Liquid full-solid high and low temperature resistant anticorrosive wax and preparation method thereof

Abstract

This invention belongs to the field of anti-corrosion waxes, and specifically relates to a liquid all-solid anti-corrosion wax for chassis resistant to high and low temperatures and its preparation method. It comprises 63 parts of epoxy-terminated hydroxyl-terminated polybutadiene guaranaate, 35 parts of microcrystalline wax, 0.3 parts of an organoalkoxytitanate chelate, 0.7 parts of an organozirconium chelate, and 1 part of an organoiron chelate in propylene glycol solution. This invention solves the problems of poor drying properties, easy oil separation on the surface, low surface strength, and easy absorption of contaminants inherent in all-solid anti-corrosion waxes by utilizing a dual method of oxygen curing and moisture curing, and the elastomeric structure of polybutadiene. Unlike traditional all-solid anti-corrosion waxes, it has a room-temperature fluid state, making it easier to apply and penetrate into crevices.

Description

Technical Field

[0001] This invention belongs to the field of anti-corrosion waxes, and specifically relates to a liquid all-solid anti-corrosion wax for use in the automotive industry, containing high and low temperature resistant chassis anti-corrosion wax. Background Technology

[0002] With the increasing export of passenger and commercial vehicles in recent years, the annual export volume of automobiles has been rising year by year. However, rust problems have also become increasingly prominent, especially in vehicle chassis systems, which are more susceptible to corrosion from seawater during sea transport, leading to numerous quality complaints overseas. Traditional chassis corrosion protection mainly relies on wax spraying, typically using solvent-based protective waxes applied to the vehicle chassis via airless spraying. Solvent-based products generally have issues such as dark color, high VOCs, and low flash point, making them unsuitable for direct use in the final assembly plant. Due to the shortcomings of solvent-based products in terms of color, safety, and VOCs, automakers have gradually developed water-based chassis anti-corrosion wax products. However, water-based wax products still contain a small amount of solvent (100g / L), and for some automakers, VOC issues still exist. Furthermore, water-based products suffer from drawbacks such as difficulty drying in winter, poor water resistance, difficulty in baking after line modification, and high temperature requirements for storage and transportation. Therefore, neither water-based nor solvent-based products can perfectly solve the problem of vehicle chassis corrosion protection.

[0003] In addition, regardless of whether it is a water-based or solvent-based anticorrosive wax, after being sprayed on the vehicle chassis, there are high and low temperature resistance issues during the subsequent transportation and storage process in different environments around the world. The main problems are that at high temperatures, the wax film tends to stick and adhere to dust and foreign organisms, while at low temperatures, the wax film cracks and falls off. Therefore, how to solve the problem of chassis anticorrosive wax being resistant to high temperatures and not sticking, and at the same time resistant to low temperatures and not cracking, is a problem that needs to be solved for future vehicle exports.

[0004] Existing all-solid wax systems are all vegetable oil-based and are dried via oxygen curing (e.g., CN113402980A, a type of automotive chassis anti-rust wax and its preparation method). These systems have high viscosity and require a large amount of mineral oil (≥25%), resulting in slow drying speeds. Using cobalt-based driers to increase the drying speed leads to severe surface oil seepage during the drying process, making it prone to dust adsorption and failing to meet the requirements of GB / T1728-2020 Method A (cotton ball method). Furthermore, the resulting film is relatively soft and has poor stone impact resistance. This system is more suitable for cavity wax systems where strength and drying requirements are not high. Cobalt has safety restrictions and its color is generally dark, making it unsuitable for the chassis corrosion protection requirements of exported vehicles. Large amounts of dust and even biological contamination can lead to complaints from overseas customers. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide a liquid, all-solid, high- and low-temperature resistant chassis anti-corrosion wax. This anti-corrosion wax can achieve surface drying in a short time through dual curing methods of oxygen curing and moisture curing at room temperature. Therefore, this invention contains no solvents and does not require additional mineral oil to dilute the viscosity, achieving a near 100% solids content. Simultaneously, this invention utilizes guarana esterification of epoxy-terminated hydroxyl polybutadiene to form a shared structure of double bonds and hydroxyl groups. The surface layer, through contact with moisture and oxygen in the air, quickly forms a non-sticky, tough film, sealing the microcrystalline wax within the film. A dense, high-temperature resistant resin film is formed on the surface, with a low wax content, preventing the microcrystalline wax from becoming sticky at high temperatures. Furthermore, as the inner layer has less contact with the outer layer's oxygen and moisture, the degree of cross-linking decreases, resulting in a high wax content in the cross-linked layer and an increasingly soft wax film that adheres very well to the substrate. At low temperatures, it is not prone to cracking. Even if the outer layer cracks under external force, the inner wax film can re-form a cross-linked film upon contact with oxygen and moisture, creating a self-healing wax film.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a liquid all-solid anti-corrosion wax containing high and low chassis, characterized in that, according to the proportions, it includes 63 parts of epoxy-terminated hydroxyl polybutadiene guaranaate, 35 parts of microcrystalline wax, 0.3 parts of organic alkoxy titanate chelate, 0.7 parts of organic zirconium chelate, and 1 part of propylene glycol solution of organic iron chelate.

