Oxidized tertiary amine epoxy phenol resin, and preparation method and application thereof

Abstract

The application provides an oxidized tertiary amine epoxy phenolic resin and a preparation method and application thereof. The preparation steps comprise the following steps: dissolving a preset epoxy phenolic resin in a polar solvent dissolved in water to form an epoxy phenolic resin solution; adding a protonic acid ring-opening reagent drop by drop into the epoxy phenolic resin solution in an ice water bath and at a temperature not higher than 10 DEG C, and then performing a reaction at room temperature to form a tertiary amine group epoxy phenolic resin solution; and adding an oxidizing agent drop by drop into the solution to perform an oxidation reaction and form the oxidized tertiary amine epoxy phenolic resin. The application can realize flexible ring opening of an epoxy group, and the whole reaction process does not need heating, and the energy consumption is low. In addition, by controlling the ratio of the epoxy group and the oxidized tertiary amino group, the solubility of the product in different solvents can be adjusted, and the application range of the product is widened. The oxidized tertiary amine epoxy phenolic resin has an oxidized tertiary amino group, an epoxy group and a phenolic hydroxyl group, and can be applied to a printing CTP printing plate coating and 3D printing.

Description

Technical Field

[0001] This invention belongs to the field of resin manufacturing technology, specifically relating to a method for preparing an oxidized tertiary amine epoxy phenolic resin, an oxidized tertiary amine epoxy phenolic resin, and the application of an oxidized tertiary amine epoxy phenolic resin. Background Technology

[0002] Currently, existing methods for synthesizing tertiary amine oxide-modified epoxy phenolic resins are costly and extremely complex. For example, the traditional synthesis of tertiary amine oxide-modified epoxy phenolic resins involves two long, high-temperature steps: first, ring-opening of the epoxy groups by dimethylamine at 80°C for 12 hours; second, oxidation of the tertiary amine groups by hydrogen peroxide at 80°C for 12 hours. This process increases time and energy costs, resulting in high energy consumption. Furthermore, the epoxy groups in the tertiary amine oxide-modified epoxy phenolic resins synthesized by traditional methods are almost entirely ring-opened, which has limitations and significantly reduces the activity of the resulting product. Moreover, epoxy phenolic resins are limited to F-44, which has a low softening point, and the ring-opening reagent is also limited to dimethylamine. Furthermore, the active groups of tertiary amine oxide-modified epoxy phenolic resins synthesized by traditional methods are only tertiary amine oxides. The only chemical property of this group is thermal decomposition. Before and after thermal decomposition, the polymer simply changes from water-soluble to oil-soluble; the polymer backbone remains linear and no cross-linking structure is formed. This severely limits its solubility in different solvents, making it much less soluble than before modification. Moreover, the glass transition temperature of tertiary amine oxide-modified epoxy phenolic resins synthesized by traditional methods is relatively low, not exceeding 40°C. This significantly restricts its application range.

[0003] Furthermore, the use of tertiary amine oxide-modified epoxy phenolic resin synthesized using existing technologies for 3D printing consumables and CTP plate coatings also presents numerous problems. For example, most 3D printing consumables are hot-melt materials made of linear polymers, whose strength is significantly inferior to that of cross-linked polymers. Additionally, the use of linear polymers in 3D printing causes air pollution during the resin melting process. Therefore, traditionally synthesized tertiary amine oxide-modified epoxy phenolic resins cannot be used for 3D printing consumables. Moreover, most resins currently used for printing CTP plate coatings and forming images are also linear polymers, whose solvent resistance is significantly inferior to that of cross-linked polymers. Furthermore, the use of linear polymers in CTP plate coatings causes water pollution during the development and imaging process with strong alkaline solutions. To address these issues, it is necessary to propose a new method for synthesizing tertiary amine oxide-modified epoxy phenolic resins to reduce energy consumption and expand their application range. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art, and provides a method for preparing tertiary amine epoxy phenolic resin, a tertiary amine epoxy phenolic resin, and the application of a tertiary amine epoxy phenolic resin.

[0005] In a first aspect, the present invention provides a method for preparing an oxidized tertiary amine epoxy phenolic resin, the specific preparation steps of which include:

[0006] Take 15g to 25g of the pre-set epoxy phenolic resin and dissolve it in a polar solvent that is soluble in water to form an epoxy phenolic resin solution.

[0007] 2g to 10g of protic acid ring-opening reagent is added dropwise to the epoxy phenolic resin solution in an ice-water bath at a temperature not exceeding 10°C, and then the reaction is carried out at room temperature for 3h to 6h to form a tertiary amine epoxy phenolic resin solution.

[0008] 2g to 18g of oxidant is added dropwise to the tertiary amine epoxy phenolic resin solution to carry out an oxidation reaction, thereby forming the oxidized tertiary amine epoxy phenolic resin.

[0009] Optionally, the preset epoxy phenolic resin is an epoxy phenolic resin with a softening point range of 85℃~95℃ and an epoxy value of not less than 220g / eq.

[0010] Optionally, the water-soluble polar solvent is any one of N,N-dimethylformamide, N,N-diethylformamide, 1,4-butyrolactone, 1,4-dioxane, methanol, ethanol, isopropanol, and acetone.

[0011] Optionally, the protic acid ring-opening reagent is any one of dimethylamine ring-opening reagent, diethylamine ring-opening reagent, methyl ethylamine ring-opening reagent, dipropylamine ring-opening reagent, and dibutylamine ring-opening reagent.

