A high-adhesion alkyd resin and its preparation method

Abstract

The application belongs to the field of alkyd resin, and particularly relates to a high-adhesion alkyd resin and a preparation method thereof. The high-adhesion alkyd resin is prepared from soybean oil acid, a nitrogen-containing heterocyclic compound, phthalic anhydride, pentaerythritol and hydroxyl-terminated polydimethylsiloxane. By introducing the nitrogen-containing heterocyclic compound (such as quinoline and triazole) and the hydroxyl-terminated polydimethylsiloxane (PDMS), the molecular structure of the alkyd resin is significantly optimized, so that the alkyd resin is superior to the traditional alkyd resin in terms of heat resistance, corrosion resistance, mechanical strength, adhesion and construction performance. The alkyd resin is suitable for the fields of high-temperature anticorrosive paint, ship paint and industrial protective paint, and exhibits significant technical advantages and broad market prospects.

Description

Technical Field

[0001] This invention belongs to the field of alkyd resins, and specifically relates to a high-adhesion alkyd resin and its preparation method. Background Technology

[0002] Alkyd resins are characterized by high gloss, good fullness, low price, and readily available raw materials, and are easy to apply. However, the coating film 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 balance various properties simultaneously. For instance, improving heat resistance may lead to decreased flexibility, enhancing adhesion may sacrifice drying rate, and the modified resin may still experience problems such as coating chalking and insufficient corrosion resistance during long-term use. Therefore, there is an urgent need for a novel alkyd resin that can both improve the overall performance of alkyd resins and maintain good application adaptability. Summary of the Invention

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

[0005] 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 soybean oil acid, nitrogen-containing heterocyclic compound, phthalic anhydride, pentaerythritol, and hydroxyl-terminated polydimethylsiloxane is 35-40:2-8:20-30:15-20:1-3.

[0007] Preferably, the hydroxyl-terminated polydimethylsiloxane is used.

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

[0009] After adding soybean oil acid, nitrogen-containing heterocyclic compounds, and phthalic anhydride to the reaction vessel, stir and mix thoroughly. Then stop stirring and add pentaerythritol, hydroxyl-terminated polydimethylsiloxane, and catalyst to the reaction vessel. After adding all the ingredients, close the feed hole, start stirring, and add xylene to the reaction vessel. Open the reflux valve and turn on the horizontal condenser cooling water. Raise the temperature to 180-190°C and reflux for 30 minutes. After another 30 minutes, slowly raise the temperature to 215-225°C and esterify for 4 hours. Then start sampling to test the viscosity and acid value until the resin acid value is less than 12 mg KOH / g and the viscosity is greater than 80 s. Cool down to below 180°C, add diluent, stir evenly, cool down to below 80°C, filter, and pump into the storage tank to obtain alkyd resin.

[0010] Furthermore, the catalyst comprises at least one of dibutyltin dilaurate, dibutyltin dichloro, 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 was measured using a Forecast-4 cup test at a temperature of 25°C.

[0013] Furthermore, the diluent includes xylene.

[0014] The beneficial effects of this invention are:

[0015] This 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 workability.

[0016] The rigid conjugated structure of nitrogen-containing heterocyclic compounds significantly enhances the corrosion resistance, hardness, and adhesion of the coating film. Its polar groups can form strong chemical bonds with the metal surface, enabling the coating adhesion to reach the highest grade 0 standard. Simultaneously, the introduction of hydroxyl-terminated PDMS not only improves resin leveling and eliminates orange peel defects but also significantly enhances thermal stability through the synergistic effect of the molecular structure, resulting in a marked increase in thermal decomposition temperature and ensuring that the coating film maintains excellent mechanical properties even at high temperatures. Furthermore, this optimized design accelerates the drying rate and improves application efficiency. This innovative resin, combining weather resistance, protection, and processability, is suitable for high-temperature anti-corrosion coatings, marine coatings, and industrial protective coatings, demonstrating significant technological advantages and broad market prospects. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the embodiments.

[0018] Example 1

[0019] Soybean oleic acid, 1,2,3-triazole-4,5-dicarboxylic acid, and phthalic anhydride were added to the reaction vessel, and the mixture was stirred until homogeneous. Stirring was then stopped. Next, pentaerythritol, hydroxyl-terminated polydimethylsiloxane, and dibutyltin dilaurate were added to the reaction vessel. After all additions were completed, the feed port was closed, stirring was started, and xylene was added to the reaction vessel. The reflux valve was opened, and the horizontal condenser was turned on for cooling. The temperature was raised to 183–185°C and refluxed for 30 minutes. After another 30 minutes, the temperature was slowly raised to 219–222°C and held for esterification for 4 hours. Samples were then taken to test the viscosity and acid value until the resin acid value was less than 12 mg KOH / g and the viscosity measured in a Forte 4 cup was 82–84. The temperature was then lowered to below 180°C, xylene was added, and the mixture was stirred until homogeneous. The temperature was then lowered to below 80°C, filtered, and pumped into a storage tank to obtain 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 only difference between Example 2 and Example 1 is the composition of the raw materials (see Table 2 below for details); everything else is the same as in Example 1.

