CN111440504B

CN111440504B - Water-based anticorrosive paint and preparation method and application thereof

Info

Publication number: CN111440504B
Application number: CN202010348672.7A
Authority: CN
Inventors: 叶朋朋; 段芳勇; 黄玲凤; 陶伟钧; 邢俊; 胡子和
Original assignee: Bauhinia Paints Shanghai Co ltd
Current assignee: Bauhinia Paints Shanghai Co ltd
Priority date: 2020-04-28
Filing date: 2020-04-28
Publication date: 2022-04-08
Anticipated expiration: 2040-04-28
Also published as: CN111440504A

Abstract

The invention provides a water-based anticorrosive paint and a preparation method and application thereof. The water-based anticorrosive paint comprises the following components in percentage by mass: 20-40% of organic silicon modified water-based acrylic emulsion, 20-40% of water-based aliphatic polyurethane, 15-20% of titanium dioxide, 2-4% of film forming additive, 3-8% of antirust pigment, 0.2-1% of flash rust inhibitor and the balance of water. The water-based anticorrosive coating has the advantages of low surface drying time, short drying time, high hardness, wear resistance, temperature resistance, water resistance and salt spray resistance, good flexibility, high adhesion and good anticorrosive performance, and particularly shows excellent cracking resistance when sprayed under a semi-dry or non-dry state of a wet silicone adhesive film.

Description

Water-based anticorrosive paint and preparation method and application thereof

Technical Field

The invention belongs to the technical field of anticorrosive coatings, and particularly relates to a water-based anticorrosive coating, and a preparation method and application thereof.

Background

On a building site, a movable board house is usually used as an office and a dormitory for civil workers. The movable board house can be coated when being manufactured by a manufacturer. With the push of the national environmental protection policy, some mobile board house manufacturers have started to change oil to water, i.e., the original oil-based steel structure coating for coating is changed into a water-based steel structure coating. However, during use, a problem is found. The general prefabricated house can be built by adopting color steel sandwich plates. In the process of building, because the color steel plate is integral, the joints such as wall corners and window edges have gaps, and sealing material silicone adhesive is needed. To improve production efficiency, field workers sometimes spray aqueous coatings with the silicone adhesive semi-dry or not dry. Because the silicone adhesive of the first layer is not dried completely and is coated with the water-based paint, the shrinkage stress of the inner layer and the outer layer is inconsistent in the drying process, and the elasticity of the finish paint is not enough, the water-based paint film can crack, and higher requirements are provided for the water-based paint.

At present, the application of the waterborne polyurethane resin is continuously extended to the fields of coatings, adhesives and the like, and the waterborne polyurethane resin has excellent mechanical properties and flexibility after film formation, has good chemical resistance and weather resistance, and is very suitable for outdoor coating. However, the higher cost of the aqueous acrylic emulsion compared to the more mature aqueous acrylic emulsion is one of the reasons for inhibiting its development in aqueous coatings.

CN109929428A discloses a low-viscosity steel structure anticorrosive paint and a construction process thereof, wherein the paint is prepared from a component A and a component B in parts by mass, wherein the component A comprises the following components: 80-100 parts of water-based hydroxyl acrylic acid, 1.5-2.5 parts of dispersant, 0.6-1.5 parts of defoamer, 0.8-2 parts of antiseptic bactericide, 5-7 parts of cellulose, 38-42 parts of titanium dioxide, 0.4-0.9 part of film-forming assistant and 18-24 parts of deionized water; the component B comprises: 20-24 parts of isocyanate, 15-20 parts of propylene glycol methyl ether acetate and 0.2-0.5 part of tartaric acid; the low-viscosity steel structure anticorrosive paint is a two-component polyurethane antirust primer, has long-term antirust and anticorrosive capacity, and has a water-based paint film which cracks and is dried for a long time.

CN109777232A discloses a water-based modified acrylic acid anticorrosive paint and a preparation method thereof, wherein the water-based modified acrylic acid anticorrosive paint comprises the following components in parts by weight: 400 portions of core-shell structure acrylic emulsion; 100 portions and 250 portions of soap-free acrylic emulsion; 30-150 parts of pigment; 100 portions of filler and 300 portions; 0-50 parts of color paste; 3-10 parts of a dispersing agent; 1-3 parts of a wetting agent; 1-3 parts of a defoaming agent; 5-15 parts of propylene glycol; 0.5-5 parts of multifunctional auxiliary agent; 1-3 parts of a mildew inhibitor; 1-3 parts of a preservative; 10-15 parts of a film-forming assistant; 5-10 parts of a thickening agent; 1-2 parts of a neutralizing agent; 1-5 parts of a leveling agent; 5-15 parts of a flash inhibitor; 150 portions of softened water and 200 portions of softened water. The paint has low VOC content, good corrosion resistance, poor mechanical property and flexibility and long drying time.

