JP5596916B2 - Insulated wire - Google Patents

Description

The present invention relates to insulated wires to form a primer layer with an insulating varnish which is capable of forming an insulating film holding the adhesion to the excellent conductor after high temperature treatment of the varnish impregnation treatment or the like.

  Insulation varnishes mainly composed of polyesterimide resin are used for insulated wires for motor windings and transformer windings that require high heat resistance.

  With the development of automation and high-speed winding process, the requirements for wear resistance, heat resistance, and flexibility for the insulation film of windings are becoming stricter year by year, and further, the output of various electric devices is increased or downsized. As the demand for power saving increases, the space factor increases, and the processing load applied to the windings becomes severe. Under such circumstances, various proposals have been made to improve the abrasion resistance, flexibility and adhesion of the polyesterimide resin insulation coating.

  For example, in Japanese Patent No. 3766447, metal deactivators such as acetylenes, alkynols, aldehydes, amines, mercaptans, and thioureas, phenol resins, urea resins, melamine resins, epoxy resins, silicone resins, etc. It has been proposed to improve the heat resistance of the insulating coating and the adhesion to the conductor by blending the curable resin. And in an Example, the insulation film which added 5-amino- 1,3,4-thiadiazole-2-thiol and the melamine resin to the polyesterimide-type coating material is the adhesive force by a 180 degree peeling test, after a heat shock test It is disclosed that it is excellent in flexibility.

Japanese Patent No. 3766447

  However, in specifications where varnish impregnation is performed, it is not sufficient to improve adhesion at room temperature or flexibility after a heat shock test. Adhesion after heat treatment, softening resistance under high load conditions, etc. must also be satisfied.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an insulated wire having adhesion to a conductor and resistance to softening under high load conditions even after heat treatment. Is to provide.

  The present inventors have proposed an insulated wire using an epoxy resin, in particular a phenoxy resin, as a primer layer as an insulating film that can maintain adhesion with a conductor even after heat treatment (Japanese Patent Application No. 2007-266405). However, as an alternative to the conventional polyesterimide varnish, other characteristics were also examined and the present invention was completed.

That is, the insulated wire of the present invention comprises a base resin of 50 to 99% by mass of a phenoxy resin and 50 to 1% by mass of a polyesterimide resin, and an insulation containing 0 to 50 parts by mass of a curing agent with respect to 100 parts by mass of the phenoxy resin. varnish, applied on a conductor, has a primer layer formed by baking, on to the primer layer, possess one or more layers of top coat layer as the insulating film, the constituent resin of the overcoat layer is different from the said primer layer constituent resin It is. The curing agent is preferably a blocked isocyanate compound, and the thickness of the primer layer is preferably 1 μm or more and 20 μm or less.

  Since the insulating varnish of the present invention uses a blend resin of a phenoxy resin and a polyesterimide resin as a base resin for the coating composition, it has excellent adhesion after high temperature treatment and softening resistance under high load conditions. .

  Although embodiments of the present invention will be described below, it should be considered that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[Insulation varnish]
The insulating varnish of the present invention is characterized in that a blend resin obtained by blending a phenoxy resin and a polyesterimide resin at a specific ratio is used as a base resin.

<Base resin>
The base resin used in the insulating varnish of the present invention is a blend resin of phenoxy resin and polyesterimide resin.
The phenoxy resin refers to an epoxy resin obtained by reacting a bisphenol compound and epihalohydrin in the presence of a strong alkali with a high degree of polymerization.

  Examples of the bisphenol compound include 2,2-bis (4-hydroxyphenyl) methane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) sulfide, 2,2- Bis (4-hydroxyphenyl) sulfone, 3,4,5,6-dibenzo-1,2-oxaphosphane-2-oxide hydroquinone, etc. may be mentioned, and these may be used alone or in combination of two or more. Can do. A suitable representative example of epihalohydrin is epichlorohydrin.

  Suitable phenoxy resins include, for example, bisphenol A modified phenoxy resin produced from bisphenol A and epihalohydrin, bisphenol S modified phenoxy resin produced from bisphenol S and epihalohydrin, and the like. These phenoxy resins are all commercially available compounds, and specific examples include product numbers YP-50, YP50S, YP-55, YP-70, and YPS007A30A manufactured by Tohto Kasei Co., Ltd. However, the present invention is not limited to such examples.

