JPS6144946A - Heat-resistant resin composition - Google Patents

Abstract

PURPOSE:A resin composition having excellent adhesiveness, suitable for use as a varnish for heat-resistant insulated wire, etc., containing a specified polyesterimide resin and melamine. CONSTITUTION:A polyesterimide resin (A) which has imide linkage in the molecular chain and is obtained by reacting an acid component (a) containing about 10-60 equivalent % imidic acid of the formula (where R is a divalent organic group) with an alcohol component (b) containing at least about 30 equivalent % tris-2-hydroxyethyl isocyanurate at about 120-240 deg.C in an excess of the alcohol component and melamine (B) in an amount of 0.03-5wt% of component A are dissolved in a phenolic solvent (C), preferably (A+B) being about 20-50wt% with C being about 80-50wt%, thus giving the titled resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention relates to a heat-resistant resin composition with improved adhesion and the like.

(Background of the Invention) Heat-resistant resin compositions, especially varnishes for heat-resistant enamelled wires, have conventionally been used as polyamide-imide varnishes, polyimide varnishes,
Polyester imide varnishes and polyamide imide ester varnishes are known.

Among these, varnishes using resins in which polyester is modified with imide bonds or amide-imide bonds, such as polyester imide varnish and polyamide imide ester varnish, are often used from the viewpoint of a balance between properties and price.

However, polyester imide varnish and polyamide imide ester varnish are manufactured using relatively inexpensive materials, so although they are superior in terms of economy (price),
It has the disadvantage of poor adhesion, which is particularly problematic when used as a thick film on heat-resistant enameled wire with a large wire diameter.

(Object of the invention) The object of the present invention is to eliminate the drawbacks of the prior art,
An object of the present invention is to provide a heat-resistant resin composition having excellent adhesion and the like.

(Summary of the Invention) In order to achieve this objective, the present inventors conducted various studies on improving the adhesion of polyester imide varnish, and as a result, discovered that the adhesion of polyester imide varnish to which melamine was added was excellent. We have arrived at the present invention.

The present invention provides a polyester resin having an imide bond in the molecular chain and at least a part of the alcohol component being tris-2-hydroxyethyl isocyanate, and a polyester resin containing 0.03 to 5% by weight of the polyester resin. melamine.

The polyester resin having an imide bond in the molecular chain used in the present invention (hereinafter referred to as polyester imide resin) is, for example, represented by the following general formula (1) (wherein R is a divalent organic group). It can be obtained using imidic acid. Imidic acid represented by the general formula (1) can be obtained, for example, by reacting 2 mol of trimellitic anhydride with 1 mol of diamine or diisocyanate (Japanese Patent Publication No. 51
(Refer to Publication No.-40113). Examples of diamines used in this case include aromatic diamines such as 4,41-diaminodiphenylmethane, p-phenylenediamine, and m-phenylenediamine, and aliphatic diamines such as hexamethylenediamine. Aromatic diamines are preferred. The diisocyanate is not particularly limited, and aromatic diisocyanates such as 4,4'-diphenylmethane diisocyanate and toluylene diisocyanate are preferred. There are no particular restrictions on the manufacturing method of immi and acid, but
For example, the reaction between a diamine and trimellitic anhydride is carried out at a temperature of 120 to 250°C in the presence of a polar solvent such as cresol, phenol, or N-methylpyrrolidone. Production of imide acid can be confirmed by distillation of water generated during production of imide acid.

The amount of imide acid used is determined from the viewpoint of heat resistance and economy (the effective resin content decreases when the resin composition is adjusted to an appropriate viscosity as an enameled wire varnish).
0% equivalent % is preferred.

As the acid component of the polyesterimide resin, in addition to the above-mentioned imide acid, terephthalic acid, isophthalic acid, or derivatives thereof such as dimethyl terephthalate and dimethyl isophthalate are used. In addition, tris-2-hydroxyethyl isocyanurate is used as at least a part of the alcohol component, and other alcohol components include dihydric or higher alcohols, such as ethylene glycol, neopentyl glycol, 1,4-butanediol, Dihydric alcohols such as 6-hexanediol and 1,6-cyclohexane dimetatool, and trihydric or higher alcohols such as glycerin, trimethylolpropane, and pentaerythritol are used.

