Waterborne epoxy ester resin composition having initial water resistance and method for preparing the same

Abstract

This invention provides a waterborne epoxy ester resin composition with initial water resistance and its preparation method. A two-step esterification method is designed to prepare conjugated epoxy ester intermediate A and non-conjugated epoxy ester intermediate B. The first, second, and third components are then added dropwise to the mixture of conjugated epoxy ester intermediate A and non-conjugated epoxy ester intermediate B in a segmented manner to graft and modify the two epoxy ester intermediates. Utilizing the characteristic that the conjugated double bonds in conjugated epoxy ester intermediate A are more readily copolymerized with vinyl monomers, the grafting rate of the hydrophilic vinyl monomer D onto the epoxy ester intermediate is increased. Furthermore, the combined use of conjugated epoxy ester intermediate A and non-conjugated epoxy ester intermediate B ensures that the waterborne epoxy ester resin composition possesses both a good grafting rate and relatively high oxidative crosslinking functionality, thereby improving the initial water resistance of the waterborne epoxy ester coating.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of polymers, in particular, relates to a waterborne epoxy ester resin composition with initial water resistance and a preparation method thereof. BACKGROUND

[0002] Single-component waterborne anticorrosive coatings can be applied to C1-C3 atmospheric corrosion levels specified in GB / T30790.1-2014 "Protective Coatings for Steel Structures" Part 2 Environmental Classification due to their excellent workability and environmental characteristics. The most commonly used single-component waterborne anticorrosive coatings mainly include three systems: acrylic emulsion system, waterborne alkyd system and waterborne epoxy ester system. Among them, the waterborne epoxy ester system has certain advantages in hardness and corrosion resistance, and has achieved rapid promotion in the fields of industrial corrosion protection such as steel structure, engineering machinery and automobile parts.

[0003] In the practical application of single-component waterborne epoxy ester coatings, attention will be paid to several key properties of the coating, such as water resistance, corrosion resistance, hardness and other final properties of the coating. With the development of technology and product application, more and higher requirements are put forward for the application adaptability of waterborne epoxy ester coatings under the premise of ensuring the final properties. For example, in the application site of waterborne epoxy ester coatings, in addition to investigating the final water resistance of the waterborne epoxy ester coating, the initial water resistance of the coating is usually investigated. The initial water resistance is to evaluate the water resistance under the condition that the paint film is not completely dried. The key factor affecting the initial water resistance of the waterborne epoxy ester coating is the structure of the waterborne epoxy ester resin, and the key factors affecting it are the content and distribution of hydrophilic groups and the initial crosslinking density of the coating.

[0004] Currently, the excessive amount of hydrophilic groups in single-component waterborne epoxy ester coatings can significantly reduce the initial water resistance of the corresponding coating. However, if only the amount of hydrophilic groups is reduced to solve the problem of poor initial water resistance of the coating in the preparation of waterborne resins, the water solubility and storage stability of the resin will be affected. In addition, in the preparation process of waterborne epoxy ester, the grafting of vinyl monomers into the epoxy ester intermediate process can cause a decrease in the unsaturation of the epoxy ester due to copolymerization reaction, resulting in a decrease in oxidative crosslinking active sites, which can easily lead to a low crosslinking density of the waterborne epoxy ester coating in the early stage of film formation, and also significantly reduce the initial water resistance of the corresponding coating. SUMMARY

[0005] The purpose of the embodiments of the present application is to provide a waterborne epoxy ester resin composition with initial water resistance, to solve the technical problem that the excessive amount of hydrophilic groups and / or the decrease in crosslinking active sites in the existing waterborne epoxy ester resin composition can easily lead to a decrease in the initial water resistance of the coating of the waterborne epoxy ester resin composition.

[0006] To achieve the above object, the technical scheme adopted by the present application is: a waterborne epoxy ester resin composition with initial water resistance is provided, the raw material composition of the waterborne epoxy ester resin composition with initial water resistance comprises, in percentage of total raw material mass of 100%, 42.86-67.63% of a mixed monomer component, 10-15% of a conjugated epoxy ester intermediate A, 20-35% of a non-conjugated epoxy ester intermediate B and 2.5-5.5% of a neutralizer C, the mixed monomer component comprises a first component, a second component and a third component, the first component comprises the following components in the following percentages:

[0007] 2.5-5% of a hydrophilic vinyl monomer D;

[0008] 0.05-0.13% of an initiator E;

[0009] The second component comprises the following components in the following percentages:

[0010] 35-45.5% of a non-hydrophilic vinyl monomer F;

[0011] 0.25-1.5% of an initiator G;

[0012] The third component comprises the following components in the following percentages:

[0013] 0.06-0.5% of an initiator H;

[0014] 5-15% of a solvent I.

[0015] Optionally, the raw material composition of the conjugated epoxy ester intermediate A comprises a fatty acid J, an epoxy resin K, a polymerization inhibitor L, a catalyst M and a solvent N, the total mass of the fatty acid J and the epoxy resin K accounts for 67-73% of the total mass of the conjugated epoxy ester intermediate A, the solvent N accounts for 28-32% of the total mass of the conjugated epoxy ester intermediate A, the polymerization inhibitor L accounts for 0.05-0.5% of the total mass of the conjugated epoxy ester intermediate A, and the catalyst M accounts for 0.1-2% of the total mass of the conjugated epoxy ester intermediate A.

[0016] Optionally, the fatty acid J is at least one of tung oil acid and dehydrated castor oil acid, the epoxy resin K is a bisphenol A type epoxy resin with an epoxy value of 0.18-0.22 mol / 100g, the polymerization inhibitor L is at least one of 2,6-di-tert-butyl-p-cresol and hydroquinone, the catalyst M is triphenylphosphine, and the solvent N is at least one of ethylene glycol butyl ether, diethylene glycol butyl ether, ethylene glycol tert-butyl ether, propylene glycol methyl ether, propylene glycol butyl ether and dipropylene glycol butyl ether.

[0017] Optionally, the molar ratio of the fatty acid J to the epoxy resin K is (1.9-2.1):1.

[0018] Optionally, the raw material composition of the non-conjugated epoxy ester intermediate B comprises fatty acid O, epoxy resin P, catalyst Q, dehydrated solvent R and dilution solvent S, wherein the mass percentage of the catalyst Q is 0.1-3% based on the total mass of 100% of the fatty acid O and the epoxy resin P, the mass percentage of the dehydrated solvent R is 2-10%, and the mass percentage of the dilution solvent S is 30-55%.

[0019] Optionally, the fatty acid O is at least one of oleic acid, linoleic acid, linolenic acid and soybean oil acid, the epoxy resin P is a bisphenol A type epoxy resin with an epoxy value of 0.04-0.22 mol / 100g, the catalyst Q is at least one of triphenylphosphine, dibutyltin dilaurate and monobutyl tin oxide, the dehydrated solvent R is at least one of mesitylene, mesitylene, C9 aromatic hydrocarbon, methyl isobutyl ketone and solvent oil D40, and the dilution solvent S is at least one of ethylene glycol butyl ether, diethylene glycol butyl ether, ethylene glycol tert-butyl ether, propylene glycol methyl ether, propylene glycol butyl ether and dipropylene glycol butyl ether.

[0020] Optionally, the mass ratio of the fatty acid O to the epoxy resin P is (60-122):100.

[0021] Optionally, the preparation process of the conjugated epoxy ester intermediate A comprises the following steps: adding fatty acid J, epoxy resin K, polymerization inhibitor L and catalyst M into a reactor with a stirrer and a thermometer, stirring and heating to 135-145℃ under nitrogen protection to perform ring-opening esterification, reducing the reaction temperature to 90-95℃ after 5 hours of heat preservation, and adding solvent N to obtain the conjugated epoxy ester intermediate A.

[0022] Optionally, the preparation process of the non-conjugated epoxy ester intermediate B comprises the following steps: adding fatty acid O, epoxy resin P, catalyst Q and dehydrated solvent R into a reaction container with a water trap, slowly increasing the temperature to 100-130℃, heat preserving for 1 hour; stirring and gradually increasing the temperature to 200-230℃ at a temperature increasing speed of 20℃ / hour until the epoxy resin P is completely melted, heat preserving for 5 hours, reducing the temperature to 160-180℃, removing the dehydrated solvent R by vacuum pumping, then reducing the temperature to 90-100℃, and adding dilution solvent S while stirring to obtain the non-conjugated epoxy ester intermediate B.

[0023] Another object of the embodiment of the present application is to provide a preparation method of a water-based epoxy ester resin composition with initial water resistance.