  Although the weight average molecular weight of the phenoxy resin used for this invention is not specifically limited, From a viewpoint of improving heat resistance and adhesiveness, Preferably it is 30000-100000, More preferably, it is 5000-80000.

  The polyesterimide resin is a resin having an ester bond and an imide bond in the molecule, an imide formed from an acid anhydride and an amine, a polyester formed from an alcohol and a carboxylic acid, and a free acid group or an anhydride group of the imide. Is a resin formed by adding to the ester forming reaction. Such a polyesterimide resin can be produced under conditions that cause imidization, esterification, and transesterification.

  The polyesterimide resin used in the varnish of the present invention is a commercial product containing a curing agent, a lubricant, and the like in addition to the polyesterimide resin produced under conditions that cause imidization, esterification, and transesterification as described above. The polyesterimide resin may be used, or a commercially available polyesterimide resin varnish may be used. As commercially available polyesterimide resin varnishes, there are esterimide varnishes such as Isomid 40SM45 manufactured by Hitachi Chemical Co., Ltd., EH402-45, FS304, FS201 manufactured by Dainichi Seika Co., Ltd., Isomid manufactured by Nihon Schechectadi, and Imidex manufactured by General Electric. Can be mentioned.

The base resin of the insulating varnish of the present invention comprises a phenoxy resin and a polyesterimide resin as described above in a ratio of 50:50 to 99: 1, preferably 50:50 to 99, in phenoxy resin: polyesterimide resin (mass ratio). 95: 5, more preferably 75:25 to 95: 5.
This is because as the proportion of the phenoxy resin in the base resin decreases, the adhesion of the insulating coating to the conductor decreases, and when the content of the phenoxy resin is less than 50% by mass, it is difficult to obtain the wear resistance effect of the phenoxy resin. . On the other hand, the phenoxy resin alone has an inferior softening temperature, especially when subjected to a heavy load, as compared to an insulating coating obtained from a general-purpose polyester imide resin varnish. Although this is unsuitable as an insulating coating, this point is eliminated by blending with polyesterimide.

  In addition, what is necessary is just to mix with a phenoxy resin so that solid content in a varnish may become the said ratio, when using a commercially available polyesterimide resin varnish as a polyesterimide resin.

<Curing agent for phenoxy resin>
Since the phenoxy resin has a highly reactive epoxy group or hydroxyl group in the skeleton, it is preferable to coexist with a curing agent that can react with these to form a crosslinked structure.

  As the curing agent for the phenoxy resin, a melamine compound, an isocyanate compound, or the like can be used, but a blocked isocyanate in which the isocyanate group of the isocyanate compound is protected with a blocking agent is preferably used. The blocked isocyanate compound is stable at room temperature, but regenerates a free isocyanate group when heated above its dissociation temperature. The dissociation temperature of isocyanate depends on the type of blocking agent, but is preferably 80 to 160 ° C, more preferably 90 to 130 ° C.

  Examples of the isocyanate compound include aromatic diisocyanates such as tolylene diisocyanate (TDI), p-phenylene diisocyanate, and naphthalene diisocyanate; carbon numbers such as hexamethylene diisocyanate (HDI), 2,2,4-trimethylhexane diisocyanate, and lysine diisocyanate. 3-12 aliphatic diisocyanates; 1,4-cyclohexane diisocyanate (CDI), isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate (hydrogenated MDI), methylcyclohexane diisocyanate, isopropylidene dicyclohexyl-4 , 4'-diisocyanate, 1,3-diisocyanatomelylcyclohexane (hydrogenated XDI), hydrogenated TDI, 2,5-bis (isocyanatome Alicyclic diisocyanates having 5 to 18 carbon atoms such as (l) -bicyclo [2.2.1] heptane, 2,6-bis (isocyanatomethyl) -bicyclo [2.2.1] heptane; (XDI), aliphatic diisocyanates having an aromatic ring such as tetramethylxylylene diisocyanate (TMXDI), and modified products of these diisocyanates.

  Examples of the blocking agent that blocks the isocyanate group of these isocyanate compounds include alcohols, phenols, ε-caprolactam, butyl cellosolves, and the like.

  Commercially available products may be used as the block isocyanate compound, such as Sumitomo Biurethane CT table, BL-3175, TPLS-2759, BL-4165, Nippon Polyurethane Industry MS-50, and the like. .

