Deep embossing-tolerable primer-topcoat syncretic coating for home appliance panels, and preparation method therefor

Abstract

Disclosed in the present invention are a deep embossing-tolerable primer-topcoat syncretic coating for home appliance panels, and a preparation method therefor. The primer-topcoat syncretic coating comprises the following components by weight: 20-35 parts of a modified polyester resin, 3-10 parts of a polyester resin having a high molecular weight, 6-10 parts of a curing agent, 20-35 parts of a pigment and filler, 0.4-1 part of wax powder, 2-3 parts of an auxiliary agent and 15-30 parts of a mixed solvent, wherein the modified polyester resin is a polyester polyurethane resin, and is prepared by means of an addition polymerization reaction of a polyester polyol resin and a diisocyanate compound. A single coating layer formed by said primer-topcoat syncretic coating exhibits excellent adhesion, machinability, corrosion resistance, and adaptability to different types of base materials, and especially has good tolerance to deep embossing, thereby possessing a broad application prospect in the market of colored coated panels.

Description

A bottom-surface integrated finish for deep-embossed household appliance panel and a preparation method thereof TECHNICAL FIELD

[0001] The present application relates to the technical field of coil coating, in particular to a bottom-surface integrated finish for deep-embossed household appliance panel and a preparation method thereof. BACKGROUND

[0002] At present, with the increasing use of color-coated steel sheets in the household appliance industry, the competition of products is becoming more and more fierce. In order to reduce costs and improve cost performance, some domestic color steel plants reduce the thickness of the steel sheet, use embossing to increase the apparent thickness and strength of the steel sheet, so as to achieve the purpose of reducing costs, while the quality does not decrease. This process is widely used in the processing of household appliance refrigerator side panels, and the requirements for paint coating are also increasing. Not only is the paint film required to have high flexibility, good shear strength, and ensure the integrity and ductility of the paint film under mechanical tensile deformation. Therefore, the paint film is required to have certain strength and strong adhesion.

[0003] The conventional household appliance panel pre-coated coil coating is mostly a multi-coating system. The front surface of the household appliance panel generally adopts a "two-coat two-bake" construction process, that is, a base paint is coated on the front surface of the substrate, and then a topcoat is coated. The traditional "two-coat two-bake" process is not only complicated, high in production cost, energy-wasting, time-consuming and labor-intensive. The bottom-surface integrated finish for deep-embossed household appliance panel with excellent corrosion resistance and decoration, which integrates the bottom paint and the topcoat, can well solve the above problems. Only "one-coat one-bake" process is required during construction, and the paint film prepared has not only the sealing and corrosion resistance of the bottom paint, but also the decoration and external protection functions of the topcoat. It can effectively reduce the construction process flow, reduce costs, greatly shorten the production cycle, and improve the actual production efficiency. However, at present, there is no mature bottom-surface integrated product in the color-coated sheet industry that can meet the above performance requirements after deep embossing. SUMMARY

[0004] In order to solve the above technical problems, the present application provides a bottom-surface integrated finish for deep-embossed household appliance panel and a preparation method thereof. The bottom-surface integrated finish for deep-embossed household appliance panel can greatly improve the deep-embossed performance of the color-coated sheet, so that the embossed color-coated sheet has strong flexibility, surface strength and ductility, and high adhesion.

[0005] In the first aspect, the present application provides a bottom-surface integrated finish for deep-embossed household appliance panel, which is realized by using the following technical scheme.

[0006] A bottom-surface integrated finish for deep-embossed household appliance panel, comprising the following components by weight:

[0007] 20-35 parts of modified polyester resin;

[0008] High molecular weight polyester resin 3-10 parts;

[0009] Curing agent 6-10 parts;

[0010] Color filler 20-35 parts;

[0011] Wax powder 0.4-1 parts;

[0012] Auxiliary 2-3 parts;

[0013] Solvent 15-30 parts;

[0014] The modified polyester resin is a polyester polyurethane resin prepared by reacting a polyester polyol resin and a diisocyanate compound.

[0015] Further, the preparation method of the modified polyester resin comprises the following steps:

[0016] a. Under the action of a catalyst, dihydric alcohol and dihydric acid are subjected to esterification reaction to obtain linear hydroxyl-terminated polyester resin prepolymer;

[0017] b. Under the action of a catalyst, the linear hydroxyl-terminated polyester resin prepolymer prepared in step a and a diisocyanate compound are subjected to addition polymerization reaction to obtain hydroxyl-terminated polyester polyurethane resin.

