JPWO2008139991A1 - Insulating material - Google Patents

Abstract

It consists of an electrodeposition coating containing a block copolymerized polyimide having a siloxane bond in the molecular skeleton and an anionic group in the molecule, and the heat index in the temperature index evaluation method according to JIS-C-3003 is C type. An insulating member that is insulated by the insulating layer shown. Further, the electrodeposition coating comprises the block copolymerized polyimide, the AC withstand voltage when the layer thickness is 10 μm is 1 kV or more, the AC withstand voltage when the layer thickness is 20 μm is 2 kV or more, and the layer thickness is 30 μm An insulating member that is insulated with an insulating layer having an AC withstand voltage of 3 kV or more. It is a high heat-resistant insulating member that has good adhesion to the member, is less likely to crack, and is insulated with an insulating layer having a high degree of heat resistance. In addition, the insulating member is less likely to be peeled off or cracked, and has a high degree of insulation.

Description

  The present invention relates to an insulating member, and more particularly, an insulating member insulated with a high heat resistant insulating layer, an insulating member insulated with a high voltage resistant insulating layer, and a high heat resistant and high voltage resistant material. The present invention relates to an insulating member that is insulated with a thick insulating layer.

Conventionally, when performing insulation treatment on members (components) that require insulation protection in various technical fields such as automobile parts, home appliances, building materials, electrical / electronic parts, printed circuit board copper wiring, etc. Electrodeposition of an electrodeposition paint is used to form an insulating layer with a highly insulating electrodeposition coating. The applicant of the present application has previously described siloxane as an electrodeposition coating composition capable of forming a highly insulating film that is unlikely to be peeled off or cracked on a member (electrodeposit) to be insulated and protected to obtain such an insulating member. An electrodeposition coating composition containing a specific block copolymerized polyimide having a bond as a resin component has been proposed (Patent Document 1). This electrodeposition coating composition is capable of forming an electrodeposition coating (insulating layer) that is not only excellent in adhesion to the member and flexibility of the coating, but also has good heat resistance and voltage resistance.

However, in recent years, for example, in insulating members used in electrical and electronic parts, automobiles, aerospace, etc., heat resistance requirements have further increased, and for example, in the field of coils for HV car motors and ultra-small motors. Insulating members used are required to have a higher degree of insulation. However, in the proposed electrodeposition coating composition, a high degree of heat resistance and a high degree required for these recent insulating members are required. It is not possible to form an electrodeposition film (insulating layer) that can sufficiently satisfy the insulating properties.
JP-A-2005-162951 International Publication No. WO99 / 19771 US Pat. No. 5,502,143

  In view of the above circumstances, the problem to be solved by the present invention is to provide a highly heat-resistant insulating member that has good adhesion to the member, is less likely to crack, and is insulated with an insulating layer having a high degree of heat resistance. Is to provide. Another object of the present invention is to provide an insulating member that does not easily peel or crack the insulating layer and that exhibits a high degree of insulation. Another object of the present invention is to provide an insulating member having a thick insulating layer having high heat resistance and high voltage resistance.

  As a result of intensive studies to solve the above problems, the present inventors have found that a block copolymer polyimide having a siloxane bond in the molecular skeleton and an anionic group in the molecule has a relatively large particle size. It can be applied to a suspension-type paint dispersed as precipitated particles, and the resulting suspension-type paint can form an electrodeposition film with high uniformity in film properties, and the electrodeposition film has a very high level of heat resistance. In addition, the inventors have found that it is possible to form an electrodeposition coating that is thickened to a level that has been difficult in the prior art, and have completed the present invention.

That is, the present invention is as follows.
(1) It consists of an electrodeposition coating containing a block copolymerized polyimide having a siloxane bond in the molecular skeleton and an anionic group in the molecule, and the temperature index in the temperature index evaluation method based on JIS-C-3003 An insulating member that is insulated with an insulating layer having a temperature of 200 ° C. or higher.
(2) It consists of an electrodeposition coating containing a block copolymerized polyimide having a siloxane bond in the molecular skeleton and an anionic group in the molecule. The AC withstand voltage when the layer thickness is 10 μm is 1 kV or more, and the layer thickness is An insulating member that is insulated by an insulating layer having an AC withstand voltage of 2 kV or more at 20 μm and an AC withstand voltage of 3 kV or more when the layer thickness is 30 μm.
(3) An insulating member comprising an electrodeposited coating containing a block copolymerized polyimide having a siloxane bond in the molecular skeleton and an anionic group in the molecule, and being subjected to an insulation treatment with an insulating layer having a layer thickness exceeding 10 μm .
(4) The electrodeposition coating is an electrodeposition coating by a suspension type electrodeposition coating composition containing a block copolymer polyimide having a siloxane bond in the molecular skeleton and an anionic group in the molecule as a resin component. The insulating member according to any one of (1) to (3) above.
(5) The insulating member according to (4), wherein the block copolymerized polyimide contains a diamine having a siloxane bond in the molecular skeleton as one of the diamine components.
(6) The diamine having a siloxane bond in the molecular skeleton is bis (4-aminophenoxy) dimethylsilane, 1,3-bis (4-aminophenoxy) -1,1,3,3-tetramethyldisiloxane, And the insulating member according to (5), which is one or more selected from the group consisting of compounds represented by the following general formula (I).

(In the formula (I), four R's each independently represents an alkyl group, a cycloalkyl group, a phenyl group, or a phenyl group substituted with 1 to 3 alkyl groups or alkoxyl groups; Each independently represents an integer of 1 to 4, and n represents an integer of 1 to 20).
(7) The four R's in the general formula (I) are each independently an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 7 carbon atoms, a phenyl group, or 1 to 3 carbon atoms. The insulating member according to (6) above, which represents a phenyl group substituted with an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 6 carbon atoms.
(8) The insulating member according to (4), wherein the anionic group is a carboxylic acid group or a salt thereof, and / or a sulfonic acid group or a salt thereof.
(9) The insulating member according to (4), wherein the block copolymerized polyimide contains an aromatic diaminocarboxylic acid as one of the diamine components.
(10) In all diamine components, the proportion of the diamine having a siloxane bond in the molecular skeleton is 5 to 90 mol%, and the proportion of the aromatic diaminocarboxylic acid is 10 to 70 mol% (however, the total of both is 100 mol) % Or less, and may contain a third diamine component).
(11) The insulating member according to any one of (1) to (10), wherein the insulating wire is an insulated wire in which an outer periphery of a conductor wire is covered with the insulating layer.
(12) The insulating member according to (11), wherein the conductor wire has a flat cross-sectional shape.
(13) An insulating coil in which an insulated wire which is an insulating member according to (11) or (12) is wound edgewise or aligned.

