JPS6144885B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an electrically insulating resin composition that has excellent curability, air-drying properties, and crack resistance and is used for impregnating and casting coils of electrical equipment. In electrical equipment, we fix the various coils, cores, etc. used in them to improve their mechanical strength, as well as to reduce noise, prevent moisture, prevent rust, improve thermal conductivity, and increase insulation. Treated with coil impregnation varnish or casting varnish. Unsaturated polyester resins, which are relatively well-balanced in terms of mechanical properties, electrical properties, workability, price, etc., are widely used as processing varnishes for such electrical equipment. Recently, there has been a demand for faster curing of unsaturated polyester resins in order to shorten the varnish processing time for electrical equipment, thereby saving energy and reducing costs.
There are problems such as a significant drop in workability due to the extremely short pot life. In addition, in order to obtain sufficient performance, ordinary unsaturated polyester resins have a high molecular weight, and crosslinking monomers such as styrene are mixed in to make the resin have a high viscosity and good workability. However, it has the disadvantage that the monomer evaporates during use, deteriorating the working environment, and also causes pollution problems such as bad odors and air pollution, so improvements are required.
Research is being conducted on reducing the amount of irritating monomers such as styrene by increasing the solidity of the resin, and using low-volatility monomers, but it has not been possible to sufficiently satisfy the characteristics for impregnating coils of electrical equipment or as casting resins. I haven't reached it yet. The present invention has been made to improve these problems. The present invention uses a maleic acid oil (a) obtained by adding 5 to 30 parts by weight of maleic anhydride to 100 parts by weight of dry or semi-dry animal or vegetable oil, and the formula (However, R ₁ is hydrogen or a methyl group, and R ₂ is hydrogen or an alkyl group.) The hydroxyalkyl acrylate or hydroxyalkyl methacrylate (b) represented by An epoxy compound () having at least one epoxy group in the addition reaction product () obtained by addition reaction of 0.5 mol or more of acrylate or hydroxyalkyl methacrylate
The present invention relates to an electrically insulating resin composition containing a resin obtained by reacting 1 carboxyl group of an addition reaction product (2) with 1 or less epoxy groups of an epoxy compound (2). The resin composition of the present invention has excellent curability and air-drying properties compared to conventional unsaturated polyester resins, and as a result, processing time can be reduced by 20 to 50% when electrical equipment is impregnated. . Further, since the resin of the present invention has a low viscosity, the amount of monomer used can be significantly reduced, and since it can be made to have a high solidity, a resin composition that is useful for environmental improvement and pollution prevention can be obtained. The maleic oxidized oil used in the present invention is, for example, 100 parts by weight of a dry or semi-dry animal or vegetable oil such as linseed oil, tung oil, soybean oil, rice bran oil, coconut oil, safflower oil, dehydrated castor oil, cottonseed oil, or fish oil. It is obtained by adding maleic anhydride in an amount of 5 to 30 parts by weight to 100% by a known method using a solvent such as toluene or xylene as necessary. When the addition reaction ratio of maleic anhydride to animal and vegetable oils is lower than the above-mentioned ratio, the amount of acid anhydride groups introduced into the animal and vegetable oils will be small, and the reaction with the above-mentioned hydroxyalkyl acrylate or hydroxyalkyl methacrylate will be reduced. As a result, the amount of vinyl groups introduced into the animal or vegetable oil also decreases, resulting in a decrease in the curability of the resulting resin composition. In addition, if the ratio of maleic anhydride to animal and vegetable oil is higher than the above-mentioned ratio, the viscosity will increase during the addition reaction between maleic anhydride and animal and vegetable oil, and during the addition reaction between maleic oxidized oil and hydroxyalkyl acrylate or hydroxyalkyl methacrylate. It becomes larger and the resin becomes more likely to become cloudy. Preferably, the addition reaction amount of maleic anhydride is 10 to 20 parts by weight per 100 parts by weight of dry or semi-dry animal or vegetable oil. Also, the expression