[0024] To achieve the above object, the technical scheme adopted by the present application is as follows: a preparation method of a waterborne epoxy ester resin composition with initial water resistance is provided, which can prepare the waterborne epoxy ester resin composition with initial water resistance provided in any of the above schemes, and the preparation method of the waterborne epoxy ester resin composition with initial water resistance comprises the following steps:

[0025] Step S01: the components contained in the waterborne epoxy ester resin composition with initial water resistance in any of the above schemes are weighed respectively;

[0026] Step S02: the conjugated epoxy ester intermediate A and the non-conjugated epoxy ester intermediate B are mixed, and the epoxy ester intermediate mixed component is obtained after uniform stirring;

[0027] Step S03: the epoxy ester intermediate mixed component is heated to 110-140℃, and the mixed monomer component is added dropwise into the epoxy ester intermediate mixed component; the mixed monomer component comprises a first component, a second component and a third component; during the process of adding the mixed monomer component into the epoxy ester intermediate mixed component, the first component is added dropwise within 0.5-1.5 hours first, then the second component is added dropwise within 3-4 hours, then the temperature of the epoxy ester intermediate mixed component is adjusted to 130-150℃, and the third component is added dropwise within 1-2 hours;

[0028] Step S04: the epoxy ester intermediate mixed component to which the mixed monomer component is added is kept at a temperature of 130-150℃ for 1-2 hours, then cooled to 90-100℃, and the neutralizing agent C is added, so that the waterborne epoxy ester resin composition with initial water resistance is prepared.

[0029] Compared with the prior art, the above one or more technical schemes in the embodiments of the present application have at least one of the following beneficial effects:

[0030] The waterborne epoxy ester resin composition with initial water resistance in the embodiment of the present application or the waterborne epoxy ester resin composition with initial water resistance prepared by the preparation method in the embodiment of the present application, simultaneously introduces the conjugated epoxy ester intermediate A and the non-conjugated epoxy ester intermediate B, the conjugated double bond in the conjugated epoxy ester intermediate A can significantly improve the grafting rate of the hydrophilic vinyl monomer D and the conjugated epoxy ester intermediate A, effectively reduce the self-polymerization of the hydrophilic vinyl monomer D, so as to realize the reduction of the hydrophilic group in the waterborne epoxy ester resin composition, overcome the defect that the relative content of the hydrophilic vinyl monomer self-polymer in the waterborne epoxy ester resin composition is too large to reduce the initial water resistance of the waterborne epoxy ester resin composition coating. And, the non-conjugated epoxy ester intermediate B is obtained by ring-opening esterification and high-temperature polycondensation reaction, since the vinyl monomer preferentially grafts with the conjugated epoxy ester intermediate A in the graft copolymerization process, so as to ensure that the non-conjugated epoxy ester intermediate B retains most of the active methylene reaction sites connected with the double bond in the second step graft polymerization process. The reaction site can provide the crosslinking site for oxidation crosslinking in the film forming process of the waterborne epoxy ester composition, overcome the defect that the unsaturation of the epoxy ester is reduced due to the copolymerization reaction, and the oxidation crosslinking active site is reduced, ensure that the waterborne epoxy ester coating has a relatively high crosslinking density in the early film forming stage, so as to improve the crosslinking of the waterborne epoxy ester coating during the surface drying period, and further improve the initial water resistance of the waterborne epoxy ester coating. Therefore, by using the conjugated epoxy ester intermediate A and the non-conjugated epoxy ester intermediate B, the waterborne epoxy ester resin composition can have good grafting rate and relatively high oxidation crosslinking functionality, and the initial water resistance of the waterborne epoxy ester coating is effectively improved.

[0031] The preparation method of the waterborne epoxy ester resin composition with initial water resistance in the embodiment of the present application adopts a process flow of segmented dropping in the graft copolymerization process of the vinyl monomer and the epoxy ester intermediate, and the first component, the second component and the third component are dropped as three components respectively. In the initial stage of the epoxy ester intermediate with more grafting sites, the first component containing the hydrophilic vinyl monomer D is first dropped into the epoxy ester intermediate, the grafting rate of the hydrophilic vinyl monomer D is improved, the self-polymerization of the hydrophilic vinyl monomer D is effectively reduced, so as to realize the reduction of the hydrophilic groups in the waterborne epoxy ester resin composition, overcome the defect that the amount of the hydrophilic groups in the waterborne epoxy ester resin composition is too large to reduce the initial water resistance of the waterborne epoxy ester resin coating. At the same time, since most of the hydrophilic vinyl monomer D is grafted in the epoxy ester segment, in the film forming process of the waterborne epoxy ester resin, the hydrophilic groups are covered up along with the oxidation crosslinking of the fatty acid segment in the epoxy ester component, so that the water resistance and the initial water resistance of the waterborne epoxy ester resin coating are significantly improved. Then, the second component containing the non-hydrophilic vinyl monomer F is dropped into the epoxy ester intermediate, and even if the grafting sites of the epoxy ester intermediate gradually decrease during the dropping process of the second component containing the non-hydrophilic vinyl monomer F, since the self-polymerization part is a hydrophobic segment, the situation that the hydrophilic segment has an adverse effect on the initial water resistance of the waterborne epoxy ester resin coating does not occur, so as to further improve the water resistance and the corrosion resistance of the waterborne epoxy ester resin. DETAILED DESCRIPTION

[0032] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application. It should be noted that the terms "first", "second" and "third" are only used for description purposes and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0033] The embodiment of the present application provides a waterborne epoxy ester resin composition with initial water resistance, the raw material composition of the waterborne epoxy ester resin composition with initial water resistance includes, according to the percentage of the total mass of the raw material being 100%, 42.86-67.63% of a mixed monomer component, 10-15% of a conjugated epoxy ester intermediate A, 20-35% of a non-conjugated epoxy ester intermediate B and 2.5-5.5% of a neutralizing agent C, the mixed monomer component includes a first component, a second component and a third component, the first component includes the following components in the following percentages:

[0034] 2.5-5% of a hydrophilic vinyl monomer D;

[0035] 0.05-0.13% of an initiator E;

[0036] The second component comprises the following components in the following percentages:

[0037] Non-hydrophilic vinyl monomer F 35-45.5%;

[0038] Initiator G 0.25-1.5%;

[0039] The third component comprises the following components in the following percentages:

[0040] Initiator H 0.06-0.5%;

[0041] Solvent I 5-15%.

[0042] The waterborne epoxy ester resin composition with initial water resistance in the embodiment of the present application, compared with the prior art, simultaneously introduces the conjugated epoxy ester intermediate A and the non-conjugated epoxy ester intermediate B, the conjugated double bond in the conjugated epoxy ester intermediate A can significantly improve the grafting rate of the hydrophilic vinyl monomer D and the conjugated epoxy ester intermediate A, effectively reduces the self-polymerization of the hydrophilic vinyl monomer D, thereby realizing the reduction of the hydrophilic group in the waterborne epoxy ester resin composition, overcoming the defect that the amount of the hydrophilic group in the waterborne epoxy ester resin composition is too large to reduce the initial water resistance of the waterborne epoxy ester resin composition coating. Moreover, the non-conjugated epoxy ester intermediate B is obtained by ring-opening esterification and high-temperature polycondensation reaction, since the vinyl monomer preferentially grafts with the conjugated epoxy ester intermediate A in the graft copolymerization process, thereby ensuring that the non-conjugated epoxy ester intermediate B retains most of the active methylene reaction sites connected with the double bond in the second step graft polymerization process. The reaction sites can provide crosslinking sites for oxidation crosslinking in the film forming process of the waterborne epoxy ester composition, overcoming the defect that the decrease in the unsaturation of the epoxy ester caused by the copolymerization reaction leads to the reduction of the active sites for oxidation crosslinking, ensuring that the waterborne epoxy ester coating has a relatively high crosslinking density in the early stage of film formation, and reducing the loss of active sites in the graft copolymerization process by increasing the active sites of the unsaturated fatty acid in the polymer chain, thereby improving the crosslinking of the waterborne epoxy ester coating during the surface drying period, and further improving the initial water resistance of the waterborne epoxy ester coating. Therefore, by using the conjugated epoxy ester intermediate A and the non-conjugated epoxy ester intermediate B, the waterborne epoxy ester resin composition can have good grafting rate and relatively high oxidation crosslinking functionality, effectively improving the initial water resistance of the waterborne epoxy ester coating.

