JPS6328471B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a brazeable insulated wire that has excellent low-temperature brazing properties, crazing resistance, and solvent resistance. Brazeable insulated wires are widely used in fields such as light electrical parts because they can be soldered without removing the coating mechanically or with chemicals. In recent years, there has been a demand for insulated wires that can be soldered at low temperatures and in a short time because the brazing temperature in this field can deteriorate the core wire (copper wire, etc.) or damage the terminal portion to which the ends are bonded. For this reason, the present inventors proposed a brazeable insulated wire made by applying and baking a paint made of lactone polyol and polyisocyanate on a conductor in Japanese Patent Application No. 57-93442, but this method was not possible during the impregnation once. It has become clear that the diluent contained, particularly hydroxyethyl acrylate and hydroxymethacrylate, has the disadvantage of reducing the hardness of the coating film. The present invention improves these drawbacks and consists of (A) 100 parts by weight of a lactone polyol and 10 to 10 parts of a polyester polyol having an aromatic ring and/or a polyether polyol having an aromatic ring.
A composition obtained by blending 800 parts by weight of a polyol component and (B) a stabilized polyisocyanate in a ratio of 0.4 to 2.0 equivalents of isocyanate groups per equivalent of hydroxyl group is applied directly onto the conductor or as an insulating coating. This relates to a brazeable insulated wire that is coated and baked through a wire. The lactone polyol used in the present invention preferably has an average molecular weight of 200 to 100,000, particularly preferably 300 to 2,000, and a hydroxyl value of about 50 to 700. Commercially available products include, for example, Plaxel 305, 303, and 308 manufactured by Daicel. etc. can be mentioned.
Furthermore, as the lactone polyol, one having a hydroxyl value at both ends of the molecule is preferably used. Methods for obtaining lactone polyols from lactones are known, and are described, for example, in Japanese Patent Publication No. 5294-1982 and Japanese Patent Application Laid-open No. 104315-1987. Preferred examples of the lactones used in the present invention include lactones with a ring having 5 or more carbon atoms, preferably 6 or more carbon atoms, or hydrogen atoms of these lactones combined with an alkyl group (having 1 to 10 carbon atoms).
It is converted by . Specifically, α-parerolactone, β-ethyl-
ε-caprolactone, γ-methyl-ε-caprolactone, β・ε-dimethyl-ε-caprolactone, 3,3,5-trimethyl-ε-caprolactone, enantlactone (7-heptanolide), dodecanolactone (1,2- dodecanolide). As a polymerization initiator for polymerizing lactones,
A compound having at least one active hydrogen can be used, and alcohols and amines are practically used. Examples of these include polyhydric alcohols such as ethylene glycol, butanediol, hexanediol, bis(hydroxymethyl)benzene, trimethylolpropane, glycerin, and diamines such as ethylenediamine, phenylenediamine, and triethanolamine. Can be done. In addition, in order to produce lactone polyols from lactones, examples of curing accelerating catalysts that may be used include metal carboxylates, amines (tertiary amines, etc.), phenols, and the like. Specifically, zinc salts, iron salts, copper salts, lead salts, manganese salts, cobalt salts, tin salts, 1.8-
Diazabicyclo(5.4.0) undecene
Examples include 7,2,4,6-tris(dimethylaminomethyl)phenol. Furthermore, the use of this type of curing accelerating catalyst serves to lower the brazing temperature of the resulting insulated wire by allowing the catalyst to remain in the coating composition that is finally obtained. The polyester polyol or polyether polyol having an aromatic ring used in the present invention usually has an average molecular weight of 200 to 10,000 and a hydroxyl value of about 200 to 500, and those having hydroxyl groups at both ends of the molecule are preferably used. be done. This type of polyester polyol or polyether polyol is composed of aromatic polybasic acids such as isophthalic acid, terephthalic acid, orthophthalic acid, phthalic anhydride, aromatic imide acid, aromatic amic acid, trimellitic acid, trimellitic anhydride, and ethylene glycol. Aliphatic polyhydric alcohols such as diethylene glycol, propylene glycol, dipropylene glycol, hexane glycol, butane glycol, glycerin, trimethylolpropane, pentaerytol, and optionally succinic acid, adipic acid, sebacic acid, itaconic acid, and glutaric acid. Synthesis is carried out by a conventional method while using an aliphatic polybasic acid such as aliphatic polybasic acid, but in the present invention, the quantitative proportion of the aromatic compound in the starting material to the total starting material is about 20 to 70% by weight. be done. Examples of commercially available polyester polyols or polyether polyols having aromatic rings include Nipporan 2006 manufactured by Nippon Polyurethane Co., Ltd., Desmohen 600, 800, F-951, 550 manufactured by Bayer Co., Ltd.