[0024] Table 2

[0025] raw material Number of parts by weight Soybean oil acid 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 only difference between Example 3 and Example 1 is the composition of the raw materials (specific details are shown in Table 3 below), otherwise they are the same as Example 1.

[0028] Table 3

[0029] raw material Number of parts by weight Soybean oil acid 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 only difference between Example 4 and Example 1 is the composition of the raw materials (see Table 4 below for details); everything else is the same as in Example 1.

[0032] Table 4

[0033] raw material Number of parts by weight Soybean oil acid 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, while the rest is the same as in Example 1.

[0036] Example 6

[0037] The only difference between Example 6 and Example 1 is the composition of the raw materials (see Table 5 below for details); everything else is the same as in Example 1.

[0038] Table 5

[0039] raw material Number of parts by weight Soybean oil acid 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 only difference between Example 7 and Example 1 is the composition of the raw materials (see Table 6 below for details); otherwise, they are the same as in Example 1.

[0042] Table 6

[0043] raw material Number of parts by weight Soybean oil acid 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 was added; otherwise, they are the same as in Example 1.

[0046] Comparative Example 2

[0047] The difference between Comparative Example 1 and Example 1 lies in the composition of raw materials (specific details are shown in Table 7 below), while the rest is the same as Example 1.

[0048] Table 7

[0049] raw material Number of parts by weight Soybean oil acid 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 were added; otherwise, they are the same as in Example 1.

[0052] Example of effect

[0053] To compare and illustrate the performance of the alkyd resins prepared in the various embodiments and comparative examples of this invention, an appropriate amount of cobalt isooctanoate and xylene were added to the resin to prepare a varnish. The solid content of the varnish was 38%, and the amount of cobalt isooctanoate added was 0.1 wt% of the solid portion of the resin. The varnish was coated on the surface of a standard tinplate (dry film thickness of 55-55.8 μm), and its performance was tested after being placed at room temperature for 7 days. 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 introducing nitrogen-containing heterocyclic compounds and hydroxyl-terminated polydimethylsiloxanes into the molecular chain of alkyd resins effectively improves the corrosion resistance, adhesion, hardness, and thermal stability of the alkyd resin film, while also shortening the drying time. Comparative Examples 1-4 and Comparative Example 3 show that the steric hindrance effect of excessive nitrogen-containing heterocycles inhibits the curing rate, leading to prolonged drying time. The rigid structure of the nitrogen-containing heterocycles increases the rigidity of the molecular chain, weakening the resin's leveling properties, and consequently causing an orange peel appearance in the film.

[0057] In summary, this invention improves the corrosion resistance, adhesion, hardness, and thermal stability of alkyd resin coatings and shortens the drying time by introducing an appropriate proportion of nitrogen-containing heterocyclic compounds and hydroxyl-terminated polydimethylsiloxanes into the molecular chain of alkyd resins.

[0058] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A high adhesion alkyd resin, characterized in that, The high adhesion alkyd resin is prepared by using soy oil acid, nitrogen-containing heterocyclic compound, phthalic anhydride, pentaerythritol and hydroxyl-terminated polydimethylsiloxane. The nitrogen-containing heterocyclic compound is at least one of 2,3-quinoline dicarboxylic acid and 1,2,3-triazole-4,5-dicarboxylic acid. The mass ratio of the soy oil acid, nitrogen-containing heterocyclic compound, phthalic anhydride, pentaerythritol and hydroxyl-terminated polydimethylsiloxane is 35-40:2-8:20-30:15-20:1-3. The preparation method of the high adhesion alkyd resin comprises the following steps: the soy oil acid, nitrogen-containing heterocyclic compound and phthalic anhydride are put into a reaction kettle, and then stirring is started and stopped; then the pentaerythritol, hydroxyl-terminated polydimethylsiloxane and catalyst are put into the reaction kettle, and then the feeding hole is closed, stirring is started, dimethylbenzene is put into the reaction kettle, the reflux valve is opened, the cooling water of the horizontal condenser is started, the temperature is raised to 180-190 DEG C for refluxing and keeping for 30 min, then the temperature is slowly raised to 215-225 DEG C for keeping for 4 h of esterification, and then the viscosity and acid value of the resin meet the requirements; then the temperature is lowered to below 180 DEG C, the dilute solvent is added, stirring is started, the temperature is lowered to below 80 DEG C, filtration is carried out, the pump is used to pump into a storage tank, and the alkyd resin is obtained. The catalyst comprises at least one of dibutyltin dilaurate, dichlorodibutyltin, dibutyltin oxide, lithium oxide, lithium acetylacetonate, zirconium oxide or zirconium acid tetramethyl ester. The mass ratio of the catalyst and nitrogen-containing heterocyclic compound is 2-8:0.5-0.

7.

2. The high adhesion alkyd resin according to claim 1, wherein The viscosity and acid value of the resin meet the requirements, i.e. the acid value is less than 12 mgKOH / g, and the viscosity is greater than 80 s.

3. The high adhesion alkyd resin according to claim 2, wherein The dilute solvent comprises dimethylbenzene. The dilute solvent comprises dimethylbenzene.

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