[0043] It should be noted that in some embodiments, the raw material composition of the conjugated epoxy ester intermediate A includes fatty acid J, epoxy resin K, polymerization inhibitor L, catalyst M and solvent N, the total mass of fatty acid J and epoxy resin K accounts for 67-73% of the total mass of the conjugated epoxy ester intermediate A, the solvent N accounts for 28-32% of the total mass of the conjugated epoxy ester intermediate A, the polymerization inhibitor L accounts for 0.05-0.5% of the total mass of the conjugated epoxy ester intermediate A, and the catalyst M accounts for 0.1-2% of the total mass of the conjugated epoxy ester intermediate A.

[0044] It should be noted that in some embodiments, the fatty acid J is at least one of tung oil acid and dehydrated castor oil acid, the epoxy resin K is a bisphenol A type epoxy resin with an epoxy value of 0.18-0.22 mol / 100g, the polymerization inhibitor L is at least one of 2,6-di-tert-butyl-p-cresol and hydroquinone, the catalyst M is triphenylphosphine, and the solvent N is at least one of ethylene glycol butyl ether, diethylene glycol butyl ether, ethylene glycol tert-butyl ether, propylene glycol methyl ether, propylene glycol butyl ether, and dipropylene glycol butyl ether.

[0045] It should be noted that in some embodiments, the molar ratio of fatty acid J to epoxy resin K is (1.9-2.1):1.

[0046] It should be noted that in some embodiments, the preparation process of the conjugated epoxy ester intermediate A is as follows: fatty acid J, epoxy resin K, polymerization inhibitor L and catalyst M are added to a reactor with a stirrer and a thermometer, and under nitrogen protection, the ring-opening esterification reaction is carried out by stirring and heating to 135-145℃, after 5 hours of incubation, the reaction temperature is reduced to 90-95℃, and solvent N is added to obtain the conjugated epoxy ester intermediate A.

[0047] It should be noted that in some embodiments, the raw material composition of the non-conjugated epoxy ester intermediate B includes fatty acid O, epoxy resin P, catalyst Q, dehydration solvent R and dilution solvent S, and in terms of the total mass of fatty acid O and epoxy resin P as 100%, the mass percentage of catalyst Q is 0.1-3%, the mass percentage of dehydration solvent R is 2-10%, and the mass percentage of dilution solvent S is 30-55%.

[0048] It should be noted that in some embodiments, the fatty acid O is at least one of oleic acid, linoleic acid, linolenic acid, soybean oil acid, the epoxy resin P is a bisphenol A type epoxy resin with an epoxy value of 0.04-0.22 mol / 100g, the catalyst Q is at least one of triphenylphosphine, dibutyltin dilaurate, monobutyl tin oxide, the dehydrating solvent R is at least one of mesitylene, mesitylene, C9 aromatic hydrocarbon, methyl isobutyl ketone, solvent oil D40, and the dilution solvent S is at least one of ethylene glycol butyl ether, diethylene glycol butyl ether, ethylene glycol tert-butyl ether, propylene glycol methyl ether, propylene glycol butyl ether, dipropylene glycol butyl ether.

[0049] It should be noted that in some embodiments, the mass ratio of the fatty acid O to the epoxy resin P is (60-122): 100.

[0050] It should be noted that in some embodiments, the preparation process of the non-conjugated epoxy ester intermediate B is as follows: the fatty acid O, the epoxy resin P, the catalyst Q, and the dehydrating solvent R are added to a reaction container with a water trap, the temperature is slowly raised to 100-130°C, and the temperature is kept for 1 hour; until the epoxy resin P is completely melted, the temperature is gradually raised to 200-230°C at a temperature raising speed of 20°C / hour, and the temperature is kept for 5 hours; then the temperature is lowered to 160-180°C, the dehydrating solvent R is removed by vacuum pumping, and then the temperature is lowered to 90-100°C; while stirring, the dilution solvent S is added to obtain the non-conjugated epoxy ester intermediate B.

[0051] It should be noted that in some embodiments, the hydrophilic vinyl monomer D is at least one of acrylic acid and methacrylic acid, and the non-hydrophilic vinyl monomer F is at least one of methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isobornyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, hexyl methacrylate, isobornyl methacrylate, benzyl acrylate, and styrene.

[0052] It should be noted that in some embodiments, the initiator E is at least one of tert-amyl peroxy-2-ethylhexanoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxy acetate, 1,1-di-tert-butyl peroxy-3,3,5-trimethylcyclohexane, 1,1-di-tert-butyl peroxy cyclohexane, 2,2-di(tert-butyl peroxy)butane, and tert-butyl peroxy benzoate.

[0053] It is to be noted that in some embodiments, initiator G is at least one of t-amyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxy acetate, 1,1-di-t-butyl peroxy-3,3,5-trimethyl cyclohexane, 1,1-di-t-butyl peroxy cyclohexane, 2,2-di(t-butyl peroxy) butane, t-butyl peroxy benzoate.

[0054] It is to be noted that in some embodiments, initiator H is at least one of di-t-butyl peroxide, di-t-amyl peroxide.

[0055] It is to be noted that in some embodiments, solvent I is at least one of ethylene glycol butyl ether, diethylene glycol butyl ether, ethylene glycol t-butyl ether, propylene glycol methyl ether, propylene glycol butyl ether, dipropylene glycol butyl ether.

[0056] The present application also provides a preparation method of the waterborne epoxy ester resin composition with initial water resistance according to any one of the above embodiments.

[0057] It is to be noted that in some embodiments, the preparation method of the waterborne epoxy ester resin composition with initial water resistance provided by the present application comprises the following steps:

[0058] Step S01: according to the components contained in the waterborne epoxy ester resin composition with initial water resistance according to any one of the above embodiments, each raw material is weighed separately;

[0059] Step S02: the conjugated epoxy ester intermediate A is mixed with the non-conjugated epoxy ester intermediate B, and after stirring uniformly, an epoxy ester intermediate mixture component is obtained.

[0060] Step S03: the epoxy ester intermediate mixture component is heated to 110-140℃, and the mixed monomer component is added dropwise into the epoxy ester intermediate mixture component; the mixed monomer component comprises the first component, the second component and the third component; during the process of adding the mixed monomer component into the epoxy ester intermediate mixture component, the first component is added dropwise within 0.5-1.5 hours first, then the second component is added dropwise within 3-4 hours, then the temperature of the epoxy ester intermediate mixture component is adjusted to 130-150℃, and the third component is added dropwise within 1-2 hours; through the method of adding dropwise in stages, the hydrophilic vinyl monomer D is added dropwise first, so as to improve the grafting rate of the hydrophilic chain segment with the epoxy ester intermediate, and reduce the adverse effect of the ungrafted hydrophilic chain segment on the performance of the resin, thereby further improving the initial water resistance and corrosion resistance of the waterborne epoxy ester resin coating.

[0061] Step S04: The epoxy ester intermediate mixture component to which the mixed monomer component is added dropwise is kept at a temperature of 130-150°C for 1-2 hours, and then cooled to 90-100°C, and a neutralizing agent C is added, to prepare a waterborne epoxy ester resin composition having initial water resistance.

[0062] It should be noted that in step S02, the preparation process of the conjugated epoxy ester intermediate A is as follows: fatty acid J, epoxy resin K, polymerization inhibitor L and catalyst M are added into a reactor with a stirrer and a thermometer, and ring-opening esterification reaction is carried out under nitrogen protection, stirring and heating to 135-145℃, after 5 hours of incubation, the reaction temperature is reduced to 90-95℃, and solvent N is added to obtain the conjugated epoxy ester intermediate A. The preparation process of the non-conjugated epoxy ester intermediate B is as follows: fatty acid O, epoxy resin P, catalyst Q and dehydration solvent R are added into a reaction container with a water separator, and the temperature is slowly increased to 100-130℃, and incubated for 1 hour; until the epoxy resin P is completely melted, stirring and gradually increasing the temperature to 200-230℃ at a rate of 20℃ / hour, incubated for 5 hours, then cooled to 160-180℃, vacuumed to remove the dehydration solvent R, then cooled to 90-100℃, and diluted solvent S is added while stirring to obtain the non-conjugated epoxy ester intermediate B. In the above step S02, two types of epoxy ester intermediates with different double bond types (conjugated epoxy ester intermediate A and non-conjugated epoxy ester intermediate B) are first prepared. Among them, the conjugated epoxy ester intermediate A with higher content of conjugated double bond is prepared by ring-opening esterification reaction, and the temperature is generally lower than 150℃, which avoids the high-temperature addition side reaction of conjugated double bond while introducing conjugated double bond. In addition, the non-conjugated epoxy ester intermediate B with higher content of non-conjugated double bond is prepared by high-temperature esterification reaction (the highest temperature is generally greater than 200℃). In the graft copolymerization process, the conjugated double bond is more easily copolymerized with the vinyl monomer (hydrophilic vinyl monomer D and non-hydrophilic vinyl monomer F), which improves the grafting rate of the vinyl monomer (hydrophilic vinyl monomer D and non-hydrophilic vinyl monomer F) and the epoxy ester intermediate (conjugated epoxy ester intermediate A and non-conjugated epoxy ester intermediate B). Because the vinyl monomer preferentially grafts with the conjugated epoxy ester intermediate A in the graft copolymerization, more active methylene reaction sites are reserved for the non-conjugated epoxy ester intermediate B in the second graft polymerization process, which provides crosslinking sites for oxidation crosslinking in the waterborne epoxy ester film forming process, improves the crosslinking during the surface drying of the waterborne epoxy ester coating, and thus improves the initial water resistance of the waterborne epoxy ester coating. By using the two types of epoxy ester intermediates (conjugated epoxy ester intermediate A and non-conjugated epoxy ester intermediate B), the waterborne epoxy ester resin composition has better grafting rate and higher oxidation crosslinking functionality during film forming. In addition, the gel content of the waterborne epoxy ester resin composition under the action of the catalyst is improved to more than 54% by the technical scheme of the present application, which significantly reduces the relative content of the vinyl monomer homopolymer, thereby improving the initial water resistance of the coating.

