Preparation process method of high-solid low-viscosity acrylic acid modified alkyd resin

Abstract

According to the invention, the emulsion curing agent which is formed by mixing water-based alkyd resin and acrylic emulsion into a film-forming substance is researched, the influence of the type and dosage of the film-forming substance on the performance of the emulsion curing agent is discussed, and a coating film is tested and characterized. Results show that compared with water-based alkyd resin and acrylic emulsion, the emulsion curing agent is greatly improved in film drying time and salt spray resistance time, and when the addition amount of the acrylic emulsion LR-2052 is 10% (mass fraction, similarly later) and the addition amount of the alkyd resin is 17.5%, the comprehensive performance of a film is optimal, and the film has excellent corrosion resistance. The surface drying time of a coating film does not exceed 0.2 h, the hard drying time does not exceed 18 h, the salt mist resistance time is as long as 200 h, the gloss of a paint surface is 80%, the water resistance time is 180 h, and the impact resistance is 50 kg.cm, which all meet the market requirements.

Description

Technical Field

[0001] This invention belongs to the field of anti-corrosion coating technology, specifically relating to a preparation process of a high-solids, low-viscosity acrylic modified alkyd resin. Background Technology

[0002] In recent years, with increasing emphasis on green environmental protection and physical and mental health, the sales of water-based coatings have been increasing year by year. Traditional solvent-based coatings not only impact the environment, but the solvents are also highly volatile and prone to explosion if improperly stored. During construction, organic solvents can also cause chronic harm to workers and affect the atmosphere. Therefore, many countries have enacted relevant laws and regulations to strictly limit VOC emissions. Water-based coatings have very low emissions of volatile organic compounds, posing minimal harm to the environment and human health. They are also non-flammable, non-explosive, not classified as hazardous chemicals, do not yellow easily, and have good durability. In particular, water-based industrial coatings are becoming one of the development directions gradually replacing traditional solvent-based coatings. Currently, environmentally friendly waterborne industrial coatings can be classified into many types according to their film-forming substances. Among them, industrial coatings using alkyd resins as film-forming substances have strong anti-corrosion and anti-rust capabilities, making them suitable as anti-corrosion primers. However, their main disadvantages are slow drying time, poor weather resistance, and strong odor. Acrylic emulsions, on the other hand, have the advantages of fast drying time, good weather resistance, low odor, and high gloss. However, acrylic emulsions are not as effective as alkyd resins in terms of anti-corrosion and anti-rust capabilities, making them more suitable as anti-corrosion topcoats. To address the advantages and disadvantages of both, this paper presents a hybrid anti-corrosion coating that combines the advantages of both while mitigating their respective drawbacks.

[0003] Hybrid anti-corrosion coatings are coating systems that use two or more base materials mixed together chemically or physically as film-forming substances in industrial coatings. This paper describes the physical hybridization of a self-made waterborne alkyd resin and acrylic emulsion to explore the effects of the type of film-forming substance and different compounding ratios on the film performance of hybrid anti-corrosion coatings. Through formulation optimization, a hybrid anti-corrosion coating with excellent anti-corrosion and rust prevention capabilities and shortened film drying time was prepared, which will be of great significance to promoting the development of waterborne industrial coatings.

[0004] The anti-corrosion mechanisms of anti-corrosion coatings mainly fall into three categories: cathodic protection, shielding protection, and inhibition protection. The anti-corrosion mechanism of the waterborne alkyd resin / acrylic emulsion hybrid anti-corrosion coating studied in this paper is primarily shielding protection. The hybrid anti-corrosion coating forms a dense film that isolates the substrate material from corrosive media, effectively shielding it from corrosive media such as air, water, and acid rain, thus preventing corrosion of the metal material and achieving an anti-corrosion effect. This is the anti-corrosion mechanism of this coating. The waterborne alkyd resin is prepared using the fatty acid method, with linoleic acid as the monobasic acid, NH4OH as the neutralizing agent, and propylene glycol monomethyl ether as the co-solvent, which accelerates the drying time and hardness of previous waterborne alkyd resin coatings. Summary of the Invention

[0005] The purpose of this invention is to modify a self-made alkyd resin with acrylic acid to obtain an anti-corrosion coating, and to explore the influence of the type of film-forming substance and different compounding ratios on the performance of the anti-corrosion coating. Through formulation optimization, a high-solids, low-viscosity acrylic-modified alkyd resin with excellent anti-corrosion ability and shortened film drying time is prepared.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] Step 1: Add linoleic acid, IPA, PA, TMP, and xylene to a four-necked flask, heat to 130-160 ℃, and stir.

[0008] Step 2: After holding at the temperature for 40-70 min, heat to 180-210 ℃ and test the acid value. When the acid value is less than 10 mg KOH / g (resin), evaporate the solvent and cool down to 130-150 ℃.