Therefore, the development of a water-based steel structure anticorrosive paint which has good flexibility and elasticity and is not easy to crack after film formation is the key point of the current research in the field.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a water-based anticorrosive paint and a preparation method and application thereof. The water-based anticorrosive coating has the advantages of low surface drying time, short drying time, high hardness, wear resistance, temperature resistance, water resistance and salt spray resistance, good flexibility, high adhesion and better corrosion resistance, and particularly has excellent cracking resistance when the water-based anticorrosive coating is sprayed on a silicone adhesive wet film in a semi-dry or non-dry state, so that the problem of cracking of the paint film caused by inconsistent shrinkage stress of the inner layer and the outer layer and insufficient elasticity of the finish paint in the drying process of the paint film is effectively solved, the workability is improved, and the construction time is effectively shortened.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the invention provides a water-based anticorrosive paint, which comprises the following components in percentage by mass: 20-40% of organic silicon modified water-based acrylic emulsion, 20-40% of water-based aliphatic polyurethane, 15-20% of titanium dioxide, 2-4% of film forming additive, 3-8% of antirust pigment, 0.2-1% of flash rust inhibitor and the balance of water.

In the invention, the water-based anticorrosive paint is obtained by compounding organic silicon modified water-based acrylic emulsion and water-based aliphatic polyurethane, wherein the organic silicon modified water-based acrylic emulsion is organic silicon modified water-based acrylic emulsion formed by graft copolymerization of acrylic esters and organic silicon monomers, and the water-based aliphatic polyurethane is aliphatic polyurethane dispersoid. The organic silicon modified water-based acrylic emulsion is functionalized resin modified by long-chain polysiloxane, one end of a molecular chain contains reactive hydroxyl functional groups, and the organic silicon modified water-based acrylic emulsion can be firmly combined with water-based aliphatic polyurethane in a chemical bond mode and cannot migrate in the using process, so that the organic silicon modified water-based acrylic emulsion has better durability. Meanwhile, siloxane groups of the organosilicon modified water-based acrylic emulsion can gradually migrate to the outside of high-surface-energy components of the emulsion, so that siloxane chain segments are formed and are enriched on the surface of the emulsion adhesive film, and due to the long-chain structure of the aliphatic polyurethane, the active siloxane groups enriched on the surface of the emulsion and the polyurethane form a three-dimensional network (-Si-O-Si-) crosslinking structure, so that chemical crosslinking points are increased, the compactness of the surface layer of a coating film is enhanced, and the mechanical performance of the coating film is finally improved. The titanium dioxide has good whiteness and good grinding wettability, can further improve the weather resistance of the water-based anticorrosive paint, and has good chemical stability, small granularity, high covering power and decoloring power, and good opacity and glossiness.

The content of the silicone-modified aqueous acrylic emulsion is 20 to 40%, for example, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, etc., based on 100% by mass of the aqueous anticorrosive coating.

The content of the aqueous aliphatic polyurethane is 20 to 40% by mass of the aqueous anticorrosive coating, and may be, for example, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, or the like.

In the invention, the content of the organosilicon modified water-based acrylic emulsion and the content of the water-based aliphatic polyurethane are set in the ranges, so that the water-based anticorrosive paint can be ensured not to crack when sprayed in a silicone adhesive wet film or a non-dried state, and simultaneously has excellent impact resistance, flexibility, surface drying time, actual drying time and hardness. If the content of the organic silicon modified water-based acrylic emulsion and the content of the water-based aliphatic polyurethane are not in the range, the problem of cracking of a paint film is caused because the shrinkage stress of an inner layer and an outer layer is inconsistent and the elasticity of a finish paint is insufficient in the drying process of the paint film when the organic silicon modified water-based acrylic emulsion and the water-based aliphatic polyurethane are too little; when the amount of the silicone-modified aqueous acrylic emulsion is too small and the amount of the aqueous aliphatic polyurethane is too large, the impact resistance and flexibility of the paint film are improved, but the surface drying time, the actual drying time and the hardness of the paint film are remarkably reduced.

The content of the titanium dioxide is 15-20% by mass of the water-based anticorrosive paint as 100%, and can be 15%, 16%, 17%, 18%, 19%, 20% and the like.

The content of the film forming aid is 2 to 4% by mass of the aqueous anticorrosive paint, and may be, for example, 2%, 2.5%, 3%, 3.5%, 4%, etc.

The content of the anticorrosive pigment is 3 to 8%, for example, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, etc., based on 100% by mass of the aqueous anticorrosive paint.

The content of the flash rust inhibitor is 0.2 to 1% by mass of the aqueous anticorrosive paint, and may be, for example, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, or the like.