[0007] The preparation method of the above-mentioned liquid all-solid chassis anti-corrosion wax containing high and low temperature resistance includes the following steps:

[0008] 1) Hydroxyl-terminated polybutadiene, dissolved in toluene solution, with the catalyst 2-carboxyethylphenylphosphonic acid (CEPPA) added, at 1200 rpm.

[0009] After / minutes, formic acid and hydrogen peroxide were added at a certain temperature, and the mixture was stirred at low speed for 24 hours to carry out epoxidation, resulting in a liquid mixture of epoxy-terminated hydroxyl polybutadiene and toluene.

[0010] 2) Dissolve guaranaic acid in the above mixture of liquid epoxy-terminated hydroxyl polybutadiene and toluene, add chromium tert-butylfuranose catalyst to the above solution, maintain at a high temperature, stir at low speed, dehydrate, and carry out esterification reaction to obtain guaranaic acid modified epoxy-terminated hydroxyl polybutadiene toluene solution, remove toluene, and obtain room temperature liquid epoxy-terminated hydroxyl polybutadiene guaranaic acid ester.

[0011] In the above-mentioned liquid all-solid anti-corrosion wax for chassis resistant to high and low temperatures, in step 1), the molecular weight of the hydroxyl-terminated polybutadiene is 800-1000.

[0012] In the above-mentioned liquid all-solid anti-corrosion wax for chassis resistant to high and low temperatures, in step 1), the mass ratio of hydroxyl-terminated polybutadiene: 2-carboxyethylphenylphosphonic acid (CEPPA): formic acid: hydrogen peroxide is 500:0.2:10:30.

[0013] In the above-mentioned liquid all-solid anti-corrosion wax for chassis that is resistant to high and low temperatures, step 1) refers to the condition of 55°C.

[0014] In the above-mentioned liquid all-solid chassis anti-corrosion wax containing high and low temperature resistance, the higher temperature in step 2) is 85°C.

[0015] The above-mentioned liquid all-solid chassis anti-corrosion wax is characterized in that the microcrystalline wax has an oil content of 5-8% and a melting point of 78°C.

[0016] The aforementioned liquid all-solid anti-corrosion wax for chassis resistant to high and low temperatures, wherein the organic alkoxy titanate chelate is commercially known as TYZOR IBAY.

[0017] The aforementioned liquid all-solid anti-corrosion wax for chassis with high and low temperature resistance, the organozirconium chelate is commercially known as TYZOR 223, and the propylene glycol solution of the organoiron chelate is a propylene glycol solution of triethanolamine iron complex, the mass fraction of which is 35%.

[0018] The above-mentioned method for preparing a liquid all-solid chassis anticorrosion wax with high and low temperature resistance involves heating 63 parts of epoxy-terminated hydroxyl polybutadiene guaranaate to 90°C, adding 35 parts of microcrystalline wax, dispersing at a high temperature of 1200 rpm, cooling to 50°C, adding 0.3 parts of an organic alkoxy titanate chelate chelate, 0.7 parts of an organic zirconium chelate chelate, and 1 part of a propylene glycol solution of an organic iron chelate, and stirring to obtain a liquid all-solid chassis anticorrosion wax with high and low temperature resistance.

