Factors Affecting Defoamers in Coating Formulations

Factor 1: Surface tension
The surface tension of the coating has a great influence on the defoaming agent. The surface tension of the defoaming agent must be lower than the surface tension of the coating. Otherwise, there is no defoaming and foam suppression. The surface tension of the coating is a variable factor, so a constant surface tension is required when using the defoamer, and then the surface tension variation factor is taken into account. propylene glycol used as raw materials for resin

Factor 2: The influence of other additives
Surfactants used in coatings are mostly functionally incompatible with defoamers. In particular, emulsifiers, wetting and dispersing agents, leveling agents, thickeners, etc., have an effect on the effect of the antifoaming agent. Therefore, we must pay attention to the relationship between different additives when mixing various additives, and choose the best balance point.

Factor three: baking temperature
The paint enters the high temperature baking at normal temperature, and the viscosity begins to drop back at the beginning. The bubbles can be moved to the surface. However, due to the evaporation of the solvent, the curing of the coating, and the increase of the surface viscosity, the foam tends to be more stable, trapped on the surface, and shrinks. Holes and pinholes, so the baking temperature, the fixed speed, and the solvent evaporation rate also have an effect on the defoaming agent.

Factor 4: solid content, viscosity, elasticity of the coating
High solids thick coating film, high viscosity, high elasticity coatings are very difficult to defoam. In these coatings, the defoaming agent is difficult to diffuse, the microbubbles become slow, the foam migration to the surface is reduced, and the foam viscoelasticity is large. There are many unfavorable defoaming factors. The foam in these coatings is quite difficult to eliminate, and it is best to use an antifoaming agent in combination with a defoaming agent.

Factor 5: Painting method and construction temperature
There are many coating construction methods, such as brush coating, roller coating, shower coating, blade coating, spray coating, screen printing and the like. The coating method used differs in the degree of foaming of the different coatings. Brushing and roller coating are more than spraying and scraping. When the temperature is higher than the temperature, the foam is more, but when the temperature is high, the foam is eliminated.

China's Biodegradable Plastic Production Accounts for About 25% of World Production Capacity

The United Nations Conference on Environment and Development, held in Rio de Janeiro, Brazil, in 1992, agreed to implement the sustainable development strategy. By 2015, the United Nations has formulated the “Transforming Our World: The 2030 Agenda for Sustainable Development”, and the completion of sustainable development has become An important task for the development of many countries, the State Council approved the release of the “China Implementation of the 2030 Agenda for Sustainable Development Country Program” in 2016 to provide a guide to China's implementation of the sustainable development agenda. dimethyl carbonate in the paint

Under the global trend and environmental protection framework, China's plastics processing industry actively responds to the situation and strives to find a sustainable development path and achieve positive results. In the "Guidelines for the Development Plan of the 13th Five-Year Plan for Plastics Processing Industry" and the "Guiding Opinions on the Progress of the 13th Five-Year Plan for Plastics Processing Industry", China Plastics Association has always regarded the "three-in-one-micro" of ecological construction as an industry. The direction of technological progress; in the construction of platforms and service industries, including the Science and Technology Innovation Year, experts, academics, science and technology conferences, China International Plastics Exhibition, etc., all of which take ecological development as an important content; in special work and sub-sectors of branches In the activity, ecological and green development are also important components, such as: the replacement of lead salt stabilizers in the PVC industry, the active management of VOCs emissions in the field of artificial leather synthetic leather and composite film, and research and promotion of water-based synthetic leather. Water-based inks and adhesives have done a lot of work in solving the problems found in the ecological development of different sub-sectors. The industry vigorously develops and produces environmentally friendly materials and products, and has made great progress in the development of biodegradable mulch films and degradable disposable plastic products for biomass plastics and bio-based plastics. At present, the production of biodegradable plastics in China accounts for about 25% of the world's production capacity, which is equivalent to the proportion of Chinese plastics in world production capacity.

China Uses 30 Million Tons of Recycled Plastics Every Year

Plastics have abundant raw materials, low cost, easy molding and processing, high productivity, light weight of components, high specific strength, good wear resistance, self-lubricating, corrosion resistance, good electrical insulation, good sound absorption and shock absorption. . Widely used in industrial and agricultural production, transportation, aviation, aerospace, high-speed rail, automotive, building materials, home appliances, electrical and electronic, packaging, medical and other fields. Today, plastic products have become an important part of the economy, society and people's daily lives. People can't live without plastics, and plastics make people's lives better.

