JP2835847B2 - Resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a resin composition having excellent heat resistance and excellent flexibility in coating film.

(Prior Art) Unsaturated polyester resins are used in various fields because of their excellent mechanical, electrical and thermal properties and their relatively good balance of workability and price. Even for electrical insulation,
Particularly, because of its excellent workability, it is often used for coil impregnation and casting. The unsaturated polyester resin is
A curing catalyst and a crosslinking monomer are mixed with the unsaturated polyester, and a curing reaction is performed by heating or irradiating ultraviolet rays in the presence of a radical polymerization initiator. In the case of coil impregnation etc., unsaturated polyester resin with better heat resistance is required due to its small size and light weight, especially for transformers of microwave ovens.
Conventionally, the highest heat resistance of 0 ° C to 200 ° C or higher has been required.

However, a conventional unsaturated polyester resin generally uses phthalic anhydride, isophthalic acid or a derivative thereof as a saturated dicarboxylic acid of an unsaturated polyester, and ethylene glycol, propylene glycol or the like as a diol. Heat resistance over ℃ cannot be obtained.
Even if an attempt is made to obtain heat resistance of 80 ° C or higher, the material becomes brittle after curing, resulting in reduced crack resistance and reduced compatibility with heat-resistant wires, causing cracks on the coating surface and causing practical problems. Nothing was satisfactory enough.

(Problems to be Solved by the Present Invention) The present invention has been made in view of the above circumstances, and has excellent heat resistance, coating film flexibility, and coating surface drying property, becomes brittle after curing, and has crack resistance. An object of the present invention is to provide a resin composition which does not decrease, has good compatibility with heat-resistant electric wires, and is economical.

[Constitution of the Invention] (Means for Solving the Problems) The present inventors have diligently studied to achieve the above object, and can easily convert terephthalic acid using inexpensive polyethylene terephthalate as a saturated polybasic acid component. Introduce a trifunctional tris (2-hydroxyethyl) isocyanurate as a polyhydric alcohol component to improve heat resistance and flexibility, and introduce a hydroxyacrylic acid ester derivative to a part of the polymerizable monomer. By using in combination with a styrene monomer, it has been found that the solubility of the styrene monomer in polyester can be improved,
The present invention has been completed.

That is, the present invention provides (A) (a) a transesterification product of polyethylene terephthalate, and (b) tris (2-
(Hydroxyethyl) isocyanurate and (c) an unsaturated polyester obtained by reacting a vegetable oil fatty acid, and (B) a polymerizable monomer comprising a (d) hydroxyacrylate derivative and (e) a styrene monomer, In the above-mentioned reaction for obtaining an unsaturated polyester (A), the transesterification product of (a) polyethylene terephthalate is converted to a terephthalic acid component in an amount of 5 to 50% based on the total basic acid equivalent, and (b) tris (2-hydrogen). (Oxyethyl) isocyanurate is blended so as to be 5 to 30% based on the total polyhydric alcohol equivalent, and the above (B)
A resin composition comprising (d) a hydroxyacrylate derivative in an amount of 1 to 20% by weight based on a polymerizable monomer.

 Hereinafter, the present invention will be described in detail.

The unsaturated polyester (A) used in the present invention comprises (a)
Transesterification products of polyethylene terephthalate,
It is obtained by reacting (b) tris (2-hydroxyethyl) isocyanurate and (c) vegetable oil fatty acid. These components will be described below.

The polyethylene terephthalate (a) used in the present invention is obtained by a polycondensation reaction between terephthalic acid and ethylene glycol, and is a linear polyester having the following structural formula.

Polyethylene terephthalate is transesterified by a catalyst such as a metal oxide such as lead or zinc, or an alkyl titanium compound, and the terephthalic acid and ethylene glycol obtained thereby are used as a basic acid and a polyhydric alcohol component, respectively. The blending ratio of polyethylene terephthalate is such that the terephthalic acid is 5 to 50% of the total basic acid equivalent constituting the polyester including the (c) vegetable oil fatty acid described below.
It is blended so that it becomes. If the compounding ratio is less than 5%, heat resistance is inferior, and the amount of inexpensive polyethylene terephthalate used is small, which is not economical. If it exceeds 50%, the viscosity becomes high, and it is not preferable because it does not dissolve in the polymerizable monomer. A more preferable compounding ratio is 10 to 30%.

(B) Tris (2-hydroxyethyl) isocyanurate used in the present invention is a trifunctional alcohol having the following structural formula.

The mixing ratio of tris (2-hydroxyethyl) isocyanurate is preferably 5 to 30% of the total polyhydric alcohol equivalent constituting the polyester, including ethylene glycol obtained by transesterification of polyethylene terephthalate. . If the amount is less than 5%, the heat resistance is not sufficient, and if it exceeds 30%, the viscosity becomes high or the polymerizable monomer becomes insoluble, which is not preferable.