The hydroxyalkyl acrylate or hydroxyalkyl methacrylate represented by the formula (wherein R ₁ is hydrogen or a methyl group, and R ₂ is hydrogen or an alkyl group) include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl methacrylate, −
Examples include hydroxypropyl acrylate and 2-hydroxypropyl methacrylate, and these can be used alone or in combination of two or more. These hydroxyalkyl acrylates or hydroxyalkyl methacrylates are added to maleic oil at a ratio of 0.5 mol or more per 1 mol of acid anhydride groups in maleic oxidized oil to obtain an addition reaction product with an acid value of 40 or more. . If the amount of hydroxyalkyl acrylate or hydroxyalkyl methacrylate is less than 0.5 mol, the amount of vinyl groups introduced will be small, resulting in a marked decrease in curability. Epoxy compounds having at least one epoxy group include glycidyl ethers such as methylene glycol diglycidyl ether, phenyl glycidyl ether, bisphenol A diglycidyl ether, allyl glycidyl ether, acrylic acid glycidyl ester, methacrylic acid glycidyl ester, Versatelic acid glycidyl ester (e.g. Cardyura E from Shell Petrochemical)
glycidyl esters such as epoxidized polybutadiene (for example, LPE-1000-
Examples include α-olefin oxide such as 3.5), dicyclopentadiene oxide, and alicyclic epoxide such as 3,4 epoxycyclohexyl carboxylate, and these can be used alone or in combination of two or more types. The epoxy compound having at least one epoxy group is reacted in a ratio of 1 or less epoxy groups to 1 carboxyl group in the addition reaction product having an acid value of 40 or more obtained by the above addition reaction. , a resin with an acid value of 40 or less can be obtained. The reason why the ratio of epoxy groups is set to 1 or less is because it is necessary to lower the acid value. The higher the acid value, the more likely it is to have negative effects on compatibility with magnet wires and various component materials used in the structures of electrical equipment, rusting of metals, and stability of varnishes. It is desirable that the acid value be 30 or less. The resin obtained in this way has a low viscosity, so
It is possible to achieve high solidity, and the amount of crosslinking monomer used can be significantly reduced, making it possible to improve pollution problems such as bad odors and air pollution.
It also has excellent curability, air-drying properties, and clutch resistance, and can be used as a varnish for impregnating coils of electrical equipment or for casting. When using a crosslinkable monomer in the resin composition of the present invention, styrene, vinyltoluene, α-methylstyrene, paratertiary butylstyrene, chlorostyrene, divinylbenzene, diallylphthalate, methylacrylate or methylmethacrylate, ethyl acrylate or ethyl methacrylate, uralyl acrylate or lauryl methacrylate, 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate or 2
- Hydroxypropyl methacrylate, a monofunctional acrylic ester or methacrylic ester such as a reaction product of acrylic acid or methacrylic acid and Cardiula E (Ciel Petrochemical, trade name), ethylene glycol diacrylate or ethyl glycol dimethacrylate, 1.6 - Difunctional acrylic ester or methacrylic ester such as hexanediol diacrylate or 1,6-hexanediol dimethacrylate, trimethylolpropane acrylate or trimethylolpropane trimethacrylate, tris(2-hydroxyethyl)isocyanuric acid acrylate Alternatively, trifunctional acrylic esters or methacrylic esters such as tris(2-hydroxyethyl) isocyanuric acid methacrylate are used alone or in combination of two or more types. Further, the resin composition of the present invention may optionally include:
The above-mentioned crosslinkable monomers can be used in combination with other resins, or by adding organic peroxides, photosensitizers, curing accelerators, inorganic fillers, pigments, and the like. Examples of resins that can be used in combination with the resin composition of the present invention include oil-less, oil-modified, dicyclopentadiene-modified and other unsaturated polyester resins, polybutadiene resins, xylene formaldehyde resins, and the like. Furthermore, as a curing method for the resin composition of the present invention, a method of curing at room temperature or by heating by radical polymerization using an organic peroxide is applied. Peroxides, 1.1 ditertiary butyl peroxy 3.5.5 trimethylcyclohexane, 1.
1 Peroxyketals such as ditertiary butyl peroxycyclohexane, hydroperoxides such as kyumene hydroperoxide and tertiary butylhydroperoxide, diacyl peroxides such as benzoyl peroxide and acetyl peroxide, dicumyl These include dialkyl peroxides such as peroxide, and peroxy esters such as tert-butyl peroxybenzoate and tert-butyl peroxy acetate, which can be used alone or in combination.