[0018] Further, in the esterification reaction of step a, the ratio of the number of moles of hydroxyl groups contained in dihydric alcohol to the number of moles of carboxyl groups contained in dihydric acid is 1.2-1.5:1.

[0019] Further, the dihydric acid is selected from one or more mixtures of adipic acid, isophthalic acid, hexahydrophthalic anhydride, 1,4-cyclohexane dicarboxylic acid and 1,2-cyclohexane dicarboxylic acid.

[0020] Further, the dihydric alcohol is selected from one or more mixtures of neopentyl glycol, methylpropanediol, 1,4-cyclohexane dimethanol, 1,2-cyclohexane dimethanol and 3-methyl-1,5-pentanediol.

[0021] Further, the esterification reaction conditions of step a are as follows: the temperature is raised to 140-145°C at a rate of 10-15°C / h for reflux reaction, and then the temperature is kept at 200-205°C for 1-2 hours, and then the temperature is raised to 230-235°C at a rate of 2-3 hours for reaction until the measured acid value is stable.

[0022] Further, the esterification reaction catalyst of step a is monobutyl tin oxide, and the addition amount of the catalyst is 0.03-0.3% of the total reaction material mass of step a.

[0023] Further, the ratio of the number of moles of the hydroxyl groups contained in the linear hydroxyl-terminated polyester resin prepolymer to the number of moles of the isocyanate groups contained in the diisocyanate compound in the addition polymerization reaction of step b is 1:0.7-0.9.

[0024] Further, the diisocyanate compound is selected from one or a combination of several of aromatic diisocyanates and alicyclic diisocyanates.

[0025] Specifically, the diisocyanate compound is selected from one or a combination of several of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate.

[0026] The addition polymerization reaction conditions of step b are as follows: temperature is raised to 50-60°C in 1-2 hours, then raised to 65-70°C for 2-3 hours, and then raised to 70-80°C for reaction until the NCO content of the system is ≤5 mg NCO / g.

[0027] Further, the catalyst for the addition polymerization reaction of step b is dibutyltin dilaurate, and the amount of the catalyst added is 0.1-0.2% of the total mass of the reaction materials of step b.

[0028] Further, the high molecular weight polyester resin is a linear structure saturated polyester resin with terminal hydroxyl functional groups, and has an acid value of 0-8 mg KOH / g, a number average molecular weight of 10,000-20,000, and a hydroxyl value of 2-10 mg KOH / g.

[0029] Specifically, the high molecular weight polyester resin can be selected from at least one of the following commercially available types: CH550, CH470, CH541, and CH460 (Haohai New Materials Co., Ltd.); ES160, ES410, ES420, and ES450 (SK Corporation, Korea).

[0030] Further, the curing agent is a combination of blocked polyisocyanate resin and amino resin, and the mass ratio of the blocked polyisocyanate resin to the curing agent is 5:95-20:80.

[0031] Specifically, the amino resin is a fully methylolated amino resin, such as the commercially available resin products of CYMEL 303 (Cytec) and Resimene-747 (Sunoco); and the blocked polyisocyanate resin is a trimer isocyanate, which can be selected from DESMODUR BL3175 (Bayer) and B1358 (Evonik) or similar commercially available blocked isocyanate resins.

[0032] Further, the pigment and filler is selected from one or a combination of several of titanium dioxide, carbon black, red iron oxide, and yellow iron oxide.

[0033] Further, the color filler further comprises an environmentally friendly anti-rust pigment of polyphosphate SRPP and calcium ion exchange pigment MS780, the addition amount of the environmentally friendly anti-rust pigment is 4.5-5.5wt% of the total paint, and the mass ratio of polyphosphate SRPP and calcium ion exchange pigment MS780 is 1:5-1:3.

[0034] Further, the wax powder is at least one of polytetrafluoroethylene wax, fluorine-modified polyethylene wax, and fluorine-modified synthetic wax.

[0035] Specifically, the wax powder is at least one of Fluo HT, Synfluo178XF, and Synfluo180XF of the American Micro Powder Company.

[0036] Further, the auxiliary agent is at least one of a dispersing agent and a defoaming agent, a leveling agent, an adhesion promoter, and a curing catalyst.