[0012] Optionally, the step of adding 2g to 18g of oxidant to the tertiary amine epoxy phenolic resin solution for oxidation reaction to form the oxidized tertiary amine epoxy phenolic resin includes:

[0013] In a room temperature water bath, 2g to 18g of oxidant is added dropwise to the tertiary amine epoxy phenolic resin solution to carry out the oxidation reaction, and the reaction temperature is controlled not to exceed 50°C.

[0014] After the oxidant is added, the reaction is carried out for 5 to 7 hours to obtain the oxidized tertiary amine epoxy phenolic resin.

[0015] Optionally, the step of adding 2g to 18g of oxidant to the tertiary amine epoxy phenolic resin solution in a room temperature water bath to carry out the oxidation reaction, and controlling the reaction temperature to not exceed 50°C, further includes:

[0016] Add 0.4g to 6g of acidic decelerating agent to the tertiary amine epoxy phenolic resin solution to adjust the pH value of the solution.

[0017] Optionally, the oxidant includes any one of 2,3-dichloro-5,6-dicyanobenzoquinone, hydrogen peroxide, di(peracetic acid)iodobenzene, oxygen, N-halosuccinimide, and tert-butylhydrogen peroxide; and / or,

[0018] The acidic deceleration aid includes any one of citric acid, tartaric acid, lauric acid, and palmitic acid.

[0019] In a second aspect, the present invention provides an oxidized tertiary amine epoxy phenolic resin, which is prepared by the preparation method described above.

[0020] Optionally, the tertiary amine oxide epoxy phenolic resin includes phenolic hydroxyl groups, epoxy groups, and tertiary amine oxide groups.

[0021] A third aspect of the present invention provides an application of an oxidized tertiary amine epoxy phenolic resin, wherein the oxidized tertiary amine epoxy phenolic resin described above is applied to a CTP printing plate coating or 3D printing.

[0022] The preparation method of the oxidized tertiary amine epoxy phenolic resin of this invention includes: dissolving a pre-selected epoxy phenolic resin in a water-soluble polar solvent to form an epoxy phenolic resin solution. The water-soluble polar solvent can fully dissolve the epoxy phenolic resin and allow for a controllable effect in subsequent reactions. Then, a protic acid ring-opening reagent is added dropwise to the epoxy phenolic resin solution in an ice-water bath at a temperature not exceeding 10°C. The reaction is then carried out at room temperature for 3-6 hours to form a tertiary amine epoxy phenolic resin solution. In this embodiment, the ring-opening reaction is carried out at room temperature, eliminating the need for high temperatures or heating processes, thus shortening the reaction time and reducing energy consumption. Furthermore, to control the rapid decomposition of the oxidant, this invention involves adding the oxidant dropwise to the tertiary amine epoxy phenolic resin solution to carry out the oxidation reaction, forming an oxidized tertiary amine epoxy phenolic resin. This achieves the purpose of controlling the reaction rate and realizes the controllability of the tertiary amine oxidation. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating the preparation process of an oxidized tertiary amine epoxy phenolic resin according to the first embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram illustrating the change in epoxy equivalent with the amount of dimethylamine solution in a tertiary amine oxide epoxy phenolic resin according to the second embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram illustrating the change of epoxy equivalent in an oxidized tertiary amine epoxy phenolic resin with the amount of each secondary amine according to the third embodiment of the present invention.

[0026] Figure 4 This is a schematic diagram illustrating the change in epoxy equivalent with the amount of dimethylamine solution in a tertiary amine oxide epoxy phenolic resin according to the fourth embodiment of the present invention.

[0027] Figure 5 This is a Fourier transform infrared spectrum of a tertiary amine oxide epoxy phenolic resin modified to different degrees according to the fifth embodiment of the present invention;

[0028] Figure 6 The above are DSC curves and TG and DTG curves of a tertiary amine epoxy phenolic resin modified to different degrees according to the sixth embodiment of the present invention.

[0029] Figure 7 The DSC curve and TG and DTG curves are of an oxidized tertiary amine epoxy phenolic resin according to the seventh embodiment of the present invention.

[0030] Figure 8 This is a schematic diagram of the contact angle of an oxidized tertiary amine epoxy phenolic resin in a phase change printing plate according to the eighth embodiment of the present invention. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] This embodiment aims to obtain an epoxy phenolic resin possessing phenolic hydroxyl, epoxy, and tertiary amine oxide functional groups simultaneously. Since the parent epoxy phenolic resin itself possesses phenolic hydroxyl and epoxy groups, it is necessary to modify the parent epoxy phenolic resin to obtain an epoxy phenolic resin with all three functional groups. Specifically, this is achieved through ring-opening treatment of the epoxy group portion of the epoxy phenolic resin and further oxidation treatment to obtain the tertiary amine oxide epoxy phenolic resin of this embodiment. The tertiary amine oxide epoxy phenolic resin, its preparation method, and its applications will be described in detail below. It should be understood that this embodiment is for illustrative purposes only and is not limited to the scope of protection of this embodiment.

[0033] like Figure 1 As shown, in a first aspect, the present invention provides a method S100 for preparing an oxidized tertiary amine epoxy phenolic resin, specifically comprising the following steps S110 to S130:

[0034] S110. Take 15g to 25g of the pre-set epoxy phenolic resin and dissolve it in a polar solvent that is soluble in water to form an epoxy phenolic resin solution.

