JPH0482008B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to an epoxy resin composition. More specifically, the present invention relates to a filler composition for electrical insulation, and particularly to an epoxy resin composition suitable as a filler for use in so-called semi-dry capacitors. (Prior art and its problems) Epoxy resins have been widely used for electrical insulation. However, since epoxy resins are expensive, attempts are made to reduce the price by adding inexpensive additives. For example, JP-A-53-125461 proposes an epoxy resin composition in which a petroleum resin according to a specific manufacturing method is added. However, the epoxy resin composition proposed in the above publication is not necessarily satisfactory as a filler for electrical insulation. In particular, there are points that need to be improved as filling compositions for metallized plastic film capacitors. (Means for Solving the Problems) The present invention further adds an aromatic hydrocarbon having three condensed or non-condensed aromatic rings to an epoxy resin and a petroleum resin produced by the specific production method described in the above-mentioned publication. This improves the performance of the composition as an electrically insulating filler. That is, the present invention comprises: (a) 100 parts by weight of an epoxy resin; (b) 100 parts by weight of a hydrocarbon fraction containing as a main component unsaturated hydrocarbons having a boiling point range of 80 to 280°C and produced as a by-product from thermal decomposition of petroleum. Phenols in part 7
5 to 900 parts by weight of a resin obtained by polymerizing with a Friedel-Crafts catalyst with the addition of 45 parts by weight, and (c) a carbonized aromatic compound having an average molecular weight of 230 to 350 and having three fused or non-fused aromatic rings. Hydrogen 4~
An epoxy resin composition comprising 200 parts by weight. The present invention will be further explained below. The main raw material of the resin used in the composition of the present invention is petroleum such as naphtha, kerosene fraction, or butane.
A cracked oil fraction with a boiling point range of 80 to 280°C, which is a by-product when producing olefins such as ethylene and propylene through thermal decomposition such as steam cracking,
Each distillate fraction is distilled within the boiling point range, or a mixture of these distillate fractions is appropriately prepared.
In such a fraction having a boiling point of 80 DEG to 280 DEG C., aromatic olefins having 8 to 10 carbon atoms such as styrene and alkylstyrenes, indenes and alkylindenes are present in large amounts, for example, 35 to 65% by weight. A cracked oil fraction with a boiling point of less than 80° C. is not preferred because the resin obtained therefrom has poor compatibility with epoxy resins. However, within the range in which the effects of the present invention are achieved, a small amount, such as 20% by weight or less, of a cracked oil fraction with a boiling point of less than 80 °C, for example, a boiling point range of 20 to 80 °C, is used, and the carbonization used in the present invention is used. It can also be used as a hydrogen fraction and polymerized. Next, the phenols to be added to the hydrocarbon fraction are phenols and alkyl-substituted phenols such as cresol, xylenol, tert-butylphenol, and nonylphenol, either alone or in a mixture of two or more. 7 to 45 parts by weight of phenols are mixed with 100 parts by weight of the above hydrocarbon fraction and polymerized using a Friedel-Crafts type catalyst. If the amount of phenols is less than 7 parts by weight, the resulting resin will have poor compatibility with the epoxy resin, and as a result, the performance of the capacitor will deteriorate. Moreover, if the amount exceeds 45 parts by weight, it is not preferable because not only will a resin with an extremely poor hue be obtained, but it will also be uneconomical. Polymerization involves boron trifluoride, aluminum chloride,
Adding 0.05 to 5% by weight of a Friedel-Crafts catalyst such as a boron trifluoride phenol complex or a boron trifluoride dialkyl ether complex to the raw material,
Perform for 10 minutes to 15 hours at a temperature range of -10 to +80°C. After polymerization, the catalyst is decomposed and removed with an alkali such as caustic soda or soda carbonate, washed with water if necessary, and unreacted oil and low-molecular polymers are separated by evaporation or distillation to obtain a pale yellow to yellow resin. . The resulting resin has a softening point (JIS K
2531-60) and a number average molecular weight of 500 to 1500. According to the IR spectrum, the resin used in the present invention obtained as described above is found to contain a large amount of phenolic hydroxyl groups, and is clearly different from conventional petroleum resins. The epoxy resin referred to in the present invention is not particularly limited, and is a conventionally known epoxy resin with a molecular weight of 300 to 300.
