All-season high-solid anti-rust primer and preparation method thereof

Abstract

This invention provides a high-solids anti-rust primer suitable for all seasons and its preparation method. The anti-rust primer comprises component A and component B. Component A includes the following raw materials in parts by weight: 30-40% bisphenol F epoxy resin, 1-10% reactive diluent, 1-8% liquid carboxyl-terminated nitrile butadiene rubber (CTBN), 0.1-0.3% triphenylphosphine, 0.1-0.6% dispersant, 0.2-0.6% defoamer, 1-5% modified chopped glass fiber, 40-50% pigments and fillers, 0.7-1.3% thixotropic agent, and 3-5% solvent. Component B includes the following raw materials in parts by weight: 50-70% amine curing agent, 2-5% hyperbranched epoxy resin, and 25-45% modified ketimide curing agent. The anti-rust primer of this invention has the advantages of high solids content and high flexibility, and can be applied to damp surfaces and in ambient temperatures ranging from -10 to 40°C. Furthermore, the prepared anti-rust primer, as a coating, can be used as a rust-preventive primer for multiple parts of the ship, from the bottom to the hull, and has significant benefits in improving ship painting efficiency and reducing fugitive VOC emissions during the painting process.

Description

Technical Field

[0001] This invention relates to the field of coating technology, and in particular to a high-solids anti-rust primer suitable for all seasons and its preparation method. Background Technology

[0002] General-purpose anti-rust primers can be used on various parts of a ship, offering excellent corrosion resistance, compatibility, and all-season versatility. Their application effectively reduces the types of paint used in shipbuilding and simplifies the painting process, making them highly favored by shipyards and traditional manufacturers. Therefore, general-purpose anti-rust primers have become the most widely used paint category in shipbuilding, accounting for as much as 60-70% of the total paint volume in new shipbuilding. Currently, the volume solids content of general-purpose anti-rust primers used in domestic shipbuilding is generally 68-80%. In recent years, with the increasing restrictions on VOC emissions from the International Maritime Organization (IMO) and various laws and regulations, the environmental upgrading of ship coatings is imperative, and the demand for general-purpose anti-rust primers is developing towards higher solids content and solvent-free formulations.

[0003] On the other hand, most general-purpose anti-rust paints are applied under ambient temperatures, and their application temperature range varies greatly across different shipyard environments in the north and south, ranging from -10℃ to 40℃ throughout the year. Typically, the movement of resin molecular chains is slow at low temperatures, resulting in a slower curing reaction. To achieve low-temperature curing, highly active low-temperature curing agents are required. However, because of their high activity, these agents will have a limited pot life when used at room temperature, leading to insufficient application time. Conversely, reducing the activity of the curing agent to meet the room-temperature adaptation period will result in low reactivity at low temperatures, slow drying speed, and inability to meet application requirements.

[0004] To address the aforementioned issues, CN101638550A utilizes a branched reactive diluent and solvent system to create a steric hindrance effect, extending the product's pot life and solving the problem of all-season applicability for general-purpose anti-rust paints. However, this formulation has a high solvent content, making it unsuitable for high-solids systems. CN112029382A combines curing agents with different Lewis acidity and basicity to create a combination with varying curing rates (fast, medium, and slow), extending the pot life and meeting the requirement for all-season applicability. However, the curing agents used in this combination exhibit high activity at 5°C and above, but lower reactivity around -10°C, resulting in a longer curing time. CN104479505A introduces a thiourea-modified aliphatic polyamine curing agent into a general-purpose anti-rust paint, which improves the drying speed but also introduces brittleness. To compensate for the reduced flexibility caused by rapid curing, this formulation adds a large amount of coumarone resin and reactive diluent, which will affect the crosslinking density and cathodic disbondment resistance of the formulation. Summary of the Invention

[0005] In view of this, the present invention aims to propose a high-solids anti-rust primer suitable for all seasons and its preparation method, so as to solve the problem that high-solids general-purpose anti-rust primers are difficult to meet the construction requirements of different temperatures in all seasons.

[0006] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0007] On one hand, the present invention proposes a high-solids anti-rust primer applicable to all seasons, comprising component A and component B. Component A comprises the following raw materials in parts by weight: 30-40% bisphenol F epoxy resin, 1-10% reactive diluent, 1-8% liquid carboxyl-terminated nitrile butadiene rubber (CTBN), 0.1-0.3% triphenylphosphine, 0.1-0.6% dispersant, 0.2-0.6% defoamer, 1-5% modified chopped glass fiber, 40-50% pigments and fillers, 0.7-1.3% thixotropic agent, and 3-5% solvent. Component B comprises the following raw materials in parts by weight: 50-70% amine curing agent, 2-5% hyperbranched epoxy resin, and 25-45% modified ketimide curing agent.

[0008] Optionally, the epoxy equivalent of bisphenol F epoxy resin is 150~250 g / eq.

[0009] Optionally, the active diluent is a glycidyl ether diluent with a long carbon chain structure, selected from one or more of 660A, 602, NC513, and AGE.

[0010] Optionally, the dispersant is selected from one or more of BYK110, YK710S, and BYK180; the defoamer is selected from one or more of YK272S, BYKA530, TEGO 900, BYK-080A, and EFKA-2035.

[0011] Optionally, the pigments and fillers are selected from one or more of talc powder, feldspar powder, precipitated barium sulfate, nano iron-titanium powder, mica powder, and iron oxide red.

[0012] Optionally, the thixotropic agent is selected from one or more of polyamide wax, organobentonite, and fumed silica.

[0013] Optionally, the solvent is selected from one or more of xylene, trimethylbenzene, n-butanol, butyl acetate, propylene glycol methyl ether acetate, and cyclohexanone.

[0014] Optionally, the amine curing agent is selected from at least one of modified phenolic amines and modified alicyclic amines, including one or more of SM2125, NX5110, CYDHD531, Ancamine2753, Ancamine2774, Ancamine1618, Ancamine2773, and Ancamine2883.

[0015] On the other hand, the present invention also proposes a method for preparing the above-mentioned all-season high-solids anti-rust primer, including the preparation of component A and component B, wherein the preparation of component A includes the following steps:

[0016] The formulated amounts of bisphenol F epoxy resin, reactive diluent, CTBN and triphenylphosphine were mixed under a nitrogen atmosphere, heated to 90~110℃, and reacted for 2~4 hours under stirring.

