JPS6227489B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an impedance device formed by filling and curing a resin mixture in the gap between a case and an impedance element, and particularly to an impedance device that emits significantly less odor during curing and has excellent heat dissipation and humming sound absorption characteristics. In impedance devices used in discharge lamp ballasts, power transformers, etc., an unsaturated polyester or epoxy resin mixture is generally filled and hardened in the gap between the case and the impedance element.
The main purpose of filling and curing the resin mixture is to efficiently dissipate heat generated due to the operation of the impedance element and absorb humming noise, in addition to preventing electrical insulation from absorbing moisture. Unsaturated polyester resin mixtures, which have been commonly used for filling and curing, use a polyester resin condensate of polybasic acid and polyhydric alcohol as a vehicle, a styrene derivative as a reactive diluent, and an inorganic It is a mixture of fillers.
However, the reactive diluent volatilizes during the heat curing process, which not only significantly impairs workability but also causes environmental pollution such as bad odors and air pollution. Compared to unsaturated polyesters, epoxy resin mixtures have less odor and have superior resin properties. However, as is well known, this has the drawback of being toxic to the skin and causing rashes on the hands during work. Therefore, the present invention solves the problems of bad odor and air pollution caused by the volatilization of reactive diluents, which are the disadvantages of polyester resin mixtures used in conventional impedance devices, and also solves the problems of odor and air pollution caused by the volatilization of reactive diluents. The present invention aims to provide an impedance device that does not cause any problems with performance and can exhibit excellent effects in terms of heat dissipation and humming sound absorption characteristics. For this purpose, the present invention involves reacting a dibasic acid, a polyhydric alcohol, and a vegetable oil fatty acid to form a polyester precondensate having an acid value of 40 or more and a hydroxyl value of 5 or less, and then giving the precondensate an unsaturated polyester having a glycidyl group. An impedance in which a curable resin mixture consisting of a resin composition and an inorganic filler made by reacting monomers and containing no reactive diluent or a small amount of reactive diluent and an inorganic filler is housed in the case. This is an impedance device formed by filling and hardening the gap between the element and the element. Next, the details will be explained separately for the curable resin mixture and its filling and curing. [] Curable resin mixture A combination of dibasic acid, polyhydric alcohol, and vegetable oil fatty acid, which are the raw materials for polyester precondensate, undergoes a heating condensation reaction to yield a precondensate with an acid value of 40 or more and a hydroxyl value of 5 or less. In other words, it is blended so that the acid group remains. Dibasic acids are α, β unsaturated dicarboxylic acids or their anhydrides, or aromatic, cycloaliphatic or saturated aliphatic dicarboxylic acids or their anhydrides, examples being maleic anhydride, fumaric acid, itaconic acid. , isophthalic acid, terephthalic acid, tetrahydrophthalic acid, adipic acid, sebacic acid, succinic acid, and the like. Next, examples of polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1.6-
Hexanediol, glycerin, trimethylolpropane, pentaerythritol, etc. Furthermore, vegetable oil fatty acids have the effect of lowering the viscosity of the resin and increasing the flexibility of the cured resin mixture; examples thereof include soybean oil fatty acids,
The main ones include linseed oil fatty acid, olive oil fatty acid, coconut oil fatty acid, tall oil fatty acid, and rice bran oil fatty acid. The above-mentioned dibasic acids, polyhydric alcohols, and vegetable oil fatty acids can each be used alone or in combination of two or more. Further, for the reaction, conditions commonly used in polyester condensation reactions can be employed. The end point of the reaction is the point where the acid value is 40 or more and the hydroxyl value is 5 or less. If the esterification reaction progresses sufficiently, the hydroxyl value will be 5 or less, and since it was blended so that acid groups remain, then the acid value will be 40 or more. If the acid value is less than 40, the amount of unsaturated monomers with glycidyl groups that can react with the remaining acid groups will be small, resulting in a lack of unsaturated groups and a reactive diluent that will cause odor. This means that a large amount must be used for polymerization. The amount of the unsaturated monomer having a glycidyl group to be reacted with the above polyester resin precondensate is such that the remaining acid group and the glycidyl group are equivalent, and the end point of the reaction is the point at which the acid value becomes 7 or less. It is. The reaction is then allowed to proceed at a temperature of 