JPH0128059B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a curable resin composition that can be crosslinked and cured to produce an esterimide cured product having excellent properties. In recent years, social demands such as resource saving, energy saving, and pollution-free have become more important, and it has become urgent to meet these demands. In response to such demands, for example, solvent-free coatings and efficient curing methods are being considered for coatings used for electrical insulation. In response to such demands, the present inventors conducted research in search of a resin composition that is solvent-free and has good curability, and as a result, the present invention was achieved. The present invention provides (a) General formula: (In the formula, Indicates the m-valent residue of the ester oligomer that is mol% or less, m is 2 or more and is 1/2 to 1 times the number of terminal hydroxyl groups of the ester oligomer, and n is 1 or 2. 15 to 80 parts by weight of an oligoesterimide compound represented by (representing an integer); (b) general formula: (R ₁ in the formula is a hydrogen atom or a methyl group, R ₂ is

[Formula] or

[Formula] (where R ₃ represents an organic diisocyanate residue), and Y represents a polyol component mainly composed of a dicarboxylic acid component selected from aromatic dicarboxylic acids or derivatives thereof and a fatty acid polyol. 1 of the ester oligomer, in which the trifunctional or higher functional polyol in the polyol component is 20 mol % or less with respect to the dicarboxylic acid component, and the excess amount of the polyol component with respect to the dicarboxylic acid component is 25 mol % or less.
85 to 20 parts by weight of a compound represented by the following formula: 2 or more and 1/2 to 1 times the number of terminal hydroxyl groups of the oligomer. This is a curable resin composition. The composition of the present invention is solid at room temperature, becomes a viscous liquid at a temperature of about 80°C, and becomes a viscous liquid at a temperature of 80 to 130°C.
It becomes a liquid with a viscosity of less than 5000 cP and can be molded at temperatures within this range. Molded products molded at such temperatures can be crosslinked and cured by irradiation with ultraviolet rays or electron beams, or by heat treatment, producing cured products with excellent mechanical properties, electrical properties, and chemical resistance. Obtainable. That is, the composition of the present invention is subjected to ultraviolet irradiation, 1 to 30 Mrad electron beam irradiation, or 200 to 450°C after adding a sensitizer.
It is hardened by heat treatment at a temperature of . This curing is thought to be due to the polymerization of the double bond of the acrylic group, methacrylic group, or allyl group and norbornene group, which are the terminal groups of the compounds represented by formulas () and (). The degree of progress of such a curing reaction can be determined by the ratio of insoluble residue, ie, the gel fraction, when the cured product is treated in m-cresol at 90° C. for 5 hours. The cured product of the composition of the present invention exhibits excellent properties when the gel fraction determined by the above-mentioned determination method is 75% or more, preferably 90% or more, and this gel fraction is 90%. In the case of UV curing, the curing conditions are, for example, an input density of 80W/
When irradiated from a distance of 10 cm using a cm high pressure mercury lamp, it takes about 2 seconds, and in the case of heat curing,
It takes about 2 minutes at a temperature of 250℃. Further, it is also possible to perform curing by combining two or more of the three types of curing methods described above. Among the above-mentioned curing methods, the sensitizers added when curing with ultraviolet rays include benzoyl ether,
Benzoin ethers such as benzoin isopropyl ether and benzoin isobutyl ether, benzophenone, benzophenone derivatives such as methyl orthobenzoyl benzoate, benzanthrone, diphenyl disulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, benzyl dimethyl ketal, etc. can be used, and additives such as amines and ketones can also be added to promote curing by ultraviolet rays.
These sensitizers may be used alone or in combination of two or more, and the amount thereof is preferably 0.1 to 5% by weight based on the composition of the present invention. desirable. It is also desirable to add a polymerization inhibitor to the composition of the present invention in an amount of 0.005 to 0.5% by weight of the composition for thermal stability before curing. Hydroquinone, p-methoxyphenol, N-
Commonly used compounds such as nitrosophenylhydroxylamine and the like can be used. These polymerization inhibitors can generally be used as they are in the production of the composition of the present invention. The oligoester imide compound represented by the formula () contained in the composition of the present invention has a general formula: It is the same as a compound substituted with a group represented by (n in the formula represents an integer of 1 or 2), and the group represented by X in the formula () does not necessarily have to have a uniform structure. . Therefore, m in formula () does not need to be an integer. However, from the viewpoint of the properties of the cured product, it is necessary that the number of groups represented by the formula () per molecule of the compound represented by the formula () is two or more. In addition, in the ester oligomer corresponding to the residue represented by There are lower alkyl esters and acid halides such as terephthalodichloride. In addition to the above-mentioned compounds, non-aromatic carboxylic acids or derivatives thereof may be used as the dicarboxylic acid component.
It can be added in a range of mol% or less. Examples of these carboxylic acids include aliphatic carboxylic acids such as succinic acid, adipic acid, sebacic acid, and the like. The use of non-aromatic carboxylic acids or derivatives thereof in an amount exceeding 20 mol % is undesirable because it causes a decrease in the heat resistance of the cured product. In the above oligoester compound, examples of aliphatic polyols include difunctional alcohols such as ethylene glycol and propylene glycol, trifunctional alcohols such as trimethylolpropane and glycerin, and tetrafunctional alcohols such as pentaerythritol. These aliphatic polyols may be used alone or in combination of two or more. Further, a non-aliphatic polyol such as bisphenol A, cyclohexanedimethanol, trisisohydroxyethyl isocyanurate, etc. may be added to a part of the polyol component. The reason for limiting the excess amount of the polyol component relative to the dicarboxylic acid component in the above ester oligomer is that if the excess amount of the polyol component exceeds 35 mol%, a cured product with excellent properties cannot be obtained. This is thought to be due to the fact that the molecular weight of the cured product is not sufficiently large. However, the limitation on the excess amount mentioned above relates to the excess amount determined by each residue of the ester oligomer, and does not limit the amount charged during synthesis of the ester oligomer or the synthesis method. Further, the method for producing the oligoesterimide compound represented by the formula () is not particularly limited, but the corresponding ester oligomer and the carboxylic acid corresponding to the group represented by the formula (), that is, N
