High-adhesion alkyd resin and preparation method thereof

Abstract

The invention belongs to the field of alkyd resin, and particularly relates to alkyd resin with high adhesive force and a preparation method thereof. The high-adhesion alkyd resin is prepared from soya oil acid, a nitrogen-containing heterocyclic compound, phthalic anhydride, pentaerythritol and hydroxyl-terminated polydimethylsiloxane. By introducing a nitrogen-containing heterocyclic compound (such as quinoline and triazole) and hydroxyl-terminated polydimethylsiloxane (PDMS), the molecular structure of the alkyd resin is remarkably optimized, so that the alkyd resin is superior to the traditional alkyd resin in the aspects of heat resistance, corrosion resistance, mechanical strength, adhesive force, construction performance and the like. The coating is suitable for the fields of high-temperature anticorrosive coatings, marine coatings, industrial protective coatings and the like, and shows remarkable technical advantages and wide market prospects.

Description

Technical Field

[0001] The invention belongs to the field of alkyd resins, and in particular relates to a high-adhesion alkyd resin and a preparation method thereof. Background Art

[0002] Alkyd resins offer high gloss, good body, low price, readily available raw materials, and ease of application. However, the coating is relatively soft, with poor water and alkali resistance, poor adhesion to some materials, and insufficient flexibility, making it prone to sagging during application.

[0003] To improve the performance of alkyd resins, existing technologies typically employ physical blending or simple modification methods, such as adding inorganic fillers or organosilicon compounds to improve heat resistance and leveling, or introducing polar groups to enhance adhesion. However, these modification methods often struggle to strike a balance between various performance characteristics. For example, improving heat resistance may result in decreased flexibility, while enhancing adhesion may sacrifice drying speed. Furthermore, the modified resins may still suffer from coating powdering and insufficient corrosion resistance during long-term use. Therefore, there is an urgent need for a new alkyd resin that can enhance the overall performance of alkyd resins while maintaining good construction adaptability. Summary of the Invention

[0004] The present invention provides an alkyd resin prepared from soybean oil acid, a nitrogen-containing heterocyclic compound, phthalic anhydride, pentaerythritol, and hydroxyl-terminated polydimethylsiloxane;

[0005] Wherein, the nitrogen-containing heterocyclic compound is at least one of 2,3-quinolinedicarboxylic acid and 1,2,3-triazole-4,5-dicarboxylic acid.

[0006] Preferably, the mass ratio of the soybean oil acid, the nitrogen-containing heterocyclic compound, the phthalic anhydride, the pentaerythritol, and the hydroxyl-terminated polydimethylsiloxane is 35-40:2-8:20-30:15-20:1-3.

[0007] Preferably, the hydroxyl-terminated polydimethylsiloxane.

[0008] The preparation method of the alkyd resin comprises the following steps:

[0009] After adding soybean oil acid, nitrogen-containing heterocyclic compound and phthalic anhydride into the reaction pot, start stirring and mix them evenly, stop stirring, then add pentaerythritol, hydroxyl-terminated polydimethylsiloxane and catalyst into the reaction pot. After adding, close the feeding hole, start stirring and add xylene into the reaction pot, open the reflux valve, turn on the cooling water of the horizontal condenser, heat to 180-190℃, reflux and keep warm for 30 minutes, then slowly heat to 215-225℃ after 30 minutes, keep warm and esterify for 4 hours, start sampling to test viscosity and acid value, until the resin acid value is less than 12mgKOH / g and the viscosity is greater than 80s; cool to below 180℃, add diluent solvent, stir evenly and cool to below 80℃, filter, and pump into a storage tank to obtain alkyd resin.

[0010] Furthermore, the catalyst includes at least one of dibutyltin dilaurate, dibutyltin dichloride, dibutyltin oxide, lithium oxide, lithium acetylacetonate, zirconium oxide or tetramethyl zirconate.

[0011] Furthermore, the mass ratio of the catalyst to the nitrogen-containing heterocyclic compound is 2-8:0.5-0.7.

[0012] Furthermore, the viscosity is tested using a Tu-4 cup test at a temperature of 25°C.

[0013] Furthermore, the dilution solvent includes xylene.

[0014] Beneficial effects of the present invention:

[0015] The present invention significantly optimizes the molecular structure of alkyd resin by introducing nitrogen-containing heterocyclic compounds (such as quinoline and triazole) and hydroxyl-terminated polydimethylsiloxane (PDMS), making it superior to traditional alkyd resin in terms of heat resistance, corrosion resistance, mechanical strength, adhesion and construction performance.