1025 etc. can be mentioned. This kind of polyol is lactone polyol 100
10 to 800 parts by weight, preferably 50 to 800 parts by weight
300 parts by weight are used. If it is less than 10 parts by weight, the resulting electric wire will have poor solvent (diluent) resistance, and if it is more than 800 parts, it will have poor brazing properties. Further, as the stabilized isocyanate used in the present invention, toluylene diisocyanate,
The isocyanate group of a polyvalent isocyanate having at least two isocyanate groups in one molecule, such as diphenylmethane diisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate, is replaced with a compound having active hydrogen, e.g. Examples include those blocked with phenols, caprolactam, and methyl ethyl ketone oxime. Further, there may be mentioned one obtained by reacting the polyvalent isocyanate compound with a polyhydric alcohol such as trimethylolpropane, hexanetriol, butanediol, etc., and blocking it with the above-mentioned active hydrogen-containing compound. Examples of these include Nippon Polyurethane Co., Ltd.
Millionate MS-50, Coronate 2501, 2503,
2505, Coronate AP-St, etc. The polyvalent isocyanate has a molecular weight of 300.
It is preferable to use a number of about 10,000. The coating composition used in the present invention has 0.4 to 2.0 equivalents of isocyanate groups in the stabilized isocyanate, preferably 0.9 to 2.0 equivalents, per 1 equivalent of hydroxyl groups in the polyol component.
It can be obtained by adding an appropriate amount of organic solvent (phenols, glycol ethers, naphtha, etc.) in addition to 1.1 equivalents and the required amount of the curing accelerating catalyst to make the solid content usually 40 to 50% by weight. . At this time, appropriate amounts of additives such as appearance improvers and dyes may be added as necessary. In the present invention, the reason why 0.4 to 2.0 equivalents of the isocyanate group of the stabilizing isocyanate is added per 1 hydroxyl group equivalent of the polyol component is that if the amount is less than 0.4 equivalent, the crazing properties of the resulting insulated wire will deteriorate; This is because the abrasion resistance of the insulated wire becomes inferior. The curing accelerating catalyst added when preparing the coating composition is preferably added per 100 parts by weight of the polyol component.
It is 0.1 to 10 parts by weight. If it is less than 0.1 part by weight, the curing accelerating effect tends to decrease and the coating film forming ability tends to deteriorate;
This is because if the amount exceeds 1 part by weight, the thermal deterioration characteristics of the resulting insulated wire will deteriorate. Examples of curing accelerating catalysts include metal carboxylates, amines, and phenols, specifically zinc salts, iron salts, copper salts, manganese salts, and cobalt salts such as naphthenic acid, octenoic acid, and persactic acid. , tin salt, 1,8-diazabicyclo(5.
4.0) Undecene-7, 2.4.6 tris(dimethylaminomethyl)phenol can be exemplified. The brazeable insulated wire of the present invention can be manufactured by applying a coating composition onto a conductor and then baking it in a commonly used baking coating machine. Coating and baking conditions vary depending on the amount of polyol component, stabilized isocyanate, polymerization initiator, and curing accelerating catalyst, but are usually 300~
