JPS5940855B2 - Method for producing heat-resistant solvent-free varnish - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a solvent-free varnish that has a long pot life, is odorless, and has a cured product with excellent heat resistance.

The characteristics of the present invention are that it has an imide group with extremely good thermal stability in its molecule, and that it is a heat-resistant, solvent-free varnish that has an allyl group introduced as a polymerized cross-linking group, and can be used particularly as a varnish for electrical insulation treatment. The purpose is to provide a manufacturing method.
2. Description of the Related Art In recent years, there has been an extremely strong demand for resource and energy conservation, and efforts are being made to make various electrical devices smaller and lighter, as well as to exhibit higher performance.

In this case, the insulation treatment varnish must not only have high electrical properties, mechanical properties, water resistance, and chemical resistance, but also be particularly heat resistant.
Furthermore, it is important that the pot life is sufficiently long for processing operations such as varnish impregnation and casting. The inventors of the present invention are strongly aware of this background, and the pot life of varnish is sufficiently long, and the complexity of viscosity control such as replenishment of new varnish and partial varnish disposal resulting from increased viscosity of varnish, and material The present invention was completed as a result of extensive research into the development and manufacturing method of a new varnish material that eliminates loss and whose cured product has an insulating structure with extremely high heat resistance. The gist of the present invention is to react 1 mole of an oligoesterimide compound with a hydroxyl group at the end of the molecule with about 2 to 10 moles of a diallyl ester compound (B) to form a compound of the general formula (wherein R1 is the residue of a dibasic acid). The present invention provides a solvent-free varnish composition containing as a main ingredient an unsaturated esterimide compound represented by (X is a residue of a stenoleimide compound having a hydroxyl group at the end of the molecule).

According to the present invention, the reaction formula for the following explanation is octatermolecular terminal hydroxyl group oligoesterimide compound (4) unsaturated esterimide compound (1) and/or unsaturated esterimide compound (1) and 7 (CH2= CH-CH2-0-C-+! Mixture with R1 0 (wherein R2 is a glycol residue, R is a dibasic acid residue, R3 is a tricarboxylic acid residue, R
4 is a diamine residue, n is an integer from O to 5), first, an oligoester imide compound (A
) and 2 to 10 moles of diallyl ester compound (B) are subjected to alcoholinth reaction to introduce an allyl ester group into the hydroxyl group of the oligoesterimide compound (5).

This reaction is carried out by adding 0.1 to 1% by weight of a polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether, quinhydrone, sulfur chloride, etc. and using a conventional esterification reaction catalyst such as paratoluene as an alcoholic reaction catalyst. One type or a mixture of several types of sulfonic acid, paraxylene sulfonic acid, lead acetate, cadmium acetate, tetrapropyl titanate, etc. from 0.05 to
Add 1% by weight, 140-230℃, preferably 140-230℃
The reaction is completed by maintaining the temperature at 210° C. and distilling off 2 moles of allyl alcohol from the system. In the production method of the present invention, the proportion of diallyl ester compound 8 is as follows:
It is preferable to select from the range of 2 to 10 moles and carry out the above-mentioned alcoholinescence reaction.

In this case, the excess diallyl compound 03) is present in the varnish system based on the unsaturated esterimide compound (1),
It exerts the effect of a reactive diluent and also acts as a varnish constituent. Molecule terminal hydroxyl group oligoesterimide compound (4) used in the present invention
As shown in the above explanatory example, the molecular terminal functional imide compound (A) 5, the glycol (g) represented by the general formula HO-R2-0H, and the general formula HOOC-R1-C
It is obtained from a dibasic acid (h) represented by OOH. The molecular terminal functional imide compound (A)/
means that the molecular ends are -COOH and/or 0, respectively.
The imide compounds include the following. The imide compounds of formulas (1) to (9) are tricarboxylic acid anhydrides (a) represented by the general formula HOOC-Ra(CO, l'0), general formula /0C, ,C00ku0c':
Tetracarboxylic dianhydride (b) represented by , Re
Monoaminomonoalcohol represented by N-Rc-0H (
d) can be obtained by reacting diamine (e) represented by the general formula H2N-Rd-NH2.

In addition, in the imide compounds of formulas (3), (7), (8) and (9), the general formula 0C is used instead of the diamine (e).
Diisocyanate (f) represented by N-Rd-NCO can be used. Each of the above-mentioned components will now be explained.

