阅读说明：本技术 一种环氧树脂乳液的绿色制备工艺 (Green preparation process of epoxy resin emulsion ) 是由 聂朝阳 林培雄 于 2020-12-18 设计创作，主要内容包括：本申请涉及乳液制备工艺领域,具体公开一种环氧树脂乳液的绿色制备工艺,包括以下步骤：S1：将质量份数为35-65份的液体环氧树脂、0.2-1份的反应型自乳化剂和2-10份的醇醚溶剂进行混合,并低速搅拌30-40min,得油相溶液；S2：控制搅拌速度为1000-1200r/min,将质量份数为35-60份的去离子水分多次添加到油相溶液中,添加完成后继续搅拌1-2h,得混合液；S3：将混合液静置,过滤后出料,得环氧树脂乳液；所述反应型自乳化剂为同时含有氨基和环氧基的植物类可降解反应型自乳化剂。本申请通过使用新型的植物类可降解反应型自乳化剂,可实现更加绿色环保的生产工艺。(The application relates to the field of emulsion preparation processes, and particularly discloses an environment-friendly preparation process of an epoxy resin emulsion, which comprises the following steps: s1: mixing 35-65 parts by mass of liquid epoxy resin, 0.2-1 part by mass of reactive self-emulsifying agent and 2-10 parts by mass of alcohol ether solvent, and stirring at low speed for 30-40min to obtain an oil phase solution; s2: controlling the stirring speed to be 1000-; s3: standing the mixed solution, filtering and discharging to obtain epoxy resin emulsion; the reactive self-emulsifying agent is a plant degradable reactive self-emulsifying agent containing both amino and epoxy groups. The application can realize more green and environment-friendly production process by using the novel plant degradable reactive self-emulsifying agent.)

1. A green preparation process of epoxy resin emulsion is characterized by comprising the following steps: the method comprises the following steps:

s1: mixing 35-65 parts by mass of liquid epoxy resin, 0.2-1 part by mass of reactive self-emulsifying agent and 2-10 parts by mass of alcohol ether solvent, and stirring at low speed for 30-40min to obtain an oil phase solution;

s2: controlling the stirring speed to be 1000-;

s3: standing the mixed solution, filtering and discharging to obtain epoxy resin emulsion;

the reactive self-emulsifying agent is a plant degradable reactive self-emulsifying agent containing both amino and epoxy groups.

2. The green preparation process of the epoxy resin emulsion as claimed in claim 1, wherein: the plant degradable reactive self-emulsifier is a nonionic reactive self-emulsifier synthesized based on cardanol polyoxyethylene ether.

3. The green preparation process of the epoxy resin emulsion as claimed in claim 2, characterized in that: the polymerization degree of the cardanol polyoxyethylene ether is 14-18.

4. The green preparation process of the epoxy resin emulsion as claimed in claim 1, wherein: the alcohol ether solvent is propylene glycol methyl ether.

5. The green preparation process of the epoxy resin emulsion as claimed in claim 1, wherein: the liquid epoxy resin is formed by mixing 25-35 parts by mass of epoxy resin A and 10-30 parts by mass of epoxy resin B, wherein the epoxy value of the epoxy resin A is 0.5-0.55, and the epoxy value of the epoxy resin B is 0.4-0.45.

6. The green preparation process of the epoxy resin emulsion as claimed in claim 1, wherein: in step S2, 25-40 parts by mass of deionized water is added into the oil phase solution for 3-4 times, the addition is controlled to be completed within 1-2 hours, the rotation speed of 1000-1200r/min is kept for continuous stirring until the viscosity of the mixed solution is reduced, the remaining 10-20 parts of deionized water are added for 2-3 times, and the addition is controlled to be completed within 0.5-1 hour.

7. The green preparation process of the epoxy resin emulsion as claimed in claim 1, wherein: in step S3, before the mixed solution is allowed to stand, the mixed solution is stirred at a low speed of 500-550r/min for 30-35 min.

8. The green preparation process of the epoxy resin emulsion as claimed in claim 1, wherein: in step S1, the stirring speed during low-speed stirring is 450-500 r/min.

Technical Field

The application relates to the technical field of emulsion preparation processes, in particular to a green preparation process of epoxy resin emulsion.