[0019] Compared with traditional technologies, the beneficial effects of inventions are:

[0020] 1. The all-solids chassis anticorrosion wax provided by this invention differs from the drying methods of traditional solvent-based anticorrosion waxes, water-based anticorrosion waxes, and high-solids waxes. The formula does not introduce any solvents or mineral oils, employing oxygen curing and wet curing methods. By using organic titanium, zirconium, and iron drying agents, a solid film is rapidly formed on the surface without oil separation, solving safety and environmental emission issues in vehicle painting. Furthermore, the dual drying method increases the drying speed by 80% compared to traditional all-solids waxes, ensuring speed limits on existing passenger vehicle production lines and preventing pollution of the final assembly line. The polybutadiene structure in this invention has high elasticity, effectively resisting stone impacts and protecting the electrophoretic layer, while traditional vegetable oil-modified high-solids waxes lack high elasticity and are difficult to resist stone impacts.

[0021] 2. The all-solid, high- and low-temperature resistant chassis anti-corrosion wax provided by this invention uses guarana-esterified epoxy-terminated hydroxyl-terminated polybutadiene, which contains double bonds and hydroxyl groups, and is cured using an organozirconium iron chelate and titanate. When the wax film comes into contact with air, oxygen and moisture on the surface come into contact with the wax film. Under the action of dual curing, a gradient cross-linked film is formed in a short time, with the degree of cross-linking gradually decreasing from the outside to the inside. A high-temperature resistant resin cross-linked film is formed on the surface. At 120°C, the surface resin layer does not become sticky, and there is no problem of adsorbing pollutants under high-temperature conditions. Under low-temperature conditions, due to the low degree of cross-linking, small molecular weight, and good toughness of the inner wax film, it is not easy to crack. Even under external force, if the outer wax film breaks, the inner wax film can continue to form an outer high-temperature resistant film under the action of a drying agent, forming a self-healing wax film. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the mechanism of a liquid all-solid chassis anti-corrosion wax resistant to high and low temperatures according to the present invention.

[0023] The figure is marked as: 1-Oligomerized epoxy-terminated hydroxyl polybutadiene guaranaate crosslinking layer. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the embodiments.

[0025] Example 1: A liquid all-solid chassis anti-corrosion wax resistant to high and low temperatures

[0026] (I) The formula composition is as follows

[0027] Formulated by weight

[0028]

[0029] In this embodiment, the microcrystalline wax has an oil content of 5-8% and a melting point of 78°C. The organic alkoxy titanate chelate is commercially known as TYZOR IBAY, the organic zirconium chelate is commercially known as TYZOR 223, and the organic iron chelate is a propylene glycol solution of triethanolamine iron complex (mass fraction of 35%).

[0030] (II) The preparation method is as follows:

[0031] 1. Preparation of epoxy-terminated hydroxyl polybutadiene guaranaate:

[0032] 500g of hydroxyl-terminated polybutadiene (molecular weight 800-1000) was dissolved in 1000mL of toluene solution. 0.2g of 2-carboxyethylphenylphosphonic acid (CEPPA) catalyst was added. After stirring at 1200 rpm for 55℃, 10g of formic acid and 30g of hydrogen peroxide were added, and the mixture was stirred at low speed for 24h to perform epoxidation, yielding a liquid mixture of epoxy hydroxyl-terminated polybutadiene and toluene. 120g of the above solution was taken, and 21g of guaranaic acid was dissolved in the mixture of the above liquid epoxy polybutadiene resin and toluene. 0.7g of chromium tert-butylfuranose catalyst was added to the above solution. The temperature was maintained at 85℃, and the mixture was stirred at low speed for 6h. Dehydration and esterification were then performed to obtain a guaranaic acid-modified epoxy hydroxyl-terminated polybutadiene toluene solution. Toluene was then removed by distillation in a high-speed dispersion process to obtain a room-temperature liquid epoxy hydroxyl-terminated polybutadiene guaranaate.

[0033] 2. Preparation of liquid-based all-solid chassis anti-corrosion wax resistant to high and low temperatures:

[0034] Take 63g of the prepared liquid epoxy-terminated hydroxyl polybutadiene guaranaate, heat to 90°C, add microcrystalline wax, disperse at 1200 rpm, cool to 50°C, add 0.3g of TYZOR IBAY organoalkoxy titanate chelate, 0.7g of organozirconium chelate (trade name: TYZOR 223), and 1g of a propylene glycol solution of triethanolamine iron complex (mass fraction: 35%), stir for 10min to obtain the liquid all-solid anticorrosive wax for chassis with high and low temperature resistance of the present invention.

