JPH028627B2 - - Google Patents

Description

[Detailed description of the invention]

FIELD OF THE INVENTION The present invention relates to waxy self-adhesive coating compositions. In particular, it relates to a brazing self-melting coating composition that has excellent adhesive strength (fusion strength) at high temperatures (for example, 130°C) and easily provides self-welding insulated wires with excellent brazing properties. be. In recent years, coils for manufacturing electrical equipment have come to be made by winding insulated wire into a predetermined coil shape, impregnating it with varnish, and then heat-treating it to bond and solidify it. Furthermore, in recent years, for the purpose of preventing pollution, safety and hygiene, shortening the manufacturing process, and reducing costs in the production of this type of fused coil, it has become possible to omit the varnish impregnation process and fuse the coils with only heat treatment. .
So-called self-bonding insulated wires have been developed. This type of self-welding insulated wire is widely used in various applications such as deflection yoke coils for televisions, various transformers, and motors. In particular, deflection yoke coils for television are made by winding insulated wire into a yoke coil shape using a self-winding machine.
The material is pressed and heated with electricity to melt the adhesive layer and perform fusion bonding. Conventionally, polyurethane, polyester, etc. have been used for the insulating layer of such self-fusing insulated wires, and polyvinyl butyral, nylon, etc. have been used for the fusing layer, but as the deflection angle tends to increase, heating deformation of the coil It is necessary to reduce the adhesive strength (fusion strength) even at high temperatures (e.g. 130°C).
For reasons such as the need to retain the viscosity, polyester imide has come to be used for the insulating layer, and epoxy resins, phenolic resins, etc. have been used for the fusion layer. Furthermore, recently there has been a demand for cost reduction through rationalization and labor-saving end processing of insulated wires in deflection coils, and a combination of a polyesterimide resin insulating layer and an epoxy resin or phenolic resin fusion layer has become necessary. In this case, terminal processing is extremely difficult. In other words, methods for treating the terminals of insulated wires include (1) mechanical methods, (2) thermal decomposition methods, (3) chemical stripping methods, and (4) solder stripping methods, but currently, the above methods are usually used. For these reasons, I have no choice but to use method (1) to peel off the wire coating before soldering. However, this method is more difficult to strip than a single wire, especially in the case of a deflection yoke coil in which several insulated wires are wound together. In recent years, heat-resistant polyesterimide resin paints have been developed that provide a film that can be directly soldered or soldered, but self-fusing adhesives that are applied as adhesive layers have recently been developed. Regarding paints, although the problem of heat resistance has been resolved, the problem of waxing properties remains unresolved. Therefore, it has been desired to develop a paint that can be directly soldered and that can provide a self-adhesive layer with excellent adhesive strength at high temperatures, that is, a heat-resistant, brazing self-adhesive paint. The present invention has succeeded in developing a brazing self-adhesive coating composition that can satisfy such high demands. That is, firstly, the brazing self-adhesive paint composition of the present invention is a paint made by dissolving a polycarbonate urethane elastomer and a polyester urethane elastomer in an organic solvent. Secondly, the brazing self-adhesive paint composition of the present invention is a paint made by dissolving a polycarbonate-based urethane elastomer, a polyester-based urethane elastomer, a polyvalent isocyanate compound, and a polyhydantoin-based resin in an organic solvent. . The coating composition of the present invention, which is obtained by dissolving a polycarbonate urethane elastomer and a polyester urethane elastomer together in an organic solvent, is coated with a suitable insulating layer, preferably a waxable polyesterimide insulating layer, etc. When applied and baked on an electric wire having an insulating layer, it is possible to easily form a self-brazing layer that has brazing properties and has high adhesive strength even at high temperatures. Furthermore, paints made by dissolving polycarbonate-based urethane elastomer alone in an organic solvent have high adhesive strength at high temperatures, but have poor adhesive strength at low temperatures.
Furthermore, a paint prepared by dissolving a polyester urethane elastomer alone in an organic solvent has a high adhesive strength at low temperatures, but has poor adhesive strength at high temperatures. If a relatively small amount of a polyvalent isocyanate compound and a polyhydantoin resin are further blended into a coating composition containing both urethane elastomers of the present invention, the brazing properties and heat resistance can be further improved. . Various polycarbonate urethane elastomers can be used in the present invention, but
Particularly preferred are terminal NCOs obtained by reacting various polycarbonate diols with various diisocyanates in a ratio such that the molar ratio of the latter's NCO groups to the former's OH groups is about 1 to 1.1.
A linear polycarbonate urethane elastomer with a molecular weight of 10,000 or more. Specific examples include urethane elastomers with a molecular weight of 10,000 or more obtained by the reaction of polycarbonate diol and diphenylmethane diisocyanate. Examples of this type of linear polycarbonate urethane elastomer include Elastran E980, Elastran E990, and Elastran E990.
E998 (all of the above are product names of Nippon Elastolan Co., Ltd.)
etc., such commercially available products can be effectively used in the present invention. Various types of polyester urethane elastomers can be used in the present invention, but particularly preferred ones are those in which various polyester diols and various diisocyanates are used, and the molar ratio of the latter's NCO groups to the former's OH groups is about 0.95 to 1. It is a linear urethane elastomer with a molecular weight of 10,000 or more obtained by reacting at the same ratio. Specific examples thereof include linear polyester urethane elastomers having a molecular weight of 10,000 or more obtained by the reaction of adipic acid polyester diol and diphenylmethane diisocyanate. Such linear polyester urethane elastomers include, for example, paraprene-P22S and paraprene-P22S.
P25S, Paraprene P-26S (all of the above are product names of Nippon Polyurethane Industries), Desmolask-2100
(Sumitomo Bayer product name), Elastolan-E180,
Since it is already commercially available as Elastolan-E190 (all of the above are trade names of Nippon Elastolan Co., Ltd.), such commercial products can be used as appropriate in the present invention. In the coating composition of the present invention, one type each of polycarbonate-based urethane elastomer and polyester-based urethane elastomer may be used, or in some cases, two or more types of each may be used in combination as appropriate. It is.
The usage ratio of both elastomers is the total amount of both 100
The amount of polycarbonate urethane elastomer is usually 5 to 95 parts by weight, preferably 70 to 90 parts by weight.
The amount of the polyester urethane elastomer is usually 95 to 5 parts by weight, preferably 30 to 10 parts by weight. If there is too much polyester urethane elastomer (conversely speaking, if there is too little polycarbonate urethane elastomer), the adhesive strength at high temperatures will decrease, and if there is too little polyester urethane elastomer (conversely speaking, if polycarbonate urethane elastomer is too little), the adhesive strength at high temperatures will decrease. too much elastomer),
Both are unfavorable because the adhesive strength at low temperatures decreases. By blending a polyvalent isocyanate compound and a polyhydantoin resin into a coating composition prepared by dissolving the polycarbonate urethane elastomer and polyester urethane elastomer of the present invention in an organic solvent, the waxing properties and heat resistance of the coating film can be further improved. This can be further improved. Various kinds of polyvalent isocyanate compounds can be used in the present invention. Various diisocyanate compounds, such as toluylene diisocyanate and diphenylmethane diisocyanate, the reaction products of 1 mole of trimethylolpropane and 3 moles of toluylene diisocyanate, and the reaction products of 1 mole of trimethylolpropane and 3 moles of diphenylmethane diisocyanate. Examples include triisocyanate compounds such as reaction products. Such polyvalent isocyanate compounds are used after being masked with phenol, xylenol, or the like. And this kind of polyvalent isocyanate compounds are, for example, Coronate AP Stable, Millionate
Since they are already commercially available as MS-50, Coronate-2503 (both trade names of Nippon Polyurethane Industries, Ltd.), these commercial products can be effectively used in the present invention. The polyhydantoin resin used in the present invention has the general formula (In the formula, X is an oxygen or sulfur atom, and R ¹ and R ² are both