Preferably, the silicone-modified aqueous acrylic emulsion has a solids content of 36 to 48 wt%, and may be, for example, 36 wt%, 37 wt%, 38 wt%, 39 wt%, 40 wt%, 41 wt%, 42 wt%, 43 wt%, 44 wt%, 45 wt%, 46 wt%, 47 wt%, 48 wt%, and the like.

The viscosity of the silicone-modified aqueous acrylic emulsion is preferably 200-2500 mPas, and may be, for example, 200-, 400-, 600-, 800-, 1000-, 1200-, 1400-, 1600-, 1800-, 2000-, 2200-, 2500-mPas.

Preferably, the silicone-modified aqueous acrylic emulsion has a pH of 7 to 9, and may be, for example, 7, 7.2, 7.4, 7.6, 7.8, 8, 8.2, 8.4, 8.6, 8.8, 9, and the like.

Preferably, the organosilicon modified water-based acrylic emulsion comprises the balanced water new light XG-908A and/or the balanced water new light XG-9100, has good salt fog resistance, alkali resistance and water resistance, and simultaneously has strong adhesive force on metal materials and excellent weather resistance.

Preferably, the weight average molecular weight of the aqueous aliphatic polyurethane is 20000-50000, and can be 20000, 25000, 30000, 35000, 40000, 45000, 50000, and the like.

Preferably, the aqueous aliphatic polyurethane has a solid content of 34 to 41 wt%, which may be, for example, 34 wt%, 35 wt%, 36 wt%, 37 wt%, 38 wt%, 39 wt%, 40 wt%, 41 wt%, etc.

The viscosity of the aqueous aliphatic polyurethane is preferably 10 to 200 mPas, and may be, for example, 10 mPas, 20 mPas, 40 mPas, 60 mPas, 80 mPas, 100 mPas, 120 mPas, 140 mPas, 160 mPas, 180 mPas, 200 mPas, or the like.

Preferably, the aqueous aliphatic polyurethane comprises Wanhua chemical Lacper 4211 and/or Opadodi U7400, and the aqueous aliphatic polyurethane is an aliphatic polyurethane dispersion which has good flexibility and good compatibility with acrylic emulsion.

Preferably, the titanium dioxide is rutile type titanium dioxide.

Preferably, the content of titanium dioxide in the titanium dioxide is more than 95%, for example, 95%, 96%, 97%, 98%, 99%, 100%, etc., based on 100% of the mass of the rutile titanium dioxide.

Preferably, the titanium dioxide comprises dupont R902+ and/or hensman TR 92.

Preferably, the coalescent comprises an ester coalescent and/or an ether coalescent, preferably an alcohol ester-12 and/or dipropylene glycol butyl ether (DOW DPNB).

Preferably, the rust inhibitive pigment is zinc phosphate. The salt spray resistance of the water-based anticorrosive paint is improved by improving a passivation coating mechanism of a substrate.

Preferably, the zinc content is > 45% (e.g., 46%, 47%, 48%, 49%, 50%, 51%, 52%, etc.) and the phosphorus oxide content is > 43% (e.g., 48%, 49%, 50%, 51%, 52%, 53%, 54%, etc.) based on 100% by mass of zinc phosphate.

Preferably, the ZINC PHOSPHATE comprises HALOX ZINC PHOSPHATE and/or SNCZ PZ 20.

Preferably, the anti-flash rust agent comprises a metal organic chelate.

Preferably, the flash rust inhibitor does not contain sodium nitrite.

Preferably, the metal-organic chelate compound comprises Raybo 60 and/or hofmann T730.

Preferably, the aqueous anticorrosive coating further comprises any one or a combination of at least two of a dispersant, a wetting agent, an antifoaming agent, a pH adjuster, a preservative, or a thickener.

Preferably, the dispersant is added in an amount of 0.8 to 1.5%, for example, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, etc., based on 100% by mass of the aqueous anticorrosive paint.

Preferably, the dispersant comprises BYK190 and/or tego 735W. The dispersant is a high molecular weight copolymer solution containing pigment affinic groups.

Preferably, the addition amount of the wetting agent is 0.1 to 0.3%, for example, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, etc., based on 100% by mass of the aqueous anticorrosive coating.

Preferably, the wetting agent comprises a silicone based wetting agent, preferably tego4100 and/or BYK 346.

The siloxane wetting agent greatly reduces the surface tension of the coating, so that the coating is spread evenly.

The amount of the defoaming agent added is preferably 0.2 to 0.4%, for example, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, or the like, based on 100% by mass of the aqueous anticorrosive coating material.

Preferably, the defoamer comprises a polyether siloxane based defoamer and/or a mineral oil based defoamer, preferably BYK024 and/or CF 247.