-Carboxymethyl-3,6-endomethylene-
1,2,3,6-tetrahydro-cis-phthalimide or N-β-carboxyethyl-3,6-
Endomethylene-1,2,3,6-tetrahydro-cis-phthalic acid imide (hereinafter referred to as N-carboxymethylnadicimide or N-carboxyethylnadicimide, respectively) in a desired amount with a polymerization inhibitor and dehydration. After adding a catalyst and further adding a small amount of a solvent such as xylene, naphtha, etc., heating and stirring to a temperature of 130 to 160°C, and azeotropically distilling the water produced with the above-mentioned solvent and taking it out of the system. , can be synthesized by removing the solvent.
In this synthesis method, as the polymerization inhibitor, those mentioned above as the polymerization inhibitor added to the composition of the present invention can be used. The amount of the polymerization inhibitor used is 0.005 to 0.5% by weight based on the raw material system as described above. Also, as a dehydration catalyst, tetrabutoxytitanium,
An organic titanate catalyst such as tetraisoproboxytitanium or an acid catalyst such as p-toluenesulfonic acid or dimethylbenzenesulfonic acid may be used in an amount of 0.2 to 2 weight based on the raw material system. Furthermore, in the compound represented by the formula () contained in the composition of the present invention, half or all of the terminal hydroxyl groups of the ester oligomer corresponding to the residue represented by Y are converted into acrylic ester groups, methacrylic groups, or the following formula: CH ₂ = CHCH ₂ OCONH−R ₃ −NHCOO−
Indicates a compound substituted with a group represented by () (R ₃ in the formula is the same as above), and as in the compound represented by the above formula ().
is not necessarily an integer, and it is necessary that the average number of acrylic groups, methacrylic groups, or groups represented by formula () per molecule of the compound represented by formula () is 2 or more. In addition, in the ester oligomer corresponding to the residue represented by Y in formula (), the dicarboxylic acid component and polyol component of the raw materials are the same as in the case of the ester oligomer corresponding to X in formula () above. May be used. Furthermore, the reason for limiting the excess amount of the polyol component to the dicarboxylic acid component in the above ester oligomer is exactly the same as in the case of the ester oligomer corresponding to X in the above formula (). The reason for limiting the amount of the trifunctional or higher functional polyol in the above polyol component is that if the amount of the trifunctional or higher functional polyol used exceeds 20 mol% of the dicarboxylic acid component, the flexibility of the cured product will decrease. Because it gets worse. Furthermore, the method for producing the compound represented by formula () is not particularly limited. In the composition of the present invention, the reason for limiting the blending ratio of the oligoesterimide compound represented by the formula () and the compound represented by the formula () is that the oligoesterimide compound is less than 15 parts by weight and the compound of the formula () is This is because if the amount exceeds 85% by weight, the resulting cured product will not have sufficient properties in terms of hardness, heat resistance, and chemical resistance. If the amount exceeds 20% by weight and the compound of formula () is less than 20% by weight, the viscosity of the resulting curable resin composition will increase, making it necessary to raise the temperature during molding above the above range. This is because there is a risk that a portion of the cured product will be cured by heat before molding, and the flexibility of the cured product, especially when made into a film, will be poor. The method for producing the composition of the present invention from the compound represented by the formula () and the compound represented by the formula () is not particularly limited, but generally, the method for producing the composition of the present invention from the compound represented by the formula () and the compound represented by the formula () is Add the above-mentioned polymerization inhibitor and sensitizer as necessary,
Next, a method is used in which the mixture is heated to a temperature of 80 to 150°C to give it fluidity, stirred, and homogenized. Since the compounds represented by the formulas () and () easily dissolve in each other, the composition of the present invention can be obtained in a very short time. In addition, the compounds of formula () and formula () are respectively X, n, m, Y,
A mixture of different R ₁ , R ₂ , R ₃ , and l may be used. The cured product obtained from the composition of the present invention has hardness,
It has excellent mechanical properties such as flexibility, dielectric breakdown voltage, etc., electrical properties, and chemical properties such as chemical resistance, as well as heat resistance. Since the curable resin composition of the present invention has such characteristics, it is suitable for use as a solvent-free paint for electrical insulation such as a solvent-free varnish for electric wires. However, the use of the composition of the present invention is not limited to electrically insulating paints, and the composition of the present invention can be widely used in general paints and other uses. Next, the present invention will be explained with reference to examples. In the Examples, "parts" means "parts by weight" unless otherwise specified. Further, explanations of abbreviations used in the examples are shown in Table 1. These examples relate to the properties when the composition of the present invention is mainly used as an insulating varnish for electric wires, but the cured film characteristics shown in the examples also indicate that the composition of the present invention may be used for other purposes as well. It has been shown to be quite useful.