[0017] After cooling to room temperature, add the prescribed amount of dispersant, defoamer and solvent, and disperse at 800~1000 rpm for 10~15 min;

[0018] Next, add the modified chopped glass fiber and pigments in the formula amount, and disperse at a speed of 3000~3500 rpm for 60~70 min;

[0019] Reduce the rotation speed to 1000 rpm and add the thixotropic agent as specified in the formula. Disperse the mixture at a constant temperature of 50-60℃ and a rotation speed of 2200-2500 rpm for 15-20 minutes to obtain the all-season high-solids anti-rust primer component.

[0020] The preparation of component B includes the following steps:

[0021] Heat the formulated amount of amine curing agent to 90~95℃;

[0022] The amount of hyperbranched epoxy resin in the formula is added dropwise to the amine curing agent within 1 hour, and the temperature is raised to 120~125℃, and the reaction is maintained for 2~3 hours;

[0023] After cooling to room temperature, add the formulated amount of modified ketimide curing agent and disperse at 1000~1500 rpm for 15~20 minutes to obtain the B component of the all-season high-solids anti-rust primer.

[0024] Optionally, the preparation method of modified chopped glass fibers includes the following steps:

[0025] S1. Dehydrate xylene;

[0026] S2. Dry the chopped glass fibers at 110~120℃ for 20~24h, using chopped glass fibers with a length of 3.0mm~4.5mm and a diameter of 6~17μm;

[0027] S3. The dehydrated xylene and toluene-2,4-diisocyanate (TDI) were mixed at a volume-to-mass ratio of 100 mL: 6 g and ultrasonically dispersed for 10-15 min to obtain a TDI dispersion.

[0028] S4. Dry CTBN at 110~120℃ for 20~24h, add dehydrated xylene and mix, ultrasonically disperse for 10~15min to obtain CTBN dispersion; mix dehydrated xylene and dried CTBN at a volume and weight ratio of 100mL:10g.

[0029] S5. Dehydrated xylene, dried chopped glass fiber, and dibutyltin dilaurate are mixed in a volume:weight:weight ratio of 300~400mL:20g:0.1g, and stirred and dispersed at room temperature for 20~30min to prepare a suspension.

[0030] The TDI dispersion obtained in step S3 was added dropwise to the suspension at a rate of 60 drops / minute under stirring and nitrogen protection conditions at 30~35℃. After the addition was completed, the temperature was raised to 130~140℃ and the reaction continued for 1~2 hours.

[0031] After the reaction was completed, the mixture was filtered and repeatedly washed with dehydrated xylene to remove unreacted TDI. Finally, it was vacuum dried to prepare surface-activated chopped glass fibers.

[0032] S6. Add hydrogen peroxide, ethanol, and xylene to the surface-activated chopped glass fibers. Under stirring and nitrogen protection conditions at 60-62°C, add the CTBN dispersion obtained in step S4 at a rate of 60 drops / minute. After the addition is complete, raise the temperature to 80-85°C and continue the reaction for 3-4 hours. Then, slowly add concentrated hydrochloric acid and ethanol, and adjust the temperature to 110°C to continue the reaction for 2-3 hours. After the reaction is complete, perform vacuum filtration to remove unreacted CTBN, and finally vacuum dry to prepare modified chopped glass fibers.

[0033] Compared with existing technologies, the all-season high-solids anti-rust primer and its preparation method described in this invention have the following advantages:

[0034] (1) It has the advantages of high solid content (component A contains only 3-5% solvent, and the rest are solids) and high flexibility, and can be applied on damp surfaces and in ambient temperatures of -10 to 40°C.

[0035] (2) This invention employs hyperbranched epoxy resin to modify amine curing agents through addition. The hyperbranched polymer has a spherical or quasi-spherical structure with a low tendency for molecular chain entanglement. When mixed with epoxy resin, this structure can form island-like microphase separation in the matrix. Through the above techniques, combined with low-viscosity small-molecule bisphenol F epoxy resin and long-chain reactive diluent, a high-solids, low-viscosity formulation is achieved.

[0036] (3) The present invention achieves a balance between the pot life and the low temperature curing speed by using an amine curing agent added to hyperbranched epoxy resin in conjunction with a modified ketimine curing agent, thereby achieving the all-season versatility of high solids coatings.

[0037] (4) CTBN coating modification was achieved by grafting small-molecule bisphenol F epoxy resin and long-chain reactive diluent with liquid-terminated carboxyl-terminated butadiene-acrylonitrile rubber (CTBN), and by bridging modified chopped glass fibers with isocyanate. This type of filler can be uniformly dispersed in the CTBN-modified epoxy resin system of this invention, while simultaneously improving the interfacial bonding force between the resin and the chopped glass fibers, further enhancing the toughening effect. This invention improves the flexibility of the coating through the synergistic effect of the above methods, reducing the problems of high crosslinking density and high coating brittleness caused by the use of small-molecule resins in high-solids formulations.

[0038] (5) The present invention also forms a coating component with both hydrophilic and hydrophobic properties by the hydrolysis of the modified ketimine curing agent and the hydrophobic effect of the long carbon chain active diluent. This feature enables the coating to achieve drainage function on damp surfaces, improves the adhesion of the coating on damp surfaces and the versatility of the coating. Detailed Implementation

[0039] The present invention will be further described below with reference to specific embodiments. First, it should be noted that the data in the following experimental examples were obtained by the inventors through numerous experiments. Due to space limitations, only a portion of these data is shown in the specification, and those skilled in the art can understand and implement the present invention based on this data. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the contents of this invention, those skilled in the art can make various modifications or alterations to the invention, and these modifications or alterations also fall within the scope of protection of this application.

[0040] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0041] This invention proposes a high-solids anti-rust primer suitable for all seasons, comprising component A and component B. Component A comprises the following raw materials in parts by weight: 30-40% bisphenol F epoxy resin, 1-10% reactive diluent, 1-8% liquid carboxyl-terminated nitrile butadiene rubber (CTBN), 0.1-0.3% triphenylphosphine, 0.1-0.6% dispersant, 0.2-0.6% defoamer, 1-5% modified chopped glass fiber, 40-50% pigments and fillers, 0.7-1.3% thixotropic agent, and 3-5% solvent.

