Preparation method of anti-corrosion stain-resistant insulating polyurethane finish paint

Abstract

The invention discloses a preparation method of an anti-corrosion stain-resistant insulating polyurethane finish paint, and belongs to the technical field of paints.The finish paint is composed of a main agent and a curing agent, the main agent comprises water-based hydroxyl acrylic resin, titanium dioxide, anti-corrosion filler, stain-resistant auxiliaries, insulating filler and the like, and the curing agent is a polyisocyanate polymer; by optimizing the formula and the process, the product has excellent corrosion resistance, stain resistance and insulating property, and meanwhile, the environment-friendly characteristic of the water-based paint is kept; the finish paint is particularly suitable for coating railway vehicles and locomotive bodies, and can meet the use requirements in special environments.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings, and in particular relates to a method for preparing an anti-corrosion and anti-fouling insulating polyurethane topcoat. Background Art

[0002] Polyurethane coatings are widely used in industrial protection and decoration due to their excellent weather resistance, mechanical properties, and decorative properties. However, existing water-based polyurethane coatings still lack corrosion resistance, stain resistance, and insulation properties, making them difficult to meet the requirements of use in special environments.

[0003] Especially in the field of rail vehicle and locomotive body painting, there is an urgent need for an environmentally friendly polyurethane topcoat that has anti-corrosion, stain resistance and insulation properties. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing an anti-corrosion and stain-resistant insulating polyurethane topcoat in response to the shortcomings of the background technology. By optimizing the formula and process, the product has excellent corrosion resistance, stain resistance and insulation performance, while maintaining the environmental protection characteristics of water-based coatings.

[0005] The present invention adopts the following technical solutions to solve the above technical problems: An anti-corrosion and anti-fouling insulating polyurethane topcoat is composed of a main agent and a curing agent, wherein the main agent comprises (by weight percentage): Water-based hydroxyl acrylic resin: 30-40%; Titanium dioxide: 20-25%; Kaolin: 1-5%; Anti-corrosion filler: 5-10%; Anti-fouling additive: 1-3%; Insulation filler: 3-8%; Propylene glycol methyl ether acetate: 2-3%; Dipropylene glycol diacetate: 8-10%; Other additives: 1-5%; Deionized water: 10-20%; Curing agent composition (weight percentage): Polyisocyanate polymer: 65-70%; Mixed dibasic acid esters: 30-35%.

[0006] As a further preferred embodiment of the anti-corrosion and anti-fouling insulating polyurethane topcoat of the present invention, the anti-corrosion filler is zinc phosphate or modified zinc phosphate, and the particle size is ≤5 μm.

[0007] As a further preferred embodiment of the anti-corrosion and anti-fouling insulating polyurethane topcoat of the present invention, the anti-fouling auxiliary agent is a fluorine-containing surfactant, and the addition amount is 1-3%.

[0008] As a further preferred embodiment of the anti-corrosion and anti-fouling insulating polyurethane topcoat of the present invention, the insulating filler is mica powder or alumina powder with a particle size of ≤10 μm and an addition amount of 3-8%.

[0009] As a further preferred embodiment of the anti-corrosion and anti-fouling insulating polyurethane topcoat of the present invention, the other additives include a defoaming agent, a leveling agent and a wetting agent.

[0010] As a further preferred embodiment of the anti-corrosion and anti-fouling insulating polyurethane topcoat of the present invention, the anti-corrosion and anti-fouling insulating polyurethane topcoat is applied by air spraying or airless spraying during construction, and the viscosity is controlled at 17-25s / T-4.

[0011] As a further preferred embodiment of the anti-corrosion and stain-resistant insulating polyurethane topcoat of the present invention, the construction environment temperature of the anti-corrosion and stain-resistant insulating polyurethane topcoat is 15-35° C. and the humidity is 30-85% RH.