[0037] Further, the dispersing agent is at least one of AFCONA-4010, AFCONA-4017, AFCONA-4060, AFCONA-4070, and AFCONA-4080 of the AFCONA Company.

[0038] Further, the defoaming agent is a non-silicon system defoaming agent, and is at least one of BYK-054, BYK352, BYK-057, and BYK-1795 of the BYK Company.

[0039] Further, the leveling agent is a non-silicon system leveling agent, and is at least one of AFCONA-3700, AFCONA-3750, AFCONA-3773, AFCONA-3775, AFCONA-3777, and AFCONA-3779 of the AFCONA Company.

[0040] Further, the adhesion promoter is a phosphate-modified polymer, and is at least one of Lubrizol 2063, Tech-7205, and ADP.

[0041] Further, the curing catalyst comprises an acid catalyst, and is at least one of NACURE 1051, NACURE 2500, and NACURE 5225 of the American King Company.

[0042] Further, the solvent is at least one of butanol, propylene glycol methyl ether acetate, cyclohexanone, S-100# aromatic hydrocarbon solvent, S-150# aromatic hydrocarbon solvent, and divalent acid ester DBE.

[0043] In a second aspect, the application provides a preparation method of a bottom-surface integrated finish paint for deep-embossed household appliance panels.

[0044] The preparation method of the bottom-surface integrated finish paint for deep-embossed household appliance panels comprises the following steps:

[0045] S1. Mix modified polyester resin, dispersants in additives, pigments and fillers, and wax powder in an amount of 30-50% of the total mass of the modified polyester resin, and then add solvents in an amount of 30-50% of the total mass of the solvents, and grind to obtain a slurry, wherein the sanding is performed to less than 15 microns;

[0046] S2. Add the remaining modified polyester resin, high-molecular-weight polyester resin, and the remaining additives except for the dispersants to the slurry, and then add a curing agent and the remaining solvents, mix, and then filter to obtain the bottom-surface integrated finish paint for deep-embossed household appliance panels.

[0047] The application has the following beneficial effects.

[0048] 1. The application modifies the high-molecular-chain polyester resin, i.e., performs addition polymerization reaction on linear hydroxyl-terminated polyester resin prepolymers and diisocyanate compounds to synthesize polyester polyurethane resin, and the modified polyester resin contains a certain amount of urethane bonds, which not only makes the coating have excellent flexibility and adhesion, but also is superior to ester bonds in terms of hydrolysis stability, salt mist resistance, acid resistance, and the like;

[0049] 2. The application performs addition polymerization reaction on linear hydroxyl-terminated polyester resin prepolymers and diisocyanate compounds to obtain polyester polyurethane resin, changes the types of dihydric alcohols, diacids, and diisocyanate compounds, and thus obtains resins with different molecular structures and properties, realizes the adjustability of the molecular structure, and finally obtains deep-embossed household appliance panels with different functions.

[0050] 3. The bottom-surface integrated finish paint for deep-embossed household appliance panels provided by the application integrates the primer and the finish paint, and only needs the “one-coat-one-baking” process during construction, which greatly shortens the production cycle and improves the actual production efficiency. Compared with the traditional “two-coat-two-baking” process, the energy consumption for curing is reduced by 40%-50%, and the energy saving and consumption reduction are remarkable.

[0051] 4. The bottom-surface integrated finish paint prepared by the application can be widely applied to deep-embossed household appliance panels in coil coating, especially to the side panels of household refrigerators, overcomes the deficiencies of the finish paint in the prior art in terms of deep-embossed resistance, endows the coating with excellent embossed MEK resistance, and improves the adhesion and machinability of the coating.

[0052] 5. The preparation method of the polyester finish paint is simple, meets the production requirements of green environmental protection, and is easy to mass produce. DETAILED DESCRIPTION

[0053] The present patent application is further illustrated in conjunction with the following examples.

[0054] The experimental methods used in the following preparation examples and examples are conventional methods unless otherwise specified; the materials, reagents, etc. used in the following preparation examples and examples are commercially available unless otherwise specified.

