Present Situation And Development Emphasis Of Synthetic Adhesives In China

China's synthetic adhesives manufacturing enterprises are relatively scattered, there are more than 2000, and hundreds of specialized production of generic varieties such as urea formaldehyde resin adhesives, polyvinyl acetate adhesives, acrylic resin adhesives and so on.

Urea formaldehyde resin, phenolic aldehyde and melamine formaldehyde adhesive are mainly used in wood processing industry, and the formaldehyde emission after use is higher than international standards.

Polyacrylic acid resin: mainly used for producing pressure sensitive adhesives, and also for textile and construction.

In recent years, several production lines of pressure sensitive adhesive products imported from abroad have promoted the development of polyacrylic acid production technology in China.

Polyurethane adhesive: it can bond various kinds of materials, and can maintain the physical and chemical properties of materials at low temperature or ultra-low temperature after being bonded. It is mainly used in shoes, packaging, automobiles, magnetic recording materials and other fields.

In recent years, the annual output of domestic polyurethane adhesives has increased by an average of 30%.

There are about 170 factories in China producing more than 100 kinds of adhesives of different specifications.

Hot melt adhesive: according to different raw materials, it can be divided into EVA hot-melt adhesive, polyamide hot-melt adhesive, polyester hot-melt adhesive, polyolefin hot melt adhesive, etc.

At present, EVA hot melt adhesive is mainly produced and used in China.

The main raw materials of polyolefin series adhesives are ethylene series, SBS and SIS copolymers.

Epoxy resin adhesive: it can bond metal to most non-metallic materials and is widely used in buildings, automobiles, electronics, electrical appliances and household products.

There are more than 100 factories producing epoxy resin adhesives in China, and the distribution is more dispersed. The annual output is about 10 thousand tons.

Silicone adhesive: it is a kind of sealing adhesive, which has the characteristics of cold resistance, heat resistance, aging resistance, waterproof, moistureproof, high fatigue strength, small permanent deformation, non-toxic and so on.

In recent years, such adhesives have been developing rapidly in China, but at present, the raw materials of organic silicone adhesives rely on imports.

Synthetic adhesives: mainly used in wood processing, construction, decoration, automobile, footwear, packaging, textile, electronics, printing and binding.

At present, China imports nearly 200 thousand tons of synthetic adhesives every year, including hot-melt adhesives, silicone sealing adhesives, acrylic acid adhesives, polyurethane adhesives, PVC plastic adhesives for automobiles, etc.

At the same time, the annual export of synthetic adhesives is about 20 thousand tons, mainly polyvinyl acetate, polyvinyl acid formaldehyde and pressure sensitive adhesives.

Adhesives for wood processing: medium density fiberboard, plasterboard, plywood and particleboard.

Adhesives for buildings: mainly used for building decoration, sealing or bonding between structures.

With the development of the construction industry and the development of high-rise buildings and interior decoration, the amount of building adhesives has increased dramatically.

In 2000, the consumption of adhesives for building adhesives in China was more than 600 thousand tons.

But experts believe that the product structure of such adhesives in China needs to be adjusted.

In China, adhesives for building decoration, such as polyvinyl acetate, polyacrylic acid, VAE emulsion and so on, can basically meet the needs. However, building sealing adhesives and structural adhesives still need to be imported from abroad.

Sealing adhesive: mainly used for connection of door, window and prefabricated housing.

In the past, when tung oil and lime were mixed as sealants, it is now stipulated that synthetic adhesives must be used for buildings over two storeys.

High grade sealant is silicone and polyurethane adhesive, medium grade is neoprene adhesive, polyacrylic acid and so on.

In China, silicone adhesives and polyurethane sealant should be the direction of development in the market of building adhesives. At present, the sales volume of building adhesives is about 30%.

Adhesives for building structures: mainly used for connection between structural units.

For example, external repair of reinforced concrete structure, metal reinforcement and construction, and construction site construction, epoxy resin adhesive is generally considered.

Adhesives for automobiles can be divided into 4 types: vehicle body, interior decoration, windshield and adhesive for vehicle chassis.

At present, the annual consumption of automotive adhesives is about 40 thousand tons, of which the largest uses are PVC adhesives, neoprene adhesives and asphalt series adhesives.

Adhesive for shoemaking: annual consumption is about 125 thousand tons, of which 110 thousand tons of neoprene adhesive, and 15 thousand tons of polyurethane adhesive.

Because chloroprene rubber adhesives need benzene as solvent, benzene is harmful to human body, so we should limit the development. Therefore, in order to meet the development needs of the footwear industry, the use of polyurethane adhesive will be the direction.

Adhesives for packaging: mainly used for making pressure sensitive tapes and pressure sensitive labels, and gluing the surface of packaging materials such as paper, plastic and metal.

The adhesive for paper packaging material is polyvinyl acetate emulsion.

The adhesive for plastic and metal packaging materials is polyacrylic acid emulsion, VAE emulsion, polyurethane adhesive and cyanoacrylate adhesive.

Adhesives for Electronics: less consumption, less than 10 thousand tons per year, most of which are used in integrated circuits and electronic products, mainly using epoxy resin, unsaturated polyester resin and organic silicone adhesive.

The adhesive for 5 micron thick electronic components can be supplied by ourselves, but the adhesive for electronic components of 3 micron thickness must be imported from abroad.

In 2000, the demand for synthetic adhesives in China was about 2 million 400 thousand tons, of which the applications in automobile, electronics, packaging and building areas increased considerably.

Environmentally friendly adhesives such as silicone, polyurethane, epoxy resin and other high performance adhesives as well as hot-melt adhesives, VAE emulsion, acrylic emulsion and other environment-friendly adhesives have increased considerably.

In view of the actual situation of China's synthetic adhesives industry, the industry believes that the focus of future development is to develop urea formaldehyde resin adhesive with low formaldehyde emission.

The yield of this kind of adhesive is currently about 1 / 3 of the total output, but the production technology level is general, so we must further improve the technology and reduce the production cost.

The two is the development of polyamide adhesive.

Polyamide adhesives have a wide range of applications in the fields of automobile, building, shoe making and packaging. This is a kind of variety with a very promising future and a larger potential market.

The three is silicone adhesive.

At present, the developed countries in the world mainly use silicone sealing adhesives in the construction industry, and gradually become the leading species.

The four is polyvinyl chloride adhesive for automobile.

In automobile production, PVC plastic adhesive is already the main adhesive, and the domestic demand is about 20 thousand tons in 2000.

The five is hot-melt adhesive.

Hot melt adhesives are mainly used in the field of clothing, packaging and printing. Domestic output is relatively small, and some of them rely on imports.

The six is epoxy resin adhesive.

At present, the quality of domestic electronic and building epoxy adhesives is poor and mainly depends on imports.

The seven is polyvinyl butyral adhesive for safety glass.

Such adhesives are mainly used in the construction and automotive industries.