Current Situation and Development of Polyurethane Adhesives for Domestic Packaging

At present, although the overall development trend of adhesives is non-organic solvation, polyurethane solvent-based adhesives, due to their excellent process and adhesive properties, especially non-organic solvent-based adhesives, cannot fully meet the solvent-based level at present, and solvent-based polyurethanes. The adhesive will still be present for a longer period of time.

In Europe, the United States, Japan and other developed countries or regions, the use of solvent-based polyurethane adhesive in the field of dry compounding more than 60%. Since 1980, China has begun to introduce Japanese composite film production technology and equipment. It is estimated that the dry film production line is now over 300, and the polyurethane adhesive is used over 35,000 tons per year. The solvent-based two-component polyurethane adhesive that was first applied in the composite packaging industry in China was produced by the Beijing Chemical Industry Research Institute in 1984 from the former Federal Republic of Germany. The main product is a low viscosity, high solids (75%) polyurethane adhesive. . Since then, various models of domestic composite equipment have entered the market, and domestic manufacturers and research institutes have successively developed a variety of compatible solvent-based two-component polyurethane adhesives, mainly low-solid-content (15%-50%), high-viscosity products.

In general, low-viscosity, high-solids products have low viscosity, can be coated at a high concentration of 40% or more, have low solvent consumption, are environmentally friendly, have a low overall cost, and have high transparency and strength, but they are Equipment, processes, and raw material control all have higher requirements, and various defects such as poor strength are likely to occur when the application is not appropriate. This product is suitable for use in a composite manufacturer with a certain scale. Low solid content (15% -50%), high viscosity products with high initial viscosity, for domestic production. The adaptability of the composite machine is good, but the transparency is slightly inferior, the solvent is used too much, the environment is not friendly, and the comprehensive cost is high. Such products are suitable for medium and small scale compound manufacturers.

At present, from the perspective of China's overall adhesive market, it has the following characteristics:

Multinational companies are promoting both functional and non-organic solvent-based products in China, seizing high-end markets, and direct selling or cooperating in the production of common polyurethane gel slurries for the general market. Domestic enterprises, after years of digestion and absorption and independent development, many companies have mastered ordinary polyurethane adhesive production technology and production, the current production is estimated at 30,000 tons / year, about 30 species, these manufacturers become the main raw material suppliers. Some domestic companies with strong technical capabilities have been able to produce high-performance functional or non-organic solvent-based products. The domestic production of functional solvent-based adhesives, such as high-temperature cooking type, resistance to media type, resistance to slip agent and other products have been published one after another, make up for the blank. In the area of ​​non-organic solvent type polyurethane adhesives, despite the introduction of new products, there is a certain gap between process operation and application performance and solvent-based products, and the cost is also at a disadvantage, and the application and promotion situation is still relatively high compared with developed countries. Big gap.

With China's accession to the WTO and the growing awareness of environmental protection in China, technical barriers such as environmental protection will become prominent. Composite film manufacturers and adhesive manufacturers should work together to improve the technical level of composite products.

Comprehensive inspection and analysis of the current domestic polyurethane adhesives industry, the next development trend of polyurethane adhesives is: the domestic common compound solvent-based two-component polyurethane adhesive production technology has been fully grasped, some manufacturers mature technology, stable quality, can completely replace the import The production technology of two-component solvent-based two-component polyurethane adhesives for retort cooking of some domestic manufacturers has passed. Many years of popularization and application have shown that the product quality is stable and the price is reasonable. It can replace imported products; special adhesive for aluminum plating film and anti-slip agent function glue. Such products are highly targeted and have outstanding performance and should be promoted.