A divalent aromatic group such as [Formula], R ³ represents hydrogen, a methyl group or an ethyl group, and n represents an integer. ) is a linear polymer with a molecular weight of 10,000 or more. Examples of this type of polyhydantoin resin include Registherm-PH10, Registherm-PH20, and Registherm-PH30 (all of the above are Bayer product names).
These types of commercially available products can be used as appropriate in the present invention. The blending ratio of the polyvalent isocyanate compound and the polyhydantoin resin in the present invention is 40 parts by weight or less of the polyvalent isocyanate compound with respect to 100 parts by weight of the total amount of the polycarbonate-based urethane elastomer and the polyester-based urethane elastomer.
Preferably it is 10 to 20 parts by weight, and the polyhydantoin resin is 55 parts by weight or less, preferably 10 to 30 parts by weight. If the proportion of the polyvalent isocyanate compound and polyhydantoin-based resin is too small, the effect of improving brazing properties and heat resistance cannot be expected to be sufficient due to their blending, and on the other hand, if the proportion is too large, the adhesive force will decrease. The polyvalent isocyanate compound and the polyhydantoin resin cannot achieve the above-mentioned effect of improving coating properties unless both are used in combination. That is, if only a polyvalent isocyanate compound is blended, the effect of improving heat resistance will not be noticeable, and if only a polyhydantoin resin is blended, the brazing property will decrease. In addition, both the urethane elastomer and polyhydantoin resin used in the present invention are
As mentioned above, it is desirable that the molecular weight is 10,000 or more. When these molecular weights are less than 10,000, the flexibility of the coating film deteriorates, making it impractical. Various organic solvents can be used in the present invention. Examples include nitrogen-containing polar solvents such as N-methyl-2-pyrrolidone, dimethylformamide, and dimethylacetamide; and phenolic solvents (especially cresol) such as phenol, cresol, and xylenol. The wax-adhesive self-adhesive paint composition of the present invention can easily form a fusion layer by coating and baking onto insulated wires having various wax-adhesive insulating films such as wax-adhesive polyesterimide films. By forming the wire into a coil and then heating it to 140 to 240°C, the fusion layer can be easily softened and fused to firmly fix (adhere) the coil. Furthermore, the baked coating film of the coating composition of the present invention has excellent properties such as flexibility, heat resistance, solvent resistance, brazing properties, and electrical properties, and is particularly excellent in heat resistance and brazing properties. . Next, the present invention will be described in further detail with reference to Examples and Comparative Examples. Parts and percentages in these examples are by weight unless otherwise stated. Example 1 550 parts of cresol was heated to 120°C, and 90% of Elastran-E998 (trade name of Nippon Elastran Co., Ltd.) was added to it.
1 part and 10 parts of Desmolask-2100 (trade name of Sumitomo Bayer AG) were added and stirred for about 3 hours to dissolve, resulting in a concentration of 15.4% (measured value of non-volatile content after heating at 120°C for 3 hours. The same applies hereinafter) and viscosity. 82 poise (B at 30℃
Value measured with a type viscometer. Same below. ) A uniform transparent waxy self-adhesive coating composition was obtained. Next, a commercially available brazing polyesterimide insulation paint (brazing type F polyesterimide TSF-500 manufactured by Totoku Toyo Co., Ltd.) was applied to the copper wire with a wire diameter of 0.45 mm.
Using a horizontal baking furnace with a furnace length of 3 m, the furnace temperature was 450°C.
The wire was baked at a line speed of 23 m/min to obtain an electric wire having an insulating film with a thickness of 20 μm. Next, the coating composition prepared as described above was applied onto the insulated wire in a horizontal baking oven similar to that described above at an oven temperature of 300°C and a line speed of 23°C.
Coating and baking were carried out at a rate of m/min to obtain a brazing self-welding insulated wire having a coating (fusion layer) with a thickness of 15 μm. Example 2 560 parts of cresol, 95 parts of Elastran-E998
The same procedure as in Example 1 was used except that 5 parts of Desmolak-2100 were used, and the concentration was 15.2% and the viscosity was 15.2%.
