JP2801189B2 - Heat resistant electrical insulation paint - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a heat-resistant electrically insulating paint having excellent soldering properties. (Prior art) Recently, insulated wires used for motors, transformers, deflection yokes, etc., have become increasingly thinner and used in extremely harsh atmospheres as electronic and electrical devices become smaller, lighter and more sophisticated. For this reason, the heat resistance of the resin material for forming the film of the electric wire is more required than before. On the other hand, in performing soldering work as a terminal treatment of the insulated wire, in order to save labor or adverse effects on other components due to heat and to reduce the diameter of the insulated wire itself,
There is an increasing need for self-brazing materials that can be soldered directly at low temperatures and for short periods of time. That is, they must have both contradictory characteristics that they have excellent heat resistance as a self-brazing material and can be soldered at a low temperature. At present, the mainstream of this type of insulated wire is polyurethane wire, whose heat resistance grade is E class (120 ° C.), and the soldering temperature is 360 ° C.
380 ° C, 1-2 seconds. Further, in order to further improve the heat resistance, as the esterimide-modified polyurethane electric wire, the heat resistance grade is B class level (130 class).
℃), soldering temperature 380-420 ℃, consisting of several seconds,
And heat-resistant grade F as polyesterimide wire
At the seed level (155 ° C), soldering temperatures of 440-460 ° C, several seconds have emerged. However, these insulated wires have not been able to satisfy the needs of electrical equipment manufacturers. For example, 0.
For insulated wires of 05mmφ or less, soldering temperature 400 ℃
In this case, the conductor melts, cuts or disappears within a few seconds after the solder is attached. Therefore, there is a demand for a small-diameter insulated wire having a heat resistance of at least 400 ° C. and within a few seconds when used for parts requiring heat resistance. (Problems to be Solved by the Invention) The present invention has conducted intensive research in response to such a demand, and as a result, has maintained a heat-resistant grade F class and has a soldering temperature of 360 to 400.
The present invention has developed a heat-resistant electrical insulating paint having an epoch-making characteristic of 1 to 2 seconds or less. (Means for Solving the Problems) The heat-resistant electrically insulating coating material of the present invention comprises (I) an average molecular weight of 40
One or more resins selected from the group consisting of a polyamide imide resin, a polyester amide imide resin, and a polyester imide resin having a glass transition temperature of 180 to 320 ° C.
And (II) one or two or more oligomers selected from ester imide oligomers, ester amide imide oligomers and ester amide oligomers having an average molecular weight of 230 to 1800 and having a hydroxyl group at the terminal. ~
45% by weight and (III) stabilized isocyanate compound 12 to 8
It is characterized in that a mixture with 0% by weight is dissolved in a solvent. In the present invention, the resin (I) has a heat resistance grade of Class H or higher. However, when the average molecular weight (hereinafter, also simply referred to as molecular weight) is less than 4,000, the thermal characteristics deteriorate, and the molecular weight is reduced. Limited to 4000 or more. The reason for limiting the glass transition temperature to 180 to 320 ° C is that
If the temperature is lower than ℃, the thermal characteristics are significantly reduced,
On the other hand, if the temperature exceeds 320 ° C., no solder characteristics can be exhibited at all. Furthermore, the reason for limiting the blending amount to 10 to 80% by weight is that if the amount is less than 10% by weight, the thermal characteristics are remarkably deteriorated, and if it exceeds 80% by weight, the soldering characteristics are hardly exhibited. This is because, when the insulated wire is not obtained, the appearance of the surface is poor.
The preferred range is 30 to 70% by weight. In order to produce this high-molecular-weight resin, for example, a polyamideimide resin is obtained by reacting at least one tricarboxylic anhydride with at least one diisocyanate. There is a brand name HI-405 (average molecular weight of 40,000 or more, glass transition temperature 250 ° C.) manufactured by the company. The polyester amide imide resin is obtained by reacting at least one kind of tricarboxylic anhydride, polyvalent amine, dicarboxylic acid, and polyhydric alcohol, and commercially available products thereof are trade names of Dainichi Seika Co., Ltd. Terebe
c800 (average molecular weight 10,000, glass transition temperature 220 ° C). The polyesterimide resin is obtained by reacting at least one kind of tricarboxylic anhydride, diisocyanate, and polyhydric alcohol, and commercially available products include Isomid RL manufactured by Nisshin Schenectady Company.
(Average molecular weight 20,000, glass transition temperature 190 ° C). Next, the oligomer of (II) has a molecular weight of 230-180.
