JPH0358121B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a heat-resistant insulated wire, particularly a heat-resistant insulated wire that can be used at high temperatures of 300° C. or higher. Traditionally known heat-resistant enamelled wires include polyimide wire, polyamide-imide wire,
There are polyester imide wires, etc., each starting from 220
It has heat resistance of 250℃, 180~220℃, and 155~180℃, and can be said to have considerable heat resistance, but since they are all made of organic insulation films, they decompose at high temperatures of around 400℃. Therefore, its use was limited to temperatures up to about 250°C. On the other hand, glass windings made by wrapping glass threads around a conductor to insulate them are also known as heat-resistant insulated wires, but such glass windings usually include glass threads and glass threads for the purpose of improving insulation and preventing fraying. An organic insulating paint is applied between the
Therefore, the heat resistance is only around 180℃,
Furthermore, it had the disadvantage of being inferior to Space Factor. In recent years, it has been used for nuclear power generation, geothermal power generation, and other special purposes.
There is a demand for magnet wires that can be used at high temperatures of 300°C or higher, and inorganic wires coated with inorganic materials are being considered, but such inorganic wires are generally porous and have poor flexibility and insulation, making them impractical. The current situation is that it has not been standardized. On the other hand, the present inventors have studied and previously applied for a polyborosiloxane resin that has a skeleton of silicon, boron, and oxygen and can be used as an electrically insulating paint. Although it is fully satisfactory, the sinterability and electrical insulation properties are lowered, and if the degree of sintering is made weaker, the opposite results occur, and so far no enameled wire has been obtained that satisfies all the properties required for an enameled wire. The present inventors have discovered that by mixing an aromatic polyimide resin with the above-mentioned polyborosiloxane resin, an insulated wire can be obtained that can be used even at high temperatures of 300°C or higher without deteriorating its flexibility or insulation properties. However, the present inventors have further discovered that, in addition to this aromatic polyimide resin, heat-resistant resins described below are also effective. The present invention was made based on this knowledge, and includes polyimidazopyrrolones, polyamideimides, polyhydantoins, polyimidazole, polyquinazolone, polyimidazoquinosalines, polysulfones, polyethersulfones, polyoxazoles, polyoxadiazoles, and polyimidazoquinosalines. triazole,
A varnish-like resin solution made by mixing a polyborosiloxane resin or its solution with a solution of one or more heat-resistant resins selected from polyphenylene oxide, polyparabanic acid, and silicone resin is applied directly onto the conductor or otherwise. The present invention relates to a heat-resistant insulated wire characterized in that it is coated and baked through an insulating film. The heat-resistant resins used in the present invention include polyimidazopyrrolone, polyamideimide, polyhydantoin, polyimidazole, polyquinazolone, polyimidazoquinosaline, polysulfone, polyethersulfone, polyoxazole, polyoxadiazole, polytriazole, and polyphenylene. Examples include nylene oxide, polyparabanic acid, and silicone resin, and these may be used alone or in combination. These are usually dissolved in a solvent and are commercially available in the form of varnish, such as polyamide-imide varnish HI400 manufactured by Hitachi Chemical, polyimidazopyrrolone varnish Thermotite H-8 manufactured by Showa Denko Co., Ltd., and silicone resin varnish manufactured by Toshiba Co., Ltd. Manufactured by Silicone
There are TSR116 etc. If the resin itself is commercially available, it can be used after being dissolved in a polar solvent such as N-methylpyrrolidone (NMP) or dimethylacetamide ( _DMAc ). Note that since polyhydantoin is soluble in phenolic solvents such as cresol, it can also be prepared as a cresol solution. The polyborosiloxane resin used in the present invention is
(a) boric acid compounds such as orthoboric acid, metaboric acid, boric anhydride, boric acid methyl ester, borax,
(b) Silane compounds represented by SiX ₄ , SiRX ₃ , SiRR'X ₂ (wherein R and R' are methyl or phenyl groups,
X is a hydroxyl group or chlorine, and in the case where It is obtained by heating the polycondensate at 50 to 800°C to carry out a polycondensation reaction. When the reaction temperature is 300°C or higher, it is preferable to carry out the reaction under an inert atmosphere, and the reaction may be carried out in two stages. In the production of polyborosiloxane resins, it is desirable to use silanol compounds (hydroxysilanes), since the chlorine-containing silane (b) generates hydrogen chloride, which is unfavorable in terms of the working environment. Also, based on the total amount of boric acid compound (a) and silane compound (b),