A uniform transparent waxy self-adhesive coating composition of 83.5 poise was prepared. Using this coating composition, a brazing self-welding insulated wire was produced in the same manner as in Example 1 except for the above. Example 3 510 parts of cresol, 70 parts of Elastran-E998
The same procedure was used as in Example 1, except that 30 parts of Desmolac-2100 were used, and the concentration was 16.4% and the viscosity was 16.4%.
A uniform transparent coating composition of 70.5 poise was prepared. Using this coating composition, a brazing self-welding insulated wire was produced in the same manner as in Example 1 except for the above. Example 4 490 parts of cresol was heated to 120°C, and Elastran-E998 (trade name of Nippon Elastran Co., Ltd.) was added to it.
Add 90 parts of Cresol and 10 parts of Desmolask-2100 (trade name of Sumitomo Bayer), stir for about 2 hours to dissolve, then add 50 parts of cresol, and heat at 90°C.
Add 5 parts of Millionate MS-50 (trade name of Nippon Polyurethane Industries Co., Ltd.) while heating to
Stir for 30 minutes to dissolve, then add Registherm.
Add 17 parts (5 parts as solid content) of PH-20 (trade name of Bayer, a cresol solution of polyhydantoin resin with a solid content of 30%) and stir to dissolve.
A uniform transparent coating composition with a concentration of 16.6% and a viscosity of 87 poise was prepared. An electric wire was obtained in the same manner as in Example 1 except that this coating composition was used. Example 5 568 parts and 50 parts of cresol, elastran
90 parts of E998, 10 parts of Desmolazuk-2100, 15 parts of Millionate MS-50, and Registherm PH
Using 67 parts of -20 (20 parts as solid content),
Otherwise, a uniform transparent coating composition having a concentration of 16.6% and a viscosity of 87 poise was prepared in the same manner as in Example 4. Using this coating composition, a self-welding insulated wire was obtained in the same manner as in Example 1 except for the above. Example 6 760 parts and 50 parts of cresol, elastran
90 parts of E998, 10 parts of Desmolak-2100, 25 parts of Millionate MS-50, Registherm PH-20
117 parts (35 parts as solid content) of each were used, except that the concentration was 19.2% and the viscosity
A uniform transparent coating composition of 72.5 poise was prepared. Using this coating composition, a self-welding insulated wire was obtained in the same manner as in Example 1 except for the above. Example 7 550 parts of cresol, 90 parts of Elastran E990 (trade name of Nippon Elastran Co., Ltd.), Paraprene P22S
(Japan Polyurethane Industries Co., Ltd. trade name) was used in the same manner as in Example 1 except for the concentration.
A uniform transparent coating composition of 15.3% and a viscosity of 85 poise was prepared. Using this coating composition, a brazing self-welding insulated wire was produced in the same manner as in Example 1 except for the above. Comparative Example 1 560 parts of YD-50CS-25B (trade name of Toto Kasei Co., Ltd.), a high molecular weight epoxy resin with a molecular weight of 30,000 or more, was dissolved in 140 parts of cresol to obtain a uniform transparent paint with a concentration of 20% and a viscosity of 22 poise. . This paint was used to form a self-bonding paint layer, and a self-bonding insulated wire was produced in the same manner as in Example 1 except for the above. Comparative Example 2 100 parts of Elastolan E998 was dissolved in 560 parts of cresol to obtain a uniform transparent paint having a concentration of 15.2% and a viscosity of 88 poise. Using this coating composition, a brazing self-welding insulated wire was produced in the same manner as in Example 1 except for the above. Comparative Example 3 130 parts of Desmolac-2100 was dissolved in 520 parts of cresol to obtain a uniform transparent paint having a concentration of 20.1% and a viscosity of 21 poise. Using this coating composition, a brazing self-welding insulated wire was produced in the same manner as in Example 1 except for the above. A solderability test was conducted on each of the electric wires obtained in the above Examples and Comparative Examples. In addition, each of the same electric wires was wound around a round bar with a diameter of 5 mm to a width of about 70 mm to create a helical coil, and the wires were heated at 160°C for 20 minutes to fuse them, and the adhesive strength and heat resistance were measured. The adhesive strength was expressed as the peeling force measured when both ends of the coil were pulled at a speed of 100 mm/min. Heat resistance was expressed as the temperature at which the initial adhesive strength reached half its value. The test results were as shown in the table below.