Preferably, the amount of the pH adjuster added is 0.1 to 0.2%, for example, 0.1%, 0.11%, 0.12%, 0.14%, 0.16%, 0.18%, 0.2%, or the like, based on 100% by mass of the aqueous anticorrosive paint.

Preferably, the pH adjusting agent is 2-amino-2-methyl-1-propanol.

Preferably, the 2-amino-2-methyl-1-propanol is DOW AMP-95.

Preferably, the preservative is added in an amount of 0.1 to 0.2%, for example, 0.1%, 0.11%, 0.12%, 0.14%, 0.16%, 0.18%, 0.2%, etc., based on 100% by mass of the aqueous anticorrosive paint.

Preferably, the preservative comprises an isothiazolinone fungicide, preferably ACTICIDE RS and/or MBS. The preservative is used as a preservative in the tank.

Preferably, the thickener is added in an amount of 0.5 to 1.5%, for example, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, etc., based on 100% by mass of the aqueous anticorrosive paint.

Preferably, the thickener comprises a non-ionic hydrophobically modified polyurethane rheology agent, preferably RM 8W and/or PUR 42.

Preferably, the water-based anticorrosive paint comprises the following components in percentage by mass: 20-40% of organic silicon modified water-based acrylic emulsion, 20-40% of water-based aliphatic polyurethane, 15-20% of titanium dioxide, 2-4% of film forming additive, 3-8% of antirust pigment, 0.2-1% of flash rust inhibitor, 0.8-1.5% of dispersant, 0.1-0.3% of wetting agent, 0.2-0.4% of defoaming agent, 0.1-0.2% of pH regulator, 0.1-0.2% of preservative, 0.5-1.5% of thickening agent and the balance of water;

preferably, the viscosity of the aqueous anticorrosive paint is 85-95KU/30 ℃, and may be, for example, 85KU/30 ℃, 86KU/30 ℃, 87KU/30 ℃, 88KU/30 ℃, 89KU/30 ℃, 90KU/30 ℃, 91KU/30 ℃, 92KU/30 ℃, 93KU/30 ℃, 94KU/30 ℃, 95KU/30 ℃ or the like.

In a second aspect, the present invention provides a method for preparing the aqueous anticorrosive paint according to the first aspect, the method for preparing the aqueous anticorrosive paint comprises: mixing the organic silicon modified water-based acrylic emulsion, the water-based aliphatic polyurethane, the titanium dioxide, the film forming additive, the antirust pigment, the flash rust inhibitor and water according to the formula amount to obtain the water-based anticorrosive paint.

Preferably, the preparation method of the water-based anticorrosive paint comprises the following steps:

(1) mixing and dispersing a dispersing agent, a wetting agent, a defoaming agent, a pH regulator and water to obtain a dispersion liquid A;

(2) mixing and dispersing the dispersion liquid A obtained in the step (1), titanium dioxide and an anti-rust pigment to obtain a dispersion liquid B;

(3) and (3) mixing and stirring the dispersion liquid B obtained in the step (2) with a film-forming aid, a preservative, an anti-flash rust agent, an organic silicon modified water-based acrylic emulsion, water-based aliphatic polyurethane and a thickening agent to obtain the water-based anticorrosive paint.

Preferably, the rotation speed of the dispersion in step (1) is 500-600r/min, such as 500r/min, 510r/min, 520r/min, 530r/min, 540r/min, 550r/min, 560r/min, 570r/min, 580r/min, 590r/min, 600r/min, etc., and the dispersion time is 3-5min, such as 3min, 3.2min, 3.4min, 3.6min, 3.8min, 4min, 4.2min, 4.4min, 4.6min, 4.8min, 5min, etc.

Preferably, the rotation speed of the dispersion in the step (2) is 1000-1200r/min, such as 1000r/min, 1050r/min, 1100r/min, 1150r/min, 1200r/min, etc., and the dispersion time is 20-30min, such as 20min, 22min, 24min, 26min, 28min, 30min, etc.

The fineness of the dispersion B in the step (2) is preferably 40 μm or less, and may be, for example, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm or the like.

Preferably, the rotation speed of the mixing and stirring in the step (3) is 500-700r/min, such as 500r/min, 520r/min, 540r/min, 560r/min, 580r/min, 600r/min, 620r/min, 640r/min, 680r/min, 700r/min, etc., and the time of the mixing and stirring is 3-15min, such as 3min, 5min, 7min, 9min, 11min, 13min, 15min, etc.

