Polyvinyl butyral, also known as PVB, has good flexibility and transparency. It also shows good performance in terms of impact resistance, hydrolysis resistance, heat and cold resistance characteristics.
2. Preparation of polyvinyl butyral resin
Polyvinyl butyral resin is mainly composed of aldehydes and polyvinyl alcohol in the The product is obtained by condensation of aldehyde compounds with polyvinyl alcohol under the action of an acid catalyst. In terms of production methods In terms of production methods, polyvinyl butyral resins can be prepared mainly by one-step and Two-step methods.
2.1 One-step method
Depending on the state at the end of the reaction, it can be specifically subdivided into one-step dissolution and One-step precipitation method. In the production of polyvinyl butyral resin by the one-step dissolution method, the polyvinyl alcohol powder can be dissolved in the final product and the reaction initially The reaction is initially carried out in a non-homogeneous phase, and during the reaction, the resulting polyvinyl butyral Butyraldehyde is dissolved in the solvent and the later reaction is carried out in the homogeneous phase. With In the case of the one-step precipitation method, the body of vinyl acetate is polymerized to produce vinyl acetate. When butyraldehyde is added near the end of the hydrolysis reaction, the acidic catalyst, the acetal reaction occurs and polyvinyl butyral is precipitated as a
The precipitate is precipitated.
2.2 Two-step method
The two-step method refers to the use of a catalyst to promote the reaction of aldehyde to obtain polyvinyl butyral aldehyde, which can also be divided into dissolution and precipitation methods. The two-step dissolution method refers to is obtained by hydrolysis of PVAc in advance, the vinyl acetate is blended into methanol The solution is then added with the appropriate amount of butyraldehyde and hydrochloric acid.
3. Applications of polyvinyl butyral
3.1 Application in security glass interlayer
Polyvinyl butyral has good light transmission properties, and the refractive index of glass is almost the same. The refractive index of polyvinyl butyral is almost the same as that of glass, and it has strong weathering resistance and can keep the shape stability. At the same time, the also has a very strong flexibility, in the impact test, polyvinyl butyral In impact tests, polyvinyl butyral outperforms many resin materials. Based on these advantages, PVB is used in a large number of security window films.
3.2 Application in ceramic flower paper
Ceramic flower paper is actually based on wood-based paper covered with a layer of polyethylene Butyral film, and then printed with a pattern to have the manufacture of ceramic flowers. The manufacturing method is very easy and the cost is very low. In recent years, with the development of ceramic market, the China’s polyvinyl butyral material in the ceramics industry has increased year by year, and its The amount used is close to 20% of the total production of polyvinyl butyral.
3.3 Application in coatings
Conventional paints such as baking paints, varnishes and primers are made from polyvinyl butyral aldehyde mixed with other resins. The hydroxyl group in the polyvinyl butyral molecule provides a reactive chemical group to the thermosetting resin. The hydroxyl group in the polyvinyl butyral molecule provides a reactive chemical group to the thermosetting resin.
3.4 Application in adhesives
With its superb elasticity, toughness and adhesion, polyvinyl butyral is an excellent hot melt base material and has many applications in the field of adhesives. Tests have found that Most of the adhesives containing polyvinyl butyral are thermosetting, hot-melt or structural adhesives. structural adhesives. They can be mixed with phenolic resins for the adhesion of metal products. This method effectively replaces the use of metal rivets and saves a great deal of This method effectively replaces the use of metal rivets and saves the use of metal consumables.
3.5 Application on aluminum foil paper
The rapid development of various industries since the reform and opening up has also led to the development of China’s packaging industry. The development of the industry, the performance requirements for packaging materials are also increasing. Polyethylene Aluminum foil paper with polyvinyl butyral as coating has been developing rapidly in recent years by virtue of its good isolation and the reduction of packaging cost. The use of polyvinyl butyral as a coating has led to rapid development in recent years.
3.6 Applications in engineering plastics and fibers
Polyvinyl butyral can be used as a base material for FRP or directly processed by injection molding into high strength, impact resistant plastic pipes, rods or parts. It can also be processed directly into high-strength, impact-resistant plastic pipes, rods or parts through the injection molding process.
3.7 Other applications
With the development of material science and technology, researchers and scholars have explored many innovative applications based on the properties of polyvinyl butyral. properties, many innovative applications have been explored. In addition, polyvinyl butyral can also be used in new applications such as artificial sponges, printed circuits and biological carriers in the medical field. Many new fields of application have been identified.
4. Concluding remarks
To sum up, polyvinyl butyral has quite a number of excellent properties, especially outstanding are flexibility and transparency, impact resistance and weathering resistance, and therefore are used in a large number of applications in the aviation, automotive, coating industry and printing industry.