[0012] A preparation method of an anti-corrosion and anti-fouling insulating polyurethane topcoat, comprising three steps of preparing a main agent, preparing a curing agent, and mixing before use; The main agent preparation method specifically comprises the following steps: Step A1, adding water-based hydroxylated acrylic resin into a reaction kettle and stirring at a low speed of 300-500 rpm; Step A2, adding titanium dioxide, kaolin, anti-corrosion filler, and insulating filler in sequence, stirring and dispersing them evenly; Step A3: Add propylene glycol methyl ether acetate, dipropylene glycol diacetate and other additives and continue stirring; Step A4: Finally, add deionized water to adjust the viscosity to 1000-3000 mPa•s; Step A5, grinding to a fineness of ≤10 μm, and then filtering; The method for preparing a curing agent specifically comprises the following steps: Step B1, adding a polyisocyanate polymer into a reaction kettle; Step B2, adding the mixed dibasic acid ester and stirring evenly; Step B3: adjust the viscosity to 1000-3000 mPa•s, and then filter.

[0013] The method of mixing before use specifically comprises the following steps: Step C1, mixing the main agent and the curing agent in a certain weight ratio; Step C2, adding an appropriate amount of water-based paint thinner to adjust the construction viscosity; Step C3: Let it stand for 10 minutes before use.

[0014] As a further preferred embodiment of the method for preparing the anti-corrosion and anti-fouling insulating polyurethane topcoat of the present invention, the mixing ratio of the main agent to the curing agent is 3:1 for high gloss or 5:1 for low gloss (weight ratio).

[0015] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects: A method for preparing an anti-corrosion and anti-fouling insulating polyurethane topcoat, comprising a main agent and a curing agent, wherein the main agent comprises a water-based hydroxy acrylic resin, titanium dioxide, an anti-corrosion filler, an anti-fouling additive and an insulating filler, and the curing agent is a polyisocyanate polymer; the method comprises three steps: preparing the main agent, preparing the curing agent and mixing before use; the method has excellent anti-corrosion performance: by adding a special anti-corrosion filler, the anti-corrosion performance of the coating is significantly improved, and the salt spray test can reach more than 1000 hours; good anti-fouling performance: the addition of a fluorine-containing additive reduces the surface energy of the coating, making it difficult for dirt to adhere Easy to wear and clean; Outstanding insulation performance: The addition of special insulating fillers gives the coating excellent insulation performance, and the volume resistivity can reach above 10^12Ω·cm; Good environmental performance: Water-based system, low VOC content, in line with environmental protection requirements; Excellent construction performance: Moderate viscosity, large spraying area (theoretical 10㎡ / kg, dry film 50μm), wide construction window (15-35℃, 30-85%RH); Excellent comprehensive performance: The coating also has high fullness (gloss ≥8020° angle), good flexibility and weather resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 The present invention is a flow chart of a method for preparing an anti-corrosion and anti-fouling insulating polyurethane topcoat. DETAILED DESCRIPTION

[0018] The technical solution of the present invention is further described in detail below with reference to the accompanying drawings: The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The present invention is described in detail below based on the drawings and preferred embodiments. The purpose and effect of the present invention will become more clear. It should be understood that the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0019] An anti-corrosion and anti-fouling insulating polyurethane topcoat is composed of a main agent and a curing agent, wherein the main agent comprises (by weight percentage): Water-based hydroxyl acrylic resin: 30-40%; Titanium dioxide: 20-25%; Kaolin: 1-5%; Anti-corrosion filler: 5-10%; Anti-fouling additive: 1-3%; Insulation filler: 3-8%; Propylene glycol methyl ether acetate: 2-3%; Dipropylene glycol diacetate: 8-10%; Other additives: 1-5%; Deionized water: 10-20%; Curing agent composition (weight percentage): Polyisocyanate polymer: 65-70%; Mixed dibasic acid esters: 30-35%.