[0035] It should be noted that this embodiment involves two steps of polymer chemical reaction, therefore the selection of the parent polymer chain is particularly important. This embodiment uses a wide variety of parent epoxy phenolic resins, with epoxy values ​​generally ranging from 0.4 to 0.5 equivalents / 100g. The biggest difference lies in the resin's softening point. The softening point of a linear polymer determines its solution viscosity at a given temperature and concentration; a higher softening point results in greater viscosity at that temperature and concentration. Higher viscosity creates more obstacles to the polymer chemical reaction. Therefore, the selection of the matrix epoxy phenolic resin is crucial in the process of modifying epoxy phenolic resin with tertiary amine oxide. The key to selecting the epoxy phenolic resin to be modified is choosing its epoxy equivalent and glass transition temperature. The epoxy equivalent determines the reactivity of the modified resin, minimizing the loss of epoxy groups to achieve water solubility and broaden its application range. In addition, the glass transition temperature determines the mechanical properties of the modified epoxy phenolic resin, and even the mechanical properties of the image after the resin is cross-linked, such as impact resistance and friction resistance.

[0036] Specifically, most commonly used epoxy phenolic resins are Class F resins, with epoxy values ​​ranging from 0.4 to 0.5 equivalents / 100g and a wide range of softening points, which affects their application. Therefore, in this embodiment, the epoxy phenolic resin can be modified with a higher epoxy value and a higher glass transition temperature. This eliminates the influence of the reaction system viscosity on the modification effect and allows for controllability of the subsequent reaction process.

[0037] For example, this embodiment selects an epoxy resin with an epoxy value of not less than 220 g / eq, a glass transition temperature of not less than 90°C, and a softening point range of 85°C to 95°C. For instance, NPCN-704 epoxy phenolic resin is selected as the linear polymer matrix for polymer chemical reaction. It has a high epoxy value, a high glass transition temperature, and a low softening point, which matches the subsequent application of this embodiment. Furthermore, the processing of low-softening-point resins is easier. In this embodiment, the concentration range of the epoxy phenolic resin can be set from 15% to 30% to meet various production needs. Of course, those skilled in the art can also select other epoxy phenolic resins according to experimental needs; no specific limitation is made.

[0038] Furthermore, to fully dissolve the parent epoxy phenolic resin and ensure controllable subsequent ring-opening reactions, this embodiment selects 60g-70g of a water-soluble polar solvent, specifically an anhydrous solvent. This is because if the selected polar solvent is insoluble in water, the polarity of the reactants and products might change, leading to a heterogeneous reaction and product precipitation. Conversely, if the solvent contains water, prolonged exposure to water will also cause ring-opening of the epoxy groups. Choosing different solvents ensures that the results of the subsequent epoxy ring-opening reactions are essentially the same, differing only in reactivity. For solvents with lower polarity, the ring-opening reaction may proceed faster, while for solvents with higher polarity, the reaction will be somewhat inhibited due to the action of protonic acid ring-opening reagents, resulting in a relatively slower reaction rate.

[0039] Specifically, in this embodiment, the water-soluble polar solvent can be any one of N,N-dimethylformamide, N,N-diethylformamide, 1,4-butyrolactone, 1,4-dioxane, methanol, ethanol, isopropanol, and acetone, without any specific limitation. Specifically, NPCN-704 epoxy phenolic resin can be dissolved in any of the above-mentioned water-soluble polar solvents according to actual needs to achieve controllability of the overall reaction rate.

[0040] S120: Add 2g to 10g of protic acid ring-opening reagent dropwise to the epoxy phenolic resin solution formed in the previous step S110 in an ice-water bath at a temperature not exceeding 10℃. Then, react at room temperature for 3h to 6h to form a tertiary amine epoxy phenolic resin solution.

[0041] It should be noted that, given the polymer matrix, the first step is the ring-opening reaction of the epoxy groups. The epoxy phenolic resin, as the matrix, inherently possesses phenolic hydroxyl and epoxy groups as active functional groups. The epoxy groups are obtained through the condensation reaction of phenolic hydroxyl groups and epichlorohydrin. The quantity and ratio of phenolic hydroxyl and epoxy groups are inherent in the original epoxy phenolic resin. Of course, the number of epoxy groups on the epoxy phenolic resin can also be controlled through synthesis. Comparing the reactivity of phenolic hydroxyl and epoxy groups, the epoxy group is more reactive than the phenolic hydroxyl group. The reactivity of the epoxy group is mainly manifested in its ease of ring-opening, and its reactivity is characterized by ring-opening under the influence of protic acids.

[0042] Specifically, the ring-opening process in this embodiment should be as anhydrous as possible. The amount used needs to be determined based on the epoxy value of the epoxy phenolic resin. Specifically, the ratio of protic acid ring-opening reagent to epoxy group reactant can be set to 1:1. The number of epoxy groups to be ring-opened can be determined as needed, and the controlled range of the amount of epoxy group ring-opening, calculated as a mass percentage, is 0-100%. Of course, the above specific values ​​can be set according to actual needs, and are not specifically limited thereto.

[0043] Furthermore, in this embodiment, the protic acid ring-opening reagent is a secondary amine ring-opening reagent. Specifically, the ring-opening process involves the hydrogen atom of the secondary amine ring-opening reagent attacking the oxygen atom of the epoxy group, causing the epoxy group to open. The substituents on the nitrogen atom have a significant impact on the speed of epoxy group ring-opening. At the same time, different substituents of the secondary amine are selected according to the requirements for the polarity of the tertiary amine oxidation product. Therefore, in this embodiment, the secondary amine ring-opening reagent is not limited to dimethylamine. In addition to dimethylamine, any one of diethylamine, methyl ethylamine, dipropylamine, and dibutylamine can also be used, without specific limitations.

[0044] Furthermore, in this step, a secondary amine ring-opening agent is used to perform a ring-opening reaction on the epoxy groups on the epoxy phenolic resin formed above. The ring-opening reaction of epoxy groups is an exothermic reaction, and the ring-opening of epoxy groups by secondary amines is no exception. In order to prevent cross-linking reaction of epoxy groups, temperature control in the initial stage of the reaction is very critical. Otherwise, a cross-linking reaction as shown in equation (1) will occur, affecting further applications.

