JPS5931528B2 - Manufacturing method of heat-resistant alkyd resin - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for producing alkyd resins.

More specifically, the present invention relates to a method for producing an imide-modified alkyd resin with excellent heat resistance by introducing an imide ring into the molecule through a continuous series of reactions. In general, alkyd resins are obtained by the reaction of vegetable oils, polyhydric alcohols, and dicarboxylic acids. Typically, linseed oil fatty acids, soybean oil fatty acids, dehydrated castor oil fatty acids, etc. are used as the vegetable oils, and polyhydric alcohols are used. Examples include glycerin, pentaerythritol, or trimethylolpropane, and dicarboxylic acids such as phthalic anhydride.

However, although coating films using conventional alkyd resins with these structures do have excellent film properties at room temperature, they have poor heat resistance and deteriorate rapidly at high temperatures, so they cannot be used for long periods at high temperatures. It had the disadvantage that it could not be tolerated.
On the other hand, there are alkyd resins with improved heat resistance using isophthalic acid as the dicarboxylic acid and tris(2-hydroxyethyl) isocyanurate (THEIC) as the polyhydric alcohol, but recent trends include miniaturization of equipment, As demand for even higher heat resistance increases due to improved performance, there is a demand for materials that maintain the excellent coating properties of conventional alkyd resins and exhibit even higher heat resistance. Conventionally, such heat-resistant resins include polyester resins and alkyd resins containing imide rings, but solvents with high boiling points such as dimethylformamide, dimethylacetamide, or m-cresol are often used to form imide rings. Usually these solvents are removed after the reaction is completed and replaced with many low boiling point solvents, or in this case, it is difficult to completely remove the high boiling point solvents and a small amount remains.

However, these solvents also usually have very high solvency;
When forming a coating film, this often causes defects such as destruction of other materials. Furthermore, as another method for introducing an imide ring, a method is known in which the reaction is performed in separate batches, followed by isolation and purification, but this often causes problems in the process. As a result of repeated research and development in order to improve these shortcomings and meet the above-mentioned needs, the present inventors have developed an alkyd resin by introducing an imide ring into the molecule in one continuous reaction without the presence of a solvent. The present inventors have discovered that an alkyd resin that does not lose its excellent coating properties and has high thermal stability has been completed, and the present invention has been completed.

That is, the gist of the present invention is (1) to react and transesterify vegetable oil and glycerin, (2) to the reaction product,
Add a mixture of trimethic acid anhydride and at least one of an aminocarboxylic acid or a diamine and raise the temperature to form an ester of imidocarboxylic acid and glycerade through imidodicarboxylic acid, and (3) further add a polyhydric alcohol and a dicarboxylic acid. In addition, condensation is carried out at 150 to 240°C.

Examples of the vegetable oil that can be used include linseed oil, soybean oil, Japanese sardine oil, castor oil, bean oil, dehydrated castor oil, and tung oil. Further, as the aminocarboxylic acid, o-, m-, and p-aminobenzoic acid, glycine, β-alanine, and γ-aminopropionic acid can be used. The diamine has the general formula H2N-R-NH2 (where x represents -0-, -CH2-, -SO2- or -S-), -(
CH2)-r] (n is an integer of 2 or more), and these diamines can be used.

Further, examples of the polyhydric alcohol include glycerin, tris(2-hydroxyethyl)isocyanurate,
Trimethylolpropane, pentaerythritol, and the like can be used. Furthermore, the dicarboxylic acids include, for example, phthalic anhydride, methylterephthalic acid, methylisophthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, methyltetrahydrophthalic acid, naditutic acid, methylnadic acid, and succinic acid. , adipic acid, sebacic acid, and the like can be used. In the present invention, the proportion of imidocarboxylic acid in the obtained heat-resistant alkyd resin is preferably between 5 and 60%.

If the amount of imidocarboxylic acid is less than 5%, the heat resistance will not be sufficient, while if it is more than 60%, the heat resistance will be sufficient, but the flexibility and interfacial adhesion of the alkyd resin will be lost. The alkyd resin obtained by the method of the present invention obtained as described above is soluble in common solvents such as xylene, toluene, cellosolve, etc. Therefore, it can be prepared as a solution thereof and mixed with commonly used solvents such as melamine formaldehyde. It can be cured with a resin, urea formaldehyde resin, phenol resol resin, or the like.