Used in combination of more than one type. In addition, a photosensitizer can be added to make a photopolymerizable resin composition, but examples of photosensitizers include benzoin, benzoin ethers, benzointhioethers, benzophenone, acetophenone, 2-ethylanthraquinone furoin, and benzoin. Ether-Michler ketone, decyl chloride, etc. can be used. Metal salts of cobalt, manganese, lead, iron, etc. of organic acids such as naphthenic acid and octenoic acid as necessary;
Curing accelerators such as N.N'-dimethylaniline can also be used. Also, hydroquinone,
Commonly used polymerization inhibitors such as toluhydroquinone, tert-butylcatechol, parabenzoquinone, and pyrogallol can also be used. The resin composition of the present invention may contain inorganic fillers such as silica sand, alumina, silica, glass powder, calcium carbonate, barium sulfate, sand, mica powder, talc, pigments, dyes, etc., as needed. be able to. EXAMPLES Next, the present invention will be explained by examples, but the present invention is not limited to these examples. In the examples, % indicates weight %. Example 1 550 g of linseed oil and 100 g of maleic anhydride were placed in a 4-necked flask (No. 1), and nitrogen gas was blown into the flask.
After reacting at 220℃ for 3 hours, lower the temperature to 80℃,
Next, 120g of 2-hydroxyethyl acrylate,
Add 0.8g of hydroquinone and blow air into it.
The reaction was carried out at 120°C for 3 hours, and when the acid value reached 65, 150g of Cardiura E (manufactured by Ciel Petrochemicals, epoxy equivalent: 245-250) was added and the reaction was continued. Resin (A) was obtained. 300g of this resin (A), 200g of styrene, and hydroquinone
After adding 0.1 g and uniformly dissolving, 2.5 g of 8% manganese naphthenate was added and dissolved, and then 5 g of benzoyl peroxide was added to obtain varnish (a). Example 2 To 250 g of resin (A) obtained in Example 1, 125 g of diallyl phthalate and 2-hydroxyethyl methacrylate were added.
125g and 0.05g of hydroquinone were added and dissolved uniformly, then 2g of 8% manganese naphthenate was added and dissolved, and further 4g of benzoyl peroxide was added to obtain varnish (b). Example 3 Flaxseed oil 400g, soybean oil 400g, maleic anhydride
Pour 100g into the four-necked flask (1), react at 220℃ for 3 hours under nitrogen gas blowing, and then heat to 120℃.
Then add 70 g of 2-hydroxyethyl acrylate and 60 g of 2-hydroxypropyl methacrylate.
g, 1 g of hydroquinone was charged, the reaction was continued for 3 hours under air blowing, and when the acid value reached 60, 60 g of acrylic glycidyl ether was added and the reaction was continued to produce a resin (B) with an acid value of 25 and a viscosity of 45 poise (at 25°C). ) was obtained. 300 g of this resin (B), 100 g of xylene formaldehyde resin (trade name, Nicanol LL, manufactured by Mitsubishi Gas Chemical Co., Ltd.), 50 g of 2-hydroxyethyl methacrylate, 50 g of lauryl methacrylate, 0.1 g of hydroquinone, 5 g of 6% cobalt octenoate.
Add 5g of tert-butyl peroxybenzoate to make a varnish.
I got (c). Varnishes (a) to (c) obtained in Examples 1 to 3, commercially available styrenic unsaturated polyester varnish (d) as conventional typical unsaturated polyester varnish, low odor unsaturated polyester varnish (e), (f) and the properties of their cured products are shown in Table 1.

[Table] As shown in Table 1, the resin compositions (a), (b), and (c) of the present invention are different from conventional unsaturated polyester varnishes.
Compared to (d), (e), and (f), it is possible to create a high-solid varnish with a significantly reduced amount of monomer used, which can improve environmental pollution, as well as hardenability and air drying properties. It has excellent crack resistance and is suitable as a varnish for impregnating coils of electrical equipment or for casting.

Claims (1)

[Scope of Claims] 1 Maleic oxidized oil (a) obtained by addition-reacting 5 to 30 parts by weight of maleic anhydride to 100 parts by weight of dry or semi-dry animal or vegetable oil and the formula (However, R ₁ is hydrogen or a methyl group, and R ₂ is hydrogen or an alkyl group.) The hydroxyalkyl acrylate or hydroxyalkyl methacrylate (b) represented by An epoxy compound () having at least one epoxy group in the addition reaction product () obtained by addition reaction of 0.5 mol or more of acrylate or hydroxyalkyl methacrylate
An electrically insulating resin composition comprising a resin obtained by reacting 1 carboxyl group of an addition reaction product (2) with 1 or less epoxy groups of an epoxy compound (2).