[0045]

[0046] Furthermore, in addition to the selection of the types of protic acid ring-opening reagents mentioned above, the selection of the amount of protic acid ring-opening reagent used in this step is also crucial. By controlling the ratio between the amount of protic acid ring-opening reagent and the amount of epoxy phenolic resin, the quantitative controllability of the reactive groups can be achieved. That is, by controlling the partial or complete ring-opening of the epoxy groups on the epoxy phenolic resin, the residual epoxy groups and the generation of oxidized tertiary amine groups can be quantified.

[0047] Therefore, when adding the secondary amine ring-opening reagent to the above epoxy phenolic resin solution, it is necessary not only to add it dropwise, but also to carry it in an ice-water bath at a temperature not exceeding 10°C. Furthermore, once the secondary amine has been added, the reaction can proceed at room temperature without further artificial heating. The specific reaction time can be set, for example, 3 to 6 hours. The specific ring-opening process is shown in the following formula (2):

[0048]

[0049] In this embodiment, the ring-opening of the epoxy groups in the epoxy phenolic resin does not require high temperatures or artificial heating; it can be achieved essentially at room temperature, thus shortening the reaction time and reducing energy consumption. Furthermore, by controlling the temperature, cross-linking is prevented during the reaction. In other words, this embodiment achieves controllability of the epoxy group ring-opening process in the epoxy phenolic resin through the specific selection of the type and amount of protic acid ring-opening reagent and temperature control.

[0050] S130. 2g to 18g of oxidant is added dropwise to the tertiary amine epoxy phenolic resin solution to carry out an oxidation reaction, forming the oxidized tertiary amine epoxy phenolic resin.

[0051] It should be noted that the process of oxidizing the tertiary amine group to tertiary amine oxide in this embodiment is a highly exothermic process. Although the pH value can be adjusted by using an auxiliary agent or selecting an acidic oxidant to slow down the reaction rate, the exothermic phenomenon is still significant. Therefore, the process of oxidizing the tertiary amine group in this invention consists of the following two steps:

[0052] ① In a water bath at room temperature, add 0.4g to 6g of acidic slowing agent to the tertiary amine epoxy phenolic resin solution to adjust the pH value. Then, add 2g to 18g of oxidant dropwise to carry out the oxidation reaction, controlling the reaction temperature to not exceed 50℃. Alternatively, an acidic oxidant can be directly selected and added dropwise to the tertiary amine epoxy phenolic resin solution to carry out the oxidation reaction, while controlling the reaction temperature to not exceed 50℃.

[0053] In this example, the pH value can be adjusted by adding an acidic slowing agent, or an acidic oxidant can be directly selected, as long as the reaction system is kept in a slightly acidic state. Secondly, the oxidant is added to the reaction system dropwise, and the rate of addition needs to be controlled to control the reaction rate, prevent the unopened epoxy groups from opening, and further prevent the reaction from automatically exothermic and causing the system temperature to rise, thereby causing the polymer crosslinking reaction.

[0054] ② After the oxidant is added, the reaction system is allowed to react naturally in the original water bath for 5 to 7 hours without artificial heating, so as to obtain oxidized tertiary amine epoxy phenolic resin. The specific chemical reaction process is shown in the following formula (3).

[0055]

[0056] It should be noted that in this embodiment, an acidic moderator is added to adjust the pH value of the reaction system, which is applicable to most oxidants, such as hydroxide oxidants. However, if the oxidant used is acidic itself, meaning the reaction system is always in an acidic environment, then an acidic moderator is not required.

[0057] It should be further noted that, in this embodiment, whether before or after the epoxy group ring-opening, the epoxy phenolic resin system remains in a slightly acidic state. Furthermore, since the final modified product is an oxidized tertiary amine group, the oxidant should be an acidic medium oxidant, such as 2,3-dichloro-5,6-dicyanobenzoquinone, hydrogen peroxide, peracetic acid, di(peracetic acid)iodobenzene, oxygen, N-halosuccinimide, tert-butyl hydroperoxide, etc., without specific limitations. Thus, the tertiary amine oxide generated after oxidation has excellent water solubility. Therefore, the epoxy phenolic resin, as the polymer matrix, not only has oil solubility but also water solubility, or even is entirely water-soluble.

[0058] The oxidation rates and results of the aforementioned oxidants on tertiary amines differ, manifested in the differences in the water solubility of the products. Theoretically, the higher the polarity of the oxidant, the smaller its dosage, and the better the water solubility of the product; it also affects the amount of epoxy groups on the modified resin chain. Of course, the amount of epoxy groups consumed is also related to the content of epoxy groups in the original resin.

[0059] It should be further noted that the raw materials for the synthesis of the tertiary amine group in the above process are an acidic oxidant and a tertiary amine group. These are typical Lewis acids and Lewis bases, respectively, exhibiting extremely high reactivity. Therefore, the reaction rate needs to be controlled to prevent explosions. It is important to note that when hydrogen peroxide is chosen as the oxidant, the amount of peroxide must be strictly controlled. This is because hydrogen peroxide is relatively stable under weakly acidic or neutral conditions, but is activated under alkaline conditions, exhibiting strong oxidizing properties that can open the epoxy group ring, and the reaction is quite vigorous. Therefore, strictly speaking, the molar ratio of oxidant to tertiary amine group should ideally be 1:1. That is, the appropriate amount of oxidant is added according to the amount of tertiary amine group to oxidize it and form tertiary amine oxide. Therefore, to control the decomposition of oxidants such as hydrogen peroxide, the pH of the reaction system needs to be adjusted. This requires the addition of an auxiliary agent to slow down the reaction rate. In this embodiment, the auxiliary agent can be any one of saturated fatty polyacids such as citric acid, tartaric acid, lauric acid, and palmitic acid, without specific limitations.