Background

The epoxy resin is a high molecular polymer and is a generic name of a polymer containing more than two epoxy groups in a molecule. Due to the chemical activity of the epoxy group, a plurality of compounds containing active hydrogen can be used for ring opening, curing and crosslinking to generate a network structure, so that the epoxy resin and the curing agent can be prepared into epoxy resin glue and can be widely used as a coating and an adhesive.

The epoxy resin emulsion is an emulsion of epoxy resin in water under the action of emulsifier. The general preparation process is that solid epoxy resin is ground into micron-sized epoxy resin powder in advance, then the epoxy resin and emulsifier are mixed, heated to a proper temperature, and water is added under stirring to form emulsion.

In the existing process, heating is needed in the emulsification process, and the energy consumption is high in the preparation process.

Disclosure of Invention

In order to reduce energy consumption in the preparation process of the epoxy resin emulsion, the application provides a green preparation process of the epoxy resin emulsion.

A green preparation process of epoxy resin emulsion comprises the following steps:

s1: mixing 35-65 parts by mass of liquid epoxy resin, 0.2-1 part by mass of reactive self-emulsifying agent and 2-10 parts by mass of alcohol ether solvent, and stirring at low speed for 30-40min to obtain an oil phase solution;

s2: controlling the stirring speed to be 1000-;

s3: standing the mixed solution, filtering and discharging to obtain epoxy resin emulsion;

the reactive self-emulsifying agent is a plant degradable reactive self-emulsifying agent containing both amino and epoxy groups.

By adopting the technical scheme, the plant degradable reactive self-emulsifying agent containing both amino and epoxy is adopted, and the self amino and epoxy can react while the emulsifying agent performs an emulsifying effect, so that a cross-linked surface active layer is formed on the periphery of the epoxy resin colloidal particles, the emulsifying capacity of the surface active layer is far stronger than that of a common emulsifying agent, and the epoxy resin can be fully emulsified in water to form the colloidal particles without heating and activating.

In step S1, the epoxy resin and the emulsifier are mixed in the alcohol ether, and the alcohol ether can be used as a solvent for the epoxy resin, which can reduce the viscosity of the epoxy resin and is beneficial to the subsequent emulsification step. The alcohol ether can be mutually dissolved with water, so that the formation of colloidal particles is not influenced.

In step S2, water is gradually added to the oil phase solution, the oil phase is fully dispersed in the water phase under high-speed stirring, the epoxy resin forms fine colloidal particles, in this process, under the dual action of the oil phase and the water phase, the emulsifier forms a dense surface active layer on the surface of the epoxy resin, the high-density amino group and epoxy group of the emulsifier in the surface active layer can fully contact, the reaction between the amino group and the epoxy group is possible from the chemical kinetics level, and thus the emulsifier molecules in the surface active layer are crosslinked. And because the emulsifier contains the same structure as the epoxy resin, the emulsifier can play an anchoring role according to the principle of similar intermiscibility, so that the emulsifier has stronger binding capacity with the oil phase. Therefore, the emulsifier has strong emulsifying capacity and can achieve good emulsifying effect without heating. And under the excellent emulsification effect, the epoxy resin can be emulsified into colloidal particles with smaller particle size, so that the water resistance, toughness, hardness and glossiness of the cured epoxy resin can be improved.

After emulsification is completed, the epoxy resin emulsion can be prepared by standing in the step S3 and discharging after filtration.

Preferably, the plant degradable reactive self-emulsifier is a nonionic reactive self-emulsifier synthesized based on cardanol polyoxyethylene ether.

By adopting the technical scheme, the cardanol is a natural component extracted from cashew nut shell oil, the natural component has the advantages of environmental protection and no pollution, and the nonionic reactive self-emulsifying agent synthesized based on cardanol polyoxyethylene ether can be biodegraded, so that waste pollution generated in the production and preparation process can be prevented, and the process is more green and environment-friendly.

Preferably, the polymerization degree of the cardanol polyoxyethylene ether is 14-18.

By adopting the technical scheme, the emulsifier prepared from the cardanol with the polymerization degree can have better emulsifying capacity, can be conveniently crosslinked while ensuring better emulsifying capacity, and can be used for preparing colloidal particles with smaller particle size.

Preferably, the alcohol ether solvent is propylene glycol methyl ether.