[0016] The rigid conjugated structure of the nitrogen-containing heterocycle significantly improves the corrosion resistance, hardness and adhesion of the paint film. Its polar groups can form strong chemical bonds with the metal surface, making the coating adhesion reach the highest level 0 standard. At the same time, the introduction of hydroxyl-terminated PDMS not only improves the leveling of the resin and eliminates orange peel defects, but also greatly improves the thermal stability through the synergistic effect of the molecular structure, significantly increases the thermal decomposition temperature, and ensures that the paint film still maintains excellent mechanical properties in high temperature environments. In addition, the optimized design also accelerates the drying rate and improves construction efficiency. This innovative resin with both weather resistance, protection and processability is suitable for high-temperature anti-corrosion coatings, marine coatings and industrial protective coatings, showing significant technical advantages and broad market prospects. DETAILED DESCRIPTION

[0017] The present invention is described in detail below with reference to the embodiments.

[0018] Example 1

[0019] After adding soybean oil acid, 1,2,3-triazole-4,5-dicarboxylic acid, and phthalic anhydride into the reaction pot, stir and mix thoroughly, stop stirring, then add pentaerythritol, hydroxyl-terminated polydimethylsiloxane, and dibutyltin dilaurate into the reaction pot. After adding, close the feeding port, stir and add xylene into the reaction pot, open the reflux valve, turn on the cooling water of the horizontal condenser, raise the temperature to 183-185℃ and reflux for 30 minutes, then slowly raise the temperature to 219-222℃ after 30 minutes, keep it warm for esterification for 4 hours, start sampling to test viscosity and acid value, until the resin acid value is less than 12mgKOH / g and the coating-4 cup test viscosity is 82-84, cool to below 180℃, add xylene, stir evenly and cool to below 80℃, filter, and pump into a storage tank to obtain an alkyd resin with a solid content of 50%. The mass fractions of the raw materials involved in this embodiment are shown in Table 1 below:

[0020] Table 1

[0021]

[0022] Example 2

[0023] The difference between Example 2 and Example 1 is only the raw material composition (specifically shown in Table 2 below), and the rest is the same as Example 1.

[0024] Table 2

[0025] raw material Mass fraction Soybean oil 35 1,2,3-Triazole-4,5-dicarboxylic acid 4 Phthalic anhydride 25 Pentaerythritol 15 Hydroxyl-terminated polydimethylsiloxane 2 Dibutyltin dilaurate 0.6

[0026] Example 3

[0027] The difference between Example 3 and Example 1 is only the raw material composition (specifically shown in Table 3 below), and the rest is the same as Example 1.

[0028] Table 3

[0029] raw material Mass fraction Soybean oil 35 1,2,3-Triazole-4,5-dicarboxylic acid 6 Phthalic anhydride 25 Pentaerythritol 15 Hydroxyl-terminated polydimethylsiloxane 2 Dibutyltin dilaurate 0.6

[0030] Example 4

[0031] The difference between Example 4 and Example 1 is only the raw material composition (specifically shown in Table 4 below), and the rest is the same as Example 1.

[0032] Table 4

[0033] raw material Mass fraction Soybean oil 35 1,2,3-Triazole-4,5-dicarboxylic acid 8 Phthalic anhydride 25 Pentaerythritol 15 Hydroxyl-terminated polydimethylsiloxane 2 Dibutyltin dilaurate 0.6

[0034] Example 5

[0035] The difference between Example 5 and Example 4 is that the nitrogen-containing heterocyclic compound is 2,3-quinolinedicarboxylic acid, and the rest is the same as Example 1.

[0036] Example 6

[0037] The difference between Example 6 and Example 1 is only the raw material composition (specifically shown in Table 5 below), and the rest is the same as Example 1.

[0038] Table 5

[0039] raw material Mass fraction Soybean oil 40 1,2,3-Triazole-4,5-dicarboxylic acid 6 Phthalic anhydride 20 Pentaerythritol 20 Hydroxyl-terminated polydimethylsiloxane 3 Lithium acetylacetonate 0.7

[0040] Example 7

[0041] The difference between Example 7 and Example 1 is only the raw material composition (specifically shown in Table 6 below), and the rest is the same as Example 1.

[0042] Table 6

[0043] raw material Mass fraction Soybean oil 35 2,3-Quinolinedicarboxylic acid 3 Phthalic anhydride 30 Pentaerythritol 16 Hydroxyl-terminated polydimethylsiloxane 2 Tetramethyl zirconate 0.7

[0044] Comparative Example 1

[0045] The difference between Comparative Example 1 and Example 1 is that no nitrogen-containing heterocyclic compound is added, and the other steps are the same as Example 1.

[0046] Comparative Example 2

[0047] The difference between Comparative Example 1 and Example 1 is the raw material composition (specifically shown in Table 7 below), and the rest is the same as Example 1.