The reason for limiting to 0 is that the molecular weight of 230 is the lowest, and if the average molecular weight exceeds 1800, the soldering properties are significantly reduced. A preferred range is a molecular weight of 600 to 1300. Further, the reason for limiting the compounding amount to 4 to 45% by weight is that when the amount is outside this range, the soldering properties are all poor. Among these oligomers, ester imide oligomers are:
It is obtained by reacting at least one kind of tricarboxylic anhydride, diamine, and polyhydric alcohol. The ester amide oligomer is obtained by reacting at least one kind of dicarboxylic acid, polyvalent isocyanate, and polyhydric alcohol. The ester amide imide oligomer is obtained by reacting at least one kind of tricarboxylic anhydride, diisocyanate, dicarboxylic acid, and polyhydric alcohol. Next, the stabilized isocyanate compound (III) is obtained by stabilizing the isocyanate group of at least one kind of polyvalent isocyanate with a polyhydric alcohol or a phenol. There are AP Stable, Coronate 2503, Millionate MS-50. The reason why the amount of the stabilized isocyanate compound is limited to 12 to 80% by weight is that, when the amount is outside the above range, the soldering characteristics deteriorate. In the present invention, as a solvent for the mixture of (I), (II) and (III), phenols, DMF (dimethylformamide), N-methylpyrrolidone, and the like are preferable, and the mixture concentration is 5 to 60% by weight. Is preferable. In addition, a polyamide resin, an epoxy resin, a silicone resin, a phenol resin, or the like can be used in combination as long as the effects of the present invention are not reduced. The methods for evaluating the physical properties are shown below. Glass transition temperature-TBA (Torsion braid analysis) used (Tg) Sample preparation: Glass fiber braid impregnated with 30% resin concentration and dried Detection: Calculated from peak value of logarithmic decay rate Average molecular weight-GPC (gel permeation chromatography) Graph) Use (weight average molecular weight) Detector: UV (ultraviolet) Calibration curve: polystyrene conversion Sample preparation: resin concentration 0.5%, solvent DMF (Example) Example 1 Trimellitic anhydride (0.86 mol) 165 g, diaminodiphenylmethane 85 g of (0.43 mol), 115 g of trimethylolpropane (0.86 mol) and 1000 g of N-methylpyrrolidone as a solvent are placed in a flask of 2, and the contents are heated to 80 ° C. and dissolved. In this case, when the temperature rises to 90 ° C, it solidifies rapidly,
It melts again when the temperature is raised to ° C. Further, the temperature is raised to 230 ° C., and when the amount of dehydration reaches 95 to 100%, heating is stopped and cooling is performed. At this time, the average molecular weight of the ester imide oligomer was 580. 100 ℃
When the following conditions were reached, 500 g of naphtha and 250 g of trade name MS-50 manufactured by Nippon Polyurethane Co. were added and dissolved to obtain 2000 g of a 25% solution of esterimide oligomer. Next, this oligomer solution was added to Hitachi Chemical Co., Ltd.
2000 g of a 25% solution of 405 was added and mixed to obtain an insulating paint of the present invention. Example 2 3200 g of a 25% solution of HI-405 (trade name, manufactured by Hitachi Chemical Co., Ltd.) was added to 800 g of a 25% solution of the ester imide oligomer obtained in Example 1.
The mixture was added and mixed to obtain the insulating paint of the present invention. Example 3 101 g of trimellitic anhydride (0.52 mol), 44 g of terephthalic acid (0.26 mol), 132 g of diphenylmethane diisocyanate (0.52 mol), and 1075 g of solvent cresol were put into 3 flasks, and the temperature of the contents was increased to 80 ° C. To dissolve. When the temperature rises to 90 ° C, it rapidly solidifies, but when the temperature rises to 200 ° C, it melts again. At this time, slowly add 72 g of pentaerythritol (0.52 mol), and the dehydration amount is 95-100%
When the temperature reaches, heating is stopped and cooling is performed. At this time, the average molecular weight of the ester amide imide oligomer was 1,100. When the temperature reached 100 ° C. or lower, 1075 g of naphtha and 614 g of Coronate 2503 (trade name, manufactured by Nippon Polyurethane Co., Ltd.) were added and dissolved to obtain 3070 g of a 30% solution of ester amide imide oligomer. Next, this oligomer solution was added to Dainichi Seika's trade name Tere.
930 g of a 36% solution of bec800 was added and mixed to obtain an insulating paint of the present invention. Example 4 2160 g of a 30% solution of an ester amide imide oligomer produced in the same manner as in Example 3 was added to Tereb, trade name of Dainichi Seika Co., Ltd.
