High and low temperature resistant water-based strippable protective coating and preparation method thereof

Abstract

The application provides a high and low temperature resistant water-based strippable protective coating and a preparation method thereof, and relates to the technical field of coating preparation.The high and low temperature resistant water-based strippable protective coating comprises the following components in parts by weight: 30-50 parts of polyurethane emulsion, 20-30 parts of epoxy resin, 20-30 parts of acrylic emulsion, 10-15 parts of polytetrafluoroethylene, 20-30 parts of filler, 10-20 parts of additive, and the balance of water.The application uses polyurethane emulsion, epoxy resin and acrylic emulsion as main film-forming substances, realizes the stable performance of the coating in a wide temperature range through scientific proportioning and process optimization.The polyurethane emulsion endows the coating with good flexibility and wear resistance, the epoxy resin improves the hardness and adhesion of the coating, and the acrylic emulsion enhances the weather resistance and water resistance of the coating.The synergistic effect of the three substances enables the coating to maintain stable physical and chemical properties in an extreme high or low temperature environment, is not prone to blistering and wrinkling, and is easy to strip.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of paint preparation, in particular to a high and low temperature resistant water-based strippable protective paint and a preparation method thereof. BACKGROUND

[0002] Strippable paint is a functional special paint for temporary protection of the surface of a substrate. During the construction of large ships, the construction period is long, and it is inevitable to be contaminated by dust, rainwater, oil stains, welding slag, iron filings and the like, increasing the subsequent maintenance cost, wasting manpower, material resources and financial resources. The traditional solution is to wrap the surface of the protected object with canvas or aluminum foil paper, but the temporary protection effect is not ideal, and there is still a problem of heavy workload in subsequent cleaning and repair. At present, more and more strippable paint schemes are used for temporary protection. The construction period of large ships is generally more than one year, and the adhesion between the strippable paint and the organic primer increases with time, so the strippable paint needs to have complete strippable performance for more than one year. Because the general water-based strippable paint is formed by a thermoplastic resin, it has poor water resistance and is prone to blistering, wrinkling and even peeling when it comes into contact with rainwater, so the water resistance needs to be improved. In the actual use process, a large time span needs to be experienced, including hot summer and cold winter. Under high temperature conditions, the thermoplastic water-based strippable paint becomes soft, and even when the temperature is higher than the glass transition temperature of the paint, the strength of the paint film is low, the performance is poor, and the stripping process is prone to breakage. In cold winter, especially in the north, below zero, the brittleness of part of the paint film increases, and it has no ductility and completely no strippable performance.

[0003] In many industrial fields, various equipment, workpieces and the like often need to be protected to prevent them from being eroded and worn by the external environment. Traditional protective paint often has deficiencies in terms of high and low temperature resistance, and is difficult to strip after use, which brings great difficulty to subsequent maintenance and cleaning. Therefore, it is of great practical significance to develop a high and low temperature resistant, water-based strippable protective paint. SUMMARY

[0004] (I) Technical problems to be solved

[0005] In view of the deficiencies of the prior art, the present application provides a high and low temperature resistant water-based strippable protective paint and a preparation method thereof, which solves the problems raised in the background art.

[0006] (II) Technical solutions

[0007] To achieve the above object, the present application is implemented by the following technical solutions: a high and low temperature resistant water-based strippable protective paint, comprising the following components by weight: polyurethane emulsion 30-50 parts, epoxy resin 20-30 parts, acrylic emulsion 20-30 parts, polytetrafluoroethylene 10-15 parts, filler 20-30 parts, additive 10-20 parts, and water in excess.

[0008] Preferably, the high and low temperature resistant water-based strippable protective coating comprises the following components by weight: 40 parts of polyurethane emulsion, 25 parts of epoxy resin, 25 parts of acrylic emulsion, 13 parts of polytetrafluoroethylene, 25 parts of filler, 15 parts of auxiliary agent, and the balance of water.

[0009] Preferably, the filler comprises the following components by weight: 4-6 parts of carbon fiber, 4-6 parts of talcum powder, 4-6 parts of mica powder, 4-6 parts of bentonite, and 4-6 parts of quartz powder.