By adopting the technical scheme, the propylene glycol methyl ether has low toxicity and no pungent smell, and belongs to low-toxicity alcohol ether substances. The environmental impact of the waste material is reduced while ensuring excellent solubility and viscosity reduction capability for the epoxy resin.

Preferably, the liquid epoxy resin is prepared by mixing 25-35 parts by mass of epoxy resin A and 10-30 parts by mass of epoxy resin B, wherein the epoxy value of the epoxy resin A is 0.5-0.55, and the epoxy value of the epoxy resin B is 0.4-0.45.

By adopting the technical scheme, the epoxy resins with different epoxy values are mixed, so that the emulsified colloidal particles have smaller particle size, the emulsifying effect can be further improved under the matching of the reactive self-emulsifying agent, and the epoxy resin emulsion has better water resistance after being cured.

Preferably, in step S2, 25 to 40 parts by weight of deionized water is added to the oil phase solution 3 to 4 times, the addition is controlled to be completed within 1 to 2 hours, the stirring is continued at a rotation speed of 1200r/min for 1000 and 1200r/min until the viscosity of the mixed solution decreases, the remaining 10 to 20 parts by weight of deionized water is added for 2 to 3 times, and the addition is controlled to be completed within 0.5 to 1 hour.

By adopting the technical scheme, the deionized water is added in two stages, and each stage is added for multiple times, so that excessive aggregation of colloidal particles can be prevented, the emulsified colloidal particles have smaller particle size, and the emulsifying effect of the epoxy resin in water is improved. In the adding process of the first stage, the water phase enters the oil phase, water-in-oil is adopted in the first stage, water beads are gradually formed in the oil phase after stirring under the action of the emulsifier, and after sufficient water is added, the stirring is continuously carried out, the water beads are gradually combined, finally phase change is realized, an oil-in-water structure is formed, the viscosity is suddenly reduced, and the emulsion is preliminarily formed. After the phase change is finished, the second stage of water addition is carried out, and the process is mainly to adjust the dispersion degree of the colloidal particles in the water so that the colloidal particles with smaller particle size can be formed under stirring.

Preferably, in step S3, before the mixed solution is allowed to stand, the mixed solution is first stirred at a low speed of 500-550r/min for 30-35 min.

Through adopting above-mentioned technical scheme, after accomplishing the emulsification, stirring at low speed, can detach the bubble that produces in the high-speed stirring emulsification process, reach the purpose of defoaming, make the emulsion more even, prevent that the bubble from producing the influence to it in emulsion solidification process.

Preferably, in step S1, the stirring speed during low-speed stirring is 450-500 r/min.

By adopting the technical scheme, the epoxy resin and the emulsifier can be better dispersed in the alcohol ether solvent at the stirring speed, partial crosslinking of the emulsion is facilitated at the initial stage at the stirring speed, favorable conditions are provided for subsequent emulsification, and the preparation of colloidal particles with smaller particle sizes is facilitated.

In summary, the present application includes at least one of the following beneficial technical effects:

1. according to the preparation method, the plant degradable reactive self-emulsifying agent containing the amino and the epoxy groups is used, the high-performance emulsifying capacity is utilized, the epoxy resin can be emulsified without heating, the high-performance emulsifying agent can be prepared by controlling various process parameters in the emulsifying process and the dosage ratio among the components, and the preparation process is more environment-friendly.

2. The application discloses plant type degradable reactive self-emulsifying agent specifically chooses non-ionic reactive self-emulsifying agent based on cardanol polyoxyethylene ether synthesis for use, and this kind of emulsifier can carry out biodegradable, reduces the waste material pollution that produces in the preparation process, makes preparation technology green more. The application also discloses the preferable polymerization degree of the cardanol polyoxyethylene ether, so that colloidal particles with smaller particle sizes are prepared.

3. According to the process, in the process of adding water into the oil phase solution, the prepared emulsion has better performance by adding water for multiple times in stages, and the prepared colloidal particles have smaller particle size.

4. The application also discloses that propylene glycol methyl ether is specifically selected as the alcohol ether solvent, and the liquid epoxy resin is a mixture of two epoxy resins with different epoxy values, so that the performance of the prepared emulsion is further improved.