[0042] Component B comprises the following raw materials in parts by weight: 50-70% amine curing agent, 2-5% hyperbranched epoxy resin, and 25-45% modified ketimide curing agent.

[0043] The high solids content of the present invention refers to the nail component having a solids content of 95-97%.

[0044] The epoxy equivalent of bisphenol F epoxy resin is 150~250 g / eq.

[0045] The reactive diluent is a glycidyl ether diluent with a long carbon chain structure, selected from one or more of 660A, 602, NC513, and AGE.

[0046] The liquid carboxyl-terminated nitrile butadiene rubber (CTBN) has an acrylonitrile content of 26.99%, a carboxyl value of 0.4423 mmol / g, a viscosity of 5000cp at (23±2)℃, and an average molecular weight of 3500.

[0047] The dispersant is selected from one or more of BYK110, YK710S, and BYK180.

[0048] The defoamer is selected from one or more of the following: YKA 272S, BYKA 530, TEGO 900, BYK-080A, and EFKA-2035.

[0049] The pigments and fillers are selected from one or more of the following: talc powder, feldspar powder, precipitated barium sulfate, nano iron-titanium powder, mica powder, and iron oxide red.

[0050] The thixotropic agent is selected from one or more of polyamide wax, organobentonite, and fumed silica.

[0051] The solvent is selected from one or more of xylene, trimethylbenzene, n-butanol, butyl acetate, propylene glycol methyl ether acetate, and cyclohexanone.

[0052] The amine curing agent is selected from at least one of modified phenolic amines and modified alicyclic amines, including one or more of SM2125, NX5110, CYDHD531, Ancamine2753, Ancamine2774, Ancamine1618, Ancamine2773, and Ancamine2883.

[0053] The preparation method of hyperbranched epoxy resin is as described in Example 1 of CN118580743A. Specifically, 5g of bisphenol A and 33.11g of triglycidyl ether are added sequentially to a four-necked flask, followed by 0.25g of tetrabutylammonium bromide. The mixture is stirred at 80°C for 12 hours to obtain the hyperbranched epoxy resin.

[0054] The preparation method of the modified ketimine curing agent is the same as in Example 1, specifically: 1-benzyl-2-thiourea and ethylenediamine are added to a three-necked flask in a molar ratio of 2:1, with carbon tetrachloride as the solvent. The three-necked flask is placed in a jacketed magnetic stirrer, and the stirrer, water separator and condenser are connected. The stirrer is turned on and the reaction is controlled at 80°C for 3 hours. The product is then discharged.

[0055] The structural formula of the modified ketimine curing agent is:

[0056]

[0057] The preparation method of modified chopped glass fibers includes the following steps:

[0058] S1. Dehydrate xylene;

[0059] S2. Dry the chopped glass fibers at 110~120℃ for 20~24h, using chopped glass fibers with a length of 3.0mm~4.5mm and a diameter of 6~17μm;

[0060] S3. The dehydrated xylene and toluene-2,4-diisocyanate (TDI) were mixed at a volume-to-mass ratio of 100 mL: 6 g and ultrasonically dispersed for 10-15 min to obtain a TDI dispersion.

[0061] S4. Dry CTBN at 110~120℃ for 20~24h, add dehydrated xylene and mix, ultrasonically disperse for 10~15min to obtain CTBN dispersion; mix dehydrated xylene and dried CTBN at a volume and weight ratio of 100mL:10g.

[0062] S5. Dehydrated xylene, dried chopped glass fiber, and dibutyltin dilaurate are mixed in a volume:weight:weight ratio of 300~400mL:20g:0.1g, and stirred and dispersed at room temperature for 20~30min to prepare a suspension.

[0063] The TDI dispersion obtained in step S3 was added dropwise to the suspension at a rate of 60 drops / minute under stirring and nitrogen protection conditions at 30~35℃. After the addition was completed, the temperature was raised to 130~140℃ and the reaction continued for 1~2 hours.

[0064] After the reaction was completed, the mixture was filtered and repeatedly washed with dehydrated xylene to remove unreacted TDI. Finally, it was vacuum dried at a temperature of 90-100℃ to prepare surface-activated chopped glass fibers.

[0065] S6. Add hydrogen peroxide, ethanol, and xylene to the surface-activated chopped glass fibers. Under stirring and nitrogen protection conditions at 60-62°C, add the CTBN dispersion obtained in step S4 at a rate of 60 drops / minute. After the addition is complete, raise the temperature to 80-85°C and continue the reaction for 3-4 hours. Then, slowly add concentrated hydrochloric acid and ethanol, and adjust the temperature to 110°C to continue the reaction for 2-3 hours. After the reaction is complete, perform vacuum filtration to remove unreacted CTBN. Finally, vacuum dry the product at a temperature controlled at 90-100°C to prepare modified chopped glass fibers.

[0066] The present invention also proposes a method for preparing the above-mentioned all-season high-solids anti-rust primer, including the preparation of component A and component B, wherein the preparation of component A includes the following steps:

[0067] The formulated amounts of bisphenol F epoxy resin, reactive diluent, CTBN and triphenylphosphine were mixed under a nitrogen atmosphere, heated to 90~110℃, and reacted for 2~4 hours under stirring.

[0068] After cooling to room temperature, add the prescribed amount of dispersant, defoamer and solvent, and disperse at 800~1000 rpm for 10~15 min;

[0069] Next, add the modified chopped glass fiber and pigments in the formula amount, and disperse at a speed of 3000~3500 rpm for 60~70 min;

[0070] Reduce the rotation speed to 1000 rpm and add the thixotropic agent as specified in the formula. Disperse the mixture at a constant temperature of 50-60℃ and a rotation speed of 2200-2500 rpm for 15-20 minutes to obtain the all-season high-solids anti-rust primer component.

[0071] The preparation of component B includes the following steps:

[0072] Heat the formulated amount of amine curing agent to 90~95℃;

[0073] The amount of hyperbranched epoxy resin in the formula is added dropwise to the amine curing agent within 1 hour, and the temperature is raised to 120~125℃, and the reaction is maintained for 2~3 hours;

[0074] After cooling to room temperature, add the formulated amount of modified ketimide curing agent and disperse at 1000~1500 rpm for 15~20 minutes to obtain the B component of the all-season high-solids anti-rust primer.