[0009] Step 3: Add TMA. After the reaction is complete, add the cosolvent propylene glycol monomethyl ether and the neutralizing agent NH4OH. Stir for 30-50 min, then add distilled water and filter to obtain waterborne alkyd resin.

[0010] Step 4: Add water-based alkyd resin to the mixing tank, and add DMEA, drier QD10, anti-settling agent attapulgite, deionized water, dispersant SN-5040, and defoamer Tego-810 in sequence at 500-650 r / min (the drier should be stirred for more than 10 minutes after being added to ensure complete dispersion before adding the anti-settling agent attapulgite).

[0011] Step 5: Add rust-preventive powder zinc phosphate, THR-218 and filler precipitate barium sulfate. Water should be added in batches. After dispersing for 40-60 minutes, grind for 40-60 minutes. Finally, filter out zirconium beads with a filter screen to obtain the initial slurry.

[0012] Step 6: Stir the ground slurry at low speed, and add salt spray resistant agent ZT-719, flash rust inhibitor ZT-706, silicone modified styrene-acrylate copolymer emulsion LR-2052, film-forming aid alcohol ester twelve, scratch resistant aid BYK-410, substrate wetting and leveling agent Tego-270, thickener TT-936 and Haimings 105A (50%) in sequence. After stirring for 30 min, a high solids and low viscosity acrylic modified alkyd resin is obtained.

[0013] The heating temperature in step 1 is 130-160 ℃.

[0014] In step 2, the heat preservation time is 40-70 min, the heating temperature is 180-210 ℃, and the temperature is cooled to 130-150 ℃.

[0015] The stirring time in step 3 is 30-50 minutes.

[0016] In step 4, the stirring rate is 500-650 r / min.

[0017] In step 5, the dispersion time is 40-60 min and the grinding time is 40-60 min.

[0018] The drying agent is QD10, the dispersant is SN-5040, the defoamer is Tego-810, the titanium dioxide is THR-218, the precipitated barium sulfate is 800 mesh, the flash rust inhibitor is ZT-706, the waterborne styrene-acrylate copolymer emulsion is LR-2052, the scratch-resistant additive is BYK-410, the substrate wetting and leveling agent is Tego-270, and the alkali-swelling thickener is TT-936.

[0019] Beneficial effects

[0020] This invention discloses a waterborne alkyd resin / acrylic emulsion curing agent. Because the hybrid anti-corrosion coating with added alkyd resin has a denser film than that of a single acrylic emulsion, it better isolates the substrate from external water and air, providing a shielding effect. Its salt spray resistance time can reach 200 hours, significantly improving the shortcomings of acrylic emulsion anti-corrosion coatings in salt spray resistance. The surface drying time of the hybrid anti-corrosion coating is 0.2 hours, and the complete drying time is 18 hours, shortening the drying time of the film of a single waterborne alkyd resin anti-corrosion coating. This is because the film-forming mechanism of acrylic emulsion is physical evaporation, that is, the direct evaporation of water. In contrast, the film-forming mechanism of waterborne alkyd resin, in addition to physical evaporation, also requires an oxidative cross-linking reaction with oxygen in the air, which is oxidative drying. Therefore, the drying speed of acrylic emulsion is much faster than that of waterborne alkyd resin. Thus, the drying speed of the hybrid anti-corrosion coating film is faster than that of a single alkyd resin.

[0021] The coating film flexibility is ≤1, an improvement over single alkyd resins; the surface gloss (60°) reaches 80%, between that of waterborne alkyd resins and acrylic emulsions, meeting the requirements of most fields; water resistance reaches 180 h, impact resistance reaches 50 kg·cm, adhesion is grade 1, and flash rust inhibition is normal. Therefore, hybrid anti-corrosion coatings can fully combine the advantages of both waterborne alkyd resins and acrylic emulsions. Attached Figure Description

[0022] Figure 1 The film-forming mechanism of waterborne alkyd resin. Detailed Implementation

[0024] To make the process and technical solution of this invention clearer, the process of this invention will be further described in detail below.

[0025] Example 1:

[0026] (1) Add linoleic acid, IPA, PA, TMP and xylene to a four-necked flask, heat to 140 °C and stir;

[0027] (2) After holding at the temperature for 50 min, heat to 180 °C and test the acid value. When the acid value is less than 10 mg KOH / g (resin), evaporate the solvent and cool down to 130 °C.

[0028] (3) Add TMA, and after the reaction is complete, add the cosolvent propylene glycol monomethyl ether and the neutralizing agent NH4OH. Stir for 30 min, then add distilled water and filter to obtain waterborne alkyd resin.