5. After the emulsion is emulsified, the mixed solution is stirred at a low speed, so that bubbles in the mixed solution are removed, and the quality of the prepared emulsion is improved.

Detailed Description

Preparation example

Preparation of the emulsifier:

s1: adding peroxyacetic acid with the concentration of 30% into cardanol polyoxyethylene ether, stirring for 1.5h at room temperature, and then separating and purifying by using neutral lead oxide as an adsorbent and tetrahydrofuran as an eluent to obtain the epoxidized cardanol polyoxyethylene ether.

S2: mixing epoxidized cardanol polyoxyethylene ether and thionyl chloride with equal amount of substances, mixing and stirring the mixture for 1 hour by taking pyridine as a catalyst, adding phthalimide potassium salt with equal amount of substances, mixing and stirring the mixture for 4 hours, filtering the mixture, and washing a solid intermediate product.

S3: and adding the solid intermediate product into a hydrochloric acid alcohol solution with the concentration of 35%, stirring for 15h, filtering under reduced pressure, and washing to obtain the nonionic reactive self-emulsifying agent synthesized based on cardanol polyoxyethylene ether.

Examples

Example 1: a green preparation process of epoxy resin emulsion,

the process comprises the following steps:

s1: adding 35kg of liquid epoxy resin, 0.2kg of reactive self-emulsifier and 2kg of propylene glycol methyl ether into a dispersion cylinder, and stirring for 30min at the stirring speed of 400r/min to obtain an oil phase solution;

s2: adjusting the stirring speed to 1000r/min, adding 35kg of deionized water into the dispersion cylinder five times in 1h, and stirring for 1h after the addition is finished to obtain a mixed solution;

s3: and standing the mixed solution, filtering and discharging to obtain the epoxy resin emulsion.

The liquid epoxy resin in step S1 is specifically E-44 epoxy resin (epoxy value is 0.44); the reactive self-emulsifying agent is a nonionic reactive self-emulsifying agent which is synthesized based on cardanol polyoxyethylene ether and has amino and epoxy groups, wherein cardanol polyoxyethylene ether with the polymerization degree of 12 is selected, and the cardanol polyoxyethylene ether is prepared through the steps of the preparation example.

Example 2: a green preparation process of epoxy resin emulsion,

the difference from example 1 is that the amounts of the components and the process parameters are different, as shown in table 1 below.

Example 3: a green preparation process of epoxy resin emulsion,

the difference from example 1 is that cardanol polyoxyethylene ether for preparing a nonionic reactive self-emulsifier has a degree of polymerization of 14. The amounts of the components and the process parameters are shown in table 1 below.

Example 4: a green preparation process of epoxy resin emulsion,

the difference from example 1 is that cardanol polyoxyethylene ether for preparing a nonionic reactive self-emulsifier has a degree of polymerization of 18. The amounts of the components and the process parameters are shown in table 1 below.

Examples 5 to 6: a green preparation process of epoxy resin emulsion,

the difference from example 1 is that the liquid epoxy resin used is a mixture of E-44 epoxy resin (with an epoxy value of 0.44) and 128 epoxy resin (with an epoxy value of 0.53), the amounts of both resins and the remaining process parameters being as indicated in Table 1 below.

Example 7: a green preparation process of epoxy resin emulsion,

the difference from example 1 is that deionized water was added in two portions in step S2.

The S2 concrete steps are: controlling the stirring speed to be 1000r/min, firstly adding 25kg of deionized water into the dispersion tank for 3 times, controlling the adding for 1h, keeping the rotating speed of 1000r/min for continuous stirring until the viscosity of the mixed solution is reduced, then adding 10kg of deionized water into the dispersion tank for 2 times, controlling the adding for 0.5 h, and stirring for 1h after the adding is finished to obtain the mixed solution.

The rest of the procedure was the same as in example 1. The amounts of the components used, the remaining process parameters, are shown in table 1 below.

Example 8: a green preparation process of epoxy resin emulsion,

the difference from example 1 is that deionized water was added in two portions in step S2.

The S2 concrete steps are: controlling the stirring speed to be 1000r/min, firstly adding 40kg of deionized water into the dispersion tank for 4 times, controlling the adding for 2 hours, keeping the rotating speed of 1000r/min for continuous stirring until the viscosity of the mixed solution is reduced, then adding 20kg of deionized water into the dispersion tank for 3 times, controlling the adding for 1 hour, and stirring for 1 hour after the adding is finished to obtain the mixed solution.

