CN111363443A - Anticorrosive paint for building materials and preparation method thereof - Google Patents

Abstract

The invention discloses an anticorrosive paint for building materials, which is prepared from the following raw materials in parts by weight: 40-50 parts of modified acrylic emulsion, 0.8-1 part of modified graphene, 9-13 parts of titanium dioxide, 8-10 parts of talcum powder, 1.2-1.6 parts of antirust additive, 5-6 parts of auxiliary agent and 20-30 parts of deionized water; the invention also discloses a preparation method of the anticorrosive paint. The modified acrylic emulsion is used as a film forming substance of the coating, so that the coating not only has good film forming performance and adhesive force, but also has excellent water resistance and aging resistance; through the addition of the antirust additive, the antirust effect can be achieved, and the corrosion inhibition function is also achieved; through the addition of the modified graphene, the modified graphene serves as an excellent shielding layer, the contact between building materials and corrosive media is slowed down, the corrosion resistance is enhanced, the bonding degree with a matrix is high, and the corresponding effect is more easily exerted; the water-based anticorrosive coating with excellent comprehensive performance is obtained and is suitable for protecting metal building materials.

Description

Anticorrosive paint for building materials and preparation method thereof

Technical Field

The invention belongs to the technical field of coatings, and particularly relates to an anticorrosive coating for building materials and a preparation method thereof.

Background

The building materials are a general term for materials used in civil engineering and construction engineering, and include wood, concrete, composite materials, metal materials, and the like. Among them, metal materials play an important role in building materials, however, the corrosion-prone property of metal materials affects the use effect of the building materials, and therefore, the corrosion prevention of metal type building materials is particularly important. One of the current economic and applicable methods for metal corrosion protection is to add a layer of coating with high compactness and stability on the metal surface to improve the corrosion resistance.

Chinese patent with patent number CN201710950949.1 discloses an environment-friendly anticorrosive paint which comprises the following components in parts by weight: the raw materials comprise the following components in parts by weight: 80-98 parts of aqueous polyurethane emulsion, 60-78 parts of polyacrylate emulsion, 45-52 parts of polyacrylate emulsion, 25-32 parts of toluene diisocyanate, 8-13 parts of pigment, 1.0-3.2 parts of organic tin complex, 0.9-1.5 parts of stabilizer, 1.2-2.3 parts of thickener, 2.3-4.2 parts of flatting agent and 5.0-10.9 parts of filler. The addition of the organic tin complex is beneficial to improving the dry adhesion of the paint, and the surface smoothness and hardness of the anticorrosive paint are improved by the hollow microspheres. However, the coating cannot play a role in waterproofing and rust prevention, and therefore, the application of the coating to the surface of a building material made of a metal material is limited.

Disclosure of Invention

The invention aims to provide an anticorrosive coating for building materials and a preparation method thereof, wherein the modified acrylic emulsion is used as a film forming substance of the coating, so that the coating not only has good film forming property and adhesive force, but also has excellent water resistance and aging resistance; by adding the antirust additive, the antirust paint not only can play a role in antirust, but also has a corrosion inhibition function, and when the antirust additive is added into the paint, building materials can be effectively protected, and the anticorrosion effect of the paint is enhanced; through the addition of the modified graphene, the modified graphene can be uniformly dispersed in an emulsion matrix and serves as an excellent shielding layer to block the permeation of water molecules and electrolyte, slow down the contact between building materials and corrosive media, enhance the corrosion resistance, and is high in bonding degree with the matrix and easier to play a corresponding role; the water-based anticorrosive coating with excellent comprehensive performance is obtained and is suitable for protecting metal building materials.

