CN115595010A - Non-oriented silicon steel insulating coating liquid for improving secondary coating of electrophoretic paint, and preparation method and application thereof - Google Patents
Non-oriented silicon steel insulating coating liquid for improving secondary coating of electrophoretic paint, and preparation method and application thereof Download PDFInfo
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- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
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Abstract
The invention discloses a non-oriented silicon steel insulation coating liquid suitable for improving secondary coating of electrophoretic paint, which is prepared from vinyl acetate-acrylic emulsion, film-forming additive, rheological agent, boric acid, polyalcohol, defoaming agent and deionized water according to the mass ratio of 100: 1-10: 2-7: 0.1-0.8: 0.1-1): (0.1-0.5): (60-150). The coating formed by the insulating coating liquid has a transparent and smooth surface, excellent adhesiveness and antirust performance, and particularly, the electrophoretic paint secondary coating coated on the coating has good adhesiveness and a good secondary coating effect.
Description
Technical Field
The invention relates to a cold-rolled silicon steel sheet coating, in particular to non-oriented silicon steel insulating coating liquid suitable for improving secondary coating of electrophoretic paint, and a preparation method and application thereof.
Background
The cold-rolled non-oriented silicon steel sheet is a ferrosilicon soft magnetic material with the silicon content of 0.4-3.0 percent, is used as a basic steel raw material of various rotating motor iron cores, is widely applied to downstream electromechanical industry, and has higher national economic benefit.
The cold-rolled non-oriented silicon steel sheet is mainly laminated together in riveting, welding and other modes in the downstream motor iron core manufacturing process, so that the motor is ensured to have excellent electromagnetic performance in the rotating process, and meanwhile, the motor has certain mechanical shock resistance and stability. With the higher and higher requirements of the market on the comprehensive performance of the motor, after the iron core is manufactured by a motor manufacturer exported to the European and American markets, the secondary coating is coated on the surface of the iron core, so that the insulation grade of the motor is further improved. The coating of the secondary coating mainly uses organic resin such as phenolic resin, epoxy resin, acrylic resin and the like as a base material, and additives such as black slurry, surfactant and the like are used as auxiliary materials, and the coating process mainly comprises spraying, dipping and electrophoretic coating.
The electrophoretic coating is a coating method in which an article to be coated is immersed in a water-soluble coating and electrified, and under the action of an electric field force, paint is deposited on the article to be coated by the physical and chemical action generated by the electric field. According to the functional classification of electrophoretic paint, the electrophoretic paint can be divided into electrophoretic primer, primer-topcoat electrophoresis and secondary electrophoresis. Generally, electrophoretic coating is classified into anodic electrophoresis and cathodic electrophoresis according to the type of charges carried by electrophoretic paint and the power supply used during electrophoresis. Meanwhile, the water-based paint is a necessary trend of environmental protection development of the paint, and the electrophoretic paint is also actively developed to the water-based paint, namely a two-phase dispersion system which takes water and a cosolvent as dispersion media and takes water-based resin as a dispersion phase is formed in the water-based electrophoretic paint, and an electric double layer structure is formed on the interface of the two phases due to the dissociation of resin colloidal particles, so that a certain potential difference is formed. Wherein, the resin colloidal particles have positive charges, and the colloidal particles can move to the cathode in the electrophoresis process and emit electrons on the surface of the cathode to be deposited on the surface of the cathode, so that the most of the current aqueous electrophoretic coatings adopt a cathode electrophoresis mode.
The cathode electrophoresis is that in a direct current electric field, resin colloidal particles with positive charges are firstly deposited at the parts with the minimum resistance and the highest current density, such as the cut surface of an iron core and a riveting punching part, and then are deposited at the part deviating from the cathode. The electrophoretic coating is one of coating modes, and has the greatest characteristic of good coating effect on iron core workpieces with complex shapes and structures. After electrophoretic coating, the iron core needs to pass through a coating curing oven, and the coating generates resin crosslinking reaction at a certain baking temperature to generate a denser coating film.
For steel mills, the non-oriented silicon steel sheets used for secondary electrophoretic coating only account for a small proportion of the production, and most finished products are coated with a thin semi-inorganic semi-organic chromate-propylene emulsion insulating coating before steel plates leave the factory. The coating makes full use of the chemical combination reaction of inorganic component chromate and the steel plate matrix, and the organic component propylene emulsion forms a compact coating film through the resin crosslinking reaction. Therefore, the composite coating film has excellent insulating property and punching performance and certain antirust property.
Therefore, if downstream motor manufacturers need to perform secondary electrophoretic coating on the surface of the iron core, the silicon steel sheet primer must reduce the surface insulation resistance as much as possible on the premise of ensuring the basic insulation performance and the rust-proof performance, or be easily cracked into short-chain molecules or desorbed from the surface of the steel sheet in the electrophoretic coating pretreatment process, so as to ensure that enough current density smoothly passes through the thinner primer layer in the secondary electrophoretic coating process, so that the water-based electrophoretic coating has higher throwing power and is deposited to form a film on the surface of the iron core. However, the current mainstream chromate-acrylic resin insulating coating has the defects that the film formation is compact, the surface insulation resistance is high, the current density passing through the iron core is small, the electrophoretic paint cannot be attached to the surface of the iron core, and the electrophoretic paint falls off.