  According to the insulating member of the present invention, an extremely high heat-resistant insulating layer in which the heat-resistant species according to the temperature index evaluation method in accordance with JIS-C-3003 indicates C type is firmly adhered to the surface of the member. Since the layer does not easily crack, an insulating member having high heat resistance and high reliability can be realized.

  In addition, according to the insulating member of the present invention, the AC withstand voltage when the layer thickness is 10 μm is 1 kV or more on the member surface, the AC withstand voltage is 2 kV or more when the layer thickness is 20 μm, and the layer thickness is 30 μm. An insulating layer with extremely high voltage resistance that exhibits an AC withstand voltage of 3 kV or more is firmly adhered, and it is difficult for the insulating layer to crack, realizing a highly insulating and highly reliable insulating member. can do.

  Further, according to the insulating member of the present invention, the insulating layer having a thickness exceeding 30 μm having the above extremely high heat resistance and voltage resistance is firmly adhered to the surface of the member, and further, the insulating layer is not cracked. Therefore, it is possible to realize a highly reliable insulating member in which not only insulation protection and heat-resistance protection but also damage protection is achieved by the insulating layer.

FIG. 1 is a schematic view of an apparatus used in an electrodeposition step of an electrodeposition liquid composition in the production of an insulated wire which is a specific example of the insulating member of the present invention. FIG. 2 is a schematic cross-sectional view of a flat insulated wire which is a specific example of the insulating member of the present invention. FIG. 3 compares the relationship between the thickness of the electrodeposition coating (insulating layer) and the AC withstand voltage in the insulating member of the present invention (insulated wire of Example 1) and the conventional insulating member (insulated wire of Comparative Examples 1 and 2). FIG.

Explanation of symbols

1 Flat rectangular insulated wire 2 Conductor wire 3 Insulating layer

Hereinafter, the present invention will be described in more detail.
The term “insulating member” as used in the present invention refers to the formation of an electrodeposition coating (insulating layer) of an electrodeposition paint on the surface of a member (electrodeposit) that requires surface insulation protection in various technical fields. Specifically, the outer periphery of a punched metal plate used for an insulated wire or a laminated transformer coil in which an electrodeposited coating (insulating layer) is formed on the outer periphery of a conductor wire. An electrodeposition coating is formed on the outer periphery of a metal plate that is three-dimensionally formed by cutting or stacking, which is used for insulating metal plates with electrodeposited coatings, needle-shaped metal pins for probe guard measurement, motor cores, etc. Insulated metal plate and the like.

  The material of the member to be insulated (electrodeposit) is not particularly limited, but from the viewpoint of conductivity, copper, copper alloy, copper grat aluminum, aluminum, galvanized iron, silver, gold, nickel, titanium , Tungsten and the like.

  In addition, the member to be insulated (electrodeposit) may be a member obtained by subjecting a member body made of an insulating material to a conductive process such as plating.

  In the insulating member of the present invention, the insulating layer provided on the surface of the member (electrodeposit) has a siloxane bond (—Si—O—) in the molecular skeleton (that is, the main chain of polyimide), and in the molecule. It is formed of an electrodeposition film containing a block copolymerized polyimide having an anionic group.

  In the present invention, “an electrodeposition coating containing a block copolymerized polyimide having a siloxane bond in the molecular skeleton and an anionic group in the molecule” specifically refers to “having a siloxane bond in the molecular skeleton. , An electrodeposition coating obtained by electrodeposition of a suspension-type electrodeposition coating composition in which a block copolymerized polyimide having an anionic group in the molecule is dispersed as precipitated particles having a relatively large particle size " The “suspension type electrodeposition coating composition” is measured using a particle size analyzer ELS-Z2 (manufactured by Otsuka Electronics Co., Ltd.) with an electrophoretic light scattering method (Laser Doppler method), and the measurement result is cumulant. This is a suspension type electrodeposition coating composition in which the polyimide particles analyzed by the analysis method have a particle size of 0.1 to 10 μm and a standard deviation of the particle size of 0.1 to 8 μm.

  The “block copolymerized polyimide” in the “block copolymerized polyimide having a siloxane bond in the molecular skeleton and an anionic group in the molecule” is an imide formed by heating tetracarboxylic dianhydride and diamine. An oligomer is formed (first stage reaction), and then reacted with a tetracarboxylic dianhydride that is the same as or different from the tetracarboxylic dianhydride or / and a diamine different from the diamine (second stage). Reaction) means a copolymerized polyimide obtained by preventing random copolymerization due to an exchange reaction occurring between amic acids.

  In the “block copolymer polyimide having a siloxane bond in the molecular skeleton and an anionic group in the molecule” in the present invention, the siloxane bond in the main chain is a siloxane bond derived from a tetracarboxylic dianhydride component. May be a siloxane bond derived from a diamine component, but is preferably a siloxane bond derived from a diamine component, and usually a siloxane bond (—Si—O—) is added to the molecular skeleton in at least a part of the diamine component. It is a block copolymerized polyimide obtained by using a diamine compound (hereinafter sometimes referred to as “siloxane bond-containing diamine”).

  The siloxane bond-containing diamine is not particularly limited as long as it can be imidized with tetracarboxylic dianhydride. For example, bis (4-aminophenoxy) dimethylsilane, 1,3-bis ( 4-aminophenoxy) -1,1,3,3-tetramethyldisiloxane and the general formula (I):

(Wherein, each of four R's independently represents an alkyl group, a cycloalkyl group, a phenyl group, or a phenyl group substituted with 1 to 3 alkyl groups or alkoxyl groups, and l and m are each Independently represents an integer of 1 to 4, and n represents an integer of 1 to 20.). The compound represented by the general formula (I) includes a single compound in which n is 1 or 2, and polysiloxane diamine.

  In four R in the formula (I), the alkyl group and the cycloalkyl group preferably have 1 to 6 carbon atoms, and more preferably 1 to 2 carbon atoms. In the phenyl group substituted with 1 to 3 alkyl groups or alkoxyl groups, 1 to 3 alkyl groups or alkoxyl groups may be the same or different when they are 2 or 3 May be. Moreover, as for an alkyl group and an alkoxyl group, C1-C6 is respectively preferable, and 1-2 are more preferable.

  In the compound represented by the general formula (I), four Rs in the formula are preferably the same alkyl group (particularly a methyl group) or a phenyl group, and in the formula, l and m are 2 to 3, Polysiloxane diamines with n in the range 5-15 are preferred.

  Preferred examples of the polysiloxane diamine include bis (γ-aminopropyl) polydimethylsiloxane (in the formula (I), l and m are 3 and 4 R are methyl groups), bis (γ-amino). Propyl) polydiphenylsiloxane (in the formula (I), l and m are 3, and four R are phenyl groups).