[0063] It should be noted that in step S02, during the grafting of the vinyl monomer onto the epoxy ester intermediate, the hydrophilic vinyl monomer D and the non-hydrophilic vinyl monomer F are separately added by using a segmented dropwise addition method. The advantages of this technical solution include two aspects: first, by using the dropwise addition process designed in the technical solution of the present application, there are more grafting sites in the epoxy ester intermediate at the initial stage of dropwise addition, and the hydrophilic vinyl monomer D is added at this stage to improve the grafting rate of the hydrophilic monomer. Since the hydrophilic vinyl monomer D is mostly grafted onto the epoxy ester segment, during the film formation of the waterborne epoxy ester, along with the oxidative crosslinking of the fatty acid segment in the epoxy ester component, the hydrophilic group is covered up, and the water resistance and initial water resistance of the coating are significantly improved. Second, during the second step of dropwise addition of the non-hydrophilic vinyl monomer F, the grafting sites in the epoxy ester intermediate gradually decrease, and part of the non-hydrophilic vinyl monomer F inevitably undergoes self-polymerization. However, due to the design of the three-stage dropwise addition method, the vinyl monomers in the second stage of dropwise addition are all non-hydrophilic vinyl monomers F, so that the self-polymerization part is a hydrophobic segment. This part of the ungrafted component has little effect on the water resistance of the waterborne epoxy ester resin, thereby further improving the water resistance and corrosion resistance of the resin.

[0064] The method for preparing a waterborne epoxy ester resin composition with initial water resistance provided by the embodiments of the present application designs a two-step esterification method to prepare conjugated epoxy ester intermediate A and non-conjugated epoxy ester intermediate B with different types of double bonds, respectively, and by using a segmented dropwise addition method, the first component, the second component, and the third component are sequentially added to the mixture of the conjugated epoxy ester intermediate A and the non-conjugated epoxy ester intermediate B to modify the two epoxy ester intermediates. First, by using the characteristic that the conjugated double bond in the conjugated epoxy ester intermediate A is more easily copolymerized with the vinyl monomer, the grafting rate of the vinyl monomer, especially the hydrophilic vinyl monomer D, to the epoxy ester intermediate is improved, and the initial water resistance of the waterborne epoxy ester resin coating is improved. Moreover, the non-conjugated epoxy ester intermediate B is obtained by ring-opening esterification and high-temperature polycondensation. Since the vinyl monomer preferentially grafts with the conjugated epoxy ester intermediate A during the grafting copolymerization process, the non-conjugated epoxy ester intermediate B retains most of the active methylene reaction sites connected to the double bond during the second step of grafting polymerization, which can provide crosslinking sites for oxidative crosslinking during the film formation of the waterborne epoxy ester composition. This overcomes the defect that the oxidative crosslinking active site is reduced due to the decrease in the unsaturation of the epoxy ester caused by copolymerization, ensures that the waterborne epoxy ester coating has a relatively high crosslinking density in the early stage of film formation, thereby improving the crosslinking of the waterborne epoxy ester coating during the surface drying period, and further improving the initial water resistance of the waterborne epoxy ester coating. Therefore, by using the conjugated epoxy ester intermediate A and the non-conjugated epoxy ester intermediate B, the waterborne epoxy ester resin composition can have both good grafting rate and relatively high oxidative crosslinking functionality, effectively improving the initial water resistance of the waterborne epoxy ester coating.

[0065] In order for the above-mentioned implementation details and operations of the present application to be clearly understood by those skilled in the art, and the initial water resistance of the waterborne epoxy ester resin composition of the present application and the preparation method thereof are significantly embodied, the implementation of the present application is exemplified by the following examples.

[0066] The raw materials involved in the examples and comparative examples include:

[0067] NPES-901 epoxy resin, NPES-904 epoxy resin, NPES-907 epoxy resin, industrial grade, Nanya Electronic Materials (Kunshan) Co., Ltd.; ethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol butyl ether, industrial grade, Nanjing Gutian Chemical Co., Ltd.; ethylene glycol tert-butyl ether, industrial grade, Japan Maruzen; mesitylene, methyl isobutyl ketone, chemical pure, Shanghai Aladdin Biochemical Technology Co., Ltd.; C9 aromatic hydrocarbon, industrial grade, Nanjing Refinery Co., Ltd.; monobutyl tin oxide, industrial grade, Shanghai Titan Science and Technology Co., Ltd.; 2,6-di-tert-butyl-p-cresol, ultrapure grade, Shanghai Aladdin Biochemical Technology Co., Ltd.; triphenylphosphine, industrial grade, Shanghai Lingfeng Chemical Reagent Co., Ltd.; oleic acid, linoleic acid, linolenic acid, chemical pure, Shanghai Maikelin Biochemical Technology Co., Ltd.; tung oil acid, dehydrated castor oil acid, soybean oil acid, acrylic acid, methacrylic acid, styrene, butyl methacrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl acrylate, industrial grade, China Oceanic Oil Changzhou Environmental Protection Coating Co., Ltd.; di-tert-amyl peroxide (DTAP), di-tert-butyl peroxide (DTBP), 1,1-di-tert-butyl peroxide-3,3,5-trimethylcyclohexane (TMCH), tert-butyl peroxybenzoate (TBPB), industrial grade, AkzoNobel; tert-amyl peroxy-2-ethylhexanoate (TAPO), industrial grade, Shandong Haijing New Material Co., Ltd.; 2,2-di-(tert-butyl peroxide) butane, industrial grade, Nantong Runfeng Petroleum Chemical Co., Ltd.; N,N-dimethylethanolamine (DMEA), industrial grade, United States Eastman; AMP-95, industrial grade, United States Dow; high-efficiency composite catalyst drier TY-CQ-88A, industrial grade, Shanghai Taoyuan Cobalt Co., Ltd.; BYK-190, BYK-022, BYK-346, industrial grade, BYK Company; carbon black, industrial grade, Degussa; titanium dioxide R-902+, industrial grade, United States DuPont; precipitated barium sulfate, industrial grade, Nanfeng Group; Nubirox 106, industrial grade, NuBrida; Airex 901W, industrial grade, DiGao; ACRYSOL TM RM-8W, industrial grade, Dow Chemical. The raw materials used in the examples and comparative examples are commercially available products, which can be purchased through commercial channels, unless otherwise specified.

[0068] Example 1

[0069] Preparation of conjugated epoxy ester intermediate A1 : In a reactor with stirrer and thermometer, 30.93 grams of tung oil acid, 55.62 grams of NPES-901 epoxy resin, 0.09 grams of polymerization inhibitor 2,6-di-tert-butyl-p-cresol and 0.87 grams of catalyst triphenylphosphine were added, and the ring-opening esterification reaction was carried out under nitrogen protection, stirring and heating to 140±5°C, and after 5 hours of incubation, the reaction temperature was lowered to 90°C, and 37.49 grams of ethylene glycol tert-butyl ether were added to obtain epoxy ester intermediate A1.

[0070] Example 2

[0071] Preparation of conjugated epoxy ester intermediate A2: In a reactor with stirrer and thermometer, 25.26 grams of dehydrated castor oil acid, 45.13 grams of NPES-901 epoxy resin, 0.21 grams of polymerization inhibitor 2,6-di-tert-butyl-p-cresol and 1.40 grams of catalyst triphenylphosphine were added, and the ring-opening esterification reaction was carried out under nitrogen protection, stirring and heating to 140±5°C, and after 5 hours of incubation, the reaction temperature was lowered to 95°C, and 28 grams of ethylene glycol butyl ether were added to obtain epoxy ester intermediate A2.

