CN105199494A - Fluorocarbon resin coating and preparation method thereof - Google Patents

Abstract

A fluorocarbon resin coating and a preparation method thereof, relating to an architectural coating and a preparation method thereof, in which the hydroxyl group on the surface of silicon dioxide and the group on the surface of p-hydroxybenzoic acid are continuously polymerized in the presence of a catalyst in the present invention reaction, thereby modifying the hydrophilic groups on the surface of nano-silica, so that nano-silica can be better dispersed in organic solvents. The modified nano-silica fluorocarbon resin is used to prepare a composite coating. This method enables the modification of silica to be carried out under relatively mild conditions, which overcomes the disadvantages of previous silica modification requiring high temperature, high pressure, strong acid, and strong alkali. And the composite coating prepared by filling it has strong corrosion resistance, ultraviolet aging resistance, acid and alkali resistance and hydrophobic self-cleaning performance, and is a promising functional coating.

Description

A kind of fluorocarbon resin coating and preparation method thereof

technical field

The invention relates to an architectural coating and a preparation method thereof, in particular to a fluorocarbon resin coating and a preparation method thereof.

Background technique

Fluorocarbon resin has a strong C-F bond as the skeleton. Compared with other resins, it has better heat resistance, chemical resistance, cold resistance, low temperature flexibility, weather resistance and electrical properties. However, due to the short length of the C-F bond and the large bond energy of the fluorocarbon resin, its crystallinity is good, so it also has the disadvantages of non-adhesion and non-wetting. It can be seen from the above that if the fluorocarbon resin is directly used in the coating, although the coating has good protective performance in a short period of time, due to its non-adhesive and non-wetting characteristics, the coating will easily fall off, thus no longer affecting the substrate. It has a protective effect, which violates the original intention of using paint.

Although nano-SiO ₂ can better improve the shortcomings of fluorocarbon resin coatings, the surface atoms of nano-SiO ₂ particles are highly active, extremely unstable, and easy to agglomerate, and their dispersion in fluorocarbon coatings is poor. Therefore, the surface of nano- _SiO2 must be modified so that it can be better and uniformly dispersed in the fluorocarbon resin coating. Traditional nano-SiO ₂ modification methods are extremely demanding on conditions, and some methods such as high temperature, high pressure, strong acid, strong alkali, and high-cost coupling agent increase the cost of modification, which is not conducive to industrial production.

Contents of the invention

The object of the present invention is to provide a kind of fluorocarbon resin coating and preparation method thereof, the present invention is with nanometer SiO ₂ Modified fluorocarbon resin coating, both can keep the original excellent performance of fluorocarbon resin, can obtain excellent mechanical property again , thermal stability and other properties, but also has strong corrosion resistance, UV aging resistance, acid and alkali resistance, hydrophobic self-cleaning performance and heat and weather resistance.

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

A kind of fluorocarbon resin paint, this paint mass percentage is composed as follows:

Fluorocarbon resin 30%-40%; epoxy resin 5%-10%; p-hydroxybenzoic acid 5%-10%; solvent 30%-40%; leveling agent 0.5%-1%; defoamer 0.5% -2%; nano-silica 5%-8%; dispersant 2%-5%; catalyst 1.5%-5%.

The said fluorocarbon resin coating, the fluorocarbon resin used is trifluoro-type FEVE fluorocarbon resin.

In the above-mentioned fluorocarbon resin coating, the primary particle diameter of the nano silicon dioxide particles used is 25-30nm.

In the fluorocarbon resin coating, the volume ratio of xylene and ethylene glycol butyl ether in the mixed solvent is 2:3~4.

For the fluorocarbon resin coating, the leveling agents used are MF3077, RB505, and SC-333.

For the fluorocarbon resin coating, the defoamers used are GPE20 and SPA-202.

For the fluorocarbon resin coating, the dispersant used is a multi-component dispersant, which consists of HDI trimer HX and HDI biuret N75, and the percentage of the two is 10:7~8.

A preparation method of fluorocarbon resin coating, comprising the following preparation steps:

a Add 5%-8% of nano- _SiO2 particles to 5%-10% of a mixed solvent composed of xylene and ethylene glycol butyl ether, adjust the pH to 8-9 with Tris buffer, and then add 5% -10% of p-hydroxybenzoic acid and 1.5%-5% of pyridine, stirred for 2h, suction filtered, washed, and then dried at 120°C-200°C to obtain modified nano- _SiO2 particles;

b Pour 30%-40% fluorocarbon resin and 5%-10% epoxy resin into a three-necked flask, then add 25%-30% mixed solvent, ultrasonic 0.5-1.0h, constant temperature 40℃, 5%- Add 8% modified nano- _SiO2 particles to 3%-5% mixed solvent, ultrasonically disperse for 15-30min, slowly drop the obtained mixed solution into a three-necked flask, mechanically stir for 0.5-1.0h, and then ultrasonically 1- 2h;

c Add 0.5%-1% leveling agent and 0.5%-2% defoamer to the modified fluorocarbon resin, mechanically stir for 1-2h to disperse evenly, add 2%-5% dispersant, and then high-speed Disperse for 5-30 minutes to prepare the coating.

Advantage and effect of the present invention are:

1. Fluorocarbon resin coatings modified with nano- _SiO2 can not only maintain the original excellent properties of fluorocarbon resins, but also obtain excellent mechanical properties, thermal stability and other properties, and have strong corrosion resistance and anti-corrosion properties. UV aging resistance, acid and alkali resistance, hydrophobic self-cleaning performance and heat and weather resistance.