[0035] (III) Comparative Example and Performance Testing

[0036] 1. Comparative Example 1

[0037] Flaxseed oil long-oil alkyd resin was used to replace the epoxy-terminated hydroxyl polybutadiene guaranaate in Example 1, while other components and proportions remained unchanged, and the preparation method remained unchanged.

[0038] 2. Comparative Example 2

[0039] Microcrystalline wax (melting point 90℃, oil content 3%) was used to replace the microcrystalline wax in Example 1, while other components and proportions remained unchanged, and the preparation method remained unchanged.

[0040] 3. Comparative Example 3

[0041] The propylene glycol solution of TYZOR IBAY organoalkoxy titanate chelate, organozzirconium chelate TYZOR 223, and triethanolamine iron complex (mass fraction of 35%) in Example 1 was replaced with a cobalt manganese naphthenate composite drying agent, while other components and proportions remained unchanged, and the preparation method remained unchanged.

[0042] 4. Comparative Example 4

[0043] Hydroxyl-terminated polybutadiene with a molecular weight of 3000 was used instead of the hydroxyl-terminated polybutadiene with a molecular weight of 800-1000 in Example 1, while other components and proportions remained unchanged, and the preparation method remained unchanged.

[0044] Specific testing technical indicators are shown in Table 1:

[0045] Table 1 Comparison of the performance of the preservative waxes prepared in the examples and comparative examples

[0046]

[0047] As shown in Table 1, the liquid all-solid chassis anticorrosion wax is a pale yellow, room-temperature-flowing liquid (25℃), with a flash point ≥200℃, a surface drying time of 1h, a solid content greater than 99.5%, resistance to stone impact (affected area ≤10.7%), high-temperature adhesion resistance of 100℃, low-temperature cracking resistance of -50℃, and salt spray resistance of 3000h (100 microns).

[0048] Comparative Example 1, using a long-oil alkyd resin system made only by oxidative drying, lacks the speed and cross-linking density of the oxygen curing and hydroxyl curing methods of this invention, failing to meet the drying requirements of GB / T1728 Method A. It also easily attracts dust during the later drying stages. Furthermore, the high viscosity of the long-oil alkyd resin itself hinders its compatibility with microcrystalline waxes, resulting in excessive viscosity that prevents direct spraying. The alkyd resin also fails to encapsulate sufficient microcrystalline wax molecules, leading to poor surface sealing and affecting salt spray test time. In contrast, the double bond and hydroxyl dual curing method of this invention forms a dense network structure that encapsulates a large number of microcrystalline wax microstructures, reducing the attraction between microcrystalline waxes and thus lowering the overall product viscosity and increasing salt spray test time. However, the poor cross-linking strength of the long-oil alkyd resin makes it less effective against stone impact than this invention.

[0049] Comparative Example 2 uses a high-melting-point microcrystalline wax with low oil content. Although its composition is very similar to Example 1, the high-melting-point microcrystalline wax and low oil content directly lead to insufficient adhesion between the inner layer of the wax film and the substrate at low temperatures. Due to the lack of low-molecular-weight liquid oil, the low-polymerization double bonds and hydroxyl groups in the inner layer cannot bond the high-molecular-weight wax crystals at low temperatures, causing the inner wax structure to crack due to internal stress within the crystals. In contrast, Example 1 uses a medium-oil-content, medium-melting-point microcrystalline wax with a relatively moderate wax molecular weight. Furthermore, it is diluted with low-molecular-weight oil, resulting in a lower tendency for wax crystal precipitation and better flexibility. With the help of double bonds and hydroxyl groups, it can better improve the adhesion of the wax at low temperatures and prevent low-temperature cracking.

[0050] Comparative Example 3 used a traditional cobalt-manganese naphthenate-based drying agent, which resulted in an excessively dark color and was subject to EU restrictions, limiting its export potential. In terms of drying, cobalt-manganese-based drying agents did not contribute as much to surface drying as organic chelates such as zirconium-iron and titanates. Furthermore, zirconium / titanium can passivate the substrate, improve adhesion, and increase salt spray resistance time.

