阅读说明：本技术 防闪蚀组合物、水性防闪蚀涂料及应用 (Anti-flash-corrosion composition, water-based anti-flash-corrosion coating and application ) 是由 廖芳芳 管亚敏 梁丽芸 李斌 张婧 王耀午 于 2019-10-21 设计创作，主要内容包括：本发明提供了一种防闪蚀组合物、水性防闪蚀涂料及应用,防闪蚀组合物包括防闪蚀剂；防闪蚀剂包括苯乙烯与选自对苯乙烯磺酸钠、马来酸酐、丙烯酸中的一种或多种共聚单体的共聚物。本发明提供的防闪蚀组合物中,防闪蚀剂包括具有酸根取代基的聚合物,具有较大的分子量,与金属表面的金属离子结合位点较多；并具有疏水链段和亲水链段,亲水链段的众多酸根基团可与金属表面的金属离子发生螯合反应,而使金属离子不会与水反应生成沉淀,防止金属表面的闪蚀,提高了防闪蚀的效果；同时螯合反应的产物对金属表面具有较高的附着力。(The invention provides an anti-flash composition, a water-based anti-flash coating and application, wherein the anti-flash composition comprises an anti-flash agent; the anti-flash agent comprises a copolymer of styrene and one or more comonomers selected from sodium p-styrene sulfonate, maleic anhydride and acrylic acid. In the anti-flash corrosion composition provided by the invention, the anti-flash corrosion agent comprises a polymer with an acid radical substituent group, has a larger molecular weight, and has more metal ion binding sites on the metal surface; the metal ion chelating agent has a hydrophobic chain segment and a hydrophilic chain segment, and a plurality of acid radical groups of the hydrophilic chain segment can generate chelating reaction with metal ions on the surface of metal, so that the metal ions can not react with water to generate precipitates, the flash corrosion of the surface of the metal is prevented, and the flash corrosion prevention effect is improved; meanwhile, the product of the chelation reaction has higher adhesive force to the metal surface.)

1. An anti-flash composition for use in aqueous coatings, characterized by: the anti-flash composition comprises an anti-flash agent; the anti-flash agent comprises a copolymer of styrene and one or more comonomers selected from sodium p-styrene sulfonate, maleic anhydride and acrylic acid.

2. The anti-flash composition according to claim 1, wherein the anti-flash agent comprises a polymer obtained by polymerizing maleic anhydride and styrene and then hydrolyzing the polymerized product.

3. The anti-flash composition according to claim 1, wherein the molar ratio of styrene to the comonomer is 1: 0.8 to 1.4.

4. The anti-flash composition according to claim 1, wherein the anti-flash agent comprises a polymer obtained by polymerizing styrene and maleic anhydride in a molar ratio of 1: 1 and then hydrolyzing the polymerized polymer.

5. The anti-flash agent composition according to claim 1, wherein the weight average molecular weight of the anti-flash agent is 3000 to 80000.

6. The anti-flash composition according to any one of claims 1 to 5, further comprising, based on 100 parts by weight of the anti-flash agent:

10 to 30 parts by weight of at least one selected from the group consisting of a graphene oxide-polyaniline composite, a reduced graphene oxide-polyaniline composite and polyaniline.

7. The anti-flash composition according to any one of claims 1 to 5, further comprising:

1600-2200 parts by weight of at least one anticorrosive additive selected from the group consisting of zinc phosphate, iron oxide red and mica powder.

8. The anti-flash composition according to any one of claims 1 to 5, wherein the anti-flash composition comprises 100 to 200 parts by weight of an anti-flash agent and 10 to 30 parts by weight of a reduced graphene oxide-polyaniline composite.

9. The anti-flash composition according to any one of claims 1 to 5, wherein the reduced graphene oxide-polyaniline composite has a weight ratio of reduced graphene oxide to polyaniline of 0.05 to 0.07.