(1) adding a dispersing agent, a wetting agent, a defoaming agent and a pH regulator into water, and dispersing for 3-5min at the rotating speed of 500-600r/min to obtain a dispersion liquid A;

(2) adding titanium dioxide and an anti-rust pigment into the dispersion liquid A obtained in the step (1), and dispersing for 20-30min at the rotating speed of 1000-1200r/min to obtain a dispersion liquid B with the fineness of below 40 mu m;

(3) and (3) sequentially adding a film forming aid, a preservative, an anti-flash rust agent, an organic silicon modified water-based acrylic emulsion and water-based aliphatic polyurethane into the dispersion liquid B obtained in the step (2), mixing and stirring at the rotating speed of 500-700r/min for 3-5min, adding a thickening agent, adjusting the viscosity of the coating to 85-95KU/30 ℃, and continuing stirring for 5-10min to obtain the water-based anticorrosive coating.

In a third aspect, the invention provides a use of the water-based anticorrosive paint in the first aspect for corrosion prevention of steel structures. In particular to a silicone adhesive wet film which is sprayed on a steel structure in a semi-dry or non-dry state by the water-based anticorrosive paint.

Compared with the prior art, the invention has the following beneficial effects:

(1) the water-based anticorrosive coating disclosed by the invention has the advantages of low surface drying time, short drying time, high hardness, high wear resistance, high temperature resistance, high water resistance, high salt spray resistance, good flexibility, high adhesion and better anticorrosive performance.

(2) The water-based anticorrosive paint provided by the invention is sprayed on a silicone adhesive wet film, and can simultaneously meet the requirements that the surface drying time is within 20-40min, the actual drying time is within 12-16h, the salt spray resistance is above 120h, the adhesive force is below grade 1, the impact resistance is as high as above 60cm, the hardness reaches B or 2B, the flexibility is below 1mm, the anti-cracking performance is excellent, and a paint film is not cracked after being dried.

(3) When the wet silicone adhesive film is in a semi-dry or non-dry state, the waterborne anticorrosive paint still shows excellent cracking resistance when sprayed on the wet silicone adhesive film, so that the problem of cracking of the paint film caused by inconsistent shrinkage stress of the inner layer and the outer layer and insufficient elasticity of the finish paint in the drying process of the paint film is effectively solved, the workability is improved, and the construction time is effectively shortened.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

The embodiment provides a water-based anticorrosive paint, which comprises the following components in percentage by mass: 40% of organic silicon modified water-based acrylic emulsion, 20% of water-based aliphatic polyurethane, 18% of titanium dioxide, 3% of film forming additive, 5% of antirust pigment, 0.5% of flash rust inhibitor, 1% of dispersing agent, 0.2% of wetting agent, 0.4% of defoaming agent, 0.2% of pH regulator, 0.2% of preservative, 1.3% of thickening agent and 10.2% of water.

In the embodiment, the organosilicon modified water-based acrylic emulsion is selected from water balance, Xinguang XG-908A, the water-based aliphatic polyurethane is selected from Wanhua chemical Lacper 4211, the titanium dioxide is selected from DuPont R902+, the film forming additive is alcohol ester-12, the antirust pigment is ZINC PHOSPHATE (HALOX ZINC PHOSPHATE), the anti-flash rust agent is selected from Raybo 60, the dispersing agent is selected from BYK190, the wetting agent is selected from tego4100, the defoaming agent is selected from BYK024, the pH regulator is 2-amino-2-methyl-1-propanol (DOW AMP-95), the preservative is selected from ACTICIDE RS, and the thickening agent is selected from RM 8W.

The preparation method of the water-based anticorrosive paint comprises the following steps:

(1) adding a dispersing agent, a wetting agent, a defoaming agent and a pH regulator into water according to the formula amount, and dispersing for 5min at the rotating speed of 500r/min to obtain a dispersion liquid A;

(2) adding titanium dioxide and an anti-rust pigment into the dispersion liquid A obtained in the step (1), and dispersing for 30min at the rotating speed of 1000r/min to obtain a dispersion liquid B with the fineness of 30 mu m;

(3) and (3) sequentially adding a film forming aid, a preservative, an anti-flash rust agent, an organic silicon modified water-based acrylic emulsion and water-based aliphatic polyurethane into the dispersion liquid B obtained in the step (2), mixing and stirring at the rotating speed of 500r/min for 5min, adding a thickening agent, adjusting the viscosity of the coating to 90KU/30 ℃, and continuing to stir for 5min to obtain the water-based anticorrosive coating.

Example 2

The embodiment provides a water-based anticorrosive paint, which comprises the following components in percentage by mass: 25% of organic silicon modified water-based acrylic emulsion, 35% of water-based aliphatic polyurethane, 18% of titanium dioxide, 3% of film forming additive, 5% of antirust pigment, 0.5% of flash rust inhibitor, 1% of dispersing agent, 0.2% of wetting agent, 0.4% of defoaming agent, 0.2% of pH regulator, 0.2% of preservative, 1.2% of thickening agent and 10.3% of water.