For example, alkyd resin 9 obtained by the method of the present invention
0 to 60 parts by weight and 10 parts by weight of melamine formaldehyde resin
By heating the composition with 40 parts by weight to 100 to 200°C, a cured product with excellent heat resistance, acid resistance, solvent resistance, and coating properties can be obtained. Therefore, it can be used in a wide range of applications, such as as a heat-resistant insulating coating for H class motor insulating materials. The present invention will be explained in more detail with reference to Examples below.

Example 1 Flaxseed oil fatty acid 44.99 to glycerin 10.39
(0.112 mol) and benzoic acid 349 (0,0279
220-2 mol) was added, and the temperature was gradually raised in a nitrogen stream to 220-2
The reaction was carried out at 40 C for 1 to 2 hours to complete the transesterification reaction.

Next, the temperature was lowered to 100'C, 3.989 (0.020 mol) of 4,4'-diaminodiphenylmethane and 768f1 (0.040 mol) of trimellitic anhydride were added, and the temperature was raised again. At this time, a small amount of tetraisopropyl titanate was added as a catalyst. After reacting at 200-220°C for several hours, it dissolved and became homogeneous.

At this point, imidocarboxylic acid glycerade ester production is completed. This substance was confirmed by infrared absorption spectrum as shown in the figure. That is, according to the infrared absorption spectrum shown in the figure, it is 2000? The absorption based on the acid near -1 disappears, and the characteristic absorption of imide occurs at 1780CTn-1, and 1720c
Characteristic absorptions of ester and imide appear to overlap near rn-1, and imide absorption is also confirmed near 728 cm-1, suggesting the formation of an imide ring. Tris(2-hydroxyethyl)isocyanurate (THEIC) 8.89 (0.0337
After adding 21.701 moles of isophthalic acid and making it homogeneous, 21.701 moles of isophthalic acid
0.130 mol) was added. After being held at 200°C for 1 hour, the temperature was gradually increased and the reaction was carried out at 220-23°C for about 2 hours, and the temperature was brought to about 100°C, followed by cutting with xylene.

Furthermore, 15 parts of Supervetsukamine J-820 (trade name, Dainippon Ink Co., Ltd.), which is a butylated methylol melamine, was added to 100 parts of the alkyd resin thus obtained and cured at 150°C for 10 hours to obtain a coating film. . This coating is
It was red, transparent, and glossy, and showed excellent flexibility without change in the mandrel bending test (diameter: 3m77!).

Further, no change was observed even after immersion in boiling water for 10 hours. After heating and deteriorating at 220° C. for 250 hours, the thermal weight loss was 7.5%, the appearance was glossy, and there was no change in shape.

Reference Example 1 After adding 29.29 glycerin and 11.99 glycerin to linseed oil fatty acid 89,89 to perform monoglyceritization reaction, adding isophthalic acid 61,29 to 220-24
To 100 parts of the alkyd resin obtained by the reaction at 0°C, 50 parts of a phenol resol resin modified to an oil-soluble type was added and cured.

The coating film was flexible, but
The weight reduction of the product heated and deteriorated for 0 hours was 25%,
It had lost its luster, had cracks, and had lost almost all of its strength. Example 2 Glycerin 7.69 to linseed oil fatty acid 33.2f1
(0.083 mol) benzoic acid 2.69 (0.0213 mol) was added, glyceride was synthesized in the same manner as in Example 1, and 4,4'-diaminodicyclohexylmethane 14
．． 59 (0.073 mol) and trimellitic anhydride 28.1y (0.146 mol) were added at 200-220°C.
After making imidoester with 2000C glycerin 3.2
19 (0.0337 mol) was added, and methyltetrahydrophthalic anhydride 7.809 (0.047 mol) was added, and the mixture was kept at 200° C. for 1 hour and then heated to 220-230° C.
After reacting for about 2 hours at °C, the temperature was lowered to about 100 °C, cut with xylene, and further diluted with methyl cellosolve.

To 100 parts of the obtained alkyd resin, 10 parts of urea-formalin resin was added to obtain a cured coating film. This coating showed excellent flexibility with no change in the mandrel bending test with three diameters. Further, no change was observed even when the sample was left in 10% hydrochloric acid at room temperature for 10 days. After further heating for 220 to 500 hours, the appearance did not lose its luster and the thermal weight loss was 500.
．． 501). Example 3 Glycerin 9.3f1 (
0.101 mol) and benzoic acid 3.19 (0.0254
m-aminobenzoic acid 5.57 f! (0.040
mol) and trimellitic anhydride 7.689 (0.0
40 mol) was added to form an imide ester at 200-220℃, and then at 200℃ trimethylolpropane 4.519(
0.034 mol) was added, and 17.60 g (0.099 mol) of methylnadzic acid anhydride was added, maintained at 200°C for 1 hour, then heated, and reacted at 220 to 230°C for about 2 hours. The temperature was lowered to 100° C., cut with xylene, and further diluted with methyl cellosolve acetate.