From the viewpoint of heat resistance, it is preferable to use tris-2-hydroxyethyl isocyanurate in an amount of 30 equivalent % or more, particularly preferably 50 to 100 equivalent %, of the alcohol component.

When producing polyesterimide resin, the equivalent ratio of the acid component to the alcohol component is set at an alcohol excess of 1 to 80.
% alcohol excess is preferred.

When the acid component and the alcohol component are reacted by heating, there are no particular limitations as long as the conditions are such that the esterification reaction and the transesterification reaction occur substantially. For example, it is carried out at a temperature of 120 DEG to 240 DEG C. in the presence of a trace amount of an esterification catalyst such as a tetraalkylchichnate, lead acetate, or dibutyltin dilaurate. Furthermore, the synthesis may be carried out in the presence of a solvent such as cresol depending on the viscosity.

When producing polyesterimide resin, (1)
First, imide acid is synthesized, and then the remaining polyester components (acid component and alcohol component) are added and esterified. (2) All components are reacted at the same time to perform imidization and esterification at the same time. (3) Imid acid There are various synthesis methods, such as reacting polyester components other than the components in advance and then adding an imide acid component to perform imidization and esterification, but there are no particular limitations.

The amount of melamine used in the heat-resistant resin composition of the present invention is 0.01 to
The amount is 5% by weight, preferably 0.02 to 0.2% by weight. If the amount of melamine added is less than 0.03% by weight, the adhesion will not be sufficiently improved, and if it exceeds 5% by weight, the deterioration resistance will decrease.

The heat-resistant resin composition of the present invention is produced by dissolving a polyesterimide resin and melamine in a solvent and adjusting the viscosity to an appropriate value. The solvent used at this time is
There is no particular restriction on the solvent as long as it dissolves both the polyesterimide resin and melamine, but for example, phenolic solvents such as cresol, phenol, and xylenol are used.

Furthermore, as a co-solvent, for example xylene, Nl5SEKI
HISOL-100,150 (Japan Petrochemical Co., Ltd.)
(product name of aromatic hydrocarbon), methyl ethyl ketone,
Dimethyl succinate, methylcarpitol, etc. can also be used.

The heat-resistant resin composition of the present invention preferably contains a total of 20 to 50% by weight of polyesterimide resin and melamine, and 80 to 50% by weight of a solvent.

The heat-resistant resin composition of the present invention may optionally contain, for example, a titanium compound, a polyisocyanate generaque, an organic acid metal salt, a polyamide resin, a polyhydantoin resin, an alkoxy-modified amino resin, a polysulfone resin, a phenol resin, etc. as a resin component. It may be contained in a proportion of 0.1 to 25% by weight.

The resin composition of the present invention is made into an insulated wire by a conventional method by applying and baking it directly onto an electric conductor or together with another insulating film.

The heat-resistant resin composition of the present invention is widely used in heat-resistant insulated wires, heat-resistant paints, and the like.

(Effects of the Invention) The heat-resistant resin composition of the present invention has significantly superior adhesion and flexibility compared to conventional heat-resistant resin compositions by blending melamine with polyesterimide resin. It is a heat-resistant resin composition that does not show any deterioration in properties such as thermal shock resistance and softening resistance.

(Example of the invention) The present invention will be explained below with reference to Examples.

Production example (synthesis of polyesterimide resin) Diaminodiphenylmethane 108.8g (35 equivalents), trimellitic anhydride 211.0g (70 equivalents), dimethyl terephthalate 198.0g (65 equivalents), ethylene glycol
14.6 g (1'5 eq.), 368.8 g (135 eq.) tris-2-hydroxyethyl isocyanurate, 300.0 g cresol and 0.4 g tetrabutyl titanate in a fourth tube equipped with a thermometer and stirrer. The mixture was placed in a flask and reacted at 170° C. for 1 hour while refluxing toluene to remove azeotropic water. Next, while distilling toluene off, this liquid was heated to 210°C and heated to 250°C.
The temperature was maintained until the gelation time on a gel plate at 120 seconds reached 120 seconds. Next, 650g of cresol HISOL-1002
After adding 38 g and lowering the temperature to 100°C, 15.9 g of tetrabutyl titanate), 26.5 g of zinc naphthenate and VP'-51 (phenolic resin, manufactured by Hitachi Chemical Co., Ltd.) were added. 23.7g was added. The resulting resin composition had a nonvolatile content (heated at 200°C for 2 hours) of 41% by weight, and a viscosity (30°C) of 42 poise.