  In the present invention, the siloxane bond-containing diamine may be a single compound or a combination of two or more compounds. Commercial products may also be used, and those sold by Shin-Etsu Chemical Co., Toray Dow Corning, Chisso can be used as they are. Specifically, KF-8010 (bis (γ-aminopropyl) polydimethylsiloxane: amino group equivalent of about 450), X-22-161A (bis (γ-aminopropyl) polydimethylsiloxane: Shin-Etsu Chemical Co., Ltd .: Amino group equivalent of about 840) and the like, and these are particularly preferable.

  In the “block copolymer polyimide having a siloxane bond in the molecular skeleton and an anionic group in the molecule” in the present invention, the anionic group is a group that becomes an anion in the solvent (described later) of the electrodeposition composition. Preferably, it is a carboxyl group or a salt thereof, and / or a sulfonic acid group or a salt thereof. The anionic group may be contained in a siloxane-containing diamine or a tetracarboxylic dianhydride component, but it is preferable to use a diamine having an anionic group as one of the diamine components. Such an anionic group-containing diamine is preferably an aromatic diamine in order to improve the heat resistance of the polyimide, the adhesion to the electrodeposit, and the degree of polymerization. That is, aromatic diaminocarboxylic acid and / or aromatic diaminosulfonic acid is preferable. Examples of the aromatic diaminocarboxylic acid include 3,5-diaminobenzoic acid, 2,4-diaminophenylacetic acid, 2,5-diaminoterephthalic acid, 3,3′-dicarboxy-4,4′-diaminodiphenylmethane, 3,5-diaminoparatoluic acid, 3,5-diamino-2-naphthalenecarboxylic acid, 1,4-diamino-2-naphthalenecarboxylic acid and the like can be mentioned. As aromatic diaminosulfonic acid, 2,5-diamino Examples thereof include benzenesulfonic acid, 4,4′-diamino-2,2′-stilbene disulfonic acid, o-tolidine disulfonic acid, and the like. Among these, 3,5-diaminobenzoic acid is particularly preferable. Such anionic group-containing aromatic diamines can be used alone or in combination of a plurality of types. When the siloxane bond-containing diamine has an anionic group, the diamine component may be only the siloxane bond-containing diamine.

  As the diamine component, in addition to the above-described siloxane bond-containing diamine and diaminocarboxylic acid, another diamine may be further contained. As such a diamine, an aromatic diamine is usually used in order to improve the heat resistance of the polyimide, the adhesion to the electrodeposit, and the degree of polymerization. Examples of such aromatic diamines include m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 4,4′-diamino-3,3′-dimethyl-1,1′-biphenyl, 4, 4'-diamino-3,3'-dihydroxy-1,1'-biphenyl, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfone, 4,4'-diamino Diphenylsulfone, 4,4′-diaminodiphenyl sulfide, 2,2-bis (4-aminophenyl) propane, 2,2-bis (4-aminophenyl) hexafluoropropane, 1,3-bis (4-aminophenoxy) ) Benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphe Nyl, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, bis [4- (3-aminophenoxy) Phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, 2,6-diaminopyridine, 2,6-diamino-4-methylpyridine, 4,4 ′-(9-fluorenylidene) dianiline, α, α-bis (4-aminophenyl) -1,3-diisopropylbenzene can be mentioned, among others, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] Sulfone is more preferred.

  In the total diamine component, the proportion of the siloxane bond-containing diamine is preferably 5 to 90 mol%, more preferably 15 to 50 mol%. When the siloxane bond-containing diamine unit is less than 5 mol%, the electrodeposition coating film of polyimide is inferior in elongation and it is difficult to obtain sufficient flexibility, so that peeling and cracking are liable to occur. Further, the ratio of the aromatic diaminocarboxylic acid or a salt thereof is preferably 10 to 70 mol% (however, the total of the siloxane bond-containing diamine and the aromatic diaminocarboxylic acid or a salt thereof is 100 mol% or less, Moreover, the 3rd diamine component may be included as above-mentioned.

  On the other hand, as tetracarboxylic dianhydride component in polyimide, aromatic tetracarboxylic dianhydride is usually used from the viewpoint of heat resistance of polyimide and compatibility of polysiloxane diamine, for example, pyromellitic dianhydride. 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride , Bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride Products, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, etc. Among these, heat resistance of polyimide, adhesion to electrodeposits, polysiloxane diamine 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, 3,3 ′, 4,4 from the viewpoint of compatibility and polymerization rate '-Benzophenone tetracarboxylic dianhydride, 3,3', 4,4'-biphenylsulfone tetracarboxylic dianhydride and the like are particularly preferable. These exemplary tetracarboxylic dianhydrides may be used alone or in combination of two or more.

  In the present invention, “a block copolymerized polyimide having a siloxane bond in the molecular skeleton and an anionic group in the molecule” is soluble in a water-soluble polar solvent (for example, N-methyl-2-pyrrolidone (NMP ) Exhibits solubility at a concentration of 5% by weight or more, preferably 10% by weight or more.) Block copolymerized polyimide. The block copolymerized polyimide and the production method thereof are already known (for example, Patent Documents 2 and 3), and the polyimide used in the present invention is the above-described diamine component and tetracarboxylic dianhydride, and a known method is applied. Can be manufactured. A water-soluble polar solvent is used for the polymerization reaction. Specifically, N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP) , Γ-butyrolactone (γBL), anisole, tetramethylurea, and sulfolane, and NMP is preferable. In such a water-soluble polar solvent, tetracarboxylic dianhydride and diamine are added in an approximately equimolar amount (preferably in a molar ratio of 1: 0.95 to 1.05) and heated in the presence of a catalyst to perform a dehydration imidization reaction. To produce a polyimide solution directly. The catalyst is a two-component composite catalyst composed of a lactone and a base or a crotonic acid and a base. The lactone is preferably γ-valerolactone, and the base is preferably pyridine or N-methylmorpholine. The mixing ratio of the lactone or crotonic acid and the base is from 1: 1 to 5 (molar equivalent), preferably from 1: 1 to 2 (molar equivalent). In the presence of water, it acts as an acid-base double salt, exhibits catalytic action, completes imidization, and water comes out of the reaction system (preferably, a polycondensation reaction is performed in the presence of toluene, and water produced is When it is removed from the reaction system together with toluene, the catalytic action is lost. The amount of the catalyst used is usually 1/100 to 1/5 mol, preferably 1/50 to 1/10 mol, relative to tetracarboxylic dianhydride. The mixing ratio (acid / diamine) of tetracarboxylic dianhydride and diamine to be used for the imidization reaction is preferably about 1.05 to 0.95 in terms of molar ratio as described above. The concentration of the acid dianhydride in the entire reaction mixture at the start of the reaction is preferably about 4 to 16% by weight, the concentration of lactone or crotonic acid is preferably about 0.2 to 0.6% by weight, and the concentration of the base Is preferably about 0.3 to 0.9% by weight, and the concentration of toluene is preferably about 6 to 15% by weight. The reaction temperature is preferably 150 ° C to 220 ° C. Moreover, reaction time is not specifically limited, Although it changes with the molecular weight etc. of the polyimide which is going to manufacture, it is about 180 to 900 minutes normally. Moreover, it is preferable to perform reaction under stirring.