80-120°C. At this time, it is preferable to add hydroquinone or a homolog or derivative thereof and a tertiary amine to control the reaction. By reacting unsaturated monomers having glycidyl groups, the unsaturated groups are incorporated into the resin structure and also serve to improve the adhesion of the resin mixture. Main examples of the monomer having a glycidyl group include methacrylic acid glycidyl ester, acrylic acid glycidyl ester, allyl glycidyl ether, and the like. The above-mentioned curable resin composition having an unsaturated group can be polymerized by itself without adding a reactive diluent, and since the viscosity of the resin is low due to vegetable oil fatty acid modification, it can be used without adding any reactive diluent. However, in order to further improve the filling workability, it may be diluted with a small amount of a reactive diluent if necessary. The reactive diluent added in this case may be one or more acrylic ester or styrene compounds. Regarding the amount of reactive diluent to be added as necessary, it is best not to use styrene compounds due to their odor, but since the viscosity of the resin composition in the present invention is low, even if they are used, it is necessary to A small amount of less than % by weight is sufficient, and in that case, the odor is not perceivable. On the other hand, acrylic ester compounds have low volatility, so they
It can be added if it is less than 50% by weight. Specific examples of reactive diluents include 2-hydroxyethyl methacrylate, methacrylic acid-
acrylic esters such as lauryl, and acrylic ester substituted derivatives such as dibutyl maleate, dioctyl maleate, dibutyl fumarate, dioctyl fumarate, dibutyl itaconate, and styrene, vinyltoluene, α-methylstyrene, Styrene derivatives such as chlorstyrene. In addition, the inorganic filler is effective in increasing the heat dissipation of the impedance device.
Practically, silica powder, fluorite, silica sand, talc,
Clay, glass powder, mica powder, calcium carbonate powder, antimony trioxide, etc. are preferred. This inorganic filler can be added to 60% by weight or more of the resin mixture. In addition, methyl ethyl ketone peroxide,
A curing agent typified by a peroxide such as benzoyl peroxide, and a curing accelerator such as a cobalt-based or amine-based compound are used in addition. [] Filling and curing of a curable resin mixture To fill and harden a resin mixture in an impedance device, the above-mentioned curing agent, curing accelerator, and inorganic filler are mixed with the above-mentioned resin composition prepared in advance. , prepare a flowable resin blend. The prepared resin mixture is injected into the gap between the case and the impedance element and cured at a temperature of 25 to 120°C. 1 and 2 show a specific example of the impedance device of the present invention, 1 is a case, 2 is an impedance element housed in the case 1,
This element 2 has a structure in which a coil 4 is wound around a magnetic core 3. 5 is a resin mixture filled and hardened in the gap between the case and the impedance element. According to the present invention, the resin mixture does not use a reactive diluent or only requires a small amount of reactive diluent, and its volatilization is extremely small, so the odor when the resin mixture is cured is significantly reduced, and workability is dramatically improved. improved. Therefore, pollution problems such as bad odors and air pollution can be avoided. Further, according to the present invention, since the resin mixture is modified with vegetable oil fatty acids, the resin mixture exhibits a rubber-like appearance after hardening, is flexible, and has excellent sound absorption properties, and is especially made of unsaturated monomers having a glycidyl group. , it has excellent adhesion to impedance elements and the inner surface of the case, and has good thermal conductivity. Therefore, it is possible to provide an impedance device with less humming noise and excellent heat dissipation. Although the present invention has been described above based on an application example of a ballast for a discharge lamp, the impedance device of the present invention can be applied to a wide range of electrical equipment including small transformers. This will be explained below with reference to examples. In addition, parts in Examples indicate parts by weight. Example 1 127 parts of phthalic anhydride, 131 parts of pentaerythritol
160 parts and 726 parts of soybean oil fatty acid were charged into a reactor.
Proceed with the esterification reaction at ~200℃, and when the acid value is 52 and the hydroxyl value is 5 or less, perform dehydration under reduced pressure. After cooling, when the temperature inside the flask reaches 120℃, add 0.02 parts of hydroquinone and 5 parts of tertiary amine. Then, 123 parts of glycidyl methacrylate was gradually added dropwise and reacted at a reaction temperature of 100°C until the acid value of the resin was 5.
A resin composition was obtained. Cobalt naphthenate 6 was added to 100 parts of this resin composition.
0.4 parts of % solution and methyl ethyl ketone peroxide
Add 1.0 part and mix well, add 200 parts to this mixture solution.