In the embodiment, the organic silicon modified water-based acrylic emulsion is selected from constant water Xinguang XG-9100, the water-based aliphatic polyurethane is selected from Opadry U7400, the titanium dioxide is selected from Hensman TR92, the film forming additive is dipropylene glycol butyl ether (DOW DPNB), the antirust pigment is zinc phosphate (SNCZ PZ20), the flash rust inhibitor is selected from Hofmann T730, the dispersant is selected from tego735W, the wetting agent is selected from BYK346, the antifoaming agent is selected from CF247, the pH regulator is 2-amino-2-methyl-1-propanol (DOW AMP-95), the antiseptic is selected from MBS, and the thickening agent is selected from PUR 42.

(1) adding a dispersing agent, a wetting agent, a defoaming agent and a pH regulator into water according to the formula amount, and dispersing for 3min at the rotating speed of 600r/min to obtain a dispersion liquid A;

(2) adding titanium dioxide and an anti-rust pigment into the dispersion liquid A obtained in the step (1), and dispersing for 20min at the rotating speed of 1200r/min to obtain a dispersion liquid B with the fineness of 30 mu m;

(3) and (3) sequentially adding a film forming aid, a preservative, an anti-flash rust agent, an organic silicon modified water-based acrylic emulsion and water-based aliphatic polyurethane into the dispersion liquid B obtained in the step (2), mixing and stirring at the rotating speed of 700r/min for 3min, adding a thickening agent, adjusting the viscosity of the coating to 92KU/30 ℃, and continuing to stir for 10min to obtain the water-based anticorrosive coating.

Example 3

This example provides a water-based anticorrosive paint, which is different from example 1 only in that the content of the silicone-modified water-based acrylic emulsion is 20%, the content of the water-based aliphatic polyurethane is 40%, and the content of other components and the preparation method are the same as example 1.

Example 4

This example provides a water-based anticorrosive coating, which is different from example 1 in that the viscosity of the silicone-modified water-based acrylic emulsion is 100mPa · s, and the contents of other components and the preparation method are the same as those of example 1.

Example 5

This example provides a water-based anticorrosive coating, which is different from example 1 in that the viscosity of the silicone-modified water-based acrylic emulsion is 3000 mPas, and the contents of other components and the preparation method are the same as those of example 1.

Example 6

This example provides an aqueous anticorrosive paint, which is different from example 1 in that the weight average molecular weight of the aqueous aliphatic polyurethane is 10000, and the contents of other components and the preparation method are the same as example 1.

Example 7

This example provides an aqueous anticorrosive coating, which is different from example 1 in that the weight average molecular weight of the aqueous aliphatic polyurethane is 60000, and the contents of other components and the preparation method are the same as example 1.

Example 8

The embodiment provides a water-based anticorrosive paint, which is different from the embodiment 1 in that the titanium dioxide is replaced by anatase titanium dioxide, and the contents of other components and the preparation method are the same as those in the embodiment 1.

Example 9

This example provides an aqueous anticorrosive paint, which is different from example 1 in that the anticorrosive pigment is replaced by aluminum tripolyphosphate, and the contents of other components and the preparation method are the same as those of example 1.

Example 10

The embodiment provides a water-based anticorrosive paint, which is different from the embodiment 1 in that the viscosity of the water-based anticorrosive paint is 80KU/30 ℃, and the contents of other components and the preparation method are the same as the embodiment 1.

Example 11

The embodiment provides a water-based anticorrosive paint, which is different from the embodiment 1 in that the viscosity of the water-based anticorrosive paint is 100KU/30 ℃, and the contents of other components and the preparation method are the same as the embodiment 1.

Comparative example 1

The embodiment provides a water-based anticorrosive paint, which is different from the embodiment 1 in that no water-based aliphatic polyurethane is added into the water-based anticorrosive paint, the content of the organosilicon modified water-based acrylic emulsion is increased to 60%, and the content of other components and the preparation method are the same as the embodiment 1.

Comparative example 2

The embodiment provides a water-based anticorrosive paint, which is different from the embodiment 1 in that the content of the organic silicon modified water-based acrylic emulsion is 50%, the content of the water-based aliphatic polyurethane is 10%, and the content of other components and the preparation method are the same as the embodiment 1.

Comparative example 3

The embodiment provides a water-based anticorrosive paint, which is different from the water-based anticorrosive paint in embodiment 1 in that the content of the organosilicon modified water-based acrylic emulsion is 10%, the content of the water-based aliphatic polyurethane is 50%, and the content of other components and the preparation method are the same as those in embodiment 1.