[0072] Example 3

[0073] Preparation of conjugated epoxy ester intermediate A3: Preparation of non-conjugated epoxy ester intermediate B: In a reactor with stirrer and thermometer, 24.13 grams of tung oil acid, 43.4 grams of NPES-901 epoxy resin, 0.33 grams of polymerization inhibitor 2,6-di-tert-butyl-p-cresol and 0.14 grams of catalyst triphenylphosphine were added, and the ring-opening esterification reaction was carried out under nitrogen protection, stirring and heating to 140±5°C, and after 5 hours of incubation, the reaction temperature was lowered to 90°C, and 32 grams of ethylene glycol tert-butyl ether were added to obtain epoxy ester intermediate A3.

[0074] Example 4

[0075] Preparation of non-conjugated epoxy ester intermediate B1 : 109.21 grams of soybean oil acid, 99.33 grams of NPES-904 epoxy resin, 2.09 grams of triphenylphosphine, 10.43 grams of mesitylene were added to a reaction vessel with a water separator, and the temperature was slowly raised to 100-130°C to melt the epoxy resin, stirring was started, and the temperature was gradually raised to 210°C at a rate of 20°C / hour, and after incubation at 210±5°C for 5 hours, the temperature was lowered to 160-180°C, vacuum was applied to remove the mesitylene, and the temperature was lowered to 90-100°C, and 89.37 grams of ethylene glycol tert-butyl ether were added while stirring to obtain non-conjugated epoxy ester intermediate B1.

[0076] Example 5

[0077] Preparation of non-conjugated epoxy ester intermediate B2: Put 69.7 grams of oleic acid and 140.1 grams of linoleic acid, 139.41 grams of NPES-901 epoxy resin, 34.85 grams of NPES-907 epoxy resin, 7.68 grams of triphenylphosphine, 19.2 grams of C9 aromatic hydrocarbon into a reaction vessel with a water trap, start to slowly raise the temperature to 100-130°C, keep the temperature for 1 hour to melt the epoxy resin, start to stir, gradually raise the temperature to 220°C at a temperature raising speed of 20°C / hour, keep the temperature at 220±5°C for 5 hours, then lower the temperature to 160-180°C, vacuumize to remove the C9 aromatic hydrocarbon, lower the temperature to 90-100°C, while stirring, add 69.70 grams of ethylene glycol butyl ether and 58.55 grams of ethylene glycol tert-butyl ether, to obtain non-conjugated epoxy ester intermediate B2.

[0078] Example 6

[0079] Preparation of non-conjugated epoxy ester intermediate B3: Put 175.85 grams of linolenic acid, 100.91 grams of NPES-904 epoxy resin, 43.24 grams of NPES-907 epoxy resin, 9.6 grams of monobutyl tin oxide, 25.6 grams of methyl isobutyl ketone into a reaction vessel with a water trap, start to slowly raise the temperature to 100-130°C, keep the temperature for 1 hour to melt the epoxy resin, start to stir, gradually raise the temperature to 220°C at a temperature raising speed of 20°C / hour, keep the temperature at 220±5°C for 5 hours, then lower the temperature to 160-180°C, vacuumize to remove the methyl isobutyl ketone, lower the temperature to 90-100°C, while stirring, add 92.73 grams of propylene glycol butyl ether and 72.07 grams of propylene glycol methyl ether, to obtain non-conjugated epoxy ester intermediate B3.

[0080] Examples 7-11 and Comparative Examples 1-6 below are based on the synthesis of Examples 1-6, and are directed to the preparation of waterborne epoxy ester resin compositions with initial water resistance. It should be noted that before the synthesis of the waterborne epoxy ester resin compositions with initial water resistance, the mixed monomer components are prepared according to the formulation in any of the above examples, which include the first component, the second component, and the third component. Among them, the first component includes the hydrophilic vinyl monomer D and the initiator E; the second component includes the non-hydrophilic vinyl monomer F and the initiator G; and the third component includes the initiator H and the solvent I.

[0081] Example 7

[0082] The preparation method of the waterborne epoxy ester resin composition a comprises the following steps: according to the component formula in Table 1, 125 grams of epoxy ester intermediate A1 is mixed with 300 grams of epoxy ester intermediate B1, after uniform stirring, the temperature is raised to 115-125 DEG C, and the mixed monomer component is started to be added dropwise. First, the first component containing the hydrophilic vinyl monomer D is added dropwise, and the addition is completed within 0.5-1.5 hours at 115-125 DEG C; after the addition of the first component is completed, the second component containing the non-hydrophilic vinyl monomer F is continuously added dropwise at 115-125 DEG C, and the addition is completed within 3-4 hours; then the temperature is adjusted to 130-140 DEG C, the third component containing the initiator H is added dropwise, the addition is completed within 1-2 hours, after the addition is completed, the temperature is kept at 130-140 DEG C for 1-2 hours, the temperature is lowered to 90-100 DEG C, and the neutralizing agent C is added, thereby preparing the waterborne epoxy ester resin composition a.

[0083] Example 8

[0084] The preparation method of the waterborne epoxy ester resin composition b comprises the following steps: according to the component formula in Table 1, 100 grams of epoxy ester intermediate A2 is mixed with 350 grams of epoxy ester intermediate B2, after uniform stirring, the temperature is raised to 110-120 DEG C, and the mixed monomer component is started to be added dropwise. First, the first component containing the hydrophilic vinyl monomer D is added dropwise, and the addition is completed within 0.5-1.5 hours at 110-120 DEG C; after the addition of the first component is completed, the second component containing the non-hydrophilic vinyl monomer F is continuously added dropwise at 110-120 DEG C, and the addition is completed within 3-4 hours; then the temperature is adjusted to 145-150 DEG C, the third component containing the initiator H is added dropwise, the addition is completed within 1-2 hours, after the addition is completed, the temperature is kept at 145-150 DEG C for 1-2 hours, the temperature is lowered to 90-100 DEG C, and the neutralizing agent C is added, thereby preparing the waterborne epoxy ester resin composition b.

[0085] Example 9

[0086] The preparation method of the waterborne epoxy ester resin composition c comprises the following steps: according to the component formula in Table 1, 100 grams of epoxy ester intermediate A1 is mixed with 200 grams of epoxy ester intermediate B3, after uniform stirring, the temperature is raised to 125-135 DEG C, and the mixed monomer component is started to be added dropwise. First, the first component containing the hydrophilic vinyl monomer D is added dropwise, and the addition is completed within 0.5-1.5 hours at 125-135 DEG C; after the addition of the first component is completed, the second component containing the non-hydrophilic vinyl monomer F is continuously added dropwise at 125-135 DEG C, and the addition is completed within 3-4 hours; then the temperature is adjusted to 140-145 DEG C, the third component containing the initiator H is added dropwise, the addition is completed within 1-2 hours, after the addition is completed, the temperature is kept at 140-145 DEG C for 1-2 hours, the temperature is lowered to 90-100 DEG C, and the neutralizing agent C is added, thereby preparing the waterborne epoxy ester resin composition c.

[0087] Example 10

[0088] The preparation method of the water-based epoxy ester resin composition d includes the following steps: according to the component formula of Table 1, 150 grams of epoxy ester intermediate A3 is mixed with 320 grams of epoxy ester intermediate B2, after stirring uniformly, the temperature is raised to 125-135°C, and the mixed monomer component is started to be added dropwise. First, the first component containing the hydrophilic vinyl monomer D is added dropwise, and the addition is completed within 0.5-1.5 hours at 125-135°C; after the addition of the first component is completed, the second component containing the non-hydrophilic vinyl monomer F is continuously added dropwise at 125-135°C, and the addition is completed within 3-4 hours; then the temperature is adjusted to 130-140°C, the third component containing the initiator H is added dropwise, the addition is completed within 1-2 hours, after the addition is completed, the temperature is kept at 130-140°C for 1-2 hours, the temperature is lowered to 90-100°C, and the neutralizing agent C is added, thereby preparing the water-based epoxy ester resin composition d.