The rest of the procedure was the same as in example 1. The amounts of the components used, the remaining process parameters, are shown in table 1 below.

Examples 9 to 10: a green preparation process of epoxy resin emulsion,

the difference from example 1 is that the stirring speed in step S1 is different, and the specific parameters are shown in table 1 below.

Example 11: a green preparation process of epoxy resin emulsion,

the difference from example 1 is that the mixed solution is stirred at a low speed for a while before the mixed solution is allowed to stand in step S3.

The S3 concrete steps are: stirring the mixed solution at a low speed of 500r/min for 30min, standing the mixed solution, filtering and discharging to obtain the epoxy resin emulsion.

The rest of the procedure was the same as in example 1. The amounts of the components used, the remaining process parameters, are shown in table 1 below.

Example 12: a green preparation process of epoxy resin emulsion,

the difference from example 1 is that the mixed solution is stirred at a low speed for a while before the mixed solution is allowed to stand in step S3.

The S3 concrete steps are: and stirring the mixed solution at a low speed of 550r/min for 35min, standing the mixed solution, filtering and discharging to obtain the epoxy resin emulsion.

The rest of the procedure was the same as in example 1. The amounts of the components used, the remaining process parameters, are shown in table 1 below.

Table 1: EXAMPLES 1-12 amounts of Components and parameters

Comparative example

Comparative example 1: a preparation process of an epoxy resin emulsion,

the process comprises the following steps:

s1: adding 35kg of liquid epoxy resin, 0.2kg of emulsifier and 2kg of propylene glycol methyl ether into a dispersion cylinder, and stirring for 30min at the stirring speed of 400r/min to obtain an oil phase solution;

s2: adjusting the stirring speed to 1000r/min, heating the dispersion tank to 80 ℃, adding 35kg of deionized water into the dispersion tank five times in 1h, and stirring for 1h after the addition is finished to obtain a mixed solution;

s3: and cooling, standing the mixed solution, filtering and discharging to obtain the epoxy resin emulsion.

The liquid epoxy resin in step S1 is specifically E-44 epoxy resin (epoxy value is 0.44); the emulsifier is sorbitan fatty acid ester.

Comparative example 2: a preparation process of an epoxy resin emulsion,

the difference from comparative example 1 is that the emulsifier is sorbitan polyoxyethylene. The specific amounts and process parameters are shown in table 2 below.

Comparative example 3: a preparation process of an epoxy resin emulsion,

the process comprises the following steps:

s1: adding 35kg of liquid epoxy resin, 0.2kg of reactive self-emulsifier and 2kg of propylene glycol methyl ether into a dispersion cylinder, and stirring for 30min at the stirring speed of 400r/min to obtain an oil phase solution;

s2: adjusting the stirring speed to 1000r/min, heating the dispersion tank to 80 ℃, adding 35kg of deionized water into the dispersion tank five times in 1h, and stirring for 1h after the addition is finished to obtain a mixed solution;

s3: and cooling, standing the mixed solution, filtering and discharging to obtain the epoxy resin emulsion.

The liquid epoxy resin in step S1 is specifically E-44 epoxy resin (epoxy value is 0.44); the reactive self-emulsifying agent is a nonionic reactive self-emulsifying agent which is synthesized based on cardanol polyoxyethylene ether and has amino and epoxy groups, wherein cardanol polyoxyethylene ether with the polymerization degree of 12 is selected, and the cardanol polyoxyethylene ether is prepared through the steps of the preparation example.

Comparative example 4: a preparation process of an epoxy resin emulsion,

the difference from comparative example 3 is that the antipyretic temperature of the dispersion cylinder in S2 is different. The specific amounts of the components and the process parameters are shown in table 2 below.

Comparative examples 5 to 6: a preparation process of an epoxy resin emulsion,

the difference from example 1 is that the stirring speed in step S2 is different. The specific amounts of the components and the process parameters are shown in table 2 below.

Table 2: comparative examples 1-6 amounts of the respective Components and Process parameters

Performance test

Test one: colloidal particle size detection test

The test principle is as follows: the colloidal particles were observed by an optical microscope and the particle size was calculated from the magnification.