[0029] (4) Add waterborne alkyd resin to the mixing tank, and add DMEA, drier QD10, anti-settling agent attapulgite, deionized water, dispersant SN-5040, and defoamer Tego-810 in sequence at 500 r / min (the drier should be stirred for more than 10 minutes after being added to ensure complete dispersion, and then the anti-settling agent attapulgite should be added).

[0030] (5) Add rust-preventive powder zinc phosphate, THR-218 and filler precipitate barium sulfate. Water should be added in batches. After dispersing for 40 minutes, start grinding for 40 minutes. Finally, filter out zircon beads with a filter screen to obtain the initial slurry.

[0031] (6) Stir the ground slurry at low speed, and add salt spray resistant agent ZT-719, flash rust inhibitor ZT-706, silicone modified styrene-acrylate copolymer emulsion LR-2052, film-forming aid alcohol ester twelve, scratch resistant aid BYK-410, substrate wetting and leveling agent Tego-270, thickener TT-936 and Haimingsi 105A (50%) in sequence. After stirring for 30 min, a high solids and low viscosity acrylic modified alkyd resin is obtained.

[0032] Example 2:

[0033] (1) Add linoleic acid, IPA, PA, TMP and xylene to a four-necked flask, heat to 150 °C and stir;

[0034] (2) After holding at the temperature for 70 min, heat to 190 °C and test the acid value. When the acid value is less than 10 mg KOH / g (resin), evaporate the solvent and cool down to 150 °C.

[0035] (3) Add TMA. After the reaction is complete, add the cosolvent propylene glycol monomethyl ether and the neutralizing agent NH4OH. Stir for 40 min, add distilled water and filter to obtain waterborne alkyd resin.

[0036] (4) Add waterborne alkyd resin to the mixing tank, and add DMEA, drier QD10, anti-settling agent attapulgite, deionized water, dispersant SN-5040, and defoamer Tego-810 in sequence at 550 r / min (the drier should be stirred for more than 10 minutes after being added to ensure complete dispersion, and then the anti-settling agent attapulgite should be added).

[0037] (5) Add rust-preventive powder zinc phosphate, THR-218 and filler precipitate barium sulfate. Water should be added in batches. After dispersing for 50 min, start grinding for 50 min. Finally, filter out zircon beads with a filter screen to obtain the initial slurry.

[0038] (6) Stir the ground slurry at low speed, and add salt spray resistant agent ZT-719, flash rust inhibitor ZT-706, silicone modified styrene-acrylate copolymer emulsion LR-2052, film-forming aid alcohol ester twelve, scratch resistant aid BYK-410, substrate wetting and leveling agent Tego-270, thickener TT-936 and Haimingsi 105A (50%) in sequence. After stirring for 30 min, a high solids and low viscosity acrylic modified alkyd resin is obtained.

[0039] Example 3:

[0040] (1) Add linoleic acid, IPA, PA, TMP and xylene to a four-necked flask, heat to 130 °C and stir;

[0041] (2) After holding at the temperature for 40 min, heat to 200 °C and test the acid value. When the acid value is less than 10 mg KOH / g (resin), evaporate the solvent and cool down to 140 °C.

[0042] (3) Add TMA, and after the reaction is complete, add the cosolvent propylene glycol monomethyl ether and the neutralizing agent NH4OH. Stir for 35 min, then add distilled water and filter to obtain waterborne alkyd resin.

[0043] (4) Add waterborne alkyd resin to the mixing tank, and add DMEA, drier QD10, anti-settling agent attapulgite, deionized water, dispersant SN-5040, and defoamer Tego-810 in sequence at 600 r / min (the drier should be stirred for more than 10 minutes after being added to ensure complete dispersion, and then the anti-settling agent attapulgite is added).

[0044] (5) Add rust-preventive powder zinc phosphate, THR-218 and filler precipitate barium sulfate. Water should be added in batches. After dispersing for 60 min, start grinding for 60 min. Finally, filter out zircon beads with a filter screen to obtain the initial slurry.

[0045] (6) Stir the ground slurry at low speed, and add salt spray resistant agent ZT-719, flash rust inhibitor ZT-706, silicone modified styrene-acrylate copolymer emulsion LR-2052, film-forming aid alcohol ester twelve, scratch resistant aid BYK-410, substrate wetting and leveling agent Tego-270, thickener TT-936 and Haimingsi 105A (50%) in sequence. After stirring for 30 min, a high solids and low viscosity acrylic modified alkyd resin is obtained.

[0046] Example 4:

[0047] (1) Add linoleic acid, IPA, PA, TMP and xylene to a four-necked flask, heat to 160 °C and stir;

[0048] (2) After holding at the temperature for 60 min, heat to 210 °C and test the acid value. When the acid value is less than 10 mg KOH / g (resin), evaporate the solvent and cool down to 140 °C.