[0075] When using the anti-rust primer of the present invention, it is ready to use after being mixed evenly according to the equivalent ratio of epoxy groups and amino functional groups in components A and B. It can be applied by spraying or brushing.

[0076] This invention employs addition modification of amine curing agents with hyperbranched epoxy resin. The hyperbranched polymer exhibits a spherical or quasi-spherical structure with low molecular chain entanglement tendency. When mixed with epoxy resin, this structure can form island-like microphase separation within the matrix. By combining this technology with low-viscosity, small-molecule bisphenol F epoxy resin and long-chain reactive diluents, a high-solids, low-viscosity formulation is achieved.

[0077] Furthermore, the addition modification of amine curing agents with hyperbranched epoxy resin reduces the content of small-molecule free amines in the curing agent, thereby improving the low-temperature curing speed of the coating. Simultaneously, this invention introduces a modified ketimine curing agent into component B. When components A and B are mixed, the ketimine structure of the modified ketimine curing agent does not react with the epoxy resin, thus extending the pot life of the coating. After application, when the coating comes into contact with the substrate or moisture in the air, the modified ketimine curing agent undergoes hydrolysis, releasing ethylenediamine and 1-benzyl-2-thiourea. The primary amine structure of ethylenediamine can further react with the epoxy resin, while 1-benzyl-2-thiourea can react with the epoxy resin, releasing a large amount of heat, promoting film curing, and increasing the low-temperature curing speed of the coating. Therefore, this invention achieves a balance between pot life and low-temperature curing speed through the synergistic effect of a hyperbranched epoxy resin-added amine curing agent and a modified ketimine curing agent, thereby achieving the year-round versatility of high-solids coatings.

[0078] This invention achieves CTBN-based coating modification by grafting small-molecule bisphenol F epoxy resin and long-chain reactive diluents with liquid-terminated carboxyl-terminated butadiene-acrylonitrile rubber (CTBN), and by bridging modified chopped glass fibers with isocyanate. This filler structure allows for uniform dispersion in the CTBN-modified epoxy resin system of this invention, while simultaneously improving the interfacial bonding between the resin and the chopped glass fibers, further enhancing the toughening effect. Through the synergistic effect of the above methods, this invention improves the flexibility of the coating and mitigates the problems of high crosslinking density and high coating brittleness caused by the use of small-molecule resins in high-solids formulations.

[0079] This invention also utilizes the hydrolysis of modified ketimine curing agent and the hydrophobic effect of long-chain active diluent to form a coating component with both hydrophilic and hydrophobic properties. This feature enables the coating to achieve drainage function on damp surfaces, improving the adhesion of the coating on damp surfaces and the versatility of the coating.

[0080] This invention provides a year-round, high-solids anti-rust primer with advantages such as high solids content (component A contains only 3-5% solvent, with the remainder being solids) and high flexibility, enabling application on damp surfaces and in ambient temperatures ranging from -10 to 40°C. Furthermore, this anti-rust primer, as a coating, can be used for anti-rust applications on multiple parts of the ship, from the bottom to the hull, offering significant benefits in improving ship painting efficiency and reducing fugitive VOC emissions during the painting process.

[0081] Example 1

[0082] Component A comprises the following raw materials in parts by weight:

[0083] The following components are included: 30 parts of bisphenol F epoxy resin with an epoxy equivalent of 150 g / eq; 10 parts of reactive diluent (660A and 602 in a mass ratio of 1:1); 8 parts of CTBN; 0.1 parts of triphenylphosphine; 0.6 parts of BYK110; 0.6 parts of Eucalyptus 272S; 5 parts of modified chopped glass fiber; 40 parts of pigments and fillers (talc, precipitated barium sulfate, and iron oxide red mixed in a mass ratio of 1:3:1); 0.7 parts of thixotropic agent (polyamide wax and organobentonite mixed in a mass ratio of 1:1); and 5 parts of solvent (trimethylbenzene, butyl acetate, and propylene glycol methyl ether acetate in a mass ratio of 3:1:1).

[0084] Component B comprises the following raw materials in parts by weight:

[0085] 50 parts of amine curing agent (SM2125, NX5110, CYDHD531 in a mass ratio of 1:2:1), 5 parts of hyperbranched epoxy resin, and 45 parts of modified ketimine curing agent.

[0086] Example 2

[0087] Component A comprises the following raw materials in parts by weight:

[0088] The composition includes 40 parts of bisphenol F epoxy resin with an epoxy equivalent of 190 g / eq, 1 part of AGE, 8 parts of CTBN, 0.2 parts of triphenylphosphine, 0.3 parts of Eucalyptus 710S, 0.2 parts of BYKA530, 1 part of modified chopped glass fiber, 44 parts of pigments and fillers (feldspar powder, mica powder, and iron oxide red mixed in a mass ratio of 2:2:1), 1.3 parts of polyamide wax, and 4 parts of solvent (xylene, n-butanol, and cyclohexanone in a mass ratio of 2:1:1).

[0089] Component B comprises the following raw materials in parts by weight: 60 parts Ancamine 2883, 2 parts hyperbranched epoxy resin, and 38 parts modified ketimide curing agent.

[0090] Example 3

[0091] Component A comprises the following raw materials in parts by weight:

[0092] The following components were used: 36 parts of bisphenol F epoxy resin with an epoxy equivalent of 250 g / eq, 6 parts of NC513, 1 part of CTBN, 0.3 parts of triphenylphosphine, 0.1 parts of BYK180, 0.6 parts of TEGO 900, 2 parts of modified chopped glass fiber, 50 parts of pigments and fillers (feldspar powder, nano-iron titanium powder, and iron oxide red mixed in a mass ratio of 1:3:2), 1 part of fumed silica, and 3 parts of xylene.

[0093] Component B comprises the following raw materials in parts by weight:

[0094] 70 parts of amine curing agent (Ancamine 2753 and Ancamine 2773 in a 1:1 mass ratio)

[0095] 5 parts of hyperbranched epoxy resin

[0096] 25 parts of modified ketimine curing agent.