The purpose of the invention can be realized by the following technical scheme:

an anticorrosive paint for building materials is prepared from the following raw materials in parts by weight: 40-50 parts of modified acrylic emulsion, 0.8-1 part of modified graphene, 9-13 parts of titanium dioxide, 8-10 parts of talcum powder, 1.2-1.6 parts of antirust additive, 5-6 parts of auxiliary agent and 20-30 parts of deionized water;

the anticorrosive paint is prepared by the following steps:

firstly, sequentially adding modified graphene, titanium dioxide and talcum powder into modified acrylic emulsion, heating to 80-90 ℃, dispersing at a high speed of 1000r/min at constant temperature for 25-30min at 800-;

secondly, adding the thickening agent, the dispersing agent and the coupling agent in the auxiliary agent into 1/3-volume deionized water, stirring and mixing uniformly, adding into the premix, dispersing for 10-12min at the speed of 400-500r/min, adding the antirust additive, and continuously dispersing for 8-10 min;

and step three, finally adding a film forming auxiliary agent and a defoaming agent, adding the rest deionized water, and dispersing for 15-17min at the speed of 200-300r/min to prepare the anticorrosive coating.

Further, the auxiliary agent comprises a dispersing agent, a coupling agent, a film-forming auxiliary agent, a thickening agent and a defoaming agent, and the mass ratio is 2:3:20:7.5: 10.

Further, the antirust additive is a compound of diethanolamine, sodium tetraborate, diethylenetriamine and phytic acid, and the mass ratio of the diethanolamine, the sodium tetraborate and the diethylenetriamine is 2: 1: 1: 0.5.

further, the modified graphene is prepared by the following method:

1) ultrasonically dispersing graphene oxide powder in dimethylformamide to form uniform graphene oxide dispersion liquid;

2) adding 4-aminostyrene and ammonia water, and carrying out reflux reaction for 20 hours at the temperature of 95 ℃;

3) after the reaction is finished, washing the reaction product for 6 to 8 times by using absolute ethyl alcohol, and then drying the reaction product for 24 hours at the temperature of 50 ℃ to obtain intermediate graphene.

Further, the amount of dimethylformamide, 4-aminostyrene and ammonia added per 1g of graphene oxide powder is 25-28mL, 0.3-0.4mL and 2-3mL in this order.

Further, the modified acrylic emulsion is prepared by the following method:

(1) adding a polyoxyethylene octyl phenol ether/sodium dodecyl sulfate composite emulsifier into a four-neck flask provided with a condenser pipe, a thermometer and a nitrogen guide pipe, adding deionized water, and uniformly stirring to obtain a mixed solution;

(2) mixing methacrylic acid, methyl methacrylate and butyl acrylate according to the mass ratio of 3:1:2 to form a mixed monomer solution, and dropwise adding the mixed monomer solution into the mixed solution obtained in the previous step by using a constant-pressure dropping funnel to obtain a pre-emulsified monomer;

(3) taking out half of the pre-emulsified monomer, heating to 75 ℃, dropwise adding half of the ammonium persulfate aqueous solution, reacting for 20-25min, then adding the taken out pre-emulsified monomer and hexafluorobutyl methacrylate, dropwise adding the rest ammonium persulfate aqueous solution, keeping the system at a constant temperature, after dropwise adding, slowly heating to 80 ℃, continuing to react for 2h, cooling the obtained emulsion, and adopting a pH regulator NaHCO₃Adjusting the pH value to 6.9-7.1, and filtering to obtain the modified acrylic emulsion.

A preparation method of an anticorrosive paint for building materials comprises the following steps:

firstly, sequentially adding modified graphene, titanium dioxide and talcum powder into modified acrylic emulsion, heating to 80-90 ℃, dispersing at a high speed of 1000r/min at constant temperature for 25-30min at 800-;

secondly, adding the thickening agent, the dispersing agent and the coupling agent in the auxiliary agent into 1/3-volume deionized water, stirring and mixing uniformly, adding into the premix, dispersing for 10-12min at the speed of 400-500r/min, adding the antirust additive, and continuously dispersing for 8-10 min;

and step three, finally adding a film forming auxiliary agent and a defoaming agent, adding the rest deionized water, and dispersing for 15-17min at the speed of 200-300r/min to prepare the anticorrosive coating.