[0051] Comparative Example 4 used high molecular weight hydroxyl-terminated polybutadiene to participate in the reaction. Due to the large molecular weight, liquid epoxy hydroxyl-terminated polybutadiene guaranaate could not be formed during the synthesis process, resulting in the formation of a final solid product that could not be used.

[0052] The mechanism of liquid-solid chassis anti-corrosion wax containing high and low temperature resistant materials is as follows: Figure 1 As shown, during the drying process, the degree of cross-linking decreases from the outside to the inside. The outer layer is dense, with less wax content in the cross-linked layer, resulting in better film drying properties. The inner layer has a slightly lower degree of cross-linking, with a higher wax content, resulting in better adhesion and toughness. Furthermore, due to the higher oil content, the wax crystals are separated by low molecular weight oil at low temperatures, avoiding cracking caused by internal stress.

Claims

1. A liquid all-solid chassis anti-corrosion wax resistant to high and low temperatures, characterized in that, The mixture, by weight, comprises 63 parts of epoxy-terminated hydroxyl polybutadiene guaranaate, 35 parts of microcrystalline wax, 0.3 parts of organic alkoxy titanate chelate, 0.7 parts of organic zirconium chelate, and 1 part of a propylene glycol solution of organic iron chelate; the microcrystalline wax has an oil content of 5-8% and a melting point of 78°C. The preparation method of the epoxy-terminated hydroxyl polybutadiene guaranaate includes the following steps: 1) Hydroxyl-terminated polybutadiene was dissolved in toluene solution, and 2-carboxyethylphenylphosphonic acid (CEPPA) was added as a catalyst. After stirring at 1200 rpm, formic acid and hydrogen peroxide were added at a certain temperature, and the mixture was stirred at low speed for 24 hours to carry out epoxidation, resulting in a liquid epoxy hydroxyl-terminated polybutadiene and toluene mixture. 2) Guaranaic acid was dissolved in the above mixture of liquid epoxy-terminated hydroxyl polybutadiene and toluene to obtain a solution. Chromium tert-butylfuranose catalyst was added to the above solution, and the solution was maintained at a high temperature and stirred at a low speed to dehydrate and carry out an esterification reaction to obtain a guaranaic acid-modified epoxy-terminated hydroxyl polybutadiene toluene solution. Toluene was removed to obtain room temperature liquid epoxy-terminated hydroxyl polybutadiene guaranaate.

2. The liquid all-solid chassis anti-corrosion wax according to claim 1, characterized in that, In step 1), the molecular weight of the hydroxyl-terminated polybutadiene is 800-1000.

3. The liquid all-solid chassis anti-corrosion wax according to claim 1, characterized in that, In step 1), the mass ratio of hydroxyl-terminated polybutadiene: 2-carboxyethylphenylphosphine acid (CEPPA): formic acid: hydrogen peroxide is 500:0.2:10:

30.

4. The liquid all-solid chassis anti-corrosion wax according to claim 1, characterized in that, In step 1), the temperature mentioned is 55°C.

5. The liquid all-solid chassis anti-corrosion wax according to claim 1, characterized in that, In step 2), the higher temperature is 85°C.

6. The liquid all-solid chassis anti-corrosion wax according to claim 1, characterized in that, The organic alkoxy titanate chelate is traded under the name TYZOR IBAY.

7. The liquid all-solid chassis anti-corrosion wax according to claim 1, characterized in that, The organoziron chelate is traded as TYZOR 223. The propylene glycol solution of the organoiron chelate is a propylene glycol solution of the triethanolamine iron complex, with a mass fraction of 35% for the triethanolamine iron complex.

8. The preparation method of a liquid all-solid chassis anticorrosion wax according to claim 1, characterized in that, 63 parts of epoxy-terminated hydroxyl polybutadiene guaranaate were heated to 90°C, 35 parts of microcrystalline wax were added, and the mixture was dispersed at a high temperature of 1200 rpm. The mixture was then cooled to 50°C, and 0.3 parts of an organic alkoxy titanate chelate, 0.7 parts of an organic zirconium chelate, and 1 part of an organic iron chelate propylene glycol solution were added. The mixture was stirred to obtain a liquid all-solid chassis anticorrosion wax resistant to high and low temperatures.

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