CN110028885B

CN110028885B - Solvent-free high-toughness heavy-duty anticorrosive paint and preparation method thereof

Info

Publication number: CN110028885B
Application number: CN201910356633.9A
Authority: CN
Inventors: 王道前; 肖国亮; 连联益
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-04-29
Filing date: 2019-04-29
Publication date: 2021-07-06
Anticipated expiration: 2039-04-29
Also published as: CN110028885A

Abstract

The invention discloses a solvent-free heavy-duty anticorrosive primer-topcoat integrated coating, which comprises a component A and a component B, wherein the coating is obtained by mixing the component A and the component B in proportion. Wherein, the component A consists of resin, pigment, filler and auxiliary agent, and comprises the following components: modified polyaspartic acid ester resin, titanium dioxide, polytetrafluoroethylene powder, nano-alumina, a water absorbent, a leveling agent, an organic silicon defoamer, an antioxidant, an ultraviolet absorbent, polyamide wax and an epoxy active diluent. Compared with the epoxy coating and the acrylic polyurethane coating sold in the market, the coating disclosed by the invention is low in organic volatile matter content, and belongs to an environment-friendly coating; the coating has moderate viscosity, high drying speed, good compatibility with other resins, good fusion with a substrate material, strong adhesive force, plump appearance of a coating film, corrosion resistance, aging resistance and good toughness.

Description

Solvent-free high-toughness heavy-duty anticorrosive paint and preparation method thereof

Technical Field

The invention belongs to the technical field of heavy-duty anticorrosive coatings, and particularly relates to a solvent-free heavy-duty anticorrosive coating based on modified polyaspartic acid ester and a preparation method thereof.

Background

With the rapid development of national economic construction and national economy, various steel structures, concrete structures, aluminum-plastic structures and the like are increasingly applied to bridges, buildings, ports, traffic and other industrial and civil engineering, but the characteristic of easy corrosion (corrosion) brings huge economic loss to equipment manufacturing industries and damages natural resources and environmental protection. One statistic shows that corrosion loss accounts for 3-5% of GDP, which exceeds the sum of losses due to disasters such as fire, flood, drought and typhoon, and in 2010, the corrosion loss in china is at least 1.2 trillion yuan, and 25-40% of the loss can be avoided if effective corrosion protection measures are taken. Therefore, the anticorrosion is very important, the coating plays a good role in protecting various engineering products and facilities in various anticorrosion technologies, and a series of anticorrosion coatings are developed at home and abroad successively.

Anticorrosive coatings are generally divided into conventional anticorrosive coatings and heavy anticorrosive coatings, and are an essential coating in paint coatings. The conventional anticorrosive paint plays a role in corrosion resistance on metals and the like under general conditions, and protects the service life of nonferrous metals; the heavy anti-corrosion coating is a kind of anti-corrosion coating which can be applied in a relatively harsh corrosion environment, such as steel materials of ships, bridges, wharfs and the like, and has a longer protection period than the conventional anti-corrosion coating.

At present, the common heavy-duty coating systems in China comprise epoxy resin coatings, polyurethane resin coatings, glass flake coatings and the like. The epoxy resin has good film-forming property and higher adhesive force, but the epoxy resin is not ageing-resistant, is easy to pulverize and has poor medium-energy for bearing strong corrosion at high temperature; the polyurethane resin coating has excellent adhesive force, good mechanical property and good chemical corrosion resistance, but has poor construction performance and storage stability, a paint film is easy to foam, and in addition, the raw material isocyanate used in the production process of the polyurethane coating has great toxicity to people; the glass flake coating theoretically has excellent chemical corrosion resistance, water vapor and corrosive ion resistance and temperature resistance, but the coating has high requirements on the thickness of the flakes, the arrangement mode of the flakes and the adhesive force between the flakes and film-forming substances.

Polyaspartate coatings are a new aliphatic, slow-reacting, high-performance coating that has emerged in the polyurea industry in recent years, known as third generation polyureas. Polyaspartic acid ester resin is aliphatic secondary amine, which is discovered by Zwiener et al as the earliest in 1990 to be used as a reactive solvent for solvent-borne polyurethane coatings and can be miscible with common hydroxyl-containing polyesters and polyacrylate copolymers, thereby reducing the VOC content of the coating system. The spray polyurea technology is a novel green spray technology without solvent and with high reactivity. The technology has the outstanding characteristics of environmental protection, no pollution and capability of realizing rapid curing. However, because the reaction speed is too high, special high-temperature high-pressure impact type mixed spraying equipment is required for construction; poor wettability to the substrate and poor adhesion; pockmarks, orange peels and the like are easily formed on the surface of the coating, and the apparent state is poor; the reaction has concentrated heat release and large shrinkage.

CN103820013A discloses a heavy-duty spray polyurea coating, wherein the component A is composed of isocyanate and polyhydric alcohol, and the component B is composed of liquid polysulfide rubber, amine chain extender, pigment filler and auxiliary agent. The preparation process of the coating is complex, and special spraying equipment is required for construction.

CN102993929A discloses an epoxy modified spray polyurea anticorrosive paint for steel structure surface, wherein the component A is a semi-prepolymer prepared by the reaction of polyisocyanate, polyether polyol, epoxy resin and a small amount of diluent, and the component B is composed of amino-terminated polyether, amine chain extender, filler and auxiliary agent. The coating is prepared by using epoxy resin modified polyurea and adopting special spraying equipment, and the hardness of a paint film is higher.

CN103113813A discloses a corrosion-resistant anti-aging polymer nano modified coating material for a hydraulic steel structure. After the base material is subjected to sand blasting treatment, 2 lines of primer containing polytetrafluoroethylene nano-powder are brushed, and then a nano modified polyurea coating containing polytetrafluoroethylene nano-powder is sprayed by using special equipment. The polyurea component A consists of diisocyanate and polyether triol, and the component B consists of amino-terminated polyether, aniline and polytetrafluoroethylene nano powder accounting for 1-3% of the mass of the coating. The modified coating has improved corrosion resistance, but the preparation process is complex and has high requirements on spraying equipment. The double-layer coating structure makes the spraying process complicated and the construction efficiency low.

The conventional polyaspartate resins such as Bayer NH1420 and NH1520 resins have short operable time and poor adhesion to a substrate when NH1420 reacts with HDI trimer. When NH1520 reacts with HDI trimer, the coating starts to become brittle below 10 ℃ although the working time is long, and the adhesion to the substrate is substantially lost. It is therefore necessary to modify it to improve performance.

At present, flexible curing agents are widely adopted in the market to modify polyaspartic ester resin, so that the polyaspartic ester resin has long operation time and good toughness. The solvent-free flexible curing agent has high viscosity and high normal construction difficulty, if diluents such as organic solvents are added, the viscosity can be reduced, but the content of VOC (volatile organic compounds) is increased due to the addition of the organic solvents, and compared with the traditional anticorrosive paint, the solvent-free flexible curing agent does not belong to the category of solvent-free paint any more. With the restrictions of environmental regulations of various countries on VOC and the emphasis on environmental protection, the substitution of solvent-free coatings for solvent coatings will gradually become an important development direction.

In view of the above, there is a need to develop a solvent-free heavy-duty anticorrosive coating with good toughness, high impact strength, high coating compactness, good corrosion resistance, stable quality, controllable cost, convenient construction and environmental friendliness.

Disclosure of Invention

Aiming at the defects in the prior art, the invention mainly aims to provide a solvent-free high-toughness heavy-duty anticorrosive coating based on modified polyaspartic acid ester and a preparation method thereof.

The invention also aims to provide the modified polyaspartic acid ester and a preparation method thereof.

The above object of the present invention is achieved by the following means.

In a first aspect, the invention provides a solvent-free high-toughness heavy-duty anticorrosive paint which is obtained by mixing a component A and a component B in proportion. Wherein, the component A consists of resin, pigment, filler and auxiliary agent, and comprises the following components: modified polyaspartic acid ester resin, titanium dioxide, polytetrafluoroethylene powder, nano-alumina, a water absorbent, a leveling agent, an organic silicon defoamer, an antioxidant, an ultraviolet absorbent, polyamide wax and an epoxy active diluent.

In the coating, the proportion of each component in the component A is as follows according to the parts by weight:

modified polyaspartic acid ester resin: 40-70 parts; titanium dioxide: 20-35 parts; polytetrafluoroethylene powder: 5-15 parts; nano alumina: 2-10 parts; water absorbent: 3-10 parts; leveling agent: 0.2-1 part; and (3) organic silicon defoaming agent: 0.2-2 parts; antioxidant: 0.5-1.5 parts; ultraviolet absorber: 1-3 parts; polyamide wax: 0.5-2 parts; epoxy reactive diluent: 1-5 parts.

Further preferably, the weight ratio of each component in the component A is as follows:

modified polyaspartic acid ester resin: 45-65 parts of a binder; titanium dioxide: 20-30 parts of a solvent; polytetrafluoroethylene powder: 5-10 parts; nano alumina: 2-8 parts; water absorbent: 5-10 parts; leveling agent: 0.2-0.5 part; and (3) organic silicon defoaming agent: 0.2-1 part; antioxidant: 0.5-1 part; ultraviolet absorber: 1-2 parts; polyamide wax: 0.5-1 part; epoxy reactive diluent: 1-3 parts.

Further, after the components in the component A are uniformly mixed and stirred, the mixture is ground by a sand mill until the particle size is not more than 25 microns, and preferably not more than 20 microns.

In the coating, the component B comprises polyisocyanate or prepolymer thereof and water absorbent. Specifically, the component B comprises 4, 4' -dicyclohexyl methane diisocyanate (HMDI), solvent-free HDI trimer and a water absorbent.

Further, the weight ratio of each component in the component B is as follows:

4, 4' -dicyclohexylmethane diisocyanate (HMDI): 75-95 parts; solvent-free HDI trimer: 5-25 parts; 1-5 parts of water absorbent.

Preferably, the weight ratio of each component in the component B is as follows: 4, 4' -dicyclohexylmethane diisocyanate (HMDI): 80-90 parts of a solvent; solvent-free HDI trimer: 10-20 parts; 1-3 parts of water absorbent.

In the invention, the modified polyaspartic acid ester resin is prepared by reacting one or more of dimethyl maleate, diethyl maleate, diisobutyl maleate and dibutyl maleate with 4, 4' -diaminodicyclohexylmethane to obtain an intermediate, and then adding a toughening agent and an optional auxiliary agent, wherein the toughening agent is selected from primary amino-terminated resin, and the auxiliary agent is selected from at least one of nano-alumina, sodium polystyrene sulfonate or polyepoxysuccinic acid.

Preferably, the modified polyaspartic acid ester resin is prepared by reacting diethyl maleate with 4, 4' -diaminodicyclohexylmethane to obtain an intermediate, and then adding primary amino-terminated resin and nano-alumina; the raw materials comprise, by weight, 50-70 parts of diethyl maleate, 20-40 parts of 4, 4' -diaminodicyclohexylmethane, 10-20 parts of primary amino-terminated resin toughening agent and 1-5 parts of auxiliary agent.

Specifically, the preparation process of the modified polyaspartic ester resin is as follows:

1) 20-40 parts of 4, 4' -diaminodicyclohexyl methane (the purity is more than or equal to 99%) are added into a reaction kettle with mechanical stirring, and nitrogen is filled to replace air. Then controlling the temperature below 40 ℃, and slowly dripping 50-70 parts of diethyl maleate by using a titration funnel. After the dropwise addition is finished, heating to 85-90 ℃ and reacting at constant temperature for 18-24h to obtain an intermediate product of the addition reaction, and controlling the temperature in the whole addition reaction process.

2) After the addition reaction is finished, 10-20 parts of primary amino-terminated resin and 1-5 parts of auxiliary agent are added, the constant temperature reaction is continued for 40-48h, and the temperature is kept in the whole reaction process. And after the reaction is finished, cooling to room temperature, and discharging to obtain the modified polyaspartic acid ester resin, wherein the viscosity is 140-180 mPa.s at room temperature.

The modified polyaspartic acid ester resin disclosed by the invention is low in viscosity, good in compatibility with other resins, corrosion-resistant, ageing-resistant and good in toughness. In addition, the compatibility of the paint and a substrate can be improved, and a good spraying effect can be realized on the premise of not needing a primer.

In addition, the modified polyaspartic acid ester has long reaction activation period with aliphatic isocyanate, and the film forming and drying speed is high, and the prepared coating has good toughness, high impact strength, high coating compactness and good corrosion resistance. The prepared paint has low VOC and is suitable for spraying and manual painting of a high-pressure airless sprayer.

In the present invention, the primary amino-terminated resin is selected from amino-terminated urea-formaldehyde resins or amino-terminated epoxy resins, which may be selected, for example, from amino-terminated glycidyl ether-based epoxy resins. The primary amino-terminated resin has the effects that the resin with the primary amino end-termination not only can increase the toughness of the resin, but also can improve the corrosion prevention effect of the coating on a substrate, particularly a metal material substrate, the primary amino-terminated resin can form a layer of compact metal oxide film with a metal interface to passivate the electrode potential of the metal, the metal oxide film interface generates an electric field, the direction of the electric field is opposite to the electron transfer direction, the transfer of electrons from the metal to an oxide is blocked, and the barrier of the electron transfer is equivalent to the barrier of the electron transfer, so that the corrosion rate of the metal substrate can be effectively slowed down.

In the invention, the auxiliary agent of sodium polystyrene sulfonate or polyepoxysuccinic acid can be matched with the addition intermediate and the flexibilizer resin to form a branched dendritic network structure with better toughness, and has a synergistic toughening effect. The auxiliaries such as sodium polystyrene sulfonate, polyepoxysuccinic acid, nano alumina particles and the like are used for adjusting the viscosity of the coating, can further increase the fusibility of the coating and a substrate, can realize the effect that the coating is not easy to fall off under the condition of not coating a primer, and realizes the integration of the bottom and the top.

In the present invention, the water absorbing agent may be selected from any suitable species, for example, from silicate-based water absorbing agents, such as one or a combination of two or more of sodium silicate, dicalcium silicate, and tricalcium silicate.

In the invention, the leveling agent can be selected from polyether modified polydimethylsiloxane, which can reduce the surface tension of the coating, avoid shrinkage cavity and improve the smoothness of the coating. Such as TECH-284, manufactured by Shanghai Taco polymers.

In the present invention, the defoaming agent may be selected from any suitable species, for example, from amino-modified polydimethylsiloxane. In a preferred embodiment of the invention, the defoamer is dego corporation TEGO N.

In the invention, the antioxidant can be selected from one or a combination of more than two of an antioxidant 1010, an antioxidant 1076, an antioxidant CA, an antioxidant 164, an antioxidant DNP, an antioxidant DLTP, an antioxidant TNP, an antioxidant TPP, an antioxidant MB and an antioxidant 264.

In the invention, the ultraviolet absorbent is one or a combination of more than two of phenyl ortho-hydroxybenzoate, 2- (2 '-hydroxy-5' -methylphenyl) benzotriazole, 2, 4-dihydroxy benzophenone, 2-hydroxy-4-methoxy benzophenone, 2-hydroxy-4-n-octoxy benzophenone and hexamethyl phosphoric triamide.

In the present invention, the epoxy reactive diluent is selected from: butyl glycidyl ether, alcohol glycidyl ether, butyl phenyl glycidyl ether, cardanol glycidyl ether, trimethylolpropane polyglycidyl ether, 1, 6-hexanediol diglycidyl ether, 1, 4-butanediol diglycidyl ether, and polypropylene glycol diglycidyl ether.

Optionally, the polyisocyanate in the component B may also be selected from one or more of hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and diphenylmethane diisocyanate.

Optionally, the polyisocyanate prepolymer in the component B may be a prepolymer synthesized from polytetrahydrofuran ether glycol and one or more of hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and diphenylmethane diisocyanate.

In a preferred embodiment of the present invention, the polyisocyanate and prepolymer of component B is selected from Hexamethylene Diisocyanate (HDI) trimer, 4' -dicyclohexyl diisocyanate (HMDI).

In another aspect, the present invention provides a preparation method of the solvent-free high-toughness heavy anti-corrosion coating, comprising:

s1: the component A is prepared by the following steps:

(1) preparing modified polyaspartic ester resin, weighing required amount of modified polyaspartic ester resin, titanium dioxide, polytetrafluoroethylene powder, nano aluminum oxide, water absorbent, leveling agent, organic silicon defoamer, antioxidant, ultraviolet absorbent, polyamide wax and epoxy active diluent in proportion, and mixing;

(2) adding the mixed materials into a high-shear mixer, controlling the temperature to be 20-45 ℃, the rotating speed to be 1000-3000rpm, and mixing for 10-20min to be uniform;

(3) transferring the mixture obtained in the previous step into a sand mill, and grinding until the fineness is less than or equal to 20 mu m.

S2: preparing a component B: the required amounts of 4, 4' -dicyclohexylmethane diisocyanate (HMDI), solvent-free HDI trimer and water-absorbing agent were mixed homogeneously.

Optionally, a mixing step in use is also included: mixing and stirring the component A and the component B uniformly according to the weight ratio of (2-10) to 1; preferably, the weight ratio (3-8) is 1.

Preferably, the preparation method of the modified polyaspartic acid ester resin described in step S1 includes:

1) 20-40 parts of 4, 4' -diaminodicyclohexylmethane is added into a reaction kettle with mechanical stirring, and nitrogen is filled to replace air. Then 50-70 parts of diethyl maleate are slowly dripped under the condition of controlling the temperature at 20-30 ℃. After the dropwise addition, the temperature is raised to 90 ℃ for constant-temperature reaction for 24 hours to obtain an intermediate product of the addition reaction, and the temperature is kept in the whole process of the addition reaction.

2) After the addition reaction is finished, 10-20 parts of primary amino-terminated resin and 0-5 parts of auxiliary agent are added, the constant temperature reaction is continued for 48 hours, and the temperature is kept in the whole reaction process. And after the reaction is finished, cooling to room temperature, and discharging to obtain the modified polyaspartic ester resin.

In a third aspect, the present invention provides a method for using the coating, comprising the steps of:

(1) before painting, removing an old paint film of the substrate, and cleaning the substrate;

(2) fully stirring and uniformly mixing the component A and the component B of the coating according to a proportion;

(3) optionally, the coating is carried out after standing and curing for 1-10 min.

Wherein, the substrate cleaning of step (1) still includes deoiling, rust cleaning, still needs bonderizing to the metal substrate.

Wherein, the mixing ratio of the component A and the component B in the step (2) is 3-8: 1.

Wherein the painting method in the step (3) comprises airless spraying, air spraying, brushing or rolling.

In a fourth aspect, the present invention provides the use of the coating for the preservation of corrosion resistant equipment selected from paper equipment, pharmaceutical equipment, food equipment, chemical equipment, cement manufacturing equipment or marine equipment.

In a fifth aspect, the present invention provides the modified polyaspartic ester resin.

In a sixth aspect, the present invention provides a method for preparing the modified polyaspartic acid ester, comprising:

1) 4, 4' -diaminodicyclohexyl methane is added into a reaction kettle with mechanical stirring, and nitrogen is filled to replace air. Then diethyl maleate is slowly dripped under the condition of controlling the temperature between 20 and 30 ℃. After the dropwise addition, the temperature is raised to 90 ℃ for constant-temperature reaction for 24 hours to obtain an intermediate product of the addition reaction, and the temperature is kept in the whole process of the addition reaction.

2) And after the addition reaction is finished, adding primary amino group end-capped resin and an auxiliary agent, continuing the constant-temperature reaction for 48 hours, and keeping the temperature control in the whole reaction process. And after the reaction is finished, cooling to room temperature, and discharging to obtain the modified polyaspartic ester resin.

The coating disclosed by the invention has the following advantages:

1) the modified polyaspartic acid ester resin disclosed by the invention is low in viscosity, good in compatibility with other resins and good in toughness. The paint can be sprayed without primer, has low VOC, and is suitable for spraying and manual painting of a high-pressure airless sprayer.

2) The modified polyaspartic acid ester has long reaction activation period with aliphatic isocyanate, and high film-forming and drying speed, and the prepared coating has good toughness, high impact strength, high coating compactness and good corrosion resistance.

3) Compared with the commercially available epoxy coating and acrylic polyurethane coating, the coating has high content of non-volatile matters and low content of volatile matters, and belongs to environment-friendly coating; the modified polyaspartic acid ester is added, so that the modified polyaspartic acid ester has good fusion with a substrate material, strong adhesive force, plump appearance of a coating film, corrosion resistance, aging resistance and good toughness.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only some embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1A

Preparation of modified polyaspartic acid ester

1) 35 parts of 4, 4' -diaminodicyclohexylmethane (purity is more than or equal to 99%) are added into a reaction kettle with mechanical stirring, and nitrogen is filled to replace air. Then, 50 parts of diethyl maleate was slowly added dropwise to the mixture at 30 ℃ using a titration funnel. After the dropwise addition, the temperature is raised to 90 ℃ for constant-temperature reaction for 24 hours to obtain an intermediate product of the addition reaction, and the temperature is kept in the whole process of the addition reaction.

2) After the addition reaction is finished, 20 parts of amino-terminated urea-formaldehyde resin, 3 parts of sodium polystyrene sulfonate and 2 parts of nano aluminum oxide are added, the constant temperature reaction is continued for 48 hours, and the temperature is controlled to be 90 ℃ in the whole reaction process. And after the reaction is finished, cooling to room temperature, discharging to obtain the modified polyaspartic acid ester resin with the viscosity of 158mPa.s at room temperature (25 ℃).

Example 1B

Preparation of modified polyaspartic acid ester

1) 40 parts of 4, 4' -diaminodicyclohexylmethane (purity is more than or equal to 99%) are added into a reaction kettle with mechanical stirring, and nitrogen is filled to replace air. Then, 50 parts of diethyl maleate was slowly added dropwise to the mixture at 30 ℃ using a titration funnel. After the dropwise addition, the temperature is raised to 90 ℃ for constant-temperature reaction for 24 hours to obtain an intermediate product of the addition reaction, and the temperature is kept in the whole process of the addition reaction.

2) After the addition reaction is finished, adding 20 parts of amino-terminated urea-formaldehyde resin, 3 parts of sodium polystyrene sulfonate and 2 parts of polyepoxysuccinic acid, continuing to perform constant-temperature reaction for 48 hours, and controlling the temperature to be 90 ℃ in the whole reaction process. And after the reaction is finished, cooling to room temperature, discharging to obtain the modified polyaspartic acid ester resin with the viscosity of 167mPa.s at room temperature (25 ℃).

Example 1C

Preparation of modified polyaspartic acid ester

1) 36 parts of 4, 4' -diaminodicyclohexylmethane (purity is more than or equal to 99%) are added into a reaction kettle with mechanical stirring, and nitrogen is filled to replace air. Then, 50 parts of diethyl maleate was slowly added dropwise to the mixture at 30 ℃ using a titration funnel. After the dropwise addition, the temperature is raised to 90 ℃ for constant-temperature reaction for 24 hours to obtain an intermediate product of the addition reaction, and the temperature is kept in the whole process of the addition reaction.

2) After the addition reaction is finished, 20 parts of amino-terminated urea-formaldehyde resin is added, the constant temperature reaction is continued for 48 hours, and the temperature is controlled at 90 ℃ in the whole reaction process. And after the reaction is finished, cooling to room temperature, discharging to obtain the modified polyaspartic acid ester resin with the viscosity of 157mPa.s at room temperature (25 ℃).

Comparative example 1A

Preparation of modified polyaspartic acid ester

2) After the addition reaction is finished, 20 parts of bisphenol A epoxy resin, 3 parts of sodium polystyrene sulfonate and 2 parts of nano aluminum oxide are added, the constant temperature reaction is continued for 48 hours, and the temperature is controlled at 90 ℃ in the whole reaction process. And after the reaction is finished, cooling to room temperature, and discharging to obtain the modified polyaspartic acid ester resin with the viscosity of 238mPa.s at room temperature.

Comparative example 1B

Preparation of modified polyaspartic acid ester

2) After the addition reaction is finished, 20 parts of bisphenol F epoxy resin is added, the constant temperature reaction is continued for 48 hours, and the temperature is controlled at 90 ℃ in the whole reaction process. And after the reaction is finished, cooling to room temperature, and discharging to obtain the modified polyaspartic acid ester resin with the viscosity of 245mPa.s at room temperature.

Comparative example 1C

Preparation of modified polyaspartic acid ester

2) After the addition reaction is finished, 2 parts of nano aluminum oxide is added, the constant temperature reaction is continued for 2 hours, and the temperature is controlled at 90 ℃ in the whole reaction process. And after the reaction is finished, cooling to room temperature, and discharging to obtain the modified polyaspartic ester resin.

Example 2

Preparation of solvent-free heavy-duty anticorrosive paint 1

S1: preparation of the component A:

(1) weighing modified polyaspartic acid ester resin, titanium dioxide, polytetrafluoroethylene powder, nano-alumina, a water absorbent, a leveling agent, an organic silicon defoamer, an antioxidant, an ultraviolet absorbent, polyamide wax and an epoxy active diluent according to a proportion, wherein the proportion of each component is as follows in parts by weight: 60 parts of modified polyaspartic ester resin prepared in example 1A; 25 parts of titanium dioxide; 5 parts of polytetrafluoroethylene powder; 5 parts of nano aluminum oxide; 5 parts of sodium silicate water absorbent; 0.5 part of TECH-284 flatting agent; 0.5 part of organic silicon defoamer TEGO N; 1010 antioxidant: 0.5 part; 1.5 parts of ultraviolet absorbent phenyl ortho-hydroxybenzoate; 1 part of polyamide wax; 3 parts of butyl glycidyl ether.

(2) Mixing the mixed materials in a high-shear mixer at the temperature of 38 ℃ and the rotating speed of 2000rpm for 10min until the mixed materials are uniform; transferring the mixture into a sand mill, and grinding the mixture until the fineness is less than or equal to 20 mu m.

S2: preparing a component B: weighing the following materials in parts by weight: 80 parts of 4, 4' -dicyclohexyl methane diisocyanate (HMDI), 18 parts of solvent-free HDI trimer and 2 parts of sodium silicate water absorbent, and the components are uniformly mixed to obtain a component B.

Example 3

Preparation of solvent-free heavy-duty anticorrosive paint 2

S1: preparation of the component A:

(1) weighing modified polyaspartic acid ester resin, titanium dioxide, polytetrafluoroethylene powder, nano-alumina, a water absorbent, a leveling agent, an organic silicon defoamer, an antioxidant, an ultraviolet absorbent, polyamide wax and an epoxy active diluent according to a proportion, wherein the proportion of each component is as follows in parts by weight: 65 parts of the modified polyaspartic acid ester resin prepared in example 1B; 30 parts of titanium dioxide; 5 parts of polytetrafluoroethylene powder; 5 parts of nano aluminum oxide; 5 parts of calcium silicate water absorbent; 0.5 part of TECH-284 flatting agent; 0.5 part of organic silicon defoamer TEGO N; 1076 antioxidant: 0.5 part; 1.5 parts of ultraviolet absorbent phenyl ortho-hydroxybenzoate; 1 part of polyamide wax; 3 parts of butyl glycidyl ether.

(2) Mixing the mixed materials in a high-shear mixer at the temperature of 40 ℃ and the rotation speed of 1500rpm for 15min to be uniform; transferring the mixture into a sand mill, and grinding the mixture until the fineness is less than or equal to 20 mu m.

S2: preparing a component B: weighing the following materials in parts by weight: 80 parts of 4, 4' -dicyclohexyl methane diisocyanate (HMDI), 15 parts of solvent-free HDI tripolymer and 5 parts of calcium silicate water absorbent, and the components are uniformly mixed to obtain a component B.

Comparative example 2

The components and preparation conditions were the same as in example 2 except that the modified polyaspartic ester resin in component A was replaced with the polyaspartic ester resin prepared in comparative example 1C.

The preparation of the component B is the same as that of the example 2; the resulting coating was prepared and designated D2.

Comparative example 3

The components and preparation conditions were the same as in example 2 except that the modified polyaspartic ester resin in component A was replaced with the polyaspartic ester resin prepared in comparative example 1A.

The preparation of the component B is the same as that of the example 2; the resulting coating was prepared and designated D3. The preparation of component B was the same as in example 2.

Effect example 1

The test method comprises the following steps: the coating prepared in example 2 was prepared as follows: uniformly mixing the component B in a weight ratio of 6:1, stirring until the spraying viscosity is 30-40S (T-4 cup), taking a salt spray resistance test steel plate, a high temperature resistance test 3-5mm thick steel plate and a standard tinplate, performing oil removal, rust removal and polishing treatment, performing phosphating treatment, scrubbing the surface with 120# solvent oil, and then filtering and spraying with a 200-mesh filter screen. The thickness of a paint film of the chemical resistance performance, weather resistance performance and salt spray resistance test board is controlled to be about 90-100 mu m, and the thickness of a conventional performance test board is controlled to be 20-30 mu m. And after the paint is completely dried for 48 hours, carrying out comprehensive performance test, and testing the chemical resistance, salt spray resistance and artificial aging resistance of the paint according to the detection standard. The comparative coatings were commercially available epoxy coatings and acrylic polyurethane coatings, and the comparative results are shown in the following table:

TABLE 1 comparison of heavy duty anticorrosive coatings with commercially available conventional coatings

As can be seen from the comparative data, the solvent-free heavy-duty anticorrosive coating prepared by the invention has the highest content of non-volatile substances and less content of volatile substances, and belongs to an environment-friendly coating; the drying time is short, and the construction is convenient; the impact resistance and the wear resistance are good; compared with the commercial epoxy coating and acrylic polyurethane coating, the epoxy coating and acrylic polyurethane coating have stronger acid and alkali resistance, salt fog resistance and aging resistance.

Effect example 2

Test groups:

dope 1 prepared in example 2, dope D2 and D3 prepared in comparative example.

The test method comprises the following steps: as described in effect example 1.

The comparative results are shown in the following table.

TABLE 2 Performance test results for heavy duty primer-topcoat in one coating

According to the results, the coating 1 of the invention has the advantages of short drying time, fast construction, stronger adhesion to the base material, best impact resistance and toughness, and stronger acid and alkali resistance, salt mist resistance and aging resistance. The modified polyaspartic acid ester prepared by the invention is proved to have excellent modification effect after being added with a certain amount of primary amino-terminated resin toughening agent and auxiliary agent. One reason for this is that the primary amino-terminated resin not only increases the toughness of the resin, but also improves the corrosion protection of the coating on substrates, especially metal substrates, and the primary amino-terminated resin can form a dense metal oxide film with the metal interface to prevent or slow down the corrosion rate. The auxiliary agent can increase the fusion of the coating and the substrate.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same. Those of ordinary skill in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A solvent-free high-toughness heavy-duty anticorrosive paint is obtained by mixing a component A and a component B in proportion; the adhesive is characterized in that the component A comprises the following components in parts by weight: 45-65 parts of modified polyaspartic acid ester resin, 20-30 parts of titanium dioxide, 5-10 parts of polytetrafluoroethylene powder, 2-8 parts of nano aluminum oxide, 5-10 parts of water absorbent, 0.2-0.5 part of flatting agent, 0.2-1 part of organic silicon defoamer, 0.5-1 part of antioxidant, 1-2 parts of ultraviolet absorbent, 0.5-1 part of polyamide wax and 1-3 parts of epoxy active diluent;

the modified polyaspartic acid ester resin is obtained by the following reaction preparation process:

(1) adding 35 parts by weight of 4, 4' -diaminodicyclohexylmethane into a reaction kettle with a mechanical stirrer, introducing nitrogen to replace air, controlling the temperature at 30 ℃, slowly dropwise adding 50 parts by weight of diethyl maleate into a titration funnel, heating to 90 ℃ after dropwise adding, reacting at constant temperature for 24 hours to obtain an intermediate product of addition reaction, and keeping the temperature control in the whole addition reaction process;

(2) after the addition reaction is finished, adding 20 parts of amino-terminated urea-formaldehyde resin, 3 parts of sodium polystyrene sulfonate and 2 parts of nano aluminum oxide, continuing to perform constant-temperature reaction for 48 hours, keeping temperature control in the whole reaction process, cooling to room temperature after the reaction is finished, and discharging to obtain modified polyaspartic acid ester resin;

the component B comprises the following components in parts by weight: 75-95 parts of 4, 4' -dicyclohexylmethane diisocyanate, 5-25 parts of solvent-free HDI trimer and 1-5 parts of water absorbent.

2. The coating of claim 1, wherein the water-absorbing agent is selected from silicate-based water-absorbing agents; the leveling agent is selected from polyether modified polydimethylsiloxane; the defoaming agent is selected from amino modified polydimethylsiloxane; the ultraviolet absorbent is one or the combination of more than two of phenyl ortho-hydroxybenzoate, 2- (2 '-hydroxy-5' -methylphenyl) benzotriazole, 2, 4-dihydroxy benzophenone, 2-hydroxy-4-methoxy benzophenone, 2-hydroxy-4-n-octoxy benzophenone and hexamethyl phosphoric triamide.

3. The coating of claim 1, wherein the epoxy reactive diluent is selected from the group consisting of butyl glycidyl ether, butyl phenyl glycidyl ether, cardanol glycidyl ether, trimethylolpropane polyglycidyl ether, 1, 6-hexanediol diglycidyl ether, 1, 4-butanediol diglycidyl ether, and polypropylene glycol diglycidyl ether, and a combination of two or more thereof.

4. A method for preparing a coating according to any one of claims 1 to 3, comprising the steps of:

s1: preparing a component A:

(1) preparing modified polyaspartic acid ester resin; weighing modified polyaspartic acid ester resin, titanium dioxide, polytetrafluoroethylene powder, nano-alumina, a water absorbent, a leveling agent, an organic silicon defoamer, an antioxidant, an ultraviolet absorbent, polyamide wax and an epoxy active diluent according to a proportion;

(3) transferring the mixture obtained in the previous step into a sand mill, and grinding until the fineness is less than or equal to 20 mu m;

s2: preparing a component B: the required amounts of 4, 4' -dicyclohexylmethane diisocyanate, solvent-free HDI trimer and water-absorbing agent were mixed homogeneously.

5. Use of a coating according to any one of claims 1 to 3 for the corrosion protection of equipment.