Epoxy resin coating containing stainless steel scales and preparation method thereof

Abstract

The invention discloses an epoxy resin coating containing stainless steel scales and a preparation method thereof. The epoxy resin coating containing the stainless steel scales is prepared from ball-milled stainless steel powder, reactive diluent phenyl glycidyl ether, non-reactive diluent dibutyl ester, E44 epoxy resin, E51 epoxy resin and a T31 curing agent. The preparation method comprises the following steps: ball-milling the stainless steel powder; mixing and stirring the dried stainless steel powder, phenyl glycidyl ether serving as a reactive diluent, dibutyl ester serving as a non-reactive diluent, E44 epoxy resin, E51 epoxy resin and a T31 curing agent according to the weight parts; and ball-milling the stainless steel powder, the phenyl glycidyl ether serving as a reactive diluent, the dibutyl ester serving as a non-reactive diluent.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and particularly relates to an epoxy resin coating containing stainless steel flakes and a preparation method thereof. Background Art

[0002] With the increasingly wide application of epoxy resin coatings, people's requirements for the performance of coatings, such as wear resistance, corrosion resistance, etc., are getting higher and higher. The invention patent with the application number 200810117090.7 involves a high-chlorinated polyethylene coating containing stainless steel flakes and a preparation method thereof. The stainless steel flakes are not pretreated and directly added. The sizes of the stainless steel flakes are inconsistent, which is likely to cause uneven dispersion and irregularity, thus reducing the performance of the coating and the anti-permeability. In the prior art, dry ball milling or mechanical crushing is mostly used to pretreat the flakes, but there is a problem of wide size distribution. The D50 of the flakes prepared by traditional processes fluctuates between 8 - 15 μm, and the particle size distribution index > 0.5, resulting in uneven stacking gaps of the flakes in the coating, and problems of insufficient surface activity and dispersion stability. The surface energy of the untreated flakes is as high as 45 mJ / m 2 , and the interfacial bonding strength with epoxy resin is only 4 - 6 MPa, which is likely to become a stress concentration point. Moreover, the density of the flakes is much higher than that of epoxy resin. The sedimentation rate exceeds 15% within 2 hours after construction. High-speed stirring causes the crushing rate of the flakes to increase by 40%. While the D50 decreases from 10 μm to 6 μm, the aspect ratio deteriorates from 25:1 to 8:1. When a combination of bisphenol A-type epoxy resin and polyamide curing agent is used, the high thermal conductivity of the flakes intensifies the local temperature rise. TGA analysis shows that the exothermic peak temperature shifts by up to 20 °C, triggering microcracks. The difference in the thermal expansion coefficients of the flakes and the resin leads to interfacial stress concentration and a 30% decrease in the pull-out strength.

[0003] Therefore, it is of great significance to develop an epoxy resin coating containing stainless steel flakes and a preparation method thereof that uses wet ball milling to pretreat the stainless steel flakes. Summary of the Invention

[0004] The purpose of the present invention is to solve the above-mentioned deficiencies in the prior art, and to propose an epoxy resin coating containing stainless steel flakes and a preparation method thereof.

[0005] An epoxy resin coating containing stainless steel flakes, the epoxy resin coating containing stainless steel flakes includes stainless steel powder after ball milling and drying, active diluent phenyl glycidyl ether, inactive diluent dibutyl phthalate, E44 epoxy resin, E51 epoxy resin, and T31 curing agent.

[0006] Further, the epoxy resin coating containing stainless steel scales comprises, by weight, 10 - 20 parts of stainless steel powder after ball milling and drying, 10 - 15 parts of reactive diluent phenyl glycidyl ether, 10 - 15 parts of non-reactive diluent dibutyl phthalate, 40 - 50 parts of E44 epoxy resin and E51 epoxy resin, and 10 - 15 parts of T31 curing agent.