  An acid dianhydride and a diamine are heated in a water-soluble polar solvent in the presence of the above-mentioned two-component acid catalyst to form an imide oligomer, and then an acid dianhydride or / and a diamine are added to the second diamine oligomer. A polyimide can be produced by a step reaction. By this method, random copolymerization due to an exchange reaction occurring between amic acids can be prevented. As a result, a block copolymerized polyimide can be produced. The solid concentration at this time is preferably 10 to 40% by weight, more preferably 20 to 30% by weight.

  The polyimide preferably has an inherent logarithmic viscosity (25 ° C.) of 5,000 to 50,000 mPas, more preferably 5,000 to 15,000 mPas, in a 20 wt% NMP solution.

  Further, the weight average molecular weight (Mw) of the block copolymerized polyimide used as the resin component is preferably 20,000 to 150,000, particularly preferably 45,000 to 90,000 in terms of polystyrene. When the weight average molecular weight of the polyimide is less than 20,000, the heat resistance of the electrodeposition coating film tends to decrease, the coating film surface becomes rough, and the aesthetics and withstand voltage characteristics tend to decrease. On the other hand, when the weight average molecular weight is larger than 150,000, the polyimide resin has water repellency with respect to water and easily causes gelation in the electrodeposition liquid (paint) manufacturing process.

  Moreover, about a number average molecular weight (Mn), 10,000-70,000 are preferable in polystyrene conversion, More preferably, it is 20,000-40,000. When the number average molecular weight is less than 10,000, the electrodeposition efficiency tends to decrease, and the heat resistance and voltage resistance may decrease. Here, the molecular weight of polyimide is a molecular weight in terms of polystyrene measured by GPC, and is a value measured by using HLC-8220 manufactured by Tosoh Corporation as a GPC device and using SCKgel Super-H-RC as a column.

  In the suspension-type electrodeposition coating composition used in the present invention, the average particle diameter of the particles made of block copolymerized polyimide is preferably 0.1 to 10 μm, and more preferably 0.5 to 5 μm. When the average particle size is less than 0.1 μm, the Coulomb efficiency is lowered and the withstand voltage performance is lowered due to overvoltage. On the other hand, when the thickness is 5 μm or more, the withstand voltage performance is lowered due to the control of the Coulomb efficiency and the increase of the leakage current due to the increase of the particles. Therefore, the particle size range in which the control of the coulomb efficiency and the maintenance of the withstand voltage performance are balanced is preferably 0.5 to 5 μm.

  The production of the suspension-type electrodeposition coating composition used in the present invention is specifically performed as follows. First, a post-polymerization composition containing a block copolymerized polyimide obtained through the above polymerization reaction (that is, containing a block copolymerized polyimide and a water-soluble polar solvent, and the content of the block copolymerized polyimide is 15 to 25 wt. % Composition) is heated and melted. The heating temperature here is usually about 100 to 180 ° C, preferably about 120 to 160 ° C. When the heating temperature is less than 100 ° C, the block copolymerized polyimide does not dissolve and tends to be difficult to disperse with other solvents, and when it exceeds 180 ° C, hydrolysis tends to occur and the molecular weight tends to decrease.

  Next, a basic compound is added to the heated and melted composition and stirred to neutralize the block copolymer polyimide, and then the composition is cooled to 40 ° C. or lower, and the block copolymer polyimide poor solvent and water are further cooled. Is added and mixed and stirred to prepare a suspension.

  In the manufacturing process of such a coating composition, when the temperature after cooling of the composition after neutralizing the block copolymerized polyimide exceeds 40 ° C., the polyimide tends to be decomposed by the neutralizing agent. The cooling temperature of the composition is more preferably 30 ° C. or lower. If the cooling temperature of the composition is too low, solidification tends to start again, so the lower limit of the cooling temperature is preferably 20 ° C. or higher.

  The basic compound is not particularly limited as long as it can neutralize the anionic group of the block copolymerized polyimide, but a basic nitrogen-containing compound is preferable, for example, N, N-dimethylaminoethanol, triethylamine, and the like. Primary amines such as triethanolamine, N-dimethylbenzylamine and ammonia, secondary amines and tertiary amines. Also, nitrogen-containing five-membered heterocyclic compounds such as pyrrole, imidazole, oxazole, pyrazole, isoxazole, thiazole, isothiazole, and nitrogen-containing six-membered heterocyclic compounds such as pyridine, pyridazine, pyrimidine, pyrazine, piperidine, piperazine, morpholine And nitrogen-containing heterocyclic compounds such as In addition, since many aliphatic amines have a strong odor, nitrogen-containing heterocyclic compounds are preferred from the viewpoint of low odor. In consideration of the toxicity of the paint, piperidine and morpholine having low toxicity are preferable among the nitrogen-containing heterocyclic compounds. The basic compound may be used in such an amount that the acidic group in the polyimide is stably dissolved or dispersed in the aqueous solution, and is usually about 30 to 200 mol% of the theoretical neutralization amount.

  Examples of the poor solvent for the block copolymer polyimide include alcohols or ketones having a phenyl group, a furfuryl group, or a naphthyl group. Specifically, acetophenone, benzyl alcohol, 4-methylbenzyl alcohol, 4- Examples include methoxybenzyl alcohol, ethylene glycol monophenyl ether, phenoxy-2-ethanol, cinnamyl alcohol, furfuryl alcohol, and naphthyl carbinol. An aliphatic alcohol solvent is preferred because of its low toxicity, and an aliphatic alcohol solvent having an ether group is particularly preferred. For example, as the aliphatic alcohol solvent, 1-propanol, isopropyl alcohol, ethylene glycols, and propylene glycols can be used. Examples of ethylene glycols and propylene glycols include dipropylene glycol, tripropylene glycol, ethylene glycol monoethyl ether, propylene glycol monomethyl ether (1-methoxy-2-propanol), propylene glycol methyl ether acetate, and the like. These poor solvents can use 1 type (s) or 2 or more types.

  The blending amount of the poor solvent is preferably 10 to 40% by weight and more preferably 10 to 30% by weight with respect to the total amount of the composition. The amount of water is preferably 10 to 30% by weight, more preferably 15 to 30% by weight, based on the total amount of the composition.