10. An aqueous anti-flash coating, comprising:

100 parts by weight of a water-borne coating base; and

3-8 parts of an anti-flash agent, wherein the anti-flash agent comprises a copolymer of styrene and one or more comonomers selected from sodium p-styrene sulfonate, maleic anhydride and acrylic acid.

11. The aqueous anti-glare coating of claim 10,

further comprising 0.3 to 1.2 parts by weight of at least one selected from the group consisting of a graphene oxide-polyaniline composite, a reduced graphene oxide-polyaniline composite and polyaniline.

12. The aqueous anti-glare coating of claim 11,

further comprises 45-90 parts by weight of at least one anti-corrosion additive selected from the group consisting of zinc phosphate, iron oxide red and mica powder.

13. The aqueous anti-glare coating of claim 10,

the water-based paint matrix is selected from one or more of polyacrylic acids, polymethacrylic acids, polyacrylates, water-based organic silicon modified acrylates, self-crosslinking polyacrylic acids, water-based epoxy and water-based polyurethane.

14. The aqueous anti-glare coating of claim 10,

further comprises at least one additive selected from the group consisting of pigments, dispersants, thickeners, leveling agents, and defoamers.

15. The aqueous anti-corrosive paint according to any one of claims 10 to 14,

comprises the following components in parts by weight: 3-8 parts of an anti-flash corrosion agent, 0.3-1.2 parts of a reduced graphene oxide-polyaniline compound, 9-20 parts of zinc phosphate, 18-24 parts of iron oxide red, 21-36 parts of mica powder, 24-48 parts of a pigment, 9-20 parts of a dispersing agent, 9-20 parts of a thickening agent, 9-20 parts of a leveling agent, 6-15 parts of an antifoaming agent, 100-150 parts of a polyacrylate emulsion, and the balance of water.

16. Use of the aqueous anti-flash-erosion coating of any one of claims 10 to 15 in the coating of metal distribution boxes.

Technical Field

The invention relates to the technical field of metal anti-flash corrosion, and particularly relates to an anti-flash corrosion composition, a water-based anti-flash corrosion coating and application thereof.

Background

As an important engineering and structural material, steel is easy to corrode and rust, and the loss of metal materials can be effectively reduced by protecting metal from corrosion. Among them, the most effective and inexpensive protective measure is to apply an anticorrosive coating to the metal surface. With the popularization of the green environmental protection concept, the water-based industrial coating is friendly to people and environment due to the adoption of water as a dispersion medium, and becomes one of the development directions of the coating. At present, the application of the water-based industrial coating in China is gradually expanded, and the application of the water-based metal anticorrosive coating is promoted due to the fact that the discharge standard of organic volatile substances (VOC) of the coating is limited by the government of China since 2015, and the coating with the VOC of more than 430g/L is subject to consumption tax. However, compared with organic solvents, water has a high boiling point and is slowly volatilized, and the drying process of the water-based industrial coating is slower than that of the traditional solvent-based coating containing organic volatile matters, so that when the water-based industrial coating is used for coating metals, the metals are easily corroded in a short time. Therefore, there is a need to develop an aqueous anticorrosive coating that can overcome the flash corrosion of metals and improve the corrosion resistance of metals.

In order to solve the problem of metal flash corrosion of the water-based industrial paint, the main strategy at present is to add various anti-corrosion additives into the water-based industrial paint, wherein the common additives comprise nitrobenzene ring compounds, zinc phosphate/sodium phosphate, ZnO nanoparticles, conductive carbon black fillers, silane coupling agents and the like, but the additives belong to small molecular substances, have few binding sites with rust and have poor compatibility with film-forming substances in the water-based industrial paint.

Disclosure of Invention

The invention aims to provide an anti-flash-corrosion composition, a water-based anti-flash-corrosion coating and application thereof, and aims to solve the technical problem that the water-based industrial coating in the prior art is easy to cause flash corrosion to metal.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

in a first aspect of the invention, there is provided an anti-flash composition for use in an aqueous coating, the anti-flash composition comprising an anti-flash agent; the anti-flash agent comprises a copolymer of styrene and one or more comonomers selected from sodium p-styrene sulfonate, maleic anhydride and acrylic acid.