[0007] Further, the preparation method of the epoxy resin coating containing stainless steel scales comprises: S1. Add grinding balls, stainless steel powder, ball milling aids, and ball milling solvent absolute ethanol, and obtain the stainless steel powder after ball milling and vacuum drying; S2. Stir the reactive diluent phenyl glycidyl ether and the non-reactive diluent dibutyl phthalate, add E44 epoxy resin and E51 epoxy resin, dissolve under heating, then add T31 curing agent and the stainless steel powder after ball milling and drying, and disperse and stir and ball mill to obtain the epoxy resin coating containing stainless steel scales.

[0008] Further, in S1, the weight ratio of zirconia grinding balls to stainless steel powder is 11:1, the grinding balls are zirconia grinding balls, and the weight part ratio of grinding balls with a diameter of 3mm, grinding balls with a diameter of 5mm, and grinding balls with a diameter of 8mm is 3:5:3; by weight, 11 parts of grinding balls, 1 part of stainless steel powder, 0.25 part of ball milling aids, and 3 parts of ball milling solvent absolute ethanol are added in S1.

[0009] Further, in S1, planetary ball milling technology is adopted for ball milling, the rotation speed is 400r / min, the ball milling time is 3 - 12h, and zirconia ball milling jars and zirconia balls are used as ball milling media.

[0010] Further, in S1, the vacuum drying temperature is 50 - 60°C and the time is 6 - 9h.

[0011] Further, in S2, it is dissolved for half an hour under heating at 40 - 50°C.

[0012] Further, the components included in the ball milling aids are amino-modified nano-silica, 1-ethyl-3-methylimidazolium tetrafluoroborate, amphiphilic block copolymer Pluronic F127, and absolute ethanol.

[0013] Further, the preparation method of the ball milling aids comprises mixing 7wt% amino-modified nano-silica, 12wt% 1-ethyl-3-methylimidazolium tetrafluoroborate, 6wt% amphiphilic block copolymer Pluronic F127 with 75wt% absolute ethanol, and ultrasonic dispersing for 30min.

[0014] Furthermore, the ball milling in the S2 step is electrically and automatically intelligently controlled, and the method includes the following steps: initializing ball milling parameters; collecting the particle size of stainless steel flakes in the slurry, the internal temperature of the ball mill tank, and the slurry viscosity in real time through the sensor module; inputting the collected data into the dynamic parameter optimization model; calculating the deviation value between the current state and the target, driving the adaptive PID controller according to the deviation value, and dynamically adjusting the ball milling speed.

[0015] The epoxy resin coating containing stainless steel flakes and the preparation method thereof proposed by the present invention have the following beneficial effects:

[0016] 1. The stainless steel flakes after ball milling have regular shapes and are arranged in parallel in the base material, which is more regular, improves the permeability and improves the anti-corrosion performance of the coating;

[0017] 2. The ball milling speed and ball milling time at a certain ratio are beneficial to improving the compatibility of stainless steel flakes in epoxy resin, improving uniform dispersion, avoiding agglomeration, shortening the actual drying time of epoxy resin, and enhancing drawing performance, wear resistance and impact resistance;

[0018] 3. Intelligent control has established a particle size-temperature-viscosity coupling model, and adaptive PID control has improved process stability, reduced the incidence of flake agglomeration, and reduced microcrack density. This application synergistically solves industry problems such as the difficulty in achieving both corrosion resistance and flexibility in traditional epoxy coatings and uneven flake dispersion through gradient ball milling process, resin synergistic curing and intelligent dynamic control. It has great application value in harsh environments such as marine engineering and petrochemical industry. DETAILED DESCRIPTION

[0019] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0020] Unless otherwise specified, the examples and comparative examples are parallel tests with the same components, component contents, preparation steps and preparation parameters. The experimental methods in the following examples are conventional methods unless otherwise specified; the parts in the experiments are parts by weight unless otherwise specified; the test materials used in the following examples are analytical reagents (AR) unless otherwise specified, which are purchased from commercial channels.