[0097] Comparative Example 1

[0098] Comparative Example 1 is a recoatable general-purpose epoxy anti-rust paint that can be applied in all seasons, prepared according to Example 1 of Patent CN101638550B.

[0099] Comparative Example 2

[0100] Component A comprises the following raw materials in parts by weight:

[0101] The composition includes 40 parts of bisphenol F epoxy resin with an epoxy equivalent of 190 g / eq, 1 part of AGE, 0.2 parts of triphenylphosphine, 0.3 parts of Eucalyptus 710S, 0.2 parts of BYKA530, 1 part of modified chopped glass fiber, 44 parts of pigments and fillers (feldspar powder, mica powder, and iron oxide red mixed in a mass ratio of 2:2:1), 1.3 parts of polyamide wax, and 4 parts of solvent (xylene, n-butanol, and cyclohexanone in a mass ratio of 2:1:1).

[0102] Component B comprises the following raw materials in parts by weight:

[0103] Ancamine 2883 60 parts, hyperbranched epoxy resin 2 parts, modified ketimide curing agent 38 parts.

[0104] Comparative Example 3

[0105] Component A comprises the following raw materials in parts by weight:

[0106] The following components were used: 40 parts of bisphenol F epoxy resin with an epoxy equivalent of 190 g / eq, 1 part of AGE, 8 parts of CTBN, 0.3 parts of Eucalyptus 710S, 0.2 parts of BYKA530, 1 part of modified chopped glass fiber, 44 parts of pigments and fillers (feldspar powder, mica powder, and iron oxide red mixed in a mass ratio of 2:2:1), 1.3 parts of polyamide wax, and 4 parts of solvent (xylene, n-butanol, and cyclohexanone in a mass ratio of 2:1:1).

[0107] Component B comprises the following raw materials in parts by weight: 60 parts Ancamine 2883, 2 parts hyperbranched epoxy resin, and 38 parts modified ketimide curing agent.

[0108] Comparative Example 4

[0109] Component A comprises the following raw materials in parts by weight:

[0110] The following components were used: 40 parts of bisphenol F epoxy resin with an epoxy equivalent of 190 g / eq, 1 part of AGE, 8 parts of CTBN, 0.2 parts of triphenylphosphine, 0.3 parts of Eucalyptus 710S, 0.2 parts of BYKA530, 44 parts of pigments and fillers (feldspar powder, mica powder, and iron oxide red mixed in a mass ratio of 2:2:1), 1.3 parts of polyamide wax, and 4 parts of solvent (xylene, n-butanol, and cyclohexanone in a mass ratio of 2:1:1).

[0111] Component B comprises the following raw materials in parts by weight: 60 parts Ancamine 2883, 2 parts hyperbranched epoxy resin, and 38 parts modified ketimide curing agent.

[0112] Comparative Example 5

[0113] Component A comprises the following raw materials in parts by weight: 40 parts of bisphenol F epoxy resin with an epoxy equivalent of 190 g / eq, 1 part of AGE, 8 parts of CTBN, 0.2 parts of triphenylphosphine, 0.3 parts of Eucalyptus 710S, 0.2 parts of BYKA530, 1 part of chopped glass fiber, 44 parts of pigments and fillers (feldspar powder, mica powder, and iron oxide red mixed in a mass ratio of 2:2:1), 1.3 parts of polyamide wax, and 4 parts of solvent (xylene, n-butanol, and cyclohexanone in a mass ratio of 2:1:1).

[0114] Component B comprises the following raw materials in parts by weight: 60 parts Ancamine 2883, 2 parts hyperbranched epoxy resin, and 38 parts modified ketimide curing agent.

[0115] Comparative Example 6

[0116] Component A comprises the following raw materials in parts by weight: 40 parts of bisphenol F epoxy resin with an epoxy equivalent of 190 g / eq, 1 part of AGE, 8 parts of CTBN, 0.2 parts of triphenylphosphine, 0.3 parts of Eucalyptus 710S, 0.2 parts of BYKA530, 1 part of modified chopped glass fiber, 44 parts of pigments and fillers (feldspar powder, mica powder, and iron oxide red mixed in a mass ratio of 2:2:1), 1.3 parts of polyamide wax, and 4 parts of solvent (xylene, n-butanol, and cyclohexanone in a mass ratio of 2:1:1).

[0117] Component B comprises the following raw materials in parts by weight: 60 parts Ancamine 2883, 2 parts hyperbranched epoxy resin, and 38 parts modified ketimide curing agent.

[0118] Comparative Example 7

[0119] Component A comprises the following raw materials in parts by weight: 40 parts of bisphenol F epoxy resin with an epoxy equivalent of 190 g / eq, 1 part of AGE, 8 parts of CTBN, 0.2 parts of triphenylphosphine, 0.3 parts of Eucalyptus 710S, 0.2 parts of BYKA530, 1 part of modified chopped glass fiber, 44 parts of pigments and fillers (feldspar powder, mica powder, and iron oxide red mixed in a mass ratio of 2:2:1), 1.3 parts of polyamide wax, and 4 parts of solvent (xylene, n-butanol, and cyclohexanone in a mass ratio of 2:1:1).

[0120] Component B comprises the following raw materials in parts by weight: 60 parts Ancamine 2883, 2 parts hyperbranched epoxy resin, and 38 parts modified ketimide curing agent.

[0121] Comparative Example 8

[0122] Component A comprises the following raw materials in parts by weight: 40 parts of bisphenol F epoxy resin with an epoxy equivalent of 190 g / eq, 1 part of AGE, 8 parts of CTBN, 0.2 parts of triphenylphosphine, 0.3 parts of Eucalyptus 710S, 0.2 parts of BYKA530, 1 part of modified chopped glass fiber, 44 parts of pigments and fillers (feldspar powder, mica powder, and iron oxide red mixed in a mass ratio of 2:2:1), 1.3 parts of polyamide wax, and 4 parts of solvent (xylene, n-butanol, and cyclohexanone in a mass ratio of 2:1:1).

[0123] Component B comprises the following raw materials in parts by weight: 60 parts of Ancamine 2883 and 38 parts of modified ketimide curing agent.