[Table] As is clear from the results in the above table, the insulated wire obtained using the brazing self-adhesive coating composition of the present invention has excellent brazing properties (solderability), and the adhesive layer is In addition to being able to be soldered directly without removing it, the adhesive layer is highly heat resistant and exhibits high adhesive strength even at temperatures as high as 130°C.

Claims (1)

[Scope of Claims] 1. A brazing self-fusing coating composition comprising a polycarbonate urethane elastomer and a polyester urethane elastomer dissolved in an organic solvent. 2. The polycarbonate-based urethane elastomer is a linear polycarbonate-based urethane elastomer with a molecular weight of 10,000 or more obtained by the reaction of polycarbonate diol and diisocyanate, and the polyester-based urethane elastomer is obtained by the reaction of polyester diol and diisocyanate. The coating composition according to claim 1, which is a linear polyester urethane elastomer having a molecular weight of 10,000 or more. 3. A patent claim in which the blending ratio is 70 to 90 parts by weight of the polycarbonate urethane elastomer and 30 to 10 parts by weight of the polyester urethane elastomer to 100 parts by weight of the total amount of the polycarbonate urethane elastomer and the polyester urethane elastomer. The coating composition according to scope 1 or 2. 4. A brazing self-fusing coating composition prepared by dissolving a polycarbonate-based urethane elastomer, a polyester-based urethane elastomer, a polyvalent isocyanate compound, and a polyhydantoin-based resin in an organic solvent. 5 The polycarbonate-based urethane elastomer is a linear polycarbonate-based urethane elastomer with a molecular weight of 10,000 or more obtained by the reaction of polycarbonate diol and diisocyanate, and the polyester-based urethane elastomer is obtained by the reaction of polyester diol and diisocyanate. The coating composition according to claim 4, which is a linear polyester urethane elastomer having a molecular weight of 10,000 or more. 6 The blending ratio is 70 to 90 parts by weight of polycarbonate urethane elastomer, 30 to 10 parts by weight of polyester urethane elastomer, and polyvalent isocyanate compound to 100 parts by weight of the total amount of polycarbonate urethane elastomer and polyester urethane elastomer. is 10 to 20 parts by weight,
The coating composition according to claim 4 or 5, wherein the polyhydantoin resin is contained in an amount of 10 to 30 parts by weight.