The invention has the beneficial effects that:

the anticorrosive coating adopts modified acrylic emulsion as a film forming substance, hexafluorobutyl methacrylate, butyl acrylate, methacrylic acid and methyl methacrylate are taken as monomers by a semi-continuous emulsion polymerization method, under the action of a polyoxyethylene octylphenol ether-10 and sodium dodecyl sulfate composite emulsifier, ammonium hydrogen persulfate is taken as an initiator to synthesize the modified acrylic emulsion, and the modified acrylic emulsion is aqueous fluorine-containing acrylic emulsion which not only contains good film forming property of acrylic resin and adhesive force to a substrate, but also has excellent aging resistance and hydrophobic property of fluorine-containing polymer; the long-chain fluorine-containing groups are uniformly distributed in the linear resin, the side-chain fluorine-containing groups are exposed around the long chain, and fluorine elements with low surface energy property in the side chain are gathered on the surface due to easy rotation of the long chain, so that the contact angle of the coating is increased, the hydrophobic property of the coating is increased, and the bond energy of a C-F bond in the structure is high, the polarization rate is low, so that the aging resistance of the coating is good;

according to the invention, the antirust additive is added into the anticorrosive coating, and comprises diethanolamine, sodium tetraborate, diethylenetriamine and phytic acid, wherein the sodium tetraborate can generate an insoluble passivation film with iron ions and ferrous ions on the surface of a metal building material, the coverage area of the sodium tetraborate is wider, and the sodium tetraborate can play a role in protection for a long time, but the formed passivation film possibly has exposed pores or a thinner area, and polar groups such as nitrogen, hydroxyl and the like and hydrocarbon chains in the diethanolamine are adsorbed on the surface of the building material in a molecular film forming manner, so that the concentration value of critical chloride ions is increased, and the contact of harmful substances with the surface of the building material is further prevented; the amino group in the antirust component can also improve the performance of capillary tubes in the coating, so that harmful ions such as chloride ions and the like are difficult to reach the surface of the building material through diffusion, in addition, diethylenetriamine can be compounded with sodium tetraborate to form a stable complex, and the stable complex is adsorbed on the surface of the building material through coordination bonds, so that the antirust effect is further improved; the phytic acid is a polydentate metal chelate, can form a stable complex with various metal ions within a wider pH range, and is an environment-friendly corrosion inhibitor; the antirust additive can play an antirust effect and also has a corrosion inhibition function, and can effectively protect building materials and enhance the anticorrosion effect of the coating when added into the coating;

according to the invention, modified graphene is added into the raw material of the anticorrosive paint, and in the preparation process of the modified graphene, an oxygen group (epoxy group, carboxyl group and the like) on the graphene oxide and an amino group on 4-aminostyrene undergo nucleophilic substitution reaction to generate a C-NH-C bond, so that the 4-aminostyrene is grafted on the graphene oxide; due to steric hindrance, nucleophilic substitution reaction between amine groups in the 4-aminostyrene and epoxy functional groups of the graphene oxide enables the graphene oxide sheets to deform to form wrinkles, interaction between graphene sheet layers is weakened, agglomeration phenomenon between the graphene is reduced, in addition, the 4-aminostyrene can be used as a spacer to inhibit direct stacking of the graphene oxide in the coating and avoid the agglomeration phenomenon, so that excellent dispersion of the modified graphene in the coating is facilitated, the modified graphene with fewer oxygen-containing functional groups can hinder permeation of water molecules to a certain extent, the uniformly dispersed flaky modified graphene serves as an excellent shielding layer in the coating, permeation of water molecules and electrolyte is hindered, contact between building materials and corrosive media is slowed down, corrosion resistance is enhanced, and the conductivity of the graphene can lead out electrons in a cathode corrosion area in time, the corrosion resistance of the coating is improved to a certain extent; the 4-aminostyrene contains double bonds, can react with the double bonds which are not completely reacted in the acrylic emulsion, improves the binding capacity of the graphene and the polymer matrix, further improves the stability of the coating, and can play a role of the graphene;

