Urea formaldehyde adhesive
It is mainly used in wood processing. Due to the high formaldehyde emission in urea formaldehyde glue, the environmental pollution of wood-based panel is caused. According to the determination of national wood-based panel testing center, the formaldehyde emission of most wood-based panels in China is more than 30mg / 100g, which is much higher than the gbl8580-2001 standard issued by the state. At present, many urea formaldehyde glue manufacturers are actively improving the process and formula, using methods such as increasing formaldehyde catcher to reduce the formaldehyde content by every means, so as to make it reach or lower than the national standard. However, some workshop enterprises with small production scale, low level of production technology and simple equipment cannot meet the national standards and can only be eliminated.
Polyvinyl formal (107 glue)
It is mainly used for interior wall coating, decoration, wallpaper and cement reinforcer, etc. according to the determination, the content of free formaldehyde in most 107 adhesives is 10-50g / kg, which is 10-50 times of the compulsory standard gb18583-001 (formaldehyde is less than 1G / kg) issued by the state. The enforcement of gb18583-001 will lead to many small and medium-sized 107 rubber production plants stop production or change production. In the future, it will be replaced by "interface agent" or other adhesives that do not contain formaldehyde at all. From the perspective of the use in Beijing and other places, the interface agent not only has the advantages of simple production, good adhesiveness and 107 adhesive, but also has the same price as 107 adhesive, which is worth promoting.
Neoprene and SBS
Neoprene glue (commonly known as universal glue) is mainly used in interior decoration, decoration, wood processing, luggage and shoemaking and other industries, with wide application and large market demand. Chloroprene rubber contains a lot of volatile organic solvents. At present, there are many kinds of organic solvents used in chloroprene rubber, but they can be generally divided into low toxic and non-toxic solvents, such as ethyl acetate, 120 gasoline, acetone, etc., and toxic and more toxic solvents, such as benzene, toluene, halogenated hydrocarbon, etc.
Benzene solvent with high toxicity has long been banned in developed countries such as Europe, America and Japan. However, due to its low price in China, many manufacturers still use it. According to the determination of national adhesive quality inspection center, many chloroprene rubber products contain 104g / kg benzene and 300-500g / kg toluene, which seriously pollute the environment and harm the health of consumers. This time, the compulsory standard GB18583-2001 issued by the state banned the chloroprene rubber used for interior decoration with benzene as the solvent, and also made a strict limit on toluene and total volatile organic compounds.
At present, many manufacturers are adjusting the product structure. Some use SBS glue to replace neoprene glue, and SBS glue will have a large growth. However, it is worth noting that some manufacturers use halogenated hydrocarbon with high toxicity as solvent (such as 1, 2-dichloroethane, dichloromethane, etc.) when they produce SBS glue, which will cause new harm to consumers.
Water based adhesive and hot melt adhesive
Water-based adhesives mainly include acrylate emulsion, polyvinyl acetate emulsion and VAE emulsion. They are widely used in many industries such as interior and exterior wall coatings, wood and paper processing, carpet, textile, adhesives and so on. In 2001, the total output was 859000 tons, an increase of 13.2% over 2000. In recent years, the demand of hot-melt adhesive and hot-melt pressure-sensitive adhesive in footwear industry, trademark advertising industry and medical and health industry has increased rapidly. In 2001, the output reached 65000 tons, an increase of 12.1% over 2000. Because these two kinds of adhesives do not contain organic solvents, there is basically no discharge of three wastes in the process of production and use, and they do not pollute the environment. They are really environmentally friendly products and are increasingly favored by people. They are the fastest growing adhesives of all kinds.
Polyurethane and epoxy adhesives
In recent years, due to the rapid development of China's automobile manufacturing industry, construction industry, shoemaking industry, household electrical appliances industry and food packaging industry, the demand for polyurethane adhesive, polyurethane sealant and sealing structural adhesive has increased, so the annual growth rate of polyurethane adhesive has remained above 10%. At present, polyurethane adhesives in China are basically solvent based, containing not only a large number of organic volatiles, but also a small amount of free toluene diisocyanate (TD1). According to the compulsory standard of gbl8583-2001 published by the state, the limit of total volatile organic compounds in polyurethane adhesives for interior decoration is less than 750g / L, and the content of TD1 is less than 10g / kg.
Because of the poor toughness, expensive price and difficult production of epoxy resin adhesive, its popularization and application are affected. In recent years, the toughness and mechanical properties of epoxy resin adhesive modified by polyurethane, acrylate and organosilicon have been greatly improved.