Examples of the (c) vegetable oil fatty acid used in the present invention include fatty acids such as soybean oil, linseed oil, coconut oil, and tall oil, and their transesterified products.
A mixture of more than one species can be used. The blending ratio of the vegetable oil fatty acid is desirably 3 to 30% of the total basic acid equivalent including terephthalic acid obtained by transesterification of polyethylene terephthalate. If the amount is less than 3%, the viscosity becomes high and the polymer becomes insoluble in the polymerizable monomer, and the cured product becomes brittle, which is not preferable. If it exceeds 30%, heat resistance is undesirably reduced.

The unsaturated polyester of the present invention can be obtained by reacting a transesterification product of polyethylene terephthalate, tris (2-hydroxyethyl) isocyanurate, and a vegetable oil fatty acid, and in addition to these components, an unsaturated polybasic acid, Saturated polybasic acids, polyhydric alcohols, modified resins and the like can be blended. Examples of unsaturated polybasic acids include fumaric acid, maleic acid, itaconic acid and the like. Examples of the saturated polybasic acid include phthalic acid, isophthalic acid, tetrahydrophthalic anhydride, adipic acid and the like. Polyhydric alcohols include ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, neopentyl glycol, glycerin, 1,3 butanediol, hydrogenated bisphenol A, bisphenol A
Alkylene oxide adduct, pentaerythritol and the like. Examples of the modified resin include an isocyanate compound, an epoxy compound, a cyclopentadiene oil, an epoxidized oil, a petroleum resin, and a thermoplastic resin.

The (B) polymerizable monomer used in the present invention contains (d) a hydroxyacrylate derivative and (e) a styrene monomer.

Examples of the (d) hydroxyacrylate derivative used in the present invention include 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate, and these are used in combination with a styrene monomer. The mixing ratio of the hydroxyacrylate derivative is desirably 1 to 20% by weight based on the polymerizable monomer. If the compounding amount is less than 1% by weight, the solubility in the unsaturated polyester decreases and the solution becomes cloudy,
Separation into phases is undesirable. On the other hand, if it exceeds 20% by weight, the cured coating film becomes thin and is not economical.

The resin composition of the present invention contains (A) an unsaturated polyester and (B) a polymerizable monomer as essential components, but other components such as a smoothing agent, as long as the object of the present invention is not adversely affected.
Rust inhibitors, flame retardants, fillers, pigments and the like can be added and blended. Further, the resin composition contains a polymerization inhibitor, a peroxide,
Redox curing, UV curing,
It can be cured by far infrared curing or the like. Well-known quinones, phenol derivatives and the like can be used as the polymerization inhibitor to be blended here. Examples of the peroxide include benzoyl peroxide, ditertiary butyl peroxide, tertiary butyl perbenzoate, lauroyl peroxide, cumene hydroperoxide and the like. Examples of the curing accelerator include metal salts such as cobalt, manganese, zirconium, lead, and zinc, and tertiary amines.

The resin composition of the present invention is subjected to transesterification by adding litharge in the presence of polyethylene terephthalate, tris (2-hydroxyethyl) isocyanurate, and a polyhydric alcohol. Then, an unsaturated polyester was obtained by adding a vegetable oil fatty acid, a basic acid, and a polyhydric alcohol. Thereafter, a hydroxyacrylic acid ester derivative, a styrene monomer, a polymerization inhibitor, and a curing accelerator are added to produce a resin composition. The resin composition thus obtained can be widely used for coil impregnation, casting, and the like. This resin composition can be cured by adding a peroxide.

(Action) The resin composition of the present invention has heat resistance by introducing terephthalic acid by transesterification of polyethylene terephthalate and trifunctional tris (2-hydroxyethyl) isocyanurate as a polyhydric alcohol component into the resin main skeleton. Improve. And the vegetable oil fatty acid is used to impart flexibility to the coating film and improve compatibility with heat-resistant electric wires. Further, the solubility of the styrene monomer in the polyester is improved by introducing and using a hydroxyacrylate derivative as a part of the polymerizable monomer.

(Example) Next, the present invention will be described with reference to examples, but the present invention is not limited to the following examples. In the following Examples and Comparative Examples, “parts” means “parts by weight”.

Example 1 120 parts of polyethylene terephthalate, 56 parts of tris (2-hydroxyethyl) isocyanurate, 60 parts of propylene glycol, and 0.1 part of litharge (PbO) were subjected to a transesterification reaction at 240 ° C. and cooled. Next, 40 parts of linseed oil fatty acid, 148 parts of maleic anhydride and 65.6 parts of ethylene glycol were added and reacted at 190 ° C. to obtain an unsaturated polyester. 0.25 parts of hydroquinone and 2-hydroxyethyl methacrylate 32 were added to the unsaturated polyester.
And 288 parts of a styrene monomer were mixed and diluted, and 0.6 part of a 6% cobalt naphthenate solution was further added to produce a resin composition.

