1. A protective coating for galvanized materials is characterized in that: comprises a component A and a component B;

the component A comprises the following components in parts by mass: 50-65 parts of acrylic resin, 10-15 parts of cellulose resin, 0.2-2 parts of a nano corrosion-resistant material, 0.2-2 parts of a nano graphene liquid, 10-20 parts of a pigment and filler, 1-20 parts of glass beads, 5-20 parts of a first solvent and 0.2-8 parts of an auxiliary agent;

the component B is 20-25 parts by mass of an isocyanate curing agent;

the acrylic resin comprises at least one of hydroxyl acrylic resin, carboxyl acrylic resin and epoxy acrylic resin; the auxiliary agent comprises at least one of a thickening agent, a toughening agent, an arrangement agent, a flatting agent and a wetting dispersing agent.

2. The protective coating for galvanized materials according to claim 1, characterized in that: the cellulose resin is nitrocellulose resin.

3. The protective coating for galvanized materials according to claim 1, characterized in that: the nano corrosion-resistant material comprises at least one of nano silver powder, nano titanium dioxide powder, nano carbon powder and nano antirust agent.

4. The protective coating for galvanized materials according to claim 1, characterized in that: the nano graphene liquid comprises the following components in parts by mass: 2-10 parts of nano graphene, 1-3 parts of a stabilizer, 0.5-2 parts of a dispersant and 85-100 parts of a second solvent.

5. The protective coating for galvanized materials according to claim 1, characterized in that: the pigment and filler comprises at least one of resin-coated aluminum paste, silicon dioxide-coated silver and silver powder.

6. The protective coating for galvanized materials according to claim 1, characterized in that: the glass beads are vacuum aluminized glass beads.

7. The protective coating for a galvanized material according to any one of claims 1 to 6, characterized in that: the protective coating for the galvanized material further comprises 5-20 parts by mass of a diluent.

8. A method for preparing the protective coating of the galvanized material according to claim 7, which is characterized in that: the method comprises the following steps:

preparation of first and second components

S11: mixing acrylic resin, a thickening agent, a toughening agent and glass beads to obtain a component A;

s12: mixing cellulose resin, nano graphene liquid, pigment and filler, a first solvent, a arraying agent and a leveling agent, and grinding and dispersing to obtain a component B;

s13: mixing and dispersing the wetting dispersant and the nano corrosion-resistant material to obtain a component C;

s14: mixing the A, B, C components to obtain a component A;

or the following steps:

s21: mixing and dispersing acrylic resin, cellulose resin, a nano corrosion-resistant material, nano graphene liquid, pigment and filler, glass beads, a first solvent and an auxiliary agent to obtain a component A;

secondly, preparation of protective coating of zinc-plated material

And (3) taking an isocyanate curing agent as a component B, mixing with the component A, and then adding a diluent for mixing to obtain the protective coating for the galvanized material.

9. The method of claim 8, wherein: the preparation method of the nano graphene liquid comprises the following steps: and mixing the nano reduced graphene, the stabilizer, the dispersant and the second solvent, and grinding.

10. Use of the protective coating of a galvanized material according to any one of claims 1 to 7 in the surface treatment of galvanized protective barriers.

Background

The highway guardrail is a main form of a semi-rigid guardrail and is a continuous structure formed by mutually splicing corrugated steel guardrail plates and supporting the corrugated steel guardrail plates by a main column. The vehicle can absorb energy when colliding, is not easy to be collided, and can well protect the vehicle and the driver and passengers.

The surface treatment of the highway guardrail can be divided into hot galvanizing and galvanized plastic spraying; the galvanization can be divided into hot galvanizing and cold galvanization: the hot galvanizing is to dip the steel member after rust removal into zinc liquid at 500 ℃ to make the surface of the steel member adhere with a zinc layer, thereby achieving the purpose of corrosion resistance. Cold galvanizing, also called electrogalvanizing, is to use electrolytic equipment to remove oil and acid from the pipe fitting, then put the pipe fitting into a solution containing zinc salt as a component, and deposit zinc on the surface of the steel member by electroplating, so that the zinc layer is thinner, the anti-corrosion and anti-rust effects are inferior to those of hot galvanizing, the protection period is shorter, the scratch-resistant effect is inferior, but the cost is relatively low, and the appearance is relatively bright. The spraying plastic is also called as electrostatic powder spraying, and is characterized in that an electrostatic generator is used for carrying points on plastic powder, the plastic powder is adsorbed on the surface of a steel piece, and then the plastic powder is roasted at 220 ℃ by 180 ℃ so that the powder is melted and adhered on the surface of metal.

The highway protection facilities are in a severe outdoor environment and are subjected to the effects of sunlight exposure, weather erosion, thermal expansion and cold contraction, automobile exhaust and acid rain salt fog, in the using process, a zinc layer is worn, loses light and corrosion resistance, the appearance decoration performance is reduced, the protection and warning capacity of the guardrail is reduced, and generally, after the service life, most of the highway protection facilities are dismantled and replaced. The old guardrail returns to the factory for renovation, which causes the cost of secondary demolition and installation, the cost of manual renovation treatment and transportation. The surface adhesion of the retreading paint in the current market can not meet the technical requirements, the retreading paint has poor corrosion resistance, poor adhesion, easy shedding and poor antifouling capacity, does not have the field retreading maintenance function, and has no large-area popularization value. So far, no successful case of applying the nano graphene self-cleaning anticorrosion protection technology to the galvanized component exists.

In the prior art, the same solvent type coating and water-based coating have the defects of poor capability of being adhered to a galvanized high-speed guardrail plate, high temperature difference in north and south climates, easy cracking and paint removal, poor pollution resistance, poor corrosion resistance and the like, and short service life. The powder coating has the disadvantages of poor dirt resistance, incapability of on-site coating and maintenance, high energy consumption, high maintenance cost and the like. The hot-melt plastic coating has poor corrosion resistance, artificial aging resistance can not meet the requirement, the hot-melt plastic coating is easy to pulverize and discolor within two years, field coating and maintenance can not be performed, the energy consumption is high, and the maintenance cost is high. The water-based paint can not be applied in winter transportation and construction drying in the north, and the adhesion capability on galvanized parts is yet to be observed.

Disclosure of Invention

In order to overcome the problems of the prior art, the invention aims at providing a galvanized material protective coating, aims at providing a preparation method of the galvanized material protective coating, and aims at providing application of the galvanized material protective coating.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the invention provides a galvanized material protective coating in a first aspect, which comprises a component A and a component B;

the component A comprises the following components in parts by mass: 50-65 parts of acrylic resin, 10-15 parts of cellulose resin, 0.2-2 parts of a nano corrosion-resistant material, 0.2-2 parts of a nano graphene liquid, 10-20 parts of a pigment and filler, 1-20 parts of glass beads, 5-20 parts of a first solvent and 0.2-8 parts of an auxiliary agent;

the component B is 20-25 parts by mass of an isocyanate curing agent;

the acrylic resin comprises at least one of hydroxyl acrylic resin, carboxyl acrylic resin and epoxy acrylic resin;

the auxiliary agent comprises at least one of a thickening agent, a toughening agent, an arrangement agent, a flatting agent and a wetting dispersing agent.

Preferably, in the protective coating for a zinc-plated material, the cellulose resin is a nitrocellulose resin. In some embodiments of the invention, an Istman nitrocellulose resin may be used.

Preferably, in the protective coating for the galvanized material, the nano corrosion-resistant material comprises at least one of nano silver powder, nano titanium dioxide powder, nano carbon powder and nano antirust agent.

Preferably, in the protective coating for a zinc-plated material, the first solvent is at least one selected from the group consisting of propylene glycol methyl ether acetate (PMA), Xylene (XYL), Butyl Acetate (BAC), diacetone alcohol (DAA), dibasic ester (DBE), dimethyl phthalate (DMP), and high boiling aromatic hydrocarbon solvent S-100 #.

Preferably, in the protective coating for the galvanized material, the nano graphene liquid comprises the following components in parts by mass: 2-10 parts of nano graphene, 1-3 parts of a stabilizer, 0.5-2 parts of a dispersant and 85-100 parts of a second solvent; further preferably, the nano graphene liquid comprises the following components in parts by mass: 3-5 parts of nano graphene, 1-3 parts of a stabilizer, 0.5-2 parts of a dispersant and 90-95 parts of a second solvent.

Preferably, in the nano-graphene liquid, the nano-graphene is at least one selected from reduced graphene, oxidized graphene and physically exfoliated graphene.

Preferably, in the nano graphene liquid, the stabilizer may be selected from KYC 913.

Preferably, in the nano graphene liquid, the dispersant is a nano hydrophobic dispersant; further preferably, the dispersant may be selected from BKY 2150.

Preferably, in the nano graphene liquid, the second solvent is at least one of an ester solvent, an alcohol solvent, a ketone solvent and an ether solvent; further preferably, the second solvent is an ester solvent; still more preferably, the second solvent is at least one selected from the group consisting of ethyl acetate, propylene glycol methyl ether acetate, butyl acetate, dibasic ester, and dimethyl phthalate.

Preferably, in the galvanized material protective coating, the pigment and filler is at least one selected from resin-coated aluminum silver paste, silicon dioxide-coated silver and silver powder.

Preferably, in the protective coating for the galvanized material, the glass beads are vacuum aluminized glass beads.

Preferably, in the protective coating for the galvanized material, when the auxiliary agent comprises the thickening agent, the mass part of the thickening agent is 0.2-2 parts.

Preferably, the thickener is at least one selected from the group consisting of organobentonite, attapulgite, fumed silica, and polyamide wax.

Preferably, in the protective coating for the galvanized material, when the auxiliary agent comprises the toughening agent, the mass part of the toughening agent is 0.2-2 parts.

Preferably, the toughening agent is selected from at least one of dibutyl phthalate (DBP), dimethyl phthalate (DMP), dioctyl phthalate (DOP), epoxidized soybean oil, and chlorinated paraffin.

Preferably, in the protective coating for the galvanized material, when the auxiliary agent comprises the aligning agent, the mass part of the aligning agent is 0.2-2 parts.

Preferably, the aligning agent is selected from at least one of aralkyl modified silicone, polyethylene wax and polyamide wax; further preferably, the aligning agent is at least one selected from BYK-323, DC-56, polyethylene wax, 6900-20X.

Preferably, in the protective coating for the galvanized material, when the auxiliary agent comprises a leveling agent, the mass part of the leveling agent is 0.2-2 parts.

Preferably, the leveling agent is at least one selected from an acrylic leveling agent, an organic silicon leveling agent and a fluorocarbon leveling agent.

Preferably, in the protective coating for the galvanized material, when the auxiliary agent comprises the wetting dispersant, the mass part of the wetting dispersant is 0.2-2 parts.

Preferably, the wetting dispersant is at least one selected from BYK108, BYK110, BYK118, BYK162, BYK180, BKY190, BKY191, BKY192, BKY193, BYK2050, TEGO760W and TEGO 757W.

Preferably, in the galvanized material protective coating, the auxiliary agents comprise a thickening agent, a toughening agent, an alignment agent, a leveling agent and a wetting dispersing agent.

Preferably, the protective coating for the galvanized material also comprises 5-20 parts by mass of a diluent.

Preferably, in the galvanized material protective coating, the diluent is a non-aromatic hydrocarbon diluent; further preferably, the diluent is at least one selected from the group consisting of an ether solvent, an ester solvent, a ketone solvent and an alcohol solvent; still more preferably, the diluent is at least one selected from the group consisting of ethylene glycol butyl ether, ethylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol methyl ether acetate, n-propyl acetate, ethyl acetate, butyl acetate, methyl ethyl ketone, cyclohexanone, ethanol, and n-butanol.

Preferably, in the galvanized material protective coating, the isocyanate curing agent is Hexamethylene Diisocyanate (HDI). HDI can be selected from at least one of N3390, N3300, HXR, N75, HXR90B, 22-75PXHT-100, HI-190, TPA-100.

The second aspect of the present invention provides a method for preparing the protective coating for the galvanized material according to the first aspect of the present invention, comprising the following steps:

preparation of first and second components

S11: mixing acrylic resin, a thickening agent, a toughening agent and glass beads to obtain a component A;

s12: mixing cellulose resin, nano graphene liquid, pigment and filler, a first solvent, a arraying agent and a leveling agent, and grinding and dispersing to obtain a component B;

s13: mixing and dispersing the wetting dispersant and the nano corrosion-resistant material to obtain a component C;

s14: mixing the A, B, C components to obtain a component A;

or the following steps:

s21: mixing and dispersing acrylic resin, cellulose resin, a nano corrosion-resistant material, nano graphene liquid, pigment and filler, glass beads, a first solvent and an auxiliary agent to obtain a component A;

secondly, preparation of protective coating of zinc-plated material

And (3) taking an isocyanate curing agent as a component B, mixing with the component A, and then adding a diluent for mixing to obtain the protective coating for the galvanized material.

Preferably, in the preparation method of the protective coating for the zinc-plated material, the preparation method of the nano graphene liquid is as follows: and mixing the nano reduced graphene, the stabilizer, the dispersant and the second solvent, and grinding.

Preferably, in the step S11, the mixing is carried out at a rotation speed of 500 r/min-700 r/min for 80 min-100 min.

Preferably, in the step S12, the mixing is carried out at a rotation speed of 300 r/min-500 r/min for 80 min-100 min.

Preferably, in the step S12, the component A is ground and dispersed until the fineness of the material is less than or equal to 50 nm.

Preferably, in the step S13, the component A is mixed and dispersed until the fineness of the material is less than or equal to 50 nm.

Preferably, in the step S14, the mixing is carried out at a rotation speed of 500 r/min-700 r/min for 20 min-40 min.

Preferably, in the step S21, the mixing and dispersing are carried out at a rotation speed of 800 r/min-1000 r/min for 80 min-100 min.

Preferably, in the step S21, the component A is mixed and dispersed until the fineness of the material is less than or equal to 50 nm.

Preferably, in the step of preparing the protective coating of the galvanized material, the mixing is carried out at the rotating speed of 300 r/min-500 r/min; wherein, the time for mixing and stirring with the component A is 5min to 15min, and the time for adding the diluent for mixing and stirring is 3min to 8 min.

Preferably, the preparation method of the nano graphene liquid comprises the following steps: and mixing the nano reduced graphene, the stabilizer, the dispersant and the second solvent, and grinding.

Preferably, in the preparation method of the nano graphene liquid, grinding is carried out until the fineness is less than or equal to 50 nm.

The third aspect of the present invention also provides the use of the galvanized protective coating according to the first aspect of the present invention in the surface treatment of a galvanized protective fence.

Preferably, in the application, the specific method is as follows: and spraying the protective coating of the galvanized material on the surface of the galvanized protective fence, and curing.

Preferably, in the application, the galvanized protective guard is a road galvanized protective guard; further preferably, the galvanized protective guard is a highway galvanized protective guard.

The invention has the beneficial effects that:

the protective coating disclosed by the invention is wear-resistant, anti-fouling and anti-freezing, has a self-cleaning function, is high-temperature resistant, ultraviolet aging resistant, high in glossiness of a paint film, excellent in performances such as rust prevention, hydrophobicity and antifouling, simple and easy to operate in coating spraying construction, low in maintenance cost, and not harsh in outdoor construction environment requirements. The protective coating is applied to the surface protection treatment of the galvanized protective guard of the expressway, obtains good effect and has wide application prospect.

Particularly, the protective coating of the galvanized material is prepared by adopting graphene as a raw material, the graphene is used as a novel two-dimensional material, the protective coating has excellent thermal stability, weather resistance, ageing resistance and mechanical strength, good shielding property is obtained, the nanometer small-size effect of the protective coating can effectively fill gaps of fillers, a labyrinth tunnel is formed in a coating, and the corrosion resistance of the coating is enhanced.

Detailed Description

The present invention will be described in further detail with reference to specific examples. The starting materials, reagents or equipment used in the examples are, unless otherwise specified, either conventionally commercially available or may be obtained by methods known in the art. Unless otherwise indicated, the testing or testing methods are conventional in the art.

In the following examples, the cellulose resin used was Istman nitrocellulose resin. The types of the raw materials used in examples 2 to 3 were the same as those used in example 1 unless otherwise specified.

Example 1

The protective coating for coating the surface of the galvanized material comprises the following components in parts by weight: 60g of hydroxy acrylic resin, 10g of cellulose resin, 1g of nano silver powder, 1.5g of nano graphene liquid, 10g of resin-coated aluminum paste, 8g of vacuum aluminized glass microspheres, 10g of BAC10g, 6g of PMA, 1g of acrylic leveling agent, 0.5g of thickening agent organic bentonite, 0.5g of toughening agent DBP0, 20g of arrangement agent BYK-3230.5 g, wetting dispersant BKY1900.2g, 20g of HDI isocyanate and 15g of diluent ethyl acetate.

The protective coating of the embodiment is prepared by the following method:

1) mixing reduced graphene powder, a high-molecular dispersion stabilizer KYC913, a nano hydrophobic small-molecular dispersant BYK2150 and BCA according to the mass percentage of 4%, 2%, 1% and 93%, and grinding the mixture to the fineness of 50nm under a nano sand mill to obtain nano graphene liquid for later use;

2) dispersing hydroxyl acrylic resin, a thickening agent, a toughening agent and vacuum aluminized glass beads for 90 minutes at the rotating speed of 600r/min to obtain a component A;

3) grinding and dispersing cellulose resin, PMA, BAC, an arrangement agent, nano silver powder, resin-coated aluminum silver paste and a leveling agent at the rotating speed of 400r/min for 90 minutes until the fineness is 50nm to obtain a component B;

4) mixing the wetting dispersant and the nano graphene liquid according to a ratio, and dispersing the mixture under a nano sand mill to obtain a component C with the nano fineness of 50 nm;

5) dispersing the A, B, C component for 30 minutes at the rotating speed of 600r/min to obtain a component A;

6) adding the HDI isocyanate of the component B into the component A, stirring for 10min at the rotating speed of 450r/min, adding the diluent, and continuously stirring for 5min to obtain the coating of the embodiment.

Example 2

The protective coating for coating the surface of the galvanized material comprises the following components in parts by weight: 60g of hydroxyl acrylic resin, 10g of cellulose resin, 1g of nano titanium dioxide powder, 1.5g of nano graphene liquid, 10g of resin-coated aluminum paste, 8g of vacuum aluminized glass microspheres, 4g of PMA, 10g of xylene, 1g of leveling agent, 1g of thickening agent, 0.5g of toughening agent, 0.5g of arrangement agent, 0.2g of wetting dispersant, 20g of HDI isocyanate and 15g of diluent.

The protective coating of the embodiment is prepared by the following method:

1) hydroxyl acrylic resin, cellulose resin, nano titanium dioxide powder, nano graphene liquid, resin-coated aluminum silver paste, vacuum aluminized glass beads, PMA, xylene, a leveling agent, a thickening agent, a toughening agent, a arraying agent and a wetting dispersant are mixed according to a ratio, and are dispersed for 90 minutes at a rotating speed of 900r/min until the fineness is 50nm, so that a component A is obtained.

2) Adding the HDI isocyanate of the component B into the component A, stirring for 10min at the rotating speed of 450r/min, adding the diluent, and continuously stirring for 5min to obtain the coating of the embodiment.

Example 3

The protective coating for coating the surface of the galvanized material comprises the following components in parts by weight: 60g of hydroxyl acrylic resin, 10g of cellulose resin, 10g of silver powder, 4.5g of nano graphene liquid, 10g of vacuum aluminized glass beads, 3g of PMA, 10g of xylene, 1g of flatting agent, 0.5g of thickening agent, 0.5g of toughening agent, 0.5g of aligning agent, 0.2g of wetting dispersant, 20g of HDI isocyanate and 15g of diluent.

The protective coating of the embodiment is prepared by the following method:

1) hydroxyl acrylic resin, cellulose resin, silver powder, nano graphene liquid, vacuum aluminized glass beads, PMA, xylene, a leveling agent, a thickening agent, a toughening agent, an arrangement agent and a wetting dispersant are mixed according to a ratio, and are dispersed for 90 minutes at a rotating speed of 900r/min until the fineness is 50nm, so that the component A is obtained.

2) And adding the HDI isocyanate of the component B into the component A, stirring at the rotating speed of 450r/min for 10min, adding the diluent, and continuously stirring for 5min to obtain the coating of the embodiment.

The coatings obtained in examples 1 to 3 were subjected to performance tests, and the test results are shown in table 1.

TABLE 1 test results for the coatings of examples 1-3

Application example

In 11 months in 2019, the paint prepared in example 1 is sprayed and cured on the surface of a galvanized protective guard of a highway on a certain section of the Shandong, and construction is carried out in sections. The construction test length is about 200 kilometers, the construction progress is 1.7 kilometers every day when the construction environment is sunny, and the thickness of a construction dry film is more than or equal to 35 micrometers. The indexes of field detection and evaluation are drying time, adhesive force and color difference. The test results are shown in table 2. The adhesion (Baige method) was determined using the method of GB/T9286-1998 standard and the drying time was determined according to GB/T1728-1989.

Table 2 coating application test results

Item	Test results
		Adhesion (Baige method)	Level 1
Drying time (watch dry)	30min
		Drying time (actual dry)	24h
Color difference Δ E	≤0.3
		Retroreflection performance (silver white)	8.4

From experimental results, the protective coating provided by the invention has the advantages of good comprehensive performance, simple and easy coating spraying construction operation, simple construction, low maintenance cost and no harsh outdoor construction environment requirement. The protective coating is applied to the surface protection treatment of the galvanized protective guard of the expressway, and a good application effect is achieved.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.