[0010] Preferably, the auxiliary agent comprises the following components by weight: 2-4 parts of plasticizer, 2-4 parts of dispersing agent, 2-4 parts of defoaming agent, 2-4 parts of leveling agent, and 2-4 parts of film-forming aid.

[0011] Preferably, the plasticizer is dioctyl phthalate, the dispersing agent is sodium polyacrylate, the defoaming agent is polyether siloxane copolymer, the leveling agent is polyether modified siloxane, and the film-forming aid is any one or more of dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, and tripropylene glycol n-butyl ether.

[0012] The application further discloses a preparation method of the high and low temperature resistant water-based strippable protective coating.

[0013] Step one: mix the polyurethane emulsion, the epoxy resin, the acrylic emulsion, the polytetrafluoroethylene and water, and stir uniformly to obtain a mixed liquid A;

[0014] Step two: add the filler to the mixed liquid A, and continue to stir until uniformly dispersed to obtain a mixed liquid B;

[0015] Step three: add the auxiliary agent and the pH regulator to the mixed liquid B, and stir fully to obtain a mixed liquid C;

[0016] Step four: filter the final mixed liquid C to obtain the finished protective coating.

[0017] Preferably, in steps one to three, the stirring speed is 500-1500 rpm, and the stirring time is 30-60 min.

[0018] Preferably, in step two, the feeding time of each filler is 1-3 min, after feeding, stirring for 5-10 min, then feeding the next kind of filler, and after feeding all the fillers, stirring at a speed of 1200-1500 rpm for 20-30 min.

[0019] Preferably, in step three, the feeding time of each auxiliary agent is 1-3 min, after feeding, stirring for 5-10 min, then feeding the next kind of auxiliary agent, and after feeding all the auxiliary agents, stirring at a speed of 1200-1500 rpm for 20-30 min.

[0020] Preferably, in step three, the pH regulator is added to the pH of the mixed solution C is 7.3-7.8.

[0021] (III) Beneficial effects

[0022] The application provides a high and low temperature resistant water-based strippable protective coating and a preparation method thereof, and has the following beneficial effects:

[0023] 1. The high and low temperature resistant water-based strippable protective coating uses polyurethane emulsion, epoxy resin and acrylic emulsion as main film-forming substances, realizes stable performance of the coating in a wide temperature range through scientific proportioning and process optimization, and has good flexibility and wear resistance due to the polyurethane emulsion, has improved hardness and adhesion due to the epoxy resin, and has improved weather resistance and water resistance due to the acrylic emulsion. The synergistic effect of the three substances enables the coating to maintain stable physical and chemical properties in an extremely high or low temperature environment, is not prone to foaming and wrinkling, and is easy to strip.

[0024] 2. The coating also contains polytetrafluoroethylene, which has extremely low surface energy, so that the coating can form a smooth film after coating, and further improves the water resistance and chemical medium resistance of the coating. Meanwhile, the addition of polytetrafluoroethylene also endows the coating with excellent self-cleaning performance, which can effectively resist the adhesion of dust, oil stains and other pollutants, and reduce the subsequent cleaning workload.

[0025] 3. In the selection of fillers, the application uses carbon fibers, talc powder, mica powder, bentonite and quartz powder and other inorganic materials. These materials not only have excellent physical and chemical stability, but also can enhance the mechanical strength and wear resistance of the coating. Through reasonable proportioning and dispersion process, these fillers can be uniformly dispersed in the coating to form a dense coating structure and improve the overall performance of the coating.