【table】

[Table] Examples 1 to 3 Ester oligomers were produced using the raw materials shown in Table 2. The p-/m-ratio in the generated ester oligomer is x, and the ratio of the number of trifunctional polyol residues to the total number of dicarboxylic acid residues is y.
(%), and the excess amount of the polyol component to the dicarboxylic acid component is z (%), and these values are shown in Table 2. ₁ part of this ester oligomer
In addition to ₁ part of Y (abbreviated as ) and ₁ part of xylene Z, a polymerization inhibitor and a dehydration catalyst were weighed into a reaction vessel, and 140
While stirring while heating to a temperature _of Heating and stirring was continued until the temperature reached 160°C, and removal of xylene and completion of the reaction were confirmed by a decrease in weight. As a result of comparing the infrared absorption spectrum of the obtained resinous substance with that of the raw material, it was confirmed that it was an oligoesterimide compound.

【table】

[Table] Next, ester oligomers were produced using the raw materials shown in Table 3. Table 3 shows the x, y, and z values of the ester oligomers produced. ₂ parts of this ester oligomer X and ₂ parts of xylene Z
Weigh out a polymerization inhibitor in addition to the above amount into a reactor, heat it,
Start stirring and after the temperature becomes uniform at 140℃,
Acrylic acid is added while blowing dry air into this solution.
Add ₂ parts of Y and a dehydration catalyst, and react in the same manner as when producing an oligoesterimide compound at a temperature of 140°C while blowing dry air. After the total amount of distilled water reaches W parts, dry air is added. xylene and excess acrylic acid were removed to obtain a resinous material. This substance was confirmed to be an oligoester acrylic ester based on the infrared absorption spectrum and weight change.