Further, the anti-flash agent comprises a polymer obtained by polymerizing maleic anhydride and styrene and then hydrolyzing.

Further, the molar ratio of the styrene to the comonomer is 1: 0.8-1.4.

Further, the anti-flash agent comprises a polymer obtained by polymerizing styrene and maleic anhydride in a molar ratio of 1: 1 and then hydrolyzing.

Further, the weight average molecular weight of the anti-flash agent is 3000-80000.

Further, the anti-flash composition further comprises, based on 100 parts by weight of the anti-flash agent: 10 to 30 parts by weight of at least one selected from the group consisting of a graphene oxide-polyaniline composite, a reduced graphene oxide-polyaniline composite and polyaniline.

Further, the anti-flash erosion composition further comprises: 1600-2200 parts by weight of at least one anticorrosive additive selected from the group consisting of zinc phosphate, iron oxide red and mica powder.

Further, the anti-flash corrosion composition comprises 100-200 parts by weight of an anti-flash corrosion agent and 10-30 parts by weight of a reduced graphene oxide-polyaniline composite.

Further, in the reduced graphene oxide-polyaniline compound, the weight ratio of the reduced graphene oxide to the polyaniline is 0.05-0.07.

According to a second aspect of the present invention, there is also provided an aqueous anti-glare coating comprising: 100 parts by weight of a water-borne coating base; and 3-8 parts by weight of an anti-flash agent, wherein the anti-flash agent comprises a copolymer of styrene and one or more comonomers selected from sodium p-styrene sulfonate, maleic anhydride and acrylic acid.

Further, the paint further comprises 0.3-1.2 parts by weight of at least one selected from the group consisting of graphene oxide-polyaniline composite, reduced graphene oxide-polyaniline composite and polyaniline.

Further, the paint further comprises 45-90 parts by weight of at least one anti-corrosion additive selected from the group consisting of zinc phosphate, iron oxide red and mica powder.

Further, the water-based paint matrix is selected from one or more of polyacrylic acids, polymethacrylic acids, polyacrylates, water-based organic silicon modified acrylic esters, self-crosslinking polyacrylic acids, water-based epoxy and water-based polyurethane.

Further, at least one additive selected from the group consisting of pigments, dispersants, thickeners, leveling agents, and antifoaming agents is further included.

Further, the composition comprises the following components in parts by weight: 3-8 parts of an anti-flash corrosion agent, 0.3-1.2 parts of a reduced graphene oxide-polyaniline compound, 9-20 parts of zinc phosphate, 18-24 parts of iron oxide red, 21-36 parts of mica powder, 24-48 parts of a pigment, 9-20 parts of a dispersing agent, 9-20 parts of a thickening agent, 9-20 parts of a leveling agent, 6-15 parts of an antifoaming agent, 100-150 parts of a polyacrylate emulsion, and the balance of water.

According to a third aspect of the invention, the application of the water-based anti-flash-corrosion coating in coating of a metal power distribution box is also provided.

In the anti-flash corrosion composition provided by the invention, the anti-flash corrosion agent comprises a polymer with an acid radical substituent group, has a larger molecular weight, and has more metal ion binding sites on the metal surface; the metal ion chelating agent has a hydrophobic chain segment and a hydrophilic chain segment, and a plurality of acid radical groups of the hydrophilic chain segment can generate chelating reaction with metal ions on the surface of metal, so that the metal ions can not react with water to generate precipitates, the flash corrosion of the surface of the metal is prevented, and the flash corrosion prevention effect is improved; meanwhile, the product of the chelation reaction has higher adhesive force to the metal surface.