Component (a) is trimellitic anhydride, 3,4,4'
-diphenyltricarboxylic anhydride, 3,4,4/-diphenyl ethertricarboxylic anhydride, ethylenetricarboxylic anhydride, 2,3,6'-naphthalenetricarboxylic anhydride, and the like. Component (b) includes pyromellitic dianhydride, 3,3/,4,4'-diphenyltetracarboxylic dianhydride, 2,2',3,3'-diphenyltetracarboxylic dianhydride, 2,3,6,7 naphthalenetetracarboxylic dianhydride, 2,2'-bis(
3,4-dicarboxyphenyl) propane dianhydride, butadiene tetracarboxylic dianhydride, and the like are used.
Component (c) includes γ-aminobutyric acid, anthralic acid,
Examples include p-aminobenzoic acid, m-aminobenzoic acid, and β-aminopropionic acid. Component (d) includes 2-amino-1-butanol, 2-amino-2-methyl-1-propanol, 2-aminoethanol, 3-amino-1-
Examples include propanol. Component (e) includes metaphenylenediamine, orthophenylenediamine, paraphenylenediamine, 2,4-toluenediamine, 2,6
-Toluenediamine, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 4
, 4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl, 4,4'-diaminobenzophenone, hexamethylenediamine, ethylenediamine, diaminopropane, 2,2-dimethylpropylenediamine and the like. The diisocyanates (f) that can be used in place of the component (e) include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-
Diphenylmethane diisocyanate, metaxylene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, etc. can be used. Each of the above-mentioned components (c), (d), (e), or (f) may be used alone, or a number of them may be mixed as appropriate. The imide compounds of formulas (1) to (9) are prepared by selecting the above-mentioned components and formulations from the formula and using a usual solvent such as m-cresol, dimethylformamide, dimethylacetamide, or a mixture of the above solvents with xylene, toluene, anisole, etc. It can be obtained by carrying out a condensation reaction in a solvent, or it can also be obtained by a reaction system containing a large excess of glycol instead of these solvents, and this selection can be made depending on the reaction conditions and described below. It should be decided based on the balance of the composition. ~ The imide compounds of formulas (1) to (9) thus obtained have molecular ends of −
It is COOH or -COOH and -0H.

To obtain the oligoester imide compound (4) with a hydroxyl group at the molecular terminal, an imide compound of the above formulas (1) to (9) and a glycol (g) such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, trimethylene glycol, or tetramethylene are used. One or more mixtures of glycol, neopentyl glycol, hydrogenated bisphenol A, etc. and dibasic acid or lower alkyl ester or anhydride (b) of said acid, such as phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid. and their anhydrides, such as isophthalic acid, terephthalic acid and their methyl and ethyl esters, succinic acid, maleic acid and their anhydrides, adipic acid, fumaric acid, etc., and conventional esterification with one type or a mixture of several types thereof. It is done by carrying out a reaction.

At this time, the functional group (-
By adjusting the composition of component (g) and/or component (h) based on the correspondence between the type and number of COOH and/or -0H), the degree of polymerization of the ester chain ( n) can be varied. Usually, it is desirable that the degree of polymerization is within 5. This is n
This is because if the varnish is larger than 5, the varnish finally obtained will have a high viscosity and will be inconvenient to handle in actual work. The molecular terminal hydroxyl group oligoester imide (4) thus obtained is then converted into diallyl ester (B).
By alcohol rinsing as described above, a solvent-free varnish containing the unsaturated esterimide of the present invention as a main ingredient can be produced.

Although this solvent-free varnish can be put to practical use for now, it can be used for the purpose of adjusting the physical properties of the cured product (for example, imparting flexibility), improving the varnish properties, and increasing its weight. It is possible to blend vinyl monomers. As the monomer, those having one or more polymerizable unsaturated groups in the molecule can be used, and in particular, N-vinyl-2-pyrrolidone, glycidyl (meth)acrylate, allyl glycidyl ether, hydroxyalkyl (meth)acrylate, Those having a high boiling point and high polarity, such as triallyl trimellitate and triallyl isocyanurate, are preferred because they dissolve the unsaturated esterimide well and the resulting varnish is odorless. The varnish produced by the method of the present invention can be radically polymerized and cured,
For example, one or more kinds of polymerization initiators (for example, benzoyl peroxide, dicumyl peroxide, cumene hydroperoxide, tert-butyl peroxide, etc.) are usually added in an amount of 0.5 to 5 parts by weight.
A good cured product can be obtained by heating to 180°C. Furthermore, the varnish can be cured by irradiation with ultraviolet rays or electron beams. The cured varnish has excellent heat resistance, has a long pot life, and is odorless and has a favorable wave effect. The method of the present invention will be further explained in detail in Examples below.

[Example 1] 1 mol of trimellitic anhydride (1929
), diaminodiphenylmethane 0.5 mol (1009)
When a large excess of ethylene glycol (about 8009) was charged and the temperature was raised to 140 to 160°C over about 2 hours, the contents became a deep yellow slurry due to the production of imidodicarphonic acid.