[0055] Preparation Example

[0056] Preparation of modified polyester resin

[0057] The preparation methods of modified polyester resins A to Q in Table 1 are as follows (modified polyester resins P and Q are both adjustments based on modified polyester resin M):

[0058] (1) A clean reaction bottle equipped with a stirrer, a thermometer, a water separator, a condenser, and an inert gas inlet was charged with a dihydric alcohol (I in Table 1), a dihydric acid (II in Table 1), monobutyl tin oxide 0.25 g, and dimethylbenzene 80 g. The mixture was heated to 140°C at a rate of 10°C / h under continuous stirring and protection of an inert atmosphere, and then reacted for 1 h. The temperature was then increased to 200°C, and the reaction was continued for 2 h. The temperature was then increased to 230°C, and the reaction was continued until the acid value of the reaction system was stable. The reaction system was then cooled to obtain a linear polyester resin with terminal hydroxyl groups;

[0059] (2) A diisocyanate compound (see III in Table 1 for details), dibutyltin dilaurate 0.5 g, and dimethylbenzene 80 g were added. The temperature was then increased to 60°C at a slow rate, and the reaction was continued for 1 h. The temperature was then increased to 70°C, and the reaction was continued for 1 h. The temperature was then increased to 80°C, and the reaction was continued until the NCO% of the system was about 0 (the reaction end point was determined by the method of hexachloropyridine-chlorobenzene titration using bromocresol green as an indicator). The reaction system was then cooled, and the obtained filtrate was the modified polyester resin.

[0060] The specific selection of each reactant is shown in Table 1:

[0061] Table 1

[0062] Example

[0063] Based on each modified polyester resin in Table 1, a bottom-surface-in-one finish for deep-embossed household appliance panels was prepared. The specific amounts of each raw material are shown in Table 2, and the preparation process is as follows:

[0064] Step (1): 30-50% of the modified polyester resin, a dispersant, pigments and fillers, and wax powder were mixed, and then 30-50% of a solvent was added. The mixture was ground to obtain a slurry, and the sanding was performed to less than 15 μm.

[0065] Step (2): the remaining modified polyester resin, high molecular weight polyester resin, the remaining additives except dispersant were added into the slurry obtained in step (1) and mixed; then the curing agent and the remaining solvent were added and mixed, and then filtered to obtain the bottom-surface integrated paint for deep-embossed household appliance plate.

[0066] Table 2: Material input conditions in step (1) and step (2) of examples 1-40

[0067] It should be noted that Comparative Example 1 was modified on the basis of Example 9 by adjusting the modified polyester resin, and the other components were unchanged. Specifically, during the synthesis of the modified polyester resin, no aromatic diisocyanate and alicyclic diisocyanate was contained, and an aliphatic isocyanate was used. Comparative Example 2 was modified on the basis of Example 9 by adjusting the modified polyester resin, and the other components were unchanged. Specifically, during the synthesis of the modified polyester resin, no isocyanate was contained. Comparative Example 3 was modified on the basis of Example 27 by adjusting the curing agent, and the other components were unchanged. Specifically, the curing agent was only amino resin. Comparative Example 4 was modified on the basis of Example 27 by adjusting the curing agent, and the other components were unchanged. Specifically, the curing agent was only blocked polyisocyanate resin. Comparative Example 5 was modified on the basis of Example 28 by adjusting the anti-rust filler, and the other components were unchanged. Specifically, the anti-rust filler only contained polyphosphate SRPP. Comparative Example 6 was modified on the basis of Example 28 by adjusting the anti-rust filler, and the other components were unchanged. Specifically, the anti-rust filler only contained calcium ion exchange pigment MS780. Comparative Example 7 was modified on the basis of Example 28 by adjusting the high molecular weight polyester resin, and the other components were unchanged. Specifically, the high molecular weight polyester resin used resin C1223 was a linear saturated polyester resin (number average molecular weight less than 10000) produced by Haohai New Materials.

[0068] Performance detection

[0069] Coating and plate making process:

[0070] Coating and plate making: the obtained bottom-surface integrated paint for deep-embossed household appliance plate was applied on the pretreated galvanized steel plate by wire bar coating, and baked in a 300℃ oven for 40s, the metal plate temperature PMT was 224℃, to obtain a bottom-surface integrated paint film with a thickness of 12-15μm.

[0071] Embossed plate sample preparation: the prepared sample plate was placed in an embossing machine bed to prepare a sample plate with an embossing depth of 70-80μm.