[0020] Preferably, the anti-corrosion filler is zinc phosphate or modified zinc phosphate with a particle size of ≤5μm, the anti-fouling agent is a fluorine-containing surfactant, the addition amount is 1-3%, the insulating filler is mica powder or alumina powder, the particle size is ≤10μm, and the addition amount is 3-8%, the other additives include defoaming agents, leveling agents and wetting agents, and the anti-corrosion and anti-fouling insulating polyurethane topcoat is air sprayed or airless sprayed during construction, and the viscosity is controlled at 17-25s / T-4. The construction environment temperature of the anti-corrosion and anti-fouling insulating polyurethane topcoat is 15-35℃, and the humidity is 30-85%RH.

[0021] A preparation method of an anti-corrosion and anti-fouling insulating polyurethane topcoat, comprising three steps of preparing a main agent, preparing a curing agent, and mixing before use; The main agent preparation method specifically comprises the following steps: Step A1, adding water-based hydroxylated acrylic resin into a reaction kettle and stirring at a low speed of 300-500 rpm; Step A2, adding titanium dioxide, kaolin, anti-corrosion filler, and insulating filler in sequence, stirring and dispersing them evenly; Step A3: Add propylene glycol methyl ether acetate, dipropylene glycol diacetate and other additives and continue stirring; Step A4: Finally, add deionized water to adjust the viscosity to 1000-3000 mPa•s; Step A5, grinding to a fineness of ≤10 μm, and then filtering; The method for preparing a curing agent specifically comprises the following steps: Step B1, adding a polyisocyanate polymer into a reaction kettle; Step B2, adding the mixed dibasic acid ester and stirring evenly; Step B3: adjust the viscosity to 1000-3000 mPa•s, and then filter.

[0022] The method of mixing before use specifically comprises the following steps: Step C1, mixing the main agent and the curing agent in a certain weight ratio; Step C2, adding an appropriate amount of water-based paint thinner to adjust the construction viscosity; Step C3: Let it stand for 10 minutes before use.

[0023] The mixing ratio of the main agent to the curing agent is 3:1 for high gloss or 5:1 for low gloss (by weight).

[0024] The present invention has excellent anti-corrosion performance: by adding special anti-corrosion fillers, the anti-corrosion performance of the coating is significantly improved, and the salt spray test can reach more than 1000 hours; good stain resistance: the addition of fluorine-containing additives reduces the surface energy of the coating, making it difficult for dirt to adhere and easy to clean; outstanding insulation performance: the addition of special insulating fillers gives the coating excellent insulation performance, and the volume resistivity can reach more than 10^12Ω·cm; good environmental performance: the water-based system has a low VOC content and meets environmental protection requirements; excellent construction performance: moderate viscosity, large spraying area (theoretical 10㎡ / kg, dry film 50μm), and wide construction window (15-35℃, 30-85%RH); excellent comprehensive performance: the coating also has high fullness (gloss ≥80 20° angle), good flexibility and weather resistance.

[0025] Example 1: 1. Preparation of main agent: Add 35 kg of water-based hydroxylated acrylic resin into the reactor and start stirring (400 rpm); Add 22kg titanium dioxide, 3kg kaolin, 7kg zinc phosphate, and 5kg mica powder in sequence; Add 2.5 kg of propylene glycol methyl ether acetate, 9 kg of dipropylene glycol diacetate, 2 kg of fluorinated surfactant and 3 kg of other additives; Finally, add 15 kg of deionized water to adjust the viscosity; Grind to a fineness of ≤10μm, filter and package.

[0026] 2. Preparation of curing agent: Add 68 kg of polyisocyanate polymer into the reactor; Add 32kg of mixed dibasic acid ester and stir evenly; Adjust the viscosity to 2000mPa•S (25℃), filter and package.

[0027] 3. Construction application: Mix the main agent and curing agent in a ratio of 3:1, and add appropriate amount of diluent to adjust the viscosity to 20s / T-4; Use air spraying, and control the wet film thickness at 100-120μm; Dry at 25℃, surface drying ≤4h, through drying ≤24h.