Drawings

Fig. 1 is an infrared spectrum of graphene oxide, polyaniline, a physical mixture of graphene oxide and polyaniline, and a reduced graphene oxide-polyaniline composite in an embodiment of the present invention;

FIG. 2 is a transmission electron microscope image of a reduced graphene oxide-polyaniline composite and a transmission electron microscope image of graphene oxide and polyaniline in an embodiment of the present invention;

FIG. 3 is a polarization curve of electrochemical performance test of samples in examples of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

In a first aspect of embodiments of the present invention, there is provided an anti-flash composition for use in an aqueous coating, comprising an anti-flash agent; wherein the anti-flash agent comprises a copolymer of styrene and one or more comonomers selected from sodium p-styrene sulfonate, maleic anhydride and acrylic acid.

Flash rust refers to the phenomenon of rust spots appearing on the surface of a metal substrate during the drying process of a newly constructed water-based paint. In the process of drying the water-based paint, water in the water-based paint contacts the surface of the metal substrate, so that the flash rust problem is easily caused; particularly, when the air humidity is high, the drying speed of the coating film is low, so that the contact time of water in the water-based paint and the metal surface is too long, and the flash rust problem is serious. The coating is resistant to flash corrosion because there is a substance that can absorb rust from the metal surface or some substance in the coating can react with the rust.

In the anti-flash etching composition provided by the embodiment of the invention, the anti-flash etching agent comprises a polymer with an acid radical substituent group, has a larger molecular weight, and has more metal ion binding sites on the metal surface; the metal ion chelating agent has a hydrophobic chain segment and a hydrophilic chain segment, and a plurality of acid radical groups of the hydrophilic chain segment can generate chelating reaction with metal ions on the surface of metal, so that the metal ions can not react with water to generate precipitates, the flash corrosion of the surface of the metal is prevented, and the flash corrosion prevention effect is improved; meanwhile, the product of the chelation reaction has higher adhesive force to the metal surface.

Specifically, the polymerization process of the anti-flash agent of the embodiment of the invention is as follows: adding styrene and one or more comonomers selected from sodium p-styrenesulfonate, maleic anhydride and acrylic acid into a four-mouth bottle containing a solvent according to a ratio, heating, adding an initiator, reacting for 6-24 h, stopping heating, cooling to room temperature, discharging, washing and drying; then adding into alkaline water for hydrolysis to obtain the anti-flash agent. Wherein, the solvent can adopt one of toluene, dimethylbenzene, butyl acetate and water; the initiator can adopt one of azodiisobutyronitrile and benzoyl peroxide; the alkaline water for hydrolysis can be ammonia water or sodium hydroxide.

In some embodiments, the molar ratio of styrene to comonomer when polymerized is 1: 0.8 to 1.4. Wherein the anti-flash agent comprises a polymer obtained by polymerizing styrene and maleic anhydride and then hydrolyzing. Further, in one embodiment, the molar ratio of styrene to maleic anhydride is 1: 1. In the above reaction, styrene and maleic anhydride are polymerized and hydrolyzed to obtain carboxyl groups, and polymers having different properties can be obtained by varying the degree of hydrolysis.

In the embodiment of the invention, the weight average molecular weight of the anti-flash agent is 3000-80000. The molecular weight of the anti-flash agent of the embodiment of the invention is obviously larger than that of the anti-flash agent of small molecules reported in the prior art, such as nitrobenzene ring compounds, zinc phosphate/sodium phosphate, ZnO nanoparticles, conductive carbon black filler, silane coupling agent and the like. The anti-flash agent has increased molecular weight and hydrophilic acid radical end, so that it has enough sites to combine with metal ion on the surface of metal via chelating reaction, and has raised anti-flash effect.

In some embodiments, the anti-flash composition further comprises, based on 100 parts by weight of the anti-flash agent: 10 to 30 parts by weight of at least one selected from the group consisting of a graphene oxide-polyaniline composite, a reduced graphene oxide-polyaniline composite and polyaniline.