[0026] 4. Regarding the addition of additives, this invention selects a variety of functional additives such as plasticizers, dispersants, defoamers, leveling agents, and film-forming aids. Each additive plays a unique role, collectively improving the overall performance of the coating. The addition of plasticizers such as dioctyl phthalate effectively improves the flexibility and extensibility of the coating, making it less prone to softening at high temperatures and less prone to embrittlement at low temperatures, ensuring the coating's peelability. Dispersants such as sodium polyacrylate help various pigments and fillers disperse evenly in the coating, avoiding agglomeration and improving the coating's smoothness and aesthetics. The use of defoamers such as polyether siloxane copolymers effectively eliminates bubbles generated during coating preparation and application, ensuring the coating's density and adhesion. Leveling agents such as polyether-modified siloxanes promote the flow and spreading of the coating, making the coating more uniform and smooth, improving the overall aesthetics of the coating. Film-forming aids such as dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, and tripropylene glycol n-butyl ether promote the film-forming process of the coating, improve the hardness and wear resistance of the coating, and also help the coating dry and cure. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the preparation method of the present invention. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1:

[0030] This invention provides a high and low temperature resistant water-based peelable protective coating, comprising the following components by weight: 30 parts polyurethane emulsion, 20 parts epoxy resin, 20 parts acrylic emulsion, 10 parts polytetrafluoroethylene, 20 parts filler, 10 parts additives, and water as the balance.

[0031] The filler comprises the following components by weight: 4 parts carbon fiber, 4 parts talc powder, 4 parts mica powder, 4 parts bentonite, and 4 parts quartz powder.

[0032] Secondly, the additives include the following components by weight: 2 parts plasticizer, 2 parts dispersant, 2 parts defoamer, 2 parts leveling agent, and 2 parts film-forming aid; specifically, the plasticizer is dioctyl phthalate, the dispersant is sodium polyacrylate, the defoamer is polyether siloxane copolymer, the leveling agent is polyether modified siloxane, and the film-forming aid is dipropylene glycol monomethyl ether.

[0033] like Figure 1As shown in the figure, this invention also provides a method for preparing a high and low temperature resistant water-based peelable protective coating, comprising the following steps:

[0034] Step 1: Mix polyurethane emulsion, epoxy resin, acrylic emulsion, polytetrafluoroethylene and water, stir evenly, the stirring speed is 500 rpm and the stirring time is 30 min, to obtain mixture A;

[0035] Step 2: Add filler to the above mixture A. The addition time for each filler is 1 minute. After adding all fillers, stir for 5 minutes before adding the next filler. After adding all fillers, stir at 1200 rpm for 20 minutes and continue stirring until uniformly dispersed to obtain mixture B.

[0036] Step 3: Add the additives and pH adjuster to the above mixture B. Each additive is added over 1 minute. After adding all the additives, stir for 5 minutes before adding the next additive. After adding all the additives, stir at 1200 rpm for 20 minutes. Add the pH adjuster until the pH of the mixture C is 7.3 to obtain mixture C.

[0037] Step 4: Filter the final mixture C to obtain the finished protective coating.

[0038] Example 2:

[0039] This invention provides a high and low temperature resistant water-based peelable protective coating, comprising the following components by weight: 40 parts polyurethane emulsion, 25 parts epoxy resin, 25 parts acrylic emulsion, 13 parts polytetrafluoroethylene, 25 parts filler, 15 parts additives, and water as the balance.

[0040] The filler comprises the following components by weight: 5 parts carbon fiber, 5 parts talc powder, 5 parts mica powder, 5 parts bentonite, and 5 parts quartz powder.

[0041] Secondly, the additives include the following components by weight: 3 parts plasticizer, 3 parts dispersant, 3 parts defoamer, 3 parts leveling agent, and 3 parts film-forming aid; specifically, the plasticizer is dioctyl phthalate, the dispersant is sodium polyacrylate, the defoamer is polyether siloxane copolymer, the leveling agent is polyether modified siloxane, and the film-forming aid is dipropylene glycol monopropyl ether.

[0042] like Figure 1 As shown in the figure, this invention also provides a method for preparing a high and low temperature resistant water-based peelable protective coating, comprising the following steps:

[0043] Step 1: Mix polyurethane emulsion, epoxy resin, acrylic emulsion, polytetrafluoroethylene and water, stir evenly, the stirring speed is 1000 rpm and the stirring time is 45 min, to obtain mixture A.