It can be seen that the demand for plastics in the economy and society is enormous, and most plastics are renewable. At present, China is also striving to recycle and use waste plastics while developing the plastics industry at a high speed. The recycling and recycling of used plastics in the country is about 30 million tons per year, accounting for more than 30% of plastic consumption. Among them, the recovery rate of EPS plastics is about 90%, and the recycling of plastic bottles is also among the best in the world, making great contributions to the world's plastic waste treatment and environmental protection. dimethyl carbonate in the field of pesticides

A circular economy model of production-use-recycling-reuse is realized through organized recycling and development and utilization of green plastic resources. Not only can it create higher economic value, but it also reduces the pressure on resources and the environment. The plastics processing industry provides a variety of energy-saving and environmentally-friendly production materials and green and ecological life-saving plastic products in various fields of the national economy, which has become a concentrated expression of the green concept.

Usage of PG

Propylene glycol is miscible with water, ethanol and various organic solvents. Propylene glycol can be used as raw material for unsaturated polyester resin.

1. Propylene glycol is used as raw materials for resin, plasticizer, surfactant, emulsifier and demulsifier, as well as antifreeze and heat carrier.

2. Propylene glycol is used as fixed solution, solvent, antifreeze, plasticizer and dehydrating agent for gas chromatography.

3. Carrier solvent;Wetting agents;Moisturizing factor;Anticaking agent.Antioxidants;Tissue improvers;Surfactant;Stabilizing agent;Thickener;Dough conditioner;Emulsifier;Seasoning;Excipients;Processing AIDS.GB 2760 ~ 96 is as food processing additives.It mainly used for various spices, pigments, preservatives solvent, vanilla beans, roasted coffee granules, natural spices extraction solvent.Humectant and softener for confectionery, bread, packaged meats, cheese, etc.

4. Propylene glycol is the intermediate of the fungicide phenyl ether metronidazole.

5. As a solvent, propylene glycol can dissolve preservatives, pigments, antioxidants and other food additives that are difficult to dissolve in water, and then add food;It has stronger hygroscopicity,and protect wet and antifreeze action to food.

6. Propylene glycol is an important raw material of unsaturated polyester, epoxy resin, polyurethane resin, the amount of this aspect accounts for about 45% of the total consumption of propylene glycol, this unsaturated polyester is widely used in surface coating and reinforced plastics.Propylene glycol is viscous and hygroscopic, and non-toxic, so it can be used in the food, medicine and cosmetics industry widely as a hygroscopic agent, antifreeze, lubricant and solvent.In the food industry, propylene glycol and fatty acid react to form propylene glycol fatty acid ester, which is mainly used as food emulsifier. Propylene glycol is a good solvent for condiment and pigment.Propylene glycol in the pharmaceutical industry is often used to manufacture all kinds of ointment, ointment solvent, softener and excipient, etc., because propylene glycol and various spices have better mutual solubility, it also used as cosmetics solvent and softener and so on.Moreover, Propylene glycol is used as a tobacco humidifier, anti-mildew agent, food processing equipment lubricating oil and food marking ink solvent.The aqueous solution of propylene glycol is an effective antifreeze.

7. Propylene glycol is used as drug carrier and granular drug agent.It can be used as moisturizer, softener and solvent in cosmetics.Tobacco industry can be used as tobacco flavor, tobacco moisture agents, preservatives.In the food industry as a flavor, food coloring solvent, food packaging softener, food anti-stick agent.It can be used for the production of unsaturated polyester resin, plastic plasticizer, dehydrating agent, surfactant, curing agent, binder raw materials.And it can be used in paint, pesticides, coatings and other industries.

Usage of DMC

Dimethyl carbonate is insoluble in water, but can be mixed with alcohol, ether, ketone and almost all organic solvents. DMC, with low toxicity, was listed as a non-toxic product in Europe in 1992. It is an environment-friendly chemical material in line with the requirements of modern "clean technology".

Dimethyl carbonate (DMC) is an important organic chemical intermediate. Because its molecular structure contains carbonyl, methyl, methoxide and carbonyl methoxide, it can be widely used in organic synthesis reactions such as carbonylation, methylation, methoxylation and carbonyl methylation. It used in the production of polycarbonate, isocyanate, polyurethane, polycarbonate glycol, allyl diethylene glycol carbonate, methyl amino formic acid naphthalene ester (carbaryl), benzene methyl ether ammonium, four methyl alcohol, long chain alkyl carbonate, carbon hydrazide, malonic ester, propylene urethane, diethyl carbonate, three phosgene, furazolidone, hydrazine methyl formate, aniline methyl formate and other chemical products.