[0021] The stainless steel powder is 316L stainless steel flake powder from Hoganas, Sweden; the phenyl glycidyl ether is Huntsman PY562; the T31 curing agent is Huntsman modified amine curing agent T31; the amino-modified nano-silica is Evonik Aerosi l R812; the 1-ethyl-3-methylimidazolium tetrafluoroborate is Sigma-Aldrich product number 323449; the amphiphilic block copolymer Pluronic F127 is BASF Pluronic F-127.

[0022] Example 1:

[0023] S1. The weight ratio of zirconia grinding balls to stainless steel powder is 11:1. Add 3 parts of grinding balls with a diameter of 3 mm, 5 parts of grinding balls with a diameter of 5 mm, and 3 parts of grinding balls with a diameter of 8 mm. Add 1 part of stainless steel powder, 0.25 part of ball milling aid, and 3 parts of ball milling solvent anhydrous ethanol. After sealing, use planetary ball milling technology for ball milling at a speed of 400 r / min for 6 h. Use a zirconia ball milling tank and zirconia balls as ball milling media to obtain the ball-milled stainless steel powder. Dry the ball-milled stainless steel powder. The vacuum drying temperature is 55 °C and the time is 8 h to obtain the dried stainless steel powder;

[0024] S2. Add 12 parts of reactive diluent phenyl glycidyl ether and 14 parts of non-reactive diluent dibutyl phthalate to the dissolution tank, mix and stir, add 46 parts of E44 epoxy resin and E51 epoxy resin, dissolve at 45 °C for half an hour, and then add 13 parts of curing agent T31 and 15 parts of the dried stainless steel powder for dispersion, stirring and ball milling.

[0025] Example 2:

[0026] S2. Add 10 parts of reactive diluent phenyl glycidyl ether and 10 parts of non-reactive diluent dibutyl phthalate to the dissolution tank, mix and stir, add 50 parts of E44 epoxy resin and E51 epoxy resin, dissolve at 45 °C for half an hour, and then add 15 parts of curing agent T31 and 15 parts of the dried stainless steel powder for dispersion, stirring and ball milling. Other contents are the same as in Example 1.

[0027] Example 3

[0028] S2. Add 20 parts of reactive diluent phenyl glycidyl ether and 15 parts of non-reactive diluent dibutyl phthalate to the dissolution tank, mix and stir, add 50 parts of E44 epoxy resin and E51 epoxy resin, dissolve at 45 °C for half an hour, and then add 15 parts of curing agent T31 and 20 parts of the dried stainless steel powder for dispersion, stirring and ball milling. Other contents are the same as in Example 1.

[0029] In the above embodiments, the weight ratio of E44 epoxy resin to E51 epoxy resin is 1:1.

[0030] The preparation method of the ball milling aid used in the above embodiments is as follows: Mix 7 wt% amino-modified nano-silica, 12 wt% 1-ethyl-3-methylimidazolium tetrafluoroborate, 6 wt% amphiphilic block copolymer Pluronic F127 with 75 wt% absolute ethanol, and ultrasonically disperse for 30 min.

[0031] In the above embodiments, a model algorithm is used to automatically control the rotation speed, a laser particle size analyzer is used to monitor the scale particle size (D50) in the slurry in real time, a temperature sensor is used to collect the internal temperature of the ball milling tank, and a viscosity sensor is used to online detect the viscosity change of the slurry. Set the initial ball milling parameters as the rotation speed N O to be 400 rpm, the time t0 to be 6 h, and the target temperature T target to be 50 °C. The particle size, temperature, and viscosity data are collected in real time through the sensor module, the collected data is input into the dynamic parameter optimization model, the deviation between the current state and the target is calculated through the model algorithm, and according to the f(t) value, the adaptive PID controller is driven to generate a rotation speed adjustment instruction to dynamically adjust the ball milling rotation speed N(t) and time t. The algorithm formula used is:

[0032] Dynamic parameter optimization model formula:

[0033] Among them, α, β, and γ are weight coefficients determined by machine learning training. α is the weight coefficient of the particle size change rate, β is the weight coefficient of the temperature deviation, γ is the weight coefficient of the viscosity change. The weight coefficient α is taken as 0.1, β is 0.2, and γ is 0.05; D50 is the average particle size of the stainless steel scales, in the unit of μm, T target is the set temperature (50 °C), T real is the temperature of the ball milling tank detected in real time, in the unit of °C, η is the real-time viscosity of the slurry, ηo is the initial viscosity, in the unit of Pa·s; f(t) is the deviation value between the current state and the target.

[0034] The above formula avoids the local optimum caused by single parameter optimization by comprehensively considering the particle size change rate, temperature deviation, and viscosity change. If f(t) < 0, it means that the current state is better than the target (such as the particle size decreasing too fast or the temperature being too low), and the ball milling rotation speed can be reduced to save energy; if f(t) > 0, acceleration adjustment is required.

[0035] Adaptive PID controller formula: Dynamically adjust the ball milling rotation speed N and time t according to the deviation value f(t) between the current state and the target:

[0036]

[0037] Among them, N(t) is the ball milling speed after dynamic adjustment, with the unit of rpm, N0 is the initial speed, with the unit of rpm, K p is the proportional gain coefficient, with the unit of rpm / μm, K i is the integral gain coefficient, with the unit of rpm / (μm·s), Kd is the differential gain coefficient, with the unit of rpm·s / μm, e(t) is the particle size deviation, with the unit of μm, K p 、K i and K d are adaptive gain coefficients. When it is detected that D50 > 5μm, the algorithm increases the speed to 450rpm; when the temperature exceeds 52°C, a cooling medium is injected and the speed is reduced to 380rpm; when D50 ≤ 5μm and the temperature fluctuation < 2°C, the ball milling is terminated. The gain coefficients are usually taken as Kp = 10rpm / μm, Ki = 2rpm / (μm·s), Kd = 5rpm·s / μm.

[0038] The average particle size D50 of the coating that is not automatically controlled by the above model algorithm is 8.2μm; the particle size distribution PDI is 0.35, the ball milling energy consumption is 98%, and the coating abrasion resistance is 38mg. While by automatically controlling the speed with the model algorithm, the average particle size D50 is 4.5μm, the particle size distribution PDI is 0.18, the ball milling energy consumption is 82%, and the coating abrasion resistance is 22mg. Then, by detecting the particle size, temperature, and viscosity to automatically adjust the speed, the coordinated control of multiple parameters is beneficial to improving the comprehensive performance of an epoxy resin coating containing stainless steel flakes.

[0039] Comparative Example 1:

[0040] In S1, no ball milling aid is used, and only anhydrous ethanol is used for ball milling, and the others are the same as in Example 1.

[0041] Comparative Example 2:

[0042] The ratio of E44 to E51 resin is 3:1, and the total amount is kept at 50 parts, and the others are the same as in Example 1.

[0043] Performance test: The epoxy resin coatings prepared in the examples and comparative examples were subjected to performance tests: Drying time: Tested according to the method shown in BK III; Pull-off test: Tested according to the method shown in ISO 4624 (ASTM D 4541); Abrasion resistance: Tested according to the method shown in ASTM D 4060, with a grinding wheel CS-17 and a load of 1000g; Impact resistance: Tested according to the method shown in ISO6272-80, with a dry film of 2×150μm; Flexibility: Tested according to the method shown in ISO 1519, with a round shaft bend and a dry film of 320μm; Salt spray resistance: Tested according to the method shown in ASTM B 117. The test results are shown in Table 1.

[0044] Table 1

[0045]

[0046] As mentioned above, it is only the preferred specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, shall be covered by the protection scope of the present invention.