Example 2 147.6 parts of polyethylene terephthalate, tris (2-
(Hydroxyethyl) isocyanurate 90.2 parts, propylene glycol 77.0 parts, and tetrabutyl titanate 0.
Twelve parts were transesterified at 240 ° C. and cooled. Next, 57.5 parts of soybean oil fatty acid, 123.0 parts of maleic anhydride, and 34.0 parts of propylene glycol were added and reacted at 190 ° C. to obtain an unsaturated polyester. 0.25 parts of hydroquinone, 33.0 parts of 2-hydroxyethyl methacrylate and 326 parts of styrene monomer were mixed and diluted with the unsaturated polyester, and further diluted with 0.6% manganese naphthenate solution 0.6.
Parts were added to produce a resin composition.

Example 3 111.3 parts of polyethylene terephthalate, tris (2-
(Hydroxyethyl) isocyanurate 73.8 parts, propylene glycol 58.2 parts, and tetrabutyl titanate 0.
08 parts were reacted at 240 ° C. to perform transesterification and cooled. Then, 53.3 parts of soybean oil fatty acid, maleic anhydride 14
Add 4.3 parts and 78.0 parts of propylene glycol to 190 ℃
To give an unsaturated polyester. 0.25 parts of hydroquinone, 33.0 parts of 2-hydroxyethyl methacrylate, and styrene monomer
333.0 parts were mixed and diluted, and 0.66 parts of a 6% manganese naphthenate solution was further added to produce a resin composition.

Example 4 116.2 parts of polyethylene terephthalate, tris (2-
83.0 parts of (hydroxyethyl) isocyanurate, 58.1 parts of propylene glycol, and 0.1 part of litharge (PbO) were added, and the mixture was transesterified at 240 ° C. and cooled. Next, 83.0 parts of tall oil fatty acid, 93.8 parts of maleic anhydride, 29.0 parts of tetrahydrophthalic anhydride, and 42.0 parts of ethylene glycol were added and reacted at 190 ° C. to obtain an unsaturated polyester. To this unsaturated polyester was added hydroquinone 0.25 part, 2-hydroxypropyl acrylate 33.3
And 310 parts of a styrene monomer were mixed and diluted, and 0.6 part of a 6% manganese octenoate solution was further added to produce a resin composition.

Comparative Example 166 parts of isophthalic acid, 98 parts of maleic anhydride and 197 parts of propylene glycol were blended and reacted at 160 ° C. for 1 hour and then at 195 ° C. to obtain an unsaturated polyester. To this unsaturated polyester, 0.24 part of hydroquinone and 350 parts of styrene monomer were mixed and diluted, and 2.4 parts of a 6% cobalt naphthenate solution was added to prepare a resin composition.

The resin compositions prepared in Examples 1 to 4 and Comparative Example
1-Di-t-butylperoxy-3,3,5-trimethylcyclohexane was added. Using this resin composition, the coating film surface drying property, coating film flexibility, and heat resistance index by the twisted pair method were tested, and the results are shown in Table 1. The resin composition of the present invention was excellent in all properties, and the remarkable effect of the present invention was recognized.

[Effects of the Invention] As is clear from the above description and Table 1, the resin composition of the present invention is excellent in heat resistance, coating film flexibility, coating film surface drying property, becomes brittle after curing, and has crack resistance. And the compatibility with the heat-resistant wire is not reduced, so that the surface of the coating film is not cracked. Therefore, it is suitable as a resin composition for coil impregnation and casting.

Continuation of the front page (56) References JP-A-64-16819 (JP, A) JP-A-60-4564 (JP, A) JP-A-59-91113 (JP, A) (58) Fields investigated (Int) .Cl. ⁶ , DB name) C08L 67/06 C08F 283/01

Claims (1)

(57) [Claims] 1. An unsaturated polyester obtained by reacting (A) (a) a transesterification product of polyethylene terephthalate, (b) tris (2-hydroxyethyl) isocyanurate, and (c) a vegetable oil fatty acid; (B) The (d) hydroxyacrylate derivative and (e) a polymerizable monomer comprising a styrene monomer are essential components, and in the above-mentioned reaction (A) for obtaining an unsaturated polyester, (a) transesterification of polyethylene terephthalate The terephthalic acid component is blended in an amount of 5 to 50% based on the total basic acid equivalent, and (b) tris (2-hydroxyethyl) isocyanurate is blended in an amount of 5 to 30% based on the total polyhydric alcohol equivalent. And the above (B)
A resin composition comprising (d) a hydroxyacrylate derivative in an amount of 1 to 20% by weight based on the polymerizable monomer.