Add 250 parts of Metsuyu silica powder and stir well.
Leave it as it is for 10 to 15 minutes to obtain a resin mixture. Next, this resin mixture was poured into a case containing an impedance element and heated at 80° C. for about 1 hour. As a result, the resin mixture hardens into a rubbery state,
We were able to obtain a highly flexible impedance device. Example 2 126 parts of adipic acid, 255 parts of phthalic anhydride, 263 parts of pentaerythritol, and 968 parts of wood bran oil fatty acid were charged into a reactor, and an esterification reaction was carried out at 160 to 200°C to obtain an acid value of 65 and a hydroxyl value of 5 or less. At that point, dehydration is performed under reduced pressure, and after cooling, the temperature inside the flask is
When the temperature reaches 120°C, add 0.3 parts of hydroquinone and 8 parts of tertiary amine, and add 245 parts of glycidyl methacrylate.
The mixture was gradually added dropwise to react at a reaction temperature of 100°C to obtain a reactant having a resin acid value of 5. This reaction product was diluted by adding 464 parts of 2-hydroxyethyl methacrylate to obtain a resin composition. Cobalt naphthenate 6 was added to 100 parts of this resin composition.
0.4 parts of % solution and methyl ethyl ketone peroxide
Add 1.0 part and mix well, add 250 parts of 200 mesh silica powder to this mixture, stir well, and leave for 10 to 15 minutes to obtain a resin mixture. Next, this resin mixture was injected into a case containing an impedance element and heated at 80°C for 1 hour. This made it possible to obtain a highly flexible impedance device. Example 3 49 parts of maleic anhydride, 146 parts of adipic acid, 92 parts of glycerin, and 280 parts of soybean oil fatty acid were charged into a reactor, and the esterification reaction was carried out at 160 to 200°C to reach an acid value of 107 and a hydroxyl value of 5 or less. At that point, perform dehydration under reduced pressure, and after cooling, the temperature inside the flask is 120℃.
When reaching 0.14 parts of hydroquinone, tertiary amine
3.5 parts of glycidyl methacrylate was added thereto, and 142 parts of glycidyl methacrylate was gradually added dropwise to obtain a reaction product having a resin acid value of 7 at a reaction temperature of 100°C. This reactant contains itaconic acid dibutyl ester 77
100 parts of diallyl maleate to obtain a resin composition. Cobalt naphthenate 6 was added to 100 parts of this resin composition.
% solution 0.4 parts, methyl ethyl ketone peroxide
Add 1.0 part and mix, then add 250 parts of 200 mesh silica powder, stir well, and leave for 10 to 15 minutes.
Leave to stand for a minute to form a resin mixture. When this resin mixture was injected into a case containing an impedance element and heated at 80°C for 1 hour, the resin mixture hardened into a rubber-like state, making it possible to obtain a flexible impedance device. As described above, for the impedance devices manufactured in Examples 1 to 3, the coil temperature was tested with the device alone,
Finally, we installed it on a rapid start type ballast for two 110W fluorescent lamps and measured the humming noise. The comparative example is for an impedance device made with a conventional styrenic unsaturated polyester resin blend. The results are shown in Table 1.

[Table] As is clear from Table 1, the impedance device of the present invention has extremely low volatilization of the reactive diluent during curing, and therefore boasts low odor, as well as excellent heat dissipation and low humming noise. In terms of absorption properties, it is also superior to conventional products filled with styrenic unsaturated polyester resin mixtures. Furthermore, when a ballast incorporating the impedance device of the present invention was repeatedly used for a long period of time, the filling of the impedance device had extremely few cracks, and there were no failures such as coil breakage due to cracks.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of an impedance device of the present invention, and FIG. 2 is a longitudinal cross-sectional view taken along the line shown in FIG. 1. 1... Case, 2... Impedance element, 5
...Filled and hardened resin mixture.

Claims (1)

[Claims] 1 A dibasic acid, a polyhydric alcohol, and a vegetable oil fatty acid are reacted to form a polyester precondensate having an acid value of 40 or more and a hydroxyl value of 5 or less, and then the above precondensate is reacted with an unsaturated monomer having a glycidyl group to react. A curable resin mixture consisting of a resin composition and an inorganic filler with no or a small amount of a diluent added is filled into the gap between the case and the impedance element housed in the case and hardened. An impedance device.