[0124] Comparative Example 9

[0125] Component A comprises the following raw materials in parts by weight: 40 parts of bisphenol F epoxy resin with an epoxy equivalent of 190 g / eq, 1 part of AGE, 8 parts of CTBN, 0.2 parts of triphenylphosphine, 0.3 parts of Eucalyptus 710S, 0.2 parts of BYKA530, 1 part of modified chopped glass fiber, 44 parts of pigments and fillers (feldspar powder, mica powder, and iron oxide red mixed in a mass ratio of 2:2:1), 1.3 parts of polyamide wax, and 4 parts of solvent (xylene, n-butanol, and cyclohexanone in a mass ratio of 2:1:1).

[0126] Component B comprises the following raw materials in parts by weight: 98 parts Ancamine 2883 and 2 parts hyperbranched epoxy resin.

[0127] Comparative Example 10

[0128] Component A comprises the following raw materials in parts by weight: 40 parts of bisphenol F epoxy resin with an epoxy equivalent of 190 g / eq, 1 part of AGE, 8 parts of CTBN, 0.2 parts of triphenylphosphine, 0.3 parts of Eucalyptus 710S, 0.2 parts of BYKA530, 1 part of modified chopped glass fiber, 44 parts of pigments and fillers (feldspar powder, mica powder, and iron oxide red mixed in a mass ratio of 2:2:1), 1.3 parts of polyamide wax, and 4 parts of solvent (xylene, n-butanol, and cyclohexanone in a mass ratio of 2:1:1).

[0129] Component B comprises the following raw materials in parts by weight: 60 parts Ancamine 2883, 2 parts hyperbranched epoxy resin, and 38 parts modified ketimide curing agent.

[0130] Comparative Example 11

[0131] Component A comprises the following raw materials in parts by weight: 40 parts of bisphenol F epoxy resin with an epoxy equivalent of 190 g / eq, 1 part of AGE, 8 parts of CTBN, 0.2 parts of triphenylphosphine, 0.3 parts of Eucalyptus 710S, 0.2 parts of BYKA530, 1 part of modified chopped glass fiber, 44 parts of pigments and fillers (feldspar powder, mica powder, and iron oxide red mixed in a mass ratio of 2:2:1), 1.3 parts of polyamide wax, and 4 parts of solvent (xylene, n-butanol, and cyclohexanone in a mass ratio of 2:1:1).

[0132] Component B comprises the following raw materials in parts by weight: 60 parts Ancamine 2883, 2 parts hyperbranched epoxy resin, and 38 parts modified ketimide curing agent.

[0133] The preparation methods of the modified chopped glass fibers in Examples 1-3, Comparative Examples 2-3, and Comparative Examples 8-11 are all as follows:

[0134] S1. Dehydration treatment of xylene: 10g of 3A molecular sieve was soaked in 1000mL of xylene for 72h, and then the 3A molecular sieve was removed to obtain dehydrated xylene.

[0135] S2. Drying treatment of chopped glass fibers: Chopped glass fibers with a length of 4 mm and a diameter of 10 μm were placed in a constant temperature oven at 115℃ for 24 hours for drying treatment;

[0136] S3. Add 100 mL of dehydrated xylene to a dry beaker, add 6 g of TDI and sonicate for 10 min to obtain a TDI dispersion.

[0137] S4. CTBN with an acrylonitrile content of 26.99%, a carboxyl value of 0.4423 mmol / g, a viscosity of 5000cp at (23±2)℃, and an average molecular weight of 3500 was placed in a constant temperature oven at 115℃ for 24 hours to dry. In another dry beaker, 100mL of dehydrated xylene and 10g of dried CTBN were added and ultrasonically dispersed for 10min to obtain a CTBN dispersion.

[0138] S5. Preparation of surface-activated chopped glass fibers: 300 mL of dehydrated xylene was added to a dry, sealed three-necked flask with an external oil-water separator and condenser. 20 g of dried chopped glass fibers were then added, followed by 0.1 g of dibutyltin dilaurate. The mixture was stirred and dispersed at room temperature for 20 min to prepare a suspension. Subsequently, the TDI dispersion was transferred to a constant-pressure dropping funnel and added dropwise to the suspension in the three-necked flask at a rate of 60 drops / min under stirring and nitrogen protection at 35°C. After the addition was complete, the temperature of the three-necked flask was raised to 130°C and the reaction continued for 2 h. After the reaction was completed, the three-necked flask was filtered under a dry environment. After filtration, the three-necked flask was washed three times with 50 mL of water-treated xylene to remove unreacted TDI. Finally, the contents of the three-necked flask were vacuum dried at a temperature of 95°C. After vacuum drying, surface-activated chopped glass fibers were prepared.

[0139] S6. Preparation of modified chopped glass fibers: Take a dry, sealed three-necked flask with an external oil-water separator and condenser, add 20 mL of hydrogen peroxide, 50 mL of ethanol, and 200 mL of xylene, then add the surface-activated chopped glass fibers prepared in step S5; transfer the CTBN dispersion into a constant-pressure dropping funnel, and under stirring and nitrogen protection conditions at 60°C, add the CTBN dispersion dropwise into the three-necked flask at a rate of 60 drops / minute. After the addition is complete, raise the temperature of the three-necked flask to 8°C. The reaction was continued at 0℃ for 3 hours. Then, 2 mL of concentrated sulfuric acid and 50 mL of ethanol were slowly added dropwise to the three-necked flask, and the temperature was adjusted to 110℃ to continue the reaction for 2 hours. After the reaction was completed, the three-necked flask was filtered under a dry environment. After filtration, the three-necked flask was washed three times with a small amount of dehydrated xylene to remove unreacted terminal carboxyl nitrile rubber. Finally, the material in the three-necked flask was vacuum dried at a temperature of 95℃. Modified chopped glass fibers can be prepared after vacuum drying.

[0140] The manufacturing process of the modified chopped glass fiber in Comparative Example 6 is basically the same as that in Example 2, but TDI modification is not added during the manufacturing process. The manufacturing process of the modified chopped glass fiber in Comparative Example 7 is basically the same as that in Example 2, but CTBN modification is not added during the manufacturing process. In Comparative Example 5, dried chopped glass fiber is directly added, that is, the chopped glass fiber in step S2 of Example 2 is directly used.