Comparative example 4

The embodiment provides a water-based anticorrosive paint, which is different from the embodiment 1 in that no organic silicon modified water-based acrylic emulsion is added into the water-based anticorrosive paint, the content of the water-based aliphatic polyurethane is 60%, and the content of other components and the preparation method are the same as the embodiment 1.

Comparative example 5

The embodiment provides a water-based anticorrosive paint, which is different from the embodiment 1 in that the titanium dioxide is replaced by lithopone, and the contents of other components and the preparation method are the same as those in the embodiment 1.

Comparative example 6

This example provides an aqueous anticorrosive coating, which is different from example 1 in that the content of the film-forming aid is 1%, the content of water is 12.2%, and the contents of other components and the preparation method are the same as those in example 1.

Comparative example 7

This example provides an aqueous anticorrosive coating, which is different from example 1 in that the content of the film-forming aid is 5%, the content of water is 8.2%, and the contents of other components and the preparation method are the same as those of example 1.

Performance testing

The aqueous anticorrosive coatings provided in examples 1 to 11 and the aqueous anticorrosive coatings provided in comparative examples 1 to 7 were respectively sprayed on a silicone adhesive wet film, and then the performance test of a coating matching system was performed according to HG/T5716-:

TABLE 1

TABLE 2

According to the test data, the water-based anticorrosive coating provided by the invention can be sprayed on a silicone adhesive wet film, the surface drying time is within 20-40min, the actual drying time is within 12-16h, the salt spray resistance is above 120h, the adhesion is below 1 grade, the impact resistance is as high as above 60cm, the hardness is B or 2B, the flexibility is below 1mm, the anti-cracking performance is excellent, and the paint film is not cracked after being actually dried. When the wet silicone adhesive film is in a semi-dry or non-dry state, the waterborne anticorrosive paint still shows excellent cracking resistance when sprayed on the wet silicone adhesive film, so that the problem of cracking of the paint film caused by inconsistent shrinkage stress of the inner layer and the outer layer and insufficient elasticity of the finish paint in the drying process of the paint film is effectively solved, the workability is improved, and the construction time is effectively shortened.

Example 4 the viscosity of the organosilicon modified aqueous acrylic emulsion is too low, the freeze-thaw stability of the prepared coating after film formation is poor, and the coating is easy to deteriorate after 3 cycles. Example 5 the viscosity of the silicone-modified aqueous acrylic emulsion was too high, and the coating prepared therefrom had poor early water resistance after film formation and was liable to foam. The weight average molecular weight of the water-based aliphatic polyurethane in the examples 6 and 7 is too low or too high, and after the prepared coating is formed into a film, the early water resistance is poor, the foaming is easy, the salt spray resistance is poor, and more rusty spots appear on the coating film in a 120-hour salt spray resistance test. And when the weight average molecular weight of the waterborne aliphatic polyurethane is too low, the toughness of the prepared coating after film formation is poor. Example 8 provides an example of replacing titanium dioxide with anatase titanium dioxide, where the weather resistance of the paint film after titanium dioxide replacement is poor, the paint film is discolored after long-term illumination, and the Δ E is greater than 3 when tested by QUV400 h. Example 9 aluminum tripolyphosphate was used as an anti-rust pigment instead of the preferred zinc phosphate in this application, and the resulting coating was poor in freeze-thaw stability after film formation and prone to deterioration after 3 cycles. The viscosity of the water-based anticorrosive paint in example 10 is too low, and the paint film is easy to sag during application, so that the application is difficult. Example 11 the viscosity of the waterborne corrosion resistant coating was too high and the leveling of the paint film was found to be poor when applied.

As is clear from the comparison between example 1 and comparative examples 1 and 2, when the content of the aqueous aliphatic polyurethane is too low or when the aqueous aliphatic polyurethane is not added, the paint film is cracked due to inconsistent shrinkage stresses between the inner and outer layers during the drying process and insufficient elasticity of the top coat.

As can be seen from the comparison between example 1 and comparative examples 3 and 4, the impact resistance and flexibility of the paint film are improved when the organosilicon-modified aqueous acrylic emulsion is not added or when the content of the organosilicon-modified aqueous acrylic emulsion is too small, but the surface drying time, the actual drying time and the hardness of the paint film are obviously reduced, and the construction time and the construction difficulty are increased.

As can be seen from the comparison between example 1 and comparative examples 6 and 7, the paint film has poor anti-cracking performance due to too low content of the film-forming assistant, cracks after the paint film is dried, the lowest film-forming temperature of the emulsion is not reduced, and the paint film can not form a film continuously when the air temperature is too low; the content of the film-forming additive is too much, the boiling point of the film-forming additive is higher than 190 ℃, the drying speed is slow, the drying time of the coating is slow, and the coating can be completely dried for more than 24 hours.