[0044] Step two: add fillers to the above mixed solution A, the feeding time of each filler is 2 min, after adding, stir for 8 min, then add the next filler, after adding all fillers, stir for 25 min at the speed of 1400 rpm, continue to stir until uniformly dispersed, to obtain mixed solution B;

[0045] Step three: add auxiliary agents and pH adjusters to the above mixed solution B, the feeding time of each auxiliary agent is 2 min, after adding, stir for 8 min, then add the next auxiliary agent, after adding all auxiliary agents, stir for 25 min at the speed of 1400 rpm, add pH adjuster until the pH of mixed solution C is 7.5, to obtain mixed solution C;

[0046] Step four: filter the final mixed solution C, to obtain the finished protective coating.

[0047] Example three:

[0048] The embodiment of the present application provides a kind of high and low temperature resistant water-based strippable protective coating, including the following weight components: polyurethane emulsion 50 parts, epoxy resin 30 parts, acrylic emulsion 30 parts, polytetrafluoroethylene 15 parts, filler 30 parts, auxiliary agent 20 parts, water balance.

[0049] Wherein, filler includes the following weight components: carbon fiber 6 parts, talcum powder 6 parts, mica powder 6 parts, bentonite 6 parts, quartz powder 6 parts.

[0050] Secondly, auxiliary agent includes the following weight components: plasticizer 4 parts, dispersing agent 4 parts, defoaming agent 4 parts, leveling agent 4 parts, film-forming aid 4 parts;Specifically, plasticizer is dioctyl phthalate, dispersing agent is sodium polyacrylate, defoaming agent is polyether siloxane copolymer, leveling agent is polyether modified siloxane, film-forming aid is tripropylene glycol n-butyl ether.

[0051] As Figure 1 shown, the embodiment of the present application also provides a kind of high and low temperature resistant water-based strippable protective coating preparation method, including the following steps:

[0052] Step one: mix polyurethane emulsion, epoxy resin, acrylic emulsion, polytetrafluoroethylene and water, stir uniformly, the stirring speed of stirring is 1500 rpm, and the stirring time is 60 min, to obtain mixed solution A;

[0053] Step two: add fillers to the above mixed solution A, the feeding time of each filler is 3 min, after adding, stir for 10 min, then add the next filler, after adding all fillers, stir for 30 min at the speed of 1500 rpm, continue to stir until uniformly dispersed, to obtain mixed solution B;

[0054] Step three: add the auxiliary agent and pH regulator to the above mixed solution B, the feeding time of each auxiliary agent is 3 min, after adding, stir for 10 min before adding the next auxiliary agent, after adding all the auxiliary agents, stir at 1500 rpm for 30 min, add the pH regulator to the pH of the mixed solution C is 7.8, to obtain the mixed solution C;

[0055] Step four: filter the final mixed solution C to obtain the finished protective coating.

[0056] Comparative example:

[0057] A high and low temperature resistant water-based strippable protective coating, comprising the following components by weight: polyurethane emulsion 30 parts, epoxy resin 20 parts, filler 10 parts, auxiliary agent 4 parts, water balance.

[0058] Among them, the filler includes the following components by weight: carbon fiber 5 parts, talc 5 parts.

[0059] Secondly, the auxiliary agent includes the following components by weight: plasticizer 2 parts, dispersant 2 parts; specifically, the plasticizer is dioctyl phthalate, and the dispersant is sodium polyacrylate.

[0060] The preparation method of the high and low temperature resistant water-based strippable protective coating, comprising the following steps:

[0061] Step one: mix polyurethane emulsion, epoxy resin and water, stir uniformly, the stirring speed of stirring is 500 rpm, the stirring time is 30 min, to obtain mixed solution A;

[0062] Step two: add the filler to the above mixed solution A, stir at 1200 rpm for 20 min, continue to stir until uniformly dispersed, to obtain mixed solution B;

[0063] Step three: add the auxiliary agent and pH regulator to the above mixed solution B, stir at 1200 rpm for 20 min, add the pH regulator to the pH of the mixed solution C is 7.3, to obtain mixed solution C;

[0064] Step four: filter the final mixed solution C to obtain the finished protective coating.