To 100 parts of the alkyd resin (solid content) obtained here, add diphenyl ether and cashew timer (kamini).
Add 30 parts of resol resin made from
A coating film was obtained by heating and curing at 50° C. for 15 hours. This coating film was reddish, transparent, and glossy, and showed excellent flexibility without change in the mandrel bending test (diameter 3 m77!).

Further, no change was observed even after immersion in boiling water for 10 hours. After heat deterioration at 220° C. for 250 hours, the thermal weight loss was 3.0%, the appearance was glossy, and there was no change in shape.

Examples 4 to 8 Alkyd resins were synthesized in the same manner as in Example 1, changing the respective compositions and blending ratios as shown in Table 1.

The alkyd resin was obtained by cutting with xylene and then diluting with toluene. The properties of the obtained alkyd resin were as shown in the table. Confirmation of the production of alkyd resin is due to the fact that the main reaction for producing alkyd resin is the esterification reaction of alcohol and acid.
0 to 10)).

Table 2 shows the changes in the acid value of the alkyd resin with respect to the reaction time for each example. In the case of Example 1, changes in oxidation with respect to reaction time are shown in FIG.

Point A, at which the acid value became constant, was defined as the end point of the reaction. Alkyd resins were similarly confirmed in other Examples.

Further, after diluting the alkyd resin in each example with a solvent, the nonvolatile parts were as shown in Table 3. Table 3 also shows the gel time of the alkyd resin at 150°C.

In addition, the object to be painted was a tin plate of 0.211 x 50 mm x 180 mm in all Examples, and after heating and curing 1502C for 10 hours, it was used as a flexibility test sample.

In addition, in all of Examples 2 to 8 above, the production of imide esters could be confirmed by infrared absorption spectra during the process of producing alkyd resins.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an infrared absorption spectrum showing that imidocarboxylic acid glycerade ester is produced in the process of producing a heat-resistant alkyd resin by the method of the present invention, and FIG. FIG. 2 is a diagram showing changes in the acid value of a resin with respect to reaction time.

Claims (1)

[Scope of Claims] 1. Vegetable oil and glycerin are reacted, and a mixture of trimellitic acid anhydride and at least one of an aminocarboxylic acid or a diamine is added to the reaction product and further reacted to produce imidocarboxylic acid and glyceride. 1. A method for producing a heat-resistant alkyd resin, which comprises producing an ester of the following, and then adding a polyhydric alcohol and a dicarboxylic acid and reacting the same. 2. The method for producing a heat-resistant alkyd resin according to claim 1, wherein linseed oil is used as the vegetable oil. 3. The method for producing a heat-resistant alkyd resin according to claim 1, wherein coconut oil is used as the vegetable oil. 4. The method for producing a heat-resistant alkyd resin according to claim 1, wherein soybean oil is used as the vegetable oil. 5. The method for producing a heat-resistant alkyd resin according to any one of claims 1 to 4, wherein aminobenzoic acid is used as the aminocarboxylic acid. 6. The method for producing a heat-resistant alkyd resin according to any one of claims 1 to 5, wherein 4,4'-diaminodiphenylmethane is used as the diamine. 7. The method for producing a heat-resistant alkyd resin according to any one of claims 1 to 5, wherein hexamethylene diamine is used as the diamine. 8. The method for producing a heat-resistant alkyd resin according to any one of claims 1 to 7, wherein tris(2-hydroxyethyl)isocyanurate is used as the polyhydric alcohol. 9. The method for producing a heat-resistant alkyd resin according to any one of claims 1 to 7, wherein glycerin is used as the polyhydric alcohol. 10. The method for producing a heat-resistant alkyd resin according to any one of claims 1 to 9, wherein isophthalic acid is used as the dicarboxylic acid. 11. The method for producing a heat-resistant alkyd resin according to any one of claims 1 to 9, wherein methyltetrahydrophthalic anhydride is used as the dicarboxylic acid. 12. The method for producing a heat-resistant alkyd resin according to any one of claims 1 to 9, wherein methylnadic anhydride is used as the dicarboxylic acid. 13. The method for producing a heat-resistant alkyd resin according to any one of claims 1 to 12, wherein the proportion of imidocarboxylic acid in the heat-resistant alkyd resin is 5 to 60%.