1840 g of a 36% solution of ec800 was added and mixed to obtain an insulating paint of the present invention. Example 5 116 g of terephthalic acid (0.70 mol), 92 g of diaminodiphenylmethane (0.47 mol), 43 g of glycerin (0.47 mol),
After adding 658 g of the solvent cresol to the three flasks, the content temperature is raised to 80 ° C. to dissolve. In addition, 90
When the temperature rises to ℃, it suddenly becomes highly viscous. However, the temperature is gradually raised to 230 ° C, and when the amount of dehydration reaches 95 to 100%, heating is stopped and cooling is performed. At this time, the average molecular weight of the ester amide oligomer was 960. When the temperature reached 100 ° C. or lower, 658 g of naphtha and 338 g of Coronate AP Stable manufactured by Nippon Polyurethane were added to obtain 1880 g of a 30% solution of ester amide oligomer. Next, 2120 g of a 27% solution of Isomid RL manufactured by Nisshin Schenectady Co., Ltd. was added to the oligomer solution and mixed to obtain an insulating coating of the present invention. Example 6 Terebec 800, a 36% solution from Dainichi Seika Co., Ltd. was added to 2180 g of a 30% solution of an ester amide oligomer prepared in the same manner as in Example 5.
820 g was added and mixed to obtain an insulating paint of the present invention. Comparative Examples 1-4 A 25% solution of HI-405 (trade name, manufactured by Hitachi Chemical Co., Ltd.) (Comparative Example 1), Isomid RL 27% (trade name, manufactured by Nisshin Schenectady)
A solution (Comparative Example 2), a 25% solution of the ester imide oligomer prepared in the same manner as in Example 1 (Comparative Example 3), and 340 g of a 30% solution of the ester amide imide oligomer prepared in the same manner as Example 3 4660 g of a 36% solution of Terebec 800 manufactured by Kakesha was added and mixed to obtain insulating coatings (Comparative Example 4). With respect to the electric insulating paint of the present invention and the comparative insulating paint thus obtained, respective insulated wires were produced under the conditions shown in Table 1 and the performance was measured. The mixing ratios in the examples and comparative examples are as shown in Table 2. Each characteristic was examined as follows. Appearance of electric wire: The presence or absence of the foaming state of the film when the electric insulating paint was applied to the conductor and baked was confirmed and judged by touch. Foam sample 10
The case of 0 pieces for 00m was regarded as good. Pinhole characteristics: No elongation-A 5 m sample was immersed in phenolphthalein-containing saline and applied with 12 V to investigate the number of defects. 3% elongation—After elongating the sample 5m by 3%, the number of defects was examined in the same manner as described above. The smaller the number of defects per 5 m, the better. Soldering characteristics: Immerse about 40mm end of insulated wire in molten solder,
The solder temperature at which the solder uniformly adheres to a portion of 30 mm or more in 2 seconds was investigated. The lower the solder temperature, the better the solder characteristics. Dielectric breakdown voltage: The breakdown voltage at that time was measured in accordance with the two-strand method specified in JIS C 3003. In addition, the measurement was also performed after the two-twisted sample was deteriorated at 240 ° C. for 168 hours, and the value after the deterioration was defined as the residual ratio by the value before the deterioration. The larger the value, the better the insulation and heat resistance. The above results are collectively shown in Table 3. In thermosetting resins, polyamideimide is HI
-405, and Tereb as polyester amide imide
Using ec800, polyesterimide is Isomid RL
Was used. In addition, trade names of coronate are shown for the stabilized isocyanate. As is clear from the above table, it was confirmed that the insulated wire made of the insulating paint of the present invention was excellent in solderability and electrical properties. (Effect of the Invention) As described in detail above, according to the heat-resistant electric insulating paint of the present invention, the insulated wire obtained from the paint has heat resistance excellent in solderability, so that it is extremely applicable to electronic and electric equipment. Useful.

Continuation of front page (56) References JP-A-53-130750 (JP, A) JP-A-62-58519 (JP, A) JP-A-53-123437 (JP, A) (58) Fields investigated (Int .Cl. ⁶ , DB name) C09D 5/25 C09D 175/00 H01B 3/30

Claims (1)

(57) [Claims] (I) average molecular weight 4000 or more, glass transition temperature 180-3
One or more resins selected from the group consisting of a polyamide imide resin, a polyester amide imide resin, and a polyester imide resin at 20 ° C, 10 to 80% by weight, and (II) having an average molecular weight of 230 to 1800, Of one or more oligomers selected from among ester imide oligomers, ester amide imide oligomers and ester amide oligomers having the formula (I) and 4 to 45% by weight of (III) 12 to 80% by weight of the stabilized isocyanate compound A heat-resistant electric insulating paint characterized by being obtained by dissolving a substance in a solvent.