  It is preferable to use the hardening | curing agent for phenoxy resins in the ratio of 0-50 mass parts per 100 mass parts of phenoxy resins, More preferably, it is 5-30 mass parts.

<Organic solvent>
The insulating varnish of the present invention is obtained by dissolving the above base resin and phenoxy resin curing agent in an organic solvent.
The organic solvent used in the present invention is not particularly limited as long as it can dissolve the base resin. For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, tetramethyl In addition to polar organic solvents such as urea, hexaethyl phosphate triamide, and γ-butyrolactone, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as methyl acetate, ethyl acetate, butyl acetate, and diethyl oxalate Ethers such as diethyl ester, ethylene glycol dimethyl ether, diethylene glycol monomethyl ether, ethylene glycol monobutyl ether (butyl cellosolve), diethylene glycol methyl ether, tetrahydrofuran Hydrocarbon compounds such as hexane, heptane, benzene, toluene, xylene; halogenated hydrocarbon compounds such as dichloromethane and chlorobenzene; phenols such as cresol and chlorophenol; tertiary amines such as pyridine and the like. A solvent can be used individually or in mixture of 2 or more types, respectively.

The organic solvent is usually used so that the solid content in the varnish is about 30 to 60% by mass.
When a commercially available polyesterimide resin varnish is used as the polyesterimide resin, an organic solvent used for the varnish can be substituted.

<Other ingredients>
The insulating varnish of the present invention may contain the following components in addition to the base resin, the phenoxy resin curing agent, and the organic solvent.
For example, a curing agent for polyesterimide may be included. When a commercially available polyesterimide resin or polyesterimide resin varnish is used, an isocyanate curing agent, a methylene compound, a silane coupling agent, a titanate coupling agent, and the like may be contained.

  The insulating varnish of the present invention may further contain various additives such as pigments, dyes, inorganic or organic fillers, lubricants, antioxidants, leveling agents and the like, as long as the purpose of the present invention is not impaired. It may be contained.

<Preparation of insulating varnish>
The insulating varnish of the present invention contains the base resin and the curing agent as described above, and other components added as necessary, and may be prepared by appropriately mixing and stirring each component. Phenoxy resin, phenoxy resin curing agent, and organic solvent are mixed and stirred to prepare a phenoxy resin-curing agent mixed solution, and this phenoxy resin-curing agent mixed solution and ester imide resin (or dissolved in organic solvent) Solution), and further, components added as necessary may be mixed and stirred. By previously mixing the phenoxy resin and the curing agent, it is easy to obtain the wear resistance effect by the cured phenoxy resin.

  The insulating varnish of the present invention not only forms an insulating film with excellent heat resistance, flexibility and abrasion resistance, but also has excellent adhesion to the conductor even under stress, so it can be used for primer layers of insulated wires. It can also be used as a paint.

  The insulating varnish of the present invention can be applied directly to a conductor and then baked and cured to form an insulating coating. The baking temperature is preferably a temperature at which the phenoxy resin can be thermally cured by reacting with the curing agent.

[Insulated wire]
The insulated wire of this invention has a primer layer formed with the hardened | cured material of the said insulating varnish of this invention on the conductor surface.

  As a conductor, it is a well-known conductor normally used for an electric wire conductor, and metal conductors, such as a copper wire and an aluminum wire, are used.

  The insulating varnish of the present invention is preferably carried out by passing it through a furnace at about 350 to 500 ° C. for 10 seconds to 30 seconds per pass (100 seconds to 300 seconds for 10 pulls).

  Although the thickness of a primer layer is not specifically limited, 1-20 micrometers is preferable, More preferably, it is 1-10 micrometers. This is because this thickness is sufficient for the primer layer.

The insulated wire of the present invention has at least one overcoat layer on the primer layer as described above.
The composition of the topcoat layer is not particularly limited, and polyesterimide resin, polyamideimide resin, polyimide resin, polyurethane resin, polyester resin, polyamide resin, phenoxy resin, and the like conventionally used for insulating coatings Can be used. Overcoat layer configuration resins, it becomes different primer layer constituent resin is appropriately selected depending on the use of the insulated wire.