To solve the above problems, steel mills have been improving the film thickness of insulating coatings of chromate-acrylic resins by reducing the film thickness, but the film thickness is limited by the conditions of the existing coating equipment, which often causes unnecessary surface quality defects such as missing coating, coating mottling, etc.
In the prior art, CN109504202A discloses a chromate-propylene resin coating liquid with good secondary coating adhesion and a preparation method and application thereof, which comprises an inorganic component, a polyol and an acrylic emulsion according to the mass ratio of (5-20) to (0.1-1.0) to 1; wherein the inorganic component comprises 1 to 8 parts of magnesium oxide, 14 to 29 parts of chromic anhydride, 0.1 to 0.8 part of boric acid and 50 to 95 parts of water by mass; CN110283480A discloses a semi-organic-semi-inorganic silicon steel sheet coating liquid for welding, which is prepared from inorganic components, organosilicon modified acrylic emulsion, silane polymer, polyol and defoaming agent according to the mass ratio of (8-24) to 1: (0.1-0.8) to (0.1-1) to (0.01-0.05); the inorganic component comprises 1-8 parts of magnesium oxide, 14-29 parts of chromic anhydride, 0.1-0.8 part of boric acid and 50-95 parts of water by mass. CN110885571A discloses an energy-saving non-oriented silicon steel coating liquid and a preparation method and application thereof, which consists of inorganic components, epoxy acrylate composite emulsion, silane polymer, polyol and defoaming agent according to the mass ratio of (6-22) to 1 to (0.1-1.0) to (0.01-0.05); the inorganic component comprises 15-30 parts of silica sol, 14-28 parts of aluminum dihydrogen phosphate, 10-20 parts of chromium dihydrogen phosphate, 0.1-0.8 part of boric acid and 40-100 parts of water by mass. However, these techniques are designed for the non-oriented silicon steel in the downstream electric machine plant, and the coating formula coated on the surface of the non-oriented silicon steel is redesigned, so that a certain specific coating performance advantage is remarkably improved before the improvement of the coating insulation and adhesion, and the silicon steel sheet is adapted to the application scenes of different users. Therefore, when the technology is applied to secondary electrophoretic coating, the current density in the electrophoretic process is low due to the excellent comprehensive performance of the technology, so that the aqueous electrophoretic coating cannot be run through to the base coating.
CN114031997A discloses a coating liquid suitable for coating the surface of a non-oriented silicon steel ultrathin strip, which consists of water-soluble acrylic resin, a film forming aid, a salt spray resistant aid, a leveling agent, nano zirconium hydroxide, a defoaming agent and water according to the mass ratio of 100 (2-8), (1-3), (1-5), (0-1), (0.1-0.5) and (70-130). However, the invention is mainly developed aiming at the coating characteristics of the non-oriented ultra-thin strip, so that the local surface tension of the coating liquid fluctuates too much or too little in the coating process of the conventional non-oriented silicon steel, so that the leveling property of the coating liquid cannot be matched with the surface of the steel plate, and the coating mottling defect is generated.
Therefore, the non-oriented silicon steel insulating coating liquid specially used for improving the secondary coating of the electrophoretic paint, and the preparation method and the application thereof are particularly necessary.
Disclosure of Invention
The invention aims to solve the technical problem of providing non-oriented silicon steel insulating coating liquid suitable for improving the secondary coating of electrophoretic paint and a preparation method thereof aiming at the defects in the prior art. The coating formed by the insulating coating liquid has a transparent and smooth surface, excellent adhesiveness and excellent antirust performance, and particularly, the electrophoretic paint secondary coating coated on the coating has good adhesiveness and a good secondary coating effect.
The technical scheme adopted by the invention for solving the problems is as follows:
a non-oriented silicon steel insulating coating liquid suitable for improving secondary coating of electrophoretic paint is prepared from vinyl acetate-acrylic emulsion, film-forming assistant, rheological agent, boric acid, polyol, defoaming agent and deionized water in a mass ratio of 100 to (1-10) to (2-7) to (0.1-0.8) to (0.1-1): (0.1-0.5): (60-150).
Preferably, the non-oriented silicon steel insulation coating solution suitable for improving the secondary coating of the electrophoretic paint comprises vinyl acetate-acrylic emulsion, a film-forming assistant, a rheological agent, boric acid, polyol, a defoaming agent and deionized water according to the mass ratio of 100: 3-7: 3-5: 0.2-0.5: 0.3-0.7): (0.2-0.4): (80-125).
According to the scheme, the vinyl acetate-acrylic emulsion is prepared from four monomers, namely vinyl acetate, butyl acrylate, acrylic acid and hydroxyethyl methacrylate, a composite emulsifier and an initiator, namely ammonium persulfate, as main raw materials. Furthermore, the mass ratio of the raw materials of the vinyl acetate, the butyl acrylate, the acrylic acid, the hydroxyethyl methacrylate, the composite emulsifier and the initiator ammonium persulfate is (30-80): (30-60): (5-15): (1-10): (1-5). More preferably, the mass ratio of the raw materials of the vinyl acetate, the butyl acrylate, the acrylic acid, the hydroxyethyl methacrylate, the composite emulsifier and the initiator ammonium persulfate is (45-65): (35-55): (8-11): (2-8): (2-4). Wherein the composite emulsifier is a mixture of sodium dodecyl benzene sulfonate (SDS) and alkylphenol polyoxyethylene (TX-9), and the mixing mass ratio of the sodium dodecyl benzene sulfonate (SDS) to the alkylphenol polyoxyethylene is 1: 1-3.
According to the scheme, the preparation method of the vinyl acetate-acrylic emulsion comprises the following steps:
(1) Uniformly dividing a monomer vinyl acetate into A and B, wherein A is used as a seed emulsion raw material; b, uniformly stirring the mixture with butyl acrylate, acrylic acid and hydroxyethyl methacrylate in a container at the temperature of between 20 and 30 ℃ to obtain a mixed monomer;
(2) Dividing initiator ammonium persulfate into C and D according to the mass ratio of 1: 1-3, wherein C is used as a seed emulsion initiator, and D is used as an initiator for mesochite polymerization of a mixed monomer;
(3) The composite emulsifier is divided into two parts of E and F according to the mass ratio of 1 to (1-3), wherein E is used as a seed emulsion emulsifier, and F is used as an emulsifier for shell polymerization of a mixed monomer;
(4) Adding deionized water and polyvinyl alcohol into a four-neck flask which is filled with a reflux condenser pipe, a stirrer, a thermometer and a feeding device and is protected by nitrogen according to the mass ratio of (8-12) to 1, heating to 85-95 ℃ in a constant-temperature water bath to completely dissolve the polyvinyl alcohol, cooling to 45-55 ℃, adding a composite emulsifier E and acid-base buffer sodium dihydrogen phosphate, adding a part of vinyl acetate A, and stirring and pre-emulsifying for 10-60 min at 30-60 ℃; heating to 60-90 ℃, adding a part of the initiator C, continuing to dropwise add the residual vinyl acetate A and the residual initiator C when the emulsion is in a blue phase, and after all the materials are added, keeping the temperature at 70-80 ℃ for 30-60 min to obtain seed emulsion;
(5) And (3) heating the seed emulsion to 80-90 ℃, then uniformly dripping the mixed monomer, the initiator D and the composite emulsifier F into the reactor within 1-2 h, continuously preserving the heat for 60-90 min after all the materials are added, and cooling and adjusting the pH value to obtain the vinyl acetate-acrylic emulsion with the core-shell structure.
In step (3), the polyvinyl alcohol is preferably a mixture of PVA1799 and PVA1788, and the mixing mass ratio of the two is 1 to (1-2).
According to the scheme, the film-forming assistant is one or two of dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether and dipropylene glycol monobutyl ether.
In the invention, the rheological agent is polyether modified trisiloxane or polyether modified tetrasiloxane; the polyalcohol is ethylene glycol or glycerol; the defoaming agent is one or more of polyoxyethylene polyoxypropylene pentaerythritol ether, polyoxyethylene polyoxypropylene amine ether, polyoxypropylene glycerol ether, polyoxypropylene polyoxyethylene glycerol ether and polydimethylsiloxane.
The invention also provides a preparation method of the non-oriented silicon steel insulating coating liquid suitable for improving the secondary coating of the electrophoretic paint, which comprises the following specific steps: sequentially adding deionized water and boric acid into a reaction container, stirring for 180-300 min to fully dissolve the boric acid, sequentially adding the vinyl acetate-acrylic emulsion, the film-forming assistant, the rheological agent and the polyol, stirring for 60-90 min after adding one component, finally adding the defoaming agent, and stirring for 120-150 min; and standing for 20-30 min after the coating liquid is prepared, and filtering residual particles in the coating liquid by using a filter screen with the mesh number of 60-100 to obtain the non-oriented silicon steel insulating coating liquid suitable for improving the secondary coating of the electrophoretic paint.
The invention also provides a use method of the non-oriented silicon steel insulating coating liquid suitable for improving the secondary coating of the electrophoretic paint, which comprises the following specific processes: the non-oriented silicon steel insulating coating liquid suitable for improving the secondary coating of the electrophoretic paint is added with water to control the specific gravity range to be 1.00-1.20, preferably 1.05-1.15, then coated on the surface of a non-oriented silicon steel plate, and then placed in a drying furnace to be dried and cured at a certain temperature to form an insulating coating.
Furthermore, the coating method of the coating liquid adopts a coating machine with two grooved rollers, the rolling reduction of the coating roller is controlled by adjusting the pressure between the rollers by a gap adjusting device consisting of worm gears and worms at two ends of the coating roller and a precise screw rod, and the uniform target coating thickness can be obtained. Wherein, the technical parameters of the coating roller are as follows: the upper and lower rollers have a hardness of 52-60 degrees and a hardness of 110 (0.08-0.16) mm (x 56 teeth/1 inch); preferably, the upper and lower rolls are 110 ° × (0.08-0.12) mm × 56 teeth/1 inch, and the hardness is 52-60 °;
further, the coating amount of the coating liquid is 0.3 to 1 μm, preferably 0.3 to 0.6 μm;
further, the curing plate temperature (PMT) of the dry cured steel plate substrate was: 240 to 300 ℃/20 to 80S, preferably 255 to 285 ℃/30 to 60S. The drying and curing are finished in the air atmosphere in the drying furnace, and the steel plate matrix heating and coating curing temperatures come from the radiation tube heat radiation heating and the burner open fire heating in the drying furnace and the combination of the radiation tube heat radiation heating and the burner open fire heating so as to ensure that the temperature in the furnace meets the requirement of the temperature PMT of the steel plate substrate curing plate.
The non-oriented silicon steel is a cold-rolled non-oriented silicon steel plate, surface iron scales of the non-oriented silicon steel hot-rolled plate with the thickness of 1.8-2.8 mm and the silicon content of 0.4% -3.0% are removed through acid cleaning, the steel plate is rolled to the target thickness of 0.35-0.65 mm by a rolling mill, and decarburizing annealing (decarburizing annealing can be omitted) and grain recovery annealing are completed through continuous high-speed plate passing by a continuous annealing machine set, and the surface of the steel plate is required to be clean and dry and free of foreign matters before coating. The magnetic level of the non-oriented silicon steel conforms to the 1 st part of the national standard GB/T2521.1-2016 cold-rolled electrical steel by the full process: grain non-oriented steel strip (sheet) ". Specifically, the non-oriented silicon steel is suitable for non-oriented medium and low grades such as 50W600, 50W800, 50W1000, 65W600, 65W800 and the like.
Compared with the prior art, the invention has the beneficial effects that:
1) The non-oriented silicon steel insulating coating liquid taking the vinyl acetate-acrylic emulsion as the main component is baked at a certain temperature to form a film. Compared with the traditional chromic acid inorganic salt-pure acrylic emulsion semi-inorganic semi-organic coating, the crosslinking density of each monomer of the vinyl acetate acrylic emulsion prepared by the method is smaller than that of pure acrylic emulsion when the coating is cured, no inorganic component is added, and the cured coating and a steel plate are combined only through mechanical adhesion; the inorganic component in the latter and the steel plate have chemical combination reaction at the interface combination part and simultaneously have combined action with the coating through mechanical adhesion, so the adhesion force of the former is far smaller than that of the latter. However, in the process of applying the non-oriented silicon steel to the secondary coating of the electrophoretic paint, after earlier oil removal and weak alkaline washing and drying intervention treatment, the non-oriented silicon steel is easy to desorb from a steel plate substrate, so that the surface insulation resistance is greatly reduced, the cathode current is obviously increased in the electrophoresis process, and the electrophoretic paint is easier to coat, so that the problem of poor electrophoretic coating is solved, and the embodiment of the invention fully utilizes the film forming property of the vinyl acetate-acrylic emulsion.
2) The non-oriented silicon steel insulating coating liquid disclosed by the invention combines the characteristics of high silicon content and large specific surface energy of a non-oriented silicon steel plate, further improves the coating film forming quality by adding auxiliary film forming substances such as a film forming additive, a rheological agent and the like, and better meets the requirements of downstream customers on electrophoretic secondary coating processing of silicon steel sheets and helps the users to expand the application added value of products although the non-oriented silicon steel insulating coating liquid is slightly poorer in insulating property than the traditional chromic acid inorganic salt-pure acrylic emulsion semi-inorganic semi-organic coating on the premise of ensuring the surface quality of a steel mill and the antirust requirements of steel coil transportation and storage.
3) The curing temperature of the non-oriented silicon steel insulating coating liquid taking the vinyl acetate-acrylic emulsion as the main component is lower than that of the traditional chromic acid inorganic salt-pure acrylic resin organic coating, so that the curing furnace is favorable for reducing the combustion load and energy consumption of the coating curing furnace, and the consumption of unit equipment and spare parts can be greatly reduced.
Detailed Description
In order to better understand the present invention, the following examples are further provided to illustrate the content of the present invention, but the present invention is not limited to the following examples.
In the following examples, the polyvinyl alcohol is a mixture of model PVA1799 and PVA1788, and the mixing ratio of the two is 4:6; the defoaming agent is prepared by mixing polyoxyethylene polyoxypropylene ether and polydimethylsiloxane according to the mass ratio of 1: 1.
In the following examples, the non-oriented silicon steel is selected from the non-oriented medium and low grade 50W1000, which is prepared by pickling a hot-rolled non-oriented silicon steel plate with a thickness of 2.3mm and a silicon content of 0.4% to remove surface scale, rolling the steel plate to a target thickness of 0.50mm with a rolling mill, and processing the steel plate to 95% 2 +5％H 2 And (4) carrying out grain recovery annealing (830 ℃/30 s) under a protective atmosphere. The non-oriented silicon steel has a magnetic level up to P 1.5/50 ＝5.3W/kg，B 5000/50 =1.74T, and the steel sheet surface must be ensured to be clean and dry and free of foreign matter before coating.
Examples 1 to 5
The non-oriented silicon steel insulating coating liquid suitable for improving the secondary coating of the electrophoretic paint, provided by the invention, consists of vinyl acetate-acrylic emulsion, a film forming additive dipropylene glycol monopropyl ether, a rheological agent polyether modified tetrasiloxane, boric acid, glycerol, a defoaming agent and deionized water according to the mass ratio of 100: 1-10: 2-7: 0.1-0.8: 0.1-1: 0.1-0.5: 60-150, and the specific ratio of each embodiment is shown in Table 1;
the vinyl acetate-acrylic emulsion is prepared from vinyl acetate, butyl acrylate, acrylic acid and hydroxyethyl methacrylate, a composite emulsifier (SDS and TX-9 are mixed according to the mass ratio of 1: 2) and an initiator ammonium persulfate as main raw materials according to the mass ratio of (30-80) to (30-60) to (5-15) to (1-10) to (1-5), and the specific ratio of each embodiment is shown in Table 2.
TABLE 1 general ingredients and proportioning table
| Components | Example 1 | Example 2 | Example 3 | Example 4 | Example 5 |
| Vinyl acetate acrylic emulsion | 100 | 100 | 100 | 100 | 100 |
| Film forming aid | 1.0 | 3.5 | 5.5 | 7.0 | 8.5 |
| Rheological agent | 2.0 | 3.0 | 4.0 | 5.0 | 6.5 |
| Boric acid | 0.1 | 0.2 | 0.3 | 0.5 | 0.7 |
| Polyhydric alcohols | 0.1 | 0.3 | 0.5 | 0.7 | 0.9 |
| Defoaming agent | 0.1 | 0.2 | 0.3 | 0.4 | 0.5 |
| Deionized water | 65 | 85 | 90 | 125 | 145 |
TABLE 2 vinyl acetate-acrylic emulsion composition and proportioning table
In the tables, the units of the components are parts by mass, and parts by mass represent the same mass in the same table, and different tables represent different masses.
The preparation method and the use method of the non-oriented silicon steel insulating coating liquid suitable for improving the secondary coating of the electrophoretic paint in each embodiment comprise the following specific steps:
1. preparation of vinyl acetate/acrylic emulsion
(1) Uniformly dividing a monomer vinyl acetate into A and B, wherein A is used as a seed emulsion raw material; b, uniformly stirring the mixture with butyl acrylate, acrylic acid and methyl hydroxyethyl acrylate in a container at the temperature of between 20 and 30 ℃ to obtain a mixed monomer;
(2) Dividing initiator ammonium persulfate into two parts C and D according to the mass ratio of 1: 2, wherein C is used as a seed emulsion initiator, and D is used as an initiator for mesochite polymerization of a mixed monomer;
(3) Mixing a composite emulsifier SDS and TX-9 according to the mass ratio of 1: 2, and then dividing the mixture into two parts, namely E and F according to the mass ratio of 1: 2, wherein E is used as a seed emulsion emulsifier, and F is used as an emulsifier for mesochite polymerization of a mixed monomer;
(4) Deionized water and polyvinyl alcohol were mixed in a 10: adding the mixture into a four-neck flask which is filled with a reflux condenser pipe, a stirrer, a thermometer and a feeding device and is filled with nitrogen protection in a mass ratio of 1, heating to 90 ℃ in a constant-temperature water bath to completely dissolve polyvinyl alcohol, cooling to 50 ℃, adding a composite emulsifier E and acid-base buffer sodium dihydrogen phosphate, adding a part of vinyl acetate A, and stirring and pre-emulsifying for 35min at 45 ℃; heating to 75 ℃, adding a part of the initiator C, continuing to dropwise add the residual vinyl acetate A and the residual initiator C when the emulsion is in a blue phase, and after all the materials are added, keeping the temperature at 75 ℃ for 45min to obtain seed emulsion;
(5) And (3) heating the seed emulsion to 85 ℃, then uniformly dropwise adding the mixed monomer, the initiator D and the composite emulsifier F into the reactor within 1.5h, continuously keeping the temperature for 75min after all materials are added, and reducing the temperature to adjust the pH value to obtain the vinyl acetate-acrylic emulsion with the core-shell structure.
2. Preparation of masking liquid
Sequentially adding deionized water and boric acid into a reaction container, stirring for 240min to fully dissolve the boric acid, sequentially adding the vinyl acetate-acrylic emulsion, the film-forming aid dipropylene glycol monopropyl ether, the rheological agent polyether modified tetrasiloxane and the glycerol, stirring for 75min after adding one component, finally adding the defoaming agent, and stirring for 150min; and standing for 30min after the coating liquid is prepared, and filtering residual particles in the coating liquid by using a filter screen with the mesh number of 80 to obtain the non-oriented silicon steel insulation coating liquid suitable for improving the secondary coating of the electrophoretic paint.
3. Method of use
(1) The non-oriented silicon steel insulating coating liquid is added with water to control the specific gravity to be about 1.10, and then the non-oriented silicon steel insulating coating liquid is coated on the surface of a non-oriented silicon steel plate, wherein the coating amount is calculated by the coating thickness, and the coating thickness is 0.3-1 mu m, preferably 0.3-0.6 mu m.
In the step, a coating mode adopts a two-roller coating machine with grooves, the rolling reduction amount of the coating roller is controlled by adjusting the pressure between the rollers through a gap adjusting device consisting of worm gears and worms at two ends of the coating roller and a precise screw rod, and the uniform target coating thickness can be obtained. Wherein, the technical parameters of the coating roller are as follows: the upper and lower rollers have a hardness of 52-60 degrees and a hardness of 110 (0.08-0.16) mm (x 56 teeth/1 inch); preferably, the upper and lower rollers are 110 DEG X (0.08-0.12) mm X56 teeth/1 inch, and the hardness is 52-60 DEG;
(2) Placing the non-oriented silicon steel plate coated with the coating liquid in a drying furnace, and drying and curing at a certain temperature to form an insulating coating; wherein, the curing plate temperature (PMT) of the drying curing steel plate substrate is as follows: 240-300 ℃/20-80S, preferably 255-285 ℃/30-60S.
Comparative example 1
By taking a formula of original magnesium salt and pure acrylic resin as a comparison, the mass proportions of inorganic components in the formula of the original magnesium salt coating liquid are 3 parts of magnesium oxide, 20 parts of chromic anhydride, 80 parts of water, 0.1 part of boric acid and 10 parts of organic component acrylic emulsion; wherein the raw materials of the acrylic emulsion are polymerized by 30 parts of methyl methacrylate, 60 parts of ethyl acrylate and 3 parts of hydroxymethyl acrylamide.
Comparative example 2
The acrylic emulsion in comparative example 1 was replaced with an acrylic emulsion, and the other components were not changed for comparison.
Comparative example preparation of coating solution and coating curing process are basically the same as in each example, and specific process parameters are detailed in table 3.
Table 3 table of curing parameters of the coatings of the examples
Test example
The results of tests on the coating applicability, interlayer resistance, gloss, and salt spray resistance of the non-oriented silicon steel with an insulating coating, and the like, which were prepared in each of the examples and comparative examples, are shown in table 4. The coating test method used was as follows:
1) Interlayer resistance: and testing by using an interlayer resistance tester according to GB/T2522-2007.
2) Pencil hardness: the test was carried out with a bench pencil hardness tester according to GB/T6739-2006 using Mitsubishi pencil.
3) Gloss testing: the test was carried out with a gloss meter according to GB 9754-2007.
4) Salt spray resistance: and (4) carrying out neutral salt spray resistance test according to the method in GB 2423.17-93.
5) T bending: the test is carried out by a cylindrical bending tester according to GB/T13488-2006.
6) Pretreating the steel plate coated with the electrophoretic paint for the second time: with NaHCO at pH 10 3 Soaking in weak base at 60 deg.C for 0.50h, eluting, and baking in oven at 220 deg.C for 1 hr.
7) Electrophoretic paint secondary coating adhesion: and (3) detecting the adhesion of the secondary electrophoretic paint coating by using a coating adhesion tester-QFH (quad Flat No-lead) knife.
8) Coating film thickness after coating curing: the measurements were carried out with a membrane measuring instrument of the German Phil Hirscher specification model DELTASCOPE FMP 30.
Table 4 table of coating properties of each example
As can be seen from table 4: the comparative example 1 in the invention is a traditional chromic acid inorganic salt-pure acrylic emulsion semi-inorganic semi-organic coating, and experimental results show that the coating steel mill has high factory interlayer resistance, and the interlayer resistance is still high after the steel plate is pretreated by the electrophoretic paint for secondary coating, so that the coating is difficult to be applied to the electrophoretic paint for secondary coating; the comparative example 2 is that the vinyl acetate-acrylic emulsion replaces the pure acrylic emulsion to be used as a main film forming substance, and the experimental result shows that the application effect of the vinyl acetate-acrylic emulsion in the traditional semi-inorganic semi-organic coating is obviously inferior to that of the pure acrylic emulsion, which is the application limitation of the vinyl acetate-acrylic emulsion in the non-oriented silicon steel coating.
In the invention, the examples 1 to 5 are all the results of mutually compounding different components in the coating development process, the formed coating has good surface and excellent adhesiveness and antirust performance, particularly, the electrophoretic paint secondary coating coated on the coating has good adhesiveness and good secondary coating effect, the insulation resistance of the coating is reduced after pretreatment before secondary coating, and the electrophoretic paint secondary coating effect and quality are good. The coating obtained in the embodiment 3 has good surface brightness and good coating property, the insulation resistance of the coating after pretreatment before secondary coating is obviously reduced, the secondary coating effect and quality of the electrophoretic paint are optimal, and the coating is greatly improved compared with the comparative examples 1-2, so that the aim of optimizing the coating formula is fulfilled.
The above description is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can make various modifications and changes without departing from the inventive concept, and these modifications and changes are all within the scope of the present invention.
Claims (10)
1. The non-oriented silicon steel insulating coating liquid suitable for improving the secondary coating of the electrophoretic paint is characterized by comprising vinyl acetate-acrylic emulsion, a film-forming assistant, a rheological agent, boric acid, polyol, a defoaming agent and deionized water according to the mass ratio of 100: 1-10: 2-7: 0.1-0.8: 0.1-1): (0.1-0.5): (60-150); the vinyl acetate-acrylic emulsion is prepared from vinyl acetate, butyl acrylate, acrylic acid, hydroxyethyl methacrylate and an initiator serving as main raw materials.
2. The non-oriented silicon steel insulating coating liquid suitable for improving the secondary coating of the electrophoretic paint, as claimed in claim 1, wherein the mass ratio of the vinyl acetate-acrylic emulsion to the film forming additive to the rheological agent to the boric acid to the polyhydric alcohol to the defoaming agent to the deionized water is 100 to (3-7) to (3-5) to (0.2-0.5) to (0.3-0.7): (0.2-0.4): (80-125).
3. The non-oriented silicon steel insulating coating solution suitable for improving the secondary coating of the electrophoretic paint is characterized in that the mass ratio of the vinyl acetate to the butyl acrylate to the acrylic acid to the hydroxyethyl methacrylate, the composite emulsifier to the ammonium persulfate as the initiator is (30-80) to (30-60) to (5-15) to (1-10) to (1-5).
4. The non-oriented silicon steel insulating coating solution suitable for improving the secondary coating of the electrophoretic paint is characterized in that the mass ratio of the vinyl acetate to the butyl acrylate to the acrylic acid to the hydroxyethyl methacrylate to the composite emulsifier to the ammonium persulfate as the initiator is (45-65) to (35-55) to (8-11) to (2-8) to (2-4).
5. The non-oriented silicon steel insulation coating solution suitable for improving the secondary coating of the electrophoretic paint according to claim 1, 3 or 4, wherein the preparation method of the vinyl acetate-acrylic emulsion comprises the following steps:
(1) Dividing monomer vinyl acetate into A and B parts, wherein A is used as a seed emulsion raw material; b, uniformly stirring the mixture with butyl acrylate, acrylic acid and hydroxyethyl methacrylate in a container at the temperature of between 20 and 30 ℃ to obtain a mixed monomer;
(2) Dividing initiator ammonium persulfate into C and D according to the mass ratio of 1: 1-3, wherein C is used as a seed emulsion initiator, and D is used as an initiator for mesochite polymerization of a mixed monomer;
(3) The composite emulsifier is divided into two parts of E and F according to the mass ratio of 1 to (1-3), wherein E is used as a seed emulsion emulsifier, and F is used as an emulsifier for shell polymerization of a mixed monomer;
(4) Adding deionized water and polyvinyl alcohol into a four-neck flask which is filled with a reflux condenser pipe, a stirrer, a thermometer and a feeding device and is protected by nitrogen according to the mass ratio of (8-12) to 1, heating to 85-95 ℃ in a constant-temperature water bath to completely dissolve the polyvinyl alcohol, cooling to 45-55 ℃, adding a composite emulsifier E and acid-base buffer sodium dihydrogen phosphate, adding a part of vinyl acetate A, and stirring and pre-emulsifying for 10-60 min at 30-60 ℃; heating to 60-90 ℃, adding a part of the initiator C, continuing to dropwise add the rest vinyl acetate A and the rest initiator C when the emulsion is in a blue phase, and keeping the temperature at 70-80 ℃ for 30-60 min after all the materials are added to obtain seed emulsion;
(4) And (3) heating the seed emulsion to 80-90 ℃, then uniformly dripping the mixed monomer, the initiator D and the composite emulsifier F into the reactor within 1-2 h, continuously preserving the heat for 60-90 min after all materials are added, and cooling and adjusting the pH value to obtain the vinyl acetate-acrylic emulsion.
6. The non-oriented silicon steel insulation coating solution suitable for improving the secondary coating of the electrophoretic paint according to claim 5, wherein the polyvinyl alcohol is a mixture of model PVA1799 and PVA1788, and the mixing mass ratio of the two is 4:6; the initiator is ammonium persulfate; the composite emulsifier is a mixture of sodium dodecyl benzene sulfonate (SDS) and alkylphenol polyoxyethylene (TX-9), and the mixing mass ratio of the sodium dodecyl benzene sulfonate (SDS) to the alkylphenol polyoxyethylene is 1: 1-3.
7. The non-oriented silicon steel insulating coating liquid suitable for improving the secondary coating of the electrophoretic paint according to claim 1 or 2, characterized in that the rheological agent is polyether modified trisiloxane or polyether modified tetrasiloxane; the polyalcohol is ethylene glycol or glycerol; the film-forming auxiliary agent is one or two of dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether and dipropylene glycol monobutyl ether; the defoaming agent is one or more of polyoxyethylene polyoxypropylene pentaerythritol ether, polyoxyethylene polyoxypropylene amine ether, polyoxypropylene glycerol ether, polyoxypropylene polyoxyethylene glycerol ether and polydimethylsiloxane.
8. The preparation method of the non-oriented silicon steel insulating coating liquid of claim 1 or 2, which is characterized by comprising the following specific steps: sequentially adding deionized water and boric acid into a reaction container, stirring for 180-300 minutes to fully dissolve the boric acid, sequentially adding the vinyl acetate-acrylic emulsion, the film-forming assistant, the rheological agent and the polyol, stirring for 60-90 minutes after each component is added, finally adding the defoaming agent, and stirring for 120-150 minutes; and standing for 20-30 min after the coating liquid is prepared, and filtering residual particles in the coating liquid to obtain the non-oriented silicon steel insulating coating liquid suitable for improving the secondary coating of the electrophoretic paint.
9. The application method of the non-oriented silicon steel insulating coating liquid of claim 1 or 2 is characterized by comprising the following specific steps: adding water into the non-oriented silicon steel insulating coating liquid until the specific gravity is 1.00-1.20, then coating the non-oriented silicon steel insulating coating liquid on the surface of a non-oriented silicon steel plate, and then placing the non-oriented silicon steel insulating coating liquid in a drying furnace for drying and curing at a certain temperature to form an insulating coating; wherein the coating amount of the coating liquid is 0.3-1 mu m; the temperature of the curing plate of the drying curing steel plate substrate is as follows: 240-300 ℃/20-80S.
10. The application method of the non-oriented silicon steel insulating coating solution according to claim 9, wherein the non-oriented silicon steel cold-rolled non-oriented silicon steel sheet is obtained by pickling a non-oriented silicon steel hot-rolled sheet with a thickness of 1.8-2.8 mm and a silicon content of 0.4-3.0% to remove surface iron scale, rolling the steel sheet to a target thickness of 0.35-0.65 mm by a rolling mill, and then continuously annealing.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101906278A (en) * | 2010-08-12 | 2010-12-08 | 华南理工大学 | Single-component polyvinylacetate binding agent and preparation method thereof |
| CN106497274A (en) * | 2016-11-03 | 2017-03-15 | 马鞍山钢铁股份有限公司 | Silicon steel insulating coating, its preparation method and its using method |
| CN109161265A (en) * | 2018-07-17 | 2019-01-08 | 常州工程职业技术学院 | A kind of electric steel insulating paint acrylate and vinyl acetate emulsion and preparation method thereof |
| CN114031997A (en) * | 2021-09-30 | 2022-02-11 | 武汉钢铁有限公司 | Coating liquid suitable for surface coating of non-oriented silicon steel ultrathin strip and preparation method and application thereof |
-
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101906278A (en) * | 2010-08-12 | 2010-12-08 | 华南理工大学 | Single-component polyvinylacetate binding agent and preparation method thereof |
| CN106497274A (en) * | 2016-11-03 | 2017-03-15 | 马鞍山钢铁股份有限公司 | Silicon steel insulating coating, its preparation method and its using method |
| CN109161265A (en) * | 2018-07-17 | 2019-01-08 | 常州工程职业技术学院 | A kind of electric steel insulating paint acrylate and vinyl acetate emulsion and preparation method thereof |
| CN114031997A (en) * | 2021-09-30 | 2022-02-11 | 武汉钢铁有限公司 | Coating liquid suitable for surface coating of non-oriented silicon steel ultrathin strip and preparation method and application thereof |
Non-Patent Citations (1)
| Title |
|---|
| 贾艳飞等: "核壳型醋-丙乳液的制备及性能研究", 粘接 * |
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