  In addition to the poor solvent and water of the block copolymer polyimide, an appropriate amount of a water-soluble polar solvent or an oil-soluble solvent may be added for the purpose of adjusting the viscosity and electrical conductivity of the composition. Here, specific examples of the water-soluble polar solvent include the same water-soluble polar solvent used for the polymerization reaction of the block copolymerized polyimide, and examples of the oil-soluble solvent include N-methylpyrrolidone and γ-butyrolactone. Is mentioned. In addition, when adding an oil-soluble solvent, the quantity is 15 weight% or less with respect to the composition whole quantity.

  The solid concentration of the suspension-type electrodeposition coating composition used in the present invention is preferably 1 to 15% by weight, more preferably 5 to 10% by weight. The content of the water-soluble polar solvent is preferably 25 to 60% by weight, more preferably 35 to 55% by weight, based on the total amount of the composition.

The block copolymer polyimide dispersed in the suspension-type electrodeposition coating composition used in the present invention preferably has an average particle size of 0.5 to 5 μm and a standard deviation of the particle size of 0.3 to 3 μm. The inherent logarithmic viscosity of the suspension type electrodeposition coating composition is preferably 5 to 100 mPas.
Using the suspension-type electrodeposition coating composition used in the present invention and performing electrodeposition using a copper wire having a diameter of 1.0 mm and a length of 20 cm, a polyimide film having a thickness of 15 to 250 μm per coulomb can be formed. it can.

  In the insulating member of the present invention, a suspension-type electrodeposition coating composition containing a block copolymer polyimide having a siloxane bond in the molecular skeleton and an anionic group in the molecule as a resin component is electrodeposited. By forming an electrodeposited film, the electrodeposited film adheres firmly to the member (electrodeposit) and is excellent in flexibility that is difficult to crack, and has extremely high heat resistance. The temperature index in the temperature index evaluation method based on JIS-C-3003 is 200 ° C. or higher (that is, the heat-resistant classification indicates C type or higher). The electrodeposited film has extremely high voltage resistance. When the layer thickness is 10 μm, the AC withstand voltage is 1 kV or more, when the layer thickness is 20 μm, the AC withstand voltage is 2 kV or more, and the layer thickness is 30 μm. This is an insulating layer having an AC withstand voltage of 3 kV or more. Such a high heat resistance and a high withstand voltage have the above-described suspension-type electrodeposition coating composition having a high electric conductivity in the growth process of the coating film, and a film property on the surface of the member (electrodeposit). This is considered to be for growing a highly uniform film.

  In addition, the suspension type electrodeposition coating composition described above may be due to the fact that the dispersed particles (precipitated particles) of the block copolymerized polyimide are likely to deposit (adhere) on the surface of the member (electrodeposit). It is possible to grow an electrodeposition film having a thickness exceeding 30 μm, which has been difficult with a product. Therefore, by forming a film having a thickness of more than 30 μm, it is possible to realize an insulating member that is protected not only from insulation protection and heat resistance but also from damage protection by the insulating layer. Therefore, according to the insulating member of the present invention, the insulating layer having a thickness exceeding 30 μm having the above extremely high heat resistance and voltage resistance is firmly adhered to the surface of the member, and the insulating layer is cracked. Therefore, it is possible to realize a highly reliable insulating member in which not only insulation protection and heat resistance protection but also damage protection is achieved by the insulating layer.

  The electrodeposition coating composition proposed by the applicant of the present application in Patent Document 1 includes a block copolymer polyimide having a siloxane bond in the molecular skeleton and an anionic group in the molecule as a resin component. This is common with the above-described suspension type electrodeposition coating composition used in the invention. However, as described above, the electrodeposition coating composition proposed in Patent Document 1 is a liquid phase dispersion or solution type composition, and has the highest heat resistance classification according to the temperature index evaluation method based on JIS-C-3003. Only an F-type electrodeposition coating (insulating layer) can be formed, and the AC withstand voltage when the layer thickness is 10 μm shows at most about 0.3 kV. Even if the electrodeposition conditions are variously changed, it is difficult to form an electrodeposition film (insulating layer) having a thickness exceeding 30 μm.

  The insulating member of the present invention comprises a member (electrodeposit) immersed in the above-described suspension-type electrodeposition coating composition, and polyimide on the member (electrodeposit) through the current using the member (electrodeposit) as an anode. An electrodeposition operation for growing a film is performed, and the obtained film is dried by heating (baking).

  Electrodeposition can be performed by the constant current method or the constant voltage method. For example, in the case of the constant current method, the conditions of current value: 1.0 to 200 mA, DC voltage: 5 to 200 V (preferably 30 to 120 V) are used. Can be mentioned. The electrodeposition time varies depending on the electrodeposition conditions, the thickness of the electrodeposition film to be formed, etc., but is generally selected from the range of 10 to 120 seconds, preferably 30 to 60 seconds. Moreover, the composition temperature at the time of electrodeposition is 10-40 degreeC normally, Preferably it is 10-40 degreeC, More preferably, it is 20-30 degreeC. If the electrodeposition voltage is lower than 5V, it tends to be difficult to form a coating film by electrodeposition. If the electrodeposition voltage is higher than 200V, the generation of oxygen from the coated material becomes intense and a uniform coating film cannot be formed. . Also, if the electrodeposition time is shorter than 10 seconds, the coating film is difficult to grow even if the electrodeposition voltage is set high, so that pinholes are likely to occur, and the withstand voltage performance of the electrodeposition film is significantly reduced. Yes. On the other hand, if it exceeds 120 seconds, the thickness of the coating film becomes thicker than necessary, and it is not economical. Further, when the composition temperature is lower than 10 ° C., it is difficult to form a coating film by electrodeposition, and when it is higher than 50 ° C., temperature management is required, which increases the production cost.

  Baking is performed at 70 to 110 ° C. for 10 to 60 minutes in the first stage, then at 160 to 180 ° C. for 10 to 60 minutes in the second stage and further at 200 to 220 ° C. for 30 to 30 minutes. It is preferable to perform a third stage baking process for 60 minutes. By performing such a three-stage baking process, it is possible to form a sufficiently dried polyimide film that adheres to the member (electrodeposition deposit) with high adhesion.

  When an insulated wire is produced as the insulating member, the electrodeposition and baking operations of the suspension type electrodeposition coating composition are preferably performed with an apparatus as shown in FIG. 1, for example. That is, the conductor wire 11 wound around the roll 10 is pulled out and passed through the electrodeposition bus 12 filled with the electrodeposition coating composition 13 while being connected to the anode side of the AC power source. A cathode tube 14 is disposed in the electrodeposition bus 12, and polyimide is applied to the conductor wire due to the potential difference between the conductor wire 11 serving as the anode and the cathode tube 14 serving as the cathode due to the application of the voltage when passing through the conductor wire 11. 11 is deposited almost uniformly. After the electrodeposition bus 12, the conductor wire 11 passes through the drying device 15. In the drying device 15, the water in the polyimide deposited on the conductor wire 11 evaporates. After passing through the drying device 15, a coating film (insulating layer) made of polyimide is formed by passing through a baking furnace 16, and the insulated conductor is wound up by a roll 20. By performing the electrodeposition and baking operations of the electrodeposition coating composition with such an apparatus, an insulated wire can be continuously produced.