[0028] Those skilled in the art will understand that the above descriptions are merely preferred embodiments of the invention and are not intended to limit the invention. Although the invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will still be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the invention shall be included within the scope of protection of the invention. All technical features in this embodiment may be freely combined according to actual needs.

[0029] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An anti-corrosion and anti-fouling insulating polyurethane topcoat, characterized by: It is composed of a main agent and a curing agent, and the main agent composition (weight percentage): Water-based hydroxyl acrylic resin: 30-40%; Titanium dioxide: 20-25%; Kaolin: 1-5%; Anti-corrosion filler: 5-10%; Anti-fouling additive: 1-3%; Insulation filler: 3-8%; Propylene glycol methyl ether acetate: 2-3%; Dipropylene glycol diacetate: 8-10%; Other additives: 1-5%; Deionized water: 10-20%; Curing agent composition (weight percentage): Polyisocyanate polymer: 65-70%; Mixed dibasic acid esters: 30-35%.

2. The anti-corrosion and anti-fouling insulating polyurethane topcoat according to claim 1, characterized in that: The anti-corrosion filler is zinc phosphate or modified zinc phosphate, and the particle size is ≤5 μm.

3. The anti-corrosion and anti-fouling insulating polyurethane topcoat according to claim 1, characterized in that: The anti-fouling agent is a fluorine-containing surfactant, and the addition amount is 1-3%.

4. The anti-corrosion and anti-fouling insulating polyurethane topcoat according to claim 1, characterized in that: The insulating filler is mica powder or alumina powder, with a particle size of ≤10 μm and an addition amount of 3-8%.

5. The anti-corrosion and anti-fouling insulating polyurethane topcoat according to claim 1, characterized in that: The other additives include defoamers, leveling agents and wetting agents.

6. The anti-corrosion and anti-fouling insulating polyurethane topcoat according to claim 1, characterized in that: The anti-corrosion and stain-resistant insulating polyurethane topcoat is applied by air spray or airless spray during construction, and the viscosity is controlled at 17-25s / T-4.

7. The anti-corrosion and anti-fouling insulating polyurethane topcoat according to claim 1, characterized in that: The construction environment temperature of anti-corrosion and stain-resistant insulating polyurethane topcoat is 15-35℃ and the humidity is 30-85%RH.

8. A method for preparing the anti-corrosion and anti-fouling insulating polyurethane topcoat according to any one of claims 1 to 7, characterized in that: It includes three steps: preparation of main agent, preparation of curing agent and mixing before use; The main agent preparation method specifically comprises the following steps: Step A1, adding water-based hydroxylated acrylic resin into a reaction kettle and stirring at a low speed of 300-500 rpm; Step A2, adding titanium dioxide, kaolin, anti-corrosion filler, and insulating filler in sequence, stirring and dispersing them evenly; Step A3: Add propylene glycol methyl ether acetate, dipropylene glycol diacetate and other additives and continue stirring; Step A4: Finally, add deionized water to adjust the viscosity to 1000-3000 mPa•s; Step A5, grinding to a fineness of ≤10 μm, and then filtering; The method for preparing a curing agent specifically comprises the following steps: Step B1, adding a polyisocyanate polymer into a reaction kettle; Step B2, adding the mixed dibasic acid ester and stirring evenly; Step B3, adjusting the viscosity to 1000-3000 mPa•s, and then filtering; The method of mixing before use specifically comprises the following steps: Step C1, mixing the main agent and the curing agent in a certain weight ratio; Step C2, adding an appropriate amount of water-based paint thinner to adjust the construction viscosity; Step C3: Let it stand for 10 minutes before use.

9. The method for preparing an anti-corrosion and anti-fouling insulating polyurethane topcoat according to claim 8, characterized in that: The mixing ratio of the main agent to the curing agent is 3:1 for high gloss or 5:1 for low gloss (by weight).

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