Test subjects: examples 1-12 and comparative examples 1-6.

The test method comprises the following steps: according to the method for measuring the particle size of item 5.9 described in the national Standard of the people's republic of China GB/T11175-2002, the particle number of each sample is measured to be 60, the average particle size (mum) is calculated, the calculation result retains one decimal number, and the test results are shown in the following table 3.

Table 3: average particle diameters of examples 1 to 12 and comparative examples 1 to 6

And (2) test II: standing delamination test principle: and (3) standing each test sample, recording the time for each test sample to be layered, and comparing to judge the stability of each test sample.

Test subjects: examples 1 to 12, comparative examples 1 to 6.

The test method comprises the following steps: 1L of each of the newly prepared emulsions of examples 1 to 12 and comparative examples 1 to 6 was taken out and stored in the same transparent glass container at room temperature, and the emulsions were observed every other day until the emulsions were layered, and the number of days on which the emulsions of each of examples and comparative examples were layered was recorded, and the test results are shown in Table 4 below.

Table 4: days on which standing delamination occurred in examples 1 to 12 and comparative examples 1 to 6

Experiment three: water resistance test principle: preparing epoxy resin glue from the emulsion and a curing agent, coating the epoxy resin glue on a test plate, fully curing the epoxy resin glue to obtain a sample, soaking the sample in water, and comparing the time for which the paint film is damaged, so that the water resistance of the paint film formed by curing different emulsions can be compared.

Test subjects: epoxy resin emulsions prepared in examples 1 to 12 and comparative examples 1 to 6 were mixed with a BS-782 type curing agent to prepare epoxy resin adhesives, which were respectively coated on the surfaces of 15cm × 15cm steel plates and sufficiently cured. 3 samples were prepared for each of examples and comparative examples, respectively, and the samples of each group corresponding to examples 1 to 12 and comparative examples 1 to 6 were labeled test group 1 to 12 and control group 1 to 6 in this order.

The test method comprises the following steps: adding deionized water into a glass water tank, keeping the water temperature at 25 +/-2 ℃, soaking 2/3 samples of the length of each test group and the control group into distilled water, and taking out at intervals to observe the paint film state on the surface of each sample. If the paint films of at least two samples in the three samples have the phenomena of light loss, color change, air bubbles, wrinkling or falling off, the paint film group is judged to have failed, the number of days for which the paint film of each group of samples fails is recorded, and the test results are shown in the following table 5.

Table 5: days of failure of the paint films of test groups 1-12 and control groups 1-6

	Test group 1	Test group 2	Test group 3	Test group 4	Test group 5	Test group 6
							Number of days of failure of paint film	190	195	234	236	215	214
	Test group 7	Test group 8	Test group 9	Test group 10	Test group 11	Test group 12
							Number of days of failure of paint film	252	253	208	206	212	208
	Control group 1	Control group 2	Control group 3	Control group 4	Control group 5	Control group 6
							Number of days of failure of paint film	104	93	193	197	176	164

The results of test one, test two and test three were analyzed in combination:

comparing the data of examples/test groups 1-2 and comparative examples/control groups 1-2 in tables 3, 4 and 5, it can be seen that the average particle size of examples/test groups 1-2 is smaller than that of comparative examples/control groups 1-2, and the number of days for which delamination occurred and the number of days for which the paint film failed are much larger than those of comparative examples/control groups 1-2, which indicates that the epoxy resin emulsion prepared by examples 1-2 has better dispersibility, is less likely to delaminate, and has better water resistance after curing. Thus, the plant degradable reactive self-emulsifying agent containing both amino and epoxy groups is used, and the epoxy resin emulsion with higher performance can be prepared by matching with a proper process under the action of high-efficiency emulsifying capacity.

Comparing the data of examples/test groups 1-2 and comparative examples/control groups 3-4 in tables 3, 4 and 5, it can be seen that the values of examples/test groups 1-2 and comparative examples/control groups 3-4 are all similar. This indicates that the emulsification effect of the epoxy resin emulsion obtained without heating by using the plant-based degradable reactive self-emulsifier containing both amino group and epoxy group under the same conditions as the rest of the process is similar to that of the epoxy resin emulsion obtained with heating. Therefore, the emulsifier can achieve sufficient and good emulsifying effect at normal temperature without heating, so that the preparation process is more energy-saving and environment-friendly.

Comparing the data of examples/test groups 1-2 and comparative examples/control groups 5-6 in tables 3, 4 and 5, it can be seen that the average particle size of examples/test groups 1-2 is smaller than that of comparative examples/control groups 5-6, and the number of days in which delamination occurred and the number of days in which the paint film failed are larger than that of comparative examples/control groups 5-6. This shows that the rotation speed used in the emulsification process of examples 1-2 is in a more preferable range, because when the rotation speed is too low, the epoxy resin cannot be sufficiently dispersed, and when the rotation speed is too high, the emulsifier is difficult to be stably bonded to the surface of the colloidal particles, thereby affecting the emulsification effect.

Comparing the data of examples/test groups 1-2 and examples/test groups 3-4 in tables 3, 4 and 5, it can be seen that the average particle size of examples/test groups 1-2 is greater than that of examples/test groups 3-4, and the number of days in which delamination occurred and the number of days in which the paint film failed are less than that of comparative examples/control groups 3-4. This shows that the polymerization degree of cardanol polyoxyethylene ether used in examples 3 to 4 is a more preferable technical solution. The emulsifier prepared from the cardanol with the polymerization degree has better emulsifying capacity, can be conveniently crosslinked while ensuring the better emulsifying capacity, and can be used for preparing colloidal particles with smaller particle size.

Comparing the data of examples/test groups 1-2 and examples/test groups 5-6 in tables 3, 4 and 5, it can be seen that the average particle size of examples/test groups 1-2 is greater than that of examples/test groups 5-6, and the number of days in which delamination occurred and the number of days in which the paint film failed are less than that of comparative examples/control groups 5-6. This shows that in examples 5 to 6, using a mixture of two epoxy resins having epoxy values of 0.53 and 0.44, respectively, as a resin raw material, an emulsion having more excellent properties can be obtained.

Comparing the data of examples/test groups 1-2 and examples/test groups 7-8 in tables 3, 4 and 5, it can be seen that the average particle size of examples/test groups 1-2 is greater than that of examples/test groups 7-8, and the number of days in which delamination occurred and the number of days in which the paint film failed are less than that of comparative examples/control groups 7-8. This illustrates the process of examples 7-8 wherein deionized water is added in two portions and after the first stage water addition is complete, the second stage water is added after the system has completed phase inversion, which results in a better performing emulsion. In the adding process of the first stage, the water phase enters the oil phase, water-in-oil is adopted in the first stage, water beads are gradually formed in the oil phase after stirring under the action of the emulsifier, and after sufficient water is added, the stirring is continuously carried out, the water beads are gradually combined, finally phase change is realized, an oil-in-water structure is formed, the viscosity is suddenly reduced, and the emulsion is preliminarily formed. After the phase change is finished, the second stage of water addition is carried out, and the process is mainly to adjust the dispersion degree of the colloidal particles in the water so that the colloidal particles with smaller particle size can be formed under stirring.

Comparing the data of examples/test groups 1-2 and examples/test groups 9-10 in tables 3, 4 and 5, it can be seen that the average particle size of examples/test groups 1-2 is greater than that of examples/test groups 9-10, and the number of days in which delamination occurred and the number of days in which the paint film failed are less than that of comparative examples/control groups 9-10. This illustrates the preferred embodiment of the stirring speed used in step S1 of examples 9-10, which results in a better performing emulsion.

Comparing the data of examples/test groups 1-2 and examples/test groups 11-12 in tables 3, 4 and 5, it can be seen that the average particle diameters of examples/test groups 1-2 and examples/test groups 11-12 are similar, but the days of delamination and the days of paint failure for examples/test groups 1-2 are less than for comparative examples/control groups 11-12. This is because the emulsion was also stirred at a low speed for a while before standing in examples 11 to 12 to remove air bubbles in the emulsion. Although these bubbles do not affect the emulsion particle size at the initial stage, the presence of bubbles can lead to instability of the emulsion and uniformity of the surface of the paint film after curing. Thus illustrating the preferred embodiment of the process of examples 11-12 using low speed stirring.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.