  The material of the conductor wire of the insulated wire is preferably copper, copper alloy, copper clad aluminum, aluminum, galvanized iron, silver or the like from the viewpoint of conductivity, and copper is particularly preferable. In addition, the shape of the insulated wire is not limited to a circular insulated wire having a circular cross-sectional shape (that is, an insulated wire having an insulating layer formed by an electrodeposition coating on the outer periphery of a conductor wire having a circular cross-sectional shape). A flat insulated wire having a flat surface shape (that is, an insulated wire having an insulating layer formed by an electrodeposition coating on the outer periphery of a conductor wire having a flat cross-sectional shape) may be used. Whether it is a round insulated wire or a flat insulated wire is selected according to the specific application of the insulated wire. Here, “flat angle (shape)” means a rectangle or a square (shape). A circular insulated wire is used for applications such as general-purpose motors and electromagnetic coils. In addition, the flat insulated wires are used for applications such as drive motors of various electric devices, coils of portable precision devices such as mobile phones utilizing light weight and high output.

  As described above, the electrodeposition coating of the suspension-type electrodeposition coating composition used in the present invention has a siloxane bond in the molecular skeleton and a block copolymer polyimide having an anionic group in the molecule as a resin component. Electrodeposition not only for conductor wires with a circular cross-sectional shape but also for rectangular conductors with a cross-sectional shape that is firmly attached to a member (electrodeposit) and excellent in flexibility. The insulating layer formed by the coating uniformly coats the outer periphery with high adhesion, and a flat insulated wire having a polyimide coating satisfactorily covered not only at the flat portion of the outer periphery of the conductor wire but also at the corner portion can be obtained. Therefore, the insulated wire has excellent process resistance that is unlikely to cause peeling or cracking of the insulating layer (electrodeposition coating) when it is bent.

  In the present invention, the insulated wire is suitable for an insulated wire for automobile use and high-performance electronic equipment that requires high heat resistance and voltage resistance. FIG. 2 is a schematic cross-sectional view of a rectangular insulated wire 1 in which a rectangular conductor wire 2 (thickness t1, width W1) is covered with an electrodeposition coating (insulating layer) 3. The thickness of the electrodeposited coating (insulating layer) 3 is preferably 1.5 to 50 μm, more preferably 5 to 30 μm, in the flat portion on the outer periphery of the flat conductor wire 2. On the other hand, the corner portion on the outer periphery of the conductor wire 2 has a thickness of at least a flat portion in order to prevent a decrease in AC withstand voltage at the corner portion (the corner portion is liable to cause electric field concentration and thus has an influence on withstand voltage characteristics). The thickness is preferably 0.8 times or more, more preferably 0.9 times or more. Specifically, the thickness of the corner portion is 0.8 to 2 times the thickness of the flat portion, preferably 0.9 from the viewpoint of withstand voltage characteristics and miniaturization and weight reduction of the insulated wire (coil using the insulated wire). It is -1.5 times, More preferably, it is 1.0 times -1.2 times. When the thickness at the corner portion on the outer periphery of the conductor wire is less than 0.8 times the thickness at the flat portion, the AC withstand voltage at the corner portion tends to greatly decrease due to electric field concentration. Further, when the thickness at the corner portion of the outer periphery of the conductor wire exceeds twice the thickness at the flat portion, it tends to be difficult to reduce the size and weight. As shown in FIG. 2, the thickness of the insulating layer covering the outer periphery of the flat conductor wire 1 is the thickness of the insulating layer 3 at the center point of the long side in the rectangular cross section of the flat conductor wire 2 ( The thickness of the insulating layer at the outer peripheral corner of the flat conductor wire 1 is the corner between the long side and the short side in the rectangular cross section of the flat conductor wire 2. The thickness of the insulating layer 3 that covers (D2 in FIG. 2).

  An insulated coil can be obtained by winding the above-described flat insulated wire by a known method such as edgewise winding, aligned winding, or alpha (α) winding. Since the insulating coil is composed of an insulated wire having a flexible electrodeposition coating as an insulating layer, the insulating layer may be peeled off even when processing the insulating coil (especially edgewise winding). It wo n’t break.

  The insulating coil becomes a highly durable insulating coil having high heat resistance and high voltage resistance. Specific applications of the insulating coil include a motor coil, a transformer coil, a substrate mounting component (SMD) coil, a small high-performance motor coil, a small electronic device coil, etc. Among them, downsizing is required. It is suitable as a coil for small high-performance motors and coils for small electronic devices.

  Other specific examples of the insulating member of the present invention include each ring-shaped insulating plate in an insulating coil configured by laminating a plurality of ring-shaped insulating plates. The ring-shaped insulating plate is, for example, an insulating plate in which a cross-sectional shape is a rectangular shape and a planar shape having an open portion is an insulating coating with an electrodeposition coating on a ring-shaped conductive plate.

  In the insulating member of the present invention, the thickness of the electrodeposited coating (insulating layer) varies depending on the type and application of the insulating member, the location and form of the insulating member in the apparatus and equipment, and is not particularly limited. In general, it is selected within the range of 1.5 to 50 μm. That is, in the present invention, an electrodeposited film (insulating layer) having a thickness exceeding 30 μm can be formed, but the upper limit of the thickness is usually about 50 μm because of the uniformity of the film thickness, excess performance, and productivity.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples.
Example 1
[Preparation of electrodeposition coating composition]
A 2-liter separable three-necked flask equipped with a stainless steel vertical stirrer was equipped with a ball condenser equipped with a water separation trap. The flask was charged with 58.84 g (200 mmol) of 3,3′4,4′-biphenyltetracarboxylic dianhydride, 43.25 g (100 mmol) of bis- [4- (4-aminophenoxy) phenyl] sulfone, γ -After charging 4.0 g (40 mmol) of valerolactone, 6.3 g (80 mmol) of pyridine, 531 g of N-methyl-2-pyrrolidone (NMP) and 50 g of toluene, the mixture was stirred for 10 minutes at 180 rpm in a nitrogen atmosphere at room temperature. The mixture was heated to 180 ° C. and stirred for 2 hours. During the reaction, toluene-water azeotrope was removed. Next, the mixture was cooled to room temperature, 64.45 g (200 mmol) of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 83.00 g (100 mmol) of KF-8010 manufactured by Shin-Etsu Chemical Co., Ltd., 3 , 5-Diaminobenzoic acid 30.43 g (200 mmol), NMP 531 g and toluene 50 g were added and reacted for 8 hours while stirring at 180 ° C. and 180 rpm. By removing the refluxed product out of the system, a 20 wt% polyimide solution (20% polyimide varnish) was obtained. The number average molecular weight and weight average molecular weight of the obtained polyimide were 24,000 and 68,000, respectively.