[0065] Experimental example:

[0066] The protective coatings prepared in examples one, two, three and comparative example were tested for strippable performance, and the results are as follows:

[0067] Example Peelability at -20°C for 30 days Peelability at 30°C for 30 days Peelability at 60°C for 30 days Example 1 Complete peel without residue Complete peel without residue Complete peel without residue Example 2 Complete peel without residue Complete peel without residue Complete peel without residue Example 3 Complete peel without residue Complete peel without residue Complete peel without residue Comparative Example Paint film became brittle and cracked Not easily peeled completely Paint film became soft and not easily peeled

[0068] In summary, from the test results of the above table, it can be seen that the strippable protective coating provided by the present application has greatly improved strippability compared to general water-based strippable coatings, and is easily completely stripped without residue between -20°C and 60°C, has long-term complete strippability, and is particularly suitable for temporary protection of the surface of various metal plate substrates.

[0069] While embodiments of the present application have been shown and described, it is to be understood that the embodiments described are merely divergences of the principles and spirit of the present application, and that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A high and low temperature resistant waterborne strippable protective coating, characterized by: The protective coating comprises the following components by weight: polyurethane emulsion 30-50 parts, epoxy resin 20-30 parts, acrylic emulsion 20-30 parts, polytetrafluoroethylene 10-15 parts, filler 20-30 parts, auxiliary agent 10-20 parts, and water in excess. The filler comprises the following components by weight: carbon fiber 4-6 parts, talcum powder 4-6 parts, mica powder 4-6 parts, bentonite 4-6 parts, and quartz powder 4-6 parts. The auxiliary agent comprises the following components by weight: plasticizer 2-4 parts, dispersant 2-4 parts, defoaming agent 2-4 parts, leveling agent 2-4 parts, and film-forming auxiliary agent 2-4 parts.

2. The waterborne strippable protective coating resistant to high and low temperature according to claim 1, characterized in that: The protective coating comprises the following components by weight: polyurethane emulsion 40 parts, epoxy resin 25 parts, acrylic emulsion 25 parts, polytetrafluoroethylene 13 parts, filler 25 parts, auxiliary agent 15 parts, and water in excess.

3. The waterborne strippable protective coating resistant to high and low temperature according to claim 1, characterized in that: The plasticizer is dioctyl phthalate, the dispersant is sodium polyacrylate, the defoaming agent is polyether siloxane copolymer, the leveling agent is polyether-modified siloxane, and the film-forming auxiliary agent is any one or more of dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, and tripropylene glycol n-butyl ether.

4. A process for the preparation of a high and low temperature resistant water borne strippable protective coating as claimed in claim 1, wherein: The method comprises the following steps: Step one: mix the polyurethane emulsion, epoxy resin, acrylic emulsion, polytetrafluoroethylene, and water, and stir until uniform to obtain a mixed solution A; Step two: add the filler to the mixed solution A, and continue to stir until uniformly dispersed to obtain a mixed solution B; Step three: add the auxiliary agent and pH adjuster to the mixed solution B, and stir thoroughly to obtain a mixed solution C; Step four: filter the final mixed solution C to obtain the finished protective coating.

5. The preparation method of the high and low temperature resistant waterborne strippable protective coating according to claim 4, characterized in that: In steps one to three, the stirring speed is 500-1500 rpm, and the stirring time is 30-60 min.

6. The preparation method of the high and low temperature resistant water-based strippable protective coating of claim 5, characterized in that: In step two, each type of filler is added for 1-3 min, and after adding, the mixture is stirred for 5-10 min before adding the next type of filler. After adding all the fillers, the mixture is stirred at a speed of 1200-1500 rpm for 20-30 min.

7. The preparation method of the high and low temperature resistant water-based strippable protective coating of claim 6, characterized in that: In step three, each type of auxiliary agent is added for 1-3 min, and after adding, the mixture is stirred for 5-10 min before adding the next type of auxiliary agent. After adding all the auxiliary agents, the mixture is stirred at a speed of 1200-1500 rpm for 20-30 min.

8. The preparation method of the high and low temperature resistant water-based strippable protective coating of claim 7, characterized in that: In step three, the pH adjuster is added to the mixed solution C until the pH is 7.3-7.8.

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