In the research process, the combination of the anti-flash agent and one or more of the graphene oxide-polyaniline compound, the reduced graphene oxide-polyaniline compound and the polyaniline is found to have a synergistic effect, so that the anti-flash effect and the metal corrosion prevention effect can be further improved. Wherein the weight ratio of the graphene oxide to the polyaniline in the graphene oxide-polyaniline composite is 0.05-0.07. The hydrophobic chain segment of the anti-flash agent has good compatibility with the hydrophobic chain segments in the component structures of the graphene oxide-polyaniline compound, the reduced graphene oxide-polyaniline compound and the polyaniline, and the compatibility of the anti-flash agent and a film forming substance in the composition is improved.

In addition, the anti-flash agent provided by the embodiment of the invention has good surface activity due to the structural characteristics, has good dispersion effect on the components of the graphene oxide-polyaniline compound, the reduced graphene oxide-polyaniline compound and the polyaniline, and can better exert the anti-corrosion performance.

In some embodiments, the anti-flash composition consists of 100 to 200 parts by weight of an anti-flash agent and 10 to 30 parts by weight of a reduced graphene oxide-polyaniline composite. The reduced graphene oxide-polyaniline compound has better synergistic effect than other compounds and an anti-flash agent, so that the corrosion rate of the metal surface is greatly reduced. Wherein in the reduced graphene oxide-polyaniline compound, the weight ratio of the reduced graphene oxide to the polyaniline is 0.05-0.07.

In some embodiments, the anti-flash composition further comprises: 1600-2200 parts by weight of at least one anticorrosive additive selected from the group consisting of zinc phosphate, iron oxide red and mica powder. The anti-corrosion additive can reduce the cost of the paint and improve the barrier effect of a paint film on corrosive substances.

In a second aspect of embodiments of the present invention, there is provided an aqueous anti-glare paint comprising 100 parts by weight of an aqueous paint base; and 3-8 parts by weight of an anti-flash agent; wherein the anti-flash agent comprises a copolymer of styrene and one or more comonomers selected from sodium p-styrene sulfonate, maleic anhydride and acrylic acid. The anti-flash agent provided by the embodiment of the invention can be combined with various common water-based paint matrixes to improve the anti-flash effect of the water-based paint. On one hand, the hydrophobic chain segment of the anti-flash agent has good compatibility with the hydrophobic chain segment of the water-based paint matrix, and carboxylate radicals in the hydrophilic chain segment of the anti-flash agent can generate chelation reaction with metal ions on the metal surface to prevent flash corrosion of the metal surface; on the other hand, the anti-flash agent has a larger molecular weight, increasing the binding sites of the coating to the metal ions on the metal surface.

In some embodiments, the aqueous coating matrix is selected from one or more of the group consisting of polyacrylics, polymethacrylics, polyacrylates, aqueous silicone modified acrylates, self-crosslinking polyacrylics, aqueous epoxies, aqueous polyurethanes. The anti-flash agent can generate a synergistic effect with one or more of the water-based paint matrixes, has good compatibility and can better form a film.

In some embodiments, the aqueous anti-flash coating further comprises 0.3 to 1.2 parts by weight of at least one selected from the group consisting of a graphene oxide-polyaniline composite, a reduced graphene oxide-polyaniline composite, and polyaniline. One or more components of graphene oxide-polyaniline compound, reduced graphene oxide-polyaniline compound and polyaniline are added into the water-based anti-flash coating, so that the anti-flash effect and the anti-corrosion effect of the metal surface can be further improved.

In other embodiments, the aqueous anti-flash coating further comprises 45-90 parts by weight of at least one anti-corrosion additive selected from the group consisting of zinc phosphate, iron oxide red, and mica powder. The anti-corrosion additive can reduce the cost of the paint, improve the barrier effect of a paint film on corrosive substances and reduce corrosion. Further, the aqueous anti-flash coating further comprises at least one additive selected from the group consisting of pigments, dispersants, thickeners, leveling agents, and defoamers.