Claims

1. An epoxy resin coating containing stainless steel flakes, characterized in that: The epoxy resin coating containing stainless steel flakes comprises stainless steel powder after ball milling and drying, active diluent phenyl glycidyl ether, inactive diluent dibutyl ester, E44 epoxy resin, E51 epoxy resin and T31 curing agent.

2. The epoxy resin coating containing stainless steel flakes according to claim 1, characterized in that: The epoxy resin coating containing stainless steel flakes comprises, by weight, 10-20 parts of ball-milled and dried stainless steel powder, 10-15 parts of active diluent phenyl glycidyl ether, 10-15 parts of inactive diluent dibutyl ester, 40-50 parts of E44 epoxy resin and E51 epoxy resin, and 10-15 parts of T31 curing agent.

3. The epoxy resin coating containing stainless steel flakes according to claim 1, characterized in that: The preparation method of the epoxy resin coating containing stainless steel flakes comprises: S1, adding grinding balls, stainless steel powder, ball milling aid and ball milling solvent anhydrous ethanol, and obtaining the ball-milled stainless steel powder after ball milling and vacuum drying; S2, stirring the active diluent phenyl glycidyl ether and the inactive diluent dibutyl ester, adding E44 epoxy resin and E51 epoxy resin, dissolving them under heating, and then adding T31 curing agent and the ball-milled and dried stainless steel powder, dispersing, stirring and ball milling to obtain the epoxy resin coating containing stainless steel flakes.

4. The epoxy resin coating containing stainless steel flakes according to claim 3, characterized in that: The weight ratio of the grinding balls to the stainless steel powder in S1 is 11:1, the grinding balls are zirconia grinding balls, and the weight ratio of the grinding balls with a diameter of 3 mm, the grinding balls with a diameter of 5 mm and the grinding balls with a diameter of 8 mm is 3:5:3; by weight, 11 parts of grinding balls, 1 part of stainless steel powder, 0.25 parts of ball milling aids and 3 parts of ball milling solvent anhydrous ethanol are added to S1.

5. The epoxy resin coating containing stainless steel flakes according to claim 3, characterized in that: The ball milling in S1 adopts planetary ball milling technology, with a rotation speed of 400 r / min, a ball milling time of 3-12 h, and a zirconia ball milling jar and zirconia balls as ball milling media.

6. The epoxy resin coating containing stainless steel flakes according to claim 3, characterized in that: The vacuum drying temperature in S1 is 50-60° C. and the time is 6-9 hours.

7. The epoxy resin coating containing stainless steel flakes according to claim 3, characterized in that: Dissolve in S2 at 40-50°C for half an hour.

8. The epoxy resin coating containing stainless steel flakes according to claim 3, characterized in that: The ball milling aid comprises components of amino-modified nano silicon dioxide, 1-ethyl-3-methylimidazole tetrafluoroborate, amphiphilic block copolymer Pluronic F127 and anhydrous ethanol.

9. The epoxy resin coating containing stainless steel flakes according to claim 8, characterized in that: The preparation method of the ball milling aid comprises mixing 7wt% amino-modified nano silicon dioxide, 12wt% 1-ethyl-3-methylimidazolium tetrafluoroborate, 6wt% amphiphilic block copolymer Pluronic F127 and 75wt% anhydrous ethanol, and performing ultrasonic dispersion for 30 minutes.

10. The epoxy resin coating containing stainless steel flakes according to claim 3, characterized in that: The ball milling in step S2 is electrically and automatically intelligently controlled, and the method comprises the following steps: initializing ball milling parameters; collecting the particle size of stainless steel flakes in the slurry, the internal temperature of the ball milling tank, and the slurry viscosity in real time through a sensor module; inputting the collected data into a dynamic parameter optimization model; calculating the deviation value between the current state and the target, driving an adaptive PID controller according to the deviation value, and dynamically adjusting the ball milling speed.

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