  When the top coat layer is composed of two or more layers, the top coat layer of the insulated wire is preferably composed of a film having lubricity, for example, a highly lubricous polyimide resin or a highly lubricated polyamideimide resin.

  The best mode for carrying out the present invention will be described with reference to examples. The examples are not intended to limit the scope of the invention.

[Measurement evaluation method]
First, the evaluation method performed in this example will be described.

(1) Flexibility The insulated wire was stretched by 20% with respect to the initial length, and after stretching, it was tested according to JIS C3003 7.1.1 flexibility test. Specifically, after winding the electric wire 30 times so that the electric wire and the electric wire are in contact with each other along a round bar having the self-diameter (1d) and double (2d) of the insulated electric wire, the presence or absence of cracks was observed. The diameter (1d or 2d) of the round bar when no crack occurred was examined. If no crack occurs even in 1d, it can be said that the flexibility is excellent.

(2) Heat shock test The insulated wire was stretched by 20% with respect to the initial length, and after stretching, it was tested according to the impact resistance test of JIS C3003-20. Specifically, after heating at 200 ° C. for 30 minutes, the electric wire is wound 30 times so that the electric wire and the electric wire are in contact with each other along a round bar having a self-diameter (1d) and twice (2d) of the insulated electric wire. After that, the presence or absence of cracks was observed, and the diameter of the round bar when no cracks occurred was examined. It means that the smaller the diameter of the round bar is, the higher the heat resistance is, the higher the heat resistance, and the better the heat resistance.

(3) Wear resistance The unidirectional wear value (g) was measured in accordance with the wear resistance test described in JIS C3003-1999. This is an investigation of how much force is applied to break the coating, and it is an index of coating strength against stress during shoreline.
In addition, about each insulated wire, the average value of the result of having measured 9 pieces is shown.

(4) Adhesiveness According to JIS-C3003 “8.1a) rapid extension”, film floating (average value when measured at two locations) was measured.
The measurement was performed after standing at room temperature at 160 ° C. for 6 hours and after standing at 180 ° C. for 6 hours.

(5) Softening temperature The softening temperature (° C.) was measured according to JIS C3003 “Test method for enameled copper wire and enameled aluminum wire”. For each of a load (700 g) and a double load (1400 g) specified in JIS, the temperature (softening temperature) when the wire was conducted was measured.
In addition, about each insulated wire, the average value of the maximum value and the minimum value of the result of measuring four each is shown.

[Insulating varnish preparation solution]
(1) Phenoxy resin solution A bisphenol A-type phenoxy resin ("YP-50" manufactured by Tohto Kasei Co., Ltd.) obtained by reacting bisphenol A and epichlorohydrin is dissolved in cresol to prepare a phenoxy resin content 30% by mass solution. did.

(2) General-purpose esterimide resin solution “Isomid40SM45” (solid content: 45% by mass), which is an ester imide varnish made by Hitachi Chemical Co., was diluted with cresol to prepare a general-purpose esterimide resin content of 30% by mass. .
(3) Highly Adhesive Esterimide Resin Solution “EH402 No. 3-45” (solid content: 45% by mass), which is an ester imide varnish manufactured by Dainichi Seika Co., Ltd., is diluted with cresol, and the ester imide resin content is 30%. % Solution was prepared.

(4) Curing Agent Solution A block isocyanate “MS50” manufactured by Nippon Polyurethane Co., Ltd. was dissolved in cresol as a curing agent to prepare a 30% by mass curing agent content solution.

[Insulated wire No. Preparation of 1]
100 parts by mass of the phenoxy resin solution and 20 parts by mass of the curing agent solution were mixed and stirred at room temperature for 1 hour to obtain insulating varnish No. 1 was produced. This insulating varnish was applied to a copper wire having a diameter of 1.0 mm and baked to form a 3 μm primer layer (first layer).
Next, general-purpose ester imide varnish (“Isomid40SM45”, an ester imide varnish manufactured by Hitachi Chemical), general-purpose polyamide-imide varnish (“HI-406E-34” manufactured by Hitachi Chemical), self-lubricating polyamide-imide varnish (Sumitomo Electric Wintech) Co., Ltd.) were sequentially applied to form an insulating film having a thickness of 35 μm having a four-layer structure including a second layer (25 μm), a third layer (5 μm), and a fourth layer (2 μm).
About the produced insulated wire, flexibility, a heat shock test, abrasion resistance, adhesiveness, and softening temperature were measured based on the said evaluation method. The results are shown in Table 1.