If 5% by weight or more of silicone oil is added and the polycondensation reaction is carried out, it is desirable to use this method because a wire coating having superior flexibility can be obtained. The viscosity of silicone oil at 25℃ is
Dimethylsilicon or methylphenylsilicon or mixtures thereof of 1.0 centistokes, preferably 10 centistokes or more are suitable. Further, adding a nitrogen-containing compound such as triethanolamine or phenylenediamine to the starting material improves water resistance, and adding hydroquinone, aromatic alcohol, etc. improves the degree of polymerization and water resistance, so it is desirable to use them. In the present invention, a varnish-like resin solution can be obtained by adding and dissolving a polyborosiloxane resin in the heat-resistant resin solution, but since the polyborosiloxane resin is soluble in organic solvents, this can be used as a solution,
It is easier to mix the solutions, and in that case it is preferable to use the same type of solvent. For example, if the solvent for the polyhydantoin resin solution is a phenolic solvent such as cresol, it is desirable to use a phenolic solvent for the polyborosiloxane resin solution, and if the solvent is a polar solvent such as NMP or DMA _c , polyborosiloxane It is also desirable to use NMP or _DMAc as the resin solution. The reason for this is that if different types of solvents are mixed, the solubility of the heat-resistant resin will differ and there is a risk of separation and precipitation. In the present invention, the mixing ratio of the heat-resistant resin solution and the polyborosiloxane resin or resin solution can be appropriately selected depending on the required characteristics. For example, if mechanical properties are not so required but heat resistance is highly required, the proportion of polyborosiloxane resin may be increased, and in the opposite case, the proportion of heat resistant resin may be increased. The preferred ratio is that the polyborosiloxane resin solid content is 30 to 70% of the total resin solid content. The properties of these mixtures in the present invention are not the sum of the individual properties, but are significantly improved by mixing both. When applying and baking the paint thus obtained, it is preferable to perform dry baking after baking under normal conditions or alternately. Next, an example will be described. (Manufacture of polyborosiloxane resin) Diphenyldihydroxysilane 432g (2 mol)
83 g (1.3 mol) of boric acid and 256 g of 10 centistoke dimethyl silicone oil were placed in a reaction vessel equipped with a thermometer, stirrer, and condenser, and the temperature was gradually raised from room temperature to 400°C (6 hours). , and further reacted at 400°C for 2 hours to carry out condensation polymerization. The number average molecular weight of this reaction product was 2500, and the amount remaining after calcination up to 700°C was 55%.
350 g of this product was dissolved in NMP to obtain an NMP solution (No. 1) of polyborosiloxane resin. Also, using 432 g of diphenyldihydroxysilane, 104 g of methyl borate, and 368 g of methylphenyl silicone oil of 100 centistokes, a condensation reaction was performed in the same manner, and the product was dissolved in a mixed solvent of NMP and xylene to form a polyborosiloxane resin. of
An NMP-xylene solution (No. 2) was obtained. Example This polyborosiloxane resin solution and the solution of the heat-resistant resin shown in Table 1 were mixed in the proportions shown in the table, and the resulting varnish-like solution was applied to a 1.0 mmφ Ni-plated copper wire (plating thickness 2μ). An insulated wire with a coating thickness of 30 μm and a good appearance was obtained by coating and baking using a vertical baking machine with a length of 7.2 m under the conditions shown in Table 1. The test results regarding the characteristics of the obtained insulated wire were as shown in Table 1.

【table】

[Table] As is clear from the above examples, the heat softening temperature of the insulated wire according to the present invention is much higher than that of conventional heat-resistant enamelled wire, and it can be used as a super heat-resistant wire.
It can be used at high temperatures of 300℃ or higher and is extremely effective.

Claims (1)

[Claims] 1. Polyimidazopyrrolone, polyamideimide,
Polyhydantoin, polyimidazole, polyquinazolone, polyimidazoquinosaline, polysulfone, polyethersulfone, polyoxazole,
A varnish made by mixing polyborosiloxane resin or its solution with a solution of one or more heat-resistant resins selected from polyoxadiazole, polytriazole, polyphenylene oxide, polyparabanic acid, and silicone resin. A heat-resistant insulated wire characterized by coating and baking a resin solution directly onto a conductor or through another insulating film. 2 Polyborosiloxane resin is silicone oil,
The heat-resistant insulated wire according to claim 1, which is obtained by condensation polymerization of phenyl or methylsilanol and a boric acid compound, with the addition of hydroquinone if necessary.