[0089] Example 11

[0090] The preparation method of the water-based epoxy ester resin composition e includes the following steps: according to the component formula of Table 1, 110 grams of epoxy ester intermediate A2 is mixed with 220 grams of epoxy ester intermediate B3, after stirring uniformly, the temperature is raised to 130-140°C, and the mixed monomer component is started to be added dropwise. First, the first component containing the hydrophilic vinyl monomer D is added dropwise, and the addition is completed within 0.5-1.5 hours at 130-140°C; after the addition of the first component is completed, the second component containing the non-hydrophilic vinyl monomer F is continuously added dropwise at 130-140°C, and the addition is completed within 3-4 hours; then the temperature is adjusted to 140-150°C, the third component containing the initiator H is added dropwise, the addition is completed within 1-2 hours, after the addition is completed, the temperature is kept at 140-150°C for 1-2 hours, the temperature is lowered to 90-100°C, and the neutralizing agent C is added, thereby preparing the water-based epoxy ester resin composition e.

[0091] Table 1 Raw material composition and formula of the water-based epoxy ester resin composition with initial water resistance in Examples 7 to 11

[0092]

[0093] Comparative Example 1

[0094] The preparation method of the waterborne epoxy ester resin composition f includes the following steps: according to the component formula in Table 1, 425 grams of epoxy ester intermediate A1 is stirred uniformly, and then heated to 115-125°C, and the mixed monomer component is started to be added dropwise. First, the first component containing the hydrophilic vinyl monomer D is added dropwise, and the addition is completed within 0.5-1.5 hours at 115-125°C; after the addition of the first component is completed, the second component containing the non-hydrophilic vinyl monomer F is continuously added dropwise at 115-125°C, and the addition is completed within 3-4 hours; then the temperature is adjusted to 130-140°C, and the third component containing the initiator H is added dropwise, and the addition is completed within 1-2 hours; after the addition is completed, the temperature is kept at 130-140°C for 1-2 hours, the temperature is lowered to 90-100°C, and the neutralizing agent C is added. During the addition of the mixed monomer component, the viscosity of the waterborne epoxy ester resin is too large to climb the pole and gel, and the reaction is stopped.

[0095] Comparative Example 2

[0096] The preparation method of the waterborne epoxy ester resin composition g includes the following steps: according to the component formula in Table 2, according to the component formula in Table 1, 425 grams of epoxy ester intermediate B1 is stirred uniformly, and then heated to 115-125°C, and the mixed monomer component is started to be added dropwise. First, the first component containing the hydrophilic vinyl monomer D is added dropwise, and the addition is completed within 0.5-1.5 hours at 115-125°C; after the addition of the first component is completed, the second component containing the non-hydrophilic vinyl monomer F is continuously added dropwise at 115-125°C, and the addition is completed within 3-4 hours; then the temperature is adjusted to 130-140°C, and the third component containing the initiator H is added dropwise, and the addition is completed within 1-2 hours; after the addition is completed, the temperature is kept at 130-140°C for 1-2 hours, the temperature is lowered to 90-100°C, and the neutralizing agent C is added. During the addition of the mixed monomer component, the viscosity of the waterborne epoxy ester resin is too large to climb the pole and gel, and the reaction is stopped.

[0097] Comparative Example 3

[0098] The preparation method of the waterborne epoxy ester resin composition h includes the following steps: according to the component formula in Table 2, 425 grams of epoxy ester intermediate X is stirred uniformly, and then heated to 115-125°C, and the mixed monomer component is started to be added dropwise. First, the first component containing the hydrophilic vinyl monomer D is added dropwise, and the addition is completed within 0.5-1.5 hours at 115-125°C; after the addition of the first component is completed, the second component containing the non-hydrophilic vinyl monomer F is continuously added dropwise at 115-125°C, and the addition is completed within 3-4 hours; then the temperature is adjusted to 130-140°C, and the third component containing the initiator H is added dropwise, and the addition is completed within 1-2 hours; after the addition is completed, the temperature is kept at 130-140°C for 1-2 hours, the temperature is lowered to 90-100°C, and the neutralizing agent C is added. During the addition of the mixed monomer component, the viscosity of the waterborne epoxy ester resin is too large to climb the pole and gel, and the reaction is stopped.

[0099] The preparation process of the epoxy ester intermediate X is as follows: 30.93 grams of tung oil acid, 109.21 grams of soybean oil acid, 55.62 grams of NPES-901 epoxy resin, 99.33 grams of NPES-904 epoxy resin, 2.96 grams of catalyst triphenylphosphine, 0.09 grams of polymerization inhibitor 2,6-di-tert-butyl-p-cresol, and 10.43 grams of mesitylene are added into a reaction container with a water trap, and the temperature is slowly increased to 100-130°C. The epoxy resin is melted for 1 hour. The temperature is slowly increased to 100-130°C. The stirring is started. The temperature is gradually increased to 220°C at a rate of 20°C / hour. After being kept at 220±5°C for 5 hours, the temperature is decreased to 160-180°C. The mesitylene is removed by vacuum extraction. The temperature is decreased to 90-100°C. While stirring, 126.86 grams of ethylene glycol tert-butyl ether is added to prepare the epoxy ester intermediate X.

[0100] Comparative Example 4

[0101] The preparation method of the water-based epoxy ester resin composition i includes the following steps: 125 grams of the epoxy ester intermediate A1 and 300 grams of the epoxy ester intermediate B1 are mixed according to the component formula in Table 2. After being uniformly stirred, the temperature is increased to 115-125°C. The mixed monomer component is started to be added dropwise. The first component containing the hydrophilic vinyl monomer D and the second component containing the non-hydrophilic vinyl monomer F are mixed and then added dropwise at the same time. The dropwise adding temperature is still kept at 115-125°C. The dropwise adding time is controlled to be 4-5 hours. Then the temperature is adjusted to 130-140°C. The third component containing the initiator H is added dropwise. The dropwise adding is ended within 1-2 hours. After the dropwise adding is ended, the temperature is kept at 130-140°C for 1-2 hours. The temperature is decreased to 90-100°C. The neutralizing agent C is added to prepare the water-based epoxy ester resin composition i.

[0102] Comparative Example 5

[0103] The preparation method of the water-based epoxy ester resin composition j includes the following steps: 125 grams of the epoxy ester intermediate A1 and 300 grams of the epoxy ester intermediate B1 are mixed according to the component formula in Table 2. After being uniformly stirred, the temperature is increased to 115-125°C. The mixed monomer component is started to be added dropwise. The second component containing the non-hydrophilic vinyl monomer F is first added dropwise. The dropwise adding is ended within 3-4 hours at 115-125°C. The first component containing the hydrophilic vinyl monomer D is then added dropwise. The dropwise adding is ended within 0.5-1.5 hours at 115-125°C. Then the temperature is adjusted to 130-140°C. The third component containing the initiator H is added dropwise. The dropwise adding is ended within 1-2 hours. After the dropwise adding is ended, the temperature is kept at 130-140°C for 1-2 hours. The temperature is decreased to 90-100°C. The neutralizing agent C is added to prepare the water-based epoxy ester resin composition j.

[0104] Comparative Example 6

[0105] The preparation method of the waterborne epoxy ester resin composition k comprises the following steps: the formulation and process of Comparative Example 6 are similar to those of Example 7, the total monomer composition is completely consistent, and the only difference is that the composition and respective dropping time of the “first component containing hydrophilic vinyl monomer D” and the “second component containing non-hydrophilic vinyl monomer F” in Comparative Example 6 are adjusted, wherein the composition of the “first component containing hydrophilic vinyl monomer D” is modified from “35.0 grams of acrylic acid and 0.7 grams of TBPB” to “15 grams of acrylic acid, 50.0 grams of styrene, 30 grams of 2-ethylhexyl acrylate, 50 grams of methyl methacrylate, and 2.9 grams of TBPB”, and the composition of the “second component containing non-hydrophilic vinyl monomer F” is modified from “150.0 grams of styrene, 85 grams of 2-ethylhexyl acrylate, 130 grams of methyl methacrylate, and 5.0 grams of TBPB” to “20 grams of acrylic acid, 100 grams of styrene, 55 grams of 2-ethylhexyl acrylate, 80 grams of methyl methacrylate, and 2.8 grams of TBPB”, and other formulation and process conditions are completely the same as those of Example 7. The waterborne epoxy ester resin composition EPE-06 is prepared, and the waterborne epoxy ester resin composition k is prepared.