1、Instead of phosgene to synthesize polycarbonate

2、As a non-toxic or low-toxic solvent, alternative to the traditional toxic solvents such as toluene, xylene, acetone, butanone, ethyl acetate, butyl acetate, etc., DMC used in the paint (nitro paint, furniture paint, automotive paint) and adhesive industry.

3、In the field of pesticides, DMC is mainly used to produce methyl isocyanate and then some carbamate pesticides. The varieties of pesticides that can be produced include: carbaryl, baylor, carbaryl, budweiser, methadol, etc.

4、In the part of medicine, it is mainly used to synthesize anti-infective drugs, antipyretic and analgesic drugs, vitamin drugs and drugs for the central nervous system. DMC is mainly used for the synthesis of ciprofloxacin, norfloxacin (norfloxacin), piperic acid, ciprofloxacin lactate and other raw materials, mainly used as methylation agent.

5、Replacing MTBE as gasoline additive to improve octane value of gasoline (this use is mainly in China)

6、Lithium battery electrolyte 
Lithium battery electrolyte is mainly composed of organic solvents, such as propylene carbonate, (vinyl carbonate), (diethyl carbonate), (ethyl methyl carbonate).

7、Developer 
Tetramethyl alcohol amine can be produced by dimethyl carbonate. P type photoresist developer which is widely used as photoresist developer in large scale advanced integrated circuit lithography.

Usage of PC by Evergreen

Propylene carbonate (propylene glycol carbonate) is soluble in water and carbon tetrachloride, mixes with ether, acetone, benzene and other miscible, is a good polar solvent, nature is stable, non-toxic solvent, pure, no corrosion of carbon steel equipment, used for removal of natural gas, petroleum cracking gas, carbon dioxide and hydrogen sulfide in synthetic ammonia feed gas, is an ideal solvent, can also be used as plasticizer, spinning solvent or water solvent dye pigment dispersant, oily solvent and extracting agent of olefins and aromatics. Based on people's concern for resources and environmental problems and the social demand for sustainable development, green chemistry with the goal of eliminating pollution, making rational use of resources and achieving sustainable development has become the hot spot and frontier of current chemistry research. Many processes will be replaced by clean and environmentally friendly processes. The continuous promotion and application of dimethyl carbonate, polycarbonate and polyurethane in its downstream products will inevitably increase the market demand for propylene carbonate.

At present, the most important is used to remove carbon dioxide and hydrogen sulfide from natural gas, oil pyrolysis gas, oil field gas and synthetic ammonia conversion gas.In the electronic industry, it can be used as an excellent medium for high-energy batteries and capacitors, and as a solvent and plasticizer for polymers.

Propylene carbonate can also be used as an oil solvent and as an extraction agent for olefins and aromatics.In the textile industry can be used as synthetic fiber additives and fixatives, spinning solvents or water-solvent dye pigment dispersant; In addition, it is an extremely versatile organic synthesis of raw materials and intermediates.

Usage of PO

Propylene oxide (PO) is the third largest propylene derivative except polypropylene and acrylonitrile. It is an important basic organic chemical synthesis raw material, mainly used for the production of polyether and propylene glycol. It is also the main raw material of the fourth generation detergent non-ionic surfactant, oilfield demulsifier, pesticide emulsifier, etc. Epoxypropane derivatives are widely used in automobile, construction, food, tobacco, pharmaceutical and cosmetic industries. It has produced nearly 100 kinds of downstream products and is an important raw material of fine chemical products. 

Developed for the first time of propylene oxide, carbon dioxide and methanol synthesis of dimethyl carbonate reaction is of highly active and stable KOH / 4 a molecular sieve solid catalyst, the reaction temperature and catalyst active component of KOH load factors effect the performance of the catalyst. Under the optimized experimental conditions, propylene oxide can completely transform, the yield of dimethyl carbonate is 16.8% from experimental results that the product dimethyl carbonate by carbon dioxide and propylene oxide and addition, propylene carbonate, and then the ester exchange reaction with methanol generated, Methanol is a cocatalyst for the synthesis of propylene carbonate from propylene oxide and carbon dioxide.

Propylene oxide is mainly used for production of polyether polyols, propylene glycol, etc., all kinds of nonionic surfactant of polyether polyols is the production of polyurethane foam, insulation materials, elastomers, adhesives and coatings and other important raw materials, all kinds of nonionic surfactants in oil, chemical, pesticide, textile, daily chemical and other industries widely used.At the same time, propylene oxide is also an important basic chemical raw material.