3000, and those having an epoxy equivalent weight of 150 to 3500 are usefully used. A typical example of this epoxy resin is one obtained as a reaction product of a compound having active hydrogen and epichlorohydrin. Compounds having active hydrogen include compounds having two or more phenolic OH groups in the molecule, such as bisphenol A, novolac resins, and derivatives thereof, and compounds having carboxyl groups, amino groups, etc. Good too. In particular, in the present invention, an epoxy resin obtained by the reaction of bisphenol A and epichlorohydrin can be advantageously used. In the present invention, the mixing ratio of the resin and the epoxy resin is 5 to 900 parts by weight of the resin per 100 parts by weight of the epoxy resin. If the amount of the resin exceeds 900 parts by weight, the epoxy resin will not be sufficiently cured and the original properties of the epoxy resin will be lost, which is undesirable, and if it is less than 5 parts by weight, the effect of adding the resin will not be produced. Further, the aromatic hydrocarbon which is the component (c) of the epoxy resin composition of the present invention is compatible with the epoxy resin having an average molecular weight of 230 to 350. Preferably, it is liquid or viscous semi-solid at room temperature,
It may be solid at room temperature as long as it is compatible with the epoxy resin. For example, representative aromatic hydrocarbons are aromatic hydrocarbons such as triarylalkane, dialkyl aromatic hydrocarbon, triaryl, aralkyldiaryl, arylnaphthalene, aralkylnaphthalene, and the like. These can be used alone or as a mixture of two or more. The average molecular weight is
If it exceeds 350, the compatibility with the epoxy resin decreases, so it is not preferable. Here, the dialkyl aromatic hydrocarbon, triaryl, aralkyl diaryl, etc. are more specifically represented by the following general formula (). Here, R ₁ and R ₂ are divalent hydrocarbon groups derived from aliphatic hydrocarbons having 1 to 4 carbon atoms such as methane, ethane, propane, butane, and j and k are 0 or 1. . Further, R ₃ to R ₅ are alkyl groups having 1 to 4 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, and l,
m and n are integers from 0 to 3. Specific compounds of formula () include, as examples of dialkyl aromatic hydrocarbons, dibenzyltoluene, dibenzylxylene, dibenzyl-ethylbenzene, dibenzylcumene, benzyl-methylbenzylbenzene, benzyl-ethylbenzylbenzene, benzyl- Dimethylbenzylbenzene, benzyl-propylbenzylbenzene, 1-tolyl-1-benzylphenyl-ethane, 1-xylyl-1-benzylphenyl-ethane, 1-ethylphenyl-1-benzylphenyl-
Ethane, 1-cumenyl-1-benzylphenyl-ethane, 1-phenyl-1-methylbenzylphenyl-
Ethane, 1-phenyl-1-dimethylbenzylphenyl-ethane, 1-phenyl-1-ethylbenzylphenyl-
Ethane, 1-phenyl-1-propylbenzylphenyl-ethane, 1-phenyl-1-benzyltolyl-ethane, 1-phenyl-1-benzylxylyl-ethane, 1-phenyl-1-benzylethylphenyl-
Ethane, 1-phenyl-1-benzylcumenyl-ethane, etc. Furthermore, di(α-methylbenzyl)benzene, α-methylbenzyl-(methyl-α-methylbenzyl)benzene, α-methylbenzyl-(dimethyl-α-methylbenzyl)benzene, α-methylbenzyl-(ethyl-α -methylbenzyl)benzene, α-methylbenzyl-(propyl-α-methylbenzyl)benzene, di(α-methylbenzyl)toluene, di(α-methylbenzyl)xylene, di(α-methylbenzyl)-ethylbenzene, di (α-methylbenzyl)-cumene, etc. Examples of triaryl and aralkyldiaryl include 4-isopropyl-m-terphenyl, 3
-butyl-m-terphenyl, 2-phenylethyl-biphenyl, and the like. Arylnaphthalenes and aralkylnaphthalenes include those represented by the following formula (). Here, R ₁ is a divalent group derived from an aliphatic hydrocarbon having 1 to 4 carbon atoms such as methane, ethane, propane, butane, and l is 0 or 1. In addition, R ₂ and R ₃ have 1 to 4 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl.
is an alkyl or cycloalkyl group, and m or n is an integer of 0 to 3. Specifically, the compounds include: 1-(ethylphenyl)-naphthalene, 1-benzyl-2-methyl-naphthalene, 1-benzyl-4-methyl-naphthalene, 1-methyl-3-(o-tolyl)-naphthalene, 1 -Methyl-3-(p-tolyl)-naphthalene, 1-methyl-4-(phenylethyl)-naphthalene, 2,7-dimethyl-(p-tolyl)-naphthalene, 2-(1-(o-tolyl)- ethyl)-naphthalene, etc. Three-ring aromatic hydrocarbons other than these formulas () or () include styrene, vinyltoluene,
Examples include triarylalkane made of a trimeric hydrogenated product of styrenes such as α-methylstyrene. The above aromatic hydrocarbon is added in an amount of 4 to 200 parts by weight per 100 parts by weight of the epoxy resin. If the amount is less than 4 parts by weight, the effects of the present invention cannot be achieved, and if the amount exceeds 200 parts by weight, the curing of the epoxy resin will be insufficient, so both are not preferred. Furthermore, the epoxy resin composition of the present invention contains 5 to 100 parts by weight, preferably 30 parts by weight, of a known curing agent for curing epoxy resins per 100 parts by weight of epoxy resin.
~50 parts by weight are mixed. Known hardeners include
Aliphatic amines such as diethylenetriamine, triethylenetetramine, adducts of epoxy resins and aliphatic amines, aromatic amines such as metaphenylenediamine, diaminodiphenylmethane, diaminophenyl sulfone, methylnadic anhydride, hexahydroic anhydride In addition to acid anhydrides such as urea resins, melamine resins, phenolic resins, polyisocyanates, etc. Further, in order to improve the thixotropic properties of the epoxy resin composition, inorganic fillers such as mica, silica, calcium carbonate, and talc can be mixed in any proportion. Other known flame retardants for epoxy resins, such as tetrabromobisphenol A, decabrom diphenyl ether, halogenated flame retardants such as chlorinated paraffin, ammonium phosphate, tricresyl phosphate, triethyl phosphate, Phosphorous flame retardants such as tris(β-chloroethyl) phosphate, acidic phosphate esters, nitrogen-containing phosphorus compounds, red phosphorus, tin oxide, ammonium trioxide, zirconium hydroxide, barium metaborate, aluminum hydroxide, magnesium hydroxide, etc. Inorganic flame retardants can also be used. In addition, reactive diluents such as monoepoxides such as styrene oxide and olefin oxide, polyepoxides such as divinylbenzene oxide, and non-reactive diluents such as dioctyl phthalate can also reduce the viscosity of the epoxy resin composition and improve workability. It is used for other reasons. Although the epoxy resin composition of the present invention can be used for paints and other purposes, it is preferably useful as a filler for electrical insulation. Here, a preferred form of use as an electrically insulating filler will be described below, in which the periphery of a capacitor element, at least a part of which is made of a metallized plastic film, is filled with an epoxy resin composition as a filler, It is a hardened metallized film (MF) capacitor. In other words, a metallized film capacitor is obtained by filling the above-mentioned epoxy resin composition into a case housing a capacitor element and heating and curing the composition. The case may be an exterior case for a capacitor, or a case may be a mold or a container. Here, the capacitor element is aluminum,
It is an element made by winding a plastic film metallized on one or both sides with metal such as zinc. As the plastic film, a polyolefin such as polypropylene or a polyester film such as polyethylene terephthalate is used. When winding, insulating paper or plastic film can be layered together with the metallized film. The element formed by winding is usually
Metallicon treatment is applied to the end face, and lead wires are attached. The case for housing the capacitor element as an exterior and the case as a container or mold may have any shape, and the material thereof is not particularly limited. A capacitor element is housed in a case, filled with an epoxy resin composition, and then heated to harden the epoxy resin. When the case is used as a container or mold,
After curing, the case is removed. Heating is carried out so as not to adversely affect the plastic film in the element, but usually a heating temperature of 70 to 100 DEG C. and a heating time of 1 to 5 hours are sufficient. (Effects of the Invention) By mixing a 3-ring aromatic hydrocarbon, an epoxy resin with excellent electrical properties can be obtained. The compositions of this invention are particularly useful as fillers for electrical insulation, especially metallized plastic film capacitors. (Filler) The present invention will be specifically described below based on the resin preparation, Examples, and Comparative Examples. Note that all formulation values in Tables 1 and 2 are parts by weight. Resin Preparation Example 1 Among cracked oil fractions obtained from naphtha steam cracking, unsaturated components with a boiling point range of 140 to 210℃
To 100 parts by weight of a hydrocarbon fraction containing 57% by weight, 18 parts by weight of phenol and 0.7 parts by weight of boron trifluoride ethyl ether complex were added and polymerized at 60°C for 3 hours. After polymerization, the catalyst was decomposed with an aqueous solution of caustic soda, washed with water, and unreacted oil was removed by vacuum distillation to obtain a resin () with a softening point of 95°C. Resin yield is
It was 58% by weight. Resin Preparation Example 2 Polymerization was carried out in the same manner as in Resin Preparation Example 1, except that 25 parts by weight of phenol was added to 100 parts by weight of the hydrocarbon fraction used in Resin Preparation Example 1, and the softening point was 83.