It can be manufactured by baking at 400°C for about 4 to 100 seconds. In short, baking is carried out at a temperature and for a time sufficient to substantially complete the curing reaction of the coating composition. The brazeable insulated wire obtained by the present invention will be explained below with reference to the drawings. In the drawings, 1 is a copper wire, 2 is a baked film obtained from the coating composition used in the present invention, and 3 is another brazeable insulating film. In the present invention, when a composite film using other brazing insulating films is provided on the conductor as shown in FIGS. 2 and 3, the thickness of the other brazing insulating films is determined by the coating composition used in the present invention. The thickness of the film is about 2 times or less, preferably about 0.5 times or less, than the film thickness obtained from the product. Other materials for forming the brazing insulation film include polyamide resin, special polyester resin,
Examples include special epoxy resins. As described above, the present invention is a brazing insulated wire using a coating composition containing a lactone polyol and a polyester or polyether polyol containing an aromatic ring, so that it can be brazed at low temperatures and has excellent solvent resistance. Become something. The present invention will be explained below based on examples. Parts in the examples are parts by weight. Example 1 50 parts of lactone polyol (manufactured by Daicel, trade name Plaxel 305), 50 parts of polyol having an aromatic ring (Nituporan 2006, manufactured by Nippon Polyurethane)
1 part, 200 parts of stabilized isocyanate (manufactured by Nippon Polyurethane Co., Ltd., trade name MS-50) and lead octylate.
Dissolve 3.0 parts in 400 parts of cresylic acid and remove the nonvolatile content.
A 50% by weight coating composition was obtained. The obtained composition was applied to a 0.5 mmφ copper wire and baked at a wire speed of 45 m/min, passed through a furnace with a furnace temperature of 350°C and a furnace length of 5 m four times to obtain a brazing insulated wire. . The obtained electric wire was evaluated based on JIS C 3211. The evaluation results are listed in Table 1 below. Example 2 50 parts of lactone polyol (manufactured by Daicel, trade name: Plaxel 305), 50 parts of polyol having an aromatic ring (Desmofene 951, manufactured by Bayer), 220 parts of stabilized isocyanate (manufactured by Nippon Polyurethane, trade name: Coronate 2503) and 3.6 parts of cobalt octylate were dissolved in 356 parts of cresylic acid to obtain a coating composition with a nonvolatile content of 50% by weight. An insulated wire was manufactured using the obtained composition in the same manner as in Example 1, and evaluated in the same manner. The evaluation results are listed in Table 1 below. Example 3 50 parts of lactone polyol (trade name Plaxel 305, manufactured by Daicel), 50 parts of polyol having an aromatic ring (Desmofene D-70, manufactured by Bayer), stabilized isocyanate (Millionate MS-50, manufactured by Nippon Polyurethane) 200 parts and lead octylate 2.0
A part was dissolved in cresylic acid to obtain a coating composition with a non-volatile content of 50% by weight. An insulated wire was manufactured using the obtained composition in the same manner as in Example 1, and evaluated in the same manner. The evaluation results are listed in Table 1 below. Comparative example: 100 parts of lactone polyol (manufactured by Daicel Corporation, trade name: Plaxel 303), stabilized polyisocyanate (manufactured by Nippon Polyurethane Co., Ltd., Millionate MS-50)
256 parts of cresylic acid and 3.6 parts of lead octylate
A coating composition having a non-volatile content of 50% by weight was obtained. Using the obtained composition, an insulated wire was manufactured in the same manner as in Example 1, and evaluated in the same manner. The evaluation results are listed in Table 1 below.

[Table] In Table 1, solvent resistance is the value measured by pencil hardness after 48 hours of immersion in HEMA (hydroxyethyl methacrylate) or HEA (hydroxyethyl acrylate). As is clear from Table 1 above, the brazeable insulated wire of the present invention has excellent low-temperature brazeability and solvent resistance.

[Brief explanation of the drawing]

1 to 3 are cross-sectional views of brazeable insulated wires showing practical examples of the present invention. 1... Copper wire, 2... Baked film.

Claims (1)

[Claims] 1 (A) 100 parts by weight of a lactone polyol and a polyester polyol having an aromatic ring and/or a polyether polyol having an aromatic ring 10
A composition obtained by blending a polyol component consisting of ~800 parts by weight and (B) a stabilized polyisocyanate in a ratio of 0.4 to 2.0 equivalents of isocyanate groups per equivalent of hydroxyl group is applied directly onto the conductor or on other insulation. Brazeable insulated wire made by applying and baking a film.