WO2021027368A1 - Polyurea coating acting against ocean engineering corrosion and preparation method therefor - Google Patents

Abstract

Disclosed is a polyurea coating acting against ocean engineering corrosion. The polyurea coating comprises a component A and a component B, wherein the component A comprises a polyisocyanate and a polycarbonate polyol, and the component B comprises an amine-terminated polyether, an amino chain extender, a modified nano titanium dioxide, a nanometer zinc oxide, a hydroxyamino carboxylic acid compound, an anti-foulant, an anti-rust pigment and an anti-settling agent. The raw materials for preparing the modified nano titanium dioxide comprises nano titanium dioxide, a surfactant, a silane coupling agent, silver nitrate and copper sulfate. The polyurea coating has a strong seawater and salt fog resistance, can resist microbial adhesion, and is suitable for acting against marine engineering corrosion.

Description

Marine engineering anticorrosive polyurea coating and preparation method thereof Technical field

The invention belongs to the technical field of marine engineering chemical coatings, and specifically relates to a marine engineering anticorrosive polyurea coating.

Background technique

The 21st century is the ocean century, and the ocean economy has gradually become a new growth point for our national economy. With the rapid rise of the marine industry, marine engineering equipment has become a new profit growth point for the world's major shipbuilding companies. The "Plan for the Adjustment and Revitalization of the Shipbuilding Industry" clearly requires the acceleration of independent innovation, the development of offshore equipment, and the gradual expansion of the market share of offshore equipment, focusing on the development of drilling platforms, production platforms, floating production and storage devices, engineering work ships, modules and oceans Engineering equipment supporting equipment. However, the use environment of marine engineering equipment is extremely harsh. Sun exposure, salt spray, wave impact, complicated seawater system, environmental temperature and humidity changes, and marine biological erosion make the corrosion rate of marine engineering equipment faster. At present, with the rapid development of ocean engineering technology, people are increasingly aware that the anti-corrosion of major equipment and parts in ocean engineering has become a top priority.

As we all know, most of the various structures and production facilities of ocean engineering are made of steel. As a large ocean engineering, these steel products need to be in the ocean atmosphere filled with salt mist for many years, or in the splash area of tides and waves. Seawater itself is a strong corrosive medium. At the same time, waves and tidal currents produce low-frequency reciprocating stress and impact on steel components. In addition, marine microorganisms, attached organisms and their metabolites all have direct or indirect accelerated corrosion effects on the corrosion process. . In such a harsh marine environment, the corrosion rate of metal is many times greater than that of land, and in the same marine environment, metal corrosion is the most serious in the splash zone. This shows that the reciprocating stress and impact of the seawater in the splash zone on the surface of the metal coating can easily cause the metal protective coating to shell and fall off and accelerate the corrosion rate.

It can be seen from the above-mentioned status that anti-corrosion in the field of marine engineering is a major task. However, looking at the entire field of marine anti-corrosion coatings in China, the types of anti-rust and anti-corrosion products are rare, and their functions are minimal. Therefore, research has marine anti-corrosion Functional coatings are of great significance.

Spraying polyurea elastomer technology is a new type of technology developed to meet environmental protection requirements after low (non) pollution coating technologies such as high-solid coatings, water-based coatings, light-curing coatings, powder coatings, etc. Solvent-free, pollution-free green construction technology. Since the technology was put into commercial application in my country in 1999, it has been widely used in the fields of steel structure anticorrosion, building waterproofing, and film and television props production.

The spraying polyurea elastomer technology organically combines the excellent performance of polyurea with rapid spraying and on-site curing construction technology, so that it shows unparalleled superiority in engineering applications. Compared with traditional coatings, spray polyurea elastomer materials have the characteristics of solvent-free, fast curing, insensitive to humidity and temperature, short construction period, and excellent high temperature and aging resistance. However, the current application of sprayed polyurea in the seawater and salt spray corrosion resistance environment has some shortcomings. For example, long-term immersion in seawater, the coating surface is prone to microbial adhesion, and microbial excrement will accelerate the corrosion of metal structures; the coating is resistant The cathodic stripping performance is not good, and it is easy to shell and fall off in the face of the reciprocating stress and impact of waves, tides, etc. on the coating surface; in the prior art, the salt spray resistance of commonly used polyurea coatings is generally ≤800 hours, such anti-corrosion Performance still cannot meet people's needs.

Patent document CN201810415159.8 discloses a polyurea coating and a preparation method thereof. The polyurea coating includes component A, component B, and nano-paste; the component A is prepared from raw materials including diisocyanate and polypropylene glycol Obtained; The B component includes polyoxypropylene diammonium, diethyl maleate, dispersant, leveling agent and defoaming agent; the nano slurry includes nano silica and accelerator; prepared polyurea Coatings and polyurea coatings have good wear resistance, adhesion and artificial accelerated aging performance, and the salt spray resistance is ≥1000 hours.

Patent document CN201810069538.6 discloses a multi-layer ultra-thick anti-corrosion coating for marine steel components, in which the protective coating has a three-layer structure, the bottom layer is a polypyrrole film polymerized on the surface of the steel by electrochemical polymerization, and the middle layer It is an epoxy coating, and the surface layer is one of polyurethane acrylic, epoxy acrylic, and polyurea coatings. The anticorrosive coating needs to adopt multiple coating processes to achieve a thickness of 410-1000 μm to realize a multi-layer ultra-thick protective coating system, but if the coating is too thick, it will inevitably lose flexibility and affect the service life of the metal structure.

Patent document CN201210186867.1 discloses a deep-sea environment steel structure spraying polyurethane anticorrosive primer. The primer is a polyurethane modified epoxy solventless primer. After being modified by polyurethane, the epoxy solventless primer has a higher Solvent-free epoxy coatings have higher compressive strength and higher bond strength with steel structures and sprayed polyurethane. After the polyurethane-modified epoxy solvent-free primer and spray polyurethane coating are matched, test the overall coating and the steel structure's pull-out strength ≥10MPa.

Patent document CN200510110358.0 discloses a flame-retardant polyurea anticorrosive coating for chemical steel structure, which adopts high-viscosity semi-prepolymer synthesized by MDI polyisocyanate and polyether polyol and high content MDI polyisocyanate, flame retardant It is composed of component A, and component B is composed of amino-terminated polyethers, polyamine chain extenders, additives, flame retardants, pigments, etc., which are sprayed on the surface of steel to form component B with excellent mechanical properties, flame retardancy and resistance Polyurea elastic coating with acid and alkali corrosion and long service life.

In summary, the anticorrosive polyurea coatings used in marine engineering in the prior art still have unsatisfactory adhesion to metal structures and anticorrosion effects. In order to overcome the shortcomings of the prior art, it is necessary to provide a polyurea coating that can be applied to marine engineering. The polyurea coating has strong resistance to seawater and salt spray, and due to its strong bonding force with metal structures, it has the ability to resist the force of waves. It is strong, and it is difficult for marine microorganisms to attach, reducing the corrosive effect of microbial secretions.

Summary of the invention

One object of the present invention is to provide a marine engineering anticorrosive polyurea coating and a preparation method thereof, and another object of the present invention is to provide an application and use method of a marine engineering anticorrosive polyurea coating.

Specifically, the present invention provides a polyurea coating that can be applied to marine engineering. The polyurea coating has strong resistance to seawater and salt spray, and because of its strong binding force to metal structures, the ability to resist the force of waves is strong, and the marine microorganisms It is more difficult to attach and reduces the corrosive effect of microbial secretions.

The purpose of the present invention is achieved through the following technical solutions:

In the first aspect, the present invention provides an anticorrosive polyurea coating for marine engineering, the polyurea coating includes component A and component B, wherein the raw materials for component A include: polyisocyanate, polycarbonate polyol, group B Sub-preparation raw materials include: amino-terminated polyether, amino chain extender, modified nano titanium dioxide, nano zinc oxide, hydroxylamino carboxylic acid compounds, antifouling agent, anti-rust pigment, anti-settling agent, the modified nano titanium dioxide The preparation raw materials include: nanometer titanium dioxide, surfactant, silane coupling agent, silver nitrate, copper sulfate.

Preferably, the A component of the polyurea coating includes the following raw materials by mass: 50-70 parts by mass of polyisocyanate and 30-50 parts by polycarbonate polyol, and the B component includes the following raw materials by mass: Amino polyether 20-40 parts, amino chain extender 25-40 parts, modified nano titanium dioxide 1-8 parts, nano zinc oxide 0.1-3 parts, hydroxylamino carboxylic acid compounds 1-5 parts, antifouling agent 5- 12 parts, 10-20 parts of anti-rust pigment, 0.1-1 part of anti-settling agent.

Preferably, the modified nano-titanium dioxide includes the following raw materials by mass: 30-50 parts of nano-titanium dioxide, 3-5 parts of surfactant, 1-4 parts of silane coupling agent, 0.2-1 parts of silver nitrate, sulfuric acid 0.1-1 parts of copper.

The particle size of the nano titanium dioxide is 60-80 nm, preferably 65-75 nm.

The surfactant is selected from one or a combination of two or more of triethanolamine, silicate, and alkylnaphthalene sulfonic acid; preferably, the surfactant is selected from triethanolamine.

The silane coupling agent is selected from: KH560 and KH570.

In the present invention, the polyisocyanate is selected from: polymethylene polyphenyl polyisocyanate, hexamethylene diisocyanate, phenylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, toluene One or a combination of two or more of diisocyanate and diphenylmethane diisocyanate. Preferably, the polyisocyanate is selected from diphenylmethane diisocyanate.

The polycarbonate polyol is selected from polycarbonate diols (PCDL) with a molecular weight of 1000-1200.

The amino-terminated polyether is a polyetheramine with a molecular weight of 2000-5000. In a preferred embodiment of the present invention, the amino-terminated polyether is Jaffamine D-2000 or Jaffamine T-5000.

The amino chain extender is selected from one or more of diethyltoluenediamine (DETDA), 4,4-bis-sec-butylaminodiphenylmethane, and dimethylthiotoluenediamine (DMTDA) combination. In a preferred embodiment of the present invention, the amino chain extender is DETDA and 4,4-bis-sec-butylaminodiphenylmethane.

The hydroxylamino carboxylic acid compound is selected from one or a combination of two or more of hydroxyethylethylenediaminetriacetic acid and dihydroxyethylglycine. Preferably, the hydroxylamino carboxylic acid compound is selected from: hydroxyethylethylenediaminetriacetic acid.

The antifouling agent of the present invention is selected from 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (Sea-Nine211).

The anti-rust pigment of the present invention is selected from composite zinc aluminum phosphate.

The anti-settling agent of the present invention is selected from fumed silica or organic bentonite.

In the second aspect, the present invention provides a preparation method of marine engineering anticorrosive polyurea coating, which includes the following steps:

Preparation of component A: (1) Dehydrate the polycarbonate polyol at 110-120°C and a vacuum of -0.08-0.1Mpa for 2-3 hours, and then lower it to room temperature for later use;

(2) Put the polyisocyanate into the reactor, heat up to 45-50°C, add polycarbonate polyol dropwise, heat up to 80-90°C after dropping, keep it warm for 2-2.5 hours, take a sample and measure the NCO content, when the NCO content When it is 15.5-20.0%, it is lowered to room temperature, filtered, and sealed with nitrogen for storage for later use;

Preparation of component B: (1) Disperse nano-titanium dioxide in 25-30% hydrogen peroxide solution, stir for 30-40 minutes, filter, wash with acetone, and dry; disperse the dried nano-titanium dioxide in In the water, add surfactant, adjust the pH to 3.0-5.0, add silane coupling agent, ultrasonically disperse uniformly, add silver nitrate solution and copper sulfate solution dropwise to a final concentration of 0.03-0.05mol/L, and heat up to Stir at 90-100°C for 10-25 minutes, lower to room temperature, centrifuge, and dry to obtain modified nano titanium dioxide;

(2) Put the amino-terminated polyether into the mixing tank, add the amino chain extender and stir for 0.5-1 hour, add the hydroxylamino carboxylic acid compound, antifouling agent, anti-rust pigment, anti-settling agent, and then add the modified nano Titanium dioxide and nano-zinc oxide are stirred at 400-500 rpm for 45-60 minutes, filtered, and packaged for later use.

The application method of the marine engineering anticorrosive polyurea coating of the present invention includes brushing, dipping, flow coating or spraying. Preferably, one layer or two or more layers are applied on the substrate, and the substrate is preferably metal.

In the third aspect, the present invention provides an application method of marine engineering anticorrosive polyurea coating, including the following steps:

(1) Remove the old paint film of the substrate and clean the substrate;

(2) Mix the A component and B component of the coating thoroughly in a ratio of 1:3-8;

(3) Optionally, spray after 1-10 minutes of curing.

Wherein, the substrate cleaning in step (1) includes degreasing, rust removal, polishing, phosphating treatment, and sandblasting treatment.

Preferably, in the step (2), the A component and the B component are combined and mixed under high pressure. Preferably, the A component and the B component are directly subjected to impact mixing in the high pressure spraying equipment. Specifically, the A component and the B component are heated in two separate chambers, pressurized separately, and impact or collide with each other at high speeds to achieve tight mixing between the two components, and then apply to the On the substrate.

In a preferred embodiment of the present invention, the marine engineering anticorrosive polyurea coating is sprayed by Graco polyurea spraying equipment HXP-3, and the heating temperature of component A is set at 63-65°C on the spraying equipment, and component B is heated The temperature is 60-63℃, and the pipe insulation is 60℃. When spraying, the dynamic pressure of component A and component B is 1900-2200PSI, and the static pressure is 2400-2500PSI.

In a fourth aspect, the present invention provides an application of marine engineering anticorrosive polyurea coatings in marine engineering steel equipment, steel structure supports, ship parts, inner warehouses, outer shells, and deck metal products.

In the present invention, polycarbonate diol (PCDL) is a polymer with multiple carbonate group repeating units on the main chain and hydroxyl terminated at the end. PCDL is a polyol with excellent performance and is mainly used to prepare polycarbonate Compared with traditional polyol polyurethane, polycarbonate polyurethane has good oil resistance, abrasion resistance, oxidation resistance and biocompatibility.

When the surface of the steel structure is pretreated, such as sanding and sandblasting, the highly clean metal surface is in a highly active state. The iron element on the surface will absorb water molecules from the air to form a highly polar hydrated iron compound. The polar groups in hydroxylamino carboxylic acid compounds, such as hydroxyl, amino, etc., because they contain active hydrogen atoms, can produce a hydrogen bond-like bonding force with the metal surface, increasing the adhesion of the coating to the metal surface. In addition, the carboxyl group on the structure of the hydroxylamino carboxylic acid compound and the lone pair of electrons on the nitrogen atom can form a coordination bond with the metal ion on the surface of the substrate to increase the bonding force between the coating and the metal surface.

Ordinary nano titanium dioxide used in coatings is easy to agglomerate and cannot be dispersed stably. At the same time, it is prone to "chalking". In order to increase the dispersibility of nano titanium dioxide and improve its sterilization ability, in the present invention, silver nitrate and copper sulfate are used to The surface modification of the titanium dioxide is carried out. After the modification, the surface of the nano titanium dioxide is loaded with silver nitrate and copper sulfate. Surfactant can increase the degree of wetting of nanometer titanium dioxide in aqueous solution, and silane coupling agent makes the silver nitrate and copper sulfate loaded on nanometer surface more uniform and stable. The obtained modified nano-titanium dioxide is added to the system, and works together with the nano-zinc oxide to improve the antibacterial performance of the coating.

Sea-Nine211 is complementary to modified nano-titanium dioxide and nano-zinc oxide. It is difficult for microorganisms to adhere to the coating, which realizes the self-cleaning ability of the coating and avoids corrosion of the coating by microorganisms and their metabolites.

The composite zinc aluminum phosphate is used as an anti-rust pigment. The phosphate generated by the dissociation of the phosphate can passivate the metal surface and cause anode polarization, while the zinc ion and aluminum ion react in the cathode to form insoluble substances and cause the cathode polarization, which greatly Improve the salt spray resistance and cathodic stripping resistance of the coating.

The beneficial effects of the present invention are: the anticorrosive polyurea coating has a strong bonding force with the surface of the steel component, so that the coating is not easy to fall off on the surface of the substrate, and has a strong resistance to the reciprocating force of waves in the marine environment. Strong antibacterial effect makes it difficult for marine microorganisms to attach and reduces the corrosive effect of microbial secretions.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

Example 1 Preparation of modified nano titanium dioxide

Disperse 50 parts of nano-titanium dioxide in 25% hydrogen peroxide solution, stir for 30 minutes, filter, wash with acetone, and dry; disperse the dried nano-titanium dioxide in water and add 5 parts of surfactant triethanolamine, Adjust the pH to 5.0, add 3 parts of silane coupling agent KH560, disperse uniformly by ultrasonic, add dropwise silver nitrate solution and copper sulfate solution to a final concentration of 0.05mol/L, after the addition, heat up to 90°C, stir for 25 minutes, reduce To room temperature, centrifuge and dry to obtain modified nano titanium dioxide.

Comparative Example 1 Preparation of modified nano titanium dioxide

Compared with Example 1, the modified nano titanium dioxide prepared in Comparative Example 1 has no silane coupling agent on the surface, and the preparation method is as follows:

Disperse 50 parts of nano-titanium dioxide in 25% hydrogen peroxide solution, stir for 30 minutes, filter, wash with acetone, and dry; disperse the dried nano-titanium dioxide in water and add 5 parts of surfactant triethanolamine, Adjust the pH to 5.0, disperse uniformly by ultrasonic, add dropwise silver nitrate solution and copper sulfate solution to a final concentration of 0.05 mol/L. After the dropwise addition, the temperature is raised to 90°C, stirred for 25 minutes, cooled to room temperature, centrifuged, and dried to get the change. Sexual nano titanium dioxide.

Example 2 Preparation of anticorrosive polyurea coating

S1: Dehydrate 34 parts of polycarbonate diol at 120°C and a vacuum of -0.08Mpa for 2 hours, and lower to room temperature for later use;

S2: Put 66 parts of diphenyltoluene diisocyanate into the reaction kettle, heat up to 45°C, slowly add polycarbonate diol, dropwise add polycarbonate diol, and heat up to 80°C after dropping, keep it warm for 2 hours, take a sample to measure the NCO content, as NCO When the content is 19.0%, it is lowered to room temperature, filtered, and sealed with nitrogen for storage for later use;

S3: Put 34 parts of amino-terminated polyether D2000 into the mixing tank, add 30 parts of diethyltoluene diamine, 10 parts of 4,4-bis-sec-butylaminodiphenylmethane, stir for 0.5 hours, add hydroxyethyl ethylene diamine 5 parts of amine triacetic acid, 8 parts of Sea-Nine211, 14.7 parts of composite zinc aluminum phosphate, 0.3 parts of fumed silica, and 3 parts of modified nano-titanium dioxide prepared in Example 1 and 1 part of nano-zinc oxide at 500 rpm Stir for 45 minutes, filter and pack for later use.

Example 3 Preparation of anticorrosive polyurea coating

S1: Dehydrate 50 parts of polycarbonate diol at 110°C and a vacuum of -0.08Mpa for 2 hours, and lower to room temperature for later use;

S2: Put 70 parts of diphenyltoluene diisocyanate into the reactor, heat up to 50°C, slowly add polycarbonate diol, dropwise add polycarbonate diol, and heat up to 80°C after dropping, keep it warm for 2 hours, take a sample to measure the NCO content, when NCO When the content is 20.0%, it is lowered to room temperature, filtered, and sealed with nitrogen for storage for later use;

S3: Put 40 parts of amino-terminated polyether T5000 into the mixing tank, add 30 parts of diethyltoluenediamine and 10 parts of 4,4-bis-sec-butylaminodiphenylmethane, stir for 0.5 hours, add dihydroxyethylglycine 5 parts, 10 parts of Sea-Nine211, 17 parts of composite zinc aluminum phosphate, 0.5 parts of fumed silica, and 4 parts of modified nano titanium dioxide prepared in Example 1 and 1 part of nano zinc oxide, and stirred at 500 rpm for 45 Minute, filter and pack for later use.

Comparative Example 1 Preparation of anticorrosive polyurea coating

Compared with Example 2, the raw materials for the preparation of the anticorrosive polyurea coating do not contain hydroxylaminocarboxylic acid compounds, antifouling agents, and modified nano titanium dioxide and nano zinc oxide. The specific preparation method is as follows:

S1: Same as Example 2;

S2: same as in embodiment 2;

S3: Put 34 parts of amino-terminated polyether D2000 into the mixing tank, add 30 parts of diethyltoluene diamine, 10 parts of 4,4-bis-sec-butylaminodiphenylmethane, stir for 0.5 hours, add 14.7 of composite zinc aluminum phosphate 0.3 parts of fumed silica, stirred at 500 rpm for 45 minutes, filtered, and packaged for later use.

Comparative Example 2 Preparation of anticorrosive polyurea coating

Compared with Example 2, the raw materials for preparing the anticorrosive polyurea coating do not contain hydroxylamino carboxylic acid compounds. The specific preparation method is as follows:

S1: Same as Example 2;

S2: same as in embodiment 2;

S3: Put 34 parts of amino-terminated polyether D2000 into the mixing tank, add 30 parts of diethyltoluene diamine, 10 parts of 4,4-bis-sec-butylaminodiphenylmethane, stir for 0.5 hours, add 8 parts of Sea-Nine211 , 14.7 parts of composite zinc aluminum phosphate, 0.3 parts of fumed silica, 3 parts of modified nano titanium dioxide and 1 part of nano zinc oxide prepared in Example 1, stirred at 500 rpm for 45 minutes, filtered, and packaged for later use.

Comparative Example 3 Preparation of anticorrosive polyurea coating

Compared with Example 2, the raw materials for preparing the anticorrosive polyurea coating do not contain modified nano-titanium dioxide and nano-zinc oxide. The specific preparation method is as follows:

S1: Same as Example 2;

S2: same as in embodiment 2;

S3: Put 34 parts of amino-terminated polyether D2000 into the mixing tank, add 30 parts of diethyltoluene diamine, 10 parts of 4,4-bis-sec-butylaminodiphenylmethane, stir for 0.5 hours, add hydroxyethyl ethylene diamine 5 parts of amine triacetic acid, 8 parts of Sea-Nine211, 14.7 parts of composite zinc aluminum phosphate, 0.3 parts of fumed silica, stirred at 500 rpm for 45 minutes, filtered, and packaged for later use.

Comparative Example 4 Preparation of anticorrosive polyurea coating

Compared with Example 2, the antifouling agent is not contained in the raw materials for preparing the anticorrosive polyurea coating, and the specific preparation method is as follows:

S1: Same as Example 2;

S2: same as in embodiment 2;

S3: Put 34 parts of amino-terminated polyether D2000 into the mixing tank, add 30 parts of diethyltoluene diamine, 10 parts of 4,4-bis-sec-butylaminodiphenylmethane, stir for 0.5 hours, add hydroxyethyl ethylene diamine 5 parts of amine triacetic acid, 14.7 parts of composite zinc aluminum phosphate, 0.3 parts of fumed silica, 3 parts of modified nano titanium dioxide and 1 part of nano zinc oxide prepared in Example 1, stirred at 500 rpm for 45 minutes, and filtered , Packing spare.

Comparative Example 5 Preparation of anticorrosive polyurea coating

Compared with Example 2, the raw materials for preparing the anticorrosive polyurea coating do not contain modified nano-titanium dioxide and nano-zinc oxide. The specific preparation method is as follows:

S1: Same as Example 2;

S2: same as in embodiment 2;

S3: Put 34 parts of amino-terminated polyether D2000 into the mixing tank, add 30 parts of diethyltoluene diamine, 10 parts of 4,4-bis-sec-butylaminodiphenylmethane, stir for 0.5 hours, add hydroxyethyl ethylene diamine 5 parts of amine triacetic acid, 8 parts of Sea-Nine211, 14.7 parts of composite zinc aluminum phosphate, 0.3 parts of fumed silica, stirred at 500 rpm for 45 minutes, filtered, and packaged for later use.

Comparative Example 6 Preparation of anticorrosive polyurea coating

Compared with Example 2, the modified nano-titanium dioxide in the preparation raw material of the anticorrosive polyurea coating does not contain a silane coupling agent, and the specific preparation method is as follows:

S1: Same as Example 2;

S2: same as in embodiment 2;

S3: In step S3, 3 parts of the modified nano titanium dioxide prepared in Comparative Example 1 are added, and the other steps are the same as in Example 2.

Comparative Example 7 Preparation of anticorrosive polyurea coating

Compared with Example 2, the nano-titanium dioxide in the raw material for preparing the anticorrosive polyurea coating is unmodified ordinary nano-titanium dioxide. The specific preparation method is as follows:

S1: Same as Example 2;

S2: same as in embodiment 2;

S3: Add 3 parts of ordinary nano titanium dioxide in step S3, and the other steps are the same as in Example 2.

Effect Example 1 Basic performance test of anticorrosive polyurea coating

Choose several steel plates of 100cm×100cm, polish and sandblast the steel plates, and spray the coatings prepared in Example 2 and Example 3 with Graco polyurea spraying equipment HXP-3 to keep the coating thickness relatively uniform. The coating can be cured quickly, and the performance is tested after 7 days of curing. The results are shown in the following table:

Table 1 Basic properties of anticorrosive polyurea coatings

To	Detection Indicator	Example 2	Example 3
Coating state	Smooth and uniform, no precipitation	Smooth and uniform, no precipitation	Smooth and uniform, no precipitation
Solid content (%)	GB/T9272-2007	99.5%	99.5%

Abrasion resistance (g)	GB/T1768-2006	13	12
60 degree gloss	GB/T1743-1979	80	75
Flexibility	GB/T1731-1993	Level 1	Level 1
Tensile strength (MPa)	GB/T16777-1997	23.0	23.9
Cathodic stripping resistance rate	GB/T7788	＜5mm	＜5mm
Salt spray resistance	GB/T1771-91	≥3000h	≥3000h
Artificially accelerated aging performance	GB/T1865-2009	qualified	qualified

Effect Example 2 Detect the influence of hydroxylamino carboxylic acid compounds on coating adhesion

The purpose of adding hydroxylamino carboxylic acid compounds to the raw materials of the present invention is to increase the adhesion of the coating to the metal surface due to the hydroxyl group and amino group in the structure can produce a hydrogen bond-like bonding force with the metal surface; the carboxyl group and the nitrogen atom The lone pair of electrons can form coordination bonds with metal ions on the surface of the substrate to increase the bonding force between the coating and the metal surface.

Test purpose: to detect whether hydroxylamino carboxylic acid compounds increase the bonding force between the coating and the metal surface.

Test method: comprehensively analyze the coating effect by detecting the impact strength, salt spray resistance, microbial adhesion rate, and pull-out strength between the coating and the substrate, and select several steel plates of 100cm×100cm, and polish the steel plates. Sandblasting, spraying with Graco polyurea spraying equipment HXP-3 to keep the coating thickness relatively uniform, the coating can be cured quickly, and the performance test is performed after 7 days of curing. The specific test operations are as follows:

Impact resistance: test standard GBT1732-1993, lift the hammer of the impactor to a height of 0.5m, fix the test steel plate, make the hammer of the impactor fall freely to impact the paint film, repeat the impact 3 times, the 3 impact positions cannot overlap, you can use a magnifying glass Observe the state of the steel plate;

Pull-out strength: test standard GB 5210-85, clean and degrease the test coating, mix the two-component epoxy adhesive in proportion, stick the test column to the part of the coating to be tested, and ensure that the test column and the coating Adhesive is attached to all parts of the contact surface of the layer. After curing for 24 hours, a pull test is performed with a tensile tester;

Salt spray resistance: testing standard GB/T1771-91, put the test steel plate in the testing environment for 3000 hours, and observe the coating changes;

Microbial adhesion rate: A plate-hanging test was carried out on the test steel plate in a certain sea area in Shandong to simulate the state of the ship hull in seawater, and the microorganism adhesion rate on the test steel plate was counted on the 30th day.

Test group: Example 2, Comparative Example 1, and the coating formed by spraying the paint prepared in Comparative Example 2.

The test results are shown in the following table:

Table 2 Coating and metal surface adhesion and anti-microbial corrosion detection

It can be seen from the comparison results in Table 2 that when the coating does not contain hydroxylaminocarboxylic acid compounds, it will directly affect the adhesion of the coating to the metal substrate. The result of the pull-out test drops from 15.24MPa to 10.13MPa. The compound has little effect on resisting the adhesion of microorganisms. The difference between the adhesion rate of microorganisms in Example 2 and Comparative Example 2 is not obvious; Comparative Example 1 is that the coating contains neither hydroxylamino carboxylic acid compounds nor antibacterial compounds. The modified nano-titanium dioxide and antifouling agent, so the coating has poor adhesion to the substrate, and the ability to resist microbial adhesion is the worst.

Effect Example 3 Detecting the effect of modified nano titanium dioxide on the antimicrobial adhesion of the coating

Ordinary nano-titanium dioxide is wetted with surfactant and added with silane coupling agent, silver nitrate and copper sulfate to prepare nano-titanium dioxide with silver nitrate and copper sulfate on the surface, which not only solves the problem of easy agglomeration and easy powdering of nano-titanium dioxide, but also strengthens The antibacterial and anti-microbial adhesion ability of nano titanium dioxide.

Test purpose: To detect whether the modified nano-titanium dioxide in the coating has the effect of increasing antibacterial and antimicrobial adhesion.

Test method: Comprehensive analysis of the coating effect by detecting the impact strength, salt spray resistance, microbial adhesion rate, and pull-out strength between the coating and the substrate of the coating coating, as described above.

Test group: Example 2, Comparative Example 1, and the coating formed by the coating prepared in Comparative Example 3 after spraying.

The test results are shown in the following table:

Table 3 Coating and metal surface adhesion and anti-microbial corrosion detection

It can be seen from the comparison results in Table 3 that when the coating does not contain modified nano-titanium dioxide, the microbial adhesion rate has the greatest impact, which increases from about 12.5% to about 22.5%. It can be seen that the modified nano-titanium dioxide can inhibit Microbial adhesion, this is because nano titanium dioxide has a deep antibacterial effect. After loading silver nitrate and copper sulfate on its surface, the antibacterial effect is stronger and inhibits the adhesion of microorganisms. From the results of impact resistance test, pull-out test and salt spray resistance test, it can be found that the modified nano-titanium dioxide has little effect on the bonding force between the coating and the base material.

Effect Example 4 The combined use of modified nano titanium dioxide and antifouling agent has stronger antimicrobial adhesion

Ordinary nano-titanium dioxide is wetted with surfactant and added with silane coupling agent, silver nitrate and copper sulfate to prepare nano-titanium dioxide with silver nitrate and copper sulfate on the surface, which not only solves the problem of easy agglomeration and easy powdering of nano-titanium dioxide, but also strengthens The antibacterial and anti-microbial adhesion ability of nano titanium dioxide.

Test purpose: to test whether the combined use of modified nano-titanium dioxide and antifouling agent has the effect of increasing antimicrobial adhesion.

Test method: Comprehensive analysis of the coating effect by detecting the impact strength, salt spray resistance, microbial adhesion rate, and pull-out strength between the coating and the substrate of the coating coating, as described above.

Test group: Example 2, Comparative Example 1, Comparative Example 4 and Comparative Example 5 prepared coatings formed after spraying.

The test results are shown in the following table:

Table 4 Coating and metal surface adhesion and anti-microbial corrosion detection

Comparative example 4 is with modified nano-titanium dioxide without antifouling agent, and comparative example 5 is with anti-fouling agent without modified nano-titanium dioxide. It can be seen from the comparison results of Table 4 that compared with Example 2, the impact strength, The difference in pull-out strength and salt spray resistance is not obvious. The most important thing is the adhesion rate of microorganisms. Compared with the data in Example 2, the adhesion rate is higher, which shows that the antibacterial ability and antifouling ability of the modified nano-titanium dioxide The cleaning ability of the agent complements each other, making it difficult for microorganisms to adhere to the coating, and achieving self-cleaning of the coating.

Effect Example 5 The influence of silane coupling agent on the stability of modified nanometer titanium dioxide

The purpose of modifying nano-titanium dioxide is to hope that silver nitrate and copper sulfate can be stably attached to the surface of nano-titanium dioxide particles. The effect of silane coupling agent not only makes nano-titanium dioxide better dispersibility, but also makes the surface of nano-titanium dioxide better than silver nitrate and copper sulfate. Stable grafting to prevent silver nitrate and copper sulfate from falling off during mixing. When silver nitrate and copper sulfate are stably attached to the surface of nanoparticles, their antibacterial and antimicrobial adhesion capabilities are stronger.

Test purpose: To test the effect of silane coupling agent on the stability of modified nano-TiO2.

Test method: The above effect test proves that the modified nano-titanium dioxide has little effect on the adhesion of the coating and the substrate. Therefore, in this test, only the microbial adhesion rate is tested, and the test steel plate is tested on the 5th, 10th, 30th and 60th days. Statistics on the rate of microbial attachment.

Test group: Example 2, Comparative Example 1, Comparative Example 6, and Comparative Example 7 prepared coatings formed after spraying.

The test results are shown in the following table:

Table 5 Coating and metal surface adhesion and anti-microbial corrosion detection

To	Example 2	Comparative Example 1	Comparative Example 6	Comparative Example 7
Day 5	3.4-3.8%	7.9-8.4%	3.6-4.0%	5.0-5.6%
Day 10	7.5-8.1%	14.7-15.0%	10.3-10.5	10.5-11.0%
30th day	12.5-13.0%	23.1-24.0%	16.8-17.5%	17.1-17.9%
Day 60	15.4-16.1%	30.3-32.1%	23.4-23.6%	23.5-24.0%

It can be seen from the comparison results in Table 5 that on the 5th day, there is almost no difference in the microbial adhesion rate between Example 2 and Comparative Example 6. At this time, the antimicrobial adhesion ability of the two coatings is the same. By the 10th day, the two groups The data difference increased, about 7.5% and 10.3%, respectively. Until the 60th day, the microbial adhesion rate of Example 2 was 15.4-16.1%, and that of Comparative Example 6 was 23.4-23.6%. The difference increased significantly. The reason for the analysis may be that there was no silane coupling agent in the preparation process of the modified nano titanium dioxide of Comparative Example 6, and the nanoparticles appeared agglomerated, and the loaded silver nitrate and copper sulfate were unstable. The silver nitrate and silver nitrate and The loss of copper sulfate with seawater weakens the overall antimicrobial adhesion of the coating. Comparative Example 7 is ordinary nano-titanium dioxide. On the 60th day, the microbial adhesion rate of Comparative Example 7 and Comparative Example 6 was equivalent, indicating that on the 60th day, the surface of the modified nano-titanium dioxide in Comparative Example 6 had no silver nitrate and The copper sulfate load is consistent with the above-mentioned reason analysis.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand: It is still possible to modify the technical solutions described in the foregoing embodiments, or equivalently replace some or all of the technical features; these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention range.

Claims (9)

1. A marine engineering anticorrosive polyurea coating. The polyurea coating includes component A and component B. The raw materials for component A include polyisocyanate and polycarbonate polyol, and the raw materials for component B include: terminal amino groups. Polyether, amino chain extender, modified nano-titanium dioxide, nano-zinc oxide, hydroxylamino carboxylic acid compounds, antifouling agent, anti-rust pigment, anti-settling agent, the raw materials for preparing the modified nano-titanium dioxide include: nano-titanium dioxide, Surfactant, silane coupling agent, silver nitrate, copper sulfate; it is characterized in that the marine engineering anticorrosive polyurea coating is prepared by the following method:

   The preparation of component A is as follows:

   (1) Dehydrate the polycarbonate polyol at 110-120°C and a vacuum of -0.08 to -0.1Mpa for 2-3 hours, and lower it to room temperature for later use;

   (2) Put the polyisocyanate into the reactor, heat up to 45-50°C, add polycarbonate polyol dropwise, heat up to 80-90°C after dropping, keep it warm for 2-2.5 hours, take a sample and measure the NCO content, when the NCO content When it is 15.5-20.0%, it is lowered to room temperature, filtered, and sealed with nitrogen for storage for later use;

   The preparation of component B is as follows:

   (1) Disperse nanometer titanium dioxide in 25-30% hydrogen peroxide solution, stir for 30-40 minutes, filter, wash with acetone, and dry; disperse the dried nanometer titanium dioxide in water and add surfactant , Adjust the pH to 3.0-5.0, add silane coupling agent, ultrasonically disperse uniformly, dropwise add silver nitrate solution and copper sulfate solution to a final concentration of 0.03-0.05mol/L, after the addition, heat up to 90-100℃, stir After 10-25 minutes, reduce to room temperature, centrifuge and dry to obtain modified nano titanium dioxide;

   (2) Put the amino-terminated polyether into the mixing tank, add the amino chain extender and stir for 0.5-1 hour, add the proportional amount of hydroxylamino carboxylic acid compound, antifouling agent, anti-rust pigment, anti-settling agent, and modification Nano-titanium dioxide and nano-zinc oxide are stirred at 400-500 rpm for 45-60 minutes, filtered and packaged.
2. The anticorrosive polyurea coating according to claim 1, wherein the modified nano-titanium dioxide comprises the following raw materials by mass: 30-50 parts of nano-titanium dioxide, 3-5 parts of surfactant, silane coupling agent 1-4 parts, 0.2-1 parts of silver nitrate, 0.1-1 parts of copper sulfate, and the particle size of nano titanium dioxide is 60-80nm.
3. The anticorrosive polyurea coating according to claim 2, wherein the surfactant is selected from one or a combination of two or more of triethanolamine, silicate, and alkylnaphthalenesulfonic acid; the silane The coupling agent is selected from: KH560 and KH570.
4. The anticorrosive polyurea coating according to claim 1, wherein the A component of the polyurea coating comprises the following raw materials in parts by mass: 50-70 parts of polyisocyanate, 30-50 parts of polycarbonate polyol, The B component includes the following raw materials in parts by mass: 20-40 parts of amino-terminated polyether, 25-40 parts of amino chain extender, 1-8 parts of modified nano titanium dioxide, 0.1-3 parts of nano zinc oxide, hydroxylamino carboxylate 1-5 parts of acid compound, 5-12 parts of antifouling agent, 10-20 parts of anti-rust pigment, 0.1-1 part of anti-settling agent.
5. The anticorrosive polyurea coating according to claim 4, wherein the polyisocyanate is selected from the group consisting of polymethylene polyphenyl polyisocyanate, hexamethylene diisocyanate, phenylene diisocyanate, and dicyclohexylmethane One or a combination of two or more of diisocyanate, isophorone diisocyanate, toluene diisocyanate, and diphenylmethane diisocyanate;

   The polycarbonate polyol is selected from: polycarbonate diols with a molecular weight of 1000-1200;

   The amino-terminated polyether is a polyetheramine with a molecular weight of 2000-5000;

   The amino chain extender is selected from one or a combination of two or more of diethyltoluenediamine, 4,4-bis-sec-butylaminodiphenylmethane, and dimethylthiotoluenediamine;

   The hydroxylamino carboxylic acid compound is selected from one or a combination of two of hydroxyethylethylenediaminetriacetic acid and dihydroxyethylglycine;

   The antifouling agent is selected from 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one;

   The anti-rust pigment is selected from composite zinc aluminum phosphate;

   The anti-settling agent is selected from fumed silica or organic bentonite.
6. An application method of marine engineering anticorrosive polyurea coating according to claim 1, comprising: brushing, dipping, flow coating or spraying. Preferably, one or more layers are applied on the substrate. Preferably it is metal.
7. The application method of the anticorrosive polyurea coating according to claim 6, comprising the following steps:

   (1) Remove the old paint film of the substrate and clean the substrate;

   (2) Mix the A component and B component of the coating thoroughly in a ratio of 1:3-8;

   (3) Optionally, spray after 1-10 minutes of curing.
8. The application method of the anticorrosive polyurea coating according to claim 7, wherein the cleaning of the substrate in the step (1) includes degreasing, rust removal, sanding, phosphating treatment, and sandblasting treatment; the step ( In 2), the A component and the B component are combined and mixed under high pressure.
9. An application of the marine engineering anticorrosive polyurea coating according to any one of claims 1 to 5 in the anticorrosion of marine engineering steel equipment, steel structure supports, ship parts, inner warehouses, outer shells, and deck metal products.