Next, add about 0.059 of tetrabutyl titanate 19
When the temperature rises to 0 to 200°C and the produced water is distilled off as an azeotrope of ethylene glycol, the contents gradually become transparent.
After the contents become completely transparent, when the contents are cooled, a pale yellowish white precipitate of bishydroxyethyldiimide compound is formed. After separating this precipitate, it is washed several times with acetone and air-dried. The thus obtained molecular terminal hydroxyl group esterimide compound 0.1
mol (63.4) 9, diallylisophthalate 0.4 mol (98.59), hydroquinone 0.4 g and paraxylene sulfonic acid 0.89 in the same 0.314 as above.
The mixture is charged into a flask and gradually heated to 170 to 200°C, at which time allyl alcohol is observed to be produced, and this is distilled out of the system. The reaction is completed when the deallyl alcoholization exceeds the theoretical amount of about 98 (Ff). The varnish thus obtained consists of 68% unsaturated imide resin and 32% diallylisophthalate, and when heated to 60 to 100°C, it has good fluidity and is odorless.

The above varnish with 1% by weight of dicumyl peroxide added as a polymerization catalyst was poured into an aluminum shear and heated to 150°C.
It was cured for 8 hours.

The weight loss rate of the cured product after heating at 220° C. for 150 hours is about 1.2%, and it has extremely excellent heat resistance. Further, the catalyst-added varnish exhibits fluidity for 10 days at 80°C, and has a sufficient pot life.

[Example 2] Molecular terminal hydroxyl group esterimide compound obtained in Example 1 0
．． 1 mol (63.49) of bishydroxyethyl isophthalate, 0.1 mol (25.49) of bishydroxyethyl isophthalate and 0.259 of paraxylene sulfonic acid as in Example 1.
After charging into a flask and gradually raising the temperature to uniformly dissolve the
At ~200°C, 90% or more of the theoretical amount (1 mono(c)) of ethylene glycol is distilled out of the system to obtain an oligoesterimide compound with a hydroxyl group at the molecular terminal.

Next, 5 moles (1239) of diallylisophthalate, 0.59 of hydroquinone, and 0.259 of lead acetate were added, and deallyl alcoholization of 98% or more of the theoretical amount (2 moles) was carried out at 200° C. to complete the reaction. The varnish produced by this method has an unsaturated esterimide resin content of 62%.
, a diallylisophthalate content of 3801), and the varnish is odorless and exhibits good fluidity at 40 to 70°C.

A mixture of the above varnish and 1% by weight of dicumyl peroxide as a polymerization catalyst was poured into an aluminum shear.
Cure for 8 hours.

The weight loss rate of the cured product after heating at 220'C for 150 hours was approximately 1.8%, indicating extremely excellent heat resistance. Further, the catalyst-added varnish exhibits fluidity for 17 days at 50°C, and has a sufficient pot life. [Example 3] N- was added to 100 parts by weight of the solvent-free varnish produced in Example 1.
12.7 parts by weight of vinyl-2-pyrrolidone was added to form a solvent-free varnish.

The varnish contains 55% by weight of an unsaturated esterimide resin, is odorless, and exhibits sufficient workability when heated to 35 to 50°C. The above varnish to which 0.5% by weight of digyl peroxide was added as a polymerization catalyst was poured into an aluminum shear and cured at 150°C for 8 hours.

The weight loss rate of the cured product after heating at 220° C. for 150 hours was 2.1%, indicating that it has extremely good heat resistance. Further, the catalyst-added varnish has a long pot life of 13 days at 40°C. [Comparative Example 1] 1 mole of propylene glycol, 0.5 mole of maleic anhydride, and 0.45 mole of phthalic anhydride were esterified by a conventional method to obtain an unsaturated polyester with an acid value of 10.

A varnish was prepared by adding 45 parts by weight of styrene to 55 parts by weight of this polyester resin. The varnish was added with 1% by weight of benzoyl peroxide as a polymerization catalyst, poured into an aluminum shear, and cured at 80°C for 3 hours and then at 130°C for 5 hours. The weight loss of the cured product after heating at 200° C. for 150 hours was 11.8 (fl). The pot life of the catalyzed varnish was 5 days at 30°C and 1 day at 50°C. Furthermore, this varnish emits a significant styrene monomer odor. As described above, the solvent-free varnish produced by the method of the present invention is odorless, has a long pot life, and the cured product obtained has extremely good heat resistance, making it an industrial consideration. This is a large one.

Claims (1)

[Claims] 1. By reacting 1 mole of an oligoesterimide compound with a hydroxyl group at the end of the molecule with about 2 to 10 moles of a diallyl ester compound, the general formula ▲mathematical formula, chemical formula,
There are tables, etc. ▼ Heat-resistant solvent-free varnish made of an unsaturated esterimide compound represented by the formula (where R_1 is a residue of a dibasic acid and X is a residue of an oligoesterimide compound with a hydroxyl group at the end of the molecule) as a main ingredient. manufacturing method.