In some preferred embodiments, the aqueous anti-glare coating comprises the following components in parts by weight: 3-8 parts of the anti-flash corrosion agent, 0.3-1.2 parts of reduced graphene oxide-polyaniline compound, 9-20 parts of zinc phosphate, 18-24 parts of iron oxide red, 21-36 parts of mica powder, 24-48 parts of pigment, 9-20 parts of dispersing agent, 9-20 parts of thickening agent, 9-20 parts of flatting agent, 6-15 parts of defoaming agent, 100-150 parts of polyacrylate emulsion and the balance of water.

The water-based anti-flash-corrosion coating disclosed by the embodiment of the invention has excellent anti-flash-corrosion and isolation anti-corrosion functions, and simultaneously, due to the conductive functions of the graphene and the polyaniline, the metal base material has an antistatic effect, so that the water-based anti-flash-corrosion coating can be applied to the fields of power equipment, chemical engineering, oceans and the like in the future, and has a wide prospect.

In some embodiments, a method of preparing a reduced graphene oxide-polyaniline composite comprises the steps of:

s1, dispersing graphene oxide in water to obtain a graphene suspension; adding aniline into dilute acid solution to form dilute acid aniline mixed solution; dissolving an oxidant in a dilute acid solution to obtain a dilute acid mixed solution of the oxidant;

s2, mixing the graphene suspension obtained in the step S1 with diluted acid aniline mixed solution, adding the oxidant diluted acid mixed solution obtained in the step S1, and reacting to obtain a first product;

s3, adding alkali liquor into the first product obtained in the step S2 to adjust the pH value, and then adding a reducing agent to react to obtain the reduced graphene oxide-polyaniline compound.

Wherein the graphene oxide is prepared by a Hummers method, a Staudemaier method, an electrochemical method or a Brodie method and is not subjected to reduction treatment.

In terms of corrosion protection, electrical conductivity is a critical factor. The conductivity of the reduced graphene oxide-polyaniline composite is much better than that of the graphene oxide-polyaniline composite, because a large number of oxidation groups exist in the preparation process of the graphene oxide, the conductivity is influenced, but the oxidation groups are greatly reduced after the reduction of the reducing agent in the step S3, so that the conductivity of the graphene is improved, and the corrosion resistance of the water-based anti-flash-corrosion coating is improved. Further, hydrazine hydrate is used as the reducing agent in step S3.

Further, in step S1, the oxidant is one or more selected from the group consisting of ferric trichloride, ammonium persulfate, potassium perchlorate, and benzoyl peroxide.

The preparation method of the water-based anti-flash-erosion coating in the embodiment of the invention comprises the following steps: (1) mixing water with a dispersant, adding an anti-flash agent, a reduced graphene oxide-polyaniline compound, zinc phosphate, iron oxide red, mica powder and a pigment, dispersing and grinding; (2) and adding polyacrylate emulsion, a thickening agent, a flatting agent and a defoaming agent, and stirring and dispersing to obtain the water-based anti-flash-erosion coating. In the embodiment of the present invention, when the reduced graphene oxide-polyaniline composite is replaced with a graphene oxide-polyaniline composite, or the reduced graphene oxide and polyaniline are replaced with other substrates, the preparation method is similar to the above preparation method, and details are not repeated here.

In order to ensure that the water-based anti-flash-erosion coating of the embodiment of the invention can be stored for a long time and cannot be layered, the mixed substance in the step (1) is dispersed in a grinding tank at a high speed until the fineness reaches 30-50 μm; stirring and dispersing in the step (2) until defoaming, adding a pH value regulator to regulate the pH value to 7-8, and regulating the viscosity to 3000 cps-4000 cps. When the aqueous anti-flash coating of the embodiment of the present invention is used, about 10% of water is added to the coating for dilution depending on the viscosity of the coating.

In a third aspect of the embodiments of the present invention, there is provided an application of the above-mentioned aqueous anti-flash-erosion coating in coating of a metal distribution box. Due to the good conductive function of graphene and polyaniline in the water-based anti-flash-corrosion coating, after the metal distribution box is coated, the distribution box has excellent anti-flash-corrosion and isolation anti-corrosion functions and an antistatic effect.