Example 1 0.4 g of melamine was added to 1,000 g of the resin composition produced in Production Example, and the mixture was stirred at 60°C for 1 hour to obtain a uniform solution.

Example 2 191.8 g (70 equivalents) of terephthalic acid, 30.7 g (30 equivalents) of ethylene glycol, 344.5 g (120 equivalents) of tris-2-hydroxyethyl isocyanurate, 300 g of cresol and 0.8 g of dibutyltin dilaurate. The mixture was placed in a fourth flask equipped with a thermometer and a stirrer, and the temperature was raised to 210'C, and the reaction was allowed to proceed until no unreacted terephthalic acid residue was visible in the contents.

The temperature was then lowered to 100°C and further 98.0 g (30 eq.) of diaminodiphenylmethane and 190.1 g (60 eq.) of trimellitic anhydride were added,
The temperature rose to 'C. Furthermore, 30 g of toluene was added, and the azeotropic water was removed while refluxing, and the mixture was kept at a temperature for 1 hour. Next, while toluene was distilled off, the temperature of this liquid was raised to 210°C, and the temperature was kept until gelation time on a gel plate at 250°C reached 90 seconds. Next, 700g of cresol HI
After adding 250 g of SOL-100 and lowering the temperature to 105°C, an additional 16.0 g of tetrabutyl titanate was added.
, zinc naphthenate 22.0 g and VP 51
(7s/-le resin, manufactured by Hitachi Chemical Co., Ltd.) 26.5
g, and further added 1.0 g of melamine. The resulting resin composition had a nonvolatile content (heated at 200°C for 2 hours) of 40% by weight and a viscosity (30°C) of 62 poise.

Example 3 123.6 g (40 equivalents) of diaminodiphenylmethane,
239.6 g (80 equivalents) of trimellitic anhydride, 181.6 g (60 equivalents) of dimethyl tereclate, Tris-
434.3g of 2-hydroxyethyl isocyanurate (
160 equivalents), 450 g of cresol, and 0.4 g of tetrabutyl titanate were placed in a four-bottle flask equipped with a thermometer and a stirrer, and the reaction was carried out at 170°C for 1 hour while refluxing toluene. Removed.

Next, while toluene was distilled off, the temperature of this liquid was raised to 205°C, and the temperature was kept until gelation time on a gel plate at 250°C reached 140 seconds. Next, 650 g of cresol and 288 g of HISOL-100 were added, and 16.2 g of tetraisopropyl titanate and 20 g of zinc naphthenate were added.
．． 0 g-VP 51 (7x/-le resin, manufactured by Hitachi Chemical Co., Ltd.) 23.7 g and melamine 0.6 g
was added. Non-volatile content of the obtained resin composition (200°C
-2 hours heating) was 38% by weight, and the viscosity (30°C) was 45 poise.

The resin compositions obtained in Production Examples and Examples 1 to 3 were baked on copper wires with a diameter of 1 crane under the following conditions with a type 0 finish to obtain insulated wires, and the properties of the wires were measured.

The results are shown in Table 1.

Table 1 (Note) Baking furnace: Hard furnace, furnace length 4m Baking temperature (℃): Inlet/Center/Exit = 260/360/400 The test was conducted according to JIS C3003.

As is clear from the results in Table 1, in the case of the examples of the present invention, the lifting of the film during sudden cutting, which is one of the evaluation methods for adhesion, was observed when melamine was not added (comparative example). No. 1
It is shown that the length is significantly improved from 2 mm to 2 to 3 m, and the twisting is also extremely improved, and the properties of flexibility, thermal shock resistance, and softening resistance are not deteriorated. .

Claims (1)

[Claims] 1. A polyester resin having an imide bond in the molecular chain and at least a part of the alcohol component being tris-2-hydroxyethyl isocyanurate, and 0.03 to 5% by weight of the polyester resin. A heat-resistant resin composition containing melamine.