[0060] It should be noted that the amount of the oxidation reaction slowing agent in this example needs to be controlled. On the one hand, if the amount of this agent exceeds the upper limit, the oxidation reaction rate will decrease significantly, which will not only affect the synthesis of the tertiary amine group but also damage the stability of the epoxy group. On the other hand, this agent is a polybasic acid in molecular structure, which poses a threat to the existence of the epoxy group. Controlling the amount of the oxidation reaction slowing agent can slow down the attack of the peroxide on the tertiary amine group while minimizing the ring-opening effect of the polybasic acid on the epoxy group. Therefore, the amount of the oxidation reaction slowing agent ranges from 0.5wt% to 5wt% of the system mass, which is equivalent to 0.4g to 6g of acidic slowing agent.

[0061] Specifically, the mechanism of action of the acidic deceleration aid in this embodiment is illustrated using citric acid as an example, as shown in the following formula (4):

[0062]

[0063] For example, as shown in equation (4), the principle of selecting saturated fatty acid polyacids as acidic decelerating agents for oxidation reactions is as follows: First, polyacids are highly acidic and can form relatively stable hydrogen bonds with oxidants. Second, saturated fatty acids do not contain conjugated systems in their structure, have strong acidity, and the agent itself will not be oxidized.

[0064] The preparation process of the tertiary amine oxide epoxy phenolic resin in this embodiment mainly involves the functional group reaction mechanism and the cationic active center reaction mechanism. Furthermore, the oxidation of the tertiary amine group does not require the addition or use of other solvents; it can be carried out directly in the epoxy group ring-opening generation system. Both steps of the reaction are performed using a water bath or ice-water bath to control automatic heating, with no manual heating process. This ensures that the system temperature does not exceed the temperature threshold for epoxy group ring-opening, guaranteeing the stability of the epoxy group and resulting in low energy consumption. In addition, by controlling the ratio of epoxy groups to tertiary amine oxide groups, the quantitative controllability of the reactive groups is achieved. That is, the residual epoxy groups and the generation of tertiary amine oxide groups can be quantified, thereby adjusting the solubility of the prepared tertiary amine oxide epoxy phenolic resin in different solvents, such as water and organic solvents. Moreover, by controlling the ratio of epoxy groups to tertiary amine oxide groups, the chemical properties of the tertiary amine oxide modified epoxy phenolic resin are no longer reflected in the thermal decomposition of the tertiary amine oxide groups, but also in the ring-opening crosslinking properties of the epoxy groups. These properties cause the polymer backbone to change from a linear structure to a three-dimensional structure, further expanding its application range.

[0065] The preparation method of tertiary amine oxide epoxy phenolic resin will be further illustrated below with reference to several specific embodiments:

[0066] Example 1

[0067] Modified tertiary amine phenolic epoxy resin was prepared using dimethylamine solution (33% concentration) as the ring-opening reagent and hydrogen peroxide (30% concentration) as the oxidant. The amounts of each reactant used in the reaction process are shown in Table 1 below.

[0068] Table 1. Amounts of each reactant used in the preparation of tertiary amine phenolic epoxy resin.

[0069]

[0070] Specifically, the amounts of dimethylamine solution and hydrogen peroxide in Table 1 were divided into six equal portions for experiments to verify the change in epoxy equivalent before and after the reaction. The specific reaction process is as follows: 20g of phenolic epoxy resin 704 and 67g of dioxane were used to prepare polymer solutions. After complete dissolution, dimethylamine solution was added dropwise using a peristaltic pump in an ice-water bath (temperature not exceeding 10℃). The addition time was 3 hours. Then, in the same reaction system, under room temperature water bath conditions, 1.0g of citric acid was added, and after complete dissolution, hydrogen peroxide was slowly added dropwise. During this process, the reaction system automatically heated, maintaining a temperature not exceeding 50℃, and then cooled to room temperature. Timing was started 5 hours after the hydrogen peroxide addition was complete. Stirring was stopped, and the mixture was ready for use.

[0071] It should be noted that when experiments were conducted simultaneously in six equal portions using the amounts of dimethylamine solution and hydrogen peroxide as described in the above formula, the changes in epoxy value deviated somewhat from the theoretical and practical results. For example... Figure 2 As shown, the actual (PV1) and theoretical (SV) values ​​of the epoxy equivalent before and after the resin reaction are basically consistent with the changes in the amount of dimethylamine solution used, but with slight deviations. The deviations are due to differences in concentration. Specifically, a smaller amount of dimethylamine solution results in a lower concentration in the reaction system, thus reducing the effective collision probability within the same reaction time. Conversely, a larger amount of dimethylamine solution results in a higher concentration in the reaction system, increasing the effective collision probability within the same reaction time. Furthermore, the higher water content also contributes to a decrease in the increase in epoxy value.

[0072] Example 2

[0073] Modified tertiary amine phenolic epoxy resin was prepared using dibutylamine as the ring-opening agent and hydrogen peroxide (30% concentration) as the oxidant. The amounts of each reactant used in the reaction process are shown in Table 2 below.

[0074] Table 2. Amounts of each reactant used in the preparation of tertiary amine phenolic epoxy resin.

[0075]

[0076] In Table 2, the amounts of dibutylamine and hydrogen peroxide were divided into six equal portions according to the specified ratio for experiments, verifying the change in epoxy equivalent before and after the reaction. The specific reaction process is described in Example 1 and will not be repeated here.

[0077] In this embodiment, the amounts of dibutylamine and hydrogen peroxide in the formulation were simultaneously tested in six equal portions. The changes in epoxy value also showed some deviation between theory and practice. For example... Figure 3 As shown, comparing the dibutylamine ring-opening reagent (PV2) in this embodiment with the dimethylamine solution ring-opening reagent (PV1) in Example 1, the actual and theoretical values ​​of the modified dibutylamine (PV2) and dimethylamine solution (PV1) generally show the same trend, but with slight deviations. This is because the concentrations of the two ring-opening reagents are different. Furthermore, Figure 3 The results show that dibutylamine (PV2) and dimethylamine solution (PV1) have different effects on epoxy groups. For example, the epoxy equivalent after the reaction using dimethylamine solution as the ring-opening reagent (PV1) is lower than that using dibutylamine as the ring-opening reagent (PV2). There are two reasons for this: First, dibutylamine has greater steric hindrance than dimethylamine, so dibutylamine is not as effective as dimethylamine in modifying resins. Second, dibutylamine is a pure substance, while the dimethylamine solution in Example 1 is an aqueous solution, and water can also cause epoxy groups to open.

[0078] Example 3

[0079] Modified tertiary amine phenolic epoxy resin was prepared using dimethylamine solution (33% concentration) as the ring-opening reagent and peracetic acid (30% concentration) as the oxidant. The amounts of each reactant used in the reaction process are shown in Table 3 below.

[0080] Table 3. Amounts of each reactant used in the preparation of tertiary amine phenolic epoxy resin.

[0081]

[0082] The amounts of dimethylamine solution and peracetic acid in Table 3 were divided into six equal parts according to the ratio for the experiment, which verified the change in epoxy equivalent before and after the reaction. The specific reaction process is described in Example 1 and will not be repeated here.

[0083] The experiment was conducted simultaneously in six equal portions according to the amounts of dimethylamine solution and peracetic acid specified in the formula. The changes in epoxy value showed a certain deviation between theory and practice. Figure 4 As shown, the trends of the modified actual values ​​and theoretical values ​​are basically consistent. Furthermore, the epoxy equivalent after reaction using peracetic acid oxidant (PV3) is lower than that after reaction using hydrogen peroxide oxidant (PV1). For example, combined with... Figure 2 and Figure 3 The changes in Example 3 are basically the same as those in Examples 1 and 2, but there are slight deviations. The changes in epoxy value in Example 3 (PV3) are greater than those in Examples 1 (PV1) and 2 (PV2), and citric acid was not used in the synthesis of Example 3. This is because peracetic acid remains acidic throughout the second reaction step, leading to excessive ring-opening of the epoxy groups.

[0084] Furthermore, combined Figure 5 Curve a represents the parent epoxy phenolic resin in the above embodiments, which has peak values ​​for phenolic hydroxyl and epoxy groups. Curves b / c / d / e represent epoxy phenolic resins at different stages of reaction. It can be seen that as the reaction proceeds, the peak value of the phenolic hydroxyl group remains unchanged, while the peak value of the epoxy group gradually decreases, and the peak value of the tertiary amine oxide gradually increases, ultimately yielding the product, tertiary amine oxide epoxy phenolic resin. Exemplarily, this is combined with... Figure 6 The original epoxy phenolic resin showed good thermal stability before modification, and did not decompose at 160℃. However, the modified tertiary amine oxide group had lower thermal stability, with the highest thermal decomposition intensity measured by DSC and TG at 160℃. Since the tertiary amine oxide group is a very strong water-soluble group, it is this strong water solubility that enables the polymer to achieve water solubility. The epoxy group, on the other hand, has relatively high thermal stability, with the highest thermal decomposition intensity measured by DSC and TG at 220℃.

[0085] As can be seen from the above examples, the epoxy equivalent of the modified tertiary amine epoxy resin gradually decreases with the addition of the secondary amine ring-opening reagent. In other words, the amount of ring-opening reagent can be used to control the amount of epoxy groups in the epoxy resin, that is, to achieve partial or complete ring-opening, so as to obtain tertiary amine epoxy phenolic resins with different ratios of epoxy groups and tertiary amine oxide.

[0086] In a second aspect, the present invention provides an oxidized tertiary amine epoxy phenolic resin, which is prepared by the preparation method described above.

[0087] Specifically, the tertiary amine oxide epoxy phenolic resin includes phenolic hydroxyl, epoxy, and tertiary amine oxide functional groups, and the structural formula of each functional group is shown in formula (5) below. Among them, the tertiary amine oxide group has thermal decomposition properties, while the phenolic hydroxyl and epoxy groups have crosslinking properties.

[0088]

[0089] A third aspect of the present invention provides an application of an oxidized tertiary amine epoxy phenolic resin, wherein the oxidized tertiary amine epoxy phenolic resin described above is applied to a CTP printing plate coating or 3D printing.

[0090] It should be noted that the application of polymers is not only reflected in the polymer chain itself, but more importantly in the substituents of the polymer chain. The tertiary amine oxide-modified epoxy phenolic resin is no exception. As described above, the properties of the substituent functional groups in this embodiment are mainly reflected in the thermal decomposition properties of the tertiary amine oxide group, and the crosslinking properties of the epoxy and phenolic hydroxyl groups.

[0091] Specifically, the tertiary amine oxide group has low thermal stability; its thermal decomposition intensity, as tested by DSC and TG, is highest at 160℃. Figure 6 and Figure 7 As shown. The tertiary amine oxide group is a highly water-soluble group, and it is this strong water solubility that enables the polymer to achieve water solubility. However, when the polymer is heated to around 160°C, the tertiary amine oxide group decomposes, meaning the water-soluble resin loses its hydrophilicity and becomes insoluble in water. Utilizing this property, this resin can be used in thermosensitive phase change materials where affinity changes. Since the thermal decomposition properties of tertiary amine oxide have been reported in existing literature, they will not be elaborated upon here.

[0092] Secondly, the epoxy groups have relatively high thermal stability; according to DSC and TG tests, the highest thermal decomposition intensity is 220℃, as shown in the attached figure. Figure 6 and Figure 7As shown. The ring-opening reactivity of epoxy groups is very high, and most of the groups that promote epoxy ring-opening are strongly acidic or basic. Therefore, crosslinking agents or initiators with epoxy ring-opening functional groups can be used to react with the original resin, thereby changing the resin from a linear structure to a network structure, or even a three-dimensional structure. Crosslinking agents include dibasic organic acids, dibasic organic bases, and latent diisocyanates; initiators include acidic quaternary ammonium salts (such as sulfates, hydrochlorides, and perchlorates) and iodonium salts (such as diphenyliodonium salt and xylyliodonium salt), thereby initiating the cationic polymerization of epoxy groups.

[0093] Furthermore, the phenolic hydroxyl group is a highly reactive functional group. It can react with bases and also with even more reactive functional groups, thus causing cross-linking. Latent diisocyanates (such as methyl ethyl ketone oxime diisocyanate) can be used for these more reactive functional groups.

[0094] The following examples will further illustrate the crosslinking properties of phenolic hydroxyl groups and epoxy groups in tertiary amine oxide epoxy phenolic resins:

[0095] Example 4

[0096] The tertiary amine epoxy phenolic resin described above was prepared into a 10wt% solution with anhydrous ethanol, and then an appropriate amount of the diisocyanate-butanone oxime addition product was added sequentially. After stirring evenly, an appropriate amount of the solution was centrifuged and coated onto the surface of an aluminum plate substrate with a sand-like texture, and dried at 100℃ to form a dry film of resin.

[0097] An aluminum plate partially coated with a dry film of epoxy phenolic resin modified with tertiary amine oxide was placed on a temperature-controlled plate and heated to 120°C for 10 minutes. Then, the aluminum plate was removed and allowed to cool naturally to room temperature. Finally, the contact angles of the heated and unheated aluminum plates were tested with water, yielding two drastically different results: the contact angle of the heated aluminum plate was 110°, while the contact angle of the unheated aluminum plate was 0°. This is because the heated aluminum plate was treated at 120°C, at which temperature the stability of the tertiary amine oxide and epoxy groups remained unaffected. The hydroxyl groups undergo crosslinking, and the specific crosslinking mechanism is shown in equation (6).

[0098]

[0099] Example 5

[0100] The epoxy phenolic resin modified with tertiary amine oxide was prepared into a 10wt% solution with anhydrous ethanol, and then an appropriate amount of imidazole perchlorate was added. After stirring evenly, an appropriate amount of the solution was centrifuged and coated onto the surface of an aluminum plate substrate with a sandy texture, and dried at 100℃ to form a dry film of resin.

[0101] An aluminum plate partially coated with a dry film of tertiary amine oxide epoxy phenolic resin was placed on a temperature-controlled plate and heated to 180°C, then held at that temperature for 10 minutes. The plate was then removed and allowed to cool naturally to room temperature. Finally, the contact angles of the heated and unheated aluminum plates were tested with water, yielding two drastically different results, such as... Figure 8 As shown, the contact angle of the heated aluminum plate is 142°~160°, while the contact angle of the unheated aluminum plate is 0°. The reason is that the heated aluminum plate is treated at 200°C, which not only decomposes the tertiary amine group, but also causes the cations generated after the decomposition of imidazole perchlorate to open the ring crosslink of the epoxy group. The specific ring-opening mechanism of the epoxy group cation is shown in the following formula (7).

[0102]

[0103] Example 6

[0104] Based on Examples 4 and 5 above, the crosslinking principles of phenolic hydroxyl groups and epoxy groups are integrated to form the crosslinking system of Example 6. This two-in-one crosslinking system can be used in the imaging system of thermal CTP printing plates. Under the action of an 830nm thermal dye and infrared laser, the thermal crosslinking processes of Examples 4 and 5 are simultaneously achieved on the printing plate, and finally, the image with staggered colors is formed through development.

[0105] Specifically, the tertiary amine oxide-modified epoxy phenolic resin in this embodiment is a functional polymer based on three functional groups, capable of both photocuring and thermocuring. The chemical properties of the tertiary amine oxide-modified epoxy phenolic resin are no longer limited to the thermal decomposition of the tertiary amine oxide groups, but also include the ring-opening crosslinking properties of the epoxy groups. These properties cause the polymer backbone to change from a linear structure to a three-dimensional structure. Furthermore, because epoxy phenolic resin can ring-open an appropriate amount of epoxy groups, the tertiary amine oxide-modified epoxy phenolic resin achieves water solubility. For example, when this material is used as a film-forming material for CTP printing plate coatings, the presence of epoxy groups facilitates perchlorate-induced thermo-cationic polymerization. Therefore, by selecting an appropriate epoxy group ratio, the modified epoxy phenolic resin undergoes cationic thermo-crosslinking under suitable conditions. In other words, the application of tertiary amine oxide-modified epoxy phenolic resin in the direct preparation of CTP printing plates is based on the cationic polymerization-type thermo-crosslinking of the modified resin by perchlorate, which is sensitive to infrared lasers.

[0106] The coating achieved in this embodiment is green and environmentally friendly, overcoming the limitations of linear polymer structures. Its solvent-resistant bulk structure gives the printing plate image excellent solvent resistance, improving the printing plate's durability. Furthermore, the imaging process no longer uses strong alkaline solutions for development, avoiding environmental pollution from the developer solution.

[0107] Furthermore, when amine oxide-modified epoxy phenolic resin is used as a consumable for 3D printing, the presence of epoxy groups facilitates the thermo-cationic polymerization initiated by iodonium salts. Therefore, modified epoxy phenolic resins with appropriate epoxy group ratios undergo cationic thermo-crosslinking under suitable conditions. In other words, the application of amine oxide-modified epoxy phenolic resin in 3D printing is based on the cationic polymerization-type photocrosslinking of the modified resin by iodonium salts (diphenyliodonium salt, xylyliodonium salt, etc.), which is UV-sensitive, so that the 3D products of this embodiment possess both environmentally friendly and robust physical properties.

[0108] The preparation method of tertiary amine oxide epoxy phenolic resin provided by this invention has the following advantages compared with the prior art: First, the epoxy groups on the epoxy phenolic resin can be flexibly ring-opened, and the ring-opening process does not require heating, shortening the reaction time and reducing energy consumption. Second, the ring-opening reagent used in the preparation method of this invention is no longer limited to dimethylamine; other secondary amine ring-opening reagents can be used. Third, the formation process of tertiary amine oxide is controllable and does not require heating, resulting in low energy consumption. Fourth, by controlling the ratio of epoxy groups to tertiary amine oxide, the solubility of tertiary amine oxide epoxy phenolic resin in different solvents is adjusted, while simultaneously exhibiting both hydrophilic and lipophilic properties, broadening the solubility range of the product and further expanding its application scope. Secondly, the oxidized tertiary amine epoxy phenolic resin provided by this invention possesses oxidized tertiary amine, epoxy, and phenolic hydroxyl groups, making it a functional polymer based on these three functional groups. It can be cured both photopolymerically and thermopolymerically, and can be applied to CTP printing plate coatings, resulting in a green and environmentally friendly coating that overcomes the limitations of linear polymer structures. Its solvent-resistant bulk structure gives the printing plate image excellent solvent resistance, improving the printing plate's durability. Furthermore, the imaging process no longer requires strong alkaline developing solutions, avoiding environmental pollution from the developing solution. Additionally, it can be applied to 3D printing, giving 3D products both environmentally friendly and robust physical properties.

[0109] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A process for the preparation of an oxidized tertiary amine epoxy novolac resin characterized by, The specific preparation steps include: Take 15g~25g of the preset epoxy phenolic resin and dissolve it in a polar solvent dissolved in water to form an epoxy phenolic resin solution; the preset epoxy phenolic resin has a softening point range of 85℃~95℃, a glass transition temperature not lower than 90℃, and an epoxy value not lower than 220 g / eq.; the polar solvent dissolved in water is a water-free solvent; 2g~10g of any one of dimethylamine ring-opening reagent, diethylamine ring-opening reagent, methylethylamine ring-opening reagent, dipropylamine ring-opening reagent, and dibutylamine ring-opening reagent is added dropwise to the epoxy phenolic resin solution in an ice water bath with a temperature not higher than 10℃, and then the reaction is carried out at room temperature for 3h~6h to form a tertiary amine group epoxy phenolic resin solution; 2g~18g of an oxidizing agent is added dropwise to the tertiary amine group epoxy phenolic resin solution to carry out an oxidation reaction to form the oxidized tertiary amine epoxy phenolic resin, including: In a room temperature water bath, 2g~18g of an oxidizing agent is added dropwise to the tertiary amine group epoxy phenolic resin solution to carry out an oxidation reaction, with the control that the reaction temperature is not higher than 50℃; After the addition of the oxidizing agent is completed, the reaction is carried out for 5h~7h to obtain the oxidized tertiary amine epoxy phenolic resin, which includes phenolic hydroxyl groups, epoxy groups, and oxidized tertiary amine groups.

2. The production method according to claim 1, characterized by, The polar solvent dissolved in water is any one of N,N-dimethylformamide, N,N-diethylformamide, 1,4-butyrolactone, 1,4-dioxane, methanol, ethanol, isopropanol, and acetone.

3. The preparation method according to claim 1, characterized in that, Before the step of adding 2g~18g of an oxidizing agent dropwise to the tertiary amine group epoxy phenolic resin solution in a room temperature water bath to carry out an oxidation reaction with the control that the reaction temperature is not higher than 50℃, the step further includes: 0.4g~6g of an acidic retarding aid is added to the tertiary amine group epoxy phenolic resin solution to adjust the pH value of the solution.

4. The production method according to claim 3, characterized by, The oxidizing agent includes any one of 2,3-dichloro-5,6-dicyano-benzoquinone, hydrogen peroxide, di(peroxyacetic acid)iodobenzene, oxygen, N-halosuccinimide, and tert-butyl hydroperoxide; and / or, The acidic retarding aid includes any one of citric acid, tartaric acid, lauric acid, and palmetto acid.

5. An oxidized tertiary amine epoxy novolac resin characterized in that, The oxidized tertiary amine epoxy phenolic resin is prepared by the method described in any one of claims 1 to 4.

6. Use of an oxidized tertiary amine epoxy novolac resin characterized in that, The oxidized tertiary amine epoxy phenolic resin described in claim 5 is applied to a printing CTP plate coating or 3D printing.

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