  The obtained polyimide varnish was applied on a glass plate with a wet film thickness of 50 μm using a bar coater. Then, after drying at 90 ° C./30 minutes, 180 ° C./30 minutes, 220 ° C./30 minutes with a hot air drier, peel from the glass plate, and measure the mechanical elongation according to JIS C 2151. 21.8% of polyimide film was obtained. The thermal decomposition temperature was 420 ° C.

  100 g of the 20% polyimide varnish obtained above was stirred at 160 ° C. for 1 hour in a nitrogen atmosphere, and then rapidly cooled to 30 ° C., 59.4 g of N-methylpyrrolidone and 2.2 g of piperidine (neutralization rate 200 mol%) And stirred vigorously. Thereafter, the mixture was stirred while adding 129 g of propylene glycol monomethyl ether, and 67 g of water was added dropwise to prepare an electrodeposition solution. Using a particle size analyzer ELS-Z2 (manufactured by Otsuka Electronics Co., Ltd.), when the particle size and standard deviation of the dispersed particles in the electrodeposition solution were measured, precipitated particles having a particle size of 0.7 μm and a standard deviation of 0.5 μm A suspension having (solid particles) was formed. In addition, it was a black turbid liquid with a solid content concentration of 6.0%, pH of 8.7, and electric conductivity of 7.3 mS / m. The intrinsic log viscosity was 50 mPas.

[Production of insulated wires]
Using the above electrodeposition liquid composition, the electrode-to-adhered distance is 50 mm, the electrodeposition voltage is 30 V, the electrodeposition current is in the range of 0.01 to 200 mA, and the electrodeposition time is in the range of 10 to 60 seconds. The electrode is electrodeposited on the outer periphery of a circular copper wire having a diameter of φ1.0 mm and a length of 20 cm, and the electrodeposited copper wire is taken out from the electrodeposition bath, washed with water, then washed at 90 ° C. for 30 minutes, and further at 170 ° C. × 30 By baking for further 30 minutes at 220 ° C. for 30 minutes, circular insulated copper wires (number of samples per electrodeposition condition = 5) having electrodeposition films (insulating layers) of various thicknesses were obtained. And about the obtained circular insulated copper wire, the electrodeposition property (film formation property) of the electrodeposition liquid, the thickness of the electrodeposition film, the AC withstand voltage and the heat resistance life were evaluated by the following test methods. The results of typical examples are shown in Table 1 below.

1. Uniformity of coating In accordance with JIS C 3003, the presence or absence of pinholes was investigated.

2. The thickness of the electrodeposition coating was measured using a micrometer (minimum scale: 0.1 mm). The thickness at five locations per sample was measured, and the average value was taken as the measurement result for that sample. Table 1 shows the maximum thickness and the minimum thickness of five samples.

3. AC breakdown voltage of electrodeposited coating AC breakdown voltage was measured by B metal foil method according to JIS-C-3003. That is, 1 cm of tin foil was wound around an insulated wire and measured between the conductor and tin foil. Then, an AC voltage generator was connected to each plate, the voltage was increased at a rate of 100 V per second, and the short-circuited voltage (leakage current value of 10 mA or more) was taken as the breakdown voltage. Table 1 shows the average value of five samples.

4). Heat-resistant life of electrodeposited coating Insulated wires prepared in Example 1 with a thickness of 21 to 23 μm (Table 1-No. 5) were insulated in accordance with the temperature index evaluation method described in JIS-C-3003 The heat resistance of the electric wire (heat resistant life of the electrodeposition coating) was evaluated. That is, two test pieces were obtained by twisting two of the insulated wire samples prepared in Example 1 having a film thickness of 21 to 23 μm (Table 1-No. 5). This test piece was heat-treated in an oven set at a temperature of 290 to 320 ° C. at intervals of 10 ° C. (290 ° C., 300 ° C., 310 ° C., 320 ° C.), and each was destroyed by applying a voltage of 500 V × 1 second. The time to reach was measured. The temperature index was calculated from a heat resistant life graph in which the measurement results at temperatures of 290 ° C., 300 ° C., 310 ° C., and 320 ° C. were Arrhenius plotted. The heat-resistant temperature corresponding to a life of 20,000 hours, that is, the temperature index is 240 ° C., and the heat-resistant classification corresponds to Class C having a temperature of 200 ° C. or higher.

Comparative Example 1
After 100 g of a semisolid composition containing 20% by weight of the block copolymerized polyimide (resin component) obtained in Example 1 was heated and melted at 160 ° C., 70 g of NMP was added, 55 g of anisole, 45 g of cyclohexanone and N-methyl were added. 2.6 g of morpholine (neutralization rate: 200 mol%) was added, and 30 g of water was added dropwise with stirring to obtain an electrodeposition liquid composition having a solid content concentration of 6.6% and a pH of 7.8. The particle size and standard deviation of the dispersed particles in the electrodeposition liquid were measured using a particle size analyzer ELS-Z2 (manufactured by Otsuka Electronics Co., Ltd.), but no precipitated particles having a particle size of 0.1 μm or more were observed. . And using this electrodeposition liquid composition, the distance between electrodes is 50 mm, the electrodeposition voltage is 160 V, the electrodeposition current is in the range of 0.01 to 200 mA, and the electrodeposition time is in the range of 10 to 60 seconds. In various modifications, electrodeposition was performed on the same copper wire as the circular copper wire used in Example 1, and thereafter, in the same manner as Example 1, electrodeposition films (insulating layers) with various thicknesses were provided. A circular insulated copper wire was obtained (number of samples per electrodeposition condition = 5). And by the above-mentioned test method, the electrodeposition property (film formation property) of the electrodeposition liquid, the thickness of the electrodeposition film, the AC withstand voltage, and the heat resistant life of the electrodeposition film were evaluated.
Table 2 below shows the results of representative examples. The temperature index was 180 ° C. and the heat resistance category was H.

Comparative Example 2
Electrodeposition was performed in the same manner as in Comparative Example 1 except that the electrodeposition liquid composition prepared in Comparative Example 1 was used and the electrodeposition voltage was changed to 250 V. Electrodeposition films (insulating layers) having various thicknesses A circular insulated copper wire having a thickness of 5 was obtained (number of samples per electrodeposition condition = 5).