[0141] The preparation process of component A in Examples 1-3, Comparative Examples 2-9, and Comparative Example 11 of this invention is as follows:

[0142] The prescribed amounts of bisphenol F epoxy resin, reactive diluent, CTBN, and triphenylphosphine were added to a nitrogen-protected three-necked flask, heated to 90°C, and reacted for 2 hours with stirring.

[0143] After cooling the reaction product to room temperature, transfer it to a dispersion tank, add the prescribed amounts of dispersant, defoamer and solvent, and disperse at 800 rpm for 10 min.

[0144] According to the formula, add modified chopped glass fiber (or chopped glass fiber) and pigments and fillers to the dispersion tank, and then disperse at 3000 rpm for 60 min.

[0145] Reduce the rotation speed to 1000 rpm, add the thixotropic agent to the dispersion tank, adjust the temperature of the dispersion tank to 50℃ using a water bath, and then disperse at a rotation speed of 2500 rpm for 15 minutes to obtain the all-season high-solids general-purpose anti-rust primer component.

[0146] The preparation process of component A in Comparative Example 10 is as follows:

[0147] The formulated amounts of bisphenol F epoxy resin, reactive diluent, CTBN, and triphenylphosphine were added to a nitrogen-protected three-necked flask and stirred at room temperature for 2 hours.

[0148] The reaction product was transferred to a dispersion tank, and the prescribed amounts of dispersant, defoamer and solvent were added. The mixture was then dispersed at 800 rpm for 10 min.

[0149] According to the formula, modified chopped glass fibers and pigments and fillers are added to the dispersion tank, and then dispersed at 3000 rpm for 60 minutes.

[0150] Reduce the rotation speed to 1000 rpm, add the thixotropic agent to the dispersion tank, adjust the temperature of the dispersion tank to 50~60℃ using a water bath, and then disperse at a rotation speed of 2500 rpm for 15 minutes to obtain the all-season high-solids general-purpose anti-rust primer component.

[0151] The preparation processes of component B in Examples 1-3 and Comparative Examples 2-10 are as follows:

[0152] Add the prescribed amount of amine curing agent to a four-necked flask equipped with a nitrogen tube, an air condenser, a stirrer, a thermometer, and a heater, and then heat it to 90°C.

[0153] The prescribed amount of hyperbranched epoxy resin was added dropwise to a four-necked flask over 1 hour, and the temperature was raised to 120°C and maintained for 3 hours.

[0154] Cool to room temperature, transfer the product to a dispersion tank, add the formulated amount of modified ketimide curing agent, turn on the disperser, and disperse at 1000 rpm for 15 minutes to obtain the B component of the all-season high-solids general-purpose anti-rust primer.

[0155] The preparation process of component B in Comparative Example 11 is as follows:

[0156] Add the prescribed amount of amine curing agent to a four-necked flask equipped with a nitrogen tube, an air condenser, a stirrer, a thermometer, and a heater, and maintain room temperature.

[0157] The prescribed amount of hyperbranched epoxy resin was added dropwise to a four-necked flask over 1 hour, and the reaction was maintained at room temperature for 3 hours.

[0158] The product is transferred to a dispersion tank, and the formulated amount of modified ketimide curing agent is added. The disperser is then turned on and dispersed at 1000 rpm for 15 minutes to obtain the B component of the all-season high-solids general-purpose anti-rust primer.

[0159] After uniformly mixing components A and B according to the equimolar ratios of epoxy and amino functional groups in the examples and comparative examples, performance tests were conducted. The main technical indicators are shown in Table 1, and the test results are shown in Tables 2 and 3. It should be noted that, to ensure the accuracy of the tests, all examples and comparative examples were sprayed onto the same substrate for testing.

[0160] Table 1

[0161]

[0162] Table 2

[0163]

[0164] As shown in Tables 2 and 3, the products of Examples 1-3 of this invention meet the technical requirements for volume solids content, flexibility, drying time, and adhesion to damp steel substrates. The volume solids content and adhesion to damp steel substrates of Comparative Example 1 are lower than those of this invention. The low viscosity of Comparative Example 1 is mainly due to its low solids content.

[0165] Comparative Example 2 did not use elastic CTBN to modify the epoxy resin, therefore its flexibility deteriorated, and its viscosity decreased because no CTBN modifier was added. In the modification process of Comparative Example 3, no catalyst triphenylphosphine was added, therefore CTBN and epoxy resin did not form chemical crosslinks, resulting in a deterioration in the flexibility of the coating.

[0166] Table 3

[0167]

[0168] Comparative Example 4 did not contain modified chopped glass fibers, resulting in poor formulation flexibility. Comparative Example 5, although containing chopped glass fibers, did not modify them, leading to poor dispersion uniformity of the fibers in the coating and weak interfacial bonding between the fibers and resin. This negatively impacted the coating's flexibility, adhesion, salt spray resistance, and cathodic disbondment resistance. Furthermore, fiber agglomeration during coating dispersion also increased the coating's viscosity. Comparative Example 6, while containing modified chopped glass fibers, did not include the bridging agent TDI, resulting in relatively weak chemical bonding between CTBN and the glass fibers. This also led to poor dispersion uniformity of the chopped glass fibers in the coating, deterioration of the coating's flexibility, adhesion, salt spray resistance, and cathodic disbondment resistance. Additionally, fiber agglomeration during coating dispersion further increased the coating's viscosity. Although the chopped glass fibers in Comparative Example 7 were modified, only TDI was used for modification, without CTBN coating. This resulted in poor dispersion uniformity of the chopped glass fibers in the coating, leading to deterioration in the coating's flexibility, adhesion, salt spray resistance, and cathodic disbondment resistance. Furthermore, fiber agglomeration during dispersion caused an increase in the coating's viscosity. Comparative Example 8 did not use hyperbranched epoxy resin for addition modification of the amine curing agent, resulting in a higher content of small-molecule free amines in the curing agent. These free amines affected the coating's corrosion resistance, slowed curing speed, and shortened its pot life. Additionally, the lack of hyperbranched epoxy resin modification prevented the formation of an island-like structure dominated by hyperbranched epoxy resin in the coating, resulting in a slight decrease in flexibility. Comparative Example 9 did not include a modified ketimine curing agent, severely impacting the coating's low-temperature drying speed, high-temperature pot life, and adhesion to damp surfaces. In the preparation process of component A in Comparative Example 10, the CTBN-modified epoxy resin was not heated, therefore CTBN and epoxy resin did not form chemical bonds for cross-linking, leading to a deterioration in the coating's flexibility. In the preparation process of component B in Comparative Example 11, the hyperbranched epoxy resin underwent addition modification with an amine curing agent without heating, resulting in low reactivity. Component B still contained a significant amount of free amine, which affected the coating's corrosion resistance, drying speed, and pot life.