the modified acrylic emulsion is used as a film forming substance of the coating, so that the coating not only has good film forming performance and adhesive force, but also has excellent water resistance and aging resistance; by adding the antirust additive, the antirust paint not only can play a role in antirust, but also has a corrosion inhibition function, and when the antirust additive is added into the paint, building materials can be effectively protected, and the anticorrosion effect of the paint is enhanced; through the addition of the modified graphene, the modified graphene can be uniformly dispersed in an emulsion matrix and serves as an excellent shielding layer to block the permeation of water molecules and electrolyte, slow down the contact between building materials and corrosive media, enhance the corrosion resistance, and is high in bonding degree with the matrix and easier to play a corresponding role; the water-based anticorrosive coating with excellent comprehensive performance is obtained and is suitable for protecting metal building materials.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

An anticorrosive paint for building materials is prepared from the following raw materials in parts by weight: 40-50 parts of modified acrylic emulsion, 0.8-1 part of modified graphene, 9-13 parts of titanium dioxide, 8-10 parts of talcum powder, 1.2-1.6 parts of antirust additive, 5-6 parts of auxiliary agent and 20-30 parts of deionized water;

the auxiliary agent comprises a dispersing agent, a coupling agent, a film-forming auxiliary agent, a thickening agent and a defoaming agent, the mass ratio is 2:3:20:7.5:1, preferably, the dispersing agent is 4050, the coupling agent is KH-550, the film-forming auxiliary agent is dodecyl alcohol ester, the thickening agent is a polyurethane alkali swelling thickening agent, and the defoaming agent is 110;

the antirust additive comprises diethanolamine, sodium tetraborate, diethylenetriamine and phytic acid, wherein the mass ratio of the diethanolamine to the sodium tetraborate to the diethylenetriamine is 2: 1: 1: 0.5;

sodium tetraborate can generate an insoluble passivation film with iron ions and ferrous ions on the surface of a metal building material, the film forming area is wide, and the passivation film can play a role of protection for a long time, but the formed passivation film possibly has exposed pores or a thin area, and polar groups such as nitrogen, hydroxyl and the like and hydrocarbon chains in diethanolamine are adsorbed on the surface of the building material in a form of forming a molecular film, so that the concentration value of critical chloride ions is increased, and the contact of harmful substances with the surface of the building material is further prevented; the amino group in the antirust component can also improve the performance of capillary tubes in the coating, so that harmful ions such as chloride ions and the like are difficult to reach the surface of the building material through diffusion, in addition, diethylenetriamine can be compounded with sodium tetraborate to form a stable complex, and the stable complex is adsorbed on the surface of the building material through coordination bonds, so that the antirust effect is further improved; the phytic acid is a polydentate metal chelate, can form a stable complex with various metal ions within a wider pH range, and is an environment-friendly corrosion inhibitor; the antirust additive can play an antirust effect and also has a corrosion inhibition function, and can effectively protect building materials and enhance the anticorrosion effect of the coating when added into the coating;

the modified graphene is prepared by the following method:

1) ultrasonically dispersing graphene oxide powder in dimethylformamide to form uniform graphene oxide dispersion liquid;

2) adding 4-aminostyrene and ammonia water, and carrying out reflux reaction for 20 hours at the temperature of 95 ℃;