  In the following Table 3 and FIG. 3, the characteristic lines of the relationship between the thickness of the electrodeposited coating (horizontal axis) and the AC withstand voltage (vertical axis) of the circular insulated copper wires obtained in Example 1 and Comparative Examples 1 and 2 are shown. The comparison is shown. From the following Table 3 and FIG. 3, in the insulated wire of Example 1 obtained by electrodeposition of the suspension type paint composition, the insulated wire of the comparative example (Comparative Examples 1 and 2) using the conventional solution type paint composition As compared with the above, it can be seen that the film growth rate is high, the AC withstand voltage per unit thickness is excellent, and the electrodeposition film (insulating film) can be thickened to 30 μm or more. Even with conventional solution-type coating compositions, it is possible to increase the film growth rate by increasing the electrodeposition voltage. From the comparison between Comparative Example 1 and Comparative Example 2, the AC withstand voltage of the film increases as the voltage increases. It turns out that falls.

Example 2
Prepared in Example 1 on the outer periphery of a rectangular copper wire (total length 30 cm) having a cross section of 1.8 mm × 0.08 mm under the electrodeposition conditions of voltage 300 V, electrodeposition current (Max) 200 mA, electrodeposition time 30 seconds. The electrodeposition liquid composition was electrodeposited.
Next, the copper wire after electrodeposition is taken out from the electrodeposition bath, washed with water, and baked at 90 ° C. for 30 minutes, further at 170 ° C. for 30 minutes, and further at 220 ° C. for 30 minutes, so that a siloxane bond-containing block copolymerized polyimide is obtained. A rectangular insulated copper wire having an insulating layer was obtained.

  The average thickness (D1) of the portion covering the flat portion of the flat copper wire of the insulating layer was 20 μm, and the average thickness (D2) of the portion covering the corner portion was 19 μm. The average thickness (D1) here is the thickness of the insulating layer at the midpoint of each of the two long sides of the cross section of the copper wire (rectangle) at the five cross sections of the 30 cm length of the flat insulated copper wire (total) The average thickness (D2) of the portion covering the corner portion is the thickness of the insulating layer at the four corner portions of the copper wire cross section (rectangle) at the five cross sections (total). The average value of 20 thicknesses). The thickness of the insulating layer was measured by image processing from a cross-sectional photograph using a microscope.

  The obtained flat rectangular copper wire was subjected to the following flexibility test, and the insulation corner cover property was evaluated by the following method. In the flexibility test, the coating did not crack and the cover property was good (passed) )Met.

(Flexibility test)
(1) Presence / absence of coating peeling by self-diameter winding Take three test pieces of the appropriate length from the same reel, and wind them ten times tightly so that the wires come into contact with each other around the test piece itself. The film was visually inspected for cracks where the conductor could be seen.

(2) Presence / absence of coating peeling in edgewise coil winding.
Two test pieces of about 20cm in length are taken from the same reel, and the central part is flatwise and edgewise at 180 ° while keeping it in one plane along the outer periphery of a round bar having a specified diameter. When bent, the film was visually inspected for cracks where the conductor could be seen.

(Insulation corner cover)
The case where the average thickness (D2) of the insulating layer at the corner of the cross section of the insulated rectangular copper wire is 0.8 times or more the average thickness (D1) of the insulating layer at the flat portion is acceptable, and less than 0.8 times. The case was rejected.

The insulating member of the present invention is a highly reliable insulating member that is not only insulated and heat-resistant, but also capable of protecting the wound, and can be used in the electrical / electronic parts-related, automobile field, aerospace field, and the like. Moreover, it can be used in the field of coils for HV car motors and ultra-small motors that require a higher degree of insulation.
This application is based on patent application No. 2007-122730 filed in Japan, the contents of which are incorporated in full herein.

Claims (13)

  It consists of an electrodeposition coating containing a block copolymerized polyimide having a siloxane bond in the molecular skeleton and an anionic group in the molecule, and the temperature index in the temperature index evaluation method based on JIS-C-3003 is 200 ° C. or higher. An insulating member that is insulated by an insulating layer.   When it consists of an electrodeposition coating containing a block copolymerized polyimide having a siloxane bond in the molecular skeleton and an anionic group in the molecule, the AC withstand voltage when the layer thickness is 10 μm is 1 kV or more, and the layer thickness is 20 μm An insulating member obtained by insulation treatment with an insulating layer having an AC withstand voltage of 2 kV or more and an AC withstand voltage of 3 kV or more when the layer thickness is 30 μm.   An insulating member comprising an electrodeposition coating containing a block copolymerized polyimide having a siloxane bond in the molecular skeleton and an anionic group in the molecule, and being subjected to an insulation treatment with an insulating layer having a layer thickness of more than 10 μm.   The electrodeposition coating is an electrodeposition coating by a suspension type electrodeposition coating composition containing a block copolymer polyimide having a siloxane bond in a molecular skeleton and an anionic group in a molecule as a resin component. The insulating member according to any one of 1 to 3.   The insulating member according to claim 4, wherein the block copolymerized polyimide contains a diamine having a siloxane bond in a molecular skeleton as one of the diamine components. The diamine having a siloxane bond in the molecular skeleton is bis (4-aminophenoxy) dimethylsilane, 1,3-bis (4-aminophenoxy) -1,1,3,3-tetramethyldisiloxane, and The insulating member according to claim 5, wherein the insulating member is one or more selected from the group consisting of compounds represented by formula (I).

(In the formula, four R's each independently represents an alkyl group, a cycloalkyl group, a phenyl group, or a phenyl group substituted with 1 to 3 alkyl groups or alkoxyl groups, and l and m are each independently And represents an integer of 1 to 4, and n represents an integer of 1 to 20).   Four Rs in the general formula (I) are each independently an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 7 carbon atoms, a phenyl group, or 1 to 3 carbon atoms having 1 to 3 carbon atoms. The insulating member according to claim 6, which represents a phenyl group substituted with an alkyl group having 6 or an alkoxyl group having 1 to 6 carbon atoms.   The insulating member according to claim 4, wherein the anionic group is a carboxylic acid group or a salt thereof, and / or a sulfonic acid group or a salt thereof.   The insulating member according to claim 4, wherein the block copolymerized polyimide contains an aromatic diaminocarboxylic acid as one of the diamine components.   In the total diamine component, the proportion of the diamine having a siloxane bond in the molecular skeleton is 5 to 90 mol%, and the proportion of the aromatic diaminocarboxylic acid is 10 to 70 mol% (however, the total of both is 100 mol% or less). The insulating member according to claim 9, which may include a third diamine component.   The insulating member according to any one of claims 1 to 10, which is an insulated wire in which an outer periphery of a conductor wire is covered with the insulating layer.   The insulating member according to claim 11, wherein the conductor wire has a rectangular cross-sectional shape.   An insulated coil obtained by winding an insulated wire as an insulating member according to claim 11 or 12 in an edgewise coil manner or an aligned manner.

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