodeposition liquid for forming a water dispersion type insulating film containing polymer particles, an organic solvent, a basic compound and water,
    The polymer particles are polyamideimide;
    The electrodeposition solution for forming a water-dispersed insulating film, wherein the basic compound is a nitrogen-containing compound having an HSP distance of 35 or more with water.
  2. 　前記塩基性化合物はアルキルアミン化合物である請求項１記載の水分散型絶縁皮膜成形用電着液。 The electrodeposition liquid for forming a water-dispersed insulating film according to claim 1, wherein the basic compound is an alkylamine compound.
PCT/JP2016/078424 2015-12-22 2016-09-27 Aqueous dispersion type electrodeposition liquid for insulating-film formation WO2017110188A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6443578A (en) * 1987-08-10 1989-02-15 Mitsubishi Electric Corp Emulsion for electrodeposition
JP2002020893A (en) 2000-07-06 2002-01-23 Sankyo Seiki Mfg Co Ltd Electrodeposition material, method for forming electrodeposition coating film and sliding device using the material
JP5555063B2 (en) 2010-06-10 2014-07-23 三菱電線工業株式会社 Polyimide electrodeposition paint and method for producing the same

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6443578A (en) * 1987-08-10 1989-02-15 Mitsubishi Electric Corp Emulsion for electrodeposition
JP2002020893A (en) 2000-07-06 2002-01-23 Sankyo Seiki Mfg Co Ltd Electrodeposition material, method for forming electrodeposition coating film and sliding device using the material
JP5555063B2 (en) 2010-06-10 2014-07-23 三菱電線工業株式会社 Polyimide electrodeposition paint and method for producing the same

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