Resin () was obtained at °C. The resin yield was 62% by weight. Resin Preparation Example 3 The hydrocarbon fraction used in Resin Preparation Example 1 was fractionated by precision distillation into a fraction having a boiling point of 176 to 190°C. The unsaturated component in this fraction was 58% by weight, and the indene content was 37% by weight. To 100 parts by weight of this fraction, 25 parts by weight of nonylphenol was added, and 0.7% by weight of boron trifluoride phenol complex compound catalyst was added.
After polymerizing at 40°C for 3 hours, the same treatment as in Resin Preparation Example 1 was carried out to obtain a resin (). The resin yield was 58% by weight and the softening point was 97°C. Examples 1 and 2 and Comparative Examples 1 and 2 Aluminum was vapor-deposited on one side of a biaxially stretched polypropylene film having a thickness of 15 μm according to a conventional method to obtain a metallized plastic film having a width of 40 mm with a margin of 3 mm. A capacitor element made by winding this was housed in a case to create a model capacitor. Next, the epoxy resin having the composition shown in Table 1, the resin obtained in Resin Preparation Example 1 ()
and 3-ring aromatic hydrocarbon-containing epoxy resin compositions (Examples 1 and 2) were respectively filled to obtain capacitors with a capacity of about 5 μF. Subsequently, the epoxy resin was cured by heating at 90°C for 3 hours. After curing, the performance of the capacitor was investigated by applying a constant voltage to the capacitor and measuring the change in capacitance over time. The results are shown in Figure 1. For comparison, MF capacitors were filled with epoxy resin only (Comparative Example 1), and MF capacitors were filled with an epoxy resin composition containing an epoxy resin and the resin () obtained in Resin Preparation Example 1 (Comparative Example 2).
The MF capacitor was also tested for capacitor performance.

[Table] From the results shown in Figure 1, the MF capacitors filled with the epoxy resin compositions of Examples 1 and 2 are the same as those of Comparative Example 1.
Compared to the MF capacitor filled with the epoxy resin or epoxy resin composition of 2 to 2, it can be seen that this is an excellent capacitor with less change in capacitance over time. Examples 3 to 8 Epoxy resin compositions each containing an epoxy resin, the resins (), (), () obtained in Resin Preparation Examples 1 to 3, and a 3-ring aromatic hydrocarbon, each having the composition shown in Table 2. After filling a model capacitor with the sample and curing it in the same manner as in Example 1, the rate of change in capacity over time was determined. As a result, all the capacitors were almost the same as the capacitor of Example 1, and the performance was satisfactory.

【table】 [Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between capacitance changes and time of the capacitors of Examples 1 and 2 and Comparative Examples 1 and 2.

Claims (1)

[Scope of Claims] 1 (a) 100 parts by weight of an epoxy resin; (b) a hydrocarbon fraction containing as a main component unsaturated hydrocarbons with a boiling point range of 80 to 280°C that are by-produced by thermal decomposition of petroleum. 7 parts of phenols per 100 parts by weight
5 to 900 parts by weight of a resin obtained by polymerizing with a Friedel-Crafts catalyst with the addition of 45 parts by weight, and (c) a carbonized aromatic compound having an average molecular weight of 230 to 350 and having three fused or non-fused aromatic rings. Hydrogen 4~
An epoxy resin composition consisting of 200 parts by weight. 2. The epoxy resin composition according to claim 1, wherein the epoxy resin composition further contains 5 to 100 parts by weight of a curing agent per 100 parts by weight of epoxy resin.