3) after the reaction is finished, washing the graphene with absolute ethyl alcohol for 6 to 8 times, and then drying the graphene at the temperature of 50 ℃ for 24 hours to prepare intermediate graphene;

wherein the amount of dimethylformamide, 4-aminostyrene and ammonia water added to every 1g of graphene oxide powder is 25-28mL, 0.3-0.4mL and 2-3mL in sequence;

in the reflux reaction process, an oxygen group (epoxy group, carboxyl group and the like) on the graphene oxide and an amino group on the 4-aminostyrene undergo nucleophilic substitution reaction to generate a C-NH-C bond, so that the 4-aminostyrene is grafted on the graphene oxide; due to steric hindrance, nucleophilic substitution reaction between amine groups in the 4-aminostyrene and epoxy functional groups of the graphene oxide enables the graphene oxide sheets to deform to form wrinkles, interaction between graphene sheet layers is weakened, agglomeration phenomenon between the graphene is reduced, in addition, the 4-aminostyrene can be used as a spacer to inhibit direct stacking of the graphene oxide in the coating and avoid the agglomeration phenomenon, so that excellent dispersion of the modified graphene in the coating is facilitated, the modified graphene with fewer oxygen-containing functional groups can hinder permeation of water molecules to a certain extent, the uniformly dispersed flaky modified graphene serves as an excellent shielding layer in the coating, permeation of water molecules and electrolyte is hindered, contact between building materials and corrosive media is slowed down, corrosion resistance is enhanced, and the conductivity of the graphene can lead out electrons in a cathode corrosion area in time, the corrosion resistance of the coating is improved to a certain extent; the 4-aminostyrene contains double bonds, can react with the double bonds which are not completely reacted in the acrylic emulsion, improves the binding capacity of the graphene and the polymer matrix, further improves the stability of the coating, and can play a role of the graphene;

the modified acrylic emulsion is prepared by the following method:

(1) adding a composite emulsifier of polyoxyethylene octyl phenol ether/sodium dodecyl sulfate (the mass ratio of the polyoxyethylene octyl phenol ether to the sodium dodecyl sulfate is 2: 1) into a four-neck flask provided with a condenser pipe, a thermometer and a nitrogen guide pipe, adding deionized water (the adding amount of the deionized water is 2-3 times of the mass of the composite emulsifier), and uniformly stirring to obtain a mixed solution;

(2) mixing methacrylic acid, methyl methacrylate and butyl acrylate according to the mass ratio of 3:1:2 to form a mixed monomer solution, and dropwise adding the mixed monomer solution into the mixed solution obtained in the previous step by using a constant-pressure dropping funnel to obtain a pre-emulsified monomer;

(3) taking out half of the pre-emulsified monomer, heating to 75 ℃, dropwise adding half of the ammonium persulfate aqueous solution, reacting for 20-25min, then adding the taken out pre-emulsified monomer and hexafluorobutyl methacrylate, dropwise adding the rest ammonium persulfate aqueous solution, keeping the system at a constant temperature, after dropwise adding, slowly heating to 80 ℃, continuing to react for 2h, cooling the obtained emulsion, and adopting a pH regulator NaHCO₃Adjusting the pH value to 6.9-7.1, and filtering to obtain a modified acrylic emulsion;

wherein the using amount of the composite emulsifier is 2.3 percent, the using amount of the initiator ammonium persulfate is 0.4 percent, and the using amount of the hexafluorobutyl methacrylate is 8.6 percent;

through a semi-continuous emulsion polymerization method, hexafluorobutyl methacrylate, butyl acrylate, methacrylic acid and methyl methacrylate are taken as monomers, under the action of a polyoxyethylene octylphenol ether-10 and sodium dodecyl sulfate composite emulsifier, ammonium hydrogen persulfate is taken as an initiator to synthesize a modified acrylic emulsion, and the modified acrylic emulsion is an aqueous fluorine-containing acrylic emulsion which not only contains good film-forming property of acrylic resin and adhesive force to a substrate, but also has excellent aging resistance and hydrophobic property of a fluorine-containing polymer; the long-chain fluorine-containing groups are uniformly distributed in the linear resin, the side-chain fluorine-containing groups are exposed around the long chain, and fluorine elements with low surface energy property in the side chain are gathered on the surface due to easy rotation of the long chain, so that the contact angle of the coating is increased, the hydrophobic property of the coating is increased, and the bond energy of a C-F bond in the structure is high, the polarization rate is low, so that the aging resistance of the coating is good;

the preparation method of the coating comprises the following steps:

firstly, sequentially adding modified graphene, titanium dioxide and talcum powder into modified acrylic emulsion, heating to 80-90 ℃, dispersing at a high speed of 1000r/min at constant temperature for 25-30min at 800-;

secondly, adding the thickening agent, the dispersing agent and the coupling agent in the auxiliary agent into 1/3-volume deionized water, stirring and mixing uniformly, adding into the premix, dispersing for 10-12min at the speed of 400-500r/min, adding the antirust additive, and continuously dispersing for 8-10 min;

and step three, finally adding a film forming auxiliary agent and a defoaming agent, adding the rest deionized water, and dispersing for 15-17min at the speed of 200-300r/min to obtain the coating.

Example 1

An anticorrosive paint for building materials is prepared from the following raw materials in parts by weight: 40 parts of modified acrylic emulsion, 0.8 part of modified graphene, 9 parts of titanium dioxide, 8 parts of talcum powder, 1.2 parts of antirust additive, 5 parts of auxiliary agent and 20 parts of deionized water;

the coating is prepared by the following steps:

firstly, sequentially adding modified graphene, titanium dioxide and talcum powder into modified acrylic emulsion, heating to 80 ℃, dispersing at a high speed of 800r/min for 25min at a constant temperature to obtain a premix, and stopping heating;

secondly, adding a thickening agent, a dispersing agent and a coupling agent in the auxiliary agent into 1/3-volume deionized water, stirring and mixing uniformly, adding into the premix, dispersing for 10min at a speed of 400r/min, adding an antirust additive, and continuously dispersing for 8 min;

and step three, finally adding a film forming auxiliary agent and a defoaming agent, adding the rest deionized water, and dispersing for 15min at 200r/min to obtain the coating.

Example 2

An anticorrosive paint for building materials is prepared from the following raw materials in parts by weight: 45 parts of modified acrylic emulsion, 0.9 part of modified graphene, 11 parts of titanium dioxide, 9 parts of talcum powder, 1.4 parts of antirust additive, 5.5 parts of auxiliary agent and 25 parts of deionized water;

the coating is prepared by the following steps:

firstly, sequentially adding modified graphene, titanium dioxide and talcum powder into modified acrylic emulsion, heating to 85 ℃, dispersing at a high speed of 900r/min for 28min at a constant temperature to obtain a premix, and stopping heating;

secondly, adding a thickening agent, a dispersing agent and a coupling agent in the auxiliary agent into 1/3-volume deionized water, stirring and mixing uniformly, adding into the premix, dispersing for 11min at 450r/min, adding an antirust additive, and continuously dispersing for 9 min;

and step three, finally adding a film forming auxiliary agent and a defoaming agent, adding the rest deionized water, and dispersing for 16min at a speed of 250r/min to obtain the coating.

Example 3

An anticorrosive paint for building materials is prepared from the following raw materials in parts by weight: 50 parts of modified acrylic emulsion, 1 part of modified graphene, 13 parts of titanium dioxide, 10 parts of talcum powder, 1.6 parts of antirust additive, 6 parts of auxiliary agent and 30 parts of deionized water;

the coating is prepared by the following steps:

firstly, sequentially adding modified graphene, titanium dioxide and talcum powder into modified acrylic emulsion, heating to 90 ℃, dispersing at a high speed of 1000r/min for 30min at a constant temperature to obtain a premix, and stopping heating;

secondly, adding a thickening agent, a dispersing agent and a coupling agent in the auxiliary agent into 1/3-volume deionized water, stirring and mixing uniformly, adding into the premix, dispersing for 12min at the speed of 500r/min, adding an antirust additive, and continuously dispersing for 10 min;

and step three, finally adding a film forming auxiliary agent and a defoaming agent, adding the rest deionized water, and dispersing for 17min at the speed of 300r/min to obtain the coating.

Comparative example 1

The modified acrylic emulsion in the raw materials of the example 1 is changed into the common acrylic emulsion, and the rest raw materials and the preparation process are unchanged.

Comparative example 2

The modified graphene raw material in example 1 was replaced with ordinary graphene oxide, and the remaining raw materials and preparation process were unchanged.

Comparative example 3

The raw materials of the antirust additive in the example 1 are removed, and the rest of the raw materials and the preparation process are unchanged.

The anticorrosive coatings prepared in examples 1 to 3 and comparative examples 1 to 3 were subjected to the following performance tests:

coating a layer of anticorrosive paint on a tinplate test plate according to corresponding test requirements to obtain an anticorrosive coating, and carrying out performance test on the coating;

the water absorption is measured according to GB/T1034-2008; the salt spray resistance is tested according to GB/T1771-2007; the flexibility is tested according to GB/T1731-1993; impact resistance was tested according to GB/T1732 + 1993; the adhesion was tested according to GB/T1720-; pencil hardness was tested according to GB/T6739-:

	example 1	Example 2	Example 3	Comparative example 1	Comparative example 2	Comparative example 3
							Water absorption/%)	1.1	0.9	1.0	1.5	1.3	1.2
Resistant neutral salt fog/2000 h	No bubbling, no shedding and no rust Etching solution	No bubbling, no shedding and no rust Etching solution	No bubbling, no shedding and no rust Etching solution	The occurrence of blistering and shedding Elephant	Slight shedding and tarnishing Elephant	Occurrence of blistering and tarnishing Elephant
							Flexibility/mm	0.9	0.9	0.8	0.6	0.7	0.8
Impact resistance/cm	50	52	53	42	46	49
							adhesion/MPa	8.3	8.9	8.5	7.5	7.8	8.2
Hardness of pencil	2H	2H	2H	H	H	2H

From the table, the water absorption of the anticorrosive coatings prepared in examples 1 to 3 is 0.9 to 1.1%, which shows that the coatings prepared in the invention have excellent hydrophobic and water-resistant properties, and the anticorrosive coatings prepared in examples 1 to 3 do not foam, fall off or rust in 2000h of neutral salt spray, which shows that the anticorrosive coatings prepared in the invention have excellent anticorrosive effect; in terms of mechanical properties, the flexibility of the coating prepared in examples 1-3 is 0.8-0.9mm, and the impact resistance is 50-53cm, which shows that the anticorrosive coating prepared by the invention has good mechanical properties; the adhesion force of the coating prepared in the embodiments 1 to 3 is 8.3 to 8.9MPa, and the pencil hardness reaches 2H, which shows that the anticorrosive coating prepared by the invention has good adhesion force and better hardness; by combining the comparative example 1, the acrylic emulsion is modified, and the fluorine-containing alkyl chain is introduced, so that the hydrophobic property of the coating can be improved, and the mechanical property and the adhesive force of the coating can also be improved; by combining the comparative example 2, the modified graphene can be more uniformly distributed in the coating matrix, has strong binding force with the polymer matrix, and can more easily exert the shielding and barrier properties of the sheet graphene, so that the corrosion resistance of the coating is improved; the addition of the antirust additive is described in combination with comparative example 3, so that the protective effect on the surface of the building material can be improved, and the antirust and anticorrosive effects are achieved.

The preferred embodiments of the invention disclosed above are intended to be illustrative only. The preferred embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims (7)

1. The anticorrosive paint for building materials is characterized by being prepared from the following raw materials in parts by weight: 40-50 parts of modified acrylic emulsion, 0.8-1 part of modified graphene, 9-13 parts of titanium dioxide, 8-10 parts of talcum powder, 1.2-1.6 parts of antirust additive, 5-6 parts of auxiliary agent and 20-30 parts of deionized water;

the anticorrosive paint is prepared by the following steps:

firstly, sequentially adding modified graphene, titanium dioxide and talcum powder into modified acrylic emulsion, heating to 80-90 ℃, dispersing at a high speed of 1000r/min at constant temperature for 25-30min at 800-;

secondly, adding the thickening agent, the dispersing agent and the coupling agent in the auxiliary agent into 1/3-volume deionized water, stirring and mixing uniformly, adding into the premix, dispersing for 10-12min at the speed of 400-500r/min, adding the antirust additive, and continuously dispersing for 8-10 min;

and step three, finally adding a film forming auxiliary agent and a defoaming agent, adding the rest deionized water, and dispersing for 15-17min at the speed of 200-300r/min to prepare the anticorrosive coating.

2. The anticorrosive paint for building materials according to claim 1, wherein the auxiliary agent comprises a dispersing agent, a coupling agent, a film forming auxiliary agent, a thickening agent and a defoaming agent in a mass ratio of 2:3:20:7.5: 10.

3. The anticorrosive paint for building materials according to claim 1, wherein the antirust additive is a compound of diethanolamine, sodium tetraborate, diethylenetriamine and phytic acid, and the mass ratio of the diethanolamine, the sodium tetraborate and the diethylenetriamine is 2: 1: 1: 0.5.

4. the anticorrosive coating for building materials according to claim 1, wherein the modified graphene is prepared by the following method:

1) ultrasonically dispersing graphene oxide powder in dimethylformamide to form uniform graphene oxide dispersion liquid;

2) adding 4-aminostyrene and ammonia water, and carrying out reflux reaction for 20 hours at the temperature of 95 ℃;

3) after the reaction is finished, washing the reaction product for 6 to 8 times by using absolute ethyl alcohol, and then drying the reaction product for 24 hours at the temperature of 50 ℃ to obtain intermediate graphene.

5. The anticorrosive paint for building materials according to claim 4, wherein the amounts of dimethylformamide, 4-aminostyrene and ammonia water added per 1g of graphene oxide powder are 25 to 28mL, 0.3 to 0.4mL and 2 to 3mL in this order.

6. The anticorrosive paint for building materials according to claim 1, wherein the modified acrylic emulsion is prepared by the following method:

(1) adding a polyoxyethylene octyl phenol ether/sodium dodecyl sulfate composite emulsifier into a four-neck flask provided with a condenser pipe, a thermometer and a nitrogen guide pipe, adding deionized water, and uniformly stirring to obtain a mixed solution;

(2) mixing methacrylic acid, methyl methacrylate and butyl acrylate according to the mass ratio of 3:1:2 to form a mixed monomer solution, and dropwise adding the mixed monomer solution into the mixed solution obtained in the previous step by using a constant-pressure dropping funnel to obtain a pre-emulsified monomer;

(3) taking out half of the pre-emulsified monomer, heating to 75 ℃, dropwise adding half of the ammonium persulfate aqueous solution, reacting for 20-25min, then adding the taken out pre-emulsified monomer and hexafluorobutyl methacrylate, dropwise adding the rest ammonium persulfate aqueous solution, keeping the system at a constant temperature, after dropwise adding, slowly heating to 80 ℃, continuing to react for 2h, cooling the obtained emulsion, and adopting a pH regulator NaHCO₃Adjusting the pH value to 6.9-7.1, and filtering to obtain the modified acrylic emulsion.

7. The method for preparing an anticorrosive paint for building materials according to claim 1, comprising the steps of:

firstly, sequentially adding modified graphene, titanium dioxide and talcum powder into modified acrylic emulsion, heating to 80-90 ℃, dispersing at a high speed of 1000r/min at constant temperature for 25-30min at 800-;

secondly, adding the thickening agent, the dispersing agent and the coupling agent in the auxiliary agent into 1/3-volume deionized water, stirring and mixing uniformly, adding into the premix, dispersing for 10-12min at the speed of 400-500r/min, adding the antirust additive, and continuously dispersing for 8-10 min;

and step three, finally adding a film forming auxiliary agent and a defoaming agent, adding the rest deionized water, and dispersing for 15-17min at the speed of 200-300r/min to prepare the anticorrosive coating.