[0072] The bottom-surface integrated coating of the deep-embossing-resistant household appliance panel bottom-surface integrated finish of Examples 1-30 formed by the above operation meets the quality standards, and the quality standards and results are shown in Table 3:

[0073] Table 3

[0074] Note: The resistance to rubbing experiment is a relative displacement experiment, which simulates the force of relative displacement of the color-coated coil and the back-coated plate during transportation. The method is to select a common finish plate and tightly attach it to the back-coated plate, 50°C, 10kg force, and rub the finish plate and the back-coated plate (evaluation criteria: no paint falling, slight paint falling, paint falling, and severe paint falling).

[0075] Other properties not listed in the application table can be achieved as known by those skilled in the art.

[0076] The performance test results of the bottom-surface integrated coating of the deep-embossing-resistant household appliance panel bottom-surface integrated finish of Comparative Examples 1-7 formed by the above operation are shown in Table 4:

[0077] Table 4

[0078] From the experimental results of Table 3 and Table 4, it can be seen that:

[0079] (1) The household appliance panel bottom-surface integrated finish prepared by the present application is suitable for the surface of hot-dipped galvanized steel plate, electroplated zinc steel plate, cold-rolled steel plate, zinc-aluminum-magnesium steel plate, and aluminum-zinc-coated steel plate substrate. The coil primer and topcoat are combined into one, and only "one coating and one baking" process is required for roll coating, which greatly shortens the production cycle and improves the actual production efficiency. Compared with the traditional "two-coating and two-baking" process, the energy consumption for curing is reduced by 40%-50%, which is significant in energy saving and consumption reduction. It can be widely used in deep-embossing-resistant household appliance panels, especially household appliance refrigerator side panels, overcoming the deficiencies of the prior art topcoat in deep-embossing resistance, and endowing the coating with excellent embossing resistance to MEK, and also improving the adhesion and machinability of the coating, which meets the development trend of color-coated panel industry and has a broad market and application prospect.

[0080] (2) The modified polyester resin in Comparative Example 1 does not contain aromatic diisocyanate and alicyclic diisocyanate, and uses aliphatic isocyanate, which does not contain rigid and hard structures of aromatic (benzene ring) and alicyclic (alicyclic) isocyanate, and the adhesion to the metal substrate is not enough, resulting in poor mechanical properties of the embossed plate.

[0081] (3) The modified polyester resin in Comparative Example 2 does not contain isocyanate, so the molecular weight of the finally synthesized modified polyester resin is small, the hydroxyl value is large, and it does not contain urethane bond, the coating resistance is poor, and the adhesion is weak.

[0082] (4) In Comparative Example 3, the curing agent only contains amino resin, compared with Example 27, the coating is hard, the flexibility is poor, and the adhesion is weak.

[0083] (5) In Comparative Example 4, the curing agent only contains blocked polyisocyanate resin, the paint film is soft, the crosslinking degree is not enough, the hardness is not enough, but the resistance is better.

[0084] (6) In Comparative Example 5, the rust-proof filler only contains polyphosphate SRPP; in Comparative Example 6, the rust-proof filler only contains calcium ion exchange pigment MS780. The calcium ion exchange silica gel can intercept the corrosive ions entering the coating on the surface of the silica, exchange with the calcium ions adsorbed on the surface of the silica gel, and release the calcium ions to the metal coating interface to form a dense and impermeable calcium ion layer, which can protect the substrate from corrosion; the phosphate rust-proof pigment can be dissociated into triphosphate ions with strong complexing ability when water penetrates into the coating, which reacts with iron ions to form a complex protective film mainly composed of iron triphosphate. This phosphate protective film is difficult to dissolve in water, has high hardness, and has strong adhesion to the metal substrate, which can effectively prevent the further progress of the corrosion reaction and achieve excellent corrosion protection effect, but pure calcium ion exchange pigment or polyphosphate cannot exert the maximum salt spray resistance, and the two different types of rust-proof fillers need to be compounded to produce a synergistic effect.

[0085] (7) In Comparative Example 7, the base resin does not contain high molecular weight polyester resin, the higher the relative molecular mass of the polyester resin in the coil coating system, the stronger the adhesion of the coating to the metal substrate, so the adhesion of the coating in this comparative example is poor.