[0049] (3) Add TMA, and after the reaction is complete, add the cosolvent propylene glycol monomethyl ether and the neutralizing agent NH4OH. Stir for 50 min, then add distilled water and filter to obtain waterborne alkyd resin.

[0050] (4) Add waterborne alkyd resin to the mixing tank, and add DMEA, drier QD10, anti-settling agent attapulgite, deionized water, dispersant SN-5040, and defoamer Tego-810 in sequence at 650 r / min (the drier should be stirred for more than 10 minutes after being added to ensure complete dispersion, and then the anti-settling agent attapulgite is added).

[0051] (5) Add rust-preventive powder zinc phosphate, THR-218 and filler precipitate barium sulfate. Water should be added in batches. After dispersing for 45 minutes, start grinding for 45 minutes. Finally, filter out zircon beads with a filter screen to obtain the initial slurry.

[0052] (6) Stir the ground slurry at low speed, and add salt spray resistant agent ZT-719, flash rust inhibitor ZT-706, silicone modified styrene-acrylate copolymer emulsion LR-2052, film-forming aid alcohol ester twelve, scratch resistant aid BYK-410, substrate wetting and leveling agent Tego-270, thickener TT-936 and Haimingsi 105A (50%) in sequence. After stirring for 30 min, a high solids and low viscosity acrylic modified alkyd resin is obtained.

Claims

1. A preparation process for a high-solids, low-viscosity acrylic-modified alkyd resin, characterized in that: The steps are as follows: Step 1: Add linoleic acid, IPA, PA, TMP, and xylene to a four-necked flask, heat to 130-160 ℃, and stir. Step 2: After holding at the temperature for 40-70 min, heat to 180-210 ℃ and test the acid value. When the acid value is less than 10 mg KOH / g (resin), evaporate the solvent and cool down to 130-150 ℃. Step 3: Add TMA. After the reaction is complete, add the cosolvent propylene glycol monomethyl ether and the neutralizing agent NH4OH. Stir for 30-50 min, then add distilled water and filter to obtain waterborne alkyd resin. Step 4: Add water-based alkyd resin to the mixing tank, and add DMEA, drier QD10, anti-settling agent attapulgite, deionized water, dispersant SN-5040, and defoamer Tego-810 in sequence at 500-650 r / min (the drier should be stirred for more than 10 minutes after being added to ensure complete dispersion before adding the anti-settling agent attapulgite). Step 5: Add rust-preventive powder zinc phosphate, THR-218 and filler precipitate barium sulfate. Water should be added in batches. After dispersing for 40-60 minutes, grind for 40-60 minutes. Finally, filter out zirconium beads with a filter screen to obtain the initial slurry. Step 6: Stir the ground slurry at low speed, and add salt spray resistant agent ZT-719, flash rust inhibitor ZT-706, silicone modified styrene-acrylate copolymer emulsion LR-2052, film-forming aid alcohol ester twelve, scratch resistant aid BYK-410, substrate wetting and leveling agent Tego-270, thickener TT-936 and Haimings 105A (50%) in sequence. After stirring for 30 min, a high solids and low viscosity acrylic modified alkyd resin is obtained.

2. The preparation process of a high-solids, low-viscosity acrylic modified alkyd resin according to claim 1, characterized in that: The drying agent is QD10, and the dispersant is SN-5040.

3. The preparation process of a high-solids, low-viscosity acrylic modified alkyd resin according to claim 1, characterized in that: The defoamer is Tego-810, the titanium dioxide is THR-218, the precipitated barium sulfate is 800 mesh, and the flash rust inhibitor is ZT-706.

4. The preparation process of a high-solids, low-viscosity acrylic modified alkyd resin according to claim 1, characterized in that: The waterborne styrene-acrylate copolymer emulsion is LR-2052, the scratch-resistant additive is BYK-410, the substrate wetting and leveling agent is Tego-270, and the alkali-swelling thickener is TT-936.

5. The preparation process of a high-solids, low-viscosity acrylic modified alkyd resin according to claim 1, characterized in that: The heating temperature in step 1 is 130-160 ℃.

6. The preparation process of a high-solids, low-viscosity acrylic modified alkyd resin according to claim 1, characterized in that: In step 2, the heat preservation time is 40-70 min, the heating temperature is 180-210 ℃, and the temperature is cooled to 130-150 ℃.

7. The preparation process of a high-solids, low-viscosity acrylic modified alkyd resin according to claim 1, characterized in that: The stirring time in step 3 is 30-50 minutes.

8. The preparation process of a high-solids, low-viscosity acrylic modified alkyd resin according to claim 1, characterized in that: In step 4, the stirring rate is 500-650 r / min.

9. The preparation process of a high-solids, low-viscosity acrylic modified alkyd resin according to claim 1, characterized in that: In step 5, the dispersion time is 40-60 min and the grinding time is 40-60 min.

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