【table】

[Table] The amounts shown in Table 4 of the oligoester imide compound and oligoester acrylic ester obtained as described above were weighed into a stirring container, and heated at 140°C.
After stirring the mixture while heating it to a temperature of , the sensitizer shown in Table 4 was added thereto, the mixture was stirred again until the mixture became uniform, and then cooled to obtain a curable resin composition. The obtained curable resin composition is solid at room temperature,
When heated, it melted into a liquid having the viscosity shown in Table 4. Next, in order to investigate the curability of this composition and the properties of the cured product, this composition was heated to the temperature shown in Table 4 and applied to a copper wire with a diameter of 1 mm.
A die with a diameter of 1.12 mmφ is used to create a uniform coating film, and two high-pressure mercury lamps with an input density of 80 W/cm are used to uniformly irradiate each part of the composition from a distance of 10 cm, effectively coating each part. UV rays were irradiated for 2 seconds each to obtain a cured film. The gel fraction and properties of this cured film were measured and the results are shown in Table 5.

[Table] Example 4 A composition in which the composition of Example 1 did not contain benzoyl isopropyl ether was produced in the same manner as in Example 1. Using this composition, a uniform coating film was formed on a copper wire with a diameter of 1 mmφ, and
A uniform hardened film was obtained by processing for 2 minutes in an electric furnace adjusted to a temperature of .degree. The gel fraction and properties of this cured film were measured and the results are shown in Table 5.

The procedure was carried out according to [Table].
Example 5 Synthesized from DMT, DMI, EG, PG, and TMP with a p-/m-ratio of 9/1, an EG residue/PG residue ratio of 10/11, and an amount of TMP relative to DMT and DMI.
Weighed 186 parts of ester oligomer with a polyol excess of 25% and 500 parts of toluene into a reaction vessel, heated to 70°C while flowing nitrogen gas and stirred, and added 87 parts of toluene diisocyanate to the reaction temperature.
Gradually drop it while keeping the temperature below 80℃, continue stirring at this temperature for 2 hours, then add 35 parts of allyl alcohol and
0.6 part of MEHQ was added, and stirring was continued until no absorption of isocyanate groups was observed in the infrared absorption spectrum. The resulting solution was then heated to 120°C,
Toluene and excess allyl alcohol were removed by blowing dry air to obtain a resinous material. The same procedure as in Example 1 was carried out using 30 parts of this resinous substance, 25 parts of the oligoester imide compound used in Example 1, 45 parts of the oligoester acrylic acid ester used in Example 1, and 1 part of benzoin isopropyl ether. A curable resin composition was obtained. This composition was solid at room temperature and liquid with a viscosity of 4000 cP at 100°C. Next, this composition was heated to 120°C and applied uniformly to a 0.2 mm thick stainless steel plate to form a 50 μ thick film, and then applied to the resin coated surface.
A cured film was obtained by irradiating ultraviolet rays for 15 seconds from a distance of 25 cm using a 2KW high-pressure mercury lamp. The hardness of this film was 6H, and no cracks appeared in the film even when bent 180° with the stainless steel plate inside. Further, even when this film was heated at 180° C. for 6 hours and then bent in the same manner, no cracks were generated in the film.

Claims (1)

[Claims] 1 (a) General formula: (In the formula, Indicates the m-valence residue of the ester oligomer that is mol% or less, m is 2 or more and is 1/2 to 1 times the number of terminal hydroxyl groups of the ester oligomer, and n is an integer of 1 or 2. (b) 15 to 80 parts by weight of an oligoesterimide compound represented by the general formula: [In the formula, R ₁ is a hydrogen atom or a methyl group, R ₂ is a group represented by [Formula] or [Formula] (wherein R ₃ is an organic diisocyanate residue), and Y is an aromatic dicarboxylic acid or It is synthesized from a dicarboxylic acid component selected from its derivatives and a polyol component mainly composed of fatty acid polyols, and the polyol component with trifunctional or higher functionality is 20 mol% or less based on the dicarboxylic acid component, and the polyol component is If the excess amount of the component to the above dicarboxylic acid component is
Compounds 85 to 25% by mole of an ester oligomer, where l is 2 or more and is 1/2 to 1 times the number of terminal hydroxyl groups of the oligomer. 20 parts by weight of a curable resin composition.