[0086] The examples of the specific embodiment are the preferred embodiments of the present application, but do not limit the protection scope of the present application, so: any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A one-coat finish for deep embossed household panels, characterized in that: The components include the following weight parts: Modified polyester resin 20-35 parts; High molecular weight polyester resin 3-10 parts; Curing agent 6-10 parts; Color filler 20-35 parts; Wax powder 0.4-1 part; Auxiliary agent 2-3 parts; Solvent 15-30 parts; The modified polyester resin is a polyester polyurethane resin prepared by reacting a polyester polyol resin and a diisocyanate compound.

2. A one-coat finish for deep embossed household appliance panels according to claim 1, characterized in that: The preparation method of the modified polyester resin includes the following steps: a. Under the action of a catalyst, dihydric alcohol and dihydric acid are subjected to esterification reaction to obtain a linear hydroxyl-terminated polyester resin prepolymer; b. Under the action of a catalyst, the linear hydroxyl-terminated polyester resin prepolymer obtained in step a and a diisocyanate compound are subjected to addition polymerization reaction to obtain a hydroxyl-terminated polyester polyurethane resin.

3. A one-coat finish for deep embossed household appliance panels according to claim 2, characterized in that: In the esterification reaction of step a, the ratio of the number of moles of hydroxyl groups contained in the dihydric alcohol to the number of moles of carboxyl groups contained in the dihydric acid is 1.2-1.5:

1.

4. A one-coat finish for deep embossed household appliance panels according to claim 2, characterized in that: In the addition polymerization reaction of step b, the ratio of the number of moles of hydroxyl groups contained in the linear hydroxyl-terminated polyester resin prepolymer to the number of moles of isocyanate groups contained in the diisocyanate compound is 1:0.7-0.

9.

5. The one-coat finish for deep embossed household appliance panels according to claim 1 or 2, characterized in that: The diisocyanate compound is selected from one or a combination of aromatic diisocyanates and alicyclic diisocyanates.

6. A one-coat finish for deep embossed household appliance panels according to claim 2, characterized in that: The esterification reaction conditions of step a are as follows: the temperature is raised to 140-145°C at a rate of 10-15°C / h for reflux reaction, the temperature is kept at 200-205°C for 1-2 h, and then the temperature is raised to 230-235°C at a rate of 2-3 h for reaction until the measured acid value is stable; the addition polymerization reaction conditions of step b are as follows: the temperature is raised to 50-60°C at a rate of 1-2 h for reaction for 1-2 h, then the temperature is raised to 65-70°C for reaction for 2-3 h, and then the temperature is raised to 70-80°C for reaction until the measured NCO is ≤5 mg NCO / g.

7. A one-coat finish for deep embossed household appliance panels according to claim 1, characterized in that: The high molecular weight polyester resin is a linear structure saturated polyester resin with a terminal hydroxyl functional group, the acid value of which is 0-8 mg KOH / g, the number average molecular weight of which is 10000-20000, and the hydroxyl value of which is 2-10 mg KOH / g.

8. A one-coat finish for deep embossed household appliance panels according to claim 1, characterized in that: The curing agent is a combination of blocked polyisocyanate resin and amino resin, and the mass ratio of the blocked polyisocyanate resin to the curing agent is 5:95-20:

80.

9. A one-coat finish for deep embossed household appliance panels according to claim 1, characterized in that: The color filler is selected from one or a combination of titanium dioxide, carbon black, red iron oxide, and yellow iron oxide; the color filler further includes environmentally friendly anti-rust pigments of polyphosphate SRPP and calcium ion exchange type pigment MS780, the addition amount of the environmentally friendly anti-rust pigments is 4.5-5.5 wt% of the total paint amount, and the mass ratio of polyphosphate SRPP to calcium ion exchange type pigment MS780 is 1:5-1:

3.

10. A process for the preparation of a one-coat finish for deep embossed household appliance panels according to any one of claims 1 to 9, characterized in that: The method includes the following steps: S1. Mix the modified polyester resin, the dispersant in the auxiliary agent, the color filler, and the wax powder in an amount of 30-50% of the total mass of the modified polyester resin, and then add a solvent in an amount of 30-50% of the total mass of the solvent to obtain a slurry, wherein sand milling is performed to 15 μm or less; S2. To the slurry, add the remaining modified polyester resin, high molecular weight polyester resin, and the remaining additives except dispersant, mix; then add the curing agent and the remaining solvent, mix and filter to obtain the one-coat finish for deep-embossed household appliance panels.

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