WO2021212406A1

WO2021212406A1 - Haa low temperature curing super-leveling weatherable powder coating

Info

Publication number: WO2021212406A1
Application number: PCT/CN2020/086391
Authority: WO
Inventors: 孙华强; 杨立新
Original assignee: 浙江华彩新材料有限公司
Priority date: 2020-04-23
Filing date: 2020-04-23
Publication date: 2021-10-28

Abstract

An HAA low temperature curing super-leveling weatherable powder coating composed of the following components in percentage by weight: 60-70% of modified carboxyl polyester resin, 5.8-6.5% of HAA curing agent, 1.8-3.0% of leveling agent, 0.2%-0.5% of weatherability additive, 0.2-0.5% of dispersing additive, 0.3%-0.8% of benzoin and the remainder being pigments and fillers. The leveling agent is a nitrogen-doped graphene/molybdenum disulfide composite material and the weatherability additive is a silicon-modified bagasse molecular sieve.

Description

A kind of HAA low-temperature curing super-leveling weather-resistant powder coating

Technical field

The invention relates to the technical field, in particular to a HAA low-temperature curing super-leveling weather-resistant powder coating.

Background technique

Powder coating is a 100% solid powder that does not contain organic solvents. It is different from oil-based coatings and water-based coatings. It does not use solvent or water as the dispersion medium when painting, but uses air as the dispersion medium to uniformly coat the workpiece. The surface is heated to form a new type of environmentally friendly paint with a special-purpose coating film. Powder coating has the characteristics of no VOC, environmental protection, energy saving, high construction efficiency and wide application range.

However, traditional powder coatings have the characteristics of poor surface leveling performance, while imported leveling agents cost very high; but in recent years, it has been found that HAA curing agents can cause mutations and heredity to human germ cells. Most countries in the European Union have The use of TGIC is prohibited. Therefore, the development and use of environmentally friendly HAA systems is a general trend. Due to environmental pollution, ordinary weather-resistant coatings can no longer meet the erosion of outdoor acid rain, high temperature, and dust. Therefore, it is necessary to study a HAA low-temperature curing super-level weathering resistance Powder coating.

Summary of the invention

Based on the technical problems existing in the background art, the present invention proposes a HAA low-temperature curing super-leveling weather-resistant powder coating.

The technical scheme of the present invention is as follows:

A HAA low-temperature curing super-leveling weather-resistant powder coating, which is composed of the following components by weight percentage: carboxyl polyester resin 60-70%, HAA curing agent 5.8-6.5%, leveling agent 1.8-3.0%, and weathering aid 0.2- 0.5%, dispersing aid 0.2-0.5%, benzoin 0.3-0.8% and the balance of pigments and fillers.

Preferably, the glass transition temperature of the carboxyl polyester resin is 57-62°C, the softening point is 105-120°C, and the viscosity is 18.0-32.0Pa. s (200°C), the acid value is 40-55 mg KOH/g; the HAA curing agent is β-hydroxyalkyl amide, and its equivalent is 82-90 g/eq.

Preferably, the weathering aid is silicon modified bagasse molecular sieve.

The preparation method of the silicon modified bagasse molecular sieve includes the following steps:

Step 1: After a simple cleaning of the bagasse, mechanically crush it to 1-3mm, heat it to 190-260℃ with steam for 2-5min, and then release the pressure within 0.1-1s to make the bagasse cell wall The fiber is puffed to obtain puffed bagasse for use;

Step 2: Soak the puffed bagasse in 10-15 times the volume of enzyme solution and hydrolyze it at pH 4-5 and 60-65°C for 15-25 minutes;

Step 3: Treat the solution under ultrasonic waves with a frequency of 25-35KHz for 30-40 minutes, filter, and collect the filtrate;

Step 4: Add ethanol to make the concentration in the filtrate 80-90%, precipitate the bagasse polysaccharide solid, and vacuum dry to obtain the bagasse polysaccharide solid;

Step 5: Put the bagasse polysaccharide solid into the carbonization furnace, lay the raw materials naturally on the plane, raise the temperature to the carbonization temperature, and carbonize to obtain carbon molecular sieve;

Step 6: Put the carbon molecular sieve into the silicon source and mix evenly, and soak for 3-5h at 60-80℃;

Step 7: Drain the soaked carbon molecular sieve; then roast at 600-800° C., pulverize repeatedly, and pass through a 325-mesh sieve to obtain silicon-modified bagasse molecular sieve.

Further preferably, the silicon source is any one of ethyl orthosilicate, propyl orthosilicate or butyl orthosilicate.

Further preferably, in the sixth step, the mass ratio of the carbon molecular sieve to the silicon source is 1: (3-5).

Preferably, the dispersing aid is Corning wetting agent 875.

Preferably, the pigment filler is one or a mixture of anatase titanium dioxide, barium sulfate, wollastonite, and mica powder.

Preferably, the leveling agent is a nitrogen-doped graphene/molybdenum disulfide composite material.

Further preferably, the method for preparing the nitrogen-doped graphene/molybdenum disulfide composite material includes the following steps:

Disperse 10-20 mg of graphene oxide in 200 mL of ethanol solution, perform ultrasonic dispersion, then stir and heat the mixture in an oil bath at 85-90°C, and then add 250-300 mg of sodium molybdate and 1.2-1.5 to the mixture g sodium sulfide, and adjust the pH value of the whole system to 3 with hydrochloric acid solution, remove the impurity ions and solvents to obtain a brown precipitate, collect the brown precipitate and dry it to obtain a precursor material; place the precursor material in a quartz boat , And placed in a tube furnace filled with nitrogen, heated at 550°C for 3-3.5 hours to obtain a nitrogen-doped graphene/molybdenum disulfide composite material.

The advantages of the present invention are: the HAA low-temperature curing super-leveling weather-resistant powder coating of the present invention is composed of the following components by weight percentage: carboxyl polyester resin 60-70%, HAA curing agent 5.8-6.5%, leveling agent 1.8 -3.0%, weathering aid 0.2-0.5%, dispersing aid 0.2-0.5%, benzoin 0.3-0.8% and the balance of pigments and fillers. Among them, the leveling agent is a nitrogen-doped graphene/molybdenum disulfide composite material. The composite material is compounded with a crystallized molybdenum disulfide layer on the surface of the graphene while being doped with nitrogen. The molybdenum disulfide layer is combined with graphite oxide. The combination of the flat layer structure of the ene makes the coating have a very good leveling effect; and the silicon-modified bagasse molecular sieve is used as the weathering aid. The silicon modified bagasse molecular sieve carbonizes the bagasse to obtain the carbon molecular sieve. Soaking in medium and then roasting at high temperature, the silicon is doped into the molecular sieve, so that the combination effect of the molecular sieve and other components in the coating is significantly improved. At the same time, the doping of silicon into the molecular sieve also significantly improves the anti-ultraviolet performance and acid resistance of the original molecular sieve. . The HAA low-temperature curing powder coating of the present invention has very good leveling performance and weather resistance.

Detailed ways

Example 1

A HAA low-temperature curing super-leveling weather-resistant powder coating, which is composed of the following components by weight percentage: carboxyl polyester resin 65%, HAA curing agent 6.2%, nitrogen-doped graphene/molybdenum disulfide composite material 2.2%, silicon modified Bagasse molecular sieve 0.3%, Corning wetting agent 8750.3%, benzoin 0.5% and the balance of pigments and fillers.

The glass transition temperature of the carboxyl polyester resin is 57-62°C, the softening point is 105-120°C, and the viscosity is 18.0-32.0Pa. s (200°C), the acid value is 40-55 mg KOH/g; the HAA curing agent is β-hydroxyalkyl amide, and its equivalent is 82-90 g/eq.

The preparation method of the nitrogen-doped graphene/molybdenum disulfide composite material includes the following steps:

Disperse 18 mg of graphene oxide in 200 mL of ethanol solution (20% by volume of ethanol) for ultrasonic dispersion, then stir and heat the mixture in an oil bath at 88°C, and then add 285 mg of sodium molybdate and 1.35g sodium sulfide, adjust the pH value of the whole system to 3 with hydrochloric acid solution, remove the impurity ions and solvents to obtain a brown precipitate, collect the brown precipitate and dry it to obtain a precursor material; place the precursor material in a quartz boat It is placed in a tube furnace filled with nitrogen and heated at 550°C for 3.2 hours to obtain a nitrogen-doped graphene/molybdenum disulfide composite material.

Step 1: After a simple cleaning of the bagasse, mechanically crush it to 1-3mm, heat it to 250°C with steam for 2.5min, and then release the pressure momentarily within 0.5s to puff the bagasse cell wall fibers to obtain Puffed bagasse is ready for use;

Step 2: Soak the puffed bagasse in a 12-fold volume of cellulase solution and hydrolyze it at pH 4.5 and 65°C for 20 minutes;

Step 3: Treat the solution under ultrasonic waves with a frequency of 30KHz for 35 minutes, filter, and collect the filtrate;

Step 4: Add ethanol to make the concentration in the filtrate reach 85%, precipitate the bagasse polysaccharide solid, and vacuum dry to obtain the bagasse polysaccharide solid;

Step 6: Put the carbon molecular sieve into the silicon source and mix uniformly, and soak for 3.5 hours at 75°C; the mass ratio of the carbon molecular sieve to the silicon source is 1:4;

The silicon source is ethyl orthosilicate;

Step 7: Drain the soaked carbon molecular sieve; then roast at a high temperature of 720°C for 1.5 hours, repeatedly pulverize, and pass through a 325-mesh sieve to obtain silicon-modified bagasse molecular sieve.

The pigment and filler are anatase titanium dioxide.

Example 2

A HAA low-temperature curing super-leveling weather-resistant powder coating, which is composed of the following components by weight percentage: carboxyl polyester resin 70%, HAA curing agent 5.8%, nitrogen-doped graphene/molybdenum disulfide composite material 3.0%, silicon modified 0.2% bagasse molecular sieve, Corning wetting agent 8750.5%, benzoin 0.3% and the balance of pigments and fillers.

Disperse 20 mg of graphene oxide in 200 mL of ethanol solution (the volume fraction of ethanol is 25%) for ultrasonic dispersion, then stir and heat the mixture in an oil bath at 85°C, and then add 300 mg of sodium molybdate and 1.2g sodium sulfide, adjust the pH value of the whole system to 3.5 with hydrochloric acid solution, remove the impurity ions and solvents to obtain a brown precipitate, collect the brown precipitate and dry it to obtain a precursor material; place the precursor material in a quartz boat It is placed in a tube furnace filled with nitrogen and heated at 550°C for 3.5 hours to obtain a nitrogen-doped graphene/molybdenum disulfide composite material.

Step 1: After a simple cleaning of the bagasse, mechanically crush it to 1-3mm, heat it to 190°C by steam, maintain it for 5min, and then release the pressure within 0.1s to make the bagasse cell wall fiber puffed and puffed Bagasse for spare use;

Step 2: Soak the puffed bagasse in 15 times the volume of cellulase solution and hydrolyze it at pH 5 and 60°C for 25 min;

Step 3: Treat the solution under ultrasonic waves with a frequency of 25KHz for 40 minutes, filter, and collect the filtrate;

Step 4: Add ethanol to make the concentration in the filtrate 80%, precipitate the bagasse polysaccharide solid, and vacuum dry to obtain the bagasse polysaccharide solid;

Step 6: Put the carbon molecular sieve into the silicon source and mix uniformly, and soak at 80°C for 3 hours; the mass ratio of the carbon molecular sieve to the silicon source is 1:5;

The silicon source is propyl orthosilicate;

Step 7: Drain the soaked carbon molecular sieve; then roast at 600°C for 2.5 hours, repeatedly pulverize, and pass through a 325-mesh sieve to obtain silicon-modified bagasse molecular sieve.

The pigment filler is a mixture of barium sulfate and mica powder in a mass ratio of 1:3.

Example 3

A HAA low-temperature curing super-leveling weather-resistant powder coating, which is composed of the following components by weight percentage: 60% carboxyl polyester resin, 6.5% HAA curing agent, 1.8% nitrogen-doped graphene/molybdenum disulfide composite material, silicon modified Bagasse molecular sieve 0.5%, Corning wetting agent 8750.2%, benzoin 0.8% and the balance of pigments and fillers.

Disperse 10 mg of graphene oxide in 200 mL of ethanol solution (the volume fraction of ethanol is 28%) for ultrasonic dispersion, then stir and heat the mixture in an oil bath at 90°C, and then add 250 mg of sodium molybdate and 1.5g sodium sulfide, adjust the pH value of the entire system to 3.2 with hydrochloric acid solution, remove the impurity ions and solvents to obtain a brown precipitate, collect the brown precipitate and dry it to obtain a precursor material; place the precursor material in a quartz boat It is placed in a tube furnace filled with nitrogen and heated at 550°C for 3 hours to obtain a nitrogen-doped graphene/molybdenum disulfide composite material.

Step 1: After a simple cleaning of the bagasse, mechanically crush it to 1-3mm, heat it to 260°C with steam for 2 minutes, and then release the pressure within 1 second to expand the bagasse cell wall fibers to obtain puffed sugarcane Slag spare

Step 2: Soak the puffed bagasse in 10 times the volume of cellulase solution and hydrolyze it at pH 4 and 62°C for 15 minutes;

Step 3: Treat the solution for 30 minutes under ultrasonic waves with a frequency of 35KHz, filter, and collect the filtrate;

Step 4: Add ethanol to make the concentration in the filtrate 90%, precipitate the bagasse polysaccharide solid, and vacuum dry to obtain the bagasse polysaccharide solid;

Step 6: Put the carbon molecular sieve into the silicon source and mix uniformly, and soak for 5 hours at 60°C; the mass ratio of the carbon molecular sieve to the silicon source is 1:3;

The silicon source is butyl orthosilicate;

Step 7: Drain the soaked carbon molecular sieve; then roast at 800°C for 2 hours, repeatedly pulverize, and pass through a 325-mesh sieve to obtain silicon-modified bagasse molecular sieve.

The pigment filler is wollastonite.

Comparative example 1

The nitrogen-doped graphene/molybdenum disulfide composite material in Example 1 was replaced with graphene oxide and molybdenum disulfide of equal mass, and the remaining proportions and preparation methods were unchanged.

Comparative example 2

The silicon-modified bagasse molecular sieve in Example 1 was replaced with unmodified bagasse molecular sieve, and the remaining ratio and preparation method were unchanged.

The powder coatings of Examples 1-3 and Comparative Examples 1-2 were applied to outdoor aluminum profiles. After testing, the curing conditions and the performance parameters of the coating film are shown in Table 1.

Table 1: Performance comparison test results of powder coatings of Example 1-3 and Comparative Example 1-2;

It can be known from the above test results that the powder coating of the present invention has very good leveling properties and acid resistance.

The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited to this. Anyone familiar with the technical field within the technical scope disclosed by the present invention, according to the technical solution of the present invention Equivalent replacements or changes to its inventive concept should all fall within the protection scope of the present invention.

Claims

A HAA low-temperature curing super-leveling weather-resistant powder coating, which is characterized in that it is composed of the following components by weight percentage: carboxyl polyester resin 60-70%, HAA curing agent 5.8-6.5%, leveling agent 1.8-3.0%, weather-resistant Additive 0.2-0.5%, dispersing aid 0.2-0.5%, benzoin 0.3-0.8% and the balance of pigments and fillers.
The HAA low-temperature curing super-leveling weather-resistant powder coating of claim 1, wherein the carboxyl polyester resin has a glass transition temperature of 57-62°C, a softening point of 105-120°C, and a viscosity of 18.0-32.0 Pa﹒ s (200°C), the acid value is 40-55 mg KOH/g; the HAA curing agent is β-hydroxyalkyl amide, and its equivalent is 82-90 g/eq.
The HAA low-temperature curing super-leveling weather-resistant powder coating according to claim 1, wherein the weather-resistant additive is silicon-modified bagasse molecular sieve.
The HAA low-temperature curing super-leveling weather-resistant powder coating according to claim 3, wherein the preparation method of the silicon-modified bagasse molecular sieve comprises the following steps:

Step 1: After a simple cleaning of the bagasse, mechanically crush it to 1-3mm, heat it to 190-260℃ with steam for 2-5min, and then release the pressure within 0.1-1s to make the bagasse cell wall The fiber is puffed to obtain puffed bagasse for use;

Step 2: Soak the puffed bagasse in 10-15 times the volume of enzyme solution and hydrolyze it at pH 4-5 and 60-65°C for 15-25 minutes;

Step 3: Treat the solution under ultrasonic waves with a frequency of 25-35KHz for 30-40 minutes, filter, and collect the filtrate;

Step 4: Add ethanol to make the concentration in the filtrate 80-90%, precipitate the bagasse polysaccharide solid, and vacuum dry to obtain the bagasse polysaccharide solid;

Step 5: Put the bagasse polysaccharide solids into a carbonization furnace, lay the raw materials naturally on a flat surface, raise the temperature to the carbonization temperature, and carbonize to obtain carbon molecular sieves;

Step 6: Put the carbon molecular sieve into the silicon source and mix evenly, and soak for 3-5h at 60-80℃;

Step 7: Drain the soaked carbon molecular sieve; then roast at 600-800° C., pulverize repeatedly, and pass through a 325-mesh sieve to obtain silicon-modified bagasse molecular sieve.
The HAA low-temperature curing super-leveling weather-resistant powder coating according to claim 4, wherein the silicon source is any one of ethyl orthosilicate, propyl orthosilicate or butyl orthosilicate.
The HAA low-temperature curing super-leveling weather-resistant powder coating according to claim 4, wherein, in the step 6, the mass ratio of the carbon molecular sieve to the silicon source is 1: (3-5).
The HAA low-temperature curing super-leveling weather-resistant powder coating of claim 1, wherein the dispersing aid is Cogine wetting agent 875.
The HAA low-temperature curing super-leveling weather-resistant powder coating according to claim 1, wherein the pigment filler is one or a mixture of anatase titanium dioxide, barium sulfate, wollastonite, and mica powder .
The HAA low-temperature curing super-leveling weather-resistant powder coating of claim 1, wherein the leveling agent is a nitrogen-doped graphene/molybdenum disulfide composite material.
The HAA low-temperature curing super-leveling weather-resistant powder coating according to claim 9, wherein the preparation method of the nitrogen-doped graphene/molybdenum disulfide composite material comprises the following steps:

Disperse 10-20 mg of graphene oxide in 200 mL of ethanol solution, perform ultrasonic dispersion, then stir and heat the mixture in an oil bath at 85-90°C, and then add 250-300 mg of sodium molybdate and 1.2-1.5 to the mixture g sodium sulfide, and adjust the pH value of the whole system to 3 with hydrochloric acid solution, remove the impurity ions and solvents to obtain a brown precipitate, collect the brown precipitate and dry it to obtain a precursor material; place the precursor material in a quartz boat , And placed in a tube furnace filled with nitrogen, heated at 550°C for 3-3.5 hours to obtain a nitrogen-doped graphene/molybdenum disulfide composite material.