[Insulated wire No. Production of 2-8]
No. Insulating varnish (containing 20 parts by mass of curing agent with respect to 100 parts by mass of phenoxy resin) and a general-purpose esterimide resin solution mixed in the ratio shown in Table 1 and stirred for 1 hour at room temperature. 2-8 were prepared. Using each of the prepared insulating varnishes, no. In the same manner as in No. 1, an electric wire having an insulating film with a film thickness of 35 μm having a four-layer structure was prepared, and the flexibility, heat shock test, wear resistance, adhesion, and softening temperature were measured based on the above evaluation methods. The results are shown in Table 1.

[Insulated wire No. Production of 9-11]
80 parts by mass of a phenoxy resin solution and 20 parts by mass of a general-purpose esterimide resin solution were mixed and stirred at room temperature for 1 hour to obtain insulating varnish No. 9 was prepared. Using each of the prepared insulating varnishes, no. In the same manner as in No. 1, an insulated wire having a four-layer structure and an insulating film having a thickness of 35 μm was produced.
Insulated wire No. For Nos. 10 and 11, a general-purpose polyesterimide resin solution and a highly adhesive polyesterimide solution were used, respectively. In the same manner as in No. 1, an insulated wire having a four-layer structure and an insulating film having a thickness of 35 μm was produced.

  For each insulated wire, flexibility, heat shock test, abrasion resistance, adhesion, and softening temperature were measured based on the above evaluation methods. The results are shown in Table 1.

  As can be seen from Table 1, insulated wire No. 1 having a primer layer made of general-purpose polyesterimide. No. 10, in the flexibility and heat shock test, the adhesion with the self-diameter (1d) could not be satisfied, and the wear resistance was insufficient. Insulated wire No. 1 having a primer layer made of highly adhesive polyesterimide In No. 11, in the flexibility and heat shock test, the adhesion at the self-diameter (1d) could be satisfied, and the wear resistance was also improved. However, the film floating after high temperature treatment is large, and it is unsuitable as an insulated wire used under varnish impregnation treatment or high temperature conditions. On the other hand, an insulated wire No. 1 using an insulating varnish using a phenoxy resin alone as a base resin. No. 1 was able to improve the flexibility, heat shock characteristics, and wear resistance while maintaining the same level of properties as general-purpose ester imide for adhesion after high temperature treatment. ) The softening temperature at the bottom is greatly reduced.

  However, an insulated wire No. 1 using a blend resin of a phenoxy resin and a general-purpose polyesterimide resin as a base resin. In Nos. 2 to 9, even if the flexibility, heat shock characteristics, and wear resistance were improved, no significant decrease in other characteristics was observed, including a decrease in film floating after high-temperature treatment. From these, it can be seen that a blend resin of a polyesterimide resin and a phenoxy resin is useful as the base resin.

  However, when using a blend of polyesterimide resin and phenoxy resin, if the content ratio of the polyesterimide resin becomes too large, the wear resistance and the adhesion after high temperature treatment tend to decrease, so the polyesterimide resin in the base resin Is preferably 50% by mass or less, more specifically 25% by mass or less.

  No. 5 and No. From the comparison with 9, the effect of improving the wear resistance was slightly higher when the phenoxy resin curing agent was added.

  Since the insulating varnish of the present invention uses a blend resin of a phenoxy resin and a polyesterimide resin as a base resin, a film of an insulated wire that requires mechanical properties such as adhesion after high-temperature treatment such as varnish impregnation treatment In particular, it is useful for forming a primer layer.

Claims (3)

A base resin of 50 to 99% by mass of a phenoxy resin and 50 to 1% by mass of a polyesterimide resin, and an insulating varnish containing 0 to 50 parts by mass of a curing agent with respect to 100 parts by mass of the phenoxy resin are applied and baked on the conductor. Having a primer layer
On the primer layer, possess one or more layers of top coat layer as an insulating film, the constituent resin of the overcoat layer is different from the primer layer constituent resin insulated wire. The insulated wire according to claim 1, wherein the curing agent is a blocked isocyanate compound. The insulated wire according to claim 1 or 2, wherein the primer layer has a thickness of 1 µm or more and 20 µm or less.