2. Use p-hydroxybenzoic acid to modify the surface of nano- _SiO2 , and use the hydroxyl group on the surface of silica to react with the carboxyl group on the surface of p-hydroxybenzoic acid, thereby modifying the hydrophilic groups on the surface of nano-silica, The nano-silica can be better dispersed in organic solvents, and the reaction conditions are relatively mild, which overcomes the disadvantages of high temperature, high pressure, strong acid, and strong alkali conditions required for silica modification in the past, and also avoids the use of silane coupling agents. Easy to cause side effects.

3. The present invention not only overcomes the shortcomings of traditional fluorocarbon resin coatings by using nano-SiO2 to modify fluorocarbon resin, but also obtains excellent mechanical properties and thermal stability, and simultaneously uses p-hydroxybenzoic acid to modify the surface of nano- _SiO2 The processing and operation are simple, the reaction conditions are easy to control, the repeatability is high, the production cost is reduced, and industrial production is easy to realize.

Description of drawings

Fig. 1p-Hydroxybenzoic acid synthesizes the mechanism diagram of polyester under pyridine catalysis;

Fig. 2 Mechanism diagram of polyester modified nano-silica.

Detailed ways

Embodiments of the present invention will be further described in detail through examples below, but the embodiments of the invention are not limited thereto.

a. Add 5% nano- _SiO2 particles to 5% xylene and ethylene glycol butyl ether in a mixed solvent with a volume ratio of 2:3, adjust the pH to 9 with Tris buffer, and then add 8% p-hydroxyl Benzoic acid and 5% pyridine were stirred for 2 hours, filtered with suction, washed, and dried at 150°C to obtain modified nano-SiO ₂ particles.

b. Pour 35% trifluoro-type FEVE fluorocarbon resin and 10% epoxy resin into a three-necked flask, then add 30% of the above mixed solvent; ultrasonic 1.0h, constant temperature 40°C. Add 5% of modified nano- _SiO2 particles to 5% of the above mixed solvent; ultrasonically disperse for 30min, slowly drop the resulting mixed solution into a three-necked flask, mechanically stir for 1.0, and ultrasonically for 2h.

c. Add 1% of MF3077 and 2% of GPE20 to the modified fluorocarbon resin, stir mechanically for 2 hours to disperse evenly; add HDI trimer HX and HDI biuret N75 with a volume percentage of 10:7, and disperse at high speed for 20 minutes, thereby Coatings are produced.

The above are only preferred implementations of the present invention, and are not intended to limit the present invention in any form. Any simple modifications or equivalent changes made to the above embodiments according to the technical essence of the present invention all fall within the scope of protection of the present invention. .

Claims (8)

1. A fluorocarbon resin coating, characterized in that, the coating mass percentage is composed as follows: fluorocarbon resin 30%-40%; epoxy resin 5%-10%; p-hydroxybenzoic acid 5%-10%; solvent 30%-40%; leveling agent 0.5%-1%; defoamer 0.5%-2%; nano-silica 5%-8%; dispersant 2%-5%; catalyst 1.5%-5%. 2. A fluorocarbon resin coating according to claim 1, characterized in that: the fluorocarbon resin used is trifluoro-type FEVE fluorocarbon resin. 3. A fluorocarbon resin coating according to claim 1, characterized in that: the primary particle size of the nano-silica particles used is 25-30nm. 4. A kind of fluorocarbon resin coating according to claim 1, is characterized in that: the volume ratio of xylene and ethylene glycol butyl ether in the mixed solvent is 2:3～4. 5. A fluorocarbon resin coating according to claim 1, characterized in that: the leveling agent used is MF3077, RB505, SC-333. 6. A fluorocarbon resin coating according to claim 1, characterized in that: the defoamer used is GPE20, SPA-202. 7. A kind of fluorocarbon resin coating according to claim 1, is characterized in that: used dispersant is multi-component dispersant, and it is composed of HDI trimer HX and HDI biuret N75, and both The percentage is 10:7~8. 8. A preparation method of fluorocarbon resin coating, characterized in that, comprising the following preparation steps: a Add 5%-8% of nano- _SiO2 particles to 5%-10% of a mixed solvent composed of xylene and ethylene glycol butyl ether, adjust the pH to 8-9 with Tris buffer, and then add 5% -10% of p-hydroxybenzoic acid and 1.5%-5% of pyridine, stirred for 2h, suction filtered, washed, and then dried at 120°C-200°C to obtain modified nano- _SiO2 particles; b Pour 30%-40% fluorocarbon resin and 5%-10% epoxy resin into a three-necked flask, then add 25%-30% mixed solvent, ultrasonic 0.5-1.0h, constant temperature 40℃, 5%- Add 8% modified nano- _SiO2 particles to 3%-5% mixed solvent, ultrasonically disperse for 15-30min, slowly drop the obtained mixed solution into a three-necked flask, mechanically stir for 0.5-1.0h, and then ultrasonically 1- 2h; c Add 0.5%-1% leveling agent and 0.5%-2% defoamer to the modified fluorocarbon resin, mechanically stir for 1-2h to disperse evenly, add 2%-5% dispersant, and then high-speed Disperse for 5-30 minutes to prepare the coating.