The applicant states that the invention is illustrated by the above examples of the water-based anticorrosive paint and the preparation method and application thereof, but the invention is not limited to the above examples, i.e. it does not mean that the invention must be implemented by means of the above examples. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

Claims

1. The application of the water-based anticorrosive paint in steel structure corrosion prevention is characterized in that the water-based anticorrosive paint comprises the following components in percentage by mass: 22-40% of organic silicon modified water-based acrylic emulsion, 22-40% of water-based aliphatic polyurethane, 15-20% of titanium dioxide, 2-4% of film forming additive, 3-8% of antirust pigment, 0.2-1% of flash rust inhibitor, 0.8-1.5% of dispersant, 0.1-0.3% of wetting agent, 0.2-0.4% of defoaming agent, 0.1-0.2% of pH regulator, 0.1-0.2% of preservative, 0.5-1.5% of thickening agent and the balance of water;

the viscosity of the organic silicon modified water-based acrylic emulsion is 200-2500mPa & s;

the weight-average molecular weight of the aqueous aliphatic polyurethane is 20000-50000;

the viscosity of the water-based anticorrosive paint is 85-95KU/30 ℃;

the application specifically comprises the steps of spraying the water-based anticorrosive paint on a steel structure silicone adhesive wet film;

when the water-based anticorrosive coating is applied to a silicone adhesive wet film, the surface drying time is within 20-40min, the actual drying time is within 12-16h, the salt spray resistance is over 120h, the adhesive force is below grade 1, the impact resistance is up to more than 60cm, the hardness reaches B or 2B, the flexibility is below 1mm, and a paint film does not crack after being actually dried.

2. The use according to claim 1, wherein the silicone-modified aqueous acrylic emulsion has a solids content of 36 to 48 wt.%.

3. Use according to claim 1, characterized in that the silicone-modified aqueous acrylic emulsion has a pH of 7 to 9.

4. Use according to claim 1, characterized in that the aqueous aliphatic polyurethane has a solid content of 34-41 wt%;

5. use according to claim 1, characterized in that the viscosity of the aqueous aliphatic polyurethane is 10-200 mPa-s.

6. The use according to claim 1, characterized in that the titanium dioxide is rutile titanium dioxide.

7. Use according to claim 1, wherein the film-forming adjuvant comprises an ester film-forming adjuvant and/or an ether film-forming adjuvant.

8. Use according to claim 7, wherein the film-forming aid is alcohol ester-12 and/or dipropylene glycol butyl ether.

9. Use according to claim 1, characterized in that the rust-inhibiting pigment is zinc phosphate.

10. Use according to claim 1, wherein the anti-flash rust agent comprises a metal-organic chelate.

11. Use according to claim 1, wherein the dispersant comprises BYK190 and/or tego 735W.

12. Use according to claim 1, wherein the wetting agent comprises a siloxane-based wetting agent.

13. Use according to claim 12, wherein the wetting agent is tego4100 and/or BYK 346.

14. Use according to claim 1, wherein the antifoaming agent comprises a polyether siloxane type antifoaming agent and/or a mineral oil type antifoaming agent.

15. Use according to claim 14, wherein the defoamer is BYK024 and/or CF 247.

16. Use according to claim 1, characterized in that the pH adjusting agent is 2-amino-2-methyl-1-propanol.

17. Use according to claim 1, wherein the preservative comprises an isothiazolinone biocide.

18. Use according to claim 17, wherein the preservative is ACTICIDE RS and/or MBS.

19. Use according to claim 1, characterized in that said thickening agent comprises a non-ionic hydrophobically modified polyurethane rheological agent.

20. Use according to claim 19, wherein said thickener is RM 8W and/or PUR 42.

21. The use according to any one of claims 1 to 20, wherein the aqueous anticorrosive paint is prepared by: mixing the organic silicon modified water-based acrylic emulsion, the water-based aliphatic polyurethane, the titanium dioxide, the film forming additive, the antirust pigment, the flash rust inhibitor and water according to the formula amount to obtain the water-based anticorrosive paint.

22. The use according to claim 21, wherein the preparation method of the water-based anticorrosive paint comprises the following steps:

23. The use as claimed in claim 22, wherein the rotation speed of the dispersion in step (1) is 500-600r/min, and the dispersion time is 3-5 min.

24. The use as claimed in claim 22, wherein the rotation speed of the dispersion in step (2) is 1000-1200r/min, and the dispersion time is 20-30 min.

25. Use according to claim 22, characterized in that the fineness of the dispersion B of step (2) is below 40 μm.

26. The use as claimed in claim 22, wherein the rotation speed of the mixing and stirring in step (3) is 500-700r/min, and the mixing and stirring time is 3-15 min.

27. The use according to claim 22, wherein the preparation method of the water-based anticorrosive paint comprises the following steps: