CN105602416A - VCI (volatile corrosion inhibitor) powder metallic finishing coating and preparation method thereof - Google Patents

Abstract

The invention provides a kind of VCI powder metal topcoat, which is characterized in that: it comprises the following components in parts by weight: including base material, filler, VCI vapor phase corrosion inhibitor and auxiliary agent; the base material includes 30 to 50 parts Polyester powder resin, 5-15 parts of polytetrafluoroethylene resin, 3-5 parts of curing agent; the filler includes 1-5 parts of flake aluminum powder or pearl powder, 20-40 parts of barium sulfate; The auxiliary agent is one or more of a leveling agent, a conductive agent, a degassing agent, and a light stabilizer; the mass ratio of the base material to the filler is 3:1 to 2:3; the VCI gas phase corrosion inhibitor The mass of the agent is 5-10 parts of the total mass of the base material and the filler; the mass of the auxiliary agent is 2-10 parts of the total mass of the base material and the filler. The coating has a good shielding effect and also has the corrosion inhibition effect of VCI vapor phase corrosion inhibitor, so as to achieve an excellent protection effect on metal substrates. At the same time, the invention has excellent decoration and weather resistance.

Description

VCI powder metal topcoat paint and preparation method thereof

technical field

The invention belongs to the field of coatings, in particular to a VCI powder metal finish coating.

Background technique

Hot-dip galvanizing is also called hot-dip galvanizing. It is to immerse the rust-removed steel components in a zinc solution melted at a high temperature of about 600 ° C, so that the surface of the steel components is attached with a zinc layer. The above thick plate is not less than 86μm. As an effective metal anti-corrosion method, hot-dip galvanizing process has been widely used in metal structure facilities in various industries.

The existing hot-dip galvanizing construction technology is shown in Figure 1. However, the existing hot-dip galvanizing construction technology has many defects:

(1) The pickling process uses 20% hydrochloric acid, which will produce a large amount of acid waste liquid. The activation and exposure treatment stages use ZnCl2 and NH4Cl solutions, which will generate a large amount of industrial wastewater. If they are directly discharged, they will cause damage to water resources and soil resources. Severe pollution and high cost of wastewater treatment;

(2) A large amount of coal resources need to be consumed in the process to maintain the temperature of the zinc bath, which results in a serious waste of energy. The temperature of the zinc bath needs to be maintained above 470°C for a long time, and the drying needs to be maintained at about 180°C, which not only consumes a lot of resources such as coal and natural gas, but also produces a lot of zinc vapor pollution. Taking a surface treatment plant as an example, the plant processes about 50,000 tons of bridges every year, requires about 55 kg of coal per ton, and emits 2,620 kg of carbon dioxide per ton of standard coal combustion. It can be known that the annual carbon emissions of the plant are about 7,205 tons (this data is not Including the coal consumed to maintain the zinc tank during non-working hours), which belongs to the high carbon emission industry.

(3) The construction process is complex and the construction environment is harsh. During the construction process, a large amount of waste gas and waste liquid are generated, and the treatment is difficult, causing pollution to the surrounding environment.

(4) Serious waste of zinc resources. Metal zinc is a non-renewable resource, and the amount of metal zinc material used in this process is large, and the performance of the obtained coating is average.

Therefore, the anticorrosion of existing steel components is usually achieved by zinc-rich coatings. The anti-corrosion coating of indoor and outdoor steel structures generally uses zinc-rich paint as the primer, compound intermediate paint and top paint. Its anti-corrosion performance mainly uses the cathodic protection effect of zinc-rich primer; Good features.

Zinc-rich coatings include inorganic zinc-rich coatings and organic zinc-rich coatings, and inorganic zinc-rich coatings include water-based inorganic zinc-rich coatings and alcohol-soluble inorganic zinc-rich coatings. This kind of coating has an electrochemical protective effect on steel, and has excellent antirust performance; it is resistant to seawater, oil, salt, atmospheric corrosion, good electrical conductivity, and does not affect welding construction. Inorganic zinc-rich coatings can be used in high-temperature environments above 400°C for a long time; organic zinc-rich coatings can be used as primers for heavy-duty anti-corrosion coatings, such as "epoxy zinc-rich primer + epoxy miracic iron paint + chlorinated rubber topcoat" The supporting system of heavy-duty anti-corrosion coatings has a service life of up to 7-15 years. Therefore, more and more zinc-rich coatings are used as anti-corrosion coatings for anti-corrosion measures such as ships, offshore oil production facilities, thermal pipelines, bridges, petrochemical equipment pipelines, and elevated iron towers at home and abroad.

However, in recent years, due to the increasingly serious environmental pollution, the state has become more and more vigorous in environmental governance. Traditional organic zinc-rich coatings contain a large amount of harmful solvents such as benzene, xylene, and butyl acetate, which seriously restricts the development of such coatings. Waterborne inorganic zinc-rich coatings are favored by the market due to their low VOC content. However, due to the characteristics of water-based inorganic zinc-rich coatings, the requirements for the pretreatment of the substrate are relatively high (Sa2.5 level), and the flexibility of the coating is poor. limit. Although alcohol-soluble inorganic zinc-rich coatings solve the problems of flexibility and high pretreatment requirements of water-based inorganic zinc-rich coatings to a certain extent, they also face the development problem of organic zinc-rich coatings due to their high VOC content.

In recent years, the environmental friendliness and energy saving and emission reduction advantages of powder coatings have become increasingly prominent, and the industry is facing good development opportunities. As a solvent-free coating, powder coating conforms to the internationally popular "four E" principles (economy, environmental protection, high efficiency, and excellent performance), and is welcomed by people. Its characteristics are as follows:

Simple process: powder coating is a technology that uses an electrostatic generator to charge powder particles, evenly adsorbs them on the metal substrate, and then transforms them into a hard protective coating through high-temperature melting and curing. The investment is small and the coating process is simple and convenient. ;

Cleanliness: Powder coatings are solvent-free, an undeniable benefit for the world's growing environmental awareness. At the same time, the powder coating sprayed on the floor can be recycled and reused. When spraying, it is supplemented by a cyclone dust collector or a filter bag remover, making the powder coating the cleanest coating variety at present, and it can be 100% environmentally friendly.

Economical: The powder coating is 100% solid, which means that the coating is formed almost 100% without any loss, and the required thickness can be achieved at one time when spraying, without spraying several layers.

Efficient: Powder coating has excellent mechanical properties, especially its impact resistance, flexibility and surface hardness, excellent anti-corrosion performance and chemical resistance (acids, alkalis, solvents, etc.) performance, used for outdoor series products It also has high weather resistance and can provide good protection for the substrate under harsh weather conditions.

Both the "Eleventh Five-Year Development Plan for the Coatings Industry" and the Medium and Long-term Development Plan for Science and Technology of the Coatings Industry clearly stated that it is necessary to vigorously develop environmentally friendly powder coatings. In the next 10 years, my country will significantly reduce the proportion of traditional solvent coatings in industrial coatings, reducing its share from the current 50% to 5%. The market share of powder coatings will increase from the current 18% to 40%, and it will take 10 to 15 years to implement new technology grafting and transformation to the traditional coatings industry, eventually reducing the market share of traditional solvent coatings to less than 1%. These plans provide opportunities for the development of environmentally friendly powder coatings. In the future, environmentally friendly coatings including water-based coatings and powder coatings will gradually replace traditional solvent-based coatings and become the leading products in the market.

There are many varieties of powder coatings, including products with various colors, various art textures and high-gloss, matte and other effects. Resin types include epoxy polyester (mixed) type, epoxy type, polyester type, polyurethane type and other series of products, and the varieties are basically comparable to solvent-based industrial anti-corrosion coatings. However, because powder coatings do not have the electrochemical cathodic protection effect of zinc-rich coatings, powder coatings must be combined with hot-dip galvanizing, electro-galvanizing or other cathodic protection systems when they are applied in the field of heavy-duty corrosion protection, which not only increases the project cost but also Caused a great waste of resources.

Contents of the invention

Technical problem: In order to solve the defects of the prior art, the present invention provides a kind of VCI powder metal finish coating.

Technical solution: The present invention provides a VCI powder metal finish coating, which includes the following components in parts by weight: base material, filler, VCI vapor phase corrosion inhibitor and auxiliary agent; the base material includes 30 to 50 parts of poly Ester powder resin, 5-15 parts of polytetrafluoroethylene resin, 3-5 parts of curing agent (TGIC); the filler includes 1-5 parts of flake aluminum powder or pearl powder, 20-40 parts of barium sulfate ; The auxiliary agent is one or more of a leveling agent, a conductive agent, a degassing agent, and a light stabilizer; the mass ratio of the base material to the filler is 3:1 to 2:3; the VCI gas phase The mass of the corrosion inhibitor is 5-10% of the total mass of the base material and the filler; the mass of the auxiliary agent is 2-10% of the total mass of the base material and the filler.

Preferably, the leveling agent is one or more of polyethyl propionate, butyl acetate, dimethyl polysiloxane, and polyvinyl butyral.

As another preference, the conductive agent is non-metallic powder, preferably graphite or amorphous carbon black.

As another preference, the degassing agent is one or more of benzoin, derivatives of hydrogenated castor oil, and bisamide wax.

As another preference, the light stabilizer is one or more of polysuccinate, benzophenone, and oxalanilide.

The present invention also provides the preparation method of above-mentioned VCI powder metal finish coating, comprises the following steps:

(1) Add polyester powder resin, polytetrafluoroethylene resin, curing agent, and auxiliary agent into a high-speed mixer, mix and crush to obtain a uniform mixture;

(2) Add the mixture prepared in step (1) into the extruder, and melt and extrude; extrusion temperature: front temperature 80°C-100°C, post-temperature 110°C-130°C;

(3) Rolling the hot-melt substance extruded by the extruder in step (2) through the pressure roller of the tablet press to form a strip with a thickness of 1 to 2 mm, which is broken into sheet materials after cooling;

(4) Repeat step (1) to step (3) for 1 to 3 times with the flake material obtained in step (3), and then add the obtained product into a mill for fine grinding; sieve;

(5) Put flake aluminum powder or pearl powder, barium sulfate and the product sieved in step (4) into a binding machine for binding treatment; binding parameters are: initial mixing temperature is room temperature; The initial binding temperature is 50°C to 70°C; the temperature rises for 3 minutes to 8 minutes until the maximum binding temperature is 75°C to 95°C; the cooling time is 10 minutes to 20 minutes until the discharge temperature is 20°C to 40°C;

(6) Sieve to get it.

Beneficial effects: the VCI powder metal topcoat provided by the invention not only has the good shielding effect of the powder coating, but also has the corrosion inhibition effect of the VCI vapor phase corrosion inhibitor, thereby achieving an excellent protective effect on the metal substrate. The invention adopts the process of mixing different weather-resistant resins, so that this type of powder coating has better weather resistance than ordinary powder coatings. In addition, the present invention adds aluminum powder or pearlescent powder through the method of binding, which increases the light reflection effect of the coating, and at the same time makes the coating obtained by the powder coating have a more excellent appearance effect, and improves the decoration and weather resistance of the coating itself .

VCI is the English abbreviation of Vapor Corrosion Inhibitor (Volatile Corrosion Inhibitor), which is a kind of corrosion inhibitor prepared by special synthesis process and compounding. It can be directly vaporized alone or attached to a suitable carrier at normal temperature and pressure; in a sealed environment, through self-adjustable continuous volatilization, any space gap in the working unit will be filled with a mixture containing VCI antirust factors Gas, when this gas encounters the metal surface, it will adsorb on it, forming a dense protective film layer with only one or several molecules thick; this protective film layer can effectively isolate the metal surface from contact with moisture, oxygen and other harmful atmospheric corrosion factors, Inhibit the occurrence of electrochemical reactions that promote metal corrosion, so as to achieve the best anti-corrosion effect.

The synergy between flake aluminum powder and VCI in the present invention, because the flake filler has a good shielding effect, when the VCI molecule is slowly released, the parallel overlapping structure of the flake filler provides a closed film for it, It can significantly reduce the dispersion velocity of VCI molecules, thus playing a good corrosion inhibition effect on metal substrates.

Specifically, the VCI powder metal finish paint provided by the invention has the following outstanding advantages:

1. The anti-rust effect is comprehensive. Regardless of whether the metal surface is regular or not, it can prevent corrosion in all directions without leaving any dead corners.

2. Long anti-rust period. Generally 2-5 years, after special treatment, it can reach more than 10 years.

3. The monomolecular protective layer formed after VCI gasification will not damage the material of metal products, without any side effects.

4. Excellent rust resistance. Even in a high-temperature, high-humidity, high-salt high-corrosion atmospheric environment like ocean transportation, it can protect the metal to be protected from corrosion.

5. Sanitation, safety and environmental protection. It will not harm the human body and will not cause environmental pollution.

Description of drawings

Figure 1 is a schematic diagram of the existing hot-dip galvanizing construction process.

detailed description

The raw materials used in the present invention are shown in Table 1.

The raw material used in the present invention of table 1

The VCI powder metal finish paint of the present invention is further described below.

Example 1

VCI powder metal finish paint, comprises the component of following parts by weight: comprises base material, filler, VCI vapor phase corrosion inhibitor and auxiliary agent; Described base material comprises 30 parts of polyester powder resins, 15 parts of polytetrafluoroethylene resins, 3 parts of curing agent (TGIC); the filler includes 1 part of flake aluminum powder or pearl powder, 40 parts of barium sulfate; the auxiliary agent is one of leveling agent, conductive agent, degassing agent, and light stabilizer or several; the mass ratio of the base material to the filler is 3:1; the quality of the VCI vapor phase corrosion inhibitor is 10% of the total mass of the base material and the filler; the quality of the auxiliary agent is the total mass of the base material and the filler 2% of mass.

The leveling agent is polyethyl propionate, butyl acetate, dimethyl polysiloxane, polyvinyl butyral; the conductive agent is graphite or amorphous carbon black; the degassing agent is benzoin, bisamide wax; the light The stabilizer is polysuccinate.

Its preparation method comprises the following steps:

(1) Add polyester powder resin, polytetrafluoroethylene resin, curing agent, and auxiliary agent into a high-speed mixer, mix and crush to obtain a uniform mixture;

(2) Add the mixture prepared in step (1) into the extruder, and melt and extrude; extrusion temperature: the front temperature is 80°C, and the back temperature is 110°C;

(3) Rolling the hot-melt substance extruded by the extruder in step (2) through the pressure roller of the tablet press to form a strip with a thickness of 1 to 2 mm, which is broken into sheet materials after cooling;

(4) Repeat step (1) to step (3) for 1 to 3 times with the flake material obtained in step (3), and then add the obtained product into a mill for fine grinding; sieve;

(5) Put flake aluminum powder or pearl powder, barium sulfate, and the product sieved in step (4) into a binding machine for binding; the binding parameters are: the initial mixing temperature is room temperature; Set the temperature at 50°C; heat up for 3 minutes until the highest binding temperature is 75°C; cool for 10 minutes until the discharge temperature is 20°C;

(6) Sieve to get it.

Example 2

VCI powder metal topcoat paint, comprises the component of following parts by weight: comprises base material, filler, VCI vapor phase corrosion inhibitor and auxiliary agent; Described base material comprises 50 parts of polyester powder resins, 5 parts of polytetrafluoroethylene resins, 5 parts of curing agent (TGIC); the filler includes 5 parts of flaky aluminum powder or pearl powder, 20 parts of barium sulfate; the auxiliary agent is one of leveling agent, conductive agent, degassing agent, and light stabilizer or several; the mass ratio of the base material to the filler is 2:3; the quality of the VCI vapor phase corrosion inhibitor is 5% of the total mass of the base material and the filler; the quality of the auxiliary agent is the total mass of the base material and the filler. 10% of the mass.

The leveling agent is polyethyl propionate, butyl acetate, dimethyl polysiloxane, polyvinyl butyral; the conductive agent is graphite or amorphous carbon black; the degassing agent is benzoin, bisamide wax; the light The stabilizer is benzophenone.

Its preparation method comprises the following steps:

(1) Add polyester powder resin, polytetrafluoroethylene resin, curing agent, and auxiliary agent into a high-speed mixer, mix and crush to obtain a uniform mixture;

(2) Add the mixture prepared in step (1) into the extruder, and melt and extrude; extrusion temperature: the front temperature is 100°C, and the back temperature is 130°C;

(3) Rolling the hot-melt substance extruded by the extruder in step (2) through the pressure roller of the tablet press to form a strip with a thickness of 1 to 2 mm, which is broken into sheet materials after cooling;

(4) Repeat step (1) to step (3) for 1 to 3 times with the flake material obtained in step (3), and then add the obtained product into a mill for fine grinding; sieve;

(5) Put flake aluminum powder or pearl powder, barium sulfate and the product sieved in step (4) into a binding machine for binding; the binding parameters are: initial mixing temperature is room temperature; heat up for 3 minutes to start binding The temperature is 70°C; heat up for 8 minutes until the highest binding temperature is 95°C; cool for 20 minutes until the discharge temperature is 40°C;

(6) Sieve to get it.

Example 3

VCI powder metal finish paint, comprises the component of following parts by weight: comprises base material, filler, VCI vapor phase corrosion inhibitor and auxiliary agent; Described base material comprises 40 parts of polyester powder resins, 10 parts of polytetrafluoroethylene resins, 4 parts of curing agent (TGIC); the filler includes 3 parts of flake aluminum powder or pearl powder, 30 parts of barium sulfate; the auxiliary agent is one of leveling agent, conductive agent, degassing agent, and light stabilizer or several; the mass ratio of the base material and the filler is 1:1; the quality of the VCI vapor phase corrosion inhibitor is 7% of the total mass of the base material and the filler; the quality of the auxiliary agent is the total mass of the base material and the filler. 6% of mass.

The leveling agent is polyethyl propionate, butyl acetate, dimethyl polysiloxane, polyvinyl butyral; the conductive agent is graphite or amorphous carbon black; the degassing agent is benzoin, bisamide wax; the light The stabilizer is oxalanilide.

Its preparation method comprises the following steps:

(1) Add polyester powder resin, polytetrafluoroethylene resin, curing agent, and auxiliary agent into a high-speed mixer, mix and crush to obtain a uniform mixture;

(2) Add the mixture prepared in step (1) into the extruder, and melt and extrude; extrusion temperature: front temperature 90°C, back temperature 120°C;

(3) Rolling the hot-melt substance extruded by the extruder in step (2) through the pressure roller of the tablet press to form a strip with a thickness of 1 to 2 mm, which is broken into sheet materials after cooling;

(4) Repeat step (1) to step (3) for 1 to 3 times with the flake material obtained in step (3), and then add the obtained product into a mill for fine grinding; sieve;

(5) Put flake aluminum powder or pearl powder, barium sulfate, and the product sieved in step (4) into a binding machine for binding; the binding parameters are: the initial mixing temperature is room temperature; Set the temperature at 60°C; heat up for 5 minutes until the highest binding temperature is 85°C; cool for 15 minutes until the discharge temperature is 30°C;

(6) Sieve to get it.

Test the performance of the VCI powder metal finish paint of Examples 1 to 3, and the results are shown in Table 2.

The VCI powder metal finish paint performance of table 2 embodiment 1 to 3

Salt spray test time h UV aging resistance time h Adhesion (cross-cut method) commercially available powder 500 300～500h Level 1 Example 1 Coating ≥3000h ≥800h Level 1 Example 2 coating ≥3000h ≥800h Level 1 Example 3 Coating ≥3000h ≥800h Level 1

Claims (6)

1. a VCI powdered-metal finish paint coating, is characterized in that: the component that comprises following weight portion: comprise base-material, fill outMaterial, VCI vapour phase inhibitor and auxiliary agent; Described base-material comprises 30 parts～50 parts polyester powder resins, 5 parts～15 partsPolyflon, 3 parts～5 parts curing agent (TGIC); Described filler comprises 1 part～5 parts flake aluminums or pearlLight powder, 20 parts～40 parts barium sulfate; Described auxiliary agent is one in levelling agent, conductive agent, degasser, light stabilizerKind or several; The mass ratio of described base-material, filler is 3:1～2:3; The quality of described VCI vapour phase inhibitor is base-materialWith 5～10% of filler gross mass; The quality of described auxiliary agent is 2～10% of base-material and filler gross mass.

2. a kind of VCI powdered-metal finish paint coating according to claim 1, is characterized in that: described levelling agent is for poly-One or more in ethyl propionate, butyl acetate, dimethyl polysiloxane, polyvinyl butyral.

3. a kind of VCI powdered-metal finish paint coating according to claim 1, is characterized in that: described conductive agent is non-Metal dust, preferably graphite or amorphous carbon black.

4. a kind of VCI powdered-metal finish paint coating according to claim 1, is characterized in that: described degasser is peaceOne or more in derivative, the bisamide wax of breath perfume, rilanit special.

5. a kind of VCI powdered-metal finish paint coating according to claim 1, is characterized in that: described light stabilizer isOne or more in poly-succinic ester, benzophenone, oxanilide.

6. the preparation method of the VCI powdered-metal finish paint coating described in claim 1 to 5 any one, is characterized in that: bagDraw together following steps:

(1) polyester powder resin, polyflon, curing agent and auxiliary agent are joined in high-speed mixer, mixedMerge fragmentation, obtain uniform mixture;

(2) mixture step (1) being made joins in extruder, melt extrudes; Extrusion temperature: front temperature80 DEG C～100 DEG C, 110 DEG C～130 DEG C of rear temperature;

(3) heat of step (2) extruder being extruded is melted state material through the roll extrusion of tablet press machine pressure roller, forms 1～2mm thickThe ribbon of degree, is broken into sheet material after cooling;

(4) the sheet material repeating step (1) step (3) being made to after step (3) 1～3 times by the product obtainingAdd and in flour mill, carry out fine grinding; Sieve;

(5) product of flake aluminum or pearl essence, barium sulfate and step (4) screening is placed in to binding place of binding machineReason; Binding parameter is: initial mixing temperature is room temperature; Intensification 0.5min～3min is 50 DEG C to starting to bind temperature～70 DEG C; Intensification 3min～8min extremely the highest binding temperature is 75 DEG C～95 DEG C; Cooling 10min～20min is to going out material temperatureDegree is 20 DEG C～40 DEG C;

(6) sieve, to obtain final product.