[0169] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A high-solids anti-rust primer suitable for all seasons, characterized in that, The product comprises Component A and Component B. Component A includes the following raw materials in parts by weight: 30-40% bisphenol F epoxy resin, 1-10% reactive diluent, 1-8% liquid carboxyl-terminated nitrile butadiene rubber (CTBN), 0.1-0.3% triphenylphosphine, 0.1-0.6% dispersant, 0.2-0.6% defoamer, 1-5% modified chopped glass fiber, 40-50% pigments and fillers, 0.7-1.3% thixotropic agent, and 3-5% solvent. Component B includes the following raw materials in parts by weight: 50-70% amine curing agent, 2-5% hyperbranched epoxy resin, and 25-45% modified ketimide curing agent.

2. The all-season high-solids anti-rust primer according to claim 1, characterized in that, The epoxy equivalent of bisphenol F epoxy resin is 150~250 g / eq.

3. The all-season high-solids anti-rust primer according to claim 1, characterized in that, The reactive diluent is a glycidyl ether diluent with a long carbon chain structure, selected from one or more of 660A, 602, NC513, and AGE.

4. The all-season high-solids anti-rust primer according to claim 1, characterized in that, The dispersant is selected from one or more of BYK110, YK710S, and BYK180; the defoamer is selected from one or more of YK272S, BYKA530, TEGO 900, BYK-080A, and EFKA-2035.

5. The all-season high-solids anti-rust primer according to claim 1, characterized in that, The pigments and fillers are selected from one or more of the following: talc powder, feldspar powder, precipitated barium sulfate, nano iron-titanium powder, mica powder, and iron oxide red.

6. The all-season high-solids anti-rust primer according to claim 1, characterized in that, The thixotropic agent is selected from one or more of polyamide wax, organobentonite, and fumed silica.

7. The all-season high-solids anti-rust primer according to claim 1, characterized in that, The solvent is selected from one or more of xylene, trimethylbenzene, n-butanol, butyl acetate, propylene glycol methyl ether acetate, and cyclohexanone.

8. The all-season high-solids anti-rust primer according to claim 1, characterized in that, The amine curing agent is selected from at least one of modified phenolic amines and modified alicyclic amines, including one or more of SM2125, NX5110, CYDHD531, Ancamine2753, Ancamine2774, Ancamine1618, Ancamine2773, and Ancamine2883.

9. The method for preparing the all-season high-solids anti-rust primer according to any one of claims 1 to 8, characterized in that, This includes the preparation of component A and component B. The preparation of component A includes the following steps: The formulated amounts of bisphenol F epoxy resin, reactive diluent, CTBN and triphenylphosphine were mixed under a nitrogen atmosphere, heated to 90~110℃, and reacted for 2~4 hours under stirring. After cooling to room temperature, add the prescribed amount of dispersant, defoamer and solvent, and disperse at 800~1000 rpm for 10~15 min; Next, add the modified chopped glass fiber and pigments in the formula amount, and disperse at a speed of 3000~3500 rpm for 60~70 min; Reduce the rotation speed to 1000 rpm and add the thixotropic agent as specified in the formula. Disperse the mixture at a constant temperature of 50-60℃ and a rotation speed of 2200-2500 rpm for 15-20 minutes to obtain the all-season high-solids anti-rust primer component. The preparation of component B includes the following steps: Heat the formulated amount of amine curing agent to 90~95℃; The amount of hyperbranched epoxy resin in the formula is added dropwise to the amine curing agent within 1 hour, and the temperature is raised to 120~125℃, and the reaction is maintained for 2~3 hours; After cooling to room temperature, add the formulated amount of modified ketimide curing agent and disperse at 1000~1500 rpm for 15~20 minutes to obtain the B component of the all-season high-solids anti-rust primer.

10. The preparation method according to claim 9, characterized in that, The preparation method of modified chopped glass fibers includes the following steps: S1. Dehydrate xylene; S2. Dry the chopped glass fibers at 110~120℃ for 20~24h, using chopped glass fibers with a length of 3.0mm~4.5mm and a diameter of 6~17μm; S3. The dehydrated xylene and toluene-2,4-diisocyanate (TDI) were mixed at a volume-to-mass ratio of 100 mL: 6 g and ultrasonically dispersed for 10-15 min to obtain a TDI dispersion. S4. Dry CTBN at 110~120℃ for 20~24h, add dehydrated xylene and mix, ultrasonically disperse for 10~15min to obtain CTBN dispersion; mix dehydrated xylene and dried CTBN at a volume and weight ratio of 100mL:10g. S5. Dehydrated xylene, dried chopped glass fiber, and dibutyltin dilaurate are mixed in a volume:weight:weight ratio of 300~400mL:20g:0.1g, and stirred and dispersed at room temperature for 20~30min to prepare a suspension. The TDI dispersion obtained in step S3 was added dropwise to the suspension at a rate of 60 drops / minute under stirring and nitrogen protection conditions at 30~35℃. After the addition was completed, the temperature was raised to 130~140℃ and the reaction continued for 1~2 hours. After the reaction was completed, the mixture was filtered and repeatedly washed with dehydrated xylene to remove unreacted TDI. Finally, it was vacuum dried to prepare surface-activated chopped glass fibers. S6. Add hydrogen peroxide, ethanol, and xylene to the surface-activated chopped glass fibers. Under stirring and nitrogen protection conditions at 60-62°C, add the CTBN dispersion obtained in step S4 at a rate of 60 drops / minute. After the addition is complete, raise the temperature to 80-85°C and continue the reaction for 3-4 hours. Then, slowly add concentrated hydrochloric acid and ethanol, and adjust the temperature to 110°C to continue the reaction for 2-3 hours. After the reaction is complete, perform vacuum filtration to remove unreacted CTBN, and finally vacuum dry to prepare modified chopped glass fibers.

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