[0106] Table 2 shows the raw material composition and formulation of the waterborne epoxy ester resin composition with initial water resistance in Comparative Examples 1 to 5

[0107]

[0108] Preparation of waterborne epoxy ester coatings: the waterborne epoxy ester resin compositions prepared in Examples 7-11 and Comparative Examples 2-6 above are used as film-forming resins to prepare waterborne epoxy ester coatings. The formulation of the waterborne epoxy ester coatings is shown in Table 3, and the preparation process of the waterborne epoxy ester coatings is as follows:

[0109] (1) According to the formulation in Table 3, first, the film-forming resin (waterborne epoxy ester resin composition a, b, c, d, e in the examples and waterborne epoxy ester resin composition g, h, i, j, k in the comparative examples), the catalyst (TY-CQ-88A), and the pH adjuster (N,N-dimethyl ethanolamine) are stirred and mixed uniformly, the stirring speed is 1000 rpm, deionized water is added under stirring, and after stirring for 30 min, a waterborne epoxy ester dispersion is obtained;

[0110] (2) The materials 5-12 in Table 3 are sequentially added in a reaction tank, added into a stirred tank, and mixed and stirred for 40-60 min, and then ground until the fineness is <30 μm;

[0111] (3) while stirring, add the material 13, adjust the viscosity, filter the material, and obtain the water-based epoxy ester coating, filter, discharge, and package. The prepared coatings are sequentially denoted as Ca, Cb, Cc, Cd, Ce, and comparative coating Cg, Ch, Ci, Cj, Ck according to the used water-based epoxy ester resin composition.

[0112] Table 3 Water-based epoxy ester coating formula

[0113]

[0114] The water-based epoxy ester coating is prepared and the coating performance is tested according to the corresponding national standard: the prepared water-based epoxy ester coating is diluted with water to the appropriate viscosity, the coating is sprayed on the polished cold-rolled steel plate, the film thickness is controlled at 50-60 μm, after air-drying at room temperature, the sample plate is placed in an oven at 80±2 ℃ for 30 min, and after standing at room temperature for 7 days, the performance of the coating is tested according to the coating national standard test method.

[0115] In addition, the water-based epoxy ester resin prepared in the above examples and comparative examples is characterized, and the rotational viscosity, gel content and monomer conversion rate of the resin composition are tested respectively. The appearance, air-drying time, adhesion, water resistance, initial water resistance and neutral salt spray resistance of the coating are tested.

[0116] Rotational viscosity: the rotational viscosity of the resin is tested using an NDJ-8S rotational viscometer.

[0117] Viscosity of water-based epoxy ester dispersion: to test the workability and dispersibility of the resin in the preparation of the coating, the water-based epoxy ester resin composition is weighed in a metered ratio, deionized water is added while stirring, the water-based epoxy ester dispersion is prepared, the solid content is 42.5%, and the rotational viscosity of the resin is tested.

[0118] Dispersion heat storage stability: abbreviated as dispersion heat storage. To test the storage stability of the epoxy ester modified water-based alkyd resin, the water-based epoxy ester resin composition is weighed in a metered ratio, deionized water is added while stirring, the water-based epoxy ester dispersion is prepared, the solid content is 42.5%, and it is placed in a constant temperature drying oven at 50±2 ℃, and every 24 h, whether it is layered, settled, coagulated, precipitated, agglomerated, etc. is observed. If any of the above phenomena occurs, it is determined that the storage stability is poor.

[0119] Gel content: The grafting rate of the resin was characterized by the gel content. The specific test method was as follows: the aqueous epoxy ester resin composition was weighed, 5wt% of TY-CQ-88A catalyst was added, and after stirring uniformly, a film was formed on a tetrafluoroethylene plate, after surface drying, it was baked at 80℃ for 2 hours, and then placed at 25±2℃ for 7 days, after the above solid resin was collected and weighed, the mass was recorded as M0g, Soxhlet extraction was carried out, and after the sample was dried and weighed after extraction, M1 was obtained, the gel content = (M0-M1) / M0x100%.

[0120] Residual monomer content: the residual monomer content was determined using an Agilent 8890 gas chromatograph.

[0121] Initial water resistance: after the sample plate was sprayed and dried in a standard 25±2℃ constant temperature and humidity chamber for 24h, the sample plate was placed in deionized water in a 25±2℃ constant temperature room after edge treatment, about 2 / 3 of the sample plate was immersed in water, the coating film state was observed every 2h within 24h, and then once every 12h after 24h, until the coating film was blistered, wrinkled or the substrate was rusted, and the initial water resistance was judged by the time of coating film damage.

[0122] Neutral salt spray resistance test: the corrosion resistance of the coating was determined by the neutral salt spray resistance test, according to GB / T1771-2007, the plate was checked every 24h until the coating film blistered, rusted or fell off.

[0123] Other properties of the coating were tested according to the corresponding national standards, and the related test results are shown in Tables 4 and 5.

[0124] Table 4 Test results of the aqueous epoxy ester resin composition with initial water resistance in Examples 7 to 11 and Comparative Examples 1 to 6

[0125]

[0126] Table 5 Test results of the aqueous epoxy ester coating performance in Examples 7 to 11 and Comparative Examples 2 to 6

[0127]

[0128] From the analysis in Table 4, it can be seen that the rotational viscosity of the aqueous epoxy ester resin composition resin prepared in the examples of the present application is less than 60000mPa.s, the gel content is higher than 54%, the viscosity of the dispersion (solid content 42.5%) is less than 1000mPa.s, the viscosity is moderate, and the paint preparation is convenient.

[0129] As can be seen from Table 5, the waterborne epoxy ester resin composition prepared by the technical scheme is used as a film-forming material to prepare a waterborne epoxy ester coating, and the coating has excellent performance. The coating has a smooth appearance, and the pencil hardness of the coating is all more than HB, meeting the requirements of industrial primers. In particular, it is pointed out that, by segmented dropping of the hydrophilic component and the hydrophobic component, the neutral salt spray resistance of the waterborne epoxy ester coating prepared by the technical scheme reaches 300 h, the corrosion resistance is excellent, and the initial water resistance all reaches 72 h, meeting the latest requirements of the automobile parts field on the initial water resistance and the corrosion resistance.

[0130] Example 7 is compared with Comparative Example 1. Comparative Example 1 uses the epoxy ester intermediate A1 containing a conjugated double bond to prepare a waterborne epoxy ester. Since the conjugated double bond has high activity, Comparative Example 1 gels in the process of preparing the waterborne epoxy ester resin due to too large viscosity, and the waterborne epoxy ester resin cannot be prepared. Example 7 is compared with Comparative Example 2. Comparative Example 2 uses only the epoxy ester intermediate B1 not containing a conjugated double bond to prepare the waterborne epoxy ester resin g, and the gel content data decreases from 57.19% of Example 7 to 49.91% of Comparative Example 2. Since there is no conjugated double bond, the hydrophilic monomer is more uniformly distributed in the dropping process, and thus the viscosity of the waterborne epoxy ester dispersion also increases to 1350 mPa.s. The initial water resistance of the corresponding coating of the waterborne epoxy ester resin g in Comparative Example 2 decreases from 72 to 48 h, and the neutral salt spray resistance decreases to 240 h.

[0131] Example 7 is compared with Comparative Example 3. In Example 7, the epoxy ester intermediate A1 and the epoxy ester intermediate B1 are prepared by a two-step esterification method, and the waterborne epoxy ester resin composition a is prepared by using the “mixture of the epoxy ester intermediate A1 and the epoxy ester intermediate B1”. The rotational viscosity of the waterborne epoxy ester resin composition a is 43280 mPa.s. In Comparative Example 3, the epoxy ester intermediate X is prepared by a one-step esterification method, and the waterborne epoxy ester resin h is synthesized by using the epoxy ester intermediate X. Although the preparation process, the raw materials and the raw material amounts used in Example 6 and Comparative Example 3 are completely the same, the rotational viscosity of Comparative Example 3 reaches 95690 mPa.s, which is much higher than the viscosity of the waterborne epoxy ester resin composition a in Example 7, and is not conducive to the application of the resin. In addition, the gel content of the resin h prepared in Comparative Example 3 also decreases to 55.83%, which may be caused by the loss of the conjugated double bond in the high-temperature esterification process. Correspondingly, the initial water resistance and the neutral salt spray resistance of the waterborne epoxy ester coating corresponding to Comparative Example 3 also decrease.

[0132] Comparing Example 7 with Comparative Example 4, the formulation and process of Comparative Example 4 is similar to that of Example 7, the only difference is that the segmented dropping process of "first component containing hydrophilic vinyl monomer D and second component containing non-hydrophilic vinyl monomer F" in Example 7 is changed to "simultaneous dropping" in Comparative Example 4, other process conditions are exactly the same as Example 7. The waterborne epoxy ester resin composition prepared in Example 7 and Comparative Example 4 has similar rotational viscosity, gel content and residual monomer content. However, it is worth noting that the viscosity of the waterborne epoxy ester dispersion in Comparative Example 4 increases to 2450 mPa.s, which is not conducive to the preparation of coatings. The initial water resistance of the coating corresponding to the waterborne epoxy ester resin i in Comparative Example 4 is reduced from 72 h to 48 h, and the neutral salt spray resistance is reduced from 300 h to 240 h.

