Long-acting Plastic Antifogging Agent Polyglyceride Fatty Acids Series

Long-acting plastic antifogging agent is a kind of dispersant with large molecular weight containing hydrophilic groups. It consists of molecules with certain molecular weight. When coated on the surface of transparent objects, a coating will be formed. The hydrophilic groups in the coating can absorb water molecules in the air, wet and diffuse on the surface of transparent objects to form water film (rather than water droplets), so that the light passing through the objects will not scatter and avoid it. No fogging. At present, the main ingredients of antifogging agents on the market are surfactants, such as xylitol ester, sorbitol monopalmitate, lauric acid or hard resin glycerin monoester, etc. They are instant antifogging agents. The antifogging duration is short and the adhesion is poor. Generally, only a few days or more, the antifogging effect disappears immediately after being wiped or washed by water, so they can not be used as long-term antifogging agents. Use. According to the characteristics of polyglyceride, our unit has developed new long-acting antifogging agents, such as polyglyceride ester, polyglycerin stearate and polyglycerin coconut oleate, which have the characteristics of large molecular weight, good lubrication effect, good moisturizing effect and long antifogging effect.

Chinese Name: Long-acting Antifogging Agent Polyglyceride Fatty Acid Ester

English name: Long-acting antifogging agent polyglyceride fatty acid ester

Appearance: Colorless to yellowish liquid to solid.

Application: The fourth generation antifogging and fresh-keeping masterbatch produced by long-acting antifogging agent polyglyceride fatty acid ester can not only be used for the preservation and transportation of fruits and vegetables at room temperature, but also for the preservation of vegetables, fruits and meat under refrigeration conditions (such as refrigerators and refrigerators). The defect of unsatisfactory anti-fogging effect of general anti-fogging masterbatch is eliminated when it is close to zero, and wax deposition of cooling roll will not occur in the production of tape casting film.

The advantages of the new product of the fourth generation anti-fogging masterbatch for blow-moulding and casting film of food preservation polyethylene produced by long-acting plastic antifogging agent polyglyceride fatty acid ester are that the antifogging agent in the co-extruded multi-layer film or single-layer film plays a faster role than before. Effectively reduce water vapor, and condense into liquid water film, so that the film is more transparent and clear; high cost-effective, less dosage, can significantly increase the transparency and surface gloss of the film. After adding masterbatch, the processing temperature of the film decreases by 10-20 C, and the film can be mixed evenly in proportion.

Technical quality index: melting index: about 8g/10min~10g/10min (190 C, 2160g)

Content of active ingredients: > 99% specific gravity: about 0.96-1.02g/cm3 moisture content: <0.1% appearance: colorless to yellowish liquid to solid.

classification

Antifogging agents can be divided into external antifogging agents and internal antifogging agents. Polyglyceride fatty acid esters with high molecular weight can be used as long-acting external antifogging agent and long-acting internal antifogging agent.

External antifogging agent is applied by spraying or impregnation. Its advantage is that the antifogging agent is concentrated on the surface and can take effect immediately when the amount is small. The disadvantage is that it can easily disappear from the surface of plastic film, so it usually has only short-term effectiveness. However, the external antifogging agent is easy to use and low cost, and it is widely used in agricultural greenhouses.

Internal antifogging agent has long-term effect and is widely used. When the internal antifogging agent is added to the polymer matrix, it can migrate to the surface of the plastic film. After the surface antifogging agent is lost due to the abrasion of the washing machine, the antifogging agent inside the polymer is relocated to the surface of the material to supplement until all the antifogging agent contained in the plastic is exhausted. Its characteristic is that it has a long efficiency, but the processing cost and the dosage of antifogging agent are higher.

Mechanism of action

The mechanism of antifogging agents is to use the special molecular structure of polyol-type non-ionic surface activity. One is hydrophilic group, the other is lipophilic group. The hydrophilic group absorbs water molecules in the air and reduces the surface tension, thus reducing the contact angle between water molecules and the surface of transparent objects, so that water molecules have not formed small droplets on the surface of transparent objects. It will wet and diffuse on the surface of transparent objects, forming an ultra-thin transparent water film, which will no longer scatter the incident light, nor interfere with the line of sight, thus playing a fog-proof role. The common types of polyol non-ionic surfactants are glycerol ester, polyglyceride fatty acid ester, dehydrated sorbitol ester, ethoxy derivatives, nonylphenol ethoxide, ethoxy alcohol, etc. [1]

Because the main component of antifogging agent is surfactant, the molecular structure of surfactant is amphiphilic: one end is hydrophilic group, the other end is hydrophobic group. Hydrophilic groups can absorb water molecules to form water film, showing good anti-fogging effect; hydrophobic groups lead to water film fluidity, and lead to the loss of surfactants together, so that the anti-fogging effect of anti-fogging agent also quickly lost, greatly shortening the anti-fogging time of anti-fogging agent. On the other hand, surfactants are also sensitive to water (very soluble in water). When the surface of transparent objects coated with antifogging agent is washed by water, the antifogging agent coating on the surface of them, surfactant, will be quickly dissolved in water and carried away by flowing water, and its antifogging function will be lost. Moreover, the antifogging agent is coated on the surface of transparent objects. Because of the interference of hydrophobic groups, it does not form a continuous film. It only adsorbs on the surface of objects and does not form a firm adhesion. The antifogging agent is wiped off with a cloth and the antifogging function is lost. So water washing and wiping are the antifogging agents.

Although the antifogging effect of antifogging agent is very good, the biggest limitation of antifogging agent is that the antifogging time is short, the antifogging agent can not be wiped, and the antifogging agent can not be washed.

Main application

Packaging plastic film

When food (e.g. meat products) are placed in plastic plates at room temperature, wrapped in plastic film, and stored in refrigerators at about 4 degrees Celsius, the air enclosed in the packaging is cooled, so the water vapor in the air is in supersaturated state, and the water vapor condenses into droplets on the surface of the plastic film, seriously affecting the beauty of the packaging. Therefore, anti-fogging is necessary, otherwise, not only the aesthetic feeling of the packaging is reduced, but also the quality of the products may be deteriorated.

Agricultural film

Agricultural greenhouse film is an important facility for agricultural production. Because the temperature and humidity in the greenhouse film are higher than outside, the water vapor in the air condenses on the surface of plastic film, and the formation of water droplets makes the film white and diffuse, which affects the transmittance of light, and is also very harmful to the growth of plants. Therefore, antifogging agent is used to ensure the penetration of sunlight and promote the growth of plants.