Preparation method of low-molecular-weight cationic polyacrylamide hydrophilic coating

Abstract

The invention relates to a preparation method of a low-molecular-weight cationic polyacrylamide hydrophilic resin and coating. The low-molecular-weight cationic polyacrylamide is synthesised by virtue of aqueous solution polymerization and a two-phase temperature control process, wherein a monomer raw material comprises acrylamide, a quaternary ammonium salt cationic monomer, and hydroxyalkyl ester of acrylic acid or methylacrylic acid; an initiator is a composite initiator composed of manganese sulphate-sodium hydrogen sulphite and a water-soluble azo initiator; a temperature controlled reaction is carried out for 0.5-10h at 10-20 DEG C, and further carried out for 0.5-5h at 40-60 DEG C; the low-molecular-weight cationic polyacrylamide is compounded with waterborne polyurethane resin, a waterborne polyisocyanate curer, a coating additives, and pigments and fillers to obtain the hydrophilic coating; the hydrophilic coating is applied to the surface of a base material and then roasted and cured to form a hydrophilic coating layer.

Description

technical field

[0001] The invention relates to a method for synthesizing a low-molecular-weight cationic polyacrylamide hydrophilic resin and preparing a hydrophilic paint. Background technique

[0002] The wetting angle of water on the surface of the hydrophilic coating is generally required to be lower than 30°, and in some cases lower than 5°. Water can spread on the surface of the hydrophilic coating without forming water droplets and affecting the optical performance, and it increases the solid-liquid contact area and heat exchange area, and can also maximize the lubrication of the solid surface. Based on these performance characteristics, hydrophilic coatings have applications in anti-fog glass, self-cleaning walls, heat exchangers, biomaterials, etc.

[0003] According to the type of material, hydrophilic coatings are generally divided into inorganic coatings, organic resin coatings and composite coatings. The hydrophilicity of the inorganic coating is relatively g...

Examples

Embodiment 1

[0013] Manganese sulfate, sodium bisulfite, and azobisisobutylamidine hydrochloride aqueous solutions were prepared first, with concentrations of 20%, 10%, and 20% respectively. Add 500 kg of acrylamide, 50 kg of dimethyl diallyl ammonium chloride, 50 kg of hydroxyethyl methacrylate, 0.5 kg of metal ion chelating agent, and 1400 kg of deionized water into the reactor. Start stirring, nitrogen deoxygenation. After all the raw materials are dissolved, continue to fill with nitrogen for 30 minutes, then add 400 ml of manganese sulfate solution and 400 ml of azobisisobutylamidine hydrochloride solution, and continue to fill with nitrogen for 30 minutes. Then, feed into polyethylene plastic bags from the discharge opening of the reactor, and the capacity of the plastic bags is 20kg. Inject 200ml of sodium sulfite solution into each bag and seal the bag immediately. And put the plastic bag into water at a constant temperature of 10°C. After 2 hours, the plastic bag was tra...

Embodiment 2

[0015] Manganese sulfate, sodium bisulfite, and azobisisobutylimidazoline hydrochloride aqueous solutions were prepared first, with concentrations of 20%, 10%, and 20% respectively. Add 450 kg of acrylamide, 75 kg of dimethyl diallyl ammonium chloride, 75 kg of hydroxyethyl methacrylate, 0.3 kg of metal ion chelating agent, and 1400 kg of deionized water into the reactor. Start stirring, nitrogen deoxygenation. After all the raw materials are dissolved, continue to fill with nitrogen for 30 minutes, then add 200 ml of manganese sulfate solution and 500 ml of azobisisobutylamidine hydrochloride solution, and continue to fill with nitrogen for 30 minutes. Then, feed into polyethylene plastic bags from the discharge opening of the reactor, and the capacity of the plastic bags is 20kg. Inject 400ml of sodium sulfite solution into each bag and seal the bag immediately. And put the plastic bag into water at a constant temperature of 10°C. After 4 hours, the plastic bag was...