[0133] Comparing Example 7 with Comparative Example 5, the formulation and process of Comparative Example 5 is similar to that of Example 7, the only difference is that the dropping order of "first component containing hydrophilic vinyl monomer D" and "second component containing non-hydrophilic vinyl monomer F" in Comparative Example 5 is exchanged, other formulation and process conditions are exactly the same as Example 7. The dispersion prepared in Comparative Example 5 has a thermal storage stability of less than 48 h, which is due to the fact that during the polymerization of the hydrophilic monomer acrylic acid, the grafting points in the epoxy ester are already few, and most of the acrylic acid monomers are self-polymerized, resulting in fewer hydrophilic groups grafted onto the epoxy ester component, and poor water solubility. Correspondingly, due to the presence of more hydrophilic self-polymer, the initial water resistance of the coating corresponding to the waterborne epoxy ester resin j in Comparative Example 5 is reduced to 6 h, and the neutral salt spray resistance is reduced to 168 h.

[0134] Comparing Example 7 with Comparative Example 6, the formulation and process of Comparative Example 6 is similar to that of Example 7, the total monomer composition is exactly the same, the only difference is that the composition and dropping time of "first component containing hydrophilic vinyl monomer D" and "second component containing non-hydrophilic vinyl monomer F" in Comparative Example 5 are adjusted. Due to the fact that part of the hydrophilic vinyl monomer D is added in the second step, the total grafting rate of the hydrophilic group is reduced, and the initial water resistance and corrosion resistance of the corresponding coating are also reduced.

[0135] The above only describes the preferred embodiments of the present application and is not intended to limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A waterborne epoxy ester resin composition with initial water resistance, characterized in that, The raw material composition of the waterborne epoxy ester resin composition with initial water resistance, based on 100% of the total raw material mass, includes 42.86–67.63% of a mixed monomer component, 10–15% of a conjugated epoxy ester intermediate A, 20–35% of a non-conjugated epoxy ester intermediate B, and 2.5–5.5% of a neutralizing agent C. The mixed monomer component comprises a first component, a second component, and a third component. The first component comprises the following components in the following percentages: Hydrophilic vinyl monomer D 2.5–5%; Initiator E 0.05–0.13%; The second component comprises the following components in the following percentages: Non-hydrophilic vinyl monomers F35-45.5%; Initiator G: 0.25–1.5%; The third component comprises the following components in the following percentages: Initiator H: 0.06–0.5%; Solvent I5-15%, The raw material composition of the conjugated epoxy ester intermediate A includes fatty acid J, epoxy resin K, polymerization inhibitor L, catalyst M and solvent N. The fatty acid J is at least one of tung oil acid and dehydrated ricinoleic acid, and the epoxy resin K is a bisphenol A type epoxy resin with an epoxy value of 0.18 to 0.22 mol / 100g. The raw material composition of the non-conjugated epoxy ester intermediate B includes fatty acid O, epoxy resin P, catalyst Q, dehydrating solvent R, and diluting solvent S. The fatty acid O is at least one selected from oleic acid, linoleic acid, linolenic acid, and soybean oil. The epoxy resin P is a bisphenol A type epoxy resin with an epoxy value of 0.04–0.22 mol / 100g. In preparing the waterborne epoxy ester resin composition with initial water resistance, a two-step esterification method is designed to prepare conjugated epoxy ester intermediate A and non-conjugated epoxy ester intermediate B with different double bond types. The first component, the second component, and the third component are then added dropwise to the mixture of conjugated epoxy ester intermediate A and non-conjugated epoxy ester intermediate B in a segmented dropwise manner to graft and modify the two epoxy ester intermediates. The mixed monomers are added in the order of the first component, the second component, and the third component.

2. The waterborne epoxy ester resin composition with initial water resistance as described in claim 1, characterized in that, The total mass of fatty acid J and epoxy resin K accounts for 67-73% of the total mass of conjugated epoxy ester intermediate A, the solvent N accounts for 28-32% of the total mass of conjugated epoxy ester intermediate A, the polymerization inhibitor L accounts for 0.05-0.5% of the total mass of conjugated epoxy ester intermediate A, and the catalyst M accounts for 0.1-2% of the total mass of conjugated epoxy ester intermediate A.

3. The waterborne epoxy ester resin composition with initial water resistance as described in claim 1, characterized in that, The polymerization inhibitor L is at least one of 2,6-di-tert-butyl-p-cresol and hydroquinone, the catalyst M is triphenylphosphine, and the solvent N is at least one of ethylene glycol butyl ether, diethylene glycol butyl ether, ethylene glycol tert-butyl ether, propylene glycol methyl ether, propylene glycol butyl ether, and dipropylene glycol butyl ether.

4. The waterborne epoxy ester resin composition with initial water resistance as described in claim 1, characterized in that, The molar ratio of fatty acid J to epoxy resin K is (1.9~2.1):

1.

5. The waterborne epoxy ester resin composition with initial water resistance as described in claim 1, characterized in that, Based on the total mass percentage of fatty acid O and epoxy resin P being 100%, the mass percentage of catalyst Q is 0.1-3%, the mass percentage of dehydrating solvent R is 2-10%, and the mass percentage of diluent S is 30-55%.

6. The waterborne epoxy ester resin composition with initial water resistance as described in claim 1, characterized in that, The catalyst Q is at least one of triphenylphosphine, dibutyltin dilaurate, and monobutyltin oxide; the dehydrating solvent R is at least one of pseudotrimethylbenzene, mesitylene, C9 aromatic hydrocarbon, methyl isobutyl ketone, and solvent oil D40; and the diluent S is at least one of ethylene glycol butyl ether, diethylene glycol butyl ether, ethylene glycol tert-butyl ether, propylene glycol methyl ether, propylene glycol butyl ether, and dipropylene glycol butyl ether.

7. The waterborne epoxy ester resin composition with initial water resistance as described in claim 1, characterized in that, The mass ratio of fatty acid O to epoxy resin P is (60-122):

100.

8. The waterborne epoxy ester resin composition with initial water resistance as described in claim 1, characterized in that, The preparation process of the conjugated epoxy ester intermediate A is as follows: In a reactor equipped with a stirrer and a thermometer, fatty acid J, epoxy resin K, polymerization inhibitor L and catalyst M are added. Under nitrogen protection, the mixture is stirred and heated to 135-145°C to carry out a ring-opening esterification reaction. After holding at this temperature for 5 hours, the reaction temperature is lowered to 90-95°C, and solvent N is added to obtain the conjugated epoxy ester intermediate A.

9. The waterborne epoxy ester resin composition with initial water resistance as described in claim 1, characterized in that, The preparation process of the non-conjugated epoxy ester intermediate B is as follows: fatty acid O, epoxy resin P, catalyst Q, and dehydrating solvent R are added to a reaction vessel equipped with a water separator. The temperature is slowly raised to 100-130°C and held for 1 hour until epoxy resin P is completely melted. The mixture is stirred and gradually heated to 200-230°C at a rate of 20°C / hour. After holding for 5 hours, the temperature is lowered to 160-180°C, and the dehydrating solvent R is removed by vacuuming. Then, the temperature is lowered to 90-100°C, and the diluent S is added while stirring to obtain the non-conjugated epoxy ester intermediate B.

10. A method for preparing a waterborne epoxy ester resin composition with initial water resistance, characterized in that, Includes the following steps: Step S01: Weigh each of the raw materials according to any one of claims 1 to 9 for the components contained in the waterborne epoxy ester resin composition with initial water resistance; Step S02: Mix conjugated epoxy ester intermediate A with non-conjugated epoxy ester intermediate B, and stir until homogeneous to obtain epoxy ester intermediate mixture. Step S03: Heat the epoxy ester intermediate mixture to 110-140°C, and add a mixed monomer component dropwise to the epoxy ester intermediate mixture; the mixed monomer component includes a first component, a second component, and a third component. During the dropwise addition of the mixed monomer component to the epoxy ester intermediate mixture, the first component is added dropwise over 0.5-1.5 hours, followed by the second component over 3-4 hours. Then, the temperature of the epoxy ester intermediate mixture is adjusted to 130-150°C, and the third component is added dropwise over 1-2 hours. Step S04: The epoxy ester intermediate mixture containing the mixed monomer components is kept at 130-150°C for 1-2 hours, then cooled to 90-100°C, and neutralizing agent C is added to prepare an aqueous epoxy ester resin composition with initial water resistance.

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