[0048] Table 7

[0049] raw material Mass fraction Soybean oil 35 2,3-Quinolinedicarboxylic acid 9 Phthalic anhydride 25 Pentaerythritol 15 Hydroxyl-terminated polydimethylsiloxane 2 Dibutyltin dilaurate 0.6

[0050] Comparative Example 3

[0051] The difference between Comparative Example 1 and Example 1 is that no nitrogen-containing heterocyclic compound and hydroxyl-terminated polydimethylsiloxane are added, and the other steps are the same as Example 1.

[0052] Effect Examples

[0053] To compare and illustrate the performance of the alkyd resins prepared in the various embodiments of the present invention and the comparative examples, a varnish was prepared by adding appropriate amounts of cobalt isooctanoate and xylene to the resin. The varnish had a solids content of 38% and the cobalt isooctanoate was added in an amount of 0.1wt% based on the resin solids. The varnish was then coated on a standard tinplate surface (dry film thickness of 55-55.8 μm) and left at room temperature for 7 days before performance testing. The test results are shown in Table 8.

[0054] Table 8

[0055]

[0056] Table 8 shows the film-forming properties of alkyd resins. Comparative Examples 1 and 3 show that the introduction of nitrogen-containing heterocyclic compounds and hydroxyl-terminated polydimethylsiloxane into the molecular chain of alkyd resins effectively improves the corrosion resistance, adhesion, hardness, and thermal stability of the alkyd resin paint films, while also shortening the drying time of the paint films. In Comparative Examples 1-4 and 3, the steric hindrance of excessive nitrogen-containing heterocycles inhibits the curing rate, resulting in extended drying times. The rigid structure of the nitrogen-containing heterocycles increases the rigidity of the molecular chain, weakening the leveling properties of the resin and leading to an orange peel appearance in the paint films.

[0057] In summary, the present invention achieves the purpose of improving the corrosion resistance, adhesion, hardness, and thermal stability of the alkyd resin paint film and shortening the drying time of the paint film by introducing an appropriate proportion of nitrogen-containing heterocyclic compounds and hydroxyl-terminated polydimethylsiloxane into the molecular chain of the alkyd resin.

[0058] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A high adhesion alkyd resin, characterized in that: It is prepared from soybean oil acid, nitrogen-containing heterocyclic compounds, phthalic anhydride, pentaerythritol, and hydroxyl-terminated polydimethylsiloxane.

2. The high adhesion alkyd resin according to claim 1, wherein The nitrogen-containing heterocyclic compound is at least one of 2,3-quinolinedicarboxylic acid and 1,2,3-triazole-4,5-dicarboxylic acid.

3. The high adhesion alkyd resin according to claim 1, wherein The mass ratio of the soybean oil acid, the nitrogen-containing heterocyclic compound, the phthalic anhydride, the pentaerythritol and the hydroxyl-terminated polydimethylsiloxane is 35-40:2-8:20-30:15-20:1-3.

4. The method for preparing a high-adhesion alkyd resin according to any one of claims 1 to 3, wherein: The steps include: After adding soybean oil acid, nitrogen-containing heterocyclic compound and phthalic anhydride into the reaction pot, start stirring to mix evenly, stop stirring, then add pentaerythritol, hydroxyl-terminated polydimethylsiloxane and catalyst into the reaction pot. After adding, close the feeding hole, start stirring and add xylene into the reaction pot, open the reflux valve, turn on the cooling water of the horizontal condenser, heat to 180-190℃, reflux and keep warm for 30 minutes, then slowly heat to 215-225℃ after 30 minutes, keep warm and esterify for 4 hours. When the viscosity and acid value of the resin meet the requirements, cool to below 180℃, add diluent solvent, stir evenly and cool to below 80℃, filter, and pump into the storage tank to obtain alkyd resin.

5. The method for preparing a high-adhesion alkyd resin according to claim 4, wherein The catalyst includes at least one of dibutyltin dilaurate, dibutyltin dichloride, dibutyltin oxide, lithium oxide, lithium acetylacetonate, zirconium oxide or tetramethyl zirconate.

6. The method for preparing a high-adhesion alkyd resin according to claim 4, wherein: The mass ratio of the catalyst to the nitrogen-containing heterocyclic compound is 2-8:0.5-0.

7.

7. The method for preparing a high-adhesion alkyd resin according to claim 4, wherein: The viscosity and acid value of the resin meet the requirements: the acid value is less than 12 mgKOH / g, and the viscosity is greater than 80s.

8. The method for preparing a high-adhesion alkyd resin according to claim 4, wherein: The letdown solvent includes xylene.

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