Embodiment 3

[0017] Take out 40kg low molecular weight cationic polyacrylamide aqueous solution from the plastic bag of embodiment 1, add in the mixing jar. Add 171kg of water-based polyurethane resin (35% solid content), 66kg of water-based polyisocyanate curing agent (38% solid content) and a small amount of defoamer to the tank. Adjust the viscosity with deionized water, apply 4 cups and measure the viscosity to be 18-24s. A hydrophilic coating is obtained. Spray the hydrophilic paint onto the epoxy resin coating as the substrate, dry it at 120°C for 30min, and measure the water contact angle as 8o.

technical field

[0001] The invention relates to a method for synthesizing a low-molecular-weight cationic polyacrylamide hydrophilic resin and preparing a hydrophilic paint. Background technique

[0002] The wetting angle of water on the surface of the hydrophilic coating is generally required to be lower than 30°, and in some cases lower than 5°. Water can spread on the surface of the hydrophilic coating without forming water droplets and affecting the optical performance, and it increases the solid-liquid contact area and heat exchange area, and can also maximize the lubrication of the solid surface. Based on these performance characteristics, hydrophilic coatings have applications in anti-fog glass, self-cleaning walls, heat exchangers, biomaterials, etc.

[0003] According to the type of material, hydrophilic coatings are generally divided into inorganic coatings, organic resin coatings and composite coatings. The hydrophilicity of the inorganic coating is relatively g...

Examples

Embodiment 1

[0013] Manganese sulfate, sodium bisulfite, and azobisisobutylamidine hydrochloride aqueous solutions were prepared first, with concentrations of 20%, 10%, and 20% respectively. Add 500 kg of acrylamide, 50 kg of dimethyl diallyl ammonium chloride, 50 kg of hydroxyethyl methacrylate, 0.5 kg of metal ion chelating agent, and 1400 kg of deionized water into the reactor. Start stirring, nitrogen deoxygenation. After all the raw materials are dissolved, continue to fill with nitrogen for 30 minutes, then add 400 ml of manganese sulfate solution and 400 ml of azobisisobutylamidine hydrochloride solution, and continue to fill with nitrogen for 30 minutes. Then, feed into polyethylene plastic bags from the discharge opening of the reactor, and the capacity of the plastic bags is 20kg. Inject 200ml of sodium sulfite solution into each bag and seal the bag immediately. And put the plastic bag into water at a constant temperature of 10°C. After 2 hours, the plastic bag was tra...

Embodiment 2

[0015] Manganese sulfate, sodium bisulfite, and azobisisobutylimidazoline hydrochloride aqueous solutions were prepared first, with concentrations of 20%, 10%, and 20% respectively. Add 450 kg of acrylamide, 75 kg of dimethyl diallyl ammonium chloride, 75 kg of hydroxyethyl methacrylate, 0.3 kg of metal ion chelating agent, and 1400 kg of deionized water into the reactor. Start stirring, nitrogen deoxygenation. After all the raw materials are dissolved, continue to fill with nitrogen for 30 minutes, then add 200 ml of manganese sulfate solution and 500 ml of azobisisobutylamidine hydrochloride solution, and continue to fill with nitrogen for 30 minutes. Then, feed into polyethylene plastic bags from the discharge opening of the reactor, and the capacity of the plastic bags is 20kg. Inject 400ml of sodium sulfite solution into each bag and seal the bag immediately. And put the plastic bag into water at a constant temperature of 10°C. After 4 hours, the plastic bag was...

Embodiment 3

[0017] Take out 40kg low molecular weight cationic polyacrylamide aqueous solution from the plastic bag of embodiment 1, add in the mixing jar. Add 171kg of water-based polyurethane resin (35% solid content), 66kg of water-based polyisocyanate curing agent (38% solid content) and a small amount of defoamer to the tank. Adjust the viscosity with deionized water, apply 4 cups and measure the viscosity to be 18-24s. A hydrophilic coating is obtained. Spray the hydrophilic paint onto the epoxy resin coating as the substrate, dry it at 120°C for 30min, and measure the water contact angle as 8o.